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 
67 	if (asprintf(&path, "%s/%s", path_got, name) == -1)
68 		return got_error_from_errno("asprintf");
69 
70 	err = got_path_create_file(path, content);
71 	free(path);
72 	return err;
73 }
74 
75 static const struct got_error *
76 update_meta_file(const char *path_got, const char *name, const char *content)
77 {
78 	const struct got_error *err = NULL;
79 	FILE *tmpfile = NULL;
80 	char *tmppath = NULL;
81 	char *path = NULL;
82 
83 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
84 		err = got_error_from_errno("asprintf");
85 		path = NULL;
86 		goto done;
87 	}
88 
89 	err = got_opentemp_named(&tmppath, &tmpfile, path);
90 	if (err)
91 		goto done;
92 
93 	if (content) {
94 		int len = fprintf(tmpfile, "%s\n", content);
95 		if (len != strlen(content) + 1) {
96 			err = got_error_from_errno2("fprintf", tmppath);
97 			goto done;
98 		}
99 	}
100 
101 	if (rename(tmppath, path) != 0) {
102 		err = got_error_from_errno3("rename", tmppath, path);
103 		unlink(tmppath);
104 		goto done;
105 	}
106 
107 done:
108 	if (fclose(tmpfile) != 0 && err == NULL)
109 		err = got_error_from_errno2("fclose", tmppath);
110 	free(tmppath);
111 	return err;
112 }
113 
114 static const struct got_error *
115 read_meta_file(char **content, const char *path_got, const char *name)
116 {
117 	const struct got_error *err = NULL;
118 	char *path;
119 	int fd = -1;
120 	ssize_t n;
121 	struct stat sb;
122 
123 	*content = NULL;
124 
125 	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
126 		err = got_error_from_errno("asprintf");
127 		path = NULL;
128 		goto done;
129 	}
130 
131 	fd = open(path, O_RDONLY | O_NOFOLLOW);
132 	if (fd == -1) {
133 		if (errno == ENOENT)
134 			err = got_error(GOT_ERR_WORKTREE_META);
135 		else
136 			err = got_error_from_errno2("open", path);
137 		goto done;
138 	}
139 	if (flock(fd, LOCK_SH | LOCK_NB) == -1) {
140 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
141 		    : got_error_from_errno2("flock", path));
142 		goto done;
143 	}
144 
145 	if (lstat(path, &sb) != 0) {
146 		err = got_error_from_errno2("lstat", path);
147 		goto done;
148 	}
149 	*content = calloc(1, sb.st_size);
150 	if (*content == NULL) {
151 		err = got_error_from_errno("calloc");
152 		goto done;
153 	}
154 
155 	n = read(fd, *content, sb.st_size);
156 	if (n != sb.st_size) {
157 		err = (n == -1 ? got_error_from_errno2("read", path) :
158 		    got_error(GOT_ERR_WORKTREE_META));
159 		goto done;
160 	}
161 	if ((*content)[sb.st_size - 1] != '\n') {
162 		err = got_error(GOT_ERR_WORKTREE_META);
163 		goto done;
164 	}
165 	(*content)[sb.st_size - 1] = '\0';
166 
167 done:
168 	if (fd != -1 && close(fd) == -1 && err == NULL)
169 		err = got_error_from_errno2("close", path_got);
170 	free(path);
171 	if (err) {
172 		free(*content);
173 		*content = NULL;
174 	}
175 	return err;
176 }
177 
178 static const struct got_error *
179 write_head_ref(const char *path_got, struct got_reference *head_ref)
180 {
181 	const struct got_error *err = NULL;
182 	char *refstr = NULL;
183 
184 	if (got_ref_is_symbolic(head_ref)) {
185 		refstr = got_ref_to_str(head_ref);
186 		if (refstr == NULL)
187 			return got_error_from_errno("got_ref_to_str");
188 	} else {
189 		refstr = strdup(got_ref_get_name(head_ref));
190 		if (refstr == NULL)
191 			return got_error_from_errno("strdup");
192 	}
193 	err = update_meta_file(path_got, GOT_WORKTREE_HEAD_REF, refstr);
194 	free(refstr);
195 	return err;
196 }
197 
198 const struct got_error *
199 got_worktree_init(const char *path, struct got_reference *head_ref,
200     const char *prefix, struct got_repository *repo)
201 {
202 	const struct got_error *err = NULL;
203 	struct got_object_id *commit_id = NULL;
204 	uuid_t uuid;
205 	uint32_t uuid_status;
206 	int obj_type;
207 	char *path_got = NULL;
208 	char *formatstr = NULL;
209 	char *absprefix = NULL;
210 	char *basestr = NULL;
211 	char *uuidstr = NULL;
212 
213 	if (strcmp(path, got_repo_get_path(repo)) == 0) {
214 		err = got_error(GOT_ERR_WORKTREE_REPO);
215 		goto done;
216 	}
217 
218 	err = got_ref_resolve(&commit_id, repo, head_ref);
219 	if (err)
220 		return err;
221 	err = got_object_get_type(&obj_type, repo, commit_id);
222 	if (err)
223 		return err;
224 	if (obj_type != GOT_OBJ_TYPE_COMMIT)
225 		return got_error(GOT_ERR_OBJ_TYPE);
226 
227 	if (!got_path_is_absolute(prefix)) {
228 		if (asprintf(&absprefix, "/%s", prefix) == -1)
229 			return got_error_from_errno("asprintf");
230 	}
231 
232 	/* Create top-level directory (may already exist). */
233 	if (mkdir(path, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
234 		err = got_error_from_errno2("mkdir", path);
235 		goto done;
236 	}
237 
238 	/* Create .got directory (may already exist). */
239 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
240 		err = got_error_from_errno("asprintf");
241 		goto done;
242 	}
243 	if (mkdir(path_got, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
244 		err = got_error_from_errno2("mkdir", path_got);
245 		goto done;
246 	}
247 
248 	/* Create an empty lock file. */
249 	err = create_meta_file(path_got, GOT_WORKTREE_LOCK, NULL);
250 	if (err)
251 		goto done;
252 
253 	/* Create an empty file index. */
254 	err = create_meta_file(path_got, GOT_WORKTREE_FILE_INDEX, NULL);
255 	if (err)
256 		goto done;
257 
258 	/* Write the HEAD reference. */
259 	err = write_head_ref(path_got, head_ref);
260 	if (err)
261 		goto done;
262 
263 	/* Record our base commit. */
264 	err = got_object_id_str(&basestr, commit_id);
265 	if (err)
266 		goto done;
267 	err = create_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, basestr);
268 	if (err)
269 		goto done;
270 
271 	/* Store path to repository. */
272 	err = create_meta_file(path_got, GOT_WORKTREE_REPOSITORY,
273 	    got_repo_get_path(repo));
274 	if (err)
275 		goto done;
276 
277 	/* Store in-repository path prefix. */
278 	err = create_meta_file(path_got, GOT_WORKTREE_PATH_PREFIX,
279 	    absprefix ? absprefix : prefix);
280 	if (err)
281 		goto done;
282 
283 	/* Generate UUID. */
284 	uuid_create(&uuid, &uuid_status);
285 	if (uuid_status != uuid_s_ok) {
286 		err = got_error_uuid(uuid_status);
287 		goto done;
288 	}
289 	uuid_to_string(&uuid, &uuidstr, &uuid_status);
290 	if (uuid_status != uuid_s_ok) {
291 		err = got_error_uuid(uuid_status);
292 		goto done;
293 	}
294 	err = create_meta_file(path_got, GOT_WORKTREE_UUID, uuidstr);
295 	if (err)
296 		goto done;
297 
298 	/* Stamp work tree with format file. */
299 	if (asprintf(&formatstr, "%d", GOT_WORKTREE_FORMAT_VERSION) == -1) {
300 		err = got_error_from_errno("asprintf");
301 		goto done;
302 	}
303 	err = create_meta_file(path_got, GOT_WORKTREE_FORMAT, formatstr);
304 	if (err)
305 		goto done;
306 
307 done:
308 	free(commit_id);
309 	free(path_got);
310 	free(formatstr);
311 	free(absprefix);
312 	free(basestr);
313 	free(uuidstr);
314 	return err;
315 }
316 
317 static const struct got_error *
318 open_worktree(struct got_worktree **worktree, const char *path)
319 {
320 	const struct got_error *err = NULL;
321 	char *path_got;
322 	char *formatstr = NULL;
323 	char *uuidstr = NULL;
324 	char *path_lock = NULL;
325 	char *base_commit_id_str = NULL;
326 	int version, fd = -1;
327 	const char *errstr;
328 	struct got_repository *repo = NULL;
329 	uint32_t uuid_status;
330 
331 	*worktree = NULL;
332 
333 	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
334 		err = got_error_from_errno("asprintf");
335 		path_got = NULL;
336 		goto done;
337 	}
338 
339 	if (asprintf(&path_lock, "%s/%s", path_got, GOT_WORKTREE_LOCK) == -1) {
340 		err = got_error_from_errno("asprintf");
341 		path_lock = NULL;
342 		goto done;
343 	}
344 
345 	fd = open(path_lock, O_RDWR | O_EXLOCK | O_NONBLOCK);
346 	if (fd == -1) {
347 		err = (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
348 		    : got_error_from_errno2("open", path_lock));
349 		goto done;
350 	}
351 
352 	err = read_meta_file(&formatstr, path_got, GOT_WORKTREE_FORMAT);
353 	if (err)
354 		goto done;
355 
356 	version = strtonum(formatstr, 1, INT_MAX, &errstr);
357 	if (errstr) {
358 		err = got_error(GOT_ERR_WORKTREE_META);
359 		goto done;
360 	}
361 	if (version != GOT_WORKTREE_FORMAT_VERSION) {
362 		err = got_error(GOT_ERR_WORKTREE_VERS);
363 		goto done;
364 	}
365 
366 	*worktree = calloc(1, sizeof(**worktree));
367 	if (*worktree == NULL) {
368 		err = got_error_from_errno("calloc");
369 		goto done;
370 	}
371 	(*worktree)->lockfd = -1;
372 
373 	(*worktree)->root_path = strdup(path);
374 	if ((*worktree)->root_path == NULL) {
375 		err = got_error_from_errno("strdup");
376 		goto done;
377 	}
378 	err = read_meta_file(&(*worktree)->repo_path, path_got,
379 	    GOT_WORKTREE_REPOSITORY);
380 	if (err)
381 		goto done;
382 
383 	err = read_meta_file(&(*worktree)->path_prefix, path_got,
384 	    GOT_WORKTREE_PATH_PREFIX);
385 	if (err)
386 		goto done;
387 
388 	err = read_meta_file(&base_commit_id_str, path_got,
389 	    GOT_WORKTREE_BASE_COMMIT);
390 	if (err)
391 		goto done;
392 
393 	err = read_meta_file(&uuidstr, path_got, GOT_WORKTREE_UUID);
394 	if (err)
395 		goto done;
396 	uuid_from_string(uuidstr, &(*worktree)->uuid, &uuid_status);
397 	if (uuid_status != uuid_s_ok) {
398 		err = got_error_uuid(uuid_status);
399 		goto done;
400 	}
401 
402 	err = got_repo_open(&repo, (*worktree)->repo_path);
403 	if (err)
404 		goto done;
405 
406 	err = got_object_resolve_id_str(&(*worktree)->base_commit_id, repo,
407 	    base_commit_id_str);
408 	if (err)
409 		goto done;
410 
411 	err = read_meta_file(&(*worktree)->head_ref_name, path_got,
412 	    GOT_WORKTREE_HEAD_REF);
413 done:
414 	if (repo)
415 		got_repo_close(repo);
416 	free(path_got);
417 	free(path_lock);
418 	free(base_commit_id_str);
419 	free(uuidstr);
420 	free(formatstr);
421 	if (err) {
422 		if (fd != -1)
423 			close(fd);
424 		if (*worktree != NULL)
425 			got_worktree_close(*worktree);
426 		*worktree = NULL;
427 	} else
428 		(*worktree)->lockfd = fd;
429 
430 	return err;
431 }
432 
433 const struct got_error *
434 got_worktree_open(struct got_worktree **worktree, const char *path)
435 {
436 	const struct got_error *err = NULL;
437 
438 	do {
439 		err = open_worktree(worktree, path);
440 		if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT))
441 			return err;
442 		if (*worktree)
443 			return NULL;
444 		path = dirname(path);
445 		if (path == NULL)
446 			return got_error_from_errno2("dirname", path);
447 	} while (!((path[0] == '.' || path[0] == '/') && path[1] == '\0'));
448 
449 	return got_error(GOT_ERR_NOT_WORKTREE);
450 }
451 
452 const struct got_error *
453 got_worktree_close(struct got_worktree *worktree)
454 {
455 	const struct got_error *err = NULL;
456 	free(worktree->root_path);
457 	free(worktree->repo_path);
458 	free(worktree->path_prefix);
459 	free(worktree->base_commit_id);
460 	free(worktree->head_ref_name);
461 	if (worktree->lockfd != -1)
462 		if (close(worktree->lockfd) != 0)
463 			err = got_error_from_errno2("close",
464 			    got_worktree_get_root_path(worktree));
465 	free(worktree);
466 	return err;
467 }
468 
469 const char *
470 got_worktree_get_root_path(struct got_worktree *worktree)
471 {
472 	return worktree->root_path;
473 }
474 
475 const char *
476 got_worktree_get_repo_path(struct got_worktree *worktree)
477 {
478 	return worktree->repo_path;
479 }
480 
481 const char *
482 got_worktree_get_path_prefix(struct got_worktree *worktree)
483 {
484 	return worktree->path_prefix;
485 }
486 
487 const struct got_error *
488 got_worktree_match_path_prefix(int *match, struct got_worktree *worktree,
489     const char *path_prefix)
490 {
491 	char *absprefix = NULL;
492 
493 	if (!got_path_is_absolute(path_prefix)) {
494 		if (asprintf(&absprefix, "/%s", path_prefix) == -1)
495 			return got_error_from_errno("asprintf");
496 	}
497 	*match = (strcmp(absprefix ? absprefix : path_prefix,
498 	    worktree->path_prefix) == 0);
499 	free(absprefix);
500 	return NULL;
501 }
502 
503 const char *
504 got_worktree_get_head_ref_name(struct got_worktree *worktree)
505 {
506 	return worktree->head_ref_name;
507 }
508 
509 const struct got_error *
510 got_worktree_set_head_ref(struct got_worktree *worktree,
511     struct got_reference *head_ref)
512 {
513 	const struct got_error *err = NULL;
514 	char *path_got = NULL, *head_ref_name = NULL;
515 
516 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
517 	    GOT_WORKTREE_GOT_DIR) == -1) {
518 		err = got_error_from_errno("asprintf");
519 		path_got = NULL;
520 		goto done;
521 	}
522 
523 	head_ref_name = strdup(got_ref_get_name(head_ref));
524 	if (head_ref_name == NULL) {
525 		err = got_error_from_errno("strdup");
526 		goto done;
527 	}
528 
529 	err = write_head_ref(path_got, head_ref);
530 	if (err)
531 		goto done;
532 
533 	free(worktree->head_ref_name);
534 	worktree->head_ref_name = head_ref_name;
535 done:
536 	free(path_got);
537 	if (err)
538 		free(head_ref_name);
539 	return err;
540 }
541 
542 struct got_object_id *
543 got_worktree_get_base_commit_id(struct got_worktree *worktree)
544 {
545 	return worktree->base_commit_id;
546 }
547 
548 const struct got_error *
549 got_worktree_set_base_commit_id(struct got_worktree *worktree,
550     struct got_repository *repo, struct got_object_id *commit_id)
551 {
552 	const struct got_error *err;
553 	struct got_object *obj = NULL;
554 	char *id_str = NULL;
555 	char *path_got = NULL;
556 
557 	if (asprintf(&path_got, "%s/%s", worktree->root_path,
558 	    GOT_WORKTREE_GOT_DIR) == -1) {
559 		err = got_error_from_errno("asprintf");
560 		path_got = NULL;
561 		goto done;
562 	}
563 
564 	err = got_object_open(&obj, repo, commit_id);
565 	if (err)
566 		return err;
567 
568 	if (obj->type != GOT_OBJ_TYPE_COMMIT) {
569 		err = got_error(GOT_ERR_OBJ_TYPE);
570 		goto done;
571 	}
572 
573 	/* Record our base commit. */
574 	err = got_object_id_str(&id_str, commit_id);
575 	if (err)
576 		goto done;
577 	err = update_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, id_str);
578 	if (err)
579 		goto done;
580 
581 	free(worktree->base_commit_id);
582 	worktree->base_commit_id = got_object_id_dup(commit_id);
583 	if (worktree->base_commit_id == NULL) {
584 		err = got_error_from_errno("got_object_id_dup");
585 		goto done;
586 	}
587 done:
588 	if (obj)
589 		got_object_close(obj);
590 	free(id_str);
591 	free(path_got);
592 	return err;
593 }
594 
595 static const struct got_error *
596 lock_worktree(struct got_worktree *worktree, int operation)
597 {
598 	if (flock(worktree->lockfd, operation | LOCK_NB) == -1)
599 		return (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
600 		    : got_error_from_errno2("flock",
601 		    got_worktree_get_root_path(worktree)));
602 	return NULL;
603 }
604 
605 static const struct got_error *
606 add_dir_on_disk(struct got_worktree *worktree, const char *path)
607 {
608 	const struct got_error *err = NULL;
609 	char *abspath;
610 
611 	if (asprintf(&abspath, "%s/%s", worktree->root_path, path) == -1)
612 		return got_error_from_errno("asprintf");
613 
614 	err = got_path_mkdir(abspath);
615 	if (err && err->code == GOT_ERR_ERRNO && errno == EEXIST) {
616 		struct stat sb;
617 		err = NULL;
618 		if (lstat(abspath, &sb) == -1) {
619 			err = got_error_from_errno2("lstat", abspath);
620 		} else if (!S_ISDIR(sb.st_mode)) {
621 			/* TODO directory is obstructed; do something */
622 			err = got_error(GOT_ERR_FILE_OBSTRUCTED);
623 		}
624 	}
625 	free(abspath);
626 	return err;
627 }
628 
629 static const struct got_error *
630 check_file_contents_equal(int *same, FILE *f1, FILE *f2)
631 {
632 	const struct got_error *err = NULL;
633 	uint8_t fbuf1[8192];
634 	uint8_t fbuf2[8192];
635 	size_t flen1 = 0, flen2 = 0;
636 
637 	*same = 1;
638 
639 	for (;;) {
640 		flen1 = fread(fbuf1, 1, sizeof(fbuf1), f1);
641 		if (flen1 == 0 && ferror(f1)) {
642 			err = got_error_from_errno("fread");
643 			break;
644 		}
645 		flen2 = fread(fbuf2, 1, sizeof(fbuf2), f2);
646 		if (flen2 == 0 && ferror(f2)) {
647 			err = got_error_from_errno("fread");
648 			break;
649 		}
650 		if (flen1 == 0) {
651 			if (flen2 != 0)
652 				*same = 0;
653 			break;
654 		} else if (flen2 == 0) {
655 			if (flen1 != 0)
656 				*same = 0;
657 			break;
658 		} else if (flen1 == flen2) {
659 			if (memcmp(fbuf1, fbuf2, flen2) != 0) {
660 				*same = 0;
661 				break;
662 			}
663 		} else {
664 			*same = 0;
665 			break;
666 		}
667 	}
668 
669 	return err;
670 }
671 
672 static const struct got_error *
673 check_files_equal(int *same, const char *f1_path, const char *f2_path)
674 {
675 	const struct got_error *err = NULL;
676 	struct stat sb;
677 	size_t size1, size2;
678 	FILE *f1 = NULL, *f2 = NULL;
679 
680 	*same = 1;
681 
682 	if (lstat(f1_path, &sb) != 0) {
683 		err = got_error_from_errno2("lstat", f1_path);
684 		goto done;
685 	}
686 	size1 = sb.st_size;
687 
688 	if (lstat(f2_path, &sb) != 0) {
689 		err = got_error_from_errno2("lstat", f2_path);
690 		goto done;
691 	}
692 	size2 = sb.st_size;
693 
694 	if (size1 != size2) {
695 		*same = 0;
696 		return NULL;
697 	}
698 
699 	f1 = fopen(f1_path, "r");
700 	if (f1 == NULL)
701 		return got_error_from_errno2("open", f1_path);
702 
703 	f2 = fopen(f2_path, "r");
704 	if (f2 == NULL) {
705 		err = got_error_from_errno2("open", f2_path);
706 		goto done;
707 	}
708 
709 	err = check_file_contents_equal(same, f1, f2);
710 done:
711 	if (f1 && fclose(f1) != 0 && err == NULL)
712 		err = got_error_from_errno("fclose");
713 	if (f2 && fclose(f2) != 0 && err == NULL)
714 		err = got_error_from_errno("fclose");
715 
716 	return err;
717 }
718 
719 /*
720  * Perform a 3-way merge where blob_orig acts as the common ancestor,
721  * blob_deriv acts as the first derived version, and the file on disk
722  * acts as the second derived version.
723  */
724 static const struct got_error *
725 merge_blob(int *local_changes_subsumed, struct got_worktree *worktree,
726     struct got_blob_object *blob_orig, const char *ondisk_path,
727     const char *path, uint16_t st_mode, struct got_blob_object *blob_deriv,
728     struct got_object_id *deriv_base_commit_id,
729     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
730     void *progress_arg)
731 {
732 	const struct got_error *err = NULL;
733 	int merged_fd = -1;
734 	FILE *f_deriv = NULL, *f_orig = NULL;
735 	char *blob_deriv_path = NULL, *blob_orig_path = NULL;
736 	char *merged_path = NULL, *base_path = NULL;
737 	char *id_str = NULL;
738 	char *label_deriv = NULL;
739 	int overlapcnt = 0;
740 	char *parent;
741 
742 	*local_changes_subsumed = 0;
743 
744 	parent = dirname(ondisk_path);
745 	if (parent == NULL)
746 		return got_error_from_errno2("dirname", ondisk_path);
747 
748 	if (asprintf(&base_path, "%s/got-merged", parent) == -1)
749 		return got_error_from_errno("asprintf");
750 
751 	err = got_opentemp_named_fd(&merged_path, &merged_fd, base_path);
752 	if (err)
753 		goto done;
754 
755 	free(base_path);
756 	if (asprintf(&base_path, "%s/got-merge-blob-deriv", parent) == -1) {
757 		err = got_error_from_errno("asprintf");
758 		base_path = NULL;
759 		goto done;
760 	}
761 
762 	err = got_opentemp_named(&blob_deriv_path, &f_deriv, base_path);
763 	if (err)
764 		goto done;
765 	err = got_object_blob_dump_to_file(NULL, NULL, NULL, f_deriv,
766 	    blob_deriv);
767 	if (err)
768 		goto done;
769 
770 	free(base_path);
771 	if (asprintf(&base_path, "%s/got-merge-blob-orig", parent) == -1) {
772 		err = got_error_from_errno("asprintf");
773 		base_path = NULL;
774 		goto done;
775 	}
776 
777 	err = got_opentemp_named(&blob_orig_path, &f_orig, base_path);
778 	if (err)
779 		goto done;
780 	if (blob_orig) {
781 		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f_orig,
782 		    blob_orig);
783 		if (err)
784 			goto done;
785 	} else {
786 		/*
787 		 * If the file has no blob, this is an "add vs add" conflict,
788 		 * and we simply use an empty ancestor file to make both files
789 		 * appear in the merged result in their entirety.
790 		 */
791 	}
792 
793 	err = got_object_id_str(&id_str, deriv_base_commit_id);
794 	if (err)
795 		goto done;
796 	if (asprintf(&label_deriv, "commit %s", id_str) == -1) {
797 		err = got_error_from_errno("asprintf");
798 		goto done;
799 	}
800 
801 	err = got_merge_diff3(&overlapcnt, merged_fd, blob_deriv_path,
802 	    blob_orig_path, ondisk_path, label_deriv, path);
803 	if (err)
804 		goto done;
805 
806 	err = (*progress_cb)(progress_arg,
807 	    overlapcnt > 0 ? GOT_STATUS_CONFLICT : GOT_STATUS_MERGE, path);
808 	if (err)
809 		goto done;
810 
811 	if (fsync(merged_fd) != 0) {
812 		err = got_error_from_errno("fsync");
813 		goto done;
814 	}
815 
816 	/* Check if a clean merge has subsumed all local changes. */
817 	if (overlapcnt == 0) {
818 		err = check_files_equal(local_changes_subsumed, blob_deriv_path,
819 		    merged_path);
820 		if (err)
821 			goto done;
822 	}
823 
824 	if (chmod(merged_path, st_mode) != 0) {
825 		err = got_error_from_errno2("chmod", merged_path);
826 		goto done;
827 	}
828 
829 	if (rename(merged_path, ondisk_path) != 0) {
830 		err = got_error_from_errno3("rename", merged_path,
831 		    ondisk_path);
832 		unlink(merged_path);
833 		goto done;
834 	}
835 
836 done:
837 	if (merged_fd != -1 && close(merged_fd) != 0 && err == NULL)
838 		err = got_error_from_errno("close");
839 	if (f_deriv && fclose(f_deriv) != 0 && err == NULL)
840 		err = got_error_from_errno("fclose");
841 	if (f_orig && fclose(f_orig) != 0 && err == NULL)
842 		err = got_error_from_errno("fclose");
843 	free(merged_path);
844 	free(base_path);
845 	if (blob_deriv_path) {
846 		unlink(blob_deriv_path);
847 		free(blob_deriv_path);
848 	}
849 	if (blob_orig_path) {
850 		unlink(blob_orig_path);
851 		free(blob_orig_path);
852 	}
853 	free(id_str);
854 	free(label_deriv);
855 	return err;
856 }
857 
858 static const struct got_error *
859 update_blob_fileindex_entry(struct got_worktree *worktree,
860     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
861     const char *ondisk_path, const char *path, struct got_blob_object *blob,
862     int update_timestamps)
863 {
864 	const struct got_error *err = NULL;
865 
866 	if (ie == NULL)
867 		ie = got_fileindex_entry_get(fileindex, path);
868 	if (ie)
869 		err = got_fileindex_entry_update(ie, ondisk_path,
870 		    blob->id.sha1, worktree->base_commit_id->sha1,
871 		    update_timestamps);
872 	else {
873 		struct got_fileindex_entry *new_ie;
874 		err = got_fileindex_entry_alloc(&new_ie, ondisk_path,
875 		    path, blob->id.sha1, worktree->base_commit_id->sha1);
876 		if (!err)
877 			err = got_fileindex_entry_add(fileindex, new_ie);
878 	}
879 	return err;
880 }
881 
882 static const struct got_error *
883 install_blob(struct got_worktree *worktree, const char *ondisk_path,
884    const char *path, uint16_t te_mode, uint16_t st_mode,
885    struct got_blob_object *blob, int restoring_missing_file,
886    int reverting_versioned_file, struct got_repository *repo,
887    got_worktree_checkout_cb progress_cb, void *progress_arg)
888 {
889 	const struct got_error *err = NULL;
890 	int fd = -1;
891 	size_t len, hdrlen;
892 	int update = 0;
893 	char *tmppath = NULL;
894 
895 	fd = open(ondisk_path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
896 	    GOT_DEFAULT_FILE_MODE);
897 	if (fd == -1) {
898 		if (errno == ENOENT) {
899 			char *parent = dirname(path);
900 			if (parent == NULL)
901 				return got_error_from_errno2("dirname", path);
902 			err = add_dir_on_disk(worktree, parent);
903 			if (err)
904 				return err;
905 			fd = open(ondisk_path,
906 			    O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
907 			    GOT_DEFAULT_FILE_MODE);
908 			if (fd == -1)
909 				return got_error_from_errno2("open",
910 				    ondisk_path);
911 		} else if (errno == EEXIST) {
912 			if (!S_ISREG(st_mode)) {
913 				/* TODO file is obstructed; do something */
914 				err = got_error(GOT_ERR_FILE_OBSTRUCTED);
915 				goto done;
916 			} else {
917 				err = got_opentemp_named_fd(&tmppath, &fd,
918 				    ondisk_path);
919 				if (err)
920 					goto done;
921 				update = 1;
922 			}
923 		} else
924 			return got_error_from_errno2("open", ondisk_path);
925 	}
926 
927 	if (restoring_missing_file)
928 		err = (*progress_cb)(progress_arg, GOT_STATUS_MISSING, path);
929 	else if (reverting_versioned_file)
930 		err = (*progress_cb)(progress_arg, GOT_STATUS_REVERT, path);
931 	else
932 		err = (*progress_cb)(progress_arg,
933 		    update ? GOT_STATUS_UPDATE : GOT_STATUS_ADD, path);
934 	if (err)
935 		goto done;
936 
937 	hdrlen = got_object_blob_get_hdrlen(blob);
938 	do {
939 		const uint8_t *buf = got_object_blob_get_read_buf(blob);
940 		err = got_object_blob_read_block(&len, blob);
941 		if (err)
942 			break;
943 		if (len > 0) {
944 			/* Skip blob object header first time around. */
945 			ssize_t outlen = write(fd, buf + hdrlen, len - hdrlen);
946 			if (outlen == -1) {
947 				err = got_error_from_errno("write");
948 				goto done;
949 			} else if (outlen != len - hdrlen) {
950 				err = got_error(GOT_ERR_IO);
951 				goto done;
952 			}
953 			hdrlen = 0;
954 		}
955 	} while (len != 0);
956 
957 	if (fsync(fd) != 0) {
958 		err = got_error_from_errno("fsync");
959 		goto done;
960 	}
961 
962 	if (update) {
963 		if (rename(tmppath, ondisk_path) != 0) {
964 			err = got_error_from_errno3("rename", tmppath,
965 			    ondisk_path);
966 			unlink(tmppath);
967 			goto done;
968 		}
969 	}
970 
971 	if (te_mode & S_IXUSR) {
972 		if (chmod(ondisk_path, st_mode | S_IXUSR) == -1) {
973 			err = got_error_from_errno2("chmod", ondisk_path);
974 			goto done;
975 		}
976 	} else {
977 		if (chmod(ondisk_path, st_mode & ~S_IXUSR) == -1) {
978 			err = got_error_from_errno2("chmod", ondisk_path);
979 			goto done;
980 		}
981 	}
982 
983 done:
984 	if (fd != -1 && close(fd) != 0 && err == NULL)
985 		err = got_error_from_errno("close");
986 	free(tmppath);
987 	return err;
988 }
989 
990 /* Upgrade STATUS_MODIFY to STATUS_CONFLICT if a conflict marker is found. */
991 static const struct got_error *
992 get_modified_file_content_status(unsigned char *status, FILE *f)
993 {
994 	const struct got_error *err = NULL;
995 	const char *markers[3] = {
996 		GOT_DIFF_CONFLICT_MARKER_BEGIN,
997 		GOT_DIFF_CONFLICT_MARKER_SEP,
998 		GOT_DIFF_CONFLICT_MARKER_END
999 	};
1000 	int i = 0;
1001 	char *line;
1002 	size_t len;
1003 	const char delim[3] = {'\0', '\0', '\0'};
1004 
1005 	while (*status == GOT_STATUS_MODIFY) {
1006 		line = fparseln(f, &len, NULL, delim, 0);
1007 		if (line == NULL) {
1008 			if (feof(f))
1009 				break;
1010 			err = got_ferror(f, GOT_ERR_IO);
1011 			break;
1012 		}
1013 
1014 		if (strncmp(line, markers[i], strlen(markers[i])) == 0) {
1015 			if (strcmp(markers[i], GOT_DIFF_CONFLICT_MARKER_END)
1016 			    == 0)
1017 				*status = GOT_STATUS_CONFLICT;
1018 			else
1019 				i++;
1020 		}
1021 	}
1022 
1023 	return err;
1024 }
1025 
1026 static int
1027 stat_info_differs(struct got_fileindex_entry *ie, struct stat *sb)
1028 {
1029 	return !(ie->ctime_sec == sb->st_ctime &&
1030 	    ie->ctime_nsec == sb->st_ctimensec &&
1031 	    ie->mtime_sec == sb->st_mtime &&
1032 	    ie->mtime_nsec == sb->st_mtimensec &&
1033 	    ie->size == (sb->st_size & 0xffffffff));
1034 }
1035 
1036 static const struct got_error *
1037 get_file_status(unsigned char *status, struct stat *sb,
1038     struct got_fileindex_entry *ie, const char *abspath,
1039     struct got_repository *repo)
1040 {
1041 	const struct got_error *err = NULL;
1042 	struct got_object_id id;
1043 	size_t hdrlen;
1044 	FILE *f = NULL;
1045 	uint8_t fbuf[8192];
1046 	struct got_blob_object *blob = NULL;
1047 	size_t flen, blen;
1048 
1049 	*status = GOT_STATUS_NO_CHANGE;
1050 
1051 	if (lstat(abspath, sb) == -1) {
1052 		if (errno == ENOENT) {
1053 			if (ie) {
1054 				if (got_fileindex_entry_has_file_on_disk(ie))
1055 					*status = GOT_STATUS_MISSING;
1056 				else
1057 					*status = GOT_STATUS_DELETE;
1058 				sb->st_mode =
1059 				    ((ie->mode >> GOT_FILEIDX_MODE_PERMS_SHIFT)
1060 				    & (S_IRWXU | S_IRWXG | S_IRWXO));
1061 			} else
1062 				sb->st_mode = GOT_DEFAULT_FILE_MODE;
1063 			return NULL;
1064 		}
1065 		return got_error_from_errno2("lstat", abspath);
1066 	}
1067 
1068 	if (!S_ISREG(sb->st_mode)) {
1069 		*status = GOT_STATUS_OBSTRUCTED;
1070 		return NULL;
1071 	}
1072 
1073 	if (ie == NULL)
1074 		return NULL;
1075 
1076 	if (!got_fileindex_entry_has_file_on_disk(ie)) {
1077 		*status = GOT_STATUS_DELETE;
1078 		return NULL;
1079 	} else if (!got_fileindex_entry_has_blob(ie)) {
1080 		*status = GOT_STATUS_ADD;
1081 		return NULL;
1082 	}
1083 
1084 	if (!stat_info_differs(ie, sb))
1085 		return NULL;
1086 
1087 	memcpy(id.sha1, ie->blob_sha1, sizeof(id.sha1));
1088 	err = got_object_open_as_blob(&blob, repo, &id, sizeof(fbuf));
1089 	if (err)
1090 		return err;
1091 
1092 	f = fopen(abspath, "r");
1093 	if (f == NULL) {
1094 		err = got_error_from_errno2("fopen", abspath);
1095 		goto done;
1096 	}
1097 	hdrlen = got_object_blob_get_hdrlen(blob);
1098 	for (;;) {
1099 		const uint8_t *bbuf = got_object_blob_get_read_buf(blob);
1100 		err = got_object_blob_read_block(&blen, blob);
1101 		if (err)
1102 			goto done;
1103 		/* Skip length of blob object header first time around. */
1104 		flen = fread(fbuf, 1, sizeof(fbuf) - hdrlen, f);
1105 		if (flen == 0 && ferror(f)) {
1106 			err = got_error_from_errno("fread");
1107 			goto done;
1108 		}
1109 		if (blen == 0) {
1110 			if (flen != 0)
1111 				*status = GOT_STATUS_MODIFY;
1112 			break;
1113 		} else if (flen == 0) {
1114 			if (blen != 0)
1115 				*status = GOT_STATUS_MODIFY;
1116 			break;
1117 		} else if (blen - hdrlen == flen) {
1118 			/* Skip blob object header first time around. */
1119 			if (memcmp(bbuf + hdrlen, fbuf, flen) != 0) {
1120 				*status = GOT_STATUS_MODIFY;
1121 				break;
1122 			}
1123 		} else {
1124 			*status = GOT_STATUS_MODIFY;
1125 			break;
1126 		}
1127 		hdrlen = 0;
1128 	}
1129 
1130 	if (*status == GOT_STATUS_MODIFY) {
1131 		rewind(f);
1132 		err = get_modified_file_content_status(status, f);
1133 	}
1134 done:
1135 	if (blob)
1136 		got_object_blob_close(blob);
1137 	if (f)
1138 		fclose(f);
1139 	return err;
1140 }
1141 
1142 /*
1143  * Update timestamps in the file index if a file is unmodified and
1144  * we had to run a full content comparison to find out.
1145  */
1146 static const struct got_error *
1147 sync_timestamps(char *ondisk_path, unsigned char status,
1148     struct got_fileindex_entry *ie, struct stat *sb)
1149 {
1150 	if (status == GOT_STATUS_NO_CHANGE && stat_info_differs(ie, sb))
1151 		return got_fileindex_entry_update(ie, ondisk_path,
1152 		    ie->blob_sha1, ie->commit_sha1, 1);
1153 
1154 	return NULL;
1155 }
1156 
1157 static const struct got_error *
1158 update_blob(struct got_worktree *worktree,
1159     struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
1160     struct got_tree_entry *te, const char *path,
1161     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1162     void *progress_arg)
1163 {
1164 	const struct got_error *err = NULL;
1165 	struct got_blob_object *blob = NULL;
1166 	char *ondisk_path;
1167 	unsigned char status = GOT_STATUS_NO_CHANGE;
1168 	struct stat sb;
1169 
1170 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
1171 		return got_error_from_errno("asprintf");
1172 
1173 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1174 	if (err)
1175 		goto done;
1176 
1177 	if (status == GOT_STATUS_OBSTRUCTED) {
1178 		err = (*progress_cb)(progress_arg, status, path);
1179 		goto done;
1180 	}
1181 
1182 	if (ie && status != GOT_STATUS_MISSING) {
1183 		if (got_fileindex_entry_has_commit(ie) &&
1184 		    memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
1185 		    SHA1_DIGEST_LENGTH) == 0) {
1186 			err = sync_timestamps(ondisk_path, status, ie, &sb);
1187 			if (err)
1188 				goto done;
1189 			err = (*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
1190 			    path);
1191 			goto done;
1192 		}
1193 		if (got_fileindex_entry_has_blob(ie) &&
1194 		    memcmp(ie->blob_sha1, te->id->sha1,
1195 		    SHA1_DIGEST_LENGTH) == 0) {
1196 			err = sync_timestamps(ondisk_path, status, ie, &sb);
1197 			goto done;
1198 		}
1199 	}
1200 
1201 	err = got_object_open_as_blob(&blob, repo, te->id, 8192);
1202 	if (err)
1203 		goto done;
1204 
1205 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_ADD) {
1206 		int update_timestamps;
1207 		struct got_blob_object *blob2 = NULL;
1208 		if (got_fileindex_entry_has_blob(ie)) {
1209 			struct got_object_id id2;
1210 			memcpy(id2.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
1211 			err = got_object_open_as_blob(&blob2, repo, &id2, 8192);
1212 			if (err)
1213 				goto done;
1214 		}
1215 		err = merge_blob(&update_timestamps, worktree, blob2,
1216 		    ondisk_path, path, sb.st_mode, blob,
1217 		    worktree->base_commit_id, repo,
1218 		    progress_cb, progress_arg);
1219 		if (blob2)
1220 			got_object_blob_close(blob2);
1221 		/*
1222 		 * Do not update timestamps of files with local changes.
1223 		 * Otherwise, a future status walk would treat them as
1224 		 * unmodified files again.
1225 		 */
1226 		err = got_fileindex_entry_update(ie, ondisk_path,
1227 		    blob->id.sha1, worktree->base_commit_id->sha1,
1228 		    update_timestamps);
1229 	} else if (status == GOT_STATUS_DELETE) {
1230 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, path);
1231 		if (err)
1232 			goto done;
1233 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1234 		    ondisk_path, path, blob, 0);
1235 		if (err)
1236 			goto done;
1237 	} else {
1238 		err = install_blob(worktree, ondisk_path, path, te->mode,
1239 		    sb.st_mode, blob, status == GOT_STATUS_MISSING, 0,
1240 		    repo, progress_cb, progress_arg);
1241 		if (err)
1242 			goto done;
1243 		err = update_blob_fileindex_entry(worktree, fileindex, ie,
1244 		    ondisk_path, path, blob, 1);
1245 		if (err)
1246 			goto done;
1247 	}
1248 	got_object_blob_close(blob);
1249 done:
1250 	free(ondisk_path);
1251 	return err;
1252 }
1253 
1254 static const struct got_error *
1255 remove_ondisk_file(const char *root_path, const char *path)
1256 {
1257 	const struct got_error *err = NULL;
1258 	char *ondisk_path = NULL;
1259 
1260 	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
1261 		return got_error_from_errno("asprintf");
1262 
1263 	if (unlink(ondisk_path) == -1) {
1264 		if (errno != ENOENT)
1265 			err = got_error_from_errno2("unlink", ondisk_path);
1266 	} else {
1267 		char *parent = dirname(ondisk_path);
1268 		while (parent && strcmp(parent, root_path) != 0) {
1269 			if (rmdir(parent) == -1) {
1270 				if (errno != ENOTEMPTY)
1271 					err = got_error_from_errno2("rmdir",
1272 					    parent);
1273 				break;
1274 			}
1275 			parent = dirname(parent);
1276 		}
1277 	}
1278 	free(ondisk_path);
1279 	return err;
1280 }
1281 
1282 static const struct got_error *
1283 delete_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
1284     struct got_fileindex_entry *ie, struct got_repository *repo,
1285     got_worktree_checkout_cb progress_cb, void *progress_arg)
1286 {
1287 	const struct got_error *err = NULL;
1288 	unsigned char status;
1289 	struct stat sb;
1290 	char *ondisk_path;
1291 
1292 	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, ie->path)
1293 	    == -1)
1294 		return got_error_from_errno("asprintf");
1295 
1296 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1297 	if (err)
1298 		return err;
1299 
1300 	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_CONFLICT ||
1301 	    status == GOT_STATUS_ADD) {
1302 		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, ie->path);
1303 		if (err)
1304 			return err;
1305 		/*
1306 		 * Preserve the working file and change the deleted blob's
1307 		 * entry into a schedule-add entry.
1308 		 */
1309 		err = got_fileindex_entry_update(ie, ondisk_path, NULL, NULL,
1310 		    0);
1311 		if (err)
1312 			return err;
1313 	} else {
1314 		err = (*progress_cb)(progress_arg, GOT_STATUS_DELETE, ie->path);
1315 		if (err)
1316 			return err;
1317 		if (status == GOT_STATUS_NO_CHANGE) {
1318 			err = remove_ondisk_file(worktree->root_path, ie->path);
1319 			if (err)
1320 				return err;
1321 		}
1322 		got_fileindex_entry_remove(fileindex, ie);
1323 	}
1324 
1325 	return err;
1326 }
1327 
1328 struct diff_cb_arg {
1329     struct got_fileindex *fileindex;
1330     struct got_worktree *worktree;
1331     struct got_repository *repo;
1332     got_worktree_checkout_cb progress_cb;
1333     void *progress_arg;
1334     got_worktree_cancel_cb cancel_cb;
1335     void *cancel_arg;
1336 };
1337 
1338 static const struct got_error *
1339 diff_old_new(void *arg, struct got_fileindex_entry *ie,
1340     struct got_tree_entry *te, const char *parent_path)
1341 {
1342 	struct diff_cb_arg *a = arg;
1343 
1344 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1345 		return got_error(GOT_ERR_CANCELLED);
1346 
1347 	return update_blob(a->worktree, a->fileindex, ie, te,
1348 	    ie->path, a->repo, a->progress_cb, a->progress_arg);
1349 }
1350 
1351 static const struct got_error *
1352 diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
1353 {
1354 	struct diff_cb_arg *a = arg;
1355 
1356 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1357 		return got_error(GOT_ERR_CANCELLED);
1358 
1359 	return delete_blob(a->worktree, a->fileindex, ie,
1360 	    a->repo, a->progress_cb, a->progress_arg);
1361 }
1362 
1363 static const struct got_error *
1364 diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
1365 {
1366 	struct diff_cb_arg *a = arg;
1367 	const struct got_error *err;
1368 	char *path;
1369 
1370 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
1371 		return got_error(GOT_ERR_CANCELLED);
1372 
1373 	if (asprintf(&path, "%s%s%s", parent_path,
1374 	    parent_path[0] ? "/" : "", te->name)
1375 	    == -1)
1376 		return got_error_from_errno("asprintf");
1377 
1378 	if (S_ISDIR(te->mode))
1379 		err = add_dir_on_disk(a->worktree, path);
1380 	else
1381 		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
1382 		    a->repo, a->progress_cb, a->progress_arg);
1383 
1384 	free(path);
1385 	return err;
1386 }
1387 
1388 static const struct got_error *
1389 get_ref_name(char **refname, struct got_worktree *worktree, const char *prefix)
1390 {
1391 	const struct got_error *err = NULL;
1392 	char *uuidstr = NULL;
1393 	uint32_t uuid_status;
1394 
1395 	*refname = NULL;
1396 
1397 	uuid_to_string(&worktree->uuid, &uuidstr, &uuid_status);
1398 	if (uuid_status != uuid_s_ok)
1399 		return got_error_uuid(uuid_status);
1400 
1401 	if (asprintf(refname, "%s-%s", prefix, uuidstr)
1402 	    == -1) {
1403 		err = got_error_from_errno("asprintf");
1404 		*refname = NULL;
1405 	}
1406 	free(uuidstr);
1407 	return err;
1408 }
1409 
1410 const struct got_error *
1411 got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
1412 {
1413 	return get_ref_name(refname, worktree, GOT_WORKTREE_BASE_REF_PREFIX);
1414 }
1415 
1416 static const struct got_error *
1417 get_rebase_tmp_ref_name(char **refname, struct got_worktree *worktree)
1418 {
1419 	return get_ref_name(refname, worktree,
1420 	    GOT_WORKTREE_REBASE_TMP_REF_PREFIX);
1421 }
1422 
1423 static const struct got_error *
1424 get_newbase_symref_name(char **refname, struct got_worktree *worktree)
1425 {
1426 	return get_ref_name(refname, worktree, GOT_WORKTREE_NEWBASE_REF_PREFIX);
1427 }
1428 
1429 static const struct got_error *
1430 get_rebase_branch_symref_name(char **refname, struct got_worktree *worktree)
1431 {
1432 	return get_ref_name(refname, worktree,
1433 	    GOT_WORKTREE_REBASE_BRANCH_REF_PREFIX);
1434 }
1435 
1436 static const struct got_error *
1437 get_rebase_commit_ref_name(char **refname, struct got_worktree *worktree)
1438 {
1439 	return get_ref_name(refname, worktree,
1440 	    GOT_WORKTREE_REBASE_COMMIT_REF_PREFIX);
1441 }
1442 
1443 
1444 /*
1445  * Prevent Git's garbage collector from deleting our base commit by
1446  * setting a reference to our base commit's ID.
1447  */
1448 static const struct got_error *
1449 ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
1450 {
1451 	const struct got_error *err = NULL;
1452 	struct got_reference *ref = NULL;
1453 	char *refname;
1454 
1455 	err = got_worktree_get_base_ref_name(&refname, worktree);
1456 	if (err)
1457 		return err;
1458 
1459 	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
1460 	if (err)
1461 		goto done;
1462 
1463 	err = got_ref_write(ref, repo);
1464 done:
1465 	free(refname);
1466 	if (ref)
1467 		got_ref_close(ref);
1468 	return err;
1469 }
1470 
1471 static const struct got_error *
1472 open_fileindex(struct got_fileindex **fileindex, char **fileindex_path,
1473    struct got_worktree *worktree)
1474 {
1475 	const struct got_error *err = NULL;
1476 	FILE *index = NULL;
1477 
1478 	*fileindex_path = NULL;
1479 	*fileindex = got_fileindex_alloc();
1480 	if (*fileindex == NULL)
1481 		return got_error_from_errno("got_fileindex_alloc");
1482 
1483 	if (asprintf(fileindex_path, "%s/%s/%s", worktree->root_path,
1484 	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
1485 		err = got_error_from_errno("asprintf");
1486 		*fileindex_path = NULL;
1487 		goto done;
1488 	}
1489 
1490 	index = fopen(*fileindex_path, "rb");
1491 	if (index == NULL) {
1492 		if (errno != ENOENT)
1493 			err = got_error_from_errno2("fopen", *fileindex_path);
1494 	} else {
1495 		err = got_fileindex_read(*fileindex, index);
1496 		if (fclose(index) != 0 && err == NULL)
1497 			err = got_error_from_errno("fclose");
1498 	}
1499 done:
1500 	if (err) {
1501 		free(*fileindex_path);
1502 		*fileindex_path = NULL;
1503 		got_fileindex_free(*fileindex);
1504 		*fileindex = NULL;
1505 	}
1506 	return err;
1507 }
1508 
1509 struct bump_base_commit_id_arg {
1510 	struct got_object_id *base_commit_id;
1511 	const char *path;
1512 	size_t path_len;
1513 	const char *entry_name;
1514 	got_worktree_checkout_cb progress_cb;
1515 	void *progress_arg;
1516 };
1517 
1518 /* Bump base commit ID of all files within an updated part of the work tree. */
1519 static const struct got_error *
1520 bump_base_commit_id(void *arg, struct got_fileindex_entry *ie)
1521 {
1522 	const struct got_error *err;
1523 	struct bump_base_commit_id_arg *a = arg;
1524 
1525 	if (a->entry_name) {
1526 		if (strcmp(ie->path, a->path) != 0)
1527 			return NULL;
1528 	} else if (!got_path_is_child(ie->path, a->path, a->path_len))
1529 		return NULL;
1530 
1531 	if (memcmp(ie->commit_sha1, a->base_commit_id->sha1,
1532 	    SHA1_DIGEST_LENGTH) == 0)
1533 		return NULL;
1534 
1535 	if (a->progress_cb) {
1536 		err = (*a->progress_cb)(a->progress_arg, GOT_STATUS_BUMP_BASE,
1537 		    ie->path);
1538 		if (err)
1539 			return err;
1540 	}
1541 	memcpy(ie->commit_sha1, a->base_commit_id->sha1, SHA1_DIGEST_LENGTH);
1542 	return NULL;
1543 }
1544 
1545 static const struct got_error *
1546 sync_fileindex(struct got_fileindex *fileindex, const char *fileindex_path)
1547 {
1548 	const struct got_error *err = NULL;
1549 	char *new_fileindex_path = NULL;
1550 	FILE *new_index = NULL;
1551 
1552 	err = got_opentemp_named(&new_fileindex_path, &new_index,
1553 	    fileindex_path);
1554 	if (err)
1555 		goto done;
1556 
1557 	err = got_fileindex_write(fileindex, new_index);
1558 	if (err)
1559 		goto done;
1560 
1561 	if (rename(new_fileindex_path, fileindex_path) != 0) {
1562 		err = got_error_from_errno3("rename", new_fileindex_path,
1563 		    fileindex_path);
1564 		unlink(new_fileindex_path);
1565 	}
1566 done:
1567 	if (new_index)
1568 		fclose(new_index);
1569 	free(new_fileindex_path);
1570 	return err;
1571 }
1572 
1573 static const struct got_error *
1574 find_tree_entry_for_checkout(int *entry_type, char **tree_relpath,
1575     struct got_object_id **tree_id, const char *wt_relpath,
1576     struct got_worktree *worktree, struct got_repository *repo)
1577 {
1578 	const struct got_error *err = NULL;
1579 	struct got_object_id *id = NULL;
1580 	char *in_repo_path = NULL;
1581 	int is_root_wt = got_path_is_root_dir(worktree->path_prefix);
1582 
1583 	*entry_type = GOT_OBJ_TYPE_ANY;
1584 	*tree_relpath = NULL;
1585 	*tree_id = NULL;
1586 
1587 	if (wt_relpath[0] == '\0') {
1588 		/* Check out all files within the work tree. */
1589 		*entry_type = GOT_OBJ_TYPE_TREE;
1590 		*tree_relpath = strdup("");
1591 		if (*tree_relpath == NULL) {
1592 			err = got_error_from_errno("strdup");
1593 			goto done;
1594 		}
1595 		err = got_object_id_by_path(tree_id, repo,
1596 		    worktree->base_commit_id, worktree->path_prefix);
1597 		if (err)
1598 			goto done;
1599 		return NULL;
1600 	}
1601 
1602 	/* Check out a subset of files in the work tree. */
1603 
1604 	if (asprintf(&in_repo_path, "%s%s%s", worktree->path_prefix,
1605 	    is_root_wt ? "" : "/", wt_relpath) == -1) {
1606 		err = got_error_from_errno("asprintf");
1607 		goto done;
1608 	}
1609 
1610 	err = got_object_id_by_path(&id, repo, worktree->base_commit_id,
1611 	    in_repo_path);
1612 	if (err)
1613 		goto done;
1614 
1615 	free(in_repo_path);
1616 	in_repo_path = NULL;
1617 
1618 	err = got_object_get_type(entry_type, repo, id);
1619 	if (err)
1620 		goto done;
1621 
1622 	if (*entry_type == GOT_OBJ_TYPE_BLOB) {
1623 		/* Check out a single file. */
1624 		if (strchr(wt_relpath, '/')  == NULL) {
1625 			/* Check out a single file in work tree's root dir. */
1626 			in_repo_path = strdup(worktree->path_prefix);
1627 			if (in_repo_path == NULL) {
1628 				err = got_error_from_errno("strdup");
1629 				goto done;
1630 			}
1631 			*tree_relpath = strdup("");
1632 			if (*tree_relpath == NULL) {
1633 				err = got_error_from_errno("strdup");
1634 				goto done;
1635 			}
1636 		} else {
1637 			/* Check out a single file in a subdirectory. */
1638 			err = got_path_dirname(tree_relpath, wt_relpath);
1639 			if (err)
1640 				return err;
1641 			if (asprintf(&in_repo_path, "%s%s%s",
1642 			    worktree->path_prefix, is_root_wt ? "" : "/",
1643 			    *tree_relpath) == -1) {
1644 				err = got_error_from_errno("asprintf");
1645 				goto done;
1646 			}
1647 		}
1648 		err = got_object_id_by_path(tree_id, repo,
1649 		    worktree->base_commit_id, in_repo_path);
1650 	} else {
1651 		/* Check out all files within a subdirectory. */
1652 		*tree_id = got_object_id_dup(id);
1653 		if (*tree_id == NULL) {
1654 			err = got_error_from_errno("got_object_id_dup");
1655 			goto done;
1656 		}
1657 		*tree_relpath = strdup(wt_relpath);
1658 		if (*tree_relpath == NULL) {
1659 			err = got_error_from_errno("strdup");
1660 			goto done;
1661 		}
1662 	}
1663 done:
1664 	free(id);
1665 	free(in_repo_path);
1666 	if (err) {
1667 		*entry_type = GOT_OBJ_TYPE_ANY;
1668 		free(*tree_relpath);
1669 		*tree_relpath = NULL;
1670 		free(*tree_id);
1671 		*tree_id = NULL;
1672 	}
1673 	return err;
1674 }
1675 
1676 static const struct got_error *
1677 checkout_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
1678     const char *relpath, struct got_object_id *tree_id, const char *entry_name,
1679     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1680     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1681 {
1682 	const struct got_error *err = NULL;
1683 	struct got_commit_object *commit = NULL;
1684 	struct got_tree_object *tree = NULL;
1685 	struct got_fileindex_diff_tree_cb diff_cb;
1686 	struct diff_cb_arg arg;
1687 
1688 	err = ref_base_commit(worktree, repo);
1689 	if (err)
1690 		goto done;
1691 
1692 	err = got_object_open_as_commit(&commit, repo,
1693 	   worktree->base_commit_id);
1694 	if (err)
1695 		goto done;
1696 
1697 	err = got_object_open_as_tree(&tree, repo, tree_id);
1698 	if (err)
1699 		goto done;
1700 
1701 	if (entry_name &&
1702 	    got_object_tree_find_entry(tree, entry_name) == NULL) {
1703 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
1704 		goto done;
1705 	}
1706 
1707 	diff_cb.diff_old_new = diff_old_new;
1708 	diff_cb.diff_old = diff_old;
1709 	diff_cb.diff_new = diff_new;
1710 	arg.fileindex = fileindex;
1711 	arg.worktree = worktree;
1712 	arg.repo = repo;
1713 	arg.progress_cb = progress_cb;
1714 	arg.progress_arg = progress_arg;
1715 	arg.cancel_cb = cancel_cb;
1716 	arg.cancel_arg = cancel_arg;
1717 	err = got_fileindex_diff_tree(fileindex, tree, relpath,
1718 	    entry_name, repo, &diff_cb, &arg);
1719 done:
1720 	if (tree)
1721 		got_object_tree_close(tree);
1722 	if (commit)
1723 		got_object_commit_close(commit);
1724 	return err;
1725 }
1726 
1727 const struct got_error *
1728 got_worktree_checkout_files(struct got_worktree *worktree, const char *path,
1729     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
1730     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1731 {
1732 	const struct got_error *err = NULL, *sync_err, *unlockerr;
1733 	struct got_commit_object *commit = NULL;
1734 	struct got_object_id *tree_id = NULL;
1735 	struct got_tree_object *tree = NULL;
1736 	struct got_fileindex *fileindex = NULL;
1737 	char *fileindex_path = NULL;
1738 	char *relpath = NULL, *entry_name = NULL;
1739 	int entry_type;
1740 
1741 	err = lock_worktree(worktree, LOCK_EX);
1742 	if (err)
1743 		return err;
1744 
1745 	err = find_tree_entry_for_checkout(&entry_type, &relpath, &tree_id,
1746 	    path, worktree, repo);
1747 	if (err)
1748 		goto done;
1749 
1750 	if (entry_type == GOT_OBJ_TYPE_BLOB) {
1751 		entry_name = basename(path);
1752 		if (entry_name == NULL) {
1753 			err = got_error_from_errno2("basename", path);
1754 			goto done;
1755 		}
1756 	}
1757 
1758 	/*
1759 	 * Read the file index.
1760 	 * Checking out files is supposed to be an idempotent operation.
1761 	 * If the on-disk file index is incomplete we will try to complete it.
1762 	 */
1763 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
1764 	if (err)
1765 		goto done;
1766 
1767 	err = checkout_files(worktree, fileindex, relpath, tree_id, entry_name,
1768 	    repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
1769 	if (err == NULL) {
1770 		struct bump_base_commit_id_arg bbc_arg;
1771 		bbc_arg.base_commit_id = worktree->base_commit_id;
1772 		bbc_arg.entry_name = entry_name;
1773 		bbc_arg.path = path;
1774 		bbc_arg.path_len = strlen(path);
1775 		bbc_arg.progress_cb = progress_cb;
1776 		bbc_arg.progress_arg = progress_arg;
1777 		err = got_fileindex_for_each_entry_safe(fileindex,
1778 		    bump_base_commit_id, &bbc_arg);
1779 	}
1780 	sync_err = sync_fileindex(fileindex, fileindex_path);
1781 	if (sync_err && err == NULL)
1782 		err = sync_err;
1783 done:
1784 	free(fileindex_path);
1785 	free(relpath);
1786 	if (tree)
1787 		got_object_tree_close(tree);
1788 	if (commit)
1789 		got_object_commit_close(commit);
1790 	if (fileindex)
1791 		got_fileindex_free(fileindex);
1792 	unlockerr = lock_worktree(worktree, LOCK_SH);
1793 	if (unlockerr && err == NULL)
1794 		err = unlockerr;
1795 	return err;
1796 }
1797 
1798 struct merge_file_cb_arg {
1799     struct got_worktree *worktree;
1800     struct got_fileindex *fileindex;
1801     got_worktree_checkout_cb progress_cb;
1802     void *progress_arg;
1803     got_worktree_cancel_cb cancel_cb;
1804     void *cancel_arg;
1805     struct got_object_id *commit_id2;
1806 };
1807 
1808 static const struct got_error *
1809 merge_file_cb(void *arg, struct got_blob_object *blob1,
1810     struct got_blob_object *blob2, struct got_object_id *id1,
1811     struct got_object_id *id2, const char *path1, const char *path2,
1812     struct got_repository *repo)
1813 {
1814 	static const struct got_error *err = NULL;
1815 	struct merge_file_cb_arg *a = arg;
1816 	struct got_fileindex_entry *ie;
1817 	char *ondisk_path = NULL;
1818 	struct stat sb;
1819 	unsigned char status;
1820 	int local_changes_subsumed;
1821 
1822 	if (blob1 && blob2) {
1823 		ie = got_fileindex_entry_get(a->fileindex, path2);
1824 		if (ie == NULL)
1825 			return (*a->progress_cb)(a->progress_arg,
1826 			    GOT_STATUS_MISSING, path2);
1827 
1828 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1829 		    path2) == -1)
1830 			return got_error_from_errno("asprintf");
1831 
1832 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1833 		if (err)
1834 			goto done;
1835 
1836 		if (status == GOT_STATUS_DELETE) {
1837 			err = (*a->progress_cb)(a->progress_arg,
1838 			    GOT_STATUS_MERGE, path2);
1839 			goto done;
1840 		}
1841 		if (status != GOT_STATUS_NO_CHANGE &&
1842 		    status != GOT_STATUS_MODIFY &&
1843 		    status != GOT_STATUS_CONFLICT &&
1844 		    status != GOT_STATUS_ADD) {
1845 			err = (*a->progress_cb)(a->progress_arg, status, path2);
1846 			goto done;
1847 		}
1848 
1849 		err = merge_blob(&local_changes_subsumed, a->worktree, blob1,
1850 		    ondisk_path, path2, sb.st_mode, blob2, a->commit_id2, repo,
1851 		    a->progress_cb, a->progress_arg);
1852 	} else if (blob1) {
1853 		ie = got_fileindex_entry_get(a->fileindex, path1);
1854 		if (ie == NULL)
1855 			return (*a->progress_cb)(a->progress_arg,
1856 			    GOT_STATUS_MISSING, path2);
1857 
1858 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1859 		    path1) == -1)
1860 			return got_error_from_errno("asprintf");
1861 
1862 		err = get_file_status(&status, &sb, ie, ondisk_path, repo);
1863 		if (err)
1864 			goto done;
1865 
1866 		switch (status) {
1867 		case GOT_STATUS_NO_CHANGE:
1868 			err = (*a->progress_cb)(a->progress_arg,
1869 			    GOT_STATUS_DELETE, path1);
1870 			if (err)
1871 				goto done;
1872 			err = remove_ondisk_file(a->worktree->root_path, path1);
1873 			if (err)
1874 				goto done;
1875 			if (ie)
1876 				got_fileindex_entry_mark_deleted_from_disk(ie);
1877 			break;
1878 		case GOT_STATUS_DELETE:
1879 		case GOT_STATUS_MISSING:
1880 			err = (*a->progress_cb)(a->progress_arg,
1881 			    GOT_STATUS_DELETE, path1);
1882 			if (err)
1883 				goto done;
1884 			if (ie)
1885 				got_fileindex_entry_mark_deleted_from_disk(ie);
1886 			break;
1887 		case GOT_STATUS_ADD:
1888 		case GOT_STATUS_MODIFY:
1889 		case GOT_STATUS_CONFLICT:
1890 			err = (*a->progress_cb)(a->progress_arg,
1891 			    GOT_STATUS_CANNOT_DELETE, path1);
1892 			if (err)
1893 				goto done;
1894 			break;
1895 		case GOT_STATUS_OBSTRUCTED:
1896 			err = (*a->progress_cb)(a->progress_arg, status, path1);
1897 			if (err)
1898 				goto done;
1899 			break;
1900 		default:
1901 			break;
1902 		}
1903 	} else if (blob2) {
1904 		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
1905 		    path2) == -1)
1906 			return got_error_from_errno("asprintf");
1907 		ie = got_fileindex_entry_get(a->fileindex, path2);
1908 		if (ie) {
1909 			err = get_file_status(&status, &sb, ie, ondisk_path,
1910 			    repo);
1911 			if (err)
1912 				goto done;
1913 			if (status != GOT_STATUS_NO_CHANGE &&
1914 			    status != GOT_STATUS_MODIFY &&
1915 			    status != GOT_STATUS_CONFLICT &&
1916 			    status != GOT_STATUS_ADD) {
1917 				err = (*a->progress_cb)(a->progress_arg,
1918 				    status, path2);
1919 				goto done;
1920 			}
1921 			err = merge_blob(&local_changes_subsumed, a->worktree,
1922 			    NULL, ondisk_path, path2, sb.st_mode, blob2,
1923 			    a->commit_id2, repo,
1924 			    a->progress_cb, a->progress_arg);
1925 			if (status == GOT_STATUS_DELETE) {
1926 				err = update_blob_fileindex_entry(a->worktree,
1927 				    a->fileindex, ie, ondisk_path, ie->path,
1928 				    blob2, 0);
1929 				if (err)
1930 					goto done;
1931 			}
1932 		} else {
1933 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1934 			err = install_blob(a->worktree, ondisk_path, path2,
1935 			    /* XXX get this from parent tree! */
1936 			    GOT_DEFAULT_FILE_MODE,
1937 			    sb.st_mode, blob2, 0, 0, repo,
1938 			    a->progress_cb, a->progress_arg);
1939 			if (err)
1940 				goto done;
1941 			err = got_fileindex_entry_alloc(&ie,
1942 			    ondisk_path, path2, NULL, NULL);
1943 			if (err)
1944 				goto done;
1945 			err = got_fileindex_entry_add(a->fileindex, ie);
1946 			if (err) {
1947 				got_fileindex_entry_free(ie);
1948 				goto done;
1949 			}
1950 		}
1951 	}
1952 done:
1953 	free(ondisk_path);
1954 	return err;
1955 }
1956 
1957 struct check_merge_ok_arg {
1958 	struct got_worktree *worktree;
1959 	struct got_repository *repo;
1960 };
1961 
1962 static const struct got_error *
1963 check_merge_ok(void *arg, struct got_fileindex_entry *ie)
1964 {
1965 	const struct got_error *err = NULL;
1966 	struct check_merge_ok_arg *a = arg;
1967 	unsigned char status;
1968 	struct stat sb;
1969 	char *ondisk_path;
1970 
1971 	/* Reject merges into a work tree with mixed base commits. */
1972 	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
1973 	    SHA1_DIGEST_LENGTH))
1974 		return got_error(GOT_ERR_MIXED_COMMITS);
1975 
1976 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
1977 	    == -1)
1978 		return got_error_from_errno("asprintf");
1979 
1980 	/* Reject merges into a work tree with conflicted files. */
1981 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
1982 	if (err)
1983 		return err;
1984 	if (status == GOT_STATUS_CONFLICT)
1985 		return got_error(GOT_ERR_CONFLICTS);
1986 
1987 	return NULL;
1988 }
1989 
1990 static const struct got_error *
1991 merge_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
1992     const char *fileindex_path, struct got_object_id *commit_id1,
1993     struct got_object_id *commit_id2, struct got_repository *repo,
1994     got_worktree_checkout_cb progress_cb, void *progress_arg,
1995     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
1996 {
1997 	const struct got_error *err = NULL, *sync_err;
1998 	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
1999 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
2000 	struct merge_file_cb_arg arg;
2001 
2002 	if (commit_id1) {
2003 		err = got_object_id_by_path(&tree_id1, repo, commit_id1,
2004 		    worktree->path_prefix);
2005 		if (err)
2006 			goto done;
2007 
2008 		err = got_object_open_as_tree(&tree1, repo, tree_id1);
2009 		if (err)
2010 			goto done;
2011 	}
2012 
2013 	err = got_object_id_by_path(&tree_id2, repo, commit_id2,
2014 	    worktree->path_prefix);
2015 	if (err)
2016 		goto done;
2017 
2018 	err = got_object_open_as_tree(&tree2, repo, tree_id2);
2019 	if (err)
2020 		goto done;
2021 
2022 	arg.worktree = worktree;
2023 	arg.fileindex = fileindex;
2024 	arg.progress_cb = progress_cb;
2025 	arg.progress_arg = progress_arg;
2026 	arg.cancel_cb = cancel_cb;
2027 	arg.cancel_arg = cancel_arg;
2028 	arg.commit_id2 = commit_id2;
2029 	err = got_diff_tree(tree1, tree2, "", "", repo, merge_file_cb, &arg);
2030 	sync_err = sync_fileindex(fileindex, fileindex_path);
2031 	if (sync_err && err == NULL)
2032 		err = sync_err;
2033 done:
2034 	if (tree1)
2035 		got_object_tree_close(tree1);
2036 	if (tree2)
2037 		got_object_tree_close(tree2);
2038 	return err;
2039 }
2040 
2041 const struct got_error *
2042 got_worktree_merge_files(struct got_worktree *worktree,
2043     struct got_object_id *commit_id1, struct got_object_id *commit_id2,
2044     struct got_repository *repo, got_worktree_checkout_cb progress_cb,
2045     void *progress_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2046 {
2047 	const struct got_error *err, *unlockerr;
2048 	char *fileindex_path = NULL;
2049 	struct got_fileindex *fileindex = NULL;
2050 	struct check_merge_ok_arg mok_arg;
2051 
2052 	err = lock_worktree(worktree, LOCK_EX);
2053 	if (err)
2054 		return err;
2055 
2056 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2057 	if (err)
2058 		goto done;
2059 
2060 	mok_arg.worktree = worktree;
2061 	mok_arg.repo = repo;
2062 	err = got_fileindex_for_each_entry_safe(fileindex, check_merge_ok,
2063 	    &mok_arg);
2064 	if (err)
2065 		goto done;
2066 
2067 	err = merge_files(worktree, fileindex, fileindex_path, commit_id1,
2068 	    commit_id2, repo, progress_cb, progress_arg, cancel_cb, cancel_arg);
2069 done:
2070 	if (fileindex)
2071 		got_fileindex_free(fileindex);
2072 	free(fileindex_path);
2073 	unlockerr = lock_worktree(worktree, LOCK_SH);
2074 	if (unlockerr && err == NULL)
2075 		err = unlockerr;
2076 	return err;
2077 }
2078 
2079 struct diff_dir_cb_arg {
2080     struct got_fileindex *fileindex;
2081     struct got_worktree *worktree;
2082     const char *status_path;
2083     size_t status_path_len;
2084     struct got_repository *repo;
2085     got_worktree_status_cb status_cb;
2086     void *status_arg;
2087     got_worktree_cancel_cb cancel_cb;
2088     void *cancel_arg;
2089 };
2090 
2091 static const struct got_error *
2092 report_file_status(struct got_fileindex_entry *ie, const char *abspath,
2093     got_worktree_status_cb status_cb, void *status_arg,
2094     struct got_repository *repo)
2095 {
2096 	const struct got_error *err = NULL;
2097 	unsigned char status = GOT_STATUS_NO_CHANGE;
2098 	struct stat sb;
2099 	struct got_object_id blob_id, commit_id;
2100 
2101 	err = get_file_status(&status, &sb, ie, abspath, repo);
2102 	if (err == NULL && status != GOT_STATUS_NO_CHANGE) {
2103 		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2104 		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2105 		err = (*status_cb)(status_arg, status, ie->path, &blob_id,
2106 		    &commit_id);
2107 	}
2108 	return err;
2109 }
2110 
2111 static const struct got_error *
2112 status_old_new(void *arg, struct got_fileindex_entry *ie,
2113     struct dirent *de, const char *parent_path)
2114 {
2115 	const struct got_error *err = NULL;
2116 	struct diff_dir_cb_arg *a = arg;
2117 	char *abspath;
2118 
2119 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2120 		return got_error(GOT_ERR_CANCELLED);
2121 
2122 	if (got_path_cmp(parent_path, a->status_path) != 0 &&
2123 	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
2124 		return NULL;
2125 
2126 	if (parent_path[0]) {
2127 		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
2128 		    parent_path, de->d_name) == -1)
2129 			return got_error_from_errno("asprintf");
2130 	} else {
2131 		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
2132 		    de->d_name) == -1)
2133 			return got_error_from_errno("asprintf");
2134 	}
2135 
2136 	err = report_file_status(ie, abspath, a->status_cb, a->status_arg,
2137 	    a->repo);
2138 	free(abspath);
2139 	return err;
2140 }
2141 
2142 static const struct got_error *
2143 status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
2144 {
2145 	struct diff_dir_cb_arg *a = arg;
2146 	struct got_object_id blob_id, commit_id;
2147 	unsigned char status;
2148 
2149 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2150 		return got_error(GOT_ERR_CANCELLED);
2151 
2152 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2153 		return NULL;
2154 
2155 	memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2156 	memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
2157 	if (got_fileindex_entry_has_file_on_disk(ie))
2158 		status = GOT_STATUS_MISSING;
2159 	else
2160 		status = GOT_STATUS_DELETE;
2161 	return (*a->status_cb)(a->status_arg, status, ie->path, &blob_id,
2162 	    &commit_id);
2163 }
2164 
2165 static const struct got_error *
2166 status_new(void *arg, struct dirent *de, const char *parent_path)
2167 {
2168 	const struct got_error *err = NULL;
2169 	struct diff_dir_cb_arg *a = arg;
2170 	char *path = NULL;
2171 
2172 	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
2173 		return got_error(GOT_ERR_CANCELLED);
2174 
2175 	if (de->d_type == DT_DIR)
2176 		return NULL;
2177 
2178 	/* XXX ignore symlinks for now */
2179 	if (de->d_type == DT_LNK)
2180 		return NULL;
2181 
2182 	if (!got_path_is_child(parent_path, a->status_path, a->status_path_len))
2183 		return NULL;
2184 
2185 	if (parent_path[0]) {
2186 		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
2187 			return got_error_from_errno("asprintf");
2188 	} else {
2189 		path = de->d_name;
2190 	}
2191 
2192 	err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED, path,
2193 	    NULL, NULL);
2194 	if (parent_path[0])
2195 		free(path);
2196 	return err;
2197 }
2198 
2199 static const struct got_error *
2200 worktree_status(struct got_worktree *worktree, const char *path,
2201     struct got_fileindex *fileindex, struct got_repository *repo,
2202     got_worktree_status_cb status_cb, void *status_arg,
2203     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2204 {
2205 	const struct got_error *err = NULL;
2206 	DIR *workdir = NULL;
2207 	struct got_fileindex_diff_dir_cb fdiff_cb;
2208 	struct diff_dir_cb_arg arg;
2209 	char *ondisk_path = NULL;
2210 
2211 	if (asprintf(&ondisk_path, "%s%s%s",
2212 	    worktree->root_path, path[0] ? "/" : "", path) == -1) {
2213 		err = got_error_from_errno("asprintf");
2214 		goto done;
2215 	}
2216 	workdir = opendir(ondisk_path);
2217 	if (workdir == NULL) {
2218 		if (errno == ENOTDIR || errno == ENOENT) {
2219 			struct got_fileindex_entry *ie;
2220 			ie = got_fileindex_entry_get(fileindex, path);
2221 			if (ie == NULL) {
2222 				err = got_error(GOT_ERR_BAD_PATH);
2223 				goto done;
2224 			}
2225 			err = report_file_status(ie, ondisk_path,
2226 			    status_cb, status_arg, repo);
2227 			goto done;
2228 		} else {
2229 			err = got_error_from_errno2("opendir", ondisk_path);
2230 			goto done;
2231 		}
2232 	}
2233 	fdiff_cb.diff_old_new = status_old_new;
2234 	fdiff_cb.diff_old = status_old;
2235 	fdiff_cb.diff_new = status_new;
2236 	arg.fileindex = fileindex;
2237 	arg.worktree = worktree;
2238 	arg.status_path = path;
2239 	arg.status_path_len = strlen(path);
2240 	arg.repo = repo;
2241 	arg.status_cb = status_cb;
2242 	arg.status_arg = status_arg;
2243 	arg.cancel_cb = cancel_cb;
2244 	arg.cancel_arg = cancel_arg;
2245 	err = got_fileindex_diff_dir(fileindex, workdir, worktree->root_path,
2246 	    path, repo, &fdiff_cb, &arg);
2247 done:
2248 	if (workdir)
2249 		closedir(workdir);
2250 	free(ondisk_path);
2251 	return err;
2252 }
2253 
2254 const struct got_error *
2255 got_worktree_status(struct got_worktree *worktree, const char *path,
2256     struct got_repository *repo, got_worktree_status_cb status_cb,
2257     void *status_arg, got_worktree_cancel_cb cancel_cb, void *cancel_arg)
2258 {
2259 	const struct got_error *err = NULL;
2260 	char *fileindex_path = NULL;
2261 	struct got_fileindex *fileindex = NULL;
2262 
2263 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2264 	if (err)
2265 		return err;
2266 
2267 	err = worktree_status(worktree, path, fileindex, repo,
2268 	    status_cb, status_arg, cancel_cb, cancel_arg);
2269 	free(fileindex_path);
2270 	got_fileindex_free(fileindex);
2271 	return err;
2272 }
2273 
2274 const struct got_error *
2275 got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
2276     const char *arg)
2277 {
2278 	const struct got_error *err = NULL;
2279 	char *resolved, *cwd = NULL, *path = NULL;
2280 	size_t len;
2281 
2282 	*wt_path = NULL;
2283 
2284 	resolved = realpath(arg, NULL);
2285 	if (resolved == NULL) {
2286 		if (errno != ENOENT)
2287 			return got_error_from_errno2("realpath", arg);
2288 		cwd = getcwd(NULL, 0);
2289 		if (cwd == NULL)
2290 			return got_error_from_errno("getcwd");
2291 		if (asprintf(&resolved, "%s/%s", cwd, arg) == -1) {
2292 			err = got_error_from_errno("asprintf");
2293 			goto done;
2294 		}
2295 	}
2296 
2297 	if (strncmp(got_worktree_get_root_path(worktree), resolved,
2298 	    strlen(got_worktree_get_root_path(worktree)))) {
2299 		err = got_error(GOT_ERR_BAD_PATH);
2300 		goto done;
2301 	}
2302 
2303 	if (strlen(resolved) > strlen(got_worktree_get_root_path(worktree))) {
2304 		err = got_path_skip_common_ancestor(&path,
2305 		    got_worktree_get_root_path(worktree), resolved);
2306 		if (err)
2307 			goto done;
2308 	} else {
2309 		path = strdup("");
2310 		if (path == NULL) {
2311 			err = got_error_from_errno("strdup");
2312 			goto done;
2313 		}
2314 	}
2315 
2316 	/* XXX status walk can't deal with trailing slash! */
2317 	len = strlen(path);
2318 	while (path[len - 1] == '/') {
2319 		path[len - 1] = '\0';
2320 		len--;
2321 	}
2322 done:
2323 	free(resolved);
2324 	free(cwd);
2325 	if (err == NULL)
2326 		*wt_path = path;
2327 	else
2328 		free(path);
2329 	return err;
2330 }
2331 
2332 static const struct got_error *
2333 schedule_addition(const char *ondisk_path, struct got_fileindex *fileindex,
2334     const char *relpath, got_worktree_status_cb status_cb, void *status_arg,
2335     struct got_repository *repo)
2336 {
2337 	const struct got_error *err = NULL;
2338 	struct got_fileindex_entry *ie;
2339 
2340 	/* Re-adding an existing entry is a no-op. */
2341 	if (got_fileindex_entry_get(fileindex, relpath) != NULL)
2342 		return NULL;
2343 
2344 	err = got_fileindex_entry_alloc(&ie, ondisk_path, relpath, NULL, NULL);
2345 	if (err)
2346 		return err;
2347 
2348 	err = got_fileindex_entry_add(fileindex, ie);
2349 	if (err) {
2350 		got_fileindex_entry_free(ie);
2351 		return err;
2352 	}
2353 
2354 	return report_file_status(ie, relpath, status_cb, status_arg, repo);
2355 }
2356 
2357 const struct got_error *
2358 got_worktree_schedule_add(struct got_worktree *worktree,
2359     struct got_pathlist_head *ondisk_paths,
2360     got_worktree_status_cb status_cb, void *status_arg,
2361     struct got_repository *repo)
2362 {
2363 	struct got_fileindex *fileindex = NULL;
2364 	char *fileindex_path = NULL;
2365 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2366 	struct got_pathlist_entry *pe;
2367 
2368 	err = lock_worktree(worktree, LOCK_EX);
2369 	if (err)
2370 		return err;
2371 
2372 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2373 	if (err)
2374 		goto done;
2375 
2376 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2377 		char *relpath;
2378 		err = got_path_skip_common_ancestor(&relpath,
2379 		    got_worktree_get_root_path(worktree), pe->path);
2380 		if (err)
2381 			break;
2382 		err = schedule_addition(pe->path, fileindex, relpath,
2383 		    status_cb, status_arg, repo);
2384 		free(relpath);
2385 		if (err)
2386 			break;
2387 	}
2388 	sync_err = sync_fileindex(fileindex, fileindex_path);
2389 	if (sync_err && err == NULL)
2390 		err = sync_err;
2391 done:
2392 	free(fileindex_path);
2393 	if (fileindex)
2394 		got_fileindex_free(fileindex);
2395 	unlockerr = lock_worktree(worktree, LOCK_SH);
2396 	if (unlockerr && err == NULL)
2397 		err = unlockerr;
2398 	return err;
2399 }
2400 
2401 static const struct got_error *
2402 schedule_for_deletion(const char *ondisk_path, struct got_fileindex *fileindex,
2403     const char *relpath, int delete_local_mods,
2404     got_worktree_status_cb status_cb, void *status_arg,
2405     struct got_repository *repo)
2406 {
2407 	const struct got_error *err = NULL;
2408 	struct got_fileindex_entry *ie = NULL;
2409 	unsigned char status;
2410 	struct stat sb;
2411 
2412 	ie = got_fileindex_entry_get(fileindex, relpath);
2413 	if (ie == NULL)
2414 		return got_error(GOT_ERR_BAD_PATH);
2415 
2416 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2417 	if (err)
2418 		return err;
2419 
2420 	if (status != GOT_STATUS_NO_CHANGE) {
2421 		if (status == GOT_STATUS_DELETE)
2422 			return got_error_set_errno(ENOENT, ondisk_path);
2423 		if (status != GOT_STATUS_MODIFY)
2424 			return got_error(GOT_ERR_FILE_STATUS);
2425 		if (!delete_local_mods)
2426 			return got_error(GOT_ERR_FILE_MODIFIED);
2427 	}
2428 
2429 	if (unlink(ondisk_path) != 0)
2430 		return got_error_from_errno2("unlink", ondisk_path);
2431 
2432 	got_fileindex_entry_mark_deleted_from_disk(ie);
2433 	return report_file_status(ie, ondisk_path, status_cb, status_arg, repo);
2434 }
2435 
2436 const struct got_error *
2437 got_worktree_schedule_delete(struct got_worktree *worktree,
2438     struct got_pathlist_head *ondisk_paths, int delete_local_mods,
2439     got_worktree_status_cb status_cb, void *status_arg,
2440     struct got_repository *repo)
2441 {
2442 	struct got_fileindex *fileindex = NULL;
2443 	char *fileindex_path = NULL;
2444 	const struct got_error *err = NULL, *sync_err, *unlockerr;
2445 	struct got_pathlist_entry *pe;
2446 
2447 	err = lock_worktree(worktree, LOCK_EX);
2448 	if (err)
2449 		return err;
2450 
2451 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2452 	if (err)
2453 		goto done;
2454 
2455 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2456 		char *relpath;
2457 		err = got_path_skip_common_ancestor(&relpath,
2458 		    got_worktree_get_root_path(worktree), pe->path);
2459 		if (err)
2460 			break;
2461 		err = schedule_for_deletion(pe->path, fileindex, relpath,
2462 		    delete_local_mods, status_cb, status_arg, repo);
2463 		free(relpath);
2464 		if (err)
2465 			break;
2466 	}
2467 	sync_err = sync_fileindex(fileindex, fileindex_path);
2468 	if (sync_err && err == NULL)
2469 		err = sync_err;
2470 done:
2471 	free(fileindex_path);
2472 	if (fileindex)
2473 		got_fileindex_free(fileindex);
2474 	unlockerr = lock_worktree(worktree, LOCK_SH);
2475 	if (unlockerr && err == NULL)
2476 		err = unlockerr;
2477 	return err;
2478 }
2479 
2480 static const struct got_error *
2481 revert_file(struct got_worktree *worktree, struct got_fileindex *fileindex,
2482     const char *ondisk_path,
2483     got_worktree_checkout_cb progress_cb, void *progress_arg,
2484     struct got_repository *repo)
2485 {
2486 	const struct got_error *err = NULL;
2487 	char *relpath = NULL, *parent_path = NULL;
2488 	struct got_fileindex_entry *ie;
2489 	struct got_tree_object *tree = NULL;
2490 	struct got_object_id *tree_id = NULL;
2491 	const struct got_tree_entry *te;
2492 	char *tree_path = NULL, *te_name;
2493 	struct got_blob_object *blob = NULL;
2494 	unsigned char status;
2495 	struct stat sb;
2496 
2497 	err = got_path_skip_common_ancestor(&relpath,
2498 	    got_worktree_get_root_path(worktree), ondisk_path);
2499 	if (err)
2500 		goto done;
2501 
2502 	ie = got_fileindex_entry_get(fileindex, relpath);
2503 	if (ie == NULL) {
2504 		err = got_error(GOT_ERR_BAD_PATH);
2505 		goto done;
2506 	}
2507 
2508 	/* Construct in-repository path of tree which contains this blob. */
2509 	err = got_path_dirname(&parent_path, ie->path);
2510 	if (err) {
2511 		if (err->code != GOT_ERR_BAD_PATH)
2512 			goto done;
2513 		parent_path = strdup("/");
2514 		if (parent_path == NULL) {
2515 			err = got_error_from_errno("strdup");
2516 			goto done;
2517 		}
2518 	}
2519 	if (got_path_is_root_dir(worktree->path_prefix)) {
2520 		tree_path = strdup(parent_path);
2521 		if (tree_path == NULL) {
2522 			err = got_error_from_errno("strdup");
2523 			goto done;
2524 		}
2525 	} else {
2526 		if (got_path_is_root_dir(parent_path)) {
2527 			tree_path = strdup(worktree->path_prefix);
2528 			if (tree_path == NULL) {
2529 				err = got_error_from_errno("strdup");
2530 				goto done;
2531 			}
2532 		} else {
2533 			if (asprintf(&tree_path, "%s/%s",
2534 			    worktree->path_prefix, parent_path) == -1) {
2535 				err = got_error_from_errno("asprintf");
2536 				goto done;
2537 			}
2538 		}
2539 	}
2540 
2541 	err = got_object_id_by_path(&tree_id, repo, worktree->base_commit_id,
2542 	    tree_path);
2543 	if (err)
2544 		goto done;
2545 
2546 	err = got_object_open_as_tree(&tree, repo, tree_id);
2547 	if (err)
2548 		goto done;
2549 
2550 	te_name = basename(ie->path);
2551 	if (te_name == NULL) {
2552 		err = got_error_from_errno2("basename", ie->path);
2553 		goto done;
2554 	}
2555 
2556 	err = get_file_status(&status, &sb, ie, ondisk_path, repo);
2557 	if (err)
2558 		goto done;
2559 
2560 	te = got_object_tree_find_entry(tree, te_name);
2561 	if (te == NULL && status != GOT_STATUS_ADD) {
2562 		err = got_error(GOT_ERR_NO_TREE_ENTRY);
2563 		goto done;
2564 	}
2565 
2566 	switch (status) {
2567 	case GOT_STATUS_ADD:
2568 		err = (*progress_cb)(progress_arg, GOT_STATUS_REVERT, ie->path);
2569 		if (err)
2570 			goto done;
2571 		got_fileindex_entry_remove(fileindex, ie);
2572 		break;
2573 	case GOT_STATUS_DELETE:
2574 	case GOT_STATUS_MODIFY:
2575 	case GOT_STATUS_CONFLICT:
2576 	case GOT_STATUS_MISSING: {
2577 		struct got_object_id id;
2578 		memcpy(id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
2579 		err = got_object_open_as_blob(&blob, repo, &id, 8192);
2580 		if (err)
2581 			goto done;
2582 		err = install_blob(worktree, ondisk_path, ie->path,
2583 		    te->mode, sb.st_mode, blob, 0, 1, repo, progress_cb,
2584 		    progress_arg);
2585 		if (err)
2586 			goto done;
2587 		if (status == GOT_STATUS_DELETE) {
2588 			err = update_blob_fileindex_entry(worktree,
2589 			    fileindex, ie, ondisk_path, ie->path, blob, 1);
2590 			if (err)
2591 				goto done;
2592 		}
2593 		break;
2594 	}
2595 	default:
2596 			goto done;
2597 	}
2598 done:
2599 	free(relpath);
2600 	free(parent_path);
2601 	free(tree_path);
2602 	if (blob)
2603 		got_object_blob_close(blob);
2604 	if (tree)
2605 		got_object_tree_close(tree);
2606 	free(tree_id);
2607 	return err;
2608 }
2609 
2610 const struct got_error *
2611 got_worktree_revert(struct got_worktree *worktree,
2612     struct got_pathlist_head *ondisk_paths,
2613     got_worktree_checkout_cb progress_cb, void *progress_arg,
2614     struct got_repository *repo)
2615 {
2616 	struct got_fileindex *fileindex = NULL;
2617 	char *fileindex_path = NULL;
2618 	const struct got_error *err = NULL, *unlockerr = NULL;
2619 	const struct got_error *sync_err = NULL;
2620 	struct got_pathlist_entry *pe;
2621 
2622 	err = lock_worktree(worktree, LOCK_EX);
2623 	if (err)
2624 		return err;
2625 
2626 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
2627 	if (err)
2628 		goto done;
2629 
2630 	TAILQ_FOREACH(pe, ondisk_paths, entry) {
2631 		err = revert_file(worktree, fileindex, pe->path,
2632 		    progress_cb, progress_arg, repo);
2633 		if (err)
2634 			break;
2635 	}
2636 	sync_err = sync_fileindex(fileindex, fileindex_path);
2637 	if (sync_err && err == NULL)
2638 		err = sync_err;
2639 done:
2640 	free(fileindex_path);
2641 	if (fileindex)
2642 		got_fileindex_free(fileindex);
2643 	unlockerr = lock_worktree(worktree, LOCK_SH);
2644 	if (unlockerr && err == NULL)
2645 		err = unlockerr;
2646 	return err;
2647 }
2648 
2649 static void
2650 free_commitable(struct got_commitable *ct)
2651 {
2652 	free(ct->path);
2653 	free(ct->in_repo_path);
2654 	free(ct->ondisk_path);
2655 	free(ct->blob_id);
2656 	free(ct->base_blob_id);
2657 	free(ct->base_commit_id);
2658 	free(ct);
2659 }
2660 
2661 struct collect_commitables_arg {
2662 	struct got_pathlist_head *commitable_paths;
2663 	struct got_repository *repo;
2664 	struct got_worktree *worktree;
2665 };
2666 
2667 static const struct got_error *
2668 collect_commitables(void *arg, unsigned char status, const char *relpath,
2669     struct got_object_id *blob_id, struct got_object_id *commit_id)
2670 {
2671 	struct collect_commitables_arg *a = arg;
2672 	const struct got_error *err = NULL;
2673 	struct got_commitable *ct = NULL;
2674 	struct got_pathlist_entry *new = NULL;
2675 	char *parent_path = NULL, *path = NULL;
2676 	struct stat sb;
2677 
2678 	if (status == GOT_STATUS_CONFLICT)
2679 		return got_error(GOT_ERR_COMMIT_CONFLICT);
2680 
2681 	if (status != GOT_STATUS_MODIFY && status != GOT_STATUS_ADD &&
2682 	    status != GOT_STATUS_DELETE)
2683 		return NULL;
2684 
2685 	if (asprintf(&path, "/%s", relpath) == -1) {
2686 		err = got_error_from_errno("asprintf");
2687 		goto done;
2688 	}
2689 	if (strcmp(path, "/") == 0) {
2690 		parent_path = strdup("");
2691 		if (parent_path == NULL)
2692 			return got_error_from_errno("strdup");
2693 	} else {
2694 		err = got_path_dirname(&parent_path, path);
2695 		if (err)
2696 			return err;
2697 	}
2698 
2699 	ct = calloc(1, sizeof(*ct));
2700 	if (ct == NULL) {
2701 		err = got_error_from_errno("calloc");
2702 		goto done;
2703 	}
2704 
2705 	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
2706 	    relpath) == -1) {
2707 		err = got_error_from_errno("asprintf");
2708 		goto done;
2709 	}
2710 	if (status == GOT_STATUS_DELETE) {
2711 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
2712 	} else {
2713 		if (lstat(ct->ondisk_path, &sb) != 0) {
2714 			err = got_error_from_errno2("lstat", ct->ondisk_path);
2715 			goto done;
2716 		}
2717 		ct->mode = sb.st_mode;
2718 	}
2719 
2720 	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
2721 	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
2722 	    relpath) == -1) {
2723 		err = got_error_from_errno("asprintf");
2724 		goto done;
2725 	}
2726 
2727 	ct->status = status;
2728 	ct->blob_id = NULL; /* will be filled in when blob gets created */
2729 	if (ct->status != GOT_STATUS_ADD) {
2730 		ct->base_blob_id = got_object_id_dup(blob_id);
2731 		if (ct->base_blob_id == NULL) {
2732 			err = got_error_from_errno("got_object_id_dup");
2733 			goto done;
2734 		}
2735 		ct->base_commit_id = got_object_id_dup(commit_id);
2736 		if (ct->base_commit_id == NULL) {
2737 			err = got_error_from_errno("got_object_id_dup");
2738 			goto done;
2739 		}
2740 	}
2741 	ct->path = strdup(path);
2742 	if (ct->path == NULL) {
2743 		err = got_error_from_errno("strdup");
2744 		goto done;
2745 	}
2746 	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
2747 done:
2748 	if (ct && (err || new == NULL))
2749 		free_commitable(ct);
2750 	free(parent_path);
2751 	free(path);
2752 	return err;
2753 }
2754 
2755 static const struct got_error *write_tree(struct got_object_id **,
2756     struct got_tree_object *, const char *, struct got_pathlist_head *,
2757     got_worktree_status_cb status_cb, void *status_arg,
2758     struct got_repository *);
2759 
2760 static const struct got_error *
2761 write_subtree(struct got_object_id **new_subtree_id,
2762     struct got_tree_entry *te, const char *parent_path,
2763     struct got_pathlist_head *commitable_paths,
2764     got_worktree_status_cb status_cb, void *status_arg,
2765     struct got_repository *repo)
2766 {
2767 	const struct got_error *err = NULL;
2768 	struct got_tree_object *subtree;
2769 	char *subpath;
2770 
2771 	if (asprintf(&subpath, "%s%s%s", parent_path,
2772 	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
2773 		return got_error_from_errno("asprintf");
2774 
2775 	err = got_object_open_as_tree(&subtree, repo, te->id);
2776 	if (err)
2777 		return err;
2778 
2779 	err = write_tree(new_subtree_id, subtree, subpath, commitable_paths,
2780 	    status_cb, status_arg, repo);
2781 	got_object_tree_close(subtree);
2782 	free(subpath);
2783 	return err;
2784 }
2785 
2786 static const struct got_error *
2787 match_ct_parent_path(int *match, struct got_commitable *ct, const char *path)
2788 {
2789 	const struct got_error *err = NULL;
2790 	char *ct_parent_path = NULL;
2791 
2792 	*match = 0;
2793 
2794 	if (strchr(ct->path, '/') == NULL) {
2795 		*match = got_path_is_root_dir(path);
2796 		return NULL;
2797 	}
2798 
2799 	err = got_path_dirname(&ct_parent_path, ct->path);
2800 	if (err)
2801 		return err;
2802 	*match = (strcmp(path, ct_parent_path) == 0);
2803 	free(ct_parent_path);
2804 	return err;
2805 }
2806 
2807 static mode_t
2808 get_ct_file_mode(struct got_commitable *ct)
2809 {
2810 	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
2811 }
2812 
2813 static const struct got_error *
2814 alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
2815     struct got_tree_entry *te, struct got_commitable *ct)
2816 {
2817 	const struct got_error *err = NULL;
2818 
2819 	*new_te = NULL;
2820 
2821 	err = got_object_tree_entry_dup(new_te, te);
2822 	if (err)
2823 		goto done;
2824 
2825 	(*new_te)->mode = get_ct_file_mode(ct);
2826 
2827 	free((*new_te)->id);
2828 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2829 	if ((*new_te)->id == NULL) {
2830 		err = got_error_from_errno("got_object_id_dup");
2831 		goto done;
2832 	}
2833 done:
2834 	if (err && *new_te) {
2835 		got_object_tree_entry_close(*new_te);
2836 		*new_te = NULL;
2837 	}
2838 	return err;
2839 }
2840 
2841 static const struct got_error *
2842 alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
2843     struct got_commitable *ct)
2844 {
2845 	const struct got_error *err = NULL;
2846 	char *ct_name;
2847 
2848 	 *new_te = NULL;
2849 
2850 	*new_te = calloc(1, sizeof(**new_te));
2851 	if (*new_te == NULL)
2852 		return got_error_from_errno("calloc");
2853 
2854 	ct_name = basename(ct->path);
2855 	if (ct_name == NULL) {
2856 		err = got_error_from_errno2("basename", ct->path);
2857 		goto done;
2858 	}
2859 	(*new_te)->name = strdup(ct_name);
2860 	if ((*new_te)->name == NULL) {
2861 		err = got_error_from_errno("strdup");
2862 		goto done;
2863 	}
2864 
2865 	(*new_te)->mode = get_ct_file_mode(ct);
2866 
2867 	(*new_te)->id = got_object_id_dup(ct->blob_id);
2868 	if ((*new_te)->id == NULL) {
2869 		err = got_error_from_errno("got_object_id_dup");
2870 		goto done;
2871 	}
2872 done:
2873 	if (err && *new_te) {
2874 		got_object_tree_entry_close(*new_te);
2875 		*new_te = NULL;
2876 	}
2877 	return err;
2878 }
2879 
2880 static const struct got_error *
2881 insert_tree_entry(struct got_tree_entry *new_te,
2882     struct got_pathlist_head *paths)
2883 {
2884 	const struct got_error *err = NULL;
2885 	struct got_pathlist_entry *new_pe;
2886 
2887 	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
2888 	if (err)
2889 		return err;
2890 	if (new_pe == NULL)
2891 		return got_error(GOT_ERR_TREE_DUP_ENTRY);
2892 	return NULL;
2893 }
2894 
2895 static const struct got_error *
2896 report_ct_status(struct got_commitable *ct,
2897     got_worktree_status_cb status_cb, void *status_arg)
2898 {
2899 	const char *ct_path = ct->path;
2900 	while (ct_path[0] == '/')
2901 		ct_path++;
2902 	return (*status_cb)(status_arg, ct->status, ct_path, ct->blob_id, NULL);
2903 }
2904 
2905 static const struct got_error *
2906 match_modified_subtree(int *modified, struct got_tree_entry *te,
2907     const char *base_tree_path, struct got_pathlist_head *commitable_paths)
2908 {
2909 	const struct got_error *err = NULL;
2910 	struct got_pathlist_entry *pe;
2911 	char *te_path;
2912 
2913 	*modified = 0;
2914 
2915 	if (asprintf(&te_path, "%s%s%s", base_tree_path,
2916 	    got_path_is_root_dir(base_tree_path) ? "" : "/",
2917 	    te->name) == -1)
2918 		return got_error_from_errno("asprintf");
2919 
2920 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2921 		struct got_commitable *ct = pe->data;
2922 		*modified = got_path_is_child(ct->in_repo_path, te_path,
2923 		    strlen(te_path));
2924 		 if (*modified)
2925 			break;
2926 	}
2927 
2928 	free(te_path);
2929 	return err;
2930 }
2931 
2932 static const struct got_error *
2933 match_deleted_or_modified_ct(struct got_commitable **ctp,
2934     struct got_tree_entry *te, const char *base_tree_path,
2935     struct got_pathlist_head *commitable_paths)
2936 {
2937 	const struct got_error *err = NULL;
2938 	struct got_pathlist_entry *pe;
2939 
2940 	*ctp = NULL;
2941 
2942 	TAILQ_FOREACH(pe, commitable_paths, entry) {
2943 		struct got_commitable *ct = pe->data;
2944 		char *ct_name = NULL;
2945 		int path_matches;
2946 
2947 		if (ct->status != GOT_STATUS_MODIFY &&
2948 		    ct->status != GOT_STATUS_DELETE)
2949 			continue;
2950 
2951 		if (got_object_id_cmp(ct->base_blob_id, te->id) != 0)
2952 			continue;
2953 
2954 		 err = match_ct_parent_path(&path_matches, ct, base_tree_path);
2955 		 if (err)
2956 			return err;
2957 		if (!path_matches)
2958 			continue;
2959 
2960 		ct_name = basename(pe->path);
2961 		if (ct_name == NULL)
2962 			return got_error_from_errno2("basename", pe->path);
2963 
2964 		if (strcmp(te->name, ct_name) != 0)
2965 			continue;
2966 
2967 		*ctp = ct;
2968 		break;
2969 	}
2970 
2971 	return err;
2972 }
2973 
2974 static const struct got_error *
2975 make_subtree_for_added_blob(struct got_tree_entry **new_tep,
2976     const char *child_path, const char *path_base_tree,
2977     struct got_pathlist_head *commitable_paths,
2978     got_worktree_status_cb status_cb, void *status_arg,
2979     struct got_repository *repo)
2980 {
2981 	const struct got_error *err = NULL;
2982 	struct got_tree_entry *new_te;
2983 	char *subtree_path;
2984 
2985 	*new_tep = NULL;
2986 
2987 	if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
2988 	    got_path_is_root_dir(path_base_tree) ? "" : "/",
2989 	    child_path) == -1)
2990 		return got_error_from_errno("asprintf");
2991 
2992 	new_te = calloc(1, sizeof(*new_te));
2993 	new_te->mode = S_IFDIR;
2994 	new_te->name = strdup(child_path);
2995 	if (new_te->name == NULL) {
2996 		err = got_error_from_errno("strdup");
2997 		got_object_tree_entry_close(new_te);
2998 		goto done;
2999 	}
3000 	err = write_tree(&new_te->id, NULL, subtree_path,
3001 	    commitable_paths, status_cb, status_arg, repo);
3002 	if (err) {
3003 		got_object_tree_entry_close(new_te);
3004 		goto done;
3005 	}
3006 done:
3007 	free(subtree_path);
3008 	if (err == NULL)
3009 		*new_tep = new_te;
3010 	return err;
3011 }
3012 
3013 static const struct got_error *
3014 write_tree(struct got_object_id **new_tree_id,
3015     struct got_tree_object *base_tree, const char *path_base_tree,
3016     struct got_pathlist_head *commitable_paths,
3017     got_worktree_status_cb status_cb, void *status_arg,
3018     struct got_repository *repo)
3019 {
3020 	const struct got_error *err = NULL;
3021 	const struct got_tree_entries *base_entries = NULL;
3022 	struct got_pathlist_head paths;
3023 	struct got_tree_entries new_tree_entries;
3024 	struct got_tree_entry *te, *new_te = NULL;
3025 	struct got_pathlist_entry *pe;
3026 
3027 	TAILQ_INIT(&paths);
3028 	new_tree_entries.nentries = 0;
3029 	SIMPLEQ_INIT(&new_tree_entries.head);
3030 
3031 	/* Insert, and recurse into, newly added entries first. */
3032 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3033 		struct got_commitable *ct = pe->data;
3034 		char *child_path = NULL, *slash;
3035 
3036 		if (ct->status != GOT_STATUS_ADD ||
3037 		    (ct->flags & GOT_COMMITABLE_ADDED))
3038 			continue;
3039 
3040 		 if (!got_path_is_child(pe->path, path_base_tree,
3041 		     strlen(path_base_tree)))
3042 			continue;
3043 
3044 		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
3045 		    pe->path);
3046 		if (err)
3047 			goto done;
3048 
3049 		slash = strchr(child_path, '/');
3050 		if (slash == NULL) {
3051 			err = alloc_added_blob_tree_entry(&new_te, ct);
3052 			if (err)
3053 				goto done;
3054 			err = report_ct_status(ct, status_cb, status_arg);
3055 			if (err)
3056 				goto done;
3057 			ct->flags |= GOT_COMMITABLE_ADDED;
3058 			err = insert_tree_entry(new_te, &paths);
3059 			if (err)
3060 				goto done;
3061 		} else {
3062 			*slash = '\0'; /* trim trailing path components */
3063 			if (base_tree == NULL ||
3064 			    got_object_tree_find_entry(base_tree, child_path)
3065 			    == NULL) {
3066 				err = make_subtree_for_added_blob(&new_te,
3067 				    child_path, path_base_tree,
3068 				    commitable_paths, status_cb, status_arg,
3069 				    repo);
3070 				if (err)
3071 					goto done;
3072 				err = insert_tree_entry(new_te, &paths);
3073 				if (err)
3074 					goto done;
3075 			}
3076 		}
3077 	}
3078 
3079 	if (base_tree) {
3080 		/* Handle modified and deleted entries. */
3081 		base_entries = got_object_tree_get_entries(base_tree);
3082 		SIMPLEQ_FOREACH(te, &base_entries->head, entry) {
3083 			struct got_commitable *ct = NULL;
3084 
3085 			if (S_ISDIR(te->mode)) {
3086 				int modified;
3087 				err = got_object_tree_entry_dup(&new_te, te);
3088 				if (err)
3089 					goto done;
3090 				err = match_modified_subtree(&modified, te,
3091 				    path_base_tree, commitable_paths);
3092 				if (err)
3093 					goto done;
3094 				/* Avoid recursion into unmodified subtrees. */
3095 				if (modified) {
3096 					free(new_te->id);
3097 					err = write_subtree(&new_te->id, te,
3098 					    path_base_tree, commitable_paths,
3099 					    status_cb, status_arg, repo);
3100 					if (err)
3101 						goto done;
3102 				}
3103 				err = insert_tree_entry(new_te, &paths);
3104 				if (err)
3105 					goto done;
3106 				continue;
3107 			}
3108 
3109 			err = match_deleted_or_modified_ct(&ct, te,
3110 			    path_base_tree, commitable_paths);
3111 			if (ct) {
3112 				/* NB: Deleted entries get dropped here. */
3113 				if (ct->status == GOT_STATUS_MODIFY) {
3114 					err = alloc_modified_blob_tree_entry(
3115 					    &new_te, te, ct);
3116 					if (err)
3117 						goto done;
3118 					err = insert_tree_entry(new_te, &paths);
3119 					if (err)
3120 						goto done;
3121 				}
3122 				err = report_ct_status(ct, status_cb,
3123 				    status_arg);
3124 				if (err)
3125 					goto done;
3126 			} else {
3127 				/* Entry is unchanged; just copy it. */
3128 				err = got_object_tree_entry_dup(&new_te, te);
3129 				if (err)
3130 					goto done;
3131 				err = insert_tree_entry(new_te, &paths);
3132 				if (err)
3133 					goto done;
3134 			}
3135 		}
3136 	}
3137 
3138 	/* Write new list of entries; deleted entries have been dropped. */
3139 	TAILQ_FOREACH(pe, &paths, entry) {
3140 		struct got_tree_entry *te = pe->data;
3141 		new_tree_entries.nentries++;
3142 		SIMPLEQ_INSERT_TAIL(&new_tree_entries.head, te, entry);
3143 	}
3144 	err = got_object_tree_create(new_tree_id, &new_tree_entries, repo);
3145 done:
3146 	got_object_tree_entries_close(&new_tree_entries);
3147 	got_pathlist_free(&paths);
3148 	return err;
3149 }
3150 
3151 static const struct got_error *
3152 update_fileindex_after_commit(struct got_pathlist_head *commitable_paths,
3153     struct got_object_id *new_base_commit_id, struct got_fileindex *fileindex)
3154 {
3155 	const struct got_error *err = NULL;
3156 	struct got_pathlist_entry *pe;
3157 
3158 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3159 		struct got_fileindex_entry *ie;
3160 		struct got_commitable *ct = pe->data;
3161 
3162 		ie = got_fileindex_entry_get(fileindex, pe->path);
3163 		if (ie) {
3164 			if (ct->status == GOT_STATUS_DELETE) {
3165 				got_fileindex_entry_remove(fileindex, ie);
3166 				got_fileindex_entry_free(ie);
3167 			} else
3168 				err = got_fileindex_entry_update(ie,
3169 				    ct->ondisk_path, ct->blob_id->sha1,
3170 				    new_base_commit_id->sha1, 1);
3171 		} else {
3172 			err = got_fileindex_entry_alloc(&ie,
3173 			    ct->ondisk_path, pe->path, ct->blob_id->sha1,
3174 			    new_base_commit_id->sha1);
3175 			if (err)
3176 				break;
3177 			err = got_fileindex_entry_add(fileindex, ie);
3178 			if (err)
3179 				break;
3180 		}
3181 	}
3182 	return err;
3183 }
3184 
3185 static const struct got_error *
3186 check_ct_out_of_date(struct got_commitable *ct, struct got_repository *repo,
3187 	struct got_object_id *head_commit_id)
3188 {
3189 	const struct got_error *err = NULL;
3190 	struct got_object_id *id_in_head = NULL, *id = NULL;
3191 	struct got_commit_object *commit = NULL;
3192 	char *path = NULL;
3193 	const char *ct_path = ct->in_repo_path;
3194 
3195 	while (ct_path[0] == '/')
3196 		ct_path++;
3197 
3198 	/*
3199 	 * Ensure that no modifications were made to files *and their parents*
3200 	 * in commits between the file's base commit and the branch head.
3201 	 *
3202 	 * Checking the parents is important for detecting conflicting tree
3203 	 * configurations (files or parent folders might have been moved,
3204 	 * deleted, added again, etc.). Such changes need to be merged with
3205 	 * local changes before a commit can occur.
3206 	 *
3207 	 * The implication is that the file's (parent) entry in the root
3208 	 * directory must have the same ID in all relevant commits.
3209 	 */
3210 	if (ct->status != GOT_STATUS_ADD) {
3211 		struct got_object_qid *pid;
3212 		char *slash;
3213 		struct got_object_id *root_entry_id = NULL;
3214 
3215 		/* Trivial case: base commit == head commit */
3216 		if (got_object_id_cmp(ct->base_commit_id, head_commit_id) == 0)
3217 			return NULL;
3218 
3219 		/* Compute the path to the root directory's entry. */
3220 		path = strdup(ct_path);
3221 		if (path == NULL) {
3222 			err = got_error_from_errno("strdup");
3223 			goto done;
3224 		}
3225 		slash = strchr(path, '/');
3226 		if (slash)
3227 			*slash = '\0';
3228 
3229 		err = got_object_open_as_commit(&commit, repo, head_commit_id);
3230 		if (err)
3231 			goto done;
3232 
3233 		err = got_object_id_by_path(&root_entry_id, repo,
3234 		    head_commit_id, path);
3235 		if (err)
3236 			goto done;
3237 
3238 		pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(commit));
3239 		while (pid) {
3240 			struct got_commit_object *pcommit;
3241 
3242 			err = got_object_id_by_path(&id, repo, pid->id, path);
3243 			if (err) {
3244 				if (err->code != GOT_ERR_NO_TREE_ENTRY)
3245 					goto done;
3246 				err = NULL;
3247 				break;
3248 			}
3249 
3250 			err = got_object_id_by_path(&id, repo, pid->id, path);
3251 			if (err)
3252 				goto done;
3253 
3254 			if (got_object_id_cmp(id, root_entry_id) != 0) {
3255 				err = got_error(GOT_ERR_COMMIT_OUT_OF_DATE);
3256 				break;
3257 			}
3258 
3259 			if (got_object_id_cmp(pid->id, ct->base_commit_id) == 0)
3260 				break; /* all relevant commits scanned */
3261 
3262 			err = got_object_open_as_commit(&pcommit, repo,
3263 			    pid->id);
3264 			if (err)
3265 				goto done;
3266 
3267 			got_object_commit_close(commit);
3268 			commit = pcommit;
3269 			pid = SIMPLEQ_FIRST(got_object_commit_get_parent_ids(
3270 			    commit));
3271 		}
3272 	} else {
3273 		/* Require that added files don't exist in the branch head. */
3274 		err = got_object_id_by_path(&id_in_head, repo, head_commit_id,
3275 		    ct_path);
3276 		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
3277 			goto done;
3278 		err = id_in_head ? got_error(GOT_ERR_COMMIT_OUT_OF_DATE) : NULL;
3279 	}
3280 done:
3281 	if (commit)
3282 		got_object_commit_close(commit);
3283 	free(id_in_head);
3284 	free(id);
3285 	free(path);
3286 	return err;
3287 }
3288 
3289 const struct got_error *
3290 commit_worktree(struct got_object_id **new_commit_id,
3291     struct got_pathlist_head *commitable_paths,
3292     struct got_object_id *head_commit_id, struct got_worktree *worktree,
3293     const char *ondisk_path, const char *author, const char *committer,
3294     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3295     got_worktree_status_cb status_cb, void *status_arg,
3296     struct got_repository *repo)
3297 {
3298 	const struct got_error *err = NULL, *unlockerr = NULL;
3299 	struct got_pathlist_entry *pe;
3300 	const char *head_ref_name = NULL;
3301 	struct got_commit_object *head_commit = NULL;
3302 	struct got_reference *head_ref2 = NULL;
3303 	struct got_object_id *head_commit_id2 = NULL;
3304 	struct got_tree_object *head_tree = NULL;
3305 	struct got_object_id *new_tree_id = NULL;
3306 	struct got_object_id_queue parent_ids;
3307 	struct got_object_qid *pid = NULL;
3308 	char *logmsg = NULL;
3309 
3310 	*new_commit_id = NULL;
3311 
3312 	SIMPLEQ_INIT(&parent_ids);
3313 
3314 	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
3315 	if (err)
3316 		goto done;
3317 
3318 	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
3319 	if (err)
3320 		goto done;
3321 
3322 	if (commit_msg_cb != NULL) {
3323 		err = commit_msg_cb(commitable_paths, &logmsg, commit_arg);
3324 		if (err)
3325 			goto done;
3326 	}
3327 
3328 	if (logmsg == NULL || strlen(logmsg) == 0) {
3329 		err = got_error(GOT_ERR_COMMIT_MSG_EMPTY);
3330 		goto done;
3331 	}
3332 
3333 	/* Create blobs from added and modified files and record their IDs. */
3334 	TAILQ_FOREACH(pe, commitable_paths, entry) {
3335 		struct got_commitable *ct = pe->data;
3336 		char *ondisk_path;
3337 
3338 		if (ct->status != GOT_STATUS_ADD &&
3339 		    ct->status != GOT_STATUS_MODIFY)
3340 			continue;
3341 
3342 		if (asprintf(&ondisk_path, "%s/%s",
3343 		    worktree->root_path, pe->path) == -1) {
3344 			err = got_error_from_errno("asprintf");
3345 			goto done;
3346 		}
3347 		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
3348 		free(ondisk_path);
3349 		if (err)
3350 			goto done;
3351 	}
3352 
3353 	/* Recursively write new tree objects. */
3354 	err = write_tree(&new_tree_id, head_tree, "/", commitable_paths,
3355 	    status_cb, status_arg, repo);
3356 	if (err)
3357 		goto done;
3358 
3359 	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
3360 	if (err)
3361 		goto done;
3362 	SIMPLEQ_INSERT_TAIL(&parent_ids, pid, entry);
3363 	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
3364 	    1, author, time(NULL), committer, time(NULL), logmsg, repo);
3365 	got_object_qid_free(pid);
3366 	if (logmsg != NULL)
3367 		free(logmsg);
3368 	if (err)
3369 		goto done;
3370 
3371 	/* Check if a concurrent commit to our branch has occurred. */
3372 	head_ref_name = got_worktree_get_head_ref_name(worktree);
3373 	if (head_ref_name == NULL) {
3374 		err = got_error_from_errno("got_worktree_get_head_ref_name");
3375 		goto done;
3376 	}
3377 	/* Lock the reference here to prevent concurrent modification. */
3378 	err = got_ref_open(&head_ref2, repo, head_ref_name, 1);
3379 	if (err)
3380 		goto done;
3381 	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
3382 	if (err)
3383 		goto done;
3384 	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
3385 		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
3386 		goto done;
3387 	}
3388 	/* Update branch head in repository. */
3389 	err = got_ref_change_ref(head_ref2, *new_commit_id);
3390 	if (err)
3391 		goto done;
3392 	err = got_ref_write(head_ref2, repo);
3393 	if (err)
3394 		goto done;
3395 
3396 	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
3397 	if (err)
3398 		goto done;
3399 
3400 	err = ref_base_commit(worktree, repo);
3401 	if (err)
3402 		goto done;
3403 done:
3404 	if (head_tree)
3405 		got_object_tree_close(head_tree);
3406 	if (head_commit)
3407 		got_object_commit_close(head_commit);
3408 	free(head_commit_id2);
3409 	if (head_ref2) {
3410 		unlockerr = got_ref_unlock(head_ref2);
3411 		if (unlockerr && err == NULL)
3412 			err = unlockerr;
3413 		got_ref_close(head_ref2);
3414 	}
3415 	return err;
3416 }
3417 
3418 const struct got_error *
3419 got_worktree_commit(struct got_object_id **new_commit_id,
3420     struct got_worktree *worktree, const char *ondisk_path,
3421     const char *author, const char *committer,
3422     got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
3423     got_worktree_status_cb status_cb, void *status_arg,
3424     struct got_repository *repo)
3425 {
3426 	const struct got_error *err = NULL, *unlockerr = NULL, *sync_err;
3427 	struct got_fileindex *fileindex = NULL;
3428 	char *fileindex_path = NULL, *relpath = NULL;
3429 	struct got_pathlist_head commitable_paths;
3430 	struct collect_commitables_arg cc_arg;
3431 	struct got_pathlist_entry *pe;
3432 	struct got_reference *head_ref = NULL;
3433 	struct got_object_id *head_commit_id = NULL;
3434 
3435 	*new_commit_id = NULL;
3436 
3437 	TAILQ_INIT(&commitable_paths);
3438 
3439 	err = lock_worktree(worktree, LOCK_EX);
3440 	if (err)
3441 		goto done;
3442 
3443 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3444 	if (err)
3445 		goto done;
3446 
3447 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3448 	if (err)
3449 		goto done;
3450 
3451 	if (ondisk_path) {
3452 		err = got_path_skip_common_ancestor(&relpath,
3453 		    worktree->root_path, ondisk_path);
3454 		if (err)
3455 			return err;
3456 	}
3457 
3458 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3459 	if (err)
3460 		goto done;
3461 
3462 	cc_arg.commitable_paths = &commitable_paths;
3463 	cc_arg.worktree = worktree;
3464 	cc_arg.repo = repo;
3465 	err = worktree_status(worktree, relpath ? relpath : "",
3466 	    fileindex, repo, collect_commitables, &cc_arg, NULL, NULL);
3467 	if (err)
3468 		goto done;
3469 
3470 	if (TAILQ_EMPTY(&commitable_paths)) {
3471 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3472 		goto done;
3473 	}
3474 
3475 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3476 		struct got_commitable *ct = pe->data;
3477 		err = check_ct_out_of_date(ct, repo, head_commit_id);
3478 		if (err)
3479 			goto done;
3480 	}
3481 
3482 	err = commit_worktree(new_commit_id, &commitable_paths,
3483 	    head_commit_id, worktree, ondisk_path, author, committer,
3484 	    commit_msg_cb, commit_arg, status_cb, status_arg, repo);
3485 	if (err)
3486 		goto done;
3487 
3488 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
3489 	    fileindex);
3490 	sync_err = sync_fileindex(fileindex, fileindex_path);
3491 	if (sync_err && err == NULL)
3492 		err = sync_err;
3493 done:
3494 	if (fileindex)
3495 		got_fileindex_free(fileindex);
3496 	free(fileindex_path);
3497 	free(relpath);
3498 	unlockerr = lock_worktree(worktree, LOCK_SH);
3499 	if (unlockerr && err == NULL)
3500 		err = unlockerr;
3501 	TAILQ_FOREACH(pe, &commitable_paths, entry) {
3502 		struct got_commitable *ct = pe->data;
3503 		free_commitable(ct);
3504 	}
3505 	got_pathlist_free(&commitable_paths);
3506 	return err;
3507 }
3508 
3509 const char *
3510 got_commitable_get_path(struct got_commitable *ct)
3511 {
3512 	return ct->path;
3513 }
3514 
3515 unsigned int
3516 got_commitable_get_status(struct got_commitable *ct)
3517 {
3518 	return ct->status;
3519 }
3520 
3521 struct check_rebase_ok_arg {
3522 	struct got_worktree *worktree;
3523 	struct got_repository *repo;
3524 	int rebase_in_progress;
3525 };
3526 
3527 static const struct got_error *
3528 check_rebase_ok(void *arg, struct got_fileindex_entry *ie)
3529 {
3530 	const struct got_error *err = NULL;
3531 	struct check_rebase_ok_arg *a = arg;
3532 	unsigned char status;
3533 	struct stat sb;
3534 	char *ondisk_path;
3535 
3536 	if (!a->rebase_in_progress) {
3537 		/* Reject rebase of a work tree with mixed base commits. */
3538 		if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
3539 		    SHA1_DIGEST_LENGTH))
3540 			return got_error(GOT_ERR_MIXED_COMMITS);
3541 	}
3542 
3543 	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
3544 	    == -1)
3545 		return got_error_from_errno("asprintf");
3546 
3547 	/* Reject rebase of a work tree with modified or conflicted files. */
3548 	err = get_file_status(&status, &sb, ie, ondisk_path, a->repo);
3549 	free(ondisk_path);
3550 	if (err)
3551 		return err;
3552 
3553 	if (a->rebase_in_progress) {
3554 		if (status == GOT_STATUS_CONFLICT)
3555 			return got_error(GOT_ERR_CONFLICTS);
3556 	} else if (status != GOT_STATUS_NO_CHANGE)
3557 		return got_error(GOT_ERR_MODIFIED);
3558 
3559 	return NULL;
3560 }
3561 
3562 const struct got_error *
3563 got_worktree_rebase_prepare(struct got_reference **new_base_branch_ref,
3564     struct got_reference **tmp_branch, struct got_worktree *worktree,
3565     struct got_reference *branch, struct got_repository *repo)
3566 {
3567 	const struct got_error *err = NULL;
3568 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
3569 	char *branch_ref_name = NULL;
3570 	struct got_fileindex *fileindex = NULL;
3571 	char *fileindex_path = NULL;
3572 	struct check_rebase_ok_arg ok_arg;
3573 	struct got_reference *wt_branch = NULL, *branch_ref = NULL;
3574 
3575 	*new_base_branch_ref = NULL;
3576 	*tmp_branch = NULL;
3577 
3578 	err = lock_worktree(worktree, LOCK_EX);
3579 	if (err)
3580 		return err;
3581 
3582 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3583 	if (err)
3584 		goto done;
3585 
3586 	ok_arg.worktree = worktree;
3587 	ok_arg.repo = repo;
3588 	ok_arg.rebase_in_progress = 0;
3589 	err = got_fileindex_for_each_entry_safe(fileindex, check_rebase_ok,
3590 	    &ok_arg);
3591 	if (err)
3592 		goto done;
3593 
3594 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3595 	if (err)
3596 		goto done;
3597 
3598 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3599 	if (err)
3600 		goto done;
3601 
3602 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3603 	if (err)
3604 		goto done;
3605 
3606 	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
3607 	    0);
3608 	if (err)
3609 		goto done;
3610 
3611 	err = got_ref_alloc_symref(new_base_branch_ref,
3612 	    new_base_branch_ref_name, wt_branch);
3613 	if (err)
3614 		goto done;
3615 	err = got_ref_write(*new_base_branch_ref, repo);
3616 	if (err)
3617 		goto done;
3618 
3619 	/* TODO Lock original branch's ref while rebasing? */
3620 
3621 	err = got_ref_alloc_symref(&branch_ref, branch_ref_name, branch);
3622 	if (err)
3623 		goto done;
3624 
3625 	err = got_ref_write(branch_ref, repo);
3626 	if (err)
3627 		goto done;
3628 
3629 	err = got_ref_alloc(tmp_branch, tmp_branch_name,
3630 	    worktree->base_commit_id);
3631 	if (err)
3632 		goto done;
3633 	err = got_ref_write(*tmp_branch, repo);
3634 	if (err)
3635 		goto done;
3636 
3637 	err = got_worktree_set_head_ref(worktree, *tmp_branch);
3638 	if (err)
3639 		goto done;
3640 done:
3641 	free(fileindex_path);
3642 	if (fileindex)
3643 		got_fileindex_free(fileindex);
3644 	free(tmp_branch_name);
3645 	free(new_base_branch_ref_name);
3646 	free(branch_ref_name);
3647 	if (branch_ref)
3648 		got_ref_close(branch_ref);
3649 	if (wt_branch)
3650 		got_ref_close(wt_branch);
3651 	if (err) {
3652 		if (*new_base_branch_ref) {
3653 			got_ref_close(*new_base_branch_ref);
3654 			*new_base_branch_ref = NULL;
3655 		}
3656 		if (*tmp_branch) {
3657 			got_ref_close(*tmp_branch);
3658 			*tmp_branch = NULL;
3659 		}
3660 		lock_worktree(worktree, LOCK_SH);
3661 	}
3662 	return err;
3663 }
3664 
3665 const struct got_error *
3666 got_worktree_rebase_continue(struct got_object_id **commit_id,
3667     struct got_reference **new_base_branch, struct got_reference **tmp_branch,
3668     struct got_reference **branch, struct got_worktree *worktree,
3669     struct got_repository *repo)
3670 {
3671 	const struct got_error *err;
3672 	char *commit_ref_name = NULL, *new_base_branch_ref_name = NULL;
3673 	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
3674 	struct got_reference *commit_ref = NULL, *branch_ref = NULL;
3675 
3676 	*commit_id = NULL;
3677 
3678 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3679 	if (err)
3680 		return err;
3681 
3682 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
3683 	if (err)
3684 		goto done;
3685 
3686 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3687 	if (err)
3688 		goto done;
3689 
3690 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
3691 	if (err)
3692 		goto done;
3693 
3694 	err = got_ref_open(&branch_ref, repo, branch_ref_name, 0);
3695 	if (err)
3696 		goto done;
3697 
3698 	err = got_ref_open(branch, repo,
3699 	    got_ref_get_symref_target(branch_ref), 0);
3700 	if (err)
3701 		goto done;
3702 
3703 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3704 	if (err)
3705 		goto done;
3706 
3707 	err = got_ref_resolve(commit_id, repo, commit_ref);
3708 	if (err)
3709 		goto done;
3710 
3711 	err = got_ref_open(new_base_branch, repo,
3712 	    new_base_branch_ref_name, 0);
3713 	if (err)
3714 		goto done;
3715 
3716 	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
3717 	if (err)
3718 		goto done;
3719 done:
3720 	free(commit_ref_name);
3721 	free(branch_ref_name);
3722 	if (commit_ref)
3723 		got_ref_close(commit_ref);
3724 	if (branch_ref)
3725 		got_ref_close(branch_ref);
3726 	if (err) {
3727 		free(*commit_id);
3728 		*commit_id = NULL;
3729 		if (*tmp_branch) {
3730 			got_ref_close(*tmp_branch);
3731 			*tmp_branch = NULL;
3732 		}
3733 		if (*new_base_branch) {
3734 			got_ref_close(*new_base_branch);
3735 			*new_base_branch = NULL;
3736 		}
3737 		if (*branch) {
3738 			got_ref_close(*branch);
3739 			*branch = NULL;
3740 		}
3741 	}
3742 	return err;
3743 }
3744 
3745 const struct got_error *
3746 got_worktree_rebase_in_progress(int *in_progress, struct got_worktree *worktree)
3747 {
3748 	const struct got_error *err;
3749 	char *tmp_branch_name = NULL;
3750 
3751 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
3752 	if (err)
3753 		return err;
3754 
3755 	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
3756 	free(tmp_branch_name);
3757 	return NULL;
3758 }
3759 
3760 static const struct got_error *
3761 collect_rebase_commit_msg(struct got_pathlist_head *commitable_paths,
3762     char **logmsg, void *arg)
3763 {
3764 	struct got_commit_object *commit = arg;
3765 
3766 	*logmsg = strdup(got_object_commit_get_logmsg(commit));
3767 	if (*logmsg == NULL)
3768 		return got_error_from_errno("strdup");
3769 
3770 	return NULL;
3771 }
3772 
3773 static const struct got_error *
3774 rebase_status(void *arg, unsigned char status, const char *path,
3775     struct got_object_id *blob_id, struct got_object_id *commit_id)
3776 {
3777 	return NULL;
3778 }
3779 
3780 struct collect_merged_paths_arg {
3781 	got_worktree_checkout_cb progress_cb;
3782 	void *progress_arg;
3783 	struct got_pathlist_head *merged_paths;
3784 };
3785 
3786 static const struct got_error *
3787 collect_merged_paths(void *arg, unsigned char status, const char *path)
3788 {
3789 	const struct got_error *err;
3790 	struct collect_merged_paths_arg *a = arg;
3791 	char *p;
3792 	struct got_pathlist_entry *new;
3793 
3794 	err = (*a->progress_cb)(a->progress_arg, status, path);
3795 	if (err)
3796 		return err;
3797 
3798 	if (status != GOT_STATUS_MERGE &&
3799 	    status != GOT_STATUS_ADD &&
3800 	    status != GOT_STATUS_DELETE &&
3801 	    status != GOT_STATUS_CONFLICT)
3802 		return NULL;
3803 
3804 	p = strdup(path);
3805 	if (p == NULL)
3806 		return got_error_from_errno("strdup");
3807 
3808 	err = got_pathlist_insert(&new, a->merged_paths, p, NULL);
3809 	if (err || new == NULL)
3810 		free(p);
3811 	return err;
3812 }
3813 
3814 void
3815 got_worktree_rebase_pathlist_free(struct got_pathlist_head *merged_paths)
3816 {
3817 	struct got_pathlist_entry *pe;
3818 
3819 	TAILQ_FOREACH(pe, merged_paths, entry)
3820 		free((char *)pe->path);
3821 
3822 	got_pathlist_free(merged_paths);
3823 }
3824 
3825 const struct got_error *
3826 got_worktree_rebase_merge_files(struct got_pathlist_head *merged_paths,
3827     struct got_worktree *worktree, struct got_object_id *parent_commit_id,
3828     struct got_object_id *commit_id, struct got_repository *repo,
3829     got_worktree_checkout_cb progress_cb, void *progress_arg,
3830     got_worktree_cancel_cb cancel_cb, void *cancel_arg)
3831 {
3832 	const struct got_error *err;
3833 	struct got_fileindex *fileindex;
3834 	char *fileindex_path, *commit_ref_name = NULL;
3835 	struct got_reference *commit_ref = NULL;
3836 	struct collect_merged_paths_arg cmp_arg;
3837 
3838 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
3839 
3840 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3841 	if (err)
3842 		return err;
3843 
3844 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3845 	if (err)
3846 		goto done;
3847 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3848 	if (err) {
3849 		if (err->code != GOT_ERR_NOT_REF)
3850 			goto done;
3851 		err = got_ref_alloc(&commit_ref, commit_ref_name, commit_id);
3852 		if (err)
3853 			goto done;
3854 		err = got_ref_write(commit_ref, repo);
3855 		if (err)
3856 			goto done;
3857 	} else {
3858 		struct got_object_id *stored_id;
3859 		int cmp;
3860 
3861 		err = got_ref_resolve(&stored_id, repo, commit_ref);
3862 		if (err)
3863 			goto done;
3864 		cmp = got_object_id_cmp(commit_id, stored_id);
3865 		free(stored_id);
3866 		if (cmp != 0) {
3867 			err = got_error(GOT_ERR_REBASE_COMMITID);
3868 			goto done;
3869 		}
3870 	}
3871 
3872 	cmp_arg.progress_cb = progress_cb;
3873 	cmp_arg.progress_arg = progress_arg;
3874 	cmp_arg.merged_paths = merged_paths;
3875 	err = merge_files(worktree, fileindex, fileindex_path,
3876 	    parent_commit_id, commit_id, repo, collect_merged_paths,
3877 	    &cmp_arg, cancel_cb, cancel_arg);
3878 done:
3879 	got_fileindex_free(fileindex);
3880 	free(fileindex_path);
3881 	if (commit_ref)
3882 		got_ref_close(commit_ref);
3883 	return err;
3884 }
3885 
3886 const struct got_error *
3887 got_worktree_rebase_commit(struct got_object_id **new_commit_id,
3888     struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
3889     struct got_reference *tmp_branch, struct got_commit_object *orig_commit,
3890     struct got_object_id *orig_commit_id, struct got_repository *repo)
3891 {
3892 	const struct got_error *err, *sync_err;
3893 	struct got_pathlist_head commitable_paths;
3894 	struct collect_commitables_arg cc_arg;
3895 	struct got_fileindex *fileindex = NULL;
3896 	char *fileindex_path = NULL, *commit_ref_name = NULL;
3897 	struct got_reference *head_ref = NULL;
3898 	struct got_object_id *head_commit_id = NULL;
3899 	struct got_reference *commit_ref = NULL;
3900 	struct got_object_id *commit_id = NULL;
3901 
3902 	TAILQ_INIT(&commitable_paths);
3903 	*new_commit_id = NULL;
3904 
3905 	/* Work tree is locked/unlocked during rebase preparation/teardown. */
3906 
3907 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
3908 	if (err)
3909 		return err;
3910 	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
3911 	if (err)
3912 		goto done;
3913 	err = got_ref_resolve(&commit_id, repo, commit_ref);
3914 	if (err)
3915 		goto done;
3916 	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
3917 		err = got_error(GOT_ERR_REBASE_COMMITID);
3918 		goto done;
3919 	}
3920 
3921 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
3922 	if (err)
3923 		goto done;
3924 
3925 	cc_arg.commitable_paths = &commitable_paths;
3926 	cc_arg.worktree = worktree;
3927 	cc_arg.repo = repo;
3928 	/*
3929 	 * If possible get the status of individual files directly to
3930 	 * avoid crawling the entire work tree once per rebased commit.
3931 	 * TODO: Ideally, merged_paths would contain a list of commitables
3932 	 * we could use so we could skip worktree_status() entirely.
3933 	 */
3934 	if (merged_paths) {
3935 		struct got_pathlist_entry *pe;
3936 		TAILQ_FOREACH(pe, merged_paths, entry) {
3937 			err = worktree_status(worktree, pe->path, fileindex,
3938 			    repo, collect_commitables, &cc_arg, NULL, NULL);
3939 			if (err)
3940 				goto done;
3941 		}
3942 	} else {
3943 		err = worktree_status(worktree, "", fileindex, repo,
3944 		    collect_commitables, &cc_arg, NULL, NULL);
3945 		if (err)
3946 			goto done;
3947 	}
3948 
3949 	if (TAILQ_EMPTY(&commitable_paths)) {
3950 		/* No-op change; commit will be elided. */
3951 		err = got_ref_delete(commit_ref, repo);
3952 		if (err)
3953 			goto done;
3954 		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
3955 		goto done;
3956 	}
3957 
3958 	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
3959 	if (err)
3960 		goto done;
3961 
3962 	err = got_ref_resolve(&head_commit_id, repo, head_ref);
3963 	if (err)
3964 		goto done;
3965 
3966 	err = commit_worktree(new_commit_id, &commitable_paths, head_commit_id,
3967 	    worktree, NULL, got_object_commit_get_author(orig_commit),
3968 	    got_object_commit_get_committer(orig_commit),
3969 	    collect_rebase_commit_msg, orig_commit,
3970 	    rebase_status, NULL, repo);
3971 	if (err)
3972 		goto done;
3973 
3974 	err = got_ref_change_ref(tmp_branch, *new_commit_id);
3975 	if (err)
3976 		goto done;
3977 
3978 	err = got_ref_delete(commit_ref, repo);
3979 	if (err)
3980 		goto done;
3981 
3982 	err = update_fileindex_after_commit(&commitable_paths, *new_commit_id,
3983 	    fileindex);
3984 	sync_err = sync_fileindex(fileindex, fileindex_path);
3985 	if (sync_err && err == NULL)
3986 		err = sync_err;
3987 done:
3988 	if (fileindex)
3989 		got_fileindex_free(fileindex);
3990 	free(fileindex_path);
3991 	free(commit_ref_name);
3992 	if (commit_ref)
3993 		got_ref_close(commit_ref);
3994 	free(head_commit_id);
3995 	if (head_ref)
3996 		got_ref_close(head_ref);
3997 	if (err) {
3998 		free(*new_commit_id);
3999 		*new_commit_id = NULL;
4000 	}
4001 	return err;
4002 }
4003 
4004 const struct got_error *
4005 got_worktree_rebase_postpone(struct got_worktree *worktree)
4006 {
4007 	return lock_worktree(worktree, LOCK_SH);
4008 }
4009 
4010 static const struct got_error *
4011 delete_ref(const char *name, struct got_repository *repo)
4012 {
4013 	const struct got_error *err;
4014 	struct got_reference *ref;
4015 
4016 	err = got_ref_open(&ref, repo, name, 0);
4017 	if (err) {
4018 		if (err->code == GOT_ERR_NOT_REF)
4019 			return NULL;
4020 		return err;
4021 	}
4022 
4023 	err = got_ref_delete(ref, repo);
4024 	got_ref_close(ref);
4025 	return err;
4026 }
4027 
4028 static const struct got_error *
4029 delete_rebase_refs(struct got_worktree *worktree, struct got_repository *repo)
4030 {
4031 	const struct got_error *err;
4032 	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
4033 	char *branch_ref_name = NULL, *commit_ref_name = NULL;
4034 
4035 	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
4036 	if (err)
4037 		goto done;
4038 	err = delete_ref(tmp_branch_name, repo);
4039 	if (err)
4040 		goto done;
4041 
4042 	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
4043 	if (err)
4044 		goto done;
4045 	err = delete_ref(new_base_branch_ref_name, repo);
4046 	if (err)
4047 		goto done;
4048 
4049 	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
4050 	if (err)
4051 		goto done;
4052 	err = delete_ref(branch_ref_name, repo);
4053 	if (err)
4054 		goto done;
4055 
4056 	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
4057 	if (err)
4058 		goto done;
4059 	err = delete_ref(commit_ref_name, repo);
4060 	if (err)
4061 		goto done;
4062 
4063 done:
4064 	free(tmp_branch_name);
4065 	free(new_base_branch_ref_name);
4066 	free(branch_ref_name);
4067 	free(commit_ref_name);
4068 	return err;
4069 }
4070 
4071 const struct got_error *
4072 got_worktree_rebase_complete(struct got_worktree *worktree,
4073     struct got_reference *new_base_branch, struct got_reference *tmp_branch,
4074     struct got_reference *rebased_branch,
4075     struct got_repository *repo)
4076 {
4077 	const struct got_error *err, *unlockerr;
4078 	struct got_object_id *new_head_commit_id = NULL;
4079 
4080 	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
4081 	if (err)
4082 		return err;
4083 
4084 	err = got_ref_change_ref(rebased_branch, new_head_commit_id);
4085 	if (err)
4086 		goto done;
4087 
4088 	err = got_ref_write(rebased_branch, repo);
4089 	if (err)
4090 		goto done;
4091 
4092 	err = got_worktree_set_head_ref(worktree, rebased_branch);
4093 	if (err)
4094 		goto done;
4095 
4096 	err = delete_rebase_refs(worktree, repo);
4097 done:
4098 	free(new_head_commit_id);
4099 	unlockerr = lock_worktree(worktree, LOCK_SH);
4100 	if (unlockerr && err == NULL)
4101 		err = unlockerr;
4102 	return err;
4103 }
4104 
4105 struct collect_revertible_paths_arg {
4106 	struct got_pathlist_head *revertible_paths;
4107 	struct got_worktree *worktree;
4108 };
4109 
4110 static const struct got_error *
4111 collect_revertible_paths(void *arg, unsigned char status, const char *relpath,
4112     struct got_object_id *blob_id, struct got_object_id *commit_id)
4113 {
4114 	struct collect_revertible_paths_arg *a = arg;
4115 	const struct got_error *err = NULL;
4116 	struct got_pathlist_entry *new = NULL;
4117 	char *path = NULL;
4118 
4119 	if (status != GOT_STATUS_ADD &&
4120 	    status != GOT_STATUS_DELETE &&
4121 	    status != GOT_STATUS_MODIFY &&
4122 	    status != GOT_STATUS_CONFLICT &&
4123 	    status != GOT_STATUS_MISSING)
4124 		return NULL;
4125 
4126 	if (asprintf(&path, "%s/%s", a->worktree->root_path, relpath) == -1)
4127 		return got_error_from_errno("asprintf");
4128 
4129 	err = got_pathlist_insert(&new, a->revertible_paths, path, NULL);
4130 	if (err || new == NULL)
4131 		free(path);
4132 	return err;
4133 }
4134 
4135 const struct got_error *
4136 got_worktree_rebase_abort(struct got_worktree *worktree,
4137     struct got_repository *repo, struct got_reference *new_base_branch,
4138      got_worktree_checkout_cb progress_cb, void *progress_arg)
4139 {
4140 	const struct got_error *err, *unlockerr, *sync_err;
4141 	struct got_reference *resolved = NULL;
4142 	struct got_object_id *commit_id = NULL;
4143 	struct got_fileindex *fileindex = NULL;
4144 	char *fileindex_path = NULL;
4145 	struct got_pathlist_head revertible_paths;
4146 	struct got_pathlist_entry *pe;
4147 	struct collect_revertible_paths_arg crp_arg;
4148 	struct got_object_id *tree_id = NULL;
4149 
4150 	TAILQ_INIT(&revertible_paths);
4151 
4152 	err = lock_worktree(worktree, LOCK_EX);
4153 	if (err)
4154 		return err;
4155 
4156 	err = got_ref_open(&resolved, repo,
4157 	    got_ref_get_symref_target(new_base_branch), 0);
4158 	if (err)
4159 		goto done;
4160 
4161 	err = got_worktree_set_head_ref(worktree, resolved);
4162 	if (err)
4163 		goto done;
4164 
4165 	/*
4166 	 * XXX commits to the base branch could have happened while
4167 	 * we were busy rebasing; should we store the original commit ID
4168 	 * when rebase begins and read it back here?
4169 	 */
4170 	err = got_ref_resolve(&commit_id, repo, resolved);
4171 	if (err)
4172 		goto done;
4173 
4174 	err = got_worktree_set_base_commit_id(worktree, repo, commit_id);
4175 	if (err)
4176 		goto done;
4177 
4178 	err = got_object_id_by_path(&tree_id, repo,
4179 	    worktree->base_commit_id, worktree->path_prefix);
4180 	if (err)
4181 		goto done;
4182 
4183 	err = delete_rebase_refs(worktree, repo);
4184 	if (err)
4185 		goto done;
4186 
4187 	err = open_fileindex(&fileindex, &fileindex_path, worktree);
4188 	if (err)
4189 		goto done;
4190 
4191 	crp_arg.revertible_paths = &revertible_paths;
4192 	crp_arg.worktree = worktree;
4193 	err = worktree_status(worktree, "", fileindex, repo,
4194 	    collect_revertible_paths, &crp_arg, NULL, NULL);
4195 	if (err)
4196 		goto done;
4197 
4198 	TAILQ_FOREACH(pe, &revertible_paths, entry) {
4199 		err = revert_file(worktree, fileindex, pe->path,
4200 		    progress_cb, progress_arg, repo);
4201 		if (err)
4202 			goto sync;
4203 	}
4204 
4205 	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
4206 	    repo, progress_cb, progress_arg, NULL, NULL);
4207 sync:
4208 	sync_err = sync_fileindex(fileindex, fileindex_path);
4209 	if (sync_err && err == NULL)
4210 		err = sync_err;
4211 done:
4212 	got_ref_close(resolved);
4213 	free(tree_id);
4214 	free(commit_id);
4215 	if (fileindex)
4216 		got_fileindex_free(fileindex);
4217 	free(fileindex_path);
4218 	TAILQ_FOREACH(pe, &revertible_paths, entry)
4219 		free((char *)pe->path);
4220 	got_pathlist_free(&revertible_paths);
4221 
4222 	unlockerr = lock_worktree(worktree, LOCK_SH);
4223 	if (unlockerr && err == NULL)
4224 		err = unlockerr;
4225 	return err;
4226 }