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 
36 #include "got_error.h"
37 #include "got_repository.h"
38 #include "got_reference.h"
39 #include "got_object.h"
40 #include "got_worktree.h"
41 #include "got_opentemp.h"
42 
43 #include "got_lib_worktree.h"
44 #include "got_lib_path.h"
45 #include "got_lib_sha1.h"
46 #include "got_lib_fileindex.h"
47 #include "got_lib_inflate.h"
48 #include "got_lib_delta.h"
49 #include "got_lib_object.h"
50 #include "got_lib_diff.h"
51 
52 #ifndef MIN
53 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
54 #endif
55 
56 static const struct got_error *
57 create_meta_file(const char *path_got, const char *name, const char *content)
58 {
59 	const struct got_error *err = NULL;
60 	char *path;
61 	int fd = -1;
62 
63 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
64 		err = got_error_from_errno();
65 		path = NULL;
66 		goto done;
67 	}
68 
69 	fd = open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
70 	    GOT_DEFAULT_FILE_MODE);
71 	if (fd == -1) {
72 		err = got_error_from_errno();
73 		goto done;
74 	}
75 
76 	if (content) {
77 		int len = dprintf(fd, "%s\n", content);
78 		if (len != strlen(content) + 1) {
79 			err = got_error_from_errno();
80 			goto done;
81 		}
82 	}
83 
84 done:
85 	if (fd != -1 && close(fd) == -1 && err == NULL)
86 		err = got_error_from_errno();
87 	free(path);
88 	return err;
89 }
90 
91 static const struct got_error *
92 update_meta_file(const char *path_got, const char *name, const char *content)
93 {
94 	const struct got_error *err = NULL;
95 	FILE *tmpfile = NULL;
96 	char *tmppath = NULL;
97 	char *path = NULL;
98 
99 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
100 		err = got_error_from_errno();
101 		path = NULL;
102 		goto done;
103 	}
104 
105 	err = got_opentemp_named(&tmppath, &tmpfile, path);
106 	if (err)
107 		goto done;
108 
109 	if (content) {
110 		int len = fprintf(tmpfile, "%s\n", content);
111 		if (len != strlen(content) + 1) {
112 			err = got_error_from_errno();
113 			goto done;
114 		}
115 	}
116 
117 	if (rename(tmppath, path) != 0) {
118 		err = got_error_from_errno();
119 		unlink(tmppath);
120 		goto done;
121 	}
122 
123 done:
124 	free(tmppath);
125 	if (fclose(tmpfile) != 0 && err == NULL)
126 		err = got_error_from_errno();
127 	return err;
128 }
129 
130 static const struct got_error *
131 read_meta_file(char **content, const char *path_got, const char *name)
132 {
133 	const struct got_error *err = NULL;
134 	char *path;
135 	int fd = -1;
136 	ssize_t n;
137 	struct stat sb;
138 
139 	*content = NULL;
140 
141 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
142 		err = got_error_from_errno();
143 		path = NULL;
144 		goto done;
145 	}
146 
147 	fd = open(path, O_RDONLY | O_NOFOLLOW);
148 	if (fd == -1) {
149 		if (errno == ENOENT)
150 			err = got_error(GOT_ERR_WORKTREE_META);
151 		else
152 			err = got_error_from_errno();
153 		goto done;
154 	}
155 	if (flock(fd, LOCK_SH | LOCK_NB) == -1) {
156 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
157 		    : got_error_from_errno());
158 		goto done;
159 	}
160 
161 	if (lstat(path, &sb) != 0) {
162 		err = got_error_from_errno();
163 		goto done;
164 	}
165 	*content = calloc(1, sb.st_size);
166 	if (*content == NULL) {
167 		err = got_error_from_errno();
168 		goto done;
169 	}
170 
171 	n = read(fd, *content, sb.st_size);
172 	if (n != sb.st_size) {
173 		err = (n == -1 ? got_error_from_errno() :
174 		    got_error(GOT_ERR_WORKTREE_META));
175 		goto done;
176 	}
177 	if ((*content)[sb.st_size - 1] != '\n') {
178 		err = got_error(GOT_ERR_WORKTREE_META);
179 		goto done;
180 	}
181 	(*content)[sb.st_size - 1] = '\0';
182 
183 done:
184 	if (fd != -1 && close(fd) == -1 && err == NULL)
185 		err = got_error_from_errno();
186 	free(path);
187 	if (err) {
188 		free(*content);
189 		*content = NULL;
190 	}
191 	return err;
192 }
193 
194 const struct got_error *
195 got_worktree_init(const char *path, struct got_reference *head_ref,
196     const char *prefix, struct got_repository *repo)
197 {
198 	const struct got_error *err = NULL;
199 	struct got_object_id *commit_id = NULL;
200 	uuid_t uuid;
201 	uint32_t uuid_status;
202 	int obj_type;
203 	char *path_got = NULL;
204 	char *refstr = NULL;
205 	char *formatstr = NULL;
206 	char *absprefix = NULL;
207 	char *basestr = NULL;
208 	char *uuidstr = NULL;
209 
210 	if (strcmp(path, got_repo_get_path(repo)) == 0) {
211 		err = got_error(GOT_ERR_WORKTREE_REPO);
212 		goto done;
213 	}
214 
215 	err = got_ref_resolve(&commit_id, repo, head_ref);
216 	if (err)
217 		return err;
218 	err = got_object_get_type(&obj_type, repo, commit_id);
219 	if (err)
220 		return err;
221 	if (obj_type != GOT_OBJ_TYPE_COMMIT)
222 		return got_error(GOT_ERR_OBJ_TYPE);
223 
224 	if (!got_path_is_absolute(prefix)) {
225 		if (asprintf(&absprefix, "/%s", prefix) == -1)
226 			return got_error_from_errno();
227 	}
228 
229 	/* Create top-level directory (may already exist). */
230 	if (mkdir(path, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
231 		err = got_error_from_errno();
232 		goto done;
233 	}
234 
235 	/* Create .got directory (may already exist). */
236 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
237 		err = got_error_from_errno();
238 		goto done;
239 	}
240 	if (mkdir(path_got, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
241 		err = got_error_from_errno();
242 		goto done;
243 	}
244 
245 	/* Create an empty lock file. */
246 	err = create_meta_file(path_got, GOT_WORKTREE_LOCK, NULL);
247 	if (err)
248 		goto done;
249 
250 	/* Create an empty file index. */
251 	err = create_meta_file(path_got, GOT_WORKTREE_FILE_INDEX, NULL);
252 	if (err)
253 		goto done;
254 
255 	/* Write the HEAD reference. */
256 	refstr = got_ref_to_str(head_ref);
257 	if (refstr == NULL) {
258 		err = got_error_from_errno();
259 		goto done;
260 	}
261 	err = create_meta_file(path_got, GOT_WORKTREE_HEAD_REF, refstr);
262 	if (err)
263 		goto done;
264 
265 	/* Record our base commit. */
266 	err = got_object_id_str(&basestr, commit_id);
267 	if (err)
268 		goto done;
269 	err = create_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, basestr);
270 	if (err)
271 		goto done;
272 
273 	/* Store path to repository. */
274 	err = create_meta_file(path_got, GOT_WORKTREE_REPOSITORY,
275 	    got_repo_get_path(repo));
276 	if (err)
277 		goto done;
278 
279 	/* Store in-repository path prefix. */
280 	err = create_meta_file(path_got, GOT_WORKTREE_PATH_PREFIX,
281 	    absprefix ? absprefix : prefix);
282 	if (err)
283 		goto done;
284 
285 	/* Generate UUID. */
286 	uuid_create(&uuid, &uuid_status);
287 	if (uuid_status != uuid_s_ok) {
288 		err = got_error_uuid(uuid_status);
289 		goto done;
290 	}
291 	uuid_to_string(&uuid, &uuidstr, &uuid_status);
292 	if (uuid_status != uuid_s_ok) {
293 		err = got_error_uuid(uuid_status);
294 		goto done;
295 	}
296 	err = create_meta_file(path_got, GOT_WORKTREE_UUID, uuidstr);
297 	if (err)
298 		goto done;
299 
300 	/* Stamp work tree with format file. */
301 	if (asprintf(&formatstr, "%d", GOT_WORKTREE_FORMAT_VERSION) == -1) {
302 		err = got_error_from_errno();
303 		goto done;
304 	}
305 	err = create_meta_file(path_got, GOT_WORKTREE_FORMAT, formatstr);
306 	if (err)
307 		goto done;
308 
309 done:
310 	free(commit_id);
311 	free(path_got);
312 	free(formatstr);
313 	free(refstr);
314 	free(absprefix);
315 	free(basestr);
316 	free(uuidstr);
317 	return err;
318 }
319 
320 static const struct got_error *
321 open_worktree(struct got_worktree **worktree, const char *path)
322 {
323 	const struct got_error *err = NULL;
324 	char *path_got;
325 	char *formatstr = NULL;
326 	char *uuidstr = NULL;
327 	char *path_lock = NULL;
328 	char *base_commit_id_str = NULL;
329 	char *head_ref_str = NULL;
330 	int version, fd = -1;
331 	const char *errstr;
332 	struct got_repository *repo = NULL;
333 	uint32_t uuid_status;
334 
335 	*worktree = NULL;
336 
337 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
338 		err = got_error_from_errno();
339 		path_got = NULL;
340 		goto done;
341 	}
342 
343 	if (asprintf(&path_lock, "%s/%s", path_got, GOT_WORKTREE_LOCK) == -1) {
344 		err = got_error_from_errno();
345 		path_lock = NULL;
346 		goto done;
347 	}
348 
349 	fd = open(path_lock, O_RDWR | O_EXLOCK | O_NONBLOCK);
350 	if (fd == -1) {
351 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
352 		    : got_error_from_errno());
353 		goto done;
354 	}
355 
356 	err = read_meta_file(&formatstr, path_got, GOT_WORKTREE_FORMAT);
357 	if (err)
358 		goto done;
359 
360 	version = strtonum(formatstr, 1, INT_MAX, &errstr);
361 	if (errstr) {
362 		err = got_error(GOT_ERR_WORKTREE_META);
363 		goto done;
364 	}
365 	if (version != GOT_WORKTREE_FORMAT_VERSION) {
366 		err = got_error(GOT_ERR_WORKTREE_VERS);
367 		goto done;
368 	}
369 
370 	*worktree = calloc(1, sizeof(**worktree));
371 	if (*worktree == NULL) {
372 		err = got_error_from_errno();
373 		goto done;
374 	}
375 	(*worktree)->lockfd = -1;
376 
377 	(*worktree)->root_path = strdup(path);
378 	if ((*worktree)->root_path == NULL) {
379 		err = got_error_from_errno();
380 		goto done;
381 	}
382 	err = read_meta_file(&(*worktree)->repo_path, path_got,
383 	    GOT_WORKTREE_REPOSITORY);
384 	if (err)
385 		goto done;
386 
387 	err = read_meta_file(&(*worktree)->path_prefix, path_got,
388 	    GOT_WORKTREE_PATH_PREFIX);
389 	if (err)
390 		goto done;
391 
392 	err = read_meta_file(&base_commit_id_str, path_got,
393 	    GOT_WORKTREE_BASE_COMMIT);
394 	if (err)
395 		goto done;
396 
397 	err = read_meta_file(&uuidstr, path_got, GOT_WORKTREE_UUID);
398 	if (err)
399 		goto done;
400 	uuid_from_string(uuidstr, &(*worktree)->uuid, &uuid_status);
401 	if (uuid_status != uuid_s_ok) {
402 		err = got_error_uuid(uuid_status);
403 		goto done;
404 	}
405 
406 	err = got_repo_open(&repo, (*worktree)->repo_path);
407 	if (err)
408 		goto done;
409 
410 	err = got_object_resolve_id_str(&(*worktree)->base_commit_id, repo,
411 	    base_commit_id_str);
412 	if (err)
413 		goto done;
414 
415 	err = read_meta_file(&head_ref_str, path_got, GOT_WORKTREE_HEAD_REF);
416 	if (err)
417 		goto done;
418 
419 	err = got_ref_open(&(*worktree)->head_ref, repo, head_ref_str);
420 done:
421 	if (repo)
422 		got_repo_close(repo);
423 	free(path_got);
424 	free(path_lock);
425 	free(head_ref_str);
426 	free(base_commit_id_str);
427 	free(uuidstr);
428 	free(formatstr);
429 	if (err) {
430 		if (fd != -1)
431 			close(fd);
432 		if (*worktree != NULL)
433 			got_worktree_close(*worktree);
434 		*worktree = NULL;
435 	} else
436 		(*worktree)->lockfd = fd;
437 
438 	return err;
439 }
440 
441 const struct got_error *
442 got_worktree_open(struct got_worktree **worktree, const char *path)
443 {
444 	const struct got_error *err = NULL;
445 
446 	do {
447 		err = open_worktree(worktree, path);
448 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT))
449 			return err;
450 		if (*worktree)
451 			return NULL;
452 		path = dirname(path);
453 		if (path == NULL)
454 			return got_error_from_errno();
455 	} while (!((path[0] == '.' || path[0] == '/') && path[1] == '\0'));
456 
457 	return got_error(GOT_ERR_NOT_WORKTREE);
458 }
459 
460 const struct got_error *
461 got_worktree_close(struct got_worktree *worktree)
462 {
463 	const struct got_error *err = NULL;
464 	free(worktree->root_path);
465 	free(worktree->repo_path);
466 	free(worktree->path_prefix);
467 	free(worktree->base_commit_id);
468 	if (worktree->head_ref)
469 		got_ref_close(worktree->head_ref);
470 	if (worktree->lockfd != -1)
471 		if (close(worktree->lockfd) != 0)
472 			err = got_error_from_errno();
473 	free(worktree);
474 	return err;
475 }
476 
477 const char *
478 got_worktree_get_root_path(struct got_worktree *worktree)
479 {
480 	return worktree->root_path;
481 }
482 
483 const char *
484 got_worktree_get_repo_path(struct got_worktree *worktree)
485 {
486 	return worktree->repo_path;
487 }
488 
489 const char *
490 got_worktree_get_path_prefix(struct got_worktree *worktree)
491 {
492 	return worktree->path_prefix;
493 }
494 
495 const struct got_error *
496 got_worktree_match_path_prefix(int *match, struct got_worktree *worktree,
497     const char *path_prefix)
498 {
499 	char *absprefix = NULL;
500 
501 	if (!got_path_is_absolute(path_prefix)) {
502 		if (asprintf(&absprefix, "/%s", path_prefix) == -1)
503 			return got_error_from_errno();
504 	}
505 	*match = (strcmp(absprefix ? absprefix : path_prefix,
506 	    worktree->path_prefix) == 0);
507 	free(absprefix);
508 	return NULL;
509 }
510 
511 char *
512 got_worktree_get_head_ref_name(struct got_worktree *worktree)
513 {
514 	return got_ref_to_str(worktree->head_ref);
515 }
516 
517 struct got_reference *
518 got_worktree_get_head_ref(struct got_worktree *worktree)
519 {
520 	return got_ref_dup(worktree->head_ref);
521 }
522 
523 struct got_object_id *
524 got_worktree_get_base_commit_id(struct got_worktree *worktree)
525 {
526 	return worktree->base_commit_id;
527 }
528 
529 const struct got_error *
530 got_worktree_set_base_commit_id(struct got_worktree *worktree,
531     struct got_repository *repo, struct got_object_id *commit_id)
532 {
533 	const struct got_error *err;
534 	struct got_object *obj = NULL;
535 	char *id_str = NULL;
536 	char *path_got = NULL;
537 
538 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
539 	    GOT_WORKTREE_GOT_DIR) == -1) {
540 		err = got_error_from_errno();
541 		path_got = NULL;
542 		goto done;
543 	}
544 
545 	err = got_object_open(&obj, repo, commit_id);
546 	if (err)
547 		return err;
548 
549 	if (obj->type != GOT_OBJ_TYPE_COMMIT) {
550 		err = got_error(GOT_ERR_OBJ_TYPE);
551 		goto done;
552 	}
553 
554 	/* Record our base commit. */
555 	err = got_object_id_str(&id_str, commit_id);
556 	if (err)
557 		goto done;
558 	err = update_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, id_str);
559 	if (err)
560 		goto done;
561 
562 	free(worktree->base_commit_id);
563 	worktree->base_commit_id = got_object_id_dup(commit_id);
564 	if (worktree->base_commit_id == NULL) {
565 		err = got_error_from_errno();
566 		goto done;
567 	}
568 done:
569 	if (obj)
570 		got_object_close(obj);
571 	free(id_str);
572 	free(path_got);
573 	return err;
574 }
575 
576 static const struct got_error *
577 lock_worktree(struct got_worktree *worktree, int operation)
578 {
579 	if (flock(worktree->lockfd, operation | LOCK_NB) == -1)
580 		return (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
581 		    : got_error_from_errno());
582 	return NULL;
583 }
584 
585 static const struct got_error *
586 add_dir_on_disk(struct got_worktree *worktree, const char *path)
587 {
588 	const struct got_error *err = NULL;
589 	char *abspath;
590 
591 	if (asprintf(&abspath, "%s/%s", worktree->root_path, path) == -1)
592 		return got_error_from_errno();
593 
594 	err = got_path_mkdir(abspath);
595 	if (err && err->code == GOT_ERR_ERRNO && errno == EEXIST) {
596 		struct stat sb;
597 		err = NULL;
598 		if (lstat(abspath, &sb) == -1) {
599 			err = got_error_from_errno();
600 		} else if (!S_ISDIR(sb.st_mode)) {
601 			/* TODO directory is obstructed; do something */
602 			err = got_error(GOT_ERR_FILE_OBSTRUCTED);
603 		}
604 	}
605 	free(abspath);
606 	return err;
607 }
608 
609 static const struct got_error *
610 check_file_contents_equal(int *same, FILE *f1, FILE *f2)
611 {
612 	const struct got_error *err = NULL;
613 	uint8_t fbuf1[8192];
614 	uint8_t fbuf2[8192];
615 	size_t flen1 = 0, flen2 = 0;
616 
617 	*same = 1;
618 
619 	while (1) {
620 		flen1 = fread(fbuf1, 1, sizeof(fbuf1), f1);
621 		if (flen1 == 0 && ferror(f1)) {
622 			err = got_error_from_errno();
623 			break;
624 		}
625 		flen2 = fread(fbuf2, 1, sizeof(fbuf2), f2);
626 		if (flen2 == 0 && ferror(f2)) {
627 			err = got_error_from_errno();
628 			break;
629 		}
630 		if (flen1 == 0) {
631 			if (flen2 != 0)
632 				*same = 0;
633 			break;
634 		} else if (flen2 == 0) {
635 			if (flen1 != 0)
636 				*same = 0;
637 			break;
638 		} else if (flen1 == flen2) {
639 			if (memcmp(fbuf1, fbuf2, flen2) != 0) {
640 				*same = 0;
641 				break;
642 			}
643 		} else {
644 			*same = 0;
645 			break;
646 		}
647 	}
648 
649 	return err;
650 }
651 
652 static const struct got_error *
653 check_files_equal(int *same, const char *f1_path, const char *f2_path)
654 {
655 	const struct got_error *err = NULL;
656 	struct stat sb;
657 	size_t size1, size2;
658 	FILE *f1 = NULL, *f2 = NULL;
659 
660 	*same = 1;
661 
662 	if (lstat(f1_path, &sb) != 0) {
663 		err = got_error_from_errno();
664 		goto done;
665 	}
666 	size1 = sb.st_size;
667 
668 	if (lstat(f2_path, &sb) != 0) {
669 		err = got_error_from_errno();
670 		goto done;
671 	}
672 	size2 = sb.st_size;
673 
674 	if (size1 != size2) {
675 		*same = 0;
676 		return NULL;
677 	}
678 
679 	f1 = fopen(f1_path, "r");
680 	if (f1 == NULL)
681 		return got_error_from_errno();
682 
683 	f2 = fopen(f2_path, "r");
684 	if (f2 == NULL) {
685 		err = got_error_from_errno();
686 		goto done;
687 	}
688 
689 	err = check_file_contents_equal(same, f1, f2);
690 done:
691 	if (f1 && fclose(f1) != 0 && err == NULL)
692 		err = got_error_from_errno();
693 	if (f2 && fclose(f2) != 0 && err == NULL)
694 		err = got_error_from_errno();
695 
696 	return err;
697 }
698 
699 /*
700  * Perform a 3-way merge where the file's version in the file index (blob2)
701  * acts as the common ancestor, the incoming blob (blob1) acts as the first
702  * derived version, and the file on disk acts as the second derived version.
703  */
704 static const struct got_error *
705 merge_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
706    struct got_fileindex_entry *ie, const char *ondisk_path, const char *path,
707    uint16_t te_mode, uint16_t st_mode, struct got_blob_object *blob1,
708    struct got_repository *repo,
709    got_worktree_checkout_cb progress_cb, void *progress_arg)
710 {
711 	const struct got_error *err = NULL;
712 	int merged_fd = -1;
713 	struct got_blob_object *blob2 = NULL;
714 	FILE *f1 = NULL, *f2 = NULL;
715 	char *blob1_path = NULL, *blob2_path = NULL;
716 	char *merged_path = NULL, *base_path = NULL;
717 	struct got_object_id id2;
718 	char *id_str = NULL;
719 	char *label1 = NULL;
720 	int overlapcnt = 0, update_timestamps = 0;
721 	char *parent;
722 
723 	parent = dirname(ondisk_path);
724 	if (parent == NULL)
725 		return got_error_from_errno();
726 
727 	if (asprintf(&base_path, "%s/got-merged", parent) == -1)
728 		return got_error_from_errno();
729 
730 	err = got_opentemp_named_fd(&merged_path, &merged_fd, base_path);
731 	if (err)
732 		goto done;
733 
734 	free(base_path);
735 	if (asprintf(&base_path, "%s/got-merge-blob1", parent) == -1) {
736 		err = got_error_from_errno();
737 		base_path = NULL;
738 		goto done;
739 	}
740 
741 	err = got_opentemp_named(&blob1_path, &f1, base_path);
742 	if (err)
743 		goto done;
744 	err = got_object_blob_dump_to_file(NULL, NULL, f1, blob1);
745 	if (err)
746 		goto done;
747 
748 	free(base_path);
749 	if (asprintf(&base_path, "%s/got-merge-blob2", parent) == -1) {
750 		err = got_error_from_errno();
751 		base_path = NULL;
752 		goto done;
753 	}
754 
755 	err = got_opentemp_named(&blob2_path, &f2, base_path);
756 	if (err)
757 		goto done;
758 
759 	memcpy(id2.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
760 	err = got_object_open_as_blob(&blob2, repo, &id2, 8192);
761 	if (err)
762 		goto done;
763 	err = got_object_blob_dump_to_file(NULL, NULL, f2, blob2);
764 	if (err)
765 		goto done;
766 
767 	err = got_object_id_str(&id_str, worktree->base_commit_id);
768 	if (err)
769 		goto done;
770 	if (asprintf(&label1, "commit %s", id_str) == -1) {
771 		err = got_error_from_errno();
772 		goto done;
773 	}
774 
775 	err = got_merge_diff3(&overlapcnt, merged_fd, blob1_path,
776 	    blob2_path, ondisk_path, label1, path);
777 	if (err)
778 		goto done;
779 
780 	(*progress_cb)(progress_arg,
781 	    overlapcnt > 0 ? GOT_STATUS_CONFLICT : GOT_STATUS_MERGE, path);
782 
783 
784 	if (fsync(merged_fd) != 0) {
785 		err = got_error_from_errno();
786 		goto done;
787 	}
788 
789 	/* Check if a clean merge has subsumed all local changes. */
790 	if (overlapcnt == 0) {
791 		err = check_files_equal(&update_timestamps, blob1_path,
792 		    merged_path);
793 		if (err)
794 			goto done;
795 	}
796 
797 	if (chmod(merged_path, st_mode) != 0) {
798 		err = got_error_from_errno();
799 		goto done;
800 	}
801 
802 	if (rename(merged_path, ondisk_path) != 0) {
803 		err = got_error_from_errno();
804 		unlink(merged_path);
805 		goto done;
806 	}
807 
808 	/*
809 	 * Do not update timestamps of already modified files. Otherwise,
810 	 * a future status walk would treat them as unmodified files again.
811 	 */
812 	err = got_fileindex_entry_update(ie, ondisk_path,
813 	    blob1->id.sha1, worktree->base_commit_id->sha1, update_timestamps);
814 done:
815 	if (merged_fd != -1 && close(merged_fd) != 0 && err == NULL)
816 		err = got_error_from_errno();
817 	if (f1 && fclose(f1) != 0 && err == NULL)
818 		err = got_error_from_errno();
819 	if (f2 && fclose(f2) != 0 && err == NULL)
820 		err = got_error_from_errno();
821 	if (blob2)
822 		got_object_blob_close(blob2);
823 	free(merged_path);
824 	free(base_path);
825 	if (blob1_path) {
826 		unlink(blob1_path);
827 		free(blob1_path);
828 	}
829 	if (blob2_path) {
830 		unlink(blob2_path);
831 		free(blob2_path);
832 	}
833 	free(id_str);
834 	free(label1);
835 	return err;
836 }
837 
838 static const struct got_error *
839 install_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
840    struct got_fileindex_entry *entry, const char *ondisk_path, const char *path,
841    uint16_t te_mode, uint16_t st_mode, struct got_blob_object *blob,
842    int restoring_missing_file, struct got_repository *repo,
843    got_worktree_checkout_cb progress_cb, void *progress_arg)
844 {
845 	const struct got_error *err = NULL;
846 	int fd = -1;
847 	size_t len, hdrlen;
848 	int update = 0;
849 	char *tmppath = NULL;
850 
851 	fd = open(ondisk_path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
852 	    GOT_DEFAULT_FILE_MODE);
853 	if (fd == -1) {
854 		if (errno == ENOENT) {
855 			char *parent = dirname(path);
856 			if (parent == NULL)
857 				return got_error_from_errno();
858 			err = add_dir_on_disk(worktree, parent);
859 			if (err)
860 				return err;
861 			fd = open(ondisk_path,
862 			    O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
863 			    GOT_DEFAULT_FILE_MODE);
864 			if (fd == -1)
865 				return got_error_from_errno();
866 		} else if (errno == EEXIST) {
867 			if (!S_ISREG(st_mode)) {
868 				/* TODO file is obstructed; do something */
869 				err = got_error(GOT_ERR_FILE_OBSTRUCTED);
870 				goto done;
871 			} else {
872 				err = got_opentemp_named_fd(&tmppath, &fd,
873 				    ondisk_path);
874 				if (err)
875 					goto done;
876 				update = 1;
877 			}
878 		} else
879 			return got_error_from_errno();
880 	}
881 
882 	if (restoring_missing_file)
883 		(*progress_cb)(progress_arg, GOT_STATUS_MISSING, path);
884 	else
885 		(*progress_cb)(progress_arg,
886 		    update ? GOT_STATUS_UPDATE : GOT_STATUS_ADD, path);
887 
888 	hdrlen = got_object_blob_get_hdrlen(blob);
889 	do {
890 		const uint8_t *buf = got_object_blob_get_read_buf(blob);
891 		err = got_object_blob_read_block(&len, blob);
892 		if (err)
893 			break;
894 		if (len > 0) {
895 			/* Skip blob object header first time around. */
896 			ssize_t outlen = write(fd, buf + hdrlen, len - hdrlen);
897 			if (outlen == -1) {
898 				err = got_error_from_errno();
899 				goto done;
900 			} else if (outlen != len - hdrlen) {
901 				err = got_error(GOT_ERR_IO);
902 				goto done;
903 			}
904 			hdrlen = 0;
905 		}
906 	} while (len != 0);
907 
908 	if (fsync(fd) != 0) {
909 		err = got_error_from_errno();
910 		goto done;
911 	}
912 
913 	if (update) {
914 		if (rename(tmppath, ondisk_path) != 0) {
915 			err = got_error_from_errno();
916 			unlink(tmppath);
917 			goto done;
918 		}
919 	}
920 
921 	if (te_mode & S_IXUSR) {
922 		if (chmod(ondisk_path, st_mode | S_IXUSR) == -1) {
923 			err = got_error_from_errno();
924 			goto done;
925 		}
926 	} else {
927 		if (chmod(ondisk_path, st_mode & ~S_IXUSR) == -1) {
928 			err = got_error_from_errno();
929 			goto done;
930 		}
931 	}
932 
933 	if (entry == NULL)
934 		entry = got_fileindex_entry_get(fileindex, path);
935 	if (entry)
936 		err = got_fileindex_entry_update(entry, ondisk_path,
937 		    blob->id.sha1, worktree->base_commit_id->sha1, 1);
938 	else {
939 		err = got_fileindex_entry_alloc(&entry, ondisk_path,
940 		    path, blob->id.sha1, worktree->base_commit_id->sha1);
941 		if (err)
942 			goto done;
943 		err = got_fileindex_entry_add(fileindex, entry);
944 	}
945 done:
946 	if (fd != -1 && close(fd) != 0 && err == NULL)
947 		err = got_error_from_errno();
948 	free(tmppath);
949 	return err;
950 }
951 
952 static const struct got_error *
953 get_file_status(unsigned char *status, struct stat *sb,
954     struct got_fileindex_entry *ie, const char *abspath,
955     struct got_repository *repo)
956 {
957 	const struct got_error *err = NULL;
958 	struct got_object_id id;
959 	size_t hdrlen;
960 	FILE *f = NULL;
961 	uint8_t fbuf[8192];
962 	struct got_blob_object *blob = NULL;
963 	size_t flen, blen;
964 
965 	*status = GOT_STATUS_NO_CHANGE;
966 
967 	if (lstat(abspath, sb) == -1) {
968 		if (errno == ENOENT) {
969 			if (ie) {
970 				if (got_fileindex_entry_has_file_on_disk(ie))
971 					*status = GOT_STATUS_MISSING;
972 				else
973 					*status = GOT_STATUS_DELETE;
974 				sb->st_mode =
975 				    ((ie->mode >> GOT_FILEIDX_MODE_PERMS_SHIFT)
976 				    & (S_IRWXU | S_IRWXG | S_IRWXO));
977 			} else
978 				sb->st_mode = GOT_DEFAULT_FILE_MODE;
979 			return NULL;
980 		}
981 		return got_error_from_errno();
982 	}
983 
984 	if (!S_ISREG(sb->st_mode)) {
985 		*status = GOT_STATUS_OBSTRUCTED;
986 		return NULL;
987 	}
988 
989 	if (ie == NULL)
990 		return NULL;
991 
992 	if (!got_fileindex_entry_has_file_on_disk(ie)) {
993 		*status = GOT_STATUS_DELETE;
994 		return NULL;
995 	} else if (!got_fileindex_entry_has_blob(ie)) {
996 		*status = GOT_STATUS_ADD;
997 		return NULL;
998 	}
999 
1000 	if (ie->ctime_sec == sb->st_ctime &&
1001 	    ie->ctime_nsec == sb->st_ctimensec &&
1002 	    ie->mtime_sec == sb->st_mtime &&
1003 	    ie->mtime_sec == sb->st_mtime &&
1004 	    ie->mtime_nsec == sb->st_mtimensec &&
1005 	    ie->size == (sb->st_size & 0xffffffff))
1006 		return NULL;
1007 
1008 	memcpy(id.sha1, ie->blob_sha1, sizeof(id.sha1));
1009 	err = got_object_open_as_blob(&blob, repo, &id, sizeof(fbuf));
1010 	if (err)
1011 		return err;
1012 
1013 	f = fopen(abspath, "r");
1014 	if (f == NULL) {
1015 		err = got_error_from_errno();
1016 		goto done;
1017 	}
1018 	hdrlen = got_object_blob_get_hdrlen(blob);
1019 	while (1) {
1020 		const uint8_t *bbuf = got_object_blob_get_read_buf(blob);
1021 		err = got_object_blob_read_block(&blen, blob);
1022 		if (err)
1023 			break;
1024 		/* Skip length of blob object header first time around. */
1025 		flen = fread(fbuf, 1, sizeof(fbuf) - hdrlen, f);
1026 		if (flen == 0 && ferror(f)) {
1027 			err = got_error_from_errno();
1028 			break;
1029 		}
1030 		if (blen == 0) {
1031 			if (flen != 0)
1032 				*status = GOT_STATUS_MODIFY;
1033 			break;
1034 		} else if (flen == 0) {
1035 			if (blen != 0)
1036 				*status = GOT_STATUS_MODIFY;
1037 			break;
1038 		} else if (blen - hdrlen == flen) {
1039 			/* Skip blob object header first time around. */
1040 			if (memcmp(bbuf + hdrlen, fbuf, flen) != 0) {
1041 				*status = GOT_STATUS_MODIFY;
1042 				break;
1043 			}
1044 		} else {
1045 			*status = GOT_STATUS_MODIFY;
1046 			break;
1047 		}
1048 		hdrlen = 0;
1049 	}
1050 done:
1051 	if (blob)
1052 		got_object_blob_close(blob);
1053 	if (f)
1054 		fclose(f);
1055 	return err;
1056 }
1057 
1058 static const struct got_error *
1059 update_blob(struct got_worktree *worktree,
1060     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
1061     struct got_tree_entry *te, const char *path,
1062     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1063     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1064 {
1065 	const struct got_error *err = NULL;
1066 	struct got_blob_object *blob = NULL;
1067 	char *ondisk_path;
1068 	unsigned char status = GOT_STATUS_NO_CHANGE;
1069 	struct stat sb;
1070 
1071 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
1072 		return got_error_from_errno();
1073 
1074 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1075 	if (err)
1076 		goto done;
1077 
1078 	if (status == GOT_STATUS_OBSTRUCTED) {
1079 		(*progress_cb)(progress_arg, status, path);
1080 		goto done;
1081 	}
1082 
1083 	if (ie && status != GOT_STATUS_MISSING) {
1084 		if (memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
1085 		    SHA1_DIGEST_LENGTH) == 0) {
1086 			(*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
1087 			    path);
1088 			goto done;
1089 		}
1090 		if (memcmp(ie->blob_sha1,
1091 		    te->id->sha1, SHA1_DIGEST_LENGTH) == 0)
1092 			goto done;
1093 	}
1094 
1095 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
1096 	if (err)
1097 		goto done;
1098 
1099 	if (status == GOT_STATUS_MODIFY)
1100 		err = merge_blob(worktree, fileindex, ie, ondisk_path, path,
1101 		    te->mode, sb.st_mode, blob, repo, progress_cb,
1102 		    progress_arg);
1103 	else
1104 		err = install_blob(worktree, fileindex, ie, ondisk_path, path,
1105 		    te->mode, sb.st_mode, blob, status == GOT_STATUS_MISSING,
1106 		    repo, progress_cb, progress_arg);
1107 
1108 	got_object_blob_close(blob);
1109 done:
1110 	free(ondisk_path);
1111 	return err;
1112 }
1113 
1114 static const struct got_error *
1115 remove_ondisk_file(const char *root_path, const char *path)
1116 {
1117 	const struct got_error *err = NULL;
1118 	char *ondisk_path = NULL;
1119 
1120 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
1121 		return got_error_from_errno();
1122 
1123 	if (unlink(ondisk_path) == -1) {
1124 		if (errno != ENOENT)
1125 			err = got_error_from_errno();
1126 	} else {
1127 		char *parent = dirname(ondisk_path);
1128 		while (parent && strcmp(parent, root_path) != 0) {
1129 			if (rmdir(parent) == -1) {
1130 				if (errno != ENOTEMPTY)
1131 					err = got_error_from_errno();
1132 				break;
1133 			}
1134 			parent = dirname(parent);
1135 		}
1136 	}
1137 	free(ondisk_path);
1138 	return err;
1139 }
1140 
1141 struct diff_cb_arg {
1142     struct got_fileindex *fileindex;
1143     struct got_worktree *worktree;
1144     struct got_repository *repo;
1145     got_worktree_checkout_cb progress_cb;
1146     void *progress_arg;
1147     got_worktree_cancel_cb cancel_cb;
1148     void *cancel_arg;
1149 };
1150 
1151 static const struct got_error *
1152 diff_old_new(void *arg, struct got_fileindex_entry *ie,
1153     struct got_tree_entry *te, const char *parent_path)
1154 {
1155 	struct diff_cb_arg *a = arg;
1156 
1157 	return update_blob(a->worktree, a->fileindex, ie, te,
1158 	    ie->path, a->repo, a->progress_cb, a->progress_arg,
1159 	    a->cancel_cb, a->cancel_arg);
1160 }
1161 
1162 static const struct got_error *
1163 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1164 {
1165 	const struct got_error *err;
1166 	struct diff_cb_arg *a = arg;
1167 
1168 	(*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE, ie->path);
1169 
1170 	err = remove_ondisk_file(a->worktree->root_path, ie->path);
1171 	if (err)
1172 		return err;
1173 	got_fileindex_entry_remove(a->fileindex, ie);
1174 	return NULL;
1175 }
1176 
1177 static const struct got_error *
1178 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
1179 {
1180 	struct diff_cb_arg *a = arg;
1181 	const struct got_error *err;
1182 	char *path;
1183 
1184 	if (asprintf(&path, "%s%s%s", parent_path,
1185 	    parent_path[0] ? "/" : "", te->name)
1186 	    == -1)
1187 		return got_error_from_errno();
1188 
1189 	if (S_ISDIR(te->mode))
1190 		err = add_dir_on_disk(a->worktree, path);
1191 	else
1192 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
1193 		    a->repo, a->progress_cb, a->progress_arg,
1194 		    a->cancel_cb, a->cancel_arg);
1195 
1196 	free(path);
1197 	return err;
1198 }
1199 
1200 const struct got_error *
1201 got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
1202 {
1203 	const struct got_error *err = NULL;
1204 	char *uuidstr = NULL;
1205 	uint32_t uuid_status;
1206 
1207 	*refname = NULL;
1208 
1209 	uuid_to_string(&worktree->uuid, &uuidstr, &uuid_status);
1210 	if (uuid_status != uuid_s_ok)
1211 		return got_error_uuid(uuid_status);
1212 
1213 	if (asprintf(refname, "%s-%s", GOT_WORKTREE_BASE_REF_PREFIX, uuidstr)
1214 	    == -1) {
1215 		err = got_error_from_errno();
1216 		*refname = NULL;
1217 	}
1218 	free(uuidstr);
1219 	return err;
1220 }
1221 
1222 /*
1223  * Prevent Git's garbage collector from deleting our base commit by
1224  * setting a reference to our base commit's ID.
1225  */
1226 static const struct got_error *
1227 ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
1228 {
1229 	const struct got_error *err = NULL;
1230 	struct got_reference *ref = NULL;
1231 	char *refname;
1232 
1233 	err = got_worktree_get_base_ref_name(&refname, worktree);
1234 	if (err)
1235 		return err;
1236 
1237 	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
1238 	if (err)
1239 		goto done;
1240 
1241 	err = got_ref_write(ref, repo);
1242 done:
1243 	free(refname);
1244 	if (ref)
1245 		got_ref_close(ref);
1246 	return err;
1247 }
1248 
1249 
1250 const struct got_error *
1251 got_worktree_checkout_files(struct got_worktree *worktree,
1252     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1253     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1254 {
1255 	const struct got_error *err = NULL, *unlockerr, *checkout_err = NULL;
1256 	struct got_commit_object *commit = NULL;
1257 	struct got_object_id *tree_id = NULL;
1258 	struct got_tree_object *tree = NULL;
1259 	char *fileindex_path = NULL, *new_fileindex_path = NULL;
1260 	struct got_fileindex *fileindex = NULL;
1261 	FILE *index = NULL, *new_index = NULL;
1262 	struct got_fileindex_diff_tree_cb diff_cb;
1263 	struct diff_cb_arg arg;
1264 
1265 	err = lock_worktree(worktree, LOCK_EX);
1266 	if (err)
1267 		return err;
1268 
1269 	fileindex = got_fileindex_alloc();
1270 	if (fileindex == NULL) {
1271 		err = got_error_from_errno();
1272 		goto done;
1273 	}
1274 
1275 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
1276 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1277 		err = got_error_from_errno();
1278 		fileindex_path = NULL;
1279 		goto done;
1280 	}
1281 
1282 	/*
1283 	 * Read the file index.
1284 	 * Checking out files is supposed to be an idempotent operation.
1285 	 * If the on-disk file index is incomplete we will try to complete it.
1286 	 */
1287 	index = fopen(fileindex_path, "rb");
1288 	if (index == NULL) {
1289 		if (errno != ENOENT) {
1290 			err = got_error_from_errno();
1291 			goto done;
1292 		}
1293 	} else {
1294 		err = got_fileindex_read(fileindex, index);
1295 		fclose(index);
1296 		if (err)
1297 			goto done;
1298 	}
1299 
1300 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1301 	    fileindex_path);
1302 	if (err)
1303 		goto done;
1304 
1305 	err = ref_base_commit(worktree, repo);
1306 	if (err)
1307 		goto done;
1308 
1309 	err = got_object_open_as_commit(&commit, repo,
1310 	   worktree->base_commit_id);
1311 	if (err)
1312 		goto done;
1313 
1314 	err = got_object_id_by_path(&tree_id, repo,
1315 	    worktree->base_commit_id, worktree->path_prefix);
1316 	if (err)
1317 		goto done;
1318 
1319 	err = got_object_open_as_tree(&tree, repo, tree_id);
1320 	if (err)
1321 		goto done;
1322 
1323 	diff_cb.diff_old_new = diff_old_new;
1324 	diff_cb.diff_old = diff_old;
1325 	diff_cb.diff_new = diff_new;
1326 	arg.fileindex = fileindex;
1327 	arg.worktree = worktree;
1328 	arg.repo = repo;
1329 	arg.progress_cb = progress_cb;
1330 	arg.progress_arg = progress_arg;
1331 	arg.cancel_cb = cancel_cb;
1332 	arg.cancel_arg = cancel_arg;
1333 	checkout_err = got_fileindex_diff_tree(fileindex, tree, repo,
1334 	    &diff_cb, &arg);
1335 
1336 	/* Try to sync the fileindex back to disk in any case. */
1337 	err = got_fileindex_write(fileindex, new_index);
1338 	if (err)
1339 		goto done;
1340 
1341 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1342 		err = got_error_from_errno();
1343 		unlink(new_fileindex_path);
1344 		goto done;
1345 	}
1346 
1347 	free(new_fileindex_path);
1348 	new_fileindex_path = NULL;
1349 
1350 done:
1351 	if (tree)
1352 		got_object_tree_close(tree);
1353 	if (commit)
1354 		got_object_commit_close(commit);
1355 	if (new_fileindex_path)
1356 		unlink(new_fileindex_path);
1357 	if (new_index)
1358 		fclose(new_index);
1359 	free(new_fileindex_path);
1360 	free(fileindex_path);
1361 	got_fileindex_free(fileindex);
1362 	if (checkout_err)
1363 		err = checkout_err;
1364 	unlockerr = lock_worktree(worktree, LOCK_SH);
1365 	if (unlockerr && err == NULL)
1366 		err = unlockerr;
1367 	return err;
1368 }
1369 
1370 struct diff_dir_cb_arg {
1371     struct got_fileindex *fileindex;
1372     struct got_worktree *worktree;
1373     const char *status_path;
1374     size_t status_path_len;
1375     struct got_repository *repo;
1376     got_worktree_status_cb status_cb;
1377     void *status_arg;
1378     got_worktree_cancel_cb cancel_cb;
1379     void *cancel_arg;
1380 };
1381 
1382 static const struct got_error *
1383 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
1384     got_worktree_status_cb status_cb, void *status_arg,
1385     struct got_repository *repo)
1386 {
1387 	const struct got_error *err = NULL;
1388 	unsigned char status = GOT_STATUS_NO_CHANGE;
1389 	struct stat sb;
1390 	struct got_object_id id;
1391 
1392 	err = get_file_status(&status, &sb, ie, abspath, repo);
1393 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
1394 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1395 		err = (*status_cb)(status_arg, status, ie->path, &id);
1396 	}
1397 	return err;
1398 }
1399 
1400 static const struct got_error *
1401 status_old_new(void *arg, struct got_fileindex_entry *ie,
1402     struct dirent *de, const char *parent_path)
1403 {
1404 	const struct got_error *err = NULL;
1405 	struct diff_dir_cb_arg *a = arg;
1406 	char *abspath;
1407 
1408 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
1409 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
1410 		return NULL;
1411 
1412 	if (parent_path[0]) {
1413 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
1414 		    parent_path, de->d_name) == -1)
1415 			return got_error_from_errno();
1416 	} else {
1417 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
1418 		    de->d_name) == -1)
1419 			return got_error_from_errno();
1420 	}
1421 
1422 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
1423 	    a->repo);
1424 	free(abspath);
1425 	return err;
1426 }
1427 
1428 static const struct got_error *
1429 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1430 {
1431 	struct diff_dir_cb_arg *a = arg;
1432 	struct got_object_id id;
1433 	unsigned char status;
1434 
1435 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
1436 		return NULL;
1437 
1438 	memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1439 	if (got_fileindex_entry_has_file_on_disk(ie))
1440 		status = GOT_STATUS_MISSING;
1441 	else
1442 		status = GOT_STATUS_DELETE;
1443 	return (*a->status_cb)(a->status_arg, status, ie->path, &id);
1444 }
1445 
1446 static const struct got_error *
1447 status_new(void *arg, struct dirent *de, const char *parent_path)
1448 {
1449 	const struct got_error *err = NULL;
1450 	struct diff_dir_cb_arg *a = arg;
1451 	char *path = NULL;
1452 
1453 	if (de->d_type == DT_DIR)
1454 		return NULL;
1455 
1456 	/* XXX ignore symlinks for now */
1457 	if (de->d_type == DT_LNK)
1458 		return NULL;
1459 
1460 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
1461 		return NULL;
1462 
1463 	if (parent_path[0]) {
1464 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
1465 			return got_error_from_errno();
1466 	} else {
1467 		path = de->d_name;
1468 	}
1469 
1470 	err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED, path,
1471 	    NULL);
1472 	if (parent_path[0])
1473 		free(path);
1474 	return err;
1475 }
1476 
1477 const struct got_error *
1478 got_worktree_status(struct got_worktree *worktree, const char *path,
1479     struct got_repository *repo, got_worktree_status_cb status_cb,
1480     void *status_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1481 {
1482 	const struct got_error *err = NULL;
1483 	DIR *workdir = NULL;
1484 	char *fileindex_path = NULL;
1485 	struct got_fileindex *fileindex = NULL;
1486 	FILE *index = NULL;
1487 	struct got_fileindex_diff_dir_cb fdiff_cb;
1488 	struct diff_dir_cb_arg arg;
1489 	char *ondisk_path = NULL;
1490 
1491 	fileindex = got_fileindex_alloc();
1492 	if (fileindex == NULL) {
1493 		err = got_error_from_errno();
1494 		goto done;
1495 	}
1496 
1497 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
1498 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1499 		err = got_error_from_errno();
1500 		fileindex_path = NULL;
1501 		goto done;
1502 	}
1503 
1504 	index = fopen(fileindex_path, "rb");
1505 	if (index == NULL) {
1506 		if (errno != ENOENT) {
1507 			err = got_error_from_errno();
1508 			goto done;
1509 		}
1510 	} else {
1511 		err = got_fileindex_read(fileindex, index);
1512 		fclose(index);
1513 		if (err)
1514 			goto done;
1515 	}
1516 
1517 	if (asprintf(&ondisk_path, "%s%s%s",
1518 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
1519 		err = got_error_from_errno();
1520 		goto done;
1521 	}
1522 	workdir = opendir(ondisk_path);
1523 	if (workdir == NULL) {
1524 		if (errno == ENOTDIR || errno == ENOENT) {
1525 			struct got_fileindex_entry *ie;
1526 			ie = got_fileindex_entry_get(fileindex, path);
1527 			if (ie == NULL) {
1528 				err = got_error(GOT_ERR_BAD_PATH);
1529 				goto done;
1530 			}
1531 			err = report_file_status(ie, ondisk_path,
1532 			    status_cb, status_arg, repo);
1533 			goto done;
1534 		} else {
1535 			err = got_error_from_errno();
1536 			goto done;
1537 		}
1538 	}
1539 	fdiff_cb.diff_old_new = status_old_new;
1540 	fdiff_cb.diff_old = status_old;
1541 	fdiff_cb.diff_new = status_new;
1542 	arg.fileindex = fileindex;
1543 	arg.worktree = worktree;
1544 	arg.status_path = path;
1545 	arg.status_path_len = strlen(path);
1546 	arg.repo = repo;
1547 	arg.status_cb = status_cb;
1548 	arg.status_arg = status_arg;
1549 	arg.cancel_cb = cancel_cb;
1550 	arg.cancel_arg = cancel_arg;
1551 	err = got_fileindex_diff_dir(fileindex, workdir, worktree->root_path,
1552 	    path, repo, &fdiff_cb, &arg);
1553 done:
1554 	if (workdir)
1555 		closedir(workdir);
1556 	free(ondisk_path);
1557 	free(fileindex_path);
1558 	got_fileindex_free(fileindex);
1559 	return err;
1560 }
1561 
1562 const struct got_error *
1563 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
1564     const char *arg)
1565 {
1566 	const struct got_error *err = NULL;
1567 	char *resolved, *path = NULL;
1568 	size_t len;
1569 
1570 	*wt_path = NULL;
1571 
1572 	resolved = realpath(arg, NULL);
1573 	if (resolved == NULL)
1574 		return got_error_from_errno();
1575 
1576 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
1577 	    strlen(got_worktree_get_root_path(worktree)))) {
1578 		err = got_error(GOT_ERR_BAD_PATH);
1579 		goto done;
1580 	}
1581 
1582 	path = strdup(resolved + strlen(got_worktree_get_root_path(worktree)));
1583 	if (path == NULL) {
1584 		err = got_error_from_errno();
1585 		goto done;
1586 	}
1587 
1588 	/* XXX status walk can't deal with trailing slash! */
1589 	len = strlen(path);
1590 	while (path[len - 1] == '/') {
1591 		path[len - 1] = '\0';
1592 		len--;
1593 	}
1594 done:
1595 	free(resolved);
1596 	if (err == NULL)
1597 		*wt_path = path;
1598 	else
1599 		free(path);
1600 	return err;
1601 }
1602 
1603 const struct got_error *
1604 got_worktree_schedule_add(struct got_worktree *worktree,
1605     const char *ondisk_path, got_worktree_status_cb status_cb, void *status_arg,
1606     struct got_repository *repo)
1607 {
1608 	struct got_fileindex *fileindex = NULL;
1609 	struct got_fileindex_entry *ie = NULL;
1610 	char *relpath, *fileindex_path = NULL, *new_fileindex_path = NULL;
1611 	FILE *index = NULL, *new_index = NULL;
1612 	const struct got_error *err = NULL, *unlockerr = NULL;
1613 	int ie_added = 0;
1614 
1615 	err = lock_worktree(worktree, LOCK_EX);
1616 	if (err)
1617 		return err;
1618 
1619 	err = got_path_skip_common_ancestor(&relpath,
1620 	    got_worktree_get_root_path(worktree), ondisk_path);
1621 	if (err)
1622 		goto done;
1623 
1624 	err = got_fileindex_entry_alloc(&ie, ondisk_path, relpath, NULL, NULL);
1625 	if (err)
1626 		goto done;
1627 
1628 	fileindex = got_fileindex_alloc();
1629 	if (fileindex == NULL) {
1630 		err = got_error_from_errno();
1631 		goto done;
1632 	}
1633 
1634 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
1635 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1636 		err = got_error_from_errno();
1637 		fileindex_path = NULL;
1638 		goto done;
1639 	}
1640 
1641 	index = fopen(fileindex_path, "rb");
1642 	if (index == NULL) {
1643 		err = got_error_from_errno();
1644 		goto done;
1645 	}
1646 
1647 	err = got_fileindex_read(fileindex, index);
1648 	if (err)
1649 		goto done;
1650 
1651 	err = got_fileindex_entry_add(fileindex, ie);
1652 	if (err)
1653 		goto done;
1654 	ie_added = 1; /* now owned by fileindex; don't free separately */
1655 
1656 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1657 	    fileindex_path);
1658 	if (err)
1659 		goto done;
1660 
1661 	err = got_fileindex_write(fileindex, new_index);
1662 	if (err)
1663 		goto done;
1664 
1665 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1666 		err = got_error_from_errno();
1667 		goto done;
1668 	}
1669 
1670 	free(new_fileindex_path);
1671 	new_fileindex_path = NULL;
1672 
1673 	err = report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
1674 done:
1675 	if (index) {
1676 		if (fclose(index) != 0 && err == NULL)
1677 			err = got_error_from_errno();
1678 	}
1679 	if (new_fileindex_path) {
1680 		if (unlink(new_fileindex_path) != 0 && err == NULL)
1681 			err = got_error_from_errno();
1682 		free(new_fileindex_path);
1683 	}
1684 	if (!ie_added)
1685 		got_fileindex_entry_free(ie);
1686 	if (fileindex)
1687 		got_fileindex_free(fileindex);
1688 	unlockerr = lock_worktree(worktree, LOCK_SH);
1689 	if (unlockerr && err == NULL)
1690 		err = unlockerr;
1691 	free(relpath);
1692 	return err;
1693 }
1694 
1695 const struct got_error *
1696 got_worktree_schedule_delete(struct got_worktree *worktree,
1697     const char *ondisk_path, int delete_local_mods,
1698     got_worktree_status_cb status_cb, void *status_arg,
1699     struct got_repository *repo)
1700 {
1701 	struct got_fileindex *fileindex = NULL;
1702 	struct got_fileindex_entry *ie = NULL;
1703 	char *relpath, *fileindex_path = NULL, *new_fileindex_path = NULL;
1704 	FILE *index = NULL, *new_index = NULL;
1705 	const struct got_error *err = NULL, *unlockerr = NULL;
1706 	unsigned char status;
1707 	struct stat sb;
1708 
1709 	err = lock_worktree(worktree, LOCK_EX);
1710 	if (err)
1711 		return err;
1712 
1713 	err = got_path_skip_common_ancestor(&relpath,
1714 	    got_worktree_get_root_path(worktree), ondisk_path);
1715 	if (err)
1716 		goto done;
1717 
1718 	fileindex = got_fileindex_alloc();
1719 	if (fileindex == NULL) {
1720 		err = got_error_from_errno();
1721 		goto done;
1722 	}
1723 
1724 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
1725 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1726 		err = got_error_from_errno();
1727 		fileindex_path = NULL;
1728 		goto done;
1729 	}
1730 
1731 	index = fopen(fileindex_path, "rb");
1732 	if (index == NULL) {
1733 		err = got_error_from_errno();
1734 		goto done;
1735 	}
1736 
1737 	err = got_fileindex_read(fileindex, index);
1738 	if (err)
1739 		goto done;
1740 
1741 	ie = got_fileindex_entry_get(fileindex, relpath);
1742 	if (ie == NULL) {
1743 		err = got_error(GOT_ERR_BAD_PATH);
1744 		goto done;
1745 	}
1746 
1747 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1748 	if (err)
1749 		goto done;
1750 
1751 	if (status != GOT_STATUS_NO_CHANGE) {
1752 		if (status != GOT_STATUS_MODIFY) {
1753 			err = got_error(GOT_ERR_FILE_STATUS);
1754 			goto done;
1755 		}
1756 		if (!delete_local_mods) {
1757 			err = got_error(GOT_ERR_FILE_MODIFIED);
1758 			goto done;
1759 		}
1760 	}
1761 
1762 	if (unlink(ondisk_path) != 0) {
1763 		err = got_error_from_errno();
1764 		goto done;
1765 	}
1766 
1767 	got_fileindex_entry_mark_deleted_from_disk(ie);
1768 
1769 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1770 	    fileindex_path);
1771 	if (err)
1772 		goto done;
1773 
1774 	err = got_fileindex_write(fileindex, new_index);
1775 	if (err)
1776 		goto done;
1777 
1778 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1779 		err = got_error_from_errno();
1780 		goto done;
1781 	}
1782 
1783 	free(new_fileindex_path);
1784 	new_fileindex_path = NULL;
1785 
1786 	err = report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
1787 done:
1788 	free(relpath);
1789 	if (index) {
1790 		if (fclose(index) != 0 && err == NULL)
1791 			err = got_error_from_errno();
1792 	}
1793 	if (new_fileindex_path) {
1794 		if (unlink(new_fileindex_path) != 0 && err == NULL)
1795 			err = got_error_from_errno();
1796 		free(new_fileindex_path);
1797 	}
1798 	if (fileindex)
1799 		got_fileindex_free(fileindex);
1800 	unlockerr = lock_worktree(worktree, LOCK_SH);
1801 	if (unlockerr && err == NULL)
1802 		err = unlockerr;
1803 	return err;
1804 }