a74e6e06dfb6dba3af802a1c747e23d2b7e0f8fd
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "tempfile.h"
   6#include "quote.h"
   7#include "diff.h"
   8#include "diffcore.h"
   9#include "delta.h"
  10#include "xdiff-interface.h"
  11#include "color.h"
  12#include "attr.h"
  13#include "run-command.h"
  14#include "utf8.h"
  15#include "userdiff.h"
  16#include "submodule-config.h"
  17#include "submodule.h"
  18#include "ll-merge.h"
  19#include "string-list.h"
  20#include "argv-array.h"
  21#include "graph.h"
  22
  23#ifdef NO_FAST_WORKING_DIRECTORY
  24#define FAST_WORKING_DIRECTORY 0
  25#else
  26#define FAST_WORKING_DIRECTORY 1
  27#endif
  28
  29static int diff_detect_rename_default;
  30static int diff_compaction_heuristic; /* experimental */
  31static int diff_rename_limit_default = 400;
  32static int diff_suppress_blank_empty;
  33static int diff_use_color_default = -1;
  34static int diff_context_default = 3;
  35static const char *diff_word_regex_cfg;
  36static const char *external_diff_cmd_cfg;
  37static const char *diff_order_file_cfg;
  38int diff_auto_refresh_index = 1;
  39static int diff_mnemonic_prefix;
  40static int diff_no_prefix;
  41static int diff_stat_graph_width;
  42static int diff_dirstat_permille_default = 30;
  43static struct diff_options default_diff_options;
  44static long diff_algorithm;
  45
  46static char diff_colors[][COLOR_MAXLEN] = {
  47        GIT_COLOR_RESET,
  48        GIT_COLOR_NORMAL,       /* CONTEXT */
  49        GIT_COLOR_BOLD,         /* METAINFO */
  50        GIT_COLOR_CYAN,         /* FRAGINFO */
  51        GIT_COLOR_RED,          /* OLD */
  52        GIT_COLOR_GREEN,        /* NEW */
  53        GIT_COLOR_YELLOW,       /* COMMIT */
  54        GIT_COLOR_BG_RED,       /* WHITESPACE */
  55        GIT_COLOR_NORMAL,       /* FUNCINFO */
  56};
  57
  58static int parse_diff_color_slot(const char *var)
  59{
  60        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  61                return DIFF_CONTEXT;
  62        if (!strcasecmp(var, "meta"))
  63                return DIFF_METAINFO;
  64        if (!strcasecmp(var, "frag"))
  65                return DIFF_FRAGINFO;
  66        if (!strcasecmp(var, "old"))
  67                return DIFF_FILE_OLD;
  68        if (!strcasecmp(var, "new"))
  69                return DIFF_FILE_NEW;
  70        if (!strcasecmp(var, "commit"))
  71                return DIFF_COMMIT;
  72        if (!strcasecmp(var, "whitespace"))
  73                return DIFF_WHITESPACE;
  74        if (!strcasecmp(var, "func"))
  75                return DIFF_FUNCINFO;
  76        return -1;
  77}
  78
  79static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  80                                struct strbuf *errmsg)
  81{
  82        char *params_copy = xstrdup(params_string);
  83        struct string_list params = STRING_LIST_INIT_NODUP;
  84        int ret = 0;
  85        int i;
  86
  87        if (*params_copy)
  88                string_list_split_in_place(&params, params_copy, ',', -1);
  89        for (i = 0; i < params.nr; i++) {
  90                const char *p = params.items[i].string;
  91                if (!strcmp(p, "changes")) {
  92                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  93                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  94                } else if (!strcmp(p, "lines")) {
  95                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  96                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  97                } else if (!strcmp(p, "files")) {
  98                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  99                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 100                } else if (!strcmp(p, "noncumulative")) {
 101                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 102                } else if (!strcmp(p, "cumulative")) {
 103                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 104                } else if (isdigit(*p)) {
 105                        char *end;
 106                        int permille = strtoul(p, &end, 10) * 10;
 107                        if (*end == '.' && isdigit(*++end)) {
 108                                /* only use first digit */
 109                                permille += *end - '0';
 110                                /* .. and ignore any further digits */
 111                                while (isdigit(*++end))
 112                                        ; /* nothing */
 113                        }
 114                        if (!*end)
 115                                options->dirstat_permille = permille;
 116                        else {
 117                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 118                                            p);
 119                                ret++;
 120                        }
 121                } else {
 122                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 123                        ret++;
 124                }
 125
 126        }
 127        string_list_clear(&params, 0);
 128        free(params_copy);
 129        return ret;
 130}
 131
 132static int parse_submodule_params(struct diff_options *options, const char *value)
 133{
 134        if (!strcmp(value, "log"))
 135                options->submodule_format = DIFF_SUBMODULE_LOG;
 136        else if (!strcmp(value, "short"))
 137                options->submodule_format = DIFF_SUBMODULE_SHORT;
 138        else
 139                return -1;
 140        return 0;
 141}
 142
 143static int git_config_rename(const char *var, const char *value)
 144{
 145        if (!value)
 146                return DIFF_DETECT_RENAME;
 147        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 148                return  DIFF_DETECT_COPY;
 149        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 150}
 151
 152long parse_algorithm_value(const char *value)
 153{
 154        if (!value)
 155                return -1;
 156        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 157                return 0;
 158        else if (!strcasecmp(value, "minimal"))
 159                return XDF_NEED_MINIMAL;
 160        else if (!strcasecmp(value, "patience"))
 161                return XDF_PATIENCE_DIFF;
 162        else if (!strcasecmp(value, "histogram"))
 163                return XDF_HISTOGRAM_DIFF;
 164        return -1;
 165}
 166
 167/*
 168 * These are to give UI layer defaults.
 169 * The core-level commands such as git-diff-files should
 170 * never be affected by the setting of diff.renames
 171 * the user happens to have in the configuration file.
 172 */
 173void init_diff_ui_defaults(void)
 174{
 175        diff_detect_rename_default = 1;
 176}
 177
 178int git_diff_ui_config(const char *var, const char *value, void *cb)
 179{
 180        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 181                diff_use_color_default = git_config_colorbool(var, value);
 182                return 0;
 183        }
 184        if (!strcmp(var, "diff.context")) {
 185                diff_context_default = git_config_int(var, value);
 186                if (diff_context_default < 0)
 187                        return -1;
 188                return 0;
 189        }
 190        if (!strcmp(var, "diff.renames")) {
 191                diff_detect_rename_default = git_config_rename(var, value);
 192                return 0;
 193        }
 194        if (!strcmp(var, "diff.compactionheuristic")) {
 195                diff_compaction_heuristic = git_config_bool(var, value);
 196                return 0;
 197        }
 198        if (!strcmp(var, "diff.autorefreshindex")) {
 199                diff_auto_refresh_index = git_config_bool(var, value);
 200                return 0;
 201        }
 202        if (!strcmp(var, "diff.mnemonicprefix")) {
 203                diff_mnemonic_prefix = git_config_bool(var, value);
 204                return 0;
 205        }
 206        if (!strcmp(var, "diff.noprefix")) {
 207                diff_no_prefix = git_config_bool(var, value);
 208                return 0;
 209        }
 210        if (!strcmp(var, "diff.statgraphwidth")) {
 211                diff_stat_graph_width = git_config_int(var, value);
 212                return 0;
 213        }
 214        if (!strcmp(var, "diff.external"))
 215                return git_config_string(&external_diff_cmd_cfg, var, value);
 216        if (!strcmp(var, "diff.wordregex"))
 217                return git_config_string(&diff_word_regex_cfg, var, value);
 218        if (!strcmp(var, "diff.orderfile"))
 219                return git_config_pathname(&diff_order_file_cfg, var, value);
 220
 221        if (!strcmp(var, "diff.ignoresubmodules"))
 222                handle_ignore_submodules_arg(&default_diff_options, value);
 223
 224        if (!strcmp(var, "diff.submodule")) {
 225                if (parse_submodule_params(&default_diff_options, value))
 226                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 227                                value);
 228                return 0;
 229        }
 230
 231        if (!strcmp(var, "diff.algorithm")) {
 232                diff_algorithm = parse_algorithm_value(value);
 233                if (diff_algorithm < 0)
 234                        return -1;
 235                return 0;
 236        }
 237
 238        if (git_color_config(var, value, cb) < 0)
 239                return -1;
 240
 241        return git_diff_basic_config(var, value, cb);
 242}
 243
 244int git_diff_basic_config(const char *var, const char *value, void *cb)
 245{
 246        const char *name;
 247
 248        if (!strcmp(var, "diff.renamelimit")) {
 249                diff_rename_limit_default = git_config_int(var, value);
 250                return 0;
 251        }
 252
 253        if (userdiff_config(var, value) < 0)
 254                return -1;
 255
 256        if (skip_prefix(var, "diff.color.", &name) ||
 257            skip_prefix(var, "color.diff.", &name)) {
 258                int slot = parse_diff_color_slot(name);
 259                if (slot < 0)
 260                        return 0;
 261                if (!value)
 262                        return config_error_nonbool(var);
 263                return color_parse(value, diff_colors[slot]);
 264        }
 265
 266        /* like GNU diff's --suppress-blank-empty option  */
 267        if (!strcmp(var, "diff.suppressblankempty") ||
 268                        /* for backwards compatibility */
 269                        !strcmp(var, "diff.suppress-blank-empty")) {
 270                diff_suppress_blank_empty = git_config_bool(var, value);
 271                return 0;
 272        }
 273
 274        if (!strcmp(var, "diff.dirstat")) {
 275                struct strbuf errmsg = STRBUF_INIT;
 276                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 277                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 278                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 279                                errmsg.buf);
 280                strbuf_release(&errmsg);
 281                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 282                return 0;
 283        }
 284
 285        if (starts_with(var, "submodule."))
 286                return parse_submodule_config_option(var, value);
 287
 288        return git_default_config(var, value, cb);
 289}
 290
 291static char *quote_two(const char *one, const char *two)
 292{
 293        int need_one = quote_c_style(one, NULL, NULL, 1);
 294        int need_two = quote_c_style(two, NULL, NULL, 1);
 295        struct strbuf res = STRBUF_INIT;
 296
 297        if (need_one + need_two) {
 298                strbuf_addch(&res, '"');
 299                quote_c_style(one, &res, NULL, 1);
 300                quote_c_style(two, &res, NULL, 1);
 301                strbuf_addch(&res, '"');
 302        } else {
 303                strbuf_addstr(&res, one);
 304                strbuf_addstr(&res, two);
 305        }
 306        return strbuf_detach(&res, NULL);
 307}
 308
 309static const char *external_diff(void)
 310{
 311        static const char *external_diff_cmd = NULL;
 312        static int done_preparing = 0;
 313
 314        if (done_preparing)
 315                return external_diff_cmd;
 316        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 317        if (!external_diff_cmd)
 318                external_diff_cmd = external_diff_cmd_cfg;
 319        done_preparing = 1;
 320        return external_diff_cmd;
 321}
 322
 323/*
 324 * Keep track of files used for diffing. Sometimes such an entry
 325 * refers to a temporary file, sometimes to an existing file, and
 326 * sometimes to "/dev/null".
 327 */
 328static struct diff_tempfile {
 329        /*
 330         * filename external diff should read from, or NULL if this
 331         * entry is currently not in use:
 332         */
 333        const char *name;
 334
 335        char hex[GIT_SHA1_HEXSZ + 1];
 336        char mode[10];
 337
 338        /*
 339         * If this diff_tempfile instance refers to a temporary file,
 340         * this tempfile object is used to manage its lifetime.
 341         */
 342        struct tempfile tempfile;
 343} diff_temp[2];
 344
 345typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 346
 347struct emit_callback {
 348        int color_diff;
 349        unsigned ws_rule;
 350        int blank_at_eof_in_preimage;
 351        int blank_at_eof_in_postimage;
 352        int lno_in_preimage;
 353        int lno_in_postimage;
 354        sane_truncate_fn truncate;
 355        const char **label_path;
 356        struct diff_words_data *diff_words;
 357        struct diff_options *opt;
 358        int *found_changesp;
 359        struct strbuf *header;
 360};
 361
 362static int count_lines(const char *data, int size)
 363{
 364        int count, ch, completely_empty = 1, nl_just_seen = 0;
 365        count = 0;
 366        while (0 < size--) {
 367                ch = *data++;
 368                if (ch == '\n') {
 369                        count++;
 370                        nl_just_seen = 1;
 371                        completely_empty = 0;
 372                }
 373                else {
 374                        nl_just_seen = 0;
 375                        completely_empty = 0;
 376                }
 377        }
 378        if (completely_empty)
 379                return 0;
 380        if (!nl_just_seen)
 381                count++; /* no trailing newline */
 382        return count;
 383}
 384
 385static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 386{
 387        if (!DIFF_FILE_VALID(one)) {
 388                mf->ptr = (char *)""; /* does not matter */
 389                mf->size = 0;
 390                return 0;
 391        }
 392        else if (diff_populate_filespec(one, 0))
 393                return -1;
 394
 395        mf->ptr = one->data;
 396        mf->size = one->size;
 397        return 0;
 398}
 399
 400/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 401static unsigned long diff_filespec_size(struct diff_filespec *one)
 402{
 403        if (!DIFF_FILE_VALID(one))
 404                return 0;
 405        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 406        return one->size;
 407}
 408
 409static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 410{
 411        char *ptr = mf->ptr;
 412        long size = mf->size;
 413        int cnt = 0;
 414
 415        if (!size)
 416                return cnt;
 417        ptr += size - 1; /* pointing at the very end */
 418        if (*ptr != '\n')
 419                ; /* incomplete line */
 420        else
 421                ptr--; /* skip the last LF */
 422        while (mf->ptr < ptr) {
 423                char *prev_eol;
 424                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 425                        if (*prev_eol == '\n')
 426                                break;
 427                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 428                        break;
 429                cnt++;
 430                ptr = prev_eol - 1;
 431        }
 432        return cnt;
 433}
 434
 435static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 436                               struct emit_callback *ecbdata)
 437{
 438        int l1, l2, at;
 439        unsigned ws_rule = ecbdata->ws_rule;
 440        l1 = count_trailing_blank(mf1, ws_rule);
 441        l2 = count_trailing_blank(mf2, ws_rule);
 442        if (l2 <= l1) {
 443                ecbdata->blank_at_eof_in_preimage = 0;
 444                ecbdata->blank_at_eof_in_postimage = 0;
 445                return;
 446        }
 447        at = count_lines(mf1->ptr, mf1->size);
 448        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 449
 450        at = count_lines(mf2->ptr, mf2->size);
 451        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 452}
 453
 454static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 455                        int first, const char *line, int len)
 456{
 457        int has_trailing_newline, has_trailing_carriage_return;
 458        int nofirst;
 459        FILE *file = o->file;
 460
 461        fputs(diff_line_prefix(o), file);
 462
 463        if (len == 0) {
 464                has_trailing_newline = (first == '\n');
 465                has_trailing_carriage_return = (!has_trailing_newline &&
 466                                                (first == '\r'));
 467                nofirst = has_trailing_newline || has_trailing_carriage_return;
 468        } else {
 469                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 470                if (has_trailing_newline)
 471                        len--;
 472                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 473                if (has_trailing_carriage_return)
 474                        len--;
 475                nofirst = 0;
 476        }
 477
 478        if (len || !nofirst) {
 479                fputs(set, file);
 480                if (!nofirst)
 481                        fputc(first, file);
 482                fwrite(line, len, 1, file);
 483                fputs(reset, file);
 484        }
 485        if (has_trailing_carriage_return)
 486                fputc('\r', file);
 487        if (has_trailing_newline)
 488                fputc('\n', file);
 489}
 490
 491static void emit_line(struct diff_options *o, const char *set, const char *reset,
 492                      const char *line, int len)
 493{
 494        emit_line_0(o, set, reset, line[0], line+1, len-1);
 495}
 496
 497static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 498{
 499        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 500              ecbdata->blank_at_eof_in_preimage &&
 501              ecbdata->blank_at_eof_in_postimage &&
 502              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 503              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 504                return 0;
 505        return ws_blank_line(line, len, ecbdata->ws_rule);
 506}
 507
 508static void emit_line_checked(const char *reset,
 509                              struct emit_callback *ecbdata,
 510                              const char *line, int len,
 511                              enum color_diff color,
 512                              unsigned ws_error_highlight,
 513                              char sign)
 514{
 515        const char *set = diff_get_color(ecbdata->color_diff, color);
 516        const char *ws = NULL;
 517
 518        if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
 519                ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 520                if (!*ws)
 521                        ws = NULL;
 522        }
 523
 524        if (!ws)
 525                emit_line_0(ecbdata->opt, set, reset, sign, line, len);
 526        else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
 527                /* Blank line at EOF - paint '+' as well */
 528                emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
 529        else {
 530                /* Emit just the prefix, then the rest. */
 531                emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
 532                ws_check_emit(line, len, ecbdata->ws_rule,
 533                              ecbdata->opt->file, set, reset, ws);
 534        }
 535}
 536
 537static void emit_add_line(const char *reset,
 538                          struct emit_callback *ecbdata,
 539                          const char *line, int len)
 540{
 541        emit_line_checked(reset, ecbdata, line, len,
 542                          DIFF_FILE_NEW, WSEH_NEW, '+');
 543}
 544
 545static void emit_del_line(const char *reset,
 546                          struct emit_callback *ecbdata,
 547                          const char *line, int len)
 548{
 549        emit_line_checked(reset, ecbdata, line, len,
 550                          DIFF_FILE_OLD, WSEH_OLD, '-');
 551}
 552
 553static void emit_context_line(const char *reset,
 554                              struct emit_callback *ecbdata,
 555                              const char *line, int len)
 556{
 557        emit_line_checked(reset, ecbdata, line, len,
 558                          DIFF_CONTEXT, WSEH_CONTEXT, ' ');
 559}
 560
 561static void emit_hunk_header(struct emit_callback *ecbdata,
 562                             const char *line, int len)
 563{
 564        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 565        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 566        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 567        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 568        static const char atat[2] = { '@', '@' };
 569        const char *cp, *ep;
 570        struct strbuf msgbuf = STRBUF_INIT;
 571        int org_len = len;
 572        int i = 1;
 573
 574        /*
 575         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 576         * it always is at least 10 bytes long.
 577         */
 578        if (len < 10 ||
 579            memcmp(line, atat, 2) ||
 580            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 581                emit_line(ecbdata->opt, context, reset, line, len);
 582                return;
 583        }
 584        ep += 2; /* skip over @@ */
 585
 586        /* The hunk header in fraginfo color */
 587        strbuf_addstr(&msgbuf, frag);
 588        strbuf_add(&msgbuf, line, ep - line);
 589        strbuf_addstr(&msgbuf, reset);
 590
 591        /*
 592         * trailing "\r\n"
 593         */
 594        for ( ; i < 3; i++)
 595                if (line[len - i] == '\r' || line[len - i] == '\n')
 596                        len--;
 597
 598        /* blank before the func header */
 599        for (cp = ep; ep - line < len; ep++)
 600                if (*ep != ' ' && *ep != '\t')
 601                        break;
 602        if (ep != cp) {
 603                strbuf_addstr(&msgbuf, context);
 604                strbuf_add(&msgbuf, cp, ep - cp);
 605                strbuf_addstr(&msgbuf, reset);
 606        }
 607
 608        if (ep < line + len) {
 609                strbuf_addstr(&msgbuf, func);
 610                strbuf_add(&msgbuf, ep, line + len - ep);
 611                strbuf_addstr(&msgbuf, reset);
 612        }
 613
 614        strbuf_add(&msgbuf, line + len, org_len - len);
 615        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 616        strbuf_release(&msgbuf);
 617}
 618
 619static struct diff_tempfile *claim_diff_tempfile(void) {
 620        int i;
 621        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 622                if (!diff_temp[i].name)
 623                        return diff_temp + i;
 624        die("BUG: diff is failing to clean up its tempfiles");
 625}
 626
 627static void remove_tempfile(void)
 628{
 629        int i;
 630        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 631                if (is_tempfile_active(&diff_temp[i].tempfile))
 632                        delete_tempfile(&diff_temp[i].tempfile);
 633                diff_temp[i].name = NULL;
 634        }
 635}
 636
 637static void print_line_count(FILE *file, int count)
 638{
 639        switch (count) {
 640        case 0:
 641                fprintf(file, "0,0");
 642                break;
 643        case 1:
 644                fprintf(file, "1");
 645                break;
 646        default:
 647                fprintf(file, "1,%d", count);
 648                break;
 649        }
 650}
 651
 652static void emit_rewrite_lines(struct emit_callback *ecb,
 653                               int prefix, const char *data, int size)
 654{
 655        const char *endp = NULL;
 656        static const char *nneof = " No newline at end of file\n";
 657        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 658
 659        while (0 < size) {
 660                int len;
 661
 662                endp = memchr(data, '\n', size);
 663                len = endp ? (endp - data + 1) : size;
 664                if (prefix != '+') {
 665                        ecb->lno_in_preimage++;
 666                        emit_del_line(reset, ecb, data, len);
 667                } else {
 668                        ecb->lno_in_postimage++;
 669                        emit_add_line(reset, ecb, data, len);
 670                }
 671                size -= len;
 672                data += len;
 673        }
 674        if (!endp) {
 675                const char *context = diff_get_color(ecb->color_diff,
 676                                                     DIFF_CONTEXT);
 677                putc('\n', ecb->opt->file);
 678                emit_line_0(ecb->opt, context, reset, '\\',
 679                            nneof, strlen(nneof));
 680        }
 681}
 682
 683static void emit_rewrite_diff(const char *name_a,
 684                              const char *name_b,
 685                              struct diff_filespec *one,
 686                              struct diff_filespec *two,
 687                              struct userdiff_driver *textconv_one,
 688                              struct userdiff_driver *textconv_two,
 689                              struct diff_options *o)
 690{
 691        int lc_a, lc_b;
 692        const char *name_a_tab, *name_b_tab;
 693        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 694        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 695        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 696        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 697        const char *a_prefix, *b_prefix;
 698        char *data_one, *data_two;
 699        size_t size_one, size_two;
 700        struct emit_callback ecbdata;
 701        const char *line_prefix = diff_line_prefix(o);
 702
 703        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 704                a_prefix = o->b_prefix;
 705                b_prefix = o->a_prefix;
 706        } else {
 707                a_prefix = o->a_prefix;
 708                b_prefix = o->b_prefix;
 709        }
 710
 711        name_a += (*name_a == '/');
 712        name_b += (*name_b == '/');
 713        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 714        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 715
 716        strbuf_reset(&a_name);
 717        strbuf_reset(&b_name);
 718        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 719        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 720
 721        size_one = fill_textconv(textconv_one, one, &data_one);
 722        size_two = fill_textconv(textconv_two, two, &data_two);
 723
 724        memset(&ecbdata, 0, sizeof(ecbdata));
 725        ecbdata.color_diff = want_color(o->use_color);
 726        ecbdata.found_changesp = &o->found_changes;
 727        ecbdata.ws_rule = whitespace_rule(name_b);
 728        ecbdata.opt = o;
 729        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 730                mmfile_t mf1, mf2;
 731                mf1.ptr = (char *)data_one;
 732                mf2.ptr = (char *)data_two;
 733                mf1.size = size_one;
 734                mf2.size = size_two;
 735                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 736        }
 737        ecbdata.lno_in_preimage = 1;
 738        ecbdata.lno_in_postimage = 1;
 739
 740        lc_a = count_lines(data_one, size_one);
 741        lc_b = count_lines(data_two, size_two);
 742        fprintf(o->file,
 743                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 744                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 745                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 746                line_prefix, fraginfo);
 747        if (!o->irreversible_delete)
 748                print_line_count(o->file, lc_a);
 749        else
 750                fprintf(o->file, "?,?");
 751        fprintf(o->file, " +");
 752        print_line_count(o->file, lc_b);
 753        fprintf(o->file, " @@%s\n", reset);
 754        if (lc_a && !o->irreversible_delete)
 755                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 756        if (lc_b)
 757                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 758        if (textconv_one)
 759                free((char *)data_one);
 760        if (textconv_two)
 761                free((char *)data_two);
 762}
 763
 764struct diff_words_buffer {
 765        mmfile_t text;
 766        long alloc;
 767        struct diff_words_orig {
 768                const char *begin, *end;
 769        } *orig;
 770        int orig_nr, orig_alloc;
 771};
 772
 773static void diff_words_append(char *line, unsigned long len,
 774                struct diff_words_buffer *buffer)
 775{
 776        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 777        line++;
 778        len--;
 779        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 780        buffer->text.size += len;
 781        buffer->text.ptr[buffer->text.size] = '\0';
 782}
 783
 784struct diff_words_style_elem {
 785        const char *prefix;
 786        const char *suffix;
 787        const char *color; /* NULL; filled in by the setup code if
 788                            * color is enabled */
 789};
 790
 791struct diff_words_style {
 792        enum diff_words_type type;
 793        struct diff_words_style_elem new, old, ctx;
 794        const char *newline;
 795};
 796
 797static struct diff_words_style diff_words_styles[] = {
 798        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 799        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 800        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 801};
 802
 803struct diff_words_data {
 804        struct diff_words_buffer minus, plus;
 805        const char *current_plus;
 806        int last_minus;
 807        struct diff_options *opt;
 808        regex_t *word_regex;
 809        enum diff_words_type type;
 810        struct diff_words_style *style;
 811};
 812
 813static int fn_out_diff_words_write_helper(FILE *fp,
 814                                          struct diff_words_style_elem *st_el,
 815                                          const char *newline,
 816                                          size_t count, const char *buf,
 817                                          const char *line_prefix)
 818{
 819        int print = 0;
 820
 821        while (count) {
 822                char *p = memchr(buf, '\n', count);
 823                if (print)
 824                        fputs(line_prefix, fp);
 825                if (p != buf) {
 826                        if (st_el->color && fputs(st_el->color, fp) < 0)
 827                                return -1;
 828                        if (fputs(st_el->prefix, fp) < 0 ||
 829                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 830                            fputs(st_el->suffix, fp) < 0)
 831                                return -1;
 832                        if (st_el->color && *st_el->color
 833                            && fputs(GIT_COLOR_RESET, fp) < 0)
 834                                return -1;
 835                }
 836                if (!p)
 837                        return 0;
 838                if (fputs(newline, fp) < 0)
 839                        return -1;
 840                count -= p + 1 - buf;
 841                buf = p + 1;
 842                print = 1;
 843        }
 844        return 0;
 845}
 846
 847/*
 848 * '--color-words' algorithm can be described as:
 849 *
 850 *   1. collect a the minus/plus lines of a diff hunk, divided into
 851 *      minus-lines and plus-lines;
 852 *
 853 *   2. break both minus-lines and plus-lines into words and
 854 *      place them into two mmfile_t with one word for each line;
 855 *
 856 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 857 *
 858 * And for the common parts of the both file, we output the plus side text.
 859 * diff_words->current_plus is used to trace the current position of the plus file
 860 * which printed. diff_words->last_minus is used to trace the last minus word
 861 * printed.
 862 *
 863 * For '--graph' to work with '--color-words', we need to output the graph prefix
 864 * on each line of color words output. Generally, there are two conditions on
 865 * which we should output the prefix.
 866 *
 867 *   1. diff_words->last_minus == 0 &&
 868 *      diff_words->current_plus == diff_words->plus.text.ptr
 869 *
 870 *      that is: the plus text must start as a new line, and if there is no minus
 871 *      word printed, a graph prefix must be printed.
 872 *
 873 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 874 *      *(diff_words->current_plus - 1) == '\n'
 875 *
 876 *      that is: a graph prefix must be printed following a '\n'
 877 */
 878static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 879{
 880        if ((diff_words->last_minus == 0 &&
 881                diff_words->current_plus == diff_words->plus.text.ptr) ||
 882                (diff_words->current_plus > diff_words->plus.text.ptr &&
 883                *(diff_words->current_plus - 1) == '\n')) {
 884                return 1;
 885        } else {
 886                return 0;
 887        }
 888}
 889
 890static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 891{
 892        struct diff_words_data *diff_words = priv;
 893        struct diff_words_style *style = diff_words->style;
 894        int minus_first, minus_len, plus_first, plus_len;
 895        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 896        struct diff_options *opt = diff_words->opt;
 897        const char *line_prefix;
 898
 899        if (line[0] != '@' || parse_hunk_header(line, len,
 900                        &minus_first, &minus_len, &plus_first, &plus_len))
 901                return;
 902
 903        assert(opt);
 904        line_prefix = diff_line_prefix(opt);
 905
 906        /* POSIX requires that first be decremented by one if len == 0... */
 907        if (minus_len) {
 908                minus_begin = diff_words->minus.orig[minus_first].begin;
 909                minus_end =
 910                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 911        } else
 912                minus_begin = minus_end =
 913                        diff_words->minus.orig[minus_first].end;
 914
 915        if (plus_len) {
 916                plus_begin = diff_words->plus.orig[plus_first].begin;
 917                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 918        } else
 919                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 920
 921        if (color_words_output_graph_prefix(diff_words)) {
 922                fputs(line_prefix, diff_words->opt->file);
 923        }
 924        if (diff_words->current_plus != plus_begin) {
 925                fn_out_diff_words_write_helper(diff_words->opt->file,
 926                                &style->ctx, style->newline,
 927                                plus_begin - diff_words->current_plus,
 928                                diff_words->current_plus, line_prefix);
 929                if (*(plus_begin - 1) == '\n')
 930                        fputs(line_prefix, diff_words->opt->file);
 931        }
 932        if (minus_begin != minus_end) {
 933                fn_out_diff_words_write_helper(diff_words->opt->file,
 934                                &style->old, style->newline,
 935                                minus_end - minus_begin, minus_begin,
 936                                line_prefix);
 937        }
 938        if (plus_begin != plus_end) {
 939                fn_out_diff_words_write_helper(diff_words->opt->file,
 940                                &style->new, style->newline,
 941                                plus_end - plus_begin, plus_begin,
 942                                line_prefix);
 943        }
 944
 945        diff_words->current_plus = plus_end;
 946        diff_words->last_minus = minus_first;
 947}
 948
 949/* This function starts looking at *begin, and returns 0 iff a word was found. */
 950static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 951                int *begin, int *end)
 952{
 953        if (word_regex && *begin < buffer->size) {
 954                regmatch_t match[1];
 955                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 956                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 957                                        '\n', match[0].rm_eo - match[0].rm_so);
 958                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 959                        *begin += match[0].rm_so;
 960                        return *begin >= *end;
 961                }
 962                return -1;
 963        }
 964
 965        /* find the next word */
 966        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 967                (*begin)++;
 968        if (*begin >= buffer->size)
 969                return -1;
 970
 971        /* find the end of the word */
 972        *end = *begin + 1;
 973        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 974                (*end)++;
 975
 976        return 0;
 977}
 978
 979/*
 980 * This function splits the words in buffer->text, stores the list with
 981 * newline separator into out, and saves the offsets of the original words
 982 * in buffer->orig.
 983 */
 984static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 985                regex_t *word_regex)
 986{
 987        int i, j;
 988        long alloc = 0;
 989
 990        out->size = 0;
 991        out->ptr = NULL;
 992
 993        /* fake an empty "0th" word */
 994        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 995        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 996        buffer->orig_nr = 1;
 997
 998        for (i = 0; i < buffer->text.size; i++) {
 999                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1000                        return;
1001
1002                /* store original boundaries */
1003                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1004                                buffer->orig_alloc);
1005                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1006                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1007                buffer->orig_nr++;
1008
1009                /* store one word */
1010                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1011                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1012                out->ptr[out->size + j - i] = '\n';
1013                out->size += j - i + 1;
1014
1015                i = j - 1;
1016        }
1017}
1018
1019/* this executes the word diff on the accumulated buffers */
1020static void diff_words_show(struct diff_words_data *diff_words)
1021{
1022        xpparam_t xpp;
1023        xdemitconf_t xecfg;
1024        mmfile_t minus, plus;
1025        struct diff_words_style *style = diff_words->style;
1026
1027        struct diff_options *opt = diff_words->opt;
1028        const char *line_prefix;
1029
1030        assert(opt);
1031        line_prefix = diff_line_prefix(opt);
1032
1033        /* special case: only removal */
1034        if (!diff_words->plus.text.size) {
1035                fputs(line_prefix, diff_words->opt->file);
1036                fn_out_diff_words_write_helper(diff_words->opt->file,
1037                        &style->old, style->newline,
1038                        diff_words->minus.text.size,
1039                        diff_words->minus.text.ptr, line_prefix);
1040                diff_words->minus.text.size = 0;
1041                return;
1042        }
1043
1044        diff_words->current_plus = diff_words->plus.text.ptr;
1045        diff_words->last_minus = 0;
1046
1047        memset(&xpp, 0, sizeof(xpp));
1048        memset(&xecfg, 0, sizeof(xecfg));
1049        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1050        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1051        xpp.flags = 0;
1052        /* as only the hunk header will be parsed, we need a 0-context */
1053        xecfg.ctxlen = 0;
1054        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1055                          &xpp, &xecfg))
1056                die("unable to generate word diff");
1057        free(minus.ptr);
1058        free(plus.ptr);
1059        if (diff_words->current_plus != diff_words->plus.text.ptr +
1060                        diff_words->plus.text.size) {
1061                if (color_words_output_graph_prefix(diff_words))
1062                        fputs(line_prefix, diff_words->opt->file);
1063                fn_out_diff_words_write_helper(diff_words->opt->file,
1064                        &style->ctx, style->newline,
1065                        diff_words->plus.text.ptr + diff_words->plus.text.size
1066                        - diff_words->current_plus, diff_words->current_plus,
1067                        line_prefix);
1068        }
1069        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1070}
1071
1072/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1073static void diff_words_flush(struct emit_callback *ecbdata)
1074{
1075        if (ecbdata->diff_words->minus.text.size ||
1076            ecbdata->diff_words->plus.text.size)
1077                diff_words_show(ecbdata->diff_words);
1078}
1079
1080static void diff_filespec_load_driver(struct diff_filespec *one)
1081{
1082        /* Use already-loaded driver */
1083        if (one->driver)
1084                return;
1085
1086        if (S_ISREG(one->mode))
1087                one->driver = userdiff_find_by_path(one->path);
1088
1089        /* Fallback to default settings */
1090        if (!one->driver)
1091                one->driver = userdiff_find_by_name("default");
1092}
1093
1094static const char *userdiff_word_regex(struct diff_filespec *one)
1095{
1096        diff_filespec_load_driver(one);
1097        return one->driver->word_regex;
1098}
1099
1100static void init_diff_words_data(struct emit_callback *ecbdata,
1101                                 struct diff_options *orig_opts,
1102                                 struct diff_filespec *one,
1103                                 struct diff_filespec *two)
1104{
1105        int i;
1106        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1107        memcpy(o, orig_opts, sizeof(struct diff_options));
1108
1109        ecbdata->diff_words =
1110                xcalloc(1, sizeof(struct diff_words_data));
1111        ecbdata->diff_words->type = o->word_diff;
1112        ecbdata->diff_words->opt = o;
1113        if (!o->word_regex)
1114                o->word_regex = userdiff_word_regex(one);
1115        if (!o->word_regex)
1116                o->word_regex = userdiff_word_regex(two);
1117        if (!o->word_regex)
1118                o->word_regex = diff_word_regex_cfg;
1119        if (o->word_regex) {
1120                ecbdata->diff_words->word_regex = (regex_t *)
1121                        xmalloc(sizeof(regex_t));
1122                if (regcomp(ecbdata->diff_words->word_regex,
1123                            o->word_regex,
1124                            REG_EXTENDED | REG_NEWLINE))
1125                        die ("Invalid regular expression: %s",
1126                             o->word_regex);
1127        }
1128        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1129                if (o->word_diff == diff_words_styles[i].type) {
1130                        ecbdata->diff_words->style =
1131                                &diff_words_styles[i];
1132                        break;
1133                }
1134        }
1135        if (want_color(o->use_color)) {
1136                struct diff_words_style *st = ecbdata->diff_words->style;
1137                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1138                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1139                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1140        }
1141}
1142
1143static void free_diff_words_data(struct emit_callback *ecbdata)
1144{
1145        if (ecbdata->diff_words) {
1146                diff_words_flush(ecbdata);
1147                free (ecbdata->diff_words->opt);
1148                free (ecbdata->diff_words->minus.text.ptr);
1149                free (ecbdata->diff_words->minus.orig);
1150                free (ecbdata->diff_words->plus.text.ptr);
1151                free (ecbdata->diff_words->plus.orig);
1152                if (ecbdata->diff_words->word_regex) {
1153                        regfree(ecbdata->diff_words->word_regex);
1154                        free(ecbdata->diff_words->word_regex);
1155                }
1156                free(ecbdata->diff_words);
1157                ecbdata->diff_words = NULL;
1158        }
1159}
1160
1161const char *diff_get_color(int diff_use_color, enum color_diff ix)
1162{
1163        if (want_color(diff_use_color))
1164                return diff_colors[ix];
1165        return "";
1166}
1167
1168const char *diff_line_prefix(struct diff_options *opt)
1169{
1170        struct strbuf *msgbuf;
1171        if (!opt->output_prefix)
1172                return "";
1173
1174        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1175        return msgbuf->buf;
1176}
1177
1178static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1179{
1180        const char *cp;
1181        unsigned long allot;
1182        size_t l = len;
1183
1184        if (ecb->truncate)
1185                return ecb->truncate(line, len);
1186        cp = line;
1187        allot = l;
1188        while (0 < l) {
1189                (void) utf8_width(&cp, &l);
1190                if (!cp)
1191                        break; /* truncated in the middle? */
1192        }
1193        return allot - l;
1194}
1195
1196static void find_lno(const char *line, struct emit_callback *ecbdata)
1197{
1198        const char *p;
1199        ecbdata->lno_in_preimage = 0;
1200        ecbdata->lno_in_postimage = 0;
1201        p = strchr(line, '-');
1202        if (!p)
1203                return; /* cannot happen */
1204        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1205        p = strchr(p, '+');
1206        if (!p)
1207                return; /* cannot happen */
1208        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1209}
1210
1211static void fn_out_consume(void *priv, char *line, unsigned long len)
1212{
1213        struct emit_callback *ecbdata = priv;
1214        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1215        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1216        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1217        struct diff_options *o = ecbdata->opt;
1218        const char *line_prefix = diff_line_prefix(o);
1219
1220        if (ecbdata->header) {
1221                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1222                strbuf_reset(ecbdata->header);
1223                ecbdata->header = NULL;
1224        }
1225        *(ecbdata->found_changesp) = 1;
1226
1227        if (ecbdata->label_path[0]) {
1228                const char *name_a_tab, *name_b_tab;
1229
1230                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1231                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1232
1233                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1234                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1235                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1236                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1237                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1238        }
1239
1240        if (diff_suppress_blank_empty
1241            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1242                line[0] = '\n';
1243                len = 1;
1244        }
1245
1246        if (line[0] == '@') {
1247                if (ecbdata->diff_words)
1248                        diff_words_flush(ecbdata);
1249                len = sane_truncate_line(ecbdata, line, len);
1250                find_lno(line, ecbdata);
1251                emit_hunk_header(ecbdata, line, len);
1252                if (line[len-1] != '\n')
1253                        putc('\n', ecbdata->opt->file);
1254                return;
1255        }
1256
1257        if (len < 1) {
1258                emit_line(ecbdata->opt, reset, reset, line, len);
1259                if (ecbdata->diff_words
1260                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1261                        fputs("~\n", ecbdata->opt->file);
1262                return;
1263        }
1264
1265        if (ecbdata->diff_words) {
1266                if (line[0] == '-') {
1267                        diff_words_append(line, len,
1268                                          &ecbdata->diff_words->minus);
1269                        return;
1270                } else if (line[0] == '+') {
1271                        diff_words_append(line, len,
1272                                          &ecbdata->diff_words->plus);
1273                        return;
1274                } else if (starts_with(line, "\\ ")) {
1275                        /*
1276                         * Eat the "no newline at eof" marker as if we
1277                         * saw a "+" or "-" line with nothing on it,
1278                         * and return without diff_words_flush() to
1279                         * defer processing. If this is the end of
1280                         * preimage, more "+" lines may come after it.
1281                         */
1282                        return;
1283                }
1284                diff_words_flush(ecbdata);
1285                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1286                        emit_line(ecbdata->opt, context, reset, line, len);
1287                        fputs("~\n", ecbdata->opt->file);
1288                } else {
1289                        /*
1290                         * Skip the prefix character, if any.  With
1291                         * diff_suppress_blank_empty, there may be
1292                         * none.
1293                         */
1294                        if (line[0] != '\n') {
1295                              line++;
1296                              len--;
1297                        }
1298                        emit_line(ecbdata->opt, context, reset, line, len);
1299                }
1300                return;
1301        }
1302
1303        switch (line[0]) {
1304        case '+':
1305                ecbdata->lno_in_postimage++;
1306                emit_add_line(reset, ecbdata, line + 1, len - 1);
1307                break;
1308        case '-':
1309                ecbdata->lno_in_preimage++;
1310                emit_del_line(reset, ecbdata, line + 1, len - 1);
1311                break;
1312        case ' ':
1313                ecbdata->lno_in_postimage++;
1314                ecbdata->lno_in_preimage++;
1315                emit_context_line(reset, ecbdata, line + 1, len - 1);
1316                break;
1317        default:
1318                /* incomplete line at the end */
1319                ecbdata->lno_in_preimage++;
1320                emit_line(ecbdata->opt,
1321                          diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
1322                          reset, line, len);
1323                break;
1324        }
1325}
1326
1327static char *pprint_rename(const char *a, const char *b)
1328{
1329        const char *old = a;
1330        const char *new = b;
1331        struct strbuf name = STRBUF_INIT;
1332        int pfx_length, sfx_length;
1333        int pfx_adjust_for_slash;
1334        int len_a = strlen(a);
1335        int len_b = strlen(b);
1336        int a_midlen, b_midlen;
1337        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1338        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1339
1340        if (qlen_a || qlen_b) {
1341                quote_c_style(a, &name, NULL, 0);
1342                strbuf_addstr(&name, " => ");
1343                quote_c_style(b, &name, NULL, 0);
1344                return strbuf_detach(&name, NULL);
1345        }
1346
1347        /* Find common prefix */
1348        pfx_length = 0;
1349        while (*old && *new && *old == *new) {
1350                if (*old == '/')
1351                        pfx_length = old - a + 1;
1352                old++;
1353                new++;
1354        }
1355
1356        /* Find common suffix */
1357        old = a + len_a;
1358        new = b + len_b;
1359        sfx_length = 0;
1360        /*
1361         * If there is a common prefix, it must end in a slash.  In
1362         * that case we let this loop run 1 into the prefix to see the
1363         * same slash.
1364         *
1365         * If there is no common prefix, we cannot do this as it would
1366         * underrun the input strings.
1367         */
1368        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1369        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1370               b + pfx_length - pfx_adjust_for_slash <= new &&
1371               *old == *new) {
1372                if (*old == '/')
1373                        sfx_length = len_a - (old - a);
1374                old--;
1375                new--;
1376        }
1377
1378        /*
1379         * pfx{mid-a => mid-b}sfx
1380         * {pfx-a => pfx-b}sfx
1381         * pfx{sfx-a => sfx-b}
1382         * name-a => name-b
1383         */
1384        a_midlen = len_a - pfx_length - sfx_length;
1385        b_midlen = len_b - pfx_length - sfx_length;
1386        if (a_midlen < 0)
1387                a_midlen = 0;
1388        if (b_midlen < 0)
1389                b_midlen = 0;
1390
1391        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1392        if (pfx_length + sfx_length) {
1393                strbuf_add(&name, a, pfx_length);
1394                strbuf_addch(&name, '{');
1395        }
1396        strbuf_add(&name, a + pfx_length, a_midlen);
1397        strbuf_addstr(&name, " => ");
1398        strbuf_add(&name, b + pfx_length, b_midlen);
1399        if (pfx_length + sfx_length) {
1400                strbuf_addch(&name, '}');
1401                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1402        }
1403        return strbuf_detach(&name, NULL);
1404}
1405
1406struct diffstat_t {
1407        int nr;
1408        int alloc;
1409        struct diffstat_file {
1410                char *from_name;
1411                char *name;
1412                char *print_name;
1413                unsigned is_unmerged:1;
1414                unsigned is_binary:1;
1415                unsigned is_renamed:1;
1416                unsigned is_interesting:1;
1417                uintmax_t added, deleted;
1418        } **files;
1419};
1420
1421static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1422                                          const char *name_a,
1423                                          const char *name_b)
1424{
1425        struct diffstat_file *x;
1426        x = xcalloc(1, sizeof(*x));
1427        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1428        diffstat->files[diffstat->nr++] = x;
1429        if (name_b) {
1430                x->from_name = xstrdup(name_a);
1431                x->name = xstrdup(name_b);
1432                x->is_renamed = 1;
1433        }
1434        else {
1435                x->from_name = NULL;
1436                x->name = xstrdup(name_a);
1437        }
1438        return x;
1439}
1440
1441static void diffstat_consume(void *priv, char *line, unsigned long len)
1442{
1443        struct diffstat_t *diffstat = priv;
1444        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1445
1446        if (line[0] == '+')
1447                x->added++;
1448        else if (line[0] == '-')
1449                x->deleted++;
1450}
1451
1452const char mime_boundary_leader[] = "------------";
1453
1454static int scale_linear(int it, int width, int max_change)
1455{
1456        if (!it)
1457                return 0;
1458        /*
1459         * make sure that at least one '-' or '+' is printed if
1460         * there is any change to this path. The easiest way is to
1461         * scale linearly as if the alloted width is one column shorter
1462         * than it is, and then add 1 to the result.
1463         */
1464        return 1 + (it * (width - 1) / max_change);
1465}
1466
1467static void show_name(FILE *file,
1468                      const char *prefix, const char *name, int len)
1469{
1470        fprintf(file, " %s%-*s |", prefix, len, name);
1471}
1472
1473static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1474{
1475        if (cnt <= 0)
1476                return;
1477        fprintf(file, "%s", set);
1478        while (cnt--)
1479                putc(ch, file);
1480        fprintf(file, "%s", reset);
1481}
1482
1483static void fill_print_name(struct diffstat_file *file)
1484{
1485        char *pname;
1486
1487        if (file->print_name)
1488                return;
1489
1490        if (!file->is_renamed) {
1491                struct strbuf buf = STRBUF_INIT;
1492                if (quote_c_style(file->name, &buf, NULL, 0)) {
1493                        pname = strbuf_detach(&buf, NULL);
1494                } else {
1495                        pname = file->name;
1496                        strbuf_release(&buf);
1497                }
1498        } else {
1499                pname = pprint_rename(file->from_name, file->name);
1500        }
1501        file->print_name = pname;
1502}
1503
1504int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1505{
1506        struct strbuf sb = STRBUF_INIT;
1507        int ret;
1508
1509        if (!files) {
1510                assert(insertions == 0 && deletions == 0);
1511                return fprintf(fp, "%s\n", " 0 files changed");
1512        }
1513
1514        strbuf_addf(&sb,
1515                    (files == 1) ? " %d file changed" : " %d files changed",
1516                    files);
1517
1518        /*
1519         * For binary diff, the caller may want to print "x files
1520         * changed" with insertions == 0 && deletions == 0.
1521         *
1522         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1523         * is probably less confusing (i.e skip over "2 files changed
1524         * but nothing about added/removed lines? Is this a bug in Git?").
1525         */
1526        if (insertions || deletions == 0) {
1527                strbuf_addf(&sb,
1528                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1529                            insertions);
1530        }
1531
1532        if (deletions || insertions == 0) {
1533                strbuf_addf(&sb,
1534                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1535                            deletions);
1536        }
1537        strbuf_addch(&sb, '\n');
1538        ret = fputs(sb.buf, fp);
1539        strbuf_release(&sb);
1540        return ret;
1541}
1542
1543static void show_stats(struct diffstat_t *data, struct diff_options *options)
1544{
1545        int i, len, add, del, adds = 0, dels = 0;
1546        uintmax_t max_change = 0, max_len = 0;
1547        int total_files = data->nr, count;
1548        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1549        const char *reset, *add_c, *del_c;
1550        const char *line_prefix = "";
1551        int extra_shown = 0;
1552
1553        if (data->nr == 0)
1554                return;
1555
1556        line_prefix = diff_line_prefix(options);
1557        count = options->stat_count ? options->stat_count : data->nr;
1558
1559        reset = diff_get_color_opt(options, DIFF_RESET);
1560        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1561        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1562
1563        /*
1564         * Find the longest filename and max number of changes
1565         */
1566        for (i = 0; (i < count) && (i < data->nr); i++) {
1567                struct diffstat_file *file = data->files[i];
1568                uintmax_t change = file->added + file->deleted;
1569
1570                if (!file->is_interesting && (change == 0)) {
1571                        count++; /* not shown == room for one more */
1572                        continue;
1573                }
1574                fill_print_name(file);
1575                len = strlen(file->print_name);
1576                if (max_len < len)
1577                        max_len = len;
1578
1579                if (file->is_unmerged) {
1580                        /* "Unmerged" is 8 characters */
1581                        bin_width = bin_width < 8 ? 8 : bin_width;
1582                        continue;
1583                }
1584                if (file->is_binary) {
1585                        /* "Bin XXX -> YYY bytes" */
1586                        int w = 14 + decimal_width(file->added)
1587                                + decimal_width(file->deleted);
1588                        bin_width = bin_width < w ? w : bin_width;
1589                        /* Display change counts aligned with "Bin" */
1590                        number_width = 3;
1591                        continue;
1592                }
1593
1594                if (max_change < change)
1595                        max_change = change;
1596        }
1597        count = i; /* where we can stop scanning in data->files[] */
1598
1599        /*
1600         * We have width = stat_width or term_columns() columns total.
1601         * We want a maximum of min(max_len, stat_name_width) for the name part.
1602         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1603         * We also need 1 for " " and 4 + decimal_width(max_change)
1604         * for " | NNNN " and one the empty column at the end, altogether
1605         * 6 + decimal_width(max_change).
1606         *
1607         * If there's not enough space, we will use the smaller of
1608         * stat_name_width (if set) and 5/8*width for the filename,
1609         * and the rest for constant elements + graph part, but no more
1610         * than stat_graph_width for the graph part.
1611         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1612         * for the standard terminal size).
1613         *
1614         * In other words: stat_width limits the maximum width, and
1615         * stat_name_width fixes the maximum width of the filename,
1616         * and is also used to divide available columns if there
1617         * aren't enough.
1618         *
1619         * Binary files are displayed with "Bin XXX -> YYY bytes"
1620         * instead of the change count and graph. This part is treated
1621         * similarly to the graph part, except that it is not
1622         * "scaled". If total width is too small to accommodate the
1623         * guaranteed minimum width of the filename part and the
1624         * separators and this message, this message will "overflow"
1625         * making the line longer than the maximum width.
1626         */
1627
1628        if (options->stat_width == -1)
1629                width = term_columns() - strlen(line_prefix);
1630        else
1631                width = options->stat_width ? options->stat_width : 80;
1632        number_width = decimal_width(max_change) > number_width ?
1633                decimal_width(max_change) : number_width;
1634
1635        if (options->stat_graph_width == -1)
1636                options->stat_graph_width = diff_stat_graph_width;
1637
1638        /*
1639         * Guarantee 3/8*16==6 for the graph part
1640         * and 5/8*16==10 for the filename part
1641         */
1642        if (width < 16 + 6 + number_width)
1643                width = 16 + 6 + number_width;
1644
1645        /*
1646         * First assign sizes that are wanted, ignoring available width.
1647         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1648         * starting from "XXX" should fit in graph_width.
1649         */
1650        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1651        if (options->stat_graph_width &&
1652            options->stat_graph_width < graph_width)
1653                graph_width = options->stat_graph_width;
1654
1655        name_width = (options->stat_name_width > 0 &&
1656                      options->stat_name_width < max_len) ?
1657                options->stat_name_width : max_len;
1658
1659        /*
1660         * Adjust adjustable widths not to exceed maximum width
1661         */
1662        if (name_width + number_width + 6 + graph_width > width) {
1663                if (graph_width > width * 3/8 - number_width - 6) {
1664                        graph_width = width * 3/8 - number_width - 6;
1665                        if (graph_width < 6)
1666                                graph_width = 6;
1667                }
1668
1669                if (options->stat_graph_width &&
1670                    graph_width > options->stat_graph_width)
1671                        graph_width = options->stat_graph_width;
1672                if (name_width > width - number_width - 6 - graph_width)
1673                        name_width = width - number_width - 6 - graph_width;
1674                else
1675                        graph_width = width - number_width - 6 - name_width;
1676        }
1677
1678        /*
1679         * From here name_width is the width of the name area,
1680         * and graph_width is the width of the graph area.
1681         * max_change is used to scale graph properly.
1682         */
1683        for (i = 0; i < count; i++) {
1684                const char *prefix = "";
1685                struct diffstat_file *file = data->files[i];
1686                char *name = file->print_name;
1687                uintmax_t added = file->added;
1688                uintmax_t deleted = file->deleted;
1689                int name_len;
1690
1691                if (!file->is_interesting && (added + deleted == 0))
1692                        continue;
1693
1694                /*
1695                 * "scale" the filename
1696                 */
1697                len = name_width;
1698                name_len = strlen(name);
1699                if (name_width < name_len) {
1700                        char *slash;
1701                        prefix = "...";
1702                        len -= 3;
1703                        name += name_len - len;
1704                        slash = strchr(name, '/');
1705                        if (slash)
1706                                name = slash;
1707                }
1708
1709                if (file->is_binary) {
1710                        fprintf(options->file, "%s", line_prefix);
1711                        show_name(options->file, prefix, name, len);
1712                        fprintf(options->file, " %*s", number_width, "Bin");
1713                        if (!added && !deleted) {
1714                                putc('\n', options->file);
1715                                continue;
1716                        }
1717                        fprintf(options->file, " %s%"PRIuMAX"%s",
1718                                del_c, deleted, reset);
1719                        fprintf(options->file, " -> ");
1720                        fprintf(options->file, "%s%"PRIuMAX"%s",
1721                                add_c, added, reset);
1722                        fprintf(options->file, " bytes");
1723                        fprintf(options->file, "\n");
1724                        continue;
1725                }
1726                else if (file->is_unmerged) {
1727                        fprintf(options->file, "%s", line_prefix);
1728                        show_name(options->file, prefix, name, len);
1729                        fprintf(options->file, " Unmerged\n");
1730                        continue;
1731                }
1732
1733                /*
1734                 * scale the add/delete
1735                 */
1736                add = added;
1737                del = deleted;
1738
1739                if (graph_width <= max_change) {
1740                        int total = scale_linear(add + del, graph_width, max_change);
1741                        if (total < 2 && add && del)
1742                                /* width >= 2 due to the sanity check */
1743                                total = 2;
1744                        if (add < del) {
1745                                add = scale_linear(add, graph_width, max_change);
1746                                del = total - add;
1747                        } else {
1748                                del = scale_linear(del, graph_width, max_change);
1749                                add = total - del;
1750                        }
1751                }
1752                fprintf(options->file, "%s", line_prefix);
1753                show_name(options->file, prefix, name, len);
1754                fprintf(options->file, " %*"PRIuMAX"%s",
1755                        number_width, added + deleted,
1756                        added + deleted ? " " : "");
1757                show_graph(options->file, '+', add, add_c, reset);
1758                show_graph(options->file, '-', del, del_c, reset);
1759                fprintf(options->file, "\n");
1760        }
1761
1762        for (i = 0; i < data->nr; i++) {
1763                struct diffstat_file *file = data->files[i];
1764                uintmax_t added = file->added;
1765                uintmax_t deleted = file->deleted;
1766
1767                if (file->is_unmerged ||
1768                    (!file->is_interesting && (added + deleted == 0))) {
1769                        total_files--;
1770                        continue;
1771                }
1772
1773                if (!file->is_binary) {
1774                        adds += added;
1775                        dels += deleted;
1776                }
1777                if (i < count)
1778                        continue;
1779                if (!extra_shown)
1780                        fprintf(options->file, "%s ...\n", line_prefix);
1781                extra_shown = 1;
1782        }
1783        fprintf(options->file, "%s", line_prefix);
1784        print_stat_summary(options->file, total_files, adds, dels);
1785}
1786
1787static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1788{
1789        int i, adds = 0, dels = 0, total_files = data->nr;
1790
1791        if (data->nr == 0)
1792                return;
1793
1794        for (i = 0; i < data->nr; i++) {
1795                int added = data->files[i]->added;
1796                int deleted= data->files[i]->deleted;
1797
1798                if (data->files[i]->is_unmerged ||
1799                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1800                        total_files--;
1801                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1802                        adds += added;
1803                        dels += deleted;
1804                }
1805        }
1806        fprintf(options->file, "%s", diff_line_prefix(options));
1807        print_stat_summary(options->file, total_files, adds, dels);
1808}
1809
1810static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1811{
1812        int i;
1813
1814        if (data->nr == 0)
1815                return;
1816
1817        for (i = 0; i < data->nr; i++) {
1818                struct diffstat_file *file = data->files[i];
1819
1820                fprintf(options->file, "%s", diff_line_prefix(options));
1821
1822                if (file->is_binary)
1823                        fprintf(options->file, "-\t-\t");
1824                else
1825                        fprintf(options->file,
1826                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1827                                file->added, file->deleted);
1828                if (options->line_termination) {
1829                        fill_print_name(file);
1830                        if (!file->is_renamed)
1831                                write_name_quoted(file->name, options->file,
1832                                                  options->line_termination);
1833                        else {
1834                                fputs(file->print_name, options->file);
1835                                putc(options->line_termination, options->file);
1836                        }
1837                } else {
1838                        if (file->is_renamed) {
1839                                putc('\0', options->file);
1840                                write_name_quoted(file->from_name, options->file, '\0');
1841                        }
1842                        write_name_quoted(file->name, options->file, '\0');
1843                }
1844        }
1845}
1846
1847struct dirstat_file {
1848        const char *name;
1849        unsigned long changed;
1850};
1851
1852struct dirstat_dir {
1853        struct dirstat_file *files;
1854        int alloc, nr, permille, cumulative;
1855};
1856
1857static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1858                unsigned long changed, const char *base, int baselen)
1859{
1860        unsigned long this_dir = 0;
1861        unsigned int sources = 0;
1862        const char *line_prefix = diff_line_prefix(opt);
1863
1864        while (dir->nr) {
1865                struct dirstat_file *f = dir->files;
1866                int namelen = strlen(f->name);
1867                unsigned long this;
1868                char *slash;
1869
1870                if (namelen < baselen)
1871                        break;
1872                if (memcmp(f->name, base, baselen))
1873                        break;
1874                slash = strchr(f->name + baselen, '/');
1875                if (slash) {
1876                        int newbaselen = slash + 1 - f->name;
1877                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1878                        sources++;
1879                } else {
1880                        this = f->changed;
1881                        dir->files++;
1882                        dir->nr--;
1883                        sources += 2;
1884                }
1885                this_dir += this;
1886        }
1887
1888        /*
1889         * We don't report dirstat's for
1890         *  - the top level
1891         *  - or cases where everything came from a single directory
1892         *    under this directory (sources == 1).
1893         */
1894        if (baselen && sources != 1) {
1895                if (this_dir) {
1896                        int permille = this_dir * 1000 / changed;
1897                        if (permille >= dir->permille) {
1898                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1899                                        permille / 10, permille % 10, baselen, base);
1900                                if (!dir->cumulative)
1901                                        return 0;
1902                        }
1903                }
1904        }
1905        return this_dir;
1906}
1907
1908static int dirstat_compare(const void *_a, const void *_b)
1909{
1910        const struct dirstat_file *a = _a;
1911        const struct dirstat_file *b = _b;
1912        return strcmp(a->name, b->name);
1913}
1914
1915static void show_dirstat(struct diff_options *options)
1916{
1917        int i;
1918        unsigned long changed;
1919        struct dirstat_dir dir;
1920        struct diff_queue_struct *q = &diff_queued_diff;
1921
1922        dir.files = NULL;
1923        dir.alloc = 0;
1924        dir.nr = 0;
1925        dir.permille = options->dirstat_permille;
1926        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1927
1928        changed = 0;
1929        for (i = 0; i < q->nr; i++) {
1930                struct diff_filepair *p = q->queue[i];
1931                const char *name;
1932                unsigned long copied, added, damage;
1933                int content_changed;
1934
1935                name = p->two->path ? p->two->path : p->one->path;
1936
1937                if (p->one->oid_valid && p->two->oid_valid)
1938                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
1939                else
1940                        content_changed = 1;
1941
1942                if (!content_changed) {
1943                        /*
1944                         * The SHA1 has not changed, so pre-/post-content is
1945                         * identical. We can therefore skip looking at the
1946                         * file contents altogether.
1947                         */
1948                        damage = 0;
1949                        goto found_damage;
1950                }
1951
1952                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1953                        /*
1954                         * In --dirstat-by-file mode, we don't really need to
1955                         * look at the actual file contents at all.
1956                         * The fact that the SHA1 changed is enough for us to
1957                         * add this file to the list of results
1958                         * (with each file contributing equal damage).
1959                         */
1960                        damage = 1;
1961                        goto found_damage;
1962                }
1963
1964                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1965                        diff_populate_filespec(p->one, 0);
1966                        diff_populate_filespec(p->two, 0);
1967                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1968                                               &copied, &added);
1969                        diff_free_filespec_data(p->one);
1970                        diff_free_filespec_data(p->two);
1971                } else if (DIFF_FILE_VALID(p->one)) {
1972                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
1973                        copied = added = 0;
1974                        diff_free_filespec_data(p->one);
1975                } else if (DIFF_FILE_VALID(p->two)) {
1976                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
1977                        copied = 0;
1978                        added = p->two->size;
1979                        diff_free_filespec_data(p->two);
1980                } else
1981                        continue;
1982
1983                /*
1984                 * Original minus copied is the removed material,
1985                 * added is the new material.  They are both damages
1986                 * made to the preimage.
1987                 * If the resulting damage is zero, we know that
1988                 * diffcore_count_changes() considers the two entries to
1989                 * be identical, but since content_changed is true, we
1990                 * know that there must have been _some_ kind of change,
1991                 * so we force all entries to have damage > 0.
1992                 */
1993                damage = (p->one->size - copied) + added;
1994                if (!damage)
1995                        damage = 1;
1996
1997found_damage:
1998                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1999                dir.files[dir.nr].name = name;
2000                dir.files[dir.nr].changed = damage;
2001                changed += damage;
2002                dir.nr++;
2003        }
2004
2005        /* This can happen even with many files, if everything was renames */
2006        if (!changed)
2007                return;
2008
2009        /* Show all directories with more than x% of the changes */
2010        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2011        gather_dirstat(options, &dir, changed, "", 0);
2012}
2013
2014static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2015{
2016        int i;
2017        unsigned long changed;
2018        struct dirstat_dir dir;
2019
2020        if (data->nr == 0)
2021                return;
2022
2023        dir.files = NULL;
2024        dir.alloc = 0;
2025        dir.nr = 0;
2026        dir.permille = options->dirstat_permille;
2027        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2028
2029        changed = 0;
2030        for (i = 0; i < data->nr; i++) {
2031                struct diffstat_file *file = data->files[i];
2032                unsigned long damage = file->added + file->deleted;
2033                if (file->is_binary)
2034                        /*
2035                         * binary files counts bytes, not lines. Must find some
2036                         * way to normalize binary bytes vs. textual lines.
2037                         * The following heuristic assumes that there are 64
2038                         * bytes per "line".
2039                         * This is stupid and ugly, but very cheap...
2040                         */
2041                        damage = (damage + 63) / 64;
2042                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2043                dir.files[dir.nr].name = file->name;
2044                dir.files[dir.nr].changed = damage;
2045                changed += damage;
2046                dir.nr++;
2047        }
2048
2049        /* This can happen even with many files, if everything was renames */
2050        if (!changed)
2051                return;
2052
2053        /* Show all directories with more than x% of the changes */
2054        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2055        gather_dirstat(options, &dir, changed, "", 0);
2056}
2057
2058static void free_diffstat_info(struct diffstat_t *diffstat)
2059{
2060        int i;
2061        for (i = 0; i < diffstat->nr; i++) {
2062                struct diffstat_file *f = diffstat->files[i];
2063                if (f->name != f->print_name)
2064                        free(f->print_name);
2065                free(f->name);
2066                free(f->from_name);
2067                free(f);
2068        }
2069        free(diffstat->files);
2070}
2071
2072struct checkdiff_t {
2073        const char *filename;
2074        int lineno;
2075        int conflict_marker_size;
2076        struct diff_options *o;
2077        unsigned ws_rule;
2078        unsigned status;
2079};
2080
2081static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2082{
2083        char firstchar;
2084        int cnt;
2085
2086        if (len < marker_size + 1)
2087                return 0;
2088        firstchar = line[0];
2089        switch (firstchar) {
2090        case '=': case '>': case '<': case '|':
2091                break;
2092        default:
2093                return 0;
2094        }
2095        for (cnt = 1; cnt < marker_size; cnt++)
2096                if (line[cnt] != firstchar)
2097                        return 0;
2098        /* line[1] thru line[marker_size-1] are same as firstchar */
2099        if (len < marker_size + 1 || !isspace(line[marker_size]))
2100                return 0;
2101        return 1;
2102}
2103
2104static void checkdiff_consume(void *priv, char *line, unsigned long len)
2105{
2106        struct checkdiff_t *data = priv;
2107        int marker_size = data->conflict_marker_size;
2108        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2109        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2110        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2111        char *err;
2112        const char *line_prefix;
2113
2114        assert(data->o);
2115        line_prefix = diff_line_prefix(data->o);
2116
2117        if (line[0] == '+') {
2118                unsigned bad;
2119                data->lineno++;
2120                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2121                        data->status |= 1;
2122                        fprintf(data->o->file,
2123                                "%s%s:%d: leftover conflict marker\n",
2124                                line_prefix, data->filename, data->lineno);
2125                }
2126                bad = ws_check(line + 1, len - 1, data->ws_rule);
2127                if (!bad)
2128                        return;
2129                data->status |= bad;
2130                err = whitespace_error_string(bad);
2131                fprintf(data->o->file, "%s%s:%d: %s.\n",
2132                        line_prefix, data->filename, data->lineno, err);
2133                free(err);
2134                emit_line(data->o, set, reset, line, 1);
2135                ws_check_emit(line + 1, len - 1, data->ws_rule,
2136                              data->o->file, set, reset, ws);
2137        } else if (line[0] == ' ') {
2138                data->lineno++;
2139        } else if (line[0] == '@') {
2140                char *plus = strchr(line, '+');
2141                if (plus)
2142                        data->lineno = strtol(plus, NULL, 10) - 1;
2143                else
2144                        die("invalid diff");
2145        }
2146}
2147
2148static unsigned char *deflate_it(char *data,
2149                                 unsigned long size,
2150                                 unsigned long *result_size)
2151{
2152        int bound;
2153        unsigned char *deflated;
2154        git_zstream stream;
2155
2156        git_deflate_init(&stream, zlib_compression_level);
2157        bound = git_deflate_bound(&stream, size);
2158        deflated = xmalloc(bound);
2159        stream.next_out = deflated;
2160        stream.avail_out = bound;
2161
2162        stream.next_in = (unsigned char *)data;
2163        stream.avail_in = size;
2164        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2165                ; /* nothing */
2166        git_deflate_end(&stream);
2167        *result_size = stream.total_out;
2168        return deflated;
2169}
2170
2171static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2172                                  const char *prefix)
2173{
2174        void *cp;
2175        void *delta;
2176        void *deflated;
2177        void *data;
2178        unsigned long orig_size;
2179        unsigned long delta_size;
2180        unsigned long deflate_size;
2181        unsigned long data_size;
2182
2183        /* We could do deflated delta, or we could do just deflated two,
2184         * whichever is smaller.
2185         */
2186        delta = NULL;
2187        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2188        if (one->size && two->size) {
2189                delta = diff_delta(one->ptr, one->size,
2190                                   two->ptr, two->size,
2191                                   &delta_size, deflate_size);
2192                if (delta) {
2193                        void *to_free = delta;
2194                        orig_size = delta_size;
2195                        delta = deflate_it(delta, delta_size, &delta_size);
2196                        free(to_free);
2197                }
2198        }
2199
2200        if (delta && delta_size < deflate_size) {
2201                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2202                free(deflated);
2203                data = delta;
2204                data_size = delta_size;
2205        }
2206        else {
2207                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2208                free(delta);
2209                data = deflated;
2210                data_size = deflate_size;
2211        }
2212
2213        /* emit data encoded in base85 */
2214        cp = data;
2215        while (data_size) {
2216                int bytes = (52 < data_size) ? 52 : data_size;
2217                char line[70];
2218                data_size -= bytes;
2219                if (bytes <= 26)
2220                        line[0] = bytes + 'A' - 1;
2221                else
2222                        line[0] = bytes - 26 + 'a' - 1;
2223                encode_85(line + 1, cp, bytes);
2224                cp = (char *) cp + bytes;
2225                fprintf(file, "%s", prefix);
2226                fputs(line, file);
2227                fputc('\n', file);
2228        }
2229        fprintf(file, "%s\n", prefix);
2230        free(data);
2231}
2232
2233static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2234                             const char *prefix)
2235{
2236        fprintf(file, "%sGIT binary patch\n", prefix);
2237        emit_binary_diff_body(file, one, two, prefix);
2238        emit_binary_diff_body(file, two, one, prefix);
2239}
2240
2241int diff_filespec_is_binary(struct diff_filespec *one)
2242{
2243        if (one->is_binary == -1) {
2244                diff_filespec_load_driver(one);
2245                if (one->driver->binary != -1)
2246                        one->is_binary = one->driver->binary;
2247                else {
2248                        if (!one->data && DIFF_FILE_VALID(one))
2249                                diff_populate_filespec(one, CHECK_BINARY);
2250                        if (one->is_binary == -1 && one->data)
2251                                one->is_binary = buffer_is_binary(one->data,
2252                                                one->size);
2253                        if (one->is_binary == -1)
2254                                one->is_binary = 0;
2255                }
2256        }
2257        return one->is_binary;
2258}
2259
2260static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2261{
2262        diff_filespec_load_driver(one);
2263        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2264}
2265
2266void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2267{
2268        if (!options->a_prefix)
2269                options->a_prefix = a;
2270        if (!options->b_prefix)
2271                options->b_prefix = b;
2272}
2273
2274struct userdiff_driver *get_textconv(struct diff_filespec *one)
2275{
2276        if (!DIFF_FILE_VALID(one))
2277                return NULL;
2278
2279        diff_filespec_load_driver(one);
2280        return userdiff_get_textconv(one->driver);
2281}
2282
2283static void builtin_diff(const char *name_a,
2284                         const char *name_b,
2285                         struct diff_filespec *one,
2286                         struct diff_filespec *two,
2287                         const char *xfrm_msg,
2288                         int must_show_header,
2289                         struct diff_options *o,
2290                         int complete_rewrite)
2291{
2292        mmfile_t mf1, mf2;
2293        const char *lbl[2];
2294        char *a_one, *b_two;
2295        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2296        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2297        const char *a_prefix, *b_prefix;
2298        struct userdiff_driver *textconv_one = NULL;
2299        struct userdiff_driver *textconv_two = NULL;
2300        struct strbuf header = STRBUF_INIT;
2301        const char *line_prefix = diff_line_prefix(o);
2302
2303        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2304            (!one->mode || S_ISGITLINK(one->mode)) &&
2305            (!two->mode || S_ISGITLINK(two->mode))) {
2306                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2307                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2308                show_submodule_summary(o->file, one->path ? one->path : two->path,
2309                                line_prefix,
2310                                &one->oid, &two->oid,
2311                                two->dirty_submodule,
2312                                meta, del, add, reset);
2313                return;
2314        }
2315
2316        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2317                textconv_one = get_textconv(one);
2318                textconv_two = get_textconv(two);
2319        }
2320
2321        diff_set_mnemonic_prefix(o, "a/", "b/");
2322        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2323                a_prefix = o->b_prefix;
2324                b_prefix = o->a_prefix;
2325        } else {
2326                a_prefix = o->a_prefix;
2327                b_prefix = o->b_prefix;
2328        }
2329
2330        /* Never use a non-valid filename anywhere if at all possible */
2331        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2332        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2333
2334        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2335        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2336        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2337        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2338        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2339        if (lbl[0][0] == '/') {
2340                /* /dev/null */
2341                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2342                if (xfrm_msg)
2343                        strbuf_addstr(&header, xfrm_msg);
2344                must_show_header = 1;
2345        }
2346        else if (lbl[1][0] == '/') {
2347                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2348                if (xfrm_msg)
2349                        strbuf_addstr(&header, xfrm_msg);
2350                must_show_header = 1;
2351        }
2352        else {
2353                if (one->mode != two->mode) {
2354                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2355                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2356                        must_show_header = 1;
2357                }
2358                if (xfrm_msg)
2359                        strbuf_addstr(&header, xfrm_msg);
2360
2361                /*
2362                 * we do not run diff between different kind
2363                 * of objects.
2364                 */
2365                if ((one->mode ^ two->mode) & S_IFMT)
2366                        goto free_ab_and_return;
2367                if (complete_rewrite &&
2368                    (textconv_one || !diff_filespec_is_binary(one)) &&
2369                    (textconv_two || !diff_filespec_is_binary(two))) {
2370                        fprintf(o->file, "%s", header.buf);
2371                        strbuf_reset(&header);
2372                        emit_rewrite_diff(name_a, name_b, one, two,
2373                                                textconv_one, textconv_two, o);
2374                        o->found_changes = 1;
2375                        goto free_ab_and_return;
2376                }
2377        }
2378
2379        if (o->irreversible_delete && lbl[1][0] == '/') {
2380                fprintf(o->file, "%s", header.buf);
2381                strbuf_reset(&header);
2382                goto free_ab_and_return;
2383        } else if (!DIFF_OPT_TST(o, TEXT) &&
2384            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2385              (!textconv_two && diff_filespec_is_binary(two)) )) {
2386                if (!one->data && !two->data &&
2387                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2388                    !DIFF_OPT_TST(o, BINARY)) {
2389                        if (!oidcmp(&one->oid, &two->oid)) {
2390                                if (must_show_header)
2391                                        fprintf(o->file, "%s", header.buf);
2392                                goto free_ab_and_return;
2393                        }
2394                        fprintf(o->file, "%s", header.buf);
2395                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2396                                line_prefix, lbl[0], lbl[1]);
2397                        goto free_ab_and_return;
2398                }
2399                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2400                        die("unable to read files to diff");
2401                /* Quite common confusing case */
2402                if (mf1.size == mf2.size &&
2403                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2404                        if (must_show_header)
2405                                fprintf(o->file, "%s", header.buf);
2406                        goto free_ab_and_return;
2407                }
2408                fprintf(o->file, "%s", header.buf);
2409                strbuf_reset(&header);
2410                if (DIFF_OPT_TST(o, BINARY))
2411                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2412                else
2413                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2414                                line_prefix, lbl[0], lbl[1]);
2415                o->found_changes = 1;
2416        } else {
2417                /* Crazy xdl interfaces.. */
2418                const char *diffopts = getenv("GIT_DIFF_OPTS");
2419                const char *v;
2420                xpparam_t xpp;
2421                xdemitconf_t xecfg;
2422                struct emit_callback ecbdata;
2423                const struct userdiff_funcname *pe;
2424
2425                if (must_show_header) {
2426                        fprintf(o->file, "%s", header.buf);
2427                        strbuf_reset(&header);
2428                }
2429
2430                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2431                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2432
2433                pe = diff_funcname_pattern(one);
2434                if (!pe)
2435                        pe = diff_funcname_pattern(two);
2436
2437                memset(&xpp, 0, sizeof(xpp));
2438                memset(&xecfg, 0, sizeof(xecfg));
2439                memset(&ecbdata, 0, sizeof(ecbdata));
2440                ecbdata.label_path = lbl;
2441                ecbdata.color_diff = want_color(o->use_color);
2442                ecbdata.found_changesp = &o->found_changes;
2443                ecbdata.ws_rule = whitespace_rule(name_b);
2444                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2445                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2446                ecbdata.opt = o;
2447                ecbdata.header = header.len ? &header : NULL;
2448                xpp.flags = o->xdl_opts;
2449                xecfg.ctxlen = o->context;
2450                xecfg.interhunkctxlen = o->interhunkcontext;
2451                xecfg.flags = XDL_EMIT_FUNCNAMES;
2452                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2453                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2454                if (pe)
2455                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2456                if (!diffopts)
2457                        ;
2458                else if (skip_prefix(diffopts, "--unified=", &v))
2459                        xecfg.ctxlen = strtoul(v, NULL, 10);
2460                else if (skip_prefix(diffopts, "-u", &v))
2461                        xecfg.ctxlen = strtoul(v, NULL, 10);
2462                if (o->word_diff)
2463                        init_diff_words_data(&ecbdata, o, one, two);
2464                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2465                                  &xpp, &xecfg))
2466                        die("unable to generate diff for %s", one->path);
2467                if (o->word_diff)
2468                        free_diff_words_data(&ecbdata);
2469                if (textconv_one)
2470                        free(mf1.ptr);
2471                if (textconv_two)
2472                        free(mf2.ptr);
2473                xdiff_clear_find_func(&xecfg);
2474        }
2475
2476 free_ab_and_return:
2477        strbuf_release(&header);
2478        diff_free_filespec_data(one);
2479        diff_free_filespec_data(two);
2480        free(a_one);
2481        free(b_two);
2482        return;
2483}
2484
2485static void builtin_diffstat(const char *name_a, const char *name_b,
2486                             struct diff_filespec *one,
2487                             struct diff_filespec *two,
2488                             struct diffstat_t *diffstat,
2489                             struct diff_options *o,
2490                             struct diff_filepair *p)
2491{
2492        mmfile_t mf1, mf2;
2493        struct diffstat_file *data;
2494        int same_contents;
2495        int complete_rewrite = 0;
2496
2497        if (!DIFF_PAIR_UNMERGED(p)) {
2498                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2499                        complete_rewrite = 1;
2500        }
2501
2502        data = diffstat_add(diffstat, name_a, name_b);
2503        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2504
2505        if (!one || !two) {
2506                data->is_unmerged = 1;
2507                return;
2508        }
2509
2510        same_contents = !oidcmp(&one->oid, &two->oid);
2511
2512        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2513                data->is_binary = 1;
2514                if (same_contents) {
2515                        data->added = 0;
2516                        data->deleted = 0;
2517                } else {
2518                        data->added = diff_filespec_size(two);
2519                        data->deleted = diff_filespec_size(one);
2520                }
2521        }
2522
2523        else if (complete_rewrite) {
2524                diff_populate_filespec(one, 0);
2525                diff_populate_filespec(two, 0);
2526                data->deleted = count_lines(one->data, one->size);
2527                data->added = count_lines(two->data, two->size);
2528        }
2529
2530        else if (!same_contents) {
2531                /* Crazy xdl interfaces.. */
2532                xpparam_t xpp;
2533                xdemitconf_t xecfg;
2534
2535                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2536                        die("unable to read files to diff");
2537
2538                memset(&xpp, 0, sizeof(xpp));
2539                memset(&xecfg, 0, sizeof(xecfg));
2540                xpp.flags = o->xdl_opts;
2541                xecfg.ctxlen = o->context;
2542                xecfg.interhunkctxlen = o->interhunkcontext;
2543                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2544                                  &xpp, &xecfg))
2545                        die("unable to generate diffstat for %s", one->path);
2546        }
2547
2548        diff_free_filespec_data(one);
2549        diff_free_filespec_data(two);
2550}
2551
2552static void builtin_checkdiff(const char *name_a, const char *name_b,
2553                              const char *attr_path,
2554                              struct diff_filespec *one,
2555                              struct diff_filespec *two,
2556                              struct diff_options *o)
2557{
2558        mmfile_t mf1, mf2;
2559        struct checkdiff_t data;
2560
2561        if (!two)
2562                return;
2563
2564        memset(&data, 0, sizeof(data));
2565        data.filename = name_b ? name_b : name_a;
2566        data.lineno = 0;
2567        data.o = o;
2568        data.ws_rule = whitespace_rule(attr_path);
2569        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2570
2571        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2572                die("unable to read files to diff");
2573
2574        /*
2575         * All the other codepaths check both sides, but not checking
2576         * the "old" side here is deliberate.  We are checking the newly
2577         * introduced changes, and as long as the "new" side is text, we
2578         * can and should check what it introduces.
2579         */
2580        if (diff_filespec_is_binary(two))
2581                goto free_and_return;
2582        else {
2583                /* Crazy xdl interfaces.. */
2584                xpparam_t xpp;
2585                xdemitconf_t xecfg;
2586
2587                memset(&xpp, 0, sizeof(xpp));
2588                memset(&xecfg, 0, sizeof(xecfg));
2589                xecfg.ctxlen = 1; /* at least one context line */
2590                xpp.flags = 0;
2591                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2592                                  &xpp, &xecfg))
2593                        die("unable to generate checkdiff for %s", one->path);
2594
2595                if (data.ws_rule & WS_BLANK_AT_EOF) {
2596                        struct emit_callback ecbdata;
2597                        int blank_at_eof;
2598
2599                        ecbdata.ws_rule = data.ws_rule;
2600                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2601                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2602
2603                        if (blank_at_eof) {
2604                                static char *err;
2605                                if (!err)
2606                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2607                                fprintf(o->file, "%s:%d: %s.\n",
2608                                        data.filename, blank_at_eof, err);
2609                                data.status = 1; /* report errors */
2610                        }
2611                }
2612        }
2613 free_and_return:
2614        diff_free_filespec_data(one);
2615        diff_free_filespec_data(two);
2616        if (data.status)
2617                DIFF_OPT_SET(o, CHECK_FAILED);
2618}
2619
2620struct diff_filespec *alloc_filespec(const char *path)
2621{
2622        struct diff_filespec *spec;
2623
2624        FLEXPTR_ALLOC_STR(spec, path, path);
2625        spec->count = 1;
2626        spec->is_binary = -1;
2627        return spec;
2628}
2629
2630void free_filespec(struct diff_filespec *spec)
2631{
2632        if (!--spec->count) {
2633                diff_free_filespec_data(spec);
2634                free(spec);
2635        }
2636}
2637
2638void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2639                   int sha1_valid, unsigned short mode)
2640{
2641        if (mode) {
2642                spec->mode = canon_mode(mode);
2643                hashcpy(spec->oid.hash, sha1);
2644                spec->oid_valid = sha1_valid;
2645        }
2646}
2647
2648/*
2649 * Given a name and sha1 pair, if the index tells us the file in
2650 * the work tree has that object contents, return true, so that
2651 * prepare_temp_file() does not have to inflate and extract.
2652 */
2653static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2654{
2655        const struct cache_entry *ce;
2656        struct stat st;
2657        int pos, len;
2658
2659        /*
2660         * We do not read the cache ourselves here, because the
2661         * benchmark with my previous version that always reads cache
2662         * shows that it makes things worse for diff-tree comparing
2663         * two linux-2.6 kernel trees in an already checked out work
2664         * tree.  This is because most diff-tree comparisons deal with
2665         * only a small number of files, while reading the cache is
2666         * expensive for a large project, and its cost outweighs the
2667         * savings we get by not inflating the object to a temporary
2668         * file.  Practically, this code only helps when we are used
2669         * by diff-cache --cached, which does read the cache before
2670         * calling us.
2671         */
2672        if (!active_cache)
2673                return 0;
2674
2675        /* We want to avoid the working directory if our caller
2676         * doesn't need the data in a normal file, this system
2677         * is rather slow with its stat/open/mmap/close syscalls,
2678         * and the object is contained in a pack file.  The pack
2679         * is probably already open and will be faster to obtain
2680         * the data through than the working directory.  Loose
2681         * objects however would tend to be slower as they need
2682         * to be individually opened and inflated.
2683         */
2684        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2685                return 0;
2686
2687        /*
2688         * Similarly, if we'd have to convert the file contents anyway, that
2689         * makes the optimization not worthwhile.
2690         */
2691        if (!want_file && would_convert_to_git(name))
2692                return 0;
2693
2694        len = strlen(name);
2695        pos = cache_name_pos(name, len);
2696        if (pos < 0)
2697                return 0;
2698        ce = active_cache[pos];
2699
2700        /*
2701         * This is not the sha1 we are looking for, or
2702         * unreusable because it is not a regular file.
2703         */
2704        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2705                return 0;
2706
2707        /*
2708         * If ce is marked as "assume unchanged", there is no
2709         * guarantee that work tree matches what we are looking for.
2710         */
2711        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2712                return 0;
2713
2714        /*
2715         * If ce matches the file in the work tree, we can reuse it.
2716         */
2717        if (ce_uptodate(ce) ||
2718            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2719                return 1;
2720
2721        return 0;
2722}
2723
2724static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2725{
2726        struct strbuf buf = STRBUF_INIT;
2727        char *dirty = "";
2728
2729        /* Are we looking at the work tree? */
2730        if (s->dirty_submodule)
2731                dirty = "-dirty";
2732
2733        strbuf_addf(&buf, "Subproject commit %s%s\n",
2734                    oid_to_hex(&s->oid), dirty);
2735        s->size = buf.len;
2736        if (size_only) {
2737                s->data = NULL;
2738                strbuf_release(&buf);
2739        } else {
2740                s->data = strbuf_detach(&buf, NULL);
2741                s->should_free = 1;
2742        }
2743        return 0;
2744}
2745
2746/*
2747 * While doing rename detection and pickaxe operation, we may need to
2748 * grab the data for the blob (or file) for our own in-core comparison.
2749 * diff_filespec has data and size fields for this purpose.
2750 */
2751int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2752{
2753        int size_only = flags & CHECK_SIZE_ONLY;
2754        int err = 0;
2755        /*
2756         * demote FAIL to WARN to allow inspecting the situation
2757         * instead of refusing.
2758         */
2759        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2760                                    ? SAFE_CRLF_WARN
2761                                    : safe_crlf);
2762
2763        if (!DIFF_FILE_VALID(s))
2764                die("internal error: asking to populate invalid file.");
2765        if (S_ISDIR(s->mode))
2766                return -1;
2767
2768        if (s->data)
2769                return 0;
2770
2771        if (size_only && 0 < s->size)
2772                return 0;
2773
2774        if (S_ISGITLINK(s->mode))
2775                return diff_populate_gitlink(s, size_only);
2776
2777        if (!s->oid_valid ||
2778            reuse_worktree_file(s->path, s->oid.hash, 0)) {
2779                struct strbuf buf = STRBUF_INIT;
2780                struct stat st;
2781                int fd;
2782
2783                if (lstat(s->path, &st) < 0) {
2784                        if (errno == ENOENT) {
2785                        err_empty:
2786                                err = -1;
2787                        empty:
2788                                s->data = (char *)"";
2789                                s->size = 0;
2790                                return err;
2791                        }
2792                }
2793                s->size = xsize_t(st.st_size);
2794                if (!s->size)
2795                        goto empty;
2796                if (S_ISLNK(st.st_mode)) {
2797                        struct strbuf sb = STRBUF_INIT;
2798
2799                        if (strbuf_readlink(&sb, s->path, s->size))
2800                                goto err_empty;
2801                        s->size = sb.len;
2802                        s->data = strbuf_detach(&sb, NULL);
2803                        s->should_free = 1;
2804                        return 0;
2805                }
2806                if (size_only)
2807                        return 0;
2808                if ((flags & CHECK_BINARY) &&
2809                    s->size > big_file_threshold && s->is_binary == -1) {
2810                        s->is_binary = 1;
2811                        return 0;
2812                }
2813                fd = open(s->path, O_RDONLY);
2814                if (fd < 0)
2815                        goto err_empty;
2816                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2817                close(fd);
2818                s->should_munmap = 1;
2819
2820                /*
2821                 * Convert from working tree format to canonical git format
2822                 */
2823                if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
2824                        size_t size = 0;
2825                        munmap(s->data, s->size);
2826                        s->should_munmap = 0;
2827                        s->data = strbuf_detach(&buf, &size);
2828                        s->size = size;
2829                        s->should_free = 1;
2830                }
2831        }
2832        else {
2833                enum object_type type;
2834                if (size_only || (flags & CHECK_BINARY)) {
2835                        type = sha1_object_info(s->oid.hash, &s->size);
2836                        if (type < 0)
2837                                die("unable to read %s",
2838                                    oid_to_hex(&s->oid));
2839                        if (size_only)
2840                                return 0;
2841                        if (s->size > big_file_threshold && s->is_binary == -1) {
2842                                s->is_binary = 1;
2843                                return 0;
2844                        }
2845                }
2846                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
2847                if (!s->data)
2848                        die("unable to read %s", oid_to_hex(&s->oid));
2849                s->should_free = 1;
2850        }
2851        return 0;
2852}
2853
2854void diff_free_filespec_blob(struct diff_filespec *s)
2855{
2856        if (s->should_free)
2857                free(s->data);
2858        else if (s->should_munmap)
2859                munmap(s->data, s->size);
2860
2861        if (s->should_free || s->should_munmap) {
2862                s->should_free = s->should_munmap = 0;
2863                s->data = NULL;
2864        }
2865}
2866
2867void diff_free_filespec_data(struct diff_filespec *s)
2868{
2869        diff_free_filespec_blob(s);
2870        free(s->cnt_data);
2871        s->cnt_data = NULL;
2872}
2873
2874static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2875                           void *blob,
2876                           unsigned long size,
2877                           const struct object_id *oid,
2878                           int mode)
2879{
2880        int fd;
2881        struct strbuf buf = STRBUF_INIT;
2882        struct strbuf template = STRBUF_INIT;
2883        char *path_dup = xstrdup(path);
2884        const char *base = basename(path_dup);
2885
2886        /* Generate "XXXXXX_basename.ext" */
2887        strbuf_addstr(&template, "XXXXXX_");
2888        strbuf_addstr(&template, base);
2889
2890        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
2891        if (fd < 0)
2892                die_errno("unable to create temp-file");
2893        if (convert_to_working_tree(path,
2894                        (const char *)blob, (size_t)size, &buf)) {
2895                blob = buf.buf;
2896                size = buf.len;
2897        }
2898        if (write_in_full(fd, blob, size) != size)
2899                die_errno("unable to write temp-file");
2900        close_tempfile(&temp->tempfile);
2901        temp->name = get_tempfile_path(&temp->tempfile);
2902        oid_to_hex_r(temp->hex, oid);
2903        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
2904        strbuf_release(&buf);
2905        strbuf_release(&template);
2906        free(path_dup);
2907}
2908
2909static struct diff_tempfile *prepare_temp_file(const char *name,
2910                struct diff_filespec *one)
2911{
2912        struct diff_tempfile *temp = claim_diff_tempfile();
2913
2914        if (!DIFF_FILE_VALID(one)) {
2915        not_a_valid_file:
2916                /* A '-' entry produces this for file-2, and
2917                 * a '+' entry produces this for file-1.
2918                 */
2919                temp->name = "/dev/null";
2920                xsnprintf(temp->hex, sizeof(temp->hex), ".");
2921                xsnprintf(temp->mode, sizeof(temp->mode), ".");
2922                return temp;
2923        }
2924
2925        if (!S_ISGITLINK(one->mode) &&
2926            (!one->oid_valid ||
2927             reuse_worktree_file(name, one->oid.hash, 1))) {
2928                struct stat st;
2929                if (lstat(name, &st) < 0) {
2930                        if (errno == ENOENT)
2931                                goto not_a_valid_file;
2932                        die_errno("stat(%s)", name);
2933                }
2934                if (S_ISLNK(st.st_mode)) {
2935                        struct strbuf sb = STRBUF_INIT;
2936                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2937                                die_errno("readlink(%s)", name);
2938                        prep_temp_blob(name, temp, sb.buf, sb.len,
2939                                       (one->oid_valid ?
2940                                        &one->oid : &null_oid),
2941                                       (one->oid_valid ?
2942                                        one->mode : S_IFLNK));
2943                        strbuf_release(&sb);
2944                }
2945                else {
2946                        /* we can borrow from the file in the work tree */
2947                        temp->name = name;
2948                        if (!one->oid_valid)
2949                                sha1_to_hex_r(temp->hex, null_sha1);
2950                        else
2951                                sha1_to_hex_r(temp->hex, one->oid.hash);
2952                        /* Even though we may sometimes borrow the
2953                         * contents from the work tree, we always want
2954                         * one->mode.  mode is trustworthy even when
2955                         * !(one->sha1_valid), as long as
2956                         * DIFF_FILE_VALID(one).
2957                         */
2958                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
2959                }
2960                return temp;
2961        }
2962        else {
2963                if (diff_populate_filespec(one, 0))
2964                        die("cannot read data blob for %s", one->path);
2965                prep_temp_blob(name, temp, one->data, one->size,
2966                               &one->oid, one->mode);
2967        }
2968        return temp;
2969}
2970
2971static void add_external_diff_name(struct argv_array *argv,
2972                                   const char *name,
2973                                   struct diff_filespec *df)
2974{
2975        struct diff_tempfile *temp = prepare_temp_file(name, df);
2976        argv_array_push(argv, temp->name);
2977        argv_array_push(argv, temp->hex);
2978        argv_array_push(argv, temp->mode);
2979}
2980
2981/* An external diff command takes:
2982 *
2983 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2984 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2985 *
2986 */
2987static void run_external_diff(const char *pgm,
2988                              const char *name,
2989                              const char *other,
2990                              struct diff_filespec *one,
2991                              struct diff_filespec *two,
2992                              const char *xfrm_msg,
2993                              int complete_rewrite,
2994                              struct diff_options *o)
2995{
2996        struct argv_array argv = ARGV_ARRAY_INIT;
2997        struct argv_array env = ARGV_ARRAY_INIT;
2998        struct diff_queue_struct *q = &diff_queued_diff;
2999
3000        argv_array_push(&argv, pgm);
3001        argv_array_push(&argv, name);
3002
3003        if (one && two) {
3004                add_external_diff_name(&argv, name, one);
3005                if (!other)
3006                        add_external_diff_name(&argv, name, two);
3007                else {
3008                        add_external_diff_name(&argv, other, two);
3009                        argv_array_push(&argv, other);
3010                        argv_array_push(&argv, xfrm_msg);
3011                }
3012        }
3013
3014        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3015        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3016
3017        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3018                die(_("external diff died, stopping at %s"), name);
3019
3020        remove_tempfile();
3021        argv_array_clear(&argv);
3022        argv_array_clear(&env);
3023}
3024
3025static int similarity_index(struct diff_filepair *p)
3026{
3027        return p->score * 100 / MAX_SCORE;
3028}
3029
3030static void fill_metainfo(struct strbuf *msg,
3031                          const char *name,
3032                          const char *other,
3033                          struct diff_filespec *one,
3034                          struct diff_filespec *two,
3035                          struct diff_options *o,
3036                          struct diff_filepair *p,
3037                          int *must_show_header,
3038                          int use_color)
3039{
3040        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3041        const char *reset = diff_get_color(use_color, DIFF_RESET);
3042        const char *line_prefix = diff_line_prefix(o);
3043
3044        *must_show_header = 1;
3045        strbuf_init(msg, PATH_MAX * 2 + 300);
3046        switch (p->status) {
3047        case DIFF_STATUS_COPIED:
3048                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3049                            line_prefix, set, similarity_index(p));
3050                strbuf_addf(msg, "%s\n%s%scopy from ",
3051                            reset,  line_prefix, set);
3052                quote_c_style(name, msg, NULL, 0);
3053                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3054                quote_c_style(other, msg, NULL, 0);
3055                strbuf_addf(msg, "%s\n", reset);
3056                break;
3057        case DIFF_STATUS_RENAMED:
3058                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3059                            line_prefix, set, similarity_index(p));
3060                strbuf_addf(msg, "%s\n%s%srename from ",
3061                            reset, line_prefix, set);
3062                quote_c_style(name, msg, NULL, 0);
3063                strbuf_addf(msg, "%s\n%s%srename to ",
3064                            reset, line_prefix, set);
3065                quote_c_style(other, msg, NULL, 0);
3066                strbuf_addf(msg, "%s\n", reset);
3067                break;
3068        case DIFF_STATUS_MODIFIED:
3069                if (p->score) {
3070                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3071                                    line_prefix,
3072                                    set, similarity_index(p), reset);
3073                        break;
3074                }
3075                /* fallthru */
3076        default:
3077                *must_show_header = 0;
3078        }
3079        if (one && two && oidcmp(&one->oid, &two->oid)) {
3080                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3081
3082                if (DIFF_OPT_TST(o, BINARY)) {
3083                        mmfile_t mf;
3084                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3085                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3086                                abbrev = 40;
3087                }
3088                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3089                            find_unique_abbrev(one->oid.hash, abbrev));
3090                strbuf_addstr(msg, find_unique_abbrev(two->oid.hash, abbrev));
3091                if (one->mode == two->mode)
3092                        strbuf_addf(msg, " %06o", one->mode);
3093                strbuf_addf(msg, "%s\n", reset);
3094        }
3095}
3096
3097static void run_diff_cmd(const char *pgm,
3098                         const char *name,
3099                         const char *other,
3100                         const char *attr_path,
3101                         struct diff_filespec *one,
3102                         struct diff_filespec *two,
3103                         struct strbuf *msg,
3104                         struct diff_options *o,
3105                         struct diff_filepair *p)
3106{
3107        const char *xfrm_msg = NULL;
3108        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3109        int must_show_header = 0;
3110
3111
3112        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3113                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3114                if (drv && drv->external)
3115                        pgm = drv->external;
3116        }
3117
3118        if (msg) {
3119                /*
3120                 * don't use colors when the header is intended for an
3121                 * external diff driver
3122                 */
3123                fill_metainfo(msg, name, other, one, two, o, p,
3124                              &must_show_header,
3125                              want_color(o->use_color) && !pgm);
3126                xfrm_msg = msg->len ? msg->buf : NULL;
3127        }
3128
3129        if (pgm) {
3130                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3131                                  complete_rewrite, o);
3132                return;
3133        }
3134        if (one && two)
3135                builtin_diff(name, other ? other : name,
3136                             one, two, xfrm_msg, must_show_header,
3137                             o, complete_rewrite);
3138        else
3139                fprintf(o->file, "* Unmerged path %s\n", name);
3140}
3141
3142static void diff_fill_sha1_info(struct diff_filespec *one)
3143{
3144        if (DIFF_FILE_VALID(one)) {
3145                if (!one->oid_valid) {
3146                        struct stat st;
3147                        if (one->is_stdin) {
3148                                oidclr(&one->oid);
3149                                return;
3150                        }
3151                        if (lstat(one->path, &st) < 0)
3152                                die_errno("stat '%s'", one->path);
3153                        if (index_path(one->oid.hash, one->path, &st, 0))
3154                                die("cannot hash %s", one->path);
3155                }
3156        }
3157        else
3158                oidclr(&one->oid);
3159}
3160
3161static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3162{
3163        /* Strip the prefix but do not molest /dev/null and absolute paths */
3164        if (*namep && **namep != '/') {
3165                *namep += prefix_length;
3166                if (**namep == '/')
3167                        ++*namep;
3168        }
3169        if (*otherp && **otherp != '/') {
3170                *otherp += prefix_length;
3171                if (**otherp == '/')
3172                        ++*otherp;
3173        }
3174}
3175
3176static void run_diff(struct diff_filepair *p, struct diff_options *o)
3177{
3178        const char *pgm = external_diff();
3179        struct strbuf msg;
3180        struct diff_filespec *one = p->one;
3181        struct diff_filespec *two = p->two;
3182        const char *name;
3183        const char *other;
3184        const char *attr_path;
3185
3186        name  = p->one->path;
3187        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3188        attr_path = name;
3189        if (o->prefix_length)
3190                strip_prefix(o->prefix_length, &name, &other);
3191
3192        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3193                pgm = NULL;
3194
3195        if (DIFF_PAIR_UNMERGED(p)) {
3196                run_diff_cmd(pgm, name, NULL, attr_path,
3197                             NULL, NULL, NULL, o, p);
3198                return;
3199        }
3200
3201        diff_fill_sha1_info(one);
3202        diff_fill_sha1_info(two);
3203
3204        if (!pgm &&
3205            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3206            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3207                /*
3208                 * a filepair that changes between file and symlink
3209                 * needs to be split into deletion and creation.
3210                 */
3211                struct diff_filespec *null = alloc_filespec(two->path);
3212                run_diff_cmd(NULL, name, other, attr_path,
3213                             one, null, &msg, o, p);
3214                free(null);
3215                strbuf_release(&msg);
3216
3217                null = alloc_filespec(one->path);
3218                run_diff_cmd(NULL, name, other, attr_path,
3219                             null, two, &msg, o, p);
3220                free(null);
3221        }
3222        else
3223                run_diff_cmd(pgm, name, other, attr_path,
3224                             one, two, &msg, o, p);
3225
3226        strbuf_release(&msg);
3227}
3228
3229static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3230                         struct diffstat_t *diffstat)
3231{
3232        const char *name;
3233        const char *other;
3234
3235        if (DIFF_PAIR_UNMERGED(p)) {
3236                /* unmerged */
3237                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3238                return;
3239        }
3240
3241        name = p->one->path;
3242        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3243
3244        if (o->prefix_length)
3245                strip_prefix(o->prefix_length, &name, &other);
3246
3247        diff_fill_sha1_info(p->one);
3248        diff_fill_sha1_info(p->two);
3249
3250        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3251}
3252
3253static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3254{
3255        const char *name;
3256        const char *other;
3257        const char *attr_path;
3258
3259        if (DIFF_PAIR_UNMERGED(p)) {
3260                /* unmerged */
3261                return;
3262        }
3263
3264        name = p->one->path;
3265        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3266        attr_path = other ? other : name;
3267
3268        if (o->prefix_length)
3269                strip_prefix(o->prefix_length, &name, &other);
3270
3271        diff_fill_sha1_info(p->one);
3272        diff_fill_sha1_info(p->two);
3273
3274        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3275}
3276
3277void diff_setup(struct diff_options *options)
3278{
3279        memcpy(options, &default_diff_options, sizeof(*options));
3280
3281        options->file = stdout;
3282
3283        options->line_termination = '\n';
3284        options->break_opt = -1;
3285        options->rename_limit = -1;
3286        options->dirstat_permille = diff_dirstat_permille_default;
3287        options->context = diff_context_default;
3288        options->ws_error_highlight = WSEH_NEW;
3289        DIFF_OPT_SET(options, RENAME_EMPTY);
3290
3291        /* pathchange left =NULL by default */
3292        options->change = diff_change;
3293        options->add_remove = diff_addremove;
3294        options->use_color = diff_use_color_default;
3295        options->detect_rename = diff_detect_rename_default;
3296        options->xdl_opts |= diff_algorithm;
3297        if (diff_compaction_heuristic)
3298                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3299
3300        options->orderfile = diff_order_file_cfg;
3301
3302        if (diff_no_prefix) {
3303                options->a_prefix = options->b_prefix = "";
3304        } else if (!diff_mnemonic_prefix) {
3305                options->a_prefix = "a/";
3306                options->b_prefix = "b/";
3307        }
3308}
3309
3310void diff_setup_done(struct diff_options *options)
3311{
3312        int count = 0;
3313
3314        if (options->set_default)
3315                options->set_default(options);
3316
3317        if (options->output_format & DIFF_FORMAT_NAME)
3318                count++;
3319        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3320                count++;
3321        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3322                count++;
3323        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3324                count++;
3325        if (count > 1)
3326                die("--name-only, --name-status, --check and -s are mutually exclusive");
3327
3328        /*
3329         * Most of the time we can say "there are changes"
3330         * only by checking if there are changed paths, but
3331         * --ignore-whitespace* options force us to look
3332         * inside contents.
3333         */
3334
3335        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3336            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3337            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3338                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3339        else
3340                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3341
3342        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3343                options->detect_rename = DIFF_DETECT_COPY;
3344
3345        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3346                options->prefix = NULL;
3347        if (options->prefix)
3348                options->prefix_length = strlen(options->prefix);
3349        else
3350                options->prefix_length = 0;
3351
3352        if (options->output_format & (DIFF_FORMAT_NAME |
3353                                      DIFF_FORMAT_NAME_STATUS |
3354                                      DIFF_FORMAT_CHECKDIFF |
3355                                      DIFF_FORMAT_NO_OUTPUT))
3356                options->output_format &= ~(DIFF_FORMAT_RAW |
3357                                            DIFF_FORMAT_NUMSTAT |
3358                                            DIFF_FORMAT_DIFFSTAT |
3359                                            DIFF_FORMAT_SHORTSTAT |
3360                                            DIFF_FORMAT_DIRSTAT |
3361                                            DIFF_FORMAT_SUMMARY |
3362                                            DIFF_FORMAT_PATCH);
3363
3364        /*
3365         * These cases always need recursive; we do not drop caller-supplied
3366         * recursive bits for other formats here.
3367         */
3368        if (options->output_format & (DIFF_FORMAT_PATCH |
3369                                      DIFF_FORMAT_NUMSTAT |
3370                                      DIFF_FORMAT_DIFFSTAT |
3371                                      DIFF_FORMAT_SHORTSTAT |
3372                                      DIFF_FORMAT_DIRSTAT |
3373                                      DIFF_FORMAT_SUMMARY |
3374                                      DIFF_FORMAT_CHECKDIFF))
3375                DIFF_OPT_SET(options, RECURSIVE);
3376        /*
3377         * Also pickaxe would not work very well if you do not say recursive
3378         */
3379        if (options->pickaxe)
3380                DIFF_OPT_SET(options, RECURSIVE);
3381        /*
3382         * When patches are generated, submodules diffed against the work tree
3383         * must be checked for dirtiness too so it can be shown in the output
3384         */
3385        if (options->output_format & DIFF_FORMAT_PATCH)
3386                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3387
3388        if (options->detect_rename && options->rename_limit < 0)
3389                options->rename_limit = diff_rename_limit_default;
3390        if (options->setup & DIFF_SETUP_USE_CACHE) {
3391                if (!active_cache)
3392                        /* read-cache does not die even when it fails
3393                         * so it is safe for us to do this here.  Also
3394                         * it does not smudge active_cache or active_nr
3395                         * when it fails, so we do not have to worry about
3396                         * cleaning it up ourselves either.
3397                         */
3398                        read_cache();
3399        }
3400        if (options->abbrev <= 0 || 40 < options->abbrev)
3401                options->abbrev = 40; /* full */
3402
3403        /*
3404         * It does not make sense to show the first hit we happened
3405         * to have found.  It does not make sense not to return with
3406         * exit code in such a case either.
3407         */
3408        if (DIFF_OPT_TST(options, QUICK)) {
3409                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3410                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3411        }
3412
3413        options->diff_path_counter = 0;
3414
3415        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3416                die(_("--follow requires exactly one pathspec"));
3417}
3418
3419static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3420{
3421        char c, *eq;
3422        int len;
3423
3424        if (*arg != '-')
3425                return 0;
3426        c = *++arg;
3427        if (!c)
3428                return 0;
3429        if (c == arg_short) {
3430                c = *++arg;
3431                if (!c)
3432                        return 1;
3433                if (val && isdigit(c)) {
3434                        char *end;
3435                        int n = strtoul(arg, &end, 10);
3436                        if (*end)
3437                                return 0;
3438                        *val = n;
3439                        return 1;
3440                }
3441                return 0;
3442        }
3443        if (c != '-')
3444                return 0;
3445        arg++;
3446        eq = strchrnul(arg, '=');
3447        len = eq - arg;
3448        if (!len || strncmp(arg, arg_long, len))
3449                return 0;
3450        if (*eq) {
3451                int n;
3452                char *end;
3453                if (!isdigit(*++eq))
3454                        return 0;
3455                n = strtoul(eq, &end, 10);
3456                if (*end)
3457                        return 0;
3458                *val = n;
3459        }
3460        return 1;
3461}
3462
3463static int diff_scoreopt_parse(const char *opt);
3464
3465static inline int short_opt(char opt, const char **argv,
3466                            const char **optarg)
3467{
3468        const char *arg = argv[0];
3469        if (arg[0] != '-' || arg[1] != opt)
3470                return 0;
3471        if (arg[2] != '\0') {
3472                *optarg = arg + 2;
3473                return 1;
3474        }
3475        if (!argv[1])
3476                die("Option '%c' requires a value", opt);
3477        *optarg = argv[1];
3478        return 2;
3479}
3480
3481int parse_long_opt(const char *opt, const char **argv,
3482                   const char **optarg)
3483{
3484        const char *arg = argv[0];
3485        if (!skip_prefix(arg, "--", &arg))
3486                return 0;
3487        if (!skip_prefix(arg, opt, &arg))
3488                return 0;
3489        if (*arg == '=') { /* stuck form: --option=value */
3490                *optarg = arg + 1;
3491                return 1;
3492        }
3493        if (*arg != '\0')
3494                return 0;
3495        /* separate form: --option value */
3496        if (!argv[1])
3497                die("Option '--%s' requires a value", opt);
3498        *optarg = argv[1];
3499        return 2;
3500}
3501
3502static int stat_opt(struct diff_options *options, const char **av)
3503{
3504        const char *arg = av[0];
3505        char *end;
3506        int width = options->stat_width;
3507        int name_width = options->stat_name_width;
3508        int graph_width = options->stat_graph_width;
3509        int count = options->stat_count;
3510        int argcount = 1;
3511
3512        if (!skip_prefix(arg, "--stat", &arg))
3513                die("BUG: stat option does not begin with --stat: %s", arg);
3514        end = (char *)arg;
3515
3516        switch (*arg) {
3517        case '-':
3518                if (skip_prefix(arg, "-width", &arg)) {
3519                        if (*arg == '=')
3520                                width = strtoul(arg + 1, &end, 10);
3521                        else if (!*arg && !av[1])
3522                                die("Option '--stat-width' requires a value");
3523                        else if (!*arg) {
3524                                width = strtoul(av[1], &end, 10);
3525                                argcount = 2;
3526                        }
3527                } else if (skip_prefix(arg, "-name-width", &arg)) {
3528                        if (*arg == '=')
3529                                name_width = strtoul(arg + 1, &end, 10);
3530                        else if (!*arg && !av[1])
3531                                die("Option '--stat-name-width' requires a value");
3532                        else if (!*arg) {
3533                                name_width = strtoul(av[1], &end, 10);
3534                                argcount = 2;
3535                        }
3536                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3537                        if (*arg == '=')
3538                                graph_width = strtoul(arg + 1, &end, 10);
3539                        else if (!*arg && !av[1])
3540                                die("Option '--stat-graph-width' requires a value");
3541                        else if (!*arg) {
3542                                graph_width = strtoul(av[1], &end, 10);
3543                                argcount = 2;
3544                        }
3545                } else if (skip_prefix(arg, "-count", &arg)) {
3546                        if (*arg == '=')
3547                                count = strtoul(arg + 1, &end, 10);
3548                        else if (!*arg && !av[1])
3549                                die("Option '--stat-count' requires a value");
3550                        else if (!*arg) {
3551                                count = strtoul(av[1], &end, 10);
3552                                argcount = 2;
3553                        }
3554                }
3555                break;
3556        case '=':
3557                width = strtoul(arg+1, &end, 10);
3558                if (*end == ',')
3559                        name_width = strtoul(end+1, &end, 10);
3560                if (*end == ',')
3561                        count = strtoul(end+1, &end, 10);
3562        }
3563
3564        /* Important! This checks all the error cases! */
3565        if (*end)
3566                return 0;
3567        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3568        options->stat_name_width = name_width;
3569        options->stat_graph_width = graph_width;
3570        options->stat_width = width;
3571        options->stat_count = count;
3572        return argcount;
3573}
3574
3575static int parse_dirstat_opt(struct diff_options *options, const char *params)
3576{
3577        struct strbuf errmsg = STRBUF_INIT;
3578        if (parse_dirstat_params(options, params, &errmsg))
3579                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3580                    errmsg.buf);
3581        strbuf_release(&errmsg);
3582        /*
3583         * The caller knows a dirstat-related option is given from the command
3584         * line; allow it to say "return this_function();"
3585         */
3586        options->output_format |= DIFF_FORMAT_DIRSTAT;
3587        return 1;
3588}
3589
3590static int parse_submodule_opt(struct diff_options *options, const char *value)
3591{
3592        if (parse_submodule_params(options, value))
3593                die(_("Failed to parse --submodule option parameter: '%s'"),
3594                        value);
3595        return 1;
3596}
3597
3598static const char diff_status_letters[] = {
3599        DIFF_STATUS_ADDED,
3600        DIFF_STATUS_COPIED,
3601        DIFF_STATUS_DELETED,
3602        DIFF_STATUS_MODIFIED,
3603        DIFF_STATUS_RENAMED,
3604        DIFF_STATUS_TYPE_CHANGED,
3605        DIFF_STATUS_UNKNOWN,
3606        DIFF_STATUS_UNMERGED,
3607        DIFF_STATUS_FILTER_AON,
3608        DIFF_STATUS_FILTER_BROKEN,
3609        '\0',
3610};
3611
3612static unsigned int filter_bit['Z' + 1];
3613
3614static void prepare_filter_bits(void)
3615{
3616        int i;
3617
3618        if (!filter_bit[DIFF_STATUS_ADDED]) {
3619                for (i = 0; diff_status_letters[i]; i++)
3620                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3621        }
3622}
3623
3624static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3625{
3626        return opt->filter & filter_bit[(int) status];
3627}
3628
3629static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3630{
3631        int i, optch;
3632
3633        prepare_filter_bits();
3634
3635        /*
3636         * If there is a negation e.g. 'd' in the input, and we haven't
3637         * initialized the filter field with another --diff-filter, start
3638         * from full set of bits, except for AON.
3639         */
3640        if (!opt->filter) {
3641                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3642                        if (optch < 'a' || 'z' < optch)
3643                                continue;
3644                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3645                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3646                        break;
3647                }
3648        }
3649
3650        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3651                unsigned int bit;
3652                int negate;
3653
3654                if ('a' <= optch && optch <= 'z') {
3655                        negate = 1;
3656                        optch = toupper(optch);
3657                } else {
3658                        negate = 0;
3659                }
3660
3661                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3662                if (!bit)
3663                        return optarg[i];
3664                if (negate)
3665                        opt->filter &= ~bit;
3666                else
3667                        opt->filter |= bit;
3668        }
3669        return 0;
3670}
3671
3672static void enable_patch_output(int *fmt) {
3673        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3674        *fmt |= DIFF_FORMAT_PATCH;
3675}
3676
3677static int parse_one_token(const char **arg, const char *token)
3678{
3679        const char *rest;
3680        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
3681                *arg = rest;
3682                return 1;
3683        }
3684        return 0;
3685}
3686
3687static int parse_ws_error_highlight(struct diff_options *opt, const char *arg)
3688{
3689        const char *orig_arg = arg;
3690        unsigned val = 0;
3691        while (*arg) {
3692                if (parse_one_token(&arg, "none"))
3693                        val = 0;
3694                else if (parse_one_token(&arg, "default"))
3695                        val = WSEH_NEW;
3696                else if (parse_one_token(&arg, "all"))
3697                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
3698                else if (parse_one_token(&arg, "new"))
3699                        val |= WSEH_NEW;
3700                else if (parse_one_token(&arg, "old"))
3701                        val |= WSEH_OLD;
3702                else if (parse_one_token(&arg, "context"))
3703                        val |= WSEH_CONTEXT;
3704                else {
3705                        error("unknown value after ws-error-highlight=%.*s",
3706                              (int)(arg - orig_arg), orig_arg);
3707                        return 0;
3708                }
3709                if (*arg)
3710                        arg++;
3711        }
3712        opt->ws_error_highlight = val;
3713        return 1;
3714}
3715
3716int diff_opt_parse(struct diff_options *options,
3717                   const char **av, int ac, const char *prefix)
3718{
3719        const char *arg = av[0];
3720        const char *optarg;
3721        int argcount;
3722
3723        if (!prefix)
3724                prefix = "";
3725
3726        /* Output format options */
3727        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3728            || opt_arg(arg, 'U', "unified", &options->context))
3729                enable_patch_output(&options->output_format);
3730        else if (!strcmp(arg, "--raw"))
3731                options->output_format |= DIFF_FORMAT_RAW;
3732        else if (!strcmp(arg, "--patch-with-raw")) {
3733                enable_patch_output(&options->output_format);
3734                options->output_format |= DIFF_FORMAT_RAW;
3735        } else if (!strcmp(arg, "--numstat"))
3736                options->output_format |= DIFF_FORMAT_NUMSTAT;
3737        else if (!strcmp(arg, "--shortstat"))
3738                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3739        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3740                return parse_dirstat_opt(options, "");
3741        else if (skip_prefix(arg, "-X", &arg))
3742                return parse_dirstat_opt(options, arg);
3743        else if (skip_prefix(arg, "--dirstat=", &arg))
3744                return parse_dirstat_opt(options, arg);
3745        else if (!strcmp(arg, "--cumulative"))
3746                return parse_dirstat_opt(options, "cumulative");
3747        else if (!strcmp(arg, "--dirstat-by-file"))
3748                return parse_dirstat_opt(options, "files");
3749        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3750                parse_dirstat_opt(options, "files");
3751                return parse_dirstat_opt(options, arg);
3752        }
3753        else if (!strcmp(arg, "--check"))
3754                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3755        else if (!strcmp(arg, "--summary"))
3756                options->output_format |= DIFF_FORMAT_SUMMARY;
3757        else if (!strcmp(arg, "--patch-with-stat")) {
3758                enable_patch_output(&options->output_format);
3759                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3760        } else if (!strcmp(arg, "--name-only"))
3761                options->output_format |= DIFF_FORMAT_NAME;
3762        else if (!strcmp(arg, "--name-status"))
3763                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3764        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3765                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3766        else if (starts_with(arg, "--stat"))
3767                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3768                return stat_opt(options, av);
3769
3770        /* renames options */
3771        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3772                 !strcmp(arg, "--break-rewrites")) {
3773                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3774                        return error("invalid argument to -B: %s", arg+2);
3775        }
3776        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3777                 !strcmp(arg, "--find-renames")) {
3778                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3779                        return error("invalid argument to -M: %s", arg+2);
3780                options->detect_rename = DIFF_DETECT_RENAME;
3781        }
3782        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3783                options->irreversible_delete = 1;
3784        }
3785        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3786                 !strcmp(arg, "--find-copies")) {
3787                if (options->detect_rename == DIFF_DETECT_COPY)
3788                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3789                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3790                        return error("invalid argument to -C: %s", arg+2);
3791                options->detect_rename = DIFF_DETECT_COPY;
3792        }
3793        else if (!strcmp(arg, "--no-renames"))
3794                options->detect_rename = 0;
3795        else if (!strcmp(arg, "--rename-empty"))
3796                DIFF_OPT_SET(options, RENAME_EMPTY);
3797        else if (!strcmp(arg, "--no-rename-empty"))
3798                DIFF_OPT_CLR(options, RENAME_EMPTY);
3799        else if (!strcmp(arg, "--relative"))
3800                DIFF_OPT_SET(options, RELATIVE_NAME);
3801        else if (skip_prefix(arg, "--relative=", &arg)) {
3802                DIFF_OPT_SET(options, RELATIVE_NAME);
3803                options->prefix = arg;
3804        }
3805
3806        /* xdiff options */
3807        else if (!strcmp(arg, "--minimal"))
3808                DIFF_XDL_SET(options, NEED_MINIMAL);
3809        else if (!strcmp(arg, "--no-minimal"))
3810                DIFF_XDL_CLR(options, NEED_MINIMAL);
3811        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3812                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3813        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3814                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3815        else if (!strcmp(arg, "--ignore-space-at-eol"))
3816                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3817        else if (!strcmp(arg, "--ignore-blank-lines"))
3818                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3819        else if (!strcmp(arg, "--compaction-heuristic"))
3820                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3821        else if (!strcmp(arg, "--no-compaction-heuristic"))
3822                DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
3823        else if (!strcmp(arg, "--patience"))
3824                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3825        else if (!strcmp(arg, "--histogram"))
3826                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3827        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3828                long value = parse_algorithm_value(optarg);
3829                if (value < 0)
3830                        return error("option diff-algorithm accepts \"myers\", "
3831                                     "\"minimal\", \"patience\" and \"histogram\"");
3832                /* clear out previous settings */
3833                DIFF_XDL_CLR(options, NEED_MINIMAL);
3834                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3835                options->xdl_opts |= value;
3836                return argcount;
3837        }
3838
3839        /* flags options */
3840        else if (!strcmp(arg, "--binary")) {
3841                enable_patch_output(&options->output_format);
3842                DIFF_OPT_SET(options, BINARY);
3843        }
3844        else if (!strcmp(arg, "--full-index"))
3845                DIFF_OPT_SET(options, FULL_INDEX);
3846        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3847                DIFF_OPT_SET(options, TEXT);
3848        else if (!strcmp(arg, "-R"))
3849                DIFF_OPT_SET(options, REVERSE_DIFF);
3850        else if (!strcmp(arg, "--find-copies-harder"))
3851                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3852        else if (!strcmp(arg, "--follow"))
3853                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3854        else if (!strcmp(arg, "--no-follow")) {
3855                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3856                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
3857        } else if (!strcmp(arg, "--color"))
3858                options->use_color = 1;
3859        else if (skip_prefix(arg, "--color=", &arg)) {
3860                int value = git_config_colorbool(NULL, arg);
3861                if (value < 0)
3862                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3863                options->use_color = value;
3864        }
3865        else if (!strcmp(arg, "--no-color"))
3866                options->use_color = 0;
3867        else if (!strcmp(arg, "--color-words")) {
3868                options->use_color = 1;
3869                options->word_diff = DIFF_WORDS_COLOR;
3870        }
3871        else if (skip_prefix(arg, "--color-words=", &arg)) {
3872                options->use_color = 1;
3873                options->word_diff = DIFF_WORDS_COLOR;
3874                options->word_regex = arg;
3875        }
3876        else if (!strcmp(arg, "--word-diff")) {
3877                if (options->word_diff == DIFF_WORDS_NONE)
3878                        options->word_diff = DIFF_WORDS_PLAIN;
3879        }
3880        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3881                if (!strcmp(arg, "plain"))
3882                        options->word_diff = DIFF_WORDS_PLAIN;
3883                else if (!strcmp(arg, "color")) {
3884                        options->use_color = 1;
3885                        options->word_diff = DIFF_WORDS_COLOR;
3886                }
3887                else if (!strcmp(arg, "porcelain"))
3888                        options->word_diff = DIFF_WORDS_PORCELAIN;
3889                else if (!strcmp(arg, "none"))
3890                        options->word_diff = DIFF_WORDS_NONE;
3891                else
3892                        die("bad --word-diff argument: %s", arg);
3893        }
3894        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3895                if (options->word_diff == DIFF_WORDS_NONE)
3896                        options->word_diff = DIFF_WORDS_PLAIN;
3897                options->word_regex = optarg;
3898                return argcount;
3899        }
3900        else if (!strcmp(arg, "--exit-code"))
3901                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3902        else if (!strcmp(arg, "--quiet"))
3903                DIFF_OPT_SET(options, QUICK);
3904        else if (!strcmp(arg, "--ext-diff"))
3905                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3906        else if (!strcmp(arg, "--no-ext-diff"))
3907                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3908        else if (!strcmp(arg, "--textconv"))
3909                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3910        else if (!strcmp(arg, "--no-textconv"))
3911                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3912        else if (!strcmp(arg, "--ignore-submodules")) {
3913                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3914                handle_ignore_submodules_arg(options, "all");
3915        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
3916                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3917                handle_ignore_submodules_arg(options, arg);
3918        } else if (!strcmp(arg, "--submodule"))
3919                options->submodule_format = DIFF_SUBMODULE_LOG;
3920        else if (skip_prefix(arg, "--submodule=", &arg))
3921                return parse_submodule_opt(options, arg);
3922        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
3923                return parse_ws_error_highlight(options, arg);
3924
3925        /* misc options */
3926        else if (!strcmp(arg, "-z"))
3927                options->line_termination = 0;
3928        else if ((argcount = short_opt('l', av, &optarg))) {
3929                options->rename_limit = strtoul(optarg, NULL, 10);
3930                return argcount;
3931        }
3932        else if ((argcount = short_opt('S', av, &optarg))) {
3933                options->pickaxe = optarg;
3934                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3935                return argcount;
3936        } else if ((argcount = short_opt('G', av, &optarg))) {
3937                options->pickaxe = optarg;
3938                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3939                return argcount;
3940        }
3941        else if (!strcmp(arg, "--pickaxe-all"))
3942                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3943        else if (!strcmp(arg, "--pickaxe-regex"))
3944                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3945        else if ((argcount = short_opt('O', av, &optarg))) {
3946                const char *path = prefix_filename(prefix, strlen(prefix), optarg);
3947                options->orderfile = xstrdup(path);
3948                return argcount;
3949        }
3950        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3951                int offending = parse_diff_filter_opt(optarg, options);
3952                if (offending)
3953                        die("unknown change class '%c' in --diff-filter=%s",
3954                            offending, optarg);
3955                return argcount;
3956        }
3957        else if (!strcmp(arg, "--abbrev"))
3958                options->abbrev = DEFAULT_ABBREV;
3959        else if (skip_prefix(arg, "--abbrev=", &arg)) {
3960                options->abbrev = strtoul(arg, NULL, 10);
3961                if (options->abbrev < MINIMUM_ABBREV)
3962                        options->abbrev = MINIMUM_ABBREV;
3963                else if (40 < options->abbrev)
3964                        options->abbrev = 40;
3965        }
3966        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3967                options->a_prefix = optarg;
3968                return argcount;
3969        }
3970        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
3971                options->line_prefix = optarg;
3972                options->line_prefix_length = strlen(options->line_prefix);
3973                graph_setup_line_prefix(options);
3974                return argcount;
3975        }
3976        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3977                options->b_prefix = optarg;
3978                return argcount;
3979        }
3980        else if (!strcmp(arg, "--no-prefix"))
3981                options->a_prefix = options->b_prefix = "";
3982        else if (opt_arg(arg, '\0', "inter-hunk-context",
3983                         &options->interhunkcontext))
3984                ;
3985        else if (!strcmp(arg, "-W"))
3986                DIFF_OPT_SET(options, FUNCCONTEXT);
3987        else if (!strcmp(arg, "--function-context"))
3988                DIFF_OPT_SET(options, FUNCCONTEXT);
3989        else if (!strcmp(arg, "--no-function-context"))
3990                DIFF_OPT_CLR(options, FUNCCONTEXT);
3991        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3992                const char *path = prefix_filename(prefix, strlen(prefix), optarg);
3993                options->file = fopen(path, "w");
3994                if (!options->file)
3995                        die_errno("Could not open '%s'", path);
3996                options->close_file = 1;
3997                if (options->use_color != GIT_COLOR_ALWAYS)
3998                        options->use_color = GIT_COLOR_NEVER;
3999                return argcount;
4000        } else
4001                return 0;
4002        return 1;
4003}
4004
4005int parse_rename_score(const char **cp_p)
4006{
4007        unsigned long num, scale;
4008        int ch, dot;
4009        const char *cp = *cp_p;
4010
4011        num = 0;
4012        scale = 1;
4013        dot = 0;
4014        for (;;) {
4015                ch = *cp;
4016                if ( !dot && ch == '.' ) {
4017                        scale = 1;
4018                        dot = 1;
4019                } else if ( ch == '%' ) {
4020                        scale = dot ? scale*100 : 100;
4021                        cp++;   /* % is always at the end */
4022                        break;
4023                } else if ( ch >= '0' && ch <= '9' ) {
4024                        if ( scale < 100000 ) {
4025                                scale *= 10;
4026                                num = (num*10) + (ch-'0');
4027                        }
4028                } else {
4029                        break;
4030                }
4031                cp++;
4032        }
4033        *cp_p = cp;
4034
4035        /* user says num divided by scale and we say internally that
4036         * is MAX_SCORE * num / scale.
4037         */
4038        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4039}
4040
4041static int diff_scoreopt_parse(const char *opt)
4042{
4043        int opt1, opt2, cmd;
4044
4045        if (*opt++ != '-')
4046                return -1;
4047        cmd = *opt++;
4048        if (cmd == '-') {
4049                /* convert the long-form arguments into short-form versions */
4050                if (skip_prefix(opt, "break-rewrites", &opt)) {
4051                        if (*opt == 0 || *opt++ == '=')
4052                                cmd = 'B';
4053                } else if (skip_prefix(opt, "find-copies", &opt)) {
4054                        if (*opt == 0 || *opt++ == '=')
4055                                cmd = 'C';
4056                } else if (skip_prefix(opt, "find-renames", &opt)) {
4057                        if (*opt == 0 || *opt++ == '=')
4058                                cmd = 'M';
4059                }
4060        }
4061        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4062                return -1; /* that is not a -M, -C, or -B option */
4063
4064        opt1 = parse_rename_score(&opt);
4065        if (cmd != 'B')
4066                opt2 = 0;
4067        else {
4068                if (*opt == 0)
4069                        opt2 = 0;
4070                else if (*opt != '/')
4071                        return -1; /* we expect -B80/99 or -B80 */
4072                else {
4073                        opt++;
4074                        opt2 = parse_rename_score(&opt);
4075                }
4076        }
4077        if (*opt != 0)
4078                return -1;
4079        return opt1 | (opt2 << 16);
4080}
4081
4082struct diff_queue_struct diff_queued_diff;
4083
4084void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4085{
4086        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4087        queue->queue[queue->nr++] = dp;
4088}
4089
4090struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4091                                 struct diff_filespec *one,
4092                                 struct diff_filespec *two)
4093{
4094        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4095        dp->one = one;
4096        dp->two = two;
4097        if (queue)
4098                diff_q(queue, dp);
4099        return dp;
4100}
4101
4102void diff_free_filepair(struct diff_filepair *p)
4103{
4104        free_filespec(p->one);
4105        free_filespec(p->two);
4106        free(p);
4107}
4108
4109/* This is different from find_unique_abbrev() in that
4110 * it stuffs the result with dots for alignment.
4111 */
4112const char *diff_unique_abbrev(const unsigned char *sha1, int len)
4113{
4114        int abblen;
4115        const char *abbrev;
4116        if (len == 40)
4117                return sha1_to_hex(sha1);
4118
4119        abbrev = find_unique_abbrev(sha1, len);
4120        abblen = strlen(abbrev);
4121        if (abblen < 37) {
4122                static char hex[41];
4123                if (len < abblen && abblen <= len + 2)
4124                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4125                else
4126                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4127                return hex;
4128        }
4129        return sha1_to_hex(sha1);
4130}
4131
4132static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4133{
4134        int line_termination = opt->line_termination;
4135        int inter_name_termination = line_termination ? '\t' : '\0';
4136
4137        fprintf(opt->file, "%s", diff_line_prefix(opt));
4138        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4139                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4140                        diff_unique_abbrev(p->one->oid.hash, opt->abbrev));
4141                fprintf(opt->file, "%s ",
4142                        diff_unique_abbrev(p->two->oid.hash, opt->abbrev));
4143        }
4144        if (p->score) {
4145                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4146                        inter_name_termination);
4147        } else {
4148                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4149        }
4150
4151        if (p->status == DIFF_STATUS_COPIED ||
4152            p->status == DIFF_STATUS_RENAMED) {
4153                const char *name_a, *name_b;
4154                name_a = p->one->path;
4155                name_b = p->two->path;
4156                strip_prefix(opt->prefix_length, &name_a, &name_b);
4157                write_name_quoted(name_a, opt->file, inter_name_termination);
4158                write_name_quoted(name_b, opt->file, line_termination);
4159        } else {
4160                const char *name_a, *name_b;
4161                name_a = p->one->mode ? p->one->path : p->two->path;
4162                name_b = NULL;
4163                strip_prefix(opt->prefix_length, &name_a, &name_b);
4164                write_name_quoted(name_a, opt->file, line_termination);
4165        }
4166}
4167
4168int diff_unmodified_pair(struct diff_filepair *p)
4169{
4170        /* This function is written stricter than necessary to support
4171         * the currently implemented transformers, but the idea is to
4172         * let transformers to produce diff_filepairs any way they want,
4173         * and filter and clean them up here before producing the output.
4174         */
4175        struct diff_filespec *one = p->one, *two = p->two;
4176
4177        if (DIFF_PAIR_UNMERGED(p))
4178                return 0; /* unmerged is interesting */
4179
4180        /* deletion, addition, mode or type change
4181         * and rename are all interesting.
4182         */
4183        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4184            DIFF_PAIR_MODE_CHANGED(p) ||
4185            strcmp(one->path, two->path))
4186                return 0;
4187
4188        /* both are valid and point at the same path.  that is, we are
4189         * dealing with a change.
4190         */
4191        if (one->oid_valid && two->oid_valid &&
4192            !oidcmp(&one->oid, &two->oid) &&
4193            !one->dirty_submodule && !two->dirty_submodule)
4194                return 1; /* no change */
4195        if (!one->oid_valid && !two->oid_valid)
4196                return 1; /* both look at the same file on the filesystem. */
4197        return 0;
4198}
4199
4200static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4201{
4202        if (diff_unmodified_pair(p))
4203                return;
4204
4205        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4206            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4207                return; /* no tree diffs in patch format */
4208
4209        run_diff(p, o);
4210}
4211
4212static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4213                            struct diffstat_t *diffstat)
4214{
4215        if (diff_unmodified_pair(p))
4216                return;
4217
4218        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4219            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4220                return; /* no useful stat for tree diffs */
4221
4222        run_diffstat(p, o, diffstat);
4223}
4224
4225static void diff_flush_checkdiff(struct diff_filepair *p,
4226                struct diff_options *o)
4227{
4228        if (diff_unmodified_pair(p))
4229                return;
4230
4231        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4232            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4233                return; /* nothing to check in tree diffs */
4234
4235        run_checkdiff(p, o);
4236}
4237
4238int diff_queue_is_empty(void)
4239{
4240        struct diff_queue_struct *q = &diff_queued_diff;
4241        int i;
4242        for (i = 0; i < q->nr; i++)
4243                if (!diff_unmodified_pair(q->queue[i]))
4244                        return 0;
4245        return 1;
4246}
4247
4248#if DIFF_DEBUG
4249void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4250{
4251        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4252                x, one ? one : "",
4253                s->path,
4254                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4255                s->mode,
4256                s->oid_valid ? oid_to_hex(&s->oid) : "");
4257        fprintf(stderr, "queue[%d] %s size %lu\n",
4258                x, one ? one : "",
4259                s->size);
4260}
4261
4262void diff_debug_filepair(const struct diff_filepair *p, int i)
4263{
4264        diff_debug_filespec(p->one, i, "one");
4265        diff_debug_filespec(p->two, i, "two");
4266        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4267                p->score, p->status ? p->status : '?',
4268                p->one->rename_used, p->broken_pair);
4269}
4270
4271void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4272{
4273        int i;
4274        if (msg)
4275                fprintf(stderr, "%s\n", msg);
4276        fprintf(stderr, "q->nr = %d\n", q->nr);
4277        for (i = 0; i < q->nr; i++) {
4278                struct diff_filepair *p = q->queue[i];
4279                diff_debug_filepair(p, i);
4280        }
4281}
4282#endif
4283
4284static void diff_resolve_rename_copy(void)
4285{
4286        int i;
4287        struct diff_filepair *p;
4288        struct diff_queue_struct *q = &diff_queued_diff;
4289
4290        diff_debug_queue("resolve-rename-copy", q);
4291
4292        for (i = 0; i < q->nr; i++) {
4293                p = q->queue[i];
4294                p->status = 0; /* undecided */
4295                if (DIFF_PAIR_UNMERGED(p))
4296                        p->status = DIFF_STATUS_UNMERGED;
4297                else if (!DIFF_FILE_VALID(p->one))
4298                        p->status = DIFF_STATUS_ADDED;
4299                else if (!DIFF_FILE_VALID(p->two))
4300                        p->status = DIFF_STATUS_DELETED;
4301                else if (DIFF_PAIR_TYPE_CHANGED(p))
4302                        p->status = DIFF_STATUS_TYPE_CHANGED;
4303
4304                /* from this point on, we are dealing with a pair
4305                 * whose both sides are valid and of the same type, i.e.
4306                 * either in-place edit or rename/copy edit.
4307                 */
4308                else if (DIFF_PAIR_RENAME(p)) {
4309                        /*
4310                         * A rename might have re-connected a broken
4311                         * pair up, causing the pathnames to be the
4312                         * same again. If so, that's not a rename at
4313                         * all, just a modification..
4314                         *
4315                         * Otherwise, see if this source was used for
4316                         * multiple renames, in which case we decrement
4317                         * the count, and call it a copy.
4318                         */
4319                        if (!strcmp(p->one->path, p->two->path))
4320                                p->status = DIFF_STATUS_MODIFIED;
4321                        else if (--p->one->rename_used > 0)
4322                                p->status = DIFF_STATUS_COPIED;
4323                        else
4324                                p->status = DIFF_STATUS_RENAMED;
4325                }
4326                else if (oidcmp(&p->one->oid, &p->two->oid) ||
4327                         p->one->mode != p->two->mode ||
4328                         p->one->dirty_submodule ||
4329                         p->two->dirty_submodule ||
4330                         is_null_oid(&p->one->oid))
4331                        p->status = DIFF_STATUS_MODIFIED;
4332                else {
4333                        /* This is a "no-change" entry and should not
4334                         * happen anymore, but prepare for broken callers.
4335                         */
4336                        error("feeding unmodified %s to diffcore",
4337                              p->one->path);
4338                        p->status = DIFF_STATUS_UNKNOWN;
4339                }
4340        }
4341        diff_debug_queue("resolve-rename-copy done", q);
4342}
4343
4344static int check_pair_status(struct diff_filepair *p)
4345{
4346        switch (p->status) {
4347        case DIFF_STATUS_UNKNOWN:
4348                return 0;
4349        case 0:
4350                die("internal error in diff-resolve-rename-copy");
4351        default:
4352                return 1;
4353        }
4354}
4355
4356static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4357{
4358        int fmt = opt->output_format;
4359
4360        if (fmt & DIFF_FORMAT_CHECKDIFF)
4361                diff_flush_checkdiff(p, opt);
4362        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4363                diff_flush_raw(p, opt);
4364        else if (fmt & DIFF_FORMAT_NAME) {
4365                const char *name_a, *name_b;
4366                name_a = p->two->path;
4367                name_b = NULL;
4368                strip_prefix(opt->prefix_length, &name_a, &name_b);
4369                write_name_quoted(name_a, opt->file, opt->line_termination);
4370        }
4371}
4372
4373static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4374{
4375        if (fs->mode)
4376                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4377        else
4378                fprintf(file, " %s ", newdelete);
4379        write_name_quoted(fs->path, file, '\n');
4380}
4381
4382
4383static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4384                const char *line_prefix)
4385{
4386        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4387                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4388                        p->two->mode, show_name ? ' ' : '\n');
4389                if (show_name) {
4390                        write_name_quoted(p->two->path, file, '\n');
4391                }
4392        }
4393}
4394
4395static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4396                        const char *line_prefix)
4397{
4398        char *names = pprint_rename(p->one->path, p->two->path);
4399
4400        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4401        free(names);
4402        show_mode_change(file, p, 0, line_prefix);
4403}
4404
4405static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4406{
4407        FILE *file = opt->file;
4408        const char *line_prefix = diff_line_prefix(opt);
4409
4410        switch(p->status) {
4411        case DIFF_STATUS_DELETED:
4412                fputs(line_prefix, file);
4413                show_file_mode_name(file, "delete", p->one);
4414                break;
4415        case DIFF_STATUS_ADDED:
4416                fputs(line_prefix, file);
4417                show_file_mode_name(file, "create", p->two);
4418                break;
4419        case DIFF_STATUS_COPIED:
4420                fputs(line_prefix, file);
4421                show_rename_copy(file, "copy", p, line_prefix);
4422                break;
4423        case DIFF_STATUS_RENAMED:
4424                fputs(line_prefix, file);
4425                show_rename_copy(file, "rename", p, line_prefix);
4426                break;
4427        default:
4428                if (p->score) {
4429                        fprintf(file, "%s rewrite ", line_prefix);
4430                        write_name_quoted(p->two->path, file, ' ');
4431                        fprintf(file, "(%d%%)\n", similarity_index(p));
4432                }
4433                show_mode_change(file, p, !p->score, line_prefix);
4434                break;
4435        }
4436}
4437
4438struct patch_id_t {
4439        git_SHA_CTX *ctx;
4440        int patchlen;
4441};
4442
4443static int remove_space(char *line, int len)
4444{
4445        int i;
4446        char *dst = line;
4447        unsigned char c;
4448
4449        for (i = 0; i < len; i++)
4450                if (!isspace((c = line[i])))
4451                        *dst++ = c;
4452
4453        return dst - line;
4454}
4455
4456static void patch_id_consume(void *priv, char *line, unsigned long len)
4457{
4458        struct patch_id_t *data = priv;
4459        int new_len;
4460
4461        /* Ignore line numbers when computing the SHA1 of the patch */
4462        if (starts_with(line, "@@ -"))
4463                return;
4464
4465        new_len = remove_space(line, len);
4466
4467        git_SHA1_Update(data->ctx, line, new_len);
4468        data->patchlen += new_len;
4469}
4470
4471/* returns 0 upon success, and writes result into sha1 */
4472static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4473{
4474        struct diff_queue_struct *q = &diff_queued_diff;
4475        int i;
4476        git_SHA_CTX ctx;
4477        struct patch_id_t data;
4478        char buffer[PATH_MAX * 4 + 20];
4479
4480        git_SHA1_Init(&ctx);
4481        memset(&data, 0, sizeof(struct patch_id_t));
4482        data.ctx = &ctx;
4483
4484        for (i = 0; i < q->nr; i++) {
4485                xpparam_t xpp;
4486                xdemitconf_t xecfg;
4487                mmfile_t mf1, mf2;
4488                struct diff_filepair *p = q->queue[i];
4489                int len1, len2;
4490
4491                memset(&xpp, 0, sizeof(xpp));
4492                memset(&xecfg, 0, sizeof(xecfg));
4493                if (p->status == 0)
4494                        return error("internal diff status error");
4495                if (p->status == DIFF_STATUS_UNKNOWN)
4496                        continue;
4497                if (diff_unmodified_pair(p))
4498                        continue;
4499                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4500                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4501                        continue;
4502                if (DIFF_PAIR_UNMERGED(p))
4503                        continue;
4504
4505                diff_fill_sha1_info(p->one);
4506                diff_fill_sha1_info(p->two);
4507                if (fill_mmfile(&mf1, p->one) < 0 ||
4508                                fill_mmfile(&mf2, p->two) < 0)
4509                        return error("unable to read files to diff");
4510
4511                len1 = remove_space(p->one->path, strlen(p->one->path));
4512                len2 = remove_space(p->two->path, strlen(p->two->path));
4513                if (p->one->mode == 0)
4514                        len1 = snprintf(buffer, sizeof(buffer),
4515                                        "diff--gita/%.*sb/%.*s"
4516                                        "newfilemode%06o"
4517                                        "---/dev/null"
4518                                        "+++b/%.*s",
4519                                        len1, p->one->path,
4520                                        len2, p->two->path,
4521                                        p->two->mode,
4522                                        len2, p->two->path);
4523                else if (p->two->mode == 0)
4524                        len1 = snprintf(buffer, sizeof(buffer),
4525                                        "diff--gita/%.*sb/%.*s"
4526                                        "deletedfilemode%06o"
4527                                        "---a/%.*s"
4528                                        "+++/dev/null",
4529                                        len1, p->one->path,
4530                                        len2, p->two->path,
4531                                        p->one->mode,
4532                                        len1, p->one->path);
4533                else
4534                        len1 = snprintf(buffer, sizeof(buffer),
4535                                        "diff--gita/%.*sb/%.*s"
4536                                        "---a/%.*s"
4537                                        "+++b/%.*s",
4538                                        len1, p->one->path,
4539                                        len2, p->two->path,
4540                                        len1, p->one->path,
4541                                        len2, p->two->path);
4542                git_SHA1_Update(&ctx, buffer, len1);
4543
4544                if (diff_filespec_is_binary(p->one) ||
4545                    diff_filespec_is_binary(p->two)) {
4546                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
4547                                        40);
4548                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
4549                                        40);
4550                        continue;
4551                }
4552
4553                xpp.flags = 0;
4554                xecfg.ctxlen = 3;
4555                xecfg.flags = 0;
4556                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4557                                  &xpp, &xecfg))
4558                        return error("unable to generate patch-id diff for %s",
4559                                     p->one->path);
4560        }
4561
4562        git_SHA1_Final(sha1, &ctx);
4563        return 0;
4564}
4565
4566int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4567{
4568        struct diff_queue_struct *q = &diff_queued_diff;
4569        int i;
4570        int result = diff_get_patch_id(options, sha1);
4571
4572        for (i = 0; i < q->nr; i++)
4573                diff_free_filepair(q->queue[i]);
4574
4575        free(q->queue);
4576        DIFF_QUEUE_CLEAR(q);
4577
4578        return result;
4579}
4580
4581static int is_summary_empty(const struct diff_queue_struct *q)
4582{
4583        int i;
4584
4585        for (i = 0; i < q->nr; i++) {
4586                const struct diff_filepair *p = q->queue[i];
4587
4588                switch (p->status) {
4589                case DIFF_STATUS_DELETED:
4590                case DIFF_STATUS_ADDED:
4591                case DIFF_STATUS_COPIED:
4592                case DIFF_STATUS_RENAMED:
4593                        return 0;
4594                default:
4595                        if (p->score)
4596                                return 0;
4597                        if (p->one->mode && p->two->mode &&
4598                            p->one->mode != p->two->mode)
4599                                return 0;
4600                        break;
4601                }
4602        }
4603        return 1;
4604}
4605
4606static const char rename_limit_warning[] =
4607"inexact rename detection was skipped due to too many files.";
4608
4609static const char degrade_cc_to_c_warning[] =
4610"only found copies from modified paths due to too many files.";
4611
4612static const char rename_limit_advice[] =
4613"you may want to set your %s variable to at least "
4614"%d and retry the command.";
4615
4616void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4617{
4618        if (degraded_cc)
4619                warning(degrade_cc_to_c_warning);
4620        else if (needed)
4621                warning(rename_limit_warning);
4622        else
4623                return;
4624        if (0 < needed && needed < 32767)
4625                warning(rename_limit_advice, varname, needed);
4626}
4627
4628void diff_flush(struct diff_options *options)
4629{
4630        struct diff_queue_struct *q = &diff_queued_diff;
4631        int i, output_format = options->output_format;
4632        int separator = 0;
4633        int dirstat_by_line = 0;
4634
4635        /*
4636         * Order: raw, stat, summary, patch
4637         * or:    name/name-status/checkdiff (other bits clear)
4638         */
4639        if (!q->nr)
4640                goto free_queue;
4641
4642        if (output_format & (DIFF_FORMAT_RAW |
4643                             DIFF_FORMAT_NAME |
4644                             DIFF_FORMAT_NAME_STATUS |
4645                             DIFF_FORMAT_CHECKDIFF)) {
4646                for (i = 0; i < q->nr; i++) {
4647                        struct diff_filepair *p = q->queue[i];
4648                        if (check_pair_status(p))
4649                                flush_one_pair(p, options);
4650                }
4651                separator++;
4652        }
4653
4654        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4655                dirstat_by_line = 1;
4656
4657        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4658            dirstat_by_line) {
4659                struct diffstat_t diffstat;
4660
4661                memset(&diffstat, 0, sizeof(struct diffstat_t));
4662                for (i = 0; i < q->nr; i++) {
4663                        struct diff_filepair *p = q->queue[i];
4664                        if (check_pair_status(p))
4665                                diff_flush_stat(p, options, &diffstat);
4666                }
4667                if (output_format & DIFF_FORMAT_NUMSTAT)
4668                        show_numstat(&diffstat, options);
4669                if (output_format & DIFF_FORMAT_DIFFSTAT)
4670                        show_stats(&diffstat, options);
4671                if (output_format & DIFF_FORMAT_SHORTSTAT)
4672                        show_shortstats(&diffstat, options);
4673                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4674                        show_dirstat_by_line(&diffstat, options);
4675                free_diffstat_info(&diffstat);
4676                separator++;
4677        }
4678        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4679                show_dirstat(options);
4680
4681        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4682                for (i = 0; i < q->nr; i++) {
4683                        diff_summary(options, q->queue[i]);
4684                }
4685                separator++;
4686        }
4687
4688        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4689            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4690            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4691                /*
4692                 * run diff_flush_patch for the exit status. setting
4693                 * options->file to /dev/null should be safe, because we
4694                 * aren't supposed to produce any output anyway.
4695                 */
4696                if (options->close_file)
4697                        fclose(options->file);
4698                options->file = fopen("/dev/null", "w");
4699                if (!options->file)
4700                        die_errno("Could not open /dev/null");
4701                options->close_file = 1;
4702                for (i = 0; i < q->nr; i++) {
4703                        struct diff_filepair *p = q->queue[i];
4704                        if (check_pair_status(p))
4705                                diff_flush_patch(p, options);
4706                        if (options->found_changes)
4707                                break;
4708                }
4709        }
4710
4711        if (output_format & DIFF_FORMAT_PATCH) {
4712                if (separator) {
4713                        fprintf(options->file, "%s%c",
4714                                diff_line_prefix(options),
4715                                options->line_termination);
4716                        if (options->stat_sep) {
4717                                /* attach patch instead of inline */
4718                                fputs(options->stat_sep, options->file);
4719                        }
4720                }
4721
4722                for (i = 0; i < q->nr; i++) {
4723                        struct diff_filepair *p = q->queue[i];
4724                        if (check_pair_status(p))
4725                                diff_flush_patch(p, options);
4726                }
4727        }
4728
4729        if (output_format & DIFF_FORMAT_CALLBACK)
4730                options->format_callback(q, options, options->format_callback_data);
4731
4732        for (i = 0; i < q->nr; i++)
4733                diff_free_filepair(q->queue[i]);
4734free_queue:
4735        free(q->queue);
4736        DIFF_QUEUE_CLEAR(q);
4737        if (options->close_file)
4738                fclose(options->file);
4739
4740        /*
4741         * Report the content-level differences with HAS_CHANGES;
4742         * diff_addremove/diff_change does not set the bit when
4743         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4744         */
4745        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4746                if (options->found_changes)
4747                        DIFF_OPT_SET(options, HAS_CHANGES);
4748                else
4749                        DIFF_OPT_CLR(options, HAS_CHANGES);
4750        }
4751}
4752
4753static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4754{
4755        return (((p->status == DIFF_STATUS_MODIFIED) &&
4756                 ((p->score &&
4757                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4758                  (!p->score &&
4759                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4760                ((p->status != DIFF_STATUS_MODIFIED) &&
4761                 filter_bit_tst(p->status, options)));
4762}
4763
4764static void diffcore_apply_filter(struct diff_options *options)
4765{
4766        int i;
4767        struct diff_queue_struct *q = &diff_queued_diff;
4768        struct diff_queue_struct outq;
4769
4770        DIFF_QUEUE_CLEAR(&outq);
4771
4772        if (!options->filter)
4773                return;
4774
4775        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4776                int found;
4777                for (i = found = 0; !found && i < q->nr; i++) {
4778                        if (match_filter(options, q->queue[i]))
4779                                found++;
4780                }
4781                if (found)
4782                        return;
4783
4784                /* otherwise we will clear the whole queue
4785                 * by copying the empty outq at the end of this
4786                 * function, but first clear the current entries
4787                 * in the queue.
4788                 */
4789                for (i = 0; i < q->nr; i++)
4790                        diff_free_filepair(q->queue[i]);
4791        }
4792        else {
4793                /* Only the matching ones */
4794                for (i = 0; i < q->nr; i++) {
4795                        struct diff_filepair *p = q->queue[i];
4796                        if (match_filter(options, p))
4797                                diff_q(&outq, p);
4798                        else
4799                                diff_free_filepair(p);
4800                }
4801        }
4802        free(q->queue);
4803        *q = outq;
4804}
4805
4806/* Check whether two filespecs with the same mode and size are identical */
4807static int diff_filespec_is_identical(struct diff_filespec *one,
4808                                      struct diff_filespec *two)
4809{
4810        if (S_ISGITLINK(one->mode))
4811                return 0;
4812        if (diff_populate_filespec(one, 0))
4813                return 0;
4814        if (diff_populate_filespec(two, 0))
4815                return 0;
4816        return !memcmp(one->data, two->data, one->size);
4817}
4818
4819static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4820{
4821        if (p->done_skip_stat_unmatch)
4822                return p->skip_stat_unmatch_result;
4823
4824        p->done_skip_stat_unmatch = 1;
4825        p->skip_stat_unmatch_result = 0;
4826        /*
4827         * 1. Entries that come from stat info dirtiness
4828         *    always have both sides (iow, not create/delete),
4829         *    one side of the object name is unknown, with
4830         *    the same mode and size.  Keep the ones that
4831         *    do not match these criteria.  They have real
4832         *    differences.
4833         *
4834         * 2. At this point, the file is known to be modified,
4835         *    with the same mode and size, and the object
4836         *    name of one side is unknown.  Need to inspect
4837         *    the identical contents.
4838         */
4839        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4840            !DIFF_FILE_VALID(p->two) ||
4841            (p->one->oid_valid && p->two->oid_valid) ||
4842            (p->one->mode != p->two->mode) ||
4843            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4844            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4845            (p->one->size != p->two->size) ||
4846            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4847                p->skip_stat_unmatch_result = 1;
4848        return p->skip_stat_unmatch_result;
4849}
4850
4851static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4852{
4853        int i;
4854        struct diff_queue_struct *q = &diff_queued_diff;
4855        struct diff_queue_struct outq;
4856        DIFF_QUEUE_CLEAR(&outq);
4857
4858        for (i = 0; i < q->nr; i++) {
4859                struct diff_filepair *p = q->queue[i];
4860
4861                if (diff_filespec_check_stat_unmatch(p))
4862                        diff_q(&outq, p);
4863                else {
4864                        /*
4865                         * The caller can subtract 1 from skip_stat_unmatch
4866                         * to determine how many paths were dirty only
4867                         * due to stat info mismatch.
4868                         */
4869                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4870                                diffopt->skip_stat_unmatch++;
4871                        diff_free_filepair(p);
4872                }
4873        }
4874        free(q->queue);
4875        *q = outq;
4876}
4877
4878static int diffnamecmp(const void *a_, const void *b_)
4879{
4880        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4881        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4882        const char *name_a, *name_b;
4883
4884        name_a = a->one ? a->one->path : a->two->path;
4885        name_b = b->one ? b->one->path : b->two->path;
4886        return strcmp(name_a, name_b);
4887}
4888
4889void diffcore_fix_diff_index(struct diff_options *options)
4890{
4891        struct diff_queue_struct *q = &diff_queued_diff;
4892        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4893}
4894
4895void diffcore_std(struct diff_options *options)
4896{
4897        /* NOTE please keep the following in sync with diff_tree_combined() */
4898        if (options->skip_stat_unmatch)
4899                diffcore_skip_stat_unmatch(options);
4900        if (!options->found_follow) {
4901                /* See try_to_follow_renames() in tree-diff.c */
4902                if (options->break_opt != -1)
4903                        diffcore_break(options->break_opt);
4904                if (options->detect_rename)
4905                        diffcore_rename(options);
4906                if (options->break_opt != -1)
4907                        diffcore_merge_broken();
4908        }
4909        if (options->pickaxe)
4910                diffcore_pickaxe(options);
4911        if (options->orderfile)
4912                diffcore_order(options->orderfile);
4913        if (!options->found_follow)
4914                /* See try_to_follow_renames() in tree-diff.c */
4915                diff_resolve_rename_copy();
4916        diffcore_apply_filter(options);
4917
4918        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4919                DIFF_OPT_SET(options, HAS_CHANGES);
4920        else
4921                DIFF_OPT_CLR(options, HAS_CHANGES);
4922
4923        options->found_follow = 0;
4924}
4925
4926int diff_result_code(struct diff_options *opt, int status)
4927{
4928        int result = 0;
4929
4930        diff_warn_rename_limit("diff.renameLimit",
4931                               opt->needed_rename_limit,
4932                               opt->degraded_cc_to_c);
4933        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4934            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4935                return status;
4936        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4937            DIFF_OPT_TST(opt, HAS_CHANGES))
4938                result |= 01;
4939        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4940            DIFF_OPT_TST(opt, CHECK_FAILED))
4941                result |= 02;
4942        return result;
4943}
4944
4945int diff_can_quit_early(struct diff_options *opt)
4946{
4947        return (DIFF_OPT_TST(opt, QUICK) &&
4948                !opt->filter &&
4949                DIFF_OPT_TST(opt, HAS_CHANGES));
4950}
4951
4952/*
4953 * Shall changes to this submodule be ignored?
4954 *
4955 * Submodule changes can be configured to be ignored separately for each path,
4956 * but that configuration can be overridden from the command line.
4957 */
4958static int is_submodule_ignored(const char *path, struct diff_options *options)
4959{
4960        int ignored = 0;
4961        unsigned orig_flags = options->flags;
4962        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4963                set_diffopt_flags_from_submodule_config(options, path);
4964        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4965                ignored = 1;
4966        options->flags = orig_flags;
4967        return ignored;
4968}
4969
4970void diff_addremove(struct diff_options *options,
4971                    int addremove, unsigned mode,
4972                    const unsigned char *sha1,
4973                    int sha1_valid,
4974                    const char *concatpath, unsigned dirty_submodule)
4975{
4976        struct diff_filespec *one, *two;
4977
4978        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4979                return;
4980
4981        /* This may look odd, but it is a preparation for
4982         * feeding "there are unchanged files which should
4983         * not produce diffs, but when you are doing copy
4984         * detection you would need them, so here they are"
4985         * entries to the diff-core.  They will be prefixed
4986         * with something like '=' or '*' (I haven't decided
4987         * which but should not make any difference).
4988         * Feeding the same new and old to diff_change()
4989         * also has the same effect.
4990         * Before the final output happens, they are pruned after
4991         * merged into rename/copy pairs as appropriate.
4992         */
4993        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4994                addremove = (addremove == '+' ? '-' :
4995                             addremove == '-' ? '+' : addremove);
4996
4997        if (options->prefix &&
4998            strncmp(concatpath, options->prefix, options->prefix_length))
4999                return;
5000
5001        one = alloc_filespec(concatpath);
5002        two = alloc_filespec(concatpath);
5003
5004        if (addremove != '+')
5005                fill_filespec(one, sha1, sha1_valid, mode);
5006        if (addremove != '-') {
5007                fill_filespec(two, sha1, sha1_valid, mode);
5008                two->dirty_submodule = dirty_submodule;
5009        }
5010
5011        diff_queue(&diff_queued_diff, one, two);
5012        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5013                DIFF_OPT_SET(options, HAS_CHANGES);
5014}
5015
5016void diff_change(struct diff_options *options,
5017                 unsigned old_mode, unsigned new_mode,
5018                 const unsigned char *old_sha1,
5019                 const unsigned char *new_sha1,
5020                 int old_sha1_valid, int new_sha1_valid,
5021                 const char *concatpath,
5022                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5023{
5024        struct diff_filespec *one, *two;
5025        struct diff_filepair *p;
5026
5027        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5028            is_submodule_ignored(concatpath, options))
5029                return;
5030
5031        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5032                unsigned tmp;
5033                const unsigned char *tmp_c;
5034                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
5035                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
5036                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
5037                        new_sha1_valid = tmp;
5038                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
5039                        new_dirty_submodule = tmp;
5040        }
5041
5042        if (options->prefix &&
5043            strncmp(concatpath, options->prefix, options->prefix_length))
5044                return;
5045
5046        one = alloc_filespec(concatpath);
5047        two = alloc_filespec(concatpath);
5048        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
5049        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
5050        one->dirty_submodule = old_dirty_submodule;
5051        two->dirty_submodule = new_dirty_submodule;
5052        p = diff_queue(&diff_queued_diff, one, two);
5053
5054        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5055                return;
5056
5057        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5058            !diff_filespec_check_stat_unmatch(p))
5059                return;
5060
5061        DIFF_OPT_SET(options, HAS_CHANGES);
5062}
5063
5064struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5065{
5066        struct diff_filepair *pair;
5067        struct diff_filespec *one, *two;
5068
5069        if (options->prefix &&
5070            strncmp(path, options->prefix, options->prefix_length))
5071                return NULL;
5072
5073        one = alloc_filespec(path);
5074        two = alloc_filespec(path);
5075        pair = diff_queue(&diff_queued_diff, one, two);
5076        pair->is_unmerged = 1;
5077        return pair;
5078}
5079
5080static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5081                size_t *outsize)
5082{
5083        struct diff_tempfile *temp;
5084        const char *argv[3];
5085        const char **arg = argv;
5086        struct child_process child = CHILD_PROCESS_INIT;
5087        struct strbuf buf = STRBUF_INIT;
5088        int err = 0;
5089
5090        temp = prepare_temp_file(spec->path, spec);
5091        *arg++ = pgm;
5092        *arg++ = temp->name;
5093        *arg = NULL;
5094
5095        child.use_shell = 1;
5096        child.argv = argv;
5097        child.out = -1;
5098        if (start_command(&child)) {
5099                remove_tempfile();
5100                return NULL;
5101        }
5102
5103        if (strbuf_read(&buf, child.out, 0) < 0)
5104                err = error("error reading from textconv command '%s'", pgm);
5105        close(child.out);
5106
5107        if (finish_command(&child) || err) {
5108                strbuf_release(&buf);
5109                remove_tempfile();
5110                return NULL;
5111        }
5112        remove_tempfile();
5113
5114        return strbuf_detach(&buf, outsize);
5115}
5116
5117size_t fill_textconv(struct userdiff_driver *driver,
5118                     struct diff_filespec *df,
5119                     char **outbuf)
5120{
5121        size_t size;
5122
5123        if (!driver) {
5124                if (!DIFF_FILE_VALID(df)) {
5125                        *outbuf = "";
5126                        return 0;
5127                }
5128                if (diff_populate_filespec(df, 0))
5129                        die("unable to read files to diff");
5130                *outbuf = df->data;
5131                return df->size;
5132        }
5133
5134        if (!driver->textconv)
5135                die("BUG: fill_textconv called with non-textconv driver");
5136
5137        if (driver->textconv_cache && df->oid_valid) {
5138                *outbuf = notes_cache_get(driver->textconv_cache,
5139                                          df->oid.hash,
5140                                          &size);
5141                if (*outbuf)
5142                        return size;
5143        }
5144
5145        *outbuf = run_textconv(driver->textconv, df, &size);
5146        if (!*outbuf)
5147                die("unable to read files to diff");
5148
5149        if (driver->textconv_cache && df->oid_valid) {
5150                /* ignore errors, as we might be in a readonly repository */
5151                notes_cache_put(driver->textconv_cache, df->oid.hash, *outbuf,
5152                                size);
5153                /*
5154                 * we could save up changes and flush them all at the end,
5155                 * but we would need an extra call after all diffing is done.
5156                 * Since generating a cache entry is the slow path anyway,
5157                 * this extra overhead probably isn't a big deal.
5158                 */
5159                notes_cache_write(driver->textconv_cache);
5160        }
5161
5162        return size;
5163}
5164
5165void setup_diff_pager(struct diff_options *opt)
5166{
5167        /*
5168         * If the user asked for our exit code, then either they want --quiet
5169         * or --exit-code. We should definitely not bother with a pager in the
5170         * former case, as we will generate no output. Since we still properly
5171         * report our exit code even when a pager is run, we _could_ run a
5172         * pager with --exit-code. But since we have not done so historically,
5173         * and because it is easy to find people oneline advising "git diff
5174         * --exit-code" in hooks and other scripts, we do not do so.
5175         */
5176        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5177            check_pager_config("diff") != 0)
5178                setup_pager();
5179}