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