diff.con commit Merge branch 'mg/tracked-local-branches' (ccc852c)
   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
  17#ifdef NO_FAST_WORKING_DIRECTORY
  18#define FAST_WORKING_DIRECTORY 0
  19#else
  20#define FAST_WORKING_DIRECTORY 1
  21#endif
  22
  23static int diff_detect_rename_default;
  24static int diff_rename_limit_default = 200;
  25static int diff_suppress_blank_empty;
  26int diff_use_color_default = -1;
  27static const char *diff_word_regex_cfg;
  28static const char *external_diff_cmd_cfg;
  29int diff_auto_refresh_index = 1;
  30static int diff_mnemonic_prefix;
  31
  32static char diff_colors[][COLOR_MAXLEN] = {
  33        GIT_COLOR_RESET,
  34        GIT_COLOR_NORMAL,       /* PLAIN */
  35        GIT_COLOR_BOLD,         /* METAINFO */
  36        GIT_COLOR_CYAN,         /* FRAGINFO */
  37        GIT_COLOR_RED,          /* OLD */
  38        GIT_COLOR_GREEN,        /* NEW */
  39        GIT_COLOR_YELLOW,       /* COMMIT */
  40        GIT_COLOR_BG_RED,       /* WHITESPACE */
  41};
  42
  43static void diff_filespec_load_driver(struct diff_filespec *one);
  44static char *run_textconv(const char *, struct diff_filespec *, size_t *);
  45
  46static int parse_diff_color_slot(const char *var, int ofs)
  47{
  48        if (!strcasecmp(var+ofs, "plain"))
  49                return DIFF_PLAIN;
  50        if (!strcasecmp(var+ofs, "meta"))
  51                return DIFF_METAINFO;
  52        if (!strcasecmp(var+ofs, "frag"))
  53                return DIFF_FRAGINFO;
  54        if (!strcasecmp(var+ofs, "old"))
  55                return DIFF_FILE_OLD;
  56        if (!strcasecmp(var+ofs, "new"))
  57                return DIFF_FILE_NEW;
  58        if (!strcasecmp(var+ofs, "commit"))
  59                return DIFF_COMMIT;
  60        if (!strcasecmp(var+ofs, "whitespace"))
  61                return DIFF_WHITESPACE;
  62        die("bad config variable '%s'", var);
  63}
  64
  65/*
  66 * These are to give UI layer defaults.
  67 * The core-level commands such as git-diff-files should
  68 * never be affected by the setting of diff.renames
  69 * the user happens to have in the configuration file.
  70 */
  71int git_diff_ui_config(const char *var, const char *value, void *cb)
  72{
  73        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  74                diff_use_color_default = git_config_colorbool(var, value, -1);
  75                return 0;
  76        }
  77        if (!strcmp(var, "diff.renames")) {
  78                if (!value)
  79                        diff_detect_rename_default = DIFF_DETECT_RENAME;
  80                else if (!strcasecmp(value, "copies") ||
  81                         !strcasecmp(value, "copy"))
  82                        diff_detect_rename_default = DIFF_DETECT_COPY;
  83                else if (git_config_bool(var,value))
  84                        diff_detect_rename_default = DIFF_DETECT_RENAME;
  85                return 0;
  86        }
  87        if (!strcmp(var, "diff.autorefreshindex")) {
  88                diff_auto_refresh_index = git_config_bool(var, value);
  89                return 0;
  90        }
  91        if (!strcmp(var, "diff.mnemonicprefix")) {
  92                diff_mnemonic_prefix = git_config_bool(var, value);
  93                return 0;
  94        }
  95        if (!strcmp(var, "diff.external"))
  96                return git_config_string(&external_diff_cmd_cfg, var, value);
  97        if (!strcmp(var, "diff.wordregex"))
  98                return git_config_string(&diff_word_regex_cfg, var, value);
  99
 100        return git_diff_basic_config(var, value, cb);
 101}
 102
 103int git_diff_basic_config(const char *var, const char *value, void *cb)
 104{
 105        if (!strcmp(var, "diff.renamelimit")) {
 106                diff_rename_limit_default = git_config_int(var, value);
 107                return 0;
 108        }
 109
 110        switch (userdiff_config(var, value)) {
 111                case 0: break;
 112                case -1: return -1;
 113                default: return 0;
 114        }
 115
 116        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 117                int slot = parse_diff_color_slot(var, 11);
 118                if (!value)
 119                        return config_error_nonbool(var);
 120                color_parse(value, var, diff_colors[slot]);
 121                return 0;
 122        }
 123
 124        /* like GNU diff's --suppress-blank-empty option  */
 125        if (!strcmp(var, "diff.suppressblankempty") ||
 126                        /* for backwards compatibility */
 127                        !strcmp(var, "diff.suppress-blank-empty")) {
 128                diff_suppress_blank_empty = git_config_bool(var, value);
 129                return 0;
 130        }
 131
 132        return git_color_default_config(var, value, cb);
 133}
 134
 135static char *quote_two(const char *one, const char *two)
 136{
 137        int need_one = quote_c_style(one, NULL, NULL, 1);
 138        int need_two = quote_c_style(two, NULL, NULL, 1);
 139        struct strbuf res = STRBUF_INIT;
 140
 141        if (need_one + need_two) {
 142                strbuf_addch(&res, '"');
 143                quote_c_style(one, &res, NULL, 1);
 144                quote_c_style(two, &res, NULL, 1);
 145                strbuf_addch(&res, '"');
 146        } else {
 147                strbuf_addstr(&res, one);
 148                strbuf_addstr(&res, two);
 149        }
 150        return strbuf_detach(&res, NULL);
 151}
 152
 153static const char *external_diff(void)
 154{
 155        static const char *external_diff_cmd = NULL;
 156        static int done_preparing = 0;
 157
 158        if (done_preparing)
 159                return external_diff_cmd;
 160        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 161        if (!external_diff_cmd)
 162                external_diff_cmd = external_diff_cmd_cfg;
 163        done_preparing = 1;
 164        return external_diff_cmd;
 165}
 166
 167static struct diff_tempfile {
 168        const char *name; /* filename external diff should read from */
 169        char hex[41];
 170        char mode[10];
 171        char tmp_path[PATH_MAX];
 172} diff_temp[2];
 173
 174static struct diff_tempfile *claim_diff_tempfile(void) {
 175        int i;
 176        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 177                if (!diff_temp[i].name)
 178                        return diff_temp + i;
 179        die("BUG: diff is failing to clean up its tempfiles");
 180}
 181
 182static int remove_tempfile_installed;
 183
 184static void remove_tempfile(void)
 185{
 186        int i;
 187        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 188                if (diff_temp[i].name == diff_temp[i].tmp_path)
 189                        unlink(diff_temp[i].name);
 190                diff_temp[i].name = NULL;
 191        }
 192}
 193
 194static void remove_tempfile_on_signal(int signo)
 195{
 196        remove_tempfile();
 197        sigchain_pop(signo);
 198        raise(signo);
 199}
 200
 201static int count_lines(const char *data, int size)
 202{
 203        int count, ch, completely_empty = 1, nl_just_seen = 0;
 204        count = 0;
 205        while (0 < size--) {
 206                ch = *data++;
 207                if (ch == '\n') {
 208                        count++;
 209                        nl_just_seen = 1;
 210                        completely_empty = 0;
 211                }
 212                else {
 213                        nl_just_seen = 0;
 214                        completely_empty = 0;
 215                }
 216        }
 217        if (completely_empty)
 218                return 0;
 219        if (!nl_just_seen)
 220                count++; /* no trailing newline */
 221        return count;
 222}
 223
 224static void print_line_count(FILE *file, int count)
 225{
 226        switch (count) {
 227        case 0:
 228                fprintf(file, "0,0");
 229                break;
 230        case 1:
 231                fprintf(file, "1");
 232                break;
 233        default:
 234                fprintf(file, "1,%d", count);
 235                break;
 236        }
 237}
 238
 239static void copy_file_with_prefix(FILE *file,
 240                                  int prefix, const char *data, int size,
 241                                  const char *set, const char *reset)
 242{
 243        int ch, nl_just_seen = 1;
 244        while (0 < size--) {
 245                ch = *data++;
 246                if (nl_just_seen) {
 247                        fputs(set, file);
 248                        putc(prefix, file);
 249                }
 250                if (ch == '\n') {
 251                        nl_just_seen = 1;
 252                        fputs(reset, file);
 253                } else
 254                        nl_just_seen = 0;
 255                putc(ch, file);
 256        }
 257        if (!nl_just_seen)
 258                fprintf(file, "%s\n\\ No newline at end of file\n", reset);
 259}
 260
 261static void emit_rewrite_diff(const char *name_a,
 262                              const char *name_b,
 263                              struct diff_filespec *one,
 264                              struct diff_filespec *two,
 265                              const char *textconv_one,
 266                              const char *textconv_two,
 267                              struct diff_options *o)
 268{
 269        int lc_a, lc_b;
 270        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 271        const char *name_a_tab, *name_b_tab;
 272        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 273        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 274        const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
 275        const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
 276        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 277        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 278        const char *a_prefix, *b_prefix;
 279        const char *data_one, *data_two;
 280        size_t size_one, size_two;
 281
 282        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 283                a_prefix = o->b_prefix;
 284                b_prefix = o->a_prefix;
 285        } else {
 286                a_prefix = o->a_prefix;
 287                b_prefix = o->b_prefix;
 288        }
 289
 290        name_a += (*name_a == '/');
 291        name_b += (*name_b == '/');
 292        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 293        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 294
 295        strbuf_reset(&a_name);
 296        strbuf_reset(&b_name);
 297        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 298        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 299
 300        diff_populate_filespec(one, 0);
 301        diff_populate_filespec(two, 0);
 302        if (textconv_one) {
 303                data_one = run_textconv(textconv_one, one, &size_one);
 304                if (!data_one)
 305                        die("unable to read files to diff");
 306        }
 307        else {
 308                data_one = one->data;
 309                size_one = one->size;
 310        }
 311        if (textconv_two) {
 312                data_two = run_textconv(textconv_two, two, &size_two);
 313                if (!data_two)
 314                        die("unable to read files to diff");
 315        }
 316        else {
 317                data_two = two->data;
 318                size_two = two->size;
 319        }
 320
 321        lc_a = count_lines(data_one, size_one);
 322        lc_b = count_lines(data_two, size_two);
 323        fprintf(o->file,
 324                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 325                metainfo, a_name.buf, name_a_tab, reset,
 326                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 327        print_line_count(o->file, lc_a);
 328        fprintf(o->file, " +");
 329        print_line_count(o->file, lc_b);
 330        fprintf(o->file, " @@%s\n", reset);
 331        if (lc_a)
 332                copy_file_with_prefix(o->file, '-', data_one, size_one, old, reset);
 333        if (lc_b)
 334                copy_file_with_prefix(o->file, '+', data_two, size_two, new, reset);
 335}
 336
 337static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 338{
 339        if (!DIFF_FILE_VALID(one)) {
 340                mf->ptr = (char *)""; /* does not matter */
 341                mf->size = 0;
 342                return 0;
 343        }
 344        else if (diff_populate_filespec(one, 0))
 345                return -1;
 346
 347        mf->ptr = one->data;
 348        mf->size = one->size;
 349        return 0;
 350}
 351
 352struct diff_words_buffer {
 353        mmfile_t text;
 354        long alloc;
 355        struct diff_words_orig {
 356                const char *begin, *end;
 357        } *orig;
 358        int orig_nr, orig_alloc;
 359};
 360
 361static void diff_words_append(char *line, unsigned long len,
 362                struct diff_words_buffer *buffer)
 363{
 364        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 365        line++;
 366        len--;
 367        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 368        buffer->text.size += len;
 369        buffer->text.ptr[buffer->text.size] = '\0';
 370}
 371
 372struct diff_words_data {
 373        struct diff_words_buffer minus, plus;
 374        const char *current_plus;
 375        FILE *file;
 376        regex_t *word_regex;
 377};
 378
 379static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 380{
 381        struct diff_words_data *diff_words = priv;
 382        int minus_first, minus_len, plus_first, plus_len;
 383        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 384
 385        if (line[0] != '@' || parse_hunk_header(line, len,
 386                        &minus_first, &minus_len, &plus_first, &plus_len))
 387                return;
 388
 389        /* POSIX requires that first be decremented by one if len == 0... */
 390        if (minus_len) {
 391                minus_begin = diff_words->minus.orig[minus_first].begin;
 392                minus_end =
 393                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 394        } else
 395                minus_begin = minus_end =
 396                        diff_words->minus.orig[minus_first].end;
 397
 398        if (plus_len) {
 399                plus_begin = diff_words->plus.orig[plus_first].begin;
 400                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 401        } else
 402                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 403
 404        if (diff_words->current_plus != plus_begin)
 405                fwrite(diff_words->current_plus,
 406                                plus_begin - diff_words->current_plus, 1,
 407                                diff_words->file);
 408        if (minus_begin != minus_end)
 409                color_fwrite_lines(diff_words->file,
 410                                diff_get_color(1, DIFF_FILE_OLD),
 411                                minus_end - minus_begin, minus_begin);
 412        if (plus_begin != plus_end)
 413                color_fwrite_lines(diff_words->file,
 414                                diff_get_color(1, DIFF_FILE_NEW),
 415                                plus_end - plus_begin, plus_begin);
 416
 417        diff_words->current_plus = plus_end;
 418}
 419
 420/* This function starts looking at *begin, and returns 0 iff a word was found. */
 421static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 422                int *begin, int *end)
 423{
 424        if (word_regex && *begin < buffer->size) {
 425                regmatch_t match[1];
 426                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 427                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 428                                        '\n', match[0].rm_eo - match[0].rm_so);
 429                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 430                        *begin += match[0].rm_so;
 431                        return *begin >= *end;
 432                }
 433                return -1;
 434        }
 435
 436        /* find the next word */
 437        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 438                (*begin)++;
 439        if (*begin >= buffer->size)
 440                return -1;
 441
 442        /* find the end of the word */
 443        *end = *begin + 1;
 444        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 445                (*end)++;
 446
 447        return 0;
 448}
 449
 450/*
 451 * This function splits the words in buffer->text, stores the list with
 452 * newline separator into out, and saves the offsets of the original words
 453 * in buffer->orig.
 454 */
 455static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 456                regex_t *word_regex)
 457{
 458        int i, j;
 459        long alloc = 0;
 460
 461        out->size = 0;
 462        out->ptr = NULL;
 463
 464        /* fake an empty "0th" word */
 465        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 466        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 467        buffer->orig_nr = 1;
 468
 469        for (i = 0; i < buffer->text.size; i++) {
 470                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 471                        return;
 472
 473                /* store original boundaries */
 474                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 475                                buffer->orig_alloc);
 476                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 477                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 478                buffer->orig_nr++;
 479
 480                /* store one word */
 481                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 482                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 483                out->ptr[out->size + j - i] = '\n';
 484                out->size += j - i + 1;
 485
 486                i = j - 1;
 487        }
 488}
 489
 490/* this executes the word diff on the accumulated buffers */
 491static void diff_words_show(struct diff_words_data *diff_words)
 492{
 493        xpparam_t xpp;
 494        xdemitconf_t xecfg;
 495        xdemitcb_t ecb;
 496        mmfile_t minus, plus;
 497
 498        /* special case: only removal */
 499        if (!diff_words->plus.text.size) {
 500                color_fwrite_lines(diff_words->file,
 501                        diff_get_color(1, DIFF_FILE_OLD),
 502                        diff_words->minus.text.size, diff_words->minus.text.ptr);
 503                diff_words->minus.text.size = 0;
 504                return;
 505        }
 506
 507        diff_words->current_plus = diff_words->plus.text.ptr;
 508
 509        memset(&xpp, 0, sizeof(xpp));
 510        memset(&xecfg, 0, sizeof(xecfg));
 511        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 512        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 513        xpp.flags = XDF_NEED_MINIMAL;
 514        /* as only the hunk header will be parsed, we need a 0-context */
 515        xecfg.ctxlen = 0;
 516        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 517                      &xpp, &xecfg, &ecb);
 518        free(minus.ptr);
 519        free(plus.ptr);
 520        if (diff_words->current_plus != diff_words->plus.text.ptr +
 521                        diff_words->plus.text.size)
 522                fwrite(diff_words->current_plus,
 523                        diff_words->plus.text.ptr + diff_words->plus.text.size
 524                        - diff_words->current_plus, 1,
 525                        diff_words->file);
 526        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 527}
 528
 529typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 530
 531struct emit_callback {
 532        int nparents, color_diff;
 533        unsigned ws_rule;
 534        sane_truncate_fn truncate;
 535        const char **label_path;
 536        struct diff_words_data *diff_words;
 537        int *found_changesp;
 538        FILE *file;
 539};
 540
 541static void free_diff_words_data(struct emit_callback *ecbdata)
 542{
 543        if (ecbdata->diff_words) {
 544                /* flush buffers */
 545                if (ecbdata->diff_words->minus.text.size ||
 546                                ecbdata->diff_words->plus.text.size)
 547                        diff_words_show(ecbdata->diff_words);
 548
 549                free (ecbdata->diff_words->minus.text.ptr);
 550                free (ecbdata->diff_words->minus.orig);
 551                free (ecbdata->diff_words->plus.text.ptr);
 552                free (ecbdata->diff_words->plus.orig);
 553                free(ecbdata->diff_words->word_regex);
 554                free(ecbdata->diff_words);
 555                ecbdata->diff_words = NULL;
 556        }
 557}
 558
 559const char *diff_get_color(int diff_use_color, enum color_diff ix)
 560{
 561        if (diff_use_color)
 562                return diff_colors[ix];
 563        return "";
 564}
 565
 566static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
 567{
 568        int has_trailing_newline, has_trailing_carriage_return;
 569
 570        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 571        if (has_trailing_newline)
 572                len--;
 573        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 574        if (has_trailing_carriage_return)
 575                len--;
 576
 577        fputs(set, file);
 578        fwrite(line, len, 1, file);
 579        fputs(reset, file);
 580        if (has_trailing_carriage_return)
 581                fputc('\r', file);
 582        if (has_trailing_newline)
 583                fputc('\n', file);
 584}
 585
 586static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
 587{
 588        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 589        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 590
 591        if (!*ws)
 592                emit_line(ecbdata->file, set, reset, line, len);
 593        else {
 594                /* Emit just the prefix, then the rest. */
 595                emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
 596                ws_check_emit(line + ecbdata->nparents,
 597                              len - ecbdata->nparents, ecbdata->ws_rule,
 598                              ecbdata->file, set, reset, ws);
 599        }
 600}
 601
 602static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 603{
 604        const char *cp;
 605        unsigned long allot;
 606        size_t l = len;
 607
 608        if (ecb->truncate)
 609                return ecb->truncate(line, len);
 610        cp = line;
 611        allot = l;
 612        while (0 < l) {
 613                (void) utf8_width(&cp, &l);
 614                if (!cp)
 615                        break; /* truncated in the middle? */
 616        }
 617        return allot - l;
 618}
 619
 620static void fn_out_consume(void *priv, char *line, unsigned long len)
 621{
 622        int i;
 623        int color;
 624        struct emit_callback *ecbdata = priv;
 625        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 626        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 627        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 628
 629        *(ecbdata->found_changesp) = 1;
 630
 631        if (ecbdata->label_path[0]) {
 632                const char *name_a_tab, *name_b_tab;
 633
 634                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 635                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 636
 637                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 638                        meta, ecbdata->label_path[0], reset, name_a_tab);
 639                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 640                        meta, ecbdata->label_path[1], reset, name_b_tab);
 641                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 642        }
 643
 644        if (diff_suppress_blank_empty
 645            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 646                line[0] = '\n';
 647                len = 1;
 648        }
 649
 650        /* This is not really necessary for now because
 651         * this codepath only deals with two-way diffs.
 652         */
 653        for (i = 0; i < len && line[i] == '@'; i++)
 654                ;
 655        if (2 <= i && i < len && line[i] == ' ') {
 656                ecbdata->nparents = i - 1;
 657                len = sane_truncate_line(ecbdata, line, len);
 658                emit_line(ecbdata->file,
 659                          diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
 660                          reset, line, len);
 661                if (line[len-1] != '\n')
 662                        putc('\n', ecbdata->file);
 663                return;
 664        }
 665
 666        if (len < ecbdata->nparents) {
 667                emit_line(ecbdata->file, reset, reset, line, len);
 668                return;
 669        }
 670
 671        color = DIFF_PLAIN;
 672        if (ecbdata->diff_words && ecbdata->nparents != 1)
 673                /* fall back to normal diff */
 674                free_diff_words_data(ecbdata);
 675        if (ecbdata->diff_words) {
 676                if (line[0] == '-') {
 677                        diff_words_append(line, len,
 678                                          &ecbdata->diff_words->minus);
 679                        return;
 680                } else if (line[0] == '+') {
 681                        diff_words_append(line, len,
 682                                          &ecbdata->diff_words->plus);
 683                        return;
 684                }
 685                if (ecbdata->diff_words->minus.text.size ||
 686                    ecbdata->diff_words->plus.text.size)
 687                        diff_words_show(ecbdata->diff_words);
 688                line++;
 689                len--;
 690                emit_line(ecbdata->file, plain, reset, line, len);
 691                return;
 692        }
 693        for (i = 0; i < ecbdata->nparents && len; i++) {
 694                if (line[i] == '-')
 695                        color = DIFF_FILE_OLD;
 696                else if (line[i] == '+')
 697                        color = DIFF_FILE_NEW;
 698        }
 699
 700        if (color != DIFF_FILE_NEW) {
 701                emit_line(ecbdata->file,
 702                          diff_get_color(ecbdata->color_diff, color),
 703                          reset, line, len);
 704                return;
 705        }
 706        emit_add_line(reset, ecbdata, line, len);
 707}
 708
 709static char *pprint_rename(const char *a, const char *b)
 710{
 711        const char *old = a;
 712        const char *new = b;
 713        struct strbuf name = STRBUF_INIT;
 714        int pfx_length, sfx_length;
 715        int len_a = strlen(a);
 716        int len_b = strlen(b);
 717        int a_midlen, b_midlen;
 718        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 719        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 720
 721        if (qlen_a || qlen_b) {
 722                quote_c_style(a, &name, NULL, 0);
 723                strbuf_addstr(&name, " => ");
 724                quote_c_style(b, &name, NULL, 0);
 725                return strbuf_detach(&name, NULL);
 726        }
 727
 728        /* Find common prefix */
 729        pfx_length = 0;
 730        while (*old && *new && *old == *new) {
 731                if (*old == '/')
 732                        pfx_length = old - a + 1;
 733                old++;
 734                new++;
 735        }
 736
 737        /* Find common suffix */
 738        old = a + len_a;
 739        new = b + len_b;
 740        sfx_length = 0;
 741        while (a <= old && b <= new && *old == *new) {
 742                if (*old == '/')
 743                        sfx_length = len_a - (old - a);
 744                old--;
 745                new--;
 746        }
 747
 748        /*
 749         * pfx{mid-a => mid-b}sfx
 750         * {pfx-a => pfx-b}sfx
 751         * pfx{sfx-a => sfx-b}
 752         * name-a => name-b
 753         */
 754        a_midlen = len_a - pfx_length - sfx_length;
 755        b_midlen = len_b - pfx_length - sfx_length;
 756        if (a_midlen < 0)
 757                a_midlen = 0;
 758        if (b_midlen < 0)
 759                b_midlen = 0;
 760
 761        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 762        if (pfx_length + sfx_length) {
 763                strbuf_add(&name, a, pfx_length);
 764                strbuf_addch(&name, '{');
 765        }
 766        strbuf_add(&name, a + pfx_length, a_midlen);
 767        strbuf_addstr(&name, " => ");
 768        strbuf_add(&name, b + pfx_length, b_midlen);
 769        if (pfx_length + sfx_length) {
 770                strbuf_addch(&name, '}');
 771                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 772        }
 773        return strbuf_detach(&name, NULL);
 774}
 775
 776struct diffstat_t {
 777        int nr;
 778        int alloc;
 779        struct diffstat_file {
 780                char *from_name;
 781                char *name;
 782                char *print_name;
 783                unsigned is_unmerged:1;
 784                unsigned is_binary:1;
 785                unsigned is_renamed:1;
 786                unsigned int added, deleted;
 787        } **files;
 788};
 789
 790static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 791                                          const char *name_a,
 792                                          const char *name_b)
 793{
 794        struct diffstat_file *x;
 795        x = xcalloc(sizeof (*x), 1);
 796        if (diffstat->nr == diffstat->alloc) {
 797                diffstat->alloc = alloc_nr(diffstat->alloc);
 798                diffstat->files = xrealloc(diffstat->files,
 799                                diffstat->alloc * sizeof(x));
 800        }
 801        diffstat->files[diffstat->nr++] = x;
 802        if (name_b) {
 803                x->from_name = xstrdup(name_a);
 804                x->name = xstrdup(name_b);
 805                x->is_renamed = 1;
 806        }
 807        else {
 808                x->from_name = NULL;
 809                x->name = xstrdup(name_a);
 810        }
 811        return x;
 812}
 813
 814static void diffstat_consume(void *priv, char *line, unsigned long len)
 815{
 816        struct diffstat_t *diffstat = priv;
 817        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 818
 819        if (line[0] == '+')
 820                x->added++;
 821        else if (line[0] == '-')
 822                x->deleted++;
 823}
 824
 825const char mime_boundary_leader[] = "------------";
 826
 827static int scale_linear(int it, int width, int max_change)
 828{
 829        /*
 830         * make sure that at least one '-' is printed if there were deletions,
 831         * and likewise for '+'.
 832         */
 833        if (max_change < 2)
 834                return it;
 835        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 836}
 837
 838static void show_name(FILE *file,
 839                      const char *prefix, const char *name, int len,
 840                      const char *reset, const char *set)
 841{
 842        fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
 843}
 844
 845static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
 846{
 847        if (cnt <= 0)
 848                return;
 849        fprintf(file, "%s", set);
 850        while (cnt--)
 851                putc(ch, file);
 852        fprintf(file, "%s", reset);
 853}
 854
 855static void fill_print_name(struct diffstat_file *file)
 856{
 857        char *pname;
 858
 859        if (file->print_name)
 860                return;
 861
 862        if (!file->is_renamed) {
 863                struct strbuf buf = STRBUF_INIT;
 864                if (quote_c_style(file->name, &buf, NULL, 0)) {
 865                        pname = strbuf_detach(&buf, NULL);
 866                } else {
 867                        pname = file->name;
 868                        strbuf_release(&buf);
 869                }
 870        } else {
 871                pname = pprint_rename(file->from_name, file->name);
 872        }
 873        file->print_name = pname;
 874}
 875
 876static void show_stats(struct diffstat_t* data, struct diff_options *options)
 877{
 878        int i, len, add, del, adds = 0, dels = 0;
 879        int max_change = 0, max_len = 0;
 880        int total_files = data->nr;
 881        int width, name_width;
 882        const char *reset, *set, *add_c, *del_c;
 883
 884        if (data->nr == 0)
 885                return;
 886
 887        width = options->stat_width ? options->stat_width : 80;
 888        name_width = options->stat_name_width ? options->stat_name_width : 50;
 889
 890        /* Sanity: give at least 5 columns to the graph,
 891         * but leave at least 10 columns for the name.
 892         */
 893        if (width < 25)
 894                width = 25;
 895        if (name_width < 10)
 896                name_width = 10;
 897        else if (width < name_width + 15)
 898                name_width = width - 15;
 899
 900        /* Find the longest filename and max number of changes */
 901        reset = diff_get_color_opt(options, DIFF_RESET);
 902        set   = diff_get_color_opt(options, DIFF_PLAIN);
 903        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
 904        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
 905
 906        for (i = 0; i < data->nr; i++) {
 907                struct diffstat_file *file = data->files[i];
 908                int change = file->added + file->deleted;
 909                fill_print_name(file);
 910                len = strlen(file->print_name);
 911                if (max_len < len)
 912                        max_len = len;
 913
 914                if (file->is_binary || file->is_unmerged)
 915                        continue;
 916                if (max_change < change)
 917                        max_change = change;
 918        }
 919
 920        /* Compute the width of the graph part;
 921         * 10 is for one blank at the beginning of the line plus
 922         * " | count " between the name and the graph.
 923         *
 924         * From here on, name_width is the width of the name area,
 925         * and width is the width of the graph area.
 926         */
 927        name_width = (name_width < max_len) ? name_width : max_len;
 928        if (width < (name_width + 10) + max_change)
 929                width = width - (name_width + 10);
 930        else
 931                width = max_change;
 932
 933        for (i = 0; i < data->nr; i++) {
 934                const char *prefix = "";
 935                char *name = data->files[i]->print_name;
 936                int added = data->files[i]->added;
 937                int deleted = data->files[i]->deleted;
 938                int name_len;
 939
 940                /*
 941                 * "scale" the filename
 942                 */
 943                len = name_width;
 944                name_len = strlen(name);
 945                if (name_width < name_len) {
 946                        char *slash;
 947                        prefix = "...";
 948                        len -= 3;
 949                        name += name_len - len;
 950                        slash = strchr(name, '/');
 951                        if (slash)
 952                                name = slash;
 953                }
 954
 955                if (data->files[i]->is_binary) {
 956                        show_name(options->file, prefix, name, len, reset, set);
 957                        fprintf(options->file, "  Bin ");
 958                        fprintf(options->file, "%s%d%s", del_c, deleted, reset);
 959                        fprintf(options->file, " -> ");
 960                        fprintf(options->file, "%s%d%s", add_c, added, reset);
 961                        fprintf(options->file, " bytes");
 962                        fprintf(options->file, "\n");
 963                        continue;
 964                }
 965                else if (data->files[i]->is_unmerged) {
 966                        show_name(options->file, prefix, name, len, reset, set);
 967                        fprintf(options->file, "  Unmerged\n");
 968                        continue;
 969                }
 970                else if (!data->files[i]->is_renamed &&
 971                         (added + deleted == 0)) {
 972                        total_files--;
 973                        continue;
 974                }
 975
 976                /*
 977                 * scale the add/delete
 978                 */
 979                add = added;
 980                del = deleted;
 981                adds += add;
 982                dels += del;
 983
 984                if (width <= max_change) {
 985                        add = scale_linear(add, width, max_change);
 986                        del = scale_linear(del, width, max_change);
 987                }
 988                show_name(options->file, prefix, name, len, reset, set);
 989                fprintf(options->file, "%5d%s", added + deleted,
 990                                added + deleted ? " " : "");
 991                show_graph(options->file, '+', add, add_c, reset);
 992                show_graph(options->file, '-', del, del_c, reset);
 993                fprintf(options->file, "\n");
 994        }
 995        fprintf(options->file,
 996               "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
 997               set, total_files, adds, dels, reset);
 998}
 999
1000static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
1001{
1002        int i, adds = 0, dels = 0, total_files = data->nr;
1003
1004        if (data->nr == 0)
1005                return;
1006
1007        for (i = 0; i < data->nr; i++) {
1008                if (!data->files[i]->is_binary &&
1009                    !data->files[i]->is_unmerged) {
1010                        int added = data->files[i]->added;
1011                        int deleted= data->files[i]->deleted;
1012                        if (!data->files[i]->is_renamed &&
1013                            (added + deleted == 0)) {
1014                                total_files--;
1015                        } else {
1016                                adds += added;
1017                                dels += deleted;
1018                        }
1019                }
1020        }
1021        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1022               total_files, adds, dels);
1023}
1024
1025static void show_numstat(struct diffstat_t* data, struct diff_options *options)
1026{
1027        int i;
1028
1029        if (data->nr == 0)
1030                return;
1031
1032        for (i = 0; i < data->nr; i++) {
1033                struct diffstat_file *file = data->files[i];
1034
1035                if (file->is_binary)
1036                        fprintf(options->file, "-\t-\t");
1037                else
1038                        fprintf(options->file,
1039                                "%d\t%d\t", file->added, file->deleted);
1040                if (options->line_termination) {
1041                        fill_print_name(file);
1042                        if (!file->is_renamed)
1043                                write_name_quoted(file->name, options->file,
1044                                                  options->line_termination);
1045                        else {
1046                                fputs(file->print_name, options->file);
1047                                putc(options->line_termination, options->file);
1048                        }
1049                } else {
1050                        if (file->is_renamed) {
1051                                putc('\0', options->file);
1052                                write_name_quoted(file->from_name, options->file, '\0');
1053                        }
1054                        write_name_quoted(file->name, options->file, '\0');
1055                }
1056        }
1057}
1058
1059struct dirstat_file {
1060        const char *name;
1061        unsigned long changed;
1062};
1063
1064struct dirstat_dir {
1065        struct dirstat_file *files;
1066        int alloc, nr, percent, cumulative;
1067};
1068
1069static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1070{
1071        unsigned long this_dir = 0;
1072        unsigned int sources = 0;
1073
1074        while (dir->nr) {
1075                struct dirstat_file *f = dir->files;
1076                int namelen = strlen(f->name);
1077                unsigned long this;
1078                char *slash;
1079
1080                if (namelen < baselen)
1081                        break;
1082                if (memcmp(f->name, base, baselen))
1083                        break;
1084                slash = strchr(f->name + baselen, '/');
1085                if (slash) {
1086                        int newbaselen = slash + 1 - f->name;
1087                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1088                        sources++;
1089                } else {
1090                        this = f->changed;
1091                        dir->files++;
1092                        dir->nr--;
1093                        sources += 2;
1094                }
1095                this_dir += this;
1096        }
1097
1098        /*
1099         * We don't report dirstat's for
1100         *  - the top level
1101         *  - or cases where everything came from a single directory
1102         *    under this directory (sources == 1).
1103         */
1104        if (baselen && sources != 1) {
1105                int permille = this_dir * 1000 / changed;
1106                if (permille) {
1107                        int percent = permille / 10;
1108                        if (percent >= dir->percent) {
1109                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1110                                if (!dir->cumulative)
1111                                        return 0;
1112                        }
1113                }
1114        }
1115        return this_dir;
1116}
1117
1118static int dirstat_compare(const void *_a, const void *_b)
1119{
1120        const struct dirstat_file *a = _a;
1121        const struct dirstat_file *b = _b;
1122        return strcmp(a->name, b->name);
1123}
1124
1125static void show_dirstat(struct diff_options *options)
1126{
1127        int i;
1128        unsigned long changed;
1129        struct dirstat_dir dir;
1130        struct diff_queue_struct *q = &diff_queued_diff;
1131
1132        dir.files = NULL;
1133        dir.alloc = 0;
1134        dir.nr = 0;
1135        dir.percent = options->dirstat_percent;
1136        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1137
1138        changed = 0;
1139        for (i = 0; i < q->nr; i++) {
1140                struct diff_filepair *p = q->queue[i];
1141                const char *name;
1142                unsigned long copied, added, damage;
1143
1144                name = p->one->path ? p->one->path : p->two->path;
1145
1146                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1147                        diff_populate_filespec(p->one, 0);
1148                        diff_populate_filespec(p->two, 0);
1149                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1150                                               &copied, &added);
1151                        diff_free_filespec_data(p->one);
1152                        diff_free_filespec_data(p->two);
1153                } else if (DIFF_FILE_VALID(p->one)) {
1154                        diff_populate_filespec(p->one, 1);
1155                        copied = added = 0;
1156                        diff_free_filespec_data(p->one);
1157                } else if (DIFF_FILE_VALID(p->two)) {
1158                        diff_populate_filespec(p->two, 1);
1159                        copied = 0;
1160                        added = p->two->size;
1161                        diff_free_filespec_data(p->two);
1162                } else
1163                        continue;
1164
1165                /*
1166                 * Original minus copied is the removed material,
1167                 * added is the new material.  They are both damages
1168                 * made to the preimage. In --dirstat-by-file mode, count
1169                 * damaged files, not damaged lines. This is done by
1170                 * counting only a single damaged line per file.
1171                 */
1172                damage = (p->one->size - copied) + added;
1173                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1174                        damage = 1;
1175
1176                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1177                dir.files[dir.nr].name = name;
1178                dir.files[dir.nr].changed = damage;
1179                changed += damage;
1180                dir.nr++;
1181        }
1182
1183        /* This can happen even with many files, if everything was renames */
1184        if (!changed)
1185                return;
1186
1187        /* Show all directories with more than x% of the changes */
1188        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1189        gather_dirstat(options->file, &dir, changed, "", 0);
1190}
1191
1192static void free_diffstat_info(struct diffstat_t *diffstat)
1193{
1194        int i;
1195        for (i = 0; i < diffstat->nr; i++) {
1196                struct diffstat_file *f = diffstat->files[i];
1197                if (f->name != f->print_name)
1198                        free(f->print_name);
1199                free(f->name);
1200                free(f->from_name);
1201                free(f);
1202        }
1203        free(diffstat->files);
1204}
1205
1206struct checkdiff_t {
1207        const char *filename;
1208        int lineno;
1209        struct diff_options *o;
1210        unsigned ws_rule;
1211        unsigned status;
1212        int trailing_blanks_start;
1213};
1214
1215static int is_conflict_marker(const char *line, unsigned long len)
1216{
1217        char firstchar;
1218        int cnt;
1219
1220        if (len < 8)
1221                return 0;
1222        firstchar = line[0];
1223        switch (firstchar) {
1224        case '=': case '>': case '<':
1225                break;
1226        default:
1227                return 0;
1228        }
1229        for (cnt = 1; cnt < 7; cnt++)
1230                if (line[cnt] != firstchar)
1231                        return 0;
1232        /* line[0] thru line[6] are same as firstchar */
1233        if (firstchar == '=') {
1234                /* divider between ours and theirs? */
1235                if (len != 8 || line[7] != '\n')
1236                        return 0;
1237        } else if (len < 8 || !isspace(line[7])) {
1238                /* not divider before ours nor after theirs */
1239                return 0;
1240        }
1241        return 1;
1242}
1243
1244static void checkdiff_consume(void *priv, char *line, unsigned long len)
1245{
1246        struct checkdiff_t *data = priv;
1247        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1248        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1249        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1250        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1251        char *err;
1252
1253        if (line[0] == '+') {
1254                unsigned bad;
1255                data->lineno++;
1256                if (!ws_blank_line(line + 1, len - 1, data->ws_rule))
1257                        data->trailing_blanks_start = 0;
1258                else if (!data->trailing_blanks_start)
1259                        data->trailing_blanks_start = data->lineno;
1260                if (is_conflict_marker(line + 1, len - 1)) {
1261                        data->status |= 1;
1262                        fprintf(data->o->file,
1263                                "%s:%d: leftover conflict marker\n",
1264                                data->filename, data->lineno);
1265                }
1266                bad = ws_check(line + 1, len - 1, data->ws_rule);
1267                if (!bad)
1268                        return;
1269                data->status |= bad;
1270                err = whitespace_error_string(bad);
1271                fprintf(data->o->file, "%s:%d: %s.\n",
1272                        data->filename, data->lineno, err);
1273                free(err);
1274                emit_line(data->o->file, set, reset, line, 1);
1275                ws_check_emit(line + 1, len - 1, data->ws_rule,
1276                              data->o->file, set, reset, ws);
1277        } else if (line[0] == ' ') {
1278                data->lineno++;
1279                data->trailing_blanks_start = 0;
1280        } else if (line[0] == '@') {
1281                char *plus = strchr(line, '+');
1282                if (plus)
1283                        data->lineno = strtol(plus, NULL, 10) - 1;
1284                else
1285                        die("invalid diff");
1286                data->trailing_blanks_start = 0;
1287        }
1288}
1289
1290static unsigned char *deflate_it(char *data,
1291                                 unsigned long size,
1292                                 unsigned long *result_size)
1293{
1294        int bound;
1295        unsigned char *deflated;
1296        z_stream stream;
1297
1298        memset(&stream, 0, sizeof(stream));
1299        deflateInit(&stream, zlib_compression_level);
1300        bound = deflateBound(&stream, size);
1301        deflated = xmalloc(bound);
1302        stream.next_out = deflated;
1303        stream.avail_out = bound;
1304
1305        stream.next_in = (unsigned char *)data;
1306        stream.avail_in = size;
1307        while (deflate(&stream, Z_FINISH) == Z_OK)
1308                ; /* nothing */
1309        deflateEnd(&stream);
1310        *result_size = stream.total_out;
1311        return deflated;
1312}
1313
1314static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1315{
1316        void *cp;
1317        void *delta;
1318        void *deflated;
1319        void *data;
1320        unsigned long orig_size;
1321        unsigned long delta_size;
1322        unsigned long deflate_size;
1323        unsigned long data_size;
1324
1325        /* We could do deflated delta, or we could do just deflated two,
1326         * whichever is smaller.
1327         */
1328        delta = NULL;
1329        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1330        if (one->size && two->size) {
1331                delta = diff_delta(one->ptr, one->size,
1332                                   two->ptr, two->size,
1333                                   &delta_size, deflate_size);
1334                if (delta) {
1335                        void *to_free = delta;
1336                        orig_size = delta_size;
1337                        delta = deflate_it(delta, delta_size, &delta_size);
1338                        free(to_free);
1339                }
1340        }
1341
1342        if (delta && delta_size < deflate_size) {
1343                fprintf(file, "delta %lu\n", orig_size);
1344                free(deflated);
1345                data = delta;
1346                data_size = delta_size;
1347        }
1348        else {
1349                fprintf(file, "literal %lu\n", two->size);
1350                free(delta);
1351                data = deflated;
1352                data_size = deflate_size;
1353        }
1354
1355        /* emit data encoded in base85 */
1356        cp = data;
1357        while (data_size) {
1358                int bytes = (52 < data_size) ? 52 : data_size;
1359                char line[70];
1360                data_size -= bytes;
1361                if (bytes <= 26)
1362                        line[0] = bytes + 'A' - 1;
1363                else
1364                        line[0] = bytes - 26 + 'a' - 1;
1365                encode_85(line + 1, cp, bytes);
1366                cp = (char *) cp + bytes;
1367                fputs(line, file);
1368                fputc('\n', file);
1369        }
1370        fprintf(file, "\n");
1371        free(data);
1372}
1373
1374static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1375{
1376        fprintf(file, "GIT binary patch\n");
1377        emit_binary_diff_body(file, one, two);
1378        emit_binary_diff_body(file, two, one);
1379}
1380
1381static void diff_filespec_load_driver(struct diff_filespec *one)
1382{
1383        if (!one->driver)
1384                one->driver = userdiff_find_by_path(one->path);
1385        if (!one->driver)
1386                one->driver = userdiff_find_by_name("default");
1387}
1388
1389int diff_filespec_is_binary(struct diff_filespec *one)
1390{
1391        if (one->is_binary == -1) {
1392                diff_filespec_load_driver(one);
1393                if (one->driver->binary != -1)
1394                        one->is_binary = one->driver->binary;
1395                else {
1396                        if (!one->data && DIFF_FILE_VALID(one))
1397                                diff_populate_filespec(one, 0);
1398                        if (one->data)
1399                                one->is_binary = buffer_is_binary(one->data,
1400                                                one->size);
1401                        if (one->is_binary == -1)
1402                                one->is_binary = 0;
1403                }
1404        }
1405        return one->is_binary;
1406}
1407
1408static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1409{
1410        diff_filespec_load_driver(one);
1411        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1412}
1413
1414static const char *userdiff_word_regex(struct diff_filespec *one)
1415{
1416        diff_filespec_load_driver(one);
1417        return one->driver->word_regex;
1418}
1419
1420void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1421{
1422        if (!options->a_prefix)
1423                options->a_prefix = a;
1424        if (!options->b_prefix)
1425                options->b_prefix = b;
1426}
1427
1428static const char *get_textconv(struct diff_filespec *one)
1429{
1430        if (!DIFF_FILE_VALID(one))
1431                return NULL;
1432        if (!S_ISREG(one->mode))
1433                return NULL;
1434        diff_filespec_load_driver(one);
1435        return one->driver->textconv;
1436}
1437
1438static void builtin_diff(const char *name_a,
1439                         const char *name_b,
1440                         struct diff_filespec *one,
1441                         struct diff_filespec *two,
1442                         const char *xfrm_msg,
1443                         struct diff_options *o,
1444                         int complete_rewrite)
1445{
1446        mmfile_t mf1, mf2;
1447        const char *lbl[2];
1448        char *a_one, *b_two;
1449        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1450        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1451        const char *a_prefix, *b_prefix;
1452        const char *textconv_one = NULL, *textconv_two = NULL;
1453
1454        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1455                textconv_one = get_textconv(one);
1456                textconv_two = get_textconv(two);
1457        }
1458
1459        diff_set_mnemonic_prefix(o, "a/", "b/");
1460        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1461                a_prefix = o->b_prefix;
1462                b_prefix = o->a_prefix;
1463        } else {
1464                a_prefix = o->a_prefix;
1465                b_prefix = o->b_prefix;
1466        }
1467
1468        /* Never use a non-valid filename anywhere if at all possible */
1469        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1470        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1471
1472        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1473        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1474        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1475        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1476        fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1477        if (lbl[0][0] == '/') {
1478                /* /dev/null */
1479                fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1480                if (xfrm_msg && xfrm_msg[0])
1481                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1482        }
1483        else if (lbl[1][0] == '/') {
1484                fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1485                if (xfrm_msg && xfrm_msg[0])
1486                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1487        }
1488        else {
1489                if (one->mode != two->mode) {
1490                        fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1491                        fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1492                }
1493                if (xfrm_msg && xfrm_msg[0])
1494                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1495                /*
1496                 * we do not run diff between different kind
1497                 * of objects.
1498                 */
1499                if ((one->mode ^ two->mode) & S_IFMT)
1500                        goto free_ab_and_return;
1501                if (complete_rewrite &&
1502                    (textconv_one || !diff_filespec_is_binary(one)) &&
1503                    (textconv_two || !diff_filespec_is_binary(two))) {
1504                        emit_rewrite_diff(name_a, name_b, one, two,
1505                                                textconv_one, textconv_two, o);
1506                        o->found_changes = 1;
1507                        goto free_ab_and_return;
1508                }
1509        }
1510
1511        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1512                die("unable to read files to diff");
1513
1514        if (!DIFF_OPT_TST(o, TEXT) &&
1515            ( (diff_filespec_is_binary(one) && !textconv_one) ||
1516              (diff_filespec_is_binary(two) && !textconv_two) )) {
1517                /* Quite common confusing case */
1518                if (mf1.size == mf2.size &&
1519                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1520                        goto free_ab_and_return;
1521                if (DIFF_OPT_TST(o, BINARY))
1522                        emit_binary_diff(o->file, &mf1, &mf2);
1523                else
1524                        fprintf(o->file, "Binary files %s and %s differ\n",
1525                                lbl[0], lbl[1]);
1526                o->found_changes = 1;
1527        }
1528        else {
1529                /* Crazy xdl interfaces.. */
1530                const char *diffopts = getenv("GIT_DIFF_OPTS");
1531                xpparam_t xpp;
1532                xdemitconf_t xecfg;
1533                xdemitcb_t ecb;
1534                struct emit_callback ecbdata;
1535                const struct userdiff_funcname *pe;
1536
1537                if (textconv_one) {
1538                        size_t size;
1539                        mf1.ptr = run_textconv(textconv_one, one, &size);
1540                        if (!mf1.ptr)
1541                                die("unable to read files to diff");
1542                        mf1.size = size;
1543                }
1544                if (textconv_two) {
1545                        size_t size;
1546                        mf2.ptr = run_textconv(textconv_two, two, &size);
1547                        if (!mf2.ptr)
1548                                die("unable to read files to diff");
1549                        mf2.size = size;
1550                }
1551
1552                pe = diff_funcname_pattern(one);
1553                if (!pe)
1554                        pe = diff_funcname_pattern(two);
1555
1556                memset(&xpp, 0, sizeof(xpp));
1557                memset(&xecfg, 0, sizeof(xecfg));
1558                memset(&ecbdata, 0, sizeof(ecbdata));
1559                ecbdata.label_path = lbl;
1560                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1561                ecbdata.found_changesp = &o->found_changes;
1562                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1563                ecbdata.file = o->file;
1564                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1565                xecfg.ctxlen = o->context;
1566                xecfg.interhunkctxlen = o->interhunkcontext;
1567                xecfg.flags = XDL_EMIT_FUNCNAMES;
1568                if (pe)
1569                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1570                if (!diffopts)
1571                        ;
1572                else if (!prefixcmp(diffopts, "--unified="))
1573                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1574                else if (!prefixcmp(diffopts, "-u"))
1575                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1576                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1577                        ecbdata.diff_words =
1578                                xcalloc(1, sizeof(struct diff_words_data));
1579                        ecbdata.diff_words->file = o->file;
1580                        if (!o->word_regex)
1581                                o->word_regex = userdiff_word_regex(one);
1582                        if (!o->word_regex)
1583                                o->word_regex = userdiff_word_regex(two);
1584                        if (!o->word_regex)
1585                                o->word_regex = diff_word_regex_cfg;
1586                        if (o->word_regex) {
1587                                ecbdata.diff_words->word_regex = (regex_t *)
1588                                        xmalloc(sizeof(regex_t));
1589                                if (regcomp(ecbdata.diff_words->word_regex,
1590                                                o->word_regex,
1591                                                REG_EXTENDED | REG_NEWLINE))
1592                                        die ("Invalid regular expression: %s",
1593                                                        o->word_regex);
1594                        }
1595                }
1596                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1597                              &xpp, &xecfg, &ecb);
1598                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1599                        free_diff_words_data(&ecbdata);
1600                if (textconv_one)
1601                        free(mf1.ptr);
1602                if (textconv_two)
1603                        free(mf2.ptr);
1604        }
1605
1606 free_ab_and_return:
1607        diff_free_filespec_data(one);
1608        diff_free_filespec_data(two);
1609        free(a_one);
1610        free(b_two);
1611        return;
1612}
1613
1614static void builtin_diffstat(const char *name_a, const char *name_b,
1615                             struct diff_filespec *one,
1616                             struct diff_filespec *two,
1617                             struct diffstat_t *diffstat,
1618                             struct diff_options *o,
1619                             int complete_rewrite)
1620{
1621        mmfile_t mf1, mf2;
1622        struct diffstat_file *data;
1623
1624        data = diffstat_add(diffstat, name_a, name_b);
1625
1626        if (!one || !two) {
1627                data->is_unmerged = 1;
1628                return;
1629        }
1630        if (complete_rewrite) {
1631                diff_populate_filespec(one, 0);
1632                diff_populate_filespec(two, 0);
1633                data->deleted = count_lines(one->data, one->size);
1634                data->added = count_lines(two->data, two->size);
1635                goto free_and_return;
1636        }
1637        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1638                die("unable to read files to diff");
1639
1640        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1641                data->is_binary = 1;
1642                data->added = mf2.size;
1643                data->deleted = mf1.size;
1644        } else {
1645                /* Crazy xdl interfaces.. */
1646                xpparam_t xpp;
1647                xdemitconf_t xecfg;
1648                xdemitcb_t ecb;
1649
1650                memset(&xpp, 0, sizeof(xpp));
1651                memset(&xecfg, 0, sizeof(xecfg));
1652                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1653                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1654                              &xpp, &xecfg, &ecb);
1655        }
1656
1657 free_and_return:
1658        diff_free_filespec_data(one);
1659        diff_free_filespec_data(two);
1660}
1661
1662static void builtin_checkdiff(const char *name_a, const char *name_b,
1663                              const char *attr_path,
1664                              struct diff_filespec *one,
1665                              struct diff_filespec *two,
1666                              struct diff_options *o)
1667{
1668        mmfile_t mf1, mf2;
1669        struct checkdiff_t data;
1670
1671        if (!two)
1672                return;
1673
1674        memset(&data, 0, sizeof(data));
1675        data.filename = name_b ? name_b : name_a;
1676        data.lineno = 0;
1677        data.o = o;
1678        data.ws_rule = whitespace_rule(attr_path);
1679
1680        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1681                die("unable to read files to diff");
1682
1683        /*
1684         * All the other codepaths check both sides, but not checking
1685         * the "old" side here is deliberate.  We are checking the newly
1686         * introduced changes, and as long as the "new" side is text, we
1687         * can and should check what it introduces.
1688         */
1689        if (diff_filespec_is_binary(two))
1690                goto free_and_return;
1691        else {
1692                /* Crazy xdl interfaces.. */
1693                xpparam_t xpp;
1694                xdemitconf_t xecfg;
1695                xdemitcb_t ecb;
1696
1697                memset(&xpp, 0, sizeof(xpp));
1698                memset(&xecfg, 0, sizeof(xecfg));
1699                xecfg.ctxlen = 1; /* at least one context line */
1700                xpp.flags = XDF_NEED_MINIMAL;
1701                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1702                              &xpp, &xecfg, &ecb);
1703
1704                if ((data.ws_rule & WS_TRAILING_SPACE) &&
1705                    data.trailing_blanks_start) {
1706                        fprintf(o->file, "%s:%d: ends with blank lines.\n",
1707                                data.filename, data.trailing_blanks_start);
1708                        data.status = 1; /* report errors */
1709                }
1710        }
1711 free_and_return:
1712        diff_free_filespec_data(one);
1713        diff_free_filespec_data(two);
1714        if (data.status)
1715                DIFF_OPT_SET(o, CHECK_FAILED);
1716}
1717
1718struct diff_filespec *alloc_filespec(const char *path)
1719{
1720        int namelen = strlen(path);
1721        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1722
1723        memset(spec, 0, sizeof(*spec));
1724        spec->path = (char *)(spec + 1);
1725        memcpy(spec->path, path, namelen+1);
1726        spec->count = 1;
1727        spec->is_binary = -1;
1728        return spec;
1729}
1730
1731void free_filespec(struct diff_filespec *spec)
1732{
1733        if (!--spec->count) {
1734                diff_free_filespec_data(spec);
1735                free(spec);
1736        }
1737}
1738
1739void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1740                   unsigned short mode)
1741{
1742        if (mode) {
1743                spec->mode = canon_mode(mode);
1744                hashcpy(spec->sha1, sha1);
1745                spec->sha1_valid = !is_null_sha1(sha1);
1746        }
1747}
1748
1749/*
1750 * Given a name and sha1 pair, if the index tells us the file in
1751 * the work tree has that object contents, return true, so that
1752 * prepare_temp_file() does not have to inflate and extract.
1753 */
1754static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1755{
1756        struct cache_entry *ce;
1757        struct stat st;
1758        int pos, len;
1759
1760        /*
1761         * We do not read the cache ourselves here, because the
1762         * benchmark with my previous version that always reads cache
1763         * shows that it makes things worse for diff-tree comparing
1764         * two linux-2.6 kernel trees in an already checked out work
1765         * tree.  This is because most diff-tree comparisons deal with
1766         * only a small number of files, while reading the cache is
1767         * expensive for a large project, and its cost outweighs the
1768         * savings we get by not inflating the object to a temporary
1769         * file.  Practically, this code only helps when we are used
1770         * by diff-cache --cached, which does read the cache before
1771         * calling us.
1772         */
1773        if (!active_cache)
1774                return 0;
1775
1776        /* We want to avoid the working directory if our caller
1777         * doesn't need the data in a normal file, this system
1778         * is rather slow with its stat/open/mmap/close syscalls,
1779         * and the object is contained in a pack file.  The pack
1780         * is probably already open and will be faster to obtain
1781         * the data through than the working directory.  Loose
1782         * objects however would tend to be slower as they need
1783         * to be individually opened and inflated.
1784         */
1785        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
1786                return 0;
1787
1788        len = strlen(name);
1789        pos = cache_name_pos(name, len);
1790        if (pos < 0)
1791                return 0;
1792        ce = active_cache[pos];
1793
1794        /*
1795         * This is not the sha1 we are looking for, or
1796         * unreusable because it is not a regular file.
1797         */
1798        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1799                return 0;
1800
1801        /*
1802         * If ce is marked as "assume unchanged", there is no
1803         * guarantee that work tree matches what we are looking for.
1804         */
1805        if (ce->ce_flags & CE_VALID)
1806                return 0;
1807
1808        /*
1809         * If ce matches the file in the work tree, we can reuse it.
1810         */
1811        if (ce_uptodate(ce) ||
1812            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1813                return 1;
1814
1815        return 0;
1816}
1817
1818static int populate_from_stdin(struct diff_filespec *s)
1819{
1820        struct strbuf buf = STRBUF_INIT;
1821        size_t size = 0;
1822
1823        if (strbuf_read(&buf, 0, 0) < 0)
1824                return error("error while reading from stdin %s",
1825                                     strerror(errno));
1826
1827        s->should_munmap = 0;
1828        s->data = strbuf_detach(&buf, &size);
1829        s->size = size;
1830        s->should_free = 1;
1831        return 0;
1832}
1833
1834static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1835{
1836        int len;
1837        char *data = xmalloc(100);
1838        len = snprintf(data, 100,
1839                "Subproject commit %s\n", sha1_to_hex(s->sha1));
1840        s->data = data;
1841        s->size = len;
1842        s->should_free = 1;
1843        if (size_only) {
1844                s->data = NULL;
1845                free(data);
1846        }
1847        return 0;
1848}
1849
1850/*
1851 * While doing rename detection and pickaxe operation, we may need to
1852 * grab the data for the blob (or file) for our own in-core comparison.
1853 * diff_filespec has data and size fields for this purpose.
1854 */
1855int diff_populate_filespec(struct diff_filespec *s, int size_only)
1856{
1857        int err = 0;
1858        if (!DIFF_FILE_VALID(s))
1859                die("internal error: asking to populate invalid file.");
1860        if (S_ISDIR(s->mode))
1861                return -1;
1862
1863        if (s->data)
1864                return 0;
1865
1866        if (size_only && 0 < s->size)
1867                return 0;
1868
1869        if (S_ISGITLINK(s->mode))
1870                return diff_populate_gitlink(s, size_only);
1871
1872        if (!s->sha1_valid ||
1873            reuse_worktree_file(s->path, s->sha1, 0)) {
1874                struct strbuf buf = STRBUF_INIT;
1875                struct stat st;
1876                int fd;
1877
1878                if (!strcmp(s->path, "-"))
1879                        return populate_from_stdin(s);
1880
1881                if (lstat(s->path, &st) < 0) {
1882                        if (errno == ENOENT) {
1883                        err_empty:
1884                                err = -1;
1885                        empty:
1886                                s->data = (char *)"";
1887                                s->size = 0;
1888                                return err;
1889                        }
1890                }
1891                s->size = xsize_t(st.st_size);
1892                if (!s->size)
1893                        goto empty;
1894                if (S_ISLNK(st.st_mode)) {
1895                        struct strbuf sb = STRBUF_INIT;
1896
1897                        if (strbuf_readlink(&sb, s->path, s->size))
1898                                goto err_empty;
1899                        s->size = sb.len;
1900                        s->data = strbuf_detach(&sb, NULL);
1901                        s->should_free = 1;
1902                        return 0;
1903                }
1904                if (size_only)
1905                        return 0;
1906                fd = open(s->path, O_RDONLY);
1907                if (fd < 0)
1908                        goto err_empty;
1909                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1910                close(fd);
1911                s->should_munmap = 1;
1912
1913                /*
1914                 * Convert from working tree format to canonical git format
1915                 */
1916                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1917                        size_t size = 0;
1918                        munmap(s->data, s->size);
1919                        s->should_munmap = 0;
1920                        s->data = strbuf_detach(&buf, &size);
1921                        s->size = size;
1922                        s->should_free = 1;
1923                }
1924        }
1925        else {
1926                enum object_type type;
1927                if (size_only)
1928                        type = sha1_object_info(s->sha1, &s->size);
1929                else {
1930                        s->data = read_sha1_file(s->sha1, &type, &s->size);
1931                        s->should_free = 1;
1932                }
1933        }
1934        return 0;
1935}
1936
1937void diff_free_filespec_blob(struct diff_filespec *s)
1938{
1939        if (s->should_free)
1940                free(s->data);
1941        else if (s->should_munmap)
1942                munmap(s->data, s->size);
1943
1944        if (s->should_free || s->should_munmap) {
1945                s->should_free = s->should_munmap = 0;
1946                s->data = NULL;
1947        }
1948}
1949
1950void diff_free_filespec_data(struct diff_filespec *s)
1951{
1952        diff_free_filespec_blob(s);
1953        free(s->cnt_data);
1954        s->cnt_data = NULL;
1955}
1956
1957static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
1958                           void *blob,
1959                           unsigned long size,
1960                           const unsigned char *sha1,
1961                           int mode)
1962{
1963        int fd;
1964        struct strbuf buf = STRBUF_INIT;
1965
1966        fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1967        if (fd < 0)
1968                die("unable to create temp-file: %s", strerror(errno));
1969        if (convert_to_working_tree(path,
1970                        (const char *)blob, (size_t)size, &buf)) {
1971                blob = buf.buf;
1972                size = buf.len;
1973        }
1974        if (write_in_full(fd, blob, size) != size)
1975                die("unable to write temp-file");
1976        close(fd);
1977        temp->name = temp->tmp_path;
1978        strcpy(temp->hex, sha1_to_hex(sha1));
1979        temp->hex[40] = 0;
1980        sprintf(temp->mode, "%06o", mode);
1981        strbuf_release(&buf);
1982}
1983
1984static struct diff_tempfile *prepare_temp_file(const char *name,
1985                struct diff_filespec *one)
1986{
1987        struct diff_tempfile *temp = claim_diff_tempfile();
1988
1989        if (!DIFF_FILE_VALID(one)) {
1990        not_a_valid_file:
1991                /* A '-' entry produces this for file-2, and
1992                 * a '+' entry produces this for file-1.
1993                 */
1994                temp->name = "/dev/null";
1995                strcpy(temp->hex, ".");
1996                strcpy(temp->mode, ".");
1997                return temp;
1998        }
1999
2000        if (!remove_tempfile_installed) {
2001                atexit(remove_tempfile);
2002                sigchain_push_common(remove_tempfile_on_signal);
2003                remove_tempfile_installed = 1;
2004        }
2005
2006        if (!one->sha1_valid ||
2007            reuse_worktree_file(name, one->sha1, 1)) {
2008                struct stat st;
2009                if (lstat(name, &st) < 0) {
2010                        if (errno == ENOENT)
2011                                goto not_a_valid_file;
2012                        die("stat(%s): %s", name, strerror(errno));
2013                }
2014                if (S_ISLNK(st.st_mode)) {
2015                        int ret;
2016                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
2017                        ret = readlink(name, buf, sizeof(buf));
2018                        if (ret < 0)
2019                                die("readlink(%s)", name);
2020                        if (ret == sizeof(buf))
2021                                die("symlink too long: %s", name);
2022                        prep_temp_blob(name, temp, buf, ret,
2023                                       (one->sha1_valid ?
2024                                        one->sha1 : null_sha1),
2025                                       (one->sha1_valid ?
2026                                        one->mode : S_IFLNK));
2027                }
2028                else {
2029                        /* we can borrow from the file in the work tree */
2030                        temp->name = name;
2031                        if (!one->sha1_valid)
2032                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2033                        else
2034                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2035                        /* Even though we may sometimes borrow the
2036                         * contents from the work tree, we always want
2037                         * one->mode.  mode is trustworthy even when
2038                         * !(one->sha1_valid), as long as
2039                         * DIFF_FILE_VALID(one).
2040                         */
2041                        sprintf(temp->mode, "%06o", one->mode);
2042                }
2043                return temp;
2044        }
2045        else {
2046                if (diff_populate_filespec(one, 0))
2047                        die("cannot read data blob for %s", one->path);
2048                prep_temp_blob(name, temp, one->data, one->size,
2049                               one->sha1, one->mode);
2050        }
2051        return temp;
2052}
2053
2054/* An external diff command takes:
2055 *
2056 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2057 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2058 *
2059 */
2060static void run_external_diff(const char *pgm,
2061                              const char *name,
2062                              const char *other,
2063                              struct diff_filespec *one,
2064                              struct diff_filespec *two,
2065                              const char *xfrm_msg,
2066                              int complete_rewrite)
2067{
2068        const char *spawn_arg[10];
2069        int retval;
2070        const char **arg = &spawn_arg[0];
2071
2072        if (one && two) {
2073                struct diff_tempfile *temp_one, *temp_two;
2074                const char *othername = (other ? other : name);
2075                temp_one = prepare_temp_file(name, one);
2076                temp_two = prepare_temp_file(othername, two);
2077                *arg++ = pgm;
2078                *arg++ = name;
2079                *arg++ = temp_one->name;
2080                *arg++ = temp_one->hex;
2081                *arg++ = temp_one->mode;
2082                *arg++ = temp_two->name;
2083                *arg++ = temp_two->hex;
2084                *arg++ = temp_two->mode;
2085                if (other) {
2086                        *arg++ = other;
2087                        *arg++ = xfrm_msg;
2088                }
2089        } else {
2090                *arg++ = pgm;
2091                *arg++ = name;
2092        }
2093        *arg = NULL;
2094        fflush(NULL);
2095        retval = run_command_v_opt(spawn_arg, 0);
2096        remove_tempfile();
2097        if (retval) {
2098                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2099                exit(1);
2100        }
2101}
2102
2103static int similarity_index(struct diff_filepair *p)
2104{
2105        return p->score * 100 / MAX_SCORE;
2106}
2107
2108static void fill_metainfo(struct strbuf *msg,
2109                          const char *name,
2110                          const char *other,
2111                          struct diff_filespec *one,
2112                          struct diff_filespec *two,
2113                          struct diff_options *o,
2114                          struct diff_filepair *p)
2115{
2116        strbuf_init(msg, PATH_MAX * 2 + 300);
2117        switch (p->status) {
2118        case DIFF_STATUS_COPIED:
2119                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2120                strbuf_addstr(msg, "\ncopy from ");
2121                quote_c_style(name, msg, NULL, 0);
2122                strbuf_addstr(msg, "\ncopy to ");
2123                quote_c_style(other, msg, NULL, 0);
2124                strbuf_addch(msg, '\n');
2125                break;
2126        case DIFF_STATUS_RENAMED:
2127                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2128                strbuf_addstr(msg, "\nrename from ");
2129                quote_c_style(name, msg, NULL, 0);
2130                strbuf_addstr(msg, "\nrename to ");
2131                quote_c_style(other, msg, NULL, 0);
2132                strbuf_addch(msg, '\n');
2133                break;
2134        case DIFF_STATUS_MODIFIED:
2135                if (p->score) {
2136                        strbuf_addf(msg, "dissimilarity index %d%%\n",
2137                                    similarity_index(p));
2138                        break;
2139                }
2140                /* fallthru */
2141        default:
2142                /* nothing */
2143                ;
2144        }
2145        if (one && two && hashcmp(one->sha1, two->sha1)) {
2146                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2147
2148                if (DIFF_OPT_TST(o, BINARY)) {
2149                        mmfile_t mf;
2150                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2151                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2152                                abbrev = 40;
2153                }
2154                strbuf_addf(msg, "index %.*s..%.*s",
2155                            abbrev, sha1_to_hex(one->sha1),
2156                            abbrev, sha1_to_hex(two->sha1));
2157                if (one->mode == two->mode)
2158                        strbuf_addf(msg, " %06o", one->mode);
2159                strbuf_addch(msg, '\n');
2160        }
2161        if (msg->len)
2162                strbuf_setlen(msg, msg->len - 1);
2163}
2164
2165static void run_diff_cmd(const char *pgm,
2166                         const char *name,
2167                         const char *other,
2168                         const char *attr_path,
2169                         struct diff_filespec *one,
2170                         struct diff_filespec *two,
2171                         struct strbuf *msg,
2172                         struct diff_options *o,
2173                         struct diff_filepair *p)
2174{
2175        const char *xfrm_msg = NULL;
2176        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2177
2178        if (msg) {
2179                fill_metainfo(msg, name, other, one, two, o, p);
2180                xfrm_msg = msg->len ? msg->buf : NULL;
2181        }
2182
2183        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2184                pgm = NULL;
2185        else {
2186                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2187                if (drv && drv->external)
2188                        pgm = drv->external;
2189        }
2190
2191        if (pgm) {
2192                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2193                                  complete_rewrite);
2194                return;
2195        }
2196        if (one && two)
2197                builtin_diff(name, other ? other : name,
2198                             one, two, xfrm_msg, o, complete_rewrite);
2199        else
2200                fprintf(o->file, "* Unmerged path %s\n", name);
2201}
2202
2203static void diff_fill_sha1_info(struct diff_filespec *one)
2204{
2205        if (DIFF_FILE_VALID(one)) {
2206                if (!one->sha1_valid) {
2207                        struct stat st;
2208                        if (!strcmp(one->path, "-")) {
2209                                hashcpy(one->sha1, null_sha1);
2210                                return;
2211                        }
2212                        if (lstat(one->path, &st) < 0)
2213                                die("stat %s", one->path);
2214                        if (index_path(one->sha1, one->path, &st, 0))
2215                                die("cannot hash %s", one->path);
2216                }
2217        }
2218        else
2219                hashclr(one->sha1);
2220}
2221
2222static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2223{
2224        /* Strip the prefix but do not molest /dev/null and absolute paths */
2225        if (*namep && **namep != '/')
2226                *namep += prefix_length;
2227        if (*otherp && **otherp != '/')
2228                *otherp += prefix_length;
2229}
2230
2231static void run_diff(struct diff_filepair *p, struct diff_options *o)
2232{
2233        const char *pgm = external_diff();
2234        struct strbuf msg;
2235        struct diff_filespec *one = p->one;
2236        struct diff_filespec *two = p->two;
2237        const char *name;
2238        const char *other;
2239        const char *attr_path;
2240
2241        name  = p->one->path;
2242        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2243        attr_path = name;
2244        if (o->prefix_length)
2245                strip_prefix(o->prefix_length, &name, &other);
2246
2247        if (DIFF_PAIR_UNMERGED(p)) {
2248                run_diff_cmd(pgm, name, NULL, attr_path,
2249                             NULL, NULL, NULL, o, p);
2250                return;
2251        }
2252
2253        diff_fill_sha1_info(one);
2254        diff_fill_sha1_info(two);
2255
2256        if (!pgm &&
2257            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2258            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2259                /*
2260                 * a filepair that changes between file and symlink
2261                 * needs to be split into deletion and creation.
2262                 */
2263                struct diff_filespec *null = alloc_filespec(two->path);
2264                run_diff_cmd(NULL, name, other, attr_path,
2265                             one, null, &msg, o, p);
2266                free(null);
2267                strbuf_release(&msg);
2268
2269                null = alloc_filespec(one->path);
2270                run_diff_cmd(NULL, name, other, attr_path,
2271                             null, two, &msg, o, p);
2272                free(null);
2273        }
2274        else
2275                run_diff_cmd(pgm, name, other, attr_path,
2276                             one, two, &msg, o, p);
2277
2278        strbuf_release(&msg);
2279}
2280
2281static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2282                         struct diffstat_t *diffstat)
2283{
2284        const char *name;
2285        const char *other;
2286        int complete_rewrite = 0;
2287
2288        if (DIFF_PAIR_UNMERGED(p)) {
2289                /* unmerged */
2290                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2291                return;
2292        }
2293
2294        name = p->one->path;
2295        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2296
2297        if (o->prefix_length)
2298                strip_prefix(o->prefix_length, &name, &other);
2299
2300        diff_fill_sha1_info(p->one);
2301        diff_fill_sha1_info(p->two);
2302
2303        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2304                complete_rewrite = 1;
2305        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2306}
2307
2308static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2309{
2310        const char *name;
2311        const char *other;
2312        const char *attr_path;
2313
2314        if (DIFF_PAIR_UNMERGED(p)) {
2315                /* unmerged */
2316                return;
2317        }
2318
2319        name = p->one->path;
2320        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2321        attr_path = other ? other : name;
2322
2323        if (o->prefix_length)
2324                strip_prefix(o->prefix_length, &name, &other);
2325
2326        diff_fill_sha1_info(p->one);
2327        diff_fill_sha1_info(p->two);
2328
2329        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2330}
2331
2332void diff_setup(struct diff_options *options)
2333{
2334        memset(options, 0, sizeof(*options));
2335
2336        options->file = stdout;
2337
2338        options->line_termination = '\n';
2339        options->break_opt = -1;
2340        options->rename_limit = -1;
2341        options->dirstat_percent = 3;
2342        options->context = 3;
2343
2344        options->change = diff_change;
2345        options->add_remove = diff_addremove;
2346        if (diff_use_color_default > 0)
2347                DIFF_OPT_SET(options, COLOR_DIFF);
2348        options->detect_rename = diff_detect_rename_default;
2349
2350        if (!diff_mnemonic_prefix) {
2351                options->a_prefix = "a/";
2352                options->b_prefix = "b/";
2353        }
2354}
2355
2356int diff_setup_done(struct diff_options *options)
2357{
2358        int count = 0;
2359
2360        if (options->output_format & DIFF_FORMAT_NAME)
2361                count++;
2362        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2363                count++;
2364        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2365                count++;
2366        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2367                count++;
2368        if (count > 1)
2369                die("--name-only, --name-status, --check and -s are mutually exclusive");
2370
2371        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2372                options->detect_rename = DIFF_DETECT_COPY;
2373
2374        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2375                options->prefix = NULL;
2376        if (options->prefix)
2377                options->prefix_length = strlen(options->prefix);
2378        else
2379                options->prefix_length = 0;
2380
2381        if (options->output_format & (DIFF_FORMAT_NAME |
2382                                      DIFF_FORMAT_NAME_STATUS |
2383                                      DIFF_FORMAT_CHECKDIFF |
2384                                      DIFF_FORMAT_NO_OUTPUT))
2385                options->output_format &= ~(DIFF_FORMAT_RAW |
2386                                            DIFF_FORMAT_NUMSTAT |
2387                                            DIFF_FORMAT_DIFFSTAT |
2388                                            DIFF_FORMAT_SHORTSTAT |
2389                                            DIFF_FORMAT_DIRSTAT |
2390                                            DIFF_FORMAT_SUMMARY |
2391                                            DIFF_FORMAT_PATCH);
2392
2393        /*
2394         * These cases always need recursive; we do not drop caller-supplied
2395         * recursive bits for other formats here.
2396         */
2397        if (options->output_format & (DIFF_FORMAT_PATCH |
2398                                      DIFF_FORMAT_NUMSTAT |
2399                                      DIFF_FORMAT_DIFFSTAT |
2400                                      DIFF_FORMAT_SHORTSTAT |
2401                                      DIFF_FORMAT_DIRSTAT |
2402                                      DIFF_FORMAT_SUMMARY |
2403                                      DIFF_FORMAT_CHECKDIFF))
2404                DIFF_OPT_SET(options, RECURSIVE);
2405        /*
2406         * Also pickaxe would not work very well if you do not say recursive
2407         */
2408        if (options->pickaxe)
2409                DIFF_OPT_SET(options, RECURSIVE);
2410
2411        if (options->detect_rename && options->rename_limit < 0)
2412                options->rename_limit = diff_rename_limit_default;
2413        if (options->setup & DIFF_SETUP_USE_CACHE) {
2414                if (!active_cache)
2415                        /* read-cache does not die even when it fails
2416                         * so it is safe for us to do this here.  Also
2417                         * it does not smudge active_cache or active_nr
2418                         * when it fails, so we do not have to worry about
2419                         * cleaning it up ourselves either.
2420                         */
2421                        read_cache();
2422        }
2423        if (options->abbrev <= 0 || 40 < options->abbrev)
2424                options->abbrev = 40; /* full */
2425
2426        /*
2427         * It does not make sense to show the first hit we happened
2428         * to have found.  It does not make sense not to return with
2429         * exit code in such a case either.
2430         */
2431        if (DIFF_OPT_TST(options, QUIET)) {
2432                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2433                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2434        }
2435
2436        return 0;
2437}
2438
2439static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2440{
2441        char c, *eq;
2442        int len;
2443
2444        if (*arg != '-')
2445                return 0;
2446        c = *++arg;
2447        if (!c)
2448                return 0;
2449        if (c == arg_short) {
2450                c = *++arg;
2451                if (!c)
2452                        return 1;
2453                if (val && isdigit(c)) {
2454                        char *end;
2455                        int n = strtoul(arg, &end, 10);
2456                        if (*end)
2457                                return 0;
2458                        *val = n;
2459                        return 1;
2460                }
2461                return 0;
2462        }
2463        if (c != '-')
2464                return 0;
2465        arg++;
2466        eq = strchr(arg, '=');
2467        if (eq)
2468                len = eq - arg;
2469        else
2470                len = strlen(arg);
2471        if (!len || strncmp(arg, arg_long, len))
2472                return 0;
2473        if (eq) {
2474                int n;
2475                char *end;
2476                if (!isdigit(*++eq))
2477                        return 0;
2478                n = strtoul(eq, &end, 10);
2479                if (*end)
2480                        return 0;
2481                *val = n;
2482        }
2483        return 1;
2484}
2485
2486static int diff_scoreopt_parse(const char *opt);
2487
2488int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2489{
2490        const char *arg = av[0];
2491
2492        /* Output format options */
2493        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2494                options->output_format |= DIFF_FORMAT_PATCH;
2495        else if (opt_arg(arg, 'U', "unified", &options->context))
2496                options->output_format |= DIFF_FORMAT_PATCH;
2497        else if (!strcmp(arg, "--raw"))
2498                options->output_format |= DIFF_FORMAT_RAW;
2499        else if (!strcmp(arg, "--patch-with-raw"))
2500                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2501        else if (!strcmp(arg, "--numstat"))
2502                options->output_format |= DIFF_FORMAT_NUMSTAT;
2503        else if (!strcmp(arg, "--shortstat"))
2504                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2505        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2506                options->output_format |= DIFF_FORMAT_DIRSTAT;
2507        else if (!strcmp(arg, "--cumulative")) {
2508                options->output_format |= DIFF_FORMAT_DIRSTAT;
2509                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2510        } else if (opt_arg(arg, 0, "dirstat-by-file",
2511                           &options->dirstat_percent)) {
2512                options->output_format |= DIFF_FORMAT_DIRSTAT;
2513                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2514        }
2515        else if (!strcmp(arg, "--check"))
2516                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2517        else if (!strcmp(arg, "--summary"))
2518                options->output_format |= DIFF_FORMAT_SUMMARY;
2519        else if (!strcmp(arg, "--patch-with-stat"))
2520                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2521        else if (!strcmp(arg, "--name-only"))
2522                options->output_format |= DIFF_FORMAT_NAME;
2523        else if (!strcmp(arg, "--name-status"))
2524                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2525        else if (!strcmp(arg, "-s"))
2526                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2527        else if (!prefixcmp(arg, "--stat")) {
2528                char *end;
2529                int width = options->stat_width;
2530                int name_width = options->stat_name_width;
2531                arg += 6;
2532                end = (char *)arg;
2533
2534                switch (*arg) {
2535                case '-':
2536                        if (!prefixcmp(arg, "-width="))
2537                                width = strtoul(arg + 7, &end, 10);
2538                        else if (!prefixcmp(arg, "-name-width="))
2539                                name_width = strtoul(arg + 12, &end, 10);
2540                        break;
2541                case '=':
2542                        width = strtoul(arg+1, &end, 10);
2543                        if (*end == ',')
2544                                name_width = strtoul(end+1, &end, 10);
2545                }
2546
2547                /* Important! This checks all the error cases! */
2548                if (*end)
2549                        return 0;
2550                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2551                options->stat_name_width = name_width;
2552                options->stat_width = width;
2553        }
2554
2555        /* renames options */
2556        else if (!prefixcmp(arg, "-B")) {
2557                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2558                        return -1;
2559        }
2560        else if (!prefixcmp(arg, "-M")) {
2561                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2562                        return -1;
2563                options->detect_rename = DIFF_DETECT_RENAME;
2564        }
2565        else if (!prefixcmp(arg, "-C")) {
2566                if (options->detect_rename == DIFF_DETECT_COPY)
2567                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2568                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2569                        return -1;
2570                options->detect_rename = DIFF_DETECT_COPY;
2571        }
2572        else if (!strcmp(arg, "--no-renames"))
2573                options->detect_rename = 0;
2574        else if (!strcmp(arg, "--relative"))
2575                DIFF_OPT_SET(options, RELATIVE_NAME);
2576        else if (!prefixcmp(arg, "--relative=")) {
2577                DIFF_OPT_SET(options, RELATIVE_NAME);
2578                options->prefix = arg + 11;
2579        }
2580
2581        /* xdiff options */
2582        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2583                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2584        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2585                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2586        else if (!strcmp(arg, "--ignore-space-at-eol"))
2587                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2588        else if (!strcmp(arg, "--patience"))
2589                DIFF_XDL_SET(options, PATIENCE_DIFF);
2590
2591        /* flags options */
2592        else if (!strcmp(arg, "--binary")) {
2593                options->output_format |= DIFF_FORMAT_PATCH;
2594                DIFF_OPT_SET(options, BINARY);
2595        }
2596        else if (!strcmp(arg, "--full-index"))
2597                DIFF_OPT_SET(options, FULL_INDEX);
2598        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2599                DIFF_OPT_SET(options, TEXT);
2600        else if (!strcmp(arg, "-R"))
2601                DIFF_OPT_SET(options, REVERSE_DIFF);
2602        else if (!strcmp(arg, "--find-copies-harder"))
2603                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2604        else if (!strcmp(arg, "--follow"))
2605                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2606        else if (!strcmp(arg, "--color"))
2607                DIFF_OPT_SET(options, COLOR_DIFF);
2608        else if (!strcmp(arg, "--no-color"))
2609                DIFF_OPT_CLR(options, COLOR_DIFF);
2610        else if (!strcmp(arg, "--color-words")) {
2611                DIFF_OPT_SET(options, COLOR_DIFF);
2612                DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2613        }
2614        else if (!prefixcmp(arg, "--color-words=")) {
2615                DIFF_OPT_SET(options, COLOR_DIFF);
2616                DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2617                options->word_regex = arg + 14;
2618        }
2619        else if (!strcmp(arg, "--exit-code"))
2620                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2621        else if (!strcmp(arg, "--quiet"))
2622                DIFF_OPT_SET(options, QUIET);
2623        else if (!strcmp(arg, "--ext-diff"))
2624                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2625        else if (!strcmp(arg, "--no-ext-diff"))
2626                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2627        else if (!strcmp(arg, "--textconv"))
2628                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2629        else if (!strcmp(arg, "--no-textconv"))
2630                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2631        else if (!strcmp(arg, "--ignore-submodules"))
2632                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2633
2634        /* misc options */
2635        else if (!strcmp(arg, "-z"))
2636                options->line_termination = 0;
2637        else if (!prefixcmp(arg, "-l"))
2638                options->rename_limit = strtoul(arg+2, NULL, 10);
2639        else if (!prefixcmp(arg, "-S"))
2640                options->pickaxe = arg + 2;
2641        else if (!strcmp(arg, "--pickaxe-all"))
2642                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2643        else if (!strcmp(arg, "--pickaxe-regex"))
2644                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2645        else if (!prefixcmp(arg, "-O"))
2646                options->orderfile = arg + 2;
2647        else if (!prefixcmp(arg, "--diff-filter="))
2648                options->filter = arg + 14;
2649        else if (!strcmp(arg, "--abbrev"))
2650                options->abbrev = DEFAULT_ABBREV;
2651        else if (!prefixcmp(arg, "--abbrev=")) {
2652                options->abbrev = strtoul(arg + 9, NULL, 10);
2653                if (options->abbrev < MINIMUM_ABBREV)
2654                        options->abbrev = MINIMUM_ABBREV;
2655                else if (40 < options->abbrev)
2656                        options->abbrev = 40;
2657        }
2658        else if (!prefixcmp(arg, "--src-prefix="))
2659                options->a_prefix = arg + 13;
2660        else if (!prefixcmp(arg, "--dst-prefix="))
2661                options->b_prefix = arg + 13;
2662        else if (!strcmp(arg, "--no-prefix"))
2663                options->a_prefix = options->b_prefix = "";
2664        else if (opt_arg(arg, '\0', "inter-hunk-context",
2665                         &options->interhunkcontext))
2666                ;
2667        else if (!prefixcmp(arg, "--output=")) {
2668                options->file = fopen(arg + strlen("--output="), "w");
2669                options->close_file = 1;
2670        } else
2671                return 0;
2672        return 1;
2673}
2674
2675static int parse_num(const char **cp_p)
2676{
2677        unsigned long num, scale;
2678        int ch, dot;
2679        const char *cp = *cp_p;
2680
2681        num = 0;
2682        scale = 1;
2683        dot = 0;
2684        for(;;) {
2685                ch = *cp;
2686                if ( !dot && ch == '.' ) {
2687                        scale = 1;
2688                        dot = 1;
2689                } else if ( ch == '%' ) {
2690                        scale = dot ? scale*100 : 100;
2691                        cp++;   /* % is always at the end */
2692                        break;
2693                } else if ( ch >= '0' && ch <= '9' ) {
2694                        if ( scale < 100000 ) {
2695                                scale *= 10;
2696                                num = (num*10) + (ch-'0');
2697                        }
2698                } else {
2699                        break;
2700                }
2701                cp++;
2702        }
2703        *cp_p = cp;
2704
2705        /* user says num divided by scale and we say internally that
2706         * is MAX_SCORE * num / scale.
2707         */
2708        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2709}
2710
2711static int diff_scoreopt_parse(const char *opt)
2712{
2713        int opt1, opt2, cmd;
2714
2715        if (*opt++ != '-')
2716                return -1;
2717        cmd = *opt++;
2718        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2719                return -1; /* that is not a -M, -C nor -B option */
2720
2721        opt1 = parse_num(&opt);
2722        if (cmd != 'B')
2723                opt2 = 0;
2724        else {
2725                if (*opt == 0)
2726                        opt2 = 0;
2727                else if (*opt != '/')
2728                        return -1; /* we expect -B80/99 or -B80 */
2729                else {
2730                        opt++;
2731                        opt2 = parse_num(&opt);
2732                }
2733        }
2734        if (*opt != 0)
2735                return -1;
2736        return opt1 | (opt2 << 16);
2737}
2738
2739struct diff_queue_struct diff_queued_diff;
2740
2741void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2742{
2743        if (queue->alloc <= queue->nr) {
2744                queue->alloc = alloc_nr(queue->alloc);
2745                queue->queue = xrealloc(queue->queue,
2746                                        sizeof(dp) * queue->alloc);
2747        }
2748        queue->queue[queue->nr++] = dp;
2749}
2750
2751struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2752                                 struct diff_filespec *one,
2753                                 struct diff_filespec *two)
2754{
2755        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2756        dp->one = one;
2757        dp->two = two;
2758        if (queue)
2759                diff_q(queue, dp);
2760        return dp;
2761}
2762
2763void diff_free_filepair(struct diff_filepair *p)
2764{
2765        free_filespec(p->one);
2766        free_filespec(p->two);
2767        free(p);
2768}
2769
2770/* This is different from find_unique_abbrev() in that
2771 * it stuffs the result with dots for alignment.
2772 */
2773const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2774{
2775        int abblen;
2776        const char *abbrev;
2777        if (len == 40)
2778                return sha1_to_hex(sha1);
2779
2780        abbrev = find_unique_abbrev(sha1, len);
2781        abblen = strlen(abbrev);
2782        if (abblen < 37) {
2783                static char hex[41];
2784                if (len < abblen && abblen <= len + 2)
2785                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2786                else
2787                        sprintf(hex, "%s...", abbrev);
2788                return hex;
2789        }
2790        return sha1_to_hex(sha1);
2791}
2792
2793static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2794{
2795        int line_termination = opt->line_termination;
2796        int inter_name_termination = line_termination ? '\t' : '\0';
2797
2798        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2799                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2800                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
2801                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2802        }
2803        if (p->score) {
2804                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2805                        inter_name_termination);
2806        } else {
2807                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2808        }
2809
2810        if (p->status == DIFF_STATUS_COPIED ||
2811            p->status == DIFF_STATUS_RENAMED) {
2812                const char *name_a, *name_b;
2813                name_a = p->one->path;
2814                name_b = p->two->path;
2815                strip_prefix(opt->prefix_length, &name_a, &name_b);
2816                write_name_quoted(name_a, opt->file, inter_name_termination);
2817                write_name_quoted(name_b, opt->file, line_termination);
2818        } else {
2819                const char *name_a, *name_b;
2820                name_a = p->one->mode ? p->one->path : p->two->path;
2821                name_b = NULL;
2822                strip_prefix(opt->prefix_length, &name_a, &name_b);
2823                write_name_quoted(name_a, opt->file, line_termination);
2824        }
2825}
2826
2827int diff_unmodified_pair(struct diff_filepair *p)
2828{
2829        /* This function is written stricter than necessary to support
2830         * the currently implemented transformers, but the idea is to
2831         * let transformers to produce diff_filepairs any way they want,
2832         * and filter and clean them up here before producing the output.
2833         */
2834        struct diff_filespec *one = p->one, *two = p->two;
2835
2836        if (DIFF_PAIR_UNMERGED(p))
2837                return 0; /* unmerged is interesting */
2838
2839        /* deletion, addition, mode or type change
2840         * and rename are all interesting.
2841         */
2842        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2843            DIFF_PAIR_MODE_CHANGED(p) ||
2844            strcmp(one->path, two->path))
2845                return 0;
2846
2847        /* both are valid and point at the same path.  that is, we are
2848         * dealing with a change.
2849         */
2850        if (one->sha1_valid && two->sha1_valid &&
2851            !hashcmp(one->sha1, two->sha1))
2852                return 1; /* no change */
2853        if (!one->sha1_valid && !two->sha1_valid)
2854                return 1; /* both look at the same file on the filesystem. */
2855        return 0;
2856}
2857
2858static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2859{
2860        if (diff_unmodified_pair(p))
2861                return;
2862
2863        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2864            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2865                return; /* no tree diffs in patch format */
2866
2867        run_diff(p, o);
2868}
2869
2870static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2871                            struct diffstat_t *diffstat)
2872{
2873        if (diff_unmodified_pair(p))
2874                return;
2875
2876        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2877            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2878                return; /* no tree diffs in patch format */
2879
2880        run_diffstat(p, o, diffstat);
2881}
2882
2883static void diff_flush_checkdiff(struct diff_filepair *p,
2884                struct diff_options *o)
2885{
2886        if (diff_unmodified_pair(p))
2887                return;
2888
2889        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2890            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2891                return; /* no tree diffs in patch format */
2892
2893        run_checkdiff(p, o);
2894}
2895
2896int diff_queue_is_empty(void)
2897{
2898        struct diff_queue_struct *q = &diff_queued_diff;
2899        int i;
2900        for (i = 0; i < q->nr; i++)
2901                if (!diff_unmodified_pair(q->queue[i]))
2902                        return 0;
2903        return 1;
2904}
2905
2906#if DIFF_DEBUG
2907void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2908{
2909        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2910                x, one ? one : "",
2911                s->path,
2912                DIFF_FILE_VALID(s) ? "valid" : "invalid",
2913                s->mode,
2914                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2915        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2916                x, one ? one : "",
2917                s->size, s->xfrm_flags);
2918}
2919
2920void diff_debug_filepair(const struct diff_filepair *p, int i)
2921{
2922        diff_debug_filespec(p->one, i, "one");
2923        diff_debug_filespec(p->two, i, "two");
2924        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2925                p->score, p->status ? p->status : '?',
2926                p->one->rename_used, p->broken_pair);
2927}
2928
2929void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2930{
2931        int i;
2932        if (msg)
2933                fprintf(stderr, "%s\n", msg);
2934        fprintf(stderr, "q->nr = %d\n", q->nr);
2935        for (i = 0; i < q->nr; i++) {
2936                struct diff_filepair *p = q->queue[i];
2937                diff_debug_filepair(p, i);
2938        }
2939}
2940#endif
2941
2942static void diff_resolve_rename_copy(void)
2943{
2944        int i;
2945        struct diff_filepair *p;
2946        struct diff_queue_struct *q = &diff_queued_diff;
2947
2948        diff_debug_queue("resolve-rename-copy", q);
2949
2950        for (i = 0; i < q->nr; i++) {
2951                p = q->queue[i];
2952                p->status = 0; /* undecided */
2953                if (DIFF_PAIR_UNMERGED(p))
2954                        p->status = DIFF_STATUS_UNMERGED;
2955                else if (!DIFF_FILE_VALID(p->one))
2956                        p->status = DIFF_STATUS_ADDED;
2957                else if (!DIFF_FILE_VALID(p->two))
2958                        p->status = DIFF_STATUS_DELETED;
2959                else if (DIFF_PAIR_TYPE_CHANGED(p))
2960                        p->status = DIFF_STATUS_TYPE_CHANGED;
2961
2962                /* from this point on, we are dealing with a pair
2963                 * whose both sides are valid and of the same type, i.e.
2964                 * either in-place edit or rename/copy edit.
2965                 */
2966                else if (DIFF_PAIR_RENAME(p)) {
2967                        /*
2968                         * A rename might have re-connected a broken
2969                         * pair up, causing the pathnames to be the
2970                         * same again. If so, that's not a rename at
2971                         * all, just a modification..
2972                         *
2973                         * Otherwise, see if this source was used for
2974                         * multiple renames, in which case we decrement
2975                         * the count, and call it a copy.
2976                         */
2977                        if (!strcmp(p->one->path, p->two->path))
2978                                p->status = DIFF_STATUS_MODIFIED;
2979                        else if (--p->one->rename_used > 0)
2980                                p->status = DIFF_STATUS_COPIED;
2981                        else
2982                                p->status = DIFF_STATUS_RENAMED;
2983                }
2984                else if (hashcmp(p->one->sha1, p->two->sha1) ||
2985                         p->one->mode != p->two->mode ||
2986                         is_null_sha1(p->one->sha1))
2987                        p->status = DIFF_STATUS_MODIFIED;
2988                else {
2989                        /* This is a "no-change" entry and should not
2990                         * happen anymore, but prepare for broken callers.
2991                         */
2992                        error("feeding unmodified %s to diffcore",
2993                              p->one->path);
2994                        p->status = DIFF_STATUS_UNKNOWN;
2995                }
2996        }
2997        diff_debug_queue("resolve-rename-copy done", q);
2998}
2999
3000static int check_pair_status(struct diff_filepair *p)
3001{
3002        switch (p->status) {
3003        case DIFF_STATUS_UNKNOWN:
3004                return 0;
3005        case 0:
3006                die("internal error in diff-resolve-rename-copy");
3007        default:
3008                return 1;
3009        }
3010}
3011
3012static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3013{
3014        int fmt = opt->output_format;
3015
3016        if (fmt & DIFF_FORMAT_CHECKDIFF)
3017                diff_flush_checkdiff(p, opt);
3018        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3019                diff_flush_raw(p, opt);
3020        else if (fmt & DIFF_FORMAT_NAME) {
3021                const char *name_a, *name_b;
3022                name_a = p->two->path;
3023                name_b = NULL;
3024                strip_prefix(opt->prefix_length, &name_a, &name_b);
3025                write_name_quoted(name_a, opt->file, opt->line_termination);
3026        }
3027}
3028
3029static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3030{
3031        if (fs->mode)
3032                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3033        else
3034                fprintf(file, " %s ", newdelete);
3035        write_name_quoted(fs->path, file, '\n');
3036}
3037
3038
3039static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3040{
3041        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3042                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3043                        show_name ? ' ' : '\n');
3044                if (show_name) {
3045                        write_name_quoted(p->two->path, file, '\n');
3046                }
3047        }
3048}
3049
3050static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3051{
3052        char *names = pprint_rename(p->one->path, p->two->path);
3053
3054        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3055        free(names);
3056        show_mode_change(file, p, 0);
3057}
3058
3059static void diff_summary(FILE *file, struct diff_filepair *p)
3060{
3061        switch(p->status) {
3062        case DIFF_STATUS_DELETED:
3063                show_file_mode_name(file, "delete", p->one);
3064                break;
3065        case DIFF_STATUS_ADDED:
3066                show_file_mode_name(file, "create", p->two);
3067                break;
3068        case DIFF_STATUS_COPIED:
3069                show_rename_copy(file, "copy", p);
3070                break;
3071        case DIFF_STATUS_RENAMED:
3072                show_rename_copy(file, "rename", p);
3073                break;
3074        default:
3075                if (p->score) {
3076                        fputs(" rewrite ", file);
3077                        write_name_quoted(p->two->path, file, ' ');
3078                        fprintf(file, "(%d%%)\n", similarity_index(p));
3079                }
3080                show_mode_change(file, p, !p->score);
3081                break;
3082        }
3083}
3084
3085struct patch_id_t {
3086        git_SHA_CTX *ctx;
3087        int patchlen;
3088};
3089
3090static int remove_space(char *line, int len)
3091{
3092        int i;
3093        char *dst = line;
3094        unsigned char c;
3095
3096        for (i = 0; i < len; i++)
3097                if (!isspace((c = line[i])))
3098                        *dst++ = c;
3099
3100        return dst - line;
3101}
3102
3103static void patch_id_consume(void *priv, char *line, unsigned long len)
3104{
3105        struct patch_id_t *data = priv;
3106        int new_len;
3107
3108        /* Ignore line numbers when computing the SHA1 of the patch */
3109        if (!prefixcmp(line, "@@ -"))
3110                return;
3111
3112        new_len = remove_space(line, len);
3113
3114        git_SHA1_Update(data->ctx, line, new_len);
3115        data->patchlen += new_len;
3116}
3117
3118/* returns 0 upon success, and writes result into sha1 */
3119static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3120{
3121        struct diff_queue_struct *q = &diff_queued_diff;
3122        int i;
3123        git_SHA_CTX ctx;
3124        struct patch_id_t data;
3125        char buffer[PATH_MAX * 4 + 20];
3126
3127        git_SHA1_Init(&ctx);
3128        memset(&data, 0, sizeof(struct patch_id_t));
3129        data.ctx = &ctx;
3130
3131        for (i = 0; i < q->nr; i++) {
3132                xpparam_t xpp;
3133                xdemitconf_t xecfg;
3134                xdemitcb_t ecb;
3135                mmfile_t mf1, mf2;
3136                struct diff_filepair *p = q->queue[i];
3137                int len1, len2;
3138
3139                memset(&xpp, 0, sizeof(xpp));
3140                memset(&xecfg, 0, sizeof(xecfg));
3141                if (p->status == 0)
3142                        return error("internal diff status error");
3143                if (p->status == DIFF_STATUS_UNKNOWN)
3144                        continue;
3145                if (diff_unmodified_pair(p))
3146                        continue;
3147                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3148                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3149                        continue;
3150                if (DIFF_PAIR_UNMERGED(p))
3151                        continue;
3152
3153                diff_fill_sha1_info(p->one);
3154                diff_fill_sha1_info(p->two);
3155                if (fill_mmfile(&mf1, p->one) < 0 ||
3156                                fill_mmfile(&mf2, p->two) < 0)
3157                        return error("unable to read files to diff");
3158
3159                len1 = remove_space(p->one->path, strlen(p->one->path));
3160                len2 = remove_space(p->two->path, strlen(p->two->path));
3161                if (p->one->mode == 0)
3162                        len1 = snprintf(buffer, sizeof(buffer),
3163                                        "diff--gita/%.*sb/%.*s"
3164                                        "newfilemode%06o"
3165                                        "---/dev/null"
3166                                        "+++b/%.*s",
3167                                        len1, p->one->path,
3168                                        len2, p->two->path,
3169                                        p->two->mode,
3170                                        len2, p->two->path);
3171                else if (p->two->mode == 0)
3172                        len1 = snprintf(buffer, sizeof(buffer),
3173                                        "diff--gita/%.*sb/%.*s"
3174                                        "deletedfilemode%06o"
3175                                        "---a/%.*s"
3176                                        "+++/dev/null",
3177                                        len1, p->one->path,
3178                                        len2, p->two->path,
3179                                        p->one->mode,
3180                                        len1, p->one->path);
3181                else
3182                        len1 = snprintf(buffer, sizeof(buffer),
3183                                        "diff--gita/%.*sb/%.*s"
3184                                        "---a/%.*s"
3185                                        "+++b/%.*s",
3186                                        len1, p->one->path,
3187                                        len2, p->two->path,
3188                                        len1, p->one->path,
3189                                        len2, p->two->path);
3190                git_SHA1_Update(&ctx, buffer, len1);
3191
3192                xpp.flags = XDF_NEED_MINIMAL;
3193                xecfg.ctxlen = 3;
3194                xecfg.flags = XDL_EMIT_FUNCNAMES;
3195                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3196                              &xpp, &xecfg, &ecb);
3197        }
3198
3199        git_SHA1_Final(sha1, &ctx);
3200        return 0;
3201}
3202
3203int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3204{
3205        struct diff_queue_struct *q = &diff_queued_diff;
3206        int i;
3207        int result = diff_get_patch_id(options, sha1);
3208
3209        for (i = 0; i < q->nr; i++)
3210                diff_free_filepair(q->queue[i]);
3211
3212        free(q->queue);
3213        q->queue = NULL;
3214        q->nr = q->alloc = 0;
3215
3216        return result;
3217}
3218
3219static int is_summary_empty(const struct diff_queue_struct *q)
3220{
3221        int i;
3222
3223        for (i = 0; i < q->nr; i++) {
3224                const struct diff_filepair *p = q->queue[i];
3225
3226                switch (p->status) {
3227                case DIFF_STATUS_DELETED:
3228                case DIFF_STATUS_ADDED:
3229                case DIFF_STATUS_COPIED:
3230                case DIFF_STATUS_RENAMED:
3231                        return 0;
3232                default:
3233                        if (p->score)
3234                                return 0;
3235                        if (p->one->mode && p->two->mode &&
3236                            p->one->mode != p->two->mode)
3237                                return 0;
3238                        break;
3239                }
3240        }
3241        return 1;
3242}
3243
3244void diff_flush(struct diff_options *options)
3245{
3246        struct diff_queue_struct *q = &diff_queued_diff;
3247        int i, output_format = options->output_format;
3248        int separator = 0;
3249
3250        /*
3251         * Order: raw, stat, summary, patch
3252         * or:    name/name-status/checkdiff (other bits clear)
3253         */
3254        if (!q->nr)
3255                goto free_queue;
3256
3257        if (output_format & (DIFF_FORMAT_RAW |
3258                             DIFF_FORMAT_NAME |
3259                             DIFF_FORMAT_NAME_STATUS |
3260                             DIFF_FORMAT_CHECKDIFF)) {
3261                for (i = 0; i < q->nr; i++) {
3262                        struct diff_filepair *p = q->queue[i];
3263                        if (check_pair_status(p))
3264                                flush_one_pair(p, options);
3265                }
3266                separator++;
3267        }
3268
3269        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3270                struct diffstat_t diffstat;
3271
3272                memset(&diffstat, 0, sizeof(struct diffstat_t));
3273                for (i = 0; i < q->nr; i++) {
3274                        struct diff_filepair *p = q->queue[i];
3275                        if (check_pair_status(p))
3276                                diff_flush_stat(p, options, &diffstat);
3277                }
3278                if (output_format & DIFF_FORMAT_NUMSTAT)
3279                        show_numstat(&diffstat, options);
3280                if (output_format & DIFF_FORMAT_DIFFSTAT)
3281                        show_stats(&diffstat, options);
3282                if (output_format & DIFF_FORMAT_SHORTSTAT)
3283                        show_shortstats(&diffstat, options);
3284                free_diffstat_info(&diffstat);
3285                separator++;
3286        }
3287        if (output_format & DIFF_FORMAT_DIRSTAT)
3288                show_dirstat(options);
3289
3290        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3291                for (i = 0; i < q->nr; i++)
3292                        diff_summary(options->file, q->queue[i]);
3293                separator++;
3294        }
3295
3296        if (output_format & DIFF_FORMAT_PATCH) {
3297                if (separator) {
3298                        putc(options->line_termination, options->file);
3299                        if (options->stat_sep) {
3300                                /* attach patch instead of inline */
3301                                fputs(options->stat_sep, options->file);
3302                        }
3303                }
3304
3305                for (i = 0; i < q->nr; i++) {
3306                        struct diff_filepair *p = q->queue[i];
3307                        if (check_pair_status(p))
3308                                diff_flush_patch(p, options);
3309                }
3310        }
3311
3312        if (output_format & DIFF_FORMAT_CALLBACK)
3313                options->format_callback(q, options, options->format_callback_data);
3314
3315        for (i = 0; i < q->nr; i++)
3316                diff_free_filepair(q->queue[i]);
3317free_queue:
3318        free(q->queue);
3319        q->queue = NULL;
3320        q->nr = q->alloc = 0;
3321        if (options->close_file)
3322                fclose(options->file);
3323}
3324
3325static void diffcore_apply_filter(const char *filter)
3326{
3327        int i;
3328        struct diff_queue_struct *q = &diff_queued_diff;
3329        struct diff_queue_struct outq;
3330        outq.queue = NULL;
3331        outq.nr = outq.alloc = 0;
3332
3333        if (!filter)
3334                return;
3335
3336        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3337                int found;
3338                for (i = found = 0; !found && i < q->nr; i++) {
3339                        struct diff_filepair *p = q->queue[i];
3340                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3341                             ((p->score &&
3342                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3343                              (!p->score &&
3344                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3345                            ((p->status != DIFF_STATUS_MODIFIED) &&
3346                             strchr(filter, p->status)))
3347                                found++;
3348                }
3349                if (found)
3350                        return;
3351
3352                /* otherwise we will clear the whole queue
3353                 * by copying the empty outq at the end of this
3354                 * function, but first clear the current entries
3355                 * in the queue.
3356                 */
3357                for (i = 0; i < q->nr; i++)
3358                        diff_free_filepair(q->queue[i]);
3359        }
3360        else {
3361                /* Only the matching ones */
3362                for (i = 0; i < q->nr; i++) {
3363                        struct diff_filepair *p = q->queue[i];
3364
3365                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3366                             ((p->score &&
3367                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3368                              (!p->score &&
3369                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3370                            ((p->status != DIFF_STATUS_MODIFIED) &&
3371                             strchr(filter, p->status)))
3372                                diff_q(&outq, p);
3373                        else
3374                                diff_free_filepair(p);
3375                }
3376        }
3377        free(q->queue);
3378        *q = outq;
3379}
3380
3381/* Check whether two filespecs with the same mode and size are identical */
3382static int diff_filespec_is_identical(struct diff_filespec *one,
3383                                      struct diff_filespec *two)
3384{
3385        if (S_ISGITLINK(one->mode))
3386                return 0;
3387        if (diff_populate_filespec(one, 0))
3388                return 0;
3389        if (diff_populate_filespec(two, 0))
3390                return 0;
3391        return !memcmp(one->data, two->data, one->size);
3392}
3393
3394static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3395{
3396        int i;
3397        struct diff_queue_struct *q = &diff_queued_diff;
3398        struct diff_queue_struct outq;
3399        outq.queue = NULL;
3400        outq.nr = outq.alloc = 0;
3401
3402        for (i = 0; i < q->nr; i++) {
3403                struct diff_filepair *p = q->queue[i];
3404
3405                /*
3406                 * 1. Entries that come from stat info dirtyness
3407                 *    always have both sides (iow, not create/delete),
3408                 *    one side of the object name is unknown, with
3409                 *    the same mode and size.  Keep the ones that
3410                 *    do not match these criteria.  They have real
3411                 *    differences.
3412                 *
3413                 * 2. At this point, the file is known to be modified,
3414                 *    with the same mode and size, and the object
3415                 *    name of one side is unknown.  Need to inspect
3416                 *    the identical contents.
3417                 */
3418                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3419                    !DIFF_FILE_VALID(p->two) ||
3420                    (p->one->sha1_valid && p->two->sha1_valid) ||
3421                    (p->one->mode != p->two->mode) ||
3422                    diff_populate_filespec(p->one, 1) ||
3423                    diff_populate_filespec(p->two, 1) ||
3424                    (p->one->size != p->two->size) ||
3425                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3426                        diff_q(&outq, p);
3427                else {
3428                        /*
3429                         * The caller can subtract 1 from skip_stat_unmatch
3430                         * to determine how many paths were dirty only
3431                         * due to stat info mismatch.
3432                         */
3433                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3434                                diffopt->skip_stat_unmatch++;
3435                        diff_free_filepair(p);
3436                }
3437        }
3438        free(q->queue);
3439        *q = outq;
3440}
3441
3442void diffcore_std(struct diff_options *options)
3443{
3444        if (options->skip_stat_unmatch)
3445                diffcore_skip_stat_unmatch(options);
3446        if (options->break_opt != -1)
3447                diffcore_break(options->break_opt);
3448        if (options->detect_rename)
3449                diffcore_rename(options);
3450        if (options->break_opt != -1)
3451                diffcore_merge_broken();
3452        if (options->pickaxe)
3453                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3454        if (options->orderfile)
3455                diffcore_order(options->orderfile);
3456        diff_resolve_rename_copy();
3457        diffcore_apply_filter(options->filter);
3458
3459        if (diff_queued_diff.nr)
3460                DIFF_OPT_SET(options, HAS_CHANGES);
3461        else
3462                DIFF_OPT_CLR(options, HAS_CHANGES);
3463}
3464
3465int diff_result_code(struct diff_options *opt, int status)
3466{
3467        int result = 0;
3468        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3469            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3470                return status;
3471        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3472            DIFF_OPT_TST(opt, HAS_CHANGES))
3473                result |= 01;
3474        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3475            DIFF_OPT_TST(opt, CHECK_FAILED))
3476                result |= 02;
3477        return result;
3478}
3479
3480void diff_addremove(struct diff_options *options,
3481                    int addremove, unsigned mode,
3482                    const unsigned char *sha1,
3483                    const char *concatpath)
3484{
3485        struct diff_filespec *one, *two;
3486
3487        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3488                return;
3489
3490        /* This may look odd, but it is a preparation for
3491         * feeding "there are unchanged files which should
3492         * not produce diffs, but when you are doing copy
3493         * detection you would need them, so here they are"
3494         * entries to the diff-core.  They will be prefixed
3495         * with something like '=' or '*' (I haven't decided
3496         * which but should not make any difference).
3497         * Feeding the same new and old to diff_change()
3498         * also has the same effect.
3499         * Before the final output happens, they are pruned after
3500         * merged into rename/copy pairs as appropriate.
3501         */
3502        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3503                addremove = (addremove == '+' ? '-' :
3504                             addremove == '-' ? '+' : addremove);
3505
3506        if (options->prefix &&
3507            strncmp(concatpath, options->prefix, options->prefix_length))
3508                return;
3509
3510        one = alloc_filespec(concatpath);
3511        two = alloc_filespec(concatpath);
3512
3513        if (addremove != '+')
3514                fill_filespec(one, sha1, mode);
3515        if (addremove != '-')
3516                fill_filespec(two, sha1, mode);
3517
3518        diff_queue(&diff_queued_diff, one, two);
3519        DIFF_OPT_SET(options, HAS_CHANGES);
3520}
3521
3522void diff_change(struct diff_options *options,
3523                 unsigned old_mode, unsigned new_mode,
3524                 const unsigned char *old_sha1,
3525                 const unsigned char *new_sha1,
3526                 const char *concatpath)
3527{
3528        struct diff_filespec *one, *two;
3529
3530        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3531                        && S_ISGITLINK(new_mode))
3532                return;
3533
3534        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3535                unsigned tmp;
3536                const unsigned char *tmp_c;
3537                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3538                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3539        }
3540
3541        if (options->prefix &&
3542            strncmp(concatpath, options->prefix, options->prefix_length))
3543                return;
3544
3545        one = alloc_filespec(concatpath);
3546        two = alloc_filespec(concatpath);
3547        fill_filespec(one, old_sha1, old_mode);
3548        fill_filespec(two, new_sha1, new_mode);
3549
3550        diff_queue(&diff_queued_diff, one, two);
3551        DIFF_OPT_SET(options, HAS_CHANGES);
3552}
3553
3554void diff_unmerge(struct diff_options *options,
3555                  const char *path,
3556                  unsigned mode, const unsigned char *sha1)
3557{
3558        struct diff_filespec *one, *two;
3559
3560        if (options->prefix &&
3561            strncmp(path, options->prefix, options->prefix_length))
3562                return;
3563
3564        one = alloc_filespec(path);
3565        two = alloc_filespec(path);
3566        fill_filespec(one, sha1, mode);
3567        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3568}
3569
3570static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3571                size_t *outsize)
3572{
3573        struct diff_tempfile *temp;
3574        const char *argv[3];
3575        const char **arg = argv;
3576        struct child_process child;
3577        struct strbuf buf = STRBUF_INIT;
3578
3579        temp = prepare_temp_file(spec->path, spec);
3580        *arg++ = pgm;
3581        *arg++ = temp->name;
3582        *arg = NULL;
3583
3584        memset(&child, 0, sizeof(child));
3585        child.argv = argv;
3586        child.out = -1;
3587        if (start_command(&child) != 0 ||
3588            strbuf_read(&buf, child.out, 0) < 0 ||
3589            finish_command(&child) != 0) {
3590                remove_tempfile();
3591                error("error running textconv command '%s'", pgm);
3592                return NULL;
3593        }
3594        remove_tempfile();
3595
3596        return strbuf_detach(&buf, outsize);
3597}