make sure parsed wildcard refspec ends with slash
[git] / remote.c
1 #include "cache.h"
2 #include "remote.h"
3 #include "refs.h"
4
5 static struct refspec s_tag_refspec = {
6         0,
7         1,
8         0,
9         "refs/tags/",
10         "refs/tags/"
11 };
12
13 const struct refspec *tag_refspec = &s_tag_refspec;
14
15 struct counted_string {
16         size_t len;
17         const char *s;
18 };
19 struct rewrite {
20         const char *base;
21         size_t baselen;
22         struct counted_string *instead_of;
23         int instead_of_nr;
24         int instead_of_alloc;
25 };
26
27 static struct remote **remotes;
28 static int remotes_alloc;
29 static int remotes_nr;
30
31 static struct branch **branches;
32 static int branches_alloc;
33 static int branches_nr;
34
35 static struct branch *current_branch;
36 static const char *default_remote_name;
37
38 static struct rewrite **rewrite;
39 static int rewrite_alloc;
40 static int rewrite_nr;
41
42 #define BUF_SIZE (2048)
43 static char buffer[BUF_SIZE];
44
45 static const char *alias_url(const char *url)
46 {
47         int i, j;
48         char *ret;
49         struct counted_string *longest;
50         int longest_i;
51
52         longest = NULL;
53         longest_i = -1;
54         for (i = 0; i < rewrite_nr; i++) {
55                 if (!rewrite[i])
56                         continue;
57                 for (j = 0; j < rewrite[i]->instead_of_nr; j++) {
58                         if (!prefixcmp(url, rewrite[i]->instead_of[j].s) &&
59                             (!longest ||
60                              longest->len < rewrite[i]->instead_of[j].len)) {
61                                 longest = &(rewrite[i]->instead_of[j]);
62                                 longest_i = i;
63                         }
64                 }
65         }
66         if (!longest)
67                 return url;
68
69         ret = malloc(rewrite[longest_i]->baselen +
70                      (strlen(url) - longest->len) + 1);
71         strcpy(ret, rewrite[longest_i]->base);
72         strcpy(ret + rewrite[longest_i]->baselen, url + longest->len);
73         return ret;
74 }
75
76 static void add_push_refspec(struct remote *remote, const char *ref)
77 {
78         ALLOC_GROW(remote->push_refspec,
79                    remote->push_refspec_nr + 1,
80                    remote->push_refspec_alloc);
81         remote->push_refspec[remote->push_refspec_nr++] = ref;
82 }
83
84 static void add_fetch_refspec(struct remote *remote, const char *ref)
85 {
86         ALLOC_GROW(remote->fetch_refspec,
87                    remote->fetch_refspec_nr + 1,
88                    remote->fetch_refspec_alloc);
89         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
90 }
91
92 static void add_url(struct remote *remote, const char *url)
93 {
94         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
95         remote->url[remote->url_nr++] = url;
96 }
97
98 static void add_url_alias(struct remote *remote, const char *url)
99 {
100         add_url(remote, alias_url(url));
101 }
102
103 static struct remote *make_remote(const char *name, int len)
104 {
105         struct remote *ret;
106         int i;
107
108         for (i = 0; i < remotes_nr; i++) {
109                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
110                            !remotes[i]->name[len]) :
111                     !strcmp(name, remotes[i]->name))
112                         return remotes[i];
113         }
114
115         ret = xcalloc(1, sizeof(struct remote));
116         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
117         remotes[remotes_nr++] = ret;
118         if (len)
119                 ret->name = xstrndup(name, len);
120         else
121                 ret->name = xstrdup(name);
122         return ret;
123 }
124
125 static void add_merge(struct branch *branch, const char *name)
126 {
127         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
128                    branch->merge_alloc);
129         branch->merge_name[branch->merge_nr++] = name;
130 }
131
132 static struct branch *make_branch(const char *name, int len)
133 {
134         struct branch *ret;
135         int i;
136         char *refname;
137
138         for (i = 0; i < branches_nr; i++) {
139                 if (len ? (!strncmp(name, branches[i]->name, len) &&
140                            !branches[i]->name[len]) :
141                     !strcmp(name, branches[i]->name))
142                         return branches[i];
143         }
144
145         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
146         ret = xcalloc(1, sizeof(struct branch));
147         branches[branches_nr++] = ret;
148         if (len)
149                 ret->name = xstrndup(name, len);
150         else
151                 ret->name = xstrdup(name);
152         refname = malloc(strlen(name) + strlen("refs/heads/") + 1);
153         strcpy(refname, "refs/heads/");
154         strcpy(refname + strlen("refs/heads/"), ret->name);
155         ret->refname = refname;
156
157         return ret;
158 }
159
160 static struct rewrite *make_rewrite(const char *base, int len)
161 {
162         struct rewrite *ret;
163         int i;
164
165         for (i = 0; i < rewrite_nr; i++) {
166                 if (len
167                     ? (len == rewrite[i]->baselen &&
168                        !strncmp(base, rewrite[i]->base, len))
169                     : !strcmp(base, rewrite[i]->base))
170                         return rewrite[i];
171         }
172
173         ALLOC_GROW(rewrite, rewrite_nr + 1, rewrite_alloc);
174         ret = xcalloc(1, sizeof(struct rewrite));
175         rewrite[rewrite_nr++] = ret;
176         if (len) {
177                 ret->base = xstrndup(base, len);
178                 ret->baselen = len;
179         }
180         else {
181                 ret->base = xstrdup(base);
182                 ret->baselen = strlen(base);
183         }
184         return ret;
185 }
186
187 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
188 {
189         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
190         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
191         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
192         rewrite->instead_of_nr++;
193 }
194
195 static void read_remotes_file(struct remote *remote)
196 {
197         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
198
199         if (!f)
200                 return;
201         while (fgets(buffer, BUF_SIZE, f)) {
202                 int value_list;
203                 char *s, *p;
204
205                 if (!prefixcmp(buffer, "URL:")) {
206                         value_list = 0;
207                         s = buffer + 4;
208                 } else if (!prefixcmp(buffer, "Push:")) {
209                         value_list = 1;
210                         s = buffer + 5;
211                 } else if (!prefixcmp(buffer, "Pull:")) {
212                         value_list = 2;
213                         s = buffer + 5;
214                 } else
215                         continue;
216
217                 while (isspace(*s))
218                         s++;
219                 if (!*s)
220                         continue;
221
222                 p = s + strlen(s);
223                 while (isspace(p[-1]))
224                         *--p = 0;
225
226                 switch (value_list) {
227                 case 0:
228                         add_url_alias(remote, xstrdup(s));
229                         break;
230                 case 1:
231                         add_push_refspec(remote, xstrdup(s));
232                         break;
233                 case 2:
234                         add_fetch_refspec(remote, xstrdup(s));
235                         break;
236                 }
237         }
238         fclose(f);
239 }
240
241 static void read_branches_file(struct remote *remote)
242 {
243         const char *slash = strchr(remote->name, '/');
244         char *frag;
245         struct strbuf branch;
246         int n = slash ? slash - remote->name : 1000;
247         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
248         char *s, *p;
249         int len;
250
251         if (!f)
252                 return;
253         s = fgets(buffer, BUF_SIZE, f);
254         fclose(f);
255         if (!s)
256                 return;
257         while (isspace(*s))
258                 s++;
259         if (!*s)
260                 return;
261         p = s + strlen(s);
262         while (isspace(p[-1]))
263                 *--p = 0;
264         len = p - s;
265         if (slash)
266                 len += strlen(slash);
267         p = xmalloc(len + 1);
268         strcpy(p, s);
269         if (slash)
270                 strcat(p, slash);
271
272         /*
273          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
274          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
275          * the partial URL obtained from the branches file plus
276          * "/netdev-2.6" and does not store it in any tracking ref.
277          * #branch specifier in the file is ignored.
278          *
279          * Otherwise, the branches file would have URL and optionally
280          * #branch specified.  The "master" (or specified) branch is
281          * fetched and stored in the local branch of the same name.
282          */
283         strbuf_init(&branch, 0);
284         frag = strchr(p, '#');
285         if (frag) {
286                 *(frag++) = '\0';
287                 strbuf_addf(&branch, "refs/heads/%s", frag);
288         } else
289                 strbuf_addstr(&branch, "refs/heads/master");
290         if (!slash) {
291                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
292         } else {
293                 strbuf_reset(&branch);
294                 strbuf_addstr(&branch, "HEAD:");
295         }
296         add_url_alias(remote, p);
297         add_fetch_refspec(remote, strbuf_detach(&branch, 0));
298         remote->fetch_tags = 1; /* always auto-follow */
299 }
300
301 static int handle_config(const char *key, const char *value, void *cb)
302 {
303         const char *name;
304         const char *subkey;
305         struct remote *remote;
306         struct branch *branch;
307         if (!prefixcmp(key, "branch.")) {
308                 name = key + 7;
309                 subkey = strrchr(name, '.');
310                 if (!subkey)
311                         return 0;
312                 branch = make_branch(name, subkey - name);
313                 if (!strcmp(subkey, ".remote")) {
314                         if (!value)
315                                 return config_error_nonbool(key);
316                         branch->remote_name = xstrdup(value);
317                         if (branch == current_branch)
318                                 default_remote_name = branch->remote_name;
319                 } else if (!strcmp(subkey, ".merge")) {
320                         if (!value)
321                                 return config_error_nonbool(key);
322                         add_merge(branch, xstrdup(value));
323                 }
324                 return 0;
325         }
326         if (!prefixcmp(key, "url.")) {
327                 struct rewrite *rewrite;
328                 name = key + 4;
329                 subkey = strrchr(name, '.');
330                 if (!subkey)
331                         return 0;
332                 rewrite = make_rewrite(name, subkey - name);
333                 if (!strcmp(subkey, ".insteadof")) {
334                         if (!value)
335                                 return config_error_nonbool(key);
336                         add_instead_of(rewrite, xstrdup(value));
337                 }
338         }
339         if (prefixcmp(key,  "remote."))
340                 return 0;
341         name = key + 7;
342         subkey = strrchr(name, '.');
343         if (!subkey)
344                 return error("Config with no key for remote %s", name);
345         if (*subkey == '/') {
346                 warning("Config remote shorthand cannot begin with '/': %s", name);
347                 return 0;
348         }
349         remote = make_remote(name, subkey - name);
350         if (!strcmp(subkey, ".mirror"))
351                 remote->mirror = git_config_bool(key, value);
352         else if (!strcmp(subkey, ".skipdefaultupdate"))
353                 remote->skip_default_update = git_config_bool(key, value);
354
355         else if (!strcmp(subkey, ".url")) {
356                 const char *v;
357                 if (git_config_string(&v, key, value))
358                         return -1;
359                 add_url(remote, v);
360         } else if (!strcmp(subkey, ".push")) {
361                 const char *v;
362                 if (git_config_string(&v, key, value))
363                         return -1;
364                 add_push_refspec(remote, v);
365         } else if (!strcmp(subkey, ".fetch")) {
366                 const char *v;
367                 if (git_config_string(&v, key, value))
368                         return -1;
369                 add_fetch_refspec(remote, v);
370         } else if (!strcmp(subkey, ".receivepack")) {
371                 const char *v;
372                 if (git_config_string(&v, key, value))
373                         return -1;
374                 if (!remote->receivepack)
375                         remote->receivepack = v;
376                 else
377                         error("more than one receivepack given, using the first");
378         } else if (!strcmp(subkey, ".uploadpack")) {
379                 const char *v;
380                 if (git_config_string(&v, key, value))
381                         return -1;
382                 if (!remote->uploadpack)
383                         remote->uploadpack = v;
384                 else
385                         error("more than one uploadpack given, using the first");
386         } else if (!strcmp(subkey, ".tagopt")) {
387                 if (!strcmp(value, "--no-tags"))
388                         remote->fetch_tags = -1;
389         } else if (!strcmp(subkey, ".proxy")) {
390                 return git_config_string((const char **)&remote->http_proxy,
391                                          key, value);
392         }
393         return 0;
394 }
395
396 static void alias_all_urls(void)
397 {
398         int i, j;
399         for (i = 0; i < remotes_nr; i++) {
400                 if (!remotes[i])
401                         continue;
402                 for (j = 0; j < remotes[i]->url_nr; j++) {
403                         remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
404                 }
405         }
406 }
407
408 static void read_config(void)
409 {
410         unsigned char sha1[20];
411         const char *head_ref;
412         int flag;
413         if (default_remote_name) // did this already
414                 return;
415         default_remote_name = xstrdup("origin");
416         current_branch = NULL;
417         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
418         if (head_ref && (flag & REF_ISSYMREF) &&
419             !prefixcmp(head_ref, "refs/heads/")) {
420                 current_branch =
421                         make_branch(head_ref + strlen("refs/heads/"), 0);
422         }
423         git_config(handle_config, NULL);
424         alias_all_urls();
425 }
426
427 /*
428  * We need to make sure the tracking branches are well formed, but a
429  * wildcard refspec in "struct refspec" must have a trailing slash. We
430  * temporarily drop the trailing '/' while calling check_ref_format(),
431  * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
432  * error return is Ok for a wildcard refspec.
433  */
434 static int verify_refname(char *name, int is_glob)
435 {
436         int result, len = -1;
437
438         if (is_glob) {
439                 len = strlen(name);
440                 assert(name[len - 1] == '/');
441                 name[len - 1] = '\0';
442         }
443         result = check_ref_format(name);
444         if (is_glob)
445                 name[len - 1] = '/';
446         return result;
447 }
448
449 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
450 {
451         int i;
452         int st;
453         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
454
455         for (i = 0; i < nr_refspec; i++) {
456                 size_t llen;
457                 int is_glob;
458                 const char *lhs, *rhs;
459
460                 llen = is_glob = 0;
461
462                 lhs = refspec[i];
463                 if (*lhs == '+') {
464                         rs[i].force = 1;
465                         lhs++;
466                 }
467
468                 rhs = strrchr(lhs, ':');
469
470                 /*
471                  * Before going on, special case ":" (or "+:") as a refspec
472                  * for matching refs.
473                  */
474                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
475                         rs[i].matching = 1;
476                         continue;
477                 }
478
479                 if (rhs) {
480                         size_t rlen = strlen(++rhs);
481                         is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
482                         rs[i].dst = xstrndup(rhs, rlen - is_glob);
483                 }
484
485                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
486                 if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
487                         if ((rhs && !is_glob) || (!rhs && fetch))
488                                 goto invalid;
489                         is_glob = 1;
490                         llen--;
491                 } else if (rhs && is_glob) {
492                         goto invalid;
493                 }
494
495                 rs[i].pattern = is_glob;
496                 rs[i].src = xstrndup(lhs, llen);
497
498                 if (fetch) {
499                         /*
500                          * LHS
501                          * - empty is allowed; it means HEAD.
502                          * - otherwise it must be a valid looking ref.
503                          */
504                         if (!*rs[i].src)
505                                 ; /* empty is ok */
506                         else {
507                                 st = verify_refname(rs[i].src, is_glob);
508                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
509                                         goto invalid;
510                         }
511                         /*
512                          * RHS
513                          * - missing is ok, and is same as empty.
514                          * - empty is ok; it means not to store.
515                          * - otherwise it must be a valid looking ref.
516                          */
517                         if (!rs[i].dst) {
518                                 ; /* ok */
519                         } else if (!*rs[i].dst) {
520                                 ; /* ok */
521                         } else {
522                                 st = verify_refname(rs[i].dst, is_glob);
523                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
524                                         goto invalid;
525                         }
526                 } else {
527                         /*
528                          * LHS
529                          * - empty is allowed; it means delete.
530                          * - when wildcarded, it must be a valid looking ref.
531                          * - otherwise, it must be an extended SHA-1, but
532                          *   there is no existing way to validate this.
533                          */
534                         if (!*rs[i].src)
535                                 ; /* empty is ok */
536                         else if (is_glob) {
537                                 st = verify_refname(rs[i].src, is_glob);
538                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
539                                         goto invalid;
540                         }
541                         else
542                                 ; /* anything goes, for now */
543                         /*
544                          * RHS
545                          * - missing is allowed, but LHS then must be a
546                          *   valid looking ref.
547                          * - empty is not allowed.
548                          * - otherwise it must be a valid looking ref.
549                          */
550                         if (!rs[i].dst) {
551                                 st = verify_refname(rs[i].src, is_glob);
552                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
553                                         goto invalid;
554                         } else if (!*rs[i].dst) {
555                                 goto invalid;
556                         } else {
557                                 st = verify_refname(rs[i].dst, is_glob);
558                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
559                                         goto invalid;
560                         }
561                 }
562         }
563         return rs;
564
565  invalid:
566         if (verify) {
567                 free(rs);
568                 return NULL;
569         }
570         die("Invalid refspec '%s'", refspec[i]);
571 }
572
573 int valid_fetch_refspec(const char *fetch_refspec_str)
574 {
575         const char *fetch_refspec[] = { fetch_refspec_str };
576         struct refspec *refspec;
577
578         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
579         if (refspec)
580                 free(refspec);
581         return !!refspec;
582 }
583
584 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
585 {
586         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
587 }
588
589 struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
590 {
591         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
592 }
593
594 static int valid_remote_nick(const char *name)
595 {
596         if (!name[0] || /* not empty */
597             (name[0] == '.' && /* not "." */
598              (!name[1] || /* not ".." */
599               (name[1] == '.' && !name[2]))))
600                 return 0;
601         return !strchr(name, '/'); /* no slash */
602 }
603
604 struct remote *remote_get(const char *name)
605 {
606         struct remote *ret;
607
608         read_config();
609         if (!name)
610                 name = default_remote_name;
611         ret = make_remote(name, 0);
612         if (valid_remote_nick(name)) {
613                 if (!ret->url)
614                         read_remotes_file(ret);
615                 if (!ret->url)
616                         read_branches_file(ret);
617         }
618         if (!ret->url)
619                 add_url_alias(ret, name);
620         if (!ret->url)
621                 return NULL;
622         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
623         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
624         return ret;
625 }
626
627 int for_each_remote(each_remote_fn fn, void *priv)
628 {
629         int i, result = 0;
630         read_config();
631         for (i = 0; i < remotes_nr && !result; i++) {
632                 struct remote *r = remotes[i];
633                 if (!r)
634                         continue;
635                 if (!r->fetch)
636                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
637                                                        r->fetch_refspec);
638                 if (!r->push)
639                         r->push = parse_push_refspec(r->push_refspec_nr,
640                                                      r->push_refspec);
641                 result = fn(r, priv);
642         }
643         return result;
644 }
645
646 void ref_remove_duplicates(struct ref *ref_map)
647 {
648         struct ref **posn;
649         struct ref *next;
650         for (; ref_map; ref_map = ref_map->next) {
651                 if (!ref_map->peer_ref)
652                         continue;
653                 posn = &ref_map->next;
654                 while (*posn) {
655                         if ((*posn)->peer_ref &&
656                             !strcmp((*posn)->peer_ref->name,
657                                     ref_map->peer_ref->name)) {
658                                 if (strcmp((*posn)->name, ref_map->name))
659                                         die("%s tracks both %s and %s",
660                                             ref_map->peer_ref->name,
661                                             (*posn)->name, ref_map->name);
662                                 next = (*posn)->next;
663                                 free((*posn)->peer_ref);
664                                 free(*posn);
665                                 *posn = next;
666                         } else {
667                                 posn = &(*posn)->next;
668                         }
669                 }
670         }
671 }
672
673 int remote_has_url(struct remote *remote, const char *url)
674 {
675         int i;
676         for (i = 0; i < remote->url_nr; i++) {
677                 if (!strcmp(remote->url[i], url))
678                         return 1;
679         }
680         return 0;
681 }
682
683 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
684 {
685         int find_src = refspec->src == NULL;
686         char *needle, **result;
687         int i;
688
689         if (find_src) {
690                 if (!refspec->dst)
691                         return error("find_tracking: need either src or dst");
692                 needle = refspec->dst;
693                 result = &refspec->src;
694         } else {
695                 needle = refspec->src;
696                 result = &refspec->dst;
697         }
698
699         for (i = 0; i < remote->fetch_refspec_nr; i++) {
700                 struct refspec *fetch = &remote->fetch[i];
701                 const char *key = find_src ? fetch->dst : fetch->src;
702                 const char *value = find_src ? fetch->src : fetch->dst;
703                 if (!fetch->dst)
704                         continue;
705                 if (fetch->pattern) {
706                         if (!prefixcmp(needle, key)) {
707                                 *result = xmalloc(strlen(value) +
708                                                   strlen(needle) -
709                                                   strlen(key) + 1);
710                                 strcpy(*result, value);
711                                 strcpy(*result + strlen(value),
712                                        needle + strlen(key));
713                                 refspec->force = fetch->force;
714                                 return 0;
715                         }
716                 } else if (!strcmp(needle, key)) {
717                         *result = xstrdup(value);
718                         refspec->force = fetch->force;
719                         return 0;
720                 }
721         }
722         return -1;
723 }
724
725 struct ref *alloc_ref(unsigned namelen)
726 {
727         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
728         memset(ret, 0, sizeof(struct ref) + namelen);
729         return ret;
730 }
731
732 struct ref *alloc_ref_from_str(const char* str)
733 {
734         struct ref *ret = alloc_ref(strlen(str) + 1);
735         strcpy(ret->name, str);
736         return ret;
737 }
738
739 static struct ref *copy_ref(const struct ref *ref)
740 {
741         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
742         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
743         ret->next = NULL;
744         return ret;
745 }
746
747 struct ref *copy_ref_list(const struct ref *ref)
748 {
749         struct ref *ret = NULL;
750         struct ref **tail = &ret;
751         while (ref) {
752                 *tail = copy_ref(ref);
753                 ref = ref->next;
754                 tail = &((*tail)->next);
755         }
756         return ret;
757 }
758
759 void free_ref(struct ref *ref)
760 {
761         if (!ref)
762                 return;
763         free(ref->remote_status);
764         free(ref->symref);
765         free(ref);
766 }
767
768 void free_refs(struct ref *ref)
769 {
770         struct ref *next;
771         while (ref) {
772                 next = ref->next;
773                 free(ref->peer_ref);
774                 free_ref(ref);
775                 ref = next;
776         }
777 }
778
779 static int count_refspec_match(const char *pattern,
780                                struct ref *refs,
781                                struct ref **matched_ref)
782 {
783         int patlen = strlen(pattern);
784         struct ref *matched_weak = NULL;
785         struct ref *matched = NULL;
786         int weak_match = 0;
787         int match = 0;
788
789         for (weak_match = match = 0; refs; refs = refs->next) {
790                 char *name = refs->name;
791                 int namelen = strlen(name);
792
793                 if (!refname_match(pattern, name, ref_rev_parse_rules))
794                         continue;
795
796                 /* A match is "weak" if it is with refs outside
797                  * heads or tags, and did not specify the pattern
798                  * in full (e.g. "refs/remotes/origin/master") or at
799                  * least from the toplevel (e.g. "remotes/origin/master");
800                  * otherwise "git push $URL master" would result in
801                  * ambiguity between remotes/origin/master and heads/master
802                  * at the remote site.
803                  */
804                 if (namelen != patlen &&
805                     patlen != namelen - 5 &&
806                     prefixcmp(name, "refs/heads/") &&
807                     prefixcmp(name, "refs/tags/")) {
808                         /* We want to catch the case where only weak
809                          * matches are found and there are multiple
810                          * matches, and where more than one strong
811                          * matches are found, as ambiguous.  One
812                          * strong match with zero or more weak matches
813                          * are acceptable as a unique match.
814                          */
815                         matched_weak = refs;
816                         weak_match++;
817                 }
818                 else {
819                         matched = refs;
820                         match++;
821                 }
822         }
823         if (!matched) {
824                 *matched_ref = matched_weak;
825                 return weak_match;
826         }
827         else {
828                 *matched_ref = matched;
829                 return match;
830         }
831 }
832
833 static void tail_link_ref(struct ref *ref, struct ref ***tail)
834 {
835         **tail = ref;
836         while (ref->next)
837                 ref = ref->next;
838         *tail = &ref->next;
839 }
840
841 static struct ref *try_explicit_object_name(const char *name)
842 {
843         unsigned char sha1[20];
844         struct ref *ref;
845
846         if (!*name) {
847                 ref = alloc_ref(20);
848                 strcpy(ref->name, "(delete)");
849                 hashclr(ref->new_sha1);
850                 return ref;
851         }
852         if (get_sha1(name, sha1))
853                 return NULL;
854         ref = alloc_ref_from_str(name);
855         hashcpy(ref->new_sha1, sha1);
856         return ref;
857 }
858
859 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
860 {
861         struct ref *ret = alloc_ref_from_str(name);
862         tail_link_ref(ret, tail);
863         return ret;
864 }
865
866 static char *guess_ref(const char *name, struct ref *peer)
867 {
868         struct strbuf buf = STRBUF_INIT;
869         unsigned char sha1[20];
870
871         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
872         if (!r)
873                 return NULL;
874
875         if (!prefixcmp(r, "refs/heads/"))
876                 strbuf_addstr(&buf, "refs/heads/");
877         else if (!prefixcmp(r, "refs/tags/"))
878                 strbuf_addstr(&buf, "refs/tags/");
879         else
880                 return NULL;
881
882         strbuf_addstr(&buf, name);
883         return strbuf_detach(&buf, NULL);
884 }
885
886 static int match_explicit(struct ref *src, struct ref *dst,
887                           struct ref ***dst_tail,
888                           struct refspec *rs)
889 {
890         struct ref *matched_src, *matched_dst;
891
892         const char *dst_value = rs->dst;
893         char *dst_guess;
894
895         if (rs->pattern || rs->matching)
896                 return 0;
897
898         matched_src = matched_dst = NULL;
899         switch (count_refspec_match(rs->src, src, &matched_src)) {
900         case 1:
901                 break;
902         case 0:
903                 /* The source could be in the get_sha1() format
904                  * not a reference name.  :refs/other is a
905                  * way to delete 'other' ref at the remote end.
906                  */
907                 matched_src = try_explicit_object_name(rs->src);
908                 if (!matched_src)
909                         return error("src refspec %s does not match any.", rs->src);
910                 break;
911         default:
912                 return error("src refspec %s matches more than one.", rs->src);
913         }
914
915         if (!dst_value) {
916                 unsigned char sha1[20];
917                 int flag;
918
919                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
920                 if (!dst_value ||
921                     ((flag & REF_ISSYMREF) &&
922                      prefixcmp(dst_value, "refs/heads/")))
923                         die("%s cannot be resolved to branch.",
924                             matched_src->name);
925         }
926
927         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
928         case 1:
929                 break;
930         case 0:
931                 if (!memcmp(dst_value, "refs/", 5))
932                         matched_dst = make_linked_ref(dst_value, dst_tail);
933                 else if((dst_guess = guess_ref(dst_value, matched_src)))
934                         matched_dst = make_linked_ref(dst_guess, dst_tail);
935                 else
936                         error("unable to push to unqualified destination: %s\n"
937                               "The destination refspec neither matches an "
938                               "existing ref on the remote nor\n"
939                               "begins with refs/, and we are unable to "
940                               "guess a prefix based on the source ref.",
941                               dst_value);
942                 break;
943         default:
944                 matched_dst = NULL;
945                 error("dst refspec %s matches more than one.",
946                       dst_value);
947                 break;
948         }
949         if (!matched_dst)
950                 return -1;
951         if (matched_dst->peer_ref)
952                 return error("dst ref %s receives from more than one src.",
953                       matched_dst->name);
954         else {
955                 matched_dst->peer_ref = matched_src;
956                 matched_dst->force = rs->force;
957         }
958         return 0;
959 }
960
961 static int match_explicit_refs(struct ref *src, struct ref *dst,
962                                struct ref ***dst_tail, struct refspec *rs,
963                                int rs_nr)
964 {
965         int i, errs;
966         for (i = errs = 0; i < rs_nr; i++)
967                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
968         return errs;
969 }
970
971 static const struct refspec *check_pattern_match(const struct refspec *rs,
972                                                  int rs_nr,
973                                                  const struct ref *src)
974 {
975         int i;
976         int matching_refs = -1;
977         for (i = 0; i < rs_nr; i++) {
978                 if (rs[i].matching &&
979                     (matching_refs == -1 || rs[i].force)) {
980                         matching_refs = i;
981                         continue;
982                 }
983
984                 if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
985                         return rs + i;
986         }
987         if (matching_refs != -1)
988                 return rs + matching_refs;
989         else
990                 return NULL;
991 }
992
993 /*
994  * Note. This is used only by "push"; refspec matching rules for
995  * push and fetch are subtly different, so do not try to reuse it
996  * without thinking.
997  */
998 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
999                int nr_refspec, const char **refspec, int flags)
1000 {
1001         struct refspec *rs;
1002         int send_all = flags & MATCH_REFS_ALL;
1003         int send_mirror = flags & MATCH_REFS_MIRROR;
1004         static const char *default_refspec[] = { ":", 0 };
1005
1006         if (!nr_refspec) {
1007                 nr_refspec = 1;
1008                 refspec = default_refspec;
1009         }
1010         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1011         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
1012                 return -1;
1013
1014         /* pick the remainder */
1015         for ( ; src; src = src->next) {
1016                 struct ref *dst_peer;
1017                 const struct refspec *pat = NULL;
1018                 char *dst_name;
1019                 if (src->peer_ref)
1020                         continue;
1021
1022                 pat = check_pattern_match(rs, nr_refspec, src);
1023                 if (!pat)
1024                         continue;
1025
1026                 if (pat->matching) {
1027                         /*
1028                          * "matching refs"; traditionally we pushed everything
1029                          * including refs outside refs/heads/ hierarchy, but
1030                          * that does not make much sense these days.
1031                          */
1032                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1033                                 continue;
1034                         dst_name = xstrdup(src->name);
1035
1036                 } else {
1037                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1038                         dst_name = xmalloc(strlen(dst_side) +
1039                                            strlen(src->name) -
1040                                            strlen(pat->src) + 2);
1041                         strcpy(dst_name, dst_side);
1042                         strcat(dst_name, src->name + strlen(pat->src));
1043                 }
1044                 dst_peer = find_ref_by_name(dst, dst_name);
1045                 if (dst_peer) {
1046                         if (dst_peer->peer_ref)
1047                                 /* We're already sending something to this ref. */
1048                                 goto free_name;
1049
1050                 } else {
1051                         if (pat->matching && !(send_all || send_mirror))
1052                                 /*
1053                                  * Remote doesn't have it, and we have no
1054                                  * explicit pattern, and we don't have
1055                                  * --all nor --mirror.
1056                                  */
1057                                 goto free_name;
1058
1059                         /* Create a new one and link it */
1060                         dst_peer = make_linked_ref(dst_name, dst_tail);
1061                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1062                 }
1063                 dst_peer->peer_ref = src;
1064                 dst_peer->force = pat->force;
1065         free_name:
1066                 free(dst_name);
1067         }
1068         return 0;
1069 }
1070
1071 struct branch *branch_get(const char *name)
1072 {
1073         struct branch *ret;
1074
1075         read_config();
1076         if (!name || !*name || !strcmp(name, "HEAD"))
1077                 ret = current_branch;
1078         else
1079                 ret = make_branch(name, 0);
1080         if (ret && ret->remote_name) {
1081                 ret->remote = remote_get(ret->remote_name);
1082                 if (ret->merge_nr) {
1083                         int i;
1084                         ret->merge = xcalloc(sizeof(*ret->merge),
1085                                              ret->merge_nr);
1086                         for (i = 0; i < ret->merge_nr; i++) {
1087                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1088                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1089                                 remote_find_tracking(ret->remote,
1090                                                      ret->merge[i]);
1091                         }
1092                 }
1093         }
1094         return ret;
1095 }
1096
1097 int branch_has_merge_config(struct branch *branch)
1098 {
1099         return branch && !!branch->merge;
1100 }
1101
1102 int branch_merge_matches(struct branch *branch,
1103                                  int i,
1104                                  const char *refname)
1105 {
1106         if (!branch || i < 0 || i >= branch->merge_nr)
1107                 return 0;
1108         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1109 }
1110
1111 static struct ref *get_expanded_map(const struct ref *remote_refs,
1112                                     const struct refspec *refspec)
1113 {
1114         const struct ref *ref;
1115         struct ref *ret = NULL;
1116         struct ref **tail = &ret;
1117
1118         int remote_prefix_len = strlen(refspec->src);
1119         int local_prefix_len = strlen(refspec->dst);
1120
1121         for (ref = remote_refs; ref; ref = ref->next) {
1122                 if (strchr(ref->name, '^'))
1123                         continue; /* a dereference item */
1124                 if (!prefixcmp(ref->name, refspec->src)) {
1125                         const char *match;
1126                         struct ref *cpy = copy_ref(ref);
1127                         match = ref->name + remote_prefix_len;
1128
1129                         cpy->peer_ref = alloc_ref(local_prefix_len +
1130                                                   strlen(match) + 1);
1131                         sprintf(cpy->peer_ref->name, "%s%s",
1132                                 refspec->dst, match);
1133                         if (refspec->force)
1134                                 cpy->peer_ref->force = 1;
1135                         *tail = cpy;
1136                         tail = &cpy->next;
1137                 }
1138         }
1139
1140         return ret;
1141 }
1142
1143 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1144 {
1145         const struct ref *ref;
1146         for (ref = refs; ref; ref = ref->next) {
1147                 if (refname_match(name, ref->name, ref_fetch_rules))
1148                         return ref;
1149         }
1150         return NULL;
1151 }
1152
1153 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1154 {
1155         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1156
1157         if (!ref)
1158                 return NULL;
1159
1160         return copy_ref(ref);
1161 }
1162
1163 static struct ref *get_local_ref(const char *name)
1164 {
1165         struct ref *ret;
1166         if (!name)
1167                 return NULL;
1168
1169         if (!prefixcmp(name, "refs/")) {
1170                 return alloc_ref_from_str(name);
1171         }
1172
1173         if (!prefixcmp(name, "heads/") ||
1174             !prefixcmp(name, "tags/") ||
1175             !prefixcmp(name, "remotes/")) {
1176                 ret = alloc_ref(strlen(name) + 6);
1177                 sprintf(ret->name, "refs/%s", name);
1178                 return ret;
1179         }
1180
1181         ret = alloc_ref(strlen(name) + 12);
1182         sprintf(ret->name, "refs/heads/%s", name);
1183         return ret;
1184 }
1185
1186 int get_fetch_map(const struct ref *remote_refs,
1187                   const struct refspec *refspec,
1188                   struct ref ***tail,
1189                   int missing_ok)
1190 {
1191         struct ref *ref_map, **rmp;
1192
1193         if (refspec->pattern) {
1194                 ref_map = get_expanded_map(remote_refs, refspec);
1195         } else {
1196                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1197
1198                 ref_map = get_remote_ref(remote_refs, name);
1199                 if (!missing_ok && !ref_map)
1200                         die("Couldn't find remote ref %s", name);
1201                 if (ref_map) {
1202                         ref_map->peer_ref = get_local_ref(refspec->dst);
1203                         if (ref_map->peer_ref && refspec->force)
1204                                 ref_map->peer_ref->force = 1;
1205                 }
1206         }
1207
1208         for (rmp = &ref_map; *rmp; ) {
1209                 if ((*rmp)->peer_ref) {
1210                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1211                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1212                                 struct ref *ignore = *rmp;
1213                                 error("* Ignoring funny ref '%s' locally",
1214                                       (*rmp)->peer_ref->name);
1215                                 *rmp = (*rmp)->next;
1216                                 free(ignore->peer_ref);
1217                                 free(ignore);
1218                                 continue;
1219                         }
1220                 }
1221                 rmp = &((*rmp)->next);
1222         }
1223
1224         if (ref_map)
1225                 tail_link_ref(ref_map, tail);
1226
1227         return 0;
1228 }
1229
1230 int resolve_remote_symref(struct ref *ref, struct ref *list)
1231 {
1232         if (!ref->symref)
1233                 return 0;
1234         for (; list; list = list->next)
1235                 if (!strcmp(ref->symref, list->name)) {
1236                         hashcpy(ref->old_sha1, list->old_sha1);
1237                         return 0;
1238                 }
1239         return 1;
1240 }