diff.con commit Merge branch 'ab/receive-pack-use-after-free-fix' (4751a16)
   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(struct emit_callback *ecbdata,
1618                          const char *line, int len)
1619{
1620        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1621        if (new_blank_line_at_eof(ecbdata, line, len))
1622                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1623
1624        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1625}
1626
1627static void emit_del_line(struct emit_callback *ecbdata,
1628                          const char *line, int len)
1629{
1630        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1631        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1632}
1633
1634static void emit_context_line(struct emit_callback *ecbdata,
1635                              const char *line, int len)
1636{
1637        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1638        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1639}
1640
1641static void emit_hunk_header(struct emit_callback *ecbdata,
1642                             const char *line, int len)
1643{
1644        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1645        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1646        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1647        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1648        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1649        static const char atat[2] = { '@', '@' };
1650        const char *cp, *ep;
1651        struct strbuf msgbuf = STRBUF_INIT;
1652        int org_len = len;
1653        int i = 1;
1654
1655        /*
1656         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1657         * it always is at least 10 bytes long.
1658         */
1659        if (len < 10 ||
1660            memcmp(line, atat, 2) ||
1661            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1662                emit_diff_symbol(ecbdata->opt,
1663                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1664                return;
1665        }
1666        ep += 2; /* skip over @@ */
1667
1668        /* The hunk header in fraginfo color */
1669        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1670                strbuf_addstr(&msgbuf, reverse);
1671        strbuf_addstr(&msgbuf, frag);
1672        strbuf_add(&msgbuf, line, ep - line);
1673        strbuf_addstr(&msgbuf, reset);
1674
1675        /*
1676         * trailing "\r\n"
1677         */
1678        for ( ; i < 3; i++)
1679                if (line[len - i] == '\r' || line[len - i] == '\n')
1680                        len--;
1681
1682        /* blank before the func header */
1683        for (cp = ep; ep - line < len; ep++)
1684                if (*ep != ' ' && *ep != '\t')
1685                        break;
1686        if (ep != cp) {
1687                strbuf_addstr(&msgbuf, context);
1688                strbuf_add(&msgbuf, cp, ep - cp);
1689                strbuf_addstr(&msgbuf, reset);
1690        }
1691
1692        if (ep < line + len) {
1693                strbuf_addstr(&msgbuf, func);
1694                strbuf_add(&msgbuf, ep, line + len - ep);
1695                strbuf_addstr(&msgbuf, reset);
1696        }
1697
1698        strbuf_add(&msgbuf, line + len, org_len - len);
1699        strbuf_complete_line(&msgbuf);
1700        emit_diff_symbol(ecbdata->opt,
1701                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1702        strbuf_release(&msgbuf);
1703}
1704
1705static struct diff_tempfile *claim_diff_tempfile(void)
1706{
1707        int i;
1708        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1709                if (!diff_temp[i].name)
1710                        return diff_temp + i;
1711        BUG("diff is failing to clean up its tempfiles");
1712}
1713
1714static void remove_tempfile(void)
1715{
1716        int i;
1717        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1718                if (is_tempfile_active(diff_temp[i].tempfile))
1719                        delete_tempfile(&diff_temp[i].tempfile);
1720                diff_temp[i].name = NULL;
1721        }
1722}
1723
1724static void add_line_count(struct strbuf *out, int count)
1725{
1726        switch (count) {
1727        case 0:
1728                strbuf_addstr(out, "0,0");
1729                break;
1730        case 1:
1731                strbuf_addstr(out, "1");
1732                break;
1733        default:
1734                strbuf_addf(out, "1,%d", count);
1735                break;
1736        }
1737}
1738
1739static void emit_rewrite_lines(struct emit_callback *ecb,
1740                               int prefix, const char *data, int size)
1741{
1742        const char *endp = NULL;
1743
1744        while (0 < size) {
1745                int len;
1746
1747                endp = memchr(data, '\n', size);
1748                len = endp ? (endp - data + 1) : size;
1749                if (prefix != '+') {
1750                        ecb->lno_in_preimage++;
1751                        emit_del_line(ecb, data, len);
1752                } else {
1753                        ecb->lno_in_postimage++;
1754                        emit_add_line(ecb, data, len);
1755                }
1756                size -= len;
1757                data += len;
1758        }
1759        if (!endp)
1760                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1761}
1762
1763static void emit_rewrite_diff(const char *name_a,
1764                              const char *name_b,
1765                              struct diff_filespec *one,
1766                              struct diff_filespec *two,
1767                              struct userdiff_driver *textconv_one,
1768                              struct userdiff_driver *textconv_two,
1769                              struct diff_options *o)
1770{
1771        int lc_a, lc_b;
1772        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1773        const char *a_prefix, *b_prefix;
1774        char *data_one, *data_two;
1775        size_t size_one, size_two;
1776        struct emit_callback ecbdata;
1777        struct strbuf out = STRBUF_INIT;
1778
1779        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1780                a_prefix = o->b_prefix;
1781                b_prefix = o->a_prefix;
1782        } else {
1783                a_prefix = o->a_prefix;
1784                b_prefix = o->b_prefix;
1785        }
1786
1787        name_a += (*name_a == '/');
1788        name_b += (*name_b == '/');
1789
1790        strbuf_reset(&a_name);
1791        strbuf_reset(&b_name);
1792        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1793        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1794
1795        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1796        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1797
1798        memset(&ecbdata, 0, sizeof(ecbdata));
1799        ecbdata.color_diff = want_color(o->use_color);
1800        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1801        ecbdata.opt = o;
1802        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1803                mmfile_t mf1, mf2;
1804                mf1.ptr = (char *)data_one;
1805                mf2.ptr = (char *)data_two;
1806                mf1.size = size_one;
1807                mf2.size = size_two;
1808                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1809        }
1810        ecbdata.lno_in_preimage = 1;
1811        ecbdata.lno_in_postimage = 1;
1812
1813        lc_a = count_lines(data_one, size_one);
1814        lc_b = count_lines(data_two, size_two);
1815
1816        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1817                         a_name.buf, a_name.len, 0);
1818        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1819                         b_name.buf, b_name.len, 0);
1820
1821        strbuf_addstr(&out, "@@ -");
1822        if (!o->irreversible_delete)
1823                add_line_count(&out, lc_a);
1824        else
1825                strbuf_addstr(&out, "?,?");
1826        strbuf_addstr(&out, " +");
1827        add_line_count(&out, lc_b);
1828        strbuf_addstr(&out, " @@\n");
1829        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1830        strbuf_release(&out);
1831
1832        if (lc_a && !o->irreversible_delete)
1833                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1834        if (lc_b)
1835                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1836        if (textconv_one)
1837                free((char *)data_one);
1838        if (textconv_two)
1839                free((char *)data_two);
1840}
1841
1842struct diff_words_buffer {
1843        mmfile_t text;
1844        unsigned long alloc;
1845        struct diff_words_orig {
1846                const char *begin, *end;
1847        } *orig;
1848        int orig_nr, orig_alloc;
1849};
1850
1851static void diff_words_append(char *line, unsigned long len,
1852                struct diff_words_buffer *buffer)
1853{
1854        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1855        line++;
1856        len--;
1857        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1858        buffer->text.size += len;
1859        buffer->text.ptr[buffer->text.size] = '\0';
1860}
1861
1862struct diff_words_style_elem {
1863        const char *prefix;
1864        const char *suffix;
1865        const char *color; /* NULL; filled in by the setup code if
1866                            * color is enabled */
1867};
1868
1869struct diff_words_style {
1870        enum diff_words_type type;
1871        struct diff_words_style_elem new_word, old_word, ctx;
1872        const char *newline;
1873};
1874
1875static struct diff_words_style diff_words_styles[] = {
1876        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1877        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1878        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1879};
1880
1881struct diff_words_data {
1882        struct diff_words_buffer minus, plus;
1883        const char *current_plus;
1884        int last_minus;
1885        struct diff_options *opt;
1886        regex_t *word_regex;
1887        enum diff_words_type type;
1888        struct diff_words_style *style;
1889};
1890
1891static int fn_out_diff_words_write_helper(struct diff_options *o,
1892                                          struct diff_words_style_elem *st_el,
1893                                          const char *newline,
1894                                          size_t count, const char *buf)
1895{
1896        int print = 0;
1897        struct strbuf sb = STRBUF_INIT;
1898
1899        while (count) {
1900                char *p = memchr(buf, '\n', count);
1901                if (print)
1902                        strbuf_addstr(&sb, diff_line_prefix(o));
1903
1904                if (p != buf) {
1905                        const char *reset = st_el->color && *st_el->color ?
1906                                            GIT_COLOR_RESET : NULL;
1907                        if (st_el->color && *st_el->color)
1908                                strbuf_addstr(&sb, st_el->color);
1909                        strbuf_addstr(&sb, st_el->prefix);
1910                        strbuf_add(&sb, buf, p ? p - buf : count);
1911                        strbuf_addstr(&sb, st_el->suffix);
1912                        if (reset)
1913                                strbuf_addstr(&sb, reset);
1914                }
1915                if (!p)
1916                        goto out;
1917
1918                strbuf_addstr(&sb, newline);
1919                count -= p + 1 - buf;
1920                buf = p + 1;
1921                print = 1;
1922                if (count) {
1923                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1924                                         sb.buf, sb.len, 0);
1925                        strbuf_reset(&sb);
1926                }
1927        }
1928
1929out:
1930        if (sb.len)
1931                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1932                                 sb.buf, sb.len, 0);
1933        strbuf_release(&sb);
1934        return 0;
1935}
1936
1937/*
1938 * '--color-words' algorithm can be described as:
1939 *
1940 *   1. collect the minus/plus lines of a diff hunk, divided into
1941 *      minus-lines and plus-lines;
1942 *
1943 *   2. break both minus-lines and plus-lines into words and
1944 *      place them into two mmfile_t with one word for each line;
1945 *
1946 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1947 *
1948 * And for the common parts of the both file, we output the plus side text.
1949 * diff_words->current_plus is used to trace the current position of the plus file
1950 * which printed. diff_words->last_minus is used to trace the last minus word
1951 * printed.
1952 *
1953 * For '--graph' to work with '--color-words', we need to output the graph prefix
1954 * on each line of color words output. Generally, there are two conditions on
1955 * which we should output the prefix.
1956 *
1957 *   1. diff_words->last_minus == 0 &&
1958 *      diff_words->current_plus == diff_words->plus.text.ptr
1959 *
1960 *      that is: the plus text must start as a new line, and if there is no minus
1961 *      word printed, a graph prefix must be printed.
1962 *
1963 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1964 *      *(diff_words->current_plus - 1) == '\n'
1965 *
1966 *      that is: a graph prefix must be printed following a '\n'
1967 */
1968static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1969{
1970        if ((diff_words->last_minus == 0 &&
1971                diff_words->current_plus == diff_words->plus.text.ptr) ||
1972                (diff_words->current_plus > diff_words->plus.text.ptr &&
1973                *(diff_words->current_plus - 1) == '\n')) {
1974                return 1;
1975        } else {
1976                return 0;
1977        }
1978}
1979
1980static void fn_out_diff_words_aux(void *priv,
1981                                  long minus_first, long minus_len,
1982                                  long plus_first, long plus_len,
1983                                  const char *func, long funclen)
1984{
1985        struct diff_words_data *diff_words = priv;
1986        struct diff_words_style *style = diff_words->style;
1987        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1988        struct diff_options *opt = diff_words->opt;
1989        const char *line_prefix;
1990
1991        assert(opt);
1992        line_prefix = diff_line_prefix(opt);
1993
1994        /* POSIX requires that first be decremented by one if len == 0... */
1995        if (minus_len) {
1996                minus_begin = diff_words->minus.orig[minus_first].begin;
1997                minus_end =
1998                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1999        } else
2000                minus_begin = minus_end =
2001                        diff_words->minus.orig[minus_first].end;
2002
2003        if (plus_len) {
2004                plus_begin = diff_words->plus.orig[plus_first].begin;
2005                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
2006        } else
2007                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
2008
2009        if (color_words_output_graph_prefix(diff_words)) {
2010                fputs(line_prefix, diff_words->opt->file);
2011        }
2012        if (diff_words->current_plus != plus_begin) {
2013                fn_out_diff_words_write_helper(diff_words->opt,
2014                                &style->ctx, style->newline,
2015                                plus_begin - diff_words->current_plus,
2016                                diff_words->current_plus);
2017        }
2018        if (minus_begin != minus_end) {
2019                fn_out_diff_words_write_helper(diff_words->opt,
2020                                &style->old_word, style->newline,
2021                                minus_end - minus_begin, minus_begin);
2022        }
2023        if (plus_begin != plus_end) {
2024                fn_out_diff_words_write_helper(diff_words->opt,
2025                                &style->new_word, style->newline,
2026                                plus_end - plus_begin, plus_begin);
2027        }
2028
2029        diff_words->current_plus = plus_end;
2030        diff_words->last_minus = minus_first;
2031}
2032
2033/* This function starts looking at *begin, and returns 0 iff a word was found. */
2034static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
2035                int *begin, int *end)
2036{
2037        if (word_regex && *begin < buffer->size) {
2038                regmatch_t match[1];
2039                if (!regexec_buf(word_regex, buffer->ptr + *begin,
2040                                 buffer->size - *begin, 1, match, 0)) {
2041                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
2042                                        '\n', match[0].rm_eo - match[0].rm_so);
2043                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
2044                        *begin += match[0].rm_so;
2045                        return *begin >= *end;
2046                }
2047                return -1;
2048        }
2049
2050        /* find the next word */
2051        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
2052                (*begin)++;
2053        if (*begin >= buffer->size)
2054                return -1;
2055
2056        /* find the end of the word */
2057        *end = *begin + 1;
2058        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
2059                (*end)++;
2060
2061        return 0;
2062}
2063
2064/*
2065 * This function splits the words in buffer->text, stores the list with
2066 * newline separator into out, and saves the offsets of the original words
2067 * in buffer->orig.
2068 */
2069static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2070                regex_t *word_regex)
2071{
2072        int i, j;
2073        long alloc = 0;
2074
2075        out->size = 0;
2076        out->ptr = NULL;
2077
2078        /* fake an empty "0th" word */
2079        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2080        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2081        buffer->orig_nr = 1;
2082
2083        for (i = 0; i < buffer->text.size; i++) {
2084                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2085                        return;
2086
2087                /* store original boundaries */
2088                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2089                                buffer->orig_alloc);
2090                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2091                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2092                buffer->orig_nr++;
2093
2094                /* store one word */
2095                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2096                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2097                out->ptr[out->size + j - i] = '\n';
2098                out->size += j - i + 1;
2099
2100                i = j - 1;
2101        }
2102}
2103
2104/* this executes the word diff on the accumulated buffers */
2105static void diff_words_show(struct diff_words_data *diff_words)
2106{
2107        xpparam_t xpp;
2108        xdemitconf_t xecfg;
2109        mmfile_t minus, plus;
2110        struct diff_words_style *style = diff_words->style;
2111
2112        struct diff_options *opt = diff_words->opt;
2113        const char *line_prefix;
2114
2115        assert(opt);
2116        line_prefix = diff_line_prefix(opt);
2117
2118        /* special case: only removal */
2119        if (!diff_words->plus.text.size) {
2120                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2121                                 line_prefix, strlen(line_prefix), 0);
2122                fn_out_diff_words_write_helper(diff_words->opt,
2123                        &style->old_word, style->newline,
2124                        diff_words->minus.text.size,
2125                        diff_words->minus.text.ptr);
2126                diff_words->minus.text.size = 0;
2127                return;
2128        }
2129
2130        diff_words->current_plus = diff_words->plus.text.ptr;
2131        diff_words->last_minus = 0;
2132
2133        memset(&xpp, 0, sizeof(xpp));
2134        memset(&xecfg, 0, sizeof(xecfg));
2135        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2136        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2137        xpp.flags = 0;
2138        /* as only the hunk header will be parsed, we need a 0-context */
2139        xecfg.ctxlen = 0;
2140        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2141                          diff_words, &xpp, &xecfg))
2142                die("unable to generate word diff");
2143        free(minus.ptr);
2144        free(plus.ptr);
2145        if (diff_words->current_plus != diff_words->plus.text.ptr +
2146                        diff_words->plus.text.size) {
2147                if (color_words_output_graph_prefix(diff_words))
2148                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2149                                         line_prefix, strlen(line_prefix), 0);
2150                fn_out_diff_words_write_helper(diff_words->opt,
2151                        &style->ctx, style->newline,
2152                        diff_words->plus.text.ptr + diff_words->plus.text.size
2153                        - diff_words->current_plus, diff_words->current_plus);
2154        }
2155        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2156}
2157
2158/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2159static void diff_words_flush(struct emit_callback *ecbdata)
2160{
2161        struct diff_options *wo = ecbdata->diff_words->opt;
2162
2163        if (ecbdata->diff_words->minus.text.size ||
2164            ecbdata->diff_words->plus.text.size)
2165                diff_words_show(ecbdata->diff_words);
2166
2167        if (wo->emitted_symbols) {
2168                struct diff_options *o = ecbdata->opt;
2169                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2170                int i;
2171
2172                /*
2173                 * NEEDSWORK:
2174                 * Instead of appending each, concat all words to a line?
2175                 */
2176                for (i = 0; i < wol->nr; i++)
2177                        append_emitted_diff_symbol(o, &wol->buf[i]);
2178
2179                for (i = 0; i < wol->nr; i++)
2180                        free((void *)wol->buf[i].line);
2181
2182                wol->nr = 0;
2183        }
2184}
2185
2186static void diff_filespec_load_driver(struct diff_filespec *one,
2187                                      struct index_state *istate)
2188{
2189        /* Use already-loaded driver */
2190        if (one->driver)
2191                return;
2192
2193        if (S_ISREG(one->mode))
2194                one->driver = userdiff_find_by_path(istate, one->path);
2195
2196        /* Fallback to default settings */
2197        if (!one->driver)
2198                one->driver = userdiff_find_by_name("default");
2199}
2200
2201static const char *userdiff_word_regex(struct diff_filespec *one,
2202                                       struct index_state *istate)
2203{
2204        diff_filespec_load_driver(one, istate);
2205        return one->driver->word_regex;
2206}
2207
2208static void init_diff_words_data(struct emit_callback *ecbdata,
2209                                 struct diff_options *orig_opts,
2210                                 struct diff_filespec *one,
2211                                 struct diff_filespec *two)
2212{
2213        int i;
2214        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2215        memcpy(o, orig_opts, sizeof(struct diff_options));
2216
2217        ecbdata->diff_words =
2218                xcalloc(1, sizeof(struct diff_words_data));
2219        ecbdata->diff_words->type = o->word_diff;
2220        ecbdata->diff_words->opt = o;
2221
2222        if (orig_opts->emitted_symbols)
2223                o->emitted_symbols =
2224                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2225
2226        if (!o->word_regex)
2227                o->word_regex = userdiff_word_regex(one, o->repo->index);
2228        if (!o->word_regex)
2229                o->word_regex = userdiff_word_regex(two, o->repo->index);
2230        if (!o->word_regex)
2231                o->word_regex = diff_word_regex_cfg;
2232        if (o->word_regex) {
2233                ecbdata->diff_words->word_regex = (regex_t *)
2234                        xmalloc(sizeof(regex_t));
2235                if (regcomp(ecbdata->diff_words->word_regex,
2236                            o->word_regex,
2237                            REG_EXTENDED | REG_NEWLINE))
2238                        die("invalid regular expression: %s",
2239                            o->word_regex);
2240        }
2241        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2242                if (o->word_diff == diff_words_styles[i].type) {
2243                        ecbdata->diff_words->style =
2244                                &diff_words_styles[i];
2245                        break;
2246                }
2247        }
2248        if (want_color(o->use_color)) {
2249                struct diff_words_style *st = ecbdata->diff_words->style;
2250                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2251                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2252                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2253        }
2254}
2255
2256static void free_diff_words_data(struct emit_callback *ecbdata)
2257{
2258        if (ecbdata->diff_words) {
2259                diff_words_flush(ecbdata);
2260                free (ecbdata->diff_words->opt->emitted_symbols);
2261                free (ecbdata->diff_words->opt);
2262                free (ecbdata->diff_words->minus.text.ptr);
2263                free (ecbdata->diff_words->minus.orig);
2264                free (ecbdata->diff_words->plus.text.ptr);
2265                free (ecbdata->diff_words->plus.orig);
2266                if (ecbdata->diff_words->word_regex) {
2267                        regfree(ecbdata->diff_words->word_regex);
2268                        free(ecbdata->diff_words->word_regex);
2269                }
2270                FREE_AND_NULL(ecbdata->diff_words);
2271        }
2272}
2273
2274const char *diff_get_color(int diff_use_color, enum color_diff ix)
2275{
2276        if (want_color(diff_use_color))
2277                return diff_colors[ix];
2278        return "";
2279}
2280
2281const char *diff_line_prefix(struct diff_options *opt)
2282{
2283        struct strbuf *msgbuf;
2284        if (!opt->output_prefix)
2285                return "";
2286
2287        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2288        return msgbuf->buf;
2289}
2290
2291static unsigned long sane_truncate_line(char *line, unsigned long len)
2292{
2293        const char *cp;
2294        unsigned long allot;
2295        size_t l = len;
2296
2297        cp = line;
2298        allot = l;
2299        while (0 < l) {
2300                (void) utf8_width(&cp, &l);
2301                if (!cp)
2302                        break; /* truncated in the middle? */
2303        }
2304        return allot - l;
2305}
2306
2307static void find_lno(const char *line, struct emit_callback *ecbdata)
2308{
2309        const char *p;
2310        ecbdata->lno_in_preimage = 0;
2311        ecbdata->lno_in_postimage = 0;
2312        p = strchr(line, '-');
2313        if (!p)
2314                return; /* cannot happen */
2315        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2316        p = strchr(p, '+');
2317        if (!p)
2318                return; /* cannot happen */
2319        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2320}
2321
2322static void fn_out_consume(void *priv, char *line, unsigned long len)
2323{
2324        struct emit_callback *ecbdata = priv;
2325        struct diff_options *o = ecbdata->opt;
2326
2327        o->found_changes = 1;
2328
2329        if (ecbdata->header) {
2330                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2331                                 ecbdata->header->buf, ecbdata->header->len, 0);
2332                strbuf_reset(ecbdata->header);
2333                ecbdata->header = NULL;
2334        }
2335
2336        if (ecbdata->label_path[0]) {
2337                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2338                                 ecbdata->label_path[0],
2339                                 strlen(ecbdata->label_path[0]), 0);
2340                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2341                                 ecbdata->label_path[1],
2342                                 strlen(ecbdata->label_path[1]), 0);
2343                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2344        }
2345
2346        if (diff_suppress_blank_empty
2347            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2348                line[0] = '\n';
2349                len = 1;
2350        }
2351
2352        if (line[0] == '@') {
2353                if (ecbdata->diff_words)
2354                        diff_words_flush(ecbdata);
2355                len = sane_truncate_line(line, len);
2356                find_lno(line, ecbdata);
2357                emit_hunk_header(ecbdata, line, len);
2358                return;
2359        }
2360
2361        if (ecbdata->diff_words) {
2362                enum diff_symbol s =
2363                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2364                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2365                if (line[0] == '-') {
2366                        diff_words_append(line, len,
2367                                          &ecbdata->diff_words->minus);
2368                        return;
2369                } else if (line[0] == '+') {
2370                        diff_words_append(line, len,
2371                                          &ecbdata->diff_words->plus);
2372                        return;
2373                } else if (starts_with(line, "\\ ")) {
2374                        /*
2375                         * Eat the "no newline at eof" marker as if we
2376                         * saw a "+" or "-" line with nothing on it,
2377                         * and return without diff_words_flush() to
2378                         * defer processing. If this is the end of
2379                         * preimage, more "+" lines may come after it.
2380                         */
2381                        return;
2382                }
2383                diff_words_flush(ecbdata);
2384                emit_diff_symbol(o, s, line, len, 0);
2385                return;
2386        }
2387
2388        switch (line[0]) {
2389        case '+':
2390                ecbdata->lno_in_postimage++;
2391                emit_add_line(ecbdata, line + 1, len - 1);
2392                break;
2393        case '-':
2394                ecbdata->lno_in_preimage++;
2395                emit_del_line(ecbdata, line + 1, len - 1);
2396                break;
2397        case ' ':
2398                ecbdata->lno_in_postimage++;
2399                ecbdata->lno_in_preimage++;
2400                emit_context_line(ecbdata, line + 1, len - 1);
2401                break;
2402        default:
2403                /* incomplete line at the end */
2404                ecbdata->lno_in_preimage++;
2405                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2406                                 line, len, 0);
2407                break;
2408        }
2409}
2410
2411static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2412{
2413        const char *old_name = a;
2414        const char *new_name = b;
2415        int pfx_length, sfx_length;
2416        int pfx_adjust_for_slash;
2417        int len_a = strlen(a);
2418        int len_b = strlen(b);
2419        int a_midlen, b_midlen;
2420        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2421        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2422
2423        if (qlen_a || qlen_b) {
2424                quote_c_style(a, name, NULL, 0);
2425                strbuf_addstr(name, " => ");
2426                quote_c_style(b, name, NULL, 0);
2427                return;
2428        }
2429
2430        /* Find common prefix */
2431        pfx_length = 0;
2432        while (*old_name && *new_name && *old_name == *new_name) {
2433                if (*old_name == '/')
2434                        pfx_length = old_name - a + 1;
2435                old_name++;
2436                new_name++;
2437        }
2438
2439        /* Find common suffix */
2440        old_name = a + len_a;
2441        new_name = b + len_b;
2442        sfx_length = 0;
2443        /*
2444         * If there is a common prefix, it must end in a slash.  In
2445         * that case we let this loop run 1 into the prefix to see the
2446         * same slash.
2447         *
2448         * If there is no common prefix, we cannot do this as it would
2449         * underrun the input strings.
2450         */
2451        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2452        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2453               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2454               *old_name == *new_name) {
2455                if (*old_name == '/')
2456                        sfx_length = len_a - (old_name - a);
2457                old_name--;
2458                new_name--;
2459        }
2460
2461        /*
2462         * pfx{mid-a => mid-b}sfx
2463         * {pfx-a => pfx-b}sfx
2464         * pfx{sfx-a => sfx-b}
2465         * name-a => name-b
2466         */
2467        a_midlen = len_a - pfx_length - sfx_length;
2468        b_midlen = len_b - pfx_length - sfx_length;
2469        if (a_midlen < 0)
2470                a_midlen = 0;
2471        if (b_midlen < 0)
2472                b_midlen = 0;
2473
2474        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2475        if (pfx_length + sfx_length) {
2476                strbuf_add(name, a, pfx_length);
2477                strbuf_addch(name, '{');
2478        }
2479        strbuf_add(name, a + pfx_length, a_midlen);
2480        strbuf_addstr(name, " => ");
2481        strbuf_add(name, b + pfx_length, b_midlen);
2482        if (pfx_length + sfx_length) {
2483                strbuf_addch(name, '}');
2484                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2485        }
2486}
2487
2488struct diffstat_t {
2489        int nr;
2490        int alloc;
2491        struct diffstat_file {
2492                char *from_name;
2493                char *name;
2494                char *print_name;
2495                const char *comments;
2496                unsigned is_unmerged:1;
2497                unsigned is_binary:1;
2498                unsigned is_renamed:1;
2499                unsigned is_interesting:1;
2500                uintmax_t added, deleted;
2501        } **files;
2502};
2503
2504static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2505                                          const char *name_a,
2506                                          const char *name_b)
2507{
2508        struct diffstat_file *x;
2509        x = xcalloc(1, sizeof(*x));
2510        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2511        diffstat->files[diffstat->nr++] = x;
2512        if (name_b) {
2513                x->from_name = xstrdup(name_a);
2514                x->name = xstrdup(name_b);
2515                x->is_renamed = 1;
2516        }
2517        else {
2518                x->from_name = NULL;
2519                x->name = xstrdup(name_a);
2520        }
2521        return x;
2522}
2523
2524static void diffstat_consume(void *priv, char *line, unsigned long len)
2525{
2526        struct diffstat_t *diffstat = priv;
2527        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2528
2529        if (line[0] == '+')
2530                x->added++;
2531        else if (line[0] == '-')
2532                x->deleted++;
2533}
2534
2535const char mime_boundary_leader[] = "------------";
2536
2537static int scale_linear(int it, int width, int max_change)
2538{
2539        if (!it)
2540                return 0;
2541        /*
2542         * make sure that at least one '-' or '+' is printed if
2543         * there is any change to this path. The easiest way is to
2544         * scale linearly as if the alloted width is one column shorter
2545         * than it is, and then add 1 to the result.
2546         */
2547        return 1 + (it * (width - 1) / max_change);
2548}
2549
2550static void show_graph(struct strbuf *out, char ch, int cnt,
2551                       const char *set, const char *reset)
2552{
2553        if (cnt <= 0)
2554                return;
2555        strbuf_addstr(out, set);
2556        strbuf_addchars(out, ch, cnt);
2557        strbuf_addstr(out, reset);
2558}
2559
2560static void fill_print_name(struct diffstat_file *file)
2561{
2562        struct strbuf pname = STRBUF_INIT;
2563
2564        if (file->print_name)
2565                return;
2566
2567        if (file->is_renamed)
2568                pprint_rename(&pname, file->from_name, file->name);
2569        else
2570                quote_c_style(file->name, &pname, NULL, 0);
2571
2572        if (file->comments)
2573                strbuf_addf(&pname, " (%s)", file->comments);
2574
2575        file->print_name = strbuf_detach(&pname, NULL);
2576}
2577
2578static void print_stat_summary_inserts_deletes(struct diff_options *options,
2579                int files, int insertions, int deletions)
2580{
2581        struct strbuf sb = STRBUF_INIT;
2582
2583        if (!files) {
2584                assert(insertions == 0 && deletions == 0);
2585                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2586                                 NULL, 0, 0);
2587                return;
2588        }
2589
2590        strbuf_addf(&sb,
2591                    (files == 1) ? " %d file changed" : " %d files changed",
2592                    files);
2593
2594        /*
2595         * For binary diff, the caller may want to print "x files
2596         * changed" with insertions == 0 && deletions == 0.
2597         *
2598         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2599         * is probably less confusing (i.e skip over "2 files changed
2600         * but nothing about added/removed lines? Is this a bug in Git?").
2601         */
2602        if (insertions || deletions == 0) {
2603                strbuf_addf(&sb,
2604                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2605                            insertions);
2606        }
2607
2608        if (deletions || insertions == 0) {
2609                strbuf_addf(&sb,
2610                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2611                            deletions);
2612        }
2613        strbuf_addch(&sb, '\n');
2614        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2615                         sb.buf, sb.len, 0);
2616        strbuf_release(&sb);
2617}
2618
2619void print_stat_summary(FILE *fp, int files,
2620                        int insertions, int deletions)
2621{
2622        struct diff_options o;
2623        memset(&o, 0, sizeof(o));
2624        o.file = fp;
2625
2626        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2627}
2628
2629static void show_stats(struct diffstat_t *data, struct diff_options *options)
2630{
2631        int i, len, add, del, adds = 0, dels = 0;
2632        uintmax_t max_change = 0, max_len = 0;
2633        int total_files = data->nr, count;
2634        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2635        const char *reset, *add_c, *del_c;
2636        int extra_shown = 0;
2637        const char *line_prefix = diff_line_prefix(options);
2638        struct strbuf out = STRBUF_INIT;
2639
2640        if (data->nr == 0)
2641                return;
2642
2643        count = options->stat_count ? options->stat_count : data->nr;
2644
2645        reset = diff_get_color_opt(options, DIFF_RESET);
2646        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2647        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2648
2649        /*
2650         * Find the longest filename and max number of changes
2651         */
2652        for (i = 0; (i < count) && (i < data->nr); i++) {
2653                struct diffstat_file *file = data->files[i];
2654                uintmax_t change = file->added + file->deleted;
2655
2656                if (!file->is_interesting && (change == 0)) {
2657                        count++; /* not shown == room for one more */
2658                        continue;
2659                }
2660                fill_print_name(file);
2661                len = strlen(file->print_name);
2662                if (max_len < len)
2663                        max_len = len;
2664
2665                if (file->is_unmerged) {
2666                        /* "Unmerged" is 8 characters */
2667                        bin_width = bin_width < 8 ? 8 : bin_width;
2668                        continue;
2669                }
2670                if (file->is_binary) {
2671                        /* "Bin XXX -> YYY bytes" */
2672                        int w = 14 + decimal_width(file->added)
2673                                + decimal_width(file->deleted);
2674                        bin_width = bin_width < w ? w : bin_width;
2675                        /* Display change counts aligned with "Bin" */
2676                        number_width = 3;
2677                        continue;
2678                }
2679
2680                if (max_change < change)
2681                        max_change = change;
2682        }
2683        count = i; /* where we can stop scanning in data->files[] */
2684
2685        /*
2686         * We have width = stat_width or term_columns() columns total.
2687         * We want a maximum of min(max_len, stat_name_width) for the name part.
2688         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2689         * We also need 1 for " " and 4 + decimal_width(max_change)
2690         * for " | NNNN " and one the empty column at the end, altogether
2691         * 6 + decimal_width(max_change).
2692         *
2693         * If there's not enough space, we will use the smaller of
2694         * stat_name_width (if set) and 5/8*width for the filename,
2695         * and the rest for constant elements + graph part, but no more
2696         * than stat_graph_width for the graph part.
2697         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2698         * for the standard terminal size).
2699         *
2700         * In other words: stat_width limits the maximum width, and
2701         * stat_name_width fixes the maximum width of the filename,
2702         * and is also used to divide available columns if there
2703         * aren't enough.
2704         *
2705         * Binary files are displayed with "Bin XXX -> YYY bytes"
2706         * instead of the change count and graph. This part is treated
2707         * similarly to the graph part, except that it is not
2708         * "scaled". If total width is too small to accommodate the
2709         * guaranteed minimum width of the filename part and the
2710         * separators and this message, this message will "overflow"
2711         * making the line longer than the maximum width.
2712         */
2713
2714        if (options->stat_width == -1)
2715                width = term_columns() - strlen(line_prefix);
2716        else
2717                width = options->stat_width ? options->stat_width : 80;
2718        number_width = decimal_width(max_change) > number_width ?
2719                decimal_width(max_change) : number_width;
2720
2721        if (options->stat_graph_width == -1)
2722                options->stat_graph_width = diff_stat_graph_width;
2723
2724        /*
2725         * Guarantee 3/8*16==6 for the graph part
2726         * and 5/8*16==10 for the filename part
2727         */
2728        if (width < 16 + 6 + number_width)
2729                width = 16 + 6 + number_width;
2730
2731        /*
2732         * First assign sizes that are wanted, ignoring available width.
2733         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2734         * starting from "XXX" should fit in graph_width.
2735         */
2736        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2737        if (options->stat_graph_width &&
2738            options->stat_graph_width < graph_width)
2739                graph_width = options->stat_graph_width;
2740
2741        name_width = (options->stat_name_width > 0 &&
2742                      options->stat_name_width < max_len) ?
2743                options->stat_name_width : max_len;
2744
2745        /*
2746         * Adjust adjustable widths not to exceed maximum width
2747         */
2748        if (name_width + number_width + 6 + graph_width > width) {
2749                if (graph_width > width * 3/8 - number_width - 6) {
2750                        graph_width = width * 3/8 - number_width - 6;
2751                        if (graph_width < 6)
2752                                graph_width = 6;
2753                }
2754
2755                if (options->stat_graph_width &&
2756                    graph_width > options->stat_graph_width)
2757                        graph_width = options->stat_graph_width;
2758                if (name_width > width - number_width - 6 - graph_width)
2759                        name_width = width - number_width - 6 - graph_width;
2760                else
2761                        graph_width = width - number_width - 6 - name_width;
2762        }
2763
2764        /*
2765         * From here name_width is the width of the name area,
2766         * and graph_width is the width of the graph area.
2767         * max_change is used to scale graph properly.
2768         */
2769        for (i = 0; i < count; i++) {
2770                const char *prefix = "";
2771                struct diffstat_file *file = data->files[i];
2772                char *name = file->print_name;
2773                uintmax_t added = file->added;
2774                uintmax_t deleted = file->deleted;
2775                int name_len;
2776
2777                if (!file->is_interesting && (added + deleted == 0))
2778                        continue;
2779
2780                /*
2781                 * "scale" the filename
2782                 */
2783                len = name_width;
2784                name_len = strlen(name);
2785                if (name_width < name_len) {
2786                        char *slash;
2787                        prefix = "...";
2788                        len -= 3;
2789                        name += name_len - len;
2790                        slash = strchr(name, '/');
2791                        if (slash)
2792                                name = slash;
2793                }
2794
2795                if (file->is_binary) {
2796                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2797                        strbuf_addf(&out, " %*s", number_width, "Bin");
2798                        if (!added && !deleted) {
2799                                strbuf_addch(&out, '\n');
2800                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2801                                                 out.buf, out.len, 0);
2802                                strbuf_reset(&out);
2803                                continue;
2804                        }
2805                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2806                                del_c, deleted, reset);
2807                        strbuf_addstr(&out, " -> ");
2808                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2809                                add_c, added, reset);
2810                        strbuf_addstr(&out, " bytes\n");
2811                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2812                                         out.buf, out.len, 0);
2813                        strbuf_reset(&out);
2814                        continue;
2815                }
2816                else if (file->is_unmerged) {
2817                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2818                        strbuf_addstr(&out, " Unmerged\n");
2819                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2820                                         out.buf, out.len, 0);
2821                        strbuf_reset(&out);
2822                        continue;
2823                }
2824
2825                /*
2826                 * scale the add/delete
2827                 */
2828                add = added;
2829                del = deleted;
2830
2831                if (graph_width <= max_change) {
2832                        int total = scale_linear(add + del, graph_width, max_change);
2833                        if (total < 2 && add && del)
2834                                /* width >= 2 due to the sanity check */
2835                                total = 2;
2836                        if (add < del) {
2837                                add = scale_linear(add, graph_width, max_change);
2838                                del = total - add;
2839                        } else {
2840                                del = scale_linear(del, graph_width, max_change);
2841                                add = total - del;
2842                        }
2843                }
2844                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2845                strbuf_addf(&out, " %*"PRIuMAX"%s",
2846                        number_width, added + deleted,
2847                        added + deleted ? " " : "");
2848                show_graph(&out, '+', add, add_c, reset);
2849                show_graph(&out, '-', del, del_c, reset);
2850                strbuf_addch(&out, '\n');
2851                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2852                                 out.buf, out.len, 0);
2853                strbuf_reset(&out);
2854        }
2855
2856        for (i = 0; i < data->nr; i++) {
2857                struct diffstat_file *file = data->files[i];
2858                uintmax_t added = file->added;
2859                uintmax_t deleted = file->deleted;
2860
2861                if (file->is_unmerged ||
2862                    (!file->is_interesting && (added + deleted == 0))) {
2863                        total_files--;
2864                        continue;
2865                }
2866
2867                if (!file->is_binary) {
2868                        adds += added;
2869                        dels += deleted;
2870                }
2871                if (i < count)
2872                        continue;
2873                if (!extra_shown)
2874                        emit_diff_symbol(options,
2875                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2876                                         NULL, 0, 0);
2877                extra_shown = 1;
2878        }
2879
2880        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2881        strbuf_release(&out);
2882}
2883
2884static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2885{
2886        int i, adds = 0, dels = 0, total_files = data->nr;
2887
2888        if (data->nr == 0)
2889                return;
2890
2891        for (i = 0; i < data->nr; i++) {
2892                int added = data->files[i]->added;
2893                int deleted = data->files[i]->deleted;
2894
2895                if (data->files[i]->is_unmerged ||
2896                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2897                        total_files--;
2898                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2899                        adds += added;
2900                        dels += deleted;
2901                }
2902        }
2903        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2904}
2905
2906static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2907{
2908        int i;
2909
2910        if (data->nr == 0)
2911                return;
2912
2913        for (i = 0; i < data->nr; i++) {
2914                struct diffstat_file *file = data->files[i];
2915
2916                fprintf(options->file, "%s", diff_line_prefix(options));
2917
2918                if (file->is_binary)
2919                        fprintf(options->file, "-\t-\t");
2920                else
2921                        fprintf(options->file,
2922                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2923                                file->added, file->deleted);
2924                if (options->line_termination) {
2925                        fill_print_name(file);
2926                        if (!file->is_renamed)
2927                                write_name_quoted(file->name, options->file,
2928                                                  options->line_termination);
2929                        else {
2930                                fputs(file->print_name, options->file);
2931                                putc(options->line_termination, options->file);
2932                        }
2933                } else {
2934                        if (file->is_renamed) {
2935                                putc('\0', options->file);
2936                                write_name_quoted(file->from_name, options->file, '\0');
2937                        }
2938                        write_name_quoted(file->name, options->file, '\0');
2939                }
2940        }
2941}
2942
2943struct dirstat_file {
2944        const char *name;
2945        unsigned long changed;
2946};
2947
2948struct dirstat_dir {
2949        struct dirstat_file *files;
2950        int alloc, nr, permille, cumulative;
2951};
2952
2953static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2954                unsigned long changed, const char *base, int baselen)
2955{
2956        unsigned long sum_changes = 0;
2957        unsigned int sources = 0;
2958        const char *line_prefix = diff_line_prefix(opt);
2959
2960        while (dir->nr) {
2961                struct dirstat_file *f = dir->files;
2962                int namelen = strlen(f->name);
2963                unsigned long changes;
2964                char *slash;
2965
2966                if (namelen < baselen)
2967                        break;
2968                if (memcmp(f->name, base, baselen))
2969                        break;
2970                slash = strchr(f->name + baselen, '/');
2971                if (slash) {
2972                        int newbaselen = slash + 1 - f->name;
2973                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2974                        sources++;
2975                } else {
2976                        changes = f->changed;
2977                        dir->files++;
2978                        dir->nr--;
2979                        sources += 2;
2980                }
2981                sum_changes += changes;
2982        }
2983
2984        /*
2985         * We don't report dirstat's for
2986         *  - the top level
2987         *  - or cases where everything came from a single directory
2988         *    under this directory (sources == 1).
2989         */
2990        if (baselen && sources != 1) {
2991                if (sum_changes) {
2992                        int permille = sum_changes * 1000 / changed;
2993                        if (permille >= dir->permille) {
2994                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2995                                        permille / 10, permille % 10, baselen, base);
2996                                if (!dir->cumulative)
2997                                        return 0;
2998                        }
2999                }
3000        }
3001        return sum_changes;
3002}
3003
3004static int dirstat_compare(const void *_a, const void *_b)
3005{
3006        const struct dirstat_file *a = _a;
3007        const struct dirstat_file *b = _b;
3008        return strcmp(a->name, b->name);
3009}
3010
3011static void show_dirstat(struct diff_options *options)
3012{
3013        int i;
3014        unsigned long changed;
3015        struct dirstat_dir dir;
3016        struct diff_queue_struct *q = &diff_queued_diff;
3017
3018        dir.files = NULL;
3019        dir.alloc = 0;
3020        dir.nr = 0;
3021        dir.permille = options->dirstat_permille;
3022        dir.cumulative = options->flags.dirstat_cumulative;
3023
3024        changed = 0;
3025        for (i = 0; i < q->nr; i++) {
3026                struct diff_filepair *p = q->queue[i];
3027                const char *name;
3028                unsigned long copied, added, damage;
3029
3030                name = p->two->path ? p->two->path : p->one->path;
3031
3032                if (p->one->oid_valid && p->two->oid_valid &&
3033                    oideq(&p->one->oid, &p->two->oid)) {
3034                        /*
3035                         * The SHA1 has not changed, so pre-/post-content is
3036                         * identical. We can therefore skip looking at the
3037                         * file contents altogether.
3038                         */
3039                        damage = 0;
3040                        goto found_damage;
3041                }
3042
3043                if (options->flags.dirstat_by_file) {
3044                        /*
3045                         * In --dirstat-by-file mode, we don't really need to
3046                         * look at the actual file contents at all.
3047                         * The fact that the SHA1 changed is enough for us to
3048                         * add this file to the list of results
3049                         * (with each file contributing equal damage).
3050                         */
3051                        damage = 1;
3052                        goto found_damage;
3053                }
3054
3055                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
3056                        diff_populate_filespec(options->repo, p->one, 0);
3057                        diff_populate_filespec(options->repo, p->two, 0);
3058                        diffcore_count_changes(options->repo,
3059                                               p->one, p->two, NULL, NULL,
3060                                               &copied, &added);
3061                        diff_free_filespec_data(p->one);
3062                        diff_free_filespec_data(p->two);
3063                } else if (DIFF_FILE_VALID(p->one)) {
3064                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3065                        copied = added = 0;
3066                        diff_free_filespec_data(p->one);
3067                } else if (DIFF_FILE_VALID(p->two)) {
3068                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3069                        copied = 0;
3070                        added = p->two->size;
3071                        diff_free_filespec_data(p->two);
3072                } else
3073                        continue;
3074
3075                /*
3076                 * Original minus copied is the removed material,
3077                 * added is the new material.  They are both damages
3078                 * made to the preimage.
3079                 * If the resulting damage is zero, we know that
3080                 * diffcore_count_changes() considers the two entries to
3081                 * be identical, but since the oid changed, we
3082                 * know that there must have been _some_ kind of change,
3083                 * so we force all entries to have damage > 0.
3084                 */
3085                damage = (p->one->size - copied) + added;
3086                if (!damage)
3087                        damage = 1;
3088
3089found_damage:
3090                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3091                dir.files[dir.nr].name = name;
3092                dir.files[dir.nr].changed = damage;
3093                changed += damage;
3094                dir.nr++;
3095        }
3096
3097        /* This can happen even with many files, if everything was renames */
3098        if (!changed)
3099                return;
3100
3101        /* Show all directories with more than x% of the changes */
3102        QSORT(dir.files, dir.nr, dirstat_compare);
3103        gather_dirstat(options, &dir, changed, "", 0);
3104}
3105
3106static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3107{
3108        int i;
3109        unsigned long changed;
3110        struct dirstat_dir dir;
3111
3112        if (data->nr == 0)
3113                return;
3114
3115        dir.files = NULL;
3116        dir.alloc = 0;
3117        dir.nr = 0;
3118        dir.permille = options->dirstat_permille;
3119        dir.cumulative = options->flags.dirstat_cumulative;
3120
3121        changed = 0;
3122        for (i = 0; i < data->nr; i++) {
3123                struct diffstat_file *file = data->files[i];
3124                unsigned long damage = file->added + file->deleted;
3125                if (file->is_binary)
3126                        /*
3127                         * binary files counts bytes, not lines. Must find some
3128                         * way to normalize binary bytes vs. textual lines.
3129                         * The following heuristic assumes that there are 64
3130                         * bytes per "line".
3131                         * This is stupid and ugly, but very cheap...
3132                         */
3133                        damage = DIV_ROUND_UP(damage, 64);
3134                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3135                dir.files[dir.nr].name = file->name;
3136                dir.files[dir.nr].changed = damage;
3137                changed += damage;
3138                dir.nr++;
3139        }
3140
3141        /* This can happen even with many files, if everything was renames */
3142        if (!changed)
3143                return;
3144
3145        /* Show all directories with more than x% of the changes */
3146        QSORT(dir.files, dir.nr, dirstat_compare);
3147        gather_dirstat(options, &dir, changed, "", 0);
3148}
3149
3150static void free_diffstat_info(struct diffstat_t *diffstat)
3151{
3152        int i;
3153        for (i = 0; i < diffstat->nr; i++) {
3154                struct diffstat_file *f = diffstat->files[i];
3155                free(f->print_name);
3156                free(f->name);
3157                free(f->from_name);
3158                free(f);
3159        }
3160        free(diffstat->files);
3161}
3162
3163struct checkdiff_t {
3164        const char *filename;
3165        int lineno;
3166        int conflict_marker_size;
3167        struct diff_options *o;
3168        unsigned ws_rule;
3169        unsigned status;
3170};
3171
3172static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3173{
3174        char firstchar;
3175        int cnt;
3176
3177        if (len < marker_size + 1)
3178                return 0;
3179        firstchar = line[0];
3180        switch (firstchar) {
3181        case '=': case '>': case '<': case '|':
3182                break;
3183        default:
3184                return 0;
3185        }
3186        for (cnt = 1; cnt < marker_size; cnt++)
3187                if (line[cnt] != firstchar)
3188                        return 0;
3189        /* line[1] thru line[marker_size-1] are same as firstchar */
3190        if (len < marker_size + 1 || !isspace(line[marker_size]))
3191                return 0;
3192        return 1;
3193}
3194
3195static void checkdiff_consume_hunk(void *priv,
3196                                   long ob, long on, long nb, long nn,
3197                                   const char *func, long funclen)
3198
3199{
3200        struct checkdiff_t *data = priv;
3201        data->lineno = nb - 1;
3202}
3203
3204static void checkdiff_consume(void *priv, char *line, unsigned long len)
3205{
3206        struct checkdiff_t *data = priv;
3207        int marker_size = data->conflict_marker_size;
3208        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3209        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3210        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3211        char *err;
3212        const char *line_prefix;
3213
3214        assert(data->o);
3215        line_prefix = diff_line_prefix(data->o);
3216
3217        if (line[0] == '+') {
3218                unsigned bad;
3219                data->lineno++;
3220                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3221                        data->status |= 1;
3222                        fprintf(data->o->file,
3223                                "%s%s:%d: leftover conflict marker\n",
3224                                line_prefix, data->filename, data->lineno);
3225                }
3226                bad = ws_check(line + 1, len - 1, data->ws_rule);
3227                if (!bad)
3228                        return;
3229                data->status |= bad;
3230                err = whitespace_error_string(bad);
3231                fprintf(data->o->file, "%s%s:%d: %s.\n",
3232                        line_prefix, data->filename, data->lineno, err);
3233                free(err);
3234                emit_line(data->o, set, reset, line, 1);
3235                ws_check_emit(line + 1, len - 1, data->ws_rule,
3236                              data->o->file, set, reset, ws);
3237        } else if (line[0] == ' ') {
3238                data->lineno++;
3239        }
3240}
3241
3242static unsigned char *deflate_it(char *data,
3243                                 unsigned long size,
3244                                 unsigned long *result_size)
3245{
3246        int bound;
3247        unsigned char *deflated;
3248        git_zstream stream;
3249
3250        git_deflate_init(&stream, zlib_compression_level);
3251        bound = git_deflate_bound(&stream, size);
3252        deflated = xmalloc(bound);
3253        stream.next_out = deflated;
3254        stream.avail_out = bound;
3255
3256        stream.next_in = (unsigned char *)data;
3257        stream.avail_in = size;
3258        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3259                ; /* nothing */
3260        git_deflate_end(&stream);
3261        *result_size = stream.total_out;
3262        return deflated;
3263}
3264
3265static void emit_binary_diff_body(struct diff_options *o,
3266                                  mmfile_t *one, mmfile_t *two)
3267{
3268        void *cp;
3269        void *delta;
3270        void *deflated;
3271        void *data;
3272        unsigned long orig_size;
3273        unsigned long delta_size;
3274        unsigned long deflate_size;
3275        unsigned long data_size;
3276
3277        /* We could do deflated delta, or we could do just deflated two,
3278         * whichever is smaller.
3279         */
3280        delta = NULL;
3281        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3282        if (one->size && two->size) {
3283                delta = diff_delta(one->ptr, one->size,
3284                                   two->ptr, two->size,
3285                                   &delta_size, deflate_size);
3286                if (delta) {
3287                        void *to_free = delta;
3288                        orig_size = delta_size;
3289                        delta = deflate_it(delta, delta_size, &delta_size);
3290                        free(to_free);
3291                }
3292        }
3293
3294        if (delta && delta_size < deflate_size) {
3295                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3296                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3297                                 s, strlen(s), 0);
3298                free(s);
3299                free(deflated);
3300                data = delta;
3301                data_size = delta_size;
3302        } else {
3303                char *s = xstrfmt("%lu", two->size);
3304                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3305                                 s, strlen(s), 0);
3306                free(s);
3307                free(delta);
3308                data = deflated;
3309                data_size = deflate_size;
3310        }
3311
3312        /* emit data encoded in base85 */
3313        cp = data;
3314        while (data_size) {
3315                int len;
3316                int bytes = (52 < data_size) ? 52 : data_size;
3317                char line[71];
3318                data_size -= bytes;
3319                if (bytes <= 26)
3320                        line[0] = bytes + 'A' - 1;
3321                else
3322                        line[0] = bytes - 26 + 'a' - 1;
3323                encode_85(line + 1, cp, bytes);
3324                cp = (char *) cp + bytes;
3325
3326                len = strlen(line);
3327                line[len++] = '\n';
3328                line[len] = '\0';
3329
3330                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3331                                 line, len, 0);
3332        }
3333        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3334        free(data);
3335}
3336
3337static void emit_binary_diff(struct diff_options *o,
3338                             mmfile_t *one, mmfile_t *two)
3339{
3340        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3341        emit_binary_diff_body(o, one, two);
3342        emit_binary_diff_body(o, two, one);
3343}
3344
3345int diff_filespec_is_binary(struct repository *r,
3346                            struct diff_filespec *one)
3347{
3348        if (one->is_binary == -1) {
3349                diff_filespec_load_driver(one, r->index);
3350                if (one->driver->binary != -1)
3351                        one->is_binary = one->driver->binary;
3352                else {
3353                        if (!one->data && DIFF_FILE_VALID(one))
3354                                diff_populate_filespec(r, one, CHECK_BINARY);
3355                        if (one->is_binary == -1 && one->data)
3356                                one->is_binary = buffer_is_binary(one->data,
3357                                                one->size);
3358                        if (one->is_binary == -1)
3359                                one->is_binary = 0;
3360                }
3361        }
3362        return one->is_binary;
3363}
3364
3365static const struct userdiff_funcname *
3366diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3367{
3368        diff_filespec_load_driver(one, o->repo->index);
3369        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3370}
3371
3372void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3373{
3374        if (!options->a_prefix)
3375                options->a_prefix = a;
3376        if (!options->b_prefix)
3377                options->b_prefix = b;
3378}
3379
3380struct userdiff_driver *get_textconv(struct repository *r,
3381                                     struct diff_filespec *one)
3382{
3383        if (!DIFF_FILE_VALID(one))
3384                return NULL;
3385
3386        diff_filespec_load_driver(one, r->index);
3387        return userdiff_get_textconv(r, one->driver);
3388}
3389
3390static void builtin_diff(const char *name_a,
3391                         const char *name_b,
3392                         struct diff_filespec *one,
3393                         struct diff_filespec *two,
3394                         const char *xfrm_msg,
3395                         int must_show_header,
3396                         struct diff_options *o,
3397                         int complete_rewrite)
3398{
3399        mmfile_t mf1, mf2;
3400        const char *lbl[2];
3401        char *a_one, *b_two;
3402        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3403        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3404        const char *a_prefix, *b_prefix;
3405        struct userdiff_driver *textconv_one = NULL;
3406        struct userdiff_driver *textconv_two = NULL;
3407        struct strbuf header = STRBUF_INIT;
3408        const char *line_prefix = diff_line_prefix(o);
3409
3410        diff_set_mnemonic_prefix(o, "a/", "b/");
3411        if (o->flags.reverse_diff) {
3412                a_prefix = o->b_prefix;
3413                b_prefix = o->a_prefix;
3414        } else {
3415                a_prefix = o->a_prefix;
3416                b_prefix = o->b_prefix;
3417        }
3418
3419        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3420            (!one->mode || S_ISGITLINK(one->mode)) &&
3421            (!two->mode || S_ISGITLINK(two->mode))) {
3422                show_submodule_summary(o, one->path ? one->path : two->path,
3423                                &one->oid, &two->oid,
3424                                two->dirty_submodule);
3425                return;
3426        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3427                   (!one->mode || S_ISGITLINK(one->mode)) &&
3428                   (!two->mode || S_ISGITLINK(two->mode))) {
3429                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3430                                &one->oid, &two->oid,
3431                                two->dirty_submodule);
3432                return;
3433        }
3434
3435        if (o->flags.allow_textconv) {
3436                textconv_one = get_textconv(o->repo, one);
3437                textconv_two = get_textconv(o->repo, two);
3438        }
3439
3440        /* Never use a non-valid filename anywhere if at all possible */
3441        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3442        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3443
3444        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3445        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3446        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3447        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3448        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3449        if (lbl[0][0] == '/') {
3450                /* /dev/null */
3451                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3452                if (xfrm_msg)
3453                        strbuf_addstr(&header, xfrm_msg);
3454                must_show_header = 1;
3455        }
3456        else if (lbl[1][0] == '/') {
3457                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3458                if (xfrm_msg)
3459                        strbuf_addstr(&header, xfrm_msg);
3460                must_show_header = 1;
3461        }
3462        else {
3463                if (one->mode != two->mode) {
3464                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3465                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3466                        must_show_header = 1;
3467                }
3468                if (xfrm_msg)
3469                        strbuf_addstr(&header, xfrm_msg);
3470
3471                /*
3472                 * we do not run diff between different kind
3473                 * of objects.
3474                 */
3475                if ((one->mode ^ two->mode) & S_IFMT)
3476                        goto free_ab_and_return;
3477                if (complete_rewrite &&
3478                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3479                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3480                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3481                                         header.buf, header.len, 0);
3482                        strbuf_reset(&header);
3483                        emit_rewrite_diff(name_a, name_b, one, two,
3484                                          textconv_one, textconv_two, o);
3485                        o->found_changes = 1;
3486                        goto free_ab_and_return;
3487                }
3488        }
3489
3490        if (o->irreversible_delete && lbl[1][0] == '/') {
3491                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3492                                 header.len, 0);
3493                strbuf_reset(&header);
3494                goto free_ab_and_return;
3495        } else if (!o->flags.text &&
3496                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3497                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3498                struct strbuf sb = STRBUF_INIT;
3499                if (!one->data && !two->data &&
3500                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3501                    !o->flags.binary) {
3502                        if (oideq(&one->oid, &two->oid)) {
3503                                if (must_show_header)
3504                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3505                                                         header.buf, header.len,
3506                                                         0);
3507                                goto free_ab_and_return;
3508                        }
3509                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3510                                         header.buf, header.len, 0);
3511                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3512                                    diff_line_prefix(o), lbl[0], lbl[1]);
3513                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3514                                         sb.buf, sb.len, 0);
3515                        strbuf_release(&sb);
3516                        goto free_ab_and_return;
3517                }
3518                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3519                    fill_mmfile(o->repo, &mf2, two) < 0)
3520                        die("unable to read files to diff");
3521                /* Quite common confusing case */
3522                if (mf1.size == mf2.size &&
3523                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3524                        if (must_show_header)
3525                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3526                                                 header.buf, header.len, 0);
3527                        goto free_ab_and_return;
3528                }
3529                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3530                strbuf_reset(&header);
3531                if (o->flags.binary)
3532                        emit_binary_diff(o, &mf1, &mf2);
3533                else {
3534                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3535                                    diff_line_prefix(o), lbl[0], lbl[1]);
3536                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3537                                         sb.buf, sb.len, 0);
3538                        strbuf_release(&sb);
3539                }
3540                o->found_changes = 1;
3541        } else {
3542                /* Crazy xdl interfaces.. */
3543                const char *diffopts;
3544                const char *v;
3545                xpparam_t xpp;
3546                xdemitconf_t xecfg;
3547                struct emit_callback ecbdata;
3548                const struct userdiff_funcname *pe;
3549
3550                if (must_show_header) {
3551                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3552                                         header.buf, header.len, 0);
3553                        strbuf_reset(&header);
3554                }
3555
3556                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3557                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3558
3559                pe = diff_funcname_pattern(o, one);
3560                if (!pe)
3561                        pe = diff_funcname_pattern(o, two);
3562
3563                memset(&xpp, 0, sizeof(xpp));
3564                memset(&xecfg, 0, sizeof(xecfg));
3565                memset(&ecbdata, 0, sizeof(ecbdata));
3566                if (o->flags.suppress_diff_headers)
3567                        lbl[0] = NULL;
3568                ecbdata.label_path = lbl;
3569                ecbdata.color_diff = want_color(o->use_color);
3570                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3571                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3572                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3573                ecbdata.opt = o;
3574                if (header.len && !o->flags.suppress_diff_headers)
3575                        ecbdata.header = &header;
3576                xpp.flags = o->xdl_opts;
3577                xpp.anchors = o->anchors;
3578                xpp.anchors_nr = o->anchors_nr;
3579                xecfg.ctxlen = o->context;
3580                xecfg.interhunkctxlen = o->interhunkcontext;
3581                xecfg.flags = XDL_EMIT_FUNCNAMES;
3582                if (o->flags.funccontext)
3583                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3584                if (pe)
3585                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3586
3587                diffopts = getenv("GIT_DIFF_OPTS");
3588                if (!diffopts)
3589                        ;
3590                else if (skip_prefix(diffopts, "--unified=", &v))
3591                        xecfg.ctxlen = strtoul(v, NULL, 10);
3592                else if (skip_prefix(diffopts, "-u", &v))
3593                        xecfg.ctxlen = strtoul(v, NULL, 10);
3594
3595                if (o->word_diff)
3596                        init_diff_words_data(&ecbdata, o, one, two);
3597                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3598                                  &ecbdata, &xpp, &xecfg))
3599                        die("unable to generate diff for %s", one->path);
3600                if (o->word_diff)
3601                        free_diff_words_data(&ecbdata);
3602                if (textconv_one)
3603                        free(mf1.ptr);
3604                if (textconv_two)
3605                        free(mf2.ptr);
3606                xdiff_clear_find_func(&xecfg);
3607        }
3608
3609 free_ab_and_return:
3610        strbuf_release(&header);
3611        diff_free_filespec_data(one);
3612        diff_free_filespec_data(two);
3613        free(a_one);
3614        free(b_two);
3615        return;
3616}
3617
3618static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3619{
3620        if (!is_renamed) {
3621                if (p->status == DIFF_STATUS_ADDED) {
3622                        if (S_ISLNK(p->two->mode))
3623                                return "new +l";
3624                        else if ((p->two->mode & 0777) == 0755)
3625                                return "new +x";
3626                        else
3627                                return "new";
3628                } else if (p->status == DIFF_STATUS_DELETED)
3629                        return "gone";
3630        }
3631        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3632                return "mode -l";
3633        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3634                return "mode +l";
3635        else if ((p->one->mode & 0777) == 0644 &&
3636                 (p->two->mode & 0777) == 0755)
3637                return "mode +x";
3638        else if ((p->one->mode & 0777) == 0755 &&
3639                 (p->two->mode & 0777) == 0644)
3640                return "mode -x";
3641        return NULL;
3642}
3643
3644static void builtin_diffstat(const char *name_a, const char *name_b,
3645                             struct diff_filespec *one,
3646                             struct diff_filespec *two,
3647                             struct diffstat_t *diffstat,
3648                             struct diff_options *o,
3649                             struct diff_filepair *p)
3650{
3651        mmfile_t mf1, mf2;
3652        struct diffstat_file *data;
3653        int same_contents;
3654        int complete_rewrite = 0;
3655
3656        if (!DIFF_PAIR_UNMERGED(p)) {
3657                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3658                        complete_rewrite = 1;
3659        }
3660
3661        data = diffstat_add(diffstat, name_a, name_b);
3662        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3663        if (o->flags.stat_with_summary)
3664                data->comments = get_compact_summary(p, data->is_renamed);
3665
3666        if (!one || !two) {
3667                data->is_unmerged = 1;
3668                return;
3669        }
3670
3671        same_contents = oideq(&one->oid, &two->oid);
3672
3673        if (diff_filespec_is_binary(o->repo, one) ||
3674            diff_filespec_is_binary(o->repo, two)) {
3675                data->is_binary = 1;
3676                if (same_contents) {
3677                        data->added = 0;
3678                        data->deleted = 0;
3679                } else {
3680                        data->added = diff_filespec_size(o->repo, two);
3681                        data->deleted = diff_filespec_size(o->repo, one);
3682                }
3683        }
3684
3685        else if (complete_rewrite) {
3686                diff_populate_filespec(o->repo, one, 0);
3687                diff_populate_filespec(o->repo, two, 0);
3688                data->deleted = count_lines(one->data, one->size);
3689                data->added = count_lines(two->data, two->size);
3690        }
3691
3692        else if (!same_contents) {
3693                /* Crazy xdl interfaces.. */
3694                xpparam_t xpp;
3695                xdemitconf_t xecfg;
3696
3697                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3698                    fill_mmfile(o->repo, &mf2, two) < 0)
3699                        die("unable to read files to diff");
3700
3701                memset(&xpp, 0, sizeof(xpp));
3702                memset(&xecfg, 0, sizeof(xecfg));
3703                xpp.flags = o->xdl_opts;
3704                xpp.anchors = o->anchors;
3705                xpp.anchors_nr = o->anchors_nr;
3706                xecfg.ctxlen = o->context;
3707                xecfg.interhunkctxlen = o->interhunkcontext;
3708                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3709                                  diffstat_consume, diffstat, &xpp, &xecfg))
3710                        die("unable to generate diffstat for %s", one->path);
3711        }
3712
3713        diff_free_filespec_data(one);
3714        diff_free_filespec_data(two);
3715}
3716
3717static void builtin_checkdiff(const char *name_a, const char *name_b,
3718                              const char *attr_path,
3719                              struct diff_filespec *one,
3720                              struct diff_filespec *two,
3721                              struct diff_options *o)
3722{
3723        mmfile_t mf1, mf2;
3724        struct checkdiff_t data;
3725
3726        if (!two)
3727                return;
3728
3729        memset(&data, 0, sizeof(data));
3730        data.filename = name_b ? name_b : name_a;
3731        data.lineno = 0;
3732        data.o = o;
3733        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3734        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3735
3736        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3737            fill_mmfile(o->repo, &mf2, two) < 0)
3738                die("unable to read files to diff");
3739
3740        /*
3741         * All the other codepaths check both sides, but not checking
3742         * the "old" side here is deliberate.  We are checking the newly
3743         * introduced changes, and as long as the "new" side is text, we
3744         * can and should check what it introduces.
3745         */
3746        if (diff_filespec_is_binary(o->repo, two))
3747                goto free_and_return;
3748        else {
3749                /* Crazy xdl interfaces.. */
3750                xpparam_t xpp;
3751                xdemitconf_t xecfg;
3752
3753                memset(&xpp, 0, sizeof(xpp));
3754                memset(&xecfg, 0, sizeof(xecfg));
3755                xecfg.ctxlen = 1; /* at least one context line */
3756                xpp.flags = 0;
3757                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3758                                  checkdiff_consume, &data,
3759                                  &xpp, &xecfg))
3760                        die("unable to generate checkdiff for %s", one->path);
3761
3762                if (data.ws_rule & WS_BLANK_AT_EOF) {
3763                        struct emit_callback ecbdata;
3764                        int blank_at_eof;
3765
3766                        ecbdata.ws_rule = data.ws_rule;
3767                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3768                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3769
3770                        if (blank_at_eof) {
3771                                static char *err;
3772                                if (!err)
3773                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3774                                fprintf(o->file, "%s:%d: %s.\n",
3775                                        data.filename, blank_at_eof, err);
3776                                data.status = 1; /* report errors */
3777                        }
3778                }
3779        }
3780 free_and_return:
3781        diff_free_filespec_data(one);
3782        diff_free_filespec_data(two);
3783        if (data.status)
3784                o->flags.check_failed = 1;
3785}
3786
3787struct diff_filespec *alloc_filespec(const char *path)
3788{
3789        struct diff_filespec *spec;
3790
3791        FLEXPTR_ALLOC_STR(spec, path, path);
3792        spec->count = 1;
3793        spec->is_binary = -1;
3794        return spec;
3795}
3796
3797void free_filespec(struct diff_filespec *spec)
3798{
3799        if (!--spec->count) {
3800                diff_free_filespec_data(spec);
3801                free(spec);
3802        }
3803}
3804
3805void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3806                   int oid_valid, unsigned short mode)
3807{
3808        if (mode) {
3809                spec->mode = canon_mode(mode);
3810                oidcpy(&spec->oid, oid);
3811                spec->oid_valid = oid_valid;
3812        }
3813}
3814
3815/*
3816 * Given a name and sha1 pair, if the index tells us the file in
3817 * the work tree has that object contents, return true, so that
3818 * prepare_temp_file() does not have to inflate and extract.
3819 */
3820static int reuse_worktree_file(struct index_state *istate,
3821                               const char *name,
3822                               const struct object_id *oid,
3823                               int want_file)
3824{
3825        const struct cache_entry *ce;
3826        struct stat st;
3827        int pos, len;
3828
3829        /*
3830         * We do not read the cache ourselves here, because the
3831         * benchmark with my previous version that always reads cache
3832         * shows that it makes things worse for diff-tree comparing
3833         * two linux-2.6 kernel trees in an already checked out work
3834         * tree.  This is because most diff-tree comparisons deal with
3835         * only a small number of files, while reading the cache is
3836         * expensive for a large project, and its cost outweighs the
3837         * savings we get by not inflating the object to a temporary
3838         * file.  Practically, this code only helps when we are used
3839         * by diff-cache --cached, which does read the cache before
3840         * calling us.
3841         */
3842        if (!istate->cache)
3843                return 0;
3844
3845        /* We want to avoid the working directory if our caller
3846         * doesn't need the data in a normal file, this system
3847         * is rather slow with its stat/open/mmap/close syscalls,
3848         * and the object is contained in a pack file.  The pack
3849         * is probably already open and will be faster to obtain
3850         * the data through than the working directory.  Loose
3851         * objects however would tend to be slower as they need
3852         * to be individually opened and inflated.
3853         */
3854        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3855                return 0;
3856
3857        /*
3858         * Similarly, if we'd have to convert the file contents anyway, that
3859         * makes the optimization not worthwhile.
3860         */
3861        if (!want_file && would_convert_to_git(istate, name))
3862                return 0;
3863
3864        len = strlen(name);
3865        pos = index_name_pos(istate, name, len);
3866        if (pos < 0)
3867                return 0;
3868        ce = istate->cache[pos];
3869
3870        /*
3871         * This is not the sha1 we are looking for, or
3872         * unreusable because it is not a regular file.
3873         */
3874        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3875                return 0;
3876
3877        /*
3878         * If ce is marked as "assume unchanged", there is no
3879         * guarantee that work tree matches what we are looking for.
3880         */
3881        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3882                return 0;
3883
3884        /*
3885         * If ce matches the file in the work tree, we can reuse it.
3886         */
3887        if (ce_uptodate(ce) ||
3888            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3889                return 1;
3890
3891        return 0;
3892}
3893
3894static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3895{
3896        struct strbuf buf = STRBUF_INIT;
3897        char *dirty = "";
3898
3899        /* Are we looking at the work tree? */
3900        if (s->dirty_submodule)
3901                dirty = "-dirty";
3902
3903        strbuf_addf(&buf, "Subproject commit %s%s\n",
3904                    oid_to_hex(&s->oid), dirty);
3905        s->size = buf.len;
3906        if (size_only) {
3907                s->data = NULL;
3908                strbuf_release(&buf);
3909        } else {
3910                s->data = strbuf_detach(&buf, NULL);
3911                s->should_free = 1;
3912        }
3913        return 0;
3914}
3915
3916/*
3917 * While doing rename detection and pickaxe operation, we may need to
3918 * grab the data for the blob (or file) for our own in-core comparison.
3919 * diff_filespec has data and size fields for this purpose.
3920 */
3921int diff_populate_filespec(struct repository *r,
3922                           struct diff_filespec *s,
3923                           unsigned int flags)
3924{
3925        int size_only = flags & CHECK_SIZE_ONLY;
3926        int err = 0;
3927        int conv_flags = global_conv_flags_eol;
3928        /*
3929         * demote FAIL to WARN to allow inspecting the situation
3930         * instead of refusing.
3931         */
3932        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3933                conv_flags = CONV_EOL_RNDTRP_WARN;
3934
3935        if (!DIFF_FILE_VALID(s))
3936                die("internal error: asking to populate invalid file.");
3937        if (S_ISDIR(s->mode))
3938                return -1;
3939
3940        if (s->data)
3941                return 0;
3942
3943        if (size_only && 0 < s->size)
3944                return 0;
3945
3946        if (S_ISGITLINK(s->mode))
3947                return diff_populate_gitlink(s, size_only);
3948
3949        if (!s->oid_valid ||
3950            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3951                struct strbuf buf = STRBUF_INIT;
3952                struct stat st;
3953                int fd;
3954
3955                if (lstat(s->path, &st) < 0) {
3956                err_empty:
3957                        err = -1;
3958                empty:
3959                        s->data = (char *)"";
3960                        s->size = 0;
3961                        return err;
3962                }
3963                s->size = xsize_t(st.st_size);
3964                if (!s->size)
3965                        goto empty;
3966                if (S_ISLNK(st.st_mode)) {
3967                        struct strbuf sb = STRBUF_INIT;
3968
3969                        if (strbuf_readlink(&sb, s->path, s->size))
3970                                goto err_empty;
3971                        s->size = sb.len;
3972                        s->data = strbuf_detach(&sb, NULL);
3973                        s->should_free = 1;
3974                        return 0;
3975                }
3976
3977                /*
3978                 * Even if the caller would be happy with getting
3979                 * only the size, we cannot return early at this
3980                 * point if the path requires us to run the content
3981                 * conversion.
3982                 */
3983                if (size_only && !would_convert_to_git(r->index, s->path))
3984                        return 0;
3985
3986                /*
3987                 * Note: this check uses xsize_t(st.st_size) that may
3988                 * not be the true size of the blob after it goes
3989                 * through convert_to_git().  This may not strictly be
3990                 * correct, but the whole point of big_file_threshold
3991                 * and is_binary check being that we want to avoid
3992                 * opening the file and inspecting the contents, this
3993                 * is probably fine.
3994                 */
3995                if ((flags & CHECK_BINARY) &&
3996                    s->size > big_file_threshold && s->is_binary == -1) {
3997                        s->is_binary = 1;
3998                        return 0;
3999                }
4000                fd = open(s->path, O_RDONLY);
4001                if (fd < 0)
4002                        goto err_empty;
4003                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
4004                close(fd);
4005                s->should_munmap = 1;
4006
4007                /*
4008                 * Convert from working tree format to canonical git format
4009                 */
4010                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
4011                        size_t size = 0;
4012                        munmap(s->data, s->size);
4013                        s->should_munmap = 0;
4014                        s->data = strbuf_detach(&buf, &size);
4015                        s->size = size;
4016                        s->should_free = 1;
4017                }
4018        }
4019        else {
4020                enum object_type type;
4021                if (size_only || (flags & CHECK_BINARY)) {
4022                        type = oid_object_info(r, &s->oid, &s->size);
4023                        if (type < 0)
4024                                die("unable to read %s",
4025                                    oid_to_hex(&s->oid));
4026                        if (size_only)
4027                                return 0;
4028                        if (s->size > big_file_threshold && s->is_binary == -1) {
4029                                s->is_binary = 1;
4030                                return 0;
4031                        }
4032                }
4033                s->data = read_object_file(&s->oid, &type, &s->size);
4034                if (!s->data)
4035                        die("unable to read %s", oid_to_hex(&s->oid));
4036                s->should_free = 1;
4037        }
4038        return 0;
4039}
4040
4041void diff_free_filespec_blob(struct diff_filespec *s)
4042{
4043        if (s->should_free)
4044                free(s->data);
4045        else if (s->should_munmap)
4046                munmap(s->data, s->size);
4047
4048        if (s->should_free || s->should_munmap) {
4049                s->should_free = s->should_munmap = 0;
4050                s->data = NULL;
4051        }
4052}
4053
4054void diff_free_filespec_data(struct diff_filespec *s)
4055{
4056        diff_free_filespec_blob(s);
4057        FREE_AND_NULL(s->cnt_data);
4058}
4059
4060static void prep_temp_blob(struct index_state *istate,
4061                           const char *path, struct diff_tempfile *temp,
4062                           void *blob,
4063                           unsigned long size,
4064                           const struct object_id *oid,
4065                           int mode)
4066{
4067        struct strbuf buf = STRBUF_INIT;
4068        struct strbuf tempfile = STRBUF_INIT;
4069        char *path_dup = xstrdup(path);
4070        const char *base = basename(path_dup);
4071
4072        /* Generate "XXXXXX_basename.ext" */
4073        strbuf_addstr(&tempfile, "XXXXXX_");
4074        strbuf_addstr(&tempfile, base);
4075
4076        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4077        if (!temp->tempfile)
4078                die_errno("unable to create temp-file");
4079        if (convert_to_working_tree(istate, path,
4080                        (const char *)blob, (size_t)size, &buf)) {
4081                blob = buf.buf;
4082                size = buf.len;
4083        }
4084        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4085            close_tempfile_gently(temp->tempfile))
4086                die_errno("unable to write temp-file");
4087        temp->name = get_tempfile_path(temp->tempfile);
4088        oid_to_hex_r(temp->hex, oid);
4089        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4090        strbuf_release(&buf);
4091        strbuf_release(&tempfile);
4092        free(path_dup);
4093}
4094
4095static struct diff_tempfile *prepare_temp_file(struct repository *r,
4096                                               const char *name,
4097                                               struct diff_filespec *one)
4098{
4099        struct diff_tempfile *temp = claim_diff_tempfile();
4100
4101        if (!DIFF_FILE_VALID(one)) {
4102        not_a_valid_file:
4103                /* A '-' entry produces this for file-2, and
4104                 * a '+' entry produces this for file-1.
4105                 */
4106                temp->name = "/dev/null";
4107                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4108                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4109                return temp;
4110        }
4111
4112        if (!S_ISGITLINK(one->mode) &&
4113            (!one->oid_valid ||
4114             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4115                struct stat st;
4116                if (lstat(name, &st) < 0) {
4117                        if (errno == ENOENT)
4118                                goto not_a_valid_file;
4119                        die_errno("stat(%s)", name);
4120                }
4121                if (S_ISLNK(st.st_mode)) {
4122                        struct strbuf sb = STRBUF_INIT;
4123                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4124                                die_errno("readlink(%s)", name);
4125                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4126                                       (one->oid_valid ?
4127                                        &one->oid : &null_oid),
4128                                       (one->oid_valid ?
4129                                        one->mode : S_IFLNK));
4130                        strbuf_release(&sb);
4131                }
4132                else {
4133                        /* we can borrow from the file in the work tree */
4134                        temp->name = name;
4135                        if (!one->oid_valid)
4136                                oid_to_hex_r(temp->hex, &null_oid);
4137                        else
4138                                oid_to_hex_r(temp->hex, &one->oid);
4139                        /* Even though we may sometimes borrow the
4140                         * contents from the work tree, we always want
4141                         * one->mode.  mode is trustworthy even when
4142                         * !(one->oid_valid), as long as
4143                         * DIFF_FILE_VALID(one).
4144                         */
4145                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4146                }
4147                return temp;
4148        }
4149        else {
4150                if (diff_populate_filespec(r, one, 0))
4151                        die("cannot read data blob for %s", one->path);
4152                prep_temp_blob(r->index, name, temp,
4153                               one->data, one->size,
4154                               &one->oid, one->mode);
4155        }
4156        return temp;
4157}
4158
4159static void add_external_diff_name(struct repository *r,
4160                                   struct argv_array *argv,
4161                                   const char *name,
4162                                   struct diff_filespec *df)
4163{
4164        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4165        argv_array_push(argv, temp->name);
4166        argv_array_push(argv, temp->hex);
4167        argv_array_push(argv, temp->mode);
4168}
4169
4170/* An external diff command takes:
4171 *
4172 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4173 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4174 *
4175 */
4176static void run_external_diff(const char *pgm,
4177                              const char *name,
4178                              const char *other,
4179                              struct diff_filespec *one,
4180                              struct diff_filespec *two,
4181                              const char *xfrm_msg,
4182                              struct diff_options *o)
4183{
4184        struct argv_array argv = ARGV_ARRAY_INIT;
4185        struct argv_array env = ARGV_ARRAY_INIT;
4186        struct diff_queue_struct *q = &diff_queued_diff;
4187
4188        argv_array_push(&argv, pgm);
4189        argv_array_push(&argv, name);
4190
4191        if (one && two) {
4192                add_external_diff_name(o->repo, &argv, name, one);
4193                if (!other)
4194                        add_external_diff_name(o->repo, &argv, name, two);
4195                else {
4196                        add_external_diff_name(o->repo, &argv, other, two);
4197                        argv_array_push(&argv, other);
4198                        argv_array_push(&argv, xfrm_msg);
4199                }
4200        }
4201
4202        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4203        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4204
4205        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4206                die(_("external diff died, stopping at %s"), name);
4207
4208        remove_tempfile();
4209        argv_array_clear(&argv);
4210        argv_array_clear(&env);
4211}
4212
4213static int similarity_index(struct diff_filepair *p)
4214{
4215        return p->score * 100 / MAX_SCORE;
4216}
4217
4218static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4219{
4220        if (startup_info->have_repository)
4221                return find_unique_abbrev(oid, abbrev);
4222        else {
4223                char *hex = oid_to_hex(oid);
4224                if (abbrev < 0)
4225                        abbrev = FALLBACK_DEFAULT_ABBREV;
4226                if (abbrev > the_hash_algo->hexsz)
4227                        BUG("oid abbreviation out of range: %d", abbrev);
4228                if (abbrev)
4229                        hex[abbrev] = '\0';
4230                return hex;
4231        }
4232}
4233
4234static void fill_metainfo(struct strbuf *msg,
4235                          const char *name,
4236                          const char *other,
4237                          struct diff_filespec *one,
4238                          struct diff_filespec *two,
4239                          struct diff_options *o,
4240                          struct diff_filepair *p,
4241                          int *must_show_header,
4242                          int use_color)
4243{
4244        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4245        const char *reset = diff_get_color(use_color, DIFF_RESET);
4246        const char *line_prefix = diff_line_prefix(o);
4247
4248        *must_show_header = 1;
4249        strbuf_init(msg, PATH_MAX * 2 + 300);
4250        switch (p->status) {
4251        case DIFF_STATUS_COPIED:
4252                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4253                            line_prefix, set, similarity_index(p));
4254                strbuf_addf(msg, "%s\n%s%scopy from ",
4255                            reset,  line_prefix, set);
4256                quote_c_style(name, msg, NULL, 0);
4257                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4258                quote_c_style(other, msg, NULL, 0);
4259                strbuf_addf(msg, "%s\n", reset);
4260                break;
4261        case DIFF_STATUS_RENAMED:
4262                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4263                            line_prefix, set, similarity_index(p));
4264                strbuf_addf(msg, "%s\n%s%srename from ",
4265                            reset, line_prefix, set);
4266                quote_c_style(name, msg, NULL, 0);
4267                strbuf_addf(msg, "%s\n%s%srename to ",
4268                            reset, line_prefix, set);
4269                quote_c_style(other, msg, NULL, 0);
4270                strbuf_addf(msg, "%s\n", reset);
4271                break;
4272        case DIFF_STATUS_MODIFIED:
4273                if (p->score) {
4274                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4275                                    line_prefix,
4276                                    set, similarity_index(p), reset);
4277                        break;
4278                }
4279                /* fallthru */
4280        default:
4281                *must_show_header = 0;
4282        }
4283        if (one && two && !oideq(&one->oid, &two->oid)) {
4284                const unsigned hexsz = the_hash_algo->hexsz;
4285                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4286
4287                if (o->flags.binary) {
4288                        mmfile_t mf;
4289                        if ((!fill_mmfile(o->repo, &mf, one) &&
4290                             diff_filespec_is_binary(o->repo, one)) ||
4291                            (!fill_mmfile(o->repo, &mf, two) &&
4292                             diff_filespec_is_binary(o->repo, two)))
4293                                abbrev = hexsz;
4294                }
4295                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4296                            diff_abbrev_oid(&one->oid, abbrev),
4297                            diff_abbrev_oid(&two->oid, abbrev));
4298                if (one->mode == two->mode)
4299                        strbuf_addf(msg, " %06o", one->mode);
4300                strbuf_addf(msg, "%s\n", reset);
4301        }
4302}
4303
4304static void run_diff_cmd(const char *pgm,
4305                         const char *name,
4306                         const char *other,
4307                         const char *attr_path,
4308                         struct diff_filespec *one,
4309                         struct diff_filespec *two,
4310                         struct strbuf *msg,
4311                         struct diff_options *o,
4312                         struct diff_filepair *p)
4313{
4314        const char *xfrm_msg = NULL;
4315        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4316        int must_show_header = 0;
4317
4318
4319        if (o->flags.allow_external) {
4320                struct userdiff_driver *drv;
4321
4322                drv = userdiff_find_by_path(o->repo->index, attr_path);
4323                if (drv && drv->external)
4324                        pgm = drv->external;
4325        }
4326
4327        if (msg) {
4328                /*
4329                 * don't use colors when the header is intended for an
4330                 * external diff driver
4331                 */
4332                fill_metainfo(msg, name, other, one, two, o, p,
4333                              &must_show_header,
4334                              want_color(o->use_color) && !pgm);
4335                xfrm_msg = msg->len ? msg->buf : NULL;
4336        }
4337
4338        if (pgm) {
4339                run_external_diff(pgm, name, other, one, two, xfrm_msg, o);
4340                return;
4341        }
4342        if (one && two)
4343                builtin_diff(name, other ? other : name,
4344                             one, two, xfrm_msg, must_show_header,
4345                             o, complete_rewrite);
4346        else
4347                fprintf(o->file, "* Unmerged path %s\n", name);
4348}
4349
4350static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4351{
4352        if (DIFF_FILE_VALID(one)) {
4353                if (!one->oid_valid) {
4354                        struct stat st;
4355                        if (one->is_stdin) {
4356                                oidclr(&one->oid);
4357                                return;
4358                        }
4359                        if (lstat(one->path, &st) < 0)
4360                                die_errno("stat '%s'", one->path);
4361                        if (index_path(istate, &one->oid, one->path, &st, 0))
4362                                die("cannot hash %s", one->path);
4363                }
4364        }
4365        else
4366                oidclr(&one->oid);
4367}
4368
4369static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4370{
4371        /* Strip the prefix but do not molest /dev/null and absolute paths */
4372        if (*namep && !is_absolute_path(*namep)) {
4373                *namep += prefix_length;
4374                if (**namep == '/')
4375                        ++*namep;
4376        }
4377        if (*otherp && !is_absolute_path(*otherp)) {
4378                *otherp += prefix_length;
4379                if (**otherp == '/')
4380                        ++*otherp;
4381        }
4382}
4383
4384static void run_diff(struct diff_filepair *p, struct diff_options *o)
4385{
4386        const char *pgm = external_diff();
4387        struct strbuf msg;
4388        struct diff_filespec *one = p->one;
4389        struct diff_filespec *two = p->two;
4390        const char *name;
4391        const char *other;
4392        const char *attr_path;
4393
4394        name  = one->path;
4395        other = (strcmp(name, two->path) ? two->path : NULL);
4396        attr_path = name;
4397        if (o->prefix_length)
4398                strip_prefix(o->prefix_length, &name, &other);
4399
4400        if (!o->flags.allow_external)
4401                pgm = NULL;
4402
4403        if (DIFF_PAIR_UNMERGED(p)) {
4404                run_diff_cmd(pgm, name, NULL, attr_path,
4405                             NULL, NULL, NULL, o, p);
4406                return;
4407        }
4408
4409        diff_fill_oid_info(one, o->repo->index);
4410        diff_fill_oid_info(two, o->repo->index);
4411
4412        if (!pgm &&
4413            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4414            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4415                /*
4416                 * a filepair that changes between file and symlink
4417                 * needs to be split into deletion and creation.
4418                 */
4419                struct diff_filespec *null = alloc_filespec(two->path);
4420                run_diff_cmd(NULL, name, other, attr_path,
4421                             one, null, &msg,
4422                             o, p);
4423                free(null);
4424                strbuf_release(&msg);
4425
4426                null = alloc_filespec(one->path);
4427                run_diff_cmd(NULL, name, other, attr_path,
4428                             null, two, &msg, o, p);
4429                free(null);
4430        }
4431        else
4432                run_diff_cmd(pgm, name, other, attr_path,
4433                             one, two, &msg, o, p);
4434
4435        strbuf_release(&msg);
4436}
4437
4438static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4439                         struct diffstat_t *diffstat)
4440{
4441        const char *name;
4442        const char *other;
4443
4444        if (DIFF_PAIR_UNMERGED(p)) {
4445                /* unmerged */
4446                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4447                                 diffstat, o, p);
4448                return;
4449        }
4450
4451        name = p->one->path;
4452        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4453
4454        if (o->prefix_length)
4455                strip_prefix(o->prefix_length, &name, &other);
4456
4457        diff_fill_oid_info(p->one, o->repo->index);
4458        diff_fill_oid_info(p->two, o->repo->index);
4459
4460        builtin_diffstat(name, other, p->one, p->two,
4461                         diffstat, o, p);
4462}
4463
4464static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4465{
4466        const char *name;
4467        const char *other;
4468        const char *attr_path;
4469
4470        if (DIFF_PAIR_UNMERGED(p)) {
4471                /* unmerged */
4472                return;
4473        }
4474
4475        name = p->one->path;
4476        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4477        attr_path = other ? other : name;
4478
4479        if (o->prefix_length)
4480                strip_prefix(o->prefix_length, &name, &other);
4481
4482        diff_fill_oid_info(p->one, o->repo->index);
4483        diff_fill_oid_info(p->two, o->repo->index);
4484
4485        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4486}
4487
4488static void prep_parse_options(struct diff_options *options);
4489
4490void repo_diff_setup(struct repository *r, struct diff_options *options)
4491{
4492        memcpy(options, &default_diff_options, sizeof(*options));
4493
4494        options->file = stdout;
4495        options->repo = r;
4496
4497        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4498        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4499        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4500        options->abbrev = DEFAULT_ABBREV;
4501        options->line_termination = '\n';
4502        options->break_opt = -1;
4503        options->rename_limit = -1;
4504        options->dirstat_permille = diff_dirstat_permille_default;
4505        options->context = diff_context_default;
4506        options->interhunkcontext = diff_interhunk_context_default;
4507        options->ws_error_highlight = ws_error_highlight_default;
4508        options->flags.rename_empty = 1;
4509        options->objfind = NULL;
4510
4511        /* pathchange left =NULL by default */
4512        options->change = diff_change;
4513        options->add_remove = diff_addremove;
4514        options->use_color = diff_use_color_default;
4515        options->detect_rename = diff_detect_rename_default;
4516        options->xdl_opts |= diff_algorithm;
4517        if (diff_indent_heuristic)
4518                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4519
4520        options->orderfile = diff_order_file_cfg;
4521
4522        if (diff_no_prefix) {
4523                options->a_prefix = options->b_prefix = "";
4524        } else if (!diff_mnemonic_prefix) {
4525                options->a_prefix = "a/";
4526                options->b_prefix = "b/";
4527        }
4528
4529        options->color_moved = diff_color_moved_default;
4530        options->color_moved_ws_handling = diff_color_moved_ws_default;
4531
4532        prep_parse_options(options);
4533}
4534
4535void diff_setup_done(struct diff_options *options)
4536{
4537        unsigned check_mask = DIFF_FORMAT_NAME |
4538                              DIFF_FORMAT_NAME_STATUS |
4539                              DIFF_FORMAT_CHECKDIFF |
4540                              DIFF_FORMAT_NO_OUTPUT;
4541        /*
4542         * This must be signed because we're comparing against a potentially
4543         * negative value.
4544         */
4545        const int hexsz = the_hash_algo->hexsz;
4546
4547        if (options->set_default)
4548                options->set_default(options);
4549
4550        if (HAS_MULTI_BITS(options->output_format & check_mask))
4551                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4552
4553        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4554                die(_("-G, -S and --find-object are mutually exclusive"));
4555
4556        /*
4557         * Most of the time we can say "there are changes"
4558         * only by checking if there are changed paths, but
4559         * --ignore-whitespace* options force us to look
4560         * inside contents.
4561         */
4562
4563        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4564                options->flags.diff_from_contents = 1;
4565        else
4566                options->flags.diff_from_contents = 0;
4567
4568        if (options->flags.find_copies_harder)
4569                options->detect_rename = DIFF_DETECT_COPY;
4570
4571        if (!options->flags.relative_name)
4572                options->prefix = NULL;
4573        if (options->prefix)
4574                options->prefix_length = strlen(options->prefix);
4575        else
4576                options->prefix_length = 0;
4577
4578        if (options->output_format & (DIFF_FORMAT_NAME |
4579                                      DIFF_FORMAT_NAME_STATUS |
4580                                      DIFF_FORMAT_CHECKDIFF |
4581                                      DIFF_FORMAT_NO_OUTPUT))
4582                options->output_format &= ~(DIFF_FORMAT_RAW |
4583                                            DIFF_FORMAT_NUMSTAT |
4584                                            DIFF_FORMAT_DIFFSTAT |
4585                                            DIFF_FORMAT_SHORTSTAT |
4586                                            DIFF_FORMAT_DIRSTAT |
4587                                            DIFF_FORMAT_SUMMARY |
4588                                            DIFF_FORMAT_PATCH);
4589
4590        /*
4591         * These cases always need recursive; we do not drop caller-supplied
4592         * recursive bits for other formats here.
4593         */
4594        if (options->output_format & (DIFF_FORMAT_PATCH |
4595                                      DIFF_FORMAT_NUMSTAT |
4596                                      DIFF_FORMAT_DIFFSTAT |
4597                                      DIFF_FORMAT_SHORTSTAT |
4598                                      DIFF_FORMAT_DIRSTAT |
4599                                      DIFF_FORMAT_SUMMARY |
4600                                      DIFF_FORMAT_CHECKDIFF))
4601                options->flags.recursive = 1;
4602        /*
4603         * Also pickaxe would not work very well if you do not say recursive
4604         */
4605        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4606                options->flags.recursive = 1;
4607        /*
4608         * When patches are generated, submodules diffed against the work tree
4609         * must be checked for dirtiness too so it can be shown in the output
4610         */
4611        if (options->output_format & DIFF_FORMAT_PATCH)
4612                options->flags.dirty_submodules = 1;
4613
4614        if (options->detect_rename && options->rename_limit < 0)
4615                options->rename_limit = diff_rename_limit_default;
4616        if (hexsz < options->abbrev)
4617                options->abbrev = hexsz; /* full */
4618
4619        /*
4620         * It does not make sense to show the first hit we happened
4621         * to have found.  It does not make sense not to return with
4622         * exit code in such a case either.
4623         */
4624        if (options->flags.quick) {
4625                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4626                options->flags.exit_with_status = 1;
4627        }
4628
4629        options->diff_path_counter = 0;
4630
4631        if (options->flags.follow_renames && options->pathspec.nr != 1)
4632                die(_("--follow requires exactly one pathspec"));
4633
4634        if (!options->use_color || external_diff())
4635                options->color_moved = 0;
4636
4637        FREE_AND_NULL(options->parseopts);
4638}
4639
4640static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4641{
4642        char c, *eq;
4643        int len;
4644
4645        if (*arg != '-')
4646                return 0;
4647        c = *++arg;
4648        if (!c)
4649                return 0;
4650        if (c == arg_short) {
4651                c = *++arg;
4652                if (!c)
4653                        return 1;
4654                if (val && isdigit(c)) {
4655                        char *end;
4656                        int n = strtoul(arg, &end, 10);
4657                        if (*end)
4658                                return 0;
4659                        *val = n;
4660                        return 1;
4661                }
4662                return 0;
4663        }
4664        if (c != '-')
4665                return 0;
4666        arg++;
4667        eq = strchrnul(arg, '=');
4668        len = eq - arg;
4669        if (!len || strncmp(arg, arg_long, len))
4670                return 0;
4671        if (*eq) {
4672                int n;
4673                char *end;
4674                if (!isdigit(*++eq))
4675                        return 0;
4676                n = strtoul(eq, &end, 10);
4677                if (*end)
4678                        return 0;
4679                *val = n;
4680        }
4681        return 1;
4682}
4683
4684static int diff_scoreopt_parse(const char *opt);
4685
4686static inline int short_opt(char opt, const char **argv,
4687                            const char **optarg)
4688{
4689        const char *arg = argv[0];
4690        if (arg[0] != '-' || arg[1] != opt)
4691                return 0;
4692        if (arg[2] != '\0') {
4693                *optarg = arg + 2;
4694                return 1;
4695        }
4696        if (!argv[1])
4697                die("Option '%c' requires a value", opt);
4698        *optarg = argv[1];
4699        return 2;
4700}
4701
4702int parse_long_opt(const char *opt, const char **argv,
4703                   const char **optarg)
4704{
4705        const char *arg = argv[0];
4706        if (!skip_prefix(arg, "--", &arg))
4707                return 0;
4708        if (!skip_prefix(arg, opt, &arg))
4709                return 0;
4710        if (*arg == '=') { /* stuck form: --option=value */
4711                *optarg = arg + 1;
4712                return 1;
4713        }
4714        if (*arg != '\0')
4715                return 0;
4716        /* separate form: --option value */
4717        if (!argv[1])
4718                die("Option '--%s' requires a value", opt);
4719        *optarg = argv[1];
4720        return 2;
4721}
4722
4723static int stat_opt(struct diff_options *options, const char **av)
4724{
4725        const char *arg = av[0];
4726        char *end;
4727        int width = options->stat_width;
4728        int name_width = options->stat_name_width;
4729        int graph_width = options->stat_graph_width;
4730        int count = options->stat_count;
4731        int argcount = 1;
4732
4733        if (!skip_prefix(arg, "--stat", &arg))
4734                BUG("stat option does not begin with --stat: %s", arg);
4735        end = (char *)arg;
4736
4737        switch (*arg) {
4738        case '-':
4739                if (skip_prefix(arg, "-width", &arg)) {
4740                        if (*arg == '=')
4741                                width = strtoul(arg + 1, &end, 10);
4742                        else if (!*arg && !av[1])
4743                                die_want_option("--stat-width");
4744                        else if (!*arg) {
4745                                width = strtoul(av[1], &end, 10);
4746                                argcount = 2;
4747                        }
4748                } else if (skip_prefix(arg, "-name-width", &arg)) {
4749                        if (*arg == '=')
4750                                name_width = strtoul(arg + 1, &end, 10);
4751                        else if (!*arg && !av[1])
4752                                die_want_option("--stat-name-width");
4753                        else if (!*arg) {
4754                                name_width = strtoul(av[1], &end, 10);
4755                                argcount = 2;
4756                        }
4757                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4758                        if (*arg == '=')
4759                                graph_width = strtoul(arg + 1, &end, 10);
4760                        else if (!*arg && !av[1])
4761                                die_want_option("--stat-graph-width");
4762                        else if (!*arg) {
4763                                graph_width = strtoul(av[1], &end, 10);
4764                                argcount = 2;
4765                        }
4766                } else if (skip_prefix(arg, "-count", &arg)) {
4767                        if (*arg == '=')
4768                                count = strtoul(arg + 1, &end, 10);
4769                        else if (!*arg && !av[1])
4770                                die_want_option("--stat-count");
4771                        else if (!*arg) {
4772                                count = strtoul(av[1], &end, 10);
4773                                argcount = 2;
4774                        }
4775                }
4776                break;
4777        case '=':
4778                width = strtoul(arg+1, &end, 10);
4779                if (*end == ',')
4780                        name_width = strtoul(end+1, &end, 10);
4781                if (*end == ',')
4782                        count = strtoul(end+1, &end, 10);
4783        }
4784
4785        /* Important! This checks all the error cases! */
4786        if (*end)
4787                return 0;
4788        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4789        options->stat_name_width = name_width;
4790        options->stat_graph_width = graph_width;
4791        options->stat_width = width;
4792        options->stat_count = count;
4793        return argcount;
4794}
4795
4796static int parse_dirstat_opt(struct diff_options *options, const char *params)
4797{
4798        struct strbuf errmsg = STRBUF_INIT;
4799        if (parse_dirstat_params(options, params, &errmsg))
4800                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4801                    errmsg.buf);
4802        strbuf_release(&errmsg);
4803        /*
4804         * The caller knows a dirstat-related option is given from the command
4805         * line; allow it to say "return this_function();"
4806         */
4807        options->output_format |= DIFF_FORMAT_DIRSTAT;
4808        return 1;
4809}
4810
4811static int parse_submodule_opt(struct diff_options *options, const char *value)
4812{
4813        if (parse_submodule_params(options, value))
4814                die(_("Failed to parse --submodule option parameter: '%s'"),
4815                        value);
4816        return 1;
4817}
4818
4819static const char diff_status_letters[] = {
4820        DIFF_STATUS_ADDED,
4821        DIFF_STATUS_COPIED,
4822        DIFF_STATUS_DELETED,
4823        DIFF_STATUS_MODIFIED,
4824        DIFF_STATUS_RENAMED,
4825        DIFF_STATUS_TYPE_CHANGED,
4826        DIFF_STATUS_UNKNOWN,
4827        DIFF_STATUS_UNMERGED,
4828        DIFF_STATUS_FILTER_AON,
4829        DIFF_STATUS_FILTER_BROKEN,
4830        '\0',
4831};
4832
4833static unsigned int filter_bit['Z' + 1];
4834
4835static void prepare_filter_bits(void)
4836{
4837        int i;
4838
4839        if (!filter_bit[DIFF_STATUS_ADDED]) {
4840                for (i = 0; diff_status_letters[i]; i++)
4841                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4842        }
4843}
4844
4845static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4846{
4847        return opt->filter & filter_bit[(int) status];
4848}
4849
4850static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4851{
4852        int i, optch;
4853
4854        prepare_filter_bits();
4855
4856        /*
4857         * If there is a negation e.g. 'd' in the input, and we haven't
4858         * initialized the filter field with another --diff-filter, start
4859         * from full set of bits, except for AON.
4860         */
4861        if (!opt->filter) {
4862                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4863                        if (optch < 'a' || 'z' < optch)
4864                                continue;
4865                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4866                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4867                        break;
4868                }
4869        }
4870
4871        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4872                unsigned int bit;
4873                int negate;
4874
4875                if ('a' <= optch && optch <= 'z') {
4876                        negate = 1;
4877                        optch = toupper(optch);
4878                } else {
4879                        negate = 0;
4880                }
4881
4882                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4883                if (!bit)
4884                        return optarg[i];
4885                if (negate)
4886                        opt->filter &= ~bit;
4887                else
4888                        opt->filter |= bit;
4889        }
4890        return 0;
4891}
4892
4893static void enable_patch_output(int *fmt)
4894{
4895        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4896        *fmt |= DIFF_FORMAT_PATCH;
4897}
4898
4899static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4900{
4901        int val = parse_ws_error_highlight(arg);
4902
4903        if (val < 0) {
4904                error("unknown value after ws-error-highlight=%.*s",
4905                      -1 - val, arg);
4906                return 0;
4907        }
4908        opt->ws_error_highlight = val;
4909        return 1;
4910}
4911
4912static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4913{
4914        struct object_id oid;
4915
4916        if (get_oid(arg, &oid))
4917                return error("unable to resolve '%s'", arg);
4918
4919        if (!opt->objfind)
4920                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4921
4922        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4923        opt->flags.recursive = 1;
4924        opt->flags.tree_in_recursive = 1;
4925        oidset_insert(opt->objfind, &oid);
4926        return 1;
4927}
4928
4929static int diff_opt_unified(const struct option *opt,
4930                            const char *arg, int unset)
4931{
4932        struct diff_options *options = opt->value;
4933        char *s;
4934
4935        BUG_ON_OPT_NEG(unset);
4936
4937        options->context = strtol(arg, &s, 10);
4938        if (*s)
4939                return error(_("%s expects a numerical value"), "--unified");
4940        enable_patch_output(&options->output_format);
4941
4942        return 0;
4943}
4944
4945static void prep_parse_options(struct diff_options *options)
4946{
4947        struct option parseopts[] = {
4948                OPT_GROUP(N_("Diff output format options")),
4949                OPT_BITOP('p', "patch", &options->output_format,
4950                          N_("generate patch"),
4951                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
4952                OPT_BITOP('u', NULL, &options->output_format,
4953                          N_("generate patch"),
4954                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
4955                OPT_CALLBACK_F('U', "unified", options, N_("<n>"),
4956                               N_("generate diffs with <n> lines context"),
4957                               PARSE_OPT_NONEG, diff_opt_unified),
4958                OPT_BOOL('W', "function-context", &options->flags.funccontext,
4959                         N_("generate diffs with <n> lines context")),
4960                OPT_BIT_F(0, "raw", &options->output_format,
4961                          N_("generate the diff in raw format"),
4962                          DIFF_FORMAT_RAW, PARSE_OPT_NONEG),
4963                OPT_END()
4964        };
4965
4966        ALLOC_ARRAY(options->parseopts, ARRAY_SIZE(parseopts));
4967        memcpy(options->parseopts, parseopts, sizeof(parseopts));
4968}
4969
4970int diff_opt_parse(struct diff_options *options,
4971                   const char **av, int ac, const char *prefix)
4972{
4973        const char *arg = av[0];
4974        const char *optarg;
4975        int argcount;
4976
4977        if (!prefix)
4978                prefix = "";
4979
4980        ac = parse_options(ac, av, prefix, options->parseopts, NULL,
4981                           PARSE_OPT_KEEP_DASHDASH |
4982                           PARSE_OPT_KEEP_UNKNOWN |
4983                           PARSE_OPT_NO_INTERNAL_HELP |
4984                           PARSE_OPT_ONE_SHOT |
4985                           PARSE_OPT_STOP_AT_NON_OPTION);
4986
4987        if (ac)
4988                return ac;
4989
4990        /* Output format options */
4991        if (!strcmp(arg, "--patch-with-raw")) {
4992                enable_patch_output(&options->output_format);
4993                options->output_format |= DIFF_FORMAT_RAW;
4994        } else if (!strcmp(arg, "--numstat"))
4995                options->output_format |= DIFF_FORMAT_NUMSTAT;
4996        else if (!strcmp(arg, "--shortstat"))
4997                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4998        else if (skip_prefix(arg, "-X", &arg) ||
4999                 skip_to_optional_arg(arg, "--dirstat", &arg))
5000                return parse_dirstat_opt(options, arg);
5001        else if (!strcmp(arg, "--cumulative"))
5002                return parse_dirstat_opt(options, "cumulative");
5003        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
5004                parse_dirstat_opt(options, "files");
5005                return parse_dirstat_opt(options, arg);
5006        }
5007        else if (!strcmp(arg, "--check"))
5008                options->output_format |= DIFF_FORMAT_CHECKDIFF;
5009        else if (!strcmp(arg, "--summary"))
5010                options->output_format |= DIFF_FORMAT_SUMMARY;
5011        else if (!strcmp(arg, "--patch-with-stat")) {
5012                enable_patch_output(&options->output_format);
5013                options->output_format |= DIFF_FORMAT_DIFFSTAT;
5014        } else if (!strcmp(arg, "--name-only"))
5015                options->output_format |= DIFF_FORMAT_NAME;
5016        else if (!strcmp(arg, "--name-status"))
5017                options->output_format |= DIFF_FORMAT_NAME_STATUS;
5018        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
5019                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
5020        else if (starts_with(arg, "--stat"))
5021                /* --stat, --stat-width, --stat-name-width, or --stat-count */
5022                return stat_opt(options, av);
5023        else if (!strcmp(arg, "--compact-summary")) {
5024                 options->flags.stat_with_summary = 1;
5025                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
5026        } else if (!strcmp(arg, "--no-compact-summary"))
5027                 options->flags.stat_with_summary = 0;
5028        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
5029                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
5030        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
5031                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
5032        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
5033                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
5034
5035        /* renames options */
5036        else if (starts_with(arg, "-B") ||
5037                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
5038                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
5039                        return error("invalid argument to -B: %s", arg+2);
5040        }
5041        else if (starts_with(arg, "-M") ||
5042                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
5043                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
5044                        return error("invalid argument to -M: %s", arg+2);
5045                options->detect_rename = DIFF_DETECT_RENAME;
5046        }
5047        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
5048                options->irreversible_delete = 1;
5049        }
5050        else if (starts_with(arg, "-C") ||
5051                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
5052                if (options->detect_rename == DIFF_DETECT_COPY)
5053                        options->flags.find_copies_harder = 1;
5054                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
5055                        return error("invalid argument to -C: %s", arg+2);
5056                options->detect_rename = DIFF_DETECT_COPY;
5057        }
5058        else if (!strcmp(arg, "--no-renames"))
5059                options->detect_rename = 0;
5060        else if (!strcmp(arg, "--rename-empty"))
5061                options->flags.rename_empty = 1;
5062        else if (!strcmp(arg, "--no-rename-empty"))
5063                options->flags.rename_empty = 0;
5064        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
5065                options->flags.relative_name = 1;
5066                if (arg)
5067                        options->prefix = arg;
5068        }
5069
5070        /* xdiff options */
5071        else if (!strcmp(arg, "--minimal"))
5072                DIFF_XDL_SET(options, NEED_MINIMAL);
5073        else if (!strcmp(arg, "--no-minimal"))
5074                DIFF_XDL_CLR(options, NEED_MINIMAL);
5075        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
5076                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
5077        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
5078                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
5079        else if (!strcmp(arg, "--ignore-space-at-eol"))
5080                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
5081        else if (!strcmp(arg, "--ignore-cr-at-eol"))
5082                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
5083        else if (!strcmp(arg, "--ignore-blank-lines"))
5084                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
5085        else if (!strcmp(arg, "--indent-heuristic"))
5086                DIFF_XDL_SET(options, INDENT_HEURISTIC);
5087        else if (!strcmp(arg, "--no-indent-heuristic"))
5088                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
5089        else if (!strcmp(arg, "--patience")) {
5090                int i;
5091                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5092                /*
5093                 * Both --patience and --anchored use PATIENCE_DIFF
5094                 * internally, so remove any anchors previously
5095                 * specified.
5096                 */
5097                for (i = 0; i < options->anchors_nr; i++)
5098                        free(options->anchors[i]);
5099                options->anchors_nr = 0;
5100        } else if (!strcmp(arg, "--histogram"))
5101                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
5102        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
5103                long value = parse_algorithm_value(optarg);
5104                if (value < 0)
5105                        return error("option diff-algorithm accepts \"myers\", "
5106                                     "\"minimal\", \"patience\" and \"histogram\"");
5107                /* clear out previous settings */
5108                DIFF_XDL_CLR(options, NEED_MINIMAL);
5109                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
5110                options->xdl_opts |= value;
5111                return argcount;
5112        } else if (skip_prefix(arg, "--anchored=", &arg)) {
5113                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5114                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
5115                           options->anchors_alloc);
5116                options->anchors[options->anchors_nr++] = xstrdup(arg);
5117        }
5118
5119        /* flags options */
5120        else if (!strcmp(arg, "--binary")) {
5121                enable_patch_output(&options->output_format);
5122                options->flags.binary = 1;
5123        }
5124        else if (!strcmp(arg, "--full-index"))
5125                options->flags.full_index = 1;
5126        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
5127                options->flags.text = 1;
5128        else if (!strcmp(arg, "-R"))
5129                options->flags.reverse_diff = 1;
5130        else if (!strcmp(arg, "--find-copies-harder"))
5131                options->flags.find_copies_harder = 1;
5132        else if (!strcmp(arg, "--follow"))
5133                options->flags.follow_renames = 1;
5134        else if (!strcmp(arg, "--no-follow")) {
5135                options->flags.follow_renames = 0;
5136                options->flags.default_follow_renames = 0;
5137        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5138                int value = git_config_colorbool(NULL, arg);
5139                if (value < 0)
5140                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5141                options->use_color = value;
5142        }
5143        else if (!strcmp(arg, "--no-color"))
5144                options->use_color = 0;
5145        else if (!strcmp(arg, "--color-moved")) {
5146                if (diff_color_moved_default)
5147                        options->color_moved = diff_color_moved_default;
5148                if (options->color_moved == COLOR_MOVED_NO)
5149                        options->color_moved = COLOR_MOVED_DEFAULT;
5150        } else if (!strcmp(arg, "--no-color-moved"))
5151                options->color_moved = COLOR_MOVED_NO;
5152        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5153                int cm = parse_color_moved(arg);
5154                if (cm < 0)
5155                        return error("bad --color-moved argument: %s", arg);
5156                options->color_moved = cm;
5157        } else if (!strcmp(arg, "--no-color-moved-ws")) {
5158                options->color_moved_ws_handling = 0;
5159        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5160                unsigned cm = parse_color_moved_ws(arg);
5161                if (cm & COLOR_MOVED_WS_ERROR)
5162                        return -1;
5163                options->color_moved_ws_handling = cm;
5164        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5165                options->use_color = 1;
5166                options->word_diff = DIFF_WORDS_COLOR;
5167        }
5168        else if (!strcmp(arg, "--word-diff")) {
5169                if (options->word_diff == DIFF_WORDS_NONE)
5170                        options->word_diff = DIFF_WORDS_PLAIN;
5171        }
5172        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5173                if (!strcmp(arg, "plain"))
5174                        options->word_diff = DIFF_WORDS_PLAIN;
5175                else if (!strcmp(arg, "color")) {
5176                        options->use_color = 1;
5177                        options->word_diff = DIFF_WORDS_COLOR;
5178                }
5179                else if (!strcmp(arg, "porcelain"))
5180                        options->word_diff = DIFF_WORDS_PORCELAIN;
5181                else if (!strcmp(arg, "none"))
5182                        options->word_diff = DIFF_WORDS_NONE;
5183                else
5184                        die("bad --word-diff argument: %s", arg);
5185        }
5186        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5187                if (options->word_diff == DIFF_WORDS_NONE)
5188                        options->word_diff = DIFF_WORDS_PLAIN;
5189                options->word_regex = optarg;
5190                return argcount;
5191        }
5192        else if (!strcmp(arg, "--exit-code"))
5193                options->flags.exit_with_status = 1;
5194        else if (!strcmp(arg, "--quiet"))
5195                options->flags.quick = 1;
5196        else if (!strcmp(arg, "--ext-diff"))
5197                options->flags.allow_external = 1;
5198        else if (!strcmp(arg, "--no-ext-diff"))
5199                options->flags.allow_external = 0;
5200        else if (!strcmp(arg, "--textconv")) {
5201                options->flags.allow_textconv = 1;
5202                options->flags.textconv_set_via_cmdline = 1;
5203        } else if (!strcmp(arg, "--no-textconv"))
5204                options->flags.allow_textconv = 0;
5205        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5206                options->flags.override_submodule_config = 1;
5207                handle_ignore_submodules_arg(options, arg);
5208        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5209                return parse_submodule_opt(options, arg);
5210        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5211                return parse_ws_error_highlight_opt(options, arg);
5212        else if (!strcmp(arg, "--ita-invisible-in-index"))
5213                options->ita_invisible_in_index = 1;
5214        else if (!strcmp(arg, "--ita-visible-in-index"))
5215                options->ita_invisible_in_index = 0;
5216
5217        /* misc options */
5218        else if (!strcmp(arg, "-z"))
5219                options->line_termination = 0;
5220        else if ((argcount = short_opt('l', av, &optarg))) {
5221                options->rename_limit = strtoul(optarg, NULL, 10);
5222                return argcount;
5223        }
5224        else if ((argcount = short_opt('S', av, &optarg))) {
5225                options->pickaxe = optarg;
5226                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5227                return argcount;
5228        } else if ((argcount = short_opt('G', av, &optarg))) {
5229                options->pickaxe = optarg;
5230                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5231                return argcount;
5232        }
5233        else if (!strcmp(arg, "--pickaxe-all"))
5234                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5235        else if (!strcmp(arg, "--pickaxe-regex"))
5236                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5237        else if ((argcount = short_opt('O', av, &optarg))) {
5238                options->orderfile = prefix_filename(prefix, optarg);
5239                return argcount;
5240        } else if (skip_prefix(arg, "--find-object=", &arg))
5241                return parse_objfind_opt(options, arg);
5242        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5243                int offending = parse_diff_filter_opt(optarg, options);
5244                if (offending)
5245                        die("unknown change class '%c' in --diff-filter=%s",
5246                            offending, optarg);
5247                return argcount;
5248        }
5249        else if (!strcmp(arg, "--no-abbrev"))
5250                options->abbrev = 0;
5251        else if (!strcmp(arg, "--abbrev"))
5252                options->abbrev = DEFAULT_ABBREV;
5253        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5254                options->abbrev = strtoul(arg, NULL, 10);
5255                if (options->abbrev < MINIMUM_ABBREV)
5256                        options->abbrev = MINIMUM_ABBREV;
5257                else if (the_hash_algo->hexsz < options->abbrev)
5258                        options->abbrev = the_hash_algo->hexsz;
5259        }
5260        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5261                options->a_prefix = optarg;
5262                return argcount;
5263        }
5264        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5265                options->line_prefix = optarg;
5266                options->line_prefix_length = strlen(options->line_prefix);
5267                graph_setup_line_prefix(options);
5268                return argcount;
5269        }
5270        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5271                options->b_prefix = optarg;
5272                return argcount;
5273        }
5274        else if (!strcmp(arg, "--no-prefix"))
5275                options->a_prefix = options->b_prefix = "";
5276        else if (opt_arg(arg, '\0', "inter-hunk-context",
5277                         &options->interhunkcontext))
5278                ;
5279        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5280                char *path = prefix_filename(prefix, optarg);
5281                options->file = xfopen(path, "w");
5282                options->close_file = 1;
5283                if (options->use_color != GIT_COLOR_ALWAYS)
5284                        options->use_color = GIT_COLOR_NEVER;
5285                free(path);
5286                return argcount;
5287        } else
5288                return 0;
5289        return 1;
5290}
5291
5292int parse_rename_score(const char **cp_p)
5293{
5294        unsigned long num, scale;
5295        int ch, dot;
5296        const char *cp = *cp_p;
5297
5298        num = 0;
5299        scale = 1;
5300        dot = 0;
5301        for (;;) {
5302                ch = *cp;
5303                if ( !dot && ch == '.' ) {
5304                        scale = 1;
5305                        dot = 1;
5306                } else if ( ch == '%' ) {
5307                        scale = dot ? scale*100 : 100;
5308                        cp++;   /* % is always at the end */
5309                        break;
5310                } else if ( ch >= '0' && ch <= '9' ) {
5311                        if ( scale < 100000 ) {
5312                                scale *= 10;
5313                                num = (num*10) + (ch-'0');
5314                        }
5315                } else {
5316                        break;
5317                }
5318                cp++;
5319        }
5320        *cp_p = cp;
5321
5322        /* user says num divided by scale and we say internally that
5323         * is MAX_SCORE * num / scale.
5324         */
5325        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5326}
5327
5328static int diff_scoreopt_parse(const char *opt)
5329{
5330        int opt1, opt2, cmd;
5331
5332        if (*opt++ != '-')
5333                return -1;
5334        cmd = *opt++;
5335        if (cmd == '-') {
5336                /* convert the long-form arguments into short-form versions */
5337                if (skip_prefix(opt, "break-rewrites", &opt)) {
5338                        if (*opt == 0 || *opt++ == '=')
5339                                cmd = 'B';
5340                } else if (skip_prefix(opt, "find-copies", &opt)) {
5341                        if (*opt == 0 || *opt++ == '=')
5342                                cmd = 'C';
5343                } else if (skip_prefix(opt, "find-renames", &opt)) {
5344                        if (*opt == 0 || *opt++ == '=')
5345                                cmd = 'M';
5346                }
5347        }
5348        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5349                return -1; /* that is not a -M, -C, or -B option */
5350
5351        opt1 = parse_rename_score(&opt);
5352        if (cmd != 'B')
5353                opt2 = 0;
5354        else {
5355                if (*opt == 0)
5356                        opt2 = 0;
5357                else if (*opt != '/')
5358                        return -1; /* we expect -B80/99 or -B80 */
5359                else {
5360                        opt++;
5361                        opt2 = parse_rename_score(&opt);
5362                }
5363        }
5364        if (*opt != 0)
5365                return -1;
5366        return opt1 | (opt2 << 16);
5367}
5368
5369struct diff_queue_struct diff_queued_diff;
5370
5371void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5372{
5373        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5374        queue->queue[queue->nr++] = dp;
5375}
5376
5377struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5378                                 struct diff_filespec *one,
5379                                 struct diff_filespec *two)
5380{
5381        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5382        dp->one = one;
5383        dp->two = two;
5384        if (queue)
5385                diff_q(queue, dp);
5386        return dp;
5387}
5388
5389void diff_free_filepair(struct diff_filepair *p)
5390{
5391        free_filespec(p->one);
5392        free_filespec(p->two);
5393        free(p);
5394}
5395
5396const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5397{
5398        int abblen;
5399        const char *abbrev;
5400
5401        /* Do we want all 40 hex characters? */
5402        if (len == the_hash_algo->hexsz)
5403                return oid_to_hex(oid);
5404
5405        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5406        abbrev = diff_abbrev_oid(oid, len);
5407
5408        if (!print_sha1_ellipsis())
5409                return abbrev;
5410
5411        abblen = strlen(abbrev);
5412
5413        /*
5414         * In well-behaved cases, where the abbreviated result is the
5415         * same as the requested length, append three dots after the
5416         * abbreviation (hence the whole logic is limited to the case
5417         * where abblen < 37); when the actual abbreviated result is a
5418         * bit longer than the requested length, we reduce the number
5419         * of dots so that they match the well-behaved ones.  However,
5420         * if the actual abbreviation is longer than the requested
5421         * length by more than three, we give up on aligning, and add
5422         * three dots anyway, to indicate that the output is not the
5423         * full object name.  Yes, this may be suboptimal, but this
5424         * appears only in "diff --raw --abbrev" output and it is not
5425         * worth the effort to change it now.  Note that this would
5426         * likely to work fine when the automatic sizing of default
5427         * abbreviation length is used--we would be fed -1 in "len" in
5428         * that case, and will end up always appending three-dots, but
5429         * the automatic sizing is supposed to give abblen that ensures
5430         * uniqueness across all objects (statistically speaking).
5431         */
5432        if (abblen < the_hash_algo->hexsz - 3) {
5433                static char hex[GIT_MAX_HEXSZ + 1];
5434                if (len < abblen && abblen <= len + 2)
5435                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5436                else
5437                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5438                return hex;
5439        }
5440
5441        return oid_to_hex(oid);
5442}
5443
5444static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5445{
5446        int line_termination = opt->line_termination;
5447        int inter_name_termination = line_termination ? '\t' : '\0';
5448
5449        fprintf(opt->file, "%s", diff_line_prefix(opt));
5450        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5451                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5452                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5453                fprintf(opt->file, "%s ",
5454                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5455        }
5456        if (p->score) {
5457                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5458                        inter_name_termination);
5459        } else {
5460                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5461        }
5462
5463        if (p->status == DIFF_STATUS_COPIED ||
5464            p->status == DIFF_STATUS_RENAMED) {
5465                const char *name_a, *name_b;
5466                name_a = p->one->path;
5467                name_b = p->two->path;
5468                strip_prefix(opt->prefix_length, &name_a, &name_b);
5469                write_name_quoted(name_a, opt->file, inter_name_termination);
5470                write_name_quoted(name_b, opt->file, line_termination);
5471        } else {
5472                const char *name_a, *name_b;
5473                name_a = p->one->mode ? p->one->path : p->two->path;
5474                name_b = NULL;
5475                strip_prefix(opt->prefix_length, &name_a, &name_b);
5476                write_name_quoted(name_a, opt->file, line_termination);
5477        }
5478}
5479
5480int diff_unmodified_pair(struct diff_filepair *p)
5481{
5482        /* This function is written stricter than necessary to support
5483         * the currently implemented transformers, but the idea is to
5484         * let transformers to produce diff_filepairs any way they want,
5485         * and filter and clean them up here before producing the output.
5486         */
5487        struct diff_filespec *one = p->one, *two = p->two;
5488
5489        if (DIFF_PAIR_UNMERGED(p))
5490                return 0; /* unmerged is interesting */
5491
5492        /* deletion, addition, mode or type change
5493         * and rename are all interesting.
5494         */
5495        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5496            DIFF_PAIR_MODE_CHANGED(p) ||
5497            strcmp(one->path, two->path))
5498                return 0;
5499
5500        /* both are valid and point at the same path.  that is, we are
5501         * dealing with a change.
5502         */
5503        if (one->oid_valid && two->oid_valid &&
5504            oideq(&one->oid, &two->oid) &&
5505            !one->dirty_submodule && !two->dirty_submodule)
5506                return 1; /* no change */
5507        if (!one->oid_valid && !two->oid_valid)
5508                return 1; /* both look at the same file on the filesystem. */
5509        return 0;
5510}
5511
5512static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5513{
5514        if (diff_unmodified_pair(p))
5515                return;
5516
5517        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5518            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5519                return; /* no tree diffs in patch format */
5520
5521        run_diff(p, o);
5522}
5523
5524static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5525                            struct diffstat_t *diffstat)
5526{
5527        if (diff_unmodified_pair(p))
5528                return;
5529
5530        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5531            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5532                return; /* no useful stat for tree diffs */
5533
5534        run_diffstat(p, o, diffstat);
5535}
5536
5537static void diff_flush_checkdiff(struct diff_filepair *p,
5538                struct diff_options *o)
5539{
5540        if (diff_unmodified_pair(p))
5541                return;
5542
5543        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5544            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5545                return; /* nothing to check in tree diffs */
5546
5547        run_checkdiff(p, o);
5548}
5549
5550int diff_queue_is_empty(void)
5551{
5552        struct diff_queue_struct *q = &diff_queued_diff;
5553        int i;
5554        for (i = 0; i < q->nr; i++)
5555                if (!diff_unmodified_pair(q->queue[i]))
5556                        return 0;
5557        return 1;
5558}
5559
5560#if DIFF_DEBUG
5561void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5562{
5563        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5564                x, one ? one : "",
5565                s->path,
5566                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5567                s->mode,
5568                s->oid_valid ? oid_to_hex(&s->oid) : "");
5569        fprintf(stderr, "queue[%d] %s size %lu\n",
5570                x, one ? one : "",
5571                s->size);
5572}
5573
5574void diff_debug_filepair(const struct diff_filepair *p, int i)
5575{
5576        diff_debug_filespec(p->one, i, "one");
5577        diff_debug_filespec(p->two, i, "two");
5578        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5579                p->score, p->status ? p->status : '?',
5580                p->one->rename_used, p->broken_pair);
5581}
5582
5583void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5584{
5585        int i;
5586        if (msg)
5587                fprintf(stderr, "%s\n", msg);
5588        fprintf(stderr, "q->nr = %d\n", q->nr);
5589        for (i = 0; i < q->nr; i++) {
5590                struct diff_filepair *p = q->queue[i];
5591                diff_debug_filepair(p, i);
5592        }
5593}
5594#endif
5595
5596static void diff_resolve_rename_copy(void)
5597{
5598        int i;
5599        struct diff_filepair *p;
5600        struct diff_queue_struct *q = &diff_queued_diff;
5601
5602        diff_debug_queue("resolve-rename-copy", q);
5603
5604        for (i = 0; i < q->nr; i++) {
5605                p = q->queue[i];
5606                p->status = 0; /* undecided */
5607                if (DIFF_PAIR_UNMERGED(p))
5608                        p->status = DIFF_STATUS_UNMERGED;
5609                else if (!DIFF_FILE_VALID(p->one))
5610                        p->status = DIFF_STATUS_ADDED;
5611                else if (!DIFF_FILE_VALID(p->two))
5612                        p->status = DIFF_STATUS_DELETED;
5613                else if (DIFF_PAIR_TYPE_CHANGED(p))
5614                        p->status = DIFF_STATUS_TYPE_CHANGED;
5615
5616                /* from this point on, we are dealing with a pair
5617                 * whose both sides are valid and of the same type, i.e.
5618                 * either in-place edit or rename/copy edit.
5619                 */
5620                else if (DIFF_PAIR_RENAME(p)) {
5621                        /*
5622                         * A rename might have re-connected a broken
5623                         * pair up, causing the pathnames to be the
5624                         * same again. If so, that's not a rename at
5625                         * all, just a modification..
5626                         *
5627                         * Otherwise, see if this source was used for
5628                         * multiple renames, in which case we decrement
5629                         * the count, and call it a copy.
5630                         */
5631                        if (!strcmp(p->one->path, p->two->path))
5632                                p->status = DIFF_STATUS_MODIFIED;
5633                        else if (--p->one->rename_used > 0)
5634                                p->status = DIFF_STATUS_COPIED;
5635                        else
5636                                p->status = DIFF_STATUS_RENAMED;
5637                }
5638                else if (!oideq(&p->one->oid, &p->two->oid) ||
5639                         p->one->mode != p->two->mode ||
5640                         p->one->dirty_submodule ||
5641                         p->two->dirty_submodule ||
5642                         is_null_oid(&p->one->oid))
5643                        p->status = DIFF_STATUS_MODIFIED;
5644                else {
5645                        /* This is a "no-change" entry and should not
5646                         * happen anymore, but prepare for broken callers.
5647                         */
5648                        error("feeding unmodified %s to diffcore",
5649                              p->one->path);
5650                        p->status = DIFF_STATUS_UNKNOWN;
5651                }
5652        }
5653        diff_debug_queue("resolve-rename-copy done", q);
5654}
5655
5656static int check_pair_status(struct diff_filepair *p)
5657{
5658        switch (p->status) {
5659        case DIFF_STATUS_UNKNOWN:
5660                return 0;
5661        case 0:
5662                die("internal error in diff-resolve-rename-copy");
5663        default:
5664                return 1;
5665        }
5666}
5667
5668static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5669{
5670        int fmt = opt->output_format;
5671
5672        if (fmt & DIFF_FORMAT_CHECKDIFF)
5673                diff_flush_checkdiff(p, opt);
5674        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5675                diff_flush_raw(p, opt);
5676        else if (fmt & DIFF_FORMAT_NAME) {
5677                const char *name_a, *name_b;
5678                name_a = p->two->path;
5679                name_b = NULL;
5680                strip_prefix(opt->prefix_length, &name_a, &name_b);
5681                fprintf(opt->file, "%s", diff_line_prefix(opt));
5682                write_name_quoted(name_a, opt->file, opt->line_termination);
5683        }
5684}
5685
5686static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5687{
5688        struct strbuf sb = STRBUF_INIT;
5689        if (fs->mode)
5690                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5691        else
5692                strbuf_addf(&sb, " %s ", newdelete);
5693
5694        quote_c_style(fs->path, &sb, NULL, 0);
5695        strbuf_addch(&sb, '\n');
5696        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5697                         sb.buf, sb.len, 0);
5698        strbuf_release(&sb);
5699}
5700
5701static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5702                int show_name)
5703{
5704        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5705                struct strbuf sb = STRBUF_INIT;
5706                strbuf_addf(&sb, " mode change %06o => %06o",
5707                            p->one->mode, p->two->mode);
5708                if (show_name) {
5709                        strbuf_addch(&sb, ' ');
5710                        quote_c_style(p->two->path, &sb, NULL, 0);
5711                }
5712                strbuf_addch(&sb, '\n');
5713                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5714                                 sb.buf, sb.len, 0);
5715                strbuf_release(&sb);
5716        }
5717}
5718
5719static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5720                struct diff_filepair *p)
5721{
5722        struct strbuf sb = STRBUF_INIT;
5723        struct strbuf names = STRBUF_INIT;
5724
5725        pprint_rename(&names, p->one->path, p->two->path);
5726        strbuf_addf(&sb, " %s %s (%d%%)\n",
5727                    renamecopy, names.buf, similarity_index(p));
5728        strbuf_release(&names);
5729        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5730                                 sb.buf, sb.len, 0);
5731        show_mode_change(opt, p, 0);
5732        strbuf_release(&sb);
5733}
5734
5735static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5736{
5737        switch(p->status) {
5738        case DIFF_STATUS_DELETED:
5739                show_file_mode_name(opt, "delete", p->one);
5740                break;
5741        case DIFF_STATUS_ADDED:
5742                show_file_mode_name(opt, "create", p->two);
5743                break;
5744        case DIFF_STATUS_COPIED:
5745                show_rename_copy(opt, "copy", p);
5746                break;
5747        case DIFF_STATUS_RENAMED:
5748                show_rename_copy(opt, "rename", p);
5749                break;
5750        default:
5751                if (p->score) {
5752                        struct strbuf sb = STRBUF_INIT;
5753                        strbuf_addstr(&sb, " rewrite ");
5754                        quote_c_style(p->two->path, &sb, NULL, 0);
5755                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5756                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5757                                         sb.buf, sb.len, 0);
5758                        strbuf_release(&sb);
5759                }
5760                show_mode_change(opt, p, !p->score);
5761                break;
5762        }
5763}
5764
5765struct patch_id_t {
5766        git_SHA_CTX *ctx;
5767        int patchlen;
5768};
5769
5770static int remove_space(char *line, int len)
5771{
5772        int i;
5773        char *dst = line;
5774        unsigned char c;
5775
5776        for (i = 0; i < len; i++)
5777                if (!isspace((c = line[i])))
5778                        *dst++ = c;
5779
5780        return dst - line;
5781}
5782
5783static void patch_id_consume(void *priv, char *line, unsigned long len)
5784{
5785        struct patch_id_t *data = priv;
5786        int new_len;
5787
5788        new_len = remove_space(line, len);
5789
5790        git_SHA1_Update(data->ctx, line, new_len);
5791        data->patchlen += new_len;
5792}
5793
5794static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5795{
5796        git_SHA1_Update(ctx, str, strlen(str));
5797}
5798
5799static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5800{
5801        /* large enough for 2^32 in octal */
5802        char buf[12];
5803        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5804        git_SHA1_Update(ctx, buf, len);
5805}
5806
5807/* returns 0 upon success, and writes result into sha1 */
5808static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5809{
5810        struct diff_queue_struct *q = &diff_queued_diff;
5811        int i;
5812        git_SHA_CTX ctx;
5813        struct patch_id_t data;
5814
5815        git_SHA1_Init(&ctx);
5816        memset(&data, 0, sizeof(struct patch_id_t));
5817        data.ctx = &ctx;
5818
5819        for (i = 0; i < q->nr; i++) {
5820                xpparam_t xpp;
5821                xdemitconf_t xecfg;
5822                mmfile_t mf1, mf2;
5823                struct diff_filepair *p = q->queue[i];
5824                int len1, len2;
5825
5826                memset(&xpp, 0, sizeof(xpp));
5827                memset(&xecfg, 0, sizeof(xecfg));
5828                if (p->status == 0)
5829                        return error("internal diff status error");
5830                if (p->status == DIFF_STATUS_UNKNOWN)
5831                        continue;
5832                if (diff_unmodified_pair(p))
5833                        continue;
5834                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5835                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5836                        continue;
5837                if (DIFF_PAIR_UNMERGED(p))
5838                        continue;
5839
5840                diff_fill_oid_info(p->one, options->repo->index);
5841                diff_fill_oid_info(p->two, options->repo->index);
5842
5843                len1 = remove_space(p->one->path, strlen(p->one->path));
5844                len2 = remove_space(p->two->path, strlen(p->two->path));
5845                patch_id_add_string(&ctx, "diff--git");
5846                patch_id_add_string(&ctx, "a/");
5847                git_SHA1_Update(&ctx, p->one->path, len1);
5848                patch_id_add_string(&ctx, "b/");
5849                git_SHA1_Update(&ctx, p->two->path, len2);
5850
5851                if (p->one->mode == 0) {
5852                        patch_id_add_string(&ctx, "newfilemode");
5853                        patch_id_add_mode(&ctx, p->two->mode);
5854                        patch_id_add_string(&ctx, "---/dev/null");
5855                        patch_id_add_string(&ctx, "+++b/");
5856                        git_SHA1_Update(&ctx, p->two->path, len2);
5857                } else if (p->two->mode == 0) {
5858                        patch_id_add_string(&ctx, "deletedfilemode");
5859                        patch_id_add_mode(&ctx, p->one->mode);
5860                        patch_id_add_string(&ctx, "---a/");
5861                        git_SHA1_Update(&ctx, p->one->path, len1);
5862                        patch_id_add_string(&ctx, "+++/dev/null");
5863                } else {
5864                        patch_id_add_string(&ctx, "---a/");
5865                        git_SHA1_Update(&ctx, p->one->path, len1);
5866                        patch_id_add_string(&ctx, "+++b/");
5867                        git_SHA1_Update(&ctx, p->two->path, len2);
5868                }
5869
5870                if (diff_header_only)
5871                        continue;
5872
5873                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5874                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5875                        return error("unable to read files to diff");
5876
5877                if (diff_filespec_is_binary(options->repo, p->one) ||
5878                    diff_filespec_is_binary(options->repo, p->two)) {
5879                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5880                                        GIT_SHA1_HEXSZ);
5881                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5882                                        GIT_SHA1_HEXSZ);
5883                        continue;
5884                }
5885
5886                xpp.flags = 0;
5887                xecfg.ctxlen = 3;
5888                xecfg.flags = 0;
5889                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
5890                                  patch_id_consume, &data, &xpp, &xecfg))
5891                        return error("unable to generate patch-id diff for %s",
5892                                     p->one->path);
5893        }
5894
5895        git_SHA1_Final(oid->hash, &ctx);
5896        return 0;
5897}
5898
5899int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5900{
5901        struct diff_queue_struct *q = &diff_queued_diff;
5902        int i;
5903        int result = diff_get_patch_id(options, oid, diff_header_only);
5904
5905        for (i = 0; i < q->nr; i++)
5906                diff_free_filepair(q->queue[i]);
5907
5908        free(q->queue);
5909        DIFF_QUEUE_CLEAR(q);
5910
5911        return result;
5912}
5913
5914static int is_summary_empty(const struct diff_queue_struct *q)
5915{
5916        int i;
5917
5918        for (i = 0; i < q->nr; i++) {
5919                const struct diff_filepair *p = q->queue[i];
5920
5921                switch (p->status) {
5922                case DIFF_STATUS_DELETED:
5923                case DIFF_STATUS_ADDED:
5924                case DIFF_STATUS_COPIED:
5925                case DIFF_STATUS_RENAMED:
5926                        return 0;
5927                default:
5928                        if (p->score)
5929                                return 0;
5930                        if (p->one->mode && p->two->mode &&
5931                            p->one->mode != p->two->mode)
5932                                return 0;
5933                        break;
5934                }
5935        }
5936        return 1;
5937}
5938
5939static const char rename_limit_warning[] =
5940N_("inexact rename detection was skipped due to too many files.");
5941
5942static const char degrade_cc_to_c_warning[] =
5943N_("only found copies from modified paths due to too many files.");
5944
5945static const char rename_limit_advice[] =
5946N_("you may want to set your %s variable to at least "
5947   "%d and retry the command.");
5948
5949void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5950{
5951        fflush(stdout);
5952        if (degraded_cc)
5953                warning(_(degrade_cc_to_c_warning));
5954        else if (needed)
5955                warning(_(rename_limit_warning));
5956        else
5957                return;
5958        if (0 < needed)
5959                warning(_(rename_limit_advice), varname, needed);
5960}
5961
5962static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5963{
5964        int i;
5965        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5966        struct diff_queue_struct *q = &diff_queued_diff;
5967
5968        if (WSEH_NEW & WS_RULE_MASK)
5969                BUG("WS rules bit mask overlaps with diff symbol flags");
5970
5971        if (o->color_moved)
5972                o->emitted_symbols = &esm;
5973
5974        for (i = 0; i < q->nr; i++) {
5975                struct diff_filepair *p = q->queue[i];
5976                if (check_pair_status(p))
5977                        diff_flush_patch(p, o);
5978        }
5979
5980        if (o->emitted_symbols) {
5981                if (o->color_moved) {
5982                        struct hashmap add_lines, del_lines;
5983
5984                        if (o->color_moved_ws_handling &
5985                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5986                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5987
5988                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5989                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5990
5991                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5992                        mark_color_as_moved(o, &add_lines, &del_lines);
5993                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5994                                dim_moved_lines(o);
5995
5996                        hashmap_free(&add_lines, 1);
5997                        hashmap_free(&del_lines, 1);
5998                }
5999
6000                for (i = 0; i < esm.nr; i++)
6001                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
6002
6003                for (i = 0; i < esm.nr; i++)
6004                        free((void *)esm.buf[i].line);
6005                esm.nr = 0;
6006
6007                o->emitted_symbols = NULL;
6008        }
6009}
6010
6011void diff_flush(struct diff_options *options)
6012{
6013        struct diff_queue_struct *q = &diff_queued_diff;
6014        int i, output_format = options->output_format;
6015        int separator = 0;
6016        int dirstat_by_line = 0;
6017
6018        /*
6019         * Order: raw, stat, summary, patch
6020         * or:    name/name-status/checkdiff (other bits clear)
6021         */
6022        if (!q->nr)
6023                goto free_queue;
6024
6025        if (output_format & (DIFF_FORMAT_RAW |
6026                             DIFF_FORMAT_NAME |
6027                             DIFF_FORMAT_NAME_STATUS |
6028                             DIFF_FORMAT_CHECKDIFF)) {
6029                for (i = 0; i < q->nr; i++) {
6030                        struct diff_filepair *p = q->queue[i];
6031                        if (check_pair_status(p))
6032                                flush_one_pair(p, options);
6033                }
6034                separator++;
6035        }
6036
6037        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
6038                dirstat_by_line = 1;
6039
6040        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
6041            dirstat_by_line) {
6042                struct diffstat_t diffstat;
6043
6044                memset(&diffstat, 0, sizeof(struct diffstat_t));
6045                for (i = 0; i < q->nr; i++) {
6046                        struct diff_filepair *p = q->queue[i];
6047                        if (check_pair_status(p))
6048                                diff_flush_stat(p, options, &diffstat);
6049                }
6050                if (output_format & DIFF_FORMAT_NUMSTAT)
6051                        show_numstat(&diffstat, options);
6052                if (output_format & DIFF_FORMAT_DIFFSTAT)
6053                        show_stats(&diffstat, options);
6054                if (output_format & DIFF_FORMAT_SHORTSTAT)
6055                        show_shortstats(&diffstat, options);
6056                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
6057                        show_dirstat_by_line(&diffstat, options);
6058                free_diffstat_info(&diffstat);
6059                separator++;
6060        }
6061        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
6062                show_dirstat(options);
6063
6064        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
6065                for (i = 0; i < q->nr; i++) {
6066                        diff_summary(options, q->queue[i]);
6067                }
6068                separator++;
6069        }
6070
6071        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
6072            options->flags.exit_with_status &&
6073            options->flags.diff_from_contents) {
6074                /*
6075                 * run diff_flush_patch for the exit status. setting
6076                 * options->file to /dev/null should be safe, because we
6077                 * aren't supposed to produce any output anyway.
6078                 */
6079                if (options->close_file)
6080                        fclose(options->file);
6081                options->file = xfopen("/dev/null", "w");
6082                options->close_file = 1;
6083                options->color_moved = 0;
6084                for (i = 0; i < q->nr; i++) {
6085                        struct diff_filepair *p = q->queue[i];
6086                        if (check_pair_status(p))
6087                                diff_flush_patch(p, options);
6088                        if (options->found_changes)
6089                                break;
6090                }
6091        }
6092
6093        if (output_format & DIFF_FORMAT_PATCH) {
6094                if (separator) {
6095                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
6096                        if (options->stat_sep)
6097                                /* attach patch instead of inline */
6098                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
6099                                                 NULL, 0, 0);
6100                }
6101
6102                diff_flush_patch_all_file_pairs(options);
6103        }
6104
6105        if (output_format & DIFF_FORMAT_CALLBACK)
6106                options->format_callback(q, options, options->format_callback_data);
6107
6108        for (i = 0; i < q->nr; i++)
6109                diff_free_filepair(q->queue[i]);
6110free_queue:
6111        free(q->queue);
6112        DIFF_QUEUE_CLEAR(q);
6113        if (options->close_file)
6114                fclose(options->file);
6115
6116        /*
6117         * Report the content-level differences with HAS_CHANGES;
6118         * diff_addremove/diff_change does not set the bit when
6119         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6120         */
6121        if (options->flags.diff_from_contents) {
6122                if (options->found_changes)
6123                        options->flags.has_changes = 1;
6124                else
6125                        options->flags.has_changes = 0;
6126        }
6127}
6128
6129static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6130{
6131        return (((p->status == DIFF_STATUS_MODIFIED) &&
6132                 ((p->score &&
6133                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6134                  (!p->score &&
6135                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6136                ((p->status != DIFF_STATUS_MODIFIED) &&
6137                 filter_bit_tst(p->status, options)));
6138}
6139
6140static void diffcore_apply_filter(struct diff_options *options)
6141{
6142        int i;
6143        struct diff_queue_struct *q = &diff_queued_diff;
6144        struct diff_queue_struct outq;
6145
6146        DIFF_QUEUE_CLEAR(&outq);
6147
6148        if (!options->filter)
6149                return;
6150
6151        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6152                int found;
6153                for (i = found = 0; !found && i < q->nr; i++) {
6154                        if (match_filter(options, q->queue[i]))
6155                                found++;
6156                }
6157                if (found)
6158                        return;
6159
6160                /* otherwise we will clear the whole queue
6161                 * by copying the empty outq at the end of this
6162                 * function, but first clear the current entries
6163                 * in the queue.
6164                 */
6165                for (i = 0; i < q->nr; i++)
6166                        diff_free_filepair(q->queue[i]);
6167        }
6168        else {
6169                /* Only the matching ones */
6170                for (i = 0; i < q->nr; i++) {
6171                        struct diff_filepair *p = q->queue[i];
6172                        if (match_filter(options, p))
6173                                diff_q(&outq, p);
6174                        else
6175                                diff_free_filepair(p);
6176                }
6177        }
6178        free(q->queue);
6179        *q = outq;
6180}
6181
6182/* Check whether two filespecs with the same mode and size are identical */
6183static int diff_filespec_is_identical(struct repository *r,
6184                                      struct diff_filespec *one,
6185                                      struct diff_filespec *two)
6186{
6187        if (S_ISGITLINK(one->mode))
6188                return 0;
6189        if (diff_populate_filespec(r, one, 0))
6190                return 0;
6191        if (diff_populate_filespec(r, two, 0))
6192                return 0;
6193        return !memcmp(one->data, two->data, one->size);
6194}
6195
6196static int diff_filespec_check_stat_unmatch(struct repository *r,
6197                                            struct diff_filepair *p)
6198{
6199        if (p->done_skip_stat_unmatch)
6200                return p->skip_stat_unmatch_result;
6201
6202        p->done_skip_stat_unmatch = 1;
6203        p->skip_stat_unmatch_result = 0;
6204        /*
6205         * 1. Entries that come from stat info dirtiness
6206         *    always have both sides (iow, not create/delete),
6207         *    one side of the object name is unknown, with
6208         *    the same mode and size.  Keep the ones that
6209         *    do not match these criteria.  They have real
6210         *    differences.
6211         *
6212         * 2. At this point, the file is known to be modified,
6213         *    with the same mode and size, and the object
6214         *    name of one side is unknown.  Need to inspect
6215         *    the identical contents.
6216         */
6217        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6218            !DIFF_FILE_VALID(p->two) ||
6219            (p->one->oid_valid && p->two->oid_valid) ||
6220            (p->one->mode != p->two->mode) ||
6221            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6222            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6223            (p->one->size != p->two->size) ||
6224            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6225                p->skip_stat_unmatch_result = 1;
6226        return p->skip_stat_unmatch_result;
6227}
6228
6229static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6230{
6231        int i;
6232        struct diff_queue_struct *q = &diff_queued_diff;
6233        struct diff_queue_struct outq;
6234        DIFF_QUEUE_CLEAR(&outq);
6235
6236        for (i = 0; i < q->nr; i++) {
6237                struct diff_filepair *p = q->queue[i];
6238
6239                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6240                        diff_q(&outq, p);
6241                else {
6242                        /*
6243                         * The caller can subtract 1 from skip_stat_unmatch
6244                         * to determine how many paths were dirty only
6245                         * due to stat info mismatch.
6246                         */
6247                        if (!diffopt->flags.no_index)
6248                                diffopt->skip_stat_unmatch++;
6249                        diff_free_filepair(p);
6250                }
6251        }
6252        free(q->queue);
6253        *q = outq;
6254}
6255
6256static int diffnamecmp(const void *a_, const void *b_)
6257{
6258        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6259        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6260        const char *name_a, *name_b;
6261
6262        name_a = a->one ? a->one->path : a->two->path;
6263        name_b = b->one ? b->one->path : b->two->path;
6264        return strcmp(name_a, name_b);
6265}
6266
6267void diffcore_fix_diff_index(void)
6268{
6269        struct diff_queue_struct *q = &diff_queued_diff;
6270        QSORT(q->queue, q->nr, diffnamecmp);
6271}
6272
6273void diffcore_std(struct diff_options *options)
6274{
6275        /* NOTE please keep the following in sync with diff_tree_combined() */
6276        if (options->skip_stat_unmatch)
6277                diffcore_skip_stat_unmatch(options);
6278        if (!options->found_follow) {
6279                /* See try_to_follow_renames() in tree-diff.c */
6280                if (options->break_opt != -1)
6281                        diffcore_break(options->repo,
6282                                       options->break_opt);
6283                if (options->detect_rename)
6284                        diffcore_rename(options);
6285                if (options->break_opt != -1)
6286                        diffcore_merge_broken();
6287        }
6288        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6289                diffcore_pickaxe(options);
6290        if (options->orderfile)
6291                diffcore_order(options->orderfile);
6292        if (!options->found_follow)
6293                /* See try_to_follow_renames() in tree-diff.c */
6294                diff_resolve_rename_copy();
6295        diffcore_apply_filter(options);
6296
6297        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6298                options->flags.has_changes = 1;
6299        else
6300                options->flags.has_changes = 0;
6301
6302        options->found_follow = 0;
6303}
6304
6305int diff_result_code(struct diff_options *opt, int status)
6306{
6307        int result = 0;
6308
6309        diff_warn_rename_limit("diff.renameLimit",
6310                               opt->needed_rename_limit,
6311                               opt->degraded_cc_to_c);
6312        if (!opt->flags.exit_with_status &&
6313            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6314                return status;
6315        if (opt->flags.exit_with_status &&
6316            opt->flags.has_changes)
6317                result |= 01;
6318        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6319            opt->flags.check_failed)
6320                result |= 02;
6321        return result;
6322}
6323
6324int diff_can_quit_early(struct diff_options *opt)
6325{
6326        return (opt->flags.quick &&
6327                !opt->filter &&
6328                opt->flags.has_changes);
6329}
6330
6331/*
6332 * Shall changes to this submodule be ignored?
6333 *
6334 * Submodule changes can be configured to be ignored separately for each path,
6335 * but that configuration can be overridden from the command line.
6336 */
6337static int is_submodule_ignored(const char *path, struct diff_options *options)
6338{
6339        int ignored = 0;
6340        struct diff_flags orig_flags = options->flags;
6341        if (!options->flags.override_submodule_config)
6342                set_diffopt_flags_from_submodule_config(options, path);
6343        if (options->flags.ignore_submodules)
6344                ignored = 1;
6345        options->flags = orig_flags;
6346        return ignored;
6347}
6348
6349void diff_addremove(struct diff_options *options,
6350                    int addremove, unsigned mode,
6351                    const struct object_id *oid,
6352                    int oid_valid,
6353                    const char *concatpath, unsigned dirty_submodule)
6354{
6355        struct diff_filespec *one, *two;
6356
6357        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6358                return;
6359
6360        /* This may look odd, but it is a preparation for
6361         * feeding "there are unchanged files which should
6362         * not produce diffs, but when you are doing copy
6363         * detection you would need them, so here they are"
6364         * entries to the diff-core.  They will be prefixed
6365         * with something like '=' or '*' (I haven't decided
6366         * which but should not make any difference).
6367         * Feeding the same new and old to diff_change()
6368         * also has the same effect.
6369         * Before the final output happens, they are pruned after
6370         * merged into rename/copy pairs as appropriate.
6371         */
6372        if (options->flags.reverse_diff)
6373                addremove = (addremove == '+' ? '-' :
6374                             addremove == '-' ? '+' : addremove);
6375
6376        if (options->prefix &&
6377            strncmp(concatpath, options->prefix, options->prefix_length))
6378                return;
6379
6380        one = alloc_filespec(concatpath);
6381        two = alloc_filespec(concatpath);
6382
6383        if (addremove != '+')
6384                fill_filespec(one, oid, oid_valid, mode);
6385        if (addremove != '-') {
6386                fill_filespec(two, oid, oid_valid, mode);
6387                two->dirty_submodule = dirty_submodule;
6388        }
6389
6390        diff_queue(&diff_queued_diff, one, two);
6391        if (!options->flags.diff_from_contents)
6392                options->flags.has_changes = 1;
6393}
6394
6395void diff_change(struct diff_options *options,
6396                 unsigned old_mode, unsigned new_mode,
6397                 const struct object_id *old_oid,
6398                 const struct object_id *new_oid,
6399                 int old_oid_valid, int new_oid_valid,
6400                 const char *concatpath,
6401                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6402{
6403        struct diff_filespec *one, *two;
6404        struct diff_filepair *p;
6405
6406        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6407            is_submodule_ignored(concatpath, options))
6408                return;
6409
6410        if (options->flags.reverse_diff) {
6411                SWAP(old_mode, new_mode);
6412                SWAP(old_oid, new_oid);
6413                SWAP(old_oid_valid, new_oid_valid);
6414                SWAP(old_dirty_submodule, new_dirty_submodule);
6415        }
6416
6417        if (options->prefix &&
6418            strncmp(concatpath, options->prefix, options->prefix_length))
6419                return;
6420
6421        one = alloc_filespec(concatpath);
6422        two = alloc_filespec(concatpath);
6423        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6424        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6425        one->dirty_submodule = old_dirty_submodule;
6426        two->dirty_submodule = new_dirty_submodule;
6427        p = diff_queue(&diff_queued_diff, one, two);
6428
6429        if (options->flags.diff_from_contents)
6430                return;
6431
6432        if (options->flags.quick && options->skip_stat_unmatch &&
6433            !diff_filespec_check_stat_unmatch(options->repo, p))
6434                return;
6435
6436        options->flags.has_changes = 1;
6437}
6438
6439struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6440{
6441        struct diff_filepair *pair;
6442        struct diff_filespec *one, *two;
6443
6444        if (options->prefix &&
6445            strncmp(path, options->prefix, options->prefix_length))
6446                return NULL;
6447
6448        one = alloc_filespec(path);
6449        two = alloc_filespec(path);
6450        pair = diff_queue(&diff_queued_diff, one, two);
6451        pair->is_unmerged = 1;
6452        return pair;
6453}
6454
6455static char *run_textconv(struct repository *r,
6456                          const char *pgm,
6457                          struct diff_filespec *spec,
6458                          size_t *outsize)
6459{
6460        struct diff_tempfile *temp;
6461        const char *argv[3];
6462        const char **arg = argv;
6463        struct child_process child = CHILD_PROCESS_INIT;
6464        struct strbuf buf = STRBUF_INIT;
6465        int err = 0;
6466
6467        temp = prepare_temp_file(r, spec->path, spec);
6468        *arg++ = pgm;
6469        *arg++ = temp->name;
6470        *arg = NULL;
6471
6472        child.use_shell = 1;
6473        child.argv = argv;
6474        child.out = -1;
6475        if (start_command(&child)) {
6476                remove_tempfile();
6477                return NULL;
6478        }
6479
6480        if (strbuf_read(&buf, child.out, 0) < 0)
6481                err = error("error reading from textconv command '%s'", pgm);
6482        close(child.out);
6483
6484        if (finish_command(&child) || err) {
6485                strbuf_release(&buf);
6486                remove_tempfile();
6487                return NULL;
6488        }
6489        remove_tempfile();
6490
6491        return strbuf_detach(&buf, outsize);
6492}
6493
6494size_t fill_textconv(struct repository *r,
6495                     struct userdiff_driver *driver,
6496                     struct diff_filespec *df,
6497                     char **outbuf)
6498{
6499        size_t size;
6500
6501        if (!driver) {
6502                if (!DIFF_FILE_VALID(df)) {
6503                        *outbuf = "";
6504                        return 0;
6505                }
6506                if (diff_populate_filespec(r, df, 0))
6507                        die("unable to read files to diff");
6508                *outbuf = df->data;
6509                return df->size;
6510        }
6511
6512        if (!driver->textconv)
6513                BUG("fill_textconv called with non-textconv driver");
6514
6515        if (driver->textconv_cache && df->oid_valid) {
6516                *outbuf = notes_cache_get(driver->textconv_cache,
6517                                          &df->oid,
6518                                          &size);
6519                if (*outbuf)
6520                        return size;
6521        }
6522
6523        *outbuf = run_textconv(r, driver->textconv, df, &size);
6524        if (!*outbuf)
6525                die("unable to read files to diff");
6526
6527        if (driver->textconv_cache && df->oid_valid) {
6528                /* ignore errors, as we might be in a readonly repository */
6529                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6530                                size);
6531                /*
6532                 * we could save up changes and flush them all at the end,
6533                 * but we would need an extra call after all diffing is done.
6534                 * Since generating a cache entry is the slow path anyway,
6535                 * this extra overhead probably isn't a big deal.
6536                 */
6537                notes_cache_write(driver->textconv_cache);
6538        }
6539
6540        return size;
6541}
6542
6543int textconv_object(struct repository *r,
6544                    const char *path,
6545                    unsigned mode,
6546                    const struct object_id *oid,
6547                    int oid_valid,
6548                    char **buf,
6549                    unsigned long *buf_size)
6550{
6551        struct diff_filespec *df;
6552        struct userdiff_driver *textconv;
6553
6554        df = alloc_filespec(path);
6555        fill_filespec(df, oid, oid_valid, mode);
6556        textconv = get_textconv(r, df);
6557        if (!textconv) {
6558                free_filespec(df);
6559                return 0;
6560        }
6561
6562        *buf_size = fill_textconv(r, textconv, df, buf);
6563        free_filespec(df);
6564        return 1;
6565}
6566
6567void setup_diff_pager(struct diff_options *opt)
6568{
6569        /*
6570         * If the user asked for our exit code, then either they want --quiet
6571         * or --exit-code. We should definitely not bother with a pager in the
6572         * former case, as we will generate no output. Since we still properly
6573         * report our exit code even when a pager is run, we _could_ run a
6574         * pager with --exit-code. But since we have not done so historically,
6575         * and because it is easy to find people oneline advising "git diff
6576         * --exit-code" in hooks and other scripts, we do not do so.
6577         */
6578        if (!opt->flags.exit_with_status &&
6579            check_pager_config("diff") != 0)
6580                setup_pager();
6581}