diff.con commit Merge branch 'lt/rev-list' into next (6aba8fa)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include <sys/types.h>
   5#include <sys/wait.h>
   6#include <signal.h>
   7#include "cache.h"
   8#include "quote.h"
   9#include "diff.h"
  10#include "diffcore.h"
  11
  12static const char *diff_opts = "-pu";
  13
  14static int use_size_cache;
  15
  16int diff_rename_limit_default = -1;
  17
  18int git_diff_config(const char *var, const char *value)
  19{
  20        if (!strcmp(var, "diff.renamelimit")) {
  21                diff_rename_limit_default = git_config_int(var, value);
  22                return 0;
  23        }
  24
  25        return git_default_config(var, value);
  26}
  27
  28static char *quote_one(const char *str)
  29{
  30        int needlen;
  31        char *xp;
  32
  33        if (!str)
  34                return NULL;
  35        needlen = quote_c_style(str, NULL, NULL, 0);
  36        if (!needlen)
  37                return strdup(str);
  38        xp = xmalloc(needlen + 1);
  39        quote_c_style(str, xp, NULL, 0);
  40        return xp;
  41}
  42
  43static char *quote_two(const char *one, const char *two)
  44{
  45        int need_one = quote_c_style(one, NULL, NULL, 1);
  46        int need_two = quote_c_style(two, NULL, NULL, 1);
  47        char *xp;
  48
  49        if (need_one + need_two) {
  50                if (!need_one) need_one = strlen(one);
  51                if (!need_two) need_one = strlen(two);
  52
  53                xp = xmalloc(need_one + need_two + 3);
  54                xp[0] = '"';
  55                quote_c_style(one, xp + 1, NULL, 1);
  56                quote_c_style(two, xp + need_one + 1, NULL, 1);
  57                strcpy(xp + need_one + need_two + 1, "\"");
  58                return xp;
  59        }
  60        need_one = strlen(one);
  61        need_two = strlen(two);
  62        xp = xmalloc(need_one + need_two + 1);
  63        strcpy(xp, one);
  64        strcpy(xp + need_one, two);
  65        return xp;
  66}
  67
  68static const char *external_diff(void)
  69{
  70        static const char *external_diff_cmd = NULL;
  71        static int done_preparing = 0;
  72        const char *env_diff_opts;
  73
  74        if (done_preparing)
  75                return external_diff_cmd;
  76
  77        /*
  78         * Default values above are meant to match the
  79         * Linux kernel development style.  Examples of
  80         * alternative styles you can specify via environment
  81         * variables are:
  82         *
  83         * GIT_DIFF_OPTS="-c";
  84         */
  85        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
  86
  87        /* In case external diff fails... */
  88        env_diff_opts = getenv("GIT_DIFF_OPTS");
  89        if (env_diff_opts) diff_opts = env_diff_opts;
  90
  91        done_preparing = 1;
  92        return external_diff_cmd;
  93}
  94
  95#define TEMPFILE_PATH_LEN               50
  96
  97static struct diff_tempfile {
  98        const char *name; /* filename external diff should read from */
  99        char hex[41];
 100        char mode[10];
 101        char tmp_path[TEMPFILE_PATH_LEN];
 102} diff_temp[2];
 103
 104static int count_lines(const char *filename)
 105{
 106        FILE *in;
 107        int count, ch, completely_empty = 1, nl_just_seen = 0;
 108        in = fopen(filename, "r");
 109        count = 0;
 110        while ((ch = fgetc(in)) != EOF)
 111                if (ch == '\n') {
 112                        count++;
 113                        nl_just_seen = 1;
 114                        completely_empty = 0;
 115                }
 116                else {
 117                        nl_just_seen = 0;
 118                        completely_empty = 0;
 119                }
 120        fclose(in);
 121        if (completely_empty)
 122                return 0;
 123        if (!nl_just_seen)
 124                count++; /* no trailing newline */
 125        return count;
 126}
 127
 128static void print_line_count(int count)
 129{
 130        switch (count) {
 131        case 0:
 132                printf("0,0");
 133                break;
 134        case 1:
 135                printf("1");
 136                break;
 137        default:
 138                printf("1,%d", count);
 139                break;
 140        }
 141}
 142
 143static void copy_file(int prefix, const char *filename)
 144{
 145        FILE *in;
 146        int ch, nl_just_seen = 1;
 147        in = fopen(filename, "r");
 148        while ((ch = fgetc(in)) != EOF) {
 149                if (nl_just_seen)
 150                        putchar(prefix);
 151                putchar(ch);
 152                if (ch == '\n')
 153                        nl_just_seen = 1;
 154                else
 155                        nl_just_seen = 0;
 156        }
 157        fclose(in);
 158        if (!nl_just_seen)
 159                printf("\n\\ No newline at end of file\n");
 160}
 161
 162static void emit_rewrite_diff(const char *name_a,
 163                              const char *name_b,
 164                              struct diff_tempfile *temp)
 165{
 166        /* Use temp[i].name as input, name_a and name_b as labels */
 167        int lc_a, lc_b;
 168        lc_a = count_lines(temp[0].name);
 169        lc_b = count_lines(temp[1].name);
 170        printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 171        print_line_count(lc_a);
 172        printf(" +");
 173        print_line_count(lc_b);
 174        printf(" @@\n");
 175        if (lc_a)
 176                copy_file('-', temp[0].name);
 177        if (lc_b)
 178                copy_file('+', temp[1].name);
 179}
 180
 181static const char *builtin_diff(const char *name_a,
 182                         const char *name_b,
 183                         struct diff_tempfile *temp,
 184                         const char *xfrm_msg,
 185                         int complete_rewrite,
 186                         const char **args)
 187{
 188        int i, next_at, cmd_size;
 189        const char *const diff_cmd = "diff -L%s -L%s";
 190        const char *const diff_arg  = "-- %s %s||:"; /* "||:" is to return 0 */
 191        const char *input_name_sq[2];
 192        const char *label_path[2];
 193        char *cmd;
 194
 195        /* diff_cmd and diff_arg have 4 %s in total which makes
 196         * the sum of these strings 8 bytes larger than required.
 197         * we use 2 spaces around diff-opts, and we need to count
 198         * terminating NUL; we used to subtract 5 here, but we do not
 199         * care about small leaks in this subprocess that is about
 200         * to exec "diff" anymore.
 201         */
 202        cmd_size = (strlen(diff_cmd) + strlen(diff_opts) + strlen(diff_arg)
 203                    + 128);
 204
 205        for (i = 0; i < 2; i++) {
 206                input_name_sq[i] = sq_quote(temp[i].name);
 207                if (!strcmp(temp[i].name, "/dev/null"))
 208                        label_path[i] = "/dev/null";
 209                else if (!i)
 210                        label_path[i] = sq_quote(quote_two("a/", name_a));
 211                else
 212                        label_path[i] = sq_quote(quote_two("b/", name_b));
 213                cmd_size += (strlen(label_path[i]) + strlen(input_name_sq[i]));
 214        }
 215
 216        cmd = xmalloc(cmd_size);
 217
 218        next_at = 0;
 219        next_at += snprintf(cmd+next_at, cmd_size-next_at,
 220                            diff_cmd, label_path[0], label_path[1]);
 221        next_at += snprintf(cmd+next_at, cmd_size-next_at,
 222                            " %s ", diff_opts);
 223        next_at += snprintf(cmd+next_at, cmd_size-next_at,
 224                            diff_arg, input_name_sq[0], input_name_sq[1]);
 225
 226        printf("diff --git %s %s\n",
 227               quote_two("a/", name_a), quote_two("b/", name_b));
 228        if (label_path[0][0] == '/') {
 229                /* dev/null */
 230                printf("new file mode %s\n", temp[1].mode);
 231                if (xfrm_msg && xfrm_msg[0])
 232                        puts(xfrm_msg);
 233        }
 234        else if (label_path[1][0] == '/') {
 235                printf("deleted file mode %s\n", temp[0].mode);
 236                if (xfrm_msg && xfrm_msg[0])
 237                        puts(xfrm_msg);
 238        }
 239        else {
 240                if (strcmp(temp[0].mode, temp[1].mode)) {
 241                        printf("old mode %s\n", temp[0].mode);
 242                        printf("new mode %s\n", temp[1].mode);
 243                }
 244                if (xfrm_msg && xfrm_msg[0])
 245                        puts(xfrm_msg);
 246                /*
 247                 * we do not run diff between different kind
 248                 * of objects.
 249                 */
 250                if (strncmp(temp[0].mode, temp[1].mode, 3))
 251                        return NULL;
 252                if (complete_rewrite) {
 253                        emit_rewrite_diff(name_a, name_b, temp);
 254                        return NULL;
 255                }
 256        }
 257
 258        /* This is disgusting */
 259        *args++ = "sh";
 260        *args++ = "-c";
 261        *args++ = cmd;
 262        *args = NULL;
 263        return "/bin/sh";
 264}
 265
 266struct diff_filespec *alloc_filespec(const char *path)
 267{
 268        int namelen = strlen(path);
 269        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 270
 271        memset(spec, 0, sizeof(*spec));
 272        spec->path = (char *)(spec + 1);
 273        memcpy(spec->path, path, namelen+1);
 274        return spec;
 275}
 276
 277void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 278                   unsigned short mode)
 279{
 280        if (mode) {
 281                spec->mode = DIFF_FILE_CANON_MODE(mode);
 282                memcpy(spec->sha1, sha1, 20);
 283                spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 284        }
 285}
 286
 287/*
 288 * Given a name and sha1 pair, if the dircache tells us the file in
 289 * the work tree has that object contents, return true, so that
 290 * prepare_temp_file() does not have to inflate and extract.
 291 */
 292static int work_tree_matches(const char *name, const unsigned char *sha1)
 293{
 294        struct cache_entry *ce;
 295        struct stat st;
 296        int pos, len;
 297
 298        /* We do not read the cache ourselves here, because the
 299         * benchmark with my previous version that always reads cache
 300         * shows that it makes things worse for diff-tree comparing
 301         * two linux-2.6 kernel trees in an already checked out work
 302         * tree.  This is because most diff-tree comparisons deal with
 303         * only a small number of files, while reading the cache is
 304         * expensive for a large project, and its cost outweighs the
 305         * savings we get by not inflating the object to a temporary
 306         * file.  Practically, this code only helps when we are used
 307         * by diff-cache --cached, which does read the cache before
 308         * calling us.
 309         */
 310        if (!active_cache)
 311                return 0;
 312
 313        len = strlen(name);
 314        pos = cache_name_pos(name, len);
 315        if (pos < 0)
 316                return 0;
 317        ce = active_cache[pos];
 318        if ((lstat(name, &st) < 0) ||
 319            !S_ISREG(st.st_mode) || /* careful! */
 320            ce_match_stat(ce, &st, 0) ||
 321            memcmp(sha1, ce->sha1, 20))
 322                return 0;
 323        /* we return 1 only when we can stat, it is a regular file,
 324         * stat information matches, and sha1 recorded in the cache
 325         * matches.  I.e. we know the file in the work tree really is
 326         * the same as the <name, sha1> pair.
 327         */
 328        return 1;
 329}
 330
 331static struct sha1_size_cache {
 332        unsigned char sha1[20];
 333        unsigned long size;
 334} **sha1_size_cache;
 335static int sha1_size_cache_nr, sha1_size_cache_alloc;
 336
 337static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 338                                                 int find_only,
 339                                                 unsigned long size)
 340{
 341        int first, last;
 342        struct sha1_size_cache *e;
 343
 344        first = 0;
 345        last = sha1_size_cache_nr;
 346        while (last > first) {
 347                int cmp, next = (last + first) >> 1;
 348                e = sha1_size_cache[next];
 349                cmp = memcmp(e->sha1, sha1, 20);
 350                if (!cmp)
 351                        return e;
 352                if (cmp < 0) {
 353                        last = next;
 354                        continue;
 355                }
 356                first = next+1;
 357        }
 358        /* not found */
 359        if (find_only)
 360                return NULL;
 361        /* insert to make it at "first" */
 362        if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 363                sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 364                sha1_size_cache = xrealloc(sha1_size_cache,
 365                                           sha1_size_cache_alloc *
 366                                           sizeof(*sha1_size_cache));
 367        }
 368        sha1_size_cache_nr++;
 369        if (first < sha1_size_cache_nr)
 370                memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 371                        (sha1_size_cache_nr - first - 1) *
 372                        sizeof(*sha1_size_cache));
 373        e = xmalloc(sizeof(struct sha1_size_cache));
 374        sha1_size_cache[first] = e;
 375        memcpy(e->sha1, sha1, 20);
 376        e->size = size;
 377        return e;
 378}
 379
 380/*
 381 * While doing rename detection and pickaxe operation, we may need to
 382 * grab the data for the blob (or file) for our own in-core comparison.
 383 * diff_filespec has data and size fields for this purpose.
 384 */
 385int diff_populate_filespec(struct diff_filespec *s, int size_only)
 386{
 387        int err = 0;
 388        if (!DIFF_FILE_VALID(s))
 389                die("internal error: asking to populate invalid file.");
 390        if (S_ISDIR(s->mode))
 391                return -1;
 392
 393        if (!use_size_cache)
 394                size_only = 0;
 395
 396        if (s->data)
 397                return err;
 398        if (!s->sha1_valid ||
 399            work_tree_matches(s->path, s->sha1)) {
 400                struct stat st;
 401                int fd;
 402                if (lstat(s->path, &st) < 0) {
 403                        if (errno == ENOENT) {
 404                        err_empty:
 405                                err = -1;
 406                        empty:
 407                                s->data = "";
 408                                s->size = 0;
 409                                return err;
 410                        }
 411                }
 412                s->size = st.st_size;
 413                if (!s->size)
 414                        goto empty;
 415                if (size_only)
 416                        return 0;
 417                if (S_ISLNK(st.st_mode)) {
 418                        int ret;
 419                        s->data = xmalloc(s->size);
 420                        s->should_free = 1;
 421                        ret = readlink(s->path, s->data, s->size);
 422                        if (ret < 0) {
 423                                free(s->data);
 424                                goto err_empty;
 425                        }
 426                        return 0;
 427                }
 428                fd = open(s->path, O_RDONLY);
 429                if (fd < 0)
 430                        goto err_empty;
 431                s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 432                close(fd);
 433                if (s->data == MAP_FAILED)
 434                        goto err_empty;
 435                s->should_munmap = 1;
 436        }
 437        else {
 438                char type[20];
 439                struct sha1_size_cache *e;
 440
 441                if (size_only) {
 442                        e = locate_size_cache(s->sha1, 1, 0);
 443                        if (e) {
 444                                s->size = e->size;
 445                                return 0;
 446                        }
 447                        if (!sha1_object_info(s->sha1, type, &s->size))
 448                                locate_size_cache(s->sha1, 0, s->size);
 449                }
 450                else {
 451                        s->data = read_sha1_file(s->sha1, type, &s->size);
 452                        s->should_free = 1;
 453                }
 454        }
 455        return 0;
 456}
 457
 458void diff_free_filespec_data(struct diff_filespec *s)
 459{
 460        if (s->should_free)
 461                free(s->data);
 462        else if (s->should_munmap)
 463                munmap(s->data, s->size);
 464        s->should_free = s->should_munmap = 0;
 465        s->data = NULL;
 466}
 467
 468static void prep_temp_blob(struct diff_tempfile *temp,
 469                           void *blob,
 470                           unsigned long size,
 471                           const unsigned char *sha1,
 472                           int mode)
 473{
 474        int fd;
 475
 476        fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
 477        if (fd < 0)
 478                die("unable to create temp-file");
 479        if (write(fd, blob, size) != size)
 480                die("unable to write temp-file");
 481        close(fd);
 482        temp->name = temp->tmp_path;
 483        strcpy(temp->hex, sha1_to_hex(sha1));
 484        temp->hex[40] = 0;
 485        sprintf(temp->mode, "%06o", mode);
 486}
 487
 488static void prepare_temp_file(const char *name,
 489                              struct diff_tempfile *temp,
 490                              struct diff_filespec *one)
 491{
 492        if (!DIFF_FILE_VALID(one)) {
 493        not_a_valid_file:
 494                /* A '-' entry produces this for file-2, and
 495                 * a '+' entry produces this for file-1.
 496                 */
 497                temp->name = "/dev/null";
 498                strcpy(temp->hex, ".");
 499                strcpy(temp->mode, ".");
 500                return;
 501        }
 502
 503        if (!one->sha1_valid ||
 504            work_tree_matches(name, one->sha1)) {
 505                struct stat st;
 506                if (lstat(name, &st) < 0) {
 507                        if (errno == ENOENT)
 508                                goto not_a_valid_file;
 509                        die("stat(%s): %s", name, strerror(errno));
 510                }
 511                if (S_ISLNK(st.st_mode)) {
 512                        int ret;
 513                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
 514                        if (sizeof(buf) <= st.st_size)
 515                                die("symlink too long: %s", name);
 516                        ret = readlink(name, buf, st.st_size);
 517                        if (ret < 0)
 518                                die("readlink(%s)", name);
 519                        prep_temp_blob(temp, buf, st.st_size,
 520                                       (one->sha1_valid ?
 521                                        one->sha1 : null_sha1),
 522                                       (one->sha1_valid ?
 523                                        one->mode : S_IFLNK));
 524                }
 525                else {
 526                        /* we can borrow from the file in the work tree */
 527                        temp->name = name;
 528                        if (!one->sha1_valid)
 529                                strcpy(temp->hex, sha1_to_hex(null_sha1));
 530                        else
 531                                strcpy(temp->hex, sha1_to_hex(one->sha1));
 532                        /* Even though we may sometimes borrow the
 533                         * contents from the work tree, we always want
 534                         * one->mode.  mode is trustworthy even when
 535                         * !(one->sha1_valid), as long as
 536                         * DIFF_FILE_VALID(one).
 537                         */
 538                        sprintf(temp->mode, "%06o", one->mode);
 539                }
 540                return;
 541        }
 542        else {
 543                if (diff_populate_filespec(one, 0))
 544                        die("cannot read data blob for %s", one->path);
 545                prep_temp_blob(temp, one->data, one->size,
 546                               one->sha1, one->mode);
 547        }
 548}
 549
 550static void remove_tempfile(void)
 551{
 552        int i;
 553
 554        for (i = 0; i < 2; i++)
 555                if (diff_temp[i].name == diff_temp[i].tmp_path) {
 556                        unlink(diff_temp[i].name);
 557                        diff_temp[i].name = NULL;
 558                }
 559}
 560
 561static void remove_tempfile_on_signal(int signo)
 562{
 563        remove_tempfile();
 564        signal(SIGINT, SIG_DFL);
 565        raise(signo);
 566}
 567
 568static int spawn_prog(const char *pgm, const char **arg)
 569{
 570        pid_t pid;
 571        int status;
 572
 573        fflush(NULL);
 574        pid = fork();
 575        if (pid < 0)
 576                die("unable to fork");
 577        if (!pid) {
 578                execvp(pgm, (char *const*) arg);
 579                exit(255);
 580        }
 581
 582        while (waitpid(pid, &status, 0) < 0) {
 583                if (errno == EINTR)
 584                        continue;
 585                return -1;
 586        }
 587
 588        /* Earlier we did not check the exit status because
 589         * diff exits non-zero if files are different, and
 590         * we are not interested in knowing that.  It was a
 591         * mistake which made it harder to quit a diff-*
 592         * session that uses the git-apply-patch-script as
 593         * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 594         * should also exit non-zero only when it wants to
 595         * abort the entire diff-* session.
 596         */
 597        if (WIFEXITED(status) && !WEXITSTATUS(status))
 598                return 0;
 599        return -1;
 600}
 601
 602/* An external diff command takes:
 603 *
 604 * diff-cmd name infile1 infile1-sha1 infile1-mode \
 605 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 606 *
 607 */
 608static void run_external_diff(const char *pgm,
 609                              const char *name,
 610                              const char *other,
 611                              struct diff_filespec *one,
 612                              struct diff_filespec *two,
 613                              const char *xfrm_msg,
 614                              int complete_rewrite)
 615{
 616        const char *spawn_arg[10];
 617        struct diff_tempfile *temp = diff_temp;
 618        int retval;
 619        static int atexit_asked = 0;
 620        const char *othername;
 621
 622        othername = (other? other : name);
 623        if (one && two) {
 624                prepare_temp_file(name, &temp[0], one);
 625                prepare_temp_file(othername, &temp[1], two);
 626                if (! atexit_asked &&
 627                    (temp[0].name == temp[0].tmp_path ||
 628                     temp[1].name == temp[1].tmp_path)) {
 629                        atexit_asked = 1;
 630                        atexit(remove_tempfile);
 631                }
 632                signal(SIGINT, remove_tempfile_on_signal);
 633        }
 634
 635        if (pgm) {
 636                const char **arg = &spawn_arg[0];
 637                if (one && two) {
 638                        *arg++ = pgm;
 639                        *arg++ = name;
 640                        *arg++ = temp[0].name;
 641                        *arg++ = temp[0].hex;
 642                        *arg++ = temp[0].mode;
 643                        *arg++ = temp[1].name;
 644                        *arg++ = temp[1].hex;
 645                        *arg++ = temp[1].mode;
 646                        if (other) {
 647                                *arg++ = other;
 648                                *arg++ = xfrm_msg;
 649                        }
 650                } else {
 651                        *arg++ = pgm;
 652                        *arg++ = name;
 653                }
 654                *arg = NULL;
 655        } else {
 656                if (one && two) {
 657                        pgm = builtin_diff(name, othername, temp, xfrm_msg, complete_rewrite, spawn_arg);
 658                } else
 659                        printf("* Unmerged path %s\n", name);
 660        }
 661
 662        retval = 0;
 663        if (pgm)
 664                retval = spawn_prog(pgm, spawn_arg);
 665        remove_tempfile();
 666        if (retval) {
 667                fprintf(stderr, "external diff died, stopping at %s.\n", name);
 668                exit(1);
 669        }
 670}
 671
 672static void diff_fill_sha1_info(struct diff_filespec *one)
 673{
 674        if (DIFF_FILE_VALID(one)) {
 675                if (!one->sha1_valid) {
 676                        struct stat st;
 677                        if (lstat(one->path, &st) < 0)
 678                                die("stat %s", one->path);
 679                        if (index_path(one->sha1, one->path, &st, 0))
 680                                die("cannot hash %s\n", one->path);
 681                }
 682        }
 683        else
 684                memset(one->sha1, 0, 20);
 685}
 686
 687static void run_diff(struct diff_filepair *p, struct diff_options *o)
 688{
 689        const char *pgm = external_diff();
 690        char msg[PATH_MAX*2+300], *xfrm_msg;
 691        struct diff_filespec *one;
 692        struct diff_filespec *two;
 693        const char *name;
 694        const char *other;
 695        char *name_munged, *other_munged;
 696        int complete_rewrite = 0;
 697        int len;
 698
 699        if (DIFF_PAIR_UNMERGED(p)) {
 700                /* unmerged */
 701                run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
 702                                  0);
 703                return;
 704        }
 705
 706        name = p->one->path;
 707        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 708        name_munged = quote_one(name);
 709        other_munged = quote_one(other);
 710        one = p->one; two = p->two;
 711
 712        diff_fill_sha1_info(one);
 713        diff_fill_sha1_info(two);
 714
 715        len = 0;
 716        switch (p->status) {
 717        case DIFF_STATUS_COPIED:
 718                len += snprintf(msg + len, sizeof(msg) - len,
 719                                "similarity index %d%%\n"
 720                                "copy from %s\n"
 721                                "copy to %s\n",
 722                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
 723                                name_munged, other_munged);
 724                break;
 725        case DIFF_STATUS_RENAMED:
 726                len += snprintf(msg + len, sizeof(msg) - len,
 727                                "similarity index %d%%\n"
 728                                "rename from %s\n"
 729                                "rename to %s\n",
 730                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
 731                                name_munged, other_munged);
 732                break;
 733        case DIFF_STATUS_MODIFIED:
 734                if (p->score) {
 735                        len += snprintf(msg + len, sizeof(msg) - len,
 736                                        "dissimilarity index %d%%\n",
 737                                        (int)(0.5 + p->score *
 738                                              100.0/MAX_SCORE));
 739                        complete_rewrite = 1;
 740                        break;
 741                }
 742                /* fallthru */
 743        default:
 744                /* nothing */
 745                ;
 746        }
 747
 748        if (memcmp(one->sha1, two->sha1, 20)) {
 749                char one_sha1[41];
 750                int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
 751                memcpy(one_sha1, sha1_to_hex(one->sha1), 41);
 752
 753                len += snprintf(msg + len, sizeof(msg) - len,
 754                                "index %.*s..%.*s",
 755                                abbrev, one_sha1, abbrev,
 756                                sha1_to_hex(two->sha1));
 757                if (one->mode == two->mode)
 758                        len += snprintf(msg + len, sizeof(msg) - len,
 759                                        " %06o", one->mode);
 760                len += snprintf(msg + len, sizeof(msg) - len, "\n");
 761        }
 762
 763        if (len)
 764                msg[--len] = 0;
 765        xfrm_msg = len ? msg : NULL;
 766
 767        if (!pgm &&
 768            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
 769            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
 770                /* a filepair that changes between file and symlink
 771                 * needs to be split into deletion and creation.
 772                 */
 773                struct diff_filespec *null = alloc_filespec(two->path);
 774                run_external_diff(NULL, name, other, one, null, xfrm_msg, 0);
 775                free(null);
 776                null = alloc_filespec(one->path);
 777                run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
 778                free(null);
 779        }
 780        else
 781                run_external_diff(pgm, name, other, one, two, xfrm_msg,
 782                                  complete_rewrite);
 783
 784        free(name_munged);
 785        free(other_munged);
 786}
 787
 788void diff_setup(struct diff_options *options)
 789{
 790        memset(options, 0, sizeof(*options));
 791        options->output_format = DIFF_FORMAT_RAW;
 792        options->line_termination = '\n';
 793        options->break_opt = -1;
 794        options->rename_limit = -1;
 795
 796        options->change = diff_change;
 797        options->add_remove = diff_addremove;
 798}
 799
 800int diff_setup_done(struct diff_options *options)
 801{
 802        if ((options->find_copies_harder &&
 803             options->detect_rename != DIFF_DETECT_COPY) ||
 804            (0 <= options->rename_limit && !options->detect_rename))
 805                return -1;
 806        if (options->detect_rename && options->rename_limit < 0)
 807                options->rename_limit = diff_rename_limit_default;
 808        if (options->setup & DIFF_SETUP_USE_CACHE) {
 809                if (!active_cache)
 810                        /* read-cache does not die even when it fails
 811                         * so it is safe for us to do this here.  Also
 812                         * it does not smudge active_cache or active_nr
 813                         * when it fails, so we do not have to worry about
 814                         * cleaning it up ourselves either.
 815                         */
 816                        read_cache();
 817        }
 818        if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
 819                use_size_cache = 1;
 820        if (options->abbrev <= 0 || 40 < options->abbrev)
 821                options->abbrev = 40; /* full */
 822
 823        return 0;
 824}
 825
 826int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 827{
 828        const char *arg = av[0];
 829        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
 830                options->output_format = DIFF_FORMAT_PATCH;
 831        else if (!strcmp(arg, "-z"))
 832                options->line_termination = 0;
 833        else if (!strncmp(arg, "-l", 2))
 834                options->rename_limit = strtoul(arg+2, NULL, 10);
 835        else if (!strcmp(arg, "--full-index"))
 836                options->full_index = 1;
 837        else if (!strcmp(arg, "--name-only"))
 838                options->output_format = DIFF_FORMAT_NAME;
 839        else if (!strcmp(arg, "--name-status"))
 840                options->output_format = DIFF_FORMAT_NAME_STATUS;
 841        else if (!strcmp(arg, "-R"))
 842                options->reverse_diff = 1;
 843        else if (!strncmp(arg, "-S", 2))
 844                options->pickaxe = arg + 2;
 845        else if (!strcmp(arg, "-s"))
 846                options->output_format = DIFF_FORMAT_NO_OUTPUT;
 847        else if (!strncmp(arg, "-O", 2))
 848                options->orderfile = arg + 2;
 849        else if (!strncmp(arg, "--diff-filter=", 14))
 850                options->filter = arg + 14;
 851        else if (!strcmp(arg, "--pickaxe-all"))
 852                options->pickaxe_opts = DIFF_PICKAXE_ALL;
 853        else if (!strncmp(arg, "-B", 2)) {
 854                if ((options->break_opt =
 855                     diff_scoreopt_parse(arg)) == -1)
 856                        return -1;
 857        }
 858        else if (!strncmp(arg, "-M", 2)) {
 859                if ((options->rename_score =
 860                     diff_scoreopt_parse(arg)) == -1)
 861                        return -1;
 862                options->detect_rename = DIFF_DETECT_RENAME;
 863        }
 864        else if (!strncmp(arg, "-C", 2)) {
 865                if ((options->rename_score =
 866                     diff_scoreopt_parse(arg)) == -1)
 867                        return -1;
 868                options->detect_rename = DIFF_DETECT_COPY;
 869        }
 870        else if (!strcmp(arg, "--find-copies-harder"))
 871                options->find_copies_harder = 1;
 872        else if (!strcmp(arg, "--abbrev"))
 873                options->abbrev = DEFAULT_ABBREV;
 874        else if (!strncmp(arg, "--abbrev=", 9)) {
 875                options->abbrev = strtoul(arg + 9, NULL, 10);
 876                if (options->abbrev < MINIMUM_ABBREV)
 877                        options->abbrev = MINIMUM_ABBREV;
 878                else if (40 < options->abbrev)
 879                        options->abbrev = 40;
 880        }
 881        else
 882                return 0;
 883        return 1;
 884}
 885
 886static int parse_num(const char **cp_p)
 887{
 888        unsigned long num, scale;
 889        int ch, dot;
 890        const char *cp = *cp_p;
 891
 892        num = 0;
 893        scale = 1;
 894        dot = 0;
 895        for(;;) {
 896                ch = *cp;
 897                if ( !dot && ch == '.' ) {
 898                        scale = 1;
 899                        dot = 1;
 900                } else if ( ch == '%' ) {
 901                        scale = dot ? scale*100 : 100;
 902                        cp++;   /* % is always at the end */
 903                        break;
 904                } else if ( ch >= '0' && ch <= '9' ) {
 905                        if ( scale < 100000 ) {
 906                                scale *= 10;
 907                                num = (num*10) + (ch-'0');
 908                        }
 909                } else {
 910                        break;
 911                }
 912                cp++;
 913        }
 914        *cp_p = cp;
 915
 916        /* user says num divided by scale and we say internally that
 917         * is MAX_SCORE * num / scale.
 918         */
 919        return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
 920}
 921
 922int diff_scoreopt_parse(const char *opt)
 923{
 924        int opt1, opt2, cmd;
 925
 926        if (*opt++ != '-')
 927                return -1;
 928        cmd = *opt++;
 929        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
 930                return -1; /* that is not a -M, -C nor -B option */
 931
 932        opt1 = parse_num(&opt);
 933        if (cmd != 'B')
 934                opt2 = 0;
 935        else {
 936                if (*opt == 0)
 937                        opt2 = 0;
 938                else if (*opt != '/')
 939                        return -1; /* we expect -B80/99 or -B80 */
 940                else {
 941                        opt++;
 942                        opt2 = parse_num(&opt);
 943                }
 944        }
 945        if (*opt != 0)
 946                return -1;
 947        return opt1 | (opt2 << 16);
 948}
 949
 950struct diff_queue_struct diff_queued_diff;
 951
 952void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
 953{
 954        if (queue->alloc <= queue->nr) {
 955                queue->alloc = alloc_nr(queue->alloc);
 956                queue->queue = xrealloc(queue->queue,
 957                                        sizeof(dp) * queue->alloc);
 958        }
 959        queue->queue[queue->nr++] = dp;
 960}
 961
 962struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
 963                                 struct diff_filespec *one,
 964                                 struct diff_filespec *two)
 965{
 966        struct diff_filepair *dp = xmalloc(sizeof(*dp));
 967        dp->one = one;
 968        dp->two = two;
 969        dp->score = 0;
 970        dp->status = 0;
 971        dp->source_stays = 0;
 972        dp->broken_pair = 0;
 973        if (queue)
 974                diff_q(queue, dp);
 975        return dp;
 976}
 977
 978void diff_free_filepair(struct diff_filepair *p)
 979{
 980        diff_free_filespec_data(p->one);
 981        diff_free_filespec_data(p->two);
 982        free(p->one);
 983        free(p->two);
 984        free(p);
 985}
 986
 987/* This is different from find_unique_abbrev() in that
 988 * it stuffs the result with dots for alignment.
 989 */
 990const char *diff_unique_abbrev(const unsigned char *sha1, int len)
 991{
 992        int abblen;
 993        const char *abbrev;
 994        if (len == 40)
 995                return sha1_to_hex(sha1);
 996
 997        abbrev = find_unique_abbrev(sha1, len);
 998        if (!abbrev)
 999                return sha1_to_hex(sha1);
1000        abblen = strlen(abbrev);
1001        if (abblen < 37) {
1002                static char hex[41];
1003                if (len < abblen && abblen <= len + 2)
1004                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1005                else
1006                        sprintf(hex, "%s...", abbrev);
1007                return hex;
1008        }
1009        return sha1_to_hex(sha1);
1010}
1011
1012static void diff_flush_raw(struct diff_filepair *p,
1013                           int line_termination,
1014                           int inter_name_termination,
1015                           struct diff_options *options)
1016{
1017        int two_paths;
1018        char status[10];
1019        int abbrev = options->abbrev;
1020        const char *path_one, *path_two;
1021        int output_format = options->output_format;
1022
1023        path_one = p->one->path;
1024        path_two = p->two->path;
1025        if (line_termination) {
1026                path_one = quote_one(path_one);
1027                path_two = quote_one(path_two);
1028        }
1029
1030        if (p->score)
1031                sprintf(status, "%c%03d", p->status,
1032                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
1033        else {
1034                status[0] = p->status;
1035                status[1] = 0;
1036        }
1037        switch (p->status) {
1038        case DIFF_STATUS_COPIED:
1039        case DIFF_STATUS_RENAMED:
1040                two_paths = 1;
1041                break;
1042        case DIFF_STATUS_ADDED:
1043        case DIFF_STATUS_DELETED:
1044                two_paths = 0;
1045                break;
1046        default:
1047                two_paths = 0;
1048                break;
1049        }
1050        if (output_format != DIFF_FORMAT_NAME_STATUS) {
1051                printf(":%06o %06o %s ",
1052                       p->one->mode, p->two->mode,
1053                       diff_unique_abbrev(p->one->sha1, abbrev));
1054                printf("%s ",
1055                       diff_unique_abbrev(p->two->sha1, abbrev));
1056        }
1057        printf("%s%c%s", status, inter_name_termination, path_one);
1058        if (two_paths)
1059                printf("%c%s", inter_name_termination, path_two);
1060        putchar(line_termination);
1061        if (path_one != p->one->path)
1062                free((void*)path_one);
1063        if (path_two != p->two->path)
1064                free((void*)path_two);
1065}
1066
1067static void diff_flush_name(struct diff_filepair *p,
1068                            int inter_name_termination,
1069                            int line_termination)
1070{
1071        char *path = p->two->path;
1072
1073        if (line_termination)
1074                path = quote_one(p->two->path);
1075        else
1076                path = p->two->path;
1077        printf("%s%c", path, line_termination);
1078        if (p->two->path != path)
1079                free(path);
1080}
1081
1082int diff_unmodified_pair(struct diff_filepair *p)
1083{
1084        /* This function is written stricter than necessary to support
1085         * the currently implemented transformers, but the idea is to
1086         * let transformers to produce diff_filepairs any way they want,
1087         * and filter and clean them up here before producing the output.
1088         */
1089        struct diff_filespec *one, *two;
1090
1091        if (DIFF_PAIR_UNMERGED(p))
1092                return 0; /* unmerged is interesting */
1093
1094        one = p->one;
1095        two = p->two;
1096
1097        /* deletion, addition, mode or type change
1098         * and rename are all interesting.
1099         */
1100        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1101            DIFF_PAIR_MODE_CHANGED(p) ||
1102            strcmp(one->path, two->path))
1103                return 0;
1104
1105        /* both are valid and point at the same path.  that is, we are
1106         * dealing with a change.
1107         */
1108        if (one->sha1_valid && two->sha1_valid &&
1109            !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1110                return 1; /* no change */
1111        if (!one->sha1_valid && !two->sha1_valid)
1112                return 1; /* both look at the same file on the filesystem. */
1113        return 0;
1114}
1115
1116static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1117{
1118        if (diff_unmodified_pair(p))
1119                return;
1120
1121        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1122            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1123                return; /* no tree diffs in patch format */ 
1124
1125        run_diff(p, o);
1126}
1127
1128int diff_queue_is_empty(void)
1129{
1130        struct diff_queue_struct *q = &diff_queued_diff;
1131        int i;
1132        for (i = 0; i < q->nr; i++)
1133                if (!diff_unmodified_pair(q->queue[i]))
1134                        return 0;
1135        return 1;
1136}
1137
1138#if DIFF_DEBUG
1139void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1140{
1141        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1142                x, one ? one : "",
1143                s->path,
1144                DIFF_FILE_VALID(s) ? "valid" : "invalid",
1145                s->mode,
1146                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1147        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1148                x, one ? one : "",
1149                s->size, s->xfrm_flags);
1150}
1151
1152void diff_debug_filepair(const struct diff_filepair *p, int i)
1153{
1154        diff_debug_filespec(p->one, i, "one");
1155        diff_debug_filespec(p->two, i, "two");
1156        fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1157                p->score, p->status ? p->status : '?',
1158                p->source_stays, p->broken_pair);
1159}
1160
1161void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1162{
1163        int i;
1164        if (msg)
1165                fprintf(stderr, "%s\n", msg);
1166        fprintf(stderr, "q->nr = %d\n", q->nr);
1167        for (i = 0; i < q->nr; i++) {
1168                struct diff_filepair *p = q->queue[i];
1169                diff_debug_filepair(p, i);
1170        }
1171}
1172#endif
1173
1174static void diff_resolve_rename_copy(void)
1175{
1176        int i, j;
1177        struct diff_filepair *p, *pp;
1178        struct diff_queue_struct *q = &diff_queued_diff;
1179
1180        diff_debug_queue("resolve-rename-copy", q);
1181
1182        for (i = 0; i < q->nr; i++) {
1183                p = q->queue[i];
1184                p->status = 0; /* undecided */
1185                if (DIFF_PAIR_UNMERGED(p))
1186                        p->status = DIFF_STATUS_UNMERGED;
1187                else if (!DIFF_FILE_VALID(p->one))
1188                        p->status = DIFF_STATUS_ADDED;
1189                else if (!DIFF_FILE_VALID(p->two))
1190                        p->status = DIFF_STATUS_DELETED;
1191                else if (DIFF_PAIR_TYPE_CHANGED(p))
1192                        p->status = DIFF_STATUS_TYPE_CHANGED;
1193
1194                /* from this point on, we are dealing with a pair
1195                 * whose both sides are valid and of the same type, i.e.
1196                 * either in-place edit or rename/copy edit.
1197                 */
1198                else if (DIFF_PAIR_RENAME(p)) {
1199                        if (p->source_stays) {
1200                                p->status = DIFF_STATUS_COPIED;
1201                                continue;
1202                        }
1203                        /* See if there is some other filepair that
1204                         * copies from the same source as us.  If so
1205                         * we are a copy.  Otherwise we are either a
1206                         * copy if the path stays, or a rename if it
1207                         * does not, but we already handled "stays" case.
1208                         */
1209                        for (j = i + 1; j < q->nr; j++) {
1210                                pp = q->queue[j];
1211                                if (strcmp(pp->one->path, p->one->path))
1212                                        continue; /* not us */
1213                                if (!DIFF_PAIR_RENAME(pp))
1214                                        continue; /* not a rename/copy */
1215                                /* pp is a rename/copy from the same source */
1216                                p->status = DIFF_STATUS_COPIED;
1217                                break;
1218                        }
1219                        if (!p->status)
1220                                p->status = DIFF_STATUS_RENAMED;
1221                }
1222                else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1223                         p->one->mode != p->two->mode)
1224                        p->status = DIFF_STATUS_MODIFIED;
1225                else {
1226                        /* This is a "no-change" entry and should not
1227                         * happen anymore, but prepare for broken callers.
1228                         */
1229                        error("feeding unmodified %s to diffcore",
1230                              p->one->path);
1231                        p->status = DIFF_STATUS_UNKNOWN;
1232                }
1233        }
1234        diff_debug_queue("resolve-rename-copy done", q);
1235}
1236
1237void diff_flush(struct diff_options *options)
1238{
1239        struct diff_queue_struct *q = &diff_queued_diff;
1240        int i;
1241        int inter_name_termination = '\t';
1242        int diff_output_format = options->output_format;
1243        int line_termination = options->line_termination;
1244
1245        if (!line_termination)
1246                inter_name_termination = 0;
1247
1248        for (i = 0; i < q->nr; i++) {
1249                struct diff_filepair *p = q->queue[i];
1250                if ((diff_output_format == DIFF_FORMAT_NO_OUTPUT) ||
1251                    (p->status == DIFF_STATUS_UNKNOWN))
1252                        continue;
1253                if (p->status == 0)
1254                        die("internal error in diff-resolve-rename-copy");
1255                switch (diff_output_format) {
1256                case DIFF_FORMAT_PATCH:
1257                        diff_flush_patch(p, options);
1258                        break;
1259                case DIFF_FORMAT_RAW:
1260                case DIFF_FORMAT_NAME_STATUS:
1261                        diff_flush_raw(p, line_termination,
1262                                       inter_name_termination,
1263                                       options);
1264                        break;
1265                case DIFF_FORMAT_NAME:
1266                        diff_flush_name(p,
1267                                        inter_name_termination,
1268                                        line_termination);
1269                        break;
1270                }
1271                diff_free_filepair(q->queue[i]);
1272        }
1273        free(q->queue);
1274        q->queue = NULL;
1275        q->nr = q->alloc = 0;
1276}
1277
1278static void diffcore_apply_filter(const char *filter)
1279{
1280        int i;
1281        struct diff_queue_struct *q = &diff_queued_diff;
1282        struct diff_queue_struct outq;
1283        outq.queue = NULL;
1284        outq.nr = outq.alloc = 0;
1285
1286        if (!filter)
1287                return;
1288
1289        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1290                int found;
1291                for (i = found = 0; !found && i < q->nr; i++) {
1292                        struct diff_filepair *p = q->queue[i];
1293                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1294                             ((p->score &&
1295                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1296                              (!p->score &&
1297                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1298                            ((p->status != DIFF_STATUS_MODIFIED) &&
1299                             strchr(filter, p->status)))
1300                                found++;
1301                }
1302                if (found)
1303                        return;
1304
1305                /* otherwise we will clear the whole queue
1306                 * by copying the empty outq at the end of this
1307                 * function, but first clear the current entries
1308                 * in the queue.
1309                 */
1310                for (i = 0; i < q->nr; i++)
1311                        diff_free_filepair(q->queue[i]);
1312        }
1313        else {
1314                /* Only the matching ones */
1315                for (i = 0; i < q->nr; i++) {
1316                        struct diff_filepair *p = q->queue[i];
1317
1318                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1319                             ((p->score &&
1320                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1321                              (!p->score &&
1322                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1323                            ((p->status != DIFF_STATUS_MODIFIED) &&
1324                             strchr(filter, p->status)))
1325                                diff_q(&outq, p);
1326                        else
1327                                diff_free_filepair(p);
1328                }
1329        }
1330        free(q->queue);
1331        *q = outq;
1332}
1333
1334void diffcore_std(struct diff_options *options)
1335{
1336        if (options->paths && options->paths[0])
1337                diffcore_pathspec(options->paths);
1338        if (options->break_opt != -1)
1339                diffcore_break(options->break_opt);
1340        if (options->detect_rename)
1341                diffcore_rename(options);
1342        if (options->break_opt != -1)
1343                diffcore_merge_broken();
1344        if (options->pickaxe)
1345                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1346        if (options->orderfile)
1347                diffcore_order(options->orderfile);
1348        diff_resolve_rename_copy();
1349        diffcore_apply_filter(options->filter);
1350}
1351
1352
1353void diffcore_std_no_resolve(struct diff_options *options)
1354{
1355        if (options->pickaxe)
1356                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1357        if (options->orderfile)
1358                diffcore_order(options->orderfile);
1359        diffcore_apply_filter(options->filter);
1360}
1361
1362void diff_addremove(struct diff_options *options,
1363                    int addremove, unsigned mode,
1364                    const unsigned char *sha1,
1365                    const char *base, const char *path)
1366{
1367        char concatpath[PATH_MAX];
1368        struct diff_filespec *one, *two;
1369
1370        /* This may look odd, but it is a preparation for
1371         * feeding "there are unchanged files which should
1372         * not produce diffs, but when you are doing copy
1373         * detection you would need them, so here they are"
1374         * entries to the diff-core.  They will be prefixed
1375         * with something like '=' or '*' (I haven't decided
1376         * which but should not make any difference).
1377         * Feeding the same new and old to diff_change() 
1378         * also has the same effect.
1379         * Before the final output happens, they are pruned after
1380         * merged into rename/copy pairs as appropriate.
1381         */
1382        if (options->reverse_diff)
1383                addremove = (addremove == '+' ? '-' :
1384                             addremove == '-' ? '+' : addremove);
1385
1386        if (!path) path = "";
1387        sprintf(concatpath, "%s%s", base, path);
1388        one = alloc_filespec(concatpath);
1389        two = alloc_filespec(concatpath);
1390
1391        if (addremove != '+')
1392                fill_filespec(one, sha1, mode);
1393        if (addremove != '-')
1394                fill_filespec(two, sha1, mode);
1395
1396        diff_queue(&diff_queued_diff, one, two);
1397}
1398
1399void diff_change(struct diff_options *options,
1400                 unsigned old_mode, unsigned new_mode,
1401                 const unsigned char *old_sha1,
1402                 const unsigned char *new_sha1,
1403                 const char *base, const char *path) 
1404{
1405        char concatpath[PATH_MAX];
1406        struct diff_filespec *one, *two;
1407
1408        if (options->reverse_diff) {
1409                unsigned tmp;
1410                const unsigned char *tmp_c;
1411                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1412                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1413        }
1414        if (!path) path = "";
1415        sprintf(concatpath, "%s%s", base, path);
1416        one = alloc_filespec(concatpath);
1417        two = alloc_filespec(concatpath);
1418        fill_filespec(one, old_sha1, old_mode);
1419        fill_filespec(two, new_sha1, new_mode);
1420
1421        diff_queue(&diff_queued_diff, one, two);
1422}
1423
1424void diff_unmerge(struct diff_options *options,
1425                  const char *path)
1426{
1427        struct diff_filespec *one, *two;
1428        one = alloc_filespec(path);
1429        two = alloc_filespec(path);
1430        diff_queue(&diff_queued_diff, one, two);
1431}