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Date:: Sat Feb 4 14:00:31 2023 UTC
Message:: parse_ref_line: parse sha256 hashes
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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)
157 {
158 	struct got_object_id id;
159 
160 	memset(&id, 0, sizeof(id));
161 
162 	if (strncmp(line, "ref: ", 5) == 0) {
163 		line += 5;
164 		return parse_symref(ref, name, line);
165 	}
166 
167 	if (got_parse_sha256_digest(id.hash, line))
168 		id.algo = GOT_HASH_SHA256;
169 	else if (got_parse_sha1_digest(id.hash, line))
170 		id.algo = GOT_HASH_SHA1;
171 	else
172 		return got_error(GOT_ERR_BAD_REF_DATA);
173 
174 	return alloc_ref(ref, name, &id, 0, mtime);
175 }
176 
177 static const struct got_error *
178 parse_ref_file(struct got_reference **ref, const char *name,
179     const char *absname, const char *abspath, int lock)
180 {
181 	const struct got_error *err = NULL;
182 	FILE *f;
183 	char *line = NULL;
184 	size_t linesize = 0;
185 	ssize_t linelen;
186 	struct got_lockfile *lf = NULL;
187 	struct stat sb;
188 
189 	if (lock) {
190 		err = got_lockfile_lock(&lf, abspath, -1);
191 		if (err) {
192 			if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
193 				err = got_error_not_ref(name);
194 			return err;
195 		}
196 	}
197 
198 	f = fopen(abspath, "rbe");
199 	if (f == NULL) {
200 		if (errno != ENOTDIR && errno != ENOENT)
201 			err = got_error_from_errno2("fopen", abspath);
202 		else
203 			err = got_error_not_ref(name);
204 		if (lock)
205 			got_lockfile_unlock(lf, -1);
206 		return err;
207 	}
208 	if (fstat(fileno(f), &sb) == -1) {
209 		err = got_error_from_errno2("fstat", abspath);
210 		goto done;
211 	}
212 
213 	linelen = getline(&line, &linesize, f);
214 	if (linelen == -1) {
215 		if (feof(f))
216 			err = NULL; /* ignore empty files (could be locks) */
217 		else {
218 			if (errno == EISDIR)
219 				err = got_error(GOT_ERR_NOT_REF);
220 			else if (ferror(f))
221 				err = got_ferror(f, GOT_ERR_IO);
222 			else
223 				err = got_error_from_errno2("getline", abspath);
224 		}
225 		if (lock)
226 			got_lockfile_unlock(lf, -1);
227 		goto done;
228 	}
229 	while (linelen > 0 && line[linelen - 1] == '\n') {
230 		line[linelen - 1] = '\0';
231 		linelen--;
232 	}
233 
234 	err = parse_ref_line(ref, absname, line, sb.st_mtime);
235 	if (lock) {
236 		if (err)
237 			got_lockfile_unlock(lf, -1);
238 		else {
239 			if (*ref)
240 				(*ref)->lf = lf;
241 			else
242 				got_lockfile_unlock(lf, -1);
243 		}
244 	}
245 done:
246 	free(line);
247 	if (fclose(f) == EOF && err == NULL) {
248 		err = got_error_from_errno("fclose");
249 		if (*ref) {
250 			if (lock)
251 				got_ref_unlock(*ref);
252 			got_ref_close(*ref);
253 			*ref = NULL;
254 		}
255 	}
256 	return err;
257 }
258 
259 static int
260 is_well_known_ref(const char *refname)
261 {
262 	return (strcmp(refname, GOT_REF_HEAD) == 0 ||
263 	    strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
264 	    strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
265 	    strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
266 }
267 
268 static char *
269 get_refs_dir_path(struct got_repository *repo, const char *refname)
270 {
271 	if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
272 		return strdup(got_repo_get_path_git_dir(repo));
273 
274 	return got_repo_get_path_refs(repo);
275 }
276 
277 const struct got_error *
278 got_ref_alloc(struct got_reference **ref, const char *name,
279     struct got_object_id *id)
280 {
281 	if (!got_ref_name_is_valid(name))
282 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
283 
284 	return alloc_ref(ref, name, id, 0, 0);
285 }
286 
287 const struct got_error *
288 got_ref_alloc_symref(struct got_reference **ref, const char *name,
289 	struct got_reference *target_ref)
290 {
291 	if (!got_ref_name_is_valid(name))
292 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
293 
294 	return alloc_symref(ref, name, got_ref_get_name(target_ref), 0);
295 }
296 
297 static const struct got_error *
298 parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
299     const char *line, time_t mtime)
300 {
301 	struct got_object_id id;
302 	const char *name;
303 
304 	*ref = NULL;
305 
306 	if (line[0] == '#' || line[0] == '^')
307 		return NULL;
308 
309 	if (!got_parse_sha1_digest(id.hash, line))
310 		return got_error(GOT_ERR_BAD_REF_DATA);
311 
312 	if (abs_refname) {
313 		if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
314 			return NULL;
315 		name = abs_refname;
316 	} else
317 		name = line + SHA1_DIGEST_STRING_LENGTH;
318 
319 	return alloc_ref(ref, name, &id, GOT_REF_IS_PACKED, mtime);
320 }
321 
322 static const struct got_error *
323 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
324     int nsubdirs, const char *refname, time_t mtime)
325 {
326 	const struct got_error *err = NULL;
327 	char *abs_refname;
328 	char *line = NULL;
329 	size_t linesize = 0;
330 	ssize_t linelen;
331 	int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
332 
333 	*ref = NULL;
334 
335 	if (ref_is_absolute)
336 		abs_refname = (char *)refname;
337 	do {
338 		linelen = getline(&line, &linesize, f);
339 		if (linelen == -1) {
340 			if (feof(f))
341 				break;
342 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
343 			break;
344 		}
345 		if (linelen > 0 && line[linelen - 1] == '\n')
346 			line[linelen - 1] = '\0';
347 		for (i = 0; i < nsubdirs; i++) {
348 			if (!ref_is_absolute &&
349 			    asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
350 			    refname) == -1)
351 				return got_error_from_errno("asprintf");
352 			err = parse_packed_ref_line(ref, abs_refname, line,
353 			    mtime);
354 			if (!ref_is_absolute)
355 				free(abs_refname);
356 			if (err || *ref != NULL)
357 				break;
358 		}
359 		if (err)
360 			break;
361 	} while (*ref == NULL);
362 	free(line);
363 
364 	return err;
365 }
366 
367 static const struct got_error *
368 open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
369     const char *name, int lock)
370 {
371 	const struct got_error *err = NULL;
372 	char *path = NULL;
373 	char *absname = NULL;
374 	int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
375 	int ref_is_well_known = (subdir[0] == '\0' && is_well_known_ref(name));
376 
377 	*ref = NULL;
378 
379 	if (!got_ref_name_is_valid(name))
380 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
381 
382 	if (ref_is_absolute || ref_is_well_known) {
383 		if (asprintf(&path, "%s/%s", path_refs, name) == -1)
384 			return got_error_from_errno("asprintf");
385 		absname = (char *)name;
386 	} else {
387 		if (asprintf(&path, "%s/%s%s%s", path_refs, subdir,
388 		    subdir[0] ? "/" : "", name) == -1)
389 			return got_error_from_errno("asprintf");
390 
391 		if (asprintf(&absname, "refs/%s%s%s",
392 		    subdir, subdir[0] ? "/" : "", name) == -1) {
393 			err = got_error_from_errno("asprintf");
394 			goto done;
395 		}
396 	}
397 
398 	err = parse_ref_file(ref, name, absname, path, lock);
399 done:
400 	if (!ref_is_absolute && !ref_is_well_known)
401 		free(absname);
402 	free(path);
403 	return err;
404 }
405 
406 const struct got_error *
407 got_ref_open(struct got_reference **ref, struct got_repository *repo,
408     const char *refname, int lock)
409 {
410 	const struct got_error *err = NULL;
411 	char *packed_refs_path = NULL, *path_refs = NULL;
412 	const char *subdirs[] = {
413 	    GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
414 	};
415 	size_t i;
416 	int well_known = is_well_known_ref(refname);
417 	struct got_lockfile *lf = NULL;
418 
419 	*ref = NULL;
420 
421 	path_refs = get_refs_dir_path(repo, refname);
422 	if (path_refs == NULL) {
423 		err = got_error_from_errno2("get_refs_dir_path", refname);
424 		goto done;
425 	}
426 
427 	if (well_known) {
428 		err = open_ref(ref, path_refs, "", refname, lock);
429 	} else {
430 		FILE *f;
431 
432 		/* Search on-disk refs before packed refs! */
433 		for (i = 0; i < nitems(subdirs); i++) {
434 			err = open_ref(ref, path_refs, subdirs[i], refname,
435 			    lock);
436 			if ((err && err->code != GOT_ERR_NOT_REF) || *ref)
437 				goto done;
438 		}
439 
440 		packed_refs_path = got_repo_get_path_packed_refs(repo);
441 		if (packed_refs_path == NULL) {
442 			err = got_error_from_errno(
443 			    "got_repo_get_path_packed_refs");
444 			goto done;
445 		}
446 
447 		if (lock) {
448 			err = got_lockfile_lock(&lf, packed_refs_path, -1);
449 			if (err)
450 				goto done;
451 		}
452 		f = fopen(packed_refs_path, "rbe");
453 		if (f != NULL) {
454 			struct stat sb;
455 			if (fstat(fileno(f), &sb) == -1) {
456 				err = got_error_from_errno2("fstat",
457 				    packed_refs_path);
458 				goto done;
459 			}
460 			err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
461 			    refname, sb.st_mtime);
462 			if (!err) {
463 				if (fclose(f) == EOF) {
464 					err = got_error_from_errno("fclose");
465 					got_ref_close(*ref);
466 					*ref = NULL;
467 				} else if (*ref)
468 					(*ref)->lf = lf;
469 			}
470 		}
471 	}
472 done:
473 	if (!err && *ref == NULL)
474 		err = got_error_not_ref(refname);
475 	if (err && lf)
476 		got_lockfile_unlock(lf, -1);
477 	free(packed_refs_path);
478 	free(path_refs);
479 	return err;
480 }
481 
482 void
483 got_ref_close(struct got_reference *ref)
484 {
485 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
486 		free(ref->ref.symref.name);
487 		free(ref->ref.symref.ref);
488 	} else
489 		free(ref->ref.ref.name);
490 	free(ref);
491 }
492 
493 struct got_reference *
494 got_ref_dup(struct got_reference *ref)
495 {
496 	struct got_reference *ret;
497 
498 	ret = calloc(1, sizeof(*ret));
499 	if (ret == NULL)
500 		return NULL;
501 
502 	ret->flags = ref->flags;
503 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
504 		ret->ref.symref.name = strdup(ref->ref.symref.name);
505 		if (ret->ref.symref.name == NULL) {
506 			free(ret);
507 			return NULL;
508 		}
509 		ret->ref.symref.ref = strdup(ref->ref.symref.ref);
510 		if (ret->ref.symref.ref == NULL) {
511 			free(ret->ref.symref.name);
512 			free(ret);
513 			return NULL;
514 		}
515 	} else {
516 		ret->ref.ref.name = strdup(ref->ref.ref.name);
517 		if (ret->ref.ref.name == NULL) {
518 			free(ret);
519 			return NULL;
520 		}
521 		memcpy(&ret->ref.ref.id, &ref->ref.ref.id,
522 		    sizeof(ret->ref.ref.id));
523 	}
524 
525 	return ret;
526 }
527 
528 const struct got_error *
529 got_reflist_entry_dup(struct got_reflist_entry **newp,
530     struct got_reflist_entry *re)
531 {
532 	const struct got_error *err = NULL;
533 	struct got_reflist_entry *new;
534 
535 	*newp = NULL;
536 
537 	new = malloc(sizeof(*new));
538 	if (new == NULL)
539 		return got_error_from_errno("malloc");
540 
541 	new->ref = got_ref_dup(re->ref);
542 	if (new->ref == NULL) {
543 		err = got_error_from_errno("got_ref_dup");
544 		free(new);
545 		return err;
546 	}
547 
548 	*newp = new;
549 	return NULL;
550 }
551 
552 const struct got_error *
553 got_ref_resolve_symbolic(struct got_reference **resolved,
554     struct got_repository *repo, struct got_reference *ref)
555 {
556 	struct got_reference *nextref;
557 	const struct got_error *err;
558 
559 	err = got_ref_open(&nextref, repo, ref->ref.symref.ref, 0);
560 	if (err)
561 		return err;
562 
563 	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
564 		err = got_ref_resolve_symbolic(resolved, repo, nextref);
565 	else
566 		*resolved = got_ref_dup(nextref);
567 
568 	got_ref_close(nextref);
569 	return err;
570 }
571 
572 static const struct got_error *
573 ref_resolve(struct got_object_id **id, struct got_repository *repo,
574     struct got_reference *ref, int recursion)
575 {
576 	const struct got_error *err;
577 
578 	if (recursion <= 0)
579 		return got_error_msg(GOT_ERR_RECURSION,
580 		    "reference recursion limit reached");
581 
582 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
583 		struct got_reference *resolved = NULL;
584 		err = got_ref_resolve_symbolic(&resolved, repo, ref);
585 		if (err == NULL)
586 			err = ref_resolve(id, repo, resolved, --recursion);
587 		if (resolved)
588 			got_ref_close(resolved);
589 		return err;
590 	}
591 
592 	*id = calloc(1, sizeof(**id));
593 	if (*id == NULL)
594 		return got_error_from_errno("calloc");
595 	memcpy(*id, &ref->ref.ref.id, sizeof(**id));
596 	return NULL;
597 }
598 
599 const struct got_error *
600 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
601     struct got_reference *ref)
602 {
603 	return ref_resolve(id, repo, ref, GOT_REF_RECURSE_MAX);
604 }
605 
606 char *
607 got_ref_to_str(struct got_reference *ref)
608 {
609 	char *str;
610 
611 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
612 		return strdup(ref->ref.symref.ref);
613 
614 	if (got_object_id_str(&str, &ref->ref.ref.id) != NULL)
615 		return NULL;
616 
617 	return str;
618 }
619 
620 const char *
621 got_ref_get_name(struct got_reference *ref)
622 {
623 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
624 		return ref->ref.symref.name;
625 
626 	return ref->ref.ref.name;
627 }
628 
629 const char *
630 got_ref_get_symref_target(struct got_reference *ref)
631 {
632 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
633 		return ref->ref.symref.ref;
634 
635 	return NULL;
636 }
637 
638 time_t
639 got_ref_get_mtime(struct got_reference *ref)
640 {
641 	return ref->mtime;
642 }
643 
644 const struct got_error *
645 got_ref_cmp_by_name(void *arg, int *cmp, struct got_reference *re1,
646     struct got_reference* re2)
647 {
648 	const char *name1 = got_ref_get_name(re1);
649 	const char *name2 = got_ref_get_name(re2);
650 
651 	*cmp = got_path_cmp(name1, name2, strlen(name1), strlen(name2));
652 	return NULL;
653 }
654 
655 const struct got_error *
656 got_ref_cmp_tags(void *arg, int *cmp, struct got_reference *ref1,
657     struct got_reference *ref2)
658 {
659 	const struct got_error *err = NULL;
660 	struct got_repository *repo = arg;
661 	struct got_object_id *id1, *id2 = NULL;
662 	struct got_tag_object *tag1 = NULL, *tag2 = NULL;
663 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
664 	time_t time1, time2;
665 
666 	*cmp = 0;
667 
668 	err = got_ref_resolve(&id1, repo, ref1);
669 	if (err)
670 		return err;
671 	err = got_object_open_as_tag(&tag1, repo, id1);
672 	if (err) {
673 		if (err->code != GOT_ERR_OBJ_TYPE)
674 			goto done;
675 		/* "lightweight" tag */
676 		err = got_object_open_as_commit(&commit1, repo, id1);
677 		if (err)
678 			goto done;
679 		time1 = got_object_commit_get_committer_time(commit1);
680 	} else
681 		time1 = got_object_tag_get_tagger_time(tag1);
682 
683 	err = got_ref_resolve(&id2, repo, ref2);
684 	if (err)
685 		goto done;
686 	err = got_object_open_as_tag(&tag2, repo, id2);
687 	if (err) {
688 		if (err->code != GOT_ERR_OBJ_TYPE)
689 			goto done;
690 		/* "lightweight" tag */
691 		err = got_object_open_as_commit(&commit2, repo, id2);
692 		if (err)
693 			goto done;
694 		time2 = got_object_commit_get_committer_time(commit2);
695 	} else
696 		time2 = got_object_tag_get_tagger_time(tag2);
697 
698 	/* Put latest tags first. */
699 	if (time1 < time2)
700 		*cmp = 1;
701 	else if (time1 > time2)
702 		*cmp = -1;
703 	else
704 		err = got_ref_cmp_by_name(NULL, cmp, ref2, ref1);
705 done:
706 	free(id1);
707 	free(id2);
708 	if (tag1)
709 		got_object_tag_close(tag1);
710 	if (tag2)
711 		got_object_tag_close(tag2);
712 	if (commit1)
713 		got_object_commit_close(commit1);
714 	if (commit2)
715 		got_object_commit_close(commit2);
716 	return err;
717 }
718 
719 static const struct got_error *
720 get_committer_time(struct got_reference *ref, struct got_repository *repo)
721 {
722 	const struct got_error *err = NULL;
723 	int obj_type;
724 	struct got_commit_object *commit = NULL;
725 	struct got_tag_object *tag = NULL;
726 	struct got_object_id *id = NULL;
727 
728 	err = got_ref_resolve(&id, repo, ref);
729 	if (err)
730 		return err;
731 
732 	err = got_object_get_type(&obj_type, repo, id);
733 	if (err)
734 		goto done;
735 
736 	switch (obj_type) {
737 	case GOT_OBJ_TYPE_COMMIT:
738 		err = got_object_open_as_commit(&commit, repo, id);
739 		if (err)
740 			goto done;
741 		ref->committer_time =
742 		    got_object_commit_get_committer_time(commit);
743 		break;
744 	case GOT_OBJ_TYPE_TAG:
745 		err = got_object_open_as_tag(&tag, repo, id);
746 		if (err)
747 			goto done;
748 		ref->committer_time = got_object_tag_get_tagger_time(tag);
749 		break;
750 	default:
751 		/* best effort for other object types */
752 		ref->committer_time = got_ref_get_mtime(ref);
753 		break;
754 	}
755 done:
756 	free(id);
757 	if (commit)
758 		got_object_commit_close(commit);
759 	if (tag)
760 		got_object_tag_close(tag);
761 	return err;
762 }
763 
764 const struct got_error *
765 got_ref_cmp_by_commit_timestamp_descending(void *arg, int *cmp,
766     struct got_reference *ref1, struct got_reference *ref2)
767 {
768 	const struct got_error *err = NULL;
769 	struct got_repository *repo = arg;
770 
771 	*cmp = 0;
772 
773 	if (ref1->committer_time == 0) {
774 		err = get_committer_time(ref1, repo);
775 		if (err)
776 			return err;
777 	}
778 	if (ref2->committer_time == 0) {
779 		err = get_committer_time(ref2, repo);
780 		if (err)
781 			return err;
782 	}
783 
784 	if (ref1->committer_time < ref2->committer_time)
785 		*cmp = 1;
786 	else if (ref2->committer_time < ref1->committer_time)
787 		*cmp = -1;
788 	else
789 		return got_ref_cmp_by_name(arg, cmp, ref1, ref2);
790 
791 	return err;
792 }
793 
794 const struct got_error *
795 got_reflist_insert(struct got_reflist_entry **newp,
796     struct got_reflist_head *refs, struct got_reference *ref,
797     got_ref_cmp_cb cmp_cb, void *cmp_arg)
798 {
799 	const struct got_error *err;
800 	struct got_reflist_entry *new, *re;
801 	int cmp;
802 
803 	*newp = NULL;
804 
805 	if (cmp_cb != got_ref_cmp_by_name && (ref->flags & GOT_REF_IS_PACKED)) {
806 		/*
807 		 * If we are not sorting elements by name then we must still
808 		 * detect collisions between a packed ref and an on-disk ref
809 		 * using the same name. On-disk refs take precedence and are
810 		 * already present on the list before packed refs get added.
811 		 */
812 		TAILQ_FOREACH(re, refs, entry) {
813 			err = got_ref_cmp_by_name(NULL, &cmp, re->ref, ref);
814 			if (err)
815 				return err;
816 			if (cmp == 0)
817 				return NULL;
818 		}
819 	}
820 
821 	new = malloc(sizeof(*new));
822 	if (new == NULL)
823 		return got_error_from_errno("malloc");
824 	new->ref = ref;
825 	*newp = new;
826 
827 	/*
828 	 * We must de-duplicate entries on insert because packed-refs may
829 	 * contain redundant entries. On-disk refs take precedence.
830 	 * This code assumes that on-disk revs are read before packed-refs.
831 	 * We're iterating the list anyway, so insert elements sorted by name.
832 	 *
833 	 * Many callers will provide paths in a somewhat sorted order.
834 	 * Iterating backwards from the tail of the list should be more
835 	 * efficient than traversing through the entire list each time
836 	 * an element is inserted.
837 	 */
838 	re = TAILQ_LAST(refs, got_reflist_head);
839 	while (re) {
840 		err = (*cmp_cb)(cmp_arg, &cmp, re->ref, new->ref);
841 		if (err)
842 			return err;
843 		if (cmp == 0) {
844 			/* duplicate */
845 			free(new);
846 			*newp = NULL;
847 			return NULL;
848 		} else if (cmp < 0) {
849 			TAILQ_INSERT_AFTER(refs, re, new, entry);
850 			return NULL;
851 		}
852 		re = TAILQ_PREV(re, got_reflist_head, entry);
853 	}
854 
855 	TAILQ_INSERT_HEAD(refs, new, entry);
856 	return NULL;
857 }
858 
859 const struct got_error *
860 got_reflist_sort(struct got_reflist_head *refs,
861     got_ref_cmp_cb cmp_cb, void *cmp_arg)
862 {
863 	const struct got_error *err = NULL;
864 	struct got_reflist_entry *re, *tmp, *new;
865 	struct got_reflist_head sorted;
866 
867 	TAILQ_INIT(&sorted);
868 
869 	TAILQ_FOREACH_SAFE(re, refs, entry, tmp) {
870 		struct got_reference *ref = re->ref;
871 		TAILQ_REMOVE(refs, re, entry);
872 		free(re);
873 		err = got_reflist_insert(&new, &sorted, ref, cmp_cb, cmp_arg);
874 		if (err || new == NULL /* duplicate */)
875 			got_ref_close(ref);
876 		if (err)
877 			return err;
878 	}
879 
880 	TAILQ_CONCAT(refs, &sorted, entry);
881 	return NULL;
882 }
883 
884 static const struct got_error *
885 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
886     const char *subdir, struct got_repository *repo,
887     got_ref_cmp_cb cmp_cb, void *cmp_arg)
888 {
889 	const struct got_error *err = NULL;
890 	DIR *d = NULL;
891 	char *path_subdir;
892 
893 	while (subdir[0] == '/')
894 		subdir++;
895 
896 	if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
897 		return got_error_from_errno("asprintf");
898 
899 	d = opendir(path_subdir);
900 	if (d == NULL)
901 		goto done;
902 
903 	for (;;) {
904 		struct dirent *dent;
905 		struct got_reference *ref;
906 		char *child;
907 		int type;
908 
909 		dent = readdir(d);
910 		if (dent == NULL)
911 			break;
912 
913 		if (strcmp(dent->d_name, ".") == 0 ||
914 		    strcmp(dent->d_name, "..") == 0)
915 			continue;
916 
917 		err = got_path_dirent_type(&type, path_subdir, dent);
918 		if (err)
919 			break;
920 
921 		switch (type) {
922 		case DT_REG:
923 			err = open_ref(&ref, path_refs, subdir, dent->d_name,
924 			    0);
925 			if (err)
926 				goto done;
927 			if (ref) {
928 				struct got_reflist_entry *new;
929 				err = got_reflist_insert(&new, refs, ref,
930 				    cmp_cb, cmp_arg);
931 				if (err || new == NULL /* duplicate */)
932 					got_ref_close(ref);
933 				if (err)
934 					goto done;
935 			}
936 			break;
937 		case DT_DIR:
938 			if (asprintf(&child, "%s%s%s", subdir,
939 			    subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
940 				err = got_error_from_errno("asprintf");
941 				break;
942 			}
943 			err = gather_on_disk_refs(refs, path_refs, child, repo,
944 			    cmp_cb, cmp_arg);
945 			free(child);
946 			break;
947 		default:
948 			break;
949 		}
950 	}
951 done:
952 	if (d)
953 		closedir(d);
954 	free(path_subdir);
955 	return err;
956 }
957 
958 const struct got_error *
959 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo,
960     const char *ref_namespace, got_ref_cmp_cb cmp_cb, void *cmp_arg)
961 {
962 	const struct got_error *err;
963 	char *packed_refs_path = NULL, *path_refs = NULL;
964 	char *abs_namespace = NULL, *buf = NULL;
965 	const char *ondisk_ref_namespace = NULL;
966 	char *line = NULL;
967 	FILE *f = NULL;
968 	struct got_reference *ref;
969 	struct got_reflist_entry *new;
970 
971 	if (ref_namespace == NULL || ref_namespace[0] == '\0') {
972 		path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
973 		if (path_refs == NULL) {
974 			err = got_error_from_errno("get_refs_dir_path");
975 			goto done;
976 		}
977 		err = open_ref(&ref, path_refs, "", GOT_REF_HEAD, 0);
978 		if (err)
979 			goto done;
980 		err = got_reflist_insert(&new, refs, ref, cmp_cb, cmp_arg);
981 		if (err || new == NULL /* duplicate */)
982 			got_ref_close(ref);
983 		if (err && err->code != GOT_ERR_NOT_REF)
984 			goto done;
985 	} else {
986 		/* Try listing a single reference. */
987 		const char *refname = ref_namespace;
988 		path_refs = get_refs_dir_path(repo, refname);
989 		if (path_refs == NULL) {
990 			err = got_error_from_errno("get_refs_dir_path");
991 			goto done;
992 		}
993 		err = open_ref(&ref, path_refs, "", refname, 0);
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);
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 		if (err)
1331 			goto done;
1332 		if (ref == NULL)
1333 			continue;
1334 
1335 		if (strcmp(ref->ref.ref.name, delref->ref.ref.name) == 0 &&
1336 		    got_object_id_cmp(&ref->ref.ref.id,
1337 		    &delref->ref.ref.id) == 0) {
1338 			found_delref = 1;
1339 			got_ref_close(ref);
1340 			continue;
1341 		}
1342 
1343 		err = got_reflist_insert(&new, &refs, ref,
1344 		    got_ref_cmp_by_name, NULL);
1345 		if (err || new == NULL /* duplicate */)
1346 			got_ref_close(ref);
1347 		if (err)
1348 			goto done;
1349 	}
1350 
1351 	if (found_delref) {
1352 		struct got_reflist_entry *re;
1353 		size_t n;
1354 		struct stat sb;
1355 
1356 		n = fprintf(tmpf, "%s\n", GOT_PACKED_REFS_HEADER);
1357 		if (n != sizeof(GOT_PACKED_REFS_HEADER)) {
1358 			err = got_ferror(f, GOT_ERR_IO);
1359 			goto done;
1360 		}
1361 
1362 		TAILQ_FOREACH(re, &refs, entry) {
1363 			char *hex;
1364 			size_t len;
1365 
1366 			err = got_object_id_str(&hex, &re->ref->ref.ref.id);
1367 			if (err)
1368 				goto done;
1369 			len = strlen(hex);
1370 			n = fprintf(tmpf, "%s ", hex);
1371 			free(hex);
1372 			if (n != len + 1) {
1373 				err = got_ferror(f, GOT_ERR_IO);
1374 				goto done;
1375 			}
1376 
1377 			n = fprintf(tmpf, "%s\n", re->ref->ref.ref.name);
1378 			if (n != strlen(re->ref->ref.ref.name) + 1) {
1379 				err = got_ferror(f, GOT_ERR_IO);
1380 				goto done;
1381 			}
1382 		}
1383 
1384 		if (fflush(tmpf) != 0) {
1385 			err = got_error_from_errno("fflush");
1386 			goto done;
1387 		}
1388 
1389 		if (fstat(fileno(f), &sb) != 0) {
1390 			if (errno != ENOENT) {
1391 				err = got_error_from_errno2("fstat",
1392 				    packed_refs_path);
1393 				goto done;
1394 			}
1395 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1396 		}
1397 
1398 		if (fchmod(fileno(tmpf), sb.st_mode) != 0) {
1399 			err = got_error_from_errno2("fchmod", tmppath);
1400 			goto done;
1401 		}
1402 
1403 		if (rename(tmppath, packed_refs_path) != 0) {
1404 			err = got_error_from_errno3("rename", tmppath,
1405 			    packed_refs_path);
1406 			goto done;
1407 		}
1408 		free(tmppath);
1409 		tmppath = NULL;
1410 	}
1411 done:
1412 	if (delref->lf == NULL && lf)
1413 		unlock_err = got_lockfile_unlock(lf, -1);
1414 	if (f) {
1415 		if (fclose(f) == EOF && err == NULL)
1416 			err = got_error_from_errno("fclose");
1417 	}
1418 	if (tmppath && unlink(tmppath) == -1 && err == NULL)
1419 		err = got_error_from_errno2("unlink", tmppath);
1420 	if (tmpf && fclose(tmpf) == EOF && err == NULL)
1421 		err = got_error_from_errno("fclose");
1422 	free(tmppath);
1423 	free(packed_refs_path);
1424 	free(line);
1425 	got_ref_list_free(&refs);
1426 	return err ? err : unlock_err;
1427 }
1428 
1429 static const struct got_error *
1430 delete_loose_ref(struct got_reference *ref, struct got_repository *repo)
1431 {
1432 	const struct got_error *err = NULL, *unlock_err = NULL;
1433 	const char *name = got_ref_get_name(ref);
1434 	char *path_refs = NULL, *path = NULL;
1435 	struct got_lockfile *lf = NULL;
1436 
1437 	path_refs = get_refs_dir_path(repo, name);
1438 	if (path_refs == NULL) {
1439 		err = got_error_from_errno2("get_refs_dir_path", name);
1440 		goto done;
1441 	}
1442 
1443 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1444 		err = got_error_from_errno("asprintf");
1445 		goto done;
1446 	}
1447 
1448 	if (ref->lf == NULL) {
1449 		err = got_lockfile_lock(&lf, path, -1);
1450 		if (err)
1451 			goto done;
1452 	}
1453 
1454 	/* XXX: check if old content matches our expectations? */
1455 
1456 	if (unlink(path) == -1)
1457 		err = got_error_from_errno2("unlink", path);
1458 done:
1459 	if (ref->lf == NULL && lf)
1460 		unlock_err = got_lockfile_unlock(lf, -1);
1461 
1462 	free(path_refs);
1463 	free(path);
1464 	return err ? err : unlock_err;
1465 }
1466 
1467 const struct got_error *
1468 got_ref_delete(struct got_reference *ref, struct got_repository *repo)
1469 {
1470 	const struct got_error *err = NULL;
1471 	struct got_reference *ref2;
1472 
1473 	if (ref->flags & GOT_REF_IS_PACKED) {
1474 		err = delete_packed_ref(ref, repo);
1475 		if (err)
1476 			return err;
1477 
1478 		err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1479 		if (err) {
1480 			if (err->code == GOT_ERR_NOT_REF)
1481 				return NULL;
1482 			return err;
1483 		}
1484 
1485 		err = delete_loose_ref(ref2, repo);
1486 		got_ref_close(ref2);
1487 		return err;
1488 	} else {
1489 		err = delete_loose_ref(ref, repo);
1490 		if (err)
1491 			return err;
1492 
1493 		err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1494 		if (err) {
1495 			if (err->code == GOT_ERR_NOT_REF)
1496 				return NULL;
1497 			return err;
1498 		}
1499 
1500 		err = delete_packed_ref(ref2, repo);
1501 		got_ref_close(ref2);
1502 		return err;
1503 	}
1504 }
1505 
1506 const struct got_error *
1507 got_ref_unlock(struct got_reference *ref)
1508 {
1509 	const struct got_error *err;
1510 	err = got_lockfile_unlock(ref->lf, -1);
1511 	ref->lf = NULL;
1512 	return err;
1513 }
1514 
1515 struct got_reflist_object_id_map {
1516 	struct got_object_idset *idset;
1517 };
1518 
1519 struct got_reflist_object_id_map_entry {
1520 	struct got_reflist_head refs;
1521 };
1522 
1523 static const struct got_error *
1524 add_object_id_map_entry(struct got_object_idset *idset,
1525     struct got_object_id *id, struct got_reflist_entry *re)
1526 {
1527 	const struct got_error *err = NULL;
1528 	struct got_reflist_object_id_map_entry *ent;
1529 	struct got_reflist_entry *new;
1530 
1531 	ent = got_object_idset_get(idset, id);
1532 	if (ent == NULL) {
1533 		ent = malloc(sizeof(*ent));
1534 		if (ent == NULL)
1535 			return got_error_from_errno("malloc");
1536 
1537 		TAILQ_INIT(&ent->refs);
1538 		err = got_object_idset_add(idset, id, ent);
1539 		if (err) {
1540 			free(ent);
1541 			return err;
1542 		}
1543 	}
1544 
1545 	err = got_reflist_entry_dup(&new, re);
1546 	if (err)
1547 		return err;
1548 
1549 	TAILQ_INSERT_TAIL(&ent->refs, new, entry);
1550 	return NULL;
1551 }
1552 
1553 const struct got_error *
1554 got_reflist_object_id_map_create(struct got_reflist_object_id_map **map,
1555     struct got_reflist_head *refs, struct got_repository *repo)
1556 {
1557 	const struct got_error *err = NULL;
1558 	struct got_object_idset *idset;
1559 	struct got_object_id *id = NULL;
1560 	struct got_reflist_entry *re;
1561 
1562 	idset = got_object_idset_alloc();
1563 	if (idset == NULL)
1564 		return got_error_from_errno("got_object_idset_alloc");
1565 
1566 	*map = malloc(sizeof(**map));
1567 	if (*map == NULL) {
1568 		got_object_idset_free(idset);
1569 		return got_error_from_errno("malloc");
1570 	}
1571 	(*map)->idset = idset;
1572 
1573 	TAILQ_FOREACH(re, refs, entry) {
1574 		struct got_tag_object *tag = NULL;
1575 
1576 		err = got_ref_resolve(&id, repo, re->ref);
1577 		if (err)
1578 			goto done;
1579 
1580 		err = add_object_id_map_entry(idset, id, re);
1581 		if (err)
1582 			goto done;
1583 
1584 		if (strstr(got_ref_get_name(re->ref), "/tags/") == NULL) {
1585 			free(id);
1586 			id = NULL;
1587 			continue;
1588 		}
1589 
1590 		err = got_object_open_as_tag(&tag, repo, id);
1591 		if (err) {
1592 			if (err->code != GOT_ERR_OBJ_TYPE)
1593 				goto done;
1594 			/* Ref points at something other than a tag. */
1595 			err = NULL;
1596 			tag = NULL;
1597 			free(id);
1598 			id = NULL;
1599 			continue;
1600 		}
1601 
1602 		err = add_object_id_map_entry(idset,
1603 		    got_object_tag_get_object_id(tag), re);
1604 		got_object_tag_close(tag);
1605 		if (err)
1606 			goto done;
1607 
1608 		free(id);
1609 		id = NULL;
1610 	}
1611 done:
1612 	free(id);
1613 	if (err) {
1614 		got_reflist_object_id_map_free(*map);
1615 		*map = NULL;
1616 	}
1617 	return err;
1618 }
1619 
1620 struct got_reflist_head *
1621 got_reflist_object_id_map_lookup(struct got_reflist_object_id_map *map,
1622     struct got_object_id *id)
1623 {
1624 	struct got_reflist_object_id_map_entry *ent;
1625 	ent = got_object_idset_get(map->idset, id);
1626 	if (ent)
1627 		return &ent->refs;
1628 	return NULL;
1629 }
1630 
1631 static const struct got_error *
1632 free_id_map_entry(struct got_object_id *id, void *data, void *arg)
1633 {
1634 	struct got_reflist_object_id_map_entry *ent = data;
1635 
1636 	got_ref_list_free(&ent->refs);
1637 	free(ent);
1638 	return NULL;
1639 }
1640 
1641 void
1642 got_reflist_object_id_map_free(struct got_reflist_object_id_map *map)
1643 {
1644 	got_object_idset_for_each(map->idset, free_id_map_entry, NULL);
1645 	got_object_idset_free(map->idset);
1646 	free(map);
1647 }