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Date:: Tue Feb 28 18:00:30 2023 UTC
Message:: add got_repo_get_object_format() and use it to avoid hardcoding the digest type in a few places. ok stsp@
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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/types.h>
18 #include <sys/queue.h>
19 #include <sys/stat.h>
20 
21 #include <errno.h>
22 #include <dirent.h>
23 #include <limits.h>
24 #include <sha1.h>
25 #include <sha2.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30 #include <util.h>
31 #include <zlib.h>
32 #include <time.h>
33 #include <libgen.h>
34 
35 #include "got_error.h"
36 #include "got_object.h"
37 #include "got_repository.h"
38 #include "got_reference.h"
39 #include "got_opentemp.h"
40 #include "got_path.h"
41 
42 #include "got_lib_hash.h"
43 #include "got_lib_delta.h"
44 #include "got_lib_inflate.h"
45 #include "got_lib_object.h"
46 #include "got_lib_object_idset.h"
47 #include "got_lib_lockfile.h"
48 
49 #ifndef nitems
50 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
51 #endif
52 
53 #define GOT_REF_HEADS	"heads"
54 #define GOT_REF_TAGS	"tags"
55 #define GOT_REF_REMOTES	"remotes"
56 
57 /*
58  * We do not resolve tags yet, and don't yet care about sorting refs either,
59  * so packed-refs files we write contain a minimal header which disables all
60  * packed-refs "traits" supported by Git.
61  */
62 #define GOT_PACKED_REFS_HEADER	"# pack-refs with:"
63 
64 /* A symbolic reference. */
65 struct got_symref {
66 	char *name;
67 	char *ref;
68 };
69 
70 #define GOT_REF_RECURSE_MAX	20
71 
72 /* A non-symbolic reference (there is no better designation). */
73 struct got_ref {
74 	char *name;
75 	struct got_object_id id;
76 };
77 
78 /* A reference which points to an arbitrary object. */
79 struct got_reference {
80 	unsigned int flags;
81 #define GOT_REF_IS_SYMBOLIC	0x01
82 #define GOT_REF_IS_PACKED	0x02
83 
84 	union {
85 		struct got_ref ref;
86 		struct got_symref symref;
87 	} ref;
88 
89 	struct got_lockfile *lf;
90 	time_t mtime;
91 
92 	/* Cached timestamp for got_ref_cmp_by_commit_timestamp_descending() */
93 	time_t committer_time;
94 };
95 
96 static const struct got_error *
97 alloc_ref(struct got_reference **ref, const char *name,
98     struct got_object_id *id, int flags, time_t mtime)
99 {
100 	const struct got_error *err = NULL;
101 
102 	*ref = calloc(1, sizeof(**ref));
103 	if (*ref == NULL)
104 		return got_error_from_errno("calloc");
105 
106 	memcpy(&(*ref)->ref.ref.id, id, sizeof((*ref)->ref.ref.id));
107 	(*ref)->flags = flags;
108 	(*ref)->ref.ref.name = strdup(name);
109 	(*ref)->mtime = mtime;
110 	if ((*ref)->ref.ref.name == NULL) {
111 		err = got_error_from_errno("strdup");
112 		got_ref_close(*ref);
113 		*ref = NULL;
114 	}
115 	return err;
116 }
117 
118 static const struct got_error *
119 alloc_symref(struct got_reference **ref, const char *name,
120     const char *target_ref, int flags)
121 {
122 	const struct got_error *err = NULL;
123 
124 	*ref = calloc(1, sizeof(**ref));
125 	if (*ref == NULL)
126 		return got_error_from_errno("calloc");
127 
128 	(*ref)->flags = GOT_REF_IS_SYMBOLIC | flags;
129 	(*ref)->ref.symref.name = strdup(name);
130 	if ((*ref)->ref.symref.name == NULL) {
131 		err = got_error_from_errno("strdup");
132 		got_ref_close(*ref);
133 		*ref = NULL;
134 		return err;
135 	}
136 	(*ref)->ref.symref.ref = strdup(target_ref);
137 	if ((*ref)->ref.symref.ref == NULL) {
138 		err = got_error_from_errno("strdup");
139 		got_ref_close(*ref);
140 		*ref = NULL;
141 	}
142 	return err;
143 }
144 
145 static const struct got_error *
146 parse_symref(struct got_reference **ref, const char *name, const char *line)
147 {
148 	if (line[0] == '\0')
149 		return got_error(GOT_ERR_BAD_REF_DATA);
150 
151 	return alloc_symref(ref, name, line, 0);
152 }
153 
154 static const struct got_error *
155 parse_ref_line(struct got_reference **ref, const char *name, const char *line,
156     time_t mtime, enum got_hash_algorithm algo)
157 {
158 	struct got_object_id id;
159 
160 	if (strncmp(line, "ref: ", 5) == 0) {
161 		line += 5;
162 		return parse_symref(ref, name, line);
163 	}
164 
165 	if (!got_parse_object_id(&id, line, algo))
166 		return got_error(GOT_ERR_BAD_REF_DATA);
167 
168 	return alloc_ref(ref, name, &id, 0, mtime);
169 }
170 
171 static const struct got_error *
172 parse_ref_file(struct got_reference **ref, const char *name,
173     const char *absname, const char *abspath, int lock,
174     enum got_hash_algorithm algo)
175 {
176 	const struct got_error *err = NULL;
177 	FILE *f;
178 	char *line = NULL;
179 	size_t linesize = 0;
180 	ssize_t linelen;
181 	struct got_lockfile *lf = NULL;
182 	struct stat sb;
183 
184 	if (lock) {
185 		err = got_lockfile_lock(&lf, abspath, -1);
186 		if (err) {
187 			if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
188 				err = got_error_not_ref(name);
189 			return err;
190 		}
191 	}
192 
193 	f = fopen(abspath, "rbe");
194 	if (f == NULL) {
195 		if (errno != ENOTDIR && errno != ENOENT)
196 			err = got_error_from_errno2("fopen", abspath);
197 		else
198 			err = got_error_not_ref(name);
199 		if (lock)
200 			got_lockfile_unlock(lf, -1);
201 		return err;
202 	}
203 	if (fstat(fileno(f), &sb) == -1) {
204 		err = got_error_from_errno2("fstat", abspath);
205 		goto done;
206 	}
207 
208 	linelen = getline(&line, &linesize, f);
209 	if (linelen == -1) {
210 		if (feof(f))
211 			err = NULL; /* ignore empty files (could be locks) */
212 		else {
213 			if (errno == EISDIR)
214 				err = got_error(GOT_ERR_NOT_REF);
215 			else if (ferror(f))
216 				err = got_ferror(f, GOT_ERR_IO);
217 			else
218 				err = got_error_from_errno2("getline", abspath);
219 		}
220 		if (lock)
221 			got_lockfile_unlock(lf, -1);
222 		goto done;
223 	}
224 	while (linelen > 0 && line[linelen - 1] == '\n') {
225 		line[linelen - 1] = '\0';
226 		linelen--;
227 	}
228 
229 	err = parse_ref_line(ref, absname, line, sb.st_mtime, algo);
230 	if (lock) {
231 		if (err)
232 			got_lockfile_unlock(lf, -1);
233 		else {
234 			if (*ref)
235 				(*ref)->lf = lf;
236 			else
237 				got_lockfile_unlock(lf, -1);
238 		}
239 	}
240 done:
241 	free(line);
242 	if (fclose(f) == EOF && err == NULL) {
243 		err = got_error_from_errno("fclose");
244 		if (*ref) {
245 			if (lock)
246 				got_ref_unlock(*ref);
247 			got_ref_close(*ref);
248 			*ref = NULL;
249 		}
250 	}
251 	return err;
252 }
253 
254 static int
255 is_well_known_ref(const char *refname)
256 {
257 	return (strcmp(refname, GOT_REF_HEAD) == 0 ||
258 	    strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
259 	    strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
260 	    strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
261 }
262 
263 static char *
264 get_refs_dir_path(struct got_repository *repo, const char *refname)
265 {
266 	if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
267 		return strdup(got_repo_get_path_git_dir(repo));
268 
269 	return got_repo_get_path_refs(repo);
270 }
271 
272 const struct got_error *
273 got_ref_alloc(struct got_reference **ref, const char *name,
274     struct got_object_id *id)
275 {
276 	if (!got_ref_name_is_valid(name))
277 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
278 
279 	return alloc_ref(ref, name, id, 0, 0);
280 }
281 
282 const struct got_error *
283 got_ref_alloc_symref(struct got_reference **ref, const char *name,
284 	struct got_reference *target_ref)
285 {
286 	if (!got_ref_name_is_valid(name))
287 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
288 
289 	return alloc_symref(ref, name, got_ref_get_name(target_ref), 0);
290 }
291 
292 static const struct got_error *
293 parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
294     const char *line, time_t mtime, enum got_hash_algorithm algo)
295 {
296 	struct got_object_id id;
297 	const char *name;
298 
299 	*ref = NULL;
300 
301 	if (line[0] == '#' || line[0] == '^')
302 		return NULL;
303 
304 	if (!got_parse_object_id(&id, line, algo))
305 		return got_error(GOT_ERR_BAD_REF_DATA);
306 
307 	if (abs_refname) {
308 		if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
309 			return NULL;
310 		name = abs_refname;
311 	} else
312 		name = line + SHA1_DIGEST_STRING_LENGTH;
313 
314 	return alloc_ref(ref, name, &id, GOT_REF_IS_PACKED, mtime);
315 }
316 
317 static const struct got_error *
318 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
319     int nsubdirs, const char *refname, time_t mtime,
320     enum got_hash_algorithm algo)
321 {
322 	const struct got_error *err = NULL;
323 	char *abs_refname;
324 	char *line = NULL;
325 	size_t linesize = 0;
326 	ssize_t linelen;
327 	int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
328 
329 	*ref = NULL;
330 
331 	if (ref_is_absolute)
332 		abs_refname = (char *)refname;
333 	do {
334 		linelen = getline(&line, &linesize, f);
335 		if (linelen == -1) {
336 			if (feof(f))
337 				break;
338 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
339 			break;
340 		}
341 		if (linelen > 0 && line[linelen - 1] == '\n')
342 			line[linelen - 1] = '\0';
343 		for (i = 0; i < nsubdirs; i++) {
344 			if (!ref_is_absolute &&
345 			    asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
346 			    refname) == -1)
347 				return got_error_from_errno("asprintf");
348 			err = parse_packed_ref_line(ref, abs_refname, line,
349 			    mtime, algo);
350 			if (!ref_is_absolute)
351 				free(abs_refname);
352 			if (err || *ref != NULL)
353 				break;
354 		}
355 		if (err)
356 			break;
357 	} while (*ref == NULL);
358 	free(line);
359 
360 	return err;
361 }
362 
363 static const struct got_error *
364 open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
365     const char *name, int lock, enum got_hash_algorithm algo)
366 {
367 	const struct got_error *err = NULL;
368 	char *path = NULL;
369 	char *absname = NULL;
370 	int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
371 	int ref_is_well_known = (subdir[0] == '\0' && is_well_known_ref(name));
372 
373 	*ref = NULL;
374 
375 	if (!got_ref_name_is_valid(name))
376 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
377 
378 	if (ref_is_absolute || ref_is_well_known) {
379 		if (asprintf(&path, "%s/%s", path_refs, name) == -1)
380 			return got_error_from_errno("asprintf");
381 		absname = (char *)name;
382 	} else {
383 		if (asprintf(&path, "%s/%s%s%s", path_refs, subdir,
384 		    subdir[0] ? "/" : "", name) == -1)
385 			return got_error_from_errno("asprintf");
386 
387 		if (asprintf(&absname, "refs/%s%s%s",
388 		    subdir, subdir[0] ? "/" : "", name) == -1) {
389 			err = got_error_from_errno("asprintf");
390 			goto done;
391 		}
392 	}
393 
394 	err = parse_ref_file(ref, name, absname, path, lock, algo);
395 done:
396 	if (!ref_is_absolute && !ref_is_well_known)
397 		free(absname);
398 	free(path);
399 	return err;
400 }
401 
402 const struct got_error *
403 got_ref_open(struct got_reference **ref, struct got_repository *repo,
404     const char *refname, int lock)
405 {
406 	const struct got_error *err = NULL;
407 	char *packed_refs_path = NULL, *path_refs = NULL;
408 	const char *subdirs[] = {
409 	    GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
410 	};
411 	size_t i;
412 	int well_known = is_well_known_ref(refname);
413 	struct got_lockfile *lf = NULL;
414 
415 	*ref = NULL;
416 
417 	path_refs = get_refs_dir_path(repo, refname);
418 	if (path_refs == NULL) {
419 		err = got_error_from_errno2("get_refs_dir_path", refname);
420 		goto done;
421 	}
422 
423 	if (well_known) {
424 		err = open_ref(ref, path_refs, "", refname, lock,
425 		    got_repo_get_object_format(repo));
426 	} else {
427 		FILE *f;
428 
429 		/* Search on-disk refs before packed refs! */
430 		for (i = 0; i < nitems(subdirs); i++) {
431 			err = open_ref(ref, path_refs, subdirs[i], refname,
432 			    lock, got_repo_get_object_format(repo));
433 			if ((err && err->code != GOT_ERR_NOT_REF) || *ref)
434 				goto done;
435 		}
436 
437 		packed_refs_path = got_repo_get_path_packed_refs(repo);
438 		if (packed_refs_path == NULL) {
439 			err = got_error_from_errno(
440 			    "got_repo_get_path_packed_refs");
441 			goto done;
442 		}
443 
444 		if (lock) {
445 			err = got_lockfile_lock(&lf, packed_refs_path, -1);
446 			if (err)
447 				goto done;
448 		}
449 		f = fopen(packed_refs_path, "rbe");
450 		if (f != NULL) {
451 			struct stat sb;
452 			if (fstat(fileno(f), &sb) == -1) {
453 				err = got_error_from_errno2("fstat",
454 				    packed_refs_path);
455 				goto done;
456 			}
457 			err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
458 			    refname, sb.st_mtime,
459 			    got_repo_get_object_format(repo));
460 			if (!err) {
461 				if (fclose(f) == EOF) {
462 					err = got_error_from_errno("fclose");
463 					got_ref_close(*ref);
464 					*ref = NULL;
465 				} else if (*ref)
466 					(*ref)->lf = lf;
467 			}
468 		}
469 	}
470 done:
471 	if (!err && *ref == NULL)
472 		err = got_error_not_ref(refname);
473 	if (err && lf)
474 		got_lockfile_unlock(lf, -1);
475 	free(packed_refs_path);
476 	free(path_refs);
477 	return err;
478 }
479 
480 void
481 got_ref_close(struct got_reference *ref)
482 {
483 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
484 		free(ref->ref.symref.name);
485 		free(ref->ref.symref.ref);
486 	} else
487 		free(ref->ref.ref.name);
488 	free(ref);
489 }
490 
491 struct got_reference *
492 got_ref_dup(struct got_reference *ref)
493 {
494 	struct got_reference *ret;
495 
496 	ret = calloc(1, sizeof(*ret));
497 	if (ret == NULL)
498 		return NULL;
499 
500 	ret->flags = ref->flags;
501 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
502 		ret->ref.symref.name = strdup(ref->ref.symref.name);
503 		if (ret->ref.symref.name == NULL) {
504 			free(ret);
505 			return NULL;
506 		}
507 		ret->ref.symref.ref = strdup(ref->ref.symref.ref);
508 		if (ret->ref.symref.ref == NULL) {
509 			free(ret->ref.symref.name);
510 			free(ret);
511 			return NULL;
512 		}
513 	} else {
514 		ret->ref.ref.name = strdup(ref->ref.ref.name);
515 		if (ret->ref.ref.name == NULL) {
516 			free(ret);
517 			return NULL;
518 		}
519 		memcpy(&ret->ref.ref.id, &ref->ref.ref.id,
520 		    sizeof(ret->ref.ref.id));
521 	}
522 
523 	return ret;
524 }
525 
526 const struct got_error *
527 got_reflist_entry_dup(struct got_reflist_entry **newp,
528     struct got_reflist_entry *re)
529 {
530 	const struct got_error *err = NULL;
531 	struct got_reflist_entry *new;
532 
533 	*newp = NULL;
534 
535 	new = malloc(sizeof(*new));
536 	if (new == NULL)
537 		return got_error_from_errno("malloc");
538 
539 	new->ref = got_ref_dup(re->ref);
540 	if (new->ref == NULL) {
541 		err = got_error_from_errno("got_ref_dup");
542 		free(new);
543 		return err;
544 	}
545 
546 	*newp = new;
547 	return NULL;
548 }
549 
550 const struct got_error *
551 got_ref_resolve_symbolic(struct got_reference **resolved,
552     struct got_repository *repo, struct got_reference *ref)
553 {
554 	struct got_reference *nextref;
555 	const struct got_error *err;
556 
557 	err = got_ref_open(&nextref, repo, ref->ref.symref.ref, 0);
558 	if (err)
559 		return err;
560 
561 	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
562 		err = got_ref_resolve_symbolic(resolved, repo, nextref);
563 	else
564 		*resolved = got_ref_dup(nextref);
565 
566 	got_ref_close(nextref);
567 	return err;
568 }
569 
570 static const struct got_error *
571 ref_resolve(struct got_object_id **id, struct got_repository *repo,
572     struct got_reference *ref, int recursion)
573 {
574 	const struct got_error *err;
575 
576 	if (recursion <= 0)
577 		return got_error_msg(GOT_ERR_RECURSION,
578 		    "reference recursion limit reached");
579 
580 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
581 		struct got_reference *resolved = NULL;
582 		err = got_ref_resolve_symbolic(&resolved, repo, ref);
583 		if (err == NULL)
584 			err = ref_resolve(id, repo, resolved, --recursion);
585 		if (resolved)
586 			got_ref_close(resolved);
587 		return err;
588 	}
589 
590 	*id = calloc(1, sizeof(**id));
591 	if (*id == NULL)
592 		return got_error_from_errno("calloc");
593 	memcpy(*id, &ref->ref.ref.id, sizeof(**id));
594 	return NULL;
595 }
596 
597 const struct got_error *
598 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
599     struct got_reference *ref)
600 {
601 	return ref_resolve(id, repo, ref, GOT_REF_RECURSE_MAX);
602 }
603 
604 char *
605 got_ref_to_str(struct got_reference *ref)
606 {
607 	char *str;
608 
609 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
610 		return strdup(ref->ref.symref.ref);
611 
612 	if (got_object_id_str(&str, &ref->ref.ref.id) != NULL)
613 		return NULL;
614 
615 	return str;
616 }
617 
618 const char *
619 got_ref_get_name(struct got_reference *ref)
620 {
621 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
622 		return ref->ref.symref.name;
623 
624 	return ref->ref.ref.name;
625 }
626 
627 const char *
628 got_ref_get_symref_target(struct got_reference *ref)
629 {
630 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
631 		return ref->ref.symref.ref;
632 
633 	return NULL;
634 }
635 
636 time_t
637 got_ref_get_mtime(struct got_reference *ref)
638 {
639 	return ref->mtime;
640 }
641 
642 const struct got_error *
643 got_ref_cmp_by_name(void *arg, int *cmp, struct got_reference *re1,
644     struct got_reference* re2)
645 {
646 	const char *name1 = got_ref_get_name(re1);
647 	const char *name2 = got_ref_get_name(re2);
648 
649 	*cmp = got_path_cmp(name1, name2, strlen(name1), strlen(name2));
650 	return NULL;
651 }
652 
653 const struct got_error *
654 got_ref_cmp_tags(void *arg, int *cmp, struct got_reference *ref1,
655     struct got_reference *ref2)
656 {
657 	const struct got_error *err = NULL;
658 	struct got_repository *repo = arg;
659 	struct got_object_id *id1, *id2 = NULL;
660 	struct got_tag_object *tag1 = NULL, *tag2 = NULL;
661 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
662 	time_t time1, time2;
663 
664 	*cmp = 0;
665 
666 	err = got_ref_resolve(&id1, repo, ref1);
667 	if (err)
668 		return err;
669 	err = got_object_open_as_tag(&tag1, repo, id1);
670 	if (err) {
671 		if (err->code != GOT_ERR_OBJ_TYPE)
672 			goto done;
673 		/* "lightweight" tag */
674 		err = got_object_open_as_commit(&commit1, repo, id1);
675 		if (err)
676 			goto done;
677 		time1 = got_object_commit_get_committer_time(commit1);
678 	} else
679 		time1 = got_object_tag_get_tagger_time(tag1);
680 
681 	err = got_ref_resolve(&id2, repo, ref2);
682 	if (err)
683 		goto done;
684 	err = got_object_open_as_tag(&tag2, repo, id2);
685 	if (err) {
686 		if (err->code != GOT_ERR_OBJ_TYPE)
687 			goto done;
688 		/* "lightweight" tag */
689 		err = got_object_open_as_commit(&commit2, repo, id2);
690 		if (err)
691 			goto done;
692 		time2 = got_object_commit_get_committer_time(commit2);
693 	} else
694 		time2 = got_object_tag_get_tagger_time(tag2);
695 
696 	/* Put latest tags first. */
697 	if (time1 < time2)
698 		*cmp = 1;
699 	else if (time1 > time2)
700 		*cmp = -1;
701 	else
702 		err = got_ref_cmp_by_name(NULL, cmp, ref2, ref1);
703 done:
704 	free(id1);
705 	free(id2);
706 	if (tag1)
707 		got_object_tag_close(tag1);
708 	if (tag2)
709 		got_object_tag_close(tag2);
710 	if (commit1)
711 		got_object_commit_close(commit1);
712 	if (commit2)
713 		got_object_commit_close(commit2);
714 	return err;
715 }
716 
717 static const struct got_error *
718 get_committer_time(struct got_reference *ref, struct got_repository *repo)
719 {
720 	const struct got_error *err = NULL;
721 	int obj_type;
722 	struct got_commit_object *commit = NULL;
723 	struct got_tag_object *tag = NULL;
724 	struct got_object_id *id = NULL;
725 
726 	err = got_ref_resolve(&id, repo, ref);
727 	if (err)
728 		return err;
729 
730 	err = got_object_get_type(&obj_type, repo, id);
731 	if (err)
732 		goto done;
733 
734 	switch (obj_type) {
735 	case GOT_OBJ_TYPE_COMMIT:
736 		err = got_object_open_as_commit(&commit, repo, id);
737 		if (err)
738 			goto done;
739 		ref->committer_time =
740 		    got_object_commit_get_committer_time(commit);
741 		break;
742 	case GOT_OBJ_TYPE_TAG:
743 		err = got_object_open_as_tag(&tag, repo, id);
744 		if (err)
745 			goto done;
746 		ref->committer_time = got_object_tag_get_tagger_time(tag);
747 		break;
748 	default:
749 		/* best effort for other object types */
750 		ref->committer_time = got_ref_get_mtime(ref);
751 		break;
752 	}
753 done:
754 	free(id);
755 	if (commit)
756 		got_object_commit_close(commit);
757 	if (tag)
758 		got_object_tag_close(tag);
759 	return err;
760 }
761 
762 const struct got_error *
763 got_ref_cmp_by_commit_timestamp_descending(void *arg, int *cmp,
764     struct got_reference *ref1, struct got_reference *ref2)
765 {
766 	const struct got_error *err = NULL;
767 	struct got_repository *repo = arg;
768 
769 	*cmp = 0;
770 
771 	if (ref1->committer_time == 0) {
772 		err = get_committer_time(ref1, repo);
773 		if (err)
774 			return err;
775 	}
776 	if (ref2->committer_time == 0) {
777 		err = get_committer_time(ref2, repo);
778 		if (err)
779 			return err;
780 	}
781 
782 	if (ref1->committer_time < ref2->committer_time)
783 		*cmp = 1;
784 	else if (ref2->committer_time < ref1->committer_time)
785 		*cmp = -1;
786 	else
787 		return got_ref_cmp_by_name(arg, cmp, ref1, ref2);
788 
789 	return err;
790 }
791 
792 const struct got_error *
793 got_reflist_insert(struct got_reflist_entry **newp,
794     struct got_reflist_head *refs, struct got_reference *ref,
795     got_ref_cmp_cb cmp_cb, void *cmp_arg)
796 {
797 	const struct got_error *err;
798 	struct got_reflist_entry *new, *re;
799 	int cmp;
800 
801 	*newp = NULL;
802 
803 	if (cmp_cb != got_ref_cmp_by_name && (ref->flags & GOT_REF_IS_PACKED)) {
804 		/*
805 		 * If we are not sorting elements by name then we must still
806 		 * detect collisions between a packed ref and an on-disk ref
807 		 * using the same name. On-disk refs take precedence and are
808 		 * already present on the list before packed refs get added.
809 		 */
810 		TAILQ_FOREACH(re, refs, entry) {
811 			err = got_ref_cmp_by_name(NULL, &cmp, re->ref, ref);
812 			if (err)
813 				return err;
814 			if (cmp == 0)
815 				return NULL;
816 		}
817 	}
818 
819 	new = malloc(sizeof(*new));
820 	if (new == NULL)
821 		return got_error_from_errno("malloc");
822 	new->ref = ref;
823 	*newp = new;
824 
825 	/*
826 	 * We must de-duplicate entries on insert because packed-refs may
827 	 * contain redundant entries. On-disk refs take precedence.
828 	 * This code assumes that on-disk revs are read before packed-refs.
829 	 * We're iterating the list anyway, so insert elements sorted by name.
830 	 *
831 	 * Many callers will provide paths in a somewhat sorted order.
832 	 * Iterating backwards from the tail of the list should be more
833 	 * efficient than traversing through the entire list each time
834 	 * an element is inserted.
835 	 */
836 	re = TAILQ_LAST(refs, got_reflist_head);
837 	while (re) {
838 		err = (*cmp_cb)(cmp_arg, &cmp, re->ref, new->ref);
839 		if (err)
840 			return err;
841 		if (cmp == 0) {
842 			/* duplicate */
843 			free(new);
844 			*newp = NULL;
845 			return NULL;
846 		} else if (cmp < 0) {
847 			TAILQ_INSERT_AFTER(refs, re, new, entry);
848 			return NULL;
849 		}
850 		re = TAILQ_PREV(re, got_reflist_head, entry);
851 	}
852 
853 	TAILQ_INSERT_HEAD(refs, new, entry);
854 	return NULL;
855 }
856 
857 const struct got_error *
858 got_reflist_sort(struct got_reflist_head *refs,
859     got_ref_cmp_cb cmp_cb, void *cmp_arg)
860 {
861 	const struct got_error *err = NULL;
862 	struct got_reflist_entry *re, *tmp, *new;
863 	struct got_reflist_head sorted;
864 
865 	TAILQ_INIT(&sorted);
866 
867 	TAILQ_FOREACH_SAFE(re, refs, entry, tmp) {
868 		struct got_reference *ref = re->ref;
869 		TAILQ_REMOVE(refs, re, entry);
870 		free(re);
871 		err = got_reflist_insert(&new, &sorted, ref, cmp_cb, cmp_arg);
872 		if (err || new == NULL /* duplicate */)
873 			got_ref_close(ref);
874 		if (err)
875 			return err;
876 	}
877 
878 	TAILQ_CONCAT(refs, &sorted, entry);
879 	return NULL;
880 }
881 
882 static const struct got_error *
883 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
884     const char *subdir, struct got_repository *repo,
885     got_ref_cmp_cb cmp_cb, void *cmp_arg)
886 {
887 	const struct got_error *err = NULL;
888 	DIR *d = NULL;
889 	char *path_subdir;
890 
891 	while (subdir[0] == '/')
892 		subdir++;
893 
894 	if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
895 		return got_error_from_errno("asprintf");
896 
897 	d = opendir(path_subdir);
898 	if (d == NULL)
899 		goto done;
900 
901 	for (;;) {
902 		struct dirent *dent;
903 		struct got_reference *ref;
904 		char *child;
905 		int type;
906 
907 		dent = readdir(d);
908 		if (dent == NULL)
909 			break;
910 
911 		if (strcmp(dent->d_name, ".") == 0 ||
912 		    strcmp(dent->d_name, "..") == 0)
913 			continue;
914 
915 		err = got_path_dirent_type(&type, path_subdir, dent);
916 		if (err)
917 			break;
918 
919 		switch (type) {
920 		case DT_REG:
921 			err = open_ref(&ref, path_refs, subdir, dent->d_name,
922 			    0, got_repo_get_object_format(repo));
923 			if (err)
924 				goto done;
925 			if (ref) {
926 				struct got_reflist_entry *new;
927 				err = got_reflist_insert(&new, refs, ref,
928 				    cmp_cb, cmp_arg);
929 				if (err || new == NULL /* duplicate */)
930 					got_ref_close(ref);
931 				if (err)
932 					goto done;
933 			}
934 			break;
935 		case DT_DIR:
936 			if (asprintf(&child, "%s%s%s", subdir,
937 			    subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
938 				err = got_error_from_errno("asprintf");
939 				break;
940 			}
941 			err = gather_on_disk_refs(refs, path_refs, child, repo,
942 			    cmp_cb, cmp_arg);
943 			free(child);
944 			break;
945 		default:
946 			break;
947 		}
948 	}
949 done:
950 	if (d)
951 		closedir(d);
952 	free(path_subdir);
953 	return err;
954 }
955 
956 const struct got_error *
957 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo,
958     const char *ref_namespace, got_ref_cmp_cb cmp_cb, void *cmp_arg)
959 {
960 	const struct got_error *err;
961 	char *packed_refs_path = NULL, *path_refs = NULL;
962 	char *abs_namespace = NULL, *buf = NULL;
963 	const char *ondisk_ref_namespace = NULL;
964 	char *line = NULL;
965 	FILE *f = NULL;
966 	struct got_reference *ref;
967 	struct got_reflist_entry *new;
968 
969 	if (ref_namespace == NULL || ref_namespace[0] == '\0') {
970 		path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
971 		if (path_refs == NULL) {
972 			err = got_error_from_errno("get_refs_dir_path");
973 			goto done;
974 		}
975 		err = open_ref(&ref, path_refs, "", GOT_REF_HEAD, 0,
976 		    got_repo_get_object_format(repo));
977 		if (err)
978 			goto done;
979 		err = got_reflist_insert(&new, refs, ref, cmp_cb, cmp_arg);
980 		if (err || new == NULL /* duplicate */)
981 			got_ref_close(ref);
982 		if (err && err->code != GOT_ERR_NOT_REF)
983 			goto done;
984 	} else {
985 		/* Try listing a single reference. */
986 		const char *refname = ref_namespace;
987 		path_refs = get_refs_dir_path(repo, refname);
988 		if (path_refs == NULL) {
989 			err = got_error_from_errno("get_refs_dir_path");
990 			goto done;
991 		}
992 		err = open_ref(&ref, path_refs, "", refname, 0,
993 		    got_repo_get_object_format(repo));
994 		if (err) {
995 			if (err->code != GOT_ERR_NOT_REF)
996 				goto done;
997 			/* Try to look up references in a given namespace. */
998 		} else {
999 			err = got_reflist_insert(&new, refs, ref,
1000 			    cmp_cb, cmp_arg);
1001 			if (err || new == NULL /* duplicate */)
1002 				got_ref_close(ref);
1003 			return err;
1004 		}
1005 	}
1006 
1007 	if (ref_namespace) {
1008 		size_t len;
1009 		/* Canonicalize the path to eliminate double-slashes if any. */
1010 		if (asprintf(&abs_namespace, "/%s", ref_namespace) == -1) {
1011 			err = got_error_from_errno("asprintf");
1012 			goto done;
1013 		}
1014 		len = strlen(abs_namespace) + 1;
1015 		buf = malloc(len);
1016 		if (buf == NULL) {
1017 			err = got_error_from_errno("malloc");
1018 			goto done;
1019 		}
1020 		err = got_canonpath(abs_namespace, buf, len);
1021 		if (err)
1022 			goto done;
1023 		ondisk_ref_namespace = buf;
1024 		while (ondisk_ref_namespace[0] == '/')
1025 			ondisk_ref_namespace++;
1026 		if (strncmp(ondisk_ref_namespace, "refs/", 5) == 0)
1027 			ondisk_ref_namespace += 5;
1028 		else if (strcmp(ondisk_ref_namespace, "refs") == 0)
1029 			ondisk_ref_namespace = "";
1030 	}
1031 
1032 	/* Gather on-disk refs before parsing packed-refs. */
1033 	free(path_refs);
1034 	path_refs = get_refs_dir_path(repo, "");
1035 	if (path_refs == NULL) {
1036 		err = got_error_from_errno("get_refs_dir_path");
1037 		goto done;
1038 	}
1039 	err = gather_on_disk_refs(refs, path_refs,
1040 	    ondisk_ref_namespace ? ondisk_ref_namespace : "", repo,
1041 	    cmp_cb, cmp_arg);
1042 	if (err)
1043 		goto done;
1044 
1045 	/*
1046 	 * The packed-refs file may contain redundant entries, in which
1047 	 * case on-disk refs take precedence.
1048 	 */
1049 	packed_refs_path = got_repo_get_path_packed_refs(repo);
1050 	if (packed_refs_path == NULL) {
1051 		err = got_error_from_errno("got_repo_get_path_packed_refs");
1052 		goto done;
1053 	}
1054 
1055 	f = fopen(packed_refs_path, "re");
1056 	if (f) {
1057 		size_t linesize = 0;
1058 		ssize_t linelen;
1059 		struct stat sb;
1060 
1061 		if (fstat(fileno(f), &sb) == -1) {
1062 			err = got_error_from_errno2("fstat", packed_refs_path);
1063 			goto done;
1064 		}
1065 		for (;;) {
1066 			linelen = getline(&line, &linesize, f);
1067 			if (linelen == -1) {
1068 				if (feof(f))
1069 					break;
1070 				err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1071 				goto done;
1072 			}
1073 			if (linelen > 0 && line[linelen - 1] == '\n')
1074 				line[linelen - 1] = '\0';
1075 			err = parse_packed_ref_line(&ref, NULL, line,
1076 			    sb.st_mtime, got_repo_get_object_format(repo));
1077 			if (err)
1078 				goto done;
1079 			if (ref) {
1080 				if (ref_namespace) {
1081 					const char *name;
1082 					name = got_ref_get_name(ref);
1083 					if (!got_path_is_child(name,
1084 					    ref_namespace,
1085 					    strlen(ref_namespace))) {
1086 						got_ref_close(ref);
1087 						continue;
1088 					}
1089 				}
1090 				err = got_reflist_insert(&new, refs, ref,
1091 				    cmp_cb, cmp_arg);
1092 				if (err || new == NULL /* duplicate */)
1093 					got_ref_close(ref);
1094 				if (err)
1095 					goto done;
1096 			}
1097 		}
1098 	}
1099 done:
1100 	free(packed_refs_path);
1101 	free(abs_namespace);
1102 	free(buf);
1103 	free(line);
1104 	free(path_refs);
1105 	if (f && fclose(f) == EOF && err == NULL)
1106 		err = got_error_from_errno("fclose");
1107 	return err;
1108 }
1109 
1110 void
1111 got_ref_list_free(struct got_reflist_head *refs)
1112 {
1113 	struct got_reflist_entry *re;
1114 
1115 	while ((re = TAILQ_FIRST(refs))) {
1116 		TAILQ_REMOVE(refs, re, entry);
1117 		got_ref_close(re->ref);
1118 		free(re);
1119 	}
1120 }
1121 
1122 int
1123 got_ref_is_symbolic(struct got_reference *ref)
1124 {
1125 	return (ref->flags & GOT_REF_IS_SYMBOLIC);
1126 }
1127 
1128 const struct got_error *
1129 got_ref_change_ref(struct got_reference *ref, struct got_object_id *id)
1130 {
1131 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
1132 		return got_error(GOT_ERR_BAD_REF_TYPE);
1133 
1134 	memcpy(&ref->ref.ref.id, id, sizeof(ref->ref.ref.id));
1135 	return NULL;
1136 }
1137 
1138 const struct got_error *
1139 got_ref_change_symref(struct got_reference *ref, const char *refname)
1140 {
1141 	char *new_name;
1142 
1143 	if ((ref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1144 		return got_error(GOT_ERR_BAD_REF_TYPE);
1145 
1146 	new_name = strdup(refname);
1147 	if (new_name == NULL)
1148 		return got_error_from_errno("strdup");
1149 
1150 	free(ref->ref.symref.ref);
1151 	ref->ref.symref.ref = new_name;
1152 	return NULL;
1153 }
1154 
1155 const struct got_error *
1156 got_ref_change_symref_to_ref(struct got_reference *symref,
1157     struct got_object_id *id)
1158 {
1159 	if ((symref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1160 		return got_error(GOT_ERR_BAD_REF_TYPE);
1161 
1162 	symref->ref.ref.name = symref->ref.symref.name;
1163 	memcpy(&symref->ref.ref.id, id, sizeof(symref->ref.ref.id));
1164 	symref->flags &= ~GOT_REF_IS_SYMBOLIC;
1165 	return NULL;
1166 }
1167 
1168 const struct got_error *
1169 got_ref_write(struct got_reference *ref, struct got_repository *repo)
1170 {
1171 	const struct got_error *err = NULL, *unlock_err = NULL;
1172 	const char *name = got_ref_get_name(ref);
1173 	char *path_refs = NULL, *path = NULL, *tmppath = NULL;
1174 	struct got_lockfile *lf = NULL;
1175 	FILE *f = NULL;
1176 	size_t n;
1177 	struct stat sb;
1178 
1179 	path_refs = get_refs_dir_path(repo, name);
1180 	if (path_refs == NULL) {
1181 		err = got_error_from_errno2("get_refs_dir_path", name);
1182 		goto done;
1183 	}
1184 
1185 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1186 		err = got_error_from_errno("asprintf");
1187 		goto done;
1188 	}
1189 
1190 	err = got_opentemp_named(&tmppath, &f, path, "");
1191 	if (err) {
1192 		char *parent;
1193 		if (!(err->code == GOT_ERR_ERRNO && errno == ENOENT))
1194 			goto done;
1195 		err = got_path_dirname(&parent, path);
1196 		if (err)
1197 			goto done;
1198 		err = got_path_mkdir(parent);
1199 		free(parent);
1200 		if (err)
1201 			goto done;
1202 		err = got_opentemp_named(&tmppath, &f, path, "");
1203 		if (err)
1204 			goto done;
1205 	}
1206 
1207 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
1208 		n = fprintf(f, "ref: %s\n", ref->ref.symref.ref);
1209 		if (n != strlen(ref->ref.symref.ref) + 6) {
1210 			err = got_ferror(f, GOT_ERR_IO);
1211 			goto done;
1212 		}
1213 	} else {
1214 		char *hex;
1215 		size_t len;
1216 
1217 		err = got_object_id_str(&hex, &ref->ref.ref.id);
1218 		if (err)
1219 			goto done;
1220 		len = strlen(hex);
1221 		n = fprintf(f, "%s\n", hex);
1222 		free(hex);
1223 		if (n != len + 1) {
1224 			err = got_ferror(f, GOT_ERR_IO);
1225 			goto done;
1226 		}
1227 	}
1228 
1229 	if (ref->lf == NULL) {
1230 		err = got_lockfile_lock(&lf, path, -1);
1231 		if (err)
1232 			goto done;
1233 	}
1234 
1235 	/* XXX: check if old content matches our expectations? */
1236 
1237 	if (stat(path, &sb) != 0) {
1238 		if (errno != ENOENT) {
1239 			err = got_error_from_errno2("stat", path);
1240 			goto done;
1241 		}
1242 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
1243 	}
1244 
1245 	if (fchmod(fileno(f), sb.st_mode) != 0) {
1246 		err = got_error_from_errno2("fchmod", tmppath);
1247 		goto done;
1248 	}
1249 
1250 	if (rename(tmppath, path) != 0) {
1251 		err = got_error_from_errno3("rename", tmppath, path);
1252 		goto done;
1253 	}
1254 	free(tmppath);
1255 	tmppath = NULL;
1256 
1257 	if (stat(path, &sb) == -1) {
1258 		err = got_error_from_errno2("stat", path);
1259 		goto done;
1260 	}
1261 	ref->mtime = sb.st_mtime;
1262 done:
1263 	if (ref->lf == NULL && lf)
1264 		unlock_err = got_lockfile_unlock(lf, -1);
1265 	if (f) {
1266 		if (fclose(f) == EOF && err == NULL)
1267 			err = got_error_from_errno("fclose");
1268 	}
1269 	free(path_refs);
1270 	free(path);
1271 	if (tmppath) {
1272 		if (unlink(tmppath) == -1 && err == NULL)
1273 			err = got_error_from_errno2("unlink", tmppath);
1274 		free(tmppath);
1275 	}
1276 	return err ? err : unlock_err;
1277 }
1278 
1279 static const struct got_error *
1280 delete_packed_ref(struct got_reference *delref, struct got_repository *repo)
1281 {
1282 	const struct got_error *err = NULL, *unlock_err = NULL;
1283 	struct got_lockfile *lf = NULL;
1284 	FILE *f = NULL, *tmpf = NULL;
1285 	char *line = NULL, *packed_refs_path, *tmppath = NULL;
1286 	size_t linesize = 0;
1287 	struct got_reflist_head refs;
1288 	int found_delref = 0;
1289 
1290 	/* The packed-refs file does not cotain symbolic references. */
1291 	if (delref->flags & GOT_REF_IS_SYMBOLIC)
1292 		return got_error(GOT_ERR_BAD_REF_DATA);
1293 
1294 	TAILQ_INIT(&refs);
1295 
1296 	packed_refs_path = got_repo_get_path_packed_refs(repo);
1297 	if (packed_refs_path == NULL)
1298 		return got_error_from_errno("got_repo_get_path_packed_refs");
1299 
1300 	err = got_opentemp_named(&tmppath, &tmpf, packed_refs_path, "");
1301 	if (err)
1302 		goto done;
1303 
1304 	if (delref->lf == NULL) {
1305 		err = got_lockfile_lock(&lf, packed_refs_path, -1);
1306 		if (err)
1307 			goto done;
1308 	}
1309 
1310 	f = fopen(packed_refs_path, "re");
1311 	if (f == NULL) {
1312 		err = got_error_from_errno2("fopen", packed_refs_path);
1313 		goto done;
1314 	}
1315 	for (;;) {
1316 		ssize_t linelen;
1317 		struct got_reference *ref;
1318 		struct got_reflist_entry *new;
1319 
1320 		linelen = getline(&line, &linesize, f);
1321 		if (linelen == -1) {
1322 			if (feof(f))
1323 				break;
1324 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1325 			goto done;
1326 		}
1327 		if (linelen > 0 && line[linelen - 1] == '\n')
1328 			line[linelen - 1] = '\0';
1329 		err = parse_packed_ref_line(&ref, NULL, line, 0,
1330 		    got_repo_get_object_format(repo));
1331 		if (err)
1332 			goto done;
1333 		if (ref == NULL)
1334 			continue;
1335 
1336 		if (strcmp(ref->ref.ref.name, delref->ref.ref.name) == 0 &&
1337 		    got_object_id_cmp(&ref->ref.ref.id,
1338 		    &delref->ref.ref.id) == 0) {
1339 			found_delref = 1;
1340 			got_ref_close(ref);
1341 			continue;
1342 		}
1343 
1344 		err = got_reflist_insert(&new, &refs, ref,
1345 		    got_ref_cmp_by_name, NULL);
1346 		if (err || new == NULL /* duplicate */)
1347 			got_ref_close(ref);
1348 		if (err)
1349 			goto done;
1350 	}
1351 
1352 	if (found_delref) {
1353 		struct got_reflist_entry *re;
1354 		size_t n;
1355 		struct stat sb;
1356 
1357 		n = fprintf(tmpf, "%s\n", GOT_PACKED_REFS_HEADER);
1358 		if (n != sizeof(GOT_PACKED_REFS_HEADER)) {
1359 			err = got_ferror(f, GOT_ERR_IO);
1360 			goto done;
1361 		}
1362 
1363 		TAILQ_FOREACH(re, &refs, entry) {
1364 			char *hex;
1365 			size_t len;
1366 
1367 			err = got_object_id_str(&hex, &re->ref->ref.ref.id);
1368 			if (err)
1369 				goto done;
1370 			len = strlen(hex);
1371 			n = fprintf(tmpf, "%s ", hex);
1372 			free(hex);
1373 			if (n != len + 1) {
1374 				err = got_ferror(f, GOT_ERR_IO);
1375 				goto done;
1376 			}
1377 
1378 			n = fprintf(tmpf, "%s\n", re->ref->ref.ref.name);
1379 			if (n != strlen(re->ref->ref.ref.name) + 1) {
1380 				err = got_ferror(f, GOT_ERR_IO);
1381 				goto done;
1382 			}
1383 		}
1384 
1385 		if (fflush(tmpf) != 0) {
1386 			err = got_error_from_errno("fflush");
1387 			goto done;
1388 		}
1389 
1390 		if (fstat(fileno(f), &sb) != 0) {
1391 			if (errno != ENOENT) {
1392 				err = got_error_from_errno2("fstat",
1393 				    packed_refs_path);
1394 				goto done;
1395 			}
1396 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1397 		}
1398 
1399 		if (fchmod(fileno(tmpf), sb.st_mode) != 0) {
1400 			err = got_error_from_errno2("fchmod", tmppath);
1401 			goto done;
1402 		}
1403 
1404 		if (rename(tmppath, packed_refs_path) != 0) {
1405 			err = got_error_from_errno3("rename", tmppath,
1406 			    packed_refs_path);
1407 			goto done;
1408 		}
1409 		free(tmppath);
1410 		tmppath = NULL;
1411 	}
1412 done:
1413 	if (delref->lf == NULL && lf)
1414 		unlock_err = got_lockfile_unlock(lf, -1);
1415 	if (f) {
1416 		if (fclose(f) == EOF && err == NULL)
1417 			err = got_error_from_errno("fclose");
1418 	}
1419 	if (tmppath && unlink(tmppath) == -1 && err == NULL)
1420 		err = got_error_from_errno2("unlink", tmppath);
1421 	if (tmpf && fclose(tmpf) == EOF && err == NULL)
1422 		err = got_error_from_errno("fclose");
1423 	free(tmppath);
1424 	free(packed_refs_path);
1425 	free(line);
1426 	got_ref_list_free(&refs);
1427 	return err ? err : unlock_err;
1428 }
1429 
1430 static const struct got_error *
1431 delete_loose_ref(struct got_reference *ref, struct got_repository *repo)
1432 {
1433 	const struct got_error *err = NULL, *unlock_err = NULL;
1434 	const char *name = got_ref_get_name(ref);
1435 	char *path_refs = NULL, *path = NULL;
1436 	struct got_lockfile *lf = NULL;
1437 
1438 	path_refs = get_refs_dir_path(repo, name);
1439 	if (path_refs == NULL) {
1440 		err = got_error_from_errno2("get_refs_dir_path", name);
1441 		goto done;
1442 	}
1443 
1444 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1445 		err = got_error_from_errno("asprintf");
1446 		goto done;
1447 	}
1448 
1449 	if (ref->lf == NULL) {
1450 		err = got_lockfile_lock(&lf, path, -1);
1451 		if (err)
1452 			goto done;
1453 	}
1454 
1455 	/* XXX: check if old content matches our expectations? */
1456 
1457 	if (unlink(path) == -1)
1458 		err = got_error_from_errno2("unlink", path);
1459 done:
1460 	if (ref->lf == NULL && lf)
1461 		unlock_err = got_lockfile_unlock(lf, -1);
1462 
1463 	free(path_refs);
1464 	free(path);
1465 	return err ? err : unlock_err;
1466 }
1467 
1468 const struct got_error *
1469 got_ref_delete(struct got_reference *ref, struct got_repository *repo)
1470 {
1471 	const struct got_error *err = NULL;
1472 	struct got_reference *ref2;
1473 
1474 	if (ref->flags & GOT_REF_IS_PACKED) {
1475 		err = delete_packed_ref(ref, repo);
1476 		if (err)
1477 			return err;
1478 
1479 		err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1480 		if (err) {
1481 			if (err->code == GOT_ERR_NOT_REF)
1482 				return NULL;
1483 			return err;
1484 		}
1485 
1486 		err = delete_loose_ref(ref2, repo);
1487 		got_ref_close(ref2);
1488 		return err;
1489 	} else {
1490 		err = delete_loose_ref(ref, repo);
1491 		if (err)
1492 			return err;
1493 
1494 		err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1495 		if (err) {
1496 			if (err->code == GOT_ERR_NOT_REF)
1497 				return NULL;
1498 			return err;
1499 		}
1500 
1501 		err = delete_packed_ref(ref2, repo);
1502 		got_ref_close(ref2);
1503 		return err;
1504 	}
1505 }
1506 
1507 const struct got_error *
1508 got_ref_unlock(struct got_reference *ref)
1509 {
1510 	const struct got_error *err;
1511 	err = got_lockfile_unlock(ref->lf, -1);
1512 	ref->lf = NULL;
1513 	return err;
1514 }
1515 
1516 struct got_reflist_object_id_map {
1517 	struct got_object_idset *idset;
1518 };
1519 
1520 struct got_reflist_object_id_map_entry {
1521 	struct got_reflist_head refs;
1522 };
1523 
1524 static const struct got_error *
1525 add_object_id_map_entry(struct got_object_idset *idset,
1526     struct got_object_id *id, struct got_reflist_entry *re)
1527 {
1528 	const struct got_error *err = NULL;
1529 	struct got_reflist_object_id_map_entry *ent;
1530 	struct got_reflist_entry *new;
1531 
1532 	ent = got_object_idset_get(idset, id);
1533 	if (ent == NULL) {
1534 		ent = malloc(sizeof(*ent));
1535 		if (ent == NULL)
1536 			return got_error_from_errno("malloc");
1537 
1538 		TAILQ_INIT(&ent->refs);
1539 		err = got_object_idset_add(idset, id, ent);
1540 		if (err) {
1541 			free(ent);
1542 			return err;
1543 		}
1544 	}
1545 
1546 	err = got_reflist_entry_dup(&new, re);
1547 	if (err)
1548 		return err;
1549 
1550 	TAILQ_INSERT_TAIL(&ent->refs, new, entry);
1551 	return NULL;
1552 }
1553 
1554 const struct got_error *
1555 got_reflist_object_id_map_create(struct got_reflist_object_id_map **map,
1556     struct got_reflist_head *refs, struct got_repository *repo)
1557 {
1558 	const struct got_error *err = NULL;
1559 	struct got_object_idset *idset;
1560 	struct got_object_id *id = NULL;
1561 	struct got_reflist_entry *re;
1562 
1563 	idset = got_object_idset_alloc();
1564 	if (idset == NULL)
1565 		return got_error_from_errno("got_object_idset_alloc");
1566 
1567 	*map = malloc(sizeof(**map));
1568 	if (*map == NULL) {
1569 		got_object_idset_free(idset);
1570 		return got_error_from_errno("malloc");
1571 	}
1572 	(*map)->idset = idset;
1573 
1574 	TAILQ_FOREACH(re, refs, entry) {
1575 		struct got_tag_object *tag = NULL;
1576 
1577 		err = got_ref_resolve(&id, repo, re->ref);
1578 		if (err)
1579 			goto done;
1580 
1581 		err = add_object_id_map_entry(idset, id, re);
1582 		if (err)
1583 			goto done;
1584 
1585 		if (strstr(got_ref_get_name(re->ref), "/tags/") == NULL) {
1586 			free(id);
1587 			id = NULL;
1588 			continue;
1589 		}
1590 
1591 		err = got_object_open_as_tag(&tag, repo, id);
1592 		if (err) {
1593 			if (err->code != GOT_ERR_OBJ_TYPE)
1594 				goto done;
1595 			/* Ref points at something other than a tag. */
1596 			err = NULL;
1597 			tag = NULL;
1598 			free(id);
1599 			id = NULL;
1600 			continue;
1601 		}
1602 
1603 		err = add_object_id_map_entry(idset,
1604 		    got_object_tag_get_object_id(tag), re);
1605 		got_object_tag_close(tag);
1606 		if (err)
1607 			goto done;
1608 
1609 		free(id);
1610 		id = NULL;
1611 	}
1612 done:
1613 	free(id);
1614 	if (err) {
1615 		got_reflist_object_id_map_free(*map);
1616 		*map = NULL;
1617 	}
1618 	return err;
1619 }
1620 
1621 struct got_reflist_head *
1622 got_reflist_object_id_map_lookup(struct got_reflist_object_id_map *map,
1623     struct got_object_id *id)
1624 {
1625 	struct got_reflist_object_id_map_entry *ent;
1626 	ent = got_object_idset_get(map->idset, id);
1627 	if (ent)
1628 		return &ent->refs;
1629 	return NULL;
1630 }
1631 
1632 static const struct got_error *
1633 free_id_map_entry(struct got_object_id *id, void *data, void *arg)
1634 {
1635 	struct got_reflist_object_id_map_entry *ent = data;
1636 
1637 	got_ref_list_free(&ent->refs);
1638 	free(ent);
1639 	return NULL;
1640 }
1641 
1642 void
1643 got_reflist_object_id_map_free(struct got_reflist_object_id_map *map)
1644 {
1645 	got_object_idset_for_each(map->idset, free_id_map_entry, NULL);
1646 	got_object_idset_free(map->idset);
1647 	free(map);
1648 }