1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/stat.h>
18 #include <sys/limits.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 
22 #include <dirent.h>
23 #include <stddef.h>
24 #include <string.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <fcntl.h>
28 #include <errno.h>
29 #include <unistd.h>
30 #include <sha1.h>
31 #include <zlib.h>
32 #include <fnmatch.h>
33 #include <libgen.h>
34 #include <uuid.h>
35 #include <util.h>
36 
37 #include "got_error.h"
38 #include "got_repository.h"
39 #include "got_reference.h"
40 #include "got_object.h"
41 #include "got_path.h"
42 #include "got_worktree.h"
43 #include "got_opentemp.h"
44 #include "got_diff.h"
45 
46 #include "got_lib_worktree.h"
47 #include "got_lib_sha1.h"
48 #include "got_lib_fileindex.h"
49 #include "got_lib_inflate.h"
50 #include "got_lib_delta.h"
51 #include "got_lib_object.h"
52 #include "got_lib_object_parse.h"
53 #include "got_lib_object_create.h"
54 #include "got_lib_object_idset.h"
55 #include "got_lib_diff.h"
56 
57 #ifndef MIN
58 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
59 #endif
60 
61 static const struct got_error *
62 create_meta_file(const char *path_got, const char *name, const char *content)
63 {
64 	const struct got_error *err = NULL;
65 	char *path;
66 
67 	if (asprintf(&path, "%s/%s", path_got, name) == -1)
68 		return got_error_from_errno("asprintf");
69 
70 	err = got_path_create_file(path, content);
71 	free(path);
72 	return err;
73 }
74 
75 static const struct got_error *
76 update_meta_file(const char *path_got, const char *name, const char *content)
77 {
78 	const struct got_error *err = NULL;
79 	FILE *tmpfile = NULL;
80 	char *tmppath = NULL;
81 	char *path = NULL;
82 
83 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
84 		err = got_error_from_errno("asprintf");
85 		path = NULL;
86 		goto done;
87 	}
88 
89 	err = got_opentemp_named(&tmppath, &tmpfile, path);
90 	if (err)
91 		goto done;
92 
93 	if (content) {
94 		int len = fprintf(tmpfile, "%s\n", content);
95 		if (len != strlen(content) + 1) {
96 			err = got_error_from_errno2("fprintf", tmppath);
97 			goto done;
98 		}
99 	}
100 
101 	if (rename(tmppath, path) != 0) {
102 		err = got_error_from_errno3("rename", tmppath, path);
103 		unlink(tmppath);
104 		goto done;
105 	}
106 
107 done:
108 	if (fclose(tmpfile) != 0 && err == NULL)
109 		err = got_error_from_errno2("fclose", tmppath);
110 	free(tmppath);
111 	return err;
112 }
113 
114 static const struct got_error *
115 read_meta_file(char **content, const char *path_got, const char *name)
116 {
117 	const struct got_error *err = NULL;
118 	char *path;
119 	int fd = -1;
120 	ssize_t n;
121 	struct stat sb;
122 
123 	*content = NULL;
124 
125 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
126 		err = got_error_from_errno("asprintf");
127 		path = NULL;
128 		goto done;
129 	}
130 
131 	fd = open(path, O_RDONLY | O_NOFOLLOW);
132 	if (fd == -1) {
133 		if (errno == ENOENT)
134 			err = got_error(GOT_ERR_WORKTREE_META);
135 		else
136 			err = got_error_from_errno2("open", path);
137 		goto done;
138 	}
139 	if (flock(fd, LOCK_SH | LOCK_NB) == -1) {
140 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
141 		    : got_error_from_errno2("flock", path));
142 		goto done;
143 	}
144 
145 	if (lstat(path, &sb) != 0) {
146 		err = got_error_from_errno2("lstat", path);
147 		goto done;
148 	}
149 	*content = calloc(1, sb.st_size);
150 	if (*content == NULL) {
151 		err = got_error_from_errno("calloc");
152 		goto done;
153 	}
154 
155 	n = read(fd, *content, sb.st_size);
156 	if (n != sb.st_size) {
157 		err = (n == -1 ? got_error_from_errno2("read", path) :
158 		    got_error(GOT_ERR_WORKTREE_META));
159 		goto done;
160 	}
161 	if ((*content)[sb.st_size - 1] != '\n') {
162 		err = got_error(GOT_ERR_WORKTREE_META);
163 		goto done;
164 	}
165 	(*content)[sb.st_size - 1] = '\0';
166 
167 done:
168 	if (fd != -1 && close(fd) == -1 && err == NULL)
169 		err = got_error_from_errno2("close", path_got);
170 	free(path);
171 	if (err) {
172 		free(*content);
173 		*content = NULL;
174 	}
175 	return err;
176 }
177 
178 static const struct got_error *
179 write_head_ref(const char *path_got, struct got_reference *head_ref)
180 {
181 	const struct got_error *err = NULL;
182 	char *refstr = NULL;
183 
184 	if (got_ref_is_symbolic(head_ref)) {
185 		refstr = got_ref_to_str(head_ref);
186 		if (refstr == NULL)
187 			return got_error_from_errno("got_ref_to_str");
188 	} else {
189 		refstr = strdup(got_ref_get_name(head_ref));
190 		if (refstr == NULL)
191 			return got_error_from_errno("strdup");
192 	}
193 	err = update_meta_file(path_got, GOT_WORKTREE_HEAD_REF, refstr);
194 	free(refstr);
195 	return err;
196 }
197 
198 const struct got_error *
199 got_worktree_init(const char *path, struct got_reference *head_ref,
200     const char *prefix, struct got_repository *repo)
201 {
202 	const struct got_error *err = NULL;
203 	struct got_object_id *commit_id = NULL;
204 	uuid_t uuid;
205 	uint32_t uuid_status;
206 	int obj_type;
207 	char *path_got = NULL;
208 	char *formatstr = NULL;
209 	char *absprefix = NULL;
210 	char *basestr = NULL;
211 	char *uuidstr = NULL;
212 
213 	if (strcmp(path, got_repo_get_path(repo)) == 0) {
214 		err = got_error(GOT_ERR_WORKTREE_REPO);
215 		goto done;
216 	}
217 
218 	err = got_ref_resolve(&commit_id, repo, head_ref);
219 	if (err)
220 		return err;
221 	err = got_object_get_type(&obj_type, repo, commit_id);
222 	if (err)
223 		return err;
224 	if (obj_type != GOT_OBJ_TYPE_COMMIT)
225 		return got_error(GOT_ERR_OBJ_TYPE);
226 
227 	if (!got_path_is_absolute(prefix)) {
228 		if (asprintf(&absprefix, "/%s", prefix) == -1)
229 			return got_error_from_errno("asprintf");
230 	}
231 
232 	/* Create top-level directory (may already exist). */
233 	if (mkdir(path, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
234 		err = got_error_from_errno2("mkdir", path);
235 		goto done;
236 	}
237 
238 	/* Create .got directory (may already exist). */
239 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
240 		err = got_error_from_errno("asprintf");
241 		goto done;
242 	}
243 	if (mkdir(path_got, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
244 		err = got_error_from_errno2("mkdir", path_got);
245 		goto done;
246 	}
247 
248 	/* Create an empty lock file. */
249 	err = create_meta_file(path_got, GOT_WORKTREE_LOCK, NULL);
250 	if (err)
251 		goto done;
252 
253 	/* Create an empty file index. */
254 	err = create_meta_file(path_got, GOT_WORKTREE_FILE_INDEX, NULL);
255 	if (err)
256 		goto done;
257 
258 	/* Write the HEAD reference. */
259 	err = write_head_ref(path_got, head_ref);
260 	if (err)
261 		goto done;
262 
263 	/* Record our base commit. */
264 	err = got_object_id_str(&basestr, commit_id);
265 	if (err)
266 		goto done;
267 	err = create_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, basestr);
268 	if (err)
269 		goto done;
270 
271 	/* Store path to repository. */
272 	err = create_meta_file(path_got, GOT_WORKTREE_REPOSITORY,
273 	    got_repo_get_path(repo));
274 	if (err)
275 		goto done;
276 
277 	/* Store in-repository path prefix. */
278 	err = create_meta_file(path_got, GOT_WORKTREE_PATH_PREFIX,
279 	    absprefix ? absprefix : prefix);
280 	if (err)
281 		goto done;
282 
283 	/* Generate UUID. */
284 	uuid_create(&uuid, &uuid_status);
285 	if (uuid_status != uuid_s_ok) {
286 		err = got_error_uuid(uuid_status);
287 		goto done;
288 	}
289 	uuid_to_string(&uuid, &uuidstr, &uuid_status);
290 	if (uuid_status != uuid_s_ok) {
291 		err = got_error_uuid(uuid_status);
292 		goto done;
293 	}
294 	err = create_meta_file(path_got, GOT_WORKTREE_UUID, uuidstr);
295 	if (err)
296 		goto done;
297 
298 	/* Stamp work tree with format file. */
299 	if (asprintf(&formatstr, "%d", GOT_WORKTREE_FORMAT_VERSION) == -1) {
300 		err = got_error_from_errno("asprintf");
301 		goto done;
302 	}
303 	err = create_meta_file(path_got, GOT_WORKTREE_FORMAT, formatstr);
304 	if (err)
305 		goto done;
306 
307 done:
308 	free(commit_id);
309 	free(path_got);
310 	free(formatstr);
311 	free(absprefix);
312 	free(basestr);
313 	free(uuidstr);
314 	return err;
315 }
316 
317 static const struct got_error *
318 open_worktree(struct got_worktree **worktree, const char *path)
319 {
320 	const struct got_error *err = NULL;
321 	char *path_got;
322 	char *formatstr = NULL;
323 	char *uuidstr = NULL;
324 	char *path_lock = NULL;
325 	char *base_commit_id_str = NULL;
326 	int version, fd = -1;
327 	const char *errstr;
328 	struct got_repository *repo = NULL;
329 	uint32_t uuid_status;
330 
331 	*worktree = NULL;
332 
333 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
334 		err = got_error_from_errno("asprintf");
335 		path_got = NULL;
336 		goto done;
337 	}
338 
339 	if (asprintf(&path_lock, "%s/%s", path_got, GOT_WORKTREE_LOCK) == -1) {
340 		err = got_error_from_errno("asprintf");
341 		path_lock = NULL;
342 		goto done;
343 	}
344 
345 	fd = open(path_lock, O_RDWR | O_EXLOCK | O_NONBLOCK);
346 	if (fd == -1) {
347 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
348 		    : got_error_from_errno2("open", path_lock));
349 		goto done;
350 	}
351 
352 	err = read_meta_file(&formatstr, path_got, GOT_WORKTREE_FORMAT);
353 	if (err)
354 		goto done;
355 
356 	version = strtonum(formatstr, 1, INT_MAX, &errstr);
357 	if (errstr) {
358 		err = got_error(GOT_ERR_WORKTREE_META);
359 		goto done;
360 	}
361 	if (version != GOT_WORKTREE_FORMAT_VERSION) {
362 		err = got_error(GOT_ERR_WORKTREE_VERS);
363 		goto done;
364 	}
365 
366 	*worktree = calloc(1, sizeof(**worktree));
367 	if (*worktree == NULL) {
368 		err = got_error_from_errno("calloc");
369 		goto done;
370 	}
371 	(*worktree)->lockfd = -1;
372 
373 	(*worktree)->root_path = strdup(path);
374 	if ((*worktree)->root_path == NULL) {
375 		err = got_error_from_errno("strdup");
376 		goto done;
377 	}
378 	err = read_meta_file(&(*worktree)->repo_path, path_got,
379 	    GOT_WORKTREE_REPOSITORY);
380 	if (err)
381 		goto done;
382 
383 	err = read_meta_file(&(*worktree)->path_prefix, path_got,
384 	    GOT_WORKTREE_PATH_PREFIX);
385 	if (err)
386 		goto done;
387 
388 	err = read_meta_file(&base_commit_id_str, path_got,
389 	    GOT_WORKTREE_BASE_COMMIT);
390 	if (err)
391 		goto done;
392 
393 	err = read_meta_file(&uuidstr, path_got, GOT_WORKTREE_UUID);
394 	if (err)
395 		goto done;
396 	uuid_from_string(uuidstr, &(*worktree)->uuid, &uuid_status);
397 	if (uuid_status != uuid_s_ok) {
398 		err = got_error_uuid(uuid_status);
399 		goto done;
400 	}
401 
402 	err = got_repo_open(&repo, (*worktree)->repo_path);
403 	if (err)
404 		goto done;
405 
406 	err = got_object_resolve_id_str(&(*worktree)->base_commit_id, repo,
407 	    base_commit_id_str);
408 	if (err)
409 		goto done;
410 
411 	err = read_meta_file(&(*worktree)->head_ref_name, path_got,
412 	    GOT_WORKTREE_HEAD_REF);
413 done:
414 	if (repo)
415 		got_repo_close(repo);
416 	free(path_got);
417 	free(path_lock);
418 	free(base_commit_id_str);
419 	free(uuidstr);
420 	free(formatstr);
421 	if (err) {
422 		if (fd != -1)
423 			close(fd);
424 		if (*worktree != NULL)
425 			got_worktree_close(*worktree);
426 		*worktree = NULL;
427 	} else
428 		(*worktree)->lockfd = fd;
429 
430 	return err;
431 }
432 
433 const struct got_error *
434 got_worktree_open(struct got_worktree **worktree, const char *path)
435 {
436 	const struct got_error *err = NULL;
437 
438 	do {
439 		err = open_worktree(worktree, path);
440 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT))
441 			return err;
442 		if (*worktree)
443 			return NULL;
444 		path = dirname(path);
445 		if (path == NULL)
446 			return got_error_from_errno2("dirname", path);
447 	} while (!((path[0] == '.' || path[0] == '/') && path[1] == '\0'));
448 
449 	return got_error(GOT_ERR_NOT_WORKTREE);
450 }
451 
452 const struct got_error *
453 got_worktree_close(struct got_worktree *worktree)
454 {
455 	const struct got_error *err = NULL;
456 	free(worktree->root_path);
457 	free(worktree->repo_path);
458 	free(worktree->path_prefix);
459 	free(worktree->base_commit_id);
460 	free(worktree->head_ref_name);
461 	if (worktree->lockfd != -1)
462 		if (close(worktree->lockfd) != 0)
463 			err = got_error_from_errno2("close",
464 			    got_worktree_get_root_path(worktree));
465 	free(worktree);
466 	return err;
467 }
468 
469 const char *
470 got_worktree_get_root_path(struct got_worktree *worktree)
471 {
472 	return worktree->root_path;
473 }
474 
475 const char *
476 got_worktree_get_repo_path(struct got_worktree *worktree)
477 {
478 	return worktree->repo_path;
479 }
480 
481 const char *
482 got_worktree_get_path_prefix(struct got_worktree *worktree)
483 {
484 	return worktree->path_prefix;
485 }
486 
487 const struct got_error *
488 got_worktree_match_path_prefix(int *match, struct got_worktree *worktree,
489     const char *path_prefix)
490 {
491 	char *absprefix = NULL;
492 
493 	if (!got_path_is_absolute(path_prefix)) {
494 		if (asprintf(&absprefix, "/%s", path_prefix) == -1)
495 			return got_error_from_errno("asprintf");
496 	}
497 	*match = (strcmp(absprefix ? absprefix : path_prefix,
498 	    worktree->path_prefix) == 0);
499 	free(absprefix);
500 	return NULL;
501 }
502 
503 const char *
504 got_worktree_get_head_ref_name(struct got_worktree *worktree)
505 {
506 	return worktree->head_ref_name;
507 }
508 
509 const struct got_error *
510 got_worktree_set_head_ref(struct got_worktree *worktree,
511     struct got_reference *head_ref)
512 {
513 	const struct got_error *err = NULL;
514 	char *path_got = NULL, *head_ref_name = NULL;
515 
516 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
517 	    GOT_WORKTREE_GOT_DIR) == -1) {
518 		err = got_error_from_errno("asprintf");
519 		path_got = NULL;
520 		goto done;
521 	}
522 
523 	head_ref_name = strdup(got_ref_get_name(head_ref));
524 	if (head_ref_name == NULL) {
525 		err = got_error_from_errno("strdup");
526 		goto done;
527 	}
528 
529 	err = write_head_ref(path_got, head_ref);
530 	if (err)
531 		goto done;
532 
533 	free(worktree->head_ref_name);
534 	worktree->head_ref_name = head_ref_name;
535 done:
536 	free(path_got);
537 	if (err)
538 		free(head_ref_name);
539 	return err;
540 }
541 
542 struct got_object_id *
543 got_worktree_get_base_commit_id(struct got_worktree *worktree)
544 {
545 	return worktree->base_commit_id;
546 }
547 
548 const struct got_error *
549 got_worktree_set_base_commit_id(struct got_worktree *worktree,
550     struct got_repository *repo, struct got_object_id *commit_id)
551 {
552 	const struct got_error *err;
553 	struct got_object *obj = NULL;
554 	char *id_str = NULL;
555 	char *path_got = NULL;
556 
557 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
558 	    GOT_WORKTREE_GOT_DIR) == -1) {
559 		err = got_error_from_errno("asprintf");
560 		path_got = NULL;
561 		goto done;
562 	}
563 
564 	err = got_object_open(&obj, repo, commit_id);
565 	if (err)
566 		return err;
567 
568 	if (obj->type != GOT_OBJ_TYPE_COMMIT) {
569 		err = got_error(GOT_ERR_OBJ_TYPE);
570 		goto done;
571 	}
572 
573 	/* Record our base commit. */
574 	err = got_object_id_str(&id_str, commit_id);
575 	if (err)
576 		goto done;
577 	err = update_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, id_str);
578 	if (err)
579 		goto done;
580 
581 	free(worktree->base_commit_id);
582 	worktree->base_commit_id = got_object_id_dup(commit_id);
583 	if (worktree->base_commit_id == NULL) {
584 		err = got_error_from_errno("got_object_id_dup");
585 		goto done;
586 	}
587 done:
588 	if (obj)
589 		got_object_close(obj);
590 	free(id_str);
591 	free(path_got);
592 	return err;
593 }
594 
595 static const struct got_error *
596 lock_worktree(struct got_worktree *worktree, int operation)
597 {
598 	if (flock(worktree->lockfd, operation | LOCK_NB) == -1)
599 		return (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
600 		    : got_error_from_errno2("flock",
601 		    got_worktree_get_root_path(worktree)));
602 	return NULL;
603 }
604 
605 static const struct got_error *
606 add_dir_on_disk(struct got_worktree *worktree, const char *path)
607 {
608 	const struct got_error *err = NULL;
609 	char *abspath;
610 
611 	if (asprintf(&abspath, "%s/%s", worktree->root_path, path) == -1)
612 		return got_error_from_errno("asprintf");
613 
614 	err = got_path_mkdir(abspath);
615 	if (err && err->code == GOT_ERR_ERRNO && errno == EEXIST) {
616 		struct stat sb;
617 		err = NULL;
618 		if (lstat(abspath, &sb) == -1) {
619 			err = got_error_from_errno2("lstat", abspath);
620 		} else if (!S_ISDIR(sb.st_mode)) {
621 			/* TODO directory is obstructed; do something */
622 			err = got_error(GOT_ERR_FILE_OBSTRUCTED);
623 		}
624 	}
625 	free(abspath);
626 	return err;
627 }
628 
629 static const struct got_error *
630 check_file_contents_equal(int *same, FILE *f1, FILE *f2)
631 {
632 	const struct got_error *err = NULL;
633 	uint8_t fbuf1[8192];
634 	uint8_t fbuf2[8192];
635 	size_t flen1 = 0, flen2 = 0;
636 
637 	*same = 1;
638 
639 	for (;;) {
640 		flen1 = fread(fbuf1, 1, sizeof(fbuf1), f1);
641 		if (flen1 == 0 && ferror(f1)) {
642 			err = got_error_from_errno("fread");
643 			break;
644 		}
645 		flen2 = fread(fbuf2, 1, sizeof(fbuf2), f2);
646 		if (flen2 == 0 && ferror(f2)) {
647 			err = got_error_from_errno("fread");
648 			break;
649 		}
650 		if (flen1 == 0) {
651 			if (flen2 != 0)
652 				*same = 0;
653 			break;
654 		} else if (flen2 == 0) {
655 			if (flen1 != 0)
656 				*same = 0;
657 			break;
658 		} else if (flen1 == flen2) {
659 			if (memcmp(fbuf1, fbuf2, flen2) != 0) {
660 				*same = 0;
661 				break;
662 			}
663 		} else {
664 			*same = 0;
665 			break;
666 		}
667 	}
668 
669 	return err;
670 }
671 
672 static const struct got_error *
673 check_files_equal(int *same, const char *f1_path, const char *f2_path)
674 {
675 	const struct got_error *err = NULL;
676 	struct stat sb;
677 	size_t size1, size2;
678 	FILE *f1 = NULL, *f2 = NULL;
679 
680 	*same = 1;
681 
682 	if (lstat(f1_path, &sb) != 0) {
683 		err = got_error_from_errno2("lstat", f1_path);
684 		goto done;
685 	}
686 	size1 = sb.st_size;
687 
688 	if (lstat(f2_path, &sb) != 0) {
689 		err = got_error_from_errno2("lstat", f2_path);
690 		goto done;
691 	}
692 	size2 = sb.st_size;
693 
694 	if (size1 != size2) {
695 		*same = 0;
696 		return NULL;
697 	}
698 
699 	f1 = fopen(f1_path, "r");
700 	if (f1 == NULL)
701 		return got_error_from_errno2("open", f1_path);
702 
703 	f2 = fopen(f2_path, "r");
704 	if (f2 == NULL) {
705 		err = got_error_from_errno2("open", f2_path);
706 		goto done;
707 	}
708 
709 	err = check_file_contents_equal(same, f1, f2);
710 done:
711 	if (f1 && fclose(f1) != 0 && err == NULL)
712 		err = got_error_from_errno("fclose");
713 	if (f2 && fclose(f2) != 0 && err == NULL)
714 		err = got_error_from_errno("fclose");
715 
716 	return err;
717 }
718 
719 /*
720  * Perform a 3-way merge where blob_orig acts as the common ancestor,
721  * blob_deriv acts as the first derived version, and the file on disk
722  * acts as the second derived version.
723  */
724 static const struct got_error *
725 merge_blob(int *local_changes_subsumed, struct got_worktree *worktree,
726     struct got_blob_object *blob_orig, const char *ondisk_path,
727     const char *path, uint16_t st_mode, struct got_blob_object *blob_deriv,
728     struct got_object_id *deriv_base_commit_id,
729     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
730     void *progress_arg)
731 {
732 	const struct got_error *err = NULL;
733 	int merged_fd = -1;
734 	FILE *f_deriv = NULL, *f_orig = NULL;
735 	char *blob_deriv_path = NULL, *blob_orig_path = NULL;
736 	char *merged_path = NULL, *base_path = NULL;
737 	char *id_str = NULL;
738 	char *label_deriv = NULL;
739 	int overlapcnt = 0;
740 	char *parent;
741 
742 	*local_changes_subsumed = 0;
743 
744 	parent = dirname(ondisk_path);
745 	if (parent == NULL)
746 		return got_error_from_errno2("dirname", ondisk_path);
747 
748 	if (asprintf(&base_path, "%s/got-merged", parent) == -1)
749 		return got_error_from_errno("asprintf");
750 
751 	err = got_opentemp_named_fd(&merged_path, &merged_fd, base_path);
752 	if (err)
753 		goto done;
754 
755 	free(base_path);
756 	if (asprintf(&base_path, "%s/got-merge-blob-deriv", parent) == -1) {
757 		err = got_error_from_errno("asprintf");
758 		base_path = NULL;
759 		goto done;
760 	}
761 
762 	err = got_opentemp_named(&blob_deriv_path, &f_deriv, base_path);
763 	if (err)
764 		goto done;
765 	err = got_object_blob_dump_to_file(NULL, NULL, NULL, f_deriv,
766 	    blob_deriv);
767 	if (err)
768 		goto done;
769 
770 	free(base_path);
771 	if (asprintf(&base_path, "%s/got-merge-blob-orig", parent) == -1) {
772 		err = got_error_from_errno("asprintf");
773 		base_path = NULL;
774 		goto done;
775 	}
776 
777 	err = got_opentemp_named(&blob_orig_path, &f_orig, base_path);
778 	if (err)
779 		goto done;
780 	if (blob_orig) {
781 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f_orig,
782 		    blob_orig);
783 		if (err)
784 			goto done;
785 	} else {
786 		/*
787 		 * If the file has no blob, this is an "add vs add" conflict,
788 		 * and we simply use an empty ancestor file to make both files
789 		 * appear in the merged result in their entirety.
790 		 */
791 	}
792 
793 	err = got_object_id_str(&id_str, deriv_base_commit_id);
794 	if (err)
795 		goto done;
796 	if (asprintf(&label_deriv, "commit %s", id_str) == -1) {
797 		err = got_error_from_errno("asprintf");
798 		goto done;
799 	}
800 
801 	err = got_merge_diff3(&overlapcnt, merged_fd, blob_deriv_path,
802 	    blob_orig_path, ondisk_path, label_deriv, path);
803 	if (err)
804 		goto done;
805 
806 	err = (*progress_cb)(progress_arg,
807 	    overlapcnt > 0 ? GOT_STATUS_CONFLICT : GOT_STATUS_MERGE, path);
808 	if (err)
809 		goto done;
810 
811 	if (fsync(merged_fd) != 0) {
812 		err = got_error_from_errno("fsync");
813 		goto done;
814 	}
815 
816 	/* Check if a clean merge has subsumed all local changes. */
817 	if (overlapcnt == 0) {
818 		err = check_files_equal(local_changes_subsumed, blob_deriv_path,
819 		    merged_path);
820 		if (err)
821 			goto done;
822 	}
823 
824 	if (chmod(merged_path, st_mode) != 0) {
825 		err = got_error_from_errno2("chmod", merged_path);
826 		goto done;
827 	}
828 
829 	if (rename(merged_path, ondisk_path) != 0) {
830 		err = got_error_from_errno3("rename", merged_path,
831 		    ondisk_path);
832 		unlink(merged_path);
833 		goto done;
834 	}
835 
836 done:
837 	if (merged_fd != -1 && close(merged_fd) != 0 && err == NULL)
838 		err = got_error_from_errno("close");
839 	if (f_deriv && fclose(f_deriv) != 0 && err == NULL)
840 		err = got_error_from_errno("fclose");
841 	if (f_orig && fclose(f_orig) != 0 && err == NULL)
842 		err = got_error_from_errno("fclose");
843 	free(merged_path);
844 	free(base_path);
845 	if (blob_deriv_path) {
846 		unlink(blob_deriv_path);
847 		free(blob_deriv_path);
848 	}
849 	if (blob_orig_path) {
850 		unlink(blob_orig_path);
851 		free(blob_orig_path);
852 	}
853 	free(id_str);
854 	free(label_deriv);
855 	return err;
856 }
857 
858 static const struct got_error *
859 update_blob_fileindex_entry(struct got_worktree *worktree,
860     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
861     const char *ondisk_path, const char *path, struct got_blob_object *blob,
862     int update_timestamps)
863 {
864 	const struct got_error *err = NULL;
865 
866 	if (ie == NULL)
867 		ie = got_fileindex_entry_get(fileindex, path);
868 	if (ie)
869 		err = got_fileindex_entry_update(ie, ondisk_path,
870 		    blob->id.sha1, worktree->base_commit_id->sha1,
871 		    update_timestamps);
872 	else {
873 		struct got_fileindex_entry *new_ie;
874 		err = got_fileindex_entry_alloc(&new_ie, ondisk_path,
875 		    path, blob->id.sha1, worktree->base_commit_id->sha1);
876 		if (!err)
877 			err = got_fileindex_entry_add(fileindex, new_ie);
878 	}
879 	return err;
880 }
881 
882 static const struct got_error *
883 install_blob(struct got_worktree *worktree, const char *ondisk_path,
884    const char *path, uint16_t te_mode, uint16_t st_mode,
885    struct got_blob_object *blob, int restoring_missing_file,
886    int reverting_versioned_file, struct got_repository *repo,
887    got_worktree_checkout_cb progress_cb, void *progress_arg)
888 {
889 	const struct got_error *err = NULL;
890 	int fd = -1;
891 	size_t len, hdrlen;
892 	int update = 0;
893 	char *tmppath = NULL;
894 
895 	fd = open(ondisk_path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
896 	    GOT_DEFAULT_FILE_MODE);
897 	if (fd == -1) {
898 		if (errno == ENOENT) {
899 			char *parent = dirname(path);
900 			if (parent == NULL)
901 				return got_error_from_errno2("dirname", path);
902 			err = add_dir_on_disk(worktree, parent);
903 			if (err)
904 				return err;
905 			fd = open(ondisk_path,
906 			    O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
907 			    GOT_DEFAULT_FILE_MODE);
908 			if (fd == -1)
909 				return got_error_from_errno2("open",
910 				    ondisk_path);
911 		} else if (errno == EEXIST) {
912 			if (!S_ISREG(st_mode)) {
913 				/* TODO file is obstructed; do something */
914 				err = got_error(GOT_ERR_FILE_OBSTRUCTED);
915 				goto done;
916 			} else {
917 				err = got_opentemp_named_fd(&tmppath, &fd,
918 				    ondisk_path);
919 				if (err)
920 					goto done;
921 				update = 1;
922 			}
923 		} else
924 			return got_error_from_errno2("open", ondisk_path);
925 	}
926 
927 	if (restoring_missing_file)
928 		err = (*progress_cb)(progress_arg, GOT_STATUS_MISSING, path);
929 	else if (reverting_versioned_file)
930 		err = (*progress_cb)(progress_arg, GOT_STATUS_REVERT, path);
931 	else
932 		err = (*progress_cb)(progress_arg,
933 		    update ? GOT_STATUS_UPDATE : GOT_STATUS_ADD, path);
934 	if (err)
935 		goto done;
936 
937 	hdrlen = got_object_blob_get_hdrlen(blob);
938 	do {
939 		const uint8_t *buf = got_object_blob_get_read_buf(blob);
940 		err = got_object_blob_read_block(&len, blob);
941 		if (err)
942 			break;
943 		if (len > 0) {
944 			/* Skip blob object header first time around. */
945 			ssize_t outlen = write(fd, buf + hdrlen, len - hdrlen);
946 			if (outlen == -1) {
947 				err = got_error_from_errno("write");
948 				goto done;
949 			} else if (outlen != len - hdrlen) {
950 				err = got_error(GOT_ERR_IO);
951 				goto done;
952 			}
953 			hdrlen = 0;
954 		}
955 	} while (len != 0);
956 
957 	if (fsync(fd) != 0) {
958 		err = got_error_from_errno("fsync");
959 		goto done;
960 	}
961 
962 	if (update) {
963 		if (rename(tmppath, ondisk_path) != 0) {
964 			err = got_error_from_errno3("rename", tmppath,
965 			    ondisk_path);
966 			unlink(tmppath);
967 			goto done;
968 		}
969 	}
970 
971 	if (te_mode & S_IXUSR) {
972 		if (chmod(ondisk_path, st_mode | S_IXUSR) == -1) {
973 			err = got_error_from_errno2("chmod", ondisk_path);
974 			goto done;
975 		}
976 	} else {
977 		if (chmod(ondisk_path, st_mode & ~S_IXUSR) == -1) {
978 			err = got_error_from_errno2("chmod", ondisk_path);
979 			goto done;
980 		}
981 	}
982 
983 done:
984 	if (fd != -1 && close(fd) != 0 && err == NULL)
985 		err = got_error_from_errno("close");
986 	free(tmppath);
987 	return err;
988 }
989 
990 /* Upgrade STATUS_MODIFY to STATUS_CONFLICT if a conflict marker is found. */
991 static const struct got_error *
992 get_modified_file_content_status(unsigned char *status, FILE *f)
993 {
994 	const struct got_error *err = NULL;
995 	const char *markers[3] = {
996 		GOT_DIFF_CONFLICT_MARKER_BEGIN,
997 		GOT_DIFF_CONFLICT_MARKER_SEP,
998 		GOT_DIFF_CONFLICT_MARKER_END
999 	};
1000 	int i = 0;
1001 	char *line;
1002 	size_t len;
1003 	const char delim[3] = {'\0', '\0', '\0'};
1004 
1005 	while (*status == GOT_STATUS_MODIFY) {
1006 		line = fparseln(f, &len, NULL, delim, 0);
1007 		if (line == NULL) {
1008 			if (feof(f))
1009 				break;
1010 			err = got_ferror(f, GOT_ERR_IO);
1011 			break;
1012 		}
1013 
1014 		if (strncmp(line, markers[i], strlen(markers[i])) == 0) {
1015 			if (strcmp(markers[i], GOT_DIFF_CONFLICT_MARKER_END)
1016 			    == 0)
1017 				*status = GOT_STATUS_CONFLICT;
1018 			else
1019 				i++;
1020 		}
1021 	}
1022 
1023 	return err;
1024 }
1025 
1026 static int
1027 stat_info_differs(struct got_fileindex_entry *ie, struct stat *sb)
1028 {
1029 	return !(ie->ctime_sec == sb->st_ctime &&
1030 	    ie->ctime_nsec == sb->st_ctimensec &&
1031 	    ie->mtime_sec == sb->st_mtime &&
1032 	    ie->mtime_nsec == sb->st_mtimensec &&
1033 	    ie->size == (sb->st_size & 0xffffffff));
1034 }
1035 
1036 static const struct got_error *
1037 get_file_status(unsigned char *status, struct stat *sb,
1038     struct got_fileindex_entry *ie, const char *abspath,
1039     struct got_repository *repo)
1040 {
1041 	const struct got_error *err = NULL;
1042 	struct got_object_id id;
1043 	size_t hdrlen;
1044 	FILE *f = NULL;
1045 	uint8_t fbuf[8192];
1046 	struct got_blob_object *blob = NULL;
1047 	size_t flen, blen;
1048 
1049 	*status = GOT_STATUS_NO_CHANGE;
1050 
1051 	if (lstat(abspath, sb) == -1) {
1052 		if (errno == ENOENT) {
1053 			if (got_fileindex_entry_has_file_on_disk(ie))
1054 				*status = GOT_STATUS_MISSING;
1055 			else
1056 				*status = GOT_STATUS_DELETE;
1057 			return NULL;
1058 		}
1059 		return got_error_from_errno2("lstat", abspath);
1060 	}
1061 
1062 	if (!S_ISREG(sb->st_mode)) {
1063 		*status = GOT_STATUS_OBSTRUCTED;
1064 		return NULL;
1065 	}
1066 
1067 	if (!got_fileindex_entry_has_file_on_disk(ie)) {
1068 		*status = GOT_STATUS_DELETE;
1069 		return NULL;
1070 	} else if (!got_fileindex_entry_has_blob(ie)) {
1071 		*status = GOT_STATUS_ADD;
1072 		return NULL;
1073 	}
1074 
1075 	if (!stat_info_differs(ie, sb))
1076 		return NULL;
1077 
1078 	memcpy(id.sha1, ie->blob_sha1, sizeof(id.sha1));
1079 	err = got_object_open_as_blob(&blob, repo, &id, sizeof(fbuf));
1080 	if (err)
1081 		return err;
1082 
1083 	f = fopen(abspath, "r");
1084 	if (f == NULL) {
1085 		err = got_error_from_errno2("fopen", abspath);
1086 		goto done;
1087 	}
1088 	hdrlen = got_object_blob_get_hdrlen(blob);
1089 	for (;;) {
1090 		const uint8_t *bbuf = got_object_blob_get_read_buf(blob);
1091 		err = got_object_blob_read_block(&blen, blob);
1092 		if (err)
1093 			goto done;
1094 		/* Skip length of blob object header first time around. */
1095 		flen = fread(fbuf, 1, sizeof(fbuf) - hdrlen, f);
1096 		if (flen == 0 && ferror(f)) {
1097 			err = got_error_from_errno("fread");
1098 			goto done;
1099 		}
1100 		if (blen == 0) {
1101 			if (flen != 0)
1102 				*status = GOT_STATUS_MODIFY;
1103 			break;
1104 		} else if (flen == 0) {
1105 			if (blen != 0)
1106 				*status = GOT_STATUS_MODIFY;
1107 			break;
1108 		} else if (blen - hdrlen == flen) {
1109 			/* Skip blob object header first time around. */
1110 			if (memcmp(bbuf + hdrlen, fbuf, flen) != 0) {
1111 				*status = GOT_STATUS_MODIFY;
1112 				break;
1113 			}
1114 		} else {
1115 			*status = GOT_STATUS_MODIFY;
1116 			break;
1117 		}
1118 		hdrlen = 0;
1119 	}
1120 
1121 	if (*status == GOT_STATUS_MODIFY) {
1122 		rewind(f);
1123 		err = get_modified_file_content_status(status, f);
1124 	}
1125 done:
1126 	if (blob)
1127 		got_object_blob_close(blob);
1128 	if (f)
1129 		fclose(f);
1130 	return err;
1131 }
1132 
1133 /*
1134  * Update timestamps in the file index if a file is unmodified and
1135  * we had to run a full content comparison to find out.
1136  */
1137 static const struct got_error *
1138 sync_timestamps(char *ondisk_path, unsigned char status,
1139     struct got_fileindex_entry *ie, struct stat *sb)
1140 {
1141 	if (status == GOT_STATUS_NO_CHANGE && stat_info_differs(ie, sb))
1142 		return got_fileindex_entry_update(ie, ondisk_path,
1143 		    ie->blob_sha1, ie->commit_sha1, 1);
1144 
1145 	return NULL;
1146 }
1147 
1148 static const struct got_error *
1149 update_blob(struct got_worktree *worktree,
1150     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
1151     struct got_tree_entry *te, const char *path,
1152     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1153     void *progress_arg)
1154 {
1155 	const struct got_error *err = NULL;
1156 	struct got_blob_object *blob = NULL;
1157 	char *ondisk_path;
1158 	unsigned char status = GOT_STATUS_NO_CHANGE;
1159 	struct stat sb;
1160 
1161 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
1162 		return got_error_from_errno("asprintf");
1163 
1164 	if (ie) {
1165 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1166 		if (err)
1167 			goto done;
1168 		if (status == GOT_STATUS_MISSING || status == GOT_STATUS_DELETE)
1169 			sb.st_mode = got_fileindex_perms_to_st(ie);
1170 	} else
1171 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
1172 
1173 	if (status == GOT_STATUS_OBSTRUCTED) {
1174 		err = (*progress_cb)(progress_arg, status, path);
1175 		goto done;
1176 	}
1177 
1178 	if (ie && status != GOT_STATUS_MISSING) {
1179 		if (got_fileindex_entry_has_commit(ie) &&
1180 		    memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
1181 		    SHA1_DIGEST_LENGTH) == 0) {
1182 			err = sync_timestamps(ondisk_path, status, ie, &sb);
1183 			if (err)
1184 				goto done;
1185 			err = (*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
1186 			    path);
1187 			goto done;
1188 		}
1189 		if (got_fileindex_entry_has_blob(ie) &&
1190 		    memcmp(ie->blob_sha1, te->id->sha1,
1191 		    SHA1_DIGEST_LENGTH) == 0) {
1192 			err = sync_timestamps(ondisk_path, status, ie, &sb);
1193 			goto done;
1194 		}
1195 	}
1196 
1197 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
1198 	if (err)
1199 		goto done;
1200 
1201 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_ADD) {
1202 		int update_timestamps;
1203 		struct got_blob_object *blob2 = NULL;
1204 		if (got_fileindex_entry_has_blob(ie)) {
1205 			struct got_object_id id2;
1206 			memcpy(id2.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1207 			err = got_object_open_as_blob(&blob2, repo, &id2, 8192);
1208 			if (err)
1209 				goto done;
1210 		}
1211 		err = merge_blob(&update_timestamps, worktree, blob2,
1212 		    ondisk_path, path, sb.st_mode, blob,
1213 		    worktree->base_commit_id, repo,
1214 		    progress_cb, progress_arg);
1215 		if (blob2)
1216 			got_object_blob_close(blob2);
1217 		/*
1218 		 * Do not update timestamps of files with local changes.
1219 		 * Otherwise, a future status walk would treat them as
1220 		 * unmodified files again.
1221 		 */
1222 		err = got_fileindex_entry_update(ie, ondisk_path,
1223 		    blob->id.sha1, worktree->base_commit_id->sha1,
1224 		    update_timestamps);
1225 	} else if (status == GOT_STATUS_DELETE) {
1226 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, path);
1227 		if (err)
1228 			goto done;
1229 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1230 		    ondisk_path, path, blob, 0);
1231 		if (err)
1232 			goto done;
1233 	} else {
1234 		err = install_blob(worktree, ondisk_path, path, te->mode,
1235 		    sb.st_mode, blob, status == GOT_STATUS_MISSING, 0,
1236 		    repo, progress_cb, progress_arg);
1237 		if (err)
1238 			goto done;
1239 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1240 		    ondisk_path, path, blob, 1);
1241 		if (err)
1242 			goto done;
1243 	}
1244 	got_object_blob_close(blob);
1245 done:
1246 	free(ondisk_path);
1247 	return err;
1248 }
1249 
1250 static const struct got_error *
1251 remove_ondisk_file(const char *root_path, const char *path)
1252 {
1253 	const struct got_error *err = NULL;
1254 	char *ondisk_path = NULL;
1255 
1256 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
1257 		return got_error_from_errno("asprintf");
1258 
1259 	if (unlink(ondisk_path) == -1) {
1260 		if (errno != ENOENT)
1261 			err = got_error_from_errno2("unlink", ondisk_path);
1262 	} else {
1263 		char *parent = dirname(ondisk_path);
1264 		while (parent && strcmp(parent, root_path) != 0) {
1265 			if (rmdir(parent) == -1) {
1266 				if (errno != ENOTEMPTY)
1267 					err = got_error_from_errno2("rmdir",
1268 					    parent);
1269 				break;
1270 			}
1271 			parent = dirname(parent);
1272 		}
1273 	}
1274 	free(ondisk_path);
1275 	return err;
1276 }
1277 
1278 static const struct got_error *
1279 delete_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
1280     struct got_fileindex_entry *ie, struct got_repository *repo,
1281     got_worktree_checkout_cb progress_cb, void *progress_arg)
1282 {
1283 	const struct got_error *err = NULL;
1284 	unsigned char status;
1285 	struct stat sb;
1286 	char *ondisk_path;
1287 
1288 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, ie->path)
1289 	    == -1)
1290 		return got_error_from_errno("asprintf");
1291 
1292 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1293 	if (err)
1294 		return err;
1295 
1296 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_CONFLICT ||
1297 	    status == GOT_STATUS_ADD) {
1298 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, ie->path);
1299 		if (err)
1300 			return err;
1301 		/*
1302 		 * Preserve the working file and change the deleted blob's
1303 		 * entry into a schedule-add entry.
1304 		 */
1305 		err = got_fileindex_entry_update(ie, ondisk_path, NULL, NULL,
1306 		    0);
1307 		if (err)
1308 			return err;
1309 	} else {
1310 		err = (*progress_cb)(progress_arg, GOT_STATUS_DELETE, ie->path);
1311 		if (err)
1312 			return err;
1313 		if (status == GOT_STATUS_NO_CHANGE) {
1314 			err = remove_ondisk_file(worktree->root_path, ie->path);
1315 			if (err)
1316 				return err;
1317 		}
1318 		got_fileindex_entry_remove(fileindex, ie);
1319 	}
1320 
1321 	return err;
1322 }
1323 
1324 struct diff_cb_arg {
1325     struct got_fileindex *fileindex;
1326     struct got_worktree *worktree;
1327     struct got_repository *repo;
1328     got_worktree_checkout_cb progress_cb;
1329     void *progress_arg;
1330     got_worktree_cancel_cb cancel_cb;
1331     void *cancel_arg;
1332 };
1333 
1334 static const struct got_error *
1335 diff_old_new(void *arg, struct got_fileindex_entry *ie,
1336     struct got_tree_entry *te, const char *parent_path)
1337 {
1338 	struct diff_cb_arg *a = arg;
1339 
1340 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1341 		return got_error(GOT_ERR_CANCELLED);
1342 
1343 	return update_blob(a->worktree, a->fileindex, ie, te,
1344 	    ie->path, a->repo, a->progress_cb, a->progress_arg);
1345 }
1346 
1347 static const struct got_error *
1348 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1349 {
1350 	struct diff_cb_arg *a = arg;
1351 
1352 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1353 		return got_error(GOT_ERR_CANCELLED);
1354 
1355 	return delete_blob(a->worktree, a->fileindex, ie,
1356 	    a->repo, a->progress_cb, a->progress_arg);
1357 }
1358 
1359 static const struct got_error *
1360 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
1361 {
1362 	struct diff_cb_arg *a = arg;
1363 	const struct got_error *err;
1364 	char *path;
1365 
1366 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1367 		return got_error(GOT_ERR_CANCELLED);
1368 
1369 	if (asprintf(&path, "%s%s%s", parent_path,
1370 	    parent_path[0] ? "/" : "", te->name)
1371 	    == -1)
1372 		return got_error_from_errno("asprintf");
1373 
1374 	if (S_ISDIR(te->mode))
1375 		err = add_dir_on_disk(a->worktree, path);
1376 	else
1377 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
1378 		    a->repo, a->progress_cb, a->progress_arg);
1379 
1380 	free(path);
1381 	return err;
1382 }
1383 
1384 static const struct got_error *
1385 get_ref_name(char **refname, struct got_worktree *worktree, const char *prefix)
1386 {
1387 	const struct got_error *err = NULL;
1388 	char *uuidstr = NULL;
1389 	uint32_t uuid_status;
1390 
1391 	*refname = NULL;
1392 
1393 	uuid_to_string(&worktree->uuid, &uuidstr, &uuid_status);
1394 	if (uuid_status != uuid_s_ok)
1395 		return got_error_uuid(uuid_status);
1396 
1397 	if (asprintf(refname, "%s-%s", prefix, uuidstr)
1398 	    == -1) {
1399 		err = got_error_from_errno("asprintf");
1400 		*refname = NULL;
1401 	}
1402 	free(uuidstr);
1403 	return err;
1404 }
1405 
1406 const struct got_error *
1407 got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
1408 {
1409 	return get_ref_name(refname, worktree, GOT_WORKTREE_BASE_REF_PREFIX);
1410 }
1411 
1412 static const struct got_error *
1413 get_rebase_tmp_ref_name(char **refname, struct got_worktree *worktree)
1414 {
1415 	return get_ref_name(refname, worktree,
1416 	    GOT_WORKTREE_REBASE_TMP_REF_PREFIX);
1417 }
1418 
1419 static const struct got_error *
1420 get_newbase_symref_name(char **refname, struct got_worktree *worktree)
1421 {
1422 	return get_ref_name(refname, worktree, GOT_WORKTREE_NEWBASE_REF_PREFIX);
1423 }
1424 
1425 static const struct got_error *
1426 get_rebase_branch_symref_name(char **refname, struct got_worktree *worktree)
1427 {
1428 	return get_ref_name(refname, worktree,
1429 	    GOT_WORKTREE_REBASE_BRANCH_REF_PREFIX);
1430 }
1431 
1432 static const struct got_error *
1433 get_rebase_commit_ref_name(char **refname, struct got_worktree *worktree)
1434 {
1435 	return get_ref_name(refname, worktree,
1436 	    GOT_WORKTREE_REBASE_COMMIT_REF_PREFIX);
1437 }
1438 
1439 static const struct got_error *
1440 get_histedit_tmp_ref_name(char **refname, struct got_worktree *worktree)
1441 {
1442 	return get_ref_name(refname, worktree,
1443 	    GOT_WORKTREE_HISTEDIT_TMP_REF_PREFIX);
1444 }
1445 
1446 static const struct got_error *
1447 get_histedit_branch_symref_name(char **refname, struct got_worktree *worktree)
1448 {
1449 	return get_ref_name(refname, worktree,
1450 	    GOT_WORKTREE_HISTEDIT_BRANCH_REF_PREFIX);
1451 }
1452 
1453 static const struct got_error *
1454 get_histedit_base_commit_ref_name(char **refname, struct got_worktree *worktree)
1455 {
1456 	return get_ref_name(refname, worktree,
1457 	    GOT_WORKTREE_HISTEDIT_BASE_COMMIT_REF_PREFIX);
1458 }
1459 
1460 static const struct got_error *
1461 get_histedit_commit_ref_name(char **refname, struct got_worktree *worktree)
1462 {
1463 	return get_ref_name(refname, worktree,
1464 	    GOT_WORKTREE_HISTEDIT_COMMIT_REF_PREFIX);
1465 }
1466 
1467 const struct got_error *
1468 got_worktree_get_histedit_list_path(char **path, struct got_worktree *worktree)
1469 {
1470 	if (asprintf(path, "%s/%s/%s", worktree->root_path,
1471 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_HISTEDIT_LIST) == -1) {
1472 		*path = NULL;
1473 		return got_error_from_errno("asprintf");
1474 	}
1475 	return NULL;
1476 }
1477 
1478 /*
1479  * Prevent Git's garbage collector from deleting our base commit by
1480  * setting a reference to our base commit's ID.
1481  */
1482 static const struct got_error *
1483 ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
1484 {
1485 	const struct got_error *err = NULL;
1486 	struct got_reference *ref = NULL;
1487 	char *refname;
1488 
1489 	err = got_worktree_get_base_ref_name(&refname, worktree);
1490 	if (err)
1491 		return err;
1492 
1493 	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
1494 	if (err)
1495 		goto done;
1496 
1497 	err = got_ref_write(ref, repo);
1498 done:
1499 	free(refname);
1500 	if (ref)
1501 		got_ref_close(ref);
1502 	return err;
1503 }
1504 
1505 static const struct got_error *
1506 get_fileindex_path(char **fileindex_path, struct got_worktree *worktree)
1507 {
1508 	const struct got_error *err = NULL;
1509 
1510 	if (asprintf(fileindex_path, "%s/%s/%s", worktree->root_path,
1511 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1512 		err = got_error_from_errno("asprintf");
1513 		*fileindex_path = NULL;
1514 	}
1515 	return err;
1516 }
1517 
1518 
1519 static const struct got_error *
1520 open_fileindex(struct got_fileindex **fileindex, char **fileindex_path,
1521    struct got_worktree *worktree)
1522 {
1523 	const struct got_error *err = NULL;
1524 	FILE *index = NULL;
1525 
1526 	*fileindex_path = NULL;
1527 	*fileindex = got_fileindex_alloc();
1528 	if (*fileindex == NULL)
1529 		return got_error_from_errno("got_fileindex_alloc");
1530 
1531 	err = get_fileindex_path(fileindex_path, worktree);
1532 	if (err)
1533 		goto done;
1534 
1535 	index = fopen(*fileindex_path, "rb");
1536 	if (index == NULL) {
1537 		if (errno != ENOENT)
1538 			err = got_error_from_errno2("fopen", *fileindex_path);
1539 	} else {
1540 		err = got_fileindex_read(*fileindex, index);
1541 		if (fclose(index) != 0 && err == NULL)
1542 			err = got_error_from_errno("fclose");
1543 	}
1544 done:
1545 	if (err) {
1546 		free(*fileindex_path);
1547 		*fileindex_path = NULL;
1548 		got_fileindex_free(*fileindex);
1549 		*fileindex = NULL;
1550 	}
1551 	return err;
1552 }
1553 
1554 struct bump_base_commit_id_arg {
1555 	struct got_object_id *base_commit_id;
1556 	const char *path;
1557 	size_t path_len;
1558 	const char *entry_name;
1559 	got_worktree_checkout_cb progress_cb;
1560 	void *progress_arg;
1561 };
1562 
1563 /* Bump base commit ID of all files within an updated part of the work tree. */
1564 static const struct got_error *
1565 bump_base_commit_id(void *arg, struct got_fileindex_entry *ie)
1566 {
1567 	const struct got_error *err;
1568 	struct bump_base_commit_id_arg *a = arg;
1569 
1570 	if (a->entry_name) {
1571 		if (strcmp(ie->path, a->path) != 0)
1572 			return NULL;
1573 	} else if (!got_path_is_child(ie->path, a->path, a->path_len))
1574 		return NULL;
1575 
1576 	if (memcmp(ie->commit_sha1, a->base_commit_id->sha1,
1577 	    SHA1_DIGEST_LENGTH) == 0)
1578 		return NULL;
1579 
1580 	if (a->progress_cb) {
1581 		err = (*a->progress_cb)(a->progress_arg, GOT_STATUS_BUMP_BASE,
1582 		    ie->path);
1583 		if (err)
1584 			return err;
1585 	}
1586 	memcpy(ie->commit_sha1, a->base_commit_id->sha1, SHA1_DIGEST_LENGTH);
1587 	return NULL;
1588 }
1589 
1590 static const struct got_error *
1591 sync_fileindex(struct got_fileindex *fileindex, const char *fileindex_path)
1592 {
1593 	const struct got_error *err = NULL;
1594 	char *new_fileindex_path = NULL;
1595 	FILE *new_index = NULL;
1596 
1597 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1598 	    fileindex_path);
1599 	if (err)
1600 		goto done;
1601 
1602 	err = got_fileindex_write(fileindex, new_index);
1603 	if (err)
1604 		goto done;
1605 
1606 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1607 		err = got_error_from_errno3("rename", new_fileindex_path,
1608 		    fileindex_path);
1609 		unlink(new_fileindex_path);
1610 	}
1611 done:
1612 	if (new_index)
1613 		fclose(new_index);
1614 	free(new_fileindex_path);
1615 	return err;
1616 }
1617 
1618 static const struct got_error *
1619 find_tree_entry_for_checkout(int *entry_type, char **tree_relpath,
1620     struct got_object_id **tree_id, const char *wt_relpath,
1621     struct got_worktree *worktree, struct got_repository *repo)
1622 {
1623 	const struct got_error *err = NULL;
1624 	struct got_object_id *id = NULL;
1625 	char *in_repo_path = NULL;
1626 	int is_root_wt = got_path_is_root_dir(worktree->path_prefix);
1627 
1628 	*entry_type = GOT_OBJ_TYPE_ANY;
1629 	*tree_relpath = NULL;
1630 	*tree_id = NULL;
1631 
1632 	if (wt_relpath[0] == '\0') {
1633 		/* Check out all files within the work tree. */
1634 		*entry_type = GOT_OBJ_TYPE_TREE;
1635 		*tree_relpath = strdup("");
1636 		if (*tree_relpath == NULL) {
1637 			err = got_error_from_errno("strdup");
1638 			goto done;
1639 		}
1640 		err = got_object_id_by_path(tree_id, repo,
1641 		    worktree->base_commit_id, worktree->path_prefix);
1642 		if (err)
1643 			goto done;
1644 		return NULL;
1645 	}
1646 
1647 	/* Check out a subset of files in the work tree. */
1648 
1649 	if (asprintf(&in_repo_path, "%s%s%s", worktree->path_prefix,
1650 	    is_root_wt ? "" : "/", wt_relpath) == -1) {
1651 		err = got_error_from_errno("asprintf");
1652 		goto done;
1653 	}
1654 
1655 	err = got_object_id_by_path(&id, repo, worktree->base_commit_id,
1656 	    in_repo_path);
1657 	if (err)
1658 		goto done;
1659 
1660 	free(in_repo_path);
1661 	in_repo_path = NULL;
1662 
1663 	err = got_object_get_type(entry_type, repo, id);
1664 	if (err)
1665 		goto done;
1666 
1667 	if (*entry_type == GOT_OBJ_TYPE_BLOB) {
1668 		/* Check out a single file. */
1669 		if (strchr(wt_relpath, '/')  == NULL) {
1670 			/* Check out a single file in work tree's root dir. */
1671 			in_repo_path = strdup(worktree->path_prefix);
1672 			if (in_repo_path == NULL) {
1673 				err = got_error_from_errno("strdup");
1674 				goto done;
1675 			}
1676 			*tree_relpath = strdup("");
1677 			if (*tree_relpath == NULL) {
1678 				err = got_error_from_errno("strdup");
1679 				goto done;
1680 			}
1681 		} else {
1682 			/* Check out a single file in a subdirectory. */
1683 			err = got_path_dirname(tree_relpath, wt_relpath);
1684 			if (err)
1685 				return err;
1686 			if (asprintf(&in_repo_path, "%s%s%s",
1687 			    worktree->path_prefix, is_root_wt ? "" : "/",
1688 			    *tree_relpath) == -1) {
1689 				err = got_error_from_errno("asprintf");
1690 				goto done;
1691 			}
1692 		}
1693 		err = got_object_id_by_path(tree_id, repo,
1694 		    worktree->base_commit_id, in_repo_path);
1695 	} else {
1696 		/* Check out all files within a subdirectory. */
1697 		*tree_id = got_object_id_dup(id);
1698 		if (*tree_id == NULL) {
1699 			err = got_error_from_errno("got_object_id_dup");
1700 			goto done;
1701 		}
1702 		*tree_relpath = strdup(wt_relpath);
1703 		if (*tree_relpath == NULL) {
1704 			err = got_error_from_errno("strdup");
1705 			goto done;
1706 		}
1707 	}
1708 done:
1709 	free(id);
1710 	free(in_repo_path);
1711 	if (err) {
1712 		*entry_type = GOT_OBJ_TYPE_ANY;
1713 		free(*tree_relpath);
1714 		*tree_relpath = NULL;
1715 		free(*tree_id);
1716 		*tree_id = NULL;
1717 	}
1718 	return err;
1719 }
1720 
1721 static const struct got_error *
1722 checkout_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
1723     const char *relpath, struct got_object_id *tree_id, const char *entry_name,
1724     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1725     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1726 {
1727 	const struct got_error *err = NULL;
1728 	struct got_commit_object *commit = NULL;
1729 	struct got_tree_object *tree = NULL;
1730 	struct got_fileindex_diff_tree_cb diff_cb;
1731 	struct diff_cb_arg arg;
1732 
1733 	err = ref_base_commit(worktree, repo);
1734 	if (err)
1735 		goto done;
1736 
1737 	err = got_object_open_as_commit(&commit, repo,
1738 	   worktree->base_commit_id);
1739 	if (err)
1740 		goto done;
1741 
1742 	err = got_object_open_as_tree(&tree, repo, tree_id);
1743 	if (err)
1744 		goto done;
1745 
1746 	if (entry_name &&
1747 	    got_object_tree_find_entry(tree, entry_name) == NULL) {
1748 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
1749 		goto done;
1750 	}
1751 
1752 	diff_cb.diff_old_new = diff_old_new;
1753 	diff_cb.diff_old = diff_old;
1754 	diff_cb.diff_new = diff_new;
1755 	arg.fileindex = fileindex;
1756 	arg.worktree = worktree;
1757 	arg.repo = repo;
1758 	arg.progress_cb = progress_cb;
1759 	arg.progress_arg = progress_arg;
1760 	arg.cancel_cb = cancel_cb;
1761 	arg.cancel_arg = cancel_arg;
1762 	err = got_fileindex_diff_tree(fileindex, tree, relpath,
1763 	    entry_name, repo, &diff_cb, &arg);
1764 done:
1765 	if (tree)
1766 		got_object_tree_close(tree);
1767 	if (commit)
1768 		got_object_commit_close(commit);
1769 	return err;
1770 }
1771 
1772 const struct got_error *
1773 got_worktree_checkout_files(struct got_worktree *worktree,
1774     struct got_pathlist_head *paths, struct got_repository *repo,
1775     got_worktree_checkout_cb progress_cb, void *progress_arg,
1776     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1777 {
1778 	const struct got_error *err = NULL, *sync_err, *unlockerr;
1779 	struct got_commit_object *commit = NULL;
1780 	struct got_tree_object *tree = NULL;
1781 	struct got_fileindex *fileindex = NULL;
1782 	char *fileindex_path = NULL;
1783 	struct got_pathlist_entry *pe;
1784 	struct tree_path_data {
1785 		SIMPLEQ_ENTRY(tree_path_data) entry;
1786 		struct got_object_id *tree_id;
1787 		int entry_type;
1788 		char *relpath;
1789 		char *entry_name;
1790 	} *tpd = NULL;
1791 	SIMPLEQ_HEAD(tree_paths, tree_path_data) tree_paths;
1792 
1793 	SIMPLEQ_INIT(&tree_paths);
1794 
1795 	err = lock_worktree(worktree, LOCK_EX);
1796 	if (err)
1797 		return err;
1798 
1799 	/* Map all specified paths to in-repository trees. */
1800 	TAILQ_FOREACH(pe, paths, entry) {
1801 		tpd = malloc(sizeof(*tpd));
1802 		if (tpd == NULL) {
1803 			err = got_error_from_errno("malloc");
1804 			goto done;
1805 		}
1806 
1807 		err = find_tree_entry_for_checkout(&tpd->entry_type,
1808 		    &tpd->relpath, &tpd->tree_id, pe->path, worktree, repo);
1809 		if (err) {
1810 			free(tpd);
1811 			goto done;
1812 		}
1813 
1814 		if (tpd->entry_type == GOT_OBJ_TYPE_BLOB) {
1815 			err = got_path_basename(&tpd->entry_name, pe->path);
1816 			if (err) {
1817 				free(tpd->relpath);
1818 				free(tpd->tree_id);
1819 				free(tpd);
1820 				goto done;
1821 			}
1822 		} else
1823 			tpd->entry_name = NULL;
1824 
1825 		SIMPLEQ_INSERT_TAIL(&tree_paths, tpd, entry);
1826 	}
1827 
1828 	/*
1829 	 * Read the file index.
1830 	 * Checking out files is supposed to be an idempotent operation.
1831 	 * If the on-disk file index is incomplete we will try to complete it.
1832 	 */
1833 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1834 	if (err)
1835 		goto done;
1836 
1837 	tpd = SIMPLEQ_FIRST(&tree_paths);
1838 	TAILQ_FOREACH(pe, paths, entry) {
1839 		struct bump_base_commit_id_arg bbc_arg;
1840 
1841 		err = checkout_files(worktree, fileindex, tpd->relpath,
1842 		    tpd->tree_id, tpd->entry_name, repo,
1843 		    progress_cb, progress_arg, cancel_cb, cancel_arg);
1844 		if (err)
1845 			break;
1846 
1847 		bbc_arg.base_commit_id = worktree->base_commit_id;
1848 		bbc_arg.entry_name = tpd->entry_name;
1849 		bbc_arg.path = pe->path;
1850 		bbc_arg.path_len = strlen(pe->path);
1851 		bbc_arg.progress_cb = progress_cb;
1852 		bbc_arg.progress_arg = progress_arg;
1853 		err = got_fileindex_for_each_entry_safe(fileindex,
1854 		    bump_base_commit_id, &bbc_arg);
1855 		if (err)
1856 			break;
1857 
1858 		tpd = SIMPLEQ_NEXT(tpd, entry);
1859 	}
1860 	sync_err = sync_fileindex(fileindex, fileindex_path);
1861 	if (sync_err && err == NULL)
1862 		err = sync_err;
1863 done:
1864 	free(fileindex_path);
1865 	if (tree)
1866 		got_object_tree_close(tree);
1867 	if (commit)
1868 		got_object_commit_close(commit);
1869 	if (fileindex)
1870 		got_fileindex_free(fileindex);
1871 	while (!SIMPLEQ_EMPTY(&tree_paths)) {
1872 		tpd = SIMPLEQ_FIRST(&tree_paths);
1873 		SIMPLEQ_REMOVE_HEAD(&tree_paths, entry);
1874 		free(tpd->relpath);
1875 		free(tpd->tree_id);
1876 		free(tpd);
1877 	}
1878 	unlockerr = lock_worktree(worktree, LOCK_SH);
1879 	if (unlockerr && err == NULL)
1880 		err = unlockerr;
1881 	return err;
1882 }
1883 
1884 struct merge_file_cb_arg {
1885     struct got_worktree *worktree;
1886     struct got_fileindex *fileindex;
1887     got_worktree_checkout_cb progress_cb;
1888     void *progress_arg;
1889     got_worktree_cancel_cb cancel_cb;
1890     void *cancel_arg;
1891     struct got_object_id *commit_id2;
1892 };
1893 
1894 static const struct got_error *
1895 merge_file_cb(void *arg, struct got_blob_object *blob1,
1896     struct got_blob_object *blob2, struct got_object_id *id1,
1897     struct got_object_id *id2, const char *path1, const char *path2,
1898     struct got_repository *repo)
1899 {
1900 	static const struct got_error *err = NULL;
1901 	struct merge_file_cb_arg *a = arg;
1902 	struct got_fileindex_entry *ie;
1903 	char *ondisk_path = NULL;
1904 	struct stat sb;
1905 	unsigned char status;
1906 	int local_changes_subsumed;
1907 
1908 	if (blob1 && blob2) {
1909 		ie = got_fileindex_entry_get(a->fileindex, path2);
1910 		if (ie == NULL)
1911 			return (*a->progress_cb)(a->progress_arg,
1912 			    GOT_STATUS_MISSING, path2);
1913 
1914 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1915 		    path2) == -1)
1916 			return got_error_from_errno("asprintf");
1917 
1918 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1919 		if (err)
1920 			goto done;
1921 
1922 		if (status == GOT_STATUS_DELETE) {
1923 			err = (*a->progress_cb)(a->progress_arg,
1924 			    GOT_STATUS_MERGE, path2);
1925 			goto done;
1926 		}
1927 		if (status != GOT_STATUS_NO_CHANGE &&
1928 		    status != GOT_STATUS_MODIFY &&
1929 		    status != GOT_STATUS_CONFLICT &&
1930 		    status != GOT_STATUS_ADD) {
1931 			err = (*a->progress_cb)(a->progress_arg, status, path2);
1932 			goto done;
1933 		}
1934 
1935 		err = merge_blob(&local_changes_subsumed, a->worktree, blob1,
1936 		    ondisk_path, path2, sb.st_mode, blob2, a->commit_id2, repo,
1937 		    a->progress_cb, a->progress_arg);
1938 	} else if (blob1) {
1939 		ie = got_fileindex_entry_get(a->fileindex, path1);
1940 		if (ie == NULL)
1941 			return (*a->progress_cb)(a->progress_arg,
1942 			    GOT_STATUS_MISSING, path2);
1943 
1944 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1945 		    path1) == -1)
1946 			return got_error_from_errno("asprintf");
1947 
1948 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1949 		if (err)
1950 			goto done;
1951 
1952 		switch (status) {
1953 		case GOT_STATUS_NO_CHANGE:
1954 			err = (*a->progress_cb)(a->progress_arg,
1955 			    GOT_STATUS_DELETE, path1);
1956 			if (err)
1957 				goto done;
1958 			err = remove_ondisk_file(a->worktree->root_path, path1);
1959 			if (err)
1960 				goto done;
1961 			if (ie)
1962 				got_fileindex_entry_mark_deleted_from_disk(ie);
1963 			break;
1964 		case GOT_STATUS_DELETE:
1965 		case GOT_STATUS_MISSING:
1966 			err = (*a->progress_cb)(a->progress_arg,
1967 			    GOT_STATUS_DELETE, path1);
1968 			if (err)
1969 				goto done;
1970 			if (ie)
1971 				got_fileindex_entry_mark_deleted_from_disk(ie);
1972 			break;
1973 		case GOT_STATUS_ADD:
1974 		case GOT_STATUS_MODIFY:
1975 		case GOT_STATUS_CONFLICT:
1976 			err = (*a->progress_cb)(a->progress_arg,
1977 			    GOT_STATUS_CANNOT_DELETE, path1);
1978 			if (err)
1979 				goto done;
1980 			break;
1981 		case GOT_STATUS_OBSTRUCTED:
1982 			err = (*a->progress_cb)(a->progress_arg, status, path1);
1983 			if (err)
1984 				goto done;
1985 			break;
1986 		default:
1987 			break;
1988 		}
1989 	} else if (blob2) {
1990 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1991 		    path2) == -1)
1992 			return got_error_from_errno("asprintf");
1993 		ie = got_fileindex_entry_get(a->fileindex, path2);
1994 		if (ie) {
1995 			err = get_file_status(&status, &sb, ie, ondisk_path,
1996 			    repo);
1997 			if (err)
1998 				goto done;
1999 			if (status != GOT_STATUS_NO_CHANGE &&
2000 			    status != GOT_STATUS_MODIFY &&
2001 			    status != GOT_STATUS_CONFLICT &&
2002 			    status != GOT_STATUS_ADD) {
2003 				err = (*a->progress_cb)(a->progress_arg,
2004 				    status, path2);
2005 				goto done;
2006 			}
2007 			err = merge_blob(&local_changes_subsumed, a->worktree,
2008 			    NULL, ondisk_path, path2, sb.st_mode, blob2,
2009 			    a->commit_id2, repo,
2010 			    a->progress_cb, a->progress_arg);
2011 			if (status == GOT_STATUS_DELETE) {
2012 				err = update_blob_fileindex_entry(a->worktree,
2013 				    a->fileindex, ie, ondisk_path, ie->path,
2014 				    blob2, 0);
2015 				if (err)
2016 					goto done;
2017 			}
2018 		} else {
2019 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
2020 			err = install_blob(a->worktree, ondisk_path, path2,
2021 			    /* XXX get this from parent tree! */
2022 			    GOT_DEFAULT_FILE_MODE,
2023 			    sb.st_mode, blob2, 0, 0, repo,
2024 			    a->progress_cb, a->progress_arg);
2025 			if (err)
2026 				goto done;
2027 			err = got_fileindex_entry_alloc(&ie,
2028 			    ondisk_path, path2, NULL, NULL);
2029 			if (err)
2030 				goto done;
2031 			err = got_fileindex_entry_add(a->fileindex, ie);
2032 			if (err) {
2033 				got_fileindex_entry_free(ie);
2034 				goto done;
2035 			}
2036 		}
2037 	}
2038 done:
2039 	free(ondisk_path);
2040 	return err;
2041 }
2042 
2043 struct check_merge_ok_arg {
2044 	struct got_worktree *worktree;
2045 	struct got_repository *repo;
2046 };
2047 
2048 static const struct got_error *
2049 check_merge_ok(void *arg, struct got_fileindex_entry *ie)
2050 {
2051 	const struct got_error *err = NULL;
2052 	struct check_merge_ok_arg *a = arg;
2053 	unsigned char status;
2054 	struct stat sb;
2055 	char *ondisk_path;
2056 
2057 	/* Reject merges into a work tree with mixed base commits. */
2058 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
2059 	    SHA1_DIGEST_LENGTH))
2060 		return got_error(GOT_ERR_MIXED_COMMITS);
2061 
2062 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
2063 	    == -1)
2064 		return got_error_from_errno("asprintf");
2065 
2066 	/* Reject merges into a work tree with conflicted files. */
2067 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
2068 	if (err)
2069 		return err;
2070 	if (status == GOT_STATUS_CONFLICT)
2071 		return got_error(GOT_ERR_CONFLICTS);
2072 
2073 	return NULL;
2074 }
2075 
2076 static const struct got_error *
2077 merge_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
2078     const char *fileindex_path, struct got_object_id *commit_id1,
2079     struct got_object_id *commit_id2, struct got_repository *repo,
2080     got_worktree_checkout_cb progress_cb, void *progress_arg,
2081     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2082 {
2083 	const struct got_error *err = NULL, *sync_err;
2084 	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
2085 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
2086 	struct merge_file_cb_arg arg;
2087 
2088 	if (commit_id1) {
2089 		err = got_object_id_by_path(&tree_id1, repo, commit_id1,
2090 		    worktree->path_prefix);
2091 		if (err)
2092 			goto done;
2093 
2094 		err = got_object_open_as_tree(&tree1, repo, tree_id1);
2095 		if (err)
2096 			goto done;
2097 	}
2098 
2099 	err = got_object_id_by_path(&tree_id2, repo, commit_id2,
2100 	    worktree->path_prefix);
2101 	if (err)
2102 		goto done;
2103 
2104 	err = got_object_open_as_tree(&tree2, repo, tree_id2);
2105 	if (err)
2106 		goto done;
2107 
2108 	arg.worktree = worktree;
2109 	arg.fileindex = fileindex;
2110 	arg.progress_cb = progress_cb;
2111 	arg.progress_arg = progress_arg;
2112 	arg.cancel_cb = cancel_cb;
2113 	arg.cancel_arg = cancel_arg;
2114 	arg.commit_id2 = commit_id2;
2115 	err = got_diff_tree(tree1, tree2, "", "", repo, merge_file_cb, &arg, 1);
2116 	sync_err = sync_fileindex(fileindex, fileindex_path);
2117 	if (sync_err && err == NULL)
2118 		err = sync_err;
2119 done:
2120 	if (tree1)
2121 		got_object_tree_close(tree1);
2122 	if (tree2)
2123 		got_object_tree_close(tree2);
2124 	return err;
2125 }
2126 
2127 const struct got_error *
2128 got_worktree_merge_files(struct got_worktree *worktree,
2129     struct got_object_id *commit_id1, struct got_object_id *commit_id2,
2130     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
2131     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2132 {
2133 	const struct got_error *err, *unlockerr;
2134 	char *fileindex_path = NULL;
2135 	struct got_fileindex *fileindex = NULL;
2136 	struct check_merge_ok_arg mok_arg;
2137 
2138 	err = lock_worktree(worktree, LOCK_EX);
2139 	if (err)
2140 		return err;
2141 
2142 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2143 	if (err)
2144 		goto done;
2145 
2146 	mok_arg.worktree = worktree;
2147 	mok_arg.repo = repo;
2148 	err = got_fileindex_for_each_entry_safe(fileindex, check_merge_ok,
2149 	    &mok_arg);
2150 	if (err)
2151 		goto done;
2152 
2153 	err = merge_files(worktree, fileindex, fileindex_path, commit_id1,
2154 	    commit_id2, repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
2155 done:
2156 	if (fileindex)
2157 		got_fileindex_free(fileindex);
2158 	free(fileindex_path);
2159 	unlockerr = lock_worktree(worktree, LOCK_SH);
2160 	if (unlockerr && err == NULL)
2161 		err = unlockerr;
2162 	return err;
2163 }
2164 
2165 struct diff_dir_cb_arg {
2166     struct got_fileindex *fileindex;
2167     struct got_worktree *worktree;
2168     const char *status_path;
2169     size_t status_path_len;
2170     struct got_repository *repo;
2171     got_worktree_status_cb status_cb;
2172     void *status_arg;
2173     got_worktree_cancel_cb cancel_cb;
2174     void *cancel_arg;
2175 };
2176 
2177 static const struct got_error *
2178 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
2179     got_worktree_status_cb status_cb, void *status_arg,
2180     struct got_repository *repo)
2181 {
2182 	const struct got_error *err = NULL;
2183 	unsigned char status = GOT_STATUS_NO_CHANGE;
2184 	struct stat sb;
2185 	struct got_object_id blob_id, commit_id;
2186 
2187 	err = get_file_status(&status, &sb, ie, abspath, repo);
2188 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
2189 		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2190 		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2191 		err = (*status_cb)(status_arg, status, ie->path, &blob_id,
2192 		    &commit_id);
2193 	}
2194 	return err;
2195 }
2196 
2197 static const struct got_error *
2198 status_old_new(void *arg, struct got_fileindex_entry *ie,
2199     struct dirent *de, const char *parent_path)
2200 {
2201 	const struct got_error *err = NULL;
2202 	struct diff_dir_cb_arg *a = arg;
2203 	char *abspath;
2204 
2205 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2206 		return got_error(GOT_ERR_CANCELLED);
2207 
2208 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
2209 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
2210 		return NULL;
2211 
2212 	if (parent_path[0]) {
2213 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
2214 		    parent_path, de->d_name) == -1)
2215 			return got_error_from_errno("asprintf");
2216 	} else {
2217 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
2218 		    de->d_name) == -1)
2219 			return got_error_from_errno("asprintf");
2220 	}
2221 
2222 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
2223 	    a->repo);
2224 	free(abspath);
2225 	return err;
2226 }
2227 
2228 static const struct got_error *
2229 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
2230 {
2231 	struct diff_dir_cb_arg *a = arg;
2232 	struct got_object_id blob_id, commit_id;
2233 	unsigned char status;
2234 
2235 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2236 		return got_error(GOT_ERR_CANCELLED);
2237 
2238 	if (!got_path_is_child(ie->path, a->status_path, a->status_path_len))
2239 		return NULL;
2240 
2241 	memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2242 	memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2243 	if (got_fileindex_entry_has_file_on_disk(ie))
2244 		status = GOT_STATUS_MISSING;
2245 	else
2246 		status = GOT_STATUS_DELETE;
2247 	return (*a->status_cb)(a->status_arg, status, ie->path, &blob_id,
2248 	    &commit_id);
2249 }
2250 
2251 static const struct got_error *
2252 status_new(void *arg, struct dirent *de, const char *parent_path)
2253 {
2254 	const struct got_error *err = NULL;
2255 	struct diff_dir_cb_arg *a = arg;
2256 	char *path = NULL;
2257 
2258 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2259 		return got_error(GOT_ERR_CANCELLED);
2260 
2261 	if (de->d_type == DT_DIR)
2262 		return NULL;
2263 
2264 	/* XXX ignore symlinks for now */
2265 	if (de->d_type == DT_LNK)
2266 		return NULL;
2267 
2268 	if (parent_path[0]) {
2269 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
2270 			return got_error_from_errno("asprintf");
2271 	} else {
2272 		path = de->d_name;
2273 	}
2274 
2275 	if (got_path_is_child(path, a->status_path, a->status_path_len))
2276 		err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED,
2277 		    path, NULL, NULL);
2278 	if (parent_path[0])
2279 		free(path);
2280 	return err;
2281 }
2282 
2283 static const struct got_error *
2284 report_single_file_status(const char *path, const char *ondisk_path,
2285 struct got_fileindex *fileindex, got_worktree_status_cb status_cb,
2286 void *status_arg, struct got_repository *repo)
2287 {
2288 	struct got_fileindex_entry *ie;
2289 	struct stat sb;
2290 
2291 	ie = got_fileindex_entry_get(fileindex, path);
2292 	if (ie)
2293 		return report_file_status(ie, ondisk_path, status_cb,
2294 		    status_arg, repo);
2295 
2296 	if (lstat(ondisk_path, &sb) == -1) {
2297 		if (errno != ENOENT)
2298 			return got_error_from_errno2("lstat", ondisk_path);
2299 		return NULL;
2300 	}
2301 
2302 	if (S_ISREG(sb.st_mode))
2303 		return (*status_cb)(status_arg, GOT_STATUS_UNVERSIONED, path,
2304 		    NULL, NULL);
2305 
2306 	return NULL;
2307 }
2308 
2309 static const struct got_error *
2310 worktree_status(struct got_worktree *worktree, const char *path,
2311     struct got_fileindex *fileindex, struct got_repository *repo,
2312     got_worktree_status_cb status_cb, void *status_arg,
2313     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2314 {
2315 	const struct got_error *err = NULL;
2316 	DIR *workdir = NULL;
2317 	struct got_fileindex_diff_dir_cb fdiff_cb;
2318 	struct diff_dir_cb_arg arg;
2319 	char *ondisk_path = NULL;
2320 
2321 	if (asprintf(&ondisk_path, "%s%s%s",
2322 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
2323 		err = got_error_from_errno("asprintf");
2324 		goto done;
2325 	}
2326 	workdir = opendir(ondisk_path);
2327 	if (workdir == NULL) {
2328 		if (errno != ENOTDIR && errno != ENOENT)
2329 			err = got_error_from_errno2("opendir", ondisk_path);
2330 		else
2331 			err = report_single_file_status(path, ondisk_path,
2332 			    fileindex, status_cb, status_arg, repo);
2333 	} else {
2334 		fdiff_cb.diff_old_new = status_old_new;
2335 		fdiff_cb.diff_old = status_old;
2336 		fdiff_cb.diff_new = status_new;
2337 		arg.fileindex = fileindex;
2338 		arg.worktree = worktree;
2339 		arg.status_path = path;
2340 		arg.status_path_len = strlen(path);
2341 		arg.repo = repo;
2342 		arg.status_cb = status_cb;
2343 		arg.status_arg = status_arg;
2344 		arg.cancel_cb = cancel_cb;
2345 		arg.cancel_arg = cancel_arg;
2346 		err = got_fileindex_diff_dir(fileindex, workdir,
2347 		    worktree->root_path, path, repo, &fdiff_cb, &arg);
2348 	}
2349 done:
2350 	if (workdir)
2351 		closedir(workdir);
2352 	free(ondisk_path);
2353 	return err;
2354 }
2355 
2356 const struct got_error *
2357 got_worktree_status(struct got_worktree *worktree,
2358     struct got_pathlist_head *paths, struct got_repository *repo,
2359     got_worktree_status_cb status_cb, void *status_arg,
2360     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2361 {
2362 	const struct got_error *err = NULL;
2363 	char *fileindex_path = NULL;
2364 	struct got_fileindex *fileindex = NULL;
2365 	struct got_pathlist_entry *pe;
2366 
2367 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2368 	if (err)
2369 		return err;
2370 
2371 	TAILQ_FOREACH(pe, paths, entry) {
2372 		err = worktree_status(worktree, pe->path, fileindex, repo,
2373 			status_cb, status_arg, cancel_cb, cancel_arg);
2374 		if (err)
2375 			break;
2376 	}
2377 	free(fileindex_path);
2378 	got_fileindex_free(fileindex);
2379 	return err;
2380 }
2381 
2382 const struct got_error *
2383 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
2384     const char *arg)
2385 {
2386 	const struct got_error *err = NULL;
2387 	char *resolved, *cwd = NULL, *path = NULL;
2388 	size_t len;
2389 
2390 	*wt_path = NULL;
2391 
2392 	resolved = realpath(arg, NULL);
2393 	if (resolved == NULL) {
2394 		if (errno != ENOENT)
2395 			return got_error_from_errno2("realpath", arg);
2396 		cwd = getcwd(NULL, 0);
2397 		if (cwd == NULL)
2398 			return got_error_from_errno("getcwd");
2399 		if (asprintf(&resolved, "%s/%s", cwd, arg) == -1) {
2400 			err = got_error_from_errno("asprintf");
2401 			goto done;
2402 		}
2403 	}
2404 
2405 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
2406 	    strlen(got_worktree_get_root_path(worktree)))) {
2407 		err = got_error(GOT_ERR_BAD_PATH);
2408 		goto done;
2409 	}
2410 
2411 	if (strlen(resolved) > strlen(got_worktree_get_root_path(worktree))) {
2412 		err = got_path_skip_common_ancestor(&path,
2413 		    got_worktree_get_root_path(worktree), resolved);
2414 		if (err)
2415 			goto done;
2416 	} else {
2417 		path = strdup("");
2418 		if (path == NULL) {
2419 			err = got_error_from_errno("strdup");
2420 			goto done;
2421 		}
2422 	}
2423 
2424 	/* XXX status walk can't deal with trailing slash! */
2425 	len = strlen(path);
2426 	while (len > 0 && path[len - 1] == '/') {
2427 		path[len - 1] = '\0';
2428 		len--;
2429 	}
2430 done:
2431 	free(resolved);
2432 	free(cwd);
2433 	if (err == NULL)
2434 		*wt_path = path;
2435 	else
2436 		free(path);
2437 	return err;
2438 }
2439 
2440 static const struct got_error *
2441 schedule_addition(const char *ondisk_path, struct got_fileindex *fileindex,
2442     const char *relpath, got_worktree_status_cb status_cb, void *status_arg,
2443     struct got_repository *repo)
2444 {
2445 	const struct got_error *err = NULL;
2446 	struct got_fileindex_entry *ie;
2447 
2448 	/* Re-adding an existing entry is a no-op. */
2449 	if (got_fileindex_entry_get(fileindex, relpath) != NULL)
2450 		return NULL;
2451 
2452 	err = got_fileindex_entry_alloc(&ie, ondisk_path, relpath, NULL, NULL);
2453 	if (err)
2454 		return err;
2455 
2456 	err = got_fileindex_entry_add(fileindex, ie);
2457 	if (err) {
2458 		got_fileindex_entry_free(ie);
2459 		return err;
2460 	}
2461 
2462 	return report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2463 }
2464 
2465 const struct got_error *
2466 got_worktree_schedule_add(struct got_worktree *worktree,
2467     struct got_pathlist_head *ondisk_paths,
2468     got_worktree_status_cb status_cb, void *status_arg,
2469     struct got_repository *repo)
2470 {
2471 	struct got_fileindex *fileindex = NULL;
2472 	char *fileindex_path = NULL;
2473 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2474 	struct got_pathlist_entry *pe;
2475 
2476 	err = lock_worktree(worktree, LOCK_EX);
2477 	if (err)
2478 		return err;
2479 
2480 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2481 	if (err)
2482 		goto done;
2483 
2484 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2485 		char *relpath;
2486 		err = got_path_skip_common_ancestor(&relpath,
2487 		    got_worktree_get_root_path(worktree), pe->path);
2488 		if (err)
2489 			break;
2490 		err = schedule_addition(pe->path, fileindex, relpath,
2491 		    status_cb, status_arg, repo);
2492 		free(relpath);
2493 		if (err)
2494 			break;
2495 	}
2496 	sync_err = sync_fileindex(fileindex, fileindex_path);
2497 	if (sync_err && err == NULL)
2498 		err = sync_err;
2499 done:
2500 	free(fileindex_path);
2501 	if (fileindex)
2502 		got_fileindex_free(fileindex);
2503 	unlockerr = lock_worktree(worktree, LOCK_SH);
2504 	if (unlockerr && err == NULL)
2505 		err = unlockerr;
2506 	return err;
2507 }
2508 
2509 static const struct got_error *
2510 schedule_for_deletion(const char *ondisk_path, struct got_fileindex *fileindex,
2511     const char *relpath, int delete_local_mods,
2512     got_worktree_status_cb status_cb, void *status_arg,
2513     struct got_repository *repo)
2514 {
2515 	const struct got_error *err = NULL;
2516 	struct got_fileindex_entry *ie = NULL;
2517 	unsigned char status;
2518 	struct stat sb;
2519 
2520 	ie = got_fileindex_entry_get(fileindex, relpath);
2521 	if (ie == NULL)
2522 		return got_error(GOT_ERR_BAD_PATH);
2523 
2524 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2525 	if (err)
2526 		return err;
2527 
2528 	if (status != GOT_STATUS_NO_CHANGE) {
2529 		if (status == GOT_STATUS_DELETE)
2530 			return got_error_set_errno(ENOENT, ondisk_path);
2531 		if (status != GOT_STATUS_MODIFY)
2532 			return got_error(GOT_ERR_FILE_STATUS);
2533 		if (!delete_local_mods)
2534 			return got_error(GOT_ERR_FILE_MODIFIED);
2535 	}
2536 
2537 	if (unlink(ondisk_path) != 0)
2538 		return got_error_from_errno2("unlink", ondisk_path);
2539 
2540 	got_fileindex_entry_mark_deleted_from_disk(ie);
2541 	return report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2542 }
2543 
2544 const struct got_error *
2545 got_worktree_schedule_delete(struct got_worktree *worktree,
2546     struct got_pathlist_head *ondisk_paths, int delete_local_mods,
2547     got_worktree_status_cb status_cb, void *status_arg,
2548     struct got_repository *repo)
2549 {
2550 	struct got_fileindex *fileindex = NULL;
2551 	char *fileindex_path = NULL;
2552 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2553 	struct got_pathlist_entry *pe;
2554 
2555 	err = lock_worktree(worktree, LOCK_EX);
2556 	if (err)
2557 		return err;
2558 
2559 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2560 	if (err)
2561 		goto done;
2562 
2563 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2564 		char *relpath;
2565 		err = got_path_skip_common_ancestor(&relpath,
2566 		    got_worktree_get_root_path(worktree), pe->path);
2567 		if (err)
2568 			break;
2569 		err = schedule_for_deletion(pe->path, fileindex, relpath,
2570 		    delete_local_mods, status_cb, status_arg, repo);
2571 		free(relpath);
2572 		if (err)
2573 			break;
2574 	}
2575 	sync_err = sync_fileindex(fileindex, fileindex_path);
2576 	if (sync_err && err == NULL)
2577 		err = sync_err;
2578 done:
2579 	free(fileindex_path);
2580 	if (fileindex)
2581 		got_fileindex_free(fileindex);
2582 	unlockerr = lock_worktree(worktree, LOCK_SH);
2583 	if (unlockerr && err == NULL)
2584 		err = unlockerr;
2585 	return err;
2586 }
2587 
2588 static const struct got_error *
2589 revert_file(struct got_worktree *worktree, struct got_fileindex *fileindex,
2590     const char *ondisk_path,
2591     got_worktree_checkout_cb progress_cb, void *progress_arg,
2592     struct got_repository *repo)
2593 {
2594 	const struct got_error *err = NULL;
2595 	char *relpath = NULL, *parent_path = NULL;
2596 	struct got_fileindex_entry *ie;
2597 	struct got_tree_object *tree = NULL;
2598 	struct got_object_id *tree_id = NULL;
2599 	const struct got_tree_entry *te;
2600 	char *tree_path = NULL, *te_name;
2601 	struct got_blob_object *blob = NULL;
2602 	unsigned char status;
2603 	struct stat sb;
2604 
2605 	err = got_path_skip_common_ancestor(&relpath,
2606 	    got_worktree_get_root_path(worktree), ondisk_path);
2607 	if (err)
2608 		goto done;
2609 
2610 	ie = got_fileindex_entry_get(fileindex, relpath);
2611 	if (ie == NULL) {
2612 		err = got_error(GOT_ERR_BAD_PATH);
2613 		goto done;
2614 	}
2615 
2616 	/* Construct in-repository path of tree which contains this blob. */
2617 	err = got_path_dirname(&parent_path, ie->path);
2618 	if (err) {
2619 		if (err->code != GOT_ERR_BAD_PATH)
2620 			goto done;
2621 		parent_path = strdup("/");
2622 		if (parent_path == NULL) {
2623 			err = got_error_from_errno("strdup");
2624 			goto done;
2625 		}
2626 	}
2627 	if (got_path_is_root_dir(worktree->path_prefix)) {
2628 		tree_path = strdup(parent_path);
2629 		if (tree_path == NULL) {
2630 			err = got_error_from_errno("strdup");
2631 			goto done;
2632 		}
2633 	} else {
2634 		if (got_path_is_root_dir(parent_path)) {
2635 			tree_path = strdup(worktree->path_prefix);
2636 			if (tree_path == NULL) {
2637 				err = got_error_from_errno("strdup");
2638 				goto done;
2639 			}
2640 		} else {
2641 			if (asprintf(&tree_path, "%s/%s",
2642 			    worktree->path_prefix, parent_path) == -1) {
2643 				err = got_error_from_errno("asprintf");
2644 				goto done;
2645 			}
2646 		}
2647 	}
2648 
2649 	err = got_object_id_by_path(&tree_id, repo, worktree->base_commit_id,
2650 	    tree_path);
2651 	if (err)
2652 		goto done;
2653 
2654 	err = got_object_open_as_tree(&tree, repo, tree_id);
2655 	if (err)
2656 		goto done;
2657 
2658 	te_name = basename(ie->path);
2659 	if (te_name == NULL) {
2660 		err = got_error_from_errno2("basename", ie->path);
2661 		goto done;
2662 	}
2663 
2664 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2665 	if (err)
2666 		goto done;
2667 
2668 	te = got_object_tree_find_entry(tree, te_name);
2669 	if (te == NULL && status != GOT_STATUS_ADD) {
2670 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
2671 		goto done;
2672 	}
2673 
2674 	switch (status) {
2675 	case GOT_STATUS_ADD:
2676 		err = (*progress_cb)(progress_arg, GOT_STATUS_REVERT, ie->path);
2677 		if (err)
2678 			goto done;
2679 		got_fileindex_entry_remove(fileindex, ie);
2680 		break;
2681 	case GOT_STATUS_DELETE:
2682 	case GOT_STATUS_MODIFY:
2683 	case GOT_STATUS_CONFLICT:
2684 	case GOT_STATUS_MISSING: {
2685 		struct got_object_id id;
2686 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2687 		err = got_object_open_as_blob(&blob, repo, &id, 8192);
2688 		if (err)
2689 			goto done;
2690 		err = install_blob(worktree, ondisk_path, ie->path,
2691 		    te->mode, sb.st_mode, blob, 0, 1, repo, progress_cb,
2692 		    progress_arg);
2693 		if (err)
2694 			goto done;
2695 		if (status == GOT_STATUS_DELETE) {
2696 			err = update_blob_fileindex_entry(worktree,
2697 			    fileindex, ie, ondisk_path, ie->path, blob, 1);
2698 			if (err)
2699 				goto done;
2700 		}
2701 		break;
2702 	}
2703 	default:
2704 			goto done;
2705 	}
2706 done:
2707 	free(relpath);
2708 	free(parent_path);
2709 	free(tree_path);
2710 	if (blob)
2711 		got_object_blob_close(blob);
2712 	if (tree)
2713 		got_object_tree_close(tree);
2714 	free(tree_id);
2715 	return err;
2716 }
2717 
2718 const struct got_error *
2719 got_worktree_revert(struct got_worktree *worktree,
2720     struct got_pathlist_head *ondisk_paths,
2721     got_worktree_checkout_cb progress_cb, void *progress_arg,
2722     struct got_repository *repo)
2723 {
2724 	struct got_fileindex *fileindex = NULL;
2725 	char *fileindex_path = NULL;
2726 	const struct got_error *err = NULL, *unlockerr = NULL;
2727 	const struct got_error *sync_err = NULL;
2728 	struct got_pathlist_entry *pe;
2729 
2730 	err = lock_worktree(worktree, LOCK_EX);
2731 	if (err)
2732 		return err;
2733 
2734 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2735 	if (err)
2736 		goto done;
2737 
2738 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2739 		err = revert_file(worktree, fileindex, pe->path,
2740 		    progress_cb, progress_arg, repo);
2741 		if (err)
2742 			break;
2743 	}
2744 	sync_err = sync_fileindex(fileindex, fileindex_path);
2745 	if (sync_err && err == NULL)
2746 		err = sync_err;
2747 done:
2748 	free(fileindex_path);
2749 	if (fileindex)
2750 		got_fileindex_free(fileindex);
2751 	unlockerr = lock_worktree(worktree, LOCK_SH);
2752 	if (unlockerr && err == NULL)
2753 		err = unlockerr;
2754 	return err;
2755 }
2756 
2757 static void
2758 free_commitable(struct got_commitable *ct)
2759 {
2760 	free(ct->path);
2761 	free(ct->in_repo_path);
2762 	free(ct->ondisk_path);
2763 	free(ct->blob_id);
2764 	free(ct->base_blob_id);
2765 	free(ct->base_commit_id);
2766 	free(ct);
2767 }
2768 
2769 struct collect_commitables_arg {
2770 	struct got_pathlist_head *commitable_paths;
2771 	struct got_repository *repo;
2772 	struct got_worktree *worktree;
2773 };
2774 
2775 static const struct got_error *
2776 collect_commitables(void *arg, unsigned char status, const char *relpath,
2777     struct got_object_id *blob_id, struct got_object_id *commit_id)
2778 {
2779 	struct collect_commitables_arg *a = arg;
2780 	const struct got_error *err = NULL;
2781 	struct got_commitable *ct = NULL;
2782 	struct got_pathlist_entry *new = NULL;
2783 	char *parent_path = NULL, *path = NULL;
2784 	struct stat sb;
2785 
2786 	if (status == GOT_STATUS_CONFLICT)
2787 		return got_error(GOT_ERR_COMMIT_CONFLICT);
2788 
2789 	if (status != GOT_STATUS_MODIFY && status != GOT_STATUS_ADD &&
2790 	    status != GOT_STATUS_DELETE)
2791 		return NULL;
2792 
2793 	if (asprintf(&path, "/%s", relpath) == -1) {
2794 		err = got_error_from_errno("asprintf");
2795 		goto done;
2796 	}
2797 	if (strcmp(path, "/") == 0) {
2798 		parent_path = strdup("");
2799 		if (parent_path == NULL)
2800 			return got_error_from_errno("strdup");
2801 	} else {
2802 		err = got_path_dirname(&parent_path, path);
2803 		if (err)
2804 			return err;
2805 	}
2806 
2807 	ct = calloc(1, sizeof(*ct));
2808 	if (ct == NULL) {
2809 		err = got_error_from_errno("calloc");
2810 		goto done;
2811 	}
2812 
2813 	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
2814 	    relpath) == -1) {
2815 		err = got_error_from_errno("asprintf");
2816 		goto done;
2817 	}
2818 	if (status == GOT_STATUS_DELETE) {
2819 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
2820 	} else {
2821 		if (lstat(ct->ondisk_path, &sb) != 0) {
2822 			err = got_error_from_errno2("lstat", ct->ondisk_path);
2823 			goto done;
2824 		}
2825 		ct->mode = sb.st_mode;
2826 	}
2827 
2828 	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
2829 	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
2830 	    relpath) == -1) {
2831 		err = got_error_from_errno("asprintf");
2832 		goto done;
2833 	}
2834 
2835 	ct->status = status;
2836 	ct->blob_id = NULL; /* will be filled in when blob gets created */
2837 	if (ct->status != GOT_STATUS_ADD) {
2838 		ct->base_blob_id = got_object_id_dup(blob_id);
2839 		if (ct->base_blob_id == NULL) {
2840 			err = got_error_from_errno("got_object_id_dup");
2841 			goto done;
2842 		}
2843 		ct->base_commit_id = got_object_id_dup(commit_id);
2844 		if (ct->base_commit_id == NULL) {
2845 			err = got_error_from_errno("got_object_id_dup");
2846 			goto done;
2847 		}
2848 	}
2849 	ct->path = strdup(path);
2850 	if (ct->path == NULL) {
2851 		err = got_error_from_errno("strdup");
2852 		goto done;
2853 	}
2854 	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
2855 done:
2856 	if (ct && (err || new == NULL))
2857 		free_commitable(ct);
2858 	free(parent_path);
2859 	free(path);
2860 	return err;
2861 }
2862 
2863 static const struct got_error *write_tree(struct got_object_id **,
2864     struct got_tree_object *, const char *, struct got_pathlist_head *,
2865     got_worktree_status_cb status_cb, void *status_arg,
2866     struct got_repository *);
2867 
2868 static const struct got_error *
2869 write_subtree(struct got_object_id **new_subtree_id,
2870     struct got_tree_entry *te, const char *parent_path,
2871     struct got_pathlist_head *commitable_paths,
2872     got_worktree_status_cb status_cb, void *status_arg,
2873     struct got_repository *repo)
2874 {
2875 	const struct got_error *err = NULL;
2876 	struct got_tree_object *subtree;
2877 	char *subpath;
2878 
2879 	if (asprintf(&subpath, "%s%s%s", parent_path,
2880 	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
2881 		return got_error_from_errno("asprintf");
2882 
2883 	err = got_object_open_as_tree(&subtree, repo, te->id);
2884 	if (err)
2885 		return err;
2886 
2887 	err = write_tree(new_subtree_id, subtree, subpath, commitable_paths,
2888 	    status_cb, status_arg, repo);
2889 	got_object_tree_close(subtree);
2890 	free(subpath);
2891 	return err;
2892 }
2893 
2894 static const struct got_error *
2895 match_ct_parent_path(int *match, struct got_commitable *ct, const char *path)
2896 {
2897 	const struct got_error *err = NULL;
2898 	char *ct_parent_path = NULL;
2899 
2900 	*match = 0;
2901 
2902 	if (strchr(ct->in_repo_path, '/') == NULL) {
2903 		*match = got_path_is_root_dir(path);
2904 		return NULL;
2905 	}
2906 
2907 	err = got_path_dirname(&ct_parent_path, ct->in_repo_path);
2908 	if (err)
2909 		return err;
2910 	*match = (strcmp(path, ct_parent_path) == 0);
2911 	free(ct_parent_path);
2912 	return err;
2913 }
2914 
2915 static mode_t
2916 get_ct_file_mode(struct got_commitable *ct)
2917 {
2918 	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
2919 }
2920 
2921 static const struct got_error *
2922 alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
2923     struct got_tree_entry *te, struct got_commitable *ct)
2924 {
2925 	const struct got_error *err = NULL;
2926 
2927 	*new_te = NULL;
2928 
2929 	err = got_object_tree_entry_dup(new_te, te);
2930 	if (err)
2931 		goto done;
2932 
2933 	(*new_te)->mode = get_ct_file_mode(ct);
2934 
2935 	free((*new_te)->id);
2936 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2937 	if ((*new_te)->id == NULL) {
2938 		err = got_error_from_errno("got_object_id_dup");
2939 		goto done;
2940 	}
2941 done:
2942 	if (err && *new_te) {
2943 		got_object_tree_entry_close(*new_te);
2944 		*new_te = NULL;
2945 	}
2946 	return err;
2947 }
2948 
2949 static const struct got_error *
2950 alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
2951     struct got_commitable *ct)
2952 {
2953 	const struct got_error *err = NULL;
2954 	char *ct_name;
2955 
2956 	 *new_te = NULL;
2957 
2958 	*new_te = calloc(1, sizeof(**new_te));
2959 	if (*new_te == NULL)
2960 		return got_error_from_errno("calloc");
2961 
2962 	ct_name = basename(ct->path);
2963 	if (ct_name == NULL) {
2964 		err = got_error_from_errno2("basename", ct->path);
2965 		goto done;
2966 	}
2967 	(*new_te)->name = strdup(ct_name);
2968 	if ((*new_te)->name == NULL) {
2969 		err = got_error_from_errno("strdup");
2970 		goto done;
2971 	}
2972 
2973 	(*new_te)->mode = get_ct_file_mode(ct);
2974 
2975 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2976 	if ((*new_te)->id == NULL) {
2977 		err = got_error_from_errno("got_object_id_dup");
2978 		goto done;
2979 	}
2980 done:
2981 	if (err && *new_te) {
2982 		got_object_tree_entry_close(*new_te);
2983 		*new_te = NULL;
2984 	}
2985 	return err;
2986 }
2987 
2988 static const struct got_error *
2989 insert_tree_entry(struct got_tree_entry *new_te,
2990     struct got_pathlist_head *paths)
2991 {
2992 	const struct got_error *err = NULL;
2993 	struct got_pathlist_entry *new_pe;
2994 
2995 	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
2996 	if (err)
2997 		return err;
2998 	if (new_pe == NULL)
2999 		return got_error(GOT_ERR_TREE_DUP_ENTRY);
3000 	return NULL;
3001 }
3002 
3003 static const struct got_error *
3004 report_ct_status(struct got_commitable *ct,
3005     got_worktree_status_cb status_cb, void *status_arg)
3006 {
3007 	const char *ct_path = ct->path;
3008 	while (ct_path[0] == '/')
3009 		ct_path++;
3010 	return (*status_cb)(status_arg, ct->status, ct_path, ct->blob_id, NULL);
3011 }
3012 
3013 static const struct got_error *
3014 match_modified_subtree(int *modified, struct got_tree_entry *te,
3015     const char *base_tree_path, struct got_pathlist_head *commitable_paths)
3016 {
3017 	const struct got_error *err = NULL;
3018 	struct got_pathlist_entry *pe;
3019 	char *te_path;
3020 
3021 	*modified = 0;
3022 
3023 	if (asprintf(&te_path, "%s%s%s", base_tree_path,
3024 	    got_path_is_root_dir(base_tree_path) ? "" : "/",
3025 	    te->name) == -1)
3026 		return got_error_from_errno("asprintf");
3027 
3028 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3029 		struct got_commitable *ct = pe->data;
3030 		*modified = got_path_is_child(ct->in_repo_path, te_path,
3031 		    strlen(te_path));
3032 		 if (*modified)
3033 			break;
3034 	}
3035 
3036 	free(te_path);
3037 	return err;
3038 }
3039 
3040 static const struct got_error *
3041 match_deleted_or_modified_ct(struct got_commitable **ctp,
3042     struct got_tree_entry *te, const char *base_tree_path,
3043     struct got_pathlist_head *commitable_paths)
3044 {
3045 	const struct got_error *err = NULL;
3046 	struct got_pathlist_entry *pe;
3047 
3048 	*ctp = NULL;
3049 
3050 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3051 		struct got_commitable *ct = pe->data;
3052 		char *ct_name = NULL;
3053 		int path_matches;
3054 
3055 		if (ct->status != GOT_STATUS_MODIFY &&
3056 		    ct->status != GOT_STATUS_DELETE)
3057 			continue;
3058 
3059 		if (got_object_id_cmp(ct->base_blob_id, te->id) != 0)
3060 			continue;
3061 
3062 		 err = match_ct_parent_path(&path_matches, ct, base_tree_path);
3063 		 if (err)
3064 			return err;
3065 		if (!path_matches)
3066 			continue;
3067 
3068 		ct_name = basename(pe->path);
3069 		if (ct_name == NULL)
3070 			return got_error_from_errno2("basename", pe->path);
3071 
3072 		if (strcmp(te->name, ct_name) != 0)
3073 			continue;
3074 
3075 		*ctp = ct;
3076 		break;
3077 	}
3078 
3079 	return err;
3080 }
3081 
3082 static const struct got_error *
3083 make_subtree_for_added_blob(struct got_tree_entry **new_tep,
3084     const char *child_path, const char *path_base_tree,
3085     struct got_pathlist_head *commitable_paths,
3086     got_worktree_status_cb status_cb, void *status_arg,
3087     struct got_repository *repo)
3088 {
3089 	const struct got_error *err = NULL;
3090 	struct got_tree_entry *new_te;
3091 	char *subtree_path;
3092 
3093 	*new_tep = NULL;
3094 
3095 	if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
3096 	    got_path_is_root_dir(path_base_tree) ? "" : "/",
3097 	    child_path) == -1)
3098 		return got_error_from_errno("asprintf");
3099 
3100 	new_te = calloc(1, sizeof(*new_te));
3101 	new_te->mode = S_IFDIR;
3102 	new_te->name = strdup(child_path);
3103 	if (new_te->name == NULL) {
3104 		err = got_error_from_errno("strdup");
3105 		got_object_tree_entry_close(new_te);
3106 		goto done;
3107 	}
3108 	err = write_tree(&new_te->id, NULL, subtree_path,
3109 	    commitable_paths, status_cb, status_arg, repo);
3110 	if (err) {
3111 		got_object_tree_entry_close(new_te);
3112 		goto done;
3113 	}
3114 done:
3115 	free(subtree_path);
3116 	if (err == NULL)
3117 		*new_tep = new_te;
3118 	return err;
3119 }
3120 
3121 static const struct got_error *
3122 write_tree(struct got_object_id **new_tree_id,
3123     struct got_tree_object *base_tree, const char *path_base_tree,
3124     struct got_pathlist_head *commitable_paths,
3125     got_worktree_status_cb status_cb, void *status_arg,
3126     struct got_repository *repo)
3127 {
3128 	const struct got_error *err = NULL;
3129 	const struct got_tree_entries *base_entries = NULL;
3130 	struct got_pathlist_head paths;
3131 	struct got_tree_entries new_tree_entries;
3132 	struct got_tree_entry *te, *new_te = NULL;
3133 	struct got_pathlist_entry *pe;
3134 
3135 	TAILQ_INIT(&paths);
3136 	new_tree_entries.nentries = 0;
3137 	SIMPLEQ_INIT(&new_tree_entries.head);
3138 
3139 	/* Insert, and recurse into, newly added entries first. */
3140 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3141 		struct got_commitable *ct = pe->data;
3142 		char *child_path = NULL, *slash;
3143 
3144 		if (ct->status != GOT_STATUS_ADD ||
3145 		    (ct->flags & GOT_COMMITABLE_ADDED))
3146 			continue;
3147 
3148 		 if (!got_path_is_child(pe->path, path_base_tree,
3149 		     strlen(path_base_tree)))
3150 			continue;
3151 
3152 		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
3153 		    pe->path);
3154 		if (err)
3155 			goto done;
3156 
3157 		slash = strchr(child_path, '/');
3158 		if (slash == NULL) {
3159 			err = alloc_added_blob_tree_entry(&new_te, ct);
3160 			if (err)
3161 				goto done;
3162 			err = report_ct_status(ct, status_cb, status_arg);
3163 			if (err)
3164 				goto done;
3165 			ct->flags |= GOT_COMMITABLE_ADDED;
3166 			err = insert_tree_entry(new_te, &paths);
3167 			if (err)
3168 				goto done;
3169 		} else {
3170 			*slash = '\0'; /* trim trailing path components */
3171 			if (base_tree == NULL ||
3172 			    got_object_tree_find_entry(base_tree, child_path)
3173 			    == NULL) {
3174 				err = make_subtree_for_added_blob(&new_te,
3175 				    child_path, path_base_tree,
3176 				    commitable_paths, status_cb, status_arg,
3177 				    repo);
3178 				if (err)
3179 					goto done;
3180 				err = insert_tree_entry(new_te, &paths);
3181 				if (err)
3182 					goto done;
3183 			}
3184 		}
3185 	}
3186 
3187 	if (base_tree) {
3188 		/* Handle modified and deleted entries. */
3189 		base_entries = got_object_tree_get_entries(base_tree);
3190 		SIMPLEQ_FOREACH(te, &base_entries->head, entry) {
3191 			struct got_commitable *ct = NULL;
3192 
3193 			if (S_ISDIR(te->mode)) {
3194 				int modified;
3195 				err = got_object_tree_entry_dup(&new_te, te);
3196 				if (err)
3197 					goto done;
3198 				err = match_modified_subtree(&modified, te,
3199 				    path_base_tree, commitable_paths);
3200 				if (err)
3201 					goto done;
3202 				/* Avoid recursion into unmodified subtrees. */
3203 				if (modified) {
3204 					free(new_te->id);
3205 					err = write_subtree(&new_te->id, te,
3206 					    path_base_tree, commitable_paths,
3207 					    status_cb, status_arg, repo);
3208 					if (err)
3209 						goto done;
3210 				}
3211 				err = insert_tree_entry(new_te, &paths);
3212 				if (err)
3213 					goto done;
3214 				continue;
3215 			}
3216 
3217 			err = match_deleted_or_modified_ct(&ct, te,
3218 			    path_base_tree, commitable_paths);
3219 			if (ct) {
3220 				/* NB: Deleted entries get dropped here. */
3221 				if (ct->status == GOT_STATUS_MODIFY) {
3222 					err = alloc_modified_blob_tree_entry(
3223 					    &new_te, te, ct);
3224 					if (err)
3225 						goto done;
3226 					err = insert_tree_entry(new_te, &paths);
3227 					if (err)
3228 						goto done;
3229 				}
3230 				err = report_ct_status(ct, status_cb,
3231 				    status_arg);
3232 				if (err)
3233 					goto done;
3234 			} else {
3235 				/* Entry is unchanged; just copy it. */
3236 				err = got_object_tree_entry_dup(&new_te, te);
3237 				if (err)
3238 					goto done;
3239 				err = insert_tree_entry(new_te, &paths);
3240 				if (err)
3241 					goto done;
3242 			}
3243 		}
3244 	}
3245 
3246 	/* Write new list of entries; deleted entries have been dropped. */
3247 	TAILQ_FOREACH(pe, &paths, entry) {
3248 		struct got_tree_entry *te = pe->data;
3249 		new_tree_entries.nentries++;
3250 		SIMPLEQ_INSERT_TAIL(&new_tree_entries.head, te, entry);
3251 	}
3252 	err = got_object_tree_create(new_tree_id, &new_tree_entries, repo);
3253 done:
3254 	got_object_tree_entries_close(&new_tree_entries);
3255 	got_pathlist_free(&paths);
3256 	return err;
3257 }
3258 
3259 static const struct got_error *
3260 update_fileindex_after_commit(struct got_pathlist_head *commitable_paths,
3261     struct got_object_id *new_base_commit_id, struct got_fileindex *fileindex)
3262 {
3263 	const struct got_error *err = NULL;
3264 	struct got_pathlist_entry *pe;
3265 
3266 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3267 		struct got_fileindex_entry *ie;
3268 		struct got_commitable *ct = pe->data;
3269 
3270 		ie = got_fileindex_entry_get(fileindex, pe->path);
3271 		if (ie) {
3272 			if (ct->status == GOT_STATUS_DELETE) {
3273 				got_fileindex_entry_remove(fileindex, ie);
3274 				got_fileindex_entry_free(ie);
3275 			} else
3276 				err = got_fileindex_entry_update(ie,
3277 				    ct->ondisk_path, ct->blob_id->sha1,
3278 				    new_base_commit_id->sha1, 1);
3279 		} else {
3280 			err = got_fileindex_entry_alloc(&ie,
3281 			    ct->ondisk_path, pe->path, ct->blob_id->sha1,
3282 			    new_base_commit_id->sha1);
3283 			if (err)
3284 				break;
3285 			err = got_fileindex_entry_add(fileindex, ie);
3286 			if (err)
3287 				break;
3288 		}
3289 	}
3290 	return err;
3291 }
3292 
3293 static const struct got_error *
3294 check_ct_out_of_date(struct got_commitable *ct, struct got_repository *repo,
3295 	struct got_object_id *head_commit_id)
3296 {
3297 	const struct got_error *err = NULL;
3298 	struct got_object_id *id_in_head = NULL, *id = NULL;
3299 	struct got_commit_object *commit = NULL;
3300 	char *path = NULL;
3301 	const char *ct_path = ct->in_repo_path;
3302 
3303 	while (ct_path[0] == '/')
3304 		ct_path++;
3305 
3306 	/*
3307 	 * Ensure that no modifications were made to files *and their parents*
3308 	 * in commits between the file's base commit and the branch head.
3309 	 *
3310 	 * Checking the parents is important for detecting conflicting tree
3311 	 * configurations (files or parent folders might have been moved,
3312 	 * deleted, added again, etc.). Such changes need to be merged with
3313 	 * local changes before a commit can occur.
3314 	 *
3315 	 * The implication is that the file's (parent) entry in the root
3316 	 * directory must have the same ID in all relevant commits.
3317 	 */
3318 	if (ct->status != GOT_STATUS_ADD) {
3319 		struct got_object_qid *pid;
3320 		char *slash;
3321 		struct got_object_id *root_entry_id = NULL;
3322 
3323 		/* Trivial case: base commit == head commit */
3324 		if (got_object_id_cmp(ct->base_commit_id, head_commit_id) == 0)
3325 			return NULL;
3326 
3327 		/* Compute the path to the root directory's entry. */
3328 		path = strdup(ct_path);
3329 		if (path == NULL) {
3330 			err = got_error_from_errno("strdup");
3331 			goto done;
3332 		}
3333 		slash = strchr(path, '/');
3334 		if (slash)
3335 			*slash = '\0';
3336 
3337 		err = got_object_open_as_commit(&commit, repo, head_commit_id);
3338 		if (err)
3339 			goto done;
3340 
3341 		err = got_object_id_by_path(&root_entry_id, repo,
3342 		    head_commit_id, path);
3343 		if (err)
3344 			goto done;
3345 
3346 		pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(commit));
3347 		while (pid) {
3348 			struct got_commit_object *pcommit;
3349 
3350 			err = got_object_id_by_path(&id, repo, pid->id, path);
3351 			if (err) {
3352 				if (err->code != GOT_ERR_NO_TREE_ENTRY)
3353 					goto done;
3354 				err = NULL;
3355 				break;
3356 			}
3357 
3358 			err = got_object_id_by_path(&id, repo, pid->id, path);
3359 			if (err)
3360 				goto done;
3361 
3362 			if (got_object_id_cmp(id, root_entry_id) != 0) {
3363 				err = got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3364 				break;
3365 			}
3366 
3367 			if (got_object_id_cmp(pid->id, ct->base_commit_id) == 0)
3368 				break; /* all relevant commits scanned */
3369 
3370 			err = got_object_open_as_commit(&pcommit, repo,
3371 			    pid->id);
3372 			if (err)
3373 				goto done;
3374 
3375 			got_object_commit_close(commit);
3376 			commit = pcommit;
3377 			pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(
3378 			    commit));
3379 		}
3380 	} else {
3381 		/* Require that added files don't exist in the branch head. */
3382 		err = got_object_id_by_path(&id_in_head, repo, head_commit_id,
3383 		    ct_path);
3384 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
3385 			goto done;
3386 		err = id_in_head ? got_error(GOT_ERR_COMMIT_OUT_OF_DATE) : NULL;
3387 	}
3388 done:
3389 	if (commit)
3390 		got_object_commit_close(commit);
3391 	free(id_in_head);
3392 	free(id);
3393 	free(path);
3394 	return err;
3395 }
3396 
3397 const struct got_error *
3398 commit_worktree(struct got_object_id **new_commit_id,
3399     struct got_pathlist_head *commitable_paths,
3400     struct got_object_id *head_commit_id, struct got_worktree *worktree,
3401     const char *ondisk_path, const char *author, const char *committer,
3402     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3403     got_worktree_status_cb status_cb, void *status_arg,
3404     struct got_repository *repo)
3405 {
3406 	const struct got_error *err = NULL, *unlockerr = NULL;
3407 	struct got_pathlist_entry *pe;
3408 	const char *head_ref_name = NULL;
3409 	struct got_commit_object *head_commit = NULL;
3410 	struct got_reference *head_ref2 = NULL;
3411 	struct got_object_id *head_commit_id2 = NULL;
3412 	struct got_tree_object *head_tree = NULL;
3413 	struct got_object_id *new_tree_id = NULL;
3414 	struct got_object_id_queue parent_ids;
3415 	struct got_object_qid *pid = NULL;
3416 	char *logmsg = NULL;
3417 
3418 	*new_commit_id = NULL;
3419 
3420 	SIMPLEQ_INIT(&parent_ids);
3421 
3422 	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
3423 	if (err)
3424 		goto done;
3425 
3426 	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
3427 	if (err)
3428 		goto done;
3429 
3430 	if (commit_msg_cb != NULL) {
3431 		err = commit_msg_cb(commitable_paths, &logmsg, commit_arg);
3432 		if (err)
3433 			goto done;
3434 	}
3435 
3436 	if (logmsg == NULL || strlen(logmsg) == 0) {
3437 		err = got_error(GOT_ERR_COMMIT_MSG_EMPTY);
3438 		goto done;
3439 	}
3440 
3441 	/* Create blobs from added and modified files and record their IDs. */
3442 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3443 		struct got_commitable *ct = pe->data;
3444 		char *ondisk_path;
3445 
3446 		if (ct->status != GOT_STATUS_ADD &&
3447 		    ct->status != GOT_STATUS_MODIFY)
3448 			continue;
3449 
3450 		if (asprintf(&ondisk_path, "%s/%s",
3451 		    worktree->root_path, pe->path) == -1) {
3452 			err = got_error_from_errno("asprintf");
3453 			goto done;
3454 		}
3455 		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
3456 		free(ondisk_path);
3457 		if (err)
3458 			goto done;
3459 	}
3460 
3461 	/* Recursively write new tree objects. */
3462 	err = write_tree(&new_tree_id, head_tree, "/", commitable_paths,
3463 	    status_cb, status_arg, repo);
3464 	if (err)
3465 		goto done;
3466 
3467 	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
3468 	if (err)
3469 		goto done;
3470 	SIMPLEQ_INSERT_TAIL(&parent_ids, pid, entry);
3471 	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
3472 	    1, author, time(NULL), committer, time(NULL), logmsg, repo);
3473 	got_object_qid_free(pid);
3474 	if (logmsg != NULL)
3475 		free(logmsg);
3476 	if (err)
3477 		goto done;
3478 
3479 	/* Check if a concurrent commit to our branch has occurred. */
3480 	head_ref_name = got_worktree_get_head_ref_name(worktree);
3481 	if (head_ref_name == NULL) {
3482 		err = got_error_from_errno("got_worktree_get_head_ref_name");
3483 		goto done;
3484 	}
3485 	/* Lock the reference here to prevent concurrent modification. */
3486 	err = got_ref_open(&head_ref2, repo, head_ref_name, 1);
3487 	if (err)
3488 		goto done;
3489 	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
3490 	if (err)
3491 		goto done;
3492 	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
3493 		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
3494 		goto done;
3495 	}
3496 	/* Update branch head in repository. */
3497 	err = got_ref_change_ref(head_ref2, *new_commit_id);
3498 	if (err)
3499 		goto done;
3500 	err = got_ref_write(head_ref2, repo);
3501 	if (err)
3502 		goto done;
3503 
3504 	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
3505 	if (err)
3506 		goto done;
3507 
3508 	err = ref_base_commit(worktree, repo);
3509 	if (err)
3510 		goto done;
3511 done:
3512 	if (head_tree)
3513 		got_object_tree_close(head_tree);
3514 	if (head_commit)
3515 		got_object_commit_close(head_commit);
3516 	free(head_commit_id2);
3517 	if (head_ref2) {
3518 		unlockerr = got_ref_unlock(head_ref2);
3519 		if (unlockerr && err == NULL)
3520 			err = unlockerr;
3521 		got_ref_close(head_ref2);
3522 	}
3523 	return err;
3524 }
3525 
3526 const struct got_error *
3527 got_worktree_commit(struct got_object_id **new_commit_id,
3528     struct got_worktree *worktree, const char *ondisk_path,
3529     const char *author, const char *committer,
3530     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3531     got_worktree_status_cb status_cb, void *status_arg,
3532     struct got_repository *repo)
3533 {
3534 	const struct got_error *err = NULL, *unlockerr = NULL, *sync_err;
3535 	struct got_fileindex *fileindex = NULL;
3536 	char *fileindex_path = NULL, *relpath = NULL;
3537 	struct got_pathlist_head commitable_paths;
3538 	struct collect_commitables_arg cc_arg;
3539 	struct got_pathlist_entry *pe;
3540 	struct got_reference *head_ref = NULL;
3541 	struct got_object_id *head_commit_id = NULL;
3542 
3543 	*new_commit_id = NULL;
3544 
3545 	TAILQ_INIT(&commitable_paths);
3546 
3547 	err = lock_worktree(worktree, LOCK_EX);
3548 	if (err)
3549 		goto done;
3550 
3551 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3552 	if (err)
3553 		goto done;
3554 
3555 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3556 	if (err)
3557 		goto done;
3558 
3559 	if (ondisk_path) {
3560 		if (strcmp(ondisk_path, worktree->root_path) == 0) {
3561 			relpath = strdup("");
3562 			if (relpath == NULL) {
3563 				err = got_error_from_errno("strdup");
3564 				goto done;
3565 			}
3566 		} else {
3567 			err = got_path_skip_common_ancestor(&relpath,
3568 			    worktree->root_path, ondisk_path);
3569 			if (err)
3570 				return err;
3571 		}
3572 	}
3573 
3574 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3575 	if (err)
3576 		goto done;
3577 
3578 	cc_arg.commitable_paths = &commitable_paths;
3579 	cc_arg.worktree = worktree;
3580 	cc_arg.repo = repo;
3581 	err = worktree_status(worktree, relpath ? relpath : "",
3582 	    fileindex, repo, collect_commitables, &cc_arg, NULL, NULL);
3583 	if (err)
3584 		goto done;
3585 
3586 	if (TAILQ_EMPTY(&commitable_paths)) {
3587 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3588 		goto done;
3589 	}
3590 
3591 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3592 		struct got_commitable *ct = pe->data;
3593 		err = check_ct_out_of_date(ct, repo, head_commit_id);
3594 		if (err)
3595 			goto done;
3596 	}
3597 
3598 	err = commit_worktree(new_commit_id, &commitable_paths,
3599 	    head_commit_id, worktree, ondisk_path, author, committer,
3600 	    commit_msg_cb, commit_arg, status_cb, status_arg, repo);
3601 	if (err)
3602 		goto done;
3603 
3604 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
3605 	    fileindex);
3606 	sync_err = sync_fileindex(fileindex, fileindex_path);
3607 	if (sync_err && err == NULL)
3608 		err = sync_err;
3609 done:
3610 	if (fileindex)
3611 		got_fileindex_free(fileindex);
3612 	free(fileindex_path);
3613 	free(relpath);
3614 	unlockerr = lock_worktree(worktree, LOCK_SH);
3615 	if (unlockerr && err == NULL)
3616 		err = unlockerr;
3617 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3618 		struct got_commitable *ct = pe->data;
3619 		free_commitable(ct);
3620 	}
3621 	got_pathlist_free(&commitable_paths);
3622 	return err;
3623 }
3624 
3625 const char *
3626 got_commitable_get_path(struct got_commitable *ct)
3627 {
3628 	return ct->path;
3629 }
3630 
3631 unsigned int
3632 got_commitable_get_status(struct got_commitable *ct)
3633 {
3634 	return ct->status;
3635 }
3636 
3637 struct check_rebase_ok_arg {
3638 	struct got_worktree *worktree;
3639 	struct got_repository *repo;
3640 };
3641 
3642 static const struct got_error *
3643 check_rebase_ok(void *arg, struct got_fileindex_entry *ie)
3644 {
3645 	const struct got_error *err = NULL;
3646 	struct check_rebase_ok_arg *a = arg;
3647 	unsigned char status;
3648 	struct stat sb;
3649 	char *ondisk_path;
3650 
3651 	/* Reject rebase of a work tree with mixed base commits. */
3652 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
3653 	    SHA1_DIGEST_LENGTH))
3654 		return got_error(GOT_ERR_MIXED_COMMITS);
3655 
3656 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
3657 	    == -1)
3658 		return got_error_from_errno("asprintf");
3659 
3660 	/* Reject rebase of a work tree with modified or conflicted files. */
3661 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
3662 	free(ondisk_path);
3663 	if (err)
3664 		return err;
3665 
3666 	if (status != GOT_STATUS_NO_CHANGE)
3667 		return got_error(GOT_ERR_MODIFIED);
3668 
3669 	return NULL;
3670 }
3671 
3672 const struct got_error *
3673 got_worktree_rebase_prepare(struct got_reference **new_base_branch_ref,
3674     struct got_reference **tmp_branch, struct got_fileindex **fileindex,
3675     struct got_worktree *worktree, struct got_reference *branch,
3676     struct got_repository *repo)
3677 {
3678 	const struct got_error *err = NULL;
3679 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
3680 	char *branch_ref_name = NULL;
3681 	char *fileindex_path = NULL;
3682 	struct check_rebase_ok_arg ok_arg;
3683 	struct got_reference *wt_branch = NULL, *branch_ref = NULL;
3684 
3685 	*new_base_branch_ref = NULL;
3686 	*tmp_branch = NULL;
3687 	*fileindex = NULL;
3688 
3689 	err = lock_worktree(worktree, LOCK_EX);
3690 	if (err)
3691 		return err;
3692 
3693 	err = open_fileindex(fileindex, &fileindex_path, worktree);
3694 	if (err)
3695 		goto done;
3696 
3697 	ok_arg.worktree = worktree;
3698 	ok_arg.repo = repo;
3699 	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
3700 	    &ok_arg);
3701 	if (err)
3702 		goto done;
3703 
3704 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3705 	if (err)
3706 		goto done;
3707 
3708 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3709 	if (err)
3710 		goto done;
3711 
3712 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3713 	if (err)
3714 		goto done;
3715 
3716 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
3717 	    0);
3718 	if (err)
3719 		goto done;
3720 
3721 	err = got_ref_alloc_symref(new_base_branch_ref,
3722 	    new_base_branch_ref_name, wt_branch);
3723 	if (err)
3724 		goto done;
3725 	err = got_ref_write(*new_base_branch_ref, repo);
3726 	if (err)
3727 		goto done;
3728 
3729 	/* TODO Lock original branch's ref while rebasing? */
3730 
3731 	err = got_ref_alloc_symref(&branch_ref, branch_ref_name, branch);
3732 	if (err)
3733 		goto done;
3734 
3735 	err = got_ref_write(branch_ref, repo);
3736 	if (err)
3737 		goto done;
3738 
3739 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
3740 	    worktree->base_commit_id);
3741 	if (err)
3742 		goto done;
3743 	err = got_ref_write(*tmp_branch, repo);
3744 	if (err)
3745 		goto done;
3746 
3747 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
3748 	if (err)
3749 		goto done;
3750 done:
3751 	free(fileindex_path);
3752 	free(tmp_branch_name);
3753 	free(new_base_branch_ref_name);
3754 	free(branch_ref_name);
3755 	if (branch_ref)
3756 		got_ref_close(branch_ref);
3757 	if (wt_branch)
3758 		got_ref_close(wt_branch);
3759 	if (err) {
3760 		if (*new_base_branch_ref) {
3761 			got_ref_close(*new_base_branch_ref);
3762 			*new_base_branch_ref = NULL;
3763 		}
3764 		if (*tmp_branch) {
3765 			got_ref_close(*tmp_branch);
3766 			*tmp_branch = NULL;
3767 		}
3768 		if (*fileindex) {
3769 			got_fileindex_free(*fileindex);
3770 			*fileindex = NULL;
3771 		}
3772 		lock_worktree(worktree, LOCK_SH);
3773 	}
3774 	return err;
3775 }
3776 
3777 const struct got_error *
3778 got_worktree_rebase_continue(struct got_object_id **commit_id,
3779     struct got_reference **new_base_branch, struct got_reference **tmp_branch,
3780     struct got_reference **branch, struct got_fileindex **fileindex,
3781     struct got_worktree *worktree, struct got_repository *repo)
3782 {
3783 	const struct got_error *err;
3784 	char *commit_ref_name = NULL, *new_base_branch_ref_name = NULL;
3785 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
3786 	struct got_reference *commit_ref = NULL, *branch_ref = NULL;
3787 	char *fileindex_path = NULL;
3788 
3789 	*commit_id = NULL;
3790 	*new_base_branch = NULL;
3791 	*tmp_branch = NULL;
3792 	*branch = NULL;
3793 	*fileindex = NULL;
3794 
3795 	err = lock_worktree(worktree, LOCK_EX);
3796 	if (err)
3797 		return err;
3798 
3799 	err = open_fileindex(fileindex, &fileindex_path, worktree);
3800 	if (err)
3801 		goto done;
3802 
3803 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3804 	if (err)
3805 		return err;
3806 
3807 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3808 	if (err)
3809 		goto done;
3810 
3811 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3812 	if (err)
3813 		goto done;
3814 
3815 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3816 	if (err)
3817 		goto done;
3818 
3819 	err = got_ref_open(&branch_ref, repo, branch_ref_name, 0);
3820 	if (err)
3821 		goto done;
3822 
3823 	err = got_ref_open(branch, repo,
3824 	    got_ref_get_symref_target(branch_ref), 0);
3825 	if (err)
3826 		goto done;
3827 
3828 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3829 	if (err)
3830 		goto done;
3831 
3832 	err = got_ref_resolve(commit_id, repo, commit_ref);
3833 	if (err)
3834 		goto done;
3835 
3836 	err = got_ref_open(new_base_branch, repo,
3837 	    new_base_branch_ref_name, 0);
3838 	if (err)
3839 		goto done;
3840 
3841 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
3842 	if (err)
3843 		goto done;
3844 done:
3845 	free(commit_ref_name);
3846 	free(branch_ref_name);
3847 	free(fileindex_path);
3848 	if (commit_ref)
3849 		got_ref_close(commit_ref);
3850 	if (branch_ref)
3851 		got_ref_close(branch_ref);
3852 	if (err) {
3853 		free(*commit_id);
3854 		*commit_id = NULL;
3855 		if (*tmp_branch) {
3856 			got_ref_close(*tmp_branch);
3857 			*tmp_branch = NULL;
3858 		}
3859 		if (*new_base_branch) {
3860 			got_ref_close(*new_base_branch);
3861 			*new_base_branch = NULL;
3862 		}
3863 		if (*branch) {
3864 			got_ref_close(*branch);
3865 			*branch = NULL;
3866 		}
3867 		if (*fileindex) {
3868 			got_fileindex_free(*fileindex);
3869 			*fileindex = NULL;
3870 		}
3871 		lock_worktree(worktree, LOCK_SH);
3872 	}
3873 	return err;
3874 }
3875 
3876 const struct got_error *
3877 got_worktree_rebase_in_progress(int *in_progress, struct got_worktree *worktree)
3878 {
3879 	const struct got_error *err;
3880 	char *tmp_branch_name = NULL;
3881 
3882 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3883 	if (err)
3884 		return err;
3885 
3886 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
3887 	free(tmp_branch_name);
3888 	return NULL;
3889 }
3890 
3891 static const struct got_error *
3892 collect_rebase_commit_msg(struct got_pathlist_head *commitable_paths,
3893     char **logmsg, void *arg)
3894 {
3895 	*logmsg = arg;
3896 	return NULL;
3897 }
3898 
3899 static const struct got_error *
3900 rebase_status(void *arg, unsigned char status, const char *path,
3901     struct got_object_id *blob_id, struct got_object_id *commit_id)
3902 {
3903 	return NULL;
3904 }
3905 
3906 struct collect_merged_paths_arg {
3907 	got_worktree_checkout_cb progress_cb;
3908 	void *progress_arg;
3909 	struct got_pathlist_head *merged_paths;
3910 };
3911 
3912 static const struct got_error *
3913 collect_merged_paths(void *arg, unsigned char status, const char *path)
3914 {
3915 	const struct got_error *err;
3916 	struct collect_merged_paths_arg *a = arg;
3917 	char *p;
3918 	struct got_pathlist_entry *new;
3919 
3920 	err = (*a->progress_cb)(a->progress_arg, status, path);
3921 	if (err)
3922 		return err;
3923 
3924 	if (status != GOT_STATUS_MERGE &&
3925 	    status != GOT_STATUS_ADD &&
3926 	    status != GOT_STATUS_DELETE &&
3927 	    status != GOT_STATUS_CONFLICT)
3928 		return NULL;
3929 
3930 	p = strdup(path);
3931 	if (p == NULL)
3932 		return got_error_from_errno("strdup");
3933 
3934 	err = got_pathlist_insert(&new, a->merged_paths, p, NULL);
3935 	if (err || new == NULL)
3936 		free(p);
3937 	return err;
3938 }
3939 
3940 void
3941 got_worktree_rebase_pathlist_free(struct got_pathlist_head *merged_paths)
3942 {
3943 	struct got_pathlist_entry *pe;
3944 
3945 	TAILQ_FOREACH(pe, merged_paths, entry)
3946 		free((char *)pe->path);
3947 
3948 	got_pathlist_free(merged_paths);
3949 }
3950 
3951 static const struct got_error *
3952 store_commit_id(const char *commit_ref_name, struct got_object_id *commit_id,
3953     struct got_repository *repo)
3954 {
3955 	const struct got_error *err;
3956 	struct got_reference *commit_ref = NULL;
3957 
3958 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3959 	if (err) {
3960 		if (err->code != GOT_ERR_NOT_REF)
3961 			goto done;
3962 		err = got_ref_alloc(&commit_ref, commit_ref_name, commit_id);
3963 		if (err)
3964 			goto done;
3965 		err = got_ref_write(commit_ref, repo);
3966 		if (err)
3967 			goto done;
3968 	} else {
3969 		struct got_object_id *stored_id;
3970 		int cmp;
3971 
3972 		err = got_ref_resolve(&stored_id, repo, commit_ref);
3973 		if (err)
3974 			goto done;
3975 		cmp = got_object_id_cmp(commit_id, stored_id);
3976 		free(stored_id);
3977 		if (cmp != 0) {
3978 			err = got_error(GOT_ERR_REBASE_COMMITID);
3979 			goto done;
3980 		}
3981 	}
3982 done:
3983 	if (commit_ref)
3984 		got_ref_close(commit_ref);
3985 	return err;
3986 }
3987 
3988 static const struct got_error *
3989 rebase_merge_files(struct got_pathlist_head *merged_paths,
3990     const char *commit_ref_name, struct got_worktree *worktree,
3991     struct got_fileindex *fileindex, struct got_object_id *parent_commit_id,
3992     struct got_object_id *commit_id, struct got_repository *repo,
3993     got_worktree_checkout_cb progress_cb, void *progress_arg,
3994     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
3995 {
3996 	const struct got_error *err;
3997 	struct got_reference *commit_ref = NULL;
3998 	struct collect_merged_paths_arg cmp_arg;
3999 	char *fileindex_path;
4000 
4001 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
4002 
4003 	err = get_fileindex_path(&fileindex_path, worktree);
4004 	if (err)
4005 		return err;
4006 
4007 	cmp_arg.progress_cb = progress_cb;
4008 	cmp_arg.progress_arg = progress_arg;
4009 	cmp_arg.merged_paths = merged_paths;
4010 	err = merge_files(worktree, fileindex, fileindex_path,
4011 	    parent_commit_id, commit_id, repo, collect_merged_paths,
4012 	    &cmp_arg, cancel_cb, cancel_arg);
4013 	if (commit_ref)
4014 		got_ref_close(commit_ref);
4015 	return err;
4016 }
4017 
4018 const struct got_error *
4019 got_worktree_rebase_merge_files(struct got_pathlist_head *merged_paths,
4020     struct got_worktree *worktree, struct got_fileindex *fileindex,
4021     struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
4022     struct got_repository *repo,
4023     got_worktree_checkout_cb progress_cb, void *progress_arg,
4024     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
4025 {
4026 	const struct got_error *err;
4027 	char *commit_ref_name;
4028 
4029 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4030 	if (err)
4031 		return err;
4032 
4033 	err = store_commit_id(commit_ref_name, commit_id, repo);
4034 	if (err)
4035 		goto done;
4036 
4037 	err = rebase_merge_files(merged_paths, commit_ref_name, worktree,
4038 	    fileindex, parent_commit_id, commit_id, repo, progress_cb,
4039 	    progress_arg, cancel_cb, cancel_arg);
4040 done:
4041 	free(commit_ref_name);
4042 	return err;
4043 }
4044 
4045 const struct got_error *
4046 got_worktree_histedit_merge_files(struct got_pathlist_head *merged_paths,
4047     struct got_worktree *worktree, struct got_fileindex *fileindex,
4048     struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
4049     struct got_repository *repo,
4050     got_worktree_checkout_cb progress_cb, void *progress_arg,
4051     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
4052 {
4053 	const struct got_error *err;
4054 	char *commit_ref_name;
4055 
4056 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4057 	if (err)
4058 		return err;
4059 
4060 	err = store_commit_id(commit_ref_name, commit_id, repo);
4061 	if (err)
4062 		goto done;
4063 
4064 	err = rebase_merge_files(merged_paths, commit_ref_name, worktree,
4065 	    fileindex, parent_commit_id, commit_id, repo, progress_cb,
4066 	    progress_arg, cancel_cb, cancel_arg);
4067 done:
4068 	free(commit_ref_name);
4069 	return err;
4070 }
4071 
4072 static const struct got_error *
4073 rebase_commit(struct got_object_id **new_commit_id,
4074     struct got_pathlist_head *merged_paths, struct got_reference *commit_ref,
4075     struct got_worktree *worktree, struct got_fileindex *fileindex,
4076     struct got_reference *tmp_branch, struct got_commit_object *orig_commit,
4077     const char *new_logmsg, struct got_repository *repo)
4078 {
4079 	const struct got_error *err, *sync_err;
4080 	struct got_pathlist_head commitable_paths;
4081 	struct collect_commitables_arg cc_arg;
4082 	char *fileindex_path = NULL;
4083 	struct got_reference *head_ref = NULL;
4084 	struct got_object_id *head_commit_id = NULL;
4085 	char *logmsg = NULL;
4086 
4087 	TAILQ_INIT(&commitable_paths);
4088 	*new_commit_id = NULL;
4089 
4090 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
4091 
4092 	err = get_fileindex_path(&fileindex_path, worktree);
4093 	if (err)
4094 		return err;
4095 
4096 	cc_arg.commitable_paths = &commitable_paths;
4097 	cc_arg.worktree = worktree;
4098 	cc_arg.repo = repo;
4099 	/*
4100 	 * If possible get the status of individual files directly to
4101 	 * avoid crawling the entire work tree once per rebased commit.
4102 	 * TODO: Ideally, merged_paths would contain a list of commitables
4103 	 * we could use so we could skip worktree_status() entirely.
4104 	 */
4105 	if (merged_paths) {
4106 		struct got_pathlist_entry *pe;
4107 		if (TAILQ_EMPTY(merged_paths)) {
4108 			err = got_error(GOT_ERR_NO_MERGED_PATHS);
4109 			goto done;
4110 		}
4111 		TAILQ_FOREACH(pe, merged_paths, entry) {
4112 			err = worktree_status(worktree, pe->path, fileindex,
4113 			    repo, collect_commitables, &cc_arg, NULL, NULL);
4114 			if (err)
4115 				goto done;
4116 		}
4117 	} else {
4118 		err = worktree_status(worktree, "", fileindex, repo,
4119 		    collect_commitables, &cc_arg, NULL, NULL);
4120 		if (err)
4121 			goto done;
4122 	}
4123 
4124 	if (TAILQ_EMPTY(&commitable_paths)) {
4125 		/* No-op change; commit will be elided. */
4126 		err = got_ref_delete(commit_ref, repo);
4127 		if (err)
4128 			goto done;
4129 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
4130 		goto done;
4131 	}
4132 
4133 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
4134 	if (err)
4135 		goto done;
4136 
4137 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
4138 	if (err)
4139 		goto done;
4140 
4141 	if (new_logmsg)
4142 		logmsg = strdup(new_logmsg);
4143 	else
4144 		logmsg = strdup(got_object_commit_get_logmsg(orig_commit));
4145 	if (logmsg == NULL)
4146 		return got_error_from_errno("strdup");
4147 
4148 	err = commit_worktree(new_commit_id, &commitable_paths, head_commit_id,
4149 	    worktree, NULL, got_object_commit_get_author(orig_commit),
4150 	    got_object_commit_get_committer(orig_commit),
4151 	    collect_rebase_commit_msg, logmsg, rebase_status, NULL, repo);
4152 	if (err)
4153 		goto done;
4154 
4155 	err = got_ref_change_ref(tmp_branch, *new_commit_id);
4156 	if (err)
4157 		goto done;
4158 
4159 	err = got_ref_delete(commit_ref, repo);
4160 	if (err)
4161 		goto done;
4162 
4163 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
4164 	    fileindex);
4165 	sync_err = sync_fileindex(fileindex, fileindex_path);
4166 	if (sync_err && err == NULL)
4167 		err = sync_err;
4168 done:
4169 	free(fileindex_path);
4170 	free(head_commit_id);
4171 	if (head_ref)
4172 		got_ref_close(head_ref);
4173 	if (err) {
4174 		free(*new_commit_id);
4175 		*new_commit_id = NULL;
4176 	}
4177 	return err;
4178 }
4179 
4180 const struct got_error *
4181 got_worktree_rebase_commit(struct got_object_id **new_commit_id,
4182     struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
4183     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4184     struct got_commit_object *orig_commit,
4185     struct got_object_id *orig_commit_id, struct got_repository *repo)
4186 {
4187 	const struct got_error *err;
4188 	char *commit_ref_name;
4189 	struct got_reference *commit_ref = NULL;
4190 	struct got_object_id *commit_id = NULL;
4191 
4192 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4193 	if (err)
4194 		return err;
4195 
4196 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4197 	if (err)
4198 		goto done;
4199 	err = got_ref_resolve(&commit_id, repo, commit_ref);
4200 	if (err)
4201 		goto done;
4202 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
4203 		err = got_error(GOT_ERR_REBASE_COMMITID);
4204 		goto done;
4205 	}
4206 
4207 	err = rebase_commit(new_commit_id, merged_paths, commit_ref,
4208 	    worktree, fileindex, tmp_branch, orig_commit, NULL, repo);
4209 done:
4210 	if (commit_ref)
4211 		got_ref_close(commit_ref);
4212 	free(commit_ref_name);
4213 	free(commit_id);
4214 	return err;
4215 }
4216 
4217 const struct got_error *
4218 got_worktree_histedit_commit(struct got_object_id **new_commit_id,
4219     struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
4220     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4221     struct got_commit_object *orig_commit,
4222     struct got_object_id *orig_commit_id, const char *new_logmsg,
4223     struct got_repository *repo)
4224 {
4225 	const struct got_error *err;
4226 	char *commit_ref_name;
4227 	struct got_reference *commit_ref = NULL;
4228 	struct got_object_id *commit_id = NULL;
4229 
4230 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4231 	if (err)
4232 		return err;
4233 
4234 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4235 	if (err)
4236 		goto done;
4237 	err = got_ref_resolve(&commit_id, repo, commit_ref);
4238 	if (err)
4239 		goto done;
4240 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
4241 		err = got_error(GOT_ERR_HISTEDIT_COMMITID);
4242 		goto done;
4243 	}
4244 
4245 	err = rebase_commit(new_commit_id, merged_paths, commit_ref,
4246 	    worktree, fileindex, tmp_branch, orig_commit, new_logmsg, repo);
4247 done:
4248 	if (commit_ref)
4249 		got_ref_close(commit_ref);
4250 	free(commit_ref_name);
4251 	free(commit_id);
4252 	return err;
4253 }
4254 
4255 const struct got_error *
4256 got_worktree_rebase_postpone(struct got_worktree *worktree,
4257     struct got_fileindex *fileindex)
4258 {
4259 	if (fileindex)
4260 		got_fileindex_free(fileindex);
4261 	return lock_worktree(worktree, LOCK_SH);
4262 }
4263 
4264 static const struct got_error *
4265 delete_ref(const char *name, struct got_repository *repo)
4266 {
4267 	const struct got_error *err;
4268 	struct got_reference *ref;
4269 
4270 	err = got_ref_open(&ref, repo, name, 0);
4271 	if (err) {
4272 		if (err->code == GOT_ERR_NOT_REF)
4273 			return NULL;
4274 		return err;
4275 	}
4276 
4277 	err = got_ref_delete(ref, repo);
4278 	got_ref_close(ref);
4279 	return err;
4280 }
4281 
4282 static const struct got_error *
4283 delete_rebase_refs(struct got_worktree *worktree, struct got_repository *repo)
4284 {
4285 	const struct got_error *err;
4286 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
4287 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
4288 
4289 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
4290 	if (err)
4291 		goto done;
4292 	err = delete_ref(tmp_branch_name, repo);
4293 	if (err)
4294 		goto done;
4295 
4296 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
4297 	if (err)
4298 		goto done;
4299 	err = delete_ref(new_base_branch_ref_name, repo);
4300 	if (err)
4301 		goto done;
4302 
4303 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
4304 	if (err)
4305 		goto done;
4306 	err = delete_ref(branch_ref_name, repo);
4307 	if (err)
4308 		goto done;
4309 
4310 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4311 	if (err)
4312 		goto done;
4313 	err = delete_ref(commit_ref_name, repo);
4314 	if (err)
4315 		goto done;
4316 
4317 done:
4318 	free(tmp_branch_name);
4319 	free(new_base_branch_ref_name);
4320 	free(branch_ref_name);
4321 	free(commit_ref_name);
4322 	return err;
4323 }
4324 
4325 const struct got_error *
4326 got_worktree_rebase_complete(struct got_worktree *worktree,
4327     struct got_fileindex *fileindex, struct got_reference *new_base_branch,
4328     struct got_reference *tmp_branch, struct got_reference *rebased_branch,
4329     struct got_repository *repo)
4330 {
4331 	const struct got_error *err, *unlockerr;
4332 	struct got_object_id *new_head_commit_id = NULL;
4333 
4334 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
4335 	if (err)
4336 		return err;
4337 
4338 	err = got_ref_change_ref(rebased_branch, new_head_commit_id);
4339 	if (err)
4340 		goto done;
4341 
4342 	err = got_ref_write(rebased_branch, repo);
4343 	if (err)
4344 		goto done;
4345 
4346 	err = got_worktree_set_head_ref(worktree, rebased_branch);
4347 	if (err)
4348 		goto done;
4349 
4350 	err = delete_rebase_refs(worktree, repo);
4351 done:
4352 	if (fileindex)
4353 		got_fileindex_free(fileindex);
4354 	free(new_head_commit_id);
4355 	unlockerr = lock_worktree(worktree, LOCK_SH);
4356 	if (unlockerr && err == NULL)
4357 		err = unlockerr;
4358 	return err;
4359 }
4360 
4361 struct collect_revertible_paths_arg {
4362 	struct got_pathlist_head *revertible_paths;
4363 	struct got_worktree *worktree;
4364 };
4365 
4366 static const struct got_error *
4367 collect_revertible_paths(void *arg, unsigned char status, const char *relpath,
4368     struct got_object_id *blob_id, struct got_object_id *commit_id)
4369 {
4370 	struct collect_revertible_paths_arg *a = arg;
4371 	const struct got_error *err = NULL;
4372 	struct got_pathlist_entry *new = NULL;
4373 	char *path = NULL;
4374 
4375 	if (status != GOT_STATUS_ADD &&
4376 	    status != GOT_STATUS_DELETE &&
4377 	    status != GOT_STATUS_MODIFY &&
4378 	    status != GOT_STATUS_CONFLICT &&
4379 	    status != GOT_STATUS_MISSING)
4380 		return NULL;
4381 
4382 	if (asprintf(&path, "%s/%s", a->worktree->root_path, relpath) == -1)
4383 		return got_error_from_errno("asprintf");
4384 
4385 	err = got_pathlist_insert(&new, a->revertible_paths, path, NULL);
4386 	if (err || new == NULL)
4387 		free(path);
4388 	return err;
4389 }
4390 
4391 const struct got_error *
4392 got_worktree_rebase_abort(struct got_worktree *worktree,
4393     struct got_fileindex *fileindex, struct got_repository *repo,
4394     struct got_reference *new_base_branch,
4395      got_worktree_checkout_cb progress_cb, void *progress_arg)
4396 {
4397 	const struct got_error *err, *unlockerr, *sync_err;
4398 	struct got_reference *resolved = NULL;
4399 	struct got_object_id *commit_id = NULL;
4400 	char *fileindex_path = NULL;
4401 	struct got_pathlist_head revertible_paths;
4402 	struct got_pathlist_entry *pe;
4403 	struct collect_revertible_paths_arg crp_arg;
4404 	struct got_object_id *tree_id = NULL;
4405 
4406 	TAILQ_INIT(&revertible_paths);
4407 
4408 	err = lock_worktree(worktree, LOCK_EX);
4409 	if (err)
4410 		return err;
4411 
4412 	err = got_ref_open(&resolved, repo,
4413 	    got_ref_get_symref_target(new_base_branch), 0);
4414 	if (err)
4415 		goto done;
4416 
4417 	err = got_worktree_set_head_ref(worktree, resolved);
4418 	if (err)
4419 		goto done;
4420 
4421 	/*
4422 	 * XXX commits to the base branch could have happened while
4423 	 * we were busy rebasing; should we store the original commit ID
4424 	 * when rebase begins and read it back here?
4425 	 */
4426 	err = got_ref_resolve(&commit_id, repo, resolved);
4427 	if (err)
4428 		goto done;
4429 
4430 	err = got_worktree_set_base_commit_id(worktree, repo, commit_id);
4431 	if (err)
4432 		goto done;
4433 
4434 	err = got_object_id_by_path(&tree_id, repo,
4435 	    worktree->base_commit_id, worktree->path_prefix);
4436 	if (err)
4437 		goto done;
4438 
4439 	err = delete_rebase_refs(worktree, repo);
4440 	if (err)
4441 		goto done;
4442 
4443 	err = get_fileindex_path(&fileindex_path, worktree);
4444 	if (err)
4445 		goto done;
4446 
4447 	crp_arg.revertible_paths = &revertible_paths;
4448 	crp_arg.worktree = worktree;
4449 	err = worktree_status(worktree, "", fileindex, repo,
4450 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4451 	if (err)
4452 		goto done;
4453 
4454 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4455 		err = revert_file(worktree, fileindex, pe->path,
4456 		    progress_cb, progress_arg, repo);
4457 		if (err)
4458 			goto sync;
4459 	}
4460 
4461 	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
4462 	    repo, progress_cb, progress_arg, NULL, NULL);
4463 sync:
4464 	sync_err = sync_fileindex(fileindex, fileindex_path);
4465 	if (sync_err && err == NULL)
4466 		err = sync_err;
4467 done:
4468 	got_ref_close(resolved);
4469 	free(tree_id);
4470 	free(commit_id);
4471 	if (fileindex)
4472 		got_fileindex_free(fileindex);
4473 	free(fileindex_path);
4474 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4475 		free((char *)pe->path);
4476 	got_pathlist_free(&revertible_paths);
4477 
4478 	unlockerr = lock_worktree(worktree, LOCK_SH);
4479 	if (unlockerr && err == NULL)
4480 		err = unlockerr;
4481 	return err;
4482 }
4483 
4484 const struct got_error *
4485 got_worktree_histedit_prepare(struct got_reference **tmp_branch,
4486     struct got_reference **branch_ref, struct got_object_id **base_commit_id,
4487     struct got_fileindex **fileindex, struct got_worktree *worktree,
4488     struct got_repository *repo)
4489 {
4490 	const struct got_error *err = NULL;
4491 	char *tmp_branch_name = NULL;
4492 	char *branch_ref_name = NULL;
4493 	char *base_commit_ref_name = NULL;
4494 	char *fileindex_path = NULL;
4495 	struct check_rebase_ok_arg ok_arg;
4496 	struct got_reference *wt_branch = NULL;
4497 	struct got_reference *base_commit_ref = NULL;
4498 
4499 	*tmp_branch = NULL;
4500 	*branch_ref = NULL;
4501 	*base_commit_id = NULL;
4502 	*fileindex = NULL;
4503 
4504 	err = lock_worktree(worktree, LOCK_EX);
4505 	if (err)
4506 		return err;
4507 
4508 	err = open_fileindex(fileindex, &fileindex_path, worktree);
4509 	if (err)
4510 		goto done;
4511 
4512 	ok_arg.worktree = worktree;
4513 	ok_arg.repo = repo;
4514 	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
4515 	    &ok_arg);
4516 	if (err)
4517 		goto done;
4518 
4519 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4520 	if (err)
4521 		goto done;
4522 
4523 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4524 	if (err)
4525 		goto done;
4526 
4527 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4528 	    worktree);
4529 	if (err)
4530 		goto done;
4531 
4532 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
4533 	    0);
4534 	if (err)
4535 		goto done;
4536 
4537 	err = got_ref_alloc_symref(branch_ref, branch_ref_name, wt_branch);
4538 	if (err)
4539 		goto done;
4540 
4541 	err = got_ref_write(*branch_ref, repo);
4542 	if (err)
4543 		goto done;
4544 
4545 	err = got_ref_alloc(&base_commit_ref, base_commit_ref_name,
4546 	    worktree->base_commit_id);
4547 	if (err)
4548 		goto done;
4549 	err = got_ref_write(base_commit_ref, repo);
4550 	if (err)
4551 		goto done;
4552 	*base_commit_id = got_object_id_dup(worktree->base_commit_id);
4553 	if (*base_commit_id == NULL) {
4554 		err = got_error_from_errno("got_object_id_dup");
4555 		goto done;
4556 	}
4557 
4558 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
4559 	    worktree->base_commit_id);
4560 	if (err)
4561 		goto done;
4562 	err = got_ref_write(*tmp_branch, repo);
4563 	if (err)
4564 		goto done;
4565 
4566 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
4567 	if (err)
4568 		goto done;
4569 done:
4570 	free(fileindex_path);
4571 	free(tmp_branch_name);
4572 	free(branch_ref_name);
4573 	free(base_commit_ref_name);
4574 	if (wt_branch)
4575 		got_ref_close(wt_branch);
4576 	if (err) {
4577 		if (*branch_ref) {
4578 			got_ref_close(*branch_ref);
4579 			*branch_ref = NULL;
4580 		}
4581 		if (*tmp_branch) {
4582 			got_ref_close(*tmp_branch);
4583 			*tmp_branch = NULL;
4584 		}
4585 		free(*base_commit_id);
4586 		if (*fileindex) {
4587 			got_fileindex_free(*fileindex);
4588 			*fileindex = NULL;
4589 		}
4590 		lock_worktree(worktree, LOCK_SH);
4591 	}
4592 	return err;
4593 }
4594 
4595 const struct got_error *
4596 got_worktree_histedit_postpone(struct got_worktree *worktree,
4597     struct got_fileindex *fileindex)
4598 {
4599 	if (fileindex)
4600 		got_fileindex_free(fileindex);
4601 	return lock_worktree(worktree, LOCK_SH);
4602 }
4603 
4604 const struct got_error *
4605 got_worktree_histedit_in_progress(int *in_progress,
4606     struct got_worktree *worktree)
4607 {
4608 	const struct got_error *err;
4609 	char *tmp_branch_name = NULL;
4610 
4611 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4612 	if (err)
4613 		return err;
4614 
4615 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
4616 	free(tmp_branch_name);
4617 	return NULL;
4618 }
4619 
4620 const struct got_error *
4621 got_worktree_histedit_continue(struct got_object_id **commit_id,
4622     struct got_reference **tmp_branch, struct got_reference **branch_ref,
4623     struct got_object_id **base_commit_id, struct got_fileindex **fileindex,
4624     struct got_worktree *worktree, struct got_repository *repo)
4625 {
4626 	const struct got_error *err;
4627 	char *commit_ref_name = NULL, *base_commit_ref_name = NULL;
4628 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
4629 	struct got_reference *commit_ref = NULL;
4630 	struct got_reference *base_commit_ref = NULL;
4631 	char *fileindex_path = NULL;
4632 
4633 	*commit_id = NULL;
4634 	*tmp_branch = NULL;
4635 	*base_commit_id = NULL;
4636 	*fileindex = NULL;
4637 
4638 	err = lock_worktree(worktree, LOCK_EX);
4639 	if (err)
4640 		return err;
4641 
4642 	err = open_fileindex(fileindex, &fileindex_path, worktree);
4643 	if (err)
4644 		goto done;
4645 
4646 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4647 	if (err)
4648 		return err;
4649 
4650 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4651 	if (err)
4652 		goto done;
4653 
4654 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4655 	if (err)
4656 		goto done;
4657 
4658 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4659 	    worktree);
4660 	if (err)
4661 		goto done;
4662 
4663 	err = got_ref_open(branch_ref, repo, branch_ref_name, 0);
4664 	if (err)
4665 		goto done;
4666 
4667 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4668 	if (err)
4669 		goto done;
4670 	err = got_ref_resolve(commit_id, repo, commit_ref);
4671 	if (err)
4672 		goto done;
4673 
4674 	err = got_ref_open(&base_commit_ref, repo, base_commit_ref_name, 0);
4675 	if (err)
4676 		goto done;
4677 	err = got_ref_resolve(base_commit_id, repo, base_commit_ref);
4678 	if (err)
4679 		goto done;
4680 
4681 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
4682 	if (err)
4683 		goto done;
4684 done:
4685 	free(commit_ref_name);
4686 	free(branch_ref_name);
4687 	free(fileindex_path);
4688 	if (commit_ref)
4689 		got_ref_close(commit_ref);
4690 	if (base_commit_ref)
4691 		got_ref_close(base_commit_ref);
4692 	if (err) {
4693 		free(*commit_id);
4694 		*commit_id = NULL;
4695 		free(*base_commit_id);
4696 		*base_commit_id = NULL;
4697 		if (*tmp_branch) {
4698 			got_ref_close(*tmp_branch);
4699 			*tmp_branch = NULL;
4700 		}
4701 		if (*fileindex) {
4702 			got_fileindex_free(*fileindex);
4703 			*fileindex = NULL;
4704 		}
4705 		lock_worktree(worktree, LOCK_EX);
4706 	}
4707 	return err;
4708 }
4709 
4710 static const struct got_error *
4711 delete_histedit_refs(struct got_worktree *worktree, struct got_repository *repo)
4712 {
4713 	const struct got_error *err;
4714 	char *tmp_branch_name = NULL, *base_commit_ref_name = NULL;
4715 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
4716 
4717 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4718 	if (err)
4719 		goto done;
4720 	err = delete_ref(tmp_branch_name, repo);
4721 	if (err)
4722 		goto done;
4723 
4724 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4725 	    worktree);
4726 	if (err)
4727 		goto done;
4728 	err = delete_ref(base_commit_ref_name, repo);
4729 	if (err)
4730 		goto done;
4731 
4732 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4733 	if (err)
4734 		goto done;
4735 	err = delete_ref(branch_ref_name, repo);
4736 	if (err)
4737 		goto done;
4738 
4739 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4740 	if (err)
4741 		goto done;
4742 	err = delete_ref(commit_ref_name, repo);
4743 	if (err)
4744 		goto done;
4745 done:
4746 	free(tmp_branch_name);
4747 	free(base_commit_ref_name);
4748 	free(branch_ref_name);
4749 	free(commit_ref_name);
4750 	return err;
4751 }
4752 
4753 const struct got_error *
4754 got_worktree_histedit_abort(struct got_worktree *worktree,
4755     struct got_fileindex *fileindex, struct got_repository *repo,
4756     struct got_reference *branch, struct got_object_id *base_commit_id,
4757     got_worktree_checkout_cb progress_cb, void *progress_arg)
4758 {
4759 	const struct got_error *err, *unlockerr, *sync_err;
4760 	struct got_reference *resolved = NULL;
4761 	char *fileindex_path = NULL;
4762 	struct got_pathlist_head revertible_paths;
4763 	struct got_pathlist_entry *pe;
4764 	struct collect_revertible_paths_arg crp_arg;
4765 	struct got_object_id *tree_id = NULL;
4766 
4767 	TAILQ_INIT(&revertible_paths);
4768 
4769 	err = lock_worktree(worktree, LOCK_EX);
4770 	if (err)
4771 		return err;
4772 
4773 	err = got_ref_open(&resolved, repo,
4774 	    got_ref_get_symref_target(branch), 0);
4775 	if (err)
4776 		goto done;
4777 
4778 	err = got_worktree_set_head_ref(worktree, resolved);
4779 	if (err)
4780 		goto done;
4781 
4782 	err = got_worktree_set_base_commit_id(worktree, repo, base_commit_id);
4783 	if (err)
4784 		goto done;
4785 
4786 	err = got_object_id_by_path(&tree_id, repo, base_commit_id,
4787 	    worktree->path_prefix);
4788 	if (err)
4789 		goto done;
4790 
4791 	err = delete_histedit_refs(worktree, repo);
4792 	if (err)
4793 		goto done;
4794 
4795 	err = get_fileindex_path(&fileindex_path, worktree);
4796 	if (err)
4797 		goto done;
4798 
4799 	crp_arg.revertible_paths = &revertible_paths;
4800 	crp_arg.worktree = worktree;
4801 	err = worktree_status(worktree, "", fileindex, repo,
4802 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4803 	if (err)
4804 		goto done;
4805 
4806 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4807 		err = revert_file(worktree, fileindex, pe->path,
4808 		    progress_cb, progress_arg, repo);
4809 		if (err)
4810 			goto sync;
4811 	}
4812 
4813 	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
4814 	    repo, progress_cb, progress_arg, NULL, NULL);
4815 sync:
4816 	sync_err = sync_fileindex(fileindex, fileindex_path);
4817 	if (sync_err && err == NULL)
4818 		err = sync_err;
4819 done:
4820 	got_ref_close(resolved);
4821 	free(tree_id);
4822 	free(fileindex_path);
4823 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4824 		free((char *)pe->path);
4825 	got_pathlist_free(&revertible_paths);
4826 
4827 	unlockerr = lock_worktree(worktree, LOCK_SH);
4828 	if (unlockerr && err == NULL)
4829 		err = unlockerr;
4830 	return err;
4831 }
4832 
4833 const struct got_error *
4834 got_worktree_histedit_complete(struct got_worktree *worktree,
4835     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4836     struct got_reference *edited_branch, struct got_repository *repo)
4837 {
4838 	const struct got_error *err, *unlockerr;
4839 	struct got_object_id *new_head_commit_id = NULL;
4840 	struct got_reference *resolved = NULL;
4841 
4842 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
4843 	if (err)
4844 		return err;
4845 
4846 	err = got_ref_open(&resolved, repo,
4847 	    got_ref_get_symref_target(edited_branch), 0);
4848 	if (err)
4849 		goto done;
4850 
4851 	err = got_ref_change_ref(resolved, new_head_commit_id);
4852 	if (err)
4853 		goto done;
4854 
4855 	err = got_ref_write(resolved, repo);
4856 	if (err)
4857 		goto done;
4858 
4859 	err = got_worktree_set_head_ref(worktree, resolved);
4860 	if (err)
4861 		goto done;
4862 
4863 	err = delete_histedit_refs(worktree, repo);
4864 done:
4865 	if (fileindex)
4866 		got_fileindex_free(fileindex);
4867 	free(new_head_commit_id);
4868 	unlockerr = lock_worktree(worktree, LOCK_SH);
4869 	if (unlockerr && err == NULL)
4870 		err = unlockerr;
4871 	return err;
4872 }
4873 
4874 const struct got_error *
4875 got_worktree_histedit_skip_commit(struct got_worktree *worktree,
4876     struct got_object_id *commit_id, struct got_repository *repo)
4877 {
4878 	const struct got_error *err;
4879 	char *commit_ref_name;
4880 
4881 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4882 	if (err)
4883 		return err;
4884 
4885 	err = store_commit_id(commit_ref_name, commit_id, repo);
4886 	if (err)
4887 		goto done;
4888 
4889 	err = delete_ref(commit_ref_name, repo);
4890 done:
4891 	free(commit_ref_name);
4892 	return err;
4893 }