1 /*
2  * Copyright (c) 2018 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 
21 #include <string.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <fcntl.h>
25 #include <errno.h>
26 #include <unistd.h>
27 #include <sha1.h>
28 #include <zlib.h>
29 #include <fnmatch.h>
30 
31 #include "got_error.h"
32 #include "got_repository.h"
33 #include "got_reference.h"
34 #include "got_object.h"
35 #include "got_worktree.h"
36 #include "got_opentemp.h"
37 
38 #include "got_lib_worktree.h"
39 #include "got_lib_path.h"
40 #include "got_lib_sha1.h"
41 #include "got_lib_fileindex.h"
42 #include "got_lib_inflate.h"
43 #include "got_lib_delta.h"
44 #include "got_lib_object.h"
45 
46 #ifndef MIN
47 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
48 #endif
49 
50 static const struct got_error *
51 create_meta_file(const char *path_got, const char *name, const char *content)
52 {
53 	const struct got_error *err = NULL;
54 	char *path;
55 	int fd = -1;
56 
57 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
58 		err = got_error_from_errno();
59 		path = NULL;
60 		goto done;
61 	}
62 
63 	fd = open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
64 	    GOT_DEFAULT_FILE_MODE);
65 	if (fd == -1) {
66 		err = got_error_from_errno();
67 		goto done;
68 	}
69 
70 	if (content) {
71 		int len = dprintf(fd, "%s\n", content);
72 		if (len != strlen(content) + 1) {
73 			err = got_error_from_errno();
74 			goto done;
75 		}
76 	}
77 
78 done:
79 	if (fd != -1 && close(fd) == -1 && err == NULL)
80 		err = got_error_from_errno();
81 	free(path);
82 	return err;
83 }
84 
85 static const struct got_error *
86 update_meta_file(const char *path_got, const char *name, const char *content)
87 {
88 	const struct got_error *err = NULL;
89 	FILE *tmpfile = NULL;
90 	char *tmppath = NULL;
91 	char *path = NULL;
92 
93 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
94 		err = got_error_from_errno();
95 		path = NULL;
96 		goto done;
97 	}
98 
99 	err = got_opentemp_named(&tmppath, &tmpfile, path);
100 	if (err)
101 		goto done;
102 
103 	if (content) {
104 		int len = fprintf(tmpfile, "%s\n", content);
105 		if (len != strlen(content) + 1) {
106 			err = got_error_from_errno();
107 			goto done;
108 		}
109 	}
110 
111 	if (rename(tmppath, path) != 0) {
112 		err = got_error_from_errno();
113 		goto done;
114 	}
115 
116 done:
117 	free(tmppath);
118 	fclose(tmpfile);
119 	return err;
120 }
121 
122 static const struct got_error *
123 read_meta_file(char **content, const char *path_got, const char *name)
124 {
125 	const struct got_error *err = NULL;
126 	char *path;
127 	int fd = -1;
128 	ssize_t n;
129 	struct stat sb;
130 
131 	*content = NULL;
132 
133 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
134 		err = got_error_from_errno();
135 		path = NULL;
136 		goto done;
137 	}
138 
139 	fd = open(path, O_RDONLY | O_NOFOLLOW);
140 	if (fd == -1) {
141 		err = got_error_from_errno();
142 		goto done;
143 	}
144 	if (flock(fd, LOCK_SH | LOCK_NB) == -1) {
145 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
146 		    : got_error_from_errno());
147 		goto done;
148 	}
149 
150 	stat(path, &sb);
151 	*content = calloc(1, sb.st_size);
152 	if (*content == NULL) {
153 		err = got_error_from_errno();
154 		goto done;
155 	}
156 
157 	n = read(fd, *content, sb.st_size);
158 	if (n != sb.st_size) {
159 		err = (n == -1 ? got_error_from_errno() :
160 		    got_error(GOT_ERR_WORKTREE_META));
161 		goto done;
162 	}
163 	if ((*content)[sb.st_size - 1] != '\n') {
164 		err = got_error(GOT_ERR_WORKTREE_META);
165 		goto done;
166 	}
167 	(*content)[sb.st_size - 1] = '\0';
168 
169 done:
170 	if (fd != -1 && close(fd) == -1 && err == NULL)
171 		err = got_error_from_errno();
172 	free(path);
173 	if (err) {
174 		free(*content);
175 		*content = NULL;
176 	}
177 	return err;
178 }
179 
180 const struct got_error *
181 got_worktree_init(const char *path, struct got_reference *head_ref,
182     const char *prefix, struct got_repository *repo)
183 {
184 	const struct got_error *err = NULL;
185 	struct got_object_id *commit_id = NULL;
186 	int obj_type;
187 	char *path_got = NULL;
188 	char *refstr = NULL;
189 	char *repo_path = NULL;
190 	char *formatstr = NULL;
191 	char *absprefix = NULL;
192 	char *basestr = NULL;
193 
194 	err = got_ref_resolve(&commit_id, repo, head_ref);
195 	if (err)
196 		return err;
197 	err = got_object_get_type(&obj_type, repo, commit_id);
198 	if (err)
199 		return err;
200 	if (obj_type != GOT_OBJ_TYPE_COMMIT)
201 		return got_error(GOT_ERR_OBJ_TYPE);
202 
203 	if (!got_path_is_absolute(prefix)) {
204 		if (asprintf(&absprefix, "/%s", prefix) == -1)
205 			return got_error_from_errno();
206 	}
207 
208 	/* Create top-level directory (may already exist). */
209 	if (mkdir(path, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
210 		err = got_error_from_errno();
211 		goto done;
212 	}
213 
214 	/* Create .got directory (may already exist). */
215 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
216 		err = got_error_from_errno();
217 		goto done;
218 	}
219 	if (mkdir(path_got, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
220 		err = got_error_from_errno();
221 		goto done;
222 	}
223 
224 	/* Create an empty lock file. */
225 	err = create_meta_file(path_got, GOT_WORKTREE_LOCK, NULL);
226 	if (err)
227 		goto done;
228 
229 	/* Create an empty file index. */
230 	err = create_meta_file(path_got, GOT_WORKTREE_FILE_INDEX, NULL);
231 	if (err)
232 		goto done;
233 
234 	/* Write the HEAD reference. */
235 	refstr = got_ref_to_str(head_ref);
236 	if (refstr == NULL) {
237 		err = got_error_from_errno();
238 		goto done;
239 	}
240 	err = create_meta_file(path_got, GOT_WORKTREE_HEAD_REF, refstr);
241 	if (err)
242 		goto done;
243 
244 	/* Record our base commit. */
245 	err = got_object_id_str(&basestr, commit_id);
246 	if (err)
247 		goto done;
248 	err = create_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, basestr);
249 	if (err)
250 		goto done;
251 
252 	/* Store path to repository. */
253 	repo_path = got_repo_get_path(repo);
254 	if (repo_path == NULL) {
255 		err = got_error_from_errno();
256 		goto done;
257 	}
258 	err = create_meta_file(path_got, GOT_WORKTREE_REPOSITORY, repo_path);
259 	if (err)
260 		goto done;
261 
262 	/* Store in-repository path prefix. */
263 	err = create_meta_file(path_got, GOT_WORKTREE_PATH_PREFIX,
264 	    absprefix ? absprefix : prefix);
265 	if (err)
266 		goto done;
267 
268 	/* Stamp work tree with format file. */
269 	if (asprintf(&formatstr, "%d", GOT_WORKTREE_FORMAT_VERSION) == -1) {
270 		err = got_error_from_errno();
271 		goto done;
272 	}
273 	err = create_meta_file(path_got, GOT_WORKTREE_FORMAT, formatstr);
274 	if (err)
275 		goto done;
276 
277 done:
278 	free(commit_id);
279 	free(path_got);
280 	free(formatstr);
281 	free(refstr);
282 	free(repo_path);
283 	free(absprefix);
284 	free(basestr);
285 	return err;
286 }
287 
288 const struct got_error *
289 got_worktree_open(struct got_worktree **worktree, const char *path)
290 {
291 	const struct got_error *err = NULL;
292 	char *path_got;
293 	char *formatstr = NULL;
294 	char *path_lock = NULL;
295 	char *base_commit_id_str = NULL;
296 	char *head_ref_str = NULL;
297 	int version, fd = -1;
298 	const char *errstr;
299 	struct got_repository *repo = NULL;
300 
301 	*worktree = NULL;
302 
303 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
304 		err = got_error_from_errno();
305 		path_got = NULL;
306 		goto done;
307 	}
308 
309 	if (asprintf(&path_lock, "%s/%s", path_got, GOT_WORKTREE_LOCK) == -1) {
310 		err = got_error_from_errno();
311 		path_lock = NULL;
312 		goto done;
313 	}
314 
315 	fd = open(path_lock, O_RDWR | O_EXLOCK | O_NONBLOCK);
316 	if (fd == -1) {
317 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
318 		    : got_error_from_errno());
319 		goto done;
320 	}
321 
322 	err = read_meta_file(&formatstr, path_got, GOT_WORKTREE_FORMAT);
323 	if (err)
324 		goto done;
325 
326 	version = strtonum(formatstr, 1, INT_MAX, &errstr);
327 	if (errstr) {
328 		err = got_error(GOT_ERR_WORKTREE_META);
329 		goto done;
330 	}
331 	if (version != GOT_WORKTREE_FORMAT_VERSION) {
332 		err = got_error(GOT_ERR_WORKTREE_VERS);
333 		goto done;
334 	}
335 
336 	*worktree = calloc(1, sizeof(**worktree));
337 	if (*worktree == NULL) {
338 		err = got_error_from_errno();
339 		goto done;
340 	}
341 	(*worktree)->lockfd = -1;
342 
343 	(*worktree)->root_path = strdup(path);
344 	if ((*worktree)->root_path == NULL) {
345 		err = got_error_from_errno();
346 		goto done;
347 	}
348 	err = read_meta_file(&(*worktree)->repo_path, path_got,
349 	    GOT_WORKTREE_REPOSITORY);
350 	if (err)
351 		goto done;
352 
353 	err = read_meta_file(&(*worktree)->path_prefix, path_got,
354 	    GOT_WORKTREE_PATH_PREFIX);
355 	if (err)
356 		goto done;
357 
358 	err = read_meta_file(&base_commit_id_str, path_got,
359 	    GOT_WORKTREE_BASE_COMMIT);
360 	if (err)
361 		goto done;
362 
363 	err = got_repo_open(&repo, (*worktree)->repo_path);
364 	if (err)
365 		goto done;
366 
367 	err = got_object_resolve_id_str(&(*worktree)->base_commit_id, repo,
368 	    base_commit_id_str);
369 	if (err)
370 		goto done;
371 
372 	err = read_meta_file(&head_ref_str, path_got, GOT_WORKTREE_HEAD_REF);
373 	if (err)
374 		goto done;
375 
376 	err = got_ref_open(&(*worktree)->head_ref, repo, head_ref_str);
377 done:
378 	if (repo)
379 		got_repo_close(repo);
380 	free(path_got);
381 	free(path_lock);
382 	free(head_ref_str);
383 	free(base_commit_id_str);
384 	if (err) {
385 		if (fd != -1)
386 			close(fd);
387 		if (*worktree != NULL)
388 			got_worktree_close(*worktree);
389 		*worktree = NULL;
390 	} else
391 		(*worktree)->lockfd = fd;
392 
393 	return err;
394 }
395 
396 void
397 got_worktree_close(struct got_worktree *worktree)
398 {
399 	free(worktree->root_path);
400 	free(worktree->repo_path);
401 	free(worktree->path_prefix);
402 	free(worktree->base_commit_id);
403 	if (worktree->head_ref)
404 		got_ref_close(worktree->head_ref);
405 	if (worktree->lockfd != -1)
406 		close(worktree->lockfd);
407 	free(worktree);
408 }
409 
410 const char *
411 got_worktree_get_repo_path(struct got_worktree *worktree)
412 {
413 	return worktree->repo_path;
414 }
415 
416 const char *
417 got_worktree_get_path_prefix(struct got_worktree *worktree)
418 {
419 	return worktree->path_prefix;
420 }
421 
422 const struct got_error *
423 got_worktree_match_path_prefix(int *match, struct got_worktree *worktree,
424     const char *path_prefix)
425 {
426 	char *absprefix = NULL;
427 
428 	if (!got_path_is_absolute(path_prefix)) {
429 		if (asprintf(&absprefix, "/%s", path_prefix) == -1)
430 			return got_error_from_errno();
431 	}
432 	*match = (strcmp(absprefix ? absprefix : path_prefix,
433 	    worktree->path_prefix) == 0);
434 	free(absprefix);
435 	return NULL;
436 }
437 
438 char *
439 got_worktree_get_head_ref_name(struct got_worktree *worktree)
440 {
441 	return got_ref_to_str(worktree->head_ref);
442 }
443 
444 struct got_reference *
445 got_worktree_get_head_ref(struct got_worktree *worktree)
446 {
447 	return got_ref_dup(worktree->head_ref);
448 }
449 
450 const struct got_object_id *
451 got_worktree_get_base_commit_id(struct got_worktree *worktree)
452 {
453 	return worktree->base_commit_id;
454 }
455 
456 const struct got_error *
457 got_worktree_set_base_commit_id(struct got_worktree *worktree,
458     struct got_repository *repo, struct got_object_id *commit_id)
459 {
460 	const struct got_error *err;
461 	struct got_object *obj = NULL;
462 	char *id_str = NULL;
463 	char *path_got = NULL;
464 
465 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
466 	    GOT_WORKTREE_GOT_DIR) == -1) {
467 		err = got_error_from_errno();
468 		path_got = NULL;
469 		goto done;
470 	}
471 
472 	err = got_object_open(&obj, repo, commit_id);
473 	if (err)
474 		return err;
475 
476 	if (obj->type != GOT_OBJ_TYPE_COMMIT) {
477 		err = got_error(GOT_ERR_OBJ_TYPE);
478 		goto done;
479 	}
480 
481 	/* Record our base commit. */
482 	err = got_object_id_str(&id_str, commit_id);
483 	if (err)
484 		goto done;
485 	err = update_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, id_str);
486 	if (err)
487 		goto done;
488 
489 	free(worktree->base_commit_id);
490 	worktree->base_commit_id = got_object_id_dup(commit_id);
491 	if (worktree->base_commit_id == NULL) {
492 		err = got_error_from_errno();
493 		goto done;
494 	}
495 done:
496 	if (obj)
497 		got_object_close(obj);
498 	free(id_str);
499 	free(path_got);
500 	return err;
501 }
502 
503 static const struct got_error *
504 lock_worktree(struct got_worktree *worktree, int operation)
505 {
506 	if (flock(worktree->lockfd, operation | LOCK_NB) == -1)
507 		return (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
508 		    : got_error_from_errno());
509 	return NULL;
510 }
511 
512 static const char *
513 apply_path_prefix(struct got_worktree *worktree, const char *path)
514 {
515 	const char *p = path;
516 	p += strlen(worktree->path_prefix);
517 	if (*p == '/')
518 		p++;
519 	return p;
520 }
521 
522 static const struct got_error *
523 blob_checkout(struct got_worktree *worktree, struct got_fileindex *fileindex,
524    struct got_fileindex_entry *entry, const char *path,
525    struct got_blob_object *blob, struct got_repository *repo,
526    got_worktree_checkout_cb progress_cb, void *progress_arg,
527    const char *progress_path)
528 {
529 	const struct got_error *err = NULL;
530 	char *ondisk_path;
531 	int fd = -1;
532 	size_t len, hdrlen;
533 	int update = 0;
534 	char *tmppath = NULL;
535 
536 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path,
537 	    apply_path_prefix(worktree, path)) == -1)
538 		return got_error_from_errno();
539 
540 	fd = open(ondisk_path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
541 	    GOT_DEFAULT_FILE_MODE);
542 	if (fd == -1) {
543 		err = got_error_from_errno();
544 		if (errno == EEXIST) {
545 			struct stat sb;
546 			if (lstat(ondisk_path, &sb) == -1) {
547 				err = got_error_from_errno();
548 				goto done;
549 			} else if (!S_ISREG(sb.st_mode)) {
550 				/* TODO file is obstructed; do something */
551 				err = got_error(GOT_ERR_FILE_OBSTRUCTED);
552 				goto done;
553 			} else {
554 				err = got_opentemp_named_fd(&tmppath, &fd,
555 				    ondisk_path);
556 				if (err)
557 					goto done;
558 				update = 1;
559 			}
560 		} else
561 			return err;
562 	}
563 
564 	(*progress_cb)(progress_arg,
565 	    update ? GOT_STATUS_UPDATE : GOT_STATUS_ADD, progress_path);
566 
567 	hdrlen = got_object_blob_get_hdrlen(blob);
568 	do {
569 		const uint8_t *buf = got_object_blob_get_read_buf(blob);
570 		err = got_object_blob_read_block(&len, blob);
571 		if (err)
572 			break;
573 		if (len > 0) {
574 			/* Skip blob object header first time around. */
575 			ssize_t outlen = write(fd, buf + hdrlen, len - hdrlen);
576 			if (outlen == -1) {
577 				err = got_error_from_errno();
578 				goto done;
579 			} else if (outlen != len - hdrlen) {
580 				err = got_error(GOT_ERR_IO);
581 				goto done;
582 			}
583 			hdrlen = 0;
584 		}
585 	} while (len != 0);
586 
587 	fsync(fd);
588 
589 	if (update) {
590 		if (rename(tmppath, ondisk_path) != 0) {
591 			err = got_error_from_errno();
592 			goto done;
593 		}
594 	}
595 
596 	if (entry)
597 		err = got_fileindex_entry_update(entry, ondisk_path,
598 		    blob->id.sha1, worktree->base_commit_id->sha1);
599 	else {
600 		err = got_fileindex_entry_alloc(&entry, ondisk_path,
601 		    apply_path_prefix(worktree, path), blob->id.sha1,
602 		    worktree->base_commit_id->sha1);
603 		if (err)
604 			goto done;
605 		err = got_fileindex_entry_add(fileindex, entry);
606 	}
607 	if (err)
608 		goto done;
609 done:
610 	if (fd != -1)
611 		close(fd);
612 	free(ondisk_path);
613 	free(tmppath);
614 	return err;
615 }
616 
617 static const struct got_error *
618 add_dir_on_disk(struct got_worktree *worktree, const char *path)
619 {
620 	const struct got_error *err = NULL;
621 	char *abspath;
622 
623 	if (asprintf(&abspath, "%s/%s", worktree->root_path,
624 	    apply_path_prefix(worktree, path)) == -1)
625 		return got_error_from_errno();
626 
627 	/* XXX queue work rather than editing disk directly? */
628 	if (mkdir(abspath, GOT_DEFAULT_DIR_MODE) == -1) {
629 		struct stat sb;
630 
631 		if (errno != EEXIST) {
632 			err = got_error_from_errno();
633 			goto done;
634 		}
635 
636 		if (lstat(abspath, &sb) == -1) {
637 			err = got_error_from_errno();
638 			goto done;
639 		}
640 
641 		if (!S_ISDIR(sb.st_mode)) {
642 			/* TODO directory is obstructed; do something */
643 			return got_error(GOT_ERR_FILE_OBSTRUCTED);
644 		}
645 	}
646 
647 done:
648 	free(abspath);
649 	return err;
650 }
651 
652 static const struct got_error *
653 tree_checkout(struct got_worktree *, struct got_fileindex *,
654     struct got_tree_object *, const char *, struct got_repository *,
655     got_worktree_checkout_cb progress_cb, void *progress_arg,
656     got_worktree_cancel_cb cancel_cb, void *cancel_arg);
657 
658 static const struct got_error *
659 tree_checkout_entry(struct got_worktree *worktree,
660     struct got_fileindex *fileindex, struct got_tree_entry *te,
661     const char *parent, struct got_repository *repo,
662     got_worktree_checkout_cb progress_cb, void *progress_arg,
663     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
664 {
665 	const struct got_error *err = NULL;
666 	struct got_object *obj = NULL;
667 	struct got_blob_object *blob = NULL;
668 	struct got_fileindex_entry *entry = NULL;
669 	struct got_tree_object *tree = NULL;
670 	char *path = NULL;
671 	char *progress_path = NULL;
672 	size_t len;
673 
674 	if (parent[0] == '/' && parent[1] == '\0')
675 		parent = "";
676 	if (asprintf(&path, "%s/%s", parent, te->name) == -1)
677 		return got_error_from_errno();
678 
679 	/* Skip this entry if it is outside of our path prefix. */
680 	len = MIN(strlen(worktree->path_prefix), strlen(path));
681 	if (strncmp(path, worktree->path_prefix, len) != 0) {
682 		free(path);
683 		return NULL;
684 	}
685 
686 	err = got_object_open(&obj, repo, te->id);
687 	if (err)
688 		goto done;
689 
690 	progress_path = path;
691 	if (strncmp(progress_path, worktree->path_prefix, len) == 0)
692 		progress_path += len;
693 
694 	switch (obj->type) {
695 	case GOT_OBJ_TYPE_BLOB:
696 		if (strlen(worktree->path_prefix) >= strlen(path))
697 			break;
698 		entry = got_fileindex_entry_get(fileindex,
699 		    apply_path_prefix(worktree, path));
700 		if (entry &&
701 		    memcmp(entry->commit_sha1, worktree->base_commit_id->sha1,
702 		    SHA1_DIGEST_LENGTH) == 0) {
703 			(*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
704 			    progress_path);
705 			break;
706 		}
707 		if (entry && memcmp(entry->blob_sha1, obj->id.sha1,
708 		    SHA1_DIGEST_LENGTH) == 0)
709 			break;
710 		err = got_object_blob_open(&blob, repo, obj, 8192);
711 		if (err)
712 			goto done;
713 		err = blob_checkout(worktree, fileindex, entry, path, blob,
714 		    repo, progress_cb, progress_arg, progress_path);
715 		break;
716 	case GOT_OBJ_TYPE_TREE:
717 		if (strlen(worktree->path_prefix) < strlen(path)) {
718 			err = add_dir_on_disk(worktree, path);
719 			if (err)
720 				break;
721 		}
722 		err = got_object_tree_open(&tree, repo, obj);
723 		if (err)
724 			goto done;
725 		/* XXX infinite recursion possible */
726 		err = tree_checkout(worktree, fileindex, tree, path, repo,
727 		    progress_cb, progress_arg, cancel_cb, cancel_arg);
728 		break;
729 	default:
730 		break;
731 	}
732 
733 done:
734 	if (blob)
735 		got_object_blob_close(blob);
736 	if (tree)
737 		got_object_tree_close(tree);
738 	if (obj)
739 		got_object_close(obj);
740 	free(path);
741 	return err;
742 }
743 
744 static const struct got_error *
745 tree_checkout(struct got_worktree *worktree,
746     struct got_fileindex *fileindex, struct got_tree_object *tree,
747     const char *path, struct got_repository *repo,
748     got_worktree_checkout_cb progress_cb, void *progress_arg,
749     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
750 {
751 	const struct got_error *err = NULL;
752 	const struct got_tree_entries *entries;
753 	struct got_tree_entry *te;
754 	size_t len;
755 
756 	/* Skip this tree if it is outside of our path prefix. */
757 	len = MIN(strlen(worktree->path_prefix), strlen(path));
758 	if (strncmp(path, worktree->path_prefix, len) != 0)
759 		return NULL;
760 
761 	entries = got_object_tree_get_entries(tree);
762 	SIMPLEQ_FOREACH(te, &entries->head, entry) {
763 		if (cancel_cb) {
764 			err = (*cancel_cb)(cancel_arg);
765 			if (err)
766 				break;
767 		}
768 		err = tree_checkout_entry(worktree, fileindex, te, path, repo,
769 		    progress_cb, progress_arg, cancel_cb, cancel_arg);
770 		if (err)
771 			break;
772 	}
773 
774 	return err;
775 }
776 
777 const struct got_error *
778 got_worktree_checkout_files(struct got_worktree *worktree,
779     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
780     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
781 {
782 	const struct got_error *err = NULL, *unlockerr, *checkout_err = NULL;
783 	struct got_commit_object *commit = NULL;
784 	struct got_tree_object *tree = NULL;
785 	char *fileindex_path = NULL, *new_fileindex_path = NULL;
786 	struct got_fileindex *fileindex = NULL;
787 	FILE *index = NULL, *new_index = NULL;
788 
789 	err = lock_worktree(worktree, LOCK_EX);
790 	if (err)
791 		return err;
792 
793 	fileindex = got_fileindex_alloc();
794 	if (fileindex == NULL) {
795 		err = got_error_from_errno();
796 		goto done;
797 	}
798 
799 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
800 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
801 		err = got_error_from_errno();
802 		fileindex_path = NULL;
803 		goto done;
804 	}
805 
806 	/*
807 	 * Read the file index.
808 	 * Checking out files is supposed to be an idempotent operation.
809 	 * If the on-disk file index is incomplete we will try to complete it.
810 	 */
811 	index = fopen(fileindex_path, "rb");
812 	if (index == NULL) {
813 		err = got_error_from_errno();
814 		goto done;
815 	}
816 	err = got_fileindex_read(fileindex, index);
817 	fclose(index);
818 	if (err)
819 		goto done;
820 
821 	err = got_opentemp_named(&new_fileindex_path, &new_index,
822 	    fileindex_path);
823 	if (err)
824 		goto done;
825 
826 	err = got_object_open_as_commit(&commit, repo,
827 	   worktree->base_commit_id);
828 	if (err)
829 		goto done;
830 
831 	err = got_object_open_as_tree(&tree, repo, commit->tree_id);
832 	if (err)
833 		goto done;
834 
835 	checkout_err = tree_checkout(worktree, fileindex, tree, "/", repo,
836 	    progress_cb, progress_arg, cancel_cb, cancel_arg);
837 
838 	/* Try to sync the fileindex back to disk in any case. */
839 	err = got_fileindex_write(fileindex, new_index);
840 	if (err)
841 		goto done;
842 
843 	if (rename(new_fileindex_path, fileindex_path) != 0) {
844 		err = got_error_from_errno();
845 		goto done;
846 	}
847 
848 	free(new_fileindex_path);
849 	new_fileindex_path = NULL;
850 
851 done:
852 	if (tree)
853 		got_object_tree_close(tree);
854 	if (commit)
855 		got_object_commit_close(commit);
856 	if (new_fileindex_path)
857 		unlink(new_fileindex_path);
858 	if (new_index)
859 		fclose(new_index);
860 	free(new_fileindex_path);
861 	free(fileindex_path);
862 	got_fileindex_free(fileindex);
863 	if (checkout_err)
864 		err = checkout_err;
865 	unlockerr = lock_worktree(worktree, LOCK_SH);
866 	if (unlockerr && err == NULL)
867 		err = unlockerr;
868 	return err;
869 }