1 /*
2  * Copyright (c) 2022 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/queue.h>
18 #include <sys/tree.h>
19 #include <sys/stat.h>
20 
21 #include <errno.h>
22 #include <limits.h>
23 #include <sha1.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <unistd.h>
28 
29 #include "got_error.h"
30 #include "got_object.h"
31 #include "got_repository.h"
32 #include "got_path.h"
33 
34 #include "got_lib_delta.h"
35 #include "got_lib_object.h"
36 #include "got_lib_object_cache.h"
37 #include "got_lib_object_parse.h"
38 #include "got_lib_pack.h"
39 #include "got_lib_repository.h"
40 
41 const struct got_error *
42 got_object_open_packed(struct got_object **obj, struct got_object_id *id,
43     struct got_repository *repo)
44 {
45 	const struct got_error *err = NULL;
46 	struct got_pack *pack = NULL;
47 	struct got_packidx *packidx = NULL;
48 	int idx;
49 	char *path_packfile;
50 
51 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
52 	if (err)
53 		return err;
54 
55 	err = got_packidx_get_packfile_path(&path_packfile,
56 	    packidx->path_packidx);
57 	if (err)
58 		return err;
59 
60 	pack = got_repo_get_cached_pack(repo, path_packfile);
61 	if (pack == NULL) {
62 		err = got_repo_cache_pack(&pack, repo, path_packfile, packidx);
63 		if (err)
64 			goto done;
65 	}
66 
67 	err = got_packfile_open_object(obj, pack, packidx, idx, id);
68 	if (err)
69 		return err;
70 	(*obj)->refcnt++;
71 
72 	err = got_repo_cache_object(repo, id, *obj);
73 	if (err) {
74 		if (err->code == GOT_ERR_OBJ_EXISTS ||
75 		    err->code == GOT_ERR_OBJ_TOO_LARGE)
76 			err = NULL;
77 	}
78 done:
79 	free(path_packfile);
80 	return err;
81 }
82 
83 const struct got_error *
84 got_object_open_from_packfile(struct got_object **obj, struct got_object_id *id,
85     struct got_pack *pack, struct got_packidx *packidx, int obj_idx,
86     struct got_repository *repo)
87 {
88 	return got_error(GOT_ERR_NOT_IMPL);
89 }
90 
91 const struct got_error *
92 got_object_read_raw_delta(uint64_t *base_size, uint64_t *result_size,
93     off_t *delta_size, off_t *delta_compressed_size, off_t *delta_offset,
94     off_t *delta_out_offset, struct got_object_id **base_id, int delta_cache_fd,
95     struct got_packidx *packidx, int obj_idx, struct got_object_id *id,
96     struct got_repository *repo)
97 {
98 	return got_error(GOT_ERR_NOT_IMPL);
99 }
100 
101 const struct got_error *
102 got_object_open(struct got_object **obj, struct got_repository *repo,
103     struct got_object_id *id)
104 {
105 	const struct got_error *err = NULL;
106 	int fd;
107 
108 	*obj = got_repo_get_cached_object(repo, id);
109 	if (*obj != NULL) {
110 		(*obj)->refcnt++;
111 		return NULL;
112 	}
113 
114 	err = got_object_open_packed(obj, id, repo);
115 	if (err) {
116 		if (err->code != GOT_ERR_NO_OBJ)
117 			return err;
118 	} else
119 		return NULL;
120 
121 	err = got_object_open_loose_fd(&fd, id, repo);
122 	if (err) {
123 		if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
124 			err = got_error_no_obj(id);
125 		return err;
126 	}
127 
128 	err = got_object_read_header(obj, fd);
129 	if (err)
130 		goto done;
131 
132 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
133 	(*obj)->refcnt++;
134 
135 	err = got_repo_cache_object(repo, id, *obj);
136 	if (err) {
137 		if (err->code == GOT_ERR_OBJ_EXISTS ||
138 		    err->code == GOT_ERR_OBJ_TOO_LARGE)
139 			err = NULL;
140 	}
141 done:
142 	if (close(fd) == -1 && err == NULL)
143 		err = got_error_from_errno("close");
144 	return err;
145 }
146 
147 static const struct got_error *
148 wrap_fd(FILE **f, int wrapped_fd)
149 {
150 	const struct got_error *err = NULL;
151 	int fd;
152 
153 	if (ftruncate(wrapped_fd, 0L) == -1)
154 		return got_error_from_errno("ftruncate");
155 
156 	if (lseek(wrapped_fd, 0L, SEEK_SET) == -1)
157 		return got_error_from_errno("lseek");
158 
159 	fd = dup(wrapped_fd);
160 	if (fd == -1)
161 		return got_error_from_errno("dup");
162 
163 	*f = fdopen(fd, "w+");
164 	if (*f == NULL) {
165 		err = got_error_from_errno("fdopen");
166 		close(fd);
167 	}
168 	return err;
169 }
170 
171 static const struct got_error *
172 read_packed_object_raw(uint8_t **outbuf, off_t *size, size_t *hdrlen,
173     int outfd, struct got_pack *pack, struct got_packidx *packidx, int idx,
174     struct got_object_id *id)
175 {
176 	const struct got_error *err = NULL;
177 	uint64_t raw_size = 0;
178 	struct got_object *obj;
179 	FILE *outfile = NULL, *basefile = NULL, *accumfile = NULL;
180 
181 	*outbuf = NULL;
182 	*size = 0;
183 	*hdrlen = 0;
184 
185 	err = got_packfile_open_object(&obj, pack, packidx, idx, id);
186 	if (err)
187 		return err;
188 
189 	if (obj->flags & GOT_OBJ_FLAG_DELTIFIED) {
190 		err = got_pack_get_max_delta_object_size(&raw_size, obj, pack);
191 		if (err)
192 			goto done;
193 	} else
194 		raw_size = obj->size;
195 
196 	if (raw_size <= GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
197 		size_t len;
198 		err = got_packfile_extract_object_to_mem(outbuf, &len,
199 		    obj, pack);
200 		if (err)
201 			goto done;
202 		*size = (off_t)len;
203 	} else {
204 		/*
205 		 * XXX This uses 3 file extra descriptors for no good reason.
206 		 * We should have got_packfile_extract_object_to_fd().
207 		 */
208 		err = wrap_fd(&outfile, outfd);
209 		if (err)
210 			goto done;
211 		err = wrap_fd(&basefile, pack->basefd);
212 		if (err)
213 			goto done;
214 		err = wrap_fd(&accumfile, pack->accumfd);
215 		if (err)
216 			goto done;
217 		err = got_packfile_extract_object(pack, obj, outfile, basefile,
218 		    accumfile);
219 		if (err)
220 			goto done;
221 		*size = obj->size;
222 	}
223 
224 	*hdrlen = obj->hdrlen;
225 done:
226 	got_object_close(obj);
227 	if (outfile && fclose(outfile) == EOF && err == NULL)
228 		err = got_error_from_errno("fclose");
229 	if (basefile && fclose(basefile) == EOF && err == NULL)
230 		err = got_error_from_errno("fclose");
231 	if (accumfile && fclose(accumfile) == EOF && err == NULL)
232 		err = got_error_from_errno("fclose");
233 	return err;
234 
235 }
236 
237 static void
238 put_raw_object_tempfile(struct got_raw_object *obj)
239 {
240 	struct got_repository *repo = obj->close_arg;
241 
242 	if (obj->tempfile_idx != -1)
243 		got_repo_temp_fds_put(obj->tempfile_idx, repo);
244 }
245 
246 /* *outfd must be initialized to -1 by caller */
247 const struct got_error *
248 got_object_raw_open(struct got_raw_object **obj, int *outfd,
249     struct got_repository *repo, struct got_object_id *id)
250 {
251 	const struct got_error *err = NULL;
252 	struct got_packidx *packidx = NULL;
253 	int idx, tempfd, tempfile_idx;
254 	uint8_t *outbuf = NULL;
255 	off_t size = 0;
256 	size_t hdrlen = 0;
257 	char *path_packfile = NULL;
258 
259 	*obj = got_repo_get_cached_raw_object(repo, id);
260 	if (*obj != NULL) {
261 		(*obj)->refcnt++;
262 		return NULL;
263 	}
264 
265 	err = got_repo_temp_fds_get(&tempfd, &tempfile_idx, repo);
266 	if (err)
267 		return err;
268 
269 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
270 	if (err == NULL) {
271 		struct got_pack *pack = NULL;
272 
273 		err = got_packidx_get_packfile_path(&path_packfile,
274 		    packidx->path_packidx);
275 		if (err)
276 			goto done;
277 
278 		pack = got_repo_get_cached_pack(repo, path_packfile);
279 		if (pack == NULL) {
280 			err = got_repo_cache_pack(&pack, repo, path_packfile,
281 			    packidx);
282 			if (err)
283 				goto done;
284 		}
285 		err = read_packed_object_raw(&outbuf, &size, &hdrlen,
286 		    tempfd, pack, packidx, idx, id);
287 		if (err)
288 			goto done;
289 	} else if (err->code == GOT_ERR_NO_OBJ) {
290 		int fd;
291 
292 		err = got_object_open_loose_fd(&fd, id, repo);
293 		if (err)
294 			goto done;
295 		err = got_object_read_raw(&outbuf, &size, &hdrlen,
296 		    GOT_DELTA_RESULT_SIZE_CACHED_MAX, tempfd, id, fd);
297 		if (close(fd) == -1 && err == NULL)
298 			err = got_error_from_errno("close");
299 		if (err)
300 			goto done;
301 	}
302 
303 	if (outbuf == NULL) {
304 		if (*outfd != -1) {
305 			err = got_error_msg(GOT_ERR_NOT_IMPL, "bad outfd");
306 			goto done;
307 		}
308 
309 		/*
310 		 * Duplicate tempfile descriptor to allow use of
311 		 * fdopen(3) inside got_object_raw_alloc().
312 		 */
313 		*outfd = dup(tempfd);
314 		if (*outfd == -1) {
315 			err = got_error_from_errno("dup");
316 			goto done;
317 		}
318 	}
319 
320 	err = got_object_raw_alloc(obj, outbuf, outfd,
321 	    GOT_DELTA_RESULT_SIZE_CACHED_MAX, hdrlen, size);
322 	if (err)
323 		goto done;
324 
325 	err = got_repo_cache_raw_object(repo, id, *obj);
326 	if (err) {
327 		if (err->code == GOT_ERR_OBJ_EXISTS ||
328 		    err->code == GOT_ERR_OBJ_TOO_LARGE)
329 			err = NULL;
330 	}
331 done:
332 	free(path_packfile);
333 	if (err) {
334 		if (*obj) {
335 			got_object_raw_close(*obj);
336 			*obj = NULL;
337 		}
338 		free(outbuf);
339 		got_repo_temp_fds_put(tempfile_idx, repo);
340 		if (*outfd != -1) {
341 			close(*outfd);
342 			*outfd = -1;
343 		}
344 	} else {
345 		if (((*obj)->f == NULL && (*obj)->fd == -1)) {
346 			/* This raw object is not backed by a file. */
347 			got_repo_temp_fds_put(tempfile_idx, repo);
348 			if (*outfd != -1) {
349 				close(*outfd);
350 				*outfd = -1;
351 			}
352 		} else {
353 			(*obj)->tempfile_idx = tempfile_idx;
354 			(*obj)->close_cb = put_raw_object_tempfile;
355 			(*obj)->close_arg = repo;
356 		}
357 	}
358 	return err;
359 }
360 
361 static const struct got_error *
362 open_commit(struct got_commit_object **commit,
363     struct got_repository *repo, struct got_object_id *id, int check_cache)
364 {
365 	const struct got_error *err = NULL;
366 	struct got_packidx *packidx = NULL;
367 	int idx;
368 	char *path_packfile = NULL;
369 
370 	if (check_cache) {
371 		*commit = got_repo_get_cached_commit(repo, id);
372 		if (*commit != NULL) {
373 			(*commit)->refcnt++;
374 			return NULL;
375 		}
376 	} else
377 		*commit = NULL;
378 
379 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
380 	if (err == NULL) {
381 		struct got_pack *pack = NULL;
382 		struct got_object *obj;
383 		uint8_t *buf;
384 		size_t len;
385 
386 		err = got_packidx_get_packfile_path(&path_packfile,
387 		    packidx->path_packidx);
388 		if (err)
389 			return err;
390 
391 		pack = got_repo_get_cached_pack(repo, path_packfile);
392 		if (pack == NULL) {
393 			err = got_repo_cache_pack(&pack, repo, path_packfile,
394 			    packidx);
395 			if (err)
396 				goto done;
397 		}
398 		err = got_packfile_open_object(&obj, pack, packidx, idx, id);
399 		if (err)
400 			goto done;
401 		err = got_packfile_extract_object_to_mem(&buf, &len,
402 		    obj, pack);
403 		got_object_close(obj);
404 		if (err)
405 			goto done;
406 		err = got_object_parse_commit(commit, buf, len);
407 		free(buf);
408 	} else if (err->code == GOT_ERR_NO_OBJ) {
409 		int fd;
410 
411 		err = got_object_open_loose_fd(&fd, id, repo);
412 		if (err)
413 			return err;
414 		err = got_object_read_commit(commit, fd, id, 0);
415 		if (close(fd) == -1 && err == NULL)
416 			err = got_error_from_errno("close");
417 		if (err)
418 			return err;
419 	}
420 
421 	if (err == NULL) {
422 		(*commit)->refcnt++;
423 		err = got_repo_cache_commit(repo, id, *commit);
424 		if (err) {
425 			if (err->code == GOT_ERR_OBJ_EXISTS ||
426 			    err->code == GOT_ERR_OBJ_TOO_LARGE)
427 				err = NULL;
428 		}
429 	}
430 done:
431 	free(path_packfile);
432 	return err;
433 }
434 
435 const struct got_error *
436 got_object_open_as_commit(struct got_commit_object **commit,
437     struct got_repository *repo, struct got_object_id *id)
438 {
439 	*commit = got_repo_get_cached_commit(repo, id);
440 	if (*commit != NULL) {
441 		(*commit)->refcnt++;
442 		return NULL;
443 	}
444 
445 	return open_commit(commit, repo, id, 0);
446 }
447 
448 const struct got_error *
449 got_object_commit_open(struct got_commit_object **commit,
450     struct got_repository *repo, struct got_object *obj)
451 {
452 	return open_commit(commit, repo, got_object_get_id(obj), 1);
453 }
454 
455 static const struct got_error *
456 open_tree(struct got_tree_object **tree,
457     struct got_repository *repo, struct got_object_id *id, int check_cache)
458 {
459 	const struct got_error *err = NULL;
460 	struct got_packidx *packidx = NULL;
461 	int idx;
462 	char *path_packfile = NULL;
463 	struct got_parsed_tree_entry *entries = NULL;
464 	size_t nentries = 0, nentries_alloc = 0, i;
465 	uint8_t *buf = NULL;
466 
467 	if (check_cache) {
468 		*tree = got_repo_get_cached_tree(repo, id);
469 		if (*tree != NULL) {
470 			(*tree)->refcnt++;
471 			return NULL;
472 		}
473 	} else
474 		*tree = NULL;
475 
476 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
477 	if (err == NULL) {
478 		struct got_pack *pack = NULL;
479 		struct got_object *obj;
480 		size_t len;
481 
482 		err = got_packidx_get_packfile_path(&path_packfile,
483 		    packidx->path_packidx);
484 		if (err)
485 			return err;
486 
487 		pack = got_repo_get_cached_pack(repo, path_packfile);
488 		if (pack == NULL) {
489 			err = got_repo_cache_pack(&pack, repo, path_packfile,
490 			    packidx);
491 			if (err)
492 				goto done;
493 		}
494 		err = got_packfile_open_object(&obj, pack, packidx, idx, id);
495 		if (err)
496 			goto done;
497 		err = got_packfile_extract_object_to_mem(&buf, &len,
498 		    obj, pack);
499 		got_object_close(obj);
500 		if (err)
501 			goto done;
502 		err = got_object_parse_tree(&entries, &nentries,
503 		    &nentries_alloc, buf, len);
504 		if (err)
505 			goto done;
506 	} else if (err->code == GOT_ERR_NO_OBJ) {
507 		int fd;
508 
509 		err = got_object_open_loose_fd(&fd, id, repo);
510 		if (err)
511 			return err;
512 		err = got_object_read_tree(&entries, &nentries,
513 		    &nentries_alloc, &buf, fd, id);
514 		if (close(fd) == -1 && err == NULL)
515 			err = got_error_from_errno("close");
516 		if (err)
517 			goto done;
518 	} else
519 		goto done;
520 
521 	*tree = malloc(sizeof(**tree));
522 	if (*tree == NULL) {
523 		err = got_error_from_errno("malloc");
524 		goto done;
525 	}
526 	(*tree)->entries = calloc(nentries, sizeof(struct got_tree_entry));
527 	if ((*tree)->entries == NULL) {
528 		err = got_error_from_errno("malloc");
529 		goto done;
530 	}
531 	(*tree)->nentries = nentries;
532 	(*tree)->refcnt = 0;
533 
534 	for (i = 0; i < nentries; i++) {
535 		struct got_parsed_tree_entry *pe = &entries[i];
536 		struct got_tree_entry *te = &(*tree)->entries[i];
537 	
538 		if (strlcpy(te->name, pe->name,
539 		    sizeof(te->name)) >= sizeof(te->name)) {
540 			err = got_error(GOT_ERR_NO_SPACE);
541 			goto done;
542 		}
543 		memcpy(te->id.sha1, pe->id, SHA1_DIGEST_LENGTH);
544 		te->mode = pe->mode;
545 		te->idx = i;
546 	}
547 done:
548 	free(path_packfile);
549 	free(entries);
550 	free(buf);
551 	if (err == NULL) {
552 		(*tree)->refcnt++;
553 		err = got_repo_cache_tree(repo, id, *tree);
554 		if (err) {
555 			if (err->code == GOT_ERR_OBJ_EXISTS ||
556 			    err->code == GOT_ERR_OBJ_TOO_LARGE)
557 				err = NULL;
558 		}
559 	}
560 	if (err) {
561 		if (*tree)
562 			free((*tree)->entries);
563 		free(*tree);
564 		*tree = NULL;
565 	}
566 	return err;
567 }
568 
569 const struct got_error *
570 got_object_open_as_tree(struct got_tree_object **tree,
571     struct got_repository *repo, struct got_object_id *id)
572 {
573 	*tree = got_repo_get_cached_tree(repo, id);
574 	if (*tree != NULL) {
575 		(*tree)->refcnt++;
576 		return NULL;
577 	}
578 
579 	return open_tree(tree, repo, id, 0);
580 }
581 
582 const struct got_error *
583 got_object_tree_open(struct got_tree_object **tree,
584     struct got_repository *repo, struct got_object *obj)
585 {
586 	return open_tree(tree, repo, got_object_get_id(obj), 1);
587 }
588 
589 const struct got_error *
590 got_object_open_as_blob(struct got_blob_object **blob,
591     struct got_repository *repo, struct got_object_id *id, size_t blocksize,
592     int outfd)
593 {
594 	return got_error(GOT_ERR_NOT_IMPL);
595 }
596 
597 const struct got_error *
598 got_object_blob_open(struct got_blob_object **blob,
599     struct got_repository *repo, struct got_object *obj, size_t blocksize,
600     int outfd)
601 {
602 	return got_error(GOT_ERR_NOT_IMPL);
603 }
604 
605 static const struct got_error *
606 open_tag(struct got_tag_object **tag, struct got_repository *repo,
607     struct got_object_id *id, int check_cache)
608 {
609 	const struct got_error *err = NULL;
610 	struct got_packidx *packidx = NULL;
611 	int idx;
612 	char *path_packfile = NULL;
613 	struct got_object *obj = NULL;
614 	int obj_type = GOT_OBJ_TYPE_ANY;
615 
616 	if (check_cache) {
617 		*tag = got_repo_get_cached_tag(repo, id);
618 		if (*tag != NULL) {
619 			(*tag)->refcnt++;
620 			return NULL;
621 		}
622 	} else
623 		*tag = NULL;
624 
625 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
626 	if (err == NULL) {
627 		struct got_pack *pack = NULL;
628 		uint8_t *buf = NULL;
629 		size_t len;
630 
631 		err = got_packidx_get_packfile_path(&path_packfile,
632 		    packidx->path_packidx);
633 		if (err)
634 			return err;
635 
636 		pack = got_repo_get_cached_pack(repo, path_packfile);
637 		if (pack == NULL) {
638 			err = got_repo_cache_pack(&pack, repo, path_packfile,
639 			    packidx);
640 			if (err)
641 				goto done;
642 		}
643 
644 		/* Beware of "lightweight" tags: Check object type first. */
645 		err = got_packfile_open_object(&obj, pack, packidx, idx, id);
646 		if (err)
647 			goto done;
648 		obj_type = obj->type;
649 		if (obj_type != GOT_OBJ_TYPE_TAG) {
650 			err = got_error(GOT_ERR_OBJ_TYPE);
651 			got_object_close(obj);
652 			goto done;
653 		}
654 		err = got_packfile_extract_object_to_mem(&buf, &len,
655 		    obj, pack);
656 		got_object_close(obj);
657 		if (err)
658 			goto done;
659 		err = got_object_parse_tag(tag, buf, len);
660 		free(buf);
661 	} else if (err->code == GOT_ERR_NO_OBJ) {
662 		int fd;
663 
664 		err = got_object_open_loose_fd(&fd, id, repo);
665 		if (err)
666 			return err;
667 		err = got_object_read_header(&obj, fd);
668 		if (close(fd) == -1 && err == NULL)
669 			err = got_error_from_errno("close");
670 		if (err)
671 			return err;
672 		obj_type = obj->type;
673 		got_object_close(obj);
674 		if (obj_type != GOT_OBJ_TYPE_TAG)
675 			return got_error(GOT_ERR_OBJ_TYPE);
676 
677 		err = got_object_open_loose_fd(&fd, id, repo);
678 		if (err)
679 			return err;
680 		err = got_object_read_tag(tag, fd, id, 0);
681 		if (close(fd) == -1 && err == NULL)
682 			err = got_error_from_errno("close");
683 		if (err)
684 			return err;
685 	}
686 
687 	if (err == NULL) {
688 		(*tag)->refcnt++;
689 		err = got_repo_cache_tag(repo, id, *tag);
690 		if (err) {
691 			if (err->code == GOT_ERR_OBJ_EXISTS ||
692 			    err->code == GOT_ERR_OBJ_TOO_LARGE)
693 				err = NULL;
694 		}
695 	}
696 done:
697 	free(path_packfile);
698 	return err;
699 }
700 
701 const struct got_error *
702 got_object_open_as_tag(struct got_tag_object **tag,
703     struct got_repository *repo, struct got_object_id *id)
704 {
705 	*tag = got_repo_get_cached_tag(repo, id);
706 	if (*tag != NULL) {
707 		(*tag)->refcnt++;
708 		return NULL;
709 	}
710 
711 	return open_tag(tag, repo, id, 0);
712 }
713 
714 const struct got_error *
715 got_object_tag_open(struct got_tag_object **tag,
716     struct got_repository *repo, struct got_object *obj)
717 {
718 	return open_tag(tag, repo, got_object_get_id(obj), 1);
719 }