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Date:: Tue Jul 10 11:17:00 2018 UTC
Message:: implement incremental blame display for tog
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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 
24 #include <errno.h>
25 #include <fcntl.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <stdint.h>
30 #include <sha1.h>
31 #include <zlib.h>
32 #include <ctype.h>
33 #include <limits.h>
34 #include <imsg.h>
35 #include <time.h>
36 
37 #include "got_error.h"
38 #include "got_object.h"
39 #include "got_repository.h"
40 #include "got_opentemp.h"
41 
42 #include "got_lib_sha1.h"
43 #include "got_lib_delta.h"
44 #include "got_lib_pack.h"
45 #include "got_lib_path.h"
46 #include "got_lib_inflate.h"
47 #include "got_lib_object.h"
48 #include "got_lib_privsep.h"
49 #include "got_lib_repository.h"
50 
51 #ifndef MIN
52 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
53 #endif
54 
55 #ifndef nitems
56 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
57 #endif
58 
59 #define GOT_OBJ_TAG_COMMIT	"commit"
60 #define GOT_OBJ_TAG_TREE	"tree"
61 #define GOT_OBJ_TAG_BLOB	"blob"
62 
63 #define GOT_COMMIT_TAG_TREE		"tree "
64 #define GOT_COMMIT_TAG_PARENT		"parent "
65 #define GOT_COMMIT_TAG_AUTHOR		"author "
66 #define GOT_COMMIT_TAG_COMMITTER	"committer "
67 
68 const struct got_error *
69 got_object_id_str(char **outbuf, struct got_object_id *id)
70 {
71 	static const size_t len = SHA1_DIGEST_STRING_LENGTH;
72 
73 	*outbuf = calloc(1, len);
74 	if (*outbuf == NULL)
75 		return got_error_from_errno();
76 
77 	if (got_sha1_digest_to_str(id->sha1, *outbuf, len) == NULL) {
78 		free(*outbuf);
79 		*outbuf = NULL;
80 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
81 	}
82 
83 	return NULL;
84 }
85 
86 int
87 got_object_id_cmp(struct got_object_id *id1, struct got_object_id *id2)
88 {
89 	return memcmp(id1->sha1, id2->sha1, SHA1_DIGEST_LENGTH);
90 }
91 
92 struct got_object_id *
93 got_object_id_dup(struct got_object_id *id1)
94 {
95 	struct got_object_id *id2;
96 
97 	id2 = malloc(sizeof(*id2));
98 	if (id2 == NULL)
99 		return NULL;
100 	memcpy(id2, id1, sizeof(*id2));
101 	return id2;
102 }
103 
104 struct got_object_id *
105 got_object_get_id(struct got_object *obj)
106 {
107 	return got_object_id_dup(&obj->id);
108 }
109 
110 const struct got_error *
111 got_object_get_id_str(char **outbuf, struct got_object *obj)
112 {
113 	return got_object_id_str(outbuf, &obj->id);
114 }
115 
116 int
117 got_object_get_type(struct got_object *obj)
118 {
119 	switch (obj->type) {
120 	case GOT_OBJ_TYPE_COMMIT:
121 	case GOT_OBJ_TYPE_TREE:
122 	case GOT_OBJ_TYPE_BLOB:
123 	case GOT_OBJ_TYPE_TAG:
124 		return obj->type;
125 	default:
126 		abort();
127 		break;
128 	}
129 
130 	/* not reached */
131 	return 0;
132 }
133 
134 static const struct got_error *
135 parse_object_header(struct got_object **obj, char *buf, size_t len)
136 {
137 	const char *obj_tags[] = {
138 		GOT_OBJ_TAG_COMMIT,
139 		GOT_OBJ_TAG_TREE,
140 		GOT_OBJ_TAG_BLOB
141 	};
142 	const int obj_types[] = {
143 		GOT_OBJ_TYPE_COMMIT,
144 		GOT_OBJ_TYPE_TREE,
145 		GOT_OBJ_TYPE_BLOB,
146 	};
147 	int type = 0;
148 	size_t size = 0, hdrlen = 0;
149 	int i;
150 	char *p = strchr(buf, '\0');
151 
152 	if (p == NULL)
153 		return got_error(GOT_ERR_BAD_OBJ_HDR);
154 
155 	hdrlen = strlen(buf) + 1 /* '\0' */;
156 
157 	for (i = 0; i < nitems(obj_tags); i++) {
158 		const char *tag = obj_tags[i];
159 		size_t tlen = strlen(tag);
160 		const char *errstr;
161 
162 		if (strncmp(buf, tag, tlen) != 0)
163 			continue;
164 
165 		type = obj_types[i];
166 		if (len <= tlen)
167 			return got_error(GOT_ERR_BAD_OBJ_HDR);
168 		size = strtonum(buf + tlen, 0, LONG_MAX, &errstr);
169 		if (errstr != NULL)
170 			return got_error(GOT_ERR_BAD_OBJ_HDR);
171 		break;
172 	}
173 
174 	if (type == 0)
175 		return got_error(GOT_ERR_BAD_OBJ_HDR);
176 
177 	*obj = calloc(1, sizeof(**obj));
178 	if (*obj == NULL)
179 		return got_error_from_errno();
180 	(*obj)->type = type;
181 	(*obj)->hdrlen = hdrlen;
182 	(*obj)->size = size;
183 	return NULL;
184 }
185 
186 static const struct got_error *
187 read_object_header(struct got_object **obj, int fd)
188 {
189 	const struct got_error *err;
190 	struct got_zstream_buf zb;
191 	char *buf;
192 	const size_t zbsize = 64;
193 	size_t outlen, totlen;
194 	int i;
195 
196 	buf = calloc(zbsize, sizeof(char));
197 	if (buf == NULL)
198 		return got_error_from_errno();
199 
200 	err = got_inflate_init(&zb, NULL, zbsize);
201 	if (err)
202 		return err;
203 
204 	i = 0;
205 	totlen = 0;
206 	do {
207 		err = got_inflate_read_fd(&zb, fd, &outlen);
208 		if (err)
209 			goto done;
210 		if (strchr(zb.outbuf, '\0') == NULL) {
211 			buf = recallocarray(buf, 1 + i, 2 + i, zbsize);
212 			if (buf == NULL) {
213 				err = got_error_from_errno();
214 				goto done;
215 			}
216 		}
217 		memcpy(buf + totlen, zb.outbuf, outlen);
218 		totlen += outlen;
219 		i++;
220 	} while (strchr(zb.outbuf, '\0') == NULL);
221 
222 	err = parse_object_header(obj, buf, totlen);
223 done:
224 	got_inflate_end(&zb);
225 	return err;
226 }
227 
228 static void
229 read_object_header_privsep_child(int obj_fd, int imsg_fds[2])
230 {
231 	const struct got_error *err = NULL;
232 	struct got_object *obj = NULL;
233 	struct imsgbuf ibuf;
234 	int status = 0;
235 
236 	setproctitle("read object header");
237 	close(imsg_fds[0]);
238 	imsg_init(&ibuf, imsg_fds[1]);
239 
240 	/* revoke access to most system calls */
241 	if (pledge("stdio", NULL) == -1) {
242 		err = got_error_from_errno();
243 		goto done;
244 	}
245 
246 	err = read_object_header(&obj, obj_fd);
247 	if (err)
248 		goto done;
249 
250 	err = got_privsep_send_obj(&ibuf, obj, 0);
251 done:
252 	if (obj)
253 		got_object_close(obj);
254 	if (err) {
255 		got_privsep_send_error(&ibuf, err);
256 		status = 1;
257 	}
258 	close(obj_fd);
259 	imsg_clear(&ibuf);
260 	close(imsg_fds[1]);
261 	_exit(status);
262 }
263 
264 static const struct got_error *
265 wait_for_child(pid_t pid)
266 {
267 	int child_status;
268 
269 	waitpid(pid, &child_status, 0);
270 
271 	if (!WIFEXITED(child_status))
272 		return got_error(GOT_ERR_PRIVSEP_DIED);
273 
274 	if (WEXITSTATUS(child_status) != 0)
275 		return got_error(GOT_ERR_PRIVSEP_EXIT);
276 
277 	return NULL;
278 }
279 
280 static const struct got_error *
281 read_object_header_privsep(struct got_object **obj, int fd)
282 {
283 	struct imsgbuf parent_ibuf;
284 	int imsg_fds[2];
285 	const struct got_error *err = NULL, *err_child = NULL;
286 	pid_t pid;
287 
288 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
289 		return got_error_from_errno();
290 
291 	pid = fork();
292 	if (pid == -1)
293 		return got_error_from_errno();
294 	else if (pid == 0) {
295 		read_object_header_privsep_child(fd, imsg_fds);
296 		/* not reached */
297 	}
298 
299 	close(imsg_fds[1]);
300 	imsg_init(&parent_ibuf, imsg_fds[0]);
301 	err = got_privsep_recv_obj(obj, &parent_ibuf);
302 	imsg_clear(&parent_ibuf);
303 	err_child = wait_for_child(pid);
304 	close(imsg_fds[0]);
305 	return err ? err : err_child;
306 }
307 
308 static const struct got_error *
309 object_path(char **path, struct got_object_id *id, struct got_repository *repo)
310 {
311 	const struct got_error *err = NULL;
312 	char *hex;
313 	char *path_objects = got_repo_get_path_objects(repo);
314 
315 	*path = NULL;
316 
317 	if (path_objects == NULL)
318 		return got_error_from_errno();
319 
320 	err = got_object_id_str(&hex, id);
321 	if (err)
322 		return err;
323 
324 	if (asprintf(path, "%s/%.2x/%s", path_objects,
325 	    id->sha1[0], hex + 2) == -1)
326 		err = got_error_from_errno();
327 
328 	free(hex);
329 	free(path_objects);
330 	return err;
331 }
332 
333 static const struct got_error *
334 open_loose_object(int *fd, struct got_object *obj, struct got_repository *repo)
335 {
336 	const struct got_error *err = NULL;
337 	char *path;
338 
339 	err = object_path(&path, &obj->id, repo);
340 	if (err)
341 		return err;
342 	*fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
343 	if (*fd == -1) {
344 		err = got_error_from_errno();
345 		goto done;
346 	}
347 done:
348 	free(path);
349 	return err;
350 }
351 
352 const struct got_error *
353 got_object_open(struct got_object **obj, struct got_repository *repo,
354     struct got_object_id *id)
355 {
356 	const struct got_error *err = NULL;
357 	char *path;
358 	int fd;
359 
360 	*obj = got_repo_get_cached_object(repo, id);
361 	if (*obj != NULL) {
362 		(*obj)->refcnt++;
363 		return NULL;
364 	}
365 
366 	err = object_path(&path, id, repo);
367 	if (err)
368 		return err;
369 
370 	fd = open(path, O_RDONLY | O_NOFOLLOW, GOT_DEFAULT_FILE_MODE);
371 	if (fd == -1) {
372 		if (errno != ENOENT) {
373 			err = got_error_from_errno();
374 			goto done;
375 		}
376 		err = got_packfile_open_object(obj, id, repo);
377 		if (err)
378 			goto done;
379 		if (*obj == NULL)
380 			err = got_error(GOT_ERR_NO_OBJ);
381 	} else {
382 		err = read_object_header_privsep(obj, fd);
383 		if (err)
384 			goto done;
385 		memcpy((*obj)->id.sha1, id->sha1, SHA1_DIGEST_LENGTH);
386 	}
387 
388 	if (err == NULL) {
389 		(*obj)->refcnt++;
390 		err = got_repo_cache_object(repo, id, *obj);
391 	}
392 done:
393 	free(path);
394 	if (fd != -1)
395 		close(fd);
396 	return err;
397 
398 }
399 
400 const struct got_error *
401 got_object_open_by_id_str(struct got_object **obj, struct got_repository *repo,
402     const char *id_str)
403 {
404 	struct got_object_id id;
405 
406 	if (!got_parse_sha1_digest(id.sha1, id_str))
407 		return got_error(GOT_ERR_BAD_OBJ_ID_STR);
408 
409 	return got_object_open(obj, repo, &id);
410 }
411 
412 void
413 got_object_close(struct got_object *obj)
414 {
415 	if (obj->refcnt > 0) {
416 		obj->refcnt--;
417 		if (obj->refcnt > 0)
418 			return;
419 	}
420 
421 	if (obj->flags & GOT_OBJ_FLAG_DELTIFIED) {
422 		struct got_delta *delta;
423 		while (!SIMPLEQ_EMPTY(&obj->deltas.entries)) {
424 			delta = SIMPLEQ_FIRST(&obj->deltas.entries);
425 			SIMPLEQ_REMOVE_HEAD(&obj->deltas.entries, entry);
426 			got_delta_close(delta);
427 		}
428 	}
429 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
430 		free(obj->path_packfile);
431 	free(obj);
432 }
433 
434 struct got_commit_object *
435 got_object_commit_alloc_partial(void)
436 {
437 	struct got_commit_object *commit;
438 
439 	commit = calloc(1, sizeof(*commit));
440 	if (commit == NULL)
441 		return NULL;
442 	commit->tree_id = calloc(1, sizeof(*commit->tree_id));
443 	if (commit->tree_id == NULL) {
444 		free(commit);
445 		return NULL;
446 	}
447 
448 	SIMPLEQ_INIT(&commit->parent_ids);
449 
450 	return commit;
451 }
452 
453 const struct got_error *
454 got_object_open_as_commit(struct got_commit_object **commit,
455     struct got_repository *repo, struct got_object_id *id)
456 {
457 	const struct got_error *err;
458 	struct got_object *obj;
459 
460 	*commit = NULL;
461 
462 	err = got_object_open(&obj, repo, id);
463 	if (err)
464 		return err;
465 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_COMMIT) {
466 		err = got_error(GOT_ERR_OBJ_TYPE);
467 		goto done;
468 	}
469 
470 	err = got_object_commit_open(commit, repo, obj);
471 done:
472 	got_object_close(obj);
473 	return err;
474 }
475 
476 const struct got_error *
477 got_object_commit_add_parent(struct got_commit_object *commit,
478     const char *id_str)
479 {
480 	const struct got_error *err = NULL;
481 	struct got_object_qid *qid;
482 
483 	qid = calloc(1, sizeof(*qid));
484 	if (qid == NULL)
485 		return got_error_from_errno();
486 
487 	qid->id = calloc(1, sizeof(*qid->id));
488 	if (qid->id == NULL) {
489 		err = got_error_from_errno();
490 		free(qid);
491 		return err;
492 	}
493 
494 	if (!got_parse_sha1_digest(qid->id->sha1, id_str)) {
495 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
496 		free(qid->id);
497 		free(qid);
498 		return err;
499 	}
500 
501 	SIMPLEQ_INSERT_TAIL(&commit->parent_ids, qid, entry);
502 	commit->nparents++;
503 
504 	return NULL;
505 }
506 
507 static const struct got_error *
508 parse_gmtoff(time_t *gmtoff, const char *tzstr)
509 {
510 	int sign = 1;
511 	const char *p = tzstr;
512 	time_t h, m;
513 
514 	*gmtoff = 0;
515 
516 	if (*p == '-')
517 		sign = -1;
518 	else if (*p != '+')
519 		return got_error(GOT_ERR_BAD_OBJ_DATA);
520 	p++;
521 	if (!isdigit(*p) && !isdigit(*(p + 1)))
522 		return got_error(GOT_ERR_BAD_OBJ_DATA);
523 	h = (((*p - '0') * 10) + (*(p + 1) - '0'));
524 
525 	p += 2;
526 	if (!isdigit(*p) && !isdigit(*(p + 1)))
527 		return got_error(GOT_ERR_BAD_OBJ_DATA);
528 	m = ((*p - '0') * 10) + (*(p + 1) - '0');
529 
530 	*gmtoff = (h * 60 * 60 + m * 60) * sign;
531 	return NULL;
532 }
533 
534 static const struct got_error *
535 parse_commit_time(struct tm *tm, char *committer)
536 {
537 	const struct got_error *err = NULL;
538 	const char *errstr;
539 	char *space, *tzstr;
540 	time_t gmtoff;
541 	time_t time;
542 
543 	/* Parse and strip off trailing timezone indicator string. */
544 	space = strrchr(committer, ' ');
545 	if (space == NULL)
546 		return got_error(GOT_ERR_BAD_OBJ_DATA);
547 	tzstr = strdup(space + 1);
548 	if (tzstr == NULL)
549 		return got_error_from_errno();
550 	err = parse_gmtoff(&gmtoff, tzstr);
551 	free(tzstr);
552 	if (err)
553 		return err;
554 	*space = '\0';
555 
556 	/* Timestamp is separated from committer name + email by space. */
557 	space = strrchr(committer, ' ');
558 	if (space == NULL)
559 		return got_error(GOT_ERR_BAD_OBJ_DATA);
560 
561 	/* Timestamp parsed here is expressed in comitter's local time. */
562 	time = strtonum(space + 1, 0, INT64_MAX, &errstr);
563 	if (errstr)
564 		return got_error(GOT_ERR_BAD_OBJ_DATA);
565 
566 	/* Express the time stamp in UTC. */
567 	memset(tm, 0, sizeof(*tm));
568 	time -= gmtoff;
569 	if (localtime_r(&time, tm) == NULL)
570 		return got_error_from_errno();
571 	tm->tm_gmtoff = gmtoff;
572 
573 	/* Strip off parsed time information, leaving just author and email. */
574 	*space = '\0';
575 
576 	return NULL;
577 }
578 
579 static const struct got_error *
580 parse_commit_object(struct got_commit_object **commit, char *buf, size_t len)
581 {
582 	const struct got_error *err = NULL;
583 	char *s = buf;
584 	size_t tlen;
585 	ssize_t remain = (ssize_t)len;
586  
587 	*commit = got_object_commit_alloc_partial();
588 	if (*commit == NULL)
589 		return got_error_from_errno();
590 
591 	tlen = strlen(GOT_COMMIT_TAG_TREE);
592 	if (strncmp(s, GOT_COMMIT_TAG_TREE, tlen) == 0) {
593 		remain -= tlen;
594 		if (remain < SHA1_DIGEST_STRING_LENGTH) {
595 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
596 			goto done;
597 		}
598 		s += tlen;
599 		if (!got_parse_sha1_digest((*commit)->tree_id->sha1, s)) {
600 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
601 			goto done;
602 		}
603 		remain -= SHA1_DIGEST_STRING_LENGTH;
604 		s += SHA1_DIGEST_STRING_LENGTH;
605 	} else {
606 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
607 		goto done;
608 	}
609 
610 	tlen = strlen(GOT_COMMIT_TAG_PARENT);
611 	while (strncmp(s, GOT_COMMIT_TAG_PARENT, tlen) == 0) {
612 		remain -= tlen;
613 		if (remain < SHA1_DIGEST_STRING_LENGTH) {
614 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
615 			goto done;
616 		}
617 		s += tlen;
618 		err = got_object_commit_add_parent(*commit, s);
619 		if (err)
620 			goto done;
621 
622 		remain -= SHA1_DIGEST_STRING_LENGTH;
623 		s += SHA1_DIGEST_STRING_LENGTH;
624 	}
625 
626 	tlen = strlen(GOT_COMMIT_TAG_AUTHOR);
627 	if (strncmp(s, GOT_COMMIT_TAG_AUTHOR, tlen) == 0) {
628 		char *p;
629 		size_t slen;
630 
631 		remain -= tlen;
632 		if (remain <= 0) {
633 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
634 			goto done;
635 		}
636 		s += tlen;
637 		p = strchr(s, '\n');
638 		if (p == NULL) {
639 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
640 			goto done;
641 		}
642 		*p = '\0';
643 		slen = strlen(s);
644 		err = parse_commit_time(&(*commit)->tm_author, s);
645 		if (err)
646 			goto done;
647 		(*commit)->author = strdup(s);
648 		if ((*commit)->author == NULL) {
649 			err = got_error_from_errno();
650 			goto done;
651 		}
652 		s += slen + 1;
653 		remain -= slen + 1;
654 	}
655 
656 	tlen = strlen(GOT_COMMIT_TAG_COMMITTER);
657 	if (strncmp(s, GOT_COMMIT_TAG_COMMITTER, tlen) == 0) {
658 		char *p;
659 		size_t slen;
660 
661 		remain -= tlen;
662 		if (remain <= 0) {
663 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
664 			goto done;
665 		}
666 		s += tlen;
667 		p = strchr(s, '\n');
668 		if (p == NULL) {
669 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
670 			goto done;
671 		}
672 		*p = '\0';
673 		slen = strlen(s);
674 		err = parse_commit_time(&(*commit)->tm_committer, s);
675 		if (err)
676 			goto done;
677 		(*commit)->committer = strdup(s);
678 		if ((*commit)->committer == NULL) {
679 			err = got_error_from_errno();
680 			goto done;
681 		}
682 		s += slen + 1;
683 		remain -= slen + 1;
684 	}
685 
686 	(*commit)->logmsg = strndup(s, remain);
687 	if ((*commit)->logmsg == NULL) {
688 		err = got_error_from_errno();
689 		goto done;
690 	}
691 done:
692 	if (err) {
693 		got_object_commit_close(*commit);
694 		*commit = NULL;
695 	}
696 	return err;
697 }
698 
699 static void
700 tree_entry_close(struct got_tree_entry *te)
701 {
702 	free(te->id);
703 	free(te->name);
704 	free(te);
705 }
706 
707 struct got_tree_entry *
708 got_alloc_tree_entry_partial(void)
709 {
710 	struct got_tree_entry *te;
711 
712 	te = calloc(1, sizeof(*te));
713 	if (te == NULL)
714 		return NULL;
715 
716 	te->id = calloc(1, sizeof(*te->id));
717 	if (te->id == NULL) {
718 		free(te);
719 		te = NULL;
720 	}
721 	return te;
722 }
723 
724 static const struct got_error *
725 parse_tree_entry(struct got_tree_entry **te, size_t *elen, char *buf,
726     size_t maxlen)
727 {
728 	char *p = buf, *space;
729 	const struct got_error *err = NULL;
730 
731 	*te = got_alloc_tree_entry_partial();
732 	if (*te == NULL)
733 		return got_error_from_errno();
734 
735 	*elen = strlen(buf) + 1;
736 	if (*elen > maxlen) {
737 		free(*te);
738 		*te = NULL;
739 		return got_error(GOT_ERR_BAD_OBJ_DATA);
740 	}
741 
742 	space = strchr(buf, ' ');
743 	if (space == NULL) {
744 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
745 		free(*te);
746 		*te = NULL;
747 		return err;
748 	}
749 	while (*p != ' ') {
750 		if (*p < '0' && *p > '7') {
751 			err = got_error(GOT_ERR_BAD_OBJ_DATA);
752 			goto done;
753 		}
754 		(*te)->mode <<= 3;
755 		(*te)->mode |= *p - '0';
756 		p++;
757 	}
758 
759 	(*te)->name = strdup(space + 1);
760 	if (*elen > maxlen || maxlen - *elen < SHA1_DIGEST_LENGTH) {
761 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
762 		goto done;
763 	}
764 	buf += strlen(buf) + 1;
765 	memcpy((*te)->id->sha1, buf, SHA1_DIGEST_LENGTH);
766 	*elen += SHA1_DIGEST_LENGTH;
767 done:
768 	if (err) {
769 		tree_entry_close(*te);
770 		*te = NULL;
771 	}
772 	return err;
773 }
774 
775 static const struct got_error *
776 parse_tree_object(struct got_tree_object **tree, uint8_t *buf, size_t len)
777 {
778 	const struct got_error *err;
779 	size_t remain = len;
780 
781 	*tree = calloc(1, sizeof(**tree));
782 	if (*tree == NULL)
783 		return got_error_from_errno();
784 
785 	SIMPLEQ_INIT(&(*tree)->entries.head);
786 
787 	while (remain > 0) {
788 		struct got_tree_entry *te;
789 		size_t elen;
790 
791 		err = parse_tree_entry(&te, &elen, buf, remain);
792 		if (err)
793 			return err;
794 		(*tree)->entries.nentries++;
795 		SIMPLEQ_INSERT_TAIL(&(*tree)->entries.head, te, entry);
796 		buf += elen;
797 		remain -= elen;
798 	}
799 
800 	if (remain != 0) {
801 		got_object_tree_close(*tree);
802 		return got_error(GOT_ERR_BAD_OBJ_DATA);
803 	}
804 
805 	return NULL;
806 }
807 
808 static const struct got_error *
809 read_to_mem(uint8_t **outbuf, size_t *outlen, FILE *f)
810 {
811 	const struct got_error *err = NULL;
812 	static const size_t blocksize = 512;
813 	size_t n, total, remain;
814 	uint8_t *buf;
815 
816 	*outbuf = NULL;
817 	*outlen = 0;
818 
819 	buf = calloc(1, blocksize);
820 	if (buf == NULL)
821 		return got_error_from_errno();
822 
823 	remain = blocksize;
824 	total = 0;
825 	while (1) {
826 		if (remain == 0) {
827 			uint8_t *newbuf;
828 			newbuf = reallocarray(buf, 1, total + blocksize);
829 			if (newbuf == NULL) {
830 				err = got_error_from_errno();
831 				goto done;
832 			}
833 			buf = newbuf;
834 			remain += blocksize;
835 		}
836 		n = fread(buf + total, 1, remain, f);
837 		if (n == 0) {
838 			if (ferror(f)) {
839 				err = got_ferror(f, GOT_ERR_IO);
840 				goto done;
841 			}
842 			break; /* EOF */
843 		}
844 		remain -= n;
845 		total += n;
846 	};
847 
848 done:
849 	if (err == NULL) {
850 		*outbuf = buf;
851 		*outlen = total;
852 	} else
853 		free(buf);
854 	return err;
855 }
856 
857 static const struct got_error *
858 read_commit_object(struct got_commit_object **commit, struct got_object *obj,
859     FILE *f)
860 {
861 	const struct got_error *err = NULL;
862 	size_t len;
863 	uint8_t *p;
864 
865 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
866 		err = read_to_mem(&p, &len, f);
867 	else
868 		err = got_inflate_to_mem(&p, &len, f);
869 	if (err)
870 		return err;
871 
872 	if (len < obj->hdrlen + obj->size) {
873 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
874 		goto done;
875 	}
876 
877 	/* Skip object header. */
878 	len -= obj->hdrlen;
879 	err = parse_commit_object(commit, p + obj->hdrlen, len);
880 	free(p);
881 done:
882 	return err;
883 }
884 
885 static void
886 read_commit_object_privsep_child(struct got_object *obj, int obj_fd,
887     int imsg_fds[2])
888 {
889 	const struct got_error *err = NULL;
890 	struct got_commit_object *commit = NULL;
891 	struct imsgbuf ibuf;
892 	FILE *f = NULL;
893 	int status = 0;
894 
895 	setproctitle("read commit object");
896 	close(imsg_fds[0]);
897 	imsg_init(&ibuf, imsg_fds[1]);
898 
899 	/* revoke access to most system calls */
900 	if (pledge("stdio", NULL) == -1) {
901 		err = got_error_from_errno();
902 		goto done;
903 	}
904 
905 	f = fdopen(obj_fd, "rb");
906 	if (f == NULL) {
907 		err = got_error_from_errno();
908 		close(obj_fd);
909 		goto done;
910 	}
911 
912 	err = read_commit_object(&commit, obj, f);
913 	if (err)
914 		goto done;
915 
916 	err = got_privsep_send_commit(&ibuf, commit);
917 done:
918 	if (commit)
919 		got_object_commit_close(commit);
920 	if (err) {
921 		got_privsep_send_error(&ibuf, err);
922 		status = 1;
923 	}
924 	if (f)
925 		fclose(f);
926 	imsg_clear(&ibuf);
927 	close(imsg_fds[1]);
928 	_exit(status);
929 }
930 
931 static const struct got_error *
932 read_commit_object_privsep(struct got_commit_object **commit,
933     struct got_repository *repo, struct got_object *obj, int fd)
934 {
935 	const struct got_error *err = NULL, *err_child = NULL;
936 	struct imsgbuf parent_ibuf;
937 	int imsg_fds[2];
938 	pid_t pid;
939 
940 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
941 		return got_error_from_errno();
942 
943 	pid = fork();
944 	if (pid == -1)
945 		return got_error_from_errno();
946 	else if (pid == 0) {
947 		read_commit_object_privsep_child(obj, fd, imsg_fds);
948 		/* not reached */
949 	}
950 
951 	close(imsg_fds[1]);
952 	imsg_init(&parent_ibuf, imsg_fds[0]);
953 	err = got_privsep_recv_commit(commit, &parent_ibuf);
954 	imsg_clear(&parent_ibuf);
955 	err_child = wait_for_child(pid);
956 	close(imsg_fds[0]);
957 	return err ? err : err_child;
958 }
959 
960 const struct got_error *
961 got_object_commit_open(struct got_commit_object **commit,
962     struct got_repository *repo, struct got_object *obj)
963 {
964 	const struct got_error *err = NULL;
965 
966 	*commit = got_repo_get_cached_commit(repo, &obj->id);
967 	if (*commit != NULL) {
968 		(*commit)->refcnt++;
969 		return NULL;
970 	}
971 
972 	if (obj->type != GOT_OBJ_TYPE_COMMIT)
973 		return got_error(GOT_ERR_OBJ_TYPE);
974 
975 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
976 		uint8_t *buf;
977 		size_t len;
978 		err = got_packfile_extract_object_to_mem(&buf, &len, obj, repo);
979 		if (err)
980 			return err;
981 		obj->size = len;
982 		err = parse_commit_object(commit, buf, len);
983 		free(buf);
984 	} else {
985 		int fd;
986 		err = open_loose_object(&fd, obj, repo);
987 		if (err)
988 			return err;
989 		err = read_commit_object_privsep(commit, repo, obj, fd);
990 		close(fd);
991 	}
992 
993 	if (err == NULL) {
994 		(*commit)->refcnt++;
995 		err = got_repo_cache_commit(repo, &obj->id, *commit);
996 	}
997 
998 	return err;
999 }
1000 
1001 void
1002 got_object_commit_close(struct got_commit_object *commit)
1003 {
1004 	struct got_object_qid *qid;
1005 
1006 	if (commit->refcnt > 0) {
1007 		commit->refcnt--;
1008 		if (commit->refcnt > 0)
1009 			return;
1010 	}
1011 
1012 	while (!SIMPLEQ_EMPTY(&commit->parent_ids)) {
1013 		qid = SIMPLEQ_FIRST(&commit->parent_ids);
1014 		SIMPLEQ_REMOVE_HEAD(&commit->parent_ids, entry);
1015 		free(qid->id);
1016 		free(qid);
1017 	}
1018 
1019 	free(commit->tree_id);
1020 	free(commit->author);
1021 	free(commit->committer);
1022 	free(commit->logmsg);
1023 	free(commit);
1024 }
1025 
1026 static const struct got_error *
1027 read_tree_object(struct got_tree_object **tree, struct got_object *obj, FILE *f)
1028 {
1029 	const struct got_error *err = NULL;
1030 	size_t len;
1031 	uint8_t *p;
1032 
1033 	if (obj->flags & GOT_OBJ_FLAG_PACKED)
1034 		err = read_to_mem(&p, &len, f);
1035 	else
1036 		err = got_inflate_to_mem(&p, &len, f);
1037 	if (err)
1038 		return err;
1039 
1040 	if (len < obj->hdrlen + obj->size) {
1041 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
1042 		goto done;
1043 	}
1044 
1045 	/* Skip object header. */
1046 	len -= obj->hdrlen;
1047 	err = parse_tree_object(tree, p + obj->hdrlen, len);
1048 	free(p);
1049 done:
1050 	return err;
1051 }
1052 
1053 static void
1054 read_tree_object_privsep_child(struct got_object *obj, int obj_fd,
1055     int imsg_fds[2])
1056 {
1057 	const struct got_error *err = NULL;
1058 	struct got_tree_object *tree = NULL;
1059 	struct imsgbuf ibuf;
1060 	FILE *f = NULL;
1061 	int status = 0;
1062 
1063 	setproctitle("read tree object");
1064 	close(imsg_fds[0]);
1065 	imsg_init(&ibuf, imsg_fds[1]);
1066 
1067 	/* revoke access to most system calls */
1068 	if (pledge("stdio", NULL) == -1) {
1069 		err = got_error_from_errno();
1070 		goto done;
1071 	}
1072 
1073 	f = fdopen(obj_fd, "rb");
1074 	if (f == NULL) {
1075 		err = got_error_from_errno();
1076 		close(obj_fd);
1077 		goto done;
1078 	}
1079 
1080 	err = read_tree_object(&tree, obj, f);
1081 	if (err)
1082 		goto done;
1083 
1084 	err = got_privsep_send_tree(&ibuf, tree);
1085 done:
1086 	if (tree)
1087 		got_object_tree_close(tree);
1088 	if (err) {
1089 		got_privsep_send_error(&ibuf, err);
1090 		status = 1;
1091 	}
1092 	if (f)
1093 		fclose(f);
1094 	imsg_clear(&ibuf);
1095 	close(imsg_fds[1]);
1096 	_exit(status);
1097 }
1098 
1099 static const struct got_error *
1100 read_tree_object_privsep(struct got_tree_object **tree, struct got_object *obj,
1101     int fd)
1102 {
1103 	const struct got_error *err = NULL, *err_child = NULL;
1104 	struct imsgbuf parent_ibuf;
1105 	int imsg_fds[2];
1106 	pid_t pid;
1107 
1108 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
1109 		return got_error_from_errno();
1110 
1111 	pid = fork();
1112 	if (pid == -1)
1113 		return got_error_from_errno();
1114 	else if (pid == 0) {
1115 		read_tree_object_privsep_child(obj, fd, imsg_fds);
1116 		/* not reached */
1117 	}
1118 
1119 	close(imsg_fds[1]);
1120 	imsg_init(&parent_ibuf, imsg_fds[0]);
1121 	err = got_privsep_recv_tree(tree, &parent_ibuf);
1122 	imsg_clear(&parent_ibuf);
1123 	err_child = wait_for_child(pid);
1124 	close(imsg_fds[0]);
1125 	return err ? err : err_child;
1126 }
1127 
1128 const struct got_error *
1129 got_object_tree_open(struct got_tree_object **tree,
1130     struct got_repository *repo, struct got_object *obj)
1131 {
1132 	const struct got_error *err = NULL;
1133 
1134 	*tree = got_repo_get_cached_tree(repo, &obj->id);
1135 	if (*tree != NULL) {
1136 		(*tree)->refcnt++;
1137 		return NULL;
1138 	}
1139 
1140 	if (obj->type != GOT_OBJ_TYPE_TREE)
1141 		return got_error(GOT_ERR_OBJ_TYPE);
1142 
1143 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
1144 		uint8_t *buf;
1145 		size_t len;
1146 		err = got_packfile_extract_object_to_mem(&buf, &len, obj, repo);
1147 		if (err)
1148 			return err;
1149 		obj->size = len;
1150 		err = parse_tree_object(tree, buf, len);
1151 		free(buf);
1152 	} else {
1153 		int fd;
1154 		err = open_loose_object(&fd, obj, repo);
1155 		if (err)
1156 			return err;
1157 		err = read_tree_object_privsep(tree, obj, fd);
1158 		close(fd);
1159 	}
1160 
1161 	if (err == NULL) {
1162 		(*tree)->refcnt++;
1163 		err = got_repo_cache_tree(repo, &obj->id, *tree);
1164 	}
1165 
1166 	return err;
1167 }
1168 
1169 const struct got_error *
1170 got_object_open_as_tree(struct got_tree_object **tree,
1171     struct got_repository *repo, struct got_object_id *id)
1172 {
1173 	const struct got_error *err;
1174 	struct got_object *obj;
1175 
1176 	*tree = NULL;
1177 
1178 	err = got_object_open(&obj, repo, id);
1179 	if (err)
1180 		return err;
1181 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_TREE) {
1182 		err = got_error(GOT_ERR_OBJ_TYPE);
1183 		goto done;
1184 	}
1185 
1186 	err = got_object_tree_open(tree, repo, obj);
1187 done:
1188 	got_object_close(obj);
1189 	return err;
1190 }
1191 
1192 void
1193 got_object_tree_close(struct got_tree_object *tree)
1194 {
1195 	struct got_tree_entry *te;
1196 
1197 	if (tree->refcnt > 0) {
1198 		tree->refcnt--;
1199 		if (tree->refcnt > 0)
1200 			return;
1201 	}
1202 
1203 	while (!SIMPLEQ_EMPTY(&tree->entries.head)) {
1204 		te = SIMPLEQ_FIRST(&tree->entries.head);
1205 		SIMPLEQ_REMOVE_HEAD(&tree->entries.head, entry);
1206 		tree_entry_close(te);
1207 	}
1208 
1209 	free(tree);
1210 }
1211 
1212 const struct got_tree_entries *
1213 got_object_tree_get_entries(struct got_tree_object *tree)
1214 {
1215 	return &tree->entries;
1216 }
1217 
1218 static const struct got_error *
1219 read_blob_object_privsep_child(int outfd, int infd, int imsg_fds[2])
1220 {
1221 	const struct got_error *err = NULL;
1222 	struct imsgbuf ibuf;
1223 	int status = 0;
1224 	size_t size;
1225 	FILE *infile = NULL;
1226 
1227 	setproctitle("read blob object");
1228 	close(imsg_fds[0]);
1229 	imsg_init(&ibuf, imsg_fds[1]);
1230 
1231 	/* revoke access to most system calls */
1232 	if (pledge("stdio", NULL) == -1) {
1233 		err = got_error_from_errno();
1234 		goto done;
1235 	}
1236 
1237 	infile = fdopen(infd, "rb");
1238 	if (infile == NULL) {
1239 		err = got_error_from_errno();
1240 		close(infd);
1241 		goto done;
1242 	}
1243 	err = got_inflate_to_fd(&size, infile, outfd);
1244 	fclose(infile);
1245 	if (err)
1246 		goto done;
1247 
1248 	err = got_privsep_send_blob(&ibuf, size);
1249 done:
1250 	if (err) {
1251 		got_privsep_send_error(&ibuf, err);
1252 		status = 1;
1253 	}
1254 	close(outfd);
1255 	imsg_clear(&ibuf);
1256 	close(imsg_fds[1]);
1257 	_exit(status);
1258 }
1259 
1260 static const struct got_error *
1261 read_blob_object_privsep(size_t *size, int outfd, int infd)
1262 {
1263 	struct imsgbuf parent_ibuf;
1264 	int imsg_fds[2];
1265 	const struct got_error *err = NULL, *err_child = NULL;
1266 	pid_t pid;
1267 
1268 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1)
1269 		return got_error_from_errno();
1270 
1271 	pid = fork();
1272 	if (pid == -1)
1273 		return got_error_from_errno();
1274 	else if (pid == 0) {
1275 		read_blob_object_privsep_child(outfd, infd, imsg_fds);
1276 		/* not reached */
1277 	}
1278 
1279 	close(imsg_fds[1]);
1280 	imsg_init(&parent_ibuf, imsg_fds[0]);
1281 	err = got_privsep_recv_blob(size, &parent_ibuf);
1282 	imsg_clear(&parent_ibuf);
1283 	err_child = wait_for_child(pid);
1284 	close(imsg_fds[0]);
1285 	if (lseek(outfd, SEEK_SET, 0) == -1)
1286 		err = got_error_from_errno();
1287 	return err ? err : err_child;
1288 }
1289 
1290 const struct got_error *
1291 got_object_blob_open(struct got_blob_object **blob,
1292     struct got_repository *repo, struct got_object *obj, size_t blocksize)
1293 {
1294 	const struct got_error *err = NULL;
1295 
1296 	if (obj->type != GOT_OBJ_TYPE_BLOB)
1297 		return got_error(GOT_ERR_OBJ_TYPE);
1298 
1299 	if (blocksize < obj->hdrlen)
1300 		return got_error(GOT_ERR_NO_SPACE);
1301 
1302 	*blob = calloc(1, sizeof(**blob));
1303 	if (*blob == NULL)
1304 		return got_error_from_errno();
1305 
1306 	(*blob)->read_buf = calloc(1, blocksize);
1307 	if ((*blob)->read_buf == NULL) {
1308 		err = got_error_from_errno();
1309 		goto done;
1310 	}
1311 	if (obj->flags & GOT_OBJ_FLAG_PACKED) {
1312 		err = got_packfile_extract_object(&((*blob)->f), obj, repo);
1313 		if (err)
1314 			goto done;
1315 	} else {
1316 		int infd, outfd;
1317 		size_t size;
1318 		struct stat sb;
1319 
1320 		err = open_loose_object(&infd, obj, repo);
1321 		if (err)
1322 			goto done;
1323 
1324 
1325 		outfd = got_opentempfd();
1326 		if (outfd == -1) {
1327 			err = got_error_from_errno();
1328 			close(infd);
1329 			goto done;
1330 		}
1331 
1332 		err = read_blob_object_privsep(&size, outfd, infd);
1333 		close(infd);
1334 		if (err)
1335 			goto done;
1336 
1337 		if (size != obj->hdrlen + obj->size) {
1338 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1339 			close(outfd);
1340 			goto done;
1341 		}
1342 
1343 		if (fstat(outfd, &sb) == -1) {
1344 			err = got_error_from_errno();
1345 			close(outfd);
1346 			goto done;
1347 		}
1348 
1349 		if (sb.st_size != size) {
1350 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1351 			close(outfd);
1352 			goto done;
1353 		}
1354 
1355 		(*blob)->f = fdopen(outfd, "rb");
1356 		if ((*blob)->f == NULL) {
1357 			err = got_error_from_errno();
1358 			close(outfd);
1359 			goto done;
1360 		}
1361 	}
1362 
1363 	(*blob)->hdrlen = obj->hdrlen;
1364 	(*blob)->blocksize = blocksize;
1365 	memcpy(&(*blob)->id.sha1, obj->id.sha1, SHA1_DIGEST_LENGTH);
1366 
1367 done:
1368 	if (err && *blob) {
1369 		if ((*blob)->f)
1370 			fclose((*blob)->f);
1371 		free((*blob)->read_buf);
1372 		free(*blob);
1373 		*blob = NULL;
1374 	}
1375 	return err;
1376 }
1377 
1378 const struct got_error *
1379 got_object_open_as_blob(struct got_blob_object **blob,
1380     struct got_repository *repo, struct got_object_id *id,
1381     size_t blocksize)
1382 {
1383 	const struct got_error *err;
1384 	struct got_object *obj;
1385 
1386 	*blob = NULL;
1387 
1388 	err = got_object_open(&obj, repo, id);
1389 	if (err)
1390 		return err;
1391 	if (got_object_get_type(obj) != GOT_OBJ_TYPE_BLOB) {
1392 		err = got_error(GOT_ERR_OBJ_TYPE);
1393 		goto done;
1394 	}
1395 
1396 	err = got_object_blob_open(blob, repo, obj, blocksize);
1397 done:
1398 	got_object_close(obj);
1399 	return err;
1400 }
1401 
1402 void
1403 got_object_blob_close(struct got_blob_object *blob)
1404 {
1405 	free(blob->read_buf);
1406 	fclose(blob->f);
1407 	free(blob);
1408 }
1409 
1410 char *
1411 got_object_blob_id_str(struct got_blob_object *blob, char *buf, size_t size)
1412 {
1413 	return got_sha1_digest_to_str(blob->id.sha1, buf, size);
1414 }
1415 
1416 size_t
1417 got_object_blob_get_hdrlen(struct got_blob_object *blob)
1418 {
1419 	return blob->hdrlen;
1420 }
1421 
1422 const uint8_t *
1423 got_object_blob_get_read_buf(struct got_blob_object *blob)
1424 {
1425 	return blob->read_buf;
1426 }
1427 
1428 const struct got_error *
1429 got_object_blob_read_block(size_t *outlenp, struct got_blob_object *blob)
1430 {
1431 	size_t n;
1432 
1433 	n = fread(blob->read_buf, 1, blob->blocksize, blob->f);
1434 	if (n == 0 && ferror(blob->f))
1435 		return got_ferror(blob->f, GOT_ERR_IO);
1436 	*outlenp = n;
1437 	return NULL;
1438 }
1439 
1440 const struct got_error *
1441 got_object_blob_dump_to_file(size_t *total_len, size_t *nlines,
1442     FILE *outfile, struct got_blob_object *blob)
1443 {
1444 	const struct got_error *err = NULL;
1445 	size_t len, hdrlen;
1446 	const uint8_t *buf;
1447 	int i;
1448 
1449 	if (total_len)
1450 		*total_len = 0;
1451 	if (nlines)
1452 		*nlines = 0;
1453 
1454 	hdrlen = got_object_blob_get_hdrlen(blob);
1455 	do {
1456 		err = got_object_blob_read_block(&len, blob);
1457 		if (err)
1458 			return err;
1459 		if (len == 0)
1460 			break;
1461 		if (total_len)
1462 			*total_len += len;
1463 		buf = got_object_blob_get_read_buf(blob);
1464 		if (nlines) {
1465 			for (i = 0; i < len; i++) {
1466 				if (buf[i] == '\n')
1467 					(*nlines)++;
1468 			}
1469 		}
1470 		/* Skip blob object header first time around. */
1471 		fwrite(buf + hdrlen, len - hdrlen, 1, outfile);
1472 		hdrlen = 0;
1473 	} while (len != 0);
1474 
1475 	fflush(outfile);
1476 	rewind(outfile);
1477 
1478 	return NULL;
1479 }
1480 
1481 static struct got_tree_entry *
1482 find_entry_by_name(struct got_tree_object *tree, const char *name)
1483 {
1484 	struct got_tree_entry *te;
1485 
1486 	SIMPLEQ_FOREACH(te, &tree->entries.head, entry) {
1487 		if (strcmp(te->name, name) == 0)
1488 			return te;
1489 	}
1490 	return NULL;
1491 }
1492 
1493 const struct got_error *
1494 got_object_open_by_path(struct got_object **obj, struct got_repository *repo,
1495     struct got_object_id *commit_id, const char *path)
1496 {
1497 	const struct got_error *err = NULL;
1498 	struct got_commit_object *commit = NULL;
1499 	struct got_tree_object *tree = NULL;
1500 	struct got_tree_entry *te = NULL;
1501 	char *seg, *s, *s0 = NULL;
1502 	size_t len = strlen(path);
1503 
1504 	*obj = NULL;
1505 
1506 	/* We are expecting an absolute in-repository path. */
1507 	if (path[0] != '/')
1508 		return got_error(GOT_ERR_NOT_ABSPATH);
1509 
1510 	err = got_object_open_as_commit(&commit, repo, commit_id);
1511 	if (err)
1512 		goto done;
1513 
1514 	/* Handle opening of root of commit's tree. */
1515 	if (path[1] == '\0') {
1516 		err = got_object_open(obj, repo, commit->tree_id);
1517 		if (err)
1518 			goto done;
1519 		return NULL;
1520 	}
1521 
1522 	err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1523 	if (err)
1524 		goto done;
1525 
1526 	s0 = strdup(path);
1527 	if (s0 == NULL) {
1528 		err = got_error_from_errno();
1529 		goto done;
1530 	}
1531 	err = got_canonpath(path, s0, len + 1);
1532 	if (err)
1533 		goto done;
1534 
1535 	s = s0;
1536 	s++; /* skip leading '/' */
1537 	len--;
1538 	seg = s;
1539 	while (len > 0) {
1540 		struct got_tree_object *next_tree;
1541 
1542 		if (*s != '/') {
1543 			s++;
1544 			len--;
1545 			if (*s)
1546 				continue;
1547 		}
1548 
1549 		/* end of path segment */
1550 		*s = '\0';
1551 
1552 		te = find_entry_by_name(tree, seg);
1553 		if (te == NULL) {
1554 			err = got_error(GOT_ERR_NO_OBJ);
1555 			goto done;
1556 		}
1557 
1558 		if (len == 0)
1559 			break;
1560 
1561 		seg = s + 1;
1562 		s++;
1563 		len--;
1564 		if (*s) {
1565 			err = got_object_open_as_tree(&next_tree, repo,
1566 			    te->id);
1567 			te = NULL;
1568 			if (err)
1569 				goto done;
1570 			got_object_tree_close(tree);
1571 			tree = next_tree;
1572 		}
1573 	}
1574 
1575 	if (te) {
1576 		err = got_object_open(obj, repo, te->id);
1577 		if (err)
1578 			goto done;
1579 	} else
1580 		err = got_error(GOT_ERR_NO_OBJ);
1581 done:
1582 	free(s0);
1583 	if (commit)
1584 		got_object_commit_close(commit);
1585 	if (tree)
1586 		got_object_tree_close(tree);
1587 	return err;
1588 }