Merge branch 'js/stash-in-c-pathspec-fix'
[git] / remote.c
1 #include "cache.h"
2 #include "config.h"
3 #include "remote.h"
4 #include "refs.h"
5 #include "refspec.h"
6 #include "object-store.h"
7 #include "commit.h"
8 #include "diff.h"
9 #include "revision.h"
10 #include "dir.h"
11 #include "tag.h"
12 #include "string-list.h"
13 #include "mergesort.h"
14 #include "argv-array.h"
15 #include "commit-reach.h"
16 #include "advice.h"
17
18 enum map_direction { FROM_SRC, FROM_DST };
19
20 struct counted_string {
21         size_t len;
22         const char *s;
23 };
24 struct rewrite {
25         const char *base;
26         size_t baselen;
27         struct counted_string *instead_of;
28         int instead_of_nr;
29         int instead_of_alloc;
30 };
31 struct rewrites {
32         struct rewrite **rewrite;
33         int rewrite_alloc;
34         int rewrite_nr;
35 };
36
37 static struct remote **remotes;
38 static int remotes_alloc;
39 static int remotes_nr;
40 static struct hashmap remotes_hash;
41
42 static struct branch **branches;
43 static int branches_alloc;
44 static int branches_nr;
45
46 static struct branch *current_branch;
47 static const char *pushremote_name;
48
49 static struct rewrites rewrites;
50 static struct rewrites rewrites_push;
51
52 static int valid_remote(const struct remote *remote)
53 {
54         return (!!remote->url) || (!!remote->foreign_vcs);
55 }
56
57 static const char *alias_url(const char *url, struct rewrites *r)
58 {
59         int i, j;
60         struct counted_string *longest;
61         int longest_i;
62
63         longest = NULL;
64         longest_i = -1;
65         for (i = 0; i < r->rewrite_nr; i++) {
66                 if (!r->rewrite[i])
67                         continue;
68                 for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
69                         if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
70                             (!longest ||
71                              longest->len < r->rewrite[i]->instead_of[j].len)) {
72                                 longest = &(r->rewrite[i]->instead_of[j]);
73                                 longest_i = i;
74                         }
75                 }
76         }
77         if (!longest)
78                 return url;
79
80         return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
81 }
82
83 static void add_url(struct remote *remote, const char *url)
84 {
85         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
86         remote->url[remote->url_nr++] = url;
87 }
88
89 static void add_pushurl(struct remote *remote, const char *pushurl)
90 {
91         ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
92         remote->pushurl[remote->pushurl_nr++] = pushurl;
93 }
94
95 static void add_pushurl_alias(struct remote *remote, const char *url)
96 {
97         const char *pushurl = alias_url(url, &rewrites_push);
98         if (pushurl != url)
99                 add_pushurl(remote, pushurl);
100 }
101
102 static void add_url_alias(struct remote *remote, const char *url)
103 {
104         add_url(remote, alias_url(url, &rewrites));
105         add_pushurl_alias(remote, url);
106 }
107
108 struct remotes_hash_key {
109         const char *str;
110         int len;
111 };
112
113 static int remotes_hash_cmp(const void *unused_cmp_data,
114                             const void *entry,
115                             const void *entry_or_key,
116                             const void *keydata)
117 {
118         const struct remote *a = entry;
119         const struct remote *b = entry_or_key;
120         const struct remotes_hash_key *key = keydata;
121
122         if (key)
123                 return strncmp(a->name, key->str, key->len) || a->name[key->len];
124         else
125                 return strcmp(a->name, b->name);
126 }
127
128 static inline void init_remotes_hash(void)
129 {
130         if (!remotes_hash.cmpfn)
131                 hashmap_init(&remotes_hash, remotes_hash_cmp, NULL, 0);
132 }
133
134 static struct remote *make_remote(const char *name, int len)
135 {
136         struct remote *ret, *replaced;
137         struct remotes_hash_key lookup;
138         struct hashmap_entry lookup_entry;
139
140         if (!len)
141                 len = strlen(name);
142
143         init_remotes_hash();
144         lookup.str = name;
145         lookup.len = len;
146         hashmap_entry_init(&lookup_entry, memhash(name, len));
147
148         if ((ret = hashmap_get(&remotes_hash, &lookup_entry, &lookup)) != NULL)
149                 return ret;
150
151         ret = xcalloc(1, sizeof(struct remote));
152         ret->prune = -1;  /* unspecified */
153         ret->prune_tags = -1;  /* unspecified */
154         ret->name = xstrndup(name, len);
155         refspec_init(&ret->push, REFSPEC_PUSH);
156         refspec_init(&ret->fetch, REFSPEC_FETCH);
157
158         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
159         remotes[remotes_nr++] = ret;
160
161         hashmap_entry_init(ret, lookup_entry.hash);
162         replaced = hashmap_put(&remotes_hash, ret);
163         assert(replaced == NULL);  /* no previous entry overwritten */
164         return ret;
165 }
166
167 static void add_merge(struct branch *branch, const char *name)
168 {
169         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
170                    branch->merge_alloc);
171         branch->merge_name[branch->merge_nr++] = name;
172 }
173
174 static struct branch *make_branch(const char *name, int len)
175 {
176         struct branch *ret;
177         int i;
178
179         for (i = 0; i < branches_nr; i++) {
180                 if (len ? (!strncmp(name, branches[i]->name, len) &&
181                            !branches[i]->name[len]) :
182                     !strcmp(name, branches[i]->name))
183                         return branches[i];
184         }
185
186         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
187         ret = xcalloc(1, sizeof(struct branch));
188         branches[branches_nr++] = ret;
189         if (len)
190                 ret->name = xstrndup(name, len);
191         else
192                 ret->name = xstrdup(name);
193         ret->refname = xstrfmt("refs/heads/%s", ret->name);
194
195         return ret;
196 }
197
198 static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
199 {
200         struct rewrite *ret;
201         int i;
202
203         for (i = 0; i < r->rewrite_nr; i++) {
204                 if (len
205                     ? (len == r->rewrite[i]->baselen &&
206                        !strncmp(base, r->rewrite[i]->base, len))
207                     : !strcmp(base, r->rewrite[i]->base))
208                         return r->rewrite[i];
209         }
210
211         ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
212         ret = xcalloc(1, sizeof(struct rewrite));
213         r->rewrite[r->rewrite_nr++] = ret;
214         if (len) {
215                 ret->base = xstrndup(base, len);
216                 ret->baselen = len;
217         }
218         else {
219                 ret->base = xstrdup(base);
220                 ret->baselen = strlen(base);
221         }
222         return ret;
223 }
224
225 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
226 {
227         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
228         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
229         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
230         rewrite->instead_of_nr++;
231 }
232
233 static const char *skip_spaces(const char *s)
234 {
235         while (isspace(*s))
236                 s++;
237         return s;
238 }
239
240 static void read_remotes_file(struct remote *remote)
241 {
242         struct strbuf buf = STRBUF_INIT;
243         FILE *f = fopen_or_warn(git_path("remotes/%s", remote->name), "r");
244
245         if (!f)
246                 return;
247         remote->configured_in_repo = 1;
248         remote->origin = REMOTE_REMOTES;
249         while (strbuf_getline(&buf, f) != EOF) {
250                 const char *v;
251
252                 strbuf_rtrim(&buf);
253
254                 if (skip_prefix(buf.buf, "URL:", &v))
255                         add_url_alias(remote, xstrdup(skip_spaces(v)));
256                 else if (skip_prefix(buf.buf, "Push:", &v))
257                         refspec_append(&remote->push, skip_spaces(v));
258                 else if (skip_prefix(buf.buf, "Pull:", &v))
259                         refspec_append(&remote->fetch, skip_spaces(v));
260         }
261         strbuf_release(&buf);
262         fclose(f);
263 }
264
265 static void read_branches_file(struct remote *remote)
266 {
267         char *frag;
268         struct strbuf buf = STRBUF_INIT;
269         FILE *f = fopen_or_warn(git_path("branches/%s", remote->name), "r");
270
271         if (!f)
272                 return;
273
274         strbuf_getline_lf(&buf, f);
275         fclose(f);
276         strbuf_trim(&buf);
277         if (!buf.len) {
278                 strbuf_release(&buf);
279                 return;
280         }
281
282         remote->configured_in_repo = 1;
283         remote->origin = REMOTE_BRANCHES;
284
285         /*
286          * The branches file would have URL and optionally
287          * #branch specified.  The "master" (or specified) branch is
288          * fetched and stored in the local branch matching the
289          * remote name.
290          */
291         frag = strchr(buf.buf, '#');
292         if (frag)
293                 *(frag++) = '\0';
294         else
295                 frag = "master";
296
297         add_url_alias(remote, strbuf_detach(&buf, NULL));
298         strbuf_addf(&buf, "refs/heads/%s:refs/heads/%s",
299                     frag, remote->name);
300         refspec_append(&remote->fetch, buf.buf);
301
302         /*
303          * Cogito compatible push: push current HEAD to remote #branch
304          * (master if missing)
305          */
306         strbuf_reset(&buf);
307         strbuf_addf(&buf, "HEAD:refs/heads/%s", frag);
308         refspec_append(&remote->push, buf.buf);
309         remote->fetch_tags = 1; /* always auto-follow */
310         strbuf_release(&buf);
311 }
312
313 static int handle_config(const char *key, const char *value, void *cb)
314 {
315         const char *name;
316         int namelen;
317         const char *subkey;
318         struct remote *remote;
319         struct branch *branch;
320         if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
321                 if (!name)
322                         return 0;
323                 branch = make_branch(name, namelen);
324                 if (!strcmp(subkey, "remote")) {
325                         return git_config_string(&branch->remote_name, key, value);
326                 } else if (!strcmp(subkey, "pushremote")) {
327                         return git_config_string(&branch->pushremote_name, key, value);
328                 } else if (!strcmp(subkey, "merge")) {
329                         if (!value)
330                                 return config_error_nonbool(key);
331                         add_merge(branch, xstrdup(value));
332                 }
333                 return 0;
334         }
335         if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
336                 struct rewrite *rewrite;
337                 if (!name)
338                         return 0;
339                 if (!strcmp(subkey, "insteadof")) {
340                         if (!value)
341                                 return config_error_nonbool(key);
342                         rewrite = make_rewrite(&rewrites, name, namelen);
343                         add_instead_of(rewrite, xstrdup(value));
344                 } else if (!strcmp(subkey, "pushinsteadof")) {
345                         if (!value)
346                                 return config_error_nonbool(key);
347                         rewrite = make_rewrite(&rewrites_push, name, namelen);
348                         add_instead_of(rewrite, xstrdup(value));
349                 }
350         }
351
352         if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
353                 return 0;
354
355         /* Handle remote.* variables */
356         if (!name && !strcmp(subkey, "pushdefault"))
357                 return git_config_string(&pushremote_name, key, value);
358
359         if (!name)
360                 return 0;
361         /* Handle remote.<name>.* variables */
362         if (*name == '/') {
363                 warning(_("config remote shorthand cannot begin with '/': %s"),
364                         name);
365                 return 0;
366         }
367         remote = make_remote(name, namelen);
368         remote->origin = REMOTE_CONFIG;
369         if (current_config_scope() == CONFIG_SCOPE_REPO)
370                 remote->configured_in_repo = 1;
371         if (!strcmp(subkey, "mirror"))
372                 remote->mirror = git_config_bool(key, value);
373         else if (!strcmp(subkey, "skipdefaultupdate"))
374                 remote->skip_default_update = git_config_bool(key, value);
375         else if (!strcmp(subkey, "skipfetchall"))
376                 remote->skip_default_update = git_config_bool(key, value);
377         else if (!strcmp(subkey, "prune"))
378                 remote->prune = git_config_bool(key, value);
379         else if (!strcmp(subkey, "prunetags"))
380                 remote->prune_tags = git_config_bool(key, value);
381         else if (!strcmp(subkey, "url")) {
382                 const char *v;
383                 if (git_config_string(&v, key, value))
384                         return -1;
385                 add_url(remote, v);
386         } else if (!strcmp(subkey, "pushurl")) {
387                 const char *v;
388                 if (git_config_string(&v, key, value))
389                         return -1;
390                 add_pushurl(remote, v);
391         } else if (!strcmp(subkey, "push")) {
392                 const char *v;
393                 if (git_config_string(&v, key, value))
394                         return -1;
395                 refspec_append(&remote->push, v);
396                 free((char *)v);
397         } else if (!strcmp(subkey, "fetch")) {
398                 const char *v;
399                 if (git_config_string(&v, key, value))
400                         return -1;
401                 refspec_append(&remote->fetch, v);
402                 free((char *)v);
403         } else if (!strcmp(subkey, "receivepack")) {
404                 const char *v;
405                 if (git_config_string(&v, key, value))
406                         return -1;
407                 if (!remote->receivepack)
408                         remote->receivepack = v;
409                 else
410                         error(_("more than one receivepack given, using the first"));
411         } else if (!strcmp(subkey, "uploadpack")) {
412                 const char *v;
413                 if (git_config_string(&v, key, value))
414                         return -1;
415                 if (!remote->uploadpack)
416                         remote->uploadpack = v;
417                 else
418                         error(_("more than one uploadpack given, using the first"));
419         } else if (!strcmp(subkey, "tagopt")) {
420                 if (!strcmp(value, "--no-tags"))
421                         remote->fetch_tags = -1;
422                 else if (!strcmp(value, "--tags"))
423                         remote->fetch_tags = 2;
424         } else if (!strcmp(subkey, "proxy")) {
425                 return git_config_string((const char **)&remote->http_proxy,
426                                          key, value);
427         } else if (!strcmp(subkey, "proxyauthmethod")) {
428                 return git_config_string((const char **)&remote->http_proxy_authmethod,
429                                          key, value);
430         } else if (!strcmp(subkey, "vcs")) {
431                 return git_config_string(&remote->foreign_vcs, key, value);
432         }
433         return 0;
434 }
435
436 static void alias_all_urls(void)
437 {
438         int i, j;
439         for (i = 0; i < remotes_nr; i++) {
440                 int add_pushurl_aliases;
441                 if (!remotes[i])
442                         continue;
443                 for (j = 0; j < remotes[i]->pushurl_nr; j++) {
444                         remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j], &rewrites);
445                 }
446                 add_pushurl_aliases = remotes[i]->pushurl_nr == 0;
447                 for (j = 0; j < remotes[i]->url_nr; j++) {
448                         if (add_pushurl_aliases)
449                                 add_pushurl_alias(remotes[i], remotes[i]->url[j]);
450                         remotes[i]->url[j] = alias_url(remotes[i]->url[j], &rewrites);
451                 }
452         }
453 }
454
455 static void read_config(void)
456 {
457         static int loaded;
458         int flag;
459
460         if (loaded)
461                 return;
462         loaded = 1;
463
464         current_branch = NULL;
465         if (startup_info->have_repository) {
466                 const char *head_ref = resolve_ref_unsafe("HEAD", 0, NULL, &flag);
467                 if (head_ref && (flag & REF_ISSYMREF) &&
468                     skip_prefix(head_ref, "refs/heads/", &head_ref)) {
469                         current_branch = make_branch(head_ref, 0);
470                 }
471         }
472         git_config(handle_config, NULL);
473         alias_all_urls();
474 }
475
476 static int valid_remote_nick(const char *name)
477 {
478         if (!name[0] || is_dot_or_dotdot(name))
479                 return 0;
480
481         /* remote nicknames cannot contain slashes */
482         while (*name)
483                 if (is_dir_sep(*name++))
484                         return 0;
485         return 1;
486 }
487
488 const char *remote_for_branch(struct branch *branch, int *explicit)
489 {
490         if (branch && branch->remote_name) {
491                 if (explicit)
492                         *explicit = 1;
493                 return branch->remote_name;
494         }
495         if (explicit)
496                 *explicit = 0;
497         return "origin";
498 }
499
500 const char *pushremote_for_branch(struct branch *branch, int *explicit)
501 {
502         if (branch && branch->pushremote_name) {
503                 if (explicit)
504                         *explicit = 1;
505                 return branch->pushremote_name;
506         }
507         if (pushremote_name) {
508                 if (explicit)
509                         *explicit = 1;
510                 return pushremote_name;
511         }
512         return remote_for_branch(branch, explicit);
513 }
514
515 const char *remote_ref_for_branch(struct branch *branch, int for_push,
516                                   int *explicit)
517 {
518         if (branch) {
519                 if (!for_push) {
520                         if (branch->merge_nr) {
521                                 if (explicit)
522                                         *explicit = 1;
523                                 return branch->merge_name[0];
524                         }
525                 } else {
526                         const char *dst, *remote_name =
527                                 pushremote_for_branch(branch, NULL);
528                         struct remote *remote = remote_get(remote_name);
529
530                         if (remote && remote->push.nr &&
531                             (dst = apply_refspecs(&remote->push,
532                                                   branch->refname))) {
533                                 if (explicit)
534                                         *explicit = 1;
535                                 return dst;
536                         }
537                 }
538         }
539         if (explicit)
540                 *explicit = 0;
541         return "";
542 }
543
544 static struct remote *remote_get_1(const char *name,
545                                    const char *(*get_default)(struct branch *, int *))
546 {
547         struct remote *ret;
548         int name_given = 0;
549
550         read_config();
551
552         if (name)
553                 name_given = 1;
554         else
555                 name = get_default(current_branch, &name_given);
556
557         ret = make_remote(name, 0);
558         if (valid_remote_nick(name) && have_git_dir()) {
559                 if (!valid_remote(ret))
560                         read_remotes_file(ret);
561                 if (!valid_remote(ret))
562                         read_branches_file(ret);
563         }
564         if (name_given && !valid_remote(ret))
565                 add_url_alias(ret, name);
566         if (!valid_remote(ret))
567                 return NULL;
568         return ret;
569 }
570
571 struct remote *remote_get(const char *name)
572 {
573         return remote_get_1(name, remote_for_branch);
574 }
575
576 struct remote *pushremote_get(const char *name)
577 {
578         return remote_get_1(name, pushremote_for_branch);
579 }
580
581 int remote_is_configured(struct remote *remote, int in_repo)
582 {
583         if (!remote)
584                 return 0;
585         if (in_repo)
586                 return remote->configured_in_repo;
587         return !!remote->origin;
588 }
589
590 int for_each_remote(each_remote_fn fn, void *priv)
591 {
592         int i, result = 0;
593         read_config();
594         for (i = 0; i < remotes_nr && !result; i++) {
595                 struct remote *r = remotes[i];
596                 if (!r)
597                         continue;
598                 result = fn(r, priv);
599         }
600         return result;
601 }
602
603 static void handle_duplicate(struct ref *ref1, struct ref *ref2)
604 {
605         if (strcmp(ref1->name, ref2->name)) {
606                 if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
607                     ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
608                         die(_("Cannot fetch both %s and %s to %s"),
609                             ref1->name, ref2->name, ref2->peer_ref->name);
610                 } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
611                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
612                         warning(_("%s usually tracks %s, not %s"),
613                                 ref2->peer_ref->name, ref2->name, ref1->name);
614                 } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
615                            ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
616                         die(_("%s tracks both %s and %s"),
617                             ref2->peer_ref->name, ref1->name, ref2->name);
618                 } else {
619                         /*
620                          * This last possibility doesn't occur because
621                          * FETCH_HEAD_IGNORE entries always appear at
622                          * the end of the list.
623                          */
624                         BUG("Internal error");
625                 }
626         }
627         free(ref2->peer_ref);
628         free(ref2);
629 }
630
631 struct ref *ref_remove_duplicates(struct ref *ref_map)
632 {
633         struct string_list refs = STRING_LIST_INIT_NODUP;
634         struct ref *retval = NULL;
635         struct ref **p = &retval;
636
637         while (ref_map) {
638                 struct ref *ref = ref_map;
639
640                 ref_map = ref_map->next;
641                 ref->next = NULL;
642
643                 if (!ref->peer_ref) {
644                         *p = ref;
645                         p = &ref->next;
646                 } else {
647                         struct string_list_item *item =
648                                 string_list_insert(&refs, ref->peer_ref->name);
649
650                         if (item->util) {
651                                 /* Entry already existed */
652                                 handle_duplicate((struct ref *)item->util, ref);
653                         } else {
654                                 *p = ref;
655                                 p = &ref->next;
656                                 item->util = ref;
657                         }
658                 }
659         }
660
661         string_list_clear(&refs, 0);
662         return retval;
663 }
664
665 int remote_has_url(struct remote *remote, const char *url)
666 {
667         int i;
668         for (i = 0; i < remote->url_nr; i++) {
669                 if (!strcmp(remote->url[i], url))
670                         return 1;
671         }
672         return 0;
673 }
674
675 static int match_name_with_pattern(const char *key, const char *name,
676                                    const char *value, char **result)
677 {
678         const char *kstar = strchr(key, '*');
679         size_t klen;
680         size_t ksuffixlen;
681         size_t namelen;
682         int ret;
683         if (!kstar)
684                 die(_("key '%s' of pattern had no '*'"), key);
685         klen = kstar - key;
686         ksuffixlen = strlen(kstar + 1);
687         namelen = strlen(name);
688         ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
689                 !memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
690         if (ret && value) {
691                 struct strbuf sb = STRBUF_INIT;
692                 const char *vstar = strchr(value, '*');
693                 if (!vstar)
694                         die(_("value '%s' of pattern has no '*'"), value);
695                 strbuf_add(&sb, value, vstar - value);
696                 strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
697                 strbuf_addstr(&sb, vstar + 1);
698                 *result = strbuf_detach(&sb, NULL);
699         }
700         return ret;
701 }
702
703 static void query_refspecs_multiple(struct refspec *rs,
704                                     struct refspec_item *query,
705                                     struct string_list *results)
706 {
707         int i;
708         int find_src = !query->src;
709
710         if (find_src && !query->dst)
711                 BUG("query_refspecs_multiple: need either src or dst");
712
713         for (i = 0; i < rs->nr; i++) {
714                 struct refspec_item *refspec = &rs->items[i];
715                 const char *key = find_src ? refspec->dst : refspec->src;
716                 const char *value = find_src ? refspec->src : refspec->dst;
717                 const char *needle = find_src ? query->dst : query->src;
718                 char **result = find_src ? &query->src : &query->dst;
719
720                 if (!refspec->dst)
721                         continue;
722                 if (refspec->pattern) {
723                         if (match_name_with_pattern(key, needle, value, result))
724                                 string_list_append_nodup(results, *result);
725                 } else if (!strcmp(needle, key)) {
726                         string_list_append(results, value);
727                 }
728         }
729 }
730
731 int query_refspecs(struct refspec *rs, struct refspec_item *query)
732 {
733         int i;
734         int find_src = !query->src;
735         const char *needle = find_src ? query->dst : query->src;
736         char **result = find_src ? &query->src : &query->dst;
737
738         if (find_src && !query->dst)
739                 BUG("query_refspecs: need either src or dst");
740
741         for (i = 0; i < rs->nr; i++) {
742                 struct refspec_item *refspec = &rs->items[i];
743                 const char *key = find_src ? refspec->dst : refspec->src;
744                 const char *value = find_src ? refspec->src : refspec->dst;
745
746                 if (!refspec->dst)
747                         continue;
748                 if (refspec->pattern) {
749                         if (match_name_with_pattern(key, needle, value, result)) {
750                                 query->force = refspec->force;
751                                 return 0;
752                         }
753                 } else if (!strcmp(needle, key)) {
754                         *result = xstrdup(value);
755                         query->force = refspec->force;
756                         return 0;
757                 }
758         }
759         return -1;
760 }
761
762 char *apply_refspecs(struct refspec *rs, const char *name)
763 {
764         struct refspec_item query;
765
766         memset(&query, 0, sizeof(struct refspec_item));
767         query.src = (char *)name;
768
769         if (query_refspecs(rs, &query))
770                 return NULL;
771
772         return query.dst;
773 }
774
775 int remote_find_tracking(struct remote *remote, struct refspec_item *refspec)
776 {
777         return query_refspecs(&remote->fetch, refspec);
778 }
779
780 static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
781                 const char *name)
782 {
783         size_t len = strlen(name);
784         struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
785         memcpy(ref->name, prefix, prefixlen);
786         memcpy(ref->name + prefixlen, name, len);
787         return ref;
788 }
789
790 struct ref *alloc_ref(const char *name)
791 {
792         return alloc_ref_with_prefix("", 0, name);
793 }
794
795 struct ref *copy_ref(const struct ref *ref)
796 {
797         struct ref *cpy;
798         size_t len;
799         if (!ref)
800                 return NULL;
801         len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
802         cpy = xmalloc(len);
803         memcpy(cpy, ref, len);
804         cpy->next = NULL;
805         cpy->symref = xstrdup_or_null(ref->symref);
806         cpy->remote_status = xstrdup_or_null(ref->remote_status);
807         cpy->peer_ref = copy_ref(ref->peer_ref);
808         return cpy;
809 }
810
811 struct ref *copy_ref_list(const struct ref *ref)
812 {
813         struct ref *ret = NULL;
814         struct ref **tail = &ret;
815         while (ref) {
816                 *tail = copy_ref(ref);
817                 ref = ref->next;
818                 tail = &((*tail)->next);
819         }
820         return ret;
821 }
822
823 static void free_ref(struct ref *ref)
824 {
825         if (!ref)
826                 return;
827         free_ref(ref->peer_ref);
828         free(ref->remote_status);
829         free(ref->symref);
830         free(ref);
831 }
832
833 void free_refs(struct ref *ref)
834 {
835         struct ref *next;
836         while (ref) {
837                 next = ref->next;
838                 free_ref(ref);
839                 ref = next;
840         }
841 }
842
843 int ref_compare_name(const void *va, const void *vb)
844 {
845         const struct ref *a = va, *b = vb;
846         return strcmp(a->name, b->name);
847 }
848
849 static void *ref_list_get_next(const void *a)
850 {
851         return ((const struct ref *)a)->next;
852 }
853
854 static void ref_list_set_next(void *a, void *next)
855 {
856         ((struct ref *)a)->next = next;
857 }
858
859 void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
860 {
861         *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
862 }
863
864 int count_refspec_match(const char *pattern,
865                         struct ref *refs,
866                         struct ref **matched_ref)
867 {
868         int patlen = strlen(pattern);
869         struct ref *matched_weak = NULL;
870         struct ref *matched = NULL;
871         int weak_match = 0;
872         int match = 0;
873
874         for (weak_match = match = 0; refs; refs = refs->next) {
875                 char *name = refs->name;
876                 int namelen = strlen(name);
877
878                 if (!refname_match(pattern, name))
879                         continue;
880
881                 /* A match is "weak" if it is with refs outside
882                  * heads or tags, and did not specify the pattern
883                  * in full (e.g. "refs/remotes/origin/master") or at
884                  * least from the toplevel (e.g. "remotes/origin/master");
885                  * otherwise "git push $URL master" would result in
886                  * ambiguity between remotes/origin/master and heads/master
887                  * at the remote site.
888                  */
889                 if (namelen != patlen &&
890                     patlen != namelen - 5 &&
891                     !starts_with(name, "refs/heads/") &&
892                     !starts_with(name, "refs/tags/")) {
893                         /* We want to catch the case where only weak
894                          * matches are found and there are multiple
895                          * matches, and where more than one strong
896                          * matches are found, as ambiguous.  One
897                          * strong match with zero or more weak matches
898                          * are acceptable as a unique match.
899                          */
900                         matched_weak = refs;
901                         weak_match++;
902                 }
903                 else {
904                         matched = refs;
905                         match++;
906                 }
907         }
908         if (!matched) {
909                 if (matched_ref)
910                         *matched_ref = matched_weak;
911                 return weak_match;
912         }
913         else {
914                 if (matched_ref)
915                         *matched_ref = matched;
916                 return match;
917         }
918 }
919
920 static void tail_link_ref(struct ref *ref, struct ref ***tail)
921 {
922         **tail = ref;
923         while (ref->next)
924                 ref = ref->next;
925         *tail = &ref->next;
926 }
927
928 static struct ref *alloc_delete_ref(void)
929 {
930         struct ref *ref = alloc_ref("(delete)");
931         oidclr(&ref->new_oid);
932         return ref;
933 }
934
935 static int try_explicit_object_name(const char *name,
936                                     struct ref **match)
937 {
938         struct object_id oid;
939
940         if (!*name) {
941                 if (match)
942                         *match = alloc_delete_ref();
943                 return 0;
944         }
945
946         if (get_oid(name, &oid))
947                 return -1;
948
949         if (match) {
950                 *match = alloc_ref(name);
951                 oidcpy(&(*match)->new_oid, &oid);
952         }
953         return 0;
954 }
955
956 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
957 {
958         struct ref *ret = alloc_ref(name);
959         tail_link_ref(ret, tail);
960         return ret;
961 }
962
963 static char *guess_ref(const char *name, struct ref *peer)
964 {
965         struct strbuf buf = STRBUF_INIT;
966
967         const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
968                                            NULL, NULL);
969         if (!r)
970                 return NULL;
971
972         if (starts_with(r, "refs/heads/")) {
973                 strbuf_addstr(&buf, "refs/heads/");
974         } else if (starts_with(r, "refs/tags/")) {
975                 strbuf_addstr(&buf, "refs/tags/");
976         } else {
977                 return NULL;
978         }
979
980         strbuf_addstr(&buf, name);
981         return strbuf_detach(&buf, NULL);
982 }
983
984 static int match_explicit_lhs(struct ref *src,
985                               struct refspec_item *rs,
986                               struct ref **match,
987                               int *allocated_match)
988 {
989         switch (count_refspec_match(rs->src, src, match)) {
990         case 1:
991                 if (allocated_match)
992                         *allocated_match = 0;
993                 return 0;
994         case 0:
995                 /* The source could be in the get_sha1() format
996                  * not a reference name.  :refs/other is a
997                  * way to delete 'other' ref at the remote end.
998                  */
999                 if (try_explicit_object_name(rs->src, match) < 0)
1000                         return error(_("src refspec %s does not match any"), rs->src);
1001                 if (allocated_match)
1002                         *allocated_match = 1;
1003                 return 0;
1004         default:
1005                 return error(_("src refspec %s matches more than one"), rs->src);
1006         }
1007 }
1008
1009 static void show_push_unqualified_ref_name_error(const char *dst_value,
1010                                                  const char *matched_src_name)
1011 {
1012         struct object_id oid;
1013         enum object_type type;
1014
1015         /*
1016          * TRANSLATORS: "matches '%s'%" is the <dst> part of "git push
1017          * <remote> <src>:<dst>" push, and "being pushed ('%s')" is
1018          * the <src>.
1019          */
1020         error(_("The destination you provided is not a full refname (i.e.,\n"
1021                 "starting with \"refs/\"). We tried to guess what you meant by:\n"
1022                 "\n"
1023                 "- Looking for a ref that matches '%s' on the remote side.\n"
1024                 "- Checking if the <src> being pushed ('%s')\n"
1025                 "  is a ref in \"refs/{heads,tags}/\". If so we add a corresponding\n"
1026                 "  refs/{heads,tags}/ prefix on the remote side.\n"
1027                 "\n"
1028                 "Neither worked, so we gave up. You must fully qualify the ref."),
1029               dst_value, matched_src_name);
1030
1031         if (!advice_push_unqualified_ref_name)
1032                 return;
1033
1034         if (get_oid(matched_src_name, &oid))
1035                 BUG("'%s' is not a valid object, "
1036                     "match_explicit_lhs() should catch this!",
1037                     matched_src_name);
1038         type = oid_object_info(the_repository, &oid, NULL);
1039         if (type == OBJ_COMMIT) {
1040                 advise(_("The <src> part of the refspec is a commit object.\n"
1041                          "Did you mean to create a new branch by pushing to\n"
1042                          "'%s:refs/heads/%s'?"),
1043                        matched_src_name, dst_value);
1044         } else if (type == OBJ_TAG) {
1045                 advise(_("The <src> part of the refspec is a tag object.\n"
1046                          "Did you mean to create a new tag by pushing to\n"
1047                          "'%s:refs/tags/%s'?"),
1048                        matched_src_name, dst_value);
1049         } else if (type == OBJ_TREE) {
1050                 advise(_("The <src> part of the refspec is a tree object.\n"
1051                          "Did you mean to tag a new tree by pushing to\n"
1052                          "'%s:refs/tags/%s'?"),
1053                        matched_src_name, dst_value);
1054         } else if (type == OBJ_BLOB) {
1055                 advise(_("The <src> part of the refspec is a blob object.\n"
1056                          "Did you mean to tag a new blob by pushing to\n"
1057                          "'%s:refs/tags/%s'?"),
1058                        matched_src_name, dst_value);
1059         } else {
1060                 BUG("'%s' should be commit/tag/tree/blob, is '%d'",
1061                     matched_src_name, type);
1062         }
1063 }
1064
1065 static int match_explicit(struct ref *src, struct ref *dst,
1066                           struct ref ***dst_tail,
1067                           struct refspec_item *rs)
1068 {
1069         struct ref *matched_src, *matched_dst;
1070         int allocated_src;
1071
1072         const char *dst_value = rs->dst;
1073         char *dst_guess;
1074
1075         if (rs->pattern || rs->matching)
1076                 return 0;
1077
1078         matched_src = matched_dst = NULL;
1079         if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
1080                 return -1;
1081
1082         if (!dst_value) {
1083                 int flag;
1084
1085                 dst_value = resolve_ref_unsafe(matched_src->name,
1086                                                RESOLVE_REF_READING,
1087                                                NULL, &flag);
1088                 if (!dst_value ||
1089                     ((flag & REF_ISSYMREF) &&
1090                      !starts_with(dst_value, "refs/heads/")))
1091                         die(_("%s cannot be resolved to branch"),
1092                             matched_src->name);
1093         }
1094
1095         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
1096         case 1:
1097                 break;
1098         case 0:
1099                 if (starts_with(dst_value, "refs/")) {
1100                         matched_dst = make_linked_ref(dst_value, dst_tail);
1101                 } else if (is_null_oid(&matched_src->new_oid)) {
1102                         error(_("unable to delete '%s': remote ref does not exist"),
1103                               dst_value);
1104                 } else if ((dst_guess = guess_ref(dst_value, matched_src))) {
1105                         matched_dst = make_linked_ref(dst_guess, dst_tail);
1106                         free(dst_guess);
1107                 } else {
1108                         show_push_unqualified_ref_name_error(dst_value,
1109                                                              matched_src->name);
1110                 }
1111                 break;
1112         default:
1113                 matched_dst = NULL;
1114                 error(_("dst refspec %s matches more than one"),
1115                       dst_value);
1116                 break;
1117         }
1118         if (!matched_dst)
1119                 return -1;
1120         if (matched_dst->peer_ref)
1121                 return error(_("dst ref %s receives from more than one src"),
1122                              matched_dst->name);
1123         else {
1124                 matched_dst->peer_ref = allocated_src ?
1125                                         matched_src :
1126                                         copy_ref(matched_src);
1127                 matched_dst->force = rs->force;
1128         }
1129         return 0;
1130 }
1131
1132 static int match_explicit_refs(struct ref *src, struct ref *dst,
1133                                struct ref ***dst_tail, struct refspec *rs)
1134 {
1135         int i, errs;
1136         for (i = errs = 0; i < rs->nr; i++)
1137                 errs += match_explicit(src, dst, dst_tail, &rs->items[i]);
1138         return errs;
1139 }
1140
1141 static char *get_ref_match(const struct refspec *rs, const struct ref *ref,
1142                            int send_mirror, int direction,
1143                            const struct refspec_item **ret_pat)
1144 {
1145         const struct refspec_item *pat;
1146         char *name;
1147         int i;
1148         int matching_refs = -1;
1149         for (i = 0; i < rs->nr; i++) {
1150                 const struct refspec_item *item = &rs->items[i];
1151                 if (item->matching &&
1152                     (matching_refs == -1 || item->force)) {
1153                         matching_refs = i;
1154                         continue;
1155                 }
1156
1157                 if (item->pattern) {
1158                         const char *dst_side = item->dst ? item->dst : item->src;
1159                         int match;
1160                         if (direction == FROM_SRC)
1161                                 match = match_name_with_pattern(item->src, ref->name, dst_side, &name);
1162                         else
1163                                 match = match_name_with_pattern(dst_side, ref->name, item->src, &name);
1164                         if (match) {
1165                                 matching_refs = i;
1166                                 break;
1167                         }
1168                 }
1169         }
1170         if (matching_refs == -1)
1171                 return NULL;
1172
1173         pat = &rs->items[matching_refs];
1174         if (pat->matching) {
1175                 /*
1176                  * "matching refs"; traditionally we pushed everything
1177                  * including refs outside refs/heads/ hierarchy, but
1178                  * that does not make much sense these days.
1179                  */
1180                 if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
1181                         return NULL;
1182                 name = xstrdup(ref->name);
1183         }
1184         if (ret_pat)
1185                 *ret_pat = pat;
1186         return name;
1187 }
1188
1189 static struct ref **tail_ref(struct ref **head)
1190 {
1191         struct ref **tail = head;
1192         while (*tail)
1193                 tail = &((*tail)->next);
1194         return tail;
1195 }
1196
1197 struct tips {
1198         struct commit **tip;
1199         int nr, alloc;
1200 };
1201
1202 static void add_to_tips(struct tips *tips, const struct object_id *oid)
1203 {
1204         struct commit *commit;
1205
1206         if (is_null_oid(oid))
1207                 return;
1208         commit = lookup_commit_reference_gently(the_repository, oid, 1);
1209         if (!commit || (commit->object.flags & TMP_MARK))
1210                 return;
1211         commit->object.flags |= TMP_MARK;
1212         ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
1213         tips->tip[tips->nr++] = commit;
1214 }
1215
1216 static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
1217 {
1218         struct string_list dst_tag = STRING_LIST_INIT_NODUP;
1219         struct string_list src_tag = STRING_LIST_INIT_NODUP;
1220         struct string_list_item *item;
1221         struct ref *ref;
1222         struct tips sent_tips;
1223
1224         /*
1225          * Collect everything we know they would have at the end of
1226          * this push, and collect all tags they have.
1227          */
1228         memset(&sent_tips, 0, sizeof(sent_tips));
1229         for (ref = *dst; ref; ref = ref->next) {
1230                 if (ref->peer_ref &&
1231                     !is_null_oid(&ref->peer_ref->new_oid))
1232                         add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
1233                 else
1234                         add_to_tips(&sent_tips, &ref->old_oid);
1235                 if (starts_with(ref->name, "refs/tags/"))
1236                         string_list_append(&dst_tag, ref->name);
1237         }
1238         clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
1239
1240         string_list_sort(&dst_tag);
1241
1242         /* Collect tags they do not have. */
1243         for (ref = src; ref; ref = ref->next) {
1244                 if (!starts_with(ref->name, "refs/tags/"))
1245                         continue; /* not a tag */
1246                 if (string_list_has_string(&dst_tag, ref->name))
1247                         continue; /* they already have it */
1248                 if (oid_object_info(the_repository, &ref->new_oid, NULL) != OBJ_TAG)
1249                         continue; /* be conservative */
1250                 item = string_list_append(&src_tag, ref->name);
1251                 item->util = ref;
1252         }
1253         string_list_clear(&dst_tag, 0);
1254
1255         /*
1256          * At this point, src_tag lists tags that are missing from
1257          * dst, and sent_tips lists the tips we are pushing or those
1258          * that we know they already have. An element in the src_tag
1259          * that is an ancestor of any of the sent_tips needs to be
1260          * sent to the other side.
1261          */
1262         if (sent_tips.nr) {
1263                 const int reachable_flag = 1;
1264                 struct commit_list *found_commits;
1265                 struct commit **src_commits;
1266                 int nr_src_commits = 0, alloc_src_commits = 16;
1267                 ALLOC_ARRAY(src_commits, alloc_src_commits);
1268
1269                 for_each_string_list_item(item, &src_tag) {
1270                         struct ref *ref = item->util;
1271                         struct commit *commit;
1272
1273                         if (is_null_oid(&ref->new_oid))
1274                                 continue;
1275                         commit = lookup_commit_reference_gently(the_repository,
1276                                                                 &ref->new_oid,
1277                                                                 1);
1278                         if (!commit)
1279                                 /* not pushing a commit, which is not an error */
1280                                 continue;
1281
1282                         ALLOC_GROW(src_commits, nr_src_commits + 1, alloc_src_commits);
1283                         src_commits[nr_src_commits++] = commit;
1284                 }
1285
1286                 found_commits = get_reachable_subset(sent_tips.tip, sent_tips.nr,
1287                                                      src_commits, nr_src_commits,
1288                                                      reachable_flag);
1289
1290                 for_each_string_list_item(item, &src_tag) {
1291                         struct ref *dst_ref;
1292                         struct ref *ref = item->util;
1293                         struct commit *commit;
1294
1295                         if (is_null_oid(&ref->new_oid))
1296                                 continue;
1297                         commit = lookup_commit_reference_gently(the_repository,
1298                                                                 &ref->new_oid,
1299                                                                 1);
1300                         if (!commit)
1301                                 /* not pushing a commit, which is not an error */
1302                                 continue;
1303
1304                         /*
1305                          * Is this tag, which they do not have, reachable from
1306                          * any of the commits we are sending?
1307                          */
1308                         if (!(commit->object.flags & reachable_flag))
1309                                 continue;
1310
1311                         /* Add it in */
1312                         dst_ref = make_linked_ref(ref->name, dst_tail);
1313                         oidcpy(&dst_ref->new_oid, &ref->new_oid);
1314                         dst_ref->peer_ref = copy_ref(ref);
1315                 }
1316
1317                 clear_commit_marks_many(nr_src_commits, src_commits, reachable_flag);
1318                 free(src_commits);
1319                 free_commit_list(found_commits);
1320         }
1321
1322         string_list_clear(&src_tag, 0);
1323         free(sent_tips.tip);
1324 }
1325
1326 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1327 {
1328         for ( ; list; list = list->next)
1329                 if (!strcmp(list->name, name))
1330                         return (struct ref *)list;
1331         return NULL;
1332 }
1333
1334 static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
1335 {
1336         for ( ; ref; ref = ref->next)
1337                 string_list_append_nodup(ref_index, ref->name)->util = ref;
1338
1339         string_list_sort(ref_index);
1340 }
1341
1342 /*
1343  * Given only the set of local refs, sanity-check the set of push
1344  * refspecs. We can't catch all errors that match_push_refs would,
1345  * but we can catch some errors early before even talking to the
1346  * remote side.
1347  */
1348 int check_push_refs(struct ref *src, struct refspec *rs)
1349 {
1350         int ret = 0;
1351         int i;
1352
1353         for (i = 0; i < rs->nr; i++) {
1354                 struct refspec_item *item = &rs->items[i];
1355
1356                 if (item->pattern || item->matching)
1357                         continue;
1358
1359                 ret |= match_explicit_lhs(src, item, NULL, NULL);
1360         }
1361
1362         return ret;
1363 }
1364
1365 /*
1366  * Given the set of refs the local repository has, the set of refs the
1367  * remote repository has, and the refspec used for push, determine
1368  * what remote refs we will update and with what value by setting
1369  * peer_ref (which object is being pushed) and force (if the push is
1370  * forced) in elements of "dst". The function may add new elements to
1371  * dst (e.g. pushing to a new branch, done in match_explicit_refs).
1372  */
1373 int match_push_refs(struct ref *src, struct ref **dst,
1374                     struct refspec *rs, int flags)
1375 {
1376         int send_all = flags & MATCH_REFS_ALL;
1377         int send_mirror = flags & MATCH_REFS_MIRROR;
1378         int send_prune = flags & MATCH_REFS_PRUNE;
1379         int errs;
1380         struct ref *ref, **dst_tail = tail_ref(dst);
1381         struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;
1382
1383         /* If no refspec is provided, use the default ":" */
1384         if (!rs->nr)
1385                 refspec_append(rs, ":");
1386
1387         errs = match_explicit_refs(src, *dst, &dst_tail, rs);
1388
1389         /* pick the remainder */
1390         for (ref = src; ref; ref = ref->next) {
1391                 struct string_list_item *dst_item;
1392                 struct ref *dst_peer;
1393                 const struct refspec_item *pat = NULL;
1394                 char *dst_name;
1395
1396                 dst_name = get_ref_match(rs, ref, send_mirror, FROM_SRC, &pat);
1397                 if (!dst_name)
1398                         continue;
1399
1400                 if (!dst_ref_index.nr)
1401                         prepare_ref_index(&dst_ref_index, *dst);
1402
1403                 dst_item = string_list_lookup(&dst_ref_index, dst_name);
1404                 dst_peer = dst_item ? dst_item->util : NULL;
1405                 if (dst_peer) {
1406                         if (dst_peer->peer_ref)
1407                                 /* We're already sending something to this ref. */
1408                                 goto free_name;
1409                 } else {
1410                         if (pat->matching && !(send_all || send_mirror))
1411                                 /*
1412                                  * Remote doesn't have it, and we have no
1413                                  * explicit pattern, and we don't have
1414                                  * --all or --mirror.
1415                                  */
1416                                 goto free_name;
1417
1418                         /* Create a new one and link it */
1419                         dst_peer = make_linked_ref(dst_name, &dst_tail);
1420                         oidcpy(&dst_peer->new_oid, &ref->new_oid);
1421                         string_list_insert(&dst_ref_index,
1422                                 dst_peer->name)->util = dst_peer;
1423                 }
1424                 dst_peer->peer_ref = copy_ref(ref);
1425                 dst_peer->force = pat->force;
1426         free_name:
1427                 free(dst_name);
1428         }
1429
1430         string_list_clear(&dst_ref_index, 0);
1431
1432         if (flags & MATCH_REFS_FOLLOW_TAGS)
1433                 add_missing_tags(src, dst, &dst_tail);
1434
1435         if (send_prune) {
1436                 struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
1437                 /* check for missing refs on the remote */
1438                 for (ref = *dst; ref; ref = ref->next) {
1439                         char *src_name;
1440
1441                         if (ref->peer_ref)
1442                                 /* We're already sending something to this ref. */
1443                                 continue;
1444
1445                         src_name = get_ref_match(rs, ref, send_mirror, FROM_DST, NULL);
1446                         if (src_name) {
1447                                 if (!src_ref_index.nr)
1448                                         prepare_ref_index(&src_ref_index, src);
1449                                 if (!string_list_has_string(&src_ref_index,
1450                                             src_name))
1451                                         ref->peer_ref = alloc_delete_ref();
1452                                 free(src_name);
1453                         }
1454                 }
1455                 string_list_clear(&src_ref_index, 0);
1456         }
1457
1458         if (errs)
1459                 return -1;
1460         return 0;
1461 }
1462
1463 void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
1464                              int force_update)
1465 {
1466         struct ref *ref;
1467
1468         for (ref = remote_refs; ref; ref = ref->next) {
1469                 int force_ref_update = ref->force || force_update;
1470                 int reject_reason = 0;
1471
1472                 if (ref->peer_ref)
1473                         oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
1474                 else if (!send_mirror)
1475                         continue;
1476
1477                 ref->deletion = is_null_oid(&ref->new_oid);
1478                 if (!ref->deletion &&
1479                         oideq(&ref->old_oid, &ref->new_oid)) {
1480                         ref->status = REF_STATUS_UPTODATE;
1481                         continue;
1482                 }
1483
1484                 /*
1485                  * If the remote ref has moved and is now different
1486                  * from what we expect, reject any push.
1487                  *
1488                  * It also is an error if the user told us to check
1489                  * with the remote-tracking branch to find the value
1490                  * to expect, but we did not have such a tracking
1491                  * branch.
1492                  */
1493                 if (ref->expect_old_sha1) {
1494                         if (!oideq(&ref->old_oid, &ref->old_oid_expect))
1495                                 reject_reason = REF_STATUS_REJECT_STALE;
1496                         else
1497                                 /* If the ref isn't stale then force the update. */
1498                                 force_ref_update = 1;
1499                 }
1500
1501                 /*
1502                  * If the update isn't already rejected then check
1503                  * the usual "must fast-forward" rules.
1504                  *
1505                  * Decide whether an individual refspec A:B can be
1506                  * pushed.  The push will succeed if any of the
1507                  * following are true:
1508                  *
1509                  * (1) the remote reference B does not exist
1510                  *
1511                  * (2) the remote reference B is being removed (i.e.,
1512                  *     pushing :B where no source is specified)
1513                  *
1514                  * (3) the destination is not under refs/tags/, and
1515                  *     if the old and new value is a commit, the new
1516                  *     is a descendant of the old.
1517                  *
1518                  * (4) it is forced using the +A:B notation, or by
1519                  *     passing the --force argument
1520                  */
1521
1522                 if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
1523                         if (starts_with(ref->name, "refs/tags/"))
1524                                 reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
1525                         else if (!has_object_file(&ref->old_oid))
1526                                 reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
1527                         else if (!lookup_commit_reference_gently(the_repository, &ref->old_oid, 1) ||
1528                                  !lookup_commit_reference_gently(the_repository, &ref->new_oid, 1))
1529                                 reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
1530                         else if (!ref_newer(&ref->new_oid, &ref->old_oid))
1531                                 reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
1532                 }
1533
1534                 /*
1535                  * "--force" will defeat any rejection implemented
1536                  * by the rules above.
1537                  */
1538                 if (!force_ref_update)
1539                         ref->status = reject_reason;
1540                 else if (reject_reason)
1541                         ref->forced_update = 1;
1542         }
1543 }
1544
1545 static void set_merge(struct branch *ret)
1546 {
1547         struct remote *remote;
1548         char *ref;
1549         struct object_id oid;
1550         int i;
1551
1552         if (!ret)
1553                 return; /* no branch */
1554         if (ret->merge)
1555                 return; /* already run */
1556         if (!ret->remote_name || !ret->merge_nr) {
1557                 /*
1558                  * no merge config; let's make sure we don't confuse callers
1559                  * with a non-zero merge_nr but a NULL merge
1560                  */
1561                 ret->merge_nr = 0;
1562                 return;
1563         }
1564
1565         remote = remote_get(ret->remote_name);
1566
1567         ret->merge = xcalloc(ret->merge_nr, sizeof(*ret->merge));
1568         for (i = 0; i < ret->merge_nr; i++) {
1569                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1570                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1571                 if (!remote_find_tracking(remote, ret->merge[i]) ||
1572                     strcmp(ret->remote_name, "."))
1573                         continue;
1574                 if (dwim_ref(ret->merge_name[i], strlen(ret->merge_name[i]),
1575                              &oid, &ref) == 1)
1576                         ret->merge[i]->dst = ref;
1577                 else
1578                         ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
1579         }
1580 }
1581
1582 struct branch *branch_get(const char *name)
1583 {
1584         struct branch *ret;
1585
1586         read_config();
1587         if (!name || !*name || !strcmp(name, "HEAD"))
1588                 ret = current_branch;
1589         else
1590                 ret = make_branch(name, 0);
1591         set_merge(ret);
1592         return ret;
1593 }
1594
1595 int branch_has_merge_config(struct branch *branch)
1596 {
1597         return branch && !!branch->merge;
1598 }
1599
1600 int branch_merge_matches(struct branch *branch,
1601                                  int i,
1602                                  const char *refname)
1603 {
1604         if (!branch || i < 0 || i >= branch->merge_nr)
1605                 return 0;
1606         return refname_match(branch->merge[i]->src, refname);
1607 }
1608
1609 __attribute__((format (printf,2,3)))
1610 static const char *error_buf(struct strbuf *err, const char *fmt, ...)
1611 {
1612         if (err) {
1613                 va_list ap;
1614                 va_start(ap, fmt);
1615                 strbuf_vaddf(err, fmt, ap);
1616                 va_end(ap);
1617         }
1618         return NULL;
1619 }
1620
1621 const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
1622 {
1623         if (!branch)
1624                 return error_buf(err, _("HEAD does not point to a branch"));
1625
1626         if (!branch->merge || !branch->merge[0]) {
1627                 /*
1628                  * no merge config; is it because the user didn't define any,
1629                  * or because it is not a real branch, and get_branch
1630                  * auto-vivified it?
1631                  */
1632                 if (!ref_exists(branch->refname))
1633                         return error_buf(err, _("no such branch: '%s'"),
1634                                          branch->name);
1635                 return error_buf(err,
1636                                  _("no upstream configured for branch '%s'"),
1637                                  branch->name);
1638         }
1639
1640         if (!branch->merge[0]->dst)
1641                 return error_buf(err,
1642                                  _("upstream branch '%s' not stored as a remote-tracking branch"),
1643                                  branch->merge[0]->src);
1644
1645         return branch->merge[0]->dst;
1646 }
1647
1648 static const char *tracking_for_push_dest(struct remote *remote,
1649                                           const char *refname,
1650                                           struct strbuf *err)
1651 {
1652         char *ret;
1653
1654         ret = apply_refspecs(&remote->fetch, refname);
1655         if (!ret)
1656                 return error_buf(err,
1657                                  _("push destination '%s' on remote '%s' has no local tracking branch"),
1658                                  refname, remote->name);
1659         return ret;
1660 }
1661
1662 static const char *branch_get_push_1(struct branch *branch, struct strbuf *err)
1663 {
1664         struct remote *remote;
1665
1666         remote = remote_get(pushremote_for_branch(branch, NULL));
1667         if (!remote)
1668                 return error_buf(err,
1669                                  _("branch '%s' has no remote for pushing"),
1670                                  branch->name);
1671
1672         if (remote->push.nr) {
1673                 char *dst;
1674                 const char *ret;
1675
1676                 dst = apply_refspecs(&remote->push, branch->refname);
1677                 if (!dst)
1678                         return error_buf(err,
1679                                          _("push refspecs for '%s' do not include '%s'"),
1680                                          remote->name, branch->name);
1681
1682                 ret = tracking_for_push_dest(remote, dst, err);
1683                 free(dst);
1684                 return ret;
1685         }
1686
1687         if (remote->mirror)
1688                 return tracking_for_push_dest(remote, branch->refname, err);
1689
1690         switch (push_default) {
1691         case PUSH_DEFAULT_NOTHING:
1692                 return error_buf(err, _("push has no destination (push.default is 'nothing')"));
1693
1694         case PUSH_DEFAULT_MATCHING:
1695         case PUSH_DEFAULT_CURRENT:
1696                 return tracking_for_push_dest(remote, branch->refname, err);
1697
1698         case PUSH_DEFAULT_UPSTREAM:
1699                 return branch_get_upstream(branch, err);
1700
1701         case PUSH_DEFAULT_UNSPECIFIED:
1702         case PUSH_DEFAULT_SIMPLE:
1703                 {
1704                         const char *up, *cur;
1705
1706                         up = branch_get_upstream(branch, err);
1707                         if (!up)
1708                                 return NULL;
1709                         cur = tracking_for_push_dest(remote, branch->refname, err);
1710                         if (!cur)
1711                                 return NULL;
1712                         if (strcmp(cur, up))
1713                                 return error_buf(err,
1714                                                  _("cannot resolve 'simple' push to a single destination"));
1715                         return cur;
1716                 }
1717         }
1718
1719         BUG("unhandled push situation");
1720 }
1721
1722 const char *branch_get_push(struct branch *branch, struct strbuf *err)
1723 {
1724         if (!branch)
1725                 return error_buf(err, _("HEAD does not point to a branch"));
1726
1727         if (!branch->push_tracking_ref)
1728                 branch->push_tracking_ref = branch_get_push_1(branch, err);
1729         return branch->push_tracking_ref;
1730 }
1731
1732 static int ignore_symref_update(const char *refname)
1733 {
1734         int flag;
1735
1736         if (!resolve_ref_unsafe(refname, 0, NULL, &flag))
1737                 return 0; /* non-existing refs are OK */
1738         return (flag & REF_ISSYMREF);
1739 }
1740
1741 /*
1742  * Create and return a list of (struct ref) consisting of copies of
1743  * each remote_ref that matches refspec.  refspec must be a pattern.
1744  * Fill in the copies' peer_ref to describe the local tracking refs to
1745  * which they map.  Omit any references that would map to an existing
1746  * local symbolic ref.
1747  */
1748 static struct ref *get_expanded_map(const struct ref *remote_refs,
1749                                     const struct refspec_item *refspec)
1750 {
1751         const struct ref *ref;
1752         struct ref *ret = NULL;
1753         struct ref **tail = &ret;
1754
1755         for (ref = remote_refs; ref; ref = ref->next) {
1756                 char *expn_name = NULL;
1757
1758                 if (strchr(ref->name, '^'))
1759                         continue; /* a dereference item */
1760                 if (match_name_with_pattern(refspec->src, ref->name,
1761                                             refspec->dst, &expn_name) &&
1762                     !ignore_symref_update(expn_name)) {
1763                         struct ref *cpy = copy_ref(ref);
1764
1765                         cpy->peer_ref = alloc_ref(expn_name);
1766                         if (refspec->force)
1767                                 cpy->peer_ref->force = 1;
1768                         *tail = cpy;
1769                         tail = &cpy->next;
1770                 }
1771                 free(expn_name);
1772         }
1773
1774         return ret;
1775 }
1776
1777 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1778 {
1779         const struct ref *ref;
1780         const struct ref *best_match = NULL;
1781         int best_score = 0;
1782
1783         for (ref = refs; ref; ref = ref->next) {
1784                 int score = refname_match(name, ref->name);
1785
1786                 if (best_score < score) {
1787                         best_match = ref;
1788                         best_score = score;
1789                 }
1790         }
1791         return best_match;
1792 }
1793
1794 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1795 {
1796         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1797
1798         if (!ref)
1799                 return NULL;
1800
1801         return copy_ref(ref);
1802 }
1803
1804 static struct ref *get_local_ref(const char *name)
1805 {
1806         if (!name || name[0] == '\0')
1807                 return NULL;
1808
1809         if (starts_with(name, "refs/"))
1810                 return alloc_ref(name);
1811
1812         if (starts_with(name, "heads/") ||
1813             starts_with(name, "tags/") ||
1814             starts_with(name, "remotes/"))
1815                 return alloc_ref_with_prefix("refs/", 5, name);
1816
1817         return alloc_ref_with_prefix("refs/heads/", 11, name);
1818 }
1819
1820 int get_fetch_map(const struct ref *remote_refs,
1821                   const struct refspec_item *refspec,
1822                   struct ref ***tail,
1823                   int missing_ok)
1824 {
1825         struct ref *ref_map, **rmp;
1826
1827         if (refspec->pattern) {
1828                 ref_map = get_expanded_map(remote_refs, refspec);
1829         } else {
1830                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1831
1832                 if (refspec->exact_sha1) {
1833                         ref_map = alloc_ref(name);
1834                         get_oid_hex(name, &ref_map->old_oid);
1835                         ref_map->exact_oid = 1;
1836                 } else {
1837                         ref_map = get_remote_ref(remote_refs, name);
1838                 }
1839                 if (!missing_ok && !ref_map)
1840                         die(_("couldn't find remote ref %s"), name);
1841                 if (ref_map) {
1842                         ref_map->peer_ref = get_local_ref(refspec->dst);
1843                         if (ref_map->peer_ref && refspec->force)
1844                                 ref_map->peer_ref->force = 1;
1845                 }
1846         }
1847
1848         for (rmp = &ref_map; *rmp; ) {
1849                 if ((*rmp)->peer_ref) {
1850                         if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
1851                             check_refname_format((*rmp)->peer_ref->name, 0)) {
1852                                 struct ref *ignore = *rmp;
1853                                 error(_("* Ignoring funny ref '%s' locally"),
1854                                       (*rmp)->peer_ref->name);
1855                                 *rmp = (*rmp)->next;
1856                                 free(ignore->peer_ref);
1857                                 free(ignore);
1858                                 continue;
1859                         }
1860                 }
1861                 rmp = &((*rmp)->next);
1862         }
1863
1864         if (ref_map)
1865                 tail_link_ref(ref_map, tail);
1866
1867         return 0;
1868 }
1869
1870 int resolve_remote_symref(struct ref *ref, struct ref *list)
1871 {
1872         if (!ref->symref)
1873                 return 0;
1874         for (; list; list = list->next)
1875                 if (!strcmp(ref->symref, list->name)) {
1876                         oidcpy(&ref->old_oid, &list->old_oid);
1877                         return 0;
1878                 }
1879         return 1;
1880 }
1881
1882 /*
1883  * Lookup the upstream branch for the given branch and if present, optionally
1884  * compute the commit ahead/behind values for the pair.
1885  *
1886  * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
1887  * counts in *num_ours and *num_theirs.  If abf is AHEAD_BEHIND_QUICK, skip
1888  * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
1889  * set to zero).
1890  *
1891  * The name of the upstream branch (or NULL if no upstream is defined) is
1892  * returned via *upstream_name, if it is not itself NULL.
1893  *
1894  * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
1895  * upstream defined, or ref does not exist).  Returns 0 if the commits are
1896  * identical.  Returns 1 if commits are different.
1897  */
1898 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
1899                        const char **upstream_name, enum ahead_behind_flags abf)
1900 {
1901         struct object_id oid;
1902         struct commit *ours, *theirs;
1903         struct rev_info revs;
1904         const char *base;
1905         struct argv_array argv = ARGV_ARRAY_INIT;
1906
1907         /* Cannot stat unless we are marked to build on top of somebody else. */
1908         base = branch_get_upstream(branch, NULL);
1909         if (upstream_name)
1910                 *upstream_name = base;
1911         if (!base)
1912                 return -1;
1913
1914         /* Cannot stat if what we used to build on no longer exists */
1915         if (read_ref(base, &oid))
1916                 return -1;
1917         theirs = lookup_commit_reference(the_repository, &oid);
1918         if (!theirs)
1919                 return -1;
1920
1921         if (read_ref(branch->refname, &oid))
1922                 return -1;
1923         ours = lookup_commit_reference(the_repository, &oid);
1924         if (!ours)
1925                 return -1;
1926
1927         *num_theirs = *num_ours = 0;
1928
1929         /* are we the same? */
1930         if (theirs == ours)
1931                 return 0;
1932         if (abf == AHEAD_BEHIND_QUICK)
1933                 return 1;
1934         if (abf != AHEAD_BEHIND_FULL)
1935                 BUG("stat_tracking_info: invalid abf '%d'", abf);
1936
1937         /* Run "rev-list --left-right ours...theirs" internally... */
1938         argv_array_push(&argv, ""); /* ignored */
1939         argv_array_push(&argv, "--left-right");
1940         argv_array_pushf(&argv, "%s...%s",
1941                          oid_to_hex(&ours->object.oid),
1942                          oid_to_hex(&theirs->object.oid));
1943         argv_array_push(&argv, "--");
1944
1945         repo_init_revisions(the_repository, &revs, NULL);
1946         setup_revisions(argv.argc, argv.argv, &revs, NULL);
1947         if (prepare_revision_walk(&revs))
1948                 die(_("revision walk setup failed"));
1949
1950         /* ... and count the commits on each side. */
1951         while (1) {
1952                 struct commit *c = get_revision(&revs);
1953                 if (!c)
1954                         break;
1955                 if (c->object.flags & SYMMETRIC_LEFT)
1956                         (*num_ours)++;
1957                 else
1958                         (*num_theirs)++;
1959         }
1960
1961         /* clear object flags smudged by the above traversal */
1962         clear_commit_marks(ours, ALL_REV_FLAGS);
1963         clear_commit_marks(theirs, ALL_REV_FLAGS);
1964
1965         argv_array_clear(&argv);
1966         return 1;
1967 }
1968
1969 /*
1970  * Return true when there is anything to report, otherwise false.
1971  */
1972 int format_tracking_info(struct branch *branch, struct strbuf *sb,
1973                          enum ahead_behind_flags abf)
1974 {
1975         int ours, theirs, sti;
1976         const char *full_base;
1977         char *base;
1978         int upstream_is_gone = 0;
1979
1980         sti = stat_tracking_info(branch, &ours, &theirs, &full_base, abf);
1981         if (sti < 0) {
1982                 if (!full_base)
1983                         return 0;
1984                 upstream_is_gone = 1;
1985         }
1986
1987         base = shorten_unambiguous_ref(full_base, 0);
1988         if (upstream_is_gone) {
1989                 strbuf_addf(sb,
1990                         _("Your branch is based on '%s', but the upstream is gone.\n"),
1991                         base);
1992                 if (advice_status_hints)
1993                         strbuf_addstr(sb,
1994                                 _("  (use \"git branch --unset-upstream\" to fixup)\n"));
1995         } else if (!sti) {
1996                 strbuf_addf(sb,
1997                         _("Your branch is up to date with '%s'.\n"),
1998                         base);
1999         } else if (abf == AHEAD_BEHIND_QUICK) {
2000                 strbuf_addf(sb,
2001                             _("Your branch and '%s' refer to different commits.\n"),
2002                             base);
2003                 if (advice_status_hints)
2004                         strbuf_addf(sb, _("  (use \"%s\" for details)\n"),
2005                                     "git status --ahead-behind");
2006         } else if (!theirs) {
2007                 strbuf_addf(sb,
2008                         Q_("Your branch is ahead of '%s' by %d commit.\n",
2009                            "Your branch is ahead of '%s' by %d commits.\n",
2010                            ours),
2011                         base, ours);
2012                 if (advice_status_hints)
2013                         strbuf_addstr(sb,
2014                                 _("  (use \"git push\" to publish your local commits)\n"));
2015         } else if (!ours) {
2016                 strbuf_addf(sb,
2017                         Q_("Your branch is behind '%s' by %d commit, "
2018                                "and can be fast-forwarded.\n",
2019                            "Your branch is behind '%s' by %d commits, "
2020                                "and can be fast-forwarded.\n",
2021                            theirs),
2022                         base, theirs);
2023                 if (advice_status_hints)
2024                         strbuf_addstr(sb,
2025                                 _("  (use \"git pull\" to update your local branch)\n"));
2026         } else {
2027                 strbuf_addf(sb,
2028                         Q_("Your branch and '%s' have diverged,\n"
2029                                "and have %d and %d different commit each, "
2030                                "respectively.\n",
2031                            "Your branch and '%s' have diverged,\n"
2032                                "and have %d and %d different commits each, "
2033                                "respectively.\n",
2034                            ours + theirs),
2035                         base, ours, theirs);
2036                 if (advice_status_hints)
2037                         strbuf_addstr(sb,
2038                                 _("  (use \"git pull\" to merge the remote branch into yours)\n"));
2039         }
2040         free(base);
2041         return 1;
2042 }
2043
2044 static int one_local_ref(const char *refname, const struct object_id *oid,
2045                          int flag, void *cb_data)
2046 {
2047         struct ref ***local_tail = cb_data;
2048         struct ref *ref;
2049
2050         /* we already know it starts with refs/ to get here */
2051         if (check_refname_format(refname + 5, 0))
2052                 return 0;
2053
2054         ref = alloc_ref(refname);
2055         oidcpy(&ref->new_oid, oid);
2056         **local_tail = ref;
2057         *local_tail = &ref->next;
2058         return 0;
2059 }
2060
2061 struct ref *get_local_heads(void)
2062 {
2063         struct ref *local_refs = NULL, **local_tail = &local_refs;
2064
2065         for_each_ref(one_local_ref, &local_tail);
2066         return local_refs;
2067 }
2068
2069 struct ref *guess_remote_head(const struct ref *head,
2070                               const struct ref *refs,
2071                               int all)
2072 {
2073         const struct ref *r;
2074         struct ref *list = NULL;
2075         struct ref **tail = &list;
2076
2077         if (!head)
2078                 return NULL;
2079
2080         /*
2081          * Some transports support directly peeking at
2082          * where HEAD points; if that is the case, then
2083          * we don't have to guess.
2084          */
2085         if (head->symref)
2086                 return copy_ref(find_ref_by_name(refs, head->symref));
2087
2088         /* If refs/heads/master could be right, it is. */
2089         if (!all) {
2090                 r = find_ref_by_name(refs, "refs/heads/master");
2091                 if (r && oideq(&r->old_oid, &head->old_oid))
2092                         return copy_ref(r);
2093         }
2094
2095         /* Look for another ref that points there */
2096         for (r = refs; r; r = r->next) {
2097                 if (r != head &&
2098                     starts_with(r->name, "refs/heads/") &&
2099                     oideq(&r->old_oid, &head->old_oid)) {
2100                         *tail = copy_ref(r);
2101                         tail = &((*tail)->next);
2102                         if (!all)
2103                                 break;
2104                 }
2105         }
2106
2107         return list;
2108 }
2109
2110 struct stale_heads_info {
2111         struct string_list *ref_names;
2112         struct ref **stale_refs_tail;
2113         struct refspec *rs;
2114 };
2115
2116 static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
2117                               int flags, void *cb_data)
2118 {
2119         struct stale_heads_info *info = cb_data;
2120         struct string_list matches = STRING_LIST_INIT_DUP;
2121         struct refspec_item query;
2122         int i, stale = 1;
2123         memset(&query, 0, sizeof(struct refspec_item));
2124         query.dst = (char *)refname;
2125
2126         query_refspecs_multiple(info->rs, &query, &matches);
2127         if (matches.nr == 0)
2128                 goto clean_exit; /* No matches */
2129
2130         /*
2131          * If we did find a suitable refspec and it's not a symref and
2132          * it's not in the list of refs that currently exist in that
2133          * remote, we consider it to be stale. In order to deal with
2134          * overlapping refspecs, we need to go over all of the
2135          * matching refs.
2136          */
2137         if (flags & REF_ISSYMREF)
2138                 goto clean_exit;
2139
2140         for (i = 0; stale && i < matches.nr; i++)
2141                 if (string_list_has_string(info->ref_names, matches.items[i].string))
2142                         stale = 0;
2143
2144         if (stale) {
2145                 struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
2146                 oidcpy(&ref->new_oid, oid);
2147         }
2148
2149 clean_exit:
2150         string_list_clear(&matches, 0);
2151         return 0;
2152 }
2153
2154 struct ref *get_stale_heads(struct refspec *rs, struct ref *fetch_map)
2155 {
2156         struct ref *ref, *stale_refs = NULL;
2157         struct string_list ref_names = STRING_LIST_INIT_NODUP;
2158         struct stale_heads_info info;
2159
2160         info.ref_names = &ref_names;
2161         info.stale_refs_tail = &stale_refs;
2162         info.rs = rs;
2163         for (ref = fetch_map; ref; ref = ref->next)
2164                 string_list_append(&ref_names, ref->name);
2165         string_list_sort(&ref_names);
2166         for_each_ref(get_stale_heads_cb, &info);
2167         string_list_clear(&ref_names, 0);
2168         return stale_refs;
2169 }
2170
2171 /*
2172  * Compare-and-swap
2173  */
2174 static void clear_cas_option(struct push_cas_option *cas)
2175 {
2176         int i;
2177
2178         for (i = 0; i < cas->nr; i++)
2179                 free(cas->entry[i].refname);
2180         free(cas->entry);
2181         memset(cas, 0, sizeof(*cas));
2182 }
2183
2184 static struct push_cas *add_cas_entry(struct push_cas_option *cas,
2185                                       const char *refname,
2186                                       size_t refnamelen)
2187 {
2188         struct push_cas *entry;
2189         ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
2190         entry = &cas->entry[cas->nr++];
2191         memset(entry, 0, sizeof(*entry));
2192         entry->refname = xmemdupz(refname, refnamelen);
2193         return entry;
2194 }
2195
2196 static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
2197 {
2198         const char *colon;
2199         struct push_cas *entry;
2200
2201         if (unset) {
2202                 /* "--no-<option>" */
2203                 clear_cas_option(cas);
2204                 return 0;
2205         }
2206
2207         if (!arg) {
2208                 /* just "--<option>" */
2209                 cas->use_tracking_for_rest = 1;
2210                 return 0;
2211         }
2212
2213         /* "--<option>=refname" or "--<option>=refname:value" */
2214         colon = strchrnul(arg, ':');
2215         entry = add_cas_entry(cas, arg, colon - arg);
2216         if (!*colon)
2217                 entry->use_tracking = 1;
2218         else if (!colon[1])
2219                 oidclr(&entry->expect);
2220         else if (get_oid(colon + 1, &entry->expect))
2221                 return error(_("cannot parse expected object name '%s'"),
2222                              colon + 1);
2223         return 0;
2224 }
2225
2226 int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
2227 {
2228         return parse_push_cas_option(opt->value, arg, unset);
2229 }
2230
2231 int is_empty_cas(const struct push_cas_option *cas)
2232 {
2233         return !cas->use_tracking_for_rest && !cas->nr;
2234 }
2235
2236 /*
2237  * Look at remote.fetch refspec and see if we have a remote
2238  * tracking branch for the refname there.  Fill its current
2239  * value in sha1[].
2240  * If we cannot do so, return negative to signal an error.
2241  */
2242 static int remote_tracking(struct remote *remote, const char *refname,
2243                            struct object_id *oid)
2244 {
2245         char *dst;
2246
2247         dst = apply_refspecs(&remote->fetch, refname);
2248         if (!dst)
2249                 return -1; /* no tracking ref for refname at remote */
2250         if (read_ref(dst, oid))
2251                 return -1; /* we know what the tracking ref is but we cannot read it */
2252         return 0;
2253 }
2254
2255 static void apply_cas(struct push_cas_option *cas,
2256                       struct remote *remote,
2257                       struct ref *ref)
2258 {
2259         int i;
2260
2261         /* Find an explicit --<option>=<name>[:<value>] entry */
2262         for (i = 0; i < cas->nr; i++) {
2263                 struct push_cas *entry = &cas->entry[i];
2264                 if (!refname_match(entry->refname, ref->name))
2265                         continue;
2266                 ref->expect_old_sha1 = 1;
2267                 if (!entry->use_tracking)
2268                         oidcpy(&ref->old_oid_expect, &entry->expect);
2269                 else if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2270                         oidclr(&ref->old_oid_expect);
2271                 return;
2272         }
2273
2274         /* Are we using "--<option>" to cover all? */
2275         if (!cas->use_tracking_for_rest)
2276                 return;
2277
2278         ref->expect_old_sha1 = 1;
2279         if (remote_tracking(remote, ref->name, &ref->old_oid_expect))
2280                 oidclr(&ref->old_oid_expect);
2281 }
2282
2283 void apply_push_cas(struct push_cas_option *cas,
2284                     struct remote *remote,
2285                     struct ref *remote_refs)
2286 {
2287         struct ref *ref;
2288         for (ref = remote_refs; ref; ref = ref->next)
2289                 apply_cas(cas, remote, ref);
2290 }