git

1
#define USE_THE_REPOSITORY_VARIABLE
2

3
#include "git-compat-util.h"
4
#include "abspath.h"
5
#include "environment.h"
6
#include "gettext.h"
7
#include "path.h"
8
#include "repository.h"
9
#include "refs.h"
10
#include "setup.h"
11
#include "strbuf.h"
12
#include "worktree.h"
13
#include "dir.h"
14
#include "wt-status.h"
15
#include "config.h"
16

17
void free_worktree(struct worktree *worktree)
18
{
19
	if (!worktree)
20
		return;
21
	free(worktree->path);
22
	free(worktree->id);
23
	free(worktree->head_ref);
24
	free(worktree->lock_reason);
25
	free(worktree->prune_reason);
26
	free(worktree);
27
}
28

29
void free_worktrees(struct worktree **worktrees)
30
{
31
	int i = 0;
32
	for (i = 0; worktrees[i]; i++)
33
		free_worktree(worktrees[i]);
34
	free (worktrees);
35
}
36

37
/**
38
 * Update head_oid, head_ref and is_detached of the given worktree
39
 */
40
static void add_head_info(struct worktree *wt)
41
{
42
	int flags;
43
	const char *target;
44

45
	target = refs_resolve_ref_unsafe(get_worktree_ref_store(wt),
46
					 "HEAD",
47
					 0,
48
					 &wt->head_oid, &flags);
49
	if (!target)
50
		return;
51

52
	if (flags & REF_ISSYMREF)
53
		wt->head_ref = xstrdup(target);
54
	else
55
		wt->is_detached = 1;
56
}
57

58
static int is_current_worktree(struct worktree *wt)
59
{
60
	char *git_dir = absolute_pathdup(get_git_dir());
61
	const char *wt_git_dir = get_worktree_git_dir(wt);
62
	int is_current = !fspathcmp(git_dir, absolute_path(wt_git_dir));
63
	free(git_dir);
64
	return is_current;
65
}
66

67
/**
68
 * get the main worktree
69
 */
70
static struct worktree *get_main_worktree(int skip_reading_head)
71
{
72
	struct worktree *worktree = NULL;
73
	struct strbuf worktree_path = STRBUF_INIT;
74

75
	strbuf_add_real_path(&worktree_path, get_git_common_dir());
76
	strbuf_strip_suffix(&worktree_path, "/.git");
77

78
	CALLOC_ARRAY(worktree, 1);
79
	worktree->repo = the_repository;
80
	worktree->path = strbuf_detach(&worktree_path, NULL);
81
	/*
82
	 * NEEDSWORK: If this function is called from a secondary worktree and
83
	 * config.worktree is present, is_bare_repository_cfg will reflect the
84
	 * contents of config.worktree, not the contents of the main worktree.
85
	 * This means that worktree->is_bare may be set to 0 even if the main
86
	 * worktree is configured to be bare.
87
	 */
88
	worktree->is_bare = (is_bare_repository_cfg == 1) ||
89
		is_bare_repository();
90
	worktree->is_current = is_current_worktree(worktree);
91
	if (!skip_reading_head)
92
		add_head_info(worktree);
93
	return worktree;
94
}
95

96
struct worktree *get_linked_worktree(const char *id,
97
				     int skip_reading_head)
98
{
99
	struct worktree *worktree = NULL;
100
	struct strbuf path = STRBUF_INIT;
101
	struct strbuf worktree_path = STRBUF_INIT;
102

103
	if (!id)
104
		die("Missing linked worktree name");
105

106
	strbuf_git_common_path(&path, the_repository, "worktrees/%s/gitdir", id);
107
	if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
108
		/* invalid gitdir file */
109
		goto done;
110
	strbuf_rtrim(&worktree_path);
111
	strbuf_strip_suffix(&worktree_path, "/.git");
112

113
	CALLOC_ARRAY(worktree, 1);
114
	worktree->repo = the_repository;
115
	worktree->path = strbuf_detach(&worktree_path, NULL);
116
	worktree->id = xstrdup(id);
117
	worktree->is_current = is_current_worktree(worktree);
118
	if (!skip_reading_head)
119
		add_head_info(worktree);
120

121
done:
122
	strbuf_release(&path);
123
	strbuf_release(&worktree_path);
124
	return worktree;
125
}
126

127
/*
128
 * NEEDSWORK: This function exists so that we can look up metadata of a
129
 * worktree without trying to access any of its internals like the refdb. It
130
 * would be preferable to instead have a corruption-tolerant function for
131
 * retrieving worktree metadata that could be used when the worktree is known
132
 * to not be in a healthy state, e.g. when creating or repairing it.
133
 */
134
static struct worktree **get_worktrees_internal(int skip_reading_head)
135
{
136
	struct worktree **list = NULL;
137
	struct strbuf path = STRBUF_INIT;
138
	DIR *dir;
139
	struct dirent *d;
140
	int counter = 0, alloc = 2;
141

142
	ALLOC_ARRAY(list, alloc);
143

144
	list[counter++] = get_main_worktree(skip_reading_head);
145

146
	strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
147
	dir = opendir(path.buf);
148
	strbuf_release(&path);
149
	if (dir) {
150
		while ((d = readdir_skip_dot_and_dotdot(dir)) != NULL) {
151
			struct worktree *linked = NULL;
152

153
			if ((linked = get_linked_worktree(d->d_name, skip_reading_head))) {
154
				ALLOC_GROW(list, counter + 1, alloc);
155
				list[counter++] = linked;
156
			}
157
		}
158
		closedir(dir);
159
	}
160
	ALLOC_GROW(list, counter + 1, alloc);
161
	list[counter] = NULL;
162

163
	return list;
164
}
165

166
struct worktree **get_worktrees(void)
167
{
168
	return get_worktrees_internal(0);
169
}
170

171
const char *get_worktree_git_dir(const struct worktree *wt)
172
{
173
	if (!wt)
174
		return get_git_dir();
175
	else if (!wt->id)
176
		return get_git_common_dir();
177
	else
178
		return git_common_path("worktrees/%s", wt->id);
179
}
180

181
static struct worktree *find_worktree_by_suffix(struct worktree **list,
182
						const char *suffix)
183
{
184
	struct worktree *found = NULL;
185
	int nr_found = 0, suffixlen;
186

187
	suffixlen = strlen(suffix);
188
	if (!suffixlen)
189
		return NULL;
190

191
	for (; *list && nr_found < 2; list++) {
192
		const char	*path	 = (*list)->path;
193
		int		 pathlen = strlen(path);
194
		int		 start	 = pathlen - suffixlen;
195

196
		/* suffix must start at directory boundary */
197
		if ((!start || (start > 0 && is_dir_sep(path[start - 1]))) &&
198
		    !fspathcmp(suffix, path + start)) {
199
			found = *list;
200
			nr_found++;
201
		}
202
	}
203
	return nr_found == 1 ? found : NULL;
204
}
205

206
struct worktree *find_worktree(struct worktree **list,
207
			       const char *prefix,
208
			       const char *arg)
209
{
210
	struct worktree *wt;
211
	char *to_free = NULL;
212

213
	if ((wt = find_worktree_by_suffix(list, arg)))
214
		return wt;
215

216
	if (prefix)
217
		arg = to_free = prefix_filename(prefix, arg);
218
	wt = find_worktree_by_path(list, arg);
219
	free(to_free);
220
	return wt;
221
}
222

223
struct worktree *find_worktree_by_path(struct worktree **list, const char *p)
224
{
225
	struct strbuf wt_path = STRBUF_INIT;
226
	char *path = real_pathdup(p, 0);
227

228
	if (!path)
229
		return NULL;
230
	for (; *list; list++) {
231
		if (!strbuf_realpath(&wt_path, (*list)->path, 0))
232
			continue;
233

234
		if (!fspathcmp(path, wt_path.buf))
235
			break;
236
	}
237
	free(path);
238
	strbuf_release(&wt_path);
239
	return *list;
240
}
241

242
int is_main_worktree(const struct worktree *wt)
243
{
244
	return !wt->id;
245
}
246

247
const char *worktree_lock_reason(struct worktree *wt)
248
{
249
	if (is_main_worktree(wt))
250
		return NULL;
251

252
	if (!wt->lock_reason_valid) {
253
		struct strbuf path = STRBUF_INIT;
254

255
		strbuf_addstr(&path, worktree_git_path(the_repository, wt, "locked"));
256
		if (file_exists(path.buf)) {
257
			struct strbuf lock_reason = STRBUF_INIT;
258
			if (strbuf_read_file(&lock_reason, path.buf, 0) < 0)
259
				die_errno(_("failed to read '%s'"), path.buf);
260
			strbuf_trim(&lock_reason);
261
			wt->lock_reason = strbuf_detach(&lock_reason, NULL);
262
		} else
263
			wt->lock_reason = NULL;
264
		wt->lock_reason_valid = 1;
265
		strbuf_release(&path);
266
	}
267

268
	return wt->lock_reason;
269
}
270

271
const char *worktree_prune_reason(struct worktree *wt, timestamp_t expire)
272
{
273
	struct strbuf reason = STRBUF_INIT;
274
	char *path = NULL;
275

276
	if (is_main_worktree(wt))
277
		return NULL;
278
	if (wt->prune_reason_valid)
279
		return wt->prune_reason;
280

281
	if (should_prune_worktree(wt->id, &reason, &path, expire))
282
		wt->prune_reason = strbuf_detach(&reason, NULL);
283
	wt->prune_reason_valid = 1;
284

285
	strbuf_release(&reason);
286
	free(path);
287
	return wt->prune_reason;
288
}
289

290
/* convenient wrapper to deal with NULL strbuf */
291
__attribute__((format (printf, 2, 3)))
292
static void strbuf_addf_gently(struct strbuf *buf, const char *fmt, ...)
293
{
294
	va_list params;
295

296
	if (!buf)
297
		return;
298

299
	va_start(params, fmt);
300
	strbuf_vaddf(buf, fmt, params);
301
	va_end(params);
302
}
303

304
int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
305
		      unsigned flags)
306
{
307
	struct strbuf wt_path = STRBUF_INIT;
308
	struct strbuf realpath = STRBUF_INIT;
309
	char *path = NULL;
310
	int err, ret = -1;
311

312
	strbuf_addf(&wt_path, "%s/.git", wt->path);
313

314
	if (is_main_worktree(wt)) {
315
		if (is_directory(wt_path.buf)) {
316
			ret = 0;
317
			goto done;
318
		}
319
		/*
320
		 * Main worktree using .git file to point to the
321
		 * repository would make it impossible to know where
322
		 * the actual worktree is if this function is executed
323
		 * from another worktree. No .git file support for now.
324
		 */
325
		strbuf_addf_gently(errmsg,
326
				   _("'%s' at main working tree is not the repository directory"),
327
				   wt_path.buf);
328
		goto done;
329
	}
330

331
	/*
332
	 * Make sure "gitdir" file points to a real .git file and that
333
	 * file points back here.
334
	 */
335
	if (!is_absolute_path(wt->path)) {
336
		strbuf_addf_gently(errmsg,
337
				   _("'%s' file does not contain absolute path to the working tree location"),
338
				   git_common_path("worktrees/%s/gitdir", wt->id));
339
		goto done;
340
	}
341

342
	if (flags & WT_VALIDATE_WORKTREE_MISSING_OK &&
343
	    !file_exists(wt->path)) {
344
		ret = 0;
345
		goto done;
346
	}
347

348
	if (!file_exists(wt_path.buf)) {
349
		strbuf_addf_gently(errmsg, _("'%s' does not exist"), wt_path.buf);
350
		goto done;
351
	}
352

353
	path = xstrdup_or_null(read_gitfile_gently(wt_path.buf, &err));
354
	if (!path) {
355
		strbuf_addf_gently(errmsg, _("'%s' is not a .git file, error code %d"),
356
				   wt_path.buf, err);
357
		goto done;
358
	}
359

360
	strbuf_realpath(&realpath, git_common_path("worktrees/%s", wt->id), 1);
361
	ret = fspathcmp(path, realpath.buf);
362

363
	if (ret)
364
		strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
365
				   wt->path, git_common_path("worktrees/%s", wt->id));
366
done:
367
	free(path);
368
	strbuf_release(&wt_path);
369
	strbuf_release(&realpath);
370
	return ret;
371
}
372

373
void update_worktree_location(struct worktree *wt, const char *path_)
374
{
375
	struct strbuf path = STRBUF_INIT;
376

377
	if (is_main_worktree(wt))
378
		BUG("can't relocate main worktree");
379

380
	strbuf_realpath(&path, path_, 1);
381
	if (fspathcmp(wt->path, path.buf)) {
382
		write_file(git_common_path("worktrees/%s/gitdir", wt->id),
383
			   "%s/.git", path.buf);
384
		free(wt->path);
385
		wt->path = strbuf_detach(&path, NULL);
386
	}
387
	strbuf_release(&path);
388
}
389

390
int is_worktree_being_rebased(const struct worktree *wt,
391
			      const char *target)
392
{
393
	struct wt_status_state state;
394
	int found_rebase;
395

396
	memset(&state, 0, sizeof(state));
397
	found_rebase = wt_status_check_rebase(wt, &state) &&
398
		       (state.rebase_in_progress ||
399
			state.rebase_interactive_in_progress) &&
400
		       state.branch &&
401
		       skip_prefix(target, "refs/heads/", &target) &&
402
		       !strcmp(state.branch, target);
403
	wt_status_state_free_buffers(&state);
404
	return found_rebase;
405
}
406

407
int is_worktree_being_bisected(const struct worktree *wt,
408
			       const char *target)
409
{
410
	struct wt_status_state state;
411
	int found_bisect;
412

413
	memset(&state, 0, sizeof(state));
414
	found_bisect = wt_status_check_bisect(wt, &state) &&
415
		       state.bisecting_from &&
416
		       skip_prefix(target, "refs/heads/", &target) &&
417
		       !strcmp(state.bisecting_from, target);
418
	wt_status_state_free_buffers(&state);
419
	return found_bisect;
420
}
421

422
/*
423
 * note: this function should be able to detect shared symref even if
424
 * HEAD is temporarily detached (e.g. in the middle of rebase or
425
 * bisect). New commands that do similar things should update this
426
 * function as well.
427
 */
428
int is_shared_symref(const struct worktree *wt, const char *symref,
429
		     const char *target)
430
{
431
	const char *symref_target;
432
	struct ref_store *refs;
433
	int flags;
434

435
	if (wt->is_bare)
436
		return 0;
437

438
	if (wt->is_detached && !strcmp(symref, "HEAD")) {
439
		if (is_worktree_being_rebased(wt, target))
440
			return 1;
441
		if (is_worktree_being_bisected(wt, target))
442
			return 1;
443
	}
444

445
	refs = get_worktree_ref_store(wt);
446
	symref_target = refs_resolve_ref_unsafe(refs, symref, 0,
447
						NULL, &flags);
448
	if ((flags & REF_ISSYMREF) &&
449
	    symref_target && !strcmp(symref_target, target))
450
		return 1;
451

452
	return 0;
453
}
454

455
const struct worktree *find_shared_symref(struct worktree **worktrees,
456
					  const char *symref,
457
					  const char *target)
458
{
459

460
	for (int i = 0; worktrees[i]; i++)
461
		if (is_shared_symref(worktrees[i], symref, target))
462
			return worktrees[i];
463

464
	return NULL;
465
}
466

467
int submodule_uses_worktrees(const char *path)
468
{
469
	char *submodule_gitdir;
470
	struct strbuf sb = STRBUF_INIT, err = STRBUF_INIT;
471
	DIR *dir;
472
	struct dirent *d;
473
	int ret = 0;
474
	struct repository_format format = REPOSITORY_FORMAT_INIT;
475

476
	submodule_gitdir = git_pathdup_submodule(path, "%s", "");
477
	if (!submodule_gitdir)
478
		return 0;
479

480
	/* The env would be set for the superproject. */
481
	get_common_dir_noenv(&sb, submodule_gitdir);
482
	free(submodule_gitdir);
483

484
	strbuf_addstr(&sb, "/config");
485
	read_repository_format(&format, sb.buf);
486
	if (verify_repository_format(&format, &err)) {
487
		strbuf_release(&err);
488
		strbuf_release(&sb);
489
		clear_repository_format(&format);
490
		return 1;
491
	}
492
	clear_repository_format(&format);
493
	strbuf_release(&err);
494

495
	/* Replace config by worktrees. */
496
	strbuf_setlen(&sb, sb.len - strlen("config"));
497
	strbuf_addstr(&sb, "worktrees");
498

499
	/* See if there is any file inside the worktrees directory. */
500
	dir = opendir(sb.buf);
501
	strbuf_release(&sb);
502

503
	if (!dir)
504
		return 0;
505

506
	d = readdir_skip_dot_and_dotdot(dir);
507
	if (d)
508
		ret = 1;
509
	closedir(dir);
510
	return ret;
511
}
512

513
void strbuf_worktree_ref(const struct worktree *wt,
514
			 struct strbuf *sb,
515
			 const char *refname)
516
{
517
	if (parse_worktree_ref(refname, NULL, NULL, NULL) ==
518
		    REF_WORKTREE_CURRENT &&
519
	    wt && !wt->is_current) {
520
		if (is_main_worktree(wt))
521
			strbuf_addstr(sb, "main-worktree/");
522
		else
523
			strbuf_addf(sb, "worktrees/%s/", wt->id);
524
	}
525
	strbuf_addstr(sb, refname);
526
}
527

528
int other_head_refs(each_ref_fn fn, void *cb_data)
529
{
530
	struct worktree **worktrees, **p;
531
	struct strbuf refname = STRBUF_INIT;
532
	int ret = 0;
533

534
	worktrees = get_worktrees();
535
	for (p = worktrees; *p; p++) {
536
		struct worktree *wt = *p;
537
		struct object_id oid;
538
		int flag;
539

540
		if (wt->is_current)
541
			continue;
542

543
		strbuf_reset(&refname);
544
		strbuf_worktree_ref(wt, &refname, "HEAD");
545
		if (refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
546
					    refname.buf,
547
					    RESOLVE_REF_READING,
548
					    &oid, &flag))
549
			ret = fn(refname.buf, NULL, &oid, flag, cb_data);
550
		if (ret)
551
			break;
552
	}
553
	free_worktrees(worktrees);
554
	strbuf_release(&refname);
555
	return ret;
556
}
557

558
/*
559
 * Repair worktree's /path/to/worktree/.git file if missing, corrupt, or not
560
 * pointing at <repo>/worktrees/<id>.
561
 */
562
static void repair_gitfile(struct worktree *wt,
563
			   worktree_repair_fn fn, void *cb_data)
564
{
565
	struct strbuf dotgit = STRBUF_INIT;
566
	struct strbuf repo = STRBUF_INIT;
567
	char *backlink;
568
	const char *repair = NULL;
569
	int err;
570

571
	/* missing worktree can't be repaired */
572
	if (!file_exists(wt->path))
573
		return;
574

575
	if (!is_directory(wt->path)) {
576
		fn(1, wt->path, _("not a directory"), cb_data);
577
		return;
578
	}
579

580
	strbuf_realpath(&repo, git_common_path("worktrees/%s", wt->id), 1);
581
	strbuf_addf(&dotgit, "%s/.git", wt->path);
582
	backlink = xstrdup_or_null(read_gitfile_gently(dotgit.buf, &err));
583

584
	if (err == READ_GITFILE_ERR_NOT_A_FILE)
585
		fn(1, wt->path, _(".git is not a file"), cb_data);
586
	else if (err)
587
		repair = _(".git file broken");
588
	else if (fspathcmp(backlink, repo.buf))
589
		repair = _(".git file incorrect");
590

591
	if (repair) {
592
		fn(0, wt->path, repair, cb_data);
593
		write_file(dotgit.buf, "gitdir: %s", repo.buf);
594
	}
595

596
	free(backlink);
597
	strbuf_release(&repo);
598
	strbuf_release(&dotgit);
599
}
600

601
static void repair_noop(int iserr UNUSED,
602
			const char *path UNUSED,
603
			const char *msg UNUSED,
604
			void *cb_data UNUSED)
605
{
606
	/* nothing */
607
}
608

609
void repair_worktrees(worktree_repair_fn fn, void *cb_data)
610
{
611
	struct worktree **worktrees = get_worktrees_internal(1);
612
	struct worktree **wt = worktrees + 1; /* +1 skips main worktree */
613

614
	if (!fn)
615
		fn = repair_noop;
616
	for (; *wt; wt++)
617
		repair_gitfile(*wt, fn, cb_data);
618
	free_worktrees(worktrees);
619
}
620

621
static int is_main_worktree_path(const char *path)
622
{
623
	struct strbuf target = STRBUF_INIT;
624
	struct strbuf maindir = STRBUF_INIT;
625
	int cmp;
626

627
	strbuf_add_real_path(&target, path);
628
	strbuf_strip_suffix(&target, "/.git");
629
	strbuf_add_real_path(&maindir, get_git_common_dir());
630
	strbuf_strip_suffix(&maindir, "/.git");
631
	cmp = fspathcmp(maindir.buf, target.buf);
632

633
	strbuf_release(&maindir);
634
	strbuf_release(&target);
635
	return !cmp;
636
}
637

638
/*
639
 * If both the main worktree and linked worktree have been moved, then the
640
 * gitfile /path/to/worktree/.git won't point into the repository, thus we
641
 * won't know which <repo>/worktrees/<id>/gitdir to repair. However, we may
642
 * be able to infer the gitdir by manually reading /path/to/worktree/.git,
643
 * extracting the <id>, and checking if <repo>/worktrees/<id> exists.
644
 */
645
static char *infer_backlink(const char *gitfile)
646
{
647
	struct strbuf actual = STRBUF_INIT;
648
	struct strbuf inferred = STRBUF_INIT;
649
	const char *id;
650

651
	if (strbuf_read_file(&actual, gitfile, 0) < 0)
652
		goto error;
653
	if (!starts_with(actual.buf, "gitdir:"))
654
		goto error;
655
	if (!(id = find_last_dir_sep(actual.buf)))
656
		goto error;
657
	strbuf_trim(&actual);
658
	id++; /* advance past '/' to point at <id> */
659
	if (!*id)
660
		goto error;
661
	strbuf_git_common_path(&inferred, the_repository, "worktrees/%s", id);
662
	if (!is_directory(inferred.buf))
663
		goto error;
664

665
	strbuf_release(&actual);
666
	return strbuf_detach(&inferred, NULL);
667

668
error:
669
	strbuf_release(&actual);
670
	strbuf_release(&inferred);
671
	return NULL;
672
}
673

674
/*
675
 * Repair <repo>/worktrees/<id>/gitdir if missing, corrupt, or not pointing at
676
 * the worktree's path.
677
 */
678
void repair_worktree_at_path(const char *path,
679
			     worktree_repair_fn fn, void *cb_data)
680
{
681
	struct strbuf dotgit = STRBUF_INIT;
682
	struct strbuf realdotgit = STRBUF_INIT;
683
	struct strbuf gitdir = STRBUF_INIT;
684
	struct strbuf olddotgit = STRBUF_INIT;
685
	char *backlink = NULL;
686
	const char *repair = NULL;
687
	int err;
688

689
	if (!fn)
690
		fn = repair_noop;
691

692
	if (is_main_worktree_path(path))
693
		goto done;
694

695
	strbuf_addf(&dotgit, "%s/.git", path);
696
	if (!strbuf_realpath(&realdotgit, dotgit.buf, 0)) {
697
		fn(1, path, _("not a valid path"), cb_data);
698
		goto done;
699
	}
700

701
	backlink = xstrdup_or_null(read_gitfile_gently(realdotgit.buf, &err));
702
	if (err == READ_GITFILE_ERR_NOT_A_FILE) {
703
		fn(1, realdotgit.buf, _("unable to locate repository; .git is not a file"), cb_data);
704
		goto done;
705
	} else if (err == READ_GITFILE_ERR_NOT_A_REPO) {
706
		if (!(backlink = infer_backlink(realdotgit.buf))) {
707
			fn(1, realdotgit.buf, _("unable to locate repository; .git file does not reference a repository"), cb_data);
708
			goto done;
709
		}
710
	} else if (err) {
711
		fn(1, realdotgit.buf, _("unable to locate repository; .git file broken"), cb_data);
712
		goto done;
713
	}
714

715
	strbuf_addf(&gitdir, "%s/gitdir", backlink);
716
	if (strbuf_read_file(&olddotgit, gitdir.buf, 0) < 0)
717
		repair = _("gitdir unreadable");
718
	else {
719
		strbuf_rtrim(&olddotgit);
720
		if (fspathcmp(olddotgit.buf, realdotgit.buf))
721
			repair = _("gitdir incorrect");
722
	}
723

724
	if (repair) {
725
		fn(0, gitdir.buf, repair, cb_data);
726
		write_file(gitdir.buf, "%s", realdotgit.buf);
727
	}
728
done:
729
	free(backlink);
730
	strbuf_release(&olddotgit);
731
	strbuf_release(&gitdir);
732
	strbuf_release(&realdotgit);
733
	strbuf_release(&dotgit);
734
}
735

736
int should_prune_worktree(const char *id, struct strbuf *reason, char **wtpath, timestamp_t expire)
737
{
738
	struct stat st;
739
	char *path;
740
	int fd;
741
	size_t len;
742
	ssize_t read_result;
743

744
	*wtpath = NULL;
745
	if (!is_directory(git_path("worktrees/%s", id))) {
746
		strbuf_addstr(reason, _("not a valid directory"));
747
		return 1;
748
	}
749
	if (file_exists(git_path("worktrees/%s/locked", id)))
750
		return 0;
751
	if (stat(git_path("worktrees/%s/gitdir", id), &st)) {
752
		strbuf_addstr(reason, _("gitdir file does not exist"));
753
		return 1;
754
	}
755
	fd = open(git_path("worktrees/%s/gitdir", id), O_RDONLY);
756
	if (fd < 0) {
757
		strbuf_addf(reason, _("unable to read gitdir file (%s)"),
758
			    strerror(errno));
759
		return 1;
760
	}
761
	len = xsize_t(st.st_size);
762
	path = xmallocz(len);
763

764
	read_result = read_in_full(fd, path, len);
765
	if (read_result < 0) {
766
		strbuf_addf(reason, _("unable to read gitdir file (%s)"),
767
			    strerror(errno));
768
		close(fd);
769
		free(path);
770
		return 1;
771
	}
772
	close(fd);
773

774
	if (read_result != len) {
775
		strbuf_addf(reason,
776
			    _("short read (expected %"PRIuMAX" bytes, read %"PRIuMAX")"),
777
			    (uintmax_t)len, (uintmax_t)read_result);
778
		free(path);
779
		return 1;
780
	}
781
	while (len && (path[len - 1] == '\n' || path[len - 1] == '\r'))
782
		len--;
783
	if (!len) {
784
		strbuf_addstr(reason, _("invalid gitdir file"));
785
		free(path);
786
		return 1;
787
	}
788
	path[len] = '\0';
789
	if (!file_exists(path)) {
790
		if (stat(git_path("worktrees/%s/index", id), &st) ||
791
		    st.st_mtime <= expire) {
792
			strbuf_addstr(reason, _("gitdir file points to non-existent location"));
793
			free(path);
794
			return 1;
795
		} else {
796
			*wtpath = path;
797
			return 0;
798
		}
799
	}
800
	*wtpath = path;
801
	return 0;
802
}
803

804
static int move_config_setting(const char *key, const char *value,
805
			       const char *from_file, const char *to_file)
806
{
807
	if (git_config_set_in_file_gently(to_file, key, NULL, value))
808
		return error(_("unable to set %s in '%s'"), key, to_file);
809
	if (git_config_set_in_file_gently(from_file, key, NULL, NULL))
810
		return error(_("unable to unset %s in '%s'"), key, from_file);
811
	return 0;
812
}
813

814
int init_worktree_config(struct repository *r)
815
{
816
	int res = 0;
817
	int bare = 0;
818
	struct config_set cs = { { 0 } };
819
	const char *core_worktree;
820
	char *common_config_file;
821
	char *main_worktree_file;
822

823
	/*
824
	 * If the extension is already enabled, then we can skip the
825
	 * upgrade process.
826
	 */
827
	if (r->repository_format_worktree_config)
828
		return 0;
829
	if ((res = git_config_set_gently("extensions.worktreeConfig", "true")))
830
		return error(_("failed to set extensions.worktreeConfig setting"));
831

832
	common_config_file = xstrfmt("%s/config", r->commondir);
833
	main_worktree_file = xstrfmt("%s/config.worktree", r->commondir);
834

835
	git_configset_init(&cs);
836
	git_configset_add_file(&cs, common_config_file);
837

838
	/*
839
	 * If core.bare is true in the common config file, then we need to
840
	 * move it to the main worktree's config file or it will break all
841
	 * worktrees. If it is false, then leave it in place because it
842
	 * _could_ be negating a global core.bare=true.
843
	 */
844
	if (!git_configset_get_bool(&cs, "core.bare", &bare) && bare) {
845
		if ((res = move_config_setting("core.bare", "true",
846
					       common_config_file,
847
					       main_worktree_file)))
848
			goto cleanup;
849
	}
850
	/*
851
	 * If core.worktree is set, then the main worktree is located
852
	 * somewhere different than the parent of the common Git dir.
853
	 * Relocate that value to avoid breaking all worktrees with this
854
	 * upgrade to worktree config.
855
	 */
856
	if (!git_configset_get_value(&cs, "core.worktree", &core_worktree, NULL)) {
857
		if ((res = move_config_setting("core.worktree", core_worktree,
858
					       common_config_file,
859
					       main_worktree_file)))
860
			goto cleanup;
861
	}
862

863
	/*
864
	 * Ensure that we use worktree config for the remaining lifetime
865
	 * of the current process.
866
	 */
867
	r->repository_format_worktree_config = 1;
868

869
cleanup:
870
	git_configset_clear(&cs);
871
	free(common_config_file);
872
	free(main_worktree_file);
873
	return res;
874
}
875