worktree.c

   1 #include "git-compat-util.h"
   2 #include "abspath.h"
   3 #include "environment.h"
   4 #include "gettext.h"
   5 #include "path.h"
   6 #include "repository.h"
   7 #include "refs.h"
   8 #include "setup.h"
   9 #include "strbuf.h"
  10 #include "worktree.h"
  11 #include "dir.h"
  12 #include "wt-status.h"
  13 #include "config.h"
  14
  15 void free_worktrees(struct worktree **worktrees)
  16 {
  17         int i = 0;
  18
  19         for (i = 0; worktrees[i]; i++) {
  20                 free(worktrees[i]->path);
  21                 free(worktrees[i]->id);
  22                 free(worktrees[i]->head_ref);
  23                 free(worktrees[i]->lock_reason);
  24                 free(worktrees[i]->prune_reason);
  25                 free(worktrees[i]);
  26         }
  27         free (worktrees);
  28 }
  29
  30 /**
  31  * Update head_oid, head_ref and is_detached of the given worktree
  32  */
  33 static void add_head_info(struct worktree *wt)
  34 {
  35         int flags;
  36         const char *target;
  37
  38         target = refs_resolve_ref_unsafe(get_worktree_ref_store(wt),
  39                                          "HEAD",
  40                                          0,
  41                                          &wt->head_oid, &flags);
  42         if (!target)
  43                 return;
  44
  45         if (flags & REF_ISSYMREF)
  46                 wt->head_ref = xstrdup(target);
  47         else
  48                 wt->is_detached = 1;
  49 }
  50
  51 /**
  52  * get the main worktree
  53  */
  54 static struct worktree *get_main_worktree(void)
  55 {
  56         struct worktree *worktree = NULL;
  57         struct strbuf worktree_path = STRBUF_INIT;
  58
  59         strbuf_add_real_path(&worktree_path, get_git_common_dir());
  60         strbuf_strip_suffix(&worktree_path, "/.git");
  61
  62         CALLOC_ARRAY(worktree, 1);
  63         worktree->path = strbuf_detach(&worktree_path, NULL);
  64         /*
  65          * NEEDSWORK: If this function is called from a secondary worktree and
  66          * config.worktree is present, is_bare_repository_cfg will reflect the
  67          * contents of config.worktree, not the contents of the main worktree.
  68          * This means that worktree->is_bare may be set to 0 even if the main
  69          * worktree is configured to be bare.
  70          */
  71         worktree->is_bare = (is_bare_repository_cfg == 1) ||
  72                 is_bare_repository();
  73         add_head_info(worktree);
  74         return worktree;
  75 }
  76
  77 static struct worktree *get_linked_worktree(const char *id)
  78 {
  79         struct worktree *worktree = NULL;
  80         struct strbuf path = STRBUF_INIT;
  81         struct strbuf worktree_path = STRBUF_INIT;
  82
  83         if (!id)
  84                 die("Missing linked worktree name");
  85
  86         strbuf_git_common_path(&path, the_repository, "worktrees/%s/gitdir", id);
  87         if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
  88                 /* invalid gitdir file */
  89                 goto done;
  90         strbuf_rtrim(&worktree_path);
  91         strbuf_strip_suffix(&worktree_path, "/.git");
  92
  93         CALLOC_ARRAY(worktree, 1);
  94         worktree->path = strbuf_detach(&worktree_path, NULL);
  95         worktree->id = xstrdup(id);
  96         add_head_info(worktree);
  97
  98 done:
  99         strbuf_release(&path);
 100         strbuf_release(&worktree_path);
 101         return worktree;
 102 }
 103
 104 static void mark_current_worktree(struct worktree **worktrees)
 105 {
 106         char *git_dir = absolute_pathdup(get_git_dir());
 107         int i;
 108
 109         for (i = 0; worktrees[i]; i++) {
 110                 struct worktree *wt = worktrees[i];
 111                 const char *wt_git_dir = get_worktree_git_dir(wt);
 112
 113                 if (!fspathcmp(git_dir, absolute_path(wt_git_dir))) {
 114                         wt->is_current = 1;
 115                         break;
 116                 }
 117         }
 118         free(git_dir);
 119 }
 120
 121 struct worktree **get_worktrees(void)
 122 {
 123         struct worktree **list = NULL;
 124         struct strbuf path = STRBUF_INIT;
 125         DIR *dir;
 126         struct dirent *d;
 127         int counter = 0, alloc = 2;
 128
 129         ALLOC_ARRAY(list, alloc);
 130
 131         list[counter++] = get_main_worktree();
 132
 133         strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
 134         dir = opendir(path.buf);
 135         strbuf_release(&path);
 136         if (dir) {
 137                 while ((d = readdir_skip_dot_and_dotdot(dir)) != NULL) {
 138                         struct worktree *linked = NULL;
 139
 140                         if ((linked = get_linked_worktree(d->d_name))) {
 141                                 ALLOC_GROW(list, counter + 1, alloc);
 142                                 list[counter++] = linked;
 143                         }
 144                 }
 145                 closedir(dir);
 146         }
 147         ALLOC_GROW(list, counter + 1, alloc);
 148         list[counter] = NULL;
 149
 150         mark_current_worktree(list);
 151         return list;
 152 }
 153
 154 const char *get_worktree_git_dir(const struct worktree *wt)
 155 {
 156         if (!wt)
 157                 return get_git_dir();
 158         else if (!wt->id)
 159                 return get_git_common_dir();
 160         else
 161                 return git_common_path("worktrees/%s", wt->id);
 162 }
 163
 164 static struct worktree *find_worktree_by_suffix(struct worktree **list,
 165                                                 const char *suffix)
 166 {
 167         struct worktree *found = NULL;
 168         int nr_found = 0, suffixlen;
 169
 170         suffixlen = strlen(suffix);
 171         if (!suffixlen)
 172                 return NULL;
 173
 174         for (; *list && nr_found < 2; list++) {
 175                 const char      *path    = (*list)->path;
 176                 int              pathlen = strlen(path);
 177                 int              start   = pathlen - suffixlen;
 178
 179                 /* suffix must start at directory boundary */
 180                 if ((!start || (start > 0 && is_dir_sep(path[start - 1]))) &&
 181                     !fspathcmp(suffix, path + start)) {
 182                         found = *list;
 183                         nr_found++;
 184                 }
 185         }
 186         return nr_found == 1 ? found : NULL;
 187 }
 188
 189 struct worktree *find_worktree(struct worktree **list,
 190                                const char *prefix,
 191                                const char *arg)
 192 {
 193         struct worktree *wt;
 194         char *to_free = NULL;
 195
 196         if ((wt = find_worktree_by_suffix(list, arg)))
 197                 return wt;
 198
 199         if (prefix)
 200                 arg = to_free = prefix_filename(prefix, arg);
 201         wt = find_worktree_by_path(list, arg);
 202         free(to_free);
 203         return wt;
 204 }
 205
 206 struct worktree *find_worktree_by_path(struct worktree **list, const char *p)
 207 {
 208         struct strbuf wt_path = STRBUF_INIT;
 209         char *path = real_pathdup(p, 0);
 210
 211         if (!path)
 212                 return NULL;
 213         for (; *list; list++) {
 214                 if (!strbuf_realpath(&wt_path, (*list)->path, 0))
 215                         continue;
 216
 217                 if (!fspathcmp(path, wt_path.buf))
 218                         break;
 219         }
 220         free(path);
 221         strbuf_release(&wt_path);
 222         return *list;
 223 }
 224
 225 int is_main_worktree(const struct worktree *wt)
 226 {
 227         return !wt->id;
 228 }
 229
 230 const char *worktree_lock_reason(struct worktree *wt)
 231 {
 232         if (is_main_worktree(wt))
 233                 return NULL;
 234
 235         if (!wt->lock_reason_valid) {
 236                 struct strbuf path = STRBUF_INIT;
 237
 238                 strbuf_addstr(&path, worktree_git_path(wt, "locked"));
 239                 if (file_exists(path.buf)) {
 240                         struct strbuf lock_reason = STRBUF_INIT;
 241                         if (strbuf_read_file(&lock_reason, path.buf, 0) < 0)
 242                                 die_errno(_("failed to read '%s'"), path.buf);
 243                         strbuf_trim(&lock_reason);
 244                         wt->lock_reason = strbuf_detach(&lock_reason, NULL);
 245                 } else
 246                         wt->lock_reason = NULL;
 247                 wt->lock_reason_valid = 1;
 248                 strbuf_release(&path);
 249         }
 250
 251         return wt->lock_reason;
 252 }
 253
 254 const char *worktree_prune_reason(struct worktree *wt, timestamp_t expire)
 255 {
 256         struct strbuf reason = STRBUF_INIT;
 257         char *path = NULL;
 258
 259         if (is_main_worktree(wt))
 260                 return NULL;
 261         if (wt->prune_reason_valid)
 262                 return wt->prune_reason;
 263
 264         if (should_prune_worktree(wt->id, &reason, &path, expire))
 265                 wt->prune_reason = strbuf_detach(&reason, NULL);
 266         wt->prune_reason_valid = 1;
 267
 268         strbuf_release(&reason);
 269         free(path);
 270         return wt->prune_reason;
 271 }
 272
 273 /* convenient wrapper to deal with NULL strbuf */
 274 __attribute__((format (printf, 2, 3)))
 275 static void strbuf_addf_gently(struct strbuf *buf, const char *fmt, ...)
 276 {
 277         va_list params;
 278
 279         if (!buf)
 280                 return;
 281
 282         va_start(params, fmt);
 283         strbuf_vaddf(buf, fmt, params);
 284         va_end(params);
 285 }
 286
 287 int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
 288                       unsigned flags)
 289 {
 290         struct strbuf wt_path = STRBUF_INIT;
 291         struct strbuf realpath = STRBUF_INIT;
 292         char *path = NULL;
 293         int err, ret = -1;
 294
 295         strbuf_addf(&wt_path, "%s/.git", wt->path);
 296
 297         if (is_main_worktree(wt)) {
 298                 if (is_directory(wt_path.buf)) {
 299                         ret = 0;
 300                         goto done;
 301                 }
 302                 /*
 303                  * Main worktree using .git file to point to the
 304                  * repository would make it impossible to know where
 305                  * the actual worktree is if this function is executed
 306                  * from another worktree. No .git file support for now.
 307                  */
 308                 strbuf_addf_gently(errmsg,
 309                                    _("'%s' at main working tree is not the repository directory"),
 310                                    wt_path.buf);
 311                 goto done;
 312         }
 313
 314         /*
 315          * Make sure "gitdir" file points to a real .git file and that
 316          * file points back here.
 317          */
 318         if (!is_absolute_path(wt->path)) {
 319                 strbuf_addf_gently(errmsg,
 320                                    _("'%s' file does not contain absolute path to the working tree location"),
 321                                    git_common_path("worktrees/%s/gitdir", wt->id));
 322                 goto done;
 323         }
 324
 325         if (flags & WT_VALIDATE_WORKTREE_MISSING_OK &&
 326             !file_exists(wt->path)) {
 327                 ret = 0;
 328                 goto done;
 329         }
 330
 331         if (!file_exists(wt_path.buf)) {
 332                 strbuf_addf_gently(errmsg, _("'%s' does not exist"), wt_path.buf);
 333                 goto done;
 334         }
 335
 336         path = xstrdup_or_null(read_gitfile_gently(wt_path.buf, &err));
 337         if (!path) {
 338                 strbuf_addf_gently(errmsg, _("'%s' is not a .git file, error code %d"),
 339                                    wt_path.buf, err);
 340                 goto done;
 341         }
 342
 343         strbuf_realpath(&realpath, git_common_path("worktrees/%s", wt->id), 1);
 344         ret = fspathcmp(path, realpath.buf);
 345
 346         if (ret)
 347                 strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
 348                                    wt->path, git_common_path("worktrees/%s", wt->id));
 349 done:
 350         free(path);
 351         strbuf_release(&wt_path);
 352         strbuf_release(&realpath);
 353         return ret;
 354 }
 355
 356 void update_worktree_location(struct worktree *wt, const char *path_)
 357 {
 358         struct strbuf path = STRBUF_INIT;
 359
 360         if (is_main_worktree(wt))
 361                 BUG("can't relocate main worktree");
 362
 363         strbuf_realpath(&path, path_, 1);
 364         if (fspathcmp(wt->path, path.buf)) {
 365                 write_file(git_common_path("worktrees/%s/gitdir", wt->id),
 366                            "%s/.git", path.buf);
 367                 free(wt->path);
 368                 wt->path = strbuf_detach(&path, NULL);
 369         }
 370         strbuf_release(&path);
 371 }
 372
 373 int is_worktree_being_rebased(const struct worktree *wt,
 374                               const char *target)
 375 {
 376         struct wt_status_state state;
 377         int found_rebase;
 378
 379         memset(&state, 0, sizeof(state));
 380         found_rebase = wt_status_check_rebase(wt, &state) &&
 381                        (state.rebase_in_progress ||
 382                         state.rebase_interactive_in_progress) &&
 383                        state.branch &&
 384                        skip_prefix(target, "refs/heads/", &target) &&
 385                        !strcmp(state.branch, target);
 386         wt_status_state_free_buffers(&state);
 387         return found_rebase;
 388 }
 389
 390 int is_worktree_being_bisected(const struct worktree *wt,
 391                                const char *target)
 392 {
 393         struct wt_status_state state;
 394         int found_bisect;
 395
 396         memset(&state, 0, sizeof(state));
 397         found_bisect = wt_status_check_bisect(wt, &state) &&
 398                        state.branch &&
 399                        skip_prefix(target, "refs/heads/", &target) &&
 400                        !strcmp(state.branch, target);
 401         wt_status_state_free_buffers(&state);
 402         return found_bisect;
 403 }
 404
 405 /*
 406  * note: this function should be able to detect shared symref even if
 407  * HEAD is temporarily detached (e.g. in the middle of rebase or
 408  * bisect). New commands that do similar things should update this
 409  * function as well.
 410  */
 411 int is_shared_symref(const struct worktree *wt, const char *symref,
 412                      const char *target)
 413 {
 414         const char *symref_target;
 415         struct ref_store *refs;
 416         int flags;
 417
 418         if (wt->is_bare)
 419                 return 0;
 420
 421         if (wt->is_detached && !strcmp(symref, "HEAD")) {
 422                 if (is_worktree_being_rebased(wt, target))
 423                         return 1;
 424                 if (is_worktree_being_bisected(wt, target))
 425                         return 1;
 426         }
 427
 428         refs = get_worktree_ref_store(wt);
 429         symref_target = refs_resolve_ref_unsafe(refs, symref, 0,
 430                                                 NULL, &flags);
 431         if ((flags & REF_ISSYMREF) &&
 432             symref_target && !strcmp(symref_target, target))
 433                 return 1;
 434
 435         return 0;
 436 }
 437
 438 const struct worktree *find_shared_symref(struct worktree **worktrees,
 439                                           const char *symref,
 440                                           const char *target)
 441 {
 442
 443         for (int i = 0; worktrees[i]; i++)
 444                 if (is_shared_symref(worktrees[i], symref, target))
 445                         return worktrees[i];
 446
 447         return NULL;
 448 }
 449
 450 int submodule_uses_worktrees(const char *path)
 451 {
 452         char *submodule_gitdir;
 453         struct strbuf sb = STRBUF_INIT, err = STRBUF_INIT;
 454         DIR *dir;
 455         struct dirent *d;
 456         int ret = 0;
 457         struct repository_format format = REPOSITORY_FORMAT_INIT;
 458
 459         submodule_gitdir = git_pathdup_submodule(path, "%s", "");
 460         if (!submodule_gitdir)
 461                 return 0;
 462
 463         /* The env would be set for the superproject. */
 464         get_common_dir_noenv(&sb, submodule_gitdir);
 465         free(submodule_gitdir);
 466
 467         strbuf_addstr(&sb, "/config");
 468         read_repository_format(&format, sb.buf);
 469         if (verify_repository_format(&format, &err)) {
 470                 strbuf_release(&err);
 471                 strbuf_release(&sb);
 472                 clear_repository_format(&format);
 473                 return 1;
 474         }
 475         clear_repository_format(&format);
 476         strbuf_release(&err);
 477
 478         /* Replace config by worktrees. */
 479         strbuf_setlen(&sb, sb.len - strlen("config"));
 480         strbuf_addstr(&sb, "worktrees");
 481
 482         /* See if there is any file inside the worktrees directory. */
 483         dir = opendir(sb.buf);
 484         strbuf_release(&sb);
 485
 486         if (!dir)
 487                 return 0;
 488
 489         d = readdir_skip_dot_and_dotdot(dir);
 490         if (d)
 491                 ret = 1;
 492         closedir(dir);
 493         return ret;
 494 }
 495
 496 void strbuf_worktree_ref(const struct worktree *wt,
 497                          struct strbuf *sb,
 498                          const char *refname)
 499 {
 500         if (parse_worktree_ref(refname, NULL, NULL, NULL) ==
 501                     REF_WORKTREE_CURRENT &&
 502             wt && !wt->is_current) {
 503                 if (is_main_worktree(wt))
 504                         strbuf_addstr(sb, "main-worktree/");
 505                 else
 506                         strbuf_addf(sb, "worktrees/%s/", wt->id);
 507         }
 508         strbuf_addstr(sb, refname);
 509 }
 510
 511 int other_head_refs(each_ref_fn fn, void *cb_data)
 512 {
 513         struct worktree **worktrees, **p;
 514         struct strbuf refname = STRBUF_INIT;
 515         int ret = 0;
 516
 517         worktrees = get_worktrees();
 518         for (p = worktrees; *p; p++) {
 519                 struct worktree *wt = *p;
 520                 struct object_id oid;
 521                 int flag;
 522
 523                 if (wt->is_current)
 524                         continue;
 525
 526                 strbuf_reset(&refname);
 527                 strbuf_worktree_ref(wt, &refname, "HEAD");
 528                 if (refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
 529                                             refname.buf,
 530                                             RESOLVE_REF_READING,
 531                                             &oid, &flag))
 532                         ret = fn(refname.buf, &oid, flag, cb_data);
 533                 if (ret)
 534                         break;
 535         }
 536         free_worktrees(worktrees);
 537         strbuf_release(&refname);
 538         return ret;
 539 }
 540
 541 /*
 542  * Repair worktree's /path/to/worktree/.git file if missing, corrupt, or not
 543  * pointing at <repo>/worktrees/<id>.
 544  */
 545 static void repair_gitfile(struct worktree *wt,
 546                            worktree_repair_fn fn, void *cb_data)
 547 {
 548         struct strbuf dotgit = STRBUF_INIT;
 549         struct strbuf repo = STRBUF_INIT;
 550         char *backlink;
 551         const char *repair = NULL;
 552         int err;
 553
 554         /* missing worktree can't be repaired */
 555         if (!file_exists(wt->path))
 556                 return;
 557
 558         if (!is_directory(wt->path)) {
 559                 fn(1, wt->path, _("not a directory"), cb_data);
 560                 return;
 561         }
 562
 563         strbuf_realpath(&repo, git_common_path("worktrees/%s", wt->id), 1);
 564         strbuf_addf(&dotgit, "%s/.git", wt->path);
 565         backlink = xstrdup_or_null(read_gitfile_gently(dotgit.buf, &err));
 566
 567         if (err == READ_GITFILE_ERR_NOT_A_FILE)
 568                 fn(1, wt->path, _(".git is not a file"), cb_data);
 569         else if (err)
 570                 repair = _(".git file broken");
 571         else if (fspathcmp(backlink, repo.buf))
 572                 repair = _(".git file incorrect");
 573
 574         if (repair) {
 575                 fn(0, wt->path, repair, cb_data);
 576                 write_file(dotgit.buf, "gitdir: %s", repo.buf);
 577         }
 578
 579         free(backlink);
 580         strbuf_release(&repo);
 581         strbuf_release(&dotgit);
 582 }
 583
 584 static void repair_noop(int iserr UNUSED,
 585                         const char *path UNUSED,
 586                         const char *msg UNUSED,
 587                         void *cb_data UNUSED)
 588 {
 589         /* nothing */
 590 }
 591
 592 void repair_worktrees(worktree_repair_fn fn, void *cb_data)
 593 {
 594         struct worktree **worktrees = get_worktrees();
 595         struct worktree **wt = worktrees + 1; /* +1 skips main worktree */
 596
 597         if (!fn)
 598                 fn = repair_noop;
 599         for (; *wt; wt++)
 600                 repair_gitfile(*wt, fn, cb_data);
 601         free_worktrees(worktrees);
 602 }
 603
 604 static int is_main_worktree_path(const char *path)
 605 {
 606         struct strbuf target = STRBUF_INIT;
 607         struct strbuf maindir = STRBUF_INIT;
 608         int cmp;
 609
 610         strbuf_add_real_path(&target, path);
 611         strbuf_strip_suffix(&target, "/.git");
 612         strbuf_add_real_path(&maindir, get_git_common_dir());
 613         strbuf_strip_suffix(&maindir, "/.git");
 614         cmp = fspathcmp(maindir.buf, target.buf);
 615
 616         strbuf_release(&maindir);
 617         strbuf_release(&target);
 618         return !cmp;
 619 }
 620
 621 /*
 622  * If both the main worktree and linked worktree have been moved, then the
 623  * gitfile /path/to/worktree/.git won't point into the repository, thus we
 624  * won't know which <repo>/worktrees/<id>/gitdir to repair. However, we may
 625  * be able to infer the gitdir by manually reading /path/to/worktree/.git,
 626  * extracting the <id>, and checking if <repo>/worktrees/<id> exists.
 627  */
 628 static char *infer_backlink(const char *gitfile)
 629 {
 630         struct strbuf actual = STRBUF_INIT;
 631         struct strbuf inferred = STRBUF_INIT;
 632         const char *id;
 633
 634         if (strbuf_read_file(&actual, gitfile, 0) < 0)
 635                 goto error;
 636         if (!starts_with(actual.buf, "gitdir:"))
 637                 goto error;
 638         if (!(id = find_last_dir_sep(actual.buf)))
 639                 goto error;
 640         strbuf_trim(&actual);
 641         id++; /* advance past '/' to point at <id> */
 642         if (!*id)
 643                 goto error;
 644         strbuf_git_common_path(&inferred, the_repository, "worktrees/%s", id);
 645         if (!is_directory(inferred.buf))
 646                 goto error;
 647
 648         strbuf_release(&actual);
 649         return strbuf_detach(&inferred, NULL);
 650
 651 error:
 652         strbuf_release(&actual);
 653         strbuf_release(&inferred);
 654         return NULL;
 655 }
 656
 657 /*
 658  * Repair <repo>/worktrees/<id>/gitdir if missing, corrupt, or not pointing at
 659  * the worktree's path.
 660  */
 661 void repair_worktree_at_path(const char *path,
 662                              worktree_repair_fn fn, void *cb_data)
 663 {
 664         struct strbuf dotgit = STRBUF_INIT;
 665         struct strbuf realdotgit = STRBUF_INIT;
 666         struct strbuf gitdir = STRBUF_INIT;
 667         struct strbuf olddotgit = STRBUF_INIT;
 668         char *backlink = NULL;
 669         const char *repair = NULL;
 670         int err;
 671
 672         if (!fn)
 673                 fn = repair_noop;
 674
 675         if (is_main_worktree_path(path))
 676                 goto done;
 677
 678         strbuf_addf(&dotgit, "%s/.git", path);
 679         if (!strbuf_realpath(&realdotgit, dotgit.buf, 0)) {
 680                 fn(1, path, _("not a valid path"), cb_data);
 681                 goto done;
 682         }
 683
 684         backlink = xstrdup_or_null(read_gitfile_gently(realdotgit.buf, &err));
 685         if (err == READ_GITFILE_ERR_NOT_A_FILE) {
 686                 fn(1, realdotgit.buf, _("unable to locate repository; .git is not a file"), cb_data);
 687                 goto done;
 688         } else if (err == READ_GITFILE_ERR_NOT_A_REPO) {
 689                 if (!(backlink = infer_backlink(realdotgit.buf))) {
 690                         fn(1, realdotgit.buf, _("unable to locate repository; .git file does not reference a repository"), cb_data);
 691                         goto done;
 692                 }
 693         } else if (err) {
 694                 fn(1, realdotgit.buf, _("unable to locate repository; .git file broken"), cb_data);
 695                 goto done;
 696         }
 697
 698         strbuf_addf(&gitdir, "%s/gitdir", backlink);
 699         if (strbuf_read_file(&olddotgit, gitdir.buf, 0) < 0)
 700                 repair = _("gitdir unreadable");
 701         else {
 702                 strbuf_rtrim(&olddotgit);
 703                 if (fspathcmp(olddotgit.buf, realdotgit.buf))
 704                         repair = _("gitdir incorrect");
 705         }
 706
 707         if (repair) {
 708                 fn(0, gitdir.buf, repair, cb_data);
 709                 write_file(gitdir.buf, "%s", realdotgit.buf);
 710         }
 711 done:
 712         free(backlink);
 713         strbuf_release(&olddotgit);
 714         strbuf_release(&gitdir);
 715         strbuf_release(&realdotgit);
 716         strbuf_release(&dotgit);
 717 }
 718
 719 int should_prune_worktree(const char *id, struct strbuf *reason, char **wtpath, timestamp_t expire)
 720 {
 721         struct stat st;
 722         char *path;
 723         int fd;
 724         size_t len;
 725         ssize_t read_result;
 726
 727         *wtpath = NULL;
 728         if (!is_directory(git_path("worktrees/%s", id))) {
 729                 strbuf_addstr(reason, _("not a valid directory"));
 730                 return 1;
 731         }
 732         if (file_exists(git_path("worktrees/%s/locked", id)))
 733                 return 0;
 734         if (stat(git_path("worktrees/%s/gitdir", id), &st)) {
 735                 strbuf_addstr(reason, _("gitdir file does not exist"));
 736                 return 1;
 737         }
 738         fd = open(git_path("worktrees/%s/gitdir", id), O_RDONLY);
 739         if (fd < 0) {
 740                 strbuf_addf(reason, _("unable to read gitdir file (%s)"),
 741                             strerror(errno));
 742                 return 1;
 743         }
 744         len = xsize_t(st.st_size);
 745         path = xmallocz(len);
 746
 747         read_result = read_in_full(fd, path, len);
 748         if (read_result < 0) {
 749                 strbuf_addf(reason, _("unable to read gitdir file (%s)"),
 750                             strerror(errno));
 751                 close(fd);
 752                 free(path);
 753                 return 1;
 754         }
 755         close(fd);
 756
 757         if (read_result != len) {
 758                 strbuf_addf(reason,
 759                             _("short read (expected %"PRIuMAX" bytes, read %"PRIuMAX")"),
 760                             (uintmax_t)len, (uintmax_t)read_result);
 761                 free(path);
 762                 return 1;
 763         }
 764         while (len && (path[len - 1] == '\n' || path[len - 1] == '\r'))
 765                 len--;
 766         if (!len) {
 767                 strbuf_addstr(reason, _("invalid gitdir file"));
 768                 free(path);
 769                 return 1;
 770         }
 771         path[len] = '\0';
 772         if (!file_exists(path)) {
 773                 if (stat(git_path("worktrees/%s/index", id), &st) ||
 774                     st.st_mtime <= expire) {
 775                         strbuf_addstr(reason, _("gitdir file points to non-existent location"));
 776                         free(path);
 777                         return 1;
 778                 } else {
 779                         *wtpath = path;
 780                         return 0;
 781                 }
 782         }
 783         *wtpath = path;
 784         return 0;
 785 }
 786
 787 static int move_config_setting(const char *key, const char *value,
 788                                const char *from_file, const char *to_file)
 789 {
 790         if (git_config_set_in_file_gently(to_file, key, value))
 791                 return error(_("unable to set %s in '%s'"), key, to_file);
 792         if (git_config_set_in_file_gently(from_file, key, NULL))
 793                 return error(_("unable to unset %s in '%s'"), key, from_file);
 794         return 0;
 795 }
 796
 797 int init_worktree_config(struct repository *r)
 798 {
 799         int res = 0;
 800         int bare = 0;
 801         struct config_set cs = { { 0 } };
 802         const char *core_worktree;
 803         char *common_config_file;
 804         char *main_worktree_file;
 805
 806         /*
 807          * If the extension is already enabled, then we can skip the
 808          * upgrade process.
 809          */
 810         if (r->repository_format_worktree_config)
 811                 return 0;
 812         if ((res = git_config_set_gently("extensions.worktreeConfig", "true")))
 813                 return error(_("failed to set extensions.worktreeConfig setting"));
 814
 815         common_config_file = xstrfmt("%s/config", r->commondir);
 816         main_worktree_file = xstrfmt("%s/config.worktree", r->commondir);
 817
 818         git_configset_init(&cs);
 819         git_configset_add_file(&cs, common_config_file);
 820
 821         /*
 822          * If core.bare is true in the common config file, then we need to
 823          * move it to the main worktree's config file or it will break all
 824          * worktrees. If it is false, then leave it in place because it
 825          * _could_ be negating a global core.bare=true.
 826          */
 827         if (!git_configset_get_bool(&cs, "core.bare", &bare) && bare) {
 828                 if ((res = move_config_setting("core.bare", "true",
 829                                                common_config_file,
 830                                                main_worktree_file)))
 831                         goto cleanup;
 832         }
 833         /*
 834          * If core.worktree is set, then the main worktree is located
 835          * somewhere different than the parent of the common Git dir.
 836          * Relocate that value to avoid breaking all worktrees with this
 837          * upgrade to worktree config.
 838          */
 839         if (!git_configset_get_value(&cs, "core.worktree", &core_worktree, NULL)) {
 840                 if ((res = move_config_setting("core.worktree", core_worktree,
 841                                                common_config_file,
 842                                                main_worktree_file)))
 843                         goto cleanup;
 844         }
 845
 846         /*
 847          * Ensure that we use worktree config for the remaining lifetime
 848          * of the current process.
 849          */
 850         r->repository_format_worktree_config = 1;
 851
 852 cleanup:
 853         git_configset_clear(&cs);
 854         free(common_config_file);
 855         free(main_worktree_file);
 856         return res;
 857 }