diff-lib.con commit fix importing of subversion tars (46f6178)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "commit.h"
   7#include "diff.h"
   8#include "diffcore.h"
   9#include "revision.h"
  10#include "cache-tree.h"
  11#include "path-list.h"
  12
  13/*
  14 * diff-files
  15 */
  16
  17static int read_directory(const char *path, struct path_list *list)
  18{
  19        DIR *dir;
  20        struct dirent *e;
  21
  22        if (!(dir = opendir(path)))
  23                return error("Could not open directory %s", path);
  24
  25        while ((e = readdir(dir)))
  26                if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
  27                        path_list_insert(xstrdup(e->d_name), list);
  28
  29        closedir(dir);
  30        return 0;
  31}
  32
  33static int get_mode(const char *path, int *mode)
  34{
  35        struct stat st;
  36
  37        if (!path || !strcmp(path, "/dev/null"))
  38                *mode = 0;
  39        else if (!strcmp(path, "-"))
  40                *mode = ntohl(create_ce_mode(0666));
  41        else if (stat(path, &st))
  42                return error("Could not access '%s'", path);
  43        else
  44                *mode = st.st_mode;
  45        return 0;
  46}
  47
  48static int queue_diff(struct diff_options *o,
  49                const char *name1, const char *name2)
  50{
  51        int mode1 = 0, mode2 = 0;
  52
  53        if (get_mode(name1, &mode1) || get_mode(name2, &mode2))
  54                return -1;
  55
  56        if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
  57                return error("file/directory conflict: %s, %s", name1, name2);
  58
  59        if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
  60                char buffer1[PATH_MAX], buffer2[PATH_MAX];
  61                struct path_list p1 = {NULL, 0, 0, 1}, p2 = {NULL, 0, 0, 1};
  62                int len1 = 0, len2 = 0, i1, i2, ret = 0;
  63
  64                if (name1 && read_directory(name1, &p1))
  65                        return -1;
  66                if (name2 && read_directory(name2, &p2)) {
  67                        path_list_clear(&p1, 0);
  68                        return -1;
  69                }
  70
  71                if (name1) {
  72                        len1 = strlen(name1);
  73                        if (len1 > 0 && name1[len1 - 1] == '/')
  74                                len1--;
  75                        memcpy(buffer1, name1, len1);
  76                        buffer1[len1++] = '/';
  77                }
  78
  79                if (name2) {
  80                        len2 = strlen(name2);
  81                        if (len2 > 0 && name2[len2 - 1] == '/')
  82                                len2--;
  83                        memcpy(buffer2, name2, len2);
  84                        buffer2[len2++] = '/';
  85                }
  86
  87                for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
  88                        const char *n1, *n2;
  89                        int comp;
  90
  91                        if (i1 == p1.nr)
  92                                comp = 1;
  93                        else if (i2 == p2.nr)
  94                                comp = -1;
  95                        else
  96                                comp = strcmp(p1.items[i1].path,
  97                                        p2.items[i2].path);
  98
  99                        if (comp > 0)
 100                                n1 = NULL;
 101                        else {
 102                                n1 = buffer1;
 103                                strncpy(buffer1 + len1, p1.items[i1++].path,
 104                                                PATH_MAX - len1);
 105                        }
 106
 107                        if (comp < 0)
 108                                n2 = NULL;
 109                        else {
 110                                n2 = buffer2;
 111                                strncpy(buffer2 + len2, p2.items[i2++].path,
 112                                                PATH_MAX - len2);
 113                        }
 114
 115                        ret = queue_diff(o, n1, n2);
 116                }
 117                path_list_clear(&p1, 0);
 118                path_list_clear(&p2, 0);
 119
 120                return ret;
 121        } else {
 122                struct diff_filespec *d1, *d2;
 123
 124                if (o->reverse_diff) {
 125                        unsigned tmp;
 126                        const char *tmp_c;
 127                        tmp = mode1; mode1 = mode2; mode2 = tmp;
 128                        tmp_c = name1; name1 = name2; name2 = tmp_c;
 129                }
 130
 131                if (!name1)
 132                        name1 = "/dev/null";
 133                if (!name2)
 134                        name2 = "/dev/null";
 135                d1 = alloc_filespec(name1);
 136                d2 = alloc_filespec(name2);
 137                fill_filespec(d1, null_sha1, mode1);
 138                fill_filespec(d2, null_sha1, mode2);
 139
 140                diff_queue(&diff_queued_diff, d1, d2);
 141                return 0;
 142        }
 143}
 144
 145/*
 146 * Does the path name a blob in the working tree, or a directory
 147 * in the working tree?
 148 */
 149static int is_in_index(const char *path)
 150{
 151        int len, pos;
 152        struct cache_entry *ce;
 153
 154        len = strlen(path);
 155        while (path[len-1] == '/')
 156                len--;
 157        if (!len)
 158                return 1; /* "." */
 159        pos = cache_name_pos(path, len);
 160        if (0 <= pos)
 161                return 1;
 162        pos = -1 - pos;
 163        while (pos < active_nr) {
 164                ce = active_cache[pos++];
 165                if (ce_namelen(ce) <= len ||
 166                    strncmp(ce->name, path, len) ||
 167                    (ce->name[len] > '/'))
 168                        break; /* path cannot be a prefix */
 169                if (ce->name[len] == '/')
 170                        return 1;
 171        }
 172        return 0;
 173}
 174
 175static int handle_diff_files_args(struct rev_info *revs,
 176                int argc, const char **argv, int *silent)
 177{
 178        *silent = 0;
 179
 180        /* revs->max_count == -2 means --no-index */
 181        while (1 < argc && argv[1][0] == '-') {
 182                if (!strcmp(argv[1], "--base"))
 183                        revs->max_count = 1;
 184                else if (!strcmp(argv[1], "--ours"))
 185                        revs->max_count = 2;
 186                else if (!strcmp(argv[1], "--theirs"))
 187                        revs->max_count = 3;
 188                else if (!strcmp(argv[1], "-n") ||
 189                                !strcmp(argv[1], "--no-index")) {
 190                        revs->max_count = -2;
 191                        revs->diffopt.exit_with_status = 1;
 192                }
 193                else if (!strcmp(argv[1], "-q"))
 194                        *silent = 1;
 195                else
 196                        return error("invalid option: %s", argv[1]);
 197                argv++; argc--;
 198        }
 199
 200        if (revs->max_count == -1 && revs->diffopt.nr_paths == 2) {
 201                /*
 202                 * If two files are specified, and at least one is untracked,
 203                 * default to no-index.
 204                 */
 205                read_cache();
 206                if (!is_in_index(revs->diffopt.paths[0]) ||
 207                                        !is_in_index(revs->diffopt.paths[1]))
 208                        revs->max_count = -2;
 209        }
 210
 211        /*
 212         * Make sure there are NO revision (i.e. pending object) parameter,
 213         * rev.max_count is reasonable (0 <= n <= 3),
 214         * there is no other revision filtering parameters.
 215         */
 216        if (revs->pending.nr || revs->max_count > 3 ||
 217            revs->min_age != -1 || revs->max_age != -1)
 218                return error("no revision allowed with diff-files");
 219
 220        if (revs->max_count == -1 &&
 221            (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 222                revs->combine_merges = revs->dense_combined_merges = 1;
 223
 224        return 0;
 225}
 226
 227static int is_outside_repo(const char *path, int nongit, const char *prefix)
 228{
 229        int i;
 230        if (nongit || !strcmp(path, "-") || path[0] == '/')
 231                return 1;
 232        if (prefixcmp(path, "../"))
 233                return 0;
 234        if (!prefix)
 235                return 1;
 236        for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
 237                while (i > 0 && prefix[i - 1] != '/')
 238                        i--;
 239                if (--i < 0)
 240                        return 1;
 241                path += 3;
 242        }
 243        return 0;
 244}
 245
 246int setup_diff_no_index(struct rev_info *revs,
 247                int argc, const char ** argv, int nongit, const char *prefix)
 248{
 249        int i;
 250        for (i = 1; i < argc; i++)
 251                if (argv[i][0] != '-' || argv[i][1] == '\0')
 252                        break;
 253                else if (!strcmp(argv[i], "--")) {
 254                        i++;
 255                        break;
 256                } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
 257                        i = argc - 3;
 258                        revs->diffopt.exit_with_status = 1;
 259                        break;
 260                }
 261        if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
 262                                !is_outside_repo(argv[i], nongit, prefix)))
 263                return -1;
 264
 265        diff_setup(&revs->diffopt);
 266        for (i = 1; i < argc - 2; )
 267                if (!strcmp(argv[i], "--no-index"))
 268                        i++;
 269                else {
 270                        int j = diff_opt_parse(&revs->diffopt,
 271                                        argv + i, argc - i);
 272                        if (!j)
 273                                die("invalid diff option/value: %s", argv[i]);
 274                        i += j;
 275                }
 276
 277        if (prefix) {
 278                int len = strlen(prefix);
 279
 280                revs->diffopt.paths = xcalloc(2, sizeof(char*));
 281                for (i = 0; i < 2; i++) {
 282                        const char *p = argv[argc - 2 + i];
 283                        /*
 284                         * stdin should be spelled as '-'; if you have
 285                         * path that is '-', spell it as ./-.
 286                         */
 287                        p = (strcmp(p, "-")
 288                             ? xstrdup(prefix_filename(prefix, len, p))
 289                             : p);
 290                        revs->diffopt.paths[i] = p;
 291                }
 292        }
 293        else
 294                revs->diffopt.paths = argv + argc - 2;
 295        revs->diffopt.nr_paths = 2;
 296        revs->max_count = -2;
 297        return 0;
 298}
 299
 300int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
 301{
 302        int silent_on_removed;
 303
 304        if (handle_diff_files_args(revs, argc, argv, &silent_on_removed))
 305                return -1;
 306
 307        if (revs->max_count == -2) {
 308                if (revs->diffopt.nr_paths != 2)
 309                        return error("need two files/directories with --no-index");
 310                if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
 311                                revs->diffopt.paths[1]))
 312                        return -1;
 313                diffcore_std(&revs->diffopt);
 314                diff_flush(&revs->diffopt);
 315                /*
 316                 * The return code for --no-index imitates diff(1):
 317                 * 0 = no changes, 1 = changes, else error
 318                 */
 319                return revs->diffopt.found_changes;
 320        }
 321
 322        if (read_cache() < 0) {
 323                perror("read_cache");
 324                return -1;
 325        }
 326        return run_diff_files(revs, silent_on_removed);
 327}
 328
 329int run_diff_files(struct rev_info *revs, int silent_on_removed)
 330{
 331        int entries, i;
 332        int diff_unmerged_stage = revs->max_count;
 333
 334        if (diff_unmerged_stage < 0)
 335                diff_unmerged_stage = 2;
 336        entries = active_nr;
 337        for (i = 0; i < entries; i++) {
 338                struct stat st;
 339                unsigned int oldmode, newmode;
 340                struct cache_entry *ce = active_cache[i];
 341                int changed;
 342
 343                if (revs->diffopt.quiet && revs->diffopt.has_changes)
 344                        break;
 345
 346                if (!ce_path_match(ce, revs->prune_data))
 347                        continue;
 348
 349                if (ce_stage(ce)) {
 350                        struct combine_diff_path *dpath;
 351                        int num_compare_stages = 0;
 352                        size_t path_len;
 353
 354                        path_len = ce_namelen(ce);
 355
 356                        dpath = xmalloc(combine_diff_path_size(5, path_len));
 357                        dpath->path = (char *) &(dpath->parent[5]);
 358
 359                        dpath->next = NULL;
 360                        dpath->len = path_len;
 361                        memcpy(dpath->path, ce->name, path_len);
 362                        dpath->path[path_len] = '\0';
 363                        hashclr(dpath->sha1);
 364                        memset(&(dpath->parent[0]), 0,
 365                               sizeof(struct combine_diff_parent)*5);
 366
 367                        if (lstat(ce->name, &st) < 0) {
 368                                if (errno != ENOENT && errno != ENOTDIR) {
 369                                        perror(ce->name);
 370                                        continue;
 371                                }
 372                                if (silent_on_removed)
 373                                        continue;
 374                        }
 375                        else
 376                                dpath->mode = canon_mode(st.st_mode);
 377
 378                        while (i < entries) {
 379                                struct cache_entry *nce = active_cache[i];
 380                                int stage;
 381
 382                                if (strcmp(ce->name, nce->name))
 383                                        break;
 384
 385                                /* Stage #2 (ours) is the first parent,
 386                                 * stage #3 (theirs) is the second.
 387                                 */
 388                                stage = ce_stage(nce);
 389                                if (2 <= stage) {
 390                                        int mode = ntohl(nce->ce_mode);
 391                                        num_compare_stages++;
 392                                        hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 393                                        dpath->parent[stage-2].mode =
 394                                                canon_mode(mode);
 395                                        dpath->parent[stage-2].status =
 396                                                DIFF_STATUS_MODIFIED;
 397                                }
 398
 399                                /* diff against the proper unmerged stage */
 400                                if (stage == diff_unmerged_stage)
 401                                        ce = nce;
 402                                i++;
 403                        }
 404                        /*
 405                         * Compensate for loop update
 406                         */
 407                        i--;
 408
 409                        if (revs->combine_merges && num_compare_stages == 2) {
 410                                show_combined_diff(dpath, 2,
 411                                                   revs->dense_combined_merges,
 412                                                   revs);
 413                                free(dpath);
 414                                continue;
 415                        }
 416                        free(dpath);
 417                        dpath = NULL;
 418
 419                        /*
 420                         * Show the diff for the 'ce' if we found the one
 421                         * from the desired stage.
 422                         */
 423                        diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
 424                        if (ce_stage(ce) != diff_unmerged_stage)
 425                                continue;
 426                }
 427
 428                if (lstat(ce->name, &st) < 0) {
 429                        if (errno != ENOENT && errno != ENOTDIR) {
 430                                perror(ce->name);
 431                                continue;
 432                        }
 433                        if (silent_on_removed)
 434                                continue;
 435                        diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
 436                                       ce->sha1, ce->name, NULL);
 437                        continue;
 438                }
 439                changed = ce_match_stat(ce, &st, 0);
 440                if (!changed && !revs->diffopt.find_copies_harder)
 441                        continue;
 442                oldmode = ntohl(ce->ce_mode);
 443
 444                newmode = canon_mode(st.st_mode);
 445                if (!trust_executable_bit &&
 446                    S_ISREG(newmode) && S_ISREG(oldmode) &&
 447                    ((newmode ^ oldmode) == 0111))
 448                        newmode = oldmode;
 449                else if (!has_symlinks &&
 450                    S_ISREG(newmode) && S_ISLNK(oldmode))
 451                        newmode = oldmode;
 452                diff_change(&revs->diffopt, oldmode, newmode,
 453                            ce->sha1, (changed ? null_sha1 : ce->sha1),
 454                            ce->name, NULL);
 455
 456        }
 457        diffcore_std(&revs->diffopt);
 458        diff_flush(&revs->diffopt);
 459        return 0;
 460}
 461
 462/*
 463 * diff-index
 464 */
 465
 466/* A file entry went away or appeared */
 467static void diff_index_show_file(struct rev_info *revs,
 468                                 const char *prefix,
 469                                 struct cache_entry *ce,
 470                                 unsigned char *sha1, unsigned int mode)
 471{
 472        diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
 473                       sha1, ce->name, NULL);
 474}
 475
 476static int get_stat_data(struct cache_entry *ce,
 477                         unsigned char **sha1p,
 478                         unsigned int *modep,
 479                         int cached, int match_missing)
 480{
 481        unsigned char *sha1 = ce->sha1;
 482        unsigned int mode = ce->ce_mode;
 483
 484        if (!cached) {
 485                static unsigned char no_sha1[20];
 486                int changed;
 487                struct stat st;
 488                if (lstat(ce->name, &st) < 0) {
 489                        if (errno == ENOENT && match_missing) {
 490                                *sha1p = sha1;
 491                                *modep = mode;
 492                                return 0;
 493                        }
 494                        return -1;
 495                }
 496                changed = ce_match_stat(ce, &st, 0);
 497                if (changed) {
 498                        mode = ce_mode_from_stat(ce, st.st_mode);
 499                        sha1 = no_sha1;
 500                }
 501        }
 502
 503        *sha1p = sha1;
 504        *modep = mode;
 505        return 0;
 506}
 507
 508static void show_new_file(struct rev_info *revs,
 509                          struct cache_entry *new,
 510                          int cached, int match_missing)
 511{
 512        unsigned char *sha1;
 513        unsigned int mode;
 514
 515        /* New file in the index: it might actually be different in
 516         * the working copy.
 517         */
 518        if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
 519                return;
 520
 521        diff_index_show_file(revs, "+", new, sha1, mode);
 522}
 523
 524static int show_modified(struct rev_info *revs,
 525                         struct cache_entry *old,
 526                         struct cache_entry *new,
 527                         int report_missing,
 528                         int cached, int match_missing)
 529{
 530        unsigned int mode, oldmode;
 531        unsigned char *sha1;
 532
 533        if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
 534                if (report_missing)
 535                        diff_index_show_file(revs, "-", old,
 536                                             old->sha1, old->ce_mode);
 537                return -1;
 538        }
 539
 540        if (revs->combine_merges && !cached &&
 541            (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 542                struct combine_diff_path *p;
 543                int pathlen = ce_namelen(new);
 544
 545                p = xmalloc(combine_diff_path_size(2, pathlen));
 546                p->path = (char *) &p->parent[2];
 547                p->next = NULL;
 548                p->len = pathlen;
 549                memcpy(p->path, new->name, pathlen);
 550                p->path[pathlen] = 0;
 551                p->mode = ntohl(mode);
 552                hashclr(p->sha1);
 553                memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 554                p->parent[0].status = DIFF_STATUS_MODIFIED;
 555                p->parent[0].mode = ntohl(new->ce_mode);
 556                hashcpy(p->parent[0].sha1, new->sha1);
 557                p->parent[1].status = DIFF_STATUS_MODIFIED;
 558                p->parent[1].mode = ntohl(old->ce_mode);
 559                hashcpy(p->parent[1].sha1, old->sha1);
 560                show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 561                free(p);
 562                return 0;
 563        }
 564
 565        oldmode = old->ce_mode;
 566        if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
 567            !revs->diffopt.find_copies_harder)
 568                return 0;
 569
 570        mode = ntohl(mode);
 571        oldmode = ntohl(oldmode);
 572
 573        diff_change(&revs->diffopt, oldmode, mode,
 574                    old->sha1, sha1, old->name, NULL);
 575        return 0;
 576}
 577
 578static int diff_cache(struct rev_info *revs,
 579                      struct cache_entry **ac, int entries,
 580                      const char **pathspec,
 581                      int cached, int match_missing)
 582{
 583        while (entries) {
 584                struct cache_entry *ce = *ac;
 585                int same = (entries > 1) && ce_same_name(ce, ac[1]);
 586
 587                if (revs->diffopt.quiet && revs->diffopt.has_changes)
 588                        break;
 589
 590                if (!ce_path_match(ce, pathspec))
 591                        goto skip_entry;
 592
 593                switch (ce_stage(ce)) {
 594                case 0:
 595                        /* No stage 1 entry? That means it's a new file */
 596                        if (!same) {
 597                                show_new_file(revs, ce, cached, match_missing);
 598                                break;
 599                        }
 600                        /* Show difference between old and new */
 601                        show_modified(revs, ac[1], ce, 1,
 602                                      cached, match_missing);
 603                        break;
 604                case 1:
 605                        /* No stage 3 (merge) entry?
 606                         * That means it's been deleted.
 607                         */
 608                        if (!same) {
 609                                diff_index_show_file(revs, "-", ce,
 610                                                     ce->sha1, ce->ce_mode);
 611                                break;
 612                        }
 613                        /* We come here with ce pointing at stage 1
 614                         * (original tree) and ac[1] pointing at stage
 615                         * 3 (unmerged).  show-modified with
 616                         * report-missing set to false does not say the
 617                         * file is deleted but reports true if work
 618                         * tree does not have it, in which case we
 619                         * fall through to report the unmerged state.
 620                         * Otherwise, we show the differences between
 621                         * the original tree and the work tree.
 622                         */
 623                        if (!cached &&
 624                            !show_modified(revs, ce, ac[1], 0,
 625                                           cached, match_missing))
 626                                break;
 627                        diff_unmerge(&revs->diffopt, ce->name,
 628                                     ntohl(ce->ce_mode), ce->sha1);
 629                        break;
 630                case 3:
 631                        diff_unmerge(&revs->diffopt, ce->name,
 632                                     0, null_sha1);
 633                        break;
 634
 635                default:
 636                        die("impossible cache entry stage");
 637                }
 638
 639skip_entry:
 640                /*
 641                 * Ignore all the different stages for this file,
 642                 * we've handled the relevant cases now.
 643                 */
 644                do {
 645                        ac++;
 646                        entries--;
 647                } while (entries && ce_same_name(ce, ac[0]));
 648        }
 649        return 0;
 650}
 651
 652/*
 653 * This turns all merge entries into "stage 3". That guarantees that
 654 * when we read in the new tree (into "stage 1"), we won't lose sight
 655 * of the fact that we had unmerged entries.
 656 */
 657static void mark_merge_entries(void)
 658{
 659        int i;
 660        for (i = 0; i < active_nr; i++) {
 661                struct cache_entry *ce = active_cache[i];
 662                if (!ce_stage(ce))
 663                        continue;
 664                ce->ce_flags |= htons(CE_STAGEMASK);
 665        }
 666}
 667
 668int run_diff_index(struct rev_info *revs, int cached)
 669{
 670        int ret;
 671        struct object *ent;
 672        struct tree *tree;
 673        const char *tree_name;
 674        int match_missing = 0;
 675
 676        /* 
 677         * Backward compatibility wart - "diff-index -m" does
 678         * not mean "do not ignore merges", but totally different.
 679         */
 680        if (!revs->ignore_merges)
 681                match_missing = 1;
 682
 683        mark_merge_entries();
 684
 685        ent = revs->pending.objects[0].item;
 686        tree_name = revs->pending.objects[0].name;
 687        tree = parse_tree_indirect(ent->sha1);
 688        if (!tree)
 689                return error("bad tree object %s", tree_name);
 690        if (read_tree(tree, 1, revs->prune_data))
 691                return error("unable to read tree object %s", tree_name);
 692        ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
 693                         cached, match_missing);
 694        diffcore_std(&revs->diffopt);
 695        diff_flush(&revs->diffopt);
 696        return ret;
 697}
 698
 699int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 700{
 701        struct tree *tree;
 702        struct rev_info revs;
 703        int i;
 704        struct cache_entry **dst;
 705        struct cache_entry *last = NULL;
 706
 707        /*
 708         * This is used by git-blame to run diff-cache internally;
 709         * it potentially needs to repeatedly run this, so we will
 710         * start by removing the higher order entries the last round
 711         * left behind.
 712         */
 713        dst = active_cache;
 714        for (i = 0; i < active_nr; i++) {
 715                struct cache_entry *ce = active_cache[i];
 716                if (ce_stage(ce)) {
 717                        if (last && !strcmp(ce->name, last->name))
 718                                continue;
 719                        cache_tree_invalidate_path(active_cache_tree,
 720                                                   ce->name);
 721                        last = ce;
 722                        ce->ce_mode = 0;
 723                        ce->ce_flags &= ~htons(CE_STAGEMASK);
 724                }
 725                *dst++ = ce;
 726        }
 727        active_nr = dst - active_cache;
 728
 729        init_revisions(&revs, NULL);
 730        revs.prune_data = opt->paths;
 731        tree = parse_tree_indirect(tree_sha1);
 732        if (!tree)
 733                die("bad tree object %s", sha1_to_hex(tree_sha1));
 734        if (read_tree(tree, 1, opt->paths))
 735                return error("unable to read tree %s", sha1_to_hex(tree_sha1));
 736        return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
 737                          1, 0);
 738}