Merge branch 'maint'
[git] / remote.c
1 #include "cache.h"
2 #include "remote.h"
3 #include "refs.h"
4 #include "commit.h"
5 #include "diff.h"
6 #include "revision.h"
7
8 static struct refspec s_tag_refspec = {
9         0,
10         1,
11         0,
12         "refs/tags/",
13         "refs/tags/"
14 };
15
16 const struct refspec *tag_refspec = &s_tag_refspec;
17
18 struct counted_string {
19         size_t len;
20         const char *s;
21 };
22 struct rewrite {
23         const char *base;
24         size_t baselen;
25         struct counted_string *instead_of;
26         int instead_of_nr;
27         int instead_of_alloc;
28 };
29
30 static struct remote **remotes;
31 static int remotes_alloc;
32 static int remotes_nr;
33
34 static struct branch **branches;
35 static int branches_alloc;
36 static int branches_nr;
37
38 static struct branch *current_branch;
39 static const char *default_remote_name;
40
41 static struct rewrite **rewrite;
42 static int rewrite_alloc;
43 static int rewrite_nr;
44
45 #define BUF_SIZE (2048)
46 static char buffer[BUF_SIZE];
47
48 static const char *alias_url(const char *url)
49 {
50         int i, j;
51         char *ret;
52         struct counted_string *longest;
53         int longest_i;
54
55         longest = NULL;
56         longest_i = -1;
57         for (i = 0; i < rewrite_nr; i++) {
58                 if (!rewrite[i])
59                         continue;
60                 for (j = 0; j < rewrite[i]->instead_of_nr; j++) {
61                         if (!prefixcmp(url, rewrite[i]->instead_of[j].s) &&
62                             (!longest ||
63                              longest->len < rewrite[i]->instead_of[j].len)) {
64                                 longest = &(rewrite[i]->instead_of[j]);
65                                 longest_i = i;
66                         }
67                 }
68         }
69         if (!longest)
70                 return url;
71
72         ret = malloc(rewrite[longest_i]->baselen +
73                      (strlen(url) - longest->len) + 1);
74         strcpy(ret, rewrite[longest_i]->base);
75         strcpy(ret + rewrite[longest_i]->baselen, url + longest->len);
76         return ret;
77 }
78
79 static void add_push_refspec(struct remote *remote, const char *ref)
80 {
81         ALLOC_GROW(remote->push_refspec,
82                    remote->push_refspec_nr + 1,
83                    remote->push_refspec_alloc);
84         remote->push_refspec[remote->push_refspec_nr++] = ref;
85 }
86
87 static void add_fetch_refspec(struct remote *remote, const char *ref)
88 {
89         ALLOC_GROW(remote->fetch_refspec,
90                    remote->fetch_refspec_nr + 1,
91                    remote->fetch_refspec_alloc);
92         remote->fetch_refspec[remote->fetch_refspec_nr++] = ref;
93 }
94
95 static void add_url(struct remote *remote, const char *url)
96 {
97         ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
98         remote->url[remote->url_nr++] = url;
99 }
100
101 static void add_url_alias(struct remote *remote, const char *url)
102 {
103         add_url(remote, alias_url(url));
104 }
105
106 static struct remote *make_remote(const char *name, int len)
107 {
108         struct remote *ret;
109         int i;
110
111         for (i = 0; i < remotes_nr; i++) {
112                 if (len ? (!strncmp(name, remotes[i]->name, len) &&
113                            !remotes[i]->name[len]) :
114                     !strcmp(name, remotes[i]->name))
115                         return remotes[i];
116         }
117
118         ret = xcalloc(1, sizeof(struct remote));
119         ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
120         remotes[remotes_nr++] = ret;
121         if (len)
122                 ret->name = xstrndup(name, len);
123         else
124                 ret->name = xstrdup(name);
125         return ret;
126 }
127
128 static void add_merge(struct branch *branch, const char *name)
129 {
130         ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
131                    branch->merge_alloc);
132         branch->merge_name[branch->merge_nr++] = name;
133 }
134
135 static struct branch *make_branch(const char *name, int len)
136 {
137         struct branch *ret;
138         int i;
139         char *refname;
140
141         for (i = 0; i < branches_nr; i++) {
142                 if (len ? (!strncmp(name, branches[i]->name, len) &&
143                            !branches[i]->name[len]) :
144                     !strcmp(name, branches[i]->name))
145                         return branches[i];
146         }
147
148         ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
149         ret = xcalloc(1, sizeof(struct branch));
150         branches[branches_nr++] = ret;
151         if (len)
152                 ret->name = xstrndup(name, len);
153         else
154                 ret->name = xstrdup(name);
155         refname = malloc(strlen(name) + strlen("refs/heads/") + 1);
156         strcpy(refname, "refs/heads/");
157         strcpy(refname + strlen("refs/heads/"), ret->name);
158         ret->refname = refname;
159
160         return ret;
161 }
162
163 static struct rewrite *make_rewrite(const char *base, int len)
164 {
165         struct rewrite *ret;
166         int i;
167
168         for (i = 0; i < rewrite_nr; i++) {
169                 if (len
170                     ? (len == rewrite[i]->baselen &&
171                        !strncmp(base, rewrite[i]->base, len))
172                     : !strcmp(base, rewrite[i]->base))
173                         return rewrite[i];
174         }
175
176         ALLOC_GROW(rewrite, rewrite_nr + 1, rewrite_alloc);
177         ret = xcalloc(1, sizeof(struct rewrite));
178         rewrite[rewrite_nr++] = ret;
179         if (len) {
180                 ret->base = xstrndup(base, len);
181                 ret->baselen = len;
182         }
183         else {
184                 ret->base = xstrdup(base);
185                 ret->baselen = strlen(base);
186         }
187         return ret;
188 }
189
190 static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
191 {
192         ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
193         rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
194         rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
195         rewrite->instead_of_nr++;
196 }
197
198 static void read_remotes_file(struct remote *remote)
199 {
200         FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
201
202         if (!f)
203                 return;
204         while (fgets(buffer, BUF_SIZE, f)) {
205                 int value_list;
206                 char *s, *p;
207
208                 if (!prefixcmp(buffer, "URL:")) {
209                         value_list = 0;
210                         s = buffer + 4;
211                 } else if (!prefixcmp(buffer, "Push:")) {
212                         value_list = 1;
213                         s = buffer + 5;
214                 } else if (!prefixcmp(buffer, "Pull:")) {
215                         value_list = 2;
216                         s = buffer + 5;
217                 } else
218                         continue;
219
220                 while (isspace(*s))
221                         s++;
222                 if (!*s)
223                         continue;
224
225                 p = s + strlen(s);
226                 while (isspace(p[-1]))
227                         *--p = 0;
228
229                 switch (value_list) {
230                 case 0:
231                         add_url_alias(remote, xstrdup(s));
232                         break;
233                 case 1:
234                         add_push_refspec(remote, xstrdup(s));
235                         break;
236                 case 2:
237                         add_fetch_refspec(remote, xstrdup(s));
238                         break;
239                 }
240         }
241         fclose(f);
242 }
243
244 static void read_branches_file(struct remote *remote)
245 {
246         const char *slash = strchr(remote->name, '/');
247         char *frag;
248         struct strbuf branch;
249         int n = slash ? slash - remote->name : 1000;
250         FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
251         char *s, *p;
252         int len;
253
254         if (!f)
255                 return;
256         s = fgets(buffer, BUF_SIZE, f);
257         fclose(f);
258         if (!s)
259                 return;
260         while (isspace(*s))
261                 s++;
262         if (!*s)
263                 return;
264         p = s + strlen(s);
265         while (isspace(p[-1]))
266                 *--p = 0;
267         len = p - s;
268         if (slash)
269                 len += strlen(slash);
270         p = xmalloc(len + 1);
271         strcpy(p, s);
272         if (slash)
273                 strcat(p, slash);
274
275         /*
276          * With "slash", e.g. "git fetch jgarzik/netdev-2.6" when
277          * reading from $GIT_DIR/branches/jgarzik fetches "HEAD" from
278          * the partial URL obtained from the branches file plus
279          * "/netdev-2.6" and does not store it in any tracking ref.
280          * #branch specifier in the file is ignored.
281          *
282          * Otherwise, the branches file would have URL and optionally
283          * #branch specified.  The "master" (or specified) branch is
284          * fetched and stored in the local branch of the same name.
285          */
286         strbuf_init(&branch, 0);
287         frag = strchr(p, '#');
288         if (frag) {
289                 *(frag++) = '\0';
290                 strbuf_addf(&branch, "refs/heads/%s", frag);
291         } else
292                 strbuf_addstr(&branch, "refs/heads/master");
293         if (!slash) {
294                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
295         } else {
296                 strbuf_reset(&branch);
297                 strbuf_addstr(&branch, "HEAD:");
298         }
299         add_url_alias(remote, p);
300         add_fetch_refspec(remote, strbuf_detach(&branch, 0));
301         remote->fetch_tags = 1; /* always auto-follow */
302 }
303
304 static int handle_config(const char *key, const char *value, void *cb)
305 {
306         const char *name;
307         const char *subkey;
308         struct remote *remote;
309         struct branch *branch;
310         if (!prefixcmp(key, "branch.")) {
311                 name = key + 7;
312                 subkey = strrchr(name, '.');
313                 if (!subkey)
314                         return 0;
315                 branch = make_branch(name, subkey - name);
316                 if (!strcmp(subkey, ".remote")) {
317                         if (!value)
318                                 return config_error_nonbool(key);
319                         branch->remote_name = xstrdup(value);
320                         if (branch == current_branch)
321                                 default_remote_name = branch->remote_name;
322                 } else if (!strcmp(subkey, ".merge")) {
323                         if (!value)
324                                 return config_error_nonbool(key);
325                         add_merge(branch, xstrdup(value));
326                 }
327                 return 0;
328         }
329         if (!prefixcmp(key, "url.")) {
330                 struct rewrite *rewrite;
331                 name = key + 4;
332                 subkey = strrchr(name, '.');
333                 if (!subkey)
334                         return 0;
335                 rewrite = make_rewrite(name, subkey - name);
336                 if (!strcmp(subkey, ".insteadof")) {
337                         if (!value)
338                                 return config_error_nonbool(key);
339                         add_instead_of(rewrite, xstrdup(value));
340                 }
341         }
342         if (prefixcmp(key,  "remote."))
343                 return 0;
344         name = key + 7;
345         subkey = strrchr(name, '.');
346         if (!subkey)
347                 return error("Config with no key for remote %s", name);
348         if (*subkey == '/') {
349                 warning("Config remote shorthand cannot begin with '/': %s", name);
350                 return 0;
351         }
352         remote = make_remote(name, subkey - name);
353         if (!strcmp(subkey, ".mirror"))
354                 remote->mirror = git_config_bool(key, value);
355         else if (!strcmp(subkey, ".skipdefaultupdate"))
356                 remote->skip_default_update = git_config_bool(key, value);
357
358         else if (!strcmp(subkey, ".url")) {
359                 const char *v;
360                 if (git_config_string(&v, key, value))
361                         return -1;
362                 add_url(remote, v);
363         } else if (!strcmp(subkey, ".push")) {
364                 const char *v;
365                 if (git_config_string(&v, key, value))
366                         return -1;
367                 add_push_refspec(remote, v);
368         } else if (!strcmp(subkey, ".fetch")) {
369                 const char *v;
370                 if (git_config_string(&v, key, value))
371                         return -1;
372                 add_fetch_refspec(remote, v);
373         } else if (!strcmp(subkey, ".receivepack")) {
374                 const char *v;
375                 if (git_config_string(&v, key, value))
376                         return -1;
377                 if (!remote->receivepack)
378                         remote->receivepack = v;
379                 else
380                         error("more than one receivepack given, using the first");
381         } else if (!strcmp(subkey, ".uploadpack")) {
382                 const char *v;
383                 if (git_config_string(&v, key, value))
384                         return -1;
385                 if (!remote->uploadpack)
386                         remote->uploadpack = v;
387                 else
388                         error("more than one uploadpack given, using the first");
389         } else if (!strcmp(subkey, ".tagopt")) {
390                 if (!strcmp(value, "--no-tags"))
391                         remote->fetch_tags = -1;
392         } else if (!strcmp(subkey, ".proxy")) {
393                 return git_config_string((const char **)&remote->http_proxy,
394                                          key, value);
395         }
396         return 0;
397 }
398
399 static void alias_all_urls(void)
400 {
401         int i, j;
402         for (i = 0; i < remotes_nr; i++) {
403                 if (!remotes[i])
404                         continue;
405                 for (j = 0; j < remotes[i]->url_nr; j++) {
406                         remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
407                 }
408         }
409 }
410
411 static void read_config(void)
412 {
413         unsigned char sha1[20];
414         const char *head_ref;
415         int flag;
416         if (default_remote_name) // did this already
417                 return;
418         default_remote_name = xstrdup("origin");
419         current_branch = NULL;
420         head_ref = resolve_ref("HEAD", sha1, 0, &flag);
421         if (head_ref && (flag & REF_ISSYMREF) &&
422             !prefixcmp(head_ref, "refs/heads/")) {
423                 current_branch =
424                         make_branch(head_ref + strlen("refs/heads/"), 0);
425         }
426         git_config(handle_config, NULL);
427         alias_all_urls();
428 }
429
430 /*
431  * We need to make sure the tracking branches are well formed, but a
432  * wildcard refspec in "struct refspec" must have a trailing slash. We
433  * temporarily drop the trailing '/' while calling check_ref_format(),
434  * and put it back.  The caller knows that a CHECK_REF_FORMAT_ONELEVEL
435  * error return is Ok for a wildcard refspec.
436  */
437 static int verify_refname(char *name, int is_glob)
438 {
439         int result, len = -1;
440
441         if (is_glob) {
442                 len = strlen(name);
443                 assert(name[len - 1] == '/');
444                 name[len - 1] = '\0';
445         }
446         result = check_ref_format(name);
447         if (is_glob)
448                 name[len - 1] = '/';
449         return result;
450 }
451
452 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
453 {
454         int i;
455         int st;
456         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
457
458         for (i = 0; i < nr_refspec; i++) {
459                 size_t llen;
460                 int is_glob;
461                 const char *lhs, *rhs;
462
463                 llen = is_glob = 0;
464
465                 lhs = refspec[i];
466                 if (*lhs == '+') {
467                         rs[i].force = 1;
468                         lhs++;
469                 }
470
471                 rhs = strrchr(lhs, ':');
472
473                 /*
474                  * Before going on, special case ":" (or "+:") as a refspec
475                  * for matching refs.
476                  */
477                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
478                         rs[i].matching = 1;
479                         continue;
480                 }
481
482                 if (rhs) {
483                         size_t rlen = strlen(++rhs);
484                         is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
485                         rs[i].dst = xstrndup(rhs, rlen - is_glob);
486                 }
487
488                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
489                 if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
490                         if ((rhs && !is_glob) || (!rhs && fetch))
491                                 goto invalid;
492                         is_glob = 1;
493                         llen--;
494                 } else if (rhs && is_glob) {
495                         goto invalid;
496                 }
497
498                 rs[i].pattern = is_glob;
499                 rs[i].src = xstrndup(lhs, llen);
500
501                 if (fetch) {
502                         /*
503                          * LHS
504                          * - empty is allowed; it means HEAD.
505                          * - otherwise it must be a valid looking ref.
506                          */
507                         if (!*rs[i].src)
508                                 ; /* empty is ok */
509                         else {
510                                 st = verify_refname(rs[i].src, is_glob);
511                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
512                                         goto invalid;
513                         }
514                         /*
515                          * RHS
516                          * - missing is ok, and is same as empty.
517                          * - empty is ok; it means not to store.
518                          * - otherwise it must be a valid looking ref.
519                          */
520                         if (!rs[i].dst) {
521                                 ; /* ok */
522                         } else if (!*rs[i].dst) {
523                                 ; /* ok */
524                         } else {
525                                 st = verify_refname(rs[i].dst, is_glob);
526                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
527                                         goto invalid;
528                         }
529                 } else {
530                         /*
531                          * LHS
532                          * - empty is allowed; it means delete.
533                          * - when wildcarded, it must be a valid looking ref.
534                          * - otherwise, it must be an extended SHA-1, but
535                          *   there is no existing way to validate this.
536                          */
537                         if (!*rs[i].src)
538                                 ; /* empty is ok */
539                         else if (is_glob) {
540                                 st = verify_refname(rs[i].src, is_glob);
541                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
542                                         goto invalid;
543                         }
544                         else
545                                 ; /* anything goes, for now */
546                         /*
547                          * RHS
548                          * - missing is allowed, but LHS then must be a
549                          *   valid looking ref.
550                          * - empty is not allowed.
551                          * - otherwise it must be a valid looking ref.
552                          */
553                         if (!rs[i].dst) {
554                                 st = verify_refname(rs[i].src, is_glob);
555                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
556                                         goto invalid;
557                         } else if (!*rs[i].dst) {
558                                 goto invalid;
559                         } else {
560                                 st = verify_refname(rs[i].dst, is_glob);
561                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
562                                         goto invalid;
563                         }
564                 }
565         }
566         return rs;
567
568  invalid:
569         if (verify) {
570                 free(rs);
571                 return NULL;
572         }
573         die("Invalid refspec '%s'", refspec[i]);
574 }
575
576 int valid_fetch_refspec(const char *fetch_refspec_str)
577 {
578         const char *fetch_refspec[] = { fetch_refspec_str };
579         struct refspec *refspec;
580
581         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
582         if (refspec)
583                 free(refspec);
584         return !!refspec;
585 }
586
587 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
588 {
589         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
590 }
591
592 struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
593 {
594         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
595 }
596
597 static int valid_remote_nick(const char *name)
598 {
599         if (!name[0] || /* not empty */
600             (name[0] == '.' && /* not "." */
601              (!name[1] || /* not ".." */
602               (name[1] == '.' && !name[2]))))
603                 return 0;
604         return !strchr(name, '/'); /* no slash */
605 }
606
607 struct remote *remote_get(const char *name)
608 {
609         struct remote *ret;
610
611         read_config();
612         if (!name)
613                 name = default_remote_name;
614         ret = make_remote(name, 0);
615         if (valid_remote_nick(name)) {
616                 if (!ret->url)
617                         read_remotes_file(ret);
618                 if (!ret->url)
619                         read_branches_file(ret);
620         }
621         if (!ret->url)
622                 add_url_alias(ret, name);
623         if (!ret->url)
624                 return NULL;
625         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
626         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
627         return ret;
628 }
629
630 int for_each_remote(each_remote_fn fn, void *priv)
631 {
632         int i, result = 0;
633         read_config();
634         for (i = 0; i < remotes_nr && !result; i++) {
635                 struct remote *r = remotes[i];
636                 if (!r)
637                         continue;
638                 if (!r->fetch)
639                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
640                                                        r->fetch_refspec);
641                 if (!r->push)
642                         r->push = parse_push_refspec(r->push_refspec_nr,
643                                                      r->push_refspec);
644                 result = fn(r, priv);
645         }
646         return result;
647 }
648
649 void ref_remove_duplicates(struct ref *ref_map)
650 {
651         struct ref **posn;
652         struct ref *next;
653         for (; ref_map; ref_map = ref_map->next) {
654                 if (!ref_map->peer_ref)
655                         continue;
656                 posn = &ref_map->next;
657                 while (*posn) {
658                         if ((*posn)->peer_ref &&
659                             !strcmp((*posn)->peer_ref->name,
660                                     ref_map->peer_ref->name)) {
661                                 if (strcmp((*posn)->name, ref_map->name))
662                                         die("%s tracks both %s and %s",
663                                             ref_map->peer_ref->name,
664                                             (*posn)->name, ref_map->name);
665                                 next = (*posn)->next;
666                                 free((*posn)->peer_ref);
667                                 free(*posn);
668                                 *posn = next;
669                         } else {
670                                 posn = &(*posn)->next;
671                         }
672                 }
673         }
674 }
675
676 int remote_has_url(struct remote *remote, const char *url)
677 {
678         int i;
679         for (i = 0; i < remote->url_nr; i++) {
680                 if (!strcmp(remote->url[i], url))
681                         return 1;
682         }
683         return 0;
684 }
685
686 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
687 {
688         int find_src = refspec->src == NULL;
689         char *needle, **result;
690         int i;
691
692         if (find_src) {
693                 if (!refspec->dst)
694                         return error("find_tracking: need either src or dst");
695                 needle = refspec->dst;
696                 result = &refspec->src;
697         } else {
698                 needle = refspec->src;
699                 result = &refspec->dst;
700         }
701
702         for (i = 0; i < remote->fetch_refspec_nr; i++) {
703                 struct refspec *fetch = &remote->fetch[i];
704                 const char *key = find_src ? fetch->dst : fetch->src;
705                 const char *value = find_src ? fetch->src : fetch->dst;
706                 if (!fetch->dst)
707                         continue;
708                 if (fetch->pattern) {
709                         if (!prefixcmp(needle, key)) {
710                                 *result = xmalloc(strlen(value) +
711                                                   strlen(needle) -
712                                                   strlen(key) + 1);
713                                 strcpy(*result, value);
714                                 strcpy(*result + strlen(value),
715                                        needle + strlen(key));
716                                 refspec->force = fetch->force;
717                                 return 0;
718                         }
719                 } else if (!strcmp(needle, key)) {
720                         *result = xstrdup(value);
721                         refspec->force = fetch->force;
722                         return 0;
723                 }
724         }
725         return -1;
726 }
727
728 struct ref *alloc_ref(unsigned namelen)
729 {
730         struct ref *ret = xmalloc(sizeof(struct ref) + namelen);
731         memset(ret, 0, sizeof(struct ref) + namelen);
732         return ret;
733 }
734
735 struct ref *alloc_ref_from_str(const char* str)
736 {
737         struct ref *ret = alloc_ref(strlen(str) + 1);
738         strcpy(ret->name, str);
739         return ret;
740 }
741
742 static struct ref *copy_ref(const struct ref *ref)
743 {
744         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
745         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
746         ret->next = NULL;
747         return ret;
748 }
749
750 struct ref *copy_ref_list(const struct ref *ref)
751 {
752         struct ref *ret = NULL;
753         struct ref **tail = &ret;
754         while (ref) {
755                 *tail = copy_ref(ref);
756                 ref = ref->next;
757                 tail = &((*tail)->next);
758         }
759         return ret;
760 }
761
762 void free_ref(struct ref *ref)
763 {
764         if (!ref)
765                 return;
766         free(ref->remote_status);
767         free(ref->symref);
768         free(ref);
769 }
770
771 void free_refs(struct ref *ref)
772 {
773         struct ref *next;
774         while (ref) {
775                 next = ref->next;
776                 free(ref->peer_ref);
777                 free_ref(ref);
778                 ref = next;
779         }
780 }
781
782 static int count_refspec_match(const char *pattern,
783                                struct ref *refs,
784                                struct ref **matched_ref)
785 {
786         int patlen = strlen(pattern);
787         struct ref *matched_weak = NULL;
788         struct ref *matched = NULL;
789         int weak_match = 0;
790         int match = 0;
791
792         for (weak_match = match = 0; refs; refs = refs->next) {
793                 char *name = refs->name;
794                 int namelen = strlen(name);
795
796                 if (!refname_match(pattern, name, ref_rev_parse_rules))
797                         continue;
798
799                 /* A match is "weak" if it is with refs outside
800                  * heads or tags, and did not specify the pattern
801                  * in full (e.g. "refs/remotes/origin/master") or at
802                  * least from the toplevel (e.g. "remotes/origin/master");
803                  * otherwise "git push $URL master" would result in
804                  * ambiguity between remotes/origin/master and heads/master
805                  * at the remote site.
806                  */
807                 if (namelen != patlen &&
808                     patlen != namelen - 5 &&
809                     prefixcmp(name, "refs/heads/") &&
810                     prefixcmp(name, "refs/tags/")) {
811                         /* We want to catch the case where only weak
812                          * matches are found and there are multiple
813                          * matches, and where more than one strong
814                          * matches are found, as ambiguous.  One
815                          * strong match with zero or more weak matches
816                          * are acceptable as a unique match.
817                          */
818                         matched_weak = refs;
819                         weak_match++;
820                 }
821                 else {
822                         matched = refs;
823                         match++;
824                 }
825         }
826         if (!matched) {
827                 *matched_ref = matched_weak;
828                 return weak_match;
829         }
830         else {
831                 *matched_ref = matched;
832                 return match;
833         }
834 }
835
836 static void tail_link_ref(struct ref *ref, struct ref ***tail)
837 {
838         **tail = ref;
839         while (ref->next)
840                 ref = ref->next;
841         *tail = &ref->next;
842 }
843
844 static struct ref *try_explicit_object_name(const char *name)
845 {
846         unsigned char sha1[20];
847         struct ref *ref;
848
849         if (!*name) {
850                 ref = alloc_ref(20);
851                 strcpy(ref->name, "(delete)");
852                 hashclr(ref->new_sha1);
853                 return ref;
854         }
855         if (get_sha1(name, sha1))
856                 return NULL;
857         ref = alloc_ref_from_str(name);
858         hashcpy(ref->new_sha1, sha1);
859         return ref;
860 }
861
862 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
863 {
864         struct ref *ret = alloc_ref_from_str(name);
865         tail_link_ref(ret, tail);
866         return ret;
867 }
868
869 static char *guess_ref(const char *name, struct ref *peer)
870 {
871         struct strbuf buf = STRBUF_INIT;
872         unsigned char sha1[20];
873
874         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
875         if (!r)
876                 return NULL;
877
878         if (!prefixcmp(r, "refs/heads/"))
879                 strbuf_addstr(&buf, "refs/heads/");
880         else if (!prefixcmp(r, "refs/tags/"))
881                 strbuf_addstr(&buf, "refs/tags/");
882         else
883                 return NULL;
884
885         strbuf_addstr(&buf, name);
886         return strbuf_detach(&buf, NULL);
887 }
888
889 static int match_explicit(struct ref *src, struct ref *dst,
890                           struct ref ***dst_tail,
891                           struct refspec *rs)
892 {
893         struct ref *matched_src, *matched_dst;
894
895         const char *dst_value = rs->dst;
896         char *dst_guess;
897
898         if (rs->pattern || rs->matching)
899                 return 0;
900
901         matched_src = matched_dst = NULL;
902         switch (count_refspec_match(rs->src, src, &matched_src)) {
903         case 1:
904                 break;
905         case 0:
906                 /* The source could be in the get_sha1() format
907                  * not a reference name.  :refs/other is a
908                  * way to delete 'other' ref at the remote end.
909                  */
910                 matched_src = try_explicit_object_name(rs->src);
911                 if (!matched_src)
912                         return error("src refspec %s does not match any.", rs->src);
913                 break;
914         default:
915                 return error("src refspec %s matches more than one.", rs->src);
916         }
917
918         if (!dst_value) {
919                 unsigned char sha1[20];
920                 int flag;
921
922                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
923                 if (!dst_value ||
924                     ((flag & REF_ISSYMREF) &&
925                      prefixcmp(dst_value, "refs/heads/")))
926                         die("%s cannot be resolved to branch.",
927                             matched_src->name);
928         }
929
930         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
931         case 1:
932                 break;
933         case 0:
934                 if (!memcmp(dst_value, "refs/", 5))
935                         matched_dst = make_linked_ref(dst_value, dst_tail);
936                 else if((dst_guess = guess_ref(dst_value, matched_src)))
937                         matched_dst = make_linked_ref(dst_guess, dst_tail);
938                 else
939                         error("unable to push to unqualified destination: %s\n"
940                               "The destination refspec neither matches an "
941                               "existing ref on the remote nor\n"
942                               "begins with refs/, and we are unable to "
943                               "guess a prefix based on the source ref.",
944                               dst_value);
945                 break;
946         default:
947                 matched_dst = NULL;
948                 error("dst refspec %s matches more than one.",
949                       dst_value);
950                 break;
951         }
952         if (!matched_dst)
953                 return -1;
954         if (matched_dst->peer_ref)
955                 return error("dst ref %s receives from more than one src.",
956                       matched_dst->name);
957         else {
958                 matched_dst->peer_ref = matched_src;
959                 matched_dst->force = rs->force;
960         }
961         return 0;
962 }
963
964 static int match_explicit_refs(struct ref *src, struct ref *dst,
965                                struct ref ***dst_tail, struct refspec *rs,
966                                int rs_nr)
967 {
968         int i, errs;
969         for (i = errs = 0; i < rs_nr; i++)
970                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
971         return errs;
972 }
973
974 static const struct refspec *check_pattern_match(const struct refspec *rs,
975                                                  int rs_nr,
976                                                  const struct ref *src)
977 {
978         int i;
979         int matching_refs = -1;
980         for (i = 0; i < rs_nr; i++) {
981                 if (rs[i].matching &&
982                     (matching_refs == -1 || rs[i].force)) {
983                         matching_refs = i;
984                         continue;
985                 }
986
987                 if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
988                         return rs + i;
989         }
990         if (matching_refs != -1)
991                 return rs + matching_refs;
992         else
993                 return NULL;
994 }
995
996 /*
997  * Note. This is used only by "push"; refspec matching rules for
998  * push and fetch are subtly different, so do not try to reuse it
999  * without thinking.
1000  */
1001 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
1002                int nr_refspec, const char **refspec, int flags)
1003 {
1004         struct refspec *rs;
1005         int send_all = flags & MATCH_REFS_ALL;
1006         int send_mirror = flags & MATCH_REFS_MIRROR;
1007         static const char *default_refspec[] = { ":", 0 };
1008
1009         if (!nr_refspec) {
1010                 nr_refspec = 1;
1011                 refspec = default_refspec;
1012         }
1013         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1014         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
1015                 return -1;
1016
1017         /* pick the remainder */
1018         for ( ; src; src = src->next) {
1019                 struct ref *dst_peer;
1020                 const struct refspec *pat = NULL;
1021                 char *dst_name;
1022                 if (src->peer_ref)
1023                         continue;
1024
1025                 pat = check_pattern_match(rs, nr_refspec, src);
1026                 if (!pat)
1027                         continue;
1028
1029                 if (pat->matching) {
1030                         /*
1031                          * "matching refs"; traditionally we pushed everything
1032                          * including refs outside refs/heads/ hierarchy, but
1033                          * that does not make much sense these days.
1034                          */
1035                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1036                                 continue;
1037                         dst_name = xstrdup(src->name);
1038
1039                 } else {
1040                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1041                         dst_name = xmalloc(strlen(dst_side) +
1042                                            strlen(src->name) -
1043                                            strlen(pat->src) + 2);
1044                         strcpy(dst_name, dst_side);
1045                         strcat(dst_name, src->name + strlen(pat->src));
1046                 }
1047                 dst_peer = find_ref_by_name(dst, dst_name);
1048                 if (dst_peer) {
1049                         if (dst_peer->peer_ref)
1050                                 /* We're already sending something to this ref. */
1051                                 goto free_name;
1052
1053                 } else {
1054                         if (pat->matching && !(send_all || send_mirror))
1055                                 /*
1056                                  * Remote doesn't have it, and we have no
1057                                  * explicit pattern, and we don't have
1058                                  * --all nor --mirror.
1059                                  */
1060                                 goto free_name;
1061
1062                         /* Create a new one and link it */
1063                         dst_peer = make_linked_ref(dst_name, dst_tail);
1064                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1065                 }
1066                 dst_peer->peer_ref = src;
1067                 dst_peer->force = pat->force;
1068         free_name:
1069                 free(dst_name);
1070         }
1071         return 0;
1072 }
1073
1074 struct branch *branch_get(const char *name)
1075 {
1076         struct branch *ret;
1077
1078         read_config();
1079         if (!name || !*name || !strcmp(name, "HEAD"))
1080                 ret = current_branch;
1081         else
1082                 ret = make_branch(name, 0);
1083         if (ret && ret->remote_name) {
1084                 ret->remote = remote_get(ret->remote_name);
1085                 if (ret->merge_nr) {
1086                         int i;
1087                         ret->merge = xcalloc(sizeof(*ret->merge),
1088                                              ret->merge_nr);
1089                         for (i = 0; i < ret->merge_nr; i++) {
1090                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1091                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1092                                 remote_find_tracking(ret->remote,
1093                                                      ret->merge[i]);
1094                         }
1095                 }
1096         }
1097         return ret;
1098 }
1099
1100 int branch_has_merge_config(struct branch *branch)
1101 {
1102         return branch && !!branch->merge;
1103 }
1104
1105 int branch_merge_matches(struct branch *branch,
1106                                  int i,
1107                                  const char *refname)
1108 {
1109         if (!branch || i < 0 || i >= branch->merge_nr)
1110                 return 0;
1111         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1112 }
1113
1114 static struct ref *get_expanded_map(const struct ref *remote_refs,
1115                                     const struct refspec *refspec)
1116 {
1117         const struct ref *ref;
1118         struct ref *ret = NULL;
1119         struct ref **tail = &ret;
1120
1121         int remote_prefix_len = strlen(refspec->src);
1122         int local_prefix_len = strlen(refspec->dst);
1123
1124         for (ref = remote_refs; ref; ref = ref->next) {
1125                 if (strchr(ref->name, '^'))
1126                         continue; /* a dereference item */
1127                 if (!prefixcmp(ref->name, refspec->src)) {
1128                         const char *match;
1129                         struct ref *cpy = copy_ref(ref);
1130                         match = ref->name + remote_prefix_len;
1131
1132                         cpy->peer_ref = alloc_ref(local_prefix_len +
1133                                                   strlen(match) + 1);
1134                         sprintf(cpy->peer_ref->name, "%s%s",
1135                                 refspec->dst, match);
1136                         if (refspec->force)
1137                                 cpy->peer_ref->force = 1;
1138                         *tail = cpy;
1139                         tail = &cpy->next;
1140                 }
1141         }
1142
1143         return ret;
1144 }
1145
1146 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1147 {
1148         const struct ref *ref;
1149         for (ref = refs; ref; ref = ref->next) {
1150                 if (refname_match(name, ref->name, ref_fetch_rules))
1151                         return ref;
1152         }
1153         return NULL;
1154 }
1155
1156 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1157 {
1158         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1159
1160         if (!ref)
1161                 return NULL;
1162
1163         return copy_ref(ref);
1164 }
1165
1166 static struct ref *get_local_ref(const char *name)
1167 {
1168         struct ref *ret;
1169         if (!name)
1170                 return NULL;
1171
1172         if (!prefixcmp(name, "refs/")) {
1173                 return alloc_ref_from_str(name);
1174         }
1175
1176         if (!prefixcmp(name, "heads/") ||
1177             !prefixcmp(name, "tags/") ||
1178             !prefixcmp(name, "remotes/")) {
1179                 ret = alloc_ref(strlen(name) + 6);
1180                 sprintf(ret->name, "refs/%s", name);
1181                 return ret;
1182         }
1183
1184         ret = alloc_ref(strlen(name) + 12);
1185         sprintf(ret->name, "refs/heads/%s", name);
1186         return ret;
1187 }
1188
1189 int get_fetch_map(const struct ref *remote_refs,
1190                   const struct refspec *refspec,
1191                   struct ref ***tail,
1192                   int missing_ok)
1193 {
1194         struct ref *ref_map, **rmp;
1195
1196         if (refspec->pattern) {
1197                 ref_map = get_expanded_map(remote_refs, refspec);
1198         } else {
1199                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1200
1201                 ref_map = get_remote_ref(remote_refs, name);
1202                 if (!missing_ok && !ref_map)
1203                         die("Couldn't find remote ref %s", name);
1204                 if (ref_map) {
1205                         ref_map->peer_ref = get_local_ref(refspec->dst);
1206                         if (ref_map->peer_ref && refspec->force)
1207                                 ref_map->peer_ref->force = 1;
1208                 }
1209         }
1210
1211         for (rmp = &ref_map; *rmp; ) {
1212                 if ((*rmp)->peer_ref) {
1213                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1214                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1215                                 struct ref *ignore = *rmp;
1216                                 error("* Ignoring funny ref '%s' locally",
1217                                       (*rmp)->peer_ref->name);
1218                                 *rmp = (*rmp)->next;
1219                                 free(ignore->peer_ref);
1220                                 free(ignore);
1221                                 continue;
1222                         }
1223                 }
1224                 rmp = &((*rmp)->next);
1225         }
1226
1227         if (ref_map)
1228                 tail_link_ref(ref_map, tail);
1229
1230         return 0;
1231 }
1232
1233 int resolve_remote_symref(struct ref *ref, struct ref *list)
1234 {
1235         if (!ref->symref)
1236                 return 0;
1237         for (; list; list = list->next)
1238                 if (!strcmp(ref->symref, list->name)) {
1239                         hashcpy(ref->old_sha1, list->old_sha1);
1240                         return 0;
1241                 }
1242         return 1;
1243 }
1244
1245 /*
1246  * Return true if there is anything to report, otherwise false.
1247  */
1248 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1249 {
1250         unsigned char sha1[20];
1251         struct commit *ours, *theirs;
1252         char symmetric[84];
1253         struct rev_info revs;
1254         const char *rev_argv[10], *base;
1255         int rev_argc;
1256
1257         /*
1258          * Nothing to report unless we are marked to build on top of
1259          * somebody else.
1260          */
1261         if (!branch ||
1262             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1263                 return 0;
1264
1265         /*
1266          * If what we used to build on no longer exists, there is
1267          * nothing to report.
1268          */
1269         base = branch->merge[0]->dst;
1270         if (!resolve_ref(base, sha1, 1, NULL))
1271                 return 0;
1272         theirs = lookup_commit(sha1);
1273         if (!theirs)
1274                 return 0;
1275
1276         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1277                 return 0;
1278         ours = lookup_commit(sha1);
1279         if (!ours)
1280                 return 0;
1281
1282         /* are we the same? */
1283         if (theirs == ours)
1284                 return 0;
1285
1286         /* Run "rev-list --left-right ours...theirs" internally... */
1287         rev_argc = 0;
1288         rev_argv[rev_argc++] = NULL;
1289         rev_argv[rev_argc++] = "--left-right";
1290         rev_argv[rev_argc++] = symmetric;
1291         rev_argv[rev_argc++] = "--";
1292         rev_argv[rev_argc] = NULL;
1293
1294         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1295         strcpy(symmetric + 40, "...");
1296         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1297
1298         init_revisions(&revs, NULL);
1299         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1300         prepare_revision_walk(&revs);
1301
1302         /* ... and count the commits on each side. */
1303         *num_ours = 0;
1304         *num_theirs = 0;
1305         while (1) {
1306                 struct commit *c = get_revision(&revs);
1307                 if (!c)
1308                         break;
1309                 if (c->object.flags & SYMMETRIC_LEFT)
1310                         (*num_ours)++;
1311                 else
1312                         (*num_theirs)++;
1313         }
1314
1315         /* clear object flags smudged by the above traversal */
1316         clear_commit_marks(ours, ALL_REV_FLAGS);
1317         clear_commit_marks(theirs, ALL_REV_FLAGS);
1318         return 1;
1319 }
1320
1321 /*
1322  * Return true when there is anything to report, otherwise false.
1323  */
1324 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1325 {
1326         int num_ours, num_theirs;
1327         const char *base;
1328
1329         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1330                 return 0;
1331
1332         base = branch->merge[0]->dst;
1333         if (!prefixcmp(base, "refs/remotes/")) {
1334                 base += strlen("refs/remotes/");
1335         }
1336         if (!num_theirs)
1337                 strbuf_addf(sb, "Your branch is ahead of '%s' "
1338                             "by %d commit%s.\n",
1339                             base, num_ours, (num_ours == 1) ? "" : "s");
1340         else if (!num_ours)
1341                 strbuf_addf(sb, "Your branch is behind '%s' "
1342                             "by %d commit%s, "
1343                             "and can be fast-forwarded.\n",
1344                             base, num_theirs, (num_theirs == 1) ? "" : "s");
1345         else
1346                 strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1347                             "and have %d and %d different commit(s) each, "
1348                             "respectively.\n",
1349                             base, num_ours, num_theirs);
1350         return 1;
1351 }