diff.con commit completion: add more parameter value completion (5a59a23)
   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 "help.h"
  27
  28#ifdef NO_FAST_WORKING_DIRECTORY
  29#define FAST_WORKING_DIRECTORY 0
  30#else
  31#define FAST_WORKING_DIRECTORY 1
  32#endif
  33
  34static int diff_detect_rename_default;
  35static int diff_indent_heuristic = 1;
  36static int diff_rename_limit_default = 400;
  37static int diff_suppress_blank_empty;
  38static int diff_use_color_default = -1;
  39static int diff_color_moved_default;
  40static int diff_color_moved_ws_default;
  41static int diff_context_default = 3;
  42static int diff_interhunk_context_default;
  43static const char *diff_word_regex_cfg;
  44static const char *external_diff_cmd_cfg;
  45static const char *diff_order_file_cfg;
  46int diff_auto_refresh_index = 1;
  47static int diff_mnemonic_prefix;
  48static int diff_no_prefix;
  49static int diff_stat_graph_width;
  50static int diff_dirstat_permille_default = 30;
  51static struct diff_options default_diff_options;
  52static long diff_algorithm;
  53static unsigned ws_error_highlight_default = WSEH_NEW;
  54
  55static char diff_colors[][COLOR_MAXLEN] = {
  56        GIT_COLOR_RESET,
  57        GIT_COLOR_NORMAL,       /* CONTEXT */
  58        GIT_COLOR_BOLD,         /* METAINFO */
  59        GIT_COLOR_CYAN,         /* FRAGINFO */
  60        GIT_COLOR_RED,          /* OLD */
  61        GIT_COLOR_GREEN,        /* NEW */
  62        GIT_COLOR_YELLOW,       /* COMMIT */
  63        GIT_COLOR_BG_RED,       /* WHITESPACE */
  64        GIT_COLOR_NORMAL,       /* FUNCINFO */
  65        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  66        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  67        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  68        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  69        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  70        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  71        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  72        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  73        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  74        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  75        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  76        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  77        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  78        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  79};
  80
  81static const char *color_diff_slots[] = {
  82        [DIFF_CONTEXT]                = "context",
  83        [DIFF_METAINFO]               = "meta",
  84        [DIFF_FRAGINFO]               = "frag",
  85        [DIFF_FILE_OLD]               = "old",
  86        [DIFF_FILE_NEW]               = "new",
  87        [DIFF_COMMIT]                 = "commit",
  88        [DIFF_WHITESPACE]             = "whitespace",
  89        [DIFF_FUNCINFO]               = "func",
  90        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  91        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  92        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  93        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  94        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  95        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  96        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  97        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  98        [DIFF_CONTEXT_DIM]            = "contextDimmed",
  99        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 100        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 101        [DIFF_CONTEXT_BOLD]           = "contextBold",
 102        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 103        [DIFF_FILE_NEW_BOLD]          = "newBold",
 104};
 105
 106static NORETURN void die_want_option(const char *option_name)
 107{
 108        die(_("option '%s' requires a value"), option_name);
 109}
 110
 111define_list_config_array_extra(color_diff_slots, {"plain"});
 112
 113static int parse_diff_color_slot(const char *var)
 114{
 115        if (!strcasecmp(var, "plain"))
 116                return DIFF_CONTEXT;
 117        return LOOKUP_CONFIG(color_diff_slots, var);
 118}
 119
 120static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 121                                struct strbuf *errmsg)
 122{
 123        char *params_copy = xstrdup(params_string);
 124        struct string_list params = STRING_LIST_INIT_NODUP;
 125        int ret = 0;
 126        int i;
 127
 128        if (*params_copy)
 129                string_list_split_in_place(&params, params_copy, ',', -1);
 130        for (i = 0; i < params.nr; i++) {
 131                const char *p = params.items[i].string;
 132                if (!strcmp(p, "changes")) {
 133                        options->flags.dirstat_by_line = 0;
 134                        options->flags.dirstat_by_file = 0;
 135                } else if (!strcmp(p, "lines")) {
 136                        options->flags.dirstat_by_line = 1;
 137                        options->flags.dirstat_by_file = 0;
 138                } else if (!strcmp(p, "files")) {
 139                        options->flags.dirstat_by_line = 0;
 140                        options->flags.dirstat_by_file = 1;
 141                } else if (!strcmp(p, "noncumulative")) {
 142                        options->flags.dirstat_cumulative = 0;
 143                } else if (!strcmp(p, "cumulative")) {
 144                        options->flags.dirstat_cumulative = 1;
 145                } else if (isdigit(*p)) {
 146                        char *end;
 147                        int permille = strtoul(p, &end, 10) * 10;
 148                        if (*end == '.' && isdigit(*++end)) {
 149                                /* only use first digit */
 150                                permille += *end - '0';
 151                                /* .. and ignore any further digits */
 152                                while (isdigit(*++end))
 153                                        ; /* nothing */
 154                        }
 155                        if (!*end)
 156                                options->dirstat_permille = permille;
 157                        else {
 158                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 159                                            p);
 160                                ret++;
 161                        }
 162                } else {
 163                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 164                        ret++;
 165                }
 166
 167        }
 168        string_list_clear(&params, 0);
 169        free(params_copy);
 170        return ret;
 171}
 172
 173static int parse_submodule_params(struct diff_options *options, const char *value)
 174{
 175        if (!strcmp(value, "log"))
 176                options->submodule_format = DIFF_SUBMODULE_LOG;
 177        else if (!strcmp(value, "short"))
 178                options->submodule_format = DIFF_SUBMODULE_SHORT;
 179        else if (!strcmp(value, "diff"))
 180                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 181        /*
 182         * Please update $__git_diff_submodule_formats in
 183         * git-completion.bash when you add new formats.
 184         */
 185        else
 186                return -1;
 187        return 0;
 188}
 189
 190int git_config_rename(const char *var, const char *value)
 191{
 192        if (!value)
 193                return DIFF_DETECT_RENAME;
 194        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 195                return  DIFF_DETECT_COPY;
 196        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 197}
 198
 199long parse_algorithm_value(const char *value)
 200{
 201        if (!value)
 202                return -1;
 203        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 204                return 0;
 205        else if (!strcasecmp(value, "minimal"))
 206                return XDF_NEED_MINIMAL;
 207        else if (!strcasecmp(value, "patience"))
 208                return XDF_PATIENCE_DIFF;
 209        else if (!strcasecmp(value, "histogram"))
 210                return XDF_HISTOGRAM_DIFF;
 211        /*
 212         * Please update $__git_diff_algorithms in git-completion.bash
 213         * when you add new algorithms.
 214         */
 215        return -1;
 216}
 217
 218static int parse_one_token(const char **arg, const char *token)
 219{
 220        const char *rest;
 221        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 222                *arg = rest;
 223                return 1;
 224        }
 225        return 0;
 226}
 227
 228static int parse_ws_error_highlight(const char *arg)
 229{
 230        const char *orig_arg = arg;
 231        unsigned val = 0;
 232
 233        while (*arg) {
 234                if (parse_one_token(&arg, "none"))
 235                        val = 0;
 236                else if (parse_one_token(&arg, "default"))
 237                        val = WSEH_NEW;
 238                else if (parse_one_token(&arg, "all"))
 239                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 240                else if (parse_one_token(&arg, "new"))
 241                        val |= WSEH_NEW;
 242                else if (parse_one_token(&arg, "old"))
 243                        val |= WSEH_OLD;
 244                else if (parse_one_token(&arg, "context"))
 245                        val |= WSEH_CONTEXT;
 246                else {
 247                        return -1 - (int)(arg - orig_arg);
 248                }
 249                if (*arg)
 250                        arg++;
 251        }
 252        return val;
 253}
 254
 255/*
 256 * These are to give UI layer defaults.
 257 * The core-level commands such as git-diff-files should
 258 * never be affected by the setting of diff.renames
 259 * the user happens to have in the configuration file.
 260 */
 261void init_diff_ui_defaults(void)
 262{
 263        diff_detect_rename_default = DIFF_DETECT_RENAME;
 264}
 265
 266int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 267{
 268        if (!strcmp(var, "diff.indentheuristic"))
 269                diff_indent_heuristic = git_config_bool(var, value);
 270        return 0;
 271}
 272
 273static int parse_color_moved(const char *arg)
 274{
 275        switch (git_parse_maybe_bool(arg)) {
 276        case 0:
 277                return COLOR_MOVED_NO;
 278        case 1:
 279                return COLOR_MOVED_DEFAULT;
 280        default:
 281                break;
 282        }
 283
 284        if (!strcmp(arg, "no"))
 285                return COLOR_MOVED_NO;
 286        else if (!strcmp(arg, "plain"))
 287                return COLOR_MOVED_PLAIN;
 288        else if (!strcmp(arg, "blocks"))
 289                return COLOR_MOVED_BLOCKS;
 290        else if (!strcmp(arg, "zebra"))
 291                return COLOR_MOVED_ZEBRA;
 292        else if (!strcmp(arg, "default"))
 293                return COLOR_MOVED_DEFAULT;
 294        else if (!strcmp(arg, "dimmed-zebra"))
 295                return COLOR_MOVED_ZEBRA_DIM;
 296        else if (!strcmp(arg, "dimmed_zebra"))
 297                return COLOR_MOVED_ZEBRA_DIM;
 298        else
 299                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 300}
 301
 302static unsigned parse_color_moved_ws(const char *arg)
 303{
 304        int ret = 0;
 305        struct string_list l = STRING_LIST_INIT_DUP;
 306        struct string_list_item *i;
 307
 308        string_list_split(&l, arg, ',', -1);
 309
 310        for_each_string_list_item(i, &l) {
 311                struct strbuf sb = STRBUF_INIT;
 312                strbuf_addstr(&sb, i->string);
 313                strbuf_trim(&sb);
 314
 315                if (!strcmp(sb.buf, "no"))
 316                        ret = 0;
 317                else if (!strcmp(sb.buf, "ignore-space-change"))
 318                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 319                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 320                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 321                else if (!strcmp(sb.buf, "ignore-all-space"))
 322                        ret |= XDF_IGNORE_WHITESPACE;
 323                else if (!strcmp(sb.buf, "allow-indentation-change"))
 324                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 325                else {
 326                        ret |= COLOR_MOVED_WS_ERROR;
 327                        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);
 328                }
 329
 330                strbuf_release(&sb);
 331        }
 332
 333        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 334            (ret & XDF_WHITESPACE_FLAGS)) {
 335                error(_("color-moved-ws: allow-indentation-change cannot be combined with other whitespace modes"));
 336                ret |= COLOR_MOVED_WS_ERROR;
 337        }
 338
 339        string_list_clear(&l, 0);
 340
 341        return ret;
 342}
 343
 344int git_diff_ui_config(const char *var, const char *value, void *cb)
 345{
 346        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 347                diff_use_color_default = git_config_colorbool(var, value);
 348                return 0;
 349        }
 350        if (!strcmp(var, "diff.colormoved")) {
 351                int cm = parse_color_moved(value);
 352                if (cm < 0)
 353                        return -1;
 354                diff_color_moved_default = cm;
 355                return 0;
 356        }
 357        if (!strcmp(var, "diff.colormovedws")) {
 358                unsigned cm = parse_color_moved_ws(value);
 359                if (cm & COLOR_MOVED_WS_ERROR)
 360                        return -1;
 361                diff_color_moved_ws_default = cm;
 362                return 0;
 363        }
 364        if (!strcmp(var, "diff.context")) {
 365                diff_context_default = git_config_int(var, value);
 366                if (diff_context_default < 0)
 367                        return -1;
 368                return 0;
 369        }
 370        if (!strcmp(var, "diff.interhunkcontext")) {
 371                diff_interhunk_context_default = git_config_int(var, value);
 372                if (diff_interhunk_context_default < 0)
 373                        return -1;
 374                return 0;
 375        }
 376        if (!strcmp(var, "diff.renames")) {
 377                diff_detect_rename_default = git_config_rename(var, value);
 378                return 0;
 379        }
 380        if (!strcmp(var, "diff.autorefreshindex")) {
 381                diff_auto_refresh_index = git_config_bool(var, value);
 382                return 0;
 383        }
 384        if (!strcmp(var, "diff.mnemonicprefix")) {
 385                diff_mnemonic_prefix = git_config_bool(var, value);
 386                return 0;
 387        }
 388        if (!strcmp(var, "diff.noprefix")) {
 389                diff_no_prefix = git_config_bool(var, value);
 390                return 0;
 391        }
 392        if (!strcmp(var, "diff.statgraphwidth")) {
 393                diff_stat_graph_width = git_config_int(var, value);
 394                return 0;
 395        }
 396        if (!strcmp(var, "diff.external"))
 397                return git_config_string(&external_diff_cmd_cfg, var, value);
 398        if (!strcmp(var, "diff.wordregex"))
 399                return git_config_string(&diff_word_regex_cfg, var, value);
 400        if (!strcmp(var, "diff.orderfile"))
 401                return git_config_pathname(&diff_order_file_cfg, var, value);
 402
 403        if (!strcmp(var, "diff.ignoresubmodules"))
 404                handle_ignore_submodules_arg(&default_diff_options, value);
 405
 406        if (!strcmp(var, "diff.submodule")) {
 407                if (parse_submodule_params(&default_diff_options, value))
 408                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 409                                value);
 410                return 0;
 411        }
 412
 413        if (!strcmp(var, "diff.algorithm")) {
 414                diff_algorithm = parse_algorithm_value(value);
 415                if (diff_algorithm < 0)
 416                        return -1;
 417                return 0;
 418        }
 419
 420        if (!strcmp(var, "diff.wserrorhighlight")) {
 421                int val = parse_ws_error_highlight(value);
 422                if (val < 0)
 423                        return -1;
 424                ws_error_highlight_default = val;
 425                return 0;
 426        }
 427
 428        if (git_color_config(var, value, cb) < 0)
 429                return -1;
 430
 431        return git_diff_basic_config(var, value, cb);
 432}
 433
 434int git_diff_basic_config(const char *var, const char *value, void *cb)
 435{
 436        const char *name;
 437
 438        if (!strcmp(var, "diff.renamelimit")) {
 439                diff_rename_limit_default = git_config_int(var, value);
 440                return 0;
 441        }
 442
 443        if (userdiff_config(var, value) < 0)
 444                return -1;
 445
 446        if (skip_prefix(var, "diff.color.", &name) ||
 447            skip_prefix(var, "color.diff.", &name)) {
 448                int slot = parse_diff_color_slot(name);
 449                if (slot < 0)
 450                        return 0;
 451                if (!value)
 452                        return config_error_nonbool(var);
 453                return color_parse(value, diff_colors[slot]);
 454        }
 455
 456        /* like GNU diff's --suppress-blank-empty option  */
 457        if (!strcmp(var, "diff.suppressblankempty") ||
 458                        /* for backwards compatibility */
 459                        !strcmp(var, "diff.suppress-blank-empty")) {
 460                diff_suppress_blank_empty = git_config_bool(var, value);
 461                return 0;
 462        }
 463
 464        if (!strcmp(var, "diff.dirstat")) {
 465                struct strbuf errmsg = STRBUF_INIT;
 466                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 467                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 468                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 469                                errmsg.buf);
 470                strbuf_release(&errmsg);
 471                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 472                return 0;
 473        }
 474
 475        if (git_diff_heuristic_config(var, value, cb) < 0)
 476                return -1;
 477
 478        return git_default_config(var, value, cb);
 479}
 480
 481static char *quote_two(const char *one, const char *two)
 482{
 483        int need_one = quote_c_style(one, NULL, NULL, 1);
 484        int need_two = quote_c_style(two, NULL, NULL, 1);
 485        struct strbuf res = STRBUF_INIT;
 486
 487        if (need_one + need_two) {
 488                strbuf_addch(&res, '"');
 489                quote_c_style(one, &res, NULL, 1);
 490                quote_c_style(two, &res, NULL, 1);
 491                strbuf_addch(&res, '"');
 492        } else {
 493                strbuf_addstr(&res, one);
 494                strbuf_addstr(&res, two);
 495        }
 496        return strbuf_detach(&res, NULL);
 497}
 498
 499static const char *external_diff(void)
 500{
 501        static const char *external_diff_cmd = NULL;
 502        static int done_preparing = 0;
 503
 504        if (done_preparing)
 505                return external_diff_cmd;
 506        external_diff_cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF"));
 507        if (!external_diff_cmd)
 508                external_diff_cmd = external_diff_cmd_cfg;
 509        done_preparing = 1;
 510        return external_diff_cmd;
 511}
 512
 513/*
 514 * Keep track of files used for diffing. Sometimes such an entry
 515 * refers to a temporary file, sometimes to an existing file, and
 516 * sometimes to "/dev/null".
 517 */
 518static struct diff_tempfile {
 519        /*
 520         * filename external diff should read from, or NULL if this
 521         * entry is currently not in use:
 522         */
 523        const char *name;
 524
 525        char hex[GIT_MAX_HEXSZ + 1];
 526        char mode[10];
 527
 528        /*
 529         * If this diff_tempfile instance refers to a temporary file,
 530         * this tempfile object is used to manage its lifetime.
 531         */
 532        struct tempfile *tempfile;
 533} diff_temp[2];
 534
 535struct emit_callback {
 536        int color_diff;
 537        unsigned ws_rule;
 538        int blank_at_eof_in_preimage;
 539        int blank_at_eof_in_postimage;
 540        int lno_in_preimage;
 541        int lno_in_postimage;
 542        const char **label_path;
 543        struct diff_words_data *diff_words;
 544        struct diff_options *opt;
 545        struct strbuf *header;
 546};
 547
 548static int count_lines(const char *data, int size)
 549{
 550        int count, ch, completely_empty = 1, nl_just_seen = 0;
 551        count = 0;
 552        while (0 < size--) {
 553                ch = *data++;
 554                if (ch == '\n') {
 555                        count++;
 556                        nl_just_seen = 1;
 557                        completely_empty = 0;
 558                }
 559                else {
 560                        nl_just_seen = 0;
 561                        completely_empty = 0;
 562                }
 563        }
 564        if (completely_empty)
 565                return 0;
 566        if (!nl_just_seen)
 567                count++; /* no trailing newline */
 568        return count;
 569}
 570
 571static int fill_mmfile(struct repository *r, mmfile_t *mf,
 572                       struct diff_filespec *one)
 573{
 574        if (!DIFF_FILE_VALID(one)) {
 575                mf->ptr = (char *)""; /* does not matter */
 576                mf->size = 0;
 577                return 0;
 578        }
 579        else if (diff_populate_filespec(r, one, 0))
 580                return -1;
 581
 582        mf->ptr = one->data;
 583        mf->size = one->size;
 584        return 0;
 585}
 586
 587/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 588static unsigned long diff_filespec_size(struct repository *r,
 589                                        struct diff_filespec *one)
 590{
 591        if (!DIFF_FILE_VALID(one))
 592                return 0;
 593        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 594        return one->size;
 595}
 596
 597static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 598{
 599        char *ptr = mf->ptr;
 600        long size = mf->size;
 601        int cnt = 0;
 602
 603        if (!size)
 604                return cnt;
 605        ptr += size - 1; /* pointing at the very end */
 606        if (*ptr != '\n')
 607                ; /* incomplete line */
 608        else
 609                ptr--; /* skip the last LF */
 610        while (mf->ptr < ptr) {
 611                char *prev_eol;
 612                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 613                        if (*prev_eol == '\n')
 614                                break;
 615                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 616                        break;
 617                cnt++;
 618                ptr = prev_eol - 1;
 619        }
 620        return cnt;
 621}
 622
 623static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 624                               struct emit_callback *ecbdata)
 625{
 626        int l1, l2, at;
 627        unsigned ws_rule = ecbdata->ws_rule;
 628        l1 = count_trailing_blank(mf1, ws_rule);
 629        l2 = count_trailing_blank(mf2, ws_rule);
 630        if (l2 <= l1) {
 631                ecbdata->blank_at_eof_in_preimage = 0;
 632                ecbdata->blank_at_eof_in_postimage = 0;
 633                return;
 634        }
 635        at = count_lines(mf1->ptr, mf1->size);
 636        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 637
 638        at = count_lines(mf2->ptr, mf2->size);
 639        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 640}
 641
 642static void emit_line_0(struct diff_options *o,
 643                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 644                        int first, const char *line, int len)
 645{
 646        int has_trailing_newline, has_trailing_carriage_return;
 647        int needs_reset = 0; /* at the end of the line */
 648        FILE *file = o->file;
 649
 650        fputs(diff_line_prefix(o), file);
 651
 652        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 653        if (has_trailing_newline)
 654                len--;
 655
 656        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 657        if (has_trailing_carriage_return)
 658                len--;
 659
 660        if (!len && !first)
 661                goto end_of_line;
 662
 663        if (reverse && want_color(o->use_color)) {
 664                fputs(GIT_COLOR_REVERSE, file);
 665                needs_reset = 1;
 666        }
 667
 668        if (set_sign) {
 669                fputs(set_sign, file);
 670                needs_reset = 1;
 671        }
 672
 673        if (first)
 674                fputc(first, file);
 675
 676        if (!len)
 677                goto end_of_line;
 678
 679        if (set) {
 680                if (set_sign && set != set_sign)
 681                        fputs(reset, file);
 682                fputs(set, file);
 683                needs_reset = 1;
 684        }
 685        fwrite(line, len, 1, file);
 686        needs_reset = 1; /* 'line' may contain color codes. */
 687
 688end_of_line:
 689        if (needs_reset)
 690                fputs(reset, file);
 691        if (has_trailing_carriage_return)
 692                fputc('\r', file);
 693        if (has_trailing_newline)
 694                fputc('\n', file);
 695}
 696
 697static void emit_line(struct diff_options *o, const char *set, const char *reset,
 698                      const char *line, int len)
 699{
 700        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 701}
 702
 703enum diff_symbol {
 704        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 705        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 706        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 707        DIFF_SYMBOL_BINARY_DIFF_BODY,
 708        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 709        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 710        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 711        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 712        DIFF_SYMBOL_STATS_LINE,
 713        DIFF_SYMBOL_WORD_DIFF,
 714        DIFF_SYMBOL_STAT_SEP,
 715        DIFF_SYMBOL_SUMMARY,
 716        DIFF_SYMBOL_SUBMODULE_ADD,
 717        DIFF_SYMBOL_SUBMODULE_DEL,
 718        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 719        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 720        DIFF_SYMBOL_SUBMODULE_HEADER,
 721        DIFF_SYMBOL_SUBMODULE_ERROR,
 722        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 723        DIFF_SYMBOL_REWRITE_DIFF,
 724        DIFF_SYMBOL_BINARY_FILES,
 725        DIFF_SYMBOL_HEADER,
 726        DIFF_SYMBOL_FILEPAIR_PLUS,
 727        DIFF_SYMBOL_FILEPAIR_MINUS,
 728        DIFF_SYMBOL_WORDS_PORCELAIN,
 729        DIFF_SYMBOL_WORDS,
 730        DIFF_SYMBOL_CONTEXT,
 731        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 732        DIFF_SYMBOL_PLUS,
 733        DIFF_SYMBOL_MINUS,
 734        DIFF_SYMBOL_NO_LF_EOF,
 735        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 736        DIFF_SYMBOL_CONTEXT_MARKER,
 737        DIFF_SYMBOL_SEPARATOR
 738};
 739/*
 740 * Flags for content lines:
 741 * 0..12 are whitespace rules
 742 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 743 * 16 is marking if the line is blank at EOF
 744 */
 745#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 746#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 747#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 748#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 749#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 750
 751/*
 752 * This struct is used when we need to buffer the output of the diff output.
 753 *
 754 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 755 * into the pre/post image file. This pointer could be a union with the
 756 * line pointer. By storing an offset into the file instead of the literal line,
 757 * we can decrease the memory footprint for the buffered output. At first we
 758 * may want to only have indirection for the content lines, but we could also
 759 * enhance the state for emitting prefabricated lines, e.g. the similarity
 760 * score line or hunk/file headers would only need to store a number or path
 761 * and then the output can be constructed later on depending on state.
 762 */
 763struct emitted_diff_symbol {
 764        const char *line;
 765        int len;
 766        int flags;
 767        int indent_off;   /* Offset to first non-whitespace character */
 768        int indent_width; /* The visual width of the indentation */
 769        enum diff_symbol s;
 770};
 771#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 772
 773struct emitted_diff_symbols {
 774        struct emitted_diff_symbol *buf;
 775        int nr, alloc;
 776};
 777#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 778
 779static void append_emitted_diff_symbol(struct diff_options *o,
 780                                       struct emitted_diff_symbol *e)
 781{
 782        struct emitted_diff_symbol *f;
 783
 784        ALLOC_GROW(o->emitted_symbols->buf,
 785                   o->emitted_symbols->nr + 1,
 786                   o->emitted_symbols->alloc);
 787        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 788
 789        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 790        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 791}
 792
 793struct moved_entry {
 794        struct hashmap_entry ent;
 795        const struct emitted_diff_symbol *es;
 796        struct moved_entry *next_line;
 797};
 798
 799struct moved_block {
 800        struct moved_entry *match;
 801        int wsd; /* The whitespace delta of this block */
 802};
 803
 804static void moved_block_clear(struct moved_block *b)
 805{
 806        memset(b, 0, sizeof(*b));
 807}
 808
 809#define INDENT_BLANKLINE INT_MIN
 810
 811static void fill_es_indent_data(struct emitted_diff_symbol *es)
 812{
 813        unsigned int off = 0, i;
 814        int width = 0, tab_width = es->flags & WS_TAB_WIDTH_MASK;
 815        const char *s = es->line;
 816        const int len = es->len;
 817
 818        /* skip any \v \f \r at start of indentation */
 819        while (s[off] == '\f' || s[off] == '\v' ||
 820               (s[off] == '\r' && off < len - 1))
 821                off++;
 822
 823        /* calculate the visual width of indentation */
 824        while(1) {
 825                if (s[off] == ' ') {
 826                        width++;
 827                        off++;
 828                } else if (s[off] == '\t') {
 829                        width += tab_width - (width % tab_width);
 830                        while (s[++off] == '\t')
 831                                width += tab_width;
 832                } else {
 833                        break;
 834                }
 835        }
 836
 837        /* check if this line is blank */
 838        for (i = off; i < len; i++)
 839                if (!isspace(s[i]))
 840                    break;
 841
 842        if (i == len) {
 843                es->indent_width = INDENT_BLANKLINE;
 844                es->indent_off = len;
 845        } else {
 846                es->indent_off = off;
 847                es->indent_width = width;
 848        }
 849}
 850
 851static int compute_ws_delta(const struct emitted_diff_symbol *a,
 852                            const struct emitted_diff_symbol *b,
 853                            int *out)
 854{
 855        int a_len = a->len,
 856            b_len = b->len,
 857            a_off = a->indent_off,
 858            a_width = a->indent_width,
 859            b_off = b->indent_off,
 860            b_width = b->indent_width;
 861        int delta;
 862
 863        if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
 864                *out = INDENT_BLANKLINE;
 865                return 1;
 866        }
 867
 868        if (a->s == DIFF_SYMBOL_PLUS)
 869                delta = a_width - b_width;
 870        else
 871                delta = b_width - a_width;
 872
 873        if (a_len - a_off != b_len - b_off ||
 874            memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
 875                return 0;
 876
 877        *out = delta;
 878
 879        return 1;
 880}
 881
 882static int cmp_in_block_with_wsd(const struct diff_options *o,
 883                                 const struct moved_entry *cur,
 884                                 const struct moved_entry *match,
 885                                 struct moved_block *pmb,
 886                                 int n)
 887{
 888        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 889        int al = cur->es->len, bl = match->es->len, cl = l->len;
 890        const char *a = cur->es->line,
 891                   *b = match->es->line,
 892                   *c = l->line;
 893        int a_off = cur->es->indent_off,
 894            a_width = cur->es->indent_width,
 895            c_off = l->indent_off,
 896            c_width = l->indent_width;
 897        int delta;
 898
 899        /*
 900         * We need to check if 'cur' is equal to 'match'.  As those
 901         * are from the same (+/-) side, we do not need to adjust for
 902         * indent changes. However these were found using fuzzy
 903         * matching so we do have to check if they are equal. Here we
 904         * just check the lengths. We delay calling memcmp() to check
 905         * the contents until later as if the length comparison for a
 906         * and c fails we can avoid the call all together.
 907         */
 908        if (al != bl)
 909                return 1;
 910
 911        /* If 'l' and 'cur' are both blank then they match. */
 912        if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
 913                return 0;
 914
 915        /*
 916         * The indent changes of the block are known and stored in pmb->wsd;
 917         * however we need to check if the indent changes of the current line
 918         * match those of the current block and that the text of 'l' and 'cur'
 919         * after the indentation match.
 920         */
 921        if (cur->es->s == DIFF_SYMBOL_PLUS)
 922                delta = a_width - c_width;
 923        else
 924                delta = c_width - a_width;
 925
 926        /*
 927         * If the previous lines of this block were all blank then set its
 928         * whitespace delta.
 929         */
 930        if (pmb->wsd == INDENT_BLANKLINE)
 931                pmb->wsd = delta;
 932
 933        return !(delta == pmb->wsd && al - a_off == cl - c_off &&
 934                 !memcmp(a, b, al) && !
 935                 memcmp(a + a_off, c + c_off, al - a_off));
 936}
 937
 938static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 939                           const void *entry,
 940                           const void *entry_or_key,
 941                           const void *keydata)
 942{
 943        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 944        const struct moved_entry *a = entry;
 945        const struct moved_entry *b = entry_or_key;
 946        unsigned flags = diffopt->color_moved_ws_handling
 947                         & XDF_WHITESPACE_FLAGS;
 948
 949        if (diffopt->color_moved_ws_handling &
 950            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 951                /*
 952                 * As there is not specific white space config given,
 953                 * we'd need to check for a new block, so ignore all
 954                 * white space. The setup of the white space
 955                 * configuration for the next block is done else where
 956                 */
 957                flags |= XDF_IGNORE_WHITESPACE;
 958
 959        return !xdiff_compare_lines(a->es->line, a->es->len,
 960                                    b->es->line, b->es->len,
 961                                    flags);
 962}
 963
 964static struct moved_entry *prepare_entry(struct diff_options *o,
 965                                         int line_no)
 966{
 967        struct moved_entry *ret = xmalloc(sizeof(*ret));
 968        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 969        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 970
 971        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 972        ret->es = l;
 973        ret->next_line = NULL;
 974
 975        return ret;
 976}
 977
 978static void add_lines_to_move_detection(struct diff_options *o,
 979                                        struct hashmap *add_lines,
 980                                        struct hashmap *del_lines)
 981{
 982        struct moved_entry *prev_line = NULL;
 983
 984        int n;
 985        for (n = 0; n < o->emitted_symbols->nr; n++) {
 986                struct hashmap *hm;
 987                struct moved_entry *key;
 988
 989                switch (o->emitted_symbols->buf[n].s) {
 990                case DIFF_SYMBOL_PLUS:
 991                        hm = add_lines;
 992                        break;
 993                case DIFF_SYMBOL_MINUS:
 994                        hm = del_lines;
 995                        break;
 996                default:
 997                        prev_line = NULL;
 998                        continue;
 999                }
1000
1001                if (o->color_moved_ws_handling &
1002                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1003                        fill_es_indent_data(&o->emitted_symbols->buf[n]);
1004                key = prepare_entry(o, n);
1005                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
1006                        prev_line->next_line = key;
1007
1008                hashmap_add(hm, key);
1009                prev_line = key;
1010        }
1011}
1012
1013static void pmb_advance_or_null(struct diff_options *o,
1014                                struct moved_entry *match,
1015                                struct hashmap *hm,
1016                                struct moved_block *pmb,
1017                                int pmb_nr)
1018{
1019        int i;
1020        for (i = 0; i < pmb_nr; i++) {
1021                struct moved_entry *prev = pmb[i].match;
1022                struct moved_entry *cur = (prev && prev->next_line) ?
1023                                prev->next_line : NULL;
1024                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
1025                        pmb[i].match = cur;
1026                } else {
1027                        pmb[i].match = NULL;
1028                }
1029        }
1030}
1031
1032static void pmb_advance_or_null_multi_match(struct diff_options *o,
1033                                            struct moved_entry *match,
1034                                            struct hashmap *hm,
1035                                            struct moved_block *pmb,
1036                                            int pmb_nr, int n)
1037{
1038        int i;
1039        char *got_match = xcalloc(1, pmb_nr);
1040
1041        for (; match; match = hashmap_get_next(hm, match)) {
1042                for (i = 0; i < pmb_nr; i++) {
1043                        struct moved_entry *prev = pmb[i].match;
1044                        struct moved_entry *cur = (prev && prev->next_line) ?
1045                                        prev->next_line : NULL;
1046                        if (!cur)
1047                                continue;
1048                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
1049                                got_match[i] |= 1;
1050                }
1051        }
1052
1053        for (i = 0; i < pmb_nr; i++) {
1054                if (got_match[i]) {
1055                        /* Advance to the next line */
1056                        pmb[i].match = pmb[i].match->next_line;
1057                } else {
1058                        moved_block_clear(&pmb[i]);
1059                }
1060        }
1061
1062        free(got_match);
1063}
1064
1065static int shrink_potential_moved_blocks(struct moved_block *pmb,
1066                                         int pmb_nr)
1067{
1068        int lp, rp;
1069
1070        /* Shrink the set of potential block to the remaining running */
1071        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1072                while (lp < pmb_nr && pmb[lp].match)
1073                        lp++;
1074                /* lp points at the first NULL now */
1075
1076                while (rp > -1 && !pmb[rp].match)
1077                        rp--;
1078                /* rp points at the last non-NULL */
1079
1080                if (lp < pmb_nr && rp > -1 && lp < rp) {
1081                        pmb[lp] = pmb[rp];
1082                        memset(&pmb[rp], 0, sizeof(pmb[rp]));
1083                        rp--;
1084                        lp++;
1085                }
1086        }
1087
1088        /* Remember the number of running sets */
1089        return rp + 1;
1090}
1091
1092/*
1093 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1094 *
1095 * Otherwise, if the last block has fewer alphanumeric characters than
1096 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1097 * that block.
1098 *
1099 * The last block consists of the (n - block_length)'th line up to but not
1100 * including the nth line.
1101 *
1102 * Returns 0 if the last block is empty or is unset by this function, non zero
1103 * otherwise.
1104 *
1105 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1106 * Think of a way to unify them.
1107 */
1108static int adjust_last_block(struct diff_options *o, int n, int block_length)
1109{
1110        int i, alnum_count = 0;
1111        if (o->color_moved == COLOR_MOVED_PLAIN)
1112                return block_length;
1113        for (i = 1; i < block_length + 1; i++) {
1114                const char *c = o->emitted_symbols->buf[n - i].line;
1115                for (; *c; c++) {
1116                        if (!isalnum(*c))
1117                                continue;
1118                        alnum_count++;
1119                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1120                                return 1;
1121                }
1122        }
1123        for (i = 1; i < block_length + 1; i++)
1124                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1125        return 0;
1126}
1127
1128/* Find blocks of moved code, delegate actual coloring decision to helper */
1129static void mark_color_as_moved(struct diff_options *o,
1130                                struct hashmap *add_lines,
1131                                struct hashmap *del_lines)
1132{
1133        struct moved_block *pmb = NULL; /* potentially moved blocks */
1134        int pmb_nr = 0, pmb_alloc = 0;
1135        int n, flipped_block = 0, block_length = 0;
1136
1137
1138        for (n = 0; n < o->emitted_symbols->nr; n++) {
1139                struct hashmap *hm = NULL;
1140                struct moved_entry *key;
1141                struct moved_entry *match = NULL;
1142                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1143                enum diff_symbol last_symbol = 0;
1144
1145                switch (l->s) {
1146                case DIFF_SYMBOL_PLUS:
1147                        hm = del_lines;
1148                        key = prepare_entry(o, n);
1149                        match = hashmap_get(hm, key, NULL);
1150                        free(key);
1151                        break;
1152                case DIFF_SYMBOL_MINUS:
1153                        hm = add_lines;
1154                        key = prepare_entry(o, n);
1155                        match = hashmap_get(hm, key, NULL);
1156                        free(key);
1157                        break;
1158                default:
1159                        flipped_block = 0;
1160                }
1161
1162                if (!match) {
1163                        int i;
1164
1165                        adjust_last_block(o, n, block_length);
1166                        for(i = 0; i < pmb_nr; i++)
1167                                moved_block_clear(&pmb[i]);
1168                        pmb_nr = 0;
1169                        block_length = 0;
1170                        flipped_block = 0;
1171                        last_symbol = l->s;
1172                        continue;
1173                }
1174
1175                if (o->color_moved == COLOR_MOVED_PLAIN) {
1176                        last_symbol = l->s;
1177                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1178                        continue;
1179                }
1180
1181                if (o->color_moved_ws_handling &
1182                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1183                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1184                else
1185                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1186
1187                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1188
1189                if (pmb_nr == 0) {
1190                        /*
1191                         * The current line is the start of a new block.
1192                         * Setup the set of potential blocks.
1193                         */
1194                        for (; match; match = hashmap_get_next(hm, match)) {
1195                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1196                                if (o->color_moved_ws_handling &
1197                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1198                                        if (compute_ws_delta(l, match->es,
1199                                                             &pmb[pmb_nr].wsd))
1200                                                pmb[pmb_nr++].match = match;
1201                                } else {
1202                                        pmb[pmb_nr].wsd = 0;
1203                                        pmb[pmb_nr++].match = match;
1204                                }
1205                        }
1206
1207                        if (adjust_last_block(o, n, block_length) &&
1208                            pmb_nr && last_symbol != l->s)
1209                                flipped_block = (flipped_block + 1) % 2;
1210                        else
1211                                flipped_block = 0;
1212
1213                        block_length = 0;
1214                }
1215
1216                if (pmb_nr) {
1217                        block_length++;
1218                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1219                        if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1220                                l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1221                }
1222                last_symbol = l->s;
1223        }
1224        adjust_last_block(o, n, block_length);
1225
1226        for(n = 0; n < pmb_nr; n++)
1227                moved_block_clear(&pmb[n]);
1228        free(pmb);
1229}
1230
1231#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1232  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1233static void dim_moved_lines(struct diff_options *o)
1234{
1235        int n;
1236        for (n = 0; n < o->emitted_symbols->nr; n++) {
1237                struct emitted_diff_symbol *prev = (n != 0) ?
1238                                &o->emitted_symbols->buf[n - 1] : NULL;
1239                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1240                struct emitted_diff_symbol *next =
1241                                (n < o->emitted_symbols->nr - 1) ?
1242                                &o->emitted_symbols->buf[n + 1] : NULL;
1243
1244                /* Not a plus or minus line? */
1245                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1246                        continue;
1247
1248                /* Not a moved line? */
1249                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1250                        continue;
1251
1252                /*
1253                 * If prev or next are not a plus or minus line,
1254                 * pretend they don't exist
1255                 */
1256                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1257                            prev->s != DIFF_SYMBOL_MINUS)
1258                        prev = NULL;
1259                if (next && next->s != DIFF_SYMBOL_PLUS &&
1260                            next->s != DIFF_SYMBOL_MINUS)
1261                        next = NULL;
1262
1263                /* Inside a block? */
1264                if ((prev &&
1265                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1266                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1267                    (next &&
1268                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1269                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1270                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1271                        continue;
1272                }
1273
1274                /* Check if we are at an interesting bound: */
1275                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1276                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1277                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1278                        continue;
1279                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1280                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1281                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1282                        continue;
1283
1284                /*
1285                 * The boundary to prev and next are not interesting,
1286                 * so this line is not interesting as a whole
1287                 */
1288                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1289        }
1290}
1291
1292static void emit_line_ws_markup(struct diff_options *o,
1293                                const char *set_sign, const char *set,
1294                                const char *reset,
1295                                int sign_index, const char *line, int len,
1296                                unsigned ws_rule, int blank_at_eof)
1297{
1298        const char *ws = NULL;
1299        int sign = o->output_indicators[sign_index];
1300
1301        if (o->ws_error_highlight & ws_rule) {
1302                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1303                if (!*ws)
1304                        ws = NULL;
1305        }
1306
1307        if (!ws && !set_sign)
1308                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1309        else if (!ws) {
1310                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1311        } else if (blank_at_eof)
1312                /* Blank line at EOF - paint '+' as well */
1313                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1314        else {
1315                /* Emit just the prefix, then the rest. */
1316                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1317                            sign, "", 0);
1318                ws_check_emit(line, len, ws_rule,
1319                              o->file, set, reset, ws);
1320        }
1321}
1322
1323static void emit_diff_symbol_from_struct(struct diff_options *o,
1324                                         struct emitted_diff_symbol *eds)
1325{
1326        static const char *nneof = " No newline at end of file\n";
1327        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1328        struct strbuf sb = STRBUF_INIT;
1329
1330        enum diff_symbol s = eds->s;
1331        const char *line = eds->line;
1332        int len = eds->len;
1333        unsigned flags = eds->flags;
1334
1335        switch (s) {
1336        case DIFF_SYMBOL_NO_LF_EOF:
1337                context = diff_get_color_opt(o, DIFF_CONTEXT);
1338                reset = diff_get_color_opt(o, DIFF_RESET);
1339                putc('\n', o->file);
1340                emit_line_0(o, context, NULL, 0, reset, '\\',
1341                            nneof, strlen(nneof));
1342                break;
1343        case DIFF_SYMBOL_SUBMODULE_HEADER:
1344        case DIFF_SYMBOL_SUBMODULE_ERROR:
1345        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1346        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1347        case DIFF_SYMBOL_SUMMARY:
1348        case DIFF_SYMBOL_STATS_LINE:
1349        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1350        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1351                emit_line(o, "", "", line, len);
1352                break;
1353        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1354        case DIFF_SYMBOL_CONTEXT_MARKER:
1355                context = diff_get_color_opt(o, DIFF_CONTEXT);
1356                reset = diff_get_color_opt(o, DIFF_RESET);
1357                emit_line(o, context, reset, line, len);
1358                break;
1359        case DIFF_SYMBOL_SEPARATOR:
1360                fprintf(o->file, "%s%c",
1361                        diff_line_prefix(o),
1362                        o->line_termination);
1363                break;
1364        case DIFF_SYMBOL_CONTEXT:
1365                set = diff_get_color_opt(o, DIFF_CONTEXT);
1366                reset = diff_get_color_opt(o, DIFF_RESET);
1367                set_sign = NULL;
1368                if (o->flags.dual_color_diffed_diffs) {
1369                        char c = !len ? 0 : line[0];
1370
1371                        if (c == '+')
1372                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1373                        else if (c == '@')
1374                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1375                        else if (c == '-')
1376                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1377                }
1378                emit_line_ws_markup(o, set_sign, set, reset,
1379                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1380                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1381                break;
1382        case DIFF_SYMBOL_PLUS:
1383                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1384                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1385                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1386                case DIFF_SYMBOL_MOVED_LINE |
1387                     DIFF_SYMBOL_MOVED_LINE_ALT |
1388                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1389                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1390                        break;
1391                case DIFF_SYMBOL_MOVED_LINE |
1392                     DIFF_SYMBOL_MOVED_LINE_ALT:
1393                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1394                        break;
1395                case DIFF_SYMBOL_MOVED_LINE |
1396                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1397                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1398                        break;
1399                case DIFF_SYMBOL_MOVED_LINE:
1400                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1401                        break;
1402                default:
1403                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1404                }
1405                reset = diff_get_color_opt(o, DIFF_RESET);
1406                if (!o->flags.dual_color_diffed_diffs)
1407                        set_sign = NULL;
1408                else {
1409                        char c = !len ? 0 : line[0];
1410
1411                        set_sign = set;
1412                        if (c == '-')
1413                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1414                        else if (c == '@')
1415                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1416                        else if (c == '+')
1417                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1418                        else
1419                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1420                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1421                }
1422                emit_line_ws_markup(o, set_sign, set, reset,
1423                                    OUTPUT_INDICATOR_NEW, line, len,
1424                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1425                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1426                break;
1427        case DIFF_SYMBOL_MINUS:
1428                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1429                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1430                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1431                case DIFF_SYMBOL_MOVED_LINE |
1432                     DIFF_SYMBOL_MOVED_LINE_ALT |
1433                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1434                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1435                        break;
1436                case DIFF_SYMBOL_MOVED_LINE |
1437                     DIFF_SYMBOL_MOVED_LINE_ALT:
1438                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1439                        break;
1440                case DIFF_SYMBOL_MOVED_LINE |
1441                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1442                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1443                        break;
1444                case DIFF_SYMBOL_MOVED_LINE:
1445                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1446                        break;
1447                default:
1448                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1449                }
1450                reset = diff_get_color_opt(o, DIFF_RESET);
1451                if (!o->flags.dual_color_diffed_diffs)
1452                        set_sign = NULL;
1453                else {
1454                        char c = !len ? 0 : line[0];
1455
1456                        set_sign = set;
1457                        if (c == '+')
1458                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1459                        else if (c == '@')
1460                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1461                        else if (c == '-')
1462                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1463                        else
1464                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1465                }
1466                emit_line_ws_markup(o, set_sign, set, reset,
1467                                    OUTPUT_INDICATOR_OLD, line, len,
1468                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1469                break;
1470        case DIFF_SYMBOL_WORDS_PORCELAIN:
1471                context = diff_get_color_opt(o, DIFF_CONTEXT);
1472                reset = diff_get_color_opt(o, DIFF_RESET);
1473                emit_line(o, context, reset, line, len);
1474                fputs("~\n", o->file);
1475                break;
1476        case DIFF_SYMBOL_WORDS:
1477                context = diff_get_color_opt(o, DIFF_CONTEXT);
1478                reset = diff_get_color_opt(o, DIFF_RESET);
1479                /*
1480                 * Skip the prefix character, if any.  With
1481                 * diff_suppress_blank_empty, there may be
1482                 * none.
1483                 */
1484                if (line[0] != '\n') {
1485                        line++;
1486                        len--;
1487                }
1488                emit_line(o, context, reset, line, len);
1489                break;
1490        case DIFF_SYMBOL_FILEPAIR_PLUS:
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_FILEPAIR_MINUS:
1498                meta = diff_get_color_opt(o, DIFF_METAINFO);
1499                reset = diff_get_color_opt(o, DIFF_RESET);
1500                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1501                        line, reset,
1502                        strchr(line, ' ') ? "\t" : "");
1503                break;
1504        case DIFF_SYMBOL_BINARY_FILES:
1505        case DIFF_SYMBOL_HEADER:
1506                fprintf(o->file, "%s", line);
1507                break;
1508        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1509                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1510                break;
1511        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1512                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1513                break;
1514        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1515                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1516                break;
1517        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1518                fputs(diff_line_prefix(o), o->file);
1519                fputc('\n', o->file);
1520                break;
1521        case DIFF_SYMBOL_REWRITE_DIFF:
1522                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1523                reset = diff_get_color_opt(o, DIFF_RESET);
1524                emit_line(o, fraginfo, reset, line, len);
1525                break;
1526        case DIFF_SYMBOL_SUBMODULE_ADD:
1527                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1528                reset = diff_get_color_opt(o, DIFF_RESET);
1529                emit_line(o, set, reset, line, len);
1530                break;
1531        case DIFF_SYMBOL_SUBMODULE_DEL:
1532                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1533                reset = diff_get_color_opt(o, DIFF_RESET);
1534                emit_line(o, set, reset, line, len);
1535                break;
1536        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1537                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1538                        diff_line_prefix(o), line);
1539                break;
1540        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1541                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1542                        diff_line_prefix(o), line);
1543                break;
1544        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1545                emit_line(o, "", "", " 0 files changed\n",
1546                          strlen(" 0 files changed\n"));
1547                break;
1548        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1549                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1550                break;
1551        case DIFF_SYMBOL_WORD_DIFF:
1552                fprintf(o->file, "%.*s", len, line);
1553                break;
1554        case DIFF_SYMBOL_STAT_SEP:
1555                fputs(o->stat_sep, o->file);
1556                break;
1557        default:
1558                BUG("unknown diff symbol");
1559        }
1560        strbuf_release(&sb);
1561}
1562
1563static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1564                             const char *line, int len, unsigned flags)
1565{
1566        struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
1567
1568        if (o->emitted_symbols)
1569                append_emitted_diff_symbol(o, &e);
1570        else
1571                emit_diff_symbol_from_struct(o, &e);
1572}
1573
1574void diff_emit_submodule_del(struct diff_options *o, const char *line)
1575{
1576        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1577}
1578
1579void diff_emit_submodule_add(struct diff_options *o, const char *line)
1580{
1581        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1582}
1583
1584void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1585{
1586        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1587                         path, strlen(path), 0);
1588}
1589
1590void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1591{
1592        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1593                         path, strlen(path), 0);
1594}
1595
1596void diff_emit_submodule_header(struct diff_options *o, const char *header)
1597{
1598        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1599                         header, strlen(header), 0);
1600}
1601
1602void diff_emit_submodule_error(struct diff_options *o, const char *err)
1603{
1604        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1605}
1606
1607void diff_emit_submodule_pipethrough(struct diff_options *o,
1608                                     const char *line, int len)
1609{
1610        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1611}
1612
1613static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1614{
1615        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1616              ecbdata->blank_at_eof_in_preimage &&
1617              ecbdata->blank_at_eof_in_postimage &&
1618              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1619              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1620                return 0;
1621        return ws_blank_line(line, len, ecbdata->ws_rule);
1622}
1623
1624static void emit_add_line(const char *reset,
1625                          struct emit_callback *ecbdata,
1626                          const char *line, int len)
1627{
1628        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1629        if (new_blank_line_at_eof(ecbdata, line, len))
1630                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1631
1632        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1633}
1634
1635static void emit_del_line(const char *reset,
1636                          struct emit_callback *ecbdata,
1637                          const char *line, int len)
1638{
1639        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1640        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1641}
1642
1643static void emit_context_line(const char *reset,
1644                              struct emit_callback *ecbdata,
1645                              const char *line, int len)
1646{
1647        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1648        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1649}
1650
1651static void emit_hunk_header(struct emit_callback *ecbdata,
1652                             const char *line, int len)
1653{
1654        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1655        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1656        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1657        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1658        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1659        static const char atat[2] = { '@', '@' };
1660        const char *cp, *ep;
1661        struct strbuf msgbuf = STRBUF_INIT;
1662        int org_len = len;
1663        int i = 1;
1664
1665        /*
1666         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1667         * it always is at least 10 bytes long.
1668         */
1669        if (len < 10 ||
1670            memcmp(line, atat, 2) ||
1671            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1672                emit_diff_symbol(ecbdata->opt,
1673                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1674                return;
1675        }
1676        ep += 2; /* skip over @@ */
1677
1678        /* The hunk header in fraginfo color */
1679        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1680                strbuf_addstr(&msgbuf, reverse);
1681        strbuf_addstr(&msgbuf, frag);
1682        strbuf_add(&msgbuf, line, ep - line);
1683        strbuf_addstr(&msgbuf, reset);
1684
1685        /*
1686         * trailing "\r\n"
1687         */
1688        for ( ; i < 3; i++)
1689                if (line[len - i] == '\r' || line[len - i] == '\n')
1690                        len--;
1691
1692        /* blank before the func header */
1693        for (cp = ep; ep - line < len; ep++)
1694                if (*ep != ' ' && *ep != '\t')
1695                        break;
1696        if (ep != cp) {
1697                strbuf_addstr(&msgbuf, context);
1698                strbuf_add(&msgbuf, cp, ep - cp);
1699                strbuf_addstr(&msgbuf, reset);
1700        }
1701
1702        if (ep < line + len) {
1703                strbuf_addstr(&msgbuf, func);
1704                strbuf_add(&msgbuf, ep, line + len - ep);
1705                strbuf_addstr(&msgbuf, reset);
1706        }
1707
1708        strbuf_add(&msgbuf, line + len, org_len - len);
1709        strbuf_complete_line(&msgbuf);
1710        emit_diff_symbol(ecbdata->opt,
1711                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1712        strbuf_release(&msgbuf);
1713}
1714
1715static struct diff_tempfile *claim_diff_tempfile(void)
1716{
1717        int i;
1718        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1719                if (!diff_temp[i].name)
1720                        return diff_temp + i;
1721        BUG("diff is failing to clean up its tempfiles");
1722}
1723
1724static void remove_tempfile(void)
1725{
1726        int i;
1727        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1728                if (is_tempfile_active(diff_temp[i].tempfile))
1729                        delete_tempfile(&diff_temp[i].tempfile);
1730                diff_temp[i].name = NULL;
1731        }
1732}
1733
1734static void add_line_count(struct strbuf *out, int count)
1735{
1736        switch (count) {
1737        case 0:
1738                strbuf_addstr(out, "0,0");
1739                break;
1740        case 1:
1741                strbuf_addstr(out, "1");
1742                break;
1743        default:
1744                strbuf_addf(out, "1,%d", count);
1745                break;
1746        }
1747}
1748
1749static void emit_rewrite_lines(struct emit_callback *ecb,
1750                               int prefix, const char *data, int size)
1751{
1752        const char *endp = NULL;
1753        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1754
1755        while (0 < size) {
1756                int len;
1757
1758                endp = memchr(data, '\n', size);
1759                len = endp ? (endp - data + 1) : size;
1760                if (prefix != '+') {
1761                        ecb->lno_in_preimage++;
1762                        emit_del_line(reset, ecb, data, len);
1763                } else {
1764                        ecb->lno_in_postimage++;
1765                        emit_add_line(reset, ecb, data, len);
1766                }
1767                size -= len;
1768                data += len;
1769        }
1770        if (!endp)
1771                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1772}
1773
1774static void emit_rewrite_diff(const char *name_a,
1775                              const char *name_b,
1776                              struct diff_filespec *one,
1777                              struct diff_filespec *two,
1778                              struct userdiff_driver *textconv_one,
1779                              struct userdiff_driver *textconv_two,
1780                              struct diff_options *o)
1781{
1782        int lc_a, lc_b;
1783        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1784        const char *a_prefix, *b_prefix;
1785        char *data_one, *data_two;
1786        size_t size_one, size_two;
1787        struct emit_callback ecbdata;
1788        struct strbuf out = STRBUF_INIT;
1789
1790        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1791                a_prefix = o->b_prefix;
1792                b_prefix = o->a_prefix;
1793        } else {
1794                a_prefix = o->a_prefix;
1795                b_prefix = o->b_prefix;
1796        }
1797
1798        name_a += (*name_a == '/');
1799        name_b += (*name_b == '/');
1800
1801        strbuf_reset(&a_name);
1802        strbuf_reset(&b_name);
1803        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1804        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1805
1806        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1807        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1808
1809        memset(&ecbdata, 0, sizeof(ecbdata));
1810        ecbdata.color_diff = want_color(o->use_color);
1811        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1812        ecbdata.opt = o;
1813        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1814                mmfile_t mf1, mf2;
1815                mf1.ptr = (char *)data_one;
1816                mf2.ptr = (char *)data_two;
1817                mf1.size = size_one;
1818                mf2.size = size_two;
1819                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1820        }
1821        ecbdata.lno_in_preimage = 1;
1822        ecbdata.lno_in_postimage = 1;
1823
1824        lc_a = count_lines(data_one, size_one);
1825        lc_b = count_lines(data_two, size_two);
1826
1827        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1828                         a_name.buf, a_name.len, 0);
1829        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1830                         b_name.buf, b_name.len, 0);
1831
1832        strbuf_addstr(&out, "@@ -");
1833        if (!o->irreversible_delete)
1834                add_line_count(&out, lc_a);
1835        else
1836                strbuf_addstr(&out, "?,?");
1837        strbuf_addstr(&out, " +");
1838        add_line_count(&out, lc_b);
1839        strbuf_addstr(&out, " @@\n");
1840        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1841        strbuf_release(&out);
1842
1843        if (lc_a && !o->irreversible_delete)
1844                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1845        if (lc_b)
1846                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1847        if (textconv_one)
1848                free((char *)data_one);
1849        if (textconv_two)
1850                free((char *)data_two);
1851}
1852
1853struct diff_words_buffer {
1854        mmfile_t text;
1855        unsigned long alloc;
1856        struct diff_words_orig {
1857                const char *begin, *end;
1858        } *orig;
1859        int orig_nr, orig_alloc;
1860};
1861
1862static void diff_words_append(char *line, unsigned long len,
1863                struct diff_words_buffer *buffer)
1864{
1865        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1866        line++;
1867        len--;
1868        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1869        buffer->text.size += len;
1870        buffer->text.ptr[buffer->text.size] = '\0';
1871}
1872
1873struct diff_words_style_elem {
1874        const char *prefix;
1875        const char *suffix;
1876        const char *color; /* NULL; filled in by the setup code if
1877                            * color is enabled */
1878};
1879
1880struct diff_words_style {
1881        enum diff_words_type type;
1882        struct diff_words_style_elem new_word, old_word, ctx;
1883        const char *newline;
1884};
1885
1886static struct diff_words_style diff_words_styles[] = {
1887        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1888        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1889        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1890};
1891
1892struct diff_words_data {
1893        struct diff_words_buffer minus, plus;
1894        const char *current_plus;
1895        int last_minus;
1896        struct diff_options *opt;
1897        regex_t *word_regex;
1898        enum diff_words_type type;
1899        struct diff_words_style *style;
1900};
1901
1902static int fn_out_diff_words_write_helper(struct diff_options *o,
1903                                          struct diff_words_style_elem *st_el,
1904                                          const char *newline,
1905                                          size_t count, const char *buf)
1906{
1907        int print = 0;
1908        struct strbuf sb = STRBUF_INIT;
1909
1910        while (count) {
1911                char *p = memchr(buf, '\n', count);
1912                if (print)
1913                        strbuf_addstr(&sb, diff_line_prefix(o));
1914
1915                if (p != buf) {
1916                        const char *reset = st_el->color && *st_el->color ?
1917                                            GIT_COLOR_RESET : NULL;
1918                        if (st_el->color && *st_el->color)
1919                                strbuf_addstr(&sb, st_el->color);
1920                        strbuf_addstr(&sb, st_el->prefix);
1921                        strbuf_add(&sb, buf, p ? p - buf : count);
1922                        strbuf_addstr(&sb, st_el->suffix);
1923                        if (reset)
1924                                strbuf_addstr(&sb, reset);
1925                }
1926                if (!p)
1927                        goto out;
1928
1929                strbuf_addstr(&sb, newline);
1930                count -= p + 1 - buf;
1931                buf = p + 1;
1932                print = 1;
1933                if (count) {
1934                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1935                                         sb.buf, sb.len, 0);
1936                        strbuf_reset(&sb);
1937                }
1938        }
1939
1940out:
1941        if (sb.len)
1942                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1943                                 sb.buf, sb.len, 0);
1944        strbuf_release(&sb);
1945        return 0;
1946}
1947
1948/*
1949 * '--color-words' algorithm can be described as:
1950 *
1951 *   1. collect the minus/plus lines of a diff hunk, divided into
1952 *      minus-lines and plus-lines;
1953 *
1954 *   2. break both minus-lines and plus-lines into words and
1955 *      place them into two mmfile_t with one word for each line;
1956 *
1957 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1958 *
1959 * And for the common parts of the both file, we output the plus side text.
1960 * diff_words->current_plus is used to trace the current position of the plus file
1961 * which printed. diff_words->last_minus is used to trace the last minus word
1962 * printed.
1963 *
1964 * For '--graph' to work with '--color-words', we need to output the graph prefix
1965 * on each line of color words output. Generally, there are two conditions on
1966 * which we should output the prefix.
1967 *
1968 *   1. diff_words->last_minus == 0 &&
1969 *      diff_words->current_plus == diff_words->plus.text.ptr
1970 *
1971 *      that is: the plus text must start as a new line, and if there is no minus
1972 *      word printed, a graph prefix must be printed.
1973 *
1974 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1975 *      *(diff_words->current_plus - 1) == '\n'
1976 *
1977 *      that is: a graph prefix must be printed following a '\n'
1978 */
1979static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1980{
1981        if ((diff_words->last_minus == 0 &&
1982                diff_words->current_plus == diff_words->plus.text.ptr) ||
1983                (diff_words->current_plus > diff_words->plus.text.ptr &&
1984                *(diff_words->current_plus - 1) == '\n')) {
1985                return 1;
1986        } else {
1987                return 0;
1988        }
1989}
1990
1991static void fn_out_diff_words_aux(void *priv,
1992                                  long minus_first, long minus_len,
1993                                  long plus_first, long plus_len,
1994                                  const char *func, long funclen)
1995{
1996        struct diff_words_data *diff_words = priv;
1997        struct diff_words_style *style = diff_words->style;
1998        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1999        struct diff_options *opt = diff_words->opt;
2000        const char *line_prefix;
2001
2002        assert(opt);
2003        line_prefix = diff_line_prefix(opt);
2004
2005        /* POSIX requires that first be decremented by one if len == 0... */
2006        if (minus_len) {
2007                minus_begin = diff_words->minus.orig[minus_first].begin;
2008                minus_end =
2009                        diff_words->minus.orig[minus_first + minus_len - 1].end;
2010        } else
2011                minus_begin = minus_end =
2012                        diff_words->minus.orig[minus_first].end;
2013
2014        if (plus_len) {
2015                plus_begin = diff_words->plus.orig[plus_first].begin;
2016                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
2017        } else
2018                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
2019
2020        if (color_words_output_graph_prefix(diff_words)) {
2021                fputs(line_prefix, diff_words->opt->file);
2022        }
2023        if (diff_words->current_plus != plus_begin) {
2024                fn_out_diff_words_write_helper(diff_words->opt,
2025                                &style->ctx, style->newline,
2026                                plus_begin - diff_words->current_plus,
2027                                diff_words->current_plus);
2028        }
2029        if (minus_begin != minus_end) {
2030                fn_out_diff_words_write_helper(diff_words->opt,
2031                                &style->old_word, style->newline,
2032                                minus_end - minus_begin, minus_begin);
2033        }
2034        if (plus_begin != plus_end) {
2035                fn_out_diff_words_write_helper(diff_words->opt,
2036                                &style->new_word, style->newline,
2037                                plus_end - plus_begin, plus_begin);
2038        }
2039
2040        diff_words->current_plus = plus_end;
2041        diff_words->last_minus = minus_first;
2042}
2043
2044/* This function starts looking at *begin, and returns 0 iff a word was found. */
2045static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
2046                int *begin, int *end)
2047{
2048        if (word_regex && *begin < buffer->size) {
2049                regmatch_t match[1];
2050                if (!regexec_buf(word_regex, buffer->ptr + *begin,
2051                                 buffer->size - *begin, 1, match, 0)) {
2052                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
2053                                        '\n', match[0].rm_eo - match[0].rm_so);
2054                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
2055                        *begin += match[0].rm_so;
2056                        return *begin >= *end;
2057                }
2058                return -1;
2059        }
2060
2061        /* find the next word */
2062        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
2063                (*begin)++;
2064        if (*begin >= buffer->size)
2065                return -1;
2066
2067        /* find the end of the word */
2068        *end = *begin + 1;
2069        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
2070                (*end)++;
2071
2072        return 0;
2073}
2074
2075/*
2076 * This function splits the words in buffer->text, stores the list with
2077 * newline separator into out, and saves the offsets of the original words
2078 * in buffer->orig.
2079 */
2080static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2081                regex_t *word_regex)
2082{
2083        int i, j;
2084        long alloc = 0;
2085
2086        out->size = 0;
2087        out->ptr = NULL;
2088
2089        /* fake an empty "0th" word */
2090        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2091        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2092        buffer->orig_nr = 1;
2093
2094        for (i = 0; i < buffer->text.size; i++) {
2095                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2096                        return;
2097
2098                /* store original boundaries */
2099                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2100                                buffer->orig_alloc);
2101                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2102                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2103                buffer->orig_nr++;
2104
2105                /* store one word */
2106                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2107                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2108                out->ptr[out->size + j - i] = '\n';
2109                out->size += j - i + 1;
2110
2111                i = j - 1;
2112        }
2113}
2114
2115/* this executes the word diff on the accumulated buffers */
2116static void diff_words_show(struct diff_words_data *diff_words)
2117{
2118        xpparam_t xpp;
2119        xdemitconf_t xecfg;
2120        mmfile_t minus, plus;
2121        struct diff_words_style *style = diff_words->style;
2122
2123        struct diff_options *opt = diff_words->opt;
2124        const char *line_prefix;
2125
2126        assert(opt);
2127        line_prefix = diff_line_prefix(opt);
2128
2129        /* special case: only removal */
2130        if (!diff_words->plus.text.size) {
2131                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2132                                 line_prefix, strlen(line_prefix), 0);
2133                fn_out_diff_words_write_helper(diff_words->opt,
2134                        &style->old_word, style->newline,
2135                        diff_words->minus.text.size,
2136                        diff_words->minus.text.ptr);
2137                diff_words->minus.text.size = 0;
2138                return;
2139        }
2140
2141        diff_words->current_plus = diff_words->plus.text.ptr;
2142        diff_words->last_minus = 0;
2143
2144        memset(&xpp, 0, sizeof(xpp));
2145        memset(&xecfg, 0, sizeof(xecfg));
2146        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2147        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2148        xpp.flags = 0;
2149        /* as only the hunk header will be parsed, we need a 0-context */
2150        xecfg.ctxlen = 0;
2151        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2152                          diff_words, &xpp, &xecfg))
2153                die("unable to generate word diff");
2154        free(minus.ptr);
2155        free(plus.ptr);
2156        if (diff_words->current_plus != diff_words->plus.text.ptr +
2157                        diff_words->plus.text.size) {
2158                if (color_words_output_graph_prefix(diff_words))
2159                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2160                                         line_prefix, strlen(line_prefix), 0);
2161                fn_out_diff_words_write_helper(diff_words->opt,
2162                        &style->ctx, style->newline,
2163                        diff_words->plus.text.ptr + diff_words->plus.text.size
2164                        - diff_words->current_plus, diff_words->current_plus);
2165        }
2166        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2167}
2168
2169/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2170static void diff_words_flush(struct emit_callback *ecbdata)
2171{
2172        struct diff_options *wo = ecbdata->diff_words->opt;
2173
2174        if (ecbdata->diff_words->minus.text.size ||
2175            ecbdata->diff_words->plus.text.size)
2176                diff_words_show(ecbdata->diff_words);
2177
2178        if (wo->emitted_symbols) {
2179                struct diff_options *o = ecbdata->opt;
2180                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2181                int i;
2182
2183                /*
2184                 * NEEDSWORK:
2185                 * Instead of appending each, concat all words to a line?
2186                 */
2187                for (i = 0; i < wol->nr; i++)
2188                        append_emitted_diff_symbol(o, &wol->buf[i]);
2189
2190                for (i = 0; i < wol->nr; i++)
2191                        free((void *)wol->buf[i].line);
2192
2193                wol->nr = 0;
2194        }
2195}
2196
2197static void diff_filespec_load_driver(struct diff_filespec *one,
2198                                      struct index_state *istate)
2199{
2200        /* Use already-loaded driver */
2201        if (one->driver)
2202                return;
2203
2204        if (S_ISREG(one->mode))
2205                one->driver = userdiff_find_by_path(istate, one->path);
2206
2207        /* Fallback to default settings */
2208        if (!one->driver)
2209                one->driver = userdiff_find_by_name("default");
2210}
2211
2212static const char *userdiff_word_regex(struct diff_filespec *one,
2213                                       struct index_state *istate)
2214{
2215        diff_filespec_load_driver(one, istate);
2216        return one->driver->word_regex;
2217}
2218
2219static void init_diff_words_data(struct emit_callback *ecbdata,
2220                                 struct diff_options *orig_opts,
2221                                 struct diff_filespec *one,
2222                                 struct diff_filespec *two)
2223{
2224        int i;
2225        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2226        memcpy(o, orig_opts, sizeof(struct diff_options));
2227
2228        ecbdata->diff_words =
2229                xcalloc(1, sizeof(struct diff_words_data));
2230        ecbdata->diff_words->type = o->word_diff;
2231        ecbdata->diff_words->opt = o;
2232
2233        if (orig_opts->emitted_symbols)
2234                o->emitted_symbols =
2235                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2236
2237        if (!o->word_regex)
2238                o->word_regex = userdiff_word_regex(one, o->repo->index);
2239        if (!o->word_regex)
2240                o->word_regex = userdiff_word_regex(two, o->repo->index);
2241        if (!o->word_regex)
2242                o->word_regex = diff_word_regex_cfg;
2243        if (o->word_regex) {
2244                ecbdata->diff_words->word_regex = (regex_t *)
2245                        xmalloc(sizeof(regex_t));
2246                if (regcomp(ecbdata->diff_words->word_regex,
2247                            o->word_regex,
2248                            REG_EXTENDED | REG_NEWLINE))
2249                        die("invalid regular expression: %s",
2250                            o->word_regex);
2251        }
2252        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2253                if (o->word_diff == diff_words_styles[i].type) {
2254                        ecbdata->diff_words->style =
2255                                &diff_words_styles[i];
2256                        break;
2257                }
2258        }
2259        if (want_color(o->use_color)) {
2260                struct diff_words_style *st = ecbdata->diff_words->style;
2261                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2262                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2263                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2264        }
2265}
2266
2267static void free_diff_words_data(struct emit_callback *ecbdata)
2268{
2269        if (ecbdata->diff_words) {
2270                diff_words_flush(ecbdata);
2271                free (ecbdata->diff_words->opt->emitted_symbols);
2272                free (ecbdata->diff_words->opt);
2273                free (ecbdata->diff_words->minus.text.ptr);
2274                free (ecbdata->diff_words->minus.orig);
2275                free (ecbdata->diff_words->plus.text.ptr);
2276                free (ecbdata->diff_words->plus.orig);
2277                if (ecbdata->diff_words->word_regex) {
2278                        regfree(ecbdata->diff_words->word_regex);
2279                        free(ecbdata->diff_words->word_regex);
2280                }
2281                FREE_AND_NULL(ecbdata->diff_words);
2282        }
2283}
2284
2285const char *diff_get_color(int diff_use_color, enum color_diff ix)
2286{
2287        if (want_color(diff_use_color))
2288                return diff_colors[ix];
2289        return "";
2290}
2291
2292const char *diff_line_prefix(struct diff_options *opt)
2293{
2294        struct strbuf *msgbuf;
2295        if (!opt->output_prefix)
2296                return "";
2297
2298        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2299        return msgbuf->buf;
2300}
2301
2302static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2303{
2304        const char *cp;
2305        unsigned long allot;
2306        size_t l = len;
2307
2308        cp = line;
2309        allot = l;
2310        while (0 < l) {
2311                (void) utf8_width(&cp, &l);
2312                if (!cp)
2313                        break; /* truncated in the middle? */
2314        }
2315        return allot - l;
2316}
2317
2318static void find_lno(const char *line, struct emit_callback *ecbdata)
2319{
2320        const char *p;
2321        ecbdata->lno_in_preimage = 0;
2322        ecbdata->lno_in_postimage = 0;
2323        p = strchr(line, '-');
2324        if (!p)
2325                return; /* cannot happen */
2326        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2327        p = strchr(p, '+');
2328        if (!p)
2329                return; /* cannot happen */
2330        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2331}
2332
2333static void fn_out_consume(void *priv, char *line, unsigned long len)
2334{
2335        struct emit_callback *ecbdata = priv;
2336        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2337        struct diff_options *o = ecbdata->opt;
2338
2339        o->found_changes = 1;
2340
2341        if (ecbdata->header) {
2342                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2343                                 ecbdata->header->buf, ecbdata->header->len, 0);
2344                strbuf_reset(ecbdata->header);
2345                ecbdata->header = NULL;
2346        }
2347
2348        if (ecbdata->label_path[0]) {
2349                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2350                                 ecbdata->label_path[0],
2351                                 strlen(ecbdata->label_path[0]), 0);
2352                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2353                                 ecbdata->label_path[1],
2354                                 strlen(ecbdata->label_path[1]), 0);
2355                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2356        }
2357
2358        if (diff_suppress_blank_empty
2359            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2360                line[0] = '\n';
2361                len = 1;
2362        }
2363
2364        if (line[0] == '@') {
2365                if (ecbdata->diff_words)
2366                        diff_words_flush(ecbdata);
2367                len = sane_truncate_line(ecbdata, line, len);
2368                find_lno(line, ecbdata);
2369                emit_hunk_header(ecbdata, line, len);
2370                return;
2371        }
2372
2373        if (ecbdata->diff_words) {
2374                enum diff_symbol s =
2375                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2376                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2377                if (line[0] == '-') {
2378                        diff_words_append(line, len,
2379                                          &ecbdata->diff_words->minus);
2380                        return;
2381                } else if (line[0] == '+') {
2382                        diff_words_append(line, len,
2383                                          &ecbdata->diff_words->plus);
2384                        return;
2385                } else if (starts_with(line, "\\ ")) {
2386                        /*
2387                         * Eat the "no newline at eof" marker as if we
2388                         * saw a "+" or "-" line with nothing on it,
2389                         * and return without diff_words_flush() to
2390                         * defer processing. If this is the end of
2391                         * preimage, more "+" lines may come after it.
2392                         */
2393                        return;
2394                }
2395                diff_words_flush(ecbdata);
2396                emit_diff_symbol(o, s, line, len, 0);
2397                return;
2398        }
2399
2400        switch (line[0]) {
2401        case '+':
2402                ecbdata->lno_in_postimage++;
2403                emit_add_line(reset, ecbdata, line + 1, len - 1);
2404                break;
2405        case '-':
2406                ecbdata->lno_in_preimage++;
2407                emit_del_line(reset, ecbdata, line + 1, len - 1);
2408                break;
2409        case ' ':
2410                ecbdata->lno_in_postimage++;
2411                ecbdata->lno_in_preimage++;
2412                emit_context_line(reset, ecbdata, line + 1, len - 1);
2413                break;
2414        default:
2415                /* incomplete line at the end */
2416                ecbdata->lno_in_preimage++;
2417                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2418                                 line, len, 0);
2419                break;
2420        }
2421}
2422
2423static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2424{
2425        const char *old_name = a;
2426        const char *new_name = b;
2427        int pfx_length, sfx_length;
2428        int pfx_adjust_for_slash;
2429        int len_a = strlen(a);
2430        int len_b = strlen(b);
2431        int a_midlen, b_midlen;
2432        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2433        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2434
2435        if (qlen_a || qlen_b) {
2436                quote_c_style(a, name, NULL, 0);
2437                strbuf_addstr(name, " => ");
2438                quote_c_style(b, name, NULL, 0);
2439                return;
2440        }
2441
2442        /* Find common prefix */
2443        pfx_length = 0;
2444        while (*old_name && *new_name && *old_name == *new_name) {
2445                if (*old_name == '/')
2446                        pfx_length = old_name - a + 1;
2447                old_name++;
2448                new_name++;
2449        }
2450
2451        /* Find common suffix */
2452        old_name = a + len_a;
2453        new_name = b + len_b;
2454        sfx_length = 0;
2455        /*
2456         * If there is a common prefix, it must end in a slash.  In
2457         * that case we let this loop run 1 into the prefix to see the
2458         * same slash.
2459         *
2460         * If there is no common prefix, we cannot do this as it would
2461         * underrun the input strings.
2462         */
2463        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2464        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2465               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2466               *old_name == *new_name) {
2467                if (*old_name == '/')
2468                        sfx_length = len_a - (old_name - a);
2469                old_name--;
2470                new_name--;
2471        }
2472
2473        /*
2474         * pfx{mid-a => mid-b}sfx
2475         * {pfx-a => pfx-b}sfx
2476         * pfx{sfx-a => sfx-b}
2477         * name-a => name-b
2478         */
2479        a_midlen = len_a - pfx_length - sfx_length;
2480        b_midlen = len_b - pfx_length - sfx_length;
2481        if (a_midlen < 0)
2482                a_midlen = 0;
2483        if (b_midlen < 0)
2484                b_midlen = 0;
2485
2486        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2487        if (pfx_length + sfx_length) {
2488                strbuf_add(name, a, pfx_length);
2489                strbuf_addch(name, '{');
2490        }
2491        strbuf_add(name, a + pfx_length, a_midlen);
2492        strbuf_addstr(name, " => ");
2493        strbuf_add(name, b + pfx_length, b_midlen);
2494        if (pfx_length + sfx_length) {
2495                strbuf_addch(name, '}');
2496                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2497        }
2498}
2499
2500struct diffstat_t {
2501        int nr;
2502        int alloc;
2503        struct diffstat_file {
2504                char *from_name;
2505                char *name;
2506                char *print_name;
2507                const char *comments;
2508                unsigned is_unmerged:1;
2509                unsigned is_binary:1;
2510                unsigned is_renamed:1;
2511                unsigned is_interesting:1;
2512                uintmax_t added, deleted;
2513        } **files;
2514};
2515
2516static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2517                                          const char *name_a,
2518                                          const char *name_b)
2519{
2520        struct diffstat_file *x;
2521        x = xcalloc(1, sizeof(*x));
2522        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2523        diffstat->files[diffstat->nr++] = x;
2524        if (name_b) {
2525                x->from_name = xstrdup(name_a);
2526                x->name = xstrdup(name_b);
2527                x->is_renamed = 1;
2528        }
2529        else {
2530                x->from_name = NULL;
2531                x->name = xstrdup(name_a);
2532        }
2533        return x;
2534}
2535
2536static void diffstat_consume(void *priv, char *line, unsigned long len)
2537{
2538        struct diffstat_t *diffstat = priv;
2539        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2540
2541        if (line[0] == '+')
2542                x->added++;
2543        else if (line[0] == '-')
2544                x->deleted++;
2545}
2546
2547const char mime_boundary_leader[] = "------------";
2548
2549static int scale_linear(int it, int width, int max_change)
2550{
2551        if (!it)
2552                return 0;
2553        /*
2554         * make sure that at least one '-' or '+' is printed if
2555         * there is any change to this path. The easiest way is to
2556         * scale linearly as if the alloted width is one column shorter
2557         * than it is, and then add 1 to the result.
2558         */
2559        return 1 + (it * (width - 1) / max_change);
2560}
2561
2562static void show_graph(struct strbuf *out, char ch, int cnt,
2563                       const char *set, const char *reset)
2564{
2565        if (cnt <= 0)
2566                return;
2567        strbuf_addstr(out, set);
2568        strbuf_addchars(out, ch, cnt);
2569        strbuf_addstr(out, reset);
2570}
2571
2572static void fill_print_name(struct diffstat_file *file)
2573{
2574        struct strbuf pname = STRBUF_INIT;
2575
2576        if (file->print_name)
2577                return;
2578
2579        if (file->is_renamed)
2580                pprint_rename(&pname, file->from_name, file->name);
2581        else
2582                quote_c_style(file->name, &pname, NULL, 0);
2583
2584        if (file->comments)
2585                strbuf_addf(&pname, " (%s)", file->comments);
2586
2587        file->print_name = strbuf_detach(&pname, NULL);
2588}
2589
2590static void print_stat_summary_inserts_deletes(struct diff_options *options,
2591                int files, int insertions, int deletions)
2592{
2593        struct strbuf sb = STRBUF_INIT;
2594
2595        if (!files) {
2596                assert(insertions == 0 && deletions == 0);
2597                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2598                                 NULL, 0, 0);
2599                return;
2600        }
2601
2602        strbuf_addf(&sb,
2603                    (files == 1) ? " %d file changed" : " %d files changed",
2604                    files);
2605
2606        /*
2607         * For binary diff, the caller may want to print "x files
2608         * changed" with insertions == 0 && deletions == 0.
2609         *
2610         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2611         * is probably less confusing (i.e skip over "2 files changed
2612         * but nothing about added/removed lines? Is this a bug in Git?").
2613         */
2614        if (insertions || deletions == 0) {
2615                strbuf_addf(&sb,
2616                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2617                            insertions);
2618        }
2619
2620        if (deletions || insertions == 0) {
2621                strbuf_addf(&sb,
2622                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2623                            deletions);
2624        }
2625        strbuf_addch(&sb, '\n');
2626        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2627                         sb.buf, sb.len, 0);
2628        strbuf_release(&sb);
2629}
2630
2631void print_stat_summary(FILE *fp, int files,
2632                        int insertions, int deletions)
2633{
2634        struct diff_options o;
2635        memset(&o, 0, sizeof(o));
2636        o.file = fp;
2637
2638        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2639}
2640
2641static void show_stats(struct diffstat_t *data, struct diff_options *options)
2642{
2643        int i, len, add, del, adds = 0, dels = 0;
2644        uintmax_t max_change = 0, max_len = 0;
2645        int total_files = data->nr, count;
2646        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2647        const char *reset, *add_c, *del_c;
2648        int extra_shown = 0;
2649        const char *line_prefix = diff_line_prefix(options);
2650        struct strbuf out = STRBUF_INIT;
2651
2652        if (data->nr == 0)
2653                return;
2654
2655        count = options->stat_count ? options->stat_count : data->nr;
2656
2657        reset = diff_get_color_opt(options, DIFF_RESET);
2658        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2659        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2660
2661        /*
2662         * Find the longest filename and max number of changes
2663         */
2664        for (i = 0; (i < count) && (i < data->nr); i++) {
2665                struct diffstat_file *file = data->files[i];
2666                uintmax_t change = file->added + file->deleted;
2667
2668                if (!file->is_interesting && (change == 0)) {
2669                        count++; /* not shown == room for one more */
2670                        continue;
2671                }
2672                fill_print_name(file);
2673                len = strlen(file->print_name);
2674                if (max_len < len)
2675                        max_len = len;
2676
2677                if (file->is_unmerged) {
2678                        /* "Unmerged" is 8 characters */
2679                        bin_width = bin_width < 8 ? 8 : bin_width;
2680                        continue;
2681                }
2682                if (file->is_binary) {
2683                        /* "Bin XXX -> YYY bytes" */
2684                        int w = 14 + decimal_width(file->added)
2685                                + decimal_width(file->deleted);
2686                        bin_width = bin_width < w ? w : bin_width;
2687                        /* Display change counts aligned with "Bin" */
2688                        number_width = 3;
2689                        continue;
2690                }
2691
2692                if (max_change < change)
2693                        max_change = change;
2694        }
2695        count = i; /* where we can stop scanning in data->files[] */
2696
2697        /*
2698         * We have width = stat_width or term_columns() columns total.
2699         * We want a maximum of min(max_len, stat_name_width) for the name part.
2700         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2701         * We also need 1 for " " and 4 + decimal_width(max_change)
2702         * for " | NNNN " and one the empty column at the end, altogether
2703         * 6 + decimal_width(max_change).
2704         *
2705         * If there's not enough space, we will use the smaller of
2706         * stat_name_width (if set) and 5/8*width for the filename,
2707         * and the rest for constant elements + graph part, but no more
2708         * than stat_graph_width for the graph part.
2709         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2710         * for the standard terminal size).
2711         *
2712         * In other words: stat_width limits the maximum width, and
2713         * stat_name_width fixes the maximum width of the filename,
2714         * and is also used to divide available columns if there
2715         * aren't enough.
2716         *
2717         * Binary files are displayed with "Bin XXX -> YYY bytes"
2718         * instead of the change count and graph. This part is treated
2719         * similarly to the graph part, except that it is not
2720         * "scaled". If total width is too small to accommodate the
2721         * guaranteed minimum width of the filename part and the
2722         * separators and this message, this message will "overflow"
2723         * making the line longer than the maximum width.
2724         */
2725
2726        if (options->stat_width == -1)
2727                width = term_columns() - strlen(line_prefix);
2728        else
2729                width = options->stat_width ? options->stat_width : 80;
2730        number_width = decimal_width(max_change) > number_width ?
2731                decimal_width(max_change) : number_width;
2732
2733        if (options->stat_graph_width == -1)
2734                options->stat_graph_width = diff_stat_graph_width;
2735
2736        /*
2737         * Guarantee 3/8*16==6 for the graph part
2738         * and 5/8*16==10 for the filename part
2739         */
2740        if (width < 16 + 6 + number_width)
2741                width = 16 + 6 + number_width;
2742
2743        /*
2744         * First assign sizes that are wanted, ignoring available width.
2745         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2746         * starting from "XXX" should fit in graph_width.
2747         */
2748        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2749        if (options->stat_graph_width &&
2750            options->stat_graph_width < graph_width)
2751                graph_width = options->stat_graph_width;
2752
2753        name_width = (options->stat_name_width > 0 &&
2754                      options->stat_name_width < max_len) ?
2755                options->stat_name_width : max_len;
2756
2757        /*
2758         * Adjust adjustable widths not to exceed maximum width
2759         */
2760        if (name_width + number_width + 6 + graph_width > width) {
2761                if (graph_width > width * 3/8 - number_width - 6) {
2762                        graph_width = width * 3/8 - number_width - 6;
2763                        if (graph_width < 6)
2764                                graph_width = 6;
2765                }
2766
2767                if (options->stat_graph_width &&
2768                    graph_width > options->stat_graph_width)
2769                        graph_width = options->stat_graph_width;
2770                if (name_width > width - number_width - 6 - graph_width)
2771                        name_width = width - number_width - 6 - graph_width;
2772                else
2773                        graph_width = width - number_width - 6 - name_width;
2774        }
2775
2776        /*
2777         * From here name_width is the width of the name area,
2778         * and graph_width is the width of the graph area.
2779         * max_change is used to scale graph properly.
2780         */
2781        for (i = 0; i < count; i++) {
2782                const char *prefix = "";
2783                struct diffstat_file *file = data->files[i];
2784                char *name = file->print_name;
2785                uintmax_t added = file->added;
2786                uintmax_t deleted = file->deleted;
2787                int name_len;
2788
2789                if (!file->is_interesting && (added + deleted == 0))
2790                        continue;
2791
2792                /*
2793                 * "scale" the filename
2794                 */
2795                len = name_width;
2796                name_len = strlen(name);
2797                if (name_width < name_len) {
2798                        char *slash;
2799                        prefix = "...";
2800                        len -= 3;
2801                        name += name_len - len;
2802                        slash = strchr(name, '/');
2803                        if (slash)
2804                                name = slash;
2805                }
2806
2807                if (file->is_binary) {
2808                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2809                        strbuf_addf(&out, " %*s", number_width, "Bin");
2810                        if (!added && !deleted) {
2811                                strbuf_addch(&out, '\n');
2812                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2813                                                 out.buf, out.len, 0);
2814                                strbuf_reset(&out);
2815                                continue;
2816                        }
2817                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2818                                del_c, deleted, reset);
2819                        strbuf_addstr(&out, " -> ");
2820                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2821                                add_c, added, reset);
2822                        strbuf_addstr(&out, " bytes\n");
2823                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2824                                         out.buf, out.len, 0);
2825                        strbuf_reset(&out);
2826                        continue;
2827                }
2828                else if (file->is_unmerged) {
2829                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2830                        strbuf_addstr(&out, " Unmerged\n");
2831                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2832                                         out.buf, out.len, 0);
2833                        strbuf_reset(&out);
2834                        continue;
2835                }
2836
2837                /*
2838                 * scale the add/delete
2839                 */
2840                add = added;
2841                del = deleted;
2842
2843                if (graph_width <= max_change) {
2844                        int total = scale_linear(add + del, graph_width, max_change);
2845                        if (total < 2 && add && del)
2846                                /* width >= 2 due to the sanity check */
2847                                total = 2;
2848                        if (add < del) {
2849                                add = scale_linear(add, graph_width, max_change);
2850                                del = total - add;
2851                        } else {
2852                                del = scale_linear(del, graph_width, max_change);
2853                                add = total - del;
2854                        }
2855                }
2856                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2857                strbuf_addf(&out, " %*"PRIuMAX"%s",
2858                        number_width, added + deleted,
2859                        added + deleted ? " " : "");
2860                show_graph(&out, '+', add, add_c, reset);
2861                show_graph(&out, '-', del, del_c, reset);
2862                strbuf_addch(&out, '\n');
2863                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2864                                 out.buf, out.len, 0);
2865                strbuf_reset(&out);
2866        }
2867
2868        for (i = 0; i < data->nr; i++) {
2869                struct diffstat_file *file = data->files[i];
2870                uintmax_t added = file->added;
2871                uintmax_t deleted = file->deleted;
2872
2873                if (file->is_unmerged ||
2874                    (!file->is_interesting && (added + deleted == 0))) {
2875                        total_files--;
2876                        continue;
2877                }
2878
2879                if (!file->is_binary) {
2880                        adds += added;
2881                        dels += deleted;
2882                }
2883                if (i < count)
2884                        continue;
2885                if (!extra_shown)
2886                        emit_diff_symbol(options,
2887                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2888                                         NULL, 0, 0);
2889                extra_shown = 1;
2890        }
2891
2892        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2893        strbuf_release(&out);
2894}
2895
2896static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2897{
2898        int i, adds = 0, dels = 0, total_files = data->nr;
2899
2900        if (data->nr == 0)
2901                return;
2902
2903        for (i = 0; i < data->nr; i++) {
2904                int added = data->files[i]->added;
2905                int deleted = data->files[i]->deleted;
2906
2907                if (data->files[i]->is_unmerged ||
2908                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2909                        total_files--;
2910                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2911                        adds += added;
2912                        dels += deleted;
2913                }
2914        }
2915        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2916}
2917
2918static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2919{
2920        int i;
2921
2922        if (data->nr == 0)
2923                return;
2924
2925        for (i = 0; i < data->nr; i++) {
2926                struct diffstat_file *file = data->files[i];
2927
2928                fprintf(options->file, "%s", diff_line_prefix(options));
2929
2930                if (file->is_binary)
2931                        fprintf(options->file, "-\t-\t");
2932                else
2933                        fprintf(options->file,
2934                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2935                                file->added, file->deleted);
2936                if (options->line_termination) {
2937                        fill_print_name(file);
2938                        if (!file->is_renamed)
2939                                write_name_quoted(file->name, options->file,
2940                                                  options->line_termination);
2941                        else {
2942                                fputs(file->print_name, options->file);
2943                                putc(options->line_termination, options->file);
2944                        }
2945                } else {
2946                        if (file->is_renamed) {
2947                                putc('\0', options->file);
2948                                write_name_quoted(file->from_name, options->file, '\0');
2949                        }
2950                        write_name_quoted(file->name, options->file, '\0');
2951                }
2952        }
2953}
2954
2955struct dirstat_file {
2956        const char *name;
2957        unsigned long changed;
2958};
2959
2960struct dirstat_dir {
2961        struct dirstat_file *files;
2962        int alloc, nr, permille, cumulative;
2963};
2964
2965static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2966                unsigned long changed, const char *base, int baselen)
2967{
2968        unsigned long sum_changes = 0;
2969        unsigned int sources = 0;
2970        const char *line_prefix = diff_line_prefix(opt);
2971
2972        while (dir->nr) {
2973                struct dirstat_file *f = dir->files;
2974                int namelen = strlen(f->name);
2975                unsigned long changes;
2976                char *slash;
2977
2978                if (namelen < baselen)
2979                        break;
2980                if (memcmp(f->name, base, baselen))
2981                        break;
2982                slash = strchr(f->name + baselen, '/');
2983                if (slash) {
2984                        int newbaselen = slash + 1 - f->name;
2985                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2986                        sources++;
2987                } else {
2988                        changes = f->changed;
2989                        dir->files++;
2990                        dir->nr--;
2991                        sources += 2;
2992                }
2993                sum_changes += changes;
2994        }
2995
2996        /*
2997         * We don't report dirstat's for
2998         *  - the top level
2999         *  - or cases where everything came from a single directory
3000         *    under this directory (sources == 1).
3001         */
3002        if (baselen && sources != 1) {
3003                if (sum_changes) {
3004                        int permille = sum_changes * 1000 / changed;
3005                        if (permille >= dir->permille) {
3006                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
3007                                        permille / 10, permille % 10, baselen, base);
3008                                if (!dir->cumulative)
3009                                        return 0;
3010                        }
3011                }
3012        }
3013        return sum_changes;
3014}
3015
3016static int dirstat_compare(const void *_a, const void *_b)
3017{
3018        const struct dirstat_file *a = _a;
3019        const struct dirstat_file *b = _b;
3020        return strcmp(a->name, b->name);
3021}
3022
3023static void show_dirstat(struct diff_options *options)
3024{
3025        int i;
3026        unsigned long changed;
3027        struct dirstat_dir dir;
3028        struct diff_queue_struct *q = &diff_queued_diff;
3029
3030        dir.files = NULL;
3031        dir.alloc = 0;
3032        dir.nr = 0;
3033        dir.permille = options->dirstat_permille;
3034        dir.cumulative = options->flags.dirstat_cumulative;
3035
3036        changed = 0;
3037        for (i = 0; i < q->nr; i++) {
3038                struct diff_filepair *p = q->queue[i];
3039                const char *name;
3040                unsigned long copied, added, damage;
3041
3042                name = p->two->path ? p->two->path : p->one->path;
3043
3044                if (p->one->oid_valid && p->two->oid_valid &&
3045                    oideq(&p->one->oid, &p->two->oid)) {
3046                        /*
3047                         * The SHA1 has not changed, so pre-/post-content is
3048                         * identical. We can therefore skip looking at the
3049                         * file contents altogether.
3050                         */
3051                        damage = 0;
3052                        goto found_damage;
3053                }
3054
3055                if (options->flags.dirstat_by_file) {
3056                        /*
3057                         * In --dirstat-by-file mode, we don't really need to
3058                         * look at the actual file contents at all.
3059                         * The fact that the SHA1 changed is enough for us to
3060                         * add this file to the list of results
3061                         * (with each file contributing equal damage).
3062                         */
3063                        damage = 1;
3064                        goto found_damage;
3065                }
3066
3067                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
3068                        diff_populate_filespec(options->repo, p->one, 0);
3069                        diff_populate_filespec(options->repo, p->two, 0);
3070                        diffcore_count_changes(options->repo,
3071                                               p->one, p->two, NULL, NULL,
3072                                               &copied, &added);
3073                        diff_free_filespec_data(p->one);
3074                        diff_free_filespec_data(p->two);
3075                } else if (DIFF_FILE_VALID(p->one)) {
3076                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3077                        copied = added = 0;
3078                        diff_free_filespec_data(p->one);
3079                } else if (DIFF_FILE_VALID(p->two)) {
3080                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3081                        copied = 0;
3082                        added = p->two->size;
3083                        diff_free_filespec_data(p->two);
3084                } else
3085                        continue;
3086
3087                /*
3088                 * Original minus copied is the removed material,
3089                 * added is the new material.  They are both damages
3090                 * made to the preimage.
3091                 * If the resulting damage is zero, we know that
3092                 * diffcore_count_changes() considers the two entries to
3093                 * be identical, but since the oid changed, we
3094                 * know that there must have been _some_ kind of change,
3095                 * so we force all entries to have damage > 0.
3096                 */
3097                damage = (p->one->size - copied) + added;
3098                if (!damage)
3099                        damage = 1;
3100
3101found_damage:
3102                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3103                dir.files[dir.nr].name = name;
3104                dir.files[dir.nr].changed = damage;
3105                changed += damage;
3106                dir.nr++;
3107        }
3108
3109        /* This can happen even with many files, if everything was renames */
3110        if (!changed)
3111                return;
3112
3113        /* Show all directories with more than x% of the changes */
3114        QSORT(dir.files, dir.nr, dirstat_compare);
3115        gather_dirstat(options, &dir, changed, "", 0);
3116}
3117
3118static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3119{
3120        int i;
3121        unsigned long changed;
3122        struct dirstat_dir dir;
3123
3124        if (data->nr == 0)
3125                return;
3126
3127        dir.files = NULL;
3128        dir.alloc = 0;
3129        dir.nr = 0;
3130        dir.permille = options->dirstat_permille;
3131        dir.cumulative = options->flags.dirstat_cumulative;
3132
3133        changed = 0;
3134        for (i = 0; i < data->nr; i++) {
3135                struct diffstat_file *file = data->files[i];
3136                unsigned long damage = file->added + file->deleted;
3137                if (file->is_binary)
3138                        /*
3139                         * binary files counts bytes, not lines. Must find some
3140                         * way to normalize binary bytes vs. textual lines.
3141                         * The following heuristic assumes that there are 64
3142                         * bytes per "line".
3143                         * This is stupid and ugly, but very cheap...
3144                         */
3145                        damage = DIV_ROUND_UP(damage, 64);
3146                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3147                dir.files[dir.nr].name = file->name;
3148                dir.files[dir.nr].changed = damage;
3149                changed += damage;
3150                dir.nr++;
3151        }
3152
3153        /* This can happen even with many files, if everything was renames */
3154        if (!changed)
3155                return;
3156
3157        /* Show all directories with more than x% of the changes */
3158        QSORT(dir.files, dir.nr, dirstat_compare);
3159        gather_dirstat(options, &dir, changed, "", 0);
3160}
3161
3162static void free_diffstat_info(struct diffstat_t *diffstat)
3163{
3164        int i;
3165        for (i = 0; i < diffstat->nr; i++) {
3166                struct diffstat_file *f = diffstat->files[i];
3167                free(f->print_name);
3168                free(f->name);
3169                free(f->from_name);
3170                free(f);
3171        }
3172        free(diffstat->files);
3173}
3174
3175struct checkdiff_t {
3176        const char *filename;
3177        int lineno;
3178        int conflict_marker_size;
3179        struct diff_options *o;
3180        unsigned ws_rule;
3181        unsigned status;
3182};
3183
3184static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3185{
3186        char firstchar;
3187        int cnt;
3188
3189        if (len < marker_size + 1)
3190                return 0;
3191        firstchar = line[0];
3192        switch (firstchar) {
3193        case '=': case '>': case '<': case '|':
3194                break;
3195        default:
3196                return 0;
3197        }
3198        for (cnt = 1; cnt < marker_size; cnt++)
3199                if (line[cnt] != firstchar)
3200                        return 0;
3201        /* line[1] thru line[marker_size-1] are same as firstchar */
3202        if (len < marker_size + 1 || !isspace(line[marker_size]))
3203                return 0;
3204        return 1;
3205}
3206
3207static void checkdiff_consume_hunk(void *priv,
3208                                   long ob, long on, long nb, long nn,
3209                                   const char *func, long funclen)
3210
3211{
3212        struct checkdiff_t *data = priv;
3213        data->lineno = nb - 1;
3214}
3215
3216static void checkdiff_consume(void *priv, char *line, unsigned long len)
3217{
3218        struct checkdiff_t *data = priv;
3219        int marker_size = data->conflict_marker_size;
3220        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3221        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3222        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3223        char *err;
3224        const char *line_prefix;
3225
3226        assert(data->o);
3227        line_prefix = diff_line_prefix(data->o);
3228
3229        if (line[0] == '+') {
3230                unsigned bad;
3231                data->lineno++;
3232                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3233                        data->status |= 1;
3234                        fprintf(data->o->file,
3235                                "%s%s:%d: leftover conflict marker\n",
3236                                line_prefix, data->filename, data->lineno);
3237                }
3238                bad = ws_check(line + 1, len - 1, data->ws_rule);
3239                if (!bad)
3240                        return;
3241                data->status |= bad;
3242                err = whitespace_error_string(bad);
3243                fprintf(data->o->file, "%s%s:%d: %s.\n",
3244                        line_prefix, data->filename, data->lineno, err);
3245                free(err);
3246                emit_line(data->o, set, reset, line, 1);
3247                ws_check_emit(line + 1, len - 1, data->ws_rule,
3248                              data->o->file, set, reset, ws);
3249        } else if (line[0] == ' ') {
3250                data->lineno++;
3251        }
3252}
3253
3254static unsigned char *deflate_it(char *data,
3255                                 unsigned long size,
3256                                 unsigned long *result_size)
3257{
3258        int bound;
3259        unsigned char *deflated;
3260        git_zstream stream;
3261
3262        git_deflate_init(&stream, zlib_compression_level);
3263        bound = git_deflate_bound(&stream, size);
3264        deflated = xmalloc(bound);
3265        stream.next_out = deflated;
3266        stream.avail_out = bound;
3267
3268        stream.next_in = (unsigned char *)data;
3269        stream.avail_in = size;
3270        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3271                ; /* nothing */
3272        git_deflate_end(&stream);
3273        *result_size = stream.total_out;
3274        return deflated;
3275}
3276
3277static void emit_binary_diff_body(struct diff_options *o,
3278                                  mmfile_t *one, mmfile_t *two)
3279{
3280        void *cp;
3281        void *delta;
3282        void *deflated;
3283        void *data;
3284        unsigned long orig_size;
3285        unsigned long delta_size;
3286        unsigned long deflate_size;
3287        unsigned long data_size;
3288
3289        /* We could do deflated delta, or we could do just deflated two,
3290         * whichever is smaller.
3291         */
3292        delta = NULL;
3293        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3294        if (one->size && two->size) {
3295                delta = diff_delta(one->ptr, one->size,
3296                                   two->ptr, two->size,
3297                                   &delta_size, deflate_size);
3298                if (delta) {
3299                        void *to_free = delta;
3300                        orig_size = delta_size;
3301                        delta = deflate_it(delta, delta_size, &delta_size);
3302                        free(to_free);
3303                }
3304        }
3305
3306        if (delta && delta_size < deflate_size) {
3307                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3308                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3309                                 s, strlen(s), 0);
3310                free(s);
3311                free(deflated);
3312                data = delta;
3313                data_size = delta_size;
3314        } else {
3315                char *s = xstrfmt("%lu", two->size);
3316                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3317                                 s, strlen(s), 0);
3318                free(s);
3319                free(delta);
3320                data = deflated;
3321                data_size = deflate_size;
3322        }
3323
3324        /* emit data encoded in base85 */
3325        cp = data;
3326        while (data_size) {
3327                int len;
3328                int bytes = (52 < data_size) ? 52 : data_size;
3329                char line[71];
3330                data_size -= bytes;
3331                if (bytes <= 26)
3332                        line[0] = bytes + 'A' - 1;
3333                else
3334                        line[0] = bytes - 26 + 'a' - 1;
3335                encode_85(line + 1, cp, bytes);
3336                cp = (char *) cp + bytes;
3337
3338                len = strlen(line);
3339                line[len++] = '\n';
3340                line[len] = '\0';
3341
3342                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3343                                 line, len, 0);
3344        }
3345        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3346        free(data);
3347}
3348
3349static void emit_binary_diff(struct diff_options *o,
3350                             mmfile_t *one, mmfile_t *two)
3351{
3352        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3353        emit_binary_diff_body(o, one, two);
3354        emit_binary_diff_body(o, two, one);
3355}
3356
3357int diff_filespec_is_binary(struct repository *r,
3358                            struct diff_filespec *one)
3359{
3360        if (one->is_binary == -1) {
3361                diff_filespec_load_driver(one, r->index);
3362                if (one->driver->binary != -1)
3363                        one->is_binary = one->driver->binary;
3364                else {
3365                        if (!one->data && DIFF_FILE_VALID(one))
3366                                diff_populate_filespec(r, one, CHECK_BINARY);
3367                        if (one->is_binary == -1 && one->data)
3368                                one->is_binary = buffer_is_binary(one->data,
3369                                                one->size);
3370                        if (one->is_binary == -1)
3371                                one->is_binary = 0;
3372                }
3373        }
3374        return one->is_binary;
3375}
3376
3377static const struct userdiff_funcname *
3378diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3379{
3380        diff_filespec_load_driver(one, o->repo->index);
3381        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3382}
3383
3384void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3385{
3386        if (!options->a_prefix)
3387                options->a_prefix = a;
3388        if (!options->b_prefix)
3389                options->b_prefix = b;
3390}
3391
3392struct userdiff_driver *get_textconv(struct repository *r,
3393                                     struct diff_filespec *one)
3394{
3395        if (!DIFF_FILE_VALID(one))
3396                return NULL;
3397
3398        diff_filespec_load_driver(one, r->index);
3399        return userdiff_get_textconv(r, one->driver);
3400}
3401
3402static void builtin_diff(const char *name_a,
3403                         const char *name_b,
3404                         struct diff_filespec *one,
3405                         struct diff_filespec *two,
3406                         const char *xfrm_msg,
3407                         int must_show_header,
3408                         struct diff_options *o,
3409                         int complete_rewrite)
3410{
3411        mmfile_t mf1, mf2;
3412        const char *lbl[2];
3413        char *a_one, *b_two;
3414        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3415        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3416        const char *a_prefix, *b_prefix;
3417        struct userdiff_driver *textconv_one = NULL;
3418        struct userdiff_driver *textconv_two = NULL;
3419        struct strbuf header = STRBUF_INIT;
3420        const char *line_prefix = diff_line_prefix(o);
3421
3422        diff_set_mnemonic_prefix(o, "a/", "b/");
3423        if (o->flags.reverse_diff) {
3424                a_prefix = o->b_prefix;
3425                b_prefix = o->a_prefix;
3426        } else {
3427                a_prefix = o->a_prefix;
3428                b_prefix = o->b_prefix;
3429        }
3430
3431        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3432            (!one->mode || S_ISGITLINK(one->mode)) &&
3433            (!two->mode || S_ISGITLINK(two->mode))) {
3434                show_submodule_summary(o, one->path ? one->path : two->path,
3435                                &one->oid, &two->oid,
3436                                two->dirty_submodule);
3437                return;
3438        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3439                   (!one->mode || S_ISGITLINK(one->mode)) &&
3440                   (!two->mode || S_ISGITLINK(two->mode))) {
3441                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3442                                &one->oid, &two->oid,
3443                                two->dirty_submodule);
3444                return;
3445        }
3446
3447        if (o->flags.allow_textconv) {
3448                textconv_one = get_textconv(o->repo, one);
3449                textconv_two = get_textconv(o->repo, two);
3450        }
3451
3452        /* Never use a non-valid filename anywhere if at all possible */
3453        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3454        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3455
3456        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3457        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3458        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3459        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3460        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3461        if (lbl[0][0] == '/') {
3462                /* /dev/null */
3463                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3464                if (xfrm_msg)
3465                        strbuf_addstr(&header, xfrm_msg);
3466                must_show_header = 1;
3467        }
3468        else if (lbl[1][0] == '/') {
3469                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3470                if (xfrm_msg)
3471                        strbuf_addstr(&header, xfrm_msg);
3472                must_show_header = 1;
3473        }
3474        else {
3475                if (one->mode != two->mode) {
3476                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3477                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3478                        must_show_header = 1;
3479                }
3480                if (xfrm_msg)
3481                        strbuf_addstr(&header, xfrm_msg);
3482
3483                /*
3484                 * we do not run diff between different kind
3485                 * of objects.
3486                 */
3487                if ((one->mode ^ two->mode) & S_IFMT)
3488                        goto free_ab_and_return;
3489                if (complete_rewrite &&
3490                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3491                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3492                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3493                                         header.buf, header.len, 0);
3494                        strbuf_reset(&header);
3495                        emit_rewrite_diff(name_a, name_b, one, two,
3496                                          textconv_one, textconv_two, o);
3497                        o->found_changes = 1;
3498                        goto free_ab_and_return;
3499                }
3500        }
3501
3502        if (o->irreversible_delete && lbl[1][0] == '/') {
3503                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3504                                 header.len, 0);
3505                strbuf_reset(&header);
3506                goto free_ab_and_return;
3507        } else if (!o->flags.text &&
3508                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3509                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3510                struct strbuf sb = STRBUF_INIT;
3511                if (!one->data && !two->data &&
3512                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3513                    !o->flags.binary) {
3514                        if (oideq(&one->oid, &two->oid)) {
3515                                if (must_show_header)
3516                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3517                                                         header.buf, header.len,
3518                                                         0);
3519                                goto free_ab_and_return;
3520                        }
3521                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3522                                         header.buf, header.len, 0);
3523                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3524                                    diff_line_prefix(o), lbl[0], lbl[1]);
3525                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3526                                         sb.buf, sb.len, 0);
3527                        strbuf_release(&sb);
3528                        goto free_ab_and_return;
3529                }
3530                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3531                    fill_mmfile(o->repo, &mf2, two) < 0)
3532                        die("unable to read files to diff");
3533                /* Quite common confusing case */
3534                if (mf1.size == mf2.size &&
3535                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3536                        if (must_show_header)
3537                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3538                                                 header.buf, header.len, 0);
3539                        goto free_ab_and_return;
3540                }
3541                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3542                strbuf_reset(&header);
3543                if (o->flags.binary)
3544                        emit_binary_diff(o, &mf1, &mf2);
3545                else {
3546                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3547                                    diff_line_prefix(o), lbl[0], lbl[1]);
3548                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3549                                         sb.buf, sb.len, 0);
3550                        strbuf_release(&sb);
3551                }
3552                o->found_changes = 1;
3553        } else {
3554                /* Crazy xdl interfaces.. */
3555                const char *diffopts;
3556                const char *v;
3557                xpparam_t xpp;
3558                xdemitconf_t xecfg;
3559                struct emit_callback ecbdata;
3560                const struct userdiff_funcname *pe;
3561
3562                if (must_show_header) {
3563                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3564                                         header.buf, header.len, 0);
3565                        strbuf_reset(&header);
3566                }
3567
3568                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3569                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3570
3571                pe = diff_funcname_pattern(o, one);
3572                if (!pe)
3573                        pe = diff_funcname_pattern(o, two);
3574
3575                memset(&xpp, 0, sizeof(xpp));
3576                memset(&xecfg, 0, sizeof(xecfg));
3577                memset(&ecbdata, 0, sizeof(ecbdata));
3578                if (o->flags.suppress_diff_headers)
3579                        lbl[0] = NULL;
3580                ecbdata.label_path = lbl;
3581                ecbdata.color_diff = want_color(o->use_color);
3582                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3583                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3584                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3585                ecbdata.opt = o;
3586                if (header.len && !o->flags.suppress_diff_headers)
3587                        ecbdata.header = &header;
3588                xpp.flags = o->xdl_opts;
3589                xpp.anchors = o->anchors;
3590                xpp.anchors_nr = o->anchors_nr;
3591                xecfg.ctxlen = o->context;
3592                xecfg.interhunkctxlen = o->interhunkcontext;
3593                xecfg.flags = XDL_EMIT_FUNCNAMES;
3594                if (o->flags.funccontext)
3595                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3596                if (pe)
3597                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3598
3599                diffopts = getenv("GIT_DIFF_OPTS");
3600                if (!diffopts)
3601                        ;
3602                else if (skip_prefix(diffopts, "--unified=", &v))
3603                        xecfg.ctxlen = strtoul(v, NULL, 10);
3604                else if (skip_prefix(diffopts, "-u", &v))
3605                        xecfg.ctxlen = strtoul(v, NULL, 10);
3606
3607                if (o->word_diff)
3608                        init_diff_words_data(&ecbdata, o, one, two);
3609                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3610                                  &ecbdata, &xpp, &xecfg))
3611                        die("unable to generate diff for %s", one->path);
3612                if (o->word_diff)
3613                        free_diff_words_data(&ecbdata);
3614                if (textconv_one)
3615                        free(mf1.ptr);
3616                if (textconv_two)
3617                        free(mf2.ptr);
3618                xdiff_clear_find_func(&xecfg);
3619        }
3620
3621 free_ab_and_return:
3622        strbuf_release(&header);
3623        diff_free_filespec_data(one);
3624        diff_free_filespec_data(two);
3625        free(a_one);
3626        free(b_two);
3627        return;
3628}
3629
3630static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3631{
3632        if (!is_renamed) {
3633                if (p->status == DIFF_STATUS_ADDED) {
3634                        if (S_ISLNK(p->two->mode))
3635                                return "new +l";
3636                        else if ((p->two->mode & 0777) == 0755)
3637                                return "new +x";
3638                        else
3639                                return "new";
3640                } else if (p->status == DIFF_STATUS_DELETED)
3641                        return "gone";
3642        }
3643        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3644                return "mode -l";
3645        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3646                return "mode +l";
3647        else if ((p->one->mode & 0777) == 0644 &&
3648                 (p->two->mode & 0777) == 0755)
3649                return "mode +x";
3650        else if ((p->one->mode & 0777) == 0755 &&
3651                 (p->two->mode & 0777) == 0644)
3652                return "mode -x";
3653        return NULL;
3654}
3655
3656static void builtin_diffstat(const char *name_a, const char *name_b,
3657                             struct diff_filespec *one,
3658                             struct diff_filespec *two,
3659                             struct diffstat_t *diffstat,
3660                             struct diff_options *o,
3661                             struct diff_filepair *p)
3662{
3663        mmfile_t mf1, mf2;
3664        struct diffstat_file *data;
3665        int same_contents;
3666        int complete_rewrite = 0;
3667
3668        if (!DIFF_PAIR_UNMERGED(p)) {
3669                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3670                        complete_rewrite = 1;
3671        }
3672
3673        data = diffstat_add(diffstat, name_a, name_b);
3674        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3675        if (o->flags.stat_with_summary)
3676                data->comments = get_compact_summary(p, data->is_renamed);
3677
3678        if (!one || !two) {
3679                data->is_unmerged = 1;
3680                return;
3681        }
3682
3683        same_contents = oideq(&one->oid, &two->oid);
3684
3685        if (diff_filespec_is_binary(o->repo, one) ||
3686            diff_filespec_is_binary(o->repo, two)) {
3687                data->is_binary = 1;
3688                if (same_contents) {
3689                        data->added = 0;
3690                        data->deleted = 0;
3691                } else {
3692                        data->added = diff_filespec_size(o->repo, two);
3693                        data->deleted = diff_filespec_size(o->repo, one);
3694                }
3695        }
3696
3697        else if (complete_rewrite) {
3698                diff_populate_filespec(o->repo, one, 0);
3699                diff_populate_filespec(o->repo, two, 0);
3700                data->deleted = count_lines(one->data, one->size);
3701                data->added = count_lines(two->data, two->size);
3702        }
3703
3704        else if (!same_contents) {
3705                /* Crazy xdl interfaces.. */
3706                xpparam_t xpp;
3707                xdemitconf_t xecfg;
3708
3709                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3710                    fill_mmfile(o->repo, &mf2, two) < 0)
3711                        die("unable to read files to diff");
3712
3713                memset(&xpp, 0, sizeof(xpp));
3714                memset(&xecfg, 0, sizeof(xecfg));
3715                xpp.flags = o->xdl_opts;
3716                xpp.anchors = o->anchors;
3717                xpp.anchors_nr = o->anchors_nr;
3718                xecfg.ctxlen = o->context;
3719                xecfg.interhunkctxlen = o->interhunkcontext;
3720                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3721                                  diffstat_consume, diffstat, &xpp, &xecfg))
3722                        die("unable to generate diffstat for %s", one->path);
3723        }
3724
3725        diff_free_filespec_data(one);
3726        diff_free_filespec_data(two);
3727}
3728
3729static void builtin_checkdiff(const char *name_a, const char *name_b,
3730                              const char *attr_path,
3731                              struct diff_filespec *one,
3732                              struct diff_filespec *two,
3733                              struct diff_options *o)
3734{
3735        mmfile_t mf1, mf2;
3736        struct checkdiff_t data;
3737
3738        if (!two)
3739                return;
3740
3741        memset(&data, 0, sizeof(data));
3742        data.filename = name_b ? name_b : name_a;
3743        data.lineno = 0;
3744        data.o = o;
3745        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3746        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3747
3748        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3749            fill_mmfile(o->repo, &mf2, two) < 0)
3750                die("unable to read files to diff");
3751
3752        /*
3753         * All the other codepaths check both sides, but not checking
3754         * the "old" side here is deliberate.  We are checking the newly
3755         * introduced changes, and as long as the "new" side is text, we
3756         * can and should check what it introduces.
3757         */
3758        if (diff_filespec_is_binary(o->repo, two))
3759                goto free_and_return;
3760        else {
3761                /* Crazy xdl interfaces.. */
3762                xpparam_t xpp;
3763                xdemitconf_t xecfg;
3764
3765                memset(&xpp, 0, sizeof(xpp));
3766                memset(&xecfg, 0, sizeof(xecfg));
3767                xecfg.ctxlen = 1; /* at least one context line */
3768                xpp.flags = 0;
3769                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3770                                  checkdiff_consume, &data,
3771                                  &xpp, &xecfg))
3772                        die("unable to generate checkdiff for %s", one->path);
3773
3774                if (data.ws_rule & WS_BLANK_AT_EOF) {
3775                        struct emit_callback ecbdata;
3776                        int blank_at_eof;
3777
3778                        ecbdata.ws_rule = data.ws_rule;
3779                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3780                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3781
3782                        if (blank_at_eof) {
3783                                static char *err;
3784                                if (!err)
3785                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3786                                fprintf(o->file, "%s:%d: %s.\n",
3787                                        data.filename, blank_at_eof, err);
3788                                data.status = 1; /* report errors */
3789                        }
3790                }
3791        }
3792 free_and_return:
3793        diff_free_filespec_data(one);
3794        diff_free_filespec_data(two);
3795        if (data.status)
3796                o->flags.check_failed = 1;
3797}
3798
3799struct diff_filespec *alloc_filespec(const char *path)
3800{
3801        struct diff_filespec *spec;
3802
3803        FLEXPTR_ALLOC_STR(spec, path, path);
3804        spec->count = 1;
3805        spec->is_binary = -1;
3806        return spec;
3807}
3808
3809void free_filespec(struct diff_filespec *spec)
3810{
3811        if (!--spec->count) {
3812                diff_free_filespec_data(spec);
3813                free(spec);
3814        }
3815}
3816
3817void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3818                   int oid_valid, unsigned short mode)
3819{
3820        if (mode) {
3821                spec->mode = canon_mode(mode);
3822                oidcpy(&spec->oid, oid);
3823                spec->oid_valid = oid_valid;
3824        }
3825}
3826
3827/*
3828 * Given a name and sha1 pair, if the index tells us the file in
3829 * the work tree has that object contents, return true, so that
3830 * prepare_temp_file() does not have to inflate and extract.
3831 */
3832static int reuse_worktree_file(struct index_state *istate,
3833                               const char *name,
3834                               const struct object_id *oid,
3835                               int want_file)
3836{
3837        const struct cache_entry *ce;
3838        struct stat st;
3839        int pos, len;
3840
3841        /*
3842         * We do not read the cache ourselves here, because the
3843         * benchmark with my previous version that always reads cache
3844         * shows that it makes things worse for diff-tree comparing
3845         * two linux-2.6 kernel trees in an already checked out work
3846         * tree.  This is because most diff-tree comparisons deal with
3847         * only a small number of files, while reading the cache is
3848         * expensive for a large project, and its cost outweighs the
3849         * savings we get by not inflating the object to a temporary
3850         * file.  Practically, this code only helps when we are used
3851         * by diff-cache --cached, which does read the cache before
3852         * calling us.
3853         */
3854        if (!istate->cache)
3855                return 0;
3856
3857        /* We want to avoid the working directory if our caller
3858         * doesn't need the data in a normal file, this system
3859         * is rather slow with its stat/open/mmap/close syscalls,
3860         * and the object is contained in a pack file.  The pack
3861         * is probably already open and will be faster to obtain
3862         * the data through than the working directory.  Loose
3863         * objects however would tend to be slower as they need
3864         * to be individually opened and inflated.
3865         */
3866        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3867                return 0;
3868
3869        /*
3870         * Similarly, if we'd have to convert the file contents anyway, that
3871         * makes the optimization not worthwhile.
3872         */
3873        if (!want_file && would_convert_to_git(istate, name))
3874                return 0;
3875
3876        len = strlen(name);
3877        pos = index_name_pos(istate, name, len);
3878        if (pos < 0)
3879                return 0;
3880        ce = istate->cache[pos];
3881
3882        /*
3883         * This is not the sha1 we are looking for, or
3884         * unreusable because it is not a regular file.
3885         */
3886        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3887                return 0;
3888
3889        /*
3890         * If ce is marked as "assume unchanged", there is no
3891         * guarantee that work tree matches what we are looking for.
3892         */
3893        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3894                return 0;
3895
3896        /*
3897         * If ce matches the file in the work tree, we can reuse it.
3898         */
3899        if (ce_uptodate(ce) ||
3900            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3901                return 1;
3902
3903        return 0;
3904}
3905
3906static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3907{
3908        struct strbuf buf = STRBUF_INIT;
3909        char *dirty = "";
3910
3911        /* Are we looking at the work tree? */
3912        if (s->dirty_submodule)
3913                dirty = "-dirty";
3914
3915        strbuf_addf(&buf, "Subproject commit %s%s\n",
3916                    oid_to_hex(&s->oid), dirty);
3917        s->size = buf.len;
3918        if (size_only) {
3919                s->data = NULL;
3920                strbuf_release(&buf);
3921        } else {
3922                s->data = strbuf_detach(&buf, NULL);
3923                s->should_free = 1;
3924        }
3925        return 0;
3926}
3927
3928/*
3929 * While doing rename detection and pickaxe operation, we may need to
3930 * grab the data for the blob (or file) for our own in-core comparison.
3931 * diff_filespec has data and size fields for this purpose.
3932 */
3933int diff_populate_filespec(struct repository *r,
3934                           struct diff_filespec *s,
3935                           unsigned int flags)
3936{
3937        int size_only = flags & CHECK_SIZE_ONLY;
3938        int err = 0;
3939        int conv_flags = global_conv_flags_eol;
3940        /*
3941         * demote FAIL to WARN to allow inspecting the situation
3942         * instead of refusing.
3943         */
3944        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3945                conv_flags = CONV_EOL_RNDTRP_WARN;
3946
3947        if (!DIFF_FILE_VALID(s))
3948                die("internal error: asking to populate invalid file.");
3949        if (S_ISDIR(s->mode))
3950                return -1;
3951
3952        if (s->data)
3953                return 0;
3954
3955        if (size_only && 0 < s->size)
3956                return 0;
3957
3958        if (S_ISGITLINK(s->mode))
3959                return diff_populate_gitlink(s, size_only);
3960
3961        if (!s->oid_valid ||
3962            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3963                struct strbuf buf = STRBUF_INIT;
3964                struct stat st;
3965                int fd;
3966
3967                if (lstat(s->path, &st) < 0) {
3968                err_empty:
3969                        err = -1;
3970                empty:
3971                        s->data = (char *)"";
3972                        s->size = 0;
3973                        return err;
3974                }
3975                s->size = xsize_t(st.st_size);
3976                if (!s->size)
3977                        goto empty;
3978                if (S_ISLNK(st.st_mode)) {
3979                        struct strbuf sb = STRBUF_INIT;
3980
3981                        if (strbuf_readlink(&sb, s->path, s->size))
3982                                goto err_empty;
3983                        s->size = sb.len;
3984                        s->data = strbuf_detach(&sb, NULL);
3985                        s->should_free = 1;
3986                        return 0;
3987                }
3988
3989                /*
3990                 * Even if the caller would be happy with getting
3991                 * only the size, we cannot return early at this
3992                 * point if the path requires us to run the content
3993                 * conversion.
3994                 */
3995                if (size_only && !would_convert_to_git(r->index, s->path))
3996                        return 0;
3997
3998                /*
3999                 * Note: this check uses xsize_t(st.st_size) that may
4000                 * not be the true size of the blob after it goes
4001                 * through convert_to_git().  This may not strictly be
4002                 * correct, but the whole point of big_file_threshold
4003                 * and is_binary check being that we want to avoid
4004                 * opening the file and inspecting the contents, this
4005                 * is probably fine.
4006                 */
4007                if ((flags & CHECK_BINARY) &&
4008                    s->size > big_file_threshold && s->is_binary == -1) {
4009                        s->is_binary = 1;
4010                        return 0;
4011                }
4012                fd = open(s->path, O_RDONLY);
4013                if (fd < 0)
4014                        goto err_empty;
4015                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
4016                close(fd);
4017                s->should_munmap = 1;
4018
4019                /*
4020                 * Convert from working tree format to canonical git format
4021                 */
4022                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
4023                        size_t size = 0;
4024                        munmap(s->data, s->size);
4025                        s->should_munmap = 0;
4026                        s->data = strbuf_detach(&buf, &size);
4027                        s->size = size;
4028                        s->should_free = 1;
4029                }
4030        }
4031        else {
4032                enum object_type type;
4033                if (size_only || (flags & CHECK_BINARY)) {
4034                        type = oid_object_info(r, &s->oid, &s->size);
4035                        if (type < 0)
4036                                die("unable to read %s",
4037                                    oid_to_hex(&s->oid));
4038                        if (size_only)
4039                                return 0;
4040                        if (s->size > big_file_threshold && s->is_binary == -1) {
4041                                s->is_binary = 1;
4042                                return 0;
4043                        }
4044                }
4045                s->data = read_object_file(&s->oid, &type, &s->size);
4046                if (!s->data)
4047                        die("unable to read %s", oid_to_hex(&s->oid));
4048                s->should_free = 1;
4049        }
4050        return 0;
4051}
4052
4053void diff_free_filespec_blob(struct diff_filespec *s)
4054{
4055        if (s->should_free)
4056                free(s->data);
4057        else if (s->should_munmap)
4058                munmap(s->data, s->size);
4059
4060        if (s->should_free || s->should_munmap) {
4061                s->should_free = s->should_munmap = 0;
4062                s->data = NULL;
4063        }
4064}
4065
4066void diff_free_filespec_data(struct diff_filespec *s)
4067{
4068        diff_free_filespec_blob(s);
4069        FREE_AND_NULL(s->cnt_data);
4070}
4071
4072static void prep_temp_blob(struct index_state *istate,
4073                           const char *path, struct diff_tempfile *temp,
4074                           void *blob,
4075                           unsigned long size,
4076                           const struct object_id *oid,
4077                           int mode)
4078{
4079        struct strbuf buf = STRBUF_INIT;
4080        struct strbuf tempfile = STRBUF_INIT;
4081        char *path_dup = xstrdup(path);
4082        const char *base = basename(path_dup);
4083
4084        /* Generate "XXXXXX_basename.ext" */
4085        strbuf_addstr(&tempfile, "XXXXXX_");
4086        strbuf_addstr(&tempfile, base);
4087
4088        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4089        if (!temp->tempfile)
4090                die_errno("unable to create temp-file");
4091        if (convert_to_working_tree(istate, path,
4092                        (const char *)blob, (size_t)size, &buf)) {
4093                blob = buf.buf;
4094                size = buf.len;
4095        }
4096        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4097            close_tempfile_gently(temp->tempfile))
4098                die_errno("unable to write temp-file");
4099        temp->name = get_tempfile_path(temp->tempfile);
4100        oid_to_hex_r(temp->hex, oid);
4101        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4102        strbuf_release(&buf);
4103        strbuf_release(&tempfile);
4104        free(path_dup);
4105}
4106
4107static struct diff_tempfile *prepare_temp_file(struct repository *r,
4108                                               const char *name,
4109                                               struct diff_filespec *one)
4110{
4111        struct diff_tempfile *temp = claim_diff_tempfile();
4112
4113        if (!DIFF_FILE_VALID(one)) {
4114        not_a_valid_file:
4115                /* A '-' entry produces this for file-2, and
4116                 * a '+' entry produces this for file-1.
4117                 */
4118                temp->name = "/dev/null";
4119                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4120                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4121                return temp;
4122        }
4123
4124        if (!S_ISGITLINK(one->mode) &&
4125            (!one->oid_valid ||
4126             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4127                struct stat st;
4128                if (lstat(name, &st) < 0) {
4129                        if (errno == ENOENT)
4130                                goto not_a_valid_file;
4131                        die_errno("stat(%s)", name);
4132                }
4133                if (S_ISLNK(st.st_mode)) {
4134                        struct strbuf sb = STRBUF_INIT;
4135                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4136                                die_errno("readlink(%s)", name);
4137                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4138                                       (one->oid_valid ?
4139                                        &one->oid : &null_oid),
4140                                       (one->oid_valid ?
4141                                        one->mode : S_IFLNK));
4142                        strbuf_release(&sb);
4143                }
4144                else {
4145                        /* we can borrow from the file in the work tree */
4146                        temp->name = name;
4147                        if (!one->oid_valid)
4148                                oid_to_hex_r(temp->hex, &null_oid);
4149                        else
4150                                oid_to_hex_r(temp->hex, &one->oid);
4151                        /* Even though we may sometimes borrow the
4152                         * contents from the work tree, we always want
4153                         * one->mode.  mode is trustworthy even when
4154                         * !(one->oid_valid), as long as
4155                         * DIFF_FILE_VALID(one).
4156                         */
4157                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4158                }
4159                return temp;
4160        }
4161        else {
4162                if (diff_populate_filespec(r, one, 0))
4163                        die("cannot read data blob for %s", one->path);
4164                prep_temp_blob(r->index, name, temp,
4165                               one->data, one->size,
4166                               &one->oid, one->mode);
4167        }
4168        return temp;
4169}
4170
4171static void add_external_diff_name(struct repository *r,
4172                                   struct argv_array *argv,
4173                                   const char *name,
4174                                   struct diff_filespec *df)
4175{
4176        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4177        argv_array_push(argv, temp->name);
4178        argv_array_push(argv, temp->hex);
4179        argv_array_push(argv, temp->mode);
4180}
4181
4182/* An external diff command takes:
4183 *
4184 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4185 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4186 *
4187 */
4188static void run_external_diff(const char *pgm,
4189                              const char *name,
4190                              const char *other,
4191                              struct diff_filespec *one,
4192                              struct diff_filespec *two,
4193                              const char *xfrm_msg,
4194                              int complete_rewrite,
4195                              struct diff_options *o)
4196{
4197        struct argv_array argv = ARGV_ARRAY_INIT;
4198        struct argv_array env = ARGV_ARRAY_INIT;
4199        struct diff_queue_struct *q = &diff_queued_diff;
4200
4201        argv_array_push(&argv, pgm);
4202        argv_array_push(&argv, name);
4203
4204        if (one && two) {
4205                add_external_diff_name(o->repo, &argv, name, one);
4206                if (!other)
4207                        add_external_diff_name(o->repo, &argv, name, two);
4208                else {
4209                        add_external_diff_name(o->repo, &argv, other, two);
4210                        argv_array_push(&argv, other);
4211                        argv_array_push(&argv, xfrm_msg);
4212                }
4213        }
4214
4215        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4216        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4217
4218        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4219                die(_("external diff died, stopping at %s"), name);
4220
4221        remove_tempfile();
4222        argv_array_clear(&argv);
4223        argv_array_clear(&env);
4224}
4225
4226static int similarity_index(struct diff_filepair *p)
4227{
4228        return p->score * 100 / MAX_SCORE;
4229}
4230
4231static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4232{
4233        if (startup_info->have_repository)
4234                return find_unique_abbrev(oid, abbrev);
4235        else {
4236                char *hex = oid_to_hex(oid);
4237                if (abbrev < 0)
4238                        abbrev = FALLBACK_DEFAULT_ABBREV;
4239                if (abbrev > the_hash_algo->hexsz)
4240                        BUG("oid abbreviation out of range: %d", abbrev);
4241                if (abbrev)
4242                        hex[abbrev] = '\0';
4243                return hex;
4244        }
4245}
4246
4247static void fill_metainfo(struct strbuf *msg,
4248                          const char *name,
4249                          const char *other,
4250                          struct diff_filespec *one,
4251                          struct diff_filespec *two,
4252                          struct diff_options *o,
4253                          struct diff_filepair *p,
4254                          int *must_show_header,
4255                          int use_color)
4256{
4257        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4258        const char *reset = diff_get_color(use_color, DIFF_RESET);
4259        const char *line_prefix = diff_line_prefix(o);
4260
4261        *must_show_header = 1;
4262        strbuf_init(msg, PATH_MAX * 2 + 300);
4263        switch (p->status) {
4264        case DIFF_STATUS_COPIED:
4265                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4266                            line_prefix, set, similarity_index(p));
4267                strbuf_addf(msg, "%s\n%s%scopy from ",
4268                            reset,  line_prefix, set);
4269                quote_c_style(name, msg, NULL, 0);
4270                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4271                quote_c_style(other, msg, NULL, 0);
4272                strbuf_addf(msg, "%s\n", reset);
4273                break;
4274        case DIFF_STATUS_RENAMED:
4275                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4276                            line_prefix, set, similarity_index(p));
4277                strbuf_addf(msg, "%s\n%s%srename from ",
4278                            reset, line_prefix, set);
4279                quote_c_style(name, msg, NULL, 0);
4280                strbuf_addf(msg, "%s\n%s%srename to ",
4281                            reset, line_prefix, set);
4282                quote_c_style(other, msg, NULL, 0);
4283                strbuf_addf(msg, "%s\n", reset);
4284                break;
4285        case DIFF_STATUS_MODIFIED:
4286                if (p->score) {
4287                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4288                                    line_prefix,
4289                                    set, similarity_index(p), reset);
4290                        break;
4291                }
4292                /* fallthru */
4293        default:
4294                *must_show_header = 0;
4295        }
4296        if (one && two && !oideq(&one->oid, &two->oid)) {
4297                const unsigned hexsz = the_hash_algo->hexsz;
4298                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4299
4300                if (o->flags.binary) {
4301                        mmfile_t mf;
4302                        if ((!fill_mmfile(o->repo, &mf, one) &&
4303                             diff_filespec_is_binary(o->repo, one)) ||
4304                            (!fill_mmfile(o->repo, &mf, two) &&
4305                             diff_filespec_is_binary(o->repo, two)))
4306                                abbrev = hexsz;
4307                }
4308                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4309                            diff_abbrev_oid(&one->oid, abbrev),
4310                            diff_abbrev_oid(&two->oid, abbrev));
4311                if (one->mode == two->mode)
4312                        strbuf_addf(msg, " %06o", one->mode);
4313                strbuf_addf(msg, "%s\n", reset);
4314        }
4315}
4316
4317static void run_diff_cmd(const char *pgm,
4318                         const char *name,
4319                         const char *other,
4320                         const char *attr_path,
4321                         struct diff_filespec *one,
4322                         struct diff_filespec *two,
4323                         struct strbuf *msg,
4324                         struct diff_options *o,
4325                         struct diff_filepair *p)
4326{
4327        const char *xfrm_msg = NULL;
4328        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4329        int must_show_header = 0;
4330
4331
4332        if (o->flags.allow_external) {
4333                struct userdiff_driver *drv;
4334
4335                drv = userdiff_find_by_path(o->repo->index, attr_path);
4336                if (drv && drv->external)
4337                        pgm = drv->external;
4338        }
4339
4340        if (msg) {
4341                /*
4342                 * don't use colors when the header is intended for an
4343                 * external diff driver
4344                 */
4345                fill_metainfo(msg, name, other, one, two, o, p,
4346                              &must_show_header,
4347                              want_color(o->use_color) && !pgm);
4348                xfrm_msg = msg->len ? msg->buf : NULL;
4349        }
4350
4351        if (pgm) {
4352                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4353                                  complete_rewrite, o);
4354                return;
4355        }
4356        if (one && two)
4357                builtin_diff(name, other ? other : name,
4358                             one, two, xfrm_msg, must_show_header,
4359                             o, complete_rewrite);
4360        else
4361                fprintf(o->file, "* Unmerged path %s\n", name);
4362}
4363
4364static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4365{
4366        if (DIFF_FILE_VALID(one)) {
4367                if (!one->oid_valid) {
4368                        struct stat st;
4369                        if (one->is_stdin) {
4370                                oidclr(&one->oid);
4371                                return;
4372                        }
4373                        if (lstat(one->path, &st) < 0)
4374                                die_errno("stat '%s'", one->path);
4375                        if (index_path(istate, &one->oid, one->path, &st, 0))
4376                                die("cannot hash %s", one->path);
4377                }
4378        }
4379        else
4380                oidclr(&one->oid);
4381}
4382
4383static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4384{
4385        /* Strip the prefix but do not molest /dev/null and absolute paths */
4386        if (*namep && !is_absolute_path(*namep)) {
4387                *namep += prefix_length;
4388                if (**namep == '/')
4389                        ++*namep;
4390        }
4391        if (*otherp && !is_absolute_path(*otherp)) {
4392                *otherp += prefix_length;
4393                if (**otherp == '/')
4394                        ++*otherp;
4395        }
4396}
4397
4398static void run_diff(struct diff_filepair *p, struct diff_options *o)
4399{
4400        const char *pgm = external_diff();
4401        struct strbuf msg;
4402        struct diff_filespec *one = p->one;
4403        struct diff_filespec *two = p->two;
4404        const char *name;
4405        const char *other;
4406        const char *attr_path;
4407
4408        name  = one->path;
4409        other = (strcmp(name, two->path) ? two->path : NULL);
4410        attr_path = name;
4411        if (o->prefix_length)
4412                strip_prefix(o->prefix_length, &name, &other);
4413
4414        if (!o->flags.allow_external)
4415                pgm = NULL;
4416
4417        if (DIFF_PAIR_UNMERGED(p)) {
4418                run_diff_cmd(pgm, name, NULL, attr_path,
4419                             NULL, NULL, NULL, o, p);
4420                return;
4421        }
4422
4423        diff_fill_oid_info(one, o->repo->index);
4424        diff_fill_oid_info(two, o->repo->index);
4425
4426        if (!pgm &&
4427            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4428            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4429                /*
4430                 * a filepair that changes between file and symlink
4431                 * needs to be split into deletion and creation.
4432                 */
4433                struct diff_filespec *null = alloc_filespec(two->path);
4434                run_diff_cmd(NULL, name, other, attr_path,
4435                             one, null, &msg,
4436                             o, p);
4437                free(null);
4438                strbuf_release(&msg);
4439
4440                null = alloc_filespec(one->path);
4441                run_diff_cmd(NULL, name, other, attr_path,
4442                             null, two, &msg, o, p);
4443                free(null);
4444        }
4445        else
4446                run_diff_cmd(pgm, name, other, attr_path,
4447                             one, two, &msg, o, p);
4448
4449        strbuf_release(&msg);
4450}
4451
4452static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4453                         struct diffstat_t *diffstat)
4454{
4455        const char *name;
4456        const char *other;
4457
4458        if (DIFF_PAIR_UNMERGED(p)) {
4459                /* unmerged */
4460                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4461                                 diffstat, o, p);
4462                return;
4463        }
4464
4465        name = p->one->path;
4466        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4467
4468        if (o->prefix_length)
4469                strip_prefix(o->prefix_length, &name, &other);
4470
4471        diff_fill_oid_info(p->one, o->repo->index);
4472        diff_fill_oid_info(p->two, o->repo->index);
4473
4474        builtin_diffstat(name, other, p->one, p->two,
4475                         diffstat, o, p);
4476}
4477
4478static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4479{
4480        const char *name;
4481        const char *other;
4482        const char *attr_path;
4483
4484        if (DIFF_PAIR_UNMERGED(p)) {
4485                /* unmerged */
4486                return;
4487        }
4488
4489        name = p->one->path;
4490        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4491        attr_path = other ? other : name;
4492
4493        if (o->prefix_length)
4494                strip_prefix(o->prefix_length, &name, &other);
4495
4496        diff_fill_oid_info(p->one, o->repo->index);
4497        diff_fill_oid_info(p->two, o->repo->index);
4498
4499        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4500}
4501
4502void repo_diff_setup(struct repository *r, struct diff_options *options)
4503{
4504        memcpy(options, &default_diff_options, sizeof(*options));
4505
4506        options->file = stdout;
4507        options->repo = r;
4508
4509        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4510        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4511        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4512        options->abbrev = DEFAULT_ABBREV;
4513        options->line_termination = '\n';
4514        options->break_opt = -1;
4515        options->rename_limit = -1;
4516        options->dirstat_permille = diff_dirstat_permille_default;
4517        options->context = diff_context_default;
4518        options->interhunkcontext = diff_interhunk_context_default;
4519        options->ws_error_highlight = ws_error_highlight_default;
4520        options->flags.rename_empty = 1;
4521        options->objfind = NULL;
4522
4523        /* pathchange left =NULL by default */
4524        options->change = diff_change;
4525        options->add_remove = diff_addremove;
4526        options->use_color = diff_use_color_default;
4527        options->detect_rename = diff_detect_rename_default;
4528        options->xdl_opts |= diff_algorithm;
4529        if (diff_indent_heuristic)
4530                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4531
4532        options->orderfile = diff_order_file_cfg;
4533
4534        if (diff_no_prefix) {
4535                options->a_prefix = options->b_prefix = "";
4536        } else if (!diff_mnemonic_prefix) {
4537                options->a_prefix = "a/";
4538                options->b_prefix = "b/";
4539        }
4540
4541        options->color_moved = diff_color_moved_default;
4542        options->color_moved_ws_handling = diff_color_moved_ws_default;
4543}
4544
4545void diff_setup_done(struct diff_options *options)
4546{
4547        unsigned check_mask = DIFF_FORMAT_NAME |
4548                              DIFF_FORMAT_NAME_STATUS |
4549                              DIFF_FORMAT_CHECKDIFF |
4550                              DIFF_FORMAT_NO_OUTPUT;
4551        /*
4552         * This must be signed because we're comparing against a potentially
4553         * negative value.
4554         */
4555        const int hexsz = the_hash_algo->hexsz;
4556
4557        if (options->set_default)
4558                options->set_default(options);
4559
4560        if (HAS_MULTI_BITS(options->output_format & check_mask))
4561                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4562
4563        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4564                die(_("-G, -S and --find-object are mutually exclusive"));
4565
4566        /*
4567         * Most of the time we can say "there are changes"
4568         * only by checking if there are changed paths, but
4569         * --ignore-whitespace* options force us to look
4570         * inside contents.
4571         */
4572
4573        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4574                options->flags.diff_from_contents = 1;
4575        else
4576                options->flags.diff_from_contents = 0;
4577
4578        if (options->flags.find_copies_harder)
4579                options->detect_rename = DIFF_DETECT_COPY;
4580
4581        if (!options->flags.relative_name)
4582                options->prefix = NULL;
4583        if (options->prefix)
4584                options->prefix_length = strlen(options->prefix);
4585        else
4586                options->prefix_length = 0;
4587
4588        if (options->output_format & (DIFF_FORMAT_NAME |
4589                                      DIFF_FORMAT_NAME_STATUS |
4590                                      DIFF_FORMAT_CHECKDIFF |
4591                                      DIFF_FORMAT_NO_OUTPUT))
4592                options->output_format &= ~(DIFF_FORMAT_RAW |
4593                                            DIFF_FORMAT_NUMSTAT |
4594                                            DIFF_FORMAT_DIFFSTAT |
4595                                            DIFF_FORMAT_SHORTSTAT |
4596                                            DIFF_FORMAT_DIRSTAT |
4597                                            DIFF_FORMAT_SUMMARY |
4598                                            DIFF_FORMAT_PATCH);
4599
4600        /*
4601         * These cases always need recursive; we do not drop caller-supplied
4602         * recursive bits for other formats here.
4603         */
4604        if (options->output_format & (DIFF_FORMAT_PATCH |
4605                                      DIFF_FORMAT_NUMSTAT |
4606                                      DIFF_FORMAT_DIFFSTAT |
4607                                      DIFF_FORMAT_SHORTSTAT |
4608                                      DIFF_FORMAT_DIRSTAT |
4609                                      DIFF_FORMAT_SUMMARY |
4610                                      DIFF_FORMAT_CHECKDIFF))
4611                options->flags.recursive = 1;
4612        /*
4613         * Also pickaxe would not work very well if you do not say recursive
4614         */
4615        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4616                options->flags.recursive = 1;
4617        /*
4618         * When patches are generated, submodules diffed against the work tree
4619         * must be checked for dirtiness too so it can be shown in the output
4620         */
4621        if (options->output_format & DIFF_FORMAT_PATCH)
4622                options->flags.dirty_submodules = 1;
4623
4624        if (options->detect_rename && options->rename_limit < 0)
4625                options->rename_limit = diff_rename_limit_default;
4626        if (hexsz < options->abbrev)
4627                options->abbrev = hexsz; /* full */
4628
4629        /*
4630         * It does not make sense to show the first hit we happened
4631         * to have found.  It does not make sense not to return with
4632         * exit code in such a case either.
4633         */
4634        if (options->flags.quick) {
4635                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4636                options->flags.exit_with_status = 1;
4637        }
4638
4639        options->diff_path_counter = 0;
4640
4641        if (options->flags.follow_renames && options->pathspec.nr != 1)
4642                die(_("--follow requires exactly one pathspec"));
4643
4644        if (!options->use_color || external_diff())
4645                options->color_moved = 0;
4646}
4647
4648static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4649{
4650        char c, *eq;
4651        int len;
4652
4653        if (*arg != '-')
4654                return 0;
4655        c = *++arg;
4656        if (!c)
4657                return 0;
4658        if (c == arg_short) {
4659                c = *++arg;
4660                if (!c)
4661                        return 1;
4662                if (val && isdigit(c)) {
4663                        char *end;
4664                        int n = strtoul(arg, &end, 10);
4665                        if (*end)
4666                                return 0;
4667                        *val = n;
4668                        return 1;
4669                }
4670                return 0;
4671        }
4672        if (c != '-')
4673                return 0;
4674        arg++;
4675        eq = strchrnul(arg, '=');
4676        len = eq - arg;
4677        if (!len || strncmp(arg, arg_long, len))
4678                return 0;
4679        if (*eq) {
4680                int n;
4681                char *end;
4682                if (!isdigit(*++eq))
4683                        return 0;
4684                n = strtoul(eq, &end, 10);
4685                if (*end)
4686                        return 0;
4687                *val = n;
4688        }
4689        return 1;
4690}
4691
4692static int diff_scoreopt_parse(const char *opt);
4693
4694static inline int short_opt(char opt, const char **argv,
4695                            const char **optarg)
4696{
4697        const char *arg = argv[0];
4698        if (arg[0] != '-' || arg[1] != opt)
4699                return 0;
4700        if (arg[2] != '\0') {
4701                *optarg = arg + 2;
4702                return 1;
4703        }
4704        if (!argv[1])
4705                die("Option '%c' requires a value", opt);
4706        *optarg = argv[1];
4707        return 2;
4708}
4709
4710int parse_long_opt(const char *opt, const char **argv,
4711                   const char **optarg)
4712{
4713        const char *arg = argv[0];
4714        if (!skip_prefix(arg, "--", &arg))
4715                return 0;
4716        if (!skip_prefix(arg, opt, &arg))
4717                return 0;
4718        if (*arg == '=') { /* stuck form: --option=value */
4719                *optarg = arg + 1;
4720                return 1;
4721        }
4722        if (*arg != '\0')
4723                return 0;
4724        /* separate form: --option value */
4725        if (!argv[1])
4726                die("Option '--%s' requires a value", opt);
4727        *optarg = argv[1];
4728        return 2;
4729}
4730
4731static int stat_opt(struct diff_options *options, const char **av)
4732{
4733        const char *arg = av[0];
4734        char *end;
4735        int width = options->stat_width;
4736        int name_width = options->stat_name_width;
4737        int graph_width = options->stat_graph_width;
4738        int count = options->stat_count;
4739        int argcount = 1;
4740
4741        if (!skip_prefix(arg, "--stat", &arg))
4742                BUG("stat option does not begin with --stat: %s", arg);
4743        end = (char *)arg;
4744
4745        switch (*arg) {
4746        case '-':
4747                if (skip_prefix(arg, "-width", &arg)) {
4748                        if (*arg == '=')
4749                                width = strtoul(arg + 1, &end, 10);
4750                        else if (!*arg && !av[1])
4751                                die_want_option("--stat-width");
4752                        else if (!*arg) {
4753                                width = strtoul(av[1], &end, 10);
4754                                argcount = 2;
4755                        }
4756                } else if (skip_prefix(arg, "-name-width", &arg)) {
4757                        if (*arg == '=')
4758                                name_width = strtoul(arg + 1, &end, 10);
4759                        else if (!*arg && !av[1])
4760                                die_want_option("--stat-name-width");
4761                        else if (!*arg) {
4762                                name_width = strtoul(av[1], &end, 10);
4763                                argcount = 2;
4764                        }
4765                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4766                        if (*arg == '=')
4767                                graph_width = strtoul(arg + 1, &end, 10);
4768                        else if (!*arg && !av[1])
4769                                die_want_option("--stat-graph-width");
4770                        else if (!*arg) {
4771                                graph_width = strtoul(av[1], &end, 10);
4772                                argcount = 2;
4773                        }
4774                } else if (skip_prefix(arg, "-count", &arg)) {
4775                        if (*arg == '=')
4776                                count = strtoul(arg + 1, &end, 10);
4777                        else if (!*arg && !av[1])
4778                                die_want_option("--stat-count");
4779                        else if (!*arg) {
4780                                count = strtoul(av[1], &end, 10);
4781                                argcount = 2;
4782                        }
4783                }
4784                break;
4785        case '=':
4786                width = strtoul(arg+1, &end, 10);
4787                if (*end == ',')
4788                        name_width = strtoul(end+1, &end, 10);
4789                if (*end == ',')
4790                        count = strtoul(end+1, &end, 10);
4791        }
4792
4793        /* Important! This checks all the error cases! */
4794        if (*end)
4795                return 0;
4796        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4797        options->stat_name_width = name_width;
4798        options->stat_graph_width = graph_width;
4799        options->stat_width = width;
4800        options->stat_count = count;
4801        return argcount;
4802}
4803
4804static int parse_dirstat_opt(struct diff_options *options, const char *params)
4805{
4806        struct strbuf errmsg = STRBUF_INIT;
4807        if (parse_dirstat_params(options, params, &errmsg))
4808                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4809                    errmsg.buf);
4810        strbuf_release(&errmsg);
4811        /*
4812         * The caller knows a dirstat-related option is given from the command
4813         * line; allow it to say "return this_function();"
4814         */
4815        options->output_format |= DIFF_FORMAT_DIRSTAT;
4816        return 1;
4817}
4818
4819static int parse_submodule_opt(struct diff_options *options, const char *value)
4820{
4821        if (parse_submodule_params(options, value))
4822                die(_("Failed to parse --submodule option parameter: '%s'"),
4823                        value);
4824        return 1;
4825}
4826
4827static const char diff_status_letters[] = {
4828        DIFF_STATUS_ADDED,
4829        DIFF_STATUS_COPIED,
4830        DIFF_STATUS_DELETED,
4831        DIFF_STATUS_MODIFIED,
4832        DIFF_STATUS_RENAMED,
4833        DIFF_STATUS_TYPE_CHANGED,
4834        DIFF_STATUS_UNKNOWN,
4835        DIFF_STATUS_UNMERGED,
4836        DIFF_STATUS_FILTER_AON,
4837        DIFF_STATUS_FILTER_BROKEN,
4838        '\0',
4839};
4840
4841static unsigned int filter_bit['Z' + 1];
4842
4843static void prepare_filter_bits(void)
4844{
4845        int i;
4846
4847        if (!filter_bit[DIFF_STATUS_ADDED]) {
4848                for (i = 0; diff_status_letters[i]; i++)
4849                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4850        }
4851}
4852
4853static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4854{
4855        return opt->filter & filter_bit[(int) status];
4856}
4857
4858static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4859{
4860        int i, optch;
4861
4862        prepare_filter_bits();
4863
4864        /*
4865         * If there is a negation e.g. 'd' in the input, and we haven't
4866         * initialized the filter field with another --diff-filter, start
4867         * from full set of bits, except for AON.
4868         */
4869        if (!opt->filter) {
4870                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4871                        if (optch < 'a' || 'z' < optch)
4872                                continue;
4873                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4874                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4875                        break;
4876                }
4877        }
4878
4879        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4880                unsigned int bit;
4881                int negate;
4882
4883                if ('a' <= optch && optch <= 'z') {
4884                        negate = 1;
4885                        optch = toupper(optch);
4886                } else {
4887                        negate = 0;
4888                }
4889
4890                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4891                if (!bit)
4892                        return optarg[i];
4893                if (negate)
4894                        opt->filter &= ~bit;
4895                else
4896                        opt->filter |= bit;
4897        }
4898        return 0;
4899}
4900
4901static void enable_patch_output(int *fmt)
4902{
4903        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4904        *fmt |= DIFF_FORMAT_PATCH;
4905}
4906
4907static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4908{
4909        int val = parse_ws_error_highlight(arg);
4910
4911        if (val < 0) {
4912                error("unknown value after ws-error-highlight=%.*s",
4913                      -1 - val, arg);
4914                return 0;
4915        }
4916        opt->ws_error_highlight = val;
4917        return 1;
4918}
4919
4920static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4921{
4922        struct object_id oid;
4923
4924        if (get_oid(arg, &oid))
4925                return error("unable to resolve '%s'", arg);
4926
4927        if (!opt->objfind)
4928                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4929
4930        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4931        opt->flags.recursive = 1;
4932        opt->flags.tree_in_recursive = 1;
4933        oidset_insert(opt->objfind, &oid);
4934        return 1;
4935}
4936
4937int diff_opt_parse(struct diff_options *options,
4938                   const char **av, int ac, const char *prefix)
4939{
4940        const char *arg = av[0];
4941        const char *optarg;
4942        int argcount;
4943
4944        if (!prefix)
4945                prefix = "";
4946
4947        /* Output format options */
4948        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4949            || opt_arg(arg, 'U', "unified", &options->context))
4950                enable_patch_output(&options->output_format);
4951        else if (!strcmp(arg, "--raw"))
4952                options->output_format |= DIFF_FORMAT_RAW;
4953        else if (!strcmp(arg, "--patch-with-raw")) {
4954                enable_patch_output(&options->output_format);
4955                options->output_format |= DIFF_FORMAT_RAW;
4956        } else if (!strcmp(arg, "--numstat"))
4957                options->output_format |= DIFF_FORMAT_NUMSTAT;
4958        else if (!strcmp(arg, "--shortstat"))
4959                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4960        else if (skip_prefix(arg, "-X", &arg) ||
4961                 skip_to_optional_arg(arg, "--dirstat", &arg))
4962                return parse_dirstat_opt(options, arg);
4963        else if (!strcmp(arg, "--cumulative"))
4964                return parse_dirstat_opt(options, "cumulative");
4965        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4966                parse_dirstat_opt(options, "files");
4967                return parse_dirstat_opt(options, arg);
4968        }
4969        else if (!strcmp(arg, "--check"))
4970                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4971        else if (!strcmp(arg, "--summary"))
4972                options->output_format |= DIFF_FORMAT_SUMMARY;
4973        else if (!strcmp(arg, "--patch-with-stat")) {
4974                enable_patch_output(&options->output_format);
4975                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4976        } else if (!strcmp(arg, "--name-only"))
4977                options->output_format |= DIFF_FORMAT_NAME;
4978        else if (!strcmp(arg, "--name-status"))
4979                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4980        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4981                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4982        else if (starts_with(arg, "--stat"))
4983                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4984                return stat_opt(options, av);
4985        else if (!strcmp(arg, "--compact-summary")) {
4986                 options->flags.stat_with_summary = 1;
4987                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4988        } else if (!strcmp(arg, "--no-compact-summary"))
4989                 options->flags.stat_with_summary = 0;
4990        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4991                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4992        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4993                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4994        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4995                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4996
4997        /* renames options */
4998        else if (starts_with(arg, "-B") ||
4999                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
5000                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
5001                        return error("invalid argument to -B: %s", arg+2);
5002        }
5003        else if (starts_with(arg, "-M") ||
5004                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
5005                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
5006                        return error("invalid argument to -M: %s", arg+2);
5007                options->detect_rename = DIFF_DETECT_RENAME;
5008        }
5009        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
5010                options->irreversible_delete = 1;
5011        }
5012        else if (starts_with(arg, "-C") ||
5013                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
5014                if (options->detect_rename == DIFF_DETECT_COPY)
5015                        options->flags.find_copies_harder = 1;
5016                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
5017                        return error("invalid argument to -C: %s", arg+2);
5018                options->detect_rename = DIFF_DETECT_COPY;
5019        }
5020        else if (!strcmp(arg, "--no-renames"))
5021                options->detect_rename = 0;
5022        else if (!strcmp(arg, "--rename-empty"))
5023                options->flags.rename_empty = 1;
5024        else if (!strcmp(arg, "--no-rename-empty"))
5025                options->flags.rename_empty = 0;
5026        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
5027                options->flags.relative_name = 1;
5028                if (arg)
5029                        options->prefix = arg;
5030        }
5031
5032        /* xdiff options */
5033        else if (!strcmp(arg, "--minimal"))
5034                DIFF_XDL_SET(options, NEED_MINIMAL);
5035        else if (!strcmp(arg, "--no-minimal"))
5036                DIFF_XDL_CLR(options, NEED_MINIMAL);
5037        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
5038                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
5039        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
5040                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
5041        else if (!strcmp(arg, "--ignore-space-at-eol"))
5042                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
5043        else if (!strcmp(arg, "--ignore-cr-at-eol"))
5044                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
5045        else if (!strcmp(arg, "--ignore-blank-lines"))
5046                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
5047        else if (!strcmp(arg, "--indent-heuristic"))
5048                DIFF_XDL_SET(options, INDENT_HEURISTIC);
5049        else if (!strcmp(arg, "--no-indent-heuristic"))
5050                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
5051        else if (!strcmp(arg, "--patience")) {
5052                int i;
5053                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5054                /*
5055                 * Both --patience and --anchored use PATIENCE_DIFF
5056                 * internally, so remove any anchors previously
5057                 * specified.
5058                 */
5059                for (i = 0; i < options->anchors_nr; i++)
5060                        free(options->anchors[i]);
5061                options->anchors_nr = 0;
5062        } else if (!strcmp(arg, "--histogram"))
5063                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
5064        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
5065                long value = parse_algorithm_value(optarg);
5066                if (value < 0)
5067                        return error("option diff-algorithm accepts \"myers\", "
5068                                     "\"minimal\", \"patience\" and \"histogram\"");
5069                /* clear out previous settings */
5070                DIFF_XDL_CLR(options, NEED_MINIMAL);
5071                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
5072                options->xdl_opts |= value;
5073                return argcount;
5074        } else if (skip_prefix(arg, "--anchored=", &arg)) {
5075                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5076                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
5077                           options->anchors_alloc);
5078                options->anchors[options->anchors_nr++] = xstrdup(arg);
5079        }
5080
5081        /* flags options */
5082        else if (!strcmp(arg, "--binary")) {
5083                enable_patch_output(&options->output_format);
5084                options->flags.binary = 1;
5085        }
5086        else if (!strcmp(arg, "--full-index"))
5087                options->flags.full_index = 1;
5088        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
5089                options->flags.text = 1;
5090        else if (!strcmp(arg, "-R"))
5091                options->flags.reverse_diff = 1;
5092        else if (!strcmp(arg, "--find-copies-harder"))
5093                options->flags.find_copies_harder = 1;
5094        else if (!strcmp(arg, "--follow"))
5095                options->flags.follow_renames = 1;
5096        else if (!strcmp(arg, "--no-follow")) {
5097                options->flags.follow_renames = 0;
5098                options->flags.default_follow_renames = 0;
5099        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5100                int value = git_config_colorbool(NULL, arg);
5101                if (value < 0)
5102                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5103                options->use_color = value;
5104        }
5105        else if (!strcmp(arg, "--no-color"))
5106                options->use_color = 0;
5107        else if (!strcmp(arg, "--color-moved")) {
5108                if (diff_color_moved_default)
5109                        options->color_moved = diff_color_moved_default;
5110                if (options->color_moved == COLOR_MOVED_NO)
5111                        options->color_moved = COLOR_MOVED_DEFAULT;
5112        } else if (!strcmp(arg, "--no-color-moved"))
5113                options->color_moved = COLOR_MOVED_NO;
5114        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5115                int cm = parse_color_moved(arg);
5116                if (cm < 0)
5117                        return error("bad --color-moved argument: %s", arg);
5118                options->color_moved = cm;
5119        } else if (!strcmp(arg, "--no-color-moved-ws")) {
5120                options->color_moved_ws_handling = 0;
5121        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5122                unsigned cm = parse_color_moved_ws(arg);
5123                if (cm & COLOR_MOVED_WS_ERROR)
5124                        return -1;
5125                options->color_moved_ws_handling = cm;
5126        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5127                options->use_color = 1;
5128                options->word_diff = DIFF_WORDS_COLOR;
5129        }
5130        else if (!strcmp(arg, "--word-diff")) {
5131                if (options->word_diff == DIFF_WORDS_NONE)
5132                        options->word_diff = DIFF_WORDS_PLAIN;
5133        }
5134        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5135                if (!strcmp(arg, "plain"))
5136                        options->word_diff = DIFF_WORDS_PLAIN;
5137                else if (!strcmp(arg, "color")) {
5138                        options->use_color = 1;
5139                        options->word_diff = DIFF_WORDS_COLOR;
5140                }
5141                else if (!strcmp(arg, "porcelain"))
5142                        options->word_diff = DIFF_WORDS_PORCELAIN;
5143                else if (!strcmp(arg, "none"))
5144                        options->word_diff = DIFF_WORDS_NONE;
5145                else
5146                        die("bad --word-diff argument: %s", arg);
5147        }
5148        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5149                if (options->word_diff == DIFF_WORDS_NONE)
5150                        options->word_diff = DIFF_WORDS_PLAIN;
5151                options->word_regex = optarg;
5152                return argcount;
5153        }
5154        else if (!strcmp(arg, "--exit-code"))
5155                options->flags.exit_with_status = 1;
5156        else if (!strcmp(arg, "--quiet"))
5157                options->flags.quick = 1;
5158        else if (!strcmp(arg, "--ext-diff"))
5159                options->flags.allow_external = 1;
5160        else if (!strcmp(arg, "--no-ext-diff"))
5161                options->flags.allow_external = 0;
5162        else if (!strcmp(arg, "--textconv")) {
5163                options->flags.allow_textconv = 1;
5164                options->flags.textconv_set_via_cmdline = 1;
5165        } else if (!strcmp(arg, "--no-textconv"))
5166                options->flags.allow_textconv = 0;
5167        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5168                options->flags.override_submodule_config = 1;
5169                handle_ignore_submodules_arg(options, arg);
5170        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5171                return parse_submodule_opt(options, arg);
5172        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5173                return parse_ws_error_highlight_opt(options, arg);
5174        else if (!strcmp(arg, "--ita-invisible-in-index"))
5175                options->ita_invisible_in_index = 1;
5176        else if (!strcmp(arg, "--ita-visible-in-index"))
5177                options->ita_invisible_in_index = 0;
5178
5179        /* misc options */
5180        else if (!strcmp(arg, "-z"))
5181                options->line_termination = 0;
5182        else if ((argcount = short_opt('l', av, &optarg))) {
5183                options->rename_limit = strtoul(optarg, NULL, 10);
5184                return argcount;
5185        }
5186        else if ((argcount = short_opt('S', av, &optarg))) {
5187                options->pickaxe = optarg;
5188                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5189                return argcount;
5190        } else if ((argcount = short_opt('G', av, &optarg))) {
5191                options->pickaxe = optarg;
5192                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5193                return argcount;
5194        }
5195        else if (!strcmp(arg, "--pickaxe-all"))
5196                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5197        else if (!strcmp(arg, "--pickaxe-regex"))
5198                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5199        else if ((argcount = short_opt('O', av, &optarg))) {
5200                options->orderfile = prefix_filename(prefix, optarg);
5201                return argcount;
5202        } else if (skip_prefix(arg, "--find-object=", &arg))
5203                return parse_objfind_opt(options, arg);
5204        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5205                int offending = parse_diff_filter_opt(optarg, options);
5206                if (offending)
5207                        die("unknown change class '%c' in --diff-filter=%s",
5208                            offending, optarg);
5209                return argcount;
5210        }
5211        else if (!strcmp(arg, "--no-abbrev"))
5212                options->abbrev = 0;
5213        else if (!strcmp(arg, "--abbrev"))
5214                options->abbrev = DEFAULT_ABBREV;
5215        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5216                options->abbrev = strtoul(arg, NULL, 10);
5217                if (options->abbrev < MINIMUM_ABBREV)
5218                        options->abbrev = MINIMUM_ABBREV;
5219                else if (the_hash_algo->hexsz < options->abbrev)
5220                        options->abbrev = the_hash_algo->hexsz;
5221        }
5222        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5223                options->a_prefix = optarg;
5224                return argcount;
5225        }
5226        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5227                options->line_prefix = optarg;
5228                options->line_prefix_length = strlen(options->line_prefix);
5229                graph_setup_line_prefix(options);
5230                return argcount;
5231        }
5232        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5233                options->b_prefix = optarg;
5234                return argcount;
5235        }
5236        else if (!strcmp(arg, "--no-prefix"))
5237                options->a_prefix = options->b_prefix = "";
5238        else if (opt_arg(arg, '\0', "inter-hunk-context",
5239                         &options->interhunkcontext))
5240                ;
5241        else if (!strcmp(arg, "-W"))
5242                options->flags.funccontext = 1;
5243        else if (!strcmp(arg, "--function-context"))
5244                options->flags.funccontext = 1;
5245        else if (!strcmp(arg, "--no-function-context"))
5246                options->flags.funccontext = 0;
5247        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5248                char *path = prefix_filename(prefix, optarg);
5249                options->file = xfopen(path, "w");
5250                options->close_file = 1;
5251                if (options->use_color != GIT_COLOR_ALWAYS)
5252                        options->use_color = GIT_COLOR_NEVER;
5253                free(path);
5254                return argcount;
5255        } else
5256                return 0;
5257        return 1;
5258}
5259
5260int parse_rename_score(const char **cp_p)
5261{
5262        unsigned long num, scale;
5263        int ch, dot;
5264        const char *cp = *cp_p;
5265
5266        num = 0;
5267        scale = 1;
5268        dot = 0;
5269        for (;;) {
5270                ch = *cp;
5271                if ( !dot && ch == '.' ) {
5272                        scale = 1;
5273                        dot = 1;
5274                } else if ( ch == '%' ) {
5275                        scale = dot ? scale*100 : 100;
5276                        cp++;   /* % is always at the end */
5277                        break;
5278                } else if ( ch >= '0' && ch <= '9' ) {
5279                        if ( scale < 100000 ) {
5280                                scale *= 10;
5281                                num = (num*10) + (ch-'0');
5282                        }
5283                } else {
5284                        break;
5285                }
5286                cp++;
5287        }
5288        *cp_p = cp;
5289
5290        /* user says num divided by scale and we say internally that
5291         * is MAX_SCORE * num / scale.
5292         */
5293        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5294}
5295
5296static int diff_scoreopt_parse(const char *opt)
5297{
5298        int opt1, opt2, cmd;
5299
5300        if (*opt++ != '-')
5301                return -1;
5302        cmd = *opt++;
5303        if (cmd == '-') {
5304                /* convert the long-form arguments into short-form versions */
5305                if (skip_prefix(opt, "break-rewrites", &opt)) {
5306                        if (*opt == 0 || *opt++ == '=')
5307                                cmd = 'B';
5308                } else if (skip_prefix(opt, "find-copies", &opt)) {
5309                        if (*opt == 0 || *opt++ == '=')
5310                                cmd = 'C';
5311                } else if (skip_prefix(opt, "find-renames", &opt)) {
5312                        if (*opt == 0 || *opt++ == '=')
5313                                cmd = 'M';
5314                }
5315        }
5316        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5317                return -1; /* that is not a -M, -C, or -B option */
5318
5319        opt1 = parse_rename_score(&opt);
5320        if (cmd != 'B')
5321                opt2 = 0;
5322        else {
5323                if (*opt == 0)
5324                        opt2 = 0;
5325                else if (*opt != '/')
5326                        return -1; /* we expect -B80/99 or -B80 */
5327                else {
5328                        opt++;
5329                        opt2 = parse_rename_score(&opt);
5330                }
5331        }
5332        if (*opt != 0)
5333                return -1;
5334        return opt1 | (opt2 << 16);
5335}
5336
5337struct diff_queue_struct diff_queued_diff;
5338
5339void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5340{
5341        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5342        queue->queue[queue->nr++] = dp;
5343}
5344
5345struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5346                                 struct diff_filespec *one,
5347                                 struct diff_filespec *two)
5348{
5349        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5350        dp->one = one;
5351        dp->two = two;
5352        if (queue)
5353                diff_q(queue, dp);
5354        return dp;
5355}
5356
5357void diff_free_filepair(struct diff_filepair *p)
5358{
5359        free_filespec(p->one);
5360        free_filespec(p->two);
5361        free(p);
5362}
5363
5364const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5365{
5366        int abblen;
5367        const char *abbrev;
5368
5369        /* Do we want all 40 hex characters? */
5370        if (len == the_hash_algo->hexsz)
5371                return oid_to_hex(oid);
5372
5373        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5374        abbrev = diff_abbrev_oid(oid, len);
5375
5376        if (!print_sha1_ellipsis())
5377                return abbrev;
5378
5379        abblen = strlen(abbrev);
5380
5381        /*
5382         * In well-behaved cases, where the abbreviated result is the
5383         * same as the requested length, append three dots after the
5384         * abbreviation (hence the whole logic is limited to the case
5385         * where abblen < 37); when the actual abbreviated result is a
5386         * bit longer than the requested length, we reduce the number
5387         * of dots so that they match the well-behaved ones.  However,
5388         * if the actual abbreviation is longer than the requested
5389         * length by more than three, we give up on aligning, and add
5390         * three dots anyway, to indicate that the output is not the
5391         * full object name.  Yes, this may be suboptimal, but this
5392         * appears only in "diff --raw --abbrev" output and it is not
5393         * worth the effort to change it now.  Note that this would
5394         * likely to work fine when the automatic sizing of default
5395         * abbreviation length is used--we would be fed -1 in "len" in
5396         * that case, and will end up always appending three-dots, but
5397         * the automatic sizing is supposed to give abblen that ensures
5398         * uniqueness across all objects (statistically speaking).
5399         */
5400        if (abblen < the_hash_algo->hexsz - 3) {
5401                static char hex[GIT_MAX_HEXSZ + 1];
5402                if (len < abblen && abblen <= len + 2)
5403                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5404                else
5405                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5406                return hex;
5407        }
5408
5409        return oid_to_hex(oid);
5410}
5411
5412static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5413{
5414        int line_termination = opt->line_termination;
5415        int inter_name_termination = line_termination ? '\t' : '\0';
5416
5417        fprintf(opt->file, "%s", diff_line_prefix(opt));
5418        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5419                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5420                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5421                fprintf(opt->file, "%s ",
5422                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5423        }
5424        if (p->score) {
5425                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5426                        inter_name_termination);
5427        } else {
5428                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5429        }
5430
5431        if (p->status == DIFF_STATUS_COPIED ||
5432            p->status == DIFF_STATUS_RENAMED) {
5433                const char *name_a, *name_b;
5434                name_a = p->one->path;
5435                name_b = p->two->path;
5436                strip_prefix(opt->prefix_length, &name_a, &name_b);
5437                write_name_quoted(name_a, opt->file, inter_name_termination);
5438                write_name_quoted(name_b, opt->file, line_termination);
5439        } else {
5440                const char *name_a, *name_b;
5441                name_a = p->one->mode ? p->one->path : p->two->path;
5442                name_b = NULL;
5443                strip_prefix(opt->prefix_length, &name_a, &name_b);
5444                write_name_quoted(name_a, opt->file, line_termination);
5445        }
5446}
5447
5448int diff_unmodified_pair(struct diff_filepair *p)
5449{
5450        /* This function is written stricter than necessary to support
5451         * the currently implemented transformers, but the idea is to
5452         * let transformers to produce diff_filepairs any way they want,
5453         * and filter and clean them up here before producing the output.
5454         */
5455        struct diff_filespec *one = p->one, *two = p->two;
5456
5457        if (DIFF_PAIR_UNMERGED(p))
5458                return 0; /* unmerged is interesting */
5459
5460        /* deletion, addition, mode or type change
5461         * and rename are all interesting.
5462         */
5463        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5464            DIFF_PAIR_MODE_CHANGED(p) ||
5465            strcmp(one->path, two->path))
5466                return 0;
5467
5468        /* both are valid and point at the same path.  that is, we are
5469         * dealing with a change.
5470         */
5471        if (one->oid_valid && two->oid_valid &&
5472            oideq(&one->oid, &two->oid) &&
5473            !one->dirty_submodule && !two->dirty_submodule)
5474                return 1; /* no change */
5475        if (!one->oid_valid && !two->oid_valid)
5476                return 1; /* both look at the same file on the filesystem. */
5477        return 0;
5478}
5479
5480static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5481{
5482        if (diff_unmodified_pair(p))
5483                return;
5484
5485        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5486            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5487                return; /* no tree diffs in patch format */
5488
5489        run_diff(p, o);
5490}
5491
5492static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5493                            struct diffstat_t *diffstat)
5494{
5495        if (diff_unmodified_pair(p))
5496                return;
5497
5498        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5499            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5500                return; /* no useful stat for tree diffs */
5501
5502        run_diffstat(p, o, diffstat);
5503}
5504
5505static void diff_flush_checkdiff(struct diff_filepair *p,
5506                struct diff_options *o)
5507{
5508        if (diff_unmodified_pair(p))
5509                return;
5510
5511        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5512            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5513                return; /* nothing to check in tree diffs */
5514
5515        run_checkdiff(p, o);
5516}
5517
5518int diff_queue_is_empty(void)
5519{
5520        struct diff_queue_struct *q = &diff_queued_diff;
5521        int i;
5522        for (i = 0; i < q->nr; i++)
5523                if (!diff_unmodified_pair(q->queue[i]))
5524                        return 0;
5525        return 1;
5526}
5527
5528#if DIFF_DEBUG
5529void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5530{
5531        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5532                x, one ? one : "",
5533                s->path,
5534                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5535                s->mode,
5536                s->oid_valid ? oid_to_hex(&s->oid) : "");
5537        fprintf(stderr, "queue[%d] %s size %lu\n",
5538                x, one ? one : "",
5539                s->size);
5540}
5541
5542void diff_debug_filepair(const struct diff_filepair *p, int i)
5543{
5544        diff_debug_filespec(p->one, i, "one");
5545        diff_debug_filespec(p->two, i, "two");
5546        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5547                p->score, p->status ? p->status : '?',
5548                p->one->rename_used, p->broken_pair);
5549}
5550
5551void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5552{
5553        int i;
5554        if (msg)
5555                fprintf(stderr, "%s\n", msg);
5556        fprintf(stderr, "q->nr = %d\n", q->nr);
5557        for (i = 0; i < q->nr; i++) {
5558                struct diff_filepair *p = q->queue[i];
5559                diff_debug_filepair(p, i);
5560        }
5561}
5562#endif
5563
5564static void diff_resolve_rename_copy(void)
5565{
5566        int i;
5567        struct diff_filepair *p;
5568        struct diff_queue_struct *q = &diff_queued_diff;
5569
5570        diff_debug_queue("resolve-rename-copy", q);
5571
5572        for (i = 0; i < q->nr; i++) {
5573                p = q->queue[i];
5574                p->status = 0; /* undecided */
5575                if (DIFF_PAIR_UNMERGED(p))
5576                        p->status = DIFF_STATUS_UNMERGED;
5577                else if (!DIFF_FILE_VALID(p->one))
5578                        p->status = DIFF_STATUS_ADDED;
5579                else if (!DIFF_FILE_VALID(p->two))
5580                        p->status = DIFF_STATUS_DELETED;
5581                else if (DIFF_PAIR_TYPE_CHANGED(p))
5582                        p->status = DIFF_STATUS_TYPE_CHANGED;
5583
5584                /* from this point on, we are dealing with a pair
5585                 * whose both sides are valid and of the same type, i.e.
5586                 * either in-place edit or rename/copy edit.
5587                 */
5588                else if (DIFF_PAIR_RENAME(p)) {
5589                        /*
5590                         * A rename might have re-connected a broken
5591                         * pair up, causing the pathnames to be the
5592                         * same again. If so, that's not a rename at
5593                         * all, just a modification..
5594                         *
5595                         * Otherwise, see if this source was used for
5596                         * multiple renames, in which case we decrement
5597                         * the count, and call it a copy.
5598                         */
5599                        if (!strcmp(p->one->path, p->two->path))
5600                                p->status = DIFF_STATUS_MODIFIED;
5601                        else if (--p->one->rename_used > 0)
5602                                p->status = DIFF_STATUS_COPIED;
5603                        else
5604                                p->status = DIFF_STATUS_RENAMED;
5605                }
5606                else if (!oideq(&p->one->oid, &p->two->oid) ||
5607                         p->one->mode != p->two->mode ||
5608                         p->one->dirty_submodule ||
5609                         p->two->dirty_submodule ||
5610                         is_null_oid(&p->one->oid))
5611                        p->status = DIFF_STATUS_MODIFIED;
5612                else {
5613                        /* This is a "no-change" entry and should not
5614                         * happen anymore, but prepare for broken callers.
5615                         */
5616                        error("feeding unmodified %s to diffcore",
5617                              p->one->path);
5618                        p->status = DIFF_STATUS_UNKNOWN;
5619                }
5620        }
5621        diff_debug_queue("resolve-rename-copy done", q);
5622}
5623
5624static int check_pair_status(struct diff_filepair *p)
5625{
5626        switch (p->status) {
5627        case DIFF_STATUS_UNKNOWN:
5628                return 0;
5629        case 0:
5630                die("internal error in diff-resolve-rename-copy");
5631        default:
5632                return 1;
5633        }
5634}
5635
5636static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5637{
5638        int fmt = opt->output_format;
5639
5640        if (fmt & DIFF_FORMAT_CHECKDIFF)
5641                diff_flush_checkdiff(p, opt);
5642        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5643                diff_flush_raw(p, opt);
5644        else if (fmt & DIFF_FORMAT_NAME) {
5645                const char *name_a, *name_b;
5646                name_a = p->two->path;
5647                name_b = NULL;
5648                strip_prefix(opt->prefix_length, &name_a, &name_b);
5649                fprintf(opt->file, "%s", diff_line_prefix(opt));
5650                write_name_quoted(name_a, opt->file, opt->line_termination);
5651        }
5652}
5653
5654static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5655{
5656        struct strbuf sb = STRBUF_INIT;
5657        if (fs->mode)
5658                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5659        else
5660                strbuf_addf(&sb, " %s ", newdelete);
5661
5662        quote_c_style(fs->path, &sb, NULL, 0);
5663        strbuf_addch(&sb, '\n');
5664        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5665                         sb.buf, sb.len, 0);
5666        strbuf_release(&sb);
5667}
5668
5669static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5670                int show_name)
5671{
5672        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5673                struct strbuf sb = STRBUF_INIT;
5674                strbuf_addf(&sb, " mode change %06o => %06o",
5675                            p->one->mode, p->two->mode);
5676                if (show_name) {
5677                        strbuf_addch(&sb, ' ');
5678                        quote_c_style(p->two->path, &sb, NULL, 0);
5679                }
5680                strbuf_addch(&sb, '\n');
5681                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5682                                 sb.buf, sb.len, 0);
5683                strbuf_release(&sb);
5684        }
5685}
5686
5687static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5688                struct diff_filepair *p)
5689{
5690        struct strbuf sb = STRBUF_INIT;
5691        struct strbuf names = STRBUF_INIT;
5692
5693        pprint_rename(&names, p->one->path, p->two->path);
5694        strbuf_addf(&sb, " %s %s (%d%%)\n",
5695                    renamecopy, names.buf, similarity_index(p));
5696        strbuf_release(&names);
5697        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5698                                 sb.buf, sb.len, 0);
5699        show_mode_change(opt, p, 0);
5700        strbuf_release(&sb);
5701}
5702
5703static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5704{
5705        switch(p->status) {
5706        case DIFF_STATUS_DELETED:
5707                show_file_mode_name(opt, "delete", p->one);
5708                break;
5709        case DIFF_STATUS_ADDED:
5710                show_file_mode_name(opt, "create", p->two);
5711                break;
5712        case DIFF_STATUS_COPIED:
5713                show_rename_copy(opt, "copy", p);
5714                break;
5715        case DIFF_STATUS_RENAMED:
5716                show_rename_copy(opt, "rename", p);
5717                break;
5718        default:
5719                if (p->score) {
5720                        struct strbuf sb = STRBUF_INIT;
5721                        strbuf_addstr(&sb, " rewrite ");
5722                        quote_c_style(p->two->path, &sb, NULL, 0);
5723                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5724                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5725                                         sb.buf, sb.len, 0);
5726                        strbuf_release(&sb);
5727                }
5728                show_mode_change(opt, p, !p->score);
5729                break;
5730        }
5731}
5732
5733struct patch_id_t {
5734        git_SHA_CTX *ctx;
5735        int patchlen;
5736};
5737
5738static int remove_space(char *line, int len)
5739{
5740        int i;
5741        char *dst = line;
5742        unsigned char c;
5743
5744        for (i = 0; i < len; i++)
5745                if (!isspace((c = line[i])))
5746                        *dst++ = c;
5747
5748        return dst - line;
5749}
5750
5751static void patch_id_consume(void *priv, char *line, unsigned long len)
5752{
5753        struct patch_id_t *data = priv;
5754        int new_len;
5755
5756        new_len = remove_space(line, len);
5757
5758        git_SHA1_Update(data->ctx, line, new_len);
5759        data->patchlen += new_len;
5760}
5761
5762static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5763{
5764        git_SHA1_Update(ctx, str, strlen(str));
5765}
5766
5767static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5768{
5769        /* large enough for 2^32 in octal */
5770        char buf[12];
5771        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5772        git_SHA1_Update(ctx, buf, len);
5773}
5774
5775/* returns 0 upon success, and writes result into sha1 */
5776static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5777{
5778        struct diff_queue_struct *q = &diff_queued_diff;
5779        int i;
5780        git_SHA_CTX ctx;
5781        struct patch_id_t data;
5782
5783        git_SHA1_Init(&ctx);
5784        memset(&data, 0, sizeof(struct patch_id_t));
5785        data.ctx = &ctx;
5786
5787        for (i = 0; i < q->nr; i++) {
5788                xpparam_t xpp;
5789                xdemitconf_t xecfg;
5790                mmfile_t mf1, mf2;
5791                struct diff_filepair *p = q->queue[i];
5792                int len1, len2;
5793
5794                memset(&xpp, 0, sizeof(xpp));
5795                memset(&xecfg, 0, sizeof(xecfg));
5796                if (p->status == 0)
5797                        return error("internal diff status error");
5798                if (p->status == DIFF_STATUS_UNKNOWN)
5799                        continue;
5800                if (diff_unmodified_pair(p))
5801                        continue;
5802                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5803                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5804                        continue;
5805                if (DIFF_PAIR_UNMERGED(p))
5806                        continue;
5807
5808                diff_fill_oid_info(p->one, options->repo->index);
5809                diff_fill_oid_info(p->two, options->repo->index);
5810
5811                len1 = remove_space(p->one->path, strlen(p->one->path));
5812                len2 = remove_space(p->two->path, strlen(p->two->path));
5813                patch_id_add_string(&ctx, "diff--git");
5814                patch_id_add_string(&ctx, "a/");
5815                git_SHA1_Update(&ctx, p->one->path, len1);
5816                patch_id_add_string(&ctx, "b/");
5817                git_SHA1_Update(&ctx, p->two->path, len2);
5818
5819                if (p->one->mode == 0) {
5820                        patch_id_add_string(&ctx, "newfilemode");
5821                        patch_id_add_mode(&ctx, p->two->mode);
5822                        patch_id_add_string(&ctx, "---/dev/null");
5823                        patch_id_add_string(&ctx, "+++b/");
5824                        git_SHA1_Update(&ctx, p->two->path, len2);
5825                } else if (p->two->mode == 0) {
5826                        patch_id_add_string(&ctx, "deletedfilemode");
5827                        patch_id_add_mode(&ctx, p->one->mode);
5828                        patch_id_add_string(&ctx, "---a/");
5829                        git_SHA1_Update(&ctx, p->one->path, len1);
5830                        patch_id_add_string(&ctx, "+++/dev/null");
5831                } else {
5832                        patch_id_add_string(&ctx, "---a/");
5833                        git_SHA1_Update(&ctx, p->one->path, len1);
5834                        patch_id_add_string(&ctx, "+++b/");
5835                        git_SHA1_Update(&ctx, p->two->path, len2);
5836                }
5837
5838                if (diff_header_only)
5839                        continue;
5840
5841                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5842                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5843                        return error("unable to read files to diff");
5844
5845                if (diff_filespec_is_binary(options->repo, p->one) ||
5846                    diff_filespec_is_binary(options->repo, p->two)) {
5847                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5848                                        GIT_SHA1_HEXSZ);
5849                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5850                                        GIT_SHA1_HEXSZ);
5851                        continue;
5852                }
5853
5854                xpp.flags = 0;
5855                xecfg.ctxlen = 3;
5856                xecfg.flags = 0;
5857                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
5858                                  patch_id_consume, &data, &xpp, &xecfg))
5859                        return error("unable to generate patch-id diff for %s",
5860                                     p->one->path);
5861        }
5862
5863        git_SHA1_Final(oid->hash, &ctx);
5864        return 0;
5865}
5866
5867int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5868{
5869        struct diff_queue_struct *q = &diff_queued_diff;
5870        int i;
5871        int result = diff_get_patch_id(options, oid, diff_header_only);
5872
5873        for (i = 0; i < q->nr; i++)
5874                diff_free_filepair(q->queue[i]);
5875
5876        free(q->queue);
5877        DIFF_QUEUE_CLEAR(q);
5878
5879        return result;
5880}
5881
5882static int is_summary_empty(const struct diff_queue_struct *q)
5883{
5884        int i;
5885
5886        for (i = 0; i < q->nr; i++) {
5887                const struct diff_filepair *p = q->queue[i];
5888
5889                switch (p->status) {
5890                case DIFF_STATUS_DELETED:
5891                case DIFF_STATUS_ADDED:
5892                case DIFF_STATUS_COPIED:
5893                case DIFF_STATUS_RENAMED:
5894                        return 0;
5895                default:
5896                        if (p->score)
5897                                return 0;
5898                        if (p->one->mode && p->two->mode &&
5899                            p->one->mode != p->two->mode)
5900                                return 0;
5901                        break;
5902                }
5903        }
5904        return 1;
5905}
5906
5907static const char rename_limit_warning[] =
5908N_("inexact rename detection was skipped due to too many files.");
5909
5910static const char degrade_cc_to_c_warning[] =
5911N_("only found copies from modified paths due to too many files.");
5912
5913static const char rename_limit_advice[] =
5914N_("you may want to set your %s variable to at least "
5915   "%d and retry the command.");
5916
5917void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5918{
5919        fflush(stdout);
5920        if (degraded_cc)
5921                warning(_(degrade_cc_to_c_warning));
5922        else if (needed)
5923                warning(_(rename_limit_warning));
5924        else
5925                return;
5926        if (0 < needed)
5927                warning(_(rename_limit_advice), varname, needed);
5928}
5929
5930static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5931{
5932        int i;
5933        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5934        struct diff_queue_struct *q = &diff_queued_diff;
5935
5936        if (WSEH_NEW & WS_RULE_MASK)
5937                BUG("WS rules bit mask overlaps with diff symbol flags");
5938
5939        if (o->color_moved)
5940                o->emitted_symbols = &esm;
5941
5942        for (i = 0; i < q->nr; i++) {
5943                struct diff_filepair *p = q->queue[i];
5944                if (check_pair_status(p))
5945                        diff_flush_patch(p, o);
5946        }
5947
5948        if (o->emitted_symbols) {
5949                if (o->color_moved) {
5950                        struct hashmap add_lines, del_lines;
5951
5952                        if (o->color_moved_ws_handling &
5953                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5954                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5955
5956                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5957                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5958
5959                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5960                        mark_color_as_moved(o, &add_lines, &del_lines);
5961                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5962                                dim_moved_lines(o);
5963
5964                        hashmap_free(&add_lines, 1);
5965                        hashmap_free(&del_lines, 1);
5966                }
5967
5968                for (i = 0; i < esm.nr; i++)
5969                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5970
5971                for (i = 0; i < esm.nr; i++)
5972                        free((void *)esm.buf[i].line);
5973                esm.nr = 0;
5974
5975                o->emitted_symbols = NULL;
5976        }
5977}
5978
5979void diff_flush(struct diff_options *options)
5980{
5981        struct diff_queue_struct *q = &diff_queued_diff;
5982        int i, output_format = options->output_format;
5983        int separator = 0;
5984        int dirstat_by_line = 0;
5985
5986        /*
5987         * Order: raw, stat, summary, patch
5988         * or:    name/name-status/checkdiff (other bits clear)
5989         */
5990        if (!q->nr)
5991                goto free_queue;
5992
5993        if (output_format & (DIFF_FORMAT_RAW |
5994                             DIFF_FORMAT_NAME |
5995                             DIFF_FORMAT_NAME_STATUS |
5996                             DIFF_FORMAT_CHECKDIFF)) {
5997                for (i = 0; i < q->nr; i++) {
5998                        struct diff_filepair *p = q->queue[i];
5999                        if (check_pair_status(p))
6000                                flush_one_pair(p, options);
6001                }
6002                separator++;
6003        }
6004
6005        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
6006                dirstat_by_line = 1;
6007
6008        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
6009            dirstat_by_line) {
6010                struct diffstat_t diffstat;
6011
6012                memset(&diffstat, 0, sizeof(struct diffstat_t));
6013                for (i = 0; i < q->nr; i++) {
6014                        struct diff_filepair *p = q->queue[i];
6015                        if (check_pair_status(p))
6016                                diff_flush_stat(p, options, &diffstat);
6017                }
6018                if (output_format & DIFF_FORMAT_NUMSTAT)
6019                        show_numstat(&diffstat, options);
6020                if (output_format & DIFF_FORMAT_DIFFSTAT)
6021                        show_stats(&diffstat, options);
6022                if (output_format & DIFF_FORMAT_SHORTSTAT)
6023                        show_shortstats(&diffstat, options);
6024                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
6025                        show_dirstat_by_line(&diffstat, options);
6026                free_diffstat_info(&diffstat);
6027                separator++;
6028        }
6029        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
6030                show_dirstat(options);
6031
6032        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
6033                for (i = 0; i < q->nr; i++) {
6034                        diff_summary(options, q->queue[i]);
6035                }
6036                separator++;
6037        }
6038
6039        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
6040            options->flags.exit_with_status &&
6041            options->flags.diff_from_contents) {
6042                /*
6043                 * run diff_flush_patch for the exit status. setting
6044                 * options->file to /dev/null should be safe, because we
6045                 * aren't supposed to produce any output anyway.
6046                 */
6047                if (options->close_file)
6048                        fclose(options->file);
6049                options->file = xfopen("/dev/null", "w");
6050                options->close_file = 1;
6051                options->color_moved = 0;
6052                for (i = 0; i < q->nr; i++) {
6053                        struct diff_filepair *p = q->queue[i];
6054                        if (check_pair_status(p))
6055                                diff_flush_patch(p, options);
6056                        if (options->found_changes)
6057                                break;
6058                }
6059        }
6060
6061        if (output_format & DIFF_FORMAT_PATCH) {
6062                if (separator) {
6063                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
6064                        if (options->stat_sep)
6065                                /* attach patch instead of inline */
6066                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
6067                                                 NULL, 0, 0);
6068                }
6069
6070                diff_flush_patch_all_file_pairs(options);
6071        }
6072
6073        if (output_format & DIFF_FORMAT_CALLBACK)
6074                options->format_callback(q, options, options->format_callback_data);
6075
6076        for (i = 0; i < q->nr; i++)
6077                diff_free_filepair(q->queue[i]);
6078free_queue:
6079        free(q->queue);
6080        DIFF_QUEUE_CLEAR(q);
6081        if (options->close_file)
6082                fclose(options->file);
6083
6084        /*
6085         * Report the content-level differences with HAS_CHANGES;
6086         * diff_addremove/diff_change does not set the bit when
6087         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6088         */
6089        if (options->flags.diff_from_contents) {
6090                if (options->found_changes)
6091                        options->flags.has_changes = 1;
6092                else
6093                        options->flags.has_changes = 0;
6094        }
6095}
6096
6097static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6098{
6099        return (((p->status == DIFF_STATUS_MODIFIED) &&
6100                 ((p->score &&
6101                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6102                  (!p->score &&
6103                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6104                ((p->status != DIFF_STATUS_MODIFIED) &&
6105                 filter_bit_tst(p->status, options)));
6106}
6107
6108static void diffcore_apply_filter(struct diff_options *options)
6109{
6110        int i;
6111        struct diff_queue_struct *q = &diff_queued_diff;
6112        struct diff_queue_struct outq;
6113
6114        DIFF_QUEUE_CLEAR(&outq);
6115
6116        if (!options->filter)
6117                return;
6118
6119        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6120                int found;
6121                for (i = found = 0; !found && i < q->nr; i++) {
6122                        if (match_filter(options, q->queue[i]))
6123                                found++;
6124                }
6125                if (found)
6126                        return;
6127
6128                /* otherwise we will clear the whole queue
6129                 * by copying the empty outq at the end of this
6130                 * function, but first clear the current entries
6131                 * in the queue.
6132                 */
6133                for (i = 0; i < q->nr; i++)
6134                        diff_free_filepair(q->queue[i]);
6135        }
6136        else {
6137                /* Only the matching ones */
6138                for (i = 0; i < q->nr; i++) {
6139                        struct diff_filepair *p = q->queue[i];
6140                        if (match_filter(options, p))
6141                                diff_q(&outq, p);
6142                        else
6143                                diff_free_filepair(p);
6144                }
6145        }
6146        free(q->queue);
6147        *q = outq;
6148}
6149
6150/* Check whether two filespecs with the same mode and size are identical */
6151static int diff_filespec_is_identical(struct repository *r,
6152                                      struct diff_filespec *one,
6153                                      struct diff_filespec *two)
6154{
6155        if (S_ISGITLINK(one->mode))
6156                return 0;
6157        if (diff_populate_filespec(r, one, 0))
6158                return 0;
6159        if (diff_populate_filespec(r, two, 0))
6160                return 0;
6161        return !memcmp(one->data, two->data, one->size);
6162}
6163
6164static int diff_filespec_check_stat_unmatch(struct repository *r,
6165                                            struct diff_filepair *p)
6166{
6167        if (p->done_skip_stat_unmatch)
6168                return p->skip_stat_unmatch_result;
6169
6170        p->done_skip_stat_unmatch = 1;
6171        p->skip_stat_unmatch_result = 0;
6172        /*
6173         * 1. Entries that come from stat info dirtiness
6174         *    always have both sides (iow, not create/delete),
6175         *    one side of the object name is unknown, with
6176         *    the same mode and size.  Keep the ones that
6177         *    do not match these criteria.  They have real
6178         *    differences.
6179         *
6180         * 2. At this point, the file is known to be modified,
6181         *    with the same mode and size, and the object
6182         *    name of one side is unknown.  Need to inspect
6183         *    the identical contents.
6184         */
6185        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6186            !DIFF_FILE_VALID(p->two) ||
6187            (p->one->oid_valid && p->two->oid_valid) ||
6188            (p->one->mode != p->two->mode) ||
6189            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6190            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6191            (p->one->size != p->two->size) ||
6192            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6193                p->skip_stat_unmatch_result = 1;
6194        return p->skip_stat_unmatch_result;
6195}
6196
6197static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6198{
6199        int i;
6200        struct diff_queue_struct *q = &diff_queued_diff;
6201        struct diff_queue_struct outq;
6202        DIFF_QUEUE_CLEAR(&outq);
6203
6204        for (i = 0; i < q->nr; i++) {
6205                struct diff_filepair *p = q->queue[i];
6206
6207                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6208                        diff_q(&outq, p);
6209                else {
6210                        /*
6211                         * The caller can subtract 1 from skip_stat_unmatch
6212                         * to determine how many paths were dirty only
6213                         * due to stat info mismatch.
6214                         */
6215                        if (!diffopt->flags.no_index)
6216                                diffopt->skip_stat_unmatch++;
6217                        diff_free_filepair(p);
6218                }
6219        }
6220        free(q->queue);
6221        *q = outq;
6222}
6223
6224static int diffnamecmp(const void *a_, const void *b_)
6225{
6226        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6227        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6228        const char *name_a, *name_b;
6229
6230        name_a = a->one ? a->one->path : a->two->path;
6231        name_b = b->one ? b->one->path : b->two->path;
6232        return strcmp(name_a, name_b);
6233}
6234
6235void diffcore_fix_diff_index(struct diff_options *options)
6236{
6237        struct diff_queue_struct *q = &diff_queued_diff;
6238        QSORT(q->queue, q->nr, diffnamecmp);
6239}
6240
6241void diffcore_std(struct diff_options *options)
6242{
6243        /* NOTE please keep the following in sync with diff_tree_combined() */
6244        if (options->skip_stat_unmatch)
6245                diffcore_skip_stat_unmatch(options);
6246        if (!options->found_follow) {
6247                /* See try_to_follow_renames() in tree-diff.c */
6248                if (options->break_opt != -1)
6249                        diffcore_break(options->repo,
6250                                       options->break_opt);
6251                if (options->detect_rename)
6252                        diffcore_rename(options);
6253                if (options->break_opt != -1)
6254                        diffcore_merge_broken();
6255        }
6256        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6257                diffcore_pickaxe(options);
6258        if (options->orderfile)
6259                diffcore_order(options->orderfile);
6260        if (!options->found_follow)
6261                /* See try_to_follow_renames() in tree-diff.c */
6262                diff_resolve_rename_copy();
6263        diffcore_apply_filter(options);
6264
6265        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6266                options->flags.has_changes = 1;
6267        else
6268                options->flags.has_changes = 0;
6269
6270        options->found_follow = 0;
6271}
6272
6273int diff_result_code(struct diff_options *opt, int status)
6274{
6275        int result = 0;
6276
6277        diff_warn_rename_limit("diff.renameLimit",
6278                               opt->needed_rename_limit,
6279                               opt->degraded_cc_to_c);
6280        if (!opt->flags.exit_with_status &&
6281            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6282                return status;
6283        if (opt->flags.exit_with_status &&
6284            opt->flags.has_changes)
6285                result |= 01;
6286        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6287            opt->flags.check_failed)
6288                result |= 02;
6289        return result;
6290}
6291
6292int diff_can_quit_early(struct diff_options *opt)
6293{
6294        return (opt->flags.quick &&
6295                !opt->filter &&
6296                opt->flags.has_changes);
6297}
6298
6299/*
6300 * Shall changes to this submodule be ignored?
6301 *
6302 * Submodule changes can be configured to be ignored separately for each path,
6303 * but that configuration can be overridden from the command line.
6304 */
6305static int is_submodule_ignored(const char *path, struct diff_options *options)
6306{
6307        int ignored = 0;
6308        struct diff_flags orig_flags = options->flags;
6309        if (!options->flags.override_submodule_config)
6310                set_diffopt_flags_from_submodule_config(options, path);
6311        if (options->flags.ignore_submodules)
6312                ignored = 1;
6313        options->flags = orig_flags;
6314        return ignored;
6315}
6316
6317void diff_addremove(struct diff_options *options,
6318                    int addremove, unsigned mode,
6319                    const struct object_id *oid,
6320                    int oid_valid,
6321                    const char *concatpath, unsigned dirty_submodule)
6322{
6323        struct diff_filespec *one, *two;
6324
6325        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6326                return;
6327
6328        /* This may look odd, but it is a preparation for
6329         * feeding "there are unchanged files which should
6330         * not produce diffs, but when you are doing copy
6331         * detection you would need them, so here they are"
6332         * entries to the diff-core.  They will be prefixed
6333         * with something like '=' or '*' (I haven't decided
6334         * which but should not make any difference).
6335         * Feeding the same new and old to diff_change()
6336         * also has the same effect.
6337         * Before the final output happens, they are pruned after
6338         * merged into rename/copy pairs as appropriate.
6339         */
6340        if (options->flags.reverse_diff)
6341                addremove = (addremove == '+' ? '-' :
6342                             addremove == '-' ? '+' : addremove);
6343
6344        if (options->prefix &&
6345            strncmp(concatpath, options->prefix, options->prefix_length))
6346                return;
6347
6348        one = alloc_filespec(concatpath);
6349        two = alloc_filespec(concatpath);
6350
6351        if (addremove != '+')
6352                fill_filespec(one, oid, oid_valid, mode);
6353        if (addremove != '-') {
6354                fill_filespec(two, oid, oid_valid, mode);
6355                two->dirty_submodule = dirty_submodule;
6356        }
6357
6358        diff_queue(&diff_queued_diff, one, two);
6359        if (!options->flags.diff_from_contents)
6360                options->flags.has_changes = 1;
6361}
6362
6363void diff_change(struct diff_options *options,
6364                 unsigned old_mode, unsigned new_mode,
6365                 const struct object_id *old_oid,
6366                 const struct object_id *new_oid,
6367                 int old_oid_valid, int new_oid_valid,
6368                 const char *concatpath,
6369                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6370{
6371        struct diff_filespec *one, *two;
6372        struct diff_filepair *p;
6373
6374        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6375            is_submodule_ignored(concatpath, options))
6376                return;
6377
6378        if (options->flags.reverse_diff) {
6379                SWAP(old_mode, new_mode);
6380                SWAP(old_oid, new_oid);
6381                SWAP(old_oid_valid, new_oid_valid);
6382                SWAP(old_dirty_submodule, new_dirty_submodule);
6383        }
6384
6385        if (options->prefix &&
6386            strncmp(concatpath, options->prefix, options->prefix_length))
6387                return;
6388
6389        one = alloc_filespec(concatpath);
6390        two = alloc_filespec(concatpath);
6391        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6392        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6393        one->dirty_submodule = old_dirty_submodule;
6394        two->dirty_submodule = new_dirty_submodule;
6395        p = diff_queue(&diff_queued_diff, one, two);
6396
6397        if (options->flags.diff_from_contents)
6398                return;
6399
6400        if (options->flags.quick && options->skip_stat_unmatch &&
6401            !diff_filespec_check_stat_unmatch(options->repo, p))
6402                return;
6403
6404        options->flags.has_changes = 1;
6405}
6406
6407struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6408{
6409        struct diff_filepair *pair;
6410        struct diff_filespec *one, *two;
6411
6412        if (options->prefix &&
6413            strncmp(path, options->prefix, options->prefix_length))
6414                return NULL;
6415
6416        one = alloc_filespec(path);
6417        two = alloc_filespec(path);
6418        pair = diff_queue(&diff_queued_diff, one, two);
6419        pair->is_unmerged = 1;
6420        return pair;
6421}
6422
6423static char *run_textconv(struct repository *r,
6424                          const char *pgm,
6425                          struct diff_filespec *spec,
6426                          size_t *outsize)
6427{
6428        struct diff_tempfile *temp;
6429        const char *argv[3];
6430        const char **arg = argv;
6431        struct child_process child = CHILD_PROCESS_INIT;
6432        struct strbuf buf = STRBUF_INIT;
6433        int err = 0;
6434
6435        temp = prepare_temp_file(r, spec->path, spec);
6436        *arg++ = pgm;
6437        *arg++ = temp->name;
6438        *arg = NULL;
6439
6440        child.use_shell = 1;
6441        child.argv = argv;
6442        child.out = -1;
6443        if (start_command(&child)) {
6444                remove_tempfile();
6445                return NULL;
6446        }
6447
6448        if (strbuf_read(&buf, child.out, 0) < 0)
6449                err = error("error reading from textconv command '%s'", pgm);
6450        close(child.out);
6451
6452        if (finish_command(&child) || err) {
6453                strbuf_release(&buf);
6454                remove_tempfile();
6455                return NULL;
6456        }
6457        remove_tempfile();
6458
6459        return strbuf_detach(&buf, outsize);
6460}
6461
6462size_t fill_textconv(struct repository *r,
6463                     struct userdiff_driver *driver,
6464                     struct diff_filespec *df,
6465                     char **outbuf)
6466{
6467        size_t size;
6468
6469        if (!driver) {
6470                if (!DIFF_FILE_VALID(df)) {
6471                        *outbuf = "";
6472                        return 0;
6473                }
6474                if (diff_populate_filespec(r, df, 0))
6475                        die("unable to read files to diff");
6476                *outbuf = df->data;
6477                return df->size;
6478        }
6479
6480        if (!driver->textconv)
6481                BUG("fill_textconv called with non-textconv driver");
6482
6483        if (driver->textconv_cache && df->oid_valid) {
6484                *outbuf = notes_cache_get(driver->textconv_cache,
6485                                          &df->oid,
6486                                          &size);
6487                if (*outbuf)
6488                        return size;
6489        }
6490
6491        *outbuf = run_textconv(r, driver->textconv, df, &size);
6492        if (!*outbuf)
6493                die("unable to read files to diff");
6494
6495        if (driver->textconv_cache && df->oid_valid) {
6496                /* ignore errors, as we might be in a readonly repository */
6497                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6498                                size);
6499                /*
6500                 * we could save up changes and flush them all at the end,
6501                 * but we would need an extra call after all diffing is done.
6502                 * Since generating a cache entry is the slow path anyway,
6503                 * this extra overhead probably isn't a big deal.
6504                 */
6505                notes_cache_write(driver->textconv_cache);
6506        }
6507
6508        return size;
6509}
6510
6511int textconv_object(struct repository *r,
6512                    const char *path,
6513                    unsigned mode,
6514                    const struct object_id *oid,
6515                    int oid_valid,
6516                    char **buf,
6517                    unsigned long *buf_size)
6518{
6519        struct diff_filespec *df;
6520        struct userdiff_driver *textconv;
6521
6522        df = alloc_filespec(path);
6523        fill_filespec(df, oid, oid_valid, mode);
6524        textconv = get_textconv(r, df);
6525        if (!textconv) {
6526                free_filespec(df);
6527                return 0;
6528        }
6529
6530        *buf_size = fill_textconv(r, textconv, df, buf);
6531        free_filespec(df);
6532        return 1;
6533}
6534
6535void setup_diff_pager(struct diff_options *opt)
6536{
6537        /*
6538         * If the user asked for our exit code, then either they want --quiet
6539         * or --exit-code. We should definitely not bother with a pager in the
6540         * former case, as we will generate no output. Since we still properly
6541         * report our exit code even when a pager is run, we _could_ run a
6542         * pager with --exit-code. But since we have not done so historically,
6543         * and because it is easy to find people oneline advising "git diff
6544         * --exit-code" in hooks and other scripts, we do not do so.
6545         */
6546        if (!opt->flags.exit_with_status &&
6547            check_pager_config("diff") != 0)
6548                setup_pager();
6549}