3b0cda43f16ccf844b711e10f487b1763f0f88ab
   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 struct diff_options default_diff_options;
  35
  36static char diff_colors[][COLOR_MAXLEN] = {
  37        GIT_COLOR_RESET,
  38        GIT_COLOR_NORMAL,       /* PLAIN */
  39        GIT_COLOR_BOLD,         /* METAINFO */
  40        GIT_COLOR_CYAN,         /* FRAGINFO */
  41        GIT_COLOR_RED,          /* OLD */
  42        GIT_COLOR_GREEN,        /* NEW */
  43        GIT_COLOR_YELLOW,       /* COMMIT */
  44        GIT_COLOR_BG_RED,       /* WHITESPACE */
  45        GIT_COLOR_NORMAL,       /* FUNCINFO */
  46};
  47
  48static int parse_diff_color_slot(const char *var, int ofs)
  49{
  50        if (!strcasecmp(var+ofs, "plain"))
  51                return DIFF_PLAIN;
  52        if (!strcasecmp(var+ofs, "meta"))
  53                return DIFF_METAINFO;
  54        if (!strcasecmp(var+ofs, "frag"))
  55                return DIFF_FRAGINFO;
  56        if (!strcasecmp(var+ofs, "old"))
  57                return DIFF_FILE_OLD;
  58        if (!strcasecmp(var+ofs, "new"))
  59                return DIFF_FILE_NEW;
  60        if (!strcasecmp(var+ofs, "commit"))
  61                return DIFF_COMMIT;
  62        if (!strcasecmp(var+ofs, "whitespace"))
  63                return DIFF_WHITESPACE;
  64        if (!strcasecmp(var+ofs, "func"))
  65                return DIFF_FUNCINFO;
  66        return -1;
  67}
  68
  69static int parse_dirstat_params(struct diff_options *options, const char *params)
  70{
  71        const char *p = params;
  72        while (*p) {
  73                if (!prefixcmp(p, "changes")) {
  74                        p += 7;
  75                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  76                } else if (!prefixcmp(p, "files")) {
  77                        p += 5;
  78                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  79                } else if (!prefixcmp(p, "noncumulative")) {
  80                        p += 13;
  81                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  82                } else if (!prefixcmp(p, "cumulative")) {
  83                        p += 10;
  84                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  85                } else if (isdigit(*p)) {
  86                        char *end;
  87                        options->dirstat_percent = strtoul(p, &end, 10);
  88                        p = end;
  89                } else
  90                        return error("Unknown --dirstat parameter '%s'", p);
  91
  92                if (*p) {
  93                        /* more parameters, swallow separator */
  94                        if (*p != ',')
  95                                return error("Missing comma separator at char "
  96                                        "%"PRIuMAX" of '%s'",
  97                                        (uintmax_t) (p - params), params);
  98                        p++;
  99                }
 100        }
 101        return 0;
 102}
 103
 104static int git_config_rename(const char *var, const char *value)
 105{
 106        if (!value)
 107                return DIFF_DETECT_RENAME;
 108        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 109                return  DIFF_DETECT_COPY;
 110        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 111}
 112
 113/*
 114 * These are to give UI layer defaults.
 115 * The core-level commands such as git-diff-files should
 116 * never be affected by the setting of diff.renames
 117 * the user happens to have in the configuration file.
 118 */
 119int git_diff_ui_config(const char *var, const char *value, void *cb)
 120{
 121        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 122                diff_use_color_default = git_config_colorbool(var, value, -1);
 123                return 0;
 124        }
 125        if (!strcmp(var, "diff.renames")) {
 126                diff_detect_rename_default = git_config_rename(var, value);
 127                return 0;
 128        }
 129        if (!strcmp(var, "diff.autorefreshindex")) {
 130                diff_auto_refresh_index = git_config_bool(var, value);
 131                return 0;
 132        }
 133        if (!strcmp(var, "diff.mnemonicprefix")) {
 134                diff_mnemonic_prefix = git_config_bool(var, value);
 135                return 0;
 136        }
 137        if (!strcmp(var, "diff.noprefix")) {
 138                diff_no_prefix = git_config_bool(var, value);
 139                return 0;
 140        }
 141        if (!strcmp(var, "diff.external"))
 142                return git_config_string(&external_diff_cmd_cfg, var, value);
 143        if (!strcmp(var, "diff.wordregex"))
 144                return git_config_string(&diff_word_regex_cfg, var, value);
 145
 146        if (!strcmp(var, "diff.ignoresubmodules"))
 147                handle_ignore_submodules_arg(&default_diff_options, value);
 148
 149        return git_diff_basic_config(var, value, cb);
 150}
 151
 152int git_diff_basic_config(const char *var, const char *value, void *cb)
 153{
 154        if (!strcmp(var, "diff.renamelimit")) {
 155                diff_rename_limit_default = git_config_int(var, value);
 156                return 0;
 157        }
 158
 159        switch (userdiff_config(var, value)) {
 160                case 0: break;
 161                case -1: return -1;
 162                default: return 0;
 163        }
 164
 165        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 166                int slot = parse_diff_color_slot(var, 11);
 167                if (slot < 0)
 168                        return 0;
 169                if (!value)
 170                        return config_error_nonbool(var);
 171                color_parse(value, var, diff_colors[slot]);
 172                return 0;
 173        }
 174
 175        /* like GNU diff's --suppress-blank-empty option  */
 176        if (!strcmp(var, "diff.suppressblankempty") ||
 177                        /* for backwards compatibility */
 178                        !strcmp(var, "diff.suppress-blank-empty")) {
 179                diff_suppress_blank_empty = git_config_bool(var, value);
 180                return 0;
 181        }
 182
 183        if (!prefixcmp(var, "submodule."))
 184                return parse_submodule_config_option(var, value);
 185
 186        return git_color_default_config(var, value, cb);
 187}
 188
 189static char *quote_two(const char *one, const char *two)
 190{
 191        int need_one = quote_c_style(one, NULL, NULL, 1);
 192        int need_two = quote_c_style(two, NULL, NULL, 1);
 193        struct strbuf res = STRBUF_INIT;
 194
 195        if (need_one + need_two) {
 196                strbuf_addch(&res, '"');
 197                quote_c_style(one, &res, NULL, 1);
 198                quote_c_style(two, &res, NULL, 1);
 199                strbuf_addch(&res, '"');
 200        } else {
 201                strbuf_addstr(&res, one);
 202                strbuf_addstr(&res, two);
 203        }
 204        return strbuf_detach(&res, NULL);
 205}
 206
 207static const char *external_diff(void)
 208{
 209        static const char *external_diff_cmd = NULL;
 210        static int done_preparing = 0;
 211
 212        if (done_preparing)
 213                return external_diff_cmd;
 214        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 215        if (!external_diff_cmd)
 216                external_diff_cmd = external_diff_cmd_cfg;
 217        done_preparing = 1;
 218        return external_diff_cmd;
 219}
 220
 221static struct diff_tempfile {
 222        const char *name; /* filename external diff should read from */
 223        char hex[41];
 224        char mode[10];
 225        char tmp_path[PATH_MAX];
 226} diff_temp[2];
 227
 228typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 229
 230struct emit_callback {
 231        int color_diff;
 232        unsigned ws_rule;
 233        int blank_at_eof_in_preimage;
 234        int blank_at_eof_in_postimage;
 235        int lno_in_preimage;
 236        int lno_in_postimage;
 237        sane_truncate_fn truncate;
 238        const char **label_path;
 239        struct diff_words_data *diff_words;
 240        struct diff_options *opt;
 241        int *found_changesp;
 242        struct strbuf *header;
 243};
 244
 245static int count_lines(const char *data, int size)
 246{
 247        int count, ch, completely_empty = 1, nl_just_seen = 0;
 248        count = 0;
 249        while (0 < size--) {
 250                ch = *data++;
 251                if (ch == '\n') {
 252                        count++;
 253                        nl_just_seen = 1;
 254                        completely_empty = 0;
 255                }
 256                else {
 257                        nl_just_seen = 0;
 258                        completely_empty = 0;
 259                }
 260        }
 261        if (completely_empty)
 262                return 0;
 263        if (!nl_just_seen)
 264                count++; /* no trailing newline */
 265        return count;
 266}
 267
 268static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 269{
 270        if (!DIFF_FILE_VALID(one)) {
 271                mf->ptr = (char *)""; /* does not matter */
 272                mf->size = 0;
 273                return 0;
 274        }
 275        else if (diff_populate_filespec(one, 0))
 276                return -1;
 277
 278        mf->ptr = one->data;
 279        mf->size = one->size;
 280        return 0;
 281}
 282
 283/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 284static unsigned long diff_filespec_size(struct diff_filespec *one)
 285{
 286        if (!DIFF_FILE_VALID(one))
 287                return 0;
 288        diff_populate_filespec(one, 1);
 289        return one->size;
 290}
 291
 292static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 293{
 294        char *ptr = mf->ptr;
 295        long size = mf->size;
 296        int cnt = 0;
 297
 298        if (!size)
 299                return cnt;
 300        ptr += size - 1; /* pointing at the very end */
 301        if (*ptr != '\n')
 302                ; /* incomplete line */
 303        else
 304                ptr--; /* skip the last LF */
 305        while (mf->ptr < ptr) {
 306                char *prev_eol;
 307                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 308                        if (*prev_eol == '\n')
 309                                break;
 310                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 311                        break;
 312                cnt++;
 313                ptr = prev_eol - 1;
 314        }
 315        return cnt;
 316}
 317
 318static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 319                               struct emit_callback *ecbdata)
 320{
 321        int l1, l2, at;
 322        unsigned ws_rule = ecbdata->ws_rule;
 323        l1 = count_trailing_blank(mf1, ws_rule);
 324        l2 = count_trailing_blank(mf2, ws_rule);
 325        if (l2 <= l1) {
 326                ecbdata->blank_at_eof_in_preimage = 0;
 327                ecbdata->blank_at_eof_in_postimage = 0;
 328                return;
 329        }
 330        at = count_lines(mf1->ptr, mf1->size);
 331        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 332
 333        at = count_lines(mf2->ptr, mf2->size);
 334        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 335}
 336
 337static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 338                        int first, const char *line, int len)
 339{
 340        int has_trailing_newline, has_trailing_carriage_return;
 341        int nofirst;
 342        FILE *file = o->file;
 343
 344        if (o->output_prefix) {
 345                struct strbuf *msg = NULL;
 346                msg = o->output_prefix(o, o->output_prefix_data);
 347                assert(msg);
 348                fwrite(msg->buf, msg->len, 1, file);
 349        }
 350
 351        if (len == 0) {
 352                has_trailing_newline = (first == '\n');
 353                has_trailing_carriage_return = (!has_trailing_newline &&
 354                                                (first == '\r'));
 355                nofirst = has_trailing_newline || has_trailing_carriage_return;
 356        } else {
 357                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 358                if (has_trailing_newline)
 359                        len--;
 360                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 361                if (has_trailing_carriage_return)
 362                        len--;
 363                nofirst = 0;
 364        }
 365
 366        if (len || !nofirst) {
 367                fputs(set, file);
 368                if (!nofirst)
 369                        fputc(first, file);
 370                fwrite(line, len, 1, file);
 371                fputs(reset, file);
 372        }
 373        if (has_trailing_carriage_return)
 374                fputc('\r', file);
 375        if (has_trailing_newline)
 376                fputc('\n', file);
 377}
 378
 379static void emit_line(struct diff_options *o, const char *set, const char *reset,
 380                      const char *line, int len)
 381{
 382        emit_line_0(o, set, reset, line[0], line+1, len-1);
 383}
 384
 385static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 386{
 387        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 388              ecbdata->blank_at_eof_in_preimage &&
 389              ecbdata->blank_at_eof_in_postimage &&
 390              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 391              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 392                return 0;
 393        return ws_blank_line(line, len, ecbdata->ws_rule);
 394}
 395
 396static void emit_add_line(const char *reset,
 397                          struct emit_callback *ecbdata,
 398                          const char *line, int len)
 399{
 400        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 401        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 402
 403        if (!*ws)
 404                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 405        else if (new_blank_line_at_eof(ecbdata, line, len))
 406                /* Blank line at EOF - paint '+' as well */
 407                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 408        else {
 409                /* Emit just the prefix, then the rest. */
 410                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 411                ws_check_emit(line, len, ecbdata->ws_rule,
 412                              ecbdata->opt->file, set, reset, ws);
 413        }
 414}
 415
 416static void emit_hunk_header(struct emit_callback *ecbdata,
 417                             const char *line, int len)
 418{
 419        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 420        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 421        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 422        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 423        static const char atat[2] = { '@', '@' };
 424        const char *cp, *ep;
 425        struct strbuf msgbuf = STRBUF_INIT;
 426        int org_len = len;
 427        int i = 1;
 428
 429        /*
 430         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 431         * it always is at least 10 bytes long.
 432         */
 433        if (len < 10 ||
 434            memcmp(line, atat, 2) ||
 435            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 436                emit_line(ecbdata->opt, plain, reset, line, len);
 437                return;
 438        }
 439        ep += 2; /* skip over @@ */
 440
 441        /* The hunk header in fraginfo color */
 442        strbuf_add(&msgbuf, frag, strlen(frag));
 443        strbuf_add(&msgbuf, line, ep - line);
 444        strbuf_add(&msgbuf, reset, strlen(reset));
 445
 446        /*
 447         * trailing "\r\n"
 448         */
 449        for ( ; i < 3; i++)
 450                if (line[len - i] == '\r' || line[len - i] == '\n')
 451                        len--;
 452
 453        /* blank before the func header */
 454        for (cp = ep; ep - line < len; ep++)
 455                if (*ep != ' ' && *ep != '\t')
 456                        break;
 457        if (ep != cp) {
 458                strbuf_add(&msgbuf, plain, strlen(plain));
 459                strbuf_add(&msgbuf, cp, ep - cp);
 460                strbuf_add(&msgbuf, reset, strlen(reset));
 461        }
 462
 463        if (ep < line + len) {
 464                strbuf_add(&msgbuf, func, strlen(func));
 465                strbuf_add(&msgbuf, ep, line + len - ep);
 466                strbuf_add(&msgbuf, reset, strlen(reset));
 467        }
 468
 469        strbuf_add(&msgbuf, line + len, org_len - len);
 470        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 471        strbuf_release(&msgbuf);
 472}
 473
 474static struct diff_tempfile *claim_diff_tempfile(void) {
 475        int i;
 476        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 477                if (!diff_temp[i].name)
 478                        return diff_temp + i;
 479        die("BUG: diff is failing to clean up its tempfiles");
 480}
 481
 482static int remove_tempfile_installed;
 483
 484static void remove_tempfile(void)
 485{
 486        int i;
 487        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 488                if (diff_temp[i].name == diff_temp[i].tmp_path)
 489                        unlink_or_warn(diff_temp[i].name);
 490                diff_temp[i].name = NULL;
 491        }
 492}
 493
 494static void remove_tempfile_on_signal(int signo)
 495{
 496        remove_tempfile();
 497        sigchain_pop(signo);
 498        raise(signo);
 499}
 500
 501static void print_line_count(FILE *file, int count)
 502{
 503        switch (count) {
 504        case 0:
 505                fprintf(file, "0,0");
 506                break;
 507        case 1:
 508                fprintf(file, "1");
 509                break;
 510        default:
 511                fprintf(file, "1,%d", count);
 512                break;
 513        }
 514}
 515
 516static void emit_rewrite_lines(struct emit_callback *ecb,
 517                               int prefix, const char *data, int size)
 518{
 519        const char *endp = NULL;
 520        static const char *nneof = " No newline at end of file\n";
 521        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 522        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 523
 524        while (0 < size) {
 525                int len;
 526
 527                endp = memchr(data, '\n', size);
 528                len = endp ? (endp - data + 1) : size;
 529                if (prefix != '+') {
 530                        ecb->lno_in_preimage++;
 531                        emit_line_0(ecb->opt, old, reset, '-',
 532                                    data, len);
 533                } else {
 534                        ecb->lno_in_postimage++;
 535                        emit_add_line(reset, ecb, data, len);
 536                }
 537                size -= len;
 538                data += len;
 539        }
 540        if (!endp) {
 541                const char *plain = diff_get_color(ecb->color_diff,
 542                                                   DIFF_PLAIN);
 543                emit_line_0(ecb->opt, plain, reset, '\\',
 544                            nneof, strlen(nneof));
 545        }
 546}
 547
 548static void emit_rewrite_diff(const char *name_a,
 549                              const char *name_b,
 550                              struct diff_filespec *one,
 551                              struct diff_filespec *two,
 552                              struct userdiff_driver *textconv_one,
 553                              struct userdiff_driver *textconv_two,
 554                              struct diff_options *o)
 555{
 556        int lc_a, lc_b;
 557        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 558        const char *name_a_tab, *name_b_tab;
 559        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 560        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 561        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 562        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 563        const char *a_prefix, *b_prefix;
 564        char *data_one, *data_two;
 565        size_t size_one, size_two;
 566        struct emit_callback ecbdata;
 567        char *line_prefix = "";
 568        struct strbuf *msgbuf;
 569
 570        if (o && o->output_prefix) {
 571                msgbuf = o->output_prefix(o, o->output_prefix_data);
 572                line_prefix = msgbuf->buf;
 573        }
 574
 575        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 576                a_prefix = o->b_prefix;
 577                b_prefix = o->a_prefix;
 578        } else {
 579                a_prefix = o->a_prefix;
 580                b_prefix = o->b_prefix;
 581        }
 582
 583        name_a += (*name_a == '/');
 584        name_b += (*name_b == '/');
 585        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 586        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 587
 588        strbuf_reset(&a_name);
 589        strbuf_reset(&b_name);
 590        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 591        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 592
 593        size_one = fill_textconv(textconv_one, one, &data_one);
 594        size_two = fill_textconv(textconv_two, two, &data_two);
 595
 596        memset(&ecbdata, 0, sizeof(ecbdata));
 597        ecbdata.color_diff = color_diff;
 598        ecbdata.found_changesp = &o->found_changes;
 599        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 600        ecbdata.opt = o;
 601        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 602                mmfile_t mf1, mf2;
 603                mf1.ptr = (char *)data_one;
 604                mf2.ptr = (char *)data_two;
 605                mf1.size = size_one;
 606                mf2.size = size_two;
 607                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 608        }
 609        ecbdata.lno_in_preimage = 1;
 610        ecbdata.lno_in_postimage = 1;
 611
 612        lc_a = count_lines(data_one, size_one);
 613        lc_b = count_lines(data_two, size_two);
 614        fprintf(o->file,
 615                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 616                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 617                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 618                line_prefix, fraginfo);
 619        if (!o->irreversible_delete)
 620                print_line_count(o->file, lc_a);
 621        else
 622                fprintf(o->file, "?,?");
 623        fprintf(o->file, " +");
 624        print_line_count(o->file, lc_b);
 625        fprintf(o->file, " @@%s\n", reset);
 626        if (lc_a && !o->irreversible_delete)
 627                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 628        if (lc_b)
 629                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 630        if (textconv_one)
 631                free((char *)data_one);
 632        if (textconv_two)
 633                free((char *)data_two);
 634}
 635
 636struct diff_words_buffer {
 637        mmfile_t text;
 638        long alloc;
 639        struct diff_words_orig {
 640                const char *begin, *end;
 641        } *orig;
 642        int orig_nr, orig_alloc;
 643};
 644
 645static void diff_words_append(char *line, unsigned long len,
 646                struct diff_words_buffer *buffer)
 647{
 648        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 649        line++;
 650        len--;
 651        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 652        buffer->text.size += len;
 653        buffer->text.ptr[buffer->text.size] = '\0';
 654}
 655
 656struct diff_words_style_elem {
 657        const char *prefix;
 658        const char *suffix;
 659        const char *color; /* NULL; filled in by the setup code if
 660                            * color is enabled */
 661};
 662
 663struct diff_words_style {
 664        enum diff_words_type type;
 665        struct diff_words_style_elem new, old, ctx;
 666        const char *newline;
 667};
 668
 669static struct diff_words_style diff_words_styles[] = {
 670        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 671        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 672        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 673};
 674
 675struct diff_words_data {
 676        struct diff_words_buffer minus, plus;
 677        const char *current_plus;
 678        int last_minus;
 679        struct diff_options *opt;
 680        regex_t *word_regex;
 681        enum diff_words_type type;
 682        struct diff_words_style *style;
 683};
 684
 685static int fn_out_diff_words_write_helper(FILE *fp,
 686                                          struct diff_words_style_elem *st_el,
 687                                          const char *newline,
 688                                          size_t count, const char *buf,
 689                                          const char *line_prefix)
 690{
 691        int print = 0;
 692
 693        while (count) {
 694                char *p = memchr(buf, '\n', count);
 695                if (print)
 696                        fputs(line_prefix, fp);
 697                if (p != buf) {
 698                        if (st_el->color && fputs(st_el->color, fp) < 0)
 699                                return -1;
 700                        if (fputs(st_el->prefix, fp) < 0 ||
 701                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 702                            fputs(st_el->suffix, fp) < 0)
 703                                return -1;
 704                        if (st_el->color && *st_el->color
 705                            && fputs(GIT_COLOR_RESET, fp) < 0)
 706                                return -1;
 707                }
 708                if (!p)
 709                        return 0;
 710                if (fputs(newline, fp) < 0)
 711                        return -1;
 712                count -= p + 1 - buf;
 713                buf = p + 1;
 714                print = 1;
 715        }
 716        return 0;
 717}
 718
 719/*
 720 * '--color-words' algorithm can be described as:
 721 *
 722 *   1. collect a the minus/plus lines of a diff hunk, divided into
 723 *      minus-lines and plus-lines;
 724 *
 725 *   2. break both minus-lines and plus-lines into words and
 726 *      place them into two mmfile_t with one word for each line;
 727 *
 728 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 729 *
 730 * And for the common parts of the both file, we output the plus side text.
 731 * diff_words->current_plus is used to trace the current position of the plus file
 732 * which printed. diff_words->last_minus is used to trace the last minus word
 733 * printed.
 734 *
 735 * For '--graph' to work with '--color-words', we need to output the graph prefix
 736 * on each line of color words output. Generally, there are two conditions on
 737 * which we should output the prefix.
 738 *
 739 *   1. diff_words->last_minus == 0 &&
 740 *      diff_words->current_plus == diff_words->plus.text.ptr
 741 *
 742 *      that is: the plus text must start as a new line, and if there is no minus
 743 *      word printed, a graph prefix must be printed.
 744 *
 745 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 746 *      *(diff_words->current_plus - 1) == '\n'
 747 *
 748 *      that is: a graph prefix must be printed following a '\n'
 749 */
 750static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 751{
 752        if ((diff_words->last_minus == 0 &&
 753                diff_words->current_plus == diff_words->plus.text.ptr) ||
 754                (diff_words->current_plus > diff_words->plus.text.ptr &&
 755                *(diff_words->current_plus - 1) == '\n')) {
 756                return 1;
 757        } else {
 758                return 0;
 759        }
 760}
 761
 762static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 763{
 764        struct diff_words_data *diff_words = priv;
 765        struct diff_words_style *style = diff_words->style;
 766        int minus_first, minus_len, plus_first, plus_len;
 767        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 768        struct diff_options *opt = diff_words->opt;
 769        struct strbuf *msgbuf;
 770        char *line_prefix = "";
 771
 772        if (line[0] != '@' || parse_hunk_header(line, len,
 773                        &minus_first, &minus_len, &plus_first, &plus_len))
 774                return;
 775
 776        assert(opt);
 777        if (opt->output_prefix) {
 778                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 779                line_prefix = msgbuf->buf;
 780        }
 781
 782        /* POSIX requires that first be decremented by one if len == 0... */
 783        if (minus_len) {
 784                minus_begin = diff_words->minus.orig[minus_first].begin;
 785                minus_end =
 786                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 787        } else
 788                minus_begin = minus_end =
 789                        diff_words->minus.orig[minus_first].end;
 790
 791        if (plus_len) {
 792                plus_begin = diff_words->plus.orig[plus_first].begin;
 793                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 794        } else
 795                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 796
 797        if (color_words_output_graph_prefix(diff_words)) {
 798                fputs(line_prefix, diff_words->opt->file);
 799        }
 800        if (diff_words->current_plus != plus_begin) {
 801                fn_out_diff_words_write_helper(diff_words->opt->file,
 802                                &style->ctx, style->newline,
 803                                plus_begin - diff_words->current_plus,
 804                                diff_words->current_plus, line_prefix);
 805                if (*(plus_begin - 1) == '\n')
 806                        fputs(line_prefix, diff_words->opt->file);
 807        }
 808        if (minus_begin != minus_end) {
 809                fn_out_diff_words_write_helper(diff_words->opt->file,
 810                                &style->old, style->newline,
 811                                minus_end - minus_begin, minus_begin,
 812                                line_prefix);
 813        }
 814        if (plus_begin != plus_end) {
 815                fn_out_diff_words_write_helper(diff_words->opt->file,
 816                                &style->new, style->newline,
 817                                plus_end - plus_begin, plus_begin,
 818                                line_prefix);
 819        }
 820
 821        diff_words->current_plus = plus_end;
 822        diff_words->last_minus = minus_first;
 823}
 824
 825/* This function starts looking at *begin, and returns 0 iff a word was found. */
 826static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 827                int *begin, int *end)
 828{
 829        if (word_regex && *begin < buffer->size) {
 830                regmatch_t match[1];
 831                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 832                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 833                                        '\n', match[0].rm_eo - match[0].rm_so);
 834                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 835                        *begin += match[0].rm_so;
 836                        return *begin >= *end;
 837                }
 838                return -1;
 839        }
 840
 841        /* find the next word */
 842        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 843                (*begin)++;
 844        if (*begin >= buffer->size)
 845                return -1;
 846
 847        /* find the end of the word */
 848        *end = *begin + 1;
 849        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 850                (*end)++;
 851
 852        return 0;
 853}
 854
 855/*
 856 * This function splits the words in buffer->text, stores the list with
 857 * newline separator into out, and saves the offsets of the original words
 858 * in buffer->orig.
 859 */
 860static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 861                regex_t *word_regex)
 862{
 863        int i, j;
 864        long alloc = 0;
 865
 866        out->size = 0;
 867        out->ptr = NULL;
 868
 869        /* fake an empty "0th" word */
 870        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 871        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 872        buffer->orig_nr = 1;
 873
 874        for (i = 0; i < buffer->text.size; i++) {
 875                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 876                        return;
 877
 878                /* store original boundaries */
 879                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 880                                buffer->orig_alloc);
 881                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 882                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 883                buffer->orig_nr++;
 884
 885                /* store one word */
 886                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 887                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 888                out->ptr[out->size + j - i] = '\n';
 889                out->size += j - i + 1;
 890
 891                i = j - 1;
 892        }
 893}
 894
 895/* this executes the word diff on the accumulated buffers */
 896static void diff_words_show(struct diff_words_data *diff_words)
 897{
 898        xpparam_t xpp;
 899        xdemitconf_t xecfg;
 900        mmfile_t minus, plus;
 901        struct diff_words_style *style = diff_words->style;
 902
 903        struct diff_options *opt = diff_words->opt;
 904        struct strbuf *msgbuf;
 905        char *line_prefix = "";
 906
 907        assert(opt);
 908        if (opt->output_prefix) {
 909                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 910                line_prefix = msgbuf->buf;
 911        }
 912
 913        /* special case: only removal */
 914        if (!diff_words->plus.text.size) {
 915                fputs(line_prefix, diff_words->opt->file);
 916                fn_out_diff_words_write_helper(diff_words->opt->file,
 917                        &style->old, style->newline,
 918                        diff_words->minus.text.size,
 919                        diff_words->minus.text.ptr, line_prefix);
 920                diff_words->minus.text.size = 0;
 921                return;
 922        }
 923
 924        diff_words->current_plus = diff_words->plus.text.ptr;
 925        diff_words->last_minus = 0;
 926
 927        memset(&xpp, 0, sizeof(xpp));
 928        memset(&xecfg, 0, sizeof(xecfg));
 929        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 930        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 931        xpp.flags = 0;
 932        /* as only the hunk header will be parsed, we need a 0-context */
 933        xecfg.ctxlen = 0;
 934        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 935                      &xpp, &xecfg);
 936        free(minus.ptr);
 937        free(plus.ptr);
 938        if (diff_words->current_plus != diff_words->plus.text.ptr +
 939                        diff_words->plus.text.size) {
 940                if (color_words_output_graph_prefix(diff_words))
 941                        fputs(line_prefix, diff_words->opt->file);
 942                fn_out_diff_words_write_helper(diff_words->opt->file,
 943                        &style->ctx, style->newline,
 944                        diff_words->plus.text.ptr + diff_words->plus.text.size
 945                        - diff_words->current_plus, diff_words->current_plus,
 946                        line_prefix);
 947        }
 948        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 949}
 950
 951/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 952static void diff_words_flush(struct emit_callback *ecbdata)
 953{
 954        if (ecbdata->diff_words->minus.text.size ||
 955            ecbdata->diff_words->plus.text.size)
 956                diff_words_show(ecbdata->diff_words);
 957}
 958
 959static void free_diff_words_data(struct emit_callback *ecbdata)
 960{
 961        if (ecbdata->diff_words) {
 962                diff_words_flush(ecbdata);
 963                free (ecbdata->diff_words->minus.text.ptr);
 964                free (ecbdata->diff_words->minus.orig);
 965                free (ecbdata->diff_words->plus.text.ptr);
 966                free (ecbdata->diff_words->plus.orig);
 967                if (ecbdata->diff_words->word_regex) {
 968                        regfree(ecbdata->diff_words->word_regex);
 969                        free(ecbdata->diff_words->word_regex);
 970                }
 971                free(ecbdata->diff_words);
 972                ecbdata->diff_words = NULL;
 973        }
 974}
 975
 976const char *diff_get_color(int diff_use_color, enum color_diff ix)
 977{
 978        if (diff_use_color)
 979                return diff_colors[ix];
 980        return "";
 981}
 982
 983static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 984{
 985        const char *cp;
 986        unsigned long allot;
 987        size_t l = len;
 988
 989        if (ecb->truncate)
 990                return ecb->truncate(line, len);
 991        cp = line;
 992        allot = l;
 993        while (0 < l) {
 994                (void) utf8_width(&cp, &l);
 995                if (!cp)
 996                        break; /* truncated in the middle? */
 997        }
 998        return allot - l;
 999}
1000
1001static void find_lno(const char *line, struct emit_callback *ecbdata)
1002{
1003        const char *p;
1004        ecbdata->lno_in_preimage = 0;
1005        ecbdata->lno_in_postimage = 0;
1006        p = strchr(line, '-');
1007        if (!p)
1008                return; /* cannot happen */
1009        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1010        p = strchr(p, '+');
1011        if (!p)
1012                return; /* cannot happen */
1013        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1014}
1015
1016static void fn_out_consume(void *priv, char *line, unsigned long len)
1017{
1018        struct emit_callback *ecbdata = priv;
1019        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1020        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1021        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1022        struct diff_options *o = ecbdata->opt;
1023        char *line_prefix = "";
1024        struct strbuf *msgbuf;
1025
1026        if (o && o->output_prefix) {
1027                msgbuf = o->output_prefix(o, o->output_prefix_data);
1028                line_prefix = msgbuf->buf;
1029        }
1030
1031        if (ecbdata->header) {
1032                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1033                strbuf_reset(ecbdata->header);
1034                ecbdata->header = NULL;
1035        }
1036        *(ecbdata->found_changesp) = 1;
1037
1038        if (ecbdata->label_path[0]) {
1039                const char *name_a_tab, *name_b_tab;
1040
1041                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1042                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1043
1044                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1045                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1046                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1047                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1048                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1049        }
1050
1051        if (diff_suppress_blank_empty
1052            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1053                line[0] = '\n';
1054                len = 1;
1055        }
1056
1057        if (line[0] == '@') {
1058                if (ecbdata->diff_words)
1059                        diff_words_flush(ecbdata);
1060                len = sane_truncate_line(ecbdata, line, len);
1061                find_lno(line, ecbdata);
1062                emit_hunk_header(ecbdata, line, len);
1063                if (line[len-1] != '\n')
1064                        putc('\n', ecbdata->opt->file);
1065                return;
1066        }
1067
1068        if (len < 1) {
1069                emit_line(ecbdata->opt, reset, reset, line, len);
1070                if (ecbdata->diff_words
1071                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1072                        fputs("~\n", ecbdata->opt->file);
1073                return;
1074        }
1075
1076        if (ecbdata->diff_words) {
1077                if (line[0] == '-') {
1078                        diff_words_append(line, len,
1079                                          &ecbdata->diff_words->minus);
1080                        return;
1081                } else if (line[0] == '+') {
1082                        diff_words_append(line, len,
1083                                          &ecbdata->diff_words->plus);
1084                        return;
1085                }
1086                diff_words_flush(ecbdata);
1087                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1088                        emit_line(ecbdata->opt, plain, reset, line, len);
1089                        fputs("~\n", ecbdata->opt->file);
1090                } else {
1091                        /* don't print the prefix character */
1092                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1093                }
1094                return;
1095        }
1096
1097        if (line[0] != '+') {
1098                const char *color =
1099                        diff_get_color(ecbdata->color_diff,
1100                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1101                ecbdata->lno_in_preimage++;
1102                if (line[0] == ' ')
1103                        ecbdata->lno_in_postimage++;
1104                emit_line(ecbdata->opt, color, reset, line, len);
1105        } else {
1106                ecbdata->lno_in_postimage++;
1107                emit_add_line(reset, ecbdata, line + 1, len - 1);
1108        }
1109}
1110
1111static char *pprint_rename(const char *a, const char *b)
1112{
1113        const char *old = a;
1114        const char *new = b;
1115        struct strbuf name = STRBUF_INIT;
1116        int pfx_length, sfx_length;
1117        int len_a = strlen(a);
1118        int len_b = strlen(b);
1119        int a_midlen, b_midlen;
1120        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1121        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1122
1123        if (qlen_a || qlen_b) {
1124                quote_c_style(a, &name, NULL, 0);
1125                strbuf_addstr(&name, " => ");
1126                quote_c_style(b, &name, NULL, 0);
1127                return strbuf_detach(&name, NULL);
1128        }
1129
1130        /* Find common prefix */
1131        pfx_length = 0;
1132        while (*old && *new && *old == *new) {
1133                if (*old == '/')
1134                        pfx_length = old - a + 1;
1135                old++;
1136                new++;
1137        }
1138
1139        /* Find common suffix */
1140        old = a + len_a;
1141        new = b + len_b;
1142        sfx_length = 0;
1143        while (a <= old && b <= new && *old == *new) {
1144                if (*old == '/')
1145                        sfx_length = len_a - (old - a);
1146                old--;
1147                new--;
1148        }
1149
1150        /*
1151         * pfx{mid-a => mid-b}sfx
1152         * {pfx-a => pfx-b}sfx
1153         * pfx{sfx-a => sfx-b}
1154         * name-a => name-b
1155         */
1156        a_midlen = len_a - pfx_length - sfx_length;
1157        b_midlen = len_b - pfx_length - sfx_length;
1158        if (a_midlen < 0)
1159                a_midlen = 0;
1160        if (b_midlen < 0)
1161                b_midlen = 0;
1162
1163        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1164        if (pfx_length + sfx_length) {
1165                strbuf_add(&name, a, pfx_length);
1166                strbuf_addch(&name, '{');
1167        }
1168        strbuf_add(&name, a + pfx_length, a_midlen);
1169        strbuf_addstr(&name, " => ");
1170        strbuf_add(&name, b + pfx_length, b_midlen);
1171        if (pfx_length + sfx_length) {
1172                strbuf_addch(&name, '}');
1173                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1174        }
1175        return strbuf_detach(&name, NULL);
1176}
1177
1178struct diffstat_t {
1179        int nr;
1180        int alloc;
1181        struct diffstat_file {
1182                char *from_name;
1183                char *name;
1184                char *print_name;
1185                unsigned is_unmerged:1;
1186                unsigned is_binary:1;
1187                unsigned is_renamed:1;
1188                uintmax_t added, deleted;
1189        } **files;
1190};
1191
1192static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1193                                          const char *name_a,
1194                                          const char *name_b)
1195{
1196        struct diffstat_file *x;
1197        x = xcalloc(sizeof (*x), 1);
1198        if (diffstat->nr == diffstat->alloc) {
1199                diffstat->alloc = alloc_nr(diffstat->alloc);
1200                diffstat->files = xrealloc(diffstat->files,
1201                                diffstat->alloc * sizeof(x));
1202        }
1203        diffstat->files[diffstat->nr++] = x;
1204        if (name_b) {
1205                x->from_name = xstrdup(name_a);
1206                x->name = xstrdup(name_b);
1207                x->is_renamed = 1;
1208        }
1209        else {
1210                x->from_name = NULL;
1211                x->name = xstrdup(name_a);
1212        }
1213        return x;
1214}
1215
1216static void diffstat_consume(void *priv, char *line, unsigned long len)
1217{
1218        struct diffstat_t *diffstat = priv;
1219        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1220
1221        if (line[0] == '+')
1222                x->added++;
1223        else if (line[0] == '-')
1224                x->deleted++;
1225}
1226
1227const char mime_boundary_leader[] = "------------";
1228
1229static int scale_linear(int it, int width, int max_change)
1230{
1231        /*
1232         * make sure that at least one '-' is printed if there were deletions,
1233         * and likewise for '+'.
1234         */
1235        if (max_change < 2)
1236                return it;
1237        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1238}
1239
1240static void show_name(FILE *file,
1241                      const char *prefix, const char *name, int len)
1242{
1243        fprintf(file, " %s%-*s |", prefix, len, name);
1244}
1245
1246static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1247{
1248        if (cnt <= 0)
1249                return;
1250        fprintf(file, "%s", set);
1251        while (cnt--)
1252                putc(ch, file);
1253        fprintf(file, "%s", reset);
1254}
1255
1256static void fill_print_name(struct diffstat_file *file)
1257{
1258        char *pname;
1259
1260        if (file->print_name)
1261                return;
1262
1263        if (!file->is_renamed) {
1264                struct strbuf buf = STRBUF_INIT;
1265                if (quote_c_style(file->name, &buf, NULL, 0)) {
1266                        pname = strbuf_detach(&buf, NULL);
1267                } else {
1268                        pname = file->name;
1269                        strbuf_release(&buf);
1270                }
1271        } else {
1272                pname = pprint_rename(file->from_name, file->name);
1273        }
1274        file->print_name = pname;
1275}
1276
1277static void show_stats(struct diffstat_t *data, struct diff_options *options)
1278{
1279        int i, len, add, del, adds = 0, dels = 0;
1280        uintmax_t max_change = 0, max_len = 0;
1281        int total_files = data->nr;
1282        int width, name_width;
1283        const char *reset, *add_c, *del_c;
1284        const char *line_prefix = "";
1285        struct strbuf *msg = NULL;
1286
1287        if (data->nr == 0)
1288                return;
1289
1290        if (options->output_prefix) {
1291                msg = options->output_prefix(options, options->output_prefix_data);
1292                line_prefix = msg->buf;
1293        }
1294
1295        width = options->stat_width ? options->stat_width : 80;
1296        name_width = options->stat_name_width ? options->stat_name_width : 50;
1297
1298        /* Sanity: give at least 5 columns to the graph,
1299         * but leave at least 10 columns for the name.
1300         */
1301        if (width < 25)
1302                width = 25;
1303        if (name_width < 10)
1304                name_width = 10;
1305        else if (width < name_width + 15)
1306                name_width = width - 15;
1307
1308        /* Find the longest filename and max number of changes */
1309        reset = diff_get_color_opt(options, DIFF_RESET);
1310        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1311        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1312
1313        for (i = 0; i < data->nr; i++) {
1314                struct diffstat_file *file = data->files[i];
1315                uintmax_t change = file->added + file->deleted;
1316                fill_print_name(file);
1317                len = strlen(file->print_name);
1318                if (max_len < len)
1319                        max_len = len;
1320
1321                if (file->is_binary || file->is_unmerged)
1322                        continue;
1323                if (max_change < change)
1324                        max_change = change;
1325        }
1326
1327        /* Compute the width of the graph part;
1328         * 10 is for one blank at the beginning of the line plus
1329         * " | count " between the name and the graph.
1330         *
1331         * From here on, name_width is the width of the name area,
1332         * and width is the width of the graph area.
1333         */
1334        name_width = (name_width < max_len) ? name_width : max_len;
1335        if (width < (name_width + 10) + max_change)
1336                width = width - (name_width + 10);
1337        else
1338                width = max_change;
1339
1340        for (i = 0; i < data->nr; i++) {
1341                const char *prefix = "";
1342                char *name = data->files[i]->print_name;
1343                uintmax_t added = data->files[i]->added;
1344                uintmax_t deleted = data->files[i]->deleted;
1345                int name_len;
1346
1347                /*
1348                 * "scale" the filename
1349                 */
1350                len = name_width;
1351                name_len = strlen(name);
1352                if (name_width < name_len) {
1353                        char *slash;
1354                        prefix = "...";
1355                        len -= 3;
1356                        name += name_len - len;
1357                        slash = strchr(name, '/');
1358                        if (slash)
1359                                name = slash;
1360                }
1361
1362                if (data->files[i]->is_binary) {
1363                        fprintf(options->file, "%s", line_prefix);
1364                        show_name(options->file, prefix, name, len);
1365                        fprintf(options->file, "  Bin ");
1366                        fprintf(options->file, "%s%"PRIuMAX"%s",
1367                                del_c, deleted, reset);
1368                        fprintf(options->file, " -> ");
1369                        fprintf(options->file, "%s%"PRIuMAX"%s",
1370                                add_c, added, reset);
1371                        fprintf(options->file, " bytes");
1372                        fprintf(options->file, "\n");
1373                        continue;
1374                }
1375                else if (data->files[i]->is_unmerged) {
1376                        fprintf(options->file, "%s", line_prefix);
1377                        show_name(options->file, prefix, name, len);
1378                        fprintf(options->file, "  Unmerged\n");
1379                        continue;
1380                }
1381                else if (!data->files[i]->is_renamed &&
1382                         (added + deleted == 0)) {
1383                        total_files--;
1384                        continue;
1385                }
1386
1387                /*
1388                 * scale the add/delete
1389                 */
1390                add = added;
1391                del = deleted;
1392                adds += add;
1393                dels += del;
1394
1395                if (width <= max_change) {
1396                        add = scale_linear(add, width, max_change);
1397                        del = scale_linear(del, width, max_change);
1398                }
1399                fprintf(options->file, "%s", line_prefix);
1400                show_name(options->file, prefix, name, len);
1401                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1402                                added + deleted ? " " : "");
1403                show_graph(options->file, '+', add, add_c, reset);
1404                show_graph(options->file, '-', del, del_c, reset);
1405                fprintf(options->file, "\n");
1406        }
1407        fprintf(options->file, "%s", line_prefix);
1408        fprintf(options->file,
1409               " %d files changed, %d insertions(+), %d deletions(-)\n",
1410               total_files, adds, dels);
1411}
1412
1413static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1414{
1415        int i, adds = 0, dels = 0, total_files = data->nr;
1416
1417        if (data->nr == 0)
1418                return;
1419
1420        for (i = 0; i < data->nr; i++) {
1421                if (!data->files[i]->is_binary &&
1422                    !data->files[i]->is_unmerged) {
1423                        int added = data->files[i]->added;
1424                        int deleted= data->files[i]->deleted;
1425                        if (!data->files[i]->is_renamed &&
1426                            (added + deleted == 0)) {
1427                                total_files--;
1428                        } else {
1429                                adds += added;
1430                                dels += deleted;
1431                        }
1432                }
1433        }
1434        if (options->output_prefix) {
1435                struct strbuf *msg = NULL;
1436                msg = options->output_prefix(options,
1437                                options->output_prefix_data);
1438                fprintf(options->file, "%s", msg->buf);
1439        }
1440        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1441               total_files, adds, dels);
1442}
1443
1444static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1445{
1446        int i;
1447
1448        if (data->nr == 0)
1449                return;
1450
1451        for (i = 0; i < data->nr; i++) {
1452                struct diffstat_file *file = data->files[i];
1453
1454                if (options->output_prefix) {
1455                        struct strbuf *msg = NULL;
1456                        msg = options->output_prefix(options,
1457                                        options->output_prefix_data);
1458                        fprintf(options->file, "%s", msg->buf);
1459                }
1460
1461                if (file->is_binary)
1462                        fprintf(options->file, "-\t-\t");
1463                else
1464                        fprintf(options->file,
1465                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1466                                file->added, file->deleted);
1467                if (options->line_termination) {
1468                        fill_print_name(file);
1469                        if (!file->is_renamed)
1470                                write_name_quoted(file->name, options->file,
1471                                                  options->line_termination);
1472                        else {
1473                                fputs(file->print_name, options->file);
1474                                putc(options->line_termination, options->file);
1475                        }
1476                } else {
1477                        if (file->is_renamed) {
1478                                putc('\0', options->file);
1479                                write_name_quoted(file->from_name, options->file, '\0');
1480                        }
1481                        write_name_quoted(file->name, options->file, '\0');
1482                }
1483        }
1484}
1485
1486struct dirstat_file {
1487        const char *name;
1488        unsigned long changed;
1489};
1490
1491struct dirstat_dir {
1492        struct dirstat_file *files;
1493        int alloc, nr, percent, cumulative;
1494};
1495
1496static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1497                unsigned long changed, const char *base, int baselen)
1498{
1499        unsigned long this_dir = 0;
1500        unsigned int sources = 0;
1501        const char *line_prefix = "";
1502        struct strbuf *msg = NULL;
1503
1504        if (opt->output_prefix) {
1505                msg = opt->output_prefix(opt, opt->output_prefix_data);
1506                line_prefix = msg->buf;
1507        }
1508
1509        while (dir->nr) {
1510                struct dirstat_file *f = dir->files;
1511                int namelen = strlen(f->name);
1512                unsigned long this;
1513                char *slash;
1514
1515                if (namelen < baselen)
1516                        break;
1517                if (memcmp(f->name, base, baselen))
1518                        break;
1519                slash = strchr(f->name + baselen, '/');
1520                if (slash) {
1521                        int newbaselen = slash + 1 - f->name;
1522                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1523                        sources++;
1524                } else {
1525                        this = f->changed;
1526                        dir->files++;
1527                        dir->nr--;
1528                        sources += 2;
1529                }
1530                this_dir += this;
1531        }
1532
1533        /*
1534         * We don't report dirstat's for
1535         *  - the top level
1536         *  - or cases where everything came from a single directory
1537         *    under this directory (sources == 1).
1538         */
1539        if (baselen && sources != 1) {
1540                if (this_dir) {
1541                        int permille = this_dir * 1000 / changed;
1542                        int percent = permille / 10;
1543                        if (percent >= dir->percent) {
1544                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1545                                        percent, permille % 10, baselen, base);
1546                                if (!dir->cumulative)
1547                                        return 0;
1548                        }
1549                }
1550        }
1551        return this_dir;
1552}
1553
1554static int dirstat_compare(const void *_a, const void *_b)
1555{
1556        const struct dirstat_file *a = _a;
1557        const struct dirstat_file *b = _b;
1558        return strcmp(a->name, b->name);
1559}
1560
1561static void show_dirstat(struct diff_options *options)
1562{
1563        int i;
1564        unsigned long changed;
1565        struct dirstat_dir dir;
1566        struct diff_queue_struct *q = &diff_queued_diff;
1567
1568        dir.files = NULL;
1569        dir.alloc = 0;
1570        dir.nr = 0;
1571        dir.percent = options->dirstat_percent;
1572        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1573
1574        changed = 0;
1575        for (i = 0; i < q->nr; i++) {
1576                struct diff_filepair *p = q->queue[i];
1577                const char *name;
1578                unsigned long copied, added, damage;
1579                int content_changed;
1580
1581                name = p->two->path ? p->two->path : p->one->path;
1582
1583                if (p->one->sha1_valid && p->two->sha1_valid)
1584                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1585                else
1586                        content_changed = 1;
1587
1588                if (!content_changed) {
1589                        /*
1590                         * The SHA1 has not changed, so pre-/post-content is
1591                         * identical. We can therefore skip looking at the
1592                         * file contents altogether.
1593                         */
1594                        damage = 0;
1595                        goto found_damage;
1596                }
1597
1598                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1599                        /*
1600                         * In --dirstat-by-file mode, we don't really need to
1601                         * look at the actual file contents at all.
1602                         * The fact that the SHA1 changed is enough for us to
1603                         * add this file to the list of results
1604                         * (with each file contributing equal damage).
1605                         */
1606                        damage = 1;
1607                        goto found_damage;
1608                }
1609
1610                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1611                        diff_populate_filespec(p->one, 0);
1612                        diff_populate_filespec(p->two, 0);
1613                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1614                                               &copied, &added);
1615                        diff_free_filespec_data(p->one);
1616                        diff_free_filespec_data(p->two);
1617                } else if (DIFF_FILE_VALID(p->one)) {
1618                        diff_populate_filespec(p->one, 1);
1619                        copied = added = 0;
1620                        diff_free_filespec_data(p->one);
1621                } else if (DIFF_FILE_VALID(p->two)) {
1622                        diff_populate_filespec(p->two, 1);
1623                        copied = 0;
1624                        added = p->two->size;
1625                        diff_free_filespec_data(p->two);
1626                } else
1627                        continue;
1628
1629                /*
1630                 * Original minus copied is the removed material,
1631                 * added is the new material.  They are both damages
1632                 * made to the preimage.
1633                 * If the resulting damage is zero, we know that
1634                 * diffcore_count_changes() considers the two entries to
1635                 * be identical, but since content_changed is true, we
1636                 * know that there must have been _some_ kind of change,
1637                 * so we force all entries to have damage > 0.
1638                 */
1639                damage = (p->one->size - copied) + added;
1640                if (!damage)
1641                        damage = 1;
1642
1643found_damage:
1644                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1645                dir.files[dir.nr].name = name;
1646                dir.files[dir.nr].changed = damage;
1647                changed += damage;
1648                dir.nr++;
1649        }
1650
1651        /* This can happen even with many files, if everything was renames */
1652        if (!changed)
1653                return;
1654
1655        /* Show all directories with more than x% of the changes */
1656        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1657        gather_dirstat(options, &dir, changed, "", 0);
1658}
1659
1660static void free_diffstat_info(struct diffstat_t *diffstat)
1661{
1662        int i;
1663        for (i = 0; i < diffstat->nr; i++) {
1664                struct diffstat_file *f = diffstat->files[i];
1665                if (f->name != f->print_name)
1666                        free(f->print_name);
1667                free(f->name);
1668                free(f->from_name);
1669                free(f);
1670        }
1671        free(diffstat->files);
1672}
1673
1674struct checkdiff_t {
1675        const char *filename;
1676        int lineno;
1677        int conflict_marker_size;
1678        struct diff_options *o;
1679        unsigned ws_rule;
1680        unsigned status;
1681};
1682
1683static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1684{
1685        char firstchar;
1686        int cnt;
1687
1688        if (len < marker_size + 1)
1689                return 0;
1690        firstchar = line[0];
1691        switch (firstchar) {
1692        case '=': case '>': case '<': case '|':
1693                break;
1694        default:
1695                return 0;
1696        }
1697        for (cnt = 1; cnt < marker_size; cnt++)
1698                if (line[cnt] != firstchar)
1699                        return 0;
1700        /* line[1] thru line[marker_size-1] are same as firstchar */
1701        if (len < marker_size + 1 || !isspace(line[marker_size]))
1702                return 0;
1703        return 1;
1704}
1705
1706static void checkdiff_consume(void *priv, char *line, unsigned long len)
1707{
1708        struct checkdiff_t *data = priv;
1709        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1710        int marker_size = data->conflict_marker_size;
1711        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1712        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1713        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1714        char *err;
1715        char *line_prefix = "";
1716        struct strbuf *msgbuf;
1717
1718        assert(data->o);
1719        if (data->o->output_prefix) {
1720                msgbuf = data->o->output_prefix(data->o,
1721                        data->o->output_prefix_data);
1722                line_prefix = msgbuf->buf;
1723        }
1724
1725        if (line[0] == '+') {
1726                unsigned bad;
1727                data->lineno++;
1728                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1729                        data->status |= 1;
1730                        fprintf(data->o->file,
1731                                "%s%s:%d: leftover conflict marker\n",
1732                                line_prefix, data->filename, data->lineno);
1733                }
1734                bad = ws_check(line + 1, len - 1, data->ws_rule);
1735                if (!bad)
1736                        return;
1737                data->status |= bad;
1738                err = whitespace_error_string(bad);
1739                fprintf(data->o->file, "%s%s:%d: %s.\n",
1740                        line_prefix, data->filename, data->lineno, err);
1741                free(err);
1742                emit_line(data->o, set, reset, line, 1);
1743                ws_check_emit(line + 1, len - 1, data->ws_rule,
1744                              data->o->file, set, reset, ws);
1745        } else if (line[0] == ' ') {
1746                data->lineno++;
1747        } else if (line[0] == '@') {
1748                char *plus = strchr(line, '+');
1749                if (plus)
1750                        data->lineno = strtol(plus, NULL, 10) - 1;
1751                else
1752                        die("invalid diff");
1753        }
1754}
1755
1756static unsigned char *deflate_it(char *data,
1757                                 unsigned long size,
1758                                 unsigned long *result_size)
1759{
1760        int bound;
1761        unsigned char *deflated;
1762        z_stream stream;
1763
1764        memset(&stream, 0, sizeof(stream));
1765        deflateInit(&stream, zlib_compression_level);
1766        bound = deflateBound(&stream, size);
1767        deflated = xmalloc(bound);
1768        stream.next_out = deflated;
1769        stream.avail_out = bound;
1770
1771        stream.next_in = (unsigned char *)data;
1772        stream.avail_in = size;
1773        while (deflate(&stream, Z_FINISH) == Z_OK)
1774                ; /* nothing */
1775        deflateEnd(&stream);
1776        *result_size = stream.total_out;
1777        return deflated;
1778}
1779
1780static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1781{
1782        void *cp;
1783        void *delta;
1784        void *deflated;
1785        void *data;
1786        unsigned long orig_size;
1787        unsigned long delta_size;
1788        unsigned long deflate_size;
1789        unsigned long data_size;
1790
1791        /* We could do deflated delta, or we could do just deflated two,
1792         * whichever is smaller.
1793         */
1794        delta = NULL;
1795        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1796        if (one->size && two->size) {
1797                delta = diff_delta(one->ptr, one->size,
1798                                   two->ptr, two->size,
1799                                   &delta_size, deflate_size);
1800                if (delta) {
1801                        void *to_free = delta;
1802                        orig_size = delta_size;
1803                        delta = deflate_it(delta, delta_size, &delta_size);
1804                        free(to_free);
1805                }
1806        }
1807
1808        if (delta && delta_size < deflate_size) {
1809                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1810                free(deflated);
1811                data = delta;
1812                data_size = delta_size;
1813        }
1814        else {
1815                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1816                free(delta);
1817                data = deflated;
1818                data_size = deflate_size;
1819        }
1820
1821        /* emit data encoded in base85 */
1822        cp = data;
1823        while (data_size) {
1824                int bytes = (52 < data_size) ? 52 : data_size;
1825                char line[70];
1826                data_size -= bytes;
1827                if (bytes <= 26)
1828                        line[0] = bytes + 'A' - 1;
1829                else
1830                        line[0] = bytes - 26 + 'a' - 1;
1831                encode_85(line + 1, cp, bytes);
1832                cp = (char *) cp + bytes;
1833                fprintf(file, "%s", prefix);
1834                fputs(line, file);
1835                fputc('\n', file);
1836        }
1837        fprintf(file, "%s\n", prefix);
1838        free(data);
1839}
1840
1841static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1842{
1843        fprintf(file, "%sGIT binary patch\n", prefix);
1844        emit_binary_diff_body(file, one, two, prefix);
1845        emit_binary_diff_body(file, two, one, prefix);
1846}
1847
1848static void diff_filespec_load_driver(struct diff_filespec *one)
1849{
1850        /* Use already-loaded driver */
1851        if (one->driver)
1852                return;
1853
1854        if (S_ISREG(one->mode))
1855                one->driver = userdiff_find_by_path(one->path);
1856
1857        /* Fallback to default settings */
1858        if (!one->driver)
1859                one->driver = userdiff_find_by_name("default");
1860}
1861
1862int diff_filespec_is_binary(struct diff_filespec *one)
1863{
1864        if (one->is_binary == -1) {
1865                diff_filespec_load_driver(one);
1866                if (one->driver->binary != -1)
1867                        one->is_binary = one->driver->binary;
1868                else {
1869                        if (!one->data && DIFF_FILE_VALID(one))
1870                                diff_populate_filespec(one, 0);
1871                        if (one->data)
1872                                one->is_binary = buffer_is_binary(one->data,
1873                                                one->size);
1874                        if (one->is_binary == -1)
1875                                one->is_binary = 0;
1876                }
1877        }
1878        return one->is_binary;
1879}
1880
1881static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1882{
1883        diff_filespec_load_driver(one);
1884        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1885}
1886
1887static const char *userdiff_word_regex(struct diff_filespec *one)
1888{
1889        diff_filespec_load_driver(one);
1890        return one->driver->word_regex;
1891}
1892
1893void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1894{
1895        if (!options->a_prefix)
1896                options->a_prefix = a;
1897        if (!options->b_prefix)
1898                options->b_prefix = b;
1899}
1900
1901struct userdiff_driver *get_textconv(struct diff_filespec *one)
1902{
1903        if (!DIFF_FILE_VALID(one))
1904                return NULL;
1905
1906        diff_filespec_load_driver(one);
1907        if (!one->driver->textconv)
1908                return NULL;
1909
1910        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1911                struct notes_cache *c = xmalloc(sizeof(*c));
1912                struct strbuf name = STRBUF_INIT;
1913
1914                strbuf_addf(&name, "textconv/%s", one->driver->name);
1915                notes_cache_init(c, name.buf, one->driver->textconv);
1916                one->driver->textconv_cache = c;
1917        }
1918
1919        return one->driver;
1920}
1921
1922static void builtin_diff(const char *name_a,
1923                         const char *name_b,
1924                         struct diff_filespec *one,
1925                         struct diff_filespec *two,
1926                         const char *xfrm_msg,
1927                         int must_show_header,
1928                         struct diff_options *o,
1929                         int complete_rewrite)
1930{
1931        mmfile_t mf1, mf2;
1932        const char *lbl[2];
1933        char *a_one, *b_two;
1934        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1935        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1936        const char *a_prefix, *b_prefix;
1937        struct userdiff_driver *textconv_one = NULL;
1938        struct userdiff_driver *textconv_two = NULL;
1939        struct strbuf header = STRBUF_INIT;
1940        struct strbuf *msgbuf;
1941        char *line_prefix = "";
1942
1943        if (o->output_prefix) {
1944                msgbuf = o->output_prefix(o, o->output_prefix_data);
1945                line_prefix = msgbuf->buf;
1946        }
1947
1948        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1949                        (!one->mode || S_ISGITLINK(one->mode)) &&
1950                        (!two->mode || S_ISGITLINK(two->mode))) {
1951                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1952                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1953                show_submodule_summary(o->file, one ? one->path : two->path,
1954                                one->sha1, two->sha1, two->dirty_submodule,
1955                                del, add, reset);
1956                return;
1957        }
1958
1959        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1960                textconv_one = get_textconv(one);
1961                textconv_two = get_textconv(two);
1962        }
1963
1964        diff_set_mnemonic_prefix(o, "a/", "b/");
1965        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1966                a_prefix = o->b_prefix;
1967                b_prefix = o->a_prefix;
1968        } else {
1969                a_prefix = o->a_prefix;
1970                b_prefix = o->b_prefix;
1971        }
1972
1973        /* Never use a non-valid filename anywhere if at all possible */
1974        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1975        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1976
1977        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1978        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1979        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1980        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1981        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1982        if (lbl[0][0] == '/') {
1983                /* /dev/null */
1984                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1985                if (xfrm_msg)
1986                        strbuf_addstr(&header, xfrm_msg);
1987                must_show_header = 1;
1988        }
1989        else if (lbl[1][0] == '/') {
1990                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1991                if (xfrm_msg)
1992                        strbuf_addstr(&header, xfrm_msg);
1993                must_show_header = 1;
1994        }
1995        else {
1996                if (one->mode != two->mode) {
1997                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1998                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1999                        must_show_header = 1;
2000                }
2001                if (xfrm_msg)
2002                        strbuf_addstr(&header, xfrm_msg);
2003
2004                /*
2005                 * we do not run diff between different kind
2006                 * of objects.
2007                 */
2008                if ((one->mode ^ two->mode) & S_IFMT)
2009                        goto free_ab_and_return;
2010                if (complete_rewrite &&
2011                    (textconv_one || !diff_filespec_is_binary(one)) &&
2012                    (textconv_two || !diff_filespec_is_binary(two))) {
2013                        fprintf(o->file, "%s", header.buf);
2014                        strbuf_reset(&header);
2015                        emit_rewrite_diff(name_a, name_b, one, two,
2016                                                textconv_one, textconv_two, o);
2017                        o->found_changes = 1;
2018                        goto free_ab_and_return;
2019                }
2020        }
2021
2022        if (o->irreversible_delete && lbl[1][0] == '/') {
2023                fprintf(o->file, "%s", header.buf);
2024                strbuf_reset(&header);
2025                goto free_ab_and_return;
2026        } else if (!DIFF_OPT_TST(o, TEXT) &&
2027            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2028              (!textconv_two && diff_filespec_is_binary(two)) )) {
2029                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2030                        die("unable to read files to diff");
2031                /* Quite common confusing case */
2032                if (mf1.size == mf2.size &&
2033                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2034                        if (must_show_header)
2035                                fprintf(o->file, "%s", header.buf);
2036                        goto free_ab_and_return;
2037                }
2038                fprintf(o->file, "%s", header.buf);
2039                strbuf_reset(&header);
2040                if (DIFF_OPT_TST(o, BINARY))
2041                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2042                else
2043                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2044                                line_prefix, lbl[0], lbl[1]);
2045                o->found_changes = 1;
2046        } else {
2047                /* Crazy xdl interfaces.. */
2048                const char *diffopts = getenv("GIT_DIFF_OPTS");
2049                xpparam_t xpp;
2050                xdemitconf_t xecfg;
2051                struct emit_callback ecbdata;
2052                const struct userdiff_funcname *pe;
2053
2054                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2055                        fprintf(o->file, "%s", header.buf);
2056                        strbuf_reset(&header);
2057                }
2058
2059                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2060                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2061
2062                pe = diff_funcname_pattern(one);
2063                if (!pe)
2064                        pe = diff_funcname_pattern(two);
2065
2066                memset(&xpp, 0, sizeof(xpp));
2067                memset(&xecfg, 0, sizeof(xecfg));
2068                memset(&ecbdata, 0, sizeof(ecbdata));
2069                ecbdata.label_path = lbl;
2070                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2071                ecbdata.found_changesp = &o->found_changes;
2072                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2073                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2074                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2075                ecbdata.opt = o;
2076                ecbdata.header = header.len ? &header : NULL;
2077                xpp.flags = o->xdl_opts;
2078                xecfg.ctxlen = o->context;
2079                xecfg.interhunkctxlen = o->interhunkcontext;
2080                xecfg.flags = XDL_EMIT_FUNCNAMES;
2081                if (pe)
2082                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2083                if (!diffopts)
2084                        ;
2085                else if (!prefixcmp(diffopts, "--unified="))
2086                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2087                else if (!prefixcmp(diffopts, "-u"))
2088                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2089                if (o->word_diff) {
2090                        int i;
2091
2092                        ecbdata.diff_words =
2093                                xcalloc(1, sizeof(struct diff_words_data));
2094                        ecbdata.diff_words->type = o->word_diff;
2095                        ecbdata.diff_words->opt = o;
2096                        if (!o->word_regex)
2097                                o->word_regex = userdiff_word_regex(one);
2098                        if (!o->word_regex)
2099                                o->word_regex = userdiff_word_regex(two);
2100                        if (!o->word_regex)
2101                                o->word_regex = diff_word_regex_cfg;
2102                        if (o->word_regex) {
2103                                ecbdata.diff_words->word_regex = (regex_t *)
2104                                        xmalloc(sizeof(regex_t));
2105                                if (regcomp(ecbdata.diff_words->word_regex,
2106                                                o->word_regex,
2107                                                REG_EXTENDED | REG_NEWLINE))
2108                                        die ("Invalid regular expression: %s",
2109                                                        o->word_regex);
2110                        }
2111                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2112                                if (o->word_diff == diff_words_styles[i].type) {
2113                                        ecbdata.diff_words->style =
2114                                                &diff_words_styles[i];
2115                                        break;
2116                                }
2117                        }
2118                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2119                                struct diff_words_style *st = ecbdata.diff_words->style;
2120                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2121                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2122                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2123                        }
2124                }
2125                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2126                              &xpp, &xecfg);
2127                if (o->word_diff)
2128                        free_diff_words_data(&ecbdata);
2129                if (textconv_one)
2130                        free(mf1.ptr);
2131                if (textconv_two)
2132                        free(mf2.ptr);
2133                xdiff_clear_find_func(&xecfg);
2134        }
2135
2136 free_ab_and_return:
2137        strbuf_release(&header);
2138        diff_free_filespec_data(one);
2139        diff_free_filespec_data(two);
2140        free(a_one);
2141        free(b_two);
2142        return;
2143}
2144
2145static void builtin_diffstat(const char *name_a, const char *name_b,
2146                             struct diff_filespec *one,
2147                             struct diff_filespec *two,
2148                             struct diffstat_t *diffstat,
2149                             struct diff_options *o,
2150                             int complete_rewrite)
2151{
2152        mmfile_t mf1, mf2;
2153        struct diffstat_file *data;
2154
2155        data = diffstat_add(diffstat, name_a, name_b);
2156
2157        if (!one || !two) {
2158                data->is_unmerged = 1;
2159                return;
2160        }
2161
2162        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2163                data->is_binary = 1;
2164                data->added = diff_filespec_size(two);
2165                data->deleted = diff_filespec_size(one);
2166        }
2167
2168        else if (complete_rewrite) {
2169                diff_populate_filespec(one, 0);
2170                diff_populate_filespec(two, 0);
2171                data->deleted = count_lines(one->data, one->size);
2172                data->added = count_lines(two->data, two->size);
2173        }
2174
2175        else {
2176                /* Crazy xdl interfaces.. */
2177                xpparam_t xpp;
2178                xdemitconf_t xecfg;
2179
2180                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2181                        die("unable to read files to diff");
2182
2183                memset(&xpp, 0, sizeof(xpp));
2184                memset(&xecfg, 0, sizeof(xecfg));
2185                xpp.flags = o->xdl_opts;
2186                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2187                              &xpp, &xecfg);
2188        }
2189
2190        diff_free_filespec_data(one);
2191        diff_free_filespec_data(two);
2192}
2193
2194static void builtin_checkdiff(const char *name_a, const char *name_b,
2195                              const char *attr_path,
2196                              struct diff_filespec *one,
2197                              struct diff_filespec *two,
2198                              struct diff_options *o)
2199{
2200        mmfile_t mf1, mf2;
2201        struct checkdiff_t data;
2202
2203        if (!two)
2204                return;
2205
2206        memset(&data, 0, sizeof(data));
2207        data.filename = name_b ? name_b : name_a;
2208        data.lineno = 0;
2209        data.o = o;
2210        data.ws_rule = whitespace_rule(attr_path);
2211        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2212
2213        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2214                die("unable to read files to diff");
2215
2216        /*
2217         * All the other codepaths check both sides, but not checking
2218         * the "old" side here is deliberate.  We are checking the newly
2219         * introduced changes, and as long as the "new" side is text, we
2220         * can and should check what it introduces.
2221         */
2222        if (diff_filespec_is_binary(two))
2223                goto free_and_return;
2224        else {
2225                /* Crazy xdl interfaces.. */
2226                xpparam_t xpp;
2227                xdemitconf_t xecfg;
2228
2229                memset(&xpp, 0, sizeof(xpp));
2230                memset(&xecfg, 0, sizeof(xecfg));
2231                xecfg.ctxlen = 1; /* at least one context line */
2232                xpp.flags = 0;
2233                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2234                              &xpp, &xecfg);
2235
2236                if (data.ws_rule & WS_BLANK_AT_EOF) {
2237                        struct emit_callback ecbdata;
2238                        int blank_at_eof;
2239
2240                        ecbdata.ws_rule = data.ws_rule;
2241                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2242                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2243
2244                        if (blank_at_eof) {
2245                                static char *err;
2246                                if (!err)
2247                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2248                                fprintf(o->file, "%s:%d: %s.\n",
2249                                        data.filename, blank_at_eof, err);
2250                                data.status = 1; /* report errors */
2251                        }
2252                }
2253        }
2254 free_and_return:
2255        diff_free_filespec_data(one);
2256        diff_free_filespec_data(two);
2257        if (data.status)
2258                DIFF_OPT_SET(o, CHECK_FAILED);
2259}
2260
2261struct diff_filespec *alloc_filespec(const char *path)
2262{
2263        int namelen = strlen(path);
2264        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2265
2266        memset(spec, 0, sizeof(*spec));
2267        spec->path = (char *)(spec + 1);
2268        memcpy(spec->path, path, namelen+1);
2269        spec->count = 1;
2270        spec->is_binary = -1;
2271        return spec;
2272}
2273
2274void free_filespec(struct diff_filespec *spec)
2275{
2276        if (!--spec->count) {
2277                diff_free_filespec_data(spec);
2278                free(spec);
2279        }
2280}
2281
2282void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2283                   unsigned short mode)
2284{
2285        if (mode) {
2286                spec->mode = canon_mode(mode);
2287                hashcpy(spec->sha1, sha1);
2288                spec->sha1_valid = !is_null_sha1(sha1);
2289        }
2290}
2291
2292/*
2293 * Given a name and sha1 pair, if the index tells us the file in
2294 * the work tree has that object contents, return true, so that
2295 * prepare_temp_file() does not have to inflate and extract.
2296 */
2297static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2298{
2299        struct cache_entry *ce;
2300        struct stat st;
2301        int pos, len;
2302
2303        /*
2304         * We do not read the cache ourselves here, because the
2305         * benchmark with my previous version that always reads cache
2306         * shows that it makes things worse for diff-tree comparing
2307         * two linux-2.6 kernel trees in an already checked out work
2308         * tree.  This is because most diff-tree comparisons deal with
2309         * only a small number of files, while reading the cache is
2310         * expensive for a large project, and its cost outweighs the
2311         * savings we get by not inflating the object to a temporary
2312         * file.  Practically, this code only helps when we are used
2313         * by diff-cache --cached, which does read the cache before
2314         * calling us.
2315         */
2316        if (!active_cache)
2317                return 0;
2318
2319        /* We want to avoid the working directory if our caller
2320         * doesn't need the data in a normal file, this system
2321         * is rather slow with its stat/open/mmap/close syscalls,
2322         * and the object is contained in a pack file.  The pack
2323         * is probably already open and will be faster to obtain
2324         * the data through than the working directory.  Loose
2325         * objects however would tend to be slower as they need
2326         * to be individually opened and inflated.
2327         */
2328        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2329                return 0;
2330
2331        len = strlen(name);
2332        pos = cache_name_pos(name, len);
2333        if (pos < 0)
2334                return 0;
2335        ce = active_cache[pos];
2336
2337        /*
2338         * This is not the sha1 we are looking for, or
2339         * unreusable because it is not a regular file.
2340         */
2341        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2342                return 0;
2343
2344        /*
2345         * If ce is marked as "assume unchanged", there is no
2346         * guarantee that work tree matches what we are looking for.
2347         */
2348        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2349                return 0;
2350
2351        /*
2352         * If ce matches the file in the work tree, we can reuse it.
2353         */
2354        if (ce_uptodate(ce) ||
2355            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2356                return 1;
2357
2358        return 0;
2359}
2360
2361static int populate_from_stdin(struct diff_filespec *s)
2362{
2363        struct strbuf buf = STRBUF_INIT;
2364        size_t size = 0;
2365
2366        if (strbuf_read(&buf, 0, 0) < 0)
2367                return error("error while reading from stdin %s",
2368                                     strerror(errno));
2369
2370        s->should_munmap = 0;
2371        s->data = strbuf_detach(&buf, &size);
2372        s->size = size;
2373        s->should_free = 1;
2374        return 0;
2375}
2376
2377static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2378{
2379        int len;
2380        char *data = xmalloc(100), *dirty = "";
2381
2382        /* Are we looking at the work tree? */
2383        if (s->dirty_submodule)
2384                dirty = "-dirty";
2385
2386        len = snprintf(data, 100,
2387                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2388        s->data = data;
2389        s->size = len;
2390        s->should_free = 1;
2391        if (size_only) {
2392                s->data = NULL;
2393                free(data);
2394        }
2395        return 0;
2396}
2397
2398/*
2399 * While doing rename detection and pickaxe operation, we may need to
2400 * grab the data for the blob (or file) for our own in-core comparison.
2401 * diff_filespec has data and size fields for this purpose.
2402 */
2403int diff_populate_filespec(struct diff_filespec *s, int size_only)
2404{
2405        int err = 0;
2406        if (!DIFF_FILE_VALID(s))
2407                die("internal error: asking to populate invalid file.");
2408        if (S_ISDIR(s->mode))
2409                return -1;
2410
2411        if (s->data)
2412                return 0;
2413
2414        if (size_only && 0 < s->size)
2415                return 0;
2416
2417        if (S_ISGITLINK(s->mode))
2418                return diff_populate_gitlink(s, size_only);
2419
2420        if (!s->sha1_valid ||
2421            reuse_worktree_file(s->path, s->sha1, 0)) {
2422                struct strbuf buf = STRBUF_INIT;
2423                struct stat st;
2424                int fd;
2425
2426                if (!strcmp(s->path, "-"))
2427                        return populate_from_stdin(s);
2428
2429                if (lstat(s->path, &st) < 0) {
2430                        if (errno == ENOENT) {
2431                        err_empty:
2432                                err = -1;
2433                        empty:
2434                                s->data = (char *)"";
2435                                s->size = 0;
2436                                return err;
2437                        }
2438                }
2439                s->size = xsize_t(st.st_size);
2440                if (!s->size)
2441                        goto empty;
2442                if (S_ISLNK(st.st_mode)) {
2443                        struct strbuf sb = STRBUF_INIT;
2444
2445                        if (strbuf_readlink(&sb, s->path, s->size))
2446                                goto err_empty;
2447                        s->size = sb.len;
2448                        s->data = strbuf_detach(&sb, NULL);
2449                        s->should_free = 1;
2450                        return 0;
2451                }
2452                if (size_only)
2453                        return 0;
2454                fd = open(s->path, O_RDONLY);
2455                if (fd < 0)
2456                        goto err_empty;
2457                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2458                close(fd);
2459                s->should_munmap = 1;
2460
2461                /*
2462                 * Convert from working tree format to canonical git format
2463                 */
2464                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2465                        size_t size = 0;
2466                        munmap(s->data, s->size);
2467                        s->should_munmap = 0;
2468                        s->data = strbuf_detach(&buf, &size);
2469                        s->size = size;
2470                        s->should_free = 1;
2471                }
2472        }
2473        else {
2474                enum object_type type;
2475                if (size_only) {
2476                        type = sha1_object_info(s->sha1, &s->size);
2477                        if (type < 0)
2478                                die("unable to read %s", sha1_to_hex(s->sha1));
2479                } else {
2480                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2481                        if (!s->data)
2482                                die("unable to read %s", sha1_to_hex(s->sha1));
2483                        s->should_free = 1;
2484                }
2485        }
2486        return 0;
2487}
2488
2489void diff_free_filespec_blob(struct diff_filespec *s)
2490{
2491        if (s->should_free)
2492                free(s->data);
2493        else if (s->should_munmap)
2494                munmap(s->data, s->size);
2495
2496        if (s->should_free || s->should_munmap) {
2497                s->should_free = s->should_munmap = 0;
2498                s->data = NULL;
2499        }
2500}
2501
2502void diff_free_filespec_data(struct diff_filespec *s)
2503{
2504        diff_free_filespec_blob(s);
2505        free(s->cnt_data);
2506        s->cnt_data = NULL;
2507}
2508
2509static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2510                           void *blob,
2511                           unsigned long size,
2512                           const unsigned char *sha1,
2513                           int mode)
2514{
2515        int fd;
2516        struct strbuf buf = STRBUF_INIT;
2517        struct strbuf template = STRBUF_INIT;
2518        char *path_dup = xstrdup(path);
2519        const char *base = basename(path_dup);
2520
2521        /* Generate "XXXXXX_basename.ext" */
2522        strbuf_addstr(&template, "XXXXXX_");
2523        strbuf_addstr(&template, base);
2524
2525        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2526                        strlen(base) + 1);
2527        if (fd < 0)
2528                die_errno("unable to create temp-file");
2529        if (convert_to_working_tree(path,
2530                        (const char *)blob, (size_t)size, &buf)) {
2531                blob = buf.buf;
2532                size = buf.len;
2533        }
2534        if (write_in_full(fd, blob, size) != size)
2535                die_errno("unable to write temp-file");
2536        close(fd);
2537        temp->name = temp->tmp_path;
2538        strcpy(temp->hex, sha1_to_hex(sha1));
2539        temp->hex[40] = 0;
2540        sprintf(temp->mode, "%06o", mode);
2541        strbuf_release(&buf);
2542        strbuf_release(&template);
2543        free(path_dup);
2544}
2545
2546static struct diff_tempfile *prepare_temp_file(const char *name,
2547                struct diff_filespec *one)
2548{
2549        struct diff_tempfile *temp = claim_diff_tempfile();
2550
2551        if (!DIFF_FILE_VALID(one)) {
2552        not_a_valid_file:
2553                /* A '-' entry produces this for file-2, and
2554                 * a '+' entry produces this for file-1.
2555                 */
2556                temp->name = "/dev/null";
2557                strcpy(temp->hex, ".");
2558                strcpy(temp->mode, ".");
2559                return temp;
2560        }
2561
2562        if (!remove_tempfile_installed) {
2563                atexit(remove_tempfile);
2564                sigchain_push_common(remove_tempfile_on_signal);
2565                remove_tempfile_installed = 1;
2566        }
2567
2568        if (!one->sha1_valid ||
2569            reuse_worktree_file(name, one->sha1, 1)) {
2570                struct stat st;
2571                if (lstat(name, &st) < 0) {
2572                        if (errno == ENOENT)
2573                                goto not_a_valid_file;
2574                        die_errno("stat(%s)", name);
2575                }
2576                if (S_ISLNK(st.st_mode)) {
2577                        struct strbuf sb = STRBUF_INIT;
2578                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2579                                die_errno("readlink(%s)", name);
2580                        prep_temp_blob(name, temp, sb.buf, sb.len,
2581                                       (one->sha1_valid ?
2582                                        one->sha1 : null_sha1),
2583                                       (one->sha1_valid ?
2584                                        one->mode : S_IFLNK));
2585                        strbuf_release(&sb);
2586                }
2587                else {
2588                        /* we can borrow from the file in the work tree */
2589                        temp->name = name;
2590                        if (!one->sha1_valid)
2591                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2592                        else
2593                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2594                        /* Even though we may sometimes borrow the
2595                         * contents from the work tree, we always want
2596                         * one->mode.  mode is trustworthy even when
2597                         * !(one->sha1_valid), as long as
2598                         * DIFF_FILE_VALID(one).
2599                         */
2600                        sprintf(temp->mode, "%06o", one->mode);
2601                }
2602                return temp;
2603        }
2604        else {
2605                if (diff_populate_filespec(one, 0))
2606                        die("cannot read data blob for %s", one->path);
2607                prep_temp_blob(name, temp, one->data, one->size,
2608                               one->sha1, one->mode);
2609        }
2610        return temp;
2611}
2612
2613/* An external diff command takes:
2614 *
2615 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2616 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2617 *
2618 */
2619static void run_external_diff(const char *pgm,
2620                              const char *name,
2621                              const char *other,
2622                              struct diff_filespec *one,
2623                              struct diff_filespec *two,
2624                              const char *xfrm_msg,
2625                              int complete_rewrite)
2626{
2627        const char *spawn_arg[10];
2628        int retval;
2629        const char **arg = &spawn_arg[0];
2630
2631        if (one && two) {
2632                struct diff_tempfile *temp_one, *temp_two;
2633                const char *othername = (other ? other : name);
2634                temp_one = prepare_temp_file(name, one);
2635                temp_two = prepare_temp_file(othername, two);
2636                *arg++ = pgm;
2637                *arg++ = name;
2638                *arg++ = temp_one->name;
2639                *arg++ = temp_one->hex;
2640                *arg++ = temp_one->mode;
2641                *arg++ = temp_two->name;
2642                *arg++ = temp_two->hex;
2643                *arg++ = temp_two->mode;
2644                if (other) {
2645                        *arg++ = other;
2646                        *arg++ = xfrm_msg;
2647                }
2648        } else {
2649                *arg++ = pgm;
2650                *arg++ = name;
2651        }
2652        *arg = NULL;
2653        fflush(NULL);
2654        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2655        remove_tempfile();
2656        if (retval) {
2657                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2658                exit(1);
2659        }
2660}
2661
2662static int similarity_index(struct diff_filepair *p)
2663{
2664        return p->score * 100 / MAX_SCORE;
2665}
2666
2667static void fill_metainfo(struct strbuf *msg,
2668                          const char *name,
2669                          const char *other,
2670                          struct diff_filespec *one,
2671                          struct diff_filespec *two,
2672                          struct diff_options *o,
2673                          struct diff_filepair *p,
2674                          int *must_show_header,
2675                          int use_color)
2676{
2677        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2678        const char *reset = diff_get_color(use_color, DIFF_RESET);
2679        struct strbuf *msgbuf;
2680        char *line_prefix = "";
2681
2682        *must_show_header = 1;
2683        if (o->output_prefix) {
2684                msgbuf = o->output_prefix(o, o->output_prefix_data);
2685                line_prefix = msgbuf->buf;
2686        }
2687        strbuf_init(msg, PATH_MAX * 2 + 300);
2688        switch (p->status) {
2689        case DIFF_STATUS_COPIED:
2690                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2691                            line_prefix, set, similarity_index(p));
2692                strbuf_addf(msg, "%s\n%s%scopy from ",
2693                            reset,  line_prefix, set);
2694                quote_c_style(name, msg, NULL, 0);
2695                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2696                quote_c_style(other, msg, NULL, 0);
2697                strbuf_addf(msg, "%s\n", reset);
2698                break;
2699        case DIFF_STATUS_RENAMED:
2700                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2701                            line_prefix, set, similarity_index(p));
2702                strbuf_addf(msg, "%s\n%s%srename from ",
2703                            reset, line_prefix, set);
2704                quote_c_style(name, msg, NULL, 0);
2705                strbuf_addf(msg, "%s\n%s%srename to ",
2706                            reset, line_prefix, set);
2707                quote_c_style(other, msg, NULL, 0);
2708                strbuf_addf(msg, "%s\n", reset);
2709                break;
2710        case DIFF_STATUS_MODIFIED:
2711                if (p->score) {
2712                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2713                                    line_prefix,
2714                                    set, similarity_index(p), reset);
2715                        break;
2716                }
2717                /* fallthru */
2718        default:
2719                *must_show_header = 0;
2720        }
2721        if (one && two && hashcmp(one->sha1, two->sha1)) {
2722                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2723
2724                if (DIFF_OPT_TST(o, BINARY)) {
2725                        mmfile_t mf;
2726                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2727                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2728                                abbrev = 40;
2729                }
2730                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2731                            find_unique_abbrev(one->sha1, abbrev));
2732                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2733                if (one->mode == two->mode)
2734                        strbuf_addf(msg, " %06o", one->mode);
2735                strbuf_addf(msg, "%s\n", reset);
2736        }
2737}
2738
2739static void run_diff_cmd(const char *pgm,
2740                         const char *name,
2741                         const char *other,
2742                         const char *attr_path,
2743                         struct diff_filespec *one,
2744                         struct diff_filespec *two,
2745                         struct strbuf *msg,
2746                         struct diff_options *o,
2747                         struct diff_filepair *p)
2748{
2749        const char *xfrm_msg = NULL;
2750        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2751        int must_show_header = 0;
2752
2753        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2754                pgm = NULL;
2755        else {
2756                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2757                if (drv && drv->external)
2758                        pgm = drv->external;
2759        }
2760
2761        if (msg) {
2762                /*
2763                 * don't use colors when the header is intended for an
2764                 * external diff driver
2765                 */
2766                fill_metainfo(msg, name, other, one, two, o, p,
2767                              &must_show_header,
2768                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2769                xfrm_msg = msg->len ? msg->buf : NULL;
2770        }
2771
2772        if (pgm) {
2773                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2774                                  complete_rewrite);
2775                return;
2776        }
2777        if (one && two)
2778                builtin_diff(name, other ? other : name,
2779                             one, two, xfrm_msg, must_show_header,
2780                             o, complete_rewrite);
2781        else
2782                fprintf(o->file, "* Unmerged path %s\n", name);
2783}
2784
2785static void diff_fill_sha1_info(struct diff_filespec *one)
2786{
2787        if (DIFF_FILE_VALID(one)) {
2788                if (!one->sha1_valid) {
2789                        struct stat st;
2790                        if (!strcmp(one->path, "-")) {
2791                                hashcpy(one->sha1, null_sha1);
2792                                return;
2793                        }
2794                        if (lstat(one->path, &st) < 0)
2795                                die_errno("stat '%s'", one->path);
2796                        if (index_path(one->sha1, one->path, &st, 0))
2797                                die("cannot hash %s", one->path);
2798                }
2799        }
2800        else
2801                hashclr(one->sha1);
2802}
2803
2804static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2805{
2806        /* Strip the prefix but do not molest /dev/null and absolute paths */
2807        if (*namep && **namep != '/') {
2808                *namep += prefix_length;
2809                if (**namep == '/')
2810                        ++*namep;
2811        }
2812        if (*otherp && **otherp != '/') {
2813                *otherp += prefix_length;
2814                if (**otherp == '/')
2815                        ++*otherp;
2816        }
2817}
2818
2819static void run_diff(struct diff_filepair *p, struct diff_options *o)
2820{
2821        const char *pgm = external_diff();
2822        struct strbuf msg;
2823        struct diff_filespec *one = p->one;
2824        struct diff_filespec *two = p->two;
2825        const char *name;
2826        const char *other;
2827        const char *attr_path;
2828
2829        name  = p->one->path;
2830        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2831        attr_path = name;
2832        if (o->prefix_length)
2833                strip_prefix(o->prefix_length, &name, &other);
2834
2835        if (DIFF_PAIR_UNMERGED(p)) {
2836                run_diff_cmd(pgm, name, NULL, attr_path,
2837                             NULL, NULL, NULL, o, p);
2838                return;
2839        }
2840
2841        diff_fill_sha1_info(one);
2842        diff_fill_sha1_info(two);
2843
2844        if (!pgm &&
2845            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2846            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2847                /*
2848                 * a filepair that changes between file and symlink
2849                 * needs to be split into deletion and creation.
2850                 */
2851                struct diff_filespec *null = alloc_filespec(two->path);
2852                run_diff_cmd(NULL, name, other, attr_path,
2853                             one, null, &msg, o, p);
2854                free(null);
2855                strbuf_release(&msg);
2856
2857                null = alloc_filespec(one->path);
2858                run_diff_cmd(NULL, name, other, attr_path,
2859                             null, two, &msg, o, p);
2860                free(null);
2861        }
2862        else
2863                run_diff_cmd(pgm, name, other, attr_path,
2864                             one, two, &msg, o, p);
2865
2866        strbuf_release(&msg);
2867}
2868
2869static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2870                         struct diffstat_t *diffstat)
2871{
2872        const char *name;
2873        const char *other;
2874        int complete_rewrite = 0;
2875
2876        if (DIFF_PAIR_UNMERGED(p)) {
2877                /* unmerged */
2878                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2879                return;
2880        }
2881
2882        name = p->one->path;
2883        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2884
2885        if (o->prefix_length)
2886                strip_prefix(o->prefix_length, &name, &other);
2887
2888        diff_fill_sha1_info(p->one);
2889        diff_fill_sha1_info(p->two);
2890
2891        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2892                complete_rewrite = 1;
2893        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2894}
2895
2896static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2897{
2898        const char *name;
2899        const char *other;
2900        const char *attr_path;
2901
2902        if (DIFF_PAIR_UNMERGED(p)) {
2903                /* unmerged */
2904                return;
2905        }
2906
2907        name = p->one->path;
2908        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2909        attr_path = other ? other : name;
2910
2911        if (o->prefix_length)
2912                strip_prefix(o->prefix_length, &name, &other);
2913
2914        diff_fill_sha1_info(p->one);
2915        diff_fill_sha1_info(p->two);
2916
2917        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2918}
2919
2920void diff_setup(struct diff_options *options)
2921{
2922        memcpy(options, &default_diff_options, sizeof(*options));
2923
2924        options->file = stdout;
2925
2926        options->line_termination = '\n';
2927        options->break_opt = -1;
2928        options->rename_limit = -1;
2929        options->dirstat_percent = 3;
2930        options->context = 3;
2931
2932        options->change = diff_change;
2933        options->add_remove = diff_addremove;
2934        if (diff_use_color_default > 0)
2935                DIFF_OPT_SET(options, COLOR_DIFF);
2936        options->detect_rename = diff_detect_rename_default;
2937
2938        if (diff_no_prefix) {
2939                options->a_prefix = options->b_prefix = "";
2940        } else if (!diff_mnemonic_prefix) {
2941                options->a_prefix = "a/";
2942                options->b_prefix = "b/";
2943        }
2944}
2945
2946int diff_setup_done(struct diff_options *options)
2947{
2948        int count = 0;
2949
2950        if (options->output_format & DIFF_FORMAT_NAME)
2951                count++;
2952        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2953                count++;
2954        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2955                count++;
2956        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2957                count++;
2958        if (count > 1)
2959                die("--name-only, --name-status, --check and -s are mutually exclusive");
2960
2961        /*
2962         * Most of the time we can say "there are changes"
2963         * only by checking if there are changed paths, but
2964         * --ignore-whitespace* options force us to look
2965         * inside contents.
2966         */
2967
2968        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2969            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2970            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2971                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2972        else
2973                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2974
2975        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2976                options->detect_rename = DIFF_DETECT_COPY;
2977
2978        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2979                options->prefix = NULL;
2980        if (options->prefix)
2981                options->prefix_length = strlen(options->prefix);
2982        else
2983                options->prefix_length = 0;
2984
2985        if (options->output_format & (DIFF_FORMAT_NAME |
2986                                      DIFF_FORMAT_NAME_STATUS |
2987                                      DIFF_FORMAT_CHECKDIFF |
2988                                      DIFF_FORMAT_NO_OUTPUT))
2989                options->output_format &= ~(DIFF_FORMAT_RAW |
2990                                            DIFF_FORMAT_NUMSTAT |
2991                                            DIFF_FORMAT_DIFFSTAT |
2992                                            DIFF_FORMAT_SHORTSTAT |
2993                                            DIFF_FORMAT_DIRSTAT |
2994                                            DIFF_FORMAT_SUMMARY |
2995                                            DIFF_FORMAT_PATCH);
2996
2997        /*
2998         * These cases always need recursive; we do not drop caller-supplied
2999         * recursive bits for other formats here.
3000         */
3001        if (options->output_format & (DIFF_FORMAT_PATCH |
3002                                      DIFF_FORMAT_NUMSTAT |
3003                                      DIFF_FORMAT_DIFFSTAT |
3004                                      DIFF_FORMAT_SHORTSTAT |
3005                                      DIFF_FORMAT_DIRSTAT |
3006                                      DIFF_FORMAT_SUMMARY |
3007                                      DIFF_FORMAT_CHECKDIFF))
3008                DIFF_OPT_SET(options, RECURSIVE);
3009        /*
3010         * Also pickaxe would not work very well if you do not say recursive
3011         */
3012        if (options->pickaxe)
3013                DIFF_OPT_SET(options, RECURSIVE);
3014        /*
3015         * When patches are generated, submodules diffed against the work tree
3016         * must be checked for dirtiness too so it can be shown in the output
3017         */
3018        if (options->output_format & DIFF_FORMAT_PATCH)
3019                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3020
3021        if (options->detect_rename && options->rename_limit < 0)
3022                options->rename_limit = diff_rename_limit_default;
3023        if (options->setup & DIFF_SETUP_USE_CACHE) {
3024                if (!active_cache)
3025                        /* read-cache does not die even when it fails
3026                         * so it is safe for us to do this here.  Also
3027                         * it does not smudge active_cache or active_nr
3028                         * when it fails, so we do not have to worry about
3029                         * cleaning it up ourselves either.
3030                         */
3031                        read_cache();
3032        }
3033        if (options->abbrev <= 0 || 40 < options->abbrev)
3034                options->abbrev = 40; /* full */
3035
3036        /*
3037         * It does not make sense to show the first hit we happened
3038         * to have found.  It does not make sense not to return with
3039         * exit code in such a case either.
3040         */
3041        if (DIFF_OPT_TST(options, QUICK)) {
3042                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3043                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3044        }
3045
3046        return 0;
3047}
3048
3049static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3050{
3051        char c, *eq;
3052        int len;
3053
3054        if (*arg != '-')
3055                return 0;
3056        c = *++arg;
3057        if (!c)
3058                return 0;
3059        if (c == arg_short) {
3060                c = *++arg;
3061                if (!c)
3062                        return 1;
3063                if (val && isdigit(c)) {
3064                        char *end;
3065                        int n = strtoul(arg, &end, 10);
3066                        if (*end)
3067                                return 0;
3068                        *val = n;
3069                        return 1;
3070                }
3071                return 0;
3072        }
3073        if (c != '-')
3074                return 0;
3075        arg++;
3076        eq = strchr(arg, '=');
3077        if (eq)
3078                len = eq - arg;
3079        else
3080                len = strlen(arg);
3081        if (!len || strncmp(arg, arg_long, len))
3082                return 0;
3083        if (eq) {
3084                int n;
3085                char *end;
3086                if (!isdigit(*++eq))
3087                        return 0;
3088                n = strtoul(eq, &end, 10);
3089                if (*end)
3090                        return 0;
3091                *val = n;
3092        }
3093        return 1;
3094}
3095
3096static int diff_scoreopt_parse(const char *opt);
3097
3098static inline int short_opt(char opt, const char **argv,
3099                            const char **optarg)
3100{
3101        const char *arg = argv[0];
3102        if (arg[0] != '-' || arg[1] != opt)
3103                return 0;
3104        if (arg[2] != '\0') {
3105                *optarg = arg + 2;
3106                return 1;
3107        }
3108        if (!argv[1])
3109                die("Option '%c' requires a value", opt);
3110        *optarg = argv[1];
3111        return 2;
3112}
3113
3114int parse_long_opt(const char *opt, const char **argv,
3115                   const char **optarg)
3116{
3117        const char *arg = argv[0];
3118        if (arg[0] != '-' || arg[1] != '-')
3119                return 0;
3120        arg += strlen("--");
3121        if (prefixcmp(arg, opt))
3122                return 0;
3123        arg += strlen(opt);
3124        if (*arg == '=') { /* sticked form: --option=value */
3125                *optarg = arg + 1;
3126                return 1;
3127        }
3128        if (*arg != '\0')
3129                return 0;
3130        /* separate form: --option value */
3131        if (!argv[1])
3132                die("Option '--%s' requires a value", opt);
3133        *optarg = argv[1];
3134        return 2;
3135}
3136
3137static int stat_opt(struct diff_options *options, const char **av)
3138{
3139        const char *arg = av[0];
3140        char *end;
3141        int width = options->stat_width;
3142        int name_width = options->stat_name_width;
3143        int argcount = 1;
3144
3145        arg += strlen("--stat");
3146        end = (char *)arg;
3147
3148        switch (*arg) {
3149        case '-':
3150                if (!prefixcmp(arg, "-width")) {
3151                        arg += strlen("-width");
3152                        if (*arg == '=')
3153                                width = strtoul(arg + 1, &end, 10);
3154                        else if (!*arg && !av[1])
3155                                die("Option '--stat-width' requires a value");
3156                        else if (!*arg) {
3157                                width = strtoul(av[1], &end, 10);
3158                                argcount = 2;
3159                        }
3160                } else if (!prefixcmp(arg, "-name-width")) {
3161                        arg += strlen("-name-width");
3162                        if (*arg == '=')
3163                                name_width = strtoul(arg + 1, &end, 10);
3164                        else if (!*arg && !av[1])
3165                                die("Option '--stat-name-width' requires a value");
3166                        else if (!*arg) {
3167                                name_width = strtoul(av[1], &end, 10);
3168                                argcount = 2;
3169                        }
3170                }
3171                break;
3172        case '=':
3173                width = strtoul(arg+1, &end, 10);
3174                if (*end == ',')
3175                        name_width = strtoul(end+1, &end, 10);
3176        }
3177
3178        /* Important! This checks all the error cases! */
3179        if (*end)
3180                return 0;
3181        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3182        options->stat_name_width = name_width;
3183        options->stat_width = width;
3184        return argcount;
3185}
3186
3187static int parse_dirstat_opt(struct diff_options *options, const char *params)
3188{
3189        if (parse_dirstat_params(options, params))
3190                die("Failed to parse --dirstat/-X option parameter");
3191        /*
3192         * The caller knows a dirstat-related option is given from the command
3193         * line; allow it to say "return this_function();"
3194         */
3195        options->output_format |= DIFF_FORMAT_DIRSTAT;
3196        return 1;
3197}
3198
3199int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3200{
3201        const char *arg = av[0];
3202        const char *optarg;
3203        int argcount;
3204
3205        /* Output format options */
3206        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3207                options->output_format |= DIFF_FORMAT_PATCH;
3208        else if (opt_arg(arg, 'U', "unified", &options->context))
3209                options->output_format |= DIFF_FORMAT_PATCH;
3210        else if (!strcmp(arg, "--raw"))
3211                options->output_format |= DIFF_FORMAT_RAW;
3212        else if (!strcmp(arg, "--patch-with-raw"))
3213                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3214        else if (!strcmp(arg, "--numstat"))
3215                options->output_format |= DIFF_FORMAT_NUMSTAT;
3216        else if (!strcmp(arg, "--shortstat"))
3217                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3218        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3219                return parse_dirstat_opt(options, "");
3220        else if (!prefixcmp(arg, "-X"))
3221                return parse_dirstat_opt(options, arg + 2);
3222        else if (!prefixcmp(arg, "--dirstat="))
3223                return parse_dirstat_opt(options, arg + 10);
3224        else if (!strcmp(arg, "--cumulative"))
3225                return parse_dirstat_opt(options, "cumulative");
3226        else if (!strcmp(arg, "--dirstat-by-file"))
3227                return parse_dirstat_opt(options, "files");
3228        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3229                parse_dirstat_opt(options, "files");
3230                return parse_dirstat_opt(options, arg + 18);
3231        }
3232        else if (!strcmp(arg, "--check"))
3233                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3234        else if (!strcmp(arg, "--summary"))
3235                options->output_format |= DIFF_FORMAT_SUMMARY;
3236        else if (!strcmp(arg, "--patch-with-stat"))
3237                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3238        else if (!strcmp(arg, "--name-only"))
3239                options->output_format |= DIFF_FORMAT_NAME;
3240        else if (!strcmp(arg, "--name-status"))
3241                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3242        else if (!strcmp(arg, "-s"))
3243                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3244        else if (!prefixcmp(arg, "--stat"))
3245                /* --stat, --stat-width, or --stat-name-width */
3246                return stat_opt(options, av);
3247
3248        /* renames options */
3249        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3250                 !strcmp(arg, "--break-rewrites")) {
3251                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3252                        return error("invalid argument to -B: %s", arg+2);
3253        }
3254        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3255                 !strcmp(arg, "--find-renames")) {
3256                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3257                        return error("invalid argument to -M: %s", arg+2);
3258                options->detect_rename = DIFF_DETECT_RENAME;
3259        }
3260        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3261                options->irreversible_delete = 1;
3262        }
3263        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3264                 !strcmp(arg, "--find-copies")) {
3265                if (options->detect_rename == DIFF_DETECT_COPY)
3266                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3267                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3268                        return error("invalid argument to -C: %s", arg+2);
3269                options->detect_rename = DIFF_DETECT_COPY;
3270        }
3271        else if (!strcmp(arg, "--no-renames"))
3272                options->detect_rename = 0;
3273        else if (!strcmp(arg, "--relative"))
3274                DIFF_OPT_SET(options, RELATIVE_NAME);
3275        else if (!prefixcmp(arg, "--relative=")) {
3276                DIFF_OPT_SET(options, RELATIVE_NAME);
3277                options->prefix = arg + 11;
3278        }
3279
3280        /* xdiff options */
3281        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3282                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3283        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3284                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3285        else if (!strcmp(arg, "--ignore-space-at-eol"))
3286                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3287        else if (!strcmp(arg, "--patience"))
3288                DIFF_XDL_SET(options, PATIENCE_DIFF);
3289
3290        /* flags options */
3291        else if (!strcmp(arg, "--binary")) {
3292                options->output_format |= DIFF_FORMAT_PATCH;
3293                DIFF_OPT_SET(options, BINARY);
3294        }
3295        else if (!strcmp(arg, "--full-index"))
3296                DIFF_OPT_SET(options, FULL_INDEX);
3297        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3298                DIFF_OPT_SET(options, TEXT);
3299        else if (!strcmp(arg, "-R"))
3300                DIFF_OPT_SET(options, REVERSE_DIFF);
3301        else if (!strcmp(arg, "--find-copies-harder"))
3302                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3303        else if (!strcmp(arg, "--follow"))
3304                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3305        else if (!strcmp(arg, "--color"))
3306                DIFF_OPT_SET(options, COLOR_DIFF);
3307        else if (!prefixcmp(arg, "--color=")) {
3308                int value = git_config_colorbool(NULL, arg+8, -1);
3309                if (value == 0)
3310                        DIFF_OPT_CLR(options, COLOR_DIFF);
3311                else if (value > 0)
3312                        DIFF_OPT_SET(options, COLOR_DIFF);
3313                else
3314                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3315        }
3316        else if (!strcmp(arg, "--no-color"))
3317                DIFF_OPT_CLR(options, COLOR_DIFF);
3318        else if (!strcmp(arg, "--color-words")) {
3319                DIFF_OPT_SET(options, COLOR_DIFF);
3320                options->word_diff = DIFF_WORDS_COLOR;
3321        }
3322        else if (!prefixcmp(arg, "--color-words=")) {
3323                DIFF_OPT_SET(options, COLOR_DIFF);
3324                options->word_diff = DIFF_WORDS_COLOR;
3325                options->word_regex = arg + 14;
3326        }
3327        else if (!strcmp(arg, "--word-diff")) {
3328                if (options->word_diff == DIFF_WORDS_NONE)
3329                        options->word_diff = DIFF_WORDS_PLAIN;
3330        }
3331        else if (!prefixcmp(arg, "--word-diff=")) {
3332                const char *type = arg + 12;
3333                if (!strcmp(type, "plain"))
3334                        options->word_diff = DIFF_WORDS_PLAIN;
3335                else if (!strcmp(type, "color")) {
3336                        DIFF_OPT_SET(options, COLOR_DIFF);
3337                        options->word_diff = DIFF_WORDS_COLOR;
3338                }
3339                else if (!strcmp(type, "porcelain"))
3340                        options->word_diff = DIFF_WORDS_PORCELAIN;
3341                else if (!strcmp(type, "none"))
3342                        options->word_diff = DIFF_WORDS_NONE;
3343                else
3344                        die("bad --word-diff argument: %s", type);
3345        }
3346        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3347                if (options->word_diff == DIFF_WORDS_NONE)
3348                        options->word_diff = DIFF_WORDS_PLAIN;
3349                options->word_regex = optarg;
3350                return argcount;
3351        }
3352        else if (!strcmp(arg, "--exit-code"))
3353                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3354        else if (!strcmp(arg, "--quiet"))
3355                DIFF_OPT_SET(options, QUICK);
3356        else if (!strcmp(arg, "--ext-diff"))
3357                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3358        else if (!strcmp(arg, "--no-ext-diff"))
3359                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3360        else if (!strcmp(arg, "--textconv"))
3361                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3362        else if (!strcmp(arg, "--no-textconv"))
3363                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3364        else if (!strcmp(arg, "--ignore-submodules")) {
3365                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3366                handle_ignore_submodules_arg(options, "all");
3367        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3368                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3369                handle_ignore_submodules_arg(options, arg + 20);
3370        } else if (!strcmp(arg, "--submodule"))
3371                DIFF_OPT_SET(options, SUBMODULE_LOG);
3372        else if (!prefixcmp(arg, "--submodule=")) {
3373                if (!strcmp(arg + 12, "log"))
3374                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3375        }
3376
3377        /* misc options */
3378        else if (!strcmp(arg, "-z"))
3379                options->line_termination = 0;
3380        else if ((argcount = short_opt('l', av, &optarg))) {
3381                options->rename_limit = strtoul(optarg, NULL, 10);
3382                return argcount;
3383        }
3384        else if ((argcount = short_opt('S', av, &optarg))) {
3385                options->pickaxe = optarg;
3386                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3387                return argcount;
3388        } else if ((argcount = short_opt('G', av, &optarg))) {
3389                options->pickaxe = optarg;
3390                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3391                return argcount;
3392        }
3393        else if (!strcmp(arg, "--pickaxe-all"))
3394                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3395        else if (!strcmp(arg, "--pickaxe-regex"))
3396                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3397        else if ((argcount = short_opt('O', av, &optarg))) {
3398                options->orderfile = optarg;
3399                return argcount;
3400        }
3401        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3402                options->filter = optarg;
3403                return argcount;
3404        }
3405        else if (!strcmp(arg, "--abbrev"))
3406                options->abbrev = DEFAULT_ABBREV;
3407        else if (!prefixcmp(arg, "--abbrev=")) {
3408                options->abbrev = strtoul(arg + 9, NULL, 10);
3409                if (options->abbrev < MINIMUM_ABBREV)
3410                        options->abbrev = MINIMUM_ABBREV;
3411                else if (40 < options->abbrev)
3412                        options->abbrev = 40;
3413        }
3414        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3415                options->a_prefix = optarg;
3416                return argcount;
3417        }
3418        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3419                options->b_prefix = optarg;
3420                return argcount;
3421        }
3422        else if (!strcmp(arg, "--no-prefix"))
3423                options->a_prefix = options->b_prefix = "";
3424        else if (opt_arg(arg, '\0', "inter-hunk-context",
3425                         &options->interhunkcontext))
3426                ;
3427        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3428                options->file = fopen(optarg, "w");
3429                if (!options->file)
3430                        die_errno("Could not open '%s'", optarg);
3431                options->close_file = 1;
3432                return argcount;
3433        } else
3434                return 0;
3435        return 1;
3436}
3437
3438int parse_rename_score(const char **cp_p)
3439{
3440        unsigned long num, scale;
3441        int ch, dot;
3442        const char *cp = *cp_p;
3443
3444        num = 0;
3445        scale = 1;
3446        dot = 0;
3447        for (;;) {
3448                ch = *cp;
3449                if ( !dot && ch == '.' ) {
3450                        scale = 1;
3451                        dot = 1;
3452                } else if ( ch == '%' ) {
3453                        scale = dot ? scale*100 : 100;
3454                        cp++;   /* % is always at the end */
3455                        break;
3456                } else if ( ch >= '0' && ch <= '9' ) {
3457                        if ( scale < 100000 ) {
3458                                scale *= 10;
3459                                num = (num*10) + (ch-'0');
3460                        }
3461                } else {
3462                        break;
3463                }
3464                cp++;
3465        }
3466        *cp_p = cp;
3467
3468        /* user says num divided by scale and we say internally that
3469         * is MAX_SCORE * num / scale.
3470         */
3471        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3472}
3473
3474static int diff_scoreopt_parse(const char *opt)
3475{
3476        int opt1, opt2, cmd;
3477
3478        if (*opt++ != '-')
3479                return -1;
3480        cmd = *opt++;
3481        if (cmd == '-') {
3482                /* convert the long-form arguments into short-form versions */
3483                if (!prefixcmp(opt, "break-rewrites")) {
3484                        opt += strlen("break-rewrites");
3485                        if (*opt == 0 || *opt++ == '=')
3486                                cmd = 'B';
3487                } else if (!prefixcmp(opt, "find-copies")) {
3488                        opt += strlen("find-copies");
3489                        if (*opt == 0 || *opt++ == '=')
3490                                cmd = 'C';
3491                } else if (!prefixcmp(opt, "find-renames")) {
3492                        opt += strlen("find-renames");
3493                        if (*opt == 0 || *opt++ == '=')
3494                                cmd = 'M';
3495                }
3496        }
3497        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3498                return -1; /* that is not a -M, -C nor -B option */
3499
3500        opt1 = parse_rename_score(&opt);
3501        if (cmd != 'B')
3502                opt2 = 0;
3503        else {
3504                if (*opt == 0)
3505                        opt2 = 0;
3506                else if (*opt != '/')
3507                        return -1; /* we expect -B80/99 or -B80 */
3508                else {
3509                        opt++;
3510                        opt2 = parse_rename_score(&opt);
3511                }
3512        }
3513        if (*opt != 0)
3514                return -1;
3515        return opt1 | (opt2 << 16);
3516}
3517
3518struct diff_queue_struct diff_queued_diff;
3519
3520void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3521{
3522        if (queue->alloc <= queue->nr) {
3523                queue->alloc = alloc_nr(queue->alloc);
3524                queue->queue = xrealloc(queue->queue,
3525                                        sizeof(dp) * queue->alloc);
3526        }
3527        queue->queue[queue->nr++] = dp;
3528}
3529
3530struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3531                                 struct diff_filespec *one,
3532                                 struct diff_filespec *two)
3533{
3534        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3535        dp->one = one;
3536        dp->two = two;
3537        if (queue)
3538                diff_q(queue, dp);
3539        return dp;
3540}
3541
3542void diff_free_filepair(struct diff_filepair *p)
3543{
3544        free_filespec(p->one);
3545        free_filespec(p->two);
3546        free(p);
3547}
3548
3549/* This is different from find_unique_abbrev() in that
3550 * it stuffs the result with dots for alignment.
3551 */
3552const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3553{
3554        int abblen;
3555        const char *abbrev;
3556        if (len == 40)
3557                return sha1_to_hex(sha1);
3558
3559        abbrev = find_unique_abbrev(sha1, len);
3560        abblen = strlen(abbrev);
3561        if (abblen < 37) {
3562                static char hex[41];
3563                if (len < abblen && abblen <= len + 2)
3564                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3565                else
3566                        sprintf(hex, "%s...", abbrev);
3567                return hex;
3568        }
3569        return sha1_to_hex(sha1);
3570}
3571
3572static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3573{
3574        int line_termination = opt->line_termination;
3575        int inter_name_termination = line_termination ? '\t' : '\0';
3576        if (opt->output_prefix) {
3577                struct strbuf *msg = NULL;
3578                msg = opt->output_prefix(opt, opt->output_prefix_data);
3579                fprintf(opt->file, "%s", msg->buf);
3580        }
3581
3582        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3583                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3584                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3585                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3586        }
3587        if (p->score) {
3588                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3589                        inter_name_termination);
3590        } else {
3591                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3592        }
3593
3594        if (p->status == DIFF_STATUS_COPIED ||
3595            p->status == DIFF_STATUS_RENAMED) {
3596                const char *name_a, *name_b;
3597                name_a = p->one->path;
3598                name_b = p->two->path;
3599                strip_prefix(opt->prefix_length, &name_a, &name_b);
3600                write_name_quoted(name_a, opt->file, inter_name_termination);
3601                write_name_quoted(name_b, opt->file, line_termination);
3602        } else {
3603                const char *name_a, *name_b;
3604                name_a = p->one->mode ? p->one->path : p->two->path;
3605                name_b = NULL;
3606                strip_prefix(opt->prefix_length, &name_a, &name_b);
3607                write_name_quoted(name_a, opt->file, line_termination);
3608        }
3609}
3610
3611int diff_unmodified_pair(struct diff_filepair *p)
3612{
3613        /* This function is written stricter than necessary to support
3614         * the currently implemented transformers, but the idea is to
3615         * let transformers to produce diff_filepairs any way they want,
3616         * and filter and clean them up here before producing the output.
3617         */
3618        struct diff_filespec *one = p->one, *two = p->two;
3619
3620        if (DIFF_PAIR_UNMERGED(p))
3621                return 0; /* unmerged is interesting */
3622
3623        /* deletion, addition, mode or type change
3624         * and rename are all interesting.
3625         */
3626        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3627            DIFF_PAIR_MODE_CHANGED(p) ||
3628            strcmp(one->path, two->path))
3629                return 0;
3630
3631        /* both are valid and point at the same path.  that is, we are
3632         * dealing with a change.
3633         */
3634        if (one->sha1_valid && two->sha1_valid &&
3635            !hashcmp(one->sha1, two->sha1) &&
3636            !one->dirty_submodule && !two->dirty_submodule)
3637                return 1; /* no change */
3638        if (!one->sha1_valid && !two->sha1_valid)
3639                return 1; /* both look at the same file on the filesystem. */
3640        return 0;
3641}
3642
3643static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3644{
3645        if (diff_unmodified_pair(p))
3646                return;
3647
3648        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3649            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3650                return; /* no tree diffs in patch format */
3651
3652        run_diff(p, o);
3653}
3654
3655static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3656                            struct diffstat_t *diffstat)
3657{
3658        if (diff_unmodified_pair(p))
3659                return;
3660
3661        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3662            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3663                return; /* no useful stat for tree diffs */
3664
3665        run_diffstat(p, o, diffstat);
3666}
3667
3668static void diff_flush_checkdiff(struct diff_filepair *p,
3669                struct diff_options *o)
3670{
3671        if (diff_unmodified_pair(p))
3672                return;
3673
3674        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3675            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3676                return; /* nothing to check in tree diffs */
3677
3678        run_checkdiff(p, o);
3679}
3680
3681int diff_queue_is_empty(void)
3682{
3683        struct diff_queue_struct *q = &diff_queued_diff;
3684        int i;
3685        for (i = 0; i < q->nr; i++)
3686                if (!diff_unmodified_pair(q->queue[i]))
3687                        return 0;
3688        return 1;
3689}
3690
3691#if DIFF_DEBUG
3692void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3693{
3694        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3695                x, one ? one : "",
3696                s->path,
3697                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3698                s->mode,
3699                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3700        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3701                x, one ? one : "",
3702                s->size, s->xfrm_flags);
3703}
3704
3705void diff_debug_filepair(const struct diff_filepair *p, int i)
3706{
3707        diff_debug_filespec(p->one, i, "one");
3708        diff_debug_filespec(p->two, i, "two");
3709        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3710                p->score, p->status ? p->status : '?',
3711                p->one->rename_used, p->broken_pair);
3712}
3713
3714void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3715{
3716        int i;
3717        if (msg)
3718                fprintf(stderr, "%s\n", msg);
3719        fprintf(stderr, "q->nr = %d\n", q->nr);
3720        for (i = 0; i < q->nr; i++) {
3721                struct diff_filepair *p = q->queue[i];
3722                diff_debug_filepair(p, i);
3723        }
3724}
3725#endif
3726
3727static void diff_resolve_rename_copy(void)
3728{
3729        int i;
3730        struct diff_filepair *p;
3731        struct diff_queue_struct *q = &diff_queued_diff;
3732
3733        diff_debug_queue("resolve-rename-copy", q);
3734
3735        for (i = 0; i < q->nr; i++) {
3736                p = q->queue[i];
3737                p->status = 0; /* undecided */
3738                if (DIFF_PAIR_UNMERGED(p))
3739                        p->status = DIFF_STATUS_UNMERGED;
3740                else if (!DIFF_FILE_VALID(p->one))
3741                        p->status = DIFF_STATUS_ADDED;
3742                else if (!DIFF_FILE_VALID(p->two))
3743                        p->status = DIFF_STATUS_DELETED;
3744                else if (DIFF_PAIR_TYPE_CHANGED(p))
3745                        p->status = DIFF_STATUS_TYPE_CHANGED;
3746
3747                /* from this point on, we are dealing with a pair
3748                 * whose both sides are valid and of the same type, i.e.
3749                 * either in-place edit or rename/copy edit.
3750                 */
3751                else if (DIFF_PAIR_RENAME(p)) {
3752                        /*
3753                         * A rename might have re-connected a broken
3754                         * pair up, causing the pathnames to be the
3755                         * same again. If so, that's not a rename at
3756                         * all, just a modification..
3757                         *
3758                         * Otherwise, see if this source was used for
3759                         * multiple renames, in which case we decrement
3760                         * the count, and call it a copy.
3761                         */
3762                        if (!strcmp(p->one->path, p->two->path))
3763                                p->status = DIFF_STATUS_MODIFIED;
3764                        else if (--p->one->rename_used > 0)
3765                                p->status = DIFF_STATUS_COPIED;
3766                        else
3767                                p->status = DIFF_STATUS_RENAMED;
3768                }
3769                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3770                         p->one->mode != p->two->mode ||
3771                         p->one->dirty_submodule ||
3772                         p->two->dirty_submodule ||
3773                         is_null_sha1(p->one->sha1))
3774                        p->status = DIFF_STATUS_MODIFIED;
3775                else {
3776                        /* This is a "no-change" entry and should not
3777                         * happen anymore, but prepare for broken callers.
3778                         */
3779                        error("feeding unmodified %s to diffcore",
3780                              p->one->path);
3781                        p->status = DIFF_STATUS_UNKNOWN;
3782                }
3783        }
3784        diff_debug_queue("resolve-rename-copy done", q);
3785}
3786
3787static int check_pair_status(struct diff_filepair *p)
3788{
3789        switch (p->status) {
3790        case DIFF_STATUS_UNKNOWN:
3791                return 0;
3792        case 0:
3793                die("internal error in diff-resolve-rename-copy");
3794        default:
3795                return 1;
3796        }
3797}
3798
3799static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3800{
3801        int fmt = opt->output_format;
3802
3803        if (fmt & DIFF_FORMAT_CHECKDIFF)
3804                diff_flush_checkdiff(p, opt);
3805        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3806                diff_flush_raw(p, opt);
3807        else if (fmt & DIFF_FORMAT_NAME) {
3808                const char *name_a, *name_b;
3809                name_a = p->two->path;
3810                name_b = NULL;
3811                strip_prefix(opt->prefix_length, &name_a, &name_b);
3812                write_name_quoted(name_a, opt->file, opt->line_termination);
3813        }
3814}
3815
3816static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3817{
3818        if (fs->mode)
3819                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3820        else
3821                fprintf(file, " %s ", newdelete);
3822        write_name_quoted(fs->path, file, '\n');
3823}
3824
3825
3826static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3827                const char *line_prefix)
3828{
3829        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3830                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3831                        p->two->mode, show_name ? ' ' : '\n');
3832                if (show_name) {
3833                        write_name_quoted(p->two->path, file, '\n');
3834                }
3835        }
3836}
3837
3838static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3839                        const char *line_prefix)
3840{
3841        char *names = pprint_rename(p->one->path, p->two->path);
3842
3843        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3844        free(names);
3845        show_mode_change(file, p, 0, line_prefix);
3846}
3847
3848static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3849{
3850        FILE *file = opt->file;
3851        char *line_prefix = "";
3852
3853        if (opt->output_prefix) {
3854                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3855                line_prefix = buf->buf;
3856        }
3857
3858        switch(p->status) {
3859        case DIFF_STATUS_DELETED:
3860                fputs(line_prefix, file);
3861                show_file_mode_name(file, "delete", p->one);
3862                break;
3863        case DIFF_STATUS_ADDED:
3864                fputs(line_prefix, file);
3865                show_file_mode_name(file, "create", p->two);
3866                break;
3867        case DIFF_STATUS_COPIED:
3868                fputs(line_prefix, file);
3869                show_rename_copy(file, "copy", p, line_prefix);
3870                break;
3871        case DIFF_STATUS_RENAMED:
3872                fputs(line_prefix, file);
3873                show_rename_copy(file, "rename", p, line_prefix);
3874                break;
3875        default:
3876                if (p->score) {
3877                        fprintf(file, "%s rewrite ", line_prefix);
3878                        write_name_quoted(p->two->path, file, ' ');
3879                        fprintf(file, "(%d%%)\n", similarity_index(p));
3880                }
3881                show_mode_change(file, p, !p->score, line_prefix);
3882                break;
3883        }
3884}
3885
3886struct patch_id_t {
3887        git_SHA_CTX *ctx;
3888        int patchlen;
3889};
3890
3891static int remove_space(char *line, int len)
3892{
3893        int i;
3894        char *dst = line;
3895        unsigned char c;
3896
3897        for (i = 0; i < len; i++)
3898                if (!isspace((c = line[i])))
3899                        *dst++ = c;
3900
3901        return dst - line;
3902}
3903
3904static void patch_id_consume(void *priv, char *line, unsigned long len)
3905{
3906        struct patch_id_t *data = priv;
3907        int new_len;
3908
3909        /* Ignore line numbers when computing the SHA1 of the patch */
3910        if (!prefixcmp(line, "@@ -"))
3911                return;
3912
3913        new_len = remove_space(line, len);
3914
3915        git_SHA1_Update(data->ctx, line, new_len);
3916        data->patchlen += new_len;
3917}
3918
3919/* returns 0 upon success, and writes result into sha1 */
3920static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3921{
3922        struct diff_queue_struct *q = &diff_queued_diff;
3923        int i;
3924        git_SHA_CTX ctx;
3925        struct patch_id_t data;
3926        char buffer[PATH_MAX * 4 + 20];
3927
3928        git_SHA1_Init(&ctx);
3929        memset(&data, 0, sizeof(struct patch_id_t));
3930        data.ctx = &ctx;
3931
3932        for (i = 0; i < q->nr; i++) {
3933                xpparam_t xpp;
3934                xdemitconf_t xecfg;
3935                mmfile_t mf1, mf2;
3936                struct diff_filepair *p = q->queue[i];
3937                int len1, len2;
3938
3939                memset(&xpp, 0, sizeof(xpp));
3940                memset(&xecfg, 0, sizeof(xecfg));
3941                if (p->status == 0)
3942                        return error("internal diff status error");
3943                if (p->status == DIFF_STATUS_UNKNOWN)
3944                        continue;
3945                if (diff_unmodified_pair(p))
3946                        continue;
3947                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3948                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3949                        continue;
3950                if (DIFF_PAIR_UNMERGED(p))
3951                        continue;
3952
3953                diff_fill_sha1_info(p->one);
3954                diff_fill_sha1_info(p->two);
3955                if (fill_mmfile(&mf1, p->one) < 0 ||
3956                                fill_mmfile(&mf2, p->two) < 0)
3957                        return error("unable to read files to diff");
3958
3959                len1 = remove_space(p->one->path, strlen(p->one->path));
3960                len2 = remove_space(p->two->path, strlen(p->two->path));
3961                if (p->one->mode == 0)
3962                        len1 = snprintf(buffer, sizeof(buffer),
3963                                        "diff--gita/%.*sb/%.*s"
3964                                        "newfilemode%06o"
3965                                        "---/dev/null"
3966                                        "+++b/%.*s",
3967                                        len1, p->one->path,
3968                                        len2, p->two->path,
3969                                        p->two->mode,
3970                                        len2, p->two->path);
3971                else if (p->two->mode == 0)
3972                        len1 = snprintf(buffer, sizeof(buffer),
3973                                        "diff--gita/%.*sb/%.*s"
3974                                        "deletedfilemode%06o"
3975                                        "---a/%.*s"
3976                                        "+++/dev/null",
3977                                        len1, p->one->path,
3978                                        len2, p->two->path,
3979                                        p->one->mode,
3980                                        len1, p->one->path);
3981                else
3982                        len1 = snprintf(buffer, sizeof(buffer),
3983                                        "diff--gita/%.*sb/%.*s"
3984                                        "---a/%.*s"
3985                                        "+++b/%.*s",
3986                                        len1, p->one->path,
3987                                        len2, p->two->path,
3988                                        len1, p->one->path,
3989                                        len2, p->two->path);
3990                git_SHA1_Update(&ctx, buffer, len1);
3991
3992                if (diff_filespec_is_binary(p->one) ||
3993                    diff_filespec_is_binary(p->two)) {
3994                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3995                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3996                        continue;
3997                }
3998
3999                xpp.flags = 0;
4000                xecfg.ctxlen = 3;
4001                xecfg.flags = 0;
4002                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4003                              &xpp, &xecfg);
4004        }
4005
4006        git_SHA1_Final(sha1, &ctx);
4007        return 0;
4008}
4009
4010int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4011{
4012        struct diff_queue_struct *q = &diff_queued_diff;
4013        int i;
4014        int result = diff_get_patch_id(options, sha1);
4015
4016        for (i = 0; i < q->nr; i++)
4017                diff_free_filepair(q->queue[i]);
4018
4019        free(q->queue);
4020        DIFF_QUEUE_CLEAR(q);
4021
4022        return result;
4023}
4024
4025static int is_summary_empty(const struct diff_queue_struct *q)
4026{
4027        int i;
4028
4029        for (i = 0; i < q->nr; i++) {
4030                const struct diff_filepair *p = q->queue[i];
4031
4032                switch (p->status) {
4033                case DIFF_STATUS_DELETED:
4034                case DIFF_STATUS_ADDED:
4035                case DIFF_STATUS_COPIED:
4036                case DIFF_STATUS_RENAMED:
4037                        return 0;
4038                default:
4039                        if (p->score)
4040                                return 0;
4041                        if (p->one->mode && p->two->mode &&
4042                            p->one->mode != p->two->mode)
4043                                return 0;
4044                        break;
4045                }
4046        }
4047        return 1;
4048}
4049
4050static const char rename_limit_warning[] =
4051"inexact rename detection was skipped due to too many files.";
4052
4053static const char degrade_cc_to_c_warning[] =
4054"only found copies from modified paths due to too many files.";
4055
4056static const char rename_limit_advice[] =
4057"you may want to set your %s variable to at least "
4058"%d and retry the command.";
4059
4060void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4061{
4062        if (degraded_cc)
4063                warning(degrade_cc_to_c_warning);
4064        else if (needed)
4065                warning(rename_limit_warning);
4066        else
4067                return;
4068        if (0 < needed && needed < 32767)
4069                warning(rename_limit_advice, varname, needed);
4070}
4071
4072void diff_flush(struct diff_options *options)
4073{
4074        struct diff_queue_struct *q = &diff_queued_diff;
4075        int i, output_format = options->output_format;
4076        int separator = 0;
4077
4078        /*
4079         * Order: raw, stat, summary, patch
4080         * or:    name/name-status/checkdiff (other bits clear)
4081         */
4082        if (!q->nr)
4083                goto free_queue;
4084
4085        if (output_format & (DIFF_FORMAT_RAW |
4086                             DIFF_FORMAT_NAME |
4087                             DIFF_FORMAT_NAME_STATUS |
4088                             DIFF_FORMAT_CHECKDIFF)) {
4089                for (i = 0; i < q->nr; i++) {
4090                        struct diff_filepair *p = q->queue[i];
4091                        if (check_pair_status(p))
4092                                flush_one_pair(p, options);
4093                }
4094                separator++;
4095        }
4096
4097        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4098                struct diffstat_t diffstat;
4099
4100                memset(&diffstat, 0, sizeof(struct diffstat_t));
4101                for (i = 0; i < q->nr; i++) {
4102                        struct diff_filepair *p = q->queue[i];
4103                        if (check_pair_status(p))
4104                                diff_flush_stat(p, options, &diffstat);
4105                }
4106                if (output_format & DIFF_FORMAT_NUMSTAT)
4107                        show_numstat(&diffstat, options);
4108                if (output_format & DIFF_FORMAT_DIFFSTAT)
4109                        show_stats(&diffstat, options);
4110                if (output_format & DIFF_FORMAT_SHORTSTAT)
4111                        show_shortstats(&diffstat, options);
4112                free_diffstat_info(&diffstat);
4113                separator++;
4114        }
4115        if (output_format & DIFF_FORMAT_DIRSTAT)
4116                show_dirstat(options);
4117
4118        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4119                for (i = 0; i < q->nr; i++) {
4120                        diff_summary(options, q->queue[i]);
4121                }
4122                separator++;
4123        }
4124
4125        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4126            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4127            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4128                /*
4129                 * run diff_flush_patch for the exit status. setting
4130                 * options->file to /dev/null should be safe, becaue we
4131                 * aren't supposed to produce any output anyway.
4132                 */
4133                if (options->close_file)
4134                        fclose(options->file);
4135                options->file = fopen("/dev/null", "w");
4136                if (!options->file)
4137                        die_errno("Could not open /dev/null");
4138                options->close_file = 1;
4139                for (i = 0; i < q->nr; i++) {
4140                        struct diff_filepair *p = q->queue[i];
4141                        if (check_pair_status(p))
4142                                diff_flush_patch(p, options);
4143                        if (options->found_changes)
4144                                break;
4145                }
4146        }
4147
4148        if (output_format & DIFF_FORMAT_PATCH) {
4149                if (separator) {
4150                        putc(options->line_termination, options->file);
4151                        if (options->stat_sep) {
4152                                /* attach patch instead of inline */
4153                                fputs(options->stat_sep, options->file);
4154                        }
4155                }
4156
4157                for (i = 0; i < q->nr; i++) {
4158                        struct diff_filepair *p = q->queue[i];
4159                        if (check_pair_status(p))
4160                                diff_flush_patch(p, options);
4161                }
4162        }
4163
4164        if (output_format & DIFF_FORMAT_CALLBACK)
4165                options->format_callback(q, options, options->format_callback_data);
4166
4167        for (i = 0; i < q->nr; i++)
4168                diff_free_filepair(q->queue[i]);
4169free_queue:
4170        free(q->queue);
4171        DIFF_QUEUE_CLEAR(q);
4172        if (options->close_file)
4173                fclose(options->file);
4174
4175        /*
4176         * Report the content-level differences with HAS_CHANGES;
4177         * diff_addremove/diff_change does not set the bit when
4178         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4179         */
4180        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4181                if (options->found_changes)
4182                        DIFF_OPT_SET(options, HAS_CHANGES);
4183                else
4184                        DIFF_OPT_CLR(options, HAS_CHANGES);
4185        }
4186}
4187
4188static void diffcore_apply_filter(const char *filter)
4189{
4190        int i;
4191        struct diff_queue_struct *q = &diff_queued_diff;
4192        struct diff_queue_struct outq;
4193        DIFF_QUEUE_CLEAR(&outq);
4194
4195        if (!filter)
4196                return;
4197
4198        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4199                int found;
4200                for (i = found = 0; !found && i < q->nr; i++) {
4201                        struct diff_filepair *p = q->queue[i];
4202                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4203                             ((p->score &&
4204                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4205                              (!p->score &&
4206                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4207                            ((p->status != DIFF_STATUS_MODIFIED) &&
4208                             strchr(filter, p->status)))
4209                                found++;
4210                }
4211                if (found)
4212                        return;
4213
4214                /* otherwise we will clear the whole queue
4215                 * by copying the empty outq at the end of this
4216                 * function, but first clear the current entries
4217                 * in the queue.
4218                 */
4219                for (i = 0; i < q->nr; i++)
4220                        diff_free_filepair(q->queue[i]);
4221        }
4222        else {
4223                /* Only the matching ones */
4224                for (i = 0; i < q->nr; i++) {
4225                        struct diff_filepair *p = q->queue[i];
4226
4227                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4228                             ((p->score &&
4229                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4230                              (!p->score &&
4231                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4232                            ((p->status != DIFF_STATUS_MODIFIED) &&
4233                             strchr(filter, p->status)))
4234                                diff_q(&outq, p);
4235                        else
4236                                diff_free_filepair(p);
4237                }
4238        }
4239        free(q->queue);
4240        *q = outq;
4241}
4242
4243/* Check whether two filespecs with the same mode and size are identical */
4244static int diff_filespec_is_identical(struct diff_filespec *one,
4245                                      struct diff_filespec *two)
4246{
4247        if (S_ISGITLINK(one->mode))
4248                return 0;
4249        if (diff_populate_filespec(one, 0))
4250                return 0;
4251        if (diff_populate_filespec(two, 0))
4252                return 0;
4253        return !memcmp(one->data, two->data, one->size);
4254}
4255
4256static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4257{
4258        int i;
4259        struct diff_queue_struct *q = &diff_queued_diff;
4260        struct diff_queue_struct outq;
4261        DIFF_QUEUE_CLEAR(&outq);
4262
4263        for (i = 0; i < q->nr; i++) {
4264                struct diff_filepair *p = q->queue[i];
4265
4266                /*
4267                 * 1. Entries that come from stat info dirtiness
4268                 *    always have both sides (iow, not create/delete),
4269                 *    one side of the object name is unknown, with
4270                 *    the same mode and size.  Keep the ones that
4271                 *    do not match these criteria.  They have real
4272                 *    differences.
4273                 *
4274                 * 2. At this point, the file is known to be modified,
4275                 *    with the same mode and size, and the object
4276                 *    name of one side is unknown.  Need to inspect
4277                 *    the identical contents.
4278                 */
4279                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4280                    !DIFF_FILE_VALID(p->two) ||
4281                    (p->one->sha1_valid && p->two->sha1_valid) ||
4282                    (p->one->mode != p->two->mode) ||
4283                    diff_populate_filespec(p->one, 1) ||
4284                    diff_populate_filespec(p->two, 1) ||
4285                    (p->one->size != p->two->size) ||
4286                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4287                        diff_q(&outq, p);
4288                else {
4289                        /*
4290                         * The caller can subtract 1 from skip_stat_unmatch
4291                         * to determine how many paths were dirty only
4292                         * due to stat info mismatch.
4293                         */
4294                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4295                                diffopt->skip_stat_unmatch++;
4296                        diff_free_filepair(p);
4297                }
4298        }
4299        free(q->queue);
4300        *q = outq;
4301}
4302
4303static int diffnamecmp(const void *a_, const void *b_)
4304{
4305        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4306        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4307        const char *name_a, *name_b;
4308
4309        name_a = a->one ? a->one->path : a->two->path;
4310        name_b = b->one ? b->one->path : b->two->path;
4311        return strcmp(name_a, name_b);
4312}
4313
4314void diffcore_fix_diff_index(struct diff_options *options)
4315{
4316        struct diff_queue_struct *q = &diff_queued_diff;
4317        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4318}
4319
4320void diffcore_std(struct diff_options *options)
4321{
4322        if (options->skip_stat_unmatch)
4323                diffcore_skip_stat_unmatch(options);
4324        if (!options->found_follow) {
4325                /* See try_to_follow_renames() in tree-diff.c */
4326                if (options->break_opt != -1)
4327                        diffcore_break(options->break_opt);
4328                if (options->detect_rename)
4329                        diffcore_rename(options);
4330                if (options->break_opt != -1)
4331                        diffcore_merge_broken();
4332        }
4333        if (options->pickaxe)
4334                diffcore_pickaxe(options);
4335        if (options->orderfile)
4336                diffcore_order(options->orderfile);
4337        if (!options->found_follow)
4338                /* See try_to_follow_renames() in tree-diff.c */
4339                diff_resolve_rename_copy();
4340        diffcore_apply_filter(options->filter);
4341
4342        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4343                DIFF_OPT_SET(options, HAS_CHANGES);
4344        else
4345                DIFF_OPT_CLR(options, HAS_CHANGES);
4346
4347        options->found_follow = 0;
4348}
4349
4350int diff_result_code(struct diff_options *opt, int status)
4351{
4352        int result = 0;
4353
4354        diff_warn_rename_limit("diff.renamelimit",
4355                               opt->needed_rename_limit,
4356                               opt->degraded_cc_to_c);
4357        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4358            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4359                return status;
4360        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4361            DIFF_OPT_TST(opt, HAS_CHANGES))
4362                result |= 01;
4363        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4364            DIFF_OPT_TST(opt, CHECK_FAILED))
4365                result |= 02;
4366        return result;
4367}
4368
4369/*
4370 * Shall changes to this submodule be ignored?
4371 *
4372 * Submodule changes can be configured to be ignored separately for each path,
4373 * but that configuration can be overridden from the command line.
4374 */
4375static int is_submodule_ignored(const char *path, struct diff_options *options)
4376{
4377        int ignored = 0;
4378        unsigned orig_flags = options->flags;
4379        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4380                set_diffopt_flags_from_submodule_config(options, path);
4381        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4382                ignored = 1;
4383        options->flags = orig_flags;
4384        return ignored;
4385}
4386
4387void diff_addremove(struct diff_options *options,
4388                    int addremove, unsigned mode,
4389                    const unsigned char *sha1,
4390                    const char *concatpath, unsigned dirty_submodule)
4391{
4392        struct diff_filespec *one, *two;
4393
4394        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4395                return;
4396
4397        /* This may look odd, but it is a preparation for
4398         * feeding "there are unchanged files which should
4399         * not produce diffs, but when you are doing copy
4400         * detection you would need them, so here they are"
4401         * entries to the diff-core.  They will be prefixed
4402         * with something like '=' or '*' (I haven't decided
4403         * which but should not make any difference).
4404         * Feeding the same new and old to diff_change()
4405         * also has the same effect.
4406         * Before the final output happens, they are pruned after
4407         * merged into rename/copy pairs as appropriate.
4408         */
4409        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4410                addremove = (addremove == '+' ? '-' :
4411                             addremove == '-' ? '+' : addremove);
4412
4413        if (options->prefix &&
4414            strncmp(concatpath, options->prefix, options->prefix_length))
4415                return;
4416
4417        one = alloc_filespec(concatpath);
4418        two = alloc_filespec(concatpath);
4419
4420        if (addremove != '+')
4421                fill_filespec(one, sha1, mode);
4422        if (addremove != '-') {
4423                fill_filespec(two, sha1, mode);
4424                two->dirty_submodule = dirty_submodule;
4425        }
4426
4427        diff_queue(&diff_queued_diff, one, two);
4428        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4429                DIFF_OPT_SET(options, HAS_CHANGES);
4430}
4431
4432void diff_change(struct diff_options *options,
4433                 unsigned old_mode, unsigned new_mode,
4434                 const unsigned char *old_sha1,
4435                 const unsigned char *new_sha1,
4436                 const char *concatpath,
4437                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4438{
4439        struct diff_filespec *one, *two;
4440
4441        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4442            is_submodule_ignored(concatpath, options))
4443                return;
4444
4445        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4446                unsigned tmp;
4447                const unsigned char *tmp_c;
4448                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4449                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4450                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4451                        new_dirty_submodule = tmp;
4452        }
4453
4454        if (options->prefix &&
4455            strncmp(concatpath, options->prefix, options->prefix_length))
4456                return;
4457
4458        one = alloc_filespec(concatpath);
4459        two = alloc_filespec(concatpath);
4460        fill_filespec(one, old_sha1, old_mode);
4461        fill_filespec(two, new_sha1, new_mode);
4462        one->dirty_submodule = old_dirty_submodule;
4463        two->dirty_submodule = new_dirty_submodule;
4464
4465        diff_queue(&diff_queued_diff, one, two);
4466        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4467                DIFF_OPT_SET(options, HAS_CHANGES);
4468}
4469
4470void diff_unmerge(struct diff_options *options,
4471                  const char *path,
4472                  unsigned mode, const unsigned char *sha1)
4473{
4474        struct diff_filespec *one, *two;
4475
4476        if (options->prefix &&
4477            strncmp(path, options->prefix, options->prefix_length))
4478                return;
4479
4480        one = alloc_filespec(path);
4481        two = alloc_filespec(path);
4482        fill_filespec(one, sha1, mode);
4483        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4484}
4485
4486static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4487                size_t *outsize)
4488{
4489        struct diff_tempfile *temp;
4490        const char *argv[3];
4491        const char **arg = argv;
4492        struct child_process child;
4493        struct strbuf buf = STRBUF_INIT;
4494        int err = 0;
4495
4496        temp = prepare_temp_file(spec->path, spec);
4497        *arg++ = pgm;
4498        *arg++ = temp->name;
4499        *arg = NULL;
4500
4501        memset(&child, 0, sizeof(child));
4502        child.use_shell = 1;
4503        child.argv = argv;
4504        child.out = -1;
4505        if (start_command(&child)) {
4506                remove_tempfile();
4507                return NULL;
4508        }
4509
4510        if (strbuf_read(&buf, child.out, 0) < 0)
4511                err = error("error reading from textconv command '%s'", pgm);
4512        close(child.out);
4513
4514        if (finish_command(&child) || err) {
4515                strbuf_release(&buf);
4516                remove_tempfile();
4517                return NULL;
4518        }
4519        remove_tempfile();
4520
4521        return strbuf_detach(&buf, outsize);
4522}
4523
4524size_t fill_textconv(struct userdiff_driver *driver,
4525                     struct diff_filespec *df,
4526                     char **outbuf)
4527{
4528        size_t size;
4529
4530        if (!driver || !driver->textconv) {
4531                if (!DIFF_FILE_VALID(df)) {
4532                        *outbuf = "";
4533                        return 0;
4534                }
4535                if (diff_populate_filespec(df, 0))
4536                        die("unable to read files to diff");
4537                *outbuf = df->data;
4538                return df->size;
4539        }
4540
4541        if (driver->textconv_cache && df->sha1_valid) {
4542                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4543                                          &size);
4544                if (*outbuf)
4545                        return size;
4546        }
4547
4548        *outbuf = run_textconv(driver->textconv, df, &size);
4549        if (!*outbuf)
4550                die("unable to read files to diff");
4551
4552        if (driver->textconv_cache && df->sha1_valid) {
4553                /* ignore errors, as we might be in a readonly repository */
4554                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4555                                size);
4556                /*
4557                 * we could save up changes and flush them all at the end,
4558                 * but we would need an extra call after all diffing is done.
4559                 * Since generating a cache entry is the slow path anyway,
4560                 * this extra overhead probably isn't a big deal.
4561                 */
4562                notes_cache_write(driver->textconv_cache);
4563        }
4564
4565        return size;
4566}