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/stat.h>
19 
20 #include <errno.h>
21 #include <ctype.h>
22 #include <dirent.h>
23 #include <limits.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <unistd.h>
28 #include <zlib.h>
29 #include <time.h>
30 #include <libgen.h>
31 
32 #include "got_compat.h"
33 
34 #include "got_error.h"
35 #include "got_object.h"
36 #include "got_repository.h"
37 #include "got_reference.h"
38 #include "got_opentemp.h"
39 #include "got_path.h"
40 
41 #include "got_lib_sha1.h"
42 #include "got_lib_delta.h"
43 #include "got_lib_inflate.h"
44 #include "got_lib_object.h"
45 #include "got_lib_object_idset.h"
46 #include "got_lib_lockfile.h"
47 
48 #ifndef nitems
49 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
50 #endif
51 
52 #define GOT_REF_HEADS	"heads"
53 #define GOT_REF_TAGS	"tags"
54 #define GOT_REF_REMOTES	"remotes"
55 
56 /*
57  * We do not resolve tags yet, and don't yet care about sorting refs either,
58  * so packed-refs files we write contain a minimal header which disables all
59  * packed-refs "traits" supported by Git.
60  */
61 #define GOT_PACKED_REFS_HEADER	"# pack-refs with:"
62 
63 /* A symbolic reference. */
64 struct got_symref {
65 	char *name;
66 	char *ref;
67 };
68 
69 #define GOT_REF_RECURSE_MAX	20
70 
71 /* A non-symbolic reference (there is no better designation). */
72 struct got_ref {
73 	char *name;
74 	u_int8_t sha1[SHA1_DIGEST_LENGTH];
75 };
76 
77 /* A reference which points to an arbitrary object. */
78 struct got_reference {
79 	unsigned int flags;
80 #define GOT_REF_IS_SYMBOLIC	0x01
81 #define GOT_REF_IS_PACKED	0x02
82 
83 	union {
84 		struct got_ref ref;
85 		struct got_symref symref;
86 	} ref;
87 
88 	struct got_lockfile *lf;
89 	time_t mtime;
90 
91 	/* Cached timestamp for got_ref_cmp_by_commit_timestamp_descending() */
92 	time_t committer_time;
93 };
94 
95 static const struct got_error *
96 alloc_ref(struct got_reference **ref, const char *name,
97     struct got_object_id *id, int flags, time_t mtime)
98 {
99 	const struct got_error *err = NULL;
100 
101 	*ref = calloc(1, sizeof(**ref));
102 	if (*ref == NULL)
103 		return got_error_from_errno("calloc");
104 
105 	memcpy((*ref)->ref.ref.sha1, id->sha1, sizeof((*ref)->ref.ref.sha1));
106 	(*ref)->flags = flags;
107 	(*ref)->ref.ref.name = strdup(name);
108 	(*ref)->mtime = mtime;
109 	if ((*ref)->ref.ref.name == NULL) {
110 		err = got_error_from_errno("strdup");
111 		got_ref_close(*ref);
112 		*ref = NULL;
113 	}
114 	return err;
115 }
116 
117 static const struct got_error *
118 alloc_symref(struct got_reference **ref, const char *name,
119     const char *target_ref, int flags)
120 {
121 	const struct got_error *err = NULL;
122 
123 	*ref = calloc(1, sizeof(**ref));
124 	if (*ref == NULL)
125 		return got_error_from_errno("calloc");
126 
127 	(*ref)->flags = GOT_REF_IS_SYMBOLIC | flags;
128 	(*ref)->ref.symref.name = strdup(name);
129 	if ((*ref)->ref.symref.name == NULL) {
130 		err = got_error_from_errno("strdup");
131 		got_ref_close(*ref);
132 		*ref = NULL;
133 		return err;
134 	}
135 	(*ref)->ref.symref.ref = strdup(target_ref);
136 	if ((*ref)->ref.symref.ref == NULL) {
137 		err = got_error_from_errno("strdup");
138 		got_ref_close(*ref);
139 		*ref = NULL;
140 	}
141 	return err;
142 }
143 
144 static const struct got_error *
145 parse_symref(struct got_reference **ref, const char *name, const char *line)
146 {
147 	if (line[0] == '\0')
148 		return got_error(GOT_ERR_BAD_REF_DATA);
149 
150 	return alloc_symref(ref, name, line, 0);
151 }
152 
153 static const struct got_error *
154 parse_ref_line(struct got_reference **ref, const char *name, const char *line,
155     time_t mtime)
156 {
157 	struct got_object_id id;
158 
159 	if (strncmp(line, "ref: ", 5) == 0) {
160 		line += 5;
161 		return parse_symref(ref, name, line);
162 	}
163 
164 	if (!got_parse_sha1_digest(id.sha1, line))
165 		return got_error(GOT_ERR_BAD_REF_DATA);
166 
167 	return alloc_ref(ref, name, &id, 0, mtime);
168 }
169 
170 static const struct got_error *
171 parse_ref_file(struct got_reference **ref, const char *name,
172     const char *absname, const char *abspath, int lock)
173 {
174 	const struct got_error *err = NULL;
175 	FILE *f;
176 	char *line = NULL;
177 	size_t linesize = 0;
178 	ssize_t linelen;
179 	struct got_lockfile *lf = NULL;
180 	struct stat sb;
181 
182 	if (lock) {
183 		err = got_lockfile_lock(&lf, abspath, -1);
184 		if (err) {
185 			if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
186 				err = got_error_not_ref(name);
187 			return err;
188 		}
189 	}
190 
191 	f = fopen(abspath, "rb");
192 	if (f == NULL) {
193 		if (errno != ENOTDIR && errno != ENOENT)
194 			err = got_error_from_errno2("fopen", abspath);
195 		else
196 			err = got_error_not_ref(name);
197 		if (lock)
198 			got_lockfile_unlock(lf, -1);
199 		return err;
200 	}
201 	if (fstat(fileno(f), &sb) == -1) {
202 		err = got_error_from_errno2("fstat", abspath);
203 		goto done;
204 	}
205 
206 	linelen = getline(&line, &linesize, f);
207 	if (linelen == -1) {
208 		if (feof(f))
209 			err = NULL; /* ignore empty files (could be locks) */
210 		else {
211 			if (errno == EISDIR)
212 				err = got_error(GOT_ERR_NOT_REF);
213 			else if (ferror(f))
214 				err = got_ferror(f, GOT_ERR_IO);
215 			else
216 				err = got_error_from_errno2("getline", abspath);
217 		}
218 		if (lock)
219 			got_lockfile_unlock(lf, -1);
220 		goto done;
221 	}
222 	while (linelen > 0 && line[linelen - 1] == '\n') {
223 		line[linelen - 1] = '\0';
224 		linelen--;
225 	}
226 
227 	err = parse_ref_line(ref, absname, line, sb.st_mtime);
228 	if (lock) {
229 		if (err)
230 			got_lockfile_unlock(lf, -1);
231 		else {
232 			if (*ref)
233 				(*ref)->lf = lf;
234 			else
235 				got_lockfile_unlock(lf, -1);
236 		}
237 	}
238 done:
239 	free(line);
240 	if (fclose(f) == EOF && err == NULL) {
241 		err = got_error_from_errno("fclose");
242 		if (*ref) {
243 			if (lock)
244 				got_ref_unlock(*ref);
245 			got_ref_close(*ref);
246 			*ref = NULL;
247 		}
248 	}
249 	return err;
250 }
251 
252 static int
253 is_well_known_ref(const char *refname)
254 {
255 	return (strcmp(refname, GOT_REF_HEAD) == 0 ||
256 	    strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
257 	    strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
258 	    strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
259 }
260 
261 static char *
262 get_refs_dir_path(struct got_repository *repo, const char *refname)
263 {
264 	if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
265 		return strdup(got_repo_get_path_git_dir(repo));
266 
267 	return got_repo_get_path_refs(repo);
268 }
269 
270 int
271 got_ref_name_is_valid(const char *name)
272 {
273 	const char *s, *seg;
274 	const char forbidden[] = { ' ', '~', '^', ':', '?', '*', '[' , '\\' };
275 	const char *forbidden_seq[] = { "//", "..", "@{" };
276 	const char *lfs = GOT_LOCKFILE_SUFFIX;
277 	const size_t lfs_len = sizeof(GOT_LOCKFILE_SUFFIX) - 1;
278 	size_t i;
279 
280 	if (name[0] == '@' && name[1] == '\0')
281 		return 0;
282 
283 	s = name;
284 	seg = s;
285 	if (seg[0] == '\0' || seg[0] == '.' || seg[0] == '/')
286 		return 0;
287 	while (*s) {
288 		for (i = 0; i < nitems(forbidden); i++) {
289 			if (*s == forbidden[i])
290 				return 0;
291 		}
292 		for (i = 0; i < nitems(forbidden_seq); i++) {
293 			if (s[0] == forbidden_seq[i][0] &&
294 			    s[1] == forbidden_seq[i][1])
295 				return 0;
296 		}
297 		if (iscntrl((unsigned char)s[0]))
298 			return 0;
299 		if (s[0] == '.' && s[1] == '\0')
300 			return 0;
301 		if (*s == '/') {
302 			const char *nextseg = s + 1;
303 			if (nextseg[0] == '\0' || nextseg[0] == '.' ||
304 			    nextseg[0] == '/')
305 				return 0;
306 			if (seg <= s - lfs_len &&
307 			    strncmp(s - lfs_len, lfs, lfs_len) == 0)
308 				return 0;
309 			seg = nextseg;
310 		}
311 		s++;
312 	}
313 
314 	if (seg <= s - lfs_len &&
315 	    strncmp(s - lfs_len, lfs, lfs_len) == 0)
316 		return 0;
317 
318 	return 1;
319 }
320 
321 const struct got_error *
322 got_ref_alloc(struct got_reference **ref, const char *name,
323     struct got_object_id *id)
324 {
325 	if (!got_ref_name_is_valid(name))
326 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
327 
328 	return alloc_ref(ref, name, id, 0, 0);
329 }
330 
331 const struct got_error *
332 got_ref_alloc_symref(struct got_reference **ref, const char *name,
333 	struct got_reference *target_ref)
334 {
335 	if (!got_ref_name_is_valid(name))
336 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
337 
338 	return alloc_symref(ref, name, got_ref_get_name(target_ref), 0);
339 }
340 
341 static const struct got_error *
342 parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
343     const char *line, time_t mtime)
344 {
345 	struct got_object_id id;
346 	const char *name;
347 
348 	*ref = NULL;
349 
350 	if (line[0] == '#' || line[0] == '^')
351 		return NULL;
352 
353 	if (!got_parse_sha1_digest(id.sha1, line))
354 		return got_error(GOT_ERR_BAD_REF_DATA);
355 
356 	if (abs_refname) {
357 		if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
358 			return NULL;
359 		name = abs_refname;
360 	} else
361 		name = line + SHA1_DIGEST_STRING_LENGTH;
362 
363 	return alloc_ref(ref, name, &id, GOT_REF_IS_PACKED, mtime);
364 }
365 
366 static const struct got_error *
367 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
368     int nsubdirs, const char *refname, time_t mtime)
369 {
370 	const struct got_error *err = NULL;
371 	char *abs_refname;
372 	char *line = NULL;
373 	size_t linesize = 0;
374 	ssize_t linelen;
375 	int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
376 
377 	*ref = NULL;
378 
379 	if (ref_is_absolute)
380 		abs_refname = (char *)refname;
381 	do {
382 		linelen = getline(&line, &linesize, f);
383 		if (linelen == -1) {
384 			if (feof(f))
385 				break;
386 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
387 			break;
388 		}
389 		if (linelen > 0 && line[linelen - 1] == '\n')
390 			line[linelen - 1] = '\0';
391 		for (i = 0; i < nsubdirs; i++) {
392 			if (!ref_is_absolute &&
393 			    asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
394 			    refname) == -1)
395 				return got_error_from_errno("asprintf");
396 			err = parse_packed_ref_line(ref, abs_refname, line,
397 			    mtime);
398 			if (!ref_is_absolute)
399 				free(abs_refname);
400 			if (err || *ref != NULL)
401 				break;
402 		}
403 		if (err)
404 			break;
405 	} while (*ref == NULL);
406 	free(line);
407 
408 	return err;
409 }
410 
411 static const struct got_error *
412 open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
413     const char *name, int lock)
414 {
415 	const struct got_error *err = NULL;
416 	char *path = NULL;
417 	char *absname = NULL;
418 	int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
419 	int ref_is_well_known = (subdir[0] == '\0' && is_well_known_ref(name));
420 
421 	*ref = NULL;
422 
423 	if (!got_ref_name_is_valid(name))
424 		return got_error_path(name, GOT_ERR_BAD_REF_NAME);
425 
426 	if (ref_is_absolute || ref_is_well_known) {
427 		if (asprintf(&path, "%s/%s", path_refs, name) == -1)
428 			return got_error_from_errno("asprintf");
429 		absname = (char *)name;
430 	} else {
431 		if (asprintf(&path, "%s/%s%s%s", path_refs, subdir,
432 		    subdir[0] ? "/" : "", name) == -1)
433 			return got_error_from_errno("asprintf");
434 
435 		if (asprintf(&absname, "refs/%s%s%s",
436 		    subdir, subdir[0] ? "/" : "", name) == -1) {
437 			err = got_error_from_errno("asprintf");
438 			goto done;
439 		}
440 	}
441 
442 	err = parse_ref_file(ref, name, absname, path, lock);
443 done:
444 	if (!ref_is_absolute && !ref_is_well_known)
445 		free(absname);
446 	free(path);
447 	return err;
448 }
449 
450 const struct got_error *
451 got_ref_open(struct got_reference **ref, struct got_repository *repo,
452     const char *refname, int lock)
453 {
454 	const struct got_error *err = NULL;
455 	char *path_refs = NULL;
456 	const char *subdirs[] = {
457 	    GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
458 	};
459 	size_t i;
460 	int well_known = is_well_known_ref(refname);
461 	struct got_lockfile *lf = NULL;
462 
463 	*ref = NULL;
464 
465 	path_refs = get_refs_dir_path(repo, refname);
466 	if (path_refs == NULL) {
467 		err = got_error_from_errno2("get_refs_dir_path", refname);
468 		goto done;
469 	}
470 
471 	if (well_known) {
472 		err = open_ref(ref, path_refs, "", refname, lock);
473 	} else {
474 		char *packed_refs_path;
475 		FILE *f;
476 
477 		/* Search on-disk refs before packed refs! */
478 		for (i = 0; i < nitems(subdirs); i++) {
479 			err = open_ref(ref, path_refs, subdirs[i], refname,
480 			    lock);
481 			if ((err && err->code != GOT_ERR_NOT_REF) || *ref)
482 				goto done;
483 		}
484 
485 		packed_refs_path = got_repo_get_path_packed_refs(repo);
486 		if (packed_refs_path == NULL) {
487 			err = got_error_from_errno(
488 			    "got_repo_get_path_packed_refs");
489 			goto done;
490 		}
491 
492 		if (lock) {
493 			err = got_lockfile_lock(&lf, packed_refs_path, -1);
494 			if (err)
495 				goto done;
496 		}
497 		f = fopen(packed_refs_path, "rb");
498 		free(packed_refs_path);
499 		if (f != NULL) {
500 			struct stat sb;
501 			if (fstat(fileno(f), &sb) == -1) {
502 				err = got_error_from_errno2("fstat",
503 				    packed_refs_path);
504 				goto done;
505 			}
506 			err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
507 			    refname, sb.st_mtime);
508 			if (!err) {
509 				if (fclose(f) == EOF) {
510 					err = got_error_from_errno("fclose");
511 					got_ref_close(*ref);
512 					*ref = NULL;
513 				} else if (*ref)
514 					(*ref)->lf = lf;
515 			}
516 		}
517 	}
518 done:
519 	if (!err && *ref == NULL)
520 		err = got_error_not_ref(refname);
521 	if (err && lf)
522 		got_lockfile_unlock(lf, -1);
523 	free(path_refs);
524 	return err;
525 }
526 
527 void
528 got_ref_close(struct got_reference *ref)
529 {
530 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
531 		free(ref->ref.symref.name);
532 		free(ref->ref.symref.ref);
533 	} else
534 		free(ref->ref.ref.name);
535 	free(ref);
536 }
537 
538 struct got_reference *
539 got_ref_dup(struct got_reference *ref)
540 {
541 	struct got_reference *ret;
542 
543 	ret = calloc(1, sizeof(*ret));
544 	if (ret == NULL)
545 		return NULL;
546 
547 	ret->flags = ref->flags;
548 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
549 		ret->ref.symref.name = strdup(ref->ref.symref.name);
550 		if (ret->ref.symref.name == NULL) {
551 			free(ret);
552 			return NULL;
553 		}
554 		ret->ref.symref.ref = strdup(ref->ref.symref.ref);
555 		if (ret->ref.symref.ref == NULL) {
556 			free(ret->ref.symref.name);
557 			free(ret);
558 			return NULL;
559 		}
560 	} else {
561 		ret->ref.ref.name = strdup(ref->ref.ref.name);
562 		if (ret->ref.ref.name == NULL) {
563 			free(ret);
564 			return NULL;
565 		}
566 		memcpy(ret->ref.ref.sha1, ref->ref.ref.sha1,
567 		    sizeof(ret->ref.ref.sha1));
568 	}
569 
570 	return ret;
571 }
572 
573 const struct got_error *
574 got_reflist_entry_dup(struct got_reflist_entry **newp,
575     struct got_reflist_entry *re)
576 {
577 	const struct got_error *err = NULL;
578 	struct got_reflist_entry *new;
579 
580 	*newp = NULL;
581 
582 	new = malloc(sizeof(*new));
583 	if (new == NULL)
584 		return got_error_from_errno("malloc");
585 
586 	new->ref = got_ref_dup(re->ref);
587 	if (new->ref == NULL) {
588 		err = got_error_from_errno("got_ref_dup");
589 		free(new);
590 		return err;
591 	}
592 
593 	*newp = new;
594 	return NULL;
595 }
596 
597 const struct got_error *
598 got_ref_resolve_symbolic(struct got_reference **resolved,
599     struct got_repository *repo, struct got_reference *ref)
600 {
601 	struct got_reference *nextref;
602 	const struct got_error *err;
603 
604 	err = got_ref_open(&nextref, repo, ref->ref.symref.ref, 0);
605 	if (err)
606 		return err;
607 
608 	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
609 		err = got_ref_resolve_symbolic(resolved, repo, nextref);
610 	else
611 		*resolved = got_ref_dup(nextref);
612 
613 	got_ref_close(nextref);
614 	return err;
615 }
616 
617 static const struct got_error *
618 ref_resolve(struct got_object_id **id, struct got_repository *repo,
619     struct got_reference *ref, int recursion)
620 {
621 	const struct got_error *err;
622 
623 	if (recursion <= 0)
624 		return got_error_msg(GOT_ERR_RECURSION,
625 		    "reference recursion limit reached");
626 
627 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
628 		struct got_reference *resolved = NULL;
629 		err = got_ref_resolve_symbolic(&resolved, repo, ref);
630 		if (err == NULL)
631 			err = ref_resolve(id, repo, resolved, --recursion);
632 		if (resolved)
633 			got_ref_close(resolved);
634 		return err;
635 	}
636 
637 	*id = calloc(1, sizeof(**id));
638 	if (*id == NULL)
639 		return got_error_from_errno("calloc");
640 	memcpy((*id)->sha1, ref->ref.ref.sha1, sizeof((*id)->sha1));
641 	return NULL;
642 }
643 
644 const struct got_error *
645 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
646     struct got_reference *ref)
647 {
648 	return ref_resolve(id, repo, ref, GOT_REF_RECURSE_MAX);
649 }
650 
651 char *
652 got_ref_to_str(struct got_reference *ref)
653 {
654 	char *str;
655 
656 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
657 		return strdup(ref->ref.symref.ref);
658 
659 	str = malloc(SHA1_DIGEST_STRING_LENGTH);
660 	if (str == NULL)
661 		return NULL;
662 
663 	if (got_sha1_digest_to_str(ref->ref.ref.sha1, str,
664 	    SHA1_DIGEST_STRING_LENGTH) == NULL) {
665 		free(str);
666 		return NULL;
667 	}
668 
669 	return str;
670 }
671 
672 const char *
673 got_ref_get_name(struct got_reference *ref)
674 {
675 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
676 		return ref->ref.symref.name;
677 
678 	return ref->ref.ref.name;
679 }
680 
681 const char *
682 got_ref_get_symref_target(struct got_reference *ref)
683 {
684 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
685 		return ref->ref.symref.ref;
686 
687 	return NULL;
688 }
689 
690 time_t
691 got_ref_get_mtime(struct got_reference *ref)
692 {
693 	return ref->mtime;
694 }
695 
696 const struct got_error *
697 got_ref_cmp_by_name(void *arg, int *cmp, struct got_reference *re1,
698     struct got_reference* re2)
699 {
700 	const char *name1 = got_ref_get_name(re1);
701 	const char *name2 = got_ref_get_name(re2);
702 
703 	*cmp = got_path_cmp(name1, name2, strlen(name1), strlen(name2));
704 	return NULL;
705 }
706 
707 const struct got_error *
708 got_ref_cmp_tags(void *arg, int *cmp, struct got_reference *ref1,
709     struct got_reference *ref2)
710 {
711 	const struct got_error *err = NULL;
712 	struct got_repository *repo = arg;
713 	struct got_object_id *id1, *id2 = NULL;
714 	struct got_tag_object *tag1 = NULL, *tag2 = NULL;
715 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
716 	time_t time1, time2;
717 
718 	*cmp = 0;
719 
720 	err = got_ref_resolve(&id1, repo, ref1);
721 	if (err)
722 		return err;
723 	err = got_object_open_as_tag(&tag1, repo, id1);
724 	if (err) {
725 		if (err->code != GOT_ERR_OBJ_TYPE)
726 			goto done;
727 		/* "lightweight" tag */
728 		err = got_object_open_as_commit(&commit1, repo, id1);
729 		if (err)
730 			goto done;
731 		time1 = got_object_commit_get_committer_time(commit1);
732 	} else
733 		time1 = got_object_tag_get_tagger_time(tag1);
734 
735 	err = got_ref_resolve(&id2, repo, ref2);
736 	if (err)
737 		goto done;
738 	err = got_object_open_as_tag(&tag2, repo, id2);
739 	if (err) {
740 		if (err->code != GOT_ERR_OBJ_TYPE)
741 			goto done;
742 		/* "lightweight" tag */
743 		err = got_object_open_as_commit(&commit2, repo, id2);
744 		if (err)
745 			goto done;
746 		time2 = got_object_commit_get_committer_time(commit2);
747 	} else
748 		time2 = got_object_tag_get_tagger_time(tag2);
749 
750 	/* Put latest tags first. */
751 	if (time1 < time2)
752 		*cmp = 1;
753 	else if (time1 > time2)
754 		*cmp = -1;
755 	else
756 		err = got_ref_cmp_by_name(NULL, cmp, ref2, ref1);
757 done:
758 	free(id1);
759 	free(id2);
760 	if (tag1)
761 		got_object_tag_close(tag1);
762 	if (tag2)
763 		got_object_tag_close(tag2);
764 	if (commit1)
765 		got_object_commit_close(commit1);
766 	if (commit2)
767 		got_object_commit_close(commit2);
768 	return err;
769 }
770 
771 const struct got_error *
772 got_ref_cmp_by_commit_timestamp_descending(void *arg, int *cmp,
773     struct got_reference *ref1, struct got_reference *ref2)
774 {
775 	const struct got_error *err;
776 	struct got_repository *repo = arg;
777 	struct got_object_id *id1 = NULL, *id2 = NULL;
778 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
779 
780 	*cmp = 0;
781 
782 	if (ref1->committer_time == 0) {
783 		err = got_ref_resolve(&id1, repo, ref1);
784 		if (err)
785 			return err;
786 		err = got_object_open_as_commit(&commit1, repo, id1);
787 		if (err)
788 			goto done;
789 		ref1->committer_time =
790 		    got_object_commit_get_committer_time(commit1);
791 	}
792 
793 	if (ref2->committer_time == 0) {
794 		err = got_ref_resolve(&id2, repo, ref2);
795 		if (err)
796 			return err;
797 		err = got_object_open_as_commit(&commit2, repo, id2);
798 		if (err)
799 			goto done;
800 		ref2->committer_time =
801 		    got_object_commit_get_committer_time(commit2);
802 	}
803 
804 	if (ref1->committer_time < ref2->committer_time)
805 		*cmp = 1;
806 	else if (ref2->committer_time < ref1->committer_time)
807 		*cmp = -1;
808 done:
809 	free(id1);
810 	free(id2);
811 	if (commit1)
812 		got_object_commit_close(commit1);
813 	if (commit2)
814 		got_object_commit_close(commit2);
815 	return err;
816 }
817 
818 const struct got_error *
819 got_reflist_insert(struct got_reflist_entry **newp, struct got_reflist_head *refs,
820     struct got_reference *ref, got_ref_cmp_cb cmp_cb, void *cmp_arg)
821 {
822 	const struct got_error *err;
823 	struct got_reflist_entry *new, *re;
824 	int cmp;
825 
826 	*newp = NULL;
827 
828 	new = malloc(sizeof(*new));
829 	if (new == NULL)
830 		return got_error_from_errno("malloc");
831 	new->ref = ref;
832 	*newp = new;
833 
834 	/*
835 	 * We must de-duplicate entries on insert because packed-refs may
836 	 * contain redundant entries. On-disk refs take precedence.
837 	 * This code assumes that on-disk revs are read before packed-refs.
838 	 * We're iterating the list anyway, so insert elements sorted by name.
839 	 *
840 	 * Many callers will provide paths in a somewhat sorted order.
841 	 * Iterating backwards from the tail of the list should be more
842 	 * efficient than traversing through the entire list each time
843 	 * an element is inserted.
844 	 */
845 	re = TAILQ_LAST(refs, got_reflist_head);
846 	while (re) {
847 		err = (*cmp_cb)(cmp_arg, &cmp, re->ref, new->ref);
848 		if (err)
849 			return err;
850 		if (cmp == 0) {
851 			/* duplicate */
852 			free(new);
853 			*newp = NULL;
854 			return NULL;
855 		} else if (cmp < 0) {
856 			TAILQ_INSERT_AFTER(refs, re, new, entry);
857 			return NULL;
858 		}
859 		re = TAILQ_PREV(re, got_reflist_head, entry);
860 	}
861 
862 	TAILQ_INSERT_HEAD(refs, new, entry);
863 	return NULL;
864 }
865 
866 static const struct got_error *
867 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
868     const char *subdir, struct got_repository *repo,
869     got_ref_cmp_cb cmp_cb, void *cmp_arg)
870 {
871 	const struct got_error *err = NULL;
872 	DIR *d = NULL;
873 	char *path_subdir;
874 
875 	while (subdir[0] == '/')
876 		subdir++;
877 
878 	if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
879 		return got_error_from_errno("asprintf");
880 
881 	d = opendir(path_subdir);
882 	if (d == NULL)
883 		goto done;
884 
885 	for (;;) {
886 		struct dirent *dent;
887 		struct got_reference *ref;
888 		char *child;
889 		int type;
890 
891 		dent = readdir(d);
892 		if (dent == NULL)
893 			break;
894 
895 		if (strcmp(dent->d_name, ".") == 0 ||
896 		    strcmp(dent->d_name, "..") == 0)
897 			continue;
898 
899 		err = got_path_dirent_type(&type, path_subdir, dent);
900 		if (err)
901 			break;
902 
903 		switch (type) {
904 		case DT_REG:
905 			err = open_ref(&ref, path_refs, subdir, dent->d_name,
906 			    0);
907 			if (err)
908 				goto done;
909 			if (ref) {
910 				struct got_reflist_entry *new;
911 				err = got_reflist_insert(&new, refs, ref,
912 				    cmp_cb, cmp_arg);
913 				if (err || new == NULL /* duplicate */)
914 					got_ref_close(ref);
915 				if (err)
916 					goto done;
917 			}
918 			break;
919 		case DT_DIR:
920 			if (asprintf(&child, "%s%s%s", subdir,
921 			    subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
922 				err = got_error_from_errno("asprintf");
923 				break;
924 			}
925 			err = gather_on_disk_refs(refs, path_refs, child, repo,
926 			    cmp_cb, cmp_arg);
927 			free(child);
928 			break;
929 		default:
930 			break;
931 		}
932 	}
933 done:
934 	if (d)
935 		closedir(d);
936 	free(path_subdir);
937 	return err;
938 }
939 
940 const struct got_error *
941 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo,
942     const char *ref_namespace, got_ref_cmp_cb cmp_cb, void *cmp_arg)
943 {
944 	const struct got_error *err;
945 	char *packed_refs_path, *path_refs = NULL;
946 	char *abs_namespace = NULL;
947 	char *buf = NULL, *ondisk_ref_namespace = NULL;
948 	char *line = NULL;
949 	FILE *f = NULL;
950 	struct got_reference *ref;
951 	struct got_reflist_entry *new;
952 
953 	if (ref_namespace == NULL || ref_namespace[0] == '\0') {
954 		path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
955 		if (path_refs == NULL) {
956 			err = got_error_from_errno("get_refs_dir_path");
957 			goto done;
958 		}
959 		err = open_ref(&ref, path_refs, "", GOT_REF_HEAD, 0);
960 		if (err)
961 			goto done;
962 		err = got_reflist_insert(&new, refs, ref, cmp_cb, cmp_arg);
963 		if (err || new == NULL /* duplicate */)
964 			got_ref_close(ref);
965 		if (err && err->code != GOT_ERR_NOT_REF)
966 			goto done;
967 	} else {
968 		/* Try listing a single reference. */
969 		const char *refname = ref_namespace;
970 		path_refs = get_refs_dir_path(repo, refname);
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, "", refname, 0);
976 		if (err) {
977 			if (err->code != GOT_ERR_NOT_REF)
978 				goto done;
979 			/* Try to look up references in a given namespace. */
980 		} else {
981 			err = got_reflist_insert(&new, refs, ref,
982 			    cmp_cb, cmp_arg);
983 			if (err || new == NULL /* duplicate */)
984 				got_ref_close(ref);
985 			return err;
986 		}
987 	}
988 
989 	if (ref_namespace) {
990 		size_t len;
991 		/* Canonicalize the path to eliminate double-slashes if any. */
992 		if (asprintf(&abs_namespace, "/%s", ref_namespace) == -1) {
993 			err = got_error_from_errno("asprintf");
994 			goto done;
995 		}
996 		len = strlen(abs_namespace) + 1;
997 		buf = malloc(len);
998 		if (buf == NULL) {
999 			err = got_error_from_errno("malloc");
1000 			goto done;
1001 		}
1002 		err = got_canonpath(abs_namespace, buf, len);
1003 		if (err)
1004 			goto done;
1005 		ondisk_ref_namespace = buf;
1006 		while (ondisk_ref_namespace[0] == '/')
1007 			ondisk_ref_namespace++;
1008 		if (strncmp(ondisk_ref_namespace, "refs/", 5) == 0)
1009 			ondisk_ref_namespace += 5;
1010 		else if (strcmp(ondisk_ref_namespace, "refs") == 0)
1011 			ondisk_ref_namespace = "";
1012 	}
1013 
1014 	/* Gather on-disk refs before parsing packed-refs. */
1015 	free(path_refs);
1016 	path_refs = get_refs_dir_path(repo, "");
1017 	if (path_refs == NULL) {
1018 		err = got_error_from_errno("get_refs_dir_path");
1019 		goto done;
1020 	}
1021 	err = gather_on_disk_refs(refs, path_refs,
1022 	    ondisk_ref_namespace ? ondisk_ref_namespace : "", repo,
1023 	    cmp_cb, cmp_arg);
1024 	if (err)
1025 		goto done;
1026 
1027 	/*
1028 	 * The packed-refs file may contain redundant entries, in which
1029 	 * case on-disk refs take precedence.
1030 	 */
1031 	packed_refs_path = got_repo_get_path_packed_refs(repo);
1032 	if (packed_refs_path == NULL) {
1033 		err = got_error_from_errno("got_repo_get_path_packed_refs");
1034 		goto done;
1035 	}
1036 
1037 	f = fopen(packed_refs_path, "r");
1038 	free(packed_refs_path);
1039 	if (f) {
1040 		size_t linesize = 0;
1041 		ssize_t linelen;
1042 		struct stat sb;
1043 
1044 		if (fstat(fileno(f), &sb) == -1) {
1045 			err = got_error_from_errno2("fstat", packed_refs_path);
1046 			goto done;
1047 		}
1048 		for (;;) {
1049 			linelen = getline(&line, &linesize, f);
1050 			if (linelen == -1) {
1051 				if (feof(f))
1052 					break;
1053 				err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1054 				goto done;
1055 			}
1056 			if (linelen > 0 && line[linelen - 1] == '\n')
1057 				line[linelen - 1] = '\0';
1058 			err = parse_packed_ref_line(&ref, NULL, line,
1059 			    sb.st_mtime);
1060 			if (err)
1061 				goto done;
1062 			if (ref) {
1063 				if (ref_namespace) {
1064 					const char *name;
1065 					name = got_ref_get_name(ref);
1066 					if (!got_path_is_child(name,
1067 					    ref_namespace,
1068 					    strlen(ref_namespace))) {
1069 						got_ref_close(ref);
1070 						continue;
1071 					}
1072 				}
1073 				err = got_reflist_insert(&new, refs, ref,
1074 				    cmp_cb, cmp_arg);
1075 				if (err || new == NULL /* duplicate */)
1076 					got_ref_close(ref);
1077 				if (err)
1078 					goto done;
1079 			}
1080 		}
1081 	}
1082 done:
1083 	free(abs_namespace);
1084 	free(buf);
1085 	free(line);
1086 	free(path_refs);
1087 	if (f && fclose(f) == EOF && err == NULL)
1088 		err = got_error_from_errno("fclose");
1089 	return err;
1090 }
1091 
1092 void
1093 got_ref_list_free(struct got_reflist_head *refs)
1094 {
1095 	struct got_reflist_entry *re;
1096 
1097 	while ((re = TAILQ_FIRST(refs))) {
1098 		TAILQ_REMOVE(refs, re, entry);
1099 		got_ref_close(re->ref);
1100 		free(re);
1101 	}
1102 
1103 }
1104 
1105 int
1106 got_ref_is_symbolic(struct got_reference *ref)
1107 {
1108 	return (ref->flags & GOT_REF_IS_SYMBOLIC);
1109 }
1110 
1111 const struct got_error *
1112 got_ref_change_ref(struct got_reference *ref, struct got_object_id *id)
1113 {
1114 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
1115 		return got_error(GOT_ERR_BAD_REF_TYPE);
1116 
1117 	memcpy(ref->ref.ref.sha1, id->sha1, sizeof(ref->ref.ref.sha1));
1118 	return NULL;
1119 }
1120 
1121 const struct got_error *
1122 got_ref_change_symref(struct got_reference *ref, const char *refname)
1123 {
1124 	char *new_name;
1125 
1126 	if ((ref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1127 		return got_error(GOT_ERR_BAD_REF_TYPE);
1128 
1129 	new_name = strdup(refname);
1130 	if (new_name == NULL)
1131 		return got_error_from_errno("strdup");
1132 
1133 	free(ref->ref.symref.ref);
1134 	ref->ref.symref.ref = new_name;
1135 	return NULL;
1136 }
1137 
1138 const struct got_error *
1139 got_ref_change_symref_to_ref(struct got_reference *symref,
1140     struct got_object_id *id)
1141 {
1142 	if ((symref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1143 		return got_error(GOT_ERR_BAD_REF_TYPE);
1144 
1145 	symref->ref.ref.name = symref->ref.symref.name;
1146 	memcpy(symref->ref.ref.sha1, id->sha1, SHA1_DIGEST_LENGTH);
1147 	symref->flags &= ~GOT_REF_IS_SYMBOLIC;
1148 	return NULL;
1149 }
1150 
1151 const struct got_error *
1152 got_ref_write(struct got_reference *ref, struct got_repository *repo)
1153 {
1154 	const struct got_error *err = NULL, *unlock_err = NULL;
1155 	const char *name = got_ref_get_name(ref);
1156 	char *path_refs = NULL, *path = NULL, *tmppath = NULL;
1157 	struct got_lockfile *lf = NULL;
1158 	FILE *f = NULL;
1159 	size_t n;
1160 	struct stat sb;
1161 
1162 	path_refs = get_refs_dir_path(repo, name);
1163 	if (path_refs == NULL) {
1164 		err = got_error_from_errno2("get_refs_dir_path", name);
1165 		goto done;
1166 	}
1167 
1168 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1169 		err = got_error_from_errno("asprintf");
1170 		goto done;
1171 	}
1172 
1173 	err = got_opentemp_named(&tmppath, &f, path);
1174 	if (err) {
1175 		char *parent;
1176 		if (!(err->code == GOT_ERR_ERRNO && errno == ENOENT))
1177 			goto done;
1178 		err = got_path_dirname(&parent, path);
1179 		if (err)
1180 			goto done;
1181 		err = got_path_mkdir(parent);
1182 		free(parent);
1183 		if (err)
1184 			goto done;
1185 		err = got_opentemp_named(&tmppath, &f, path);
1186 		if (err)
1187 			goto done;
1188 	}
1189 
1190 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
1191 		n = fprintf(f, "ref: %s\n", ref->ref.symref.ref);
1192 		if (n != strlen(ref->ref.symref.ref) + 6) {
1193 			err = got_ferror(f, GOT_ERR_IO);
1194 			goto done;
1195 		}
1196 	} else {
1197 		char hex[SHA1_DIGEST_STRING_LENGTH];
1198 		if (got_sha1_digest_to_str(ref->ref.ref.sha1, hex,
1199 		    sizeof(hex)) == NULL) {
1200 			err = got_error(GOT_ERR_BAD_REF_DATA);
1201 			goto done;
1202 		}
1203 		n = fprintf(f, "%s\n", hex);
1204 		if (n != sizeof(hex)) {
1205 			err = got_ferror(f, GOT_ERR_IO);
1206 			goto done;
1207 		}
1208 	}
1209 
1210 	if (ref->lf == NULL) {
1211 		err = got_lockfile_lock(&lf, path, -1);
1212 		if (err)
1213 			goto done;
1214 	}
1215 
1216 	/* XXX: check if old content matches our expectations? */
1217 
1218 	if (stat(path, &sb) != 0) {
1219 		if (errno != ENOENT) {
1220 			err = got_error_from_errno2("stat", path);
1221 			goto done;
1222 		}
1223 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
1224 	}
1225 
1226 	if (fchmod(fileno(f), sb.st_mode) != 0) {
1227 		err = got_error_from_errno2("fchmod", tmppath);
1228 		goto done;
1229 	}
1230 
1231 	if (rename(tmppath, path) != 0) {
1232 		err = got_error_from_errno3("rename", tmppath, path);
1233 		goto done;
1234 	}
1235 	free(tmppath);
1236 	tmppath = NULL;
1237 
1238 	if (stat(path, &sb) == -1) {
1239 		err = got_error_from_errno2("stat", path);
1240 		goto done;
1241 	}
1242 	ref->mtime = sb.st_mtime;
1243 done:
1244 	if (ref->lf == NULL && lf)
1245 		unlock_err = got_lockfile_unlock(lf, -1);
1246 	if (f) {
1247 		if (fclose(f) == EOF && err == NULL)
1248 			err = got_error_from_errno("fclose");
1249 	}
1250 	free(path_refs);
1251 	free(path);
1252 	if (tmppath) {
1253 		if (unlink(tmppath) != 0 && err == NULL)
1254 			err = got_error_from_errno2("unlink", tmppath);
1255 		free(tmppath);
1256 	}
1257 	return err ? err : unlock_err;
1258 }
1259 
1260 static const struct got_error *
1261 delete_packed_ref(struct got_reference *delref, struct got_repository *repo)
1262 {
1263 	const struct got_error *err = NULL, *unlock_err = NULL;
1264 	struct got_lockfile *lf = NULL;
1265 	FILE *f = NULL, *tmpf = NULL;
1266 	char *line = NULL, *packed_refs_path, *tmppath = NULL;
1267 	size_t linesize = 0;
1268 	struct got_reflist_head refs;
1269 	int found_delref = 0;
1270 
1271 	/* The packed-refs file does not cotain symbolic references. */
1272 	if (delref->flags & GOT_REF_IS_SYMBOLIC)
1273 		return got_error(GOT_ERR_BAD_REF_DATA);
1274 
1275 	TAILQ_INIT(&refs);
1276 
1277 	packed_refs_path = got_repo_get_path_packed_refs(repo);
1278 	if (packed_refs_path == NULL)
1279 		return got_error_from_errno("got_repo_get_path_packed_refs");
1280 
1281 	err = got_opentemp_named(&tmppath, &tmpf, packed_refs_path);
1282 	if (err)
1283 		goto done;
1284 
1285 	if (delref->lf == NULL) {
1286 		err = got_lockfile_lock(&lf, packed_refs_path, -1);
1287 		if (err)
1288 			goto done;
1289 	}
1290 
1291 	f = fopen(packed_refs_path, "r");
1292 	if (f == NULL) {
1293 		err = got_error_from_errno2("fopen", packed_refs_path);
1294 		goto done;
1295 	}
1296 	for (;;) {
1297 		ssize_t linelen;
1298 		struct got_reference *ref;
1299 		struct got_reflist_entry *new;
1300 
1301 		linelen = getline(&line, &linesize, f);
1302 		if (linelen == -1) {
1303 			if (feof(f))
1304 				break;
1305 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1306 			goto done;
1307 		}
1308 		if (linelen > 0 && line[linelen - 1] == '\n')
1309 			line[linelen - 1] = '\0';
1310 		err = parse_packed_ref_line(&ref, NULL, line, 0);
1311 		if (err)
1312 			goto done;
1313 		if (ref == NULL)
1314 			continue;
1315 
1316 		if (strcmp(ref->ref.ref.name, delref->ref.ref.name) == 0 &&
1317 		    memcmp(ref->ref.ref.sha1, delref->ref.ref.sha1,
1318 		    sizeof(delref->ref.ref.sha1)) == 0) {
1319 			found_delref = 1;
1320 			got_ref_close(ref);
1321 			continue;
1322 		}
1323 
1324 		err = got_reflist_insert(&new, &refs, ref,
1325 		    got_ref_cmp_by_name, NULL);
1326 		if (err || new == NULL /* duplicate */)
1327 			got_ref_close(ref);
1328 		if (err)
1329 			goto done;
1330 	}
1331 
1332 	if (found_delref) {
1333 		struct got_reflist_entry *re;
1334 		size_t n;
1335 		struct stat sb;
1336 
1337 		n = fprintf(tmpf, "%s\n", GOT_PACKED_REFS_HEADER);
1338 		if (n != sizeof(GOT_PACKED_REFS_HEADER)) {
1339 			err = got_ferror(f, GOT_ERR_IO);
1340 			goto done;
1341 		}
1342 
1343 		TAILQ_FOREACH(re, &refs, entry) {
1344 			char hex[SHA1_DIGEST_STRING_LENGTH];
1345 
1346 			if (got_sha1_digest_to_str(re->ref->ref.ref.sha1, hex,
1347 			    sizeof(hex)) == NULL) {
1348 				err = got_error(GOT_ERR_BAD_REF_DATA);
1349 				goto done;
1350 			}
1351 			n = fprintf(tmpf, "%s ", hex);
1352 			if (n != sizeof(hex)) {
1353 				err = got_ferror(f, GOT_ERR_IO);
1354 				goto done;
1355 			}
1356 			n = fprintf(tmpf, "%s\n", re->ref->ref.ref.name);
1357 			if (n != strlen(re->ref->ref.ref.name) + 1) {
1358 				err = got_ferror(f, GOT_ERR_IO);
1359 				goto done;
1360 			}
1361 		}
1362 
1363 		if (fflush(tmpf) != 0) {
1364 			err = got_error_from_errno("fflush");
1365 			goto done;
1366 		}
1367 
1368 		if (fstat(fileno(f), &sb) != 0) {
1369 			if (errno != ENOENT) {
1370 				err = got_error_from_errno2("fstat",
1371 				    packed_refs_path);
1372 				goto done;
1373 			}
1374 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1375 		}
1376 
1377 		if (fchmod(fileno(tmpf), sb.st_mode) != 0) {
1378 			err = got_error_from_errno2("fchmod", tmppath);
1379 			goto done;
1380 		}
1381 
1382 		if (rename(tmppath, packed_refs_path) != 0) {
1383 			err = got_error_from_errno3("rename", tmppath,
1384 			    packed_refs_path);
1385 			goto done;
1386 		}
1387 	}
1388 done:
1389 	if (delref->lf == NULL && lf)
1390 		unlock_err = got_lockfile_unlock(lf, -1);
1391 	if (f) {
1392 		if (fclose(f) == EOF && err == NULL)
1393 			err = got_error_from_errno("fclose");
1394 	}
1395 	if (tmpf) {
1396 		unlink(tmppath);
1397 		if (fclose(tmpf) == EOF && err == NULL)
1398 			err = got_error_from_errno("fclose");
1399 	}
1400 	free(tmppath);
1401 	free(packed_refs_path);
1402 	free(line);
1403 	got_ref_list_free(&refs);
1404 	return err ? err : unlock_err;
1405 }
1406 
1407 static const struct got_error *
1408 delete_loose_ref(struct got_reference *ref, struct got_repository *repo)
1409 {
1410 	const struct got_error *err = NULL, *unlock_err = NULL;
1411 	const char *name = got_ref_get_name(ref);
1412 	char *path_refs = NULL, *path = NULL;
1413 	struct got_lockfile *lf = NULL;
1414 
1415 	path_refs = get_refs_dir_path(repo, name);
1416 	if (path_refs == NULL) {
1417 		err = got_error_from_errno2("get_refs_dir_path", name);
1418 		goto done;
1419 	}
1420 
1421 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1422 		err = got_error_from_errno("asprintf");
1423 		goto done;
1424 	}
1425 
1426 	if (ref->lf == NULL) {
1427 		err = got_lockfile_lock(&lf, path, -1);
1428 		if (err)
1429 			goto done;
1430 	}
1431 
1432 	/* XXX: check if old content matches our expectations? */
1433 
1434 	if (unlink(path) != 0)
1435 		err = got_error_from_errno2("unlink", path);
1436 done:
1437 	if (ref->lf == NULL && lf)
1438 		unlock_err = got_lockfile_unlock(lf, -1);
1439 
1440 	free(path_refs);
1441 	free(path);
1442 	return err ? err : unlock_err;
1443 }
1444 
1445 const struct got_error *
1446 got_ref_delete(struct got_reference *ref, struct got_repository *repo)
1447 {
1448 	const struct got_error *err = NULL;
1449 	struct got_reference *ref2;
1450 
1451 	if (ref->flags & GOT_REF_IS_PACKED) {
1452 		err = delete_packed_ref(ref, repo);
1453 		if (err)
1454 			return err;
1455 
1456 		err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1457 		if (err) {
1458 			if (err->code == GOT_ERR_NOT_REF)
1459 				return NULL;
1460 			return err;
1461 		}
1462 
1463 		err = delete_loose_ref(ref2, repo);
1464 		got_ref_close(ref2);
1465 		return err;
1466 	} else {
1467 		err = delete_loose_ref(ref, repo);
1468 		if (err)
1469 			return err;
1470 
1471 		err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1472 		if (err) {
1473 			if (err->code == GOT_ERR_NOT_REF)
1474 				return NULL;
1475 			return err;
1476 		}
1477 
1478 		err = delete_packed_ref(ref2, repo);
1479 		got_ref_close(ref2);
1480 		return err;
1481 	}
1482 }
1483 
1484 const struct got_error *
1485 got_ref_unlock(struct got_reference *ref)
1486 {
1487 	const struct got_error *err;
1488 	err = got_lockfile_unlock(ref->lf, -1);
1489 	ref->lf = NULL;
1490 	return err;
1491 }
1492 
1493 struct got_reflist_object_id_map {
1494 	struct got_object_idset *idset;
1495 };
1496 
1497 struct got_reflist_object_id_map_entry {
1498 	struct got_reflist_head refs;
1499 };
1500 
1501 static const struct got_error *
1502 add_object_id_map_entry(struct got_object_idset *idset,
1503     struct got_object_id *id, struct got_reflist_entry *re)
1504 {
1505 	const struct got_error *err = NULL;
1506 	struct got_reflist_object_id_map_entry *ent;
1507 	struct got_reflist_entry *new;
1508 
1509 	ent = got_object_idset_get(idset, id);
1510 	if (ent == NULL) {
1511 		ent = malloc(sizeof(*ent));
1512 		if (ent == NULL)
1513 			return got_error_from_errno("malloc");
1514 
1515 		TAILQ_INIT(&ent->refs);
1516 		err = got_object_idset_add(idset, id, ent);
1517 		if (err)
1518 			return err;
1519 	}
1520 
1521 	err = got_reflist_entry_dup(&new, re);
1522 	if (err)
1523 		return err;
1524 
1525 	TAILQ_INSERT_TAIL(&ent->refs, new, entry);
1526 	return NULL;
1527 }
1528 
1529 const struct got_error *
1530 got_reflist_object_id_map_create(struct got_reflist_object_id_map **map,
1531     struct got_reflist_head *refs, struct got_repository *repo)
1532 {
1533 	const struct got_error *err = NULL;
1534 	struct got_object_idset *idset;
1535 	struct got_object_id *id = NULL;
1536 	struct got_reflist_entry *re;
1537 
1538 	idset = got_object_idset_alloc();
1539 	if (idset == NULL)
1540 		return got_error_from_errno("got_object_idset_alloc");
1541 
1542 	*map = malloc(sizeof(**map));
1543 	if (*map == NULL) {
1544 		got_object_idset_free(idset);
1545 		return got_error_from_errno("malloc");
1546 	}
1547 	(*map)->idset = idset;
1548 
1549 	TAILQ_FOREACH(re, refs, entry) {
1550 		struct got_tag_object *tag = NULL;
1551 
1552 		err = got_ref_resolve(&id, repo, re->ref);
1553 		if (err)
1554 			goto done;
1555 
1556 		err = add_object_id_map_entry(idset, id, re);
1557 		if (err)
1558 			goto done;
1559 
1560 		if (strstr(got_ref_get_name(re->ref), "/tags/") == NULL) {
1561 			free(id);
1562 			id = NULL;
1563 			continue;
1564 		}
1565 
1566 		err = got_object_open_as_tag(&tag, repo, id);
1567 		if (err) {
1568 			if (err->code != GOT_ERR_OBJ_TYPE)
1569 				goto done;
1570 			/* Ref points at something other than a tag. */
1571 			err = NULL;
1572 			tag = NULL;
1573 			free(id);
1574 			id = NULL;
1575 			continue;
1576 		}
1577 
1578 		err = add_object_id_map_entry(idset,
1579 		    got_object_tag_get_object_id(tag), re);
1580 		got_object_tag_close(tag);
1581 		if (err)
1582 			goto done;
1583 
1584 		free(id);
1585 		id = NULL;
1586 	}
1587 done:
1588 	free(id);
1589 	if (err) {
1590 		got_reflist_object_id_map_free(*map);
1591 		*map = NULL;
1592 	}
1593 	return err;
1594 }
1595 
1596 struct got_reflist_head *
1597 got_reflist_object_id_map_lookup(struct got_reflist_object_id_map *map,
1598     struct got_object_id *id)
1599 {
1600 	struct got_reflist_object_id_map_entry *ent;
1601 	ent = got_object_idset_get(map->idset, id);
1602 	if (ent)
1603 		return &ent->refs;
1604 	return NULL;
1605 }
1606 
1607 static const struct got_error *
1608 free_id_map_entry(struct got_object_id *id, void *data, void *arg)
1609 {
1610 	struct got_reflist_object_id_map_entry *ent = data;
1611 
1612 	got_ref_list_free(&ent->refs);
1613 	free(ent);
1614 	return NULL;
1615 }
1616 
1617 void
1618 got_reflist_object_id_map_free(struct got_reflist_object_id_map *map)
1619 {
1620 	got_object_idset_for_each(map->idset, free_id_map_entry, NULL);
1621 	got_object_idset_free(map->idset);
1622 	free(map);
1623 }