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     struct got_object_id *commit_id1;
1673     struct got_object_id *commit_id2;
1674     got_worktree_checkout_cb progress_cb;
1675     void *progress_arg;
1676     got_worktree_cancel_cb cancel_cb;
1677     void *cancel_arg;
1678 };
1679 
1680 static const struct got_error *
1681 merge_file_cb(void *arg, struct got_blob_object *blob1,
1682     struct got_blob_object *blob2, struct got_object_id *id1,
1683     struct got_object_id *id2, const char *path1, const char *path2,
1684     struct got_repository *repo)
1685 {
1686 	static const struct got_error *err = NULL;
1687 	struct merge_file_cb_arg *a = arg;
1688 	struct got_fileindex_entry *ie;
1689 	char *ondisk_path = NULL;
1690 	struct stat sb;
1691 	unsigned char status;
1692 	int local_changes_subsumed;
1693 
1694 	if (blob1 && blob2) {
1695 		ie = got_fileindex_entry_get(a->fileindex, path2);
1696 		if (ie == NULL) {
1697 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MISSING,
1698 			    path2);
1699 			return NULL;
1700 		}
1701 
1702 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1703 		    path2) == -1)
1704 			return got_error_from_errno("asprintf");
1705 
1706 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1707 		if (err)
1708 			goto done;
1709 
1710 		if (status == GOT_STATUS_DELETE) {
1711 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MERGE,
1712 			    path2);
1713 			goto done;
1714 		}
1715 		if (status != GOT_STATUS_NO_CHANGE &&
1716 		    status != GOT_STATUS_MODIFY &&
1717 		    status != GOT_STATUS_CONFLICT &&
1718 		    status != GOT_STATUS_ADD) {
1719 			(*a->progress_cb)(a->progress_arg, status, path2);
1720 			goto done;
1721 		}
1722 
1723 		err = merge_blob(&local_changes_subsumed, a->worktree, blob1,
1724 		    ondisk_path, path2, sb.st_mode, blob2, repo,
1725 		    a->progress_cb, a->progress_arg);
1726 	} else if (blob1) {
1727 		ie = got_fileindex_entry_get(a->fileindex, path1);
1728 		if (ie == NULL) {
1729 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_MISSING,
1730 			    path2);
1731 			return NULL;
1732 		}
1733 
1734 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1735 		    path1) == -1)
1736 			return got_error_from_errno("asprintf");
1737 
1738 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1739 		if (err)
1740 			goto done;
1741 
1742 		switch (status) {
1743 		case GOT_STATUS_NO_CHANGE:
1744 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE,
1745 			    path1);
1746 			err = remove_ondisk_file(a->worktree->root_path, path1);
1747 			if (err)
1748 				goto done;
1749 			if (ie)
1750 				got_fileindex_entry_mark_deleted_from_disk(ie);
1751 			break;
1752 		case GOT_STATUS_DELETE:
1753 		case GOT_STATUS_MISSING:
1754 			(*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE,
1755 			    path1);
1756 			if (ie)
1757 				got_fileindex_entry_mark_deleted_from_disk(ie);
1758 			break;
1759 		case GOT_STATUS_ADD:
1760 		case GOT_STATUS_MODIFY:
1761 		case GOT_STATUS_CONFLICT:
1762 			(*a->progress_cb)(a->progress_arg,
1763 			    GOT_STATUS_CANNOT_DELETE, path1);
1764 			break;
1765 		case GOT_STATUS_OBSTRUCTED:
1766 			(*a->progress_cb)(a->progress_arg, status, path1);
1767 			break;
1768 		default:
1769 			break;
1770 		}
1771 	} else if (blob2) {
1772 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1773 		    path2) == -1)
1774 			return got_error_from_errno("asprintf");
1775 		ie = got_fileindex_entry_get(a->fileindex, path2);
1776 		if (ie) {
1777 			err = get_file_status(&status, &sb, ie, ondisk_path,
1778 			    repo);
1779 			if (err)
1780 				goto done;
1781 			if (status != GOT_STATUS_NO_CHANGE &&
1782 			    status != GOT_STATUS_MODIFY &&
1783 			    status != GOT_STATUS_CONFLICT &&
1784 			    status != GOT_STATUS_ADD) {
1785 				(*a->progress_cb)(a->progress_arg, status,
1786 				    path2);
1787 				goto done;
1788 			}
1789 			err = merge_blob(&local_changes_subsumed, a->worktree,
1790 			    NULL, ondisk_path, path2, sb.st_mode, blob2, repo,
1791 			    a->progress_cb, a->progress_arg);
1792 			if (status == GOT_STATUS_DELETE) {
1793 				err = update_blob_fileindex_entry(a->worktree,
1794 				    a->fileindex, ie, ondisk_path, ie->path,
1795 				    blob2, 0);
1796 				if (err)
1797 					goto done;
1798 			}
1799 		} else {
1800 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1801 			err = install_blob(a->worktree, ondisk_path, path2,
1802 			    /* XXX get this from parent tree! */
1803 			    GOT_DEFAULT_FILE_MODE,
1804 			    sb.st_mode, blob2, 0, 0, repo,
1805 			    a->progress_cb, a->progress_arg);
1806 			if (err)
1807 				goto done;
1808 			err = got_fileindex_entry_alloc(&ie,
1809 			    ondisk_path, path2, NULL, NULL);
1810 			if (err)
1811 				goto done;
1812 			err = got_fileindex_entry_add(a->fileindex, ie);
1813 			if (err) {
1814 				got_fileindex_entry_free(ie);
1815 				goto done;
1816 			}
1817 		}
1818 	}
1819 done:
1820 	free(ondisk_path);
1821 	return err;
1822 }
1823 
1824 struct check_merge_ok_arg {
1825 	struct got_worktree *worktree;
1826 	struct got_repository *repo;
1827 };
1828 
1829 static const struct got_error *
1830 check_merge_ok(void *arg, struct got_fileindex_entry *ie)
1831 {
1832 	const struct got_error *err = NULL;
1833 	struct check_merge_ok_arg *a = arg;
1834 	unsigned char status;
1835 	struct stat sb;
1836 	char *ondisk_path;
1837 
1838 	/* Reject merges into a work tree with mixed base commits. */
1839 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
1840 	    SHA1_DIGEST_LENGTH))
1841 		return got_error(GOT_ERR_MIXED_COMMITS);
1842 
1843 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
1844 	    == -1)
1845 		return got_error_from_errno("asprintf");
1846 
1847 	/* Reject merges into a work tree with conflicted files. */
1848 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
1849 	if (err)
1850 		return err;
1851 	if (status == GOT_STATUS_CONFLICT)
1852 		return got_error(GOT_ERR_CONFLICTS);
1853 
1854 	return NULL;
1855 }
1856 
1857 const struct got_error *
1858 got_worktree_merge_files(struct got_worktree *worktree,
1859     struct got_object_id *commit_id1, struct got_object_id *commit_id2,
1860     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1861     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1862 {
1863 	const struct got_error *err = NULL, *unlockerr;
1864 	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
1865 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1866 	struct merge_file_cb_arg arg;
1867 	char *fileindex_path = NULL;
1868 	struct got_fileindex *fileindex = NULL;
1869 	struct check_merge_ok_arg mok_arg;
1870 
1871 	err = lock_worktree(worktree, LOCK_EX);
1872 	if (err)
1873 		return err;
1874 
1875 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1876 	if (err)
1877 		goto done;
1878 
1879 	mok_arg.worktree = worktree;
1880 	mok_arg.repo = repo;
1881 	err = got_fileindex_for_each_entry_safe(fileindex, check_merge_ok,
1882 	    &mok_arg);
1883 	if (err)
1884 		goto done;
1885 
1886 	err = got_object_id_by_path(&tree_id1, repo, commit_id1,
1887 	    worktree->path_prefix);
1888 	if (err)
1889 		goto done;
1890 
1891 	err = got_object_id_by_path(&tree_id2, repo, commit_id2,
1892 	    worktree->path_prefix);
1893 	if (err)
1894 		goto done;
1895 
1896 	err = got_object_open_as_tree(&tree1, repo, tree_id1);
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.commit_id1 = commit_id1;
1907 	arg.commit_id2 = commit_id2;
1908 	arg.progress_cb = progress_cb;
1909 	arg.progress_arg = progress_arg;
1910 	arg.cancel_cb = cancel_cb;
1911 	arg.cancel_arg = cancel_arg;
1912 	err = got_diff_tree(tree1, tree2, "", "", repo, merge_file_cb, &arg);
1913 	if (err)
1914 		goto done;
1915 
1916 	err = sync_fileindex(fileindex, fileindex_path);
1917 done:
1918 	got_fileindex_free(fileindex);
1919 	if (tree1)
1920 		got_object_tree_close(tree1);
1921 	if (tree2)
1922 		got_object_tree_close(tree2);
1923 
1924 	unlockerr = lock_worktree(worktree, LOCK_SH);
1925 	if (unlockerr && err == NULL)
1926 		err = unlockerr;
1927 	return err;
1928 }
1929 
1930 struct diff_dir_cb_arg {
1931     struct got_fileindex *fileindex;
1932     struct got_worktree *worktree;
1933     const char *status_path;
1934     size_t status_path_len;
1935     struct got_repository *repo;
1936     got_worktree_status_cb status_cb;
1937     void *status_arg;
1938     got_worktree_cancel_cb cancel_cb;
1939     void *cancel_arg;
1940 };
1941 
1942 static const struct got_error *
1943 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
1944     got_worktree_status_cb status_cb, void *status_arg,
1945     struct got_repository *repo)
1946 {
1947 	const struct got_error *err = NULL;
1948 	unsigned char status = GOT_STATUS_NO_CHANGE;
1949 	struct stat sb;
1950 	struct got_object_id blob_id, commit_id;
1951 
1952 	err = get_file_status(&status, &sb, ie, abspath, repo);
1953 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
1954 		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1955 		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
1956 		err = (*status_cb)(status_arg, status, ie->path, &blob_id,
1957 		    &commit_id);
1958 	}
1959 	return err;
1960 }
1961 
1962 static const struct got_error *
1963 status_old_new(void *arg, struct got_fileindex_entry *ie,
1964     struct dirent *de, const char *parent_path)
1965 {
1966 	const struct got_error *err = NULL;
1967 	struct diff_dir_cb_arg *a = arg;
1968 	char *abspath;
1969 
1970 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1971 		return got_error(GOT_ERR_CANCELLED);
1972 
1973 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
1974 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
1975 		return NULL;
1976 
1977 	if (parent_path[0]) {
1978 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
1979 		    parent_path, de->d_name) == -1)
1980 			return got_error_from_errno("asprintf");
1981 	} else {
1982 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
1983 		    de->d_name) == -1)
1984 			return got_error_from_errno("asprintf");
1985 	}
1986 
1987 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
1988 	    a->repo);
1989 	free(abspath);
1990 	return err;
1991 }
1992 
1993 static const struct got_error *
1994 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1995 {
1996 	struct diff_dir_cb_arg *a = arg;
1997 	struct got_object_id blob_id, commit_id;
1998 	unsigned char status;
1999 
2000 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2001 		return got_error(GOT_ERR_CANCELLED);
2002 
2003 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2004 		return NULL;
2005 
2006 	memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2007 	memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2008 	if (got_fileindex_entry_has_file_on_disk(ie))
2009 		status = GOT_STATUS_MISSING;
2010 	else
2011 		status = GOT_STATUS_DELETE;
2012 	return (*a->status_cb)(a->status_arg, status, ie->path, &blob_id,
2013 	    &commit_id);
2014 }
2015 
2016 static const struct got_error *
2017 status_new(void *arg, struct dirent *de, const char *parent_path)
2018 {
2019 	const struct got_error *err = NULL;
2020 	struct diff_dir_cb_arg *a = arg;
2021 	char *path = NULL;
2022 
2023 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2024 		return got_error(GOT_ERR_CANCELLED);
2025 
2026 	if (de->d_type == DT_DIR)
2027 		return NULL;
2028 
2029 	/* XXX ignore symlinks for now */
2030 	if (de->d_type == DT_LNK)
2031 		return NULL;
2032 
2033 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2034 		return NULL;
2035 
2036 	if (parent_path[0]) {
2037 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
2038 			return got_error_from_errno("asprintf");
2039 	} else {
2040 		path = de->d_name;
2041 	}
2042 
2043 	err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED, path,
2044 	    NULL, NULL);
2045 	if (parent_path[0])
2046 		free(path);
2047 	return err;
2048 }
2049 
2050 const struct got_error *
2051 got_worktree_status(struct got_worktree *worktree, const char *path,
2052     struct got_repository *repo, got_worktree_status_cb status_cb,
2053     void *status_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2054 {
2055 	const struct got_error *err = NULL;
2056 	DIR *workdir = NULL;
2057 	char *fileindex_path = NULL;
2058 	struct got_fileindex *fileindex = NULL;
2059 	FILE *index = NULL;
2060 	struct got_fileindex_diff_dir_cb fdiff_cb;
2061 	struct diff_dir_cb_arg arg;
2062 	char *ondisk_path = NULL;
2063 
2064 	fileindex = got_fileindex_alloc();
2065 	if (fileindex == NULL) {
2066 		err = got_error_from_errno("got_fileindex_alloc");
2067 		goto done;
2068 	}
2069 
2070 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
2071 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
2072 		err = got_error_from_errno("asprintf");
2073 		fileindex_path = NULL;
2074 		goto done;
2075 	}
2076 
2077 	index = fopen(fileindex_path, "rb");
2078 	if (index == NULL) {
2079 		if (errno != ENOENT) {
2080 			err = got_error_from_errno2("fopen", fileindex_path);
2081 			goto done;
2082 		}
2083 	} else {
2084 		err = got_fileindex_read(fileindex, index);
2085 		fclose(index);
2086 		if (err)
2087 			goto done;
2088 	}
2089 
2090 	if (asprintf(&ondisk_path, "%s%s%s",
2091 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
2092 		err = got_error_from_errno("asprintf");
2093 		goto done;
2094 	}
2095 	workdir = opendir(ondisk_path);
2096 	if (workdir == NULL) {
2097 		if (errno == ENOTDIR || errno == ENOENT) {
2098 			struct got_fileindex_entry *ie;
2099 			ie = got_fileindex_entry_get(fileindex, path);
2100 			if (ie == NULL) {
2101 				err = got_error(GOT_ERR_BAD_PATH);
2102 				goto done;
2103 			}
2104 			err = report_file_status(ie, ondisk_path,
2105 			    status_cb, status_arg, repo);
2106 			goto done;
2107 		} else {
2108 			err = got_error_from_errno2("opendir", ondisk_path);
2109 			goto done;
2110 		}
2111 	}
2112 	fdiff_cb.diff_old_new = status_old_new;
2113 	fdiff_cb.diff_old = status_old;
2114 	fdiff_cb.diff_new = status_new;
2115 	arg.fileindex = fileindex;
2116 	arg.worktree = worktree;
2117 	arg.status_path = path;
2118 	arg.status_path_len = strlen(path);
2119 	arg.repo = repo;
2120 	arg.status_cb = status_cb;
2121 	arg.status_arg = status_arg;
2122 	arg.cancel_cb = cancel_cb;
2123 	arg.cancel_arg = cancel_arg;
2124 	err = got_fileindex_diff_dir(fileindex, workdir, worktree->root_path,
2125 	    path, repo, &fdiff_cb, &arg);
2126 done:
2127 	if (workdir)
2128 		closedir(workdir);
2129 	free(ondisk_path);
2130 	free(fileindex_path);
2131 	got_fileindex_free(fileindex);
2132 	return err;
2133 }
2134 
2135 const struct got_error *
2136 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
2137     const char *arg)
2138 {
2139 	const struct got_error *err = NULL;
2140 	char *resolved, *path = NULL;
2141 	size_t len;
2142 
2143 	*wt_path = NULL;
2144 
2145 	resolved = realpath(arg, NULL);
2146 	if (resolved == NULL)
2147 		return got_error_from_errno2("realpath", arg);
2148 
2149 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
2150 	    strlen(got_worktree_get_root_path(worktree)))) {
2151 		err = got_error(GOT_ERR_BAD_PATH);
2152 		goto done;
2153 	}
2154 
2155 	if (strlen(resolved) > strlen(got_worktree_get_root_path(worktree))) {
2156 		err = got_path_skip_common_ancestor(&path,
2157 		    got_worktree_get_root_path(worktree), resolved);
2158 		if (err)
2159 			goto done;
2160 	} else {
2161 		path = strdup("");
2162 		if (path == NULL) {
2163 			err = got_error_from_errno("strdup");
2164 			goto done;
2165 		}
2166 	}
2167 
2168 	/* XXX status walk can't deal with trailing slash! */
2169 	len = strlen(path);
2170 	while (path[len - 1] == '/') {
2171 		path[len - 1] = '\0';
2172 		len--;
2173 	}
2174 done:
2175 	free(resolved);
2176 	if (err == NULL)
2177 		*wt_path = path;
2178 	else
2179 		free(path);
2180 	return err;
2181 }
2182 
2183 const struct got_error *
2184 got_worktree_schedule_add(struct got_worktree *worktree,
2185     struct got_pathlist_head *ondisk_paths,
2186     got_worktree_status_cb status_cb, void *status_arg,
2187     struct got_repository *repo)
2188 {
2189 	struct got_fileindex *fileindex = NULL;
2190 	char *fileindex_path = NULL;
2191 	FILE *index = NULL;
2192 	const struct got_error *err = NULL, *unlockerr = NULL;
2193 	struct got_pathlist_entry *pe;
2194 
2195 	err = lock_worktree(worktree, LOCK_EX);
2196 	if (err)
2197 		return err;
2198 
2199 
2200 	fileindex = got_fileindex_alloc();
2201 	if (fileindex == NULL) {
2202 		err = got_error_from_errno("got_fileindex_alloc");
2203 		goto done;
2204 	}
2205 
2206 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
2207 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
2208 		err = got_error_from_errno("asprintf");
2209 		fileindex_path = NULL;
2210 		goto done;
2211 	}
2212 
2213 	index = fopen(fileindex_path, "rb");
2214 	if (index == NULL) {
2215 		err = got_error_from_errno2("fopen", fileindex_path);
2216 		goto done;
2217 	}
2218 
2219 	err = got_fileindex_read(fileindex, index);
2220 	if (err)
2221 		goto done;
2222 
2223 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2224 		struct got_fileindex_entry *ie = NULL;
2225 		char *relpath;
2226 
2227 		err = got_path_skip_common_ancestor(&relpath,
2228 		    got_worktree_get_root_path(worktree), pe->path);
2229 		if (err)
2230 			goto done;
2231 
2232 		/* Re-adding an existing entry is a no-op. */
2233 		if (got_fileindex_entry_get(fileindex, relpath) != NULL)
2234 			continue;
2235 
2236 		err = got_fileindex_entry_alloc(&ie, pe->path, relpath,
2237 		    NULL, NULL);
2238 		free(relpath);
2239 		if (err)
2240 			goto done;
2241 
2242 		err = got_fileindex_entry_add(fileindex, ie);
2243 		if (err) {
2244 			got_fileindex_entry_free(ie);
2245 			goto done;
2246 		}
2247 
2248 		err = report_file_status(ie, pe->path, status_cb, status_arg,
2249 		    repo);
2250 		if (err)
2251 			goto done;
2252 	}
2253 
2254 	err = sync_fileindex(fileindex, fileindex_path);
2255 done:
2256 	if (index) {
2257 		if (fclose(index) != 0 && err == NULL)
2258 			err = got_error_from_errno("fclose");
2259 	}
2260 	if (fileindex)
2261 		got_fileindex_free(fileindex);
2262 	unlockerr = lock_worktree(worktree, LOCK_SH);
2263 	if (unlockerr && err == NULL)
2264 		err = unlockerr;
2265 	return err;
2266 }
2267 
2268 const struct got_error *
2269 got_worktree_schedule_delete(struct got_worktree *worktree,
2270     const char *ondisk_path, int delete_local_mods,
2271     got_worktree_status_cb status_cb, void *status_arg,
2272     struct got_repository *repo)
2273 {
2274 	struct got_fileindex *fileindex = NULL;
2275 	struct got_fileindex_entry *ie = NULL;
2276 	char *relpath, *fileindex_path ;
2277 	FILE *index = NULL;
2278 	const struct got_error *err = NULL, *unlockerr = NULL;
2279 	unsigned char status;
2280 	struct stat sb;
2281 
2282 	err = lock_worktree(worktree, LOCK_EX);
2283 	if (err)
2284 		return err;
2285 
2286 	err = got_path_skip_common_ancestor(&relpath,
2287 	    got_worktree_get_root_path(worktree), ondisk_path);
2288 	if (err)
2289 		goto done;
2290 
2291 	fileindex = got_fileindex_alloc();
2292 	if (fileindex == NULL) {
2293 		err = got_error_from_errno("got_fileindex_alloc");
2294 		goto done;
2295 	}
2296 
2297 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
2298 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
2299 		err = got_error_from_errno("asprintf");
2300 		fileindex_path = NULL;
2301 		goto done;
2302 	}
2303 
2304 	index = fopen(fileindex_path, "rb");
2305 	if (index == NULL) {
2306 		err = got_error_from_errno2("fopen", fileindex_path);
2307 		goto done;
2308 	}
2309 
2310 	err = got_fileindex_read(fileindex, index);
2311 	if (err)
2312 		goto done;
2313 
2314 	ie = got_fileindex_entry_get(fileindex, relpath);
2315 	if (ie == NULL) {
2316 		err = got_error(GOT_ERR_BAD_PATH);
2317 		goto done;
2318 	}
2319 
2320 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2321 	if (err)
2322 		goto done;
2323 
2324 	if (status != GOT_STATUS_NO_CHANGE) {
2325 		if (status == GOT_STATUS_DELETE) {
2326 			err = got_error_set_errno(ENOENT, ondisk_path);
2327 			goto done;
2328 		}
2329 		if (status != GOT_STATUS_MODIFY) {
2330 			err = got_error(GOT_ERR_FILE_STATUS);
2331 			goto done;
2332 		}
2333 		if (!delete_local_mods) {
2334 			err = got_error(GOT_ERR_FILE_MODIFIED);
2335 			goto done;
2336 		}
2337 	}
2338 
2339 	if (unlink(ondisk_path) != 0) {
2340 		err = got_error_from_errno2("unlink", ondisk_path);
2341 		goto done;
2342 	}
2343 
2344 	got_fileindex_entry_mark_deleted_from_disk(ie);
2345 
2346 	err = sync_fileindex(fileindex, fileindex_path);
2347 	if (err)
2348 		goto done;
2349 
2350 	err = report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2351 done:
2352 	free(relpath);
2353 	if (index) {
2354 		if (fclose(index) != 0 && err == NULL)
2355 			err = got_error_from_errno("fclose");
2356 	}
2357 	if (fileindex)
2358 		got_fileindex_free(fileindex);
2359 	unlockerr = lock_worktree(worktree, LOCK_SH);
2360 	if (unlockerr && err == NULL)
2361 		err = unlockerr;
2362 	return err;
2363 }
2364 
2365 const struct got_error *
2366 got_worktree_revert(struct got_worktree *worktree,
2367     const char *ondisk_path,
2368     got_worktree_checkout_cb progress_cb, void *progress_arg,
2369     struct got_repository *repo)
2370 {
2371 	struct got_fileindex *fileindex = NULL;
2372 	struct got_fileindex_entry *ie = NULL;
2373 	char *relpath, *fileindex_path = NULL;
2374 	char *tree_path = NULL, *parent_path, *te_name;
2375 	FILE *index = NULL;
2376 	const struct got_error *err = NULL, *unlockerr = NULL;
2377 	struct got_tree_object *tree = NULL;
2378 	struct got_object_id id, *tree_id = NULL;
2379 	const struct got_tree_entry *te;
2380 	struct got_blob_object *blob = NULL;
2381 	unsigned char status;
2382 	struct stat sb;
2383 
2384 	err = lock_worktree(worktree, LOCK_EX);
2385 	if (err)
2386 		return err;
2387 
2388 	err = got_path_skip_common_ancestor(&relpath,
2389 	    got_worktree_get_root_path(worktree), ondisk_path);
2390 	if (err)
2391 		goto done;
2392 
2393 	fileindex = got_fileindex_alloc();
2394 	if (fileindex == NULL) {
2395 		err = got_error_from_errno("got_fileindex_alloc");
2396 		goto done;
2397 	}
2398 
2399 	if (asprintf(&fileindex_path, "%s/%s/%s", worktree->root_path,
2400 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
2401 		err = got_error_from_errno("asprintf");
2402 		fileindex_path = NULL;
2403 		goto done;
2404 	}
2405 
2406 	index = fopen(fileindex_path, "rb");
2407 	if (index == NULL) {
2408 		err = got_error_from_errno2("fopen", fileindex_path);
2409 		goto done;
2410 	}
2411 
2412 	err = got_fileindex_read(fileindex, index);
2413 	if (err)
2414 		goto done;
2415 
2416 	ie = got_fileindex_entry_get(fileindex, relpath);
2417 	if (ie == NULL) {
2418 		err = got_error(GOT_ERR_BAD_PATH);
2419 		goto done;
2420 	}
2421 
2422 	/* Construct in-repository path of tree which contains this blob. */
2423 	err = got_path_dirname(&parent_path, ie->path);
2424 	if (err) {
2425 		if (err->code != GOT_ERR_BAD_PATH)
2426 			goto done;
2427 		parent_path = "/";
2428 	}
2429 	if (got_path_is_root_dir(worktree->path_prefix)) {
2430 		tree_path = strdup(parent_path);
2431 		if (tree_path == NULL) {
2432 			err = got_error_from_errno("strdup");
2433 			goto done;
2434 		}
2435 	} else {
2436 		if (got_path_is_root_dir(parent_path)) {
2437 			tree_path = strdup(worktree->path_prefix);
2438 			if (tree_path == NULL) {
2439 				err = got_error_from_errno("strdup");
2440 				goto done;
2441 			}
2442 		} else {
2443 			if (asprintf(&tree_path, "%s/%s",
2444 			    worktree->path_prefix, parent_path) == -1) {
2445 				err = got_error_from_errno("asprintf");
2446 				goto done;
2447 			}
2448 		}
2449 	}
2450 
2451 	err = got_object_id_by_path(&tree_id, repo, worktree->base_commit_id,
2452 	    tree_path);
2453 	if (err)
2454 		goto done;
2455 
2456 	err = got_object_open_as_tree(&tree, repo, tree_id);
2457 	if (err)
2458 		goto done;
2459 
2460 	te_name = basename(ie->path);
2461 	if (te_name == NULL) {
2462 		err = got_error_from_errno2("basename", ie->path);
2463 		goto done;
2464 	}
2465 
2466 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2467 	if (err)
2468 		goto done;
2469 
2470 	te = got_object_tree_find_entry(tree, te_name);
2471 	if (te == NULL && status != GOT_STATUS_ADD) {
2472 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
2473 		goto done;
2474 	}
2475 
2476 	switch (status) {
2477 	case GOT_STATUS_ADD:
2478 		(*progress_cb)(progress_arg, GOT_STATUS_REVERT, ie->path);
2479 		got_fileindex_entry_remove(fileindex, ie);
2480 		break;
2481 	case GOT_STATUS_DELETE:
2482 	case GOT_STATUS_MODIFY:
2483 	case GOT_STATUS_CONFLICT:
2484 	case GOT_STATUS_MISSING:
2485 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2486 		err = got_object_open_as_blob(&blob, repo, &id, 8192);
2487 		if (err)
2488 			goto done;
2489 		err = install_blob(worktree, ondisk_path, ie->path,
2490 		    te->mode, sb.st_mode, blob, 0, 1, repo, progress_cb,
2491 		    progress_arg);
2492 		if (err)
2493 			goto done;
2494 		if (status == GOT_STATUS_DELETE) {
2495 			err = update_blob_fileindex_entry(worktree,
2496 			    fileindex, ie, ondisk_path, ie->path, blob, 1);
2497 			if (err)
2498 				goto done;
2499 		}
2500 		break;
2501 	default:
2502 			goto done;
2503 	}
2504 
2505 	err = sync_fileindex(fileindex, fileindex_path);
2506 	if (err)
2507 		goto done;
2508 done:
2509 	free(relpath);
2510 	free(tree_path);
2511 	if (blob)
2512 		got_object_blob_close(blob);
2513 	if (tree)
2514 		got_object_tree_close(tree);
2515 	free(tree_id);
2516 	if (index) {
2517 		if (fclose(index) != 0 && err == NULL)
2518 			err = got_error_from_errno("fclose");
2519 	}
2520 	if (fileindex)
2521 		got_fileindex_free(fileindex);
2522 	unlockerr = lock_worktree(worktree, LOCK_SH);
2523 	if (unlockerr && err == NULL)
2524 		err = unlockerr;
2525 	return err;
2526 }
2527 
2528 static void
2529 free_commitable(struct got_commitable *ct)
2530 {
2531 	free(ct->path);
2532 	free(ct->in_repo_path);
2533 	free(ct->ondisk_path);
2534 	free(ct->blob_id);
2535 	free(ct->base_blob_id);
2536 	free(ct->base_commit_id);
2537 	free(ct);
2538 }
2539 
2540 struct collect_commitables_arg {
2541 	struct got_pathlist_head *commitable_paths;
2542 	struct got_repository *repo;
2543 	struct got_worktree *worktree;
2544 };
2545 
2546 static const struct got_error *
2547 collect_commitables(void *arg, unsigned char status, const char *relpath,
2548     struct got_object_id *blob_id, struct got_object_id *commit_id)
2549 {
2550 	struct collect_commitables_arg *a = arg;
2551 	const struct got_error *err = NULL;
2552 	struct got_commitable *ct = NULL;
2553 	struct got_pathlist_entry *new = NULL;
2554 	char *parent_path = NULL, *path = NULL;
2555 	struct stat sb;
2556 
2557 	if (status == GOT_STATUS_CONFLICT)
2558 		return got_error(GOT_ERR_COMMIT_CONFLICT);
2559 
2560 	if (status != GOT_STATUS_MODIFY && status != GOT_STATUS_ADD &&
2561 	    status != GOT_STATUS_DELETE)
2562 		return NULL;
2563 
2564 	if (asprintf(&path, "/%s", relpath) == -1) {
2565 		err = got_error_from_errno("asprintf");
2566 		goto done;
2567 	}
2568 	if (strcmp(path, "/") == 0) {
2569 		parent_path = strdup("");
2570 		if (parent_path == NULL)
2571 			return got_error_from_errno("strdup");
2572 	} else {
2573 		err = got_path_dirname(&parent_path, path);
2574 		if (err)
2575 			return err;
2576 	}
2577 
2578 	ct = calloc(1, sizeof(*ct));
2579 	if (ct == NULL) {
2580 		err = got_error_from_errno("calloc");
2581 		goto done;
2582 	}
2583 
2584 	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
2585 	    relpath) == -1) {
2586 		err = got_error_from_errno("asprintf");
2587 		goto done;
2588 	}
2589 	if (status == GOT_STATUS_DELETE) {
2590 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
2591 	} else {
2592 		if (lstat(ct->ondisk_path, &sb) != 0) {
2593 			err = got_error_from_errno2("lstat", ct->ondisk_path);
2594 			goto done;
2595 		}
2596 		ct->mode = sb.st_mode;
2597 	}
2598 
2599 	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
2600 	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
2601 	    relpath) == -1) {
2602 		err = got_error_from_errno("asprintf");
2603 		goto done;
2604 	}
2605 
2606 	ct->status = status;
2607 	ct->blob_id = NULL; /* will be filled in when blob gets created */
2608 	if (ct->status != GOT_STATUS_ADD) {
2609 		ct->base_blob_id = got_object_id_dup(blob_id);
2610 		if (ct->base_blob_id == NULL) {
2611 			err = got_error_from_errno("got_object_id_dup");
2612 			goto done;
2613 		}
2614 		ct->base_commit_id = got_object_id_dup(commit_id);
2615 		if (ct->base_commit_id == NULL) {
2616 			err = got_error_from_errno("got_object_id_dup");
2617 			goto done;
2618 		}
2619 	}
2620 	ct->path = strdup(path);
2621 	if (ct->path == NULL) {
2622 		err = got_error_from_errno("strdup");
2623 		goto done;
2624 	}
2625 	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
2626 done:
2627 	if (ct && (err || new == NULL))
2628 		free_commitable(ct);
2629 	free(parent_path);
2630 	free(path);
2631 	return err;
2632 }
2633 
2634 static const struct got_error *write_tree(struct got_object_id **,
2635     struct got_tree_object *, const char *, struct got_pathlist_head *,
2636     got_worktree_status_cb status_cb, void *status_arg,
2637     struct got_repository *);
2638 
2639 static const struct got_error *
2640 write_subtree(struct got_object_id **new_subtree_id,
2641     struct got_tree_entry *te, const char *parent_path,
2642     struct got_pathlist_head *commitable_paths,
2643     got_worktree_status_cb status_cb, void *status_arg,
2644     struct got_repository *repo)
2645 {
2646 	const struct got_error *err = NULL;
2647 	struct got_tree_object *subtree;
2648 	char *subpath;
2649 
2650 	if (asprintf(&subpath, "%s%s%s", parent_path,
2651 	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
2652 		return got_error_from_errno("asprintf");
2653 
2654 	err = got_object_open_as_tree(&subtree, repo, te->id);
2655 	if (err)
2656 		return err;
2657 
2658 	err = write_tree(new_subtree_id, subtree, subpath, commitable_paths,
2659 	    status_cb, status_arg, repo);
2660 	got_object_tree_close(subtree);
2661 	free(subpath);
2662 	return err;
2663 }
2664 
2665 static const struct got_error *
2666 match_ct_parent_path(int *match, struct got_commitable *ct, const char *path)
2667 {
2668 	const struct got_error *err = NULL;
2669 	char *ct_parent_path = NULL;
2670 
2671 	*match = 0;
2672 
2673 	if (strchr(ct->path, '/') == NULL) {
2674 		*match = got_path_is_root_dir(path);
2675 		return NULL;
2676 	}
2677 
2678 	err = got_path_dirname(&ct_parent_path, ct->path);
2679 	if (err)
2680 		return err;
2681 	*match = (strcmp(path, ct_parent_path) == 0);
2682 	free(ct_parent_path);
2683 	return err;
2684 }
2685 
2686 static mode_t
2687 get_ct_file_mode(struct got_commitable *ct)
2688 {
2689 	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
2690 }
2691 
2692 static const struct got_error *
2693 alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
2694     struct got_tree_entry *te, struct got_commitable *ct)
2695 {
2696 	const struct got_error *err = NULL;
2697 
2698 	*new_te = NULL;
2699 
2700 	err = got_object_tree_entry_dup(new_te, te);
2701 	if (err)
2702 		goto done;
2703 
2704 	(*new_te)->mode = get_ct_file_mode(ct);
2705 
2706 	free((*new_te)->id);
2707 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2708 	if ((*new_te)->id == NULL) {
2709 		err = got_error_from_errno("got_object_id_dup");
2710 		goto done;
2711 	}
2712 done:
2713 	if (err && *new_te) {
2714 		got_object_tree_entry_close(*new_te);
2715 		*new_te = NULL;
2716 	}
2717 	return err;
2718 }
2719 
2720 static const struct got_error *
2721 alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
2722     struct got_commitable *ct)
2723 {
2724 	const struct got_error *err = NULL;
2725 	char *ct_name;
2726 
2727 	 *new_te = NULL;
2728 
2729 	*new_te = calloc(1, sizeof(**new_te));
2730 	if (*new_te == NULL)
2731 		return got_error_from_errno("calloc");
2732 
2733 	ct_name = basename(ct->path);
2734 	if (ct_name == NULL) {
2735 		err = got_error_from_errno2("basename", ct->path);
2736 		goto done;
2737 	}
2738 	(*new_te)->name = strdup(ct_name);
2739 	if ((*new_te)->name == NULL) {
2740 		err = got_error_from_errno("strdup");
2741 		goto done;
2742 	}
2743 
2744 	(*new_te)->mode = get_ct_file_mode(ct);
2745 
2746 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2747 	if ((*new_te)->id == NULL) {
2748 		err = got_error_from_errno("got_object_id_dup");
2749 		goto done;
2750 	}
2751 done:
2752 	if (err && *new_te) {
2753 		got_object_tree_entry_close(*new_te);
2754 		*new_te = NULL;
2755 	}
2756 	return err;
2757 }
2758 
2759 static const struct got_error *
2760 insert_tree_entry(struct got_tree_entry *new_te,
2761     struct got_pathlist_head *paths)
2762 {
2763 	const struct got_error *err = NULL;
2764 	struct got_pathlist_entry *new_pe;
2765 
2766 	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
2767 	if (err)
2768 		return err;
2769 	if (new_pe == NULL)
2770 		return got_error(GOT_ERR_TREE_DUP_ENTRY);
2771 	return NULL;
2772 }
2773 
2774 static const struct got_error *
2775 report_ct_status(struct got_commitable *ct,
2776     got_worktree_status_cb status_cb, void *status_arg)
2777 {
2778 	const char *ct_path = ct->path;
2779 	while (ct_path[0] == '/')
2780 		ct_path++;
2781 	return (*status_cb)(status_arg, ct->status, ct_path, ct->blob_id, NULL);
2782 }
2783 
2784 static const struct got_error *
2785 match_modified_subtree(int *modified, struct got_tree_entry *te,
2786     const char *base_tree_path, struct got_pathlist_head *commitable_paths)
2787 {
2788 	const struct got_error *err = NULL;
2789 	struct got_pathlist_entry *pe;
2790 	char *te_path;
2791 
2792 	*modified = 0;
2793 
2794 	if (asprintf(&te_path, "%s%s%s", base_tree_path,
2795 	    got_path_is_root_dir(base_tree_path) ? "" : "/",
2796 	    te->name) == -1)
2797 		return got_error_from_errno("asprintf");
2798 
2799 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2800 		struct got_commitable *ct = pe->data;
2801 		*modified = got_path_is_child(ct->in_repo_path, te_path,
2802 		    strlen(te_path));
2803 		 if (*modified)
2804 			break;
2805 	}
2806 
2807 	free(te_path);
2808 	return err;
2809 }
2810 
2811 static const struct got_error *
2812 match_deleted_or_modified_ct(struct got_commitable **ctp,
2813     struct got_tree_entry *te, const char *base_tree_path,
2814     struct got_pathlist_head *commitable_paths)
2815 {
2816 	const struct got_error *err = NULL;
2817 	struct got_pathlist_entry *pe;
2818 
2819 	*ctp = NULL;
2820 
2821 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2822 		struct got_commitable *ct = pe->data;
2823 		char *ct_name = NULL;
2824 		int path_matches;
2825 
2826 		if (ct->status != GOT_STATUS_MODIFY &&
2827 		    ct->status != GOT_STATUS_DELETE)
2828 			continue;
2829 
2830 		if (got_object_id_cmp(ct->base_blob_id, te->id) != 0)
2831 			continue;
2832 
2833 		 err = match_ct_parent_path(&path_matches, ct, base_tree_path);
2834 		 if (err)
2835 			return err;
2836 		if (!path_matches)
2837 			continue;
2838 
2839 		ct_name = basename(pe->path);
2840 		if (ct_name == NULL)
2841 			return got_error_from_errno2("basename", pe->path);
2842 
2843 		if (strcmp(te->name, ct_name) != 0)
2844 			continue;
2845 
2846 		*ctp = ct;
2847 		break;
2848 	}
2849 
2850 	return err;
2851 }
2852 
2853 static const struct got_error *
2854 write_tree(struct got_object_id **new_tree_id,
2855     struct got_tree_object *base_tree, const char *path_base_tree,
2856     struct got_pathlist_head *commitable_paths,
2857     got_worktree_status_cb status_cb, void *status_arg,
2858     struct got_repository *repo)
2859 {
2860 	const struct got_error *err = NULL;
2861 	const struct got_tree_entries *base_entries = NULL;
2862 	struct got_pathlist_head paths;
2863 	struct got_tree_entries new_tree_entries;
2864 	struct got_tree_entry *te, *new_te = NULL;
2865 	struct got_pathlist_entry *pe;
2866 
2867 	TAILQ_INIT(&paths);
2868 	new_tree_entries.nentries = 0;
2869 	SIMPLEQ_INIT(&new_tree_entries.head);
2870 
2871 	/* Insert, and recurse into, newly added entries first. */
2872 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2873 		struct got_commitable *ct = pe->data;
2874 		char *child_path = NULL, *slash;
2875 
2876 		if (ct->status != GOT_STATUS_ADD ||
2877 		    (ct->flags & GOT_COMMITABLE_ADDED))
2878 			continue;
2879 
2880 		 if (!got_path_is_child(pe->path, path_base_tree,
2881 		     strlen(path_base_tree)))
2882 			continue;
2883 
2884 		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
2885 		    pe->path);
2886 		if (err)
2887 			goto done;
2888 
2889 		slash = strchr(child_path, '/');
2890 		if (slash == NULL) {
2891 			err = alloc_added_blob_tree_entry(&new_te, ct);
2892 			if (err)
2893 				goto done;
2894 			err = report_ct_status(ct, status_cb, status_arg);
2895 			if (err)
2896 				goto done;
2897 			ct->flags |= GOT_COMMITABLE_ADDED;
2898 		} else {
2899 			char *subtree_path;
2900 
2901 			*slash = '\0'; /* trim trailing path components */
2902 			if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
2903 			    got_path_is_root_dir(path_base_tree) ? "" : "/",
2904 			    child_path) == -1) {
2905 				err = got_error_from_errno("asprintf");
2906 				goto done;
2907 			}
2908 
2909 			new_te = calloc(1, sizeof(*new_te));
2910 			new_te->mode = S_IFDIR;
2911 			new_te->name = strdup(child_path);
2912 			if (new_te->name == NULL) {
2913 				err = got_error_from_errno("strdup");
2914 				got_object_tree_entry_close(new_te);
2915 				new_te = NULL;
2916 				goto done;
2917 			}
2918 			err = write_tree(&new_te->id, NULL, subtree_path,
2919 			    commitable_paths, status_cb, status_arg, repo);
2920 			free(subtree_path);
2921 			if (err) {
2922 				got_object_tree_entry_close(new_te);
2923 				new_te = NULL;
2924 				goto done;
2925 			}
2926 		}
2927 		err = insert_tree_entry(new_te, &paths);
2928 		if (err)
2929 			goto done;
2930 	}
2931 
2932 	if (base_tree) {
2933 		/* Handle modified and deleted entries. */
2934 		base_entries = got_object_tree_get_entries(base_tree);
2935 		SIMPLEQ_FOREACH(te, &base_entries->head, entry) {
2936 			struct got_commitable *ct = NULL;
2937 
2938 			if (S_ISDIR(te->mode)) {
2939 				int modified;
2940 				err = got_object_tree_entry_dup(&new_te, te);
2941 				if (err)
2942 					goto done;
2943 				err = match_modified_subtree(&modified, te,
2944 				    path_base_tree, commitable_paths);
2945 				if (err)
2946 					goto done;
2947 				/* Avoid recursion into unmodified subtrees. */
2948 				if (modified) {
2949 					free(new_te->id);
2950 					err = write_subtree(&new_te->id, te,
2951 					    path_base_tree, commitable_paths,
2952 					    status_cb, status_arg, repo);
2953 					if (err)
2954 						goto done;
2955 				}
2956 				err = insert_tree_entry(new_te, &paths);
2957 				if (err)
2958 					goto done;
2959 				continue;
2960 			}
2961 
2962 			err = match_deleted_or_modified_ct(&ct, te,
2963 			    path_base_tree, commitable_paths);
2964 			if (ct) {
2965 				/* NB: Deleted entries get dropped here. */
2966 				if (ct->status == GOT_STATUS_MODIFY) {
2967 					err = alloc_modified_blob_tree_entry(
2968 					    &new_te, te, ct);
2969 					if (err)
2970 						goto done;
2971 					err = insert_tree_entry(new_te, &paths);
2972 					if (err)
2973 						goto done;
2974 				}
2975 				err = report_ct_status(ct, status_cb,
2976 				    status_arg);
2977 				if (err)
2978 					goto done;
2979 			} else {
2980 				/* Entry is unchanged; just copy it. */
2981 				err = got_object_tree_entry_dup(&new_te, te);
2982 				if (err)
2983 					goto done;
2984 				err = insert_tree_entry(new_te, &paths);
2985 				if (err)
2986 					goto done;
2987 			}
2988 		}
2989 	}
2990 
2991 	/* Write new list of entries; deleted entries have been dropped. */
2992 	TAILQ_FOREACH(pe, &paths, entry) {
2993 		struct got_tree_entry *te = pe->data;
2994 		new_tree_entries.nentries++;
2995 		SIMPLEQ_INSERT_TAIL(&new_tree_entries.head, te, entry);
2996 	}
2997 	err = got_object_tree_create(new_tree_id, &new_tree_entries, repo);
2998 done:
2999 	got_object_tree_entries_close(&new_tree_entries);
3000 	got_pathlist_free(&paths);
3001 	return err;
3002 }
3003 
3004 static const struct got_error *
3005 update_fileindex_after_commit(struct got_pathlist_head *commitable_paths,
3006     struct got_object_id *new_base_commit_id, struct got_worktree *worktree)
3007 {
3008 	const struct got_error *err = NULL;
3009 	char *fileindex_path = NULL;
3010 	struct got_fileindex *fileindex = NULL;
3011 	struct got_pathlist_entry *pe;
3012 
3013 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3014 	if (err)
3015 		return err;
3016 
3017 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3018 		struct got_fileindex_entry *ie;
3019 		struct got_commitable *ct = pe->data;
3020 
3021 		ie = got_fileindex_entry_get(fileindex, pe->path);
3022 		if (ie) {
3023 			if (ct->status == GOT_STATUS_DELETE) {
3024 				got_fileindex_entry_remove(fileindex, ie);
3025 				got_fileindex_entry_free(ie);
3026 			} else
3027 				err = got_fileindex_entry_update(ie,
3028 				    ct->ondisk_path, ct->blob_id->sha1,
3029 				    new_base_commit_id->sha1, 1);
3030 		} else {
3031 			err = got_fileindex_entry_alloc(&ie,
3032 			    ct->ondisk_path, pe->path, ct->blob_id->sha1,
3033 			    new_base_commit_id->sha1);
3034 			if (err)
3035 				goto done;
3036 			err = got_fileindex_entry_add(fileindex, ie);
3037 			if (err)
3038 				goto done;
3039 		}
3040 	}
3041 
3042 	err = sync_fileindex(fileindex, fileindex_path);
3043 done:
3044 	free(fileindex_path);
3045 	got_fileindex_free(fileindex);
3046 	return err;
3047 }
3048 
3049 static const struct got_error *
3050 check_ct_out_of_date(struct got_commitable *ct, struct got_repository *repo,
3051 	struct got_object_id *head_commit_id)
3052 {
3053 	const struct got_error *err = NULL;
3054 	struct got_object_id *id_in_head;
3055 
3056 	/*
3057 	 * Require that modified/deleted files are based on the branch head.
3058 	 * This requirement could be relaxed to force less update operations
3059 	 * on users but, for now, we want to play it safe and see how it goes.
3060 	 *
3061 	 * If this check is relaxed, it must still ensure that no modifications
3062 	 * were made to files *and their parents* in commits between the file's
3063 	 * base commit and the branch head. Otherwise, tree conflicts will not
3064 	 * be detected reliably.
3065 	 */
3066 	if (ct->status != GOT_STATUS_ADD) {
3067 		if (got_object_id_cmp(ct->base_commit_id, head_commit_id) != 0)
3068 			return got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3069 		return NULL;
3070 	}
3071 
3072 	/* Require that added files don't exist in the branch head. */
3073 	err = got_object_id_by_path(&id_in_head, repo, head_commit_id,
3074 	    ct->in_repo_path);
3075 	if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
3076 		return err;
3077 	if (id_in_head) {
3078 		free(id_in_head);
3079 		return got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3080 	}
3081 
3082 	free(id_in_head);
3083 	return NULL;
3084 }
3085 
3086 const struct got_error *
3087 got_worktree_commit(struct got_object_id **new_commit_id,
3088     struct got_worktree *worktree, const char *ondisk_path,
3089     const char *author, const char *committer,
3090     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3091     got_worktree_status_cb status_cb, void *status_arg,
3092     struct got_repository *repo)
3093 {
3094 	const struct got_error *err = NULL, *unlockerr = NULL;
3095 	struct collect_commitables_arg cc_arg;
3096 	struct got_pathlist_head commitable_paths;
3097 	struct got_pathlist_entry *pe;
3098 	char *relpath = NULL;
3099 	const char *head_ref_name = NULL;
3100 	struct got_reference *head_ref = NULL;
3101 	struct got_commit_object *head_commit = NULL;
3102 	struct got_object_id *head_commit_id = NULL;
3103 	struct got_reference *head_ref2 = NULL;
3104 	struct got_object_id *head_commit_id2 = NULL;
3105 	struct got_tree_object *head_tree = NULL;
3106 	struct got_object_id *new_tree_id = NULL;
3107 	struct got_object_id_queue parent_ids;
3108 	struct got_object_qid *pid = NULL;
3109 	char *logmsg = NULL;
3110 
3111 	*new_commit_id = NULL;
3112 
3113 	TAILQ_INIT(&commitable_paths);
3114 	SIMPLEQ_INIT(&parent_ids);
3115 
3116 	if (ondisk_path) {
3117 		err = got_path_skip_common_ancestor(&relpath,
3118 		    worktree->root_path, ondisk_path);
3119 		if (err)
3120 			return err;
3121 	}
3122 
3123 	err = lock_worktree(worktree, LOCK_EX);
3124 	if (err)
3125 		goto done;
3126 
3127 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3128 	if (err)
3129 		goto done;
3130 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3131 	if (err)
3132 		goto done;
3133 
3134 	cc_arg.commitable_paths = &commitable_paths;
3135 	cc_arg.worktree = worktree;
3136 	cc_arg.repo = repo;
3137 	err = got_worktree_status(worktree, relpath ? relpath : "",
3138 	    repo, collect_commitables, &cc_arg, NULL, NULL);
3139 	if (err)
3140 		goto done;
3141 
3142 	if (TAILQ_EMPTY(&commitable_paths)) {
3143 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3144 		goto done;
3145 	}
3146 
3147 	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
3148 	if (err)
3149 		goto done;
3150 
3151 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3152 		struct got_commitable *ct = pe->data;
3153 		err = check_ct_out_of_date(ct, repo, head_commit_id);
3154 		if (err)
3155 			goto done;
3156 	}
3157 
3158 	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
3159 	if (err)
3160 		goto done;
3161 
3162 	if (commit_msg_cb != NULL) {
3163 		err = commit_msg_cb(&commitable_paths, &logmsg, commit_arg);
3164 		if (err)
3165 			goto done;
3166 	}
3167 
3168 	if (logmsg == NULL || strlen(logmsg) == 0) {
3169 		err = got_error(GOT_ERR_COMMIT_MSG_EMPTY);
3170 		goto done;
3171 	}
3172 
3173 	/* Create blobs from added and modified files and record their IDs. */
3174 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3175 		struct got_commitable *ct = pe->data;
3176 		char *ondisk_path;
3177 
3178 		if (ct->status != GOT_STATUS_ADD &&
3179 		    ct->status != GOT_STATUS_MODIFY)
3180 			continue;
3181 
3182 		if (asprintf(&ondisk_path, "%s/%s",
3183 		    worktree->root_path, pe->path) == -1) {
3184 			err = got_error_from_errno("asprintf");
3185 			goto done;
3186 		}
3187 		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
3188 		free(ondisk_path);
3189 		if (err)
3190 			goto done;
3191 	}
3192 
3193 	/* Recursively write new tree objects. */
3194 	err = write_tree(&new_tree_id, head_tree, "/", &commitable_paths,
3195 	    status_cb, status_arg, repo);
3196 	if (err)
3197 		goto done;
3198 
3199 	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
3200 	if (err)
3201 		goto done;
3202 	SIMPLEQ_INSERT_TAIL(&parent_ids, pid, entry);
3203 	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
3204 	    1, author, time(NULL), committer, time(NULL), logmsg, repo);
3205 	got_object_qid_free(pid);
3206 	if (logmsg != NULL)
3207 		free(logmsg);
3208 	if (err)
3209 		goto done;
3210 
3211 	/* Check if a concurrent commit to our branch has occurred. */
3212 	head_ref_name = got_worktree_get_head_ref_name(worktree);
3213 	if (head_ref_name == NULL) {
3214 		err = got_error_from_errno("got_worktree_get_head_ref_name");
3215 		goto done;
3216 	}
3217 	/* Lock the reference here to prevent concurrent modification. */
3218 	err = got_ref_open(&head_ref2, repo, head_ref_name, 1);
3219 	if (err)
3220 		goto done;
3221 	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
3222 	if (err)
3223 		goto done;
3224 	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
3225 		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
3226 		goto done;
3227 	}
3228 	/* Update branch head in repository. */
3229 	err = got_ref_change_ref(head_ref2, *new_commit_id);
3230 	if (err)
3231 		goto done;
3232 	err = got_ref_write(head_ref2, repo);
3233 	if (err)
3234 		goto done;
3235 
3236 	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
3237 	if (err)
3238 		goto done;
3239 
3240 	err = ref_base_commit(worktree, repo);
3241 	if (err)
3242 		goto done;
3243 
3244 	err = update_fileindex_after_commit(&commitable_paths,
3245 	    *new_commit_id, worktree);
3246 	if (err)
3247 		goto done;
3248 done:
3249 	unlockerr = lock_worktree(worktree, LOCK_SH);
3250 	if (unlockerr && err == NULL)
3251 		err = unlockerr;
3252 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3253 		struct got_commitable *ct = pe->data;
3254 		free_commitable(ct);
3255 	}
3256 	got_pathlist_free(&commitable_paths);
3257 	if (head_tree)
3258 		got_object_tree_close(head_tree);
3259 	if (head_commit)
3260 		got_object_commit_close(head_commit);
3261 	free(relpath);
3262 	free(head_commit_id);
3263 	free(head_commit_id2);
3264 	if (head_ref)
3265 		got_ref_close(head_ref);
3266 	if (head_ref2) {
3267 		unlockerr = got_ref_unlock(head_ref2);
3268 		if (unlockerr && err == NULL)
3269 			err = unlockerr;
3270 		got_ref_close(head_ref2);
3271 	}
3272 	return err;
3273 }
3274 
3275 const char *
3276 got_commitable_get_path(struct got_commitable *ct)
3277 {
3278 	return ct->path;
3279 }
3280 
3281 unsigned int
3282 got_commitable_get_status(struct got_commitable *ct)
3283 {
3284 	return ct->status;
3285 }