1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/stat.h>
18 #include <sys/limits.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 
22 #include <dirent.h>
23 #include <stddef.h>
24 #include <string.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <fcntl.h>
28 #include <errno.h>
29 #include <unistd.h>
30 #include <sha1.h>
31 #include <zlib.h>
32 #include <fnmatch.h>
33 #include <libgen.h>
34 #include <uuid.h>
35 #include <util.h>
36 
37 #include "got_error.h"
38 #include "got_repository.h"
39 #include "got_reference.h"
40 #include "got_object.h"
41 #include "got_worktree.h"
42 #include "got_opentemp.h"
43 #include "got_path.h"
44 
45 #include "got_lib_worktree.h"
46 #include "got_lib_sha1.h"
47 #include "got_lib_fileindex.h"
48 #include "got_lib_inflate.h"
49 #include "got_lib_delta.h"
50 #include "got_lib_object.h"
51 #include "got_lib_object_parse.h"
52 #include "got_lib_object_create.h"
53 #include "got_lib_object_idset.h"
54 #include "got_lib_diff.h"
55 
56 #ifndef MIN
57 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
58 #endif
59 
60 static const struct got_error *
61 create_meta_file(const char *path_got, const char *name, const char *content)
62 {
63 	const struct got_error *err = NULL;
64 	char *path;
65 	int fd = -1;
66 
67 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
68 		err = got_error_prefix_errno("asprintf");
69 		path = NULL;
70 		goto done;
71 	}
72 
73 	fd = open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
74 	    GOT_DEFAULT_FILE_MODE);
75 	if (fd == -1) {
76 		err = got_error_prefix_errno2("open", path);
77 		goto done;
78 	}
79 
80 	if (content) {
81 		int len = dprintf(fd, "%s\n", content);
82 		if (len != strlen(content) + 1) {
83 			err = got_error_prefix_errno("dprintf");
84 			goto done;
85 		}
86 	}
87 
88 done:
89 	if (fd != -1 && close(fd) == -1 && err == NULL)
90 		err = got_error_prefix_errno("close");
91 	free(path);
92 	return err;
93 }
94 
95 static const struct got_error *
96 update_meta_file(const char *path_got, const char *name, const char *content)
97 {
98 	const struct got_error *err = NULL;
99 	FILE *tmpfile = NULL;
100 	char *tmppath = NULL;
101 	char *path = NULL;
102 
103 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
104 		err = got_error_prefix_errno("asprintf");
105 		path = NULL;
106 		goto done;
107 	}
108 
109 	err = got_opentemp_named(&tmppath, &tmpfile, path);
110 	if (err)
111 		goto done;
112 
113 	if (content) {
114 		int len = fprintf(tmpfile, "%s\n", content);
115 		if (len != strlen(content) + 1) {
116 			err = got_error_prefix_errno2("fprintf", tmppath);
117 			goto done;
118 		}
119 	}
120 
121 	if (rename(tmppath, path) != 0) {
122 		err = got_error_prefix_errno3("rename", tmppath, path);
123 		unlink(tmppath);
124 		goto done;
125 	}
126 
127 done:
128 	if (fclose(tmpfile) != 0 && err == NULL)
129 		err = got_error_prefix_errno2("fclose", tmppath);
130 	free(tmppath);
131 	return err;
132 }
133 
134 static const struct got_error *
135 read_meta_file(char **content, const char *path_got, const char *name)
136 {
137 	const struct got_error *err = NULL;
138 	char *path;
139 	int fd = -1;
140 	ssize_t n;
141 	struct stat sb;
142 
143 	*content = NULL;
144 
145 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
146 		err = got_error_prefix_errno("asprintf");
147 		path = NULL;
148 		goto done;
149 	}
150 
151 	fd = open(path, O_RDONLY | O_NOFOLLOW);
152 	if (fd == -1) {
153 		if (errno == ENOENT)
154 			err = got_error(GOT_ERR_WORKTREE_META);
155 		else
156 			err = got_error_prefix_errno2("open", path);
157 		goto done;
158 	}
159 	if (flock(fd, LOCK_SH | LOCK_NB) == -1) {
160 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
161 		    : got_error_prefix_errno2("flock", path));
162 		goto done;
163 	}
164 
165 	if (lstat(path, &sb) != 0) {
166 		err = got_error_prefix_errno2("lstat", path);
167 		goto done;
168 	}
169 	*content = calloc(1, sb.st_size);
170 	if (*content == NULL) {
171 		err = got_error_prefix_errno("calloc");
172 		goto done;
173 	}
174 
175 	n = read(fd, *content, sb.st_size);
176 	if (n != sb.st_size) {
177 		err = (n == -1 ? got_error_prefix_errno2("read", path) :
178 		    got_error(GOT_ERR_WORKTREE_META));
179 		goto done;
180 	}
181 	if ((*content)[sb.st_size - 1] != '\n') {
182 		err = got_error(GOT_ERR_WORKTREE_META);
183 		goto done;
184 	}
185 	(*content)[sb.st_size - 1] = '\0';
186 
187 done:
188 	if (fd != -1 && close(fd) == -1 && err == NULL)
189 		err = got_error_prefix_errno2("close", path_got);
190 	free(path);
191 	if (err) {
192 		free(*content);
193 		*content = NULL;
194 	}
195 	return err;
196 }
197 
198 const struct got_error *
199 got_worktree_init(const char *path, struct got_reference *head_ref,
200     const char *prefix, struct got_repository *repo)
201 {
202 	const struct got_error *err = NULL;
203 	struct got_object_id *commit_id = NULL;
204 	uuid_t uuid;
205 	uint32_t uuid_status;
206 	int obj_type;
207 	char *path_got = NULL;
208 	char *refstr = NULL;
209 	char *formatstr = NULL;
210 	char *absprefix = NULL;
211 	char *basestr = NULL;
212 	char *uuidstr = NULL;
213 
214 	if (strcmp(path, got_repo_get_path(repo)) == 0) {
215 		err = got_error(GOT_ERR_WORKTREE_REPO);
216 		goto done;
217 	}
218 
219 	err = got_ref_resolve(&commit_id, repo, head_ref);
220 	if (err)
221 		return err;
222 	err = got_object_get_type(&obj_type, repo, commit_id);
223 	if (err)
224 		return err;
225 	if (obj_type != GOT_OBJ_TYPE_COMMIT)
226 		return got_error(GOT_ERR_OBJ_TYPE);
227 
228 	if (!got_path_is_absolute(prefix)) {
229 		if (asprintf(&absprefix, "/%s", prefix) == -1)
230 			return got_error_prefix_errno("asprintf");
231 	}
232 
233 	/* Create top-level directory (may already exist). */
234 	if (mkdir(path, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
235 		err = got_error_prefix_errno2("mkdir", path);
236 		goto done;
237 	}
238 
239 	/* Create .got directory (may already exist). */
240 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
241 		err = got_error_prefix_errno("asprintf");
242 		goto done;
243 	}
244 	if (mkdir(path_got, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
245 		err = got_error_prefix_errno2("mkdir", path_got);
246 		goto done;
247 	}
248 
249 	/* Create an empty lock file. */
250 	err = create_meta_file(path_got, GOT_WORKTREE_LOCK, NULL);
251 	if (err)
252 		goto done;
253 
254 	/* Create an empty file index. */
255 	err = create_meta_file(path_got, GOT_WORKTREE_FILE_INDEX, NULL);
256 	if (err)
257 		goto done;
258 
259 	/* Write the HEAD reference. */
260 	refstr = got_ref_to_str(head_ref);
261 	if (refstr == NULL) {
262 		err = got_error_prefix_errno("got_ref_to_str");
263 		goto done;
264 	}
265 	err = create_meta_file(path_got, GOT_WORKTREE_HEAD_REF, refstr);
266 	if (err)
267 		goto done;
268 
269 	/* Record our base commit. */
270 	err = got_object_id_str(&basestr, commit_id);
271 	if (err)
272 		goto done;
273 	err = create_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, basestr);
274 	if (err)
275 		goto done;
276 
277 	/* Store path to repository. */
278 	err = create_meta_file(path_got, GOT_WORKTREE_REPOSITORY,
279 	    got_repo_get_path(repo));
280 	if (err)
281 		goto done;
282 
283 	/* Store in-repository path prefix. */
284 	err = create_meta_file(path_got, GOT_WORKTREE_PATH_PREFIX,
285 	    absprefix ? absprefix : prefix);
286 	if (err)
287 		goto done;
288 
289 	/* Generate UUID. */
290 	uuid_create(&uuid, &uuid_status);
291 	if (uuid_status != uuid_s_ok) {
292 		err = got_error_uuid(uuid_status);
293 		goto done;
294 	}
295 	uuid_to_string(&uuid, &uuidstr, &uuid_status);
296 	if (uuid_status != uuid_s_ok) {
297 		err = got_error_uuid(uuid_status);
298 		goto done;
299 	}
300 	err = create_meta_file(path_got, GOT_WORKTREE_UUID, uuidstr);
301 	if (err)
302 		goto done;
303 
304 	/* Stamp work tree with format file. */
305 	if (asprintf(&formatstr, "%d", GOT_WORKTREE_FORMAT_VERSION) == -1) {
306 		err = got_error_prefix_errno("asprintf");
307 		goto done;
308 	}
309 	err = create_meta_file(path_got, GOT_WORKTREE_FORMAT, formatstr);
310 	if (err)
311 		goto done;
312 
313 done:
314 	free(commit_id);
315 	free(path_got);
316 	free(formatstr);
317 	free(refstr);
318 	free(absprefix);
319 	free(basestr);
320 	free(uuidstr);
321 	return err;
322 }
323 
324 static const struct got_error *
325 open_worktree(struct got_worktree **worktree, const char *path)
326 {
327 	const struct got_error *err = NULL;
328 	char *path_got;
329 	char *formatstr = NULL;
330 	char *uuidstr = NULL;
331 	char *path_lock = NULL;
332 	char *base_commit_id_str = NULL;
333 	int version, fd = -1;
334 	const char *errstr;
335 	struct got_repository *repo = NULL;
336 	uint32_t uuid_status;
337 
338 	*worktree = NULL;
339 
340 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
341 		err = got_error_prefix_errno("asprintf");
342 		path_got = NULL;
343 		goto done;
344 	}
345 
346 	if (asprintf(&path_lock, "%s/%s", path_got, GOT_WORKTREE_LOCK) == -1) {
347 		err = got_error_prefix_errno("asprintf");
348 		path_lock = NULL;
349 		goto done;
350 	}
351 
352 	fd = open(path_lock, O_RDWR | O_EXLOCK | O_NONBLOCK);
353 	if (fd == -1) {
354 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
355 		    : got_error_prefix_errno2("open", path_lock));
356 		goto done;
357 	}
358 
359 	err = read_meta_file(&formatstr, path_got, GOT_WORKTREE_FORMAT);
360 	if (err)
361 		goto done;
362 
363 	version = strtonum(formatstr, 1, INT_MAX, &errstr);
364 	if (errstr) {
365 		err = got_error(GOT_ERR_WORKTREE_META);
366 		goto done;
367 	}
368 	if (version != GOT_WORKTREE_FORMAT_VERSION) {
369 		err = got_error(GOT_ERR_WORKTREE_VERS);
370 		goto done;
371 	}
372 
373 	*worktree = calloc(1, sizeof(**worktree));
374 	if (*worktree == NULL) {
375 		err = got_error_prefix_errno("calloc");
376 		goto done;
377 	}
378 	(*worktree)->lockfd = -1;
379 
380 	(*worktree)->root_path = strdup(path);
381 	if ((*worktree)->root_path == NULL) {
382 		err = got_error_prefix_errno("strdup");
383 		goto done;
384 	}
385 	err = read_meta_file(&(*worktree)->repo_path, path_got,
386 	    GOT_WORKTREE_REPOSITORY);
387 	if (err)
388 		goto done;
389 
390 	err = read_meta_file(&(*worktree)->path_prefix, path_got,
391 	    GOT_WORKTREE_PATH_PREFIX);
392 	if (err)
393 		goto done;
394 
395 	err = read_meta_file(&base_commit_id_str, path_got,
396 	    GOT_WORKTREE_BASE_COMMIT);
397 	if (err)
398 		goto done;
399 
400 	err = read_meta_file(&uuidstr, path_got, GOT_WORKTREE_UUID);
401 	if (err)
402 		goto done;
403 	uuid_from_string(uuidstr, &(*worktree)->uuid, &uuid_status);
404 	if (uuid_status != uuid_s_ok) {
405 		err = got_error_uuid(uuid_status);
406 		goto done;
407 	}
408 
409 	err = got_repo_open(&repo, (*worktree)->repo_path);
410 	if (err)
411 		goto done;
412 
413 	err = got_object_resolve_id_str(&(*worktree)->base_commit_id, repo,
414 	    base_commit_id_str);
415 	if (err)
416 		goto done;
417 
418 	err = read_meta_file(&(*worktree)->head_ref_name, path_got,
419 	    GOT_WORKTREE_HEAD_REF);
420 done:
421 	if (repo)
422 		got_repo_close(repo);
423 	free(path_got);
424 	free(path_lock);
425 	free(base_commit_id_str);
426 	free(uuidstr);
427 	free(formatstr);
428 	if (err) {
429 		if (fd != -1)
430 			close(fd);
431 		if (*worktree != NULL)
432 			got_worktree_close(*worktree);
433 		*worktree = NULL;
434 	} else
435 		(*worktree)->lockfd = fd;
436 
437 	return err;
438 }
439 
440 const struct got_error *
441 got_worktree_open(struct got_worktree **worktree, const char *path)
442 {
443 	const struct got_error *err = NULL;
444 
445 	do {
446 		err = open_worktree(worktree, path);
447 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT))
448 			return err;
449 		if (*worktree)
450 			return NULL;
451 		path = dirname(path);
452 		if (path == NULL)
453 			return got_error_prefix_errno2("dirname", path);
454 	} while (!((path[0] == '.' || path[0] == '/') && path[1] == '\0'));
455 
456 	return got_error(GOT_ERR_NOT_WORKTREE);
457 }
458 
459 const struct got_error *
460 got_worktree_close(struct got_worktree *worktree)
461 {
462 	const struct got_error *err = NULL;
463 	free(worktree->root_path);
464 	free(worktree->repo_path);
465 	free(worktree->path_prefix);
466 	free(worktree->base_commit_id);
467 	free(worktree->head_ref_name);
468 	if (worktree->lockfd != -1)
469 		if (close(worktree->lockfd) != 0)
470 			err = got_error_prefix_errno2("close",
471 			    got_worktree_get_root_path(worktree));
472 	free(worktree);
473 	return err;
474 }
475 
476 const char *
477 got_worktree_get_root_path(struct got_worktree *worktree)
478 {
479 	return worktree->root_path;
480 }
481 
482 const char *
483 got_worktree_get_repo_path(struct got_worktree *worktree)
484 {
485 	return worktree->repo_path;
486 }
487 
488 const char *
489 got_worktree_get_path_prefix(struct got_worktree *worktree)
490 {
491 	return worktree->path_prefix;
492 }
493 
494 const struct got_error *
495 got_worktree_match_path_prefix(int *match, struct got_worktree *worktree,
496     const char *path_prefix)
497 {
498 	char *absprefix = NULL;
499 
500 	if (!got_path_is_absolute(path_prefix)) {
501 		if (asprintf(&absprefix, "/%s", path_prefix) == -1)
502 			return got_error_prefix_errno("asprintf");
503 	}
504 	*match = (strcmp(absprefix ? absprefix : path_prefix,
505 	    worktree->path_prefix) == 0);
506 	free(absprefix);
507 	return NULL;
508 }
509 
510 const char *
511 got_worktree_get_head_ref_name(struct got_worktree *worktree)
512 {
513 	return worktree->head_ref_name;
514 }
515 
516 struct got_object_id *
517 got_worktree_get_base_commit_id(struct got_worktree *worktree)
518 {
519 	return worktree->base_commit_id;
520 }
521 
522 const struct got_error *
523 got_worktree_set_base_commit_id(struct got_worktree *worktree,
524     struct got_repository *repo, struct got_object_id *commit_id)
525 {
526 	const struct got_error *err;
527 	struct got_object *obj = NULL;
528 	char *id_str = NULL;
529 	char *path_got = NULL;
530 
531 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
532 	    GOT_WORKTREE_GOT_DIR) == -1) {
533 		err = got_error_prefix_errno("asprintf");
534 		path_got = NULL;
535 		goto done;
536 	}
537 
538 	err = got_object_open(&obj, repo, commit_id);
539 	if (err)
540 		return err;
541 
542 	if (obj->type != GOT_OBJ_TYPE_COMMIT) {
543 		err = got_error(GOT_ERR_OBJ_TYPE);
544 		goto done;
545 	}
546 
547 	/* Record our base commit. */
548 	err = got_object_id_str(&id_str, commit_id);
549 	if (err)
550 		goto done;
551 	err = update_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, id_str);
552 	if (err)
553 		goto done;
554 
555 	free(worktree->base_commit_id);
556 	worktree->base_commit_id = got_object_id_dup(commit_id);
557 	if (worktree->base_commit_id == NULL) {
558 		err = got_error_prefix_errno("got_object_id_dup");
559 		goto done;
560 	}
561 done:
562 	if (obj)
563 		got_object_close(obj);
564 	free(id_str);
565 	free(path_got);
566 	return err;
567 }
568 
569 static const struct got_error *
570 lock_worktree(struct got_worktree *worktree, int operation)
571 {
572 	if (flock(worktree->lockfd, operation | LOCK_NB) == -1)
573 		return (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
574 		    : got_error_prefix_errno2("flock",
575 		    got_worktree_get_root_path(worktree)));
576 	return NULL;
577 }
578 
579 static const struct got_error *
580 add_dir_on_disk(struct got_worktree *worktree, const char *path)
581 {
582 	const struct got_error *err = NULL;
583 	char *abspath;
584 
585 	if (asprintf(&abspath, "%s/%s", worktree->root_path, path) == -1)
586 		return got_error_prefix_errno("asprintf");
587 
588 	err = got_path_mkdir(abspath);
589 	if (err && err->code == GOT_ERR_ERRNO && errno == EEXIST) {
590 		struct stat sb;
591 		err = NULL;
592 		if (lstat(abspath, &sb) == -1) {
593 			err = got_error_prefix_errno2("lstat", abspath);
594 		} else if (!S_ISDIR(sb.st_mode)) {
595 			/* TODO directory is obstructed; do something */
596 			err = got_error(GOT_ERR_FILE_OBSTRUCTED);
597 		}
598 	}
599 	free(abspath);
600 	return err;
601 }
602 
603 static const struct got_error *
604 check_file_contents_equal(int *same, FILE *f1, FILE *f2)
605 {
606 	const struct got_error *err = NULL;
607 	uint8_t fbuf1[8192];
608 	uint8_t fbuf2[8192];
609 	size_t flen1 = 0, flen2 = 0;
610 
611 	*same = 1;
612 
613 	for (;;) {
614 		flen1 = fread(fbuf1, 1, sizeof(fbuf1), f1);
615 		if (flen1 == 0 && ferror(f1)) {
616 			err = got_error_prefix_errno("fread");
617 			break;
618 		}
619 		flen2 = fread(fbuf2, 1, sizeof(fbuf2), f2);
620 		if (flen2 == 0 && ferror(f2)) {
621 			err = got_error_prefix_errno("fread");
622 			break;
623 		}
624 		if (flen1 == 0) {
625 			if (flen2 != 0)
626 				*same = 0;
627 			break;
628 		} else if (flen2 == 0) {
629 			if (flen1 != 0)
630 				*same = 0;
631 			break;
632 		} else if (flen1 == flen2) {
633 			if (memcmp(fbuf1, fbuf2, flen2) != 0) {
634 				*same = 0;
635 				break;
636 			}
637 		} else {
638 			*same = 0;
639 			break;
640 		}
641 	}
642 
643 	return err;
644 }
645 
646 static const struct got_error *
647 check_files_equal(int *same, const char *f1_path, const char *f2_path)
648 {
649 	const struct got_error *err = NULL;
650 	struct stat sb;
651 	size_t size1, size2;
652 	FILE *f1 = NULL, *f2 = NULL;
653 
654 	*same = 1;
655 
656 	if (lstat(f1_path, &sb) != 0) {
657 		err = got_error_prefix_errno2("lstat", f1_path);
658 		goto done;
659 	}
660 	size1 = sb.st_size;
661 
662 	if (lstat(f2_path, &sb) != 0) {
663 		err = got_error_prefix_errno2("lstat", f2_path);
664 		goto done;
665 	}
666 	size2 = sb.st_size;
667 
668 	if (size1 != size2) {
669 		*same = 0;
670 		return NULL;
671 	}
672 
673 	f1 = fopen(f1_path, "r");
674 	if (f1 == NULL)
675 		return got_error_prefix_errno2("open", f1_path);
676 
677 	f2 = fopen(f2_path, "r");
678 	if (f2 == NULL) {
679 		err = got_error_prefix_errno2("open", f2_path);
680 		goto done;
681 	}
682 
683 	err = check_file_contents_equal(same, f1, f2);
684 done:
685 	if (f1 && fclose(f1) != 0 && err == NULL)
686 		err = got_error_prefix_errno("fclose");
687 	if (f2 && fclose(f2) != 0 && err == NULL)
688 		err = got_error_prefix_errno("fclose");
689 
690 	return err;
691 }
692 
693 /*
694  * Perform a 3-way merge where the file's version in the file index (blob2)
695  * acts as the common ancestor, the incoming blob (blob1) acts as the first
696  * derived version, and the file on disk acts as the second derived version.
697  */
698 static const struct got_error *
699 merge_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
700    struct got_fileindex_entry *ie, const char *ondisk_path, const char *path,
701    uint16_t te_mode, uint16_t st_mode, struct got_blob_object *blob1,
702    struct got_repository *repo,
703    got_worktree_checkout_cb progress_cb, void *progress_arg)
704 {
705 	const struct got_error *err = NULL;
706 	int merged_fd = -1;
707 	struct got_blob_object *blob2 = NULL;
708 	FILE *f1 = NULL, *f2 = NULL;
709 	char *blob1_path = NULL, *blob2_path = NULL;
710 	char *merged_path = NULL, *base_path = NULL;
711 	char *id_str = NULL;
712 	char *label1 = NULL;
713 	int overlapcnt = 0, update_timestamps = 0;
714 	char *parent;
715 
716 	parent = dirname(ondisk_path);
717 	if (parent == NULL)
718 		return got_error_prefix_errno2("dirname", ondisk_path);
719 
720 	if (asprintf(&base_path, "%s/got-merged", parent) == -1)
721 		return got_error_prefix_errno("asprintf");
722 
723 	err = got_opentemp_named_fd(&merged_path, &merged_fd, base_path);
724 	if (err)
725 		goto done;
726 
727 	free(base_path);
728 	if (asprintf(&base_path, "%s/got-merge-blob1", parent) == -1) {
729 		err = got_error_prefix_errno("asprintf");
730 		base_path = NULL;
731 		goto done;
732 	}
733 
734 	err = got_opentemp_named(&blob1_path, &f1, base_path);
735 	if (err)
736 		goto done;
737 	err = got_object_blob_dump_to_file(NULL, NULL, f1, blob1);
738 	if (err)
739 		goto done;
740 
741 	free(base_path);
742 	if (asprintf(&base_path, "%s/got-merge-blob2", parent) == -1) {
743 		err = got_error_prefix_errno("asprintf");
744 		base_path = NULL;
745 		goto done;
746 	}
747 
748 	err = got_opentemp_named(&blob2_path, &f2, base_path);
749 	if (err)
750 		goto done;
751 	if (got_fileindex_entry_has_blob(ie)) {
752 		struct got_object_id id2;
753 		memcpy(id2.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
754 		err = got_object_open_as_blob(&blob2, repo, &id2, 8192);
755 		if (err)
756 			goto done;
757 		err = got_object_blob_dump_to_file(NULL, NULL, f2, blob2);
758 		if (err)
759 			goto done;
760 	} else {
761 		/*
762 		 * If the file has no blob, this is an "add vs add" conflict,
763 		 * and we simply use an empty ancestor file to make both files
764 		 * appear in the merged result in their entirety.
765 		 */
766 	}
767 
768 	err = got_object_id_str(&id_str, worktree->base_commit_id);
769 	if (err)
770 		goto done;
771 	if (asprintf(&label1, "commit %s", id_str) == -1) {
772 		err = got_error_prefix_errno("asprintf");
773 		goto done;
774 	}
775 
776 	err = got_merge_diff3(&overlapcnt, merged_fd, blob1_path,
777 	    blob2_path, ondisk_path, label1, path);
778 	if (err)
779 		goto done;
780 
781 	(*progress_cb)(progress_arg,
782 	    overlapcnt > 0 ? GOT_STATUS_CONFLICT : GOT_STATUS_MERGE, path);
783 
784 	if (fsync(merged_fd) != 0) {
785 		err = got_error_prefix_errno("fsync");
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_prefix_errno2("chmod", merged_path);
799 		goto done;
800 	}
801 
802 	if (rename(merged_path, ondisk_path) != 0) {
803 		err = got_error_prefix_errno3("rename", merged_path,
804 		    ondisk_path);
805 		unlink(merged_path);
806 		goto done;
807 	}
808 
809 	/*
810 	 * Do not update timestamps of already modified files. Otherwise,
811 	 * a future status walk would treat them as unmodified files again.
812 	 */
813 	err = got_fileindex_entry_update(ie, ondisk_path,
814 	    blob1->id.sha1, worktree->base_commit_id->sha1, update_timestamps);
815 done:
816 	if (merged_fd != -1 && close(merged_fd) != 0 && err == NULL)
817 		err = got_error_prefix_errno("close");
818 	if (f1 && fclose(f1) != 0 && err == NULL)
819 		err = got_error_prefix_errno("fclose");
820 	if (f2 && fclose(f2) != 0 && err == NULL)
821 		err = got_error_prefix_errno("fclose");
822 	if (blob2)
823 		got_object_blob_close(blob2);
824 	free(merged_path);
825 	free(base_path);
826 	if (blob1_path) {
827 		unlink(blob1_path);
828 		free(blob1_path);
829 	}
830 	if (blob2_path) {
831 		unlink(blob2_path);
832 		free(blob2_path);
833 	}
834 	free(id_str);
835 	free(label1);
836 	return err;
837 }
838 
839 static const struct got_error *
840 update_blob_fileindex_entry(struct got_worktree *worktree,
841     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
842     const char *ondisk_path, const char *path, struct got_blob_object *blob,
843     int update_timestamps)
844 {
845 	const struct got_error *err = NULL;
846 
847 	if (ie == NULL)
848 		ie = got_fileindex_entry_get(fileindex, path);
849 	if (ie)
850 		err = got_fileindex_entry_update(ie, ondisk_path,
851 		    blob->id.sha1, worktree->base_commit_id->sha1,
852 		    update_timestamps);
853 	else {
854 		struct got_fileindex_entry *new_ie;
855 		err = got_fileindex_entry_alloc(&new_ie, ondisk_path,
856 		    path, blob->id.sha1, worktree->base_commit_id->sha1);
857 		if (!err)
858 			err = got_fileindex_entry_add(fileindex, new_ie);
859 	}
860 	return err;
861 }
862 
863 static const struct got_error *
864 install_blob(struct got_worktree *worktree, const char *ondisk_path,
865    const char *path, uint16_t te_mode, uint16_t st_mode,
866    struct got_blob_object *blob, int restoring_missing_file,
867    int reverting_versioned_file, struct got_repository *repo,
868    got_worktree_checkout_cb progress_cb, void *progress_arg)
869 {
870 	const struct got_error *err = NULL;
871 	int fd = -1;
872 	size_t len, hdrlen;
873 	int update = 0;
874 	char *tmppath = NULL;
875 
876 	fd = open(ondisk_path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
877 	    GOT_DEFAULT_FILE_MODE);
878 	if (fd == -1) {
879 		if (errno == ENOENT) {
880 			char *parent = dirname(path);
881 			if (parent == NULL)
882 				return got_error_prefix_errno2("dirname", path);
883 			err = add_dir_on_disk(worktree, parent);
884 			if (err)
885 				return err;
886 			fd = open(ondisk_path,
887 			    O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
888 			    GOT_DEFAULT_FILE_MODE);
889 			if (fd == -1)
890 				return got_error_prefix_errno2("open",
891 				    ondisk_path);
892 		} else if (errno == EEXIST) {
893 			if (!S_ISREG(st_mode)) {
894 				/* TODO file is obstructed; do something */
895 				err = got_error(GOT_ERR_FILE_OBSTRUCTED);
896 				goto done;
897 			} else {
898 				err = got_opentemp_named_fd(&tmppath, &fd,
899 				    ondisk_path);
900 				if (err)
901 					goto done;
902 				update = 1;
903 			}
904 		} else
905 			return got_error_prefix_errno2("open", ondisk_path);
906 	}
907 
908 	if (restoring_missing_file)
909 		(*progress_cb)(progress_arg, GOT_STATUS_MISSING, path);
910 	else if (reverting_versioned_file)
911 		(*progress_cb)(progress_arg, GOT_STATUS_REVERT, path);
912 	else
913 		(*progress_cb)(progress_arg,
914 		    update ? GOT_STATUS_UPDATE : GOT_STATUS_ADD, path);
915 
916 	hdrlen = got_object_blob_get_hdrlen(blob);
917 	do {
918 		const uint8_t *buf = got_object_blob_get_read_buf(blob);
919 		err = got_object_blob_read_block(&len, blob);
920 		if (err)
921 			break;
922 		if (len > 0) {
923 			/* Skip blob object header first time around. */
924 			ssize_t outlen = write(fd, buf + hdrlen, len - hdrlen);
925 			if (outlen == -1) {
926 				err = got_error_prefix_errno("write");
927 				goto done;
928 			} else if (outlen != len - hdrlen) {
929 				err = got_error(GOT_ERR_IO);
930 				goto done;
931 			}
932 			hdrlen = 0;
933 		}
934 	} while (len != 0);
935 
936 	if (fsync(fd) != 0) {
937 		err = got_error_prefix_errno("fsync");
938 		goto done;
939 	}
940 
941 	if (update) {
942 		if (rename(tmppath, ondisk_path) != 0) {
943 			err = got_error_prefix_errno3("rename", tmppath,
944 			    ondisk_path);
945 			unlink(tmppath);
946 			goto done;
947 		}
948 	}
949 
950 	if (te_mode & S_IXUSR) {
951 		if (chmod(ondisk_path, st_mode | S_IXUSR) == -1) {
952 			err = got_error_prefix_errno2("chmod", ondisk_path);
953 			goto done;
954 		}
955 	} else {
956 		if (chmod(ondisk_path, st_mode & ~S_IXUSR) == -1) {
957 			err = got_error_prefix_errno2("chmod", ondisk_path);
958 			goto done;
959 		}
960 	}
961 
962 done:
963 	if (fd != -1 && close(fd) != 0 && err == NULL)
964 		err = got_error_prefix_errno("close");
965 	free(tmppath);
966 	return err;
967 }
968 
969 /* Upgrade STATUS_MODIFY to STATUS_CONFLICT if a conflict marker is found. */
970 static const struct got_error *
971 get_modified_file_content_status(unsigned char *status, FILE *f)
972 {
973 	const struct got_error *err = NULL;
974 	const char *markers[3] = {
975 		GOT_DIFF_CONFLICT_MARKER_BEGIN,
976 		GOT_DIFF_CONFLICT_MARKER_SEP,
977 		GOT_DIFF_CONFLICT_MARKER_END
978 	};
979 	int i = 0;
980 	char *line;
981 	size_t len;
982 	const char delim[3] = {'\0', '\0', '\0'};
983 
984 	while (*status == GOT_STATUS_MODIFY) {
985 		line = fparseln(f, &len, NULL, delim, 0);
986 		if (line == NULL) {
987 			if (feof(f))
988 				break;
989 			err = got_ferror(f, GOT_ERR_IO);
990 			break;
991 		}
992 
993 		if (strncmp(line, markers[i], strlen(markers[i])) == 0) {
994 			if (markers[i] == GOT_DIFF_CONFLICT_MARKER_END)
995 				*status = GOT_STATUS_CONFLICT;
996 			else
997 				i++;
998 		}
999 	}
1000 
1001 	return err;
1002 }
1003 
1004 static const struct got_error *
1005 get_file_status(unsigned char *status, struct stat *sb,
1006     struct got_fileindex_entry *ie, const char *abspath,
1007     struct got_repository *repo)
1008 {
1009 	const struct got_error *err = NULL;
1010 	struct got_object_id id;
1011 	size_t hdrlen;
1012 	FILE *f = NULL;
1013 	uint8_t fbuf[8192];
1014 	struct got_blob_object *blob = NULL;
1015 	size_t flen, blen;
1016 
1017 	*status = GOT_STATUS_NO_CHANGE;
1018 
1019 	if (lstat(abspath, sb) == -1) {
1020 		if (errno == ENOENT) {
1021 			if (ie) {
1022 				if (got_fileindex_entry_has_file_on_disk(ie))
1023 					*status = GOT_STATUS_MISSING;
1024 				else
1025 					*status = GOT_STATUS_DELETE;
1026 				sb->st_mode =
1027 				    ((ie->mode >> GOT_FILEIDX_MODE_PERMS_SHIFT)
1028 				    & (S_IRWXU | S_IRWXG | S_IRWXO));
1029 			} else
1030 				sb->st_mode = GOT_DEFAULT_FILE_MODE;
1031 			return NULL;
1032 		}
1033 		return got_error_prefix_errno2("lstat", abspath);
1034 	}
1035 
1036 	if (!S_ISREG(sb->st_mode)) {
1037 		*status = GOT_STATUS_OBSTRUCTED;
1038 		return NULL;
1039 	}
1040 
1041 	if (ie == NULL)
1042 		return NULL;
1043 
1044 	if (!got_fileindex_entry_has_file_on_disk(ie)) {
1045 		*status = GOT_STATUS_DELETE;
1046 		return NULL;
1047 	} else if (!got_fileindex_entry_has_blob(ie)) {
1048 		*status = GOT_STATUS_ADD;
1049 		return NULL;
1050 	}
1051 
1052 	if (ie->ctime_sec == sb->st_ctime &&
1053 	    ie->ctime_nsec == sb->st_ctimensec &&
1054 	    ie->mtime_sec == sb->st_mtime &&
1055 	    ie->mtime_sec == sb->st_mtime &&
1056 	    ie->mtime_nsec == sb->st_mtimensec &&
1057 	    ie->size == (sb->st_size & 0xffffffff))
1058 		return NULL;
1059 
1060 	memcpy(id.sha1, ie->blob_sha1, sizeof(id.sha1));
1061 	err = got_object_open_as_blob(&blob, repo, &id, sizeof(fbuf));
1062 	if (err)
1063 		return err;
1064 
1065 	f = fopen(abspath, "r");
1066 	if (f == NULL) {
1067 		err = got_error_prefix_errno2("fopen", abspath);
1068 		goto done;
1069 	}
1070 	hdrlen = got_object_blob_get_hdrlen(blob);
1071 	while (1) {
1072 		const uint8_t *bbuf = got_object_blob_get_read_buf(blob);
1073 		err = got_object_blob_read_block(&blen, blob);
1074 		if (err)
1075 			goto done;
1076 		/* Skip length of blob object header first time around. */
1077 		flen = fread(fbuf, 1, sizeof(fbuf) - hdrlen, f);
1078 		if (flen == 0 && ferror(f)) {
1079 			err = got_error_prefix_errno("fread");
1080 			goto done;
1081 		}
1082 		if (blen == 0) {
1083 			if (flen != 0)
1084 				*status = GOT_STATUS_MODIFY;
1085 			break;
1086 		} else if (flen == 0) {
1087 			if (blen != 0)
1088 				*status = GOT_STATUS_MODIFY;
1089 			break;
1090 		} else if (blen - hdrlen == flen) {
1091 			/* Skip blob object header first time around. */
1092 			if (memcmp(bbuf + hdrlen, fbuf, flen) != 0) {
1093 				*status = GOT_STATUS_MODIFY;
1094 				break;
1095 			}
1096 		} else {
1097 			*status = GOT_STATUS_MODIFY;
1098 			break;
1099 		}
1100 		hdrlen = 0;
1101 	}
1102 
1103 	if (*status == GOT_STATUS_MODIFY) {
1104 		rewind(f);
1105 		err = get_modified_file_content_status(status, f);
1106 	}
1107 done:
1108 	if (blob)
1109 		got_object_blob_close(blob);
1110 	if (f)
1111 		fclose(f);
1112 	return err;
1113 }
1114 
1115 static const struct got_error *
1116 update_blob(struct got_worktree *worktree,
1117     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
1118     struct got_tree_entry *te, const char *path,
1119     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1120     void *progress_arg)
1121 {
1122 	const struct got_error *err = NULL;
1123 	struct got_blob_object *blob = NULL;
1124 	char *ondisk_path;
1125 	unsigned char status = GOT_STATUS_NO_CHANGE;
1126 	struct stat sb;
1127 
1128 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
1129 		return got_error_prefix_errno("asprintf");
1130 
1131 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1132 	if (err)
1133 		goto done;
1134 
1135 	if (status == GOT_STATUS_OBSTRUCTED) {
1136 		(*progress_cb)(progress_arg, status, path);
1137 		goto done;
1138 	}
1139 
1140 	if (ie && status != GOT_STATUS_MISSING) {
1141 		if (got_fileindex_entry_has_commit(ie) &&
1142 		    memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
1143 		    SHA1_DIGEST_LENGTH) == 0) {
1144 			(*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
1145 			    path);
1146 			goto done;
1147 		}
1148 		if (got_fileindex_entry_has_blob(ie) &&
1149 		    memcmp(ie->blob_sha1, te->id->sha1,
1150 		    SHA1_DIGEST_LENGTH) == 0)
1151 			goto done;
1152 	}
1153 
1154 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
1155 	if (err)
1156 		goto done;
1157 
1158 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_ADD)
1159 		err = merge_blob(worktree, fileindex, ie, ondisk_path, path,
1160 		    te->mode, sb.st_mode, blob, repo, progress_cb,
1161 		    progress_arg);
1162 	else if (status == GOT_STATUS_DELETE) {
1163 		(*progress_cb)(progress_arg, GOT_STATUS_MERGE, path);
1164 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1165 		    ondisk_path, path, blob, 0);
1166 		if (err)
1167 			goto done;
1168 	} else {
1169 		err = install_blob(worktree, ondisk_path, path, te->mode,
1170 		    sb.st_mode, blob, status == GOT_STATUS_MISSING, 0,
1171 		    repo, progress_cb, progress_arg);
1172 		if (err)
1173 			goto done;
1174 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1175 		    ondisk_path, path, blob, 1);
1176 		if (err)
1177 			goto done;
1178 	}
1179 	got_object_blob_close(blob);
1180 done:
1181 	free(ondisk_path);
1182 	return err;
1183 }
1184 
1185 static const struct got_error *
1186 remove_ondisk_file(const char *root_path, const char *path)
1187 {
1188 	const struct got_error *err = NULL;
1189 	char *ondisk_path = NULL;
1190 
1191 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
1192 		return got_error_prefix_errno("asprintf");
1193 
1194 	if (unlink(ondisk_path) == -1) {
1195 		if (errno != ENOENT)
1196 			err = got_error_prefix_errno2("unlink", ondisk_path);
1197 	} else {
1198 		char *parent = dirname(ondisk_path);
1199 		while (parent && strcmp(parent, root_path) != 0) {
1200 			if (rmdir(parent) == -1) {
1201 				if (errno != ENOTEMPTY)
1202 					err = got_error_prefix_errno2("rmdir",
1203 					    parent);
1204 				break;
1205 			}
1206 			parent = dirname(parent);
1207 		}
1208 	}
1209 	free(ondisk_path);
1210 	return err;
1211 }
1212 
1213 static const struct got_error *
1214 delete_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
1215     struct got_fileindex_entry *ie, const char *parent_path,
1216     struct got_repository *repo,
1217     got_worktree_checkout_cb progress_cb, void *progress_arg)
1218 {
1219 	const struct got_error *err = NULL;
1220 	unsigned char status;
1221 	struct stat sb;
1222 	char *ondisk_path;
1223 
1224 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, ie->path)
1225 	    == -1)
1226 		return got_error_prefix_errno("asprintf");
1227 
1228 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1229 	if (err)
1230 		return err;
1231 
1232 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_CONFLICT ||
1233 	    status == GOT_STATUS_ADD) {
1234 		(*progress_cb)(progress_arg, GOT_STATUS_MERGE, ie->path);
1235 		/*
1236 		 * Preserve the working file and change the deleted blob's
1237 		 * entry into a schedule-add entry.
1238 		 */
1239 		err = got_fileindex_entry_update(ie, ondisk_path, NULL, NULL,
1240 		    0);
1241 		if (err)
1242 			return err;
1243 	} else {
1244 		(*progress_cb)(progress_arg, GOT_STATUS_DELETE, ie->path);
1245 		if (status == GOT_STATUS_NO_CHANGE) {
1246 			err = remove_ondisk_file(worktree->root_path, ie->path);
1247 			if (err)
1248 				return err;
1249 		}
1250 		got_fileindex_entry_remove(fileindex, ie);
1251 	}
1252 
1253 	return err;
1254 }
1255 
1256 struct diff_cb_arg {
1257     struct got_fileindex *fileindex;
1258     struct got_worktree *worktree;
1259     struct got_repository *repo;
1260     got_worktree_checkout_cb progress_cb;
1261     void *progress_arg;
1262     got_worktree_cancel_cb cancel_cb;
1263     void *cancel_arg;
1264 };
1265 
1266 static const struct got_error *
1267 diff_old_new(void *arg, struct got_fileindex_entry *ie,
1268     struct got_tree_entry *te, const char *parent_path)
1269 {
1270 	struct diff_cb_arg *a = arg;
1271 
1272 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1273 		return got_error(GOT_ERR_CANCELLED);
1274 
1275 	return update_blob(a->worktree, a->fileindex, ie, te,
1276 	    ie->path, a->repo, a->progress_cb, a->progress_arg);
1277 }
1278 
1279 static const struct got_error *
1280 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1281 {
1282 	struct diff_cb_arg *a = arg;
1283 
1284 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1285 		return got_error(GOT_ERR_CANCELLED);
1286 
1287 	return delete_blob(a->worktree, a->fileindex, ie, parent_path,
1288 	    a->repo, a->progress_cb, a->progress_arg);
1289 }
1290 
1291 static const struct got_error *
1292 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
1293 {
1294 	struct diff_cb_arg *a = arg;
1295 	const struct got_error *err;
1296 	char *path;
1297 
1298 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1299 		return got_error(GOT_ERR_CANCELLED);
1300 
1301 	if (asprintf(&path, "%s%s%s", parent_path,
1302 	    parent_path[0] ? "/" : "", te->name)
1303 	    == -1)
1304 		return got_error_prefix_errno("asprintf");
1305 
1306 	if (S_ISDIR(te->mode))
1307 		err = add_dir_on_disk(a->worktree, path);
1308 	else
1309 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
1310 		    a->repo, a->progress_cb, a->progress_arg);
1311 
1312 	free(path);
1313 	return err;
1314 }
1315 
1316 const struct got_error *
1317 got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
1318 {
1319 	const struct got_error *err = NULL;
1320 	char *uuidstr = NULL;
1321 	uint32_t uuid_status;
1322 
1323 	*refname = NULL;
1324 
1325 	uuid_to_string(&worktree->uuid, &uuidstr, &uuid_status);
1326 	if (uuid_status != uuid_s_ok)
1327 		return got_error_uuid(uuid_status);
1328 
1329 	if (asprintf(refname, "%s-%s", GOT_WORKTREE_BASE_REF_PREFIX, uuidstr)
1330 	    == -1) {
1331 		err = got_error_prefix_errno("asprintf");
1332 		*refname = NULL;
1333 	}
1334 	free(uuidstr);
1335 	return err;
1336 }
1337 
1338 /*
1339  * Prevent Git's garbage collector from deleting our base commit by
1340  * setting a reference to our base commit's ID.
1341  */
1342 static const struct got_error *
1343 ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
1344 {
1345 	const struct got_error *err = NULL;
1346 	struct got_reference *ref = NULL;
1347 	char *refname;
1348 
1349 	err = got_worktree_get_base_ref_name(&refname, worktree);
1350 	if (err)
1351 		return err;
1352 
1353 	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
1354 	if (err)
1355 		goto done;
1356 
1357 	err = got_ref_write(ref, repo);
1358 done:
1359 	free(refname);
1360 	if (ref)
1361 		got_ref_close(ref);
1362 	return err;
1363 }
1364 
1365 static const struct got_error *
1366 open_fileindex(struct got_fileindex **fileindex, char **fileindex_path,
1367    struct got_worktree *worktree)
1368 {
1369 	const struct got_error *err = NULL;
1370 	FILE *index = NULL;
1371 
1372 	*fileindex_path = NULL;
1373 	*fileindex = got_fileindex_alloc();
1374 	if (*fileindex == NULL)
1375 		return got_error_prefix_errno("got_fileindex_alloc");
1376 
1377 	if (asprintf(fileindex_path, "%s/%s/%s", worktree->root_path,
1378 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1379 		err = got_error_prefix_errno("asprintf");
1380 		*fileindex_path = NULL;
1381 		goto done;
1382 	}
1383 
1384 	index = fopen(*fileindex_path, "rb");
1385 	if (index == NULL) {
1386 		if (errno != ENOENT)
1387 			err = got_error_prefix_errno2("fopen", *fileindex_path);
1388 	} else {
1389 		err = got_fileindex_read(*fileindex, index);
1390 		if (fclose(index) != 0 && err == NULL)
1391 			err = got_error_prefix_errno("fclose");
1392 	}
1393 done:
1394 	if (err) {
1395 		free(*fileindex_path);
1396 		*fileindex_path = NULL;
1397 		free(*fileindex);
1398 		*fileindex = NULL;
1399 	}
1400 	return err;
1401 }
1402 
1403 const struct got_error *
1404 got_worktree_checkout_files(struct got_worktree *worktree, const char *path,
1405     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1406     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1407 {
1408 	const struct got_error *err = NULL, *unlockerr, *checkout_err = NULL;
1409 	struct got_commit_object *commit = NULL;
1410 	struct got_object_id *tree_id = NULL;
1411 	struct got_tree_object *tree = NULL;
1412 	char *fileindex_path = NULL, *new_fileindex_path = NULL;
1413 	struct got_fileindex *fileindex = NULL;
1414 	FILE *new_index = NULL;
1415 	struct got_fileindex_diff_tree_cb diff_cb;
1416 	struct diff_cb_arg arg;
1417 	char *relpath = NULL, *entry_name = NULL;
1418 
1419 	err = lock_worktree(worktree, LOCK_EX);
1420 	if (err)
1421 		return err;
1422 
1423 	/*
1424 	 * Read the file index.
1425 	 * Checking out files is supposed to be an idempotent operation.
1426 	 * If the on-disk file index is incomplete we will try to complete it.
1427 	 */
1428 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1429 	if (err)
1430 		goto done;
1431 
1432 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1433 	    fileindex_path);
1434 	if (err)
1435 		goto done;
1436 
1437 	err = ref_base_commit(worktree, repo);
1438 	if (err)
1439 		goto done;
1440 
1441 	err = got_object_open_as_commit(&commit, repo,
1442 	   worktree->base_commit_id);
1443 	if (err)
1444 		goto done;
1445 
1446 	if (path[0]) {
1447 		char *tree_path;
1448 		int obj_type;
1449 		relpath = strdup(path);
1450 		if (relpath == NULL) {
1451 			err = got_error_prefix_errno("strdup");
1452 			goto done;
1453 		}
1454 		if (asprintf(&tree_path, "%s%s%s", worktree->path_prefix,
1455 		    got_path_is_root_dir(worktree->path_prefix) ? "" : "/",
1456 		    path) == -1) {
1457 			err = got_error_prefix_errno("asprintf");
1458 			goto done;
1459 		}
1460 		err = got_object_id_by_path(&tree_id, repo,
1461 		    worktree->base_commit_id, tree_path);
1462 		free(tree_path);
1463 		if (err)
1464 			goto done;
1465 		err = got_object_get_type(&obj_type, repo, tree_id);
1466 		if (err)
1467 			goto done;
1468 		if (obj_type == GOT_OBJ_TYPE_BLOB) {
1469 			/* Split provided path into parent dir + entry name. */
1470 			if (strchr(path, '/')  == NULL) {
1471 				relpath = strdup("");
1472 				if (relpath == NULL) {
1473 					err = got_error_prefix_errno("strdup");
1474 					goto done;
1475 				}
1476 				tree_path = strdup(worktree->path_prefix);
1477 				if (tree_path == NULL) {
1478 					err = got_error_prefix_errno("strdup");
1479 					goto done;
1480 				}
1481 			} else {
1482 				err = got_path_dirname(&relpath, path);
1483 				if (err)
1484 					goto done;
1485 				if (asprintf(&tree_path, "%s%s%s",
1486 				    worktree->path_prefix,
1487 				    got_path_is_root_dir(
1488 				    worktree->path_prefix) ? "" : "/",
1489 				    relpath) == -1) {
1490 					err = got_error_prefix_errno("asprintf");
1491 					goto done;
1492 				}
1493 			}
1494 			err = got_object_id_by_path(&tree_id, repo,
1495 			    worktree->base_commit_id, tree_path);
1496 			free(tree_path);
1497 			if (err)
1498 				goto done;
1499 			entry_name = basename(path);
1500 			if (entry_name == NULL) {
1501 				err = got_error_prefix_errno2("basename", path);
1502 				goto done;
1503 			}
1504 		}
1505 	} else {
1506 		relpath = strdup("");
1507 		if (relpath == NULL) {
1508 			err = got_error_prefix_errno("strdup");
1509 			goto done;
1510 		}
1511 		err = got_object_id_by_path(&tree_id, repo,
1512 		    worktree->base_commit_id, worktree->path_prefix);
1513 		if (err)
1514 			goto done;
1515 	}
1516 
1517 	err = got_object_open_as_tree(&tree, repo, tree_id);
1518 	if (err)
1519 		goto done;
1520 
1521 	if (entry_name &&
1522 	    got_object_tree_find_entry(tree, entry_name) == NULL) {
1523 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
1524 		goto done;
1525 	}
1526 
1527 	diff_cb.diff_old_new = diff_old_new;
1528 	diff_cb.diff_old = diff_old;
1529 	diff_cb.diff_new = diff_new;
1530 	arg.fileindex = fileindex;
1531 	arg.worktree = worktree;
1532 	arg.repo = repo;
1533 	arg.progress_cb = progress_cb;
1534 	arg.progress_arg = progress_arg;
1535 	arg.cancel_cb = cancel_cb;
1536 	arg.cancel_arg = cancel_arg;
1537 	checkout_err = got_fileindex_diff_tree(fileindex, tree, relpath,
1538 	    entry_name, repo, &diff_cb, &arg);
1539 
1540 	/* Try to sync the fileindex back to disk in any case. */
1541 	err = got_fileindex_write(fileindex, new_index);
1542 	if (err)
1543 		goto done;
1544 
1545 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1546 		err = got_error_prefix_errno3("rename", new_fileindex_path,
1547 		    fileindex_path);
1548 		unlink(new_fileindex_path);
1549 		goto done;
1550 	}
1551 
1552 	free(new_fileindex_path);
1553 	new_fileindex_path = NULL;
1554 
1555 done:
1556 	free(relpath);
1557 	if (tree)
1558 		got_object_tree_close(tree);
1559 	if (commit)
1560 		got_object_commit_close(commit);
1561 	if (new_fileindex_path)
1562 		unlink(new_fileindex_path);
1563 	if (new_index)
1564 		fclose(new_index);
1565 	free(new_fileindex_path);
1566 	free(fileindex_path);
1567 	got_fileindex_free(fileindex);
1568 	if (checkout_err)
1569 		err = checkout_err;
1570 	unlockerr = lock_worktree(worktree, LOCK_SH);
1571 	if (unlockerr && err == NULL)
1572 		err = unlockerr;
1573 	return err;
1574 }
1575 
1576 struct diff_dir_cb_arg {
1577     struct got_fileindex *fileindex;
1578     struct got_worktree *worktree;
1579     const char *status_path;
1580     size_t status_path_len;
1581     struct got_repository *repo;
1582     got_worktree_status_cb status_cb;
1583     void *status_arg;
1584     got_worktree_cancel_cb cancel_cb;
1585     void *cancel_arg;
1586 };
1587 
1588 static const struct got_error *
1589 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
1590     got_worktree_status_cb status_cb, void *status_arg,
1591     struct got_repository *repo)
1592 {
1593 	const struct got_error *err = NULL;
1594 	unsigned char status = GOT_STATUS_NO_CHANGE;
1595 	struct stat sb;
1596 	struct got_object_id id;
1597 
1598 	err = get_file_status(&status, &sb, ie, abspath, repo);
1599 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
1600 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1601 		err = (*status_cb)(status_arg, status, ie->path, &id);
1602 	}
1603 	return err;
1604 }
1605 
1606 static const struct got_error *
1607 status_old_new(void *arg, struct got_fileindex_entry *ie,
1608     struct dirent *de, const char *parent_path)
1609 {
1610 	const struct got_error *err = NULL;
1611 	struct diff_dir_cb_arg *a = arg;
1612 	char *abspath;
1613 
1614 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1615 		return got_error(GOT_ERR_CANCELLED);
1616 
1617 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
1618 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
1619 		return NULL;
1620 
1621 	if (parent_path[0]) {
1622 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
1623 		    parent_path, de->d_name) == -1)
1624 			return got_error_prefix_errno("asprintf");
1625 	} else {
1626 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
1627 		    de->d_name) == -1)
1628 			return got_error_prefix_errno("asprintf");
1629 	}
1630 
1631 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
1632 	    a->repo);
1633 	free(abspath);
1634 	return err;
1635 }
1636 
1637 static const struct got_error *
1638 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1639 {
1640 	struct diff_dir_cb_arg *a = arg;
1641 	struct got_object_id id;
1642 	unsigned char status;
1643 
1644 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1645 		return got_error(GOT_ERR_CANCELLED);
1646 
1647 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
1648 		return NULL;
1649 
1650 	memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1651 	if (got_fileindex_entry_has_file_on_disk(ie))
1652 		status = GOT_STATUS_MISSING;
1653 	else
1654 		status = GOT_STATUS_DELETE;
1655 	return (*a->status_cb)(a->status_arg, status, ie->path, &id);
1656 }
1657 
1658 static const struct got_error *
1659 status_new(void *arg, struct dirent *de, const char *parent_path)
1660 {
1661 	const struct got_error *err = NULL;
1662 	struct diff_dir_cb_arg *a = arg;
1663 	char *path = NULL;
1664 
1665 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1666 		return got_error(GOT_ERR_CANCELLED);
1667 
1668 	if (de->d_type == DT_DIR)
1669 		return NULL;
1670 
1671 	/* XXX ignore symlinks for now */
1672 	if (de->d_type == DT_LNK)
1673 		return NULL;
1674 
1675 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
1676 		return NULL;
1677 
1678 	if (parent_path[0]) {
1679 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
1680 			return got_error_prefix_errno("asprintf");
1681 	} else {
1682 		path = de->d_name;
1683 	}
1684 
1685 	err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED, path,
1686 	    NULL);
1687 	if (parent_path[0])
1688 		free(path);
1689 	return err;
1690 }
1691 
1692 const struct got_error *
1693 got_worktree_status(struct got_worktree *worktree, const char *path,
1694     struct got_repository *repo, got_worktree_status_cb status_cb,
1695     void *status_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1696 {
1697 	const struct got_error *err = NULL;
1698 	DIR *workdir = NULL;
1699 	char *fileindex_path = NULL;
1700 	struct got_fileindex *fileindex = NULL;
1701 	FILE *index = NULL;
1702 	struct got_fileindex_diff_dir_cb fdiff_cb;
1703 	struct diff_dir_cb_arg arg;
1704 	char *ondisk_path = NULL;
1705 
1706 	fileindex = got_fileindex_alloc();
1707 	if (fileindex == NULL) {
1708 		err = got_error_prefix_errno("got_fileindex_alloc");
1709 		goto done;
1710 	}
1711 
1712 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
1713 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1714 		err = got_error_prefix_errno("asprintf");
1715 		fileindex_path = NULL;
1716 		goto done;
1717 	}
1718 
1719 	index = fopen(fileindex_path, "rb");
1720 	if (index == NULL) {
1721 		if (errno != ENOENT) {
1722 			err = got_error_prefix_errno2("fopen", fileindex_path);
1723 			goto done;
1724 		}
1725 	} else {
1726 		err = got_fileindex_read(fileindex, index);
1727 		fclose(index);
1728 		if (err)
1729 			goto done;
1730 	}
1731 
1732 	if (asprintf(&ondisk_path, "%s%s%s",
1733 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
1734 		err = got_error_prefix_errno("asprintf");
1735 		goto done;
1736 	}
1737 	workdir = opendir(ondisk_path);
1738 	if (workdir == NULL) {
1739 		if (errno == ENOTDIR || errno == ENOENT) {
1740 			struct got_fileindex_entry *ie;
1741 			ie = got_fileindex_entry_get(fileindex, path);
1742 			if (ie == NULL) {
1743 				err = got_error(GOT_ERR_BAD_PATH);
1744 				goto done;
1745 			}
1746 			err = report_file_status(ie, ondisk_path,
1747 			    status_cb, status_arg, repo);
1748 			goto done;
1749 		} else {
1750 			err = got_error_prefix_errno2("opendir", ondisk_path);
1751 			goto done;
1752 		}
1753 	}
1754 	fdiff_cb.diff_old_new = status_old_new;
1755 	fdiff_cb.diff_old = status_old;
1756 	fdiff_cb.diff_new = status_new;
1757 	arg.fileindex = fileindex;
1758 	arg.worktree = worktree;
1759 	arg.status_path = path;
1760 	arg.status_path_len = strlen(path);
1761 	arg.repo = repo;
1762 	arg.status_cb = status_cb;
1763 	arg.status_arg = status_arg;
1764 	arg.cancel_cb = cancel_cb;
1765 	arg.cancel_arg = cancel_arg;
1766 	err = got_fileindex_diff_dir(fileindex, workdir, worktree->root_path,
1767 	    path, repo, &fdiff_cb, &arg);
1768 done:
1769 	if (workdir)
1770 		closedir(workdir);
1771 	free(ondisk_path);
1772 	free(fileindex_path);
1773 	got_fileindex_free(fileindex);
1774 	return err;
1775 }
1776 
1777 const struct got_error *
1778 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
1779     const char *arg)
1780 {
1781 	const struct got_error *err = NULL;
1782 	char *resolved, *path = NULL;
1783 	size_t len;
1784 
1785 	*wt_path = NULL;
1786 
1787 	resolved = realpath(arg, NULL);
1788 	if (resolved == NULL)
1789 		return got_error_prefix_errno2("realpath", arg);
1790 
1791 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
1792 	    strlen(got_worktree_get_root_path(worktree)))) {
1793 		err = got_error(GOT_ERR_BAD_PATH);
1794 		goto done;
1795 	}
1796 
1797 	path = strdup(resolved +
1798 	    strlen(got_worktree_get_root_path(worktree)) + 1 /* skip '/' */);
1799 	if (path == NULL) {
1800 		err = got_error_prefix_errno("strdup");
1801 		goto done;
1802 	}
1803 
1804 	/* XXX status walk can't deal with trailing slash! */
1805 	len = strlen(path);
1806 	while (path[len - 1] == '/') {
1807 		path[len - 1] = '\0';
1808 		len--;
1809 	}
1810 done:
1811 	free(resolved);
1812 	if (err == NULL)
1813 		*wt_path = path;
1814 	else
1815 		free(path);
1816 	return err;
1817 }
1818 
1819 const struct got_error *
1820 got_worktree_schedule_add(struct got_worktree *worktree,
1821     const char *ondisk_path, got_worktree_status_cb status_cb, void *status_arg,
1822     struct got_repository *repo)
1823 {
1824 	struct got_fileindex *fileindex = NULL;
1825 	struct got_fileindex_entry *ie = NULL;
1826 	char *relpath, *fileindex_path = NULL, *new_fileindex_path = NULL;
1827 	FILE *index = NULL, *new_index = NULL;
1828 	const struct got_error *err = NULL, *unlockerr = NULL;
1829 	int ie_added = 0;
1830 
1831 	err = lock_worktree(worktree, LOCK_EX);
1832 	if (err)
1833 		return err;
1834 
1835 	err = got_path_skip_common_ancestor(&relpath,
1836 	    got_worktree_get_root_path(worktree), ondisk_path);
1837 	if (err)
1838 		goto done;
1839 
1840 	fileindex = got_fileindex_alloc();
1841 	if (fileindex == NULL) {
1842 		err = got_error_prefix_errno("got_fileindex_alloc");
1843 		goto done;
1844 	}
1845 
1846 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
1847 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1848 		err = got_error_prefix_errno("asprintf");
1849 		fileindex_path = NULL;
1850 		goto done;
1851 	}
1852 
1853 	index = fopen(fileindex_path, "rb");
1854 	if (index == NULL) {
1855 		err = got_error_prefix_errno2("fopen", fileindex_path);
1856 		goto done;
1857 	}
1858 
1859 	err = got_fileindex_read(fileindex, index);
1860 	if (err)
1861 		goto done;
1862 
1863 	if (got_fileindex_entry_get(fileindex, relpath) != NULL) {
1864 		err = got_error_set_errno(EEXIST);
1865 		goto done;
1866 	}
1867 
1868 	err = got_fileindex_entry_alloc(&ie, ondisk_path, relpath, NULL, NULL);
1869 	if (err)
1870 		goto done;
1871 
1872 	err = got_fileindex_entry_add(fileindex, ie);
1873 	if (err)
1874 		goto done;
1875 	ie_added = 1; /* now owned by fileindex; don't free separately */
1876 
1877 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1878 	    fileindex_path);
1879 	if (err)
1880 		goto done;
1881 
1882 	err = got_fileindex_write(fileindex, new_index);
1883 	if (err)
1884 		goto done;
1885 
1886 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1887 		err = got_error_prefix_errno3("rename", new_fileindex_path,
1888 		    fileindex_path);
1889 		goto done;
1890 	}
1891 
1892 	free(new_fileindex_path);
1893 	new_fileindex_path = NULL;
1894 
1895 	err = report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
1896 done:
1897 	if (index) {
1898 		if (fclose(index) != 0 && err == NULL)
1899 			err = got_error_prefix_errno("fclose");
1900 	}
1901 	if (new_fileindex_path) {
1902 		if (unlink(new_fileindex_path) != 0 && err == NULL)
1903 			err = got_error_prefix_errno2("unlink",
1904 			    new_fileindex_path);
1905 		free(new_fileindex_path);
1906 	}
1907 	if (ie && !ie_added)
1908 		got_fileindex_entry_free(ie);
1909 	if (fileindex)
1910 		got_fileindex_free(fileindex);
1911 	unlockerr = lock_worktree(worktree, LOCK_SH);
1912 	if (unlockerr && err == NULL)
1913 		err = unlockerr;
1914 	free(relpath);
1915 	return err;
1916 }
1917 
1918 const struct got_error *
1919 got_worktree_schedule_delete(struct got_worktree *worktree,
1920     const char *ondisk_path, int delete_local_mods,
1921     got_worktree_status_cb status_cb, void *status_arg,
1922     struct got_repository *repo)
1923 {
1924 	struct got_fileindex *fileindex = NULL;
1925 	struct got_fileindex_entry *ie = NULL;
1926 	char *relpath, *fileindex_path = NULL, *new_fileindex_path = NULL;
1927 	FILE *index = NULL, *new_index = NULL;
1928 	const struct got_error *err = NULL, *unlockerr = NULL;
1929 	unsigned char status;
1930 	struct stat sb;
1931 
1932 	err = lock_worktree(worktree, LOCK_EX);
1933 	if (err)
1934 		return err;
1935 
1936 	err = got_path_skip_common_ancestor(&relpath,
1937 	    got_worktree_get_root_path(worktree), ondisk_path);
1938 	if (err)
1939 		goto done;
1940 
1941 	fileindex = got_fileindex_alloc();
1942 	if (fileindex == NULL) {
1943 		err = got_error_prefix_errno("got_fileindex_alloc");
1944 		goto done;
1945 	}
1946 
1947 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
1948 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1949 		err = got_error_prefix_errno("asprintf");
1950 		fileindex_path = NULL;
1951 		goto done;
1952 	}
1953 
1954 	index = fopen(fileindex_path, "rb");
1955 	if (index == NULL) {
1956 		err = got_error_prefix_errno2("fopen", fileindex_path);
1957 		goto done;
1958 	}
1959 
1960 	err = got_fileindex_read(fileindex, index);
1961 	if (err)
1962 		goto done;
1963 
1964 	ie = got_fileindex_entry_get(fileindex, relpath);
1965 	if (ie == NULL) {
1966 		err = got_error(GOT_ERR_BAD_PATH);
1967 		goto done;
1968 	}
1969 
1970 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1971 	if (err)
1972 		goto done;
1973 
1974 	if (status != GOT_STATUS_NO_CHANGE) {
1975 		if (status == GOT_STATUS_DELETE) {
1976 			err = got_error_set_errno(ENOENT);
1977 			goto done;
1978 		}
1979 		if (status != GOT_STATUS_MODIFY) {
1980 			err = got_error(GOT_ERR_FILE_STATUS);
1981 			goto done;
1982 		}
1983 		if (!delete_local_mods) {
1984 			err = got_error(GOT_ERR_FILE_MODIFIED);
1985 			goto done;
1986 		}
1987 	}
1988 
1989 	if (unlink(ondisk_path) != 0) {
1990 		err = got_error_prefix_errno2("unlink", ondisk_path);
1991 		goto done;
1992 	}
1993 
1994 	got_fileindex_entry_mark_deleted_from_disk(ie);
1995 
1996 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1997 	    fileindex_path);
1998 	if (err)
1999 		goto done;
2000 
2001 	err = got_fileindex_write(fileindex, new_index);
2002 	if (err)
2003 		goto done;
2004 
2005 	if (rename(new_fileindex_path, fileindex_path) != 0) {
2006 		err = got_error_prefix_errno3("rename", new_fileindex_path,
2007 		    fileindex_path);
2008 		goto done;
2009 	}
2010 
2011 	free(new_fileindex_path);
2012 	new_fileindex_path = NULL;
2013 
2014 	err = report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2015 done:
2016 	free(relpath);
2017 	if (index) {
2018 		if (fclose(index) != 0 && err == NULL)
2019 			err = got_error_prefix_errno("fclose");
2020 	}
2021 	if (new_fileindex_path) {
2022 		if (unlink(new_fileindex_path) != 0 && err == NULL)
2023 			err = got_error_prefix_errno2("unlink",
2024 			    new_fileindex_path);
2025 		free(new_fileindex_path);
2026 	}
2027 	if (fileindex)
2028 		got_fileindex_free(fileindex);
2029 	unlockerr = lock_worktree(worktree, LOCK_SH);
2030 	if (unlockerr && err == NULL)
2031 		err = unlockerr;
2032 	return err;
2033 }
2034 
2035 const struct got_error *
2036 got_worktree_revert(struct got_worktree *worktree,
2037     const char *ondisk_path,
2038     got_worktree_checkout_cb progress_cb, void *progress_arg,
2039     struct got_repository *repo)
2040 {
2041 	struct got_fileindex *fileindex = NULL;
2042 	struct got_fileindex_entry *ie = NULL;
2043 	char *relpath, *fileindex_path = NULL, *new_fileindex_path = NULL;
2044 	char *tree_path = NULL, *parent_path, *te_name;
2045 	FILE *index = NULL, *new_index = NULL;
2046 	const struct got_error *err = NULL, *unlockerr = NULL;
2047 	struct got_tree_object *tree = NULL;
2048 	struct got_object_id id, *tree_id = NULL;
2049 	const struct got_tree_entry *te;
2050 	struct got_blob_object *blob = NULL;
2051 	unsigned char status;
2052 	struct stat sb;
2053 
2054 	err = lock_worktree(worktree, LOCK_EX);
2055 	if (err)
2056 		return err;
2057 
2058 	err = got_path_skip_common_ancestor(&relpath,
2059 	    got_worktree_get_root_path(worktree), ondisk_path);
2060 	if (err)
2061 		goto done;
2062 
2063 	fileindex = got_fileindex_alloc();
2064 	if (fileindex == NULL) {
2065 		err = got_error_prefix_errno("got_fileindex_alloc");
2066 		goto done;
2067 	}
2068 
2069 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
2070 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
2071 		err = got_error_prefix_errno("asprintf");
2072 		fileindex_path = NULL;
2073 		goto done;
2074 	}
2075 
2076 	index = fopen(fileindex_path, "rb");
2077 	if (index == NULL) {
2078 		err = got_error_prefix_errno2("fopen", fileindex_path);
2079 		goto done;
2080 	}
2081 
2082 	err = got_fileindex_read(fileindex, index);
2083 	if (err)
2084 		goto done;
2085 
2086 	ie = got_fileindex_entry_get(fileindex, relpath);
2087 	if (ie == NULL) {
2088 		err = got_error(GOT_ERR_BAD_PATH);
2089 		goto done;
2090 	}
2091 
2092 	/* Construct in-repository path of tree which contains this blob. */
2093 	err = got_path_dirname(&parent_path, ie->path);
2094 	if (err) {
2095 		if (err->code != GOT_ERR_BAD_PATH)
2096 			goto done;
2097 		parent_path = "/";
2098 	}
2099 	if (got_path_is_root_dir(worktree->path_prefix)) {
2100 		tree_path = strdup(parent_path);
2101 		if (tree_path == NULL) {
2102 			err = got_error_prefix_errno("strdup");
2103 			goto done;
2104 		}
2105 	} else {
2106 		if (got_path_is_root_dir(parent_path)) {
2107 			tree_path = strdup(worktree->path_prefix);
2108 			if (tree_path == NULL) {
2109 				err = got_error_prefix_errno("strdup");
2110 				goto done;
2111 			}
2112 		} else {
2113 			if (asprintf(&tree_path, "%s/%s",
2114 			    worktree->path_prefix, parent_path) == -1) {
2115 				err = got_error_prefix_errno("asprintf");
2116 				goto done;
2117 			}
2118 		}
2119 	}
2120 
2121 	err = got_object_id_by_path(&tree_id, repo, worktree->base_commit_id,
2122 	    tree_path);
2123 	if (err)
2124 		goto done;
2125 
2126 	err = got_object_open_as_tree(&tree, repo, tree_id);
2127 	if (err)
2128 		goto done;
2129 
2130 	te_name = basename(ie->path);
2131 	if (te_name == NULL) {
2132 		err = got_error_prefix_errno2("basename", ie->path);
2133 		goto done;
2134 	}
2135 
2136 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2137 	if (err)
2138 		goto done;
2139 
2140 	te = got_object_tree_find_entry(tree, te_name);
2141 	if (te == NULL && status != GOT_STATUS_ADD) {
2142 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
2143 		goto done;
2144 	}
2145 
2146 	switch (status) {
2147 	case GOT_STATUS_ADD:
2148 		(*progress_cb)(progress_arg, GOT_STATUS_REVERT, ie->path);
2149 		got_fileindex_entry_remove(fileindex, ie);
2150 		break;
2151 	case GOT_STATUS_DELETE:
2152 	case GOT_STATUS_MODIFY:
2153 	case GOT_STATUS_CONFLICT:
2154 	case GOT_STATUS_MISSING:
2155 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2156 		err = got_object_open_as_blob(&blob, repo, &id, 8192);
2157 		if (err)
2158 			goto done;
2159 		err = install_blob(worktree, ondisk_path, ie->path,
2160 		    te->mode, sb.st_mode, blob, 0, 1, repo, progress_cb,
2161 		    progress_arg);
2162 		if (err)
2163 			goto done;
2164 		if (status == GOT_STATUS_DELETE) {
2165 			err = update_blob_fileindex_entry(worktree,
2166 			    fileindex, ie, ondisk_path, ie->path, blob, 1);
2167 			if (err)
2168 				goto done;
2169 		}
2170 		break;
2171 	default:
2172 			goto done;
2173 	}
2174 
2175 	err = got_opentemp_named(&new_fileindex_path, &new_index,
2176 	    fileindex_path);
2177 	if (err)
2178 		goto done;
2179 
2180 	err = got_fileindex_write(fileindex, new_index);
2181 	if (err)
2182 		goto done;
2183 
2184 	if (rename(new_fileindex_path, fileindex_path) != 0) {
2185 		err = got_error_prefix_errno3("rename", new_fileindex_path,
2186 		    fileindex_path);
2187 		goto done;
2188 	}
2189 
2190 	free(new_fileindex_path);
2191 	new_fileindex_path = NULL;
2192 done:
2193 	free(relpath);
2194 	free(tree_path);
2195 	if (blob)
2196 		got_object_blob_close(blob);
2197 	if (tree)
2198 		got_object_tree_close(tree);
2199 	free(tree_id);
2200 	if (index) {
2201 		if (fclose(index) != 0 && err == NULL)
2202 			err = got_error_prefix_errno("fclose");
2203 	}
2204 	if (new_fileindex_path) {
2205 		if (unlink(new_fileindex_path) != 0 && err == NULL)
2206 			err = got_error_prefix_errno2("unlink",
2207 			    new_fileindex_path);
2208 		free(new_fileindex_path);
2209 	}
2210 	if (fileindex)
2211 		got_fileindex_free(fileindex);
2212 	unlockerr = lock_worktree(worktree, LOCK_SH);
2213 	if (unlockerr && err == NULL)
2214 		err = unlockerr;
2215 	return err;
2216 }
2217 
2218 struct commitable {
2219 	char *path;
2220 	char *in_repo_path;
2221 	char *ondisk_path;
2222 	unsigned char status;
2223 	struct got_object_id *blob_id;
2224 	struct got_object_id *base_id;
2225 	mode_t mode;
2226 };
2227 
2228 static void
2229 free_commitable(struct commitable *ct)
2230 {
2231 	free(ct->path);
2232 	free(ct->in_repo_path);
2233 	free(ct->ondisk_path);
2234 	free(ct->blob_id);
2235 	free(ct->base_id);
2236 	free(ct);
2237 }
2238 
2239 struct collect_commitables_arg {
2240 	struct got_pathlist_head *commitable_paths;
2241 	struct got_repository *repo;
2242 	struct got_worktree *worktree;
2243 };
2244 
2245 static const struct got_error *
2246 collect_commitables(void *arg, unsigned char status, const char *relpath,
2247     struct got_object_id *id)
2248 {
2249 	struct collect_commitables_arg *a = arg;
2250 	const struct got_error *err = NULL;
2251 	struct commitable *ct = NULL;
2252 	struct got_pathlist_entry *new = NULL;
2253 	char *parent_path = NULL, *path = NULL;
2254 	struct stat sb;
2255 
2256 	if (status == GOT_STATUS_CONFLICT)
2257 		return got_error(GOT_ERR_COMMIT_CONFLICT);
2258 
2259 	if (status != GOT_STATUS_MODIFY && status != GOT_STATUS_ADD &&
2260 	    status != GOT_STATUS_DELETE)
2261 		return NULL;
2262 
2263 	if (asprintf(&path, "/%s", relpath) == -1) {
2264 		err = got_error_prefix_errno("asprintf");
2265 		goto done;
2266 	}
2267 	if (strcmp(path, "/") == 0) {
2268 		parent_path = strdup("");
2269 		if (parent_path == NULL)
2270 			return got_error_prefix_errno("strdup");
2271 	} else {
2272 		err = got_path_dirname(&parent_path, path);
2273 		if (err)
2274 			return err;
2275 	}
2276 
2277 	ct = calloc(1, sizeof(*ct));
2278 	if (ct == NULL) {
2279 		err = got_error_prefix_errno("calloc");
2280 		goto done;
2281 	}
2282 
2283 	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
2284 	    relpath) == -1) {
2285 		err = got_error_prefix_errno("asprintf");
2286 		goto done;
2287 	}
2288 	if (status == GOT_STATUS_DELETE) {
2289 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
2290 	} else {
2291 		if (lstat(ct->ondisk_path, &sb) != 0) {
2292 			err = got_error_prefix_errno2("lstat", ct->ondisk_path);
2293 			goto done;
2294 		}
2295 		ct->mode = sb.st_mode;
2296 	}
2297 
2298 	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
2299 	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
2300 	    relpath) == -1) {
2301 		err = got_error_prefix_errno("asprintf");
2302 		goto done;
2303 	}
2304 
2305 	ct->status = status;
2306 	ct->blob_id = NULL; /* will be filled in when blob gets created */
2307 	if (ct->status != GOT_STATUS_ADD) {
2308 		ct->base_id = got_object_id_dup(id);
2309 		if (ct->base_id == NULL) {
2310 			err = got_error_prefix_errno("got_object_id_dup");
2311 			goto done;
2312 		}
2313 	}
2314 	ct->path = strdup(path);
2315 	if (ct->path == NULL) {
2316 		err = got_error_prefix_errno("strdup");
2317 		goto done;
2318 	}
2319 	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
2320 done:
2321 	if (ct && (err || new == NULL))
2322 		free_commitable(ct);
2323 	free(parent_path);
2324 	free(path);
2325 	return err;
2326 }
2327 
2328 static const struct got_error *write_tree(struct got_object_id **,
2329     struct got_tree_object *, const char *, struct got_pathlist_head *,
2330     got_worktree_status_cb status_cb, void *status_arg,
2331     struct got_repository *);
2332 
2333 static const struct got_error *
2334 write_subtree(struct got_object_id **new_subtree_id,
2335     struct got_tree_entry *te, const char *parent_path,
2336     struct got_pathlist_head *commitable_paths,
2337     got_worktree_status_cb status_cb, void *status_arg,
2338     struct got_repository *repo)
2339 {
2340 	const struct got_error *err = NULL;
2341 	struct got_tree_object *subtree;
2342 	char *subpath;
2343 
2344 	if (asprintf(&subpath, "%s%s%s", parent_path,
2345 	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
2346 		return got_error_prefix_errno("asprintf");
2347 
2348 	err = got_object_open_as_tree(&subtree, repo, te->id);
2349 	if (err)
2350 		return err;
2351 
2352 	err = write_tree(new_subtree_id, subtree, subpath, commitable_paths,
2353 	    status_cb, status_arg, repo);
2354 	got_object_tree_close(subtree);
2355 	free(subpath);
2356 	return err;
2357 }
2358 
2359 static const struct got_error *
2360 match_ct_parent_path(int *match, struct commitable *ct, const char *path)
2361 {
2362 	const struct got_error *err = NULL;
2363 	char *ct_parent_path = NULL;
2364 
2365 	*match = 0;
2366 
2367 	if (strchr(ct->path, '/') == NULL) {
2368 		*match = got_path_is_root_dir(path);
2369 		return NULL;
2370 	}
2371 
2372 	err = got_path_dirname(&ct_parent_path, ct->path);
2373 	if (err)
2374 		return err;
2375 	*match = (strcmp(path, ct_parent_path) == 0);
2376 	free(ct_parent_path);
2377 	return err;
2378 }
2379 
2380 static mode_t
2381 get_ct_file_mode(struct commitable *ct)
2382 {
2383 	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
2384 }
2385 
2386 static const struct got_error *
2387 alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
2388     struct got_tree_entry *te, struct commitable *ct)
2389 {
2390 	const struct got_error *err = NULL;
2391 
2392 	*new_te = NULL;
2393 
2394 	err = got_object_tree_entry_dup(new_te, te);
2395 	if (err)
2396 		goto done;
2397 
2398 	(*new_te)->mode = get_ct_file_mode(ct);
2399 
2400 	free((*new_te)->id);
2401 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2402 	if ((*new_te)->id == NULL) {
2403 		err = got_error_prefix_errno("got_object_id_dup");
2404 		goto done;
2405 	}
2406 done:
2407 	if (err && *new_te) {
2408 		got_object_tree_entry_close(*new_te);
2409 		*new_te = NULL;
2410 	}
2411 	return err;
2412 }
2413 
2414 static const struct got_error *
2415 alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
2416     struct commitable *ct)
2417 {
2418 	const struct got_error *err = NULL;
2419 	char *ct_name;
2420 
2421 	 *new_te = NULL;
2422 
2423 	*new_te = calloc(1, sizeof(**new_te));
2424 	if (*new_te == NULL)
2425 		return got_error_prefix_errno("calloc");
2426 
2427 	ct_name = basename(ct->path);
2428 	if (ct_name == NULL) {
2429 		err = got_error_prefix_errno2("basename", ct->path);
2430 		goto done;
2431 	}
2432 	(*new_te)->name = strdup(ct_name);
2433 	if ((*new_te)->name == NULL) {
2434 		err = got_error_prefix_errno("strdup");
2435 		goto done;
2436 	}
2437 
2438 	(*new_te)->mode = get_ct_file_mode(ct);
2439 
2440 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2441 	if ((*new_te)->id == NULL) {
2442 		err = got_error_prefix_errno("got_object_id_dup");
2443 		goto done;
2444 	}
2445 done:
2446 	if (err && *new_te) {
2447 		got_object_tree_entry_close(*new_te);
2448 		*new_te = NULL;
2449 	}
2450 	return err;
2451 }
2452 
2453 static const struct got_error *
2454 insert_tree_entry(struct got_tree_entry *new_te,
2455     struct got_pathlist_head *paths)
2456 {
2457 	const struct got_error *err = NULL;
2458 	struct got_pathlist_entry *new_pe;
2459 
2460 	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
2461 	if (err)
2462 		return err;
2463 	if (new_pe == NULL)
2464 		return got_error(GOT_ERR_TREE_DUP_ENTRY);
2465 	return NULL;
2466 }
2467 
2468 static const struct got_error *
2469 report_ct_status(struct commitable *ct,
2470     got_worktree_status_cb status_cb, void *status_arg)
2471 {
2472 	const char *ct_path = ct->path;
2473 	while (ct_path[0] == '/')
2474 		ct_path++;
2475 	return (*status_cb)(status_arg, ct->status, ct_path, ct->blob_id);
2476 }
2477 
2478 static const struct got_error *
2479 match_modified_subtree(int *modified, struct got_tree_entry *te,
2480     const char *base_tree_path, struct got_pathlist_head *commitable_paths)
2481 {
2482 	const struct got_error *err = NULL;
2483 	struct got_pathlist_entry *pe;
2484 	char *te_path;
2485 
2486 	*modified = 0;
2487 
2488 	if (asprintf(&te_path, "%s%s%s", base_tree_path,
2489 	    got_path_is_root_dir(base_tree_path) ? "" : "/",
2490 	    te->name) == -1)
2491 		return got_error_prefix_errno("asprintf");
2492 
2493 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2494 		struct commitable *ct = pe->data;
2495 		*modified = got_path_is_child(ct->in_repo_path, te_path,
2496 		    strlen(te_path));
2497 		 if (*modified)
2498 			break;
2499 	}
2500 
2501 	free(te_path);
2502 	return err;
2503 }
2504 
2505 static const struct got_error *
2506 match_deleted_or_modified_ct(struct commitable **ctp,
2507     struct got_tree_entry *te, const char *base_tree_path,
2508     struct got_pathlist_head *commitable_paths)
2509 {
2510 	const struct got_error *err = NULL;
2511 	struct got_pathlist_entry *pe;
2512 
2513 	*ctp = NULL;
2514 
2515 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2516 		struct commitable *ct = pe->data;
2517 		char *ct_name = NULL;
2518 		int path_matches;
2519 
2520 		if (ct->status != GOT_STATUS_MODIFY &&
2521 		    ct->status != GOT_STATUS_DELETE)
2522 			continue;
2523 
2524 		if (got_object_id_cmp(ct->base_id, te->id) != 0)
2525 			continue;
2526 
2527 		 err = match_ct_parent_path(&path_matches, ct, base_tree_path);
2528 		 if (err)
2529 			return err;
2530 		if (!path_matches)
2531 			continue;
2532 
2533 		ct_name = basename(pe->path);
2534 		if (ct_name == NULL)
2535 			return got_error_prefix_errno2("basename", pe->path);
2536 
2537 		if (strcmp(te->name, ct_name) != 0)
2538 			continue;
2539 
2540 		*ctp = ct;
2541 		break;
2542 	}
2543 
2544 	return err;
2545 }
2546 
2547 static const struct got_error *
2548 write_tree(struct got_object_id **new_tree_id,
2549     struct got_tree_object *base_tree, const char *path_base_tree,
2550     struct got_pathlist_head *commitable_paths,
2551     got_worktree_status_cb status_cb, void *status_arg,
2552     struct got_repository *repo)
2553 {
2554 	const struct got_error *err = NULL;
2555 	const struct got_tree_entries *base_entries = NULL;
2556 	struct got_pathlist_head paths;
2557 	struct got_tree_entries new_tree_entries;
2558 	struct got_tree_entry *te, *new_te = NULL;
2559 	struct got_pathlist_entry *pe;
2560 
2561 	TAILQ_INIT(&paths);
2562 	new_tree_entries.nentries = 0;
2563 	SIMPLEQ_INIT(&new_tree_entries.head);
2564 
2565 	/* Insert, and recurse into, newly added entries first. */
2566 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2567 		struct commitable *ct = pe->data;
2568 		char *child_path = NULL, *slash;
2569 
2570 		if (ct->status != GOT_STATUS_ADD)
2571 			continue;
2572 
2573 		 if (!got_path_is_child(pe->path, path_base_tree,
2574 		     strlen(path_base_tree)))
2575 			continue;
2576 
2577 		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
2578 		    pe->path);
2579 		if (err)
2580 			goto done;
2581 
2582 		slash = strchr(child_path, '/');
2583 		if (slash == NULL) {
2584 			err = alloc_added_blob_tree_entry(&new_te, ct);
2585 			if (err)
2586 				goto done;
2587 			err = report_ct_status(ct, status_cb, status_arg);
2588 			if (err)
2589 				goto done;
2590 		} else {
2591 			char *subtree_path;
2592 			struct got_pathlist_entry *pe2;
2593 			int visited = 0;
2594 
2595 			*slash = '\0'; /* trim trailing path components */
2596 			if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
2597 			    got_path_is_root_dir(path_base_tree) ? "" : "/",
2598 			    child_path) == -1) {
2599 				err = got_error_prefix_errno("asprintf");
2600 				goto done;
2601 			}
2602 			TAILQ_FOREACH(pe2, &paths, entry) {
2603 				if (got_path_cmp(subtree_path, pe2->path) != 0)
2604 					continue;
2605 				visited = 1;
2606 				break;
2607 			}
2608 			if (visited) {
2609 				free(subtree_path);
2610 				continue;
2611 			}
2612 
2613 			new_te = calloc(1, sizeof(*new_te));
2614 			new_te->mode = S_IFDIR;
2615 			new_te->name = strdup(child_path);
2616 			if (new_te->name == NULL) {
2617 				err = got_error_prefix_errno("strdup");
2618 				got_object_tree_entry_close(new_te);
2619 				new_te = NULL;
2620 				goto done;
2621 			}
2622 			err = write_tree(&new_te->id, NULL, subtree_path,
2623 			    commitable_paths, status_cb, status_arg, repo);
2624 			free(subtree_path);
2625 			if (err) {
2626 				got_object_tree_entry_close(new_te);
2627 				new_te = NULL;
2628 				goto done;
2629 			}
2630 		}
2631 		err = insert_tree_entry(new_te, &paths);
2632 		if (err)
2633 			goto done;
2634 	}
2635 
2636 	if (base_tree) {
2637 		/* Handle modified and deleted entries. */
2638 		base_entries = got_object_tree_get_entries(base_tree);
2639 		SIMPLEQ_FOREACH(te, &base_entries->head, entry) {
2640 			struct commitable *ct = NULL;
2641 
2642 			if (S_ISDIR(te->mode)) {
2643 				int modified;
2644 				err = got_object_tree_entry_dup(&new_te, te);
2645 				if (err)
2646 					goto done;
2647 				err = match_modified_subtree(&modified, te,
2648 				    path_base_tree, commitable_paths);
2649 				if (err)
2650 					goto done;
2651 				/* Avoid recursion into unmodified subtrees. */
2652 				if (modified) {
2653 					free(new_te->id);
2654 					err = write_subtree(&new_te->id, te,
2655 					    path_base_tree, commitable_paths,
2656 					    status_cb, status_arg, repo);
2657 					if (err)
2658 						goto done;
2659 				}
2660 				err = insert_tree_entry(new_te, &paths);
2661 				if (err)
2662 					goto done;
2663 				continue;
2664 			}
2665 
2666 			err = match_deleted_or_modified_ct(&ct, te,
2667 			    path_base_tree, commitable_paths);
2668 			if (ct) {
2669 				/* NB: Deleted entries get dropped here. */
2670 				if (ct->status == GOT_STATUS_MODIFY) {
2671 					err = alloc_modified_blob_tree_entry(
2672 					    &new_te, te, ct);
2673 					if (err)
2674 						goto done;
2675 					err = insert_tree_entry(new_te, &paths);
2676 					if (err)
2677 						goto done;
2678 				}
2679 				err = report_ct_status(ct, status_cb, status_arg);
2680 				if (err)
2681 					goto done;
2682 			} else {
2683 				/* Entry is unchanged; just copy it. */
2684 				err = got_object_tree_entry_dup(&new_te, te);
2685 				if (err)
2686 					goto done;
2687 				err = insert_tree_entry(new_te, &paths);
2688 				if (err)
2689 					goto done;
2690 			}
2691 		}
2692 	}
2693 
2694 	/* Write new list of entries; deleted entries have been dropped. */
2695 	TAILQ_FOREACH(pe, &paths, entry) {
2696 		struct got_tree_entry *te = pe->data;
2697 		new_tree_entries.nentries++;
2698 		SIMPLEQ_INSERT_TAIL(&new_tree_entries.head, te, entry);
2699 	}
2700 	err = got_object_tree_create(new_tree_id, &new_tree_entries, repo);
2701 done:
2702 	got_object_tree_entries_close(&new_tree_entries);
2703 	got_pathlist_free(&paths);
2704 	return err;
2705 }
2706 
2707 static const struct got_error *
2708 update_fileindex_after_commit(struct got_pathlist_head *commitable_paths,
2709     struct got_object_id *new_base_commit_id, struct got_worktree *worktree)
2710 {
2711 	const struct got_error *err = NULL;
2712 	char *fileindex_path = NULL, *new_fileindex_path = NULL;
2713 	struct got_fileindex *fileindex = NULL;
2714 	FILE *new_index = NULL;
2715 	struct got_pathlist_entry *pe;
2716 
2717 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2718 	if (err)
2719 		return err;
2720 
2721 	err = got_opentemp_named(&new_fileindex_path, &new_index,
2722 	    fileindex_path);
2723 	if (err)
2724 		goto done;
2725 
2726 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2727 		struct got_fileindex_entry *ie;
2728 		struct commitable *ct = pe->data;
2729 
2730 		ie = got_fileindex_entry_get(fileindex, pe->path);
2731 		if (ie) {
2732 			if (ct->status == GOT_STATUS_DELETE) {
2733 				got_fileindex_entry_remove(fileindex, ie);
2734 				got_fileindex_entry_free(ie);
2735 			} else
2736 				err = got_fileindex_entry_update(ie,
2737 				    ct->ondisk_path, ct->blob_id->sha1,
2738 				    new_base_commit_id->sha1, 1);
2739 		} else {
2740 			err = got_fileindex_entry_alloc(&ie,
2741 			    ct->ondisk_path, pe->path, ct->blob_id->sha1,
2742 			    new_base_commit_id->sha1);
2743 			if (err)
2744 				goto done;
2745 			err = got_fileindex_entry_add(fileindex, ie);
2746 			if (err)
2747 				goto done;
2748 		}
2749 	}
2750 
2751 	err = got_fileindex_write(fileindex, new_index);
2752 	if (err)
2753 		goto done;
2754 
2755 	if (rename(new_fileindex_path, fileindex_path) != 0) {
2756 		err = got_error_prefix_errno3("rename", new_fileindex_path,
2757 		    fileindex_path);
2758 		unlink(new_fileindex_path);
2759 		goto done;
2760 	}
2761 
2762 	free(new_fileindex_path);
2763 	new_fileindex_path = NULL;
2764 
2765 done:
2766 	if (new_fileindex_path)
2767 		unlink(new_fileindex_path);
2768 	if (new_index)
2769 		fclose(new_index);
2770 	free(new_fileindex_path);
2771 	free(fileindex_path);
2772 	got_fileindex_free(fileindex);
2773 	return err;
2774 }
2775 
2776 static const struct got_error *
2777 check_ct_out_of_date(struct commitable *ct, struct got_repository *repo,
2778 	struct got_object_id *head_commit_id)
2779 {
2780 	const struct got_error *err = NULL;
2781 	struct got_object_id *id_in_head;
2782 
2783 	/*
2784 	 * XXX This should probably be checking each commit from
2785 	 * worktree's base_commit -> head and verify that the
2786 	 * same blob exists in each of these commits.
2787 	 * Removals+additions within this line of history could mean
2788 	 * that renames have occured in which case we should really
2789 	 * be forcing the user to run an update...
2790 	 */
2791 	err = got_object_id_by_path(&id_in_head, repo,
2792 	    head_commit_id, ct->in_repo_path);
2793 	if (err) {
2794 		if (err->code != GOT_ERR_NO_TREE_ENTRY)
2795 			return err;
2796 		if (ct->status != GOT_STATUS_ADD)
2797 			return got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
2798 		err = NULL;
2799 		id_in_head = NULL;
2800 	}
2801 
2802 	if (id_in_head && got_object_id_cmp(id_in_head, ct->base_id) != 0)
2803 		err = got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
2804 
2805 	free(id_in_head);
2806 	return err;
2807 }
2808 
2809 const struct got_error *
2810 got_worktree_commit(struct got_object_id **new_commit_id,
2811     struct got_worktree *worktree, const char *ondisk_path,
2812     const char *author, const char *committer, const char *logmsg,
2813     got_worktree_status_cb status_cb, void *status_arg,
2814     struct got_repository *repo)
2815 {
2816 	const struct got_error *err = NULL, *unlockerr = NULL;
2817 	struct collect_commitables_arg cc_arg;
2818 	struct got_pathlist_head commitable_paths;
2819 	struct got_pathlist_entry *pe;
2820 	char *relpath = NULL;
2821 	const char *head_ref_name = NULL;
2822 	struct got_reference *head_ref = NULL;
2823 	struct got_commit_object *head_commit = NULL;
2824 	struct got_object_id *head_commit_id = NULL;
2825 	struct got_reference *head_ref2 = NULL;
2826 	struct got_object_id *head_commit_id2 = NULL;
2827 	struct got_tree_object *head_tree = NULL;
2828 	struct got_object_id *new_tree_id = NULL;
2829 	struct got_object_id_queue parent_ids;
2830 	struct got_object_qid *pid = NULL;
2831 
2832 	*new_commit_id = NULL;
2833 
2834 	TAILQ_INIT(&commitable_paths);
2835 	SIMPLEQ_INIT(&parent_ids);
2836 
2837 	if (ondisk_path) {
2838 		err = got_path_skip_common_ancestor(&relpath,
2839 		    worktree->root_path, ondisk_path);
2840 		if (err)
2841 			return err;
2842 	}
2843 
2844 	err = lock_worktree(worktree, LOCK_EX);
2845 	if (err)
2846 		goto done;
2847 
2848 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name);
2849 	if (err)
2850 		goto done;
2851 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
2852 	if (err)
2853 		goto done;
2854 
2855 	cc_arg.commitable_paths = &commitable_paths;
2856 	cc_arg.worktree = worktree;
2857 	cc_arg.repo = repo;
2858 	err = got_worktree_status(worktree, relpath ? relpath : "",
2859 	    repo, collect_commitables, &cc_arg, NULL, NULL);
2860 	if (err)
2861 		goto done;
2862 
2863 	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
2864 	if (err)
2865 		goto done;
2866 
2867 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
2868 		struct commitable *ct = pe->data;
2869 		err = check_ct_out_of_date(ct, repo, head_commit_id);
2870 		if (err)
2871 			goto done;
2872 	}
2873 
2874 	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
2875 	if (err)
2876 		goto done;
2877 
2878 	/* TODO: collect commit message if not specified */
2879 
2880 	/* Create blobs from added and modified files and record their IDs. */
2881 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
2882 		struct commitable *ct = pe->data;
2883 		char *ondisk_path;
2884 
2885 		if (ct->status != GOT_STATUS_ADD &&
2886 		    ct->status != GOT_STATUS_MODIFY)
2887 			continue;
2888 
2889 		if (asprintf(&ondisk_path, "%s/%s",
2890 		    worktree->root_path, pe->path) == -1) {
2891 			err = got_error_prefix_errno("asprintf");
2892 			goto done;
2893 		}
2894 		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
2895 		free(ondisk_path);
2896 		if (err)
2897 			goto done;
2898 	}
2899 
2900 	/* Recursively write new tree objects. */
2901 	err = write_tree(&new_tree_id, head_tree, "/", &commitable_paths,
2902 	    status_cb, status_arg, repo);
2903 	if (err)
2904 		goto done;
2905 
2906 	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
2907 	if (err)
2908 		goto done;
2909 	SIMPLEQ_INSERT_TAIL(&parent_ids, pid, entry);
2910 	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
2911 	    1, author, time(NULL), committer, time(NULL), logmsg, repo);
2912 	got_object_qid_free(pid);
2913 	if (err)
2914 		goto done;
2915 
2916 	/* Check if a concurrent commit to our branch has occurred. */
2917 	/* XXX ideally we'd lock the reference file here to avoid a race */
2918 	head_ref_name = got_worktree_get_head_ref_name(worktree);
2919 	if (head_ref_name == NULL) {
2920 		err = got_error_prefix_errno("got_worktree_get_head_ref_name");
2921 		goto done;
2922 	}
2923 	err = got_ref_open(&head_ref2, repo, head_ref_name);
2924 	if (err)
2925 		goto done;
2926 	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
2927 	if (err)
2928 		goto done;
2929 	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
2930 		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
2931 		goto done;
2932 	}
2933 	/* Update branch head in repository. */
2934 	err = got_ref_change_ref(head_ref, *new_commit_id);
2935 	if (err)
2936 		goto done;
2937 	err = got_ref_write(head_ref, repo);
2938 	if (err)
2939 		goto done;
2940 	/* XXX race has ended here */
2941 
2942 	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
2943 	if (err)
2944 		goto done;
2945 
2946 	err = ref_base_commit(worktree, repo);
2947 	if (err)
2948 		goto done;
2949 
2950 	err = update_fileindex_after_commit(&commitable_paths,
2951 	    *new_commit_id, worktree);
2952 	if (err)
2953 		goto done;
2954 done:
2955 	unlockerr = lock_worktree(worktree, LOCK_SH);
2956 	if (unlockerr && err == NULL)
2957 		err = unlockerr;
2958 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
2959 		struct commitable *ct = pe->data;
2960 		free_commitable(ct);
2961 	}
2962 	got_pathlist_free(&commitable_paths);
2963 	if (head_tree)
2964 		got_object_tree_close(head_tree);
2965 	if (head_commit)
2966 		got_object_commit_close(head_commit);
2967 	free(relpath);
2968 	free(head_commit_id);
2969 	free(head_commit_id2);
2970 	if (head_ref)
2971 		got_ref_close(head_ref);
2972 	if (head_ref2)
2973 		got_ref_close(head_ref2);
2974 	return err;
2975 }