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Date:: Sun Sep 5 19:41:03 2021 UTC
Message:: indentation fixes
Actions:: History | Blame | Raw File
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 <ctype.h>
23 #include <dirent.h>
24 #include <limits.h>
25 #include <sha1.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_sha1.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 	u_int8_t sha1[SHA1_DIGEST_LENGTH];
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 
93 static const struct got_error *
94 alloc_ref(struct got_reference **ref, const char *name,
95     struct got_object_id *id, int flags, time_t mtime)
96 {
97 	const struct got_error *err = NULL;
98 
99 	*ref = calloc(1, sizeof(**ref));
100 	if (*ref == NULL)
101 		return got_error_from_errno("calloc");
102 
103 	memcpy((*ref)->ref.ref.sha1, id->sha1, sizeof((*ref)->ref.ref.sha1));
104 	(*ref)->flags = flags;
105 	(*ref)->ref.ref.name = strdup(name);
106 	(*ref)->mtime = mtime;
107 	if ((*ref)->ref.ref.name == NULL) {
108 		err = got_error_from_errno("strdup");
109 		got_ref_close(*ref);
110 		*ref = NULL;
111 	}
112 	return err;
113 }
114 
115 static const struct got_error *
116 alloc_symref(struct got_reference **ref, const char *name,
117     const char *target_ref, int flags)
118 {
119 	const struct got_error *err = NULL;
120 
121 	*ref = calloc(1, sizeof(**ref));
122 	if (*ref == NULL)
123 		return got_error_from_errno("calloc");
124 
125 	(*ref)->flags = GOT_REF_IS_SYMBOLIC | flags;
126 	(*ref)->ref.symref.name = strdup(name);
127 	if ((*ref)->ref.symref.name == NULL) {
128 		err = got_error_from_errno("strdup");
129 		got_ref_close(*ref);
130 		*ref = NULL;
131 		return err;
132 	}
133 	(*ref)->ref.symref.ref = strdup(target_ref);
134 	if ((*ref)->ref.symref.ref == NULL) {
135 		err = got_error_from_errno("strdup");
136 		got_ref_close(*ref);
137 		*ref = NULL;
138 	}
139 	return err;
140 }
141 
142 static const struct got_error *
143 parse_symref(struct got_reference **ref, const char *name, const char *line)
144 {
145 	if (line[0] == '\0')
146 		return got_error(GOT_ERR_BAD_REF_DATA);
147 
148 	return alloc_symref(ref, name, line, 0);
149 }
150 
151 static const struct got_error *
152 parse_ref_line(struct got_reference **ref, const char *name, const char *line,
153     time_t mtime)
154 {
155 	struct got_object_id id;
156 
157 	if (strncmp(line, "ref: ", 5) == 0) {
158 		line += 5;
159 		return parse_symref(ref, name, line);
160 	}
161 
162 	if (!got_parse_sha1_digest(id.sha1, line))
163 		return got_error(GOT_ERR_BAD_REF_DATA);
164 
165 	return alloc_ref(ref, name, &id, 0, mtime);
166 }
167 
168 static const struct got_error *
169 parse_ref_file(struct got_reference **ref, const char *name,
170     const char *absname, const char *abspath, int lock)
171 {
172 	const struct got_error *err = NULL;
173 	FILE *f;
174 	char *line = NULL;
175 	size_t linesize = 0;
176 	ssize_t linelen;
177 	struct got_lockfile *lf = NULL;
178 	struct stat sb;
179 
180 	if (lock) {
181 		err = got_lockfile_lock(&lf, abspath, -1);
182 		if (err) {
183 			if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
184 				err = got_error_not_ref(name);
185 			return err;
186 		}
187 	}
188 
189 	f = fopen(abspath, "rb");
190 	if (f == NULL) {
191 		if (errno != ENOTDIR && errno != ENOENT)
192 			err = got_error_from_errno2("fopen", abspath);
193 		else
194 			err = got_error_not_ref(name);
195 		if (lock)
196 			got_lockfile_unlock(lf, -1);
197 		return err;
198 	}
199 	if (fstat(fileno(f), &sb) == -1) {
200 		err = got_error_from_errno2("fstat", abspath);
201 		goto done;
202 	}
203 
204 	linelen = getline(&line, &linesize, f);
205 	if (linelen == -1) {
206 		if (feof(f))
207 			err = NULL; /* ignore empty files (could be locks) */
208 		else {
209 			if (errno == EISDIR)
210 				err = got_error(GOT_ERR_NOT_REF);
211 			else if (ferror(f))
212 				err = got_ferror(f, GOT_ERR_IO);
213 			else
214 				err = got_error_from_errno2("getline", abspath);
215 		}
216 		if (lock)
217 			got_lockfile_unlock(lf, -1);
218 		goto done;
219 	}
220 	while (linelen > 0 && line[linelen - 1] == '\n') {
221 		line[linelen - 1] = '\0';
222 		linelen--;
223 	}
224 
225 	err = parse_ref_line(ref, absname, line, sb.st_mtime);
226 	if (lock) {
227 		if (err)
228 			got_lockfile_unlock(lf, -1);
229 		else {
230 			if (*ref)
231 				(*ref)->lf = lf;
232 			else
233 				got_lockfile_unlock(lf, -1);
234 		}
235 	}
236 done:
237 	free(line);
238 	if (fclose(f) == EOF && err == NULL) {
239 		err = got_error_from_errno("fclose");
240 		if (*ref) {
241 			if (lock)
242 				got_ref_unlock(*ref);
243 			got_ref_close(*ref);
244 			*ref = NULL;
245 		}
246 	}
247 	return err;
248 }
249 
250 static int
251 is_well_known_ref(const char *refname)
252 {
253 	return (strcmp(refname, GOT_REF_HEAD) == 0 ||
254 	    strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
255 	    strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
256 	    strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
257 }
258 
259 static char *
260 get_refs_dir_path(struct got_repository *repo, const char *refname)
261 {
262 	if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
263 		return strdup(got_repo_get_path_git_dir(repo));
264 
265 	return got_repo_get_path_refs(repo);
266 }
267 
268 int
269 got_ref_name_is_valid(const char *name)
270 {
271 	const char *s, *seg;
272 	const char forbidden[] = { ' ', '~', '^', ':', '?', '*', '[' , '\\' };
273 	const char *forbidden_seq[] = { "//", "..", "@{" };
274 	const char *lfs = GOT_LOCKFILE_SUFFIX;
275 	const size_t lfs_len = sizeof(GOT_LOCKFILE_SUFFIX) - 1;
276 	size_t i;
277 
278 	if (name[0] == '@' && name[1] == '\0')
279 		return 0;
280 
281 	s = name;
282 	seg = s;
283 	if (seg[0] == '\0' || seg[0] == '.' || seg[0] == '/')
284 		return 0;
285 	while (*s) {
286 		for (i = 0; i < nitems(forbidden); i++) {
287 			if (*s == forbidden[i])
288 				return 0;
289 		}
290 		for (i = 0; i < nitems(forbidden_seq); i++) {
291 			if (s[0] == forbidden_seq[i][0] &&
292 			    s[1] == forbidden_seq[i][1])
293 				return 0;
294 		}
295 		if (iscntrl((unsigned char)s[0]))
296 			return 0;
297 		if (s[0] == '.' && s[1] == '\0')
298 			return 0;
299 		if (*s == '/') {
300 			const char *nextseg = s + 1;
301 			if (nextseg[0] == '\0' || nextseg[0] == '.' ||
302 			    nextseg[0] == '/')
303 				return 0;
304 			if (seg <= s - lfs_len &&
305 			    strncmp(s - lfs_len, lfs, lfs_len) == 0)
306 				return 0;
307 			seg = nextseg;
308 		}
309 		s++;
310 	}
311 
312 	if (seg <= s - lfs_len &&
313 	    strncmp(s - lfs_len, lfs, lfs_len) == 0)
314 		return 0;
315 
316 	return 1;
317 }
318 
319 const struct got_error *
320 got_ref_alloc(struct got_reference **ref, const char *name,
321     struct got_object_id *id)
322 {
323 	if (!got_ref_name_is_valid(name))
324 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
325 
326 	return alloc_ref(ref, name, id, 0, 0);
327 }
328 
329 const struct got_error *
330 got_ref_alloc_symref(struct got_reference **ref, const char *name,
331 	struct got_reference *target_ref)
332 {
333 	if (!got_ref_name_is_valid(name))
334 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
335 
336 	return alloc_symref(ref, name, got_ref_get_name(target_ref), 0);
337 }
338 
339 static const struct got_error *
340 parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
341     const char *line, time_t mtime)
342 {
343 	struct got_object_id id;
344 	const char *name;
345 
346 	*ref = NULL;
347 
348 	if (line[0] == '#' || line[0] == '^')
349 		return NULL;
350 
351 	if (!got_parse_sha1_digest(id.sha1, line))
352 		return got_error(GOT_ERR_BAD_REF_DATA);
353 
354 	if (abs_refname) {
355 		if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
356 			return NULL;
357 		name = abs_refname;
358 	} else
359 		name = line + SHA1_DIGEST_STRING_LENGTH;
360 
361 	return alloc_ref(ref, name, &id, GOT_REF_IS_PACKED, mtime);
362 }
363 
364 static const struct got_error *
365 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
366     int nsubdirs, const char *refname, time_t mtime)
367 {
368 	const struct got_error *err = NULL;
369 	char *abs_refname;
370 	char *line = NULL;
371 	size_t linesize = 0;
372 	ssize_t linelen;
373 	int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
374 
375 	*ref = NULL;
376 
377 	if (ref_is_absolute)
378 		abs_refname = (char *)refname;
379 	do {
380 		linelen = getline(&line, &linesize, f);
381 		if (linelen == -1) {
382 			if (feof(f))
383 				break;
384 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
385 			break;
386 		}
387 		if (linelen > 0 && line[linelen - 1] == '\n')
388 			line[linelen - 1] = '\0';
389 		for (i = 0; i < nsubdirs; i++) {
390 			if (!ref_is_absolute &&
391 			    asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
392 			    refname) == -1)
393 				return got_error_from_errno("asprintf");
394 			err = parse_packed_ref_line(ref, abs_refname, line,
395 			    mtime);
396 			if (!ref_is_absolute)
397 				free(abs_refname);
398 			if (err || *ref != NULL)
399 				break;
400 		}
401 		if (err)
402 			break;
403 	} while (*ref == NULL);
404 	free(line);
405 
406 	return err;
407 }
408 
409 static const struct got_error *
410 open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
411     const char *name, int lock)
412 {
413 	const struct got_error *err = NULL;
414 	char *path = NULL;
415 	char *absname = NULL;
416 	int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
417 	int ref_is_well_known = (subdir[0] == '\0' && is_well_known_ref(name));
418 
419 	*ref = NULL;
420 
421 	if (!got_ref_name_is_valid(name))
422 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
423 
424 	if (ref_is_absolute || ref_is_well_known) {
425 		if (asprintf(&path, "%s/%s", path_refs, name) == -1)
426 			return got_error_from_errno("asprintf");
427 		absname = (char *)name;
428 	} else {
429 		if (asprintf(&path, "%s/%s%s%s", path_refs, subdir,
430 		    subdir[0] ? "/" : "", name) == -1)
431 			return got_error_from_errno("asprintf");
432 
433 		if (asprintf(&absname, "refs/%s%s%s",
434 		    subdir, subdir[0] ? "/" : "", name) == -1) {
435 			err = got_error_from_errno("asprintf");
436 			goto done;
437 		}
438 	}
439 
440 	err = parse_ref_file(ref, name, absname, path, lock);
441 done:
442 	if (!ref_is_absolute && !ref_is_well_known)
443 		free(absname);
444 	free(path);
445 	return err;
446 }
447 
448 const struct got_error *
449 got_ref_open(struct got_reference **ref, struct got_repository *repo,
450     const char *refname, int lock)
451 {
452 	const struct got_error *err = NULL;
453 	char *path_refs = NULL;
454 	const char *subdirs[] = {
455 	    GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
456 	};
457 	size_t i;
458 	int well_known = is_well_known_ref(refname);
459 	struct got_lockfile *lf = NULL;
460 
461 	*ref = NULL;
462 
463 	path_refs = get_refs_dir_path(repo, refname);
464 	if (path_refs == NULL) {
465 		err = got_error_from_errno2("get_refs_dir_path", refname);
466 		goto done;
467 	}
468 
469 	if (well_known) {
470 		err = open_ref(ref, path_refs, "", refname, lock);
471 	} else {
472 		char *packed_refs_path;
473 		FILE *f;
474 
475 		/* Search on-disk refs before packed refs! */
476 		for (i = 0; i < nitems(subdirs); i++) {
477 			err = open_ref(ref, path_refs, subdirs[i], refname,
478 			    lock);
479 			if ((err && err->code != GOT_ERR_NOT_REF) || *ref)
480 				goto done;
481 		}
482 
483 		packed_refs_path = got_repo_get_path_packed_refs(repo);
484 		if (packed_refs_path == NULL) {
485 			err = got_error_from_errno(
486 			    "got_repo_get_path_packed_refs");
487 			goto done;
488 		}
489 
490 		if (lock) {
491 			err = got_lockfile_lock(&lf, packed_refs_path, -1);
492 			if (err)
493 				goto done;
494 		}
495 		f = fopen(packed_refs_path, "rb");
496 		free(packed_refs_path);
497 		if (f != NULL) {
498 			struct stat sb;
499 			if (fstat(fileno(f), &sb) == -1) {
500 				err = got_error_from_errno2("fstat",
501 				    packed_refs_path);
502 				goto done;
503 			}
504 			err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
505 			    refname, sb.st_mtime);
506 			if (!err) {
507 				if (fclose(f) == EOF) {
508 					err = got_error_from_errno("fclose");
509 					got_ref_close(*ref);
510 					*ref = NULL;
511 				} else if (*ref)
512 					(*ref)->lf = lf;
513 			}
514 		}
515 	}
516 done:
517 	if (!err && *ref == NULL)
518 		err = got_error_not_ref(refname);
519 	if (err && lf)
520 		got_lockfile_unlock(lf, -1);
521 	free(path_refs);
522 	return err;
523 }
524 
525 void
526 got_ref_close(struct got_reference *ref)
527 {
528 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
529 		free(ref->ref.symref.name);
530 		free(ref->ref.symref.ref);
531 	} else
532 		free(ref->ref.ref.name);
533 	free(ref);
534 }
535 
536 struct got_reference *
537 got_ref_dup(struct got_reference *ref)
538 {
539 	struct got_reference *ret;
540 
541 	ret = calloc(1, sizeof(*ret));
542 	if (ret == NULL)
543 		return NULL;
544 
545 	ret->flags = ref->flags;
546 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
547 		ret->ref.symref.name = strdup(ref->ref.symref.name);
548 		if (ret->ref.symref.name == NULL) {
549 			free(ret);
550 			return NULL;
551 		}
552 		ret->ref.symref.ref = strdup(ref->ref.symref.ref);
553 		if (ret->ref.symref.ref == NULL) {
554 			free(ret->ref.symref.name);
555 			free(ret);
556 			return NULL;
557 		}
558 	} else {
559 		ret->ref.ref.name = strdup(ref->ref.ref.name);
560 		if (ret->ref.ref.name == NULL) {
561 			free(ret);
562 			return NULL;
563 		}
564 		memcpy(ret->ref.ref.sha1, ref->ref.ref.sha1,
565 		    sizeof(ret->ref.ref.sha1));
566 	}
567 
568 	return ret;
569 }
570 
571 const struct got_error *
572 got_reflist_entry_dup(struct got_reflist_entry **newp,
573     struct got_reflist_entry *re)
574 {
575 	const struct got_error *err = NULL;
576 	struct got_reflist_entry *new;
577 
578 	*newp = NULL;
579 
580 	new = malloc(sizeof(*new));
581 	if (new == NULL)
582 		return got_error_from_errno("malloc");
583 
584 	new->ref = got_ref_dup(re->ref);
585 	if (new->ref == NULL) {
586 		err = got_error_from_errno("got_ref_dup");
587 		free(new);
588 		return err;
589 	}
590 
591 	*newp = new;
592 	return NULL;
593 }
594 
595 const struct got_error *
596 got_ref_resolve_symbolic(struct got_reference **resolved,
597     struct got_repository *repo, struct got_reference *ref)
598 {
599 	struct got_reference *nextref;
600 	const struct got_error *err;
601 
602 	err = got_ref_open(&nextref, repo, ref->ref.symref.ref, 0);
603 	if (err)
604 		return err;
605 
606 	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
607 		err = got_ref_resolve_symbolic(resolved, repo, nextref);
608 	else
609 		*resolved = got_ref_dup(nextref);
610 
611 	got_ref_close(nextref);
612 	return err;
613 }
614 
615 static const struct got_error *
616 ref_resolve(struct got_object_id **id, struct got_repository *repo,
617     struct got_reference *ref, int recursion)
618 {
619 	const struct got_error *err;
620 
621 	if (recursion <= 0)
622 		return got_error_msg(GOT_ERR_RECURSION,
623 		    "reference recursion limit reached");
624 
625 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
626 		struct got_reference *resolved = NULL;
627 		err = got_ref_resolve_symbolic(&resolved, repo, ref);
628 		if (err == NULL)
629 			err = ref_resolve(id, repo, resolved, --recursion);
630 		if (resolved)
631 			got_ref_close(resolved);
632 		return err;
633 	}
634 
635 	*id = calloc(1, sizeof(**id));
636 	if (*id == NULL)
637 		return got_error_from_errno("calloc");
638 	memcpy((*id)->sha1, ref->ref.ref.sha1, sizeof((*id)->sha1));
639 	return NULL;
640 }
641 
642 const struct got_error *
643 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
644     struct got_reference *ref)
645 {
646 	return ref_resolve(id, repo, ref, GOT_REF_RECURSE_MAX);
647 }
648 
649 char *
650 got_ref_to_str(struct got_reference *ref)
651 {
652 	char *str;
653 
654 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
655 		return strdup(ref->ref.symref.ref);
656 
657 	str = malloc(SHA1_DIGEST_STRING_LENGTH);
658 	if (str == NULL)
659 		return NULL;
660 
661 	if (got_sha1_digest_to_str(ref->ref.ref.sha1, str,
662 	    SHA1_DIGEST_STRING_LENGTH) == NULL) {
663 		free(str);
664 		return NULL;
665 	}
666 
667 	return str;
668 }
669 
670 const char *
671 got_ref_get_name(struct got_reference *ref)
672 {
673 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
674 		return ref->ref.symref.name;
675 
676 	return ref->ref.ref.name;
677 }
678 
679 const char *
680 got_ref_get_symref_target(struct got_reference *ref)
681 {
682 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
683 		return ref->ref.symref.ref;
684 
685 	return NULL;
686 }
687 
688 time_t
689 got_ref_get_mtime(struct got_reference *ref)
690 {
691 	return ref->mtime;
692 }
693 
694 const struct got_error *
695 got_ref_cmp_by_name(void *arg, int *cmp, struct got_reference *re1,
696     struct got_reference* re2)
697 {
698 	const char *name1 = got_ref_get_name(re1);
699 	const char *name2 = got_ref_get_name(re2);
700 
701 	*cmp = got_path_cmp(name1, name2, strlen(name1), strlen(name2));
702 	return NULL;
703 }
704 
705 const struct got_error *
706 got_ref_cmp_tags(void *arg, int *cmp, struct got_reference *ref1,
707     struct got_reference *ref2)
708 {
709 	const struct got_error *err = NULL;
710 	struct got_repository *repo = arg;
711 	struct got_object_id *id1, *id2 = NULL;
712 	struct got_tag_object *tag1 = NULL, *tag2 = NULL;
713 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
714 	time_t time1, time2;
715 
716 	*cmp = 0;
717 
718 	err = got_ref_resolve(&id1, repo, ref1);
719 	if (err)
720 		return err;
721 	err = got_object_open_as_tag(&tag1, repo, id1);
722 	if (err) {
723 		if (err->code != GOT_ERR_OBJ_TYPE)
724 			goto done;
725 		/* "lightweight" tag */
726 		err = got_object_open_as_commit(&commit1, repo, id1);
727 		if (err)
728 			goto done;
729 		time1 = got_object_commit_get_committer_time(commit1);
730 	} else
731 		time1 = got_object_tag_get_tagger_time(tag1);
732 
733 	err = got_ref_resolve(&id2, repo, ref2);
734 	if (err)
735 		goto done;
736 	err = got_object_open_as_tag(&tag2, repo, id2);
737 	if (err) {
738 		if (err->code != GOT_ERR_OBJ_TYPE)
739 			goto done;
740 		/* "lightweight" tag */
741 		err = got_object_open_as_commit(&commit2, repo, id2);
742 		if (err)
743 			goto done;
744 		time2 = got_object_commit_get_committer_time(commit2);
745 	} else
746 		time2 = got_object_tag_get_tagger_time(tag2);
747 
748 	/* Put latest tags first. */
749 	if (time1 < time2)
750 		*cmp = 1;
751 	else if (time1 > time2)
752 		*cmp = -1;
753 	else
754 		err = got_ref_cmp_by_name(NULL, cmp, ref2, ref1);
755 done:
756 	free(id1);
757 	free(id2);
758 	if (tag1)
759 		got_object_tag_close(tag1);
760 	if (tag2)
761 		got_object_tag_close(tag2);
762 	if (commit1)
763 		got_object_commit_close(commit1);
764 	if (commit2)
765 		got_object_commit_close(commit2);
766 	return err;
767 }
768 
769 const struct got_error *
770 got_ref_cmp_by_commit_timestamp_descending(void *arg, int *cmp,
771     struct got_reference *ref1, struct got_reference *ref2)
772 {
773 	const struct got_error *err;
774 	struct got_repository *repo = arg;
775 	struct got_object_id *id1, *id2 = NULL;
776 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
777 	time_t time1, time2;
778 
779 	*cmp = 0;
780 
781 	err = got_ref_resolve(&id1, repo, ref1);
782 	if (err)
783 		return err;
784 	err = got_ref_resolve(&id2, repo, ref2);
785 	if (err)
786 		goto done;
787 
788 	err = got_object_open_as_commit(&commit1, repo, id1);
789 	if (err)
790 		goto done;
791 	err = got_object_open_as_commit(&commit2, repo, id2);
792 	if (err)
793 		goto done;
794 	
795 	time1 = got_object_commit_get_committer_time(commit1);
796 	time2 = got_object_commit_get_committer_time(commit2);
797 	if (time1 < time2)
798 		*cmp = 1;
799 	else if (time2 < time1)
800 		*cmp = -1;
801 done:
802 	free(id1);
803 	free(id2);
804 	if (commit1)
805 		got_object_commit_close(commit1);
806 	if (commit2)
807 		got_object_commit_close(commit2);
808 	return err;
809 }
810 
811 const struct got_error *
812 got_reflist_insert(struct got_reflist_entry **newp, struct got_reflist_head *refs,
813     struct got_reference *ref, got_ref_cmp_cb cmp_cb, void *cmp_arg)
814 {
815 	const struct got_error *err;
816 	struct got_reflist_entry *new, *re;
817 	int cmp;
818 
819 	*newp = NULL;
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 static const struct got_error *
860 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
861     const char *subdir, struct got_repository *repo,
862     got_ref_cmp_cb cmp_cb, void *cmp_arg)
863 {
864 	const struct got_error *err = NULL;
865 	DIR *d = NULL;
866 	char *path_subdir;
867 
868 	while (subdir[0] == '/')
869 		subdir++;
870 
871 	if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
872 		return got_error_from_errno("asprintf");
873 
874 	d = opendir(path_subdir);
875 	if (d == NULL)
876 		goto done;
877 
878 	for (;;) {
879 		struct dirent *dent;
880 		struct got_reference *ref;
881 		char *child;
882 		int type;
883 
884 		dent = readdir(d);
885 		if (dent == NULL)
886 			break;
887 
888 		if (strcmp(dent->d_name, ".") == 0 ||
889 		    strcmp(dent->d_name, "..") == 0)
890 			continue;
891 
892 		err = got_path_dirent_type(&type, path_subdir, dent);
893 		if (err)
894 			break;
895 
896 		switch (type) {
897 		case DT_REG:
898 			err = open_ref(&ref, path_refs, subdir, dent->d_name,
899 			    0);
900 			if (err)
901 				goto done;
902 			if (ref) {
903 				struct got_reflist_entry *new;
904 				err = got_reflist_insert(&new, refs, ref,
905 				    cmp_cb, cmp_arg);
906 				if (err || new == NULL /* duplicate */)
907 					got_ref_close(ref);
908 				if (err)
909 					goto done;
910 			}
911 			break;
912 		case DT_DIR:
913 			if (asprintf(&child, "%s%s%s", subdir,
914 			    subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
915 				err = got_error_from_errno("asprintf");
916 				break;
917 			}
918 			err = gather_on_disk_refs(refs, path_refs, child, repo,
919 			    cmp_cb, cmp_arg);
920 			free(child);
921 			break;
922 		default:
923 			break;
924 		}
925 	}
926 done:
927 	if (d)
928 		closedir(d);
929 	free(path_subdir);
930 	return err;
931 }
932 
933 const struct got_error *
934 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo,
935     const char *ref_namespace, got_ref_cmp_cb cmp_cb, void *cmp_arg)
936 {
937 	const struct got_error *err;
938 	char *packed_refs_path, *path_refs = NULL;
939 	char *abs_namespace = NULL;
940 	char *buf = NULL, *ondisk_ref_namespace = NULL;
941 	char *line = NULL;
942 	FILE *f = NULL;
943 	struct got_reference *ref;
944 	struct got_reflist_entry *new;
945 
946 	if (ref_namespace == NULL || ref_namespace[0] == '\0') {
947 		path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
948 		if (path_refs == NULL) {
949 			err = got_error_from_errno("get_refs_dir_path");
950 			goto done;
951 		}
952 		err = open_ref(&ref, path_refs, "", GOT_REF_HEAD, 0);
953 		if (err)
954 			goto done;
955 		err = got_reflist_insert(&new, refs, ref, cmp_cb, cmp_arg);
956 		if (err || new == NULL /* duplicate */)
957 			got_ref_close(ref);
958 		if (err && err->code != GOT_ERR_NOT_REF)
959 			goto done;
960 	} else {
961 		/* Try listing a single reference. */
962 		const char *refname = ref_namespace;
963 		path_refs = get_refs_dir_path(repo, refname);
964 		if (path_refs == NULL) {
965 			err = got_error_from_errno("get_refs_dir_path");
966 			goto done;
967 		}
968 		err = open_ref(&ref, path_refs, "", refname, 0);
969 		if (err) {
970 			if (err->code != GOT_ERR_NOT_REF)
971 				goto done;
972 			/* Try to look up references in a given namespace. */
973 		} else {
974 			err = got_reflist_insert(&new, refs, ref,
975 			    cmp_cb, cmp_arg);
976 			if (err || new == NULL /* duplicate */)
977 				got_ref_close(ref);
978 			return err;
979 		}
980 	}
981 
982 	if (ref_namespace) {
983 		size_t len;
984 		/* Canonicalize the path to eliminate double-slashes if any. */
985 		if (asprintf(&abs_namespace, "/%s", ref_namespace) == -1) {
986 			err = got_error_from_errno("asprintf");
987 			goto done;
988 		}
989 		len = strlen(abs_namespace) + 1;
990 		buf = malloc(len);
991 		if (buf == NULL) {
992 			err = got_error_from_errno("malloc");
993 			goto done;
994 		}
995 		err = got_canonpath(abs_namespace, buf, len);
996 		if (err)
997 			goto done;
998 		ondisk_ref_namespace = buf;
999 		while (ondisk_ref_namespace[0] == '/')
1000 			ondisk_ref_namespace++;
1001 		if (strncmp(ondisk_ref_namespace, "refs/", 5) == 0)
1002 			ondisk_ref_namespace += 5;
1003 		else if (strcmp(ondisk_ref_namespace, "refs") == 0)
1004 			ondisk_ref_namespace = "";
1005 	}
1006 
1007 	/* Gather on-disk refs before parsing packed-refs. */
1008 	free(path_refs);
1009 	path_refs = get_refs_dir_path(repo, "");
1010 	if (path_refs == NULL) {
1011 		err = got_error_from_errno("get_refs_dir_path");
1012 		goto done;
1013 	}
1014 	err = gather_on_disk_refs(refs, path_refs,
1015 	    ondisk_ref_namespace ? ondisk_ref_namespace : "", repo,
1016 	    cmp_cb, cmp_arg);
1017 	if (err)
1018 		goto done;
1019 
1020 	/*
1021 	 * The packed-refs file may contain redundant entries, in which
1022 	 * case on-disk refs take precedence.
1023 	 */
1024 	packed_refs_path = got_repo_get_path_packed_refs(repo);
1025 	if (packed_refs_path == NULL) {
1026 		err = got_error_from_errno("got_repo_get_path_packed_refs");
1027 		goto done;
1028 	}
1029 
1030 	f = fopen(packed_refs_path, "r");
1031 	free(packed_refs_path);
1032 	if (f) {
1033 		size_t linesize = 0;
1034 		ssize_t linelen;
1035 		struct stat sb;
1036 
1037 		if (fstat(fileno(f), &sb) == -1) {
1038 			err = got_error_from_errno2("fstat", packed_refs_path);
1039 			goto done;
1040 		}
1041 		for (;;) {
1042 			linelen = getline(&line, &linesize, f);
1043 			if (linelen == -1) {
1044 				if (feof(f))
1045 					break;
1046 				err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1047 				goto done;
1048 			}
1049 			if (linelen > 0 && line[linelen - 1] == '\n')
1050 				line[linelen - 1] = '\0';
1051 			err = parse_packed_ref_line(&ref, NULL, line,
1052 			    sb.st_mtime);
1053 			if (err)
1054 				goto done;
1055 			if (ref) {
1056 				if (ref_namespace) {
1057 					const char *name;
1058 					name = got_ref_get_name(ref);
1059 					if (!got_path_is_child(name,
1060 					    ref_namespace,
1061 					    strlen(ref_namespace))) {
1062 						got_ref_close(ref);
1063 						continue;
1064 					}
1065 				}
1066 				err = got_reflist_insert(&new, refs, ref,
1067 				    cmp_cb, cmp_arg);
1068 				if (err || new == NULL /* duplicate */)
1069 					got_ref_close(ref);
1070 				if (err)
1071 					goto done;
1072 			}
1073 		}
1074 	}
1075 done:
1076 	free(abs_namespace);
1077 	free(buf);
1078 	free(line);
1079 	free(path_refs);
1080 	if (f && fclose(f) == EOF && err == NULL)
1081 		err = got_error_from_errno("fclose");
1082 	return err;
1083 }
1084 
1085 void
1086 got_ref_list_free(struct got_reflist_head *refs)
1087 {
1088 	struct got_reflist_entry *re;
1089 
1090 	while ((re = TAILQ_FIRST(refs))) {
1091 		TAILQ_REMOVE(refs, re, entry);
1092 		got_ref_close(re->ref);
1093 		free(re);
1094 	}
1095 
1096 }
1097 
1098 int
1099 got_ref_is_symbolic(struct got_reference *ref)
1100 {
1101 	return (ref->flags & GOT_REF_IS_SYMBOLIC);
1102 }
1103 
1104 const struct got_error *
1105 got_ref_change_ref(struct got_reference *ref, struct got_object_id *id)
1106 {
1107 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
1108 		return got_error(GOT_ERR_BAD_REF_TYPE);
1109 
1110 	memcpy(ref->ref.ref.sha1, id->sha1, sizeof(ref->ref.ref.sha1));
1111 	return NULL;
1112 }
1113 
1114 const struct got_error *
1115 got_ref_change_symref(struct got_reference *ref, const char *refname)
1116 {
1117 	char *new_name;
1118 
1119 	if ((ref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1120 		return got_error(GOT_ERR_BAD_REF_TYPE);
1121 
1122 	new_name = strdup(refname);
1123 	if (new_name == NULL)
1124 		return got_error_from_errno("strdup");
1125 
1126 	free(ref->ref.symref.ref);
1127 	ref->ref.symref.ref = new_name;
1128 	return NULL;
1129 }
1130 
1131 const struct got_error *
1132 got_ref_change_symref_to_ref(struct got_reference *symref,
1133     struct got_object_id *id)
1134 {
1135 	if ((symref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1136 		return got_error(GOT_ERR_BAD_REF_TYPE);
1137 
1138 	symref->ref.ref.name = symref->ref.symref.name;
1139 	memcpy(symref->ref.ref.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1140 	symref->flags &= ~GOT_REF_IS_SYMBOLIC;
1141 	return NULL;
1142 }
1143 
1144 const struct got_error *
1145 got_ref_write(struct got_reference *ref, struct got_repository *repo)
1146 {
1147 	const struct got_error *err = NULL, *unlock_err = NULL;
1148 	const char *name = got_ref_get_name(ref);
1149 	char *path_refs = NULL, *path = NULL, *tmppath = NULL;
1150 	struct got_lockfile *lf = NULL;
1151 	FILE *f = NULL;
1152 	size_t n;
1153 	struct stat sb;
1154 
1155 	path_refs = get_refs_dir_path(repo, name);
1156 	if (path_refs == NULL) {
1157 		err = got_error_from_errno2("get_refs_dir_path", name);
1158 		goto done;
1159 	}
1160 
1161 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1162 		err = got_error_from_errno("asprintf");
1163 		goto done;
1164 	}
1165 
1166 	err = got_opentemp_named(&tmppath, &f, path);
1167 	if (err) {
1168 		char *parent;
1169 		if (!(err->code == GOT_ERR_ERRNO && errno == ENOENT))
1170 			goto done;
1171 		err = got_path_dirname(&parent, path);
1172 		if (err)
1173 			goto done;
1174 		err = got_path_mkdir(parent);
1175 		free(parent);
1176 		if (err)
1177 			goto done;
1178 		err = got_opentemp_named(&tmppath, &f, path);
1179 		if (err)
1180 			goto done;
1181 	}
1182 
1183 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
1184 		n = fprintf(f, "ref: %s\n", ref->ref.symref.ref);
1185 		if (n != strlen(ref->ref.symref.ref) + 6) {
1186 			err = got_ferror(f, GOT_ERR_IO);
1187 			goto done;
1188 		}
1189 	} else {
1190 		char hex[SHA1_DIGEST_STRING_LENGTH];
1191 		if (got_sha1_digest_to_str(ref->ref.ref.sha1, hex,
1192 		    sizeof(hex)) == NULL) {
1193 			err = got_error(GOT_ERR_BAD_REF_DATA);
1194 			goto done;
1195 		}
1196 		n = fprintf(f, "%s\n", hex);
1197 		if (n != sizeof(hex)) {
1198 			err = got_ferror(f, GOT_ERR_IO);
1199 			goto done;
1200 		}
1201 	}
1202 
1203 	if (ref->lf == NULL) {
1204 		err = got_lockfile_lock(&lf, path, -1);
1205 		if (err)
1206 			goto done;
1207 	}
1208 
1209 	/* XXX: check if old content matches our expectations? */
1210 
1211 	if (stat(path, &sb) != 0) {
1212 		if (errno != ENOENT) {
1213 			err = got_error_from_errno2("stat", path);
1214 			goto done;
1215 		}
1216 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
1217 	}
1218 
1219 	if (fchmod(fileno(f), sb.st_mode) != 0) {
1220 		err = got_error_from_errno2("fchmod", tmppath);
1221 		goto done;
1222 	}
1223 
1224 	if (rename(tmppath, path) != 0) {
1225 		err = got_error_from_errno3("rename", tmppath, path);
1226 		goto done;
1227 	}
1228 	free(tmppath);
1229 	tmppath = NULL;
1230 
1231 	if (stat(path, &sb) == -1) {
1232 		err = got_error_from_errno2("stat", path);
1233 		goto done;
1234 	}
1235 	ref->mtime = sb.st_mtime;
1236 done:
1237 	if (ref->lf == NULL && lf)
1238 		unlock_err = got_lockfile_unlock(lf, -1);
1239 	if (f) {
1240 		if (fclose(f) == EOF && err == NULL)
1241 			err = got_error_from_errno("fclose");
1242 	}
1243 	free(path_refs);
1244 	free(path);
1245 	if (tmppath) {
1246 		if (unlink(tmppath) != 0 && err == NULL)
1247 			err = got_error_from_errno2("unlink", tmppath);
1248 		free(tmppath);
1249 	}
1250 	return err ? err : unlock_err;
1251 }
1252 
1253 static const struct got_error *
1254 delete_packed_ref(struct got_reference *delref, struct got_repository *repo)
1255 {
1256 	const struct got_error *err = NULL, *unlock_err = NULL;
1257 	struct got_lockfile *lf = NULL;
1258 	FILE *f = NULL, *tmpf = NULL;
1259 	char *line = NULL, *packed_refs_path, *tmppath = NULL;
1260 	size_t linesize = 0;
1261 	struct got_reflist_head refs;
1262 	int found_delref = 0;
1263 
1264 	/* The packed-refs file does not cotain symbolic references. */
1265 	if (delref->flags & GOT_REF_IS_SYMBOLIC)
1266 		return got_error(GOT_ERR_BAD_REF_DATA);
1267 
1268 	TAILQ_INIT(&refs);
1269 
1270 	packed_refs_path = got_repo_get_path_packed_refs(repo);
1271 	if (packed_refs_path == NULL)
1272 		return got_error_from_errno("got_repo_get_path_packed_refs");
1273 
1274 	err = got_opentemp_named(&tmppath, &tmpf, packed_refs_path);
1275 	if (err)
1276 		goto done;
1277 
1278 	if (delref->lf == NULL) {
1279 		err = got_lockfile_lock(&lf, packed_refs_path, -1);
1280 		if (err)
1281 			goto done;
1282 	}
1283 
1284 	f = fopen(packed_refs_path, "r");
1285 	if (f == NULL) {
1286 		err = got_error_from_errno2("fopen", packed_refs_path);
1287 		goto done;
1288 	}
1289 	for (;;) {
1290 		ssize_t linelen;
1291 		struct got_reference *ref;
1292 		struct got_reflist_entry *new;
1293 
1294 		linelen = getline(&line, &linesize, f);
1295 		if (linelen == -1) {
1296 			if (feof(f))
1297 				break;
1298 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1299 			goto done;
1300 		}
1301 		if (linelen > 0 && line[linelen - 1] == '\n')
1302 			line[linelen - 1] = '\0';
1303 		err = parse_packed_ref_line(&ref, NULL, line, 0);
1304 		if (err)
1305 			goto done;
1306 		if (ref == NULL)
1307 			continue;
1308 
1309 		if (strcmp(ref->ref.ref.name, delref->ref.ref.name) == 0 &&
1310 		    memcmp(ref->ref.ref.sha1, delref->ref.ref.sha1,
1311 		    sizeof(delref->ref.ref.sha1)) == 0) {
1312 			found_delref = 1;
1313 			got_ref_close(ref);
1314 			continue;
1315 		}
1316 
1317 		err = got_reflist_insert(&new, &refs, ref,
1318 		    got_ref_cmp_by_name, NULL);
1319 		if (err || new == NULL /* duplicate */)
1320 			got_ref_close(ref);
1321 		if (err)
1322 			goto done;
1323 	}
1324 
1325 	if (found_delref) {
1326 		struct got_reflist_entry *re;
1327 		size_t n;
1328 		struct stat sb;
1329 
1330 		n = fprintf(tmpf, "%s\n", GOT_PACKED_REFS_HEADER);
1331 		if (n != sizeof(GOT_PACKED_REFS_HEADER)) {
1332 			err = got_ferror(f, GOT_ERR_IO);
1333 			goto done;
1334 		}
1335 
1336 		TAILQ_FOREACH(re, &refs, entry) {
1337 			uint8_t hex[SHA1_DIGEST_STRING_LENGTH];
1338 
1339 			if (got_sha1_digest_to_str(re->ref->ref.ref.sha1, hex,
1340 			    sizeof(hex)) == NULL) {
1341 				err = got_error(GOT_ERR_BAD_REF_DATA);
1342 				goto done;
1343 			}
1344 			n = fprintf(tmpf, "%s ", hex);
1345 			if (n != sizeof(hex)) {
1346 				err = got_ferror(f, GOT_ERR_IO);
1347 				goto done;
1348 			}
1349 			n = fprintf(tmpf, "%s\n", re->ref->ref.ref.name);
1350 			if (n != strlen(re->ref->ref.ref.name) + 1) {
1351 				err = got_ferror(f, GOT_ERR_IO);
1352 				goto done;
1353 			}
1354 		}
1355 
1356 		if (fflush(tmpf) != 0) {
1357 			err = got_error_from_errno("fflush");
1358 			goto done;
1359 		}
1360 
1361 		if (fstat(fileno(f), &sb) != 0) {
1362 			if (errno != ENOENT) {
1363 				err = got_error_from_errno2("fstat",
1364 				    packed_refs_path);
1365 				goto done;
1366 			}
1367 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1368 		}
1369 
1370 		if (fchmod(fileno(tmpf), sb.st_mode) != 0) {
1371 			err = got_error_from_errno2("fchmod", tmppath);
1372 			goto done;
1373 		}
1374 
1375 		if (rename(tmppath, packed_refs_path) != 0) {
1376 			err = got_error_from_errno3("rename", tmppath,
1377 			    packed_refs_path);
1378 			goto done;
1379 		}
1380 	}
1381 done:
1382 	if (delref->lf == NULL && lf)
1383 		unlock_err = got_lockfile_unlock(lf, -1);
1384 	if (f) {
1385 		if (fclose(f) == EOF && err == NULL)
1386 			err = got_error_from_errno("fclose");
1387 	}
1388 	if (tmpf) {
1389 		unlink(tmppath);
1390 		if (fclose(tmpf) == EOF && err == NULL)
1391 			err = got_error_from_errno("fclose");
1392 	}
1393 	free(tmppath);
1394 	free(packed_refs_path);
1395 	free(line);
1396 	got_ref_list_free(&refs);
1397 	return err ? err : unlock_err;
1398 }
1399 
1400 static const struct got_error *
1401 delete_loose_ref(struct got_reference *ref, struct got_repository *repo)
1402 {
1403 	const struct got_error *err = NULL, *unlock_err = NULL;
1404 	const char *name = got_ref_get_name(ref);
1405 	char *path_refs = NULL, *path = NULL;
1406 	struct got_lockfile *lf = NULL;
1407 
1408 	path_refs = get_refs_dir_path(repo, name);
1409 	if (path_refs == NULL) {
1410 		err = got_error_from_errno2("get_refs_dir_path", name);
1411 		goto done;
1412 	}
1413 
1414 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1415 		err = got_error_from_errno("asprintf");
1416 		goto done;
1417 	}
1418 
1419 	if (ref->lf == NULL) {
1420 		err = got_lockfile_lock(&lf, path, -1);
1421 		if (err)
1422 			goto done;
1423 	}
1424 
1425 	/* XXX: check if old content matches our expectations? */
1426 
1427 	if (unlink(path) != 0)
1428 		err = got_error_from_errno2("unlink", path);
1429 done:
1430 	if (ref->lf == NULL && lf)
1431 		unlock_err = got_lockfile_unlock(lf, -1);
1432 
1433 	free(path_refs);
1434 	free(path);
1435 	return err ? err : unlock_err;
1436 }
1437 
1438 const struct got_error *
1439 got_ref_delete(struct got_reference *ref, struct got_repository *repo)
1440 {
1441 	const struct got_error *err = NULL;
1442 	struct got_reference *ref2;
1443 
1444 	if (ref->flags & GOT_REF_IS_PACKED) {
1445 		err = delete_packed_ref(ref, repo);
1446 		if (err)
1447 			return err;
1448 
1449 		err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1450 		if (err) {
1451 			if (err->code == GOT_ERR_NOT_REF)
1452 				return NULL;
1453 			return err;
1454 		}
1455 
1456 		err = delete_loose_ref(ref2, repo);
1457 		got_ref_close(ref2);
1458 		return err;
1459 	} else {
1460 		err = delete_loose_ref(ref, repo);
1461 		if (err)
1462 			return err;
1463 
1464 		err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1465 		if (err) {
1466 			if (err->code == GOT_ERR_NOT_REF)
1467 				return NULL;
1468 			return err;
1469 		}
1470 
1471 		err = delete_packed_ref(ref2, repo);
1472 		got_ref_close(ref2);
1473 		return err;
1474 	}
1475 }
1476 
1477 const struct got_error *
1478 got_ref_unlock(struct got_reference *ref)
1479 {
1480 	const struct got_error *err;
1481 	err = got_lockfile_unlock(ref->lf, -1);
1482 	ref->lf = NULL;
1483 	return err;
1484 }
1485 
1486 struct got_reflist_object_id_map {
1487 	struct got_object_idset *idset;
1488 };
1489 
1490 struct got_reflist_object_id_map_entry {
1491 	struct got_reflist_head refs;
1492 };
1493 
1494 static const struct got_error *
1495 add_object_id_map_entry(struct got_object_idset *idset,
1496     struct got_object_id *id, struct got_reflist_entry *re)
1497 {
1498 	const struct got_error *err = NULL;
1499 	struct got_reflist_object_id_map_entry *ent;
1500 	struct got_reflist_entry *new;
1501 
1502 	ent = got_object_idset_get(idset, id);
1503 	if (ent == NULL) {
1504 		ent = malloc(sizeof(*ent));
1505 		if (ent == NULL)
1506 			return got_error_from_errno("malloc");
1507 
1508 		TAILQ_INIT(&ent->refs);
1509 		err = got_object_idset_add(idset, id, ent);
1510 		if (err)
1511 			return err;
1512 	}
1513 
1514 	err = got_reflist_entry_dup(&new, re);
1515 	if (err)
1516 		return err;
1517 
1518 	TAILQ_INSERT_TAIL(&ent->refs, new, entry);
1519 	return NULL;
1520 }
1521 
1522 const struct got_error *
1523 got_reflist_object_id_map_create(struct got_reflist_object_id_map **map,
1524     struct got_reflist_head *refs, struct got_repository *repo)
1525 {
1526 	const struct got_error *err = NULL;
1527 	struct got_object_idset *idset;
1528 	struct got_object_id *id = NULL;
1529 	struct got_reflist_entry *re;
1530 
1531 	idset = got_object_idset_alloc();
1532 	if (idset == NULL)
1533 		return got_error_from_errno("got_object_idset_alloc");
1534 
1535 	*map = malloc(sizeof(**map));
1536 	if (*map == NULL) {
1537 		got_object_idset_free(idset);
1538 		return got_error_from_errno("malloc");
1539 	}
1540 	(*map)->idset = idset;
1541 
1542 	TAILQ_FOREACH(re, refs, entry) {
1543 		struct got_tag_object *tag = NULL;
1544 
1545 		err = got_ref_resolve(&id, repo, re->ref);
1546 		if (err)
1547 			goto done;
1548 
1549 		err = add_object_id_map_entry(idset, id, re);
1550 		if (err)
1551 			goto done;
1552 
1553 		if (strstr(got_ref_get_name(re->ref), "/tags/") == NULL) {
1554 			free(id);
1555 			id = NULL;
1556 			continue;
1557 		}
1558 
1559 		err = got_object_open_as_tag(&tag, repo, id);
1560 		if (err) {
1561 			if (err->code != GOT_ERR_OBJ_TYPE)
1562 				goto done;
1563 			/* Ref points at something other than a tag. */
1564 			err = NULL;
1565 			tag = NULL;
1566 			free(id);
1567 			id = NULL;
1568 			continue;
1569 		}
1570 
1571 		err = add_object_id_map_entry(idset,
1572 		    got_object_tag_get_object_id(tag), re);
1573 		got_object_tag_close(tag);
1574 		if (err)
1575 			goto done;
1576 
1577 		free(id);
1578 		id = NULL;
1579 	}
1580 done:
1581 	free(id);
1582 	if (err) {
1583 		got_reflist_object_id_map_free(*map);
1584 		*map = NULL;
1585 	}
1586 	return err;
1587 }
1588 
1589 struct got_reflist_head *
1590 got_reflist_object_id_map_lookup(struct got_reflist_object_id_map *map,
1591     struct got_object_id *id)
1592 {
1593 	struct got_reflist_object_id_map_entry *ent;
1594 	ent = got_object_idset_get(map->idset, id);
1595 	if (ent)
1596 		return &ent->refs;
1597 	return NULL;
1598 }
1599 
1600 static const struct got_error *
1601 free_id_map_entry(struct got_object_id *id, void *data, void *arg)
1602 {
1603 	struct got_reflist_object_id_map_entry *ent = data;
1604 
1605 	got_ref_list_free(&ent->refs);
1606 	free(ent);
1607 	return NULL;
1608 }
1609 
1610 void
1611 got_reflist_object_id_map_free(struct got_reflist_object_id_map *map)
1612 {
1613 	got_object_idset_for_each(map->idset, free_id_map_entry, NULL);
1614 	got_object_idset_free(map->idset);
1615 	free(map);
1616 }