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Date:: Mon May 13 21:30:57 2019 UTC
Message:: revert c191ed664f6c437ebc3e0c859c53e48b445401f1 'got ref' should only work with naked ref names; implicitly putting things into 'refs/heads' is a job for something like a 'got branch' command.
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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 <ctype.h>
23 #include <dirent.h>
24 #include <sha1.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <util.h>
29 #include <zlib.h>
30 #include <time.h>
31 #include <libgen.h>
32 
33 #include "got_error.h"
34 #include "got_object.h"
35 #include "got_repository.h"
36 #include "got_reference.h"
37 #include "got_opentemp.h"
38 #include "got_path.h"
39 
40 #include "got_lib_sha1.h"
41 #include "got_lib_delta.h"
42 #include "got_lib_inflate.h"
43 #include "got_lib_object.h"
44 #include "got_lib_lockfile.h"
45 
46 #ifndef nitems
47 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
48 #endif
49 
50 #define GOT_REF_HEADS	"heads"
51 #define GOT_REF_TAGS	"tags"
52 #define GOT_REF_REMOTES	"remotes"
53 
54 /*
55  * We do not resolve tags yet, and don't yet care about sorting refs either,
56  * so packed-refs files we write contain a minimal header which disables all
57  * packed-refs "traits" supported by Git.
58  */
59 #define GOT_PACKED_REFS_HEADER	"# pack-refs with:"
60 
61 /* A symbolic reference. */
62 struct got_symref {
63 	char *name;
64 	char *ref;
65 };
66 
67 /* A non-symbolic reference (there is no better designation). */
68 struct got_ref {
69 	char *name;
70 	u_int8_t sha1[SHA1_DIGEST_LENGTH];
71 };
72 
73 /* A reference which points to an arbitrary object. */
74 struct got_reference {
75 	unsigned int flags;
76 #define GOT_REF_IS_SYMBOLIC	0x01
77 #define GOT_REF_IS_PACKED	0x02
78 
79 	union {
80 		struct got_ref ref;
81 		struct got_symref symref;
82 	} ref;
83 
84 	struct got_lockfile *lf;
85 };
86 
87 static const struct got_error *
88 alloc_ref(struct got_reference **ref, const char *name,
89     struct got_object_id *id, int flags)
90 {
91 	const struct got_error *err = NULL;
92 
93 	*ref = calloc(1, sizeof(**ref));
94 	if (*ref == NULL)
95 		return got_error_from_errno("calloc");
96 
97 	memcpy((*ref)->ref.ref.sha1, id->sha1, sizeof((*ref)->ref.ref.sha1));
98 	(*ref)->flags = flags;
99 	(*ref)->ref.ref.name = strdup(name);
100 	if ((*ref)->ref.ref.name == NULL) {
101 		err = got_error_from_errno("strdup");
102 		got_ref_close(*ref);
103 		*ref = NULL;
104 	}
105 	return err;
106 }
107 
108 static const struct got_error *
109 alloc_symref(struct got_reference **ref, const char *name,
110     const char *target_ref, int flags)
111 {
112 	const struct got_error *err = NULL;
113 
114 	*ref = calloc(1, sizeof(**ref));
115 	if (*ref == NULL)
116 		return got_error_from_errno("calloc");
117 
118 	(*ref)->flags = GOT_REF_IS_SYMBOLIC | flags;
119 	(*ref)->ref.symref.name = strdup(name);
120 	if ((*ref)->ref.symref.name == NULL) {
121 		err = got_error_from_errno("strdup");
122 		got_ref_close(*ref);
123 		*ref = NULL;
124 	}
125 	(*ref)->ref.symref.ref = strdup(target_ref);
126 	if ((*ref)->ref.symref.ref == NULL) {
127 		err = got_error_from_errno("strdup");
128 		got_ref_close(*ref);
129 		*ref = NULL;
130 	}
131 	return err;
132 }
133 
134 static const struct got_error *
135 parse_symref(struct got_reference **ref, const char *name, const char *line)
136 {
137 	if (line[0] == '\0')
138 		return got_error(GOT_ERR_BAD_REF_DATA);
139 
140 	return alloc_symref(ref, name, line, 0);
141 }
142 
143 static const struct got_error *
144 parse_ref_line(struct got_reference **ref, const char *name, const char *line)
145 {
146 	struct got_object_id id;
147 
148 	if (strncmp(line, "ref: ", 5) == 0) {
149 		line += 5;
150 		return parse_symref(ref, name, line);
151 	}
152 
153 	if (!got_parse_sha1_digest(id.sha1, line))
154 		return got_error(GOT_ERR_BAD_REF_DATA);
155 
156 	return alloc_ref(ref, name, &id, 0);
157 }
158 
159 static const struct got_error *
160 parse_ref_file(struct got_reference **ref, const char *name,
161     const char *abspath, int lock)
162 {
163 	const struct got_error *err = NULL;
164 	FILE *f;
165 	char *line;
166 	size_t len;
167 	const char delim[3] = {'\0', '\0', '\0'};
168 	struct got_lockfile *lf = NULL;
169 
170 	if (lock) {
171 		err = got_lockfile_lock(&lf, abspath);
172 		if (err)
173 			return (err);
174 	}
175 
176 	f = fopen(abspath, "rb");
177 	if (f == NULL) {
178 		if (lock)
179 			got_lockfile_unlock(lf);
180 		return NULL;
181 	}
182 
183 	line = fparseln(f, &len, NULL, delim, 0);
184 	if (line == NULL) {
185 		err = got_error(GOT_ERR_BAD_REF_DATA);
186 		if (lock)
187 			got_lockfile_unlock(lf);
188 		goto done;
189 	}
190 
191 	err = parse_ref_line(ref, name, line);
192 	if (lock) {
193 		if (err)
194 			got_lockfile_unlock(lf);
195 		else {
196 			if (*ref)
197 				(*ref)->lf = lf;
198 			else
199 				got_lockfile_unlock(lf);
200 		}
201 	}
202 done:
203 	free(line);
204 	if (fclose(f) != 0 && err == NULL) {
205 		err = got_error_from_errno("fclose");
206 		if (*ref) {
207 			if (lock)
208 				got_ref_unlock(*ref);
209 			got_ref_close(*ref);
210 			*ref = NULL;
211 		}
212 	}
213 	return err;
214 }
215 
216 static int
217 is_well_known_ref(const char *refname)
218 {
219 	return (strcmp(refname, GOT_REF_HEAD) == 0 ||
220 	    strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
221 	    strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
222 	    strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
223 }
224 
225 static char *
226 get_refs_dir_path(struct got_repository *repo, const char *refname)
227 {
228 	if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
229 		return strdup(got_repo_get_path_git_dir(repo));
230 
231 	return got_repo_get_path_refs(repo);
232 }
233 
234 static int
235 is_valid_ref_name(const char *name)
236 {
237 	const char *s, *slash, *seg;
238 	const char forbidden[] = { ' ', '~', '^', ':', '?', '*', '[' , '\\' };
239 	const char *forbidden_seq[] = { "//", "..", "@{" };
240 	const char *lfs = GOT_LOCKFILE_SUFFIX;
241 	const size_t lfs_len = sizeof(GOT_LOCKFILE_SUFFIX) - 1;
242 	int i;
243 
244 	if (name[0] == '@' && name[1] == '\0')
245 		return 0;
246 
247 	slash = strchr(name, '/');
248 	if (slash == NULL)
249 		return 0;
250 
251 	s = name;
252 	seg = s;
253 	if (seg[0] == '\0' || seg[0] == '.' || seg[0] == '/')
254 		return 0;
255 	while (*s) {
256 		for (i = 0; i < nitems(forbidden); i++) {
257 			if (*s == forbidden[i])
258 				return 0;
259 		}
260 		for (i = 0; i < nitems(forbidden_seq); i++) {
261 			if (s[0] == forbidden_seq[i][0] &&
262 			    s[1] == forbidden_seq[i][1])
263 				return 0;
264 		}
265 		if (iscntrl((unsigned char)s[0]))
266 			return 0;
267 		if (s[0] == '.' && s[1] == '\0')
268 			return 0;
269 		if (*s == '/') {
270 			const char *nextseg = s + 1;
271 			if (nextseg[0] == '\0' || nextseg[0] == '.' ||
272 			    nextseg[0] == '/')
273 				return 0;
274 			if (seg <= s - lfs_len &&
275 			    strncmp(s - lfs_len, lfs, lfs_len) == 0)
276 				return 0;
277 			seg = nextseg;
278 		}
279 		s++;
280 	}
281 
282 	if (seg <= s - lfs_len &&
283 	    strncmp(s - lfs_len, lfs, lfs_len) == 0)
284 		return 0;
285 
286 	return 1;
287 }
288 
289 const struct got_error *
290 got_ref_alloc(struct got_reference **ref, const char *name,
291     struct got_object_id *id)
292 {
293 	if (!is_valid_ref_name(name))
294 		return got_error(GOT_ERR_BAD_REF_NAME);
295 
296 	return alloc_ref(ref, name, id, 0);
297 }
298 
299 static const struct got_error *
300 parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
301     const char *line)
302 {
303 	struct got_object_id id;
304 	const char *name;
305 
306 	*ref = NULL;
307 
308 	if (line[0] == '#' || line[0] == '^')
309 		return NULL;
310 
311 	if (!got_parse_sha1_digest(id.sha1, line))
312 		return got_error(GOT_ERR_BAD_REF_DATA);
313 
314 	if (abs_refname) {
315 		if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
316 			return NULL;
317 		name = abs_refname;
318 	} else
319 		name = line + SHA1_DIGEST_STRING_LENGTH;
320 
321 	return alloc_ref(ref, name, &id, GOT_REF_IS_PACKED);
322 }
323 
324 static const struct got_error *
325 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
326     int nsubdirs, const char *refname)
327 {
328 	const struct got_error *err = NULL;
329 	char *abs_refname;
330 	char *line;
331 	size_t len;
332 	const char delim[3] = {'\0', '\0', '\0'};
333 	int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
334 
335 	*ref = NULL;
336 
337 	if (ref_is_absolute)
338 		abs_refname = (char *)refname;
339 	do {
340 		line = fparseln(f, &len, NULL, delim, 0);
341 		if (line == NULL) {
342 			if (feof(f))
343 				break;
344 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
345 			break;
346 		}
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 			if (!ref_is_absolute)
354 				free(abs_refname);
355 			if (err || *ref != NULL)
356 				break;
357 		}
358 		free(line);
359 		if (err)
360 			break;
361 	} while (*ref == NULL);
362 
363 	return err;
364 }
365 
366 static const struct got_error *
367 open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
368     const char *name, int lock)
369 {
370 	const struct got_error *err = NULL;
371 	char *path = NULL;
372 	char *normpath = NULL;
373 	char *absname = NULL;
374 	int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
375 	int ref_is_well_known = is_well_known_ref(name);
376 
377 	*ref = NULL;
378 
379 	if (ref_is_absolute || ref_is_well_known) {
380 		if (asprintf(&path, "%s/%s", path_refs, name) == -1)
381 			return got_error_from_errno("asprintf");
382 		absname = (char *)name;
383 	} else {
384 		if (asprintf(&path, "%s/%s%s%s", path_refs, subdir,
385 		    subdir[0] ? "/" : "", name) == -1)
386 			return got_error_from_errno("asprintf");
387 
388 		if (asprintf(&absname, "refs/%s%s%s",
389 		    subdir, subdir[0] ? "/" : "", name) == -1) {
390 			err = got_error_from_errno("asprintf");
391 			goto done;
392 		}
393 	}
394 
395 	normpath = got_path_normalize(path);
396 	if (normpath == NULL) {
397 		if (errno == ENOENT)
398 			err = NULL;
399 		else
400 			err = got_error_from_errno2("got_path_normalize", path);
401 		goto done;
402 	}
403 
404 	err = parse_ref_file(ref, absname, normpath, lock);
405 done:
406 	if (!ref_is_absolute && !ref_is_well_known)
407 		free(absname);
408 	free(path);
409 	free(normpath);
410 	return err;
411 }
412 
413 const struct got_error *
414 got_ref_open(struct got_reference **ref, struct got_repository *repo,
415    const char *refname, int lock)
416 {
417 	const struct got_error *err = NULL;
418 	char *path_refs = NULL;
419 	const char *subdirs[] = {
420 	    GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
421 	};
422 	int i, well_known = is_well_known_ref(refname);
423 	struct got_lockfile *lf = NULL;
424 
425 	*ref = NULL;
426 
427 	path_refs = get_refs_dir_path(repo, refname);
428 	if (path_refs == NULL) {
429 		err = got_error_from_errno2("get_refs_dir_path", refname);
430 		goto done;
431 	}
432 
433 	if (well_known) {
434 		err = open_ref(ref, path_refs, "", refname, lock);
435 	} else {
436 		char *packed_refs_path;
437 		FILE *f;
438 
439 		/* Search on-disk refs before packed refs! */
440 		for (i = 0; i < nitems(subdirs); i++) {
441 			err = open_ref(ref, path_refs, subdirs[i], refname,
442 			    lock);
443 			if (err || *ref)
444 				goto done;
445 		}
446 
447 		packed_refs_path = got_repo_get_path_packed_refs(repo);
448 		if (packed_refs_path == NULL) {
449 			err = got_error_from_errno(
450 			    "got_repo_get_path_packed_refs");
451 			goto done;
452 		}
453 
454 		if (lock) {
455 			err = got_lockfile_lock(&lf, packed_refs_path);
456 			if (err)
457 				goto done;
458 		}
459 		f = fopen(packed_refs_path, "rb");
460 		free(packed_refs_path);
461 		if (f != NULL) {
462 			err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
463 			    refname);
464 			if (!err) {
465 				if (fclose(f) != 0) {
466 					err = got_error_from_errno("fclose");
467 					got_ref_close(*ref);
468 					*ref = NULL;
469 				} else if (*ref)
470 					(*ref)->lf = lf;
471 			}
472 		}
473 	}
474 done:
475 	if (!err && *ref == NULL)
476 		err = got_error_not_ref(refname);
477 	if (err && lf)
478 		got_lockfile_unlock(lf);
479 	free(path_refs);
480 	return err;
481 }
482 
483 void
484 got_ref_close(struct got_reference *ref)
485 {
486 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
487 		free(ref->ref.symref.name);
488 		free(ref->ref.symref.ref);
489 	} else
490 		free(ref->ref.ref.name);
491 	free(ref);
492 }
493 
494 struct got_reference *
495 got_ref_dup(struct got_reference *ref)
496 {
497 	struct got_reference *ret;
498 
499 	ret = calloc(1, sizeof(*ret));
500 	if (ret == NULL)
501 		return NULL;
502 
503 	ret->flags = ref->flags;
504 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
505 		ret->ref.symref.name = strdup(ref->ref.symref.name);
506 		if (ret->ref.symref.name == NULL) {
507 			free(ret);
508 			return NULL;
509 		}
510 		ret->ref.symref.ref = strdup(ref->ref.symref.ref);
511 		if (ret->ref.symref.ref == NULL) {
512 			free(ret->ref.symref.name);
513 			free(ret);
514 			return NULL;
515 		}
516 	} else {
517 		ref->ref.ref.name = strdup(ref->ref.ref.name);
518 		if (ref->ref.ref.name == NULL) {
519 			free(ret);
520 			return NULL;
521 		}
522 		memcpy(ret->ref.ref.sha1, ref->ref.ref.sha1,
523 		    sizeof(ret->ref.ref.sha1));
524 	}
525 
526 	return ret;
527 }
528 
529 static const struct got_error *
530 resolve_symbolic_ref(struct got_reference **resolved,
531     struct got_repository *repo, struct got_reference *ref)
532 {
533 	struct got_reference *nextref;
534 	const struct got_error *err;
535 
536 	err = got_ref_open(&nextref, repo, ref->ref.symref.ref, 0);
537 	if (err)
538 		return err;
539 
540 	if (nextref->flags & GOT_REF_IS_SYMBOLIC)
541 		err = resolve_symbolic_ref(resolved, repo, nextref);
542 	else
543 		*resolved = got_ref_dup(nextref);
544 
545 	got_ref_close(nextref);
546 	return err;
547 }
548 
549 const struct got_error *
550 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
551     struct got_reference *ref)
552 {
553 	const struct got_error *err;
554 
555 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
556 		struct got_reference *resolved = NULL;
557 		err = resolve_symbolic_ref(&resolved, repo, ref);
558 		if (err == NULL)
559 			err = got_ref_resolve(id, repo, resolved);
560 		if (resolved)
561 			got_ref_close(resolved);
562 		return err;
563 	}
564 
565 	*id = calloc(1, sizeof(**id));
566 	if (*id == NULL)
567 		return got_error_from_errno("calloc");
568 	memcpy((*id)->sha1, ref->ref.ref.sha1, sizeof((*id)->sha1));
569 	return NULL;
570 }
571 
572 char *
573 got_ref_to_str(struct got_reference *ref)
574 {
575 	char *str;
576 
577 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
578 		return strdup(ref->ref.symref.ref);
579 
580 	str = malloc(SHA1_DIGEST_STRING_LENGTH);
581 	if (str == NULL)
582 		return NULL;
583 
584 	if (got_sha1_digest_to_str(ref->ref.ref.sha1, str,
585 	    SHA1_DIGEST_STRING_LENGTH) == NULL) {
586 		free(str);
587 		return NULL;
588 	}
589 
590 	return str;
591 }
592 
593 const char *
594 got_ref_get_name(struct got_reference *ref)
595 {
596 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
597 		return ref->ref.symref.name;
598 
599 	return ref->ref.ref.name;
600 }
601 
602 static const struct got_error *
603 insert_ref(struct got_reflist_entry **newp, struct got_reflist_head *refs,
604     struct got_reference *ref, struct got_repository *repo)
605 {
606 	const struct got_error *err;
607 	struct got_object_id *id;
608 	struct got_reflist_entry *new, *re, *prev = NULL;
609 	int cmp;
610 
611 	*newp = NULL;
612 
613 	err = got_ref_resolve(&id, repo, ref);
614 	if (err)
615 		return err;
616 
617 	new = malloc(sizeof(*new));
618 	if (new == NULL) {
619 		free(id);
620 		return got_error_from_errno("malloc");
621 	}
622 	new->ref = ref;
623 	new->id = id;
624 	*newp = new;
625 
626 	/*
627 	 * We must de-duplicate entries on insert because packed-refs may
628 	 * contain redundant entries. On-disk refs take precedence.
629 	 * This code assumes that on-disk revs are read before packed-refs.
630 	 * We're iterating the list anyway, so insert elements sorted by name.
631 	 */
632 	re = SIMPLEQ_FIRST(refs);
633 	while (re) {
634 		cmp = got_path_cmp(got_ref_get_name(re->ref),
635 		    got_ref_get_name(new->ref));
636 		if (cmp == 0) {
637 			/* duplicate */
638 			free(new->id);
639 			free(new);
640 			*newp = NULL;
641 			return NULL;
642 		} else if (cmp > 0) {
643 			if (prev)
644 				SIMPLEQ_INSERT_AFTER(refs, prev, new, entry);
645 			else
646 				SIMPLEQ_INSERT_HEAD(refs, new, entry);
647 			return NULL;
648 		} else {
649 			prev = re;
650 			re = SIMPLEQ_NEXT(re, entry);
651 		}
652 	}
653 
654 	SIMPLEQ_INSERT_TAIL(refs, new, entry);
655 	return NULL;
656 }
657 
658 static const struct got_error *
659 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
660     const char *subdir, struct got_repository *repo)
661 {
662 	const struct got_error *err = NULL;
663 	DIR *d = NULL;
664 	char *path_subdir;
665 
666 	if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
667 		return got_error_from_errno("asprintf");
668 
669 	d = opendir(path_subdir);
670 	if (d == NULL)
671 		goto done;
672 
673 	for (;;) {
674 		struct dirent *dent;
675 		struct got_reference *ref;
676 		char *child;
677 
678 		dent = readdir(d);
679 		if (dent == NULL)
680 			break;
681 
682 		if (strcmp(dent->d_name, ".") == 0 ||
683 		    strcmp(dent->d_name, "..") == 0)
684 			continue;
685 
686 		switch (dent->d_type) {
687 		case DT_REG:
688 			err = open_ref(&ref, path_refs, subdir, dent->d_name,
689 			    0);
690 			if (err)
691 				goto done;
692 			if (ref) {
693 				struct got_reflist_entry *new;
694 				err = insert_ref(&new, refs, ref, repo);
695 				if (err || new == NULL /* duplicate */)
696 					got_ref_close(ref);
697 				if (err)
698 					goto done;
699 			}
700 			break;
701 		case DT_DIR:
702 			if (asprintf(&child, "%s%s%s", subdir,
703 			    subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
704 				err = got_error_from_errno("asprintf");
705 				break;
706 			}
707 			err = gather_on_disk_refs(refs, path_refs, child, repo);
708 			free(child);
709 			break;
710 		default:
711 			break;
712 		}
713 	}
714 done:
715 	if (d)
716 		closedir(d);
717 	free(path_subdir);
718 	return err;
719 }
720 
721 const struct got_error *
722 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo)
723 {
724 	const struct got_error *err;
725 	char *packed_refs_path, *path_refs = NULL;
726 	FILE *f = NULL;
727 	struct got_reference *ref;
728 	struct got_reflist_entry *new;
729 
730 	/* HEAD ref should always exist. */
731 	path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
732 	if (path_refs == NULL) {
733 		err = got_error_from_errno("get_refs_dir_path");
734 		goto done;
735 	}
736 	err = open_ref(&ref, path_refs, "", GOT_REF_HEAD, 0);
737 	if (err)
738 		goto done;
739 	err = insert_ref(&new, refs, ref, repo);
740 	if (err || new == NULL /* duplicate */)
741 		got_ref_close(ref);
742 	if (err)
743 		goto done;
744 
745 	/* Gather on-disk refs before parsing packed-refs. */
746 	free(path_refs);
747 	path_refs = get_refs_dir_path(repo, "");
748 	if (path_refs == NULL) {
749 		err = got_error_from_errno("get_refs_dir_path");
750 		goto done;
751 	}
752 	err = gather_on_disk_refs(refs, path_refs, "", repo);
753 	if (err)
754 		goto done;
755 
756 	/*
757 	 * The packed-refs file may contain redundant entries, in which
758 	 * case on-disk refs take precedence.
759 	 */
760 	packed_refs_path = got_repo_get_path_packed_refs(repo);
761 	if (packed_refs_path == NULL) {
762 		err = got_error_from_errno("got_repo_get_path_packed_refs");
763 		goto done;
764 	}
765 
766 	f = fopen(packed_refs_path, "r");
767 	free(packed_refs_path);
768 	if (f) {
769 		char *line;
770 		size_t len;
771 		const char delim[3] = {'\0', '\0', '\0'};
772 		for (;;) {
773 			line = fparseln(f, &len, NULL, delim, 0);
774 			if (line == NULL) {
775 				if (feof(f))
776 					break;
777 				err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
778 				goto done;
779 			}
780 			err = parse_packed_ref_line(&ref, NULL, line);
781 			free(line);
782 			if (err)
783 				goto done;
784 			if (ref) {
785 				err = insert_ref(&new, refs, ref, repo);
786 				if (err || new == NULL /* duplicate */)
787 					got_ref_close(ref);
788 				if (err)
789 					goto done;
790 			}
791 		}
792 	}
793 done:
794 	free(path_refs);
795 	if (f && fclose(f) != 0 && err == NULL)
796 		err = got_error_from_errno("fclose");
797 	return err;
798 }
799 
800 void
801 got_ref_list_free(struct got_reflist_head *refs)
802 {
803 	struct got_reflist_entry *re;
804 
805 	while (!SIMPLEQ_EMPTY(refs)) {
806 		re = SIMPLEQ_FIRST(refs);
807 		SIMPLEQ_REMOVE_HEAD(refs, entry);
808 		got_ref_close(re->ref);
809 		free(re->id);
810 		free(re);
811 	}
812 
813 }
814 
815 int
816 got_ref_is_symbolic(struct got_reference *ref)
817 {
818 	return (ref->flags & GOT_REF_IS_SYMBOLIC);
819 }
820 
821 const struct got_error *
822 got_ref_change_ref(struct got_reference *ref, struct got_object_id *id)
823 {
824 	if (ref->flags & GOT_REF_IS_SYMBOLIC)
825 		return got_error(GOT_ERR_BAD_REF_TYPE);
826 
827 	memcpy(ref->ref.ref.sha1, id->sha1, sizeof(ref->ref.ref.sha1));
828 	return NULL;
829 }
830 
831 const struct got_error *
832 got_ref_change_symref(struct got_reference *ref, char *refname)
833 {
834 	char *new_name;
835 
836 	if ((ref->flags & GOT_REF_IS_SYMBOLIC) == 0)
837 		return got_error(GOT_ERR_BAD_REF_TYPE);
838 
839 	new_name = strdup(refname);
840 	if (new_name == NULL)
841 		return got_error_from_errno("strdup");
842 
843 	free(ref->ref.symref.name);
844 	ref->ref.symref.name = new_name;
845 	return NULL;
846 }
847 
848 const struct got_error *
849 got_ref_write(struct got_reference *ref, struct got_repository *repo)
850 {
851 	const struct got_error *err = NULL, *unlock_err = NULL;
852 	const char *name = got_ref_get_name(ref);
853 	char *path_refs = NULL, *path = NULL, *tmppath = NULL;
854 	struct got_lockfile *lf = NULL;
855 	FILE *f = NULL;
856 	size_t n;
857 	struct stat sb;
858 
859 	path_refs = get_refs_dir_path(repo, name);
860 	if (path_refs == NULL) {
861 		err = got_error_from_errno2("get_refs_dir_path", name);
862 		goto done;
863 	}
864 
865 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
866 		err = got_error_from_errno("asprintf");
867 		goto done;
868 	}
869 
870 	err = got_opentemp_named(&tmppath, &f, path);
871 	if (err) {
872 		char *parent;
873 		if (!(err->code == GOT_ERR_ERRNO && errno == ENOENT))
874 			goto done;
875 		err = got_path_dirname(&parent, path);
876 		if (err)
877 			goto done;
878 		err = got_path_mkdir(parent);
879 		free(parent);
880 		if (err)
881 			goto done;
882 		err = got_opentemp_named(&tmppath, &f, path);
883 		if (err)
884 			goto done;
885 	}
886 
887 	if (ref->flags & GOT_REF_IS_SYMBOLIC) {
888 		n = fprintf(f, "ref: %s\n", ref->ref.symref.ref);
889 		if (n != strlen(ref->ref.symref.ref) + 6) {
890 			err = got_ferror(f, GOT_ERR_IO);
891 			goto done;
892 		}
893 	} else {
894 		char hex[SHA1_DIGEST_STRING_LENGTH];
895 		if (got_sha1_digest_to_str(ref->ref.ref.sha1, hex,
896 		    sizeof(hex)) == NULL) {
897 			err = got_error(GOT_ERR_BAD_REF_DATA);
898 			goto done;
899 		}
900 		n = fprintf(f, "%s\n", hex);
901 		if (n != sizeof(hex)) {
902 			err = got_ferror(f, GOT_ERR_IO);
903 			goto done;
904 		}
905 	}
906 
907 	if (ref->lf == NULL) {
908 		err = got_lockfile_lock(&lf, path);
909 		if (err)
910 			goto done;
911 	}
912 
913 	/* XXX: check if old content matches our expectations? */
914 
915 	if (stat(path, &sb) != 0) {
916 		if (errno != ENOENT) {
917 			err = got_error_from_errno2("stat", path);
918 			goto done;
919 		}
920 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
921 	}
922 
923 	if (rename(tmppath, path) != 0) {
924 		err = got_error_from_errno3("rename", tmppath, path);
925 		goto done;
926 	}
927 	free(tmppath);
928 	tmppath = NULL;
929 
930 	if (chmod(path, sb.st_mode) != 0) {
931 		err = got_error_from_errno2("chmod", path);
932 		goto done;
933 	}
934 done:
935 	if (ref->lf == NULL && lf)
936 		unlock_err = got_lockfile_unlock(lf);
937 	if (f) {
938 		if (fclose(f) != 0 && err == NULL)
939 			err = got_error_from_errno("fclose");
940 	}
941 	free(path_refs);
942 	free(path);
943 	if (tmppath) {
944 		if (unlink(tmppath) != 0 && err == NULL)
945 			err = got_error_from_errno2("unlink", tmppath);
946 		free(tmppath);
947 	}
948 	return err ? err : unlock_err;
949 }
950 
951 static const struct got_error *
952 delete_packed_ref(struct got_reference *delref, struct got_repository *repo)
953 {
954 	const struct got_error *err = NULL, *unlock_err = NULL;
955 	struct got_lockfile *lf = NULL;
956 	FILE *f = NULL, *tmpf = NULL;
957 	char *packed_refs_path, *tmppath = NULL;
958 	struct got_reflist_head refs;
959 	int found_delref = 0;
960 
961 	/* The packed-refs file does not cotain symbolic references. */
962 	if (delref->flags & GOT_REF_IS_SYMBOLIC)
963 		return got_error(GOT_ERR_BAD_REF_DATA);
964 
965 	SIMPLEQ_INIT(&refs);
966 
967 	packed_refs_path = got_repo_get_path_packed_refs(repo);
968 	if (packed_refs_path == NULL)
969 		return got_error_from_errno("got_repo_get_path_packed_refs");
970 
971 	err = got_opentemp_named(&tmppath, &tmpf, packed_refs_path);
972 	if (err)
973 		goto done;
974 
975 	if (delref->lf == NULL) {
976 		err = got_lockfile_lock(&lf, packed_refs_path);
977 		if (err)
978 			goto done;
979 	}
980 
981 	f = fopen(packed_refs_path, "r");
982 	if (f == NULL) {
983 		err = got_error_from_errno2("fopen", packed_refs_path);
984 		goto done;
985 	}
986 	for (;;) {
987 		char *line;
988 		size_t len;
989 		const char delim[3] = {'\0', '\0', '\0'};
990 		struct got_reference *ref;
991 		struct got_reflist_entry *new;
992 
993 		line = fparseln(f, &len, NULL, delim, 0);
994 		if (line == NULL) {
995 			if (feof(f))
996 				break;
997 			err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
998 			goto done;
999 		}
1000 		err = parse_packed_ref_line(&ref, NULL, line);
1001 		free(line);
1002 		if (err)
1003 			goto done;
1004 		if (ref == NULL)
1005 			continue;
1006 
1007 		if (strcmp(ref->ref.ref.name, delref->ref.ref.name) == 0 &&
1008 		    memcmp(ref->ref.ref.sha1, delref->ref.ref.sha1,
1009 		    sizeof(delref->ref.ref.sha1)) == 0) {
1010 			found_delref = 1;
1011 			got_ref_close(ref);
1012 			continue;
1013 		}
1014 
1015 		err = insert_ref(&new, &refs, ref, repo);
1016 		if (err || new == NULL /* duplicate */)
1017 			got_ref_close(ref);
1018 		if (err)
1019 			goto done;
1020 	}
1021 
1022 	if (found_delref) {
1023 		struct got_reflist_entry *re;
1024 		size_t n;
1025 		struct stat sb;
1026 
1027 		n = fprintf(tmpf, "%s\n", GOT_PACKED_REFS_HEADER);
1028 		if (n != sizeof(GOT_PACKED_REFS_HEADER)) {
1029 			err = got_ferror(f, GOT_ERR_IO);
1030 			goto done;
1031 		}
1032 
1033 		SIMPLEQ_FOREACH(re, &refs, entry) {
1034 			uint8_t hex[SHA1_DIGEST_STRING_LENGTH];
1035 
1036 			if (got_sha1_digest_to_str(re->ref->ref.ref.sha1, hex,
1037 			    sizeof(hex)) == NULL) {
1038 				err = got_error(GOT_ERR_BAD_REF_DATA);
1039 				goto done;
1040 			}
1041 			n = fprintf(tmpf, "%s ", hex);
1042 			if (n != sizeof(hex)) {
1043 				err = got_ferror(f, GOT_ERR_IO);
1044 				goto done;
1045 			}
1046 			n = fprintf(tmpf, "%s\n", re->ref->ref.ref.name);
1047 			if (n != strlen(re->ref->ref.ref.name) + 1) {
1048 				err = got_ferror(f, GOT_ERR_IO);
1049 				goto done;
1050 			}
1051 		}
1052 
1053 		if (fflush(tmpf) != 0) {
1054 			err = got_error_from_errno("fflush");
1055 			goto done;
1056 		}
1057 
1058 		if (stat(packed_refs_path, &sb) != 0) {
1059 			if (errno != ENOENT) {
1060 				err = got_error_from_errno2("stat",
1061 				    packed_refs_path);
1062 				goto done;
1063 			}
1064 			sb.st_mode = GOT_DEFAULT_FILE_MODE;
1065 		}
1066 
1067 		if (rename(tmppath, packed_refs_path) != 0) {
1068 			err = got_error_from_errno3("rename", tmppath,
1069 			    packed_refs_path);
1070 			goto done;
1071 		}
1072 
1073 		if (chmod(packed_refs_path, sb.st_mode) != 0) {
1074 			err = got_error_from_errno2("chmod",
1075 			    packed_refs_path);
1076 			goto done;
1077 		}
1078 	}
1079 done:
1080 	if (delref->lf == NULL && lf)
1081 		unlock_err = got_lockfile_unlock(lf);
1082 	if (f) {
1083 		if (fclose(f) != 0 && err == NULL)
1084 			err = got_error_from_errno("fclose");
1085 	}
1086 	if (tmpf) {
1087 		unlink(tmppath);
1088 		if (fclose(tmpf) != 0 && err == NULL)
1089 			err = got_error_from_errno("fclose");
1090 	}
1091 	free(tmppath);
1092 	free(packed_refs_path);
1093 	got_ref_list_free(&refs);
1094 	return err ? err : unlock_err;
1095 }
1096 
1097 const struct got_error *
1098 got_ref_delete(struct got_reference *ref, struct got_repository *repo)
1099 {
1100 	const struct got_error *err = NULL, *unlock_err = NULL;
1101 	const char *name = got_ref_get_name(ref);
1102 	char *path_refs = NULL, *path = NULL;
1103 	struct got_lockfile *lf = NULL;
1104 
1105 	if (ref->flags & GOT_REF_IS_PACKED)
1106 		return delete_packed_ref(ref, repo);
1107 
1108 	path_refs = get_refs_dir_path(repo, name);
1109 	if (path_refs == NULL) {
1110 		err = got_error_from_errno2("get_refs_dir_path", name);
1111 		goto done;
1112 	}
1113 
1114 	if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1115 		err = got_error_from_errno("asprintf");
1116 		goto done;
1117 	}
1118 
1119 	if (ref->lf == NULL) {
1120 		err = got_lockfile_lock(&lf, path);
1121 		if (err)
1122 			goto done;
1123 	}
1124 
1125 	/* XXX: check if old content matches our expectations? */
1126 
1127 	if (unlink(path) != 0)
1128 		err = got_error_from_errno2("unlink", path);
1129 done:
1130 	if (ref->lf == NULL && lf)
1131 		unlock_err = got_lockfile_unlock(lf);
1132 
1133 	free(path_refs);
1134 	free(path);
1135 	return err ? err : unlock_err;
1136 }
1137 
1138 const struct got_error *
1139 got_ref_unlock(struct got_reference *ref)
1140 {
1141 	const struct got_error *err;
1142 	err = got_lockfile_unlock(ref->lf);
1143 	ref->lf = NULL;
1144 	return err;
1145 }