pack-objects test: modernize style
[git] / refs.c
1 /*
2  * The backend-independent part of the reference module.
3  */
4
5 #include "cache.h"
6 #include "config.h"
7 #include "hashmap.h"
8 #include "lockfile.h"
9 #include "iterator.h"
10 #include "refs.h"
11 #include "refs/refs-internal.h"
12 #include "object-store.h"
13 #include "object.h"
14 #include "tag.h"
15 #include "submodule.h"
16 #include "worktree.h"
17 #include "argv-array.h"
18 #include "repository.h"
19
20 /*
21  * List of all available backends
22  */
23 static struct ref_storage_be *refs_backends = &refs_be_files;
24
25 static struct ref_storage_be *find_ref_storage_backend(const char *name)
26 {
27         struct ref_storage_be *be;
28         for (be = refs_backends; be; be = be->next)
29                 if (!strcmp(be->name, name))
30                         return be;
31         return NULL;
32 }
33
34 int ref_storage_backend_exists(const char *name)
35 {
36         return find_ref_storage_backend(name) != NULL;
37 }
38
39 /*
40  * How to handle various characters in refnames:
41  * 0: An acceptable character for refs
42  * 1: End-of-component
43  * 2: ., look for a preceding . to reject .. in refs
44  * 3: {, look for a preceding @ to reject @{ in refs
45  * 4: A bad character: ASCII control characters, and
46  *    ":", "?", "[", "\", "^", "~", SP, or TAB
47  * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
48  */
49 static unsigned char refname_disposition[256] = {
50         1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
51         4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
52         4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
53         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
54         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
55         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
56         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
57         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
58 };
59
60 /*
61  * Try to read one refname component from the front of refname.
62  * Return the length of the component found, or -1 if the component is
63  * not legal.  It is legal if it is something reasonable to have under
64  * ".git/refs/"; We do not like it if:
65  *
66  * - any path component of it begins with ".", or
67  * - it has double dots "..", or
68  * - it has ASCII control characters, or
69  * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
70  * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
71  * - it ends with a "/", or
72  * - it ends with ".lock", or
73  * - it contains a "@{" portion
74  */
75 static int check_refname_component(const char *refname, int *flags)
76 {
77         const char *cp;
78         char last = '\0';
79
80         for (cp = refname; ; cp++) {
81                 int ch = *cp & 255;
82                 unsigned char disp = refname_disposition[ch];
83                 switch (disp) {
84                 case 1:
85                         goto out;
86                 case 2:
87                         if (last == '.')
88                                 return -1; /* Refname contains "..". */
89                         break;
90                 case 3:
91                         if (last == '@')
92                                 return -1; /* Refname contains "@{". */
93                         break;
94                 case 4:
95                         return -1;
96                 case 5:
97                         if (!(*flags & REFNAME_REFSPEC_PATTERN))
98                                 return -1; /* refspec can't be a pattern */
99
100                         /*
101                          * Unset the pattern flag so that we only accept
102                          * a single asterisk for one side of refspec.
103                          */
104                         *flags &= ~ REFNAME_REFSPEC_PATTERN;
105                         break;
106                 }
107                 last = ch;
108         }
109 out:
110         if (cp == refname)
111                 return 0; /* Component has zero length. */
112         if (refname[0] == '.')
113                 return -1; /* Component starts with '.'. */
114         if (cp - refname >= LOCK_SUFFIX_LEN &&
115             !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
116                 return -1; /* Refname ends with ".lock". */
117         return cp - refname;
118 }
119
120 int check_refname_format(const char *refname, int flags)
121 {
122         int component_len, component_count = 0;
123
124         if (!strcmp(refname, "@"))
125                 /* Refname is a single character '@'. */
126                 return -1;
127
128         while (1) {
129                 /* We are at the start of a path component. */
130                 component_len = check_refname_component(refname, &flags);
131                 if (component_len <= 0)
132                         return -1;
133
134                 component_count++;
135                 if (refname[component_len] == '\0')
136                         break;
137                 /* Skip to next component. */
138                 refname += component_len + 1;
139         }
140
141         if (refname[component_len - 1] == '.')
142                 return -1; /* Refname ends with '.'. */
143         if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
144                 return -1; /* Refname has only one component. */
145         return 0;
146 }
147
148 int refname_is_safe(const char *refname)
149 {
150         const char *rest;
151
152         if (skip_prefix(refname, "refs/", &rest)) {
153                 char *buf;
154                 int result;
155                 size_t restlen = strlen(rest);
156
157                 /* rest must not be empty, or start or end with "/" */
158                 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
159                         return 0;
160
161                 /*
162                  * Does the refname try to escape refs/?
163                  * For example: refs/foo/../bar is safe but refs/foo/../../bar
164                  * is not.
165                  */
166                 buf = xmallocz(restlen);
167                 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
168                 free(buf);
169                 return result;
170         }
171
172         do {
173                 if (!isupper(*refname) && *refname != '_')
174                         return 0;
175                 refname++;
176         } while (*refname);
177         return 1;
178 }
179
180 /*
181  * Return true if refname, which has the specified oid and flags, can
182  * be resolved to an object in the database. If the referred-to object
183  * does not exist, emit a warning and return false.
184  */
185 int ref_resolves_to_object(const char *refname,
186                            const struct object_id *oid,
187                            unsigned int flags)
188 {
189         if (flags & REF_ISBROKEN)
190                 return 0;
191         if (!has_sha1_file(oid->hash)) {
192                 error(_("%s does not point to a valid object!"), refname);
193                 return 0;
194         }
195         return 1;
196 }
197
198 char *refs_resolve_refdup(struct ref_store *refs,
199                           const char *refname, int resolve_flags,
200                           struct object_id *oid, int *flags)
201 {
202         const char *result;
203
204         result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
205                                          oid, flags);
206         return xstrdup_or_null(result);
207 }
208
209 char *resolve_refdup(const char *refname, int resolve_flags,
210                      struct object_id *oid, int *flags)
211 {
212         return refs_resolve_refdup(get_main_ref_store(the_repository),
213                                    refname, resolve_flags,
214                                    oid, flags);
215 }
216
217 /* The argument to filter_refs */
218 struct ref_filter {
219         const char *pattern;
220         each_ref_fn *fn;
221         void *cb_data;
222 };
223
224 int refs_read_ref_full(struct ref_store *refs, const char *refname,
225                        int resolve_flags, struct object_id *oid, int *flags)
226 {
227         if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, oid, flags))
228                 return 0;
229         return -1;
230 }
231
232 int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
233 {
234         return refs_read_ref_full(get_main_ref_store(the_repository), refname,
235                                   resolve_flags, oid, flags);
236 }
237
238 int read_ref(const char *refname, struct object_id *oid)
239 {
240         return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
241 }
242
243 int ref_exists(const char *refname)
244 {
245         return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, NULL, NULL);
246 }
247
248 static int match_ref_pattern(const char *refname,
249                              const struct string_list_item *item)
250 {
251         int matched = 0;
252         if (item->util == NULL) {
253                 if (!wildmatch(item->string, refname, 0))
254                         matched = 1;
255         } else {
256                 const char *rest;
257                 if (skip_prefix(refname, item->string, &rest) &&
258                     (!*rest || *rest == '/'))
259                         matched = 1;
260         }
261         return matched;
262 }
263
264 int ref_filter_match(const char *refname,
265                      const struct string_list *include_patterns,
266                      const struct string_list *exclude_patterns)
267 {
268         struct string_list_item *item;
269
270         if (exclude_patterns && exclude_patterns->nr) {
271                 for_each_string_list_item(item, exclude_patterns) {
272                         if (match_ref_pattern(refname, item))
273                                 return 0;
274                 }
275         }
276
277         if (include_patterns && include_patterns->nr) {
278                 int found = 0;
279                 for_each_string_list_item(item, include_patterns) {
280                         if (match_ref_pattern(refname, item)) {
281                                 found = 1;
282                                 break;
283                         }
284                 }
285
286                 if (!found)
287                         return 0;
288         }
289         return 1;
290 }
291
292 static int filter_refs(const char *refname, const struct object_id *oid,
293                            int flags, void *data)
294 {
295         struct ref_filter *filter = (struct ref_filter *)data;
296
297         if (wildmatch(filter->pattern, refname, 0))
298                 return 0;
299         return filter->fn(refname, oid, flags, filter->cb_data);
300 }
301
302 enum peel_status peel_object(const struct object_id *name, struct object_id *oid)
303 {
304         struct object *o = lookup_unknown_object(name->hash);
305
306         if (o->type == OBJ_NONE) {
307                 int type = oid_object_info(the_repository, name, NULL);
308                 if (type < 0 || !object_as_type(the_repository, o, type, 0))
309                         return PEEL_INVALID;
310         }
311
312         if (o->type != OBJ_TAG)
313                 return PEEL_NON_TAG;
314
315         o = deref_tag_noverify(o);
316         if (!o)
317                 return PEEL_INVALID;
318
319         oidcpy(oid, &o->oid);
320         return PEEL_PEELED;
321 }
322
323 struct warn_if_dangling_data {
324         FILE *fp;
325         const char *refname;
326         const struct string_list *refnames;
327         const char *msg_fmt;
328 };
329
330 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
331                                    int flags, void *cb_data)
332 {
333         struct warn_if_dangling_data *d = cb_data;
334         const char *resolves_to;
335
336         if (!(flags & REF_ISSYMREF))
337                 return 0;
338
339         resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
340         if (!resolves_to
341             || (d->refname
342                 ? strcmp(resolves_to, d->refname)
343                 : !string_list_has_string(d->refnames, resolves_to))) {
344                 return 0;
345         }
346
347         fprintf(d->fp, d->msg_fmt, refname);
348         fputc('\n', d->fp);
349         return 0;
350 }
351
352 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
353 {
354         struct warn_if_dangling_data data;
355
356         data.fp = fp;
357         data.refname = refname;
358         data.refnames = NULL;
359         data.msg_fmt = msg_fmt;
360         for_each_rawref(warn_if_dangling_symref, &data);
361 }
362
363 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
364 {
365         struct warn_if_dangling_data data;
366
367         data.fp = fp;
368         data.refname = NULL;
369         data.refnames = refnames;
370         data.msg_fmt = msg_fmt;
371         for_each_rawref(warn_if_dangling_symref, &data);
372 }
373
374 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
375 {
376         return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
377 }
378
379 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
380 {
381         return refs_for_each_tag_ref(get_main_ref_store(the_repository), fn, cb_data);
382 }
383
384 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
385 {
386         return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
387 }
388
389 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
390 {
391         return refs_for_each_branch_ref(get_main_ref_store(the_repository), fn, cb_data);
392 }
393
394 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
395 {
396         return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
397 }
398
399 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
400 {
401         return refs_for_each_remote_ref(get_main_ref_store(the_repository), fn, cb_data);
402 }
403
404 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
405 {
406         struct strbuf buf = STRBUF_INIT;
407         int ret = 0;
408         struct object_id oid;
409         int flag;
410
411         strbuf_addf(&buf, "%sHEAD", get_git_namespace());
412         if (!read_ref_full(buf.buf, RESOLVE_REF_READING, &oid, &flag))
413                 ret = fn(buf.buf, &oid, flag, cb_data);
414         strbuf_release(&buf);
415
416         return ret;
417 }
418
419 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
420                         const char *pattern)
421 {
422         struct strbuf normalized_pattern = STRBUF_INIT;
423
424         if (*pattern == '/')
425                 BUG("pattern must not start with '/'");
426
427         if (prefix) {
428                 strbuf_addstr(&normalized_pattern, prefix);
429         }
430         else if (!starts_with(pattern, "refs/"))
431                 strbuf_addstr(&normalized_pattern, "refs/");
432         strbuf_addstr(&normalized_pattern, pattern);
433         strbuf_strip_suffix(&normalized_pattern, "/");
434
435         item->string = strbuf_detach(&normalized_pattern, NULL);
436         item->util = has_glob_specials(pattern) ? NULL : item->string;
437         strbuf_release(&normalized_pattern);
438 }
439
440 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
441         const char *prefix, void *cb_data)
442 {
443         struct strbuf real_pattern = STRBUF_INIT;
444         struct ref_filter filter;
445         int ret;
446
447         if (!prefix && !starts_with(pattern, "refs/"))
448                 strbuf_addstr(&real_pattern, "refs/");
449         else if (prefix)
450                 strbuf_addstr(&real_pattern, prefix);
451         strbuf_addstr(&real_pattern, pattern);
452
453         if (!has_glob_specials(pattern)) {
454                 /* Append implied '/' '*' if not present. */
455                 strbuf_complete(&real_pattern, '/');
456                 /* No need to check for '*', there is none. */
457                 strbuf_addch(&real_pattern, '*');
458         }
459
460         filter.pattern = real_pattern.buf;
461         filter.fn = fn;
462         filter.cb_data = cb_data;
463         ret = for_each_ref(filter_refs, &filter);
464
465         strbuf_release(&real_pattern);
466         return ret;
467 }
468
469 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
470 {
471         return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
472 }
473
474 const char *prettify_refname(const char *name)
475 {
476         if (skip_prefix(name, "refs/heads/", &name) ||
477             skip_prefix(name, "refs/tags/", &name) ||
478             skip_prefix(name, "refs/remotes/", &name))
479                 ; /* nothing */
480         return name;
481 }
482
483 static const char *ref_rev_parse_rules[] = {
484         "%.*s",
485         "refs/%.*s",
486         "refs/tags/%.*s",
487         "refs/heads/%.*s",
488         "refs/remotes/%.*s",
489         "refs/remotes/%.*s/HEAD",
490         NULL
491 };
492
493 #define NUM_REV_PARSE_RULES (ARRAY_SIZE(ref_rev_parse_rules) - 1)
494
495 /*
496  * Is it possible that the caller meant full_name with abbrev_name?
497  * If so return a non-zero value to signal "yes"; the magnitude of
498  * the returned value gives the precedence used for disambiguation.
499  *
500  * If abbrev_name cannot mean full_name, return 0.
501  */
502 int refname_match(const char *abbrev_name, const char *full_name)
503 {
504         const char **p;
505         const int abbrev_name_len = strlen(abbrev_name);
506         const int num_rules = NUM_REV_PARSE_RULES;
507
508         for (p = ref_rev_parse_rules; *p; p++)
509                 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name)))
510                         return &ref_rev_parse_rules[num_rules] - p;
511
512         return 0;
513 }
514
515 /*
516  * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
517  * the results to 'prefixes'
518  */
519 void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
520 {
521         const char **p;
522         int len = strlen(prefix);
523
524         for (p = ref_rev_parse_rules; *p; p++)
525                 argv_array_pushf(prefixes, *p, len, prefix);
526 }
527
528 /*
529  * *string and *len will only be substituted, and *string returned (for
530  * later free()ing) if the string passed in is a magic short-hand form
531  * to name a branch.
532  */
533 static char *substitute_branch_name(const char **string, int *len)
534 {
535         struct strbuf buf = STRBUF_INIT;
536         int ret = interpret_branch_name(*string, *len, &buf, 0);
537
538         if (ret == *len) {
539                 size_t size;
540                 *string = strbuf_detach(&buf, &size);
541                 *len = size;
542                 return (char *)*string;
543         }
544
545         return NULL;
546 }
547
548 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref)
549 {
550         char *last_branch = substitute_branch_name(&str, &len);
551         int   refs_found  = expand_ref(str, len, oid, ref);
552         free(last_branch);
553         return refs_found;
554 }
555
556 int expand_ref(const char *str, int len, struct object_id *oid, char **ref)
557 {
558         const char **p, *r;
559         int refs_found = 0;
560         struct strbuf fullref = STRBUF_INIT;
561
562         *ref = NULL;
563         for (p = ref_rev_parse_rules; *p; p++) {
564                 struct object_id oid_from_ref;
565                 struct object_id *this_result;
566                 int flag;
567
568                 this_result = refs_found ? &oid_from_ref : oid;
569                 strbuf_reset(&fullref);
570                 strbuf_addf(&fullref, *p, len, str);
571                 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
572                                        this_result, &flag);
573                 if (r) {
574                         if (!refs_found++)
575                                 *ref = xstrdup(r);
576                         if (!warn_ambiguous_refs)
577                                 break;
578                 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
579                         warning(_("ignoring dangling symref %s"), fullref.buf);
580                 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
581                         warning(_("ignoring broken ref %s"), fullref.buf);
582                 }
583         }
584         strbuf_release(&fullref);
585         return refs_found;
586 }
587
588 int dwim_log(const char *str, int len, struct object_id *oid, char **log)
589 {
590         char *last_branch = substitute_branch_name(&str, &len);
591         const char **p;
592         int logs_found = 0;
593         struct strbuf path = STRBUF_INIT;
594
595         *log = NULL;
596         for (p = ref_rev_parse_rules; *p; p++) {
597                 struct object_id hash;
598                 const char *ref, *it;
599
600                 strbuf_reset(&path);
601                 strbuf_addf(&path, *p, len, str);
602                 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
603                                          &hash, NULL);
604                 if (!ref)
605                         continue;
606                 if (reflog_exists(path.buf))
607                         it = path.buf;
608                 else if (strcmp(ref, path.buf) && reflog_exists(ref))
609                         it = ref;
610                 else
611                         continue;
612                 if (!logs_found++) {
613                         *log = xstrdup(it);
614                         oidcpy(oid, &hash);
615                 }
616                 if (!warn_ambiguous_refs)
617                         break;
618         }
619         strbuf_release(&path);
620         free(last_branch);
621         return logs_found;
622 }
623
624 static int is_per_worktree_ref(const char *refname)
625 {
626         return !strcmp(refname, "HEAD") ||
627                 starts_with(refname, "refs/bisect/") ||
628                 starts_with(refname, "refs/rewritten/");
629 }
630
631 static int is_pseudoref_syntax(const char *refname)
632 {
633         const char *c;
634
635         for (c = refname; *c; c++) {
636                 if (!isupper(*c) && *c != '-' && *c != '_')
637                         return 0;
638         }
639
640         return 1;
641 }
642
643 enum ref_type ref_type(const char *refname)
644 {
645         if (is_per_worktree_ref(refname))
646                 return REF_TYPE_PER_WORKTREE;
647         if (is_pseudoref_syntax(refname))
648                 return REF_TYPE_PSEUDOREF;
649        return REF_TYPE_NORMAL;
650 }
651
652 long get_files_ref_lock_timeout_ms(void)
653 {
654         static int configured = 0;
655
656         /* The default timeout is 100 ms: */
657         static int timeout_ms = 100;
658
659         if (!configured) {
660                 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
661                 configured = 1;
662         }
663
664         return timeout_ms;
665 }
666
667 static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
668                            const struct object_id *old_oid, struct strbuf *err)
669 {
670         const char *filename;
671         int fd;
672         struct lock_file lock = LOCK_INIT;
673         struct strbuf buf = STRBUF_INIT;
674         int ret = -1;
675
676         if (!oid)
677                 return 0;
678
679         strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
680
681         filename = git_path("%s", pseudoref);
682         fd = hold_lock_file_for_update_timeout(&lock, filename, 0,
683                                                get_files_ref_lock_timeout_ms());
684         if (fd < 0) {
685                 strbuf_addf(err, _("could not open '%s' for writing: %s"),
686                             filename, strerror(errno));
687                 goto done;
688         }
689
690         if (old_oid) {
691                 struct object_id actual_old_oid;
692
693                 if (read_ref(pseudoref, &actual_old_oid)) {
694                         if (!is_null_oid(old_oid)) {
695                                 strbuf_addf(err, _("could not read ref '%s'"),
696                                             pseudoref);
697                                 rollback_lock_file(&lock);
698                                 goto done;
699                         }
700                 } else if (is_null_oid(old_oid)) {
701                         strbuf_addf(err, _("ref '%s' already exists"),
702                                     pseudoref);
703                         rollback_lock_file(&lock);
704                         goto done;
705                 } else if (oidcmp(&actual_old_oid, old_oid)) {
706                         strbuf_addf(err, _("unexpected object ID when writing '%s'"),
707                                     pseudoref);
708                         rollback_lock_file(&lock);
709                         goto done;
710                 }
711         }
712
713         if (write_in_full(fd, buf.buf, buf.len) < 0) {
714                 strbuf_addf(err, _("could not write to '%s'"), filename);
715                 rollback_lock_file(&lock);
716                 goto done;
717         }
718
719         commit_lock_file(&lock);
720         ret = 0;
721 done:
722         strbuf_release(&buf);
723         return ret;
724 }
725
726 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
727 {
728         const char *filename;
729
730         filename = git_path("%s", pseudoref);
731
732         if (old_oid && !is_null_oid(old_oid)) {
733                 struct lock_file lock = LOCK_INIT;
734                 int fd;
735                 struct object_id actual_old_oid;
736
737                 fd = hold_lock_file_for_update_timeout(
738                                 &lock, filename, 0,
739                                 get_files_ref_lock_timeout_ms());
740                 if (fd < 0) {
741                         error_errno(_("could not open '%s' for writing"),
742                                     filename);
743                         return -1;
744                 }
745                 if (read_ref(pseudoref, &actual_old_oid))
746                         die(_("could not read ref '%s'"), pseudoref);
747                 if (oidcmp(&actual_old_oid, old_oid)) {
748                         error(_("unexpected object ID when deleting '%s'"),
749                               pseudoref);
750                         rollback_lock_file(&lock);
751                         return -1;
752                 }
753
754                 unlink(filename);
755                 rollback_lock_file(&lock);
756         } else {
757                 unlink(filename);
758         }
759
760         return 0;
761 }
762
763 int refs_delete_ref(struct ref_store *refs, const char *msg,
764                     const char *refname,
765                     const struct object_id *old_oid,
766                     unsigned int flags)
767 {
768         struct ref_transaction *transaction;
769         struct strbuf err = STRBUF_INIT;
770
771         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
772                 assert(refs == get_main_ref_store(the_repository));
773                 return delete_pseudoref(refname, old_oid);
774         }
775
776         transaction = ref_store_transaction_begin(refs, &err);
777         if (!transaction ||
778             ref_transaction_delete(transaction, refname, old_oid,
779                                    flags, msg, &err) ||
780             ref_transaction_commit(transaction, &err)) {
781                 error("%s", err.buf);
782                 ref_transaction_free(transaction);
783                 strbuf_release(&err);
784                 return 1;
785         }
786         ref_transaction_free(transaction);
787         strbuf_release(&err);
788         return 0;
789 }
790
791 int delete_ref(const char *msg, const char *refname,
792                const struct object_id *old_oid, unsigned int flags)
793 {
794         return refs_delete_ref(get_main_ref_store(the_repository), msg, refname,
795                                old_oid, flags);
796 }
797
798 void copy_reflog_msg(struct strbuf *sb, const char *msg)
799 {
800         char c;
801         int wasspace = 1;
802
803         strbuf_addch(sb, '\t');
804         while ((c = *msg++)) {
805                 if (wasspace && isspace(c))
806                         continue;
807                 wasspace = isspace(c);
808                 if (wasspace)
809                         c = ' ';
810                 strbuf_addch(sb, c);
811         }
812         strbuf_rtrim(sb);
813 }
814
815 int should_autocreate_reflog(const char *refname)
816 {
817         switch (log_all_ref_updates) {
818         case LOG_REFS_ALWAYS:
819                 return 1;
820         case LOG_REFS_NORMAL:
821                 return starts_with(refname, "refs/heads/") ||
822                         starts_with(refname, "refs/remotes/") ||
823                         starts_with(refname, "refs/notes/") ||
824                         !strcmp(refname, "HEAD");
825         default:
826                 return 0;
827         }
828 }
829
830 int is_branch(const char *refname)
831 {
832         return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
833 }
834
835 struct read_ref_at_cb {
836         const char *refname;
837         timestamp_t at_time;
838         int cnt;
839         int reccnt;
840         struct object_id *oid;
841         int found_it;
842
843         struct object_id ooid;
844         struct object_id noid;
845         int tz;
846         timestamp_t date;
847         char **msg;
848         timestamp_t *cutoff_time;
849         int *cutoff_tz;
850         int *cutoff_cnt;
851 };
852
853 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
854                 const char *email, timestamp_t timestamp, int tz,
855                 const char *message, void *cb_data)
856 {
857         struct read_ref_at_cb *cb = cb_data;
858
859         cb->reccnt++;
860         cb->tz = tz;
861         cb->date = timestamp;
862
863         if (timestamp <= cb->at_time || cb->cnt == 0) {
864                 if (cb->msg)
865                         *cb->msg = xstrdup(message);
866                 if (cb->cutoff_time)
867                         *cb->cutoff_time = timestamp;
868                 if (cb->cutoff_tz)
869                         *cb->cutoff_tz = tz;
870                 if (cb->cutoff_cnt)
871                         *cb->cutoff_cnt = cb->reccnt - 1;
872                 /*
873                  * we have not yet updated cb->[n|o]oid so they still
874                  * hold the values for the previous record.
875                  */
876                 if (!is_null_oid(&cb->ooid)) {
877                         oidcpy(cb->oid, noid);
878                         if (oidcmp(&cb->ooid, noid))
879                                 warning(_("log for ref %s has gap after %s"),
880                                         cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
881                 }
882                 else if (cb->date == cb->at_time)
883                         oidcpy(cb->oid, noid);
884                 else if (oidcmp(noid, cb->oid))
885                         warning(_("log for ref %s unexpectedly ended on %s"),
886                                 cb->refname, show_date(cb->date, cb->tz,
887                                                        DATE_MODE(RFC2822)));
888                 oidcpy(&cb->ooid, ooid);
889                 oidcpy(&cb->noid, noid);
890                 cb->found_it = 1;
891                 return 1;
892         }
893         oidcpy(&cb->ooid, ooid);
894         oidcpy(&cb->noid, noid);
895         if (cb->cnt > 0)
896                 cb->cnt--;
897         return 0;
898 }
899
900 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
901                                   const char *email, timestamp_t timestamp,
902                                   int tz, const char *message, void *cb_data)
903 {
904         struct read_ref_at_cb *cb = cb_data;
905
906         if (cb->msg)
907                 *cb->msg = xstrdup(message);
908         if (cb->cutoff_time)
909                 *cb->cutoff_time = timestamp;
910         if (cb->cutoff_tz)
911                 *cb->cutoff_tz = tz;
912         if (cb->cutoff_cnt)
913                 *cb->cutoff_cnt = cb->reccnt;
914         oidcpy(cb->oid, ooid);
915         if (is_null_oid(cb->oid))
916                 oidcpy(cb->oid, noid);
917         /* We just want the first entry */
918         return 1;
919 }
920
921 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
922                 struct object_id *oid, char **msg,
923                 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
924 {
925         struct read_ref_at_cb cb;
926
927         memset(&cb, 0, sizeof(cb));
928         cb.refname = refname;
929         cb.at_time = at_time;
930         cb.cnt = cnt;
931         cb.msg = msg;
932         cb.cutoff_time = cutoff_time;
933         cb.cutoff_tz = cutoff_tz;
934         cb.cutoff_cnt = cutoff_cnt;
935         cb.oid = oid;
936
937         for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
938
939         if (!cb.reccnt) {
940                 if (flags & GET_OID_QUIETLY)
941                         exit(128);
942                 else
943                         die(_("log for %s is empty"), refname);
944         }
945         if (cb.found_it)
946                 return 0;
947
948         for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
949
950         return 1;
951 }
952
953 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
954                                                     struct strbuf *err)
955 {
956         struct ref_transaction *tr;
957         assert(err);
958
959         tr = xcalloc(1, sizeof(struct ref_transaction));
960         tr->ref_store = refs;
961         return tr;
962 }
963
964 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
965 {
966         return ref_store_transaction_begin(get_main_ref_store(the_repository), err);
967 }
968
969 void ref_transaction_free(struct ref_transaction *transaction)
970 {
971         size_t i;
972
973         if (!transaction)
974                 return;
975
976         switch (transaction->state) {
977         case REF_TRANSACTION_OPEN:
978         case REF_TRANSACTION_CLOSED:
979                 /* OK */
980                 break;
981         case REF_TRANSACTION_PREPARED:
982                 BUG("free called on a prepared reference transaction");
983                 break;
984         default:
985                 BUG("unexpected reference transaction state");
986                 break;
987         }
988
989         for (i = 0; i < transaction->nr; i++) {
990                 free(transaction->updates[i]->msg);
991                 free(transaction->updates[i]);
992         }
993         free(transaction->updates);
994         free(transaction);
995 }
996
997 struct ref_update *ref_transaction_add_update(
998                 struct ref_transaction *transaction,
999                 const char *refname, unsigned int flags,
1000                 const struct object_id *new_oid,
1001                 const struct object_id *old_oid,
1002                 const char *msg)
1003 {
1004         struct ref_update *update;
1005
1006         if (transaction->state != REF_TRANSACTION_OPEN)
1007                 BUG("update called for transaction that is not open");
1008
1009         FLEX_ALLOC_STR(update, refname, refname);
1010         ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
1011         transaction->updates[transaction->nr++] = update;
1012
1013         update->flags = flags;
1014
1015         if (flags & REF_HAVE_NEW)
1016                 oidcpy(&update->new_oid, new_oid);
1017         if (flags & REF_HAVE_OLD)
1018                 oidcpy(&update->old_oid, old_oid);
1019         update->msg = xstrdup_or_null(msg);
1020         return update;
1021 }
1022
1023 int ref_transaction_update(struct ref_transaction *transaction,
1024                            const char *refname,
1025                            const struct object_id *new_oid,
1026                            const struct object_id *old_oid,
1027                            unsigned int flags, const char *msg,
1028                            struct strbuf *err)
1029 {
1030         assert(err);
1031
1032         if ((new_oid && !is_null_oid(new_oid)) ?
1033             check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
1034             !refname_is_safe(refname)) {
1035                 strbuf_addf(err, _("refusing to update ref with bad name '%s'"),
1036                             refname);
1037                 return -1;
1038         }
1039
1040         if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1041                 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1042
1043         flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1044
1045         ref_transaction_add_update(transaction, refname, flags,
1046                                    new_oid, old_oid, msg);
1047         return 0;
1048 }
1049
1050 int ref_transaction_create(struct ref_transaction *transaction,
1051                            const char *refname,
1052                            const struct object_id *new_oid,
1053                            unsigned int flags, const char *msg,
1054                            struct strbuf *err)
1055 {
1056         if (!new_oid || is_null_oid(new_oid))
1057                 BUG("create called without valid new_oid");
1058         return ref_transaction_update(transaction, refname, new_oid,
1059                                       &null_oid, flags, msg, err);
1060 }
1061
1062 int ref_transaction_delete(struct ref_transaction *transaction,
1063                            const char *refname,
1064                            const struct object_id *old_oid,
1065                            unsigned int flags, const char *msg,
1066                            struct strbuf *err)
1067 {
1068         if (old_oid && is_null_oid(old_oid))
1069                 BUG("delete called with old_oid set to zeros");
1070         return ref_transaction_update(transaction, refname,
1071                                       &null_oid, old_oid,
1072                                       flags, msg, err);
1073 }
1074
1075 int ref_transaction_verify(struct ref_transaction *transaction,
1076                            const char *refname,
1077                            const struct object_id *old_oid,
1078                            unsigned int flags,
1079                            struct strbuf *err)
1080 {
1081         if (!old_oid)
1082                 BUG("verify called with old_oid set to NULL");
1083         return ref_transaction_update(transaction, refname,
1084                                       NULL, old_oid,
1085                                       flags, NULL, err);
1086 }
1087
1088 int refs_update_ref(struct ref_store *refs, const char *msg,
1089                     const char *refname, const struct object_id *new_oid,
1090                     const struct object_id *old_oid, unsigned int flags,
1091                     enum action_on_err onerr)
1092 {
1093         struct ref_transaction *t = NULL;
1094         struct strbuf err = STRBUF_INIT;
1095         int ret = 0;
1096
1097         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1098                 assert(refs == get_main_ref_store(the_repository));
1099                 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1100         } else {
1101                 t = ref_store_transaction_begin(refs, &err);
1102                 if (!t ||
1103                     ref_transaction_update(t, refname, new_oid, old_oid,
1104                                            flags, msg, &err) ||
1105                     ref_transaction_commit(t, &err)) {
1106                         ret = 1;
1107                         ref_transaction_free(t);
1108                 }
1109         }
1110         if (ret) {
1111                 const char *str = _("update_ref failed for ref '%s': %s");
1112
1113                 switch (onerr) {
1114                 case UPDATE_REFS_MSG_ON_ERR:
1115                         error(str, refname, err.buf);
1116                         break;
1117                 case UPDATE_REFS_DIE_ON_ERR:
1118                         die(str, refname, err.buf);
1119                         break;
1120                 case UPDATE_REFS_QUIET_ON_ERR:
1121                         break;
1122                 }
1123                 strbuf_release(&err);
1124                 return 1;
1125         }
1126         strbuf_release(&err);
1127         if (t)
1128                 ref_transaction_free(t);
1129         return 0;
1130 }
1131
1132 int update_ref(const char *msg, const char *refname,
1133                const struct object_id *new_oid,
1134                const struct object_id *old_oid,
1135                unsigned int flags, enum action_on_err onerr)
1136 {
1137         return refs_update_ref(get_main_ref_store(the_repository), msg, refname, new_oid,
1138                                old_oid, flags, onerr);
1139 }
1140
1141 char *shorten_unambiguous_ref(const char *refname, int strict)
1142 {
1143         int i;
1144         static char **scanf_fmts;
1145         static int nr_rules;
1146         char *short_name;
1147         struct strbuf resolved_buf = STRBUF_INIT;
1148
1149         if (!nr_rules) {
1150                 /*
1151                  * Pre-generate scanf formats from ref_rev_parse_rules[].
1152                  * Generate a format suitable for scanf from a
1153                  * ref_rev_parse_rules rule by interpolating "%s" at the
1154                  * location of the "%.*s".
1155                  */
1156                 size_t total_len = 0;
1157                 size_t offset = 0;
1158
1159                 /* the rule list is NULL terminated, count them first */
1160                 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1161                         /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1162                         total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1163
1164                 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1165
1166                 offset = 0;
1167                 for (i = 0; i < nr_rules; i++) {
1168                         assert(offset < total_len);
1169                         scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1170                         offset += xsnprintf(scanf_fmts[i], total_len - offset,
1171                                             ref_rev_parse_rules[i], 2, "%s") + 1;
1172                 }
1173         }
1174
1175         /* bail out if there are no rules */
1176         if (!nr_rules)
1177                 return xstrdup(refname);
1178
1179         /* buffer for scanf result, at most refname must fit */
1180         short_name = xstrdup(refname);
1181
1182         /* skip first rule, it will always match */
1183         for (i = nr_rules - 1; i > 0 ; --i) {
1184                 int j;
1185                 int rules_to_fail = i;
1186                 int short_name_len;
1187
1188                 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1189                         continue;
1190
1191                 short_name_len = strlen(short_name);
1192
1193                 /*
1194                  * in strict mode, all (except the matched one) rules
1195                  * must fail to resolve to a valid non-ambiguous ref
1196                  */
1197                 if (strict)
1198                         rules_to_fail = nr_rules;
1199
1200                 /*
1201                  * check if the short name resolves to a valid ref,
1202                  * but use only rules prior to the matched one
1203                  */
1204                 for (j = 0; j < rules_to_fail; j++) {
1205                         const char *rule = ref_rev_parse_rules[j];
1206
1207                         /* skip matched rule */
1208                         if (i == j)
1209                                 continue;
1210
1211                         /*
1212                          * the short name is ambiguous, if it resolves
1213                          * (with this previous rule) to a valid ref
1214                          * read_ref() returns 0 on success
1215                          */
1216                         strbuf_reset(&resolved_buf);
1217                         strbuf_addf(&resolved_buf, rule,
1218                                     short_name_len, short_name);
1219                         if (ref_exists(resolved_buf.buf))
1220                                 break;
1221                 }
1222
1223                 /*
1224                  * short name is non-ambiguous if all previous rules
1225                  * haven't resolved to a valid ref
1226                  */
1227                 if (j == rules_to_fail) {
1228                         strbuf_release(&resolved_buf);
1229                         return short_name;
1230                 }
1231         }
1232
1233         strbuf_release(&resolved_buf);
1234         free(short_name);
1235         return xstrdup(refname);
1236 }
1237
1238 static struct string_list *hide_refs;
1239
1240 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1241 {
1242         const char *key;
1243         if (!strcmp("transfer.hiderefs", var) ||
1244             (!parse_config_key(var, section, NULL, NULL, &key) &&
1245              !strcmp(key, "hiderefs"))) {
1246                 char *ref;
1247                 int len;
1248
1249                 if (!value)
1250                         return config_error_nonbool(var);
1251                 ref = xstrdup(value);
1252                 len = strlen(ref);
1253                 while (len && ref[len - 1] == '/')
1254                         ref[--len] = '\0';
1255                 if (!hide_refs) {
1256                         hide_refs = xcalloc(1, sizeof(*hide_refs));
1257                         hide_refs->strdup_strings = 1;
1258                 }
1259                 string_list_append(hide_refs, ref);
1260         }
1261         return 0;
1262 }
1263
1264 int ref_is_hidden(const char *refname, const char *refname_full)
1265 {
1266         int i;
1267
1268         if (!hide_refs)
1269                 return 0;
1270         for (i = hide_refs->nr - 1; i >= 0; i--) {
1271                 const char *match = hide_refs->items[i].string;
1272                 const char *subject;
1273                 int neg = 0;
1274                 const char *p;
1275
1276                 if (*match == '!') {
1277                         neg = 1;
1278                         match++;
1279                 }
1280
1281                 if (*match == '^') {
1282                         subject = refname_full;
1283                         match++;
1284                 } else {
1285                         subject = refname;
1286                 }
1287
1288                 /* refname can be NULL when namespaces are used. */
1289                 if (subject &&
1290                     skip_prefix(subject, match, &p) &&
1291                     (!*p || *p == '/'))
1292                         return !neg;
1293         }
1294         return 0;
1295 }
1296
1297 const char *find_descendant_ref(const char *dirname,
1298                                 const struct string_list *extras,
1299                                 const struct string_list *skip)
1300 {
1301         int pos;
1302
1303         if (!extras)
1304                 return NULL;
1305
1306         /*
1307          * Look at the place where dirname would be inserted into
1308          * extras. If there is an entry at that position that starts
1309          * with dirname (remember, dirname includes the trailing
1310          * slash) and is not in skip, then we have a conflict.
1311          */
1312         for (pos = string_list_find_insert_index(extras, dirname, 0);
1313              pos < extras->nr; pos++) {
1314                 const char *extra_refname = extras->items[pos].string;
1315
1316                 if (!starts_with(extra_refname, dirname))
1317                         break;
1318
1319                 if (!skip || !string_list_has_string(skip, extra_refname))
1320                         return extra_refname;
1321         }
1322         return NULL;
1323 }
1324
1325 int refs_rename_ref_available(struct ref_store *refs,
1326                               const char *old_refname,
1327                               const char *new_refname)
1328 {
1329         struct string_list skip = STRING_LIST_INIT_NODUP;
1330         struct strbuf err = STRBUF_INIT;
1331         int ok;
1332
1333         string_list_insert(&skip, old_refname);
1334         ok = !refs_verify_refname_available(refs, new_refname,
1335                                             NULL, &skip, &err);
1336         if (!ok)
1337                 error("%s", err.buf);
1338
1339         string_list_clear(&skip, 0);
1340         strbuf_release(&err);
1341         return ok;
1342 }
1343
1344 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1345 {
1346         struct object_id oid;
1347         int flag;
1348
1349         if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1350                                 &oid, &flag))
1351                 return fn("HEAD", &oid, flag, cb_data);
1352
1353         return 0;
1354 }
1355
1356 int head_ref(each_ref_fn fn, void *cb_data)
1357 {
1358         return refs_head_ref(get_main_ref_store(the_repository), fn, cb_data);
1359 }
1360
1361 struct ref_iterator *refs_ref_iterator_begin(
1362                 struct ref_store *refs,
1363                 const char *prefix, int trim, int flags)
1364 {
1365         struct ref_iterator *iter;
1366
1367         if (ref_paranoia < 0)
1368                 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1369         if (ref_paranoia)
1370                 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1371
1372         iter = refs->be->iterator_begin(refs, prefix, flags);
1373
1374         /*
1375          * `iterator_begin()` already takes care of prefix, but we
1376          * might need to do some trimming:
1377          */
1378         if (trim)
1379                 iter = prefix_ref_iterator_begin(iter, "", trim);
1380
1381         /* Sanity check for subclasses: */
1382         if (!iter->ordered)
1383                 BUG("reference iterator is not ordered");
1384
1385         return iter;
1386 }
1387
1388 /*
1389  * Call fn for each reference in the specified submodule for which the
1390  * refname begins with prefix. If trim is non-zero, then trim that
1391  * many characters off the beginning of each refname before passing
1392  * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1393  * include broken references in the iteration. If fn ever returns a
1394  * non-zero value, stop the iteration and return that value;
1395  * otherwise, return 0.
1396  */
1397 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1398                            each_ref_fn fn, int trim, int flags, void *cb_data)
1399 {
1400         struct ref_iterator *iter;
1401
1402         if (!refs)
1403                 return 0;
1404
1405         iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1406
1407         return do_for_each_ref_iterator(iter, fn, cb_data);
1408 }
1409
1410 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1411 {
1412         return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1413 }
1414
1415 int for_each_ref(each_ref_fn fn, void *cb_data)
1416 {
1417         return refs_for_each_ref(get_main_ref_store(the_repository), fn, cb_data);
1418 }
1419
1420 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1421                          each_ref_fn fn, void *cb_data)
1422 {
1423         return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1424 }
1425
1426 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1427 {
1428         return refs_for_each_ref_in(get_main_ref_store(the_repository), prefix, fn, cb_data);
1429 }
1430
1431 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1432 {
1433         unsigned int flag = 0;
1434
1435         if (broken)
1436                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1437         return do_for_each_ref(get_main_ref_store(the_repository),
1438                                prefix, fn, 0, flag, cb_data);
1439 }
1440
1441 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1442                              each_ref_fn fn, void *cb_data,
1443                              unsigned int broken)
1444 {
1445         unsigned int flag = 0;
1446
1447         if (broken)
1448                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1449         return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1450 }
1451
1452 int for_each_replace_ref(struct repository *r, each_ref_fn fn, void *cb_data)
1453 {
1454         return do_for_each_ref(get_main_ref_store(r),
1455                                git_replace_ref_base, fn,
1456                                strlen(git_replace_ref_base),
1457                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1458 }
1459
1460 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1461 {
1462         struct strbuf buf = STRBUF_INIT;
1463         int ret;
1464         strbuf_addf(&buf, "%srefs/", get_git_namespace());
1465         ret = do_for_each_ref(get_main_ref_store(the_repository),
1466                               buf.buf, fn, 0, 0, cb_data);
1467         strbuf_release(&buf);
1468         return ret;
1469 }
1470
1471 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1472 {
1473         return do_for_each_ref(refs, "", fn, 0,
1474                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1475 }
1476
1477 int for_each_rawref(each_ref_fn fn, void *cb_data)
1478 {
1479         return refs_for_each_rawref(get_main_ref_store(the_repository), fn, cb_data);
1480 }
1481
1482 int refs_read_raw_ref(struct ref_store *ref_store,
1483                       const char *refname, struct object_id *oid,
1484                       struct strbuf *referent, unsigned int *type)
1485 {
1486         return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1487 }
1488
1489 /* This function needs to return a meaningful errno on failure */
1490 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1491                                     const char *refname,
1492                                     int resolve_flags,
1493                                     struct object_id *oid, int *flags)
1494 {
1495         static struct strbuf sb_refname = STRBUF_INIT;
1496         struct object_id unused_oid;
1497         int unused_flags;
1498         int symref_count;
1499
1500         if (!oid)
1501                 oid = &unused_oid;
1502         if (!flags)
1503                 flags = &unused_flags;
1504
1505         *flags = 0;
1506
1507         if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1508                 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1509                     !refname_is_safe(refname)) {
1510                         errno = EINVAL;
1511                         return NULL;
1512                 }
1513
1514                 /*
1515                  * dwim_ref() uses REF_ISBROKEN to distinguish between
1516                  * missing refs and refs that were present but invalid,
1517                  * to complain about the latter to stderr.
1518                  *
1519                  * We don't know whether the ref exists, so don't set
1520                  * REF_ISBROKEN yet.
1521                  */
1522                 *flags |= REF_BAD_NAME;
1523         }
1524
1525         for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1526                 unsigned int read_flags = 0;
1527
1528                 if (refs_read_raw_ref(refs, refname,
1529                                       oid, &sb_refname, &read_flags)) {
1530                         *flags |= read_flags;
1531
1532                         /* In reading mode, refs must eventually resolve */
1533                         if (resolve_flags & RESOLVE_REF_READING)
1534                                 return NULL;
1535
1536                         /*
1537                          * Otherwise a missing ref is OK. But the files backend
1538                          * may show errors besides ENOENT if there are
1539                          * similarly-named refs.
1540                          */
1541                         if (errno != ENOENT &&
1542                             errno != EISDIR &&
1543                             errno != ENOTDIR)
1544                                 return NULL;
1545
1546                         oidclr(oid);
1547                         if (*flags & REF_BAD_NAME)
1548                                 *flags |= REF_ISBROKEN;
1549                         return refname;
1550                 }
1551
1552                 *flags |= read_flags;
1553
1554                 if (!(read_flags & REF_ISSYMREF)) {
1555                         if (*flags & REF_BAD_NAME) {
1556                                 oidclr(oid);
1557                                 *flags |= REF_ISBROKEN;
1558                         }
1559                         return refname;
1560                 }
1561
1562                 refname = sb_refname.buf;
1563                 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1564                         oidclr(oid);
1565                         return refname;
1566                 }
1567                 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1568                         if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1569                             !refname_is_safe(refname)) {
1570                                 errno = EINVAL;
1571                                 return NULL;
1572                         }
1573
1574                         *flags |= REF_ISBROKEN | REF_BAD_NAME;
1575                 }
1576         }
1577
1578         errno = ELOOP;
1579         return NULL;
1580 }
1581
1582 /* backend functions */
1583 int refs_init_db(struct strbuf *err)
1584 {
1585         struct ref_store *refs = get_main_ref_store(the_repository);
1586
1587         return refs->be->init_db(refs, err);
1588 }
1589
1590 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1591                                struct object_id *oid, int *flags)
1592 {
1593         return refs_resolve_ref_unsafe(get_main_ref_store(the_repository), refname,
1594                                        resolve_flags, oid, flags);
1595 }
1596
1597 int resolve_gitlink_ref(const char *submodule, const char *refname,
1598                         struct object_id *oid)
1599 {
1600         struct ref_store *refs;
1601         int flags;
1602
1603         refs = get_submodule_ref_store(submodule);
1604
1605         if (!refs)
1606                 return -1;
1607
1608         if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1609             is_null_oid(oid))
1610                 return -1;
1611         return 0;
1612 }
1613
1614 struct ref_store_hash_entry
1615 {
1616         struct hashmap_entry ent; /* must be the first member! */
1617
1618         struct ref_store *refs;
1619
1620         /* NUL-terminated identifier of the ref store: */
1621         char name[FLEX_ARRAY];
1622 };
1623
1624 static int ref_store_hash_cmp(const void *unused_cmp_data,
1625                               const void *entry, const void *entry_or_key,
1626                               const void *keydata)
1627 {
1628         const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1629         const char *name = keydata ? keydata : e2->name;
1630
1631         return strcmp(e1->name, name);
1632 }
1633
1634 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1635                 const char *name, struct ref_store *refs)
1636 {
1637         struct ref_store_hash_entry *entry;
1638
1639         FLEX_ALLOC_STR(entry, name, name);
1640         hashmap_entry_init(entry, strhash(name));
1641         entry->refs = refs;
1642         return entry;
1643 }
1644
1645 /* A hashmap of ref_stores, stored by submodule name: */
1646 static struct hashmap submodule_ref_stores;
1647
1648 /* A hashmap of ref_stores, stored by worktree id: */
1649 static struct hashmap worktree_ref_stores;
1650
1651 /*
1652  * Look up a ref store by name. If that ref_store hasn't been
1653  * registered yet, return NULL.
1654  */
1655 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1656                                               const char *name)
1657 {
1658         struct ref_store_hash_entry *entry;
1659
1660         if (!map->tablesize)
1661                 /* It's initialized on demand in register_ref_store(). */
1662                 return NULL;
1663
1664         entry = hashmap_get_from_hash(map, strhash(name), name);
1665         return entry ? entry->refs : NULL;
1666 }
1667
1668 /*
1669  * Create, record, and return a ref_store instance for the specified
1670  * gitdir.
1671  */
1672 static struct ref_store *ref_store_init(const char *gitdir,
1673                                         unsigned int flags)
1674 {
1675         const char *be_name = "files";
1676         struct ref_storage_be *be = find_ref_storage_backend(be_name);
1677         struct ref_store *refs;
1678
1679         if (!be)
1680                 BUG("reference backend %s is unknown", be_name);
1681
1682         refs = be->init(gitdir, flags);
1683         return refs;
1684 }
1685
1686 struct ref_store *get_main_ref_store(struct repository *r)
1687 {
1688         if (r->refs)
1689                 return r->refs;
1690
1691         if (!r->gitdir)
1692                 BUG("attempting to get main_ref_store outside of repository");
1693
1694         r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
1695         return r->refs;
1696 }
1697
1698 /*
1699  * Associate a ref store with a name. It is a fatal error to call this
1700  * function twice for the same name.
1701  */
1702 static void register_ref_store_map(struct hashmap *map,
1703                                    const char *type,
1704                                    struct ref_store *refs,
1705                                    const char *name)
1706 {
1707         if (!map->tablesize)
1708                 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1709
1710         if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1711                 BUG("%s ref_store '%s' initialized twice", type, name);
1712 }
1713
1714 struct ref_store *get_submodule_ref_store(const char *submodule)
1715 {
1716         struct strbuf submodule_sb = STRBUF_INIT;
1717         struct ref_store *refs;
1718         char *to_free = NULL;
1719         size_t len;
1720
1721         if (!submodule)
1722                 return NULL;
1723
1724         len = strlen(submodule);
1725         while (len && is_dir_sep(submodule[len - 1]))
1726                 len--;
1727         if (!len)
1728                 return NULL;
1729
1730         if (submodule[len])
1731                 /* We need to strip off one or more trailing slashes */
1732                 submodule = to_free = xmemdupz(submodule, len);
1733
1734         refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1735         if (refs)
1736                 goto done;
1737
1738         strbuf_addstr(&submodule_sb, submodule);
1739         if (!is_nonbare_repository_dir(&submodule_sb))
1740                 goto done;
1741
1742         if (submodule_to_gitdir(&submodule_sb, submodule))
1743                 goto done;
1744
1745         /* assume that add_submodule_odb() has been called */
1746         refs = ref_store_init(submodule_sb.buf,
1747                               REF_STORE_READ | REF_STORE_ODB);
1748         register_ref_store_map(&submodule_ref_stores, "submodule",
1749                                refs, submodule);
1750
1751 done:
1752         strbuf_release(&submodule_sb);
1753         free(to_free);
1754
1755         return refs;
1756 }
1757
1758 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1759 {
1760         struct ref_store *refs;
1761         const char *id;
1762
1763         if (wt->is_current)
1764                 return get_main_ref_store(the_repository);
1765
1766         id = wt->id ? wt->id : "/";
1767         refs = lookup_ref_store_map(&worktree_ref_stores, id);
1768         if (refs)
1769                 return refs;
1770
1771         if (wt->id)
1772                 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1773                                       REF_STORE_ALL_CAPS);
1774         else
1775                 refs = ref_store_init(get_git_common_dir(),
1776                                       REF_STORE_ALL_CAPS);
1777
1778         if (refs)
1779                 register_ref_store_map(&worktree_ref_stores, "worktree",
1780                                        refs, id);
1781         return refs;
1782 }
1783
1784 void base_ref_store_init(struct ref_store *refs,
1785                          const struct ref_storage_be *be)
1786 {
1787         refs->be = be;
1788 }
1789
1790 /* backend functions */
1791 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1792 {
1793         return refs->be->pack_refs(refs, flags);
1794 }
1795
1796 int refs_peel_ref(struct ref_store *refs, const char *refname,
1797                   struct object_id *oid)
1798 {
1799         int flag;
1800         struct object_id base;
1801
1802         if (current_ref_iter && current_ref_iter->refname == refname) {
1803                 struct object_id peeled;
1804
1805                 if (ref_iterator_peel(current_ref_iter, &peeled))
1806                         return -1;
1807                 oidcpy(oid, &peeled);
1808                 return 0;
1809         }
1810
1811         if (refs_read_ref_full(refs, refname,
1812                                RESOLVE_REF_READING, &base, &flag))
1813                 return -1;
1814
1815         return peel_object(&base, oid);
1816 }
1817
1818 int peel_ref(const char *refname, struct object_id *oid)
1819 {
1820         return refs_peel_ref(get_main_ref_store(the_repository), refname, oid);
1821 }
1822
1823 int refs_create_symref(struct ref_store *refs,
1824                        const char *ref_target,
1825                        const char *refs_heads_master,
1826                        const char *logmsg)
1827 {
1828         return refs->be->create_symref(refs, ref_target,
1829                                        refs_heads_master,
1830                                        logmsg);
1831 }
1832
1833 int create_symref(const char *ref_target, const char *refs_heads_master,
1834                   const char *logmsg)
1835 {
1836         return refs_create_symref(get_main_ref_store(the_repository), ref_target,
1837                                   refs_heads_master, logmsg);
1838 }
1839
1840 int ref_update_reject_duplicates(struct string_list *refnames,
1841                                  struct strbuf *err)
1842 {
1843         size_t i, n = refnames->nr;
1844
1845         assert(err);
1846
1847         for (i = 1; i < n; i++) {
1848                 int cmp = strcmp(refnames->items[i - 1].string,
1849                                  refnames->items[i].string);
1850
1851                 if (!cmp) {
1852                         strbuf_addf(err,
1853                                     _("multiple updates for ref '%s' not allowed"),
1854                                     refnames->items[i].string);
1855                         return 1;
1856                 } else if (cmp > 0) {
1857                         BUG("ref_update_reject_duplicates() received unsorted list");
1858                 }
1859         }
1860         return 0;
1861 }
1862
1863 int ref_transaction_prepare(struct ref_transaction *transaction,
1864                             struct strbuf *err)
1865 {
1866         struct ref_store *refs = transaction->ref_store;
1867
1868         switch (transaction->state) {
1869         case REF_TRANSACTION_OPEN:
1870                 /* Good. */
1871                 break;
1872         case REF_TRANSACTION_PREPARED:
1873                 BUG("prepare called twice on reference transaction");
1874                 break;
1875         case REF_TRANSACTION_CLOSED:
1876                 BUG("prepare called on a closed reference transaction");
1877                 break;
1878         default:
1879                 BUG("unexpected reference transaction state");
1880                 break;
1881         }
1882
1883         if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1884                 strbuf_addstr(err,
1885                               _("ref updates forbidden inside quarantine environment"));
1886                 return -1;
1887         }
1888
1889         return refs->be->transaction_prepare(refs, transaction, err);
1890 }
1891
1892 int ref_transaction_abort(struct ref_transaction *transaction,
1893                           struct strbuf *err)
1894 {
1895         struct ref_store *refs = transaction->ref_store;
1896         int ret = 0;
1897
1898         switch (transaction->state) {
1899         case REF_TRANSACTION_OPEN:
1900                 /* No need to abort explicitly. */
1901                 break;
1902         case REF_TRANSACTION_PREPARED:
1903                 ret = refs->be->transaction_abort(refs, transaction, err);
1904                 break;
1905         case REF_TRANSACTION_CLOSED:
1906                 BUG("abort called on a closed reference transaction");
1907                 break;
1908         default:
1909                 BUG("unexpected reference transaction state");
1910                 break;
1911         }
1912
1913         ref_transaction_free(transaction);
1914         return ret;
1915 }
1916
1917 int ref_transaction_commit(struct ref_transaction *transaction,
1918                            struct strbuf *err)
1919 {
1920         struct ref_store *refs = transaction->ref_store;
1921         int ret;
1922
1923         switch (transaction->state) {
1924         case REF_TRANSACTION_OPEN:
1925                 /* Need to prepare first. */
1926                 ret = ref_transaction_prepare(transaction, err);
1927                 if (ret)
1928                         return ret;
1929                 break;
1930         case REF_TRANSACTION_PREPARED:
1931                 /* Fall through to finish. */
1932                 break;
1933         case REF_TRANSACTION_CLOSED:
1934                 BUG("commit called on a closed reference transaction");
1935                 break;
1936         default:
1937                 BUG("unexpected reference transaction state");
1938                 break;
1939         }
1940
1941         return refs->be->transaction_finish(refs, transaction, err);
1942 }
1943
1944 int refs_verify_refname_available(struct ref_store *refs,
1945                                   const char *refname,
1946                                   const struct string_list *extras,
1947                                   const struct string_list *skip,
1948                                   struct strbuf *err)
1949 {
1950         const char *slash;
1951         const char *extra_refname;
1952         struct strbuf dirname = STRBUF_INIT;
1953         struct strbuf referent = STRBUF_INIT;
1954         struct object_id oid;
1955         unsigned int type;
1956         struct ref_iterator *iter;
1957         int ok;
1958         int ret = -1;
1959
1960         /*
1961          * For the sake of comments in this function, suppose that
1962          * refname is "refs/foo/bar".
1963          */
1964
1965         assert(err);
1966
1967         strbuf_grow(&dirname, strlen(refname) + 1);
1968         for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1969                 /* Expand dirname to the new prefix, not including the trailing slash: */
1970                 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1971
1972                 /*
1973                  * We are still at a leading dir of the refname (e.g.,
1974                  * "refs/foo"; if there is a reference with that name,
1975                  * it is a conflict, *unless* it is in skip.
1976                  */
1977                 if (skip && string_list_has_string(skip, dirname.buf))
1978                         continue;
1979
1980                 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
1981                         strbuf_addf(err, _("'%s' exists; cannot create '%s'"),
1982                                     dirname.buf, refname);
1983                         goto cleanup;
1984                 }
1985
1986                 if (extras && string_list_has_string(extras, dirname.buf)) {
1987                         strbuf_addf(err, _("cannot process '%s' and '%s' at the same time"),
1988                                     refname, dirname.buf);
1989                         goto cleanup;
1990                 }
1991         }
1992
1993         /*
1994          * We are at the leaf of our refname (e.g., "refs/foo/bar").
1995          * There is no point in searching for a reference with that
1996          * name, because a refname isn't considered to conflict with
1997          * itself. But we still need to check for references whose
1998          * names are in the "refs/foo/bar/" namespace, because they
1999          * *do* conflict.
2000          */
2001         strbuf_addstr(&dirname, refname + dirname.len);
2002         strbuf_addch(&dirname, '/');
2003
2004         iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
2005                                        DO_FOR_EACH_INCLUDE_BROKEN);
2006         while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
2007                 if (skip &&
2008                     string_list_has_string(skip, iter->refname))
2009                         continue;
2010
2011                 strbuf_addf(err, _("'%s' exists; cannot create '%s'"),
2012                             iter->refname, refname);
2013                 ref_iterator_abort(iter);
2014                 goto cleanup;
2015         }
2016
2017         if (ok != ITER_DONE)
2018                 BUG("error while iterating over references");
2019
2020         extra_refname = find_descendant_ref(dirname.buf, extras, skip);
2021         if (extra_refname)
2022                 strbuf_addf(err, _("cannot process '%s' and '%s' at the same time"),
2023                             refname, extra_refname);
2024         else
2025                 ret = 0;
2026
2027 cleanup:
2028         strbuf_release(&referent);
2029         strbuf_release(&dirname);
2030         return ret;
2031 }
2032
2033 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2034 {
2035         struct ref_iterator *iter;
2036
2037         iter = refs->be->reflog_iterator_begin(refs);
2038
2039         return do_for_each_ref_iterator(iter, fn, cb_data);
2040 }
2041
2042 int for_each_reflog(each_ref_fn fn, void *cb_data)
2043 {
2044         return refs_for_each_reflog(get_main_ref_store(the_repository), fn, cb_data);
2045 }
2046
2047 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2048                                      const char *refname,
2049                                      each_reflog_ent_fn fn,
2050                                      void *cb_data)
2051 {
2052         return refs->be->for_each_reflog_ent_reverse(refs, refname,
2053                                                      fn, cb_data);
2054 }
2055
2056 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2057                                 void *cb_data)
2058 {
2059         return refs_for_each_reflog_ent_reverse(get_main_ref_store(the_repository),
2060                                                 refname, fn, cb_data);
2061 }
2062
2063 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2064                              each_reflog_ent_fn fn, void *cb_data)
2065 {
2066         return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2067 }
2068
2069 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2070                         void *cb_data)
2071 {
2072         return refs_for_each_reflog_ent(get_main_ref_store(the_repository), refname,
2073                                         fn, cb_data);
2074 }
2075
2076 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2077 {
2078         return refs->be->reflog_exists(refs, refname);
2079 }
2080
2081 int reflog_exists(const char *refname)
2082 {
2083         return refs_reflog_exists(get_main_ref_store(the_repository), refname);
2084 }
2085
2086 int refs_create_reflog(struct ref_store *refs, const char *refname,
2087                        int force_create, struct strbuf *err)
2088 {
2089         return refs->be->create_reflog(refs, refname, force_create, err);
2090 }
2091
2092 int safe_create_reflog(const char *refname, int force_create,
2093                        struct strbuf *err)
2094 {
2095         return refs_create_reflog(get_main_ref_store(the_repository), refname,
2096                                   force_create, err);
2097 }
2098
2099 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2100 {
2101         return refs->be->delete_reflog(refs, refname);
2102 }
2103
2104 int delete_reflog(const char *refname)
2105 {
2106         return refs_delete_reflog(get_main_ref_store(the_repository), refname);
2107 }
2108
2109 int refs_reflog_expire(struct ref_store *refs,
2110                        const char *refname, const struct object_id *oid,
2111                        unsigned int flags,
2112                        reflog_expiry_prepare_fn prepare_fn,
2113                        reflog_expiry_should_prune_fn should_prune_fn,
2114                        reflog_expiry_cleanup_fn cleanup_fn,
2115                        void *policy_cb_data)
2116 {
2117         return refs->be->reflog_expire(refs, refname, oid, flags,
2118                                        prepare_fn, should_prune_fn,
2119                                        cleanup_fn, policy_cb_data);
2120 }
2121
2122 int reflog_expire(const char *refname, const struct object_id *oid,
2123                   unsigned int flags,
2124                   reflog_expiry_prepare_fn prepare_fn,
2125                   reflog_expiry_should_prune_fn should_prune_fn,
2126                   reflog_expiry_cleanup_fn cleanup_fn,
2127                   void *policy_cb_data)
2128 {
2129         return refs_reflog_expire(get_main_ref_store(the_repository),
2130                                   refname, oid, flags,
2131                                   prepare_fn, should_prune_fn,
2132                                   cleanup_fn, policy_cb_data);
2133 }
2134
2135 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2136                                    struct strbuf *err)
2137 {
2138         struct ref_store *refs = transaction->ref_store;
2139
2140         return refs->be->initial_transaction_commit(refs, transaction, err);
2141 }
2142
2143 int refs_delete_refs(struct ref_store *refs, const char *msg,
2144                      struct string_list *refnames, unsigned int flags)
2145 {
2146         return refs->be->delete_refs(refs, msg, refnames, flags);
2147 }
2148
2149 int delete_refs(const char *msg, struct string_list *refnames,
2150                 unsigned int flags)
2151 {
2152         return refs_delete_refs(get_main_ref_store(the_repository), msg, refnames, flags);
2153 }
2154
2155 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2156                     const char *newref, const char *logmsg)
2157 {
2158         return refs->be->rename_ref(refs, oldref, newref, logmsg);
2159 }
2160
2161 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2162 {
2163         return refs_rename_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2164 }
2165
2166 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2167                     const char *newref, const char *logmsg)
2168 {
2169         return refs->be->copy_ref(refs, oldref, newref, logmsg);
2170 }
2171
2172 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2173 {
2174         return refs_copy_existing_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2175 }