worktree.c

   1 #include "cache.h"
   2 #include "repository.h"
   3 #include "refs.h"
   4 #include "strbuf.h"
   5 #include "worktree.h"
   6 #include "dir.h"
   7 #include "wt-status.h"
   8
   9 void free_worktrees(struct worktree **worktrees)
  10 {
  11         int i = 0;
  12
  13         for (i = 0; worktrees[i]; i++) {
  14                 free(worktrees[i]->path);
  15                 free(worktrees[i]->id);
  16                 free(worktrees[i]->head_ref);
  17                 free(worktrees[i]->lock_reason);
  18                 free(worktrees[i]);
  19         }
  20         free (worktrees);
  21 }
  22
  23 /**
  24  * Update head_oid, head_ref and is_detached of the given worktree
  25  */
  26 static void add_head_info(struct worktree *wt)
  27 {
  28         int flags;
  29         const char *target;
  30
  31         target = refs_resolve_ref_unsafe(get_worktree_ref_store(wt),
  32                                          "HEAD",
  33                                          0,
  34                                          &wt->head_oid, &flags);
  35         if (!target)
  36                 return;
  37
  38         if (flags & REF_ISSYMREF)
  39                 wt->head_ref = xstrdup(target);
  40         else
  41                 wt->is_detached = 1;
  42 }
  43
  44 /**
  45  * get the main worktree
  46  */
  47 static struct worktree *get_main_worktree(void)
  48 {
  49         struct worktree *worktree = NULL;
  50         struct strbuf worktree_path = STRBUF_INIT;
  51
  52         strbuf_add_real_path(&worktree_path, get_git_common_dir());
  53         strbuf_strip_suffix(&worktree_path, "/.git");
  54
  55         worktree = xcalloc(1, sizeof(*worktree));
  56         worktree->path = strbuf_detach(&worktree_path, NULL);
  57         /*
  58          * NEEDSWORK: If this function is called from a secondary worktree and
  59          * config.worktree is present, is_bare_repository_cfg will reflect the
  60          * contents of config.worktree, not the contents of the main worktree.
  61          * This means that worktree->is_bare may be set to 0 even if the main
  62          * worktree is configured to be bare.
  63          */
  64         worktree->is_bare = (is_bare_repository_cfg == 1) ||
  65                 is_bare_repository();
  66         add_head_info(worktree);
  67         return worktree;
  68 }
  69
  70 static struct worktree *get_linked_worktree(const char *id)
  71 {
  72         struct worktree *worktree = NULL;
  73         struct strbuf path = STRBUF_INIT;
  74         struct strbuf worktree_path = STRBUF_INIT;
  75
  76         if (!id)
  77                 die("Missing linked worktree name");
  78
  79         strbuf_git_common_path(&path, the_repository, "worktrees/%s/gitdir", id);
  80         if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
  81                 /* invalid gitdir file */
  82                 goto done;
  83         strbuf_rtrim(&worktree_path);
  84         strbuf_strip_suffix(&worktree_path, "/.git");
  85
  86         worktree = xcalloc(1, sizeof(*worktree));
  87         worktree->path = strbuf_detach(&worktree_path, NULL);
  88         worktree->id = xstrdup(id);
  89         add_head_info(worktree);
  90
  91 done:
  92         strbuf_release(&path);
  93         strbuf_release(&worktree_path);
  94         return worktree;
  95 }
  96
  97 static void mark_current_worktree(struct worktree **worktrees)
  98 {
  99         char *git_dir = absolute_pathdup(get_git_dir());
 100         int i;
 101
 102         for (i = 0; worktrees[i]; i++) {
 103                 struct worktree *wt = worktrees[i];
 104                 const char *wt_git_dir = get_worktree_git_dir(wt);
 105
 106                 if (!fspathcmp(git_dir, absolute_path(wt_git_dir))) {
 107                         wt->is_current = 1;
 108                         break;
 109                 }
 110         }
 111         free(git_dir);
 112 }
 113
 114 struct worktree **get_worktrees(void)
 115 {
 116         struct worktree **list = NULL;
 117         struct strbuf path = STRBUF_INIT;
 118         DIR *dir;
 119         struct dirent *d;
 120         int counter = 0, alloc = 2;
 121
 122         ALLOC_ARRAY(list, alloc);
 123
 124         list[counter++] = get_main_worktree();
 125
 126         strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
 127         dir = opendir(path.buf);
 128         strbuf_release(&path);
 129         if (dir) {
 130                 while ((d = readdir(dir)) != NULL) {
 131                         struct worktree *linked = NULL;
 132                         if (is_dot_or_dotdot(d->d_name))
 133                                 continue;
 134
 135                         if ((linked = get_linked_worktree(d->d_name))) {
 136                                 ALLOC_GROW(list, counter + 1, alloc);
 137                                 list[counter++] = linked;
 138                         }
 139                 }
 140                 closedir(dir);
 141         }
 142         ALLOC_GROW(list, counter + 1, alloc);
 143         list[counter] = NULL;
 144
 145         mark_current_worktree(list);
 146         return list;
 147 }
 148
 149 const char *get_worktree_git_dir(const struct worktree *wt)
 150 {
 151         if (!wt)
 152                 return get_git_dir();
 153         else if (!wt->id)
 154                 return get_git_common_dir();
 155         else
 156                 return git_common_path("worktrees/%s", wt->id);
 157 }
 158
 159 static struct worktree *find_worktree_by_suffix(struct worktree **list,
 160                                                 const char *suffix)
 161 {
 162         struct worktree *found = NULL;
 163         int nr_found = 0, suffixlen;
 164
 165         suffixlen = strlen(suffix);
 166         if (!suffixlen)
 167                 return NULL;
 168
 169         for (; *list && nr_found < 2; list++) {
 170                 const char      *path    = (*list)->path;
 171                 int              pathlen = strlen(path);
 172                 int              start   = pathlen - suffixlen;
 173
 174                 /* suffix must start at directory boundary */
 175                 if ((!start || (start > 0 && is_dir_sep(path[start - 1]))) &&
 176                     !fspathcmp(suffix, path + start)) {
 177                         found = *list;
 178                         nr_found++;
 179                 }
 180         }
 181         return nr_found == 1 ? found : NULL;
 182 }
 183
 184 struct worktree *find_worktree(struct worktree **list,
 185                                const char *prefix,
 186                                const char *arg)
 187 {
 188         struct worktree *wt;
 189         char *to_free = NULL;
 190
 191         if ((wt = find_worktree_by_suffix(list, arg)))
 192                 return wt;
 193
 194         if (prefix)
 195                 arg = to_free = prefix_filename(prefix, arg);
 196         wt = find_worktree_by_path(list, arg);
 197         free(to_free);
 198         return wt;
 199 }
 200
 201 struct worktree *find_worktree_by_path(struct worktree **list, const char *p)
 202 {
 203         struct strbuf wt_path = STRBUF_INIT;
 204         char *path = real_pathdup(p, 0);
 205
 206         if (!path)
 207                 return NULL;
 208         for (; *list; list++) {
 209                 if (!strbuf_realpath(&wt_path, (*list)->path, 0))
 210                         continue;
 211
 212                 if (!fspathcmp(path, wt_path.buf))
 213                         break;
 214         }
 215         free(path);
 216         strbuf_release(&wt_path);
 217         return *list;
 218 }
 219
 220 int is_main_worktree(const struct worktree *wt)
 221 {
 222         return !wt->id;
 223 }
 224
 225 const char *worktree_lock_reason(struct worktree *wt)
 226 {
 227         assert(!is_main_worktree(wt));
 228
 229         if (!wt->lock_reason_valid) {
 230                 struct strbuf path = STRBUF_INIT;
 231
 232                 strbuf_addstr(&path, worktree_git_path(wt, "locked"));
 233                 if (file_exists(path.buf)) {
 234                         struct strbuf lock_reason = STRBUF_INIT;
 235                         if (strbuf_read_file(&lock_reason, path.buf, 0) < 0)
 236                                 die_errno(_("failed to read '%s'"), path.buf);
 237                         strbuf_trim(&lock_reason);
 238                         wt->lock_reason = strbuf_detach(&lock_reason, NULL);
 239                 } else
 240                         wt->lock_reason = NULL;
 241                 wt->lock_reason_valid = 1;
 242                 strbuf_release(&path);
 243         }
 244
 245         return wt->lock_reason;
 246 }
 247
 248 /* convenient wrapper to deal with NULL strbuf */
 249 static void strbuf_addf_gently(struct strbuf *buf, const char *fmt, ...)
 250 {
 251         va_list params;
 252
 253         if (!buf)
 254                 return;
 255
 256         va_start(params, fmt);
 257         strbuf_vaddf(buf, fmt, params);
 258         va_end(params);
 259 }
 260
 261 int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
 262                       unsigned flags)
 263 {
 264         struct strbuf wt_path = STRBUF_INIT;
 265         struct strbuf realpath = STRBUF_INIT;
 266         char *path = NULL;
 267         int err, ret = -1;
 268
 269         strbuf_addf(&wt_path, "%s/.git", wt->path);
 270
 271         if (is_main_worktree(wt)) {
 272                 if (is_directory(wt_path.buf)) {
 273                         ret = 0;
 274                         goto done;
 275                 }
 276                 /*
 277                  * Main worktree using .git file to point to the
 278                  * repository would make it impossible to know where
 279                  * the actual worktree is if this function is executed
 280                  * from another worktree. No .git file support for now.
 281                  */
 282                 strbuf_addf_gently(errmsg,
 283                                    _("'%s' at main working tree is not the repository directory"),
 284                                    wt_path.buf);
 285                 goto done;
 286         }
 287
 288         /*
 289          * Make sure "gitdir" file points to a real .git file and that
 290          * file points back here.
 291          */
 292         if (!is_absolute_path(wt->path)) {
 293                 strbuf_addf_gently(errmsg,
 294                                    _("'%s' file does not contain absolute path to the working tree location"),
 295                                    git_common_path("worktrees/%s/gitdir", wt->id));
 296                 goto done;
 297         }
 298
 299         if (flags & WT_VALIDATE_WORKTREE_MISSING_OK &&
 300             !file_exists(wt->path)) {
 301                 ret = 0;
 302                 goto done;
 303         }
 304
 305         if (!file_exists(wt_path.buf)) {
 306                 strbuf_addf_gently(errmsg, _("'%s' does not exist"), wt_path.buf);
 307                 goto done;
 308         }
 309
 310         path = xstrdup_or_null(read_gitfile_gently(wt_path.buf, &err));
 311         if (!path) {
 312                 strbuf_addf_gently(errmsg, _("'%s' is not a .git file, error code %d"),
 313                                    wt_path.buf, err);
 314                 goto done;
 315         }
 316
 317         strbuf_realpath(&realpath, git_common_path("worktrees/%s", wt->id), 1);
 318         ret = fspathcmp(path, realpath.buf);
 319
 320         if (ret)
 321                 strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
 322                                    wt->path, git_common_path("worktrees/%s", wt->id));
 323 done:
 324         free(path);
 325         strbuf_release(&wt_path);
 326         strbuf_release(&realpath);
 327         return ret;
 328 }
 329
 330 void update_worktree_location(struct worktree *wt, const char *path_)
 331 {
 332         struct strbuf path = STRBUF_INIT;
 333
 334         if (is_main_worktree(wt))
 335                 BUG("can't relocate main worktree");
 336
 337         strbuf_realpath(&path, path_, 1);
 338         if (fspathcmp(wt->path, path.buf)) {
 339                 write_file(git_common_path("worktrees/%s/gitdir", wt->id),
 340                            "%s/.git", path.buf);
 341                 free(wt->path);
 342                 wt->path = strbuf_detach(&path, NULL);
 343         }
 344         strbuf_release(&path);
 345 }
 346
 347 int is_worktree_being_rebased(const struct worktree *wt,
 348                               const char *target)
 349 {
 350         struct wt_status_state state;
 351         int found_rebase;
 352
 353         memset(&state, 0, sizeof(state));
 354         found_rebase = wt_status_check_rebase(wt, &state) &&
 355                        (state.rebase_in_progress ||
 356                         state.rebase_interactive_in_progress) &&
 357                        state.branch &&
 358                        skip_prefix(target, "refs/heads/", &target) &&
 359                        !strcmp(state.branch, target);
 360         wt_status_state_free_buffers(&state);
 361         return found_rebase;
 362 }
 363
 364 int is_worktree_being_bisected(const struct worktree *wt,
 365                                const char *target)
 366 {
 367         struct wt_status_state state;
 368         int found_bisect;
 369
 370         memset(&state, 0, sizeof(state));
 371         found_bisect = wt_status_check_bisect(wt, &state) &&
 372                        state.branch &&
 373                        skip_prefix(target, "refs/heads/", &target) &&
 374                        !strcmp(state.branch, target);
 375         wt_status_state_free_buffers(&state);
 376         return found_bisect;
 377 }
 378
 379 /*
 380  * note: this function should be able to detect shared symref even if
 381  * HEAD is temporarily detached (e.g. in the middle of rebase or
 382  * bisect). New commands that do similar things should update this
 383  * function as well.
 384  */
 385 const struct worktree *find_shared_symref(const char *symref,
 386                                           const char *target)
 387 {
 388         const struct worktree *existing = NULL;
 389         static struct worktree **worktrees;
 390         int i = 0;
 391
 392         if (worktrees)
 393                 free_worktrees(worktrees);
 394         worktrees = get_worktrees();
 395
 396         for (i = 0; worktrees[i]; i++) {
 397                 struct worktree *wt = worktrees[i];
 398                 const char *symref_target;
 399                 struct ref_store *refs;
 400                 int flags;
 401
 402                 if (wt->is_bare)
 403                         continue;
 404
 405                 if (wt->is_detached && !strcmp(symref, "HEAD")) {
 406                         if (is_worktree_being_rebased(wt, target)) {
 407                                 existing = wt;
 408                                 break;
 409                         }
 410                         if (is_worktree_being_bisected(wt, target)) {
 411                                 existing = wt;
 412                                 break;
 413                         }
 414                 }
 415
 416                 refs = get_worktree_ref_store(wt);
 417                 symref_target = refs_resolve_ref_unsafe(refs, symref, 0,
 418                                                         NULL, &flags);
 419                 if ((flags & REF_ISSYMREF) &&
 420                     symref_target && !strcmp(symref_target, target)) {
 421                         existing = wt;
 422                         break;
 423                 }
 424         }
 425
 426         return existing;
 427 }
 428
 429 int submodule_uses_worktrees(const char *path)
 430 {
 431         char *submodule_gitdir;
 432         struct strbuf sb = STRBUF_INIT, err = STRBUF_INIT;
 433         DIR *dir;
 434         struct dirent *d;
 435         int ret = 0;
 436         struct repository_format format = REPOSITORY_FORMAT_INIT;
 437
 438         submodule_gitdir = git_pathdup_submodule(path, "%s", "");
 439         if (!submodule_gitdir)
 440                 return 0;
 441
 442         /* The env would be set for the superproject. */
 443         get_common_dir_noenv(&sb, submodule_gitdir);
 444         free(submodule_gitdir);
 445
 446         strbuf_addstr(&sb, "/config");
 447         read_repository_format(&format, sb.buf);
 448         if (verify_repository_format(&format, &err)) {
 449                 strbuf_release(&err);
 450                 strbuf_release(&sb);
 451                 clear_repository_format(&format);
 452                 return 1;
 453         }
 454         clear_repository_format(&format);
 455         strbuf_release(&err);
 456
 457         /* Replace config by worktrees. */
 458         strbuf_setlen(&sb, sb.len - strlen("config"));
 459         strbuf_addstr(&sb, "worktrees");
 460
 461         /* See if there is any file inside the worktrees directory. */
 462         dir = opendir(sb.buf);
 463         strbuf_release(&sb);
 464
 465         if (!dir)
 466                 return 0;
 467
 468         while ((d = readdir(dir)) != NULL) {
 469                 if (is_dot_or_dotdot(d->d_name))
 470                         continue;
 471
 472                 ret = 1;
 473                 break;
 474         }
 475         closedir(dir);
 476         return ret;
 477 }
 478
 479 int parse_worktree_ref(const char *worktree_ref, const char **name,
 480                        int *name_length, const char **ref)
 481 {
 482         if (skip_prefix(worktree_ref, "main-worktree/", &worktree_ref)) {
 483                 if (!*worktree_ref)
 484                         return -1;
 485                 if (name)
 486                         *name = NULL;
 487                 if (name_length)
 488                         *name_length = 0;
 489                 if (ref)
 490                         *ref = worktree_ref;
 491                 return 0;
 492         }
 493         if (skip_prefix(worktree_ref, "worktrees/", &worktree_ref)) {
 494                 const char *slash = strchr(worktree_ref, '/');
 495
 496                 if (!slash || slash == worktree_ref || !slash[1])
 497                         return -1;
 498                 if (name)
 499                         *name = worktree_ref;
 500                 if (name_length)
 501                         *name_length = slash - worktree_ref;
 502                 if (ref)
 503                         *ref = slash + 1;
 504                 return 0;
 505         }
 506         return -1;
 507 }
 508
 509 void strbuf_worktree_ref(const struct worktree *wt,
 510                          struct strbuf *sb,
 511                          const char *refname)
 512 {
 513         switch (ref_type(refname)) {
 514         case REF_TYPE_PSEUDOREF:
 515         case REF_TYPE_PER_WORKTREE:
 516                 if (wt && !wt->is_current) {
 517                         if (is_main_worktree(wt))
 518                                 strbuf_addstr(sb, "main-worktree/");
 519                         else
 520                                 strbuf_addf(sb, "worktrees/%s/", wt->id);
 521                 }
 522                 break;
 523
 524         case REF_TYPE_MAIN_PSEUDOREF:
 525         case REF_TYPE_OTHER_PSEUDOREF:
 526                 break;
 527
 528         case REF_TYPE_NORMAL:
 529                 /*
 530                  * For shared refs, don't prefix worktrees/ or
 531                  * main-worktree/. It's not necessary and
 532                  * files-backend.c can't handle it anyway.
 533                  */
 534                 break;
 535         }
 536         strbuf_addstr(sb, refname);
 537 }
 538
 539 int other_head_refs(each_ref_fn fn, void *cb_data)
 540 {
 541         struct worktree **worktrees, **p;
 542         struct strbuf refname = STRBUF_INIT;
 543         int ret = 0;
 544
 545         worktrees = get_worktrees();
 546         for (p = worktrees; *p; p++) {
 547                 struct worktree *wt = *p;
 548                 struct object_id oid;
 549                 int flag;
 550
 551                 if (wt->is_current)
 552                         continue;
 553
 554                 strbuf_reset(&refname);
 555                 strbuf_worktree_ref(wt, &refname, "HEAD");
 556                 if (!refs_read_ref_full(get_main_ref_store(the_repository),
 557                                         refname.buf,
 558                                         RESOLVE_REF_READING,
 559                                         &oid, &flag))
 560                         ret = fn(refname.buf, &oid, flag, cb_data);
 561                 if (ret)
 562                         break;
 563         }
 564         free_worktrees(worktrees);
 565         strbuf_release(&refname);
 566         return ret;
 567 }
 568
 569 /*
 570  * Repair worktree's /path/to/worktree/.git file if missing, corrupt, or not
 571  * pointing at <repo>/worktrees/<id>.
 572  */
 573 static void repair_gitfile(struct worktree *wt,
 574                            worktree_repair_fn fn, void *cb_data)
 575 {
 576         struct strbuf dotgit = STRBUF_INIT;
 577         struct strbuf repo = STRBUF_INIT;
 578         char *backlink;
 579         const char *repair = NULL;
 580         int err;
 581
 582         /* missing worktree can't be repaired */
 583         if (!file_exists(wt->path))
 584                 return;
 585
 586         if (!is_directory(wt->path)) {
 587                 fn(1, wt->path, _("not a directory"), cb_data);
 588                 return;
 589         }
 590
 591         strbuf_realpath(&repo, git_common_path("worktrees/%s", wt->id), 1);
 592         strbuf_addf(&dotgit, "%s/.git", wt->path);
 593         backlink = xstrdup_or_null(read_gitfile_gently(dotgit.buf, &err));
 594
 595         if (err == READ_GITFILE_ERR_NOT_A_FILE)
 596                 fn(1, wt->path, _(".git is not a file"), cb_data);
 597         else if (err)
 598                 repair = _(".git file broken");
 599         else if (fspathcmp(backlink, repo.buf))
 600                 repair = _(".git file incorrect");
 601
 602         if (repair) {
 603                 fn(0, wt->path, repair, cb_data);
 604                 write_file(dotgit.buf, "gitdir: %s", repo.buf);
 605         }
 606
 607         free(backlink);
 608         strbuf_release(&repo);
 609         strbuf_release(&dotgit);
 610 }
 611
 612 static void repair_noop(int iserr, const char *path, const char *msg,
 613                         void *cb_data)
 614 {
 615         /* nothing */
 616 }
 617
 618 void repair_worktrees(worktree_repair_fn fn, void *cb_data)
 619 {
 620         struct worktree **worktrees = get_worktrees();
 621         struct worktree **wt = worktrees + 1; /* +1 skips main worktree */
 622
 623         if (!fn)
 624                 fn = repair_noop;
 625         for (; *wt; wt++)
 626                 repair_gitfile(*wt, fn, cb_data);
 627         free_worktrees(worktrees);
 628 }
 629
 630 static int is_main_worktree_path(const char *path)
 631 {
 632         struct strbuf target = STRBUF_INIT;
 633         struct strbuf maindir = STRBUF_INIT;
 634         int cmp;
 635
 636         strbuf_add_real_path(&target, path);
 637         strbuf_strip_suffix(&target, "/.git");
 638         strbuf_add_real_path(&maindir, get_git_common_dir());
 639         strbuf_strip_suffix(&maindir, "/.git");
 640         cmp = fspathcmp(maindir.buf, target.buf);
 641
 642         strbuf_release(&maindir);
 643         strbuf_release(&target);
 644         return !cmp;
 645 }
 646
 647 /*
 648  * If both the main worktree and linked worktree have been moved, then the
 649  * gitfile /path/to/worktree/.git won't point into the repository, thus we
 650  * won't know which <repo>/worktrees/<id>/gitdir to repair. However, we may
 651  * be able to infer the gitdir by manually reading /path/to/worktree/.git,
 652  * extracting the <id>, and checking if <repo>/worktrees/<id> exists.
 653  */
 654 static char *infer_backlink(const char *gitfile)
 655 {
 656         struct strbuf actual = STRBUF_INIT;
 657         struct strbuf inferred = STRBUF_INIT;
 658         const char *id;
 659
 660         if (strbuf_read_file(&actual, gitfile, 0) < 0)
 661                 goto error;
 662         if (!starts_with(actual.buf, "gitdir:"))
 663                 goto error;
 664         if (!(id = find_last_dir_sep(actual.buf)))
 665                 goto error;
 666         strbuf_trim(&actual);
 667         id++; /* advance past '/' to point at <id> */
 668         if (!*id)
 669                 goto error;
 670         strbuf_git_common_path(&inferred, the_repository, "worktrees/%s", id);
 671         if (!is_directory(inferred.buf))
 672                 goto error;
 673
 674         strbuf_release(&actual);
 675         return strbuf_detach(&inferred, NULL);
 676
 677 error:
 678         strbuf_release(&actual);
 679         strbuf_release(&inferred);
 680         return NULL;
 681 }
 682
 683 /*
 684  * Repair <repo>/worktrees/<id>/gitdir if missing, corrupt, or not pointing at
 685  * the worktree's path.
 686  */
 687 void repair_worktree_at_path(const char *path,
 688                              worktree_repair_fn fn, void *cb_data)
 689 {
 690         struct strbuf dotgit = STRBUF_INIT;
 691         struct strbuf realdotgit = STRBUF_INIT;
 692         struct strbuf gitdir = STRBUF_INIT;
 693         struct strbuf olddotgit = STRBUF_INIT;
 694         char *backlink = NULL;
 695         const char *repair = NULL;
 696         int err;
 697
 698         if (!fn)
 699                 fn = repair_noop;
 700
 701         if (is_main_worktree_path(path))
 702                 goto done;
 703
 704         strbuf_addf(&dotgit, "%s/.git", path);
 705         if (!strbuf_realpath(&realdotgit, dotgit.buf, 0)) {
 706                 fn(1, path, _("not a valid path"), cb_data);
 707                 goto done;
 708         }
 709
 710         backlink = xstrdup_or_null(read_gitfile_gently(realdotgit.buf, &err));
 711         if (err == READ_GITFILE_ERR_NOT_A_FILE) {
 712                 fn(1, realdotgit.buf, _("unable to locate repository; .git is not a file"), cb_data);
 713                 goto done;
 714         } else if (err == READ_GITFILE_ERR_NOT_A_REPO) {
 715                 if (!(backlink = infer_backlink(realdotgit.buf))) {
 716                         fn(1, realdotgit.buf, _("unable to locate repository; .git file does not reference a repository"), cb_data);
 717                         goto done;
 718                 }
 719         } else if (err) {
 720                 fn(1, realdotgit.buf, _("unable to locate repository; .git file broken"), cb_data);
 721                 goto done;
 722         }
 723
 724         strbuf_addf(&gitdir, "%s/gitdir", backlink);
 725         if (strbuf_read_file(&olddotgit, gitdir.buf, 0) < 0)
 726                 repair = _("gitdir unreadable");
 727         else {
 728                 strbuf_rtrim(&olddotgit);
 729                 if (fspathcmp(olddotgit.buf, realdotgit.buf))
 730                         repair = _("gitdir incorrect");
 731         }
 732
 733         if (repair) {
 734                 fn(0, gitdir.buf, repair, cb_data);
 735                 write_file(gitdir.buf, "%s", realdotgit.buf);
 736         }
 737 done:
 738         free(backlink);
 739         strbuf_release(&olddotgit);
 740         strbuf_release(&gitdir);
 741         strbuf_release(&realdotgit);
 742         strbuf_release(&dotgit);
 743 }