diff.con commit Merge branch 'dl/complete-submodule-absorbgitdirs' (26e3ddc)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "object-store.h"
  17#include "userdiff.h"
  18#include "submodule-config.h"
  19#include "submodule.h"
  20#include "hashmap.h"
  21#include "ll-merge.h"
  22#include "string-list.h"
  23#include "argv-array.h"
  24#include "graph.h"
  25#include "packfile.h"
  26#include "parse-options.h"
  27#include "help.h"
  28
  29#ifdef NO_FAST_WORKING_DIRECTORY
  30#define FAST_WORKING_DIRECTORY 0
  31#else
  32#define FAST_WORKING_DIRECTORY 1
  33#endif
  34
  35static int diff_detect_rename_default;
  36static int diff_indent_heuristic = 1;
  37static int diff_rename_limit_default = 400;
  38static int diff_suppress_blank_empty;
  39static int diff_use_color_default = -1;
  40static int diff_color_moved_default;
  41static int diff_color_moved_ws_default;
  42static int diff_context_default = 3;
  43static int diff_interhunk_context_default;
  44static const char *diff_word_regex_cfg;
  45static const char *external_diff_cmd_cfg;
  46static const char *diff_order_file_cfg;
  47int diff_auto_refresh_index = 1;
  48static int diff_mnemonic_prefix;
  49static int diff_no_prefix;
  50static int diff_stat_graph_width;
  51static int diff_dirstat_permille_default = 30;
  52static struct diff_options default_diff_options;
  53static long diff_algorithm;
  54static unsigned ws_error_highlight_default = WSEH_NEW;
  55
  56static char diff_colors[][COLOR_MAXLEN] = {
  57        GIT_COLOR_RESET,
  58        GIT_COLOR_NORMAL,       /* CONTEXT */
  59        GIT_COLOR_BOLD,         /* METAINFO */
  60        GIT_COLOR_CYAN,         /* FRAGINFO */
  61        GIT_COLOR_RED,          /* OLD */
  62        GIT_COLOR_GREEN,        /* NEW */
  63        GIT_COLOR_YELLOW,       /* COMMIT */
  64        GIT_COLOR_BG_RED,       /* WHITESPACE */
  65        GIT_COLOR_NORMAL,       /* FUNCINFO */
  66        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  67        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  68        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  69        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  70        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  71        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  72        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  73        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  74        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  75        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  76        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  77        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  78        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  79        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  80};
  81
  82static const char *color_diff_slots[] = {
  83        [DIFF_CONTEXT]                = "context",
  84        [DIFF_METAINFO]               = "meta",
  85        [DIFF_FRAGINFO]               = "frag",
  86        [DIFF_FILE_OLD]               = "old",
  87        [DIFF_FILE_NEW]               = "new",
  88        [DIFF_COMMIT]                 = "commit",
  89        [DIFF_WHITESPACE]             = "whitespace",
  90        [DIFF_FUNCINFO]               = "func",
  91        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  92        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  93        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  94        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  95        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  96        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  97        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  98        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  99        [DIFF_CONTEXT_DIM]            = "contextDimmed",
 100        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 101        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 102        [DIFF_CONTEXT_BOLD]           = "contextBold",
 103        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 104        [DIFF_FILE_NEW_BOLD]          = "newBold",
 105};
 106
 107static NORETURN void die_want_option(const char *option_name)
 108{
 109        die(_("option '%s' requires a value"), option_name);
 110}
 111
 112define_list_config_array_extra(color_diff_slots, {"plain"});
 113
 114static int parse_diff_color_slot(const char *var)
 115{
 116        if (!strcasecmp(var, "plain"))
 117                return DIFF_CONTEXT;
 118        return LOOKUP_CONFIG(color_diff_slots, var);
 119}
 120
 121static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 122                                struct strbuf *errmsg)
 123{
 124        char *params_copy = xstrdup(params_string);
 125        struct string_list params = STRING_LIST_INIT_NODUP;
 126        int ret = 0;
 127        int i;
 128
 129        if (*params_copy)
 130                string_list_split_in_place(&params, params_copy, ',', -1);
 131        for (i = 0; i < params.nr; i++) {
 132                const char *p = params.items[i].string;
 133                if (!strcmp(p, "changes")) {
 134                        options->flags.dirstat_by_line = 0;
 135                        options->flags.dirstat_by_file = 0;
 136                } else if (!strcmp(p, "lines")) {
 137                        options->flags.dirstat_by_line = 1;
 138                        options->flags.dirstat_by_file = 0;
 139                } else if (!strcmp(p, "files")) {
 140                        options->flags.dirstat_by_line = 0;
 141                        options->flags.dirstat_by_file = 1;
 142                } else if (!strcmp(p, "noncumulative")) {
 143                        options->flags.dirstat_cumulative = 0;
 144                } else if (!strcmp(p, "cumulative")) {
 145                        options->flags.dirstat_cumulative = 1;
 146                } else if (isdigit(*p)) {
 147                        char *end;
 148                        int permille = strtoul(p, &end, 10) * 10;
 149                        if (*end == '.' && isdigit(*++end)) {
 150                                /* only use first digit */
 151                                permille += *end - '0';
 152                                /* .. and ignore any further digits */
 153                                while (isdigit(*++end))
 154                                        ; /* nothing */
 155                        }
 156                        if (!*end)
 157                                options->dirstat_permille = permille;
 158                        else {
 159                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 160                                            p);
 161                                ret++;
 162                        }
 163                } else {
 164                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 165                        ret++;
 166                }
 167
 168        }
 169        string_list_clear(&params, 0);
 170        free(params_copy);
 171        return ret;
 172}
 173
 174static int parse_submodule_params(struct diff_options *options, const char *value)
 175{
 176        if (!strcmp(value, "log"))
 177                options->submodule_format = DIFF_SUBMODULE_LOG;
 178        else if (!strcmp(value, "short"))
 179                options->submodule_format = DIFF_SUBMODULE_SHORT;
 180        else if (!strcmp(value, "diff"))
 181                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 182        else
 183                return -1;
 184        return 0;
 185}
 186
 187int git_config_rename(const char *var, const char *value)
 188{
 189        if (!value)
 190                return DIFF_DETECT_RENAME;
 191        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 192                return  DIFF_DETECT_COPY;
 193        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 194}
 195
 196long parse_algorithm_value(const char *value)
 197{
 198        if (!value)
 199                return -1;
 200        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 201                return 0;
 202        else if (!strcasecmp(value, "minimal"))
 203                return XDF_NEED_MINIMAL;
 204        else if (!strcasecmp(value, "patience"))
 205                return XDF_PATIENCE_DIFF;
 206        else if (!strcasecmp(value, "histogram"))
 207                return XDF_HISTOGRAM_DIFF;
 208        return -1;
 209}
 210
 211static int parse_one_token(const char **arg, const char *token)
 212{
 213        const char *rest;
 214        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 215                *arg = rest;
 216                return 1;
 217        }
 218        return 0;
 219}
 220
 221static int parse_ws_error_highlight(const char *arg)
 222{
 223        const char *orig_arg = arg;
 224        unsigned val = 0;
 225
 226        while (*arg) {
 227                if (parse_one_token(&arg, "none"))
 228                        val = 0;
 229                else if (parse_one_token(&arg, "default"))
 230                        val = WSEH_NEW;
 231                else if (parse_one_token(&arg, "all"))
 232                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 233                else if (parse_one_token(&arg, "new"))
 234                        val |= WSEH_NEW;
 235                else if (parse_one_token(&arg, "old"))
 236                        val |= WSEH_OLD;
 237                else if (parse_one_token(&arg, "context"))
 238                        val |= WSEH_CONTEXT;
 239                else {
 240                        return -1 - (int)(arg - orig_arg);
 241                }
 242                if (*arg)
 243                        arg++;
 244        }
 245        return val;
 246}
 247
 248/*
 249 * These are to give UI layer defaults.
 250 * The core-level commands such as git-diff-files should
 251 * never be affected by the setting of diff.renames
 252 * the user happens to have in the configuration file.
 253 */
 254void init_diff_ui_defaults(void)
 255{
 256        diff_detect_rename_default = DIFF_DETECT_RENAME;
 257}
 258
 259int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 260{
 261        if (!strcmp(var, "diff.indentheuristic"))
 262                diff_indent_heuristic = git_config_bool(var, value);
 263        return 0;
 264}
 265
 266static int parse_color_moved(const char *arg)
 267{
 268        switch (git_parse_maybe_bool(arg)) {
 269        case 0:
 270                return COLOR_MOVED_NO;
 271        case 1:
 272                return COLOR_MOVED_DEFAULT;
 273        default:
 274                break;
 275        }
 276
 277        if (!strcmp(arg, "no"))
 278                return COLOR_MOVED_NO;
 279        else if (!strcmp(arg, "plain"))
 280                return COLOR_MOVED_PLAIN;
 281        else if (!strcmp(arg, "blocks"))
 282                return COLOR_MOVED_BLOCKS;
 283        else if (!strcmp(arg, "zebra"))
 284                return COLOR_MOVED_ZEBRA;
 285        else if (!strcmp(arg, "default"))
 286                return COLOR_MOVED_DEFAULT;
 287        else if (!strcmp(arg, "dimmed-zebra"))
 288                return COLOR_MOVED_ZEBRA_DIM;
 289        else if (!strcmp(arg, "dimmed_zebra"))
 290                return COLOR_MOVED_ZEBRA_DIM;
 291        else
 292                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 293}
 294
 295static unsigned parse_color_moved_ws(const char *arg)
 296{
 297        int ret = 0;
 298        struct string_list l = STRING_LIST_INIT_DUP;
 299        struct string_list_item *i;
 300
 301        string_list_split(&l, arg, ',', -1);
 302
 303        for_each_string_list_item(i, &l) {
 304                struct strbuf sb = STRBUF_INIT;
 305                strbuf_addstr(&sb, i->string);
 306                strbuf_trim(&sb);
 307
 308                if (!strcmp(sb.buf, "no"))
 309                        ret = 0;
 310                else if (!strcmp(sb.buf, "ignore-space-change"))
 311                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 312                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 313                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 314                else if (!strcmp(sb.buf, "ignore-all-space"))
 315                        ret |= XDF_IGNORE_WHITESPACE;
 316                else if (!strcmp(sb.buf, "allow-indentation-change"))
 317                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 318                else {
 319                        ret |= COLOR_MOVED_WS_ERROR;
 320                        error(_("unknown color-moved-ws mode '%s', possible values are 'ignore-space-change', 'ignore-space-at-eol', 'ignore-all-space', 'allow-indentation-change'"), sb.buf);
 321                }
 322
 323                strbuf_release(&sb);
 324        }
 325
 326        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 327            (ret & XDF_WHITESPACE_FLAGS)) {
 328                error(_("color-moved-ws: allow-indentation-change cannot be combined with other whitespace modes"));
 329                ret |= COLOR_MOVED_WS_ERROR;
 330        }
 331
 332        string_list_clear(&l, 0);
 333
 334        return ret;
 335}
 336
 337int git_diff_ui_config(const char *var, const char *value, void *cb)
 338{
 339        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 340                diff_use_color_default = git_config_colorbool(var, value);
 341                return 0;
 342        }
 343        if (!strcmp(var, "diff.colormoved")) {
 344                int cm = parse_color_moved(value);
 345                if (cm < 0)
 346                        return -1;
 347                diff_color_moved_default = cm;
 348                return 0;
 349        }
 350        if (!strcmp(var, "diff.colormovedws")) {
 351                unsigned cm = parse_color_moved_ws(value);
 352                if (cm & COLOR_MOVED_WS_ERROR)
 353                        return -1;
 354                diff_color_moved_ws_default = cm;
 355                return 0;
 356        }
 357        if (!strcmp(var, "diff.context")) {
 358                diff_context_default = git_config_int(var, value);
 359                if (diff_context_default < 0)
 360                        return -1;
 361                return 0;
 362        }
 363        if (!strcmp(var, "diff.interhunkcontext")) {
 364                diff_interhunk_context_default = git_config_int(var, value);
 365                if (diff_interhunk_context_default < 0)
 366                        return -1;
 367                return 0;
 368        }
 369        if (!strcmp(var, "diff.renames")) {
 370                diff_detect_rename_default = git_config_rename(var, value);
 371                return 0;
 372        }
 373        if (!strcmp(var, "diff.autorefreshindex")) {
 374                diff_auto_refresh_index = git_config_bool(var, value);
 375                return 0;
 376        }
 377        if (!strcmp(var, "diff.mnemonicprefix")) {
 378                diff_mnemonic_prefix = git_config_bool(var, value);
 379                return 0;
 380        }
 381        if (!strcmp(var, "diff.noprefix")) {
 382                diff_no_prefix = git_config_bool(var, value);
 383                return 0;
 384        }
 385        if (!strcmp(var, "diff.statgraphwidth")) {
 386                diff_stat_graph_width = git_config_int(var, value);
 387                return 0;
 388        }
 389        if (!strcmp(var, "diff.external"))
 390                return git_config_string(&external_diff_cmd_cfg, var, value);
 391        if (!strcmp(var, "diff.wordregex"))
 392                return git_config_string(&diff_word_regex_cfg, var, value);
 393        if (!strcmp(var, "diff.orderfile"))
 394                return git_config_pathname(&diff_order_file_cfg, var, value);
 395
 396        if (!strcmp(var, "diff.ignoresubmodules"))
 397                handle_ignore_submodules_arg(&default_diff_options, value);
 398
 399        if (!strcmp(var, "diff.submodule")) {
 400                if (parse_submodule_params(&default_diff_options, value))
 401                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 402                                value);
 403                return 0;
 404        }
 405
 406        if (!strcmp(var, "diff.algorithm")) {
 407                diff_algorithm = parse_algorithm_value(value);
 408                if (diff_algorithm < 0)
 409                        return -1;
 410                return 0;
 411        }
 412
 413        if (!strcmp(var, "diff.wserrorhighlight")) {
 414                int val = parse_ws_error_highlight(value);
 415                if (val < 0)
 416                        return -1;
 417                ws_error_highlight_default = val;
 418                return 0;
 419        }
 420
 421        if (git_color_config(var, value, cb) < 0)
 422                return -1;
 423
 424        return git_diff_basic_config(var, value, cb);
 425}
 426
 427int git_diff_basic_config(const char *var, const char *value, void *cb)
 428{
 429        const char *name;
 430
 431        if (!strcmp(var, "diff.renamelimit")) {
 432                diff_rename_limit_default = git_config_int(var, value);
 433                return 0;
 434        }
 435
 436        if (userdiff_config(var, value) < 0)
 437                return -1;
 438
 439        if (skip_prefix(var, "diff.color.", &name) ||
 440            skip_prefix(var, "color.diff.", &name)) {
 441                int slot = parse_diff_color_slot(name);
 442                if (slot < 0)
 443                        return 0;
 444                if (!value)
 445                        return config_error_nonbool(var);
 446                return color_parse(value, diff_colors[slot]);
 447        }
 448
 449        /* like GNU diff's --suppress-blank-empty option  */
 450        if (!strcmp(var, "diff.suppressblankempty") ||
 451                        /* for backwards compatibility */
 452                        !strcmp(var, "diff.suppress-blank-empty")) {
 453                diff_suppress_blank_empty = git_config_bool(var, value);
 454                return 0;
 455        }
 456
 457        if (!strcmp(var, "diff.dirstat")) {
 458                struct strbuf errmsg = STRBUF_INIT;
 459                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 460                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 461                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 462                                errmsg.buf);
 463                strbuf_release(&errmsg);
 464                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 465                return 0;
 466        }
 467
 468        if (git_diff_heuristic_config(var, value, cb) < 0)
 469                return -1;
 470
 471        return git_default_config(var, value, cb);
 472}
 473
 474static char *quote_two(const char *one, const char *two)
 475{
 476        int need_one = quote_c_style(one, NULL, NULL, 1);
 477        int need_two = quote_c_style(two, NULL, NULL, 1);
 478        struct strbuf res = STRBUF_INIT;
 479
 480        if (need_one + need_two) {
 481                strbuf_addch(&res, '"');
 482                quote_c_style(one, &res, NULL, 1);
 483                quote_c_style(two, &res, NULL, 1);
 484                strbuf_addch(&res, '"');
 485        } else {
 486                strbuf_addstr(&res, one);
 487                strbuf_addstr(&res, two);
 488        }
 489        return strbuf_detach(&res, NULL);
 490}
 491
 492static const char *external_diff(void)
 493{
 494        static const char *external_diff_cmd = NULL;
 495        static int done_preparing = 0;
 496
 497        if (done_preparing)
 498                return external_diff_cmd;
 499        external_diff_cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF"));
 500        if (!external_diff_cmd)
 501                external_diff_cmd = external_diff_cmd_cfg;
 502        done_preparing = 1;
 503        return external_diff_cmd;
 504}
 505
 506/*
 507 * Keep track of files used for diffing. Sometimes such an entry
 508 * refers to a temporary file, sometimes to an existing file, and
 509 * sometimes to "/dev/null".
 510 */
 511static struct diff_tempfile {
 512        /*
 513         * filename external diff should read from, or NULL if this
 514         * entry is currently not in use:
 515         */
 516        const char *name;
 517
 518        char hex[GIT_MAX_HEXSZ + 1];
 519        char mode[10];
 520
 521        /*
 522         * If this diff_tempfile instance refers to a temporary file,
 523         * this tempfile object is used to manage its lifetime.
 524         */
 525        struct tempfile *tempfile;
 526} diff_temp[2];
 527
 528struct emit_callback {
 529        int color_diff;
 530        unsigned ws_rule;
 531        int blank_at_eof_in_preimage;
 532        int blank_at_eof_in_postimage;
 533        int lno_in_preimage;
 534        int lno_in_postimage;
 535        const char **label_path;
 536        struct diff_words_data *diff_words;
 537        struct diff_options *opt;
 538        struct strbuf *header;
 539};
 540
 541static int count_lines(const char *data, int size)
 542{
 543        int count, ch, completely_empty = 1, nl_just_seen = 0;
 544        count = 0;
 545        while (0 < size--) {
 546                ch = *data++;
 547                if (ch == '\n') {
 548                        count++;
 549                        nl_just_seen = 1;
 550                        completely_empty = 0;
 551                }
 552                else {
 553                        nl_just_seen = 0;
 554                        completely_empty = 0;
 555                }
 556        }
 557        if (completely_empty)
 558                return 0;
 559        if (!nl_just_seen)
 560                count++; /* no trailing newline */
 561        return count;
 562}
 563
 564static int fill_mmfile(struct repository *r, mmfile_t *mf,
 565                       struct diff_filespec *one)
 566{
 567        if (!DIFF_FILE_VALID(one)) {
 568                mf->ptr = (char *)""; /* does not matter */
 569                mf->size = 0;
 570                return 0;
 571        }
 572        else if (diff_populate_filespec(r, one, 0))
 573                return -1;
 574
 575        mf->ptr = one->data;
 576        mf->size = one->size;
 577        return 0;
 578}
 579
 580/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 581static unsigned long diff_filespec_size(struct repository *r,
 582                                        struct diff_filespec *one)
 583{
 584        if (!DIFF_FILE_VALID(one))
 585                return 0;
 586        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 587        return one->size;
 588}
 589
 590static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 591{
 592        char *ptr = mf->ptr;
 593        long size = mf->size;
 594        int cnt = 0;
 595
 596        if (!size)
 597                return cnt;
 598        ptr += size - 1; /* pointing at the very end */
 599        if (*ptr != '\n')
 600                ; /* incomplete line */
 601        else
 602                ptr--; /* skip the last LF */
 603        while (mf->ptr < ptr) {
 604                char *prev_eol;
 605                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 606                        if (*prev_eol == '\n')
 607                                break;
 608                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 609                        break;
 610                cnt++;
 611                ptr = prev_eol - 1;
 612        }
 613        return cnt;
 614}
 615
 616static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 617                               struct emit_callback *ecbdata)
 618{
 619        int l1, l2, at;
 620        unsigned ws_rule = ecbdata->ws_rule;
 621        l1 = count_trailing_blank(mf1, ws_rule);
 622        l2 = count_trailing_blank(mf2, ws_rule);
 623        if (l2 <= l1) {
 624                ecbdata->blank_at_eof_in_preimage = 0;
 625                ecbdata->blank_at_eof_in_postimage = 0;
 626                return;
 627        }
 628        at = count_lines(mf1->ptr, mf1->size);
 629        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 630
 631        at = count_lines(mf2->ptr, mf2->size);
 632        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 633}
 634
 635static void emit_line_0(struct diff_options *o,
 636                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 637                        int first, const char *line, int len)
 638{
 639        int has_trailing_newline, has_trailing_carriage_return;
 640        int needs_reset = 0; /* at the end of the line */
 641        FILE *file = o->file;
 642
 643        fputs(diff_line_prefix(o), file);
 644
 645        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 646        if (has_trailing_newline)
 647                len--;
 648
 649        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 650        if (has_trailing_carriage_return)
 651                len--;
 652
 653        if (!len && !first)
 654                goto end_of_line;
 655
 656        if (reverse && want_color(o->use_color)) {
 657                fputs(GIT_COLOR_REVERSE, file);
 658                needs_reset = 1;
 659        }
 660
 661        if (set_sign) {
 662                fputs(set_sign, file);
 663                needs_reset = 1;
 664        }
 665
 666        if (first)
 667                fputc(first, file);
 668
 669        if (!len)
 670                goto end_of_line;
 671
 672        if (set) {
 673                if (set_sign && set != set_sign)
 674                        fputs(reset, file);
 675                fputs(set, file);
 676                needs_reset = 1;
 677        }
 678        fwrite(line, len, 1, file);
 679        needs_reset = 1; /* 'line' may contain color codes. */
 680
 681end_of_line:
 682        if (needs_reset)
 683                fputs(reset, file);
 684        if (has_trailing_carriage_return)
 685                fputc('\r', file);
 686        if (has_trailing_newline)
 687                fputc('\n', file);
 688}
 689
 690static void emit_line(struct diff_options *o, const char *set, const char *reset,
 691                      const char *line, int len)
 692{
 693        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 694}
 695
 696enum diff_symbol {
 697        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 698        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 699        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 700        DIFF_SYMBOL_BINARY_DIFF_BODY,
 701        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 702        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 703        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 704        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 705        DIFF_SYMBOL_STATS_LINE,
 706        DIFF_SYMBOL_WORD_DIFF,
 707        DIFF_SYMBOL_STAT_SEP,
 708        DIFF_SYMBOL_SUMMARY,
 709        DIFF_SYMBOL_SUBMODULE_ADD,
 710        DIFF_SYMBOL_SUBMODULE_DEL,
 711        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 712        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 713        DIFF_SYMBOL_SUBMODULE_HEADER,
 714        DIFF_SYMBOL_SUBMODULE_ERROR,
 715        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 716        DIFF_SYMBOL_REWRITE_DIFF,
 717        DIFF_SYMBOL_BINARY_FILES,
 718        DIFF_SYMBOL_HEADER,
 719        DIFF_SYMBOL_FILEPAIR_PLUS,
 720        DIFF_SYMBOL_FILEPAIR_MINUS,
 721        DIFF_SYMBOL_WORDS_PORCELAIN,
 722        DIFF_SYMBOL_WORDS,
 723        DIFF_SYMBOL_CONTEXT,
 724        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 725        DIFF_SYMBOL_PLUS,
 726        DIFF_SYMBOL_MINUS,
 727        DIFF_SYMBOL_NO_LF_EOF,
 728        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 729        DIFF_SYMBOL_CONTEXT_MARKER,
 730        DIFF_SYMBOL_SEPARATOR
 731};
 732/*
 733 * Flags for content lines:
 734 * 0..12 are whitespace rules
 735 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 736 * 16 is marking if the line is blank at EOF
 737 */
 738#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 739#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 740#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 741#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 742#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 743
 744/*
 745 * This struct is used when we need to buffer the output of the diff output.
 746 *
 747 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 748 * into the pre/post image file. This pointer could be a union with the
 749 * line pointer. By storing an offset into the file instead of the literal line,
 750 * we can decrease the memory footprint for the buffered output. At first we
 751 * may want to only have indirection for the content lines, but we could also
 752 * enhance the state for emitting prefabricated lines, e.g. the similarity
 753 * score line or hunk/file headers would only need to store a number or path
 754 * and then the output can be constructed later on depending on state.
 755 */
 756struct emitted_diff_symbol {
 757        const char *line;
 758        int len;
 759        int flags;
 760        int indent_off;   /* Offset to first non-whitespace character */
 761        int indent_width; /* The visual width of the indentation */
 762        enum diff_symbol s;
 763};
 764#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 765
 766struct emitted_diff_symbols {
 767        struct emitted_diff_symbol *buf;
 768        int nr, alloc;
 769};
 770#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 771
 772static void append_emitted_diff_symbol(struct diff_options *o,
 773                                       struct emitted_diff_symbol *e)
 774{
 775        struct emitted_diff_symbol *f;
 776
 777        ALLOC_GROW(o->emitted_symbols->buf,
 778                   o->emitted_symbols->nr + 1,
 779                   o->emitted_symbols->alloc);
 780        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 781
 782        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 783        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 784}
 785
 786struct moved_entry {
 787        struct hashmap_entry ent;
 788        const struct emitted_diff_symbol *es;
 789        struct moved_entry *next_line;
 790};
 791
 792struct moved_block {
 793        struct moved_entry *match;
 794        int wsd; /* The whitespace delta of this block */
 795};
 796
 797static void moved_block_clear(struct moved_block *b)
 798{
 799        memset(b, 0, sizeof(*b));
 800}
 801
 802#define INDENT_BLANKLINE INT_MIN
 803
 804static void fill_es_indent_data(struct emitted_diff_symbol *es)
 805{
 806        unsigned int off = 0, i;
 807        int width = 0, tab_width = es->flags & WS_TAB_WIDTH_MASK;
 808        const char *s = es->line;
 809        const int len = es->len;
 810
 811        /* skip any \v \f \r at start of indentation */
 812        while (s[off] == '\f' || s[off] == '\v' ||
 813               (s[off] == '\r' && off < len - 1))
 814                off++;
 815
 816        /* calculate the visual width of indentation */
 817        while(1) {
 818                if (s[off] == ' ') {
 819                        width++;
 820                        off++;
 821                } else if (s[off] == '\t') {
 822                        width += tab_width - (width % tab_width);
 823                        while (s[++off] == '\t')
 824                                width += tab_width;
 825                } else {
 826                        break;
 827                }
 828        }
 829
 830        /* check if this line is blank */
 831        for (i = off; i < len; i++)
 832                if (!isspace(s[i]))
 833                    break;
 834
 835        if (i == len) {
 836                es->indent_width = INDENT_BLANKLINE;
 837                es->indent_off = len;
 838        } else {
 839                es->indent_off = off;
 840                es->indent_width = width;
 841        }
 842}
 843
 844static int compute_ws_delta(const struct emitted_diff_symbol *a,
 845                            const struct emitted_diff_symbol *b,
 846                            int *out)
 847{
 848        int a_len = a->len,
 849            b_len = b->len,
 850            a_off = a->indent_off,
 851            a_width = a->indent_width,
 852            b_off = b->indent_off,
 853            b_width = b->indent_width;
 854        int delta;
 855
 856        if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
 857                *out = INDENT_BLANKLINE;
 858                return 1;
 859        }
 860
 861        if (a->s == DIFF_SYMBOL_PLUS)
 862                delta = a_width - b_width;
 863        else
 864                delta = b_width - a_width;
 865
 866        if (a_len - a_off != b_len - b_off ||
 867            memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
 868                return 0;
 869
 870        *out = delta;
 871
 872        return 1;
 873}
 874
 875static int cmp_in_block_with_wsd(const struct diff_options *o,
 876                                 const struct moved_entry *cur,
 877                                 const struct moved_entry *match,
 878                                 struct moved_block *pmb,
 879                                 int n)
 880{
 881        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 882        int al = cur->es->len, bl = match->es->len, cl = l->len;
 883        const char *a = cur->es->line,
 884                   *b = match->es->line,
 885                   *c = l->line;
 886        int a_off = cur->es->indent_off,
 887            a_width = cur->es->indent_width,
 888            c_off = l->indent_off,
 889            c_width = l->indent_width;
 890        int delta;
 891
 892        /*
 893         * We need to check if 'cur' is equal to 'match'.  As those
 894         * are from the same (+/-) side, we do not need to adjust for
 895         * indent changes. However these were found using fuzzy
 896         * matching so we do have to check if they are equal. Here we
 897         * just check the lengths. We delay calling memcmp() to check
 898         * the contents until later as if the length comparison for a
 899         * and c fails we can avoid the call all together.
 900         */
 901        if (al != bl)
 902                return 1;
 903
 904        /* If 'l' and 'cur' are both blank then they match. */
 905        if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
 906                return 0;
 907
 908        /*
 909         * The indent changes of the block are known and stored in pmb->wsd;
 910         * however we need to check if the indent changes of the current line
 911         * match those of the current block and that the text of 'l' and 'cur'
 912         * after the indentation match.
 913         */
 914        if (cur->es->s == DIFF_SYMBOL_PLUS)
 915                delta = a_width - c_width;
 916        else
 917                delta = c_width - a_width;
 918
 919        /*
 920         * If the previous lines of this block were all blank then set its
 921         * whitespace delta.
 922         */
 923        if (pmb->wsd == INDENT_BLANKLINE)
 924                pmb->wsd = delta;
 925
 926        return !(delta == pmb->wsd && al - a_off == cl - c_off &&
 927                 !memcmp(a, b, al) && !
 928                 memcmp(a + a_off, c + c_off, al - a_off));
 929}
 930
 931static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 932                           const void *entry,
 933                           const void *entry_or_key,
 934                           const void *keydata)
 935{
 936        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 937        const struct moved_entry *a = entry;
 938        const struct moved_entry *b = entry_or_key;
 939        unsigned flags = diffopt->color_moved_ws_handling
 940                         & XDF_WHITESPACE_FLAGS;
 941
 942        if (diffopt->color_moved_ws_handling &
 943            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 944                /*
 945                 * As there is not specific white space config given,
 946                 * we'd need to check for a new block, so ignore all
 947                 * white space. The setup of the white space
 948                 * configuration for the next block is done else where
 949                 */
 950                flags |= XDF_IGNORE_WHITESPACE;
 951
 952        return !xdiff_compare_lines(a->es->line, a->es->len,
 953                                    b->es->line, b->es->len,
 954                                    flags);
 955}
 956
 957static struct moved_entry *prepare_entry(struct diff_options *o,
 958                                         int line_no)
 959{
 960        struct moved_entry *ret = xmalloc(sizeof(*ret));
 961        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 962        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 963
 964        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 965        ret->es = l;
 966        ret->next_line = NULL;
 967
 968        return ret;
 969}
 970
 971static void add_lines_to_move_detection(struct diff_options *o,
 972                                        struct hashmap *add_lines,
 973                                        struct hashmap *del_lines)
 974{
 975        struct moved_entry *prev_line = NULL;
 976
 977        int n;
 978        for (n = 0; n < o->emitted_symbols->nr; n++) {
 979                struct hashmap *hm;
 980                struct moved_entry *key;
 981
 982                switch (o->emitted_symbols->buf[n].s) {
 983                case DIFF_SYMBOL_PLUS:
 984                        hm = add_lines;
 985                        break;
 986                case DIFF_SYMBOL_MINUS:
 987                        hm = del_lines;
 988                        break;
 989                default:
 990                        prev_line = NULL;
 991                        continue;
 992                }
 993
 994                if (o->color_moved_ws_handling &
 995                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 996                        fill_es_indent_data(&o->emitted_symbols->buf[n]);
 997                key = prepare_entry(o, n);
 998                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 999                        prev_line->next_line = key;
1000
1001                hashmap_add(hm, key);
1002                prev_line = key;
1003        }
1004}
1005
1006static void pmb_advance_or_null(struct diff_options *o,
1007                                struct moved_entry *match,
1008                                struct hashmap *hm,
1009                                struct moved_block *pmb,
1010                                int pmb_nr)
1011{
1012        int i;
1013        for (i = 0; i < pmb_nr; i++) {
1014                struct moved_entry *prev = pmb[i].match;
1015                struct moved_entry *cur = (prev && prev->next_line) ?
1016                                prev->next_line : NULL;
1017                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
1018                        pmb[i].match = cur;
1019                } else {
1020                        pmb[i].match = NULL;
1021                }
1022        }
1023}
1024
1025static void pmb_advance_or_null_multi_match(struct diff_options *o,
1026                                            struct moved_entry *match,
1027                                            struct hashmap *hm,
1028                                            struct moved_block *pmb,
1029                                            int pmb_nr, int n)
1030{
1031        int i;
1032        char *got_match = xcalloc(1, pmb_nr);
1033
1034        for (; match; match = hashmap_get_next(hm, match)) {
1035                for (i = 0; i < pmb_nr; i++) {
1036                        struct moved_entry *prev = pmb[i].match;
1037                        struct moved_entry *cur = (prev && prev->next_line) ?
1038                                        prev->next_line : NULL;
1039                        if (!cur)
1040                                continue;
1041                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
1042                                got_match[i] |= 1;
1043                }
1044        }
1045
1046        for (i = 0; i < pmb_nr; i++) {
1047                if (got_match[i]) {
1048                        /* Advance to the next line */
1049                        pmb[i].match = pmb[i].match->next_line;
1050                } else {
1051                        moved_block_clear(&pmb[i]);
1052                }
1053        }
1054
1055        free(got_match);
1056}
1057
1058static int shrink_potential_moved_blocks(struct moved_block *pmb,
1059                                         int pmb_nr)
1060{
1061        int lp, rp;
1062
1063        /* Shrink the set of potential block to the remaining running */
1064        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1065                while (lp < pmb_nr && pmb[lp].match)
1066                        lp++;
1067                /* lp points at the first NULL now */
1068
1069                while (rp > -1 && !pmb[rp].match)
1070                        rp--;
1071                /* rp points at the last non-NULL */
1072
1073                if (lp < pmb_nr && rp > -1 && lp < rp) {
1074                        pmb[lp] = pmb[rp];
1075                        memset(&pmb[rp], 0, sizeof(pmb[rp]));
1076                        rp--;
1077                        lp++;
1078                }
1079        }
1080
1081        /* Remember the number of running sets */
1082        return rp + 1;
1083}
1084
1085/*
1086 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1087 *
1088 * Otherwise, if the last block has fewer alphanumeric characters than
1089 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1090 * that block.
1091 *
1092 * The last block consists of the (n - block_length)'th line up to but not
1093 * including the nth line.
1094 *
1095 * Returns 0 if the last block is empty or is unset by this function, non zero
1096 * otherwise.
1097 *
1098 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1099 * Think of a way to unify them.
1100 */
1101static int adjust_last_block(struct diff_options *o, int n, int block_length)
1102{
1103        int i, alnum_count = 0;
1104        if (o->color_moved == COLOR_MOVED_PLAIN)
1105                return block_length;
1106        for (i = 1; i < block_length + 1; i++) {
1107                const char *c = o->emitted_symbols->buf[n - i].line;
1108                for (; *c; c++) {
1109                        if (!isalnum(*c))
1110                                continue;
1111                        alnum_count++;
1112                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1113                                return 1;
1114                }
1115        }
1116        for (i = 1; i < block_length + 1; i++)
1117                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1118        return 0;
1119}
1120
1121/* Find blocks of moved code, delegate actual coloring decision to helper */
1122static void mark_color_as_moved(struct diff_options *o,
1123                                struct hashmap *add_lines,
1124                                struct hashmap *del_lines)
1125{
1126        struct moved_block *pmb = NULL; /* potentially moved blocks */
1127        int pmb_nr = 0, pmb_alloc = 0;
1128        int n, flipped_block = 0, block_length = 0;
1129
1130
1131        for (n = 0; n < o->emitted_symbols->nr; n++) {
1132                struct hashmap *hm = NULL;
1133                struct moved_entry *key;
1134                struct moved_entry *match = NULL;
1135                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1136                enum diff_symbol last_symbol = 0;
1137
1138                switch (l->s) {
1139                case DIFF_SYMBOL_PLUS:
1140                        hm = del_lines;
1141                        key = prepare_entry(o, n);
1142                        match = hashmap_get(hm, key, NULL);
1143                        free(key);
1144                        break;
1145                case DIFF_SYMBOL_MINUS:
1146                        hm = add_lines;
1147                        key = prepare_entry(o, n);
1148                        match = hashmap_get(hm, key, NULL);
1149                        free(key);
1150                        break;
1151                default:
1152                        flipped_block = 0;
1153                }
1154
1155                if (!match) {
1156                        int i;
1157
1158                        adjust_last_block(o, n, block_length);
1159                        for(i = 0; i < pmb_nr; i++)
1160                                moved_block_clear(&pmb[i]);
1161                        pmb_nr = 0;
1162                        block_length = 0;
1163                        flipped_block = 0;
1164                        last_symbol = l->s;
1165                        continue;
1166                }
1167
1168                if (o->color_moved == COLOR_MOVED_PLAIN) {
1169                        last_symbol = l->s;
1170                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1171                        continue;
1172                }
1173
1174                if (o->color_moved_ws_handling &
1175                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1176                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1177                else
1178                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1179
1180                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1181
1182                if (pmb_nr == 0) {
1183                        /*
1184                         * The current line is the start of a new block.
1185                         * Setup the set of potential blocks.
1186                         */
1187                        for (; match; match = hashmap_get_next(hm, match)) {
1188                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1189                                if (o->color_moved_ws_handling &
1190                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1191                                        if (compute_ws_delta(l, match->es,
1192                                                             &pmb[pmb_nr].wsd))
1193                                                pmb[pmb_nr++].match = match;
1194                                } else {
1195                                        pmb[pmb_nr].wsd = 0;
1196                                        pmb[pmb_nr++].match = match;
1197                                }
1198                        }
1199
1200                        if (adjust_last_block(o, n, block_length) &&
1201                            pmb_nr && last_symbol != l->s)
1202                                flipped_block = (flipped_block + 1) % 2;
1203                        else
1204                                flipped_block = 0;
1205
1206                        block_length = 0;
1207                }
1208
1209                if (pmb_nr) {
1210                        block_length++;
1211                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1212                        if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1213                                l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1214                }
1215                last_symbol = l->s;
1216        }
1217        adjust_last_block(o, n, block_length);
1218
1219        for(n = 0; n < pmb_nr; n++)
1220                moved_block_clear(&pmb[n]);
1221        free(pmb);
1222}
1223
1224#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1225  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1226static void dim_moved_lines(struct diff_options *o)
1227{
1228        int n;
1229        for (n = 0; n < o->emitted_symbols->nr; n++) {
1230                struct emitted_diff_symbol *prev = (n != 0) ?
1231                                &o->emitted_symbols->buf[n - 1] : NULL;
1232                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1233                struct emitted_diff_symbol *next =
1234                                (n < o->emitted_symbols->nr - 1) ?
1235                                &o->emitted_symbols->buf[n + 1] : NULL;
1236
1237                /* Not a plus or minus line? */
1238                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1239                        continue;
1240
1241                /* Not a moved line? */
1242                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1243                        continue;
1244
1245                /*
1246                 * If prev or next are not a plus or minus line,
1247                 * pretend they don't exist
1248                 */
1249                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1250                            prev->s != DIFF_SYMBOL_MINUS)
1251                        prev = NULL;
1252                if (next && next->s != DIFF_SYMBOL_PLUS &&
1253                            next->s != DIFF_SYMBOL_MINUS)
1254                        next = NULL;
1255
1256                /* Inside a block? */
1257                if ((prev &&
1258                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1259                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1260                    (next &&
1261                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1262                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1263                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1264                        continue;
1265                }
1266
1267                /* Check if we are at an interesting bound: */
1268                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1269                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1270                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1271                        continue;
1272                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1273                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1274                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1275                        continue;
1276
1277                /*
1278                 * The boundary to prev and next are not interesting,
1279                 * so this line is not interesting as a whole
1280                 */
1281                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1282        }
1283}
1284
1285static void emit_line_ws_markup(struct diff_options *o,
1286                                const char *set_sign, const char *set,
1287                                const char *reset,
1288                                int sign_index, const char *line, int len,
1289                                unsigned ws_rule, int blank_at_eof)
1290{
1291        const char *ws = NULL;
1292        int sign = o->output_indicators[sign_index];
1293
1294        if (o->ws_error_highlight & ws_rule) {
1295                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1296                if (!*ws)
1297                        ws = NULL;
1298        }
1299
1300        if (!ws && !set_sign)
1301                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1302        else if (!ws) {
1303                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1304        } else if (blank_at_eof)
1305                /* Blank line at EOF - paint '+' as well */
1306                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1307        else {
1308                /* Emit just the prefix, then the rest. */
1309                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1310                            sign, "", 0);
1311                ws_check_emit(line, len, ws_rule,
1312                              o->file, set, reset, ws);
1313        }
1314}
1315
1316static void emit_diff_symbol_from_struct(struct diff_options *o,
1317                                         struct emitted_diff_symbol *eds)
1318{
1319        static const char *nneof = " No newline at end of file\n";
1320        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1321        struct strbuf sb = STRBUF_INIT;
1322
1323        enum diff_symbol s = eds->s;
1324        const char *line = eds->line;
1325        int len = eds->len;
1326        unsigned flags = eds->flags;
1327
1328        switch (s) {
1329        case DIFF_SYMBOL_NO_LF_EOF:
1330                context = diff_get_color_opt(o, DIFF_CONTEXT);
1331                reset = diff_get_color_opt(o, DIFF_RESET);
1332                putc('\n', o->file);
1333                emit_line_0(o, context, NULL, 0, reset, '\\',
1334                            nneof, strlen(nneof));
1335                break;
1336        case DIFF_SYMBOL_SUBMODULE_HEADER:
1337        case DIFF_SYMBOL_SUBMODULE_ERROR:
1338        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1339        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1340        case DIFF_SYMBOL_SUMMARY:
1341        case DIFF_SYMBOL_STATS_LINE:
1342        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1343        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1344                emit_line(o, "", "", line, len);
1345                break;
1346        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1347        case DIFF_SYMBOL_CONTEXT_MARKER:
1348                context = diff_get_color_opt(o, DIFF_CONTEXT);
1349                reset = diff_get_color_opt(o, DIFF_RESET);
1350                emit_line(o, context, reset, line, len);
1351                break;
1352        case DIFF_SYMBOL_SEPARATOR:
1353                fprintf(o->file, "%s%c",
1354                        diff_line_prefix(o),
1355                        o->line_termination);
1356                break;
1357        case DIFF_SYMBOL_CONTEXT:
1358                set = diff_get_color_opt(o, DIFF_CONTEXT);
1359                reset = diff_get_color_opt(o, DIFF_RESET);
1360                set_sign = NULL;
1361                if (o->flags.dual_color_diffed_diffs) {
1362                        char c = !len ? 0 : line[0];
1363
1364                        if (c == '+')
1365                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1366                        else if (c == '@')
1367                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1368                        else if (c == '-')
1369                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1370                }
1371                emit_line_ws_markup(o, set_sign, set, reset,
1372                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1373                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1374                break;
1375        case DIFF_SYMBOL_PLUS:
1376                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1377                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1378                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1379                case DIFF_SYMBOL_MOVED_LINE |
1380                     DIFF_SYMBOL_MOVED_LINE_ALT |
1381                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1382                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1383                        break;
1384                case DIFF_SYMBOL_MOVED_LINE |
1385                     DIFF_SYMBOL_MOVED_LINE_ALT:
1386                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1387                        break;
1388                case DIFF_SYMBOL_MOVED_LINE |
1389                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1390                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1391                        break;
1392                case DIFF_SYMBOL_MOVED_LINE:
1393                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1394                        break;
1395                default:
1396                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1397                }
1398                reset = diff_get_color_opt(o, DIFF_RESET);
1399                if (!o->flags.dual_color_diffed_diffs)
1400                        set_sign = NULL;
1401                else {
1402                        char c = !len ? 0 : line[0];
1403
1404                        set_sign = set;
1405                        if (c == '-')
1406                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1407                        else if (c == '@')
1408                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1409                        else if (c == '+')
1410                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1411                        else
1412                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1413                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1414                }
1415                emit_line_ws_markup(o, set_sign, set, reset,
1416                                    OUTPUT_INDICATOR_NEW, line, len,
1417                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1418                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1419                break;
1420        case DIFF_SYMBOL_MINUS:
1421                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1422                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1423                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1424                case DIFF_SYMBOL_MOVED_LINE |
1425                     DIFF_SYMBOL_MOVED_LINE_ALT |
1426                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1427                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1428                        break;
1429                case DIFF_SYMBOL_MOVED_LINE |
1430                     DIFF_SYMBOL_MOVED_LINE_ALT:
1431                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1432                        break;
1433                case DIFF_SYMBOL_MOVED_LINE |
1434                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1435                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1436                        break;
1437                case DIFF_SYMBOL_MOVED_LINE:
1438                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1439                        break;
1440                default:
1441                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1442                }
1443                reset = diff_get_color_opt(o, DIFF_RESET);
1444                if (!o->flags.dual_color_diffed_diffs)
1445                        set_sign = NULL;
1446                else {
1447                        char c = !len ? 0 : line[0];
1448
1449                        set_sign = set;
1450                        if (c == '+')
1451                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1452                        else if (c == '@')
1453                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1454                        else if (c == '-')
1455                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1456                        else
1457                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1458                }
1459                emit_line_ws_markup(o, set_sign, set, reset,
1460                                    OUTPUT_INDICATOR_OLD, line, len,
1461                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1462                break;
1463        case DIFF_SYMBOL_WORDS_PORCELAIN:
1464                context = diff_get_color_opt(o, DIFF_CONTEXT);
1465                reset = diff_get_color_opt(o, DIFF_RESET);
1466                emit_line(o, context, reset, line, len);
1467                fputs("~\n", o->file);
1468                break;
1469        case DIFF_SYMBOL_WORDS:
1470                context = diff_get_color_opt(o, DIFF_CONTEXT);
1471                reset = diff_get_color_opt(o, DIFF_RESET);
1472                /*
1473                 * Skip the prefix character, if any.  With
1474                 * diff_suppress_blank_empty, there may be
1475                 * none.
1476                 */
1477                if (line[0] != '\n') {
1478                        line++;
1479                        len--;
1480                }
1481                emit_line(o, context, reset, line, len);
1482                break;
1483        case DIFF_SYMBOL_FILEPAIR_PLUS:
1484                meta = diff_get_color_opt(o, DIFF_METAINFO);
1485                reset = diff_get_color_opt(o, DIFF_RESET);
1486                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1487                        line, reset,
1488                        strchr(line, ' ') ? "\t" : "");
1489                break;
1490        case DIFF_SYMBOL_FILEPAIR_MINUS:
1491                meta = diff_get_color_opt(o, DIFF_METAINFO);
1492                reset = diff_get_color_opt(o, DIFF_RESET);
1493                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1494                        line, reset,
1495                        strchr(line, ' ') ? "\t" : "");
1496                break;
1497        case DIFF_SYMBOL_BINARY_FILES:
1498        case DIFF_SYMBOL_HEADER:
1499                fprintf(o->file, "%s", line);
1500                break;
1501        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1502                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1503                break;
1504        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1505                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1506                break;
1507        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1508                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1509                break;
1510        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1511                fputs(diff_line_prefix(o), o->file);
1512                fputc('\n', o->file);
1513                break;
1514        case DIFF_SYMBOL_REWRITE_DIFF:
1515                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1516                reset = diff_get_color_opt(o, DIFF_RESET);
1517                emit_line(o, fraginfo, reset, line, len);
1518                break;
1519        case DIFF_SYMBOL_SUBMODULE_ADD:
1520                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1521                reset = diff_get_color_opt(o, DIFF_RESET);
1522                emit_line(o, set, reset, line, len);
1523                break;
1524        case DIFF_SYMBOL_SUBMODULE_DEL:
1525                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1526                reset = diff_get_color_opt(o, DIFF_RESET);
1527                emit_line(o, set, reset, line, len);
1528                break;
1529        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1530                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1531                        diff_line_prefix(o), line);
1532                break;
1533        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1534                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1535                        diff_line_prefix(o), line);
1536                break;
1537        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1538                emit_line(o, "", "", " 0 files changed\n",
1539                          strlen(" 0 files changed\n"));
1540                break;
1541        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1542                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1543                break;
1544        case DIFF_SYMBOL_WORD_DIFF:
1545                fprintf(o->file, "%.*s", len, line);
1546                break;
1547        case DIFF_SYMBOL_STAT_SEP:
1548                fputs(o->stat_sep, o->file);
1549                break;
1550        default:
1551                BUG("unknown diff symbol");
1552        }
1553        strbuf_release(&sb);
1554}
1555
1556static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1557                             const char *line, int len, unsigned flags)
1558{
1559        struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
1560
1561        if (o->emitted_symbols)
1562                append_emitted_diff_symbol(o, &e);
1563        else
1564                emit_diff_symbol_from_struct(o, &e);
1565}
1566
1567void diff_emit_submodule_del(struct diff_options *o, const char *line)
1568{
1569        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1570}
1571
1572void diff_emit_submodule_add(struct diff_options *o, const char *line)
1573{
1574        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1575}
1576
1577void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1578{
1579        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1580                         path, strlen(path), 0);
1581}
1582
1583void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1584{
1585        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1586                         path, strlen(path), 0);
1587}
1588
1589void diff_emit_submodule_header(struct diff_options *o, const char *header)
1590{
1591        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1592                         header, strlen(header), 0);
1593}
1594
1595void diff_emit_submodule_error(struct diff_options *o, const char *err)
1596{
1597        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1598}
1599
1600void diff_emit_submodule_pipethrough(struct diff_options *o,
1601                                     const char *line, int len)
1602{
1603        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1604}
1605
1606static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1607{
1608        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1609              ecbdata->blank_at_eof_in_preimage &&
1610              ecbdata->blank_at_eof_in_postimage &&
1611              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1612              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1613                return 0;
1614        return ws_blank_line(line, len, ecbdata->ws_rule);
1615}
1616
1617static void emit_add_line(const char *reset,
1618                          struct emit_callback *ecbdata,
1619                          const char *line, int len)
1620{
1621        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1622        if (new_blank_line_at_eof(ecbdata, line, len))
1623                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1624
1625        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1626}
1627
1628static void emit_del_line(const char *reset,
1629                          struct emit_callback *ecbdata,
1630                          const char *line, int len)
1631{
1632        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1633        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1634}
1635
1636static void emit_context_line(const char *reset,
1637                              struct emit_callback *ecbdata,
1638                              const char *line, int len)
1639{
1640        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1641        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1642}
1643
1644static void emit_hunk_header(struct emit_callback *ecbdata,
1645                             const char *line, int len)
1646{
1647        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1648        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1649        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1650        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1651        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1652        static const char atat[2] = { '@', '@' };
1653        const char *cp, *ep;
1654        struct strbuf msgbuf = STRBUF_INIT;
1655        int org_len = len;
1656        int i = 1;
1657
1658        /*
1659         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1660         * it always is at least 10 bytes long.
1661         */
1662        if (len < 10 ||
1663            memcmp(line, atat, 2) ||
1664            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1665                emit_diff_symbol(ecbdata->opt,
1666                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1667                return;
1668        }
1669        ep += 2; /* skip over @@ */
1670
1671        /* The hunk header in fraginfo color */
1672        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1673                strbuf_addstr(&msgbuf, reverse);
1674        strbuf_addstr(&msgbuf, frag);
1675        strbuf_add(&msgbuf, line, ep - line);
1676        strbuf_addstr(&msgbuf, reset);
1677
1678        /*
1679         * trailing "\r\n"
1680         */
1681        for ( ; i < 3; i++)
1682                if (line[len - i] == '\r' || line[len - i] == '\n')
1683                        len--;
1684
1685        /* blank before the func header */
1686        for (cp = ep; ep - line < len; ep++)
1687                if (*ep != ' ' && *ep != '\t')
1688                        break;
1689        if (ep != cp) {
1690                strbuf_addstr(&msgbuf, context);
1691                strbuf_add(&msgbuf, cp, ep - cp);
1692                strbuf_addstr(&msgbuf, reset);
1693        }
1694
1695        if (ep < line + len) {
1696                strbuf_addstr(&msgbuf, func);
1697                strbuf_add(&msgbuf, ep, line + len - ep);
1698                strbuf_addstr(&msgbuf, reset);
1699        }
1700
1701        strbuf_add(&msgbuf, line + len, org_len - len);
1702        strbuf_complete_line(&msgbuf);
1703        emit_diff_symbol(ecbdata->opt,
1704                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1705        strbuf_release(&msgbuf);
1706}
1707
1708static struct diff_tempfile *claim_diff_tempfile(void)
1709{
1710        int i;
1711        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1712                if (!diff_temp[i].name)
1713                        return diff_temp + i;
1714        BUG("diff is failing to clean up its tempfiles");
1715}
1716
1717static void remove_tempfile(void)
1718{
1719        int i;
1720        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1721                if (is_tempfile_active(diff_temp[i].tempfile))
1722                        delete_tempfile(&diff_temp[i].tempfile);
1723                diff_temp[i].name = NULL;
1724        }
1725}
1726
1727static void add_line_count(struct strbuf *out, int count)
1728{
1729        switch (count) {
1730        case 0:
1731                strbuf_addstr(out, "0,0");
1732                break;
1733        case 1:
1734                strbuf_addstr(out, "1");
1735                break;
1736        default:
1737                strbuf_addf(out, "1,%d", count);
1738                break;
1739        }
1740}
1741
1742static void emit_rewrite_lines(struct emit_callback *ecb,
1743                               int prefix, const char *data, int size)
1744{
1745        const char *endp = NULL;
1746        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1747
1748        while (0 < size) {
1749                int len;
1750
1751                endp = memchr(data, '\n', size);
1752                len = endp ? (endp - data + 1) : size;
1753                if (prefix != '+') {
1754                        ecb->lno_in_preimage++;
1755                        emit_del_line(reset, ecb, data, len);
1756                } else {
1757                        ecb->lno_in_postimage++;
1758                        emit_add_line(reset, ecb, data, len);
1759                }
1760                size -= len;
1761                data += len;
1762        }
1763        if (!endp)
1764                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1765}
1766
1767static void emit_rewrite_diff(const char *name_a,
1768                              const char *name_b,
1769                              struct diff_filespec *one,
1770                              struct diff_filespec *two,
1771                              struct userdiff_driver *textconv_one,
1772                              struct userdiff_driver *textconv_two,
1773                              struct diff_options *o)
1774{
1775        int lc_a, lc_b;
1776        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1777        const char *a_prefix, *b_prefix;
1778        char *data_one, *data_two;
1779        size_t size_one, size_two;
1780        struct emit_callback ecbdata;
1781        struct strbuf out = STRBUF_INIT;
1782
1783        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1784                a_prefix = o->b_prefix;
1785                b_prefix = o->a_prefix;
1786        } else {
1787                a_prefix = o->a_prefix;
1788                b_prefix = o->b_prefix;
1789        }
1790
1791        name_a += (*name_a == '/');
1792        name_b += (*name_b == '/');
1793
1794        strbuf_reset(&a_name);
1795        strbuf_reset(&b_name);
1796        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1797        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1798
1799        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1800        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1801
1802        memset(&ecbdata, 0, sizeof(ecbdata));
1803        ecbdata.color_diff = want_color(o->use_color);
1804        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1805        ecbdata.opt = o;
1806        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1807                mmfile_t mf1, mf2;
1808                mf1.ptr = (char *)data_one;
1809                mf2.ptr = (char *)data_two;
1810                mf1.size = size_one;
1811                mf2.size = size_two;
1812                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1813        }
1814        ecbdata.lno_in_preimage = 1;
1815        ecbdata.lno_in_postimage = 1;
1816
1817        lc_a = count_lines(data_one, size_one);
1818        lc_b = count_lines(data_two, size_two);
1819
1820        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1821                         a_name.buf, a_name.len, 0);
1822        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1823                         b_name.buf, b_name.len, 0);
1824
1825        strbuf_addstr(&out, "@@ -");
1826        if (!o->irreversible_delete)
1827                add_line_count(&out, lc_a);
1828        else
1829                strbuf_addstr(&out, "?,?");
1830        strbuf_addstr(&out, " +");
1831        add_line_count(&out, lc_b);
1832        strbuf_addstr(&out, " @@\n");
1833        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1834        strbuf_release(&out);
1835
1836        if (lc_a && !o->irreversible_delete)
1837                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1838        if (lc_b)
1839                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1840        if (textconv_one)
1841                free((char *)data_one);
1842        if (textconv_two)
1843                free((char *)data_two);
1844}
1845
1846struct diff_words_buffer {
1847        mmfile_t text;
1848        unsigned long alloc;
1849        struct diff_words_orig {
1850                const char *begin, *end;
1851        } *orig;
1852        int orig_nr, orig_alloc;
1853};
1854
1855static void diff_words_append(char *line, unsigned long len,
1856                struct diff_words_buffer *buffer)
1857{
1858        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1859        line++;
1860        len--;
1861        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1862        buffer->text.size += len;
1863        buffer->text.ptr[buffer->text.size] = '\0';
1864}
1865
1866struct diff_words_style_elem {
1867        const char *prefix;
1868        const char *suffix;
1869        const char *color; /* NULL; filled in by the setup code if
1870                            * color is enabled */
1871};
1872
1873struct diff_words_style {
1874        enum diff_words_type type;
1875        struct diff_words_style_elem new_word, old_word, ctx;
1876        const char *newline;
1877};
1878
1879static struct diff_words_style diff_words_styles[] = {
1880        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1881        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1882        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1883};
1884
1885struct diff_words_data {
1886        struct diff_words_buffer minus, plus;
1887        const char *current_plus;
1888        int last_minus;
1889        struct diff_options *opt;
1890        regex_t *word_regex;
1891        enum diff_words_type type;
1892        struct diff_words_style *style;
1893};
1894
1895static int fn_out_diff_words_write_helper(struct diff_options *o,
1896                                          struct diff_words_style_elem *st_el,
1897                                          const char *newline,
1898                                          size_t count, const char *buf)
1899{
1900        int print = 0;
1901        struct strbuf sb = STRBUF_INIT;
1902
1903        while (count) {
1904                char *p = memchr(buf, '\n', count);
1905                if (print)
1906                        strbuf_addstr(&sb, diff_line_prefix(o));
1907
1908                if (p != buf) {
1909                        const char *reset = st_el->color && *st_el->color ?
1910                                            GIT_COLOR_RESET : NULL;
1911                        if (st_el->color && *st_el->color)
1912                                strbuf_addstr(&sb, st_el->color);
1913                        strbuf_addstr(&sb, st_el->prefix);
1914                        strbuf_add(&sb, buf, p ? p - buf : count);
1915                        strbuf_addstr(&sb, st_el->suffix);
1916                        if (reset)
1917                                strbuf_addstr(&sb, reset);
1918                }
1919                if (!p)
1920                        goto out;
1921
1922                strbuf_addstr(&sb, newline);
1923                count -= p + 1 - buf;
1924                buf = p + 1;
1925                print = 1;
1926                if (count) {
1927                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1928                                         sb.buf, sb.len, 0);
1929                        strbuf_reset(&sb);
1930                }
1931        }
1932
1933out:
1934        if (sb.len)
1935                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1936                                 sb.buf, sb.len, 0);
1937        strbuf_release(&sb);
1938        return 0;
1939}
1940
1941/*
1942 * '--color-words' algorithm can be described as:
1943 *
1944 *   1. collect the minus/plus lines of a diff hunk, divided into
1945 *      minus-lines and plus-lines;
1946 *
1947 *   2. break both minus-lines and plus-lines into words and
1948 *      place them into two mmfile_t with one word for each line;
1949 *
1950 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1951 *
1952 * And for the common parts of the both file, we output the plus side text.
1953 * diff_words->current_plus is used to trace the current position of the plus file
1954 * which printed. diff_words->last_minus is used to trace the last minus word
1955 * printed.
1956 *
1957 * For '--graph' to work with '--color-words', we need to output the graph prefix
1958 * on each line of color words output. Generally, there are two conditions on
1959 * which we should output the prefix.
1960 *
1961 *   1. diff_words->last_minus == 0 &&
1962 *      diff_words->current_plus == diff_words->plus.text.ptr
1963 *
1964 *      that is: the plus text must start as a new line, and if there is no minus
1965 *      word printed, a graph prefix must be printed.
1966 *
1967 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1968 *      *(diff_words->current_plus - 1) == '\n'
1969 *
1970 *      that is: a graph prefix must be printed following a '\n'
1971 */
1972static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1973{
1974        if ((diff_words->last_minus == 0 &&
1975                diff_words->current_plus == diff_words->plus.text.ptr) ||
1976                (diff_words->current_plus > diff_words->plus.text.ptr &&
1977                *(diff_words->current_plus - 1) == '\n')) {
1978                return 1;
1979        } else {
1980                return 0;
1981        }
1982}
1983
1984static void fn_out_diff_words_aux(void *priv,
1985                                  long minus_first, long minus_len,
1986                                  long plus_first, long plus_len,
1987                                  const char *func, long funclen)
1988{
1989        struct diff_words_data *diff_words = priv;
1990        struct diff_words_style *style = diff_words->style;
1991        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1992        struct diff_options *opt = diff_words->opt;
1993        const char *line_prefix;
1994
1995        assert(opt);
1996        line_prefix = diff_line_prefix(opt);
1997
1998        /* POSIX requires that first be decremented by one if len == 0... */
1999        if (minus_len) {
2000                minus_begin = diff_words->minus.orig[minus_first].begin;
2001                minus_end =
2002                        diff_words->minus.orig[minus_first + minus_len - 1].end;
2003        } else
2004                minus_begin = minus_end =
2005                        diff_words->minus.orig[minus_first].end;
2006
2007        if (plus_len) {
2008                plus_begin = diff_words->plus.orig[plus_first].begin;
2009                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
2010        } else
2011                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
2012
2013        if (color_words_output_graph_prefix(diff_words)) {
2014                fputs(line_prefix, diff_words->opt->file);
2015        }
2016        if (diff_words->current_plus != plus_begin) {
2017                fn_out_diff_words_write_helper(diff_words->opt,
2018                                &style->ctx, style->newline,
2019                                plus_begin - diff_words->current_plus,
2020                                diff_words->current_plus);
2021        }
2022        if (minus_begin != minus_end) {
2023                fn_out_diff_words_write_helper(diff_words->opt,
2024                                &style->old_word, style->newline,
2025                                minus_end - minus_begin, minus_begin);
2026        }
2027        if (plus_begin != plus_end) {
2028                fn_out_diff_words_write_helper(diff_words->opt,
2029                                &style->new_word, style->newline,
2030                                plus_end - plus_begin, plus_begin);
2031        }
2032
2033        diff_words->current_plus = plus_end;
2034        diff_words->last_minus = minus_first;
2035}
2036
2037/* This function starts looking at *begin, and returns 0 iff a word was found. */
2038static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
2039                int *begin, int *end)
2040{
2041        if (word_regex && *begin < buffer->size) {
2042                regmatch_t match[1];
2043                if (!regexec_buf(word_regex, buffer->ptr + *begin,
2044                                 buffer->size - *begin, 1, match, 0)) {
2045                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
2046                                        '\n', match[0].rm_eo - match[0].rm_so);
2047                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
2048                        *begin += match[0].rm_so;
2049                        return *begin >= *end;
2050                }
2051                return -1;
2052        }
2053
2054        /* find the next word */
2055        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
2056                (*begin)++;
2057        if (*begin >= buffer->size)
2058                return -1;
2059
2060        /* find the end of the word */
2061        *end = *begin + 1;
2062        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
2063                (*end)++;
2064
2065        return 0;
2066}
2067
2068/*
2069 * This function splits the words in buffer->text, stores the list with
2070 * newline separator into out, and saves the offsets of the original words
2071 * in buffer->orig.
2072 */
2073static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2074                regex_t *word_regex)
2075{
2076        int i, j;
2077        long alloc = 0;
2078
2079        out->size = 0;
2080        out->ptr = NULL;
2081
2082        /* fake an empty "0th" word */
2083        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2084        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2085        buffer->orig_nr = 1;
2086
2087        for (i = 0; i < buffer->text.size; i++) {
2088                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2089                        return;
2090
2091                /* store original boundaries */
2092                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2093                                buffer->orig_alloc);
2094                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2095                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2096                buffer->orig_nr++;
2097
2098                /* store one word */
2099                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2100                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2101                out->ptr[out->size + j - i] = '\n';
2102                out->size += j - i + 1;
2103
2104                i = j - 1;
2105        }
2106}
2107
2108/* this executes the word diff on the accumulated buffers */
2109static void diff_words_show(struct diff_words_data *diff_words)
2110{
2111        xpparam_t xpp;
2112        xdemitconf_t xecfg;
2113        mmfile_t minus, plus;
2114        struct diff_words_style *style = diff_words->style;
2115
2116        struct diff_options *opt = diff_words->opt;
2117        const char *line_prefix;
2118
2119        assert(opt);
2120        line_prefix = diff_line_prefix(opt);
2121
2122        /* special case: only removal */
2123        if (!diff_words->plus.text.size) {
2124                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2125                                 line_prefix, strlen(line_prefix), 0);
2126                fn_out_diff_words_write_helper(diff_words->opt,
2127                        &style->old_word, style->newline,
2128                        diff_words->minus.text.size,
2129                        diff_words->minus.text.ptr);
2130                diff_words->minus.text.size = 0;
2131                return;
2132        }
2133
2134        diff_words->current_plus = diff_words->plus.text.ptr;
2135        diff_words->last_minus = 0;
2136
2137        memset(&xpp, 0, sizeof(xpp));
2138        memset(&xecfg, 0, sizeof(xecfg));
2139        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2140        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2141        xpp.flags = 0;
2142        /* as only the hunk header will be parsed, we need a 0-context */
2143        xecfg.ctxlen = 0;
2144        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2145                          diff_words, &xpp, &xecfg))
2146                die("unable to generate word diff");
2147        free(minus.ptr);
2148        free(plus.ptr);
2149        if (diff_words->current_plus != diff_words->plus.text.ptr +
2150                        diff_words->plus.text.size) {
2151                if (color_words_output_graph_prefix(diff_words))
2152                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2153                                         line_prefix, strlen(line_prefix), 0);
2154                fn_out_diff_words_write_helper(diff_words->opt,
2155                        &style->ctx, style->newline,
2156                        diff_words->plus.text.ptr + diff_words->plus.text.size
2157                        - diff_words->current_plus, diff_words->current_plus);
2158        }
2159        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2160}
2161
2162/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2163static void diff_words_flush(struct emit_callback *ecbdata)
2164{
2165        struct diff_options *wo = ecbdata->diff_words->opt;
2166
2167        if (ecbdata->diff_words->minus.text.size ||
2168            ecbdata->diff_words->plus.text.size)
2169                diff_words_show(ecbdata->diff_words);
2170
2171        if (wo->emitted_symbols) {
2172                struct diff_options *o = ecbdata->opt;
2173                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2174                int i;
2175
2176                /*
2177                 * NEEDSWORK:
2178                 * Instead of appending each, concat all words to a line?
2179                 */
2180                for (i = 0; i < wol->nr; i++)
2181                        append_emitted_diff_symbol(o, &wol->buf[i]);
2182
2183                for (i = 0; i < wol->nr; i++)
2184                        free((void *)wol->buf[i].line);
2185
2186                wol->nr = 0;
2187        }
2188}
2189
2190static void diff_filespec_load_driver(struct diff_filespec *one,
2191                                      struct index_state *istate)
2192{
2193        /* Use already-loaded driver */
2194        if (one->driver)
2195                return;
2196
2197        if (S_ISREG(one->mode))
2198                one->driver = userdiff_find_by_path(istate, one->path);
2199
2200        /* Fallback to default settings */
2201        if (!one->driver)
2202                one->driver = userdiff_find_by_name("default");
2203}
2204
2205static const char *userdiff_word_regex(struct diff_filespec *one,
2206                                       struct index_state *istate)
2207{
2208        diff_filespec_load_driver(one, istate);
2209        return one->driver->word_regex;
2210}
2211
2212static void init_diff_words_data(struct emit_callback *ecbdata,
2213                                 struct diff_options *orig_opts,
2214                                 struct diff_filespec *one,
2215                                 struct diff_filespec *two)
2216{
2217        int i;
2218        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2219        memcpy(o, orig_opts, sizeof(struct diff_options));
2220
2221        ecbdata->diff_words =
2222                xcalloc(1, sizeof(struct diff_words_data));
2223        ecbdata->diff_words->type = o->word_diff;
2224        ecbdata->diff_words->opt = o;
2225
2226        if (orig_opts->emitted_symbols)
2227                o->emitted_symbols =
2228                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2229
2230        if (!o->word_regex)
2231                o->word_regex = userdiff_word_regex(one, o->repo->index);
2232        if (!o->word_regex)
2233                o->word_regex = userdiff_word_regex(two, o->repo->index);
2234        if (!o->word_regex)
2235                o->word_regex = diff_word_regex_cfg;
2236        if (o->word_regex) {
2237                ecbdata->diff_words->word_regex = (regex_t *)
2238                        xmalloc(sizeof(regex_t));
2239                if (regcomp(ecbdata->diff_words->word_regex,
2240                            o->word_regex,
2241                            REG_EXTENDED | REG_NEWLINE))
2242                        die("invalid regular expression: %s",
2243                            o->word_regex);
2244        }
2245        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2246                if (o->word_diff == diff_words_styles[i].type) {
2247                        ecbdata->diff_words->style =
2248                                &diff_words_styles[i];
2249                        break;
2250                }
2251        }
2252        if (want_color(o->use_color)) {
2253                struct diff_words_style *st = ecbdata->diff_words->style;
2254                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2255                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2256                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2257        }
2258}
2259
2260static void free_diff_words_data(struct emit_callback *ecbdata)
2261{
2262        if (ecbdata->diff_words) {
2263                diff_words_flush(ecbdata);
2264                free (ecbdata->diff_words->opt->emitted_symbols);
2265                free (ecbdata->diff_words->opt);
2266                free (ecbdata->diff_words->minus.text.ptr);
2267                free (ecbdata->diff_words->minus.orig);
2268                free (ecbdata->diff_words->plus.text.ptr);
2269                free (ecbdata->diff_words->plus.orig);
2270                if (ecbdata->diff_words->word_regex) {
2271                        regfree(ecbdata->diff_words->word_regex);
2272                        free(ecbdata->diff_words->word_regex);
2273                }
2274                FREE_AND_NULL(ecbdata->diff_words);
2275        }
2276}
2277
2278const char *diff_get_color(int diff_use_color, enum color_diff ix)
2279{
2280        if (want_color(diff_use_color))
2281                return diff_colors[ix];
2282        return "";
2283}
2284
2285const char *diff_line_prefix(struct diff_options *opt)
2286{
2287        struct strbuf *msgbuf;
2288        if (!opt->output_prefix)
2289                return "";
2290
2291        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2292        return msgbuf->buf;
2293}
2294
2295static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2296{
2297        const char *cp;
2298        unsigned long allot;
2299        size_t l = len;
2300
2301        cp = line;
2302        allot = l;
2303        while (0 < l) {
2304                (void) utf8_width(&cp, &l);
2305                if (!cp)
2306                        break; /* truncated in the middle? */
2307        }
2308        return allot - l;
2309}
2310
2311static void find_lno(const char *line, struct emit_callback *ecbdata)
2312{
2313        const char *p;
2314        ecbdata->lno_in_preimage = 0;
2315        ecbdata->lno_in_postimage = 0;
2316        p = strchr(line, '-');
2317        if (!p)
2318                return; /* cannot happen */
2319        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2320        p = strchr(p, '+');
2321        if (!p)
2322                return; /* cannot happen */
2323        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2324}
2325
2326static void fn_out_consume(void *priv, char *line, unsigned long len)
2327{
2328        struct emit_callback *ecbdata = priv;
2329        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2330        struct diff_options *o = ecbdata->opt;
2331
2332        o->found_changes = 1;
2333
2334        if (ecbdata->header) {
2335                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2336                                 ecbdata->header->buf, ecbdata->header->len, 0);
2337                strbuf_reset(ecbdata->header);
2338                ecbdata->header = NULL;
2339        }
2340
2341        if (ecbdata->label_path[0]) {
2342                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2343                                 ecbdata->label_path[0],
2344                                 strlen(ecbdata->label_path[0]), 0);
2345                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2346                                 ecbdata->label_path[1],
2347                                 strlen(ecbdata->label_path[1]), 0);
2348                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2349        }
2350
2351        if (diff_suppress_blank_empty
2352            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2353                line[0] = '\n';
2354                len = 1;
2355        }
2356
2357        if (line[0] == '@') {
2358                if (ecbdata->diff_words)
2359                        diff_words_flush(ecbdata);
2360                len = sane_truncate_line(ecbdata, line, len);
2361                find_lno(line, ecbdata);
2362                emit_hunk_header(ecbdata, line, len);
2363                return;
2364        }
2365
2366        if (ecbdata->diff_words) {
2367                enum diff_symbol s =
2368                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2369                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2370                if (line[0] == '-') {
2371                        diff_words_append(line, len,
2372                                          &ecbdata->diff_words->minus);
2373                        return;
2374                } else if (line[0] == '+') {
2375                        diff_words_append(line, len,
2376                                          &ecbdata->diff_words->plus);
2377                        return;
2378                } else if (starts_with(line, "\\ ")) {
2379                        /*
2380                         * Eat the "no newline at eof" marker as if we
2381                         * saw a "+" or "-" line with nothing on it,
2382                         * and return without diff_words_flush() to
2383                         * defer processing. If this is the end of
2384                         * preimage, more "+" lines may come after it.
2385                         */
2386                        return;
2387                }
2388                diff_words_flush(ecbdata);
2389                emit_diff_symbol(o, s, line, len, 0);
2390                return;
2391        }
2392
2393        switch (line[0]) {
2394        case '+':
2395                ecbdata->lno_in_postimage++;
2396                emit_add_line(reset, ecbdata, line + 1, len - 1);
2397                break;
2398        case '-':
2399                ecbdata->lno_in_preimage++;
2400                emit_del_line(reset, ecbdata, line + 1, len - 1);
2401                break;
2402        case ' ':
2403                ecbdata->lno_in_postimage++;
2404                ecbdata->lno_in_preimage++;
2405                emit_context_line(reset, ecbdata, line + 1, len - 1);
2406                break;
2407        default:
2408                /* incomplete line at the end */
2409                ecbdata->lno_in_preimage++;
2410                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2411                                 line, len, 0);
2412                break;
2413        }
2414}
2415
2416static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2417{
2418        const char *old_name = a;
2419        const char *new_name = b;
2420        int pfx_length, sfx_length;
2421        int pfx_adjust_for_slash;
2422        int len_a = strlen(a);
2423        int len_b = strlen(b);
2424        int a_midlen, b_midlen;
2425        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2426        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2427
2428        if (qlen_a || qlen_b) {
2429                quote_c_style(a, name, NULL, 0);
2430                strbuf_addstr(name, " => ");
2431                quote_c_style(b, name, NULL, 0);
2432                return;
2433        }
2434
2435        /* Find common prefix */
2436        pfx_length = 0;
2437        while (*old_name && *new_name && *old_name == *new_name) {
2438                if (*old_name == '/')
2439                        pfx_length = old_name - a + 1;
2440                old_name++;
2441                new_name++;
2442        }
2443
2444        /* Find common suffix */
2445        old_name = a + len_a;
2446        new_name = b + len_b;
2447        sfx_length = 0;
2448        /*
2449         * If there is a common prefix, it must end in a slash.  In
2450         * that case we let this loop run 1 into the prefix to see the
2451         * same slash.
2452         *
2453         * If there is no common prefix, we cannot do this as it would
2454         * underrun the input strings.
2455         */
2456        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2457        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2458               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2459               *old_name == *new_name) {
2460                if (*old_name == '/')
2461                        sfx_length = len_a - (old_name - a);
2462                old_name--;
2463                new_name--;
2464        }
2465
2466        /*
2467         * pfx{mid-a => mid-b}sfx
2468         * {pfx-a => pfx-b}sfx
2469         * pfx{sfx-a => sfx-b}
2470         * name-a => name-b
2471         */
2472        a_midlen = len_a - pfx_length - sfx_length;
2473        b_midlen = len_b - pfx_length - sfx_length;
2474        if (a_midlen < 0)
2475                a_midlen = 0;
2476        if (b_midlen < 0)
2477                b_midlen = 0;
2478
2479        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2480        if (pfx_length + sfx_length) {
2481                strbuf_add(name, a, pfx_length);
2482                strbuf_addch(name, '{');
2483        }
2484        strbuf_add(name, a + pfx_length, a_midlen);
2485        strbuf_addstr(name, " => ");
2486        strbuf_add(name, b + pfx_length, b_midlen);
2487        if (pfx_length + sfx_length) {
2488                strbuf_addch(name, '}');
2489                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2490        }
2491}
2492
2493struct diffstat_t {
2494        int nr;
2495        int alloc;
2496        struct diffstat_file {
2497                char *from_name;
2498                char *name;
2499                char *print_name;
2500                const char *comments;
2501                unsigned is_unmerged:1;
2502                unsigned is_binary:1;
2503                unsigned is_renamed:1;
2504                unsigned is_interesting:1;
2505                uintmax_t added, deleted;
2506        } **files;
2507};
2508
2509static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2510                                          const char *name_a,
2511                                          const char *name_b)
2512{
2513        struct diffstat_file *x;
2514        x = xcalloc(1, sizeof(*x));
2515        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2516        diffstat->files[diffstat->nr++] = x;
2517        if (name_b) {
2518                x->from_name = xstrdup(name_a);
2519                x->name = xstrdup(name_b);
2520                x->is_renamed = 1;
2521        }
2522        else {
2523                x->from_name = NULL;
2524                x->name = xstrdup(name_a);
2525        }
2526        return x;
2527}
2528
2529static void diffstat_consume(void *priv, char *line, unsigned long len)
2530{
2531        struct diffstat_t *diffstat = priv;
2532        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2533
2534        if (line[0] == '+')
2535                x->added++;
2536        else if (line[0] == '-')
2537                x->deleted++;
2538}
2539
2540const char mime_boundary_leader[] = "------------";
2541
2542static int scale_linear(int it, int width, int max_change)
2543{
2544        if (!it)
2545                return 0;
2546        /*
2547         * make sure that at least one '-' or '+' is printed if
2548         * there is any change to this path. The easiest way is to
2549         * scale linearly as if the alloted width is one column shorter
2550         * than it is, and then add 1 to the result.
2551         */
2552        return 1 + (it * (width - 1) / max_change);
2553}
2554
2555static void show_graph(struct strbuf *out, char ch, int cnt,
2556                       const char *set, const char *reset)
2557{
2558        if (cnt <= 0)
2559                return;
2560        strbuf_addstr(out, set);
2561        strbuf_addchars(out, ch, cnt);
2562        strbuf_addstr(out, reset);
2563}
2564
2565static void fill_print_name(struct diffstat_file *file)
2566{
2567        struct strbuf pname = STRBUF_INIT;
2568
2569        if (file->print_name)
2570                return;
2571
2572        if (file->is_renamed)
2573                pprint_rename(&pname, file->from_name, file->name);
2574        else
2575                quote_c_style(file->name, &pname, NULL, 0);
2576
2577        if (file->comments)
2578                strbuf_addf(&pname, " (%s)", file->comments);
2579
2580        file->print_name = strbuf_detach(&pname, NULL);
2581}
2582
2583static void print_stat_summary_inserts_deletes(struct diff_options *options,
2584                int files, int insertions, int deletions)
2585{
2586        struct strbuf sb = STRBUF_INIT;
2587
2588        if (!files) {
2589                assert(insertions == 0 && deletions == 0);
2590                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2591                                 NULL, 0, 0);
2592                return;
2593        }
2594
2595        strbuf_addf(&sb,
2596                    (files == 1) ? " %d file changed" : " %d files changed",
2597                    files);
2598
2599        /*
2600         * For binary diff, the caller may want to print "x files
2601         * changed" with insertions == 0 && deletions == 0.
2602         *
2603         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2604         * is probably less confusing (i.e skip over "2 files changed
2605         * but nothing about added/removed lines? Is this a bug in Git?").
2606         */
2607        if (insertions || deletions == 0) {
2608                strbuf_addf(&sb,
2609                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2610                            insertions);
2611        }
2612
2613        if (deletions || insertions == 0) {
2614                strbuf_addf(&sb,
2615                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2616                            deletions);
2617        }
2618        strbuf_addch(&sb, '\n');
2619        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2620                         sb.buf, sb.len, 0);
2621        strbuf_release(&sb);
2622}
2623
2624void print_stat_summary(FILE *fp, int files,
2625                        int insertions, int deletions)
2626{
2627        struct diff_options o;
2628        memset(&o, 0, sizeof(o));
2629        o.file = fp;
2630
2631        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2632}
2633
2634static void show_stats(struct diffstat_t *data, struct diff_options *options)
2635{
2636        int i, len, add, del, adds = 0, dels = 0;
2637        uintmax_t max_change = 0, max_len = 0;
2638        int total_files = data->nr, count;
2639        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2640        const char *reset, *add_c, *del_c;
2641        int extra_shown = 0;
2642        const char *line_prefix = diff_line_prefix(options);
2643        struct strbuf out = STRBUF_INIT;
2644
2645        if (data->nr == 0)
2646                return;
2647
2648        count = options->stat_count ? options->stat_count : data->nr;
2649
2650        reset = diff_get_color_opt(options, DIFF_RESET);
2651        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2652        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2653
2654        /*
2655         * Find the longest filename and max number of changes
2656         */
2657        for (i = 0; (i < count) && (i < data->nr); i++) {
2658                struct diffstat_file *file = data->files[i];
2659                uintmax_t change = file->added + file->deleted;
2660
2661                if (!file->is_interesting && (change == 0)) {
2662                        count++; /* not shown == room for one more */
2663                        continue;
2664                }
2665                fill_print_name(file);
2666                len = strlen(file->print_name);
2667                if (max_len < len)
2668                        max_len = len;
2669
2670                if (file->is_unmerged) {
2671                        /* "Unmerged" is 8 characters */
2672                        bin_width = bin_width < 8 ? 8 : bin_width;
2673                        continue;
2674                }
2675                if (file->is_binary) {
2676                        /* "Bin XXX -> YYY bytes" */
2677                        int w = 14 + decimal_width(file->added)
2678                                + decimal_width(file->deleted);
2679                        bin_width = bin_width < w ? w : bin_width;
2680                        /* Display change counts aligned with "Bin" */
2681                        number_width = 3;
2682                        continue;
2683                }
2684
2685                if (max_change < change)
2686                        max_change = change;
2687        }
2688        count = i; /* where we can stop scanning in data->files[] */
2689
2690        /*
2691         * We have width = stat_width or term_columns() columns total.
2692         * We want a maximum of min(max_len, stat_name_width) for the name part.
2693         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2694         * We also need 1 for " " and 4 + decimal_width(max_change)
2695         * for " | NNNN " and one the empty column at the end, altogether
2696         * 6 + decimal_width(max_change).
2697         *
2698         * If there's not enough space, we will use the smaller of
2699         * stat_name_width (if set) and 5/8*width for the filename,
2700         * and the rest for constant elements + graph part, but no more
2701         * than stat_graph_width for the graph part.
2702         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2703         * for the standard terminal size).
2704         *
2705         * In other words: stat_width limits the maximum width, and
2706         * stat_name_width fixes the maximum width of the filename,
2707         * and is also used to divide available columns if there
2708         * aren't enough.
2709         *
2710         * Binary files are displayed with "Bin XXX -> YYY bytes"
2711         * instead of the change count and graph. This part is treated
2712         * similarly to the graph part, except that it is not
2713         * "scaled". If total width is too small to accommodate the
2714         * guaranteed minimum width of the filename part and the
2715         * separators and this message, this message will "overflow"
2716         * making the line longer than the maximum width.
2717         */
2718
2719        if (options->stat_width == -1)
2720                width = term_columns() - strlen(line_prefix);
2721        else
2722                width = options->stat_width ? options->stat_width : 80;
2723        number_width = decimal_width(max_change) > number_width ?
2724                decimal_width(max_change) : number_width;
2725
2726        if (options->stat_graph_width == -1)
2727                options->stat_graph_width = diff_stat_graph_width;
2728
2729        /*
2730         * Guarantee 3/8*16==6 for the graph part
2731         * and 5/8*16==10 for the filename part
2732         */
2733        if (width < 16 + 6 + number_width)
2734                width = 16 + 6 + number_width;
2735
2736        /*
2737         * First assign sizes that are wanted, ignoring available width.
2738         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2739         * starting from "XXX" should fit in graph_width.
2740         */
2741        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2742        if (options->stat_graph_width &&
2743            options->stat_graph_width < graph_width)
2744                graph_width = options->stat_graph_width;
2745
2746        name_width = (options->stat_name_width > 0 &&
2747                      options->stat_name_width < max_len) ?
2748                options->stat_name_width : max_len;
2749
2750        /*
2751         * Adjust adjustable widths not to exceed maximum width
2752         */
2753        if (name_width + number_width + 6 + graph_width > width) {
2754                if (graph_width > width * 3/8 - number_width - 6) {
2755                        graph_width = width * 3/8 - number_width - 6;
2756                        if (graph_width < 6)
2757                                graph_width = 6;
2758                }
2759
2760                if (options->stat_graph_width &&
2761                    graph_width > options->stat_graph_width)
2762                        graph_width = options->stat_graph_width;
2763                if (name_width > width - number_width - 6 - graph_width)
2764                        name_width = width - number_width - 6 - graph_width;
2765                else
2766                        graph_width = width - number_width - 6 - name_width;
2767        }
2768
2769        /*
2770         * From here name_width is the width of the name area,
2771         * and graph_width is the width of the graph area.
2772         * max_change is used to scale graph properly.
2773         */
2774        for (i = 0; i < count; i++) {
2775                const char *prefix = "";
2776                struct diffstat_file *file = data->files[i];
2777                char *name = file->print_name;
2778                uintmax_t added = file->added;
2779                uintmax_t deleted = file->deleted;
2780                int name_len;
2781
2782                if (!file->is_interesting && (added + deleted == 0))
2783                        continue;
2784
2785                /*
2786                 * "scale" the filename
2787                 */
2788                len = name_width;
2789                name_len = strlen(name);
2790                if (name_width < name_len) {
2791                        char *slash;
2792                        prefix = "...";
2793                        len -= 3;
2794                        name += name_len - len;
2795                        slash = strchr(name, '/');
2796                        if (slash)
2797                                name = slash;
2798                }
2799
2800                if (file->is_binary) {
2801                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2802                        strbuf_addf(&out, " %*s", number_width, "Bin");
2803                        if (!added && !deleted) {
2804                                strbuf_addch(&out, '\n');
2805                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2806                                                 out.buf, out.len, 0);
2807                                strbuf_reset(&out);
2808                                continue;
2809                        }
2810                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2811                                del_c, deleted, reset);
2812                        strbuf_addstr(&out, " -> ");
2813                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2814                                add_c, added, reset);
2815                        strbuf_addstr(&out, " bytes\n");
2816                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2817                                         out.buf, out.len, 0);
2818                        strbuf_reset(&out);
2819                        continue;
2820                }
2821                else if (file->is_unmerged) {
2822                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2823                        strbuf_addstr(&out, " Unmerged\n");
2824                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2825                                         out.buf, out.len, 0);
2826                        strbuf_reset(&out);
2827                        continue;
2828                }
2829
2830                /*
2831                 * scale the add/delete
2832                 */
2833                add = added;
2834                del = deleted;
2835
2836                if (graph_width <= max_change) {
2837                        int total = scale_linear(add + del, graph_width, max_change);
2838                        if (total < 2 && add && del)
2839                                /* width >= 2 due to the sanity check */
2840                                total = 2;
2841                        if (add < del) {
2842                                add = scale_linear(add, graph_width, max_change);
2843                                del = total - add;
2844                        } else {
2845                                del = scale_linear(del, graph_width, max_change);
2846                                add = total - del;
2847                        }
2848                }
2849                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2850                strbuf_addf(&out, " %*"PRIuMAX"%s",
2851                        number_width, added + deleted,
2852                        added + deleted ? " " : "");
2853                show_graph(&out, '+', add, add_c, reset);
2854                show_graph(&out, '-', del, del_c, reset);
2855                strbuf_addch(&out, '\n');
2856                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2857                                 out.buf, out.len, 0);
2858                strbuf_reset(&out);
2859        }
2860
2861        for (i = 0; i < data->nr; i++) {
2862                struct diffstat_file *file = data->files[i];
2863                uintmax_t added = file->added;
2864                uintmax_t deleted = file->deleted;
2865
2866                if (file->is_unmerged ||
2867                    (!file->is_interesting && (added + deleted == 0))) {
2868                        total_files--;
2869                        continue;
2870                }
2871
2872                if (!file->is_binary) {
2873                        adds += added;
2874                        dels += deleted;
2875                }
2876                if (i < count)
2877                        continue;
2878                if (!extra_shown)
2879                        emit_diff_symbol(options,
2880                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2881                                         NULL, 0, 0);
2882                extra_shown = 1;
2883        }
2884
2885        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2886        strbuf_release(&out);
2887}
2888
2889static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2890{
2891        int i, adds = 0, dels = 0, total_files = data->nr;
2892
2893        if (data->nr == 0)
2894                return;
2895
2896        for (i = 0; i < data->nr; i++) {
2897                int added = data->files[i]->added;
2898                int deleted = data->files[i]->deleted;
2899
2900                if (data->files[i]->is_unmerged ||
2901                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2902                        total_files--;
2903                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2904                        adds += added;
2905                        dels += deleted;
2906                }
2907        }
2908        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2909}
2910
2911static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2912{
2913        int i;
2914
2915        if (data->nr == 0)
2916                return;
2917
2918        for (i = 0; i < data->nr; i++) {
2919                struct diffstat_file *file = data->files[i];
2920
2921                fprintf(options->file, "%s", diff_line_prefix(options));
2922
2923                if (file->is_binary)
2924                        fprintf(options->file, "-\t-\t");
2925                else
2926                        fprintf(options->file,
2927                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2928                                file->added, file->deleted);
2929                if (options->line_termination) {
2930                        fill_print_name(file);
2931                        if (!file->is_renamed)
2932                                write_name_quoted(file->name, options->file,
2933                                                  options->line_termination);
2934                        else {
2935                                fputs(file->print_name, options->file);
2936                                putc(options->line_termination, options->file);
2937                        }
2938                } else {
2939                        if (file->is_renamed) {
2940                                putc('\0', options->file);
2941                                write_name_quoted(file->from_name, options->file, '\0');
2942                        }
2943                        write_name_quoted(file->name, options->file, '\0');
2944                }
2945        }
2946}
2947
2948struct dirstat_file {
2949        const char *name;
2950        unsigned long changed;
2951};
2952
2953struct dirstat_dir {
2954        struct dirstat_file *files;
2955        int alloc, nr, permille, cumulative;
2956};
2957
2958static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2959                unsigned long changed, const char *base, int baselen)
2960{
2961        unsigned long sum_changes = 0;
2962        unsigned int sources = 0;
2963        const char *line_prefix = diff_line_prefix(opt);
2964
2965        while (dir->nr) {
2966                struct dirstat_file *f = dir->files;
2967                int namelen = strlen(f->name);
2968                unsigned long changes;
2969                char *slash;
2970
2971                if (namelen < baselen)
2972                        break;
2973                if (memcmp(f->name, base, baselen))
2974                        break;
2975                slash = strchr(f->name + baselen, '/');
2976                if (slash) {
2977                        int newbaselen = slash + 1 - f->name;
2978                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2979                        sources++;
2980                } else {
2981                        changes = f->changed;
2982                        dir->files++;
2983                        dir->nr--;
2984                        sources += 2;
2985                }
2986                sum_changes += changes;
2987        }
2988
2989        /*
2990         * We don't report dirstat's for
2991         *  - the top level
2992         *  - or cases where everything came from a single directory
2993         *    under this directory (sources == 1).
2994         */
2995        if (baselen && sources != 1) {
2996                if (sum_changes) {
2997                        int permille = sum_changes * 1000 / changed;
2998                        if (permille >= dir->permille) {
2999                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
3000                                        permille / 10, permille % 10, baselen, base);
3001                                if (!dir->cumulative)
3002                                        return 0;
3003                        }
3004                }
3005        }
3006        return sum_changes;
3007}
3008
3009static int dirstat_compare(const void *_a, const void *_b)
3010{
3011        const struct dirstat_file *a = _a;
3012        const struct dirstat_file *b = _b;
3013        return strcmp(a->name, b->name);
3014}
3015
3016static void show_dirstat(struct diff_options *options)
3017{
3018        int i;
3019        unsigned long changed;
3020        struct dirstat_dir dir;
3021        struct diff_queue_struct *q = &diff_queued_diff;
3022
3023        dir.files = NULL;
3024        dir.alloc = 0;
3025        dir.nr = 0;
3026        dir.permille = options->dirstat_permille;
3027        dir.cumulative = options->flags.dirstat_cumulative;
3028
3029        changed = 0;
3030        for (i = 0; i < q->nr; i++) {
3031                struct diff_filepair *p = q->queue[i];
3032                const char *name;
3033                unsigned long copied, added, damage;
3034
3035                name = p->two->path ? p->two->path : p->one->path;
3036
3037                if (p->one->oid_valid && p->two->oid_valid &&
3038                    oideq(&p->one->oid, &p->two->oid)) {
3039                        /*
3040                         * The SHA1 has not changed, so pre-/post-content is
3041                         * identical. We can therefore skip looking at the
3042                         * file contents altogether.
3043                         */
3044                        damage = 0;
3045                        goto found_damage;
3046                }
3047
3048                if (options->flags.dirstat_by_file) {
3049                        /*
3050                         * In --dirstat-by-file mode, we don't really need to
3051                         * look at the actual file contents at all.
3052                         * The fact that the SHA1 changed is enough for us to
3053                         * add this file to the list of results
3054                         * (with each file contributing equal damage).
3055                         */
3056                        damage = 1;
3057                        goto found_damage;
3058                }
3059
3060                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
3061                        diff_populate_filespec(options->repo, p->one, 0);
3062                        diff_populate_filespec(options->repo, p->two, 0);
3063                        diffcore_count_changes(options->repo,
3064                                               p->one, p->two, NULL, NULL,
3065                                               &copied, &added);
3066                        diff_free_filespec_data(p->one);
3067                        diff_free_filespec_data(p->two);
3068                } else if (DIFF_FILE_VALID(p->one)) {
3069                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3070                        copied = added = 0;
3071                        diff_free_filespec_data(p->one);
3072                } else if (DIFF_FILE_VALID(p->two)) {
3073                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3074                        copied = 0;
3075                        added = p->two->size;
3076                        diff_free_filespec_data(p->two);
3077                } else
3078                        continue;
3079
3080                /*
3081                 * Original minus copied is the removed material,
3082                 * added is the new material.  They are both damages
3083                 * made to the preimage.
3084                 * If the resulting damage is zero, we know that
3085                 * diffcore_count_changes() considers the two entries to
3086                 * be identical, but since the oid changed, we
3087                 * know that there must have been _some_ kind of change,
3088                 * so we force all entries to have damage > 0.
3089                 */
3090                damage = (p->one->size - copied) + added;
3091                if (!damage)
3092                        damage = 1;
3093
3094found_damage:
3095                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3096                dir.files[dir.nr].name = name;
3097                dir.files[dir.nr].changed = damage;
3098                changed += damage;
3099                dir.nr++;
3100        }
3101
3102        /* This can happen even with many files, if everything was renames */
3103        if (!changed)
3104                return;
3105
3106        /* Show all directories with more than x% of the changes */
3107        QSORT(dir.files, dir.nr, dirstat_compare);
3108        gather_dirstat(options, &dir, changed, "", 0);
3109}
3110
3111static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3112{
3113        int i;
3114        unsigned long changed;
3115        struct dirstat_dir dir;
3116
3117        if (data->nr == 0)
3118                return;
3119
3120        dir.files = NULL;
3121        dir.alloc = 0;
3122        dir.nr = 0;
3123        dir.permille = options->dirstat_permille;
3124        dir.cumulative = options->flags.dirstat_cumulative;
3125
3126        changed = 0;
3127        for (i = 0; i < data->nr; i++) {
3128                struct diffstat_file *file = data->files[i];
3129                unsigned long damage = file->added + file->deleted;
3130                if (file->is_binary)
3131                        /*
3132                         * binary files counts bytes, not lines. Must find some
3133                         * way to normalize binary bytes vs. textual lines.
3134                         * The following heuristic assumes that there are 64
3135                         * bytes per "line".
3136                         * This is stupid and ugly, but very cheap...
3137                         */
3138                        damage = DIV_ROUND_UP(damage, 64);
3139                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3140                dir.files[dir.nr].name = file->name;
3141                dir.files[dir.nr].changed = damage;
3142                changed += damage;
3143                dir.nr++;
3144        }
3145
3146        /* This can happen even with many files, if everything was renames */
3147        if (!changed)
3148                return;
3149
3150        /* Show all directories with more than x% of the changes */
3151        QSORT(dir.files, dir.nr, dirstat_compare);
3152        gather_dirstat(options, &dir, changed, "", 0);
3153}
3154
3155static void free_diffstat_info(struct diffstat_t *diffstat)
3156{
3157        int i;
3158        for (i = 0; i < diffstat->nr; i++) {
3159                struct diffstat_file *f = diffstat->files[i];
3160                free(f->print_name);
3161                free(f->name);
3162                free(f->from_name);
3163                free(f);
3164        }
3165        free(diffstat->files);
3166}
3167
3168struct checkdiff_t {
3169        const char *filename;
3170        int lineno;
3171        int conflict_marker_size;
3172        struct diff_options *o;
3173        unsigned ws_rule;
3174        unsigned status;
3175};
3176
3177static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3178{
3179        char firstchar;
3180        int cnt;
3181
3182        if (len < marker_size + 1)
3183                return 0;
3184        firstchar = line[0];
3185        switch (firstchar) {
3186        case '=': case '>': case '<': case '|':
3187                break;
3188        default:
3189                return 0;
3190        }
3191        for (cnt = 1; cnt < marker_size; cnt++)
3192                if (line[cnt] != firstchar)
3193                        return 0;
3194        /* line[1] thru line[marker_size-1] are same as firstchar */
3195        if (len < marker_size + 1 || !isspace(line[marker_size]))
3196                return 0;
3197        return 1;
3198}
3199
3200static void checkdiff_consume_hunk(void *priv,
3201                                   long ob, long on, long nb, long nn,
3202                                   const char *func, long funclen)
3203
3204{
3205        struct checkdiff_t *data = priv;
3206        data->lineno = nb - 1;
3207}
3208
3209static void checkdiff_consume(void *priv, char *line, unsigned long len)
3210{
3211        struct checkdiff_t *data = priv;
3212        int marker_size = data->conflict_marker_size;
3213        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3214        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3215        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3216        char *err;
3217        const char *line_prefix;
3218
3219        assert(data->o);
3220        line_prefix = diff_line_prefix(data->o);
3221
3222        if (line[0] == '+') {
3223                unsigned bad;
3224                data->lineno++;
3225                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3226                        data->status |= 1;
3227                        fprintf(data->o->file,
3228                                "%s%s:%d: leftover conflict marker\n",
3229                                line_prefix, data->filename, data->lineno);
3230                }
3231                bad = ws_check(line + 1, len - 1, data->ws_rule);
3232                if (!bad)
3233                        return;
3234                data->status |= bad;
3235                err = whitespace_error_string(bad);
3236                fprintf(data->o->file, "%s%s:%d: %s.\n",
3237                        line_prefix, data->filename, data->lineno, err);
3238                free(err);
3239                emit_line(data->o, set, reset, line, 1);
3240                ws_check_emit(line + 1, len - 1, data->ws_rule,
3241                              data->o->file, set, reset, ws);
3242        } else if (line[0] == ' ') {
3243                data->lineno++;
3244        }
3245}
3246
3247static unsigned char *deflate_it(char *data,
3248                                 unsigned long size,
3249                                 unsigned long *result_size)
3250{
3251        int bound;
3252        unsigned char *deflated;
3253        git_zstream stream;
3254
3255        git_deflate_init(&stream, zlib_compression_level);
3256        bound = git_deflate_bound(&stream, size);
3257        deflated = xmalloc(bound);
3258        stream.next_out = deflated;
3259        stream.avail_out = bound;
3260
3261        stream.next_in = (unsigned char *)data;
3262        stream.avail_in = size;
3263        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3264                ; /* nothing */
3265        git_deflate_end(&stream);
3266        *result_size = stream.total_out;
3267        return deflated;
3268}
3269
3270static void emit_binary_diff_body(struct diff_options *o,
3271                                  mmfile_t *one, mmfile_t *two)
3272{
3273        void *cp;
3274        void *delta;
3275        void *deflated;
3276        void *data;
3277        unsigned long orig_size;
3278        unsigned long delta_size;
3279        unsigned long deflate_size;
3280        unsigned long data_size;
3281
3282        /* We could do deflated delta, or we could do just deflated two,
3283         * whichever is smaller.
3284         */
3285        delta = NULL;
3286        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3287        if (one->size && two->size) {
3288                delta = diff_delta(one->ptr, one->size,
3289                                   two->ptr, two->size,
3290                                   &delta_size, deflate_size);
3291                if (delta) {
3292                        void *to_free = delta;
3293                        orig_size = delta_size;
3294                        delta = deflate_it(delta, delta_size, &delta_size);
3295                        free(to_free);
3296                }
3297        }
3298
3299        if (delta && delta_size < deflate_size) {
3300                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3301                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3302                                 s, strlen(s), 0);
3303                free(s);
3304                free(deflated);
3305                data = delta;
3306                data_size = delta_size;
3307        } else {
3308                char *s = xstrfmt("%lu", two->size);
3309                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3310                                 s, strlen(s), 0);
3311                free(s);
3312                free(delta);
3313                data = deflated;
3314                data_size = deflate_size;
3315        }
3316
3317        /* emit data encoded in base85 */
3318        cp = data;
3319        while (data_size) {
3320                int len;
3321                int bytes = (52 < data_size) ? 52 : data_size;
3322                char line[71];
3323                data_size -= bytes;
3324                if (bytes <= 26)
3325                        line[0] = bytes + 'A' - 1;
3326                else
3327                        line[0] = bytes - 26 + 'a' - 1;
3328                encode_85(line + 1, cp, bytes);
3329                cp = (char *) cp + bytes;
3330
3331                len = strlen(line);
3332                line[len++] = '\n';
3333                line[len] = '\0';
3334
3335                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3336                                 line, len, 0);
3337        }
3338        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3339        free(data);
3340}
3341
3342static void emit_binary_diff(struct diff_options *o,
3343                             mmfile_t *one, mmfile_t *two)
3344{
3345        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3346        emit_binary_diff_body(o, one, two);
3347        emit_binary_diff_body(o, two, one);
3348}
3349
3350int diff_filespec_is_binary(struct repository *r,
3351                            struct diff_filespec *one)
3352{
3353        if (one->is_binary == -1) {
3354                diff_filespec_load_driver(one, r->index);
3355                if (one->driver->binary != -1)
3356                        one->is_binary = one->driver->binary;
3357                else {
3358                        if (!one->data && DIFF_FILE_VALID(one))
3359                                diff_populate_filespec(r, one, CHECK_BINARY);
3360                        if (one->is_binary == -1 && one->data)
3361                                one->is_binary = buffer_is_binary(one->data,
3362                                                one->size);
3363                        if (one->is_binary == -1)
3364                                one->is_binary = 0;
3365                }
3366        }
3367        return one->is_binary;
3368}
3369
3370static const struct userdiff_funcname *
3371diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3372{
3373        diff_filespec_load_driver(one, o->repo->index);
3374        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3375}
3376
3377void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3378{
3379        if (!options->a_prefix)
3380                options->a_prefix = a;
3381        if (!options->b_prefix)
3382                options->b_prefix = b;
3383}
3384
3385struct userdiff_driver *get_textconv(struct repository *r,
3386                                     struct diff_filespec *one)
3387{
3388        if (!DIFF_FILE_VALID(one))
3389                return NULL;
3390
3391        diff_filespec_load_driver(one, r->index);
3392        return userdiff_get_textconv(r, one->driver);
3393}
3394
3395static void builtin_diff(const char *name_a,
3396                         const char *name_b,
3397                         struct diff_filespec *one,
3398                         struct diff_filespec *two,
3399                         const char *xfrm_msg,
3400                         int must_show_header,
3401                         struct diff_options *o,
3402                         int complete_rewrite)
3403{
3404        mmfile_t mf1, mf2;
3405        const char *lbl[2];
3406        char *a_one, *b_two;
3407        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3408        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3409        const char *a_prefix, *b_prefix;
3410        struct userdiff_driver *textconv_one = NULL;
3411        struct userdiff_driver *textconv_two = NULL;
3412        struct strbuf header = STRBUF_INIT;
3413        const char *line_prefix = diff_line_prefix(o);
3414
3415        diff_set_mnemonic_prefix(o, "a/", "b/");
3416        if (o->flags.reverse_diff) {
3417                a_prefix = o->b_prefix;
3418                b_prefix = o->a_prefix;
3419        } else {
3420                a_prefix = o->a_prefix;
3421                b_prefix = o->b_prefix;
3422        }
3423
3424        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3425            (!one->mode || S_ISGITLINK(one->mode)) &&
3426            (!two->mode || S_ISGITLINK(two->mode))) {
3427                show_submodule_summary(o, one->path ? one->path : two->path,
3428                                &one->oid, &two->oid,
3429                                two->dirty_submodule);
3430                return;
3431        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3432                   (!one->mode || S_ISGITLINK(one->mode)) &&
3433                   (!two->mode || S_ISGITLINK(two->mode))) {
3434                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3435                                &one->oid, &two->oid,
3436                                two->dirty_submodule);
3437                return;
3438        }
3439
3440        if (o->flags.allow_textconv) {
3441                textconv_one = get_textconv(o->repo, one);
3442                textconv_two = get_textconv(o->repo, two);
3443        }
3444
3445        /* Never use a non-valid filename anywhere if at all possible */
3446        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3447        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3448
3449        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3450        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3451        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3452        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3453        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3454        if (lbl[0][0] == '/') {
3455                /* /dev/null */
3456                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3457                if (xfrm_msg)
3458                        strbuf_addstr(&header, xfrm_msg);
3459                must_show_header = 1;
3460        }
3461        else if (lbl[1][0] == '/') {
3462                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3463                if (xfrm_msg)
3464                        strbuf_addstr(&header, xfrm_msg);
3465                must_show_header = 1;
3466        }
3467        else {
3468                if (one->mode != two->mode) {
3469                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3470                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3471                        must_show_header = 1;
3472                }
3473                if (xfrm_msg)
3474                        strbuf_addstr(&header, xfrm_msg);
3475
3476                /*
3477                 * we do not run diff between different kind
3478                 * of objects.
3479                 */
3480                if ((one->mode ^ two->mode) & S_IFMT)
3481                        goto free_ab_and_return;
3482                if (complete_rewrite &&
3483                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3484                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3485                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3486                                         header.buf, header.len, 0);
3487                        strbuf_reset(&header);
3488                        emit_rewrite_diff(name_a, name_b, one, two,
3489                                          textconv_one, textconv_two, o);
3490                        o->found_changes = 1;
3491                        goto free_ab_and_return;
3492                }
3493        }
3494
3495        if (o->irreversible_delete && lbl[1][0] == '/') {
3496                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3497                                 header.len, 0);
3498                strbuf_reset(&header);
3499                goto free_ab_and_return;
3500        } else if (!o->flags.text &&
3501                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3502                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3503                struct strbuf sb = STRBUF_INIT;
3504                if (!one->data && !two->data &&
3505                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3506                    !o->flags.binary) {
3507                        if (oideq(&one->oid, &two->oid)) {
3508                                if (must_show_header)
3509                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3510                                                         header.buf, header.len,
3511                                                         0);
3512                                goto free_ab_and_return;
3513                        }
3514                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3515                                         header.buf, header.len, 0);
3516                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3517                                    diff_line_prefix(o), lbl[0], lbl[1]);
3518                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3519                                         sb.buf, sb.len, 0);
3520                        strbuf_release(&sb);
3521                        goto free_ab_and_return;
3522                }
3523                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3524                    fill_mmfile(o->repo, &mf2, two) < 0)
3525                        die("unable to read files to diff");
3526                /* Quite common confusing case */
3527                if (mf1.size == mf2.size &&
3528                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3529                        if (must_show_header)
3530                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3531                                                 header.buf, header.len, 0);
3532                        goto free_ab_and_return;
3533                }
3534                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3535                strbuf_reset(&header);
3536                if (o->flags.binary)
3537                        emit_binary_diff(o, &mf1, &mf2);
3538                else {
3539                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3540                                    diff_line_prefix(o), lbl[0], lbl[1]);
3541                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3542                                         sb.buf, sb.len, 0);
3543                        strbuf_release(&sb);
3544                }
3545                o->found_changes = 1;
3546        } else {
3547                /* Crazy xdl interfaces.. */
3548                const char *diffopts;
3549                const char *v;
3550                xpparam_t xpp;
3551                xdemitconf_t xecfg;
3552                struct emit_callback ecbdata;
3553                const struct userdiff_funcname *pe;
3554
3555                if (must_show_header) {
3556                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3557                                         header.buf, header.len, 0);
3558                        strbuf_reset(&header);
3559                }
3560
3561                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3562                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3563
3564                pe = diff_funcname_pattern(o, one);
3565                if (!pe)
3566                        pe = diff_funcname_pattern(o, two);
3567
3568                memset(&xpp, 0, sizeof(xpp));
3569                memset(&xecfg, 0, sizeof(xecfg));
3570                memset(&ecbdata, 0, sizeof(ecbdata));
3571                if (o->flags.suppress_diff_headers)
3572                        lbl[0] = NULL;
3573                ecbdata.label_path = lbl;
3574                ecbdata.color_diff = want_color(o->use_color);
3575                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3576                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3577                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3578                ecbdata.opt = o;
3579                if (header.len && !o->flags.suppress_diff_headers)
3580                        ecbdata.header = &header;
3581                xpp.flags = o->xdl_opts;
3582                xpp.anchors = o->anchors;
3583                xpp.anchors_nr = o->anchors_nr;
3584                xecfg.ctxlen = o->context;
3585                xecfg.interhunkctxlen = o->interhunkcontext;
3586                xecfg.flags = XDL_EMIT_FUNCNAMES;
3587                if (o->flags.funccontext)
3588                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3589                if (pe)
3590                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3591
3592                diffopts = getenv("GIT_DIFF_OPTS");
3593                if (!diffopts)
3594                        ;
3595                else if (skip_prefix(diffopts, "--unified=", &v))
3596                        xecfg.ctxlen = strtoul(v, NULL, 10);
3597                else if (skip_prefix(diffopts, "-u", &v))
3598                        xecfg.ctxlen = strtoul(v, NULL, 10);
3599
3600                if (o->word_diff)
3601                        init_diff_words_data(&ecbdata, o, one, two);
3602                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3603                                  &ecbdata, &xpp, &xecfg))
3604                        die("unable to generate diff for %s", one->path);
3605                if (o->word_diff)
3606                        free_diff_words_data(&ecbdata);
3607                if (textconv_one)
3608                        free(mf1.ptr);
3609                if (textconv_two)
3610                        free(mf2.ptr);
3611                xdiff_clear_find_func(&xecfg);
3612        }
3613
3614 free_ab_and_return:
3615        strbuf_release(&header);
3616        diff_free_filespec_data(one);
3617        diff_free_filespec_data(two);
3618        free(a_one);
3619        free(b_two);
3620        return;
3621}
3622
3623static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3624{
3625        if (!is_renamed) {
3626                if (p->status == DIFF_STATUS_ADDED) {
3627                        if (S_ISLNK(p->two->mode))
3628                                return "new +l";
3629                        else if ((p->two->mode & 0777) == 0755)
3630                                return "new +x";
3631                        else
3632                                return "new";
3633                } else if (p->status == DIFF_STATUS_DELETED)
3634                        return "gone";
3635        }
3636        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3637                return "mode -l";
3638        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3639                return "mode +l";
3640        else if ((p->one->mode & 0777) == 0644 &&
3641                 (p->two->mode & 0777) == 0755)
3642                return "mode +x";
3643        else if ((p->one->mode & 0777) == 0755 &&
3644                 (p->two->mode & 0777) == 0644)
3645                return "mode -x";
3646        return NULL;
3647}
3648
3649static void builtin_diffstat(const char *name_a, const char *name_b,
3650                             struct diff_filespec *one,
3651                             struct diff_filespec *two,
3652                             struct diffstat_t *diffstat,
3653                             struct diff_options *o,
3654                             struct diff_filepair *p)
3655{
3656        mmfile_t mf1, mf2;
3657        struct diffstat_file *data;
3658        int same_contents;
3659        int complete_rewrite = 0;
3660
3661        if (!DIFF_PAIR_UNMERGED(p)) {
3662                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3663                        complete_rewrite = 1;
3664        }
3665
3666        data = diffstat_add(diffstat, name_a, name_b);
3667        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3668        if (o->flags.stat_with_summary)
3669                data->comments = get_compact_summary(p, data->is_renamed);
3670
3671        if (!one || !two) {
3672                data->is_unmerged = 1;
3673                return;
3674        }
3675
3676        same_contents = oideq(&one->oid, &two->oid);
3677
3678        if (diff_filespec_is_binary(o->repo, one) ||
3679            diff_filespec_is_binary(o->repo, two)) {
3680                data->is_binary = 1;
3681                if (same_contents) {
3682                        data->added = 0;
3683                        data->deleted = 0;
3684                } else {
3685                        data->added = diff_filespec_size(o->repo, two);
3686                        data->deleted = diff_filespec_size(o->repo, one);
3687                }
3688        }
3689
3690        else if (complete_rewrite) {
3691                diff_populate_filespec(o->repo, one, 0);
3692                diff_populate_filespec(o->repo, two, 0);
3693                data->deleted = count_lines(one->data, one->size);
3694                data->added = count_lines(two->data, two->size);
3695        }
3696
3697        else if (!same_contents) {
3698                /* Crazy xdl interfaces.. */
3699                xpparam_t xpp;
3700                xdemitconf_t xecfg;
3701
3702                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3703                    fill_mmfile(o->repo, &mf2, two) < 0)
3704                        die("unable to read files to diff");
3705
3706                memset(&xpp, 0, sizeof(xpp));
3707                memset(&xecfg, 0, sizeof(xecfg));
3708                xpp.flags = o->xdl_opts;
3709                xpp.anchors = o->anchors;
3710                xpp.anchors_nr = o->anchors_nr;
3711                xecfg.ctxlen = o->context;
3712                xecfg.interhunkctxlen = o->interhunkcontext;
3713                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3714                                  diffstat_consume, diffstat, &xpp, &xecfg))
3715                        die("unable to generate diffstat for %s", one->path);
3716        }
3717
3718        diff_free_filespec_data(one);
3719        diff_free_filespec_data(two);
3720}
3721
3722static void builtin_checkdiff(const char *name_a, const char *name_b,
3723                              const char *attr_path,
3724                              struct diff_filespec *one,
3725                              struct diff_filespec *two,
3726                              struct diff_options *o)
3727{
3728        mmfile_t mf1, mf2;
3729        struct checkdiff_t data;
3730
3731        if (!two)
3732                return;
3733
3734        memset(&data, 0, sizeof(data));
3735        data.filename = name_b ? name_b : name_a;
3736        data.lineno = 0;
3737        data.o = o;
3738        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3739        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3740
3741        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3742            fill_mmfile(o->repo, &mf2, two) < 0)
3743                die("unable to read files to diff");
3744
3745        /*
3746         * All the other codepaths check both sides, but not checking
3747         * the "old" side here is deliberate.  We are checking the newly
3748         * introduced changes, and as long as the "new" side is text, we
3749         * can and should check what it introduces.
3750         */
3751        if (diff_filespec_is_binary(o->repo, two))
3752                goto free_and_return;
3753        else {
3754                /* Crazy xdl interfaces.. */
3755                xpparam_t xpp;
3756                xdemitconf_t xecfg;
3757
3758                memset(&xpp, 0, sizeof(xpp));
3759                memset(&xecfg, 0, sizeof(xecfg));
3760                xecfg.ctxlen = 1; /* at least one context line */
3761                xpp.flags = 0;
3762                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3763                                  checkdiff_consume, &data,
3764                                  &xpp, &xecfg))
3765                        die("unable to generate checkdiff for %s", one->path);
3766
3767                if (data.ws_rule & WS_BLANK_AT_EOF) {
3768                        struct emit_callback ecbdata;
3769                        int blank_at_eof;
3770
3771                        ecbdata.ws_rule = data.ws_rule;
3772                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3773                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3774
3775                        if (blank_at_eof) {
3776                                static char *err;
3777                                if (!err)
3778                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3779                                fprintf(o->file, "%s:%d: %s.\n",
3780                                        data.filename, blank_at_eof, err);
3781                                data.status = 1; /* report errors */
3782                        }
3783                }
3784        }
3785 free_and_return:
3786        diff_free_filespec_data(one);
3787        diff_free_filespec_data(two);
3788        if (data.status)
3789                o->flags.check_failed = 1;
3790}
3791
3792struct diff_filespec *alloc_filespec(const char *path)
3793{
3794        struct diff_filespec *spec;
3795
3796        FLEXPTR_ALLOC_STR(spec, path, path);
3797        spec->count = 1;
3798        spec->is_binary = -1;
3799        return spec;
3800}
3801
3802void free_filespec(struct diff_filespec *spec)
3803{
3804        if (!--spec->count) {
3805                diff_free_filespec_data(spec);
3806                free(spec);
3807        }
3808}
3809
3810void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3811                   int oid_valid, unsigned short mode)
3812{
3813        if (mode) {
3814                spec->mode = canon_mode(mode);
3815                oidcpy(&spec->oid, oid);
3816                spec->oid_valid = oid_valid;
3817        }
3818}
3819
3820/*
3821 * Given a name and sha1 pair, if the index tells us the file in
3822 * the work tree has that object contents, return true, so that
3823 * prepare_temp_file() does not have to inflate and extract.
3824 */
3825static int reuse_worktree_file(struct index_state *istate,
3826                               const char *name,
3827                               const struct object_id *oid,
3828                               int want_file)
3829{
3830        const struct cache_entry *ce;
3831        struct stat st;
3832        int pos, len;
3833
3834        /*
3835         * We do not read the cache ourselves here, because the
3836         * benchmark with my previous version that always reads cache
3837         * shows that it makes things worse for diff-tree comparing
3838         * two linux-2.6 kernel trees in an already checked out work
3839         * tree.  This is because most diff-tree comparisons deal with
3840         * only a small number of files, while reading the cache is
3841         * expensive for a large project, and its cost outweighs the
3842         * savings we get by not inflating the object to a temporary
3843         * file.  Practically, this code only helps when we are used
3844         * by diff-cache --cached, which does read the cache before
3845         * calling us.
3846         */
3847        if (!istate->cache)
3848                return 0;
3849
3850        /* We want to avoid the working directory if our caller
3851         * doesn't need the data in a normal file, this system
3852         * is rather slow with its stat/open/mmap/close syscalls,
3853         * and the object is contained in a pack file.  The pack
3854         * is probably already open and will be faster to obtain
3855         * the data through than the working directory.  Loose
3856         * objects however would tend to be slower as they need
3857         * to be individually opened and inflated.
3858         */
3859        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3860                return 0;
3861
3862        /*
3863         * Similarly, if we'd have to convert the file contents anyway, that
3864         * makes the optimization not worthwhile.
3865         */
3866        if (!want_file && would_convert_to_git(istate, name))
3867                return 0;
3868
3869        len = strlen(name);
3870        pos = index_name_pos(istate, name, len);
3871        if (pos < 0)
3872                return 0;
3873        ce = istate->cache[pos];
3874
3875        /*
3876         * This is not the sha1 we are looking for, or
3877         * unreusable because it is not a regular file.
3878         */
3879        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3880                return 0;
3881
3882        /*
3883         * If ce is marked as "assume unchanged", there is no
3884         * guarantee that work tree matches what we are looking for.
3885         */
3886        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3887                return 0;
3888
3889        /*
3890         * If ce matches the file in the work tree, we can reuse it.
3891         */
3892        if (ce_uptodate(ce) ||
3893            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3894                return 1;
3895
3896        return 0;
3897}
3898
3899static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3900{
3901        struct strbuf buf = STRBUF_INIT;
3902        char *dirty = "";
3903
3904        /* Are we looking at the work tree? */
3905        if (s->dirty_submodule)
3906                dirty = "-dirty";
3907
3908        strbuf_addf(&buf, "Subproject commit %s%s\n",
3909                    oid_to_hex(&s->oid), dirty);
3910        s->size = buf.len;
3911        if (size_only) {
3912                s->data = NULL;
3913                strbuf_release(&buf);
3914        } else {
3915                s->data = strbuf_detach(&buf, NULL);
3916                s->should_free = 1;
3917        }
3918        return 0;
3919}
3920
3921/*
3922 * While doing rename detection and pickaxe operation, we may need to
3923 * grab the data for the blob (or file) for our own in-core comparison.
3924 * diff_filespec has data and size fields for this purpose.
3925 */
3926int diff_populate_filespec(struct repository *r,
3927                           struct diff_filespec *s,
3928                           unsigned int flags)
3929{
3930        int size_only = flags & CHECK_SIZE_ONLY;
3931        int err = 0;
3932        int conv_flags = global_conv_flags_eol;
3933        /*
3934         * demote FAIL to WARN to allow inspecting the situation
3935         * instead of refusing.
3936         */
3937        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3938                conv_flags = CONV_EOL_RNDTRP_WARN;
3939
3940        if (!DIFF_FILE_VALID(s))
3941                die("internal error: asking to populate invalid file.");
3942        if (S_ISDIR(s->mode))
3943                return -1;
3944
3945        if (s->data)
3946                return 0;
3947
3948        if (size_only && 0 < s->size)
3949                return 0;
3950
3951        if (S_ISGITLINK(s->mode))
3952                return diff_populate_gitlink(s, size_only);
3953
3954        if (!s->oid_valid ||
3955            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3956                struct strbuf buf = STRBUF_INIT;
3957                struct stat st;
3958                int fd;
3959
3960                if (lstat(s->path, &st) < 0) {
3961                err_empty:
3962                        err = -1;
3963                empty:
3964                        s->data = (char *)"";
3965                        s->size = 0;
3966                        return err;
3967                }
3968                s->size = xsize_t(st.st_size);
3969                if (!s->size)
3970                        goto empty;
3971                if (S_ISLNK(st.st_mode)) {
3972                        struct strbuf sb = STRBUF_INIT;
3973
3974                        if (strbuf_readlink(&sb, s->path, s->size))
3975                                goto err_empty;
3976                        s->size = sb.len;
3977                        s->data = strbuf_detach(&sb, NULL);
3978                        s->should_free = 1;
3979                        return 0;
3980                }
3981
3982                /*
3983                 * Even if the caller would be happy with getting
3984                 * only the size, we cannot return early at this
3985                 * point if the path requires us to run the content
3986                 * conversion.
3987                 */
3988                if (size_only && !would_convert_to_git(r->index, s->path))
3989                        return 0;
3990
3991                /*
3992                 * Note: this check uses xsize_t(st.st_size) that may
3993                 * not be the true size of the blob after it goes
3994                 * through convert_to_git().  This may not strictly be
3995                 * correct, but the whole point of big_file_threshold
3996                 * and is_binary check being that we want to avoid
3997                 * opening the file and inspecting the contents, this
3998                 * is probably fine.
3999                 */
4000                if ((flags & CHECK_BINARY) &&
4001                    s->size > big_file_threshold && s->is_binary == -1) {
4002                        s->is_binary = 1;
4003                        return 0;
4004                }
4005                fd = open(s->path, O_RDONLY);
4006                if (fd < 0)
4007                        goto err_empty;
4008                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
4009                close(fd);
4010                s->should_munmap = 1;
4011
4012                /*
4013                 * Convert from working tree format to canonical git format
4014                 */
4015                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
4016                        size_t size = 0;
4017                        munmap(s->data, s->size);
4018                        s->should_munmap = 0;
4019                        s->data = strbuf_detach(&buf, &size);
4020                        s->size = size;
4021                        s->should_free = 1;
4022                }
4023        }
4024        else {
4025                enum object_type type;
4026                if (size_only || (flags & CHECK_BINARY)) {
4027                        type = oid_object_info(r, &s->oid, &s->size);
4028                        if (type < 0)
4029                                die("unable to read %s",
4030                                    oid_to_hex(&s->oid));
4031                        if (size_only)
4032                                return 0;
4033                        if (s->size > big_file_threshold && s->is_binary == -1) {
4034                                s->is_binary = 1;
4035                                return 0;
4036                        }
4037                }
4038                s->data = read_object_file(&s->oid, &type, &s->size);
4039                if (!s->data)
4040                        die("unable to read %s", oid_to_hex(&s->oid));
4041                s->should_free = 1;
4042        }
4043        return 0;
4044}
4045
4046void diff_free_filespec_blob(struct diff_filespec *s)
4047{
4048        if (s->should_free)
4049                free(s->data);
4050        else if (s->should_munmap)
4051                munmap(s->data, s->size);
4052
4053        if (s->should_free || s->should_munmap) {
4054                s->should_free = s->should_munmap = 0;
4055                s->data = NULL;
4056        }
4057}
4058
4059void diff_free_filespec_data(struct diff_filespec *s)
4060{
4061        diff_free_filespec_blob(s);
4062        FREE_AND_NULL(s->cnt_data);
4063}
4064
4065static void prep_temp_blob(struct index_state *istate,
4066                           const char *path, struct diff_tempfile *temp,
4067                           void *blob,
4068                           unsigned long size,
4069                           const struct object_id *oid,
4070                           int mode)
4071{
4072        struct strbuf buf = STRBUF_INIT;
4073        struct strbuf tempfile = STRBUF_INIT;
4074        char *path_dup = xstrdup(path);
4075        const char *base = basename(path_dup);
4076
4077        /* Generate "XXXXXX_basename.ext" */
4078        strbuf_addstr(&tempfile, "XXXXXX_");
4079        strbuf_addstr(&tempfile, base);
4080
4081        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4082        if (!temp->tempfile)
4083                die_errno("unable to create temp-file");
4084        if (convert_to_working_tree(istate, path,
4085                        (const char *)blob, (size_t)size, &buf)) {
4086                blob = buf.buf;
4087                size = buf.len;
4088        }
4089        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4090            close_tempfile_gently(temp->tempfile))
4091                die_errno("unable to write temp-file");
4092        temp->name = get_tempfile_path(temp->tempfile);
4093        oid_to_hex_r(temp->hex, oid);
4094        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4095        strbuf_release(&buf);
4096        strbuf_release(&tempfile);
4097        free(path_dup);
4098}
4099
4100static struct diff_tempfile *prepare_temp_file(struct repository *r,
4101                                               const char *name,
4102                                               struct diff_filespec *one)
4103{
4104        struct diff_tempfile *temp = claim_diff_tempfile();
4105
4106        if (!DIFF_FILE_VALID(one)) {
4107        not_a_valid_file:
4108                /* A '-' entry produces this for file-2, and
4109                 * a '+' entry produces this for file-1.
4110                 */
4111                temp->name = "/dev/null";
4112                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4113                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4114                return temp;
4115        }
4116
4117        if (!S_ISGITLINK(one->mode) &&
4118            (!one->oid_valid ||
4119             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4120                struct stat st;
4121                if (lstat(name, &st) < 0) {
4122                        if (errno == ENOENT)
4123                                goto not_a_valid_file;
4124                        die_errno("stat(%s)", name);
4125                }
4126                if (S_ISLNK(st.st_mode)) {
4127                        struct strbuf sb = STRBUF_INIT;
4128                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4129                                die_errno("readlink(%s)", name);
4130                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4131                                       (one->oid_valid ?
4132                                        &one->oid : &null_oid),
4133                                       (one->oid_valid ?
4134                                        one->mode : S_IFLNK));
4135                        strbuf_release(&sb);
4136                }
4137                else {
4138                        /* we can borrow from the file in the work tree */
4139                        temp->name = name;
4140                        if (!one->oid_valid)
4141                                oid_to_hex_r(temp->hex, &null_oid);
4142                        else
4143                                oid_to_hex_r(temp->hex, &one->oid);
4144                        /* Even though we may sometimes borrow the
4145                         * contents from the work tree, we always want
4146                         * one->mode.  mode is trustworthy even when
4147                         * !(one->oid_valid), as long as
4148                         * DIFF_FILE_VALID(one).
4149                         */
4150                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4151                }
4152                return temp;
4153        }
4154        else {
4155                if (diff_populate_filespec(r, one, 0))
4156                        die("cannot read data blob for %s", one->path);
4157                prep_temp_blob(r->index, name, temp,
4158                               one->data, one->size,
4159                               &one->oid, one->mode);
4160        }
4161        return temp;
4162}
4163
4164static void add_external_diff_name(struct repository *r,
4165                                   struct argv_array *argv,
4166                                   const char *name,
4167                                   struct diff_filespec *df)
4168{
4169        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4170        argv_array_push(argv, temp->name);
4171        argv_array_push(argv, temp->hex);
4172        argv_array_push(argv, temp->mode);
4173}
4174
4175/* An external diff command takes:
4176 *
4177 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4178 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4179 *
4180 */
4181static void run_external_diff(const char *pgm,
4182                              const char *name,
4183                              const char *other,
4184                              struct diff_filespec *one,
4185                              struct diff_filespec *two,
4186                              const char *xfrm_msg,
4187                              int complete_rewrite,
4188                              struct diff_options *o)
4189{
4190        struct argv_array argv = ARGV_ARRAY_INIT;
4191        struct argv_array env = ARGV_ARRAY_INIT;
4192        struct diff_queue_struct *q = &diff_queued_diff;
4193
4194        argv_array_push(&argv, pgm);
4195        argv_array_push(&argv, name);
4196
4197        if (one && two) {
4198                add_external_diff_name(o->repo, &argv, name, one);
4199                if (!other)
4200                        add_external_diff_name(o->repo, &argv, name, two);
4201                else {
4202                        add_external_diff_name(o->repo, &argv, other, two);
4203                        argv_array_push(&argv, other);
4204                        argv_array_push(&argv, xfrm_msg);
4205                }
4206        }
4207
4208        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4209        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4210
4211        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4212                die(_("external diff died, stopping at %s"), name);
4213
4214        remove_tempfile();
4215        argv_array_clear(&argv);
4216        argv_array_clear(&env);
4217}
4218
4219static int similarity_index(struct diff_filepair *p)
4220{
4221        return p->score * 100 / MAX_SCORE;
4222}
4223
4224static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4225{
4226        if (startup_info->have_repository)
4227                return find_unique_abbrev(oid, abbrev);
4228        else {
4229                char *hex = oid_to_hex(oid);
4230                if (abbrev < 0)
4231                        abbrev = FALLBACK_DEFAULT_ABBREV;
4232                if (abbrev > the_hash_algo->hexsz)
4233                        BUG("oid abbreviation out of range: %d", abbrev);
4234                if (abbrev)
4235                        hex[abbrev] = '\0';
4236                return hex;
4237        }
4238}
4239
4240static void fill_metainfo(struct strbuf *msg,
4241                          const char *name,
4242                          const char *other,
4243                          struct diff_filespec *one,
4244                          struct diff_filespec *two,
4245                          struct diff_options *o,
4246                          struct diff_filepair *p,
4247                          int *must_show_header,
4248                          int use_color)
4249{
4250        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4251        const char *reset = diff_get_color(use_color, DIFF_RESET);
4252        const char *line_prefix = diff_line_prefix(o);
4253
4254        *must_show_header = 1;
4255        strbuf_init(msg, PATH_MAX * 2 + 300);
4256        switch (p->status) {
4257        case DIFF_STATUS_COPIED:
4258                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4259                            line_prefix, set, similarity_index(p));
4260                strbuf_addf(msg, "%s\n%s%scopy from ",
4261                            reset,  line_prefix, set);
4262                quote_c_style(name, msg, NULL, 0);
4263                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4264                quote_c_style(other, msg, NULL, 0);
4265                strbuf_addf(msg, "%s\n", reset);
4266                break;
4267        case DIFF_STATUS_RENAMED:
4268                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4269                            line_prefix, set, similarity_index(p));
4270                strbuf_addf(msg, "%s\n%s%srename from ",
4271                            reset, line_prefix, set);
4272                quote_c_style(name, msg, NULL, 0);
4273                strbuf_addf(msg, "%s\n%s%srename to ",
4274                            reset, line_prefix, set);
4275                quote_c_style(other, msg, NULL, 0);
4276                strbuf_addf(msg, "%s\n", reset);
4277                break;
4278        case DIFF_STATUS_MODIFIED:
4279                if (p->score) {
4280                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4281                                    line_prefix,
4282                                    set, similarity_index(p), reset);
4283                        break;
4284                }
4285                /* fallthru */
4286        default:
4287                *must_show_header = 0;
4288        }
4289        if (one && two && !oideq(&one->oid, &two->oid)) {
4290                const unsigned hexsz = the_hash_algo->hexsz;
4291                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4292
4293                if (o->flags.binary) {
4294                        mmfile_t mf;
4295                        if ((!fill_mmfile(o->repo, &mf, one) &&
4296                             diff_filespec_is_binary(o->repo, one)) ||
4297                            (!fill_mmfile(o->repo, &mf, two) &&
4298                             diff_filespec_is_binary(o->repo, two)))
4299                                abbrev = hexsz;
4300                }
4301                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4302                            diff_abbrev_oid(&one->oid, abbrev),
4303                            diff_abbrev_oid(&two->oid, abbrev));
4304                if (one->mode == two->mode)
4305                        strbuf_addf(msg, " %06o", one->mode);
4306                strbuf_addf(msg, "%s\n", reset);
4307        }
4308}
4309
4310static void run_diff_cmd(const char *pgm,
4311                         const char *name,
4312                         const char *other,
4313                         const char *attr_path,
4314                         struct diff_filespec *one,
4315                         struct diff_filespec *two,
4316                         struct strbuf *msg,
4317                         struct diff_options *o,
4318                         struct diff_filepair *p)
4319{
4320        const char *xfrm_msg = NULL;
4321        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4322        int must_show_header = 0;
4323
4324
4325        if (o->flags.allow_external) {
4326                struct userdiff_driver *drv;
4327
4328                drv = userdiff_find_by_path(o->repo->index, attr_path);
4329                if (drv && drv->external)
4330                        pgm = drv->external;
4331        }
4332
4333        if (msg) {
4334                /*
4335                 * don't use colors when the header is intended for an
4336                 * external diff driver
4337                 */
4338                fill_metainfo(msg, name, other, one, two, o, p,
4339                              &must_show_header,
4340                              want_color(o->use_color) && !pgm);
4341                xfrm_msg = msg->len ? msg->buf : NULL;
4342        }
4343
4344        if (pgm) {
4345                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4346                                  complete_rewrite, o);
4347                return;
4348        }
4349        if (one && two)
4350                builtin_diff(name, other ? other : name,
4351                             one, two, xfrm_msg, must_show_header,
4352                             o, complete_rewrite);
4353        else
4354                fprintf(o->file, "* Unmerged path %s\n", name);
4355}
4356
4357static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4358{
4359        if (DIFF_FILE_VALID(one)) {
4360                if (!one->oid_valid) {
4361                        struct stat st;
4362                        if (one->is_stdin) {
4363                                oidclr(&one->oid);
4364                                return;
4365                        }
4366                        if (lstat(one->path, &st) < 0)
4367                                die_errno("stat '%s'", one->path);
4368                        if (index_path(istate, &one->oid, one->path, &st, 0))
4369                                die("cannot hash %s", one->path);
4370                }
4371        }
4372        else
4373                oidclr(&one->oid);
4374}
4375
4376static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4377{
4378        /* Strip the prefix but do not molest /dev/null and absolute paths */
4379        if (*namep && !is_absolute_path(*namep)) {
4380                *namep += prefix_length;
4381                if (**namep == '/')
4382                        ++*namep;
4383        }
4384        if (*otherp && !is_absolute_path(*otherp)) {
4385                *otherp += prefix_length;
4386                if (**otherp == '/')
4387                        ++*otherp;
4388        }
4389}
4390
4391static void run_diff(struct diff_filepair *p, struct diff_options *o)
4392{
4393        const char *pgm = external_diff();
4394        struct strbuf msg;
4395        struct diff_filespec *one = p->one;
4396        struct diff_filespec *two = p->two;
4397        const char *name;
4398        const char *other;
4399        const char *attr_path;
4400
4401        name  = one->path;
4402        other = (strcmp(name, two->path) ? two->path : NULL);
4403        attr_path = name;
4404        if (o->prefix_length)
4405                strip_prefix(o->prefix_length, &name, &other);
4406
4407        if (!o->flags.allow_external)
4408                pgm = NULL;
4409
4410        if (DIFF_PAIR_UNMERGED(p)) {
4411                run_diff_cmd(pgm, name, NULL, attr_path,
4412                             NULL, NULL, NULL, o, p);
4413                return;
4414        }
4415
4416        diff_fill_oid_info(one, o->repo->index);
4417        diff_fill_oid_info(two, o->repo->index);
4418
4419        if (!pgm &&
4420            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4421            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4422                /*
4423                 * a filepair that changes between file and symlink
4424                 * needs to be split into deletion and creation.
4425                 */
4426                struct diff_filespec *null = alloc_filespec(two->path);
4427                run_diff_cmd(NULL, name, other, attr_path,
4428                             one, null, &msg,
4429                             o, p);
4430                free(null);
4431                strbuf_release(&msg);
4432
4433                null = alloc_filespec(one->path);
4434                run_diff_cmd(NULL, name, other, attr_path,
4435                             null, two, &msg, o, p);
4436                free(null);
4437        }
4438        else
4439                run_diff_cmd(pgm, name, other, attr_path,
4440                             one, two, &msg, o, p);
4441
4442        strbuf_release(&msg);
4443}
4444
4445static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4446                         struct diffstat_t *diffstat)
4447{
4448        const char *name;
4449        const char *other;
4450
4451        if (DIFF_PAIR_UNMERGED(p)) {
4452                /* unmerged */
4453                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4454                                 diffstat, o, p);
4455                return;
4456        }
4457
4458        name = p->one->path;
4459        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4460
4461        if (o->prefix_length)
4462                strip_prefix(o->prefix_length, &name, &other);
4463
4464        diff_fill_oid_info(p->one, o->repo->index);
4465        diff_fill_oid_info(p->two, o->repo->index);
4466
4467        builtin_diffstat(name, other, p->one, p->two,
4468                         diffstat, o, p);
4469}
4470
4471static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4472{
4473        const char *name;
4474        const char *other;
4475        const char *attr_path;
4476
4477        if (DIFF_PAIR_UNMERGED(p)) {
4478                /* unmerged */
4479                return;
4480        }
4481
4482        name = p->one->path;
4483        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4484        attr_path = other ? other : name;
4485
4486        if (o->prefix_length)
4487                strip_prefix(o->prefix_length, &name, &other);
4488
4489        diff_fill_oid_info(p->one, o->repo->index);
4490        diff_fill_oid_info(p->two, o->repo->index);
4491
4492        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4493}
4494
4495static void prep_parse_options(struct diff_options *options);
4496
4497void repo_diff_setup(struct repository *r, struct diff_options *options)
4498{
4499        memcpy(options, &default_diff_options, sizeof(*options));
4500
4501        options->file = stdout;
4502        options->repo = r;
4503
4504        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4505        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4506        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4507        options->abbrev = DEFAULT_ABBREV;
4508        options->line_termination = '\n';
4509        options->break_opt = -1;
4510        options->rename_limit = -1;
4511        options->dirstat_permille = diff_dirstat_permille_default;
4512        options->context = diff_context_default;
4513        options->interhunkcontext = diff_interhunk_context_default;
4514        options->ws_error_highlight = ws_error_highlight_default;
4515        options->flags.rename_empty = 1;
4516        options->objfind = NULL;
4517
4518        /* pathchange left =NULL by default */
4519        options->change = diff_change;
4520        options->add_remove = diff_addremove;
4521        options->use_color = diff_use_color_default;
4522        options->detect_rename = diff_detect_rename_default;
4523        options->xdl_opts |= diff_algorithm;
4524        if (diff_indent_heuristic)
4525                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4526
4527        options->orderfile = diff_order_file_cfg;
4528
4529        if (diff_no_prefix) {
4530                options->a_prefix = options->b_prefix = "";
4531        } else if (!diff_mnemonic_prefix) {
4532                options->a_prefix = "a/";
4533                options->b_prefix = "b/";
4534        }
4535
4536        options->color_moved = diff_color_moved_default;
4537        options->color_moved_ws_handling = diff_color_moved_ws_default;
4538
4539        prep_parse_options(options);
4540}
4541
4542void diff_setup_done(struct diff_options *options)
4543{
4544        unsigned check_mask = DIFF_FORMAT_NAME |
4545                              DIFF_FORMAT_NAME_STATUS |
4546                              DIFF_FORMAT_CHECKDIFF |
4547                              DIFF_FORMAT_NO_OUTPUT;
4548        /*
4549         * This must be signed because we're comparing against a potentially
4550         * negative value.
4551         */
4552        const int hexsz = the_hash_algo->hexsz;
4553
4554        if (options->set_default)
4555                options->set_default(options);
4556
4557        if (HAS_MULTI_BITS(options->output_format & check_mask))
4558                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4559
4560        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4561                die(_("-G, -S and --find-object are mutually exclusive"));
4562
4563        /*
4564         * Most of the time we can say "there are changes"
4565         * only by checking if there are changed paths, but
4566         * --ignore-whitespace* options force us to look
4567         * inside contents.
4568         */
4569
4570        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4571                options->flags.diff_from_contents = 1;
4572        else
4573                options->flags.diff_from_contents = 0;
4574
4575        if (options->flags.find_copies_harder)
4576                options->detect_rename = DIFF_DETECT_COPY;
4577
4578        if (!options->flags.relative_name)
4579                options->prefix = NULL;
4580        if (options->prefix)
4581                options->prefix_length = strlen(options->prefix);
4582        else
4583                options->prefix_length = 0;
4584
4585        if (options->output_format & (DIFF_FORMAT_NAME |
4586                                      DIFF_FORMAT_NAME_STATUS |
4587                                      DIFF_FORMAT_CHECKDIFF |
4588                                      DIFF_FORMAT_NO_OUTPUT))
4589                options->output_format &= ~(DIFF_FORMAT_RAW |
4590                                            DIFF_FORMAT_NUMSTAT |
4591                                            DIFF_FORMAT_DIFFSTAT |
4592                                            DIFF_FORMAT_SHORTSTAT |
4593                                            DIFF_FORMAT_DIRSTAT |
4594                                            DIFF_FORMAT_SUMMARY |
4595                                            DIFF_FORMAT_PATCH);
4596
4597        /*
4598         * These cases always need recursive; we do not drop caller-supplied
4599         * recursive bits for other formats here.
4600         */
4601        if (options->output_format & (DIFF_FORMAT_PATCH |
4602                                      DIFF_FORMAT_NUMSTAT |
4603                                      DIFF_FORMAT_DIFFSTAT |
4604                                      DIFF_FORMAT_SHORTSTAT |
4605                                      DIFF_FORMAT_DIRSTAT |
4606                                      DIFF_FORMAT_SUMMARY |
4607                                      DIFF_FORMAT_CHECKDIFF))
4608                options->flags.recursive = 1;
4609        /*
4610         * Also pickaxe would not work very well if you do not say recursive
4611         */
4612        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4613                options->flags.recursive = 1;
4614        /*
4615         * When patches are generated, submodules diffed against the work tree
4616         * must be checked for dirtiness too so it can be shown in the output
4617         */
4618        if (options->output_format & DIFF_FORMAT_PATCH)
4619                options->flags.dirty_submodules = 1;
4620
4621        if (options->detect_rename && options->rename_limit < 0)
4622                options->rename_limit = diff_rename_limit_default;
4623        if (hexsz < options->abbrev)
4624                options->abbrev = hexsz; /* full */
4625
4626        /*
4627         * It does not make sense to show the first hit we happened
4628         * to have found.  It does not make sense not to return with
4629         * exit code in such a case either.
4630         */
4631        if (options->flags.quick) {
4632                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4633                options->flags.exit_with_status = 1;
4634        }
4635
4636        options->diff_path_counter = 0;
4637
4638        if (options->flags.follow_renames && options->pathspec.nr != 1)
4639                die(_("--follow requires exactly one pathspec"));
4640
4641        if (!options->use_color || external_diff())
4642                options->color_moved = 0;
4643
4644        FREE_AND_NULL(options->parseopts);
4645}
4646
4647static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4648{
4649        char c, *eq;
4650        int len;
4651
4652        if (*arg != '-')
4653                return 0;
4654        c = *++arg;
4655        if (!c)
4656                return 0;
4657        if (c == arg_short) {
4658                c = *++arg;
4659                if (!c)
4660                        return 1;
4661                if (val && isdigit(c)) {
4662                        char *end;
4663                        int n = strtoul(arg, &end, 10);
4664                        if (*end)
4665                                return 0;
4666                        *val = n;
4667                        return 1;
4668                }
4669                return 0;
4670        }
4671        if (c != '-')
4672                return 0;
4673        arg++;
4674        eq = strchrnul(arg, '=');
4675        len = eq - arg;
4676        if (!len || strncmp(arg, arg_long, len))
4677                return 0;
4678        if (*eq) {
4679                int n;
4680                char *end;
4681                if (!isdigit(*++eq))
4682                        return 0;
4683                n = strtoul(eq, &end, 10);
4684                if (*end)
4685                        return 0;
4686                *val = n;
4687        }
4688        return 1;
4689}
4690
4691static int diff_scoreopt_parse(const char *opt);
4692
4693static inline int short_opt(char opt, const char **argv,
4694                            const char **optarg)
4695{
4696        const char *arg = argv[0];
4697        if (arg[0] != '-' || arg[1] != opt)
4698                return 0;
4699        if (arg[2] != '\0') {
4700                *optarg = arg + 2;
4701                return 1;
4702        }
4703        if (!argv[1])
4704                die("Option '%c' requires a value", opt);
4705        *optarg = argv[1];
4706        return 2;
4707}
4708
4709int parse_long_opt(const char *opt, const char **argv,
4710                   const char **optarg)
4711{
4712        const char *arg = argv[0];
4713        if (!skip_prefix(arg, "--", &arg))
4714                return 0;
4715        if (!skip_prefix(arg, opt, &arg))
4716                return 0;
4717        if (*arg == '=') { /* stuck form: --option=value */
4718                *optarg = arg + 1;
4719                return 1;
4720        }
4721        if (*arg != '\0')
4722                return 0;
4723        /* separate form: --option value */
4724        if (!argv[1])
4725                die("Option '--%s' requires a value", opt);
4726        *optarg = argv[1];
4727        return 2;
4728}
4729
4730static int stat_opt(struct diff_options *options, const char **av)
4731{
4732        const char *arg = av[0];
4733        char *end;
4734        int width = options->stat_width;
4735        int name_width = options->stat_name_width;
4736        int graph_width = options->stat_graph_width;
4737        int count = options->stat_count;
4738        int argcount = 1;
4739
4740        if (!skip_prefix(arg, "--stat", &arg))
4741                BUG("stat option does not begin with --stat: %s", arg);
4742        end = (char *)arg;
4743
4744        switch (*arg) {
4745        case '-':
4746                if (skip_prefix(arg, "-width", &arg)) {
4747                        if (*arg == '=')
4748                                width = strtoul(arg + 1, &end, 10);
4749                        else if (!*arg && !av[1])
4750                                die_want_option("--stat-width");
4751                        else if (!*arg) {
4752                                width = strtoul(av[1], &end, 10);
4753                                argcount = 2;
4754                        }
4755                } else if (skip_prefix(arg, "-name-width", &arg)) {
4756                        if (*arg == '=')
4757                                name_width = strtoul(arg + 1, &end, 10);
4758                        else if (!*arg && !av[1])
4759                                die_want_option("--stat-name-width");
4760                        else if (!*arg) {
4761                                name_width = strtoul(av[1], &end, 10);
4762                                argcount = 2;
4763                        }
4764                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4765                        if (*arg == '=')
4766                                graph_width = strtoul(arg + 1, &end, 10);
4767                        else if (!*arg && !av[1])
4768                                die_want_option("--stat-graph-width");
4769                        else if (!*arg) {
4770                                graph_width = strtoul(av[1], &end, 10);
4771                                argcount = 2;
4772                        }
4773                } else if (skip_prefix(arg, "-count", &arg)) {
4774                        if (*arg == '=')
4775                                count = strtoul(arg + 1, &end, 10);
4776                        else if (!*arg && !av[1])
4777                                die_want_option("--stat-count");
4778                        else if (!*arg) {
4779                                count = strtoul(av[1], &end, 10);
4780                                argcount = 2;
4781                        }
4782                }
4783                break;
4784        case '=':
4785                width = strtoul(arg+1, &end, 10);
4786                if (*end == ',')
4787                        name_width = strtoul(end+1, &end, 10);
4788                if (*end == ',')
4789                        count = strtoul(end+1, &end, 10);
4790        }
4791
4792        /* Important! This checks all the error cases! */
4793        if (*end)
4794                return 0;
4795        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4796        options->stat_name_width = name_width;
4797        options->stat_graph_width = graph_width;
4798        options->stat_width = width;
4799        options->stat_count = count;
4800        return argcount;
4801}
4802
4803static int parse_dirstat_opt(struct diff_options *options, const char *params)
4804{
4805        struct strbuf errmsg = STRBUF_INIT;
4806        if (parse_dirstat_params(options, params, &errmsg))
4807                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4808                    errmsg.buf);
4809        strbuf_release(&errmsg);
4810        /*
4811         * The caller knows a dirstat-related option is given from the command
4812         * line; allow it to say "return this_function();"
4813         */
4814        options->output_format |= DIFF_FORMAT_DIRSTAT;
4815        return 1;
4816}
4817
4818static int parse_submodule_opt(struct diff_options *options, const char *value)
4819{
4820        if (parse_submodule_params(options, value))
4821                die(_("Failed to parse --submodule option parameter: '%s'"),
4822                        value);
4823        return 1;
4824}
4825
4826static const char diff_status_letters[] = {
4827        DIFF_STATUS_ADDED,
4828        DIFF_STATUS_COPIED,
4829        DIFF_STATUS_DELETED,
4830        DIFF_STATUS_MODIFIED,
4831        DIFF_STATUS_RENAMED,
4832        DIFF_STATUS_TYPE_CHANGED,
4833        DIFF_STATUS_UNKNOWN,
4834        DIFF_STATUS_UNMERGED,
4835        DIFF_STATUS_FILTER_AON,
4836        DIFF_STATUS_FILTER_BROKEN,
4837        '\0',
4838};
4839
4840static unsigned int filter_bit['Z' + 1];
4841
4842static void prepare_filter_bits(void)
4843{
4844        int i;
4845
4846        if (!filter_bit[DIFF_STATUS_ADDED]) {
4847                for (i = 0; diff_status_letters[i]; i++)
4848                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4849        }
4850}
4851
4852static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4853{
4854        return opt->filter & filter_bit[(int) status];
4855}
4856
4857static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4858{
4859        int i, optch;
4860
4861        prepare_filter_bits();
4862
4863        /*
4864         * If there is a negation e.g. 'd' in the input, and we haven't
4865         * initialized the filter field with another --diff-filter, start
4866         * from full set of bits, except for AON.
4867         */
4868        if (!opt->filter) {
4869                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4870                        if (optch < 'a' || 'z' < optch)
4871                                continue;
4872                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4873                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4874                        break;
4875                }
4876        }
4877
4878        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4879                unsigned int bit;
4880                int negate;
4881
4882                if ('a' <= optch && optch <= 'z') {
4883                        negate = 1;
4884                        optch = toupper(optch);
4885                } else {
4886                        negate = 0;
4887                }
4888
4889                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4890                if (!bit)
4891                        return optarg[i];
4892                if (negate)
4893                        opt->filter &= ~bit;
4894                else
4895                        opt->filter |= bit;
4896        }
4897        return 0;
4898}
4899
4900static void enable_patch_output(int *fmt)
4901{
4902        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4903        *fmt |= DIFF_FORMAT_PATCH;
4904}
4905
4906static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4907{
4908        int val = parse_ws_error_highlight(arg);
4909
4910        if (val < 0) {
4911                error("unknown value after ws-error-highlight=%.*s",
4912                      -1 - val, arg);
4913                return 0;
4914        }
4915        opt->ws_error_highlight = val;
4916        return 1;
4917}
4918
4919static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4920{
4921        struct object_id oid;
4922
4923        if (get_oid(arg, &oid))
4924                return error("unable to resolve '%s'", arg);
4925
4926        if (!opt->objfind)
4927                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4928
4929        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4930        opt->flags.recursive = 1;
4931        opt->flags.tree_in_recursive = 1;
4932        oidset_insert(opt->objfind, &oid);
4933        return 1;
4934}
4935
4936static int diff_opt_unified(const struct option *opt,
4937                            const char *arg, int unset)
4938{
4939        struct diff_options *options = opt->value;
4940        char *s;
4941
4942        BUG_ON_OPT_NEG(unset);
4943
4944        options->context = strtol(arg, &s, 10);
4945        if (*s)
4946                return error(_("%s expects a numerical value"), "--unified");
4947        enable_patch_output(&options->output_format);
4948
4949        return 0;
4950}
4951
4952static void prep_parse_options(struct diff_options *options)
4953{
4954        struct option parseopts[] = {
4955                OPT_GROUP(N_("Diff output format options")),
4956                OPT_BITOP('p', "patch", &options->output_format,
4957                          N_("generate patch"),
4958                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
4959                OPT_BITOP('u', NULL, &options->output_format,
4960                          N_("generate patch"),
4961                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
4962                OPT_CALLBACK_F('U', "unified", options, N_("<n>"),
4963                               N_("generate diffs with <n> lines context"),
4964                               PARSE_OPT_NONEG, diff_opt_unified),
4965                OPT_BOOL('W', "function-context", &options->flags.funccontext,
4966                         N_("generate diffs with <n> lines context")),
4967                OPT_BIT_F(0, "raw", &options->output_format,
4968                          N_("generate the diff in raw format"),
4969                          DIFF_FORMAT_RAW, PARSE_OPT_NONEG),
4970                OPT_END()
4971        };
4972
4973        ALLOC_ARRAY(options->parseopts, ARRAY_SIZE(parseopts));
4974        memcpy(options->parseopts, parseopts, sizeof(parseopts));
4975}
4976
4977int diff_opt_parse(struct diff_options *options,
4978                   const char **av, int ac, const char *prefix)
4979{
4980        const char *arg = av[0];
4981        const char *optarg;
4982        int argcount;
4983
4984        if (!prefix)
4985                prefix = "";
4986
4987        ac = parse_options(ac, av, prefix, options->parseopts, NULL,
4988                           PARSE_OPT_KEEP_DASHDASH |
4989                           PARSE_OPT_KEEP_UNKNOWN |
4990                           PARSE_OPT_NO_INTERNAL_HELP |
4991                           PARSE_OPT_ONE_SHOT |
4992                           PARSE_OPT_STOP_AT_NON_OPTION);
4993
4994        if (ac)
4995                return ac;
4996
4997        /* Output format options */
4998        if (!strcmp(arg, "--patch-with-raw")) {
4999                enable_patch_output(&options->output_format);
5000                options->output_format |= DIFF_FORMAT_RAW;
5001        } else if (!strcmp(arg, "--numstat"))
5002                options->output_format |= DIFF_FORMAT_NUMSTAT;
5003        else if (!strcmp(arg, "--shortstat"))
5004                options->output_format |= DIFF_FORMAT_SHORTSTAT;
5005        else if (skip_prefix(arg, "-X", &arg) ||
5006                 skip_to_optional_arg(arg, "--dirstat", &arg))
5007                return parse_dirstat_opt(options, arg);
5008        else if (!strcmp(arg, "--cumulative"))
5009                return parse_dirstat_opt(options, "cumulative");
5010        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
5011                parse_dirstat_opt(options, "files");
5012                return parse_dirstat_opt(options, arg);
5013        }
5014        else if (!strcmp(arg, "--check"))
5015                options->output_format |= DIFF_FORMAT_CHECKDIFF;
5016        else if (!strcmp(arg, "--summary"))
5017                options->output_format |= DIFF_FORMAT_SUMMARY;
5018        else if (!strcmp(arg, "--patch-with-stat")) {
5019                enable_patch_output(&options->output_format);
5020                options->output_format |= DIFF_FORMAT_DIFFSTAT;
5021        } else if (!strcmp(arg, "--name-only"))
5022                options->output_format |= DIFF_FORMAT_NAME;
5023        else if (!strcmp(arg, "--name-status"))
5024                options->output_format |= DIFF_FORMAT_NAME_STATUS;
5025        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
5026                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
5027        else if (starts_with(arg, "--stat"))
5028                /* --stat, --stat-width, --stat-name-width, or --stat-count */
5029                return stat_opt(options, av);
5030        else if (!strcmp(arg, "--compact-summary")) {
5031                 options->flags.stat_with_summary = 1;
5032                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
5033        } else if (!strcmp(arg, "--no-compact-summary"))
5034                 options->flags.stat_with_summary = 0;
5035        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
5036                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
5037        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
5038                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
5039        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
5040                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
5041
5042        /* renames options */
5043        else if (starts_with(arg, "-B") ||
5044                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
5045                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
5046                        return error("invalid argument to -B: %s", arg+2);
5047        }
5048        else if (starts_with(arg, "-M") ||
5049                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
5050                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
5051                        return error("invalid argument to -M: %s", arg+2);
5052                options->detect_rename = DIFF_DETECT_RENAME;
5053        }
5054        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
5055                options->irreversible_delete = 1;
5056        }
5057        else if (starts_with(arg, "-C") ||
5058                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
5059                if (options->detect_rename == DIFF_DETECT_COPY)
5060                        options->flags.find_copies_harder = 1;
5061                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
5062                        return error("invalid argument to -C: %s", arg+2);
5063                options->detect_rename = DIFF_DETECT_COPY;
5064        }
5065        else if (!strcmp(arg, "--no-renames"))
5066                options->detect_rename = 0;
5067        else if (!strcmp(arg, "--rename-empty"))
5068                options->flags.rename_empty = 1;
5069        else if (!strcmp(arg, "--no-rename-empty"))
5070                options->flags.rename_empty = 0;
5071        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
5072                options->flags.relative_name = 1;
5073                if (arg)
5074                        options->prefix = arg;
5075        }
5076
5077        /* xdiff options */
5078        else if (!strcmp(arg, "--minimal"))
5079                DIFF_XDL_SET(options, NEED_MINIMAL);
5080        else if (!strcmp(arg, "--no-minimal"))
5081                DIFF_XDL_CLR(options, NEED_MINIMAL);
5082        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
5083                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
5084        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
5085                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
5086        else if (!strcmp(arg, "--ignore-space-at-eol"))
5087                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
5088        else if (!strcmp(arg, "--ignore-cr-at-eol"))
5089                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
5090        else if (!strcmp(arg, "--ignore-blank-lines"))
5091                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
5092        else if (!strcmp(arg, "--indent-heuristic"))
5093                DIFF_XDL_SET(options, INDENT_HEURISTIC);
5094        else if (!strcmp(arg, "--no-indent-heuristic"))
5095                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
5096        else if (!strcmp(arg, "--patience")) {
5097                int i;
5098                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5099                /*
5100                 * Both --patience and --anchored use PATIENCE_DIFF
5101                 * internally, so remove any anchors previously
5102                 * specified.
5103                 */
5104                for (i = 0; i < options->anchors_nr; i++)
5105                        free(options->anchors[i]);
5106                options->anchors_nr = 0;
5107        } else if (!strcmp(arg, "--histogram"))
5108                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
5109        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
5110                long value = parse_algorithm_value(optarg);
5111                if (value < 0)
5112                        return error("option diff-algorithm accepts \"myers\", "
5113                                     "\"minimal\", \"patience\" and \"histogram\"");
5114                /* clear out previous settings */
5115                DIFF_XDL_CLR(options, NEED_MINIMAL);
5116                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
5117                options->xdl_opts |= value;
5118                return argcount;
5119        } else if (skip_prefix(arg, "--anchored=", &arg)) {
5120                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5121                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
5122                           options->anchors_alloc);
5123                options->anchors[options->anchors_nr++] = xstrdup(arg);
5124        }
5125
5126        /* flags options */
5127        else if (!strcmp(arg, "--binary")) {
5128                enable_patch_output(&options->output_format);
5129                options->flags.binary = 1;
5130        }
5131        else if (!strcmp(arg, "--full-index"))
5132                options->flags.full_index = 1;
5133        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
5134                options->flags.text = 1;
5135        else if (!strcmp(arg, "-R"))
5136                options->flags.reverse_diff = 1;
5137        else if (!strcmp(arg, "--find-copies-harder"))
5138                options->flags.find_copies_harder = 1;
5139        else if (!strcmp(arg, "--follow"))
5140                options->flags.follow_renames = 1;
5141        else if (!strcmp(arg, "--no-follow")) {
5142                options->flags.follow_renames = 0;
5143                options->flags.default_follow_renames = 0;
5144        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5145                int value = git_config_colorbool(NULL, arg);
5146                if (value < 0)
5147                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5148                options->use_color = value;
5149        }
5150        else if (!strcmp(arg, "--no-color"))
5151                options->use_color = 0;
5152        else if (!strcmp(arg, "--color-moved")) {
5153                if (diff_color_moved_default)
5154                        options->color_moved = diff_color_moved_default;
5155                if (options->color_moved == COLOR_MOVED_NO)
5156                        options->color_moved = COLOR_MOVED_DEFAULT;
5157        } else if (!strcmp(arg, "--no-color-moved"))
5158                options->color_moved = COLOR_MOVED_NO;
5159        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5160                int cm = parse_color_moved(arg);
5161                if (cm < 0)
5162                        return error("bad --color-moved argument: %s", arg);
5163                options->color_moved = cm;
5164        } else if (!strcmp(arg, "--no-color-moved-ws")) {
5165                options->color_moved_ws_handling = 0;
5166        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5167                unsigned cm = parse_color_moved_ws(arg);
5168                if (cm & COLOR_MOVED_WS_ERROR)
5169                        return -1;
5170                options->color_moved_ws_handling = cm;
5171        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5172                options->use_color = 1;
5173                options->word_diff = DIFF_WORDS_COLOR;
5174        }
5175        else if (!strcmp(arg, "--word-diff")) {
5176                if (options->word_diff == DIFF_WORDS_NONE)
5177                        options->word_diff = DIFF_WORDS_PLAIN;
5178        }
5179        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5180                if (!strcmp(arg, "plain"))
5181                        options->word_diff = DIFF_WORDS_PLAIN;
5182                else if (!strcmp(arg, "color")) {
5183                        options->use_color = 1;
5184                        options->word_diff = DIFF_WORDS_COLOR;
5185                }
5186                else if (!strcmp(arg, "porcelain"))
5187                        options->word_diff = DIFF_WORDS_PORCELAIN;
5188                else if (!strcmp(arg, "none"))
5189                        options->word_diff = DIFF_WORDS_NONE;
5190                else
5191                        die("bad --word-diff argument: %s", arg);
5192        }
5193        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5194                if (options->word_diff == DIFF_WORDS_NONE)
5195                        options->word_diff = DIFF_WORDS_PLAIN;
5196                options->word_regex = optarg;
5197                return argcount;
5198        }
5199        else if (!strcmp(arg, "--exit-code"))
5200                options->flags.exit_with_status = 1;
5201        else if (!strcmp(arg, "--quiet"))
5202                options->flags.quick = 1;
5203        else if (!strcmp(arg, "--ext-diff"))
5204                options->flags.allow_external = 1;
5205        else if (!strcmp(arg, "--no-ext-diff"))
5206                options->flags.allow_external = 0;
5207        else if (!strcmp(arg, "--textconv")) {
5208                options->flags.allow_textconv = 1;
5209                options->flags.textconv_set_via_cmdline = 1;
5210        } else if (!strcmp(arg, "--no-textconv"))
5211                options->flags.allow_textconv = 0;
5212        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5213                options->flags.override_submodule_config = 1;
5214                handle_ignore_submodules_arg(options, arg);
5215        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5216                return parse_submodule_opt(options, arg);
5217        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5218                return parse_ws_error_highlight_opt(options, arg);
5219        else if (!strcmp(arg, "--ita-invisible-in-index"))
5220                options->ita_invisible_in_index = 1;
5221        else if (!strcmp(arg, "--ita-visible-in-index"))
5222                options->ita_invisible_in_index = 0;
5223
5224        /* misc options */
5225        else if (!strcmp(arg, "-z"))
5226                options->line_termination = 0;
5227        else if ((argcount = short_opt('l', av, &optarg))) {
5228                options->rename_limit = strtoul(optarg, NULL, 10);
5229                return argcount;
5230        }
5231        else if ((argcount = short_opt('S', av, &optarg))) {
5232                options->pickaxe = optarg;
5233                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5234                return argcount;
5235        } else if ((argcount = short_opt('G', av, &optarg))) {
5236                options->pickaxe = optarg;
5237                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5238                return argcount;
5239        }
5240        else if (!strcmp(arg, "--pickaxe-all"))
5241                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5242        else if (!strcmp(arg, "--pickaxe-regex"))
5243                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5244        else if ((argcount = short_opt('O', av, &optarg))) {
5245                options->orderfile = prefix_filename(prefix, optarg);
5246                return argcount;
5247        } else if (skip_prefix(arg, "--find-object=", &arg))
5248                return parse_objfind_opt(options, arg);
5249        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5250                int offending = parse_diff_filter_opt(optarg, options);
5251                if (offending)
5252                        die("unknown change class '%c' in --diff-filter=%s",
5253                            offending, optarg);
5254                return argcount;
5255        }
5256        else if (!strcmp(arg, "--no-abbrev"))
5257                options->abbrev = 0;
5258        else if (!strcmp(arg, "--abbrev"))
5259                options->abbrev = DEFAULT_ABBREV;
5260        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5261                options->abbrev = strtoul(arg, NULL, 10);
5262                if (options->abbrev < MINIMUM_ABBREV)
5263                        options->abbrev = MINIMUM_ABBREV;
5264                else if (the_hash_algo->hexsz < options->abbrev)
5265                        options->abbrev = the_hash_algo->hexsz;
5266        }
5267        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5268                options->a_prefix = optarg;
5269                return argcount;
5270        }
5271        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5272                options->line_prefix = optarg;
5273                options->line_prefix_length = strlen(options->line_prefix);
5274                graph_setup_line_prefix(options);
5275                return argcount;
5276        }
5277        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5278                options->b_prefix = optarg;
5279                return argcount;
5280        }
5281        else if (!strcmp(arg, "--no-prefix"))
5282                options->a_prefix = options->b_prefix = "";
5283        else if (opt_arg(arg, '\0', "inter-hunk-context",
5284                         &options->interhunkcontext))
5285                ;
5286        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5287                char *path = prefix_filename(prefix, optarg);
5288                options->file = xfopen(path, "w");
5289                options->close_file = 1;
5290                if (options->use_color != GIT_COLOR_ALWAYS)
5291                        options->use_color = GIT_COLOR_NEVER;
5292                free(path);
5293                return argcount;
5294        } else
5295                return 0;
5296        return 1;
5297}
5298
5299int parse_rename_score(const char **cp_p)
5300{
5301        unsigned long num, scale;
5302        int ch, dot;
5303        const char *cp = *cp_p;
5304
5305        num = 0;
5306        scale = 1;
5307        dot = 0;
5308        for (;;) {
5309                ch = *cp;
5310                if ( !dot && ch == '.' ) {
5311                        scale = 1;
5312                        dot = 1;
5313                } else if ( ch == '%' ) {
5314                        scale = dot ? scale*100 : 100;
5315                        cp++;   /* % is always at the end */
5316                        break;
5317                } else if ( ch >= '0' && ch <= '9' ) {
5318                        if ( scale < 100000 ) {
5319                                scale *= 10;
5320                                num = (num*10) + (ch-'0');
5321                        }
5322                } else {
5323                        break;
5324                }
5325                cp++;
5326        }
5327        *cp_p = cp;
5328
5329        /* user says num divided by scale and we say internally that
5330         * is MAX_SCORE * num / scale.
5331         */
5332        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5333}
5334
5335static int diff_scoreopt_parse(const char *opt)
5336{
5337        int opt1, opt2, cmd;
5338
5339        if (*opt++ != '-')
5340                return -1;
5341        cmd = *opt++;
5342        if (cmd == '-') {
5343                /* convert the long-form arguments into short-form versions */
5344                if (skip_prefix(opt, "break-rewrites", &opt)) {
5345                        if (*opt == 0 || *opt++ == '=')
5346                                cmd = 'B';
5347                } else if (skip_prefix(opt, "find-copies", &opt)) {
5348                        if (*opt == 0 || *opt++ == '=')
5349                                cmd = 'C';
5350                } else if (skip_prefix(opt, "find-renames", &opt)) {
5351                        if (*opt == 0 || *opt++ == '=')
5352                                cmd = 'M';
5353                }
5354        }
5355        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5356                return -1; /* that is not a -M, -C, or -B option */
5357
5358        opt1 = parse_rename_score(&opt);
5359        if (cmd != 'B')
5360                opt2 = 0;
5361        else {
5362                if (*opt == 0)
5363                        opt2 = 0;
5364                else if (*opt != '/')
5365                        return -1; /* we expect -B80/99 or -B80 */
5366                else {
5367                        opt++;
5368                        opt2 = parse_rename_score(&opt);
5369                }
5370        }
5371        if (*opt != 0)
5372                return -1;
5373        return opt1 | (opt2 << 16);
5374}
5375
5376struct diff_queue_struct diff_queued_diff;
5377
5378void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5379{
5380        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5381        queue->queue[queue->nr++] = dp;
5382}
5383
5384struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5385                                 struct diff_filespec *one,
5386                                 struct diff_filespec *two)
5387{
5388        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5389        dp->one = one;
5390        dp->two = two;
5391        if (queue)
5392                diff_q(queue, dp);
5393        return dp;
5394}
5395
5396void diff_free_filepair(struct diff_filepair *p)
5397{
5398        free_filespec(p->one);
5399        free_filespec(p->two);
5400        free(p);
5401}
5402
5403const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5404{
5405        int abblen;
5406        const char *abbrev;
5407
5408        /* Do we want all 40 hex characters? */
5409        if (len == the_hash_algo->hexsz)
5410                return oid_to_hex(oid);
5411
5412        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5413        abbrev = diff_abbrev_oid(oid, len);
5414
5415        if (!print_sha1_ellipsis())
5416                return abbrev;
5417
5418        abblen = strlen(abbrev);
5419
5420        /*
5421         * In well-behaved cases, where the abbreviated result is the
5422         * same as the requested length, append three dots after the
5423         * abbreviation (hence the whole logic is limited to the case
5424         * where abblen < 37); when the actual abbreviated result is a
5425         * bit longer than the requested length, we reduce the number
5426         * of dots so that they match the well-behaved ones.  However,
5427         * if the actual abbreviation is longer than the requested
5428         * length by more than three, we give up on aligning, and add
5429         * three dots anyway, to indicate that the output is not the
5430         * full object name.  Yes, this may be suboptimal, but this
5431         * appears only in "diff --raw --abbrev" output and it is not
5432         * worth the effort to change it now.  Note that this would
5433         * likely to work fine when the automatic sizing of default
5434         * abbreviation length is used--we would be fed -1 in "len" in
5435         * that case, and will end up always appending three-dots, but
5436         * the automatic sizing is supposed to give abblen that ensures
5437         * uniqueness across all objects (statistically speaking).
5438         */
5439        if (abblen < the_hash_algo->hexsz - 3) {
5440                static char hex[GIT_MAX_HEXSZ + 1];
5441                if (len < abblen && abblen <= len + 2)
5442                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5443                else
5444                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5445                return hex;
5446        }
5447
5448        return oid_to_hex(oid);
5449}
5450
5451static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5452{
5453        int line_termination = opt->line_termination;
5454        int inter_name_termination = line_termination ? '\t' : '\0';
5455
5456        fprintf(opt->file, "%s", diff_line_prefix(opt));
5457        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5458                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5459                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5460                fprintf(opt->file, "%s ",
5461                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5462        }
5463        if (p->score) {
5464                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5465                        inter_name_termination);
5466        } else {
5467                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5468        }
5469
5470        if (p->status == DIFF_STATUS_COPIED ||
5471            p->status == DIFF_STATUS_RENAMED) {
5472                const char *name_a, *name_b;
5473                name_a = p->one->path;
5474                name_b = p->two->path;
5475                strip_prefix(opt->prefix_length, &name_a, &name_b);
5476                write_name_quoted(name_a, opt->file, inter_name_termination);
5477                write_name_quoted(name_b, opt->file, line_termination);
5478        } else {
5479                const char *name_a, *name_b;
5480                name_a = p->one->mode ? p->one->path : p->two->path;
5481                name_b = NULL;
5482                strip_prefix(opt->prefix_length, &name_a, &name_b);
5483                write_name_quoted(name_a, opt->file, line_termination);
5484        }
5485}
5486
5487int diff_unmodified_pair(struct diff_filepair *p)
5488{
5489        /* This function is written stricter than necessary to support
5490         * the currently implemented transformers, but the idea is to
5491         * let transformers to produce diff_filepairs any way they want,
5492         * and filter and clean them up here before producing the output.
5493         */
5494        struct diff_filespec *one = p->one, *two = p->two;
5495
5496        if (DIFF_PAIR_UNMERGED(p))
5497                return 0; /* unmerged is interesting */
5498
5499        /* deletion, addition, mode or type change
5500         * and rename are all interesting.
5501         */
5502        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5503            DIFF_PAIR_MODE_CHANGED(p) ||
5504            strcmp(one->path, two->path))
5505                return 0;
5506
5507        /* both are valid and point at the same path.  that is, we are
5508         * dealing with a change.
5509         */
5510        if (one->oid_valid && two->oid_valid &&
5511            oideq(&one->oid, &two->oid) &&
5512            !one->dirty_submodule && !two->dirty_submodule)
5513                return 1; /* no change */
5514        if (!one->oid_valid && !two->oid_valid)
5515                return 1; /* both look at the same file on the filesystem. */
5516        return 0;
5517}
5518
5519static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5520{
5521        if (diff_unmodified_pair(p))
5522                return;
5523
5524        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5525            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5526                return; /* no tree diffs in patch format */
5527
5528        run_diff(p, o);
5529}
5530
5531static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5532                            struct diffstat_t *diffstat)
5533{
5534        if (diff_unmodified_pair(p))
5535                return;
5536
5537        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5538            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5539                return; /* no useful stat for tree diffs */
5540
5541        run_diffstat(p, o, diffstat);
5542}
5543
5544static void diff_flush_checkdiff(struct diff_filepair *p,
5545                struct diff_options *o)
5546{
5547        if (diff_unmodified_pair(p))
5548                return;
5549
5550        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5551            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5552                return; /* nothing to check in tree diffs */
5553
5554        run_checkdiff(p, o);
5555}
5556
5557int diff_queue_is_empty(void)
5558{
5559        struct diff_queue_struct *q = &diff_queued_diff;
5560        int i;
5561        for (i = 0; i < q->nr; i++)
5562                if (!diff_unmodified_pair(q->queue[i]))
5563                        return 0;
5564        return 1;
5565}
5566
5567#if DIFF_DEBUG
5568void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5569{
5570        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5571                x, one ? one : "",
5572                s->path,
5573                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5574                s->mode,
5575                s->oid_valid ? oid_to_hex(&s->oid) : "");
5576        fprintf(stderr, "queue[%d] %s size %lu\n",
5577                x, one ? one : "",
5578                s->size);
5579}
5580
5581void diff_debug_filepair(const struct diff_filepair *p, int i)
5582{
5583        diff_debug_filespec(p->one, i, "one");
5584        diff_debug_filespec(p->two, i, "two");
5585        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5586                p->score, p->status ? p->status : '?',
5587                p->one->rename_used, p->broken_pair);
5588}
5589
5590void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5591{
5592        int i;
5593        if (msg)
5594                fprintf(stderr, "%s\n", msg);
5595        fprintf(stderr, "q->nr = %d\n", q->nr);
5596        for (i = 0; i < q->nr; i++) {
5597                struct diff_filepair *p = q->queue[i];
5598                diff_debug_filepair(p, i);
5599        }
5600}
5601#endif
5602
5603static void diff_resolve_rename_copy(void)
5604{
5605        int i;
5606        struct diff_filepair *p;
5607        struct diff_queue_struct *q = &diff_queued_diff;
5608
5609        diff_debug_queue("resolve-rename-copy", q);
5610
5611        for (i = 0; i < q->nr; i++) {
5612                p = q->queue[i];
5613                p->status = 0; /* undecided */
5614                if (DIFF_PAIR_UNMERGED(p))
5615                        p->status = DIFF_STATUS_UNMERGED;
5616                else if (!DIFF_FILE_VALID(p->one))
5617                        p->status = DIFF_STATUS_ADDED;
5618                else if (!DIFF_FILE_VALID(p->two))
5619                        p->status = DIFF_STATUS_DELETED;
5620                else if (DIFF_PAIR_TYPE_CHANGED(p))
5621                        p->status = DIFF_STATUS_TYPE_CHANGED;
5622
5623                /* from this point on, we are dealing with a pair
5624                 * whose both sides are valid and of the same type, i.e.
5625                 * either in-place edit or rename/copy edit.
5626                 */
5627                else if (DIFF_PAIR_RENAME(p)) {
5628                        /*
5629                         * A rename might have re-connected a broken
5630                         * pair up, causing the pathnames to be the
5631                         * same again. If so, that's not a rename at
5632                         * all, just a modification..
5633                         *
5634                         * Otherwise, see if this source was used for
5635                         * multiple renames, in which case we decrement
5636                         * the count, and call it a copy.
5637                         */
5638                        if (!strcmp(p->one->path, p->two->path))
5639                                p->status = DIFF_STATUS_MODIFIED;
5640                        else if (--p->one->rename_used > 0)
5641                                p->status = DIFF_STATUS_COPIED;
5642                        else
5643                                p->status = DIFF_STATUS_RENAMED;
5644                }
5645                else if (!oideq(&p->one->oid, &p->two->oid) ||
5646                         p->one->mode != p->two->mode ||
5647                         p->one->dirty_submodule ||
5648                         p->two->dirty_submodule ||
5649                         is_null_oid(&p->one->oid))
5650                        p->status = DIFF_STATUS_MODIFIED;
5651                else {
5652                        /* This is a "no-change" entry and should not
5653                         * happen anymore, but prepare for broken callers.
5654                         */
5655                        error("feeding unmodified %s to diffcore",
5656                              p->one->path);
5657                        p->status = DIFF_STATUS_UNKNOWN;
5658                }
5659        }
5660        diff_debug_queue("resolve-rename-copy done", q);
5661}
5662
5663static int check_pair_status(struct diff_filepair *p)
5664{
5665        switch (p->status) {
5666        case DIFF_STATUS_UNKNOWN:
5667                return 0;
5668        case 0:
5669                die("internal error in diff-resolve-rename-copy");
5670        default:
5671                return 1;
5672        }
5673}
5674
5675static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5676{
5677        int fmt = opt->output_format;
5678
5679        if (fmt & DIFF_FORMAT_CHECKDIFF)
5680                diff_flush_checkdiff(p, opt);
5681        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5682                diff_flush_raw(p, opt);
5683        else if (fmt & DIFF_FORMAT_NAME) {
5684                const char *name_a, *name_b;
5685                name_a = p->two->path;
5686                name_b = NULL;
5687                strip_prefix(opt->prefix_length, &name_a, &name_b);
5688                fprintf(opt->file, "%s", diff_line_prefix(opt));
5689                write_name_quoted(name_a, opt->file, opt->line_termination);
5690        }
5691}
5692
5693static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5694{
5695        struct strbuf sb = STRBUF_INIT;
5696        if (fs->mode)
5697                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5698        else
5699                strbuf_addf(&sb, " %s ", newdelete);
5700
5701        quote_c_style(fs->path, &sb, NULL, 0);
5702        strbuf_addch(&sb, '\n');
5703        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5704                         sb.buf, sb.len, 0);
5705        strbuf_release(&sb);
5706}
5707
5708static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5709                int show_name)
5710{
5711        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5712                struct strbuf sb = STRBUF_INIT;
5713                strbuf_addf(&sb, " mode change %06o => %06o",
5714                            p->one->mode, p->two->mode);
5715                if (show_name) {
5716                        strbuf_addch(&sb, ' ');
5717                        quote_c_style(p->two->path, &sb, NULL, 0);
5718                }
5719                strbuf_addch(&sb, '\n');
5720                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5721                                 sb.buf, sb.len, 0);
5722                strbuf_release(&sb);
5723        }
5724}
5725
5726static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5727                struct diff_filepair *p)
5728{
5729        struct strbuf sb = STRBUF_INIT;
5730        struct strbuf names = STRBUF_INIT;
5731
5732        pprint_rename(&names, p->one->path, p->two->path);
5733        strbuf_addf(&sb, " %s %s (%d%%)\n",
5734                    renamecopy, names.buf, similarity_index(p));
5735        strbuf_release(&names);
5736        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5737                                 sb.buf, sb.len, 0);
5738        show_mode_change(opt, p, 0);
5739        strbuf_release(&sb);
5740}
5741
5742static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5743{
5744        switch(p->status) {
5745        case DIFF_STATUS_DELETED:
5746                show_file_mode_name(opt, "delete", p->one);
5747                break;
5748        case DIFF_STATUS_ADDED:
5749                show_file_mode_name(opt, "create", p->two);
5750                break;
5751        case DIFF_STATUS_COPIED:
5752                show_rename_copy(opt, "copy", p);
5753                break;
5754        case DIFF_STATUS_RENAMED:
5755                show_rename_copy(opt, "rename", p);
5756                break;
5757        default:
5758                if (p->score) {
5759                        struct strbuf sb = STRBUF_INIT;
5760                        strbuf_addstr(&sb, " rewrite ");
5761                        quote_c_style(p->two->path, &sb, NULL, 0);
5762                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5763                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5764                                         sb.buf, sb.len, 0);
5765                        strbuf_release(&sb);
5766                }
5767                show_mode_change(opt, p, !p->score);
5768                break;
5769        }
5770}
5771
5772struct patch_id_t {
5773        git_SHA_CTX *ctx;
5774        int patchlen;
5775};
5776
5777static int remove_space(char *line, int len)
5778{
5779        int i;
5780        char *dst = line;
5781        unsigned char c;
5782
5783        for (i = 0; i < len; i++)
5784                if (!isspace((c = line[i])))
5785                        *dst++ = c;
5786
5787        return dst - line;
5788}
5789
5790static void patch_id_consume(void *priv, char *line, unsigned long len)
5791{
5792        struct patch_id_t *data = priv;
5793        int new_len;
5794
5795        new_len = remove_space(line, len);
5796
5797        git_SHA1_Update(data->ctx, line, new_len);
5798        data->patchlen += new_len;
5799}
5800
5801static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5802{
5803        git_SHA1_Update(ctx, str, strlen(str));
5804}
5805
5806static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5807{
5808        /* large enough for 2^32 in octal */
5809        char buf[12];
5810        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5811        git_SHA1_Update(ctx, buf, len);
5812}
5813
5814/* returns 0 upon success, and writes result into sha1 */
5815static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5816{
5817        struct diff_queue_struct *q = &diff_queued_diff;
5818        int i;
5819        git_SHA_CTX ctx;
5820        struct patch_id_t data;
5821
5822        git_SHA1_Init(&ctx);
5823        memset(&data, 0, sizeof(struct patch_id_t));
5824        data.ctx = &ctx;
5825
5826        for (i = 0; i < q->nr; i++) {
5827                xpparam_t xpp;
5828                xdemitconf_t xecfg;
5829                mmfile_t mf1, mf2;
5830                struct diff_filepair *p = q->queue[i];
5831                int len1, len2;
5832
5833                memset(&xpp, 0, sizeof(xpp));
5834                memset(&xecfg, 0, sizeof(xecfg));
5835                if (p->status == 0)
5836                        return error("internal diff status error");
5837                if (p->status == DIFF_STATUS_UNKNOWN)
5838                        continue;
5839                if (diff_unmodified_pair(p))
5840                        continue;
5841                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5842                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5843                        continue;
5844                if (DIFF_PAIR_UNMERGED(p))
5845                        continue;
5846
5847                diff_fill_oid_info(p->one, options->repo->index);
5848                diff_fill_oid_info(p->two, options->repo->index);
5849
5850                len1 = remove_space(p->one->path, strlen(p->one->path));
5851                len2 = remove_space(p->two->path, strlen(p->two->path));
5852                patch_id_add_string(&ctx, "diff--git");
5853                patch_id_add_string(&ctx, "a/");
5854                git_SHA1_Update(&ctx, p->one->path, len1);
5855                patch_id_add_string(&ctx, "b/");
5856                git_SHA1_Update(&ctx, p->two->path, len2);
5857
5858                if (p->one->mode == 0) {
5859                        patch_id_add_string(&ctx, "newfilemode");
5860                        patch_id_add_mode(&ctx, p->two->mode);
5861                        patch_id_add_string(&ctx, "---/dev/null");
5862                        patch_id_add_string(&ctx, "+++b/");
5863                        git_SHA1_Update(&ctx, p->two->path, len2);
5864                } else if (p->two->mode == 0) {
5865                        patch_id_add_string(&ctx, "deletedfilemode");
5866                        patch_id_add_mode(&ctx, p->one->mode);
5867                        patch_id_add_string(&ctx, "---a/");
5868                        git_SHA1_Update(&ctx, p->one->path, len1);
5869                        patch_id_add_string(&ctx, "+++/dev/null");
5870                } else {
5871                        patch_id_add_string(&ctx, "---a/");
5872                        git_SHA1_Update(&ctx, p->one->path, len1);
5873                        patch_id_add_string(&ctx, "+++b/");
5874                        git_SHA1_Update(&ctx, p->two->path, len2);
5875                }
5876
5877                if (diff_header_only)
5878                        continue;
5879
5880                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5881                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5882                        return error("unable to read files to diff");
5883
5884                if (diff_filespec_is_binary(options->repo, p->one) ||
5885                    diff_filespec_is_binary(options->repo, p->two)) {
5886                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5887                                        GIT_SHA1_HEXSZ);
5888                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5889                                        GIT_SHA1_HEXSZ);
5890                        continue;
5891                }
5892
5893                xpp.flags = 0;
5894                xecfg.ctxlen = 3;
5895                xecfg.flags = 0;
5896                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
5897                                  patch_id_consume, &data, &xpp, &xecfg))
5898                        return error("unable to generate patch-id diff for %s",
5899                                     p->one->path);
5900        }
5901
5902        git_SHA1_Final(oid->hash, &ctx);
5903        return 0;
5904}
5905
5906int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5907{
5908        struct diff_queue_struct *q = &diff_queued_diff;
5909        int i;
5910        int result = diff_get_patch_id(options, oid, diff_header_only);
5911
5912        for (i = 0; i < q->nr; i++)
5913                diff_free_filepair(q->queue[i]);
5914
5915        free(q->queue);
5916        DIFF_QUEUE_CLEAR(q);
5917
5918        return result;
5919}
5920
5921static int is_summary_empty(const struct diff_queue_struct *q)
5922{
5923        int i;
5924
5925        for (i = 0; i < q->nr; i++) {
5926                const struct diff_filepair *p = q->queue[i];
5927
5928                switch (p->status) {
5929                case DIFF_STATUS_DELETED:
5930                case DIFF_STATUS_ADDED:
5931                case DIFF_STATUS_COPIED:
5932                case DIFF_STATUS_RENAMED:
5933                        return 0;
5934                default:
5935                        if (p->score)
5936                                return 0;
5937                        if (p->one->mode && p->two->mode &&
5938                            p->one->mode != p->two->mode)
5939                                return 0;
5940                        break;
5941                }
5942        }
5943        return 1;
5944}
5945
5946static const char rename_limit_warning[] =
5947N_("inexact rename detection was skipped due to too many files.");
5948
5949static const char degrade_cc_to_c_warning[] =
5950N_("only found copies from modified paths due to too many files.");
5951
5952static const char rename_limit_advice[] =
5953N_("you may want to set your %s variable to at least "
5954   "%d and retry the command.");
5955
5956void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5957{
5958        fflush(stdout);
5959        if (degraded_cc)
5960                warning(_(degrade_cc_to_c_warning));
5961        else if (needed)
5962                warning(_(rename_limit_warning));
5963        else
5964                return;
5965        if (0 < needed)
5966                warning(_(rename_limit_advice), varname, needed);
5967}
5968
5969static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5970{
5971        int i;
5972        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5973        struct diff_queue_struct *q = &diff_queued_diff;
5974
5975        if (WSEH_NEW & WS_RULE_MASK)
5976                BUG("WS rules bit mask overlaps with diff symbol flags");
5977
5978        if (o->color_moved)
5979                o->emitted_symbols = &esm;
5980
5981        for (i = 0; i < q->nr; i++) {
5982                struct diff_filepair *p = q->queue[i];
5983                if (check_pair_status(p))
5984                        diff_flush_patch(p, o);
5985        }
5986
5987        if (o->emitted_symbols) {
5988                if (o->color_moved) {
5989                        struct hashmap add_lines, del_lines;
5990
5991                        if (o->color_moved_ws_handling &
5992                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5993                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5994
5995                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5996                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5997
5998                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5999                        mark_color_as_moved(o, &add_lines, &del_lines);
6000                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
6001                                dim_moved_lines(o);
6002
6003                        hashmap_free(&add_lines, 1);
6004                        hashmap_free(&del_lines, 1);
6005                }
6006
6007                for (i = 0; i < esm.nr; i++)
6008                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
6009
6010                for (i = 0; i < esm.nr; i++)
6011                        free((void *)esm.buf[i].line);
6012                esm.nr = 0;
6013
6014                o->emitted_symbols = NULL;
6015        }
6016}
6017
6018void diff_flush(struct diff_options *options)
6019{
6020        struct diff_queue_struct *q = &diff_queued_diff;
6021        int i, output_format = options->output_format;
6022        int separator = 0;
6023        int dirstat_by_line = 0;
6024
6025        /*
6026         * Order: raw, stat, summary, patch
6027         * or:    name/name-status/checkdiff (other bits clear)
6028         */
6029        if (!q->nr)
6030                goto free_queue;
6031
6032        if (output_format & (DIFF_FORMAT_RAW |
6033                             DIFF_FORMAT_NAME |
6034                             DIFF_FORMAT_NAME_STATUS |
6035                             DIFF_FORMAT_CHECKDIFF)) {
6036                for (i = 0; i < q->nr; i++) {
6037                        struct diff_filepair *p = q->queue[i];
6038                        if (check_pair_status(p))
6039                                flush_one_pair(p, options);
6040                }
6041                separator++;
6042        }
6043
6044        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
6045                dirstat_by_line = 1;
6046
6047        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
6048            dirstat_by_line) {
6049                struct diffstat_t diffstat;
6050
6051                memset(&diffstat, 0, sizeof(struct diffstat_t));
6052                for (i = 0; i < q->nr; i++) {
6053                        struct diff_filepair *p = q->queue[i];
6054                        if (check_pair_status(p))
6055                                diff_flush_stat(p, options, &diffstat);
6056                }
6057                if (output_format & DIFF_FORMAT_NUMSTAT)
6058                        show_numstat(&diffstat, options);
6059                if (output_format & DIFF_FORMAT_DIFFSTAT)
6060                        show_stats(&diffstat, options);
6061                if (output_format & DIFF_FORMAT_SHORTSTAT)
6062                        show_shortstats(&diffstat, options);
6063                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
6064                        show_dirstat_by_line(&diffstat, options);
6065                free_diffstat_info(&diffstat);
6066                separator++;
6067        }
6068        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
6069                show_dirstat(options);
6070
6071        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
6072                for (i = 0; i < q->nr; i++) {
6073                        diff_summary(options, q->queue[i]);
6074                }
6075                separator++;
6076        }
6077
6078        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
6079            options->flags.exit_with_status &&
6080            options->flags.diff_from_contents) {
6081                /*
6082                 * run diff_flush_patch for the exit status. setting
6083                 * options->file to /dev/null should be safe, because we
6084                 * aren't supposed to produce any output anyway.
6085                 */
6086                if (options->close_file)
6087                        fclose(options->file);
6088                options->file = xfopen("/dev/null", "w");
6089                options->close_file = 1;
6090                options->color_moved = 0;
6091                for (i = 0; i < q->nr; i++) {
6092                        struct diff_filepair *p = q->queue[i];
6093                        if (check_pair_status(p))
6094                                diff_flush_patch(p, options);
6095                        if (options->found_changes)
6096                                break;
6097                }
6098        }
6099
6100        if (output_format & DIFF_FORMAT_PATCH) {
6101                if (separator) {
6102                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
6103                        if (options->stat_sep)
6104                                /* attach patch instead of inline */
6105                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
6106                                                 NULL, 0, 0);
6107                }
6108
6109                diff_flush_patch_all_file_pairs(options);
6110        }
6111
6112        if (output_format & DIFF_FORMAT_CALLBACK)
6113                options->format_callback(q, options, options->format_callback_data);
6114
6115        for (i = 0; i < q->nr; i++)
6116                diff_free_filepair(q->queue[i]);
6117free_queue:
6118        free(q->queue);
6119        DIFF_QUEUE_CLEAR(q);
6120        if (options->close_file)
6121                fclose(options->file);
6122
6123        /*
6124         * Report the content-level differences with HAS_CHANGES;
6125         * diff_addremove/diff_change does not set the bit when
6126         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6127         */
6128        if (options->flags.diff_from_contents) {
6129                if (options->found_changes)
6130                        options->flags.has_changes = 1;
6131                else
6132                        options->flags.has_changes = 0;
6133        }
6134}
6135
6136static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6137{
6138        return (((p->status == DIFF_STATUS_MODIFIED) &&
6139                 ((p->score &&
6140                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6141                  (!p->score &&
6142                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6143                ((p->status != DIFF_STATUS_MODIFIED) &&
6144                 filter_bit_tst(p->status, options)));
6145}
6146
6147static void diffcore_apply_filter(struct diff_options *options)
6148{
6149        int i;
6150        struct diff_queue_struct *q = &diff_queued_diff;
6151        struct diff_queue_struct outq;
6152
6153        DIFF_QUEUE_CLEAR(&outq);
6154
6155        if (!options->filter)
6156                return;
6157
6158        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6159                int found;
6160                for (i = found = 0; !found && i < q->nr; i++) {
6161                        if (match_filter(options, q->queue[i]))
6162                                found++;
6163                }
6164                if (found)
6165                        return;
6166
6167                /* otherwise we will clear the whole queue
6168                 * by copying the empty outq at the end of this
6169                 * function, but first clear the current entries
6170                 * in the queue.
6171                 */
6172                for (i = 0; i < q->nr; i++)
6173                        diff_free_filepair(q->queue[i]);
6174        }
6175        else {
6176                /* Only the matching ones */
6177                for (i = 0; i < q->nr; i++) {
6178                        struct diff_filepair *p = q->queue[i];
6179                        if (match_filter(options, p))
6180                                diff_q(&outq, p);
6181                        else
6182                                diff_free_filepair(p);
6183                }
6184        }
6185        free(q->queue);
6186        *q = outq;
6187}
6188
6189/* Check whether two filespecs with the same mode and size are identical */
6190static int diff_filespec_is_identical(struct repository *r,
6191                                      struct diff_filespec *one,
6192                                      struct diff_filespec *two)
6193{
6194        if (S_ISGITLINK(one->mode))
6195                return 0;
6196        if (diff_populate_filespec(r, one, 0))
6197                return 0;
6198        if (diff_populate_filespec(r, two, 0))
6199                return 0;
6200        return !memcmp(one->data, two->data, one->size);
6201}
6202
6203static int diff_filespec_check_stat_unmatch(struct repository *r,
6204                                            struct diff_filepair *p)
6205{
6206        if (p->done_skip_stat_unmatch)
6207                return p->skip_stat_unmatch_result;
6208
6209        p->done_skip_stat_unmatch = 1;
6210        p->skip_stat_unmatch_result = 0;
6211        /*
6212         * 1. Entries that come from stat info dirtiness
6213         *    always have both sides (iow, not create/delete),
6214         *    one side of the object name is unknown, with
6215         *    the same mode and size.  Keep the ones that
6216         *    do not match these criteria.  They have real
6217         *    differences.
6218         *
6219         * 2. At this point, the file is known to be modified,
6220         *    with the same mode and size, and the object
6221         *    name of one side is unknown.  Need to inspect
6222         *    the identical contents.
6223         */
6224        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6225            !DIFF_FILE_VALID(p->two) ||
6226            (p->one->oid_valid && p->two->oid_valid) ||
6227            (p->one->mode != p->two->mode) ||
6228            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6229            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6230            (p->one->size != p->two->size) ||
6231            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6232                p->skip_stat_unmatch_result = 1;
6233        return p->skip_stat_unmatch_result;
6234}
6235
6236static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6237{
6238        int i;
6239        struct diff_queue_struct *q = &diff_queued_diff;
6240        struct diff_queue_struct outq;
6241        DIFF_QUEUE_CLEAR(&outq);
6242
6243        for (i = 0; i < q->nr; i++) {
6244                struct diff_filepair *p = q->queue[i];
6245
6246                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6247                        diff_q(&outq, p);
6248                else {
6249                        /*
6250                         * The caller can subtract 1 from skip_stat_unmatch
6251                         * to determine how many paths were dirty only
6252                         * due to stat info mismatch.
6253                         */
6254                        if (!diffopt->flags.no_index)
6255                                diffopt->skip_stat_unmatch++;
6256                        diff_free_filepair(p);
6257                }
6258        }
6259        free(q->queue);
6260        *q = outq;
6261}
6262
6263static int diffnamecmp(const void *a_, const void *b_)
6264{
6265        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6266        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6267        const char *name_a, *name_b;
6268
6269        name_a = a->one ? a->one->path : a->two->path;
6270        name_b = b->one ? b->one->path : b->two->path;
6271        return strcmp(name_a, name_b);
6272}
6273
6274void diffcore_fix_diff_index(struct diff_options *options)
6275{
6276        struct diff_queue_struct *q = &diff_queued_diff;
6277        QSORT(q->queue, q->nr, diffnamecmp);
6278}
6279
6280void diffcore_std(struct diff_options *options)
6281{
6282        /* NOTE please keep the following in sync with diff_tree_combined() */
6283        if (options->skip_stat_unmatch)
6284                diffcore_skip_stat_unmatch(options);
6285        if (!options->found_follow) {
6286                /* See try_to_follow_renames() in tree-diff.c */
6287                if (options->break_opt != -1)
6288                        diffcore_break(options->repo,
6289                                       options->break_opt);
6290                if (options->detect_rename)
6291                        diffcore_rename(options);
6292                if (options->break_opt != -1)
6293                        diffcore_merge_broken();
6294        }
6295        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6296                diffcore_pickaxe(options);
6297        if (options->orderfile)
6298                diffcore_order(options->orderfile);
6299        if (!options->found_follow)
6300                /* See try_to_follow_renames() in tree-diff.c */
6301                diff_resolve_rename_copy();
6302        diffcore_apply_filter(options);
6303
6304        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6305                options->flags.has_changes = 1;
6306        else
6307                options->flags.has_changes = 0;
6308
6309        options->found_follow = 0;
6310}
6311
6312int diff_result_code(struct diff_options *opt, int status)
6313{
6314        int result = 0;
6315
6316        diff_warn_rename_limit("diff.renameLimit",
6317                               opt->needed_rename_limit,
6318                               opt->degraded_cc_to_c);
6319        if (!opt->flags.exit_with_status &&
6320            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6321                return status;
6322        if (opt->flags.exit_with_status &&
6323            opt->flags.has_changes)
6324                result |= 01;
6325        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6326            opt->flags.check_failed)
6327                result |= 02;
6328        return result;
6329}
6330
6331int diff_can_quit_early(struct diff_options *opt)
6332{
6333        return (opt->flags.quick &&
6334                !opt->filter &&
6335                opt->flags.has_changes);
6336}
6337
6338/*
6339 * Shall changes to this submodule be ignored?
6340 *
6341 * Submodule changes can be configured to be ignored separately for each path,
6342 * but that configuration can be overridden from the command line.
6343 */
6344static int is_submodule_ignored(const char *path, struct diff_options *options)
6345{
6346        int ignored = 0;
6347        struct diff_flags orig_flags = options->flags;
6348        if (!options->flags.override_submodule_config)
6349                set_diffopt_flags_from_submodule_config(options, path);
6350        if (options->flags.ignore_submodules)
6351                ignored = 1;
6352        options->flags = orig_flags;
6353        return ignored;
6354}
6355
6356void diff_addremove(struct diff_options *options,
6357                    int addremove, unsigned mode,
6358                    const struct object_id *oid,
6359                    int oid_valid,
6360                    const char *concatpath, unsigned dirty_submodule)
6361{
6362        struct diff_filespec *one, *two;
6363
6364        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6365                return;
6366
6367        /* This may look odd, but it is a preparation for
6368         * feeding "there are unchanged files which should
6369         * not produce diffs, but when you are doing copy
6370         * detection you would need them, so here they are"
6371         * entries to the diff-core.  They will be prefixed
6372         * with something like '=' or '*' (I haven't decided
6373         * which but should not make any difference).
6374         * Feeding the same new and old to diff_change()
6375         * also has the same effect.
6376         * Before the final output happens, they are pruned after
6377         * merged into rename/copy pairs as appropriate.
6378         */
6379        if (options->flags.reverse_diff)
6380                addremove = (addremove == '+' ? '-' :
6381                             addremove == '-' ? '+' : addremove);
6382
6383        if (options->prefix &&
6384            strncmp(concatpath, options->prefix, options->prefix_length))
6385                return;
6386
6387        one = alloc_filespec(concatpath);
6388        two = alloc_filespec(concatpath);
6389
6390        if (addremove != '+')
6391                fill_filespec(one, oid, oid_valid, mode);
6392        if (addremove != '-') {
6393                fill_filespec(two, oid, oid_valid, mode);
6394                two->dirty_submodule = dirty_submodule;
6395        }
6396
6397        diff_queue(&diff_queued_diff, one, two);
6398        if (!options->flags.diff_from_contents)
6399                options->flags.has_changes = 1;
6400}
6401
6402void diff_change(struct diff_options *options,
6403                 unsigned old_mode, unsigned new_mode,
6404                 const struct object_id *old_oid,
6405                 const struct object_id *new_oid,
6406                 int old_oid_valid, int new_oid_valid,
6407                 const char *concatpath,
6408                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6409{
6410        struct diff_filespec *one, *two;
6411        struct diff_filepair *p;
6412
6413        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6414            is_submodule_ignored(concatpath, options))
6415                return;
6416
6417        if (options->flags.reverse_diff) {
6418                SWAP(old_mode, new_mode);
6419                SWAP(old_oid, new_oid);
6420                SWAP(old_oid_valid, new_oid_valid);
6421                SWAP(old_dirty_submodule, new_dirty_submodule);
6422        }
6423
6424        if (options->prefix &&
6425            strncmp(concatpath, options->prefix, options->prefix_length))
6426                return;
6427
6428        one = alloc_filespec(concatpath);
6429        two = alloc_filespec(concatpath);
6430        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6431        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6432        one->dirty_submodule = old_dirty_submodule;
6433        two->dirty_submodule = new_dirty_submodule;
6434        p = diff_queue(&diff_queued_diff, one, two);
6435
6436        if (options->flags.diff_from_contents)
6437                return;
6438
6439        if (options->flags.quick && options->skip_stat_unmatch &&
6440            !diff_filespec_check_stat_unmatch(options->repo, p))
6441                return;
6442
6443        options->flags.has_changes = 1;
6444}
6445
6446struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6447{
6448        struct diff_filepair *pair;
6449        struct diff_filespec *one, *two;
6450
6451        if (options->prefix &&
6452            strncmp(path, options->prefix, options->prefix_length))
6453                return NULL;
6454
6455        one = alloc_filespec(path);
6456        two = alloc_filespec(path);
6457        pair = diff_queue(&diff_queued_diff, one, two);
6458        pair->is_unmerged = 1;
6459        return pair;
6460}
6461
6462static char *run_textconv(struct repository *r,
6463                          const char *pgm,
6464                          struct diff_filespec *spec,
6465                          size_t *outsize)
6466{
6467        struct diff_tempfile *temp;
6468        const char *argv[3];
6469        const char **arg = argv;
6470        struct child_process child = CHILD_PROCESS_INIT;
6471        struct strbuf buf = STRBUF_INIT;
6472        int err = 0;
6473
6474        temp = prepare_temp_file(r, spec->path, spec);
6475        *arg++ = pgm;
6476        *arg++ = temp->name;
6477        *arg = NULL;
6478
6479        child.use_shell = 1;
6480        child.argv = argv;
6481        child.out = -1;
6482        if (start_command(&child)) {
6483                remove_tempfile();
6484                return NULL;
6485        }
6486
6487        if (strbuf_read(&buf, child.out, 0) < 0)
6488                err = error("error reading from textconv command '%s'", pgm);
6489        close(child.out);
6490
6491        if (finish_command(&child) || err) {
6492                strbuf_release(&buf);
6493                remove_tempfile();
6494                return NULL;
6495        }
6496        remove_tempfile();
6497
6498        return strbuf_detach(&buf, outsize);
6499}
6500
6501size_t fill_textconv(struct repository *r,
6502                     struct userdiff_driver *driver,
6503                     struct diff_filespec *df,
6504                     char **outbuf)
6505{
6506        size_t size;
6507
6508        if (!driver) {
6509                if (!DIFF_FILE_VALID(df)) {
6510                        *outbuf = "";
6511                        return 0;
6512                }
6513                if (diff_populate_filespec(r, df, 0))
6514                        die("unable to read files to diff");
6515                *outbuf = df->data;
6516                return df->size;
6517        }
6518
6519        if (!driver->textconv)
6520                BUG("fill_textconv called with non-textconv driver");
6521
6522        if (driver->textconv_cache && df->oid_valid) {
6523                *outbuf = notes_cache_get(driver->textconv_cache,
6524                                          &df->oid,
6525                                          &size);
6526                if (*outbuf)
6527                        return size;
6528        }
6529
6530        *outbuf = run_textconv(r, driver->textconv, df, &size);
6531        if (!*outbuf)
6532                die("unable to read files to diff");
6533
6534        if (driver->textconv_cache && df->oid_valid) {
6535                /* ignore errors, as we might be in a readonly repository */
6536                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6537                                size);
6538                /*
6539                 * we could save up changes and flush them all at the end,
6540                 * but we would need an extra call after all diffing is done.
6541                 * Since generating a cache entry is the slow path anyway,
6542                 * this extra overhead probably isn't a big deal.
6543                 */
6544                notes_cache_write(driver->textconv_cache);
6545        }
6546
6547        return size;
6548}
6549
6550int textconv_object(struct repository *r,
6551                    const char *path,
6552                    unsigned mode,
6553                    const struct object_id *oid,
6554                    int oid_valid,
6555                    char **buf,
6556                    unsigned long *buf_size)
6557{
6558        struct diff_filespec *df;
6559        struct userdiff_driver *textconv;
6560
6561        df = alloc_filespec(path);
6562        fill_filespec(df, oid, oid_valid, mode);
6563        textconv = get_textconv(r, df);
6564        if (!textconv) {
6565                free_filespec(df);
6566                return 0;
6567        }
6568
6569        *buf_size = fill_textconv(r, textconv, df, buf);
6570        free_filespec(df);
6571        return 1;
6572}
6573
6574void setup_diff_pager(struct diff_options *opt)
6575{
6576        /*
6577         * If the user asked for our exit code, then either they want --quiet
6578         * or --exit-code. We should definitely not bother with a pager in the
6579         * former case, as we will generate no output. Since we still properly
6580         * report our exit code even when a pager is run, we _could_ run a
6581         * pager with --exit-code. But since we have not done so historically,
6582         * and because it is easy to find people oneline advising "git diff
6583         * --exit-code" in hooks and other scripts, we do not do so.
6584         */
6585        if (!opt->flags.exit_with_status &&
6586            check_pager_config("diff") != 0)
6587                setup_pager();
6588}