1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/stat.h>
18 #include <sys/limits.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 
22 #include <dirent.h>
23 #include <stddef.h>
24 #include <string.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <fcntl.h>
28 #include <errno.h>
29 #include <unistd.h>
30 #include <sha1.h>
31 #include <zlib.h>
32 #include <fnmatch.h>
33 #include <libgen.h>
34 #include <uuid.h>
35 #include <util.h>
36 
37 #include "got_error.h"
38 #include "got_repository.h"
39 #include "got_reference.h"
40 #include "got_object.h"
41 #include "got_path.h"
42 #include "got_worktree.h"
43 #include "got_opentemp.h"
44 #include "got_diff.h"
45 
46 #include "got_lib_worktree.h"
47 #include "got_lib_sha1.h"
48 #include "got_lib_fileindex.h"
49 #include "got_lib_inflate.h"
50 #include "got_lib_delta.h"
51 #include "got_lib_object.h"
52 #include "got_lib_object_parse.h"
53 #include "got_lib_object_create.h"
54 #include "got_lib_object_idset.h"
55 #include "got_lib_diff.h"
56 
57 #ifndef MIN
58 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
59 #endif
60 
61 static const struct got_error *
62 create_meta_file(const char *path_got, const char *name, const char *content)
63 {
64 	const struct got_error *err = NULL;
65 	char *path;
66 	int fd = -1;
67 
68 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
69 		err = got_error_from_errno("asprintf");
70 		path = NULL;
71 		goto done;
72 	}
73 
74 	fd = open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
75 	    GOT_DEFAULT_FILE_MODE);
76 	if (fd == -1) {
77 		err = got_error_from_errno2("open", path);
78 		goto done;
79 	}
80 
81 	if (content) {
82 		int len = dprintf(fd, "%s\n", content);
83 		if (len != strlen(content) + 1) {
84 			err = got_error_from_errno("dprintf");
85 			goto done;
86 		}
87 	}
88 
89 done:
90 	if (fd != -1 && close(fd) == -1 && err == NULL)
91 		err = got_error_from_errno("close");
92 	free(path);
93 	return err;
94 }
95 
96 static const struct got_error *
97 update_meta_file(const char *path_got, const char *name, const char *content)
98 {
99 	const struct got_error *err = NULL;
100 	FILE *tmpfile = NULL;
101 	char *tmppath = NULL;
102 	char *path = NULL;
103 
104 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
105 		err = got_error_from_errno("asprintf");
106 		path = NULL;
107 		goto done;
108 	}
109 
110 	err = got_opentemp_named(&tmppath, &tmpfile, path);
111 	if (err)
112 		goto done;
113 
114 	if (content) {
115 		int len = fprintf(tmpfile, "%s\n", content);
116 		if (len != strlen(content) + 1) {
117 			err = got_error_from_errno2("fprintf", tmppath);
118 			goto done;
119 		}
120 	}
121 
122 	if (rename(tmppath, path) != 0) {
123 		err = got_error_from_errno3("rename", tmppath, path);
124 		unlink(tmppath);
125 		goto done;
126 	}
127 
128 done:
129 	if (fclose(tmpfile) != 0 && err == NULL)
130 		err = got_error_from_errno2("fclose", tmppath);
131 	free(tmppath);
132 	return err;
133 }
134 
135 static const struct got_error *
136 read_meta_file(char **content, const char *path_got, const char *name)
137 {
138 	const struct got_error *err = NULL;
139 	char *path;
140 	int fd = -1;
141 	ssize_t n;
142 	struct stat sb;
143 
144 	*content = NULL;
145 
146 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
147 		err = got_error_from_errno("asprintf");
148 		path = NULL;
149 		goto done;
150 	}
151 
152 	fd = open(path, O_RDONLY | O_NOFOLLOW);
153 	if (fd == -1) {
154 		if (errno == ENOENT)
155 			err = got_error(GOT_ERR_WORKTREE_META);
156 		else
157 			err = got_error_from_errno2("open", path);
158 		goto done;
159 	}
160 	if (flock(fd, LOCK_SH | LOCK_NB) == -1) {
161 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
162 		    : got_error_from_errno2("flock", path));
163 		goto done;
164 	}
165 
166 	if (lstat(path, &sb) != 0) {
167 		err = got_error_from_errno2("lstat", path);
168 		goto done;
169 	}
170 	*content = calloc(1, sb.st_size);
171 	if (*content == NULL) {
172 		err = got_error_from_errno("calloc");
173 		goto done;
174 	}
175 
176 	n = read(fd, *content, sb.st_size);
177 	if (n != sb.st_size) {
178 		err = (n == -1 ? got_error_from_errno2("read", path) :
179 		    got_error(GOT_ERR_WORKTREE_META));
180 		goto done;
181 	}
182 	if ((*content)[sb.st_size - 1] != '\n') {
183 		err = got_error(GOT_ERR_WORKTREE_META);
184 		goto done;
185 	}
186 	(*content)[sb.st_size - 1] = '\0';
187 
188 done:
189 	if (fd != -1 && close(fd) == -1 && err == NULL)
190 		err = got_error_from_errno2("close", path_got);
191 	free(path);
192 	if (err) {
193 		free(*content);
194 		*content = NULL;
195 	}
196 	return err;
197 }
198 
199 static const struct got_error *
200 write_head_ref(const char *path_got, struct got_reference *head_ref)
201 {
202 	const struct got_error *err = NULL;
203 	char *refstr = NULL;
204 
205 	if (got_ref_is_symbolic(head_ref)) {
206 		refstr = got_ref_to_str(head_ref);
207 		if (refstr == NULL)
208 			return got_error_from_errno("got_ref_to_str");
209 	} else {
210 		refstr = strdup(got_ref_get_name(head_ref));
211 		if (refstr == NULL)
212 			return got_error_from_errno("strdup");
213 	}
214 	err = update_meta_file(path_got, GOT_WORKTREE_HEAD_REF, refstr);
215 	free(refstr);
216 	return err;
217 }
218 
219 const struct got_error *
220 got_worktree_init(const char *path, struct got_reference *head_ref,
221     const char *prefix, struct got_repository *repo)
222 {
223 	const struct got_error *err = NULL;
224 	struct got_object_id *commit_id = NULL;
225 	uuid_t uuid;
226 	uint32_t uuid_status;
227 	int obj_type;
228 	char *path_got = NULL;
229 	char *formatstr = NULL;
230 	char *absprefix = NULL;
231 	char *basestr = NULL;
232 	char *uuidstr = NULL;
233 
234 	if (strcmp(path, got_repo_get_path(repo)) == 0) {
235 		err = got_error(GOT_ERR_WORKTREE_REPO);
236 		goto done;
237 	}
238 
239 	err = got_ref_resolve(&commit_id, repo, head_ref);
240 	if (err)
241 		return err;
242 	err = got_object_get_type(&obj_type, repo, commit_id);
243 	if (err)
244 		return err;
245 	if (obj_type != GOT_OBJ_TYPE_COMMIT)
246 		return got_error(GOT_ERR_OBJ_TYPE);
247 
248 	if (!got_path_is_absolute(prefix)) {
249 		if (asprintf(&absprefix, "/%s", prefix) == -1)
250 			return got_error_from_errno("asprintf");
251 	}
252 
253 	/* Create top-level directory (may already exist). */
254 	if (mkdir(path, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
255 		err = got_error_from_errno2("mkdir", path);
256 		goto done;
257 	}
258 
259 	/* Create .got directory (may already exist). */
260 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
261 		err = got_error_from_errno("asprintf");
262 		goto done;
263 	}
264 	if (mkdir(path_got, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
265 		err = got_error_from_errno2("mkdir", path_got);
266 		goto done;
267 	}
268 
269 	/* Create an empty lock file. */
270 	err = create_meta_file(path_got, GOT_WORKTREE_LOCK, NULL);
271 	if (err)
272 		goto done;
273 
274 	/* Create an empty file index. */
275 	err = create_meta_file(path_got, GOT_WORKTREE_FILE_INDEX, NULL);
276 	if (err)
277 		goto done;
278 
279 	/* Write the HEAD reference. */
280 	err = write_head_ref(path_got, head_ref);
281 	if (err)
282 		goto done;
283 
284 	/* Record our base commit. */
285 	err = got_object_id_str(&basestr, commit_id);
286 	if (err)
287 		goto done;
288 	err = create_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, basestr);
289 	if (err)
290 		goto done;
291 
292 	/* Store path to repository. */
293 	err = create_meta_file(path_got, GOT_WORKTREE_REPOSITORY,
294 	    got_repo_get_path(repo));
295 	if (err)
296 		goto done;
297 
298 	/* Store in-repository path prefix. */
299 	err = create_meta_file(path_got, GOT_WORKTREE_PATH_PREFIX,
300 	    absprefix ? absprefix : prefix);
301 	if (err)
302 		goto done;
303 
304 	/* Generate UUID. */
305 	uuid_create(&uuid, &uuid_status);
306 	if (uuid_status != uuid_s_ok) {
307 		err = got_error_uuid(uuid_status);
308 		goto done;
309 	}
310 	uuid_to_string(&uuid, &uuidstr, &uuid_status);
311 	if (uuid_status != uuid_s_ok) {
312 		err = got_error_uuid(uuid_status);
313 		goto done;
314 	}
315 	err = create_meta_file(path_got, GOT_WORKTREE_UUID, uuidstr);
316 	if (err)
317 		goto done;
318 
319 	/* Stamp work tree with format file. */
320 	if (asprintf(&formatstr, "%d", GOT_WORKTREE_FORMAT_VERSION) == -1) {
321 		err = got_error_from_errno("asprintf");
322 		goto done;
323 	}
324 	err = create_meta_file(path_got, GOT_WORKTREE_FORMAT, formatstr);
325 	if (err)
326 		goto done;
327 
328 done:
329 	free(commit_id);
330 	free(path_got);
331 	free(formatstr);
332 	free(absprefix);
333 	free(basestr);
334 	free(uuidstr);
335 	return err;
336 }
337 
338 static const struct got_error *
339 open_worktree(struct got_worktree **worktree, const char *path)
340 {
341 	const struct got_error *err = NULL;
342 	char *path_got;
343 	char *formatstr = NULL;
344 	char *uuidstr = NULL;
345 	char *path_lock = NULL;
346 	char *base_commit_id_str = NULL;
347 	int version, fd = -1;
348 	const char *errstr;
349 	struct got_repository *repo = NULL;
350 	uint32_t uuid_status;
351 
352 	*worktree = NULL;
353 
354 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
355 		err = got_error_from_errno("asprintf");
356 		path_got = NULL;
357 		goto done;
358 	}
359 
360 	if (asprintf(&path_lock, "%s/%s", path_got, GOT_WORKTREE_LOCK) == -1) {
361 		err = got_error_from_errno("asprintf");
362 		path_lock = NULL;
363 		goto done;
364 	}
365 
366 	fd = open(path_lock, O_RDWR | O_EXLOCK | O_NONBLOCK);
367 	if (fd == -1) {
368 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
369 		    : got_error_from_errno2("open", path_lock));
370 		goto done;
371 	}
372 
373 	err = read_meta_file(&formatstr, path_got, GOT_WORKTREE_FORMAT);
374 	if (err)
375 		goto done;
376 
377 	version = strtonum(formatstr, 1, INT_MAX, &errstr);
378 	if (errstr) {
379 		err = got_error(GOT_ERR_WORKTREE_META);
380 		goto done;
381 	}
382 	if (version != GOT_WORKTREE_FORMAT_VERSION) {
383 		err = got_error(GOT_ERR_WORKTREE_VERS);
384 		goto done;
385 	}
386 
387 	*worktree = calloc(1, sizeof(**worktree));
388 	if (*worktree == NULL) {
389 		err = got_error_from_errno("calloc");
390 		goto done;
391 	}
392 	(*worktree)->lockfd = -1;
393 
394 	(*worktree)->root_path = strdup(path);
395 	if ((*worktree)->root_path == NULL) {
396 		err = got_error_from_errno("strdup");
397 		goto done;
398 	}
399 	err = read_meta_file(&(*worktree)->repo_path, path_got,
400 	    GOT_WORKTREE_REPOSITORY);
401 	if (err)
402 		goto done;
403 
404 	err = read_meta_file(&(*worktree)->path_prefix, path_got,
405 	    GOT_WORKTREE_PATH_PREFIX);
406 	if (err)
407 		goto done;
408 
409 	err = read_meta_file(&base_commit_id_str, path_got,
410 	    GOT_WORKTREE_BASE_COMMIT);
411 	if (err)
412 		goto done;
413 
414 	err = read_meta_file(&uuidstr, path_got, GOT_WORKTREE_UUID);
415 	if (err)
416 		goto done;
417 	uuid_from_string(uuidstr, &(*worktree)->uuid, &uuid_status);
418 	if (uuid_status != uuid_s_ok) {
419 		err = got_error_uuid(uuid_status);
420 		goto done;
421 	}
422 
423 	err = got_repo_open(&repo, (*worktree)->repo_path);
424 	if (err)
425 		goto done;
426 
427 	err = got_object_resolve_id_str(&(*worktree)->base_commit_id, repo,
428 	    base_commit_id_str);
429 	if (err)
430 		goto done;
431 
432 	err = read_meta_file(&(*worktree)->head_ref_name, path_got,
433 	    GOT_WORKTREE_HEAD_REF);
434 done:
435 	if (repo)
436 		got_repo_close(repo);
437 	free(path_got);
438 	free(path_lock);
439 	free(base_commit_id_str);
440 	free(uuidstr);
441 	free(formatstr);
442 	if (err) {
443 		if (fd != -1)
444 			close(fd);
445 		if (*worktree != NULL)
446 			got_worktree_close(*worktree);
447 		*worktree = NULL;
448 	} else
449 		(*worktree)->lockfd = fd;
450 
451 	return err;
452 }
453 
454 const struct got_error *
455 got_worktree_open(struct got_worktree **worktree, const char *path)
456 {
457 	const struct got_error *err = NULL;
458 
459 	do {
460 		err = open_worktree(worktree, path);
461 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT))
462 			return err;
463 		if (*worktree)
464 			return NULL;
465 		path = dirname(path);
466 		if (path == NULL)
467 			return got_error_from_errno2("dirname", path);
468 	} while (!((path[0] == '.' || path[0] == '/') && path[1] == '\0'));
469 
470 	return got_error(GOT_ERR_NOT_WORKTREE);
471 }
472 
473 const struct got_error *
474 got_worktree_close(struct got_worktree *worktree)
475 {
476 	const struct got_error *err = NULL;
477 	free(worktree->root_path);
478 	free(worktree->repo_path);
479 	free(worktree->path_prefix);
480 	free(worktree->base_commit_id);
481 	free(worktree->head_ref_name);
482 	if (worktree->lockfd != -1)
483 		if (close(worktree->lockfd) != 0)
484 			err = got_error_from_errno2("close",
485 			    got_worktree_get_root_path(worktree));
486 	free(worktree);
487 	return err;
488 }
489 
490 const char *
491 got_worktree_get_root_path(struct got_worktree *worktree)
492 {
493 	return worktree->root_path;
494 }
495 
496 const char *
497 got_worktree_get_repo_path(struct got_worktree *worktree)
498 {
499 	return worktree->repo_path;
500 }
501 
502 const char *
503 got_worktree_get_path_prefix(struct got_worktree *worktree)
504 {
505 	return worktree->path_prefix;
506 }
507 
508 const struct got_error *
509 got_worktree_match_path_prefix(int *match, struct got_worktree *worktree,
510     const char *path_prefix)
511 {
512 	char *absprefix = NULL;
513 
514 	if (!got_path_is_absolute(path_prefix)) {
515 		if (asprintf(&absprefix, "/%s", path_prefix) == -1)
516 			return got_error_from_errno("asprintf");
517 	}
518 	*match = (strcmp(absprefix ? absprefix : path_prefix,
519 	    worktree->path_prefix) == 0);
520 	free(absprefix);
521 	return NULL;
522 }
523 
524 const char *
525 got_worktree_get_head_ref_name(struct got_worktree *worktree)
526 {
527 	return worktree->head_ref_name;
528 }
529 
530 const struct got_error *
531 got_worktree_set_head_ref(struct got_worktree *worktree,
532     struct got_reference *head_ref)
533 {
534 	const struct got_error *err = NULL;
535 	char *path_got = NULL, *head_ref_name = NULL;
536 
537 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
538 	    GOT_WORKTREE_GOT_DIR) == -1) {
539 		err = got_error_from_errno("asprintf");
540 		path_got = NULL;
541 		goto done;
542 	}
543 
544 	head_ref_name = strdup(got_ref_get_name(head_ref));
545 	if (head_ref_name == NULL) {
546 		err = got_error_from_errno("strdup");
547 		goto done;
548 	}
549 
550 	err = write_head_ref(path_got, head_ref);
551 	if (err)
552 		goto done;
553 
554 	free(worktree->head_ref_name);
555 	worktree->head_ref_name = head_ref_name;
556 done:
557 	free(path_got);
558 	if (err)
559 		free(head_ref_name);
560 	return err;
561 }
562 
563 struct got_object_id *
564 got_worktree_get_base_commit_id(struct got_worktree *worktree)
565 {
566 	return worktree->base_commit_id;
567 }
568 
569 const struct got_error *
570 got_worktree_set_base_commit_id(struct got_worktree *worktree,
571     struct got_repository *repo, struct got_object_id *commit_id)
572 {
573 	const struct got_error *err;
574 	struct got_object *obj = NULL;
575 	char *id_str = NULL;
576 	char *path_got = NULL;
577 
578 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
579 	    GOT_WORKTREE_GOT_DIR) == -1) {
580 		err = got_error_from_errno("asprintf");
581 		path_got = NULL;
582 		goto done;
583 	}
584 
585 	err = got_object_open(&obj, repo, commit_id);
586 	if (err)
587 		return err;
588 
589 	if (obj->type != GOT_OBJ_TYPE_COMMIT) {
590 		err = got_error(GOT_ERR_OBJ_TYPE);
591 		goto done;
592 	}
593 
594 	/* Record our base commit. */
595 	err = got_object_id_str(&id_str, commit_id);
596 	if (err)
597 		goto done;
598 	err = update_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, id_str);
599 	if (err)
600 		goto done;
601 
602 	free(worktree->base_commit_id);
603 	worktree->base_commit_id = got_object_id_dup(commit_id);
604 	if (worktree->base_commit_id == NULL) {
605 		err = got_error_from_errno("got_object_id_dup");
606 		goto done;
607 	}
608 done:
609 	if (obj)
610 		got_object_close(obj);
611 	free(id_str);
612 	free(path_got);
613 	return err;
614 }
615 
616 static const struct got_error *
617 lock_worktree(struct got_worktree *worktree, int operation)
618 {
619 	if (flock(worktree->lockfd, operation | LOCK_NB) == -1)
620 		return (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
621 		    : got_error_from_errno2("flock",
622 		    got_worktree_get_root_path(worktree)));
623 	return NULL;
624 }
625 
626 static const struct got_error *
627 add_dir_on_disk(struct got_worktree *worktree, const char *path)
628 {
629 	const struct got_error *err = NULL;
630 	char *abspath;
631 
632 	if (asprintf(&abspath, "%s/%s", worktree->root_path, path) == -1)
633 		return got_error_from_errno("asprintf");
634 
635 	err = got_path_mkdir(abspath);
636 	if (err && err->code == GOT_ERR_ERRNO && errno == EEXIST) {
637 		struct stat sb;
638 		err = NULL;
639 		if (lstat(abspath, &sb) == -1) {
640 			err = got_error_from_errno2("lstat", abspath);
641 		} else if (!S_ISDIR(sb.st_mode)) {
642 			/* TODO directory is obstructed; do something */
643 			err = got_error(GOT_ERR_FILE_OBSTRUCTED);
644 		}
645 	}
646 	free(abspath);
647 	return err;
648 }
649 
650 static const struct got_error *
651 check_file_contents_equal(int *same, FILE *f1, FILE *f2)
652 {
653 	const struct got_error *err = NULL;
654 	uint8_t fbuf1[8192];
655 	uint8_t fbuf2[8192];
656 	size_t flen1 = 0, flen2 = 0;
657 
658 	*same = 1;
659 
660 	for (;;) {
661 		flen1 = fread(fbuf1, 1, sizeof(fbuf1), f1);
662 		if (flen1 == 0 && ferror(f1)) {
663 			err = got_error_from_errno("fread");
664 			break;
665 		}
666 		flen2 = fread(fbuf2, 1, sizeof(fbuf2), f2);
667 		if (flen2 == 0 && ferror(f2)) {
668 			err = got_error_from_errno("fread");
669 			break;
670 		}
671 		if (flen1 == 0) {
672 			if (flen2 != 0)
673 				*same = 0;
674 			break;
675 		} else if (flen2 == 0) {
676 			if (flen1 != 0)
677 				*same = 0;
678 			break;
679 		} else if (flen1 == flen2) {
680 			if (memcmp(fbuf1, fbuf2, flen2) != 0) {
681 				*same = 0;
682 				break;
683 			}
684 		} else {
685 			*same = 0;
686 			break;
687 		}
688 	}
689 
690 	return err;
691 }
692 
693 static const struct got_error *
694 check_files_equal(int *same, const char *f1_path, const char *f2_path)
695 {
696 	const struct got_error *err = NULL;
697 	struct stat sb;
698 	size_t size1, size2;
699 	FILE *f1 = NULL, *f2 = NULL;
700 
701 	*same = 1;
702 
703 	if (lstat(f1_path, &sb) != 0) {
704 		err = got_error_from_errno2("lstat", f1_path);
705 		goto done;
706 	}
707 	size1 = sb.st_size;
708 
709 	if (lstat(f2_path, &sb) != 0) {
710 		err = got_error_from_errno2("lstat", f2_path);
711 		goto done;
712 	}
713 	size2 = sb.st_size;
714 
715 	if (size1 != size2) {
716 		*same = 0;
717 		return NULL;
718 	}
719 
720 	f1 = fopen(f1_path, "r");
721 	if (f1 == NULL)
722 		return got_error_from_errno2("open", f1_path);
723 
724 	f2 = fopen(f2_path, "r");
725 	if (f2 == NULL) {
726 		err = got_error_from_errno2("open", f2_path);
727 		goto done;
728 	}
729 
730 	err = check_file_contents_equal(same, f1, f2);
731 done:
732 	if (f1 && fclose(f1) != 0 && err == NULL)
733 		err = got_error_from_errno("fclose");
734 	if (f2 && fclose(f2) != 0 && err == NULL)
735 		err = got_error_from_errno("fclose");
736 
737 	return err;
738 }
739 
740 /*
741  * Perform a 3-way merge where blob2 acts as the common ancestor,
742  * blob1 acts as the first derived version, and the file on disk
743  * acts as the second derived version.
744  */
745 static const struct got_error *
746 merge_blob(int *local_changes_subsumed, struct got_worktree *worktree,
747     struct got_blob_object *blob2, const char *ondisk_path,
748     const char *path, uint16_t st_mode, struct got_blob_object *blob1,
749     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
750     void *progress_arg)
751 {
752 	const struct got_error *err = NULL;
753 	int merged_fd = -1;
754 	FILE *f1 = NULL, *f2 = NULL;
755 	char *blob1_path = NULL, *blob2_path = NULL;
756 	char *merged_path = NULL, *base_path = NULL;
757 	char *id_str = NULL;
758 	char *label1 = NULL;
759 	int overlapcnt = 0;
760 	char *parent;
761 
762 	*local_changes_subsumed = 0;
763 
764 	parent = dirname(ondisk_path);
765 	if (parent == NULL)
766 		return got_error_from_errno2("dirname", ondisk_path);
767 
768 	if (asprintf(&base_path, "%s/got-merged", parent) == -1)
769 		return got_error_from_errno("asprintf");
770 
771 	err = got_opentemp_named_fd(&merged_path, &merged_fd, base_path);
772 	if (err)
773 		goto done;
774 
775 	free(base_path);
776 	if (asprintf(&base_path, "%s/got-merge-blob1", parent) == -1) {
777 		err = got_error_from_errno("asprintf");
778 		base_path = NULL;
779 		goto done;
780 	}
781 
782 	err = got_opentemp_named(&blob1_path, &f1, base_path);
783 	if (err)
784 		goto done;
785 	err = got_object_blob_dump_to_file(NULL, NULL, f1, blob1);
786 	if (err)
787 		goto done;
788 
789 	free(base_path);
790 	if (asprintf(&base_path, "%s/got-merge-blob2", parent) == -1) {
791 		err = got_error_from_errno("asprintf");
792 		base_path = NULL;
793 		goto done;
794 	}
795 
796 	err = got_opentemp_named(&blob2_path, &f2, base_path);
797 	if (err)
798 		goto done;
799 	if (blob2) {
800 		err = got_object_blob_dump_to_file(NULL, NULL, f2, blob2);
801 		if (err)
802 			goto done;
803 	} else {
804 		/*
805 		 * If the file has no blob, this is an "add vs add" conflict,
806 		 * and we simply use an empty ancestor file to make both files
807 		 * appear in the merged result in their entirety.
808 		 */
809 	}
810 
811 	err = got_object_id_str(&id_str, worktree->base_commit_id);
812 	if (err)
813 		goto done;
814 	if (asprintf(&label1, "commit %s", id_str) == -1) {
815 		err = got_error_from_errno("asprintf");
816 		goto done;
817 	}
818 
819 	err = got_merge_diff3(&overlapcnt, merged_fd, blob1_path,
820 	    blob2_path, ondisk_path, label1, path);
821 	if (err)
822 		goto done;
823 
824 	(*progress_cb)(progress_arg,
825 	    overlapcnt > 0 ? GOT_STATUS_CONFLICT : GOT_STATUS_MERGE, path);
826 
827 	if (fsync(merged_fd) != 0) {
828 		err = got_error_from_errno("fsync");
829 		goto done;
830 	}
831 
832 	/* Check if a clean merge has subsumed all local changes. */
833 	if (overlapcnt == 0) {
834 		err = check_files_equal(local_changes_subsumed, blob1_path,
835 		    merged_path);
836 		if (err)
837 			goto done;
838 	}
839 
840 	if (chmod(merged_path, st_mode) != 0) {
841 		err = got_error_from_errno2("chmod", merged_path);
842 		goto done;
843 	}
844 
845 	if (rename(merged_path, ondisk_path) != 0) {
846 		err = got_error_from_errno3("rename", merged_path,
847 		    ondisk_path);
848 		unlink(merged_path);
849 		goto done;
850 	}
851 
852 done:
853 	if (merged_fd != -1 && close(merged_fd) != 0 && err == NULL)
854 		err = got_error_from_errno("close");
855 	if (f1 && fclose(f1) != 0 && err == NULL)
856 		err = got_error_from_errno("fclose");
857 	if (f2 && fclose(f2) != 0 && err == NULL)
858 		err = got_error_from_errno("fclose");
859 	free(merged_path);
860 	free(base_path);
861 	if (blob1_path) {
862 		unlink(blob1_path);
863 		free(blob1_path);
864 	}
865 	if (blob2_path) {
866 		unlink(blob2_path);
867 		free(blob2_path);
868 	}
869 	free(id_str);
870 	free(label1);
871 	return err;
872 }
873 
874 static const struct got_error *
875 update_blob_fileindex_entry(struct got_worktree *worktree,
876     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
877     const char *ondisk_path, const char *path, struct got_blob_object *blob,
878     int update_timestamps)
879 {
880 	const struct got_error *err = NULL;
881 
882 	if (ie == NULL)
883 		ie = got_fileindex_entry_get(fileindex, path);
884 	if (ie)
885 		err = got_fileindex_entry_update(ie, ondisk_path,
886 		    blob->id.sha1, worktree->base_commit_id->sha1,
887 		    update_timestamps);
888 	else {
889 		struct got_fileindex_entry *new_ie;
890 		err = got_fileindex_entry_alloc(&new_ie, ondisk_path,
891 		    path, blob->id.sha1, worktree->base_commit_id->sha1);
892 		if (!err)
893 			err = got_fileindex_entry_add(fileindex, new_ie);
894 	}
895 	return err;
896 }
897 
898 static const struct got_error *
899 install_blob(struct got_worktree *worktree, const char *ondisk_path,
900    const char *path, uint16_t te_mode, uint16_t st_mode,
901    struct got_blob_object *blob, int restoring_missing_file,
902    int reverting_versioned_file, struct got_repository *repo,
903    got_worktree_checkout_cb progress_cb, void *progress_arg)
904 {
905 	const struct got_error *err = NULL;
906 	int fd = -1;
907 	size_t len, hdrlen;
908 	int update = 0;
909 	char *tmppath = NULL;
910 
911 	fd = open(ondisk_path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
912 	    GOT_DEFAULT_FILE_MODE);
913 	if (fd == -1) {
914 		if (errno == ENOENT) {
915 			char *parent = dirname(path);
916 			if (parent == NULL)
917 				return got_error_from_errno2("dirname", path);
918 			err = add_dir_on_disk(worktree, parent);
919 			if (err)
920 				return err;
921 			fd = open(ondisk_path,
922 			    O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
923 			    GOT_DEFAULT_FILE_MODE);
924 			if (fd == -1)
925 				return got_error_from_errno2("open",
926 				    ondisk_path);
927 		} else if (errno == EEXIST) {
928 			if (!S_ISREG(st_mode)) {
929 				/* TODO file is obstructed; do something */
930 				err = got_error(GOT_ERR_FILE_OBSTRUCTED);
931 				goto done;
932 			} else {
933 				err = got_opentemp_named_fd(&tmppath, &fd,
934 				    ondisk_path);
935 				if (err)
936 					goto done;
937 				update = 1;
938 			}
939 		} else
940 			return got_error_from_errno2("open", ondisk_path);
941 	}
942 
943 	if (restoring_missing_file)
944 		(*progress_cb)(progress_arg, GOT_STATUS_MISSING, path);
945 	else if (reverting_versioned_file)
946 		(*progress_cb)(progress_arg, GOT_STATUS_REVERT, path);
947 	else
948 		(*progress_cb)(progress_arg,
949 		    update ? GOT_STATUS_UPDATE : GOT_STATUS_ADD, path);
950 
951 	hdrlen = got_object_blob_get_hdrlen(blob);
952 	do {
953 		const uint8_t *buf = got_object_blob_get_read_buf(blob);
954 		err = got_object_blob_read_block(&len, blob);
955 		if (err)
956 			break;
957 		if (len > 0) {
958 			/* Skip blob object header first time around. */
959 			ssize_t outlen = write(fd, buf + hdrlen, len - hdrlen);
960 			if (outlen == -1) {
961 				err = got_error_from_errno("write");
962 				goto done;
963 			} else if (outlen != len - hdrlen) {
964 				err = got_error(GOT_ERR_IO);
965 				goto done;
966 			}
967 			hdrlen = 0;
968 		}
969 	} while (len != 0);
970 
971 	if (fsync(fd) != 0) {
972 		err = got_error_from_errno("fsync");
973 		goto done;
974 	}
975 
976 	if (update) {
977 		if (rename(tmppath, ondisk_path) != 0) {
978 			err = got_error_from_errno3("rename", tmppath,
979 			    ondisk_path);
980 			unlink(tmppath);
981 			goto done;
982 		}
983 	}
984 
985 	if (te_mode & S_IXUSR) {
986 		if (chmod(ondisk_path, st_mode | S_IXUSR) == -1) {
987 			err = got_error_from_errno2("chmod", ondisk_path);
988 			goto done;
989 		}
990 	} else {
991 		if (chmod(ondisk_path, st_mode & ~S_IXUSR) == -1) {
992 			err = got_error_from_errno2("chmod", ondisk_path);
993 			goto done;
994 		}
995 	}
996 
997 done:
998 	if (fd != -1 && close(fd) != 0 && err == NULL)
999 		err = got_error_from_errno("close");
1000 	free(tmppath);
1001 	return err;
1002 }
1003 
1004 /* Upgrade STATUS_MODIFY to STATUS_CONFLICT if a conflict marker is found. */
1005 static const struct got_error *
1006 get_modified_file_content_status(unsigned char *status, FILE *f)
1007 {
1008 	const struct got_error *err = NULL;
1009 	const char *markers[3] = {
1010 		GOT_DIFF_CONFLICT_MARKER_BEGIN,
1011 		GOT_DIFF_CONFLICT_MARKER_SEP,
1012 		GOT_DIFF_CONFLICT_MARKER_END
1013 	};
1014 	int i = 0;
1015 	char *line;
1016 	size_t len;
1017 	const char delim[3] = {'\0', '\0', '\0'};
1018 
1019 	while (*status == GOT_STATUS_MODIFY) {
1020 		line = fparseln(f, &len, NULL, delim, 0);
1021 		if (line == NULL) {
1022 			if (feof(f))
1023 				break;
1024 			err = got_ferror(f, GOT_ERR_IO);
1025 			break;
1026 		}
1027 
1028 		if (strncmp(line, markers[i], strlen(markers[i])) == 0) {
1029 			if (strcmp(markers[i], GOT_DIFF_CONFLICT_MARKER_END)
1030 			    == 0)
1031 				*status = GOT_STATUS_CONFLICT;
1032 			else
1033 				i++;
1034 		}
1035 	}
1036 
1037 	return err;
1038 }
1039 
1040 static const struct got_error *
1041 get_file_status(unsigned char *status, struct stat *sb,
1042     struct got_fileindex_entry *ie, const char *abspath,
1043     struct got_repository *repo)
1044 {
1045 	const struct got_error *err = NULL;
1046 	struct got_object_id id;
1047 	size_t hdrlen;
1048 	FILE *f = NULL;
1049 	uint8_t fbuf[8192];
1050 	struct got_blob_object *blob = NULL;
1051 	size_t flen, blen;
1052 
1053 	*status = GOT_STATUS_NO_CHANGE;
1054 
1055 	if (lstat(abspath, sb) == -1) {
1056 		if (errno == ENOENT) {
1057 			if (ie) {
1058 				if (got_fileindex_entry_has_file_on_disk(ie))
1059 					*status = GOT_STATUS_MISSING;
1060 				else
1061 					*status = GOT_STATUS_DELETE;
1062 				sb->st_mode =
1063 				    ((ie->mode >> GOT_FILEIDX_MODE_PERMS_SHIFT)
1064 				    & (S_IRWXU | S_IRWXG | S_IRWXO));
1065 			} else
1066 				sb->st_mode = GOT_DEFAULT_FILE_MODE;
1067 			return NULL;
1068 		}
1069 		return got_error_from_errno2("lstat", abspath);
1070 	}
1071 
1072 	if (!S_ISREG(sb->st_mode)) {
1073 		*status = GOT_STATUS_OBSTRUCTED;
1074 		return NULL;
1075 	}
1076 
1077 	if (ie == NULL)
1078 		return NULL;
1079 
1080 	if (!got_fileindex_entry_has_file_on_disk(ie)) {
1081 		*status = GOT_STATUS_DELETE;
1082 		return NULL;
1083 	} else if (!got_fileindex_entry_has_blob(ie)) {
1084 		*status = GOT_STATUS_ADD;
1085 		return NULL;
1086 	}
1087 
1088 	if (ie->ctime_sec == sb->st_ctime &&
1089 	    ie->ctime_nsec == sb->st_ctimensec &&
1090 	    ie->mtime_sec == sb->st_mtime &&
1091 	    ie->mtime_sec == sb->st_mtime &&
1092 	    ie->mtime_nsec == sb->st_mtimensec &&
1093 	    ie->size == (sb->st_size & 0xffffffff))
1094 		return NULL;
1095 
1096 	memcpy(id.sha1, ie->blob_sha1, sizeof(id.sha1));
1097 	err = got_object_open_as_blob(&blob, repo, &id, sizeof(fbuf));
1098 	if (err)
1099 		return err;
1100 
1101 	f = fopen(abspath, "r");
1102 	if (f == NULL) {
1103 		err = got_error_from_errno2("fopen", abspath);
1104 		goto done;
1105 	}
1106 	hdrlen = got_object_blob_get_hdrlen(blob);
1107 	for (;;) {
1108 		const uint8_t *bbuf = got_object_blob_get_read_buf(blob);
1109 		err = got_object_blob_read_block(&blen, blob);
1110 		if (err)
1111 			goto done;
1112 		/* Skip length of blob object header first time around. */
1113 		flen = fread(fbuf, 1, sizeof(fbuf) - hdrlen, f);
1114 		if (flen == 0 && ferror(f)) {
1115 			err = got_error_from_errno("fread");
1116 			goto done;
1117 		}
1118 		if (blen == 0) {
1119 			if (flen != 0)
1120 				*status = GOT_STATUS_MODIFY;
1121 			break;
1122 		} else if (flen == 0) {
1123 			if (blen != 0)
1124 				*status = GOT_STATUS_MODIFY;
1125 			break;
1126 		} else if (blen - hdrlen == flen) {
1127 			/* Skip blob object header first time around. */
1128 			if (memcmp(bbuf + hdrlen, fbuf, flen) != 0) {
1129 				*status = GOT_STATUS_MODIFY;
1130 				break;
1131 			}
1132 		} else {
1133 			*status = GOT_STATUS_MODIFY;
1134 			break;
1135 		}
1136 		hdrlen = 0;
1137 	}
1138 
1139 	if (*status == GOT_STATUS_MODIFY) {
1140 		rewind(f);
1141 		err = get_modified_file_content_status(status, f);
1142 	}
1143 done:
1144 	if (blob)
1145 		got_object_blob_close(blob);
1146 	if (f)
1147 		fclose(f);
1148 	return err;
1149 }
1150 
1151 static const struct got_error *
1152 update_blob(struct got_worktree *worktree,
1153     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
1154     struct got_tree_entry *te, const char *path,
1155     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1156     void *progress_arg)
1157 {
1158 	const struct got_error *err = NULL;
1159 	struct got_blob_object *blob = NULL;
1160 	char *ondisk_path;
1161 	unsigned char status = GOT_STATUS_NO_CHANGE;
1162 	struct stat sb;
1163 
1164 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
1165 		return got_error_from_errno("asprintf");
1166 
1167 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1168 	if (err)
1169 		goto done;
1170 
1171 	if (status == GOT_STATUS_OBSTRUCTED) {
1172 		(*progress_cb)(progress_arg, status, path);
1173 		goto done;
1174 	}
1175 
1176 	if (ie && status != GOT_STATUS_MISSING) {
1177 		if (got_fileindex_entry_has_commit(ie) &&
1178 		    memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
1179 		    SHA1_DIGEST_LENGTH) == 0) {
1180 			(*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
1181 			    path);
1182 			goto done;
1183 		}
1184 		if (got_fileindex_entry_has_blob(ie) &&
1185 		    memcmp(ie->blob_sha1, te->id->sha1,
1186 		    SHA1_DIGEST_LENGTH) == 0)
1187 			goto done;
1188 	}
1189 
1190 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
1191 	if (err)
1192 		goto done;
1193 
1194 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_ADD) {
1195 		int update_timestamps;
1196 		struct got_blob_object *blob2 = NULL;
1197 		if (got_fileindex_entry_has_blob(ie)) {
1198 			struct got_object_id id2;
1199 			memcpy(id2.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1200 			err = got_object_open_as_blob(&blob2, repo, &id2, 8192);
1201 			if (err)
1202 				goto done;
1203 		}
1204 		err = merge_blob(&update_timestamps, worktree, blob2,
1205 		    ondisk_path, path, sb.st_mode, blob, repo,
1206 		    progress_cb, progress_arg);
1207 		if (blob2)
1208 			got_object_blob_close(blob2);
1209 		/*
1210 		 * Do not update timestamps of files with local changes.
1211 		 * Otherwise, a future status walk would treat them as
1212 		 * unmodified files again.
1213 		 */
1214 		err = got_fileindex_entry_update(ie, ondisk_path,
1215 		    blob->id.sha1, worktree->base_commit_id->sha1,
1216 		    update_timestamps);
1217 	} else if (status == GOT_STATUS_DELETE) {
1218 		(*progress_cb)(progress_arg, GOT_STATUS_MERGE, path);
1219 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1220 		    ondisk_path, path, blob, 0);
1221 		if (err)
1222 			goto done;
1223 	} else {
1224 		err = install_blob(worktree, ondisk_path, path, te->mode,
1225 		    sb.st_mode, blob, status == GOT_STATUS_MISSING, 0,
1226 		    repo, progress_cb, progress_arg);
1227 		if (err)
1228 			goto done;
1229 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1230 		    ondisk_path, path, blob, 1);
1231 		if (err)
1232 			goto done;
1233 	}
1234 	got_object_blob_close(blob);
1235 done:
1236 	free(ondisk_path);
1237 	return err;
1238 }
1239 
1240 static const struct got_error *
1241 remove_ondisk_file(const char *root_path, const char *path)
1242 {
1243 	const struct got_error *err = NULL;
1244 	char *ondisk_path = NULL;
1245 
1246 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
1247 		return got_error_from_errno("asprintf");
1248 
1249 	if (unlink(ondisk_path) == -1) {
1250 		if (errno != ENOENT)
1251 			err = got_error_from_errno2("unlink", ondisk_path);
1252 	} else {
1253 		char *parent = dirname(ondisk_path);
1254 		while (parent && strcmp(parent, root_path) != 0) {
1255 			if (rmdir(parent) == -1) {
1256 				if (errno != ENOTEMPTY)
1257 					err = got_error_from_errno2("rmdir",
1258 					    parent);
1259 				break;
1260 			}
1261 			parent = dirname(parent);
1262 		}
1263 	}
1264 	free(ondisk_path);
1265 	return err;
1266 }
1267 
1268 static const struct got_error *
1269 delete_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
1270     struct got_fileindex_entry *ie, struct got_repository *repo,
1271     got_worktree_checkout_cb progress_cb, void *progress_arg)
1272 {
1273 	const struct got_error *err = NULL;
1274 	unsigned char status;
1275 	struct stat sb;
1276 	char *ondisk_path;
1277 
1278 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, ie->path)
1279 	    == -1)
1280 		return got_error_from_errno("asprintf");
1281 
1282 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1283 	if (err)
1284 		return err;
1285 
1286 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_CONFLICT ||
1287 	    status == GOT_STATUS_ADD) {
1288 		(*progress_cb)(progress_arg, GOT_STATUS_MERGE, ie->path);
1289 		/*
1290 		 * Preserve the working file and change the deleted blob's
1291 		 * entry into a schedule-add entry.
1292 		 */
1293 		err = got_fileindex_entry_update(ie, ondisk_path, NULL, NULL,
1294 		    0);
1295 		if (err)
1296 			return err;
1297 	} else {
1298 		(*progress_cb)(progress_arg, GOT_STATUS_DELETE, ie->path);
1299 		if (status == GOT_STATUS_NO_CHANGE) {
1300 			err = remove_ondisk_file(worktree->root_path, ie->path);
1301 			if (err)
1302 				return err;
1303 		}
1304 		got_fileindex_entry_remove(fileindex, ie);
1305 	}
1306 
1307 	return err;
1308 }
1309 
1310 struct diff_cb_arg {
1311     struct got_fileindex *fileindex;
1312     struct got_worktree *worktree;
1313     struct got_repository *repo;
1314     got_worktree_checkout_cb progress_cb;
1315     void *progress_arg;
1316     got_worktree_cancel_cb cancel_cb;
1317     void *cancel_arg;
1318 };
1319 
1320 static const struct got_error *
1321 diff_old_new(void *arg, struct got_fileindex_entry *ie,
1322     struct got_tree_entry *te, const char *parent_path)
1323 {
1324 	struct diff_cb_arg *a = arg;
1325 
1326 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1327 		return got_error(GOT_ERR_CANCELLED);
1328 
1329 	return update_blob(a->worktree, a->fileindex, ie, te,
1330 	    ie->path, a->repo, a->progress_cb, a->progress_arg);
1331 }
1332 
1333 static const struct got_error *
1334 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1335 {
1336 	struct diff_cb_arg *a = arg;
1337 
1338 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1339 		return got_error(GOT_ERR_CANCELLED);
1340 
1341 	return delete_blob(a->worktree, a->fileindex, ie,
1342 	    a->repo, a->progress_cb, a->progress_arg);
1343 }
1344 
1345 static const struct got_error *
1346 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
1347 {
1348 	struct diff_cb_arg *a = arg;
1349 	const struct got_error *err;
1350 	char *path;
1351 
1352 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1353 		return got_error(GOT_ERR_CANCELLED);
1354 
1355 	if (asprintf(&path, "%s%s%s", parent_path,
1356 	    parent_path[0] ? "/" : "", te->name)
1357 	    == -1)
1358 		return got_error_from_errno("asprintf");
1359 
1360 	if (S_ISDIR(te->mode))
1361 		err = add_dir_on_disk(a->worktree, path);
1362 	else
1363 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
1364 		    a->repo, a->progress_cb, a->progress_arg);
1365 
1366 	free(path);
1367 	return err;
1368 }
1369 
1370 const struct got_error *
1371 got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
1372 {
1373 	const struct got_error *err = NULL;
1374 	char *uuidstr = NULL;
1375 	uint32_t uuid_status;
1376 
1377 	*refname = NULL;
1378 
1379 	uuid_to_string(&worktree->uuid, &uuidstr, &uuid_status);
1380 	if (uuid_status != uuid_s_ok)
1381 		return got_error_uuid(uuid_status);
1382 
1383 	if (asprintf(refname, "%s-%s", GOT_WORKTREE_BASE_REF_PREFIX, uuidstr)
1384 	    == -1) {
1385 		err = got_error_from_errno("asprintf");
1386 		*refname = NULL;
1387 	}
1388 	free(uuidstr);
1389 	return err;
1390 }
1391 
1392 /*
1393  * Prevent Git's garbage collector from deleting our base commit by
1394  * setting a reference to our base commit's ID.
1395  */
1396 static const struct got_error *
1397 ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
1398 {
1399 	const struct got_error *err = NULL;
1400 	struct got_reference *ref = NULL;
1401 	char *refname;
1402 
1403 	err = got_worktree_get_base_ref_name(&refname, worktree);
1404 	if (err)
1405 		return err;
1406 
1407 	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
1408 	if (err)
1409 		goto done;
1410 
1411 	err = got_ref_write(ref, repo);
1412 done:
1413 	free(refname);
1414 	if (ref)
1415 		got_ref_close(ref);
1416 	return err;
1417 }
1418 
1419 static const struct got_error *
1420 open_fileindex(struct got_fileindex **fileindex, char **fileindex_path,
1421    struct got_worktree *worktree)
1422 {
1423 	const struct got_error *err = NULL;
1424 	FILE *index = NULL;
1425 
1426 	*fileindex_path = NULL;
1427 	*fileindex = got_fileindex_alloc();
1428 	if (*fileindex == NULL)
1429 		return got_error_from_errno("got_fileindex_alloc");
1430 
1431 	if (asprintf(fileindex_path, "%s/%s/%s", worktree->root_path,
1432 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1433 		err = got_error_from_errno("asprintf");
1434 		*fileindex_path = NULL;
1435 		goto done;
1436 	}
1437 
1438 	index = fopen(*fileindex_path, "rb");
1439 	if (index == NULL) {
1440 		if (errno != ENOENT)
1441 			err = got_error_from_errno2("fopen", *fileindex_path);
1442 	} else {
1443 		err = got_fileindex_read(*fileindex, index);
1444 		if (fclose(index) != 0 && err == NULL)
1445 			err = got_error_from_errno("fclose");
1446 	}
1447 done:
1448 	if (err) {
1449 		free(*fileindex_path);
1450 		*fileindex_path = NULL;
1451 		free(*fileindex);
1452 		*fileindex = NULL;
1453 	}
1454 	return err;
1455 }
1456 
1457 struct bump_base_commit_id_arg {
1458 	struct got_object_id *base_commit_id;
1459 	const char *path;
1460 	size_t path_len;
1461 	const char *entry_name;
1462 };
1463 
1464 /* Bump base commit ID of all files within an updated part of the work tree. */
1465 static const struct got_error *
1466 bump_base_commit_id(void *arg, struct got_fileindex_entry *ie)
1467 {
1468 	struct bump_base_commit_id_arg *a = arg;
1469 
1470 	if (a->entry_name) {
1471 		if (strcmp(ie->path, a->path) != 0)
1472 			return NULL;
1473 	} else if (!got_path_is_child(ie->path, a->path, a->path_len))
1474 		return NULL;
1475 
1476 	memcpy(ie->commit_sha1, a->base_commit_id->sha1, SHA1_DIGEST_LENGTH);
1477 	return NULL;
1478 }
1479 
1480 static const struct got_error *
1481 sync_fileindex(struct got_fileindex *fileindex, const char *fileindex_path)
1482 {
1483 	const struct got_error *err = NULL;
1484 	char *new_fileindex_path = NULL;
1485 	FILE *new_index = NULL;
1486 
1487 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1488 	    fileindex_path);
1489 	if (err)
1490 		goto done;
1491 
1492 	err = got_fileindex_write(fileindex, new_index);
1493 	if (err)
1494 		goto done;
1495 
1496 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1497 		err = got_error_from_errno3("rename", new_fileindex_path,
1498 		    fileindex_path);
1499 		unlink(new_fileindex_path);
1500 	}
1501 done:
1502 	if (new_index)
1503 		fclose(new_index);
1504 	free(new_fileindex_path);
1505 	return err;
1506 }
1507 
1508 const struct got_error *
1509 got_worktree_checkout_files(struct got_worktree *worktree, const char *path,
1510     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1511     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1512 {
1513 	const struct got_error *err = NULL, *unlockerr, *checkout_err = NULL;
1514 	struct got_commit_object *commit = NULL;
1515 	struct got_object_id *tree_id = NULL;
1516 	struct got_tree_object *tree = NULL;
1517 	struct got_fileindex *fileindex = NULL;
1518 	char *fileindex_path = NULL;
1519 	struct got_fileindex_diff_tree_cb diff_cb;
1520 	struct diff_cb_arg arg;
1521 	char *relpath = NULL, *entry_name = NULL;
1522 
1523 	err = lock_worktree(worktree, LOCK_EX);
1524 	if (err)
1525 		return err;
1526 
1527 	/*
1528 	 * Read the file index.
1529 	 * Checking out files is supposed to be an idempotent operation.
1530 	 * If the on-disk file index is incomplete we will try to complete it.
1531 	 */
1532 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1533 	if (err)
1534 		goto done;
1535 
1536 	err = ref_base_commit(worktree, repo);
1537 	if (err)
1538 		goto done;
1539 
1540 	err = got_object_open_as_commit(&commit, repo,
1541 	   worktree->base_commit_id);
1542 	if (err)
1543 		goto done;
1544 
1545 	if (path[0]) {
1546 		char *tree_path;
1547 		int obj_type;
1548 		relpath = strdup(path);
1549 		if (relpath == NULL) {
1550 			err = got_error_from_errno("strdup");
1551 			goto done;
1552 		}
1553 		if (asprintf(&tree_path, "%s%s%s", worktree->path_prefix,
1554 		    got_path_is_root_dir(worktree->path_prefix) ? "" : "/",
1555 		    path) == -1) {
1556 			err = got_error_from_errno("asprintf");
1557 			goto done;
1558 		}
1559 		err = got_object_id_by_path(&tree_id, repo,
1560 		    worktree->base_commit_id, tree_path);
1561 		free(tree_path);
1562 		if (err)
1563 			goto done;
1564 		err = got_object_get_type(&obj_type, repo, tree_id);
1565 		if (err)
1566 			goto done;
1567 		if (obj_type == GOT_OBJ_TYPE_BLOB) {
1568 			/* Split provided path into parent dir + entry name. */
1569 			if (strchr(path, '/')  == NULL) {
1570 				relpath = strdup("");
1571 				if (relpath == NULL) {
1572 					err = got_error_from_errno("strdup");
1573 					goto done;
1574 				}
1575 				tree_path = strdup(worktree->path_prefix);
1576 				if (tree_path == NULL) {
1577 					err = got_error_from_errno("strdup");
1578 					goto done;
1579 				}
1580 			} else {
1581 				err = got_path_dirname(&relpath, path);
1582 				if (err)
1583 					goto done;
1584 				if (asprintf(&tree_path, "%s%s%s",
1585 				    worktree->path_prefix,
1586 				    got_path_is_root_dir(
1587 				    worktree->path_prefix) ? "" : "/",
1588 				    relpath) == -1) {
1589 					err = got_error_from_errno("asprintf");
1590 					goto done;
1591 				}
1592 			}
1593 			err = got_object_id_by_path(&tree_id, repo,
1594 			    worktree->base_commit_id, tree_path);
1595 			free(tree_path);
1596 			if (err)
1597 				goto done;
1598 			entry_name = basename(path);
1599 			if (entry_name == NULL) {
1600 				err = got_error_from_errno2("basename", path);
1601 				goto done;
1602 			}
1603 		}
1604 	} else {
1605 		relpath = strdup("");
1606 		if (relpath == NULL) {
1607 			err = got_error_from_errno("strdup");
1608 			goto done;
1609 		}
1610 		err = got_object_id_by_path(&tree_id, repo,
1611 		    worktree->base_commit_id, worktree->path_prefix);
1612 		if (err)
1613 			goto done;
1614 	}
1615 
1616 	err = got_object_open_as_tree(&tree, repo, tree_id);
1617 	if (err)
1618 		goto done;
1619 
1620 	if (entry_name &&
1621 	    got_object_tree_find_entry(tree, entry_name) == NULL) {
1622 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
1623 		goto done;
1624 	}
1625 
1626 	diff_cb.diff_old_new = diff_old_new;
1627 	diff_cb.diff_old = diff_old;
1628 	diff_cb.diff_new = diff_new;
1629 	arg.fileindex = fileindex;
1630 	arg.worktree = worktree;
1631 	arg.repo = repo;
1632 	arg.progress_cb = progress_cb;
1633 	arg.progress_arg = progress_arg;
1634 	arg.cancel_cb = cancel_cb;
1635 	arg.cancel_arg = cancel_arg;
1636 	checkout_err = got_fileindex_diff_tree(fileindex, tree, relpath,
1637 	    entry_name, repo, &diff_cb, &arg);
1638 
1639 	if (checkout_err == NULL) {
1640 		struct bump_base_commit_id_arg bbc_arg;
1641 		bbc_arg.base_commit_id = worktree->base_commit_id;
1642 		bbc_arg.entry_name = entry_name;
1643 		bbc_arg.path = path;
1644 		bbc_arg.path_len = strlen(path);
1645 		err = got_fileindex_for_each_entry_safe(fileindex,
1646 		    bump_base_commit_id, &bbc_arg);
1647 		if (err)
1648 			goto done;
1649 	}
1650 
1651 	/* Try to sync the fileindex back to disk in any case. */
1652 	err = sync_fileindex(fileindex, fileindex_path);
1653 done:
1654 	free(fileindex_path);
1655 	free(relpath);
1656 	if (tree)
1657 		got_object_tree_close(tree);
1658 	if (commit)
1659 		got_object_commit_close(commit);
1660 	got_fileindex_free(fileindex);
1661 	if (checkout_err)
1662 		err = checkout_err;
1663 	unlockerr = lock_worktree(worktree, LOCK_SH);
1664 	if (unlockerr && err == NULL)
1665 		err = unlockerr;
1666 	return err;
1667 }
1668 
1669 struct merge_file_cb_arg {
1670     struct got_worktree *worktree;
1671     struct got_fileindex *fileindex;
1672     got_worktree_checkout_cb progress_cb;
1673     void *progress_arg;
1674     got_worktree_cancel_cb cancel_cb;
1675     void *cancel_arg;
1676 };
1677 
1678 static const struct got_error *
1679 merge_file_cb(void *arg, struct got_blob_object *blob1,
1680     struct got_blob_object *blob2, struct got_object_id *id1,
1681     struct got_object_id *id2, const char *path1, const char *path2,
1682     struct got_repository *repo)
1683 {
1684 	static const struct got_error *err = NULL;
1685 	struct merge_file_cb_arg *a = arg;
1686 	struct got_fileindex_entry *ie;
1687 	char *ondisk_path = NULL;
1688 	struct stat sb;
1689 	unsigned char status;
1690 	int local_changes_subsumed;
1691 
1692 	if (blob1 && blob2) {
1693 		ie = got_fileindex_entry_get(a->fileindex, path2);
1694 		if (ie == NULL) {
1695 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MISSING,
1696 			    path2);
1697 			return NULL;
1698 		}
1699 
1700 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1701 		    path2) == -1)
1702 			return got_error_from_errno("asprintf");
1703 
1704 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1705 		if (err)
1706 			goto done;
1707 
1708 		if (status == GOT_STATUS_DELETE) {
1709 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MERGE,
1710 			    path2);
1711 			goto done;
1712 		}
1713 		if (status != GOT_STATUS_NO_CHANGE &&
1714 		    status != GOT_STATUS_MODIFY &&
1715 		    status != GOT_STATUS_CONFLICT &&
1716 		    status != GOT_STATUS_ADD) {
1717 			(*a->progress_cb)(a->progress_arg, status, path2);
1718 			goto done;
1719 		}
1720 
1721 		err = merge_blob(&local_changes_subsumed, a->worktree, blob1,
1722 		    ondisk_path, path2, sb.st_mode, blob2, repo,
1723 		    a->progress_cb, a->progress_arg);
1724 	} else if (blob1) {
1725 		ie = got_fileindex_entry_get(a->fileindex, path1);
1726 		if (ie == NULL) {
1727 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MISSING,
1728 			    path2);
1729 			return NULL;
1730 		}
1731 
1732 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1733 		    path1) == -1)
1734 			return got_error_from_errno("asprintf");
1735 
1736 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1737 		if (err)
1738 			goto done;
1739 
1740 		switch (status) {
1741 		case GOT_STATUS_NO_CHANGE:
1742 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE,
1743 			    path1);
1744 			err = remove_ondisk_file(a->worktree->root_path, path1);
1745 			if (err)
1746 				goto done;
1747 			if (ie)
1748 				got_fileindex_entry_mark_deleted_from_disk(ie);
1749 			break;
1750 		case GOT_STATUS_DELETE:
1751 		case GOT_STATUS_MISSING:
1752 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE,
1753 			    path1);
1754 			if (ie)
1755 				got_fileindex_entry_mark_deleted_from_disk(ie);
1756 			break;
1757 		case GOT_STATUS_ADD:
1758 		case GOT_STATUS_MODIFY:
1759 		case GOT_STATUS_CONFLICT:
1760 			(*a->progress_cb)(a->progress_arg,
1761 			    GOT_STATUS_CANNOT_DELETE, path1);
1762 			break;
1763 		case GOT_STATUS_OBSTRUCTED:
1764 			(*a->progress_cb)(a->progress_arg, status, path1);
1765 			break;
1766 		default:
1767 			break;
1768 		}
1769 	} else if (blob2) {
1770 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1771 		    path2) == -1)
1772 			return got_error_from_errno("asprintf");
1773 		ie = got_fileindex_entry_get(a->fileindex, path2);
1774 		if (ie) {
1775 			err = get_file_status(&status, &sb, ie, ondisk_path,
1776 			    repo);
1777 			if (err)
1778 				goto done;
1779 			if (status != GOT_STATUS_NO_CHANGE &&
1780 			    status != GOT_STATUS_MODIFY &&
1781 			    status != GOT_STATUS_CONFLICT &&
1782 			    status != GOT_STATUS_ADD) {
1783 				(*a->progress_cb)(a->progress_arg, status,
1784 				    path2);
1785 				goto done;
1786 			}
1787 			err = merge_blob(&local_changes_subsumed, a->worktree,
1788 			    NULL, ondisk_path, path2, sb.st_mode, blob2, repo,
1789 			    a->progress_cb, a->progress_arg);
1790 			if (status == GOT_STATUS_DELETE) {
1791 				err = update_blob_fileindex_entry(a->worktree,
1792 				    a->fileindex, ie, ondisk_path, ie->path,
1793 				    blob2, 0);
1794 				if (err)
1795 					goto done;
1796 			}
1797 		} else {
1798 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1799 			err = install_blob(a->worktree, ondisk_path, path2,
1800 			    /* XXX get this from parent tree! */
1801 			    GOT_DEFAULT_FILE_MODE,
1802 			    sb.st_mode, blob2, 0, 0, repo,
1803 			    a->progress_cb, a->progress_arg);
1804 			if (err)
1805 				goto done;
1806 			err = got_fileindex_entry_alloc(&ie,
1807 			    ondisk_path, path2, NULL, NULL);
1808 			if (err)
1809 				goto done;
1810 			err = got_fileindex_entry_add(a->fileindex, ie);
1811 			if (err) {
1812 				got_fileindex_entry_free(ie);
1813 				goto done;
1814 			}
1815 		}
1816 	}
1817 done:
1818 	free(ondisk_path);
1819 	return err;
1820 }
1821 
1822 struct check_merge_ok_arg {
1823 	struct got_worktree *worktree;
1824 	struct got_repository *repo;
1825 };
1826 
1827 static const struct got_error *
1828 check_merge_ok(void *arg, struct got_fileindex_entry *ie)
1829 {
1830 	const struct got_error *err = NULL;
1831 	struct check_merge_ok_arg *a = arg;
1832 	unsigned char status;
1833 	struct stat sb;
1834 	char *ondisk_path;
1835 
1836 	/* Reject merges into a work tree with mixed base commits. */
1837 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
1838 	    SHA1_DIGEST_LENGTH))
1839 		return got_error(GOT_ERR_MIXED_COMMITS);
1840 
1841 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
1842 	    == -1)
1843 		return got_error_from_errno("asprintf");
1844 
1845 	/* Reject merges into a work tree with conflicted files. */
1846 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
1847 	if (err)
1848 		return err;
1849 	if (status == GOT_STATUS_CONFLICT)
1850 		return got_error(GOT_ERR_CONFLICTS);
1851 
1852 	return NULL;
1853 }
1854 
1855 const struct got_error *
1856 got_worktree_merge_files(struct got_worktree *worktree,
1857     struct got_object_id *commit_id1, struct got_object_id *commit_id2,
1858     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1859     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1860 {
1861 	const struct got_error *err = NULL, *unlockerr;
1862 	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
1863 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1864 	struct merge_file_cb_arg arg;
1865 	char *fileindex_path = NULL;
1866 	struct got_fileindex *fileindex = NULL;
1867 	struct check_merge_ok_arg mok_arg;
1868 
1869 	err = lock_worktree(worktree, LOCK_EX);
1870 	if (err)
1871 		return err;
1872 
1873 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1874 	if (err)
1875 		goto done;
1876 
1877 	mok_arg.worktree = worktree;
1878 	mok_arg.repo = repo;
1879 	err = got_fileindex_for_each_entry_safe(fileindex, check_merge_ok,
1880 	    &mok_arg);
1881 	if (err)
1882 		goto done;
1883 
1884 	if (commit_id1) {
1885 		err = got_object_id_by_path(&tree_id1, repo, commit_id1,
1886 		    worktree->path_prefix);
1887 		if (err)
1888 			goto done;
1889 
1890 		err = got_object_open_as_tree(&tree1, repo, tree_id1);
1891 		if (err)
1892 			goto done;
1893 	}
1894 
1895 	err = got_object_id_by_path(&tree_id2, repo, commit_id2,
1896 	    worktree->path_prefix);
1897 	if (err)
1898 		goto done;
1899 
1900 	err = got_object_open_as_tree(&tree2, repo, tree_id2);
1901 	if (err)
1902 		goto done;
1903 
1904 	arg.worktree = worktree;
1905 	arg.fileindex = fileindex;
1906 	arg.progress_cb = progress_cb;
1907 	arg.progress_arg = progress_arg;
1908 	arg.cancel_cb = cancel_cb;
1909 	arg.cancel_arg = cancel_arg;
1910 	err = got_diff_tree(tree1, tree2, "", "", repo, merge_file_cb, &arg);
1911 	if (err)
1912 		goto done;
1913 
1914 	err = sync_fileindex(fileindex, fileindex_path);
1915 done:
1916 	got_fileindex_free(fileindex);
1917 	if (tree1)
1918 		got_object_tree_close(tree1);
1919 	if (tree2)
1920 		got_object_tree_close(tree2);
1921 
1922 	unlockerr = lock_worktree(worktree, LOCK_SH);
1923 	if (unlockerr && err == NULL)
1924 		err = unlockerr;
1925 	return err;
1926 }
1927 
1928 struct diff_dir_cb_arg {
1929     struct got_fileindex *fileindex;
1930     struct got_worktree *worktree;
1931     const char *status_path;
1932     size_t status_path_len;
1933     struct got_repository *repo;
1934     got_worktree_status_cb status_cb;
1935     void *status_arg;
1936     got_worktree_cancel_cb cancel_cb;
1937     void *cancel_arg;
1938 };
1939 
1940 static const struct got_error *
1941 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
1942     got_worktree_status_cb status_cb, void *status_arg,
1943     struct got_repository *repo)
1944 {
1945 	const struct got_error *err = NULL;
1946 	unsigned char status = GOT_STATUS_NO_CHANGE;
1947 	struct stat sb;
1948 	struct got_object_id blob_id, commit_id;
1949 
1950 	err = get_file_status(&status, &sb, ie, abspath, repo);
1951 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
1952 		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1953 		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
1954 		err = (*status_cb)(status_arg, status, ie->path, &blob_id,
1955 		    &commit_id);
1956 	}
1957 	return err;
1958 }
1959 
1960 static const struct got_error *
1961 status_old_new(void *arg, struct got_fileindex_entry *ie,
1962     struct dirent *de, const char *parent_path)
1963 {
1964 	const struct got_error *err = NULL;
1965 	struct diff_dir_cb_arg *a = arg;
1966 	char *abspath;
1967 
1968 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1969 		return got_error(GOT_ERR_CANCELLED);
1970 
1971 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
1972 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
1973 		return NULL;
1974 
1975 	if (parent_path[0]) {
1976 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
1977 		    parent_path, de->d_name) == -1)
1978 			return got_error_from_errno("asprintf");
1979 	} else {
1980 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
1981 		    de->d_name) == -1)
1982 			return got_error_from_errno("asprintf");
1983 	}
1984 
1985 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
1986 	    a->repo);
1987 	free(abspath);
1988 	return err;
1989 }
1990 
1991 static const struct got_error *
1992 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1993 {
1994 	struct diff_dir_cb_arg *a = arg;
1995 	struct got_object_id blob_id, commit_id;
1996 	unsigned char status;
1997 
1998 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1999 		return got_error(GOT_ERR_CANCELLED);
2000 
2001 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2002 		return NULL;
2003 
2004 	memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2005 	memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2006 	if (got_fileindex_entry_has_file_on_disk(ie))
2007 		status = GOT_STATUS_MISSING;
2008 	else
2009 		status = GOT_STATUS_DELETE;
2010 	return (*a->status_cb)(a->status_arg, status, ie->path, &blob_id,
2011 	    &commit_id);
2012 }
2013 
2014 static const struct got_error *
2015 status_new(void *arg, struct dirent *de, const char *parent_path)
2016 {
2017 	const struct got_error *err = NULL;
2018 	struct diff_dir_cb_arg *a = arg;
2019 	char *path = NULL;
2020 
2021 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2022 		return got_error(GOT_ERR_CANCELLED);
2023 
2024 	if (de->d_type == DT_DIR)
2025 		return NULL;
2026 
2027 	/* XXX ignore symlinks for now */
2028 	if (de->d_type == DT_LNK)
2029 		return NULL;
2030 
2031 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2032 		return NULL;
2033 
2034 	if (parent_path[0]) {
2035 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
2036 			return got_error_from_errno("asprintf");
2037 	} else {
2038 		path = de->d_name;
2039 	}
2040 
2041 	err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED, path,
2042 	    NULL, NULL);
2043 	if (parent_path[0])
2044 		free(path);
2045 	return err;
2046 }
2047 
2048 const struct got_error *
2049 got_worktree_status(struct got_worktree *worktree, const char *path,
2050     struct got_repository *repo, got_worktree_status_cb status_cb,
2051     void *status_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2052 {
2053 	const struct got_error *err = NULL;
2054 	DIR *workdir = NULL;
2055 	char *fileindex_path = NULL;
2056 	struct got_fileindex *fileindex = NULL;
2057 	FILE *index = NULL;
2058 	struct got_fileindex_diff_dir_cb fdiff_cb;
2059 	struct diff_dir_cb_arg arg;
2060 	char *ondisk_path = NULL;
2061 
2062 	fileindex = got_fileindex_alloc();
2063 	if (fileindex == NULL) {
2064 		err = got_error_from_errno("got_fileindex_alloc");
2065 		goto done;
2066 	}
2067 
2068 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
2069 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
2070 		err = got_error_from_errno("asprintf");
2071 		fileindex_path = NULL;
2072 		goto done;
2073 	}
2074 
2075 	index = fopen(fileindex_path, "rb");
2076 	if (index == NULL) {
2077 		if (errno != ENOENT) {
2078 			err = got_error_from_errno2("fopen", fileindex_path);
2079 			goto done;
2080 		}
2081 	} else {
2082 		err = got_fileindex_read(fileindex, index);
2083 		fclose(index);
2084 		if (err)
2085 			goto done;
2086 	}
2087 
2088 	if (asprintf(&ondisk_path, "%s%s%s",
2089 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
2090 		err = got_error_from_errno("asprintf");
2091 		goto done;
2092 	}
2093 	workdir = opendir(ondisk_path);
2094 	if (workdir == NULL) {
2095 		if (errno == ENOTDIR || errno == ENOENT) {
2096 			struct got_fileindex_entry *ie;
2097 			ie = got_fileindex_entry_get(fileindex, path);
2098 			if (ie == NULL) {
2099 				err = got_error(GOT_ERR_BAD_PATH);
2100 				goto done;
2101 			}
2102 			err = report_file_status(ie, ondisk_path,
2103 			    status_cb, status_arg, repo);
2104 			goto done;
2105 		} else {
2106 			err = got_error_from_errno2("opendir", ondisk_path);
2107 			goto done;
2108 		}
2109 	}
2110 	fdiff_cb.diff_old_new = status_old_new;
2111 	fdiff_cb.diff_old = status_old;
2112 	fdiff_cb.diff_new = status_new;
2113 	arg.fileindex = fileindex;
2114 	arg.worktree = worktree;
2115 	arg.status_path = path;
2116 	arg.status_path_len = strlen(path);
2117 	arg.repo = repo;
2118 	arg.status_cb = status_cb;
2119 	arg.status_arg = status_arg;
2120 	arg.cancel_cb = cancel_cb;
2121 	arg.cancel_arg = cancel_arg;
2122 	err = got_fileindex_diff_dir(fileindex, workdir, worktree->root_path,
2123 	    path, repo, &fdiff_cb, &arg);
2124 done:
2125 	if (workdir)
2126 		closedir(workdir);
2127 	free(ondisk_path);
2128 	free(fileindex_path);
2129 	got_fileindex_free(fileindex);
2130 	return err;
2131 }
2132 
2133 const struct got_error *
2134 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
2135     const char *arg)
2136 {
2137 	const struct got_error *err = NULL;
2138 	char *resolved, *path = NULL;
2139 	size_t len;
2140 
2141 	*wt_path = NULL;
2142 
2143 	resolved = realpath(arg, NULL);
2144 	if (resolved == NULL)
2145 		return got_error_from_errno2("realpath", arg);
2146 
2147 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
2148 	    strlen(got_worktree_get_root_path(worktree)))) {
2149 		err = got_error(GOT_ERR_BAD_PATH);
2150 		goto done;
2151 	}
2152 
2153 	if (strlen(resolved) > strlen(got_worktree_get_root_path(worktree))) {
2154 		err = got_path_skip_common_ancestor(&path,
2155 		    got_worktree_get_root_path(worktree), resolved);
2156 		if (err)
2157 			goto done;
2158 	} else {
2159 		path = strdup("");
2160 		if (path == NULL) {
2161 			err = got_error_from_errno("strdup");
2162 			goto done;
2163 		}
2164 	}
2165 
2166 	/* XXX status walk can't deal with trailing slash! */
2167 	len = strlen(path);
2168 	while (path[len - 1] == '/') {
2169 		path[len - 1] = '\0';
2170 		len--;
2171 	}
2172 done:
2173 	free(resolved);
2174 	if (err == NULL)
2175 		*wt_path = path;
2176 	else
2177 		free(path);
2178 	return err;
2179 }
2180 
2181 static const struct got_error *
2182 schedule_addition(const char *ondisk_path, struct got_fileindex *fileindex,
2183     const char *relpath, got_worktree_status_cb status_cb, void *status_arg,
2184     struct got_repository *repo)
2185 {
2186 	const struct got_error *err = NULL;
2187 	struct got_fileindex_entry *ie;
2188 
2189 	/* Re-adding an existing entry is a no-op. */
2190 	if (got_fileindex_entry_get(fileindex, relpath) != NULL)
2191 		return NULL;
2192 
2193 	err = got_fileindex_entry_alloc(&ie, ondisk_path, relpath, NULL, NULL);
2194 	if (err)
2195 		return err;
2196 
2197 	err = got_fileindex_entry_add(fileindex, ie);
2198 	if (err) {
2199 		got_fileindex_entry_free(ie);
2200 		return err;
2201 	}
2202 
2203 	return report_file_status(ie, relpath, status_cb, status_arg, repo);
2204 }
2205 
2206 const struct got_error *
2207 got_worktree_schedule_add(struct got_worktree *worktree,
2208     struct got_pathlist_head *ondisk_paths,
2209     got_worktree_status_cb status_cb, void *status_arg,
2210     struct got_repository *repo)
2211 {
2212 	struct got_fileindex *fileindex = NULL;
2213 	char *fileindex_path = NULL;
2214 	FILE *index = NULL;
2215 	const struct got_error *err = NULL, *unlockerr = NULL;
2216 	struct got_pathlist_entry *pe;
2217 
2218 	err = lock_worktree(worktree, LOCK_EX);
2219 	if (err)
2220 		return err;
2221 
2222 
2223 	fileindex = got_fileindex_alloc();
2224 	if (fileindex == NULL) {
2225 		err = got_error_from_errno("got_fileindex_alloc");
2226 		goto done;
2227 	}
2228 
2229 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
2230 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
2231 		err = got_error_from_errno("asprintf");
2232 		fileindex_path = NULL;
2233 		goto done;
2234 	}
2235 
2236 	index = fopen(fileindex_path, "rb");
2237 	if (index == NULL) {
2238 		err = got_error_from_errno2("fopen", fileindex_path);
2239 		goto done;
2240 	}
2241 
2242 	err = got_fileindex_read(fileindex, index);
2243 	if (err)
2244 		goto done;
2245 
2246 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2247 		char *relpath;
2248 		err = got_path_skip_common_ancestor(&relpath,
2249 		    got_worktree_get_root_path(worktree), pe->path);
2250 		if (err)
2251 			goto done;
2252 		err = schedule_addition(pe->path, fileindex, relpath,
2253 		    status_cb, status_arg, repo);
2254 		free(relpath);
2255 		if (err)
2256 			goto done;
2257 	}
2258 
2259 	err = sync_fileindex(fileindex, fileindex_path);
2260 done:
2261 	if (index) {
2262 		if (fclose(index) != 0 && err == NULL)
2263 			err = got_error_from_errno("fclose");
2264 	}
2265 	if (fileindex)
2266 		got_fileindex_free(fileindex);
2267 	unlockerr = lock_worktree(worktree, LOCK_SH);
2268 	if (unlockerr && err == NULL)
2269 		err = unlockerr;
2270 	return err;
2271 }
2272 
2273 static const struct got_error *
2274 schedule_for_deletion(const char *ondisk_path, struct got_fileindex *fileindex,
2275     const char *relpath, int delete_local_mods,
2276     got_worktree_status_cb status_cb, void *status_arg,
2277     struct got_repository *repo)
2278 {
2279 	const struct got_error *err = NULL;
2280 	struct got_fileindex_entry *ie = NULL;
2281 	unsigned char status;
2282 	struct stat sb;
2283 
2284 	ie = got_fileindex_entry_get(fileindex, relpath);
2285 	if (ie == NULL)
2286 		return got_error(GOT_ERR_BAD_PATH);
2287 
2288 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2289 	if (err)
2290 		return err;
2291 
2292 	if (status != GOT_STATUS_NO_CHANGE) {
2293 		if (status == GOT_STATUS_DELETE)
2294 			return got_error_set_errno(ENOENT, ondisk_path);
2295 		if (status != GOT_STATUS_MODIFY)
2296 			return got_error(GOT_ERR_FILE_STATUS);
2297 		if (!delete_local_mods)
2298 			return got_error(GOT_ERR_FILE_MODIFIED);
2299 	}
2300 
2301 	if (unlink(ondisk_path) != 0)
2302 		return got_error_from_errno2("unlink", ondisk_path);
2303 
2304 	got_fileindex_entry_mark_deleted_from_disk(ie);
2305 	return report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2306 }
2307 
2308 const struct got_error *
2309 got_worktree_schedule_delete(struct got_worktree *worktree,
2310     struct got_pathlist_head *ondisk_paths, int delete_local_mods,
2311     got_worktree_status_cb status_cb, void *status_arg,
2312     struct got_repository *repo)
2313 {
2314 	struct got_fileindex *fileindex = NULL;
2315 	char *fileindex_path = NULL;
2316 	FILE *index = NULL;
2317 	const struct got_error *err = NULL, *unlockerr = NULL;
2318 	struct got_pathlist_entry *pe;
2319 
2320 	err = lock_worktree(worktree, LOCK_EX);
2321 	if (err)
2322 		return err;
2323 
2324 	fileindex = got_fileindex_alloc();
2325 	if (fileindex == NULL) {
2326 		err = got_error_from_errno("got_fileindex_alloc");
2327 		goto done;
2328 	}
2329 
2330 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
2331 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
2332 		err = got_error_from_errno("asprintf");
2333 		fileindex_path = NULL;
2334 		goto done;
2335 	}
2336 
2337 	index = fopen(fileindex_path, "rb");
2338 	if (index == NULL) {
2339 		err = got_error_from_errno2("fopen", fileindex_path);
2340 		goto done;
2341 	}
2342 
2343 	err = got_fileindex_read(fileindex, index);
2344 	if (err)
2345 		goto done;
2346 
2347 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2348 		char *relpath;
2349 		err = got_path_skip_common_ancestor(&relpath,
2350 		    got_worktree_get_root_path(worktree), pe->path);
2351 		if (err)
2352 			goto done;
2353 		err = schedule_for_deletion(pe->path, fileindex, relpath,
2354 		    delete_local_mods, status_cb, status_arg, repo);
2355 		free(relpath);
2356 		if (err)
2357 			goto done;
2358 	}
2359 
2360 	err = sync_fileindex(fileindex, fileindex_path);
2361 	if (err)
2362 		goto done;
2363 done:
2364 	if (index) {
2365 		if (fclose(index) != 0 && err == NULL)
2366 			err = got_error_from_errno("fclose");
2367 	}
2368 	if (fileindex)
2369 		got_fileindex_free(fileindex);
2370 	unlockerr = lock_worktree(worktree, LOCK_SH);
2371 	if (unlockerr && err == NULL)
2372 		err = unlockerr;
2373 	return err;
2374 }
2375 
2376 const struct got_error *
2377 got_worktree_revert(struct got_worktree *worktree,
2378     const char *ondisk_path,
2379     got_worktree_checkout_cb progress_cb, void *progress_arg,
2380     struct got_repository *repo)
2381 {
2382 	struct got_fileindex *fileindex = NULL;
2383 	struct got_fileindex_entry *ie = NULL;
2384 	char *relpath, *fileindex_path = NULL;
2385 	char *tree_path = NULL, *parent_path, *te_name;
2386 	FILE *index = NULL;
2387 	const struct got_error *err = NULL, *unlockerr = NULL;
2388 	struct got_tree_object *tree = NULL;
2389 	struct got_object_id id, *tree_id = NULL;
2390 	const struct got_tree_entry *te;
2391 	struct got_blob_object *blob = NULL;
2392 	unsigned char status;
2393 	struct stat sb;
2394 
2395 	err = lock_worktree(worktree, LOCK_EX);
2396 	if (err)
2397 		return err;
2398 
2399 	err = got_path_skip_common_ancestor(&relpath,
2400 	    got_worktree_get_root_path(worktree), ondisk_path);
2401 	if (err)
2402 		goto done;
2403 
2404 	fileindex = got_fileindex_alloc();
2405 	if (fileindex == NULL) {
2406 		err = got_error_from_errno("got_fileindex_alloc");
2407 		goto done;
2408 	}
2409 
2410 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
2411 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
2412 		err = got_error_from_errno("asprintf");
2413 		fileindex_path = NULL;
2414 		goto done;
2415 	}
2416 
2417 	index = fopen(fileindex_path, "rb");
2418 	if (index == NULL) {
2419 		err = got_error_from_errno2("fopen", fileindex_path);
2420 		goto done;
2421 	}
2422 
2423 	err = got_fileindex_read(fileindex, index);
2424 	if (err)
2425 		goto done;
2426 
2427 	ie = got_fileindex_entry_get(fileindex, relpath);
2428 	if (ie == NULL) {
2429 		err = got_error(GOT_ERR_BAD_PATH);
2430 		goto done;
2431 	}
2432 
2433 	/* Construct in-repository path of tree which contains this blob. */
2434 	err = got_path_dirname(&parent_path, ie->path);
2435 	if (err) {
2436 		if (err->code != GOT_ERR_BAD_PATH)
2437 			goto done;
2438 		parent_path = "/";
2439 	}
2440 	if (got_path_is_root_dir(worktree->path_prefix)) {
2441 		tree_path = strdup(parent_path);
2442 		if (tree_path == NULL) {
2443 			err = got_error_from_errno("strdup");
2444 			goto done;
2445 		}
2446 	} else {
2447 		if (got_path_is_root_dir(parent_path)) {
2448 			tree_path = strdup(worktree->path_prefix);
2449 			if (tree_path == NULL) {
2450 				err = got_error_from_errno("strdup");
2451 				goto done;
2452 			}
2453 		} else {
2454 			if (asprintf(&tree_path, "%s/%s",
2455 			    worktree->path_prefix, parent_path) == -1) {
2456 				err = got_error_from_errno("asprintf");
2457 				goto done;
2458 			}
2459 		}
2460 	}
2461 
2462 	err = got_object_id_by_path(&tree_id, repo, worktree->base_commit_id,
2463 	    tree_path);
2464 	if (err)
2465 		goto done;
2466 
2467 	err = got_object_open_as_tree(&tree, repo, tree_id);
2468 	if (err)
2469 		goto done;
2470 
2471 	te_name = basename(ie->path);
2472 	if (te_name == NULL) {
2473 		err = got_error_from_errno2("basename", ie->path);
2474 		goto done;
2475 	}
2476 
2477 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2478 	if (err)
2479 		goto done;
2480 
2481 	te = got_object_tree_find_entry(tree, te_name);
2482 	if (te == NULL && status != GOT_STATUS_ADD) {
2483 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
2484 		goto done;
2485 	}
2486 
2487 	switch (status) {
2488 	case GOT_STATUS_ADD:
2489 		(*progress_cb)(progress_arg, GOT_STATUS_REVERT, ie->path);
2490 		got_fileindex_entry_remove(fileindex, ie);
2491 		break;
2492 	case GOT_STATUS_DELETE:
2493 	case GOT_STATUS_MODIFY:
2494 	case GOT_STATUS_CONFLICT:
2495 	case GOT_STATUS_MISSING:
2496 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2497 		err = got_object_open_as_blob(&blob, repo, &id, 8192);
2498 		if (err)
2499 			goto done;
2500 		err = install_blob(worktree, ondisk_path, ie->path,
2501 		    te->mode, sb.st_mode, blob, 0, 1, repo, progress_cb,
2502 		    progress_arg);
2503 		if (err)
2504 			goto done;
2505 		if (status == GOT_STATUS_DELETE) {
2506 			err = update_blob_fileindex_entry(worktree,
2507 			    fileindex, ie, ondisk_path, ie->path, blob, 1);
2508 			if (err)
2509 				goto done;
2510 		}
2511 		break;
2512 	default:
2513 			goto done;
2514 	}
2515 
2516 	err = sync_fileindex(fileindex, fileindex_path);
2517 	if (err)
2518 		goto done;
2519 done:
2520 	free(relpath);
2521 	free(tree_path);
2522 	if (blob)
2523 		got_object_blob_close(blob);
2524 	if (tree)
2525 		got_object_tree_close(tree);
2526 	free(tree_id);
2527 	if (index) {
2528 		if (fclose(index) != 0 && err == NULL)
2529 			err = got_error_from_errno("fclose");
2530 	}
2531 	if (fileindex)
2532 		got_fileindex_free(fileindex);
2533 	unlockerr = lock_worktree(worktree, LOCK_SH);
2534 	if (unlockerr && err == NULL)
2535 		err = unlockerr;
2536 	return err;
2537 }
2538 
2539 static void
2540 free_commitable(struct got_commitable *ct)
2541 {
2542 	free(ct->path);
2543 	free(ct->in_repo_path);
2544 	free(ct->ondisk_path);
2545 	free(ct->blob_id);
2546 	free(ct->base_blob_id);
2547 	free(ct->base_commit_id);
2548 	free(ct);
2549 }
2550 
2551 struct collect_commitables_arg {
2552 	struct got_pathlist_head *commitable_paths;
2553 	struct got_repository *repo;
2554 	struct got_worktree *worktree;
2555 };
2556 
2557 static const struct got_error *
2558 collect_commitables(void *arg, unsigned char status, const char *relpath,
2559     struct got_object_id *blob_id, struct got_object_id *commit_id)
2560 {
2561 	struct collect_commitables_arg *a = arg;
2562 	const struct got_error *err = NULL;
2563 	struct got_commitable *ct = NULL;
2564 	struct got_pathlist_entry *new = NULL;
2565 	char *parent_path = NULL, *path = NULL;
2566 	struct stat sb;
2567 
2568 	if (status == GOT_STATUS_CONFLICT)
2569 		return got_error(GOT_ERR_COMMIT_CONFLICT);
2570 
2571 	if (status != GOT_STATUS_MODIFY && status != GOT_STATUS_ADD &&
2572 	    status != GOT_STATUS_DELETE)
2573 		return NULL;
2574 
2575 	if (asprintf(&path, "/%s", relpath) == -1) {
2576 		err = got_error_from_errno("asprintf");
2577 		goto done;
2578 	}
2579 	if (strcmp(path, "/") == 0) {
2580 		parent_path = strdup("");
2581 		if (parent_path == NULL)
2582 			return got_error_from_errno("strdup");
2583 	} else {
2584 		err = got_path_dirname(&parent_path, path);
2585 		if (err)
2586 			return err;
2587 	}
2588 
2589 	ct = calloc(1, sizeof(*ct));
2590 	if (ct == NULL) {
2591 		err = got_error_from_errno("calloc");
2592 		goto done;
2593 	}
2594 
2595 	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
2596 	    relpath) == -1) {
2597 		err = got_error_from_errno("asprintf");
2598 		goto done;
2599 	}
2600 	if (status == GOT_STATUS_DELETE) {
2601 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
2602 	} else {
2603 		if (lstat(ct->ondisk_path, &sb) != 0) {
2604 			err = got_error_from_errno2("lstat", ct->ondisk_path);
2605 			goto done;
2606 		}
2607 		ct->mode = sb.st_mode;
2608 	}
2609 
2610 	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
2611 	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
2612 	    relpath) == -1) {
2613 		err = got_error_from_errno("asprintf");
2614 		goto done;
2615 	}
2616 
2617 	ct->status = status;
2618 	ct->blob_id = NULL; /* will be filled in when blob gets created */
2619 	if (ct->status != GOT_STATUS_ADD) {
2620 		ct->base_blob_id = got_object_id_dup(blob_id);
2621 		if (ct->base_blob_id == NULL) {
2622 			err = got_error_from_errno("got_object_id_dup");
2623 			goto done;
2624 		}
2625 		ct->base_commit_id = got_object_id_dup(commit_id);
2626 		if (ct->base_commit_id == NULL) {
2627 			err = got_error_from_errno("got_object_id_dup");
2628 			goto done;
2629 		}
2630 	}
2631 	ct->path = strdup(path);
2632 	if (ct->path == NULL) {
2633 		err = got_error_from_errno("strdup");
2634 		goto done;
2635 	}
2636 	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
2637 done:
2638 	if (ct && (err || new == NULL))
2639 		free_commitable(ct);
2640 	free(parent_path);
2641 	free(path);
2642 	return err;
2643 }
2644 
2645 static const struct got_error *write_tree(struct got_object_id **,
2646     struct got_tree_object *, const char *, struct got_pathlist_head *,
2647     got_worktree_status_cb status_cb, void *status_arg,
2648     struct got_repository *);
2649 
2650 static const struct got_error *
2651 write_subtree(struct got_object_id **new_subtree_id,
2652     struct got_tree_entry *te, const char *parent_path,
2653     struct got_pathlist_head *commitable_paths,
2654     got_worktree_status_cb status_cb, void *status_arg,
2655     struct got_repository *repo)
2656 {
2657 	const struct got_error *err = NULL;
2658 	struct got_tree_object *subtree;
2659 	char *subpath;
2660 
2661 	if (asprintf(&subpath, "%s%s%s", parent_path,
2662 	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
2663 		return got_error_from_errno("asprintf");
2664 
2665 	err = got_object_open_as_tree(&subtree, repo, te->id);
2666 	if (err)
2667 		return err;
2668 
2669 	err = write_tree(new_subtree_id, subtree, subpath, commitable_paths,
2670 	    status_cb, status_arg, repo);
2671 	got_object_tree_close(subtree);
2672 	free(subpath);
2673 	return err;
2674 }
2675 
2676 static const struct got_error *
2677 match_ct_parent_path(int *match, struct got_commitable *ct, const char *path)
2678 {
2679 	const struct got_error *err = NULL;
2680 	char *ct_parent_path = NULL;
2681 
2682 	*match = 0;
2683 
2684 	if (strchr(ct->path, '/') == NULL) {
2685 		*match = got_path_is_root_dir(path);
2686 		return NULL;
2687 	}
2688 
2689 	err = got_path_dirname(&ct_parent_path, ct->path);
2690 	if (err)
2691 		return err;
2692 	*match = (strcmp(path, ct_parent_path) == 0);
2693 	free(ct_parent_path);
2694 	return err;
2695 }
2696 
2697 static mode_t
2698 get_ct_file_mode(struct got_commitable *ct)
2699 {
2700 	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
2701 }
2702 
2703 static const struct got_error *
2704 alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
2705     struct got_tree_entry *te, struct got_commitable *ct)
2706 {
2707 	const struct got_error *err = NULL;
2708 
2709 	*new_te = NULL;
2710 
2711 	err = got_object_tree_entry_dup(new_te, te);
2712 	if (err)
2713 		goto done;
2714 
2715 	(*new_te)->mode = get_ct_file_mode(ct);
2716 
2717 	free((*new_te)->id);
2718 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2719 	if ((*new_te)->id == NULL) {
2720 		err = got_error_from_errno("got_object_id_dup");
2721 		goto done;
2722 	}
2723 done:
2724 	if (err && *new_te) {
2725 		got_object_tree_entry_close(*new_te);
2726 		*new_te = NULL;
2727 	}
2728 	return err;
2729 }
2730 
2731 static const struct got_error *
2732 alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
2733     struct got_commitable *ct)
2734 {
2735 	const struct got_error *err = NULL;
2736 	char *ct_name;
2737 
2738 	 *new_te = NULL;
2739 
2740 	*new_te = calloc(1, sizeof(**new_te));
2741 	if (*new_te == NULL)
2742 		return got_error_from_errno("calloc");
2743 
2744 	ct_name = basename(ct->path);
2745 	if (ct_name == NULL) {
2746 		err = got_error_from_errno2("basename", ct->path);
2747 		goto done;
2748 	}
2749 	(*new_te)->name = strdup(ct_name);
2750 	if ((*new_te)->name == NULL) {
2751 		err = got_error_from_errno("strdup");
2752 		goto done;
2753 	}
2754 
2755 	(*new_te)->mode = get_ct_file_mode(ct);
2756 
2757 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2758 	if ((*new_te)->id == NULL) {
2759 		err = got_error_from_errno("got_object_id_dup");
2760 		goto done;
2761 	}
2762 done:
2763 	if (err && *new_te) {
2764 		got_object_tree_entry_close(*new_te);
2765 		*new_te = NULL;
2766 	}
2767 	return err;
2768 }
2769 
2770 static const struct got_error *
2771 insert_tree_entry(struct got_tree_entry *new_te,
2772     struct got_pathlist_head *paths)
2773 {
2774 	const struct got_error *err = NULL;
2775 	struct got_pathlist_entry *new_pe;
2776 
2777 	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
2778 	if (err)
2779 		return err;
2780 	if (new_pe == NULL)
2781 		return got_error(GOT_ERR_TREE_DUP_ENTRY);
2782 	return NULL;
2783 }
2784 
2785 static const struct got_error *
2786 report_ct_status(struct got_commitable *ct,
2787     got_worktree_status_cb status_cb, void *status_arg)
2788 {
2789 	const char *ct_path = ct->path;
2790 	while (ct_path[0] == '/')
2791 		ct_path++;
2792 	return (*status_cb)(status_arg, ct->status, ct_path, ct->blob_id, NULL);
2793 }
2794 
2795 static const struct got_error *
2796 match_modified_subtree(int *modified, struct got_tree_entry *te,
2797     const char *base_tree_path, struct got_pathlist_head *commitable_paths)
2798 {
2799 	const struct got_error *err = NULL;
2800 	struct got_pathlist_entry *pe;
2801 	char *te_path;
2802 
2803 	*modified = 0;
2804 
2805 	if (asprintf(&te_path, "%s%s%s", base_tree_path,
2806 	    got_path_is_root_dir(base_tree_path) ? "" : "/",
2807 	    te->name) == -1)
2808 		return got_error_from_errno("asprintf");
2809 
2810 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2811 		struct got_commitable *ct = pe->data;
2812 		*modified = got_path_is_child(ct->in_repo_path, te_path,
2813 		    strlen(te_path));
2814 		 if (*modified)
2815 			break;
2816 	}
2817 
2818 	free(te_path);
2819 	return err;
2820 }
2821 
2822 static const struct got_error *
2823 match_deleted_or_modified_ct(struct got_commitable **ctp,
2824     struct got_tree_entry *te, const char *base_tree_path,
2825     struct got_pathlist_head *commitable_paths)
2826 {
2827 	const struct got_error *err = NULL;
2828 	struct got_pathlist_entry *pe;
2829 
2830 	*ctp = NULL;
2831 
2832 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2833 		struct got_commitable *ct = pe->data;
2834 		char *ct_name = NULL;
2835 		int path_matches;
2836 
2837 		if (ct->status != GOT_STATUS_MODIFY &&
2838 		    ct->status != GOT_STATUS_DELETE)
2839 			continue;
2840 
2841 		if (got_object_id_cmp(ct->base_blob_id, te->id) != 0)
2842 			continue;
2843 
2844 		 err = match_ct_parent_path(&path_matches, ct, base_tree_path);
2845 		 if (err)
2846 			return err;
2847 		if (!path_matches)
2848 			continue;
2849 
2850 		ct_name = basename(pe->path);
2851 		if (ct_name == NULL)
2852 			return got_error_from_errno2("basename", pe->path);
2853 
2854 		if (strcmp(te->name, ct_name) != 0)
2855 			continue;
2856 
2857 		*ctp = ct;
2858 		break;
2859 	}
2860 
2861 	return err;
2862 }
2863 
2864 static const struct got_error *
2865 write_tree(struct got_object_id **new_tree_id,
2866     struct got_tree_object *base_tree, const char *path_base_tree,
2867     struct got_pathlist_head *commitable_paths,
2868     got_worktree_status_cb status_cb, void *status_arg,
2869     struct got_repository *repo)
2870 {
2871 	const struct got_error *err = NULL;
2872 	const struct got_tree_entries *base_entries = NULL;
2873 	struct got_pathlist_head paths;
2874 	struct got_tree_entries new_tree_entries;
2875 	struct got_tree_entry *te, *new_te = NULL;
2876 	struct got_pathlist_entry *pe;
2877 
2878 	TAILQ_INIT(&paths);
2879 	new_tree_entries.nentries = 0;
2880 	SIMPLEQ_INIT(&new_tree_entries.head);
2881 
2882 	/* Insert, and recurse into, newly added entries first. */
2883 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2884 		struct got_commitable *ct = pe->data;
2885 		char *child_path = NULL, *slash;
2886 
2887 		if (ct->status != GOT_STATUS_ADD ||
2888 		    (ct->flags & GOT_COMMITABLE_ADDED))
2889 			continue;
2890 
2891 		 if (!got_path_is_child(pe->path, path_base_tree,
2892 		     strlen(path_base_tree)))
2893 			continue;
2894 
2895 		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
2896 		    pe->path);
2897 		if (err)
2898 			goto done;
2899 
2900 		slash = strchr(child_path, '/');
2901 		if (slash == NULL) {
2902 			err = alloc_added_blob_tree_entry(&new_te, ct);
2903 			if (err)
2904 				goto done;
2905 			err = report_ct_status(ct, status_cb, status_arg);
2906 			if (err)
2907 				goto done;
2908 			ct->flags |= GOT_COMMITABLE_ADDED;
2909 		} else {
2910 			char *subtree_path;
2911 
2912 			*slash = '\0'; /* trim trailing path components */
2913 			if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
2914 			    got_path_is_root_dir(path_base_tree) ? "" : "/",
2915 			    child_path) == -1) {
2916 				err = got_error_from_errno("asprintf");
2917 				goto done;
2918 			}
2919 
2920 			new_te = calloc(1, sizeof(*new_te));
2921 			new_te->mode = S_IFDIR;
2922 			new_te->name = strdup(child_path);
2923 			if (new_te->name == NULL) {
2924 				err = got_error_from_errno("strdup");
2925 				got_object_tree_entry_close(new_te);
2926 				new_te = NULL;
2927 				goto done;
2928 			}
2929 			err = write_tree(&new_te->id, NULL, subtree_path,
2930 			    commitable_paths, status_cb, status_arg, repo);
2931 			free(subtree_path);
2932 			if (err) {
2933 				got_object_tree_entry_close(new_te);
2934 				new_te = NULL;
2935 				goto done;
2936 			}
2937 		}
2938 		err = insert_tree_entry(new_te, &paths);
2939 		if (err)
2940 			goto done;
2941 	}
2942 
2943 	if (base_tree) {
2944 		/* Handle modified and deleted entries. */
2945 		base_entries = got_object_tree_get_entries(base_tree);
2946 		SIMPLEQ_FOREACH(te, &base_entries->head, entry) {
2947 			struct got_commitable *ct = NULL;
2948 
2949 			if (S_ISDIR(te->mode)) {
2950 				int modified;
2951 				err = got_object_tree_entry_dup(&new_te, te);
2952 				if (err)
2953 					goto done;
2954 				err = match_modified_subtree(&modified, te,
2955 				    path_base_tree, commitable_paths);
2956 				if (err)
2957 					goto done;
2958 				/* Avoid recursion into unmodified subtrees. */
2959 				if (modified) {
2960 					free(new_te->id);
2961 					err = write_subtree(&new_te->id, te,
2962 					    path_base_tree, commitable_paths,
2963 					    status_cb, status_arg, repo);
2964 					if (err)
2965 						goto done;
2966 				}
2967 				err = insert_tree_entry(new_te, &paths);
2968 				if (err)
2969 					goto done;
2970 				continue;
2971 			}
2972 
2973 			err = match_deleted_or_modified_ct(&ct, te,
2974 			    path_base_tree, commitable_paths);
2975 			if (ct) {
2976 				/* NB: Deleted entries get dropped here. */
2977 				if (ct->status == GOT_STATUS_MODIFY) {
2978 					err = alloc_modified_blob_tree_entry(
2979 					    &new_te, te, ct);
2980 					if (err)
2981 						goto done;
2982 					err = insert_tree_entry(new_te, &paths);
2983 					if (err)
2984 						goto done;
2985 				}
2986 				err = report_ct_status(ct, status_cb,
2987 				    status_arg);
2988 				if (err)
2989 					goto done;
2990 			} else {
2991 				/* Entry is unchanged; just copy it. */
2992 				err = got_object_tree_entry_dup(&new_te, te);
2993 				if (err)
2994 					goto done;
2995 				err = insert_tree_entry(new_te, &paths);
2996 				if (err)
2997 					goto done;
2998 			}
2999 		}
3000 	}
3001 
3002 	/* Write new list of entries; deleted entries have been dropped. */
3003 	TAILQ_FOREACH(pe, &paths, entry) {
3004 		struct got_tree_entry *te = pe->data;
3005 		new_tree_entries.nentries++;
3006 		SIMPLEQ_INSERT_TAIL(&new_tree_entries.head, te, entry);
3007 	}
3008 	err = got_object_tree_create(new_tree_id, &new_tree_entries, repo);
3009 done:
3010 	got_object_tree_entries_close(&new_tree_entries);
3011 	got_pathlist_free(&paths);
3012 	return err;
3013 }
3014 
3015 static const struct got_error *
3016 update_fileindex_after_commit(struct got_pathlist_head *commitable_paths,
3017     struct got_object_id *new_base_commit_id, struct got_worktree *worktree)
3018 {
3019 	const struct got_error *err = NULL;
3020 	char *fileindex_path = NULL;
3021 	struct got_fileindex *fileindex = NULL;
3022 	struct got_pathlist_entry *pe;
3023 
3024 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3025 	if (err)
3026 		return err;
3027 
3028 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3029 		struct got_fileindex_entry *ie;
3030 		struct got_commitable *ct = pe->data;
3031 
3032 		ie = got_fileindex_entry_get(fileindex, pe->path);
3033 		if (ie) {
3034 			if (ct->status == GOT_STATUS_DELETE) {
3035 				got_fileindex_entry_remove(fileindex, ie);
3036 				got_fileindex_entry_free(ie);
3037 			} else
3038 				err = got_fileindex_entry_update(ie,
3039 				    ct->ondisk_path, ct->blob_id->sha1,
3040 				    new_base_commit_id->sha1, 1);
3041 		} else {
3042 			err = got_fileindex_entry_alloc(&ie,
3043 			    ct->ondisk_path, pe->path, ct->blob_id->sha1,
3044 			    new_base_commit_id->sha1);
3045 			if (err)
3046 				goto done;
3047 			err = got_fileindex_entry_add(fileindex, ie);
3048 			if (err)
3049 				goto done;
3050 		}
3051 	}
3052 
3053 	err = sync_fileindex(fileindex, fileindex_path);
3054 done:
3055 	free(fileindex_path);
3056 	got_fileindex_free(fileindex);
3057 	return err;
3058 }
3059 
3060 static const struct got_error *
3061 check_ct_out_of_date(struct got_commitable *ct, struct got_repository *repo,
3062 	struct got_object_id *head_commit_id)
3063 {
3064 	const struct got_error *err = NULL;
3065 	struct got_object_id *id_in_head;
3066 
3067 	/*
3068 	 * Require that modified/deleted files are based on the branch head.
3069 	 * This requirement could be relaxed to force less update operations
3070 	 * on users but, for now, we want to play it safe and see how it goes.
3071 	 *
3072 	 * If this check is relaxed, it must still ensure that no modifications
3073 	 * were made to files *and their parents* in commits between the file's
3074 	 * base commit and the branch head. Otherwise, tree conflicts will not
3075 	 * be detected reliably.
3076 	 */
3077 	if (ct->status != GOT_STATUS_ADD) {
3078 		if (got_object_id_cmp(ct->base_commit_id, head_commit_id) != 0)
3079 			return got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3080 		return NULL;
3081 	}
3082 
3083 	/* Require that added files don't exist in the branch head. */
3084 	err = got_object_id_by_path(&id_in_head, repo, head_commit_id,
3085 	    ct->in_repo_path);
3086 	if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
3087 		return err;
3088 	if (id_in_head) {
3089 		free(id_in_head);
3090 		return got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3091 	}
3092 
3093 	free(id_in_head);
3094 	return NULL;
3095 }
3096 
3097 const struct got_error *
3098 got_worktree_commit(struct got_object_id **new_commit_id,
3099     struct got_worktree *worktree, const char *ondisk_path,
3100     const char *author, const char *committer,
3101     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3102     got_worktree_status_cb status_cb, void *status_arg,
3103     struct got_repository *repo)
3104 {
3105 	const struct got_error *err = NULL, *unlockerr = NULL;
3106 	struct collect_commitables_arg cc_arg;
3107 	struct got_pathlist_head commitable_paths;
3108 	struct got_pathlist_entry *pe;
3109 	char *relpath = NULL;
3110 	const char *head_ref_name = NULL;
3111 	struct got_reference *head_ref = NULL;
3112 	struct got_commit_object *head_commit = NULL;
3113 	struct got_object_id *head_commit_id = NULL;
3114 	struct got_reference *head_ref2 = NULL;
3115 	struct got_object_id *head_commit_id2 = NULL;
3116 	struct got_tree_object *head_tree = NULL;
3117 	struct got_object_id *new_tree_id = NULL;
3118 	struct got_object_id_queue parent_ids;
3119 	struct got_object_qid *pid = NULL;
3120 	char *logmsg = NULL;
3121 
3122 	*new_commit_id = NULL;
3123 
3124 	TAILQ_INIT(&commitable_paths);
3125 	SIMPLEQ_INIT(&parent_ids);
3126 
3127 	if (ondisk_path) {
3128 		err = got_path_skip_common_ancestor(&relpath,
3129 		    worktree->root_path, ondisk_path);
3130 		if (err)
3131 			return err;
3132 	}
3133 
3134 	err = lock_worktree(worktree, LOCK_EX);
3135 	if (err)
3136 		goto done;
3137 
3138 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3139 	if (err)
3140 		goto done;
3141 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3142 	if (err)
3143 		goto done;
3144 
3145 	cc_arg.commitable_paths = &commitable_paths;
3146 	cc_arg.worktree = worktree;
3147 	cc_arg.repo = repo;
3148 	err = got_worktree_status(worktree, relpath ? relpath : "",
3149 	    repo, collect_commitables, &cc_arg, NULL, NULL);
3150 	if (err)
3151 		goto done;
3152 
3153 	if (TAILQ_EMPTY(&commitable_paths)) {
3154 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3155 		goto done;
3156 	}
3157 
3158 	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
3159 	if (err)
3160 		goto done;
3161 
3162 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3163 		struct got_commitable *ct = pe->data;
3164 		err = check_ct_out_of_date(ct, repo, head_commit_id);
3165 		if (err)
3166 			goto done;
3167 	}
3168 
3169 	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
3170 	if (err)
3171 		goto done;
3172 
3173 	if (commit_msg_cb != NULL) {
3174 		err = commit_msg_cb(&commitable_paths, &logmsg, commit_arg);
3175 		if (err)
3176 			goto done;
3177 	}
3178 
3179 	if (logmsg == NULL || strlen(logmsg) == 0) {
3180 		err = got_error(GOT_ERR_COMMIT_MSG_EMPTY);
3181 		goto done;
3182 	}
3183 
3184 	/* Create blobs from added and modified files and record their IDs. */
3185 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3186 		struct got_commitable *ct = pe->data;
3187 		char *ondisk_path;
3188 
3189 		if (ct->status != GOT_STATUS_ADD &&
3190 		    ct->status != GOT_STATUS_MODIFY)
3191 			continue;
3192 
3193 		if (asprintf(&ondisk_path, "%s/%s",
3194 		    worktree->root_path, pe->path) == -1) {
3195 			err = got_error_from_errno("asprintf");
3196 			goto done;
3197 		}
3198 		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
3199 		free(ondisk_path);
3200 		if (err)
3201 			goto done;
3202 	}
3203 
3204 	/* Recursively write new tree objects. */
3205 	err = write_tree(&new_tree_id, head_tree, "/", &commitable_paths,
3206 	    status_cb, status_arg, repo);
3207 	if (err)
3208 		goto done;
3209 
3210 	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
3211 	if (err)
3212 		goto done;
3213 	SIMPLEQ_INSERT_TAIL(&parent_ids, pid, entry);
3214 	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
3215 	    1, author, time(NULL), committer, time(NULL), logmsg, repo);
3216 	got_object_qid_free(pid);
3217 	if (logmsg != NULL)
3218 		free(logmsg);
3219 	if (err)
3220 		goto done;
3221 
3222 	/* Check if a concurrent commit to our branch has occurred. */
3223 	head_ref_name = got_worktree_get_head_ref_name(worktree);
3224 	if (head_ref_name == NULL) {
3225 		err = got_error_from_errno("got_worktree_get_head_ref_name");
3226 		goto done;
3227 	}
3228 	/* Lock the reference here to prevent concurrent modification. */
3229 	err = got_ref_open(&head_ref2, repo, head_ref_name, 1);
3230 	if (err)
3231 		goto done;
3232 	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
3233 	if (err)
3234 		goto done;
3235 	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
3236 		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
3237 		goto done;
3238 	}
3239 	/* Update branch head in repository. */
3240 	err = got_ref_change_ref(head_ref2, *new_commit_id);
3241 	if (err)
3242 		goto done;
3243 	err = got_ref_write(head_ref2, repo);
3244 	if (err)
3245 		goto done;
3246 
3247 	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
3248 	if (err)
3249 		goto done;
3250 
3251 	err = ref_base_commit(worktree, repo);
3252 	if (err)
3253 		goto done;
3254 
3255 	err = update_fileindex_after_commit(&commitable_paths,
3256 	    *new_commit_id, worktree);
3257 	if (err)
3258 		goto done;
3259 done:
3260 	unlockerr = lock_worktree(worktree, LOCK_SH);
3261 	if (unlockerr && err == NULL)
3262 		err = unlockerr;
3263 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3264 		struct got_commitable *ct = pe->data;
3265 		free_commitable(ct);
3266 	}
3267 	got_pathlist_free(&commitable_paths);
3268 	if (head_tree)
3269 		got_object_tree_close(head_tree);
3270 	if (head_commit)
3271 		got_object_commit_close(head_commit);
3272 	free(relpath);
3273 	free(head_commit_id);
3274 	free(head_commit_id2);
3275 	if (head_ref)
3276 		got_ref_close(head_ref);
3277 	if (head_ref2) {
3278 		unlockerr = got_ref_unlock(head_ref2);
3279 		if (unlockerr && err == NULL)
3280 			err = unlockerr;
3281 		got_ref_close(head_ref2);
3282 	}
3283 	return err;
3284 }
3285 
3286 const char *
3287 got_commitable_get_path(struct got_commitable *ct)
3288 {
3289 	return ct->path;
3290 }
3291 
3292 unsigned int
3293 got_commitable_get_status(struct got_commitable *ct)
3294 {
3295 	return ct->status;
3296 }