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 	struct bump_base_commit_id_arg bbc_arg;
1701 	int entry_type;
1702 
1703 	err = lock_worktree(worktree, LOCK_EX);
1704 	if (err)
1705 		return err;
1706 
1707 	err = find_tree_entry_for_checkout(&entry_type, &relpath, &tree_id,
1708 	    path, worktree, repo);
1709 	if (err)
1710 		goto done;
1711 
1712 	if (entry_type == GOT_OBJ_TYPE_BLOB) {
1713 		entry_name = basename(path);
1714 		if (entry_name == NULL) {
1715 			err = got_error_from_errno2("basename", path);
1716 			goto done;
1717 		}
1718 	}
1719 
1720 	/*
1721 	 * Read the file index.
1722 	 * Checking out files is supposed to be an idempotent operation.
1723 	 * If the on-disk file index is incomplete we will try to complete it.
1724 	 */
1725 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1726 	if (err)
1727 		goto done;
1728 
1729 	err = checkout_files(worktree, fileindex, relpath, tree_id, entry_name,
1730 	    repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
1731 	if (err)
1732 		goto sync;
1733 
1734 	bbc_arg.base_commit_id = worktree->base_commit_id;
1735 	bbc_arg.entry_name = entry_name;
1736 	bbc_arg.path = path;
1737 	bbc_arg.path_len = strlen(path);
1738 	bbc_arg.progress_cb = progress_cb;
1739 	bbc_arg.progress_arg = progress_arg;
1740 	err = got_fileindex_for_each_entry_safe(fileindex,
1741 	    bump_base_commit_id, &bbc_arg);
1742 sync:
1743 	sync_err = sync_fileindex(fileindex, fileindex_path);
1744 	if (sync_err && err == NULL)
1745 		err = sync_err;
1746 done:
1747 	free(fileindex_path);
1748 	free(relpath);
1749 	if (tree)
1750 		got_object_tree_close(tree);
1751 	if (commit)
1752 		got_object_commit_close(commit);
1753 	if (fileindex)
1754 		got_fileindex_free(fileindex);
1755 	unlockerr = lock_worktree(worktree, LOCK_SH);
1756 	if (unlockerr && err == NULL)
1757 		err = unlockerr;
1758 	return err;
1759 }
1760 
1761 struct merge_file_cb_arg {
1762     struct got_worktree *worktree;
1763     struct got_fileindex *fileindex;
1764     got_worktree_checkout_cb progress_cb;
1765     void *progress_arg;
1766     got_worktree_cancel_cb cancel_cb;
1767     void *cancel_arg;
1768     struct got_object_id *commit_id2;
1769 };
1770 
1771 static const struct got_error *
1772 merge_file_cb(void *arg, struct got_blob_object *blob1,
1773     struct got_blob_object *blob2, struct got_object_id *id1,
1774     struct got_object_id *id2, const char *path1, const char *path2,
1775     struct got_repository *repo)
1776 {
1777 	static const struct got_error *err = NULL;
1778 	struct merge_file_cb_arg *a = arg;
1779 	struct got_fileindex_entry *ie;
1780 	char *ondisk_path = NULL;
1781 	struct stat sb;
1782 	unsigned char status;
1783 	int local_changes_subsumed;
1784 
1785 	if (blob1 && blob2) {
1786 		ie = got_fileindex_entry_get(a->fileindex, path2);
1787 		if (ie == NULL) {
1788 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MISSING,
1789 			    path2);
1790 			return NULL;
1791 		}
1792 
1793 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1794 		    path2) == -1)
1795 			return got_error_from_errno("asprintf");
1796 
1797 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1798 		if (err)
1799 			goto done;
1800 
1801 		if (status == GOT_STATUS_DELETE) {
1802 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MERGE,
1803 			    path2);
1804 			goto done;
1805 		}
1806 		if (status != GOT_STATUS_NO_CHANGE &&
1807 		    status != GOT_STATUS_MODIFY &&
1808 		    status != GOT_STATUS_CONFLICT &&
1809 		    status != GOT_STATUS_ADD) {
1810 			(*a->progress_cb)(a->progress_arg, status, path2);
1811 			goto done;
1812 		}
1813 
1814 		err = merge_blob(&local_changes_subsumed, a->worktree, blob1,
1815 		    ondisk_path, path2, sb.st_mode, blob2, a->commit_id2, repo,
1816 		    a->progress_cb, a->progress_arg);
1817 	} else if (blob1) {
1818 		ie = got_fileindex_entry_get(a->fileindex, path1);
1819 		if (ie == NULL) {
1820 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MISSING,
1821 			    path2);
1822 			return NULL;
1823 		}
1824 
1825 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1826 		    path1) == -1)
1827 			return got_error_from_errno("asprintf");
1828 
1829 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1830 		if (err)
1831 			goto done;
1832 
1833 		switch (status) {
1834 		case GOT_STATUS_NO_CHANGE:
1835 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE,
1836 			    path1);
1837 			err = remove_ondisk_file(a->worktree->root_path, path1);
1838 			if (err)
1839 				goto done;
1840 			if (ie)
1841 				got_fileindex_entry_mark_deleted_from_disk(ie);
1842 			break;
1843 		case GOT_STATUS_DELETE:
1844 		case GOT_STATUS_MISSING:
1845 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE,
1846 			    path1);
1847 			if (ie)
1848 				got_fileindex_entry_mark_deleted_from_disk(ie);
1849 			break;
1850 		case GOT_STATUS_ADD:
1851 		case GOT_STATUS_MODIFY:
1852 		case GOT_STATUS_CONFLICT:
1853 			(*a->progress_cb)(a->progress_arg,
1854 			    GOT_STATUS_CANNOT_DELETE, path1);
1855 			break;
1856 		case GOT_STATUS_OBSTRUCTED:
1857 			(*a->progress_cb)(a->progress_arg, status, path1);
1858 			break;
1859 		default:
1860 			break;
1861 		}
1862 	} else if (blob2) {
1863 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1864 		    path2) == -1)
1865 			return got_error_from_errno("asprintf");
1866 		ie = got_fileindex_entry_get(a->fileindex, path2);
1867 		if (ie) {
1868 			err = get_file_status(&status, &sb, ie, ondisk_path,
1869 			    repo);
1870 			if (err)
1871 				goto done;
1872 			if (status != GOT_STATUS_NO_CHANGE &&
1873 			    status != GOT_STATUS_MODIFY &&
1874 			    status != GOT_STATUS_CONFLICT &&
1875 			    status != GOT_STATUS_ADD) {
1876 				(*a->progress_cb)(a->progress_arg, status,
1877 				    path2);
1878 				goto done;
1879 			}
1880 			err = merge_blob(&local_changes_subsumed, a->worktree,
1881 			    NULL, ondisk_path, path2, sb.st_mode, blob2,
1882 			    a->commit_id2, repo,
1883 			    a->progress_cb, a->progress_arg);
1884 			if (status == GOT_STATUS_DELETE) {
1885 				err = update_blob_fileindex_entry(a->worktree,
1886 				    a->fileindex, ie, ondisk_path, ie->path,
1887 				    blob2, 0);
1888 				if (err)
1889 					goto done;
1890 			}
1891 		} else {
1892 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1893 			err = install_blob(a->worktree, ondisk_path, path2,
1894 			    /* XXX get this from parent tree! */
1895 			    GOT_DEFAULT_FILE_MODE,
1896 			    sb.st_mode, blob2, 0, 0, repo,
1897 			    a->progress_cb, a->progress_arg);
1898 			if (err)
1899 				goto done;
1900 			err = got_fileindex_entry_alloc(&ie,
1901 			    ondisk_path, path2, NULL, NULL);
1902 			if (err)
1903 				goto done;
1904 			err = got_fileindex_entry_add(a->fileindex, ie);
1905 			if (err) {
1906 				got_fileindex_entry_free(ie);
1907 				goto done;
1908 			}
1909 		}
1910 	}
1911 done:
1912 	free(ondisk_path);
1913 	return err;
1914 }
1915 
1916 struct check_merge_ok_arg {
1917 	struct got_worktree *worktree;
1918 	struct got_repository *repo;
1919 };
1920 
1921 static const struct got_error *
1922 check_merge_ok(void *arg, struct got_fileindex_entry *ie)
1923 {
1924 	const struct got_error *err = NULL;
1925 	struct check_merge_ok_arg *a = arg;
1926 	unsigned char status;
1927 	struct stat sb;
1928 	char *ondisk_path;
1929 
1930 	/* Reject merges into a work tree with mixed base commits. */
1931 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
1932 	    SHA1_DIGEST_LENGTH))
1933 		return got_error(GOT_ERR_MIXED_COMMITS);
1934 
1935 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
1936 	    == -1)
1937 		return got_error_from_errno("asprintf");
1938 
1939 	/* Reject merges into a work tree with conflicted files. */
1940 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
1941 	if (err)
1942 		return err;
1943 	if (status == GOT_STATUS_CONFLICT)
1944 		return got_error(GOT_ERR_CONFLICTS);
1945 
1946 	return NULL;
1947 }
1948 
1949 static const struct got_error *
1950 merge_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
1951     const char *fileindex_path, struct got_object_id *commit_id1,
1952     struct got_object_id *commit_id2, struct got_repository *repo,
1953     got_worktree_checkout_cb progress_cb, void *progress_arg,
1954     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1955 {
1956 	const struct got_error *err = NULL, *sync_err;
1957 	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
1958 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1959 	struct merge_file_cb_arg arg;
1960 
1961 	if (commit_id1) {
1962 		err = got_object_id_by_path(&tree_id1, repo, commit_id1,
1963 		    worktree->path_prefix);
1964 		if (err)
1965 			goto done;
1966 
1967 		err = got_object_open_as_tree(&tree1, repo, tree_id1);
1968 		if (err)
1969 			goto done;
1970 	}
1971 
1972 	err = got_object_id_by_path(&tree_id2, repo, commit_id2,
1973 	    worktree->path_prefix);
1974 	if (err)
1975 		goto done;
1976 
1977 	err = got_object_open_as_tree(&tree2, repo, tree_id2);
1978 	if (err)
1979 		goto done;
1980 
1981 	arg.worktree = worktree;
1982 	arg.fileindex = fileindex;
1983 	arg.progress_cb = progress_cb;
1984 	arg.progress_arg = progress_arg;
1985 	arg.cancel_cb = cancel_cb;
1986 	arg.cancel_arg = cancel_arg;
1987 	arg.commit_id2 = commit_id2;
1988 	err = got_diff_tree(tree1, tree2, "", "", repo, merge_file_cb, &arg);
1989 	sync_err = sync_fileindex(fileindex, fileindex_path);
1990 	if (sync_err && err == NULL)
1991 		err = sync_err;
1992 done:
1993 	if (tree1)
1994 		got_object_tree_close(tree1);
1995 	if (tree2)
1996 		got_object_tree_close(tree2);
1997 	return err;
1998 }
1999 
2000 const struct got_error *
2001 got_worktree_merge_files(struct got_worktree *worktree,
2002     struct got_object_id *commit_id1, struct got_object_id *commit_id2,
2003     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
2004     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2005 {
2006 	const struct got_error *err, *unlockerr;
2007 	char *fileindex_path = NULL;
2008 	struct got_fileindex *fileindex = NULL;
2009 	struct check_merge_ok_arg mok_arg;
2010 
2011 	err = lock_worktree(worktree, LOCK_EX);
2012 	if (err)
2013 		return err;
2014 
2015 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2016 	if (err)
2017 		goto done;
2018 
2019 	mok_arg.worktree = worktree;
2020 	mok_arg.repo = repo;
2021 	err = got_fileindex_for_each_entry_safe(fileindex, check_merge_ok,
2022 	    &mok_arg);
2023 	if (err)
2024 		goto done;
2025 
2026 	err = merge_files(worktree, fileindex, fileindex_path, commit_id1,
2027 	    commit_id2, repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
2028 done:
2029 	if (fileindex)
2030 		got_fileindex_free(fileindex);
2031 	free(fileindex_path);
2032 	unlockerr = lock_worktree(worktree, LOCK_SH);
2033 	if (unlockerr && err == NULL)
2034 		err = unlockerr;
2035 	return err;
2036 }
2037 
2038 struct diff_dir_cb_arg {
2039     struct got_fileindex *fileindex;
2040     struct got_worktree *worktree;
2041     const char *status_path;
2042     size_t status_path_len;
2043     struct got_repository *repo;
2044     got_worktree_status_cb status_cb;
2045     void *status_arg;
2046     got_worktree_cancel_cb cancel_cb;
2047     void *cancel_arg;
2048 };
2049 
2050 static const struct got_error *
2051 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
2052     got_worktree_status_cb status_cb, void *status_arg,
2053     struct got_repository *repo)
2054 {
2055 	const struct got_error *err = NULL;
2056 	unsigned char status = GOT_STATUS_NO_CHANGE;
2057 	struct stat sb;
2058 	struct got_object_id blob_id, commit_id;
2059 
2060 	err = get_file_status(&status, &sb, ie, abspath, repo);
2061 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
2062 		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2063 		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2064 		err = (*status_cb)(status_arg, status, ie->path, &blob_id,
2065 		    &commit_id);
2066 	}
2067 	return err;
2068 }
2069 
2070 static const struct got_error *
2071 status_old_new(void *arg, struct got_fileindex_entry *ie,
2072     struct dirent *de, const char *parent_path)
2073 {
2074 	const struct got_error *err = NULL;
2075 	struct diff_dir_cb_arg *a = arg;
2076 	char *abspath;
2077 
2078 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2079 		return got_error(GOT_ERR_CANCELLED);
2080 
2081 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
2082 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
2083 		return NULL;
2084 
2085 	if (parent_path[0]) {
2086 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
2087 		    parent_path, de->d_name) == -1)
2088 			return got_error_from_errno("asprintf");
2089 	} else {
2090 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
2091 		    de->d_name) == -1)
2092 			return got_error_from_errno("asprintf");
2093 	}
2094 
2095 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
2096 	    a->repo);
2097 	free(abspath);
2098 	return err;
2099 }
2100 
2101 static const struct got_error *
2102 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
2103 {
2104 	struct diff_dir_cb_arg *a = arg;
2105 	struct got_object_id blob_id, commit_id;
2106 	unsigned char status;
2107 
2108 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2109 		return got_error(GOT_ERR_CANCELLED);
2110 
2111 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2112 		return NULL;
2113 
2114 	memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2115 	memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2116 	if (got_fileindex_entry_has_file_on_disk(ie))
2117 		status = GOT_STATUS_MISSING;
2118 	else
2119 		status = GOT_STATUS_DELETE;
2120 	return (*a->status_cb)(a->status_arg, status, ie->path, &blob_id,
2121 	    &commit_id);
2122 }
2123 
2124 static const struct got_error *
2125 status_new(void *arg, struct dirent *de, const char *parent_path)
2126 {
2127 	const struct got_error *err = NULL;
2128 	struct diff_dir_cb_arg *a = arg;
2129 	char *path = NULL;
2130 
2131 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2132 		return got_error(GOT_ERR_CANCELLED);
2133 
2134 	if (de->d_type == DT_DIR)
2135 		return NULL;
2136 
2137 	/* XXX ignore symlinks for now */
2138 	if (de->d_type == DT_LNK)
2139 		return NULL;
2140 
2141 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2142 		return NULL;
2143 
2144 	if (parent_path[0]) {
2145 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
2146 			return got_error_from_errno("asprintf");
2147 	} else {
2148 		path = de->d_name;
2149 	}
2150 
2151 	err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED, path,
2152 	    NULL, NULL);
2153 	if (parent_path[0])
2154 		free(path);
2155 	return err;
2156 }
2157 
2158 const struct got_error *
2159 got_worktree_status(struct got_worktree *worktree, const char *path,
2160     struct got_repository *repo, got_worktree_status_cb status_cb,
2161     void *status_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2162 {
2163 	const struct got_error *err = NULL;
2164 	DIR *workdir = NULL;
2165 	char *fileindex_path = NULL;
2166 	struct got_fileindex *fileindex = NULL;
2167 	struct got_fileindex_diff_dir_cb fdiff_cb;
2168 	struct diff_dir_cb_arg arg;
2169 	char *ondisk_path = NULL;
2170 
2171 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2172 	if (err)
2173 		return err;
2174 
2175 	if (asprintf(&ondisk_path, "%s%s%s",
2176 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
2177 		err = got_error_from_errno("asprintf");
2178 		goto done;
2179 	}
2180 	workdir = opendir(ondisk_path);
2181 	if (workdir == NULL) {
2182 		if (errno == ENOTDIR || errno == ENOENT) {
2183 			struct got_fileindex_entry *ie;
2184 			ie = got_fileindex_entry_get(fileindex, path);
2185 			if (ie == NULL) {
2186 				err = got_error(GOT_ERR_BAD_PATH);
2187 				goto done;
2188 			}
2189 			err = report_file_status(ie, ondisk_path,
2190 			    status_cb, status_arg, repo);
2191 			goto done;
2192 		} else {
2193 			err = got_error_from_errno2("opendir", ondisk_path);
2194 			goto done;
2195 		}
2196 	}
2197 	fdiff_cb.diff_old_new = status_old_new;
2198 	fdiff_cb.diff_old = status_old;
2199 	fdiff_cb.diff_new = status_new;
2200 	arg.fileindex = fileindex;
2201 	arg.worktree = worktree;
2202 	arg.status_path = path;
2203 	arg.status_path_len = strlen(path);
2204 	arg.repo = repo;
2205 	arg.status_cb = status_cb;
2206 	arg.status_arg = status_arg;
2207 	arg.cancel_cb = cancel_cb;
2208 	arg.cancel_arg = cancel_arg;
2209 	err = got_fileindex_diff_dir(fileindex, workdir, worktree->root_path,
2210 	    path, repo, &fdiff_cb, &arg);
2211 done:
2212 	if (workdir)
2213 		closedir(workdir);
2214 	free(ondisk_path);
2215 	free(fileindex_path);
2216 	got_fileindex_free(fileindex);
2217 	return err;
2218 }
2219 
2220 const struct got_error *
2221 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
2222     const char *arg)
2223 {
2224 	const struct got_error *err = NULL;
2225 	char *resolved, *path = NULL;
2226 	size_t len;
2227 
2228 	*wt_path = NULL;
2229 
2230 	resolved = realpath(arg, NULL);
2231 	if (resolved == NULL)
2232 		return got_error_from_errno2("realpath", arg);
2233 
2234 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
2235 	    strlen(got_worktree_get_root_path(worktree)))) {
2236 		err = got_error(GOT_ERR_BAD_PATH);
2237 		goto done;
2238 	}
2239 
2240 	if (strlen(resolved) > strlen(got_worktree_get_root_path(worktree))) {
2241 		err = got_path_skip_common_ancestor(&path,
2242 		    got_worktree_get_root_path(worktree), resolved);
2243 		if (err)
2244 			goto done;
2245 	} else {
2246 		path = strdup("");
2247 		if (path == NULL) {
2248 			err = got_error_from_errno("strdup");
2249 			goto done;
2250 		}
2251 	}
2252 
2253 	/* XXX status walk can't deal with trailing slash! */
2254 	len = strlen(path);
2255 	while (path[len - 1] == '/') {
2256 		path[len - 1] = '\0';
2257 		len--;
2258 	}
2259 done:
2260 	free(resolved);
2261 	if (err == NULL)
2262 		*wt_path = path;
2263 	else
2264 		free(path);
2265 	return err;
2266 }
2267 
2268 static const struct got_error *
2269 schedule_addition(const char *ondisk_path, struct got_fileindex *fileindex,
2270     const char *relpath, got_worktree_status_cb status_cb, void *status_arg,
2271     struct got_repository *repo)
2272 {
2273 	const struct got_error *err = NULL;
2274 	struct got_fileindex_entry *ie;
2275 
2276 	/* Re-adding an existing entry is a no-op. */
2277 	if (got_fileindex_entry_get(fileindex, relpath) != NULL)
2278 		return NULL;
2279 
2280 	err = got_fileindex_entry_alloc(&ie, ondisk_path, relpath, NULL, NULL);
2281 	if (err)
2282 		return err;
2283 
2284 	err = got_fileindex_entry_add(fileindex, ie);
2285 	if (err) {
2286 		got_fileindex_entry_free(ie);
2287 		return err;
2288 	}
2289 
2290 	return report_file_status(ie, relpath, status_cb, status_arg, repo);
2291 }
2292 
2293 const struct got_error *
2294 got_worktree_schedule_add(struct got_worktree *worktree,
2295     struct got_pathlist_head *ondisk_paths,
2296     got_worktree_status_cb status_cb, void *status_arg,
2297     struct got_repository *repo)
2298 {
2299 	struct got_fileindex *fileindex = NULL;
2300 	char *fileindex_path = NULL;
2301 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2302 	struct got_pathlist_entry *pe;
2303 
2304 	err = lock_worktree(worktree, LOCK_EX);
2305 	if (err)
2306 		return err;
2307 
2308 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2309 	if (err)
2310 		goto done;
2311 
2312 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2313 		char *relpath;
2314 		err = got_path_skip_common_ancestor(&relpath,
2315 		    got_worktree_get_root_path(worktree), pe->path);
2316 		if (err)
2317 			break;
2318 		err = schedule_addition(pe->path, fileindex, relpath,
2319 		    status_cb, status_arg, repo);
2320 		free(relpath);
2321 		if (err)
2322 			break;
2323 	}
2324 	sync_err = sync_fileindex(fileindex, fileindex_path);
2325 	if (sync_err && err == NULL)
2326 		err = sync_err;
2327 done:
2328 	free(fileindex_path);
2329 	if (fileindex)
2330 		got_fileindex_free(fileindex);
2331 	unlockerr = lock_worktree(worktree, LOCK_SH);
2332 	if (unlockerr && err == NULL)
2333 		err = unlockerr;
2334 	return err;
2335 }
2336 
2337 static const struct got_error *
2338 schedule_for_deletion(const char *ondisk_path, struct got_fileindex *fileindex,
2339     const char *relpath, int delete_local_mods,
2340     got_worktree_status_cb status_cb, void *status_arg,
2341     struct got_repository *repo)
2342 {
2343 	const struct got_error *err = NULL;
2344 	struct got_fileindex_entry *ie = NULL;
2345 	unsigned char status;
2346 	struct stat sb;
2347 
2348 	ie = got_fileindex_entry_get(fileindex, relpath);
2349 	if (ie == NULL)
2350 		return got_error(GOT_ERR_BAD_PATH);
2351 
2352 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2353 	if (err)
2354 		return err;
2355 
2356 	if (status != GOT_STATUS_NO_CHANGE) {
2357 		if (status == GOT_STATUS_DELETE)
2358 			return got_error_set_errno(ENOENT, ondisk_path);
2359 		if (status != GOT_STATUS_MODIFY)
2360 			return got_error(GOT_ERR_FILE_STATUS);
2361 		if (!delete_local_mods)
2362 			return got_error(GOT_ERR_FILE_MODIFIED);
2363 	}
2364 
2365 	if (unlink(ondisk_path) != 0)
2366 		return got_error_from_errno2("unlink", ondisk_path);
2367 
2368 	got_fileindex_entry_mark_deleted_from_disk(ie);
2369 	return report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2370 }
2371 
2372 const struct got_error *
2373 got_worktree_schedule_delete(struct got_worktree *worktree,
2374     struct got_pathlist_head *ondisk_paths, int delete_local_mods,
2375     got_worktree_status_cb status_cb, void *status_arg,
2376     struct got_repository *repo)
2377 {
2378 	struct got_fileindex *fileindex = NULL;
2379 	char *fileindex_path = NULL;
2380 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2381 	struct got_pathlist_entry *pe;
2382 
2383 	err = lock_worktree(worktree, LOCK_EX);
2384 	if (err)
2385 		return err;
2386 
2387 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2388 	if (err)
2389 		goto done;
2390 
2391 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2392 		char *relpath;
2393 		err = got_path_skip_common_ancestor(&relpath,
2394 		    got_worktree_get_root_path(worktree), pe->path);
2395 		if (err)
2396 			break;
2397 		err = schedule_for_deletion(pe->path, fileindex, relpath,
2398 		    delete_local_mods, status_cb, status_arg, repo);
2399 		free(relpath);
2400 		if (err)
2401 			break;
2402 	}
2403 	sync_err = sync_fileindex(fileindex, fileindex_path);
2404 	if (sync_err && err == NULL)
2405 		err = sync_err;
2406 done:
2407 	free(fileindex_path);
2408 	if (fileindex)
2409 		got_fileindex_free(fileindex);
2410 	unlockerr = lock_worktree(worktree, LOCK_SH);
2411 	if (unlockerr && err == NULL)
2412 		err = unlockerr;
2413 	return err;
2414 }
2415 
2416 static const struct got_error *
2417 revert_file(struct got_worktree *worktree, struct got_fileindex *fileindex,
2418     const char *ondisk_path,
2419     got_worktree_checkout_cb progress_cb, void *progress_arg,
2420     struct got_repository *repo)
2421 {
2422 	const struct got_error *err = NULL;
2423 	char *relpath = NULL, *parent_path = NULL;
2424 	struct got_fileindex_entry *ie;
2425 	struct got_tree_object *tree = NULL;
2426 	struct got_object_id *tree_id = NULL;
2427 	const struct got_tree_entry *te;
2428 	char *tree_path = NULL, *te_name;
2429 	struct got_blob_object *blob = NULL;
2430 	unsigned char status;
2431 	struct stat sb;
2432 
2433 	err = got_path_skip_common_ancestor(&relpath,
2434 	    got_worktree_get_root_path(worktree), ondisk_path);
2435 	if (err)
2436 		goto done;
2437 
2438 	ie = got_fileindex_entry_get(fileindex, relpath);
2439 	if (ie == NULL) {
2440 		err = got_error(GOT_ERR_BAD_PATH);
2441 		goto done;
2442 	}
2443 
2444 	/* Construct in-repository path of tree which contains this blob. */
2445 	err = got_path_dirname(&parent_path, ie->path);
2446 	if (err) {
2447 		if (err->code != GOT_ERR_BAD_PATH)
2448 			goto done;
2449 		parent_path = strdup("/");
2450 		if (parent_path == NULL) {
2451 			err = got_error_from_errno("strdup");
2452 			goto done;
2453 		}
2454 	}
2455 	if (got_path_is_root_dir(worktree->path_prefix)) {
2456 		tree_path = strdup(parent_path);
2457 		if (tree_path == NULL) {
2458 			err = got_error_from_errno("strdup");
2459 			goto done;
2460 		}
2461 	} else {
2462 		if (got_path_is_root_dir(parent_path)) {
2463 			tree_path = strdup(worktree->path_prefix);
2464 			if (tree_path == NULL) {
2465 				err = got_error_from_errno("strdup");
2466 				goto done;
2467 			}
2468 		} else {
2469 			if (asprintf(&tree_path, "%s/%s",
2470 			    worktree->path_prefix, parent_path) == -1) {
2471 				err = got_error_from_errno("asprintf");
2472 				goto done;
2473 			}
2474 		}
2475 	}
2476 
2477 	err = got_object_id_by_path(&tree_id, repo, worktree->base_commit_id,
2478 	    tree_path);
2479 	if (err)
2480 		goto done;
2481 
2482 	err = got_object_open_as_tree(&tree, repo, tree_id);
2483 	if (err)
2484 		goto done;
2485 
2486 	te_name = basename(ie->path);
2487 	if (te_name == NULL) {
2488 		err = got_error_from_errno2("basename", ie->path);
2489 		goto done;
2490 	}
2491 
2492 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2493 	if (err)
2494 		goto done;
2495 
2496 	te = got_object_tree_find_entry(tree, te_name);
2497 	if (te == NULL && status != GOT_STATUS_ADD) {
2498 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
2499 		goto done;
2500 	}
2501 
2502 	switch (status) {
2503 	case GOT_STATUS_ADD:
2504 		(*progress_cb)(progress_arg, GOT_STATUS_REVERT, ie->path);
2505 		got_fileindex_entry_remove(fileindex, ie);
2506 		break;
2507 	case GOT_STATUS_DELETE:
2508 	case GOT_STATUS_MODIFY:
2509 	case GOT_STATUS_CONFLICT:
2510 	case GOT_STATUS_MISSING: {
2511 		struct got_object_id id;
2512 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2513 		err = got_object_open_as_blob(&blob, repo, &id, 8192);
2514 		if (err)
2515 			goto done;
2516 		err = install_blob(worktree, ondisk_path, ie->path,
2517 		    te->mode, sb.st_mode, blob, 0, 1, repo, progress_cb,
2518 		    progress_arg);
2519 		if (err)
2520 			goto done;
2521 		if (status == GOT_STATUS_DELETE) {
2522 			err = update_blob_fileindex_entry(worktree,
2523 			    fileindex, ie, ondisk_path, ie->path, blob, 1);
2524 			if (err)
2525 				goto done;
2526 		}
2527 		break;
2528 	}
2529 	default:
2530 			goto done;
2531 	}
2532 done:
2533 	free(relpath);
2534 	free(parent_path);
2535 	free(tree_path);
2536 	if (blob)
2537 		got_object_blob_close(blob);
2538 	if (tree)
2539 		got_object_tree_close(tree);
2540 	free(tree_id);
2541 	return err;
2542 }
2543 
2544 const struct got_error *
2545 got_worktree_revert(struct got_worktree *worktree,
2546     struct got_pathlist_head *ondisk_paths,
2547     got_worktree_checkout_cb progress_cb, void *progress_arg,
2548     struct got_repository *repo)
2549 {
2550 	struct got_fileindex *fileindex = NULL;
2551 	char *fileindex_path = NULL;
2552 	const struct got_error *err = NULL, *unlockerr = NULL;
2553 	const struct got_error *sync_err = NULL;
2554 	struct got_pathlist_entry *pe;
2555 
2556 	err = lock_worktree(worktree, LOCK_EX);
2557 	if (err)
2558 		return err;
2559 
2560 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2561 	if (err)
2562 		goto done;
2563 
2564 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2565 		err = revert_file(worktree, fileindex, pe->path,
2566 		    progress_cb, progress_arg, repo);
2567 		if (err)
2568 			break;
2569 	}
2570 	sync_err = sync_fileindex(fileindex, fileindex_path);
2571 	if (sync_err && err == NULL)
2572 		err = sync_err;
2573 done:
2574 	free(fileindex_path);
2575 	if (fileindex)
2576 		got_fileindex_free(fileindex);
2577 	unlockerr = lock_worktree(worktree, LOCK_SH);
2578 	if (unlockerr && err == NULL)
2579 		err = unlockerr;
2580 	return err;
2581 }
2582 
2583 static void
2584 free_commitable(struct got_commitable *ct)
2585 {
2586 	free(ct->path);
2587 	free(ct->in_repo_path);
2588 	free(ct->ondisk_path);
2589 	free(ct->blob_id);
2590 	free(ct->base_blob_id);
2591 	free(ct->base_commit_id);
2592 	free(ct);
2593 }
2594 
2595 struct collect_commitables_arg {
2596 	struct got_pathlist_head *commitable_paths;
2597 	struct got_repository *repo;
2598 	struct got_worktree *worktree;
2599 };
2600 
2601 static const struct got_error *
2602 collect_commitables(void *arg, unsigned char status, const char *relpath,
2603     struct got_object_id *blob_id, struct got_object_id *commit_id)
2604 {
2605 	struct collect_commitables_arg *a = arg;
2606 	const struct got_error *err = NULL;
2607 	struct got_commitable *ct = NULL;
2608 	struct got_pathlist_entry *new = NULL;
2609 	char *parent_path = NULL, *path = NULL;
2610 	struct stat sb;
2611 
2612 	if (status == GOT_STATUS_CONFLICT)
2613 		return got_error(GOT_ERR_COMMIT_CONFLICT);
2614 
2615 	if (status != GOT_STATUS_MODIFY && status != GOT_STATUS_ADD &&
2616 	    status != GOT_STATUS_DELETE)
2617 		return NULL;
2618 
2619 	if (asprintf(&path, "/%s", relpath) == -1) {
2620 		err = got_error_from_errno("asprintf");
2621 		goto done;
2622 	}
2623 	if (strcmp(path, "/") == 0) {
2624 		parent_path = strdup("");
2625 		if (parent_path == NULL)
2626 			return got_error_from_errno("strdup");
2627 	} else {
2628 		err = got_path_dirname(&parent_path, path);
2629 		if (err)
2630 			return err;
2631 	}
2632 
2633 	ct = calloc(1, sizeof(*ct));
2634 	if (ct == NULL) {
2635 		err = got_error_from_errno("calloc");
2636 		goto done;
2637 	}
2638 
2639 	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
2640 	    relpath) == -1) {
2641 		err = got_error_from_errno("asprintf");
2642 		goto done;
2643 	}
2644 	if (status == GOT_STATUS_DELETE) {
2645 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
2646 	} else {
2647 		if (lstat(ct->ondisk_path, &sb) != 0) {
2648 			err = got_error_from_errno2("lstat", ct->ondisk_path);
2649 			goto done;
2650 		}
2651 		ct->mode = sb.st_mode;
2652 	}
2653 
2654 	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
2655 	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
2656 	    relpath) == -1) {
2657 		err = got_error_from_errno("asprintf");
2658 		goto done;
2659 	}
2660 
2661 	ct->status = status;
2662 	ct->blob_id = NULL; /* will be filled in when blob gets created */
2663 	if (ct->status != GOT_STATUS_ADD) {
2664 		ct->base_blob_id = got_object_id_dup(blob_id);
2665 		if (ct->base_blob_id == NULL) {
2666 			err = got_error_from_errno("got_object_id_dup");
2667 			goto done;
2668 		}
2669 		ct->base_commit_id = got_object_id_dup(commit_id);
2670 		if (ct->base_commit_id == NULL) {
2671 			err = got_error_from_errno("got_object_id_dup");
2672 			goto done;
2673 		}
2674 	}
2675 	ct->path = strdup(path);
2676 	if (ct->path == NULL) {
2677 		err = got_error_from_errno("strdup");
2678 		goto done;
2679 	}
2680 	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
2681 done:
2682 	if (ct && (err || new == NULL))
2683 		free_commitable(ct);
2684 	free(parent_path);
2685 	free(path);
2686 	return err;
2687 }
2688 
2689 static const struct got_error *write_tree(struct got_object_id **,
2690     struct got_tree_object *, const char *, struct got_pathlist_head *,
2691     got_worktree_status_cb status_cb, void *status_arg,
2692     struct got_repository *);
2693 
2694 static const struct got_error *
2695 write_subtree(struct got_object_id **new_subtree_id,
2696     struct got_tree_entry *te, const char *parent_path,
2697     struct got_pathlist_head *commitable_paths,
2698     got_worktree_status_cb status_cb, void *status_arg,
2699     struct got_repository *repo)
2700 {
2701 	const struct got_error *err = NULL;
2702 	struct got_tree_object *subtree;
2703 	char *subpath;
2704 
2705 	if (asprintf(&subpath, "%s%s%s", parent_path,
2706 	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
2707 		return got_error_from_errno("asprintf");
2708 
2709 	err = got_object_open_as_tree(&subtree, repo, te->id);
2710 	if (err)
2711 		return err;
2712 
2713 	err = write_tree(new_subtree_id, subtree, subpath, commitable_paths,
2714 	    status_cb, status_arg, repo);
2715 	got_object_tree_close(subtree);
2716 	free(subpath);
2717 	return err;
2718 }
2719 
2720 static const struct got_error *
2721 match_ct_parent_path(int *match, struct got_commitable *ct, const char *path)
2722 {
2723 	const struct got_error *err = NULL;
2724 	char *ct_parent_path = NULL;
2725 
2726 	*match = 0;
2727 
2728 	if (strchr(ct->path, '/') == NULL) {
2729 		*match = got_path_is_root_dir(path);
2730 		return NULL;
2731 	}
2732 
2733 	err = got_path_dirname(&ct_parent_path, ct->path);
2734 	if (err)
2735 		return err;
2736 	*match = (strcmp(path, ct_parent_path) == 0);
2737 	free(ct_parent_path);
2738 	return err;
2739 }
2740 
2741 static mode_t
2742 get_ct_file_mode(struct got_commitable *ct)
2743 {
2744 	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
2745 }
2746 
2747 static const struct got_error *
2748 alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
2749     struct got_tree_entry *te, struct got_commitable *ct)
2750 {
2751 	const struct got_error *err = NULL;
2752 
2753 	*new_te = NULL;
2754 
2755 	err = got_object_tree_entry_dup(new_te, te);
2756 	if (err)
2757 		goto done;
2758 
2759 	(*new_te)->mode = get_ct_file_mode(ct);
2760 
2761 	free((*new_te)->id);
2762 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2763 	if ((*new_te)->id == NULL) {
2764 		err = got_error_from_errno("got_object_id_dup");
2765 		goto done;
2766 	}
2767 done:
2768 	if (err && *new_te) {
2769 		got_object_tree_entry_close(*new_te);
2770 		*new_te = NULL;
2771 	}
2772 	return err;
2773 }
2774 
2775 static const struct got_error *
2776 alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
2777     struct got_commitable *ct)
2778 {
2779 	const struct got_error *err = NULL;
2780 	char *ct_name;
2781 
2782 	 *new_te = NULL;
2783 
2784 	*new_te = calloc(1, sizeof(**new_te));
2785 	if (*new_te == NULL)
2786 		return got_error_from_errno("calloc");
2787 
2788 	ct_name = basename(ct->path);
2789 	if (ct_name == NULL) {
2790 		err = got_error_from_errno2("basename", ct->path);
2791 		goto done;
2792 	}
2793 	(*new_te)->name = strdup(ct_name);
2794 	if ((*new_te)->name == NULL) {
2795 		err = got_error_from_errno("strdup");
2796 		goto done;
2797 	}
2798 
2799 	(*new_te)->mode = get_ct_file_mode(ct);
2800 
2801 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2802 	if ((*new_te)->id == NULL) {
2803 		err = got_error_from_errno("got_object_id_dup");
2804 		goto done;
2805 	}
2806 done:
2807 	if (err && *new_te) {
2808 		got_object_tree_entry_close(*new_te);
2809 		*new_te = NULL;
2810 	}
2811 	return err;
2812 }
2813 
2814 static const struct got_error *
2815 insert_tree_entry(struct got_tree_entry *new_te,
2816     struct got_pathlist_head *paths)
2817 {
2818 	const struct got_error *err = NULL;
2819 	struct got_pathlist_entry *new_pe;
2820 
2821 	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
2822 	if (err)
2823 		return err;
2824 	if (new_pe == NULL)
2825 		return got_error(GOT_ERR_TREE_DUP_ENTRY);
2826 	return NULL;
2827 }
2828 
2829 static const struct got_error *
2830 report_ct_status(struct got_commitable *ct,
2831     got_worktree_status_cb status_cb, void *status_arg)
2832 {
2833 	const char *ct_path = ct->path;
2834 	while (ct_path[0] == '/')
2835 		ct_path++;
2836 	return (*status_cb)(status_arg, ct->status, ct_path, ct->blob_id, NULL);
2837 }
2838 
2839 static const struct got_error *
2840 match_modified_subtree(int *modified, struct got_tree_entry *te,
2841     const char *base_tree_path, struct got_pathlist_head *commitable_paths)
2842 {
2843 	const struct got_error *err = NULL;
2844 	struct got_pathlist_entry *pe;
2845 	char *te_path;
2846 
2847 	*modified = 0;
2848 
2849 	if (asprintf(&te_path, "%s%s%s", base_tree_path,
2850 	    got_path_is_root_dir(base_tree_path) ? "" : "/",
2851 	    te->name) == -1)
2852 		return got_error_from_errno("asprintf");
2853 
2854 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2855 		struct got_commitable *ct = pe->data;
2856 		*modified = got_path_is_child(ct->in_repo_path, te_path,
2857 		    strlen(te_path));
2858 		 if (*modified)
2859 			break;
2860 	}
2861 
2862 	free(te_path);
2863 	return err;
2864 }
2865 
2866 static const struct got_error *
2867 match_deleted_or_modified_ct(struct got_commitable **ctp,
2868     struct got_tree_entry *te, const char *base_tree_path,
2869     struct got_pathlist_head *commitable_paths)
2870 {
2871 	const struct got_error *err = NULL;
2872 	struct got_pathlist_entry *pe;
2873 
2874 	*ctp = NULL;
2875 
2876 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2877 		struct got_commitable *ct = pe->data;
2878 		char *ct_name = NULL;
2879 		int path_matches;
2880 
2881 		if (ct->status != GOT_STATUS_MODIFY &&
2882 		    ct->status != GOT_STATUS_DELETE)
2883 			continue;
2884 
2885 		if (got_object_id_cmp(ct->base_blob_id, te->id) != 0)
2886 			continue;
2887 
2888 		 err = match_ct_parent_path(&path_matches, ct, base_tree_path);
2889 		 if (err)
2890 			return err;
2891 		if (!path_matches)
2892 			continue;
2893 
2894 		ct_name = basename(pe->path);
2895 		if (ct_name == NULL)
2896 			return got_error_from_errno2("basename", pe->path);
2897 
2898 		if (strcmp(te->name, ct_name) != 0)
2899 			continue;
2900 
2901 		*ctp = ct;
2902 		break;
2903 	}
2904 
2905 	return err;
2906 }
2907 
2908 static const struct got_error *
2909 make_subtree_for_added_blob(struct got_tree_entry **new_tep,
2910     const char *child_path, const char *path_base_tree,
2911     struct got_pathlist_head *commitable_paths,
2912     got_worktree_status_cb status_cb, void *status_arg,
2913     struct got_repository *repo)
2914 {
2915 	const struct got_error *err = NULL;
2916 	struct got_tree_entry *new_te;
2917 	char *subtree_path;
2918 
2919 	*new_tep = NULL;
2920 
2921 	if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
2922 	    got_path_is_root_dir(path_base_tree) ? "" : "/",
2923 	    child_path) == -1)
2924 		return got_error_from_errno("asprintf");
2925 
2926 	new_te = calloc(1, sizeof(*new_te));
2927 	new_te->mode = S_IFDIR;
2928 	new_te->name = strdup(child_path);
2929 	if (new_te->name == NULL) {
2930 		err = got_error_from_errno("strdup");
2931 		got_object_tree_entry_close(new_te);
2932 		goto done;
2933 	}
2934 	err = write_tree(&new_te->id, NULL, subtree_path,
2935 	    commitable_paths, status_cb, status_arg, repo);
2936 	if (err) {
2937 		got_object_tree_entry_close(new_te);
2938 		goto done;
2939 	}
2940 done:
2941 	free(subtree_path);
2942 	if (err == NULL)
2943 		*new_tep = new_te;
2944 	return err;
2945 }
2946 
2947 static const struct got_error *
2948 write_tree(struct got_object_id **new_tree_id,
2949     struct got_tree_object *base_tree, const char *path_base_tree,
2950     struct got_pathlist_head *commitable_paths,
2951     got_worktree_status_cb status_cb, void *status_arg,
2952     struct got_repository *repo)
2953 {
2954 	const struct got_error *err = NULL;
2955 	const struct got_tree_entries *base_entries = NULL;
2956 	struct got_pathlist_head paths;
2957 	struct got_tree_entries new_tree_entries;
2958 	struct got_tree_entry *te, *new_te = NULL;
2959 	struct got_pathlist_entry *pe;
2960 
2961 	TAILQ_INIT(&paths);
2962 	new_tree_entries.nentries = 0;
2963 	SIMPLEQ_INIT(&new_tree_entries.head);
2964 
2965 	/* Insert, and recurse into, newly added entries first. */
2966 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2967 		struct got_commitable *ct = pe->data;
2968 		char *child_path = NULL, *slash;
2969 
2970 		if (ct->status != GOT_STATUS_ADD ||
2971 		    (ct->flags & GOT_COMMITABLE_ADDED))
2972 			continue;
2973 
2974 		 if (!got_path_is_child(pe->path, path_base_tree,
2975 		     strlen(path_base_tree)))
2976 			continue;
2977 
2978 		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
2979 		    pe->path);
2980 		if (err)
2981 			goto done;
2982 
2983 		slash = strchr(child_path, '/');
2984 		if (slash == NULL) {
2985 			err = alloc_added_blob_tree_entry(&new_te, ct);
2986 			if (err)
2987 				goto done;
2988 			err = report_ct_status(ct, status_cb, status_arg);
2989 			if (err)
2990 				goto done;
2991 			ct->flags |= GOT_COMMITABLE_ADDED;
2992 			err = insert_tree_entry(new_te, &paths);
2993 			if (err)
2994 				goto done;
2995 		} else {
2996 			*slash = '\0'; /* trim trailing path components */
2997 			if (base_tree == NULL ||
2998 			    got_object_tree_find_entry(base_tree, child_path)
2999 			    == NULL) {
3000 				err = make_subtree_for_added_blob(&new_te,
3001 				    child_path, path_base_tree,
3002 				    commitable_paths, status_cb, status_arg,
3003 				    repo);
3004 				if (err)
3005 					goto done;
3006 				err = insert_tree_entry(new_te, &paths);
3007 				if (err)
3008 					goto done;
3009 			}
3010 		}
3011 	}
3012 
3013 	if (base_tree) {
3014 		/* Handle modified and deleted entries. */
3015 		base_entries = got_object_tree_get_entries(base_tree);
3016 		SIMPLEQ_FOREACH(te, &base_entries->head, entry) {
3017 			struct got_commitable *ct = NULL;
3018 
3019 			if (S_ISDIR(te->mode)) {
3020 				int modified;
3021 				err = got_object_tree_entry_dup(&new_te, te);
3022 				if (err)
3023 					goto done;
3024 				err = match_modified_subtree(&modified, te,
3025 				    path_base_tree, commitable_paths);
3026 				if (err)
3027 					goto done;
3028 				/* Avoid recursion into unmodified subtrees. */
3029 				if (modified) {
3030 					free(new_te->id);
3031 					err = write_subtree(&new_te->id, te,
3032 					    path_base_tree, commitable_paths,
3033 					    status_cb, status_arg, repo);
3034 					if (err)
3035 						goto done;
3036 				}
3037 				err = insert_tree_entry(new_te, &paths);
3038 				if (err)
3039 					goto done;
3040 				continue;
3041 			}
3042 
3043 			err = match_deleted_or_modified_ct(&ct, te,
3044 			    path_base_tree, commitable_paths);
3045 			if (ct) {
3046 				/* NB: Deleted entries get dropped here. */
3047 				if (ct->status == GOT_STATUS_MODIFY) {
3048 					err = alloc_modified_blob_tree_entry(
3049 					    &new_te, te, ct);
3050 					if (err)
3051 						goto done;
3052 					err = insert_tree_entry(new_te, &paths);
3053 					if (err)
3054 						goto done;
3055 				}
3056 				err = report_ct_status(ct, status_cb,
3057 				    status_arg);
3058 				if (err)
3059 					goto done;
3060 			} else {
3061 				/* Entry is unchanged; just copy it. */
3062 				err = got_object_tree_entry_dup(&new_te, te);
3063 				if (err)
3064 					goto done;
3065 				err = insert_tree_entry(new_te, &paths);
3066 				if (err)
3067 					goto done;
3068 			}
3069 		}
3070 	}
3071 
3072 	/* Write new list of entries; deleted entries have been dropped. */
3073 	TAILQ_FOREACH(pe, &paths, entry) {
3074 		struct got_tree_entry *te = pe->data;
3075 		new_tree_entries.nentries++;
3076 		SIMPLEQ_INSERT_TAIL(&new_tree_entries.head, te, entry);
3077 	}
3078 	err = got_object_tree_create(new_tree_id, &new_tree_entries, repo);
3079 done:
3080 	got_object_tree_entries_close(&new_tree_entries);
3081 	got_pathlist_free(&paths);
3082 	return err;
3083 }
3084 
3085 static const struct got_error *
3086 update_fileindex_after_commit(struct got_pathlist_head *commitable_paths,
3087     struct got_object_id *new_base_commit_id, struct got_fileindex *fileindex,
3088     struct got_worktree *worktree)
3089 {
3090 	const struct got_error *err = NULL;
3091 	struct got_pathlist_entry *pe;
3092 
3093 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3094 		struct got_fileindex_entry *ie;
3095 		struct got_commitable *ct = pe->data;
3096 
3097 		ie = got_fileindex_entry_get(fileindex, pe->path);
3098 		if (ie) {
3099 			if (ct->status == GOT_STATUS_DELETE) {
3100 				got_fileindex_entry_remove(fileindex, ie);
3101 				got_fileindex_entry_free(ie);
3102 			} else
3103 				err = got_fileindex_entry_update(ie,
3104 				    ct->ondisk_path, ct->blob_id->sha1,
3105 				    new_base_commit_id->sha1, 1);
3106 		} else {
3107 			err = got_fileindex_entry_alloc(&ie,
3108 			    ct->ondisk_path, pe->path, ct->blob_id->sha1,
3109 			    new_base_commit_id->sha1);
3110 			if (err)
3111 				break;
3112 			err = got_fileindex_entry_add(fileindex, ie);
3113 			if (err)
3114 				break;
3115 		}
3116 	}
3117 	return err;
3118 }
3119 
3120 static const struct got_error *
3121 check_ct_out_of_date(struct got_commitable *ct, struct got_repository *repo,
3122 	struct got_object_id *head_commit_id)
3123 {
3124 	const struct got_error *err = NULL;
3125 	struct got_object_id *id_in_head = NULL, *id = NULL;
3126 	struct got_commit_object *commit = NULL;
3127 	char *path = NULL;
3128 	const char *ct_path = ct->in_repo_path;
3129 
3130 	while (ct_path[0] == '/')
3131 		ct_path++;
3132 
3133 	/*
3134 	 * Ensure that no modifications were made to files *and their parents*
3135 	 * in commits between the file's base commit and the branch head.
3136 	 *
3137 	 * Checking the parents is important for detecting conflicting tree
3138 	 * configurations (files or parent folders might have been moved,
3139 	 * deleted, added again, etc.). Such changes need to be merged with
3140 	 * local changes before a commit can occur.
3141 	 *
3142 	 * The implication is that the file's (parent) entry in the root
3143 	 * directory must have the same ID in all relevant commits.
3144 	 */
3145 	if (ct->status != GOT_STATUS_ADD) {
3146 		struct got_object_qid *pid;
3147 		char *slash;
3148 		struct got_object_id *root_entry_id = NULL;
3149 
3150 		/* Trivial case: base commit == head commit */
3151 		if (got_object_id_cmp(ct->base_commit_id, head_commit_id) == 0)
3152 			return NULL;
3153 
3154 		/* Compute the path to the root directory's entry. */
3155 		path = strdup(ct_path);
3156 		if (path == NULL) {
3157 			err = got_error_from_errno("strdup");
3158 			goto done;
3159 		}
3160 		slash = strchr(path, '/');
3161 		if (slash)
3162 			*slash = '\0';
3163 
3164 		err = got_object_open_as_commit(&commit, repo, head_commit_id);
3165 		if (err)
3166 			goto done;
3167 
3168 		err = got_object_id_by_path(&root_entry_id, repo,
3169 		    head_commit_id, path);
3170 		if (err)
3171 			goto done;
3172 
3173 		pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(commit));
3174 		while (pid) {
3175 			struct got_commit_object *pcommit;
3176 
3177 			err = got_object_id_by_path(&id, repo, pid->id, path);
3178 			if (err) {
3179 				if (err->code != GOT_ERR_NO_TREE_ENTRY)
3180 					goto done;
3181 				err = NULL;
3182 				break;
3183 			}
3184 
3185 			err = got_object_id_by_path(&id, repo, pid->id, path);
3186 			if (err)
3187 				goto done;
3188 
3189 			if (got_object_id_cmp(id, root_entry_id) != 0) {
3190 				err = got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3191 				break;
3192 			}
3193 
3194 			if (got_object_id_cmp(pid->id, ct->base_commit_id) == 0)
3195 				break; /* all relevant commits scanned */
3196 
3197 			err = got_object_open_as_commit(&pcommit, repo,
3198 			    pid->id);
3199 			if (err)
3200 				goto done;
3201 
3202 			got_object_commit_close(commit);
3203 			commit = pcommit;
3204 			pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(
3205 			    commit));
3206 		}
3207 	} else {
3208 		/* Require that added files don't exist in the branch head. */
3209 		err = got_object_id_by_path(&id_in_head, repo, head_commit_id,
3210 		    ct_path);
3211 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
3212 			goto done;
3213 		err = id_in_head ? got_error(GOT_ERR_COMMIT_OUT_OF_DATE) : NULL;
3214 	}
3215 done:
3216 	if (commit)
3217 		got_object_commit_close(commit);
3218 	free(id_in_head);
3219 	free(id);
3220 	free(path);
3221 	return err;
3222 }
3223 
3224 const struct got_error *
3225 got_worktree_commit(struct got_object_id **new_commit_id,
3226     struct got_worktree *worktree, const char *ondisk_path,
3227     const char *author, const char *committer,
3228     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3229     got_worktree_status_cb status_cb, void *status_arg,
3230     struct got_repository *repo)
3231 {
3232 	const struct got_error *err = NULL, *unlockerr = NULL, *sync_err;
3233 	struct got_fileindex *fileindex = NULL;
3234 	char *fileindex_path = NULL;
3235 	struct collect_commitables_arg cc_arg;
3236 	struct got_pathlist_head commitable_paths;
3237 	struct got_pathlist_entry *pe;
3238 	char *relpath = NULL;
3239 	const char *head_ref_name = NULL;
3240 	struct got_reference *head_ref = NULL;
3241 	struct got_commit_object *head_commit = NULL;
3242 	struct got_object_id *head_commit_id = NULL;
3243 	struct got_reference *head_ref2 = NULL;
3244 	struct got_object_id *head_commit_id2 = NULL;
3245 	struct got_tree_object *head_tree = NULL;
3246 	struct got_object_id *new_tree_id = NULL;
3247 	struct got_object_id_queue parent_ids;
3248 	struct got_object_qid *pid = NULL;
3249 	char *logmsg = NULL;
3250 
3251 	*new_commit_id = NULL;
3252 
3253 	TAILQ_INIT(&commitable_paths);
3254 	SIMPLEQ_INIT(&parent_ids);
3255 
3256 	if (ondisk_path) {
3257 		err = got_path_skip_common_ancestor(&relpath,
3258 		    worktree->root_path, ondisk_path);
3259 		if (err)
3260 			return err;
3261 	}
3262 
3263 	err = lock_worktree(worktree, LOCK_EX);
3264 	if (err)
3265 		goto done;
3266 
3267 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3268 	if (err)
3269 		goto done;
3270 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3271 	if (err)
3272 		goto done;
3273 
3274 	cc_arg.commitable_paths = &commitable_paths;
3275 	cc_arg.worktree = worktree;
3276 	cc_arg.repo = repo;
3277 	err = got_worktree_status(worktree, relpath ? relpath : "",
3278 	    repo, collect_commitables, &cc_arg, NULL, NULL);
3279 	if (err)
3280 		goto done;
3281 
3282 	if (TAILQ_EMPTY(&commitable_paths)) {
3283 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3284 		goto done;
3285 	}
3286 
3287 	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
3288 	if (err)
3289 		goto done;
3290 
3291 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3292 		struct got_commitable *ct = pe->data;
3293 		err = check_ct_out_of_date(ct, repo, head_commit_id);
3294 		if (err)
3295 			goto done;
3296 	}
3297 
3298 	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
3299 	if (err)
3300 		goto done;
3301 
3302 	if (commit_msg_cb != NULL) {
3303 		err = commit_msg_cb(&commitable_paths, &logmsg, commit_arg);
3304 		if (err)
3305 			goto done;
3306 	}
3307 
3308 	if (logmsg == NULL || strlen(logmsg) == 0) {
3309 		err = got_error(GOT_ERR_COMMIT_MSG_EMPTY);
3310 		goto done;
3311 	}
3312 
3313 	/* Create blobs from added and modified files and record their IDs. */
3314 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3315 		struct got_commitable *ct = pe->data;
3316 		char *ondisk_path;
3317 
3318 		if (ct->status != GOT_STATUS_ADD &&
3319 		    ct->status != GOT_STATUS_MODIFY)
3320 			continue;
3321 
3322 		if (asprintf(&ondisk_path, "%s/%s",
3323 		    worktree->root_path, pe->path) == -1) {
3324 			err = got_error_from_errno("asprintf");
3325 			goto done;
3326 		}
3327 		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
3328 		free(ondisk_path);
3329 		if (err)
3330 			goto done;
3331 	}
3332 
3333 	/* Recursively write new tree objects. */
3334 	err = write_tree(&new_tree_id, head_tree, "/", &commitable_paths,
3335 	    status_cb, status_arg, repo);
3336 	if (err)
3337 		goto done;
3338 
3339 	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
3340 	if (err)
3341 		goto done;
3342 	SIMPLEQ_INSERT_TAIL(&parent_ids, pid, entry);
3343 	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
3344 	    1, author, time(NULL), committer, time(NULL), logmsg, repo);
3345 	got_object_qid_free(pid);
3346 	if (logmsg != NULL)
3347 		free(logmsg);
3348 	if (err)
3349 		goto done;
3350 
3351 	/* Check if a concurrent commit to our branch has occurred. */
3352 	head_ref_name = got_worktree_get_head_ref_name(worktree);
3353 	if (head_ref_name == NULL) {
3354 		err = got_error_from_errno("got_worktree_get_head_ref_name");
3355 		goto done;
3356 	}
3357 	/* Lock the reference here to prevent concurrent modification. */
3358 	err = got_ref_open(&head_ref2, repo, head_ref_name, 1);
3359 	if (err)
3360 		goto done;
3361 	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
3362 	if (err)
3363 		goto done;
3364 	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
3365 		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
3366 		goto done;
3367 	}
3368 	/* Update branch head in repository. */
3369 	err = got_ref_change_ref(head_ref2, *new_commit_id);
3370 	if (err)
3371 		goto done;
3372 	err = got_ref_write(head_ref2, repo);
3373 	if (err)
3374 		goto done;
3375 
3376 	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
3377 	if (err)
3378 		goto done;
3379 
3380 	err = ref_base_commit(worktree, repo);
3381 	if (err)
3382 		goto done;
3383 
3384 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3385 	if (err)
3386 		goto done;
3387 
3388 	err = update_fileindex_after_commit(&commitable_paths,
3389 	    *new_commit_id, fileindex, worktree);
3390 	if (err)
3391 		goto done;
3392 done:
3393 	if (fileindex) {
3394 		sync_err = sync_fileindex(fileindex, fileindex_path);
3395 		if (sync_err && err == NULL)
3396 			err = sync_err;
3397 		got_fileindex_free(fileindex);
3398 	}
3399 	free(fileindex_path);
3400 	unlockerr = lock_worktree(worktree, LOCK_SH);
3401 	if (unlockerr && err == NULL)
3402 		err = unlockerr;
3403 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3404 		struct got_commitable *ct = pe->data;
3405 		free_commitable(ct);
3406 	}
3407 	got_pathlist_free(&commitable_paths);
3408 	if (head_tree)
3409 		got_object_tree_close(head_tree);
3410 	if (head_commit)
3411 		got_object_commit_close(head_commit);
3412 	free(relpath);
3413 	free(head_commit_id);
3414 	free(head_commit_id2);
3415 	if (head_ref)
3416 		got_ref_close(head_ref);
3417 	if (head_ref2) {
3418 		unlockerr = got_ref_unlock(head_ref2);
3419 		if (unlockerr && err == NULL)
3420 			err = unlockerr;
3421 		got_ref_close(head_ref2);
3422 	}
3423 	return err;
3424 }
3425 
3426 const char *
3427 got_commitable_get_path(struct got_commitable *ct)
3428 {
3429 	return ct->path;
3430 }
3431 
3432 unsigned int
3433 got_commitable_get_status(struct got_commitable *ct)
3434 {
3435 	return ct->status;
3436 }
3437 
3438 struct check_rebase_ok_arg {
3439 	struct got_worktree *worktree;
3440 	struct got_repository *repo;
3441 	int rebase_in_progress;
3442 };
3443 
3444 static const struct got_error *
3445 check_rebase_ok(void *arg, struct got_fileindex_entry *ie)
3446 {
3447 	const struct got_error *err = NULL;
3448 	struct check_rebase_ok_arg *a = arg;
3449 	unsigned char status;
3450 	struct stat sb;
3451 	char *ondisk_path;
3452 
3453 	if (!a->rebase_in_progress) {
3454 		/* Reject rebase of a work tree with mixed base commits. */
3455 		if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
3456 		    SHA1_DIGEST_LENGTH))
3457 			return got_error(GOT_ERR_MIXED_COMMITS);
3458 	}
3459 
3460 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
3461 	    == -1)
3462 		return got_error_from_errno("asprintf");
3463 
3464 	/* Reject rebase of a work tree with modified or conflicted files. */
3465 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
3466 	free(ondisk_path);
3467 	if (err)
3468 		return err;
3469 
3470 	if (a->rebase_in_progress) {
3471 		if (status == GOT_STATUS_CONFLICT)
3472 			return got_error(GOT_ERR_CONFLICTS);
3473 	} else if (status != GOT_STATUS_NO_CHANGE)
3474 		return got_error(GOT_ERR_MODIFIED);
3475 
3476 	return NULL;
3477 }
3478 
3479 const struct got_error *
3480 got_worktree_rebase_prepare(struct got_reference **new_base_branch_ref,
3481     struct got_reference **tmp_branch, struct got_worktree *worktree,
3482     struct got_reference *branch, struct got_repository *repo)
3483 {
3484 	const struct got_error *err = NULL;
3485 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
3486 	char *branch_ref_name = NULL;
3487 	struct got_fileindex *fileindex = NULL;
3488 	char *fileindex_path = NULL;
3489 	struct check_rebase_ok_arg ok_arg;
3490 	struct got_reference *wt_branch = NULL, *branch_ref = NULL;
3491 
3492 	*new_base_branch_ref = NULL;
3493 	*tmp_branch = NULL;
3494 
3495 	err = lock_worktree(worktree, LOCK_EX);
3496 	if (err)
3497 		return err;
3498 
3499 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3500 	if (err)
3501 		goto done;
3502 
3503 	ok_arg.worktree = worktree;
3504 	ok_arg.repo = repo;
3505 	ok_arg.rebase_in_progress = 0;
3506 	err = got_fileindex_for_each_entry_safe(fileindex, check_rebase_ok,
3507 	    &ok_arg);
3508 	if (err)
3509 		goto done;
3510 
3511 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3512 	if (err)
3513 		goto done;
3514 
3515 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3516 	if (err)
3517 		goto done;
3518 
3519 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3520 	if (err)
3521 		goto done;
3522 
3523 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
3524 	    0);
3525 	if (err)
3526 		goto done;
3527 
3528 	err = got_ref_alloc_symref(new_base_branch_ref,
3529 	    new_base_branch_ref_name, wt_branch);
3530 	if (err)
3531 		goto done;
3532 	err = got_ref_write(*new_base_branch_ref, repo);
3533 	if (err)
3534 		goto done;
3535 
3536 	/* TODO Lock original branch's ref while rebasing? */
3537 
3538 	err = got_ref_alloc_symref(&branch_ref, branch_ref_name, branch);
3539 	if (err)
3540 		goto done;
3541 
3542 	err = got_ref_write(branch_ref, repo);
3543 	if (err)
3544 		goto done;
3545 
3546 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
3547 	    worktree->base_commit_id);
3548 	if (err)
3549 		goto done;
3550 	err = got_ref_write(*tmp_branch, repo);
3551 	if (err)
3552 		goto done;
3553 
3554 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
3555 	if (err)
3556 		goto done;
3557 done:
3558 	free(fileindex_path);
3559 	if (fileindex)
3560 		got_fileindex_free(fileindex);
3561 	free(tmp_branch_name);
3562 	free(new_base_branch_ref_name);
3563 	free(branch_ref_name);
3564 	if (branch_ref)
3565 		got_ref_close(branch_ref);
3566 	if (wt_branch)
3567 		got_ref_close(wt_branch);
3568 	if (err) {
3569 		if (*new_base_branch_ref) {
3570 			got_ref_close(*new_base_branch_ref);
3571 			*new_base_branch_ref = NULL;
3572 		}
3573 		if (*tmp_branch) {
3574 			got_ref_close(*tmp_branch);
3575 			*tmp_branch = NULL;
3576 		}
3577 		lock_worktree(worktree, LOCK_SH);
3578 	}
3579 	return err;
3580 }
3581 
3582 const struct got_error *
3583 got_worktree_rebase_continue(struct got_object_id **commit_id,
3584     struct got_reference **new_base_branch, struct got_reference **tmp_branch,
3585     struct got_reference **branch, struct got_worktree *worktree,
3586     struct got_repository *repo)
3587 {
3588 	const struct got_error *err;
3589 	char *commit_ref_name = NULL, *new_base_branch_ref_name = NULL;
3590 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
3591 	struct got_reference *commit_ref = NULL, *branch_ref = NULL;
3592 
3593 	*commit_id = NULL;
3594 
3595 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3596 	if (err)
3597 		return err;
3598 
3599 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3600 	if (err)
3601 		goto done;
3602 
3603 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3604 	if (err)
3605 		goto done;
3606 
3607 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3608 	if (err)
3609 		goto done;
3610 
3611 	err = got_ref_open(&branch_ref, repo, branch_ref_name, 0);
3612 	if (err)
3613 		goto done;
3614 
3615 	err = got_ref_open(branch, repo,
3616 	    got_ref_get_symref_target(branch_ref), 0);
3617 	if (err)
3618 		goto done;
3619 
3620 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3621 	if (err)
3622 		goto done;
3623 
3624 	err = got_ref_resolve(commit_id, repo, commit_ref);
3625 	if (err)
3626 		goto done;
3627 
3628 	err = got_ref_open(new_base_branch, repo,
3629 	    new_base_branch_ref_name, 0);
3630 	if (err)
3631 		goto done;
3632 
3633 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
3634 	if (err)
3635 		goto done;
3636 done:
3637 	free(commit_ref_name);
3638 	free(branch_ref_name);
3639 	if (commit_ref)
3640 		got_ref_close(commit_ref);
3641 	if (branch_ref)
3642 		got_ref_close(branch_ref);
3643 	if (err) {
3644 		free(*commit_id);
3645 		*commit_id = NULL;
3646 		if (*tmp_branch) {
3647 			got_ref_close(*tmp_branch);
3648 			*tmp_branch = NULL;
3649 		}
3650 		if (*new_base_branch) {
3651 			got_ref_close(*new_base_branch);
3652 			*new_base_branch = NULL;
3653 		}
3654 		if (*branch) {
3655 			got_ref_close(*branch);
3656 			*branch = NULL;
3657 		}
3658 	}
3659 	return err;
3660 }
3661 
3662 const struct got_error *
3663 got_worktree_rebase_in_progress(int *in_progress, struct got_worktree *worktree)
3664 {
3665 	const struct got_error *err;
3666 	char *tmp_branch_name = NULL;
3667 
3668 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3669 	if (err)
3670 		return err;
3671 
3672 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
3673 	free(tmp_branch_name);
3674 	return NULL;
3675 }
3676 
3677 static const struct got_error *
3678 collect_rebase_commit_msg(struct got_pathlist_head *commitable_paths,
3679     char **logmsg, void *arg)
3680 {
3681 	struct got_commit_object *commit = arg;
3682 
3683 	*logmsg = strdup(got_object_commit_get_logmsg(commit));
3684 	if (*logmsg == NULL)
3685 		return got_error_from_errno("strdup");
3686 
3687 	return NULL;
3688 }
3689 
3690 static const struct got_error *
3691 rebase_status(void *arg, unsigned char status, const char *path,
3692     struct got_object_id *blob_id, struct got_object_id *commit_id)
3693 {
3694 	return NULL;
3695 }
3696 
3697 const struct got_error *
3698 got_worktree_rebase_merge_files(struct got_worktree *worktree,
3699     struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
3700     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
3701     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
3702 {
3703 	const struct got_error *err;
3704 	struct got_fileindex *fileindex;
3705 	char *fileindex_path, *commit_ref_name = NULL;
3706 	struct got_reference *commit_ref = NULL;
3707 
3708 	/* Work tree is locked/unlocked during rebase prepartion/teardown. */
3709 
3710 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3711 	if (err)
3712 		return err;
3713 
3714 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3715 	if (err)
3716 		goto done;
3717 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3718 	if (err) {
3719 		if (err->code != GOT_ERR_NOT_REF)
3720 			goto done;
3721 		err = got_ref_alloc(&commit_ref, commit_ref_name, commit_id);
3722 		if (err)
3723 			goto done;
3724 		err = got_ref_write(commit_ref, repo);
3725 		if (err)
3726 			goto done;
3727 	} else {
3728 		struct got_object_id *stored_id;
3729 		int cmp;
3730 
3731 		err = got_ref_resolve(&stored_id, repo, commit_ref);
3732 		if (err)
3733 			goto done;
3734 		cmp = got_object_id_cmp(commit_id, stored_id);
3735 		free(stored_id);
3736 		if (cmp != 0) {
3737 			err = got_error(GOT_ERR_REBASE_COMMITID);
3738 			goto done;
3739 		}
3740 	}
3741 
3742 	err = merge_files(worktree, fileindex, fileindex_path,
3743 	    parent_commit_id, commit_id, repo, progress_cb, progress_arg,
3744 	    cancel_cb, cancel_arg);
3745 done:
3746 	got_fileindex_free(fileindex);
3747 	free(fileindex_path);
3748 	if (commit_ref)
3749 		got_ref_close(commit_ref);
3750 	return err;
3751 }
3752 
3753 static const struct got_error *
3754 bump_all_base_commit_ids(struct got_worktree *worktree,
3755     struct got_object_id *base_commit_id)
3756 {
3757 	const struct got_error *err = NULL, *sync_err;
3758 	struct got_fileindex *fileindex;
3759 	char *fileindex_path;
3760 	struct bump_base_commit_id_arg bbc_arg;
3761 
3762 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3763 	if (err)
3764 		return err;
3765 
3766 	bbc_arg.base_commit_id = base_commit_id;
3767 	bbc_arg.entry_name = NULL;
3768 	bbc_arg.path = "";
3769 	bbc_arg.path_len = 0;
3770 	bbc_arg.progress_cb = NULL;
3771 	bbc_arg.progress_arg = NULL;
3772 	err = got_fileindex_for_each_entry_safe(fileindex,
3773 	    bump_base_commit_id, &bbc_arg);
3774 
3775 	sync_err = sync_fileindex(fileindex, fileindex_path);
3776 	if (sync_err && err == NULL)
3777 		err = sync_err;
3778 
3779 	got_fileindex_free(fileindex);
3780 	free(fileindex_path);
3781 	return err;
3782 }
3783 
3784 const struct got_error *
3785 got_worktree_rebase_commit(struct got_object_id **new_commit_id,
3786     struct got_worktree *worktree, struct got_reference *tmp_branch,
3787     struct got_commit_object *orig_commit,
3788     struct got_object_id *orig_commit_id, struct got_repository *repo)
3789 {
3790 	const struct got_error *err;
3791 	char *commit_ref_name = NULL;
3792 	struct got_reference *commit_ref = NULL;
3793 	struct got_object_id *commit_id = NULL;
3794 
3795 	/* Work tree is locked/unlocked during rebase prepartion/teardown. */
3796 
3797 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3798 	if (err)
3799 		goto done;
3800 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3801 	if (err)
3802 		goto done;
3803 	err = got_ref_resolve(&commit_id, repo, commit_ref);
3804 	if (err)
3805 		goto done;
3806 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
3807 		err = got_error(GOT_ERR_REBASE_COMMITID);
3808 		goto done;
3809 	}
3810 
3811 	err = got_worktree_commit(new_commit_id, worktree, NULL,
3812 	    got_object_commit_get_author(orig_commit),
3813 	    got_object_commit_get_committer(orig_commit),
3814 	    collect_rebase_commit_msg, orig_commit,
3815 	    rebase_status, NULL, repo);
3816 	if (err) {
3817 		if (err->code == GOT_ERR_COMMIT_NO_CHANGES) {
3818 			/* No-op change; commit will be elided. */
3819 			err = got_ref_delete(commit_ref, repo);
3820 			if (err)
3821 				goto done;
3822 			err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3823 		}
3824 		goto done;
3825 	}
3826 
3827 	/* Prevent out-of-date errors during rebase of subsequent commits. */
3828 	err = bump_all_base_commit_ids(worktree, *new_commit_id);
3829 	if (err)
3830 		goto done;
3831 
3832 	err = got_ref_delete(commit_ref, repo);
3833 	if (err)
3834 		goto done;
3835 
3836 	err = got_ref_change_ref(tmp_branch, *new_commit_id);
3837 done:
3838 	free(commit_ref_name);
3839 	if (commit_ref)
3840 		got_ref_close(commit_ref);
3841 	if (err) {
3842 		free(*new_commit_id);
3843 		*new_commit_id = NULL;
3844 	}
3845 	return err;
3846 }
3847 
3848 const struct got_error *
3849 got_worktree_rebase_postpone(struct got_worktree *worktree)
3850 {
3851 	return lock_worktree(worktree, LOCK_SH);
3852 }
3853 
3854 static const struct got_error *
3855 delete_ref(const char *name, struct got_repository *repo)
3856 {
3857 	const struct got_error *err;
3858 	struct got_reference *ref;
3859 
3860 	err = got_ref_open(&ref, repo, name, 0);
3861 	if (err) {
3862 		if (err->code == GOT_ERR_NOT_REF)
3863 			return NULL;
3864 		return err;
3865 	}
3866 
3867 	err = got_ref_delete(ref, repo);
3868 	got_ref_close(ref);
3869 	return err;
3870 }
3871 
3872 static const struct got_error *
3873 delete_rebase_refs(struct got_worktree *worktree, struct got_repository *repo)
3874 {
3875 	const struct got_error *err;
3876 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
3877 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
3878 
3879 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3880 	if (err)
3881 		goto done;
3882 	err = delete_ref(tmp_branch_name, repo);
3883 	if (err)
3884 		goto done;
3885 
3886 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3887 	if (err)
3888 		goto done;
3889 	err = delete_ref(new_base_branch_ref_name, repo);
3890 	if (err)
3891 		goto done;
3892 
3893 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3894 	if (err)
3895 		goto done;
3896 	err = delete_ref(branch_ref_name, repo);
3897 	if (err)
3898 		goto done;
3899 
3900 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3901 	if (err)
3902 		goto done;
3903 	err = delete_ref(commit_ref_name, repo);
3904 	if (err)
3905 		goto done;
3906 
3907 done:
3908 	free(tmp_branch_name);
3909 	free(new_base_branch_ref_name);
3910 	free(branch_ref_name);
3911 	free(commit_ref_name);
3912 	return err;
3913 }
3914 
3915 const struct got_error *
3916 got_worktree_rebase_complete(struct got_worktree *worktree,
3917     struct got_reference *new_base_branch, struct got_reference *tmp_branch,
3918     struct got_reference *rebased_branch,
3919     struct got_repository *repo)
3920 {
3921 	const struct got_error *err, *unlockerr;
3922 	struct got_object_id *new_head_commit_id = NULL;
3923 
3924 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
3925 	if (err)
3926 		return err;
3927 
3928 	err = got_ref_change_ref(rebased_branch, new_head_commit_id);
3929 	if (err)
3930 		goto done;
3931 
3932 	err = got_ref_write(rebased_branch, repo);
3933 	if (err)
3934 		goto done;
3935 
3936 	err = got_worktree_set_head_ref(worktree, rebased_branch);
3937 	if (err)
3938 		goto done;
3939 
3940 	err = delete_rebase_refs(worktree, repo);
3941 done:
3942 	free(new_head_commit_id);
3943 	unlockerr = lock_worktree(worktree, LOCK_SH);
3944 	if (unlockerr && err == NULL)
3945 		err = unlockerr;
3946 	return err;
3947 }
3948 
3949 struct collect_revertible_paths_arg {
3950 	struct got_pathlist_head *revertible_paths;
3951 	struct got_worktree *worktree;
3952 };
3953 
3954 static const struct got_error *
3955 collect_revertible_paths(void *arg, unsigned char status, const char *relpath,
3956     struct got_object_id *blob_id, struct got_object_id *commit_id)
3957 {
3958 	struct collect_revertible_paths_arg *a = arg;
3959 	const struct got_error *err = NULL;
3960 	struct got_pathlist_entry *new = NULL;
3961 	char *path = NULL;
3962 
3963 	if (status != GOT_STATUS_ADD &&
3964 	    status != GOT_STATUS_DELETE &&
3965 	    status != GOT_STATUS_MODIFY &&
3966 	    status != GOT_STATUS_CONFLICT &&
3967 	    status != GOT_STATUS_MISSING)
3968 		return NULL;
3969 
3970 	if (asprintf(&path, "%s/%s", a->worktree->root_path, relpath) == -1)
3971 		return got_error_from_errno("asprintf");
3972 
3973 	err = got_pathlist_insert(&new, a->revertible_paths, path, NULL);
3974 	if (err || new == NULL)
3975 		free(path);
3976 	return err;
3977 }
3978 
3979 const struct got_error *
3980 got_worktree_rebase_abort(struct got_worktree *worktree,
3981     struct got_repository *repo, struct got_reference *new_base_branch,
3982      got_worktree_checkout_cb progress_cb, void *progress_arg)
3983 {
3984 	const struct got_error *err, *unlockerr;
3985 	struct got_reference *resolved = NULL;
3986 	struct got_object_id *commit_id = NULL;
3987 	struct got_fileindex *fileindex = NULL;
3988 	char *fileindex_path = NULL;
3989 	struct got_pathlist_head revertible_paths;
3990 	struct got_pathlist_entry *pe;
3991 	struct collect_revertible_paths_arg crp_arg;
3992 
3993 	TAILQ_INIT(&revertible_paths);
3994 
3995 	err = lock_worktree(worktree, LOCK_EX);
3996 	if (err)
3997 		return err;
3998 
3999 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
4000 	if (err)
4001 		goto done;
4002 
4003 	err = got_ref_open(&resolved, repo,
4004 	    got_ref_get_symref_target(new_base_branch), 0);
4005 	if (err)
4006 		goto done;
4007 
4008 	err = got_worktree_set_head_ref(worktree, resolved);
4009 	if (err)
4010 		goto done;
4011 
4012 	/*
4013 	 * XXX commits to the base branch could have happened while
4014 	 * we were busy rebasing; should we store the original commit ID
4015 	 * when rebase begins and read it back here?
4016 	 */
4017 	err = got_ref_resolve(&commit_id, repo, resolved);
4018 	if (err)
4019 		goto done;
4020 
4021 	err = got_worktree_set_base_commit_id(worktree, repo, commit_id);
4022 	if (err)
4023 		goto done;
4024 
4025 	err = got_worktree_checkout_files(worktree, "", repo, progress_cb,
4026 	    progress_arg, NULL, NULL);
4027 	if (err)
4028 		goto done;
4029 
4030 	crp_arg.revertible_paths = &revertible_paths;
4031 	crp_arg.worktree = worktree;
4032 	err = got_worktree_status(worktree, "", repo,
4033 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4034 	if (err)
4035 		goto done;
4036 
4037 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4038 		err = revert_file(worktree, fileindex, pe->path,
4039 		    progress_cb, progress_arg, repo);
4040 		if (err)
4041 			goto done;
4042 	}
4043 
4044 	err = delete_rebase_refs(worktree, repo);
4045 done:
4046 	got_ref_close(resolved);
4047 	free(commit_id);
4048 	if (fileindex)
4049 		got_fileindex_free(fileindex);
4050 	free(fileindex_path);
4051 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4052 		free((char *)pe->path);
4053 	got_pathlist_free(&revertible_paths);
4054 
4055 	unlockerr = lock_worktree(worktree, LOCK_SH);
4056 	if (unlockerr && err == NULL)
4057 		err = unlockerr;
4058 	return err;
4059 }