1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/stat.h>
18 #include <sys/limits.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 
22 #include <dirent.h>
23 #include <stddef.h>
24 #include <string.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <fcntl.h>
28 #include <errno.h>
29 #include <unistd.h>
30 #include <sha1.h>
31 #include <zlib.h>
32 #include <fnmatch.h>
33 #include <libgen.h>
34 #include <uuid.h>
35 #include <util.h>
36 
37 #include "got_error.h"
38 #include "got_repository.h"
39 #include "got_reference.h"
40 #include "got_object.h"
41 #include "got_path.h"
42 #include "got_worktree.h"
43 #include "got_opentemp.h"
44 #include "got_diff.h"
45 
46 #include "got_lib_worktree.h"
47 #include "got_lib_sha1.h"
48 #include "got_lib_fileindex.h"
49 #include "got_lib_inflate.h"
50 #include "got_lib_delta.h"
51 #include "got_lib_object.h"
52 #include "got_lib_object_parse.h"
53 #include "got_lib_object_create.h"
54 #include "got_lib_object_idset.h"
55 #include "got_lib_diff.h"
56 
57 #ifndef MIN
58 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
59 #endif
60 
61 static const struct got_error *
62 create_meta_file(const char *path_got, const char *name, const char *content)
63 {
64 	const struct got_error *err = NULL;
65 	char *path;
66 
67 	if (asprintf(&path, "%s/%s", path_got, name) == -1)
68 		return got_error_from_errno("asprintf");
69 
70 	err = got_path_create_file(path, content);
71 	free(path);
72 	return err;
73 }
74 
75 static const struct got_error *
76 update_meta_file(const char *path_got, const char *name, const char *content)
77 {
78 	const struct got_error *err = NULL;
79 	FILE *tmpfile = NULL;
80 	char *tmppath = NULL;
81 	char *path = NULL;
82 
83 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
84 		err = got_error_from_errno("asprintf");
85 		path = NULL;
86 		goto done;
87 	}
88 
89 	err = got_opentemp_named(&tmppath, &tmpfile, path);
90 	if (err)
91 		goto done;
92 
93 	if (content) {
94 		int len = fprintf(tmpfile, "%s\n", content);
95 		if (len != strlen(content) + 1) {
96 			err = got_error_from_errno2("fprintf", tmppath);
97 			goto done;
98 		}
99 	}
100 
101 	if (rename(tmppath, path) != 0) {
102 		err = got_error_from_errno3("rename", tmppath, path);
103 		unlink(tmppath);
104 		goto done;
105 	}
106 
107 done:
108 	if (fclose(tmpfile) != 0 && err == NULL)
109 		err = got_error_from_errno2("fclose", tmppath);
110 	free(tmppath);
111 	return err;
112 }
113 
114 static const struct got_error *
115 read_meta_file(char **content, const char *path_got, const char *name)
116 {
117 	const struct got_error *err = NULL;
118 	char *path;
119 	int fd = -1;
120 	ssize_t n;
121 	struct stat sb;
122 
123 	*content = NULL;
124 
125 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
126 		err = got_error_from_errno("asprintf");
127 		path = NULL;
128 		goto done;
129 	}
130 
131 	fd = open(path, O_RDONLY | O_NOFOLLOW);
132 	if (fd == -1) {
133 		if (errno == ENOENT)
134 			err = got_error(GOT_ERR_WORKTREE_META);
135 		else
136 			err = got_error_from_errno2("open", path);
137 		goto done;
138 	}
139 	if (flock(fd, LOCK_SH | LOCK_NB) == -1) {
140 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
141 		    : got_error_from_errno2("flock", path));
142 		goto done;
143 	}
144 
145 	if (lstat(path, &sb) != 0) {
146 		err = got_error_from_errno2("lstat", path);
147 		goto done;
148 	}
149 	*content = calloc(1, sb.st_size);
150 	if (*content == NULL) {
151 		err = got_error_from_errno("calloc");
152 		goto done;
153 	}
154 
155 	n = read(fd, *content, sb.st_size);
156 	if (n != sb.st_size) {
157 		err = (n == -1 ? got_error_from_errno2("read", path) :
158 		    got_error(GOT_ERR_WORKTREE_META));
159 		goto done;
160 	}
161 	if ((*content)[sb.st_size - 1] != '\n') {
162 		err = got_error(GOT_ERR_WORKTREE_META);
163 		goto done;
164 	}
165 	(*content)[sb.st_size - 1] = '\0';
166 
167 done:
168 	if (fd != -1 && close(fd) == -1 && err == NULL)
169 		err = got_error_from_errno2("close", path_got);
170 	free(path);
171 	if (err) {
172 		free(*content);
173 		*content = NULL;
174 	}
175 	return err;
176 }
177 
178 static const struct got_error *
179 write_head_ref(const char *path_got, struct got_reference *head_ref)
180 {
181 	const struct got_error *err = NULL;
182 	char *refstr = NULL;
183 
184 	if (got_ref_is_symbolic(head_ref)) {
185 		refstr = got_ref_to_str(head_ref);
186 		if (refstr == NULL)
187 			return got_error_from_errno("got_ref_to_str");
188 	} else {
189 		refstr = strdup(got_ref_get_name(head_ref));
190 		if (refstr == NULL)
191 			return got_error_from_errno("strdup");
192 	}
193 	err = update_meta_file(path_got, GOT_WORKTREE_HEAD_REF, refstr);
194 	free(refstr);
195 	return err;
196 }
197 
198 const struct got_error *
199 got_worktree_init(const char *path, struct got_reference *head_ref,
200     const char *prefix, struct got_repository *repo)
201 {
202 	const struct got_error *err = NULL;
203 	struct got_object_id *commit_id = NULL;
204 	uuid_t uuid;
205 	uint32_t uuid_status;
206 	int obj_type;
207 	char *path_got = NULL;
208 	char *formatstr = NULL;
209 	char *absprefix = NULL;
210 	char *basestr = NULL;
211 	char *uuidstr = NULL;
212 
213 	if (strcmp(path, got_repo_get_path(repo)) == 0) {
214 		err = got_error(GOT_ERR_WORKTREE_REPO);
215 		goto done;
216 	}
217 
218 	err = got_ref_resolve(&commit_id, repo, head_ref);
219 	if (err)
220 		return err;
221 	err = got_object_get_type(&obj_type, repo, commit_id);
222 	if (err)
223 		return err;
224 	if (obj_type != GOT_OBJ_TYPE_COMMIT)
225 		return got_error(GOT_ERR_OBJ_TYPE);
226 
227 	if (!got_path_is_absolute(prefix)) {
228 		if (asprintf(&absprefix, "/%s", prefix) == -1)
229 			return got_error_from_errno("asprintf");
230 	}
231 
232 	/* Create top-level directory (may already exist). */
233 	if (mkdir(path, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
234 		err = got_error_from_errno2("mkdir", path);
235 		goto done;
236 	}
237 
238 	/* Create .got directory (may already exist). */
239 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
240 		err = got_error_from_errno("asprintf");
241 		goto done;
242 	}
243 	if (mkdir(path_got, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
244 		err = got_error_from_errno2("mkdir", path_got);
245 		goto done;
246 	}
247 
248 	/* Create an empty lock file. */
249 	err = create_meta_file(path_got, GOT_WORKTREE_LOCK, NULL);
250 	if (err)
251 		goto done;
252 
253 	/* Create an empty file index. */
254 	err = create_meta_file(path_got, GOT_WORKTREE_FILE_INDEX, NULL);
255 	if (err)
256 		goto done;
257 
258 	/* Write the HEAD reference. */
259 	err = write_head_ref(path_got, head_ref);
260 	if (err)
261 		goto done;
262 
263 	/* Record our base commit. */
264 	err = got_object_id_str(&basestr, commit_id);
265 	if (err)
266 		goto done;
267 	err = create_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, basestr);
268 	if (err)
269 		goto done;
270 
271 	/* Store path to repository. */
272 	err = create_meta_file(path_got, GOT_WORKTREE_REPOSITORY,
273 	    got_repo_get_path(repo));
274 	if (err)
275 		goto done;
276 
277 	/* Store in-repository path prefix. */
278 	err = create_meta_file(path_got, GOT_WORKTREE_PATH_PREFIX,
279 	    absprefix ? absprefix : prefix);
280 	if (err)
281 		goto done;
282 
283 	/* Generate UUID. */
284 	uuid_create(&uuid, &uuid_status);
285 	if (uuid_status != uuid_s_ok) {
286 		err = got_error_uuid(uuid_status);
287 		goto done;
288 	}
289 	uuid_to_string(&uuid, &uuidstr, &uuid_status);
290 	if (uuid_status != uuid_s_ok) {
291 		err = got_error_uuid(uuid_status);
292 		goto done;
293 	}
294 	err = create_meta_file(path_got, GOT_WORKTREE_UUID, uuidstr);
295 	if (err)
296 		goto done;
297 
298 	/* Stamp work tree with format file. */
299 	if (asprintf(&formatstr, "%d", GOT_WORKTREE_FORMAT_VERSION) == -1) {
300 		err = got_error_from_errno("asprintf");
301 		goto done;
302 	}
303 	err = create_meta_file(path_got, GOT_WORKTREE_FORMAT, formatstr);
304 	if (err)
305 		goto done;
306 
307 done:
308 	free(commit_id);
309 	free(path_got);
310 	free(formatstr);
311 	free(absprefix);
312 	free(basestr);
313 	free(uuidstr);
314 	return err;
315 }
316 
317 static const struct got_error *
318 open_worktree(struct got_worktree **worktree, const char *path)
319 {
320 	const struct got_error *err = NULL;
321 	char *path_got;
322 	char *formatstr = NULL;
323 	char *uuidstr = NULL;
324 	char *path_lock = NULL;
325 	char *base_commit_id_str = NULL;
326 	int version, fd = -1;
327 	const char *errstr;
328 	struct got_repository *repo = NULL;
329 	uint32_t uuid_status;
330 
331 	*worktree = NULL;
332 
333 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
334 		err = got_error_from_errno("asprintf");
335 		path_got = NULL;
336 		goto done;
337 	}
338 
339 	if (asprintf(&path_lock, "%s/%s", path_got, GOT_WORKTREE_LOCK) == -1) {
340 		err = got_error_from_errno("asprintf");
341 		path_lock = NULL;
342 		goto done;
343 	}
344 
345 	fd = open(path_lock, O_RDWR | O_EXLOCK | O_NONBLOCK);
346 	if (fd == -1) {
347 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
348 		    : got_error_from_errno2("open", path_lock));
349 		goto done;
350 	}
351 
352 	err = read_meta_file(&formatstr, path_got, GOT_WORKTREE_FORMAT);
353 	if (err)
354 		goto done;
355 
356 	version = strtonum(formatstr, 1, INT_MAX, &errstr);
357 	if (errstr) {
358 		err = got_error(GOT_ERR_WORKTREE_META);
359 		goto done;
360 	}
361 	if (version != GOT_WORKTREE_FORMAT_VERSION) {
362 		err = got_error(GOT_ERR_WORKTREE_VERS);
363 		goto done;
364 	}
365 
366 	*worktree = calloc(1, sizeof(**worktree));
367 	if (*worktree == NULL) {
368 		err = got_error_from_errno("calloc");
369 		goto done;
370 	}
371 	(*worktree)->lockfd = -1;
372 
373 	(*worktree)->root_path = strdup(path);
374 	if ((*worktree)->root_path == NULL) {
375 		err = got_error_from_errno("strdup");
376 		goto done;
377 	}
378 	err = read_meta_file(&(*worktree)->repo_path, path_got,
379 	    GOT_WORKTREE_REPOSITORY);
380 	if (err)
381 		goto done;
382 
383 	err = read_meta_file(&(*worktree)->path_prefix, path_got,
384 	    GOT_WORKTREE_PATH_PREFIX);
385 	if (err)
386 		goto done;
387 
388 	err = read_meta_file(&base_commit_id_str, path_got,
389 	    GOT_WORKTREE_BASE_COMMIT);
390 	if (err)
391 		goto done;
392 
393 	err = read_meta_file(&uuidstr, path_got, GOT_WORKTREE_UUID);
394 	if (err)
395 		goto done;
396 	uuid_from_string(uuidstr, &(*worktree)->uuid, &uuid_status);
397 	if (uuid_status != uuid_s_ok) {
398 		err = got_error_uuid(uuid_status);
399 		goto done;
400 	}
401 
402 	err = got_repo_open(&repo, (*worktree)->repo_path);
403 	if (err)
404 		goto done;
405 
406 	err = got_object_resolve_id_str(&(*worktree)->base_commit_id, repo,
407 	    base_commit_id_str);
408 	if (err)
409 		goto done;
410 
411 	err = read_meta_file(&(*worktree)->head_ref_name, path_got,
412 	    GOT_WORKTREE_HEAD_REF);
413 done:
414 	if (repo)
415 		got_repo_close(repo);
416 	free(path_got);
417 	free(path_lock);
418 	free(base_commit_id_str);
419 	free(uuidstr);
420 	free(formatstr);
421 	if (err) {
422 		if (fd != -1)
423 			close(fd);
424 		if (*worktree != NULL)
425 			got_worktree_close(*worktree);
426 		*worktree = NULL;
427 	} else
428 		(*worktree)->lockfd = fd;
429 
430 	return err;
431 }
432 
433 const struct got_error *
434 got_worktree_open(struct got_worktree **worktree, const char *path)
435 {
436 	const struct got_error *err = NULL;
437 
438 	do {
439 		err = open_worktree(worktree, path);
440 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT))
441 			return err;
442 		if (*worktree)
443 			return NULL;
444 		path = dirname(path);
445 		if (path == NULL)
446 			return got_error_from_errno2("dirname", path);
447 	} while (!((path[0] == '.' || path[0] == '/') && path[1] == '\0'));
448 
449 	return got_error(GOT_ERR_NOT_WORKTREE);
450 }
451 
452 const struct got_error *
453 got_worktree_close(struct got_worktree *worktree)
454 {
455 	const struct got_error *err = NULL;
456 	free(worktree->root_path);
457 	free(worktree->repo_path);
458 	free(worktree->path_prefix);
459 	free(worktree->base_commit_id);
460 	free(worktree->head_ref_name);
461 	if (worktree->lockfd != -1)
462 		if (close(worktree->lockfd) != 0)
463 			err = got_error_from_errno2("close",
464 			    got_worktree_get_root_path(worktree));
465 	free(worktree);
466 	return err;
467 }
468 
469 const char *
470 got_worktree_get_root_path(struct got_worktree *worktree)
471 {
472 	return worktree->root_path;
473 }
474 
475 const char *
476 got_worktree_get_repo_path(struct got_worktree *worktree)
477 {
478 	return worktree->repo_path;
479 }
480 
481 const char *
482 got_worktree_get_path_prefix(struct got_worktree *worktree)
483 {
484 	return worktree->path_prefix;
485 }
486 
487 const struct got_error *
488 got_worktree_match_path_prefix(int *match, struct got_worktree *worktree,
489     const char *path_prefix)
490 {
491 	char *absprefix = NULL;
492 
493 	if (!got_path_is_absolute(path_prefix)) {
494 		if (asprintf(&absprefix, "/%s", path_prefix) == -1)
495 			return got_error_from_errno("asprintf");
496 	}
497 	*match = (strcmp(absprefix ? absprefix : path_prefix,
498 	    worktree->path_prefix) == 0);
499 	free(absprefix);
500 	return NULL;
501 }
502 
503 const char *
504 got_worktree_get_head_ref_name(struct got_worktree *worktree)
505 {
506 	return worktree->head_ref_name;
507 }
508 
509 const struct got_error *
510 got_worktree_set_head_ref(struct got_worktree *worktree,
511     struct got_reference *head_ref)
512 {
513 	const struct got_error *err = NULL;
514 	char *path_got = NULL, *head_ref_name = NULL;
515 
516 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
517 	    GOT_WORKTREE_GOT_DIR) == -1) {
518 		err = got_error_from_errno("asprintf");
519 		path_got = NULL;
520 		goto done;
521 	}
522 
523 	head_ref_name = strdup(got_ref_get_name(head_ref));
524 	if (head_ref_name == NULL) {
525 		err = got_error_from_errno("strdup");
526 		goto done;
527 	}
528 
529 	err = write_head_ref(path_got, head_ref);
530 	if (err)
531 		goto done;
532 
533 	free(worktree->head_ref_name);
534 	worktree->head_ref_name = head_ref_name;
535 done:
536 	free(path_got);
537 	if (err)
538 		free(head_ref_name);
539 	return err;
540 }
541 
542 struct got_object_id *
543 got_worktree_get_base_commit_id(struct got_worktree *worktree)
544 {
545 	return worktree->base_commit_id;
546 }
547 
548 const struct got_error *
549 got_worktree_set_base_commit_id(struct got_worktree *worktree,
550     struct got_repository *repo, struct got_object_id *commit_id)
551 {
552 	const struct got_error *err;
553 	struct got_object *obj = NULL;
554 	char *id_str = NULL;
555 	char *path_got = NULL;
556 
557 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
558 	    GOT_WORKTREE_GOT_DIR) == -1) {
559 		err = got_error_from_errno("asprintf");
560 		path_got = NULL;
561 		goto done;
562 	}
563 
564 	err = got_object_open(&obj, repo, commit_id);
565 	if (err)
566 		return err;
567 
568 	if (obj->type != GOT_OBJ_TYPE_COMMIT) {
569 		err = got_error(GOT_ERR_OBJ_TYPE);
570 		goto done;
571 	}
572 
573 	/* Record our base commit. */
574 	err = got_object_id_str(&id_str, commit_id);
575 	if (err)
576 		goto done;
577 	err = update_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, id_str);
578 	if (err)
579 		goto done;
580 
581 	free(worktree->base_commit_id);
582 	worktree->base_commit_id = got_object_id_dup(commit_id);
583 	if (worktree->base_commit_id == NULL) {
584 		err = got_error_from_errno("got_object_id_dup");
585 		goto done;
586 	}
587 done:
588 	if (obj)
589 		got_object_close(obj);
590 	free(id_str);
591 	free(path_got);
592 	return err;
593 }
594 
595 static const struct got_error *
596 lock_worktree(struct got_worktree *worktree, int operation)
597 {
598 	if (flock(worktree->lockfd, operation | LOCK_NB) == -1)
599 		return (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
600 		    : got_error_from_errno2("flock",
601 		    got_worktree_get_root_path(worktree)));
602 	return NULL;
603 }
604 
605 static const struct got_error *
606 add_dir_on_disk(struct got_worktree *worktree, const char *path)
607 {
608 	const struct got_error *err = NULL;
609 	char *abspath;
610 
611 	if (asprintf(&abspath, "%s/%s", worktree->root_path, path) == -1)
612 		return got_error_from_errno("asprintf");
613 
614 	err = got_path_mkdir(abspath);
615 	if (err && err->code == GOT_ERR_ERRNO && errno == EEXIST) {
616 		struct stat sb;
617 		err = NULL;
618 		if (lstat(abspath, &sb) == -1) {
619 			err = got_error_from_errno2("lstat", abspath);
620 		} else if (!S_ISDIR(sb.st_mode)) {
621 			/* TODO directory is obstructed; do something */
622 			err = got_error(GOT_ERR_FILE_OBSTRUCTED);
623 		}
624 	}
625 	free(abspath);
626 	return err;
627 }
628 
629 static const struct got_error *
630 check_file_contents_equal(int *same, FILE *f1, FILE *f2)
631 {
632 	const struct got_error *err = NULL;
633 	uint8_t fbuf1[8192];
634 	uint8_t fbuf2[8192];
635 	size_t flen1 = 0, flen2 = 0;
636 
637 	*same = 1;
638 
639 	for (;;) {
640 		flen1 = fread(fbuf1, 1, sizeof(fbuf1), f1);
641 		if (flen1 == 0 && ferror(f1)) {
642 			err = got_error_from_errno("fread");
643 			break;
644 		}
645 		flen2 = fread(fbuf2, 1, sizeof(fbuf2), f2);
646 		if (flen2 == 0 && ferror(f2)) {
647 			err = got_error_from_errno("fread");
648 			break;
649 		}
650 		if (flen1 == 0) {
651 			if (flen2 != 0)
652 				*same = 0;
653 			break;
654 		} else if (flen2 == 0) {
655 			if (flen1 != 0)
656 				*same = 0;
657 			break;
658 		} else if (flen1 == flen2) {
659 			if (memcmp(fbuf1, fbuf2, flen2) != 0) {
660 				*same = 0;
661 				break;
662 			}
663 		} else {
664 			*same = 0;
665 			break;
666 		}
667 	}
668 
669 	return err;
670 }
671 
672 static const struct got_error *
673 check_files_equal(int *same, const char *f1_path, const char *f2_path)
674 {
675 	const struct got_error *err = NULL;
676 	struct stat sb;
677 	size_t size1, size2;
678 	FILE *f1 = NULL, *f2 = NULL;
679 
680 	*same = 1;
681 
682 	if (lstat(f1_path, &sb) != 0) {
683 		err = got_error_from_errno2("lstat", f1_path);
684 		goto done;
685 	}
686 	size1 = sb.st_size;
687 
688 	if (lstat(f2_path, &sb) != 0) {
689 		err = got_error_from_errno2("lstat", f2_path);
690 		goto done;
691 	}
692 	size2 = sb.st_size;
693 
694 	if (size1 != size2) {
695 		*same = 0;
696 		return NULL;
697 	}
698 
699 	f1 = fopen(f1_path, "r");
700 	if (f1 == NULL)
701 		return got_error_from_errno2("open", f1_path);
702 
703 	f2 = fopen(f2_path, "r");
704 	if (f2 == NULL) {
705 		err = got_error_from_errno2("open", f2_path);
706 		goto done;
707 	}
708 
709 	err = check_file_contents_equal(same, f1, f2);
710 done:
711 	if (f1 && fclose(f1) != 0 && err == NULL)
712 		err = got_error_from_errno("fclose");
713 	if (f2 && fclose(f2) != 0 && err == NULL)
714 		err = got_error_from_errno("fclose");
715 
716 	return err;
717 }
718 
719 /*
720  * Perform a 3-way merge where blob_orig acts as the common ancestor,
721  * blob_deriv acts as the first derived version, and the file on disk
722  * acts as the second derived version.
723  */
724 static const struct got_error *
725 merge_blob(int *local_changes_subsumed, struct got_worktree *worktree,
726     struct got_blob_object *blob_orig, const char *ondisk_path,
727     const char *path, uint16_t st_mode, struct got_blob_object *blob_deriv,
728     struct got_object_id *deriv_base_commit_id,
729     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
730     void *progress_arg)
731 {
732 	const struct got_error *err = NULL;
733 	int merged_fd = -1;
734 	FILE *f_deriv = NULL, *f_orig = NULL;
735 	char *blob_deriv_path = NULL, *blob_orig_path = NULL;
736 	char *merged_path = NULL, *base_path = NULL;
737 	char *id_str = NULL;
738 	char *label_deriv = NULL;
739 	int overlapcnt = 0;
740 	char *parent;
741 
742 	*local_changes_subsumed = 0;
743 
744 	parent = dirname(ondisk_path);
745 	if (parent == NULL)
746 		return got_error_from_errno2("dirname", ondisk_path);
747 
748 	if (asprintf(&base_path, "%s/got-merged", parent) == -1)
749 		return got_error_from_errno("asprintf");
750 
751 	err = got_opentemp_named_fd(&merged_path, &merged_fd, base_path);
752 	if (err)
753 		goto done;
754 
755 	free(base_path);
756 	if (asprintf(&base_path, "%s/got-merge-blob-deriv", parent) == -1) {
757 		err = got_error_from_errno("asprintf");
758 		base_path = NULL;
759 		goto done;
760 	}
761 
762 	err = got_opentemp_named(&blob_deriv_path, &f_deriv, base_path);
763 	if (err)
764 		goto done;
765 	err = got_object_blob_dump_to_file(NULL, NULL, NULL, f_deriv,
766 	    blob_deriv);
767 	if (err)
768 		goto done;
769 
770 	free(base_path);
771 	if (asprintf(&base_path, "%s/got-merge-blob-orig", parent) == -1) {
772 		err = got_error_from_errno("asprintf");
773 		base_path = NULL;
774 		goto done;
775 	}
776 
777 	err = got_opentemp_named(&blob_orig_path, &f_orig, base_path);
778 	if (err)
779 		goto done;
780 	if (blob_orig) {
781 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f_orig,
782 		    blob_orig);
783 		if (err)
784 			goto done;
785 	} else {
786 		/*
787 		 * If the file has no blob, this is an "add vs add" conflict,
788 		 * and we simply use an empty ancestor file to make both files
789 		 * appear in the merged result in their entirety.
790 		 */
791 	}
792 
793 	err = got_object_id_str(&id_str, deriv_base_commit_id);
794 	if (err)
795 		goto done;
796 	if (asprintf(&label_deriv, "commit %s", id_str) == -1) {
797 		err = got_error_from_errno("asprintf");
798 		goto done;
799 	}
800 
801 	err = got_merge_diff3(&overlapcnt, merged_fd, blob_deriv_path,
802 	    blob_orig_path, ondisk_path, label_deriv, path);
803 	if (err)
804 		goto done;
805 
806 	err = (*progress_cb)(progress_arg,
807 	    overlapcnt > 0 ? GOT_STATUS_CONFLICT : GOT_STATUS_MERGE, path);
808 	if (err)
809 		goto done;
810 
811 	if (fsync(merged_fd) != 0) {
812 		err = got_error_from_errno("fsync");
813 		goto done;
814 	}
815 
816 	/* Check if a clean merge has subsumed all local changes. */
817 	if (overlapcnt == 0) {
818 		err = check_files_equal(local_changes_subsumed, blob_deriv_path,
819 		    merged_path);
820 		if (err)
821 			goto done;
822 	}
823 
824 	if (chmod(merged_path, st_mode) != 0) {
825 		err = got_error_from_errno2("chmod", merged_path);
826 		goto done;
827 	}
828 
829 	if (rename(merged_path, ondisk_path) != 0) {
830 		err = got_error_from_errno3("rename", merged_path,
831 		    ondisk_path);
832 		unlink(merged_path);
833 		goto done;
834 	}
835 
836 done:
837 	if (merged_fd != -1 && close(merged_fd) != 0 && err == NULL)
838 		err = got_error_from_errno("close");
839 	if (f_deriv && fclose(f_deriv) != 0 && err == NULL)
840 		err = got_error_from_errno("fclose");
841 	if (f_orig && fclose(f_orig) != 0 && err == NULL)
842 		err = got_error_from_errno("fclose");
843 	free(merged_path);
844 	free(base_path);
845 	if (blob_deriv_path) {
846 		unlink(blob_deriv_path);
847 		free(blob_deriv_path);
848 	}
849 	if (blob_orig_path) {
850 		unlink(blob_orig_path);
851 		free(blob_orig_path);
852 	}
853 	free(id_str);
854 	free(label_deriv);
855 	return err;
856 }
857 
858 static const struct got_error *
859 update_blob_fileindex_entry(struct got_worktree *worktree,
860     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
861     const char *ondisk_path, const char *path, struct got_blob_object *blob,
862     int update_timestamps)
863 {
864 	const struct got_error *err = NULL;
865 
866 	if (ie == NULL)
867 		ie = got_fileindex_entry_get(fileindex, path);
868 	if (ie)
869 		err = got_fileindex_entry_update(ie, ondisk_path,
870 		    blob->id.sha1, worktree->base_commit_id->sha1,
871 		    update_timestamps);
872 	else {
873 		struct got_fileindex_entry *new_ie;
874 		err = got_fileindex_entry_alloc(&new_ie, ondisk_path,
875 		    path, blob->id.sha1, worktree->base_commit_id->sha1);
876 		if (!err)
877 			err = got_fileindex_entry_add(fileindex, new_ie);
878 	}
879 	return err;
880 }
881 
882 static const struct got_error *
883 install_blob(struct got_worktree *worktree, const char *ondisk_path,
884    const char *path, uint16_t te_mode, uint16_t st_mode,
885    struct got_blob_object *blob, int restoring_missing_file,
886    int reverting_versioned_file, struct got_repository *repo,
887    got_worktree_checkout_cb progress_cb, void *progress_arg)
888 {
889 	const struct got_error *err = NULL;
890 	int fd = -1;
891 	size_t len, hdrlen;
892 	int update = 0;
893 	char *tmppath = NULL;
894 
895 	fd = open(ondisk_path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
896 	    GOT_DEFAULT_FILE_MODE);
897 	if (fd == -1) {
898 		if (errno == ENOENT) {
899 			char *parent = dirname(path);
900 			if (parent == NULL)
901 				return got_error_from_errno2("dirname", path);
902 			err = add_dir_on_disk(worktree, parent);
903 			if (err)
904 				return err;
905 			fd = open(ondisk_path,
906 			    O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
907 			    GOT_DEFAULT_FILE_MODE);
908 			if (fd == -1)
909 				return got_error_from_errno2("open",
910 				    ondisk_path);
911 		} else if (errno == EEXIST) {
912 			if (!S_ISREG(st_mode)) {
913 				/* TODO file is obstructed; do something */
914 				err = got_error(GOT_ERR_FILE_OBSTRUCTED);
915 				goto done;
916 			} else {
917 				err = got_opentemp_named_fd(&tmppath, &fd,
918 				    ondisk_path);
919 				if (err)
920 					goto done;
921 				update = 1;
922 			}
923 		} else
924 			return got_error_from_errno2("open", ondisk_path);
925 	}
926 
927 	if (restoring_missing_file)
928 		err = (*progress_cb)(progress_arg, GOT_STATUS_MISSING, path);
929 	else if (reverting_versioned_file)
930 		err = (*progress_cb)(progress_arg, GOT_STATUS_REVERT, path);
931 	else
932 		err = (*progress_cb)(progress_arg,
933 		    update ? GOT_STATUS_UPDATE : GOT_STATUS_ADD, path);
934 	if (err)
935 		goto done;
936 
937 	hdrlen = got_object_blob_get_hdrlen(blob);
938 	do {
939 		const uint8_t *buf = got_object_blob_get_read_buf(blob);
940 		err = got_object_blob_read_block(&len, blob);
941 		if (err)
942 			break;
943 		if (len > 0) {
944 			/* Skip blob object header first time around. */
945 			ssize_t outlen = write(fd, buf + hdrlen, len - hdrlen);
946 			if (outlen == -1) {
947 				err = got_error_from_errno("write");
948 				goto done;
949 			} else if (outlen != len - hdrlen) {
950 				err = got_error(GOT_ERR_IO);
951 				goto done;
952 			}
953 			hdrlen = 0;
954 		}
955 	} while (len != 0);
956 
957 	if (fsync(fd) != 0) {
958 		err = got_error_from_errno("fsync");
959 		goto done;
960 	}
961 
962 	if (update) {
963 		if (rename(tmppath, ondisk_path) != 0) {
964 			err = got_error_from_errno3("rename", tmppath,
965 			    ondisk_path);
966 			unlink(tmppath);
967 			goto done;
968 		}
969 	}
970 
971 	if (te_mode & S_IXUSR) {
972 		if (chmod(ondisk_path, st_mode | S_IXUSR) == -1) {
973 			err = got_error_from_errno2("chmod", ondisk_path);
974 			goto done;
975 		}
976 	} else {
977 		if (chmod(ondisk_path, st_mode & ~S_IXUSR) == -1) {
978 			err = got_error_from_errno2("chmod", ondisk_path);
979 			goto done;
980 		}
981 	}
982 
983 done:
984 	if (fd != -1 && close(fd) != 0 && err == NULL)
985 		err = got_error_from_errno("close");
986 	free(tmppath);
987 	return err;
988 }
989 
990 /* Upgrade STATUS_MODIFY to STATUS_CONFLICT if a conflict marker is found. */
991 static const struct got_error *
992 get_modified_file_content_status(unsigned char *status, FILE *f)
993 {
994 	const struct got_error *err = NULL;
995 	const char *markers[3] = {
996 		GOT_DIFF_CONFLICT_MARKER_BEGIN,
997 		GOT_DIFF_CONFLICT_MARKER_SEP,
998 		GOT_DIFF_CONFLICT_MARKER_END
999 	};
1000 	int i = 0;
1001 	char *line;
1002 	size_t len;
1003 	const char delim[3] = {'\0', '\0', '\0'};
1004 
1005 	while (*status == GOT_STATUS_MODIFY) {
1006 		line = fparseln(f, &len, NULL, delim, 0);
1007 		if (line == NULL) {
1008 			if (feof(f))
1009 				break;
1010 			err = got_ferror(f, GOT_ERR_IO);
1011 			break;
1012 		}
1013 
1014 		if (strncmp(line, markers[i], strlen(markers[i])) == 0) {
1015 			if (strcmp(markers[i], GOT_DIFF_CONFLICT_MARKER_END)
1016 			    == 0)
1017 				*status = GOT_STATUS_CONFLICT;
1018 			else
1019 				i++;
1020 		}
1021 	}
1022 
1023 	return err;
1024 }
1025 
1026 static int
1027 stat_info_differs(struct got_fileindex_entry *ie, struct stat *sb)
1028 {
1029 	return !(ie->ctime_sec == sb->st_ctime &&
1030 	    ie->ctime_nsec == sb->st_ctimensec &&
1031 	    ie->mtime_sec == sb->st_mtime &&
1032 	    ie->mtime_nsec == sb->st_mtimensec &&
1033 	    ie->size == (sb->st_size & 0xffffffff));
1034 }
1035 
1036 static const struct got_error *
1037 get_file_status(unsigned char *status, struct stat *sb,
1038     struct got_fileindex_entry *ie, const char *abspath,
1039     struct got_repository *repo)
1040 {
1041 	const struct got_error *err = NULL;
1042 	struct got_object_id id;
1043 	size_t hdrlen;
1044 	FILE *f = NULL;
1045 	uint8_t fbuf[8192];
1046 	struct got_blob_object *blob = NULL;
1047 	size_t flen, blen;
1048 
1049 	*status = GOT_STATUS_NO_CHANGE;
1050 
1051 	if (lstat(abspath, sb) == -1) {
1052 		if (errno == ENOENT) {
1053 			if (got_fileindex_entry_has_file_on_disk(ie))
1054 				*status = GOT_STATUS_MISSING;
1055 			else
1056 				*status = GOT_STATUS_DELETE;
1057 			return NULL;
1058 		}
1059 		return got_error_from_errno2("lstat", abspath);
1060 	}
1061 
1062 	if (!S_ISREG(sb->st_mode)) {
1063 		*status = GOT_STATUS_OBSTRUCTED;
1064 		return NULL;
1065 	}
1066 
1067 	if (!got_fileindex_entry_has_file_on_disk(ie)) {
1068 		*status = GOT_STATUS_DELETE;
1069 		return NULL;
1070 	} else if (!got_fileindex_entry_has_blob(ie)) {
1071 		*status = GOT_STATUS_ADD;
1072 		return NULL;
1073 	}
1074 
1075 	if (!stat_info_differs(ie, sb))
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 /*
1134  * Update timestamps in the file index if a file is unmodified and
1135  * we had to run a full content comparison to find out.
1136  */
1137 static const struct got_error *
1138 sync_timestamps(char *ondisk_path, unsigned char status,
1139     struct got_fileindex_entry *ie, struct stat *sb)
1140 {
1141 	if (status == GOT_STATUS_NO_CHANGE && stat_info_differs(ie, sb))
1142 		return got_fileindex_entry_update(ie, ondisk_path,
1143 		    ie->blob_sha1, ie->commit_sha1, 1);
1144 
1145 	return NULL;
1146 }
1147 
1148 static const struct got_error *
1149 update_blob(struct got_worktree *worktree,
1150     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
1151     struct got_tree_entry *te, const char *path,
1152     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1153     void *progress_arg)
1154 {
1155 	const struct got_error *err = NULL;
1156 	struct got_blob_object *blob = NULL;
1157 	char *ondisk_path;
1158 	unsigned char status = GOT_STATUS_NO_CHANGE;
1159 	struct stat sb;
1160 
1161 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
1162 		return got_error_from_errno("asprintf");
1163 
1164 	if (ie) {
1165 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1166 		if (err)
1167 			goto done;
1168 		if (status == GOT_STATUS_MISSING || status == GOT_STATUS_DELETE)
1169 			sb.st_mode = got_fileindex_perms_to_st(ie);
1170 	} else
1171 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
1172 
1173 	if (status == GOT_STATUS_OBSTRUCTED) {
1174 		err = (*progress_cb)(progress_arg, status, path);
1175 		goto done;
1176 	}
1177 
1178 	if (ie && status != GOT_STATUS_MISSING) {
1179 		if (got_fileindex_entry_has_commit(ie) &&
1180 		    memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
1181 		    SHA1_DIGEST_LENGTH) == 0) {
1182 			err = sync_timestamps(ondisk_path, status, ie, &sb);
1183 			if (err)
1184 				goto done;
1185 			err = (*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
1186 			    path);
1187 			goto done;
1188 		}
1189 		if (got_fileindex_entry_has_blob(ie) &&
1190 		    memcmp(ie->blob_sha1, te->id->sha1,
1191 		    SHA1_DIGEST_LENGTH) == 0) {
1192 			err = sync_timestamps(ondisk_path, status, ie, &sb);
1193 			goto done;
1194 		}
1195 	}
1196 
1197 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
1198 	if (err)
1199 		goto done;
1200 
1201 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_ADD) {
1202 		int update_timestamps;
1203 		struct got_blob_object *blob2 = NULL;
1204 		if (got_fileindex_entry_has_blob(ie)) {
1205 			struct got_object_id id2;
1206 			memcpy(id2.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1207 			err = got_object_open_as_blob(&blob2, repo, &id2, 8192);
1208 			if (err)
1209 				goto done;
1210 		}
1211 		err = merge_blob(&update_timestamps, worktree, blob2,
1212 		    ondisk_path, path, sb.st_mode, blob,
1213 		    worktree->base_commit_id, repo,
1214 		    progress_cb, progress_arg);
1215 		if (blob2)
1216 			got_object_blob_close(blob2);
1217 		/*
1218 		 * Do not update timestamps of files with local changes.
1219 		 * Otherwise, a future status walk would treat them as
1220 		 * unmodified files again.
1221 		 */
1222 		err = got_fileindex_entry_update(ie, ondisk_path,
1223 		    blob->id.sha1, worktree->base_commit_id->sha1,
1224 		    update_timestamps);
1225 	} else if (status == GOT_STATUS_DELETE) {
1226 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, path);
1227 		if (err)
1228 			goto done;
1229 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1230 		    ondisk_path, path, blob, 0);
1231 		if (err)
1232 			goto done;
1233 	} else {
1234 		err = install_blob(worktree, ondisk_path, path, te->mode,
1235 		    sb.st_mode, blob, status == GOT_STATUS_MISSING, 0,
1236 		    repo, progress_cb, progress_arg);
1237 		if (err)
1238 			goto done;
1239 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1240 		    ondisk_path, path, blob, 1);
1241 		if (err)
1242 			goto done;
1243 	}
1244 	got_object_blob_close(blob);
1245 done:
1246 	free(ondisk_path);
1247 	return err;
1248 }
1249 
1250 static const struct got_error *
1251 remove_ondisk_file(const char *root_path, const char *path)
1252 {
1253 	const struct got_error *err = NULL;
1254 	char *ondisk_path = NULL;
1255 
1256 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
1257 		return got_error_from_errno("asprintf");
1258 
1259 	if (unlink(ondisk_path) == -1) {
1260 		if (errno != ENOENT)
1261 			err = got_error_from_errno2("unlink", ondisk_path);
1262 	} else {
1263 		char *parent = dirname(ondisk_path);
1264 		while (parent && strcmp(parent, root_path) != 0) {
1265 			if (rmdir(parent) == -1) {
1266 				if (errno != ENOTEMPTY)
1267 					err = got_error_from_errno2("rmdir",
1268 					    parent);
1269 				break;
1270 			}
1271 			parent = dirname(parent);
1272 		}
1273 	}
1274 	free(ondisk_path);
1275 	return err;
1276 }
1277 
1278 static const struct got_error *
1279 delete_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
1280     struct got_fileindex_entry *ie, struct got_repository *repo,
1281     got_worktree_checkout_cb progress_cb, void *progress_arg)
1282 {
1283 	const struct got_error *err = NULL;
1284 	unsigned char status;
1285 	struct stat sb;
1286 	char *ondisk_path;
1287 
1288 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, ie->path)
1289 	    == -1)
1290 		return got_error_from_errno("asprintf");
1291 
1292 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1293 	if (err)
1294 		return err;
1295 
1296 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_CONFLICT ||
1297 	    status == GOT_STATUS_ADD) {
1298 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, ie->path);
1299 		if (err)
1300 			return err;
1301 		/*
1302 		 * Preserve the working file and change the deleted blob's
1303 		 * entry into a schedule-add entry.
1304 		 */
1305 		err = got_fileindex_entry_update(ie, ondisk_path, NULL, NULL,
1306 		    0);
1307 		if (err)
1308 			return err;
1309 	} else {
1310 		err = (*progress_cb)(progress_arg, GOT_STATUS_DELETE, ie->path);
1311 		if (err)
1312 			return err;
1313 		if (status == GOT_STATUS_NO_CHANGE) {
1314 			err = remove_ondisk_file(worktree->root_path, ie->path);
1315 			if (err)
1316 				return err;
1317 		}
1318 		got_fileindex_entry_remove(fileindex, ie);
1319 	}
1320 
1321 	return err;
1322 }
1323 
1324 struct diff_cb_arg {
1325     struct got_fileindex *fileindex;
1326     struct got_worktree *worktree;
1327     struct got_repository *repo;
1328     got_worktree_checkout_cb progress_cb;
1329     void *progress_arg;
1330     got_worktree_cancel_cb cancel_cb;
1331     void *cancel_arg;
1332 };
1333 
1334 static const struct got_error *
1335 diff_old_new(void *arg, struct got_fileindex_entry *ie,
1336     struct got_tree_entry *te, const char *parent_path)
1337 {
1338 	struct diff_cb_arg *a = arg;
1339 
1340 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1341 		return got_error(GOT_ERR_CANCELLED);
1342 
1343 	return update_blob(a->worktree, a->fileindex, ie, te,
1344 	    ie->path, a->repo, a->progress_cb, a->progress_arg);
1345 }
1346 
1347 static const struct got_error *
1348 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1349 {
1350 	struct diff_cb_arg *a = arg;
1351 
1352 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1353 		return got_error(GOT_ERR_CANCELLED);
1354 
1355 	return delete_blob(a->worktree, a->fileindex, ie,
1356 	    a->repo, a->progress_cb, a->progress_arg);
1357 }
1358 
1359 static const struct got_error *
1360 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
1361 {
1362 	struct diff_cb_arg *a = arg;
1363 	const struct got_error *err;
1364 	char *path;
1365 
1366 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1367 		return got_error(GOT_ERR_CANCELLED);
1368 
1369 	if (asprintf(&path, "%s%s%s", parent_path,
1370 	    parent_path[0] ? "/" : "", te->name)
1371 	    == -1)
1372 		return got_error_from_errno("asprintf");
1373 
1374 	if (S_ISDIR(te->mode))
1375 		err = add_dir_on_disk(a->worktree, path);
1376 	else
1377 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
1378 		    a->repo, a->progress_cb, a->progress_arg);
1379 
1380 	free(path);
1381 	return err;
1382 }
1383 
1384 static const struct got_error *
1385 get_ref_name(char **refname, struct got_worktree *worktree, const char *prefix)
1386 {
1387 	const struct got_error *err = NULL;
1388 	char *uuidstr = NULL;
1389 	uint32_t uuid_status;
1390 
1391 	*refname = NULL;
1392 
1393 	uuid_to_string(&worktree->uuid, &uuidstr, &uuid_status);
1394 	if (uuid_status != uuid_s_ok)
1395 		return got_error_uuid(uuid_status);
1396 
1397 	if (asprintf(refname, "%s-%s", prefix, uuidstr)
1398 	    == -1) {
1399 		err = got_error_from_errno("asprintf");
1400 		*refname = NULL;
1401 	}
1402 	free(uuidstr);
1403 	return err;
1404 }
1405 
1406 const struct got_error *
1407 got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
1408 {
1409 	return get_ref_name(refname, worktree, GOT_WORKTREE_BASE_REF_PREFIX);
1410 }
1411 
1412 static const struct got_error *
1413 get_rebase_tmp_ref_name(char **refname, struct got_worktree *worktree)
1414 {
1415 	return get_ref_name(refname, worktree,
1416 	    GOT_WORKTREE_REBASE_TMP_REF_PREFIX);
1417 }
1418 
1419 static const struct got_error *
1420 get_newbase_symref_name(char **refname, struct got_worktree *worktree)
1421 {
1422 	return get_ref_name(refname, worktree, GOT_WORKTREE_NEWBASE_REF_PREFIX);
1423 }
1424 
1425 static const struct got_error *
1426 get_rebase_branch_symref_name(char **refname, struct got_worktree *worktree)
1427 {
1428 	return get_ref_name(refname, worktree,
1429 	    GOT_WORKTREE_REBASE_BRANCH_REF_PREFIX);
1430 }
1431 
1432 static const struct got_error *
1433 get_rebase_commit_ref_name(char **refname, struct got_worktree *worktree)
1434 {
1435 	return get_ref_name(refname, worktree,
1436 	    GOT_WORKTREE_REBASE_COMMIT_REF_PREFIX);
1437 }
1438 
1439 static const struct got_error *
1440 get_histedit_tmp_ref_name(char **refname, struct got_worktree *worktree)
1441 {
1442 	return get_ref_name(refname, worktree,
1443 	    GOT_WORKTREE_HISTEDIT_TMP_REF_PREFIX);
1444 }
1445 
1446 static const struct got_error *
1447 get_histedit_branch_symref_name(char **refname, struct got_worktree *worktree)
1448 {
1449 	return get_ref_name(refname, worktree,
1450 	    GOT_WORKTREE_HISTEDIT_BRANCH_REF_PREFIX);
1451 }
1452 
1453 static const struct got_error *
1454 get_histedit_base_commit_ref_name(char **refname, struct got_worktree *worktree)
1455 {
1456 	return get_ref_name(refname, worktree,
1457 	    GOT_WORKTREE_HISTEDIT_BASE_COMMIT_REF_PREFIX);
1458 }
1459 
1460 static const struct got_error *
1461 get_histedit_commit_ref_name(char **refname, struct got_worktree *worktree)
1462 {
1463 	return get_ref_name(refname, worktree,
1464 	    GOT_WORKTREE_HISTEDIT_COMMIT_REF_PREFIX);
1465 }
1466 
1467 const struct got_error *
1468 got_worktree_get_histedit_list_path(char **path, struct got_worktree *worktree)
1469 {
1470 	if (asprintf(path, "%s/%s/%s", worktree->root_path,
1471 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_HISTEDIT_LIST) == -1) {
1472 		*path = NULL;
1473 		return got_error_from_errno("asprintf");
1474 	}
1475 	return NULL;
1476 }
1477 
1478 /*
1479  * Prevent Git's garbage collector from deleting our base commit by
1480  * setting a reference to our base commit's ID.
1481  */
1482 static const struct got_error *
1483 ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
1484 {
1485 	const struct got_error *err = NULL;
1486 	struct got_reference *ref = NULL;
1487 	char *refname;
1488 
1489 	err = got_worktree_get_base_ref_name(&refname, worktree);
1490 	if (err)
1491 		return err;
1492 
1493 	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
1494 	if (err)
1495 		goto done;
1496 
1497 	err = got_ref_write(ref, repo);
1498 done:
1499 	free(refname);
1500 	if (ref)
1501 		got_ref_close(ref);
1502 	return err;
1503 }
1504 
1505 static const struct got_error *
1506 get_fileindex_path(char **fileindex_path, struct got_worktree *worktree)
1507 {
1508 	const struct got_error *err = NULL;
1509 
1510 	if (asprintf(fileindex_path, "%s/%s/%s", worktree->root_path,
1511 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1512 		err = got_error_from_errno("asprintf");
1513 		*fileindex_path = NULL;
1514 	}
1515 	return err;
1516 }
1517 
1518 
1519 static const struct got_error *
1520 open_fileindex(struct got_fileindex **fileindex, char **fileindex_path,
1521    struct got_worktree *worktree)
1522 {
1523 	const struct got_error *err = NULL;
1524 	FILE *index = NULL;
1525 
1526 	*fileindex_path = NULL;
1527 	*fileindex = got_fileindex_alloc();
1528 	if (*fileindex == NULL)
1529 		return got_error_from_errno("got_fileindex_alloc");
1530 
1531 	err = get_fileindex_path(fileindex_path, worktree);
1532 	if (err)
1533 		goto done;
1534 
1535 	index = fopen(*fileindex_path, "rb");
1536 	if (index == NULL) {
1537 		if (errno != ENOENT)
1538 			err = got_error_from_errno2("fopen", *fileindex_path);
1539 	} else {
1540 		err = got_fileindex_read(*fileindex, index);
1541 		if (fclose(index) != 0 && err == NULL)
1542 			err = got_error_from_errno("fclose");
1543 	}
1544 done:
1545 	if (err) {
1546 		free(*fileindex_path);
1547 		*fileindex_path = NULL;
1548 		got_fileindex_free(*fileindex);
1549 		*fileindex = NULL;
1550 	}
1551 	return err;
1552 }
1553 
1554 struct bump_base_commit_id_arg {
1555 	struct got_object_id *base_commit_id;
1556 	const char *path;
1557 	size_t path_len;
1558 	const char *entry_name;
1559 	got_worktree_checkout_cb progress_cb;
1560 	void *progress_arg;
1561 };
1562 
1563 /* Bump base commit ID of all files within an updated part of the work tree. */
1564 static const struct got_error *
1565 bump_base_commit_id(void *arg, struct got_fileindex_entry *ie)
1566 {
1567 	const struct got_error *err;
1568 	struct bump_base_commit_id_arg *a = arg;
1569 
1570 	if (a->entry_name) {
1571 		if (strcmp(ie->path, a->path) != 0)
1572 			return NULL;
1573 	} else if (!got_path_is_child(ie->path, a->path, a->path_len))
1574 		return NULL;
1575 
1576 	if (memcmp(ie->commit_sha1, a->base_commit_id->sha1,
1577 	    SHA1_DIGEST_LENGTH) == 0)
1578 		return NULL;
1579 
1580 	if (a->progress_cb) {
1581 		err = (*a->progress_cb)(a->progress_arg, GOT_STATUS_BUMP_BASE,
1582 		    ie->path);
1583 		if (err)
1584 			return err;
1585 	}
1586 	memcpy(ie->commit_sha1, a->base_commit_id->sha1, SHA1_DIGEST_LENGTH);
1587 	return NULL;
1588 }
1589 
1590 static const struct got_error *
1591 sync_fileindex(struct got_fileindex *fileindex, const char *fileindex_path)
1592 {
1593 	const struct got_error *err = NULL;
1594 	char *new_fileindex_path = NULL;
1595 	FILE *new_index = NULL;
1596 
1597 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1598 	    fileindex_path);
1599 	if (err)
1600 		goto done;
1601 
1602 	err = got_fileindex_write(fileindex, new_index);
1603 	if (err)
1604 		goto done;
1605 
1606 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1607 		err = got_error_from_errno3("rename", new_fileindex_path,
1608 		    fileindex_path);
1609 		unlink(new_fileindex_path);
1610 	}
1611 done:
1612 	if (new_index)
1613 		fclose(new_index);
1614 	free(new_fileindex_path);
1615 	return err;
1616 }
1617 
1618 static const struct got_error *
1619 find_tree_entry_for_checkout(int *entry_type, char **tree_relpath,
1620     struct got_object_id **tree_id, const char *wt_relpath,
1621     struct got_worktree *worktree, struct got_repository *repo)
1622 {
1623 	const struct got_error *err = NULL;
1624 	struct got_object_id *id = NULL;
1625 	char *in_repo_path = NULL;
1626 	int is_root_wt = got_path_is_root_dir(worktree->path_prefix);
1627 
1628 	*entry_type = GOT_OBJ_TYPE_ANY;
1629 	*tree_relpath = NULL;
1630 	*tree_id = NULL;
1631 
1632 	if (wt_relpath[0] == '\0') {
1633 		/* Check out all files within the work tree. */
1634 		*entry_type = GOT_OBJ_TYPE_TREE;
1635 		*tree_relpath = strdup("");
1636 		if (*tree_relpath == NULL) {
1637 			err = got_error_from_errno("strdup");
1638 			goto done;
1639 		}
1640 		err = got_object_id_by_path(tree_id, repo,
1641 		    worktree->base_commit_id, worktree->path_prefix);
1642 		if (err)
1643 			goto done;
1644 		return NULL;
1645 	}
1646 
1647 	/* Check out a subset of files in the work tree. */
1648 
1649 	if (asprintf(&in_repo_path, "%s%s%s", worktree->path_prefix,
1650 	    is_root_wt ? "" : "/", wt_relpath) == -1) {
1651 		err = got_error_from_errno("asprintf");
1652 		goto done;
1653 	}
1654 
1655 	err = got_object_id_by_path(&id, repo, worktree->base_commit_id,
1656 	    in_repo_path);
1657 	if (err)
1658 		goto done;
1659 
1660 	free(in_repo_path);
1661 	in_repo_path = NULL;
1662 
1663 	err = got_object_get_type(entry_type, repo, id);
1664 	if (err)
1665 		goto done;
1666 
1667 	if (*entry_type == GOT_OBJ_TYPE_BLOB) {
1668 		/* Check out a single file. */
1669 		if (strchr(wt_relpath, '/')  == NULL) {
1670 			/* Check out a single file in work tree's root dir. */
1671 			in_repo_path = strdup(worktree->path_prefix);
1672 			if (in_repo_path == NULL) {
1673 				err = got_error_from_errno("strdup");
1674 				goto done;
1675 			}
1676 			*tree_relpath = strdup("");
1677 			if (*tree_relpath == NULL) {
1678 				err = got_error_from_errno("strdup");
1679 				goto done;
1680 			}
1681 		} else {
1682 			/* Check out a single file in a subdirectory. */
1683 			err = got_path_dirname(tree_relpath, wt_relpath);
1684 			if (err)
1685 				return err;
1686 			if (asprintf(&in_repo_path, "%s%s%s",
1687 			    worktree->path_prefix, is_root_wt ? "" : "/",
1688 			    *tree_relpath) == -1) {
1689 				err = got_error_from_errno("asprintf");
1690 				goto done;
1691 			}
1692 		}
1693 		err = got_object_id_by_path(tree_id, repo,
1694 		    worktree->base_commit_id, in_repo_path);
1695 	} else {
1696 		/* Check out all files within a subdirectory. */
1697 		*tree_id = got_object_id_dup(id);
1698 		if (*tree_id == NULL) {
1699 			err = got_error_from_errno("got_object_id_dup");
1700 			goto done;
1701 		}
1702 		*tree_relpath = strdup(wt_relpath);
1703 		if (*tree_relpath == NULL) {
1704 			err = got_error_from_errno("strdup");
1705 			goto done;
1706 		}
1707 	}
1708 done:
1709 	free(id);
1710 	free(in_repo_path);
1711 	if (err) {
1712 		*entry_type = GOT_OBJ_TYPE_ANY;
1713 		free(*tree_relpath);
1714 		*tree_relpath = NULL;
1715 		free(*tree_id);
1716 		*tree_id = NULL;
1717 	}
1718 	return err;
1719 }
1720 
1721 static const struct got_error *
1722 checkout_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
1723     const char *relpath, struct got_object_id *tree_id, const char *entry_name,
1724     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1725     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1726 {
1727 	const struct got_error *err = NULL;
1728 	struct got_commit_object *commit = NULL;
1729 	struct got_tree_object *tree = NULL;
1730 	struct got_fileindex_diff_tree_cb diff_cb;
1731 	struct diff_cb_arg arg;
1732 
1733 	err = ref_base_commit(worktree, repo);
1734 	if (err)
1735 		goto done;
1736 
1737 	err = got_object_open_as_commit(&commit, repo,
1738 	   worktree->base_commit_id);
1739 	if (err)
1740 		goto done;
1741 
1742 	err = got_object_open_as_tree(&tree, repo, tree_id);
1743 	if (err)
1744 		goto done;
1745 
1746 	if (entry_name &&
1747 	    got_object_tree_find_entry(tree, entry_name) == NULL) {
1748 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
1749 		goto done;
1750 	}
1751 
1752 	diff_cb.diff_old_new = diff_old_new;
1753 	diff_cb.diff_old = diff_old;
1754 	diff_cb.diff_new = diff_new;
1755 	arg.fileindex = fileindex;
1756 	arg.worktree = worktree;
1757 	arg.repo = repo;
1758 	arg.progress_cb = progress_cb;
1759 	arg.progress_arg = progress_arg;
1760 	arg.cancel_cb = cancel_cb;
1761 	arg.cancel_arg = cancel_arg;
1762 	err = got_fileindex_diff_tree(fileindex, tree, relpath,
1763 	    entry_name, repo, &diff_cb, &arg);
1764 done:
1765 	if (tree)
1766 		got_object_tree_close(tree);
1767 	if (commit)
1768 		got_object_commit_close(commit);
1769 	return err;
1770 }
1771 
1772 const struct got_error *
1773 got_worktree_checkout_files(struct got_worktree *worktree,
1774     struct got_pathlist_head *paths, struct got_repository *repo,
1775     got_worktree_checkout_cb progress_cb, void *progress_arg,
1776     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1777 {
1778 	const struct got_error *err = NULL, *sync_err, *unlockerr;
1779 	struct got_commit_object *commit = NULL;
1780 	struct got_tree_object *tree = NULL;
1781 	struct got_fileindex *fileindex = NULL;
1782 	char *fileindex_path = NULL;
1783 	struct got_pathlist_entry *pe;
1784 	struct tree_path_data {
1785 		SIMPLEQ_ENTRY(tree_path_data) entry;
1786 		struct got_object_id *tree_id;
1787 		int entry_type;
1788 		char *relpath;
1789 		char *entry_name;
1790 	} *tpd = NULL;
1791 	SIMPLEQ_HEAD(tree_paths, tree_path_data) tree_paths;
1792 
1793 	SIMPLEQ_INIT(&tree_paths);
1794 
1795 	err = lock_worktree(worktree, LOCK_EX);
1796 	if (err)
1797 		return err;
1798 
1799 	/* Map all specified paths to in-repository trees. */
1800 	TAILQ_FOREACH(pe, paths, entry) {
1801 		tpd = malloc(sizeof(*tpd));
1802 		if (tpd == NULL) {
1803 			err = got_error_from_errno("malloc");
1804 			goto done;
1805 		}
1806 
1807 		err = find_tree_entry_for_checkout(&tpd->entry_type,
1808 		    &tpd->relpath, &tpd->tree_id, pe->path, worktree, repo);
1809 		if (err) {
1810 			free(tpd);
1811 			goto done;
1812 		}
1813 
1814 		if (tpd->entry_type == GOT_OBJ_TYPE_BLOB) {
1815 			err = got_path_basename(&tpd->entry_name, pe->path);
1816 			if (err) {
1817 				free(tpd->relpath);
1818 				free(tpd->tree_id);
1819 				free(tpd);
1820 				goto done;
1821 			}
1822 		} else
1823 			tpd->entry_name = NULL;
1824 
1825 		SIMPLEQ_INSERT_TAIL(&tree_paths, tpd, entry);
1826 	}
1827 
1828 	/*
1829 	 * Read the file index.
1830 	 * Checking out files is supposed to be an idempotent operation.
1831 	 * If the on-disk file index is incomplete we will try to complete it.
1832 	 */
1833 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1834 	if (err)
1835 		goto done;
1836 
1837 	tpd = SIMPLEQ_FIRST(&tree_paths);
1838 	TAILQ_FOREACH(pe, paths, entry) {
1839 		struct bump_base_commit_id_arg bbc_arg;
1840 
1841 		err = checkout_files(worktree, fileindex, tpd->relpath,
1842 		    tpd->tree_id, tpd->entry_name, repo,
1843 		    progress_cb, progress_arg, cancel_cb, cancel_arg);
1844 		if (err)
1845 			break;
1846 
1847 		bbc_arg.base_commit_id = worktree->base_commit_id;
1848 		bbc_arg.entry_name = tpd->entry_name;
1849 		bbc_arg.path = pe->path;
1850 		bbc_arg.path_len = strlen(pe->path);
1851 		bbc_arg.progress_cb = progress_cb;
1852 		bbc_arg.progress_arg = progress_arg;
1853 		err = got_fileindex_for_each_entry_safe(fileindex,
1854 		    bump_base_commit_id, &bbc_arg);
1855 		if (err)
1856 			break;
1857 
1858 		tpd = SIMPLEQ_NEXT(tpd, entry);
1859 	}
1860 	sync_err = sync_fileindex(fileindex, fileindex_path);
1861 	if (sync_err && err == NULL)
1862 		err = sync_err;
1863 done:
1864 	free(fileindex_path);
1865 	if (tree)
1866 		got_object_tree_close(tree);
1867 	if (commit)
1868 		got_object_commit_close(commit);
1869 	if (fileindex)
1870 		got_fileindex_free(fileindex);
1871 	while (!SIMPLEQ_EMPTY(&tree_paths)) {
1872 		tpd = SIMPLEQ_FIRST(&tree_paths);
1873 		SIMPLEQ_REMOVE_HEAD(&tree_paths, entry);
1874 		free(tpd->relpath);
1875 		free(tpd->tree_id);
1876 		free(tpd);
1877 	}
1878 	unlockerr = lock_worktree(worktree, LOCK_SH);
1879 	if (unlockerr && err == NULL)
1880 		err = unlockerr;
1881 	return err;
1882 }
1883 
1884 struct merge_file_cb_arg {
1885     struct got_worktree *worktree;
1886     struct got_fileindex *fileindex;
1887     got_worktree_checkout_cb progress_cb;
1888     void *progress_arg;
1889     got_worktree_cancel_cb cancel_cb;
1890     void *cancel_arg;
1891     struct got_object_id *commit_id2;
1892 };
1893 
1894 static const struct got_error *
1895 merge_file_cb(void *arg, struct got_blob_object *blob1,
1896     struct got_blob_object *blob2, struct got_object_id *id1,
1897     struct got_object_id *id2, const char *path1, const char *path2,
1898     struct got_repository *repo)
1899 {
1900 	static const struct got_error *err = NULL;
1901 	struct merge_file_cb_arg *a = arg;
1902 	struct got_fileindex_entry *ie;
1903 	char *ondisk_path = NULL;
1904 	struct stat sb;
1905 	unsigned char status;
1906 	int local_changes_subsumed;
1907 
1908 	if (blob1 && blob2) {
1909 		ie = got_fileindex_entry_get(a->fileindex, path2);
1910 		if (ie == NULL)
1911 			return (*a->progress_cb)(a->progress_arg,
1912 			    GOT_STATUS_MISSING, path2);
1913 
1914 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1915 		    path2) == -1)
1916 			return got_error_from_errno("asprintf");
1917 
1918 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1919 		if (err)
1920 			goto done;
1921 
1922 		if (status == GOT_STATUS_DELETE) {
1923 			err = (*a->progress_cb)(a->progress_arg,
1924 			    GOT_STATUS_MERGE, path2);
1925 			goto done;
1926 		}
1927 		if (status != GOT_STATUS_NO_CHANGE &&
1928 		    status != GOT_STATUS_MODIFY &&
1929 		    status != GOT_STATUS_CONFLICT &&
1930 		    status != GOT_STATUS_ADD) {
1931 			err = (*a->progress_cb)(a->progress_arg, status, path2);
1932 			goto done;
1933 		}
1934 
1935 		err = merge_blob(&local_changes_subsumed, a->worktree, blob1,
1936 		    ondisk_path, path2, sb.st_mode, blob2, a->commit_id2, repo,
1937 		    a->progress_cb, a->progress_arg);
1938 	} else if (blob1) {
1939 		ie = got_fileindex_entry_get(a->fileindex, path1);
1940 		if (ie == NULL)
1941 			return (*a->progress_cb)(a->progress_arg,
1942 			    GOT_STATUS_MISSING, path2);
1943 
1944 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1945 		    path1) == -1)
1946 			return got_error_from_errno("asprintf");
1947 
1948 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1949 		if (err)
1950 			goto done;
1951 
1952 		switch (status) {
1953 		case GOT_STATUS_NO_CHANGE:
1954 			err = (*a->progress_cb)(a->progress_arg,
1955 			    GOT_STATUS_DELETE, path1);
1956 			if (err)
1957 				goto done;
1958 			err = remove_ondisk_file(a->worktree->root_path, path1);
1959 			if (err)
1960 				goto done;
1961 			if (ie)
1962 				got_fileindex_entry_mark_deleted_from_disk(ie);
1963 			break;
1964 		case GOT_STATUS_DELETE:
1965 		case GOT_STATUS_MISSING:
1966 			err = (*a->progress_cb)(a->progress_arg,
1967 			    GOT_STATUS_DELETE, path1);
1968 			if (err)
1969 				goto done;
1970 			if (ie)
1971 				got_fileindex_entry_mark_deleted_from_disk(ie);
1972 			break;
1973 		case GOT_STATUS_ADD:
1974 		case GOT_STATUS_MODIFY:
1975 		case GOT_STATUS_CONFLICT:
1976 			err = (*a->progress_cb)(a->progress_arg,
1977 			    GOT_STATUS_CANNOT_DELETE, path1);
1978 			if (err)
1979 				goto done;
1980 			break;
1981 		case GOT_STATUS_OBSTRUCTED:
1982 			err = (*a->progress_cb)(a->progress_arg, status, path1);
1983 			if (err)
1984 				goto done;
1985 			break;
1986 		default:
1987 			break;
1988 		}
1989 	} else if (blob2) {
1990 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1991 		    path2) == -1)
1992 			return got_error_from_errno("asprintf");
1993 		ie = got_fileindex_entry_get(a->fileindex, path2);
1994 		if (ie) {
1995 			err = get_file_status(&status, &sb, ie, ondisk_path,
1996 			    repo);
1997 			if (err)
1998 				goto done;
1999 			if (status != GOT_STATUS_NO_CHANGE &&
2000 			    status != GOT_STATUS_MODIFY &&
2001 			    status != GOT_STATUS_CONFLICT &&
2002 			    status != GOT_STATUS_ADD) {
2003 				err = (*a->progress_cb)(a->progress_arg,
2004 				    status, path2);
2005 				goto done;
2006 			}
2007 			err = merge_blob(&local_changes_subsumed, a->worktree,
2008 			    NULL, ondisk_path, path2, sb.st_mode, blob2,
2009 			    a->commit_id2, repo,
2010 			    a->progress_cb, a->progress_arg);
2011 			if (status == GOT_STATUS_DELETE) {
2012 				err = update_blob_fileindex_entry(a->worktree,
2013 				    a->fileindex, ie, ondisk_path, ie->path,
2014 				    blob2, 0);
2015 				if (err)
2016 					goto done;
2017 			}
2018 		} else {
2019 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
2020 			err = install_blob(a->worktree, ondisk_path, path2,
2021 			    /* XXX get this from parent tree! */
2022 			    GOT_DEFAULT_FILE_MODE,
2023 			    sb.st_mode, blob2, 0, 0, repo,
2024 			    a->progress_cb, a->progress_arg);
2025 			if (err)
2026 				goto done;
2027 			err = got_fileindex_entry_alloc(&ie,
2028 			    ondisk_path, path2, NULL, NULL);
2029 			if (err)
2030 				goto done;
2031 			err = got_fileindex_entry_add(a->fileindex, ie);
2032 			if (err) {
2033 				got_fileindex_entry_free(ie);
2034 				goto done;
2035 			}
2036 		}
2037 	}
2038 done:
2039 	free(ondisk_path);
2040 	return err;
2041 }
2042 
2043 struct check_merge_ok_arg {
2044 	struct got_worktree *worktree;
2045 	struct got_repository *repo;
2046 };
2047 
2048 static const struct got_error *
2049 check_merge_ok(void *arg, struct got_fileindex_entry *ie)
2050 {
2051 	const struct got_error *err = NULL;
2052 	struct check_merge_ok_arg *a = arg;
2053 	unsigned char status;
2054 	struct stat sb;
2055 	char *ondisk_path;
2056 
2057 	/* Reject merges into a work tree with mixed base commits. */
2058 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
2059 	    SHA1_DIGEST_LENGTH))
2060 		return got_error(GOT_ERR_MIXED_COMMITS);
2061 
2062 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
2063 	    == -1)
2064 		return got_error_from_errno("asprintf");
2065 
2066 	/* Reject merges into a work tree with conflicted files. */
2067 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
2068 	if (err)
2069 		return err;
2070 	if (status == GOT_STATUS_CONFLICT)
2071 		return got_error(GOT_ERR_CONFLICTS);
2072 
2073 	return NULL;
2074 }
2075 
2076 static const struct got_error *
2077 merge_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
2078     const char *fileindex_path, struct got_object_id *commit_id1,
2079     struct got_object_id *commit_id2, struct got_repository *repo,
2080     got_worktree_checkout_cb progress_cb, void *progress_arg,
2081     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2082 {
2083 	const struct got_error *err = NULL, *sync_err;
2084 	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
2085 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
2086 	struct merge_file_cb_arg arg;
2087 
2088 	if (commit_id1) {
2089 		err = got_object_id_by_path(&tree_id1, repo, commit_id1,
2090 		    worktree->path_prefix);
2091 		if (err)
2092 			goto done;
2093 
2094 		err = got_object_open_as_tree(&tree1, repo, tree_id1);
2095 		if (err)
2096 			goto done;
2097 	}
2098 
2099 	err = got_object_id_by_path(&tree_id2, repo, commit_id2,
2100 	    worktree->path_prefix);
2101 	if (err)
2102 		goto done;
2103 
2104 	err = got_object_open_as_tree(&tree2, repo, tree_id2);
2105 	if (err)
2106 		goto done;
2107 
2108 	arg.worktree = worktree;
2109 	arg.fileindex = fileindex;
2110 	arg.progress_cb = progress_cb;
2111 	arg.progress_arg = progress_arg;
2112 	arg.cancel_cb = cancel_cb;
2113 	arg.cancel_arg = cancel_arg;
2114 	arg.commit_id2 = commit_id2;
2115 	err = got_diff_tree(tree1, tree2, "", "", repo, merge_file_cb, &arg, 1);
2116 	sync_err = sync_fileindex(fileindex, fileindex_path);
2117 	if (sync_err && err == NULL)
2118 		err = sync_err;
2119 done:
2120 	if (tree1)
2121 		got_object_tree_close(tree1);
2122 	if (tree2)
2123 		got_object_tree_close(tree2);
2124 	return err;
2125 }
2126 
2127 const struct got_error *
2128 got_worktree_merge_files(struct got_worktree *worktree,
2129     struct got_object_id *commit_id1, struct got_object_id *commit_id2,
2130     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
2131     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2132 {
2133 	const struct got_error *err, *unlockerr;
2134 	char *fileindex_path = NULL;
2135 	struct got_fileindex *fileindex = NULL;
2136 	struct check_merge_ok_arg mok_arg;
2137 
2138 	err = lock_worktree(worktree, LOCK_EX);
2139 	if (err)
2140 		return err;
2141 
2142 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2143 	if (err)
2144 		goto done;
2145 
2146 	mok_arg.worktree = worktree;
2147 	mok_arg.repo = repo;
2148 	err = got_fileindex_for_each_entry_safe(fileindex, check_merge_ok,
2149 	    &mok_arg);
2150 	if (err)
2151 		goto done;
2152 
2153 	err = merge_files(worktree, fileindex, fileindex_path, commit_id1,
2154 	    commit_id2, repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
2155 done:
2156 	if (fileindex)
2157 		got_fileindex_free(fileindex);
2158 	free(fileindex_path);
2159 	unlockerr = lock_worktree(worktree, LOCK_SH);
2160 	if (unlockerr && err == NULL)
2161 		err = unlockerr;
2162 	return err;
2163 }
2164 
2165 struct diff_dir_cb_arg {
2166     struct got_fileindex *fileindex;
2167     struct got_worktree *worktree;
2168     const char *status_path;
2169     size_t status_path_len;
2170     struct got_repository *repo;
2171     got_worktree_status_cb status_cb;
2172     void *status_arg;
2173     got_worktree_cancel_cb cancel_cb;
2174     void *cancel_arg;
2175 };
2176 
2177 static const struct got_error *
2178 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
2179     got_worktree_status_cb status_cb, void *status_arg,
2180     struct got_repository *repo)
2181 {
2182 	const struct got_error *err = NULL;
2183 	unsigned char status = GOT_STATUS_NO_CHANGE;
2184 	struct stat sb;
2185 	struct got_object_id blob_id, commit_id;
2186 
2187 	err = get_file_status(&status, &sb, ie, abspath, repo);
2188 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
2189 		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2190 		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2191 		err = (*status_cb)(status_arg, status, ie->path, &blob_id,
2192 		    &commit_id);
2193 	}
2194 	return err;
2195 }
2196 
2197 static const struct got_error *
2198 status_old_new(void *arg, struct got_fileindex_entry *ie,
2199     struct dirent *de, const char *parent_path)
2200 {
2201 	const struct got_error *err = NULL;
2202 	struct diff_dir_cb_arg *a = arg;
2203 	char *abspath;
2204 
2205 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2206 		return got_error(GOT_ERR_CANCELLED);
2207 
2208 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
2209 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
2210 		return NULL;
2211 
2212 	if (parent_path[0]) {
2213 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
2214 		    parent_path, de->d_name) == -1)
2215 			return got_error_from_errno("asprintf");
2216 	} else {
2217 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
2218 		    de->d_name) == -1)
2219 			return got_error_from_errno("asprintf");
2220 	}
2221 
2222 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
2223 	    a->repo);
2224 	free(abspath);
2225 	return err;
2226 }
2227 
2228 static const struct got_error *
2229 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
2230 {
2231 	struct diff_dir_cb_arg *a = arg;
2232 	struct got_object_id blob_id, commit_id;
2233 	unsigned char status;
2234 
2235 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2236 		return got_error(GOT_ERR_CANCELLED);
2237 
2238 	if (!got_path_is_child(ie->path, a->status_path, a->status_path_len))
2239 		return NULL;
2240 
2241 	memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2242 	memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2243 	if (got_fileindex_entry_has_file_on_disk(ie))
2244 		status = GOT_STATUS_MISSING;
2245 	else
2246 		status = GOT_STATUS_DELETE;
2247 	return (*a->status_cb)(a->status_arg, status, ie->path, &blob_id,
2248 	    &commit_id);
2249 }
2250 
2251 static const struct got_error *
2252 status_new(void *arg, struct dirent *de, const char *parent_path)
2253 {
2254 	const struct got_error *err = NULL;
2255 	struct diff_dir_cb_arg *a = arg;
2256 	char *path = NULL;
2257 
2258 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2259 		return got_error(GOT_ERR_CANCELLED);
2260 
2261 	if (de->d_type == DT_DIR)
2262 		return NULL;
2263 
2264 	/* XXX ignore symlinks for now */
2265 	if (de->d_type == DT_LNK)
2266 		return NULL;
2267 
2268 	if (parent_path[0]) {
2269 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
2270 			return got_error_from_errno("asprintf");
2271 	} else {
2272 		path = de->d_name;
2273 	}
2274 
2275 	if (got_path_is_child(path, a->status_path, a->status_path_len))
2276 		err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED,
2277 		    path, NULL, NULL);
2278 	if (parent_path[0])
2279 		free(path);
2280 	return err;
2281 }
2282 
2283 static const struct got_error *
2284 report_single_file_status(const char *path, const char *ondisk_path,
2285 struct got_fileindex *fileindex, got_worktree_status_cb status_cb,
2286 void *status_arg, struct got_repository *repo)
2287 {
2288 	struct got_fileindex_entry *ie;
2289 	struct stat sb;
2290 
2291 	ie = got_fileindex_entry_get(fileindex, path);
2292 	if (ie)
2293 		return report_file_status(ie, ondisk_path, status_cb,
2294 		    status_arg, repo);
2295 
2296 	if (lstat(ondisk_path, &sb) == -1) {
2297 		if (errno != ENOENT)
2298 			return got_error_from_errno2("lstat", ondisk_path);
2299 		return NULL;
2300 	}
2301 
2302 	if (S_ISREG(sb.st_mode))
2303 		return (*status_cb)(status_arg, GOT_STATUS_UNVERSIONED, path,
2304 		    NULL, NULL);
2305 
2306 	return NULL;
2307 }
2308 
2309 static const struct got_error *
2310 worktree_status(struct got_worktree *worktree, const char *path,
2311     struct got_fileindex *fileindex, struct got_repository *repo,
2312     got_worktree_status_cb status_cb, void *status_arg,
2313     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2314 {
2315 	const struct got_error *err = NULL;
2316 	DIR *workdir = NULL;
2317 	struct got_fileindex_diff_dir_cb fdiff_cb;
2318 	struct diff_dir_cb_arg arg;
2319 	char *ondisk_path = NULL;
2320 
2321 	if (asprintf(&ondisk_path, "%s%s%s",
2322 	    worktree->root_path, path[0] ? "/" : "", path) == -1)
2323 		return got_error_from_errno("asprintf");
2324 
2325 	workdir = opendir(ondisk_path);
2326 	if (workdir == NULL) {
2327 		if (errno != ENOTDIR && errno != ENOENT)
2328 			err = got_error_from_errno2("opendir", ondisk_path);
2329 		else
2330 			err = report_single_file_status(path, ondisk_path,
2331 			    fileindex, status_cb, status_arg, repo);
2332 	} else {
2333 		fdiff_cb.diff_old_new = status_old_new;
2334 		fdiff_cb.diff_old = status_old;
2335 		fdiff_cb.diff_new = status_new;
2336 		arg.fileindex = fileindex;
2337 		arg.worktree = worktree;
2338 		arg.status_path = path;
2339 		arg.status_path_len = strlen(path);
2340 		arg.repo = repo;
2341 		arg.status_cb = status_cb;
2342 		arg.status_arg = status_arg;
2343 		arg.cancel_cb = cancel_cb;
2344 		arg.cancel_arg = cancel_arg;
2345 		err = got_fileindex_diff_dir(fileindex, workdir,
2346 		    worktree->root_path, path, repo, &fdiff_cb, &arg);
2347 	}
2348 
2349 	if (workdir)
2350 		closedir(workdir);
2351 	free(ondisk_path);
2352 	return err;
2353 }
2354 
2355 const struct got_error *
2356 got_worktree_status(struct got_worktree *worktree,
2357     struct got_pathlist_head *paths, struct got_repository *repo,
2358     got_worktree_status_cb status_cb, void *status_arg,
2359     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2360 {
2361 	const struct got_error *err = NULL;
2362 	char *fileindex_path = NULL;
2363 	struct got_fileindex *fileindex = NULL;
2364 	struct got_pathlist_entry *pe;
2365 
2366 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2367 	if (err)
2368 		return err;
2369 
2370 	TAILQ_FOREACH(pe, paths, entry) {
2371 		err = worktree_status(worktree, pe->path, fileindex, repo,
2372 			status_cb, status_arg, cancel_cb, cancel_arg);
2373 		if (err)
2374 			break;
2375 	}
2376 	free(fileindex_path);
2377 	got_fileindex_free(fileindex);
2378 	return err;
2379 }
2380 
2381 const struct got_error *
2382 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
2383     const char *arg)
2384 {
2385 	const struct got_error *err = NULL;
2386 	char *resolved, *cwd = NULL, *path = NULL;
2387 	size_t len;
2388 
2389 	*wt_path = NULL;
2390 
2391 	resolved = realpath(arg, NULL);
2392 	if (resolved == NULL) {
2393 		if (errno != ENOENT)
2394 			return got_error_from_errno2("realpath", arg);
2395 		cwd = getcwd(NULL, 0);
2396 		if (cwd == NULL)
2397 			return got_error_from_errno("getcwd");
2398 		if (asprintf(&resolved, "%s/%s", cwd, arg) == -1) {
2399 			err = got_error_from_errno("asprintf");
2400 			goto done;
2401 		}
2402 	}
2403 
2404 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
2405 	    strlen(got_worktree_get_root_path(worktree)))) {
2406 		err = got_error(GOT_ERR_BAD_PATH);
2407 		goto done;
2408 	}
2409 
2410 	if (strlen(resolved) > strlen(got_worktree_get_root_path(worktree))) {
2411 		err = got_path_skip_common_ancestor(&path,
2412 		    got_worktree_get_root_path(worktree), resolved);
2413 		if (err)
2414 			goto done;
2415 	} else {
2416 		path = strdup("");
2417 		if (path == NULL) {
2418 			err = got_error_from_errno("strdup");
2419 			goto done;
2420 		}
2421 	}
2422 
2423 	/* XXX status walk can't deal with trailing slash! */
2424 	len = strlen(path);
2425 	while (len > 0 && path[len - 1] == '/') {
2426 		path[len - 1] = '\0';
2427 		len--;
2428 	}
2429 done:
2430 	free(resolved);
2431 	free(cwd);
2432 	if (err == NULL)
2433 		*wt_path = path;
2434 	else
2435 		free(path);
2436 	return err;
2437 }
2438 
2439 static const struct got_error *
2440 schedule_addition(const char *ondisk_path, struct got_fileindex *fileindex,
2441     const char *relpath, got_worktree_status_cb status_cb, void *status_arg,
2442     struct got_repository *repo)
2443 {
2444 	const struct got_error *err = NULL;
2445 	struct got_fileindex_entry *ie;
2446 
2447 	/* Re-adding an existing entry is a no-op. */
2448 	if (got_fileindex_entry_get(fileindex, relpath) != NULL)
2449 		return NULL;
2450 
2451 	err = got_fileindex_entry_alloc(&ie, ondisk_path, relpath, NULL, NULL);
2452 	if (err)
2453 		return err;
2454 
2455 	err = got_fileindex_entry_add(fileindex, ie);
2456 	if (err) {
2457 		got_fileindex_entry_free(ie);
2458 		return err;
2459 	}
2460 
2461 	return report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2462 }
2463 
2464 const struct got_error *
2465 got_worktree_schedule_add(struct got_worktree *worktree,
2466     struct got_pathlist_head *ondisk_paths,
2467     got_worktree_status_cb status_cb, void *status_arg,
2468     struct got_repository *repo)
2469 {
2470 	struct got_fileindex *fileindex = NULL;
2471 	char *fileindex_path = NULL;
2472 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2473 	struct got_pathlist_entry *pe;
2474 
2475 	err = lock_worktree(worktree, LOCK_EX);
2476 	if (err)
2477 		return err;
2478 
2479 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2480 	if (err)
2481 		goto done;
2482 
2483 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2484 		char *relpath;
2485 		err = got_path_skip_common_ancestor(&relpath,
2486 		    got_worktree_get_root_path(worktree), pe->path);
2487 		if (err)
2488 			break;
2489 		err = schedule_addition(pe->path, fileindex, relpath,
2490 		    status_cb, status_arg, repo);
2491 		free(relpath);
2492 		if (err)
2493 			break;
2494 	}
2495 	sync_err = sync_fileindex(fileindex, fileindex_path);
2496 	if (sync_err && err == NULL)
2497 		err = sync_err;
2498 done:
2499 	free(fileindex_path);
2500 	if (fileindex)
2501 		got_fileindex_free(fileindex);
2502 	unlockerr = lock_worktree(worktree, LOCK_SH);
2503 	if (unlockerr && err == NULL)
2504 		err = unlockerr;
2505 	return err;
2506 }
2507 
2508 static const struct got_error *
2509 schedule_for_deletion(const char *ondisk_path, struct got_fileindex *fileindex,
2510     const char *relpath, int delete_local_mods,
2511     got_worktree_status_cb status_cb, void *status_arg,
2512     struct got_repository *repo)
2513 {
2514 	const struct got_error *err = NULL;
2515 	struct got_fileindex_entry *ie = NULL;
2516 	unsigned char status;
2517 	struct stat sb;
2518 
2519 	ie = got_fileindex_entry_get(fileindex, relpath);
2520 	if (ie == NULL)
2521 		return got_error(GOT_ERR_BAD_PATH);
2522 
2523 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2524 	if (err)
2525 		return err;
2526 
2527 	if (status != GOT_STATUS_NO_CHANGE) {
2528 		if (status == GOT_STATUS_DELETE)
2529 			return got_error_set_errno(ENOENT, ondisk_path);
2530 		if (status != GOT_STATUS_MODIFY)
2531 			return got_error(GOT_ERR_FILE_STATUS);
2532 		if (!delete_local_mods)
2533 			return got_error(GOT_ERR_FILE_MODIFIED);
2534 	}
2535 
2536 	if (unlink(ondisk_path) != 0)
2537 		return got_error_from_errno2("unlink", ondisk_path);
2538 
2539 	got_fileindex_entry_mark_deleted_from_disk(ie);
2540 	return report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2541 }
2542 
2543 const struct got_error *
2544 got_worktree_schedule_delete(struct got_worktree *worktree,
2545     struct got_pathlist_head *ondisk_paths, int delete_local_mods,
2546     got_worktree_status_cb status_cb, void *status_arg,
2547     struct got_repository *repo)
2548 {
2549 	struct got_fileindex *fileindex = NULL;
2550 	char *fileindex_path = NULL;
2551 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2552 	struct got_pathlist_entry *pe;
2553 
2554 	err = lock_worktree(worktree, LOCK_EX);
2555 	if (err)
2556 		return err;
2557 
2558 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2559 	if (err)
2560 		goto done;
2561 
2562 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2563 		char *relpath;
2564 		err = got_path_skip_common_ancestor(&relpath,
2565 		    got_worktree_get_root_path(worktree), pe->path);
2566 		if (err)
2567 			break;
2568 		err = schedule_for_deletion(pe->path, fileindex, relpath,
2569 		    delete_local_mods, status_cb, status_arg, repo);
2570 		free(relpath);
2571 		if (err)
2572 			break;
2573 	}
2574 	sync_err = sync_fileindex(fileindex, fileindex_path);
2575 	if (sync_err && err == NULL)
2576 		err = sync_err;
2577 done:
2578 	free(fileindex_path);
2579 	if (fileindex)
2580 		got_fileindex_free(fileindex);
2581 	unlockerr = lock_worktree(worktree, LOCK_SH);
2582 	if (unlockerr && err == NULL)
2583 		err = unlockerr;
2584 	return err;
2585 }
2586 
2587 static const struct got_error *
2588 revert_file(struct got_worktree *worktree, struct got_fileindex *fileindex,
2589     const char *ondisk_path,
2590     got_worktree_checkout_cb progress_cb, void *progress_arg,
2591     struct got_repository *repo)
2592 {
2593 	const struct got_error *err = NULL;
2594 	char *relpath = NULL, *parent_path = NULL;
2595 	struct got_fileindex_entry *ie;
2596 	struct got_tree_object *tree = NULL;
2597 	struct got_object_id *tree_id = NULL;
2598 	const struct got_tree_entry *te;
2599 	char *tree_path = NULL, *te_name;
2600 	struct got_blob_object *blob = NULL;
2601 	unsigned char status;
2602 	struct stat sb;
2603 
2604 	err = got_path_skip_common_ancestor(&relpath,
2605 	    got_worktree_get_root_path(worktree), ondisk_path);
2606 	if (err)
2607 		goto done;
2608 
2609 	ie = got_fileindex_entry_get(fileindex, relpath);
2610 	if (ie == NULL) {
2611 		err = got_error(GOT_ERR_BAD_PATH);
2612 		goto done;
2613 	}
2614 
2615 	/* Construct in-repository path of tree which contains this blob. */
2616 	err = got_path_dirname(&parent_path, ie->path);
2617 	if (err) {
2618 		if (err->code != GOT_ERR_BAD_PATH)
2619 			goto done;
2620 		parent_path = strdup("/");
2621 		if (parent_path == NULL) {
2622 			err = got_error_from_errno("strdup");
2623 			goto done;
2624 		}
2625 	}
2626 	if (got_path_is_root_dir(worktree->path_prefix)) {
2627 		tree_path = strdup(parent_path);
2628 		if (tree_path == NULL) {
2629 			err = got_error_from_errno("strdup");
2630 			goto done;
2631 		}
2632 	} else {
2633 		if (got_path_is_root_dir(parent_path)) {
2634 			tree_path = strdup(worktree->path_prefix);
2635 			if (tree_path == NULL) {
2636 				err = got_error_from_errno("strdup");
2637 				goto done;
2638 			}
2639 		} else {
2640 			if (asprintf(&tree_path, "%s/%s",
2641 			    worktree->path_prefix, parent_path) == -1) {
2642 				err = got_error_from_errno("asprintf");
2643 				goto done;
2644 			}
2645 		}
2646 	}
2647 
2648 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2649 	if (err)
2650 		goto done;
2651 
2652 	err = got_object_id_by_path(&tree_id, repo, worktree->base_commit_id,
2653 	    tree_path);
2654 	if (err) {
2655 		if (!(err->code == GOT_ERR_NO_TREE_ENTRY &&
2656 		    status == GOT_STATUS_ADD))
2657 			goto done;
2658 	} else {
2659 		err = got_object_open_as_tree(&tree, repo, tree_id);
2660 		if (err)
2661 			goto done;
2662 
2663 		te_name = basename(ie->path);
2664 		if (te_name == NULL) {
2665 			err = got_error_from_errno2("basename", ie->path);
2666 			goto done;
2667 		}
2668 
2669 		te = got_object_tree_find_entry(tree, te_name);
2670 		if (te == NULL && status != GOT_STATUS_ADD) {
2671 			err = got_error(GOT_ERR_NO_TREE_ENTRY);
2672 			goto done;
2673 		}
2674 	}
2675 
2676 	switch (status) {
2677 	case GOT_STATUS_ADD:
2678 		err = (*progress_cb)(progress_arg, GOT_STATUS_REVERT, ie->path);
2679 		if (err)
2680 			goto done;
2681 		got_fileindex_entry_remove(fileindex, ie);
2682 		break;
2683 	case GOT_STATUS_DELETE:
2684 	case GOT_STATUS_MODIFY:
2685 	case GOT_STATUS_CONFLICT:
2686 	case GOT_STATUS_MISSING: {
2687 		struct got_object_id id;
2688 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2689 		err = got_object_open_as_blob(&blob, repo, &id, 8192);
2690 		if (err)
2691 			goto done;
2692 		err = install_blob(worktree, ondisk_path, ie->path,
2693 		    te->mode, sb.st_mode, blob, 0, 1, repo, progress_cb,
2694 		    progress_arg);
2695 		if (err)
2696 			goto done;
2697 		if (status == GOT_STATUS_DELETE) {
2698 			err = update_blob_fileindex_entry(worktree,
2699 			    fileindex, ie, ondisk_path, ie->path, blob, 1);
2700 			if (err)
2701 				goto done;
2702 		}
2703 		break;
2704 	}
2705 	default:
2706 			goto done;
2707 	}
2708 done:
2709 	free(relpath);
2710 	free(parent_path);
2711 	free(tree_path);
2712 	if (blob)
2713 		got_object_blob_close(blob);
2714 	if (tree)
2715 		got_object_tree_close(tree);
2716 	free(tree_id);
2717 	return err;
2718 }
2719 
2720 const struct got_error *
2721 got_worktree_revert(struct got_worktree *worktree,
2722     struct got_pathlist_head *ondisk_paths,
2723     got_worktree_checkout_cb progress_cb, void *progress_arg,
2724     struct got_repository *repo)
2725 {
2726 	struct got_fileindex *fileindex = NULL;
2727 	char *fileindex_path = NULL;
2728 	const struct got_error *err = NULL, *unlockerr = NULL;
2729 	const struct got_error *sync_err = NULL;
2730 	struct got_pathlist_entry *pe;
2731 
2732 	err = lock_worktree(worktree, LOCK_EX);
2733 	if (err)
2734 		return err;
2735 
2736 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2737 	if (err)
2738 		goto done;
2739 
2740 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2741 		err = revert_file(worktree, fileindex, pe->path,
2742 		    progress_cb, progress_arg, repo);
2743 		if (err)
2744 			break;
2745 	}
2746 	sync_err = sync_fileindex(fileindex, fileindex_path);
2747 	if (sync_err && err == NULL)
2748 		err = sync_err;
2749 done:
2750 	free(fileindex_path);
2751 	if (fileindex)
2752 		got_fileindex_free(fileindex);
2753 	unlockerr = lock_worktree(worktree, LOCK_SH);
2754 	if (unlockerr && err == NULL)
2755 		err = unlockerr;
2756 	return err;
2757 }
2758 
2759 static void
2760 free_commitable(struct got_commitable *ct)
2761 {
2762 	free(ct->path);
2763 	free(ct->in_repo_path);
2764 	free(ct->ondisk_path);
2765 	free(ct->blob_id);
2766 	free(ct->base_blob_id);
2767 	free(ct->base_commit_id);
2768 	free(ct);
2769 }
2770 
2771 struct collect_commitables_arg {
2772 	struct got_pathlist_head *commitable_paths;
2773 	struct got_repository *repo;
2774 	struct got_worktree *worktree;
2775 };
2776 
2777 static const struct got_error *
2778 collect_commitables(void *arg, unsigned char status, const char *relpath,
2779     struct got_object_id *blob_id, struct got_object_id *commit_id)
2780 {
2781 	struct collect_commitables_arg *a = arg;
2782 	const struct got_error *err = NULL;
2783 	struct got_commitable *ct = NULL;
2784 	struct got_pathlist_entry *new = NULL;
2785 	char *parent_path = NULL, *path = NULL;
2786 	struct stat sb;
2787 
2788 	if (status == GOT_STATUS_CONFLICT)
2789 		return got_error(GOT_ERR_COMMIT_CONFLICT);
2790 
2791 	if (status != GOT_STATUS_MODIFY && status != GOT_STATUS_ADD &&
2792 	    status != GOT_STATUS_DELETE)
2793 		return NULL;
2794 
2795 	if (asprintf(&path, "/%s", relpath) == -1) {
2796 		err = got_error_from_errno("asprintf");
2797 		goto done;
2798 	}
2799 	if (strcmp(path, "/") == 0) {
2800 		parent_path = strdup("");
2801 		if (parent_path == NULL)
2802 			return got_error_from_errno("strdup");
2803 	} else {
2804 		err = got_path_dirname(&parent_path, path);
2805 		if (err)
2806 			return err;
2807 	}
2808 
2809 	ct = calloc(1, sizeof(*ct));
2810 	if (ct == NULL) {
2811 		err = got_error_from_errno("calloc");
2812 		goto done;
2813 	}
2814 
2815 	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
2816 	    relpath) == -1) {
2817 		err = got_error_from_errno("asprintf");
2818 		goto done;
2819 	}
2820 	if (status == GOT_STATUS_DELETE) {
2821 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
2822 	} else {
2823 		if (lstat(ct->ondisk_path, &sb) != 0) {
2824 			err = got_error_from_errno2("lstat", ct->ondisk_path);
2825 			goto done;
2826 		}
2827 		ct->mode = sb.st_mode;
2828 	}
2829 
2830 	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
2831 	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
2832 	    relpath) == -1) {
2833 		err = got_error_from_errno("asprintf");
2834 		goto done;
2835 	}
2836 
2837 	ct->status = status;
2838 	ct->blob_id = NULL; /* will be filled in when blob gets created */
2839 	if (ct->status != GOT_STATUS_ADD) {
2840 		ct->base_blob_id = got_object_id_dup(blob_id);
2841 		if (ct->base_blob_id == NULL) {
2842 			err = got_error_from_errno("got_object_id_dup");
2843 			goto done;
2844 		}
2845 		ct->base_commit_id = got_object_id_dup(commit_id);
2846 		if (ct->base_commit_id == NULL) {
2847 			err = got_error_from_errno("got_object_id_dup");
2848 			goto done;
2849 		}
2850 	}
2851 	ct->path = strdup(path);
2852 	if (ct->path == NULL) {
2853 		err = got_error_from_errno("strdup");
2854 		goto done;
2855 	}
2856 	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
2857 done:
2858 	if (ct && (err || new == NULL))
2859 		free_commitable(ct);
2860 	free(parent_path);
2861 	free(path);
2862 	return err;
2863 }
2864 
2865 static const struct got_error *write_tree(struct got_object_id **,
2866     struct got_tree_object *, const char *, struct got_pathlist_head *,
2867     got_worktree_status_cb status_cb, void *status_arg,
2868     struct got_repository *);
2869 
2870 static const struct got_error *
2871 write_subtree(struct got_object_id **new_subtree_id,
2872     struct got_tree_entry *te, const char *parent_path,
2873     struct got_pathlist_head *commitable_paths,
2874     got_worktree_status_cb status_cb, void *status_arg,
2875     struct got_repository *repo)
2876 {
2877 	const struct got_error *err = NULL;
2878 	struct got_tree_object *subtree;
2879 	char *subpath;
2880 
2881 	if (asprintf(&subpath, "%s%s%s", parent_path,
2882 	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
2883 		return got_error_from_errno("asprintf");
2884 
2885 	err = got_object_open_as_tree(&subtree, repo, te->id);
2886 	if (err)
2887 		return err;
2888 
2889 	err = write_tree(new_subtree_id, subtree, subpath, commitable_paths,
2890 	    status_cb, status_arg, repo);
2891 	got_object_tree_close(subtree);
2892 	free(subpath);
2893 	return err;
2894 }
2895 
2896 static const struct got_error *
2897 match_ct_parent_path(int *match, struct got_commitable *ct, const char *path)
2898 {
2899 	const struct got_error *err = NULL;
2900 	char *ct_parent_path = NULL;
2901 
2902 	*match = 0;
2903 
2904 	if (strchr(ct->in_repo_path, '/') == NULL) {
2905 		*match = got_path_is_root_dir(path);
2906 		return NULL;
2907 	}
2908 
2909 	err = got_path_dirname(&ct_parent_path, ct->in_repo_path);
2910 	if (err)
2911 		return err;
2912 	*match = (strcmp(path, ct_parent_path) == 0);
2913 	free(ct_parent_path);
2914 	return err;
2915 }
2916 
2917 static mode_t
2918 get_ct_file_mode(struct got_commitable *ct)
2919 {
2920 	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
2921 }
2922 
2923 static const struct got_error *
2924 alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
2925     struct got_tree_entry *te, struct got_commitable *ct)
2926 {
2927 	const struct got_error *err = NULL;
2928 
2929 	*new_te = NULL;
2930 
2931 	err = got_object_tree_entry_dup(new_te, te);
2932 	if (err)
2933 		goto done;
2934 
2935 	(*new_te)->mode = get_ct_file_mode(ct);
2936 
2937 	free((*new_te)->id);
2938 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2939 	if ((*new_te)->id == NULL) {
2940 		err = got_error_from_errno("got_object_id_dup");
2941 		goto done;
2942 	}
2943 done:
2944 	if (err && *new_te) {
2945 		got_object_tree_entry_close(*new_te);
2946 		*new_te = NULL;
2947 	}
2948 	return err;
2949 }
2950 
2951 static const struct got_error *
2952 alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
2953     struct got_commitable *ct)
2954 {
2955 	const struct got_error *err = NULL;
2956 	char *ct_name;
2957 
2958 	 *new_te = NULL;
2959 
2960 	*new_te = calloc(1, sizeof(**new_te));
2961 	if (*new_te == NULL)
2962 		return got_error_from_errno("calloc");
2963 
2964 	ct_name = basename(ct->path);
2965 	if (ct_name == NULL) {
2966 		err = got_error_from_errno2("basename", ct->path);
2967 		goto done;
2968 	}
2969 	(*new_te)->name = strdup(ct_name);
2970 	if ((*new_te)->name == NULL) {
2971 		err = got_error_from_errno("strdup");
2972 		goto done;
2973 	}
2974 
2975 	(*new_te)->mode = get_ct_file_mode(ct);
2976 
2977 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2978 	if ((*new_te)->id == NULL) {
2979 		err = got_error_from_errno("got_object_id_dup");
2980 		goto done;
2981 	}
2982 done:
2983 	if (err && *new_te) {
2984 		got_object_tree_entry_close(*new_te);
2985 		*new_te = NULL;
2986 	}
2987 	return err;
2988 }
2989 
2990 static const struct got_error *
2991 insert_tree_entry(struct got_tree_entry *new_te,
2992     struct got_pathlist_head *paths)
2993 {
2994 	const struct got_error *err = NULL;
2995 	struct got_pathlist_entry *new_pe;
2996 
2997 	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
2998 	if (err)
2999 		return err;
3000 	if (new_pe == NULL)
3001 		return got_error(GOT_ERR_TREE_DUP_ENTRY);
3002 	return NULL;
3003 }
3004 
3005 static const struct got_error *
3006 report_ct_status(struct got_commitable *ct,
3007     got_worktree_status_cb status_cb, void *status_arg)
3008 {
3009 	const char *ct_path = ct->path;
3010 	while (ct_path[0] == '/')
3011 		ct_path++;
3012 	return (*status_cb)(status_arg, ct->status, ct_path, ct->blob_id, NULL);
3013 }
3014 
3015 static const struct got_error *
3016 match_modified_subtree(int *modified, struct got_tree_entry *te,
3017     const char *base_tree_path, struct got_pathlist_head *commitable_paths)
3018 {
3019 	const struct got_error *err = NULL;
3020 	struct got_pathlist_entry *pe;
3021 	char *te_path;
3022 
3023 	*modified = 0;
3024 
3025 	if (asprintf(&te_path, "%s%s%s", base_tree_path,
3026 	    got_path_is_root_dir(base_tree_path) ? "" : "/",
3027 	    te->name) == -1)
3028 		return got_error_from_errno("asprintf");
3029 
3030 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3031 		struct got_commitable *ct = pe->data;
3032 		*modified = got_path_is_child(ct->in_repo_path, te_path,
3033 		    strlen(te_path));
3034 		 if (*modified)
3035 			break;
3036 	}
3037 
3038 	free(te_path);
3039 	return err;
3040 }
3041 
3042 static const struct got_error *
3043 match_deleted_or_modified_ct(struct got_commitable **ctp,
3044     struct got_tree_entry *te, const char *base_tree_path,
3045     struct got_pathlist_head *commitable_paths)
3046 {
3047 	const struct got_error *err = NULL;
3048 	struct got_pathlist_entry *pe;
3049 
3050 	*ctp = NULL;
3051 
3052 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3053 		struct got_commitable *ct = pe->data;
3054 		char *ct_name = NULL;
3055 		int path_matches;
3056 
3057 		if (ct->status != GOT_STATUS_MODIFY &&
3058 		    ct->status != GOT_STATUS_DELETE)
3059 			continue;
3060 
3061 		if (got_object_id_cmp(ct->base_blob_id, te->id) != 0)
3062 			continue;
3063 
3064 		 err = match_ct_parent_path(&path_matches, ct, base_tree_path);
3065 		 if (err)
3066 			return err;
3067 		if (!path_matches)
3068 			continue;
3069 
3070 		ct_name = basename(pe->path);
3071 		if (ct_name == NULL)
3072 			return got_error_from_errno2("basename", pe->path);
3073 
3074 		if (strcmp(te->name, ct_name) != 0)
3075 			continue;
3076 
3077 		*ctp = ct;
3078 		break;
3079 	}
3080 
3081 	return err;
3082 }
3083 
3084 static const struct got_error *
3085 make_subtree_for_added_blob(struct got_tree_entry **new_tep,
3086     const char *child_path, const char *path_base_tree,
3087     struct got_pathlist_head *commitable_paths,
3088     got_worktree_status_cb status_cb, void *status_arg,
3089     struct got_repository *repo)
3090 {
3091 	const struct got_error *err = NULL;
3092 	struct got_tree_entry *new_te;
3093 	char *subtree_path;
3094 
3095 	*new_tep = NULL;
3096 
3097 	if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
3098 	    got_path_is_root_dir(path_base_tree) ? "" : "/",
3099 	    child_path) == -1)
3100 		return got_error_from_errno("asprintf");
3101 
3102 	new_te = calloc(1, sizeof(*new_te));
3103 	new_te->mode = S_IFDIR;
3104 	new_te->name = strdup(child_path);
3105 	if (new_te->name == NULL) {
3106 		err = got_error_from_errno("strdup");
3107 		got_object_tree_entry_close(new_te);
3108 		goto done;
3109 	}
3110 	err = write_tree(&new_te->id, NULL, subtree_path,
3111 	    commitable_paths, status_cb, status_arg, repo);
3112 	if (err) {
3113 		got_object_tree_entry_close(new_te);
3114 		goto done;
3115 	}
3116 done:
3117 	free(subtree_path);
3118 	if (err == NULL)
3119 		*new_tep = new_te;
3120 	return err;
3121 }
3122 
3123 static const struct got_error *
3124 write_tree(struct got_object_id **new_tree_id,
3125     struct got_tree_object *base_tree, const char *path_base_tree,
3126     struct got_pathlist_head *commitable_paths,
3127     got_worktree_status_cb status_cb, void *status_arg,
3128     struct got_repository *repo)
3129 {
3130 	const struct got_error *err = NULL;
3131 	const struct got_tree_entries *base_entries = NULL;
3132 	struct got_pathlist_head paths;
3133 	struct got_tree_entries new_tree_entries;
3134 	struct got_tree_entry *te, *new_te = NULL;
3135 	struct got_pathlist_entry *pe;
3136 
3137 	TAILQ_INIT(&paths);
3138 	new_tree_entries.nentries = 0;
3139 	SIMPLEQ_INIT(&new_tree_entries.head);
3140 
3141 	/* Insert, and recurse into, newly added entries first. */
3142 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3143 		struct got_commitable *ct = pe->data;
3144 		char *child_path = NULL, *slash;
3145 
3146 		if (ct->status != GOT_STATUS_ADD ||
3147 		    (ct->flags & GOT_COMMITABLE_ADDED))
3148 			continue;
3149 
3150 		 if (!got_path_is_child(pe->path, path_base_tree,
3151 		     strlen(path_base_tree)))
3152 			continue;
3153 
3154 		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
3155 		    pe->path);
3156 		if (err)
3157 			goto done;
3158 
3159 		slash = strchr(child_path, '/');
3160 		if (slash == NULL) {
3161 			err = alloc_added_blob_tree_entry(&new_te, ct);
3162 			if (err)
3163 				goto done;
3164 			err = report_ct_status(ct, status_cb, status_arg);
3165 			if (err)
3166 				goto done;
3167 			ct->flags |= GOT_COMMITABLE_ADDED;
3168 			err = insert_tree_entry(new_te, &paths);
3169 			if (err)
3170 				goto done;
3171 		} else {
3172 			*slash = '\0'; /* trim trailing path components */
3173 			if (base_tree == NULL ||
3174 			    got_object_tree_find_entry(base_tree, child_path)
3175 			    == NULL) {
3176 				err = make_subtree_for_added_blob(&new_te,
3177 				    child_path, path_base_tree,
3178 				    commitable_paths, status_cb, status_arg,
3179 				    repo);
3180 				if (err)
3181 					goto done;
3182 				err = insert_tree_entry(new_te, &paths);
3183 				if (err)
3184 					goto done;
3185 			}
3186 		}
3187 	}
3188 
3189 	if (base_tree) {
3190 		/* Handle modified and deleted entries. */
3191 		base_entries = got_object_tree_get_entries(base_tree);
3192 		SIMPLEQ_FOREACH(te, &base_entries->head, entry) {
3193 			struct got_commitable *ct = NULL;
3194 
3195 			if (S_ISDIR(te->mode)) {
3196 				int modified;
3197 				err = got_object_tree_entry_dup(&new_te, te);
3198 				if (err)
3199 					goto done;
3200 				err = match_modified_subtree(&modified, te,
3201 				    path_base_tree, commitable_paths);
3202 				if (err)
3203 					goto done;
3204 				/* Avoid recursion into unmodified subtrees. */
3205 				if (modified) {
3206 					free(new_te->id);
3207 					err = write_subtree(&new_te->id, te,
3208 					    path_base_tree, commitable_paths,
3209 					    status_cb, status_arg, repo);
3210 					if (err)
3211 						goto done;
3212 				}
3213 				err = insert_tree_entry(new_te, &paths);
3214 				if (err)
3215 					goto done;
3216 				continue;
3217 			}
3218 
3219 			err = match_deleted_or_modified_ct(&ct, te,
3220 			    path_base_tree, commitable_paths);
3221 			if (ct) {
3222 				/* NB: Deleted entries get dropped here. */
3223 				if (ct->status == GOT_STATUS_MODIFY) {
3224 					err = alloc_modified_blob_tree_entry(
3225 					    &new_te, te, ct);
3226 					if (err)
3227 						goto done;
3228 					err = insert_tree_entry(new_te, &paths);
3229 					if (err)
3230 						goto done;
3231 				}
3232 				err = report_ct_status(ct, status_cb,
3233 				    status_arg);
3234 				if (err)
3235 					goto done;
3236 			} else {
3237 				/* Entry is unchanged; just copy it. */
3238 				err = got_object_tree_entry_dup(&new_te, te);
3239 				if (err)
3240 					goto done;
3241 				err = insert_tree_entry(new_te, &paths);
3242 				if (err)
3243 					goto done;
3244 			}
3245 		}
3246 	}
3247 
3248 	/* Write new list of entries; deleted entries have been dropped. */
3249 	TAILQ_FOREACH(pe, &paths, entry) {
3250 		struct got_tree_entry *te = pe->data;
3251 		new_tree_entries.nentries++;
3252 		SIMPLEQ_INSERT_TAIL(&new_tree_entries.head, te, entry);
3253 	}
3254 	err = got_object_tree_create(new_tree_id, &new_tree_entries, repo);
3255 done:
3256 	got_object_tree_entries_close(&new_tree_entries);
3257 	got_pathlist_free(&paths);
3258 	return err;
3259 }
3260 
3261 static const struct got_error *
3262 update_fileindex_after_commit(struct got_pathlist_head *commitable_paths,
3263     struct got_object_id *new_base_commit_id, struct got_fileindex *fileindex)
3264 {
3265 	const struct got_error *err = NULL;
3266 	struct got_pathlist_entry *pe;
3267 
3268 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3269 		struct got_fileindex_entry *ie;
3270 		struct got_commitable *ct = pe->data;
3271 
3272 		ie = got_fileindex_entry_get(fileindex, pe->path);
3273 		if (ie) {
3274 			if (ct->status == GOT_STATUS_DELETE) {
3275 				got_fileindex_entry_remove(fileindex, ie);
3276 				got_fileindex_entry_free(ie);
3277 			} else
3278 				err = got_fileindex_entry_update(ie,
3279 				    ct->ondisk_path, ct->blob_id->sha1,
3280 				    new_base_commit_id->sha1, 1);
3281 		} else {
3282 			err = got_fileindex_entry_alloc(&ie,
3283 			    ct->ondisk_path, pe->path, ct->blob_id->sha1,
3284 			    new_base_commit_id->sha1);
3285 			if (err)
3286 				break;
3287 			err = got_fileindex_entry_add(fileindex, ie);
3288 			if (err)
3289 				break;
3290 		}
3291 	}
3292 	return err;
3293 }
3294 
3295 static const struct got_error *
3296 check_ct_out_of_date(struct got_commitable *ct, struct got_repository *repo,
3297 	struct got_object_id *head_commit_id)
3298 {
3299 	const struct got_error *err = NULL;
3300 	struct got_object_id *id_in_head = NULL, *id = NULL;
3301 	struct got_commit_object *commit = NULL;
3302 	char *path = NULL;
3303 	const char *ct_path = ct->in_repo_path;
3304 
3305 	while (ct_path[0] == '/')
3306 		ct_path++;
3307 
3308 	/*
3309 	 * Ensure that no modifications were made to files *and their parents*
3310 	 * in commits between the file's base commit and the branch head.
3311 	 *
3312 	 * Checking the parents is important for detecting conflicting tree
3313 	 * configurations (files or parent folders might have been moved,
3314 	 * deleted, added again, etc.). Such changes need to be merged with
3315 	 * local changes before a commit can occur.
3316 	 *
3317 	 * The implication is that the file's (parent) entry in the root
3318 	 * directory must have the same ID in all relevant commits.
3319 	 */
3320 	if (ct->status != GOT_STATUS_ADD) {
3321 		struct got_object_qid *pid;
3322 		char *slash;
3323 		struct got_object_id *root_entry_id = NULL;
3324 
3325 		/* Trivial case: base commit == head commit */
3326 		if (got_object_id_cmp(ct->base_commit_id, head_commit_id) == 0)
3327 			return NULL;
3328 
3329 		/* Compute the path to the root directory's entry. */
3330 		path = strdup(ct_path);
3331 		if (path == NULL) {
3332 			err = got_error_from_errno("strdup");
3333 			goto done;
3334 		}
3335 		slash = strchr(path, '/');
3336 		if (slash)
3337 			*slash = '\0';
3338 
3339 		err = got_object_open_as_commit(&commit, repo, head_commit_id);
3340 		if (err)
3341 			goto done;
3342 
3343 		err = got_object_id_by_path(&root_entry_id, repo,
3344 		    head_commit_id, path);
3345 		if (err)
3346 			goto done;
3347 
3348 		pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(commit));
3349 		while (pid) {
3350 			struct got_commit_object *pcommit;
3351 
3352 			err = got_object_id_by_path(&id, repo, pid->id, path);
3353 			if (err) {
3354 				if (err->code != GOT_ERR_NO_TREE_ENTRY)
3355 					goto done;
3356 				err = NULL;
3357 				break;
3358 			}
3359 
3360 			err = got_object_id_by_path(&id, repo, pid->id, path);
3361 			if (err)
3362 				goto done;
3363 
3364 			if (got_object_id_cmp(id, root_entry_id) != 0) {
3365 				err = got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3366 				break;
3367 			}
3368 
3369 			if (got_object_id_cmp(pid->id, ct->base_commit_id) == 0)
3370 				break; /* all relevant commits scanned */
3371 
3372 			err = got_object_open_as_commit(&pcommit, repo,
3373 			    pid->id);
3374 			if (err)
3375 				goto done;
3376 
3377 			got_object_commit_close(commit);
3378 			commit = pcommit;
3379 			pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(
3380 			    commit));
3381 		}
3382 	} else {
3383 		/* Require that added files don't exist in the branch head. */
3384 		err = got_object_id_by_path(&id_in_head, repo, head_commit_id,
3385 		    ct_path);
3386 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
3387 			goto done;
3388 		err = id_in_head ? got_error(GOT_ERR_COMMIT_OUT_OF_DATE) : NULL;
3389 	}
3390 done:
3391 	if (commit)
3392 		got_object_commit_close(commit);
3393 	free(id_in_head);
3394 	free(id);
3395 	free(path);
3396 	return err;
3397 }
3398 
3399 const struct got_error *
3400 commit_worktree(struct got_object_id **new_commit_id,
3401     struct got_pathlist_head *commitable_paths,
3402     struct got_object_id *head_commit_id, struct got_worktree *worktree,
3403     const char *ondisk_path, const char *author, const char *committer,
3404     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3405     got_worktree_status_cb status_cb, void *status_arg,
3406     struct got_repository *repo)
3407 {
3408 	const struct got_error *err = NULL, *unlockerr = NULL;
3409 	struct got_pathlist_entry *pe;
3410 	const char *head_ref_name = NULL;
3411 	struct got_commit_object *head_commit = NULL;
3412 	struct got_reference *head_ref2 = NULL;
3413 	struct got_object_id *head_commit_id2 = NULL;
3414 	struct got_tree_object *head_tree = NULL;
3415 	struct got_object_id *new_tree_id = NULL;
3416 	struct got_object_id_queue parent_ids;
3417 	struct got_object_qid *pid = NULL;
3418 	char *logmsg = NULL;
3419 
3420 	*new_commit_id = NULL;
3421 
3422 	SIMPLEQ_INIT(&parent_ids);
3423 
3424 	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
3425 	if (err)
3426 		goto done;
3427 
3428 	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
3429 	if (err)
3430 		goto done;
3431 
3432 	if (commit_msg_cb != NULL) {
3433 		err = commit_msg_cb(commitable_paths, &logmsg, commit_arg);
3434 		if (err)
3435 			goto done;
3436 	}
3437 
3438 	if (logmsg == NULL || strlen(logmsg) == 0) {
3439 		err = got_error(GOT_ERR_COMMIT_MSG_EMPTY);
3440 		goto done;
3441 	}
3442 
3443 	/* Create blobs from added and modified files and record their IDs. */
3444 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3445 		struct got_commitable *ct = pe->data;
3446 		char *ondisk_path;
3447 
3448 		if (ct->status != GOT_STATUS_ADD &&
3449 		    ct->status != GOT_STATUS_MODIFY)
3450 			continue;
3451 
3452 		if (asprintf(&ondisk_path, "%s/%s",
3453 		    worktree->root_path, pe->path) == -1) {
3454 			err = got_error_from_errno("asprintf");
3455 			goto done;
3456 		}
3457 		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
3458 		free(ondisk_path);
3459 		if (err)
3460 			goto done;
3461 	}
3462 
3463 	/* Recursively write new tree objects. */
3464 	err = write_tree(&new_tree_id, head_tree, "/", commitable_paths,
3465 	    status_cb, status_arg, repo);
3466 	if (err)
3467 		goto done;
3468 
3469 	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
3470 	if (err)
3471 		goto done;
3472 	SIMPLEQ_INSERT_TAIL(&parent_ids, pid, entry);
3473 	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
3474 	    1, author, time(NULL), committer, time(NULL), logmsg, repo);
3475 	got_object_qid_free(pid);
3476 	if (logmsg != NULL)
3477 		free(logmsg);
3478 	if (err)
3479 		goto done;
3480 
3481 	/* Check if a concurrent commit to our branch has occurred. */
3482 	head_ref_name = got_worktree_get_head_ref_name(worktree);
3483 	if (head_ref_name == NULL) {
3484 		err = got_error_from_errno("got_worktree_get_head_ref_name");
3485 		goto done;
3486 	}
3487 	/* Lock the reference here to prevent concurrent modification. */
3488 	err = got_ref_open(&head_ref2, repo, head_ref_name, 1);
3489 	if (err)
3490 		goto done;
3491 	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
3492 	if (err)
3493 		goto done;
3494 	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
3495 		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
3496 		goto done;
3497 	}
3498 	/* Update branch head in repository. */
3499 	err = got_ref_change_ref(head_ref2, *new_commit_id);
3500 	if (err)
3501 		goto done;
3502 	err = got_ref_write(head_ref2, repo);
3503 	if (err)
3504 		goto done;
3505 
3506 	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
3507 	if (err)
3508 		goto done;
3509 
3510 	err = ref_base_commit(worktree, repo);
3511 	if (err)
3512 		goto done;
3513 done:
3514 	if (head_tree)
3515 		got_object_tree_close(head_tree);
3516 	if (head_commit)
3517 		got_object_commit_close(head_commit);
3518 	free(head_commit_id2);
3519 	if (head_ref2) {
3520 		unlockerr = got_ref_unlock(head_ref2);
3521 		if (unlockerr && err == NULL)
3522 			err = unlockerr;
3523 		got_ref_close(head_ref2);
3524 	}
3525 	return err;
3526 }
3527 
3528 const struct got_error *
3529 got_worktree_commit(struct got_object_id **new_commit_id,
3530     struct got_worktree *worktree, const char *ondisk_path,
3531     const char *author, const char *committer,
3532     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3533     got_worktree_status_cb status_cb, void *status_arg,
3534     struct got_repository *repo)
3535 {
3536 	const struct got_error *err = NULL, *unlockerr = NULL, *sync_err;
3537 	struct got_fileindex *fileindex = NULL;
3538 	char *fileindex_path = NULL, *relpath = NULL;
3539 	struct got_pathlist_head commitable_paths;
3540 	struct collect_commitables_arg cc_arg;
3541 	struct got_pathlist_entry *pe;
3542 	struct got_reference *head_ref = NULL;
3543 	struct got_object_id *head_commit_id = NULL;
3544 
3545 	*new_commit_id = NULL;
3546 
3547 	TAILQ_INIT(&commitable_paths);
3548 
3549 	err = lock_worktree(worktree, LOCK_EX);
3550 	if (err)
3551 		goto done;
3552 
3553 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3554 	if (err)
3555 		goto done;
3556 
3557 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3558 	if (err)
3559 		goto done;
3560 
3561 	if (ondisk_path) {
3562 		if (strcmp(ondisk_path, worktree->root_path) == 0) {
3563 			relpath = strdup("");
3564 			if (relpath == NULL) {
3565 				err = got_error_from_errno("strdup");
3566 				goto done;
3567 			}
3568 		} else {
3569 			err = got_path_skip_common_ancestor(&relpath,
3570 			    worktree->root_path, ondisk_path);
3571 			if (err)
3572 				return err;
3573 		}
3574 	}
3575 
3576 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3577 	if (err)
3578 		goto done;
3579 
3580 	cc_arg.commitable_paths = &commitable_paths;
3581 	cc_arg.worktree = worktree;
3582 	cc_arg.repo = repo;
3583 	err = worktree_status(worktree, relpath ? relpath : "",
3584 	    fileindex, repo, collect_commitables, &cc_arg, NULL, NULL);
3585 	if (err)
3586 		goto done;
3587 
3588 	if (TAILQ_EMPTY(&commitable_paths)) {
3589 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3590 		goto done;
3591 	}
3592 
3593 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3594 		struct got_commitable *ct = pe->data;
3595 		err = check_ct_out_of_date(ct, repo, head_commit_id);
3596 		if (err)
3597 			goto done;
3598 	}
3599 
3600 	err = commit_worktree(new_commit_id, &commitable_paths,
3601 	    head_commit_id, worktree, ondisk_path, author, committer,
3602 	    commit_msg_cb, commit_arg, status_cb, status_arg, repo);
3603 	if (err)
3604 		goto done;
3605 
3606 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
3607 	    fileindex);
3608 	sync_err = sync_fileindex(fileindex, fileindex_path);
3609 	if (sync_err && err == NULL)
3610 		err = sync_err;
3611 done:
3612 	if (fileindex)
3613 		got_fileindex_free(fileindex);
3614 	free(fileindex_path);
3615 	free(relpath);
3616 	unlockerr = lock_worktree(worktree, LOCK_SH);
3617 	if (unlockerr && err == NULL)
3618 		err = unlockerr;
3619 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3620 		struct got_commitable *ct = pe->data;
3621 		free_commitable(ct);
3622 	}
3623 	got_pathlist_free(&commitable_paths);
3624 	return err;
3625 }
3626 
3627 const char *
3628 got_commitable_get_path(struct got_commitable *ct)
3629 {
3630 	return ct->path;
3631 }
3632 
3633 unsigned int
3634 got_commitable_get_status(struct got_commitable *ct)
3635 {
3636 	return ct->status;
3637 }
3638 
3639 struct check_rebase_ok_arg {
3640 	struct got_worktree *worktree;
3641 	struct got_repository *repo;
3642 };
3643 
3644 static const struct got_error *
3645 check_rebase_ok(void *arg, struct got_fileindex_entry *ie)
3646 {
3647 	const struct got_error *err = NULL;
3648 	struct check_rebase_ok_arg *a = arg;
3649 	unsigned char status;
3650 	struct stat sb;
3651 	char *ondisk_path;
3652 
3653 	/* Reject rebase of a work tree with mixed base commits. */
3654 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
3655 	    SHA1_DIGEST_LENGTH))
3656 		return got_error(GOT_ERR_MIXED_COMMITS);
3657 
3658 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
3659 	    == -1)
3660 		return got_error_from_errno("asprintf");
3661 
3662 	/* Reject rebase of a work tree with modified or conflicted files. */
3663 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
3664 	free(ondisk_path);
3665 	if (err)
3666 		return err;
3667 
3668 	if (status != GOT_STATUS_NO_CHANGE)
3669 		return got_error(GOT_ERR_MODIFIED);
3670 
3671 	return NULL;
3672 }
3673 
3674 const struct got_error *
3675 got_worktree_rebase_prepare(struct got_reference **new_base_branch_ref,
3676     struct got_reference **tmp_branch, struct got_fileindex **fileindex,
3677     struct got_worktree *worktree, struct got_reference *branch,
3678     struct got_repository *repo)
3679 {
3680 	const struct got_error *err = NULL;
3681 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
3682 	char *branch_ref_name = NULL;
3683 	char *fileindex_path = NULL;
3684 	struct check_rebase_ok_arg ok_arg;
3685 	struct got_reference *wt_branch = NULL, *branch_ref = NULL;
3686 
3687 	*new_base_branch_ref = NULL;
3688 	*tmp_branch = NULL;
3689 	*fileindex = NULL;
3690 
3691 	err = lock_worktree(worktree, LOCK_EX);
3692 	if (err)
3693 		return err;
3694 
3695 	err = open_fileindex(fileindex, &fileindex_path, worktree);
3696 	if (err)
3697 		goto done;
3698 
3699 	ok_arg.worktree = worktree;
3700 	ok_arg.repo = repo;
3701 	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
3702 	    &ok_arg);
3703 	if (err)
3704 		goto done;
3705 
3706 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3707 	if (err)
3708 		goto done;
3709 
3710 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3711 	if (err)
3712 		goto done;
3713 
3714 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3715 	if (err)
3716 		goto done;
3717 
3718 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
3719 	    0);
3720 	if (err)
3721 		goto done;
3722 
3723 	err = got_ref_alloc_symref(new_base_branch_ref,
3724 	    new_base_branch_ref_name, wt_branch);
3725 	if (err)
3726 		goto done;
3727 	err = got_ref_write(*new_base_branch_ref, repo);
3728 	if (err)
3729 		goto done;
3730 
3731 	/* TODO Lock original branch's ref while rebasing? */
3732 
3733 	err = got_ref_alloc_symref(&branch_ref, branch_ref_name, branch);
3734 	if (err)
3735 		goto done;
3736 
3737 	err = got_ref_write(branch_ref, repo);
3738 	if (err)
3739 		goto done;
3740 
3741 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
3742 	    worktree->base_commit_id);
3743 	if (err)
3744 		goto done;
3745 	err = got_ref_write(*tmp_branch, repo);
3746 	if (err)
3747 		goto done;
3748 
3749 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
3750 	if (err)
3751 		goto done;
3752 done:
3753 	free(fileindex_path);
3754 	free(tmp_branch_name);
3755 	free(new_base_branch_ref_name);
3756 	free(branch_ref_name);
3757 	if (branch_ref)
3758 		got_ref_close(branch_ref);
3759 	if (wt_branch)
3760 		got_ref_close(wt_branch);
3761 	if (err) {
3762 		if (*new_base_branch_ref) {
3763 			got_ref_close(*new_base_branch_ref);
3764 			*new_base_branch_ref = NULL;
3765 		}
3766 		if (*tmp_branch) {
3767 			got_ref_close(*tmp_branch);
3768 			*tmp_branch = NULL;
3769 		}
3770 		if (*fileindex) {
3771 			got_fileindex_free(*fileindex);
3772 			*fileindex = NULL;
3773 		}
3774 		lock_worktree(worktree, LOCK_SH);
3775 	}
3776 	return err;
3777 }
3778 
3779 const struct got_error *
3780 got_worktree_rebase_continue(struct got_object_id **commit_id,
3781     struct got_reference **new_base_branch, struct got_reference **tmp_branch,
3782     struct got_reference **branch, struct got_fileindex **fileindex,
3783     struct got_worktree *worktree, struct got_repository *repo)
3784 {
3785 	const struct got_error *err;
3786 	char *commit_ref_name = NULL, *new_base_branch_ref_name = NULL;
3787 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
3788 	struct got_reference *commit_ref = NULL, *branch_ref = NULL;
3789 	char *fileindex_path = NULL;
3790 
3791 	*commit_id = NULL;
3792 	*new_base_branch = NULL;
3793 	*tmp_branch = NULL;
3794 	*branch = NULL;
3795 	*fileindex = NULL;
3796 
3797 	err = lock_worktree(worktree, LOCK_EX);
3798 	if (err)
3799 		return err;
3800 
3801 	err = open_fileindex(fileindex, &fileindex_path, worktree);
3802 	if (err)
3803 		goto done;
3804 
3805 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3806 	if (err)
3807 		return err;
3808 
3809 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3810 	if (err)
3811 		goto done;
3812 
3813 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3814 	if (err)
3815 		goto done;
3816 
3817 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3818 	if (err)
3819 		goto done;
3820 
3821 	err = got_ref_open(&branch_ref, repo, branch_ref_name, 0);
3822 	if (err)
3823 		goto done;
3824 
3825 	err = got_ref_open(branch, repo,
3826 	    got_ref_get_symref_target(branch_ref), 0);
3827 	if (err)
3828 		goto done;
3829 
3830 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3831 	if (err)
3832 		goto done;
3833 
3834 	err = got_ref_resolve(commit_id, repo, commit_ref);
3835 	if (err)
3836 		goto done;
3837 
3838 	err = got_ref_open(new_base_branch, repo,
3839 	    new_base_branch_ref_name, 0);
3840 	if (err)
3841 		goto done;
3842 
3843 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
3844 	if (err)
3845 		goto done;
3846 done:
3847 	free(commit_ref_name);
3848 	free(branch_ref_name);
3849 	free(fileindex_path);
3850 	if (commit_ref)
3851 		got_ref_close(commit_ref);
3852 	if (branch_ref)
3853 		got_ref_close(branch_ref);
3854 	if (err) {
3855 		free(*commit_id);
3856 		*commit_id = NULL;
3857 		if (*tmp_branch) {
3858 			got_ref_close(*tmp_branch);
3859 			*tmp_branch = NULL;
3860 		}
3861 		if (*new_base_branch) {
3862 			got_ref_close(*new_base_branch);
3863 			*new_base_branch = NULL;
3864 		}
3865 		if (*branch) {
3866 			got_ref_close(*branch);
3867 			*branch = NULL;
3868 		}
3869 		if (*fileindex) {
3870 			got_fileindex_free(*fileindex);
3871 			*fileindex = NULL;
3872 		}
3873 		lock_worktree(worktree, LOCK_SH);
3874 	}
3875 	return err;
3876 }
3877 
3878 const struct got_error *
3879 got_worktree_rebase_in_progress(int *in_progress, struct got_worktree *worktree)
3880 {
3881 	const struct got_error *err;
3882 	char *tmp_branch_name = NULL;
3883 
3884 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3885 	if (err)
3886 		return err;
3887 
3888 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
3889 	free(tmp_branch_name);
3890 	return NULL;
3891 }
3892 
3893 static const struct got_error *
3894 collect_rebase_commit_msg(struct got_pathlist_head *commitable_paths,
3895     char **logmsg, void *arg)
3896 {
3897 	*logmsg = arg;
3898 	return NULL;
3899 }
3900 
3901 static const struct got_error *
3902 rebase_status(void *arg, unsigned char status, const char *path,
3903     struct got_object_id *blob_id, struct got_object_id *commit_id)
3904 {
3905 	return NULL;
3906 }
3907 
3908 struct collect_merged_paths_arg {
3909 	got_worktree_checkout_cb progress_cb;
3910 	void *progress_arg;
3911 	struct got_pathlist_head *merged_paths;
3912 };
3913 
3914 static const struct got_error *
3915 collect_merged_paths(void *arg, unsigned char status, const char *path)
3916 {
3917 	const struct got_error *err;
3918 	struct collect_merged_paths_arg *a = arg;
3919 	char *p;
3920 	struct got_pathlist_entry *new;
3921 
3922 	err = (*a->progress_cb)(a->progress_arg, status, path);
3923 	if (err)
3924 		return err;
3925 
3926 	if (status != GOT_STATUS_MERGE &&
3927 	    status != GOT_STATUS_ADD &&
3928 	    status != GOT_STATUS_DELETE &&
3929 	    status != GOT_STATUS_CONFLICT)
3930 		return NULL;
3931 
3932 	p = strdup(path);
3933 	if (p == NULL)
3934 		return got_error_from_errno("strdup");
3935 
3936 	err = got_pathlist_insert(&new, a->merged_paths, p, NULL);
3937 	if (err || new == NULL)
3938 		free(p);
3939 	return err;
3940 }
3941 
3942 void
3943 got_worktree_rebase_pathlist_free(struct got_pathlist_head *merged_paths)
3944 {
3945 	struct got_pathlist_entry *pe;
3946 
3947 	TAILQ_FOREACH(pe, merged_paths, entry)
3948 		free((char *)pe->path);
3949 
3950 	got_pathlist_free(merged_paths);
3951 }
3952 
3953 static const struct got_error *
3954 store_commit_id(const char *commit_ref_name, struct got_object_id *commit_id,
3955     struct got_repository *repo)
3956 {
3957 	const struct got_error *err;
3958 	struct got_reference *commit_ref = NULL;
3959 
3960 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3961 	if (err) {
3962 		if (err->code != GOT_ERR_NOT_REF)
3963 			goto done;
3964 		err = got_ref_alloc(&commit_ref, commit_ref_name, commit_id);
3965 		if (err)
3966 			goto done;
3967 		err = got_ref_write(commit_ref, repo);
3968 		if (err)
3969 			goto done;
3970 	} else {
3971 		struct got_object_id *stored_id;
3972 		int cmp;
3973 
3974 		err = got_ref_resolve(&stored_id, repo, commit_ref);
3975 		if (err)
3976 			goto done;
3977 		cmp = got_object_id_cmp(commit_id, stored_id);
3978 		free(stored_id);
3979 		if (cmp != 0) {
3980 			err = got_error(GOT_ERR_REBASE_COMMITID);
3981 			goto done;
3982 		}
3983 	}
3984 done:
3985 	if (commit_ref)
3986 		got_ref_close(commit_ref);
3987 	return err;
3988 }
3989 
3990 static const struct got_error *
3991 rebase_merge_files(struct got_pathlist_head *merged_paths,
3992     const char *commit_ref_name, struct got_worktree *worktree,
3993     struct got_fileindex *fileindex, struct got_object_id *parent_commit_id,
3994     struct got_object_id *commit_id, struct got_repository *repo,
3995     got_worktree_checkout_cb progress_cb, void *progress_arg,
3996     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
3997 {
3998 	const struct got_error *err;
3999 	struct got_reference *commit_ref = NULL;
4000 	struct collect_merged_paths_arg cmp_arg;
4001 	char *fileindex_path;
4002 
4003 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
4004 
4005 	err = get_fileindex_path(&fileindex_path, worktree);
4006 	if (err)
4007 		return err;
4008 
4009 	cmp_arg.progress_cb = progress_cb;
4010 	cmp_arg.progress_arg = progress_arg;
4011 	cmp_arg.merged_paths = merged_paths;
4012 	err = merge_files(worktree, fileindex, fileindex_path,
4013 	    parent_commit_id, commit_id, repo, collect_merged_paths,
4014 	    &cmp_arg, cancel_cb, cancel_arg);
4015 	if (commit_ref)
4016 		got_ref_close(commit_ref);
4017 	return err;
4018 }
4019 
4020 const struct got_error *
4021 got_worktree_rebase_merge_files(struct got_pathlist_head *merged_paths,
4022     struct got_worktree *worktree, struct got_fileindex *fileindex,
4023     struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
4024     struct got_repository *repo,
4025     got_worktree_checkout_cb progress_cb, void *progress_arg,
4026     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
4027 {
4028 	const struct got_error *err;
4029 	char *commit_ref_name;
4030 
4031 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4032 	if (err)
4033 		return err;
4034 
4035 	err = store_commit_id(commit_ref_name, commit_id, repo);
4036 	if (err)
4037 		goto done;
4038 
4039 	err = rebase_merge_files(merged_paths, commit_ref_name, worktree,
4040 	    fileindex, parent_commit_id, commit_id, repo, progress_cb,
4041 	    progress_arg, cancel_cb, cancel_arg);
4042 done:
4043 	free(commit_ref_name);
4044 	return err;
4045 }
4046 
4047 const struct got_error *
4048 got_worktree_histedit_merge_files(struct got_pathlist_head *merged_paths,
4049     struct got_worktree *worktree, struct got_fileindex *fileindex,
4050     struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
4051     struct got_repository *repo,
4052     got_worktree_checkout_cb progress_cb, void *progress_arg,
4053     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
4054 {
4055 	const struct got_error *err;
4056 	char *commit_ref_name;
4057 
4058 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4059 	if (err)
4060 		return err;
4061 
4062 	err = store_commit_id(commit_ref_name, commit_id, repo);
4063 	if (err)
4064 		goto done;
4065 
4066 	err = rebase_merge_files(merged_paths, commit_ref_name, worktree,
4067 	    fileindex, parent_commit_id, commit_id, repo, progress_cb,
4068 	    progress_arg, cancel_cb, cancel_arg);
4069 done:
4070 	free(commit_ref_name);
4071 	return err;
4072 }
4073 
4074 static const struct got_error *
4075 rebase_commit(struct got_object_id **new_commit_id,
4076     struct got_pathlist_head *merged_paths, struct got_reference *commit_ref,
4077     struct got_worktree *worktree, struct got_fileindex *fileindex,
4078     struct got_reference *tmp_branch, struct got_commit_object *orig_commit,
4079     const char *new_logmsg, struct got_repository *repo)
4080 {
4081 	const struct got_error *err, *sync_err;
4082 	struct got_pathlist_head commitable_paths;
4083 	struct collect_commitables_arg cc_arg;
4084 	char *fileindex_path = NULL;
4085 	struct got_reference *head_ref = NULL;
4086 	struct got_object_id *head_commit_id = NULL;
4087 	char *logmsg = NULL;
4088 
4089 	TAILQ_INIT(&commitable_paths);
4090 	*new_commit_id = NULL;
4091 
4092 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
4093 
4094 	err = get_fileindex_path(&fileindex_path, worktree);
4095 	if (err)
4096 		return err;
4097 
4098 	cc_arg.commitable_paths = &commitable_paths;
4099 	cc_arg.worktree = worktree;
4100 	cc_arg.repo = repo;
4101 	/*
4102 	 * If possible get the status of individual files directly to
4103 	 * avoid crawling the entire work tree once per rebased commit.
4104 	 * TODO: Ideally, merged_paths would contain a list of commitables
4105 	 * we could use so we could skip worktree_status() entirely.
4106 	 */
4107 	if (merged_paths) {
4108 		struct got_pathlist_entry *pe;
4109 		if (TAILQ_EMPTY(merged_paths)) {
4110 			err = got_error(GOT_ERR_NO_MERGED_PATHS);
4111 			goto done;
4112 		}
4113 		TAILQ_FOREACH(pe, merged_paths, entry) {
4114 			err = worktree_status(worktree, pe->path, fileindex,
4115 			    repo, collect_commitables, &cc_arg, NULL, NULL);
4116 			if (err)
4117 				goto done;
4118 		}
4119 	} else {
4120 		err = worktree_status(worktree, "", fileindex, repo,
4121 		    collect_commitables, &cc_arg, NULL, NULL);
4122 		if (err)
4123 			goto done;
4124 	}
4125 
4126 	if (TAILQ_EMPTY(&commitable_paths)) {
4127 		/* No-op change; commit will be elided. */
4128 		err = got_ref_delete(commit_ref, repo);
4129 		if (err)
4130 			goto done;
4131 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
4132 		goto done;
4133 	}
4134 
4135 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
4136 	if (err)
4137 		goto done;
4138 
4139 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
4140 	if (err)
4141 		goto done;
4142 
4143 	if (new_logmsg)
4144 		logmsg = strdup(new_logmsg);
4145 	else
4146 		logmsg = strdup(got_object_commit_get_logmsg(orig_commit));
4147 	if (logmsg == NULL)
4148 		return got_error_from_errno("strdup");
4149 
4150 	err = commit_worktree(new_commit_id, &commitable_paths, head_commit_id,
4151 	    worktree, NULL, got_object_commit_get_author(orig_commit),
4152 	    got_object_commit_get_committer(orig_commit),
4153 	    collect_rebase_commit_msg, logmsg, rebase_status, NULL, repo);
4154 	if (err)
4155 		goto done;
4156 
4157 	err = got_ref_change_ref(tmp_branch, *new_commit_id);
4158 	if (err)
4159 		goto done;
4160 
4161 	err = got_ref_delete(commit_ref, repo);
4162 	if (err)
4163 		goto done;
4164 
4165 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
4166 	    fileindex);
4167 	sync_err = sync_fileindex(fileindex, fileindex_path);
4168 	if (sync_err && err == NULL)
4169 		err = sync_err;
4170 done:
4171 	free(fileindex_path);
4172 	free(head_commit_id);
4173 	if (head_ref)
4174 		got_ref_close(head_ref);
4175 	if (err) {
4176 		free(*new_commit_id);
4177 		*new_commit_id = NULL;
4178 	}
4179 	return err;
4180 }
4181 
4182 const struct got_error *
4183 got_worktree_rebase_commit(struct got_object_id **new_commit_id,
4184     struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
4185     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4186     struct got_commit_object *orig_commit,
4187     struct got_object_id *orig_commit_id, struct got_repository *repo)
4188 {
4189 	const struct got_error *err;
4190 	char *commit_ref_name;
4191 	struct got_reference *commit_ref = NULL;
4192 	struct got_object_id *commit_id = NULL;
4193 
4194 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4195 	if (err)
4196 		return err;
4197 
4198 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4199 	if (err)
4200 		goto done;
4201 	err = got_ref_resolve(&commit_id, repo, commit_ref);
4202 	if (err)
4203 		goto done;
4204 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
4205 		err = got_error(GOT_ERR_REBASE_COMMITID);
4206 		goto done;
4207 	}
4208 
4209 	err = rebase_commit(new_commit_id, merged_paths, commit_ref,
4210 	    worktree, fileindex, tmp_branch, orig_commit, NULL, repo);
4211 done:
4212 	if (commit_ref)
4213 		got_ref_close(commit_ref);
4214 	free(commit_ref_name);
4215 	free(commit_id);
4216 	return err;
4217 }
4218 
4219 const struct got_error *
4220 got_worktree_histedit_commit(struct got_object_id **new_commit_id,
4221     struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
4222     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4223     struct got_commit_object *orig_commit,
4224     struct got_object_id *orig_commit_id, const char *new_logmsg,
4225     struct got_repository *repo)
4226 {
4227 	const struct got_error *err;
4228 	char *commit_ref_name;
4229 	struct got_reference *commit_ref = NULL;
4230 	struct got_object_id *commit_id = NULL;
4231 
4232 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4233 	if (err)
4234 		return err;
4235 
4236 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4237 	if (err)
4238 		goto done;
4239 	err = got_ref_resolve(&commit_id, repo, commit_ref);
4240 	if (err)
4241 		goto done;
4242 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
4243 		err = got_error(GOT_ERR_HISTEDIT_COMMITID);
4244 		goto done;
4245 	}
4246 
4247 	err = rebase_commit(new_commit_id, merged_paths, commit_ref,
4248 	    worktree, fileindex, tmp_branch, orig_commit, new_logmsg, repo);
4249 done:
4250 	if (commit_ref)
4251 		got_ref_close(commit_ref);
4252 	free(commit_ref_name);
4253 	free(commit_id);
4254 	return err;
4255 }
4256 
4257 const struct got_error *
4258 got_worktree_rebase_postpone(struct got_worktree *worktree,
4259     struct got_fileindex *fileindex)
4260 {
4261 	if (fileindex)
4262 		got_fileindex_free(fileindex);
4263 	return lock_worktree(worktree, LOCK_SH);
4264 }
4265 
4266 static const struct got_error *
4267 delete_ref(const char *name, struct got_repository *repo)
4268 {
4269 	const struct got_error *err;
4270 	struct got_reference *ref;
4271 
4272 	err = got_ref_open(&ref, repo, name, 0);
4273 	if (err) {
4274 		if (err->code == GOT_ERR_NOT_REF)
4275 			return NULL;
4276 		return err;
4277 	}
4278 
4279 	err = got_ref_delete(ref, repo);
4280 	got_ref_close(ref);
4281 	return err;
4282 }
4283 
4284 static const struct got_error *
4285 delete_rebase_refs(struct got_worktree *worktree, struct got_repository *repo)
4286 {
4287 	const struct got_error *err;
4288 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
4289 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
4290 
4291 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
4292 	if (err)
4293 		goto done;
4294 	err = delete_ref(tmp_branch_name, repo);
4295 	if (err)
4296 		goto done;
4297 
4298 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
4299 	if (err)
4300 		goto done;
4301 	err = delete_ref(new_base_branch_ref_name, repo);
4302 	if (err)
4303 		goto done;
4304 
4305 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
4306 	if (err)
4307 		goto done;
4308 	err = delete_ref(branch_ref_name, repo);
4309 	if (err)
4310 		goto done;
4311 
4312 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4313 	if (err)
4314 		goto done;
4315 	err = delete_ref(commit_ref_name, repo);
4316 	if (err)
4317 		goto done;
4318 
4319 done:
4320 	free(tmp_branch_name);
4321 	free(new_base_branch_ref_name);
4322 	free(branch_ref_name);
4323 	free(commit_ref_name);
4324 	return err;
4325 }
4326 
4327 const struct got_error *
4328 got_worktree_rebase_complete(struct got_worktree *worktree,
4329     struct got_fileindex *fileindex, struct got_reference *new_base_branch,
4330     struct got_reference *tmp_branch, struct got_reference *rebased_branch,
4331     struct got_repository *repo)
4332 {
4333 	const struct got_error *err, *unlockerr;
4334 	struct got_object_id *new_head_commit_id = NULL;
4335 
4336 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
4337 	if (err)
4338 		return err;
4339 
4340 	err = got_ref_change_ref(rebased_branch, new_head_commit_id);
4341 	if (err)
4342 		goto done;
4343 
4344 	err = got_ref_write(rebased_branch, repo);
4345 	if (err)
4346 		goto done;
4347 
4348 	err = got_worktree_set_head_ref(worktree, rebased_branch);
4349 	if (err)
4350 		goto done;
4351 
4352 	err = delete_rebase_refs(worktree, repo);
4353 done:
4354 	if (fileindex)
4355 		got_fileindex_free(fileindex);
4356 	free(new_head_commit_id);
4357 	unlockerr = lock_worktree(worktree, LOCK_SH);
4358 	if (unlockerr && err == NULL)
4359 		err = unlockerr;
4360 	return err;
4361 }
4362 
4363 struct collect_revertible_paths_arg {
4364 	struct got_pathlist_head *revertible_paths;
4365 	struct got_worktree *worktree;
4366 };
4367 
4368 static const struct got_error *
4369 collect_revertible_paths(void *arg, unsigned char status, const char *relpath,
4370     struct got_object_id *blob_id, struct got_object_id *commit_id)
4371 {
4372 	struct collect_revertible_paths_arg *a = arg;
4373 	const struct got_error *err = NULL;
4374 	struct got_pathlist_entry *new = NULL;
4375 	char *path = NULL;
4376 
4377 	if (status != GOT_STATUS_ADD &&
4378 	    status != GOT_STATUS_DELETE &&
4379 	    status != GOT_STATUS_MODIFY &&
4380 	    status != GOT_STATUS_CONFLICT &&
4381 	    status != GOT_STATUS_MISSING)
4382 		return NULL;
4383 
4384 	if (asprintf(&path, "%s/%s", a->worktree->root_path, relpath) == -1)
4385 		return got_error_from_errno("asprintf");
4386 
4387 	err = got_pathlist_insert(&new, a->revertible_paths, path, NULL);
4388 	if (err || new == NULL)
4389 		free(path);
4390 	return err;
4391 }
4392 
4393 const struct got_error *
4394 got_worktree_rebase_abort(struct got_worktree *worktree,
4395     struct got_fileindex *fileindex, struct got_repository *repo,
4396     struct got_reference *new_base_branch,
4397      got_worktree_checkout_cb progress_cb, void *progress_arg)
4398 {
4399 	const struct got_error *err, *unlockerr, *sync_err;
4400 	struct got_reference *resolved = NULL;
4401 	struct got_object_id *commit_id = NULL;
4402 	char *fileindex_path = NULL;
4403 	struct got_pathlist_head revertible_paths;
4404 	struct got_pathlist_entry *pe;
4405 	struct collect_revertible_paths_arg crp_arg;
4406 	struct got_object_id *tree_id = NULL;
4407 
4408 	TAILQ_INIT(&revertible_paths);
4409 
4410 	err = lock_worktree(worktree, LOCK_EX);
4411 	if (err)
4412 		return err;
4413 
4414 	err = got_ref_open(&resolved, repo,
4415 	    got_ref_get_symref_target(new_base_branch), 0);
4416 	if (err)
4417 		goto done;
4418 
4419 	err = got_worktree_set_head_ref(worktree, resolved);
4420 	if (err)
4421 		goto done;
4422 
4423 	/*
4424 	 * XXX commits to the base branch could have happened while
4425 	 * we were busy rebasing; should we store the original commit ID
4426 	 * when rebase begins and read it back here?
4427 	 */
4428 	err = got_ref_resolve(&commit_id, repo, resolved);
4429 	if (err)
4430 		goto done;
4431 
4432 	err = got_worktree_set_base_commit_id(worktree, repo, commit_id);
4433 	if (err)
4434 		goto done;
4435 
4436 	err = got_object_id_by_path(&tree_id, repo,
4437 	    worktree->base_commit_id, worktree->path_prefix);
4438 	if (err)
4439 		goto done;
4440 
4441 	err = delete_rebase_refs(worktree, repo);
4442 	if (err)
4443 		goto done;
4444 
4445 	err = get_fileindex_path(&fileindex_path, worktree);
4446 	if (err)
4447 		goto done;
4448 
4449 	crp_arg.revertible_paths = &revertible_paths;
4450 	crp_arg.worktree = worktree;
4451 	err = worktree_status(worktree, "", fileindex, repo,
4452 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4453 	if (err)
4454 		goto done;
4455 
4456 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4457 		err = revert_file(worktree, fileindex, pe->path,
4458 		    progress_cb, progress_arg, repo);
4459 		if (err)
4460 			goto sync;
4461 	}
4462 
4463 	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
4464 	    repo, progress_cb, progress_arg, NULL, NULL);
4465 sync:
4466 	sync_err = sync_fileindex(fileindex, fileindex_path);
4467 	if (sync_err && err == NULL)
4468 		err = sync_err;
4469 done:
4470 	got_ref_close(resolved);
4471 	free(tree_id);
4472 	free(commit_id);
4473 	if (fileindex)
4474 		got_fileindex_free(fileindex);
4475 	free(fileindex_path);
4476 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4477 		free((char *)pe->path);
4478 	got_pathlist_free(&revertible_paths);
4479 
4480 	unlockerr = lock_worktree(worktree, LOCK_SH);
4481 	if (unlockerr && err == NULL)
4482 		err = unlockerr;
4483 	return err;
4484 }
4485 
4486 const struct got_error *
4487 got_worktree_histedit_prepare(struct got_reference **tmp_branch,
4488     struct got_reference **branch_ref, struct got_object_id **base_commit_id,
4489     struct got_fileindex **fileindex, struct got_worktree *worktree,
4490     struct got_repository *repo)
4491 {
4492 	const struct got_error *err = NULL;
4493 	char *tmp_branch_name = NULL;
4494 	char *branch_ref_name = NULL;
4495 	char *base_commit_ref_name = NULL;
4496 	char *fileindex_path = NULL;
4497 	struct check_rebase_ok_arg ok_arg;
4498 	struct got_reference *wt_branch = NULL;
4499 	struct got_reference *base_commit_ref = NULL;
4500 
4501 	*tmp_branch = NULL;
4502 	*branch_ref = NULL;
4503 	*base_commit_id = NULL;
4504 	*fileindex = NULL;
4505 
4506 	err = lock_worktree(worktree, LOCK_EX);
4507 	if (err)
4508 		return err;
4509 
4510 	err = open_fileindex(fileindex, &fileindex_path, worktree);
4511 	if (err)
4512 		goto done;
4513 
4514 	ok_arg.worktree = worktree;
4515 	ok_arg.repo = repo;
4516 	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
4517 	    &ok_arg);
4518 	if (err)
4519 		goto done;
4520 
4521 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4522 	if (err)
4523 		goto done;
4524 
4525 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4526 	if (err)
4527 		goto done;
4528 
4529 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4530 	    worktree);
4531 	if (err)
4532 		goto done;
4533 
4534 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
4535 	    0);
4536 	if (err)
4537 		goto done;
4538 
4539 	err = got_ref_alloc_symref(branch_ref, branch_ref_name, wt_branch);
4540 	if (err)
4541 		goto done;
4542 
4543 	err = got_ref_write(*branch_ref, repo);
4544 	if (err)
4545 		goto done;
4546 
4547 	err = got_ref_alloc(&base_commit_ref, base_commit_ref_name,
4548 	    worktree->base_commit_id);
4549 	if (err)
4550 		goto done;
4551 	err = got_ref_write(base_commit_ref, repo);
4552 	if (err)
4553 		goto done;
4554 	*base_commit_id = got_object_id_dup(worktree->base_commit_id);
4555 	if (*base_commit_id == NULL) {
4556 		err = got_error_from_errno("got_object_id_dup");
4557 		goto done;
4558 	}
4559 
4560 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
4561 	    worktree->base_commit_id);
4562 	if (err)
4563 		goto done;
4564 	err = got_ref_write(*tmp_branch, repo);
4565 	if (err)
4566 		goto done;
4567 
4568 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
4569 	if (err)
4570 		goto done;
4571 done:
4572 	free(fileindex_path);
4573 	free(tmp_branch_name);
4574 	free(branch_ref_name);
4575 	free(base_commit_ref_name);
4576 	if (wt_branch)
4577 		got_ref_close(wt_branch);
4578 	if (err) {
4579 		if (*branch_ref) {
4580 			got_ref_close(*branch_ref);
4581 			*branch_ref = NULL;
4582 		}
4583 		if (*tmp_branch) {
4584 			got_ref_close(*tmp_branch);
4585 			*tmp_branch = NULL;
4586 		}
4587 		free(*base_commit_id);
4588 		if (*fileindex) {
4589 			got_fileindex_free(*fileindex);
4590 			*fileindex = NULL;
4591 		}
4592 		lock_worktree(worktree, LOCK_SH);
4593 	}
4594 	return err;
4595 }
4596 
4597 const struct got_error *
4598 got_worktree_histedit_postpone(struct got_worktree *worktree,
4599     struct got_fileindex *fileindex)
4600 {
4601 	if (fileindex)
4602 		got_fileindex_free(fileindex);
4603 	return lock_worktree(worktree, LOCK_SH);
4604 }
4605 
4606 const struct got_error *
4607 got_worktree_histedit_in_progress(int *in_progress,
4608     struct got_worktree *worktree)
4609 {
4610 	const struct got_error *err;
4611 	char *tmp_branch_name = NULL;
4612 
4613 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4614 	if (err)
4615 		return err;
4616 
4617 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
4618 	free(tmp_branch_name);
4619 	return NULL;
4620 }
4621 
4622 const struct got_error *
4623 got_worktree_histedit_continue(struct got_object_id **commit_id,
4624     struct got_reference **tmp_branch, struct got_reference **branch_ref,
4625     struct got_object_id **base_commit_id, struct got_fileindex **fileindex,
4626     struct got_worktree *worktree, struct got_repository *repo)
4627 {
4628 	const struct got_error *err;
4629 	char *commit_ref_name = NULL, *base_commit_ref_name = NULL;
4630 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
4631 	struct got_reference *commit_ref = NULL;
4632 	struct got_reference *base_commit_ref = NULL;
4633 	char *fileindex_path = NULL;
4634 
4635 	*commit_id = NULL;
4636 	*tmp_branch = NULL;
4637 	*base_commit_id = NULL;
4638 	*fileindex = NULL;
4639 
4640 	err = lock_worktree(worktree, LOCK_EX);
4641 	if (err)
4642 		return err;
4643 
4644 	err = open_fileindex(fileindex, &fileindex_path, worktree);
4645 	if (err)
4646 		goto done;
4647 
4648 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4649 	if (err)
4650 		return err;
4651 
4652 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4653 	if (err)
4654 		goto done;
4655 
4656 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4657 	if (err)
4658 		goto done;
4659 
4660 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4661 	    worktree);
4662 	if (err)
4663 		goto done;
4664 
4665 	err = got_ref_open(branch_ref, repo, branch_ref_name, 0);
4666 	if (err)
4667 		goto done;
4668 
4669 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
4670 	if (err)
4671 		goto done;
4672 	err = got_ref_resolve(commit_id, repo, commit_ref);
4673 	if (err)
4674 		goto done;
4675 
4676 	err = got_ref_open(&base_commit_ref, repo, base_commit_ref_name, 0);
4677 	if (err)
4678 		goto done;
4679 	err = got_ref_resolve(base_commit_id, repo, base_commit_ref);
4680 	if (err)
4681 		goto done;
4682 
4683 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
4684 	if (err)
4685 		goto done;
4686 done:
4687 	free(commit_ref_name);
4688 	free(branch_ref_name);
4689 	free(fileindex_path);
4690 	if (commit_ref)
4691 		got_ref_close(commit_ref);
4692 	if (base_commit_ref)
4693 		got_ref_close(base_commit_ref);
4694 	if (err) {
4695 		free(*commit_id);
4696 		*commit_id = NULL;
4697 		free(*base_commit_id);
4698 		*base_commit_id = NULL;
4699 		if (*tmp_branch) {
4700 			got_ref_close(*tmp_branch);
4701 			*tmp_branch = NULL;
4702 		}
4703 		if (*fileindex) {
4704 			got_fileindex_free(*fileindex);
4705 			*fileindex = NULL;
4706 		}
4707 		lock_worktree(worktree, LOCK_EX);
4708 	}
4709 	return err;
4710 }
4711 
4712 static const struct got_error *
4713 delete_histedit_refs(struct got_worktree *worktree, struct got_repository *repo)
4714 {
4715 	const struct got_error *err;
4716 	char *tmp_branch_name = NULL, *base_commit_ref_name = NULL;
4717 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
4718 
4719 	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
4720 	if (err)
4721 		goto done;
4722 	err = delete_ref(tmp_branch_name, repo);
4723 	if (err)
4724 		goto done;
4725 
4726 	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
4727 	    worktree);
4728 	if (err)
4729 		goto done;
4730 	err = delete_ref(base_commit_ref_name, repo);
4731 	if (err)
4732 		goto done;
4733 
4734 	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
4735 	if (err)
4736 		goto done;
4737 	err = delete_ref(branch_ref_name, repo);
4738 	if (err)
4739 		goto done;
4740 
4741 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4742 	if (err)
4743 		goto done;
4744 	err = delete_ref(commit_ref_name, repo);
4745 	if (err)
4746 		goto done;
4747 done:
4748 	free(tmp_branch_name);
4749 	free(base_commit_ref_name);
4750 	free(branch_ref_name);
4751 	free(commit_ref_name);
4752 	return err;
4753 }
4754 
4755 const struct got_error *
4756 got_worktree_histedit_abort(struct got_worktree *worktree,
4757     struct got_fileindex *fileindex, struct got_repository *repo,
4758     struct got_reference *branch, struct got_object_id *base_commit_id,
4759     got_worktree_checkout_cb progress_cb, void *progress_arg)
4760 {
4761 	const struct got_error *err, *unlockerr, *sync_err;
4762 	struct got_reference *resolved = NULL;
4763 	char *fileindex_path = NULL;
4764 	struct got_pathlist_head revertible_paths;
4765 	struct got_pathlist_entry *pe;
4766 	struct collect_revertible_paths_arg crp_arg;
4767 	struct got_object_id *tree_id = NULL;
4768 
4769 	TAILQ_INIT(&revertible_paths);
4770 
4771 	err = lock_worktree(worktree, LOCK_EX);
4772 	if (err)
4773 		return err;
4774 
4775 	err = got_ref_open(&resolved, repo,
4776 	    got_ref_get_symref_target(branch), 0);
4777 	if (err)
4778 		goto done;
4779 
4780 	err = got_worktree_set_head_ref(worktree, resolved);
4781 	if (err)
4782 		goto done;
4783 
4784 	err = got_worktree_set_base_commit_id(worktree, repo, base_commit_id);
4785 	if (err)
4786 		goto done;
4787 
4788 	err = got_object_id_by_path(&tree_id, repo, base_commit_id,
4789 	    worktree->path_prefix);
4790 	if (err)
4791 		goto done;
4792 
4793 	err = delete_histedit_refs(worktree, repo);
4794 	if (err)
4795 		goto done;
4796 
4797 	err = get_fileindex_path(&fileindex_path, worktree);
4798 	if (err)
4799 		goto done;
4800 
4801 	crp_arg.revertible_paths = &revertible_paths;
4802 	crp_arg.worktree = worktree;
4803 	err = worktree_status(worktree, "", fileindex, repo,
4804 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4805 	if (err)
4806 		goto done;
4807 
4808 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4809 		err = revert_file(worktree, fileindex, pe->path,
4810 		    progress_cb, progress_arg, repo);
4811 		if (err)
4812 			goto sync;
4813 	}
4814 
4815 	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
4816 	    repo, progress_cb, progress_arg, NULL, NULL);
4817 sync:
4818 	sync_err = sync_fileindex(fileindex, fileindex_path);
4819 	if (sync_err && err == NULL)
4820 		err = sync_err;
4821 done:
4822 	got_ref_close(resolved);
4823 	free(tree_id);
4824 	free(fileindex_path);
4825 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4826 		free((char *)pe->path);
4827 	got_pathlist_free(&revertible_paths);
4828 
4829 	unlockerr = lock_worktree(worktree, LOCK_SH);
4830 	if (unlockerr && err == NULL)
4831 		err = unlockerr;
4832 	return err;
4833 }
4834 
4835 const struct got_error *
4836 got_worktree_histedit_complete(struct got_worktree *worktree,
4837     struct got_fileindex *fileindex, struct got_reference *tmp_branch,
4838     struct got_reference *edited_branch, struct got_repository *repo)
4839 {
4840 	const struct got_error *err, *unlockerr;
4841 	struct got_object_id *new_head_commit_id = NULL;
4842 	struct got_reference *resolved = NULL;
4843 
4844 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
4845 	if (err)
4846 		return err;
4847 
4848 	err = got_ref_open(&resolved, repo,
4849 	    got_ref_get_symref_target(edited_branch), 0);
4850 	if (err)
4851 		goto done;
4852 
4853 	err = got_ref_change_ref(resolved, new_head_commit_id);
4854 	if (err)
4855 		goto done;
4856 
4857 	err = got_ref_write(resolved, repo);
4858 	if (err)
4859 		goto done;
4860 
4861 	err = got_worktree_set_head_ref(worktree, resolved);
4862 	if (err)
4863 		goto done;
4864 
4865 	err = delete_histedit_refs(worktree, repo);
4866 done:
4867 	if (fileindex)
4868 		got_fileindex_free(fileindex);
4869 	free(new_head_commit_id);
4870 	unlockerr = lock_worktree(worktree, LOCK_SH);
4871 	if (unlockerr && err == NULL)
4872 		err = unlockerr;
4873 	return err;
4874 }
4875 
4876 const struct got_error *
4877 got_worktree_histedit_skip_commit(struct got_worktree *worktree,
4878     struct got_object_id *commit_id, struct got_repository *repo)
4879 {
4880 	const struct got_error *err;
4881 	char *commit_ref_name;
4882 
4883 	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
4884 	if (err)
4885 		return err;
4886 
4887 	err = store_commit_id(commit_ref_name, commit_id, repo);
4888 	if (err)
4889 		goto done;
4890 
4891 	err = delete_ref(commit_ref_name, repo);
4892 done:
4893 	free(commit_ref_name);
4894 	return err;
4895 }