1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <sys/queue.h>
20 #include <sys/uio.h>
21 #include <sys/socket.h>
22 #include <sys/wait.h>
23 #include <sys/syslimits.h>
24 
25 #include <errno.h>
26 #include <fcntl.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <stdint.h>
31 #include <sha1.h>
32 #include <zlib.h>
33 #include <ctype.h>
34 #include <limits.h>
35 #include <imsg.h>
36 #include <time.h>
37 
38 #include "got_error.h"
39 #include "got_object.h"
40 #include "got_repository.h"
41 #include "got_opentemp.h"
42 
43 #include "got_lib_sha1.h"
44 #include "got_lib_delta.h"
45 #include "got_lib_pack.h"
46 #include "got_lib_path.h"
47 #include "got_lib_inflate.h"
48 #include "got_lib_object.h"
49 #include "got_lib_privsep.h"
50 #include "got_lib_object_idcache.h"
51 #include "got_lib_object_cache.h"
52 #include "got_lib_object_parse.h"
53 #include "got_lib_repository.h"
54 
55 #ifndef MIN
56 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
57 #endif
58 
59 int
60 got_object_id_cmp(struct got_object_id *id1, struct got_object_id *id2)
61 {
62 	return memcmp(id1->sha1, id2->sha1, SHA1_DIGEST_LENGTH);
63 }
64 
65 struct got_object_id *
66 got_object_id_dup(struct got_object_id *id1)
67 {
68 	struct got_object_id *id2;
69 
70 	id2 = malloc(sizeof(*id2));
71 	if (id2 == NULL)
72 		return NULL;
73 	memcpy(id2, id1, sizeof(*id2));
74 	return id2;
75 }
76 
77 struct got_object_id *
78 got_object_get_id(struct got_object *obj)
79 {
80 	return &obj->id;
81 }
82 
83 const struct got_error *
84 got_object_get_id_str(char **outbuf, struct got_object *obj)
85 {
86 	return got_object_id_str(outbuf, &obj->id);
87 }
88 
89 int
90 got_object_get_type(struct got_object *obj)
91 {
92 	switch (obj->type) {
93 	case GOT_OBJ_TYPE_COMMIT:
94 	case GOT_OBJ_TYPE_TREE:
95 	case GOT_OBJ_TYPE_BLOB:
96 	case GOT_OBJ_TYPE_TAG:
97 		return obj->type;
98 	default:
99 		abort();
100 		break;
101 	}
102 
103 	/* not reached */
104 	return 0;
105 }
106 
107 static const struct got_error *
108 object_path(char **path, struct got_object_id *id, struct got_repository *repo)
109 {
110 	const struct got_error *err = NULL;
111 	char *hex = NULL;
112 	char *path_objects = got_repo_get_path_objects(repo);
113 
114 	*path = NULL;
115 
116 	if (path_objects == NULL)
117 		return got_error_from_errno();
118 
119 	err = got_object_id_str(&hex, id);
120 	if (err)
121 		goto done;
122 
123 	if (asprintf(path, "%s/%.2x/%s", path_objects,
124 	    id->sha1[0], hex + 2) == -1)
125 		err = got_error_from_errno();
126 
127 done:
128 	free(hex);
129 	free(path_objects);
130 	return err;
131 }
132 
133 static const struct got_error *
134 open_loose_object(int *fd, struct got_object *obj, struct got_repository *repo)
135 {
136 	const struct got_error *err = NULL;
137 	char *path;
138 
139 	err = object_path(&path, &obj->id, repo);
140 	if (err)
141 		return err;
142 	*fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
143 	if (*fd == -1) {
144 		err = got_error_from_errno();
145 		goto done;
146 	}
147 done:
148 	free(path);
149 	return err;
150 }
151 
152 static const struct got_error *
153 get_packfile_path(char **path_packfile, struct got_packidx *packidx)
154 {
155 	size_t size;
156 
157 	/* Packfile path contains ".pack" instead of ".idx", so add one byte. */
158 	size = strlen(packidx->path_packidx) + 2;
159 	if (size < GOT_PACKFILE_NAMELEN + 1)
160 		return got_error(GOT_ERR_BAD_PATH);
161 
162 	*path_packfile = calloc(size, sizeof(**path_packfile));
163 	if (*path_packfile == NULL)
164 		return got_error_from_errno();
165 
166 	/* Copy up to and excluding ".idx". */
167 	if (strlcpy(*path_packfile, packidx->path_packidx,
168 	    size - strlen(GOT_PACKIDX_SUFFIX) - 1) >= size)
169 		return got_error(GOT_ERR_NO_SPACE);
170 
171 	if (strlcat(*path_packfile, GOT_PACKFILE_SUFFIX, size) >= size)
172 		return got_error(GOT_ERR_NO_SPACE);
173 
174 	return NULL;
175 }
176 
177 static const struct got_error *
178 open_packed_object(struct got_object **obj, struct got_object_id *id,
179     struct got_repository *repo)
180 {
181 	const struct got_error *err = NULL;
182 	struct got_pack *pack = NULL;
183 	struct got_packidx *packidx = NULL;
184 	int idx;
185 	char *path_packfile;
186 
187 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
188 	if (err)
189 		return err;
190 
191 	err = get_packfile_path(&path_packfile, packidx);
192 	if (err)
193 		return err;
194 
195 	pack = got_repo_get_cached_pack(repo, path_packfile);
196 	if (pack == NULL) {
197 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
198 		if (err)
199 			goto done;
200 	}
201 
202 	err = got_object_packed_read_privsep(obj, repo, pack, packidx, idx, id);
203 	if (err)
204 		goto done;
205 
206 	err = got_repo_cache_pack(NULL, repo, (*obj)->path_packfile, packidx);
207 done:
208 	free(path_packfile);
209 	return err;
210 }
211 
212 const struct got_error *
213 got_object_open(struct got_object **obj, struct got_repository *repo,
214     struct got_object_id *id)
215 {
216 	const struct got_error *err = NULL;
217 	char *path;
218 	int fd;
219 
220 	*obj = got_repo_get_cached_object(repo, id);
221 	if (*obj != NULL) {
222 		(*obj)->refcnt++;
223 		return NULL;
224 	}
225 
226 	err = open_packed_object(obj, id, repo);
227 	if (err && err->code != GOT_ERR_NO_OBJ)
228 		return err;
229 	if (*obj) {
230 		(*obj)->refcnt++;
231 		return got_repo_cache_object(repo, id, *obj);
232 	}
233 
234 	err = object_path(&path, id, repo);
235 	if (err)
236 		return err;
237 
238 	fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
239 	if (fd == -1) {
240 		if (errno == ENOENT)
241 			err = got_error(GOT_ERR_NO_OBJ);
242 		else
243 			err = got_error_from_errno();
244 		goto done;
245 	} else {
246 		err = got_object_read_header_privsep(obj, repo, fd);
247 		if (err)
248 			goto done;
249 		memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
250 	}
251 
252 	(*obj)->refcnt++;
253 	err = got_repo_cache_object(repo, id, *obj);
254 done:
255 	free(path);
256 	if (fd != -1)
257 		close(fd);
258 	return err;
259 
260 }
261 
262 const struct got_error *
263 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
264     const char *id_str)
265 {
266 	struct got_object_id id;
267 
268 	if (!got_parse_sha1_digest(id.sha1, id_str))
269 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
270 
271 	return got_object_open(obj, repo, &id);
272 }
273 
274 static const struct got_error *
275 open_commit(struct got_commit_object **commit,
276     struct got_repository *repo, struct got_object *obj, int check_cache)
277 {
278 	const struct got_error *err = NULL;
279 
280 	if (check_cache) {
281 		*commit = got_repo_get_cached_commit(repo, &obj->id);
282 		if (*commit != NULL) {
283 			(*commit)->refcnt++;
284 			return NULL;
285 		}
286 	} else
287 		*commit = NULL;
288 
289 	if (obj->type != GOT_OBJ_TYPE_COMMIT)
290 		return got_error(GOT_ERR_OBJ_TYPE);
291 
292 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
293 		struct got_pack *pack;
294 		pack = got_repo_get_cached_pack(repo, obj->path_packfile);
295 		if (pack == NULL) {
296 			err = got_repo_cache_pack(&pack, repo,
297 			    obj->path_packfile, NULL);
298 			if (err)
299 				return err;
300 		}
301 		err = got_object_read_packed_commit_privsep(commit, obj, pack);
302 	} else {
303 		int fd;
304 		err = open_loose_object(&fd, obj, repo);
305 		if (err)
306 			return err;
307 		err = got_object_read_commit_privsep(commit, obj, fd, repo);
308 		close(fd);
309 	}
310 
311 	if (err == NULL) {
312 		(*commit)->refcnt++;
313 		err = got_repo_cache_commit(repo, &obj->id, *commit);
314 	}
315 
316 	return err;
317 }
318 
319 const struct got_error *
320 got_object_open_as_commit(struct got_commit_object **commit,
321     struct got_repository *repo, struct got_object_id *id)
322 {
323 	const struct got_error *err;
324 	struct got_object *obj;
325 
326 	*commit = got_repo_get_cached_commit(repo, id);
327 	if (*commit != NULL) {
328 		(*commit)->refcnt++;
329 		return NULL;
330 	}
331 
332 	err = got_object_open(&obj, repo, id);
333 	if (err)
334 		return err;
335 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_COMMIT) {
336 		err = got_error(GOT_ERR_OBJ_TYPE);
337 		goto done;
338 	}
339 
340 	err = open_commit(commit, repo, obj, 0);
341 done:
342 	got_object_close(obj);
343 	return err;
344 }
345 
346 const struct got_error *
347 got_object_commit_open(struct got_commit_object **commit,
348     struct got_repository *repo, struct got_object *obj)
349 {
350 	return open_commit(commit, repo, obj, 1);
351 }
352 
353 const struct got_error *
354 got_object_qid_alloc(struct got_object_qid **qid, struct got_object_id *id)
355 {
356 	const struct got_error *err = NULL;
357 
358 	*qid = calloc(1, sizeof(**qid));
359 	if (*qid == NULL)
360 		return got_error_from_errno();
361 
362 	(*qid)->id = got_object_id_dup(id);
363 	if ((*qid)->id == NULL) {
364 		err = got_error_from_errno();
365 		got_object_qid_free(*qid);
366 		*qid = NULL;
367 		return err;
368 	}
369 
370 	return NULL;
371 }
372 
373 static const struct got_error *
374 open_tree(struct got_tree_object **tree,
375     struct got_repository *repo, struct got_object *obj, int check_cache)
376 {
377 	const struct got_error *err = NULL;
378 
379 	if (check_cache) {
380 		*tree = got_repo_get_cached_tree(repo, &obj->id);
381 		if (*tree != NULL) {
382 			(*tree)->refcnt++;
383 			return NULL;
384 		}
385 	} else
386 		*tree = NULL;
387 
388 	if (obj->type != GOT_OBJ_TYPE_TREE)
389 		return got_error(GOT_ERR_OBJ_TYPE);
390 
391 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
392 		struct got_pack *pack;
393 		pack = got_repo_get_cached_pack(repo, obj->path_packfile);
394 		if (pack == NULL) {
395 			err = got_repo_cache_pack(&pack, repo,
396 			    obj->path_packfile, NULL);
397 			if (err)
398 				return err;
399 		}
400 		err = got_object_read_packed_tree_privsep(tree, obj, pack);
401 	} else {
402 		int fd;
403 		err = open_loose_object(&fd, obj, repo);
404 		if (err)
405 			return err;
406 		err = got_object_read_tree_privsep(tree, obj, fd, repo);
407 		close(fd);
408 	}
409 
410 	if (err == NULL) {
411 		(*tree)->refcnt++;
412 		err = got_repo_cache_tree(repo, &obj->id, *tree);
413 	}
414 
415 	return err;
416 }
417 
418 const struct got_error *
419 got_object_open_as_tree(struct got_tree_object **tree,
420     struct got_repository *repo, struct got_object_id *id)
421 {
422 	const struct got_error *err;
423 	struct got_object *obj;
424 
425 	*tree = got_repo_get_cached_tree(repo, id);
426 	if (*tree != NULL) {
427 		(*tree)->refcnt++;
428 		return NULL;
429 	}
430 
431 	err = got_object_open(&obj, repo, id);
432 	if (err)
433 		return err;
434 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_TREE) {
435 		err = got_error(GOT_ERR_OBJ_TYPE);
436 		goto done;
437 	}
438 
439 	err = open_tree(tree, repo, obj, 0);
440 done:
441 	got_object_close(obj);
442 	return err;
443 }
444 
445 const struct got_error *
446 got_object_tree_open(struct got_tree_object **tree,
447     struct got_repository *repo, struct got_object *obj)
448 {
449 	return open_tree(tree, repo, obj, 1);
450 }
451 
452 const struct got_tree_entries *
453 got_object_tree_get_entries(struct got_tree_object *tree)
454 {
455 	return &tree->entries;
456 }
457 
458 static const struct got_error *
459 read_packed_blob_privsep(size_t *size, int outfd, struct got_object *obj,
460     struct got_pack *pack)
461 {
462 	const struct got_error *err = NULL;
463 	int outfd_child;
464 	int basefd, accumfd; /* temporary files for delta application */
465 
466 	basefd = got_opentempfd();
467 	if (basefd == -1)
468 		return got_error_from_errno();
469 	accumfd = got_opentempfd();
470 	if (accumfd == -1)
471 		return got_error_from_errno();
472 
473 	outfd_child = dup(outfd);
474 	if (outfd_child == -1)
475 		return got_error_from_errno();
476 
477 	err = got_privsep_send_obj_req(pack->privsep_child->ibuf, -1, obj);
478 	if (err)
479 		return err;
480 
481 	err = got_privsep_send_blob_outfd(pack->privsep_child->ibuf,
482 	    outfd_child);
483 	if (err) {
484 		close(outfd_child);
485 		return err;
486 	}
487 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
488 	    basefd);
489 	if (err) {
490 		close(basefd);
491 		close(accumfd);
492 		close(outfd_child);
493 		return err;
494 	}
495 
496 	err = got_privsep_send_tmpfd(pack->privsep_child->ibuf,
497 	    accumfd);
498 	if (err) {
499 		close(accumfd);
500 		close(outfd_child);
501 		return err;
502 	}
503 
504 	err = got_privsep_recv_blob(size, pack->privsep_child->ibuf);
505 	if (err)
506 		return err;
507 
508 	if (lseek(outfd, SEEK_SET, 0) == -1)
509 		err = got_error_from_errno();
510 
511 	return err;
512 }
513 
514 const struct got_error *
515 got_object_blob_open(struct got_blob_object **blob,
516     struct got_repository *repo, struct got_object *obj, size_t blocksize)
517 {
518 	const struct got_error *err = NULL;
519 	int outfd;
520 	size_t size;
521 	struct stat sb;
522 
523 	if (obj->type != GOT_OBJ_TYPE_BLOB)
524 		return got_error(GOT_ERR_OBJ_TYPE);
525 
526 	if (blocksize < obj->hdrlen)
527 		return got_error(GOT_ERR_NO_SPACE);
528 
529 	*blob = calloc(1, sizeof(**blob));
530 	if (*blob == NULL)
531 		return got_error_from_errno();
532 
533 	outfd = got_opentempfd();
534 	if (outfd == -1)
535 		return got_error_from_errno();
536 
537 	(*blob)->read_buf = malloc(blocksize);
538 	if ((*blob)->read_buf == NULL) {
539 		err = got_error_from_errno();
540 		goto done;
541 	}
542 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
543 		struct got_pack *pack;
544 		pack = got_repo_get_cached_pack(repo, obj->path_packfile);
545 		if (pack == NULL) {
546 			err = got_repo_cache_pack(&pack, repo,
547 			    obj->path_packfile, NULL);
548 			if (err)
549 				goto done;
550 		}
551 		err = read_packed_blob_privsep(&size, outfd, obj, pack);
552 		if (err)
553 			goto done;
554 		obj->size = size;
555 	} else {
556 		int infd;
557 
558 		err = open_loose_object(&infd, obj, repo);
559 		if (err)
560 			goto done;
561 
562 		err = got_object_read_blob_privsep(&size, outfd, infd, repo);
563 		close(infd);
564 		if (err)
565 			goto done;
566 
567 		if (size != obj->hdrlen + obj->size) {
568 			err = got_error(GOT_ERR_PRIVSEP_LEN);
569 			goto done;
570 		}
571 	}
572 
573 	if (fstat(outfd, &sb) == -1) {
574 		err = got_error_from_errno();
575 		goto done;
576 	}
577 
578 	if (sb.st_size != obj->hdrlen + obj->size) {
579 		err = got_error(GOT_ERR_PRIVSEP_LEN);
580 		goto done;
581 	}
582 
583 	(*blob)->f = fdopen(outfd, "rb");
584 	if ((*blob)->f == NULL) {
585 		err = got_error_from_errno();
586 		close(outfd);
587 		goto done;
588 	}
589 
590 	(*blob)->hdrlen = obj->hdrlen;
591 	(*blob)->blocksize = blocksize;
592 	memcpy(&(*blob)->id.sha1, obj->id.sha1, SHA1_DIGEST_LENGTH);
593 
594 done:
595 	if (err) {
596 		if (*blob) {
597 			if ((*blob)->f)
598 				fclose((*blob)->f);
599 			free((*blob)->read_buf);
600 			free(*blob);
601 			*blob = NULL;
602 		} else if (outfd != -1)
603 			close(outfd);
604 	}
605 	return err;
606 }
607 
608 const struct got_error *
609 got_object_open_as_blob(struct got_blob_object **blob,
610     struct got_repository *repo, struct got_object_id *id,
611     size_t blocksize)
612 {
613 	const struct got_error *err;
614 	struct got_object *obj;
615 
616 	*blob = NULL;
617 
618 	err = got_object_open(&obj, repo, id);
619 	if (err)
620 		return err;
621 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_BLOB) {
622 		err = got_error(GOT_ERR_OBJ_TYPE);
623 		goto done;
624 	}
625 
626 	err = got_object_blob_open(blob, repo, obj, blocksize);
627 done:
628 	got_object_close(obj);
629 	return err;
630 }
631 
632 void
633 got_object_blob_close(struct got_blob_object *blob)
634 {
635 	free(blob->read_buf);
636 	fclose(blob->f);
637 	free(blob);
638 }
639 
640 char *
641 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
642 {
643 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
644 }
645 
646 size_t
647 got_object_blob_get_hdrlen(struct got_blob_object *blob)
648 {
649 	return blob->hdrlen;
650 }
651 
652 const uint8_t *
653 got_object_blob_get_read_buf(struct got_blob_object *blob)
654 {
655 	return blob->read_buf;
656 }
657 
658 const struct got_error *
659 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
660 {
661 	size_t n;
662 
663 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
664 	if (n == 0 && ferror(blob->f))
665 		return got_ferror(blob->f, GOT_ERR_IO);
666 	*outlenp = n;
667 	return NULL;
668 }
669 
670 const struct got_error *
671 got_object_blob_dump_to_file(size_t *total_len, size_t *nlines,
672     FILE *outfile, struct got_blob_object *blob)
673 {
674 	const struct got_error *err = NULL;
675 	size_t len, hdrlen;
676 	const uint8_t *buf;
677 	int i;
678 
679 	if (total_len)
680 		*total_len = 0;
681 	if (nlines)
682 		*nlines = 0;
683 
684 	hdrlen = got_object_blob_get_hdrlen(blob);
685 	do {
686 		err = got_object_blob_read_block(&len, blob);
687 		if (err)
688 			return err;
689 		if (len == 0)
690 			break;
691 		if (total_len)
692 			*total_len += len;
693 		buf = got_object_blob_get_read_buf(blob);
694 		if (nlines) {
695 			for (i = 0; i < len; i++) {
696 				if (buf[i] == '\n')
697 					(*nlines)++;
698 			}
699 		}
700 		/* Skip blob object header first time around. */
701 		fwrite(buf + hdrlen, len - hdrlen, 1, outfile);
702 		hdrlen = 0;
703 	} while (len != 0);
704 
705 	fflush(outfile);
706 	rewind(outfile);
707 
708 	return NULL;
709 }
710 
711 static struct got_tree_entry *
712 find_entry_by_name(struct got_tree_object *tree, const char *name, size_t len)
713 {
714 	struct got_tree_entry *te;
715 
716 	SIMPLEQ_FOREACH(te, &tree->entries.head, entry) {
717 		if (strncmp(te->name, name, len) == 0 && te->name[len] == '\0')
718 			return te;
719 	}
720 	return NULL;
721 }
722 
723 const struct got_error *
724 got_object_id_by_path(struct got_object_id **id, struct got_repository *repo,
725     struct got_object_id *commit_id, const char *path)
726 {
727 	const struct got_error *err = NULL;
728 	struct got_commit_object *commit = NULL;
729 	struct got_tree_object *tree = NULL;
730 	struct got_tree_entry *te = NULL;
731 	const char *seg, *s;
732 	size_t seglen, len = strlen(path);
733 
734 	*id = NULL;
735 
736 	/* We are expecting an absolute in-repository path. */
737 	if (path[0] != '/')
738 		return got_error(GOT_ERR_NOT_ABSPATH);
739 
740 	err = got_object_open_as_commit(&commit, repo, commit_id);
741 	if (err)
742 		goto done;
743 
744 	/* Handle opening of root of commit's tree. */
745 	if (path[1] == '\0') {
746 		*id = got_object_id_dup(commit->tree_id);
747 		if (*id == NULL)
748 			err = got_error_from_errno();
749 		goto done;
750 	}
751 
752 	err = got_object_open_as_tree(&tree, repo, commit->tree_id);
753 	if (err)
754 		goto done;
755 
756 	s = path;
757 	s++; /* skip leading '/' */
758 	len--;
759 	seg = s;
760 	seglen = 0;
761 	while (len > 0) {
762 		struct got_tree_object *next_tree;
763 
764 		if (*s != '/') {
765 			s++;
766 			len--;
767 			seglen++;
768 			if (*s)
769 				continue;
770 		}
771 
772 		te = find_entry_by_name(tree, seg, seglen);
773 		if (te == NULL) {
774 			err = got_error(GOT_ERR_NO_OBJ);
775 			goto done;
776 		}
777 
778 		if (len == 0)
779 			break;
780 
781 		seg = s + 1;
782 		seglen = 0;
783 		s++;
784 		len--;
785 		if (*s) {
786 			err = got_object_open_as_tree(&next_tree, repo,
787 			    te->id);
788 			te = NULL;
789 			if (err)
790 				goto done;
791 			got_object_tree_close(tree);
792 			tree = next_tree;
793 		}
794 	}
795 
796 	if (te) {
797 		*id = got_object_id_dup(te->id);
798 		if (*id == NULL)
799 			return got_error_from_errno();
800 	} else
801 		err = got_error(GOT_ERR_NO_OBJ);
802 done:
803 	if (commit)
804 		got_object_commit_close(commit);
805 	if (tree)
806 		got_object_tree_close(tree);
807 	return err;
808 }
809 
810 const struct got_error *
811 got_object_tree_path_changed(int *changed,
812     struct got_tree_object *tree01, struct got_tree_object *tree02,
813     const char *path, struct got_repository *repo)
814 {
815 	const struct got_error *err = NULL;
816 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
817 	struct got_tree_entry *te1 = NULL, *te2 = NULL;
818 	const char *seg, *s;
819 	size_t seglen, len = strlen(path);
820 
821 	*changed = 0;
822 
823 	/* We are expecting an absolute in-repository path. */
824 	if (path[0] != '/')
825 		return got_error(GOT_ERR_NOT_ABSPATH);
826 
827 	/* We not do support comparing the root path. */
828 	if (path[1] == '\0')
829 		return got_error(GOT_ERR_BAD_PATH);
830 
831 	tree1 = tree01;
832 	tree2 = tree02;
833 	s = path;
834 	s++; /* skip leading '/' */
835 	len--;
836 	seg = s;
837 	seglen = 0;
838 	while (len > 0) {
839 		struct got_tree_object *next_tree1, *next_tree2;
840 
841 		if (*s != '/') {
842 			s++;
843 			len--;
844 			seglen++;
845 			if (*s)
846 				continue;
847 		}
848 
849 		te1 = find_entry_by_name(tree1, seg, seglen);
850 		if (te1 == NULL) {
851 			err = got_error(GOT_ERR_NO_OBJ);
852 			goto done;
853 		}
854 
855 		te2 = find_entry_by_name(tree2, seg, seglen);
856 		if (te2 == NULL) {
857 			*changed = 1;
858 			goto done;
859 		}
860 
861 		if (te1->mode != te2->mode) {
862 			*changed = 1;
863 			goto done;
864 		}
865 
866 		if (got_object_id_cmp(te1->id, te2->id) == 0) {
867 			*changed = 0;
868 			goto done;
869 		}
870 
871 		if (len == 0) { /* final path element */
872 			*changed = 1;
873 			goto done;
874 		}
875 
876 		seg = s + 1;
877 		s++;
878 		len--;
879 		seglen = 0;
880 		if (*s) {
881 			err = got_object_open_as_tree(&next_tree1, repo,
882 			    te1->id);
883 			te1 = NULL;
884 			if (err)
885 				goto done;
886 			if (tree1 != tree01)
887 				got_object_tree_close(tree1);
888 			tree1 = next_tree1;
889 
890 			err = got_object_open_as_tree(&next_tree2, repo,
891 			    te2->id);
892 			te2 = NULL;
893 			if (err)
894 				goto done;
895 			if (tree2 != tree02)
896 				got_object_tree_close(tree2);
897 			tree2 = next_tree2;
898 		}
899 	}
900 done:
901 	if (tree1 && tree1 != tree01)
902 		got_object_tree_close(tree1);
903 	if (tree2 && tree2 != tree02)
904 		got_object_tree_close(tree2);
905 	return err;
906 }