Tighten refspec processing
[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_url(struct remote *remote, const char *url)
36 {
37         int nr = remote->url_nr + 1;
38         remote->url =
39                 xrealloc(remote->url, nr * sizeof(char *));
40         remote->url[nr-1] = url;
41         remote->url_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_url(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_url(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                 if (!subkey)
224                         return 0;
225                 branch = make_branch(name, subkey - name);
226                 if (!strcmp(subkey, ".remote")) {
227                         if (!value)
228                                 return config_error_nonbool(key);
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                         if (!value)
234                                 return config_error_nonbool(key);
235                         add_merge(branch, xstrdup(value));
236                 }
237                 return 0;
238         }
239         if (prefixcmp(key,  "remote."))
240                 return 0;
241         name = key + 7;
242         subkey = strrchr(name, '.');
243         if (!subkey)
244                 return error("Config with no key for remote %s", name);
245         if (*subkey == '/') {
246                 warning("Config remote shorthand cannot begin with '/': %s", name);
247                 return 0;
248         }
249         remote = make_remote(name, subkey - name);
250         if (!value) {
251                 /* if we ever have a boolean variable, e.g. "remote.*.disabled"
252                  * [remote "frotz"]
253                  *      disabled
254                  * is a valid way to set it to true; we get NULL in value so
255                  * we need to handle it here.
256                  *
257                  * if (!strcmp(subkey, ".disabled")) {
258                  *      val = git_config_bool(key, value);
259                  *      return 0;
260                  * } else
261                  *
262                  */
263                 return 0; /* ignore unknown booleans */
264         }
265         if (!strcmp(subkey, ".url")) {
266                 add_url(remote, xstrdup(value));
267         } else if (!strcmp(subkey, ".push")) {
268                 add_push_refspec(remote, xstrdup(value));
269         } else if (!strcmp(subkey, ".fetch")) {
270                 add_fetch_refspec(remote, xstrdup(value));
271         } else if (!strcmp(subkey, ".receivepack")) {
272                 if (!remote->receivepack)
273                         remote->receivepack = xstrdup(value);
274                 else
275                         error("more than one receivepack given, using the first");
276         } else if (!strcmp(subkey, ".uploadpack")) {
277                 if (!remote->uploadpack)
278                         remote->uploadpack = xstrdup(value);
279                 else
280                         error("more than one uploadpack given, using the first");
281         } else if (!strcmp(subkey, ".tagopt")) {
282                 if (!strcmp(value, "--no-tags"))
283                         remote->fetch_tags = -1;
284         } else if (!strcmp(subkey, ".proxy")) {
285                 remote->http_proxy = xstrdup(value);
286         }
287         return 0;
288 }
289
290 static void read_config(void)
291 {
292         unsigned char sha1[20];
293         const char *head_ref;
294         int flag;
295         if (default_remote_name) // did this already
296                 return;
297         default_remote_name = xstrdup("origin");
298         current_branch = NULL;
299         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
300         if (head_ref && (flag & REF_ISSYMREF) &&
301             !prefixcmp(head_ref, "refs/heads/")) {
302                 current_branch =
303                         make_branch(head_ref + strlen("refs/heads/"), 0);
304         }
305         git_config(handle_config);
306 }
307
308 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch)
309 {
310         int i;
311         int st;
312         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
313
314         for (i = 0; i < nr_refspec; i++) {
315                 size_t llen, rlen;
316                 int is_glob;
317                 const char *lhs, *rhs;
318
319                 llen = rlen = is_glob = 0;
320
321                 lhs = refspec[i];
322                 if (*lhs == '+') {
323                         rs[i].force = 1;
324                         lhs++;
325                 }
326
327                 rhs = strrchr(lhs, ':');
328                 if (rhs) {
329                         rhs++;
330                         rlen = strlen(rhs);
331                         is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
332                         if (is_glob)
333                                 rlen -= 2;
334                         rs[i].dst = xstrndup(rhs, rlen);
335                 }
336
337                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
338                 if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
339                         if ((rhs && !is_glob) || (!rhs && fetch))
340                                 goto invalid;
341                         is_glob = 1;
342                         llen -= 2;
343                 } else if (rhs && is_glob) {
344                         goto invalid;
345                 }
346
347                 rs[i].pattern = is_glob;
348                 rs[i].src = xstrndup(lhs, llen);
349
350                 if (fetch) {
351                         /*
352                          * LHS
353                          * - empty is allowed; it means HEAD.
354                          * - otherwise it must be a valid looking ref.
355                          */
356                         if (!*rs[i].src)
357                                 ; /* empty is ok */
358                         else {
359                                 st = check_ref_format(rs[i].src);
360                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
361                                         goto invalid;
362                         }
363                         /*
364                          * RHS
365                          * - missing is ok, and is same as empty.
366                          * - empty is ok; it means not to store.
367                          * - otherwise it must be a valid looking ref.
368                          */
369                         if (!rs[i].dst) {
370                                 ; /* ok */
371                         } else if (!*rs[i].dst) {
372                                 ; /* ok */
373                         } else {
374                                 st = check_ref_format(rs[i].dst);
375                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
376                                         goto invalid;
377                         }
378                 } else {
379                         /*
380                          * LHS
381                          * - empty is allowed; it means delete.
382                          * - when wildcarded, it must be a valid looking ref.
383                          * - otherwise, it must be an extended SHA-1, but
384                          *   there is no existing way to validate this.
385                          */
386                         if (!*rs[i].src)
387                                 ; /* empty is ok */
388                         else if (is_glob) {
389                                 st = check_ref_format(rs[i].src);
390                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
391                                         goto invalid;
392                         }
393                         else
394                                 ; /* anything goes, for now */
395                         /*
396                          * RHS
397                          * - missing is allowed, but LHS then must be a
398                          *   valid looking ref.
399                          * - empty is not allowed.
400                          * - otherwise it must be a valid looking ref.
401                          */
402                         if (!rs[i].dst) {
403                                 st = check_ref_format(rs[i].src);
404                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
405                                         goto invalid;
406                         } else if (!*rs[i].dst) {
407                                 goto invalid;
408                         } else {
409                                 st = check_ref_format(rs[i].dst);
410                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
411                                         goto invalid;
412                         }
413                 }
414         }
415         return rs;
416
417  invalid:
418         die("Invalid refspec '%s'", refspec[i]);
419 }
420
421 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
422 {
423         return parse_refspec_internal(nr_refspec, refspec, 1);
424 }
425
426 struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
427 {
428         return parse_refspec_internal(nr_refspec, refspec, 0);
429 }
430
431 static int valid_remote_nick(const char *name)
432 {
433         if (!name[0] || /* not empty */
434             (name[0] == '.' && /* not "." */
435              (!name[1] || /* not ".." */
436               (name[1] == '.' && !name[2]))))
437                 return 0;
438         return !strchr(name, '/'); /* no slash */
439 }
440
441 struct remote *remote_get(const char *name)
442 {
443         struct remote *ret;
444
445         read_config();
446         if (!name)
447                 name = default_remote_name;
448         ret = make_remote(name, 0);
449         if (valid_remote_nick(name)) {
450                 if (!ret->url)
451                         read_remotes_file(ret);
452                 if (!ret->url)
453                         read_branches_file(ret);
454         }
455         if (!ret->url)
456                 add_url(ret, name);
457         if (!ret->url)
458                 return NULL;
459         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
460         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
461         return ret;
462 }
463
464 int for_each_remote(each_remote_fn fn, void *priv)
465 {
466         int i, result = 0;
467         read_config();
468         for (i = 0; i < allocated_remotes && !result; i++) {
469                 struct remote *r = remotes[i];
470                 if (!r)
471                         continue;
472                 if (!r->fetch)
473                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
474                                                        r->fetch_refspec);
475                 if (!r->push)
476                         r->push = parse_push_refspec(r->push_refspec_nr,
477                                                      r->push_refspec);
478                 result = fn(r, priv);
479         }
480         return result;
481 }
482
483 void ref_remove_duplicates(struct ref *ref_map)
484 {
485         struct ref **posn;
486         struct ref *next;
487         for (; ref_map; ref_map = ref_map->next) {
488                 if (!ref_map->peer_ref)
489                         continue;
490                 posn = &ref_map->next;
491                 while (*posn) {
492                         if ((*posn)->peer_ref &&
493                             !strcmp((*posn)->peer_ref->name,
494                                     ref_map->peer_ref->name)) {
495                                 if (strcmp((*posn)->name, ref_map->name))
496                                         die("%s tracks both %s and %s",
497                                             ref_map->peer_ref->name,
498                                             (*posn)->name, ref_map->name);
499                                 next = (*posn)->next;
500                                 free((*posn)->peer_ref);
501                                 free(*posn);
502                                 *posn = next;
503                         } else {
504                                 posn = &(*posn)->next;
505                         }
506                 }
507         }
508 }
509
510 int remote_has_url(struct remote *remote, const char *url)
511 {
512         int i;
513         for (i = 0; i < remote->url_nr; i++) {
514                 if (!strcmp(remote->url[i], url))
515                         return 1;
516         }
517         return 0;
518 }
519
520 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
521 {
522         int find_src = refspec->src == NULL;
523         char *needle, **result;
524         int i;
525
526         if (find_src) {
527                 if (!refspec->dst)
528                         return error("find_tracking: need either src or dst");
529                 needle = refspec->dst;
530                 result = &refspec->src;
531         } else {
532                 needle = refspec->src;
533                 result = &refspec->dst;
534         }
535
536         for (i = 0; i < remote->fetch_refspec_nr; i++) {
537                 struct refspec *fetch = &remote->fetch[i];
538                 const char *key = find_src ? fetch->dst : fetch->src;
539                 const char *value = find_src ? fetch->src : fetch->dst;
540                 if (!fetch->dst)
541                         continue;
542                 if (fetch->pattern) {
543                         if (!prefixcmp(needle, key) &&
544                             needle[strlen(key)] == '/') {
545                                 *result = xmalloc(strlen(value) +
546                                                   strlen(needle) -
547                                                   strlen(key) + 1);
548                                 strcpy(*result, value);
549                                 strcpy(*result + strlen(value),
550                                        needle + strlen(key));
551                                 refspec->force = fetch->force;
552                                 return 0;
553                         }
554                 } else if (!strcmp(needle, key)) {
555                         *result = xstrdup(value);
556                         refspec->force = fetch->force;
557                         return 0;
558                 }
559         }
560         return -1;
561 }
562
563 struct ref *alloc_ref(unsigned namelen)
564 {
565         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
566         memset(ret, 0, sizeof(struct ref) + namelen);
567         return ret;
568 }
569
570 static struct ref *copy_ref(const struct ref *ref)
571 {
572         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
573         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
574         ret->next = NULL;
575         return ret;
576 }
577
578 struct ref *copy_ref_list(const struct ref *ref)
579 {
580         struct ref *ret = NULL;
581         struct ref **tail = &ret;
582         while (ref) {
583                 *tail = copy_ref(ref);
584                 ref = ref->next;
585                 tail = &((*tail)->next);
586         }
587         return ret;
588 }
589
590 void free_refs(struct ref *ref)
591 {
592         struct ref *next;
593         while (ref) {
594                 next = ref->next;
595                 if (ref->peer_ref)
596                         free(ref->peer_ref);
597                 free(ref);
598                 ref = next;
599         }
600 }
601
602 static int count_refspec_match(const char *pattern,
603                                struct ref *refs,
604                                struct ref **matched_ref)
605 {
606         int patlen = strlen(pattern);
607         struct ref *matched_weak = NULL;
608         struct ref *matched = NULL;
609         int weak_match = 0;
610         int match = 0;
611
612         for (weak_match = match = 0; refs; refs = refs->next) {
613                 char *name = refs->name;
614                 int namelen = strlen(name);
615
616                 if (!refname_match(pattern, name, ref_rev_parse_rules))
617                         continue;
618
619                 /* A match is "weak" if it is with refs outside
620                  * heads or tags, and did not specify the pattern
621                  * in full (e.g. "refs/remotes/origin/master") or at
622                  * least from the toplevel (e.g. "remotes/origin/master");
623                  * otherwise "git push $URL master" would result in
624                  * ambiguity between remotes/origin/master and heads/master
625                  * at the remote site.
626                  */
627                 if (namelen != patlen &&
628                     patlen != namelen - 5 &&
629                     prefixcmp(name, "refs/heads/") &&
630                     prefixcmp(name, "refs/tags/")) {
631                         /* We want to catch the case where only weak
632                          * matches are found and there are multiple
633                          * matches, and where more than one strong
634                          * matches are found, as ambiguous.  One
635                          * strong match with zero or more weak matches
636                          * are acceptable as a unique match.
637                          */
638                         matched_weak = refs;
639                         weak_match++;
640                 }
641                 else {
642                         matched = refs;
643                         match++;
644                 }
645         }
646         if (!matched) {
647                 *matched_ref = matched_weak;
648                 return weak_match;
649         }
650         else {
651                 *matched_ref = matched;
652                 return match;
653         }
654 }
655
656 static void tail_link_ref(struct ref *ref, struct ref ***tail)
657 {
658         **tail = ref;
659         while (ref->next)
660                 ref = ref->next;
661         *tail = &ref->next;
662 }
663
664 static struct ref *try_explicit_object_name(const char *name)
665 {
666         unsigned char sha1[20];
667         struct ref *ref;
668         int len;
669
670         if (!*name) {
671                 ref = alloc_ref(20);
672                 strcpy(ref->name, "(delete)");
673                 hashclr(ref->new_sha1);
674                 return ref;
675         }
676         if (get_sha1(name, sha1))
677                 return NULL;
678         len = strlen(name) + 1;
679         ref = alloc_ref(len);
680         memcpy(ref->name, name, len);
681         hashcpy(ref->new_sha1, sha1);
682         return ref;
683 }
684
685 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
686 {
687         struct ref *ret;
688         size_t len;
689
690         len = strlen(name) + 1;
691         ret = alloc_ref(len);
692         memcpy(ret->name, name, len);
693         tail_link_ref(ret, tail);
694         return ret;
695 }
696
697 static int match_explicit(struct ref *src, struct ref *dst,
698                           struct ref ***dst_tail,
699                           struct refspec *rs,
700                           int errs)
701 {
702         struct ref *matched_src, *matched_dst;
703
704         const char *dst_value = rs->dst;
705
706         if (rs->pattern)
707                 return errs;
708
709         matched_src = matched_dst = NULL;
710         switch (count_refspec_match(rs->src, src, &matched_src)) {
711         case 1:
712                 break;
713         case 0:
714                 /* The source could be in the get_sha1() format
715                  * not a reference name.  :refs/other is a
716                  * way to delete 'other' ref at the remote end.
717                  */
718                 matched_src = try_explicit_object_name(rs->src);
719                 if (!matched_src)
720                         error("src refspec %s does not match any.", rs->src);
721                 break;
722         default:
723                 matched_src = NULL;
724                 error("src refspec %s matches more than one.", rs->src);
725                 break;
726         }
727
728         if (!matched_src)
729                 errs = 1;
730
731         if (!dst_value) {
732                 if (!matched_src)
733                         return errs;
734                 dst_value = matched_src->name;
735         }
736
737         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
738         case 1:
739                 break;
740         case 0:
741                 if (!memcmp(dst_value, "refs/", 5))
742                         matched_dst = make_linked_ref(dst_value, dst_tail);
743                 else
744                         error("dst refspec %s does not match any "
745                               "existing ref on the remote and does "
746                               "not start with refs/.", dst_value);
747                 break;
748         default:
749                 matched_dst = NULL;
750                 error("dst refspec %s matches more than one.",
751                       dst_value);
752                 break;
753         }
754         if (errs || !matched_dst)
755                 return 1;
756         if (matched_dst->peer_ref) {
757                 errs = 1;
758                 error("dst ref %s receives from more than one src.",
759                       matched_dst->name);
760         }
761         else {
762                 matched_dst->peer_ref = matched_src;
763                 matched_dst->force = rs->force;
764         }
765         return errs;
766 }
767
768 static int match_explicit_refs(struct ref *src, struct ref *dst,
769                                struct ref ***dst_tail, struct refspec *rs,
770                                int rs_nr)
771 {
772         int i, errs;
773         for (i = errs = 0; i < rs_nr; i++)
774                 errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
775         return -errs;
776 }
777
778 static const struct refspec *check_pattern_match(const struct refspec *rs,
779                                                  int rs_nr,
780                                                  const struct ref *src)
781 {
782         int i;
783         for (i = 0; i < rs_nr; i++) {
784                 if (rs[i].pattern &&
785                     !prefixcmp(src->name, rs[i].src) &&
786                     src->name[strlen(rs[i].src)] == '/')
787                         return rs + i;
788         }
789         return NULL;
790 }
791
792 /*
793  * Note. This is used only by "push"; refspec matching rules for
794  * push and fetch are subtly different, so do not try to reuse it
795  * without thinking.
796  */
797 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
798                int nr_refspec, const char **refspec, int flags)
799 {
800         struct refspec *rs =
801                 parse_push_refspec(nr_refspec, (const char **) refspec);
802         int send_all = flags & MATCH_REFS_ALL;
803         int send_mirror = flags & MATCH_REFS_MIRROR;
804
805         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
806                 return -1;
807
808         /* pick the remainder */
809         for ( ; src; src = src->next) {
810                 struct ref *dst_peer;
811                 const struct refspec *pat = NULL;
812                 char *dst_name;
813                 if (src->peer_ref)
814                         continue;
815                 if (nr_refspec) {
816                         pat = check_pattern_match(rs, nr_refspec, src);
817                         if (!pat)
818                                 continue;
819                 }
820                 else if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
821                         /*
822                          * "matching refs"; traditionally we pushed everything
823                          * including refs outside refs/heads/ hierarchy, but
824                          * that does not make much sense these days.
825                          */
826                         continue;
827
828                 if (pat) {
829                         const char *dst_side = pat->dst ? pat->dst : pat->src;
830                         dst_name = xmalloc(strlen(dst_side) +
831                                            strlen(src->name) -
832                                            strlen(pat->src) + 2);
833                         strcpy(dst_name, dst_side);
834                         strcat(dst_name, src->name + strlen(pat->src));
835                 } else
836                         dst_name = xstrdup(src->name);
837                 dst_peer = find_ref_by_name(dst, dst_name);
838                 if (dst_peer && dst_peer->peer_ref)
839                         /* We're already sending something to this ref. */
840                         goto free_name;
841
842                 if (!dst_peer && !nr_refspec && !(send_all || send_mirror))
843                         /*
844                          * Remote doesn't have it, and we have no
845                          * explicit pattern, and we don't have
846                          * --all nor --mirror.
847                          */
848                         goto free_name;
849                 if (!dst_peer) {
850                         /* Create a new one and link it */
851                         dst_peer = make_linked_ref(dst_name, dst_tail);
852                         hashcpy(dst_peer->new_sha1, src->new_sha1);
853                 }
854                 dst_peer->peer_ref = src;
855                 if (pat)
856                         dst_peer->force = pat->force;
857         free_name:
858                 free(dst_name);
859         }
860         return 0;
861 }
862
863 struct branch *branch_get(const char *name)
864 {
865         struct branch *ret;
866
867         read_config();
868         if (!name || !*name || !strcmp(name, "HEAD"))
869                 ret = current_branch;
870         else
871                 ret = make_branch(name, 0);
872         if (ret && ret->remote_name) {
873                 ret->remote = remote_get(ret->remote_name);
874                 if (ret->merge_nr) {
875                         int i;
876                         ret->merge = xcalloc(sizeof(*ret->merge),
877                                              ret->merge_nr);
878                         for (i = 0; i < ret->merge_nr; i++) {
879                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
880                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
881                                 remote_find_tracking(ret->remote,
882                                                      ret->merge[i]);
883                         }
884                 }
885         }
886         return ret;
887 }
888
889 int branch_has_merge_config(struct branch *branch)
890 {
891         return branch && !!branch->merge;
892 }
893
894 int branch_merge_matches(struct branch *branch,
895                                  int i,
896                                  const char *refname)
897 {
898         if (!branch || i < 0 || i >= branch->merge_nr)
899                 return 0;
900         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
901 }
902
903 static struct ref *get_expanded_map(const struct ref *remote_refs,
904                                     const struct refspec *refspec)
905 {
906         const struct ref *ref;
907         struct ref *ret = NULL;
908         struct ref **tail = &ret;
909
910         int remote_prefix_len = strlen(refspec->src);
911         int local_prefix_len = strlen(refspec->dst);
912
913         for (ref = remote_refs; ref; ref = ref->next) {
914                 if (strchr(ref->name, '^'))
915                         continue; /* a dereference item */
916                 if (!prefixcmp(ref->name, refspec->src)) {
917                         const char *match;
918                         struct ref *cpy = copy_ref(ref);
919                         match = ref->name + remote_prefix_len;
920
921                         cpy->peer_ref = alloc_ref(local_prefix_len +
922                                                   strlen(match) + 1);
923                         sprintf(cpy->peer_ref->name, "%s%s",
924                                 refspec->dst, match);
925                         if (refspec->force)
926                                 cpy->peer_ref->force = 1;
927                         *tail = cpy;
928                         tail = &cpy->next;
929                 }
930         }
931
932         return ret;
933 }
934
935 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
936 {
937         const struct ref *ref;
938         for (ref = refs; ref; ref = ref->next) {
939                 if (refname_match(name, ref->name, ref_fetch_rules))
940                         return ref;
941         }
942         return NULL;
943 }
944
945 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
946 {
947         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
948
949         if (!ref)
950                 return NULL;
951
952         return copy_ref(ref);
953 }
954
955 static struct ref *get_local_ref(const char *name)
956 {
957         struct ref *ret;
958         if (!name)
959                 return NULL;
960
961         if (!prefixcmp(name, "refs/")) {
962                 ret = alloc_ref(strlen(name) + 1);
963                 strcpy(ret->name, name);
964                 return ret;
965         }
966
967         if (!prefixcmp(name, "heads/") ||
968             !prefixcmp(name, "tags/") ||
969             !prefixcmp(name, "remotes/")) {
970                 ret = alloc_ref(strlen(name) + 6);
971                 sprintf(ret->name, "refs/%s", name);
972                 return ret;
973         }
974
975         ret = alloc_ref(strlen(name) + 12);
976         sprintf(ret->name, "refs/heads/%s", name);
977         return ret;
978 }
979
980 int get_fetch_map(const struct ref *remote_refs,
981                   const struct refspec *refspec,
982                   struct ref ***tail,
983                   int missing_ok)
984 {
985         struct ref *ref_map, **rmp;
986
987         if (refspec->pattern) {
988                 ref_map = get_expanded_map(remote_refs, refspec);
989         } else {
990                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
991
992                 ref_map = get_remote_ref(remote_refs, name);
993                 if (!missing_ok && !ref_map)
994                         die("Couldn't find remote ref %s", name);
995                 if (ref_map) {
996                         ref_map->peer_ref = get_local_ref(refspec->dst);
997                         if (ref_map->peer_ref && refspec->force)
998                                 ref_map->peer_ref->force = 1;
999                 }
1000         }
1001
1002         for (rmp = &ref_map; *rmp; ) {
1003                 if ((*rmp)->peer_ref) {
1004                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1005                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1006                                 struct ref *ignore = *rmp;
1007                                 error("* Ignoring funny ref '%s' locally",
1008                                       (*rmp)->peer_ref->name);
1009                                 *rmp = (*rmp)->next;
1010                                 free(ignore->peer_ref);
1011                                 free(ignore);
1012                                 continue;
1013                         }
1014                 }
1015                 rmp = &((*rmp)->next);
1016         }
1017
1018         if (ref_map)
1019                 tail_link_ref(ref_map, tail);
1020
1021         return 0;
1022 }