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 	(*progress_cb)(progress_arg,
807 	    overlapcnt > 0 ? GOT_STATUS_CONFLICT : GOT_STATUS_MERGE, path);
808 
809 	if (fsync(merged_fd) != 0) {
810 		err = got_error_from_errno("fsync");
811 		goto done;
812 	}
813 
814 	/* Check if a clean merge has subsumed all local changes. */
815 	if (overlapcnt == 0) {
816 		err = check_files_equal(local_changes_subsumed, blob_deriv_path,
817 		    merged_path);
818 		if (err)
819 			goto done;
820 	}
821 
822 	if (chmod(merged_path, st_mode) != 0) {
823 		err = got_error_from_errno2("chmod", merged_path);
824 		goto done;
825 	}
826 
827 	if (rename(merged_path, ondisk_path) != 0) {
828 		err = got_error_from_errno3("rename", merged_path,
829 		    ondisk_path);
830 		unlink(merged_path);
831 		goto done;
832 	}
833 
834 done:
835 	if (merged_fd != -1 && close(merged_fd) != 0 && err == NULL)
836 		err = got_error_from_errno("close");
837 	if (f_deriv && fclose(f_deriv) != 0 && err == NULL)
838 		err = got_error_from_errno("fclose");
839 	if (f_orig && fclose(f_orig) != 0 && err == NULL)
840 		err = got_error_from_errno("fclose");
841 	free(merged_path);
842 	free(base_path);
843 	if (blob_deriv_path) {
844 		unlink(blob_deriv_path);
845 		free(blob_deriv_path);
846 	}
847 	if (blob_orig_path) {
848 		unlink(blob_orig_path);
849 		free(blob_orig_path);
850 	}
851 	free(id_str);
852 	free(label_deriv);
853 	return err;
854 }
855 
856 static const struct got_error *
857 update_blob_fileindex_entry(struct got_worktree *worktree,
858     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
859     const char *ondisk_path, const char *path, struct got_blob_object *blob,
860     int update_timestamps)
861 {
862 	const struct got_error *err = NULL;
863 
864 	if (ie == NULL)
865 		ie = got_fileindex_entry_get(fileindex, path);
866 	if (ie)
867 		err = got_fileindex_entry_update(ie, ondisk_path,
868 		    blob->id.sha1, worktree->base_commit_id->sha1,
869 		    update_timestamps);
870 	else {
871 		struct got_fileindex_entry *new_ie;
872 		err = got_fileindex_entry_alloc(&new_ie, ondisk_path,
873 		    path, blob->id.sha1, worktree->base_commit_id->sha1);
874 		if (!err)
875 			err = got_fileindex_entry_add(fileindex, new_ie);
876 	}
877 	return err;
878 }
879 
880 static const struct got_error *
881 install_blob(struct got_worktree *worktree, const char *ondisk_path,
882    const char *path, uint16_t te_mode, uint16_t st_mode,
883    struct got_blob_object *blob, int restoring_missing_file,
884    int reverting_versioned_file, struct got_repository *repo,
885    got_worktree_checkout_cb progress_cb, void *progress_arg)
886 {
887 	const struct got_error *err = NULL;
888 	int fd = -1;
889 	size_t len, hdrlen;
890 	int update = 0;
891 	char *tmppath = NULL;
892 
893 	fd = open(ondisk_path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
894 	    GOT_DEFAULT_FILE_MODE);
895 	if (fd == -1) {
896 		if (errno == ENOENT) {
897 			char *parent = dirname(path);
898 			if (parent == NULL)
899 				return got_error_from_errno2("dirname", path);
900 			err = add_dir_on_disk(worktree, parent);
901 			if (err)
902 				return err;
903 			fd = open(ondisk_path,
904 			    O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
905 			    GOT_DEFAULT_FILE_MODE);
906 			if (fd == -1)
907 				return got_error_from_errno2("open",
908 				    ondisk_path);
909 		} else if (errno == EEXIST) {
910 			if (!S_ISREG(st_mode)) {
911 				/* TODO file is obstructed; do something */
912 				err = got_error(GOT_ERR_FILE_OBSTRUCTED);
913 				goto done;
914 			} else {
915 				err = got_opentemp_named_fd(&tmppath, &fd,
916 				    ondisk_path);
917 				if (err)
918 					goto done;
919 				update = 1;
920 			}
921 		} else
922 			return got_error_from_errno2("open", ondisk_path);
923 	}
924 
925 	if (restoring_missing_file)
926 		(*progress_cb)(progress_arg, GOT_STATUS_MISSING, path);
927 	else if (reverting_versioned_file)
928 		(*progress_cb)(progress_arg, GOT_STATUS_REVERT, path);
929 	else
930 		(*progress_cb)(progress_arg,
931 		    update ? GOT_STATUS_UPDATE : GOT_STATUS_ADD, path);
932 
933 	hdrlen = got_object_blob_get_hdrlen(blob);
934 	do {
935 		const uint8_t *buf = got_object_blob_get_read_buf(blob);
936 		err = got_object_blob_read_block(&len, blob);
937 		if (err)
938 			break;
939 		if (len > 0) {
940 			/* Skip blob object header first time around. */
941 			ssize_t outlen = write(fd, buf + hdrlen, len - hdrlen);
942 			if (outlen == -1) {
943 				err = got_error_from_errno("write");
944 				goto done;
945 			} else if (outlen != len - hdrlen) {
946 				err = got_error(GOT_ERR_IO);
947 				goto done;
948 			}
949 			hdrlen = 0;
950 		}
951 	} while (len != 0);
952 
953 	if (fsync(fd) != 0) {
954 		err = got_error_from_errno("fsync");
955 		goto done;
956 	}
957 
958 	if (update) {
959 		if (rename(tmppath, ondisk_path) != 0) {
960 			err = got_error_from_errno3("rename", tmppath,
961 			    ondisk_path);
962 			unlink(tmppath);
963 			goto done;
964 		}
965 	}
966 
967 	if (te_mode & S_IXUSR) {
968 		if (chmod(ondisk_path, st_mode | S_IXUSR) == -1) {
969 			err = got_error_from_errno2("chmod", ondisk_path);
970 			goto done;
971 		}
972 	} else {
973 		if (chmod(ondisk_path, st_mode & ~S_IXUSR) == -1) {
974 			err = got_error_from_errno2("chmod", ondisk_path);
975 			goto done;
976 		}
977 	}
978 
979 done:
980 	if (fd != -1 && close(fd) != 0 && err == NULL)
981 		err = got_error_from_errno("close");
982 	free(tmppath);
983 	return err;
984 }
985 
986 /* Upgrade STATUS_MODIFY to STATUS_CONFLICT if a conflict marker is found. */
987 static const struct got_error *
988 get_modified_file_content_status(unsigned char *status, FILE *f)
989 {
990 	const struct got_error *err = NULL;
991 	const char *markers[3] = {
992 		GOT_DIFF_CONFLICT_MARKER_BEGIN,
993 		GOT_DIFF_CONFLICT_MARKER_SEP,
994 		GOT_DIFF_CONFLICT_MARKER_END
995 	};
996 	int i = 0;
997 	char *line;
998 	size_t len;
999 	const char delim[3] = {'\0', '\0', '\0'};
1000 
1001 	while (*status == GOT_STATUS_MODIFY) {
1002 		line = fparseln(f, &len, NULL, delim, 0);
1003 		if (line == NULL) {
1004 			if (feof(f))
1005 				break;
1006 			err = got_ferror(f, GOT_ERR_IO);
1007 			break;
1008 		}
1009 
1010 		if (strncmp(line, markers[i], strlen(markers[i])) == 0) {
1011 			if (strcmp(markers[i], GOT_DIFF_CONFLICT_MARKER_END)
1012 			    == 0)
1013 				*status = GOT_STATUS_CONFLICT;
1014 			else
1015 				i++;
1016 		}
1017 	}
1018 
1019 	return err;
1020 }
1021 
1022 static const struct got_error *
1023 get_file_status(unsigned char *status, struct stat *sb,
1024     struct got_fileindex_entry *ie, const char *abspath,
1025     struct got_repository *repo)
1026 {
1027 	const struct got_error *err = NULL;
1028 	struct got_object_id id;
1029 	size_t hdrlen;
1030 	FILE *f = NULL;
1031 	uint8_t fbuf[8192];
1032 	struct got_blob_object *blob = NULL;
1033 	size_t flen, blen;
1034 
1035 	*status = GOT_STATUS_NO_CHANGE;
1036 
1037 	if (lstat(abspath, sb) == -1) {
1038 		if (errno == ENOENT) {
1039 			if (ie) {
1040 				if (got_fileindex_entry_has_file_on_disk(ie))
1041 					*status = GOT_STATUS_MISSING;
1042 				else
1043 					*status = GOT_STATUS_DELETE;
1044 				sb->st_mode =
1045 				    ((ie->mode >> GOT_FILEIDX_MODE_PERMS_SHIFT)
1046 				    & (S_IRWXU | S_IRWXG | S_IRWXO));
1047 			} else
1048 				sb->st_mode = GOT_DEFAULT_FILE_MODE;
1049 			return NULL;
1050 		}
1051 		return got_error_from_errno2("lstat", abspath);
1052 	}
1053 
1054 	if (!S_ISREG(sb->st_mode)) {
1055 		*status = GOT_STATUS_OBSTRUCTED;
1056 		return NULL;
1057 	}
1058 
1059 	if (ie == NULL)
1060 		return NULL;
1061 
1062 	if (!got_fileindex_entry_has_file_on_disk(ie)) {
1063 		*status = GOT_STATUS_DELETE;
1064 		return NULL;
1065 	} else if (!got_fileindex_entry_has_blob(ie)) {
1066 		*status = GOT_STATUS_ADD;
1067 		return NULL;
1068 	}
1069 
1070 	if (ie->ctime_sec == sb->st_ctime &&
1071 	    ie->ctime_nsec == sb->st_ctimensec &&
1072 	    ie->mtime_sec == sb->st_mtime &&
1073 	    ie->mtime_sec == sb->st_mtime &&
1074 	    ie->mtime_nsec == sb->st_mtimensec &&
1075 	    ie->size == (sb->st_size & 0xffffffff))
1076 		return NULL;
1077 
1078 	memcpy(id.sha1, ie->blob_sha1, sizeof(id.sha1));
1079 	err = got_object_open_as_blob(&blob, repo, &id, sizeof(fbuf));
1080 	if (err)
1081 		return err;
1082 
1083 	f = fopen(abspath, "r");
1084 	if (f == NULL) {
1085 		err = got_error_from_errno2("fopen", abspath);
1086 		goto done;
1087 	}
1088 	hdrlen = got_object_blob_get_hdrlen(blob);
1089 	for (;;) {
1090 		const uint8_t *bbuf = got_object_blob_get_read_buf(blob);
1091 		err = got_object_blob_read_block(&blen, blob);
1092 		if (err)
1093 			goto done;
1094 		/* Skip length of blob object header first time around. */
1095 		flen = fread(fbuf, 1, sizeof(fbuf) - hdrlen, f);
1096 		if (flen == 0 && ferror(f)) {
1097 			err = got_error_from_errno("fread");
1098 			goto done;
1099 		}
1100 		if (blen == 0) {
1101 			if (flen != 0)
1102 				*status = GOT_STATUS_MODIFY;
1103 			break;
1104 		} else if (flen == 0) {
1105 			if (blen != 0)
1106 				*status = GOT_STATUS_MODIFY;
1107 			break;
1108 		} else if (blen - hdrlen == flen) {
1109 			/* Skip blob object header first time around. */
1110 			if (memcmp(bbuf + hdrlen, fbuf, flen) != 0) {
1111 				*status = GOT_STATUS_MODIFY;
1112 				break;
1113 			}
1114 		} else {
1115 			*status = GOT_STATUS_MODIFY;
1116 			break;
1117 		}
1118 		hdrlen = 0;
1119 	}
1120 
1121 	if (*status == GOT_STATUS_MODIFY) {
1122 		rewind(f);
1123 		err = get_modified_file_content_status(status, f);
1124 	}
1125 done:
1126 	if (blob)
1127 		got_object_blob_close(blob);
1128 	if (f)
1129 		fclose(f);
1130 	return err;
1131 }
1132 
1133 static const struct got_error *
1134 update_blob(struct got_worktree *worktree,
1135     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
1136     struct got_tree_entry *te, const char *path,
1137     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1138     void *progress_arg)
1139 {
1140 	const struct got_error *err = NULL;
1141 	struct got_blob_object *blob = NULL;
1142 	char *ondisk_path;
1143 	unsigned char status = GOT_STATUS_NO_CHANGE;
1144 	struct stat sb;
1145 
1146 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
1147 		return got_error_from_errno("asprintf");
1148 
1149 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1150 	if (err)
1151 		goto done;
1152 
1153 	if (status == GOT_STATUS_OBSTRUCTED) {
1154 		(*progress_cb)(progress_arg, status, path);
1155 		goto done;
1156 	}
1157 
1158 	if (ie && status != GOT_STATUS_MISSING) {
1159 		if (got_fileindex_entry_has_commit(ie) &&
1160 		    memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
1161 		    SHA1_DIGEST_LENGTH) == 0) {
1162 			(*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
1163 			    path);
1164 			goto done;
1165 		}
1166 		if (got_fileindex_entry_has_blob(ie) &&
1167 		    memcmp(ie->blob_sha1, te->id->sha1,
1168 		    SHA1_DIGEST_LENGTH) == 0)
1169 			goto done;
1170 	}
1171 
1172 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
1173 	if (err)
1174 		goto done;
1175 
1176 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_ADD) {
1177 		int update_timestamps;
1178 		struct got_blob_object *blob2 = NULL;
1179 		if (got_fileindex_entry_has_blob(ie)) {
1180 			struct got_object_id id2;
1181 			memcpy(id2.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1182 			err = got_object_open_as_blob(&blob2, repo, &id2, 8192);
1183 			if (err)
1184 				goto done;
1185 		}
1186 		err = merge_blob(&update_timestamps, worktree, blob2,
1187 		    ondisk_path, path, sb.st_mode, blob,
1188 		    worktree->base_commit_id, repo,
1189 		    progress_cb, progress_arg);
1190 		if (blob2)
1191 			got_object_blob_close(blob2);
1192 		/*
1193 		 * Do not update timestamps of files with local changes.
1194 		 * Otherwise, a future status walk would treat them as
1195 		 * unmodified files again.
1196 		 */
1197 		err = got_fileindex_entry_update(ie, ondisk_path,
1198 		    blob->id.sha1, worktree->base_commit_id->sha1,
1199 		    update_timestamps);
1200 	} else if (status == GOT_STATUS_DELETE) {
1201 		(*progress_cb)(progress_arg, GOT_STATUS_MERGE, path);
1202 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1203 		    ondisk_path, path, blob, 0);
1204 		if (err)
1205 			goto done;
1206 	} else {
1207 		err = install_blob(worktree, ondisk_path, path, te->mode,
1208 		    sb.st_mode, blob, status == GOT_STATUS_MISSING, 0,
1209 		    repo, progress_cb, progress_arg);
1210 		if (err)
1211 			goto done;
1212 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1213 		    ondisk_path, path, blob, 1);
1214 		if (err)
1215 			goto done;
1216 	}
1217 	got_object_blob_close(blob);
1218 done:
1219 	free(ondisk_path);
1220 	return err;
1221 }
1222 
1223 static const struct got_error *
1224 remove_ondisk_file(const char *root_path, const char *path)
1225 {
1226 	const struct got_error *err = NULL;
1227 	char *ondisk_path = NULL;
1228 
1229 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
1230 		return got_error_from_errno("asprintf");
1231 
1232 	if (unlink(ondisk_path) == -1) {
1233 		if (errno != ENOENT)
1234 			err = got_error_from_errno2("unlink", ondisk_path);
1235 	} else {
1236 		char *parent = dirname(ondisk_path);
1237 		while (parent && strcmp(parent, root_path) != 0) {
1238 			if (rmdir(parent) == -1) {
1239 				if (errno != ENOTEMPTY)
1240 					err = got_error_from_errno2("rmdir",
1241 					    parent);
1242 				break;
1243 			}
1244 			parent = dirname(parent);
1245 		}
1246 	}
1247 	free(ondisk_path);
1248 	return err;
1249 }
1250 
1251 static const struct got_error *
1252 delete_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
1253     struct got_fileindex_entry *ie, struct got_repository *repo,
1254     got_worktree_checkout_cb progress_cb, void *progress_arg)
1255 {
1256 	const struct got_error *err = NULL;
1257 	unsigned char status;
1258 	struct stat sb;
1259 	char *ondisk_path;
1260 
1261 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, ie->path)
1262 	    == -1)
1263 		return got_error_from_errno("asprintf");
1264 
1265 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1266 	if (err)
1267 		return err;
1268 
1269 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_CONFLICT ||
1270 	    status == GOT_STATUS_ADD) {
1271 		(*progress_cb)(progress_arg, GOT_STATUS_MERGE, ie->path);
1272 		/*
1273 		 * Preserve the working file and change the deleted blob's
1274 		 * entry into a schedule-add entry.
1275 		 */
1276 		err = got_fileindex_entry_update(ie, ondisk_path, NULL, NULL,
1277 		    0);
1278 		if (err)
1279 			return err;
1280 	} else {
1281 		(*progress_cb)(progress_arg, GOT_STATUS_DELETE, ie->path);
1282 		if (status == GOT_STATUS_NO_CHANGE) {
1283 			err = remove_ondisk_file(worktree->root_path, ie->path);
1284 			if (err)
1285 				return err;
1286 		}
1287 		got_fileindex_entry_remove(fileindex, ie);
1288 	}
1289 
1290 	return err;
1291 }
1292 
1293 struct diff_cb_arg {
1294     struct got_fileindex *fileindex;
1295     struct got_worktree *worktree;
1296     struct got_repository *repo;
1297     got_worktree_checkout_cb progress_cb;
1298     void *progress_arg;
1299     got_worktree_cancel_cb cancel_cb;
1300     void *cancel_arg;
1301 };
1302 
1303 static const struct got_error *
1304 diff_old_new(void *arg, struct got_fileindex_entry *ie,
1305     struct got_tree_entry *te, const char *parent_path)
1306 {
1307 	struct diff_cb_arg *a = arg;
1308 
1309 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1310 		return got_error(GOT_ERR_CANCELLED);
1311 
1312 	return update_blob(a->worktree, a->fileindex, ie, te,
1313 	    ie->path, a->repo, a->progress_cb, a->progress_arg);
1314 }
1315 
1316 static const struct got_error *
1317 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1318 {
1319 	struct diff_cb_arg *a = arg;
1320 
1321 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1322 		return got_error(GOT_ERR_CANCELLED);
1323 
1324 	return delete_blob(a->worktree, a->fileindex, ie,
1325 	    a->repo, a->progress_cb, a->progress_arg);
1326 }
1327 
1328 static const struct got_error *
1329 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
1330 {
1331 	struct diff_cb_arg *a = arg;
1332 	const struct got_error *err;
1333 	char *path;
1334 
1335 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1336 		return got_error(GOT_ERR_CANCELLED);
1337 
1338 	if (asprintf(&path, "%s%s%s", parent_path,
1339 	    parent_path[0] ? "/" : "", te->name)
1340 	    == -1)
1341 		return got_error_from_errno("asprintf");
1342 
1343 	if (S_ISDIR(te->mode))
1344 		err = add_dir_on_disk(a->worktree, path);
1345 	else
1346 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
1347 		    a->repo, a->progress_cb, a->progress_arg);
1348 
1349 	free(path);
1350 	return err;
1351 }
1352 
1353 static const struct got_error *
1354 get_ref_name(char **refname, struct got_worktree *worktree, const char *prefix)
1355 {
1356 	const struct got_error *err = NULL;
1357 	char *uuidstr = NULL;
1358 	uint32_t uuid_status;
1359 
1360 	*refname = NULL;
1361 
1362 	uuid_to_string(&worktree->uuid, &uuidstr, &uuid_status);
1363 	if (uuid_status != uuid_s_ok)
1364 		return got_error_uuid(uuid_status);
1365 
1366 	if (asprintf(refname, "%s-%s", prefix, uuidstr)
1367 	    == -1) {
1368 		err = got_error_from_errno("asprintf");
1369 		*refname = NULL;
1370 	}
1371 	free(uuidstr);
1372 	return err;
1373 }
1374 
1375 const struct got_error *
1376 got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
1377 {
1378 	return get_ref_name(refname, worktree, GOT_WORKTREE_BASE_REF_PREFIX);
1379 }
1380 
1381 static const struct got_error *
1382 get_rebase_tmp_ref_name(char **refname, struct got_worktree *worktree)
1383 {
1384 	return get_ref_name(refname, worktree,
1385 	    GOT_WORKTREE_REBASE_TMP_REF_PREFIX);
1386 }
1387 
1388 static const struct got_error *
1389 get_newbase_symref_name(char **refname, struct got_worktree *worktree)
1390 {
1391 	return get_ref_name(refname, worktree, GOT_WORKTREE_NEWBASE_REF_PREFIX);
1392 }
1393 
1394 static const struct got_error *
1395 get_rebase_branch_symref_name(char **refname, struct got_worktree *worktree)
1396 {
1397 	return get_ref_name(refname, worktree,
1398 	    GOT_WORKTREE_REBASE_BRANCH_REF_PREFIX);
1399 }
1400 
1401 static const struct got_error *
1402 get_rebase_commit_ref_name(char **refname, struct got_worktree *worktree)
1403 {
1404 	return get_ref_name(refname, worktree,
1405 	    GOT_WORKTREE_REBASE_COMMIT_REF_PREFIX);
1406 }
1407 
1408 
1409 /*
1410  * Prevent Git's garbage collector from deleting our base commit by
1411  * setting a reference to our base commit's ID.
1412  */
1413 static const struct got_error *
1414 ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
1415 {
1416 	const struct got_error *err = NULL;
1417 	struct got_reference *ref = NULL;
1418 	char *refname;
1419 
1420 	err = got_worktree_get_base_ref_name(&refname, worktree);
1421 	if (err)
1422 		return err;
1423 
1424 	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
1425 	if (err)
1426 		goto done;
1427 
1428 	err = got_ref_write(ref, repo);
1429 done:
1430 	free(refname);
1431 	if (ref)
1432 		got_ref_close(ref);
1433 	return err;
1434 }
1435 
1436 static const struct got_error *
1437 open_fileindex(struct got_fileindex **fileindex, char **fileindex_path,
1438    struct got_worktree *worktree)
1439 {
1440 	const struct got_error *err = NULL;
1441 	FILE *index = NULL;
1442 
1443 	*fileindex_path = NULL;
1444 	*fileindex = got_fileindex_alloc();
1445 	if (*fileindex == NULL)
1446 		return got_error_from_errno("got_fileindex_alloc");
1447 
1448 	if (asprintf(fileindex_path, "%s/%s/%s", worktree->root_path,
1449 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1450 		err = got_error_from_errno("asprintf");
1451 		*fileindex_path = NULL;
1452 		goto done;
1453 	}
1454 
1455 	index = fopen(*fileindex_path, "rb");
1456 	if (index == NULL) {
1457 		if (errno != ENOENT)
1458 			err = got_error_from_errno2("fopen", *fileindex_path);
1459 	} else {
1460 		err = got_fileindex_read(*fileindex, index);
1461 		if (fclose(index) != 0 && err == NULL)
1462 			err = got_error_from_errno("fclose");
1463 	}
1464 done:
1465 	if (err) {
1466 		free(*fileindex_path);
1467 		*fileindex_path = NULL;
1468 		got_fileindex_free(*fileindex);
1469 		*fileindex = NULL;
1470 	}
1471 	return err;
1472 }
1473 
1474 struct bump_base_commit_id_arg {
1475 	struct got_object_id *base_commit_id;
1476 	const char *path;
1477 	size_t path_len;
1478 	const char *entry_name;
1479 	got_worktree_checkout_cb progress_cb;
1480 	void *progress_arg;
1481 };
1482 
1483 /* Bump base commit ID of all files within an updated part of the work tree. */
1484 static const struct got_error *
1485 bump_base_commit_id(void *arg, struct got_fileindex_entry *ie)
1486 {
1487 	struct bump_base_commit_id_arg *a = arg;
1488 
1489 	if (a->entry_name) {
1490 		if (strcmp(ie->path, a->path) != 0)
1491 			return NULL;
1492 	} else if (!got_path_is_child(ie->path, a->path, a->path_len))
1493 		return NULL;
1494 
1495 	if (memcmp(ie->commit_sha1, a->base_commit_id->sha1,
1496 	    SHA1_DIGEST_LENGTH) == 0)
1497 		return NULL;
1498 
1499 	if (a->progress_cb)
1500 		(*a->progress_cb)(a->progress_arg, GOT_STATUS_BUMP_BASE,
1501 		    ie->path);
1502 	memcpy(ie->commit_sha1, a->base_commit_id->sha1, SHA1_DIGEST_LENGTH);
1503 	return NULL;
1504 }
1505 
1506 static const struct got_error *
1507 sync_fileindex(struct got_fileindex *fileindex, const char *fileindex_path)
1508 {
1509 	const struct got_error *err = NULL;
1510 	char *new_fileindex_path = NULL;
1511 	FILE *new_index = NULL;
1512 
1513 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1514 	    fileindex_path);
1515 	if (err)
1516 		goto done;
1517 
1518 	err = got_fileindex_write(fileindex, new_index);
1519 	if (err)
1520 		goto done;
1521 
1522 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1523 		err = got_error_from_errno3("rename", new_fileindex_path,
1524 		    fileindex_path);
1525 		unlink(new_fileindex_path);
1526 	}
1527 done:
1528 	if (new_index)
1529 		fclose(new_index);
1530 	free(new_fileindex_path);
1531 	return err;
1532 }
1533 
1534 static const struct got_error *
1535 find_tree_entry_for_checkout(int *entry_type, char **tree_relpath,
1536     struct got_object_id **tree_id, const char *wt_relpath,
1537     struct got_worktree *worktree, struct got_repository *repo)
1538 {
1539 	const struct got_error *err = NULL;
1540 	struct got_object_id *id = NULL;
1541 	char *in_repo_path = NULL;
1542 	int is_root_wt = got_path_is_root_dir(worktree->path_prefix);
1543 
1544 	*entry_type = GOT_OBJ_TYPE_ANY;
1545 	*tree_relpath = NULL;
1546 	*tree_id = NULL;
1547 
1548 	if (wt_relpath[0] == '\0') {
1549 		/* Check out all files within the work tree. */
1550 		*entry_type = GOT_OBJ_TYPE_TREE;
1551 		*tree_relpath = strdup("");
1552 		if (*tree_relpath == NULL) {
1553 			err = got_error_from_errno("strdup");
1554 			goto done;
1555 		}
1556 		err = got_object_id_by_path(tree_id, repo,
1557 		    worktree->base_commit_id, worktree->path_prefix);
1558 		if (err)
1559 			goto done;
1560 		return NULL;
1561 	}
1562 
1563 	/* Check out a subset of files in the work tree. */
1564 
1565 	if (asprintf(&in_repo_path, "%s%s%s", worktree->path_prefix,
1566 	    is_root_wt ? "" : "/", wt_relpath) == -1) {
1567 		err = got_error_from_errno("asprintf");
1568 		goto done;
1569 	}
1570 
1571 	err = got_object_id_by_path(&id, repo, worktree->base_commit_id,
1572 	    in_repo_path);
1573 	if (err)
1574 		goto done;
1575 
1576 	free(in_repo_path);
1577 	in_repo_path = NULL;
1578 
1579 	err = got_object_get_type(entry_type, repo, id);
1580 	if (err)
1581 		goto done;
1582 
1583 	if (*entry_type == GOT_OBJ_TYPE_BLOB) {
1584 		/* Check out a single file. */
1585 		if (strchr(wt_relpath, '/')  == NULL) {
1586 			/* Check out a single file in work tree's root dir. */
1587 			in_repo_path = strdup(worktree->path_prefix);
1588 			if (in_repo_path == NULL) {
1589 				err = got_error_from_errno("strdup");
1590 				goto done;
1591 			}
1592 			*tree_relpath = strdup("");
1593 			if (*tree_relpath == NULL) {
1594 				err = got_error_from_errno("strdup");
1595 				goto done;
1596 			}
1597 		} else {
1598 			/* Check out a single file in a subdirectory. */
1599 			err = got_path_dirname(tree_relpath, wt_relpath);
1600 			if (err)
1601 				return err;
1602 			if (asprintf(&in_repo_path, "%s%s%s",
1603 			    worktree->path_prefix, is_root_wt ? "" : "/",
1604 			    *tree_relpath) == -1) {
1605 				err = got_error_from_errno("asprintf");
1606 				goto done;
1607 			}
1608 		}
1609 		err = got_object_id_by_path(tree_id, repo,
1610 		    worktree->base_commit_id, in_repo_path);
1611 	} else {
1612 		/* Check out all files within a subdirectory. */
1613 		*tree_id = got_object_id_dup(id);
1614 		if (*tree_id == NULL) {
1615 			err = got_error_from_errno("got_object_id_dup");
1616 			goto done;
1617 		}
1618 		*tree_relpath = strdup(wt_relpath);
1619 		if (*tree_relpath == NULL) {
1620 			err = got_error_from_errno("strdup");
1621 			goto done;
1622 		}
1623 	}
1624 done:
1625 	free(id);
1626 	free(in_repo_path);
1627 	if (err) {
1628 		*entry_type = GOT_OBJ_TYPE_ANY;
1629 		free(*tree_relpath);
1630 		*tree_relpath = NULL;
1631 		free(*tree_id);
1632 		*tree_id = NULL;
1633 	}
1634 	return err;
1635 }
1636 
1637 static const struct got_error *
1638 checkout_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
1639     const char *relpath, struct got_object_id *tree_id, const char *entry_name,
1640     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1641     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1642 {
1643 	const struct got_error *err = NULL;
1644 	struct got_commit_object *commit = NULL;
1645 	struct got_tree_object *tree = NULL;
1646 	struct got_fileindex_diff_tree_cb diff_cb;
1647 	struct diff_cb_arg arg;
1648 
1649 	err = ref_base_commit(worktree, repo);
1650 	if (err)
1651 		goto done;
1652 
1653 	err = got_object_open_as_commit(&commit, repo,
1654 	   worktree->base_commit_id);
1655 	if (err)
1656 		goto done;
1657 
1658 	err = got_object_open_as_tree(&tree, repo, tree_id);
1659 	if (err)
1660 		goto done;
1661 
1662 	if (entry_name &&
1663 	    got_object_tree_find_entry(tree, entry_name) == NULL) {
1664 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
1665 		goto done;
1666 	}
1667 
1668 	diff_cb.diff_old_new = diff_old_new;
1669 	diff_cb.diff_old = diff_old;
1670 	diff_cb.diff_new = diff_new;
1671 	arg.fileindex = fileindex;
1672 	arg.worktree = worktree;
1673 	arg.repo = repo;
1674 	arg.progress_cb = progress_cb;
1675 	arg.progress_arg = progress_arg;
1676 	arg.cancel_cb = cancel_cb;
1677 	arg.cancel_arg = cancel_arg;
1678 	err = got_fileindex_diff_tree(fileindex, tree, relpath,
1679 	    entry_name, repo, &diff_cb, &arg);
1680 done:
1681 	if (tree)
1682 		got_object_tree_close(tree);
1683 	if (commit)
1684 		got_object_commit_close(commit);
1685 	return err;
1686 }
1687 
1688 const struct got_error *
1689 got_worktree_checkout_files(struct got_worktree *worktree, const char *path,
1690     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1691     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1692 {
1693 	const struct got_error *err = NULL, *sync_err, *unlockerr;
1694 	struct got_commit_object *commit = NULL;
1695 	struct got_object_id *tree_id = NULL;
1696 	struct got_tree_object *tree = NULL;
1697 	struct got_fileindex *fileindex = NULL;
1698 	char *fileindex_path = NULL;
1699 	char *relpath = NULL, *entry_name = NULL;
1700 	int entry_type;
1701 
1702 	err = lock_worktree(worktree, LOCK_EX);
1703 	if (err)
1704 		return err;
1705 
1706 	err = find_tree_entry_for_checkout(&entry_type, &relpath, &tree_id,
1707 	    path, worktree, repo);
1708 	if (err)
1709 		goto done;
1710 
1711 	if (entry_type == GOT_OBJ_TYPE_BLOB) {
1712 		entry_name = basename(path);
1713 		if (entry_name == NULL) {
1714 			err = got_error_from_errno2("basename", path);
1715 			goto done;
1716 		}
1717 	}
1718 
1719 	/*
1720 	 * Read the file index.
1721 	 * Checking out files is supposed to be an idempotent operation.
1722 	 * If the on-disk file index is incomplete we will try to complete it.
1723 	 */
1724 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1725 	if (err)
1726 		goto done;
1727 
1728 	err = checkout_files(worktree, fileindex, relpath, tree_id, entry_name,
1729 	    repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
1730 	if (err == NULL) {
1731 		struct bump_base_commit_id_arg bbc_arg;
1732 		bbc_arg.base_commit_id = worktree->base_commit_id;
1733 		bbc_arg.entry_name = entry_name;
1734 		bbc_arg.path = path;
1735 		bbc_arg.path_len = strlen(path);
1736 		bbc_arg.progress_cb = progress_cb;
1737 		bbc_arg.progress_arg = progress_arg;
1738 		err = got_fileindex_for_each_entry_safe(fileindex,
1739 		    bump_base_commit_id, &bbc_arg);
1740 	}
1741 	sync_err = sync_fileindex(fileindex, fileindex_path);
1742 	if (sync_err && err == NULL)
1743 		err = sync_err;
1744 done:
1745 	free(fileindex_path);
1746 	free(relpath);
1747 	if (tree)
1748 		got_object_tree_close(tree);
1749 	if (commit)
1750 		got_object_commit_close(commit);
1751 	if (fileindex)
1752 		got_fileindex_free(fileindex);
1753 	unlockerr = lock_worktree(worktree, LOCK_SH);
1754 	if (unlockerr && err == NULL)
1755 		err = unlockerr;
1756 	return err;
1757 }
1758 
1759 struct merge_file_cb_arg {
1760     struct got_worktree *worktree;
1761     struct got_fileindex *fileindex;
1762     got_worktree_checkout_cb progress_cb;
1763     void *progress_arg;
1764     got_worktree_cancel_cb cancel_cb;
1765     void *cancel_arg;
1766     struct got_object_id *commit_id2;
1767 };
1768 
1769 static const struct got_error *
1770 merge_file_cb(void *arg, struct got_blob_object *blob1,
1771     struct got_blob_object *blob2, struct got_object_id *id1,
1772     struct got_object_id *id2, const char *path1, const char *path2,
1773     struct got_repository *repo)
1774 {
1775 	static const struct got_error *err = NULL;
1776 	struct merge_file_cb_arg *a = arg;
1777 	struct got_fileindex_entry *ie;
1778 	char *ondisk_path = NULL;
1779 	struct stat sb;
1780 	unsigned char status;
1781 	int local_changes_subsumed;
1782 
1783 	if (blob1 && blob2) {
1784 		ie = got_fileindex_entry_get(a->fileindex, path2);
1785 		if (ie == NULL) {
1786 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MISSING,
1787 			    path2);
1788 			return NULL;
1789 		}
1790 
1791 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1792 		    path2) == -1)
1793 			return got_error_from_errno("asprintf");
1794 
1795 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1796 		if (err)
1797 			goto done;
1798 
1799 		if (status == GOT_STATUS_DELETE) {
1800 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MERGE,
1801 			    path2);
1802 			goto done;
1803 		}
1804 		if (status != GOT_STATUS_NO_CHANGE &&
1805 		    status != GOT_STATUS_MODIFY &&
1806 		    status != GOT_STATUS_CONFLICT &&
1807 		    status != GOT_STATUS_ADD) {
1808 			(*a->progress_cb)(a->progress_arg, status, path2);
1809 			goto done;
1810 		}
1811 
1812 		err = merge_blob(&local_changes_subsumed, a->worktree, blob1,
1813 		    ondisk_path, path2, sb.st_mode, blob2, a->commit_id2, repo,
1814 		    a->progress_cb, a->progress_arg);
1815 	} else if (blob1) {
1816 		ie = got_fileindex_entry_get(a->fileindex, path1);
1817 		if (ie == NULL) {
1818 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MISSING,
1819 			    path2);
1820 			return NULL;
1821 		}
1822 
1823 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1824 		    path1) == -1)
1825 			return got_error_from_errno("asprintf");
1826 
1827 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1828 		if (err)
1829 			goto done;
1830 
1831 		switch (status) {
1832 		case GOT_STATUS_NO_CHANGE:
1833 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE,
1834 			    path1);
1835 			err = remove_ondisk_file(a->worktree->root_path, path1);
1836 			if (err)
1837 				goto done;
1838 			if (ie)
1839 				got_fileindex_entry_mark_deleted_from_disk(ie);
1840 			break;
1841 		case GOT_STATUS_DELETE:
1842 		case GOT_STATUS_MISSING:
1843 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE,
1844 			    path1);
1845 			if (ie)
1846 				got_fileindex_entry_mark_deleted_from_disk(ie);
1847 			break;
1848 		case GOT_STATUS_ADD:
1849 		case GOT_STATUS_MODIFY:
1850 		case GOT_STATUS_CONFLICT:
1851 			(*a->progress_cb)(a->progress_arg,
1852 			    GOT_STATUS_CANNOT_DELETE, path1);
1853 			break;
1854 		case GOT_STATUS_OBSTRUCTED:
1855 			(*a->progress_cb)(a->progress_arg, status, path1);
1856 			break;
1857 		default:
1858 			break;
1859 		}
1860 	} else if (blob2) {
1861 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1862 		    path2) == -1)
1863 			return got_error_from_errno("asprintf");
1864 		ie = got_fileindex_entry_get(a->fileindex, path2);
1865 		if (ie) {
1866 			err = get_file_status(&status, &sb, ie, ondisk_path,
1867 			    repo);
1868 			if (err)
1869 				goto done;
1870 			if (status != GOT_STATUS_NO_CHANGE &&
1871 			    status != GOT_STATUS_MODIFY &&
1872 			    status != GOT_STATUS_CONFLICT &&
1873 			    status != GOT_STATUS_ADD) {
1874 				(*a->progress_cb)(a->progress_arg, status,
1875 				    path2);
1876 				goto done;
1877 			}
1878 			err = merge_blob(&local_changes_subsumed, a->worktree,
1879 			    NULL, ondisk_path, path2, sb.st_mode, blob2,
1880 			    a->commit_id2, repo,
1881 			    a->progress_cb, a->progress_arg);
1882 			if (status == GOT_STATUS_DELETE) {
1883 				err = update_blob_fileindex_entry(a->worktree,
1884 				    a->fileindex, ie, ondisk_path, ie->path,
1885 				    blob2, 0);
1886 				if (err)
1887 					goto done;
1888 			}
1889 		} else {
1890 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1891 			err = install_blob(a->worktree, ondisk_path, path2,
1892 			    /* XXX get this from parent tree! */
1893 			    GOT_DEFAULT_FILE_MODE,
1894 			    sb.st_mode, blob2, 0, 0, repo,
1895 			    a->progress_cb, a->progress_arg);
1896 			if (err)
1897 				goto done;
1898 			err = got_fileindex_entry_alloc(&ie,
1899 			    ondisk_path, path2, NULL, NULL);
1900 			if (err)
1901 				goto done;
1902 			err = got_fileindex_entry_add(a->fileindex, ie);
1903 			if (err) {
1904 				got_fileindex_entry_free(ie);
1905 				goto done;
1906 			}
1907 		}
1908 	}
1909 done:
1910 	free(ondisk_path);
1911 	return err;
1912 }
1913 
1914 struct check_merge_ok_arg {
1915 	struct got_worktree *worktree;
1916 	struct got_repository *repo;
1917 };
1918 
1919 static const struct got_error *
1920 check_merge_ok(void *arg, struct got_fileindex_entry *ie)
1921 {
1922 	const struct got_error *err = NULL;
1923 	struct check_merge_ok_arg *a = arg;
1924 	unsigned char status;
1925 	struct stat sb;
1926 	char *ondisk_path;
1927 
1928 	/* Reject merges into a work tree with mixed base commits. */
1929 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
1930 	    SHA1_DIGEST_LENGTH))
1931 		return got_error(GOT_ERR_MIXED_COMMITS);
1932 
1933 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
1934 	    == -1)
1935 		return got_error_from_errno("asprintf");
1936 
1937 	/* Reject merges into a work tree with conflicted files. */
1938 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
1939 	if (err)
1940 		return err;
1941 	if (status == GOT_STATUS_CONFLICT)
1942 		return got_error(GOT_ERR_CONFLICTS);
1943 
1944 	return NULL;
1945 }
1946 
1947 static const struct got_error *
1948 merge_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
1949     const char *fileindex_path, struct got_object_id *commit_id1,
1950     struct got_object_id *commit_id2, struct got_repository *repo,
1951     got_worktree_checkout_cb progress_cb, void *progress_arg,
1952     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1953 {
1954 	const struct got_error *err = NULL, *sync_err;
1955 	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
1956 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1957 	struct merge_file_cb_arg arg;
1958 
1959 	if (commit_id1) {
1960 		err = got_object_id_by_path(&tree_id1, repo, commit_id1,
1961 		    worktree->path_prefix);
1962 		if (err)
1963 			goto done;
1964 
1965 		err = got_object_open_as_tree(&tree1, repo, tree_id1);
1966 		if (err)
1967 			goto done;
1968 	}
1969 
1970 	err = got_object_id_by_path(&tree_id2, repo, commit_id2,
1971 	    worktree->path_prefix);
1972 	if (err)
1973 		goto done;
1974 
1975 	err = got_object_open_as_tree(&tree2, repo, tree_id2);
1976 	if (err)
1977 		goto done;
1978 
1979 	arg.worktree = worktree;
1980 	arg.fileindex = fileindex;
1981 	arg.progress_cb = progress_cb;
1982 	arg.progress_arg = progress_arg;
1983 	arg.cancel_cb = cancel_cb;
1984 	arg.cancel_arg = cancel_arg;
1985 	arg.commit_id2 = commit_id2;
1986 	err = got_diff_tree(tree1, tree2, "", "", repo, merge_file_cb, &arg);
1987 	sync_err = sync_fileindex(fileindex, fileindex_path);
1988 	if (sync_err && err == NULL)
1989 		err = sync_err;
1990 done:
1991 	if (tree1)
1992 		got_object_tree_close(tree1);
1993 	if (tree2)
1994 		got_object_tree_close(tree2);
1995 	return err;
1996 }
1997 
1998 const struct got_error *
1999 got_worktree_merge_files(struct got_worktree *worktree,
2000     struct got_object_id *commit_id1, struct got_object_id *commit_id2,
2001     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
2002     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2003 {
2004 	const struct got_error *err, *unlockerr;
2005 	char *fileindex_path = NULL;
2006 	struct got_fileindex *fileindex = NULL;
2007 	struct check_merge_ok_arg mok_arg;
2008 
2009 	err = lock_worktree(worktree, LOCK_EX);
2010 	if (err)
2011 		return err;
2012 
2013 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2014 	if (err)
2015 		goto done;
2016 
2017 	mok_arg.worktree = worktree;
2018 	mok_arg.repo = repo;
2019 	err = got_fileindex_for_each_entry_safe(fileindex, check_merge_ok,
2020 	    &mok_arg);
2021 	if (err)
2022 		goto done;
2023 
2024 	err = merge_files(worktree, fileindex, fileindex_path, commit_id1,
2025 	    commit_id2, repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
2026 done:
2027 	if (fileindex)
2028 		got_fileindex_free(fileindex);
2029 	free(fileindex_path);
2030 	unlockerr = lock_worktree(worktree, LOCK_SH);
2031 	if (unlockerr && err == NULL)
2032 		err = unlockerr;
2033 	return err;
2034 }
2035 
2036 struct diff_dir_cb_arg {
2037     struct got_fileindex *fileindex;
2038     struct got_worktree *worktree;
2039     const char *status_path;
2040     size_t status_path_len;
2041     struct got_repository *repo;
2042     got_worktree_status_cb status_cb;
2043     void *status_arg;
2044     got_worktree_cancel_cb cancel_cb;
2045     void *cancel_arg;
2046 };
2047 
2048 static const struct got_error *
2049 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
2050     got_worktree_status_cb status_cb, void *status_arg,
2051     struct got_repository *repo)
2052 {
2053 	const struct got_error *err = NULL;
2054 	unsigned char status = GOT_STATUS_NO_CHANGE;
2055 	struct stat sb;
2056 	struct got_object_id blob_id, commit_id;
2057 
2058 	err = get_file_status(&status, &sb, ie, abspath, repo);
2059 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
2060 		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2061 		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2062 		err = (*status_cb)(status_arg, status, ie->path, &blob_id,
2063 		    &commit_id);
2064 	}
2065 	return err;
2066 }
2067 
2068 static const struct got_error *
2069 status_old_new(void *arg, struct got_fileindex_entry *ie,
2070     struct dirent *de, const char *parent_path)
2071 {
2072 	const struct got_error *err = NULL;
2073 	struct diff_dir_cb_arg *a = arg;
2074 	char *abspath;
2075 
2076 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2077 		return got_error(GOT_ERR_CANCELLED);
2078 
2079 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
2080 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
2081 		return NULL;
2082 
2083 	if (parent_path[0]) {
2084 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
2085 		    parent_path, de->d_name) == -1)
2086 			return got_error_from_errno("asprintf");
2087 	} else {
2088 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
2089 		    de->d_name) == -1)
2090 			return got_error_from_errno("asprintf");
2091 	}
2092 
2093 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
2094 	    a->repo);
2095 	free(abspath);
2096 	return err;
2097 }
2098 
2099 static const struct got_error *
2100 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
2101 {
2102 	struct diff_dir_cb_arg *a = arg;
2103 	struct got_object_id blob_id, commit_id;
2104 	unsigned char status;
2105 
2106 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2107 		return got_error(GOT_ERR_CANCELLED);
2108 
2109 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2110 		return NULL;
2111 
2112 	memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2113 	memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2114 	if (got_fileindex_entry_has_file_on_disk(ie))
2115 		status = GOT_STATUS_MISSING;
2116 	else
2117 		status = GOT_STATUS_DELETE;
2118 	return (*a->status_cb)(a->status_arg, status, ie->path, &blob_id,
2119 	    &commit_id);
2120 }
2121 
2122 static const struct got_error *
2123 status_new(void *arg, struct dirent *de, const char *parent_path)
2124 {
2125 	const struct got_error *err = NULL;
2126 	struct diff_dir_cb_arg *a = arg;
2127 	char *path = NULL;
2128 
2129 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2130 		return got_error(GOT_ERR_CANCELLED);
2131 
2132 	if (de->d_type == DT_DIR)
2133 		return NULL;
2134 
2135 	/* XXX ignore symlinks for now */
2136 	if (de->d_type == DT_LNK)
2137 		return NULL;
2138 
2139 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2140 		return NULL;
2141 
2142 	if (parent_path[0]) {
2143 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
2144 			return got_error_from_errno("asprintf");
2145 	} else {
2146 		path = de->d_name;
2147 	}
2148 
2149 	err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED, path,
2150 	    NULL, NULL);
2151 	if (parent_path[0])
2152 		free(path);
2153 	return err;
2154 }
2155 
2156 static const struct got_error *
2157 worktree_status(struct got_worktree *worktree, const char *path,
2158     struct got_fileindex *fileindex, struct got_repository *repo,
2159     got_worktree_status_cb status_cb, void *status_arg,
2160     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2161 {
2162 	const struct got_error *err = NULL;
2163 	DIR *workdir = NULL;
2164 	struct got_fileindex_diff_dir_cb fdiff_cb;
2165 	struct diff_dir_cb_arg arg;
2166 	char *ondisk_path = NULL;
2167 
2168 	if (asprintf(&ondisk_path, "%s%s%s",
2169 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
2170 		err = got_error_from_errno("asprintf");
2171 		goto done;
2172 	}
2173 	workdir = opendir(ondisk_path);
2174 	if (workdir == NULL) {
2175 		if (errno == ENOTDIR || errno == ENOENT) {
2176 			struct got_fileindex_entry *ie;
2177 			ie = got_fileindex_entry_get(fileindex, path);
2178 			if (ie == NULL) {
2179 				err = got_error(GOT_ERR_BAD_PATH);
2180 				goto done;
2181 			}
2182 			err = report_file_status(ie, ondisk_path,
2183 			    status_cb, status_arg, repo);
2184 			goto done;
2185 		} else {
2186 			err = got_error_from_errno2("opendir", ondisk_path);
2187 			goto done;
2188 		}
2189 	}
2190 	fdiff_cb.diff_old_new = status_old_new;
2191 	fdiff_cb.diff_old = status_old;
2192 	fdiff_cb.diff_new = status_new;
2193 	arg.fileindex = fileindex;
2194 	arg.worktree = worktree;
2195 	arg.status_path = path;
2196 	arg.status_path_len = strlen(path);
2197 	arg.repo = repo;
2198 	arg.status_cb = status_cb;
2199 	arg.status_arg = status_arg;
2200 	arg.cancel_cb = cancel_cb;
2201 	arg.cancel_arg = cancel_arg;
2202 	err = got_fileindex_diff_dir(fileindex, workdir, worktree->root_path,
2203 	    path, repo, &fdiff_cb, &arg);
2204 done:
2205 	if (workdir)
2206 		closedir(workdir);
2207 	free(ondisk_path);
2208 	return err;
2209 }
2210 
2211 const struct got_error *
2212 got_worktree_status(struct got_worktree *worktree, const char *path,
2213     struct got_repository *repo, got_worktree_status_cb status_cb,
2214     void *status_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2215 {
2216 	const struct got_error *err = NULL;
2217 	char *fileindex_path = NULL;
2218 	struct got_fileindex *fileindex = NULL;
2219 
2220 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2221 	if (err)
2222 		return err;
2223 
2224 	err = worktree_status(worktree, path, fileindex, repo,
2225 	    status_cb, status_arg, cancel_cb, cancel_arg);
2226 	free(fileindex_path);
2227 	got_fileindex_free(fileindex);
2228 	return err;
2229 }
2230 
2231 const struct got_error *
2232 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
2233     const char *arg)
2234 {
2235 	const struct got_error *err = NULL;
2236 	char *resolved, *path = NULL;
2237 	size_t len;
2238 
2239 	*wt_path = NULL;
2240 
2241 	resolved = realpath(arg, NULL);
2242 	if (resolved == NULL)
2243 		return got_error_from_errno2("realpath", arg);
2244 
2245 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
2246 	    strlen(got_worktree_get_root_path(worktree)))) {
2247 		err = got_error(GOT_ERR_BAD_PATH);
2248 		goto done;
2249 	}
2250 
2251 	if (strlen(resolved) > strlen(got_worktree_get_root_path(worktree))) {
2252 		err = got_path_skip_common_ancestor(&path,
2253 		    got_worktree_get_root_path(worktree), resolved);
2254 		if (err)
2255 			goto done;
2256 	} else {
2257 		path = strdup("");
2258 		if (path == NULL) {
2259 			err = got_error_from_errno("strdup");
2260 			goto done;
2261 		}
2262 	}
2263 
2264 	/* XXX status walk can't deal with trailing slash! */
2265 	len = strlen(path);
2266 	while (path[len - 1] == '/') {
2267 		path[len - 1] = '\0';
2268 		len--;
2269 	}
2270 done:
2271 	free(resolved);
2272 	if (err == NULL)
2273 		*wt_path = path;
2274 	else
2275 		free(path);
2276 	return err;
2277 }
2278 
2279 static const struct got_error *
2280 schedule_addition(const char *ondisk_path, struct got_fileindex *fileindex,
2281     const char *relpath, got_worktree_status_cb status_cb, void *status_arg,
2282     struct got_repository *repo)
2283 {
2284 	const struct got_error *err = NULL;
2285 	struct got_fileindex_entry *ie;
2286 
2287 	/* Re-adding an existing entry is a no-op. */
2288 	if (got_fileindex_entry_get(fileindex, relpath) != NULL)
2289 		return NULL;
2290 
2291 	err = got_fileindex_entry_alloc(&ie, ondisk_path, relpath, NULL, NULL);
2292 	if (err)
2293 		return err;
2294 
2295 	err = got_fileindex_entry_add(fileindex, ie);
2296 	if (err) {
2297 		got_fileindex_entry_free(ie);
2298 		return err;
2299 	}
2300 
2301 	return report_file_status(ie, relpath, status_cb, status_arg, repo);
2302 }
2303 
2304 const struct got_error *
2305 got_worktree_schedule_add(struct got_worktree *worktree,
2306     struct got_pathlist_head *ondisk_paths,
2307     got_worktree_status_cb status_cb, void *status_arg,
2308     struct got_repository *repo)
2309 {
2310 	struct got_fileindex *fileindex = NULL;
2311 	char *fileindex_path = NULL;
2312 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2313 	struct got_pathlist_entry *pe;
2314 
2315 	err = lock_worktree(worktree, LOCK_EX);
2316 	if (err)
2317 		return err;
2318 
2319 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2320 	if (err)
2321 		goto done;
2322 
2323 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2324 		char *relpath;
2325 		err = got_path_skip_common_ancestor(&relpath,
2326 		    got_worktree_get_root_path(worktree), pe->path);
2327 		if (err)
2328 			break;
2329 		err = schedule_addition(pe->path, fileindex, relpath,
2330 		    status_cb, status_arg, repo);
2331 		free(relpath);
2332 		if (err)
2333 			break;
2334 	}
2335 	sync_err = sync_fileindex(fileindex, fileindex_path);
2336 	if (sync_err && err == NULL)
2337 		err = sync_err;
2338 done:
2339 	free(fileindex_path);
2340 	if (fileindex)
2341 		got_fileindex_free(fileindex);
2342 	unlockerr = lock_worktree(worktree, LOCK_SH);
2343 	if (unlockerr && err == NULL)
2344 		err = unlockerr;
2345 	return err;
2346 }
2347 
2348 static const struct got_error *
2349 schedule_for_deletion(const char *ondisk_path, struct got_fileindex *fileindex,
2350     const char *relpath, int delete_local_mods,
2351     got_worktree_status_cb status_cb, void *status_arg,
2352     struct got_repository *repo)
2353 {
2354 	const struct got_error *err = NULL;
2355 	struct got_fileindex_entry *ie = NULL;
2356 	unsigned char status;
2357 	struct stat sb;
2358 
2359 	ie = got_fileindex_entry_get(fileindex, relpath);
2360 	if (ie == NULL)
2361 		return got_error(GOT_ERR_BAD_PATH);
2362 
2363 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2364 	if (err)
2365 		return err;
2366 
2367 	if (status != GOT_STATUS_NO_CHANGE) {
2368 		if (status == GOT_STATUS_DELETE)
2369 			return got_error_set_errno(ENOENT, ondisk_path);
2370 		if (status != GOT_STATUS_MODIFY)
2371 			return got_error(GOT_ERR_FILE_STATUS);
2372 		if (!delete_local_mods)
2373 			return got_error(GOT_ERR_FILE_MODIFIED);
2374 	}
2375 
2376 	if (unlink(ondisk_path) != 0)
2377 		return got_error_from_errno2("unlink", ondisk_path);
2378 
2379 	got_fileindex_entry_mark_deleted_from_disk(ie);
2380 	return report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2381 }
2382 
2383 const struct got_error *
2384 got_worktree_schedule_delete(struct got_worktree *worktree,
2385     struct got_pathlist_head *ondisk_paths, int delete_local_mods,
2386     got_worktree_status_cb status_cb, void *status_arg,
2387     struct got_repository *repo)
2388 {
2389 	struct got_fileindex *fileindex = NULL;
2390 	char *fileindex_path = NULL;
2391 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2392 	struct got_pathlist_entry *pe;
2393 
2394 	err = lock_worktree(worktree, LOCK_EX);
2395 	if (err)
2396 		return err;
2397 
2398 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2399 	if (err)
2400 		goto done;
2401 
2402 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2403 		char *relpath;
2404 		err = got_path_skip_common_ancestor(&relpath,
2405 		    got_worktree_get_root_path(worktree), pe->path);
2406 		if (err)
2407 			break;
2408 		err = schedule_for_deletion(pe->path, fileindex, relpath,
2409 		    delete_local_mods, status_cb, status_arg, repo);
2410 		free(relpath);
2411 		if (err)
2412 			break;
2413 	}
2414 	sync_err = sync_fileindex(fileindex, fileindex_path);
2415 	if (sync_err && err == NULL)
2416 		err = sync_err;
2417 done:
2418 	free(fileindex_path);
2419 	if (fileindex)
2420 		got_fileindex_free(fileindex);
2421 	unlockerr = lock_worktree(worktree, LOCK_SH);
2422 	if (unlockerr && err == NULL)
2423 		err = unlockerr;
2424 	return err;
2425 }
2426 
2427 static const struct got_error *
2428 revert_file(struct got_worktree *worktree, struct got_fileindex *fileindex,
2429     const char *ondisk_path,
2430     got_worktree_checkout_cb progress_cb, void *progress_arg,
2431     struct got_repository *repo)
2432 {
2433 	const struct got_error *err = NULL;
2434 	char *relpath = NULL, *parent_path = NULL;
2435 	struct got_fileindex_entry *ie;
2436 	struct got_tree_object *tree = NULL;
2437 	struct got_object_id *tree_id = NULL;
2438 	const struct got_tree_entry *te;
2439 	char *tree_path = NULL, *te_name;
2440 	struct got_blob_object *blob = NULL;
2441 	unsigned char status;
2442 	struct stat sb;
2443 
2444 	err = got_path_skip_common_ancestor(&relpath,
2445 	    got_worktree_get_root_path(worktree), ondisk_path);
2446 	if (err)
2447 		goto done;
2448 
2449 	ie = got_fileindex_entry_get(fileindex, relpath);
2450 	if (ie == NULL) {
2451 		err = got_error(GOT_ERR_BAD_PATH);
2452 		goto done;
2453 	}
2454 
2455 	/* Construct in-repository path of tree which contains this blob. */
2456 	err = got_path_dirname(&parent_path, ie->path);
2457 	if (err) {
2458 		if (err->code != GOT_ERR_BAD_PATH)
2459 			goto done;
2460 		parent_path = strdup("/");
2461 		if (parent_path == NULL) {
2462 			err = got_error_from_errno("strdup");
2463 			goto done;
2464 		}
2465 	}
2466 	if (got_path_is_root_dir(worktree->path_prefix)) {
2467 		tree_path = strdup(parent_path);
2468 		if (tree_path == NULL) {
2469 			err = got_error_from_errno("strdup");
2470 			goto done;
2471 		}
2472 	} else {
2473 		if (got_path_is_root_dir(parent_path)) {
2474 			tree_path = strdup(worktree->path_prefix);
2475 			if (tree_path == NULL) {
2476 				err = got_error_from_errno("strdup");
2477 				goto done;
2478 			}
2479 		} else {
2480 			if (asprintf(&tree_path, "%s/%s",
2481 			    worktree->path_prefix, parent_path) == -1) {
2482 				err = got_error_from_errno("asprintf");
2483 				goto done;
2484 			}
2485 		}
2486 	}
2487 
2488 	err = got_object_id_by_path(&tree_id, repo, worktree->base_commit_id,
2489 	    tree_path);
2490 	if (err)
2491 		goto done;
2492 
2493 	err = got_object_open_as_tree(&tree, repo, tree_id);
2494 	if (err)
2495 		goto done;
2496 
2497 	te_name = basename(ie->path);
2498 	if (te_name == NULL) {
2499 		err = got_error_from_errno2("basename", ie->path);
2500 		goto done;
2501 	}
2502 
2503 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2504 	if (err)
2505 		goto done;
2506 
2507 	te = got_object_tree_find_entry(tree, te_name);
2508 	if (te == NULL && status != GOT_STATUS_ADD) {
2509 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
2510 		goto done;
2511 	}
2512 
2513 	switch (status) {
2514 	case GOT_STATUS_ADD:
2515 		(*progress_cb)(progress_arg, GOT_STATUS_REVERT, ie->path);
2516 		got_fileindex_entry_remove(fileindex, ie);
2517 		break;
2518 	case GOT_STATUS_DELETE:
2519 	case GOT_STATUS_MODIFY:
2520 	case GOT_STATUS_CONFLICT:
2521 	case GOT_STATUS_MISSING: {
2522 		struct got_object_id id;
2523 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2524 		err = got_object_open_as_blob(&blob, repo, &id, 8192);
2525 		if (err)
2526 			goto done;
2527 		err = install_blob(worktree, ondisk_path, ie->path,
2528 		    te->mode, sb.st_mode, blob, 0, 1, repo, progress_cb,
2529 		    progress_arg);
2530 		if (err)
2531 			goto done;
2532 		if (status == GOT_STATUS_DELETE) {
2533 			err = update_blob_fileindex_entry(worktree,
2534 			    fileindex, ie, ondisk_path, ie->path, blob, 1);
2535 			if (err)
2536 				goto done;
2537 		}
2538 		break;
2539 	}
2540 	default:
2541 			goto done;
2542 	}
2543 done:
2544 	free(relpath);
2545 	free(parent_path);
2546 	free(tree_path);
2547 	if (blob)
2548 		got_object_blob_close(blob);
2549 	if (tree)
2550 		got_object_tree_close(tree);
2551 	free(tree_id);
2552 	return err;
2553 }
2554 
2555 const struct got_error *
2556 got_worktree_revert(struct got_worktree *worktree,
2557     struct got_pathlist_head *ondisk_paths,
2558     got_worktree_checkout_cb progress_cb, void *progress_arg,
2559     struct got_repository *repo)
2560 {
2561 	struct got_fileindex *fileindex = NULL;
2562 	char *fileindex_path = NULL;
2563 	const struct got_error *err = NULL, *unlockerr = NULL;
2564 	const struct got_error *sync_err = NULL;
2565 	struct got_pathlist_entry *pe;
2566 
2567 	err = lock_worktree(worktree, LOCK_EX);
2568 	if (err)
2569 		return err;
2570 
2571 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2572 	if (err)
2573 		goto done;
2574 
2575 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2576 		err = revert_file(worktree, fileindex, pe->path,
2577 		    progress_cb, progress_arg, repo);
2578 		if (err)
2579 			break;
2580 	}
2581 	sync_err = sync_fileindex(fileindex, fileindex_path);
2582 	if (sync_err && err == NULL)
2583 		err = sync_err;
2584 done:
2585 	free(fileindex_path);
2586 	if (fileindex)
2587 		got_fileindex_free(fileindex);
2588 	unlockerr = lock_worktree(worktree, LOCK_SH);
2589 	if (unlockerr && err == NULL)
2590 		err = unlockerr;
2591 	return err;
2592 }
2593 
2594 static void
2595 free_commitable(struct got_commitable *ct)
2596 {
2597 	free(ct->path);
2598 	free(ct->in_repo_path);
2599 	free(ct->ondisk_path);
2600 	free(ct->blob_id);
2601 	free(ct->base_blob_id);
2602 	free(ct->base_commit_id);
2603 	free(ct);
2604 }
2605 
2606 struct collect_commitables_arg {
2607 	struct got_pathlist_head *commitable_paths;
2608 	struct got_repository *repo;
2609 	struct got_worktree *worktree;
2610 };
2611 
2612 static const struct got_error *
2613 collect_commitables(void *arg, unsigned char status, const char *relpath,
2614     struct got_object_id *blob_id, struct got_object_id *commit_id)
2615 {
2616 	struct collect_commitables_arg *a = arg;
2617 	const struct got_error *err = NULL;
2618 	struct got_commitable *ct = NULL;
2619 	struct got_pathlist_entry *new = NULL;
2620 	char *parent_path = NULL, *path = NULL;
2621 	struct stat sb;
2622 
2623 	if (status == GOT_STATUS_CONFLICT)
2624 		return got_error(GOT_ERR_COMMIT_CONFLICT);
2625 
2626 	if (status != GOT_STATUS_MODIFY && status != GOT_STATUS_ADD &&
2627 	    status != GOT_STATUS_DELETE)
2628 		return NULL;
2629 
2630 	if (asprintf(&path, "/%s", relpath) == -1) {
2631 		err = got_error_from_errno("asprintf");
2632 		goto done;
2633 	}
2634 	if (strcmp(path, "/") == 0) {
2635 		parent_path = strdup("");
2636 		if (parent_path == NULL)
2637 			return got_error_from_errno("strdup");
2638 	} else {
2639 		err = got_path_dirname(&parent_path, path);
2640 		if (err)
2641 			return err;
2642 	}
2643 
2644 	ct = calloc(1, sizeof(*ct));
2645 	if (ct == NULL) {
2646 		err = got_error_from_errno("calloc");
2647 		goto done;
2648 	}
2649 
2650 	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
2651 	    relpath) == -1) {
2652 		err = got_error_from_errno("asprintf");
2653 		goto done;
2654 	}
2655 	if (status == GOT_STATUS_DELETE) {
2656 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
2657 	} else {
2658 		if (lstat(ct->ondisk_path, &sb) != 0) {
2659 			err = got_error_from_errno2("lstat", ct->ondisk_path);
2660 			goto done;
2661 		}
2662 		ct->mode = sb.st_mode;
2663 	}
2664 
2665 	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
2666 	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
2667 	    relpath) == -1) {
2668 		err = got_error_from_errno("asprintf");
2669 		goto done;
2670 	}
2671 
2672 	ct->status = status;
2673 	ct->blob_id = NULL; /* will be filled in when blob gets created */
2674 	if (ct->status != GOT_STATUS_ADD) {
2675 		ct->base_blob_id = got_object_id_dup(blob_id);
2676 		if (ct->base_blob_id == NULL) {
2677 			err = got_error_from_errno("got_object_id_dup");
2678 			goto done;
2679 		}
2680 		ct->base_commit_id = got_object_id_dup(commit_id);
2681 		if (ct->base_commit_id == NULL) {
2682 			err = got_error_from_errno("got_object_id_dup");
2683 			goto done;
2684 		}
2685 	}
2686 	ct->path = strdup(path);
2687 	if (ct->path == NULL) {
2688 		err = got_error_from_errno("strdup");
2689 		goto done;
2690 	}
2691 	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
2692 done:
2693 	if (ct && (err || new == NULL))
2694 		free_commitable(ct);
2695 	free(parent_path);
2696 	free(path);
2697 	return err;
2698 }
2699 
2700 static const struct got_error *write_tree(struct got_object_id **,
2701     struct got_tree_object *, const char *, struct got_pathlist_head *,
2702     got_worktree_status_cb status_cb, void *status_arg,
2703     struct got_repository *);
2704 
2705 static const struct got_error *
2706 write_subtree(struct got_object_id **new_subtree_id,
2707     struct got_tree_entry *te, const char *parent_path,
2708     struct got_pathlist_head *commitable_paths,
2709     got_worktree_status_cb status_cb, void *status_arg,
2710     struct got_repository *repo)
2711 {
2712 	const struct got_error *err = NULL;
2713 	struct got_tree_object *subtree;
2714 	char *subpath;
2715 
2716 	if (asprintf(&subpath, "%s%s%s", parent_path,
2717 	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
2718 		return got_error_from_errno("asprintf");
2719 
2720 	err = got_object_open_as_tree(&subtree, repo, te->id);
2721 	if (err)
2722 		return err;
2723 
2724 	err = write_tree(new_subtree_id, subtree, subpath, commitable_paths,
2725 	    status_cb, status_arg, repo);
2726 	got_object_tree_close(subtree);
2727 	free(subpath);
2728 	return err;
2729 }
2730 
2731 static const struct got_error *
2732 match_ct_parent_path(int *match, struct got_commitable *ct, const char *path)
2733 {
2734 	const struct got_error *err = NULL;
2735 	char *ct_parent_path = NULL;
2736 
2737 	*match = 0;
2738 
2739 	if (strchr(ct->path, '/') == NULL) {
2740 		*match = got_path_is_root_dir(path);
2741 		return NULL;
2742 	}
2743 
2744 	err = got_path_dirname(&ct_parent_path, ct->path);
2745 	if (err)
2746 		return err;
2747 	*match = (strcmp(path, ct_parent_path) == 0);
2748 	free(ct_parent_path);
2749 	return err;
2750 }
2751 
2752 static mode_t
2753 get_ct_file_mode(struct got_commitable *ct)
2754 {
2755 	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
2756 }
2757 
2758 static const struct got_error *
2759 alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
2760     struct got_tree_entry *te, struct got_commitable *ct)
2761 {
2762 	const struct got_error *err = NULL;
2763 
2764 	*new_te = NULL;
2765 
2766 	err = got_object_tree_entry_dup(new_te, te);
2767 	if (err)
2768 		goto done;
2769 
2770 	(*new_te)->mode = get_ct_file_mode(ct);
2771 
2772 	free((*new_te)->id);
2773 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2774 	if ((*new_te)->id == NULL) {
2775 		err = got_error_from_errno("got_object_id_dup");
2776 		goto done;
2777 	}
2778 done:
2779 	if (err && *new_te) {
2780 		got_object_tree_entry_close(*new_te);
2781 		*new_te = NULL;
2782 	}
2783 	return err;
2784 }
2785 
2786 static const struct got_error *
2787 alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
2788     struct got_commitable *ct)
2789 {
2790 	const struct got_error *err = NULL;
2791 	char *ct_name;
2792 
2793 	 *new_te = NULL;
2794 
2795 	*new_te = calloc(1, sizeof(**new_te));
2796 	if (*new_te == NULL)
2797 		return got_error_from_errno("calloc");
2798 
2799 	ct_name = basename(ct->path);
2800 	if (ct_name == NULL) {
2801 		err = got_error_from_errno2("basename", ct->path);
2802 		goto done;
2803 	}
2804 	(*new_te)->name = strdup(ct_name);
2805 	if ((*new_te)->name == NULL) {
2806 		err = got_error_from_errno("strdup");
2807 		goto done;
2808 	}
2809 
2810 	(*new_te)->mode = get_ct_file_mode(ct);
2811 
2812 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2813 	if ((*new_te)->id == NULL) {
2814 		err = got_error_from_errno("got_object_id_dup");
2815 		goto done;
2816 	}
2817 done:
2818 	if (err && *new_te) {
2819 		got_object_tree_entry_close(*new_te);
2820 		*new_te = NULL;
2821 	}
2822 	return err;
2823 }
2824 
2825 static const struct got_error *
2826 insert_tree_entry(struct got_tree_entry *new_te,
2827     struct got_pathlist_head *paths)
2828 {
2829 	const struct got_error *err = NULL;
2830 	struct got_pathlist_entry *new_pe;
2831 
2832 	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
2833 	if (err)
2834 		return err;
2835 	if (new_pe == NULL)
2836 		return got_error(GOT_ERR_TREE_DUP_ENTRY);
2837 	return NULL;
2838 }
2839 
2840 static const struct got_error *
2841 report_ct_status(struct got_commitable *ct,
2842     got_worktree_status_cb status_cb, void *status_arg)
2843 {
2844 	const char *ct_path = ct->path;
2845 	while (ct_path[0] == '/')
2846 		ct_path++;
2847 	return (*status_cb)(status_arg, ct->status, ct_path, ct->blob_id, NULL);
2848 }
2849 
2850 static const struct got_error *
2851 match_modified_subtree(int *modified, struct got_tree_entry *te,
2852     const char *base_tree_path, struct got_pathlist_head *commitable_paths)
2853 {
2854 	const struct got_error *err = NULL;
2855 	struct got_pathlist_entry *pe;
2856 	char *te_path;
2857 
2858 	*modified = 0;
2859 
2860 	if (asprintf(&te_path, "%s%s%s", base_tree_path,
2861 	    got_path_is_root_dir(base_tree_path) ? "" : "/",
2862 	    te->name) == -1)
2863 		return got_error_from_errno("asprintf");
2864 
2865 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2866 		struct got_commitable *ct = pe->data;
2867 		*modified = got_path_is_child(ct->in_repo_path, te_path,
2868 		    strlen(te_path));
2869 		 if (*modified)
2870 			break;
2871 	}
2872 
2873 	free(te_path);
2874 	return err;
2875 }
2876 
2877 static const struct got_error *
2878 match_deleted_or_modified_ct(struct got_commitable **ctp,
2879     struct got_tree_entry *te, const char *base_tree_path,
2880     struct got_pathlist_head *commitable_paths)
2881 {
2882 	const struct got_error *err = NULL;
2883 	struct got_pathlist_entry *pe;
2884 
2885 	*ctp = NULL;
2886 
2887 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2888 		struct got_commitable *ct = pe->data;
2889 		char *ct_name = NULL;
2890 		int path_matches;
2891 
2892 		if (ct->status != GOT_STATUS_MODIFY &&
2893 		    ct->status != GOT_STATUS_DELETE)
2894 			continue;
2895 
2896 		if (got_object_id_cmp(ct->base_blob_id, te->id) != 0)
2897 			continue;
2898 
2899 		 err = match_ct_parent_path(&path_matches, ct, base_tree_path);
2900 		 if (err)
2901 			return err;
2902 		if (!path_matches)
2903 			continue;
2904 
2905 		ct_name = basename(pe->path);
2906 		if (ct_name == NULL)
2907 			return got_error_from_errno2("basename", pe->path);
2908 
2909 		if (strcmp(te->name, ct_name) != 0)
2910 			continue;
2911 
2912 		*ctp = ct;
2913 		break;
2914 	}
2915 
2916 	return err;
2917 }
2918 
2919 static const struct got_error *
2920 make_subtree_for_added_blob(struct got_tree_entry **new_tep,
2921     const char *child_path, const char *path_base_tree,
2922     struct got_pathlist_head *commitable_paths,
2923     got_worktree_status_cb status_cb, void *status_arg,
2924     struct got_repository *repo)
2925 {
2926 	const struct got_error *err = NULL;
2927 	struct got_tree_entry *new_te;
2928 	char *subtree_path;
2929 
2930 	*new_tep = NULL;
2931 
2932 	if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
2933 	    got_path_is_root_dir(path_base_tree) ? "" : "/",
2934 	    child_path) == -1)
2935 		return got_error_from_errno("asprintf");
2936 
2937 	new_te = calloc(1, sizeof(*new_te));
2938 	new_te->mode = S_IFDIR;
2939 	new_te->name = strdup(child_path);
2940 	if (new_te->name == NULL) {
2941 		err = got_error_from_errno("strdup");
2942 		got_object_tree_entry_close(new_te);
2943 		goto done;
2944 	}
2945 	err = write_tree(&new_te->id, NULL, subtree_path,
2946 	    commitable_paths, status_cb, status_arg, repo);
2947 	if (err) {
2948 		got_object_tree_entry_close(new_te);
2949 		goto done;
2950 	}
2951 done:
2952 	free(subtree_path);
2953 	if (err == NULL)
2954 		*new_tep = new_te;
2955 	return err;
2956 }
2957 
2958 static const struct got_error *
2959 write_tree(struct got_object_id **new_tree_id,
2960     struct got_tree_object *base_tree, const char *path_base_tree,
2961     struct got_pathlist_head *commitable_paths,
2962     got_worktree_status_cb status_cb, void *status_arg,
2963     struct got_repository *repo)
2964 {
2965 	const struct got_error *err = NULL;
2966 	const struct got_tree_entries *base_entries = NULL;
2967 	struct got_pathlist_head paths;
2968 	struct got_tree_entries new_tree_entries;
2969 	struct got_tree_entry *te, *new_te = NULL;
2970 	struct got_pathlist_entry *pe;
2971 
2972 	TAILQ_INIT(&paths);
2973 	new_tree_entries.nentries = 0;
2974 	SIMPLEQ_INIT(&new_tree_entries.head);
2975 
2976 	/* Insert, and recurse into, newly added entries first. */
2977 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2978 		struct got_commitable *ct = pe->data;
2979 		char *child_path = NULL, *slash;
2980 
2981 		if (ct->status != GOT_STATUS_ADD ||
2982 		    (ct->flags & GOT_COMMITABLE_ADDED))
2983 			continue;
2984 
2985 		 if (!got_path_is_child(pe->path, path_base_tree,
2986 		     strlen(path_base_tree)))
2987 			continue;
2988 
2989 		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
2990 		    pe->path);
2991 		if (err)
2992 			goto done;
2993 
2994 		slash = strchr(child_path, '/');
2995 		if (slash == NULL) {
2996 			err = alloc_added_blob_tree_entry(&new_te, ct);
2997 			if (err)
2998 				goto done;
2999 			err = report_ct_status(ct, status_cb, status_arg);
3000 			if (err)
3001 				goto done;
3002 			ct->flags |= GOT_COMMITABLE_ADDED;
3003 			err = insert_tree_entry(new_te, &paths);
3004 			if (err)
3005 				goto done;
3006 		} else {
3007 			*slash = '\0'; /* trim trailing path components */
3008 			if (base_tree == NULL ||
3009 			    got_object_tree_find_entry(base_tree, child_path)
3010 			    == NULL) {
3011 				err = make_subtree_for_added_blob(&new_te,
3012 				    child_path, path_base_tree,
3013 				    commitable_paths, status_cb, status_arg,
3014 				    repo);
3015 				if (err)
3016 					goto done;
3017 				err = insert_tree_entry(new_te, &paths);
3018 				if (err)
3019 					goto done;
3020 			}
3021 		}
3022 	}
3023 
3024 	if (base_tree) {
3025 		/* Handle modified and deleted entries. */
3026 		base_entries = got_object_tree_get_entries(base_tree);
3027 		SIMPLEQ_FOREACH(te, &base_entries->head, entry) {
3028 			struct got_commitable *ct = NULL;
3029 
3030 			if (S_ISDIR(te->mode)) {
3031 				int modified;
3032 				err = got_object_tree_entry_dup(&new_te, te);
3033 				if (err)
3034 					goto done;
3035 				err = match_modified_subtree(&modified, te,
3036 				    path_base_tree, commitable_paths);
3037 				if (err)
3038 					goto done;
3039 				/* Avoid recursion into unmodified subtrees. */
3040 				if (modified) {
3041 					free(new_te->id);
3042 					err = write_subtree(&new_te->id, te,
3043 					    path_base_tree, commitable_paths,
3044 					    status_cb, status_arg, repo);
3045 					if (err)
3046 						goto done;
3047 				}
3048 				err = insert_tree_entry(new_te, &paths);
3049 				if (err)
3050 					goto done;
3051 				continue;
3052 			}
3053 
3054 			err = match_deleted_or_modified_ct(&ct, te,
3055 			    path_base_tree, commitable_paths);
3056 			if (ct) {
3057 				/* NB: Deleted entries get dropped here. */
3058 				if (ct->status == GOT_STATUS_MODIFY) {
3059 					err = alloc_modified_blob_tree_entry(
3060 					    &new_te, te, ct);
3061 					if (err)
3062 						goto done;
3063 					err = insert_tree_entry(new_te, &paths);
3064 					if (err)
3065 						goto done;
3066 				}
3067 				err = report_ct_status(ct, status_cb,
3068 				    status_arg);
3069 				if (err)
3070 					goto done;
3071 			} else {
3072 				/* Entry is unchanged; just copy it. */
3073 				err = got_object_tree_entry_dup(&new_te, te);
3074 				if (err)
3075 					goto done;
3076 				err = insert_tree_entry(new_te, &paths);
3077 				if (err)
3078 					goto done;
3079 			}
3080 		}
3081 	}
3082 
3083 	/* Write new list of entries; deleted entries have been dropped. */
3084 	TAILQ_FOREACH(pe, &paths, entry) {
3085 		struct got_tree_entry *te = pe->data;
3086 		new_tree_entries.nentries++;
3087 		SIMPLEQ_INSERT_TAIL(&new_tree_entries.head, te, entry);
3088 	}
3089 	err = got_object_tree_create(new_tree_id, &new_tree_entries, repo);
3090 done:
3091 	got_object_tree_entries_close(&new_tree_entries);
3092 	got_pathlist_free(&paths);
3093 	return err;
3094 }
3095 
3096 static const struct got_error *
3097 update_fileindex_after_commit(struct got_pathlist_head *commitable_paths,
3098     struct got_object_id *new_base_commit_id, struct got_fileindex *fileindex)
3099 {
3100 	const struct got_error *err = NULL;
3101 	struct got_pathlist_entry *pe;
3102 
3103 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3104 		struct got_fileindex_entry *ie;
3105 		struct got_commitable *ct = pe->data;
3106 
3107 		ie = got_fileindex_entry_get(fileindex, pe->path);
3108 		if (ie) {
3109 			if (ct->status == GOT_STATUS_DELETE) {
3110 				got_fileindex_entry_remove(fileindex, ie);
3111 				got_fileindex_entry_free(ie);
3112 			} else
3113 				err = got_fileindex_entry_update(ie,
3114 				    ct->ondisk_path, ct->blob_id->sha1,
3115 				    new_base_commit_id->sha1, 1);
3116 		} else {
3117 			err = got_fileindex_entry_alloc(&ie,
3118 			    ct->ondisk_path, pe->path, ct->blob_id->sha1,
3119 			    new_base_commit_id->sha1);
3120 			if (err)
3121 				break;
3122 			err = got_fileindex_entry_add(fileindex, ie);
3123 			if (err)
3124 				break;
3125 		}
3126 	}
3127 	return err;
3128 }
3129 
3130 static const struct got_error *
3131 check_ct_out_of_date(struct got_commitable *ct, struct got_repository *repo,
3132 	struct got_object_id *head_commit_id)
3133 {
3134 	const struct got_error *err = NULL;
3135 	struct got_object_id *id_in_head = NULL, *id = NULL;
3136 	struct got_commit_object *commit = NULL;
3137 	char *path = NULL;
3138 	const char *ct_path = ct->in_repo_path;
3139 
3140 	while (ct_path[0] == '/')
3141 		ct_path++;
3142 
3143 	/*
3144 	 * Ensure that no modifications were made to files *and their parents*
3145 	 * in commits between the file's base commit and the branch head.
3146 	 *
3147 	 * Checking the parents is important for detecting conflicting tree
3148 	 * configurations (files or parent folders might have been moved,
3149 	 * deleted, added again, etc.). Such changes need to be merged with
3150 	 * local changes before a commit can occur.
3151 	 *
3152 	 * The implication is that the file's (parent) entry in the root
3153 	 * directory must have the same ID in all relevant commits.
3154 	 */
3155 	if (ct->status != GOT_STATUS_ADD) {
3156 		struct got_object_qid *pid;
3157 		char *slash;
3158 		struct got_object_id *root_entry_id = NULL;
3159 
3160 		/* Trivial case: base commit == head commit */
3161 		if (got_object_id_cmp(ct->base_commit_id, head_commit_id) == 0)
3162 			return NULL;
3163 
3164 		/* Compute the path to the root directory's entry. */
3165 		path = strdup(ct_path);
3166 		if (path == NULL) {
3167 			err = got_error_from_errno("strdup");
3168 			goto done;
3169 		}
3170 		slash = strchr(path, '/');
3171 		if (slash)
3172 			*slash = '\0';
3173 
3174 		err = got_object_open_as_commit(&commit, repo, head_commit_id);
3175 		if (err)
3176 			goto done;
3177 
3178 		err = got_object_id_by_path(&root_entry_id, repo,
3179 		    head_commit_id, path);
3180 		if (err)
3181 			goto done;
3182 
3183 		pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(commit));
3184 		while (pid) {
3185 			struct got_commit_object *pcommit;
3186 
3187 			err = got_object_id_by_path(&id, repo, pid->id, path);
3188 			if (err) {
3189 				if (err->code != GOT_ERR_NO_TREE_ENTRY)
3190 					goto done;
3191 				err = NULL;
3192 				break;
3193 			}
3194 
3195 			err = got_object_id_by_path(&id, repo, pid->id, path);
3196 			if (err)
3197 				goto done;
3198 
3199 			if (got_object_id_cmp(id, root_entry_id) != 0) {
3200 				err = got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3201 				break;
3202 			}
3203 
3204 			if (got_object_id_cmp(pid->id, ct->base_commit_id) == 0)
3205 				break; /* all relevant commits scanned */
3206 
3207 			err = got_object_open_as_commit(&pcommit, repo,
3208 			    pid->id);
3209 			if (err)
3210 				goto done;
3211 
3212 			got_object_commit_close(commit);
3213 			commit = pcommit;
3214 			pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(
3215 			    commit));
3216 		}
3217 	} else {
3218 		/* Require that added files don't exist in the branch head. */
3219 		err = got_object_id_by_path(&id_in_head, repo, head_commit_id,
3220 		    ct_path);
3221 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
3222 			goto done;
3223 		err = id_in_head ? got_error(GOT_ERR_COMMIT_OUT_OF_DATE) : NULL;
3224 	}
3225 done:
3226 	if (commit)
3227 		got_object_commit_close(commit);
3228 	free(id_in_head);
3229 	free(id);
3230 	free(path);
3231 	return err;
3232 }
3233 
3234 const struct got_error *
3235 commit_worktree(struct got_object_id **new_commit_id,
3236     struct got_pathlist_head *commitable_paths,
3237     struct got_object_id *head_commit_id, struct got_worktree *worktree,
3238     const char *ondisk_path, const char *author, const char *committer,
3239     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3240     got_worktree_status_cb status_cb, void *status_arg,
3241     struct got_repository *repo)
3242 {
3243 	const struct got_error *err = NULL, *unlockerr = NULL;
3244 	struct got_pathlist_entry *pe;
3245 	const char *head_ref_name = NULL;
3246 	struct got_commit_object *head_commit = NULL;
3247 	struct got_reference *head_ref2 = NULL;
3248 	struct got_object_id *head_commit_id2 = NULL;
3249 	struct got_tree_object *head_tree = NULL;
3250 	struct got_object_id *new_tree_id = NULL;
3251 	struct got_object_id_queue parent_ids;
3252 	struct got_object_qid *pid = NULL;
3253 	char *logmsg = NULL;
3254 
3255 	*new_commit_id = NULL;
3256 
3257 	SIMPLEQ_INIT(&parent_ids);
3258 
3259 	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
3260 	if (err)
3261 		goto done;
3262 
3263 	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
3264 	if (err)
3265 		goto done;
3266 
3267 	if (commit_msg_cb != NULL) {
3268 		err = commit_msg_cb(commitable_paths, &logmsg, commit_arg);
3269 		if (err)
3270 			goto done;
3271 	}
3272 
3273 	if (logmsg == NULL || strlen(logmsg) == 0) {
3274 		err = got_error(GOT_ERR_COMMIT_MSG_EMPTY);
3275 		goto done;
3276 	}
3277 
3278 	/* Create blobs from added and modified files and record their IDs. */
3279 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3280 		struct got_commitable *ct = pe->data;
3281 		char *ondisk_path;
3282 
3283 		if (ct->status != GOT_STATUS_ADD &&
3284 		    ct->status != GOT_STATUS_MODIFY)
3285 			continue;
3286 
3287 		if (asprintf(&ondisk_path, "%s/%s",
3288 		    worktree->root_path, pe->path) == -1) {
3289 			err = got_error_from_errno("asprintf");
3290 			goto done;
3291 		}
3292 		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
3293 		free(ondisk_path);
3294 		if (err)
3295 			goto done;
3296 	}
3297 
3298 	/* Recursively write new tree objects. */
3299 	err = write_tree(&new_tree_id, head_tree, "/", commitable_paths,
3300 	    status_cb, status_arg, repo);
3301 	if (err)
3302 		goto done;
3303 
3304 	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
3305 	if (err)
3306 		goto done;
3307 	SIMPLEQ_INSERT_TAIL(&parent_ids, pid, entry);
3308 	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
3309 	    1, author, time(NULL), committer, time(NULL), logmsg, repo);
3310 	got_object_qid_free(pid);
3311 	if (logmsg != NULL)
3312 		free(logmsg);
3313 	if (err)
3314 		goto done;
3315 
3316 	/* Check if a concurrent commit to our branch has occurred. */
3317 	head_ref_name = got_worktree_get_head_ref_name(worktree);
3318 	if (head_ref_name == NULL) {
3319 		err = got_error_from_errno("got_worktree_get_head_ref_name");
3320 		goto done;
3321 	}
3322 	/* Lock the reference here to prevent concurrent modification. */
3323 	err = got_ref_open(&head_ref2, repo, head_ref_name, 1);
3324 	if (err)
3325 		goto done;
3326 	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
3327 	if (err)
3328 		goto done;
3329 	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
3330 		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
3331 		goto done;
3332 	}
3333 	/* Update branch head in repository. */
3334 	err = got_ref_change_ref(head_ref2, *new_commit_id);
3335 	if (err)
3336 		goto done;
3337 	err = got_ref_write(head_ref2, repo);
3338 	if (err)
3339 		goto done;
3340 
3341 	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
3342 	if (err)
3343 		goto done;
3344 
3345 	err = ref_base_commit(worktree, repo);
3346 	if (err)
3347 		goto done;
3348 done:
3349 	if (head_tree)
3350 		got_object_tree_close(head_tree);
3351 	if (head_commit)
3352 		got_object_commit_close(head_commit);
3353 	free(head_commit_id2);
3354 	if (head_ref2) {
3355 		unlockerr = got_ref_unlock(head_ref2);
3356 		if (unlockerr && err == NULL)
3357 			err = unlockerr;
3358 		got_ref_close(head_ref2);
3359 	}
3360 	return err;
3361 }
3362 
3363 const struct got_error *
3364 got_worktree_commit(struct got_object_id **new_commit_id,
3365     struct got_worktree *worktree, const char *ondisk_path,
3366     const char *author, const char *committer,
3367     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3368     got_worktree_status_cb status_cb, void *status_arg,
3369     struct got_repository *repo)
3370 {
3371 	const struct got_error *err = NULL, *unlockerr = NULL, *sync_err;
3372 	struct got_fileindex *fileindex = NULL;
3373 	char *fileindex_path = NULL, *relpath = NULL;
3374 	struct got_pathlist_head commitable_paths;
3375 	struct collect_commitables_arg cc_arg;
3376 	struct got_pathlist_entry *pe;
3377 	struct got_reference *head_ref = NULL;
3378 	struct got_object_id *head_commit_id = NULL;
3379 
3380 	*new_commit_id = NULL;
3381 
3382 	TAILQ_INIT(&commitable_paths);
3383 
3384 	err = lock_worktree(worktree, LOCK_EX);
3385 	if (err)
3386 		goto done;
3387 
3388 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3389 	if (err)
3390 		goto done;
3391 
3392 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3393 	if (err)
3394 		goto done;
3395 
3396 	if (ondisk_path) {
3397 		err = got_path_skip_common_ancestor(&relpath,
3398 		    worktree->root_path, ondisk_path);
3399 		if (err)
3400 			return err;
3401 	}
3402 
3403 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3404 	if (err)
3405 		goto done;
3406 
3407 	cc_arg.commitable_paths = &commitable_paths;
3408 	cc_arg.worktree = worktree;
3409 	cc_arg.repo = repo;
3410 	err = worktree_status(worktree, relpath ? relpath : "",
3411 	    fileindex, repo, collect_commitables, &cc_arg, NULL, NULL);
3412 	if (err)
3413 		goto done;
3414 
3415 	if (TAILQ_EMPTY(&commitable_paths)) {
3416 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3417 		goto done;
3418 	}
3419 
3420 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3421 		struct got_commitable *ct = pe->data;
3422 		err = check_ct_out_of_date(ct, repo, head_commit_id);
3423 		if (err)
3424 			goto done;
3425 	}
3426 
3427 	err = commit_worktree(new_commit_id, &commitable_paths,
3428 	    head_commit_id, worktree, ondisk_path, author, committer,
3429 	    commit_msg_cb, commit_arg, status_cb, status_arg, repo);
3430 	if (err)
3431 		goto done;
3432 
3433 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
3434 	    fileindex);
3435 	sync_err = sync_fileindex(fileindex, fileindex_path);
3436 	if (sync_err && err == NULL)
3437 		err = sync_err;
3438 done:
3439 	if (fileindex)
3440 		got_fileindex_free(fileindex);
3441 	free(fileindex_path);
3442 	free(relpath);
3443 	unlockerr = lock_worktree(worktree, LOCK_SH);
3444 	if (unlockerr && err == NULL)
3445 		err = unlockerr;
3446 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3447 		struct got_commitable *ct = pe->data;
3448 		free_commitable(ct);
3449 	}
3450 	got_pathlist_free(&commitable_paths);
3451 	return err;
3452 }
3453 
3454 const char *
3455 got_commitable_get_path(struct got_commitable *ct)
3456 {
3457 	return ct->path;
3458 }
3459 
3460 unsigned int
3461 got_commitable_get_status(struct got_commitable *ct)
3462 {
3463 	return ct->status;
3464 }
3465 
3466 struct check_rebase_ok_arg {
3467 	struct got_worktree *worktree;
3468 	struct got_repository *repo;
3469 	int rebase_in_progress;
3470 };
3471 
3472 static const struct got_error *
3473 check_rebase_ok(void *arg, struct got_fileindex_entry *ie)
3474 {
3475 	const struct got_error *err = NULL;
3476 	struct check_rebase_ok_arg *a = arg;
3477 	unsigned char status;
3478 	struct stat sb;
3479 	char *ondisk_path;
3480 
3481 	if (!a->rebase_in_progress) {
3482 		/* Reject rebase of a work tree with mixed base commits. */
3483 		if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
3484 		    SHA1_DIGEST_LENGTH))
3485 			return got_error(GOT_ERR_MIXED_COMMITS);
3486 	}
3487 
3488 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
3489 	    == -1)
3490 		return got_error_from_errno("asprintf");
3491 
3492 	/* Reject rebase of a work tree with modified or conflicted files. */
3493 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
3494 	free(ondisk_path);
3495 	if (err)
3496 		return err;
3497 
3498 	if (a->rebase_in_progress) {
3499 		if (status == GOT_STATUS_CONFLICT)
3500 			return got_error(GOT_ERR_CONFLICTS);
3501 	} else if (status != GOT_STATUS_NO_CHANGE)
3502 		return got_error(GOT_ERR_MODIFIED);
3503 
3504 	return NULL;
3505 }
3506 
3507 const struct got_error *
3508 got_worktree_rebase_prepare(struct got_reference **new_base_branch_ref,
3509     struct got_reference **tmp_branch, struct got_worktree *worktree,
3510     struct got_reference *branch, struct got_repository *repo)
3511 {
3512 	const struct got_error *err = NULL;
3513 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
3514 	char *branch_ref_name = NULL;
3515 	struct got_fileindex *fileindex = NULL;
3516 	char *fileindex_path = NULL;
3517 	struct check_rebase_ok_arg ok_arg;
3518 	struct got_reference *wt_branch = NULL, *branch_ref = NULL;
3519 
3520 	*new_base_branch_ref = NULL;
3521 	*tmp_branch = NULL;
3522 
3523 	err = lock_worktree(worktree, LOCK_EX);
3524 	if (err)
3525 		return err;
3526 
3527 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3528 	if (err)
3529 		goto done;
3530 
3531 	ok_arg.worktree = worktree;
3532 	ok_arg.repo = repo;
3533 	ok_arg.rebase_in_progress = 0;
3534 	err = got_fileindex_for_each_entry_safe(fileindex, check_rebase_ok,
3535 	    &ok_arg);
3536 	if (err)
3537 		goto done;
3538 
3539 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3540 	if (err)
3541 		goto done;
3542 
3543 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3544 	if (err)
3545 		goto done;
3546 
3547 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3548 	if (err)
3549 		goto done;
3550 
3551 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
3552 	    0);
3553 	if (err)
3554 		goto done;
3555 
3556 	err = got_ref_alloc_symref(new_base_branch_ref,
3557 	    new_base_branch_ref_name, wt_branch);
3558 	if (err)
3559 		goto done;
3560 	err = got_ref_write(*new_base_branch_ref, repo);
3561 	if (err)
3562 		goto done;
3563 
3564 	/* TODO Lock original branch's ref while rebasing? */
3565 
3566 	err = got_ref_alloc_symref(&branch_ref, branch_ref_name, branch);
3567 	if (err)
3568 		goto done;
3569 
3570 	err = got_ref_write(branch_ref, repo);
3571 	if (err)
3572 		goto done;
3573 
3574 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
3575 	    worktree->base_commit_id);
3576 	if (err)
3577 		goto done;
3578 	err = got_ref_write(*tmp_branch, repo);
3579 	if (err)
3580 		goto done;
3581 
3582 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
3583 	if (err)
3584 		goto done;
3585 done:
3586 	free(fileindex_path);
3587 	if (fileindex)
3588 		got_fileindex_free(fileindex);
3589 	free(tmp_branch_name);
3590 	free(new_base_branch_ref_name);
3591 	free(branch_ref_name);
3592 	if (branch_ref)
3593 		got_ref_close(branch_ref);
3594 	if (wt_branch)
3595 		got_ref_close(wt_branch);
3596 	if (err) {
3597 		if (*new_base_branch_ref) {
3598 			got_ref_close(*new_base_branch_ref);
3599 			*new_base_branch_ref = NULL;
3600 		}
3601 		if (*tmp_branch) {
3602 			got_ref_close(*tmp_branch);
3603 			*tmp_branch = NULL;
3604 		}
3605 		lock_worktree(worktree, LOCK_SH);
3606 	}
3607 	return err;
3608 }
3609 
3610 const struct got_error *
3611 got_worktree_rebase_continue(struct got_object_id **commit_id,
3612     struct got_reference **new_base_branch, struct got_reference **tmp_branch,
3613     struct got_reference **branch, struct got_worktree *worktree,
3614     struct got_repository *repo)
3615 {
3616 	const struct got_error *err;
3617 	char *commit_ref_name = NULL, *new_base_branch_ref_name = NULL;
3618 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
3619 	struct got_reference *commit_ref = NULL, *branch_ref = NULL;
3620 
3621 	*commit_id = NULL;
3622 
3623 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3624 	if (err)
3625 		return err;
3626 
3627 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3628 	if (err)
3629 		goto done;
3630 
3631 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3632 	if (err)
3633 		goto done;
3634 
3635 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3636 	if (err)
3637 		goto done;
3638 
3639 	err = got_ref_open(&branch_ref, repo, branch_ref_name, 0);
3640 	if (err)
3641 		goto done;
3642 
3643 	err = got_ref_open(branch, repo,
3644 	    got_ref_get_symref_target(branch_ref), 0);
3645 	if (err)
3646 		goto done;
3647 
3648 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3649 	if (err)
3650 		goto done;
3651 
3652 	err = got_ref_resolve(commit_id, repo, commit_ref);
3653 	if (err)
3654 		goto done;
3655 
3656 	err = got_ref_open(new_base_branch, repo,
3657 	    new_base_branch_ref_name, 0);
3658 	if (err)
3659 		goto done;
3660 
3661 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
3662 	if (err)
3663 		goto done;
3664 done:
3665 	free(commit_ref_name);
3666 	free(branch_ref_name);
3667 	if (commit_ref)
3668 		got_ref_close(commit_ref);
3669 	if (branch_ref)
3670 		got_ref_close(branch_ref);
3671 	if (err) {
3672 		free(*commit_id);
3673 		*commit_id = NULL;
3674 		if (*tmp_branch) {
3675 			got_ref_close(*tmp_branch);
3676 			*tmp_branch = NULL;
3677 		}
3678 		if (*new_base_branch) {
3679 			got_ref_close(*new_base_branch);
3680 			*new_base_branch = NULL;
3681 		}
3682 		if (*branch) {
3683 			got_ref_close(*branch);
3684 			*branch = NULL;
3685 		}
3686 	}
3687 	return err;
3688 }
3689 
3690 const struct got_error *
3691 got_worktree_rebase_in_progress(int *in_progress, struct got_worktree *worktree)
3692 {
3693 	const struct got_error *err;
3694 	char *tmp_branch_name = NULL;
3695 
3696 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3697 	if (err)
3698 		return err;
3699 
3700 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
3701 	free(tmp_branch_name);
3702 	return NULL;
3703 }
3704 
3705 static const struct got_error *
3706 collect_rebase_commit_msg(struct got_pathlist_head *commitable_paths,
3707     char **logmsg, void *arg)
3708 {
3709 	struct got_commit_object *commit = arg;
3710 
3711 	*logmsg = strdup(got_object_commit_get_logmsg(commit));
3712 	if (*logmsg == NULL)
3713 		return got_error_from_errno("strdup");
3714 
3715 	return NULL;
3716 }
3717 
3718 static const struct got_error *
3719 rebase_status(void *arg, unsigned char status, const char *path,
3720     struct got_object_id *blob_id, struct got_object_id *commit_id)
3721 {
3722 	return NULL;
3723 }
3724 
3725 const struct got_error *
3726 got_worktree_rebase_merge_files(struct got_worktree *worktree,
3727     struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
3728     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
3729     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
3730 {
3731 	const struct got_error *err;
3732 	struct got_fileindex *fileindex;
3733 	char *fileindex_path, *commit_ref_name = NULL;
3734 	struct got_reference *commit_ref = NULL;
3735 
3736 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
3737 
3738 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3739 	if (err)
3740 		return err;
3741 
3742 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3743 	if (err)
3744 		goto done;
3745 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3746 	if (err) {
3747 		if (err->code != GOT_ERR_NOT_REF)
3748 			goto done;
3749 		err = got_ref_alloc(&commit_ref, commit_ref_name, commit_id);
3750 		if (err)
3751 			goto done;
3752 		err = got_ref_write(commit_ref, repo);
3753 		if (err)
3754 			goto done;
3755 	} else {
3756 		struct got_object_id *stored_id;
3757 		int cmp;
3758 
3759 		err = got_ref_resolve(&stored_id, repo, commit_ref);
3760 		if (err)
3761 			goto done;
3762 		cmp = got_object_id_cmp(commit_id, stored_id);
3763 		free(stored_id);
3764 		if (cmp != 0) {
3765 			err = got_error(GOT_ERR_REBASE_COMMITID);
3766 			goto done;
3767 		}
3768 	}
3769 
3770 	err = merge_files(worktree, fileindex, fileindex_path,
3771 	    parent_commit_id, commit_id, repo, progress_cb, progress_arg,
3772 	    cancel_cb, cancel_arg);
3773 done:
3774 	got_fileindex_free(fileindex);
3775 	free(fileindex_path);
3776 	if (commit_ref)
3777 		got_ref_close(commit_ref);
3778 	return err;
3779 }
3780 
3781 const struct got_error *
3782 got_worktree_rebase_commit(struct got_object_id **new_commit_id,
3783     struct got_worktree *worktree, struct got_reference *tmp_branch,
3784     struct got_commit_object *orig_commit,
3785     struct got_object_id *orig_commit_id, struct got_repository *repo)
3786 {
3787 	const struct got_error *err, *sync_err;
3788 	struct got_pathlist_head commitable_paths;
3789 	struct collect_commitables_arg cc_arg;
3790 	struct got_fileindex *fileindex = NULL;
3791 	char *fileindex_path = NULL, *commit_ref_name = NULL;
3792 	struct got_reference *head_ref = NULL;
3793 	struct got_object_id *head_commit_id = NULL;
3794 	struct got_reference *commit_ref = NULL;
3795 	struct got_object_id *commit_id = NULL;
3796 
3797 	TAILQ_INIT(&commitable_paths);
3798 	*new_commit_id = NULL;
3799 
3800 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
3801 
3802 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3803 	if (err)
3804 		return err;
3805 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3806 	if (err)
3807 		goto done;
3808 	err = got_ref_resolve(&commit_id, repo, commit_ref);
3809 	if (err)
3810 		goto done;
3811 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
3812 		err = got_error(GOT_ERR_REBASE_COMMITID);
3813 		goto done;
3814 	}
3815 
3816 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3817 	if (err)
3818 		goto done;
3819 
3820 	cc_arg.commitable_paths = &commitable_paths;
3821 	cc_arg.worktree = worktree;
3822 	cc_arg.repo = repo;
3823 	err = worktree_status(worktree, "", fileindex, repo,
3824 	    collect_commitables, &cc_arg, NULL, NULL);
3825 	if (err)
3826 		goto done;
3827 
3828 	if (TAILQ_EMPTY(&commitable_paths)) {
3829 		/* No-op change; commit will be elided. */
3830 		err = got_ref_delete(commit_ref, repo);
3831 		if (err)
3832 			goto done;
3833 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3834 		goto done;
3835 	}
3836 
3837 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3838 	if (err)
3839 		goto done;
3840 
3841 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3842 	if (err)
3843 		goto done;
3844 
3845 	err = commit_worktree(new_commit_id, &commitable_paths, head_commit_id,
3846 	    worktree, NULL, got_object_commit_get_author(orig_commit),
3847 	    got_object_commit_get_committer(orig_commit),
3848 	    collect_rebase_commit_msg, orig_commit,
3849 	    rebase_status, NULL, repo);
3850 	if (err)
3851 		goto done;
3852 
3853 	err = got_ref_change_ref(tmp_branch, *new_commit_id);
3854 	if (err)
3855 		goto done;
3856 
3857 	err = got_ref_delete(commit_ref, repo);
3858 	if (err)
3859 		goto done;
3860 
3861 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
3862 	    fileindex);
3863 	sync_err = sync_fileindex(fileindex, fileindex_path);
3864 	if (sync_err && err == NULL)
3865 		err = sync_err;
3866 done:
3867 	if (fileindex)
3868 		got_fileindex_free(fileindex);
3869 	free(fileindex_path);
3870 	free(commit_ref_name);
3871 	if (commit_ref)
3872 		got_ref_close(commit_ref);
3873 	free(head_commit_id);
3874 	if (head_ref)
3875 		got_ref_close(head_ref);
3876 	if (err) {
3877 		free(*new_commit_id);
3878 		*new_commit_id = NULL;
3879 	}
3880 	return err;
3881 }
3882 
3883 const struct got_error *
3884 got_worktree_rebase_postpone(struct got_worktree *worktree)
3885 {
3886 	return lock_worktree(worktree, LOCK_SH);
3887 }
3888 
3889 static const struct got_error *
3890 delete_ref(const char *name, struct got_repository *repo)
3891 {
3892 	const struct got_error *err;
3893 	struct got_reference *ref;
3894 
3895 	err = got_ref_open(&ref, repo, name, 0);
3896 	if (err) {
3897 		if (err->code == GOT_ERR_NOT_REF)
3898 			return NULL;
3899 		return err;
3900 	}
3901 
3902 	err = got_ref_delete(ref, repo);
3903 	got_ref_close(ref);
3904 	return err;
3905 }
3906 
3907 static const struct got_error *
3908 delete_rebase_refs(struct got_worktree *worktree, struct got_repository *repo)
3909 {
3910 	const struct got_error *err;
3911 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
3912 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
3913 
3914 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3915 	if (err)
3916 		goto done;
3917 	err = delete_ref(tmp_branch_name, repo);
3918 	if (err)
3919 		goto done;
3920 
3921 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3922 	if (err)
3923 		goto done;
3924 	err = delete_ref(new_base_branch_ref_name, repo);
3925 	if (err)
3926 		goto done;
3927 
3928 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3929 	if (err)
3930 		goto done;
3931 	err = delete_ref(branch_ref_name, repo);
3932 	if (err)
3933 		goto done;
3934 
3935 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3936 	if (err)
3937 		goto done;
3938 	err = delete_ref(commit_ref_name, repo);
3939 	if (err)
3940 		goto done;
3941 
3942 done:
3943 	free(tmp_branch_name);
3944 	free(new_base_branch_ref_name);
3945 	free(branch_ref_name);
3946 	free(commit_ref_name);
3947 	return err;
3948 }
3949 
3950 const struct got_error *
3951 got_worktree_rebase_complete(struct got_worktree *worktree,
3952     struct got_reference *new_base_branch, struct got_reference *tmp_branch,
3953     struct got_reference *rebased_branch,
3954     struct got_repository *repo)
3955 {
3956 	const struct got_error *err, *unlockerr;
3957 	struct got_object_id *new_head_commit_id = NULL;
3958 
3959 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
3960 	if (err)
3961 		return err;
3962 
3963 	err = got_ref_change_ref(rebased_branch, new_head_commit_id);
3964 	if (err)
3965 		goto done;
3966 
3967 	err = got_ref_write(rebased_branch, repo);
3968 	if (err)
3969 		goto done;
3970 
3971 	err = got_worktree_set_head_ref(worktree, rebased_branch);
3972 	if (err)
3973 		goto done;
3974 
3975 	err = delete_rebase_refs(worktree, repo);
3976 done:
3977 	free(new_head_commit_id);
3978 	unlockerr = lock_worktree(worktree, LOCK_SH);
3979 	if (unlockerr && err == NULL)
3980 		err = unlockerr;
3981 	return err;
3982 }
3983 
3984 struct collect_revertible_paths_arg {
3985 	struct got_pathlist_head *revertible_paths;
3986 	struct got_worktree *worktree;
3987 };
3988 
3989 static const struct got_error *
3990 collect_revertible_paths(void *arg, unsigned char status, const char *relpath,
3991     struct got_object_id *blob_id, struct got_object_id *commit_id)
3992 {
3993 	struct collect_revertible_paths_arg *a = arg;
3994 	const struct got_error *err = NULL;
3995 	struct got_pathlist_entry *new = NULL;
3996 	char *path = NULL;
3997 
3998 	if (status != GOT_STATUS_ADD &&
3999 	    status != GOT_STATUS_DELETE &&
4000 	    status != GOT_STATUS_MODIFY &&
4001 	    status != GOT_STATUS_CONFLICT &&
4002 	    status != GOT_STATUS_MISSING)
4003 		return NULL;
4004 
4005 	if (asprintf(&path, "%s/%s", a->worktree->root_path, relpath) == -1)
4006 		return got_error_from_errno("asprintf");
4007 
4008 	err = got_pathlist_insert(&new, a->revertible_paths, path, NULL);
4009 	if (err || new == NULL)
4010 		free(path);
4011 	return err;
4012 }
4013 
4014 const struct got_error *
4015 got_worktree_rebase_abort(struct got_worktree *worktree,
4016     struct got_repository *repo, struct got_reference *new_base_branch,
4017      got_worktree_checkout_cb progress_cb, void *progress_arg)
4018 {
4019 	const struct got_error *err, *unlockerr, *sync_err;
4020 	struct got_reference *resolved = NULL;
4021 	struct got_object_id *commit_id = NULL;
4022 	struct got_fileindex *fileindex = NULL;
4023 	char *fileindex_path = NULL;
4024 	struct got_pathlist_head revertible_paths;
4025 	struct got_pathlist_entry *pe;
4026 	struct collect_revertible_paths_arg crp_arg;
4027 	struct got_object_id *tree_id = NULL;
4028 
4029 	TAILQ_INIT(&revertible_paths);
4030 
4031 	err = lock_worktree(worktree, LOCK_EX);
4032 	if (err)
4033 		return err;
4034 
4035 	err = got_ref_open(&resolved, repo,
4036 	    got_ref_get_symref_target(new_base_branch), 0);
4037 	if (err)
4038 		goto done;
4039 
4040 	err = got_worktree_set_head_ref(worktree, resolved);
4041 	if (err)
4042 		goto done;
4043 
4044 	/*
4045 	 * XXX commits to the base branch could have happened while
4046 	 * we were busy rebasing; should we store the original commit ID
4047 	 * when rebase begins and read it back here?
4048 	 */
4049 	err = got_ref_resolve(&commit_id, repo, resolved);
4050 	if (err)
4051 		goto done;
4052 
4053 	err = got_worktree_set_base_commit_id(worktree, repo, commit_id);
4054 	if (err)
4055 		goto done;
4056 
4057 	err = got_object_id_by_path(&tree_id, repo,
4058 	    worktree->base_commit_id, worktree->path_prefix);
4059 	if (err)
4060 		goto done;
4061 
4062 	err = delete_rebase_refs(worktree, repo);
4063 	if (err)
4064 		goto done;
4065 
4066 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
4067 	if (err)
4068 		goto done;
4069 
4070 	crp_arg.revertible_paths = &revertible_paths;
4071 	crp_arg.worktree = worktree;
4072 	err = worktree_status(worktree, "", fileindex, repo,
4073 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4074 	if (err)
4075 		goto done;
4076 
4077 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4078 		err = revert_file(worktree, fileindex, pe->path,
4079 		    progress_cb, progress_arg, repo);
4080 		if (err)
4081 			goto sync;
4082 	}
4083 
4084 	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
4085 	    repo, progress_cb, progress_arg, NULL, NULL);
4086 sync:
4087 	sync_err = sync_fileindex(fileindex, fileindex_path);
4088 	if (sync_err && err == NULL)
4089 		err = sync_err;
4090 done:
4091 	got_ref_close(resolved);
4092 	free(tree_id);
4093 	free(commit_id);
4094 	if (fileindex)
4095 		got_fileindex_free(fileindex);
4096 	free(fileindex_path);
4097 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4098 		free((char *)pe->path);
4099 	got_pathlist_free(&revertible_paths);
4100 
4101 	unlockerr = lock_worktree(worktree, LOCK_SH);
4102 	if (unlockerr && err == NULL)
4103 		err = unlockerr;
4104 	return err;
4105 }