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 				*status = GOT_STATUS_MISSING;
971 				sb->st_mode =
972 				    ((ie->mode >> GOT_FILEIDX_MODE_PERMS_SHIFT)
973 				    & (S_IRWXU | S_IRWXG | S_IRWXO));
974 			} else
975 				sb->st_mode = GOT_DEFAULT_FILE_MODE;
976 			return NULL;
977 		}
978 		return got_error_from_errno();
979 	}
980 
981 	if (!S_ISREG(sb->st_mode)) {
982 		*status = GOT_STATUS_OBSTRUCTED;
983 		return NULL;
984 	}
985 
986 	if (ie == NULL)
987 		return NULL;
988 
989 	if (ie->ctime_sec == sb->st_ctime &&
990 	    ie->ctime_nsec == sb->st_ctimensec &&
991 	    ie->mtime_sec == sb->st_mtime &&
992 	    ie->mtime_sec == sb->st_mtime &&
993 	    ie->mtime_nsec == sb->st_mtimensec &&
994 	    ie->size == (sb->st_size & 0xffffffff))
995 		return NULL;
996 
997 	memcpy(id.sha1, ie->blob_sha1, sizeof(id.sha1));
998 	err = got_object_open_as_blob(&blob, repo, &id, sizeof(fbuf));
999 	if (err)
1000 		return err;
1001 
1002 	f = fopen(abspath, "r");
1003 	if (f == NULL) {
1004 		err = got_error_from_errno();
1005 		goto done;
1006 	}
1007 	hdrlen = got_object_blob_get_hdrlen(blob);
1008 	while (1) {
1009 		const uint8_t *bbuf = got_object_blob_get_read_buf(blob);
1010 		err = got_object_blob_read_block(&blen, blob);
1011 		if (err)
1012 			break;
1013 		/* Skip length of blob object header first time around. */
1014 		flen = fread(fbuf, 1, sizeof(fbuf) - hdrlen, f);
1015 		if (flen == 0 && ferror(f)) {
1016 			err = got_error_from_errno();
1017 			break;
1018 		}
1019 		if (blen == 0) {
1020 			if (flen != 0)
1021 				*status = GOT_STATUS_MODIFY;
1022 			break;
1023 		} else if (flen == 0) {
1024 			if (blen != 0)
1025 				*status = GOT_STATUS_MODIFY;
1026 			break;
1027 		} else if (blen - hdrlen == flen) {
1028 			/* Skip blob object header first time around. */
1029 			if (memcmp(bbuf + hdrlen, fbuf, flen) != 0) {
1030 				*status = GOT_STATUS_MODIFY;
1031 				break;
1032 			}
1033 		} else {
1034 			*status = GOT_STATUS_MODIFY;
1035 			break;
1036 		}
1037 		hdrlen = 0;
1038 	}
1039 done:
1040 	if (blob)
1041 		got_object_blob_close(blob);
1042 	if (f)
1043 		fclose(f);
1044 	return err;
1045 }
1046 
1047 static const struct got_error *
1048 update_blob(struct got_worktree *worktree,
1049     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
1050     struct got_tree_entry *te, const char *path,
1051     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1052     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1053 {
1054 	const struct got_error *err = NULL;
1055 	struct got_blob_object *blob = NULL;
1056 	char *ondisk_path;
1057 	unsigned char status = GOT_STATUS_NO_CHANGE;
1058 	struct stat sb;
1059 
1060 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
1061 		return got_error_from_errno();
1062 
1063 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1064 	if (err)
1065 		goto done;
1066 
1067 	if (status == GOT_STATUS_OBSTRUCTED) {
1068 		(*progress_cb)(progress_arg, status, path);
1069 		goto done;
1070 	}
1071 
1072 	if (ie && status != GOT_STATUS_MISSING) {
1073 		if (memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
1074 		    SHA1_DIGEST_LENGTH) == 0) {
1075 			(*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
1076 			    path);
1077 			goto done;
1078 		}
1079 		if (memcmp(ie->blob_sha1,
1080 		    te->id->sha1, SHA1_DIGEST_LENGTH) == 0)
1081 			goto done;
1082 	}
1083 
1084 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
1085 	if (err)
1086 		goto done;
1087 
1088 	if (status == GOT_STATUS_MODIFY)
1089 		err = merge_blob(worktree, fileindex, ie, ondisk_path, path,
1090 		    te->mode, sb.st_mode, blob, repo, progress_cb,
1091 		    progress_arg);
1092 	else
1093 		err = install_blob(worktree, fileindex, ie, ondisk_path, path,
1094 		    te->mode, sb.st_mode, blob, status == GOT_STATUS_MISSING,
1095 		    repo, progress_cb, progress_arg);
1096 
1097 	got_object_blob_close(blob);
1098 done:
1099 	free(ondisk_path);
1100 	return err;
1101 }
1102 
1103 static const struct got_error *
1104 remove_ondisk_file(const char *root_path, const char *path)
1105 {
1106 	const struct got_error *err = NULL;
1107 	char *ondisk_path = NULL;
1108 
1109 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
1110 		return got_error_from_errno();
1111 
1112 	if (unlink(ondisk_path) == -1) {
1113 		if (errno != ENOENT)
1114 			err = got_error_from_errno();
1115 	} else {
1116 		char *parent = dirname(ondisk_path);
1117 		while (parent && strcmp(parent, root_path) != 0) {
1118 			if (rmdir(parent) == -1) {
1119 				if (errno != ENOTEMPTY)
1120 					err = got_error_from_errno();
1121 				break;
1122 			}
1123 			parent = dirname(parent);
1124 		}
1125 	}
1126 	free(ondisk_path);
1127 	return err;
1128 }
1129 
1130 struct diff_cb_arg {
1131     struct got_fileindex *fileindex;
1132     struct got_worktree *worktree;
1133     struct got_repository *repo;
1134     got_worktree_checkout_cb progress_cb;
1135     void *progress_arg;
1136     got_worktree_cancel_cb cancel_cb;
1137     void *cancel_arg;
1138 };
1139 
1140 static const struct got_error *
1141 diff_old_new(void *arg, struct got_fileindex_entry *ie,
1142     struct got_tree_entry *te, const char *parent_path)
1143 {
1144 	struct diff_cb_arg *a = arg;
1145 
1146 	return update_blob(a->worktree, a->fileindex, ie, te,
1147 	    ie->path, a->repo, a->progress_cb, a->progress_arg,
1148 	    a->cancel_cb, a->cancel_arg);
1149 }
1150 
1151 static const struct got_error *
1152 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1153 {
1154 	const struct got_error *err;
1155 	struct diff_cb_arg *a = arg;
1156 
1157 	(*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE, ie->path);
1158 
1159 	err = remove_ondisk_file(a->worktree->root_path, ie->path);
1160 	if (err)
1161 		return err;
1162 	got_fileindex_entry_remove(a->fileindex, ie);
1163 	return NULL;
1164 }
1165 
1166 static const struct got_error *
1167 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
1168 {
1169 	struct diff_cb_arg *a = arg;
1170 	const struct got_error *err;
1171 	char *path;
1172 
1173 	if (asprintf(&path, "%s%s%s", parent_path,
1174 	    parent_path[0] ? "/" : "", te->name)
1175 	    == -1)
1176 		return got_error_from_errno();
1177 
1178 	if (S_ISDIR(te->mode))
1179 		err = add_dir_on_disk(a->worktree, path);
1180 	else
1181 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
1182 		    a->repo, a->progress_cb, a->progress_arg,
1183 		    a->cancel_cb, a->cancel_arg);
1184 
1185 	free(path);
1186 	return err;
1187 }
1188 
1189 const struct got_error *
1190 got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
1191 {
1192 	const struct got_error *err = NULL;
1193 	char *uuidstr = NULL;
1194 	uint32_t uuid_status;
1195 
1196 	*refname = NULL;
1197 
1198 	uuid_to_string(&worktree->uuid, &uuidstr, &uuid_status);
1199 	if (uuid_status != uuid_s_ok)
1200 		return got_error_uuid(uuid_status);
1201 
1202 	if (asprintf(refname, "%s-%s", GOT_WORKTREE_BASE_REF_PREFIX, uuidstr)
1203 	    == -1) {
1204 		err = got_error_from_errno();
1205 		*refname = NULL;
1206 	}
1207 	free(uuidstr);
1208 	return err;
1209 }
1210 
1211 /*
1212  * Prevent Git's garbage collector from deleting our base commit by
1213  * setting a reference to our base commit's ID.
1214  */
1215 static const struct got_error *
1216 ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
1217 {
1218 	const struct got_error *err = NULL;
1219 	struct got_reference *ref = NULL;
1220 	char *refname;
1221 
1222 	err = got_worktree_get_base_ref_name(&refname, worktree);
1223 	if (err)
1224 		return err;
1225 
1226 	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
1227 	if (err)
1228 		goto done;
1229 
1230 	err = got_ref_write(ref, repo);
1231 done:
1232 	free(refname);
1233 	if (ref)
1234 		got_ref_close(ref);
1235 	return err;
1236 }
1237 
1238 
1239 const struct got_error *
1240 got_worktree_checkout_files(struct got_worktree *worktree,
1241     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1242     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1243 {
1244 	const struct got_error *err = NULL, *unlockerr, *checkout_err = NULL;
1245 	struct got_commit_object *commit = NULL;
1246 	struct got_object_id *tree_id = NULL;
1247 	struct got_tree_object *tree = NULL;
1248 	char *fileindex_path = NULL, *new_fileindex_path = NULL;
1249 	struct got_fileindex *fileindex = NULL;
1250 	FILE *index = NULL, *new_index = NULL;
1251 	struct got_fileindex_diff_tree_cb diff_cb;
1252 	struct diff_cb_arg arg;
1253 
1254 	err = lock_worktree(worktree, LOCK_EX);
1255 	if (err)
1256 		return err;
1257 
1258 	fileindex = got_fileindex_alloc();
1259 	if (fileindex == NULL) {
1260 		err = got_error_from_errno();
1261 		goto done;
1262 	}
1263 
1264 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
1265 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1266 		err = got_error_from_errno();
1267 		fileindex_path = NULL;
1268 		goto done;
1269 	}
1270 
1271 	/*
1272 	 * Read the file index.
1273 	 * Checking out files is supposed to be an idempotent operation.
1274 	 * If the on-disk file index is incomplete we will try to complete it.
1275 	 */
1276 	index = fopen(fileindex_path, "rb");
1277 	if (index == NULL) {
1278 		if (errno != ENOENT) {
1279 			err = got_error_from_errno();
1280 			goto done;
1281 		}
1282 	} else {
1283 		err = got_fileindex_read(fileindex, index);
1284 		fclose(index);
1285 		if (err)
1286 			goto done;
1287 	}
1288 
1289 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1290 	    fileindex_path);
1291 	if (err)
1292 		goto done;
1293 
1294 	err = ref_base_commit(worktree, repo);
1295 	if (err)
1296 		goto done;
1297 
1298 	err = got_object_open_as_commit(&commit, repo,
1299 	   worktree->base_commit_id);
1300 	if (err)
1301 		goto done;
1302 
1303 	err = got_object_id_by_path(&tree_id, repo,
1304 	    worktree->base_commit_id, worktree->path_prefix);
1305 	if (err)
1306 		goto done;
1307 
1308 	err = got_object_open_as_tree(&tree, repo, tree_id);
1309 	if (err)
1310 		goto done;
1311 
1312 	diff_cb.diff_old_new = diff_old_new;
1313 	diff_cb.diff_old = diff_old;
1314 	diff_cb.diff_new = diff_new;
1315 	arg.fileindex = fileindex;
1316 	arg.worktree = worktree;
1317 	arg.repo = repo;
1318 	arg.progress_cb = progress_cb;
1319 	arg.progress_arg = progress_arg;
1320 	arg.cancel_cb = cancel_cb;
1321 	arg.cancel_arg = cancel_arg;
1322 	checkout_err = got_fileindex_diff_tree(fileindex, tree, repo,
1323 	    &diff_cb, &arg);
1324 
1325 	/* Try to sync the fileindex back to disk in any case. */
1326 	err = got_fileindex_write(fileindex, new_index);
1327 	if (err)
1328 		goto done;
1329 
1330 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1331 		err = got_error_from_errno();
1332 		unlink(new_fileindex_path);
1333 		goto done;
1334 	}
1335 
1336 	free(new_fileindex_path);
1337 	new_fileindex_path = NULL;
1338 
1339 done:
1340 	if (tree)
1341 		got_object_tree_close(tree);
1342 	if (commit)
1343 		got_object_commit_close(commit);
1344 	if (new_fileindex_path)
1345 		unlink(new_fileindex_path);
1346 	if (new_index)
1347 		fclose(new_index);
1348 	free(new_fileindex_path);
1349 	free(fileindex_path);
1350 	got_fileindex_free(fileindex);
1351 	if (checkout_err)
1352 		err = checkout_err;
1353 	unlockerr = lock_worktree(worktree, LOCK_SH);
1354 	if (unlockerr && err == NULL)
1355 		err = unlockerr;
1356 	return err;
1357 }
1358 
1359 struct diff_dir_cb_arg {
1360     struct got_fileindex *fileindex;
1361     struct got_worktree *worktree;
1362     const char *status_path;
1363     size_t status_path_len;
1364     struct got_repository *repo;
1365     got_worktree_status_cb status_cb;
1366     void *status_arg;
1367     got_worktree_cancel_cb cancel_cb;
1368     void *cancel_arg;
1369 };
1370 
1371 static const struct got_error *
1372 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
1373     got_worktree_status_cb status_cb, void *status_arg,
1374     struct got_repository *repo)
1375 {
1376 	const struct got_error *err = NULL;
1377 	unsigned char status = GOT_STATUS_NO_CHANGE;
1378 	struct stat sb;
1379 	struct got_object_id id;
1380 
1381 	err = get_file_status(&status, &sb, ie, abspath, repo);
1382 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
1383 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1384 		err = (*status_cb)(status_arg, status, ie->path, &id);
1385 	}
1386 	return err;
1387 }
1388 
1389 static const struct got_error *
1390 status_old_new(void *arg, struct got_fileindex_entry *ie,
1391     struct dirent *de, const char *parent_path)
1392 {
1393 	const struct got_error *err = NULL;
1394 	struct diff_dir_cb_arg *a = arg;
1395 	char *abspath;
1396 
1397 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
1398 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
1399 		return NULL;
1400 
1401 	if (parent_path[0]) {
1402 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
1403 		    parent_path, de->d_name) == -1)
1404 			return got_error_from_errno();
1405 	} else {
1406 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
1407 		    de->d_name) == -1)
1408 			return got_error_from_errno();
1409 	}
1410 
1411 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
1412 	    a->repo);
1413 	free(abspath);
1414 	return err;
1415 }
1416 
1417 static const struct got_error *
1418 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1419 {
1420 	struct diff_dir_cb_arg *a = arg;
1421 	struct got_object_id id;
1422 
1423 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
1424 		return NULL;
1425 
1426 	memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1427 	return (*a->status_cb)(a->status_arg, GOT_STATUS_MISSING, ie->path,
1428 	    &id);
1429 }
1430 
1431 static const struct got_error *
1432 status_new(void *arg, struct dirent *de, const char *parent_path)
1433 {
1434 	const struct got_error *err = NULL;
1435 	struct diff_dir_cb_arg *a = arg;
1436 	char *path = NULL;
1437 
1438 	if (de->d_type == DT_DIR)
1439 		return NULL;
1440 
1441 	/* XXX ignore symlinks for now */
1442 	if (de->d_type == DT_LNK)
1443 		return NULL;
1444 
1445 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
1446 		return NULL;
1447 
1448 	if (parent_path[0]) {
1449 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
1450 			return got_error_from_errno();
1451 	} else {
1452 		path = de->d_name;
1453 	}
1454 
1455 	err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED, path,
1456 	    NULL);
1457 	if (parent_path[0])
1458 		free(path);
1459 	return err;
1460 }
1461 
1462 const struct got_error *
1463 got_worktree_status(struct got_worktree *worktree, const char *path,
1464     struct got_repository *repo, got_worktree_status_cb status_cb,
1465     void *status_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1466 {
1467 	const struct got_error *err = NULL;
1468 	DIR *workdir = NULL;
1469 	char *fileindex_path = NULL;
1470 	struct got_fileindex *fileindex = NULL;
1471 	FILE *index = NULL;
1472 	struct got_fileindex_diff_dir_cb fdiff_cb;
1473 	struct diff_dir_cb_arg arg;
1474 	char *ondisk_path = NULL;
1475 
1476 	fileindex = got_fileindex_alloc();
1477 	if (fileindex == NULL) {
1478 		err = got_error_from_errno();
1479 		goto done;
1480 	}
1481 
1482 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
1483 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1484 		err = got_error_from_errno();
1485 		fileindex_path = NULL;
1486 		goto done;
1487 	}
1488 
1489 	index = fopen(fileindex_path, "rb");
1490 	if (index == NULL) {
1491 		if (errno != ENOENT) {
1492 			err = got_error_from_errno();
1493 			goto done;
1494 		}
1495 	} else {
1496 		err = got_fileindex_read(fileindex, index);
1497 		fclose(index);
1498 		if (err)
1499 			goto done;
1500 	}
1501 
1502 	if (asprintf(&ondisk_path, "%s%s%s",
1503 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
1504 		err = got_error_from_errno();
1505 		goto done;
1506 	}
1507 	workdir = opendir(ondisk_path);
1508 	if (workdir == NULL) {
1509 		if (errno == ENOTDIR) {
1510 			struct got_fileindex_entry *ie;
1511 			ie = got_fileindex_entry_get(fileindex, path);
1512 			if (ie == NULL) {
1513 				err = got_error(GOT_ERR_BAD_PATH);
1514 				goto done;
1515 			}
1516 			err = report_file_status(ie, ondisk_path,
1517 			    status_cb, status_arg, repo);
1518 			goto done;
1519 		} else {
1520 			err = got_error_from_errno();
1521 			goto done;
1522 		}
1523 	}
1524 	fdiff_cb.diff_old_new = status_old_new;
1525 	fdiff_cb.diff_old = status_old;
1526 	fdiff_cb.diff_new = status_new;
1527 	arg.fileindex = fileindex;
1528 	arg.worktree = worktree;
1529 	arg.status_path = path;
1530 	arg.status_path_len = strlen(path);
1531 	arg.repo = repo;
1532 	arg.status_cb = status_cb;
1533 	arg.status_arg = status_arg;
1534 	arg.cancel_cb = cancel_cb;
1535 	arg.cancel_arg = cancel_arg;
1536 	err = got_fileindex_diff_dir(fileindex, workdir, worktree->root_path,
1537 	    path, repo, &fdiff_cb, &arg);
1538 done:
1539 	if (workdir)
1540 		closedir(workdir);
1541 	free(ondisk_path);
1542 	free(fileindex_path);
1543 	got_fileindex_free(fileindex);
1544 	return err;
1545 }
1546 
1547 const struct got_error *
1548 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
1549     const char *arg)
1550 {
1551 	const struct got_error *err = NULL;
1552 	char *resolved, *path = NULL;
1553 	size_t len;
1554 
1555 	*wt_path = NULL;
1556 
1557 	resolved = realpath(arg, NULL);
1558 	if (resolved == NULL)
1559 		return got_error_from_errno();
1560 
1561 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
1562 	    strlen(got_worktree_get_root_path(worktree)))) {
1563 		err = got_error(GOT_ERR_BAD_PATH);
1564 		goto done;
1565 	}
1566 
1567 	path = strdup(resolved + strlen(got_worktree_get_root_path(worktree)));
1568 	if (path == NULL) {
1569 		err = got_error_from_errno();
1570 		goto done;
1571 	}
1572 
1573 	/* XXX status walk can't deal with trailing slash! */
1574 	len = strlen(path);
1575 	while (path[len - 1] == '/') {
1576 		path[len - 1] = '\0';
1577 		len--;
1578 	}
1579 done:
1580 	free(resolved);
1581 	if (err == NULL)
1582 		*wt_path = path;
1583 	else
1584 		free(path);
1585 	return err;
1586 }