diff.con commit Merge branch 'maint-1.6.1' into maint-1.6.2 (34ab57d)
   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        "\033[m",       /* reset */
  34        "",             /* PLAIN (normal) */
  35        "\033[1m",      /* METAINFO (bold) */
  36        "\033[36m",     /* FRAGINFO (cyan) */
  37        "\033[31m",     /* OLD (red) */
  38        "\033[32m",     /* NEW (green) */
  39        "\033[33m",     /* COMMIT (yellow) */
  40        "\033[41m",     /* WHITESPACE (red background) */
  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, total, 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                total = add + del;
 982                adds += add;
 983                dels += del;
 984
 985                if (width <= max_change) {
 986                        add = scale_linear(add, width, max_change);
 987                        del = scale_linear(del, width, max_change);
 988                        total = add + del;
 989                }
 990                show_name(options->file, prefix, name, len, reset, set);
 991                fprintf(options->file, "%5d%s", added + deleted,
 992                                added + deleted ? " " : "");
 993                show_graph(options->file, '+', add, add_c, reset);
 994                show_graph(options->file, '-', del, del_c, reset);
 995                fprintf(options->file, "\n");
 996        }
 997        fprintf(options->file,
 998               "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
 999               set, total_files, adds, dels, reset);
1000}
1001
1002static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
1003{
1004        int i, adds = 0, dels = 0, total_files = data->nr;
1005
1006        if (data->nr == 0)
1007                return;
1008
1009        for (i = 0; i < data->nr; i++) {
1010                if (!data->files[i]->is_binary &&
1011                    !data->files[i]->is_unmerged) {
1012                        int added = data->files[i]->added;
1013                        int deleted= data->files[i]->deleted;
1014                        if (!data->files[i]->is_renamed &&
1015                            (added + deleted == 0)) {
1016                                total_files--;
1017                        } else {
1018                                adds += added;
1019                                dels += deleted;
1020                        }
1021                }
1022        }
1023        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1024               total_files, adds, dels);
1025}
1026
1027static void show_numstat(struct diffstat_t* data, struct diff_options *options)
1028{
1029        int i;
1030
1031        if (data->nr == 0)
1032                return;
1033
1034        for (i = 0; i < data->nr; i++) {
1035                struct diffstat_file *file = data->files[i];
1036
1037                if (file->is_binary)
1038                        fprintf(options->file, "-\t-\t");
1039                else
1040                        fprintf(options->file,
1041                                "%d\t%d\t", file->added, file->deleted);
1042                if (options->line_termination) {
1043                        fill_print_name(file);
1044                        if (!file->is_renamed)
1045                                write_name_quoted(file->name, options->file,
1046                                                  options->line_termination);
1047                        else {
1048                                fputs(file->print_name, options->file);
1049                                putc(options->line_termination, options->file);
1050                        }
1051                } else {
1052                        if (file->is_renamed) {
1053                                putc('\0', options->file);
1054                                write_name_quoted(file->from_name, options->file, '\0');
1055                        }
1056                        write_name_quoted(file->name, options->file, '\0');
1057                }
1058        }
1059}
1060
1061struct dirstat_file {
1062        const char *name;
1063        unsigned long changed;
1064};
1065
1066struct dirstat_dir {
1067        struct dirstat_file *files;
1068        int alloc, nr, percent, cumulative;
1069};
1070
1071static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1072{
1073        unsigned long this_dir = 0;
1074        unsigned int sources = 0;
1075
1076        while (dir->nr) {
1077                struct dirstat_file *f = dir->files;
1078                int namelen = strlen(f->name);
1079                unsigned long this;
1080                char *slash;
1081
1082                if (namelen < baselen)
1083                        break;
1084                if (memcmp(f->name, base, baselen))
1085                        break;
1086                slash = strchr(f->name + baselen, '/');
1087                if (slash) {
1088                        int newbaselen = slash + 1 - f->name;
1089                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1090                        sources++;
1091                } else {
1092                        this = f->changed;
1093                        dir->files++;
1094                        dir->nr--;
1095                        sources += 2;
1096                }
1097                this_dir += this;
1098        }
1099
1100        /*
1101         * We don't report dirstat's for
1102         *  - the top level
1103         *  - or cases where everything came from a single directory
1104         *    under this directory (sources == 1).
1105         */
1106        if (baselen && sources != 1) {
1107                int permille = this_dir * 1000 / changed;
1108                if (permille) {
1109                        int percent = permille / 10;
1110                        if (percent >= dir->percent) {
1111                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1112                                if (!dir->cumulative)
1113                                        return 0;
1114                        }
1115                }
1116        }
1117        return this_dir;
1118}
1119
1120static int dirstat_compare(const void *_a, const void *_b)
1121{
1122        const struct dirstat_file *a = _a;
1123        const struct dirstat_file *b = _b;
1124        return strcmp(a->name, b->name);
1125}
1126
1127static void show_dirstat(struct diff_options *options)
1128{
1129        int i;
1130        unsigned long changed;
1131        struct dirstat_dir dir;
1132        struct diff_queue_struct *q = &diff_queued_diff;
1133
1134        dir.files = NULL;
1135        dir.alloc = 0;
1136        dir.nr = 0;
1137        dir.percent = options->dirstat_percent;
1138        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1139
1140        changed = 0;
1141        for (i = 0; i < q->nr; i++) {
1142                struct diff_filepair *p = q->queue[i];
1143                const char *name;
1144                unsigned long copied, added, damage;
1145
1146                name = p->one->path ? p->one->path : p->two->path;
1147
1148                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1149                        diff_populate_filespec(p->one, 0);
1150                        diff_populate_filespec(p->two, 0);
1151                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1152                                               &copied, &added);
1153                        diff_free_filespec_data(p->one);
1154                        diff_free_filespec_data(p->two);
1155                } else if (DIFF_FILE_VALID(p->one)) {
1156                        diff_populate_filespec(p->one, 1);
1157                        copied = added = 0;
1158                        diff_free_filespec_data(p->one);
1159                } else if (DIFF_FILE_VALID(p->two)) {
1160                        diff_populate_filespec(p->two, 1);
1161                        copied = 0;
1162                        added = p->two->size;
1163                        diff_free_filespec_data(p->two);
1164                } else
1165                        continue;
1166
1167                /*
1168                 * Original minus copied is the removed material,
1169                 * added is the new material.  They are both damages
1170                 * made to the preimage. In --dirstat-by-file mode, count
1171                 * damaged files, not damaged lines. This is done by
1172                 * counting only a single damaged line per file.
1173                 */
1174                damage = (p->one->size - copied) + added;
1175                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1176                        damage = 1;
1177
1178                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1179                dir.files[dir.nr].name = name;
1180                dir.files[dir.nr].changed = damage;
1181                changed += damage;
1182                dir.nr++;
1183        }
1184
1185        /* This can happen even with many files, if everything was renames */
1186        if (!changed)
1187                return;
1188
1189        /* Show all directories with more than x% of the changes */
1190        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1191        gather_dirstat(options->file, &dir, changed, "", 0);
1192}
1193
1194static void free_diffstat_info(struct diffstat_t *diffstat)
1195{
1196        int i;
1197        for (i = 0; i < diffstat->nr; i++) {
1198                struct diffstat_file *f = diffstat->files[i];
1199                if (f->name != f->print_name)
1200                        free(f->print_name);
1201                free(f->name);
1202                free(f->from_name);
1203                free(f);
1204        }
1205        free(diffstat->files);
1206}
1207
1208struct checkdiff_t {
1209        const char *filename;
1210        int lineno;
1211        struct diff_options *o;
1212        unsigned ws_rule;
1213        unsigned status;
1214        int trailing_blanks_start;
1215};
1216
1217static int is_conflict_marker(const char *line, unsigned long len)
1218{
1219        char firstchar;
1220        int cnt;
1221
1222        if (len < 8)
1223                return 0;
1224        firstchar = line[0];
1225        switch (firstchar) {
1226        case '=': case '>': case '<':
1227                break;
1228        default:
1229                return 0;
1230        }
1231        for (cnt = 1; cnt < 7; cnt++)
1232                if (line[cnt] != firstchar)
1233                        return 0;
1234        /* line[0] thru line[6] are same as firstchar */
1235        if (firstchar == '=') {
1236                /* divider between ours and theirs? */
1237                if (len != 8 || line[7] != '\n')
1238                        return 0;
1239        } else if (len < 8 || !isspace(line[7])) {
1240                /* not divider before ours nor after theirs */
1241                return 0;
1242        }
1243        return 1;
1244}
1245
1246static void checkdiff_consume(void *priv, char *line, unsigned long len)
1247{
1248        struct checkdiff_t *data = priv;
1249        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1250        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1251        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1252        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1253        char *err;
1254
1255        if (line[0] == '+') {
1256                unsigned bad;
1257                data->lineno++;
1258                if (!ws_blank_line(line + 1, len - 1, data->ws_rule))
1259                        data->trailing_blanks_start = 0;
1260                else if (!data->trailing_blanks_start)
1261                        data->trailing_blanks_start = data->lineno;
1262                if (is_conflict_marker(line + 1, len - 1)) {
1263                        data->status |= 1;
1264                        fprintf(data->o->file,
1265                                "%s:%d: leftover conflict marker\n",
1266                                data->filename, data->lineno);
1267                }
1268                bad = ws_check(line + 1, len - 1, data->ws_rule);
1269                if (!bad)
1270                        return;
1271                data->status |= bad;
1272                err = whitespace_error_string(bad);
1273                fprintf(data->o->file, "%s:%d: %s.\n",
1274                        data->filename, data->lineno, err);
1275                free(err);
1276                emit_line(data->o->file, set, reset, line, 1);
1277                ws_check_emit(line + 1, len - 1, data->ws_rule,
1278                              data->o->file, set, reset, ws);
1279        } else if (line[0] == ' ') {
1280                data->lineno++;
1281                data->trailing_blanks_start = 0;
1282        } else if (line[0] == '@') {
1283                char *plus = strchr(line, '+');
1284                if (plus)
1285                        data->lineno = strtol(plus, NULL, 10) - 1;
1286                else
1287                        die("invalid diff");
1288                data->trailing_blanks_start = 0;
1289        }
1290}
1291
1292static unsigned char *deflate_it(char *data,
1293                                 unsigned long size,
1294                                 unsigned long *result_size)
1295{
1296        int bound;
1297        unsigned char *deflated;
1298        z_stream stream;
1299
1300        memset(&stream, 0, sizeof(stream));
1301        deflateInit(&stream, zlib_compression_level);
1302        bound = deflateBound(&stream, size);
1303        deflated = xmalloc(bound);
1304        stream.next_out = deflated;
1305        stream.avail_out = bound;
1306
1307        stream.next_in = (unsigned char *)data;
1308        stream.avail_in = size;
1309        while (deflate(&stream, Z_FINISH) == Z_OK)
1310                ; /* nothing */
1311        deflateEnd(&stream);
1312        *result_size = stream.total_out;
1313        return deflated;
1314}
1315
1316static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1317{
1318        void *cp;
1319        void *delta;
1320        void *deflated;
1321        void *data;
1322        unsigned long orig_size;
1323        unsigned long delta_size;
1324        unsigned long deflate_size;
1325        unsigned long data_size;
1326
1327        /* We could do deflated delta, or we could do just deflated two,
1328         * whichever is smaller.
1329         */
1330        delta = NULL;
1331        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1332        if (one->size && two->size) {
1333                delta = diff_delta(one->ptr, one->size,
1334                                   two->ptr, two->size,
1335                                   &delta_size, deflate_size);
1336                if (delta) {
1337                        void *to_free = delta;
1338                        orig_size = delta_size;
1339                        delta = deflate_it(delta, delta_size, &delta_size);
1340                        free(to_free);
1341                }
1342        }
1343
1344        if (delta && delta_size < deflate_size) {
1345                fprintf(file, "delta %lu\n", orig_size);
1346                free(deflated);
1347                data = delta;
1348                data_size = delta_size;
1349        }
1350        else {
1351                fprintf(file, "literal %lu\n", two->size);
1352                free(delta);
1353                data = deflated;
1354                data_size = deflate_size;
1355        }
1356
1357        /* emit data encoded in base85 */
1358        cp = data;
1359        while (data_size) {
1360                int bytes = (52 < data_size) ? 52 : data_size;
1361                char line[70];
1362                data_size -= bytes;
1363                if (bytes <= 26)
1364                        line[0] = bytes + 'A' - 1;
1365                else
1366                        line[0] = bytes - 26 + 'a' - 1;
1367                encode_85(line + 1, cp, bytes);
1368                cp = (char *) cp + bytes;
1369                fputs(line, file);
1370                fputc('\n', file);
1371        }
1372        fprintf(file, "\n");
1373        free(data);
1374}
1375
1376static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1377{
1378        fprintf(file, "GIT binary patch\n");
1379        emit_binary_diff_body(file, one, two);
1380        emit_binary_diff_body(file, two, one);
1381}
1382
1383static void diff_filespec_load_driver(struct diff_filespec *one)
1384{
1385        if (!one->driver)
1386                one->driver = userdiff_find_by_path(one->path);
1387        if (!one->driver)
1388                one->driver = userdiff_find_by_name("default");
1389}
1390
1391int diff_filespec_is_binary(struct diff_filespec *one)
1392{
1393        if (one->is_binary == -1) {
1394                diff_filespec_load_driver(one);
1395                if (one->driver->binary != -1)
1396                        one->is_binary = one->driver->binary;
1397                else {
1398                        if (!one->data && DIFF_FILE_VALID(one))
1399                                diff_populate_filespec(one, 0);
1400                        if (one->data)
1401                                one->is_binary = buffer_is_binary(one->data,
1402                                                one->size);
1403                        if (one->is_binary == -1)
1404                                one->is_binary = 0;
1405                }
1406        }
1407        return one->is_binary;
1408}
1409
1410static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1411{
1412        diff_filespec_load_driver(one);
1413        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1414}
1415
1416static const char *userdiff_word_regex(struct diff_filespec *one)
1417{
1418        diff_filespec_load_driver(one);
1419        return one->driver->word_regex;
1420}
1421
1422void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1423{
1424        if (!options->a_prefix)
1425                options->a_prefix = a;
1426        if (!options->b_prefix)
1427                options->b_prefix = b;
1428}
1429
1430static const char *get_textconv(struct diff_filespec *one)
1431{
1432        if (!DIFF_FILE_VALID(one))
1433                return NULL;
1434        if (!S_ISREG(one->mode))
1435                return NULL;
1436        diff_filespec_load_driver(one);
1437        return one->driver->textconv;
1438}
1439
1440static void builtin_diff(const char *name_a,
1441                         const char *name_b,
1442                         struct diff_filespec *one,
1443                         struct diff_filespec *two,
1444                         const char *xfrm_msg,
1445                         struct diff_options *o,
1446                         int complete_rewrite)
1447{
1448        mmfile_t mf1, mf2;
1449        const char *lbl[2];
1450        char *a_one, *b_two;
1451        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1452        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1453        const char *a_prefix, *b_prefix;
1454        const char *textconv_one = NULL, *textconv_two = NULL;
1455
1456        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1457                textconv_one = get_textconv(one);
1458                textconv_two = get_textconv(two);
1459        }
1460
1461        diff_set_mnemonic_prefix(o, "a/", "b/");
1462        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1463                a_prefix = o->b_prefix;
1464                b_prefix = o->a_prefix;
1465        } else {
1466                a_prefix = o->a_prefix;
1467                b_prefix = o->b_prefix;
1468        }
1469
1470        /* Never use a non-valid filename anywhere if at all possible */
1471        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1472        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1473
1474        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1475        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1476        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1477        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1478        fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1479        if (lbl[0][0] == '/') {
1480                /* /dev/null */
1481                fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1482                if (xfrm_msg && xfrm_msg[0])
1483                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1484        }
1485        else if (lbl[1][0] == '/') {
1486                fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1487                if (xfrm_msg && xfrm_msg[0])
1488                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1489        }
1490        else {
1491                if (one->mode != two->mode) {
1492                        fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1493                        fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1494                }
1495                if (xfrm_msg && xfrm_msg[0])
1496                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1497                /*
1498                 * we do not run diff between different kind
1499                 * of objects.
1500                 */
1501                if ((one->mode ^ two->mode) & S_IFMT)
1502                        goto free_ab_and_return;
1503                if (complete_rewrite &&
1504                    (textconv_one || !diff_filespec_is_binary(one)) &&
1505                    (textconv_two || !diff_filespec_is_binary(two))) {
1506                        emit_rewrite_diff(name_a, name_b, one, two,
1507                                                textconv_one, textconv_two, o);
1508                        o->found_changes = 1;
1509                        goto free_ab_and_return;
1510                }
1511        }
1512
1513        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1514                die("unable to read files to diff");
1515
1516        if (!DIFF_OPT_TST(o, TEXT) &&
1517            ( (diff_filespec_is_binary(one) && !textconv_one) ||
1518              (diff_filespec_is_binary(two) && !textconv_two) )) {
1519                /* Quite common confusing case */
1520                if (mf1.size == mf2.size &&
1521                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1522                        goto free_ab_and_return;
1523                if (DIFF_OPT_TST(o, BINARY))
1524                        emit_binary_diff(o->file, &mf1, &mf2);
1525                else
1526                        fprintf(o->file, "Binary files %s and %s differ\n",
1527                                lbl[0], lbl[1]);
1528                o->found_changes = 1;
1529        }
1530        else {
1531                /* Crazy xdl interfaces.. */
1532                const char *diffopts = getenv("GIT_DIFF_OPTS");
1533                xpparam_t xpp;
1534                xdemitconf_t xecfg;
1535                xdemitcb_t ecb;
1536                struct emit_callback ecbdata;
1537                const struct userdiff_funcname *pe;
1538
1539                if (textconv_one) {
1540                        size_t size;
1541                        mf1.ptr = run_textconv(textconv_one, one, &size);
1542                        if (!mf1.ptr)
1543                                die("unable to read files to diff");
1544                        mf1.size = size;
1545                }
1546                if (textconv_two) {
1547                        size_t size;
1548                        mf2.ptr = run_textconv(textconv_two, two, &size);
1549                        if (!mf2.ptr)
1550                                die("unable to read files to diff");
1551                        mf2.size = size;
1552                }
1553
1554                pe = diff_funcname_pattern(one);
1555                if (!pe)
1556                        pe = diff_funcname_pattern(two);
1557
1558                memset(&xpp, 0, sizeof(xpp));
1559                memset(&xecfg, 0, sizeof(xecfg));
1560                memset(&ecbdata, 0, sizeof(ecbdata));
1561                ecbdata.label_path = lbl;
1562                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1563                ecbdata.found_changesp = &o->found_changes;
1564                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1565                ecbdata.file = o->file;
1566                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1567                xecfg.ctxlen = o->context;
1568                xecfg.interhunkctxlen = o->interhunkcontext;
1569                xecfg.flags = XDL_EMIT_FUNCNAMES;
1570                if (pe)
1571                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1572                if (!diffopts)
1573                        ;
1574                else if (!prefixcmp(diffopts, "--unified="))
1575                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1576                else if (!prefixcmp(diffopts, "-u"))
1577                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1578                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1579                        ecbdata.diff_words =
1580                                xcalloc(1, sizeof(struct diff_words_data));
1581                        ecbdata.diff_words->file = o->file;
1582                        if (!o->word_regex)
1583                                o->word_regex = userdiff_word_regex(one);
1584                        if (!o->word_regex)
1585                                o->word_regex = userdiff_word_regex(two);
1586                        if (!o->word_regex)
1587                                o->word_regex = diff_word_regex_cfg;
1588                        if (o->word_regex) {
1589                                ecbdata.diff_words->word_regex = (regex_t *)
1590                                        xmalloc(sizeof(regex_t));
1591                                if (regcomp(ecbdata.diff_words->word_regex,
1592                                                o->word_regex,
1593                                                REG_EXTENDED | REG_NEWLINE))
1594                                        die ("Invalid regular expression: %s",
1595                                                        o->word_regex);
1596                        }
1597                }
1598                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1599                              &xpp, &xecfg, &ecb);
1600                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1601                        free_diff_words_data(&ecbdata);
1602                if (textconv_one)
1603                        free(mf1.ptr);
1604                if (textconv_two)
1605                        free(mf2.ptr);
1606        }
1607
1608 free_ab_and_return:
1609        diff_free_filespec_data(one);
1610        diff_free_filespec_data(two);
1611        free(a_one);
1612        free(b_two);
1613        return;
1614}
1615
1616static void builtin_diffstat(const char *name_a, const char *name_b,
1617                             struct diff_filespec *one,
1618                             struct diff_filespec *two,
1619                             struct diffstat_t *diffstat,
1620                             struct diff_options *o,
1621                             int complete_rewrite)
1622{
1623        mmfile_t mf1, mf2;
1624        struct diffstat_file *data;
1625
1626        data = diffstat_add(diffstat, name_a, name_b);
1627
1628        if (!one || !two) {
1629                data->is_unmerged = 1;
1630                return;
1631        }
1632        if (complete_rewrite) {
1633                diff_populate_filespec(one, 0);
1634                diff_populate_filespec(two, 0);
1635                data->deleted = count_lines(one->data, one->size);
1636                data->added = count_lines(two->data, two->size);
1637                goto free_and_return;
1638        }
1639        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1640                die("unable to read files to diff");
1641
1642        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1643                data->is_binary = 1;
1644                data->added = mf2.size;
1645                data->deleted = mf1.size;
1646        } else {
1647                /* Crazy xdl interfaces.. */
1648                xpparam_t xpp;
1649                xdemitconf_t xecfg;
1650                xdemitcb_t ecb;
1651
1652                memset(&xpp, 0, sizeof(xpp));
1653                memset(&xecfg, 0, sizeof(xecfg));
1654                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1655                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1656                              &xpp, &xecfg, &ecb);
1657        }
1658
1659 free_and_return:
1660        diff_free_filespec_data(one);
1661        diff_free_filespec_data(two);
1662}
1663
1664static void builtin_checkdiff(const char *name_a, const char *name_b,
1665                              const char *attr_path,
1666                              struct diff_filespec *one,
1667                              struct diff_filespec *two,
1668                              struct diff_options *o)
1669{
1670        mmfile_t mf1, mf2;
1671        struct checkdiff_t data;
1672
1673        if (!two)
1674                return;
1675
1676        memset(&data, 0, sizeof(data));
1677        data.filename = name_b ? name_b : name_a;
1678        data.lineno = 0;
1679        data.o = o;
1680        data.ws_rule = whitespace_rule(attr_path);
1681
1682        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1683                die("unable to read files to diff");
1684
1685        /*
1686         * All the other codepaths check both sides, but not checking
1687         * the "old" side here is deliberate.  We are checking the newly
1688         * introduced changes, and as long as the "new" side is text, we
1689         * can and should check what it introduces.
1690         */
1691        if (diff_filespec_is_binary(two))
1692                goto free_and_return;
1693        else {
1694                /* Crazy xdl interfaces.. */
1695                xpparam_t xpp;
1696                xdemitconf_t xecfg;
1697                xdemitcb_t ecb;
1698
1699                memset(&xpp, 0, sizeof(xpp));
1700                memset(&xecfg, 0, sizeof(xecfg));
1701                xecfg.ctxlen = 1; /* at least one context line */
1702                xpp.flags = XDF_NEED_MINIMAL;
1703                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1704                              &xpp, &xecfg, &ecb);
1705
1706                if ((data.ws_rule & WS_TRAILING_SPACE) &&
1707                    data.trailing_blanks_start) {
1708                        fprintf(o->file, "%s:%d: ends with blank lines.\n",
1709                                data.filename, data.trailing_blanks_start);
1710                        data.status = 1; /* report errors */
1711                }
1712        }
1713 free_and_return:
1714        diff_free_filespec_data(one);
1715        diff_free_filespec_data(two);
1716        if (data.status)
1717                DIFF_OPT_SET(o, CHECK_FAILED);
1718}
1719
1720struct diff_filespec *alloc_filespec(const char *path)
1721{
1722        int namelen = strlen(path);
1723        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1724
1725        memset(spec, 0, sizeof(*spec));
1726        spec->path = (char *)(spec + 1);
1727        memcpy(spec->path, path, namelen+1);
1728        spec->count = 1;
1729        spec->is_binary = -1;
1730        return spec;
1731}
1732
1733void free_filespec(struct diff_filespec *spec)
1734{
1735        if (!--spec->count) {
1736                diff_free_filespec_data(spec);
1737                free(spec);
1738        }
1739}
1740
1741void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1742                   unsigned short mode)
1743{
1744        if (mode) {
1745                spec->mode = canon_mode(mode);
1746                hashcpy(spec->sha1, sha1);
1747                spec->sha1_valid = !is_null_sha1(sha1);
1748        }
1749}
1750
1751/*
1752 * Given a name and sha1 pair, if the index tells us the file in
1753 * the work tree has that object contents, return true, so that
1754 * prepare_temp_file() does not have to inflate and extract.
1755 */
1756static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1757{
1758        struct cache_entry *ce;
1759        struct stat st;
1760        int pos, len;
1761
1762        /*
1763         * We do not read the cache ourselves here, because the
1764         * benchmark with my previous version that always reads cache
1765         * shows that it makes things worse for diff-tree comparing
1766         * two linux-2.6 kernel trees in an already checked out work
1767         * tree.  This is because most diff-tree comparisons deal with
1768         * only a small number of files, while reading the cache is
1769         * expensive for a large project, and its cost outweighs the
1770         * savings we get by not inflating the object to a temporary
1771         * file.  Practically, this code only helps when we are used
1772         * by diff-cache --cached, which does read the cache before
1773         * calling us.
1774         */
1775        if (!active_cache)
1776                return 0;
1777
1778        /* We want to avoid the working directory if our caller
1779         * doesn't need the data in a normal file, this system
1780         * is rather slow with its stat/open/mmap/close syscalls,
1781         * and the object is contained in a pack file.  The pack
1782         * is probably already open and will be faster to obtain
1783         * the data through than the working directory.  Loose
1784         * objects however would tend to be slower as they need
1785         * to be individually opened and inflated.
1786         */
1787        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
1788                return 0;
1789
1790        len = strlen(name);
1791        pos = cache_name_pos(name, len);
1792        if (pos < 0)
1793                return 0;
1794        ce = active_cache[pos];
1795
1796        /*
1797         * This is not the sha1 we are looking for, or
1798         * unreusable because it is not a regular file.
1799         */
1800        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1801                return 0;
1802
1803        /*
1804         * If ce is marked as "assume unchanged", there is no
1805         * guarantee that work tree matches what we are looking for.
1806         */
1807        if (ce->ce_flags & CE_VALID)
1808                return 0;
1809
1810        /*
1811         * If ce matches the file in the work tree, we can reuse it.
1812         */
1813        if (ce_uptodate(ce) ||
1814            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1815                return 1;
1816
1817        return 0;
1818}
1819
1820static int populate_from_stdin(struct diff_filespec *s)
1821{
1822        struct strbuf buf = STRBUF_INIT;
1823        size_t size = 0;
1824
1825        if (strbuf_read(&buf, 0, 0) < 0)
1826                return error("error while reading from stdin %s",
1827                                     strerror(errno));
1828
1829        s->should_munmap = 0;
1830        s->data = strbuf_detach(&buf, &size);
1831        s->size = size;
1832        s->should_free = 1;
1833        return 0;
1834}
1835
1836static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1837{
1838        int len;
1839        char *data = xmalloc(100);
1840        len = snprintf(data, 100,
1841                "Subproject commit %s\n", sha1_to_hex(s->sha1));
1842        s->data = data;
1843        s->size = len;
1844        s->should_free = 1;
1845        if (size_only) {
1846                s->data = NULL;
1847                free(data);
1848        }
1849        return 0;
1850}
1851
1852/*
1853 * While doing rename detection and pickaxe operation, we may need to
1854 * grab the data for the blob (or file) for our own in-core comparison.
1855 * diff_filespec has data and size fields for this purpose.
1856 */
1857int diff_populate_filespec(struct diff_filespec *s, int size_only)
1858{
1859        int err = 0;
1860        if (!DIFF_FILE_VALID(s))
1861                die("internal error: asking to populate invalid file.");
1862        if (S_ISDIR(s->mode))
1863                return -1;
1864
1865        if (s->data)
1866                return 0;
1867
1868        if (size_only && 0 < s->size)
1869                return 0;
1870
1871        if (S_ISGITLINK(s->mode))
1872                return diff_populate_gitlink(s, size_only);
1873
1874        if (!s->sha1_valid ||
1875            reuse_worktree_file(s->path, s->sha1, 0)) {
1876                struct strbuf buf = STRBUF_INIT;
1877                struct stat st;
1878                int fd;
1879
1880                if (!strcmp(s->path, "-"))
1881                        return populate_from_stdin(s);
1882
1883                if (lstat(s->path, &st) < 0) {
1884                        if (errno == ENOENT) {
1885                        err_empty:
1886                                err = -1;
1887                        empty:
1888                                s->data = (char *)"";
1889                                s->size = 0;
1890                                return err;
1891                        }
1892                }
1893                s->size = xsize_t(st.st_size);
1894                if (!s->size)
1895                        goto empty;
1896                if (S_ISLNK(st.st_mode)) {
1897                        struct strbuf sb = STRBUF_INIT;
1898
1899                        if (strbuf_readlink(&sb, s->path, s->size))
1900                                goto err_empty;
1901                        s->size = sb.len;
1902                        s->data = strbuf_detach(&sb, NULL);
1903                        s->should_free = 1;
1904                        return 0;
1905                }
1906                if (size_only)
1907                        return 0;
1908                fd = open(s->path, O_RDONLY);
1909                if (fd < 0)
1910                        goto err_empty;
1911                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1912                close(fd);
1913                s->should_munmap = 1;
1914
1915                /*
1916                 * Convert from working tree format to canonical git format
1917                 */
1918                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1919                        size_t size = 0;
1920                        munmap(s->data, s->size);
1921                        s->should_munmap = 0;
1922                        s->data = strbuf_detach(&buf, &size);
1923                        s->size = size;
1924                        s->should_free = 1;
1925                }
1926        }
1927        else {
1928                enum object_type type;
1929                if (size_only)
1930                        type = sha1_object_info(s->sha1, &s->size);
1931                else {
1932                        s->data = read_sha1_file(s->sha1, &type, &s->size);
1933                        s->should_free = 1;
1934                }
1935        }
1936        return 0;
1937}
1938
1939void diff_free_filespec_blob(struct diff_filespec *s)
1940{
1941        if (s->should_free)
1942                free(s->data);
1943        else if (s->should_munmap)
1944                munmap(s->data, s->size);
1945
1946        if (s->should_free || s->should_munmap) {
1947                s->should_free = s->should_munmap = 0;
1948                s->data = NULL;
1949        }
1950}
1951
1952void diff_free_filespec_data(struct diff_filespec *s)
1953{
1954        diff_free_filespec_blob(s);
1955        free(s->cnt_data);
1956        s->cnt_data = NULL;
1957}
1958
1959static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
1960                           void *blob,
1961                           unsigned long size,
1962                           const unsigned char *sha1,
1963                           int mode)
1964{
1965        int fd;
1966        struct strbuf buf = STRBUF_INIT;
1967
1968        fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1969        if (fd < 0)
1970                die("unable to create temp-file: %s", strerror(errno));
1971        if (convert_to_working_tree(path,
1972                        (const char *)blob, (size_t)size, &buf)) {
1973                blob = buf.buf;
1974                size = buf.len;
1975        }
1976        if (write_in_full(fd, blob, size) != size)
1977                die("unable to write temp-file");
1978        close(fd);
1979        temp->name = temp->tmp_path;
1980        strcpy(temp->hex, sha1_to_hex(sha1));
1981        temp->hex[40] = 0;
1982        sprintf(temp->mode, "%06o", mode);
1983        strbuf_release(&buf);
1984}
1985
1986static struct diff_tempfile *prepare_temp_file(const char *name,
1987                struct diff_filespec *one)
1988{
1989        struct diff_tempfile *temp = claim_diff_tempfile();
1990
1991        if (!DIFF_FILE_VALID(one)) {
1992        not_a_valid_file:
1993                /* A '-' entry produces this for file-2, and
1994                 * a '+' entry produces this for file-1.
1995                 */
1996                temp->name = "/dev/null";
1997                strcpy(temp->hex, ".");
1998                strcpy(temp->mode, ".");
1999                return temp;
2000        }
2001
2002        if (!remove_tempfile_installed) {
2003                atexit(remove_tempfile);
2004                sigchain_push_common(remove_tempfile_on_signal);
2005                remove_tempfile_installed = 1;
2006        }
2007
2008        if (!one->sha1_valid ||
2009            reuse_worktree_file(name, one->sha1, 1)) {
2010                struct stat st;
2011                if (lstat(name, &st) < 0) {
2012                        if (errno == ENOENT)
2013                                goto not_a_valid_file;
2014                        die("stat(%s): %s", name, strerror(errno));
2015                }
2016                if (S_ISLNK(st.st_mode)) {
2017                        int ret;
2018                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
2019                        ret = readlink(name, buf, sizeof(buf));
2020                        if (ret < 0)
2021                                die("readlink(%s)", name);
2022                        if (ret == sizeof(buf))
2023                                die("symlink too long: %s", name);
2024                        prep_temp_blob(name, temp, buf, ret,
2025                                       (one->sha1_valid ?
2026                                        one->sha1 : null_sha1),
2027                                       (one->sha1_valid ?
2028                                        one->mode : S_IFLNK));
2029                }
2030                else {
2031                        /* we can borrow from the file in the work tree */
2032                        temp->name = name;
2033                        if (!one->sha1_valid)
2034                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2035                        else
2036                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2037                        /* Even though we may sometimes borrow the
2038                         * contents from the work tree, we always want
2039                         * one->mode.  mode is trustworthy even when
2040                         * !(one->sha1_valid), as long as
2041                         * DIFF_FILE_VALID(one).
2042                         */
2043                        sprintf(temp->mode, "%06o", one->mode);
2044                }
2045                return temp;
2046        }
2047        else {
2048                if (diff_populate_filespec(one, 0))
2049                        die("cannot read data blob for %s", one->path);
2050                prep_temp_blob(name, temp, one->data, one->size,
2051                               one->sha1, one->mode);
2052        }
2053        return temp;
2054}
2055
2056/* An external diff command takes:
2057 *
2058 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2059 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2060 *
2061 */
2062static void run_external_diff(const char *pgm,
2063                              const char *name,
2064                              const char *other,
2065                              struct diff_filespec *one,
2066                              struct diff_filespec *two,
2067                              const char *xfrm_msg,
2068                              int complete_rewrite)
2069{
2070        const char *spawn_arg[10];
2071        int retval;
2072        const char **arg = &spawn_arg[0];
2073
2074        if (one && two) {
2075                struct diff_tempfile *temp_one, *temp_two;
2076                const char *othername = (other ? other : name);
2077                temp_one = prepare_temp_file(name, one);
2078                temp_two = prepare_temp_file(othername, two);
2079                *arg++ = pgm;
2080                *arg++ = name;
2081                *arg++ = temp_one->name;
2082                *arg++ = temp_one->hex;
2083                *arg++ = temp_one->mode;
2084                *arg++ = temp_two->name;
2085                *arg++ = temp_two->hex;
2086                *arg++ = temp_two->mode;
2087                if (other) {
2088                        *arg++ = other;
2089                        *arg++ = xfrm_msg;
2090                }
2091        } else {
2092                *arg++ = pgm;
2093                *arg++ = name;
2094        }
2095        *arg = NULL;
2096        fflush(NULL);
2097        retval = run_command_v_opt(spawn_arg, 0);
2098        remove_tempfile();
2099        if (retval) {
2100                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2101                exit(1);
2102        }
2103}
2104
2105static int similarity_index(struct diff_filepair *p)
2106{
2107        return p->score * 100 / MAX_SCORE;
2108}
2109
2110static void fill_metainfo(struct strbuf *msg,
2111                          const char *name,
2112                          const char *other,
2113                          struct diff_filespec *one,
2114                          struct diff_filespec *two,
2115                          struct diff_options *o,
2116                          struct diff_filepair *p)
2117{
2118        strbuf_init(msg, PATH_MAX * 2 + 300);
2119        switch (p->status) {
2120        case DIFF_STATUS_COPIED:
2121                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2122                strbuf_addstr(msg, "\ncopy from ");
2123                quote_c_style(name, msg, NULL, 0);
2124                strbuf_addstr(msg, "\ncopy to ");
2125                quote_c_style(other, msg, NULL, 0);
2126                strbuf_addch(msg, '\n');
2127                break;
2128        case DIFF_STATUS_RENAMED:
2129                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2130                strbuf_addstr(msg, "\nrename from ");
2131                quote_c_style(name, msg, NULL, 0);
2132                strbuf_addstr(msg, "\nrename to ");
2133                quote_c_style(other, msg, NULL, 0);
2134                strbuf_addch(msg, '\n');
2135                break;
2136        case DIFF_STATUS_MODIFIED:
2137                if (p->score) {
2138                        strbuf_addf(msg, "dissimilarity index %d%%\n",
2139                                    similarity_index(p));
2140                        break;
2141                }
2142                /* fallthru */
2143        default:
2144                /* nothing */
2145                ;
2146        }
2147        if (one && two && hashcmp(one->sha1, two->sha1)) {
2148                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2149
2150                if (DIFF_OPT_TST(o, BINARY)) {
2151                        mmfile_t mf;
2152                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2153                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2154                                abbrev = 40;
2155                }
2156                strbuf_addf(msg, "index %.*s..%.*s",
2157                            abbrev, sha1_to_hex(one->sha1),
2158                            abbrev, sha1_to_hex(two->sha1));
2159                if (one->mode == two->mode)
2160                        strbuf_addf(msg, " %06o", one->mode);
2161                strbuf_addch(msg, '\n');
2162        }
2163        if (msg->len)
2164                strbuf_setlen(msg, msg->len - 1);
2165}
2166
2167static void run_diff_cmd(const char *pgm,
2168                         const char *name,
2169                         const char *other,
2170                         const char *attr_path,
2171                         struct diff_filespec *one,
2172                         struct diff_filespec *two,
2173                         struct strbuf *msg,
2174                         struct diff_options *o,
2175                         struct diff_filepair *p)
2176{
2177        const char *xfrm_msg = NULL;
2178        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2179
2180        if (msg) {
2181                fill_metainfo(msg, name, other, one, two, o, p);
2182                xfrm_msg = msg->len ? msg->buf : NULL;
2183        }
2184
2185        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2186                pgm = NULL;
2187        else {
2188                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2189                if (drv && drv->external)
2190                        pgm = drv->external;
2191        }
2192
2193        if (pgm) {
2194                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2195                                  complete_rewrite);
2196                return;
2197        }
2198        if (one && two)
2199                builtin_diff(name, other ? other : name,
2200                             one, two, xfrm_msg, o, complete_rewrite);
2201        else
2202                fprintf(o->file, "* Unmerged path %s\n", name);
2203}
2204
2205static void diff_fill_sha1_info(struct diff_filespec *one)
2206{
2207        if (DIFF_FILE_VALID(one)) {
2208                if (!one->sha1_valid) {
2209                        struct stat st;
2210                        if (!strcmp(one->path, "-")) {
2211                                hashcpy(one->sha1, null_sha1);
2212                                return;
2213                        }
2214                        if (lstat(one->path, &st) < 0)
2215                                die("stat %s", one->path);
2216                        if (index_path(one->sha1, one->path, &st, 0))
2217                                die("cannot hash %s", one->path);
2218                }
2219        }
2220        else
2221                hashclr(one->sha1);
2222}
2223
2224static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2225{
2226        /* Strip the prefix but do not molest /dev/null and absolute paths */
2227        if (*namep && **namep != '/')
2228                *namep += prefix_length;
2229        if (*otherp && **otherp != '/')
2230                *otherp += prefix_length;
2231}
2232
2233static void run_diff(struct diff_filepair *p, struct diff_options *o)
2234{
2235        const char *pgm = external_diff();
2236        struct strbuf msg;
2237        struct diff_filespec *one = p->one;
2238        struct diff_filespec *two = p->two;
2239        const char *name;
2240        const char *other;
2241        const char *attr_path;
2242
2243        name  = p->one->path;
2244        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2245        attr_path = name;
2246        if (o->prefix_length)
2247                strip_prefix(o->prefix_length, &name, &other);
2248
2249        if (DIFF_PAIR_UNMERGED(p)) {
2250                run_diff_cmd(pgm, name, NULL, attr_path,
2251                             NULL, NULL, NULL, o, p);
2252                return;
2253        }
2254
2255        diff_fill_sha1_info(one);
2256        diff_fill_sha1_info(two);
2257
2258        if (!pgm &&
2259            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2260            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2261                /*
2262                 * a filepair that changes between file and symlink
2263                 * needs to be split into deletion and creation.
2264                 */
2265                struct diff_filespec *null = alloc_filespec(two->path);
2266                run_diff_cmd(NULL, name, other, attr_path,
2267                             one, null, &msg, o, p);
2268                free(null);
2269                strbuf_release(&msg);
2270
2271                null = alloc_filespec(one->path);
2272                run_diff_cmd(NULL, name, other, attr_path,
2273                             null, two, &msg, o, p);
2274                free(null);
2275        }
2276        else
2277                run_diff_cmd(pgm, name, other, attr_path,
2278                             one, two, &msg, o, p);
2279
2280        strbuf_release(&msg);
2281}
2282
2283static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2284                         struct diffstat_t *diffstat)
2285{
2286        const char *name;
2287        const char *other;
2288        int complete_rewrite = 0;
2289
2290        if (DIFF_PAIR_UNMERGED(p)) {
2291                /* unmerged */
2292                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2293                return;
2294        }
2295
2296        name = p->one->path;
2297        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2298
2299        if (o->prefix_length)
2300                strip_prefix(o->prefix_length, &name, &other);
2301
2302        diff_fill_sha1_info(p->one);
2303        diff_fill_sha1_info(p->two);
2304
2305        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2306                complete_rewrite = 1;
2307        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2308}
2309
2310static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2311{
2312        const char *name;
2313        const char *other;
2314        const char *attr_path;
2315
2316        if (DIFF_PAIR_UNMERGED(p)) {
2317                /* unmerged */
2318                return;
2319        }
2320
2321        name = p->one->path;
2322        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2323        attr_path = other ? other : name;
2324
2325        if (o->prefix_length)
2326                strip_prefix(o->prefix_length, &name, &other);
2327
2328        diff_fill_sha1_info(p->one);
2329        diff_fill_sha1_info(p->two);
2330
2331        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2332}
2333
2334void diff_setup(struct diff_options *options)
2335{
2336        memset(options, 0, sizeof(*options));
2337
2338        options->file = stdout;
2339
2340        options->line_termination = '\n';
2341        options->break_opt = -1;
2342        options->rename_limit = -1;
2343        options->dirstat_percent = 3;
2344        options->context = 3;
2345
2346        options->change = diff_change;
2347        options->add_remove = diff_addremove;
2348        if (diff_use_color_default > 0)
2349                DIFF_OPT_SET(options, COLOR_DIFF);
2350        options->detect_rename = diff_detect_rename_default;
2351
2352        if (!diff_mnemonic_prefix) {
2353                options->a_prefix = "a/";
2354                options->b_prefix = "b/";
2355        }
2356}
2357
2358int diff_setup_done(struct diff_options *options)
2359{
2360        int count = 0;
2361
2362        if (options->output_format & DIFF_FORMAT_NAME)
2363                count++;
2364        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2365                count++;
2366        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2367                count++;
2368        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2369                count++;
2370        if (count > 1)
2371                die("--name-only, --name-status, --check and -s are mutually exclusive");
2372
2373        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2374                options->detect_rename = DIFF_DETECT_COPY;
2375
2376        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2377                options->prefix = NULL;
2378        if (options->prefix)
2379                options->prefix_length = strlen(options->prefix);
2380        else
2381                options->prefix_length = 0;
2382
2383        if (options->output_format & (DIFF_FORMAT_NAME |
2384                                      DIFF_FORMAT_NAME_STATUS |
2385                                      DIFF_FORMAT_CHECKDIFF |
2386                                      DIFF_FORMAT_NO_OUTPUT))
2387                options->output_format &= ~(DIFF_FORMAT_RAW |
2388                                            DIFF_FORMAT_NUMSTAT |
2389                                            DIFF_FORMAT_DIFFSTAT |
2390                                            DIFF_FORMAT_SHORTSTAT |
2391                                            DIFF_FORMAT_DIRSTAT |
2392                                            DIFF_FORMAT_SUMMARY |
2393                                            DIFF_FORMAT_PATCH);
2394
2395        /*
2396         * These cases always need recursive; we do not drop caller-supplied
2397         * recursive bits for other formats here.
2398         */
2399        if (options->output_format & (DIFF_FORMAT_PATCH |
2400                                      DIFF_FORMAT_NUMSTAT |
2401                                      DIFF_FORMAT_DIFFSTAT |
2402                                      DIFF_FORMAT_SHORTSTAT |
2403                                      DIFF_FORMAT_DIRSTAT |
2404                                      DIFF_FORMAT_SUMMARY |
2405                                      DIFF_FORMAT_CHECKDIFF))
2406                DIFF_OPT_SET(options, RECURSIVE);
2407        /*
2408         * Also pickaxe would not work very well if you do not say recursive
2409         */
2410        if (options->pickaxe)
2411                DIFF_OPT_SET(options, RECURSIVE);
2412
2413        if (options->detect_rename && options->rename_limit < 0)
2414                options->rename_limit = diff_rename_limit_default;
2415        if (options->setup & DIFF_SETUP_USE_CACHE) {
2416                if (!active_cache)
2417                        /* read-cache does not die even when it fails
2418                         * so it is safe for us to do this here.  Also
2419                         * it does not smudge active_cache or active_nr
2420                         * when it fails, so we do not have to worry about
2421                         * cleaning it up ourselves either.
2422                         */
2423                        read_cache();
2424        }
2425        if (options->abbrev <= 0 || 40 < options->abbrev)
2426                options->abbrev = 40; /* full */
2427
2428        /*
2429         * It does not make sense to show the first hit we happened
2430         * to have found.  It does not make sense not to return with
2431         * exit code in such a case either.
2432         */
2433        if (DIFF_OPT_TST(options, QUIET)) {
2434                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2435                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2436        }
2437
2438        return 0;
2439}
2440
2441static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2442{
2443        char c, *eq;
2444        int len;
2445
2446        if (*arg != '-')
2447                return 0;
2448        c = *++arg;
2449        if (!c)
2450                return 0;
2451        if (c == arg_short) {
2452                c = *++arg;
2453                if (!c)
2454                        return 1;
2455                if (val && isdigit(c)) {
2456                        char *end;
2457                        int n = strtoul(arg, &end, 10);
2458                        if (*end)
2459                                return 0;
2460                        *val = n;
2461                        return 1;
2462                }
2463                return 0;
2464        }
2465        if (c != '-')
2466                return 0;
2467        arg++;
2468        eq = strchr(arg, '=');
2469        if (eq)
2470                len = eq - arg;
2471        else
2472                len = strlen(arg);
2473        if (!len || strncmp(arg, arg_long, len))
2474                return 0;
2475        if (eq) {
2476                int n;
2477                char *end;
2478                if (!isdigit(*++eq))
2479                        return 0;
2480                n = strtoul(eq, &end, 10);
2481                if (*end)
2482                        return 0;
2483                *val = n;
2484        }
2485        return 1;
2486}
2487
2488static int diff_scoreopt_parse(const char *opt);
2489
2490int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2491{
2492        const char *arg = av[0];
2493
2494        /* Output format options */
2495        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2496                options->output_format |= DIFF_FORMAT_PATCH;
2497        else if (opt_arg(arg, 'U', "unified", &options->context))
2498                options->output_format |= DIFF_FORMAT_PATCH;
2499        else if (!strcmp(arg, "--raw"))
2500                options->output_format |= DIFF_FORMAT_RAW;
2501        else if (!strcmp(arg, "--patch-with-raw"))
2502                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2503        else if (!strcmp(arg, "--numstat"))
2504                options->output_format |= DIFF_FORMAT_NUMSTAT;
2505        else if (!strcmp(arg, "--shortstat"))
2506                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2507        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2508                options->output_format |= DIFF_FORMAT_DIRSTAT;
2509        else if (!strcmp(arg, "--cumulative")) {
2510                options->output_format |= DIFF_FORMAT_DIRSTAT;
2511                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2512        } else if (opt_arg(arg, 0, "dirstat-by-file",
2513                           &options->dirstat_percent)) {
2514                options->output_format |= DIFF_FORMAT_DIRSTAT;
2515                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2516        }
2517        else if (!strcmp(arg, "--check"))
2518                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2519        else if (!strcmp(arg, "--summary"))
2520                options->output_format |= DIFF_FORMAT_SUMMARY;
2521        else if (!strcmp(arg, "--patch-with-stat"))
2522                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2523        else if (!strcmp(arg, "--name-only"))
2524                options->output_format |= DIFF_FORMAT_NAME;
2525        else if (!strcmp(arg, "--name-status"))
2526                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2527        else if (!strcmp(arg, "-s"))
2528                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2529        else if (!prefixcmp(arg, "--stat")) {
2530                char *end;
2531                int width = options->stat_width;
2532                int name_width = options->stat_name_width;
2533                arg += 6;
2534                end = (char *)arg;
2535
2536                switch (*arg) {
2537                case '-':
2538                        if (!prefixcmp(arg, "-width="))
2539                                width = strtoul(arg + 7, &end, 10);
2540                        else if (!prefixcmp(arg, "-name-width="))
2541                                name_width = strtoul(arg + 12, &end, 10);
2542                        break;
2543                case '=':
2544                        width = strtoul(arg+1, &end, 10);
2545                        if (*end == ',')
2546                                name_width = strtoul(end+1, &end, 10);
2547                }
2548
2549                /* Important! This checks all the error cases! */
2550                if (*end)
2551                        return 0;
2552                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2553                options->stat_name_width = name_width;
2554                options->stat_width = width;
2555        }
2556
2557        /* renames options */
2558        else if (!prefixcmp(arg, "-B")) {
2559                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2560                        return -1;
2561        }
2562        else if (!prefixcmp(arg, "-M")) {
2563                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2564                        return -1;
2565                options->detect_rename = DIFF_DETECT_RENAME;
2566        }
2567        else if (!prefixcmp(arg, "-C")) {
2568                if (options->detect_rename == DIFF_DETECT_COPY)
2569                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2570                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2571                        return -1;
2572                options->detect_rename = DIFF_DETECT_COPY;
2573        }
2574        else if (!strcmp(arg, "--no-renames"))
2575                options->detect_rename = 0;
2576        else if (!strcmp(arg, "--relative"))
2577                DIFF_OPT_SET(options, RELATIVE_NAME);
2578        else if (!prefixcmp(arg, "--relative=")) {
2579                DIFF_OPT_SET(options, RELATIVE_NAME);
2580                options->prefix = arg + 11;
2581        }
2582
2583        /* xdiff options */
2584        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2585                options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2586        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2587                options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2588        else if (!strcmp(arg, "--ignore-space-at-eol"))
2589                options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2590        else if (!strcmp(arg, "--patience"))
2591                options->xdl_opts |= XDF_PATIENCE_DIFF;
2592
2593        /* flags options */
2594        else if (!strcmp(arg, "--binary")) {
2595                options->output_format |= DIFF_FORMAT_PATCH;
2596                DIFF_OPT_SET(options, BINARY);
2597        }
2598        else if (!strcmp(arg, "--full-index"))
2599                DIFF_OPT_SET(options, FULL_INDEX);
2600        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2601                DIFF_OPT_SET(options, TEXT);
2602        else if (!strcmp(arg, "-R"))
2603                DIFF_OPT_SET(options, REVERSE_DIFF);
2604        else if (!strcmp(arg, "--find-copies-harder"))
2605                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2606        else if (!strcmp(arg, "--follow"))
2607                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2608        else if (!strcmp(arg, "--color"))
2609                DIFF_OPT_SET(options, COLOR_DIFF);
2610        else if (!strcmp(arg, "--no-color"))
2611                DIFF_OPT_CLR(options, COLOR_DIFF);
2612        else if (!strcmp(arg, "--color-words"))
2613                options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2614        else if (!prefixcmp(arg, "--color-words=")) {
2615                options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2616                options->word_regex = arg + 14;
2617        }
2618        else if (!strcmp(arg, "--exit-code"))
2619                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2620        else if (!strcmp(arg, "--quiet"))
2621                DIFF_OPT_SET(options, QUIET);
2622        else if (!strcmp(arg, "--ext-diff"))
2623                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2624        else if (!strcmp(arg, "--no-ext-diff"))
2625                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2626        else if (!strcmp(arg, "--textconv"))
2627                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2628        else if (!strcmp(arg, "--no-textconv"))
2629                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2630        else if (!strcmp(arg, "--ignore-submodules"))
2631                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2632
2633        /* misc options */
2634        else if (!strcmp(arg, "-z"))
2635                options->line_termination = 0;
2636        else if (!prefixcmp(arg, "-l"))
2637                options->rename_limit = strtoul(arg+2, NULL, 10);
2638        else if (!prefixcmp(arg, "-S"))
2639                options->pickaxe = arg + 2;
2640        else if (!strcmp(arg, "--pickaxe-all"))
2641                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2642        else if (!strcmp(arg, "--pickaxe-regex"))
2643                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2644        else if (!prefixcmp(arg, "-O"))
2645                options->orderfile = arg + 2;
2646        else if (!prefixcmp(arg, "--diff-filter="))
2647                options->filter = arg + 14;
2648        else if (!strcmp(arg, "--abbrev"))
2649                options->abbrev = DEFAULT_ABBREV;
2650        else if (!prefixcmp(arg, "--abbrev=")) {
2651                options->abbrev = strtoul(arg + 9, NULL, 10);
2652                if (options->abbrev < MINIMUM_ABBREV)
2653                        options->abbrev = MINIMUM_ABBREV;
2654                else if (40 < options->abbrev)
2655                        options->abbrev = 40;
2656        }
2657        else if (!prefixcmp(arg, "--src-prefix="))
2658                options->a_prefix = arg + 13;
2659        else if (!prefixcmp(arg, "--dst-prefix="))
2660                options->b_prefix = arg + 13;
2661        else if (!strcmp(arg, "--no-prefix"))
2662                options->a_prefix = options->b_prefix = "";
2663        else if (opt_arg(arg, '\0', "inter-hunk-context",
2664                         &options->interhunkcontext))
2665                ;
2666        else if (!prefixcmp(arg, "--output=")) {
2667                options->file = fopen(arg + strlen("--output="), "w");
2668                options->close_file = 1;
2669        } else
2670                return 0;
2671        return 1;
2672}
2673
2674static int parse_num(const char **cp_p)
2675{
2676        unsigned long num, scale;
2677        int ch, dot;
2678        const char *cp = *cp_p;
2679
2680        num = 0;
2681        scale = 1;
2682        dot = 0;
2683        for(;;) {
2684                ch = *cp;
2685                if ( !dot && ch == '.' ) {
2686                        scale = 1;
2687                        dot = 1;
2688                } else if ( ch == '%' ) {
2689                        scale = dot ? scale*100 : 100;
2690                        cp++;   /* % is always at the end */
2691                        break;
2692                } else if ( ch >= '0' && ch <= '9' ) {
2693                        if ( scale < 100000 ) {
2694                                scale *= 10;
2695                                num = (num*10) + (ch-'0');
2696                        }
2697                } else {
2698                        break;
2699                }
2700                cp++;
2701        }
2702        *cp_p = cp;
2703
2704        /* user says num divided by scale and we say internally that
2705         * is MAX_SCORE * num / scale.
2706         */
2707        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2708}
2709
2710static int diff_scoreopt_parse(const char *opt)
2711{
2712        int opt1, opt2, cmd;
2713
2714        if (*opt++ != '-')
2715                return -1;
2716        cmd = *opt++;
2717        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2718                return -1; /* that is not a -M, -C nor -B option */
2719
2720        opt1 = parse_num(&opt);
2721        if (cmd != 'B')
2722                opt2 = 0;
2723        else {
2724                if (*opt == 0)
2725                        opt2 = 0;
2726                else if (*opt != '/')
2727                        return -1; /* we expect -B80/99 or -B80 */
2728                else {
2729                        opt++;
2730                        opt2 = parse_num(&opt);
2731                }
2732        }
2733        if (*opt != 0)
2734                return -1;
2735        return opt1 | (opt2 << 16);
2736}
2737
2738struct diff_queue_struct diff_queued_diff;
2739
2740void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2741{
2742        if (queue->alloc <= queue->nr) {
2743                queue->alloc = alloc_nr(queue->alloc);
2744                queue->queue = xrealloc(queue->queue,
2745                                        sizeof(dp) * queue->alloc);
2746        }
2747        queue->queue[queue->nr++] = dp;
2748}
2749
2750struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2751                                 struct diff_filespec *one,
2752                                 struct diff_filespec *two)
2753{
2754        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2755        dp->one = one;
2756        dp->two = two;
2757        if (queue)
2758                diff_q(queue, dp);
2759        return dp;
2760}
2761
2762void diff_free_filepair(struct diff_filepair *p)
2763{
2764        free_filespec(p->one);
2765        free_filespec(p->two);
2766        free(p);
2767}
2768
2769/* This is different from find_unique_abbrev() in that
2770 * it stuffs the result with dots for alignment.
2771 */
2772const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2773{
2774        int abblen;
2775        const char *abbrev;
2776        if (len == 40)
2777                return sha1_to_hex(sha1);
2778
2779        abbrev = find_unique_abbrev(sha1, len);
2780        abblen = strlen(abbrev);
2781        if (abblen < 37) {
2782                static char hex[41];
2783                if (len < abblen && abblen <= len + 2)
2784                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2785                else
2786                        sprintf(hex, "%s...", abbrev);
2787                return hex;
2788        }
2789        return sha1_to_hex(sha1);
2790}
2791
2792static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2793{
2794        int line_termination = opt->line_termination;
2795        int inter_name_termination = line_termination ? '\t' : '\0';
2796
2797        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2798                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2799                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
2800                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2801        }
2802        if (p->score) {
2803                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2804                        inter_name_termination);
2805        } else {
2806                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2807        }
2808
2809        if (p->status == DIFF_STATUS_COPIED ||
2810            p->status == DIFF_STATUS_RENAMED) {
2811                const char *name_a, *name_b;
2812                name_a = p->one->path;
2813                name_b = p->two->path;
2814                strip_prefix(opt->prefix_length, &name_a, &name_b);
2815                write_name_quoted(name_a, opt->file, inter_name_termination);
2816                write_name_quoted(name_b, opt->file, line_termination);
2817        } else {
2818                const char *name_a, *name_b;
2819                name_a = p->one->mode ? p->one->path : p->two->path;
2820                name_b = NULL;
2821                strip_prefix(opt->prefix_length, &name_a, &name_b);
2822                write_name_quoted(name_a, opt->file, line_termination);
2823        }
2824}
2825
2826int diff_unmodified_pair(struct diff_filepair *p)
2827{
2828        /* This function is written stricter than necessary to support
2829         * the currently implemented transformers, but the idea is to
2830         * let transformers to produce diff_filepairs any way they want,
2831         * and filter and clean them up here before producing the output.
2832         */
2833        struct diff_filespec *one = p->one, *two = p->two;
2834
2835        if (DIFF_PAIR_UNMERGED(p))
2836                return 0; /* unmerged is interesting */
2837
2838        /* deletion, addition, mode or type change
2839         * and rename are all interesting.
2840         */
2841        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2842            DIFF_PAIR_MODE_CHANGED(p) ||
2843            strcmp(one->path, two->path))
2844                return 0;
2845
2846        /* both are valid and point at the same path.  that is, we are
2847         * dealing with a change.
2848         */
2849        if (one->sha1_valid && two->sha1_valid &&
2850            !hashcmp(one->sha1, two->sha1))
2851                return 1; /* no change */
2852        if (!one->sha1_valid && !two->sha1_valid)
2853                return 1; /* both look at the same file on the filesystem. */
2854        return 0;
2855}
2856
2857static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2858{
2859        if (diff_unmodified_pair(p))
2860                return;
2861
2862        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2863            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2864                return; /* no tree diffs in patch format */
2865
2866        run_diff(p, o);
2867}
2868
2869static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2870                            struct diffstat_t *diffstat)
2871{
2872        if (diff_unmodified_pair(p))
2873                return;
2874
2875        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2876            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2877                return; /* no tree diffs in patch format */
2878
2879        run_diffstat(p, o, diffstat);
2880}
2881
2882static void diff_flush_checkdiff(struct diff_filepair *p,
2883                struct diff_options *o)
2884{
2885        if (diff_unmodified_pair(p))
2886                return;
2887
2888        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2889            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2890                return; /* no tree diffs in patch format */
2891
2892        run_checkdiff(p, o);
2893}
2894
2895int diff_queue_is_empty(void)
2896{
2897        struct diff_queue_struct *q = &diff_queued_diff;
2898        int i;
2899        for (i = 0; i < q->nr; i++)
2900                if (!diff_unmodified_pair(q->queue[i]))
2901                        return 0;
2902        return 1;
2903}
2904
2905#if DIFF_DEBUG
2906void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2907{
2908        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2909                x, one ? one : "",
2910                s->path,
2911                DIFF_FILE_VALID(s) ? "valid" : "invalid",
2912                s->mode,
2913                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2914        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2915                x, one ? one : "",
2916                s->size, s->xfrm_flags);
2917}
2918
2919void diff_debug_filepair(const struct diff_filepair *p, int i)
2920{
2921        diff_debug_filespec(p->one, i, "one");
2922        diff_debug_filespec(p->two, i, "two");
2923        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2924                p->score, p->status ? p->status : '?',
2925                p->one->rename_used, p->broken_pair);
2926}
2927
2928void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2929{
2930        int i;
2931        if (msg)
2932                fprintf(stderr, "%s\n", msg);
2933        fprintf(stderr, "q->nr = %d\n", q->nr);
2934        for (i = 0; i < q->nr; i++) {
2935                struct diff_filepair *p = q->queue[i];
2936                diff_debug_filepair(p, i);
2937        }
2938}
2939#endif
2940
2941static void diff_resolve_rename_copy(void)
2942{
2943        int i;
2944        struct diff_filepair *p;
2945        struct diff_queue_struct *q = &diff_queued_diff;
2946
2947        diff_debug_queue("resolve-rename-copy", q);
2948
2949        for (i = 0; i < q->nr; i++) {
2950                p = q->queue[i];
2951                p->status = 0; /* undecided */
2952                if (DIFF_PAIR_UNMERGED(p))
2953                        p->status = DIFF_STATUS_UNMERGED;
2954                else if (!DIFF_FILE_VALID(p->one))
2955                        p->status = DIFF_STATUS_ADDED;
2956                else if (!DIFF_FILE_VALID(p->two))
2957                        p->status = DIFF_STATUS_DELETED;
2958                else if (DIFF_PAIR_TYPE_CHANGED(p))
2959                        p->status = DIFF_STATUS_TYPE_CHANGED;
2960
2961                /* from this point on, we are dealing with a pair
2962                 * whose both sides are valid and of the same type, i.e.
2963                 * either in-place edit or rename/copy edit.
2964                 */
2965                else if (DIFF_PAIR_RENAME(p)) {
2966                        /*
2967                         * A rename might have re-connected a broken
2968                         * pair up, causing the pathnames to be the
2969                         * same again. If so, that's not a rename at
2970                         * all, just a modification..
2971                         *
2972                         * Otherwise, see if this source was used for
2973                         * multiple renames, in which case we decrement
2974                         * the count, and call it a copy.
2975                         */
2976                        if (!strcmp(p->one->path, p->two->path))
2977                                p->status = DIFF_STATUS_MODIFIED;
2978                        else if (--p->one->rename_used > 0)
2979                                p->status = DIFF_STATUS_COPIED;
2980                        else
2981                                p->status = DIFF_STATUS_RENAMED;
2982                }
2983                else if (hashcmp(p->one->sha1, p->two->sha1) ||
2984                         p->one->mode != p->two->mode ||
2985                         is_null_sha1(p->one->sha1))
2986                        p->status = DIFF_STATUS_MODIFIED;
2987                else {
2988                        /* This is a "no-change" entry and should not
2989                         * happen anymore, but prepare for broken callers.
2990                         */
2991                        error("feeding unmodified %s to diffcore",
2992                              p->one->path);
2993                        p->status = DIFF_STATUS_UNKNOWN;
2994                }
2995        }
2996        diff_debug_queue("resolve-rename-copy done", q);
2997}
2998
2999static int check_pair_status(struct diff_filepair *p)
3000{
3001        switch (p->status) {
3002        case DIFF_STATUS_UNKNOWN:
3003                return 0;
3004        case 0:
3005                die("internal error in diff-resolve-rename-copy");
3006        default:
3007                return 1;
3008        }
3009}
3010
3011static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3012{
3013        int fmt = opt->output_format;
3014
3015        if (fmt & DIFF_FORMAT_CHECKDIFF)
3016                diff_flush_checkdiff(p, opt);
3017        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3018                diff_flush_raw(p, opt);
3019        else if (fmt & DIFF_FORMAT_NAME) {
3020                const char *name_a, *name_b;
3021                name_a = p->two->path;
3022                name_b = NULL;
3023                strip_prefix(opt->prefix_length, &name_a, &name_b);
3024                write_name_quoted(name_a, opt->file, opt->line_termination);
3025        }
3026}
3027
3028static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3029{
3030        if (fs->mode)
3031                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3032        else
3033                fprintf(file, " %s ", newdelete);
3034        write_name_quoted(fs->path, file, '\n');
3035}
3036
3037
3038static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3039{
3040        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3041                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3042                        show_name ? ' ' : '\n');
3043                if (show_name) {
3044                        write_name_quoted(p->two->path, file, '\n');
3045                }
3046        }
3047}
3048
3049static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3050{
3051        char *names = pprint_rename(p->one->path, p->two->path);
3052
3053        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3054        free(names);
3055        show_mode_change(file, p, 0);
3056}
3057
3058static void diff_summary(FILE *file, struct diff_filepair *p)
3059{
3060        switch(p->status) {
3061        case DIFF_STATUS_DELETED:
3062                show_file_mode_name(file, "delete", p->one);
3063                break;
3064        case DIFF_STATUS_ADDED:
3065                show_file_mode_name(file, "create", p->two);
3066                break;
3067        case DIFF_STATUS_COPIED:
3068                show_rename_copy(file, "copy", p);
3069                break;
3070        case DIFF_STATUS_RENAMED:
3071                show_rename_copy(file, "rename", p);
3072                break;
3073        default:
3074                if (p->score) {
3075                        fputs(" rewrite ", file);
3076                        write_name_quoted(p->two->path, file, ' ');
3077                        fprintf(file, "(%d%%)\n", similarity_index(p));
3078                }
3079                show_mode_change(file, p, !p->score);
3080                break;
3081        }
3082}
3083
3084struct patch_id_t {
3085        git_SHA_CTX *ctx;
3086        int patchlen;
3087};
3088
3089static int remove_space(char *line, int len)
3090{
3091        int i;
3092        char *dst = line;
3093        unsigned char c;
3094
3095        for (i = 0; i < len; i++)
3096                if (!isspace((c = line[i])))
3097                        *dst++ = c;
3098
3099        return dst - line;
3100}
3101
3102static void patch_id_consume(void *priv, char *line, unsigned long len)
3103{
3104        struct patch_id_t *data = priv;
3105        int new_len;
3106
3107        /* Ignore line numbers when computing the SHA1 of the patch */
3108        if (!prefixcmp(line, "@@ -"))
3109                return;
3110
3111        new_len = remove_space(line, len);
3112
3113        git_SHA1_Update(data->ctx, line, new_len);
3114        data->patchlen += new_len;
3115}
3116
3117/* returns 0 upon success, and writes result into sha1 */
3118static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3119{
3120        struct diff_queue_struct *q = &diff_queued_diff;
3121        int i;
3122        git_SHA_CTX ctx;
3123        struct patch_id_t data;
3124        char buffer[PATH_MAX * 4 + 20];
3125
3126        git_SHA1_Init(&ctx);
3127        memset(&data, 0, sizeof(struct patch_id_t));
3128        data.ctx = &ctx;
3129
3130        for (i = 0; i < q->nr; i++) {
3131                xpparam_t xpp;
3132                xdemitconf_t xecfg;
3133                xdemitcb_t ecb;
3134                mmfile_t mf1, mf2;
3135                struct diff_filepair *p = q->queue[i];
3136                int len1, len2;
3137
3138                memset(&xpp, 0, sizeof(xpp));
3139                memset(&xecfg, 0, sizeof(xecfg));
3140                if (p->status == 0)
3141                        return error("internal diff status error");
3142                if (p->status == DIFF_STATUS_UNKNOWN)
3143                        continue;
3144                if (diff_unmodified_pair(p))
3145                        continue;
3146                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3147                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3148                        continue;
3149                if (DIFF_PAIR_UNMERGED(p))
3150                        continue;
3151
3152                diff_fill_sha1_info(p->one);
3153                diff_fill_sha1_info(p->two);
3154                if (fill_mmfile(&mf1, p->one) < 0 ||
3155                                fill_mmfile(&mf2, p->two) < 0)
3156                        return error("unable to read files to diff");
3157
3158                len1 = remove_space(p->one->path, strlen(p->one->path));
3159                len2 = remove_space(p->two->path, strlen(p->two->path));
3160                if (p->one->mode == 0)
3161                        len1 = snprintf(buffer, sizeof(buffer),
3162                                        "diff--gita/%.*sb/%.*s"
3163                                        "newfilemode%06o"
3164                                        "---/dev/null"
3165                                        "+++b/%.*s",
3166                                        len1, p->one->path,
3167                                        len2, p->two->path,
3168                                        p->two->mode,
3169                                        len2, p->two->path);
3170                else if (p->two->mode == 0)
3171                        len1 = snprintf(buffer, sizeof(buffer),
3172                                        "diff--gita/%.*sb/%.*s"
3173                                        "deletedfilemode%06o"
3174                                        "---a/%.*s"
3175                                        "+++/dev/null",
3176                                        len1, p->one->path,
3177                                        len2, p->two->path,
3178                                        p->one->mode,
3179                                        len1, p->one->path);
3180                else
3181                        len1 = snprintf(buffer, sizeof(buffer),
3182                                        "diff--gita/%.*sb/%.*s"
3183                                        "---a/%.*s"
3184                                        "+++b/%.*s",
3185                                        len1, p->one->path,
3186                                        len2, p->two->path,
3187                                        len1, p->one->path,
3188                                        len2, p->two->path);
3189                git_SHA1_Update(&ctx, buffer, len1);
3190
3191                xpp.flags = XDF_NEED_MINIMAL;
3192                xecfg.ctxlen = 3;
3193                xecfg.flags = XDL_EMIT_FUNCNAMES;
3194                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3195                              &xpp, &xecfg, &ecb);
3196        }
3197
3198        git_SHA1_Final(sha1, &ctx);
3199        return 0;
3200}
3201
3202int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3203{
3204        struct diff_queue_struct *q = &diff_queued_diff;
3205        int i;
3206        int result = diff_get_patch_id(options, sha1);
3207
3208        for (i = 0; i < q->nr; i++)
3209                diff_free_filepair(q->queue[i]);
3210
3211        free(q->queue);
3212        q->queue = NULL;
3213        q->nr = q->alloc = 0;
3214
3215        return result;
3216}
3217
3218static int is_summary_empty(const struct diff_queue_struct *q)
3219{
3220        int i;
3221
3222        for (i = 0; i < q->nr; i++) {
3223                const struct diff_filepair *p = q->queue[i];
3224
3225                switch (p->status) {
3226                case DIFF_STATUS_DELETED:
3227                case DIFF_STATUS_ADDED:
3228                case DIFF_STATUS_COPIED:
3229                case DIFF_STATUS_RENAMED:
3230                        return 0;
3231                default:
3232                        if (p->score)
3233                                return 0;
3234                        if (p->one->mode && p->two->mode &&
3235                            p->one->mode != p->two->mode)
3236                                return 0;
3237                        break;
3238                }
3239        }
3240        return 1;
3241}
3242
3243void diff_flush(struct diff_options *options)
3244{
3245        struct diff_queue_struct *q = &diff_queued_diff;
3246        int i, output_format = options->output_format;
3247        int separator = 0;
3248
3249        /*
3250         * Order: raw, stat, summary, patch
3251         * or:    name/name-status/checkdiff (other bits clear)
3252         */
3253        if (!q->nr)
3254                goto free_queue;
3255
3256        if (output_format & (DIFF_FORMAT_RAW |
3257                             DIFF_FORMAT_NAME |
3258                             DIFF_FORMAT_NAME_STATUS |
3259                             DIFF_FORMAT_CHECKDIFF)) {
3260                for (i = 0; i < q->nr; i++) {
3261                        struct diff_filepair *p = q->queue[i];
3262                        if (check_pair_status(p))
3263                                flush_one_pair(p, options);
3264                }
3265                separator++;
3266        }
3267
3268        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3269                struct diffstat_t diffstat;
3270
3271                memset(&diffstat, 0, sizeof(struct diffstat_t));
3272                for (i = 0; i < q->nr; i++) {
3273                        struct diff_filepair *p = q->queue[i];
3274                        if (check_pair_status(p))
3275                                diff_flush_stat(p, options, &diffstat);
3276                }
3277                if (output_format & DIFF_FORMAT_NUMSTAT)
3278                        show_numstat(&diffstat, options);
3279                if (output_format & DIFF_FORMAT_DIFFSTAT)
3280                        show_stats(&diffstat, options);
3281                if (output_format & DIFF_FORMAT_SHORTSTAT)
3282                        show_shortstats(&diffstat, options);
3283                free_diffstat_info(&diffstat);
3284                separator++;
3285        }
3286        if (output_format & DIFF_FORMAT_DIRSTAT)
3287                show_dirstat(options);
3288
3289        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3290                for (i = 0; i < q->nr; i++)
3291                        diff_summary(options->file, q->queue[i]);
3292                separator++;
3293        }
3294
3295        if (output_format & DIFF_FORMAT_PATCH) {
3296                if (separator) {
3297                        putc(options->line_termination, options->file);
3298                        if (options->stat_sep) {
3299                                /* attach patch instead of inline */
3300                                fputs(options->stat_sep, options->file);
3301                        }
3302                }
3303
3304                for (i = 0; i < q->nr; i++) {
3305                        struct diff_filepair *p = q->queue[i];
3306                        if (check_pair_status(p))
3307                                diff_flush_patch(p, options);
3308                }
3309        }
3310
3311        if (output_format & DIFF_FORMAT_CALLBACK)
3312                options->format_callback(q, options, options->format_callback_data);
3313
3314        for (i = 0; i < q->nr; i++)
3315                diff_free_filepair(q->queue[i]);
3316free_queue:
3317        free(q->queue);
3318        q->queue = NULL;
3319        q->nr = q->alloc = 0;
3320        if (options->close_file)
3321                fclose(options->file);
3322}
3323
3324static void diffcore_apply_filter(const char *filter)
3325{
3326        int i;
3327        struct diff_queue_struct *q = &diff_queued_diff;
3328        struct diff_queue_struct outq;
3329        outq.queue = NULL;
3330        outq.nr = outq.alloc = 0;
3331
3332        if (!filter)
3333                return;
3334
3335        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3336                int found;
3337                for (i = found = 0; !found && i < q->nr; i++) {
3338                        struct diff_filepair *p = q->queue[i];
3339                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3340                             ((p->score &&
3341                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3342                              (!p->score &&
3343                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3344                            ((p->status != DIFF_STATUS_MODIFIED) &&
3345                             strchr(filter, p->status)))
3346                                found++;
3347                }
3348                if (found)
3349                        return;
3350
3351                /* otherwise we will clear the whole queue
3352                 * by copying the empty outq at the end of this
3353                 * function, but first clear the current entries
3354                 * in the queue.
3355                 */
3356                for (i = 0; i < q->nr; i++)
3357                        diff_free_filepair(q->queue[i]);
3358        }
3359        else {
3360                /* Only the matching ones */
3361                for (i = 0; i < q->nr; i++) {
3362                        struct diff_filepair *p = q->queue[i];
3363
3364                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3365                             ((p->score &&
3366                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3367                              (!p->score &&
3368                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3369                            ((p->status != DIFF_STATUS_MODIFIED) &&
3370                             strchr(filter, p->status)))
3371                                diff_q(&outq, p);
3372                        else
3373                                diff_free_filepair(p);
3374                }
3375        }
3376        free(q->queue);
3377        *q = outq;
3378}
3379
3380/* Check whether two filespecs with the same mode and size are identical */
3381static int diff_filespec_is_identical(struct diff_filespec *one,
3382                                      struct diff_filespec *two)
3383{
3384        if (S_ISGITLINK(one->mode))
3385                return 0;
3386        if (diff_populate_filespec(one, 0))
3387                return 0;
3388        if (diff_populate_filespec(two, 0))
3389                return 0;
3390        return !memcmp(one->data, two->data, one->size);
3391}
3392
3393static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3394{
3395        int i;
3396        struct diff_queue_struct *q = &diff_queued_diff;
3397        struct diff_queue_struct outq;
3398        outq.queue = NULL;
3399        outq.nr = outq.alloc = 0;
3400
3401        for (i = 0; i < q->nr; i++) {
3402                struct diff_filepair *p = q->queue[i];
3403
3404                /*
3405                 * 1. Entries that come from stat info dirtyness
3406                 *    always have both sides (iow, not create/delete),
3407                 *    one side of the object name is unknown, with
3408                 *    the same mode and size.  Keep the ones that
3409                 *    do not match these criteria.  They have real
3410                 *    differences.
3411                 *
3412                 * 2. At this point, the file is known to be modified,
3413                 *    with the same mode and size, and the object
3414                 *    name of one side is unknown.  Need to inspect
3415                 *    the identical contents.
3416                 */
3417                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3418                    !DIFF_FILE_VALID(p->two) ||
3419                    (p->one->sha1_valid && p->two->sha1_valid) ||
3420                    (p->one->mode != p->two->mode) ||
3421                    diff_populate_filespec(p->one, 1) ||
3422                    diff_populate_filespec(p->two, 1) ||
3423                    (p->one->size != p->two->size) ||
3424                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3425                        diff_q(&outq, p);
3426                else {
3427                        /*
3428                         * The caller can subtract 1 from skip_stat_unmatch
3429                         * to determine how many paths were dirty only
3430                         * due to stat info mismatch.
3431                         */
3432                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3433                                diffopt->skip_stat_unmatch++;
3434                        diff_free_filepair(p);
3435                }
3436        }
3437        free(q->queue);
3438        *q = outq;
3439}
3440
3441void diffcore_std(struct diff_options *options)
3442{
3443        if (options->skip_stat_unmatch)
3444                diffcore_skip_stat_unmatch(options);
3445        if (options->break_opt != -1)
3446                diffcore_break(options->break_opt);
3447        if (options->detect_rename)
3448                diffcore_rename(options);
3449        if (options->break_opt != -1)
3450                diffcore_merge_broken();
3451        if (options->pickaxe)
3452                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3453        if (options->orderfile)
3454                diffcore_order(options->orderfile);
3455        diff_resolve_rename_copy();
3456        diffcore_apply_filter(options->filter);
3457
3458        if (diff_queued_diff.nr)
3459                DIFF_OPT_SET(options, HAS_CHANGES);
3460        else
3461                DIFF_OPT_CLR(options, HAS_CHANGES);
3462}
3463
3464int diff_result_code(struct diff_options *opt, int status)
3465{
3466        int result = 0;
3467        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3468            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3469                return status;
3470        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3471            DIFF_OPT_TST(opt, HAS_CHANGES))
3472                result |= 01;
3473        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3474            DIFF_OPT_TST(opt, CHECK_FAILED))
3475                result |= 02;
3476        return result;
3477}
3478
3479void diff_addremove(struct diff_options *options,
3480                    int addremove, unsigned mode,
3481                    const unsigned char *sha1,
3482                    const char *concatpath)
3483{
3484        struct diff_filespec *one, *two;
3485
3486        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3487                return;
3488
3489        /* This may look odd, but it is a preparation for
3490         * feeding "there are unchanged files which should
3491         * not produce diffs, but when you are doing copy
3492         * detection you would need them, so here they are"
3493         * entries to the diff-core.  They will be prefixed
3494         * with something like '=' or '*' (I haven't decided
3495         * which but should not make any difference).
3496         * Feeding the same new and old to diff_change()
3497         * also has the same effect.
3498         * Before the final output happens, they are pruned after
3499         * merged into rename/copy pairs as appropriate.
3500         */
3501        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3502                addremove = (addremove == '+' ? '-' :
3503                             addremove == '-' ? '+' : addremove);
3504
3505        if (options->prefix &&
3506            strncmp(concatpath, options->prefix, options->prefix_length))
3507                return;
3508
3509        one = alloc_filespec(concatpath);
3510        two = alloc_filespec(concatpath);
3511
3512        if (addremove != '+')
3513                fill_filespec(one, sha1, mode);
3514        if (addremove != '-')
3515                fill_filespec(two, sha1, mode);
3516
3517        diff_queue(&diff_queued_diff, one, two);
3518        DIFF_OPT_SET(options, HAS_CHANGES);
3519}
3520
3521void diff_change(struct diff_options *options,
3522                 unsigned old_mode, unsigned new_mode,
3523                 const unsigned char *old_sha1,
3524                 const unsigned char *new_sha1,
3525                 const char *concatpath)
3526{
3527        struct diff_filespec *one, *two;
3528
3529        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3530                        && S_ISGITLINK(new_mode))
3531                return;
3532
3533        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3534                unsigned tmp;
3535                const unsigned char *tmp_c;
3536                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3537                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3538        }
3539
3540        if (options->prefix &&
3541            strncmp(concatpath, options->prefix, options->prefix_length))
3542                return;
3543
3544        one = alloc_filespec(concatpath);
3545        two = alloc_filespec(concatpath);
3546        fill_filespec(one, old_sha1, old_mode);
3547        fill_filespec(two, new_sha1, new_mode);
3548
3549        diff_queue(&diff_queued_diff, one, two);
3550        DIFF_OPT_SET(options, HAS_CHANGES);
3551}
3552
3553void diff_unmerge(struct diff_options *options,
3554                  const char *path,
3555                  unsigned mode, const unsigned char *sha1)
3556{
3557        struct diff_filespec *one, *two;
3558
3559        if (options->prefix &&
3560            strncmp(path, options->prefix, options->prefix_length))
3561                return;
3562
3563        one = alloc_filespec(path);
3564        two = alloc_filespec(path);
3565        fill_filespec(one, sha1, mode);
3566        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3567}
3568
3569static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3570                size_t *outsize)
3571{
3572        struct diff_tempfile *temp;
3573        const char *argv[3];
3574        const char **arg = argv;
3575        struct child_process child;
3576        struct strbuf buf = STRBUF_INIT;
3577
3578        temp = prepare_temp_file(spec->path, spec);
3579        *arg++ = pgm;
3580        *arg++ = temp->name;
3581        *arg = NULL;
3582
3583        memset(&child, 0, sizeof(child));
3584        child.argv = argv;
3585        child.out = -1;
3586        if (start_command(&child) != 0 ||
3587            strbuf_read(&buf, child.out, 0) < 0 ||
3588            finish_command(&child) != 0) {
3589                remove_tempfile();
3590                error("error running textconv command '%s'", pgm);
3591                return NULL;
3592        }
3593        remove_tempfile();
3594
3595        return strbuf_detach(&buf, outsize);
3596}