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 (ie) {
1054 				if (got_fileindex_entry_has_file_on_disk(ie))
1055 					*status = GOT_STATUS_MISSING;
1056 				else
1057 					*status = GOT_STATUS_DELETE;
1058 				sb->st_mode =
1059 				    ((ie->mode >> GOT_FILEIDX_MODE_PERMS_SHIFT)
1060 				    & (S_IRWXU | S_IRWXG | S_IRWXO));
1061 			} else
1062 				sb->st_mode = GOT_DEFAULT_FILE_MODE;
1063 			return NULL;
1064 		}
1065 		return got_error_from_errno2("lstat", abspath);
1066 	}
1067 
1068 	if (!S_ISREG(sb->st_mode)) {
1069 		*status = GOT_STATUS_OBSTRUCTED;
1070 		return NULL;
1071 	}
1072 
1073 	if (ie == NULL)
1074 		return NULL;
1075 
1076 	if (!got_fileindex_entry_has_file_on_disk(ie)) {
1077 		*status = GOT_STATUS_DELETE;
1078 		return NULL;
1079 	} else if (!got_fileindex_entry_has_blob(ie)) {
1080 		*status = GOT_STATUS_ADD;
1081 		return NULL;
1082 	}
1083 
1084 	if (!stat_info_differs(ie, sb))
1085 		return NULL;
1086 
1087 	memcpy(id.sha1, ie->blob_sha1, sizeof(id.sha1));
1088 	err = got_object_open_as_blob(&blob, repo, &id, sizeof(fbuf));
1089 	if (err)
1090 		return err;
1091 
1092 	f = fopen(abspath, "r");
1093 	if (f == NULL) {
1094 		err = got_error_from_errno2("fopen", abspath);
1095 		goto done;
1096 	}
1097 	hdrlen = got_object_blob_get_hdrlen(blob);
1098 	for (;;) {
1099 		const uint8_t *bbuf = got_object_blob_get_read_buf(blob);
1100 		err = got_object_blob_read_block(&blen, blob);
1101 		if (err)
1102 			goto done;
1103 		/* Skip length of blob object header first time around. */
1104 		flen = fread(fbuf, 1, sizeof(fbuf) - hdrlen, f);
1105 		if (flen == 0 && ferror(f)) {
1106 			err = got_error_from_errno("fread");
1107 			goto done;
1108 		}
1109 		if (blen == 0) {
1110 			if (flen != 0)
1111 				*status = GOT_STATUS_MODIFY;
1112 			break;
1113 		} else if (flen == 0) {
1114 			if (blen != 0)
1115 				*status = GOT_STATUS_MODIFY;
1116 			break;
1117 		} else if (blen - hdrlen == flen) {
1118 			/* Skip blob object header first time around. */
1119 			if (memcmp(bbuf + hdrlen, fbuf, flen) != 0) {
1120 				*status = GOT_STATUS_MODIFY;
1121 				break;
1122 			}
1123 		} else {
1124 			*status = GOT_STATUS_MODIFY;
1125 			break;
1126 		}
1127 		hdrlen = 0;
1128 	}
1129 
1130 	if (*status == GOT_STATUS_MODIFY) {
1131 		rewind(f);
1132 		err = get_modified_file_content_status(status, f);
1133 	}
1134 done:
1135 	if (blob)
1136 		got_object_blob_close(blob);
1137 	if (f)
1138 		fclose(f);
1139 	return err;
1140 }
1141 
1142 /*
1143  * Update timestamps in the file index if a file is unmodified and
1144  * we had to run a full content comparison to find out.
1145  */
1146 static const struct got_error *
1147 sync_timestamps(char *ondisk_path, unsigned char status,
1148     struct got_fileindex_entry *ie, struct stat *sb)
1149 {
1150 	if (status == GOT_STATUS_NO_CHANGE && stat_info_differs(ie, sb))
1151 		return got_fileindex_entry_update(ie, ondisk_path,
1152 		    ie->blob_sha1, ie->commit_sha1, 1);
1153 
1154 	return NULL;
1155 }
1156 
1157 static const struct got_error *
1158 update_blob(struct got_worktree *worktree,
1159     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
1160     struct got_tree_entry *te, const char *path,
1161     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1162     void *progress_arg)
1163 {
1164 	const struct got_error *err = NULL;
1165 	struct got_blob_object *blob = NULL;
1166 	char *ondisk_path;
1167 	unsigned char status = GOT_STATUS_NO_CHANGE;
1168 	struct stat sb;
1169 
1170 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
1171 		return got_error_from_errno("asprintf");
1172 
1173 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1174 	if (err)
1175 		goto done;
1176 
1177 	if (status == GOT_STATUS_OBSTRUCTED) {
1178 		err = (*progress_cb)(progress_arg, status, path);
1179 		goto done;
1180 	}
1181 
1182 	if (ie && status != GOT_STATUS_MISSING) {
1183 		if (got_fileindex_entry_has_commit(ie) &&
1184 		    memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
1185 		    SHA1_DIGEST_LENGTH) == 0) {
1186 			err = sync_timestamps(ondisk_path, status, ie, &sb);
1187 			if (err)
1188 				goto done;
1189 			err = (*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
1190 			    path);
1191 			goto done;
1192 		}
1193 		if (got_fileindex_entry_has_blob(ie) &&
1194 		    memcmp(ie->blob_sha1, te->id->sha1,
1195 		    SHA1_DIGEST_LENGTH) == 0) {
1196 			err = sync_timestamps(ondisk_path, status, ie, &sb);
1197 			goto done;
1198 		}
1199 	}
1200 
1201 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
1202 	if (err)
1203 		goto done;
1204 
1205 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_ADD) {
1206 		int update_timestamps;
1207 		struct got_blob_object *blob2 = NULL;
1208 		if (got_fileindex_entry_has_blob(ie)) {
1209 			struct got_object_id id2;
1210 			memcpy(id2.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1211 			err = got_object_open_as_blob(&blob2, repo, &id2, 8192);
1212 			if (err)
1213 				goto done;
1214 		}
1215 		err = merge_blob(&update_timestamps, worktree, blob2,
1216 		    ondisk_path, path, sb.st_mode, blob,
1217 		    worktree->base_commit_id, repo,
1218 		    progress_cb, progress_arg);
1219 		if (blob2)
1220 			got_object_blob_close(blob2);
1221 		/*
1222 		 * Do not update timestamps of files with local changes.
1223 		 * Otherwise, a future status walk would treat them as
1224 		 * unmodified files again.
1225 		 */
1226 		err = got_fileindex_entry_update(ie, ondisk_path,
1227 		    blob->id.sha1, worktree->base_commit_id->sha1,
1228 		    update_timestamps);
1229 	} else if (status == GOT_STATUS_DELETE) {
1230 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, path);
1231 		if (err)
1232 			goto done;
1233 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1234 		    ondisk_path, path, blob, 0);
1235 		if (err)
1236 			goto done;
1237 	} else {
1238 		err = install_blob(worktree, ondisk_path, path, te->mode,
1239 		    sb.st_mode, blob, status == GOT_STATUS_MISSING, 0,
1240 		    repo, progress_cb, progress_arg);
1241 		if (err)
1242 			goto done;
1243 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1244 		    ondisk_path, path, blob, 1);
1245 		if (err)
1246 			goto done;
1247 	}
1248 	got_object_blob_close(blob);
1249 done:
1250 	free(ondisk_path);
1251 	return err;
1252 }
1253 
1254 static const struct got_error *
1255 remove_ondisk_file(const char *root_path, const char *path)
1256 {
1257 	const struct got_error *err = NULL;
1258 	char *ondisk_path = NULL;
1259 
1260 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
1261 		return got_error_from_errno("asprintf");
1262 
1263 	if (unlink(ondisk_path) == -1) {
1264 		if (errno != ENOENT)
1265 			err = got_error_from_errno2("unlink", ondisk_path);
1266 	} else {
1267 		char *parent = dirname(ondisk_path);
1268 		while (parent && strcmp(parent, root_path) != 0) {
1269 			if (rmdir(parent) == -1) {
1270 				if (errno != ENOTEMPTY)
1271 					err = got_error_from_errno2("rmdir",
1272 					    parent);
1273 				break;
1274 			}
1275 			parent = dirname(parent);
1276 		}
1277 	}
1278 	free(ondisk_path);
1279 	return err;
1280 }
1281 
1282 static const struct got_error *
1283 delete_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
1284     struct got_fileindex_entry *ie, struct got_repository *repo,
1285     got_worktree_checkout_cb progress_cb, void *progress_arg)
1286 {
1287 	const struct got_error *err = NULL;
1288 	unsigned char status;
1289 	struct stat sb;
1290 	char *ondisk_path;
1291 
1292 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, ie->path)
1293 	    == -1)
1294 		return got_error_from_errno("asprintf");
1295 
1296 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1297 	if (err)
1298 		return err;
1299 
1300 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_CONFLICT ||
1301 	    status == GOT_STATUS_ADD) {
1302 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, ie->path);
1303 		if (err)
1304 			return err;
1305 		/*
1306 		 * Preserve the working file and change the deleted blob's
1307 		 * entry into a schedule-add entry.
1308 		 */
1309 		err = got_fileindex_entry_update(ie, ondisk_path, NULL, NULL,
1310 		    0);
1311 		if (err)
1312 			return err;
1313 	} else {
1314 		err = (*progress_cb)(progress_arg, GOT_STATUS_DELETE, ie->path);
1315 		if (err)
1316 			return err;
1317 		if (status == GOT_STATUS_NO_CHANGE) {
1318 			err = remove_ondisk_file(worktree->root_path, ie->path);
1319 			if (err)
1320 				return err;
1321 		}
1322 		got_fileindex_entry_remove(fileindex, ie);
1323 	}
1324 
1325 	return err;
1326 }
1327 
1328 struct diff_cb_arg {
1329     struct got_fileindex *fileindex;
1330     struct got_worktree *worktree;
1331     struct got_repository *repo;
1332     got_worktree_checkout_cb progress_cb;
1333     void *progress_arg;
1334     got_worktree_cancel_cb cancel_cb;
1335     void *cancel_arg;
1336 };
1337 
1338 static const struct got_error *
1339 diff_old_new(void *arg, struct got_fileindex_entry *ie,
1340     struct got_tree_entry *te, const char *parent_path)
1341 {
1342 	struct diff_cb_arg *a = arg;
1343 
1344 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1345 		return got_error(GOT_ERR_CANCELLED);
1346 
1347 	return update_blob(a->worktree, a->fileindex, ie, te,
1348 	    ie->path, a->repo, a->progress_cb, a->progress_arg);
1349 }
1350 
1351 static const struct got_error *
1352 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1353 {
1354 	struct diff_cb_arg *a = arg;
1355 
1356 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1357 		return got_error(GOT_ERR_CANCELLED);
1358 
1359 	return delete_blob(a->worktree, a->fileindex, ie,
1360 	    a->repo, a->progress_cb, a->progress_arg);
1361 }
1362 
1363 static const struct got_error *
1364 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
1365 {
1366 	struct diff_cb_arg *a = arg;
1367 	const struct got_error *err;
1368 	char *path;
1369 
1370 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1371 		return got_error(GOT_ERR_CANCELLED);
1372 
1373 	if (asprintf(&path, "%s%s%s", parent_path,
1374 	    parent_path[0] ? "/" : "", te->name)
1375 	    == -1)
1376 		return got_error_from_errno("asprintf");
1377 
1378 	if (S_ISDIR(te->mode))
1379 		err = add_dir_on_disk(a->worktree, path);
1380 	else
1381 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
1382 		    a->repo, a->progress_cb, a->progress_arg);
1383 
1384 	free(path);
1385 	return err;
1386 }
1387 
1388 static const struct got_error *
1389 get_ref_name(char **refname, struct got_worktree *worktree, const char *prefix)
1390 {
1391 	const struct got_error *err = NULL;
1392 	char *uuidstr = NULL;
1393 	uint32_t uuid_status;
1394 
1395 	*refname = NULL;
1396 
1397 	uuid_to_string(&worktree->uuid, &uuidstr, &uuid_status);
1398 	if (uuid_status != uuid_s_ok)
1399 		return got_error_uuid(uuid_status);
1400 
1401 	if (asprintf(refname, "%s-%s", prefix, uuidstr)
1402 	    == -1) {
1403 		err = got_error_from_errno("asprintf");
1404 		*refname = NULL;
1405 	}
1406 	free(uuidstr);
1407 	return err;
1408 }
1409 
1410 const struct got_error *
1411 got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
1412 {
1413 	return get_ref_name(refname, worktree, GOT_WORKTREE_BASE_REF_PREFIX);
1414 }
1415 
1416 static const struct got_error *
1417 get_rebase_tmp_ref_name(char **refname, struct got_worktree *worktree)
1418 {
1419 	return get_ref_name(refname, worktree,
1420 	    GOT_WORKTREE_REBASE_TMP_REF_PREFIX);
1421 }
1422 
1423 static const struct got_error *
1424 get_newbase_symref_name(char **refname, struct got_worktree *worktree)
1425 {
1426 	return get_ref_name(refname, worktree, GOT_WORKTREE_NEWBASE_REF_PREFIX);
1427 }
1428 
1429 static const struct got_error *
1430 get_rebase_branch_symref_name(char **refname, struct got_worktree *worktree)
1431 {
1432 	return get_ref_name(refname, worktree,
1433 	    GOT_WORKTREE_REBASE_BRANCH_REF_PREFIX);
1434 }
1435 
1436 static const struct got_error *
1437 get_rebase_commit_ref_name(char **refname, struct got_worktree *worktree)
1438 {
1439 	return get_ref_name(refname, worktree,
1440 	    GOT_WORKTREE_REBASE_COMMIT_REF_PREFIX);
1441 }
1442 
1443 static const struct got_error *
1444 get_histedit_tmp_ref_name(char **refname, struct got_worktree *worktree)
1445 {
1446 	return get_ref_name(refname, worktree,
1447 	    GOT_WORKTREE_HISTEDIT_TMP_REF_PREFIX);
1448 }
1449 
1450 static const struct got_error *
1451 get_histedit_branch_symref_name(char **refname, struct got_worktree *worktree)
1452 {
1453 	return get_ref_name(refname, worktree,
1454 	    GOT_WORKTREE_HISTEDIT_BRANCH_REF_PREFIX);
1455 }
1456 
1457 static const struct got_error *
1458 get_histedit_base_commit_ref_name(char **refname, struct got_worktree *worktree)
1459 {
1460 	return get_ref_name(refname, worktree,
1461 	    GOT_WORKTREE_HISTEDIT_BASE_COMMIT_REF_PREFIX);
1462 }
1463 
1464 static const struct got_error *
1465 get_histedit_commit_ref_name(char **refname, struct got_worktree *worktree)
1466 {
1467 	return get_ref_name(refname, worktree,
1468 	    GOT_WORKTREE_HISTEDIT_COMMIT_REF_PREFIX);
1469 }
1470 
1471 const struct got_error *
1472 got_worktree_get_histedit_list_path(char **path, struct got_worktree *worktree)
1473 {
1474 	if (asprintf(path, "%s/%s/%s", worktree->root_path,
1475 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_HISTEDIT_LIST) == -1) {
1476 		*path = NULL;
1477 		return got_error_from_errno("asprintf");
1478 	}
1479 	return NULL;
1480 }
1481 
1482 /*
1483  * Prevent Git's garbage collector from deleting our base commit by
1484  * setting a reference to our base commit's ID.
1485  */
1486 static const struct got_error *
1487 ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
1488 {
1489 	const struct got_error *err = NULL;
1490 	struct got_reference *ref = NULL;
1491 	char *refname;
1492 
1493 	err = got_worktree_get_base_ref_name(&refname, worktree);
1494 	if (err)
1495 		return err;
1496 
1497 	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
1498 	if (err)
1499 		goto done;
1500 
1501 	err = got_ref_write(ref, repo);
1502 done:
1503 	free(refname);
1504 	if (ref)
1505 		got_ref_close(ref);
1506 	return err;
1507 }
1508 
1509 static const struct got_error *
1510 get_fileindex_path(char **fileindex_path, struct got_worktree *worktree)
1511 {
1512 	const struct got_error *err = NULL;
1513 
1514 	if (asprintf(fileindex_path, "%s/%s/%s", worktree->root_path,
1515 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1516 		err = got_error_from_errno("asprintf");
1517 		*fileindex_path = NULL;
1518 	}
1519 	return err;
1520 }
1521 
1522 
1523 static const struct got_error *
1524 open_fileindex(struct got_fileindex **fileindex, char **fileindex_path,
1525    struct got_worktree *worktree)
1526 {
1527 	const struct got_error *err = NULL;
1528 	FILE *index = NULL;
1529 
1530 	*fileindex_path = NULL;
1531 	*fileindex = got_fileindex_alloc();
1532 	if (*fileindex == NULL)
1533 		return got_error_from_errno("got_fileindex_alloc");
1534 
1535 	err = get_fileindex_path(fileindex_path, worktree);
1536 	if (err)
1537 		goto done;
1538 
1539 	index = fopen(*fileindex_path, "rb");
1540 	if (index == NULL) {
1541 		if (errno != ENOENT)
1542 			err = got_error_from_errno2("fopen", *fileindex_path);
1543 	} else {
1544 		err = got_fileindex_read(*fileindex, index);
1545 		if (fclose(index) != 0 && err == NULL)
1546 			err = got_error_from_errno("fclose");
1547 	}
1548 done:
1549 	if (err) {
1550 		free(*fileindex_path);
1551 		*fileindex_path = NULL;
1552 		got_fileindex_free(*fileindex);
1553 		*fileindex = NULL;
1554 	}
1555 	return err;
1556 }
1557 
1558 struct bump_base_commit_id_arg {
1559 	struct got_object_id *base_commit_id;
1560 	const char *path;
1561 	size_t path_len;
1562 	const char *entry_name;
1563 	got_worktree_checkout_cb progress_cb;
1564 	void *progress_arg;
1565 };
1566 
1567 /* Bump base commit ID of all files within an updated part of the work tree. */
1568 static const struct got_error *
1569 bump_base_commit_id(void *arg, struct got_fileindex_entry *ie)
1570 {
1571 	const struct got_error *err;
1572 	struct bump_base_commit_id_arg *a = arg;
1573 
1574 	if (a->entry_name) {
1575 		if (strcmp(ie->path, a->path) != 0)
1576 			return NULL;
1577 	} else if (!got_path_is_child(ie->path, a->path, a->path_len))
1578 		return NULL;
1579 
1580 	if (memcmp(ie->commit_sha1, a->base_commit_id->sha1,
1581 	    SHA1_DIGEST_LENGTH) == 0)
1582 		return NULL;
1583 
1584 	if (a->progress_cb) {
1585 		err = (*a->progress_cb)(a->progress_arg, GOT_STATUS_BUMP_BASE,
1586 		    ie->path);
1587 		if (err)
1588 			return err;
1589 	}
1590 	memcpy(ie->commit_sha1, a->base_commit_id->sha1, SHA1_DIGEST_LENGTH);
1591 	return NULL;
1592 }
1593 
1594 static const struct got_error *
1595 sync_fileindex(struct got_fileindex *fileindex, const char *fileindex_path)
1596 {
1597 	const struct got_error *err = NULL;
1598 	char *new_fileindex_path = NULL;
1599 	FILE *new_index = NULL;
1600 
1601 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1602 	    fileindex_path);
1603 	if (err)
1604 		goto done;
1605 
1606 	err = got_fileindex_write(fileindex, new_index);
1607 	if (err)
1608 		goto done;
1609 
1610 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1611 		err = got_error_from_errno3("rename", new_fileindex_path,
1612 		    fileindex_path);
1613 		unlink(new_fileindex_path);
1614 	}
1615 done:
1616 	if (new_index)
1617 		fclose(new_index);
1618 	free(new_fileindex_path);
1619 	return err;
1620 }
1621 
1622 static const struct got_error *
1623 find_tree_entry_for_checkout(int *entry_type, char **tree_relpath,
1624     struct got_object_id **tree_id, const char *wt_relpath,
1625     struct got_worktree *worktree, struct got_repository *repo)
1626 {
1627 	const struct got_error *err = NULL;
1628 	struct got_object_id *id = NULL;
1629 	char *in_repo_path = NULL;
1630 	int is_root_wt = got_path_is_root_dir(worktree->path_prefix);
1631 
1632 	*entry_type = GOT_OBJ_TYPE_ANY;
1633 	*tree_relpath = NULL;
1634 	*tree_id = NULL;
1635 
1636 	if (wt_relpath[0] == '\0') {
1637 		/* Check out all files within the work tree. */
1638 		*entry_type = GOT_OBJ_TYPE_TREE;
1639 		*tree_relpath = strdup("");
1640 		if (*tree_relpath == NULL) {
1641 			err = got_error_from_errno("strdup");
1642 			goto done;
1643 		}
1644 		err = got_object_id_by_path(tree_id, repo,
1645 		    worktree->base_commit_id, worktree->path_prefix);
1646 		if (err)
1647 			goto done;
1648 		return NULL;
1649 	}
1650 
1651 	/* Check out a subset of files in the work tree. */
1652 
1653 	if (asprintf(&in_repo_path, "%s%s%s", worktree->path_prefix,
1654 	    is_root_wt ? "" : "/", wt_relpath) == -1) {
1655 		err = got_error_from_errno("asprintf");
1656 		goto done;
1657 	}
1658 
1659 	err = got_object_id_by_path(&id, repo, worktree->base_commit_id,
1660 	    in_repo_path);
1661 	if (err)
1662 		goto done;
1663 
1664 	free(in_repo_path);
1665 	in_repo_path = NULL;
1666 
1667 	err = got_object_get_type(entry_type, repo, id);
1668 	if (err)
1669 		goto done;
1670 
1671 	if (*entry_type == GOT_OBJ_TYPE_BLOB) {
1672 		/* Check out a single file. */
1673 		if (strchr(wt_relpath, '/')  == NULL) {
1674 			/* Check out a single file in work tree's root dir. */
1675 			in_repo_path = strdup(worktree->path_prefix);
1676 			if (in_repo_path == NULL) {
1677 				err = got_error_from_errno("strdup");
1678 				goto done;
1679 			}
1680 			*tree_relpath = strdup("");
1681 			if (*tree_relpath == NULL) {
1682 				err = got_error_from_errno("strdup");
1683 				goto done;
1684 			}
1685 		} else {
1686 			/* Check out a single file in a subdirectory. */
1687 			err = got_path_dirname(tree_relpath, wt_relpath);
1688 			if (err)
1689 				return err;
1690 			if (asprintf(&in_repo_path, "%s%s%s",
1691 			    worktree->path_prefix, is_root_wt ? "" : "/",
1692 			    *tree_relpath) == -1) {
1693 				err = got_error_from_errno("asprintf");
1694 				goto done;
1695 			}
1696 		}
1697 		err = got_object_id_by_path(tree_id, repo,
1698 		    worktree->base_commit_id, in_repo_path);
1699 	} else {
1700 		/* Check out all files within a subdirectory. */
1701 		*tree_id = got_object_id_dup(id);
1702 		if (*tree_id == NULL) {
1703 			err = got_error_from_errno("got_object_id_dup");
1704 			goto done;
1705 		}
1706 		*tree_relpath = strdup(wt_relpath);
1707 		if (*tree_relpath == NULL) {
1708 			err = got_error_from_errno("strdup");
1709 			goto done;
1710 		}
1711 	}
1712 done:
1713 	free(id);
1714 	free(in_repo_path);
1715 	if (err) {
1716 		*entry_type = GOT_OBJ_TYPE_ANY;
1717 		free(*tree_relpath);
1718 		*tree_relpath = NULL;
1719 		free(*tree_id);
1720 		*tree_id = NULL;
1721 	}
1722 	return err;
1723 }
1724 
1725 static const struct got_error *
1726 checkout_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
1727     const char *relpath, struct got_object_id *tree_id, const char *entry_name,
1728     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1729     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1730 {
1731 	const struct got_error *err = NULL;
1732 	struct got_commit_object *commit = NULL;
1733 	struct got_tree_object *tree = NULL;
1734 	struct got_fileindex_diff_tree_cb diff_cb;
1735 	struct diff_cb_arg arg;
1736 
1737 	err = ref_base_commit(worktree, repo);
1738 	if (err)
1739 		goto done;
1740 
1741 	err = got_object_open_as_commit(&commit, repo,
1742 	   worktree->base_commit_id);
1743 	if (err)
1744 		goto done;
1745 
1746 	err = got_object_open_as_tree(&tree, repo, tree_id);
1747 	if (err)
1748 		goto done;
1749 
1750 	if (entry_name &&
1751 	    got_object_tree_find_entry(tree, entry_name) == NULL) {
1752 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
1753 		goto done;
1754 	}
1755 
1756 	diff_cb.diff_old_new = diff_old_new;
1757 	diff_cb.diff_old = diff_old;
1758 	diff_cb.diff_new = diff_new;
1759 	arg.fileindex = fileindex;
1760 	arg.worktree = worktree;
1761 	arg.repo = repo;
1762 	arg.progress_cb = progress_cb;
1763 	arg.progress_arg = progress_arg;
1764 	arg.cancel_cb = cancel_cb;
1765 	arg.cancel_arg = cancel_arg;
1766 	err = got_fileindex_diff_tree(fileindex, tree, relpath,
1767 	    entry_name, repo, &diff_cb, &arg);
1768 done:
1769 	if (tree)
1770 		got_object_tree_close(tree);
1771 	if (commit)
1772 		got_object_commit_close(commit);
1773 	return err;
1774 }
1775 
1776 const struct got_error *
1777 got_worktree_checkout_files(struct got_worktree *worktree,
1778     struct got_pathlist_head *paths, struct got_repository *repo,
1779     got_worktree_checkout_cb progress_cb, void *progress_arg,
1780     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1781 {
1782 	const struct got_error *err = NULL, *sync_err, *unlockerr;
1783 	struct got_commit_object *commit = NULL;
1784 	struct got_tree_object *tree = NULL;
1785 	struct got_fileindex *fileindex = NULL;
1786 	char *fileindex_path = NULL;
1787 	struct got_pathlist_entry *pe;
1788 	struct tree_path_data {
1789 		SIMPLEQ_ENTRY(tree_path_data) entry;
1790 		struct got_object_id *tree_id;
1791 		int entry_type;
1792 		char *relpath;
1793 		char *entry_name;
1794 	} *tpd = NULL;
1795 	SIMPLEQ_HEAD(tree_paths, tree_path_data) tree_paths;
1796 
1797 	SIMPLEQ_INIT(&tree_paths);
1798 
1799 	err = lock_worktree(worktree, LOCK_EX);
1800 	if (err)
1801 		return err;
1802 
1803 	/* Map all specified paths to in-repository trees. */
1804 	TAILQ_FOREACH(pe, paths, entry) {
1805 		tpd = malloc(sizeof(*tpd));
1806 		if (tpd == NULL) {
1807 			err = got_error_from_errno("malloc");
1808 			goto done;
1809 		}
1810 
1811 		err = find_tree_entry_for_checkout(&tpd->entry_type,
1812 		    &tpd->relpath, &tpd->tree_id, pe->path, worktree, repo);
1813 		if (err) {
1814 			free(tpd);
1815 			goto done;
1816 		}
1817 
1818 		if (tpd->entry_type == GOT_OBJ_TYPE_BLOB) {
1819 			err = got_path_basename(&tpd->entry_name, pe->path);
1820 			if (err) {
1821 				free(tpd->relpath);
1822 				free(tpd->tree_id);
1823 				free(tpd);
1824 				goto done;
1825 			}
1826 		} else
1827 			tpd->entry_name = NULL;
1828 
1829 		SIMPLEQ_INSERT_TAIL(&tree_paths, tpd, entry);
1830 	}
1831 
1832 	/*
1833 	 * Read the file index.
1834 	 * Checking out files is supposed to be an idempotent operation.
1835 	 * If the on-disk file index is incomplete we will try to complete it.
1836 	 */
1837 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1838 	if (err)
1839 		goto done;
1840 
1841 	tpd = SIMPLEQ_FIRST(&tree_paths);
1842 	TAILQ_FOREACH(pe, paths, entry) {
1843 		struct bump_base_commit_id_arg bbc_arg;
1844 
1845 		err = checkout_files(worktree, fileindex, tpd->relpath,
1846 		    tpd->tree_id, tpd->entry_name, repo,
1847 		    progress_cb, progress_arg, cancel_cb, cancel_arg);
1848 		if (err)
1849 			break;
1850 
1851 		bbc_arg.base_commit_id = worktree->base_commit_id;
1852 		bbc_arg.entry_name = tpd->entry_name;
1853 		bbc_arg.path = pe->path;
1854 		bbc_arg.path_len = strlen(pe->path);
1855 		bbc_arg.progress_cb = progress_cb;
1856 		bbc_arg.progress_arg = progress_arg;
1857 		err = got_fileindex_for_each_entry_safe(fileindex,
1858 		    bump_base_commit_id, &bbc_arg);
1859 		if (err)
1860 			break;
1861 
1862 		tpd = SIMPLEQ_NEXT(tpd, entry);
1863 	}
1864 	sync_err = sync_fileindex(fileindex, fileindex_path);
1865 	if (sync_err && err == NULL)
1866 		err = sync_err;
1867 done:
1868 	free(fileindex_path);
1869 	if (tree)
1870 		got_object_tree_close(tree);
1871 	if (commit)
1872 		got_object_commit_close(commit);
1873 	if (fileindex)
1874 		got_fileindex_free(fileindex);
1875 	while (!SIMPLEQ_EMPTY(&tree_paths)) {
1876 		tpd = SIMPLEQ_FIRST(&tree_paths);
1877 		SIMPLEQ_REMOVE_HEAD(&tree_paths, entry);
1878 		free(tpd->relpath);
1879 		free(tpd->tree_id);
1880 		free(tpd);
1881 	}
1882 	unlockerr = lock_worktree(worktree, LOCK_SH);
1883 	if (unlockerr && err == NULL)
1884 		err = unlockerr;
1885 	return err;
1886 }
1887 
1888 struct merge_file_cb_arg {
1889     struct got_worktree *worktree;
1890     struct got_fileindex *fileindex;
1891     got_worktree_checkout_cb progress_cb;
1892     void *progress_arg;
1893     got_worktree_cancel_cb cancel_cb;
1894     void *cancel_arg;
1895     struct got_object_id *commit_id2;
1896 };
1897 
1898 static const struct got_error *
1899 merge_file_cb(void *arg, struct got_blob_object *blob1,
1900     struct got_blob_object *blob2, struct got_object_id *id1,
1901     struct got_object_id *id2, const char *path1, const char *path2,
1902     struct got_repository *repo)
1903 {
1904 	static const struct got_error *err = NULL;
1905 	struct merge_file_cb_arg *a = arg;
1906 	struct got_fileindex_entry *ie;
1907 	char *ondisk_path = NULL;
1908 	struct stat sb;
1909 	unsigned char status;
1910 	int local_changes_subsumed;
1911 
1912 	if (blob1 && blob2) {
1913 		ie = got_fileindex_entry_get(a->fileindex, path2);
1914 		if (ie == NULL)
1915 			return (*a->progress_cb)(a->progress_arg,
1916 			    GOT_STATUS_MISSING, path2);
1917 
1918 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1919 		    path2) == -1)
1920 			return got_error_from_errno("asprintf");
1921 
1922 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1923 		if (err)
1924 			goto done;
1925 
1926 		if (status == GOT_STATUS_DELETE) {
1927 			err = (*a->progress_cb)(a->progress_arg,
1928 			    GOT_STATUS_MERGE, path2);
1929 			goto done;
1930 		}
1931 		if (status != GOT_STATUS_NO_CHANGE &&
1932 		    status != GOT_STATUS_MODIFY &&
1933 		    status != GOT_STATUS_CONFLICT &&
1934 		    status != GOT_STATUS_ADD) {
1935 			err = (*a->progress_cb)(a->progress_arg, status, path2);
1936 			goto done;
1937 		}
1938 
1939 		err = merge_blob(&local_changes_subsumed, a->worktree, blob1,
1940 		    ondisk_path, path2, sb.st_mode, blob2, a->commit_id2, repo,
1941 		    a->progress_cb, a->progress_arg);
1942 	} else if (blob1) {
1943 		ie = got_fileindex_entry_get(a->fileindex, path1);
1944 		if (ie == NULL)
1945 			return (*a->progress_cb)(a->progress_arg,
1946 			    GOT_STATUS_MISSING, path2);
1947 
1948 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1949 		    path1) == -1)
1950 			return got_error_from_errno("asprintf");
1951 
1952 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1953 		if (err)
1954 			goto done;
1955 
1956 		switch (status) {
1957 		case GOT_STATUS_NO_CHANGE:
1958 			err = (*a->progress_cb)(a->progress_arg,
1959 			    GOT_STATUS_DELETE, path1);
1960 			if (err)
1961 				goto done;
1962 			err = remove_ondisk_file(a->worktree->root_path, path1);
1963 			if (err)
1964 				goto done;
1965 			if (ie)
1966 				got_fileindex_entry_mark_deleted_from_disk(ie);
1967 			break;
1968 		case GOT_STATUS_DELETE:
1969 		case GOT_STATUS_MISSING:
1970 			err = (*a->progress_cb)(a->progress_arg,
1971 			    GOT_STATUS_DELETE, path1);
1972 			if (err)
1973 				goto done;
1974 			if (ie)
1975 				got_fileindex_entry_mark_deleted_from_disk(ie);
1976 			break;
1977 		case GOT_STATUS_ADD:
1978 		case GOT_STATUS_MODIFY:
1979 		case GOT_STATUS_CONFLICT:
1980 			err = (*a->progress_cb)(a->progress_arg,
1981 			    GOT_STATUS_CANNOT_DELETE, path1);
1982 			if (err)
1983 				goto done;
1984 			break;
1985 		case GOT_STATUS_OBSTRUCTED:
1986 			err = (*a->progress_cb)(a->progress_arg, status, path1);
1987 			if (err)
1988 				goto done;
1989 			break;
1990 		default:
1991 			break;
1992 		}
1993 	} else if (blob2) {
1994 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1995 		    path2) == -1)
1996 			return got_error_from_errno("asprintf");
1997 		ie = got_fileindex_entry_get(a->fileindex, path2);
1998 		if (ie) {
1999 			err = get_file_status(&status, &sb, ie, ondisk_path,
2000 			    repo);
2001 			if (err)
2002 				goto done;
2003 			if (status != GOT_STATUS_NO_CHANGE &&
2004 			    status != GOT_STATUS_MODIFY &&
2005 			    status != GOT_STATUS_CONFLICT &&
2006 			    status != GOT_STATUS_ADD) {
2007 				err = (*a->progress_cb)(a->progress_arg,
2008 				    status, path2);
2009 				goto done;
2010 			}
2011 			err = merge_blob(&local_changes_subsumed, a->worktree,
2012 			    NULL, ondisk_path, path2, sb.st_mode, blob2,
2013 			    a->commit_id2, repo,
2014 			    a->progress_cb, a->progress_arg);
2015 			if (status == GOT_STATUS_DELETE) {
2016 				err = update_blob_fileindex_entry(a->worktree,
2017 				    a->fileindex, ie, ondisk_path, ie->path,
2018 				    blob2, 0);
2019 				if (err)
2020 					goto done;
2021 			}
2022 		} else {
2023 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
2024 			err = install_blob(a->worktree, ondisk_path, path2,
2025 			    /* XXX get this from parent tree! */
2026 			    GOT_DEFAULT_FILE_MODE,
2027 			    sb.st_mode, blob2, 0, 0, repo,
2028 			    a->progress_cb, a->progress_arg);
2029 			if (err)
2030 				goto done;
2031 			err = got_fileindex_entry_alloc(&ie,
2032 			    ondisk_path, path2, NULL, NULL);
2033 			if (err)
2034 				goto done;
2035 			err = got_fileindex_entry_add(a->fileindex, ie);
2036 			if (err) {
2037 				got_fileindex_entry_free(ie);
2038 				goto done;
2039 			}
2040 		}
2041 	}
2042 done:
2043 	free(ondisk_path);
2044 	return err;
2045 }
2046 
2047 struct check_merge_ok_arg {
2048 	struct got_worktree *worktree;
2049 	struct got_repository *repo;
2050 };
2051 
2052 static const struct got_error *
2053 check_merge_ok(void *arg, struct got_fileindex_entry *ie)
2054 {
2055 	const struct got_error *err = NULL;
2056 	struct check_merge_ok_arg *a = arg;
2057 	unsigned char status;
2058 	struct stat sb;
2059 	char *ondisk_path;
2060 
2061 	/* Reject merges into a work tree with mixed base commits. */
2062 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
2063 	    SHA1_DIGEST_LENGTH))
2064 		return got_error(GOT_ERR_MIXED_COMMITS);
2065 
2066 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
2067 	    == -1)
2068 		return got_error_from_errno("asprintf");
2069 
2070 	/* Reject merges into a work tree with conflicted files. */
2071 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
2072 	if (err)
2073 		return err;
2074 	if (status == GOT_STATUS_CONFLICT)
2075 		return got_error(GOT_ERR_CONFLICTS);
2076 
2077 	return NULL;
2078 }
2079 
2080 static const struct got_error *
2081 merge_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
2082     const char *fileindex_path, struct got_object_id *commit_id1,
2083     struct got_object_id *commit_id2, struct got_repository *repo,
2084     got_worktree_checkout_cb progress_cb, void *progress_arg,
2085     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2086 {
2087 	const struct got_error *err = NULL, *sync_err;
2088 	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
2089 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
2090 	struct merge_file_cb_arg arg;
2091 
2092 	if (commit_id1) {
2093 		err = got_object_id_by_path(&tree_id1, repo, commit_id1,
2094 		    worktree->path_prefix);
2095 		if (err)
2096 			goto done;
2097 
2098 		err = got_object_open_as_tree(&tree1, repo, tree_id1);
2099 		if (err)
2100 			goto done;
2101 	}
2102 
2103 	err = got_object_id_by_path(&tree_id2, repo, commit_id2,
2104 	    worktree->path_prefix);
2105 	if (err)
2106 		goto done;
2107 
2108 	err = got_object_open_as_tree(&tree2, repo, tree_id2);
2109 	if (err)
2110 		goto done;
2111 
2112 	arg.worktree = worktree;
2113 	arg.fileindex = fileindex;
2114 	arg.progress_cb = progress_cb;
2115 	arg.progress_arg = progress_arg;
2116 	arg.cancel_cb = cancel_cb;
2117 	arg.cancel_arg = cancel_arg;
2118 	arg.commit_id2 = commit_id2;
2119 	err = got_diff_tree(tree1, tree2, "", "", repo, merge_file_cb, &arg);
2120 	sync_err = sync_fileindex(fileindex, fileindex_path);
2121 	if (sync_err && err == NULL)
2122 		err = sync_err;
2123 done:
2124 	if (tree1)
2125 		got_object_tree_close(tree1);
2126 	if (tree2)
2127 		got_object_tree_close(tree2);
2128 	return err;
2129 }
2130 
2131 const struct got_error *
2132 got_worktree_merge_files(struct got_worktree *worktree,
2133     struct got_object_id *commit_id1, struct got_object_id *commit_id2,
2134     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
2135     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2136 {
2137 	const struct got_error *err, *unlockerr;
2138 	char *fileindex_path = NULL;
2139 	struct got_fileindex *fileindex = NULL;
2140 	struct check_merge_ok_arg mok_arg;
2141 
2142 	err = lock_worktree(worktree, LOCK_EX);
2143 	if (err)
2144 		return err;
2145 
2146 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2147 	if (err)
2148 		goto done;
2149 
2150 	mok_arg.worktree = worktree;
2151 	mok_arg.repo = repo;
2152 	err = got_fileindex_for_each_entry_safe(fileindex, check_merge_ok,
2153 	    &mok_arg);
2154 	if (err)
2155 		goto done;
2156 
2157 	err = merge_files(worktree, fileindex, fileindex_path, commit_id1,
2158 	    commit_id2, repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
2159 done:
2160 	if (fileindex)
2161 		got_fileindex_free(fileindex);
2162 	free(fileindex_path);
2163 	unlockerr = lock_worktree(worktree, LOCK_SH);
2164 	if (unlockerr && err == NULL)
2165 		err = unlockerr;
2166 	return err;
2167 }
2168 
2169 struct diff_dir_cb_arg {
2170     struct got_fileindex *fileindex;
2171     struct got_worktree *worktree;
2172     const char *status_path;
2173     size_t status_path_len;
2174     struct got_repository *repo;
2175     got_worktree_status_cb status_cb;
2176     void *status_arg;
2177     got_worktree_cancel_cb cancel_cb;
2178     void *cancel_arg;
2179 };
2180 
2181 static const struct got_error *
2182 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
2183     got_worktree_status_cb status_cb, void *status_arg,
2184     struct got_repository *repo)
2185 {
2186 	const struct got_error *err = NULL;
2187 	unsigned char status = GOT_STATUS_NO_CHANGE;
2188 	struct stat sb;
2189 	struct got_object_id blob_id, commit_id;
2190 
2191 	err = get_file_status(&status, &sb, ie, abspath, repo);
2192 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
2193 		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2194 		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2195 		err = (*status_cb)(status_arg, status, ie->path, &blob_id,
2196 		    &commit_id);
2197 	}
2198 	return err;
2199 }
2200 
2201 static const struct got_error *
2202 status_old_new(void *arg, struct got_fileindex_entry *ie,
2203     struct dirent *de, const char *parent_path)
2204 {
2205 	const struct got_error *err = NULL;
2206 	struct diff_dir_cb_arg *a = arg;
2207 	char *abspath;
2208 
2209 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2210 		return got_error(GOT_ERR_CANCELLED);
2211 
2212 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
2213 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
2214 		return NULL;
2215 
2216 	if (parent_path[0]) {
2217 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
2218 		    parent_path, de->d_name) == -1)
2219 			return got_error_from_errno("asprintf");
2220 	} else {
2221 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
2222 		    de->d_name) == -1)
2223 			return got_error_from_errno("asprintf");
2224 	}
2225 
2226 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
2227 	    a->repo);
2228 	free(abspath);
2229 	return err;
2230 }
2231 
2232 static const struct got_error *
2233 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
2234 {
2235 	struct diff_dir_cb_arg *a = arg;
2236 	struct got_object_id blob_id, commit_id;
2237 	unsigned char status;
2238 
2239 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2240 		return got_error(GOT_ERR_CANCELLED);
2241 
2242 	if (!got_path_is_child(ie->path, a->status_path, a->status_path_len))
2243 		return NULL;
2244 
2245 	memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2246 	memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2247 	if (got_fileindex_entry_has_file_on_disk(ie))
2248 		status = GOT_STATUS_MISSING;
2249 	else
2250 		status = GOT_STATUS_DELETE;
2251 	return (*a->status_cb)(a->status_arg, status, ie->path, &blob_id,
2252 	    &commit_id);
2253 }
2254 
2255 static const struct got_error *
2256 status_new(void *arg, struct dirent *de, const char *parent_path)
2257 {
2258 	const struct got_error *err = NULL;
2259 	struct diff_dir_cb_arg *a = arg;
2260 	char *path = NULL;
2261 
2262 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2263 		return got_error(GOT_ERR_CANCELLED);
2264 
2265 	if (de->d_type == DT_DIR)
2266 		return NULL;
2267 
2268 	/* XXX ignore symlinks for now */
2269 	if (de->d_type == DT_LNK)
2270 		return NULL;
2271 
2272 	if (parent_path[0]) {
2273 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
2274 			return got_error_from_errno("asprintf");
2275 	} else {
2276 		path = de->d_name;
2277 	}
2278 
2279 	if (got_path_is_child(path, a->status_path, a->status_path_len))
2280 		err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED,
2281 		    path, NULL, NULL);
2282 	if (parent_path[0])
2283 		free(path);
2284 	return err;
2285 }
2286 
2287 static const struct got_error *
2288 worktree_status(struct got_worktree *worktree, const char *path,
2289     struct got_fileindex *fileindex, struct got_repository *repo,
2290     got_worktree_status_cb status_cb, void *status_arg,
2291     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2292 {
2293 	const struct got_error *err = NULL;
2294 	DIR *workdir = NULL;
2295 	struct got_fileindex_diff_dir_cb fdiff_cb;
2296 	struct diff_dir_cb_arg arg;
2297 	char *ondisk_path = NULL;
2298 
2299 	if (asprintf(&ondisk_path, "%s%s%s",
2300 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
2301 		err = got_error_from_errno("asprintf");
2302 		goto done;
2303 	}
2304 	workdir = opendir(ondisk_path);
2305 	if (workdir == NULL) {
2306 		if (errno == ENOTDIR || errno == ENOENT) {
2307 			err = report_file_status(
2308 			    got_fileindex_entry_get(fileindex, path),
2309 			    ondisk_path, status_cb, status_arg, repo);
2310 			goto done;
2311 		} else {
2312 			err = got_error_from_errno2("opendir", ondisk_path);
2313 			goto done;
2314 		}
2315 	}
2316 	fdiff_cb.diff_old_new = status_old_new;
2317 	fdiff_cb.diff_old = status_old;
2318 	fdiff_cb.diff_new = status_new;
2319 	arg.fileindex = fileindex;
2320 	arg.worktree = worktree;
2321 	arg.status_path = path;
2322 	arg.status_path_len = strlen(path);
2323 	arg.repo = repo;
2324 	arg.status_cb = status_cb;
2325 	arg.status_arg = status_arg;
2326 	arg.cancel_cb = cancel_cb;
2327 	arg.cancel_arg = cancel_arg;
2328 	err = got_fileindex_diff_dir(fileindex, workdir, worktree->root_path,
2329 	    path, repo, &fdiff_cb, &arg);
2330 done:
2331 	if (workdir)
2332 		closedir(workdir);
2333 	free(ondisk_path);
2334 	return err;
2335 }
2336 
2337 const struct got_error *
2338 got_worktree_status(struct got_worktree *worktree,
2339     struct got_pathlist_head *paths, struct got_repository *repo,
2340     got_worktree_status_cb status_cb, void *status_arg,
2341     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2342 {
2343 	const struct got_error *err = NULL;
2344 	char *fileindex_path = NULL;
2345 	struct got_fileindex *fileindex = NULL;
2346 	struct got_pathlist_entry *pe;
2347 
2348 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2349 	if (err)
2350 		return err;
2351 
2352 	TAILQ_FOREACH(pe, paths, entry) {
2353 		err = worktree_status(worktree, pe->path, fileindex, repo,
2354 			status_cb, status_arg, cancel_cb, cancel_arg);
2355 		if (err)
2356 			break;
2357 	}
2358 	free(fileindex_path);
2359 	got_fileindex_free(fileindex);
2360 	return err;
2361 }
2362 
2363 const struct got_error *
2364 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
2365     const char *arg)
2366 {
2367 	const struct got_error *err = NULL;
2368 	char *resolved, *cwd = NULL, *path = NULL;
2369 	size_t len;
2370 
2371 	*wt_path = NULL;
2372 
2373 	resolved = realpath(arg, NULL);
2374 	if (resolved == NULL) {
2375 		if (errno != ENOENT)
2376 			return got_error_from_errno2("realpath", arg);
2377 		cwd = getcwd(NULL, 0);
2378 		if (cwd == NULL)
2379 			return got_error_from_errno("getcwd");
2380 		if (asprintf(&resolved, "%s/%s", cwd, arg) == -1) {
2381 			err = got_error_from_errno("asprintf");
2382 			goto done;
2383 		}
2384 	}
2385 
2386 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
2387 	    strlen(got_worktree_get_root_path(worktree)))) {
2388 		err = got_error(GOT_ERR_BAD_PATH);
2389 		goto done;
2390 	}
2391 
2392 	if (strlen(resolved) > strlen(got_worktree_get_root_path(worktree))) {
2393 		err = got_path_skip_common_ancestor(&path,
2394 		    got_worktree_get_root_path(worktree), resolved);
2395 		if (err)
2396 			goto done;
2397 	} else {
2398 		path = strdup("");
2399 		if (path == NULL) {
2400 			err = got_error_from_errno("strdup");
2401 			goto done;
2402 		}
2403 	}
2404 
2405 	/* XXX status walk can't deal with trailing slash! */
2406 	len = strlen(path);
2407 	while (len > 0 && path[len - 1] == '/') {
2408 		path[len - 1] = '\0';
2409 		len--;
2410 	}
2411 done:
2412 	free(resolved);
2413 	free(cwd);
2414 	if (err == NULL)
2415 		*wt_path = path;
2416 	else
2417 		free(path);
2418 	return err;
2419 }
2420 
2421 static const struct got_error *
2422 schedule_addition(const char *ondisk_path, struct got_fileindex *fileindex,
2423     const char *relpath, got_worktree_status_cb status_cb, void *status_arg,
2424     struct got_repository *repo)
2425 {
2426 	const struct got_error *err = NULL;
2427 	struct got_fileindex_entry *ie;
2428 
2429 	/* Re-adding an existing entry is a no-op. */
2430 	if (got_fileindex_entry_get(fileindex, relpath) != NULL)
2431 		return NULL;
2432 
2433 	err = got_fileindex_entry_alloc(&ie, ondisk_path, relpath, NULL, NULL);
2434 	if (err)
2435 		return err;
2436 
2437 	err = got_fileindex_entry_add(fileindex, ie);
2438 	if (err) {
2439 		got_fileindex_entry_free(ie);
2440 		return err;
2441 	}
2442 
2443 	return report_file_status(ie, relpath, status_cb, status_arg, repo);
2444 }
2445 
2446 const struct got_error *
2447 got_worktree_schedule_add(struct got_worktree *worktree,
2448     struct got_pathlist_head *ondisk_paths,
2449     got_worktree_status_cb status_cb, void *status_arg,
2450     struct got_repository *repo)
2451 {
2452 	struct got_fileindex *fileindex = NULL;
2453 	char *fileindex_path = NULL;
2454 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2455 	struct got_pathlist_entry *pe;
2456 
2457 	err = lock_worktree(worktree, LOCK_EX);
2458 	if (err)
2459 		return err;
2460 
2461 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2462 	if (err)
2463 		goto done;
2464 
2465 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2466 		char *relpath;
2467 		err = got_path_skip_common_ancestor(&relpath,
2468 		    got_worktree_get_root_path(worktree), pe->path);
2469 		if (err)
2470 			break;
2471 		err = schedule_addition(pe->path, fileindex, relpath,
2472 		    status_cb, status_arg, repo);
2473 		free(relpath);
2474 		if (err)
2475 			break;
2476 	}
2477 	sync_err = sync_fileindex(fileindex, fileindex_path);
2478 	if (sync_err && err == NULL)
2479 		err = sync_err;
2480 done:
2481 	free(fileindex_path);
2482 	if (fileindex)
2483 		got_fileindex_free(fileindex);
2484 	unlockerr = lock_worktree(worktree, LOCK_SH);
2485 	if (unlockerr && err == NULL)
2486 		err = unlockerr;
2487 	return err;
2488 }
2489 
2490 static const struct got_error *
2491 schedule_for_deletion(const char *ondisk_path, struct got_fileindex *fileindex,
2492     const char *relpath, int delete_local_mods,
2493     got_worktree_status_cb status_cb, void *status_arg,
2494     struct got_repository *repo)
2495 {
2496 	const struct got_error *err = NULL;
2497 	struct got_fileindex_entry *ie = NULL;
2498 	unsigned char status;
2499 	struct stat sb;
2500 
2501 	ie = got_fileindex_entry_get(fileindex, relpath);
2502 	if (ie == NULL)
2503 		return got_error(GOT_ERR_BAD_PATH);
2504 
2505 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2506 	if (err)
2507 		return err;
2508 
2509 	if (status != GOT_STATUS_NO_CHANGE) {
2510 		if (status == GOT_STATUS_DELETE)
2511 			return got_error_set_errno(ENOENT, ondisk_path);
2512 		if (status != GOT_STATUS_MODIFY)
2513 			return got_error(GOT_ERR_FILE_STATUS);
2514 		if (!delete_local_mods)
2515 			return got_error(GOT_ERR_FILE_MODIFIED);
2516 	}
2517 
2518 	if (unlink(ondisk_path) != 0)
2519 		return got_error_from_errno2("unlink", ondisk_path);
2520 
2521 	got_fileindex_entry_mark_deleted_from_disk(ie);
2522 	return report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2523 }
2524 
2525 const struct got_error *
2526 got_worktree_schedule_delete(struct got_worktree *worktree,
2527     struct got_pathlist_head *ondisk_paths, int delete_local_mods,
2528     got_worktree_status_cb status_cb, void *status_arg,
2529     struct got_repository *repo)
2530 {
2531 	struct got_fileindex *fileindex = NULL;
2532 	char *fileindex_path = NULL;
2533 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2534 	struct got_pathlist_entry *pe;
2535 
2536 	err = lock_worktree(worktree, LOCK_EX);
2537 	if (err)
2538 		return err;
2539 
2540 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2541 	if (err)
2542 		goto done;
2543 
2544 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2545 		char *relpath;
2546 		err = got_path_skip_common_ancestor(&relpath,
2547 		    got_worktree_get_root_path(worktree), pe->path);
2548 		if (err)
2549 			break;
2550 		err = schedule_for_deletion(pe->path, fileindex, relpath,
2551 		    delete_local_mods, status_cb, status_arg, repo);
2552 		free(relpath);
2553 		if (err)
2554 			break;
2555 	}
2556 	sync_err = sync_fileindex(fileindex, fileindex_path);
2557 	if (sync_err && err == NULL)
2558 		err = sync_err;
2559 done:
2560 	free(fileindex_path);
2561 	if (fileindex)
2562 		got_fileindex_free(fileindex);
2563 	unlockerr = lock_worktree(worktree, LOCK_SH);
2564 	if (unlockerr && err == NULL)
2565 		err = unlockerr;
2566 	return err;
2567 }
2568 
2569 static const struct got_error *
2570 revert_file(struct got_worktree *worktree, struct got_fileindex *fileindex,
2571     const char *ondisk_path,
2572     got_worktree_checkout_cb progress_cb, void *progress_arg,
2573     struct got_repository *repo)
2574 {
2575 	const struct got_error *err = NULL;
2576 	char *relpath = NULL, *parent_path = NULL;
2577 	struct got_fileindex_entry *ie;
2578 	struct got_tree_object *tree = NULL;
2579 	struct got_object_id *tree_id = NULL;
2580 	const struct got_tree_entry *te;
2581 	char *tree_path = NULL, *te_name;
2582 	struct got_blob_object *blob = NULL;
2583 	unsigned char status;
2584 	struct stat sb;
2585 
2586 	err = got_path_skip_common_ancestor(&relpath,
2587 	    got_worktree_get_root_path(worktree), ondisk_path);
2588 	if (err)
2589 		goto done;
2590 
2591 	ie = got_fileindex_entry_get(fileindex, relpath);
2592 	if (ie == NULL) {
2593 		err = got_error(GOT_ERR_BAD_PATH);
2594 		goto done;
2595 	}
2596 
2597 	/* Construct in-repository path of tree which contains this blob. */
2598 	err = got_path_dirname(&parent_path, ie->path);
2599 	if (err) {
2600 		if (err->code != GOT_ERR_BAD_PATH)
2601 			goto done;
2602 		parent_path = strdup("/");
2603 		if (parent_path == NULL) {
2604 			err = got_error_from_errno("strdup");
2605 			goto done;
2606 		}
2607 	}
2608 	if (got_path_is_root_dir(worktree->path_prefix)) {
2609 		tree_path = strdup(parent_path);
2610 		if (tree_path == NULL) {
2611 			err = got_error_from_errno("strdup");
2612 			goto done;
2613 		}
2614 	} else {
2615 		if (got_path_is_root_dir(parent_path)) {
2616 			tree_path = strdup(worktree->path_prefix);
2617 			if (tree_path == NULL) {
2618 				err = got_error_from_errno("strdup");
2619 				goto done;
2620 			}
2621 		} else {
2622 			if (asprintf(&tree_path, "%s/%s",
2623 			    worktree->path_prefix, parent_path) == -1) {
2624 				err = got_error_from_errno("asprintf");
2625 				goto done;
2626 			}
2627 		}
2628 	}
2629 
2630 	err = got_object_id_by_path(&tree_id, repo, worktree->base_commit_id,
2631 	    tree_path);
2632 	if (err)
2633 		goto done;
2634 
2635 	err = got_object_open_as_tree(&tree, repo, tree_id);
2636 	if (err)
2637 		goto done;
2638 
2639 	te_name = basename(ie->path);
2640 	if (te_name == NULL) {
2641 		err = got_error_from_errno2("basename", ie->path);
2642 		goto done;
2643 	}
2644 
2645 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2646 	if (err)
2647 		goto done;
2648 
2649 	te = got_object_tree_find_entry(tree, te_name);
2650 	if (te == NULL && status != GOT_STATUS_ADD) {
2651 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
2652 		goto done;
2653 	}
2654 
2655 	switch (status) {
2656 	case GOT_STATUS_ADD:
2657 		err = (*progress_cb)(progress_arg, GOT_STATUS_REVERT, ie->path);
2658 		if (err)
2659 			goto done;
2660 		got_fileindex_entry_remove(fileindex, ie);
2661 		break;
2662 	case GOT_STATUS_DELETE:
2663 	case GOT_STATUS_MODIFY:
2664 	case GOT_STATUS_CONFLICT:
2665 	case GOT_STATUS_MISSING: {
2666 		struct got_object_id id;
2667 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2668 		err = got_object_open_as_blob(&blob, repo, &id, 8192);
2669 		if (err)
2670 			goto done;
2671 		err = install_blob(worktree, ondisk_path, ie->path,
2672 		    te->mode, sb.st_mode, blob, 0, 1, repo, progress_cb,
2673 		    progress_arg);
2674 		if (err)
2675 			goto done;
2676 		if (status == GOT_STATUS_DELETE) {
2677 			err = update_blob_fileindex_entry(worktree,
2678 			    fileindex, ie, ondisk_path, ie->path, blob, 1);
2679 			if (err)
2680 				goto done;
2681 		}
2682 		break;
2683 	}
2684 	default:
2685 			goto done;
2686 	}
2687 done:
2688 	free(relpath);
2689 	free(parent_path);
2690 	free(tree_path);
2691 	if (blob)
2692 		got_object_blob_close(blob);
2693 	if (tree)
2694 		got_object_tree_close(tree);
2695 	free(tree_id);
2696 	return err;
2697 }
2698 
2699 const struct got_error *
2700 got_worktree_revert(struct got_worktree *worktree,
2701     struct got_pathlist_head *ondisk_paths,
2702     got_worktree_checkout_cb progress_cb, void *progress_arg,
2703     struct got_repository *repo)
2704 {
2705 	struct got_fileindex *fileindex = NULL;
2706 	char *fileindex_path = NULL;
2707 	const struct got_error *err = NULL, *unlockerr = NULL;
2708 	const struct got_error *sync_err = NULL;
2709 	struct got_pathlist_entry *pe;
2710 
2711 	err = lock_worktree(worktree, LOCK_EX);
2712 	if (err)
2713 		return err;
2714 
2715 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2716 	if (err)
2717 		goto done;
2718 
2719 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2720 		err = revert_file(worktree, fileindex, pe->path,
2721 		    progress_cb, progress_arg, repo);
2722 		if (err)
2723 			break;
2724 	}
2725 	sync_err = sync_fileindex(fileindex, fileindex_path);
2726 	if (sync_err && err == NULL)
2727 		err = sync_err;
2728 done:
2729 	free(fileindex_path);
2730 	if (fileindex)
2731 		got_fileindex_free(fileindex);
2732 	unlockerr = lock_worktree(worktree, LOCK_SH);
2733 	if (unlockerr && err == NULL)
2734 		err = unlockerr;
2735 	return err;
2736 }
2737 
2738 static void
2739 free_commitable(struct got_commitable *ct)
2740 {
2741 	free(ct->path);
2742 	free(ct->in_repo_path);
2743 	free(ct->ondisk_path);
2744 	free(ct->blob_id);
2745 	free(ct->base_blob_id);
2746 	free(ct->base_commit_id);
2747 	free(ct);
2748 }
2749 
2750 struct collect_commitables_arg {
2751 	struct got_pathlist_head *commitable_paths;
2752 	struct got_repository *repo;
2753 	struct got_worktree *worktree;
2754 };
2755 
2756 static const struct got_error *
2757 collect_commitables(void *arg, unsigned char status, const char *relpath,
2758     struct got_object_id *blob_id, struct got_object_id *commit_id)
2759 {
2760 	struct collect_commitables_arg *a = arg;
2761 	const struct got_error *err = NULL;
2762 	struct got_commitable *ct = NULL;
2763 	struct got_pathlist_entry *new = NULL;
2764 	char *parent_path = NULL, *path = NULL;
2765 	struct stat sb;
2766 
2767 	if (status == GOT_STATUS_CONFLICT)
2768 		return got_error(GOT_ERR_COMMIT_CONFLICT);
2769 
2770 	if (status != GOT_STATUS_MODIFY && status != GOT_STATUS_ADD &&
2771 	    status != GOT_STATUS_DELETE)
2772 		return NULL;
2773 
2774 	if (asprintf(&path, "/%s", relpath) == -1) {
2775 		err = got_error_from_errno("asprintf");
2776 		goto done;
2777 	}
2778 	if (strcmp(path, "/") == 0) {
2779 		parent_path = strdup("");
2780 		if (parent_path == NULL)
2781 			return got_error_from_errno("strdup");
2782 	} else {
2783 		err = got_path_dirname(&parent_path, path);
2784 		if (err)
2785 			return err;
2786 	}
2787 
2788 	ct = calloc(1, sizeof(*ct));
2789 	if (ct == NULL) {
2790 		err = got_error_from_errno("calloc");
2791 		goto done;
2792 	}
2793 
2794 	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
2795 	    relpath) == -1) {
2796 		err = got_error_from_errno("asprintf");
2797 		goto done;
2798 	}
2799 	if (status == GOT_STATUS_DELETE) {
2800 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
2801 	} else {
2802 		if (lstat(ct->ondisk_path, &sb) != 0) {
2803 			err = got_error_from_errno2("lstat", ct->ondisk_path);
2804 			goto done;
2805 		}
2806 		ct->mode = sb.st_mode;
2807 	}
2808 
2809 	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
2810 	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
2811 	    relpath) == -1) {
2812 		err = got_error_from_errno("asprintf");
2813 		goto done;
2814 	}
2815 
2816 	ct->status = status;
2817 	ct->blob_id = NULL; /* will be filled in when blob gets created */
2818 	if (ct->status != GOT_STATUS_ADD) {
2819 		ct->base_blob_id = got_object_id_dup(blob_id);
2820 		if (ct->base_blob_id == NULL) {
2821 			err = got_error_from_errno("got_object_id_dup");
2822 			goto done;
2823 		}
2824 		ct->base_commit_id = got_object_id_dup(commit_id);
2825 		if (ct->base_commit_id == NULL) {
2826 			err = got_error_from_errno("got_object_id_dup");
2827 			goto done;
2828 		}
2829 	}
2830 	ct->path = strdup(path);
2831 	if (ct->path == NULL) {
2832 		err = got_error_from_errno("strdup");
2833 		goto done;
2834 	}
2835 	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
2836 done:
2837 	if (ct && (err || new == NULL))
2838 		free_commitable(ct);
2839 	free(parent_path);
2840 	free(path);
2841 	return err;
2842 }
2843 
2844 static const struct got_error *write_tree(struct got_object_id **,
2845     struct got_tree_object *, const char *, struct got_pathlist_head *,
2846     got_worktree_status_cb status_cb, void *status_arg,
2847     struct got_repository *);
2848 
2849 static const struct got_error *
2850 write_subtree(struct got_object_id **new_subtree_id,
2851     struct got_tree_entry *te, const char *parent_path,
2852     struct got_pathlist_head *commitable_paths,
2853     got_worktree_status_cb status_cb, void *status_arg,
2854     struct got_repository *repo)
2855 {
2856 	const struct got_error *err = NULL;
2857 	struct got_tree_object *subtree;
2858 	char *subpath;
2859 
2860 	if (asprintf(&subpath, "%s%s%s", parent_path,
2861 	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
2862 		return got_error_from_errno("asprintf");
2863 
2864 	err = got_object_open_as_tree(&subtree, repo, te->id);
2865 	if (err)
2866 		return err;
2867 
2868 	err = write_tree(new_subtree_id, subtree, subpath, commitable_paths,
2869 	    status_cb, status_arg, repo);
2870 	got_object_tree_close(subtree);
2871 	free(subpath);
2872 	return err;
2873 }
2874 
2875 static const struct got_error *
2876 match_ct_parent_path(int *match, struct got_commitable *ct, const char *path)
2877 {
2878 	const struct got_error *err = NULL;
2879 	char *ct_parent_path = NULL;
2880 
2881 	*match = 0;
2882 
2883 	if (strchr(ct->in_repo_path, '/') == NULL) {
2884 		*match = got_path_is_root_dir(path);
2885 		return NULL;
2886 	}
2887 
2888 	err = got_path_dirname(&ct_parent_path, ct->in_repo_path);
2889 	if (err)
2890 		return err;
2891 	*match = (strcmp(path, ct_parent_path) == 0);
2892 	free(ct_parent_path);
2893 	return err;
2894 }
2895 
2896 static mode_t
2897 get_ct_file_mode(struct got_commitable *ct)
2898 {
2899 	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
2900 }
2901 
2902 static const struct got_error *
2903 alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
2904     struct got_tree_entry *te, struct got_commitable *ct)
2905 {
2906 	const struct got_error *err = NULL;
2907 
2908 	*new_te = NULL;
2909 
2910 	err = got_object_tree_entry_dup(new_te, te);
2911 	if (err)
2912 		goto done;
2913 
2914 	(*new_te)->mode = get_ct_file_mode(ct);
2915 
2916 	free((*new_te)->id);
2917 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2918 	if ((*new_te)->id == NULL) {
2919 		err = got_error_from_errno("got_object_id_dup");
2920 		goto done;
2921 	}
2922 done:
2923 	if (err && *new_te) {
2924 		got_object_tree_entry_close(*new_te);
2925 		*new_te = NULL;
2926 	}
2927 	return err;
2928 }
2929 
2930 static const struct got_error *
2931 alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
2932     struct got_commitable *ct)
2933 {
2934 	const struct got_error *err = NULL;
2935 	char *ct_name;
2936 
2937 	 *new_te = NULL;
2938 
2939 	*new_te = calloc(1, sizeof(**new_te));
2940 	if (*new_te == NULL)
2941 		return got_error_from_errno("calloc");
2942 
2943 	ct_name = basename(ct->path);
2944 	if (ct_name == NULL) {
2945 		err = got_error_from_errno2("basename", ct->path);
2946 		goto done;
2947 	}
2948 	(*new_te)->name = strdup(ct_name);
2949 	if ((*new_te)->name == NULL) {
2950 		err = got_error_from_errno("strdup");
2951 		goto done;
2952 	}
2953 
2954 	(*new_te)->mode = get_ct_file_mode(ct);
2955 
2956 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2957 	if ((*new_te)->id == NULL) {
2958 		err = got_error_from_errno("got_object_id_dup");
2959 		goto done;
2960 	}
2961 done:
2962 	if (err && *new_te) {
2963 		got_object_tree_entry_close(*new_te);
2964 		*new_te = NULL;
2965 	}
2966 	return err;
2967 }
2968 
2969 static const struct got_error *
2970 insert_tree_entry(struct got_tree_entry *new_te,
2971     struct got_pathlist_head *paths)
2972 {
2973 	const struct got_error *err = NULL;
2974 	struct got_pathlist_entry *new_pe;
2975 
2976 	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
2977 	if (err)
2978 		return err;
2979 	if (new_pe == NULL)
2980 		return got_error(GOT_ERR_TREE_DUP_ENTRY);
2981 	return NULL;
2982 }
2983 
2984 static const struct got_error *
2985 report_ct_status(struct got_commitable *ct,
2986     got_worktree_status_cb status_cb, void *status_arg)
2987 {
2988 	const char *ct_path = ct->path;
2989 	while (ct_path[0] == '/')
2990 		ct_path++;
2991 	return (*status_cb)(status_arg, ct->status, ct_path, ct->blob_id, NULL);
2992 }
2993 
2994 static const struct got_error *
2995 match_modified_subtree(int *modified, struct got_tree_entry *te,
2996     const char *base_tree_path, struct got_pathlist_head *commitable_paths)
2997 {
2998 	const struct got_error *err = NULL;
2999 	struct got_pathlist_entry *pe;
3000 	char *te_path;
3001 
3002 	*modified = 0;
3003 
3004 	if (asprintf(&te_path, "%s%s%s", base_tree_path,
3005 	    got_path_is_root_dir(base_tree_path) ? "" : "/",
3006 	    te->name) == -1)
3007 		return got_error_from_errno("asprintf");
3008 
3009 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3010 		struct got_commitable *ct = pe->data;
3011 		*modified = got_path_is_child(ct->in_repo_path, te_path,
3012 		    strlen(te_path));
3013 		 if (*modified)
3014 			break;
3015 	}
3016 
3017 	free(te_path);
3018 	return err;
3019 }
3020 
3021 static const struct got_error *
3022 match_deleted_or_modified_ct(struct got_commitable **ctp,
3023     struct got_tree_entry *te, const char *base_tree_path,
3024     struct got_pathlist_head *commitable_paths)
3025 {
3026 	const struct got_error *err = NULL;
3027 	struct got_pathlist_entry *pe;
3028 
3029 	*ctp = NULL;
3030 
3031 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3032 		struct got_commitable *ct = pe->data;
3033 		char *ct_name = NULL;
3034 		int path_matches;
3035 
3036 		if (ct->status != GOT_STATUS_MODIFY &&
3037 		    ct->status != GOT_STATUS_DELETE)
3038 			continue;
3039 
3040 		if (got_object_id_cmp(ct->base_blob_id, te->id) != 0)
3041 			continue;
3042 
3043 		 err = match_ct_parent_path(&path_matches, ct, base_tree_path);
3044 		 if (err)
3045 			return err;
3046 		if (!path_matches)
3047 			continue;
3048 
3049 		ct_name = basename(pe->path);
3050 		if (ct_name == NULL)
3051 			return got_error_from_errno2("basename", pe->path);
3052 
3053 		if (strcmp(te->name, ct_name) != 0)
3054 			continue;
3055 
3056 		*ctp = ct;
3057 		break;
3058 	}
3059 
3060 	return err;
3061 }
3062 
3063 static const struct got_error *
3064 make_subtree_for_added_blob(struct got_tree_entry **new_tep,
3065     const char *child_path, const char *path_base_tree,
3066     struct got_pathlist_head *commitable_paths,
3067     got_worktree_status_cb status_cb, void *status_arg,
3068     struct got_repository *repo)
3069 {
3070 	const struct got_error *err = NULL;
3071 	struct got_tree_entry *new_te;
3072 	char *subtree_path;
3073 
3074 	*new_tep = NULL;
3075 
3076 	if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
3077 	    got_path_is_root_dir(path_base_tree) ? "" : "/",
3078 	    child_path) == -1)
3079 		return got_error_from_errno("asprintf");
3080 
3081 	new_te = calloc(1, sizeof(*new_te));
3082 	new_te->mode = S_IFDIR;
3083 	new_te->name = strdup(child_path);
3084 	if (new_te->name == NULL) {
3085 		err = got_error_from_errno("strdup");
3086 		got_object_tree_entry_close(new_te);
3087 		goto done;
3088 	}
3089 	err = write_tree(&new_te->id, NULL, subtree_path,
3090 	    commitable_paths, status_cb, status_arg, repo);
3091 	if (err) {
3092 		got_object_tree_entry_close(new_te);
3093 		goto done;
3094 	}
3095 done:
3096 	free(subtree_path);
3097 	if (err == NULL)
3098 		*new_tep = new_te;
3099 	return err;
3100 }
3101 
3102 static const struct got_error *
3103 write_tree(struct got_object_id **new_tree_id,
3104     struct got_tree_object *base_tree, const char *path_base_tree,
3105     struct got_pathlist_head *commitable_paths,
3106     got_worktree_status_cb status_cb, void *status_arg,
3107     struct got_repository *repo)
3108 {
3109 	const struct got_error *err = NULL;
3110 	const struct got_tree_entries *base_entries = NULL;
3111 	struct got_pathlist_head paths;
3112 	struct got_tree_entries new_tree_entries;
3113 	struct got_tree_entry *te, *new_te = NULL;
3114 	struct got_pathlist_entry *pe;
3115 
3116 	TAILQ_INIT(&paths);
3117 	new_tree_entries.nentries = 0;
3118 	SIMPLEQ_INIT(&new_tree_entries.head);
3119 
3120 	/* Insert, and recurse into, newly added entries first. */
3121 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3122 		struct got_commitable *ct = pe->data;
3123 		char *child_path = NULL, *slash;
3124 
3125 		if (ct->status != GOT_STATUS_ADD ||
3126 		    (ct->flags & GOT_COMMITABLE_ADDED))
3127 			continue;
3128 
3129 		 if (!got_path_is_child(pe->path, path_base_tree,
3130 		     strlen(path_base_tree)))
3131 			continue;
3132 
3133 		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
3134 		    pe->path);
3135 		if (err)
3136 			goto done;
3137 
3138 		slash = strchr(child_path, '/');
3139 		if (slash == NULL) {
3140 			err = alloc_added_blob_tree_entry(&new_te, ct);
3141 			if (err)
3142 				goto done;
3143 			err = report_ct_status(ct, status_cb, status_arg);
3144 			if (err)
3145 				goto done;
3146 			ct->flags |= GOT_COMMITABLE_ADDED;
3147 			err = insert_tree_entry(new_te, &paths);
3148 			if (err)
3149 				goto done;
3150 		} else {
3151 			*slash = '\0'; /* trim trailing path components */
3152 			if (base_tree == NULL ||
3153 			    got_object_tree_find_entry(base_tree, child_path)
3154 			    == NULL) {
3155 				err = make_subtree_for_added_blob(&new_te,
3156 				    child_path, path_base_tree,
3157 				    commitable_paths, status_cb, status_arg,
3158 				    repo);
3159 				if (err)
3160 					goto done;
3161 				err = insert_tree_entry(new_te, &paths);
3162 				if (err)
3163 					goto done;
3164 			}
3165 		}
3166 	}
3167 
3168 	if (base_tree) {
3169 		/* Handle modified and deleted entries. */
3170 		base_entries = got_object_tree_get_entries(base_tree);
3171 		SIMPLEQ_FOREACH(te, &base_entries->head, entry) {
3172 			struct got_commitable *ct = NULL;
3173 
3174 			if (S_ISDIR(te->mode)) {
3175 				int modified;
3176 				err = got_object_tree_entry_dup(&new_te, te);
3177 				if (err)
3178 					goto done;
3179 				err = match_modified_subtree(&modified, te,
3180 				    path_base_tree, commitable_paths);
3181 				if (err)
3182 					goto done;
3183 				/* Avoid recursion into unmodified subtrees. */
3184 				if (modified) {
3185 					free(new_te->id);
3186 					err = write_subtree(&new_te->id, te,
3187 					    path_base_tree, commitable_paths,
3188 					    status_cb, status_arg, repo);
3189 					if (err)
3190 						goto done;
3191 				}
3192 				err = insert_tree_entry(new_te, &paths);
3193 				if (err)
3194 					goto done;
3195 				continue;
3196 			}
3197 
3198 			err = match_deleted_or_modified_ct(&ct, te,
3199 			    path_base_tree, commitable_paths);
3200 			if (ct) {
3201 				/* NB: Deleted entries get dropped here. */
3202 				if (ct->status == GOT_STATUS_MODIFY) {
3203 					err = alloc_modified_blob_tree_entry(
3204 					    &new_te, te, ct);
3205 					if (err)
3206 						goto done;
3207 					err = insert_tree_entry(new_te, &paths);
3208 					if (err)
3209 						goto done;
3210 				}
3211 				err = report_ct_status(ct, status_cb,
3212 				    status_arg);
3213 				if (err)
3214 					goto done;
3215 			} else {
3216 				/* Entry is unchanged; just copy it. */
3217 				err = got_object_tree_entry_dup(&new_te, te);
3218 				if (err)
3219 					goto done;
3220 				err = insert_tree_entry(new_te, &paths);
3221 				if (err)
3222 					goto done;
3223 			}
3224 		}
3225 	}
3226 
3227 	/* Write new list of entries; deleted entries have been dropped. */
3228 	TAILQ_FOREACH(pe, &paths, entry) {
3229 		struct got_tree_entry *te = pe->data;
3230 		new_tree_entries.nentries++;
3231 		SIMPLEQ_INSERT_TAIL(&new_tree_entries.head, te, entry);
3232 	}
3233 	err = got_object_tree_create(new_tree_id, &new_tree_entries, repo);
3234 done:
3235 	got_object_tree_entries_close(&new_tree_entries);
3236 	got_pathlist_free(&paths);
3237 	return err;
3238 }
3239 
3240 static const struct got_error *
3241 update_fileindex_after_commit(struct got_pathlist_head *commitable_paths,
3242     struct got_object_id *new_base_commit_id, struct got_fileindex *fileindex)
3243 {
3244 	const struct got_error *err = NULL;
3245 	struct got_pathlist_entry *pe;
3246 
3247 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3248 		struct got_fileindex_entry *ie;
3249 		struct got_commitable *ct = pe->data;
3250 
3251 		ie = got_fileindex_entry_get(fileindex, pe->path);
3252 		if (ie) {
3253 			if (ct->status == GOT_STATUS_DELETE) {
3254 				got_fileindex_entry_remove(fileindex, ie);
3255 				got_fileindex_entry_free(ie);
3256 			} else
3257 				err = got_fileindex_entry_update(ie,
3258 				    ct->ondisk_path, ct->blob_id->sha1,
3259 				    new_base_commit_id->sha1, 1);
3260 		} else {
3261 			err = got_fileindex_entry_alloc(&ie,
3262 			    ct->ondisk_path, pe->path, ct->blob_id->sha1,
3263 			    new_base_commit_id->sha1);
3264 			if (err)
3265 				break;
3266 			err = got_fileindex_entry_add(fileindex, ie);
3267 			if (err)
3268 				break;
3269 		}
3270 	}
3271 	return err;
3272 }
3273 
3274 static const struct got_error *
3275 check_ct_out_of_date(struct got_commitable *ct, struct got_repository *repo,
3276 	struct got_object_id *head_commit_id)
3277 {
3278 	const struct got_error *err = NULL;
3279 	struct got_object_id *id_in_head = NULL, *id = NULL;
3280 	struct got_commit_object *commit = NULL;
3281 	char *path = NULL;
3282 	const char *ct_path = ct->in_repo_path;
3283 
3284 	while (ct_path[0] == '/')
3285 		ct_path++;
3286 
3287 	/*
3288 	 * Ensure that no modifications were made to files *and their parents*
3289 	 * in commits between the file's base commit and the branch head.
3290 	 *
3291 	 * Checking the parents is important for detecting conflicting tree
3292 	 * configurations (files or parent folders might have been moved,
3293 	 * deleted, added again, etc.). Such changes need to be merged with
3294 	 * local changes before a commit can occur.
3295 	 *
3296 	 * The implication is that the file's (parent) entry in the root
3297 	 * directory must have the same ID in all relevant commits.
3298 	 */
3299 	if (ct->status != GOT_STATUS_ADD) {
3300 		struct got_object_qid *pid;
3301 		char *slash;
3302 		struct got_object_id *root_entry_id = NULL;
3303 
3304 		/* Trivial case: base commit == head commit */
3305 		if (got_object_id_cmp(ct->base_commit_id, head_commit_id) == 0)
3306 			return NULL;
3307 
3308 		/* Compute the path to the root directory's entry. */
3309 		path = strdup(ct_path);
3310 		if (path == NULL) {
3311 			err = got_error_from_errno("strdup");
3312 			goto done;
3313 		}
3314 		slash = strchr(path, '/');
3315 		if (slash)
3316 			*slash = '\0';
3317 
3318 		err = got_object_open_as_commit(&commit, repo, head_commit_id);
3319 		if (err)
3320 			goto done;
3321 
3322 		err = got_object_id_by_path(&root_entry_id, repo,
3323 		    head_commit_id, path);
3324 		if (err)
3325 			goto done;
3326 
3327 		pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(commit));
3328 		while (pid) {
3329 			struct got_commit_object *pcommit;
3330 
3331 			err = got_object_id_by_path(&id, repo, pid->id, path);
3332 			if (err) {
3333 				if (err->code != GOT_ERR_NO_TREE_ENTRY)
3334 					goto done;
3335 				err = NULL;
3336 				break;
3337 			}
3338 
3339 			err = got_object_id_by_path(&id, repo, pid->id, path);
3340 			if (err)
3341 				goto done;
3342 
3343 			if (got_object_id_cmp(id, root_entry_id) != 0) {
3344 				err = got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3345 				break;
3346 			}
3347 
3348 			if (got_object_id_cmp(pid->id, ct->base_commit_id) == 0)
3349 				break; /* all relevant commits scanned */
3350 
3351 			err = got_object_open_as_commit(&pcommit, repo,
3352 			    pid->id);
3353 			if (err)
3354 				goto done;
3355 
3356 			got_object_commit_close(commit);
3357 			commit = pcommit;
3358 			pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(
3359 			    commit));
3360 		}
3361 	} else {
3362 		/* Require that added files don't exist in the branch head. */
3363 		err = got_object_id_by_path(&id_in_head, repo, head_commit_id,
3364 		    ct_path);
3365 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
3366 			goto done;
3367 		err = id_in_head ? got_error(GOT_ERR_COMMIT_OUT_OF_DATE) : NULL;
3368 	}
3369 done:
3370 	if (commit)
3371 		got_object_commit_close(commit);
3372 	free(id_in_head);
3373 	free(id);
3374 	free(path);
3375 	return err;
3376 }
3377 
3378 const struct got_error *
3379 commit_worktree(struct got_object_id **new_commit_id,
3380     struct got_pathlist_head *commitable_paths,
3381     struct got_object_id *head_commit_id, struct got_worktree *worktree,
3382     const char *ondisk_path, const char *author, const char *committer,
3383     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3384     got_worktree_status_cb status_cb, void *status_arg,
3385     struct got_repository *repo)
3386 {
3387 	const struct got_error *err = NULL, *unlockerr = NULL;
3388 	struct got_pathlist_entry *pe;
3389 	const char *head_ref_name = NULL;
3390 	struct got_commit_object *head_commit = NULL;
3391 	struct got_reference *head_ref2 = NULL;
3392 	struct got_object_id *head_commit_id2 = NULL;
3393 	struct got_tree_object *head_tree = NULL;
3394 	struct got_object_id *new_tree_id = NULL;
3395 	struct got_object_id_queue parent_ids;
3396 	struct got_object_qid *pid = NULL;
3397 	char *logmsg = NULL;
3398 
3399 	*new_commit_id = NULL;
3400 
3401 	SIMPLEQ_INIT(&parent_ids);
3402 
3403 	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
3404 	if (err)
3405 		goto done;
3406 
3407 	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
3408 	if (err)
3409 		goto done;
3410 
3411 	if (commit_msg_cb != NULL) {
3412 		err = commit_msg_cb(commitable_paths, &logmsg, commit_arg);
3413 		if (err)
3414 			goto done;
3415 	}
3416 
3417 	if (logmsg == NULL || strlen(logmsg) == 0) {
3418 		err = got_error(GOT_ERR_COMMIT_MSG_EMPTY);
3419 		goto done;
3420 	}
3421 
3422 	/* Create blobs from added and modified files and record their IDs. */
3423 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3424 		struct got_commitable *ct = pe->data;
3425 		char *ondisk_path;
3426 
3427 		if (ct->status != GOT_STATUS_ADD &&
3428 		    ct->status != GOT_STATUS_MODIFY)
3429 			continue;
3430 
3431 		if (asprintf(&ondisk_path, "%s/%s",
3432 		    worktree->root_path, pe->path) == -1) {
3433 			err = got_error_from_errno("asprintf");
3434 			goto done;
3435 		}
3436 		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
3437 		free(ondisk_path);
3438 		if (err)
3439 			goto done;
3440 	}
3441 
3442 	/* Recursively write new tree objects. */
3443 	err = write_tree(&new_tree_id, head_tree, "/", commitable_paths,
3444 	    status_cb, status_arg, repo);
3445 	if (err)
3446 		goto done;
3447 
3448 	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
3449 	if (err)
3450 		goto done;
3451 	SIMPLEQ_INSERT_TAIL(&parent_ids, pid, entry);
3452 	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
3453 	    1, author, time(NULL), committer, time(NULL), logmsg, repo);
3454 	got_object_qid_free(pid);
3455 	if (logmsg != NULL)
3456 		free(logmsg);
3457 	if (err)
3458 		goto done;
3459 
3460 	/* Check if a concurrent commit to our branch has occurred. */
3461 	head_ref_name = got_worktree_get_head_ref_name(worktree);
3462 	if (head_ref_name == NULL) {
3463 		err = got_error_from_errno("got_worktree_get_head_ref_name");
3464 		goto done;
3465 	}
3466 	/* Lock the reference here to prevent concurrent modification. */
3467 	err = got_ref_open(&head_ref2, repo, head_ref_name, 1);
3468 	if (err)
3469 		goto done;
3470 	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
3471 	if (err)
3472 		goto done;
3473 	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
3474 		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
3475 		goto done;
3476 	}
3477 	/* Update branch head in repository. */
3478 	err = got_ref_change_ref(head_ref2, *new_commit_id);
3479 	if (err)
3480 		goto done;
3481 	err = got_ref_write(head_ref2, repo);
3482 	if (err)
3483 		goto done;
3484 
3485 	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
3486 	if (err)
3487 		goto done;
3488 
3489 	err = ref_base_commit(worktree, repo);
3490 	if (err)
3491 		goto done;
3492 done:
3493 	if (head_tree)
3494 		got_object_tree_close(head_tree);
3495 	if (head_commit)
3496 		got_object_commit_close(head_commit);
3497 	free(head_commit_id2);
3498 	if (head_ref2) {
3499 		unlockerr = got_ref_unlock(head_ref2);
3500 		if (unlockerr && err == NULL)
3501 			err = unlockerr;
3502 		got_ref_close(head_ref2);
3503 	}
3504 	return err;
3505 }
3506 
3507 const struct got_error *
3508 got_worktree_commit(struct got_object_id **new_commit_id,
3509     struct got_worktree *worktree, const char *ondisk_path,
3510     const char *author, const char *committer,
3511     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3512     got_worktree_status_cb status_cb, void *status_arg,
3513     struct got_repository *repo)
3514 {
3515 	const struct got_error *err = NULL, *unlockerr = NULL, *sync_err;
3516 	struct got_fileindex *fileindex = NULL;
3517 	char *fileindex_path = NULL, *relpath = NULL;
3518 	struct got_pathlist_head commitable_paths;
3519 	struct collect_commitables_arg cc_arg;
3520 	struct got_pathlist_entry *pe;
3521 	struct got_reference *head_ref = NULL;
3522 	struct got_object_id *head_commit_id = NULL;
3523 
3524 	*new_commit_id = NULL;
3525 
3526 	TAILQ_INIT(&commitable_paths);
3527 
3528 	err = lock_worktree(worktree, LOCK_EX);
3529 	if (err)
3530 		goto done;
3531 
3532 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3533 	if (err)
3534 		goto done;
3535 
3536 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3537 	if (err)
3538 		goto done;
3539 
3540 	if (ondisk_path) {
3541 		if (strcmp(ondisk_path, worktree->root_path) == 0) {
3542 			relpath = strdup("");
3543 			if (relpath == NULL) {
3544 				err = got_error_from_errno("strdup");
3545 				goto done;
3546 			}
3547 		} else {
3548 			err = got_path_skip_common_ancestor(&relpath,
3549 			    worktree->root_path, ondisk_path);
3550 			if (err)
3551 				return err;
3552 		}
3553 	}
3554 
3555 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3556 	if (err)
3557 		goto done;
3558 
3559 	cc_arg.commitable_paths = &commitable_paths;
3560 	cc_arg.worktree = worktree;
3561 	cc_arg.repo = repo;
3562 	err = worktree_status(worktree, relpath ? relpath : "",
3563 	    fileindex, repo, collect_commitables, &cc_arg, NULL, NULL);
3564 	if (err)
3565 		goto done;
3566 
3567 	if (TAILQ_EMPTY(&commitable_paths)) {
3568 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3569 		goto done;
3570 	}
3571 
3572 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3573 		struct got_commitable *ct = pe->data;
3574 		err = check_ct_out_of_date(ct, repo, head_commit_id);
3575 		if (err)
3576 			goto done;
3577 	}
3578 
3579 	err = commit_worktree(new_commit_id, &commitable_paths,
3580 	    head_commit_id, worktree, ondisk_path, author, committer,
3581 	    commit_msg_cb, commit_arg, status_cb, status_arg, repo);
3582 	if (err)
3583 		goto done;
3584 
3585 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
3586 	    fileindex);
3587 	sync_err = sync_fileindex(fileindex, fileindex_path);
3588 	if (sync_err && err == NULL)
3589 		err = sync_err;
3590 done:
3591 	if (fileindex)
3592 		got_fileindex_free(fileindex);
3593 	free(fileindex_path);
3594 	free(relpath);
3595 	unlockerr = lock_worktree(worktree, LOCK_SH);
3596 	if (unlockerr && err == NULL)
3597 		err = unlockerr;
3598 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3599 		struct got_commitable *ct = pe->data;
3600 		free_commitable(ct);
3601 	}
3602 	got_pathlist_free(&commitable_paths);
3603 	return err;
3604 }
3605 
3606 const char *
3607 got_commitable_get_path(struct got_commitable *ct)
3608 {
3609 	return ct->path;
3610 }
3611 
3612 unsigned int
3613 got_commitable_get_status(struct got_commitable *ct)
3614 {
3615 	return ct->status;
3616 }
3617 
3618 struct check_rebase_ok_arg {
3619 	struct got_worktree *worktree;
3620 	struct got_repository *repo;
3621 	int rebase_in_progress;
3622 };
3623 
3624 static const struct got_error *
3625 check_rebase_ok(void *arg, struct got_fileindex_entry *ie)
3626 {
3627 	const struct got_error *err = NULL;
3628 	struct check_rebase_ok_arg *a = arg;
3629 	unsigned char status;
3630 	struct stat sb;
3631 	char *ondisk_path;
3632 
3633 	if (!a->rebase_in_progress) {
3634 		/* Reject rebase of a work tree with mixed base commits. */
3635 		if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
3636 		    SHA1_DIGEST_LENGTH))
3637 			return got_error(GOT_ERR_MIXED_COMMITS);
3638 	}
3639 
3640 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
3641 	    == -1)
3642 		return got_error_from_errno("asprintf");
3643 
3644 	/* Reject rebase of a work tree with modified or conflicted files. */
3645 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
3646 	free(ondisk_path);
3647 	if (err)
3648 		return err;
3649 
3650 	if (a->rebase_in_progress) {
3651 		if (status == GOT_STATUS_CONFLICT)
3652 			return got_error(GOT_ERR_CONFLICTS);
3653 	} else if (status != GOT_STATUS_NO_CHANGE)
3654 		return got_error(GOT_ERR_MODIFIED);
3655 
3656 	return NULL;
3657 }
3658 
3659 const struct got_error *
3660 got_worktree_rebase_prepare(struct got_reference **new_base_branch_ref,
3661     struct got_reference **tmp_branch, struct got_fileindex **fileindex,
3662     struct got_worktree *worktree, struct got_reference *branch,
3663     struct got_repository *repo)
3664 {
3665 	const struct got_error *err = NULL;
3666 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
3667 	char *branch_ref_name = NULL;
3668 	char *fileindex_path = NULL;
3669 	struct check_rebase_ok_arg ok_arg;
3670 	struct got_reference *wt_branch = NULL, *branch_ref = NULL;
3671 
3672 	*new_base_branch_ref = NULL;
3673 	*tmp_branch = NULL;
3674 	*fileindex = NULL;
3675 
3676 	err = lock_worktree(worktree, LOCK_EX);
3677 	if (err)
3678 		return err;
3679 
3680 	err = open_fileindex(fileindex, &fileindex_path, worktree);
3681 	if (err)
3682 		goto done;
3683 
3684 	ok_arg.worktree = worktree;
3685 	ok_arg.repo = repo;
3686 	ok_arg.rebase_in_progress = 0;
3687 	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
3688 	    &ok_arg);
3689 	if (err)
3690 		goto done;
3691 
3692 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3693 	if (err)
3694 		goto done;
3695 
3696 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3697 	if (err)
3698 		goto done;
3699 
3700 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3701 	if (err)
3702 		goto done;
3703 
3704 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
3705 	    0);
3706 	if (err)
3707 		goto done;
3708 
3709 	err = got_ref_alloc_symref(new_base_branch_ref,
3710 	    new_base_branch_ref_name, wt_branch);
3711 	if (err)
3712 		goto done;
3713 	err = got_ref_write(*new_base_branch_ref, repo);
3714 	if (err)
3715 		goto done;
3716 
3717 	/* TODO Lock original branch's ref while rebasing? */
3718 
3719 	err = got_ref_alloc_symref(&branch_ref, branch_ref_name, branch);
3720 	if (err)
3721 		goto done;
3722 
3723 	err = got_ref_write(branch_ref, repo);
3724 	if (err)
3725 		goto done;
3726 
3727 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
3728 	    worktree->base_commit_id);
3729 	if (err)
3730 		goto done;
3731 	err = got_ref_write(*tmp_branch, repo);
3732 	if (err)
3733 		goto done;
3734 
3735 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
3736 	if (err)
3737 		goto done;
3738 done:
3739 	free(fileindex_path);
3740 	free(tmp_branch_name);
3741 	free(new_base_branch_ref_name);
3742 	free(branch_ref_name);
3743 	if (branch_ref)
3744 		got_ref_close(branch_ref);
3745 	if (wt_branch)
3746 		got_ref_close(wt_branch);
3747 	if (err) {
3748 		if (*new_base_branch_ref) {
3749 			got_ref_close(*new_base_branch_ref);
3750 			*new_base_branch_ref = NULL;
3751 		}
3752 		if (*tmp_branch) {
3753 			got_ref_close(*tmp_branch);
3754 			*tmp_branch = NULL;
3755 		}
3756 		if (*fileindex) {
3757 			got_fileindex_free(*fileindex);
3758 			*fileindex = NULL;
3759 		}
3760 		lock_worktree(worktree, LOCK_SH);
3761 	}
3762 	return err;
3763 }
3764 
3765 const struct got_error *
3766 got_worktree_rebase_continue(struct got_object_id **commit_id,
3767     struct got_reference **new_base_branch, struct got_reference **tmp_branch,
3768     struct got_reference **branch, struct got_fileindex **fileindex,
3769     struct got_worktree *worktree, struct got_repository *repo)
3770 {
3771 	const struct got_error *err;
3772 	char *commit_ref_name = NULL, *new_base_branch_ref_name = NULL;
3773 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
3774 	struct got_reference *commit_ref = NULL, *branch_ref = NULL;
3775 	char *fileindex_path = NULL;
3776 
3777 	*commit_id = NULL;
3778 	*new_base_branch = NULL;
3779 	*tmp_branch = NULL;
3780 	*branch = NULL;
3781 	*fileindex = NULL;
3782 
3783 	err = lock_worktree(worktree, LOCK_EX);
3784 	if (err)
3785 		return err;
3786 
3787 	err = open_fileindex(fileindex, &fileindex_path, worktree);
3788 	if (err)
3789 		goto done;
3790 
3791 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3792 	if (err)
3793 		return err;
3794 
3795 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3796 	if (err)
3797 		goto done;
3798 
3799 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3800 	if (err)
3801 		goto done;
3802 
3803 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3804 	if (err)
3805 		goto done;
3806 
3807 	err = got_ref_open(&branch_ref, repo, branch_ref_name, 0);
3808 	if (err)
3809 		goto done;
3810 
3811 	err = got_ref_open(branch, repo,
3812 	    got_ref_get_symref_target(branch_ref), 0);
3813 	if (err)
3814 		goto done;
3815 
3816 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3817 	if (err)
3818 		goto done;
3819 
3820 	err = got_ref_resolve(commit_id, repo, commit_ref);
3821 	if (err)
3822 		goto done;
3823 
3824 	err = got_ref_open(new_base_branch, repo,
3825 	    new_base_branch_ref_name, 0);
3826 	if (err)
3827 		goto done;
3828 
3829 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
3830 	if (err)
3831 		goto done;
3832 done:
3833 	free(commit_ref_name);
3834 	free(branch_ref_name);
3835 	free(fileindex_path);
3836 	if (commit_ref)
3837 		got_ref_close(commit_ref);
3838 	if (branch_ref)
3839 		got_ref_close(branch_ref);
3840 	if (err) {
3841 		free(*commit_id);
3842 		*commit_id = NULL;
3843 		if (*tmp_branch) {
3844 			got_ref_close(*tmp_branch);
3845 			*tmp_branch = NULL;
3846 		}
3847 		if (*new_base_branch) {
3848 			got_ref_close(*new_base_branch);
3849 			*new_base_branch = NULL;
3850 		}
3851 		if (*branch) {
3852 			got_ref_close(*branch);
3853 			*branch = NULL;
3854 		}
3855 		if (*fileindex) {
3856 			got_fileindex_free(*fileindex);
3857 			*fileindex = NULL;
3858 		}
3859 		lock_worktree(worktree, LOCK_SH);
3860 	}
3861 	return err;
3862 }
3863 
3864 const struct got_error *
3865 got_worktree_rebase_in_progress(int *in_progress, struct got_worktree *worktree)
3866 {
3867 	const struct got_error *err;
3868 	char *tmp_branch_name = NULL;
3869 
3870 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3871 	if (err)
3872 		return err;
3873 
3874 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
3875 	free(tmp_branch_name);
3876 	return NULL;
3877 }
3878 
3879 static const struct got_error *
3880 collect_rebase_commit_msg(struct got_pathlist_head *commitable_paths,
3881     char **logmsg, void *arg)
3882 {
3883 	*logmsg = arg;
3884 	return NULL;
3885 }
3886 
3887 static const struct got_error *
3888 rebase_status(void *arg, unsigned char status, const char *path,
3889     struct got_object_id *blob_id, struct got_object_id *commit_id)
3890 {
3891 	return NULL;
3892 }
3893 
3894 struct collect_merged_paths_arg {
3895 	got_worktree_checkout_cb progress_cb;
3896 	void *progress_arg;
3897 	struct got_pathlist_head *merged_paths;
3898 };
3899 
3900 static const struct got_error *
3901 collect_merged_paths(void *arg, unsigned char status, const char *path)
3902 {
3903 	const struct got_error *err;
3904 	struct collect_merged_paths_arg *a = arg;
3905 	char *p;
3906 	struct got_pathlist_entry *new;
3907 
3908 	err = (*a->progress_cb)(a->progress_arg, status, path);
3909 	if (err)
3910 		return err;
3911 
3912 	if (status != GOT_STATUS_MERGE &&
3913 	    status != GOT_STATUS_ADD &&
3914 	    status != GOT_STATUS_DELETE &&
3915 	    status != GOT_STATUS_CONFLICT)
3916 		return NULL;
3917 
3918 	p = strdup(path);
3919 	if (p == NULL)
3920 		return got_error_from_errno("strdup");
3921 
3922 	err = got_pathlist_insert(&new, a->merged_paths, p, NULL);
3923 	if (err || new == NULL)
3924 		free(p);
3925 	return err;
3926 }
3927 
3928 void
3929 got_worktree_rebase_pathlist_free(struct got_pathlist_head *merged_paths)
3930 {
3931 	struct got_pathlist_entry *pe;
3932 
3933 	TAILQ_FOREACH(pe, merged_paths, entry)
3934 		free((char *)pe->path);
3935 
3936 	got_pathlist_free(merged_paths);
3937 }
3938 
3939 static const struct got_error *
3940 store_commit_id(const char *commit_ref_name, struct got_object_id *commit_id,
3941     struct got_repository *repo)
3942 {
3943 	const struct got_error *err;
3944 	struct got_reference *commit_ref = NULL;
3945 
3946 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3947 	if (err) {
3948 		if (err->code != GOT_ERR_NOT_REF)
3949 			goto done;
3950 		err = got_ref_alloc(&commit_ref, commit_ref_name, commit_id);
3951 		if (err)
3952 			goto done;
3953 		err = got_ref_write(commit_ref, repo);
3954 		if (err)
3955 			goto done;
3956 	} else {
3957 		struct got_object_id *stored_id;
3958 		int cmp;
3959 
3960 		err = got_ref_resolve(&stored_id, repo, commit_ref);
3961 		if (err)
3962 			goto done;
3963 		cmp = got_object_id_cmp(commit_id, stored_id);
3964 		free(stored_id);
3965 		if (cmp != 0) {
3966 			err = got_error(GOT_ERR_REBASE_COMMITID);
3967 			goto done;
3968 		}
3969 	}
3970 done:
3971 	if (commit_ref)
3972 		got_ref_close(commit_ref);
3973 	return err;
3974 }
3975 
3976 static const struct got_error *
3977 rebase_merge_files(struct got_pathlist_head *merged_paths,
3978     const char *commit_ref_name, struct got_worktree *worktree,
3979     struct got_fileindex *fileindex, struct got_object_id *parent_commit_id,
3980     struct got_object_id *commit_id, struct got_repository *repo,
3981     got_worktree_checkout_cb progress_cb, void *progress_arg,
3982     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
3983 {
3984 	const struct got_error *err;
3985 	struct got_reference *commit_ref = NULL;
3986 	struct collect_merged_paths_arg cmp_arg;
3987 	char *fileindex_path;
3988 
3989 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
3990 
3991 	err = get_fileindex_path(&fileindex_path, worktree);
3992 	if (err)
3993 		return err;
3994 
3995 	cmp_arg.progress_cb = progress_cb;
3996 	cmp_arg.progress_arg = progress_arg;
3997 	cmp_arg.merged_paths = merged_paths;
3998 	err = merge_files(worktree, fileindex, fileindex_path,
3999 	    parent_commit_id, commit_id, repo, collect_merged_paths,
4000 	    &cmp_arg, cancel_cb, cancel_arg);
4001 	if (commit_ref)
4002 		got_ref_close(commit_ref);
4003 	return err;
4004 }
4005 
4006 const struct got_error *
4007 got_worktree_rebase_merge_files(struct got_pathlist_head *merged_paths,
4008     struct got_worktree *worktree, struct got_fileindex *fileindex,
4009     struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
4010     struct got_repository *repo,
4011     got_worktree_checkout_cb progress_cb, void *progress_arg,
4012     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
4013 {
4014 	const struct got_error *err;
4015 	char *commit_ref_name;
4016 
4017 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4018 	if (err)
4019 		return err;
4020 
4021 	err = store_commit_id(commit_ref_name, commit_id, repo);
4022 	if (err)
4023 		goto done;
4024 
4025 	err = rebase_merge_files(merged_paths, commit_ref_name, worktree,
4026 	    fileindex, parent_commit_id, commit_id, repo, progress_cb,
4027 	    progress_arg, cancel_cb, cancel_arg);
4028 done:
4029 	free(commit_ref_name);
4030 	return err;
4031 }
4032 
4033 const struct got_error *
4034 got_worktree_histedit_merge_files(struct got_pathlist_head *merged_paths,
4035     struct got_worktree *worktree, struct got_fileindex *fileindex,
4036     struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
4037     struct got_repository *repo,
4038     got_worktree_checkout_cb progress_cb, void *progress_arg,
4039     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
4040 {
4041 	const struct got_error *err;
4042 	char *commit_ref_name;
4043 
4044 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4045 	if (err)
4046 		return err;
4047 
4048 	err = store_commit_id(commit_ref_name, commit_id, repo);
4049 	if (err)
4050 		goto done;
4051 
4052 	err = rebase_merge_files(merged_paths, commit_ref_name, worktree,
4053 	    fileindex, parent_commit_id, commit_id, repo, progress_cb,
4054 	    progress_arg, cancel_cb, cancel_arg);
4055 done:
4056 	free(commit_ref_name);
4057 	return err;
4058 }
4059 
4060 static const struct got_error *
4061 rebase_commit(struct got_object_id **new_commit_id,
4062     struct got_pathlist_head *merged_paths, struct got_reference *commit_ref,
4063     struct got_worktree *worktree, struct got_fileindex *fileindex,
4064     struct got_reference *tmp_branch, struct got_commit_object *orig_commit,
4065     const char *new_logmsg, struct got_repository *repo)
4066 {
4067 	const struct got_error *err, *sync_err;
4068 	struct got_pathlist_head commitable_paths;
4069 	struct collect_commitables_arg cc_arg;
4070 	char *fileindex_path = NULL;
4071 	struct got_reference *head_ref = NULL;
4072 	struct got_object_id *head_commit_id = NULL;
4073 	char *logmsg = NULL;
4074 
4075 	TAILQ_INIT(&commitable_paths);
4076 	*new_commit_id = NULL;
4077 
4078 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
4079 
4080 	err = get_fileindex_path(&fileindex_path, worktree);
4081 	if (err)
4082 		return err;
4083 
4084 	cc_arg.commitable_paths = &commitable_paths;
4085 	cc_arg.worktree = worktree;
4086 	cc_arg.repo = repo;
4087 	/*
4088 	 * If possible get the status of individual files directly to
4089 	 * avoid crawling the entire work tree once per rebased commit.
4090 	 * TODO: Ideally, merged_paths would contain a list of commitables
4091 	 * we could use so we could skip worktree_status() entirely.
4092 	 */
4093 	if (merged_paths) {
4094 		struct got_pathlist_entry *pe;
4095 		if (TAILQ_EMPTY(merged_paths)) {
4096 			err = got_error(GOT_ERR_NO_MERGED_PATHS);
4097 			goto done;
4098 		}
4099 		TAILQ_FOREACH(pe, merged_paths, entry) {
4100 			err = worktree_status(worktree, pe->path, fileindex,
4101 			    repo, collect_commitables, &cc_arg, NULL, NULL);
4102 			if (err)
4103 				goto done;
4104 		}
4105 	} else {
4106 		err = worktree_status(worktree, "", fileindex, repo,
4107 		    collect_commitables, &cc_arg, NULL, NULL);
4108 		if (err)
4109 			goto done;
4110 	}
4111 
4112 	if (TAILQ_EMPTY(&commitable_paths)) {
4113 		/* No-op change; commit will be elided. */
4114 		err = got_ref_delete(commit_ref, repo);
4115 		if (err)
4116 			goto done;
4117 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
4118 		goto done;
4119 	}
4120 
4121 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
4122 	if (err)
4123 		goto done;
4124 
4125 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
4126 	if (err)
4127 		goto done;
4128 
4129 	if (new_logmsg)
4130 		logmsg = strdup(new_logmsg);
4131 	else
4132 		logmsg = strdup(got_object_commit_get_logmsg(orig_commit));
4133 	if (logmsg == NULL)
4134 		return got_error_from_errno("strdup");
4135 
4136 	err = commit_worktree(new_commit_id, &commitable_paths, head_commit_id,
4137 	    worktree, NULL, got_object_commit_get_author(orig_commit),
4138 	    got_object_commit_get_committer(orig_commit),
4139 	    collect_rebase_commit_msg, logmsg, rebase_status, NULL, repo);
4140 	if (err)
4141 		goto done;
4142 
4143 	err = got_ref_change_ref(tmp_branch, *new_commit_id);
4144 	if (err)
4145 		goto done;
4146 
4147 	err = got_ref_delete(commit_ref, repo);
4148 	if (err)
4149 		goto done;
4150 
4151 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
4152 	    fileindex);
4153 	sync_err = sync_fileindex(fileindex, fileindex_path);
4154 	if (sync_err && err == NULL)
4155 		err = sync_err;
4156 done:
4157 	free(fileindex_path);
4158 	free(head_commit_id);
4159 	if (head_ref)
4160 		got_ref_close(head_ref);
4161 	if (err) {
4162 		free(*new_commit_id);
4163 		*new_commit_id = NULL;
4164 	}
4165 	return err;
4166 }
4167 
4168 const struct got_error *
4169 got_worktree_rebase_commit(struct got_object_id **new_commit_id,
4170     struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
4171     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4172     struct got_commit_object *orig_commit,
4173     struct got_object_id *orig_commit_id, struct got_repository *repo)
4174 {
4175 	const struct got_error *err;
4176 	char *commit_ref_name;
4177 	struct got_reference *commit_ref = NULL;
4178 	struct got_object_id *commit_id = NULL;
4179 
4180 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4181 	if (err)
4182 		return err;
4183 
4184 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4185 	if (err)
4186 		goto done;
4187 	err = got_ref_resolve(&commit_id, repo, commit_ref);
4188 	if (err)
4189 		goto done;
4190 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
4191 		err = got_error(GOT_ERR_REBASE_COMMITID);
4192 		goto done;
4193 	}
4194 
4195 	err = rebase_commit(new_commit_id, merged_paths, commit_ref,
4196 	    worktree, fileindex, tmp_branch, orig_commit, NULL, repo);
4197 done:
4198 	if (commit_ref)
4199 		got_ref_close(commit_ref);
4200 	free(commit_ref_name);
4201 	free(commit_id);
4202 	return err;
4203 }
4204 
4205 const struct got_error *
4206 got_worktree_histedit_commit(struct got_object_id **new_commit_id,
4207     struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
4208     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4209     struct got_commit_object *orig_commit,
4210     struct got_object_id *orig_commit_id, const char *new_logmsg,
4211     struct got_repository *repo)
4212 {
4213 	const struct got_error *err;
4214 	char *commit_ref_name;
4215 	struct got_reference *commit_ref = NULL;
4216 	struct got_object_id *commit_id = NULL;
4217 
4218 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4219 	if (err)
4220 		return err;
4221 
4222 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4223 	if (err)
4224 		goto done;
4225 	err = got_ref_resolve(&commit_id, repo, commit_ref);
4226 	if (err)
4227 		goto done;
4228 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
4229 		err = got_error(GOT_ERR_HISTEDIT_COMMITID);
4230 		goto done;
4231 	}
4232 
4233 	err = rebase_commit(new_commit_id, merged_paths, commit_ref,
4234 	    worktree, fileindex, tmp_branch, orig_commit, new_logmsg, repo);
4235 done:
4236 	if (commit_ref)
4237 		got_ref_close(commit_ref);
4238 	free(commit_ref_name);
4239 	free(commit_id);
4240 	return err;
4241 }
4242 
4243 const struct got_error *
4244 got_worktree_rebase_postpone(struct got_worktree *worktree,
4245     struct got_fileindex *fileindex)
4246 {
4247 	if (fileindex)
4248 		got_fileindex_free(fileindex);
4249 	return lock_worktree(worktree, LOCK_SH);
4250 }
4251 
4252 static const struct got_error *
4253 delete_ref(const char *name, struct got_repository *repo)
4254 {
4255 	const struct got_error *err;
4256 	struct got_reference *ref;
4257 
4258 	err = got_ref_open(&ref, repo, name, 0);
4259 	if (err) {
4260 		if (err->code == GOT_ERR_NOT_REF)
4261 			return NULL;
4262 		return err;
4263 	}
4264 
4265 	err = got_ref_delete(ref, repo);
4266 	got_ref_close(ref);
4267 	return err;
4268 }
4269 
4270 static const struct got_error *
4271 delete_rebase_refs(struct got_worktree *worktree, struct got_repository *repo)
4272 {
4273 	const struct got_error *err;
4274 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
4275 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
4276 
4277 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
4278 	if (err)
4279 		goto done;
4280 	err = delete_ref(tmp_branch_name, repo);
4281 	if (err)
4282 		goto done;
4283 
4284 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
4285 	if (err)
4286 		goto done;
4287 	err = delete_ref(new_base_branch_ref_name, repo);
4288 	if (err)
4289 		goto done;
4290 
4291 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
4292 	if (err)
4293 		goto done;
4294 	err = delete_ref(branch_ref_name, repo);
4295 	if (err)
4296 		goto done;
4297 
4298 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4299 	if (err)
4300 		goto done;
4301 	err = delete_ref(commit_ref_name, repo);
4302 	if (err)
4303 		goto done;
4304 
4305 done:
4306 	free(tmp_branch_name);
4307 	free(new_base_branch_ref_name);
4308 	free(branch_ref_name);
4309 	free(commit_ref_name);
4310 	return err;
4311 }
4312 
4313 const struct got_error *
4314 got_worktree_rebase_complete(struct got_worktree *worktree,
4315     struct got_fileindex *fileindex, struct got_reference *new_base_branch,
4316     struct got_reference *tmp_branch, struct got_reference *rebased_branch,
4317     struct got_repository *repo)
4318 {
4319 	const struct got_error *err, *unlockerr;
4320 	struct got_object_id *new_head_commit_id = NULL;
4321 
4322 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
4323 	if (err)
4324 		return err;
4325 
4326 	err = got_ref_change_ref(rebased_branch, new_head_commit_id);
4327 	if (err)
4328 		goto done;
4329 
4330 	err = got_ref_write(rebased_branch, repo);
4331 	if (err)
4332 		goto done;
4333 
4334 	err = got_worktree_set_head_ref(worktree, rebased_branch);
4335 	if (err)
4336 		goto done;
4337 
4338 	err = delete_rebase_refs(worktree, repo);
4339 done:
4340 	if (fileindex)
4341 		got_fileindex_free(fileindex);
4342 	free(new_head_commit_id);
4343 	unlockerr = lock_worktree(worktree, LOCK_SH);
4344 	if (unlockerr && err == NULL)
4345 		err = unlockerr;
4346 	return err;
4347 }
4348 
4349 struct collect_revertible_paths_arg {
4350 	struct got_pathlist_head *revertible_paths;
4351 	struct got_worktree *worktree;
4352 };
4353 
4354 static const struct got_error *
4355 collect_revertible_paths(void *arg, unsigned char status, const char *relpath,
4356     struct got_object_id *blob_id, struct got_object_id *commit_id)
4357 {
4358 	struct collect_revertible_paths_arg *a = arg;
4359 	const struct got_error *err = NULL;
4360 	struct got_pathlist_entry *new = NULL;
4361 	char *path = NULL;
4362 
4363 	if (status != GOT_STATUS_ADD &&
4364 	    status != GOT_STATUS_DELETE &&
4365 	    status != GOT_STATUS_MODIFY &&
4366 	    status != GOT_STATUS_CONFLICT &&
4367 	    status != GOT_STATUS_MISSING)
4368 		return NULL;
4369 
4370 	if (asprintf(&path, "%s/%s", a->worktree->root_path, relpath) == -1)
4371 		return got_error_from_errno("asprintf");
4372 
4373 	err = got_pathlist_insert(&new, a->revertible_paths, path, NULL);
4374 	if (err || new == NULL)
4375 		free(path);
4376 	return err;
4377 }
4378 
4379 const struct got_error *
4380 got_worktree_rebase_abort(struct got_worktree *worktree,
4381     struct got_fileindex *fileindex, struct got_repository *repo,
4382     struct got_reference *new_base_branch,
4383      got_worktree_checkout_cb progress_cb, void *progress_arg)
4384 {
4385 	const struct got_error *err, *unlockerr, *sync_err;
4386 	struct got_reference *resolved = NULL;
4387 	struct got_object_id *commit_id = NULL;
4388 	char *fileindex_path = NULL;
4389 	struct got_pathlist_head revertible_paths;
4390 	struct got_pathlist_entry *pe;
4391 	struct collect_revertible_paths_arg crp_arg;
4392 	struct got_object_id *tree_id = NULL;
4393 
4394 	TAILQ_INIT(&revertible_paths);
4395 
4396 	err = lock_worktree(worktree, LOCK_EX);
4397 	if (err)
4398 		return err;
4399 
4400 	err = got_ref_open(&resolved, repo,
4401 	    got_ref_get_symref_target(new_base_branch), 0);
4402 	if (err)
4403 		goto done;
4404 
4405 	err = got_worktree_set_head_ref(worktree, resolved);
4406 	if (err)
4407 		goto done;
4408 
4409 	/*
4410 	 * XXX commits to the base branch could have happened while
4411 	 * we were busy rebasing; should we store the original commit ID
4412 	 * when rebase begins and read it back here?
4413 	 */
4414 	err = got_ref_resolve(&commit_id, repo, resolved);
4415 	if (err)
4416 		goto done;
4417 
4418 	err = got_worktree_set_base_commit_id(worktree, repo, commit_id);
4419 	if (err)
4420 		goto done;
4421 
4422 	err = got_object_id_by_path(&tree_id, repo,
4423 	    worktree->base_commit_id, worktree->path_prefix);
4424 	if (err)
4425 		goto done;
4426 
4427 	err = delete_rebase_refs(worktree, repo);
4428 	if (err)
4429 		goto done;
4430 
4431 	err = get_fileindex_path(&fileindex_path, worktree);
4432 	if (err)
4433 		goto done;
4434 
4435 	crp_arg.revertible_paths = &revertible_paths;
4436 	crp_arg.worktree = worktree;
4437 	err = worktree_status(worktree, "", fileindex, repo,
4438 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4439 	if (err)
4440 		goto done;
4441 
4442 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4443 		err = revert_file(worktree, fileindex, pe->path,
4444 		    progress_cb, progress_arg, repo);
4445 		if (err)
4446 			goto sync;
4447 	}
4448 
4449 	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
4450 	    repo, progress_cb, progress_arg, NULL, NULL);
4451 sync:
4452 	sync_err = sync_fileindex(fileindex, fileindex_path);
4453 	if (sync_err && err == NULL)
4454 		err = sync_err;
4455 done:
4456 	got_ref_close(resolved);
4457 	free(tree_id);
4458 	free(commit_id);
4459 	if (fileindex)
4460 		got_fileindex_free(fileindex);
4461 	free(fileindex_path);
4462 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4463 		free((char *)pe->path);
4464 	got_pathlist_free(&revertible_paths);
4465 
4466 	unlockerr = lock_worktree(worktree, LOCK_SH);
4467 	if (unlockerr && err == NULL)
4468 		err = unlockerr;
4469 	return err;
4470 }
4471 
4472 const struct got_error *
4473 got_worktree_histedit_prepare(struct got_reference **tmp_branch,
4474     struct got_reference **branch_ref, struct got_object_id **base_commit_id,
4475     struct got_fileindex **fileindex, struct got_worktree *worktree,
4476     struct got_repository *repo)
4477 {
4478 	const struct got_error *err = NULL;
4479 	char *tmp_branch_name = NULL;
4480 	char *branch_ref_name = NULL;
4481 	char *base_commit_ref_name = NULL;
4482 	char *fileindex_path = NULL;
4483 	struct check_rebase_ok_arg ok_arg;
4484 	struct got_reference *wt_branch = NULL;
4485 	struct got_reference *base_commit_ref = NULL;
4486 
4487 	*tmp_branch = NULL;
4488 	*branch_ref = NULL;
4489 	*base_commit_id = NULL;
4490 	*fileindex = NULL;
4491 
4492 	err = lock_worktree(worktree, LOCK_EX);
4493 	if (err)
4494 		return err;
4495 
4496 	err = open_fileindex(fileindex, &fileindex_path, worktree);
4497 	if (err)
4498 		goto done;
4499 
4500 	ok_arg.worktree = worktree;
4501 	ok_arg.repo = repo;
4502 	ok_arg.rebase_in_progress = 0;
4503 	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
4504 	    &ok_arg);
4505 	if (err)
4506 		goto done;
4507 
4508 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4509 	if (err)
4510 		goto done;
4511 
4512 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4513 	if (err)
4514 		goto done;
4515 
4516 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4517 	    worktree);
4518 	if (err)
4519 		goto done;
4520 
4521 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
4522 	    0);
4523 	if (err)
4524 		goto done;
4525 
4526 	err = got_ref_alloc_symref(branch_ref, branch_ref_name, wt_branch);
4527 	if (err)
4528 		goto done;
4529 
4530 	err = got_ref_write(*branch_ref, repo);
4531 	if (err)
4532 		goto done;
4533 
4534 	err = got_ref_alloc(&base_commit_ref, base_commit_ref_name,
4535 	    worktree->base_commit_id);
4536 	if (err)
4537 		goto done;
4538 	err = got_ref_write(base_commit_ref, repo);
4539 	if (err)
4540 		goto done;
4541 	*base_commit_id = got_object_id_dup(worktree->base_commit_id);
4542 	if (*base_commit_id == NULL) {
4543 		err = got_error_from_errno("got_object_id_dup");
4544 		goto done;
4545 	}
4546 
4547 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
4548 	    worktree->base_commit_id);
4549 	if (err)
4550 		goto done;
4551 	err = got_ref_write(*tmp_branch, repo);
4552 	if (err)
4553 		goto done;
4554 
4555 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
4556 	if (err)
4557 		goto done;
4558 done:
4559 	free(fileindex_path);
4560 	free(tmp_branch_name);
4561 	free(branch_ref_name);
4562 	free(base_commit_ref_name);
4563 	if (wt_branch)
4564 		got_ref_close(wt_branch);
4565 	if (err) {
4566 		if (*branch_ref) {
4567 			got_ref_close(*branch_ref);
4568 			*branch_ref = NULL;
4569 		}
4570 		if (*tmp_branch) {
4571 			got_ref_close(*tmp_branch);
4572 			*tmp_branch = NULL;
4573 		}
4574 		free(*base_commit_id);
4575 		if (*fileindex) {
4576 			got_fileindex_free(*fileindex);
4577 			*fileindex = NULL;
4578 		}
4579 		lock_worktree(worktree, LOCK_SH);
4580 	}
4581 	return err;
4582 }
4583 
4584 const struct got_error *
4585 got_worktree_histedit_postpone(struct got_worktree *worktree,
4586     struct got_fileindex *fileindex)
4587 {
4588 	if (fileindex)
4589 		got_fileindex_free(fileindex);
4590 	return lock_worktree(worktree, LOCK_SH);
4591 }
4592 
4593 const struct got_error *
4594 got_worktree_histedit_in_progress(int *in_progress,
4595     struct got_worktree *worktree)
4596 {
4597 	const struct got_error *err;
4598 	char *tmp_branch_name = NULL;
4599 
4600 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4601 	if (err)
4602 		return err;
4603 
4604 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
4605 	free(tmp_branch_name);
4606 	return NULL;
4607 }
4608 
4609 const struct got_error *
4610 got_worktree_histedit_continue(struct got_object_id **commit_id,
4611     struct got_reference **tmp_branch, struct got_reference **branch_ref,
4612     struct got_object_id **base_commit_id, struct got_fileindex **fileindex,
4613     struct got_worktree *worktree, struct got_repository *repo)
4614 {
4615 	const struct got_error *err;
4616 	char *commit_ref_name = NULL, *base_commit_ref_name = NULL;
4617 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
4618 	struct got_reference *commit_ref = NULL;
4619 	struct got_reference *base_commit_ref = NULL;
4620 	char *fileindex_path = NULL;
4621 
4622 	*commit_id = NULL;
4623 	*tmp_branch = NULL;
4624 	*base_commit_id = NULL;
4625 	*fileindex = NULL;
4626 
4627 	err = lock_worktree(worktree, LOCK_EX);
4628 	if (err)
4629 		return err;
4630 
4631 	err = open_fileindex(fileindex, &fileindex_path, worktree);
4632 	if (err)
4633 		goto done;
4634 
4635 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4636 	if (err)
4637 		return err;
4638 
4639 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4640 	if (err)
4641 		goto done;
4642 
4643 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4644 	if (err)
4645 		goto done;
4646 
4647 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4648 	    worktree);
4649 	if (err)
4650 		goto done;
4651 
4652 	err = got_ref_open(branch_ref, repo, branch_ref_name, 0);
4653 	if (err)
4654 		goto done;
4655 
4656 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4657 	if (err)
4658 		goto done;
4659 	err = got_ref_resolve(commit_id, repo, commit_ref);
4660 	if (err)
4661 		goto done;
4662 
4663 	err = got_ref_open(&base_commit_ref, repo, base_commit_ref_name, 0);
4664 	if (err)
4665 		goto done;
4666 	err = got_ref_resolve(base_commit_id, repo, base_commit_ref);
4667 	if (err)
4668 		goto done;
4669 
4670 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
4671 	if (err)
4672 		goto done;
4673 done:
4674 	free(commit_ref_name);
4675 	free(branch_ref_name);
4676 	free(fileindex_path);
4677 	if (commit_ref)
4678 		got_ref_close(commit_ref);
4679 	if (base_commit_ref)
4680 		got_ref_close(base_commit_ref);
4681 	if (err) {
4682 		free(*commit_id);
4683 		*commit_id = NULL;
4684 		free(*base_commit_id);
4685 		*base_commit_id = NULL;
4686 		if (*tmp_branch) {
4687 			got_ref_close(*tmp_branch);
4688 			*tmp_branch = NULL;
4689 		}
4690 		if (*fileindex) {
4691 			got_fileindex_free(*fileindex);
4692 			*fileindex = NULL;
4693 		}
4694 		lock_worktree(worktree, LOCK_EX);
4695 	}
4696 	return err;
4697 }
4698 
4699 static const struct got_error *
4700 delete_histedit_refs(struct got_worktree *worktree, struct got_repository *repo)
4701 {
4702 	const struct got_error *err;
4703 	char *tmp_branch_name = NULL, *base_commit_ref_name = NULL;
4704 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
4705 
4706 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4707 	if (err)
4708 		goto done;
4709 	err = delete_ref(tmp_branch_name, repo);
4710 	if (err)
4711 		goto done;
4712 
4713 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4714 	    worktree);
4715 	if (err)
4716 		goto done;
4717 	err = delete_ref(base_commit_ref_name, repo);
4718 	if (err)
4719 		goto done;
4720 
4721 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4722 	if (err)
4723 		goto done;
4724 	err = delete_ref(branch_ref_name, repo);
4725 	if (err)
4726 		goto done;
4727 
4728 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4729 	if (err)
4730 		goto done;
4731 	err = delete_ref(commit_ref_name, repo);
4732 	if (err)
4733 		goto done;
4734 done:
4735 	free(tmp_branch_name);
4736 	free(base_commit_ref_name);
4737 	free(branch_ref_name);
4738 	free(commit_ref_name);
4739 	return err;
4740 }
4741 
4742 const struct got_error *
4743 got_worktree_histedit_abort(struct got_worktree *worktree,
4744     struct got_fileindex *fileindex, struct got_repository *repo,
4745     struct got_reference *branch, struct got_object_id *base_commit_id,
4746     got_worktree_checkout_cb progress_cb, void *progress_arg)
4747 {
4748 	const struct got_error *err, *unlockerr, *sync_err;
4749 	struct got_reference *resolved = NULL;
4750 	char *fileindex_path = NULL;
4751 	struct got_pathlist_head revertible_paths;
4752 	struct got_pathlist_entry *pe;
4753 	struct collect_revertible_paths_arg crp_arg;
4754 	struct got_object_id *tree_id = NULL;
4755 
4756 	TAILQ_INIT(&revertible_paths);
4757 
4758 	err = lock_worktree(worktree, LOCK_EX);
4759 	if (err)
4760 		return err;
4761 
4762 	err = got_ref_open(&resolved, repo,
4763 	    got_ref_get_symref_target(branch), 0);
4764 	if (err)
4765 		goto done;
4766 
4767 	err = got_worktree_set_head_ref(worktree, resolved);
4768 	if (err)
4769 		goto done;
4770 
4771 	err = got_worktree_set_base_commit_id(worktree, repo, base_commit_id);
4772 	if (err)
4773 		goto done;
4774 
4775 	err = got_object_id_by_path(&tree_id, repo, base_commit_id,
4776 	    worktree->path_prefix);
4777 	if (err)
4778 		goto done;
4779 
4780 	err = delete_histedit_refs(worktree, repo);
4781 	if (err)
4782 		goto done;
4783 
4784 	err = get_fileindex_path(&fileindex_path, worktree);
4785 	if (err)
4786 		goto done;
4787 
4788 	crp_arg.revertible_paths = &revertible_paths;
4789 	crp_arg.worktree = worktree;
4790 	err = worktree_status(worktree, "", fileindex, repo,
4791 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4792 	if (err)
4793 		goto done;
4794 
4795 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4796 		err = revert_file(worktree, fileindex, pe->path,
4797 		    progress_cb, progress_arg, repo);
4798 		if (err)
4799 			goto sync;
4800 	}
4801 
4802 	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
4803 	    repo, progress_cb, progress_arg, NULL, NULL);
4804 sync:
4805 	sync_err = sync_fileindex(fileindex, fileindex_path);
4806 	if (sync_err && err == NULL)
4807 		err = sync_err;
4808 done:
4809 	got_ref_close(resolved);
4810 	free(tree_id);
4811 	free(fileindex_path);
4812 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4813 		free((char *)pe->path);
4814 	got_pathlist_free(&revertible_paths);
4815 
4816 	unlockerr = lock_worktree(worktree, LOCK_SH);
4817 	if (unlockerr && err == NULL)
4818 		err = unlockerr;
4819 	return err;
4820 }
4821 
4822 const struct got_error *
4823 got_worktree_histedit_complete(struct got_worktree *worktree,
4824     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4825     struct got_reference *edited_branch, struct got_repository *repo)
4826 {
4827 	const struct got_error *err, *unlockerr;
4828 	struct got_object_id *new_head_commit_id = NULL;
4829 	struct got_reference *resolved = NULL;
4830 
4831 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
4832 	if (err)
4833 		return err;
4834 
4835 	err = got_ref_open(&resolved, repo,
4836 	    got_ref_get_symref_target(edited_branch), 0);
4837 	if (err)
4838 		goto done;
4839 
4840 	err = got_ref_change_ref(resolved, new_head_commit_id);
4841 	if (err)
4842 		goto done;
4843 
4844 	err = got_ref_write(resolved, repo);
4845 	if (err)
4846 		goto done;
4847 
4848 	err = got_worktree_set_head_ref(worktree, resolved);
4849 	if (err)
4850 		goto done;
4851 
4852 	err = delete_histedit_refs(worktree, repo);
4853 done:
4854 	if (fileindex)
4855 		got_fileindex_free(fileindex);
4856 	free(new_head_commit_id);
4857 	unlockerr = lock_worktree(worktree, LOCK_SH);
4858 	if (unlockerr && err == NULL)
4859 		err = unlockerr;
4860 	return err;
4861 }
4862 
4863 const struct got_error *
4864 got_worktree_histedit_skip_commit(struct got_worktree *worktree,
4865     struct got_object_id *commit_id, struct got_repository *repo)
4866 {
4867 	const struct got_error *err;
4868 	char *commit_ref_name;
4869 
4870 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4871 	if (err)
4872 		return err;
4873 
4874 	err = store_commit_id(commit_ref_name, commit_id, repo);
4875 	if (err)
4876 		goto done;
4877 
4878 	err = delete_ref(commit_ref_name, repo);
4879 done:
4880 	free(commit_ref_name);
4881 	return err;
4882 }