diff.con commit diff --stat: report mode-only changes for binary files like text files (e18872b)
   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                emit_line_0(ecb->opt, plain, reset, '\\',
 578                            nneof, strlen(nneof));
 579        }
 580}
 581
 582static void emit_rewrite_diff(const char *name_a,
 583                              const char *name_b,
 584                              struct diff_filespec *one,
 585                              struct diff_filespec *two,
 586                              struct userdiff_driver *textconv_one,
 587                              struct userdiff_driver *textconv_two,
 588                              struct diff_options *o)
 589{
 590        int lc_a, lc_b;
 591        const char *name_a_tab, *name_b_tab;
 592        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 593        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 594        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 595        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 596        const char *a_prefix, *b_prefix;
 597        char *data_one, *data_two;
 598        size_t size_one, size_two;
 599        struct emit_callback ecbdata;
 600        char *line_prefix = "";
 601        struct strbuf *msgbuf;
 602
 603        if (o && o->output_prefix) {
 604                msgbuf = o->output_prefix(o, o->output_prefix_data);
 605                line_prefix = msgbuf->buf;
 606        }
 607
 608        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 609                a_prefix = o->b_prefix;
 610                b_prefix = o->a_prefix;
 611        } else {
 612                a_prefix = o->a_prefix;
 613                b_prefix = o->b_prefix;
 614        }
 615
 616        name_a += (*name_a == '/');
 617        name_b += (*name_b == '/');
 618        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 619        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 620
 621        strbuf_reset(&a_name);
 622        strbuf_reset(&b_name);
 623        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 624        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 625
 626        size_one = fill_textconv(textconv_one, one, &data_one);
 627        size_two = fill_textconv(textconv_two, two, &data_two);
 628
 629        memset(&ecbdata, 0, sizeof(ecbdata));
 630        ecbdata.color_diff = want_color(o->use_color);
 631        ecbdata.found_changesp = &o->found_changes;
 632        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 633        ecbdata.opt = o;
 634        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 635                mmfile_t mf1, mf2;
 636                mf1.ptr = (char *)data_one;
 637                mf2.ptr = (char *)data_two;
 638                mf1.size = size_one;
 639                mf2.size = size_two;
 640                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 641        }
 642        ecbdata.lno_in_preimage = 1;
 643        ecbdata.lno_in_postimage = 1;
 644
 645        lc_a = count_lines(data_one, size_one);
 646        lc_b = count_lines(data_two, size_two);
 647        fprintf(o->file,
 648                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 649                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 650                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 651                line_prefix, fraginfo);
 652        if (!o->irreversible_delete)
 653                print_line_count(o->file, lc_a);
 654        else
 655                fprintf(o->file, "?,?");
 656        fprintf(o->file, " +");
 657        print_line_count(o->file, lc_b);
 658        fprintf(o->file, " @@%s\n", reset);
 659        if (lc_a && !o->irreversible_delete)
 660                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 661        if (lc_b)
 662                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 663        if (textconv_one)
 664                free((char *)data_one);
 665        if (textconv_two)
 666                free((char *)data_two);
 667}
 668
 669struct diff_words_buffer {
 670        mmfile_t text;
 671        long alloc;
 672        struct diff_words_orig {
 673                const char *begin, *end;
 674        } *orig;
 675        int orig_nr, orig_alloc;
 676};
 677
 678static void diff_words_append(char *line, unsigned long len,
 679                struct diff_words_buffer *buffer)
 680{
 681        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 682        line++;
 683        len--;
 684        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 685        buffer->text.size += len;
 686        buffer->text.ptr[buffer->text.size] = '\0';
 687}
 688
 689struct diff_words_style_elem {
 690        const char *prefix;
 691        const char *suffix;
 692        const char *color; /* NULL; filled in by the setup code if
 693                            * color is enabled */
 694};
 695
 696struct diff_words_style {
 697        enum diff_words_type type;
 698        struct diff_words_style_elem new, old, ctx;
 699        const char *newline;
 700};
 701
 702static struct diff_words_style diff_words_styles[] = {
 703        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 704        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 705        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 706};
 707
 708struct diff_words_data {
 709        struct diff_words_buffer minus, plus;
 710        const char *current_plus;
 711        int last_minus;
 712        struct diff_options *opt;
 713        regex_t *word_regex;
 714        enum diff_words_type type;
 715        struct diff_words_style *style;
 716};
 717
 718static int fn_out_diff_words_write_helper(FILE *fp,
 719                                          struct diff_words_style_elem *st_el,
 720                                          const char *newline,
 721                                          size_t count, const char *buf,
 722                                          const char *line_prefix)
 723{
 724        int print = 0;
 725
 726        while (count) {
 727                char *p = memchr(buf, '\n', count);
 728                if (print)
 729                        fputs(line_prefix, fp);
 730                if (p != buf) {
 731                        if (st_el->color && fputs(st_el->color, fp) < 0)
 732                                return -1;
 733                        if (fputs(st_el->prefix, fp) < 0 ||
 734                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 735                            fputs(st_el->suffix, fp) < 0)
 736                                return -1;
 737                        if (st_el->color && *st_el->color
 738                            && fputs(GIT_COLOR_RESET, fp) < 0)
 739                                return -1;
 740                }
 741                if (!p)
 742                        return 0;
 743                if (fputs(newline, fp) < 0)
 744                        return -1;
 745                count -= p + 1 - buf;
 746                buf = p + 1;
 747                print = 1;
 748        }
 749        return 0;
 750}
 751
 752/*
 753 * '--color-words' algorithm can be described as:
 754 *
 755 *   1. collect a the minus/plus lines of a diff hunk, divided into
 756 *      minus-lines and plus-lines;
 757 *
 758 *   2. break both minus-lines and plus-lines into words and
 759 *      place them into two mmfile_t with one word for each line;
 760 *
 761 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 762 *
 763 * And for the common parts of the both file, we output the plus side text.
 764 * diff_words->current_plus is used to trace the current position of the plus file
 765 * which printed. diff_words->last_minus is used to trace the last minus word
 766 * printed.
 767 *
 768 * For '--graph' to work with '--color-words', we need to output the graph prefix
 769 * on each line of color words output. Generally, there are two conditions on
 770 * which we should output the prefix.
 771 *
 772 *   1. diff_words->last_minus == 0 &&
 773 *      diff_words->current_plus == diff_words->plus.text.ptr
 774 *
 775 *      that is: the plus text must start as a new line, and if there is no minus
 776 *      word printed, a graph prefix must be printed.
 777 *
 778 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 779 *      *(diff_words->current_plus - 1) == '\n'
 780 *
 781 *      that is: a graph prefix must be printed following a '\n'
 782 */
 783static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 784{
 785        if ((diff_words->last_minus == 0 &&
 786                diff_words->current_plus == diff_words->plus.text.ptr) ||
 787                (diff_words->current_plus > diff_words->plus.text.ptr &&
 788                *(diff_words->current_plus - 1) == '\n')) {
 789                return 1;
 790        } else {
 791                return 0;
 792        }
 793}
 794
 795static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 796{
 797        struct diff_words_data *diff_words = priv;
 798        struct diff_words_style *style = diff_words->style;
 799        int minus_first, minus_len, plus_first, plus_len;
 800        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 801        struct diff_options *opt = diff_words->opt;
 802        struct strbuf *msgbuf;
 803        char *line_prefix = "";
 804
 805        if (line[0] != '@' || parse_hunk_header(line, len,
 806                        &minus_first, &minus_len, &plus_first, &plus_len))
 807                return;
 808
 809        assert(opt);
 810        if (opt->output_prefix) {
 811                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 812                line_prefix = msgbuf->buf;
 813        }
 814
 815        /* POSIX requires that first be decremented by one if len == 0... */
 816        if (minus_len) {
 817                minus_begin = diff_words->minus.orig[minus_first].begin;
 818                minus_end =
 819                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 820        } else
 821                minus_begin = minus_end =
 822                        diff_words->minus.orig[minus_first].end;
 823
 824        if (plus_len) {
 825                plus_begin = diff_words->plus.orig[plus_first].begin;
 826                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 827        } else
 828                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 829
 830        if (color_words_output_graph_prefix(diff_words)) {
 831                fputs(line_prefix, diff_words->opt->file);
 832        }
 833        if (diff_words->current_plus != plus_begin) {
 834                fn_out_diff_words_write_helper(diff_words->opt->file,
 835                                &style->ctx, style->newline,
 836                                plus_begin - diff_words->current_plus,
 837                                diff_words->current_plus, line_prefix);
 838                if (*(plus_begin - 1) == '\n')
 839                        fputs(line_prefix, diff_words->opt->file);
 840        }
 841        if (minus_begin != minus_end) {
 842                fn_out_diff_words_write_helper(diff_words->opt->file,
 843                                &style->old, style->newline,
 844                                minus_end - minus_begin, minus_begin,
 845                                line_prefix);
 846        }
 847        if (plus_begin != plus_end) {
 848                fn_out_diff_words_write_helper(diff_words->opt->file,
 849                                &style->new, style->newline,
 850                                plus_end - plus_begin, plus_begin,
 851                                line_prefix);
 852        }
 853
 854        diff_words->current_plus = plus_end;
 855        diff_words->last_minus = minus_first;
 856}
 857
 858/* This function starts looking at *begin, and returns 0 iff a word was found. */
 859static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 860                int *begin, int *end)
 861{
 862        if (word_regex && *begin < buffer->size) {
 863                regmatch_t match[1];
 864                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 865                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 866                                        '\n', match[0].rm_eo - match[0].rm_so);
 867                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 868                        *begin += match[0].rm_so;
 869                        return *begin >= *end;
 870                }
 871                return -1;
 872        }
 873
 874        /* find the next word */
 875        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 876                (*begin)++;
 877        if (*begin >= buffer->size)
 878                return -1;
 879
 880        /* find the end of the word */
 881        *end = *begin + 1;
 882        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 883                (*end)++;
 884
 885        return 0;
 886}
 887
 888/*
 889 * This function splits the words in buffer->text, stores the list with
 890 * newline separator into out, and saves the offsets of the original words
 891 * in buffer->orig.
 892 */
 893static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 894                regex_t *word_regex)
 895{
 896        int i, j;
 897        long alloc = 0;
 898
 899        out->size = 0;
 900        out->ptr = NULL;
 901
 902        /* fake an empty "0th" word */
 903        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 904        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 905        buffer->orig_nr = 1;
 906
 907        for (i = 0; i < buffer->text.size; i++) {
 908                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 909                        return;
 910
 911                /* store original boundaries */
 912                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 913                                buffer->orig_alloc);
 914                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 915                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 916                buffer->orig_nr++;
 917
 918                /* store one word */
 919                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 920                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 921                out->ptr[out->size + j - i] = '\n';
 922                out->size += j - i + 1;
 923
 924                i = j - 1;
 925        }
 926}
 927
 928/* this executes the word diff on the accumulated buffers */
 929static void diff_words_show(struct diff_words_data *diff_words)
 930{
 931        xpparam_t xpp;
 932        xdemitconf_t xecfg;
 933        mmfile_t minus, plus;
 934        struct diff_words_style *style = diff_words->style;
 935
 936        struct diff_options *opt = diff_words->opt;
 937        struct strbuf *msgbuf;
 938        char *line_prefix = "";
 939
 940        assert(opt);
 941        if (opt->output_prefix) {
 942                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 943                line_prefix = msgbuf->buf;
 944        }
 945
 946        /* special case: only removal */
 947        if (!diff_words->plus.text.size) {
 948                fputs(line_prefix, diff_words->opt->file);
 949                fn_out_diff_words_write_helper(diff_words->opt->file,
 950                        &style->old, style->newline,
 951                        diff_words->minus.text.size,
 952                        diff_words->minus.text.ptr, line_prefix);
 953                diff_words->minus.text.size = 0;
 954                return;
 955        }
 956
 957        diff_words->current_plus = diff_words->plus.text.ptr;
 958        diff_words->last_minus = 0;
 959
 960        memset(&xpp, 0, sizeof(xpp));
 961        memset(&xecfg, 0, sizeof(xecfg));
 962        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 963        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 964        xpp.flags = 0;
 965        /* as only the hunk header will be parsed, we need a 0-context */
 966        xecfg.ctxlen = 0;
 967        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 968                      &xpp, &xecfg);
 969        free(minus.ptr);
 970        free(plus.ptr);
 971        if (diff_words->current_plus != diff_words->plus.text.ptr +
 972                        diff_words->plus.text.size) {
 973                if (color_words_output_graph_prefix(diff_words))
 974                        fputs(line_prefix, diff_words->opt->file);
 975                fn_out_diff_words_write_helper(diff_words->opt->file,
 976                        &style->ctx, style->newline,
 977                        diff_words->plus.text.ptr + diff_words->plus.text.size
 978                        - diff_words->current_plus, diff_words->current_plus,
 979                        line_prefix);
 980        }
 981        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 982}
 983
 984/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 985static void diff_words_flush(struct emit_callback *ecbdata)
 986{
 987        if (ecbdata->diff_words->minus.text.size ||
 988            ecbdata->diff_words->plus.text.size)
 989                diff_words_show(ecbdata->diff_words);
 990}
 991
 992static void diff_filespec_load_driver(struct diff_filespec *one)
 993{
 994        /* Use already-loaded driver */
 995        if (one->driver)
 996                return;
 997
 998        if (S_ISREG(one->mode))
 999                one->driver = userdiff_find_by_path(one->path);
1000
1001        /* Fallback to default settings */
1002        if (!one->driver)
1003                one->driver = userdiff_find_by_name("default");
1004}
1005
1006static const char *userdiff_word_regex(struct diff_filespec *one)
1007{
1008        diff_filespec_load_driver(one);
1009        return one->driver->word_regex;
1010}
1011
1012static void init_diff_words_data(struct emit_callback *ecbdata,
1013                                 struct diff_options *orig_opts,
1014                                 struct diff_filespec *one,
1015                                 struct diff_filespec *two)
1016{
1017        int i;
1018        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1019        memcpy(o, orig_opts, sizeof(struct diff_options));
1020
1021        ecbdata->diff_words =
1022                xcalloc(1, sizeof(struct diff_words_data));
1023        ecbdata->diff_words->type = o->word_diff;
1024        ecbdata->diff_words->opt = o;
1025        if (!o->word_regex)
1026                o->word_regex = userdiff_word_regex(one);
1027        if (!o->word_regex)
1028                o->word_regex = userdiff_word_regex(two);
1029        if (!o->word_regex)
1030                o->word_regex = diff_word_regex_cfg;
1031        if (o->word_regex) {
1032                ecbdata->diff_words->word_regex = (regex_t *)
1033                        xmalloc(sizeof(regex_t));
1034                if (regcomp(ecbdata->diff_words->word_regex,
1035                            o->word_regex,
1036                            REG_EXTENDED | REG_NEWLINE))
1037                        die ("Invalid regular expression: %s",
1038                             o->word_regex);
1039        }
1040        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1041                if (o->word_diff == diff_words_styles[i].type) {
1042                        ecbdata->diff_words->style =
1043                                &diff_words_styles[i];
1044                        break;
1045                }
1046        }
1047        if (want_color(o->use_color)) {
1048                struct diff_words_style *st = ecbdata->diff_words->style;
1049                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1050                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1051                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1052        }
1053}
1054
1055static void free_diff_words_data(struct emit_callback *ecbdata)
1056{
1057        if (ecbdata->diff_words) {
1058                diff_words_flush(ecbdata);
1059                free (ecbdata->diff_words->opt);
1060                free (ecbdata->diff_words->minus.text.ptr);
1061                free (ecbdata->diff_words->minus.orig);
1062                free (ecbdata->diff_words->plus.text.ptr);
1063                free (ecbdata->diff_words->plus.orig);
1064                if (ecbdata->diff_words->word_regex) {
1065                        regfree(ecbdata->diff_words->word_regex);
1066                        free(ecbdata->diff_words->word_regex);
1067                }
1068                free(ecbdata->diff_words);
1069                ecbdata->diff_words = NULL;
1070        }
1071}
1072
1073const char *diff_get_color(int diff_use_color, enum color_diff ix)
1074{
1075        if (want_color(diff_use_color))
1076                return diff_colors[ix];
1077        return "";
1078}
1079
1080static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1081{
1082        const char *cp;
1083        unsigned long allot;
1084        size_t l = len;
1085
1086        if (ecb->truncate)
1087                return ecb->truncate(line, len);
1088        cp = line;
1089        allot = l;
1090        while (0 < l) {
1091                (void) utf8_width(&cp, &l);
1092                if (!cp)
1093                        break; /* truncated in the middle? */
1094        }
1095        return allot - l;
1096}
1097
1098static void find_lno(const char *line, struct emit_callback *ecbdata)
1099{
1100        const char *p;
1101        ecbdata->lno_in_preimage = 0;
1102        ecbdata->lno_in_postimage = 0;
1103        p = strchr(line, '-');
1104        if (!p)
1105                return; /* cannot happen */
1106        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1107        p = strchr(p, '+');
1108        if (!p)
1109                return; /* cannot happen */
1110        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1111}
1112
1113static void fn_out_consume(void *priv, char *line, unsigned long len)
1114{
1115        struct emit_callback *ecbdata = priv;
1116        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1117        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1118        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1119        struct diff_options *o = ecbdata->opt;
1120        char *line_prefix = "";
1121        struct strbuf *msgbuf;
1122
1123        if (o && o->output_prefix) {
1124                msgbuf = o->output_prefix(o, o->output_prefix_data);
1125                line_prefix = msgbuf->buf;
1126        }
1127
1128        if (ecbdata->header) {
1129                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1130                strbuf_reset(ecbdata->header);
1131                ecbdata->header = NULL;
1132        }
1133        *(ecbdata->found_changesp) = 1;
1134
1135        if (ecbdata->label_path[0]) {
1136                const char *name_a_tab, *name_b_tab;
1137
1138                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1139                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1140
1141                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1142                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1143                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1144                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1145                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1146        }
1147
1148        if (diff_suppress_blank_empty
1149            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1150                line[0] = '\n';
1151                len = 1;
1152        }
1153
1154        if (line[0] == '@') {
1155                if (ecbdata->diff_words)
1156                        diff_words_flush(ecbdata);
1157                len = sane_truncate_line(ecbdata, line, len);
1158                find_lno(line, ecbdata);
1159                emit_hunk_header(ecbdata, line, len);
1160                if (line[len-1] != '\n')
1161                        putc('\n', ecbdata->opt->file);
1162                return;
1163        }
1164
1165        if (len < 1) {
1166                emit_line(ecbdata->opt, reset, reset, line, len);
1167                if (ecbdata->diff_words
1168                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1169                        fputs("~\n", ecbdata->opt->file);
1170                return;
1171        }
1172
1173        if (ecbdata->diff_words) {
1174                if (line[0] == '-') {
1175                        diff_words_append(line, len,
1176                                          &ecbdata->diff_words->minus);
1177                        return;
1178                } else if (line[0] == '+') {
1179                        diff_words_append(line, len,
1180                                          &ecbdata->diff_words->plus);
1181                        return;
1182                } else if (!prefixcmp(line, "\\ ")) {
1183                        /*
1184                         * Eat the "no newline at eof" marker as if we
1185                         * saw a "+" or "-" line with nothing on it,
1186                         * and return without diff_words_flush() to
1187                         * defer processing. If this is the end of
1188                         * preimage, more "+" lines may come after it.
1189                         */
1190                        return;
1191                }
1192                diff_words_flush(ecbdata);
1193                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1194                        emit_line(ecbdata->opt, plain, reset, line, len);
1195                        fputs("~\n", ecbdata->opt->file);
1196                } else {
1197                        /*
1198                         * Skip the prefix character, if any.  With
1199                         * diff_suppress_blank_empty, there may be
1200                         * none.
1201                         */
1202                        if (line[0] != '\n') {
1203                              line++;
1204                              len--;
1205                        }
1206                        emit_line(ecbdata->opt, plain, reset, line, len);
1207                }
1208                return;
1209        }
1210
1211        if (line[0] != '+') {
1212                const char *color =
1213                        diff_get_color(ecbdata->color_diff,
1214                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1215                ecbdata->lno_in_preimage++;
1216                if (line[0] == ' ')
1217                        ecbdata->lno_in_postimage++;
1218                emit_line(ecbdata->opt, color, reset, line, len);
1219        } else {
1220                ecbdata->lno_in_postimage++;
1221                emit_add_line(reset, ecbdata, line + 1, len - 1);
1222        }
1223}
1224
1225static char *pprint_rename(const char *a, const char *b)
1226{
1227        const char *old = a;
1228        const char *new = b;
1229        struct strbuf name = STRBUF_INIT;
1230        int pfx_length, sfx_length;
1231        int len_a = strlen(a);
1232        int len_b = strlen(b);
1233        int a_midlen, b_midlen;
1234        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1235        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1236
1237        if (qlen_a || qlen_b) {
1238                quote_c_style(a, &name, NULL, 0);
1239                strbuf_addstr(&name, " => ");
1240                quote_c_style(b, &name, NULL, 0);
1241                return strbuf_detach(&name, NULL);
1242        }
1243
1244        /* Find common prefix */
1245        pfx_length = 0;
1246        while (*old && *new && *old == *new) {
1247                if (*old == '/')
1248                        pfx_length = old - a + 1;
1249                old++;
1250                new++;
1251        }
1252
1253        /* Find common suffix */
1254        old = a + len_a;
1255        new = b + len_b;
1256        sfx_length = 0;
1257        while (a <= old && b <= new && *old == *new) {
1258                if (*old == '/')
1259                        sfx_length = len_a - (old - a);
1260                old--;
1261                new--;
1262        }
1263
1264        /*
1265         * pfx{mid-a => mid-b}sfx
1266         * {pfx-a => pfx-b}sfx
1267         * pfx{sfx-a => sfx-b}
1268         * name-a => name-b
1269         */
1270        a_midlen = len_a - pfx_length - sfx_length;
1271        b_midlen = len_b - pfx_length - sfx_length;
1272        if (a_midlen < 0)
1273                a_midlen = 0;
1274        if (b_midlen < 0)
1275                b_midlen = 0;
1276
1277        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1278        if (pfx_length + sfx_length) {
1279                strbuf_add(&name, a, pfx_length);
1280                strbuf_addch(&name, '{');
1281        }
1282        strbuf_add(&name, a + pfx_length, a_midlen);
1283        strbuf_addstr(&name, " => ");
1284        strbuf_add(&name, b + pfx_length, b_midlen);
1285        if (pfx_length + sfx_length) {
1286                strbuf_addch(&name, '}');
1287                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1288        }
1289        return strbuf_detach(&name, NULL);
1290}
1291
1292struct diffstat_t {
1293        int nr;
1294        int alloc;
1295        struct diffstat_file {
1296                char *from_name;
1297                char *name;
1298                char *print_name;
1299                unsigned is_unmerged:1;
1300                unsigned is_binary:1;
1301                unsigned is_renamed:1;
1302                uintmax_t added, deleted;
1303        } **files;
1304};
1305
1306static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1307                                          const char *name_a,
1308                                          const char *name_b)
1309{
1310        struct diffstat_file *x;
1311        x = xcalloc(sizeof (*x), 1);
1312        if (diffstat->nr == diffstat->alloc) {
1313                diffstat->alloc = alloc_nr(diffstat->alloc);
1314                diffstat->files = xrealloc(diffstat->files,
1315                                diffstat->alloc * sizeof(x));
1316        }
1317        diffstat->files[diffstat->nr++] = x;
1318        if (name_b) {
1319                x->from_name = xstrdup(name_a);
1320                x->name = xstrdup(name_b);
1321                x->is_renamed = 1;
1322        }
1323        else {
1324                x->from_name = NULL;
1325                x->name = xstrdup(name_a);
1326        }
1327        return x;
1328}
1329
1330static void diffstat_consume(void *priv, char *line, unsigned long len)
1331{
1332        struct diffstat_t *diffstat = priv;
1333        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1334
1335        if (line[0] == '+')
1336                x->added++;
1337        else if (line[0] == '-')
1338                x->deleted++;
1339}
1340
1341const char mime_boundary_leader[] = "------------";
1342
1343static int scale_linear(int it, int width, int max_change)
1344{
1345        if (!it)
1346                return 0;
1347        /*
1348         * make sure that at least one '-' or '+' is printed if
1349         * there is any change to this path. The easiest way is to
1350         * scale linearly as if the alloted width is one column shorter
1351         * than it is, and then add 1 to the result.
1352         */
1353        return 1 + (it * (width - 1) / max_change);
1354}
1355
1356static void show_name(FILE *file,
1357                      const char *prefix, const char *name, int len)
1358{
1359        fprintf(file, " %s%-*s |", prefix, len, name);
1360}
1361
1362static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1363{
1364        if (cnt <= 0)
1365                return;
1366        fprintf(file, "%s", set);
1367        while (cnt--)
1368                putc(ch, file);
1369        fprintf(file, "%s", reset);
1370}
1371
1372static void fill_print_name(struct diffstat_file *file)
1373{
1374        char *pname;
1375
1376        if (file->print_name)
1377                return;
1378
1379        if (!file->is_renamed) {
1380                struct strbuf buf = STRBUF_INIT;
1381                if (quote_c_style(file->name, &buf, NULL, 0)) {
1382                        pname = strbuf_detach(&buf, NULL);
1383                } else {
1384                        pname = file->name;
1385                        strbuf_release(&buf);
1386                }
1387        } else {
1388                pname = pprint_rename(file->from_name, file->name);
1389        }
1390        file->print_name = pname;
1391}
1392
1393int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1394{
1395        struct strbuf sb = STRBUF_INIT;
1396        int ret;
1397
1398        if (!files) {
1399                assert(insertions == 0 && deletions == 0);
1400                return fputs(_(" 0 files changed\n"), fp);
1401        }
1402
1403        strbuf_addf(&sb,
1404                    Q_(" %d file changed", " %d files changed", files),
1405                    files);
1406
1407        /*
1408         * For binary diff, the caller may want to print "x files
1409         * changed" with insertions == 0 && deletions == 0.
1410         *
1411         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1412         * is probably less confusing (i.e skip over "2 files changed
1413         * but nothing about added/removed lines? Is this a bug in Git?").
1414         */
1415        if (insertions || deletions == 0) {
1416                /*
1417                 * TRANSLATORS: "+" in (+) is a line addition marker;
1418                 * do not translate it.
1419                 */
1420                strbuf_addf(&sb,
1421                            Q_(", %d insertion(+)", ", %d insertions(+)",
1422                               insertions),
1423                            insertions);
1424        }
1425
1426        if (deletions || insertions == 0) {
1427                /*
1428                 * TRANSLATORS: "-" in (-) is a line removal marker;
1429                 * do not translate it.
1430                 */
1431                strbuf_addf(&sb,
1432                            Q_(", %d deletion(-)", ", %d deletions(-)",
1433                               deletions),
1434                            deletions);
1435        }
1436        strbuf_addch(&sb, '\n');
1437        ret = fputs(sb.buf, fp);
1438        strbuf_release(&sb);
1439        return ret;
1440}
1441
1442static void show_stats(struct diffstat_t *data, struct diff_options *options)
1443{
1444        int i, len, add, del, adds = 0, dels = 0;
1445        uintmax_t max_change = 0, max_len = 0;
1446        int total_files = data->nr;
1447        int width, name_width, graph_width, number_width = 4, count;
1448        const char *reset, *add_c, *del_c;
1449        const char *line_prefix = "";
1450        int extra_shown = 0;
1451        struct strbuf *msg = NULL;
1452
1453        if (data->nr == 0)
1454                return;
1455
1456        if (options->output_prefix) {
1457                msg = options->output_prefix(options, options->output_prefix_data);
1458                line_prefix = msg->buf;
1459        }
1460
1461        count = options->stat_count ? options->stat_count : data->nr;
1462
1463        reset = diff_get_color_opt(options, DIFF_RESET);
1464        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1465        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1466
1467        /*
1468         * Find the longest filename and max number of changes
1469         */
1470        for (i = 0; (i < count) && (i < data->nr); i++) {
1471                struct diffstat_file *file = data->files[i];
1472                uintmax_t change = file->added + file->deleted;
1473                if (!data->files[i]->is_renamed &&
1474                         (change == 0)) {
1475                        count++; /* not shown == room for one more */
1476                        continue;
1477                }
1478                fill_print_name(file);
1479                len = strlen(file->print_name);
1480                if (max_len < len)
1481                        max_len = len;
1482
1483                if (file->is_binary || file->is_unmerged)
1484                        continue;
1485                if (max_change < change)
1486                        max_change = change;
1487        }
1488        count = i; /* min(count, data->nr) */
1489
1490        /*
1491         * We have width = stat_width or term_columns() columns total.
1492         * We want a maximum of min(max_len, stat_name_width) for the name part.
1493         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1494         * We also need 1 for " " and 4 + decimal_width(max_change)
1495         * for " | NNNN " and one the empty column at the end, altogether
1496         * 6 + decimal_width(max_change).
1497         *
1498         * If there's not enough space, we will use the smaller of
1499         * stat_name_width (if set) and 5/8*width for the filename,
1500         * and the rest for constant elements + graph part, but no more
1501         * than stat_graph_width for the graph part.
1502         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1503         * for the standard terminal size).
1504         *
1505         * In other words: stat_width limits the maximum width, and
1506         * stat_name_width fixes the maximum width of the filename,
1507         * and is also used to divide available columns if there
1508         * aren't enough.
1509         */
1510
1511        if (options->stat_width == -1)
1512                width = term_columns();
1513        else
1514                width = options->stat_width ? options->stat_width : 80;
1515
1516        if (options->stat_graph_width == -1)
1517                options->stat_graph_width = diff_stat_graph_width;
1518
1519        /*
1520         * Guarantee 3/8*16==6 for the graph part
1521         * and 5/8*16==10 for the filename part
1522         */
1523        if (width < 16 + 6 + number_width)
1524                width = 16 + 6 + number_width;
1525
1526        /*
1527         * First assign sizes that are wanted, ignoring available width.
1528         */
1529        graph_width = (options->stat_graph_width &&
1530                       options->stat_graph_width < max_change) ?
1531                options->stat_graph_width : max_change;
1532        name_width = (options->stat_name_width > 0 &&
1533                      options->stat_name_width < max_len) ?
1534                options->stat_name_width : max_len;
1535
1536        /*
1537         * Adjust adjustable widths not to exceed maximum width
1538         */
1539        if (name_width + number_width + 6 + graph_width > width) {
1540                if (graph_width > width * 3/8 - number_width - 6)
1541                        graph_width = width * 3/8 - number_width - 6;
1542                if (options->stat_graph_width &&
1543                    graph_width > options->stat_graph_width)
1544                        graph_width = options->stat_graph_width;
1545                if (name_width > width - number_width - 6 - graph_width)
1546                        name_width = width - number_width - 6 - graph_width;
1547                else
1548                        graph_width = width - number_width - 6 - name_width;
1549        }
1550
1551        /*
1552         * From here name_width is the width of the name area,
1553         * and graph_width is the width of the graph area.
1554         * max_change is used to scale graph properly.
1555         */
1556        for (i = 0; i < count; i++) {
1557                const char *prefix = "";
1558                char *name = data->files[i]->print_name;
1559                uintmax_t added = data->files[i]->added;
1560                uintmax_t deleted = data->files[i]->deleted;
1561                int name_len;
1562
1563                if (!data->files[i]->is_renamed &&
1564                         (added + deleted == 0)) {
1565                        total_files--;
1566                        continue;
1567                }
1568                /*
1569                 * "scale" the filename
1570                 */
1571                len = name_width;
1572                name_len = strlen(name);
1573                if (name_width < name_len) {
1574                        char *slash;
1575                        prefix = "...";
1576                        len -= 3;
1577                        name += name_len - len;
1578                        slash = strchr(name, '/');
1579                        if (slash)
1580                                name = slash;
1581                }
1582
1583                if (data->files[i]->is_binary) {
1584                        fprintf(options->file, "%s", line_prefix);
1585                        show_name(options->file, prefix, name, len);
1586                        fprintf(options->file, "  Bin");
1587                        if (!added && !deleted) {
1588                                putc('\n', options->file);
1589                                continue;
1590                        }
1591                        fprintf(options->file, " %s%"PRIuMAX"%s",
1592                                del_c, deleted, reset);
1593                        fprintf(options->file, " -> ");
1594                        fprintf(options->file, "%s%"PRIuMAX"%s",
1595                                add_c, added, reset);
1596                        fprintf(options->file, " bytes");
1597                        fprintf(options->file, "\n");
1598                        continue;
1599                }
1600                else if (data->files[i]->is_unmerged) {
1601                        fprintf(options->file, "%s", line_prefix);
1602                        show_name(options->file, prefix, name, len);
1603                        fprintf(options->file, "  Unmerged\n");
1604                        continue;
1605                }
1606
1607                /*
1608                 * scale the add/delete
1609                 */
1610                add = added;
1611                del = deleted;
1612                adds += add;
1613                dels += del;
1614
1615                if (graph_width <= max_change) {
1616                        int total = add + del;
1617
1618                        total = scale_linear(add + del, graph_width, max_change);
1619                        if (total < 2 && add && del)
1620                                /* width >= 2 due to the sanity check */
1621                                total = 2;
1622                        if (add < del) {
1623                                add = scale_linear(add, graph_width, max_change);
1624                                del = total - add;
1625                        } else {
1626                                del = scale_linear(del, graph_width, max_change);
1627                                add = total - del;
1628                        }
1629                }
1630                fprintf(options->file, "%s", line_prefix);
1631                show_name(options->file, prefix, name, len);
1632                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1633                                added + deleted ? " " : "");
1634                show_graph(options->file, '+', add, add_c, reset);
1635                show_graph(options->file, '-', del, del_c, reset);
1636                fprintf(options->file, "\n");
1637        }
1638        for (i = count; i < data->nr; i++) {
1639                uintmax_t added = data->files[i]->added;
1640                uintmax_t deleted = data->files[i]->deleted;
1641                if (!data->files[i]->is_renamed &&
1642                         (added + deleted == 0)) {
1643                        total_files--;
1644                        continue;
1645                }
1646                adds += added;
1647                dels += deleted;
1648                if (!extra_shown)
1649                        fprintf(options->file, "%s ...\n", line_prefix);
1650                extra_shown = 1;
1651        }
1652        fprintf(options->file, "%s", line_prefix);
1653        print_stat_summary(options->file, total_files, adds, dels);
1654}
1655
1656static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1657{
1658        int i, adds = 0, dels = 0, total_files = data->nr;
1659
1660        if (data->nr == 0)
1661                return;
1662
1663        for (i = 0; i < data->nr; i++) {
1664                int added = data->files[i]->added;
1665                int deleted= data->files[i]->deleted;
1666
1667                if (data->files[i]->is_unmerged)
1668                        continue;
1669                if (!data->files[i]->is_renamed && (added + deleted == 0)) {
1670                        total_files--;
1671                } else {
1672                        adds += added;
1673                        dels += deleted;
1674                }
1675        }
1676        if (options->output_prefix) {
1677                struct strbuf *msg = NULL;
1678                msg = options->output_prefix(options,
1679                                options->output_prefix_data);
1680                fprintf(options->file, "%s", msg->buf);
1681        }
1682        print_stat_summary(options->file, total_files, adds, dels);
1683}
1684
1685static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1686{
1687        int i;
1688
1689        if (data->nr == 0)
1690                return;
1691
1692        for (i = 0; i < data->nr; i++) {
1693                struct diffstat_file *file = data->files[i];
1694
1695                if (options->output_prefix) {
1696                        struct strbuf *msg = NULL;
1697                        msg = options->output_prefix(options,
1698                                        options->output_prefix_data);
1699                        fprintf(options->file, "%s", msg->buf);
1700                }
1701
1702                if (file->is_binary)
1703                        fprintf(options->file, "-\t-\t");
1704                else
1705                        fprintf(options->file,
1706                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1707                                file->added, file->deleted);
1708                if (options->line_termination) {
1709                        fill_print_name(file);
1710                        if (!file->is_renamed)
1711                                write_name_quoted(file->name, options->file,
1712                                                  options->line_termination);
1713                        else {
1714                                fputs(file->print_name, options->file);
1715                                putc(options->line_termination, options->file);
1716                        }
1717                } else {
1718                        if (file->is_renamed) {
1719                                putc('\0', options->file);
1720                                write_name_quoted(file->from_name, options->file, '\0');
1721                        }
1722                        write_name_quoted(file->name, options->file, '\0');
1723                }
1724        }
1725}
1726
1727struct dirstat_file {
1728        const char *name;
1729        unsigned long changed;
1730};
1731
1732struct dirstat_dir {
1733        struct dirstat_file *files;
1734        int alloc, nr, permille, cumulative;
1735};
1736
1737static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1738                unsigned long changed, const char *base, int baselen)
1739{
1740        unsigned long this_dir = 0;
1741        unsigned int sources = 0;
1742        const char *line_prefix = "";
1743        struct strbuf *msg = NULL;
1744
1745        if (opt->output_prefix) {
1746                msg = opt->output_prefix(opt, opt->output_prefix_data);
1747                line_prefix = msg->buf;
1748        }
1749
1750        while (dir->nr) {
1751                struct dirstat_file *f = dir->files;
1752                int namelen = strlen(f->name);
1753                unsigned long this;
1754                char *slash;
1755
1756                if (namelen < baselen)
1757                        break;
1758                if (memcmp(f->name, base, baselen))
1759                        break;
1760                slash = strchr(f->name + baselen, '/');
1761                if (slash) {
1762                        int newbaselen = slash + 1 - f->name;
1763                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1764                        sources++;
1765                } else {
1766                        this = f->changed;
1767                        dir->files++;
1768                        dir->nr--;
1769                        sources += 2;
1770                }
1771                this_dir += this;
1772        }
1773
1774        /*
1775         * We don't report dirstat's for
1776         *  - the top level
1777         *  - or cases where everything came from a single directory
1778         *    under this directory (sources == 1).
1779         */
1780        if (baselen && sources != 1) {
1781                if (this_dir) {
1782                        int permille = this_dir * 1000 / changed;
1783                        if (permille >= dir->permille) {
1784                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1785                                        permille / 10, permille % 10, baselen, base);
1786                                if (!dir->cumulative)
1787                                        return 0;
1788                        }
1789                }
1790        }
1791        return this_dir;
1792}
1793
1794static int dirstat_compare(const void *_a, const void *_b)
1795{
1796        const struct dirstat_file *a = _a;
1797        const struct dirstat_file *b = _b;
1798        return strcmp(a->name, b->name);
1799}
1800
1801static void show_dirstat(struct diff_options *options)
1802{
1803        int i;
1804        unsigned long changed;
1805        struct dirstat_dir dir;
1806        struct diff_queue_struct *q = &diff_queued_diff;
1807
1808        dir.files = NULL;
1809        dir.alloc = 0;
1810        dir.nr = 0;
1811        dir.permille = options->dirstat_permille;
1812        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1813
1814        changed = 0;
1815        for (i = 0; i < q->nr; i++) {
1816                struct diff_filepair *p = q->queue[i];
1817                const char *name;
1818                unsigned long copied, added, damage;
1819                int content_changed;
1820
1821                name = p->two->path ? p->two->path : p->one->path;
1822
1823                if (p->one->sha1_valid && p->two->sha1_valid)
1824                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1825                else
1826                        content_changed = 1;
1827
1828                if (!content_changed) {
1829                        /*
1830                         * The SHA1 has not changed, so pre-/post-content is
1831                         * identical. We can therefore skip looking at the
1832                         * file contents altogether.
1833                         */
1834                        damage = 0;
1835                        goto found_damage;
1836                }
1837
1838                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1839                        /*
1840                         * In --dirstat-by-file mode, we don't really need to
1841                         * look at the actual file contents at all.
1842                         * The fact that the SHA1 changed is enough for us to
1843                         * add this file to the list of results
1844                         * (with each file contributing equal damage).
1845                         */
1846                        damage = 1;
1847                        goto found_damage;
1848                }
1849
1850                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1851                        diff_populate_filespec(p->one, 0);
1852                        diff_populate_filespec(p->two, 0);
1853                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1854                                               &copied, &added);
1855                        diff_free_filespec_data(p->one);
1856                        diff_free_filespec_data(p->two);
1857                } else if (DIFF_FILE_VALID(p->one)) {
1858                        diff_populate_filespec(p->one, 1);
1859                        copied = added = 0;
1860                        diff_free_filespec_data(p->one);
1861                } else if (DIFF_FILE_VALID(p->two)) {
1862                        diff_populate_filespec(p->two, 1);
1863                        copied = 0;
1864                        added = p->two->size;
1865                        diff_free_filespec_data(p->two);
1866                } else
1867                        continue;
1868
1869                /*
1870                 * Original minus copied is the removed material,
1871                 * added is the new material.  They are both damages
1872                 * made to the preimage.
1873                 * If the resulting damage is zero, we know that
1874                 * diffcore_count_changes() considers the two entries to
1875                 * be identical, but since content_changed is true, we
1876                 * know that there must have been _some_ kind of change,
1877                 * so we force all entries to have damage > 0.
1878                 */
1879                damage = (p->one->size - copied) + added;
1880                if (!damage)
1881                        damage = 1;
1882
1883found_damage:
1884                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1885                dir.files[dir.nr].name = name;
1886                dir.files[dir.nr].changed = damage;
1887                changed += damage;
1888                dir.nr++;
1889        }
1890
1891        /* This can happen even with many files, if everything was renames */
1892        if (!changed)
1893                return;
1894
1895        /* Show all directories with more than x% of the changes */
1896        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1897        gather_dirstat(options, &dir, changed, "", 0);
1898}
1899
1900static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1901{
1902        int i;
1903        unsigned long changed;
1904        struct dirstat_dir dir;
1905
1906        if (data->nr == 0)
1907                return;
1908
1909        dir.files = NULL;
1910        dir.alloc = 0;
1911        dir.nr = 0;
1912        dir.permille = options->dirstat_permille;
1913        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1914
1915        changed = 0;
1916        for (i = 0; i < data->nr; i++) {
1917                struct diffstat_file *file = data->files[i];
1918                unsigned long damage = file->added + file->deleted;
1919                if (file->is_binary)
1920                        /*
1921                         * binary files counts bytes, not lines. Must find some
1922                         * way to normalize binary bytes vs. textual lines.
1923                         * The following heuristic assumes that there are 64
1924                         * bytes per "line".
1925                         * This is stupid and ugly, but very cheap...
1926                         */
1927                        damage = (damage + 63) / 64;
1928                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1929                dir.files[dir.nr].name = file->name;
1930                dir.files[dir.nr].changed = damage;
1931                changed += damage;
1932                dir.nr++;
1933        }
1934
1935        /* This can happen even with many files, if everything was renames */
1936        if (!changed)
1937                return;
1938
1939        /* Show all directories with more than x% of the changes */
1940        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1941        gather_dirstat(options, &dir, changed, "", 0);
1942}
1943
1944static void free_diffstat_info(struct diffstat_t *diffstat)
1945{
1946        int i;
1947        for (i = 0; i < diffstat->nr; i++) {
1948                struct diffstat_file *f = diffstat->files[i];
1949                if (f->name != f->print_name)
1950                        free(f->print_name);
1951                free(f->name);
1952                free(f->from_name);
1953                free(f);
1954        }
1955        free(diffstat->files);
1956}
1957
1958struct checkdiff_t {
1959        const char *filename;
1960        int lineno;
1961        int conflict_marker_size;
1962        struct diff_options *o;
1963        unsigned ws_rule;
1964        unsigned status;
1965};
1966
1967static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1968{
1969        char firstchar;
1970        int cnt;
1971
1972        if (len < marker_size + 1)
1973                return 0;
1974        firstchar = line[0];
1975        switch (firstchar) {
1976        case '=': case '>': case '<': case '|':
1977                break;
1978        default:
1979                return 0;
1980        }
1981        for (cnt = 1; cnt < marker_size; cnt++)
1982                if (line[cnt] != firstchar)
1983                        return 0;
1984        /* line[1] thru line[marker_size-1] are same as firstchar */
1985        if (len < marker_size + 1 || !isspace(line[marker_size]))
1986                return 0;
1987        return 1;
1988}
1989
1990static void checkdiff_consume(void *priv, char *line, unsigned long len)
1991{
1992        struct checkdiff_t *data = priv;
1993        int marker_size = data->conflict_marker_size;
1994        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1995        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1996        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1997        char *err;
1998        char *line_prefix = "";
1999        struct strbuf *msgbuf;
2000
2001        assert(data->o);
2002        if (data->o->output_prefix) {
2003                msgbuf = data->o->output_prefix(data->o,
2004                        data->o->output_prefix_data);
2005                line_prefix = msgbuf->buf;
2006        }
2007
2008        if (line[0] == '+') {
2009                unsigned bad;
2010                data->lineno++;
2011                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2012                        data->status |= 1;
2013                        fprintf(data->o->file,
2014                                "%s%s:%d: leftover conflict marker\n",
2015                                line_prefix, data->filename, data->lineno);
2016                }
2017                bad = ws_check(line + 1, len - 1, data->ws_rule);
2018                if (!bad)
2019                        return;
2020                data->status |= bad;
2021                err = whitespace_error_string(bad);
2022                fprintf(data->o->file, "%s%s:%d: %s.\n",
2023                        line_prefix, data->filename, data->lineno, err);
2024                free(err);
2025                emit_line(data->o, set, reset, line, 1);
2026                ws_check_emit(line + 1, len - 1, data->ws_rule,
2027                              data->o->file, set, reset, ws);
2028        } else if (line[0] == ' ') {
2029                data->lineno++;
2030        } else if (line[0] == '@') {
2031                char *plus = strchr(line, '+');
2032                if (plus)
2033                        data->lineno = strtol(plus, NULL, 10) - 1;
2034                else
2035                        die("invalid diff");
2036        }
2037}
2038
2039static unsigned char *deflate_it(char *data,
2040                                 unsigned long size,
2041                                 unsigned long *result_size)
2042{
2043        int bound;
2044        unsigned char *deflated;
2045        git_zstream stream;
2046
2047        memset(&stream, 0, sizeof(stream));
2048        git_deflate_init(&stream, zlib_compression_level);
2049        bound = git_deflate_bound(&stream, size);
2050        deflated = xmalloc(bound);
2051        stream.next_out = deflated;
2052        stream.avail_out = bound;
2053
2054        stream.next_in = (unsigned char *)data;
2055        stream.avail_in = size;
2056        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2057                ; /* nothing */
2058        git_deflate_end(&stream);
2059        *result_size = stream.total_out;
2060        return deflated;
2061}
2062
2063static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2064{
2065        void *cp;
2066        void *delta;
2067        void *deflated;
2068        void *data;
2069        unsigned long orig_size;
2070        unsigned long delta_size;
2071        unsigned long deflate_size;
2072        unsigned long data_size;
2073
2074        /* We could do deflated delta, or we could do just deflated two,
2075         * whichever is smaller.
2076         */
2077        delta = NULL;
2078        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2079        if (one->size && two->size) {
2080                delta = diff_delta(one->ptr, one->size,
2081                                   two->ptr, two->size,
2082                                   &delta_size, deflate_size);
2083                if (delta) {
2084                        void *to_free = delta;
2085                        orig_size = delta_size;
2086                        delta = deflate_it(delta, delta_size, &delta_size);
2087                        free(to_free);
2088                }
2089        }
2090
2091        if (delta && delta_size < deflate_size) {
2092                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2093                free(deflated);
2094                data = delta;
2095                data_size = delta_size;
2096        }
2097        else {
2098                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2099                free(delta);
2100                data = deflated;
2101                data_size = deflate_size;
2102        }
2103
2104        /* emit data encoded in base85 */
2105        cp = data;
2106        while (data_size) {
2107                int bytes = (52 < data_size) ? 52 : data_size;
2108                char line[70];
2109                data_size -= bytes;
2110                if (bytes <= 26)
2111                        line[0] = bytes + 'A' - 1;
2112                else
2113                        line[0] = bytes - 26 + 'a' - 1;
2114                encode_85(line + 1, cp, bytes);
2115                cp = (char *) cp + bytes;
2116                fprintf(file, "%s", prefix);
2117                fputs(line, file);
2118                fputc('\n', file);
2119        }
2120        fprintf(file, "%s\n", prefix);
2121        free(data);
2122}
2123
2124static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2125{
2126        fprintf(file, "%sGIT binary patch\n", prefix);
2127        emit_binary_diff_body(file, one, two, prefix);
2128        emit_binary_diff_body(file, two, one, prefix);
2129}
2130
2131int diff_filespec_is_binary(struct diff_filespec *one)
2132{
2133        if (one->is_binary == -1) {
2134                diff_filespec_load_driver(one);
2135                if (one->driver->binary != -1)
2136                        one->is_binary = one->driver->binary;
2137                else {
2138                        if (!one->data && DIFF_FILE_VALID(one))
2139                                diff_populate_filespec(one, 0);
2140                        if (one->data)
2141                                one->is_binary = buffer_is_binary(one->data,
2142                                                one->size);
2143                        if (one->is_binary == -1)
2144                                one->is_binary = 0;
2145                }
2146        }
2147        return one->is_binary;
2148}
2149
2150static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2151{
2152        diff_filespec_load_driver(one);
2153        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2154}
2155
2156void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2157{
2158        if (!options->a_prefix)
2159                options->a_prefix = a;
2160        if (!options->b_prefix)
2161                options->b_prefix = b;
2162}
2163
2164struct userdiff_driver *get_textconv(struct diff_filespec *one)
2165{
2166        if (!DIFF_FILE_VALID(one))
2167                return NULL;
2168
2169        diff_filespec_load_driver(one);
2170        return userdiff_get_textconv(one->driver);
2171}
2172
2173static void builtin_diff(const char *name_a,
2174                         const char *name_b,
2175                         struct diff_filespec *one,
2176                         struct diff_filespec *two,
2177                         const char *xfrm_msg,
2178                         int must_show_header,
2179                         struct diff_options *o,
2180                         int complete_rewrite)
2181{
2182        mmfile_t mf1, mf2;
2183        const char *lbl[2];
2184        char *a_one, *b_two;
2185        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2186        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2187        const char *a_prefix, *b_prefix;
2188        struct userdiff_driver *textconv_one = NULL;
2189        struct userdiff_driver *textconv_two = NULL;
2190        struct strbuf header = STRBUF_INIT;
2191        struct strbuf *msgbuf;
2192        char *line_prefix = "";
2193
2194        if (o->output_prefix) {
2195                msgbuf = o->output_prefix(o, o->output_prefix_data);
2196                line_prefix = msgbuf->buf;
2197        }
2198
2199        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2200                        (!one->mode || S_ISGITLINK(one->mode)) &&
2201                        (!two->mode || S_ISGITLINK(two->mode))) {
2202                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2203                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2204                show_submodule_summary(o->file, one ? one->path : two->path,
2205                                one->sha1, two->sha1, two->dirty_submodule,
2206                                del, add, reset);
2207                return;
2208        }
2209
2210        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2211                textconv_one = get_textconv(one);
2212                textconv_two = get_textconv(two);
2213        }
2214
2215        diff_set_mnemonic_prefix(o, "a/", "b/");
2216        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2217                a_prefix = o->b_prefix;
2218                b_prefix = o->a_prefix;
2219        } else {
2220                a_prefix = o->a_prefix;
2221                b_prefix = o->b_prefix;
2222        }
2223
2224        /* Never use a non-valid filename anywhere if at all possible */
2225        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2226        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2227
2228        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2229        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2230        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2231        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2232        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2233        if (lbl[0][0] == '/') {
2234                /* /dev/null */
2235                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2236                if (xfrm_msg)
2237                        strbuf_addstr(&header, xfrm_msg);
2238                must_show_header = 1;
2239        }
2240        else if (lbl[1][0] == '/') {
2241                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2242                if (xfrm_msg)
2243                        strbuf_addstr(&header, xfrm_msg);
2244                must_show_header = 1;
2245        }
2246        else {
2247                if (one->mode != two->mode) {
2248                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2249                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2250                        must_show_header = 1;
2251                }
2252                if (xfrm_msg)
2253                        strbuf_addstr(&header, xfrm_msg);
2254
2255                /*
2256                 * we do not run diff between different kind
2257                 * of objects.
2258                 */
2259                if ((one->mode ^ two->mode) & S_IFMT)
2260                        goto free_ab_and_return;
2261                if (complete_rewrite &&
2262                    (textconv_one || !diff_filespec_is_binary(one)) &&
2263                    (textconv_two || !diff_filespec_is_binary(two))) {
2264                        fprintf(o->file, "%s", header.buf);
2265                        strbuf_reset(&header);
2266                        emit_rewrite_diff(name_a, name_b, one, two,
2267                                                textconv_one, textconv_two, o);
2268                        o->found_changes = 1;
2269                        goto free_ab_and_return;
2270                }
2271        }
2272
2273        if (o->irreversible_delete && lbl[1][0] == '/') {
2274                fprintf(o->file, "%s", header.buf);
2275                strbuf_reset(&header);
2276                goto free_ab_and_return;
2277        } else if (!DIFF_OPT_TST(o, TEXT) &&
2278            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2279              (!textconv_two && diff_filespec_is_binary(two)) )) {
2280                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2281                        die("unable to read files to diff");
2282                /* Quite common confusing case */
2283                if (mf1.size == mf2.size &&
2284                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2285                        if (must_show_header)
2286                                fprintf(o->file, "%s", header.buf);
2287                        goto free_ab_and_return;
2288                }
2289                fprintf(o->file, "%s", header.buf);
2290                strbuf_reset(&header);
2291                if (DIFF_OPT_TST(o, BINARY))
2292                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2293                else
2294                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2295                                line_prefix, lbl[0], lbl[1]);
2296                o->found_changes = 1;
2297        } else {
2298                /* Crazy xdl interfaces.. */
2299                const char *diffopts = getenv("GIT_DIFF_OPTS");
2300                xpparam_t xpp;
2301                xdemitconf_t xecfg;
2302                struct emit_callback ecbdata;
2303                const struct userdiff_funcname *pe;
2304
2305                if (must_show_header) {
2306                        fprintf(o->file, "%s", header.buf);
2307                        strbuf_reset(&header);
2308                }
2309
2310                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2311                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2312
2313                pe = diff_funcname_pattern(one);
2314                if (!pe)
2315                        pe = diff_funcname_pattern(two);
2316
2317                memset(&xpp, 0, sizeof(xpp));
2318                memset(&xecfg, 0, sizeof(xecfg));
2319                memset(&ecbdata, 0, sizeof(ecbdata));
2320                ecbdata.label_path = lbl;
2321                ecbdata.color_diff = want_color(o->use_color);
2322                ecbdata.found_changesp = &o->found_changes;
2323                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2324                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2325                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2326                ecbdata.opt = o;
2327                ecbdata.header = header.len ? &header : NULL;
2328                xpp.flags = o->xdl_opts;
2329                xecfg.ctxlen = o->context;
2330                xecfg.interhunkctxlen = o->interhunkcontext;
2331                xecfg.flags = XDL_EMIT_FUNCNAMES;
2332                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2333                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2334                if (pe)
2335                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2336                if (!diffopts)
2337                        ;
2338                else if (!prefixcmp(diffopts, "--unified="))
2339                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2340                else if (!prefixcmp(diffopts, "-u"))
2341                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2342                if (o->word_diff)
2343                        init_diff_words_data(&ecbdata, o, one, two);
2344                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2345                              &xpp, &xecfg);
2346                if (o->word_diff)
2347                        free_diff_words_data(&ecbdata);
2348                if (textconv_one)
2349                        free(mf1.ptr);
2350                if (textconv_two)
2351                        free(mf2.ptr);
2352                xdiff_clear_find_func(&xecfg);
2353        }
2354
2355 free_ab_and_return:
2356        strbuf_release(&header);
2357        diff_free_filespec_data(one);
2358        diff_free_filespec_data(two);
2359        free(a_one);
2360        free(b_two);
2361        return;
2362}
2363
2364static void builtin_diffstat(const char *name_a, const char *name_b,
2365                             struct diff_filespec *one,
2366                             struct diff_filespec *two,
2367                             struct diffstat_t *diffstat,
2368                             struct diff_options *o,
2369                             int complete_rewrite)
2370{
2371        mmfile_t mf1, mf2;
2372        struct diffstat_file *data;
2373
2374        data = diffstat_add(diffstat, name_a, name_b);
2375
2376        if (!one || !two) {
2377                data->is_unmerged = 1;
2378                return;
2379        }
2380
2381        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2382                data->is_binary = 1;
2383                if (!hashcmp(one->sha1, two->sha1)) {
2384                        data->added = 0;
2385                        data->deleted = 0;
2386                } else {
2387                        data->added = diff_filespec_size(two);
2388                        data->deleted = diff_filespec_size(one);
2389                }
2390        }
2391
2392        else if (complete_rewrite) {
2393                diff_populate_filespec(one, 0);
2394                diff_populate_filespec(two, 0);
2395                data->deleted = count_lines(one->data, one->size);
2396                data->added = count_lines(two->data, two->size);
2397        }
2398
2399        else {
2400                /* Crazy xdl interfaces.. */
2401                xpparam_t xpp;
2402                xdemitconf_t xecfg;
2403
2404                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2405                        die("unable to read files to diff");
2406
2407                memset(&xpp, 0, sizeof(xpp));
2408                memset(&xecfg, 0, sizeof(xecfg));
2409                xpp.flags = o->xdl_opts;
2410                xecfg.ctxlen = o->context;
2411                xecfg.interhunkctxlen = o->interhunkcontext;
2412                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2413                              &xpp, &xecfg);
2414        }
2415
2416        diff_free_filespec_data(one);
2417        diff_free_filespec_data(two);
2418}
2419
2420static void builtin_checkdiff(const char *name_a, const char *name_b,
2421                              const char *attr_path,
2422                              struct diff_filespec *one,
2423                              struct diff_filespec *two,
2424                              struct diff_options *o)
2425{
2426        mmfile_t mf1, mf2;
2427        struct checkdiff_t data;
2428
2429        if (!two)
2430                return;
2431
2432        memset(&data, 0, sizeof(data));
2433        data.filename = name_b ? name_b : name_a;
2434        data.lineno = 0;
2435        data.o = o;
2436        data.ws_rule = whitespace_rule(attr_path);
2437        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2438
2439        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2440                die("unable to read files to diff");
2441
2442        /*
2443         * All the other codepaths check both sides, but not checking
2444         * the "old" side here is deliberate.  We are checking the newly
2445         * introduced changes, and as long as the "new" side is text, we
2446         * can and should check what it introduces.
2447         */
2448        if (diff_filespec_is_binary(two))
2449                goto free_and_return;
2450        else {
2451                /* Crazy xdl interfaces.. */
2452                xpparam_t xpp;
2453                xdemitconf_t xecfg;
2454
2455                memset(&xpp, 0, sizeof(xpp));
2456                memset(&xecfg, 0, sizeof(xecfg));
2457                xecfg.ctxlen = 1; /* at least one context line */
2458                xpp.flags = 0;
2459                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2460                              &xpp, &xecfg);
2461
2462                if (data.ws_rule & WS_BLANK_AT_EOF) {
2463                        struct emit_callback ecbdata;
2464                        int blank_at_eof;
2465
2466                        ecbdata.ws_rule = data.ws_rule;
2467                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2468                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2469
2470                        if (blank_at_eof) {
2471                                static char *err;
2472                                if (!err)
2473                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2474                                fprintf(o->file, "%s:%d: %s.\n",
2475                                        data.filename, blank_at_eof, err);
2476                                data.status = 1; /* report errors */
2477                        }
2478                }
2479        }
2480 free_and_return:
2481        diff_free_filespec_data(one);
2482        diff_free_filespec_data(two);
2483        if (data.status)
2484                DIFF_OPT_SET(o, CHECK_FAILED);
2485}
2486
2487struct diff_filespec *alloc_filespec(const char *path)
2488{
2489        int namelen = strlen(path);
2490        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2491
2492        memset(spec, 0, sizeof(*spec));
2493        spec->path = (char *)(spec + 1);
2494        memcpy(spec->path, path, namelen+1);
2495        spec->count = 1;
2496        spec->is_binary = -1;
2497        return spec;
2498}
2499
2500void free_filespec(struct diff_filespec *spec)
2501{
2502        if (!--spec->count) {
2503                diff_free_filespec_data(spec);
2504                free(spec);
2505        }
2506}
2507
2508void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2509                   unsigned short mode)
2510{
2511        if (mode) {
2512                spec->mode = canon_mode(mode);
2513                hashcpy(spec->sha1, sha1);
2514                spec->sha1_valid = !is_null_sha1(sha1);
2515        }
2516}
2517
2518/*
2519 * Given a name and sha1 pair, if the index tells us the file in
2520 * the work tree has that object contents, return true, so that
2521 * prepare_temp_file() does not have to inflate and extract.
2522 */
2523static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2524{
2525        struct cache_entry *ce;
2526        struct stat st;
2527        int pos, len;
2528
2529        /*
2530         * We do not read the cache ourselves here, because the
2531         * benchmark with my previous version that always reads cache
2532         * shows that it makes things worse for diff-tree comparing
2533         * two linux-2.6 kernel trees in an already checked out work
2534         * tree.  This is because most diff-tree comparisons deal with
2535         * only a small number of files, while reading the cache is
2536         * expensive for a large project, and its cost outweighs the
2537         * savings we get by not inflating the object to a temporary
2538         * file.  Practically, this code only helps when we are used
2539         * by diff-cache --cached, which does read the cache before
2540         * calling us.
2541         */
2542        if (!active_cache)
2543                return 0;
2544
2545        /* We want to avoid the working directory if our caller
2546         * doesn't need the data in a normal file, this system
2547         * is rather slow with its stat/open/mmap/close syscalls,
2548         * and the object is contained in a pack file.  The pack
2549         * is probably already open and will be faster to obtain
2550         * the data through than the working directory.  Loose
2551         * objects however would tend to be slower as they need
2552         * to be individually opened and inflated.
2553         */
2554        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2555                return 0;
2556
2557        len = strlen(name);
2558        pos = cache_name_pos(name, len);
2559        if (pos < 0)
2560                return 0;
2561        ce = active_cache[pos];
2562
2563        /*
2564         * This is not the sha1 we are looking for, or
2565         * unreusable because it is not a regular file.
2566         */
2567        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2568                return 0;
2569
2570        /*
2571         * If ce is marked as "assume unchanged", there is no
2572         * guarantee that work tree matches what we are looking for.
2573         */
2574        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2575                return 0;
2576
2577        /*
2578         * If ce matches the file in the work tree, we can reuse it.
2579         */
2580        if (ce_uptodate(ce) ||
2581            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2582                return 1;
2583
2584        return 0;
2585}
2586
2587static int populate_from_stdin(struct diff_filespec *s)
2588{
2589        struct strbuf buf = STRBUF_INIT;
2590        size_t size = 0;
2591
2592        if (strbuf_read(&buf, 0, 0) < 0)
2593                return error("error while reading from stdin %s",
2594                                     strerror(errno));
2595
2596        s->should_munmap = 0;
2597        s->data = strbuf_detach(&buf, &size);
2598        s->size = size;
2599        s->should_free = 1;
2600        return 0;
2601}
2602
2603static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2604{
2605        int len;
2606        char *data = xmalloc(100), *dirty = "";
2607
2608        /* Are we looking at the work tree? */
2609        if (s->dirty_submodule)
2610                dirty = "-dirty";
2611
2612        len = snprintf(data, 100,
2613                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2614        s->data = data;
2615        s->size = len;
2616        s->should_free = 1;
2617        if (size_only) {
2618                s->data = NULL;
2619                free(data);
2620        }
2621        return 0;
2622}
2623
2624/*
2625 * While doing rename detection and pickaxe operation, we may need to
2626 * grab the data for the blob (or file) for our own in-core comparison.
2627 * diff_filespec has data and size fields for this purpose.
2628 */
2629int diff_populate_filespec(struct diff_filespec *s, int size_only)
2630{
2631        int err = 0;
2632        if (!DIFF_FILE_VALID(s))
2633                die("internal error: asking to populate invalid file.");
2634        if (S_ISDIR(s->mode))
2635                return -1;
2636
2637        if (s->data)
2638                return 0;
2639
2640        if (size_only && 0 < s->size)
2641                return 0;
2642
2643        if (S_ISGITLINK(s->mode))
2644                return diff_populate_gitlink(s, size_only);
2645
2646        if (!s->sha1_valid ||
2647            reuse_worktree_file(s->path, s->sha1, 0)) {
2648                struct strbuf buf = STRBUF_INIT;
2649                struct stat st;
2650                int fd;
2651
2652                if (!strcmp(s->path, "-"))
2653                        return populate_from_stdin(s);
2654
2655                if (lstat(s->path, &st) < 0) {
2656                        if (errno == ENOENT) {
2657                        err_empty:
2658                                err = -1;
2659                        empty:
2660                                s->data = (char *)"";
2661                                s->size = 0;
2662                                return err;
2663                        }
2664                }
2665                s->size = xsize_t(st.st_size);
2666                if (!s->size)
2667                        goto empty;
2668                if (S_ISLNK(st.st_mode)) {
2669                        struct strbuf sb = STRBUF_INIT;
2670
2671                        if (strbuf_readlink(&sb, s->path, s->size))
2672                                goto err_empty;
2673                        s->size = sb.len;
2674                        s->data = strbuf_detach(&sb, NULL);
2675                        s->should_free = 1;
2676                        return 0;
2677                }
2678                if (size_only)
2679                        return 0;
2680                fd = open(s->path, O_RDONLY);
2681                if (fd < 0)
2682                        goto err_empty;
2683                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2684                close(fd);
2685                s->should_munmap = 1;
2686
2687                /*
2688                 * Convert from working tree format to canonical git format
2689                 */
2690                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2691                        size_t size = 0;
2692                        munmap(s->data, s->size);
2693                        s->should_munmap = 0;
2694                        s->data = strbuf_detach(&buf, &size);
2695                        s->size = size;
2696                        s->should_free = 1;
2697                }
2698        }
2699        else {
2700                enum object_type type;
2701                if (size_only) {
2702                        type = sha1_object_info(s->sha1, &s->size);
2703                        if (type < 0)
2704                                die("unable to read %s", sha1_to_hex(s->sha1));
2705                } else {
2706                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2707                        if (!s->data)
2708                                die("unable to read %s", sha1_to_hex(s->sha1));
2709                        s->should_free = 1;
2710                }
2711        }
2712        return 0;
2713}
2714
2715void diff_free_filespec_blob(struct diff_filespec *s)
2716{
2717        if (s->should_free)
2718                free(s->data);
2719        else if (s->should_munmap)
2720                munmap(s->data, s->size);
2721
2722        if (s->should_free || s->should_munmap) {
2723                s->should_free = s->should_munmap = 0;
2724                s->data = NULL;
2725        }
2726}
2727
2728void diff_free_filespec_data(struct diff_filespec *s)
2729{
2730        diff_free_filespec_blob(s);
2731        free(s->cnt_data);
2732        s->cnt_data = NULL;
2733}
2734
2735static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2736                           void *blob,
2737                           unsigned long size,
2738                           const unsigned char *sha1,
2739                           int mode)
2740{
2741        int fd;
2742        struct strbuf buf = STRBUF_INIT;
2743        struct strbuf template = STRBUF_INIT;
2744        char *path_dup = xstrdup(path);
2745        const char *base = basename(path_dup);
2746
2747        /* Generate "XXXXXX_basename.ext" */
2748        strbuf_addstr(&template, "XXXXXX_");
2749        strbuf_addstr(&template, base);
2750
2751        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2752                        strlen(base) + 1);
2753        if (fd < 0)
2754                die_errno("unable to create temp-file");
2755        if (convert_to_working_tree(path,
2756                        (const char *)blob, (size_t)size, &buf)) {
2757                blob = buf.buf;
2758                size = buf.len;
2759        }
2760        if (write_in_full(fd, blob, size) != size)
2761                die_errno("unable to write temp-file");
2762        close(fd);
2763        temp->name = temp->tmp_path;
2764        strcpy(temp->hex, sha1_to_hex(sha1));
2765        temp->hex[40] = 0;
2766        sprintf(temp->mode, "%06o", mode);
2767        strbuf_release(&buf);
2768        strbuf_release(&template);
2769        free(path_dup);
2770}
2771
2772static struct diff_tempfile *prepare_temp_file(const char *name,
2773                struct diff_filespec *one)
2774{
2775        struct diff_tempfile *temp = claim_diff_tempfile();
2776
2777        if (!DIFF_FILE_VALID(one)) {
2778        not_a_valid_file:
2779                /* A '-' entry produces this for file-2, and
2780                 * a '+' entry produces this for file-1.
2781                 */
2782                temp->name = "/dev/null";
2783                strcpy(temp->hex, ".");
2784                strcpy(temp->mode, ".");
2785                return temp;
2786        }
2787
2788        if (!remove_tempfile_installed) {
2789                atexit(remove_tempfile);
2790                sigchain_push_common(remove_tempfile_on_signal);
2791                remove_tempfile_installed = 1;
2792        }
2793
2794        if (!one->sha1_valid ||
2795            reuse_worktree_file(name, one->sha1, 1)) {
2796                struct stat st;
2797                if (lstat(name, &st) < 0) {
2798                        if (errno == ENOENT)
2799                                goto not_a_valid_file;
2800                        die_errno("stat(%s)", name);
2801                }
2802                if (S_ISLNK(st.st_mode)) {
2803                        struct strbuf sb = STRBUF_INIT;
2804                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2805                                die_errno("readlink(%s)", name);
2806                        prep_temp_blob(name, temp, sb.buf, sb.len,
2807                                       (one->sha1_valid ?
2808                                        one->sha1 : null_sha1),
2809                                       (one->sha1_valid ?
2810                                        one->mode : S_IFLNK));
2811                        strbuf_release(&sb);
2812                }
2813                else {
2814                        /* we can borrow from the file in the work tree */
2815                        temp->name = name;
2816                        if (!one->sha1_valid)
2817                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2818                        else
2819                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2820                        /* Even though we may sometimes borrow the
2821                         * contents from the work tree, we always want
2822                         * one->mode.  mode is trustworthy even when
2823                         * !(one->sha1_valid), as long as
2824                         * DIFF_FILE_VALID(one).
2825                         */
2826                        sprintf(temp->mode, "%06o", one->mode);
2827                }
2828                return temp;
2829        }
2830        else {
2831                if (diff_populate_filespec(one, 0))
2832                        die("cannot read data blob for %s", one->path);
2833                prep_temp_blob(name, temp, one->data, one->size,
2834                               one->sha1, one->mode);
2835        }
2836        return temp;
2837}
2838
2839/* An external diff command takes:
2840 *
2841 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2842 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2843 *
2844 */
2845static void run_external_diff(const char *pgm,
2846                              const char *name,
2847                              const char *other,
2848                              struct diff_filespec *one,
2849                              struct diff_filespec *two,
2850                              const char *xfrm_msg,
2851                              int complete_rewrite)
2852{
2853        const char *spawn_arg[10];
2854        int retval;
2855        const char **arg = &spawn_arg[0];
2856
2857        if (one && two) {
2858                struct diff_tempfile *temp_one, *temp_two;
2859                const char *othername = (other ? other : name);
2860                temp_one = prepare_temp_file(name, one);
2861                temp_two = prepare_temp_file(othername, two);
2862                *arg++ = pgm;
2863                *arg++ = name;
2864                *arg++ = temp_one->name;
2865                *arg++ = temp_one->hex;
2866                *arg++ = temp_one->mode;
2867                *arg++ = temp_two->name;
2868                *arg++ = temp_two->hex;
2869                *arg++ = temp_two->mode;
2870                if (other) {
2871                        *arg++ = other;
2872                        *arg++ = xfrm_msg;
2873                }
2874        } else {
2875                *arg++ = pgm;
2876                *arg++ = name;
2877        }
2878        *arg = NULL;
2879        fflush(NULL);
2880        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2881        remove_tempfile();
2882        if (retval) {
2883                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2884                exit(1);
2885        }
2886}
2887
2888static int similarity_index(struct diff_filepair *p)
2889{
2890        return p->score * 100 / MAX_SCORE;
2891}
2892
2893static void fill_metainfo(struct strbuf *msg,
2894                          const char *name,
2895                          const char *other,
2896                          struct diff_filespec *one,
2897                          struct diff_filespec *two,
2898                          struct diff_options *o,
2899                          struct diff_filepair *p,
2900                          int *must_show_header,
2901                          int use_color)
2902{
2903        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2904        const char *reset = diff_get_color(use_color, DIFF_RESET);
2905        struct strbuf *msgbuf;
2906        char *line_prefix = "";
2907
2908        *must_show_header = 1;
2909        if (o->output_prefix) {
2910                msgbuf = o->output_prefix(o, o->output_prefix_data);
2911                line_prefix = msgbuf->buf;
2912        }
2913        strbuf_init(msg, PATH_MAX * 2 + 300);
2914        switch (p->status) {
2915        case DIFF_STATUS_COPIED:
2916                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2917                            line_prefix, set, similarity_index(p));
2918                strbuf_addf(msg, "%s\n%s%scopy from ",
2919                            reset,  line_prefix, set);
2920                quote_c_style(name, msg, NULL, 0);
2921                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2922                quote_c_style(other, msg, NULL, 0);
2923                strbuf_addf(msg, "%s\n", reset);
2924                break;
2925        case DIFF_STATUS_RENAMED:
2926                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2927                            line_prefix, set, similarity_index(p));
2928                strbuf_addf(msg, "%s\n%s%srename from ",
2929                            reset, line_prefix, set);
2930                quote_c_style(name, msg, NULL, 0);
2931                strbuf_addf(msg, "%s\n%s%srename to ",
2932                            reset, line_prefix, set);
2933                quote_c_style(other, msg, NULL, 0);
2934                strbuf_addf(msg, "%s\n", reset);
2935                break;
2936        case DIFF_STATUS_MODIFIED:
2937                if (p->score) {
2938                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2939                                    line_prefix,
2940                                    set, similarity_index(p), reset);
2941                        break;
2942                }
2943                /* fallthru */
2944        default:
2945                *must_show_header = 0;
2946        }
2947        if (one && two && hashcmp(one->sha1, two->sha1)) {
2948                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2949
2950                if (DIFF_OPT_TST(o, BINARY)) {
2951                        mmfile_t mf;
2952                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2953                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2954                                abbrev = 40;
2955                }
2956                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2957                            find_unique_abbrev(one->sha1, abbrev));
2958                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2959                if (one->mode == two->mode)
2960                        strbuf_addf(msg, " %06o", one->mode);
2961                strbuf_addf(msg, "%s\n", reset);
2962        }
2963}
2964
2965static void run_diff_cmd(const char *pgm,
2966                         const char *name,
2967                         const char *other,
2968                         const char *attr_path,
2969                         struct diff_filespec *one,
2970                         struct diff_filespec *two,
2971                         struct strbuf *msg,
2972                         struct diff_options *o,
2973                         struct diff_filepair *p)
2974{
2975        const char *xfrm_msg = NULL;
2976        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2977        int must_show_header = 0;
2978
2979        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2980                pgm = NULL;
2981        else {
2982                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2983                if (drv && drv->external)
2984                        pgm = drv->external;
2985        }
2986
2987        if (msg) {
2988                /*
2989                 * don't use colors when the header is intended for an
2990                 * external diff driver
2991                 */
2992                fill_metainfo(msg, name, other, one, two, o, p,
2993                              &must_show_header,
2994                              want_color(o->use_color) && !pgm);
2995                xfrm_msg = msg->len ? msg->buf : NULL;
2996        }
2997
2998        if (pgm) {
2999                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3000                                  complete_rewrite);
3001                return;
3002        }
3003        if (one && two)
3004                builtin_diff(name, other ? other : name,
3005                             one, two, xfrm_msg, must_show_header,
3006                             o, complete_rewrite);
3007        else
3008                fprintf(o->file, "* Unmerged path %s\n", name);
3009}
3010
3011static void diff_fill_sha1_info(struct diff_filespec *one)
3012{
3013        if (DIFF_FILE_VALID(one)) {
3014                if (!one->sha1_valid) {
3015                        struct stat st;
3016                        if (!strcmp(one->path, "-")) {
3017                                hashcpy(one->sha1, null_sha1);
3018                                return;
3019                        }
3020                        if (lstat(one->path, &st) < 0)
3021                                die_errno("stat '%s'", one->path);
3022                        if (index_path(one->sha1, one->path, &st, 0))
3023                                die("cannot hash %s", one->path);
3024                }
3025        }
3026        else
3027                hashclr(one->sha1);
3028}
3029
3030static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3031{
3032        /* Strip the prefix but do not molest /dev/null and absolute paths */
3033        if (*namep && **namep != '/') {
3034                *namep += prefix_length;
3035                if (**namep == '/')
3036                        ++*namep;
3037        }
3038        if (*otherp && **otherp != '/') {
3039                *otherp += prefix_length;
3040                if (**otherp == '/')
3041                        ++*otherp;
3042        }
3043}
3044
3045static void run_diff(struct diff_filepair *p, struct diff_options *o)
3046{
3047        const char *pgm = external_diff();
3048        struct strbuf msg;
3049        struct diff_filespec *one = p->one;
3050        struct diff_filespec *two = p->two;
3051        const char *name;
3052        const char *other;
3053        const char *attr_path;
3054
3055        name  = p->one->path;
3056        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3057        attr_path = name;
3058        if (o->prefix_length)
3059                strip_prefix(o->prefix_length, &name, &other);
3060
3061        if (DIFF_PAIR_UNMERGED(p)) {
3062                run_diff_cmd(pgm, name, NULL, attr_path,
3063                             NULL, NULL, NULL, o, p);
3064                return;
3065        }
3066
3067        diff_fill_sha1_info(one);
3068        diff_fill_sha1_info(two);
3069
3070        if (!pgm &&
3071            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3072            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3073                /*
3074                 * a filepair that changes between file and symlink
3075                 * needs to be split into deletion and creation.
3076                 */
3077                struct diff_filespec *null = alloc_filespec(two->path);
3078                run_diff_cmd(NULL, name, other, attr_path,
3079                             one, null, &msg, o, p);
3080                free(null);
3081                strbuf_release(&msg);
3082
3083                null = alloc_filespec(one->path);
3084                run_diff_cmd(NULL, name, other, attr_path,
3085                             null, two, &msg, o, p);
3086                free(null);
3087        }
3088        else
3089                run_diff_cmd(pgm, name, other, attr_path,
3090                             one, two, &msg, o, p);
3091
3092        strbuf_release(&msg);
3093}
3094
3095static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3096                         struct diffstat_t *diffstat)
3097{
3098        const char *name;
3099        const char *other;
3100        int complete_rewrite = 0;
3101
3102        if (DIFF_PAIR_UNMERGED(p)) {
3103                /* unmerged */
3104                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3105                return;
3106        }
3107
3108        name = p->one->path;
3109        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3110
3111        if (o->prefix_length)
3112                strip_prefix(o->prefix_length, &name, &other);
3113
3114        diff_fill_sha1_info(p->one);
3115        diff_fill_sha1_info(p->two);
3116
3117        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3118                complete_rewrite = 1;
3119        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3120}
3121
3122static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3123{
3124        const char *name;
3125        const char *other;
3126        const char *attr_path;
3127
3128        if (DIFF_PAIR_UNMERGED(p)) {
3129                /* unmerged */
3130                return;
3131        }
3132
3133        name = p->one->path;
3134        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3135        attr_path = other ? other : name;
3136
3137        if (o->prefix_length)
3138                strip_prefix(o->prefix_length, &name, &other);
3139
3140        diff_fill_sha1_info(p->one);
3141        diff_fill_sha1_info(p->two);
3142
3143        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3144}
3145
3146void diff_setup(struct diff_options *options)
3147{
3148        memcpy(options, &default_diff_options, sizeof(*options));
3149
3150        options->file = stdout;
3151
3152        options->line_termination = '\n';
3153        options->break_opt = -1;
3154        options->rename_limit = -1;
3155        options->dirstat_permille = diff_dirstat_permille_default;
3156        options->context = 3;
3157        DIFF_OPT_SET(options, RENAME_EMPTY);
3158
3159        options->change = diff_change;
3160        options->add_remove = diff_addremove;
3161        options->use_color = diff_use_color_default;
3162        options->detect_rename = diff_detect_rename_default;
3163
3164        if (diff_no_prefix) {
3165                options->a_prefix = options->b_prefix = "";
3166        } else if (!diff_mnemonic_prefix) {
3167                options->a_prefix = "a/";
3168                options->b_prefix = "b/";
3169        }
3170}
3171
3172int diff_setup_done(struct diff_options *options)
3173{
3174        int count = 0;
3175
3176        if (options->output_format & DIFF_FORMAT_NAME)
3177                count++;
3178        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3179                count++;
3180        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3181                count++;
3182        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3183                count++;
3184        if (count > 1)
3185                die("--name-only, --name-status, --check and -s are mutually exclusive");
3186
3187        /*
3188         * Most of the time we can say "there are changes"
3189         * only by checking if there are changed paths, but
3190         * --ignore-whitespace* options force us to look
3191         * inside contents.
3192         */
3193
3194        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3195            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3196            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3197                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3198        else
3199                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3200
3201        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3202                options->detect_rename = DIFF_DETECT_COPY;
3203
3204        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3205                options->prefix = NULL;
3206        if (options->prefix)
3207                options->prefix_length = strlen(options->prefix);
3208        else
3209                options->prefix_length = 0;
3210
3211        if (options->output_format & (DIFF_FORMAT_NAME |
3212                                      DIFF_FORMAT_NAME_STATUS |
3213                                      DIFF_FORMAT_CHECKDIFF |
3214                                      DIFF_FORMAT_NO_OUTPUT))
3215                options->output_format &= ~(DIFF_FORMAT_RAW |
3216                                            DIFF_FORMAT_NUMSTAT |
3217                                            DIFF_FORMAT_DIFFSTAT |
3218                                            DIFF_FORMAT_SHORTSTAT |
3219                                            DIFF_FORMAT_DIRSTAT |
3220                                            DIFF_FORMAT_SUMMARY |
3221                                            DIFF_FORMAT_PATCH);
3222
3223        /*
3224         * These cases always need recursive; we do not drop caller-supplied
3225         * recursive bits for other formats here.
3226         */
3227        if (options->output_format & (DIFF_FORMAT_PATCH |
3228                                      DIFF_FORMAT_NUMSTAT |
3229                                      DIFF_FORMAT_DIFFSTAT |
3230                                      DIFF_FORMAT_SHORTSTAT |
3231                                      DIFF_FORMAT_DIRSTAT |
3232                                      DIFF_FORMAT_SUMMARY |
3233                                      DIFF_FORMAT_CHECKDIFF))
3234                DIFF_OPT_SET(options, RECURSIVE);
3235        /*
3236         * Also pickaxe would not work very well if you do not say recursive
3237         */
3238        if (options->pickaxe)
3239                DIFF_OPT_SET(options, RECURSIVE);
3240        /*
3241         * When patches are generated, submodules diffed against the work tree
3242         * must be checked for dirtiness too so it can be shown in the output
3243         */
3244        if (options->output_format & DIFF_FORMAT_PATCH)
3245                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3246
3247        if (options->detect_rename && options->rename_limit < 0)
3248                options->rename_limit = diff_rename_limit_default;
3249        if (options->setup & DIFF_SETUP_USE_CACHE) {
3250                if (!active_cache)
3251                        /* read-cache does not die even when it fails
3252                         * so it is safe for us to do this here.  Also
3253                         * it does not smudge active_cache or active_nr
3254                         * when it fails, so we do not have to worry about
3255                         * cleaning it up ourselves either.
3256                         */
3257                        read_cache();
3258        }
3259        if (options->abbrev <= 0 || 40 < options->abbrev)
3260                options->abbrev = 40; /* full */
3261
3262        /*
3263         * It does not make sense to show the first hit we happened
3264         * to have found.  It does not make sense not to return with
3265         * exit code in such a case either.
3266         */
3267        if (DIFF_OPT_TST(options, QUICK)) {
3268                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3269                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3270        }
3271
3272        return 0;
3273}
3274
3275static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3276{
3277        char c, *eq;
3278        int len;
3279
3280        if (*arg != '-')
3281                return 0;
3282        c = *++arg;
3283        if (!c)
3284                return 0;
3285        if (c == arg_short) {
3286                c = *++arg;
3287                if (!c)
3288                        return 1;
3289                if (val && isdigit(c)) {
3290                        char *end;
3291                        int n = strtoul(arg, &end, 10);
3292                        if (*end)
3293                                return 0;
3294                        *val = n;
3295                        return 1;
3296                }
3297                return 0;
3298        }
3299        if (c != '-')
3300                return 0;
3301        arg++;
3302        eq = strchr(arg, '=');
3303        if (eq)
3304                len = eq - arg;
3305        else
3306                len = strlen(arg);
3307        if (!len || strncmp(arg, arg_long, len))
3308                return 0;
3309        if (eq) {
3310                int n;
3311                char *end;
3312                if (!isdigit(*++eq))
3313                        return 0;
3314                n = strtoul(eq, &end, 10);
3315                if (*end)
3316                        return 0;
3317                *val = n;
3318        }
3319        return 1;
3320}
3321
3322static int diff_scoreopt_parse(const char *opt);
3323
3324static inline int short_opt(char opt, const char **argv,
3325                            const char **optarg)
3326{
3327        const char *arg = argv[0];
3328        if (arg[0] != '-' || arg[1] != opt)
3329                return 0;
3330        if (arg[2] != '\0') {
3331                *optarg = arg + 2;
3332                return 1;
3333        }
3334        if (!argv[1])
3335                die("Option '%c' requires a value", opt);
3336        *optarg = argv[1];
3337        return 2;
3338}
3339
3340int parse_long_opt(const char *opt, const char **argv,
3341                   const char **optarg)
3342{
3343        const char *arg = argv[0];
3344        if (arg[0] != '-' || arg[1] != '-')
3345                return 0;
3346        arg += strlen("--");
3347        if (prefixcmp(arg, opt))
3348                return 0;
3349        arg += strlen(opt);
3350        if (*arg == '=') { /* sticked form: --option=value */
3351                *optarg = arg + 1;
3352                return 1;
3353        }
3354        if (*arg != '\0')
3355                return 0;
3356        /* separate form: --option value */
3357        if (!argv[1])
3358                die("Option '--%s' requires a value", opt);
3359        *optarg = argv[1];
3360        return 2;
3361}
3362
3363static int stat_opt(struct diff_options *options, const char **av)
3364{
3365        const char *arg = av[0];
3366        char *end;
3367        int width = options->stat_width;
3368        int name_width = options->stat_name_width;
3369        int graph_width = options->stat_graph_width;
3370        int count = options->stat_count;
3371        int argcount = 1;
3372
3373        arg += strlen("--stat");
3374        end = (char *)arg;
3375
3376        switch (*arg) {
3377        case '-':
3378                if (!prefixcmp(arg, "-width")) {
3379                        arg += strlen("-width");
3380                        if (*arg == '=')
3381                                width = strtoul(arg + 1, &end, 10);
3382                        else if (!*arg && !av[1])
3383                                die("Option '--stat-width' requires a value");
3384                        else if (!*arg) {
3385                                width = strtoul(av[1], &end, 10);
3386                                argcount = 2;
3387                        }
3388                } else if (!prefixcmp(arg, "-name-width")) {
3389                        arg += strlen("-name-width");
3390                        if (*arg == '=')
3391                                name_width = strtoul(arg + 1, &end, 10);
3392                        else if (!*arg && !av[1])
3393                                die("Option '--stat-name-width' requires a value");
3394                        else if (!*arg) {
3395                                name_width = strtoul(av[1], &end, 10);
3396                                argcount = 2;
3397                        }
3398                } else if (!prefixcmp(arg, "-graph-width")) {
3399                        arg += strlen("-graph-width");
3400                        if (*arg == '=')
3401                                graph_width = strtoul(arg + 1, &end, 10);
3402                        else if (!*arg && !av[1])
3403                                die("Option '--stat-graph-width' requires a value");
3404                        else if (!*arg) {
3405                                graph_width = strtoul(av[1], &end, 10);
3406                                argcount = 2;
3407                        }
3408                } else if (!prefixcmp(arg, "-count")) {
3409                        arg += strlen("-count");
3410                        if (*arg == '=')
3411                                count = strtoul(arg + 1, &end, 10);
3412                        else if (!*arg && !av[1])
3413                                die("Option '--stat-count' requires a value");
3414                        else if (!*arg) {
3415                                count = strtoul(av[1], &end, 10);
3416                                argcount = 2;
3417                        }
3418                }
3419                break;
3420        case '=':
3421                width = strtoul(arg+1, &end, 10);
3422                if (*end == ',')
3423                        name_width = strtoul(end+1, &end, 10);
3424                if (*end == ',')
3425                        count = strtoul(end+1, &end, 10);
3426        }
3427
3428        /* Important! This checks all the error cases! */
3429        if (*end)
3430                return 0;
3431        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3432        options->stat_name_width = name_width;
3433        options->stat_graph_width = graph_width;
3434        options->stat_width = width;
3435        options->stat_count = count;
3436        return argcount;
3437}
3438
3439static int parse_dirstat_opt(struct diff_options *options, const char *params)
3440{
3441        struct strbuf errmsg = STRBUF_INIT;
3442        if (parse_dirstat_params(options, params, &errmsg))
3443                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3444                    errmsg.buf);
3445        strbuf_release(&errmsg);
3446        /*
3447         * The caller knows a dirstat-related option is given from the command
3448         * line; allow it to say "return this_function();"
3449         */
3450        options->output_format |= DIFF_FORMAT_DIRSTAT;
3451        return 1;
3452}
3453
3454int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3455{
3456        const char *arg = av[0];
3457        const char *optarg;
3458        int argcount;
3459
3460        /* Output format options */
3461        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3462                options->output_format |= DIFF_FORMAT_PATCH;
3463        else if (opt_arg(arg, 'U', "unified", &options->context))
3464                options->output_format |= DIFF_FORMAT_PATCH;
3465        else if (!strcmp(arg, "--raw"))
3466                options->output_format |= DIFF_FORMAT_RAW;
3467        else if (!strcmp(arg, "--patch-with-raw"))
3468                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3469        else if (!strcmp(arg, "--numstat"))
3470                options->output_format |= DIFF_FORMAT_NUMSTAT;
3471        else if (!strcmp(arg, "--shortstat"))
3472                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3473        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3474                return parse_dirstat_opt(options, "");
3475        else if (!prefixcmp(arg, "-X"))
3476                return parse_dirstat_opt(options, arg + 2);
3477        else if (!prefixcmp(arg, "--dirstat="))
3478                return parse_dirstat_opt(options, arg + 10);
3479        else if (!strcmp(arg, "--cumulative"))
3480                return parse_dirstat_opt(options, "cumulative");
3481        else if (!strcmp(arg, "--dirstat-by-file"))
3482                return parse_dirstat_opt(options, "files");
3483        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3484                parse_dirstat_opt(options, "files");
3485                return parse_dirstat_opt(options, arg + 18);
3486        }
3487        else if (!strcmp(arg, "--check"))
3488                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3489        else if (!strcmp(arg, "--summary"))
3490                options->output_format |= DIFF_FORMAT_SUMMARY;
3491        else if (!strcmp(arg, "--patch-with-stat"))
3492                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3493        else if (!strcmp(arg, "--name-only"))
3494                options->output_format |= DIFF_FORMAT_NAME;
3495        else if (!strcmp(arg, "--name-status"))
3496                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3497        else if (!strcmp(arg, "-s"))
3498                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3499        else if (!prefixcmp(arg, "--stat"))
3500                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3501                return stat_opt(options, av);
3502
3503        /* renames options */
3504        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3505                 !strcmp(arg, "--break-rewrites")) {
3506                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3507                        return error("invalid argument to -B: %s", arg+2);
3508        }
3509        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3510                 !strcmp(arg, "--find-renames")) {
3511                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3512                        return error("invalid argument to -M: %s", arg+2);
3513                options->detect_rename = DIFF_DETECT_RENAME;
3514        }
3515        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3516                options->irreversible_delete = 1;
3517        }
3518        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3519                 !strcmp(arg, "--find-copies")) {
3520                if (options->detect_rename == DIFF_DETECT_COPY)
3521                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3522                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3523                        return error("invalid argument to -C: %s", arg+2);
3524                options->detect_rename = DIFF_DETECT_COPY;
3525        }
3526        else if (!strcmp(arg, "--no-renames"))
3527                options->detect_rename = 0;
3528        else if (!strcmp(arg, "--rename-empty"))
3529                DIFF_OPT_SET(options, RENAME_EMPTY);
3530        else if (!strcmp(arg, "--no-rename-empty"))
3531                DIFF_OPT_CLR(options, RENAME_EMPTY);
3532        else if (!strcmp(arg, "--relative"))
3533                DIFF_OPT_SET(options, RELATIVE_NAME);
3534        else if (!prefixcmp(arg, "--relative=")) {
3535                DIFF_OPT_SET(options, RELATIVE_NAME);
3536                options->prefix = arg + 11;
3537        }
3538
3539        /* xdiff options */
3540        else if (!strcmp(arg, "--minimal"))
3541                DIFF_XDL_SET(options, NEED_MINIMAL);
3542        else if (!strcmp(arg, "--no-minimal"))
3543                DIFF_XDL_CLR(options, NEED_MINIMAL);
3544        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3545                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3546        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3547                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3548        else if (!strcmp(arg, "--ignore-space-at-eol"))
3549                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3550        else if (!strcmp(arg, "--patience"))
3551                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3552        else if (!strcmp(arg, "--histogram"))
3553                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3554
3555        /* flags options */
3556        else if (!strcmp(arg, "--binary")) {
3557                options->output_format |= DIFF_FORMAT_PATCH;
3558                DIFF_OPT_SET(options, BINARY);
3559        }
3560        else if (!strcmp(arg, "--full-index"))
3561                DIFF_OPT_SET(options, FULL_INDEX);
3562        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3563                DIFF_OPT_SET(options, TEXT);
3564        else if (!strcmp(arg, "-R"))
3565                DIFF_OPT_SET(options, REVERSE_DIFF);
3566        else if (!strcmp(arg, "--find-copies-harder"))
3567                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3568        else if (!strcmp(arg, "--follow"))
3569                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3570        else if (!strcmp(arg, "--color"))
3571                options->use_color = 1;
3572        else if (!prefixcmp(arg, "--color=")) {
3573                int value = git_config_colorbool(NULL, arg+8);
3574                if (value < 0)
3575                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3576                options->use_color = value;
3577        }
3578        else if (!strcmp(arg, "--no-color"))
3579                options->use_color = 0;
3580        else if (!strcmp(arg, "--color-words")) {
3581                options->use_color = 1;
3582                options->word_diff = DIFF_WORDS_COLOR;
3583        }
3584        else if (!prefixcmp(arg, "--color-words=")) {
3585                options->use_color = 1;
3586                options->word_diff = DIFF_WORDS_COLOR;
3587                options->word_regex = arg + 14;
3588        }
3589        else if (!strcmp(arg, "--word-diff")) {
3590                if (options->word_diff == DIFF_WORDS_NONE)
3591                        options->word_diff = DIFF_WORDS_PLAIN;
3592        }
3593        else if (!prefixcmp(arg, "--word-diff=")) {
3594                const char *type = arg + 12;
3595                if (!strcmp(type, "plain"))
3596                        options->word_diff = DIFF_WORDS_PLAIN;
3597                else if (!strcmp(type, "color")) {
3598                        options->use_color = 1;
3599                        options->word_diff = DIFF_WORDS_COLOR;
3600                }
3601                else if (!strcmp(type, "porcelain"))
3602                        options->word_diff = DIFF_WORDS_PORCELAIN;
3603                else if (!strcmp(type, "none"))
3604                        options->word_diff = DIFF_WORDS_NONE;
3605                else
3606                        die("bad --word-diff argument: %s", type);
3607        }
3608        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3609                if (options->word_diff == DIFF_WORDS_NONE)
3610                        options->word_diff = DIFF_WORDS_PLAIN;
3611                options->word_regex = optarg;
3612                return argcount;
3613        }
3614        else if (!strcmp(arg, "--exit-code"))
3615                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3616        else if (!strcmp(arg, "--quiet"))
3617                DIFF_OPT_SET(options, QUICK);
3618        else if (!strcmp(arg, "--ext-diff"))
3619                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3620        else if (!strcmp(arg, "--no-ext-diff"))
3621                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3622        else if (!strcmp(arg, "--textconv"))
3623                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3624        else if (!strcmp(arg, "--no-textconv"))
3625                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3626        else if (!strcmp(arg, "--ignore-submodules")) {
3627                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3628                handle_ignore_submodules_arg(options, "all");
3629        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3630                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3631                handle_ignore_submodules_arg(options, arg + 20);
3632        } else if (!strcmp(arg, "--submodule"))
3633                DIFF_OPT_SET(options, SUBMODULE_LOG);
3634        else if (!prefixcmp(arg, "--submodule=")) {
3635                if (!strcmp(arg + 12, "log"))
3636                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3637        }
3638
3639        /* misc options */
3640        else if (!strcmp(arg, "-z"))
3641                options->line_termination = 0;
3642        else if ((argcount = short_opt('l', av, &optarg))) {
3643                options->rename_limit = strtoul(optarg, NULL, 10);
3644                return argcount;
3645        }
3646        else if ((argcount = short_opt('S', av, &optarg))) {
3647                options->pickaxe = optarg;
3648                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3649                return argcount;
3650        } else if ((argcount = short_opt('G', av, &optarg))) {
3651                options->pickaxe = optarg;
3652                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3653                return argcount;
3654        }
3655        else if (!strcmp(arg, "--pickaxe-all"))
3656                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3657        else if (!strcmp(arg, "--pickaxe-regex"))
3658                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3659        else if ((argcount = short_opt('O', av, &optarg))) {
3660                options->orderfile = optarg;
3661                return argcount;
3662        }
3663        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3664                options->filter = optarg;
3665                return argcount;
3666        }
3667        else if (!strcmp(arg, "--abbrev"))
3668                options->abbrev = DEFAULT_ABBREV;
3669        else if (!prefixcmp(arg, "--abbrev=")) {
3670                options->abbrev = strtoul(arg + 9, NULL, 10);
3671                if (options->abbrev < MINIMUM_ABBREV)
3672                        options->abbrev = MINIMUM_ABBREV;
3673                else if (40 < options->abbrev)
3674                        options->abbrev = 40;
3675        }
3676        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3677                options->a_prefix = optarg;
3678                return argcount;
3679        }
3680        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3681                options->b_prefix = optarg;
3682                return argcount;
3683        }
3684        else if (!strcmp(arg, "--no-prefix"))
3685                options->a_prefix = options->b_prefix = "";
3686        else if (opt_arg(arg, '\0', "inter-hunk-context",
3687                         &options->interhunkcontext))
3688                ;
3689        else if (!strcmp(arg, "-W"))
3690                DIFF_OPT_SET(options, FUNCCONTEXT);
3691        else if (!strcmp(arg, "--function-context"))
3692                DIFF_OPT_SET(options, FUNCCONTEXT);
3693        else if (!strcmp(arg, "--no-function-context"))
3694                DIFF_OPT_CLR(options, FUNCCONTEXT);
3695        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3696                options->file = fopen(optarg, "w");
3697                if (!options->file)
3698                        die_errno("Could not open '%s'", optarg);
3699                options->close_file = 1;
3700                return argcount;
3701        } else
3702                return 0;
3703        return 1;
3704}
3705
3706int parse_rename_score(const char **cp_p)
3707{
3708        unsigned long num, scale;
3709        int ch, dot;
3710        const char *cp = *cp_p;
3711
3712        num = 0;
3713        scale = 1;
3714        dot = 0;
3715        for (;;) {
3716                ch = *cp;
3717                if ( !dot && ch == '.' ) {
3718                        scale = 1;
3719                        dot = 1;
3720                } else if ( ch == '%' ) {
3721                        scale = dot ? scale*100 : 100;
3722                        cp++;   /* % is always at the end */
3723                        break;
3724                } else if ( ch >= '0' && ch <= '9' ) {
3725                        if ( scale < 100000 ) {
3726                                scale *= 10;
3727                                num = (num*10) + (ch-'0');
3728                        }
3729                } else {
3730                        break;
3731                }
3732                cp++;
3733        }
3734        *cp_p = cp;
3735
3736        /* user says num divided by scale and we say internally that
3737         * is MAX_SCORE * num / scale.
3738         */
3739        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3740}
3741
3742static int diff_scoreopt_parse(const char *opt)
3743{
3744        int opt1, opt2, cmd;
3745
3746        if (*opt++ != '-')
3747                return -1;
3748        cmd = *opt++;
3749        if (cmd == '-') {
3750                /* convert the long-form arguments into short-form versions */
3751                if (!prefixcmp(opt, "break-rewrites")) {
3752                        opt += strlen("break-rewrites");
3753                        if (*opt == 0 || *opt++ == '=')
3754                                cmd = 'B';
3755                } else if (!prefixcmp(opt, "find-copies")) {
3756                        opt += strlen("find-copies");
3757                        if (*opt == 0 || *opt++ == '=')
3758                                cmd = 'C';
3759                } else if (!prefixcmp(opt, "find-renames")) {
3760                        opt += strlen("find-renames");
3761                        if (*opt == 0 || *opt++ == '=')
3762                                cmd = 'M';
3763                }
3764        }
3765        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3766                return -1; /* that is not a -M, -C nor -B option */
3767
3768        opt1 = parse_rename_score(&opt);
3769        if (cmd != 'B')
3770                opt2 = 0;
3771        else {
3772                if (*opt == 0)
3773                        opt2 = 0;
3774                else if (*opt != '/')
3775                        return -1; /* we expect -B80/99 or -B80 */
3776                else {
3777                        opt++;
3778                        opt2 = parse_rename_score(&opt);
3779                }
3780        }
3781        if (*opt != 0)
3782                return -1;
3783        return opt1 | (opt2 << 16);
3784}
3785
3786struct diff_queue_struct diff_queued_diff;
3787
3788void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3789{
3790        if (queue->alloc <= queue->nr) {
3791                queue->alloc = alloc_nr(queue->alloc);
3792                queue->queue = xrealloc(queue->queue,
3793                                        sizeof(dp) * queue->alloc);
3794        }
3795        queue->queue[queue->nr++] = dp;
3796}
3797
3798struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3799                                 struct diff_filespec *one,
3800                                 struct diff_filespec *two)
3801{
3802        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3803        dp->one = one;
3804        dp->two = two;
3805        if (queue)
3806                diff_q(queue, dp);
3807        return dp;
3808}
3809
3810void diff_free_filepair(struct diff_filepair *p)
3811{
3812        free_filespec(p->one);
3813        free_filespec(p->two);
3814        free(p);
3815}
3816
3817/* This is different from find_unique_abbrev() in that
3818 * it stuffs the result with dots for alignment.
3819 */
3820const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3821{
3822        int abblen;
3823        const char *abbrev;
3824        if (len == 40)
3825                return sha1_to_hex(sha1);
3826
3827        abbrev = find_unique_abbrev(sha1, len);
3828        abblen = strlen(abbrev);
3829        if (abblen < 37) {
3830                static char hex[41];
3831                if (len < abblen && abblen <= len + 2)
3832                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3833                else
3834                        sprintf(hex, "%s...", abbrev);
3835                return hex;
3836        }
3837        return sha1_to_hex(sha1);
3838}
3839
3840static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3841{
3842        int line_termination = opt->line_termination;
3843        int inter_name_termination = line_termination ? '\t' : '\0';
3844        if (opt->output_prefix) {
3845                struct strbuf *msg = NULL;
3846                msg = opt->output_prefix(opt, opt->output_prefix_data);
3847                fprintf(opt->file, "%s", msg->buf);
3848        }
3849
3850        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3851                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3852                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3853                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3854        }
3855        if (p->score) {
3856                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3857                        inter_name_termination);
3858        } else {
3859                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3860        }
3861
3862        if (p->status == DIFF_STATUS_COPIED ||
3863            p->status == DIFF_STATUS_RENAMED) {
3864                const char *name_a, *name_b;
3865                name_a = p->one->path;
3866                name_b = p->two->path;
3867                strip_prefix(opt->prefix_length, &name_a, &name_b);
3868                write_name_quoted(name_a, opt->file, inter_name_termination);
3869                write_name_quoted(name_b, opt->file, line_termination);
3870        } else {
3871                const char *name_a, *name_b;
3872                name_a = p->one->mode ? p->one->path : p->two->path;
3873                name_b = NULL;
3874                strip_prefix(opt->prefix_length, &name_a, &name_b);
3875                write_name_quoted(name_a, opt->file, line_termination);
3876        }
3877}
3878
3879int diff_unmodified_pair(struct diff_filepair *p)
3880{
3881        /* This function is written stricter than necessary to support
3882         * the currently implemented transformers, but the idea is to
3883         * let transformers to produce diff_filepairs any way they want,
3884         * and filter and clean them up here before producing the output.
3885         */
3886        struct diff_filespec *one = p->one, *two = p->two;
3887
3888        if (DIFF_PAIR_UNMERGED(p))
3889                return 0; /* unmerged is interesting */
3890
3891        /* deletion, addition, mode or type change
3892         * and rename are all interesting.
3893         */
3894        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3895            DIFF_PAIR_MODE_CHANGED(p) ||
3896            strcmp(one->path, two->path))
3897                return 0;
3898
3899        /* both are valid and point at the same path.  that is, we are
3900         * dealing with a change.
3901         */
3902        if (one->sha1_valid && two->sha1_valid &&
3903            !hashcmp(one->sha1, two->sha1) &&
3904            !one->dirty_submodule && !two->dirty_submodule)
3905                return 1; /* no change */
3906        if (!one->sha1_valid && !two->sha1_valid)
3907                return 1; /* both look at the same file on the filesystem. */
3908        return 0;
3909}
3910
3911static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3912{
3913        if (diff_unmodified_pair(p))
3914                return;
3915
3916        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3917            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3918                return; /* no tree diffs in patch format */
3919
3920        run_diff(p, o);
3921}
3922
3923static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3924                            struct diffstat_t *diffstat)
3925{
3926        if (diff_unmodified_pair(p))
3927                return;
3928
3929        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3930            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3931                return; /* no useful stat for tree diffs */
3932
3933        run_diffstat(p, o, diffstat);
3934}
3935
3936static void diff_flush_checkdiff(struct diff_filepair *p,
3937                struct diff_options *o)
3938{
3939        if (diff_unmodified_pair(p))
3940                return;
3941
3942        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3943            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3944                return; /* nothing to check in tree diffs */
3945
3946        run_checkdiff(p, o);
3947}
3948
3949int diff_queue_is_empty(void)
3950{
3951        struct diff_queue_struct *q = &diff_queued_diff;
3952        int i;
3953        for (i = 0; i < q->nr; i++)
3954                if (!diff_unmodified_pair(q->queue[i]))
3955                        return 0;
3956        return 1;
3957}
3958
3959#if DIFF_DEBUG
3960void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3961{
3962        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3963                x, one ? one : "",
3964                s->path,
3965                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3966                s->mode,
3967                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3968        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3969                x, one ? one : "",
3970                s->size, s->xfrm_flags);
3971}
3972
3973void diff_debug_filepair(const struct diff_filepair *p, int i)
3974{
3975        diff_debug_filespec(p->one, i, "one");
3976        diff_debug_filespec(p->two, i, "two");
3977        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3978                p->score, p->status ? p->status : '?',
3979                p->one->rename_used, p->broken_pair);
3980}
3981
3982void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3983{
3984        int i;
3985        if (msg)
3986                fprintf(stderr, "%s\n", msg);
3987        fprintf(stderr, "q->nr = %d\n", q->nr);
3988        for (i = 0; i < q->nr; i++) {
3989                struct diff_filepair *p = q->queue[i];
3990                diff_debug_filepair(p, i);
3991        }
3992}
3993#endif
3994
3995static void diff_resolve_rename_copy(void)
3996{
3997        int i;
3998        struct diff_filepair *p;
3999        struct diff_queue_struct *q = &diff_queued_diff;
4000
4001        diff_debug_queue("resolve-rename-copy", q);
4002
4003        for (i = 0; i < q->nr; i++) {
4004                p = q->queue[i];
4005                p->status = 0; /* undecided */
4006                if (DIFF_PAIR_UNMERGED(p))
4007                        p->status = DIFF_STATUS_UNMERGED;
4008                else if (!DIFF_FILE_VALID(p->one))
4009                        p->status = DIFF_STATUS_ADDED;
4010                else if (!DIFF_FILE_VALID(p->two))
4011                        p->status = DIFF_STATUS_DELETED;
4012                else if (DIFF_PAIR_TYPE_CHANGED(p))
4013                        p->status = DIFF_STATUS_TYPE_CHANGED;
4014
4015                /* from this point on, we are dealing with a pair
4016                 * whose both sides are valid and of the same type, i.e.
4017                 * either in-place edit or rename/copy edit.
4018                 */
4019                else if (DIFF_PAIR_RENAME(p)) {
4020                        /*
4021                         * A rename might have re-connected a broken
4022                         * pair up, causing the pathnames to be the
4023                         * same again. If so, that's not a rename at
4024                         * all, just a modification..
4025                         *
4026                         * Otherwise, see if this source was used for
4027                         * multiple renames, in which case we decrement
4028                         * the count, and call it a copy.
4029                         */
4030                        if (!strcmp(p->one->path, p->two->path))
4031                                p->status = DIFF_STATUS_MODIFIED;
4032                        else if (--p->one->rename_used > 0)
4033                                p->status = DIFF_STATUS_COPIED;
4034                        else
4035                                p->status = DIFF_STATUS_RENAMED;
4036                }
4037                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4038                         p->one->mode != p->two->mode ||
4039                         p->one->dirty_submodule ||
4040                         p->two->dirty_submodule ||
4041                         is_null_sha1(p->one->sha1))
4042                        p->status = DIFF_STATUS_MODIFIED;
4043                else {
4044                        /* This is a "no-change" entry and should not
4045                         * happen anymore, but prepare for broken callers.
4046                         */
4047                        error("feeding unmodified %s to diffcore",
4048                              p->one->path);
4049                        p->status = DIFF_STATUS_UNKNOWN;
4050                }
4051        }
4052        diff_debug_queue("resolve-rename-copy done", q);
4053}
4054
4055static int check_pair_status(struct diff_filepair *p)
4056{
4057        switch (p->status) {
4058        case DIFF_STATUS_UNKNOWN:
4059                return 0;
4060        case 0:
4061                die("internal error in diff-resolve-rename-copy");
4062        default:
4063                return 1;
4064        }
4065}
4066
4067static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4068{
4069        int fmt = opt->output_format;
4070
4071        if (fmt & DIFF_FORMAT_CHECKDIFF)
4072                diff_flush_checkdiff(p, opt);
4073        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4074                diff_flush_raw(p, opt);
4075        else if (fmt & DIFF_FORMAT_NAME) {
4076                const char *name_a, *name_b;
4077                name_a = p->two->path;
4078                name_b = NULL;
4079                strip_prefix(opt->prefix_length, &name_a, &name_b);
4080                write_name_quoted(name_a, opt->file, opt->line_termination);
4081        }
4082}
4083
4084static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4085{
4086        if (fs->mode)
4087                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4088        else
4089                fprintf(file, " %s ", newdelete);
4090        write_name_quoted(fs->path, file, '\n');
4091}
4092
4093
4094static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4095                const char *line_prefix)
4096{
4097        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4098                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4099                        p->two->mode, show_name ? ' ' : '\n');
4100                if (show_name) {
4101                        write_name_quoted(p->two->path, file, '\n');
4102                }
4103        }
4104}
4105
4106static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4107                        const char *line_prefix)
4108{
4109        char *names = pprint_rename(p->one->path, p->two->path);
4110
4111        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4112        free(names);
4113        show_mode_change(file, p, 0, line_prefix);
4114}
4115
4116static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4117{
4118        FILE *file = opt->file;
4119        char *line_prefix = "";
4120
4121        if (opt->output_prefix) {
4122                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4123                line_prefix = buf->buf;
4124        }
4125
4126        switch(p->status) {
4127        case DIFF_STATUS_DELETED:
4128                fputs(line_prefix, file);
4129                show_file_mode_name(file, "delete", p->one);
4130                break;
4131        case DIFF_STATUS_ADDED:
4132                fputs(line_prefix, file);
4133                show_file_mode_name(file, "create", p->two);
4134                break;
4135        case DIFF_STATUS_COPIED:
4136                fputs(line_prefix, file);
4137                show_rename_copy(file, "copy", p, line_prefix);
4138                break;
4139        case DIFF_STATUS_RENAMED:
4140                fputs(line_prefix, file);
4141                show_rename_copy(file, "rename", p, line_prefix);
4142                break;
4143        default:
4144                if (p->score) {
4145                        fprintf(file, "%s rewrite ", line_prefix);
4146                        write_name_quoted(p->two->path, file, ' ');
4147                        fprintf(file, "(%d%%)\n", similarity_index(p));
4148                }
4149                show_mode_change(file, p, !p->score, line_prefix);
4150                break;
4151        }
4152}
4153
4154struct patch_id_t {
4155        git_SHA_CTX *ctx;
4156        int patchlen;
4157};
4158
4159static int remove_space(char *line, int len)
4160{
4161        int i;
4162        char *dst = line;
4163        unsigned char c;
4164
4165        for (i = 0; i < len; i++)
4166                if (!isspace((c = line[i])))
4167                        *dst++ = c;
4168
4169        return dst - line;
4170}
4171
4172static void patch_id_consume(void *priv, char *line, unsigned long len)
4173{
4174        struct patch_id_t *data = priv;
4175        int new_len;
4176
4177        /* Ignore line numbers when computing the SHA1 of the patch */
4178        if (!prefixcmp(line, "@@ -"))
4179                return;
4180
4181        new_len = remove_space(line, len);
4182
4183        git_SHA1_Update(data->ctx, line, new_len);
4184        data->patchlen += new_len;
4185}
4186
4187/* returns 0 upon success, and writes result into sha1 */
4188static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4189{
4190        struct diff_queue_struct *q = &diff_queued_diff;
4191        int i;
4192        git_SHA_CTX ctx;
4193        struct patch_id_t data;
4194        char buffer[PATH_MAX * 4 + 20];
4195
4196        git_SHA1_Init(&ctx);
4197        memset(&data, 0, sizeof(struct patch_id_t));
4198        data.ctx = &ctx;
4199
4200        for (i = 0; i < q->nr; i++) {
4201                xpparam_t xpp;
4202                xdemitconf_t xecfg;
4203                mmfile_t mf1, mf2;
4204                struct diff_filepair *p = q->queue[i];
4205                int len1, len2;
4206
4207                memset(&xpp, 0, sizeof(xpp));
4208                memset(&xecfg, 0, sizeof(xecfg));
4209                if (p->status == 0)
4210                        return error("internal diff status error");
4211                if (p->status == DIFF_STATUS_UNKNOWN)
4212                        continue;
4213                if (diff_unmodified_pair(p))
4214                        continue;
4215                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4216                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4217                        continue;
4218                if (DIFF_PAIR_UNMERGED(p))
4219                        continue;
4220
4221                diff_fill_sha1_info(p->one);
4222                diff_fill_sha1_info(p->two);
4223                if (fill_mmfile(&mf1, p->one) < 0 ||
4224                                fill_mmfile(&mf2, p->two) < 0)
4225                        return error("unable to read files to diff");
4226
4227                len1 = remove_space(p->one->path, strlen(p->one->path));
4228                len2 = remove_space(p->two->path, strlen(p->two->path));
4229                if (p->one->mode == 0)
4230                        len1 = snprintf(buffer, sizeof(buffer),
4231                                        "diff--gita/%.*sb/%.*s"
4232                                        "newfilemode%06o"
4233                                        "---/dev/null"
4234                                        "+++b/%.*s",
4235                                        len1, p->one->path,
4236                                        len2, p->two->path,
4237                                        p->two->mode,
4238                                        len2, p->two->path);
4239                else if (p->two->mode == 0)
4240                        len1 = snprintf(buffer, sizeof(buffer),
4241                                        "diff--gita/%.*sb/%.*s"
4242                                        "deletedfilemode%06o"
4243                                        "---a/%.*s"
4244                                        "+++/dev/null",
4245                                        len1, p->one->path,
4246                                        len2, p->two->path,
4247                                        p->one->mode,
4248                                        len1, p->one->path);
4249                else
4250                        len1 = snprintf(buffer, sizeof(buffer),
4251                                        "diff--gita/%.*sb/%.*s"
4252                                        "---a/%.*s"
4253                                        "+++b/%.*s",
4254                                        len1, p->one->path,
4255                                        len2, p->two->path,
4256                                        len1, p->one->path,
4257                                        len2, p->two->path);
4258                git_SHA1_Update(&ctx, buffer, len1);
4259
4260                if (diff_filespec_is_binary(p->one) ||
4261                    diff_filespec_is_binary(p->two)) {
4262                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4263                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4264                        continue;
4265                }
4266
4267                xpp.flags = 0;
4268                xecfg.ctxlen = 3;
4269                xecfg.flags = 0;
4270                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4271                              &xpp, &xecfg);
4272        }
4273
4274        git_SHA1_Final(sha1, &ctx);
4275        return 0;
4276}
4277
4278int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4279{
4280        struct diff_queue_struct *q = &diff_queued_diff;
4281        int i;
4282        int result = diff_get_patch_id(options, sha1);
4283
4284        for (i = 0; i < q->nr; i++)
4285                diff_free_filepair(q->queue[i]);
4286
4287        free(q->queue);
4288        DIFF_QUEUE_CLEAR(q);
4289
4290        return result;
4291}
4292
4293static int is_summary_empty(const struct diff_queue_struct *q)
4294{
4295        int i;
4296
4297        for (i = 0; i < q->nr; i++) {
4298                const struct diff_filepair *p = q->queue[i];
4299
4300                switch (p->status) {
4301                case DIFF_STATUS_DELETED:
4302                case DIFF_STATUS_ADDED:
4303                case DIFF_STATUS_COPIED:
4304                case DIFF_STATUS_RENAMED:
4305                        return 0;
4306                default:
4307                        if (p->score)
4308                                return 0;
4309                        if (p->one->mode && p->two->mode &&
4310                            p->one->mode != p->two->mode)
4311                                return 0;
4312                        break;
4313                }
4314        }
4315        return 1;
4316}
4317
4318static const char rename_limit_warning[] =
4319"inexact rename detection was skipped due to too many files.";
4320
4321static const char degrade_cc_to_c_warning[] =
4322"only found copies from modified paths due to too many files.";
4323
4324static const char rename_limit_advice[] =
4325"you may want to set your %s variable to at least "
4326"%d and retry the command.";
4327
4328void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4329{
4330        if (degraded_cc)
4331                warning(degrade_cc_to_c_warning);
4332        else if (needed)
4333                warning(rename_limit_warning);
4334        else
4335                return;
4336        if (0 < needed && needed < 32767)
4337                warning(rename_limit_advice, varname, needed);
4338}
4339
4340void diff_flush(struct diff_options *options)
4341{
4342        struct diff_queue_struct *q = &diff_queued_diff;
4343        int i, output_format = options->output_format;
4344        int separator = 0;
4345        int dirstat_by_line = 0;
4346
4347        /*
4348         * Order: raw, stat, summary, patch
4349         * or:    name/name-status/checkdiff (other bits clear)
4350         */
4351        if (!q->nr)
4352                goto free_queue;
4353
4354        if (output_format & (DIFF_FORMAT_RAW |
4355                             DIFF_FORMAT_NAME |
4356                             DIFF_FORMAT_NAME_STATUS |
4357                             DIFF_FORMAT_CHECKDIFF)) {
4358                for (i = 0; i < q->nr; i++) {
4359                        struct diff_filepair *p = q->queue[i];
4360                        if (check_pair_status(p))
4361                                flush_one_pair(p, options);
4362                }
4363                separator++;
4364        }
4365
4366        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4367                dirstat_by_line = 1;
4368
4369        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4370            dirstat_by_line) {
4371                struct diffstat_t diffstat;
4372
4373                memset(&diffstat, 0, sizeof(struct diffstat_t));
4374                for (i = 0; i < q->nr; i++) {
4375                        struct diff_filepair *p = q->queue[i];
4376                        if (check_pair_status(p))
4377                                diff_flush_stat(p, options, &diffstat);
4378                }
4379                if (output_format & DIFF_FORMAT_NUMSTAT)
4380                        show_numstat(&diffstat, options);
4381                if (output_format & DIFF_FORMAT_DIFFSTAT)
4382                        show_stats(&diffstat, options);
4383                if (output_format & DIFF_FORMAT_SHORTSTAT)
4384                        show_shortstats(&diffstat, options);
4385                if (output_format & DIFF_FORMAT_DIRSTAT)
4386                        show_dirstat_by_line(&diffstat, options);
4387                free_diffstat_info(&diffstat);
4388                separator++;
4389        }
4390        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4391                show_dirstat(options);
4392
4393        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4394                for (i = 0; i < q->nr; i++) {
4395                        diff_summary(options, q->queue[i]);
4396                }
4397                separator++;
4398        }
4399
4400        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4401            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4402            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4403                /*
4404                 * run diff_flush_patch for the exit status. setting
4405                 * options->file to /dev/null should be safe, becaue we
4406                 * aren't supposed to produce any output anyway.
4407                 */
4408                if (options->close_file)
4409                        fclose(options->file);
4410                options->file = fopen("/dev/null", "w");
4411                if (!options->file)
4412                        die_errno("Could not open /dev/null");
4413                options->close_file = 1;
4414                for (i = 0; i < q->nr; i++) {
4415                        struct diff_filepair *p = q->queue[i];
4416                        if (check_pair_status(p))
4417                                diff_flush_patch(p, options);
4418                        if (options->found_changes)
4419                                break;
4420                }
4421        }
4422
4423        if (output_format & DIFF_FORMAT_PATCH) {
4424                if (separator) {
4425                        if (options->output_prefix) {
4426                                struct strbuf *msg = NULL;
4427                                msg = options->output_prefix(options,
4428                                        options->output_prefix_data);
4429                                fwrite(msg->buf, msg->len, 1, stdout);
4430                        }
4431                        putc(options->line_termination, options->file);
4432                        if (options->stat_sep) {
4433                                /* attach patch instead of inline */
4434                                fputs(options->stat_sep, options->file);
4435                        }
4436                }
4437
4438                for (i = 0; i < q->nr; i++) {
4439                        struct diff_filepair *p = q->queue[i];
4440                        if (check_pair_status(p))
4441                                diff_flush_patch(p, options);
4442                }
4443        }
4444
4445        if (output_format & DIFF_FORMAT_CALLBACK)
4446                options->format_callback(q, options, options->format_callback_data);
4447
4448        for (i = 0; i < q->nr; i++)
4449                diff_free_filepair(q->queue[i]);
4450free_queue:
4451        free(q->queue);
4452        DIFF_QUEUE_CLEAR(q);
4453        if (options->close_file)
4454                fclose(options->file);
4455
4456        /*
4457         * Report the content-level differences with HAS_CHANGES;
4458         * diff_addremove/diff_change does not set the bit when
4459         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4460         */
4461        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4462                if (options->found_changes)
4463                        DIFF_OPT_SET(options, HAS_CHANGES);
4464                else
4465                        DIFF_OPT_CLR(options, HAS_CHANGES);
4466        }
4467}
4468
4469static void diffcore_apply_filter(const char *filter)
4470{
4471        int i;
4472        struct diff_queue_struct *q = &diff_queued_diff;
4473        struct diff_queue_struct outq;
4474        DIFF_QUEUE_CLEAR(&outq);
4475
4476        if (!filter)
4477                return;
4478
4479        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4480                int found;
4481                for (i = found = 0; !found && i < q->nr; i++) {
4482                        struct diff_filepair *p = q->queue[i];
4483                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4484                             ((p->score &&
4485                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4486                              (!p->score &&
4487                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4488                            ((p->status != DIFF_STATUS_MODIFIED) &&
4489                             strchr(filter, p->status)))
4490                                found++;
4491                }
4492                if (found)
4493                        return;
4494
4495                /* otherwise we will clear the whole queue
4496                 * by copying the empty outq at the end of this
4497                 * function, but first clear the current entries
4498                 * in the queue.
4499                 */
4500                for (i = 0; i < q->nr; i++)
4501                        diff_free_filepair(q->queue[i]);
4502        }
4503        else {
4504                /* Only the matching ones */
4505                for (i = 0; i < q->nr; i++) {
4506                        struct diff_filepair *p = q->queue[i];
4507
4508                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4509                             ((p->score &&
4510                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4511                              (!p->score &&
4512                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4513                            ((p->status != DIFF_STATUS_MODIFIED) &&
4514                             strchr(filter, p->status)))
4515                                diff_q(&outq, p);
4516                        else
4517                                diff_free_filepair(p);
4518                }
4519        }
4520        free(q->queue);
4521        *q = outq;
4522}
4523
4524/* Check whether two filespecs with the same mode and size are identical */
4525static int diff_filespec_is_identical(struct diff_filespec *one,
4526                                      struct diff_filespec *two)
4527{
4528        if (S_ISGITLINK(one->mode))
4529                return 0;
4530        if (diff_populate_filespec(one, 0))
4531                return 0;
4532        if (diff_populate_filespec(two, 0))
4533                return 0;
4534        return !memcmp(one->data, two->data, one->size);
4535}
4536
4537static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4538{
4539        int i;
4540        struct diff_queue_struct *q = &diff_queued_diff;
4541        struct diff_queue_struct outq;
4542        DIFF_QUEUE_CLEAR(&outq);
4543
4544        for (i = 0; i < q->nr; i++) {
4545                struct diff_filepair *p = q->queue[i];
4546
4547                /*
4548                 * 1. Entries that come from stat info dirtiness
4549                 *    always have both sides (iow, not create/delete),
4550                 *    one side of the object name is unknown, with
4551                 *    the same mode and size.  Keep the ones that
4552                 *    do not match these criteria.  They have real
4553                 *    differences.
4554                 *
4555                 * 2. At this point, the file is known to be modified,
4556                 *    with the same mode and size, and the object
4557                 *    name of one side is unknown.  Need to inspect
4558                 *    the identical contents.
4559                 */
4560                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4561                    !DIFF_FILE_VALID(p->two) ||
4562                    (p->one->sha1_valid && p->two->sha1_valid) ||
4563                    (p->one->mode != p->two->mode) ||
4564                    diff_populate_filespec(p->one, 1) ||
4565                    diff_populate_filespec(p->two, 1) ||
4566                    (p->one->size != p->two->size) ||
4567                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4568                        diff_q(&outq, p);
4569                else {
4570                        /*
4571                         * The caller can subtract 1 from skip_stat_unmatch
4572                         * to determine how many paths were dirty only
4573                         * due to stat info mismatch.
4574                         */
4575                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4576                                diffopt->skip_stat_unmatch++;
4577                        diff_free_filepair(p);
4578                }
4579        }
4580        free(q->queue);
4581        *q = outq;
4582}
4583
4584static int diffnamecmp(const void *a_, const void *b_)
4585{
4586        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4587        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4588        const char *name_a, *name_b;
4589
4590        name_a = a->one ? a->one->path : a->two->path;
4591        name_b = b->one ? b->one->path : b->two->path;
4592        return strcmp(name_a, name_b);
4593}
4594
4595void diffcore_fix_diff_index(struct diff_options *options)
4596{
4597        struct diff_queue_struct *q = &diff_queued_diff;
4598        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4599}
4600
4601void diffcore_std(struct diff_options *options)
4602{
4603        if (options->skip_stat_unmatch)
4604                diffcore_skip_stat_unmatch(options);
4605        if (!options->found_follow) {
4606                /* See try_to_follow_renames() in tree-diff.c */
4607                if (options->break_opt != -1)
4608                        diffcore_break(options->break_opt);
4609                if (options->detect_rename)
4610                        diffcore_rename(options);
4611                if (options->break_opt != -1)
4612                        diffcore_merge_broken();
4613        }
4614        if (options->pickaxe)
4615                diffcore_pickaxe(options);
4616        if (options->orderfile)
4617                diffcore_order(options->orderfile);
4618        if (!options->found_follow)
4619                /* See try_to_follow_renames() in tree-diff.c */
4620                diff_resolve_rename_copy();
4621        diffcore_apply_filter(options->filter);
4622
4623        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4624                DIFF_OPT_SET(options, HAS_CHANGES);
4625        else
4626                DIFF_OPT_CLR(options, HAS_CHANGES);
4627
4628        options->found_follow = 0;
4629}
4630
4631int diff_result_code(struct diff_options *opt, int status)
4632{
4633        int result = 0;
4634
4635        diff_warn_rename_limit("diff.renamelimit",
4636                               opt->needed_rename_limit,
4637                               opt->degraded_cc_to_c);
4638        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4639            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4640                return status;
4641        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4642            DIFF_OPT_TST(opt, HAS_CHANGES))
4643                result |= 01;
4644        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4645            DIFF_OPT_TST(opt, CHECK_FAILED))
4646                result |= 02;
4647        return result;
4648}
4649
4650int diff_can_quit_early(struct diff_options *opt)
4651{
4652        return (DIFF_OPT_TST(opt, QUICK) &&
4653                !opt->filter &&
4654                DIFF_OPT_TST(opt, HAS_CHANGES));
4655}
4656
4657/*
4658 * Shall changes to this submodule be ignored?
4659 *
4660 * Submodule changes can be configured to be ignored separately for each path,
4661 * but that configuration can be overridden from the command line.
4662 */
4663static int is_submodule_ignored(const char *path, struct diff_options *options)
4664{
4665        int ignored = 0;
4666        unsigned orig_flags = options->flags;
4667        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4668                set_diffopt_flags_from_submodule_config(options, path);
4669        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4670                ignored = 1;
4671        options->flags = orig_flags;
4672        return ignored;
4673}
4674
4675void diff_addremove(struct diff_options *options,
4676                    int addremove, unsigned mode,
4677                    const unsigned char *sha1,
4678                    const char *concatpath, unsigned dirty_submodule)
4679{
4680        struct diff_filespec *one, *two;
4681
4682        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4683                return;
4684
4685        /* This may look odd, but it is a preparation for
4686         * feeding "there are unchanged files which should
4687         * not produce diffs, but when you are doing copy
4688         * detection you would need them, so here they are"
4689         * entries to the diff-core.  They will be prefixed
4690         * with something like '=' or '*' (I haven't decided
4691         * which but should not make any difference).
4692         * Feeding the same new and old to diff_change()
4693         * also has the same effect.
4694         * Before the final output happens, they are pruned after
4695         * merged into rename/copy pairs as appropriate.
4696         */
4697        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4698                addremove = (addremove == '+' ? '-' :
4699                             addremove == '-' ? '+' : addremove);
4700
4701        if (options->prefix &&
4702            strncmp(concatpath, options->prefix, options->prefix_length))
4703                return;
4704
4705        one = alloc_filespec(concatpath);
4706        two = alloc_filespec(concatpath);
4707
4708        if (addremove != '+')
4709                fill_filespec(one, sha1, mode);
4710        if (addremove != '-') {
4711                fill_filespec(two, sha1, mode);
4712                two->dirty_submodule = dirty_submodule;
4713        }
4714
4715        diff_queue(&diff_queued_diff, one, two);
4716        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4717                DIFF_OPT_SET(options, HAS_CHANGES);
4718}
4719
4720void diff_change(struct diff_options *options,
4721                 unsigned old_mode, unsigned new_mode,
4722                 const unsigned char *old_sha1,
4723                 const unsigned char *new_sha1,
4724                 const char *concatpath,
4725                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4726{
4727        struct diff_filespec *one, *two;
4728
4729        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4730            is_submodule_ignored(concatpath, options))
4731                return;
4732
4733        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4734                unsigned tmp;
4735                const unsigned char *tmp_c;
4736                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4737                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4738                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4739                        new_dirty_submodule = tmp;
4740        }
4741
4742        if (options->prefix &&
4743            strncmp(concatpath, options->prefix, options->prefix_length))
4744                return;
4745
4746        one = alloc_filespec(concatpath);
4747        two = alloc_filespec(concatpath);
4748        fill_filespec(one, old_sha1, old_mode);
4749        fill_filespec(two, new_sha1, new_mode);
4750        one->dirty_submodule = old_dirty_submodule;
4751        two->dirty_submodule = new_dirty_submodule;
4752
4753        diff_queue(&diff_queued_diff, one, two);
4754        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4755                DIFF_OPT_SET(options, HAS_CHANGES);
4756}
4757
4758struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4759{
4760        struct diff_filepair *pair;
4761        struct diff_filespec *one, *two;
4762
4763        if (options->prefix &&
4764            strncmp(path, options->prefix, options->prefix_length))
4765                return NULL;
4766
4767        one = alloc_filespec(path);
4768        two = alloc_filespec(path);
4769        pair = diff_queue(&diff_queued_diff, one, two);
4770        pair->is_unmerged = 1;
4771        return pair;
4772}
4773
4774static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4775                size_t *outsize)
4776{
4777        struct diff_tempfile *temp;
4778        const char *argv[3];
4779        const char **arg = argv;
4780        struct child_process child;
4781        struct strbuf buf = STRBUF_INIT;
4782        int err = 0;
4783
4784        temp = prepare_temp_file(spec->path, spec);
4785        *arg++ = pgm;
4786        *arg++ = temp->name;
4787        *arg = NULL;
4788
4789        memset(&child, 0, sizeof(child));
4790        child.use_shell = 1;
4791        child.argv = argv;
4792        child.out = -1;
4793        if (start_command(&child)) {
4794                remove_tempfile();
4795                return NULL;
4796        }
4797
4798        if (strbuf_read(&buf, child.out, 0) < 0)
4799                err = error("error reading from textconv command '%s'", pgm);
4800        close(child.out);
4801
4802        if (finish_command(&child) || err) {
4803                strbuf_release(&buf);
4804                remove_tempfile();
4805                return NULL;
4806        }
4807        remove_tempfile();
4808
4809        return strbuf_detach(&buf, outsize);
4810}
4811
4812size_t fill_textconv(struct userdiff_driver *driver,
4813                     struct diff_filespec *df,
4814                     char **outbuf)
4815{
4816        size_t size;
4817
4818        if (!driver || !driver->textconv) {
4819                if (!DIFF_FILE_VALID(df)) {
4820                        *outbuf = "";
4821                        return 0;
4822                }
4823                if (diff_populate_filespec(df, 0))
4824                        die("unable to read files to diff");
4825                *outbuf = df->data;
4826                return df->size;
4827        }
4828
4829        if (driver->textconv_cache && df->sha1_valid) {
4830                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4831                                          &size);
4832                if (*outbuf)
4833                        return size;
4834        }
4835
4836        *outbuf = run_textconv(driver->textconv, df, &size);
4837        if (!*outbuf)
4838                die("unable to read files to diff");
4839
4840        if (driver->textconv_cache && df->sha1_valid) {
4841                /* ignore errors, as we might be in a readonly repository */
4842                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4843                                size);
4844                /*
4845                 * we could save up changes and flush them all at the end,
4846                 * but we would need an extra call after all diffing is done.
4847                 * Since generating a cache entry is the slow path anyway,
4848                 * this extra overhead probably isn't a big deal.
4849                 */
4850                notes_cache_write(driver->textconv_cache);
4851        }
4852
4853        return size;
4854}