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 const struct got_error *
1027 get_file_status(unsigned char *status, struct stat *sb,
1028     struct got_fileindex_entry *ie, const char *abspath,
1029     struct got_repository *repo)
1030 {
1031 	const struct got_error *err = NULL;
1032 	struct got_object_id id;
1033 	size_t hdrlen;
1034 	FILE *f = NULL;
1035 	uint8_t fbuf[8192];
1036 	struct got_blob_object *blob = NULL;
1037 	size_t flen, blen;
1038 
1039 	*status = GOT_STATUS_NO_CHANGE;
1040 
1041 	if (lstat(abspath, sb) == -1) {
1042 		if (errno == ENOENT) {
1043 			if (ie) {
1044 				if (got_fileindex_entry_has_file_on_disk(ie))
1045 					*status = GOT_STATUS_MISSING;
1046 				else
1047 					*status = GOT_STATUS_DELETE;
1048 				sb->st_mode =
1049 				    ((ie->mode >> GOT_FILEIDX_MODE_PERMS_SHIFT)
1050 				    & (S_IRWXU | S_IRWXG | S_IRWXO));
1051 			} else
1052 				sb->st_mode = GOT_DEFAULT_FILE_MODE;
1053 			return NULL;
1054 		}
1055 		return got_error_from_errno2("lstat", abspath);
1056 	}
1057 
1058 	if (!S_ISREG(sb->st_mode)) {
1059 		*status = GOT_STATUS_OBSTRUCTED;
1060 		return NULL;
1061 	}
1062 
1063 	if (ie == NULL)
1064 		return NULL;
1065 
1066 	if (!got_fileindex_entry_has_file_on_disk(ie)) {
1067 		*status = GOT_STATUS_DELETE;
1068 		return NULL;
1069 	} else if (!got_fileindex_entry_has_blob(ie)) {
1070 		*status = GOT_STATUS_ADD;
1071 		return NULL;
1072 	}
1073 
1074 	if (ie->ctime_sec == sb->st_ctime &&
1075 	    ie->ctime_nsec == sb->st_ctimensec &&
1076 	    ie->mtime_sec == sb->st_mtime &&
1077 	    ie->mtime_nsec == sb->st_mtimensec &&
1078 	    ie->size == (sb->st_size & 0xffffffff))
1079 		return NULL;
1080 
1081 	memcpy(id.sha1, ie->blob_sha1, sizeof(id.sha1));
1082 	err = got_object_open_as_blob(&blob, repo, &id, sizeof(fbuf));
1083 	if (err)
1084 		return err;
1085 
1086 	f = fopen(abspath, "r");
1087 	if (f == NULL) {
1088 		err = got_error_from_errno2("fopen", abspath);
1089 		goto done;
1090 	}
1091 	hdrlen = got_object_blob_get_hdrlen(blob);
1092 	for (;;) {
1093 		const uint8_t *bbuf = got_object_blob_get_read_buf(blob);
1094 		err = got_object_blob_read_block(&blen, blob);
1095 		if (err)
1096 			goto done;
1097 		/* Skip length of blob object header first time around. */
1098 		flen = fread(fbuf, 1, sizeof(fbuf) - hdrlen, f);
1099 		if (flen == 0 && ferror(f)) {
1100 			err = got_error_from_errno("fread");
1101 			goto done;
1102 		}
1103 		if (blen == 0) {
1104 			if (flen != 0)
1105 				*status = GOT_STATUS_MODIFY;
1106 			break;
1107 		} else if (flen == 0) {
1108 			if (blen != 0)
1109 				*status = GOT_STATUS_MODIFY;
1110 			break;
1111 		} else if (blen - hdrlen == flen) {
1112 			/* Skip blob object header first time around. */
1113 			if (memcmp(bbuf + hdrlen, fbuf, flen) != 0) {
1114 				*status = GOT_STATUS_MODIFY;
1115 				break;
1116 			}
1117 		} else {
1118 			*status = GOT_STATUS_MODIFY;
1119 			break;
1120 		}
1121 		hdrlen = 0;
1122 	}
1123 
1124 	if (*status == GOT_STATUS_MODIFY) {
1125 		rewind(f);
1126 		err = get_modified_file_content_status(status, f);
1127 	}
1128 done:
1129 	if (blob)
1130 		got_object_blob_close(blob);
1131 	if (f)
1132 		fclose(f);
1133 	return err;
1134 }
1135 
1136 static const struct got_error *
1137 update_blob(struct got_worktree *worktree,
1138     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
1139     struct got_tree_entry *te, const char *path,
1140     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1141     void *progress_arg)
1142 {
1143 	const struct got_error *err = NULL;
1144 	struct got_blob_object *blob = NULL;
1145 	char *ondisk_path;
1146 	unsigned char status = GOT_STATUS_NO_CHANGE;
1147 	struct stat sb;
1148 
1149 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
1150 		return got_error_from_errno("asprintf");
1151 
1152 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1153 	if (err)
1154 		goto done;
1155 
1156 	if (status == GOT_STATUS_OBSTRUCTED) {
1157 		err = (*progress_cb)(progress_arg, status, path);
1158 		goto done;
1159 	}
1160 
1161 	if (ie && status != GOT_STATUS_MISSING) {
1162 		if (got_fileindex_entry_has_commit(ie) &&
1163 		    memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
1164 		    SHA1_DIGEST_LENGTH) == 0) {
1165 			err = (*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
1166 			    path);
1167 			goto done;
1168 		}
1169 		if (got_fileindex_entry_has_blob(ie) &&
1170 		    memcmp(ie->blob_sha1, te->id->sha1,
1171 		    SHA1_DIGEST_LENGTH) == 0)
1172 			goto done;
1173 	}
1174 
1175 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
1176 	if (err)
1177 		goto done;
1178 
1179 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_ADD) {
1180 		int update_timestamps;
1181 		struct got_blob_object *blob2 = NULL;
1182 		if (got_fileindex_entry_has_blob(ie)) {
1183 			struct got_object_id id2;
1184 			memcpy(id2.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1185 			err = got_object_open_as_blob(&blob2, repo, &id2, 8192);
1186 			if (err)
1187 				goto done;
1188 		}
1189 		err = merge_blob(&update_timestamps, worktree, blob2,
1190 		    ondisk_path, path, sb.st_mode, blob,
1191 		    worktree->base_commit_id, repo,
1192 		    progress_cb, progress_arg);
1193 		if (blob2)
1194 			got_object_blob_close(blob2);
1195 		/*
1196 		 * Do not update timestamps of files with local changes.
1197 		 * Otherwise, a future status walk would treat them as
1198 		 * unmodified files again.
1199 		 */
1200 		err = got_fileindex_entry_update(ie, ondisk_path,
1201 		    blob->id.sha1, worktree->base_commit_id->sha1,
1202 		    update_timestamps);
1203 	} else if (status == GOT_STATUS_DELETE) {
1204 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, path);
1205 		if (err)
1206 			goto done;
1207 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1208 		    ondisk_path, path, blob, 0);
1209 		if (err)
1210 			goto done;
1211 	} else {
1212 		err = install_blob(worktree, ondisk_path, path, te->mode,
1213 		    sb.st_mode, blob, status == GOT_STATUS_MISSING, 0,
1214 		    repo, progress_cb, progress_arg);
1215 		if (err)
1216 			goto done;
1217 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1218 		    ondisk_path, path, blob, 1);
1219 		if (err)
1220 			goto done;
1221 	}
1222 	got_object_blob_close(blob);
1223 done:
1224 	free(ondisk_path);
1225 	return err;
1226 }
1227 
1228 static const struct got_error *
1229 remove_ondisk_file(const char *root_path, const char *path)
1230 {
1231 	const struct got_error *err = NULL;
1232 	char *ondisk_path = NULL;
1233 
1234 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
1235 		return got_error_from_errno("asprintf");
1236 
1237 	if (unlink(ondisk_path) == -1) {
1238 		if (errno != ENOENT)
1239 			err = got_error_from_errno2("unlink", ondisk_path);
1240 	} else {
1241 		char *parent = dirname(ondisk_path);
1242 		while (parent && strcmp(parent, root_path) != 0) {
1243 			if (rmdir(parent) == -1) {
1244 				if (errno != ENOTEMPTY)
1245 					err = got_error_from_errno2("rmdir",
1246 					    parent);
1247 				break;
1248 			}
1249 			parent = dirname(parent);
1250 		}
1251 	}
1252 	free(ondisk_path);
1253 	return err;
1254 }
1255 
1256 static const struct got_error *
1257 delete_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
1258     struct got_fileindex_entry *ie, struct got_repository *repo,
1259     got_worktree_checkout_cb progress_cb, void *progress_arg)
1260 {
1261 	const struct got_error *err = NULL;
1262 	unsigned char status;
1263 	struct stat sb;
1264 	char *ondisk_path;
1265 
1266 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, ie->path)
1267 	    == -1)
1268 		return got_error_from_errno("asprintf");
1269 
1270 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1271 	if (err)
1272 		return err;
1273 
1274 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_CONFLICT ||
1275 	    status == GOT_STATUS_ADD) {
1276 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, ie->path);
1277 		if (err)
1278 			return err;
1279 		/*
1280 		 * Preserve the working file and change the deleted blob's
1281 		 * entry into a schedule-add entry.
1282 		 */
1283 		err = got_fileindex_entry_update(ie, ondisk_path, NULL, NULL,
1284 		    0);
1285 		if (err)
1286 			return err;
1287 	} else {
1288 		err = (*progress_cb)(progress_arg, GOT_STATUS_DELETE, ie->path);
1289 		if (err)
1290 			return err;
1291 		if (status == GOT_STATUS_NO_CHANGE) {
1292 			err = remove_ondisk_file(worktree->root_path, ie->path);
1293 			if (err)
1294 				return err;
1295 		}
1296 		got_fileindex_entry_remove(fileindex, ie);
1297 	}
1298 
1299 	return err;
1300 }
1301 
1302 struct diff_cb_arg {
1303     struct got_fileindex *fileindex;
1304     struct got_worktree *worktree;
1305     struct got_repository *repo;
1306     got_worktree_checkout_cb progress_cb;
1307     void *progress_arg;
1308     got_worktree_cancel_cb cancel_cb;
1309     void *cancel_arg;
1310 };
1311 
1312 static const struct got_error *
1313 diff_old_new(void *arg, struct got_fileindex_entry *ie,
1314     struct got_tree_entry *te, const char *parent_path)
1315 {
1316 	struct diff_cb_arg *a = arg;
1317 
1318 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1319 		return got_error(GOT_ERR_CANCELLED);
1320 
1321 	return update_blob(a->worktree, a->fileindex, ie, te,
1322 	    ie->path, a->repo, a->progress_cb, a->progress_arg);
1323 }
1324 
1325 static const struct got_error *
1326 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1327 {
1328 	struct diff_cb_arg *a = arg;
1329 
1330 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1331 		return got_error(GOT_ERR_CANCELLED);
1332 
1333 	return delete_blob(a->worktree, a->fileindex, ie,
1334 	    a->repo, a->progress_cb, a->progress_arg);
1335 }
1336 
1337 static const struct got_error *
1338 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
1339 {
1340 	struct diff_cb_arg *a = arg;
1341 	const struct got_error *err;
1342 	char *path;
1343 
1344 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1345 		return got_error(GOT_ERR_CANCELLED);
1346 
1347 	if (asprintf(&path, "%s%s%s", parent_path,
1348 	    parent_path[0] ? "/" : "", te->name)
1349 	    == -1)
1350 		return got_error_from_errno("asprintf");
1351 
1352 	if (S_ISDIR(te->mode))
1353 		err = add_dir_on_disk(a->worktree, path);
1354 	else
1355 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
1356 		    a->repo, a->progress_cb, a->progress_arg);
1357 
1358 	free(path);
1359 	return err;
1360 }
1361 
1362 static const struct got_error *
1363 get_ref_name(char **refname, struct got_worktree *worktree, const char *prefix)
1364 {
1365 	const struct got_error *err = NULL;
1366 	char *uuidstr = NULL;
1367 	uint32_t uuid_status;
1368 
1369 	*refname = NULL;
1370 
1371 	uuid_to_string(&worktree->uuid, &uuidstr, &uuid_status);
1372 	if (uuid_status != uuid_s_ok)
1373 		return got_error_uuid(uuid_status);
1374 
1375 	if (asprintf(refname, "%s-%s", prefix, uuidstr)
1376 	    == -1) {
1377 		err = got_error_from_errno("asprintf");
1378 		*refname = NULL;
1379 	}
1380 	free(uuidstr);
1381 	return err;
1382 }
1383 
1384 const struct got_error *
1385 got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
1386 {
1387 	return get_ref_name(refname, worktree, GOT_WORKTREE_BASE_REF_PREFIX);
1388 }
1389 
1390 static const struct got_error *
1391 get_rebase_tmp_ref_name(char **refname, struct got_worktree *worktree)
1392 {
1393 	return get_ref_name(refname, worktree,
1394 	    GOT_WORKTREE_REBASE_TMP_REF_PREFIX);
1395 }
1396 
1397 static const struct got_error *
1398 get_newbase_symref_name(char **refname, struct got_worktree *worktree)
1399 {
1400 	return get_ref_name(refname, worktree, GOT_WORKTREE_NEWBASE_REF_PREFIX);
1401 }
1402 
1403 static const struct got_error *
1404 get_rebase_branch_symref_name(char **refname, struct got_worktree *worktree)
1405 {
1406 	return get_ref_name(refname, worktree,
1407 	    GOT_WORKTREE_REBASE_BRANCH_REF_PREFIX);
1408 }
1409 
1410 static const struct got_error *
1411 get_rebase_commit_ref_name(char **refname, struct got_worktree *worktree)
1412 {
1413 	return get_ref_name(refname, worktree,
1414 	    GOT_WORKTREE_REBASE_COMMIT_REF_PREFIX);
1415 }
1416 
1417 
1418 /*
1419  * Prevent Git's garbage collector from deleting our base commit by
1420  * setting a reference to our base commit's ID.
1421  */
1422 static const struct got_error *
1423 ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
1424 {
1425 	const struct got_error *err = NULL;
1426 	struct got_reference *ref = NULL;
1427 	char *refname;
1428 
1429 	err = got_worktree_get_base_ref_name(&refname, worktree);
1430 	if (err)
1431 		return err;
1432 
1433 	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
1434 	if (err)
1435 		goto done;
1436 
1437 	err = got_ref_write(ref, repo);
1438 done:
1439 	free(refname);
1440 	if (ref)
1441 		got_ref_close(ref);
1442 	return err;
1443 }
1444 
1445 static const struct got_error *
1446 open_fileindex(struct got_fileindex **fileindex, char **fileindex_path,
1447    struct got_worktree *worktree)
1448 {
1449 	const struct got_error *err = NULL;
1450 	FILE *index = NULL;
1451 
1452 	*fileindex_path = NULL;
1453 	*fileindex = got_fileindex_alloc();
1454 	if (*fileindex == NULL)
1455 		return got_error_from_errno("got_fileindex_alloc");
1456 
1457 	if (asprintf(fileindex_path, "%s/%s/%s", worktree->root_path,
1458 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1459 		err = got_error_from_errno("asprintf");
1460 		*fileindex_path = NULL;
1461 		goto done;
1462 	}
1463 
1464 	index = fopen(*fileindex_path, "rb");
1465 	if (index == NULL) {
1466 		if (errno != ENOENT)
1467 			err = got_error_from_errno2("fopen", *fileindex_path);
1468 	} else {
1469 		err = got_fileindex_read(*fileindex, index);
1470 		if (fclose(index) != 0 && err == NULL)
1471 			err = got_error_from_errno("fclose");
1472 	}
1473 done:
1474 	if (err) {
1475 		free(*fileindex_path);
1476 		*fileindex_path = NULL;
1477 		got_fileindex_free(*fileindex);
1478 		*fileindex = NULL;
1479 	}
1480 	return err;
1481 }
1482 
1483 struct bump_base_commit_id_arg {
1484 	struct got_object_id *base_commit_id;
1485 	const char *path;
1486 	size_t path_len;
1487 	const char *entry_name;
1488 	got_worktree_checkout_cb progress_cb;
1489 	void *progress_arg;
1490 };
1491 
1492 /* Bump base commit ID of all files within an updated part of the work tree. */
1493 static const struct got_error *
1494 bump_base_commit_id(void *arg, struct got_fileindex_entry *ie)
1495 {
1496 	const struct got_error *err;
1497 	struct bump_base_commit_id_arg *a = arg;
1498 
1499 	if (a->entry_name) {
1500 		if (strcmp(ie->path, a->path) != 0)
1501 			return NULL;
1502 	} else if (!got_path_is_child(ie->path, a->path, a->path_len))
1503 		return NULL;
1504 
1505 	if (memcmp(ie->commit_sha1, a->base_commit_id->sha1,
1506 	    SHA1_DIGEST_LENGTH) == 0)
1507 		return NULL;
1508 
1509 	if (a->progress_cb) {
1510 		err = (*a->progress_cb)(a->progress_arg, GOT_STATUS_BUMP_BASE,
1511 		    ie->path);
1512 		if (err)
1513 			return err;
1514 	}
1515 	memcpy(ie->commit_sha1, a->base_commit_id->sha1, SHA1_DIGEST_LENGTH);
1516 	return NULL;
1517 }
1518 
1519 static const struct got_error *
1520 sync_fileindex(struct got_fileindex *fileindex, const char *fileindex_path)
1521 {
1522 	const struct got_error *err = NULL;
1523 	char *new_fileindex_path = NULL;
1524 	FILE *new_index = NULL;
1525 
1526 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1527 	    fileindex_path);
1528 	if (err)
1529 		goto done;
1530 
1531 	err = got_fileindex_write(fileindex, new_index);
1532 	if (err)
1533 		goto done;
1534 
1535 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1536 		err = got_error_from_errno3("rename", new_fileindex_path,
1537 		    fileindex_path);
1538 		unlink(new_fileindex_path);
1539 	}
1540 done:
1541 	if (new_index)
1542 		fclose(new_index);
1543 	free(new_fileindex_path);
1544 	return err;
1545 }
1546 
1547 static const struct got_error *
1548 find_tree_entry_for_checkout(int *entry_type, char **tree_relpath,
1549     struct got_object_id **tree_id, const char *wt_relpath,
1550     struct got_worktree *worktree, struct got_repository *repo)
1551 {
1552 	const struct got_error *err = NULL;
1553 	struct got_object_id *id = NULL;
1554 	char *in_repo_path = NULL;
1555 	int is_root_wt = got_path_is_root_dir(worktree->path_prefix);
1556 
1557 	*entry_type = GOT_OBJ_TYPE_ANY;
1558 	*tree_relpath = NULL;
1559 	*tree_id = NULL;
1560 
1561 	if (wt_relpath[0] == '\0') {
1562 		/* Check out all files within the work tree. */
1563 		*entry_type = GOT_OBJ_TYPE_TREE;
1564 		*tree_relpath = strdup("");
1565 		if (*tree_relpath == NULL) {
1566 			err = got_error_from_errno("strdup");
1567 			goto done;
1568 		}
1569 		err = got_object_id_by_path(tree_id, repo,
1570 		    worktree->base_commit_id, worktree->path_prefix);
1571 		if (err)
1572 			goto done;
1573 		return NULL;
1574 	}
1575 
1576 	/* Check out a subset of files in the work tree. */
1577 
1578 	if (asprintf(&in_repo_path, "%s%s%s", worktree->path_prefix,
1579 	    is_root_wt ? "" : "/", wt_relpath) == -1) {
1580 		err = got_error_from_errno("asprintf");
1581 		goto done;
1582 	}
1583 
1584 	err = got_object_id_by_path(&id, repo, worktree->base_commit_id,
1585 	    in_repo_path);
1586 	if (err)
1587 		goto done;
1588 
1589 	free(in_repo_path);
1590 	in_repo_path = NULL;
1591 
1592 	err = got_object_get_type(entry_type, repo, id);
1593 	if (err)
1594 		goto done;
1595 
1596 	if (*entry_type == GOT_OBJ_TYPE_BLOB) {
1597 		/* Check out a single file. */
1598 		if (strchr(wt_relpath, '/')  == NULL) {
1599 			/* Check out a single file in work tree's root dir. */
1600 			in_repo_path = strdup(worktree->path_prefix);
1601 			if (in_repo_path == NULL) {
1602 				err = got_error_from_errno("strdup");
1603 				goto done;
1604 			}
1605 			*tree_relpath = strdup("");
1606 			if (*tree_relpath == NULL) {
1607 				err = got_error_from_errno("strdup");
1608 				goto done;
1609 			}
1610 		} else {
1611 			/* Check out a single file in a subdirectory. */
1612 			err = got_path_dirname(tree_relpath, wt_relpath);
1613 			if (err)
1614 				return err;
1615 			if (asprintf(&in_repo_path, "%s%s%s",
1616 			    worktree->path_prefix, is_root_wt ? "" : "/",
1617 			    *tree_relpath) == -1) {
1618 				err = got_error_from_errno("asprintf");
1619 				goto done;
1620 			}
1621 		}
1622 		err = got_object_id_by_path(tree_id, repo,
1623 		    worktree->base_commit_id, in_repo_path);
1624 	} else {
1625 		/* Check out all files within a subdirectory. */
1626 		*tree_id = got_object_id_dup(id);
1627 		if (*tree_id == NULL) {
1628 			err = got_error_from_errno("got_object_id_dup");
1629 			goto done;
1630 		}
1631 		*tree_relpath = strdup(wt_relpath);
1632 		if (*tree_relpath == NULL) {
1633 			err = got_error_from_errno("strdup");
1634 			goto done;
1635 		}
1636 	}
1637 done:
1638 	free(id);
1639 	free(in_repo_path);
1640 	if (err) {
1641 		*entry_type = GOT_OBJ_TYPE_ANY;
1642 		free(*tree_relpath);
1643 		*tree_relpath = NULL;
1644 		free(*tree_id);
1645 		*tree_id = NULL;
1646 	}
1647 	return err;
1648 }
1649 
1650 static const struct got_error *
1651 checkout_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
1652     const char *relpath, struct got_object_id *tree_id, const char *entry_name,
1653     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1654     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1655 {
1656 	const struct got_error *err = NULL;
1657 	struct got_commit_object *commit = NULL;
1658 	struct got_tree_object *tree = NULL;
1659 	struct got_fileindex_diff_tree_cb diff_cb;
1660 	struct diff_cb_arg arg;
1661 
1662 	err = ref_base_commit(worktree, repo);
1663 	if (err)
1664 		goto done;
1665 
1666 	err = got_object_open_as_commit(&commit, repo,
1667 	   worktree->base_commit_id);
1668 	if (err)
1669 		goto done;
1670 
1671 	err = got_object_open_as_tree(&tree, repo, tree_id);
1672 	if (err)
1673 		goto done;
1674 
1675 	if (entry_name &&
1676 	    got_object_tree_find_entry(tree, entry_name) == NULL) {
1677 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
1678 		goto done;
1679 	}
1680 
1681 	diff_cb.diff_old_new = diff_old_new;
1682 	diff_cb.diff_old = diff_old;
1683 	diff_cb.diff_new = diff_new;
1684 	arg.fileindex = fileindex;
1685 	arg.worktree = worktree;
1686 	arg.repo = repo;
1687 	arg.progress_cb = progress_cb;
1688 	arg.progress_arg = progress_arg;
1689 	arg.cancel_cb = cancel_cb;
1690 	arg.cancel_arg = cancel_arg;
1691 	err = got_fileindex_diff_tree(fileindex, tree, relpath,
1692 	    entry_name, repo, &diff_cb, &arg);
1693 done:
1694 	if (tree)
1695 		got_object_tree_close(tree);
1696 	if (commit)
1697 		got_object_commit_close(commit);
1698 	return err;
1699 }
1700 
1701 const struct got_error *
1702 got_worktree_checkout_files(struct got_worktree *worktree, const char *path,
1703     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1704     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1705 {
1706 	const struct got_error *err = NULL, *sync_err, *unlockerr;
1707 	struct got_commit_object *commit = NULL;
1708 	struct got_object_id *tree_id = NULL;
1709 	struct got_tree_object *tree = NULL;
1710 	struct got_fileindex *fileindex = NULL;
1711 	char *fileindex_path = NULL;
1712 	char *relpath = NULL, *entry_name = NULL;
1713 	int entry_type;
1714 
1715 	err = lock_worktree(worktree, LOCK_EX);
1716 	if (err)
1717 		return err;
1718 
1719 	err = find_tree_entry_for_checkout(&entry_type, &relpath, &tree_id,
1720 	    path, worktree, repo);
1721 	if (err)
1722 		goto done;
1723 
1724 	if (entry_type == GOT_OBJ_TYPE_BLOB) {
1725 		entry_name = basename(path);
1726 		if (entry_name == NULL) {
1727 			err = got_error_from_errno2("basename", path);
1728 			goto done;
1729 		}
1730 	}
1731 
1732 	/*
1733 	 * Read the file index.
1734 	 * Checking out files is supposed to be an idempotent operation.
1735 	 * If the on-disk file index is incomplete we will try to complete it.
1736 	 */
1737 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1738 	if (err)
1739 		goto done;
1740 
1741 	err = checkout_files(worktree, fileindex, relpath, tree_id, entry_name,
1742 	    repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
1743 	if (err == NULL) {
1744 		struct bump_base_commit_id_arg bbc_arg;
1745 		bbc_arg.base_commit_id = worktree->base_commit_id;
1746 		bbc_arg.entry_name = entry_name;
1747 		bbc_arg.path = path;
1748 		bbc_arg.path_len = strlen(path);
1749 		bbc_arg.progress_cb = progress_cb;
1750 		bbc_arg.progress_arg = progress_arg;
1751 		err = got_fileindex_for_each_entry_safe(fileindex,
1752 		    bump_base_commit_id, &bbc_arg);
1753 	}
1754 	sync_err = sync_fileindex(fileindex, fileindex_path);
1755 	if (sync_err && err == NULL)
1756 		err = sync_err;
1757 done:
1758 	free(fileindex_path);
1759 	free(relpath);
1760 	if (tree)
1761 		got_object_tree_close(tree);
1762 	if (commit)
1763 		got_object_commit_close(commit);
1764 	if (fileindex)
1765 		got_fileindex_free(fileindex);
1766 	unlockerr = lock_worktree(worktree, LOCK_SH);
1767 	if (unlockerr && err == NULL)
1768 		err = unlockerr;
1769 	return err;
1770 }
1771 
1772 struct merge_file_cb_arg {
1773     struct got_worktree *worktree;
1774     struct got_fileindex *fileindex;
1775     got_worktree_checkout_cb progress_cb;
1776     void *progress_arg;
1777     got_worktree_cancel_cb cancel_cb;
1778     void *cancel_arg;
1779     struct got_object_id *commit_id2;
1780 };
1781 
1782 static const struct got_error *
1783 merge_file_cb(void *arg, struct got_blob_object *blob1,
1784     struct got_blob_object *blob2, struct got_object_id *id1,
1785     struct got_object_id *id2, const char *path1, const char *path2,
1786     struct got_repository *repo)
1787 {
1788 	static const struct got_error *err = NULL;
1789 	struct merge_file_cb_arg *a = arg;
1790 	struct got_fileindex_entry *ie;
1791 	char *ondisk_path = NULL;
1792 	struct stat sb;
1793 	unsigned char status;
1794 	int local_changes_subsumed;
1795 
1796 	if (blob1 && blob2) {
1797 		ie = got_fileindex_entry_get(a->fileindex, path2);
1798 		if (ie == NULL)
1799 			return (*a->progress_cb)(a->progress_arg,
1800 			    GOT_STATUS_MISSING, path2);
1801 
1802 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1803 		    path2) == -1)
1804 			return got_error_from_errno("asprintf");
1805 
1806 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1807 		if (err)
1808 			goto done;
1809 
1810 		if (status == GOT_STATUS_DELETE) {
1811 			err = (*a->progress_cb)(a->progress_arg,
1812 			    GOT_STATUS_MERGE, path2);
1813 			goto done;
1814 		}
1815 		if (status != GOT_STATUS_NO_CHANGE &&
1816 		    status != GOT_STATUS_MODIFY &&
1817 		    status != GOT_STATUS_CONFLICT &&
1818 		    status != GOT_STATUS_ADD) {
1819 			err = (*a->progress_cb)(a->progress_arg, status, path2);
1820 			goto done;
1821 		}
1822 
1823 		err = merge_blob(&local_changes_subsumed, a->worktree, blob1,
1824 		    ondisk_path, path2, sb.st_mode, blob2, a->commit_id2, repo,
1825 		    a->progress_cb, a->progress_arg);
1826 	} else if (blob1) {
1827 		ie = got_fileindex_entry_get(a->fileindex, path1);
1828 		if (ie == NULL)
1829 			return (*a->progress_cb)(a->progress_arg,
1830 			    GOT_STATUS_MISSING, path2);
1831 
1832 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1833 		    path1) == -1)
1834 			return got_error_from_errno("asprintf");
1835 
1836 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1837 		if (err)
1838 			goto done;
1839 
1840 		switch (status) {
1841 		case GOT_STATUS_NO_CHANGE:
1842 			err = (*a->progress_cb)(a->progress_arg,
1843 			    GOT_STATUS_DELETE, path1);
1844 			if (err)
1845 				goto done;
1846 			err = remove_ondisk_file(a->worktree->root_path, path1);
1847 			if (err)
1848 				goto done;
1849 			if (ie)
1850 				got_fileindex_entry_mark_deleted_from_disk(ie);
1851 			break;
1852 		case GOT_STATUS_DELETE:
1853 		case GOT_STATUS_MISSING:
1854 			err = (*a->progress_cb)(a->progress_arg,
1855 			    GOT_STATUS_DELETE, path1);
1856 			if (err)
1857 				goto done;
1858 			if (ie)
1859 				got_fileindex_entry_mark_deleted_from_disk(ie);
1860 			break;
1861 		case GOT_STATUS_ADD:
1862 		case GOT_STATUS_MODIFY:
1863 		case GOT_STATUS_CONFLICT:
1864 			err = (*a->progress_cb)(a->progress_arg,
1865 			    GOT_STATUS_CANNOT_DELETE, path1);
1866 			if (err)
1867 				goto done;
1868 			break;
1869 		case GOT_STATUS_OBSTRUCTED:
1870 			err = (*a->progress_cb)(a->progress_arg, status, path1);
1871 			if (err)
1872 				goto done;
1873 			break;
1874 		default:
1875 			break;
1876 		}
1877 	} else if (blob2) {
1878 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1879 		    path2) == -1)
1880 			return got_error_from_errno("asprintf");
1881 		ie = got_fileindex_entry_get(a->fileindex, path2);
1882 		if (ie) {
1883 			err = get_file_status(&status, &sb, ie, ondisk_path,
1884 			    repo);
1885 			if (err)
1886 				goto done;
1887 			if (status != GOT_STATUS_NO_CHANGE &&
1888 			    status != GOT_STATUS_MODIFY &&
1889 			    status != GOT_STATUS_CONFLICT &&
1890 			    status != GOT_STATUS_ADD) {
1891 				err = (*a->progress_cb)(a->progress_arg,
1892 				    status, path2);
1893 				goto done;
1894 			}
1895 			err = merge_blob(&local_changes_subsumed, a->worktree,
1896 			    NULL, ondisk_path, path2, sb.st_mode, blob2,
1897 			    a->commit_id2, repo,
1898 			    a->progress_cb, a->progress_arg);
1899 			if (status == GOT_STATUS_DELETE) {
1900 				err = update_blob_fileindex_entry(a->worktree,
1901 				    a->fileindex, ie, ondisk_path, ie->path,
1902 				    blob2, 0);
1903 				if (err)
1904 					goto done;
1905 			}
1906 		} else {
1907 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1908 			err = install_blob(a->worktree, ondisk_path, path2,
1909 			    /* XXX get this from parent tree! */
1910 			    GOT_DEFAULT_FILE_MODE,
1911 			    sb.st_mode, blob2, 0, 0, repo,
1912 			    a->progress_cb, a->progress_arg);
1913 			if (err)
1914 				goto done;
1915 			err = got_fileindex_entry_alloc(&ie,
1916 			    ondisk_path, path2, NULL, NULL);
1917 			if (err)
1918 				goto done;
1919 			err = got_fileindex_entry_add(a->fileindex, ie);
1920 			if (err) {
1921 				got_fileindex_entry_free(ie);
1922 				goto done;
1923 			}
1924 		}
1925 	}
1926 done:
1927 	free(ondisk_path);
1928 	return err;
1929 }
1930 
1931 struct check_merge_ok_arg {
1932 	struct got_worktree *worktree;
1933 	struct got_repository *repo;
1934 };
1935 
1936 static const struct got_error *
1937 check_merge_ok(void *arg, struct got_fileindex_entry *ie)
1938 {
1939 	const struct got_error *err = NULL;
1940 	struct check_merge_ok_arg *a = arg;
1941 	unsigned char status;
1942 	struct stat sb;
1943 	char *ondisk_path;
1944 
1945 	/* Reject merges into a work tree with mixed base commits. */
1946 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
1947 	    SHA1_DIGEST_LENGTH))
1948 		return got_error(GOT_ERR_MIXED_COMMITS);
1949 
1950 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
1951 	    == -1)
1952 		return got_error_from_errno("asprintf");
1953 
1954 	/* Reject merges into a work tree with conflicted files. */
1955 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
1956 	if (err)
1957 		return err;
1958 	if (status == GOT_STATUS_CONFLICT)
1959 		return got_error(GOT_ERR_CONFLICTS);
1960 
1961 	return NULL;
1962 }
1963 
1964 static const struct got_error *
1965 merge_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
1966     const char *fileindex_path, struct got_object_id *commit_id1,
1967     struct got_object_id *commit_id2, struct got_repository *repo,
1968     got_worktree_checkout_cb progress_cb, void *progress_arg,
1969     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1970 {
1971 	const struct got_error *err = NULL, *sync_err;
1972 	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
1973 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1974 	struct merge_file_cb_arg arg;
1975 
1976 	if (commit_id1) {
1977 		err = got_object_id_by_path(&tree_id1, repo, commit_id1,
1978 		    worktree->path_prefix);
1979 		if (err)
1980 			goto done;
1981 
1982 		err = got_object_open_as_tree(&tree1, repo, tree_id1);
1983 		if (err)
1984 			goto done;
1985 	}
1986 
1987 	err = got_object_id_by_path(&tree_id2, repo, commit_id2,
1988 	    worktree->path_prefix);
1989 	if (err)
1990 		goto done;
1991 
1992 	err = got_object_open_as_tree(&tree2, repo, tree_id2);
1993 	if (err)
1994 		goto done;
1995 
1996 	arg.worktree = worktree;
1997 	arg.fileindex = fileindex;
1998 	arg.progress_cb = progress_cb;
1999 	arg.progress_arg = progress_arg;
2000 	arg.cancel_cb = cancel_cb;
2001 	arg.cancel_arg = cancel_arg;
2002 	arg.commit_id2 = commit_id2;
2003 	err = got_diff_tree(tree1, tree2, "", "", repo, merge_file_cb, &arg);
2004 	sync_err = sync_fileindex(fileindex, fileindex_path);
2005 	if (sync_err && err == NULL)
2006 		err = sync_err;
2007 done:
2008 	if (tree1)
2009 		got_object_tree_close(tree1);
2010 	if (tree2)
2011 		got_object_tree_close(tree2);
2012 	return err;
2013 }
2014 
2015 const struct got_error *
2016 got_worktree_merge_files(struct got_worktree *worktree,
2017     struct got_object_id *commit_id1, struct got_object_id *commit_id2,
2018     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
2019     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2020 {
2021 	const struct got_error *err, *unlockerr;
2022 	char *fileindex_path = NULL;
2023 	struct got_fileindex *fileindex = NULL;
2024 	struct check_merge_ok_arg mok_arg;
2025 
2026 	err = lock_worktree(worktree, LOCK_EX);
2027 	if (err)
2028 		return err;
2029 
2030 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2031 	if (err)
2032 		goto done;
2033 
2034 	mok_arg.worktree = worktree;
2035 	mok_arg.repo = repo;
2036 	err = got_fileindex_for_each_entry_safe(fileindex, check_merge_ok,
2037 	    &mok_arg);
2038 	if (err)
2039 		goto done;
2040 
2041 	err = merge_files(worktree, fileindex, fileindex_path, commit_id1,
2042 	    commit_id2, repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
2043 done:
2044 	if (fileindex)
2045 		got_fileindex_free(fileindex);
2046 	free(fileindex_path);
2047 	unlockerr = lock_worktree(worktree, LOCK_SH);
2048 	if (unlockerr && err == NULL)
2049 		err = unlockerr;
2050 	return err;
2051 }
2052 
2053 struct diff_dir_cb_arg {
2054     struct got_fileindex *fileindex;
2055     struct got_worktree *worktree;
2056     const char *status_path;
2057     size_t status_path_len;
2058     struct got_repository *repo;
2059     got_worktree_status_cb status_cb;
2060     void *status_arg;
2061     got_worktree_cancel_cb cancel_cb;
2062     void *cancel_arg;
2063 };
2064 
2065 static const struct got_error *
2066 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
2067     got_worktree_status_cb status_cb, void *status_arg,
2068     struct got_repository *repo)
2069 {
2070 	const struct got_error *err = NULL;
2071 	unsigned char status = GOT_STATUS_NO_CHANGE;
2072 	struct stat sb;
2073 	struct got_object_id blob_id, commit_id;
2074 
2075 	err = get_file_status(&status, &sb, ie, abspath, repo);
2076 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
2077 		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2078 		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2079 		err = (*status_cb)(status_arg, status, ie->path, &blob_id,
2080 		    &commit_id);
2081 	}
2082 	return err;
2083 }
2084 
2085 static const struct got_error *
2086 status_old_new(void *arg, struct got_fileindex_entry *ie,
2087     struct dirent *de, const char *parent_path)
2088 {
2089 	const struct got_error *err = NULL;
2090 	struct diff_dir_cb_arg *a = arg;
2091 	char *abspath;
2092 
2093 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2094 		return got_error(GOT_ERR_CANCELLED);
2095 
2096 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
2097 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
2098 		return NULL;
2099 
2100 	if (parent_path[0]) {
2101 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
2102 		    parent_path, de->d_name) == -1)
2103 			return got_error_from_errno("asprintf");
2104 	} else {
2105 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
2106 		    de->d_name) == -1)
2107 			return got_error_from_errno("asprintf");
2108 	}
2109 
2110 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
2111 	    a->repo);
2112 	free(abspath);
2113 	return err;
2114 }
2115 
2116 static const struct got_error *
2117 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
2118 {
2119 	struct diff_dir_cb_arg *a = arg;
2120 	struct got_object_id blob_id, commit_id;
2121 	unsigned char status;
2122 
2123 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2124 		return got_error(GOT_ERR_CANCELLED);
2125 
2126 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2127 		return NULL;
2128 
2129 	memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2130 	memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2131 	if (got_fileindex_entry_has_file_on_disk(ie))
2132 		status = GOT_STATUS_MISSING;
2133 	else
2134 		status = GOT_STATUS_DELETE;
2135 	return (*a->status_cb)(a->status_arg, status, ie->path, &blob_id,
2136 	    &commit_id);
2137 }
2138 
2139 static const struct got_error *
2140 status_new(void *arg, struct dirent *de, const char *parent_path)
2141 {
2142 	const struct got_error *err = NULL;
2143 	struct diff_dir_cb_arg *a = arg;
2144 	char *path = NULL;
2145 
2146 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2147 		return got_error(GOT_ERR_CANCELLED);
2148 
2149 	if (de->d_type == DT_DIR)
2150 		return NULL;
2151 
2152 	/* XXX ignore symlinks for now */
2153 	if (de->d_type == DT_LNK)
2154 		return NULL;
2155 
2156 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2157 		return NULL;
2158 
2159 	if (parent_path[0]) {
2160 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
2161 			return got_error_from_errno("asprintf");
2162 	} else {
2163 		path = de->d_name;
2164 	}
2165 
2166 	err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED, path,
2167 	    NULL, NULL);
2168 	if (parent_path[0])
2169 		free(path);
2170 	return err;
2171 }
2172 
2173 static const struct got_error *
2174 worktree_status(struct got_worktree *worktree, const char *path,
2175     struct got_fileindex *fileindex, struct got_repository *repo,
2176     got_worktree_status_cb status_cb, void *status_arg,
2177     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2178 {
2179 	const struct got_error *err = NULL;
2180 	DIR *workdir = NULL;
2181 	struct got_fileindex_diff_dir_cb fdiff_cb;
2182 	struct diff_dir_cb_arg arg;
2183 	char *ondisk_path = NULL;
2184 
2185 	if (asprintf(&ondisk_path, "%s%s%s",
2186 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
2187 		err = got_error_from_errno("asprintf");
2188 		goto done;
2189 	}
2190 	workdir = opendir(ondisk_path);
2191 	if (workdir == NULL) {
2192 		if (errno == ENOTDIR || errno == ENOENT) {
2193 			struct got_fileindex_entry *ie;
2194 			ie = got_fileindex_entry_get(fileindex, path);
2195 			if (ie == NULL) {
2196 				err = got_error(GOT_ERR_BAD_PATH);
2197 				goto done;
2198 			}
2199 			err = report_file_status(ie, ondisk_path,
2200 			    status_cb, status_arg, repo);
2201 			goto done;
2202 		} else {
2203 			err = got_error_from_errno2("opendir", ondisk_path);
2204 			goto done;
2205 		}
2206 	}
2207 	fdiff_cb.diff_old_new = status_old_new;
2208 	fdiff_cb.diff_old = status_old;
2209 	fdiff_cb.diff_new = status_new;
2210 	arg.fileindex = fileindex;
2211 	arg.worktree = worktree;
2212 	arg.status_path = path;
2213 	arg.status_path_len = strlen(path);
2214 	arg.repo = repo;
2215 	arg.status_cb = status_cb;
2216 	arg.status_arg = status_arg;
2217 	arg.cancel_cb = cancel_cb;
2218 	arg.cancel_arg = cancel_arg;
2219 	err = got_fileindex_diff_dir(fileindex, workdir, worktree->root_path,
2220 	    path, repo, &fdiff_cb, &arg);
2221 done:
2222 	if (workdir)
2223 		closedir(workdir);
2224 	free(ondisk_path);
2225 	return err;
2226 }
2227 
2228 const struct got_error *
2229 got_worktree_status(struct got_worktree *worktree, const char *path,
2230     struct got_repository *repo, got_worktree_status_cb status_cb,
2231     void *status_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2232 {
2233 	const struct got_error *err = NULL;
2234 	char *fileindex_path = NULL;
2235 	struct got_fileindex *fileindex = NULL;
2236 
2237 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2238 	if (err)
2239 		return err;
2240 
2241 	err = worktree_status(worktree, path, fileindex, repo,
2242 	    status_cb, status_arg, cancel_cb, cancel_arg);
2243 	free(fileindex_path);
2244 	got_fileindex_free(fileindex);
2245 	return err;
2246 }
2247 
2248 const struct got_error *
2249 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
2250     const char *arg)
2251 {
2252 	const struct got_error *err = NULL;
2253 	char *resolved, *path = NULL;
2254 	size_t len;
2255 
2256 	*wt_path = NULL;
2257 
2258 	resolved = realpath(arg, NULL);
2259 	if (resolved == NULL)
2260 		return got_error_from_errno2("realpath", arg);
2261 
2262 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
2263 	    strlen(got_worktree_get_root_path(worktree)))) {
2264 		err = got_error(GOT_ERR_BAD_PATH);
2265 		goto done;
2266 	}
2267 
2268 	if (strlen(resolved) > strlen(got_worktree_get_root_path(worktree))) {
2269 		err = got_path_skip_common_ancestor(&path,
2270 		    got_worktree_get_root_path(worktree), resolved);
2271 		if (err)
2272 			goto done;
2273 	} else {
2274 		path = strdup("");
2275 		if (path == NULL) {
2276 			err = got_error_from_errno("strdup");
2277 			goto done;
2278 		}
2279 	}
2280 
2281 	/* XXX status walk can't deal with trailing slash! */
2282 	len = strlen(path);
2283 	while (path[len - 1] == '/') {
2284 		path[len - 1] = '\0';
2285 		len--;
2286 	}
2287 done:
2288 	free(resolved);
2289 	if (err == NULL)
2290 		*wt_path = path;
2291 	else
2292 		free(path);
2293 	return err;
2294 }
2295 
2296 static const struct got_error *
2297 schedule_addition(const char *ondisk_path, struct got_fileindex *fileindex,
2298     const char *relpath, got_worktree_status_cb status_cb, void *status_arg,
2299     struct got_repository *repo)
2300 {
2301 	const struct got_error *err = NULL;
2302 	struct got_fileindex_entry *ie;
2303 
2304 	/* Re-adding an existing entry is a no-op. */
2305 	if (got_fileindex_entry_get(fileindex, relpath) != NULL)
2306 		return NULL;
2307 
2308 	err = got_fileindex_entry_alloc(&ie, ondisk_path, relpath, NULL, NULL);
2309 	if (err)
2310 		return err;
2311 
2312 	err = got_fileindex_entry_add(fileindex, ie);
2313 	if (err) {
2314 		got_fileindex_entry_free(ie);
2315 		return err;
2316 	}
2317 
2318 	return report_file_status(ie, relpath, status_cb, status_arg, repo);
2319 }
2320 
2321 const struct got_error *
2322 got_worktree_schedule_add(struct got_worktree *worktree,
2323     struct got_pathlist_head *ondisk_paths,
2324     got_worktree_status_cb status_cb, void *status_arg,
2325     struct got_repository *repo)
2326 {
2327 	struct got_fileindex *fileindex = NULL;
2328 	char *fileindex_path = NULL;
2329 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2330 	struct got_pathlist_entry *pe;
2331 
2332 	err = lock_worktree(worktree, LOCK_EX);
2333 	if (err)
2334 		return err;
2335 
2336 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2337 	if (err)
2338 		goto done;
2339 
2340 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2341 		char *relpath;
2342 		err = got_path_skip_common_ancestor(&relpath,
2343 		    got_worktree_get_root_path(worktree), pe->path);
2344 		if (err)
2345 			break;
2346 		err = schedule_addition(pe->path, fileindex, relpath,
2347 		    status_cb, status_arg, repo);
2348 		free(relpath);
2349 		if (err)
2350 			break;
2351 	}
2352 	sync_err = sync_fileindex(fileindex, fileindex_path);
2353 	if (sync_err && err == NULL)
2354 		err = sync_err;
2355 done:
2356 	free(fileindex_path);
2357 	if (fileindex)
2358 		got_fileindex_free(fileindex);
2359 	unlockerr = lock_worktree(worktree, LOCK_SH);
2360 	if (unlockerr && err == NULL)
2361 		err = unlockerr;
2362 	return err;
2363 }
2364 
2365 static const struct got_error *
2366 schedule_for_deletion(const char *ondisk_path, struct got_fileindex *fileindex,
2367     const char *relpath, int delete_local_mods,
2368     got_worktree_status_cb status_cb, void *status_arg,
2369     struct got_repository *repo)
2370 {
2371 	const struct got_error *err = NULL;
2372 	struct got_fileindex_entry *ie = NULL;
2373 	unsigned char status;
2374 	struct stat sb;
2375 
2376 	ie = got_fileindex_entry_get(fileindex, relpath);
2377 	if (ie == NULL)
2378 		return got_error(GOT_ERR_BAD_PATH);
2379 
2380 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2381 	if (err)
2382 		return err;
2383 
2384 	if (status != GOT_STATUS_NO_CHANGE) {
2385 		if (status == GOT_STATUS_DELETE)
2386 			return got_error_set_errno(ENOENT, ondisk_path);
2387 		if (status != GOT_STATUS_MODIFY)
2388 			return got_error(GOT_ERR_FILE_STATUS);
2389 		if (!delete_local_mods)
2390 			return got_error(GOT_ERR_FILE_MODIFIED);
2391 	}
2392 
2393 	if (unlink(ondisk_path) != 0)
2394 		return got_error_from_errno2("unlink", ondisk_path);
2395 
2396 	got_fileindex_entry_mark_deleted_from_disk(ie);
2397 	return report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2398 }
2399 
2400 const struct got_error *
2401 got_worktree_schedule_delete(struct got_worktree *worktree,
2402     struct got_pathlist_head *ondisk_paths, int delete_local_mods,
2403     got_worktree_status_cb status_cb, void *status_arg,
2404     struct got_repository *repo)
2405 {
2406 	struct got_fileindex *fileindex = NULL;
2407 	char *fileindex_path = NULL;
2408 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2409 	struct got_pathlist_entry *pe;
2410 
2411 	err = lock_worktree(worktree, LOCK_EX);
2412 	if (err)
2413 		return err;
2414 
2415 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2416 	if (err)
2417 		goto done;
2418 
2419 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2420 		char *relpath;
2421 		err = got_path_skip_common_ancestor(&relpath,
2422 		    got_worktree_get_root_path(worktree), pe->path);
2423 		if (err)
2424 			break;
2425 		err = schedule_for_deletion(pe->path, fileindex, relpath,
2426 		    delete_local_mods, status_cb, status_arg, repo);
2427 		free(relpath);
2428 		if (err)
2429 			break;
2430 	}
2431 	sync_err = sync_fileindex(fileindex, fileindex_path);
2432 	if (sync_err && err == NULL)
2433 		err = sync_err;
2434 done:
2435 	free(fileindex_path);
2436 	if (fileindex)
2437 		got_fileindex_free(fileindex);
2438 	unlockerr = lock_worktree(worktree, LOCK_SH);
2439 	if (unlockerr && err == NULL)
2440 		err = unlockerr;
2441 	return err;
2442 }
2443 
2444 static const struct got_error *
2445 revert_file(struct got_worktree *worktree, struct got_fileindex *fileindex,
2446     const char *ondisk_path,
2447     got_worktree_checkout_cb progress_cb, void *progress_arg,
2448     struct got_repository *repo)
2449 {
2450 	const struct got_error *err = NULL;
2451 	char *relpath = NULL, *parent_path = NULL;
2452 	struct got_fileindex_entry *ie;
2453 	struct got_tree_object *tree = NULL;
2454 	struct got_object_id *tree_id = NULL;
2455 	const struct got_tree_entry *te;
2456 	char *tree_path = NULL, *te_name;
2457 	struct got_blob_object *blob = NULL;
2458 	unsigned char status;
2459 	struct stat sb;
2460 
2461 	err = got_path_skip_common_ancestor(&relpath,
2462 	    got_worktree_get_root_path(worktree), ondisk_path);
2463 	if (err)
2464 		goto done;
2465 
2466 	ie = got_fileindex_entry_get(fileindex, relpath);
2467 	if (ie == NULL) {
2468 		err = got_error(GOT_ERR_BAD_PATH);
2469 		goto done;
2470 	}
2471 
2472 	/* Construct in-repository path of tree which contains this blob. */
2473 	err = got_path_dirname(&parent_path, ie->path);
2474 	if (err) {
2475 		if (err->code != GOT_ERR_BAD_PATH)
2476 			goto done;
2477 		parent_path = strdup("/");
2478 		if (parent_path == NULL) {
2479 			err = got_error_from_errno("strdup");
2480 			goto done;
2481 		}
2482 	}
2483 	if (got_path_is_root_dir(worktree->path_prefix)) {
2484 		tree_path = strdup(parent_path);
2485 		if (tree_path == NULL) {
2486 			err = got_error_from_errno("strdup");
2487 			goto done;
2488 		}
2489 	} else {
2490 		if (got_path_is_root_dir(parent_path)) {
2491 			tree_path = strdup(worktree->path_prefix);
2492 			if (tree_path == NULL) {
2493 				err = got_error_from_errno("strdup");
2494 				goto done;
2495 			}
2496 		} else {
2497 			if (asprintf(&tree_path, "%s/%s",
2498 			    worktree->path_prefix, parent_path) == -1) {
2499 				err = got_error_from_errno("asprintf");
2500 				goto done;
2501 			}
2502 		}
2503 	}
2504 
2505 	err = got_object_id_by_path(&tree_id, repo, worktree->base_commit_id,
2506 	    tree_path);
2507 	if (err)
2508 		goto done;
2509 
2510 	err = got_object_open_as_tree(&tree, repo, tree_id);
2511 	if (err)
2512 		goto done;
2513 
2514 	te_name = basename(ie->path);
2515 	if (te_name == NULL) {
2516 		err = got_error_from_errno2("basename", ie->path);
2517 		goto done;
2518 	}
2519 
2520 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2521 	if (err)
2522 		goto done;
2523 
2524 	te = got_object_tree_find_entry(tree, te_name);
2525 	if (te == NULL && status != GOT_STATUS_ADD) {
2526 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
2527 		goto done;
2528 	}
2529 
2530 	switch (status) {
2531 	case GOT_STATUS_ADD:
2532 		err = (*progress_cb)(progress_arg, GOT_STATUS_REVERT, ie->path);
2533 		if (err)
2534 			goto done;
2535 		got_fileindex_entry_remove(fileindex, ie);
2536 		break;
2537 	case GOT_STATUS_DELETE:
2538 	case GOT_STATUS_MODIFY:
2539 	case GOT_STATUS_CONFLICT:
2540 	case GOT_STATUS_MISSING: {
2541 		struct got_object_id id;
2542 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2543 		err = got_object_open_as_blob(&blob, repo, &id, 8192);
2544 		if (err)
2545 			goto done;
2546 		err = install_blob(worktree, ondisk_path, ie->path,
2547 		    te->mode, sb.st_mode, blob, 0, 1, repo, progress_cb,
2548 		    progress_arg);
2549 		if (err)
2550 			goto done;
2551 		if (status == GOT_STATUS_DELETE) {
2552 			err = update_blob_fileindex_entry(worktree,
2553 			    fileindex, ie, ondisk_path, ie->path, blob, 1);
2554 			if (err)
2555 				goto done;
2556 		}
2557 		break;
2558 	}
2559 	default:
2560 			goto done;
2561 	}
2562 done:
2563 	free(relpath);
2564 	free(parent_path);
2565 	free(tree_path);
2566 	if (blob)
2567 		got_object_blob_close(blob);
2568 	if (tree)
2569 		got_object_tree_close(tree);
2570 	free(tree_id);
2571 	return err;
2572 }
2573 
2574 const struct got_error *
2575 got_worktree_revert(struct got_worktree *worktree,
2576     struct got_pathlist_head *ondisk_paths,
2577     got_worktree_checkout_cb progress_cb, void *progress_arg,
2578     struct got_repository *repo)
2579 {
2580 	struct got_fileindex *fileindex = NULL;
2581 	char *fileindex_path = NULL;
2582 	const struct got_error *err = NULL, *unlockerr = NULL;
2583 	const struct got_error *sync_err = NULL;
2584 	struct got_pathlist_entry *pe;
2585 
2586 	err = lock_worktree(worktree, LOCK_EX);
2587 	if (err)
2588 		return err;
2589 
2590 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2591 	if (err)
2592 		goto done;
2593 
2594 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2595 		err = revert_file(worktree, fileindex, pe->path,
2596 		    progress_cb, progress_arg, repo);
2597 		if (err)
2598 			break;
2599 	}
2600 	sync_err = sync_fileindex(fileindex, fileindex_path);
2601 	if (sync_err && err == NULL)
2602 		err = sync_err;
2603 done:
2604 	free(fileindex_path);
2605 	if (fileindex)
2606 		got_fileindex_free(fileindex);
2607 	unlockerr = lock_worktree(worktree, LOCK_SH);
2608 	if (unlockerr && err == NULL)
2609 		err = unlockerr;
2610 	return err;
2611 }
2612 
2613 static void
2614 free_commitable(struct got_commitable *ct)
2615 {
2616 	free(ct->path);
2617 	free(ct->in_repo_path);
2618 	free(ct->ondisk_path);
2619 	free(ct->blob_id);
2620 	free(ct->base_blob_id);
2621 	free(ct->base_commit_id);
2622 	free(ct);
2623 }
2624 
2625 struct collect_commitables_arg {
2626 	struct got_pathlist_head *commitable_paths;
2627 	struct got_repository *repo;
2628 	struct got_worktree *worktree;
2629 };
2630 
2631 static const struct got_error *
2632 collect_commitables(void *arg, unsigned char status, const char *relpath,
2633     struct got_object_id *blob_id, struct got_object_id *commit_id)
2634 {
2635 	struct collect_commitables_arg *a = arg;
2636 	const struct got_error *err = NULL;
2637 	struct got_commitable *ct = NULL;
2638 	struct got_pathlist_entry *new = NULL;
2639 	char *parent_path = NULL, *path = NULL;
2640 	struct stat sb;
2641 
2642 	if (status == GOT_STATUS_CONFLICT)
2643 		return got_error(GOT_ERR_COMMIT_CONFLICT);
2644 
2645 	if (status != GOT_STATUS_MODIFY && status != GOT_STATUS_ADD &&
2646 	    status != GOT_STATUS_DELETE)
2647 		return NULL;
2648 
2649 	if (asprintf(&path, "/%s", relpath) == -1) {
2650 		err = got_error_from_errno("asprintf");
2651 		goto done;
2652 	}
2653 	if (strcmp(path, "/") == 0) {
2654 		parent_path = strdup("");
2655 		if (parent_path == NULL)
2656 			return got_error_from_errno("strdup");
2657 	} else {
2658 		err = got_path_dirname(&parent_path, path);
2659 		if (err)
2660 			return err;
2661 	}
2662 
2663 	ct = calloc(1, sizeof(*ct));
2664 	if (ct == NULL) {
2665 		err = got_error_from_errno("calloc");
2666 		goto done;
2667 	}
2668 
2669 	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
2670 	    relpath) == -1) {
2671 		err = got_error_from_errno("asprintf");
2672 		goto done;
2673 	}
2674 	if (status == GOT_STATUS_DELETE) {
2675 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
2676 	} else {
2677 		if (lstat(ct->ondisk_path, &sb) != 0) {
2678 			err = got_error_from_errno2("lstat", ct->ondisk_path);
2679 			goto done;
2680 		}
2681 		ct->mode = sb.st_mode;
2682 	}
2683 
2684 	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
2685 	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
2686 	    relpath) == -1) {
2687 		err = got_error_from_errno("asprintf");
2688 		goto done;
2689 	}
2690 
2691 	ct->status = status;
2692 	ct->blob_id = NULL; /* will be filled in when blob gets created */
2693 	if (ct->status != GOT_STATUS_ADD) {
2694 		ct->base_blob_id = got_object_id_dup(blob_id);
2695 		if (ct->base_blob_id == NULL) {
2696 			err = got_error_from_errno("got_object_id_dup");
2697 			goto done;
2698 		}
2699 		ct->base_commit_id = got_object_id_dup(commit_id);
2700 		if (ct->base_commit_id == NULL) {
2701 			err = got_error_from_errno("got_object_id_dup");
2702 			goto done;
2703 		}
2704 	}
2705 	ct->path = strdup(path);
2706 	if (ct->path == NULL) {
2707 		err = got_error_from_errno("strdup");
2708 		goto done;
2709 	}
2710 	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
2711 done:
2712 	if (ct && (err || new == NULL))
2713 		free_commitable(ct);
2714 	free(parent_path);
2715 	free(path);
2716 	return err;
2717 }
2718 
2719 static const struct got_error *write_tree(struct got_object_id **,
2720     struct got_tree_object *, const char *, struct got_pathlist_head *,
2721     got_worktree_status_cb status_cb, void *status_arg,
2722     struct got_repository *);
2723 
2724 static const struct got_error *
2725 write_subtree(struct got_object_id **new_subtree_id,
2726     struct got_tree_entry *te, const char *parent_path,
2727     struct got_pathlist_head *commitable_paths,
2728     got_worktree_status_cb status_cb, void *status_arg,
2729     struct got_repository *repo)
2730 {
2731 	const struct got_error *err = NULL;
2732 	struct got_tree_object *subtree;
2733 	char *subpath;
2734 
2735 	if (asprintf(&subpath, "%s%s%s", parent_path,
2736 	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
2737 		return got_error_from_errno("asprintf");
2738 
2739 	err = got_object_open_as_tree(&subtree, repo, te->id);
2740 	if (err)
2741 		return err;
2742 
2743 	err = write_tree(new_subtree_id, subtree, subpath, commitable_paths,
2744 	    status_cb, status_arg, repo);
2745 	got_object_tree_close(subtree);
2746 	free(subpath);
2747 	return err;
2748 }
2749 
2750 static const struct got_error *
2751 match_ct_parent_path(int *match, struct got_commitable *ct, const char *path)
2752 {
2753 	const struct got_error *err = NULL;
2754 	char *ct_parent_path = NULL;
2755 
2756 	*match = 0;
2757 
2758 	if (strchr(ct->path, '/') == NULL) {
2759 		*match = got_path_is_root_dir(path);
2760 		return NULL;
2761 	}
2762 
2763 	err = got_path_dirname(&ct_parent_path, ct->path);
2764 	if (err)
2765 		return err;
2766 	*match = (strcmp(path, ct_parent_path) == 0);
2767 	free(ct_parent_path);
2768 	return err;
2769 }
2770 
2771 static mode_t
2772 get_ct_file_mode(struct got_commitable *ct)
2773 {
2774 	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
2775 }
2776 
2777 static const struct got_error *
2778 alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
2779     struct got_tree_entry *te, struct got_commitable *ct)
2780 {
2781 	const struct got_error *err = NULL;
2782 
2783 	*new_te = NULL;
2784 
2785 	err = got_object_tree_entry_dup(new_te, te);
2786 	if (err)
2787 		goto done;
2788 
2789 	(*new_te)->mode = get_ct_file_mode(ct);
2790 
2791 	free((*new_te)->id);
2792 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2793 	if ((*new_te)->id == NULL) {
2794 		err = got_error_from_errno("got_object_id_dup");
2795 		goto done;
2796 	}
2797 done:
2798 	if (err && *new_te) {
2799 		got_object_tree_entry_close(*new_te);
2800 		*new_te = NULL;
2801 	}
2802 	return err;
2803 }
2804 
2805 static const struct got_error *
2806 alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
2807     struct got_commitable *ct)
2808 {
2809 	const struct got_error *err = NULL;
2810 	char *ct_name;
2811 
2812 	 *new_te = NULL;
2813 
2814 	*new_te = calloc(1, sizeof(**new_te));
2815 	if (*new_te == NULL)
2816 		return got_error_from_errno("calloc");
2817 
2818 	ct_name = basename(ct->path);
2819 	if (ct_name == NULL) {
2820 		err = got_error_from_errno2("basename", ct->path);
2821 		goto done;
2822 	}
2823 	(*new_te)->name = strdup(ct_name);
2824 	if ((*new_te)->name == NULL) {
2825 		err = got_error_from_errno("strdup");
2826 		goto done;
2827 	}
2828 
2829 	(*new_te)->mode = get_ct_file_mode(ct);
2830 
2831 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2832 	if ((*new_te)->id == NULL) {
2833 		err = got_error_from_errno("got_object_id_dup");
2834 		goto done;
2835 	}
2836 done:
2837 	if (err && *new_te) {
2838 		got_object_tree_entry_close(*new_te);
2839 		*new_te = NULL;
2840 	}
2841 	return err;
2842 }
2843 
2844 static const struct got_error *
2845 insert_tree_entry(struct got_tree_entry *new_te,
2846     struct got_pathlist_head *paths)
2847 {
2848 	const struct got_error *err = NULL;
2849 	struct got_pathlist_entry *new_pe;
2850 
2851 	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
2852 	if (err)
2853 		return err;
2854 	if (new_pe == NULL)
2855 		return got_error(GOT_ERR_TREE_DUP_ENTRY);
2856 	return NULL;
2857 }
2858 
2859 static const struct got_error *
2860 report_ct_status(struct got_commitable *ct,
2861     got_worktree_status_cb status_cb, void *status_arg)
2862 {
2863 	const char *ct_path = ct->path;
2864 	while (ct_path[0] == '/')
2865 		ct_path++;
2866 	return (*status_cb)(status_arg, ct->status, ct_path, ct->blob_id, NULL);
2867 }
2868 
2869 static const struct got_error *
2870 match_modified_subtree(int *modified, struct got_tree_entry *te,
2871     const char *base_tree_path, struct got_pathlist_head *commitable_paths)
2872 {
2873 	const struct got_error *err = NULL;
2874 	struct got_pathlist_entry *pe;
2875 	char *te_path;
2876 
2877 	*modified = 0;
2878 
2879 	if (asprintf(&te_path, "%s%s%s", base_tree_path,
2880 	    got_path_is_root_dir(base_tree_path) ? "" : "/",
2881 	    te->name) == -1)
2882 		return got_error_from_errno("asprintf");
2883 
2884 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2885 		struct got_commitable *ct = pe->data;
2886 		*modified = got_path_is_child(ct->in_repo_path, te_path,
2887 		    strlen(te_path));
2888 		 if (*modified)
2889 			break;
2890 	}
2891 
2892 	free(te_path);
2893 	return err;
2894 }
2895 
2896 static const struct got_error *
2897 match_deleted_or_modified_ct(struct got_commitable **ctp,
2898     struct got_tree_entry *te, const char *base_tree_path,
2899     struct got_pathlist_head *commitable_paths)
2900 {
2901 	const struct got_error *err = NULL;
2902 	struct got_pathlist_entry *pe;
2903 
2904 	*ctp = NULL;
2905 
2906 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2907 		struct got_commitable *ct = pe->data;
2908 		char *ct_name = NULL;
2909 		int path_matches;
2910 
2911 		if (ct->status != GOT_STATUS_MODIFY &&
2912 		    ct->status != GOT_STATUS_DELETE)
2913 			continue;
2914 
2915 		if (got_object_id_cmp(ct->base_blob_id, te->id) != 0)
2916 			continue;
2917 
2918 		 err = match_ct_parent_path(&path_matches, ct, base_tree_path);
2919 		 if (err)
2920 			return err;
2921 		if (!path_matches)
2922 			continue;
2923 
2924 		ct_name = basename(pe->path);
2925 		if (ct_name == NULL)
2926 			return got_error_from_errno2("basename", pe->path);
2927 
2928 		if (strcmp(te->name, ct_name) != 0)
2929 			continue;
2930 
2931 		*ctp = ct;
2932 		break;
2933 	}
2934 
2935 	return err;
2936 }
2937 
2938 static const struct got_error *
2939 make_subtree_for_added_blob(struct got_tree_entry **new_tep,
2940     const char *child_path, const char *path_base_tree,
2941     struct got_pathlist_head *commitable_paths,
2942     got_worktree_status_cb status_cb, void *status_arg,
2943     struct got_repository *repo)
2944 {
2945 	const struct got_error *err = NULL;
2946 	struct got_tree_entry *new_te;
2947 	char *subtree_path;
2948 
2949 	*new_tep = NULL;
2950 
2951 	if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
2952 	    got_path_is_root_dir(path_base_tree) ? "" : "/",
2953 	    child_path) == -1)
2954 		return got_error_from_errno("asprintf");
2955 
2956 	new_te = calloc(1, sizeof(*new_te));
2957 	new_te->mode = S_IFDIR;
2958 	new_te->name = strdup(child_path);
2959 	if (new_te->name == NULL) {
2960 		err = got_error_from_errno("strdup");
2961 		got_object_tree_entry_close(new_te);
2962 		goto done;
2963 	}
2964 	err = write_tree(&new_te->id, NULL, subtree_path,
2965 	    commitable_paths, status_cb, status_arg, repo);
2966 	if (err) {
2967 		got_object_tree_entry_close(new_te);
2968 		goto done;
2969 	}
2970 done:
2971 	free(subtree_path);
2972 	if (err == NULL)
2973 		*new_tep = new_te;
2974 	return err;
2975 }
2976 
2977 static const struct got_error *
2978 write_tree(struct got_object_id **new_tree_id,
2979     struct got_tree_object *base_tree, const char *path_base_tree,
2980     struct got_pathlist_head *commitable_paths,
2981     got_worktree_status_cb status_cb, void *status_arg,
2982     struct got_repository *repo)
2983 {
2984 	const struct got_error *err = NULL;
2985 	const struct got_tree_entries *base_entries = NULL;
2986 	struct got_pathlist_head paths;
2987 	struct got_tree_entries new_tree_entries;
2988 	struct got_tree_entry *te, *new_te = NULL;
2989 	struct got_pathlist_entry *pe;
2990 
2991 	TAILQ_INIT(&paths);
2992 	new_tree_entries.nentries = 0;
2993 	SIMPLEQ_INIT(&new_tree_entries.head);
2994 
2995 	/* Insert, and recurse into, newly added entries first. */
2996 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2997 		struct got_commitable *ct = pe->data;
2998 		char *child_path = NULL, *slash;
2999 
3000 		if (ct->status != GOT_STATUS_ADD ||
3001 		    (ct->flags & GOT_COMMITABLE_ADDED))
3002 			continue;
3003 
3004 		 if (!got_path_is_child(pe->path, path_base_tree,
3005 		     strlen(path_base_tree)))
3006 			continue;
3007 
3008 		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
3009 		    pe->path);
3010 		if (err)
3011 			goto done;
3012 
3013 		slash = strchr(child_path, '/');
3014 		if (slash == NULL) {
3015 			err = alloc_added_blob_tree_entry(&new_te, ct);
3016 			if (err)
3017 				goto done;
3018 			err = report_ct_status(ct, status_cb, status_arg);
3019 			if (err)
3020 				goto done;
3021 			ct->flags |= GOT_COMMITABLE_ADDED;
3022 			err = insert_tree_entry(new_te, &paths);
3023 			if (err)
3024 				goto done;
3025 		} else {
3026 			*slash = '\0'; /* trim trailing path components */
3027 			if (base_tree == NULL ||
3028 			    got_object_tree_find_entry(base_tree, child_path)
3029 			    == NULL) {
3030 				err = make_subtree_for_added_blob(&new_te,
3031 				    child_path, path_base_tree,
3032 				    commitable_paths, status_cb, status_arg,
3033 				    repo);
3034 				if (err)
3035 					goto done;
3036 				err = insert_tree_entry(new_te, &paths);
3037 				if (err)
3038 					goto done;
3039 			}
3040 		}
3041 	}
3042 
3043 	if (base_tree) {
3044 		/* Handle modified and deleted entries. */
3045 		base_entries = got_object_tree_get_entries(base_tree);
3046 		SIMPLEQ_FOREACH(te, &base_entries->head, entry) {
3047 			struct got_commitable *ct = NULL;
3048 
3049 			if (S_ISDIR(te->mode)) {
3050 				int modified;
3051 				err = got_object_tree_entry_dup(&new_te, te);
3052 				if (err)
3053 					goto done;
3054 				err = match_modified_subtree(&modified, te,
3055 				    path_base_tree, commitable_paths);
3056 				if (err)
3057 					goto done;
3058 				/* Avoid recursion into unmodified subtrees. */
3059 				if (modified) {
3060 					free(new_te->id);
3061 					err = write_subtree(&new_te->id, te,
3062 					    path_base_tree, commitable_paths,
3063 					    status_cb, status_arg, repo);
3064 					if (err)
3065 						goto done;
3066 				}
3067 				err = insert_tree_entry(new_te, &paths);
3068 				if (err)
3069 					goto done;
3070 				continue;
3071 			}
3072 
3073 			err = match_deleted_or_modified_ct(&ct, te,
3074 			    path_base_tree, commitable_paths);
3075 			if (ct) {
3076 				/* NB: Deleted entries get dropped here. */
3077 				if (ct->status == GOT_STATUS_MODIFY) {
3078 					err = alloc_modified_blob_tree_entry(
3079 					    &new_te, te, ct);
3080 					if (err)
3081 						goto done;
3082 					err = insert_tree_entry(new_te, &paths);
3083 					if (err)
3084 						goto done;
3085 				}
3086 				err = report_ct_status(ct, status_cb,
3087 				    status_arg);
3088 				if (err)
3089 					goto done;
3090 			} else {
3091 				/* Entry is unchanged; just copy it. */
3092 				err = got_object_tree_entry_dup(&new_te, te);
3093 				if (err)
3094 					goto done;
3095 				err = insert_tree_entry(new_te, &paths);
3096 				if (err)
3097 					goto done;
3098 			}
3099 		}
3100 	}
3101 
3102 	/* Write new list of entries; deleted entries have been dropped. */
3103 	TAILQ_FOREACH(pe, &paths, entry) {
3104 		struct got_tree_entry *te = pe->data;
3105 		new_tree_entries.nentries++;
3106 		SIMPLEQ_INSERT_TAIL(&new_tree_entries.head, te, entry);
3107 	}
3108 	err = got_object_tree_create(new_tree_id, &new_tree_entries, repo);
3109 done:
3110 	got_object_tree_entries_close(&new_tree_entries);
3111 	got_pathlist_free(&paths);
3112 	return err;
3113 }
3114 
3115 static const struct got_error *
3116 update_fileindex_after_commit(struct got_pathlist_head *commitable_paths,
3117     struct got_object_id *new_base_commit_id, struct got_fileindex *fileindex)
3118 {
3119 	const struct got_error *err = NULL;
3120 	struct got_pathlist_entry *pe;
3121 
3122 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3123 		struct got_fileindex_entry *ie;
3124 		struct got_commitable *ct = pe->data;
3125 
3126 		ie = got_fileindex_entry_get(fileindex, pe->path);
3127 		if (ie) {
3128 			if (ct->status == GOT_STATUS_DELETE) {
3129 				got_fileindex_entry_remove(fileindex, ie);
3130 				got_fileindex_entry_free(ie);
3131 			} else
3132 				err = got_fileindex_entry_update(ie,
3133 				    ct->ondisk_path, ct->blob_id->sha1,
3134 				    new_base_commit_id->sha1, 1);
3135 		} else {
3136 			err = got_fileindex_entry_alloc(&ie,
3137 			    ct->ondisk_path, pe->path, ct->blob_id->sha1,
3138 			    new_base_commit_id->sha1);
3139 			if (err)
3140 				break;
3141 			err = got_fileindex_entry_add(fileindex, ie);
3142 			if (err)
3143 				break;
3144 		}
3145 	}
3146 	return err;
3147 }
3148 
3149 static const struct got_error *
3150 check_ct_out_of_date(struct got_commitable *ct, struct got_repository *repo,
3151 	struct got_object_id *head_commit_id)
3152 {
3153 	const struct got_error *err = NULL;
3154 	struct got_object_id *id_in_head = NULL, *id = NULL;
3155 	struct got_commit_object *commit = NULL;
3156 	char *path = NULL;
3157 	const char *ct_path = ct->in_repo_path;
3158 
3159 	while (ct_path[0] == '/')
3160 		ct_path++;
3161 
3162 	/*
3163 	 * Ensure that no modifications were made to files *and their parents*
3164 	 * in commits between the file's base commit and the branch head.
3165 	 *
3166 	 * Checking the parents is important for detecting conflicting tree
3167 	 * configurations (files or parent folders might have been moved,
3168 	 * deleted, added again, etc.). Such changes need to be merged with
3169 	 * local changes before a commit can occur.
3170 	 *
3171 	 * The implication is that the file's (parent) entry in the root
3172 	 * directory must have the same ID in all relevant commits.
3173 	 */
3174 	if (ct->status != GOT_STATUS_ADD) {
3175 		struct got_object_qid *pid;
3176 		char *slash;
3177 		struct got_object_id *root_entry_id = NULL;
3178 
3179 		/* Trivial case: base commit == head commit */
3180 		if (got_object_id_cmp(ct->base_commit_id, head_commit_id) == 0)
3181 			return NULL;
3182 
3183 		/* Compute the path to the root directory's entry. */
3184 		path = strdup(ct_path);
3185 		if (path == NULL) {
3186 			err = got_error_from_errno("strdup");
3187 			goto done;
3188 		}
3189 		slash = strchr(path, '/');
3190 		if (slash)
3191 			*slash = '\0';
3192 
3193 		err = got_object_open_as_commit(&commit, repo, head_commit_id);
3194 		if (err)
3195 			goto done;
3196 
3197 		err = got_object_id_by_path(&root_entry_id, repo,
3198 		    head_commit_id, path);
3199 		if (err)
3200 			goto done;
3201 
3202 		pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(commit));
3203 		while (pid) {
3204 			struct got_commit_object *pcommit;
3205 
3206 			err = got_object_id_by_path(&id, repo, pid->id, path);
3207 			if (err) {
3208 				if (err->code != GOT_ERR_NO_TREE_ENTRY)
3209 					goto done;
3210 				err = NULL;
3211 				break;
3212 			}
3213 
3214 			err = got_object_id_by_path(&id, repo, pid->id, path);
3215 			if (err)
3216 				goto done;
3217 
3218 			if (got_object_id_cmp(id, root_entry_id) != 0) {
3219 				err = got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3220 				break;
3221 			}
3222 
3223 			if (got_object_id_cmp(pid->id, ct->base_commit_id) == 0)
3224 				break; /* all relevant commits scanned */
3225 
3226 			err = got_object_open_as_commit(&pcommit, repo,
3227 			    pid->id);
3228 			if (err)
3229 				goto done;
3230 
3231 			got_object_commit_close(commit);
3232 			commit = pcommit;
3233 			pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(
3234 			    commit));
3235 		}
3236 	} else {
3237 		/* Require that added files don't exist in the branch head. */
3238 		err = got_object_id_by_path(&id_in_head, repo, head_commit_id,
3239 		    ct_path);
3240 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
3241 			goto done;
3242 		err = id_in_head ? got_error(GOT_ERR_COMMIT_OUT_OF_DATE) : NULL;
3243 	}
3244 done:
3245 	if (commit)
3246 		got_object_commit_close(commit);
3247 	free(id_in_head);
3248 	free(id);
3249 	free(path);
3250 	return err;
3251 }
3252 
3253 const struct got_error *
3254 commit_worktree(struct got_object_id **new_commit_id,
3255     struct got_pathlist_head *commitable_paths,
3256     struct got_object_id *head_commit_id, struct got_worktree *worktree,
3257     const char *ondisk_path, const char *author, const char *committer,
3258     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3259     got_worktree_status_cb status_cb, void *status_arg,
3260     struct got_repository *repo)
3261 {
3262 	const struct got_error *err = NULL, *unlockerr = NULL;
3263 	struct got_pathlist_entry *pe;
3264 	const char *head_ref_name = NULL;
3265 	struct got_commit_object *head_commit = NULL;
3266 	struct got_reference *head_ref2 = NULL;
3267 	struct got_object_id *head_commit_id2 = NULL;
3268 	struct got_tree_object *head_tree = NULL;
3269 	struct got_object_id *new_tree_id = NULL;
3270 	struct got_object_id_queue parent_ids;
3271 	struct got_object_qid *pid = NULL;
3272 	char *logmsg = NULL;
3273 
3274 	*new_commit_id = NULL;
3275 
3276 	SIMPLEQ_INIT(&parent_ids);
3277 
3278 	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
3279 	if (err)
3280 		goto done;
3281 
3282 	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
3283 	if (err)
3284 		goto done;
3285 
3286 	if (commit_msg_cb != NULL) {
3287 		err = commit_msg_cb(commitable_paths, &logmsg, commit_arg);
3288 		if (err)
3289 			goto done;
3290 	}
3291 
3292 	if (logmsg == NULL || strlen(logmsg) == 0) {
3293 		err = got_error(GOT_ERR_COMMIT_MSG_EMPTY);
3294 		goto done;
3295 	}
3296 
3297 	/* Create blobs from added and modified files and record their IDs. */
3298 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3299 		struct got_commitable *ct = pe->data;
3300 		char *ondisk_path;
3301 
3302 		if (ct->status != GOT_STATUS_ADD &&
3303 		    ct->status != GOT_STATUS_MODIFY)
3304 			continue;
3305 
3306 		if (asprintf(&ondisk_path, "%s/%s",
3307 		    worktree->root_path, pe->path) == -1) {
3308 			err = got_error_from_errno("asprintf");
3309 			goto done;
3310 		}
3311 		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
3312 		free(ondisk_path);
3313 		if (err)
3314 			goto done;
3315 	}
3316 
3317 	/* Recursively write new tree objects. */
3318 	err = write_tree(&new_tree_id, head_tree, "/", commitable_paths,
3319 	    status_cb, status_arg, repo);
3320 	if (err)
3321 		goto done;
3322 
3323 	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
3324 	if (err)
3325 		goto done;
3326 	SIMPLEQ_INSERT_TAIL(&parent_ids, pid, entry);
3327 	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
3328 	    1, author, time(NULL), committer, time(NULL), logmsg, repo);
3329 	got_object_qid_free(pid);
3330 	if (logmsg != NULL)
3331 		free(logmsg);
3332 	if (err)
3333 		goto done;
3334 
3335 	/* Check if a concurrent commit to our branch has occurred. */
3336 	head_ref_name = got_worktree_get_head_ref_name(worktree);
3337 	if (head_ref_name == NULL) {
3338 		err = got_error_from_errno("got_worktree_get_head_ref_name");
3339 		goto done;
3340 	}
3341 	/* Lock the reference here to prevent concurrent modification. */
3342 	err = got_ref_open(&head_ref2, repo, head_ref_name, 1);
3343 	if (err)
3344 		goto done;
3345 	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
3346 	if (err)
3347 		goto done;
3348 	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
3349 		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
3350 		goto done;
3351 	}
3352 	/* Update branch head in repository. */
3353 	err = got_ref_change_ref(head_ref2, *new_commit_id);
3354 	if (err)
3355 		goto done;
3356 	err = got_ref_write(head_ref2, repo);
3357 	if (err)
3358 		goto done;
3359 
3360 	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
3361 	if (err)
3362 		goto done;
3363 
3364 	err = ref_base_commit(worktree, repo);
3365 	if (err)
3366 		goto done;
3367 done:
3368 	if (head_tree)
3369 		got_object_tree_close(head_tree);
3370 	if (head_commit)
3371 		got_object_commit_close(head_commit);
3372 	free(head_commit_id2);
3373 	if (head_ref2) {
3374 		unlockerr = got_ref_unlock(head_ref2);
3375 		if (unlockerr && err == NULL)
3376 			err = unlockerr;
3377 		got_ref_close(head_ref2);
3378 	}
3379 	return err;
3380 }
3381 
3382 const struct got_error *
3383 got_worktree_commit(struct got_object_id **new_commit_id,
3384     struct got_worktree *worktree, const char *ondisk_path,
3385     const char *author, const char *committer,
3386     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3387     got_worktree_status_cb status_cb, void *status_arg,
3388     struct got_repository *repo)
3389 {
3390 	const struct got_error *err = NULL, *unlockerr = NULL, *sync_err;
3391 	struct got_fileindex *fileindex = NULL;
3392 	char *fileindex_path = NULL, *relpath = NULL;
3393 	struct got_pathlist_head commitable_paths;
3394 	struct collect_commitables_arg cc_arg;
3395 	struct got_pathlist_entry *pe;
3396 	struct got_reference *head_ref = NULL;
3397 	struct got_object_id *head_commit_id = NULL;
3398 
3399 	*new_commit_id = NULL;
3400 
3401 	TAILQ_INIT(&commitable_paths);
3402 
3403 	err = lock_worktree(worktree, LOCK_EX);
3404 	if (err)
3405 		goto done;
3406 
3407 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3408 	if (err)
3409 		goto done;
3410 
3411 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3412 	if (err)
3413 		goto done;
3414 
3415 	if (ondisk_path) {
3416 		err = got_path_skip_common_ancestor(&relpath,
3417 		    worktree->root_path, ondisk_path);
3418 		if (err)
3419 			return err;
3420 	}
3421 
3422 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3423 	if (err)
3424 		goto done;
3425 
3426 	cc_arg.commitable_paths = &commitable_paths;
3427 	cc_arg.worktree = worktree;
3428 	cc_arg.repo = repo;
3429 	err = worktree_status(worktree, relpath ? relpath : "",
3430 	    fileindex, repo, collect_commitables, &cc_arg, NULL, NULL);
3431 	if (err)
3432 		goto done;
3433 
3434 	if (TAILQ_EMPTY(&commitable_paths)) {
3435 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3436 		goto done;
3437 	}
3438 
3439 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3440 		struct got_commitable *ct = pe->data;
3441 		err = check_ct_out_of_date(ct, repo, head_commit_id);
3442 		if (err)
3443 			goto done;
3444 	}
3445 
3446 	err = commit_worktree(new_commit_id, &commitable_paths,
3447 	    head_commit_id, worktree, ondisk_path, author, committer,
3448 	    commit_msg_cb, commit_arg, status_cb, status_arg, repo);
3449 	if (err)
3450 		goto done;
3451 
3452 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
3453 	    fileindex);
3454 	sync_err = sync_fileindex(fileindex, fileindex_path);
3455 	if (sync_err && err == NULL)
3456 		err = sync_err;
3457 done:
3458 	if (fileindex)
3459 		got_fileindex_free(fileindex);
3460 	free(fileindex_path);
3461 	free(relpath);
3462 	unlockerr = lock_worktree(worktree, LOCK_SH);
3463 	if (unlockerr && err == NULL)
3464 		err = unlockerr;
3465 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3466 		struct got_commitable *ct = pe->data;
3467 		free_commitable(ct);
3468 	}
3469 	got_pathlist_free(&commitable_paths);
3470 	return err;
3471 }
3472 
3473 const char *
3474 got_commitable_get_path(struct got_commitable *ct)
3475 {
3476 	return ct->path;
3477 }
3478 
3479 unsigned int
3480 got_commitable_get_status(struct got_commitable *ct)
3481 {
3482 	return ct->status;
3483 }
3484 
3485 struct check_rebase_ok_arg {
3486 	struct got_worktree *worktree;
3487 	struct got_repository *repo;
3488 	int rebase_in_progress;
3489 };
3490 
3491 static const struct got_error *
3492 check_rebase_ok(void *arg, struct got_fileindex_entry *ie)
3493 {
3494 	const struct got_error *err = NULL;
3495 	struct check_rebase_ok_arg *a = arg;
3496 	unsigned char status;
3497 	struct stat sb;
3498 	char *ondisk_path;
3499 
3500 	if (!a->rebase_in_progress) {
3501 		/* Reject rebase of a work tree with mixed base commits. */
3502 		if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
3503 		    SHA1_DIGEST_LENGTH))
3504 			return got_error(GOT_ERR_MIXED_COMMITS);
3505 	}
3506 
3507 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
3508 	    == -1)
3509 		return got_error_from_errno("asprintf");
3510 
3511 	/* Reject rebase of a work tree with modified or conflicted files. */
3512 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
3513 	free(ondisk_path);
3514 	if (err)
3515 		return err;
3516 
3517 	if (a->rebase_in_progress) {
3518 		if (status == GOT_STATUS_CONFLICT)
3519 			return got_error(GOT_ERR_CONFLICTS);
3520 	} else if (status != GOT_STATUS_NO_CHANGE)
3521 		return got_error(GOT_ERR_MODIFIED);
3522 
3523 	return NULL;
3524 }
3525 
3526 const struct got_error *
3527 got_worktree_rebase_prepare(struct got_reference **new_base_branch_ref,
3528     struct got_reference **tmp_branch, struct got_worktree *worktree,
3529     struct got_reference *branch, struct got_repository *repo)
3530 {
3531 	const struct got_error *err = NULL;
3532 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
3533 	char *branch_ref_name = NULL;
3534 	struct got_fileindex *fileindex = NULL;
3535 	char *fileindex_path = NULL;
3536 	struct check_rebase_ok_arg ok_arg;
3537 	struct got_reference *wt_branch = NULL, *branch_ref = NULL;
3538 
3539 	*new_base_branch_ref = NULL;
3540 	*tmp_branch = NULL;
3541 
3542 	err = lock_worktree(worktree, LOCK_EX);
3543 	if (err)
3544 		return err;
3545 
3546 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3547 	if (err)
3548 		goto done;
3549 
3550 	ok_arg.worktree = worktree;
3551 	ok_arg.repo = repo;
3552 	ok_arg.rebase_in_progress = 0;
3553 	err = got_fileindex_for_each_entry_safe(fileindex, check_rebase_ok,
3554 	    &ok_arg);
3555 	if (err)
3556 		goto done;
3557 
3558 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3559 	if (err)
3560 		goto done;
3561 
3562 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3563 	if (err)
3564 		goto done;
3565 
3566 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3567 	if (err)
3568 		goto done;
3569 
3570 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
3571 	    0);
3572 	if (err)
3573 		goto done;
3574 
3575 	err = got_ref_alloc_symref(new_base_branch_ref,
3576 	    new_base_branch_ref_name, wt_branch);
3577 	if (err)
3578 		goto done;
3579 	err = got_ref_write(*new_base_branch_ref, repo);
3580 	if (err)
3581 		goto done;
3582 
3583 	/* TODO Lock original branch's ref while rebasing? */
3584 
3585 	err = got_ref_alloc_symref(&branch_ref, branch_ref_name, branch);
3586 	if (err)
3587 		goto done;
3588 
3589 	err = got_ref_write(branch_ref, repo);
3590 	if (err)
3591 		goto done;
3592 
3593 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
3594 	    worktree->base_commit_id);
3595 	if (err)
3596 		goto done;
3597 	err = got_ref_write(*tmp_branch, repo);
3598 	if (err)
3599 		goto done;
3600 
3601 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
3602 	if (err)
3603 		goto done;
3604 done:
3605 	free(fileindex_path);
3606 	if (fileindex)
3607 		got_fileindex_free(fileindex);
3608 	free(tmp_branch_name);
3609 	free(new_base_branch_ref_name);
3610 	free(branch_ref_name);
3611 	if (branch_ref)
3612 		got_ref_close(branch_ref);
3613 	if (wt_branch)
3614 		got_ref_close(wt_branch);
3615 	if (err) {
3616 		if (*new_base_branch_ref) {
3617 			got_ref_close(*new_base_branch_ref);
3618 			*new_base_branch_ref = NULL;
3619 		}
3620 		if (*tmp_branch) {
3621 			got_ref_close(*tmp_branch);
3622 			*tmp_branch = NULL;
3623 		}
3624 		lock_worktree(worktree, LOCK_SH);
3625 	}
3626 	return err;
3627 }
3628 
3629 const struct got_error *
3630 got_worktree_rebase_continue(struct got_object_id **commit_id,
3631     struct got_reference **new_base_branch, struct got_reference **tmp_branch,
3632     struct got_reference **branch, struct got_worktree *worktree,
3633     struct got_repository *repo)
3634 {
3635 	const struct got_error *err;
3636 	char *commit_ref_name = NULL, *new_base_branch_ref_name = NULL;
3637 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
3638 	struct got_reference *commit_ref = NULL, *branch_ref = NULL;
3639 
3640 	*commit_id = NULL;
3641 
3642 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3643 	if (err)
3644 		return err;
3645 
3646 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3647 	if (err)
3648 		goto done;
3649 
3650 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3651 	if (err)
3652 		goto done;
3653 
3654 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3655 	if (err)
3656 		goto done;
3657 
3658 	err = got_ref_open(&branch_ref, repo, branch_ref_name, 0);
3659 	if (err)
3660 		goto done;
3661 
3662 	err = got_ref_open(branch, repo,
3663 	    got_ref_get_symref_target(branch_ref), 0);
3664 	if (err)
3665 		goto done;
3666 
3667 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3668 	if (err)
3669 		goto done;
3670 
3671 	err = got_ref_resolve(commit_id, repo, commit_ref);
3672 	if (err)
3673 		goto done;
3674 
3675 	err = got_ref_open(new_base_branch, repo,
3676 	    new_base_branch_ref_name, 0);
3677 	if (err)
3678 		goto done;
3679 
3680 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
3681 	if (err)
3682 		goto done;
3683 done:
3684 	free(commit_ref_name);
3685 	free(branch_ref_name);
3686 	if (commit_ref)
3687 		got_ref_close(commit_ref);
3688 	if (branch_ref)
3689 		got_ref_close(branch_ref);
3690 	if (err) {
3691 		free(*commit_id);
3692 		*commit_id = NULL;
3693 		if (*tmp_branch) {
3694 			got_ref_close(*tmp_branch);
3695 			*tmp_branch = NULL;
3696 		}
3697 		if (*new_base_branch) {
3698 			got_ref_close(*new_base_branch);
3699 			*new_base_branch = NULL;
3700 		}
3701 		if (*branch) {
3702 			got_ref_close(*branch);
3703 			*branch = NULL;
3704 		}
3705 	}
3706 	return err;
3707 }
3708 
3709 const struct got_error *
3710 got_worktree_rebase_in_progress(int *in_progress, struct got_worktree *worktree)
3711 {
3712 	const struct got_error *err;
3713 	char *tmp_branch_name = NULL;
3714 
3715 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3716 	if (err)
3717 		return err;
3718 
3719 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
3720 	free(tmp_branch_name);
3721 	return NULL;
3722 }
3723 
3724 static const struct got_error *
3725 collect_rebase_commit_msg(struct got_pathlist_head *commitable_paths,
3726     char **logmsg, void *arg)
3727 {
3728 	struct got_commit_object *commit = arg;
3729 
3730 	*logmsg = strdup(got_object_commit_get_logmsg(commit));
3731 	if (*logmsg == NULL)
3732 		return got_error_from_errno("strdup");
3733 
3734 	return NULL;
3735 }
3736 
3737 static const struct got_error *
3738 rebase_status(void *arg, unsigned char status, const char *path,
3739     struct got_object_id *blob_id, struct got_object_id *commit_id)
3740 {
3741 	return NULL;
3742 }
3743 
3744 struct collect_merged_paths_arg {
3745 	got_worktree_checkout_cb progress_cb;
3746 	void *progress_arg;
3747 	struct got_pathlist_head *merged_paths;
3748 };
3749 
3750 static const struct got_error *
3751 collect_merged_paths(void *arg, unsigned char status, const char *path)
3752 {
3753 	const struct got_error *err;
3754 	struct collect_merged_paths_arg *a = arg;
3755 	char *p;
3756 	struct got_pathlist_entry *new;
3757 
3758 	err = (*a->progress_cb)(a->progress_arg, status, path);
3759 	if (err)
3760 		return err;
3761 
3762 	if (status != GOT_STATUS_MERGE &&
3763 	    status != GOT_STATUS_ADD &&
3764 	    status != GOT_STATUS_DELETE &&
3765 	    status != GOT_STATUS_CONFLICT)
3766 		return NULL;
3767 
3768 	p = strdup(path);
3769 	if (p == NULL)
3770 		return got_error_from_errno("strdup");
3771 
3772 	err = got_pathlist_insert(&new, a->merged_paths, p, NULL);
3773 	if (err || new == NULL)
3774 		free(p);
3775 	return err;
3776 }
3777 
3778 void
3779 got_worktree_rebase_pathlist_free(struct got_pathlist_head *merged_paths)
3780 {
3781 	struct got_pathlist_entry *pe;
3782 
3783 	TAILQ_FOREACH(pe, merged_paths, entry)
3784 		free((char *)pe->path);
3785 
3786 	got_pathlist_free(merged_paths);
3787 }
3788 
3789 const struct got_error *
3790 got_worktree_rebase_merge_files(struct got_pathlist_head *merged_paths,
3791     struct got_worktree *worktree, struct got_object_id *parent_commit_id,
3792     struct got_object_id *commit_id, struct got_repository *repo,
3793     got_worktree_checkout_cb progress_cb, void *progress_arg,
3794     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
3795 {
3796 	const struct got_error *err;
3797 	struct got_fileindex *fileindex;
3798 	char *fileindex_path, *commit_ref_name = NULL;
3799 	struct got_reference *commit_ref = NULL;
3800 	struct collect_merged_paths_arg cmp_arg;
3801 
3802 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
3803 
3804 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3805 	if (err)
3806 		return err;
3807 
3808 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3809 	if (err)
3810 		goto done;
3811 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3812 	if (err) {
3813 		if (err->code != GOT_ERR_NOT_REF)
3814 			goto done;
3815 		err = got_ref_alloc(&commit_ref, commit_ref_name, commit_id);
3816 		if (err)
3817 			goto done;
3818 		err = got_ref_write(commit_ref, repo);
3819 		if (err)
3820 			goto done;
3821 	} else {
3822 		struct got_object_id *stored_id;
3823 		int cmp;
3824 
3825 		err = got_ref_resolve(&stored_id, repo, commit_ref);
3826 		if (err)
3827 			goto done;
3828 		cmp = got_object_id_cmp(commit_id, stored_id);
3829 		free(stored_id);
3830 		if (cmp != 0) {
3831 			err = got_error(GOT_ERR_REBASE_COMMITID);
3832 			goto done;
3833 		}
3834 	}
3835 
3836 	cmp_arg.progress_cb = progress_cb;
3837 	cmp_arg.progress_arg = progress_arg;
3838 	cmp_arg.merged_paths = merged_paths;
3839 	err = merge_files(worktree, fileindex, fileindex_path,
3840 	    parent_commit_id, commit_id, repo, collect_merged_paths,
3841 	    &cmp_arg, cancel_cb, cancel_arg);
3842 done:
3843 	got_fileindex_free(fileindex);
3844 	free(fileindex_path);
3845 	if (commit_ref)
3846 		got_ref_close(commit_ref);
3847 	return err;
3848 }
3849 
3850 const struct got_error *
3851 got_worktree_rebase_commit(struct got_object_id **new_commit_id,
3852     struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
3853     struct got_reference *tmp_branch, struct got_commit_object *orig_commit,
3854     struct got_object_id *orig_commit_id, struct got_repository *repo)
3855 {
3856 	const struct got_error *err, *sync_err;
3857 	struct got_pathlist_head commitable_paths;
3858 	struct collect_commitables_arg cc_arg;
3859 	struct got_fileindex *fileindex = NULL;
3860 	char *fileindex_path = NULL, *commit_ref_name = NULL;
3861 	struct got_reference *head_ref = NULL;
3862 	struct got_object_id *head_commit_id = NULL;
3863 	struct got_reference *commit_ref = NULL;
3864 	struct got_object_id *commit_id = NULL;
3865 
3866 	TAILQ_INIT(&commitable_paths);
3867 	*new_commit_id = NULL;
3868 
3869 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
3870 
3871 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3872 	if (err)
3873 		return err;
3874 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3875 	if (err)
3876 		goto done;
3877 	err = got_ref_resolve(&commit_id, repo, commit_ref);
3878 	if (err)
3879 		goto done;
3880 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
3881 		err = got_error(GOT_ERR_REBASE_COMMITID);
3882 		goto done;
3883 	}
3884 
3885 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3886 	if (err)
3887 		goto done;
3888 
3889 	cc_arg.commitable_paths = &commitable_paths;
3890 	cc_arg.worktree = worktree;
3891 	cc_arg.repo = repo;
3892 	/*
3893 	 * If possible get the status of individual files directly to
3894 	 * avoid crawling the entire work tree once per rebased commit.
3895 	 * TODO: Ideally, merged_paths would contain a list of commitables
3896 	 * we could use so we could skip worktree_status() entirely.
3897 	 */
3898 	if (merged_paths) {
3899 		struct got_pathlist_entry *pe;
3900 		TAILQ_FOREACH(pe, merged_paths, entry) {
3901 			err = worktree_status(worktree, pe->path, fileindex,
3902 			    repo, collect_commitables, &cc_arg, NULL, NULL);
3903 			if (err)
3904 				goto done;
3905 		}
3906 	} else {
3907 		err = worktree_status(worktree, "", fileindex, repo,
3908 		    collect_commitables, &cc_arg, NULL, NULL);
3909 		if (err)
3910 			goto done;
3911 	}
3912 
3913 	if (TAILQ_EMPTY(&commitable_paths)) {
3914 		/* No-op change; commit will be elided. */
3915 		err = got_ref_delete(commit_ref, repo);
3916 		if (err)
3917 			goto done;
3918 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3919 		goto done;
3920 	}
3921 
3922 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3923 	if (err)
3924 		goto done;
3925 
3926 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3927 	if (err)
3928 		goto done;
3929 
3930 	err = commit_worktree(new_commit_id, &commitable_paths, head_commit_id,
3931 	    worktree, NULL, got_object_commit_get_author(orig_commit),
3932 	    got_object_commit_get_committer(orig_commit),
3933 	    collect_rebase_commit_msg, orig_commit,
3934 	    rebase_status, NULL, repo);
3935 	if (err)
3936 		goto done;
3937 
3938 	err = got_ref_change_ref(tmp_branch, *new_commit_id);
3939 	if (err)
3940 		goto done;
3941 
3942 	err = got_ref_delete(commit_ref, repo);
3943 	if (err)
3944 		goto done;
3945 
3946 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
3947 	    fileindex);
3948 	sync_err = sync_fileindex(fileindex, fileindex_path);
3949 	if (sync_err && err == NULL)
3950 		err = sync_err;
3951 done:
3952 	if (fileindex)
3953 		got_fileindex_free(fileindex);
3954 	free(fileindex_path);
3955 	free(commit_ref_name);
3956 	if (commit_ref)
3957 		got_ref_close(commit_ref);
3958 	free(head_commit_id);
3959 	if (head_ref)
3960 		got_ref_close(head_ref);
3961 	if (err) {
3962 		free(*new_commit_id);
3963 		*new_commit_id = NULL;
3964 	}
3965 	return err;
3966 }
3967 
3968 const struct got_error *
3969 got_worktree_rebase_postpone(struct got_worktree *worktree)
3970 {
3971 	return lock_worktree(worktree, LOCK_SH);
3972 }
3973 
3974 static const struct got_error *
3975 delete_ref(const char *name, struct got_repository *repo)
3976 {
3977 	const struct got_error *err;
3978 	struct got_reference *ref;
3979 
3980 	err = got_ref_open(&ref, repo, name, 0);
3981 	if (err) {
3982 		if (err->code == GOT_ERR_NOT_REF)
3983 			return NULL;
3984 		return err;
3985 	}
3986 
3987 	err = got_ref_delete(ref, repo);
3988 	got_ref_close(ref);
3989 	return err;
3990 }
3991 
3992 static const struct got_error *
3993 delete_rebase_refs(struct got_worktree *worktree, struct got_repository *repo)
3994 {
3995 	const struct got_error *err;
3996 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
3997 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
3998 
3999 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
4000 	if (err)
4001 		goto done;
4002 	err = delete_ref(tmp_branch_name, repo);
4003 	if (err)
4004 		goto done;
4005 
4006 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
4007 	if (err)
4008 		goto done;
4009 	err = delete_ref(new_base_branch_ref_name, repo);
4010 	if (err)
4011 		goto done;
4012 
4013 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
4014 	if (err)
4015 		goto done;
4016 	err = delete_ref(branch_ref_name, repo);
4017 	if (err)
4018 		goto done;
4019 
4020 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4021 	if (err)
4022 		goto done;
4023 	err = delete_ref(commit_ref_name, repo);
4024 	if (err)
4025 		goto done;
4026 
4027 done:
4028 	free(tmp_branch_name);
4029 	free(new_base_branch_ref_name);
4030 	free(branch_ref_name);
4031 	free(commit_ref_name);
4032 	return err;
4033 }
4034 
4035 const struct got_error *
4036 got_worktree_rebase_complete(struct got_worktree *worktree,
4037     struct got_reference *new_base_branch, struct got_reference *tmp_branch,
4038     struct got_reference *rebased_branch,
4039     struct got_repository *repo)
4040 {
4041 	const struct got_error *err, *unlockerr;
4042 	struct got_object_id *new_head_commit_id = NULL;
4043 
4044 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
4045 	if (err)
4046 		return err;
4047 
4048 	err = got_ref_change_ref(rebased_branch, new_head_commit_id);
4049 	if (err)
4050 		goto done;
4051 
4052 	err = got_ref_write(rebased_branch, repo);
4053 	if (err)
4054 		goto done;
4055 
4056 	err = got_worktree_set_head_ref(worktree, rebased_branch);
4057 	if (err)
4058 		goto done;
4059 
4060 	err = delete_rebase_refs(worktree, repo);
4061 done:
4062 	free(new_head_commit_id);
4063 	unlockerr = lock_worktree(worktree, LOCK_SH);
4064 	if (unlockerr && err == NULL)
4065 		err = unlockerr;
4066 	return err;
4067 }
4068 
4069 struct collect_revertible_paths_arg {
4070 	struct got_pathlist_head *revertible_paths;
4071 	struct got_worktree *worktree;
4072 };
4073 
4074 static const struct got_error *
4075 collect_revertible_paths(void *arg, unsigned char status, const char *relpath,
4076     struct got_object_id *blob_id, struct got_object_id *commit_id)
4077 {
4078 	struct collect_revertible_paths_arg *a = arg;
4079 	const struct got_error *err = NULL;
4080 	struct got_pathlist_entry *new = NULL;
4081 	char *path = NULL;
4082 
4083 	if (status != GOT_STATUS_ADD &&
4084 	    status != GOT_STATUS_DELETE &&
4085 	    status != GOT_STATUS_MODIFY &&
4086 	    status != GOT_STATUS_CONFLICT &&
4087 	    status != GOT_STATUS_MISSING)
4088 		return NULL;
4089 
4090 	if (asprintf(&path, "%s/%s", a->worktree->root_path, relpath) == -1)
4091 		return got_error_from_errno("asprintf");
4092 
4093 	err = got_pathlist_insert(&new, a->revertible_paths, path, NULL);
4094 	if (err || new == NULL)
4095 		free(path);
4096 	return err;
4097 }
4098 
4099 const struct got_error *
4100 got_worktree_rebase_abort(struct got_worktree *worktree,
4101     struct got_repository *repo, struct got_reference *new_base_branch,
4102      got_worktree_checkout_cb progress_cb, void *progress_arg)
4103 {
4104 	const struct got_error *err, *unlockerr, *sync_err;
4105 	struct got_reference *resolved = NULL;
4106 	struct got_object_id *commit_id = NULL;
4107 	struct got_fileindex *fileindex = NULL;
4108 	char *fileindex_path = NULL;
4109 	struct got_pathlist_head revertible_paths;
4110 	struct got_pathlist_entry *pe;
4111 	struct collect_revertible_paths_arg crp_arg;
4112 	struct got_object_id *tree_id = NULL;
4113 
4114 	TAILQ_INIT(&revertible_paths);
4115 
4116 	err = lock_worktree(worktree, LOCK_EX);
4117 	if (err)
4118 		return err;
4119 
4120 	err = got_ref_open(&resolved, repo,
4121 	    got_ref_get_symref_target(new_base_branch), 0);
4122 	if (err)
4123 		goto done;
4124 
4125 	err = got_worktree_set_head_ref(worktree, resolved);
4126 	if (err)
4127 		goto done;
4128 
4129 	/*
4130 	 * XXX commits to the base branch could have happened while
4131 	 * we were busy rebasing; should we store the original commit ID
4132 	 * when rebase begins and read it back here?
4133 	 */
4134 	err = got_ref_resolve(&commit_id, repo, resolved);
4135 	if (err)
4136 		goto done;
4137 
4138 	err = got_worktree_set_base_commit_id(worktree, repo, commit_id);
4139 	if (err)
4140 		goto done;
4141 
4142 	err = got_object_id_by_path(&tree_id, repo,
4143 	    worktree->base_commit_id, worktree->path_prefix);
4144 	if (err)
4145 		goto done;
4146 
4147 	err = delete_rebase_refs(worktree, repo);
4148 	if (err)
4149 		goto done;
4150 
4151 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
4152 	if (err)
4153 		goto done;
4154 
4155 	crp_arg.revertible_paths = &revertible_paths;
4156 	crp_arg.worktree = worktree;
4157 	err = worktree_status(worktree, "", fileindex, repo,
4158 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4159 	if (err)
4160 		goto done;
4161 
4162 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4163 		err = revert_file(worktree, fileindex, pe->path,
4164 		    progress_cb, progress_arg, repo);
4165 		if (err)
4166 			goto sync;
4167 	}
4168 
4169 	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
4170 	    repo, progress_cb, progress_arg, NULL, NULL);
4171 sync:
4172 	sync_err = sync_fileindex(fileindex, fileindex_path);
4173 	if (sync_err && err == NULL)
4174 		err = sync_err;
4175 done:
4176 	got_ref_close(resolved);
4177 	free(tree_id);
4178 	free(commit_id);
4179 	if (fileindex)
4180 		got_fileindex_free(fileindex);
4181 	free(fileindex_path);
4182 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4183 		free((char *)pe->path);
4184 	got_pathlist_free(&revertible_paths);
4185 
4186 	unlockerr = lock_worktree(worktree, LOCK_SH);
4187 	if (unlockerr && err == NULL)
4188 		err = unlockerr;
4189 	return err;
4190 }