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