Correct handling of branch.$name.merge in builtin-fetch
[git] / remote.c
1 #include "cache.h"
2 #include "remote.h"
3 #include "refs.h"
4
5 static struct remote **remotes;
6 static int allocated_remotes;
7
8 static struct branch **branches;
9 static int allocated_branches;
10
11 static struct branch *current_branch;
12 static const char *default_remote_name;
13
14 #define BUF_SIZE (2048)
15 static char buffer[BUF_SIZE];
16
17 static void add_push_refspec(struct remote *remote, const char *ref)
18 {
19         int nr = remote->push_refspec_nr + 1;
20         remote->push_refspec =
21                 xrealloc(remote->push_refspec, nr * sizeof(char *));
22         remote->push_refspec[nr-1] = ref;
23         remote->push_refspec_nr = nr;
24 }
25
26 static void add_fetch_refspec(struct remote *remote, const char *ref)
27 {
28         int nr = remote->fetch_refspec_nr + 1;
29         remote->fetch_refspec =
30                 xrealloc(remote->fetch_refspec, nr * sizeof(char *));
31         remote->fetch_refspec[nr-1] = ref;
32         remote->fetch_refspec_nr = nr;
33 }
34
35 static void add_uri(struct remote *remote, const char *uri)
36 {
37         int nr = remote->uri_nr + 1;
38         remote->uri =
39                 xrealloc(remote->uri, nr * sizeof(char *));
40         remote->uri[nr-1] = uri;
41         remote->uri_nr = nr;
42 }
43
44 static struct remote *make_remote(const char *name, int len)
45 {
46         int i, empty = -1;
47
48         for (i = 0; i < allocated_remotes; i++) {
49                 if (!remotes[i]) {
50                         if (empty < 0)
51                                 empty = i;
52                 } else {
53                         if (len ? (!strncmp(name, remotes[i]->name, len) &&
54                                    !remotes[i]->name[len]) :
55                             !strcmp(name, remotes[i]->name))
56                                 return remotes[i];
57                 }
58         }
59
60         if (empty < 0) {
61                 empty = allocated_remotes;
62                 allocated_remotes += allocated_remotes ? allocated_remotes : 1;
63                 remotes = xrealloc(remotes,
64                                    sizeof(*remotes) * allocated_remotes);
65                 memset(remotes + empty, 0,
66                        (allocated_remotes - empty) * sizeof(*remotes));
67         }
68         remotes[empty] = xcalloc(1, sizeof(struct remote));
69         if (len)
70                 remotes[empty]->name = xstrndup(name, len);
71         else
72                 remotes[empty]->name = xstrdup(name);
73         return remotes[empty];
74 }
75
76 static void add_merge(struct branch *branch, const char *name)
77 {
78         int nr = branch->merge_nr + 1;
79         branch->merge_name =
80                 xrealloc(branch->merge_name, nr * sizeof(char *));
81         branch->merge_name[nr-1] = name;
82         branch->merge_nr = nr;
83 }
84
85 static struct branch *make_branch(const char *name, int len)
86 {
87         int i, empty = -1;
88         char *refname;
89
90         for (i = 0; i < allocated_branches; i++) {
91                 if (!branches[i]) {
92                         if (empty < 0)
93                                 empty = i;
94                 } else {
95                         if (len ? (!strncmp(name, branches[i]->name, len) &&
96                                    !branches[i]->name[len]) :
97                             !strcmp(name, branches[i]->name))
98                                 return branches[i];
99                 }
100         }
101
102         if (empty < 0) {
103                 empty = allocated_branches;
104                 allocated_branches += allocated_branches ? allocated_branches : 1;
105                 branches = xrealloc(branches,
106                                    sizeof(*branches) * allocated_branches);
107                 memset(branches + empty, 0,
108                        (allocated_branches - empty) * sizeof(*branches));
109         }
110         branches[empty] = xcalloc(1, sizeof(struct branch));
111         if (len)
112                 branches[empty]->name = xstrndup(name, len);
113         else
114                 branches[empty]->name = xstrdup(name);
115         refname = malloc(strlen(name) + strlen("refs/heads/") + 1);
116         strcpy(refname, "refs/heads/");
117         strcpy(refname + strlen("refs/heads/"),
118                branches[empty]->name);
119         branches[empty]->refname = refname;
120
121         return branches[empty];
122 }
123
124 static void read_remotes_file(struct remote *remote)
125 {
126         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
127
128         if (!f)
129                 return;
130         while (fgets(buffer, BUF_SIZE, f)) {
131                 int value_list;
132                 char *s, *p;
133
134                 if (!prefixcmp(buffer, "URL:")) {
135                         value_list = 0;
136                         s = buffer + 4;
137                 } else if (!prefixcmp(buffer, "Push:")) {
138                         value_list = 1;
139                         s = buffer + 5;
140                 } else if (!prefixcmp(buffer, "Pull:")) {
141                         value_list = 2;
142                         s = buffer + 5;
143                 } else
144                         continue;
145
146                 while (isspace(*s))
147                         s++;
148                 if (!*s)
149                         continue;
150
151                 p = s + strlen(s);
152                 while (isspace(p[-1]))
153                         *--p = 0;
154
155                 switch (value_list) {
156                 case 0:
157                         add_uri(remote, xstrdup(s));
158                         break;
159                 case 1:
160                         add_push_refspec(remote, xstrdup(s));
161                         break;
162                 case 2:
163                         add_fetch_refspec(remote, xstrdup(s));
164                         break;
165                 }
166         }
167         fclose(f);
168 }
169
170 static void read_branches_file(struct remote *remote)
171 {
172         const char *slash = strchr(remote->name, '/');
173         char *frag;
174         char *branch;
175         int n = slash ? slash - remote->name : 1000;
176         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
177         char *s, *p;
178         int len;
179
180         if (!f)
181                 return;
182         s = fgets(buffer, BUF_SIZE, f);
183         fclose(f);
184         if (!s)
185                 return;
186         while (isspace(*s))
187                 s++;
188         if (!*s)
189                 return;
190         p = s + strlen(s);
191         while (isspace(p[-1]))
192                 *--p = 0;
193         len = p - s;
194         if (slash)
195                 len += strlen(slash);
196         p = xmalloc(len + 1);
197         strcpy(p, s);
198         if (slash)
199                 strcat(p, slash);
200         frag = strchr(p, '#');
201         if (frag) {
202                 *(frag++) = '\0';
203                 branch = xmalloc(strlen(frag) + 12);
204                 strcpy(branch, "refs/heads/");
205                 strcat(branch, frag);
206         } else {
207                 branch = "refs/heads/master";
208         }
209         add_uri(remote, p);
210         add_fetch_refspec(remote, branch);
211         remote->fetch_tags = 1; /* always auto-follow */
212 }
213
214 static int handle_config(const char *key, const char *value)
215 {
216         const char *name;
217         const char *subkey;
218         struct remote *remote;
219         struct branch *branch;
220         if (!prefixcmp(key, "branch.")) {
221                 name = key + 7;
222                 subkey = strrchr(name, '.');
223                 branch = make_branch(name, subkey - name);
224                 if (!subkey)
225                         return 0;
226                 if (!value)
227                         return 0;
228                 if (!strcmp(subkey, ".remote")) {
229                         branch->remote_name = xstrdup(value);
230                         if (branch == current_branch)
231                                 default_remote_name = branch->remote_name;
232                 } else if (!strcmp(subkey, ".merge"))
233                         add_merge(branch, xstrdup(value));
234                 return 0;
235         }
236         if (prefixcmp(key,  "remote."))
237                 return 0;
238         name = key + 7;
239         subkey = strrchr(name, '.');
240         if (!subkey)
241                 return error("Config with no key for remote %s", name);
242         if (*subkey == '/') {
243                 warning("Config remote shorthand cannot begin with '/': %s", name);
244                 return 0;
245         }
246         remote = make_remote(name, subkey - name);
247         if (!value) {
248                 /* if we ever have a boolean variable, e.g. "remote.*.disabled"
249                  * [remote "frotz"]
250                  *      disabled
251                  * is a valid way to set it to true; we get NULL in value so
252                  * we need to handle it here.
253                  *
254                  * if (!strcmp(subkey, ".disabled")) {
255                  *      val = git_config_bool(key, value);
256                  *      return 0;
257                  * } else
258                  *
259                  */
260                 return 0; /* ignore unknown booleans */
261         }
262         if (!strcmp(subkey, ".url")) {
263                 add_uri(remote, xstrdup(value));
264         } else if (!strcmp(subkey, ".push")) {
265                 add_push_refspec(remote, xstrdup(value));
266         } else if (!strcmp(subkey, ".fetch")) {
267                 add_fetch_refspec(remote, xstrdup(value));
268         } else if (!strcmp(subkey, ".receivepack")) {
269                 if (!remote->receivepack)
270                         remote->receivepack = xstrdup(value);
271                 else
272                         error("more than one receivepack given, using the first");
273         } else if (!strcmp(subkey, ".uploadpack")) {
274                 if (!remote->uploadpack)
275                         remote->uploadpack = xstrdup(value);
276                 else
277                         error("more than one uploadpack given, using the first");
278         } else if (!strcmp(subkey, ".tagopt")) {
279                 if (!strcmp(value, "--no-tags"))
280                         remote->fetch_tags = -1;
281         }
282         return 0;
283 }
284
285 static void read_config(void)
286 {
287         unsigned char sha1[20];
288         const char *head_ref;
289         int flag;
290         if (default_remote_name) // did this already
291                 return;
292         default_remote_name = xstrdup("origin");
293         current_branch = NULL;
294         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
295         if (head_ref && (flag & REF_ISSYMREF) &&
296             !prefixcmp(head_ref, "refs/heads/")) {
297                 current_branch =
298                         make_branch(head_ref + strlen("refs/heads/"), 0);
299         }
300         git_config(handle_config);
301 }
302
303 struct refspec *parse_ref_spec(int nr_refspec, const char **refspec)
304 {
305         int i;
306         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
307         for (i = 0; i < nr_refspec; i++) {
308                 const char *sp, *ep, *gp;
309                 sp = refspec[i];
310                 if (*sp == '+') {
311                         rs[i].force = 1;
312                         sp++;
313                 }
314                 gp = strchr(sp, '*');
315                 ep = strchr(sp, ':');
316                 if (gp && ep && gp > ep)
317                         gp = NULL;
318                 if (ep) {
319                         if (ep[1]) {
320                                 const char *glob = strchr(ep + 1, '*');
321                                 if (!glob)
322                                         gp = NULL;
323                                 if (gp)
324                                         rs[i].dst = xstrndup(ep + 1,
325                                                              glob - ep - 1);
326                                 else
327                                         rs[i].dst = xstrdup(ep + 1);
328                         }
329                 } else {
330                         ep = sp + strlen(sp);
331                 }
332                 if (gp) {
333                         rs[i].pattern = 1;
334                         ep = gp;
335                 }
336                 rs[i].src = xstrndup(sp, ep - sp);
337         }
338         return rs;
339 }
340
341 struct remote *remote_get(const char *name)
342 {
343         struct remote *ret;
344
345         read_config();
346         if (!name)
347                 name = default_remote_name;
348         ret = make_remote(name, 0);
349         if (name[0] != '/') {
350                 if (!ret->uri)
351                         read_remotes_file(ret);
352                 if (!ret->uri)
353                         read_branches_file(ret);
354         }
355         if (!ret->uri)
356                 add_uri(ret, name);
357         if (!ret->uri)
358                 return NULL;
359         ret->fetch = parse_ref_spec(ret->fetch_refspec_nr, ret->fetch_refspec);
360         ret->push = parse_ref_spec(ret->push_refspec_nr, ret->push_refspec);
361         return ret;
362 }
363
364 int for_each_remote(each_remote_fn fn, void *priv)
365 {
366         int i, result = 0;
367         read_config();
368         for (i = 0; i < allocated_remotes && !result; i++) {
369                 struct remote *r = remotes[i];
370                 if (!r)
371                         continue;
372                 if (!r->fetch)
373                         r->fetch = parse_ref_spec(r->fetch_refspec_nr,
374                                         r->fetch_refspec);
375                 if (!r->push)
376                         r->push = parse_ref_spec(r->push_refspec_nr,
377                                         r->push_refspec);
378                 result = fn(r, priv);
379         }
380         return result;
381 }
382
383 int remote_has_uri(struct remote *remote, const char *uri)
384 {
385         int i;
386         for (i = 0; i < remote->uri_nr; i++) {
387                 if (!strcmp(remote->uri[i], uri))
388                         return 1;
389         }
390         return 0;
391 }
392
393 /*
394  * Returns true if, under the matching rules for fetching, name is the
395  * same as the given full name.
396  */
397 static int ref_matches_abbrev(const char *name, const char *full)
398 {
399         if (!prefixcmp(name, "refs/") || !strcmp(name, "HEAD"))
400                 return !strcmp(name, full);
401         if (prefixcmp(full, "refs/"))
402                 return 0;
403         if (!prefixcmp(name, "heads/") ||
404             !prefixcmp(name, "tags/") ||
405             !prefixcmp(name, "remotes/"))
406                 return !strcmp(name, full + 5);
407         if (prefixcmp(full + 5, "heads/"))
408                 return 0;
409         return !strcmp(full + 11, name);
410 }
411
412 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
413 {
414         int find_src = refspec->src == NULL;
415         char *needle, **result;
416         int i;
417
418         if (find_src) {
419                 if (refspec->dst == NULL)
420                         return error("find_tracking: need either src or dst");
421                 needle = refspec->dst;
422                 result = &refspec->src;
423         } else {
424                 needle = refspec->src;
425                 result = &refspec->dst;
426         }
427
428         for (i = 0; i < remote->fetch_refspec_nr; i++) {
429                 struct refspec *fetch = &remote->fetch[i];
430                 const char *key = find_src ? fetch->dst : fetch->src;
431                 const char *value = find_src ? fetch->src : fetch->dst;
432                 if (!fetch->dst)
433                         continue;
434                 if (fetch->pattern) {
435                         if (!prefixcmp(needle, key)) {
436                                 *result = xmalloc(strlen(value) +
437                                                   strlen(needle) -
438                                                   strlen(key) + 1);
439                                 strcpy(*result, value);
440                                 strcpy(*result + strlen(value),
441                                        needle + strlen(key));
442                                 refspec->force = fetch->force;
443                                 return 0;
444                         }
445                 } else if (!strcmp(needle, key)) {
446                         *result = xstrdup(value);
447                         refspec->force = fetch->force;
448                         return 0;
449                 }
450         }
451         return -1;
452 }
453
454 struct ref *alloc_ref(unsigned namelen)
455 {
456         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
457         memset(ret, 0, sizeof(struct ref) + namelen);
458         return ret;
459 }
460
461 static struct ref *copy_ref(struct ref *ref)
462 {
463         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
464         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
465         ret->next = NULL;
466         return ret;
467 }
468
469 void free_refs(struct ref *ref)
470 {
471         struct ref *next;
472         while (ref) {
473                 next = ref->next;
474                 if (ref->peer_ref)
475                         free(ref->peer_ref);
476                 free(ref);
477                 ref = next;
478         }
479 }
480
481 static int count_refspec_match(const char *pattern,
482                                struct ref *refs,
483                                struct ref **matched_ref)
484 {
485         int patlen = strlen(pattern);
486         struct ref *matched_weak = NULL;
487         struct ref *matched = NULL;
488         int weak_match = 0;
489         int match = 0;
490
491         for (weak_match = match = 0; refs; refs = refs->next) {
492                 char *name = refs->name;
493                 int namelen = strlen(name);
494
495                 if (namelen < patlen ||
496                     memcmp(name + namelen - patlen, pattern, patlen))
497                         continue;
498                 if (namelen != patlen && name[namelen - patlen - 1] != '/')
499                         continue;
500
501                 /* A match is "weak" if it is with refs outside
502                  * heads or tags, and did not specify the pattern
503                  * in full (e.g. "refs/remotes/origin/master") or at
504                  * least from the toplevel (e.g. "remotes/origin/master");
505                  * otherwise "git push $URL master" would result in
506                  * ambiguity between remotes/origin/master and heads/master
507                  * at the remote site.
508                  */
509                 if (namelen != patlen &&
510                     patlen != namelen - 5 &&
511                     prefixcmp(name, "refs/heads/") &&
512                     prefixcmp(name, "refs/tags/")) {
513                         /* We want to catch the case where only weak
514                          * matches are found and there are multiple
515                          * matches, and where more than one strong
516                          * matches are found, as ambiguous.  One
517                          * strong match with zero or more weak matches
518                          * are acceptable as a unique match.
519                          */
520                         matched_weak = refs;
521                         weak_match++;
522                 }
523                 else {
524                         matched = refs;
525                         match++;
526                 }
527         }
528         if (!matched) {
529                 *matched_ref = matched_weak;
530                 return weak_match;
531         }
532         else {
533                 *matched_ref = matched;
534                 return match;
535         }
536 }
537
538 static void tail_link_ref(struct ref *ref, struct ref ***tail)
539 {
540         **tail = ref;
541         while (ref->next)
542                 ref = ref->next;
543         *tail = &ref->next;
544 }
545
546 static struct ref *try_explicit_object_name(const char *name)
547 {
548         unsigned char sha1[20];
549         struct ref *ref;
550         int len;
551
552         if (!*name) {
553                 ref = alloc_ref(20);
554                 strcpy(ref->name, "(delete)");
555                 hashclr(ref->new_sha1);
556                 return ref;
557         }
558         if (get_sha1(name, sha1))
559                 return NULL;
560         len = strlen(name) + 1;
561         ref = alloc_ref(len);
562         memcpy(ref->name, name, len);
563         hashcpy(ref->new_sha1, sha1);
564         return ref;
565 }
566
567 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
568 {
569         struct ref *ret;
570         size_t len;
571
572         len = strlen(name) + 1;
573         ret = alloc_ref(len);
574         memcpy(ret->name, name, len);
575         tail_link_ref(ret, tail);
576         return ret;
577 }
578
579 static int match_explicit(struct ref *src, struct ref *dst,
580                           struct ref ***dst_tail,
581                           struct refspec *rs,
582                           int errs)
583 {
584         struct ref *matched_src, *matched_dst;
585
586         const char *dst_value = rs->dst;
587
588         if (rs->pattern)
589                 return errs;
590
591         matched_src = matched_dst = NULL;
592         switch (count_refspec_match(rs->src, src, &matched_src)) {
593         case 1:
594                 break;
595         case 0:
596                 /* The source could be in the get_sha1() format
597                  * not a reference name.  :refs/other is a
598                  * way to delete 'other' ref at the remote end.
599                  */
600                 matched_src = try_explicit_object_name(rs->src);
601                 if (matched_src)
602                         break;
603                 error("src refspec %s does not match any.",
604                       rs->src);
605                 break;
606         default:
607                 matched_src = NULL;
608                 error("src refspec %s matches more than one.",
609                       rs->src);
610                 break;
611         }
612
613         if (!matched_src)
614                 errs = 1;
615
616         if (dst_value == NULL)
617                 dst_value = matched_src->name;
618
619         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
620         case 1:
621                 break;
622         case 0:
623                 if (!memcmp(dst_value, "refs/", 5))
624                         matched_dst = make_linked_ref(dst_value, dst_tail);
625                 else
626                         error("dst refspec %s does not match any "
627                               "existing ref on the remote and does "
628                               "not start with refs/.", dst_value);
629                 break;
630         default:
631                 matched_dst = NULL;
632                 error("dst refspec %s matches more than one.",
633                       dst_value);
634                 break;
635         }
636         if (errs || matched_dst == NULL)
637                 return 1;
638         if (matched_dst->peer_ref) {
639                 errs = 1;
640                 error("dst ref %s receives from more than one src.",
641                       matched_dst->name);
642         }
643         else {
644                 matched_dst->peer_ref = matched_src;
645                 matched_dst->force = rs->force;
646         }
647         return errs;
648 }
649
650 static int match_explicit_refs(struct ref *src, struct ref *dst,
651                                struct ref ***dst_tail, struct refspec *rs,
652                                int rs_nr)
653 {
654         int i, errs;
655         for (i = errs = 0; i < rs_nr; i++)
656                 errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
657         return -errs;
658 }
659
660 static struct ref *find_ref_by_name(struct ref *list, const char *name)
661 {
662         for ( ; list; list = list->next)
663                 if (!strcmp(list->name, name))
664                         return list;
665         return NULL;
666 }
667
668 static const struct refspec *check_pattern_match(const struct refspec *rs,
669                                                  int rs_nr,
670                                                  const struct ref *src)
671 {
672         int i;
673         for (i = 0; i < rs_nr; i++) {
674                 if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
675                         return rs + i;
676         }
677         return NULL;
678 }
679
680 /*
681  * Note. This is used only by "push"; refspec matching rules for
682  * push and fetch are subtly different, so do not try to reuse it
683  * without thinking.
684  */
685 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
686                int nr_refspec, char **refspec, int all)
687 {
688         struct refspec *rs =
689                 parse_ref_spec(nr_refspec, (const char **) refspec);
690
691         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
692                 return -1;
693
694         /* pick the remainder */
695         for ( ; src; src = src->next) {
696                 struct ref *dst_peer;
697                 const struct refspec *pat = NULL;
698                 char *dst_name;
699                 if (src->peer_ref)
700                         continue;
701                 if (nr_refspec) {
702                         pat = check_pattern_match(rs, nr_refspec, src);
703                         if (!pat)
704                                 continue;
705                 }
706                 else if (prefixcmp(src->name, "refs/heads/"))
707                         /*
708                          * "matching refs"; traditionally we pushed everything
709                          * including refs outside refs/heads/ hierarchy, but
710                          * that does not make much sense these days.
711                          */
712                         continue;
713
714                 if (pat) {
715                         const char *dst_side = pat->dst ? pat->dst : pat->src;
716                         dst_name = xmalloc(strlen(dst_side) +
717                                            strlen(src->name) -
718                                            strlen(pat->src) + 2);
719                         strcpy(dst_name, dst_side);
720                         strcat(dst_name, src->name + strlen(pat->src));
721                 } else
722                         dst_name = xstrdup(src->name);
723                 dst_peer = find_ref_by_name(dst, dst_name);
724                 if (dst_peer && dst_peer->peer_ref)
725                         /* We're already sending something to this ref. */
726                         goto free_name;
727                 if (!dst_peer && !nr_refspec && !all)
728                         /* Remote doesn't have it, and we have no
729                          * explicit pattern, and we don't have
730                          * --all. */
731                         goto free_name;
732                 if (!dst_peer) {
733                         /* Create a new one and link it */
734                         dst_peer = make_linked_ref(dst_name, dst_tail);
735                         hashcpy(dst_peer->new_sha1, src->new_sha1);
736                 }
737                 dst_peer->peer_ref = src;
738         free_name:
739                 free(dst_name);
740         }
741         return 0;
742 }
743
744 struct branch *branch_get(const char *name)
745 {
746         struct branch *ret;
747
748         read_config();
749         if (!name || !*name || !strcmp(name, "HEAD"))
750                 ret = current_branch;
751         else
752                 ret = make_branch(name, 0);
753         if (ret && ret->remote_name) {
754                 ret->remote = remote_get(ret->remote_name);
755                 if (ret->merge_nr) {
756                         int i;
757                         ret->merge = xcalloc(sizeof(*ret->merge),
758                                              ret->merge_nr);
759                         for (i = 0; i < ret->merge_nr; i++) {
760                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
761                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
762                                 remote_find_tracking(ret->remote,
763                                                      ret->merge[i]);
764                         }
765                 }
766         }
767         return ret;
768 }
769
770 int branch_has_merge_config(struct branch *branch)
771 {
772         return branch && !!branch->merge;
773 }
774
775 int branch_merge_matches(struct branch *branch,
776                                  int i,
777                                  const char *refname)
778 {
779         if (!branch || i < 0 || i >= branch->merge_nr)
780                 return 0;
781         return ref_matches_abbrev(branch->merge[i]->src, refname);
782 }
783
784 static struct ref *get_expanded_map(struct ref *remote_refs,
785                                     const struct refspec *refspec)
786 {
787         struct ref *ref;
788         struct ref *ret = NULL;
789         struct ref **tail = &ret;
790
791         int remote_prefix_len = strlen(refspec->src);
792         int local_prefix_len = strlen(refspec->dst);
793
794         for (ref = remote_refs; ref; ref = ref->next) {
795                 if (strchr(ref->name, '^'))
796                         continue; /* a dereference item */
797                 if (!prefixcmp(ref->name, refspec->src)) {
798                         char *match;
799                         struct ref *cpy = copy_ref(ref);
800                         match = ref->name + remote_prefix_len;
801
802                         cpy->peer_ref = alloc_ref(local_prefix_len +
803                                                   strlen(match) + 1);
804                         sprintf(cpy->peer_ref->name, "%s%s",
805                                 refspec->dst, match);
806                         if (refspec->force)
807                                 cpy->peer_ref->force = 1;
808                         *tail = cpy;
809                         tail = &cpy->next;
810                 }
811         }
812
813         return ret;
814 }
815
816 static struct ref *find_ref_by_name_abbrev(struct ref *refs, const char *name)
817 {
818         struct ref *ref;
819         for (ref = refs; ref; ref = ref->next) {
820                 if (ref_matches_abbrev(name, ref->name))
821                         return ref;
822         }
823         return NULL;
824 }
825
826 struct ref *get_remote_ref(struct ref *remote_refs, const char *name)
827 {
828         struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
829
830         if (!ref)
831                 die("Couldn't find remote ref %s\n", name);
832
833         return copy_ref(ref);
834 }
835
836 static struct ref *get_local_ref(const char *name)
837 {
838         struct ref *ret;
839         if (!name)
840                 return NULL;
841
842         if (!prefixcmp(name, "refs/")) {
843                 ret = alloc_ref(strlen(name) + 1);
844                 strcpy(ret->name, name);
845                 return ret;
846         }
847
848         if (!prefixcmp(name, "heads/") ||
849             !prefixcmp(name, "tags/") ||
850             !prefixcmp(name, "remotes/")) {
851                 ret = alloc_ref(strlen(name) + 6);
852                 sprintf(ret->name, "refs/%s", name);
853                 return ret;
854         }
855
856         ret = alloc_ref(strlen(name) + 12);
857         sprintf(ret->name, "refs/heads/%s", name);
858         return ret;
859 }
860
861 int get_fetch_map(struct ref *remote_refs,
862                   const struct refspec *refspec,
863                   struct ref ***tail)
864 {
865         struct ref *ref_map, *rm;
866
867         if (refspec->pattern) {
868                 ref_map = get_expanded_map(remote_refs, refspec);
869         } else {
870                 ref_map = get_remote_ref(remote_refs,
871                                          refspec->src[0] ?
872                                          refspec->src : "HEAD");
873
874                 ref_map->peer_ref = get_local_ref(refspec->dst);
875                 if (ref_map->peer_ref && refspec->force)
876                         ref_map->peer_ref->force = 1;
877         }
878
879         for (rm = ref_map; rm; rm = rm->next) {
880                 if (rm->peer_ref && check_ref_format(rm->peer_ref->name + 5))
881                         die("* refusing to create funny ref '%s' locally",
882                             rm->peer_ref->name);
883         }
884
885         tail_link_ref(ref_map, tail);
886
887         return 0;
888 }