c78f7d5218def3d0546b636069107bc349d2c884
   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_dirstat_percent_default = 3;
  35static struct diff_options default_diff_options;
  36
  37static char diff_colors[][COLOR_MAXLEN] = {
  38        GIT_COLOR_RESET,
  39        GIT_COLOR_NORMAL,       /* PLAIN */
  40        GIT_COLOR_BOLD,         /* METAINFO */
  41        GIT_COLOR_CYAN,         /* FRAGINFO */
  42        GIT_COLOR_RED,          /* OLD */
  43        GIT_COLOR_GREEN,        /* NEW */
  44        GIT_COLOR_YELLOW,       /* COMMIT */
  45        GIT_COLOR_BG_RED,       /* WHITESPACE */
  46        GIT_COLOR_NORMAL,       /* FUNCINFO */
  47};
  48
  49static int parse_diff_color_slot(const char *var, int ofs)
  50{
  51        if (!strcasecmp(var+ofs, "plain"))
  52                return DIFF_PLAIN;
  53        if (!strcasecmp(var+ofs, "meta"))
  54                return DIFF_METAINFO;
  55        if (!strcasecmp(var+ofs, "frag"))
  56                return DIFF_FRAGINFO;
  57        if (!strcasecmp(var+ofs, "old"))
  58                return DIFF_FILE_OLD;
  59        if (!strcasecmp(var+ofs, "new"))
  60                return DIFF_FILE_NEW;
  61        if (!strcasecmp(var+ofs, "commit"))
  62                return DIFF_COMMIT;
  63        if (!strcasecmp(var+ofs, "whitespace"))
  64                return DIFF_WHITESPACE;
  65        if (!strcasecmp(var+ofs, "func"))
  66                return DIFF_FUNCINFO;
  67        return -1;
  68}
  69
  70static int parse_dirstat_params(struct diff_options *options, const char *params)
  71{
  72        const char *p = params;
  73        while (*p) {
  74                if (!prefixcmp(p, "changes")) {
  75                        p += 7;
  76                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  77                } else if (!prefixcmp(p, "files")) {
  78                        p += 5;
  79                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  80                } else if (!prefixcmp(p, "noncumulative")) {
  81                        p += 13;
  82                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  83                } else if (!prefixcmp(p, "cumulative")) {
  84                        p += 10;
  85                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  86                } else if (isdigit(*p)) {
  87                        char *end;
  88                        options->dirstat_percent = strtoul(p, &end, 10);
  89                        p = end;
  90                } else
  91                        return error("Unknown --dirstat parameter '%s'", p);
  92
  93                if (*p) {
  94                        /* more parameters, swallow separator */
  95                        if (*p != ',')
  96                                return error("Missing comma separator at char "
  97                                        "%"PRIuMAX" of '%s'",
  98                                        (uintmax_t) (p - params), params);
  99                        p++;
 100                }
 101        }
 102        return 0;
 103}
 104
 105static int git_config_rename(const char *var, const char *value)
 106{
 107        if (!value)
 108                return DIFF_DETECT_RENAME;
 109        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 110                return  DIFF_DETECT_COPY;
 111        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 112}
 113
 114/*
 115 * These are to give UI layer defaults.
 116 * The core-level commands such as git-diff-files should
 117 * never be affected by the setting of diff.renames
 118 * the user happens to have in the configuration file.
 119 */
 120int git_diff_ui_config(const char *var, const char *value, void *cb)
 121{
 122        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 123                diff_use_color_default = git_config_colorbool(var, value, -1);
 124                return 0;
 125        }
 126        if (!strcmp(var, "diff.renames")) {
 127                diff_detect_rename_default = git_config_rename(var, value);
 128                return 0;
 129        }
 130        if (!strcmp(var, "diff.autorefreshindex")) {
 131                diff_auto_refresh_index = git_config_bool(var, value);
 132                return 0;
 133        }
 134        if (!strcmp(var, "diff.mnemonicprefix")) {
 135                diff_mnemonic_prefix = git_config_bool(var, value);
 136                return 0;
 137        }
 138        if (!strcmp(var, "diff.noprefix")) {
 139                diff_no_prefix = git_config_bool(var, value);
 140                return 0;
 141        }
 142        if (!strcmp(var, "diff.external"))
 143                return git_config_string(&external_diff_cmd_cfg, var, value);
 144        if (!strcmp(var, "diff.wordregex"))
 145                return git_config_string(&diff_word_regex_cfg, var, value);
 146
 147        if (!strcmp(var, "diff.ignoresubmodules"))
 148                handle_ignore_submodules_arg(&default_diff_options, value);
 149
 150        return git_diff_basic_config(var, value, cb);
 151}
 152
 153int git_diff_basic_config(const char *var, const char *value, void *cb)
 154{
 155        if (!strcmp(var, "diff.renamelimit")) {
 156                diff_rename_limit_default = git_config_int(var, value);
 157                return 0;
 158        }
 159
 160        switch (userdiff_config(var, value)) {
 161                case 0: break;
 162                case -1: return -1;
 163                default: return 0;
 164        }
 165
 166        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 167                int slot = parse_diff_color_slot(var, 11);
 168                if (slot < 0)
 169                        return 0;
 170                if (!value)
 171                        return config_error_nonbool(var);
 172                color_parse(value, var, diff_colors[slot]);
 173                return 0;
 174        }
 175
 176        /* like GNU diff's --suppress-blank-empty option  */
 177        if (!strcmp(var, "diff.suppressblankempty") ||
 178                        /* for backwards compatibility */
 179                        !strcmp(var, "diff.suppress-blank-empty")) {
 180                diff_suppress_blank_empty = git_config_bool(var, value);
 181                return 0;
 182        }
 183
 184        if (!strcmp(var, "diff.dirstat")) {
 185                default_diff_options.dirstat_percent = diff_dirstat_percent_default;
 186                (void) parse_dirstat_params(&default_diff_options, value);
 187                diff_dirstat_percent_default = default_diff_options.dirstat_percent;
 188                return 0;
 189        }
 190
 191        if (!prefixcmp(var, "submodule."))
 192                return parse_submodule_config_option(var, value);
 193
 194        return git_color_default_config(var, value, cb);
 195}
 196
 197static char *quote_two(const char *one, const char *two)
 198{
 199        int need_one = quote_c_style(one, NULL, NULL, 1);
 200        int need_two = quote_c_style(two, NULL, NULL, 1);
 201        struct strbuf res = STRBUF_INIT;
 202
 203        if (need_one + need_two) {
 204                strbuf_addch(&res, '"');
 205                quote_c_style(one, &res, NULL, 1);
 206                quote_c_style(two, &res, NULL, 1);
 207                strbuf_addch(&res, '"');
 208        } else {
 209                strbuf_addstr(&res, one);
 210                strbuf_addstr(&res, two);
 211        }
 212        return strbuf_detach(&res, NULL);
 213}
 214
 215static const char *external_diff(void)
 216{
 217        static const char *external_diff_cmd = NULL;
 218        static int done_preparing = 0;
 219
 220        if (done_preparing)
 221                return external_diff_cmd;
 222        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 223        if (!external_diff_cmd)
 224                external_diff_cmd = external_diff_cmd_cfg;
 225        done_preparing = 1;
 226        return external_diff_cmd;
 227}
 228
 229static struct diff_tempfile {
 230        const char *name; /* filename external diff should read from */
 231        char hex[41];
 232        char mode[10];
 233        char tmp_path[PATH_MAX];
 234} diff_temp[2];
 235
 236typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 237
 238struct emit_callback {
 239        int color_diff;
 240        unsigned ws_rule;
 241        int blank_at_eof_in_preimage;
 242        int blank_at_eof_in_postimage;
 243        int lno_in_preimage;
 244        int lno_in_postimage;
 245        sane_truncate_fn truncate;
 246        const char **label_path;
 247        struct diff_words_data *diff_words;
 248        struct diff_options *opt;
 249        int *found_changesp;
 250        struct strbuf *header;
 251};
 252
 253static int count_lines(const char *data, int size)
 254{
 255        int count, ch, completely_empty = 1, nl_just_seen = 0;
 256        count = 0;
 257        while (0 < size--) {
 258                ch = *data++;
 259                if (ch == '\n') {
 260                        count++;
 261                        nl_just_seen = 1;
 262                        completely_empty = 0;
 263                }
 264                else {
 265                        nl_just_seen = 0;
 266                        completely_empty = 0;
 267                }
 268        }
 269        if (completely_empty)
 270                return 0;
 271        if (!nl_just_seen)
 272                count++; /* no trailing newline */
 273        return count;
 274}
 275
 276static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 277{
 278        if (!DIFF_FILE_VALID(one)) {
 279                mf->ptr = (char *)""; /* does not matter */
 280                mf->size = 0;
 281                return 0;
 282        }
 283        else if (diff_populate_filespec(one, 0))
 284                return -1;
 285
 286        mf->ptr = one->data;
 287        mf->size = one->size;
 288        return 0;
 289}
 290
 291/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 292static unsigned long diff_filespec_size(struct diff_filespec *one)
 293{
 294        if (!DIFF_FILE_VALID(one))
 295                return 0;
 296        diff_populate_filespec(one, 1);
 297        return one->size;
 298}
 299
 300static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 301{
 302        char *ptr = mf->ptr;
 303        long size = mf->size;
 304        int cnt = 0;
 305
 306        if (!size)
 307                return cnt;
 308        ptr += size - 1; /* pointing at the very end */
 309        if (*ptr != '\n')
 310                ; /* incomplete line */
 311        else
 312                ptr--; /* skip the last LF */
 313        while (mf->ptr < ptr) {
 314                char *prev_eol;
 315                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 316                        if (*prev_eol == '\n')
 317                                break;
 318                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 319                        break;
 320                cnt++;
 321                ptr = prev_eol - 1;
 322        }
 323        return cnt;
 324}
 325
 326static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 327                               struct emit_callback *ecbdata)
 328{
 329        int l1, l2, at;
 330        unsigned ws_rule = ecbdata->ws_rule;
 331        l1 = count_trailing_blank(mf1, ws_rule);
 332        l2 = count_trailing_blank(mf2, ws_rule);
 333        if (l2 <= l1) {
 334                ecbdata->blank_at_eof_in_preimage = 0;
 335                ecbdata->blank_at_eof_in_postimage = 0;
 336                return;
 337        }
 338        at = count_lines(mf1->ptr, mf1->size);
 339        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 340
 341        at = count_lines(mf2->ptr, mf2->size);
 342        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 343}
 344
 345static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 346                        int first, const char *line, int len)
 347{
 348        int has_trailing_newline, has_trailing_carriage_return;
 349        int nofirst;
 350        FILE *file = o->file;
 351
 352        if (o->output_prefix) {
 353                struct strbuf *msg = NULL;
 354                msg = o->output_prefix(o, o->output_prefix_data);
 355                assert(msg);
 356                fwrite(msg->buf, msg->len, 1, file);
 357        }
 358
 359        if (len == 0) {
 360                has_trailing_newline = (first == '\n');
 361                has_trailing_carriage_return = (!has_trailing_newline &&
 362                                                (first == '\r'));
 363                nofirst = has_trailing_newline || has_trailing_carriage_return;
 364        } else {
 365                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 366                if (has_trailing_newline)
 367                        len--;
 368                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 369                if (has_trailing_carriage_return)
 370                        len--;
 371                nofirst = 0;
 372        }
 373
 374        if (len || !nofirst) {
 375                fputs(set, file);
 376                if (!nofirst)
 377                        fputc(first, file);
 378                fwrite(line, len, 1, file);
 379                fputs(reset, file);
 380        }
 381        if (has_trailing_carriage_return)
 382                fputc('\r', file);
 383        if (has_trailing_newline)
 384                fputc('\n', file);
 385}
 386
 387static void emit_line(struct diff_options *o, const char *set, const char *reset,
 388                      const char *line, int len)
 389{
 390        emit_line_0(o, set, reset, line[0], line+1, len-1);
 391}
 392
 393static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 394{
 395        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 396              ecbdata->blank_at_eof_in_preimage &&
 397              ecbdata->blank_at_eof_in_postimage &&
 398              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 399              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 400                return 0;
 401        return ws_blank_line(line, len, ecbdata->ws_rule);
 402}
 403
 404static void emit_add_line(const char *reset,
 405                          struct emit_callback *ecbdata,
 406                          const char *line, int len)
 407{
 408        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 409        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 410
 411        if (!*ws)
 412                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 413        else if (new_blank_line_at_eof(ecbdata, line, len))
 414                /* Blank line at EOF - paint '+' as well */
 415                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 416        else {
 417                /* Emit just the prefix, then the rest. */
 418                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 419                ws_check_emit(line, len, ecbdata->ws_rule,
 420                              ecbdata->opt->file, set, reset, ws);
 421        }
 422}
 423
 424static void emit_hunk_header(struct emit_callback *ecbdata,
 425                             const char *line, int len)
 426{
 427        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 428        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 429        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 430        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 431        static const char atat[2] = { '@', '@' };
 432        const char *cp, *ep;
 433        struct strbuf msgbuf = STRBUF_INIT;
 434        int org_len = len;
 435        int i = 1;
 436
 437        /*
 438         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 439         * it always is at least 10 bytes long.
 440         */
 441        if (len < 10 ||
 442            memcmp(line, atat, 2) ||
 443            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 444                emit_line(ecbdata->opt, plain, reset, line, len);
 445                return;
 446        }
 447        ep += 2; /* skip over @@ */
 448
 449        /* The hunk header in fraginfo color */
 450        strbuf_add(&msgbuf, frag, strlen(frag));
 451        strbuf_add(&msgbuf, line, ep - line);
 452        strbuf_add(&msgbuf, reset, strlen(reset));
 453
 454        /*
 455         * trailing "\r\n"
 456         */
 457        for ( ; i < 3; i++)
 458                if (line[len - i] == '\r' || line[len - i] == '\n')
 459                        len--;
 460
 461        /* blank before the func header */
 462        for (cp = ep; ep - line < len; ep++)
 463                if (*ep != ' ' && *ep != '\t')
 464                        break;
 465        if (ep != cp) {
 466                strbuf_add(&msgbuf, plain, strlen(plain));
 467                strbuf_add(&msgbuf, cp, ep - cp);
 468                strbuf_add(&msgbuf, reset, strlen(reset));
 469        }
 470
 471        if (ep < line + len) {
 472                strbuf_add(&msgbuf, func, strlen(func));
 473                strbuf_add(&msgbuf, ep, line + len - ep);
 474                strbuf_add(&msgbuf, reset, strlen(reset));
 475        }
 476
 477        strbuf_add(&msgbuf, line + len, org_len - len);
 478        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 479        strbuf_release(&msgbuf);
 480}
 481
 482static struct diff_tempfile *claim_diff_tempfile(void) {
 483        int i;
 484        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 485                if (!diff_temp[i].name)
 486                        return diff_temp + i;
 487        die("BUG: diff is failing to clean up its tempfiles");
 488}
 489
 490static int remove_tempfile_installed;
 491
 492static void remove_tempfile(void)
 493{
 494        int i;
 495        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 496                if (diff_temp[i].name == diff_temp[i].tmp_path)
 497                        unlink_or_warn(diff_temp[i].name);
 498                diff_temp[i].name = NULL;
 499        }
 500}
 501
 502static void remove_tempfile_on_signal(int signo)
 503{
 504        remove_tempfile();
 505        sigchain_pop(signo);
 506        raise(signo);
 507}
 508
 509static void print_line_count(FILE *file, int count)
 510{
 511        switch (count) {
 512        case 0:
 513                fprintf(file, "0,0");
 514                break;
 515        case 1:
 516                fprintf(file, "1");
 517                break;
 518        default:
 519                fprintf(file, "1,%d", count);
 520                break;
 521        }
 522}
 523
 524static void emit_rewrite_lines(struct emit_callback *ecb,
 525                               int prefix, const char *data, int size)
 526{
 527        const char *endp = NULL;
 528        static const char *nneof = " No newline at end of file\n";
 529        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 530        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 531
 532        while (0 < size) {
 533                int len;
 534
 535                endp = memchr(data, '\n', size);
 536                len = endp ? (endp - data + 1) : size;
 537                if (prefix != '+') {
 538                        ecb->lno_in_preimage++;
 539                        emit_line_0(ecb->opt, old, reset, '-',
 540                                    data, len);
 541                } else {
 542                        ecb->lno_in_postimage++;
 543                        emit_add_line(reset, ecb, data, len);
 544                }
 545                size -= len;
 546                data += len;
 547        }
 548        if (!endp) {
 549                const char *plain = diff_get_color(ecb->color_diff,
 550                                                   DIFF_PLAIN);
 551                emit_line_0(ecb->opt, plain, reset, '\\',
 552                            nneof, strlen(nneof));
 553        }
 554}
 555
 556static void emit_rewrite_diff(const char *name_a,
 557                              const char *name_b,
 558                              struct diff_filespec *one,
 559                              struct diff_filespec *two,
 560                              struct userdiff_driver *textconv_one,
 561                              struct userdiff_driver *textconv_two,
 562                              struct diff_options *o)
 563{
 564        int lc_a, lc_b;
 565        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 566        const char *name_a_tab, *name_b_tab;
 567        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 568        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 569        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 570        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 571        const char *a_prefix, *b_prefix;
 572        char *data_one, *data_two;
 573        size_t size_one, size_two;
 574        struct emit_callback ecbdata;
 575        char *line_prefix = "";
 576        struct strbuf *msgbuf;
 577
 578        if (o && o->output_prefix) {
 579                msgbuf = o->output_prefix(o, o->output_prefix_data);
 580                line_prefix = msgbuf->buf;
 581        }
 582
 583        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 584                a_prefix = o->b_prefix;
 585                b_prefix = o->a_prefix;
 586        } else {
 587                a_prefix = o->a_prefix;
 588                b_prefix = o->b_prefix;
 589        }
 590
 591        name_a += (*name_a == '/');
 592        name_b += (*name_b == '/');
 593        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 594        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 595
 596        strbuf_reset(&a_name);
 597        strbuf_reset(&b_name);
 598        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 599        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 600
 601        size_one = fill_textconv(textconv_one, one, &data_one);
 602        size_two = fill_textconv(textconv_two, two, &data_two);
 603
 604        memset(&ecbdata, 0, sizeof(ecbdata));
 605        ecbdata.color_diff = color_diff;
 606        ecbdata.found_changesp = &o->found_changes;
 607        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 608        ecbdata.opt = o;
 609        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 610                mmfile_t mf1, mf2;
 611                mf1.ptr = (char *)data_one;
 612                mf2.ptr = (char *)data_two;
 613                mf1.size = size_one;
 614                mf2.size = size_two;
 615                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 616        }
 617        ecbdata.lno_in_preimage = 1;
 618        ecbdata.lno_in_postimage = 1;
 619
 620        lc_a = count_lines(data_one, size_one);
 621        lc_b = count_lines(data_two, size_two);
 622        fprintf(o->file,
 623                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 624                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 625                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 626                line_prefix, fraginfo);
 627        if (!o->irreversible_delete)
 628                print_line_count(o->file, lc_a);
 629        else
 630                fprintf(o->file, "?,?");
 631        fprintf(o->file, " +");
 632        print_line_count(o->file, lc_b);
 633        fprintf(o->file, " @@%s\n", reset);
 634        if (lc_a && !o->irreversible_delete)
 635                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 636        if (lc_b)
 637                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 638        if (textconv_one)
 639                free((char *)data_one);
 640        if (textconv_two)
 641                free((char *)data_two);
 642}
 643
 644struct diff_words_buffer {
 645        mmfile_t text;
 646        long alloc;
 647        struct diff_words_orig {
 648                const char *begin, *end;
 649        } *orig;
 650        int orig_nr, orig_alloc;
 651};
 652
 653static void diff_words_append(char *line, unsigned long len,
 654                struct diff_words_buffer *buffer)
 655{
 656        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 657        line++;
 658        len--;
 659        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 660        buffer->text.size += len;
 661        buffer->text.ptr[buffer->text.size] = '\0';
 662}
 663
 664struct diff_words_style_elem {
 665        const char *prefix;
 666        const char *suffix;
 667        const char *color; /* NULL; filled in by the setup code if
 668                            * color is enabled */
 669};
 670
 671struct diff_words_style {
 672        enum diff_words_type type;
 673        struct diff_words_style_elem new, old, ctx;
 674        const char *newline;
 675};
 676
 677static struct diff_words_style diff_words_styles[] = {
 678        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 679        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 680        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 681};
 682
 683struct diff_words_data {
 684        struct diff_words_buffer minus, plus;
 685        const char *current_plus;
 686        int last_minus;
 687        struct diff_options *opt;
 688        regex_t *word_regex;
 689        enum diff_words_type type;
 690        struct diff_words_style *style;
 691};
 692
 693static int fn_out_diff_words_write_helper(FILE *fp,
 694                                          struct diff_words_style_elem *st_el,
 695                                          const char *newline,
 696                                          size_t count, const char *buf,
 697                                          const char *line_prefix)
 698{
 699        int print = 0;
 700
 701        while (count) {
 702                char *p = memchr(buf, '\n', count);
 703                if (print)
 704                        fputs(line_prefix, fp);
 705                if (p != buf) {
 706                        if (st_el->color && fputs(st_el->color, fp) < 0)
 707                                return -1;
 708                        if (fputs(st_el->prefix, fp) < 0 ||
 709                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 710                            fputs(st_el->suffix, fp) < 0)
 711                                return -1;
 712                        if (st_el->color && *st_el->color
 713                            && fputs(GIT_COLOR_RESET, fp) < 0)
 714                                return -1;
 715                }
 716                if (!p)
 717                        return 0;
 718                if (fputs(newline, fp) < 0)
 719                        return -1;
 720                count -= p + 1 - buf;
 721                buf = p + 1;
 722                print = 1;
 723        }
 724        return 0;
 725}
 726
 727/*
 728 * '--color-words' algorithm can be described as:
 729 *
 730 *   1. collect a the minus/plus lines of a diff hunk, divided into
 731 *      minus-lines and plus-lines;
 732 *
 733 *   2. break both minus-lines and plus-lines into words and
 734 *      place them into two mmfile_t with one word for each line;
 735 *
 736 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 737 *
 738 * And for the common parts of the both file, we output the plus side text.
 739 * diff_words->current_plus is used to trace the current position of the plus file
 740 * which printed. diff_words->last_minus is used to trace the last minus word
 741 * printed.
 742 *
 743 * For '--graph' to work with '--color-words', we need to output the graph prefix
 744 * on each line of color words output. Generally, there are two conditions on
 745 * which we should output the prefix.
 746 *
 747 *   1. diff_words->last_minus == 0 &&
 748 *      diff_words->current_plus == diff_words->plus.text.ptr
 749 *
 750 *      that is: the plus text must start as a new line, and if there is no minus
 751 *      word printed, a graph prefix must be printed.
 752 *
 753 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 754 *      *(diff_words->current_plus - 1) == '\n'
 755 *
 756 *      that is: a graph prefix must be printed following a '\n'
 757 */
 758static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 759{
 760        if ((diff_words->last_minus == 0 &&
 761                diff_words->current_plus == diff_words->plus.text.ptr) ||
 762                (diff_words->current_plus > diff_words->plus.text.ptr &&
 763                *(diff_words->current_plus - 1) == '\n')) {
 764                return 1;
 765        } else {
 766                return 0;
 767        }
 768}
 769
 770static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 771{
 772        struct diff_words_data *diff_words = priv;
 773        struct diff_words_style *style = diff_words->style;
 774        int minus_first, minus_len, plus_first, plus_len;
 775        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 776        struct diff_options *opt = diff_words->opt;
 777        struct strbuf *msgbuf;
 778        char *line_prefix = "";
 779
 780        if (line[0] != '@' || parse_hunk_header(line, len,
 781                        &minus_first, &minus_len, &plus_first, &plus_len))
 782                return;
 783
 784        assert(opt);
 785        if (opt->output_prefix) {
 786                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 787                line_prefix = msgbuf->buf;
 788        }
 789
 790        /* POSIX requires that first be decremented by one if len == 0... */
 791        if (minus_len) {
 792                minus_begin = diff_words->minus.orig[minus_first].begin;
 793                minus_end =
 794                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 795        } else
 796                minus_begin = minus_end =
 797                        diff_words->minus.orig[minus_first].end;
 798
 799        if (plus_len) {
 800                plus_begin = diff_words->plus.orig[plus_first].begin;
 801                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 802        } else
 803                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 804
 805        if (color_words_output_graph_prefix(diff_words)) {
 806                fputs(line_prefix, diff_words->opt->file);
 807        }
 808        if (diff_words->current_plus != plus_begin) {
 809                fn_out_diff_words_write_helper(diff_words->opt->file,
 810                                &style->ctx, style->newline,
 811                                plus_begin - diff_words->current_plus,
 812                                diff_words->current_plus, line_prefix);
 813                if (*(plus_begin - 1) == '\n')
 814                        fputs(line_prefix, diff_words->opt->file);
 815        }
 816        if (minus_begin != minus_end) {
 817                fn_out_diff_words_write_helper(diff_words->opt->file,
 818                                &style->old, style->newline,
 819                                minus_end - minus_begin, minus_begin,
 820                                line_prefix);
 821        }
 822        if (plus_begin != plus_end) {
 823                fn_out_diff_words_write_helper(diff_words->opt->file,
 824                                &style->new, style->newline,
 825                                plus_end - plus_begin, plus_begin,
 826                                line_prefix);
 827        }
 828
 829        diff_words->current_plus = plus_end;
 830        diff_words->last_minus = minus_first;
 831}
 832
 833/* This function starts looking at *begin, and returns 0 iff a word was found. */
 834static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 835                int *begin, int *end)
 836{
 837        if (word_regex && *begin < buffer->size) {
 838                regmatch_t match[1];
 839                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 840                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 841                                        '\n', match[0].rm_eo - match[0].rm_so);
 842                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 843                        *begin += match[0].rm_so;
 844                        return *begin >= *end;
 845                }
 846                return -1;
 847        }
 848
 849        /* find the next word */
 850        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 851                (*begin)++;
 852        if (*begin >= buffer->size)
 853                return -1;
 854
 855        /* find the end of the word */
 856        *end = *begin + 1;
 857        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 858                (*end)++;
 859
 860        return 0;
 861}
 862
 863/*
 864 * This function splits the words in buffer->text, stores the list with
 865 * newline separator into out, and saves the offsets of the original words
 866 * in buffer->orig.
 867 */
 868static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 869                regex_t *word_regex)
 870{
 871        int i, j;
 872        long alloc = 0;
 873
 874        out->size = 0;
 875        out->ptr = NULL;
 876
 877        /* fake an empty "0th" word */
 878        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 879        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 880        buffer->orig_nr = 1;
 881
 882        for (i = 0; i < buffer->text.size; i++) {
 883                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 884                        return;
 885
 886                /* store original boundaries */
 887                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 888                                buffer->orig_alloc);
 889                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 890                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 891                buffer->orig_nr++;
 892
 893                /* store one word */
 894                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 895                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 896                out->ptr[out->size + j - i] = '\n';
 897                out->size += j - i + 1;
 898
 899                i = j - 1;
 900        }
 901}
 902
 903/* this executes the word diff on the accumulated buffers */
 904static void diff_words_show(struct diff_words_data *diff_words)
 905{
 906        xpparam_t xpp;
 907        xdemitconf_t xecfg;
 908        mmfile_t minus, plus;
 909        struct diff_words_style *style = diff_words->style;
 910
 911        struct diff_options *opt = diff_words->opt;
 912        struct strbuf *msgbuf;
 913        char *line_prefix = "";
 914
 915        assert(opt);
 916        if (opt->output_prefix) {
 917                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 918                line_prefix = msgbuf->buf;
 919        }
 920
 921        /* special case: only removal */
 922        if (!diff_words->plus.text.size) {
 923                fputs(line_prefix, diff_words->opt->file);
 924                fn_out_diff_words_write_helper(diff_words->opt->file,
 925                        &style->old, style->newline,
 926                        diff_words->minus.text.size,
 927                        diff_words->minus.text.ptr, line_prefix);
 928                diff_words->minus.text.size = 0;
 929                return;
 930        }
 931
 932        diff_words->current_plus = diff_words->plus.text.ptr;
 933        diff_words->last_minus = 0;
 934
 935        memset(&xpp, 0, sizeof(xpp));
 936        memset(&xecfg, 0, sizeof(xecfg));
 937        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 938        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 939        xpp.flags = 0;
 940        /* as only the hunk header will be parsed, we need a 0-context */
 941        xecfg.ctxlen = 0;
 942        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 943                      &xpp, &xecfg);
 944        free(minus.ptr);
 945        free(plus.ptr);
 946        if (diff_words->current_plus != diff_words->plus.text.ptr +
 947                        diff_words->plus.text.size) {
 948                if (color_words_output_graph_prefix(diff_words))
 949                        fputs(line_prefix, diff_words->opt->file);
 950                fn_out_diff_words_write_helper(diff_words->opt->file,
 951                        &style->ctx, style->newline,
 952                        diff_words->plus.text.ptr + diff_words->plus.text.size
 953                        - diff_words->current_plus, diff_words->current_plus,
 954                        line_prefix);
 955        }
 956        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 957}
 958
 959/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 960static void diff_words_flush(struct emit_callback *ecbdata)
 961{
 962        if (ecbdata->diff_words->minus.text.size ||
 963            ecbdata->diff_words->plus.text.size)
 964                diff_words_show(ecbdata->diff_words);
 965}
 966
 967static void free_diff_words_data(struct emit_callback *ecbdata)
 968{
 969        if (ecbdata->diff_words) {
 970                diff_words_flush(ecbdata);
 971                free (ecbdata->diff_words->minus.text.ptr);
 972                free (ecbdata->diff_words->minus.orig);
 973                free (ecbdata->diff_words->plus.text.ptr);
 974                free (ecbdata->diff_words->plus.orig);
 975                if (ecbdata->diff_words->word_regex) {
 976                        regfree(ecbdata->diff_words->word_regex);
 977                        free(ecbdata->diff_words->word_regex);
 978                }
 979                free(ecbdata->diff_words);
 980                ecbdata->diff_words = NULL;
 981        }
 982}
 983
 984const char *diff_get_color(int diff_use_color, enum color_diff ix)
 985{
 986        if (diff_use_color)
 987                return diff_colors[ix];
 988        return "";
 989}
 990
 991static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 992{
 993        const char *cp;
 994        unsigned long allot;
 995        size_t l = len;
 996
 997        if (ecb->truncate)
 998                return ecb->truncate(line, len);
 999        cp = line;
1000        allot = l;
1001        while (0 < l) {
1002                (void) utf8_width(&cp, &l);
1003                if (!cp)
1004                        break; /* truncated in the middle? */
1005        }
1006        return allot - l;
1007}
1008
1009static void find_lno(const char *line, struct emit_callback *ecbdata)
1010{
1011        const char *p;
1012        ecbdata->lno_in_preimage = 0;
1013        ecbdata->lno_in_postimage = 0;
1014        p = strchr(line, '-');
1015        if (!p)
1016                return; /* cannot happen */
1017        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1018        p = strchr(p, '+');
1019        if (!p)
1020                return; /* cannot happen */
1021        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1022}
1023
1024static void fn_out_consume(void *priv, char *line, unsigned long len)
1025{
1026        struct emit_callback *ecbdata = priv;
1027        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1028        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1029        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1030        struct diff_options *o = ecbdata->opt;
1031        char *line_prefix = "";
1032        struct strbuf *msgbuf;
1033
1034        if (o && o->output_prefix) {
1035                msgbuf = o->output_prefix(o, o->output_prefix_data);
1036                line_prefix = msgbuf->buf;
1037        }
1038
1039        if (ecbdata->header) {
1040                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1041                strbuf_reset(ecbdata->header);
1042                ecbdata->header = NULL;
1043        }
1044        *(ecbdata->found_changesp) = 1;
1045
1046        if (ecbdata->label_path[0]) {
1047                const char *name_a_tab, *name_b_tab;
1048
1049                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1050                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1051
1052                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1053                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1054                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1055                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1056                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1057        }
1058
1059        if (diff_suppress_blank_empty
1060            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1061                line[0] = '\n';
1062                len = 1;
1063        }
1064
1065        if (line[0] == '@') {
1066                if (ecbdata->diff_words)
1067                        diff_words_flush(ecbdata);
1068                len = sane_truncate_line(ecbdata, line, len);
1069                find_lno(line, ecbdata);
1070                emit_hunk_header(ecbdata, line, len);
1071                if (line[len-1] != '\n')
1072                        putc('\n', ecbdata->opt->file);
1073                return;
1074        }
1075
1076        if (len < 1) {
1077                emit_line(ecbdata->opt, reset, reset, line, len);
1078                if (ecbdata->diff_words
1079                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1080                        fputs("~\n", ecbdata->opt->file);
1081                return;
1082        }
1083
1084        if (ecbdata->diff_words) {
1085                if (line[0] == '-') {
1086                        diff_words_append(line, len,
1087                                          &ecbdata->diff_words->minus);
1088                        return;
1089                } else if (line[0] == '+') {
1090                        diff_words_append(line, len,
1091                                          &ecbdata->diff_words->plus);
1092                        return;
1093                }
1094                diff_words_flush(ecbdata);
1095                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1096                        emit_line(ecbdata->opt, plain, reset, line, len);
1097                        fputs("~\n", ecbdata->opt->file);
1098                } else {
1099                        /* don't print the prefix character */
1100                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1101                }
1102                return;
1103        }
1104
1105        if (line[0] != '+') {
1106                const char *color =
1107                        diff_get_color(ecbdata->color_diff,
1108                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1109                ecbdata->lno_in_preimage++;
1110                if (line[0] == ' ')
1111                        ecbdata->lno_in_postimage++;
1112                emit_line(ecbdata->opt, color, reset, line, len);
1113        } else {
1114                ecbdata->lno_in_postimage++;
1115                emit_add_line(reset, ecbdata, line + 1, len - 1);
1116        }
1117}
1118
1119static char *pprint_rename(const char *a, const char *b)
1120{
1121        const char *old = a;
1122        const char *new = b;
1123        struct strbuf name = STRBUF_INIT;
1124        int pfx_length, sfx_length;
1125        int len_a = strlen(a);
1126        int len_b = strlen(b);
1127        int a_midlen, b_midlen;
1128        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1129        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1130
1131        if (qlen_a || qlen_b) {
1132                quote_c_style(a, &name, NULL, 0);
1133                strbuf_addstr(&name, " => ");
1134                quote_c_style(b, &name, NULL, 0);
1135                return strbuf_detach(&name, NULL);
1136        }
1137
1138        /* Find common prefix */
1139        pfx_length = 0;
1140        while (*old && *new && *old == *new) {
1141                if (*old == '/')
1142                        pfx_length = old - a + 1;
1143                old++;
1144                new++;
1145        }
1146
1147        /* Find common suffix */
1148        old = a + len_a;
1149        new = b + len_b;
1150        sfx_length = 0;
1151        while (a <= old && b <= new && *old == *new) {
1152                if (*old == '/')
1153                        sfx_length = len_a - (old - a);
1154                old--;
1155                new--;
1156        }
1157
1158        /*
1159         * pfx{mid-a => mid-b}sfx
1160         * {pfx-a => pfx-b}sfx
1161         * pfx{sfx-a => sfx-b}
1162         * name-a => name-b
1163         */
1164        a_midlen = len_a - pfx_length - sfx_length;
1165        b_midlen = len_b - pfx_length - sfx_length;
1166        if (a_midlen < 0)
1167                a_midlen = 0;
1168        if (b_midlen < 0)
1169                b_midlen = 0;
1170
1171        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1172        if (pfx_length + sfx_length) {
1173                strbuf_add(&name, a, pfx_length);
1174                strbuf_addch(&name, '{');
1175        }
1176        strbuf_add(&name, a + pfx_length, a_midlen);
1177        strbuf_addstr(&name, " => ");
1178        strbuf_add(&name, b + pfx_length, b_midlen);
1179        if (pfx_length + sfx_length) {
1180                strbuf_addch(&name, '}');
1181                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1182        }
1183        return strbuf_detach(&name, NULL);
1184}
1185
1186struct diffstat_t {
1187        int nr;
1188        int alloc;
1189        struct diffstat_file {
1190                char *from_name;
1191                char *name;
1192                char *print_name;
1193                unsigned is_unmerged:1;
1194                unsigned is_binary:1;
1195                unsigned is_renamed:1;
1196                uintmax_t added, deleted;
1197        } **files;
1198};
1199
1200static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1201                                          const char *name_a,
1202                                          const char *name_b)
1203{
1204        struct diffstat_file *x;
1205        x = xcalloc(sizeof (*x), 1);
1206        if (diffstat->nr == diffstat->alloc) {
1207                diffstat->alloc = alloc_nr(diffstat->alloc);
1208                diffstat->files = xrealloc(diffstat->files,
1209                                diffstat->alloc * sizeof(x));
1210        }
1211        diffstat->files[diffstat->nr++] = x;
1212        if (name_b) {
1213                x->from_name = xstrdup(name_a);
1214                x->name = xstrdup(name_b);
1215                x->is_renamed = 1;
1216        }
1217        else {
1218                x->from_name = NULL;
1219                x->name = xstrdup(name_a);
1220        }
1221        return x;
1222}
1223
1224static void diffstat_consume(void *priv, char *line, unsigned long len)
1225{
1226        struct diffstat_t *diffstat = priv;
1227        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1228
1229        if (line[0] == '+')
1230                x->added++;
1231        else if (line[0] == '-')
1232                x->deleted++;
1233}
1234
1235const char mime_boundary_leader[] = "------------";
1236
1237static int scale_linear(int it, int width, int max_change)
1238{
1239        /*
1240         * make sure that at least one '-' is printed if there were deletions,
1241         * and likewise for '+'.
1242         */
1243        if (max_change < 2)
1244                return it;
1245        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1246}
1247
1248static void show_name(FILE *file,
1249                      const char *prefix, const char *name, int len)
1250{
1251        fprintf(file, " %s%-*s |", prefix, len, name);
1252}
1253
1254static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1255{
1256        if (cnt <= 0)
1257                return;
1258        fprintf(file, "%s", set);
1259        while (cnt--)
1260                putc(ch, file);
1261        fprintf(file, "%s", reset);
1262}
1263
1264static void fill_print_name(struct diffstat_file *file)
1265{
1266        char *pname;
1267
1268        if (file->print_name)
1269                return;
1270
1271        if (!file->is_renamed) {
1272                struct strbuf buf = STRBUF_INIT;
1273                if (quote_c_style(file->name, &buf, NULL, 0)) {
1274                        pname = strbuf_detach(&buf, NULL);
1275                } else {
1276                        pname = file->name;
1277                        strbuf_release(&buf);
1278                }
1279        } else {
1280                pname = pprint_rename(file->from_name, file->name);
1281        }
1282        file->print_name = pname;
1283}
1284
1285static void show_stats(struct diffstat_t *data, struct diff_options *options)
1286{
1287        int i, len, add, del, adds = 0, dels = 0;
1288        uintmax_t max_change = 0, max_len = 0;
1289        int total_files = data->nr;
1290        int width, name_width;
1291        const char *reset, *add_c, *del_c;
1292        const char *line_prefix = "";
1293        struct strbuf *msg = NULL;
1294
1295        if (data->nr == 0)
1296                return;
1297
1298        if (options->output_prefix) {
1299                msg = options->output_prefix(options, options->output_prefix_data);
1300                line_prefix = msg->buf;
1301        }
1302
1303        width = options->stat_width ? options->stat_width : 80;
1304        name_width = options->stat_name_width ? options->stat_name_width : 50;
1305
1306        /* Sanity: give at least 5 columns to the graph,
1307         * but leave at least 10 columns for the name.
1308         */
1309        if (width < 25)
1310                width = 25;
1311        if (name_width < 10)
1312                name_width = 10;
1313        else if (width < name_width + 15)
1314                name_width = width - 15;
1315
1316        /* Find the longest filename and max number of changes */
1317        reset = diff_get_color_opt(options, DIFF_RESET);
1318        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1319        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1320
1321        for (i = 0; i < data->nr; i++) {
1322                struct diffstat_file *file = data->files[i];
1323                uintmax_t change = file->added + file->deleted;
1324                fill_print_name(file);
1325                len = strlen(file->print_name);
1326                if (max_len < len)
1327                        max_len = len;
1328
1329                if (file->is_binary || file->is_unmerged)
1330                        continue;
1331                if (max_change < change)
1332                        max_change = change;
1333        }
1334
1335        /* Compute the width of the graph part;
1336         * 10 is for one blank at the beginning of the line plus
1337         * " | count " between the name and the graph.
1338         *
1339         * From here on, name_width is the width of the name area,
1340         * and width is the width of the graph area.
1341         */
1342        name_width = (name_width < max_len) ? name_width : max_len;
1343        if (width < (name_width + 10) + max_change)
1344                width = width - (name_width + 10);
1345        else
1346                width = max_change;
1347
1348        for (i = 0; i < data->nr; i++) {
1349                const char *prefix = "";
1350                char *name = data->files[i]->print_name;
1351                uintmax_t added = data->files[i]->added;
1352                uintmax_t deleted = data->files[i]->deleted;
1353                int name_len;
1354
1355                /*
1356                 * "scale" the filename
1357                 */
1358                len = name_width;
1359                name_len = strlen(name);
1360                if (name_width < name_len) {
1361                        char *slash;
1362                        prefix = "...";
1363                        len -= 3;
1364                        name += name_len - len;
1365                        slash = strchr(name, '/');
1366                        if (slash)
1367                                name = slash;
1368                }
1369
1370                if (data->files[i]->is_binary) {
1371                        fprintf(options->file, "%s", line_prefix);
1372                        show_name(options->file, prefix, name, len);
1373                        fprintf(options->file, "  Bin ");
1374                        fprintf(options->file, "%s%"PRIuMAX"%s",
1375                                del_c, deleted, reset);
1376                        fprintf(options->file, " -> ");
1377                        fprintf(options->file, "%s%"PRIuMAX"%s",
1378                                add_c, added, reset);
1379                        fprintf(options->file, " bytes");
1380                        fprintf(options->file, "\n");
1381                        continue;
1382                }
1383                else if (data->files[i]->is_unmerged) {
1384                        fprintf(options->file, "%s", line_prefix);
1385                        show_name(options->file, prefix, name, len);
1386                        fprintf(options->file, "  Unmerged\n");
1387                        continue;
1388                }
1389                else if (!data->files[i]->is_renamed &&
1390                         (added + deleted == 0)) {
1391                        total_files--;
1392                        continue;
1393                }
1394
1395                /*
1396                 * scale the add/delete
1397                 */
1398                add = added;
1399                del = deleted;
1400                adds += add;
1401                dels += del;
1402
1403                if (width <= max_change) {
1404                        add = scale_linear(add, width, max_change);
1405                        del = scale_linear(del, width, max_change);
1406                }
1407                fprintf(options->file, "%s", line_prefix);
1408                show_name(options->file, prefix, name, len);
1409                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1410                                added + deleted ? " " : "");
1411                show_graph(options->file, '+', add, add_c, reset);
1412                show_graph(options->file, '-', del, del_c, reset);
1413                fprintf(options->file, "\n");
1414        }
1415        fprintf(options->file, "%s", line_prefix);
1416        fprintf(options->file,
1417               " %d files changed, %d insertions(+), %d deletions(-)\n",
1418               total_files, adds, dels);
1419}
1420
1421static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1422{
1423        int i, adds = 0, dels = 0, total_files = data->nr;
1424
1425        if (data->nr == 0)
1426                return;
1427
1428        for (i = 0; i < data->nr; i++) {
1429                if (!data->files[i]->is_binary &&
1430                    !data->files[i]->is_unmerged) {
1431                        int added = data->files[i]->added;
1432                        int deleted= data->files[i]->deleted;
1433                        if (!data->files[i]->is_renamed &&
1434                            (added + deleted == 0)) {
1435                                total_files--;
1436                        } else {
1437                                adds += added;
1438                                dels += deleted;
1439                        }
1440                }
1441        }
1442        if (options->output_prefix) {
1443                struct strbuf *msg = NULL;
1444                msg = options->output_prefix(options,
1445                                options->output_prefix_data);
1446                fprintf(options->file, "%s", msg->buf);
1447        }
1448        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1449               total_files, adds, dels);
1450}
1451
1452static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1453{
1454        int i;
1455
1456        if (data->nr == 0)
1457                return;
1458
1459        for (i = 0; i < data->nr; i++) {
1460                struct diffstat_file *file = data->files[i];
1461
1462                if (options->output_prefix) {
1463                        struct strbuf *msg = NULL;
1464                        msg = options->output_prefix(options,
1465                                        options->output_prefix_data);
1466                        fprintf(options->file, "%s", msg->buf);
1467                }
1468
1469                if (file->is_binary)
1470                        fprintf(options->file, "-\t-\t");
1471                else
1472                        fprintf(options->file,
1473                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1474                                file->added, file->deleted);
1475                if (options->line_termination) {
1476                        fill_print_name(file);
1477                        if (!file->is_renamed)
1478                                write_name_quoted(file->name, options->file,
1479                                                  options->line_termination);
1480                        else {
1481                                fputs(file->print_name, options->file);
1482                                putc(options->line_termination, options->file);
1483                        }
1484                } else {
1485                        if (file->is_renamed) {
1486                                putc('\0', options->file);
1487                                write_name_quoted(file->from_name, options->file, '\0');
1488                        }
1489                        write_name_quoted(file->name, options->file, '\0');
1490                }
1491        }
1492}
1493
1494struct dirstat_file {
1495        const char *name;
1496        unsigned long changed;
1497};
1498
1499struct dirstat_dir {
1500        struct dirstat_file *files;
1501        int alloc, nr, percent, cumulative;
1502};
1503
1504static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1505                unsigned long changed, const char *base, int baselen)
1506{
1507        unsigned long this_dir = 0;
1508        unsigned int sources = 0;
1509        const char *line_prefix = "";
1510        struct strbuf *msg = NULL;
1511
1512        if (opt->output_prefix) {
1513                msg = opt->output_prefix(opt, opt->output_prefix_data);
1514                line_prefix = msg->buf;
1515        }
1516
1517        while (dir->nr) {
1518                struct dirstat_file *f = dir->files;
1519                int namelen = strlen(f->name);
1520                unsigned long this;
1521                char *slash;
1522
1523                if (namelen < baselen)
1524                        break;
1525                if (memcmp(f->name, base, baselen))
1526                        break;
1527                slash = strchr(f->name + baselen, '/');
1528                if (slash) {
1529                        int newbaselen = slash + 1 - f->name;
1530                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1531                        sources++;
1532                } else {
1533                        this = f->changed;
1534                        dir->files++;
1535                        dir->nr--;
1536                        sources += 2;
1537                }
1538                this_dir += this;
1539        }
1540
1541        /*
1542         * We don't report dirstat's for
1543         *  - the top level
1544         *  - or cases where everything came from a single directory
1545         *    under this directory (sources == 1).
1546         */
1547        if (baselen && sources != 1) {
1548                if (this_dir) {
1549                        int permille = this_dir * 1000 / changed;
1550                        int percent = permille / 10;
1551                        if (percent >= dir->percent) {
1552                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1553                                        percent, permille % 10, baselen, base);
1554                                if (!dir->cumulative)
1555                                        return 0;
1556                        }
1557                }
1558        }
1559        return this_dir;
1560}
1561
1562static int dirstat_compare(const void *_a, const void *_b)
1563{
1564        const struct dirstat_file *a = _a;
1565        const struct dirstat_file *b = _b;
1566        return strcmp(a->name, b->name);
1567}
1568
1569static void show_dirstat(struct diff_options *options)
1570{
1571        int i;
1572        unsigned long changed;
1573        struct dirstat_dir dir;
1574        struct diff_queue_struct *q = &diff_queued_diff;
1575
1576        dir.files = NULL;
1577        dir.alloc = 0;
1578        dir.nr = 0;
1579        dir.percent = options->dirstat_percent;
1580        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1581
1582        changed = 0;
1583        for (i = 0; i < q->nr; i++) {
1584                struct diff_filepair *p = q->queue[i];
1585                const char *name;
1586                unsigned long copied, added, damage;
1587                int content_changed;
1588
1589                name = p->two->path ? p->two->path : p->one->path;
1590
1591                if (p->one->sha1_valid && p->two->sha1_valid)
1592                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1593                else
1594                        content_changed = 1;
1595
1596                if (!content_changed) {
1597                        /*
1598                         * The SHA1 has not changed, so pre-/post-content is
1599                         * identical. We can therefore skip looking at the
1600                         * file contents altogether.
1601                         */
1602                        damage = 0;
1603                        goto found_damage;
1604                }
1605
1606                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1607                        /*
1608                         * In --dirstat-by-file mode, we don't really need to
1609                         * look at the actual file contents at all.
1610                         * The fact that the SHA1 changed is enough for us to
1611                         * add this file to the list of results
1612                         * (with each file contributing equal damage).
1613                         */
1614                        damage = 1;
1615                        goto found_damage;
1616                }
1617
1618                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1619                        diff_populate_filespec(p->one, 0);
1620                        diff_populate_filespec(p->two, 0);
1621                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1622                                               &copied, &added);
1623                        diff_free_filespec_data(p->one);
1624                        diff_free_filespec_data(p->two);
1625                } else if (DIFF_FILE_VALID(p->one)) {
1626                        diff_populate_filespec(p->one, 1);
1627                        copied = added = 0;
1628                        diff_free_filespec_data(p->one);
1629                } else if (DIFF_FILE_VALID(p->two)) {
1630                        diff_populate_filespec(p->two, 1);
1631                        copied = 0;
1632                        added = p->two->size;
1633                        diff_free_filespec_data(p->two);
1634                } else
1635                        continue;
1636
1637                /*
1638                 * Original minus copied is the removed material,
1639                 * added is the new material.  They are both damages
1640                 * made to the preimage.
1641                 * If the resulting damage is zero, we know that
1642                 * diffcore_count_changes() considers the two entries to
1643                 * be identical, but since content_changed is true, we
1644                 * know that there must have been _some_ kind of change,
1645                 * so we force all entries to have damage > 0.
1646                 */
1647                damage = (p->one->size - copied) + added;
1648                if (!damage)
1649                        damage = 1;
1650
1651found_damage:
1652                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1653                dir.files[dir.nr].name = name;
1654                dir.files[dir.nr].changed = damage;
1655                changed += damage;
1656                dir.nr++;
1657        }
1658
1659        /* This can happen even with many files, if everything was renames */
1660        if (!changed)
1661                return;
1662
1663        /* Show all directories with more than x% of the changes */
1664        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1665        gather_dirstat(options, &dir, changed, "", 0);
1666}
1667
1668static void free_diffstat_info(struct diffstat_t *diffstat)
1669{
1670        int i;
1671        for (i = 0; i < diffstat->nr; i++) {
1672                struct diffstat_file *f = diffstat->files[i];
1673                if (f->name != f->print_name)
1674                        free(f->print_name);
1675                free(f->name);
1676                free(f->from_name);
1677                free(f);
1678        }
1679        free(diffstat->files);
1680}
1681
1682struct checkdiff_t {
1683        const char *filename;
1684        int lineno;
1685        int conflict_marker_size;
1686        struct diff_options *o;
1687        unsigned ws_rule;
1688        unsigned status;
1689};
1690
1691static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1692{
1693        char firstchar;
1694        int cnt;
1695
1696        if (len < marker_size + 1)
1697                return 0;
1698        firstchar = line[0];
1699        switch (firstchar) {
1700        case '=': case '>': case '<': case '|':
1701                break;
1702        default:
1703                return 0;
1704        }
1705        for (cnt = 1; cnt < marker_size; cnt++)
1706                if (line[cnt] != firstchar)
1707                        return 0;
1708        /* line[1] thru line[marker_size-1] are same as firstchar */
1709        if (len < marker_size + 1 || !isspace(line[marker_size]))
1710                return 0;
1711        return 1;
1712}
1713
1714static void checkdiff_consume(void *priv, char *line, unsigned long len)
1715{
1716        struct checkdiff_t *data = priv;
1717        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1718        int marker_size = data->conflict_marker_size;
1719        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1720        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1721        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1722        char *err;
1723        char *line_prefix = "";
1724        struct strbuf *msgbuf;
1725
1726        assert(data->o);
1727        if (data->o->output_prefix) {
1728                msgbuf = data->o->output_prefix(data->o,
1729                        data->o->output_prefix_data);
1730                line_prefix = msgbuf->buf;
1731        }
1732
1733        if (line[0] == '+') {
1734                unsigned bad;
1735                data->lineno++;
1736                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1737                        data->status |= 1;
1738                        fprintf(data->o->file,
1739                                "%s%s:%d: leftover conflict marker\n",
1740                                line_prefix, data->filename, data->lineno);
1741                }
1742                bad = ws_check(line + 1, len - 1, data->ws_rule);
1743                if (!bad)
1744                        return;
1745                data->status |= bad;
1746                err = whitespace_error_string(bad);
1747                fprintf(data->o->file, "%s%s:%d: %s.\n",
1748                        line_prefix, data->filename, data->lineno, err);
1749                free(err);
1750                emit_line(data->o, set, reset, line, 1);
1751                ws_check_emit(line + 1, len - 1, data->ws_rule,
1752                              data->o->file, set, reset, ws);
1753        } else if (line[0] == ' ') {
1754                data->lineno++;
1755        } else if (line[0] == '@') {
1756                char *plus = strchr(line, '+');
1757                if (plus)
1758                        data->lineno = strtol(plus, NULL, 10) - 1;
1759                else
1760                        die("invalid diff");
1761        }
1762}
1763
1764static unsigned char *deflate_it(char *data,
1765                                 unsigned long size,
1766                                 unsigned long *result_size)
1767{
1768        int bound;
1769        unsigned char *deflated;
1770        z_stream stream;
1771
1772        memset(&stream, 0, sizeof(stream));
1773        deflateInit(&stream, zlib_compression_level);
1774        bound = deflateBound(&stream, size);
1775        deflated = xmalloc(bound);
1776        stream.next_out = deflated;
1777        stream.avail_out = bound;
1778
1779        stream.next_in = (unsigned char *)data;
1780        stream.avail_in = size;
1781        while (deflate(&stream, Z_FINISH) == Z_OK)
1782                ; /* nothing */
1783        deflateEnd(&stream);
1784        *result_size = stream.total_out;
1785        return deflated;
1786}
1787
1788static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1789{
1790        void *cp;
1791        void *delta;
1792        void *deflated;
1793        void *data;
1794        unsigned long orig_size;
1795        unsigned long delta_size;
1796        unsigned long deflate_size;
1797        unsigned long data_size;
1798
1799        /* We could do deflated delta, or we could do just deflated two,
1800         * whichever is smaller.
1801         */
1802        delta = NULL;
1803        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1804        if (one->size && two->size) {
1805                delta = diff_delta(one->ptr, one->size,
1806                                   two->ptr, two->size,
1807                                   &delta_size, deflate_size);
1808                if (delta) {
1809                        void *to_free = delta;
1810                        orig_size = delta_size;
1811                        delta = deflate_it(delta, delta_size, &delta_size);
1812                        free(to_free);
1813                }
1814        }
1815
1816        if (delta && delta_size < deflate_size) {
1817                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1818                free(deflated);
1819                data = delta;
1820                data_size = delta_size;
1821        }
1822        else {
1823                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1824                free(delta);
1825                data = deflated;
1826                data_size = deflate_size;
1827        }
1828
1829        /* emit data encoded in base85 */
1830        cp = data;
1831        while (data_size) {
1832                int bytes = (52 < data_size) ? 52 : data_size;
1833                char line[70];
1834                data_size -= bytes;
1835                if (bytes <= 26)
1836                        line[0] = bytes + 'A' - 1;
1837                else
1838                        line[0] = bytes - 26 + 'a' - 1;
1839                encode_85(line + 1, cp, bytes);
1840                cp = (char *) cp + bytes;
1841                fprintf(file, "%s", prefix);
1842                fputs(line, file);
1843                fputc('\n', file);
1844        }
1845        fprintf(file, "%s\n", prefix);
1846        free(data);
1847}
1848
1849static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1850{
1851        fprintf(file, "%sGIT binary patch\n", prefix);
1852        emit_binary_diff_body(file, one, two, prefix);
1853        emit_binary_diff_body(file, two, one, prefix);
1854}
1855
1856static void diff_filespec_load_driver(struct diff_filespec *one)
1857{
1858        /* Use already-loaded driver */
1859        if (one->driver)
1860                return;
1861
1862        if (S_ISREG(one->mode))
1863                one->driver = userdiff_find_by_path(one->path);
1864
1865        /* Fallback to default settings */
1866        if (!one->driver)
1867                one->driver = userdiff_find_by_name("default");
1868}
1869
1870int diff_filespec_is_binary(struct diff_filespec *one)
1871{
1872        if (one->is_binary == -1) {
1873                diff_filespec_load_driver(one);
1874                if (one->driver->binary != -1)
1875                        one->is_binary = one->driver->binary;
1876                else {
1877                        if (!one->data && DIFF_FILE_VALID(one))
1878                                diff_populate_filespec(one, 0);
1879                        if (one->data)
1880                                one->is_binary = buffer_is_binary(one->data,
1881                                                one->size);
1882                        if (one->is_binary == -1)
1883                                one->is_binary = 0;
1884                }
1885        }
1886        return one->is_binary;
1887}
1888
1889static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1890{
1891        diff_filespec_load_driver(one);
1892        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1893}
1894
1895static const char *userdiff_word_regex(struct diff_filespec *one)
1896{
1897        diff_filespec_load_driver(one);
1898        return one->driver->word_regex;
1899}
1900
1901void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1902{
1903        if (!options->a_prefix)
1904                options->a_prefix = a;
1905        if (!options->b_prefix)
1906                options->b_prefix = b;
1907}
1908
1909struct userdiff_driver *get_textconv(struct diff_filespec *one)
1910{
1911        if (!DIFF_FILE_VALID(one))
1912                return NULL;
1913
1914        diff_filespec_load_driver(one);
1915        if (!one->driver->textconv)
1916                return NULL;
1917
1918        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1919                struct notes_cache *c = xmalloc(sizeof(*c));
1920                struct strbuf name = STRBUF_INIT;
1921
1922                strbuf_addf(&name, "textconv/%s", one->driver->name);
1923                notes_cache_init(c, name.buf, one->driver->textconv);
1924                one->driver->textconv_cache = c;
1925        }
1926
1927        return one->driver;
1928}
1929
1930static void builtin_diff(const char *name_a,
1931                         const char *name_b,
1932                         struct diff_filespec *one,
1933                         struct diff_filespec *two,
1934                         const char *xfrm_msg,
1935                         int must_show_header,
1936                         struct diff_options *o,
1937                         int complete_rewrite)
1938{
1939        mmfile_t mf1, mf2;
1940        const char *lbl[2];
1941        char *a_one, *b_two;
1942        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1943        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1944        const char *a_prefix, *b_prefix;
1945        struct userdiff_driver *textconv_one = NULL;
1946        struct userdiff_driver *textconv_two = NULL;
1947        struct strbuf header = STRBUF_INIT;
1948        struct strbuf *msgbuf;
1949        char *line_prefix = "";
1950
1951        if (o->output_prefix) {
1952                msgbuf = o->output_prefix(o, o->output_prefix_data);
1953                line_prefix = msgbuf->buf;
1954        }
1955
1956        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1957                        (!one->mode || S_ISGITLINK(one->mode)) &&
1958                        (!two->mode || S_ISGITLINK(two->mode))) {
1959                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1960                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1961                show_submodule_summary(o->file, one ? one->path : two->path,
1962                                one->sha1, two->sha1, two->dirty_submodule,
1963                                del, add, reset);
1964                return;
1965        }
1966
1967        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1968                textconv_one = get_textconv(one);
1969                textconv_two = get_textconv(two);
1970        }
1971
1972        diff_set_mnemonic_prefix(o, "a/", "b/");
1973        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1974                a_prefix = o->b_prefix;
1975                b_prefix = o->a_prefix;
1976        } else {
1977                a_prefix = o->a_prefix;
1978                b_prefix = o->b_prefix;
1979        }
1980
1981        /* Never use a non-valid filename anywhere if at all possible */
1982        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1983        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1984
1985        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1986        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1987        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1988        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1989        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1990        if (lbl[0][0] == '/') {
1991                /* /dev/null */
1992                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1993                if (xfrm_msg)
1994                        strbuf_addstr(&header, xfrm_msg);
1995                must_show_header = 1;
1996        }
1997        else if (lbl[1][0] == '/') {
1998                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1999                if (xfrm_msg)
2000                        strbuf_addstr(&header, xfrm_msg);
2001                must_show_header = 1;
2002        }
2003        else {
2004                if (one->mode != two->mode) {
2005                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2006                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2007                        must_show_header = 1;
2008                }
2009                if (xfrm_msg)
2010                        strbuf_addstr(&header, xfrm_msg);
2011
2012                /*
2013                 * we do not run diff between different kind
2014                 * of objects.
2015                 */
2016                if ((one->mode ^ two->mode) & S_IFMT)
2017                        goto free_ab_and_return;
2018                if (complete_rewrite &&
2019                    (textconv_one || !diff_filespec_is_binary(one)) &&
2020                    (textconv_two || !diff_filespec_is_binary(two))) {
2021                        fprintf(o->file, "%s", header.buf);
2022                        strbuf_reset(&header);
2023                        emit_rewrite_diff(name_a, name_b, one, two,
2024                                                textconv_one, textconv_two, o);
2025                        o->found_changes = 1;
2026                        goto free_ab_and_return;
2027                }
2028        }
2029
2030        if (o->irreversible_delete && lbl[1][0] == '/') {
2031                fprintf(o->file, "%s", header.buf);
2032                strbuf_reset(&header);
2033                goto free_ab_and_return;
2034        } else if (!DIFF_OPT_TST(o, TEXT) &&
2035            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2036              (!textconv_two && diff_filespec_is_binary(two)) )) {
2037                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2038                        die("unable to read files to diff");
2039                /* Quite common confusing case */
2040                if (mf1.size == mf2.size &&
2041                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2042                        if (must_show_header)
2043                                fprintf(o->file, "%s", header.buf);
2044                        goto free_ab_and_return;
2045                }
2046                fprintf(o->file, "%s", header.buf);
2047                strbuf_reset(&header);
2048                if (DIFF_OPT_TST(o, BINARY))
2049                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2050                else
2051                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2052                                line_prefix, lbl[0], lbl[1]);
2053                o->found_changes = 1;
2054        } else {
2055                /* Crazy xdl interfaces.. */
2056                const char *diffopts = getenv("GIT_DIFF_OPTS");
2057                xpparam_t xpp;
2058                xdemitconf_t xecfg;
2059                struct emit_callback ecbdata;
2060                const struct userdiff_funcname *pe;
2061
2062                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2063                        fprintf(o->file, "%s", header.buf);
2064                        strbuf_reset(&header);
2065                }
2066
2067                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2068                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2069
2070                pe = diff_funcname_pattern(one);
2071                if (!pe)
2072                        pe = diff_funcname_pattern(two);
2073
2074                memset(&xpp, 0, sizeof(xpp));
2075                memset(&xecfg, 0, sizeof(xecfg));
2076                memset(&ecbdata, 0, sizeof(ecbdata));
2077                ecbdata.label_path = lbl;
2078                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2079                ecbdata.found_changesp = &o->found_changes;
2080                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2081                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2082                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2083                ecbdata.opt = o;
2084                ecbdata.header = header.len ? &header : NULL;
2085                xpp.flags = o->xdl_opts;
2086                xecfg.ctxlen = o->context;
2087                xecfg.interhunkctxlen = o->interhunkcontext;
2088                xecfg.flags = XDL_EMIT_FUNCNAMES;
2089                if (pe)
2090                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2091                if (!diffopts)
2092                        ;
2093                else if (!prefixcmp(diffopts, "--unified="))
2094                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2095                else if (!prefixcmp(diffopts, "-u"))
2096                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2097                if (o->word_diff) {
2098                        int i;
2099
2100                        ecbdata.diff_words =
2101                                xcalloc(1, sizeof(struct diff_words_data));
2102                        ecbdata.diff_words->type = o->word_diff;
2103                        ecbdata.diff_words->opt = o;
2104                        if (!o->word_regex)
2105                                o->word_regex = userdiff_word_regex(one);
2106                        if (!o->word_regex)
2107                                o->word_regex = userdiff_word_regex(two);
2108                        if (!o->word_regex)
2109                                o->word_regex = diff_word_regex_cfg;
2110                        if (o->word_regex) {
2111                                ecbdata.diff_words->word_regex = (regex_t *)
2112                                        xmalloc(sizeof(regex_t));
2113                                if (regcomp(ecbdata.diff_words->word_regex,
2114                                                o->word_regex,
2115                                                REG_EXTENDED | REG_NEWLINE))
2116                                        die ("Invalid regular expression: %s",
2117                                                        o->word_regex);
2118                        }
2119                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2120                                if (o->word_diff == diff_words_styles[i].type) {
2121                                        ecbdata.diff_words->style =
2122                                                &diff_words_styles[i];
2123                                        break;
2124                                }
2125                        }
2126                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2127                                struct diff_words_style *st = ecbdata.diff_words->style;
2128                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2129                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2130                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2131                        }
2132                }
2133                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2134                              &xpp, &xecfg);
2135                if (o->word_diff)
2136                        free_diff_words_data(&ecbdata);
2137                if (textconv_one)
2138                        free(mf1.ptr);
2139                if (textconv_two)
2140                        free(mf2.ptr);
2141                xdiff_clear_find_func(&xecfg);
2142        }
2143
2144 free_ab_and_return:
2145        strbuf_release(&header);
2146        diff_free_filespec_data(one);
2147        diff_free_filespec_data(two);
2148        free(a_one);
2149        free(b_two);
2150        return;
2151}
2152
2153static void builtin_diffstat(const char *name_a, const char *name_b,
2154                             struct diff_filespec *one,
2155                             struct diff_filespec *two,
2156                             struct diffstat_t *diffstat,
2157                             struct diff_options *o,
2158                             int complete_rewrite)
2159{
2160        mmfile_t mf1, mf2;
2161        struct diffstat_file *data;
2162
2163        data = diffstat_add(diffstat, name_a, name_b);
2164
2165        if (!one || !two) {
2166                data->is_unmerged = 1;
2167                return;
2168        }
2169
2170        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2171                data->is_binary = 1;
2172                data->added = diff_filespec_size(two);
2173                data->deleted = diff_filespec_size(one);
2174        }
2175
2176        else if (complete_rewrite) {
2177                diff_populate_filespec(one, 0);
2178                diff_populate_filespec(two, 0);
2179                data->deleted = count_lines(one->data, one->size);
2180                data->added = count_lines(two->data, two->size);
2181        }
2182
2183        else {
2184                /* Crazy xdl interfaces.. */
2185                xpparam_t xpp;
2186                xdemitconf_t xecfg;
2187
2188                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2189                        die("unable to read files to diff");
2190
2191                memset(&xpp, 0, sizeof(xpp));
2192                memset(&xecfg, 0, sizeof(xecfg));
2193                xpp.flags = o->xdl_opts;
2194                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2195                              &xpp, &xecfg);
2196        }
2197
2198        diff_free_filespec_data(one);
2199        diff_free_filespec_data(two);
2200}
2201
2202static void builtin_checkdiff(const char *name_a, const char *name_b,
2203                              const char *attr_path,
2204                              struct diff_filespec *one,
2205                              struct diff_filespec *two,
2206                              struct diff_options *o)
2207{
2208        mmfile_t mf1, mf2;
2209        struct checkdiff_t data;
2210
2211        if (!two)
2212                return;
2213
2214        memset(&data, 0, sizeof(data));
2215        data.filename = name_b ? name_b : name_a;
2216        data.lineno = 0;
2217        data.o = o;
2218        data.ws_rule = whitespace_rule(attr_path);
2219        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2220
2221        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2222                die("unable to read files to diff");
2223
2224        /*
2225         * All the other codepaths check both sides, but not checking
2226         * the "old" side here is deliberate.  We are checking the newly
2227         * introduced changes, and as long as the "new" side is text, we
2228         * can and should check what it introduces.
2229         */
2230        if (diff_filespec_is_binary(two))
2231                goto free_and_return;
2232        else {
2233                /* Crazy xdl interfaces.. */
2234                xpparam_t xpp;
2235                xdemitconf_t xecfg;
2236
2237                memset(&xpp, 0, sizeof(xpp));
2238                memset(&xecfg, 0, sizeof(xecfg));
2239                xecfg.ctxlen = 1; /* at least one context line */
2240                xpp.flags = 0;
2241                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2242                              &xpp, &xecfg);
2243
2244                if (data.ws_rule & WS_BLANK_AT_EOF) {
2245                        struct emit_callback ecbdata;
2246                        int blank_at_eof;
2247
2248                        ecbdata.ws_rule = data.ws_rule;
2249                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2250                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2251
2252                        if (blank_at_eof) {
2253                                static char *err;
2254                                if (!err)
2255                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2256                                fprintf(o->file, "%s:%d: %s.\n",
2257                                        data.filename, blank_at_eof, err);
2258                                data.status = 1; /* report errors */
2259                        }
2260                }
2261        }
2262 free_and_return:
2263        diff_free_filespec_data(one);
2264        diff_free_filespec_data(two);
2265        if (data.status)
2266                DIFF_OPT_SET(o, CHECK_FAILED);
2267}
2268
2269struct diff_filespec *alloc_filespec(const char *path)
2270{
2271        int namelen = strlen(path);
2272        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2273
2274        memset(spec, 0, sizeof(*spec));
2275        spec->path = (char *)(spec + 1);
2276        memcpy(spec->path, path, namelen+1);
2277        spec->count = 1;
2278        spec->is_binary = -1;
2279        return spec;
2280}
2281
2282void free_filespec(struct diff_filespec *spec)
2283{
2284        if (!--spec->count) {
2285                diff_free_filespec_data(spec);
2286                free(spec);
2287        }
2288}
2289
2290void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2291                   unsigned short mode)
2292{
2293        if (mode) {
2294                spec->mode = canon_mode(mode);
2295                hashcpy(spec->sha1, sha1);
2296                spec->sha1_valid = !is_null_sha1(sha1);
2297        }
2298}
2299
2300/*
2301 * Given a name and sha1 pair, if the index tells us the file in
2302 * the work tree has that object contents, return true, so that
2303 * prepare_temp_file() does not have to inflate and extract.
2304 */
2305static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2306{
2307        struct cache_entry *ce;
2308        struct stat st;
2309        int pos, len;
2310
2311        /*
2312         * We do not read the cache ourselves here, because the
2313         * benchmark with my previous version that always reads cache
2314         * shows that it makes things worse for diff-tree comparing
2315         * two linux-2.6 kernel trees in an already checked out work
2316         * tree.  This is because most diff-tree comparisons deal with
2317         * only a small number of files, while reading the cache is
2318         * expensive for a large project, and its cost outweighs the
2319         * savings we get by not inflating the object to a temporary
2320         * file.  Practically, this code only helps when we are used
2321         * by diff-cache --cached, which does read the cache before
2322         * calling us.
2323         */
2324        if (!active_cache)
2325                return 0;
2326
2327        /* We want to avoid the working directory if our caller
2328         * doesn't need the data in a normal file, this system
2329         * is rather slow with its stat/open/mmap/close syscalls,
2330         * and the object is contained in a pack file.  The pack
2331         * is probably already open and will be faster to obtain
2332         * the data through than the working directory.  Loose
2333         * objects however would tend to be slower as they need
2334         * to be individually opened and inflated.
2335         */
2336        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2337                return 0;
2338
2339        len = strlen(name);
2340        pos = cache_name_pos(name, len);
2341        if (pos < 0)
2342                return 0;
2343        ce = active_cache[pos];
2344
2345        /*
2346         * This is not the sha1 we are looking for, or
2347         * unreusable because it is not a regular file.
2348         */
2349        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2350                return 0;
2351
2352        /*
2353         * If ce is marked as "assume unchanged", there is no
2354         * guarantee that work tree matches what we are looking for.
2355         */
2356        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2357                return 0;
2358
2359        /*
2360         * If ce matches the file in the work tree, we can reuse it.
2361         */
2362        if (ce_uptodate(ce) ||
2363            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2364                return 1;
2365
2366        return 0;
2367}
2368
2369static int populate_from_stdin(struct diff_filespec *s)
2370{
2371        struct strbuf buf = STRBUF_INIT;
2372        size_t size = 0;
2373
2374        if (strbuf_read(&buf, 0, 0) < 0)
2375                return error("error while reading from stdin %s",
2376                                     strerror(errno));
2377
2378        s->should_munmap = 0;
2379        s->data = strbuf_detach(&buf, &size);
2380        s->size = size;
2381        s->should_free = 1;
2382        return 0;
2383}
2384
2385static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2386{
2387        int len;
2388        char *data = xmalloc(100), *dirty = "";
2389
2390        /* Are we looking at the work tree? */
2391        if (s->dirty_submodule)
2392                dirty = "-dirty";
2393
2394        len = snprintf(data, 100,
2395                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2396        s->data = data;
2397        s->size = len;
2398        s->should_free = 1;
2399        if (size_only) {
2400                s->data = NULL;
2401                free(data);
2402        }
2403        return 0;
2404}
2405
2406/*
2407 * While doing rename detection and pickaxe operation, we may need to
2408 * grab the data for the blob (or file) for our own in-core comparison.
2409 * diff_filespec has data and size fields for this purpose.
2410 */
2411int diff_populate_filespec(struct diff_filespec *s, int size_only)
2412{
2413        int err = 0;
2414        if (!DIFF_FILE_VALID(s))
2415                die("internal error: asking to populate invalid file.");
2416        if (S_ISDIR(s->mode))
2417                return -1;
2418
2419        if (s->data)
2420                return 0;
2421
2422        if (size_only && 0 < s->size)
2423                return 0;
2424
2425        if (S_ISGITLINK(s->mode))
2426                return diff_populate_gitlink(s, size_only);
2427
2428        if (!s->sha1_valid ||
2429            reuse_worktree_file(s->path, s->sha1, 0)) {
2430                struct strbuf buf = STRBUF_INIT;
2431                struct stat st;
2432                int fd;
2433
2434                if (!strcmp(s->path, "-"))
2435                        return populate_from_stdin(s);
2436
2437                if (lstat(s->path, &st) < 0) {
2438                        if (errno == ENOENT) {
2439                        err_empty:
2440                                err = -1;
2441                        empty:
2442                                s->data = (char *)"";
2443                                s->size = 0;
2444                                return err;
2445                        }
2446                }
2447                s->size = xsize_t(st.st_size);
2448                if (!s->size)
2449                        goto empty;
2450                if (S_ISLNK(st.st_mode)) {
2451                        struct strbuf sb = STRBUF_INIT;
2452
2453                        if (strbuf_readlink(&sb, s->path, s->size))
2454                                goto err_empty;
2455                        s->size = sb.len;
2456                        s->data = strbuf_detach(&sb, NULL);
2457                        s->should_free = 1;
2458                        return 0;
2459                }
2460                if (size_only)
2461                        return 0;
2462                fd = open(s->path, O_RDONLY);
2463                if (fd < 0)
2464                        goto err_empty;
2465                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2466                close(fd);
2467                s->should_munmap = 1;
2468
2469                /*
2470                 * Convert from working tree format to canonical git format
2471                 */
2472                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2473                        size_t size = 0;
2474                        munmap(s->data, s->size);
2475                        s->should_munmap = 0;
2476                        s->data = strbuf_detach(&buf, &size);
2477                        s->size = size;
2478                        s->should_free = 1;
2479                }
2480        }
2481        else {
2482                enum object_type type;
2483                if (size_only) {
2484                        type = sha1_object_info(s->sha1, &s->size);
2485                        if (type < 0)
2486                                die("unable to read %s", sha1_to_hex(s->sha1));
2487                } else {
2488                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2489                        if (!s->data)
2490                                die("unable to read %s", sha1_to_hex(s->sha1));
2491                        s->should_free = 1;
2492                }
2493        }
2494        return 0;
2495}
2496
2497void diff_free_filespec_blob(struct diff_filespec *s)
2498{
2499        if (s->should_free)
2500                free(s->data);
2501        else if (s->should_munmap)
2502                munmap(s->data, s->size);
2503
2504        if (s->should_free || s->should_munmap) {
2505                s->should_free = s->should_munmap = 0;
2506                s->data = NULL;
2507        }
2508}
2509
2510void diff_free_filespec_data(struct diff_filespec *s)
2511{
2512        diff_free_filespec_blob(s);
2513        free(s->cnt_data);
2514        s->cnt_data = NULL;
2515}
2516
2517static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2518                           void *blob,
2519                           unsigned long size,
2520                           const unsigned char *sha1,
2521                           int mode)
2522{
2523        int fd;
2524        struct strbuf buf = STRBUF_INIT;
2525        struct strbuf template = STRBUF_INIT;
2526        char *path_dup = xstrdup(path);
2527        const char *base = basename(path_dup);
2528
2529        /* Generate "XXXXXX_basename.ext" */
2530        strbuf_addstr(&template, "XXXXXX_");
2531        strbuf_addstr(&template, base);
2532
2533        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2534                        strlen(base) + 1);
2535        if (fd < 0)
2536                die_errno("unable to create temp-file");
2537        if (convert_to_working_tree(path,
2538                        (const char *)blob, (size_t)size, &buf)) {
2539                blob = buf.buf;
2540                size = buf.len;
2541        }
2542        if (write_in_full(fd, blob, size) != size)
2543                die_errno("unable to write temp-file");
2544        close(fd);
2545        temp->name = temp->tmp_path;
2546        strcpy(temp->hex, sha1_to_hex(sha1));
2547        temp->hex[40] = 0;
2548        sprintf(temp->mode, "%06o", mode);
2549        strbuf_release(&buf);
2550        strbuf_release(&template);
2551        free(path_dup);
2552}
2553
2554static struct diff_tempfile *prepare_temp_file(const char *name,
2555                struct diff_filespec *one)
2556{
2557        struct diff_tempfile *temp = claim_diff_tempfile();
2558
2559        if (!DIFF_FILE_VALID(one)) {
2560        not_a_valid_file:
2561                /* A '-' entry produces this for file-2, and
2562                 * a '+' entry produces this for file-1.
2563                 */
2564                temp->name = "/dev/null";
2565                strcpy(temp->hex, ".");
2566                strcpy(temp->mode, ".");
2567                return temp;
2568        }
2569
2570        if (!remove_tempfile_installed) {
2571                atexit(remove_tempfile);
2572                sigchain_push_common(remove_tempfile_on_signal);
2573                remove_tempfile_installed = 1;
2574        }
2575
2576        if (!one->sha1_valid ||
2577            reuse_worktree_file(name, one->sha1, 1)) {
2578                struct stat st;
2579                if (lstat(name, &st) < 0) {
2580                        if (errno == ENOENT)
2581                                goto not_a_valid_file;
2582                        die_errno("stat(%s)", name);
2583                }
2584                if (S_ISLNK(st.st_mode)) {
2585                        struct strbuf sb = STRBUF_INIT;
2586                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2587                                die_errno("readlink(%s)", name);
2588                        prep_temp_blob(name, temp, sb.buf, sb.len,
2589                                       (one->sha1_valid ?
2590                                        one->sha1 : null_sha1),
2591                                       (one->sha1_valid ?
2592                                        one->mode : S_IFLNK));
2593                        strbuf_release(&sb);
2594                }
2595                else {
2596                        /* we can borrow from the file in the work tree */
2597                        temp->name = name;
2598                        if (!one->sha1_valid)
2599                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2600                        else
2601                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2602                        /* Even though we may sometimes borrow the
2603                         * contents from the work tree, we always want
2604                         * one->mode.  mode is trustworthy even when
2605                         * !(one->sha1_valid), as long as
2606                         * DIFF_FILE_VALID(one).
2607                         */
2608                        sprintf(temp->mode, "%06o", one->mode);
2609                }
2610                return temp;
2611        }
2612        else {
2613                if (diff_populate_filespec(one, 0))
2614                        die("cannot read data blob for %s", one->path);
2615                prep_temp_blob(name, temp, one->data, one->size,
2616                               one->sha1, one->mode);
2617        }
2618        return temp;
2619}
2620
2621/* An external diff command takes:
2622 *
2623 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2624 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2625 *
2626 */
2627static void run_external_diff(const char *pgm,
2628                              const char *name,
2629                              const char *other,
2630                              struct diff_filespec *one,
2631                              struct diff_filespec *two,
2632                              const char *xfrm_msg,
2633                              int complete_rewrite)
2634{
2635        const char *spawn_arg[10];
2636        int retval;
2637        const char **arg = &spawn_arg[0];
2638
2639        if (one && two) {
2640                struct diff_tempfile *temp_one, *temp_two;
2641                const char *othername = (other ? other : name);
2642                temp_one = prepare_temp_file(name, one);
2643                temp_two = prepare_temp_file(othername, two);
2644                *arg++ = pgm;
2645                *arg++ = name;
2646                *arg++ = temp_one->name;
2647                *arg++ = temp_one->hex;
2648                *arg++ = temp_one->mode;
2649                *arg++ = temp_two->name;
2650                *arg++ = temp_two->hex;
2651                *arg++ = temp_two->mode;
2652                if (other) {
2653                        *arg++ = other;
2654                        *arg++ = xfrm_msg;
2655                }
2656        } else {
2657                *arg++ = pgm;
2658                *arg++ = name;
2659        }
2660        *arg = NULL;
2661        fflush(NULL);
2662        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2663        remove_tempfile();
2664        if (retval) {
2665                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2666                exit(1);
2667        }
2668}
2669
2670static int similarity_index(struct diff_filepair *p)
2671{
2672        return p->score * 100 / MAX_SCORE;
2673}
2674
2675static void fill_metainfo(struct strbuf *msg,
2676                          const char *name,
2677                          const char *other,
2678                          struct diff_filespec *one,
2679                          struct diff_filespec *two,
2680                          struct diff_options *o,
2681                          struct diff_filepair *p,
2682                          int *must_show_header,
2683                          int use_color)
2684{
2685        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2686        const char *reset = diff_get_color(use_color, DIFF_RESET);
2687        struct strbuf *msgbuf;
2688        char *line_prefix = "";
2689
2690        *must_show_header = 1;
2691        if (o->output_prefix) {
2692                msgbuf = o->output_prefix(o, o->output_prefix_data);
2693                line_prefix = msgbuf->buf;
2694        }
2695        strbuf_init(msg, PATH_MAX * 2 + 300);
2696        switch (p->status) {
2697        case DIFF_STATUS_COPIED:
2698                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2699                            line_prefix, set, similarity_index(p));
2700                strbuf_addf(msg, "%s\n%s%scopy from ",
2701                            reset,  line_prefix, set);
2702                quote_c_style(name, msg, NULL, 0);
2703                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2704                quote_c_style(other, msg, NULL, 0);
2705                strbuf_addf(msg, "%s\n", reset);
2706                break;
2707        case DIFF_STATUS_RENAMED:
2708                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2709                            line_prefix, set, similarity_index(p));
2710                strbuf_addf(msg, "%s\n%s%srename from ",
2711                            reset, line_prefix, set);
2712                quote_c_style(name, msg, NULL, 0);
2713                strbuf_addf(msg, "%s\n%s%srename to ",
2714                            reset, line_prefix, set);
2715                quote_c_style(other, msg, NULL, 0);
2716                strbuf_addf(msg, "%s\n", reset);
2717                break;
2718        case DIFF_STATUS_MODIFIED:
2719                if (p->score) {
2720                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2721                                    line_prefix,
2722                                    set, similarity_index(p), reset);
2723                        break;
2724                }
2725                /* fallthru */
2726        default:
2727                *must_show_header = 0;
2728        }
2729        if (one && two && hashcmp(one->sha1, two->sha1)) {
2730                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2731
2732                if (DIFF_OPT_TST(o, BINARY)) {
2733                        mmfile_t mf;
2734                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2735                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2736                                abbrev = 40;
2737                }
2738                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2739                            find_unique_abbrev(one->sha1, abbrev));
2740                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2741                if (one->mode == two->mode)
2742                        strbuf_addf(msg, " %06o", one->mode);
2743                strbuf_addf(msg, "%s\n", reset);
2744        }
2745}
2746
2747static void run_diff_cmd(const char *pgm,
2748                         const char *name,
2749                         const char *other,
2750                         const char *attr_path,
2751                         struct diff_filespec *one,
2752                         struct diff_filespec *two,
2753                         struct strbuf *msg,
2754                         struct diff_options *o,
2755                         struct diff_filepair *p)
2756{
2757        const char *xfrm_msg = NULL;
2758        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2759        int must_show_header = 0;
2760
2761        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2762                pgm = NULL;
2763        else {
2764                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2765                if (drv && drv->external)
2766                        pgm = drv->external;
2767        }
2768
2769        if (msg) {
2770                /*
2771                 * don't use colors when the header is intended for an
2772                 * external diff driver
2773                 */
2774                fill_metainfo(msg, name, other, one, two, o, p,
2775                              &must_show_header,
2776                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2777                xfrm_msg = msg->len ? msg->buf : NULL;
2778        }
2779
2780        if (pgm) {
2781                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2782                                  complete_rewrite);
2783                return;
2784        }
2785        if (one && two)
2786                builtin_diff(name, other ? other : name,
2787                             one, two, xfrm_msg, must_show_header,
2788                             o, complete_rewrite);
2789        else
2790                fprintf(o->file, "* Unmerged path %s\n", name);
2791}
2792
2793static void diff_fill_sha1_info(struct diff_filespec *one)
2794{
2795        if (DIFF_FILE_VALID(one)) {
2796                if (!one->sha1_valid) {
2797                        struct stat st;
2798                        if (!strcmp(one->path, "-")) {
2799                                hashcpy(one->sha1, null_sha1);
2800                                return;
2801                        }
2802                        if (lstat(one->path, &st) < 0)
2803                                die_errno("stat '%s'", one->path);
2804                        if (index_path(one->sha1, one->path, &st, 0))
2805                                die("cannot hash %s", one->path);
2806                }
2807        }
2808        else
2809                hashclr(one->sha1);
2810}
2811
2812static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2813{
2814        /* Strip the prefix but do not molest /dev/null and absolute paths */
2815        if (*namep && **namep != '/') {
2816                *namep += prefix_length;
2817                if (**namep == '/')
2818                        ++*namep;
2819        }
2820        if (*otherp && **otherp != '/') {
2821                *otherp += prefix_length;
2822                if (**otherp == '/')
2823                        ++*otherp;
2824        }
2825}
2826
2827static void run_diff(struct diff_filepair *p, struct diff_options *o)
2828{
2829        const char *pgm = external_diff();
2830        struct strbuf msg;
2831        struct diff_filespec *one = p->one;
2832        struct diff_filespec *two = p->two;
2833        const char *name;
2834        const char *other;
2835        const char *attr_path;
2836
2837        name  = p->one->path;
2838        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2839        attr_path = name;
2840        if (o->prefix_length)
2841                strip_prefix(o->prefix_length, &name, &other);
2842
2843        if (DIFF_PAIR_UNMERGED(p)) {
2844                run_diff_cmd(pgm, name, NULL, attr_path,
2845                             NULL, NULL, NULL, o, p);
2846                return;
2847        }
2848
2849        diff_fill_sha1_info(one);
2850        diff_fill_sha1_info(two);
2851
2852        if (!pgm &&
2853            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2854            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2855                /*
2856                 * a filepair that changes between file and symlink
2857                 * needs to be split into deletion and creation.
2858                 */
2859                struct diff_filespec *null = alloc_filespec(two->path);
2860                run_diff_cmd(NULL, name, other, attr_path,
2861                             one, null, &msg, o, p);
2862                free(null);
2863                strbuf_release(&msg);
2864
2865                null = alloc_filespec(one->path);
2866                run_diff_cmd(NULL, name, other, attr_path,
2867                             null, two, &msg, o, p);
2868                free(null);
2869        }
2870        else
2871                run_diff_cmd(pgm, name, other, attr_path,
2872                             one, two, &msg, o, p);
2873
2874        strbuf_release(&msg);
2875}
2876
2877static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2878                         struct diffstat_t *diffstat)
2879{
2880        const char *name;
2881        const char *other;
2882        int complete_rewrite = 0;
2883
2884        if (DIFF_PAIR_UNMERGED(p)) {
2885                /* unmerged */
2886                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2887                return;
2888        }
2889
2890        name = p->one->path;
2891        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2892
2893        if (o->prefix_length)
2894                strip_prefix(o->prefix_length, &name, &other);
2895
2896        diff_fill_sha1_info(p->one);
2897        diff_fill_sha1_info(p->two);
2898
2899        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2900                complete_rewrite = 1;
2901        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2902}
2903
2904static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2905{
2906        const char *name;
2907        const char *other;
2908        const char *attr_path;
2909
2910        if (DIFF_PAIR_UNMERGED(p)) {
2911                /* unmerged */
2912                return;
2913        }
2914
2915        name = p->one->path;
2916        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2917        attr_path = other ? other : name;
2918
2919        if (o->prefix_length)
2920                strip_prefix(o->prefix_length, &name, &other);
2921
2922        diff_fill_sha1_info(p->one);
2923        diff_fill_sha1_info(p->two);
2924
2925        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2926}
2927
2928void diff_setup(struct diff_options *options)
2929{
2930        memcpy(options, &default_diff_options, sizeof(*options));
2931
2932        options->file = stdout;
2933
2934        options->line_termination = '\n';
2935        options->break_opt = -1;
2936        options->rename_limit = -1;
2937        options->dirstat_percent = diff_dirstat_percent_default;
2938        options->context = 3;
2939
2940        options->change = diff_change;
2941        options->add_remove = diff_addremove;
2942        if (diff_use_color_default > 0)
2943                DIFF_OPT_SET(options, COLOR_DIFF);
2944        options->detect_rename = diff_detect_rename_default;
2945
2946        if (diff_no_prefix) {
2947                options->a_prefix = options->b_prefix = "";
2948        } else if (!diff_mnemonic_prefix) {
2949                options->a_prefix = "a/";
2950                options->b_prefix = "b/";
2951        }
2952}
2953
2954int diff_setup_done(struct diff_options *options)
2955{
2956        int count = 0;
2957
2958        if (options->output_format & DIFF_FORMAT_NAME)
2959                count++;
2960        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2961                count++;
2962        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2963                count++;
2964        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2965                count++;
2966        if (count > 1)
2967                die("--name-only, --name-status, --check and -s are mutually exclusive");
2968
2969        /*
2970         * Most of the time we can say "there are changes"
2971         * only by checking if there are changed paths, but
2972         * --ignore-whitespace* options force us to look
2973         * inside contents.
2974         */
2975
2976        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2977            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2978            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2979                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2980        else
2981                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2982
2983        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2984                options->detect_rename = DIFF_DETECT_COPY;
2985
2986        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2987                options->prefix = NULL;
2988        if (options->prefix)
2989                options->prefix_length = strlen(options->prefix);
2990        else
2991                options->prefix_length = 0;
2992
2993        if (options->output_format & (DIFF_FORMAT_NAME |
2994                                      DIFF_FORMAT_NAME_STATUS |
2995                                      DIFF_FORMAT_CHECKDIFF |
2996                                      DIFF_FORMAT_NO_OUTPUT))
2997                options->output_format &= ~(DIFF_FORMAT_RAW |
2998                                            DIFF_FORMAT_NUMSTAT |
2999                                            DIFF_FORMAT_DIFFSTAT |
3000                                            DIFF_FORMAT_SHORTSTAT |
3001                                            DIFF_FORMAT_DIRSTAT |
3002                                            DIFF_FORMAT_SUMMARY |
3003                                            DIFF_FORMAT_PATCH);
3004
3005        /*
3006         * These cases always need recursive; we do not drop caller-supplied
3007         * recursive bits for other formats here.
3008         */
3009        if (options->output_format & (DIFF_FORMAT_PATCH |
3010                                      DIFF_FORMAT_NUMSTAT |
3011                                      DIFF_FORMAT_DIFFSTAT |
3012                                      DIFF_FORMAT_SHORTSTAT |
3013                                      DIFF_FORMAT_DIRSTAT |
3014                                      DIFF_FORMAT_SUMMARY |
3015                                      DIFF_FORMAT_CHECKDIFF))
3016                DIFF_OPT_SET(options, RECURSIVE);
3017        /*
3018         * Also pickaxe would not work very well if you do not say recursive
3019         */
3020        if (options->pickaxe)
3021                DIFF_OPT_SET(options, RECURSIVE);
3022        /*
3023         * When patches are generated, submodules diffed against the work tree
3024         * must be checked for dirtiness too so it can be shown in the output
3025         */
3026        if (options->output_format & DIFF_FORMAT_PATCH)
3027                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3028
3029        if (options->detect_rename && options->rename_limit < 0)
3030                options->rename_limit = diff_rename_limit_default;
3031        if (options->setup & DIFF_SETUP_USE_CACHE) {
3032                if (!active_cache)
3033                        /* read-cache does not die even when it fails
3034                         * so it is safe for us to do this here.  Also
3035                         * it does not smudge active_cache or active_nr
3036                         * when it fails, so we do not have to worry about
3037                         * cleaning it up ourselves either.
3038                         */
3039                        read_cache();
3040        }
3041        if (options->abbrev <= 0 || 40 < options->abbrev)
3042                options->abbrev = 40; /* full */
3043
3044        /*
3045         * It does not make sense to show the first hit we happened
3046         * to have found.  It does not make sense not to return with
3047         * exit code in such a case either.
3048         */
3049        if (DIFF_OPT_TST(options, QUICK)) {
3050                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3051                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3052        }
3053
3054        return 0;
3055}
3056
3057static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3058{
3059        char c, *eq;
3060        int len;
3061
3062        if (*arg != '-')
3063                return 0;
3064        c = *++arg;
3065        if (!c)
3066                return 0;
3067        if (c == arg_short) {
3068                c = *++arg;
3069                if (!c)
3070                        return 1;
3071                if (val && isdigit(c)) {
3072                        char *end;
3073                        int n = strtoul(arg, &end, 10);
3074                        if (*end)
3075                                return 0;
3076                        *val = n;
3077                        return 1;
3078                }
3079                return 0;
3080        }
3081        if (c != '-')
3082                return 0;
3083        arg++;
3084        eq = strchr(arg, '=');
3085        if (eq)
3086                len = eq - arg;
3087        else
3088                len = strlen(arg);
3089        if (!len || strncmp(arg, arg_long, len))
3090                return 0;
3091        if (eq) {
3092                int n;
3093                char *end;
3094                if (!isdigit(*++eq))
3095                        return 0;
3096                n = strtoul(eq, &end, 10);
3097                if (*end)
3098                        return 0;
3099                *val = n;
3100        }
3101        return 1;
3102}
3103
3104static int diff_scoreopt_parse(const char *opt);
3105
3106static inline int short_opt(char opt, const char **argv,
3107                            const char **optarg)
3108{
3109        const char *arg = argv[0];
3110        if (arg[0] != '-' || arg[1] != opt)
3111                return 0;
3112        if (arg[2] != '\0') {
3113                *optarg = arg + 2;
3114                return 1;
3115        }
3116        if (!argv[1])
3117                die("Option '%c' requires a value", opt);
3118        *optarg = argv[1];
3119        return 2;
3120}
3121
3122int parse_long_opt(const char *opt, const char **argv,
3123                   const char **optarg)
3124{
3125        const char *arg = argv[0];
3126        if (arg[0] != '-' || arg[1] != '-')
3127                return 0;
3128        arg += strlen("--");
3129        if (prefixcmp(arg, opt))
3130                return 0;
3131        arg += strlen(opt);
3132        if (*arg == '=') { /* sticked form: --option=value */
3133                *optarg = arg + 1;
3134                return 1;
3135        }
3136        if (*arg != '\0')
3137                return 0;
3138        /* separate form: --option value */
3139        if (!argv[1])
3140                die("Option '--%s' requires a value", opt);
3141        *optarg = argv[1];
3142        return 2;
3143}
3144
3145static int stat_opt(struct diff_options *options, const char **av)
3146{
3147        const char *arg = av[0];
3148        char *end;
3149        int width = options->stat_width;
3150        int name_width = options->stat_name_width;
3151        int argcount = 1;
3152
3153        arg += strlen("--stat");
3154        end = (char *)arg;
3155
3156        switch (*arg) {
3157        case '-':
3158                if (!prefixcmp(arg, "-width")) {
3159                        arg += strlen("-width");
3160                        if (*arg == '=')
3161                                width = strtoul(arg + 1, &end, 10);
3162                        else if (!*arg && !av[1])
3163                                die("Option '--stat-width' requires a value");
3164                        else if (!*arg) {
3165                                width = strtoul(av[1], &end, 10);
3166                                argcount = 2;
3167                        }
3168                } else if (!prefixcmp(arg, "-name-width")) {
3169                        arg += strlen("-name-width");
3170                        if (*arg == '=')
3171                                name_width = strtoul(arg + 1, &end, 10);
3172                        else if (!*arg && !av[1])
3173                                die("Option '--stat-name-width' requires a value");
3174                        else if (!*arg) {
3175                                name_width = strtoul(av[1], &end, 10);
3176                                argcount = 2;
3177                        }
3178                }
3179                break;
3180        case '=':
3181                width = strtoul(arg+1, &end, 10);
3182                if (*end == ',')
3183                        name_width = strtoul(end+1, &end, 10);
3184        }
3185
3186        /* Important! This checks all the error cases! */
3187        if (*end)
3188                return 0;
3189        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3190        options->stat_name_width = name_width;
3191        options->stat_width = width;
3192        return argcount;
3193}
3194
3195static int parse_dirstat_opt(struct diff_options *options, const char *params)
3196{
3197        if (parse_dirstat_params(options, params))
3198                die("Failed to parse --dirstat/-X option parameter");
3199        /*
3200         * The caller knows a dirstat-related option is given from the command
3201         * line; allow it to say "return this_function();"
3202         */
3203        options->output_format |= DIFF_FORMAT_DIRSTAT;
3204        return 1;
3205}
3206
3207int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3208{
3209        const char *arg = av[0];
3210        const char *optarg;
3211        int argcount;
3212
3213        /* Output format options */
3214        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3215                options->output_format |= DIFF_FORMAT_PATCH;
3216        else if (opt_arg(arg, 'U', "unified", &options->context))
3217                options->output_format |= DIFF_FORMAT_PATCH;
3218        else if (!strcmp(arg, "--raw"))
3219                options->output_format |= DIFF_FORMAT_RAW;
3220        else if (!strcmp(arg, "--patch-with-raw"))
3221                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3222        else if (!strcmp(arg, "--numstat"))
3223                options->output_format |= DIFF_FORMAT_NUMSTAT;
3224        else if (!strcmp(arg, "--shortstat"))
3225                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3226        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3227                return parse_dirstat_opt(options, "");
3228        else if (!prefixcmp(arg, "-X"))
3229                return parse_dirstat_opt(options, arg + 2);
3230        else if (!prefixcmp(arg, "--dirstat="))
3231                return parse_dirstat_opt(options, arg + 10);
3232        else if (!strcmp(arg, "--cumulative"))
3233                return parse_dirstat_opt(options, "cumulative");
3234        else if (!strcmp(arg, "--dirstat-by-file"))
3235                return parse_dirstat_opt(options, "files");
3236        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3237                parse_dirstat_opt(options, "files");
3238                return parse_dirstat_opt(options, arg + 18);
3239        }
3240        else if (!strcmp(arg, "--check"))
3241                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3242        else if (!strcmp(arg, "--summary"))
3243                options->output_format |= DIFF_FORMAT_SUMMARY;
3244        else if (!strcmp(arg, "--patch-with-stat"))
3245                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3246        else if (!strcmp(arg, "--name-only"))
3247                options->output_format |= DIFF_FORMAT_NAME;
3248        else if (!strcmp(arg, "--name-status"))
3249                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3250        else if (!strcmp(arg, "-s"))
3251                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3252        else if (!prefixcmp(arg, "--stat"))
3253                /* --stat, --stat-width, or --stat-name-width */
3254                return stat_opt(options, av);
3255
3256        /* renames options */
3257        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3258                 !strcmp(arg, "--break-rewrites")) {
3259                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3260                        return error("invalid argument to -B: %s", arg+2);
3261        }
3262        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3263                 !strcmp(arg, "--find-renames")) {
3264                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3265                        return error("invalid argument to -M: %s", arg+2);
3266                options->detect_rename = DIFF_DETECT_RENAME;
3267        }
3268        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3269                options->irreversible_delete = 1;
3270        }
3271        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3272                 !strcmp(arg, "--find-copies")) {
3273                if (options->detect_rename == DIFF_DETECT_COPY)
3274                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3275                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3276                        return error("invalid argument to -C: %s", arg+2);
3277                options->detect_rename = DIFF_DETECT_COPY;
3278        }
3279        else if (!strcmp(arg, "--no-renames"))
3280                options->detect_rename = 0;
3281        else if (!strcmp(arg, "--relative"))
3282                DIFF_OPT_SET(options, RELATIVE_NAME);
3283        else if (!prefixcmp(arg, "--relative=")) {
3284                DIFF_OPT_SET(options, RELATIVE_NAME);
3285                options->prefix = arg + 11;
3286        }
3287
3288        /* xdiff options */
3289        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3290                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3291        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3292                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3293        else if (!strcmp(arg, "--ignore-space-at-eol"))
3294                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3295        else if (!strcmp(arg, "--patience"))
3296                DIFF_XDL_SET(options, PATIENCE_DIFF);
3297
3298        /* flags options */
3299        else if (!strcmp(arg, "--binary")) {
3300                options->output_format |= DIFF_FORMAT_PATCH;
3301                DIFF_OPT_SET(options, BINARY);
3302        }
3303        else if (!strcmp(arg, "--full-index"))
3304                DIFF_OPT_SET(options, FULL_INDEX);
3305        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3306                DIFF_OPT_SET(options, TEXT);
3307        else if (!strcmp(arg, "-R"))
3308                DIFF_OPT_SET(options, REVERSE_DIFF);
3309        else if (!strcmp(arg, "--find-copies-harder"))
3310                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3311        else if (!strcmp(arg, "--follow"))
3312                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3313        else if (!strcmp(arg, "--color"))
3314                DIFF_OPT_SET(options, COLOR_DIFF);
3315        else if (!prefixcmp(arg, "--color=")) {
3316                int value = git_config_colorbool(NULL, arg+8, -1);
3317                if (value == 0)
3318                        DIFF_OPT_CLR(options, COLOR_DIFF);
3319                else if (value > 0)
3320                        DIFF_OPT_SET(options, COLOR_DIFF);
3321                else
3322                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3323        }
3324        else if (!strcmp(arg, "--no-color"))
3325                DIFF_OPT_CLR(options, COLOR_DIFF);
3326        else if (!strcmp(arg, "--color-words")) {
3327                DIFF_OPT_SET(options, COLOR_DIFF);
3328                options->word_diff = DIFF_WORDS_COLOR;
3329        }
3330        else if (!prefixcmp(arg, "--color-words=")) {
3331                DIFF_OPT_SET(options, COLOR_DIFF);
3332                options->word_diff = DIFF_WORDS_COLOR;
3333                options->word_regex = arg + 14;
3334        }
3335        else if (!strcmp(arg, "--word-diff")) {
3336                if (options->word_diff == DIFF_WORDS_NONE)
3337                        options->word_diff = DIFF_WORDS_PLAIN;
3338        }
3339        else if (!prefixcmp(arg, "--word-diff=")) {
3340                const char *type = arg + 12;
3341                if (!strcmp(type, "plain"))
3342                        options->word_diff = DIFF_WORDS_PLAIN;
3343                else if (!strcmp(type, "color")) {
3344                        DIFF_OPT_SET(options, COLOR_DIFF);
3345                        options->word_diff = DIFF_WORDS_COLOR;
3346                }
3347                else if (!strcmp(type, "porcelain"))
3348                        options->word_diff = DIFF_WORDS_PORCELAIN;
3349                else if (!strcmp(type, "none"))
3350                        options->word_diff = DIFF_WORDS_NONE;
3351                else
3352                        die("bad --word-diff argument: %s", type);
3353        }
3354        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3355                if (options->word_diff == DIFF_WORDS_NONE)
3356                        options->word_diff = DIFF_WORDS_PLAIN;
3357                options->word_regex = optarg;
3358                return argcount;
3359        }
3360        else if (!strcmp(arg, "--exit-code"))
3361                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3362        else if (!strcmp(arg, "--quiet"))
3363                DIFF_OPT_SET(options, QUICK);
3364        else if (!strcmp(arg, "--ext-diff"))
3365                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3366        else if (!strcmp(arg, "--no-ext-diff"))
3367                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3368        else if (!strcmp(arg, "--textconv"))
3369                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3370        else if (!strcmp(arg, "--no-textconv"))
3371                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3372        else if (!strcmp(arg, "--ignore-submodules")) {
3373                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3374                handle_ignore_submodules_arg(options, "all");
3375        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3376                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3377                handle_ignore_submodules_arg(options, arg + 20);
3378        } else if (!strcmp(arg, "--submodule"))
3379                DIFF_OPT_SET(options, SUBMODULE_LOG);
3380        else if (!prefixcmp(arg, "--submodule=")) {
3381                if (!strcmp(arg + 12, "log"))
3382                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3383        }
3384
3385        /* misc options */
3386        else if (!strcmp(arg, "-z"))
3387                options->line_termination = 0;
3388        else if ((argcount = short_opt('l', av, &optarg))) {
3389                options->rename_limit = strtoul(optarg, NULL, 10);
3390                return argcount;
3391        }
3392        else if ((argcount = short_opt('S', av, &optarg))) {
3393                options->pickaxe = optarg;
3394                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3395                return argcount;
3396        } else if ((argcount = short_opt('G', av, &optarg))) {
3397                options->pickaxe = optarg;
3398                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3399                return argcount;
3400        }
3401        else if (!strcmp(arg, "--pickaxe-all"))
3402                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3403        else if (!strcmp(arg, "--pickaxe-regex"))
3404                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3405        else if ((argcount = short_opt('O', av, &optarg))) {
3406                options->orderfile = optarg;
3407                return argcount;
3408        }
3409        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3410                options->filter = optarg;
3411                return argcount;
3412        }
3413        else if (!strcmp(arg, "--abbrev"))
3414                options->abbrev = DEFAULT_ABBREV;
3415        else if (!prefixcmp(arg, "--abbrev=")) {
3416                options->abbrev = strtoul(arg + 9, NULL, 10);
3417                if (options->abbrev < MINIMUM_ABBREV)
3418                        options->abbrev = MINIMUM_ABBREV;
3419                else if (40 < options->abbrev)
3420                        options->abbrev = 40;
3421        }
3422        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3423                options->a_prefix = optarg;
3424                return argcount;
3425        }
3426        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3427                options->b_prefix = optarg;
3428                return argcount;
3429        }
3430        else if (!strcmp(arg, "--no-prefix"))
3431                options->a_prefix = options->b_prefix = "";
3432        else if (opt_arg(arg, '\0', "inter-hunk-context",
3433                         &options->interhunkcontext))
3434                ;
3435        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3436                options->file = fopen(optarg, "w");
3437                if (!options->file)
3438                        die_errno("Could not open '%s'", optarg);
3439                options->close_file = 1;
3440                return argcount;
3441        } else
3442                return 0;
3443        return 1;
3444}
3445
3446int parse_rename_score(const char **cp_p)
3447{
3448        unsigned long num, scale;
3449        int ch, dot;
3450        const char *cp = *cp_p;
3451
3452        num = 0;
3453        scale = 1;
3454        dot = 0;
3455        for (;;) {
3456                ch = *cp;
3457                if ( !dot && ch == '.' ) {
3458                        scale = 1;
3459                        dot = 1;
3460                } else if ( ch == '%' ) {
3461                        scale = dot ? scale*100 : 100;
3462                        cp++;   /* % is always at the end */
3463                        break;
3464                } else if ( ch >= '0' && ch <= '9' ) {
3465                        if ( scale < 100000 ) {
3466                                scale *= 10;
3467                                num = (num*10) + (ch-'0');
3468                        }
3469                } else {
3470                        break;
3471                }
3472                cp++;
3473        }
3474        *cp_p = cp;
3475
3476        /* user says num divided by scale and we say internally that
3477         * is MAX_SCORE * num / scale.
3478         */
3479        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3480}
3481
3482static int diff_scoreopt_parse(const char *opt)
3483{
3484        int opt1, opt2, cmd;
3485
3486        if (*opt++ != '-')
3487                return -1;
3488        cmd = *opt++;
3489        if (cmd == '-') {
3490                /* convert the long-form arguments into short-form versions */
3491                if (!prefixcmp(opt, "break-rewrites")) {
3492                        opt += strlen("break-rewrites");
3493                        if (*opt == 0 || *opt++ == '=')
3494                                cmd = 'B';
3495                } else if (!prefixcmp(opt, "find-copies")) {
3496                        opt += strlen("find-copies");
3497                        if (*opt == 0 || *opt++ == '=')
3498                                cmd = 'C';
3499                } else if (!prefixcmp(opt, "find-renames")) {
3500                        opt += strlen("find-renames");
3501                        if (*opt == 0 || *opt++ == '=')
3502                                cmd = 'M';
3503                }
3504        }
3505        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3506                return -1; /* that is not a -M, -C nor -B option */
3507
3508        opt1 = parse_rename_score(&opt);
3509        if (cmd != 'B')
3510                opt2 = 0;
3511        else {
3512                if (*opt == 0)
3513                        opt2 = 0;
3514                else if (*opt != '/')
3515                        return -1; /* we expect -B80/99 or -B80 */
3516                else {
3517                        opt++;
3518                        opt2 = parse_rename_score(&opt);
3519                }
3520        }
3521        if (*opt != 0)
3522                return -1;
3523        return opt1 | (opt2 << 16);
3524}
3525
3526struct diff_queue_struct diff_queued_diff;
3527
3528void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3529{
3530        if (queue->alloc <= queue->nr) {
3531                queue->alloc = alloc_nr(queue->alloc);
3532                queue->queue = xrealloc(queue->queue,
3533                                        sizeof(dp) * queue->alloc);
3534        }
3535        queue->queue[queue->nr++] = dp;
3536}
3537
3538struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3539                                 struct diff_filespec *one,
3540                                 struct diff_filespec *two)
3541{
3542        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3543        dp->one = one;
3544        dp->two = two;
3545        if (queue)
3546                diff_q(queue, dp);
3547        return dp;
3548}
3549
3550void diff_free_filepair(struct diff_filepair *p)
3551{
3552        free_filespec(p->one);
3553        free_filespec(p->two);
3554        free(p);
3555}
3556
3557/* This is different from find_unique_abbrev() in that
3558 * it stuffs the result with dots for alignment.
3559 */
3560const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3561{
3562        int abblen;
3563        const char *abbrev;
3564        if (len == 40)
3565                return sha1_to_hex(sha1);
3566
3567        abbrev = find_unique_abbrev(sha1, len);
3568        abblen = strlen(abbrev);
3569        if (abblen < 37) {
3570                static char hex[41];
3571                if (len < abblen && abblen <= len + 2)
3572                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3573                else
3574                        sprintf(hex, "%s...", abbrev);
3575                return hex;
3576        }
3577        return sha1_to_hex(sha1);
3578}
3579
3580static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3581{
3582        int line_termination = opt->line_termination;
3583        int inter_name_termination = line_termination ? '\t' : '\0';
3584        if (opt->output_prefix) {
3585                struct strbuf *msg = NULL;
3586                msg = opt->output_prefix(opt, opt->output_prefix_data);
3587                fprintf(opt->file, "%s", msg->buf);
3588        }
3589
3590        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3591                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3592                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3593                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3594        }
3595        if (p->score) {
3596                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3597                        inter_name_termination);
3598        } else {
3599                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3600        }
3601
3602        if (p->status == DIFF_STATUS_COPIED ||
3603            p->status == DIFF_STATUS_RENAMED) {
3604                const char *name_a, *name_b;
3605                name_a = p->one->path;
3606                name_b = p->two->path;
3607                strip_prefix(opt->prefix_length, &name_a, &name_b);
3608                write_name_quoted(name_a, opt->file, inter_name_termination);
3609                write_name_quoted(name_b, opt->file, line_termination);
3610        } else {
3611                const char *name_a, *name_b;
3612                name_a = p->one->mode ? p->one->path : p->two->path;
3613                name_b = NULL;
3614                strip_prefix(opt->prefix_length, &name_a, &name_b);
3615                write_name_quoted(name_a, opt->file, line_termination);
3616        }
3617}
3618
3619int diff_unmodified_pair(struct diff_filepair *p)
3620{
3621        /* This function is written stricter than necessary to support
3622         * the currently implemented transformers, but the idea is to
3623         * let transformers to produce diff_filepairs any way they want,
3624         * and filter and clean them up here before producing the output.
3625         */
3626        struct diff_filespec *one = p->one, *two = p->two;
3627
3628        if (DIFF_PAIR_UNMERGED(p))
3629                return 0; /* unmerged is interesting */
3630
3631        /* deletion, addition, mode or type change
3632         * and rename are all interesting.
3633         */
3634        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3635            DIFF_PAIR_MODE_CHANGED(p) ||
3636            strcmp(one->path, two->path))
3637                return 0;
3638
3639        /* both are valid and point at the same path.  that is, we are
3640         * dealing with a change.
3641         */
3642        if (one->sha1_valid && two->sha1_valid &&
3643            !hashcmp(one->sha1, two->sha1) &&
3644            !one->dirty_submodule && !two->dirty_submodule)
3645                return 1; /* no change */
3646        if (!one->sha1_valid && !two->sha1_valid)
3647                return 1; /* both look at the same file on the filesystem. */
3648        return 0;
3649}
3650
3651static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3652{
3653        if (diff_unmodified_pair(p))
3654                return;
3655
3656        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3657            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3658                return; /* no tree diffs in patch format */
3659
3660        run_diff(p, o);
3661}
3662
3663static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3664                            struct diffstat_t *diffstat)
3665{
3666        if (diff_unmodified_pair(p))
3667                return;
3668
3669        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3670            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3671                return; /* no useful stat for tree diffs */
3672
3673        run_diffstat(p, o, diffstat);
3674}
3675
3676static void diff_flush_checkdiff(struct diff_filepair *p,
3677                struct diff_options *o)
3678{
3679        if (diff_unmodified_pair(p))
3680                return;
3681
3682        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3683            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3684                return; /* nothing to check in tree diffs */
3685
3686        run_checkdiff(p, o);
3687}
3688
3689int diff_queue_is_empty(void)
3690{
3691        struct diff_queue_struct *q = &diff_queued_diff;
3692        int i;
3693        for (i = 0; i < q->nr; i++)
3694                if (!diff_unmodified_pair(q->queue[i]))
3695                        return 0;
3696        return 1;
3697}
3698
3699#if DIFF_DEBUG
3700void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3701{
3702        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3703                x, one ? one : "",
3704                s->path,
3705                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3706                s->mode,
3707                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3708        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3709                x, one ? one : "",
3710                s->size, s->xfrm_flags);
3711}
3712
3713void diff_debug_filepair(const struct diff_filepair *p, int i)
3714{
3715        diff_debug_filespec(p->one, i, "one");
3716        diff_debug_filespec(p->two, i, "two");
3717        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3718                p->score, p->status ? p->status : '?',
3719                p->one->rename_used, p->broken_pair);
3720}
3721
3722void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3723{
3724        int i;
3725        if (msg)
3726                fprintf(stderr, "%s\n", msg);
3727        fprintf(stderr, "q->nr = %d\n", q->nr);
3728        for (i = 0; i < q->nr; i++) {
3729                struct diff_filepair *p = q->queue[i];
3730                diff_debug_filepair(p, i);
3731        }
3732}
3733#endif
3734
3735static void diff_resolve_rename_copy(void)
3736{
3737        int i;
3738        struct diff_filepair *p;
3739        struct diff_queue_struct *q = &diff_queued_diff;
3740
3741        diff_debug_queue("resolve-rename-copy", q);
3742
3743        for (i = 0; i < q->nr; i++) {
3744                p = q->queue[i];
3745                p->status = 0; /* undecided */
3746                if (DIFF_PAIR_UNMERGED(p))
3747                        p->status = DIFF_STATUS_UNMERGED;
3748                else if (!DIFF_FILE_VALID(p->one))
3749                        p->status = DIFF_STATUS_ADDED;
3750                else if (!DIFF_FILE_VALID(p->two))
3751                        p->status = DIFF_STATUS_DELETED;
3752                else if (DIFF_PAIR_TYPE_CHANGED(p))
3753                        p->status = DIFF_STATUS_TYPE_CHANGED;
3754
3755                /* from this point on, we are dealing with a pair
3756                 * whose both sides are valid and of the same type, i.e.
3757                 * either in-place edit or rename/copy edit.
3758                 */
3759                else if (DIFF_PAIR_RENAME(p)) {
3760                        /*
3761                         * A rename might have re-connected a broken
3762                         * pair up, causing the pathnames to be the
3763                         * same again. If so, that's not a rename at
3764                         * all, just a modification..
3765                         *
3766                         * Otherwise, see if this source was used for
3767                         * multiple renames, in which case we decrement
3768                         * the count, and call it a copy.
3769                         */
3770                        if (!strcmp(p->one->path, p->two->path))
3771                                p->status = DIFF_STATUS_MODIFIED;
3772                        else if (--p->one->rename_used > 0)
3773                                p->status = DIFF_STATUS_COPIED;
3774                        else
3775                                p->status = DIFF_STATUS_RENAMED;
3776                }
3777                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3778                         p->one->mode != p->two->mode ||
3779                         p->one->dirty_submodule ||
3780                         p->two->dirty_submodule ||
3781                         is_null_sha1(p->one->sha1))
3782                        p->status = DIFF_STATUS_MODIFIED;
3783                else {
3784                        /* This is a "no-change" entry and should not
3785                         * happen anymore, but prepare for broken callers.
3786                         */
3787                        error("feeding unmodified %s to diffcore",
3788                              p->one->path);
3789                        p->status = DIFF_STATUS_UNKNOWN;
3790                }
3791        }
3792        diff_debug_queue("resolve-rename-copy done", q);
3793}
3794
3795static int check_pair_status(struct diff_filepair *p)
3796{
3797        switch (p->status) {
3798        case DIFF_STATUS_UNKNOWN:
3799                return 0;
3800        case 0:
3801                die("internal error in diff-resolve-rename-copy");
3802        default:
3803                return 1;
3804        }
3805}
3806
3807static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3808{
3809        int fmt = opt->output_format;
3810
3811        if (fmt & DIFF_FORMAT_CHECKDIFF)
3812                diff_flush_checkdiff(p, opt);
3813        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3814                diff_flush_raw(p, opt);
3815        else if (fmt & DIFF_FORMAT_NAME) {
3816                const char *name_a, *name_b;
3817                name_a = p->two->path;
3818                name_b = NULL;
3819                strip_prefix(opt->prefix_length, &name_a, &name_b);
3820                write_name_quoted(name_a, opt->file, opt->line_termination);
3821        }
3822}
3823
3824static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3825{
3826        if (fs->mode)
3827                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3828        else
3829                fprintf(file, " %s ", newdelete);
3830        write_name_quoted(fs->path, file, '\n');
3831}
3832
3833
3834static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3835                const char *line_prefix)
3836{
3837        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3838                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3839                        p->two->mode, show_name ? ' ' : '\n');
3840                if (show_name) {
3841                        write_name_quoted(p->two->path, file, '\n');
3842                }
3843        }
3844}
3845
3846static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3847                        const char *line_prefix)
3848{
3849        char *names = pprint_rename(p->one->path, p->two->path);
3850
3851        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3852        free(names);
3853        show_mode_change(file, p, 0, line_prefix);
3854}
3855
3856static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3857{
3858        FILE *file = opt->file;
3859        char *line_prefix = "";
3860
3861        if (opt->output_prefix) {
3862                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3863                line_prefix = buf->buf;
3864        }
3865
3866        switch(p->status) {
3867        case DIFF_STATUS_DELETED:
3868                fputs(line_prefix, file);
3869                show_file_mode_name(file, "delete", p->one);
3870                break;
3871        case DIFF_STATUS_ADDED:
3872                fputs(line_prefix, file);
3873                show_file_mode_name(file, "create", p->two);
3874                break;
3875        case DIFF_STATUS_COPIED:
3876                fputs(line_prefix, file);
3877                show_rename_copy(file, "copy", p, line_prefix);
3878                break;
3879        case DIFF_STATUS_RENAMED:
3880                fputs(line_prefix, file);
3881                show_rename_copy(file, "rename", p, line_prefix);
3882                break;
3883        default:
3884                if (p->score) {
3885                        fprintf(file, "%s rewrite ", line_prefix);
3886                        write_name_quoted(p->two->path, file, ' ');
3887                        fprintf(file, "(%d%%)\n", similarity_index(p));
3888                }
3889                show_mode_change(file, p, !p->score, line_prefix);
3890                break;
3891        }
3892}
3893
3894struct patch_id_t {
3895        git_SHA_CTX *ctx;
3896        int patchlen;
3897};
3898
3899static int remove_space(char *line, int len)
3900{
3901        int i;
3902        char *dst = line;
3903        unsigned char c;
3904
3905        for (i = 0; i < len; i++)
3906                if (!isspace((c = line[i])))
3907                        *dst++ = c;
3908
3909        return dst - line;
3910}
3911
3912static void patch_id_consume(void *priv, char *line, unsigned long len)
3913{
3914        struct patch_id_t *data = priv;
3915        int new_len;
3916
3917        /* Ignore line numbers when computing the SHA1 of the patch */
3918        if (!prefixcmp(line, "@@ -"))
3919                return;
3920
3921        new_len = remove_space(line, len);
3922
3923        git_SHA1_Update(data->ctx, line, new_len);
3924        data->patchlen += new_len;
3925}
3926
3927/* returns 0 upon success, and writes result into sha1 */
3928static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3929{
3930        struct diff_queue_struct *q = &diff_queued_diff;
3931        int i;
3932        git_SHA_CTX ctx;
3933        struct patch_id_t data;
3934        char buffer[PATH_MAX * 4 + 20];
3935
3936        git_SHA1_Init(&ctx);
3937        memset(&data, 0, sizeof(struct patch_id_t));
3938        data.ctx = &ctx;
3939
3940        for (i = 0; i < q->nr; i++) {
3941                xpparam_t xpp;
3942                xdemitconf_t xecfg;
3943                mmfile_t mf1, mf2;
3944                struct diff_filepair *p = q->queue[i];
3945                int len1, len2;
3946
3947                memset(&xpp, 0, sizeof(xpp));
3948                memset(&xecfg, 0, sizeof(xecfg));
3949                if (p->status == 0)
3950                        return error("internal diff status error");
3951                if (p->status == DIFF_STATUS_UNKNOWN)
3952                        continue;
3953                if (diff_unmodified_pair(p))
3954                        continue;
3955                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3956                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3957                        continue;
3958                if (DIFF_PAIR_UNMERGED(p))
3959                        continue;
3960
3961                diff_fill_sha1_info(p->one);
3962                diff_fill_sha1_info(p->two);
3963                if (fill_mmfile(&mf1, p->one) < 0 ||
3964                                fill_mmfile(&mf2, p->two) < 0)
3965                        return error("unable to read files to diff");
3966
3967                len1 = remove_space(p->one->path, strlen(p->one->path));
3968                len2 = remove_space(p->two->path, strlen(p->two->path));
3969                if (p->one->mode == 0)
3970                        len1 = snprintf(buffer, sizeof(buffer),
3971                                        "diff--gita/%.*sb/%.*s"
3972                                        "newfilemode%06o"
3973                                        "---/dev/null"
3974                                        "+++b/%.*s",
3975                                        len1, p->one->path,
3976                                        len2, p->two->path,
3977                                        p->two->mode,
3978                                        len2, p->two->path);
3979                else if (p->two->mode == 0)
3980                        len1 = snprintf(buffer, sizeof(buffer),
3981                                        "diff--gita/%.*sb/%.*s"
3982                                        "deletedfilemode%06o"
3983                                        "---a/%.*s"
3984                                        "+++/dev/null",
3985                                        len1, p->one->path,
3986                                        len2, p->two->path,
3987                                        p->one->mode,
3988                                        len1, p->one->path);
3989                else
3990                        len1 = snprintf(buffer, sizeof(buffer),
3991                                        "diff--gita/%.*sb/%.*s"
3992                                        "---a/%.*s"
3993                                        "+++b/%.*s",
3994                                        len1, p->one->path,
3995                                        len2, p->two->path,
3996                                        len1, p->one->path,
3997                                        len2, p->two->path);
3998                git_SHA1_Update(&ctx, buffer, len1);
3999
4000                if (diff_filespec_is_binary(p->one) ||
4001                    diff_filespec_is_binary(p->two)) {
4002                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4003                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4004                        continue;
4005                }
4006
4007                xpp.flags = 0;
4008                xecfg.ctxlen = 3;
4009                xecfg.flags = 0;
4010                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4011                              &xpp, &xecfg);
4012        }
4013
4014        git_SHA1_Final(sha1, &ctx);
4015        return 0;
4016}
4017
4018int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4019{
4020        struct diff_queue_struct *q = &diff_queued_diff;
4021        int i;
4022        int result = diff_get_patch_id(options, sha1);
4023
4024        for (i = 0; i < q->nr; i++)
4025                diff_free_filepair(q->queue[i]);
4026
4027        free(q->queue);
4028        DIFF_QUEUE_CLEAR(q);
4029
4030        return result;
4031}
4032
4033static int is_summary_empty(const struct diff_queue_struct *q)
4034{
4035        int i;
4036
4037        for (i = 0; i < q->nr; i++) {
4038                const struct diff_filepair *p = q->queue[i];
4039
4040                switch (p->status) {
4041                case DIFF_STATUS_DELETED:
4042                case DIFF_STATUS_ADDED:
4043                case DIFF_STATUS_COPIED:
4044                case DIFF_STATUS_RENAMED:
4045                        return 0;
4046                default:
4047                        if (p->score)
4048                                return 0;
4049                        if (p->one->mode && p->two->mode &&
4050                            p->one->mode != p->two->mode)
4051                                return 0;
4052                        break;
4053                }
4054        }
4055        return 1;
4056}
4057
4058static const char rename_limit_warning[] =
4059"inexact rename detection was skipped due to too many files.";
4060
4061static const char degrade_cc_to_c_warning[] =
4062"only found copies from modified paths due to too many files.";
4063
4064static const char rename_limit_advice[] =
4065"you may want to set your %s variable to at least "
4066"%d and retry the command.";
4067
4068void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4069{
4070        if (degraded_cc)
4071                warning(degrade_cc_to_c_warning);
4072        else if (needed)
4073                warning(rename_limit_warning);
4074        else
4075                return;
4076        if (0 < needed && needed < 32767)
4077                warning(rename_limit_advice, varname, needed);
4078}
4079
4080void diff_flush(struct diff_options *options)
4081{
4082        struct diff_queue_struct *q = &diff_queued_diff;
4083        int i, output_format = options->output_format;
4084        int separator = 0;
4085
4086        /*
4087         * Order: raw, stat, summary, patch
4088         * or:    name/name-status/checkdiff (other bits clear)
4089         */
4090        if (!q->nr)
4091                goto free_queue;
4092
4093        if (output_format & (DIFF_FORMAT_RAW |
4094                             DIFF_FORMAT_NAME |
4095                             DIFF_FORMAT_NAME_STATUS |
4096                             DIFF_FORMAT_CHECKDIFF)) {
4097                for (i = 0; i < q->nr; i++) {
4098                        struct diff_filepair *p = q->queue[i];
4099                        if (check_pair_status(p))
4100                                flush_one_pair(p, options);
4101                }
4102                separator++;
4103        }
4104
4105        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4106                struct diffstat_t diffstat;
4107
4108                memset(&diffstat, 0, sizeof(struct diffstat_t));
4109                for (i = 0; i < q->nr; i++) {
4110                        struct diff_filepair *p = q->queue[i];
4111                        if (check_pair_status(p))
4112                                diff_flush_stat(p, options, &diffstat);
4113                }
4114                if (output_format & DIFF_FORMAT_NUMSTAT)
4115                        show_numstat(&diffstat, options);
4116                if (output_format & DIFF_FORMAT_DIFFSTAT)
4117                        show_stats(&diffstat, options);
4118                if (output_format & DIFF_FORMAT_SHORTSTAT)
4119                        show_shortstats(&diffstat, options);
4120                free_diffstat_info(&diffstat);
4121                separator++;
4122        }
4123        if (output_format & DIFF_FORMAT_DIRSTAT)
4124                show_dirstat(options);
4125
4126        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4127                for (i = 0; i < q->nr; i++) {
4128                        diff_summary(options, q->queue[i]);
4129                }
4130                separator++;
4131        }
4132
4133        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4134            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4135            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4136                /*
4137                 * run diff_flush_patch for the exit status. setting
4138                 * options->file to /dev/null should be safe, becaue we
4139                 * aren't supposed to produce any output anyway.
4140                 */
4141                if (options->close_file)
4142                        fclose(options->file);
4143                options->file = fopen("/dev/null", "w");
4144                if (!options->file)
4145                        die_errno("Could not open /dev/null");
4146                options->close_file = 1;
4147                for (i = 0; i < q->nr; i++) {
4148                        struct diff_filepair *p = q->queue[i];
4149                        if (check_pair_status(p))
4150                                diff_flush_patch(p, options);
4151                        if (options->found_changes)
4152                                break;
4153                }
4154        }
4155
4156        if (output_format & DIFF_FORMAT_PATCH) {
4157                if (separator) {
4158                        putc(options->line_termination, options->file);
4159                        if (options->stat_sep) {
4160                                /* attach patch instead of inline */
4161                                fputs(options->stat_sep, options->file);
4162                        }
4163                }
4164
4165                for (i = 0; i < q->nr; i++) {
4166                        struct diff_filepair *p = q->queue[i];
4167                        if (check_pair_status(p))
4168                                diff_flush_patch(p, options);
4169                }
4170        }
4171
4172        if (output_format & DIFF_FORMAT_CALLBACK)
4173                options->format_callback(q, options, options->format_callback_data);
4174
4175        for (i = 0; i < q->nr; i++)
4176                diff_free_filepair(q->queue[i]);
4177free_queue:
4178        free(q->queue);
4179        DIFF_QUEUE_CLEAR(q);
4180        if (options->close_file)
4181                fclose(options->file);
4182
4183        /*
4184         * Report the content-level differences with HAS_CHANGES;
4185         * diff_addremove/diff_change does not set the bit when
4186         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4187         */
4188        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4189                if (options->found_changes)
4190                        DIFF_OPT_SET(options, HAS_CHANGES);
4191                else
4192                        DIFF_OPT_CLR(options, HAS_CHANGES);
4193        }
4194}
4195
4196static void diffcore_apply_filter(const char *filter)
4197{
4198        int i;
4199        struct diff_queue_struct *q = &diff_queued_diff;
4200        struct diff_queue_struct outq;
4201        DIFF_QUEUE_CLEAR(&outq);
4202
4203        if (!filter)
4204                return;
4205
4206        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4207                int found;
4208                for (i = found = 0; !found && i < q->nr; i++) {
4209                        struct diff_filepair *p = q->queue[i];
4210                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4211                             ((p->score &&
4212                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4213                              (!p->score &&
4214                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4215                            ((p->status != DIFF_STATUS_MODIFIED) &&
4216                             strchr(filter, p->status)))
4217                                found++;
4218                }
4219                if (found)
4220                        return;
4221
4222                /* otherwise we will clear the whole queue
4223                 * by copying the empty outq at the end of this
4224                 * function, but first clear the current entries
4225                 * in the queue.
4226                 */
4227                for (i = 0; i < q->nr; i++)
4228                        diff_free_filepair(q->queue[i]);
4229        }
4230        else {
4231                /* Only the matching ones */
4232                for (i = 0; i < q->nr; i++) {
4233                        struct diff_filepair *p = q->queue[i];
4234
4235                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4236                             ((p->score &&
4237                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4238                              (!p->score &&
4239                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4240                            ((p->status != DIFF_STATUS_MODIFIED) &&
4241                             strchr(filter, p->status)))
4242                                diff_q(&outq, p);
4243                        else
4244                                diff_free_filepair(p);
4245                }
4246        }
4247        free(q->queue);
4248        *q = outq;
4249}
4250
4251/* Check whether two filespecs with the same mode and size are identical */
4252static int diff_filespec_is_identical(struct diff_filespec *one,
4253                                      struct diff_filespec *two)
4254{
4255        if (S_ISGITLINK(one->mode))
4256                return 0;
4257        if (diff_populate_filespec(one, 0))
4258                return 0;
4259        if (diff_populate_filespec(two, 0))
4260                return 0;
4261        return !memcmp(one->data, two->data, one->size);
4262}
4263
4264static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4265{
4266        int i;
4267        struct diff_queue_struct *q = &diff_queued_diff;
4268        struct diff_queue_struct outq;
4269        DIFF_QUEUE_CLEAR(&outq);
4270
4271        for (i = 0; i < q->nr; i++) {
4272                struct diff_filepair *p = q->queue[i];
4273
4274                /*
4275                 * 1. Entries that come from stat info dirtiness
4276                 *    always have both sides (iow, not create/delete),
4277                 *    one side of the object name is unknown, with
4278                 *    the same mode and size.  Keep the ones that
4279                 *    do not match these criteria.  They have real
4280                 *    differences.
4281                 *
4282                 * 2. At this point, the file is known to be modified,
4283                 *    with the same mode and size, and the object
4284                 *    name of one side is unknown.  Need to inspect
4285                 *    the identical contents.
4286                 */
4287                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4288                    !DIFF_FILE_VALID(p->two) ||
4289                    (p->one->sha1_valid && p->two->sha1_valid) ||
4290                    (p->one->mode != p->two->mode) ||
4291                    diff_populate_filespec(p->one, 1) ||
4292                    diff_populate_filespec(p->two, 1) ||
4293                    (p->one->size != p->two->size) ||
4294                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4295                        diff_q(&outq, p);
4296                else {
4297                        /*
4298                         * The caller can subtract 1 from skip_stat_unmatch
4299                         * to determine how many paths were dirty only
4300                         * due to stat info mismatch.
4301                         */
4302                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4303                                diffopt->skip_stat_unmatch++;
4304                        diff_free_filepair(p);
4305                }
4306        }
4307        free(q->queue);
4308        *q = outq;
4309}
4310
4311static int diffnamecmp(const void *a_, const void *b_)
4312{
4313        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4314        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4315        const char *name_a, *name_b;
4316
4317        name_a = a->one ? a->one->path : a->two->path;
4318        name_b = b->one ? b->one->path : b->two->path;
4319        return strcmp(name_a, name_b);
4320}
4321
4322void diffcore_fix_diff_index(struct diff_options *options)
4323{
4324        struct diff_queue_struct *q = &diff_queued_diff;
4325        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4326}
4327
4328void diffcore_std(struct diff_options *options)
4329{
4330        if (options->skip_stat_unmatch)
4331                diffcore_skip_stat_unmatch(options);
4332        if (!options->found_follow) {
4333                /* See try_to_follow_renames() in tree-diff.c */
4334                if (options->break_opt != -1)
4335                        diffcore_break(options->break_opt);
4336                if (options->detect_rename)
4337                        diffcore_rename(options);
4338                if (options->break_opt != -1)
4339                        diffcore_merge_broken();
4340        }
4341        if (options->pickaxe)
4342                diffcore_pickaxe(options);
4343        if (options->orderfile)
4344                diffcore_order(options->orderfile);
4345        if (!options->found_follow)
4346                /* See try_to_follow_renames() in tree-diff.c */
4347                diff_resolve_rename_copy();
4348        diffcore_apply_filter(options->filter);
4349
4350        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4351                DIFF_OPT_SET(options, HAS_CHANGES);
4352        else
4353                DIFF_OPT_CLR(options, HAS_CHANGES);
4354
4355        options->found_follow = 0;
4356}
4357
4358int diff_result_code(struct diff_options *opt, int status)
4359{
4360        int result = 0;
4361
4362        diff_warn_rename_limit("diff.renamelimit",
4363                               opt->needed_rename_limit,
4364                               opt->degraded_cc_to_c);
4365        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4366            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4367                return status;
4368        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4369            DIFF_OPT_TST(opt, HAS_CHANGES))
4370                result |= 01;
4371        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4372            DIFF_OPT_TST(opt, CHECK_FAILED))
4373                result |= 02;
4374        return result;
4375}
4376
4377/*
4378 * Shall changes to this submodule be ignored?
4379 *
4380 * Submodule changes can be configured to be ignored separately for each path,
4381 * but that configuration can be overridden from the command line.
4382 */
4383static int is_submodule_ignored(const char *path, struct diff_options *options)
4384{
4385        int ignored = 0;
4386        unsigned orig_flags = options->flags;
4387        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4388                set_diffopt_flags_from_submodule_config(options, path);
4389        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4390                ignored = 1;
4391        options->flags = orig_flags;
4392        return ignored;
4393}
4394
4395void diff_addremove(struct diff_options *options,
4396                    int addremove, unsigned mode,
4397                    const unsigned char *sha1,
4398                    const char *concatpath, unsigned dirty_submodule)
4399{
4400        struct diff_filespec *one, *two;
4401
4402        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4403                return;
4404
4405        /* This may look odd, but it is a preparation for
4406         * feeding "there are unchanged files which should
4407         * not produce diffs, but when you are doing copy
4408         * detection you would need them, so here they are"
4409         * entries to the diff-core.  They will be prefixed
4410         * with something like '=' or '*' (I haven't decided
4411         * which but should not make any difference).
4412         * Feeding the same new and old to diff_change()
4413         * also has the same effect.
4414         * Before the final output happens, they are pruned after
4415         * merged into rename/copy pairs as appropriate.
4416         */
4417        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4418                addremove = (addremove == '+' ? '-' :
4419                             addremove == '-' ? '+' : addremove);
4420
4421        if (options->prefix &&
4422            strncmp(concatpath, options->prefix, options->prefix_length))
4423                return;
4424
4425        one = alloc_filespec(concatpath);
4426        two = alloc_filespec(concatpath);
4427
4428        if (addremove != '+')
4429                fill_filespec(one, sha1, mode);
4430        if (addremove != '-') {
4431                fill_filespec(two, sha1, mode);
4432                two->dirty_submodule = dirty_submodule;
4433        }
4434
4435        diff_queue(&diff_queued_diff, one, two);
4436        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4437                DIFF_OPT_SET(options, HAS_CHANGES);
4438}
4439
4440void diff_change(struct diff_options *options,
4441                 unsigned old_mode, unsigned new_mode,
4442                 const unsigned char *old_sha1,
4443                 const unsigned char *new_sha1,
4444                 const char *concatpath,
4445                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4446{
4447        struct diff_filespec *one, *two;
4448
4449        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4450            is_submodule_ignored(concatpath, options))
4451                return;
4452
4453        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4454                unsigned tmp;
4455                const unsigned char *tmp_c;
4456                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4457                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4458                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4459                        new_dirty_submodule = tmp;
4460        }
4461
4462        if (options->prefix &&
4463            strncmp(concatpath, options->prefix, options->prefix_length))
4464                return;
4465
4466        one = alloc_filespec(concatpath);
4467        two = alloc_filespec(concatpath);
4468        fill_filespec(one, old_sha1, old_mode);
4469        fill_filespec(two, new_sha1, new_mode);
4470        one->dirty_submodule = old_dirty_submodule;
4471        two->dirty_submodule = new_dirty_submodule;
4472
4473        diff_queue(&diff_queued_diff, one, two);
4474        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4475                DIFF_OPT_SET(options, HAS_CHANGES);
4476}
4477
4478void diff_unmerge(struct diff_options *options,
4479                  const char *path,
4480                  unsigned mode, const unsigned char *sha1)
4481{
4482        struct diff_filespec *one, *two;
4483
4484        if (options->prefix &&
4485            strncmp(path, options->prefix, options->prefix_length))
4486                return;
4487
4488        one = alloc_filespec(path);
4489        two = alloc_filespec(path);
4490        fill_filespec(one, sha1, mode);
4491        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4492}
4493
4494static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4495                size_t *outsize)
4496{
4497        struct diff_tempfile *temp;
4498        const char *argv[3];
4499        const char **arg = argv;
4500        struct child_process child;
4501        struct strbuf buf = STRBUF_INIT;
4502        int err = 0;
4503
4504        temp = prepare_temp_file(spec->path, spec);
4505        *arg++ = pgm;
4506        *arg++ = temp->name;
4507        *arg = NULL;
4508
4509        memset(&child, 0, sizeof(child));
4510        child.use_shell = 1;
4511        child.argv = argv;
4512        child.out = -1;
4513        if (start_command(&child)) {
4514                remove_tempfile();
4515                return NULL;
4516        }
4517
4518        if (strbuf_read(&buf, child.out, 0) < 0)
4519                err = error("error reading from textconv command '%s'", pgm);
4520        close(child.out);
4521
4522        if (finish_command(&child) || err) {
4523                strbuf_release(&buf);
4524                remove_tempfile();
4525                return NULL;
4526        }
4527        remove_tempfile();
4528
4529        return strbuf_detach(&buf, outsize);
4530}
4531
4532size_t fill_textconv(struct userdiff_driver *driver,
4533                     struct diff_filespec *df,
4534                     char **outbuf)
4535{
4536        size_t size;
4537
4538        if (!driver || !driver->textconv) {
4539                if (!DIFF_FILE_VALID(df)) {
4540                        *outbuf = "";
4541                        return 0;
4542                }
4543                if (diff_populate_filespec(df, 0))
4544                        die("unable to read files to diff");
4545                *outbuf = df->data;
4546                return df->size;
4547        }
4548
4549        if (driver->textconv_cache && df->sha1_valid) {
4550                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4551                                          &size);
4552                if (*outbuf)
4553                        return size;
4554        }
4555
4556        *outbuf = run_textconv(driver->textconv, df, &size);
4557        if (!*outbuf)
4558                die("unable to read files to diff");
4559
4560        if (driver->textconv_cache && df->sha1_valid) {
4561                /* ignore errors, as we might be in a readonly repository */
4562                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4563                                size);
4564                /*
4565                 * we could save up changes and flush them all at the end,
4566                 * but we would need an extra call after all diffing is done.
4567                 * Since generating a cache entry is the slow path anyway,
4568                 * this extra overhead probably isn't a big deal.
4569                 */
4570                notes_cache_write(driver->textconv_cache);
4571        }
4572
4573        return size;
4574}