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