diff.con commit Merge branch 'jc/maint-ident-missing-human-name' (13670c5)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static int diff_stat_graph_width;
  35static int diff_dirstat_permille_default = 30;
  36static struct diff_options default_diff_options;
  37
  38static char diff_colors[][COLOR_MAXLEN] = {
  39        GIT_COLOR_RESET,
  40        GIT_COLOR_NORMAL,       /* PLAIN */
  41        GIT_COLOR_BOLD,         /* METAINFO */
  42        GIT_COLOR_CYAN,         /* FRAGINFO */
  43        GIT_COLOR_RED,          /* OLD */
  44        GIT_COLOR_GREEN,        /* NEW */
  45        GIT_COLOR_YELLOW,       /* COMMIT */
  46        GIT_COLOR_BG_RED,       /* WHITESPACE */
  47        GIT_COLOR_NORMAL,       /* FUNCINFO */
  48};
  49
  50static int parse_diff_color_slot(const char *var, int ofs)
  51{
  52        if (!strcasecmp(var+ofs, "plain"))
  53                return DIFF_PLAIN;
  54        if (!strcasecmp(var+ofs, "meta"))
  55                return DIFF_METAINFO;
  56        if (!strcasecmp(var+ofs, "frag"))
  57                return DIFF_FRAGINFO;
  58        if (!strcasecmp(var+ofs, "old"))
  59                return DIFF_FILE_OLD;
  60        if (!strcasecmp(var+ofs, "new"))
  61                return DIFF_FILE_NEW;
  62        if (!strcasecmp(var+ofs, "commit"))
  63                return DIFF_COMMIT;
  64        if (!strcasecmp(var+ofs, "whitespace"))
  65                return DIFF_WHITESPACE;
  66        if (!strcasecmp(var+ofs, "func"))
  67                return DIFF_FUNCINFO;
  68        return -1;
  69}
  70
  71static int parse_dirstat_params(struct diff_options *options, const char *params,
  72                                struct strbuf *errmsg)
  73{
  74        const char *p = params;
  75        int p_len, ret = 0;
  76
  77        while (*p) {
  78                p_len = strchrnul(p, ',') - p;
  79                if (!memcmp(p, "changes", p_len)) {
  80                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  81                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  82                } else if (!memcmp(p, "lines", p_len)) {
  83                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  84                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  85                } else if (!memcmp(p, "files", p_len)) {
  86                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  87                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  88                } else if (!memcmp(p, "noncumulative", p_len)) {
  89                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  90                } else if (!memcmp(p, "cumulative", p_len)) {
  91                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  92                } else if (isdigit(*p)) {
  93                        char *end;
  94                        int permille = strtoul(p, &end, 10) * 10;
  95                        if (*end == '.' && isdigit(*++end)) {
  96                                /* only use first digit */
  97                                permille += *end - '0';
  98                                /* .. and ignore any further digits */
  99                                while (isdigit(*++end))
 100                                        ; /* nothing */
 101                        }
 102                        if (end - p == p_len)
 103                                options->dirstat_permille = permille;
 104                        else {
 105                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 106                                            p_len, p);
 107                                ret++;
 108                        }
 109                } else {
 110                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 111                                    p_len, p);
 112                        ret++;
 113                }
 114
 115                p += p_len;
 116
 117                if (*p)
 118                        p++; /* more parameters, swallow separator */
 119        }
 120        return ret;
 121}
 122
 123static int git_config_rename(const char *var, const char *value)
 124{
 125        if (!value)
 126                return DIFF_DETECT_RENAME;
 127        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 128                return  DIFF_DETECT_COPY;
 129        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 130}
 131
 132/*
 133 * These are to give UI layer defaults.
 134 * The core-level commands such as git-diff-files should
 135 * never be affected by the setting of diff.renames
 136 * the user happens to have in the configuration file.
 137 */
 138int git_diff_ui_config(const char *var, const char *value, void *cb)
 139{
 140        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 141                diff_use_color_default = git_config_colorbool(var, value);
 142                return 0;
 143        }
 144        if (!strcmp(var, "diff.renames")) {
 145                diff_detect_rename_default = git_config_rename(var, value);
 146                return 0;
 147        }
 148        if (!strcmp(var, "diff.autorefreshindex")) {
 149                diff_auto_refresh_index = git_config_bool(var, value);
 150                return 0;
 151        }
 152        if (!strcmp(var, "diff.mnemonicprefix")) {
 153                diff_mnemonic_prefix = git_config_bool(var, value);
 154                return 0;
 155        }
 156        if (!strcmp(var, "diff.noprefix")) {
 157                diff_no_prefix = git_config_bool(var, value);
 158                return 0;
 159        }
 160        if (!strcmp(var, "diff.statgraphwidth")) {
 161                diff_stat_graph_width = git_config_int(var, value);
 162                return 0;
 163        }
 164        if (!strcmp(var, "diff.external"))
 165                return git_config_string(&external_diff_cmd_cfg, var, value);
 166        if (!strcmp(var, "diff.wordregex"))
 167                return git_config_string(&diff_word_regex_cfg, var, value);
 168
 169        if (!strcmp(var, "diff.ignoresubmodules"))
 170                handle_ignore_submodules_arg(&default_diff_options, value);
 171
 172        if (git_color_config(var, value, cb) < 0)
 173                return -1;
 174
 175        return git_diff_basic_config(var, value, cb);
 176}
 177
 178int git_diff_basic_config(const char *var, const char *value, void *cb)
 179{
 180        if (!strcmp(var, "diff.renamelimit")) {
 181                diff_rename_limit_default = git_config_int(var, value);
 182                return 0;
 183        }
 184
 185        if (userdiff_config(var, value) < 0)
 186                return -1;
 187
 188        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 189                int slot = parse_diff_color_slot(var, 11);
 190                if (slot < 0)
 191                        return 0;
 192                if (!value)
 193                        return config_error_nonbool(var);
 194                color_parse(value, var, diff_colors[slot]);
 195                return 0;
 196        }
 197
 198        /* like GNU diff's --suppress-blank-empty option  */
 199        if (!strcmp(var, "diff.suppressblankempty") ||
 200                        /* for backwards compatibility */
 201                        !strcmp(var, "diff.suppress-blank-empty")) {
 202                diff_suppress_blank_empty = git_config_bool(var, value);
 203                return 0;
 204        }
 205
 206        if (!strcmp(var, "diff.dirstat")) {
 207                struct strbuf errmsg = STRBUF_INIT;
 208                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 209                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 210                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 211                                errmsg.buf);
 212                strbuf_release(&errmsg);
 213                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 214                return 0;
 215        }
 216
 217        if (!prefixcmp(var, "submodule."))
 218                return parse_submodule_config_option(var, value);
 219
 220        return git_default_config(var, value, cb);
 221}
 222
 223static char *quote_two(const char *one, const char *two)
 224{
 225        int need_one = quote_c_style(one, NULL, NULL, 1);
 226        int need_two = quote_c_style(two, NULL, NULL, 1);
 227        struct strbuf res = STRBUF_INIT;
 228
 229        if (need_one + need_two) {
 230                strbuf_addch(&res, '"');
 231                quote_c_style(one, &res, NULL, 1);
 232                quote_c_style(two, &res, NULL, 1);
 233                strbuf_addch(&res, '"');
 234        } else {
 235                strbuf_addstr(&res, one);
 236                strbuf_addstr(&res, two);
 237        }
 238        return strbuf_detach(&res, NULL);
 239}
 240
 241static const char *external_diff(void)
 242{
 243        static const char *external_diff_cmd = NULL;
 244        static int done_preparing = 0;
 245
 246        if (done_preparing)
 247                return external_diff_cmd;
 248        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 249        if (!external_diff_cmd)
 250                external_diff_cmd = external_diff_cmd_cfg;
 251        done_preparing = 1;
 252        return external_diff_cmd;
 253}
 254
 255static struct diff_tempfile {
 256        const char *name; /* filename external diff should read from */
 257        char hex[41];
 258        char mode[10];
 259        char tmp_path[PATH_MAX];
 260} diff_temp[2];
 261
 262typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 263
 264struct emit_callback {
 265        int color_diff;
 266        unsigned ws_rule;
 267        int blank_at_eof_in_preimage;
 268        int blank_at_eof_in_postimage;
 269        int lno_in_preimage;
 270        int lno_in_postimage;
 271        sane_truncate_fn truncate;
 272        const char **label_path;
 273        struct diff_words_data *diff_words;
 274        struct diff_options *opt;
 275        int *found_changesp;
 276        struct strbuf *header;
 277};
 278
 279static int count_lines(const char *data, int size)
 280{
 281        int count, ch, completely_empty = 1, nl_just_seen = 0;
 282        count = 0;
 283        while (0 < size--) {
 284                ch = *data++;
 285                if (ch == '\n') {
 286                        count++;
 287                        nl_just_seen = 1;
 288                        completely_empty = 0;
 289                }
 290                else {
 291                        nl_just_seen = 0;
 292                        completely_empty = 0;
 293                }
 294        }
 295        if (completely_empty)
 296                return 0;
 297        if (!nl_just_seen)
 298                count++; /* no trailing newline */
 299        return count;
 300}
 301
 302static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 303{
 304        if (!DIFF_FILE_VALID(one)) {
 305                mf->ptr = (char *)""; /* does not matter */
 306                mf->size = 0;
 307                return 0;
 308        }
 309        else if (diff_populate_filespec(one, 0))
 310                return -1;
 311
 312        mf->ptr = one->data;
 313        mf->size = one->size;
 314        return 0;
 315}
 316
 317/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 318static unsigned long diff_filespec_size(struct diff_filespec *one)
 319{
 320        if (!DIFF_FILE_VALID(one))
 321                return 0;
 322        diff_populate_filespec(one, 1);
 323        return one->size;
 324}
 325
 326static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 327{
 328        char *ptr = mf->ptr;
 329        long size = mf->size;
 330        int cnt = 0;
 331
 332        if (!size)
 333                return cnt;
 334        ptr += size - 1; /* pointing at the very end */
 335        if (*ptr != '\n')
 336                ; /* incomplete line */
 337        else
 338                ptr--; /* skip the last LF */
 339        while (mf->ptr < ptr) {
 340                char *prev_eol;
 341                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 342                        if (*prev_eol == '\n')
 343                                break;
 344                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 345                        break;
 346                cnt++;
 347                ptr = prev_eol - 1;
 348        }
 349        return cnt;
 350}
 351
 352static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 353                               struct emit_callback *ecbdata)
 354{
 355        int l1, l2, at;
 356        unsigned ws_rule = ecbdata->ws_rule;
 357        l1 = count_trailing_blank(mf1, ws_rule);
 358        l2 = count_trailing_blank(mf2, ws_rule);
 359        if (l2 <= l1) {
 360                ecbdata->blank_at_eof_in_preimage = 0;
 361                ecbdata->blank_at_eof_in_postimage = 0;
 362                return;
 363        }
 364        at = count_lines(mf1->ptr, mf1->size);
 365        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 366
 367        at = count_lines(mf2->ptr, mf2->size);
 368        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 369}
 370
 371static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 372                        int first, const char *line, int len)
 373{
 374        int has_trailing_newline, has_trailing_carriage_return;
 375        int nofirst;
 376        FILE *file = o->file;
 377
 378        if (o->output_prefix) {
 379                struct strbuf *msg = NULL;
 380                msg = o->output_prefix(o, o->output_prefix_data);
 381                assert(msg);
 382                fwrite(msg->buf, msg->len, 1, file);
 383        }
 384
 385        if (len == 0) {
 386                has_trailing_newline = (first == '\n');
 387                has_trailing_carriage_return = (!has_trailing_newline &&
 388                                                (first == '\r'));
 389                nofirst = has_trailing_newline || has_trailing_carriage_return;
 390        } else {
 391                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 392                if (has_trailing_newline)
 393                        len--;
 394                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 395                if (has_trailing_carriage_return)
 396                        len--;
 397                nofirst = 0;
 398        }
 399
 400        if (len || !nofirst) {
 401                fputs(set, file);
 402                if (!nofirst)
 403                        fputc(first, file);
 404                fwrite(line, len, 1, file);
 405                fputs(reset, file);
 406        }
 407        if (has_trailing_carriage_return)
 408                fputc('\r', file);
 409        if (has_trailing_newline)
 410                fputc('\n', file);
 411}
 412
 413static void emit_line(struct diff_options *o, const char *set, const char *reset,
 414                      const char *line, int len)
 415{
 416        emit_line_0(o, set, reset, line[0], line+1, len-1);
 417}
 418
 419static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 420{
 421        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 422              ecbdata->blank_at_eof_in_preimage &&
 423              ecbdata->blank_at_eof_in_postimage &&
 424              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 425              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 426                return 0;
 427        return ws_blank_line(line, len, ecbdata->ws_rule);
 428}
 429
 430static void emit_add_line(const char *reset,
 431                          struct emit_callback *ecbdata,
 432                          const char *line, int len)
 433{
 434        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 435        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 436
 437        if (!*ws)
 438                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 439        else if (new_blank_line_at_eof(ecbdata, line, len))
 440                /* Blank line at EOF - paint '+' as well */
 441                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 442        else {
 443                /* Emit just the prefix, then the rest. */
 444                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 445                ws_check_emit(line, len, ecbdata->ws_rule,
 446                              ecbdata->opt->file, set, reset, ws);
 447        }
 448}
 449
 450static void emit_hunk_header(struct emit_callback *ecbdata,
 451                             const char *line, int len)
 452{
 453        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 454        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 455        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 456        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 457        static const char atat[2] = { '@', '@' };
 458        const char *cp, *ep;
 459        struct strbuf msgbuf = STRBUF_INIT;
 460        int org_len = len;
 461        int i = 1;
 462
 463        /*
 464         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 465         * it always is at least 10 bytes long.
 466         */
 467        if (len < 10 ||
 468            memcmp(line, atat, 2) ||
 469            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 470                emit_line(ecbdata->opt, plain, reset, line, len);
 471                return;
 472        }
 473        ep += 2; /* skip over @@ */
 474
 475        /* The hunk header in fraginfo color */
 476        strbuf_add(&msgbuf, frag, strlen(frag));
 477        strbuf_add(&msgbuf, line, ep - line);
 478        strbuf_add(&msgbuf, reset, strlen(reset));
 479
 480        /*
 481         * trailing "\r\n"
 482         */
 483        for ( ; i < 3; i++)
 484                if (line[len - i] == '\r' || line[len - i] == '\n')
 485                        len--;
 486
 487        /* blank before the func header */
 488        for (cp = ep; ep - line < len; ep++)
 489                if (*ep != ' ' && *ep != '\t')
 490                        break;
 491        if (ep != cp) {
 492                strbuf_add(&msgbuf, plain, strlen(plain));
 493                strbuf_add(&msgbuf, cp, ep - cp);
 494                strbuf_add(&msgbuf, reset, strlen(reset));
 495        }
 496
 497        if (ep < line + len) {
 498                strbuf_add(&msgbuf, func, strlen(func));
 499                strbuf_add(&msgbuf, ep, line + len - ep);
 500                strbuf_add(&msgbuf, reset, strlen(reset));
 501        }
 502
 503        strbuf_add(&msgbuf, line + len, org_len - len);
 504        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 505        strbuf_release(&msgbuf);
 506}
 507
 508static struct diff_tempfile *claim_diff_tempfile(void) {
 509        int i;
 510        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 511                if (!diff_temp[i].name)
 512                        return diff_temp + i;
 513        die("BUG: diff is failing to clean up its tempfiles");
 514}
 515
 516static int remove_tempfile_installed;
 517
 518static void remove_tempfile(void)
 519{
 520        int i;
 521        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 522                if (diff_temp[i].name == diff_temp[i].tmp_path)
 523                        unlink_or_warn(diff_temp[i].name);
 524                diff_temp[i].name = NULL;
 525        }
 526}
 527
 528static void remove_tempfile_on_signal(int signo)
 529{
 530        remove_tempfile();
 531        sigchain_pop(signo);
 532        raise(signo);
 533}
 534
 535static void print_line_count(FILE *file, int count)
 536{
 537        switch (count) {
 538        case 0:
 539                fprintf(file, "0,0");
 540                break;
 541        case 1:
 542                fprintf(file, "1");
 543                break;
 544        default:
 545                fprintf(file, "1,%d", count);
 546                break;
 547        }
 548}
 549
 550static void emit_rewrite_lines(struct emit_callback *ecb,
 551                               int prefix, const char *data, int size)
 552{
 553        const char *endp = NULL;
 554        static const char *nneof = " No newline at end of file\n";
 555        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 556        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 557
 558        while (0 < size) {
 559                int len;
 560
 561                endp = memchr(data, '\n', size);
 562                len = endp ? (endp - data + 1) : size;
 563                if (prefix != '+') {
 564                        ecb->lno_in_preimage++;
 565                        emit_line_0(ecb->opt, old, reset, '-',
 566                                    data, len);
 567                } else {
 568                        ecb->lno_in_postimage++;
 569                        emit_add_line(reset, ecb, data, len);
 570                }
 571                size -= len;
 572                data += len;
 573        }
 574        if (!endp) {
 575                const char *plain = diff_get_color(ecb->color_diff,
 576                                                   DIFF_PLAIN);
 577                putc('\n', ecb->opt->file);
 578                emit_line_0(ecb->opt, plain, reset, '\\',
 579                            nneof, strlen(nneof));
 580        }
 581}
 582
 583static void emit_rewrite_diff(const char *name_a,
 584                              const char *name_b,
 585                              struct diff_filespec *one,
 586                              struct diff_filespec *two,
 587                              struct userdiff_driver *textconv_one,
 588                              struct userdiff_driver *textconv_two,
 589                              struct diff_options *o)
 590{
 591        int lc_a, lc_b;
 592        const char *name_a_tab, *name_b_tab;
 593        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 594        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 595        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 596        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 597        const char *a_prefix, *b_prefix;
 598        char *data_one, *data_two;
 599        size_t size_one, size_two;
 600        struct emit_callback ecbdata;
 601        char *line_prefix = "";
 602        struct strbuf *msgbuf;
 603
 604        if (o && o->output_prefix) {
 605                msgbuf = o->output_prefix(o, o->output_prefix_data);
 606                line_prefix = msgbuf->buf;
 607        }
 608
 609        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 610                a_prefix = o->b_prefix;
 611                b_prefix = o->a_prefix;
 612        } else {
 613                a_prefix = o->a_prefix;
 614                b_prefix = o->b_prefix;
 615        }
 616
 617        name_a += (*name_a == '/');
 618        name_b += (*name_b == '/');
 619        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 620        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 621
 622        strbuf_reset(&a_name);
 623        strbuf_reset(&b_name);
 624        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 625        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 626
 627        size_one = fill_textconv(textconv_one, one, &data_one);
 628        size_two = fill_textconv(textconv_two, two, &data_two);
 629
 630        memset(&ecbdata, 0, sizeof(ecbdata));
 631        ecbdata.color_diff = want_color(o->use_color);
 632        ecbdata.found_changesp = &o->found_changes;
 633        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 634        ecbdata.opt = o;
 635        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 636                mmfile_t mf1, mf2;
 637                mf1.ptr = (char *)data_one;
 638                mf2.ptr = (char *)data_two;
 639                mf1.size = size_one;
 640                mf2.size = size_two;
 641                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 642        }
 643        ecbdata.lno_in_preimage = 1;
 644        ecbdata.lno_in_postimage = 1;
 645
 646        lc_a = count_lines(data_one, size_one);
 647        lc_b = count_lines(data_two, size_two);
 648        fprintf(o->file,
 649                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 650                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 651                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 652                line_prefix, fraginfo);
 653        if (!o->irreversible_delete)
 654                print_line_count(o->file, lc_a);
 655        else
 656                fprintf(o->file, "?,?");
 657        fprintf(o->file, " +");
 658        print_line_count(o->file, lc_b);
 659        fprintf(o->file, " @@%s\n", reset);
 660        if (lc_a && !o->irreversible_delete)
 661                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 662        if (lc_b)
 663                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 664        if (textconv_one)
 665                free((char *)data_one);
 666        if (textconv_two)
 667                free((char *)data_two);
 668}
 669
 670struct diff_words_buffer {
 671        mmfile_t text;
 672        long alloc;
 673        struct diff_words_orig {
 674                const char *begin, *end;
 675        } *orig;
 676        int orig_nr, orig_alloc;
 677};
 678
 679static void diff_words_append(char *line, unsigned long len,
 680                struct diff_words_buffer *buffer)
 681{
 682        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 683        line++;
 684        len--;
 685        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 686        buffer->text.size += len;
 687        buffer->text.ptr[buffer->text.size] = '\0';
 688}
 689
 690struct diff_words_style_elem {
 691        const char *prefix;
 692        const char *suffix;
 693        const char *color; /* NULL; filled in by the setup code if
 694                            * color is enabled */
 695};
 696
 697struct diff_words_style {
 698        enum diff_words_type type;
 699        struct diff_words_style_elem new, old, ctx;
 700        const char *newline;
 701};
 702
 703static struct diff_words_style diff_words_styles[] = {
 704        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 705        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 706        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 707};
 708
 709struct diff_words_data {
 710        struct diff_words_buffer minus, plus;
 711        const char *current_plus;
 712        int last_minus;
 713        struct diff_options *opt;
 714        regex_t *word_regex;
 715        enum diff_words_type type;
 716        struct diff_words_style *style;
 717};
 718
 719static int fn_out_diff_words_write_helper(FILE *fp,
 720                                          struct diff_words_style_elem *st_el,
 721                                          const char *newline,
 722                                          size_t count, const char *buf,
 723                                          const char *line_prefix)
 724{
 725        int print = 0;
 726
 727        while (count) {
 728                char *p = memchr(buf, '\n', count);
 729                if (print)
 730                        fputs(line_prefix, fp);
 731                if (p != buf) {
 732                        if (st_el->color && fputs(st_el->color, fp) < 0)
 733                                return -1;
 734                        if (fputs(st_el->prefix, fp) < 0 ||
 735                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 736                            fputs(st_el->suffix, fp) < 0)
 737                                return -1;
 738                        if (st_el->color && *st_el->color
 739                            && fputs(GIT_COLOR_RESET, fp) < 0)
 740                                return -1;
 741                }
 742                if (!p)
 743                        return 0;
 744                if (fputs(newline, fp) < 0)
 745                        return -1;
 746                count -= p + 1 - buf;
 747                buf = p + 1;
 748                print = 1;
 749        }
 750        return 0;
 751}
 752
 753/*
 754 * '--color-words' algorithm can be described as:
 755 *
 756 *   1. collect a the minus/plus lines of a diff hunk, divided into
 757 *      minus-lines and plus-lines;
 758 *
 759 *   2. break both minus-lines and plus-lines into words and
 760 *      place them into two mmfile_t with one word for each line;
 761 *
 762 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 763 *
 764 * And for the common parts of the both file, we output the plus side text.
 765 * diff_words->current_plus is used to trace the current position of the plus file
 766 * which printed. diff_words->last_minus is used to trace the last minus word
 767 * printed.
 768 *
 769 * For '--graph' to work with '--color-words', we need to output the graph prefix
 770 * on each line of color words output. Generally, there are two conditions on
 771 * which we should output the prefix.
 772 *
 773 *   1. diff_words->last_minus == 0 &&
 774 *      diff_words->current_plus == diff_words->plus.text.ptr
 775 *
 776 *      that is: the plus text must start as a new line, and if there is no minus
 777 *      word printed, a graph prefix must be printed.
 778 *
 779 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 780 *      *(diff_words->current_plus - 1) == '\n'
 781 *
 782 *      that is: a graph prefix must be printed following a '\n'
 783 */
 784static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 785{
 786        if ((diff_words->last_minus == 0 &&
 787                diff_words->current_plus == diff_words->plus.text.ptr) ||
 788                (diff_words->current_plus > diff_words->plus.text.ptr &&
 789                *(diff_words->current_plus - 1) == '\n')) {
 790                return 1;
 791        } else {
 792                return 0;
 793        }
 794}
 795
 796static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 797{
 798        struct diff_words_data *diff_words = priv;
 799        struct diff_words_style *style = diff_words->style;
 800        int minus_first, minus_len, plus_first, plus_len;
 801        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 802        struct diff_options *opt = diff_words->opt;
 803        struct strbuf *msgbuf;
 804        char *line_prefix = "";
 805
 806        if (line[0] != '@' || parse_hunk_header(line, len,
 807                        &minus_first, &minus_len, &plus_first, &plus_len))
 808                return;
 809
 810        assert(opt);
 811        if (opt->output_prefix) {
 812                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 813                line_prefix = msgbuf->buf;
 814        }
 815
 816        /* POSIX requires that first be decremented by one if len == 0... */
 817        if (minus_len) {
 818                minus_begin = diff_words->minus.orig[minus_first].begin;
 819                minus_end =
 820                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 821        } else
 822                minus_begin = minus_end =
 823                        diff_words->minus.orig[minus_first].end;
 824
 825        if (plus_len) {
 826                plus_begin = diff_words->plus.orig[plus_first].begin;
 827                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 828        } else
 829                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 830
 831        if (color_words_output_graph_prefix(diff_words)) {
 832                fputs(line_prefix, diff_words->opt->file);
 833        }
 834        if (diff_words->current_plus != plus_begin) {
 835                fn_out_diff_words_write_helper(diff_words->opt->file,
 836                                &style->ctx, style->newline,
 837                                plus_begin - diff_words->current_plus,
 838                                diff_words->current_plus, line_prefix);
 839                if (*(plus_begin - 1) == '\n')
 840                        fputs(line_prefix, diff_words->opt->file);
 841        }
 842        if (minus_begin != minus_end) {
 843                fn_out_diff_words_write_helper(diff_words->opt->file,
 844                                &style->old, style->newline,
 845                                minus_end - minus_begin, minus_begin,
 846                                line_prefix);
 847        }
 848        if (plus_begin != plus_end) {
 849                fn_out_diff_words_write_helper(diff_words->opt->file,
 850                                &style->new, style->newline,
 851                                plus_end - plus_begin, plus_begin,
 852                                line_prefix);
 853        }
 854
 855        diff_words->current_plus = plus_end;
 856        diff_words->last_minus = minus_first;
 857}
 858
 859/* This function starts looking at *begin, and returns 0 iff a word was found. */
 860static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 861                int *begin, int *end)
 862{
 863        if (word_regex && *begin < buffer->size) {
 864                regmatch_t match[1];
 865                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 866                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 867                                        '\n', match[0].rm_eo - match[0].rm_so);
 868                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 869                        *begin += match[0].rm_so;
 870                        return *begin >= *end;
 871                }
 872                return -1;
 873        }
 874
 875        /* find the next word */
 876        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 877                (*begin)++;
 878        if (*begin >= buffer->size)
 879                return -1;
 880
 881        /* find the end of the word */
 882        *end = *begin + 1;
 883        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 884                (*end)++;
 885
 886        return 0;
 887}
 888
 889/*
 890 * This function splits the words in buffer->text, stores the list with
 891 * newline separator into out, and saves the offsets of the original words
 892 * in buffer->orig.
 893 */
 894static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 895                regex_t *word_regex)
 896{
 897        int i, j;
 898        long alloc = 0;
 899
 900        out->size = 0;
 901        out->ptr = NULL;
 902
 903        /* fake an empty "0th" word */
 904        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 905        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 906        buffer->orig_nr = 1;
 907
 908        for (i = 0; i < buffer->text.size; i++) {
 909                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 910                        return;
 911
 912                /* store original boundaries */
 913                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 914                                buffer->orig_alloc);
 915                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 916                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 917                buffer->orig_nr++;
 918
 919                /* store one word */
 920                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 921                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 922                out->ptr[out->size + j - i] = '\n';
 923                out->size += j - i + 1;
 924
 925                i = j - 1;
 926        }
 927}
 928
 929/* this executes the word diff on the accumulated buffers */
 930static void diff_words_show(struct diff_words_data *diff_words)
 931{
 932        xpparam_t xpp;
 933        xdemitconf_t xecfg;
 934        mmfile_t minus, plus;
 935        struct diff_words_style *style = diff_words->style;
 936
 937        struct diff_options *opt = diff_words->opt;
 938        struct strbuf *msgbuf;
 939        char *line_prefix = "";
 940
 941        assert(opt);
 942        if (opt->output_prefix) {
 943                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 944                line_prefix = msgbuf->buf;
 945        }
 946
 947        /* special case: only removal */
 948        if (!diff_words->plus.text.size) {
 949                fputs(line_prefix, diff_words->opt->file);
 950                fn_out_diff_words_write_helper(diff_words->opt->file,
 951                        &style->old, style->newline,
 952                        diff_words->minus.text.size,
 953                        diff_words->minus.text.ptr, line_prefix);
 954                diff_words->minus.text.size = 0;
 955                return;
 956        }
 957
 958        diff_words->current_plus = diff_words->plus.text.ptr;
 959        diff_words->last_minus = 0;
 960
 961        memset(&xpp, 0, sizeof(xpp));
 962        memset(&xecfg, 0, sizeof(xecfg));
 963        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 964        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 965        xpp.flags = 0;
 966        /* as only the hunk header will be parsed, we need a 0-context */
 967        xecfg.ctxlen = 0;
 968        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 969                      &xpp, &xecfg);
 970        free(minus.ptr);
 971        free(plus.ptr);
 972        if (diff_words->current_plus != diff_words->plus.text.ptr +
 973                        diff_words->plus.text.size) {
 974                if (color_words_output_graph_prefix(diff_words))
 975                        fputs(line_prefix, diff_words->opt->file);
 976                fn_out_diff_words_write_helper(diff_words->opt->file,
 977                        &style->ctx, style->newline,
 978                        diff_words->plus.text.ptr + diff_words->plus.text.size
 979                        - diff_words->current_plus, diff_words->current_plus,
 980                        line_prefix);
 981        }
 982        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 983}
 984
 985/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 986static void diff_words_flush(struct emit_callback *ecbdata)
 987{
 988        if (ecbdata->diff_words->minus.text.size ||
 989            ecbdata->diff_words->plus.text.size)
 990                diff_words_show(ecbdata->diff_words);
 991}
 992
 993static void diff_filespec_load_driver(struct diff_filespec *one)
 994{
 995        /* Use already-loaded driver */
 996        if (one->driver)
 997                return;
 998
 999        if (S_ISREG(one->mode))
1000                one->driver = userdiff_find_by_path(one->path);
1001
1002        /* Fallback to default settings */
1003        if (!one->driver)
1004                one->driver = userdiff_find_by_name("default");
1005}
1006
1007static const char *userdiff_word_regex(struct diff_filespec *one)
1008{
1009        diff_filespec_load_driver(one);
1010        return one->driver->word_regex;
1011}
1012
1013static void init_diff_words_data(struct emit_callback *ecbdata,
1014                                 struct diff_options *orig_opts,
1015                                 struct diff_filespec *one,
1016                                 struct diff_filespec *two)
1017{
1018        int i;
1019        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1020        memcpy(o, orig_opts, sizeof(struct diff_options));
1021
1022        ecbdata->diff_words =
1023                xcalloc(1, sizeof(struct diff_words_data));
1024        ecbdata->diff_words->type = o->word_diff;
1025        ecbdata->diff_words->opt = o;
1026        if (!o->word_regex)
1027                o->word_regex = userdiff_word_regex(one);
1028        if (!o->word_regex)
1029                o->word_regex = userdiff_word_regex(two);
1030        if (!o->word_regex)
1031                o->word_regex = diff_word_regex_cfg;
1032        if (o->word_regex) {
1033                ecbdata->diff_words->word_regex = (regex_t *)
1034                        xmalloc(sizeof(regex_t));
1035                if (regcomp(ecbdata->diff_words->word_regex,
1036                            o->word_regex,
1037                            REG_EXTENDED | REG_NEWLINE))
1038                        die ("Invalid regular expression: %s",
1039                             o->word_regex);
1040        }
1041        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1042                if (o->word_diff == diff_words_styles[i].type) {
1043                        ecbdata->diff_words->style =
1044                                &diff_words_styles[i];
1045                        break;
1046                }
1047        }
1048        if (want_color(o->use_color)) {
1049                struct diff_words_style *st = ecbdata->diff_words->style;
1050                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1051                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1052                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1053        }
1054}
1055
1056static void free_diff_words_data(struct emit_callback *ecbdata)
1057{
1058        if (ecbdata->diff_words) {
1059                diff_words_flush(ecbdata);
1060                free (ecbdata->diff_words->opt);
1061                free (ecbdata->diff_words->minus.text.ptr);
1062                free (ecbdata->diff_words->minus.orig);
1063                free (ecbdata->diff_words->plus.text.ptr);
1064                free (ecbdata->diff_words->plus.orig);
1065                if (ecbdata->diff_words->word_regex) {
1066                        regfree(ecbdata->diff_words->word_regex);
1067                        free(ecbdata->diff_words->word_regex);
1068                }
1069                free(ecbdata->diff_words);
1070                ecbdata->diff_words = NULL;
1071        }
1072}
1073
1074const char *diff_get_color(int diff_use_color, enum color_diff ix)
1075{
1076        if (want_color(diff_use_color))
1077                return diff_colors[ix];
1078        return "";
1079}
1080
1081static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1082{
1083        const char *cp;
1084        unsigned long allot;
1085        size_t l = len;
1086
1087        if (ecb->truncate)
1088                return ecb->truncate(line, len);
1089        cp = line;
1090        allot = l;
1091        while (0 < l) {
1092                (void) utf8_width(&cp, &l);
1093                if (!cp)
1094                        break; /* truncated in the middle? */
1095        }
1096        return allot - l;
1097}
1098
1099static void find_lno(const char *line, struct emit_callback *ecbdata)
1100{
1101        const char *p;
1102        ecbdata->lno_in_preimage = 0;
1103        ecbdata->lno_in_postimage = 0;
1104        p = strchr(line, '-');
1105        if (!p)
1106                return; /* cannot happen */
1107        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1108        p = strchr(p, '+');
1109        if (!p)
1110                return; /* cannot happen */
1111        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1112}
1113
1114static void fn_out_consume(void *priv, char *line, unsigned long len)
1115{
1116        struct emit_callback *ecbdata = priv;
1117        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1118        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1119        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1120        struct diff_options *o = ecbdata->opt;
1121        char *line_prefix = "";
1122        struct strbuf *msgbuf;
1123
1124        if (o && o->output_prefix) {
1125                msgbuf = o->output_prefix(o, o->output_prefix_data);
1126                line_prefix = msgbuf->buf;
1127        }
1128
1129        if (ecbdata->header) {
1130                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1131                strbuf_reset(ecbdata->header);
1132                ecbdata->header = NULL;
1133        }
1134        *(ecbdata->found_changesp) = 1;
1135
1136        if (ecbdata->label_path[0]) {
1137                const char *name_a_tab, *name_b_tab;
1138
1139                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1140                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1141
1142                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1143                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1144                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1145                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1146                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1147        }
1148
1149        if (diff_suppress_blank_empty
1150            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1151                line[0] = '\n';
1152                len = 1;
1153        }
1154
1155        if (line[0] == '@') {
1156                if (ecbdata->diff_words)
1157                        diff_words_flush(ecbdata);
1158                len = sane_truncate_line(ecbdata, line, len);
1159                find_lno(line, ecbdata);
1160                emit_hunk_header(ecbdata, line, len);
1161                if (line[len-1] != '\n')
1162                        putc('\n', ecbdata->opt->file);
1163                return;
1164        }
1165
1166        if (len < 1) {
1167                emit_line(ecbdata->opt, reset, reset, line, len);
1168                if (ecbdata->diff_words
1169                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1170                        fputs("~\n", ecbdata->opt->file);
1171                return;
1172        }
1173
1174        if (ecbdata->diff_words) {
1175                if (line[0] == '-') {
1176                        diff_words_append(line, len,
1177                                          &ecbdata->diff_words->minus);
1178                        return;
1179                } else if (line[0] == '+') {
1180                        diff_words_append(line, len,
1181                                          &ecbdata->diff_words->plus);
1182                        return;
1183                } else if (!prefixcmp(line, "\\ ")) {
1184                        /*
1185                         * Eat the "no newline at eof" marker as if we
1186                         * saw a "+" or "-" line with nothing on it,
1187                         * and return without diff_words_flush() to
1188                         * defer processing. If this is the end of
1189                         * preimage, more "+" lines may come after it.
1190                         */
1191                        return;
1192                }
1193                diff_words_flush(ecbdata);
1194                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1195                        emit_line(ecbdata->opt, plain, reset, line, len);
1196                        fputs("~\n", ecbdata->opt->file);
1197                } else {
1198                        /*
1199                         * Skip the prefix character, if any.  With
1200                         * diff_suppress_blank_empty, there may be
1201                         * none.
1202                         */
1203                        if (line[0] != '\n') {
1204                              line++;
1205                              len--;
1206                        }
1207                        emit_line(ecbdata->opt, plain, reset, line, len);
1208                }
1209                return;
1210        }
1211
1212        if (line[0] != '+') {
1213                const char *color =
1214                        diff_get_color(ecbdata->color_diff,
1215                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1216                ecbdata->lno_in_preimage++;
1217                if (line[0] == ' ')
1218                        ecbdata->lno_in_postimage++;
1219                emit_line(ecbdata->opt, color, reset, line, len);
1220        } else {
1221                ecbdata->lno_in_postimage++;
1222                emit_add_line(reset, ecbdata, line + 1, len - 1);
1223        }
1224}
1225
1226static char *pprint_rename(const char *a, const char *b)
1227{
1228        const char *old = a;
1229        const char *new = b;
1230        struct strbuf name = STRBUF_INIT;
1231        int pfx_length, sfx_length;
1232        int len_a = strlen(a);
1233        int len_b = strlen(b);
1234        int a_midlen, b_midlen;
1235        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1236        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1237
1238        if (qlen_a || qlen_b) {
1239                quote_c_style(a, &name, NULL, 0);
1240                strbuf_addstr(&name, " => ");
1241                quote_c_style(b, &name, NULL, 0);
1242                return strbuf_detach(&name, NULL);
1243        }
1244
1245        /* Find common prefix */
1246        pfx_length = 0;
1247        while (*old && *new && *old == *new) {
1248                if (*old == '/')
1249                        pfx_length = old - a + 1;
1250                old++;
1251                new++;
1252        }
1253
1254        /* Find common suffix */
1255        old = a + len_a;
1256        new = b + len_b;
1257        sfx_length = 0;
1258        while (a <= old && b <= new && *old == *new) {
1259                if (*old == '/')
1260                        sfx_length = len_a - (old - a);
1261                old--;
1262                new--;
1263        }
1264
1265        /*
1266         * pfx{mid-a => mid-b}sfx
1267         * {pfx-a => pfx-b}sfx
1268         * pfx{sfx-a => sfx-b}
1269         * name-a => name-b
1270         */
1271        a_midlen = len_a - pfx_length - sfx_length;
1272        b_midlen = len_b - pfx_length - sfx_length;
1273        if (a_midlen < 0)
1274                a_midlen = 0;
1275        if (b_midlen < 0)
1276                b_midlen = 0;
1277
1278        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1279        if (pfx_length + sfx_length) {
1280                strbuf_add(&name, a, pfx_length);
1281                strbuf_addch(&name, '{');
1282        }
1283        strbuf_add(&name, a + pfx_length, a_midlen);
1284        strbuf_addstr(&name, " => ");
1285        strbuf_add(&name, b + pfx_length, b_midlen);
1286        if (pfx_length + sfx_length) {
1287                strbuf_addch(&name, '}');
1288                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1289        }
1290        return strbuf_detach(&name, NULL);
1291}
1292
1293struct diffstat_t {
1294        int nr;
1295        int alloc;
1296        struct diffstat_file {
1297                char *from_name;
1298                char *name;
1299                char *print_name;
1300                unsigned is_unmerged:1;
1301                unsigned is_binary:1;
1302                unsigned is_renamed:1;
1303                uintmax_t added, deleted;
1304        } **files;
1305};
1306
1307static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1308                                          const char *name_a,
1309                                          const char *name_b)
1310{
1311        struct diffstat_file *x;
1312        x = xcalloc(sizeof (*x), 1);
1313        if (diffstat->nr == diffstat->alloc) {
1314                diffstat->alloc = alloc_nr(diffstat->alloc);
1315                diffstat->files = xrealloc(diffstat->files,
1316                                diffstat->alloc * sizeof(x));
1317        }
1318        diffstat->files[diffstat->nr++] = x;
1319        if (name_b) {
1320                x->from_name = xstrdup(name_a);
1321                x->name = xstrdup(name_b);
1322                x->is_renamed = 1;
1323        }
1324        else {
1325                x->from_name = NULL;
1326                x->name = xstrdup(name_a);
1327        }
1328        return x;
1329}
1330
1331static void diffstat_consume(void *priv, char *line, unsigned long len)
1332{
1333        struct diffstat_t *diffstat = priv;
1334        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1335
1336        if (line[0] == '+')
1337                x->added++;
1338        else if (line[0] == '-')
1339                x->deleted++;
1340}
1341
1342const char mime_boundary_leader[] = "------------";
1343
1344static int scale_linear(int it, int width, int max_change)
1345{
1346        if (!it)
1347                return 0;
1348        /*
1349         * make sure that at least one '-' or '+' is printed if
1350         * there is any change to this path. The easiest way is to
1351         * scale linearly as if the alloted width is one column shorter
1352         * than it is, and then add 1 to the result.
1353         */
1354        return 1 + (it * (width - 1) / max_change);
1355}
1356
1357static void show_name(FILE *file,
1358                      const char *prefix, const char *name, int len)
1359{
1360        fprintf(file, " %s%-*s |", prefix, len, name);
1361}
1362
1363static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1364{
1365        if (cnt <= 0)
1366                return;
1367        fprintf(file, "%s", set);
1368        while (cnt--)
1369                putc(ch, file);
1370        fprintf(file, "%s", reset);
1371}
1372
1373static void fill_print_name(struct diffstat_file *file)
1374{
1375        char *pname;
1376
1377        if (file->print_name)
1378                return;
1379
1380        if (!file->is_renamed) {
1381                struct strbuf buf = STRBUF_INIT;
1382                if (quote_c_style(file->name, &buf, NULL, 0)) {
1383                        pname = strbuf_detach(&buf, NULL);
1384                } else {
1385                        pname = file->name;
1386                        strbuf_release(&buf);
1387                }
1388        } else {
1389                pname = pprint_rename(file->from_name, file->name);
1390        }
1391        file->print_name = pname;
1392}
1393
1394int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1395{
1396        struct strbuf sb = STRBUF_INIT;
1397        int ret;
1398
1399        if (!files) {
1400                assert(insertions == 0 && deletions == 0);
1401                return fprintf(fp, "%s\n", _(" 0 files changed"));
1402        }
1403
1404        strbuf_addf(&sb,
1405                    Q_(" %d file changed", " %d files changed", files),
1406                    files);
1407
1408        /*
1409         * For binary diff, the caller may want to print "x files
1410         * changed" with insertions == 0 && deletions == 0.
1411         *
1412         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1413         * is probably less confusing (i.e skip over "2 files changed
1414         * but nothing about added/removed lines? Is this a bug in Git?").
1415         */
1416        if (insertions || deletions == 0) {
1417                /*
1418                 * TRANSLATORS: "+" in (+) is a line addition marker;
1419                 * do not translate it.
1420                 */
1421                strbuf_addf(&sb,
1422                            Q_(", %d insertion(+)", ", %d insertions(+)",
1423                               insertions),
1424                            insertions);
1425        }
1426
1427        if (deletions || insertions == 0) {
1428                /*
1429                 * TRANSLATORS: "-" in (-) is a line removal marker;
1430                 * do not translate it.
1431                 */
1432                strbuf_addf(&sb,
1433                            Q_(", %d deletion(-)", ", %d deletions(-)",
1434                               deletions),
1435                            deletions);
1436        }
1437        strbuf_addch(&sb, '\n');
1438        ret = fputs(sb.buf, fp);
1439        strbuf_release(&sb);
1440        return ret;
1441}
1442
1443static void show_stats(struct diffstat_t *data, struct diff_options *options)
1444{
1445        int i, len, add, del, adds = 0, dels = 0;
1446        uintmax_t max_change = 0, max_len = 0;
1447        int total_files = data->nr, count;
1448        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1449        const char *reset, *add_c, *del_c;
1450        const char *line_prefix = "";
1451        int extra_shown = 0;
1452        struct strbuf *msg = NULL;
1453
1454        if (data->nr == 0)
1455                return;
1456
1457        if (options->output_prefix) {
1458                msg = options->output_prefix(options, options->output_prefix_data);
1459                line_prefix = msg->buf;
1460        }
1461
1462        count = options->stat_count ? options->stat_count : data->nr;
1463
1464        reset = diff_get_color_opt(options, DIFF_RESET);
1465        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1466        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1467
1468        /*
1469         * Find the longest filename and max number of changes
1470         */
1471        for (i = 0; (i < count) && (i < data->nr); i++) {
1472                struct diffstat_file *file = data->files[i];
1473                uintmax_t change = file->added + file->deleted;
1474                if (!data->files[i]->is_renamed &&
1475                         (change == 0)) {
1476                        count++; /* not shown == room for one more */
1477                        continue;
1478                }
1479                fill_print_name(file);
1480                len = strlen(file->print_name);
1481                if (max_len < len)
1482                        max_len = len;
1483
1484                if (file->is_unmerged) {
1485                        /* "Unmerged" is 8 characters */
1486                        bin_width = bin_width < 8 ? 8 : bin_width;
1487                        continue;
1488                }
1489                if (file->is_binary) {
1490                        /* "Bin XXX -> YYY bytes" */
1491                        int w = 14 + decimal_width(file->added)
1492                                + decimal_width(file->deleted);
1493                        bin_width = bin_width < w ? w : bin_width;
1494                        /* Display change counts aligned with "Bin" */
1495                        number_width = 3;
1496                        continue;
1497                }
1498
1499                if (max_change < change)
1500                        max_change = change;
1501        }
1502        count = i; /* min(count, data->nr) */
1503
1504        /*
1505         * We have width = stat_width or term_columns() columns total.
1506         * We want a maximum of min(max_len, stat_name_width) for the name part.
1507         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1508         * We also need 1 for " " and 4 + decimal_width(max_change)
1509         * for " | NNNN " and one the empty column at the end, altogether
1510         * 6 + decimal_width(max_change).
1511         *
1512         * If there's not enough space, we will use the smaller of
1513         * stat_name_width (if set) and 5/8*width for the filename,
1514         * and the rest for constant elements + graph part, but no more
1515         * than stat_graph_width for the graph part.
1516         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1517         * for the standard terminal size).
1518         *
1519         * In other words: stat_width limits the maximum width, and
1520         * stat_name_width fixes the maximum width of the filename,
1521         * and is also used to divide available columns if there
1522         * aren't enough.
1523         *
1524         * Binary files are displayed with "Bin XXX -> YYY bytes"
1525         * instead of the change count and graph. This part is treated
1526         * similarly to the graph part, except that it is not
1527         * "scaled". If total width is too small to accomodate the
1528         * guaranteed minimum width of the filename part and the
1529         * separators and this message, this message will "overflow"
1530         * making the line longer than the maximum width.
1531         */
1532
1533        if (options->stat_width == -1)
1534                width = term_columns() - options->output_prefix_length;
1535        else
1536                width = options->stat_width ? options->stat_width : 80;
1537        number_width = decimal_width(max_change) > number_width ?
1538                decimal_width(max_change) : number_width;
1539
1540        if (options->stat_graph_width == -1)
1541                options->stat_graph_width = diff_stat_graph_width;
1542
1543        /*
1544         * Guarantee 3/8*16==6 for the graph part
1545         * and 5/8*16==10 for the filename part
1546         */
1547        if (width < 16 + 6 + number_width)
1548                width = 16 + 6 + number_width;
1549
1550        /*
1551         * First assign sizes that are wanted, ignoring available width.
1552         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1553         * starting from "XXX" should fit in graph_width.
1554         */
1555        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1556        if (options->stat_graph_width &&
1557            options->stat_graph_width < graph_width)
1558                graph_width = options->stat_graph_width;
1559
1560        name_width = (options->stat_name_width > 0 &&
1561                      options->stat_name_width < max_len) ?
1562                options->stat_name_width : max_len;
1563
1564        /*
1565         * Adjust adjustable widths not to exceed maximum width
1566         */
1567        if (name_width + number_width + 6 + graph_width > width) {
1568                if (graph_width > width * 3/8 - number_width - 6) {
1569                        graph_width = width * 3/8 - number_width - 6;
1570                        if (graph_width < 6)
1571                                graph_width = 6;
1572                }
1573
1574                if (options->stat_graph_width &&
1575                    graph_width > options->stat_graph_width)
1576                        graph_width = options->stat_graph_width;
1577                if (name_width > width - number_width - 6 - graph_width)
1578                        name_width = width - number_width - 6 - graph_width;
1579                else
1580                        graph_width = width - number_width - 6 - name_width;
1581        }
1582
1583        /*
1584         * From here name_width is the width of the name area,
1585         * and graph_width is the width of the graph area.
1586         * max_change is used to scale graph properly.
1587         */
1588        for (i = 0; i < count; i++) {
1589                const char *prefix = "";
1590                char *name = data->files[i]->print_name;
1591                uintmax_t added = data->files[i]->added;
1592                uintmax_t deleted = data->files[i]->deleted;
1593                int name_len;
1594
1595                if (!data->files[i]->is_renamed &&
1596                         (added + deleted == 0)) {
1597                        total_files--;
1598                        continue;
1599                }
1600                /*
1601                 * "scale" the filename
1602                 */
1603                len = name_width;
1604                name_len = strlen(name);
1605                if (name_width < name_len) {
1606                        char *slash;
1607                        prefix = "...";
1608                        len -= 3;
1609                        name += name_len - len;
1610                        slash = strchr(name, '/');
1611                        if (slash)
1612                                name = slash;
1613                }
1614
1615                if (data->files[i]->is_binary) {
1616                        fprintf(options->file, "%s", line_prefix);
1617                        show_name(options->file, prefix, name, len);
1618                        fprintf(options->file, " %*s", number_width, "Bin");
1619                        if (!added && !deleted) {
1620                                putc('\n', options->file);
1621                                continue;
1622                        }
1623                        fprintf(options->file, " %s%"PRIuMAX"%s",
1624                                del_c, deleted, reset);
1625                        fprintf(options->file, " -> ");
1626                        fprintf(options->file, "%s%"PRIuMAX"%s",
1627                                add_c, added, reset);
1628                        fprintf(options->file, " bytes");
1629                        fprintf(options->file, "\n");
1630                        continue;
1631                }
1632                else if (data->files[i]->is_unmerged) {
1633                        fprintf(options->file, "%s", line_prefix);
1634                        show_name(options->file, prefix, name, len);
1635                        fprintf(options->file, " Unmerged\n");
1636                        continue;
1637                }
1638
1639                /*
1640                 * scale the add/delete
1641                 */
1642                add = added;
1643                del = deleted;
1644                adds += add;
1645                dels += del;
1646
1647                if (graph_width <= max_change) {
1648                        int total = add + del;
1649
1650                        total = scale_linear(add + del, graph_width, max_change);
1651                        if (total < 2 && add && del)
1652                                /* width >= 2 due to the sanity check */
1653                                total = 2;
1654                        if (add < del) {
1655                                add = scale_linear(add, graph_width, max_change);
1656                                del = total - add;
1657                        } else {
1658                                del = scale_linear(del, graph_width, max_change);
1659                                add = total - del;
1660                        }
1661                }
1662                fprintf(options->file, "%s", line_prefix);
1663                show_name(options->file, prefix, name, len);
1664                fprintf(options->file, " %*"PRIuMAX"%s",
1665                        number_width, added + deleted,
1666                        added + deleted ? " " : "");
1667                show_graph(options->file, '+', add, add_c, reset);
1668                show_graph(options->file, '-', del, del_c, reset);
1669                fprintf(options->file, "\n");
1670        }
1671        for (i = count; i < data->nr; i++) {
1672                uintmax_t added = data->files[i]->added;
1673                uintmax_t deleted = data->files[i]->deleted;
1674                if (!data->files[i]->is_renamed &&
1675                         (added + deleted == 0)) {
1676                        total_files--;
1677                        continue;
1678                }
1679                adds += added;
1680                dels += deleted;
1681                if (!extra_shown)
1682                        fprintf(options->file, "%s ...\n", line_prefix);
1683                extra_shown = 1;
1684        }
1685        fprintf(options->file, "%s", line_prefix);
1686        print_stat_summary(options->file, total_files, adds, dels);
1687}
1688
1689static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1690{
1691        int i, adds = 0, dels = 0, total_files = data->nr;
1692
1693        if (data->nr == 0)
1694                return;
1695
1696        for (i = 0; i < data->nr; i++) {
1697                int added = data->files[i]->added;
1698                int deleted= data->files[i]->deleted;
1699
1700                if (data->files[i]->is_unmerged)
1701                        continue;
1702                if (!data->files[i]->is_renamed && (added + deleted == 0)) {
1703                        total_files--;
1704                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1705                        adds += added;
1706                        dels += deleted;
1707                }
1708        }
1709        if (options->output_prefix) {
1710                struct strbuf *msg = NULL;
1711                msg = options->output_prefix(options,
1712                                options->output_prefix_data);
1713                fprintf(options->file, "%s", msg->buf);
1714        }
1715        print_stat_summary(options->file, total_files, adds, dels);
1716}
1717
1718static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1719{
1720        int i;
1721
1722        if (data->nr == 0)
1723                return;
1724
1725        for (i = 0; i < data->nr; i++) {
1726                struct diffstat_file *file = data->files[i];
1727
1728                if (options->output_prefix) {
1729                        struct strbuf *msg = NULL;
1730                        msg = options->output_prefix(options,
1731                                        options->output_prefix_data);
1732                        fprintf(options->file, "%s", msg->buf);
1733                }
1734
1735                if (file->is_binary)
1736                        fprintf(options->file, "-\t-\t");
1737                else
1738                        fprintf(options->file,
1739                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1740                                file->added, file->deleted);
1741                if (options->line_termination) {
1742                        fill_print_name(file);
1743                        if (!file->is_renamed)
1744                                write_name_quoted(file->name, options->file,
1745                                                  options->line_termination);
1746                        else {
1747                                fputs(file->print_name, options->file);
1748                                putc(options->line_termination, options->file);
1749                        }
1750                } else {
1751                        if (file->is_renamed) {
1752                                putc('\0', options->file);
1753                                write_name_quoted(file->from_name, options->file, '\0');
1754                        }
1755                        write_name_quoted(file->name, options->file, '\0');
1756                }
1757        }
1758}
1759
1760struct dirstat_file {
1761        const char *name;
1762        unsigned long changed;
1763};
1764
1765struct dirstat_dir {
1766        struct dirstat_file *files;
1767        int alloc, nr, permille, cumulative;
1768};
1769
1770static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1771                unsigned long changed, const char *base, int baselen)
1772{
1773        unsigned long this_dir = 0;
1774        unsigned int sources = 0;
1775        const char *line_prefix = "";
1776        struct strbuf *msg = NULL;
1777
1778        if (opt->output_prefix) {
1779                msg = opt->output_prefix(opt, opt->output_prefix_data);
1780                line_prefix = msg->buf;
1781        }
1782
1783        while (dir->nr) {
1784                struct dirstat_file *f = dir->files;
1785                int namelen = strlen(f->name);
1786                unsigned long this;
1787                char *slash;
1788
1789                if (namelen < baselen)
1790                        break;
1791                if (memcmp(f->name, base, baselen))
1792                        break;
1793                slash = strchr(f->name + baselen, '/');
1794                if (slash) {
1795                        int newbaselen = slash + 1 - f->name;
1796                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1797                        sources++;
1798                } else {
1799                        this = f->changed;
1800                        dir->files++;
1801                        dir->nr--;
1802                        sources += 2;
1803                }
1804                this_dir += this;
1805        }
1806
1807        /*
1808         * We don't report dirstat's for
1809         *  - the top level
1810         *  - or cases where everything came from a single directory
1811         *    under this directory (sources == 1).
1812         */
1813        if (baselen && sources != 1) {
1814                if (this_dir) {
1815                        int permille = this_dir * 1000 / changed;
1816                        if (permille >= dir->permille) {
1817                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1818                                        permille / 10, permille % 10, baselen, base);
1819                                if (!dir->cumulative)
1820                                        return 0;
1821                        }
1822                }
1823        }
1824        return this_dir;
1825}
1826
1827static int dirstat_compare(const void *_a, const void *_b)
1828{
1829        const struct dirstat_file *a = _a;
1830        const struct dirstat_file *b = _b;
1831        return strcmp(a->name, b->name);
1832}
1833
1834static void show_dirstat(struct diff_options *options)
1835{
1836        int i;
1837        unsigned long changed;
1838        struct dirstat_dir dir;
1839        struct diff_queue_struct *q = &diff_queued_diff;
1840
1841        dir.files = NULL;
1842        dir.alloc = 0;
1843        dir.nr = 0;
1844        dir.permille = options->dirstat_permille;
1845        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1846
1847        changed = 0;
1848        for (i = 0; i < q->nr; i++) {
1849                struct diff_filepair *p = q->queue[i];
1850                const char *name;
1851                unsigned long copied, added, damage;
1852                int content_changed;
1853
1854                name = p->two->path ? p->two->path : p->one->path;
1855
1856                if (p->one->sha1_valid && p->two->sha1_valid)
1857                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1858                else
1859                        content_changed = 1;
1860
1861                if (!content_changed) {
1862                        /*
1863                         * The SHA1 has not changed, so pre-/post-content is
1864                         * identical. We can therefore skip looking at the
1865                         * file contents altogether.
1866                         */
1867                        damage = 0;
1868                        goto found_damage;
1869                }
1870
1871                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1872                        /*
1873                         * In --dirstat-by-file mode, we don't really need to
1874                         * look at the actual file contents at all.
1875                         * The fact that the SHA1 changed is enough for us to
1876                         * add this file to the list of results
1877                         * (with each file contributing equal damage).
1878                         */
1879                        damage = 1;
1880                        goto found_damage;
1881                }
1882
1883                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1884                        diff_populate_filespec(p->one, 0);
1885                        diff_populate_filespec(p->two, 0);
1886                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1887                                               &copied, &added);
1888                        diff_free_filespec_data(p->one);
1889                        diff_free_filespec_data(p->two);
1890                } else if (DIFF_FILE_VALID(p->one)) {
1891                        diff_populate_filespec(p->one, 1);
1892                        copied = added = 0;
1893                        diff_free_filespec_data(p->one);
1894                } else if (DIFF_FILE_VALID(p->two)) {
1895                        diff_populate_filespec(p->two, 1);
1896                        copied = 0;
1897                        added = p->two->size;
1898                        diff_free_filespec_data(p->two);
1899                } else
1900                        continue;
1901
1902                /*
1903                 * Original minus copied is the removed material,
1904                 * added is the new material.  They are both damages
1905                 * made to the preimage.
1906                 * If the resulting damage is zero, we know that
1907                 * diffcore_count_changes() considers the two entries to
1908                 * be identical, but since content_changed is true, we
1909                 * know that there must have been _some_ kind of change,
1910                 * so we force all entries to have damage > 0.
1911                 */
1912                damage = (p->one->size - copied) + added;
1913                if (!damage)
1914                        damage = 1;
1915
1916found_damage:
1917                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1918                dir.files[dir.nr].name = name;
1919                dir.files[dir.nr].changed = damage;
1920                changed += damage;
1921                dir.nr++;
1922        }
1923
1924        /* This can happen even with many files, if everything was renames */
1925        if (!changed)
1926                return;
1927
1928        /* Show all directories with more than x% of the changes */
1929        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1930        gather_dirstat(options, &dir, changed, "", 0);
1931}
1932
1933static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1934{
1935        int i;
1936        unsigned long changed;
1937        struct dirstat_dir dir;
1938
1939        if (data->nr == 0)
1940                return;
1941
1942        dir.files = NULL;
1943        dir.alloc = 0;
1944        dir.nr = 0;
1945        dir.permille = options->dirstat_permille;
1946        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1947
1948        changed = 0;
1949        for (i = 0; i < data->nr; i++) {
1950                struct diffstat_file *file = data->files[i];
1951                unsigned long damage = file->added + file->deleted;
1952                if (file->is_binary)
1953                        /*
1954                         * binary files counts bytes, not lines. Must find some
1955                         * way to normalize binary bytes vs. textual lines.
1956                         * The following heuristic assumes that there are 64
1957                         * bytes per "line".
1958                         * This is stupid and ugly, but very cheap...
1959                         */
1960                        damage = (damage + 63) / 64;
1961                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1962                dir.files[dir.nr].name = file->name;
1963                dir.files[dir.nr].changed = damage;
1964                changed += damage;
1965                dir.nr++;
1966        }
1967
1968        /* This can happen even with many files, if everything was renames */
1969        if (!changed)
1970                return;
1971
1972        /* Show all directories with more than x% of the changes */
1973        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1974        gather_dirstat(options, &dir, changed, "", 0);
1975}
1976
1977static void free_diffstat_info(struct diffstat_t *diffstat)
1978{
1979        int i;
1980        for (i = 0; i < diffstat->nr; i++) {
1981                struct diffstat_file *f = diffstat->files[i];
1982                if (f->name != f->print_name)
1983                        free(f->print_name);
1984                free(f->name);
1985                free(f->from_name);
1986                free(f);
1987        }
1988        free(diffstat->files);
1989}
1990
1991struct checkdiff_t {
1992        const char *filename;
1993        int lineno;
1994        int conflict_marker_size;
1995        struct diff_options *o;
1996        unsigned ws_rule;
1997        unsigned status;
1998};
1999
2000static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2001{
2002        char firstchar;
2003        int cnt;
2004
2005        if (len < marker_size + 1)
2006                return 0;
2007        firstchar = line[0];
2008        switch (firstchar) {
2009        case '=': case '>': case '<': case '|':
2010                break;
2011        default:
2012                return 0;
2013        }
2014        for (cnt = 1; cnt < marker_size; cnt++)
2015                if (line[cnt] != firstchar)
2016                        return 0;
2017        /* line[1] thru line[marker_size-1] are same as firstchar */
2018        if (len < marker_size + 1 || !isspace(line[marker_size]))
2019                return 0;
2020        return 1;
2021}
2022
2023static void checkdiff_consume(void *priv, char *line, unsigned long len)
2024{
2025        struct checkdiff_t *data = priv;
2026        int marker_size = data->conflict_marker_size;
2027        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2028        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2029        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2030        char *err;
2031        char *line_prefix = "";
2032        struct strbuf *msgbuf;
2033
2034        assert(data->o);
2035        if (data->o->output_prefix) {
2036                msgbuf = data->o->output_prefix(data->o,
2037                        data->o->output_prefix_data);
2038                line_prefix = msgbuf->buf;
2039        }
2040
2041        if (line[0] == '+') {
2042                unsigned bad;
2043                data->lineno++;
2044                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2045                        data->status |= 1;
2046                        fprintf(data->o->file,
2047                                "%s%s:%d: leftover conflict marker\n",
2048                                line_prefix, data->filename, data->lineno);
2049                }
2050                bad = ws_check(line + 1, len - 1, data->ws_rule);
2051                if (!bad)
2052                        return;
2053                data->status |= bad;
2054                err = whitespace_error_string(bad);
2055                fprintf(data->o->file, "%s%s:%d: %s.\n",
2056                        line_prefix, data->filename, data->lineno, err);
2057                free(err);
2058                emit_line(data->o, set, reset, line, 1);
2059                ws_check_emit(line + 1, len - 1, data->ws_rule,
2060                              data->o->file, set, reset, ws);
2061        } else if (line[0] == ' ') {
2062                data->lineno++;
2063        } else if (line[0] == '@') {
2064                char *plus = strchr(line, '+');
2065                if (plus)
2066                        data->lineno = strtol(plus, NULL, 10) - 1;
2067                else
2068                        die("invalid diff");
2069        }
2070}
2071
2072static unsigned char *deflate_it(char *data,
2073                                 unsigned long size,
2074                                 unsigned long *result_size)
2075{
2076        int bound;
2077        unsigned char *deflated;
2078        git_zstream stream;
2079
2080        memset(&stream, 0, sizeof(stream));
2081        git_deflate_init(&stream, zlib_compression_level);
2082        bound = git_deflate_bound(&stream, size);
2083        deflated = xmalloc(bound);
2084        stream.next_out = deflated;
2085        stream.avail_out = bound;
2086
2087        stream.next_in = (unsigned char *)data;
2088        stream.avail_in = size;
2089        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2090                ; /* nothing */
2091        git_deflate_end(&stream);
2092        *result_size = stream.total_out;
2093        return deflated;
2094}
2095
2096static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2097{
2098        void *cp;
2099        void *delta;
2100        void *deflated;
2101        void *data;
2102        unsigned long orig_size;
2103        unsigned long delta_size;
2104        unsigned long deflate_size;
2105        unsigned long data_size;
2106
2107        /* We could do deflated delta, or we could do just deflated two,
2108         * whichever is smaller.
2109         */
2110        delta = NULL;
2111        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2112        if (one->size && two->size) {
2113                delta = diff_delta(one->ptr, one->size,
2114                                   two->ptr, two->size,
2115                                   &delta_size, deflate_size);
2116                if (delta) {
2117                        void *to_free = delta;
2118                        orig_size = delta_size;
2119                        delta = deflate_it(delta, delta_size, &delta_size);
2120                        free(to_free);
2121                }
2122        }
2123
2124        if (delta && delta_size < deflate_size) {
2125                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2126                free(deflated);
2127                data = delta;
2128                data_size = delta_size;
2129        }
2130        else {
2131                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2132                free(delta);
2133                data = deflated;
2134                data_size = deflate_size;
2135        }
2136
2137        /* emit data encoded in base85 */
2138        cp = data;
2139        while (data_size) {
2140                int bytes = (52 < data_size) ? 52 : data_size;
2141                char line[70];
2142                data_size -= bytes;
2143                if (bytes <= 26)
2144                        line[0] = bytes + 'A' - 1;
2145                else
2146                        line[0] = bytes - 26 + 'a' - 1;
2147                encode_85(line + 1, cp, bytes);
2148                cp = (char *) cp + bytes;
2149                fprintf(file, "%s", prefix);
2150                fputs(line, file);
2151                fputc('\n', file);
2152        }
2153        fprintf(file, "%s\n", prefix);
2154        free(data);
2155}
2156
2157static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2158{
2159        fprintf(file, "%sGIT binary patch\n", prefix);
2160        emit_binary_diff_body(file, one, two, prefix);
2161        emit_binary_diff_body(file, two, one, prefix);
2162}
2163
2164int diff_filespec_is_binary(struct diff_filespec *one)
2165{
2166        if (one->is_binary == -1) {
2167                diff_filespec_load_driver(one);
2168                if (one->driver->binary != -1)
2169                        one->is_binary = one->driver->binary;
2170                else {
2171                        if (!one->data && DIFF_FILE_VALID(one))
2172                                diff_populate_filespec(one, 0);
2173                        if (one->data)
2174                                one->is_binary = buffer_is_binary(one->data,
2175                                                one->size);
2176                        if (one->is_binary == -1)
2177                                one->is_binary = 0;
2178                }
2179        }
2180        return one->is_binary;
2181}
2182
2183static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2184{
2185        diff_filespec_load_driver(one);
2186        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2187}
2188
2189void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2190{
2191        if (!options->a_prefix)
2192                options->a_prefix = a;
2193        if (!options->b_prefix)
2194                options->b_prefix = b;
2195}
2196
2197struct userdiff_driver *get_textconv(struct diff_filespec *one)
2198{
2199        if (!DIFF_FILE_VALID(one))
2200                return NULL;
2201
2202        diff_filespec_load_driver(one);
2203        return userdiff_get_textconv(one->driver);
2204}
2205
2206static void builtin_diff(const char *name_a,
2207                         const char *name_b,
2208                         struct diff_filespec *one,
2209                         struct diff_filespec *two,
2210                         const char *xfrm_msg,
2211                         int must_show_header,
2212                         struct diff_options *o,
2213                         int complete_rewrite)
2214{
2215        mmfile_t mf1, mf2;
2216        const char *lbl[2];
2217        char *a_one, *b_two;
2218        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2219        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2220        const char *a_prefix, *b_prefix;
2221        struct userdiff_driver *textconv_one = NULL;
2222        struct userdiff_driver *textconv_two = NULL;
2223        struct strbuf header = STRBUF_INIT;
2224        struct strbuf *msgbuf;
2225        char *line_prefix = "";
2226
2227        if (o->output_prefix) {
2228                msgbuf = o->output_prefix(o, o->output_prefix_data);
2229                line_prefix = msgbuf->buf;
2230        }
2231
2232        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2233                        (!one->mode || S_ISGITLINK(one->mode)) &&
2234                        (!two->mode || S_ISGITLINK(two->mode))) {
2235                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2236                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2237                show_submodule_summary(o->file, one ? one->path : two->path,
2238                                one->sha1, two->sha1, two->dirty_submodule,
2239                                del, add, reset);
2240                return;
2241        }
2242
2243        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2244                textconv_one = get_textconv(one);
2245                textconv_two = get_textconv(two);
2246        }
2247
2248        diff_set_mnemonic_prefix(o, "a/", "b/");
2249        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2250                a_prefix = o->b_prefix;
2251                b_prefix = o->a_prefix;
2252        } else {
2253                a_prefix = o->a_prefix;
2254                b_prefix = o->b_prefix;
2255        }
2256
2257        /* Never use a non-valid filename anywhere if at all possible */
2258        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2259        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2260
2261        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2262        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2263        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2264        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2265        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2266        if (lbl[0][0] == '/') {
2267                /* /dev/null */
2268                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2269                if (xfrm_msg)
2270                        strbuf_addstr(&header, xfrm_msg);
2271                must_show_header = 1;
2272        }
2273        else if (lbl[1][0] == '/') {
2274                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2275                if (xfrm_msg)
2276                        strbuf_addstr(&header, xfrm_msg);
2277                must_show_header = 1;
2278        }
2279        else {
2280                if (one->mode != two->mode) {
2281                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2282                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2283                        must_show_header = 1;
2284                }
2285                if (xfrm_msg)
2286                        strbuf_addstr(&header, xfrm_msg);
2287
2288                /*
2289                 * we do not run diff between different kind
2290                 * of objects.
2291                 */
2292                if ((one->mode ^ two->mode) & S_IFMT)
2293                        goto free_ab_and_return;
2294                if (complete_rewrite &&
2295                    (textconv_one || !diff_filespec_is_binary(one)) &&
2296                    (textconv_two || !diff_filespec_is_binary(two))) {
2297                        fprintf(o->file, "%s", header.buf);
2298                        strbuf_reset(&header);
2299                        emit_rewrite_diff(name_a, name_b, one, two,
2300                                                textconv_one, textconv_two, o);
2301                        o->found_changes = 1;
2302                        goto free_ab_and_return;
2303                }
2304        }
2305
2306        if (o->irreversible_delete && lbl[1][0] == '/') {
2307                fprintf(o->file, "%s", header.buf);
2308                strbuf_reset(&header);
2309                goto free_ab_and_return;
2310        } else if (!DIFF_OPT_TST(o, TEXT) &&
2311            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2312              (!textconv_two && diff_filespec_is_binary(two)) )) {
2313                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2314                        die("unable to read files to diff");
2315                /* Quite common confusing case */
2316                if (mf1.size == mf2.size &&
2317                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2318                        if (must_show_header)
2319                                fprintf(o->file, "%s", header.buf);
2320                        goto free_ab_and_return;
2321                }
2322                fprintf(o->file, "%s", header.buf);
2323                strbuf_reset(&header);
2324                if (DIFF_OPT_TST(o, BINARY))
2325                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2326                else
2327                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2328                                line_prefix, lbl[0], lbl[1]);
2329                o->found_changes = 1;
2330        } else {
2331                /* Crazy xdl interfaces.. */
2332                const char *diffopts = getenv("GIT_DIFF_OPTS");
2333                xpparam_t xpp;
2334                xdemitconf_t xecfg;
2335                struct emit_callback ecbdata;
2336                const struct userdiff_funcname *pe;
2337
2338                if (must_show_header) {
2339                        fprintf(o->file, "%s", header.buf);
2340                        strbuf_reset(&header);
2341                }
2342
2343                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2344                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2345
2346                pe = diff_funcname_pattern(one);
2347                if (!pe)
2348                        pe = diff_funcname_pattern(two);
2349
2350                memset(&xpp, 0, sizeof(xpp));
2351                memset(&xecfg, 0, sizeof(xecfg));
2352                memset(&ecbdata, 0, sizeof(ecbdata));
2353                ecbdata.label_path = lbl;
2354                ecbdata.color_diff = want_color(o->use_color);
2355                ecbdata.found_changesp = &o->found_changes;
2356                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2357                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2358                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2359                ecbdata.opt = o;
2360                ecbdata.header = header.len ? &header : NULL;
2361                xpp.flags = o->xdl_opts;
2362                xecfg.ctxlen = o->context;
2363                xecfg.interhunkctxlen = o->interhunkcontext;
2364                xecfg.flags = XDL_EMIT_FUNCNAMES;
2365                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2366                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2367                if (pe)
2368                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2369                if (!diffopts)
2370                        ;
2371                else if (!prefixcmp(diffopts, "--unified="))
2372                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2373                else if (!prefixcmp(diffopts, "-u"))
2374                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2375                if (o->word_diff)
2376                        init_diff_words_data(&ecbdata, o, one, two);
2377                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2378                              &xpp, &xecfg);
2379                if (o->word_diff)
2380                        free_diff_words_data(&ecbdata);
2381                if (textconv_one)
2382                        free(mf1.ptr);
2383                if (textconv_two)
2384                        free(mf2.ptr);
2385                xdiff_clear_find_func(&xecfg);
2386        }
2387
2388 free_ab_and_return:
2389        strbuf_release(&header);
2390        diff_free_filespec_data(one);
2391        diff_free_filespec_data(two);
2392        free(a_one);
2393        free(b_two);
2394        return;
2395}
2396
2397static void builtin_diffstat(const char *name_a, const char *name_b,
2398                             struct diff_filespec *one,
2399                             struct diff_filespec *two,
2400                             struct diffstat_t *diffstat,
2401                             struct diff_options *o,
2402                             int complete_rewrite)
2403{
2404        mmfile_t mf1, mf2;
2405        struct diffstat_file *data;
2406        int same_contents;
2407
2408        data = diffstat_add(diffstat, name_a, name_b);
2409
2410        if (!one || !two) {
2411                data->is_unmerged = 1;
2412                return;
2413        }
2414
2415        same_contents = !hashcmp(one->sha1, two->sha1);
2416
2417        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2418                data->is_binary = 1;
2419                if (same_contents) {
2420                        data->added = 0;
2421                        data->deleted = 0;
2422                } else {
2423                        data->added = diff_filespec_size(two);
2424                        data->deleted = diff_filespec_size(one);
2425                }
2426        }
2427
2428        else if (complete_rewrite) {
2429                diff_populate_filespec(one, 0);
2430                diff_populate_filespec(two, 0);
2431                data->deleted = count_lines(one->data, one->size);
2432                data->added = count_lines(two->data, two->size);
2433        }
2434
2435        else if (!same_contents) {
2436                /* Crazy xdl interfaces.. */
2437                xpparam_t xpp;
2438                xdemitconf_t xecfg;
2439
2440                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2441                        die("unable to read files to diff");
2442
2443                memset(&xpp, 0, sizeof(xpp));
2444                memset(&xecfg, 0, sizeof(xecfg));
2445                xpp.flags = o->xdl_opts;
2446                xecfg.ctxlen = o->context;
2447                xecfg.interhunkctxlen = o->interhunkcontext;
2448                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2449                              &xpp, &xecfg);
2450        }
2451
2452        diff_free_filespec_data(one);
2453        diff_free_filespec_data(two);
2454}
2455
2456static void builtin_checkdiff(const char *name_a, const char *name_b,
2457                              const char *attr_path,
2458                              struct diff_filespec *one,
2459                              struct diff_filespec *two,
2460                              struct diff_options *o)
2461{
2462        mmfile_t mf1, mf2;
2463        struct checkdiff_t data;
2464
2465        if (!two)
2466                return;
2467
2468        memset(&data, 0, sizeof(data));
2469        data.filename = name_b ? name_b : name_a;
2470        data.lineno = 0;
2471        data.o = o;
2472        data.ws_rule = whitespace_rule(attr_path);
2473        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2474
2475        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2476                die("unable to read files to diff");
2477
2478        /*
2479         * All the other codepaths check both sides, but not checking
2480         * the "old" side here is deliberate.  We are checking the newly
2481         * introduced changes, and as long as the "new" side is text, we
2482         * can and should check what it introduces.
2483         */
2484        if (diff_filespec_is_binary(two))
2485                goto free_and_return;
2486        else {
2487                /* Crazy xdl interfaces.. */
2488                xpparam_t xpp;
2489                xdemitconf_t xecfg;
2490
2491                memset(&xpp, 0, sizeof(xpp));
2492                memset(&xecfg, 0, sizeof(xecfg));
2493                xecfg.ctxlen = 1; /* at least one context line */
2494                xpp.flags = 0;
2495                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2496                              &xpp, &xecfg);
2497
2498                if (data.ws_rule & WS_BLANK_AT_EOF) {
2499                        struct emit_callback ecbdata;
2500                        int blank_at_eof;
2501
2502                        ecbdata.ws_rule = data.ws_rule;
2503                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2504                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2505
2506                        if (blank_at_eof) {
2507                                static char *err;
2508                                if (!err)
2509                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2510                                fprintf(o->file, "%s:%d: %s.\n",
2511                                        data.filename, blank_at_eof, err);
2512                                data.status = 1; /* report errors */
2513                        }
2514                }
2515        }
2516 free_and_return:
2517        diff_free_filespec_data(one);
2518        diff_free_filespec_data(two);
2519        if (data.status)
2520                DIFF_OPT_SET(o, CHECK_FAILED);
2521}
2522
2523struct diff_filespec *alloc_filespec(const char *path)
2524{
2525        int namelen = strlen(path);
2526        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2527
2528        memset(spec, 0, sizeof(*spec));
2529        spec->path = (char *)(spec + 1);
2530        memcpy(spec->path, path, namelen+1);
2531        spec->count = 1;
2532        spec->is_binary = -1;
2533        return spec;
2534}
2535
2536void free_filespec(struct diff_filespec *spec)
2537{
2538        if (!--spec->count) {
2539                diff_free_filespec_data(spec);
2540                free(spec);
2541        }
2542}
2543
2544void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2545                   int sha1_valid, unsigned short mode)
2546{
2547        if (mode) {
2548                spec->mode = canon_mode(mode);
2549                hashcpy(spec->sha1, sha1);
2550                spec->sha1_valid = sha1_valid;
2551        }
2552}
2553
2554/*
2555 * Given a name and sha1 pair, if the index tells us the file in
2556 * the work tree has that object contents, return true, so that
2557 * prepare_temp_file() does not have to inflate and extract.
2558 */
2559static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2560{
2561        struct cache_entry *ce;
2562        struct stat st;
2563        int pos, len;
2564
2565        /*
2566         * We do not read the cache ourselves here, because the
2567         * benchmark with my previous version that always reads cache
2568         * shows that it makes things worse for diff-tree comparing
2569         * two linux-2.6 kernel trees in an already checked out work
2570         * tree.  This is because most diff-tree comparisons deal with
2571         * only a small number of files, while reading the cache is
2572         * expensive for a large project, and its cost outweighs the
2573         * savings we get by not inflating the object to a temporary
2574         * file.  Practically, this code only helps when we are used
2575         * by diff-cache --cached, which does read the cache before
2576         * calling us.
2577         */
2578        if (!active_cache)
2579                return 0;
2580
2581        /* We want to avoid the working directory if our caller
2582         * doesn't need the data in a normal file, this system
2583         * is rather slow with its stat/open/mmap/close syscalls,
2584         * and the object is contained in a pack file.  The pack
2585         * is probably already open and will be faster to obtain
2586         * the data through than the working directory.  Loose
2587         * objects however would tend to be slower as they need
2588         * to be individually opened and inflated.
2589         */
2590        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2591                return 0;
2592
2593        len = strlen(name);
2594        pos = cache_name_pos(name, len);
2595        if (pos < 0)
2596                return 0;
2597        ce = active_cache[pos];
2598
2599        /*
2600         * This is not the sha1 we are looking for, or
2601         * unreusable because it is not a regular file.
2602         */
2603        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2604                return 0;
2605
2606        /*
2607         * If ce is marked as "assume unchanged", there is no
2608         * guarantee that work tree matches what we are looking for.
2609         */
2610        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2611                return 0;
2612
2613        /*
2614         * If ce matches the file in the work tree, we can reuse it.
2615         */
2616        if (ce_uptodate(ce) ||
2617            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2618                return 1;
2619
2620        return 0;
2621}
2622
2623static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2624{
2625        int len;
2626        char *data = xmalloc(100), *dirty = "";
2627
2628        /* Are we looking at the work tree? */
2629        if (s->dirty_submodule)
2630                dirty = "-dirty";
2631
2632        len = snprintf(data, 100,
2633                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2634        s->data = data;
2635        s->size = len;
2636        s->should_free = 1;
2637        if (size_only) {
2638                s->data = NULL;
2639                free(data);
2640        }
2641        return 0;
2642}
2643
2644/*
2645 * While doing rename detection and pickaxe operation, we may need to
2646 * grab the data for the blob (or file) for our own in-core comparison.
2647 * diff_filespec has data and size fields for this purpose.
2648 */
2649int diff_populate_filespec(struct diff_filespec *s, int size_only)
2650{
2651        int err = 0;
2652        if (!DIFF_FILE_VALID(s))
2653                die("internal error: asking to populate invalid file.");
2654        if (S_ISDIR(s->mode))
2655                return -1;
2656
2657        if (s->data)
2658                return 0;
2659
2660        if (size_only && 0 < s->size)
2661                return 0;
2662
2663        if (S_ISGITLINK(s->mode))
2664                return diff_populate_gitlink(s, size_only);
2665
2666        if (!s->sha1_valid ||
2667            reuse_worktree_file(s->path, s->sha1, 0)) {
2668                struct strbuf buf = STRBUF_INIT;
2669                struct stat st;
2670                int fd;
2671
2672                if (lstat(s->path, &st) < 0) {
2673                        if (errno == ENOENT) {
2674                        err_empty:
2675                                err = -1;
2676                        empty:
2677                                s->data = (char *)"";
2678                                s->size = 0;
2679                                return err;
2680                        }
2681                }
2682                s->size = xsize_t(st.st_size);
2683                if (!s->size)
2684                        goto empty;
2685                if (S_ISLNK(st.st_mode)) {
2686                        struct strbuf sb = STRBUF_INIT;
2687
2688                        if (strbuf_readlink(&sb, s->path, s->size))
2689                                goto err_empty;
2690                        s->size = sb.len;
2691                        s->data = strbuf_detach(&sb, NULL);
2692                        s->should_free = 1;
2693                        return 0;
2694                }
2695                if (size_only)
2696                        return 0;
2697                fd = open(s->path, O_RDONLY);
2698                if (fd < 0)
2699                        goto err_empty;
2700                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2701                close(fd);
2702                s->should_munmap = 1;
2703
2704                /*
2705                 * Convert from working tree format to canonical git format
2706                 */
2707                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2708                        size_t size = 0;
2709                        munmap(s->data, s->size);
2710                        s->should_munmap = 0;
2711                        s->data = strbuf_detach(&buf, &size);
2712                        s->size = size;
2713                        s->should_free = 1;
2714                }
2715        }
2716        else {
2717                enum object_type type;
2718                if (size_only) {
2719                        type = sha1_object_info(s->sha1, &s->size);
2720                        if (type < 0)
2721                                die("unable to read %s", sha1_to_hex(s->sha1));
2722                } else {
2723                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2724                        if (!s->data)
2725                                die("unable to read %s", sha1_to_hex(s->sha1));
2726                        s->should_free = 1;
2727                }
2728        }
2729        return 0;
2730}
2731
2732void diff_free_filespec_blob(struct diff_filespec *s)
2733{
2734        if (s->should_free)
2735                free(s->data);
2736        else if (s->should_munmap)
2737                munmap(s->data, s->size);
2738
2739        if (s->should_free || s->should_munmap) {
2740                s->should_free = s->should_munmap = 0;
2741                s->data = NULL;
2742        }
2743}
2744
2745void diff_free_filespec_data(struct diff_filespec *s)
2746{
2747        diff_free_filespec_blob(s);
2748        free(s->cnt_data);
2749        s->cnt_data = NULL;
2750}
2751
2752static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2753                           void *blob,
2754                           unsigned long size,
2755                           const unsigned char *sha1,
2756                           int mode)
2757{
2758        int fd;
2759        struct strbuf buf = STRBUF_INIT;
2760        struct strbuf template = STRBUF_INIT;
2761        char *path_dup = xstrdup(path);
2762        const char *base = basename(path_dup);
2763
2764        /* Generate "XXXXXX_basename.ext" */
2765        strbuf_addstr(&template, "XXXXXX_");
2766        strbuf_addstr(&template, base);
2767
2768        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2769                        strlen(base) + 1);
2770        if (fd < 0)
2771                die_errno("unable to create temp-file");
2772        if (convert_to_working_tree(path,
2773                        (const char *)blob, (size_t)size, &buf)) {
2774                blob = buf.buf;
2775                size = buf.len;
2776        }
2777        if (write_in_full(fd, blob, size) != size)
2778                die_errno("unable to write temp-file");
2779        close(fd);
2780        temp->name = temp->tmp_path;
2781        strcpy(temp->hex, sha1_to_hex(sha1));
2782        temp->hex[40] = 0;
2783        sprintf(temp->mode, "%06o", mode);
2784        strbuf_release(&buf);
2785        strbuf_release(&template);
2786        free(path_dup);
2787}
2788
2789static struct diff_tempfile *prepare_temp_file(const char *name,
2790                struct diff_filespec *one)
2791{
2792        struct diff_tempfile *temp = claim_diff_tempfile();
2793
2794        if (!DIFF_FILE_VALID(one)) {
2795        not_a_valid_file:
2796                /* A '-' entry produces this for file-2, and
2797                 * a '+' entry produces this for file-1.
2798                 */
2799                temp->name = "/dev/null";
2800                strcpy(temp->hex, ".");
2801                strcpy(temp->mode, ".");
2802                return temp;
2803        }
2804
2805        if (!remove_tempfile_installed) {
2806                atexit(remove_tempfile);
2807                sigchain_push_common(remove_tempfile_on_signal);
2808                remove_tempfile_installed = 1;
2809        }
2810
2811        if (!one->sha1_valid ||
2812            reuse_worktree_file(name, one->sha1, 1)) {
2813                struct stat st;
2814                if (lstat(name, &st) < 0) {
2815                        if (errno == ENOENT)
2816                                goto not_a_valid_file;
2817                        die_errno("stat(%s)", name);
2818                }
2819                if (S_ISLNK(st.st_mode)) {
2820                        struct strbuf sb = STRBUF_INIT;
2821                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2822                                die_errno("readlink(%s)", name);
2823                        prep_temp_blob(name, temp, sb.buf, sb.len,
2824                                       (one->sha1_valid ?
2825                                        one->sha1 : null_sha1),
2826                                       (one->sha1_valid ?
2827                                        one->mode : S_IFLNK));
2828                        strbuf_release(&sb);
2829                }
2830                else {
2831                        /* we can borrow from the file in the work tree */
2832                        temp->name = name;
2833                        if (!one->sha1_valid)
2834                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2835                        else
2836                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2837                        /* Even though we may sometimes borrow the
2838                         * contents from the work tree, we always want
2839                         * one->mode.  mode is trustworthy even when
2840                         * !(one->sha1_valid), as long as
2841                         * DIFF_FILE_VALID(one).
2842                         */
2843                        sprintf(temp->mode, "%06o", one->mode);
2844                }
2845                return temp;
2846        }
2847        else {
2848                if (diff_populate_filespec(one, 0))
2849                        die("cannot read data blob for %s", one->path);
2850                prep_temp_blob(name, temp, one->data, one->size,
2851                               one->sha1, one->mode);
2852        }
2853        return temp;
2854}
2855
2856/* An external diff command takes:
2857 *
2858 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2859 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2860 *
2861 */
2862static void run_external_diff(const char *pgm,
2863                              const char *name,
2864                              const char *other,
2865                              struct diff_filespec *one,
2866                              struct diff_filespec *two,
2867                              const char *xfrm_msg,
2868                              int complete_rewrite)
2869{
2870        const char *spawn_arg[10];
2871        int retval;
2872        const char **arg = &spawn_arg[0];
2873
2874        if (one && two) {
2875                struct diff_tempfile *temp_one, *temp_two;
2876                const char *othername = (other ? other : name);
2877                temp_one = prepare_temp_file(name, one);
2878                temp_two = prepare_temp_file(othername, two);
2879                *arg++ = pgm;
2880                *arg++ = name;
2881                *arg++ = temp_one->name;
2882                *arg++ = temp_one->hex;
2883                *arg++ = temp_one->mode;
2884                *arg++ = temp_two->name;
2885                *arg++ = temp_two->hex;
2886                *arg++ = temp_two->mode;
2887                if (other) {
2888                        *arg++ = other;
2889                        *arg++ = xfrm_msg;
2890                }
2891        } else {
2892                *arg++ = pgm;
2893                *arg++ = name;
2894        }
2895        *arg = NULL;
2896        fflush(NULL);
2897        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2898        remove_tempfile();
2899        if (retval) {
2900                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2901                exit(1);
2902        }
2903}
2904
2905static int similarity_index(struct diff_filepair *p)
2906{
2907        return p->score * 100 / MAX_SCORE;
2908}
2909
2910static void fill_metainfo(struct strbuf *msg,
2911                          const char *name,
2912                          const char *other,
2913                          struct diff_filespec *one,
2914                          struct diff_filespec *two,
2915                          struct diff_options *o,
2916                          struct diff_filepair *p,
2917                          int *must_show_header,
2918                          int use_color)
2919{
2920        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2921        const char *reset = diff_get_color(use_color, DIFF_RESET);
2922        struct strbuf *msgbuf;
2923        char *line_prefix = "";
2924
2925        *must_show_header = 1;
2926        if (o->output_prefix) {
2927                msgbuf = o->output_prefix(o, o->output_prefix_data);
2928                line_prefix = msgbuf->buf;
2929        }
2930        strbuf_init(msg, PATH_MAX * 2 + 300);
2931        switch (p->status) {
2932        case DIFF_STATUS_COPIED:
2933                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2934                            line_prefix, set, similarity_index(p));
2935                strbuf_addf(msg, "%s\n%s%scopy from ",
2936                            reset,  line_prefix, set);
2937                quote_c_style(name, msg, NULL, 0);
2938                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2939                quote_c_style(other, msg, NULL, 0);
2940                strbuf_addf(msg, "%s\n", reset);
2941                break;
2942        case DIFF_STATUS_RENAMED:
2943                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2944                            line_prefix, set, similarity_index(p));
2945                strbuf_addf(msg, "%s\n%s%srename from ",
2946                            reset, line_prefix, set);
2947                quote_c_style(name, msg, NULL, 0);
2948                strbuf_addf(msg, "%s\n%s%srename to ",
2949                            reset, line_prefix, set);
2950                quote_c_style(other, msg, NULL, 0);
2951                strbuf_addf(msg, "%s\n", reset);
2952                break;
2953        case DIFF_STATUS_MODIFIED:
2954                if (p->score) {
2955                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2956                                    line_prefix,
2957                                    set, similarity_index(p), reset);
2958                        break;
2959                }
2960                /* fallthru */
2961        default:
2962                *must_show_header = 0;
2963        }
2964        if (one && two && hashcmp(one->sha1, two->sha1)) {
2965                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2966
2967                if (DIFF_OPT_TST(o, BINARY)) {
2968                        mmfile_t mf;
2969                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2970                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2971                                abbrev = 40;
2972                }
2973                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2974                            find_unique_abbrev(one->sha1, abbrev));
2975                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2976                if (one->mode == two->mode)
2977                        strbuf_addf(msg, " %06o", one->mode);
2978                strbuf_addf(msg, "%s\n", reset);
2979        }
2980}
2981
2982static void run_diff_cmd(const char *pgm,
2983                         const char *name,
2984                         const char *other,
2985                         const char *attr_path,
2986                         struct diff_filespec *one,
2987                         struct diff_filespec *two,
2988                         struct strbuf *msg,
2989                         struct diff_options *o,
2990                         struct diff_filepair *p)
2991{
2992        const char *xfrm_msg = NULL;
2993        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2994        int must_show_header = 0;
2995
2996
2997        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
2998                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2999                if (drv && drv->external)
3000                        pgm = drv->external;
3001        }
3002
3003        if (msg) {
3004                /*
3005                 * don't use colors when the header is intended for an
3006                 * external diff driver
3007                 */
3008                fill_metainfo(msg, name, other, one, two, o, p,
3009                              &must_show_header,
3010                              want_color(o->use_color) && !pgm);
3011                xfrm_msg = msg->len ? msg->buf : NULL;
3012        }
3013
3014        if (pgm) {
3015                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3016                                  complete_rewrite);
3017                return;
3018        }
3019        if (one && two)
3020                builtin_diff(name, other ? other : name,
3021                             one, two, xfrm_msg, must_show_header,
3022                             o, complete_rewrite);
3023        else
3024                fprintf(o->file, "* Unmerged path %s\n", name);
3025}
3026
3027static void diff_fill_sha1_info(struct diff_filespec *one)
3028{
3029        if (DIFF_FILE_VALID(one)) {
3030                if (!one->sha1_valid) {
3031                        struct stat st;
3032                        if (one->is_stdin) {
3033                                hashcpy(one->sha1, null_sha1);
3034                                return;
3035                        }
3036                        if (lstat(one->path, &st) < 0)
3037                                die_errno("stat '%s'", one->path);
3038                        if (index_path(one->sha1, one->path, &st, 0))
3039                                die("cannot hash %s", one->path);
3040                }
3041        }
3042        else
3043                hashclr(one->sha1);
3044}
3045
3046static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3047{
3048        /* Strip the prefix but do not molest /dev/null and absolute paths */
3049        if (*namep && **namep != '/') {
3050                *namep += prefix_length;
3051                if (**namep == '/')
3052                        ++*namep;
3053        }
3054        if (*otherp && **otherp != '/') {
3055                *otherp += prefix_length;
3056                if (**otherp == '/')
3057                        ++*otherp;
3058        }
3059}
3060
3061static void run_diff(struct diff_filepair *p, struct diff_options *o)
3062{
3063        const char *pgm = external_diff();
3064        struct strbuf msg;
3065        struct diff_filespec *one = p->one;
3066        struct diff_filespec *two = p->two;
3067        const char *name;
3068        const char *other;
3069        const char *attr_path;
3070
3071        name  = p->one->path;
3072        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3073        attr_path = name;
3074        if (o->prefix_length)
3075                strip_prefix(o->prefix_length, &name, &other);
3076
3077        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3078                pgm = NULL;
3079
3080        if (DIFF_PAIR_UNMERGED(p)) {
3081                run_diff_cmd(pgm, name, NULL, attr_path,
3082                             NULL, NULL, NULL, o, p);
3083                return;
3084        }
3085
3086        diff_fill_sha1_info(one);
3087        diff_fill_sha1_info(two);
3088
3089        if (!pgm &&
3090            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3091            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3092                /*
3093                 * a filepair that changes between file and symlink
3094                 * needs to be split into deletion and creation.
3095                 */
3096                struct diff_filespec *null = alloc_filespec(two->path);
3097                run_diff_cmd(NULL, name, other, attr_path,
3098                             one, null, &msg, o, p);
3099                free(null);
3100                strbuf_release(&msg);
3101
3102                null = alloc_filespec(one->path);
3103                run_diff_cmd(NULL, name, other, attr_path,
3104                             null, two, &msg, o, p);
3105                free(null);
3106        }
3107        else
3108                run_diff_cmd(pgm, name, other, attr_path,
3109                             one, two, &msg, o, p);
3110
3111        strbuf_release(&msg);
3112}
3113
3114static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3115                         struct diffstat_t *diffstat)
3116{
3117        const char *name;
3118        const char *other;
3119        int complete_rewrite = 0;
3120
3121        if (DIFF_PAIR_UNMERGED(p)) {
3122                /* unmerged */
3123                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3124                return;
3125        }
3126
3127        name = p->one->path;
3128        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3129
3130        if (o->prefix_length)
3131                strip_prefix(o->prefix_length, &name, &other);
3132
3133        diff_fill_sha1_info(p->one);
3134        diff_fill_sha1_info(p->two);
3135
3136        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3137                complete_rewrite = 1;
3138        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3139}
3140
3141static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3142{
3143        const char *name;
3144        const char *other;
3145        const char *attr_path;
3146
3147        if (DIFF_PAIR_UNMERGED(p)) {
3148                /* unmerged */
3149                return;
3150        }
3151
3152        name = p->one->path;
3153        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3154        attr_path = other ? other : name;
3155
3156        if (o->prefix_length)
3157                strip_prefix(o->prefix_length, &name, &other);
3158
3159        diff_fill_sha1_info(p->one);
3160        diff_fill_sha1_info(p->two);
3161
3162        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3163}
3164
3165void diff_setup(struct diff_options *options)
3166{
3167        memcpy(options, &default_diff_options, sizeof(*options));
3168
3169        options->file = stdout;
3170
3171        options->line_termination = '\n';
3172        options->break_opt = -1;
3173        options->rename_limit = -1;
3174        options->dirstat_permille = diff_dirstat_permille_default;
3175        options->context = 3;
3176        DIFF_OPT_SET(options, RENAME_EMPTY);
3177
3178        options->change = diff_change;
3179        options->add_remove = diff_addremove;
3180        options->use_color = diff_use_color_default;
3181        options->detect_rename = diff_detect_rename_default;
3182
3183        if (diff_no_prefix) {
3184                options->a_prefix = options->b_prefix = "";
3185        } else if (!diff_mnemonic_prefix) {
3186                options->a_prefix = "a/";
3187                options->b_prefix = "b/";
3188        }
3189}
3190
3191void diff_setup_done(struct diff_options *options)
3192{
3193        int count = 0;
3194
3195        if (options->output_format & DIFF_FORMAT_NAME)
3196                count++;
3197        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3198                count++;
3199        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3200                count++;
3201        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3202                count++;
3203        if (count > 1)
3204                die("--name-only, --name-status, --check and -s are mutually exclusive");
3205
3206        /*
3207         * Most of the time we can say "there are changes"
3208         * only by checking if there are changed paths, but
3209         * --ignore-whitespace* options force us to look
3210         * inside contents.
3211         */
3212
3213        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3214            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3215            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3216                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3217        else
3218                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3219
3220        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3221                options->detect_rename = DIFF_DETECT_COPY;
3222
3223        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3224                options->prefix = NULL;
3225        if (options->prefix)
3226                options->prefix_length = strlen(options->prefix);
3227        else
3228                options->prefix_length = 0;
3229
3230        if (options->output_format & (DIFF_FORMAT_NAME |
3231                                      DIFF_FORMAT_NAME_STATUS |
3232                                      DIFF_FORMAT_CHECKDIFF |
3233                                      DIFF_FORMAT_NO_OUTPUT))
3234                options->output_format &= ~(DIFF_FORMAT_RAW |
3235                                            DIFF_FORMAT_NUMSTAT |
3236                                            DIFF_FORMAT_DIFFSTAT |
3237                                            DIFF_FORMAT_SHORTSTAT |
3238                                            DIFF_FORMAT_DIRSTAT |
3239                                            DIFF_FORMAT_SUMMARY |
3240                                            DIFF_FORMAT_PATCH);
3241
3242        /*
3243         * These cases always need recursive; we do not drop caller-supplied
3244         * recursive bits for other formats here.
3245         */
3246        if (options->output_format & (DIFF_FORMAT_PATCH |
3247                                      DIFF_FORMAT_NUMSTAT |
3248                                      DIFF_FORMAT_DIFFSTAT |
3249                                      DIFF_FORMAT_SHORTSTAT |
3250                                      DIFF_FORMAT_DIRSTAT |
3251                                      DIFF_FORMAT_SUMMARY |
3252                                      DIFF_FORMAT_CHECKDIFF))
3253                DIFF_OPT_SET(options, RECURSIVE);
3254        /*
3255         * Also pickaxe would not work very well if you do not say recursive
3256         */
3257        if (options->pickaxe)
3258                DIFF_OPT_SET(options, RECURSIVE);
3259        /*
3260         * When patches are generated, submodules diffed against the work tree
3261         * must be checked for dirtiness too so it can be shown in the output
3262         */
3263        if (options->output_format & DIFF_FORMAT_PATCH)
3264                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3265
3266        if (options->detect_rename && options->rename_limit < 0)
3267                options->rename_limit = diff_rename_limit_default;
3268        if (options->setup & DIFF_SETUP_USE_CACHE) {
3269                if (!active_cache)
3270                        /* read-cache does not die even when it fails
3271                         * so it is safe for us to do this here.  Also
3272                         * it does not smudge active_cache or active_nr
3273                         * when it fails, so we do not have to worry about
3274                         * cleaning it up ourselves either.
3275                         */
3276                        read_cache();
3277        }
3278        if (options->abbrev <= 0 || 40 < options->abbrev)
3279                options->abbrev = 40; /* full */
3280
3281        /*
3282         * It does not make sense to show the first hit we happened
3283         * to have found.  It does not make sense not to return with
3284         * exit code in such a case either.
3285         */
3286        if (DIFF_OPT_TST(options, QUICK)) {
3287                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3288                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3289        }
3290}
3291
3292static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3293{
3294        char c, *eq;
3295        int len;
3296
3297        if (*arg != '-')
3298                return 0;
3299        c = *++arg;
3300        if (!c)
3301                return 0;
3302        if (c == arg_short) {
3303                c = *++arg;
3304                if (!c)
3305                        return 1;
3306                if (val && isdigit(c)) {
3307                        char *end;
3308                        int n = strtoul(arg, &end, 10);
3309                        if (*end)
3310                                return 0;
3311                        *val = n;
3312                        return 1;
3313                }
3314                return 0;
3315        }
3316        if (c != '-')
3317                return 0;
3318        arg++;
3319        eq = strchr(arg, '=');
3320        if (eq)
3321                len = eq - arg;
3322        else
3323                len = strlen(arg);
3324        if (!len || strncmp(arg, arg_long, len))
3325                return 0;
3326        if (eq) {
3327                int n;
3328                char *end;
3329                if (!isdigit(*++eq))
3330                        return 0;
3331                n = strtoul(eq, &end, 10);
3332                if (*end)
3333                        return 0;
3334                *val = n;
3335        }
3336        return 1;
3337}
3338
3339static int diff_scoreopt_parse(const char *opt);
3340
3341static inline int short_opt(char opt, const char **argv,
3342                            const char **optarg)
3343{
3344        const char *arg = argv[0];
3345        if (arg[0] != '-' || arg[1] != opt)
3346                return 0;
3347        if (arg[2] != '\0') {
3348                *optarg = arg + 2;
3349                return 1;
3350        }
3351        if (!argv[1])
3352                die("Option '%c' requires a value", opt);
3353        *optarg = argv[1];
3354        return 2;
3355}
3356
3357int parse_long_opt(const char *opt, const char **argv,
3358                   const char **optarg)
3359{
3360        const char *arg = argv[0];
3361        if (arg[0] != '-' || arg[1] != '-')
3362                return 0;
3363        arg += strlen("--");
3364        if (prefixcmp(arg, opt))
3365                return 0;
3366        arg += strlen(opt);
3367        if (*arg == '=') { /* sticked form: --option=value */
3368                *optarg = arg + 1;
3369                return 1;
3370        }
3371        if (*arg != '\0')
3372                return 0;
3373        /* separate form: --option value */
3374        if (!argv[1])
3375                die("Option '--%s' requires a value", opt);
3376        *optarg = argv[1];
3377        return 2;
3378}
3379
3380static int stat_opt(struct diff_options *options, const char **av)
3381{
3382        const char *arg = av[0];
3383        char *end;
3384        int width = options->stat_width;
3385        int name_width = options->stat_name_width;
3386        int graph_width = options->stat_graph_width;
3387        int count = options->stat_count;
3388        int argcount = 1;
3389
3390        arg += strlen("--stat");
3391        end = (char *)arg;
3392
3393        switch (*arg) {
3394        case '-':
3395                if (!prefixcmp(arg, "-width")) {
3396                        arg += strlen("-width");
3397                        if (*arg == '=')
3398                                width = strtoul(arg + 1, &end, 10);
3399                        else if (!*arg && !av[1])
3400                                die("Option '--stat-width' requires a value");
3401                        else if (!*arg) {
3402                                width = strtoul(av[1], &end, 10);
3403                                argcount = 2;
3404                        }
3405                } else if (!prefixcmp(arg, "-name-width")) {
3406                        arg += strlen("-name-width");
3407                        if (*arg == '=')
3408                                name_width = strtoul(arg + 1, &end, 10);
3409                        else if (!*arg && !av[1])
3410                                die("Option '--stat-name-width' requires a value");
3411                        else if (!*arg) {
3412                                name_width = strtoul(av[1], &end, 10);
3413                                argcount = 2;
3414                        }
3415                } else if (!prefixcmp(arg, "-graph-width")) {
3416                        arg += strlen("-graph-width");
3417                        if (*arg == '=')
3418                                graph_width = strtoul(arg + 1, &end, 10);
3419                        else if (!*arg && !av[1])
3420                                die("Option '--stat-graph-width' requires a value");
3421                        else if (!*arg) {
3422                                graph_width = strtoul(av[1], &end, 10);
3423                                argcount = 2;
3424                        }
3425                } else if (!prefixcmp(arg, "-count")) {
3426                        arg += strlen("-count");
3427                        if (*arg == '=')
3428                                count = strtoul(arg + 1, &end, 10);
3429                        else if (!*arg && !av[1])
3430                                die("Option '--stat-count' requires a value");
3431                        else if (!*arg) {
3432                                count = strtoul(av[1], &end, 10);
3433                                argcount = 2;
3434                        }
3435                }
3436                break;
3437        case '=':
3438                width = strtoul(arg+1, &end, 10);
3439                if (*end == ',')
3440                        name_width = strtoul(end+1, &end, 10);
3441                if (*end == ',')
3442                        count = strtoul(end+1, &end, 10);
3443        }
3444
3445        /* Important! This checks all the error cases! */
3446        if (*end)
3447                return 0;
3448        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3449        options->stat_name_width = name_width;
3450        options->stat_graph_width = graph_width;
3451        options->stat_width = width;
3452        options->stat_count = count;
3453        return argcount;
3454}
3455
3456static int parse_dirstat_opt(struct diff_options *options, const char *params)
3457{
3458        struct strbuf errmsg = STRBUF_INIT;
3459        if (parse_dirstat_params(options, params, &errmsg))
3460                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3461                    errmsg.buf);
3462        strbuf_release(&errmsg);
3463        /*
3464         * The caller knows a dirstat-related option is given from the command
3465         * line; allow it to say "return this_function();"
3466         */
3467        options->output_format |= DIFF_FORMAT_DIRSTAT;
3468        return 1;
3469}
3470
3471int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3472{
3473        const char *arg = av[0];
3474        const char *optarg;
3475        int argcount;
3476
3477        /* Output format options */
3478        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3479                options->output_format |= DIFF_FORMAT_PATCH;
3480        else if (opt_arg(arg, 'U', "unified", &options->context))
3481                options->output_format |= DIFF_FORMAT_PATCH;
3482        else if (!strcmp(arg, "--raw"))
3483                options->output_format |= DIFF_FORMAT_RAW;
3484        else if (!strcmp(arg, "--patch-with-raw"))
3485                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3486        else if (!strcmp(arg, "--numstat"))
3487                options->output_format |= DIFF_FORMAT_NUMSTAT;
3488        else if (!strcmp(arg, "--shortstat"))
3489                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3490        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3491                return parse_dirstat_opt(options, "");
3492        else if (!prefixcmp(arg, "-X"))
3493                return parse_dirstat_opt(options, arg + 2);
3494        else if (!prefixcmp(arg, "--dirstat="))
3495                return parse_dirstat_opt(options, arg + 10);
3496        else if (!strcmp(arg, "--cumulative"))
3497                return parse_dirstat_opt(options, "cumulative");
3498        else if (!strcmp(arg, "--dirstat-by-file"))
3499                return parse_dirstat_opt(options, "files");
3500        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3501                parse_dirstat_opt(options, "files");
3502                return parse_dirstat_opt(options, arg + 18);
3503        }
3504        else if (!strcmp(arg, "--check"))
3505                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3506        else if (!strcmp(arg, "--summary"))
3507                options->output_format |= DIFF_FORMAT_SUMMARY;
3508        else if (!strcmp(arg, "--patch-with-stat"))
3509                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3510        else if (!strcmp(arg, "--name-only"))
3511                options->output_format |= DIFF_FORMAT_NAME;
3512        else if (!strcmp(arg, "--name-status"))
3513                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3514        else if (!strcmp(arg, "-s"))
3515                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3516        else if (!prefixcmp(arg, "--stat"))
3517                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3518                return stat_opt(options, av);
3519
3520        /* renames options */
3521        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3522                 !strcmp(arg, "--break-rewrites")) {
3523                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3524                        return error("invalid argument to -B: %s", arg+2);
3525        }
3526        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3527                 !strcmp(arg, "--find-renames")) {
3528                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3529                        return error("invalid argument to -M: %s", arg+2);
3530                options->detect_rename = DIFF_DETECT_RENAME;
3531        }
3532        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3533                options->irreversible_delete = 1;
3534        }
3535        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3536                 !strcmp(arg, "--find-copies")) {
3537                if (options->detect_rename == DIFF_DETECT_COPY)
3538                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3539                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3540                        return error("invalid argument to -C: %s", arg+2);
3541                options->detect_rename = DIFF_DETECT_COPY;
3542        }
3543        else if (!strcmp(arg, "--no-renames"))
3544                options->detect_rename = 0;
3545        else if (!strcmp(arg, "--rename-empty"))
3546                DIFF_OPT_SET(options, RENAME_EMPTY);
3547        else if (!strcmp(arg, "--no-rename-empty"))
3548                DIFF_OPT_CLR(options, RENAME_EMPTY);
3549        else if (!strcmp(arg, "--relative"))
3550                DIFF_OPT_SET(options, RELATIVE_NAME);
3551        else if (!prefixcmp(arg, "--relative=")) {
3552                DIFF_OPT_SET(options, RELATIVE_NAME);
3553                options->prefix = arg + 11;
3554        }
3555
3556        /* xdiff options */
3557        else if (!strcmp(arg, "--minimal"))
3558                DIFF_XDL_SET(options, NEED_MINIMAL);
3559        else if (!strcmp(arg, "--no-minimal"))
3560                DIFF_XDL_CLR(options, NEED_MINIMAL);
3561        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3562                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3563        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3564                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3565        else if (!strcmp(arg, "--ignore-space-at-eol"))
3566                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3567        else if (!strcmp(arg, "--patience"))
3568                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3569        else if (!strcmp(arg, "--histogram"))
3570                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3571
3572        /* flags options */
3573        else if (!strcmp(arg, "--binary")) {
3574                options->output_format |= DIFF_FORMAT_PATCH;
3575                DIFF_OPT_SET(options, BINARY);
3576        }
3577        else if (!strcmp(arg, "--full-index"))
3578                DIFF_OPT_SET(options, FULL_INDEX);
3579        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3580                DIFF_OPT_SET(options, TEXT);
3581        else if (!strcmp(arg, "-R"))
3582                DIFF_OPT_SET(options, REVERSE_DIFF);
3583        else if (!strcmp(arg, "--find-copies-harder"))
3584                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3585        else if (!strcmp(arg, "--follow"))
3586                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3587        else if (!strcmp(arg, "--color"))
3588                options->use_color = 1;
3589        else if (!prefixcmp(arg, "--color=")) {
3590                int value = git_config_colorbool(NULL, arg+8);
3591                if (value < 0)
3592                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3593                options->use_color = value;
3594        }
3595        else if (!strcmp(arg, "--no-color"))
3596                options->use_color = 0;
3597        else if (!strcmp(arg, "--color-words")) {
3598                options->use_color = 1;
3599                options->word_diff = DIFF_WORDS_COLOR;
3600        }
3601        else if (!prefixcmp(arg, "--color-words=")) {
3602                options->use_color = 1;
3603                options->word_diff = DIFF_WORDS_COLOR;
3604                options->word_regex = arg + 14;
3605        }
3606        else if (!strcmp(arg, "--word-diff")) {
3607                if (options->word_diff == DIFF_WORDS_NONE)
3608                        options->word_diff = DIFF_WORDS_PLAIN;
3609        }
3610        else if (!prefixcmp(arg, "--word-diff=")) {
3611                const char *type = arg + 12;
3612                if (!strcmp(type, "plain"))
3613                        options->word_diff = DIFF_WORDS_PLAIN;
3614                else if (!strcmp(type, "color")) {
3615                        options->use_color = 1;
3616                        options->word_diff = DIFF_WORDS_COLOR;
3617                }
3618                else if (!strcmp(type, "porcelain"))
3619                        options->word_diff = DIFF_WORDS_PORCELAIN;
3620                else if (!strcmp(type, "none"))
3621                        options->word_diff = DIFF_WORDS_NONE;
3622                else
3623                        die("bad --word-diff argument: %s", type);
3624        }
3625        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3626                if (options->word_diff == DIFF_WORDS_NONE)
3627                        options->word_diff = DIFF_WORDS_PLAIN;
3628                options->word_regex = optarg;
3629                return argcount;
3630        }
3631        else if (!strcmp(arg, "--exit-code"))
3632                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3633        else if (!strcmp(arg, "--quiet"))
3634                DIFF_OPT_SET(options, QUICK);
3635        else if (!strcmp(arg, "--ext-diff"))
3636                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3637        else if (!strcmp(arg, "--no-ext-diff"))
3638                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3639        else if (!strcmp(arg, "--textconv"))
3640                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3641        else if (!strcmp(arg, "--no-textconv"))
3642                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3643        else if (!strcmp(arg, "--ignore-submodules")) {
3644                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3645                handle_ignore_submodules_arg(options, "all");
3646        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3647                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3648                handle_ignore_submodules_arg(options, arg + 20);
3649        } else if (!strcmp(arg, "--submodule"))
3650                DIFF_OPT_SET(options, SUBMODULE_LOG);
3651        else if (!prefixcmp(arg, "--submodule=")) {
3652                if (!strcmp(arg + 12, "log"))
3653                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3654        }
3655
3656        /* misc options */
3657        else if (!strcmp(arg, "-z"))
3658                options->line_termination = 0;
3659        else if ((argcount = short_opt('l', av, &optarg))) {
3660                options->rename_limit = strtoul(optarg, NULL, 10);
3661                return argcount;
3662        }
3663        else if ((argcount = short_opt('S', av, &optarg))) {
3664                options->pickaxe = optarg;
3665                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3666                return argcount;
3667        } else if ((argcount = short_opt('G', av, &optarg))) {
3668                options->pickaxe = optarg;
3669                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3670                return argcount;
3671        }
3672        else if (!strcmp(arg, "--pickaxe-all"))
3673                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3674        else if (!strcmp(arg, "--pickaxe-regex"))
3675                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3676        else if ((argcount = short_opt('O', av, &optarg))) {
3677                options->orderfile = optarg;
3678                return argcount;
3679        }
3680        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3681                options->filter = optarg;
3682                return argcount;
3683        }
3684        else if (!strcmp(arg, "--abbrev"))
3685                options->abbrev = DEFAULT_ABBREV;
3686        else if (!prefixcmp(arg, "--abbrev=")) {
3687                options->abbrev = strtoul(arg + 9, NULL, 10);
3688                if (options->abbrev < MINIMUM_ABBREV)
3689                        options->abbrev = MINIMUM_ABBREV;
3690                else if (40 < options->abbrev)
3691                        options->abbrev = 40;
3692        }
3693        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3694                options->a_prefix = optarg;
3695                return argcount;
3696        }
3697        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3698                options->b_prefix = optarg;
3699                return argcount;
3700        }
3701        else if (!strcmp(arg, "--no-prefix"))
3702                options->a_prefix = options->b_prefix = "";
3703        else if (opt_arg(arg, '\0', "inter-hunk-context",
3704                         &options->interhunkcontext))
3705                ;
3706        else if (!strcmp(arg, "-W"))
3707                DIFF_OPT_SET(options, FUNCCONTEXT);
3708        else if (!strcmp(arg, "--function-context"))
3709                DIFF_OPT_SET(options, FUNCCONTEXT);
3710        else if (!strcmp(arg, "--no-function-context"))
3711                DIFF_OPT_CLR(options, FUNCCONTEXT);
3712        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3713                options->file = fopen(optarg, "w");
3714                if (!options->file)
3715                        die_errno("Could not open '%s'", optarg);
3716                options->close_file = 1;
3717                return argcount;
3718        } else
3719                return 0;
3720        return 1;
3721}
3722
3723int parse_rename_score(const char **cp_p)
3724{
3725        unsigned long num, scale;
3726        int ch, dot;
3727        const char *cp = *cp_p;
3728
3729        num = 0;
3730        scale = 1;
3731        dot = 0;
3732        for (;;) {
3733                ch = *cp;
3734                if ( !dot && ch == '.' ) {
3735                        scale = 1;
3736                        dot = 1;
3737                } else if ( ch == '%' ) {
3738                        scale = dot ? scale*100 : 100;
3739                        cp++;   /* % is always at the end */
3740                        break;
3741                } else if ( ch >= '0' && ch <= '9' ) {
3742                        if ( scale < 100000 ) {
3743                                scale *= 10;
3744                                num = (num*10) + (ch-'0');
3745                        }
3746                } else {
3747                        break;
3748                }
3749                cp++;
3750        }
3751        *cp_p = cp;
3752
3753        /* user says num divided by scale and we say internally that
3754         * is MAX_SCORE * num / scale.
3755         */
3756        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3757}
3758
3759static int diff_scoreopt_parse(const char *opt)
3760{
3761        int opt1, opt2, cmd;
3762
3763        if (*opt++ != '-')
3764                return -1;
3765        cmd = *opt++;
3766        if (cmd == '-') {
3767                /* convert the long-form arguments into short-form versions */
3768                if (!prefixcmp(opt, "break-rewrites")) {
3769                        opt += strlen("break-rewrites");
3770                        if (*opt == 0 || *opt++ == '=')
3771                                cmd = 'B';
3772                } else if (!prefixcmp(opt, "find-copies")) {
3773                        opt += strlen("find-copies");
3774                        if (*opt == 0 || *opt++ == '=')
3775                                cmd = 'C';
3776                } else if (!prefixcmp(opt, "find-renames")) {
3777                        opt += strlen("find-renames");
3778                        if (*opt == 0 || *opt++ == '=')
3779                                cmd = 'M';
3780                }
3781        }
3782        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3783                return -1; /* that is not a -M, -C nor -B option */
3784
3785        opt1 = parse_rename_score(&opt);
3786        if (cmd != 'B')
3787                opt2 = 0;
3788        else {
3789                if (*opt == 0)
3790                        opt2 = 0;
3791                else if (*opt != '/')
3792                        return -1; /* we expect -B80/99 or -B80 */
3793                else {
3794                        opt++;
3795                        opt2 = parse_rename_score(&opt);
3796                }
3797        }
3798        if (*opt != 0)
3799                return -1;
3800        return opt1 | (opt2 << 16);
3801}
3802
3803struct diff_queue_struct diff_queued_diff;
3804
3805void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3806{
3807        if (queue->alloc <= queue->nr) {
3808                queue->alloc = alloc_nr(queue->alloc);
3809                queue->queue = xrealloc(queue->queue,
3810                                        sizeof(dp) * queue->alloc);
3811        }
3812        queue->queue[queue->nr++] = dp;
3813}
3814
3815struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3816                                 struct diff_filespec *one,
3817                                 struct diff_filespec *two)
3818{
3819        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3820        dp->one = one;
3821        dp->two = two;
3822        if (queue)
3823                diff_q(queue, dp);
3824        return dp;
3825}
3826
3827void diff_free_filepair(struct diff_filepair *p)
3828{
3829        free_filespec(p->one);
3830        free_filespec(p->two);
3831        free(p);
3832}
3833
3834/* This is different from find_unique_abbrev() in that
3835 * it stuffs the result with dots for alignment.
3836 */
3837const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3838{
3839        int abblen;
3840        const char *abbrev;
3841        if (len == 40)
3842                return sha1_to_hex(sha1);
3843
3844        abbrev = find_unique_abbrev(sha1, len);
3845        abblen = strlen(abbrev);
3846        if (abblen < 37) {
3847                static char hex[41];
3848                if (len < abblen && abblen <= len + 2)
3849                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3850                else
3851                        sprintf(hex, "%s...", abbrev);
3852                return hex;
3853        }
3854        return sha1_to_hex(sha1);
3855}
3856
3857static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3858{
3859        int line_termination = opt->line_termination;
3860        int inter_name_termination = line_termination ? '\t' : '\0';
3861        if (opt->output_prefix) {
3862                struct strbuf *msg = NULL;
3863                msg = opt->output_prefix(opt, opt->output_prefix_data);
3864                fprintf(opt->file, "%s", msg->buf);
3865        }
3866
3867        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3868                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3869                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3870                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3871        }
3872        if (p->score) {
3873                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3874                        inter_name_termination);
3875        } else {
3876                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3877        }
3878
3879        if (p->status == DIFF_STATUS_COPIED ||
3880            p->status == DIFF_STATUS_RENAMED) {
3881                const char *name_a, *name_b;
3882                name_a = p->one->path;
3883                name_b = p->two->path;
3884                strip_prefix(opt->prefix_length, &name_a, &name_b);
3885                write_name_quoted(name_a, opt->file, inter_name_termination);
3886                write_name_quoted(name_b, opt->file, line_termination);
3887        } else {
3888                const char *name_a, *name_b;
3889                name_a = p->one->mode ? p->one->path : p->two->path;
3890                name_b = NULL;
3891                strip_prefix(opt->prefix_length, &name_a, &name_b);
3892                write_name_quoted(name_a, opt->file, line_termination);
3893        }
3894}
3895
3896int diff_unmodified_pair(struct diff_filepair *p)
3897{
3898        /* This function is written stricter than necessary to support
3899         * the currently implemented transformers, but the idea is to
3900         * let transformers to produce diff_filepairs any way they want,
3901         * and filter and clean them up here before producing the output.
3902         */
3903        struct diff_filespec *one = p->one, *two = p->two;
3904
3905        if (DIFF_PAIR_UNMERGED(p))
3906                return 0; /* unmerged is interesting */
3907
3908        /* deletion, addition, mode or type change
3909         * and rename are all interesting.
3910         */
3911        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3912            DIFF_PAIR_MODE_CHANGED(p) ||
3913            strcmp(one->path, two->path))
3914                return 0;
3915
3916        /* both are valid and point at the same path.  that is, we are
3917         * dealing with a change.
3918         */
3919        if (one->sha1_valid && two->sha1_valid &&
3920            !hashcmp(one->sha1, two->sha1) &&
3921            !one->dirty_submodule && !two->dirty_submodule)
3922                return 1; /* no change */
3923        if (!one->sha1_valid && !two->sha1_valid)
3924                return 1; /* both look at the same file on the filesystem. */
3925        return 0;
3926}
3927
3928static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3929{
3930        if (diff_unmodified_pair(p))
3931                return;
3932
3933        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3934            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3935                return; /* no tree diffs in patch format */
3936
3937        run_diff(p, o);
3938}
3939
3940static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3941                            struct diffstat_t *diffstat)
3942{
3943        if (diff_unmodified_pair(p))
3944                return;
3945
3946        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3947            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3948                return; /* no useful stat for tree diffs */
3949
3950        run_diffstat(p, o, diffstat);
3951}
3952
3953static void diff_flush_checkdiff(struct diff_filepair *p,
3954                struct diff_options *o)
3955{
3956        if (diff_unmodified_pair(p))
3957                return;
3958
3959        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3960            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3961                return; /* nothing to check in tree diffs */
3962
3963        run_checkdiff(p, o);
3964}
3965
3966int diff_queue_is_empty(void)
3967{
3968        struct diff_queue_struct *q = &diff_queued_diff;
3969        int i;
3970        for (i = 0; i < q->nr; i++)
3971                if (!diff_unmodified_pair(q->queue[i]))
3972                        return 0;
3973        return 1;
3974}
3975
3976#if DIFF_DEBUG
3977void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3978{
3979        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3980                x, one ? one : "",
3981                s->path,
3982                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3983                s->mode,
3984                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3985        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3986                x, one ? one : "",
3987                s->size, s->xfrm_flags);
3988}
3989
3990void diff_debug_filepair(const struct diff_filepair *p, int i)
3991{
3992        diff_debug_filespec(p->one, i, "one");
3993        diff_debug_filespec(p->two, i, "two");
3994        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3995                p->score, p->status ? p->status : '?',
3996                p->one->rename_used, p->broken_pair);
3997}
3998
3999void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4000{
4001        int i;
4002        if (msg)
4003                fprintf(stderr, "%s\n", msg);
4004        fprintf(stderr, "q->nr = %d\n", q->nr);
4005        for (i = 0; i < q->nr; i++) {
4006                struct diff_filepair *p = q->queue[i];
4007                diff_debug_filepair(p, i);
4008        }
4009}
4010#endif
4011
4012static void diff_resolve_rename_copy(void)
4013{
4014        int i;
4015        struct diff_filepair *p;
4016        struct diff_queue_struct *q = &diff_queued_diff;
4017
4018        diff_debug_queue("resolve-rename-copy", q);
4019
4020        for (i = 0; i < q->nr; i++) {
4021                p = q->queue[i];
4022                p->status = 0; /* undecided */
4023                if (DIFF_PAIR_UNMERGED(p))
4024                        p->status = DIFF_STATUS_UNMERGED;
4025                else if (!DIFF_FILE_VALID(p->one))
4026                        p->status = DIFF_STATUS_ADDED;
4027                else if (!DIFF_FILE_VALID(p->two))
4028                        p->status = DIFF_STATUS_DELETED;
4029                else if (DIFF_PAIR_TYPE_CHANGED(p))
4030                        p->status = DIFF_STATUS_TYPE_CHANGED;
4031
4032                /* from this point on, we are dealing with a pair
4033                 * whose both sides are valid and of the same type, i.e.
4034                 * either in-place edit or rename/copy edit.
4035                 */
4036                else if (DIFF_PAIR_RENAME(p)) {
4037                        /*
4038                         * A rename might have re-connected a broken
4039                         * pair up, causing the pathnames to be the
4040                         * same again. If so, that's not a rename at
4041                         * all, just a modification..
4042                         *
4043                         * Otherwise, see if this source was used for
4044                         * multiple renames, in which case we decrement
4045                         * the count, and call it a copy.
4046                         */
4047                        if (!strcmp(p->one->path, p->two->path))
4048                                p->status = DIFF_STATUS_MODIFIED;
4049                        else if (--p->one->rename_used > 0)
4050                                p->status = DIFF_STATUS_COPIED;
4051                        else
4052                                p->status = DIFF_STATUS_RENAMED;
4053                }
4054                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4055                         p->one->mode != p->two->mode ||
4056                         p->one->dirty_submodule ||
4057                         p->two->dirty_submodule ||
4058                         is_null_sha1(p->one->sha1))
4059                        p->status = DIFF_STATUS_MODIFIED;
4060                else {
4061                        /* This is a "no-change" entry and should not
4062                         * happen anymore, but prepare for broken callers.
4063                         */
4064                        error("feeding unmodified %s to diffcore",
4065                              p->one->path);
4066                        p->status = DIFF_STATUS_UNKNOWN;
4067                }
4068        }
4069        diff_debug_queue("resolve-rename-copy done", q);
4070}
4071
4072static int check_pair_status(struct diff_filepair *p)
4073{
4074        switch (p->status) {
4075        case DIFF_STATUS_UNKNOWN:
4076                return 0;
4077        case 0:
4078                die("internal error in diff-resolve-rename-copy");
4079        default:
4080                return 1;
4081        }
4082}
4083
4084static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4085{
4086        int fmt = opt->output_format;
4087
4088        if (fmt & DIFF_FORMAT_CHECKDIFF)
4089                diff_flush_checkdiff(p, opt);
4090        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4091                diff_flush_raw(p, opt);
4092        else if (fmt & DIFF_FORMAT_NAME) {
4093                const char *name_a, *name_b;
4094                name_a = p->two->path;
4095                name_b = NULL;
4096                strip_prefix(opt->prefix_length, &name_a, &name_b);
4097                write_name_quoted(name_a, opt->file, opt->line_termination);
4098        }
4099}
4100
4101static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4102{
4103        if (fs->mode)
4104                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4105        else
4106                fprintf(file, " %s ", newdelete);
4107        write_name_quoted(fs->path, file, '\n');
4108}
4109
4110
4111static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4112                const char *line_prefix)
4113{
4114        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4115                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4116                        p->two->mode, show_name ? ' ' : '\n');
4117                if (show_name) {
4118                        write_name_quoted(p->two->path, file, '\n');
4119                }
4120        }
4121}
4122
4123static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4124                        const char *line_prefix)
4125{
4126        char *names = pprint_rename(p->one->path, p->two->path);
4127
4128        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4129        free(names);
4130        show_mode_change(file, p, 0, line_prefix);
4131}
4132
4133static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4134{
4135        FILE *file = opt->file;
4136        char *line_prefix = "";
4137
4138        if (opt->output_prefix) {
4139                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4140                line_prefix = buf->buf;
4141        }
4142
4143        switch(p->status) {
4144        case DIFF_STATUS_DELETED:
4145                fputs(line_prefix, file);
4146                show_file_mode_name(file, "delete", p->one);
4147                break;
4148        case DIFF_STATUS_ADDED:
4149                fputs(line_prefix, file);
4150                show_file_mode_name(file, "create", p->two);
4151                break;
4152        case DIFF_STATUS_COPIED:
4153                fputs(line_prefix, file);
4154                show_rename_copy(file, "copy", p, line_prefix);
4155                break;
4156        case DIFF_STATUS_RENAMED:
4157                fputs(line_prefix, file);
4158                show_rename_copy(file, "rename", p, line_prefix);
4159                break;
4160        default:
4161                if (p->score) {
4162                        fprintf(file, "%s rewrite ", line_prefix);
4163                        write_name_quoted(p->two->path, file, ' ');
4164                        fprintf(file, "(%d%%)\n", similarity_index(p));
4165                }
4166                show_mode_change(file, p, !p->score, line_prefix);
4167                break;
4168        }
4169}
4170
4171struct patch_id_t {
4172        git_SHA_CTX *ctx;
4173        int patchlen;
4174};
4175
4176static int remove_space(char *line, int len)
4177{
4178        int i;
4179        char *dst = line;
4180        unsigned char c;
4181
4182        for (i = 0; i < len; i++)
4183                if (!isspace((c = line[i])))
4184                        *dst++ = c;
4185
4186        return dst - line;
4187}
4188
4189static void patch_id_consume(void *priv, char *line, unsigned long len)
4190{
4191        struct patch_id_t *data = priv;
4192        int new_len;
4193
4194        /* Ignore line numbers when computing the SHA1 of the patch */
4195        if (!prefixcmp(line, "@@ -"))
4196                return;
4197
4198        new_len = remove_space(line, len);
4199
4200        git_SHA1_Update(data->ctx, line, new_len);
4201        data->patchlen += new_len;
4202}
4203
4204/* returns 0 upon success, and writes result into sha1 */
4205static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4206{
4207        struct diff_queue_struct *q = &diff_queued_diff;
4208        int i;
4209        git_SHA_CTX ctx;
4210        struct patch_id_t data;
4211        char buffer[PATH_MAX * 4 + 20];
4212
4213        git_SHA1_Init(&ctx);
4214        memset(&data, 0, sizeof(struct patch_id_t));
4215        data.ctx = &ctx;
4216
4217        for (i = 0; i < q->nr; i++) {
4218                xpparam_t xpp;
4219                xdemitconf_t xecfg;
4220                mmfile_t mf1, mf2;
4221                struct diff_filepair *p = q->queue[i];
4222                int len1, len2;
4223
4224                memset(&xpp, 0, sizeof(xpp));
4225                memset(&xecfg, 0, sizeof(xecfg));
4226                if (p->status == 0)
4227                        return error("internal diff status error");
4228                if (p->status == DIFF_STATUS_UNKNOWN)
4229                        continue;
4230                if (diff_unmodified_pair(p))
4231                        continue;
4232                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4233                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4234                        continue;
4235                if (DIFF_PAIR_UNMERGED(p))
4236                        continue;
4237
4238                diff_fill_sha1_info(p->one);
4239                diff_fill_sha1_info(p->two);
4240                if (fill_mmfile(&mf1, p->one) < 0 ||
4241                                fill_mmfile(&mf2, p->two) < 0)
4242                        return error("unable to read files to diff");
4243
4244                len1 = remove_space(p->one->path, strlen(p->one->path));
4245                len2 = remove_space(p->two->path, strlen(p->two->path));
4246                if (p->one->mode == 0)
4247                        len1 = snprintf(buffer, sizeof(buffer),
4248                                        "diff--gita/%.*sb/%.*s"
4249                                        "newfilemode%06o"
4250                                        "---/dev/null"
4251                                        "+++b/%.*s",
4252                                        len1, p->one->path,
4253                                        len2, p->two->path,
4254                                        p->two->mode,
4255                                        len2, p->two->path);
4256                else if (p->two->mode == 0)
4257                        len1 = snprintf(buffer, sizeof(buffer),
4258                                        "diff--gita/%.*sb/%.*s"
4259                                        "deletedfilemode%06o"
4260                                        "---a/%.*s"
4261                                        "+++/dev/null",
4262                                        len1, p->one->path,
4263                                        len2, p->two->path,
4264                                        p->one->mode,
4265                                        len1, p->one->path);
4266                else
4267                        len1 = snprintf(buffer, sizeof(buffer),
4268                                        "diff--gita/%.*sb/%.*s"
4269                                        "---a/%.*s"
4270                                        "+++b/%.*s",
4271                                        len1, p->one->path,
4272                                        len2, p->two->path,
4273                                        len1, p->one->path,
4274                                        len2, p->two->path);
4275                git_SHA1_Update(&ctx, buffer, len1);
4276
4277                if (diff_filespec_is_binary(p->one) ||
4278                    diff_filespec_is_binary(p->two)) {
4279                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4280                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4281                        continue;
4282                }
4283
4284                xpp.flags = 0;
4285                xecfg.ctxlen = 3;
4286                xecfg.flags = 0;
4287                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4288                              &xpp, &xecfg);
4289        }
4290
4291        git_SHA1_Final(sha1, &ctx);
4292        return 0;
4293}
4294
4295int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4296{
4297        struct diff_queue_struct *q = &diff_queued_diff;
4298        int i;
4299        int result = diff_get_patch_id(options, sha1);
4300
4301        for (i = 0; i < q->nr; i++)
4302                diff_free_filepair(q->queue[i]);
4303
4304        free(q->queue);
4305        DIFF_QUEUE_CLEAR(q);
4306
4307        return result;
4308}
4309
4310static int is_summary_empty(const struct diff_queue_struct *q)
4311{
4312        int i;
4313
4314        for (i = 0; i < q->nr; i++) {
4315                const struct diff_filepair *p = q->queue[i];
4316
4317                switch (p->status) {
4318                case DIFF_STATUS_DELETED:
4319                case DIFF_STATUS_ADDED:
4320                case DIFF_STATUS_COPIED:
4321                case DIFF_STATUS_RENAMED:
4322                        return 0;
4323                default:
4324                        if (p->score)
4325                                return 0;
4326                        if (p->one->mode && p->two->mode &&
4327                            p->one->mode != p->two->mode)
4328                                return 0;
4329                        break;
4330                }
4331        }
4332        return 1;
4333}
4334
4335static const char rename_limit_warning[] =
4336"inexact rename detection was skipped due to too many files.";
4337
4338static const char degrade_cc_to_c_warning[] =
4339"only found copies from modified paths due to too many files.";
4340
4341static const char rename_limit_advice[] =
4342"you may want to set your %s variable to at least "
4343"%d and retry the command.";
4344
4345void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4346{
4347        if (degraded_cc)
4348                warning(degrade_cc_to_c_warning);
4349        else if (needed)
4350                warning(rename_limit_warning);
4351        else
4352                return;
4353        if (0 < needed && needed < 32767)
4354                warning(rename_limit_advice, varname, needed);
4355}
4356
4357void diff_flush(struct diff_options *options)
4358{
4359        struct diff_queue_struct *q = &diff_queued_diff;
4360        int i, output_format = options->output_format;
4361        int separator = 0;
4362        int dirstat_by_line = 0;
4363
4364        /*
4365         * Order: raw, stat, summary, patch
4366         * or:    name/name-status/checkdiff (other bits clear)
4367         */
4368        if (!q->nr)
4369                goto free_queue;
4370
4371        if (output_format & (DIFF_FORMAT_RAW |
4372                             DIFF_FORMAT_NAME |
4373                             DIFF_FORMAT_NAME_STATUS |
4374                             DIFF_FORMAT_CHECKDIFF)) {
4375                for (i = 0; i < q->nr; i++) {
4376                        struct diff_filepair *p = q->queue[i];
4377                        if (check_pair_status(p))
4378                                flush_one_pair(p, options);
4379                }
4380                separator++;
4381        }
4382
4383        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4384                dirstat_by_line = 1;
4385
4386        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4387            dirstat_by_line) {
4388                struct diffstat_t diffstat;
4389
4390                memset(&diffstat, 0, sizeof(struct diffstat_t));
4391                for (i = 0; i < q->nr; i++) {
4392                        struct diff_filepair *p = q->queue[i];
4393                        if (check_pair_status(p))
4394                                diff_flush_stat(p, options, &diffstat);
4395                }
4396                if (output_format & DIFF_FORMAT_NUMSTAT)
4397                        show_numstat(&diffstat, options);
4398                if (output_format & DIFF_FORMAT_DIFFSTAT)
4399                        show_stats(&diffstat, options);
4400                if (output_format & DIFF_FORMAT_SHORTSTAT)
4401                        show_shortstats(&diffstat, options);
4402                if (output_format & DIFF_FORMAT_DIRSTAT)
4403                        show_dirstat_by_line(&diffstat, options);
4404                free_diffstat_info(&diffstat);
4405                separator++;
4406        }
4407        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4408                show_dirstat(options);
4409
4410        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4411                for (i = 0; i < q->nr; i++) {
4412                        diff_summary(options, q->queue[i]);
4413                }
4414                separator++;
4415        }
4416
4417        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4418            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4419            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4420                /*
4421                 * run diff_flush_patch for the exit status. setting
4422                 * options->file to /dev/null should be safe, becaue we
4423                 * aren't supposed to produce any output anyway.
4424                 */
4425                if (options->close_file)
4426                        fclose(options->file);
4427                options->file = fopen("/dev/null", "w");
4428                if (!options->file)
4429                        die_errno("Could not open /dev/null");
4430                options->close_file = 1;
4431                for (i = 0; i < q->nr; i++) {
4432                        struct diff_filepair *p = q->queue[i];
4433                        if (check_pair_status(p))
4434                                diff_flush_patch(p, options);
4435                        if (options->found_changes)
4436                                break;
4437                }
4438        }
4439
4440        if (output_format & DIFF_FORMAT_PATCH) {
4441                if (separator) {
4442                        if (options->output_prefix) {
4443                                struct strbuf *msg = NULL;
4444                                msg = options->output_prefix(options,
4445                                        options->output_prefix_data);
4446                                fwrite(msg->buf, msg->len, 1, stdout);
4447                        }
4448                        putc(options->line_termination, options->file);
4449                        if (options->stat_sep) {
4450                                /* attach patch instead of inline */
4451                                fputs(options->stat_sep, options->file);
4452                        }
4453                }
4454
4455                for (i = 0; i < q->nr; i++) {
4456                        struct diff_filepair *p = q->queue[i];
4457                        if (check_pair_status(p))
4458                                diff_flush_patch(p, options);
4459                }
4460        }
4461
4462        if (output_format & DIFF_FORMAT_CALLBACK)
4463                options->format_callback(q, options, options->format_callback_data);
4464
4465        for (i = 0; i < q->nr; i++)
4466                diff_free_filepair(q->queue[i]);
4467free_queue:
4468        free(q->queue);
4469        DIFF_QUEUE_CLEAR(q);
4470        if (options->close_file)
4471                fclose(options->file);
4472
4473        /*
4474         * Report the content-level differences with HAS_CHANGES;
4475         * diff_addremove/diff_change does not set the bit when
4476         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4477         */
4478        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4479                if (options->found_changes)
4480                        DIFF_OPT_SET(options, HAS_CHANGES);
4481                else
4482                        DIFF_OPT_CLR(options, HAS_CHANGES);
4483        }
4484}
4485
4486static void diffcore_apply_filter(const char *filter)
4487{
4488        int i;
4489        struct diff_queue_struct *q = &diff_queued_diff;
4490        struct diff_queue_struct outq;
4491        DIFF_QUEUE_CLEAR(&outq);
4492
4493        if (!filter)
4494                return;
4495
4496        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4497                int found;
4498                for (i = found = 0; !found && i < q->nr; i++) {
4499                        struct diff_filepair *p = q->queue[i];
4500                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4501                             ((p->score &&
4502                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4503                              (!p->score &&
4504                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4505                            ((p->status != DIFF_STATUS_MODIFIED) &&
4506                             strchr(filter, p->status)))
4507                                found++;
4508                }
4509                if (found)
4510                        return;
4511
4512                /* otherwise we will clear the whole queue
4513                 * by copying the empty outq at the end of this
4514                 * function, but first clear the current entries
4515                 * in the queue.
4516                 */
4517                for (i = 0; i < q->nr; i++)
4518                        diff_free_filepair(q->queue[i]);
4519        }
4520        else {
4521                /* Only the matching ones */
4522                for (i = 0; i < q->nr; i++) {
4523                        struct diff_filepair *p = q->queue[i];
4524
4525                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4526                             ((p->score &&
4527                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4528                              (!p->score &&
4529                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4530                            ((p->status != DIFF_STATUS_MODIFIED) &&
4531                             strchr(filter, p->status)))
4532                                diff_q(&outq, p);
4533                        else
4534                                diff_free_filepair(p);
4535                }
4536        }
4537        free(q->queue);
4538        *q = outq;
4539}
4540
4541/* Check whether two filespecs with the same mode and size are identical */
4542static int diff_filespec_is_identical(struct diff_filespec *one,
4543                                      struct diff_filespec *two)
4544{
4545        if (S_ISGITLINK(one->mode))
4546                return 0;
4547        if (diff_populate_filespec(one, 0))
4548                return 0;
4549        if (diff_populate_filespec(two, 0))
4550                return 0;
4551        return !memcmp(one->data, two->data, one->size);
4552}
4553
4554static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4555{
4556        int i;
4557        struct diff_queue_struct *q = &diff_queued_diff;
4558        struct diff_queue_struct outq;
4559        DIFF_QUEUE_CLEAR(&outq);
4560
4561        for (i = 0; i < q->nr; i++) {
4562                struct diff_filepair *p = q->queue[i];
4563
4564                /*
4565                 * 1. Entries that come from stat info dirtiness
4566                 *    always have both sides (iow, not create/delete),
4567                 *    one side of the object name is unknown, with
4568                 *    the same mode and size.  Keep the ones that
4569                 *    do not match these criteria.  They have real
4570                 *    differences.
4571                 *
4572                 * 2. At this point, the file is known to be modified,
4573                 *    with the same mode and size, and the object
4574                 *    name of one side is unknown.  Need to inspect
4575                 *    the identical contents.
4576                 */
4577                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4578                    !DIFF_FILE_VALID(p->two) ||
4579                    (p->one->sha1_valid && p->two->sha1_valid) ||
4580                    (p->one->mode != p->two->mode) ||
4581                    diff_populate_filespec(p->one, 1) ||
4582                    diff_populate_filespec(p->two, 1) ||
4583                    (p->one->size != p->two->size) ||
4584                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4585                        diff_q(&outq, p);
4586                else {
4587                        /*
4588                         * The caller can subtract 1 from skip_stat_unmatch
4589                         * to determine how many paths were dirty only
4590                         * due to stat info mismatch.
4591                         */
4592                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4593                                diffopt->skip_stat_unmatch++;
4594                        diff_free_filepair(p);
4595                }
4596        }
4597        free(q->queue);
4598        *q = outq;
4599}
4600
4601static int diffnamecmp(const void *a_, const void *b_)
4602{
4603        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4604        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4605        const char *name_a, *name_b;
4606
4607        name_a = a->one ? a->one->path : a->two->path;
4608        name_b = b->one ? b->one->path : b->two->path;
4609        return strcmp(name_a, name_b);
4610}
4611
4612void diffcore_fix_diff_index(struct diff_options *options)
4613{
4614        struct diff_queue_struct *q = &diff_queued_diff;
4615        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4616}
4617
4618void diffcore_std(struct diff_options *options)
4619{
4620        if (options->skip_stat_unmatch)
4621                diffcore_skip_stat_unmatch(options);
4622        if (!options->found_follow) {
4623                /* See try_to_follow_renames() in tree-diff.c */
4624                if (options->break_opt != -1)
4625                        diffcore_break(options->break_opt);
4626                if (options->detect_rename)
4627                        diffcore_rename(options);
4628                if (options->break_opt != -1)
4629                        diffcore_merge_broken();
4630        }
4631        if (options->pickaxe)
4632                diffcore_pickaxe(options);
4633        if (options->orderfile)
4634                diffcore_order(options->orderfile);
4635        if (!options->found_follow)
4636                /* See try_to_follow_renames() in tree-diff.c */
4637                diff_resolve_rename_copy();
4638        diffcore_apply_filter(options->filter);
4639
4640        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4641                DIFF_OPT_SET(options, HAS_CHANGES);
4642        else
4643                DIFF_OPT_CLR(options, HAS_CHANGES);
4644
4645        options->found_follow = 0;
4646}
4647
4648int diff_result_code(struct diff_options *opt, int status)
4649{
4650        int result = 0;
4651
4652        diff_warn_rename_limit("diff.renamelimit",
4653                               opt->needed_rename_limit,
4654                               opt->degraded_cc_to_c);
4655        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4656            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4657                return status;
4658        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4659            DIFF_OPT_TST(opt, HAS_CHANGES))
4660                result |= 01;
4661        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4662            DIFF_OPT_TST(opt, CHECK_FAILED))
4663                result |= 02;
4664        return result;
4665}
4666
4667int diff_can_quit_early(struct diff_options *opt)
4668{
4669        return (DIFF_OPT_TST(opt, QUICK) &&
4670                !opt->filter &&
4671                DIFF_OPT_TST(opt, HAS_CHANGES));
4672}
4673
4674/*
4675 * Shall changes to this submodule be ignored?
4676 *
4677 * Submodule changes can be configured to be ignored separately for each path,
4678 * but that configuration can be overridden from the command line.
4679 */
4680static int is_submodule_ignored(const char *path, struct diff_options *options)
4681{
4682        int ignored = 0;
4683        unsigned orig_flags = options->flags;
4684        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4685                set_diffopt_flags_from_submodule_config(options, path);
4686        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4687                ignored = 1;
4688        options->flags = orig_flags;
4689        return ignored;
4690}
4691
4692void diff_addremove(struct diff_options *options,
4693                    int addremove, unsigned mode,
4694                    const unsigned char *sha1,
4695                    int sha1_valid,
4696                    const char *concatpath, unsigned dirty_submodule)
4697{
4698        struct diff_filespec *one, *two;
4699
4700        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4701                return;
4702
4703        /* This may look odd, but it is a preparation for
4704         * feeding "there are unchanged files which should
4705         * not produce diffs, but when you are doing copy
4706         * detection you would need them, so here they are"
4707         * entries to the diff-core.  They will be prefixed
4708         * with something like '=' or '*' (I haven't decided
4709         * which but should not make any difference).
4710         * Feeding the same new and old to diff_change()
4711         * also has the same effect.
4712         * Before the final output happens, they are pruned after
4713         * merged into rename/copy pairs as appropriate.
4714         */
4715        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4716                addremove = (addremove == '+' ? '-' :
4717                             addremove == '-' ? '+' : addremove);
4718
4719        if (options->prefix &&
4720            strncmp(concatpath, options->prefix, options->prefix_length))
4721                return;
4722
4723        one = alloc_filespec(concatpath);
4724        two = alloc_filespec(concatpath);
4725
4726        if (addremove != '+')
4727                fill_filespec(one, sha1, sha1_valid, mode);
4728        if (addremove != '-') {
4729                fill_filespec(two, sha1, sha1_valid, mode);
4730                two->dirty_submodule = dirty_submodule;
4731        }
4732
4733        diff_queue(&diff_queued_diff, one, two);
4734        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4735                DIFF_OPT_SET(options, HAS_CHANGES);
4736}
4737
4738void diff_change(struct diff_options *options,
4739                 unsigned old_mode, unsigned new_mode,
4740                 const unsigned char *old_sha1,
4741                 const unsigned char *new_sha1,
4742                 int old_sha1_valid, int new_sha1_valid,
4743                 const char *concatpath,
4744                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4745{
4746        struct diff_filespec *one, *two;
4747
4748        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4749            is_submodule_ignored(concatpath, options))
4750                return;
4751
4752        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4753                unsigned tmp;
4754                const unsigned char *tmp_c;
4755                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4756                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4757                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4758                        new_sha1_valid = tmp;
4759                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4760                        new_dirty_submodule = tmp;
4761        }
4762
4763        if (options->prefix &&
4764            strncmp(concatpath, options->prefix, options->prefix_length))
4765                return;
4766
4767        one = alloc_filespec(concatpath);
4768        two = alloc_filespec(concatpath);
4769        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4770        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4771        one->dirty_submodule = old_dirty_submodule;
4772        two->dirty_submodule = new_dirty_submodule;
4773
4774        diff_queue(&diff_queued_diff, one, two);
4775        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4776                DIFF_OPT_SET(options, HAS_CHANGES);
4777}
4778
4779struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4780{
4781        struct diff_filepair *pair;
4782        struct diff_filespec *one, *two;
4783
4784        if (options->prefix &&
4785            strncmp(path, options->prefix, options->prefix_length))
4786                return NULL;
4787
4788        one = alloc_filespec(path);
4789        two = alloc_filespec(path);
4790        pair = diff_queue(&diff_queued_diff, one, two);
4791        pair->is_unmerged = 1;
4792        return pair;
4793}
4794
4795static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4796                size_t *outsize)
4797{
4798        struct diff_tempfile *temp;
4799        const char *argv[3];
4800        const char **arg = argv;
4801        struct child_process child;
4802        struct strbuf buf = STRBUF_INIT;
4803        int err = 0;
4804
4805        temp = prepare_temp_file(spec->path, spec);
4806        *arg++ = pgm;
4807        *arg++ = temp->name;
4808        *arg = NULL;
4809
4810        memset(&child, 0, sizeof(child));
4811        child.use_shell = 1;
4812        child.argv = argv;
4813        child.out = -1;
4814        if (start_command(&child)) {
4815                remove_tempfile();
4816                return NULL;
4817        }
4818
4819        if (strbuf_read(&buf, child.out, 0) < 0)
4820                err = error("error reading from textconv command '%s'", pgm);
4821        close(child.out);
4822
4823        if (finish_command(&child) || err) {
4824                strbuf_release(&buf);
4825                remove_tempfile();
4826                return NULL;
4827        }
4828        remove_tempfile();
4829
4830        return strbuf_detach(&buf, outsize);
4831}
4832
4833size_t fill_textconv(struct userdiff_driver *driver,
4834                     struct diff_filespec *df,
4835                     char **outbuf)
4836{
4837        size_t size;
4838
4839        if (!driver || !driver->textconv) {
4840                if (!DIFF_FILE_VALID(df)) {
4841                        *outbuf = "";
4842                        return 0;
4843                }
4844                if (diff_populate_filespec(df, 0))
4845                        die("unable to read files to diff");
4846                *outbuf = df->data;
4847                return df->size;
4848        }
4849
4850        if (driver->textconv_cache && df->sha1_valid) {
4851                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4852                                          &size);
4853                if (*outbuf)
4854                        return size;
4855        }
4856
4857        *outbuf = run_textconv(driver->textconv, df, &size);
4858        if (!*outbuf)
4859                die("unable to read files to diff");
4860
4861        if (driver->textconv_cache && df->sha1_valid) {
4862                /* ignore errors, as we might be in a readonly repository */
4863                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4864                                size);
4865                /*
4866                 * we could save up changes and flush them all at the end,
4867                 * but we would need an extra call after all diffing is done.
4868                 * Since generating a cache entry is the slow path anyway,
4869                 * this extra overhead probably isn't a big deal.
4870                 */
4871                notes_cache_write(driver->textconv_cache);
4872        }
4873
4874        return size;
4875}