Merge branch 'ns/rebase-noverify'
[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 = xmalloc(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 = xmalloc(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 = STRBUF_INIT;
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         frag = strchr(p, '#');
287         if (frag) {
288                 *(frag++) = '\0';
289                 strbuf_addf(&branch, "refs/heads/%s", frag);
290         } else
291                 strbuf_addstr(&branch, "refs/heads/master");
292         if (!slash) {
293                 strbuf_addf(&branch, ":refs/heads/%s", remote->name);
294         } else {
295                 strbuf_reset(&branch);
296                 strbuf_addstr(&branch, "HEAD:");
297         }
298         add_url_alias(remote, p);
299         add_fetch_refspec(remote, strbuf_detach(&branch, 0));
300         remote->fetch_tags = 1; /* always auto-follow */
301 }
302
303 static int handle_config(const char *key, const char *value, void *cb)
304 {
305         const char *name;
306         const char *subkey;
307         struct remote *remote;
308         struct branch *branch;
309         if (!prefixcmp(key, "branch.")) {
310                 name = key + 7;
311                 subkey = strrchr(name, '.');
312                 if (!subkey)
313                         return 0;
314                 branch = make_branch(name, subkey - name);
315                 if (!strcmp(subkey, ".remote")) {
316                         if (!value)
317                                 return config_error_nonbool(key);
318                         branch->remote_name = xstrdup(value);
319                         if (branch == current_branch)
320                                 default_remote_name = branch->remote_name;
321                 } else if (!strcmp(subkey, ".merge")) {
322                         if (!value)
323                                 return config_error_nonbool(key);
324                         add_merge(branch, xstrdup(value));
325                 }
326                 return 0;
327         }
328         if (!prefixcmp(key, "url.")) {
329                 struct rewrite *rewrite;
330                 name = key + 4;
331                 subkey = strrchr(name, '.');
332                 if (!subkey)
333                         return 0;
334                 rewrite = make_rewrite(name, subkey - name);
335                 if (!strcmp(subkey, ".insteadof")) {
336                         if (!value)
337                                 return config_error_nonbool(key);
338                         add_instead_of(rewrite, xstrdup(value));
339                 }
340         }
341         if (prefixcmp(key,  "remote."))
342                 return 0;
343         name = key + 7;
344         if (*name == '/') {
345                 warning("Config remote shorthand cannot begin with '/': %s",
346                         name);
347                 return 0;
348         }
349         subkey = strrchr(name, '.');
350         if (!subkey)
351                 return error("Config with no key for remote %s", name);
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 /*
453  * This function frees a refspec array.
454  * Warning: code paths should be checked to ensure that the src
455  *          and dst pointers are always freeable pointers as well
456  *          as the refspec pointer itself.
457  */
458 static void free_refspecs(struct refspec *refspec, int nr_refspec)
459 {
460         int i;
461
462         if (!refspec)
463                 return;
464
465         for (i = 0; i < nr_refspec; i++) {
466                 free(refspec[i].src);
467                 free(refspec[i].dst);
468         }
469         free(refspec);
470 }
471
472 static struct refspec *parse_refspec_internal(int nr_refspec, const char **refspec, int fetch, int verify)
473 {
474         int i;
475         int st;
476         struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
477
478         for (i = 0; i < nr_refspec; i++) {
479                 size_t llen;
480                 int is_glob;
481                 const char *lhs, *rhs;
482
483                 llen = is_glob = 0;
484
485                 lhs = refspec[i];
486                 if (*lhs == '+') {
487                         rs[i].force = 1;
488                         lhs++;
489                 }
490
491                 rhs = strrchr(lhs, ':');
492
493                 /*
494                  * Before going on, special case ":" (or "+:") as a refspec
495                  * for matching refs.
496                  */
497                 if (!fetch && rhs == lhs && rhs[1] == '\0') {
498                         rs[i].matching = 1;
499                         continue;
500                 }
501
502                 if (rhs) {
503                         size_t rlen = strlen(++rhs);
504                         is_glob = (2 <= rlen && !strcmp(rhs + rlen - 2, "/*"));
505                         rs[i].dst = xstrndup(rhs, rlen - is_glob);
506                 }
507
508                 llen = (rhs ? (rhs - lhs - 1) : strlen(lhs));
509                 if (2 <= llen && !memcmp(lhs + llen - 2, "/*", 2)) {
510                         if ((rhs && !is_glob) || (!rhs && fetch))
511                                 goto invalid;
512                         is_glob = 1;
513                         llen--;
514                 } else if (rhs && is_glob) {
515                         goto invalid;
516                 }
517
518                 rs[i].pattern = is_glob;
519                 rs[i].src = xstrndup(lhs, llen);
520
521                 if (fetch) {
522                         /*
523                          * LHS
524                          * - empty is allowed; it means HEAD.
525                          * - otherwise it must be a valid looking ref.
526                          */
527                         if (!*rs[i].src)
528                                 ; /* empty is ok */
529                         else {
530                                 st = verify_refname(rs[i].src, is_glob);
531                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
532                                         goto invalid;
533                         }
534                         /*
535                          * RHS
536                          * - missing is ok, and is same as empty.
537                          * - empty is ok; it means not to store.
538                          * - otherwise it must be a valid looking ref.
539                          */
540                         if (!rs[i].dst) {
541                                 ; /* ok */
542                         } else if (!*rs[i].dst) {
543                                 ; /* ok */
544                         } else {
545                                 st = verify_refname(rs[i].dst, is_glob);
546                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
547                                         goto invalid;
548                         }
549                 } else {
550                         /*
551                          * LHS
552                          * - empty is allowed; it means delete.
553                          * - when wildcarded, it must be a valid looking ref.
554                          * - otherwise, it must be an extended SHA-1, but
555                          *   there is no existing way to validate this.
556                          */
557                         if (!*rs[i].src)
558                                 ; /* empty is ok */
559                         else if (is_glob) {
560                                 st = verify_refname(rs[i].src, is_glob);
561                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
562                                         goto invalid;
563                         }
564                         else
565                                 ; /* anything goes, for now */
566                         /*
567                          * RHS
568                          * - missing is allowed, but LHS then must be a
569                          *   valid looking ref.
570                          * - empty is not allowed.
571                          * - otherwise it must be a valid looking ref.
572                          */
573                         if (!rs[i].dst) {
574                                 st = verify_refname(rs[i].src, is_glob);
575                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
576                                         goto invalid;
577                         } else if (!*rs[i].dst) {
578                                 goto invalid;
579                         } else {
580                                 st = verify_refname(rs[i].dst, is_glob);
581                                 if (st && st != CHECK_REF_FORMAT_ONELEVEL)
582                                         goto invalid;
583                         }
584                 }
585         }
586         return rs;
587
588  invalid:
589         if (verify) {
590                 /*
591                  * nr_refspec must be greater than zero and i must be valid
592                  * since it is only possible to reach this point from within
593                  * the for loop above.
594                  */
595                 free_refspecs(rs, i+1);
596                 return NULL;
597         }
598         die("Invalid refspec '%s'", refspec[i]);
599 }
600
601 int valid_fetch_refspec(const char *fetch_refspec_str)
602 {
603         const char *fetch_refspec[] = { fetch_refspec_str };
604         struct refspec *refspec;
605
606         refspec = parse_refspec_internal(1, fetch_refspec, 1, 1);
607         free_refspecs(refspec, 1);
608         return !!refspec;
609 }
610
611 struct refspec *parse_fetch_refspec(int nr_refspec, const char **refspec)
612 {
613         return parse_refspec_internal(nr_refspec, refspec, 1, 0);
614 }
615
616 static struct refspec *parse_push_refspec(int nr_refspec, const char **refspec)
617 {
618         return parse_refspec_internal(nr_refspec, refspec, 0, 0);
619 }
620
621 static int valid_remote_nick(const char *name)
622 {
623         if (!name[0] || /* not empty */
624             (name[0] == '.' && /* not "." */
625              (!name[1] || /* not ".." */
626               (name[1] == '.' && !name[2]))))
627                 return 0;
628         return !strchr(name, '/'); /* no slash */
629 }
630
631 struct remote *remote_get(const char *name)
632 {
633         struct remote *ret;
634
635         read_config();
636         if (!name)
637                 name = default_remote_name;
638         ret = make_remote(name, 0);
639         if (valid_remote_nick(name)) {
640                 if (!ret->url)
641                         read_remotes_file(ret);
642                 if (!ret->url)
643                         read_branches_file(ret);
644         }
645         if (!ret->url)
646                 add_url_alias(ret, name);
647         if (!ret->url)
648                 return NULL;
649         ret->fetch = parse_fetch_refspec(ret->fetch_refspec_nr, ret->fetch_refspec);
650         ret->push = parse_push_refspec(ret->push_refspec_nr, ret->push_refspec);
651         return ret;
652 }
653
654 int for_each_remote(each_remote_fn fn, void *priv)
655 {
656         int i, result = 0;
657         read_config();
658         for (i = 0; i < remotes_nr && !result; i++) {
659                 struct remote *r = remotes[i];
660                 if (!r)
661                         continue;
662                 if (!r->fetch)
663                         r->fetch = parse_fetch_refspec(r->fetch_refspec_nr,
664                                                        r->fetch_refspec);
665                 if (!r->push)
666                         r->push = parse_push_refspec(r->push_refspec_nr,
667                                                      r->push_refspec);
668                 result = fn(r, priv);
669         }
670         return result;
671 }
672
673 void ref_remove_duplicates(struct ref *ref_map)
674 {
675         struct ref **posn;
676         struct ref *next;
677         for (; ref_map; ref_map = ref_map->next) {
678                 if (!ref_map->peer_ref)
679                         continue;
680                 posn = &ref_map->next;
681                 while (*posn) {
682                         if ((*posn)->peer_ref &&
683                             !strcmp((*posn)->peer_ref->name,
684                                     ref_map->peer_ref->name)) {
685                                 if (strcmp((*posn)->name, ref_map->name))
686                                         die("%s tracks both %s and %s",
687                                             ref_map->peer_ref->name,
688                                             (*posn)->name, ref_map->name);
689                                 next = (*posn)->next;
690                                 free((*posn)->peer_ref);
691                                 free(*posn);
692                                 *posn = next;
693                         } else {
694                                 posn = &(*posn)->next;
695                         }
696                 }
697         }
698 }
699
700 int remote_has_url(struct remote *remote, const char *url)
701 {
702         int i;
703         for (i = 0; i < remote->url_nr; i++) {
704                 if (!strcmp(remote->url[i], url))
705                         return 1;
706         }
707         return 0;
708 }
709
710 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
711 {
712         int find_src = refspec->src == NULL;
713         char *needle, **result;
714         int i;
715
716         if (find_src) {
717                 if (!refspec->dst)
718                         return error("find_tracking: need either src or dst");
719                 needle = refspec->dst;
720                 result = &refspec->src;
721         } else {
722                 needle = refspec->src;
723                 result = &refspec->dst;
724         }
725
726         for (i = 0; i < remote->fetch_refspec_nr; i++) {
727                 struct refspec *fetch = &remote->fetch[i];
728                 const char *key = find_src ? fetch->dst : fetch->src;
729                 const char *value = find_src ? fetch->src : fetch->dst;
730                 if (!fetch->dst)
731                         continue;
732                 if (fetch->pattern) {
733                         if (!prefixcmp(needle, key)) {
734                                 *result = xmalloc(strlen(value) +
735                                                   strlen(needle) -
736                                                   strlen(key) + 1);
737                                 strcpy(*result, value);
738                                 strcpy(*result + strlen(value),
739                                        needle + strlen(key));
740                                 refspec->force = fetch->force;
741                                 return 0;
742                         }
743                 } else if (!strcmp(needle, key)) {
744                         *result = xstrdup(value);
745                         refspec->force = fetch->force;
746                         return 0;
747                 }
748         }
749         return -1;
750 }
751
752 struct ref *alloc_ref(unsigned namelen)
753 {
754         struct ref *ret = xcalloc(1, sizeof(struct ref) + namelen);
755         return ret;
756 }
757
758 struct ref *alloc_ref_from_str(const char* str)
759 {
760         struct ref *ret = alloc_ref(strlen(str) + 1);
761         strcpy(ret->name, str);
762         return ret;
763 }
764
765 static struct ref *copy_ref(const struct ref *ref)
766 {
767         struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
768         memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
769         ret->next = NULL;
770         return ret;
771 }
772
773 struct ref *copy_ref_list(const struct ref *ref)
774 {
775         struct ref *ret = NULL;
776         struct ref **tail = &ret;
777         while (ref) {
778                 *tail = copy_ref(ref);
779                 ref = ref->next;
780                 tail = &((*tail)->next);
781         }
782         return ret;
783 }
784
785 static void free_ref(struct ref *ref)
786 {
787         if (!ref)
788                 return;
789         free(ref->remote_status);
790         free(ref->symref);
791         free(ref);
792 }
793
794 void free_refs(struct ref *ref)
795 {
796         struct ref *next;
797         while (ref) {
798                 next = ref->next;
799                 free(ref->peer_ref);
800                 free_ref(ref);
801                 ref = next;
802         }
803 }
804
805 static int count_refspec_match(const char *pattern,
806                                struct ref *refs,
807                                struct ref **matched_ref)
808 {
809         int patlen = strlen(pattern);
810         struct ref *matched_weak = NULL;
811         struct ref *matched = NULL;
812         int weak_match = 0;
813         int match = 0;
814
815         for (weak_match = match = 0; refs; refs = refs->next) {
816                 char *name = refs->name;
817                 int namelen = strlen(name);
818
819                 if (!refname_match(pattern, name, ref_rev_parse_rules))
820                         continue;
821
822                 /* A match is "weak" if it is with refs outside
823                  * heads or tags, and did not specify the pattern
824                  * in full (e.g. "refs/remotes/origin/master") or at
825                  * least from the toplevel (e.g. "remotes/origin/master");
826                  * otherwise "git push $URL master" would result in
827                  * ambiguity between remotes/origin/master and heads/master
828                  * at the remote site.
829                  */
830                 if (namelen != patlen &&
831                     patlen != namelen - 5 &&
832                     prefixcmp(name, "refs/heads/") &&
833                     prefixcmp(name, "refs/tags/")) {
834                         /* We want to catch the case where only weak
835                          * matches are found and there are multiple
836                          * matches, and where more than one strong
837                          * matches are found, as ambiguous.  One
838                          * strong match with zero or more weak matches
839                          * are acceptable as a unique match.
840                          */
841                         matched_weak = refs;
842                         weak_match++;
843                 }
844                 else {
845                         matched = refs;
846                         match++;
847                 }
848         }
849         if (!matched) {
850                 *matched_ref = matched_weak;
851                 return weak_match;
852         }
853         else {
854                 *matched_ref = matched;
855                 return match;
856         }
857 }
858
859 static void tail_link_ref(struct ref *ref, struct ref ***tail)
860 {
861         **tail = ref;
862         while (ref->next)
863                 ref = ref->next;
864         *tail = &ref->next;
865 }
866
867 static struct ref *try_explicit_object_name(const char *name)
868 {
869         unsigned char sha1[20];
870         struct ref *ref;
871
872         if (!*name) {
873                 ref = alloc_ref(20);
874                 strcpy(ref->name, "(delete)");
875                 hashclr(ref->new_sha1);
876                 return ref;
877         }
878         if (get_sha1(name, sha1))
879                 return NULL;
880         ref = alloc_ref_from_str(name);
881         hashcpy(ref->new_sha1, sha1);
882         return ref;
883 }
884
885 static struct ref *make_linked_ref(const char *name, struct ref ***tail)
886 {
887         struct ref *ret = alloc_ref_from_str(name);
888         tail_link_ref(ret, tail);
889         return ret;
890 }
891
892 static char *guess_ref(const char *name, struct ref *peer)
893 {
894         struct strbuf buf = STRBUF_INIT;
895         unsigned char sha1[20];
896
897         const char *r = resolve_ref(peer->name, sha1, 1, NULL);
898         if (!r)
899                 return NULL;
900
901         if (!prefixcmp(r, "refs/heads/"))
902                 strbuf_addstr(&buf, "refs/heads/");
903         else if (!prefixcmp(r, "refs/tags/"))
904                 strbuf_addstr(&buf, "refs/tags/");
905         else
906                 return NULL;
907
908         strbuf_addstr(&buf, name);
909         return strbuf_detach(&buf, NULL);
910 }
911
912 static int match_explicit(struct ref *src, struct ref *dst,
913                           struct ref ***dst_tail,
914                           struct refspec *rs)
915 {
916         struct ref *matched_src, *matched_dst;
917
918         const char *dst_value = rs->dst;
919         char *dst_guess;
920
921         if (rs->pattern || rs->matching)
922                 return 0;
923
924         matched_src = matched_dst = NULL;
925         switch (count_refspec_match(rs->src, src, &matched_src)) {
926         case 1:
927                 break;
928         case 0:
929                 /* The source could be in the get_sha1() format
930                  * not a reference name.  :refs/other is a
931                  * way to delete 'other' ref at the remote end.
932                  */
933                 matched_src = try_explicit_object_name(rs->src);
934                 if (!matched_src)
935                         return error("src refspec %s does not match any.", rs->src);
936                 break;
937         default:
938                 return error("src refspec %s matches more than one.", rs->src);
939         }
940
941         if (!dst_value) {
942                 unsigned char sha1[20];
943                 int flag;
944
945                 dst_value = resolve_ref(matched_src->name, sha1, 1, &flag);
946                 if (!dst_value ||
947                     ((flag & REF_ISSYMREF) &&
948                      prefixcmp(dst_value, "refs/heads/")))
949                         die("%s cannot be resolved to branch.",
950                             matched_src->name);
951         }
952
953         switch (count_refspec_match(dst_value, dst, &matched_dst)) {
954         case 1:
955                 break;
956         case 0:
957                 if (!memcmp(dst_value, "refs/", 5))
958                         matched_dst = make_linked_ref(dst_value, dst_tail);
959                 else if((dst_guess = guess_ref(dst_value, matched_src)))
960                         matched_dst = make_linked_ref(dst_guess, dst_tail);
961                 else
962                         error("unable to push to unqualified destination: %s\n"
963                               "The destination refspec neither matches an "
964                               "existing ref on the remote nor\n"
965                               "begins with refs/, and we are unable to "
966                               "guess a prefix based on the source ref.",
967                               dst_value);
968                 break;
969         default:
970                 matched_dst = NULL;
971                 error("dst refspec %s matches more than one.",
972                       dst_value);
973                 break;
974         }
975         if (!matched_dst)
976                 return -1;
977         if (matched_dst->peer_ref)
978                 return error("dst ref %s receives from more than one src.",
979                       matched_dst->name);
980         else {
981                 matched_dst->peer_ref = matched_src;
982                 matched_dst->force = rs->force;
983         }
984         return 0;
985 }
986
987 static int match_explicit_refs(struct ref *src, struct ref *dst,
988                                struct ref ***dst_tail, struct refspec *rs,
989                                int rs_nr)
990 {
991         int i, errs;
992         for (i = errs = 0; i < rs_nr; i++)
993                 errs += match_explicit(src, dst, dst_tail, &rs[i]);
994         return errs;
995 }
996
997 static const struct refspec *check_pattern_match(const struct refspec *rs,
998                                                  int rs_nr,
999                                                  const struct ref *src)
1000 {
1001         int i;
1002         int matching_refs = -1;
1003         for (i = 0; i < rs_nr; i++) {
1004                 if (rs[i].matching &&
1005                     (matching_refs == -1 || rs[i].force)) {
1006                         matching_refs = i;
1007                         continue;
1008                 }
1009
1010                 if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
1011                         return rs + i;
1012         }
1013         if (matching_refs != -1)
1014                 return rs + matching_refs;
1015         else
1016                 return NULL;
1017 }
1018
1019 /*
1020  * Note. This is used only by "push"; refspec matching rules for
1021  * push and fetch are subtly different, so do not try to reuse it
1022  * without thinking.
1023  */
1024 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
1025                int nr_refspec, const char **refspec, int flags)
1026 {
1027         struct refspec *rs;
1028         int send_all = flags & MATCH_REFS_ALL;
1029         int send_mirror = flags & MATCH_REFS_MIRROR;
1030         static const char *default_refspec[] = { ":", 0 };
1031
1032         if (!nr_refspec) {
1033                 nr_refspec = 1;
1034                 refspec = default_refspec;
1035         }
1036         rs = parse_push_refspec(nr_refspec, (const char **) refspec);
1037         if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
1038                 return -1;
1039
1040         /* pick the remainder */
1041         for ( ; src; src = src->next) {
1042                 struct ref *dst_peer;
1043                 const struct refspec *pat = NULL;
1044                 char *dst_name;
1045                 if (src->peer_ref)
1046                         continue;
1047
1048                 pat = check_pattern_match(rs, nr_refspec, src);
1049                 if (!pat)
1050                         continue;
1051
1052                 if (pat->matching) {
1053                         /*
1054                          * "matching refs"; traditionally we pushed everything
1055                          * including refs outside refs/heads/ hierarchy, but
1056                          * that does not make much sense these days.
1057                          */
1058                         if (!send_mirror && prefixcmp(src->name, "refs/heads/"))
1059                                 continue;
1060                         dst_name = xstrdup(src->name);
1061
1062                 } else {
1063                         const char *dst_side = pat->dst ? pat->dst : pat->src;
1064                         dst_name = xmalloc(strlen(dst_side) +
1065                                            strlen(src->name) -
1066                                            strlen(pat->src) + 2);
1067                         strcpy(dst_name, dst_side);
1068                         strcat(dst_name, src->name + strlen(pat->src));
1069                 }
1070                 dst_peer = find_ref_by_name(dst, dst_name);
1071                 if (dst_peer) {
1072                         if (dst_peer->peer_ref)
1073                                 /* We're already sending something to this ref. */
1074                                 goto free_name;
1075
1076                 } else {
1077                         if (pat->matching && !(send_all || send_mirror))
1078                                 /*
1079                                  * Remote doesn't have it, and we have no
1080                                  * explicit pattern, and we don't have
1081                                  * --all nor --mirror.
1082                                  */
1083                                 goto free_name;
1084
1085                         /* Create a new one and link it */
1086                         dst_peer = make_linked_ref(dst_name, dst_tail);
1087                         hashcpy(dst_peer->new_sha1, src->new_sha1);
1088                 }
1089                 dst_peer->peer_ref = src;
1090                 dst_peer->force = pat->force;
1091         free_name:
1092                 free(dst_name);
1093         }
1094         return 0;
1095 }
1096
1097 struct branch *branch_get(const char *name)
1098 {
1099         struct branch *ret;
1100
1101         read_config();
1102         if (!name || !*name || !strcmp(name, "HEAD"))
1103                 ret = current_branch;
1104         else
1105                 ret = make_branch(name, 0);
1106         if (ret && ret->remote_name) {
1107                 ret->remote = remote_get(ret->remote_name);
1108                 if (ret->merge_nr) {
1109                         int i;
1110                         ret->merge = xcalloc(sizeof(*ret->merge),
1111                                              ret->merge_nr);
1112                         for (i = 0; i < ret->merge_nr; i++) {
1113                                 ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
1114                                 ret->merge[i]->src = xstrdup(ret->merge_name[i]);
1115                                 remote_find_tracking(ret->remote,
1116                                                      ret->merge[i]);
1117                         }
1118                 }
1119         }
1120         return ret;
1121 }
1122
1123 int branch_has_merge_config(struct branch *branch)
1124 {
1125         return branch && !!branch->merge;
1126 }
1127
1128 int branch_merge_matches(struct branch *branch,
1129                                  int i,
1130                                  const char *refname)
1131 {
1132         if (!branch || i < 0 || i >= branch->merge_nr)
1133                 return 0;
1134         return refname_match(branch->merge[i]->src, refname, ref_fetch_rules);
1135 }
1136
1137 static struct ref *get_expanded_map(const struct ref *remote_refs,
1138                                     const struct refspec *refspec)
1139 {
1140         const struct ref *ref;
1141         struct ref *ret = NULL;
1142         struct ref **tail = &ret;
1143
1144         int remote_prefix_len = strlen(refspec->src);
1145         int local_prefix_len = strlen(refspec->dst);
1146
1147         for (ref = remote_refs; ref; ref = ref->next) {
1148                 if (strchr(ref->name, '^'))
1149                         continue; /* a dereference item */
1150                 if (!prefixcmp(ref->name, refspec->src)) {
1151                         const char *match;
1152                         struct ref *cpy = copy_ref(ref);
1153                         match = ref->name + remote_prefix_len;
1154
1155                         cpy->peer_ref = alloc_ref(local_prefix_len +
1156                                                   strlen(match) + 1);
1157                         sprintf(cpy->peer_ref->name, "%s%s",
1158                                 refspec->dst, match);
1159                         if (refspec->force)
1160                                 cpy->peer_ref->force = 1;
1161                         *tail = cpy;
1162                         tail = &cpy->next;
1163                 }
1164         }
1165
1166         return ret;
1167 }
1168
1169 static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
1170 {
1171         const struct ref *ref;
1172         for (ref = refs; ref; ref = ref->next) {
1173                 if (refname_match(name, ref->name, ref_fetch_rules))
1174                         return ref;
1175         }
1176         return NULL;
1177 }
1178
1179 struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
1180 {
1181         const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
1182
1183         if (!ref)
1184                 return NULL;
1185
1186         return copy_ref(ref);
1187 }
1188
1189 static struct ref *get_local_ref(const char *name)
1190 {
1191         struct ref *ret;
1192         if (!name)
1193                 return NULL;
1194
1195         if (!prefixcmp(name, "refs/")) {
1196                 return alloc_ref_from_str(name);
1197         }
1198
1199         if (!prefixcmp(name, "heads/") ||
1200             !prefixcmp(name, "tags/") ||
1201             !prefixcmp(name, "remotes/")) {
1202                 ret = alloc_ref(strlen(name) + 6);
1203                 sprintf(ret->name, "refs/%s", name);
1204                 return ret;
1205         }
1206
1207         ret = alloc_ref(strlen(name) + 12);
1208         sprintf(ret->name, "refs/heads/%s", name);
1209         return ret;
1210 }
1211
1212 int get_fetch_map(const struct ref *remote_refs,
1213                   const struct refspec *refspec,
1214                   struct ref ***tail,
1215                   int missing_ok)
1216 {
1217         struct ref *ref_map, **rmp;
1218
1219         if (refspec->pattern) {
1220                 ref_map = get_expanded_map(remote_refs, refspec);
1221         } else {
1222                 const char *name = refspec->src[0] ? refspec->src : "HEAD";
1223
1224                 ref_map = get_remote_ref(remote_refs, name);
1225                 if (!missing_ok && !ref_map)
1226                         die("Couldn't find remote ref %s", name);
1227                 if (ref_map) {
1228                         ref_map->peer_ref = get_local_ref(refspec->dst);
1229                         if (ref_map->peer_ref && refspec->force)
1230                                 ref_map->peer_ref->force = 1;
1231                 }
1232         }
1233
1234         for (rmp = &ref_map; *rmp; ) {
1235                 if ((*rmp)->peer_ref) {
1236                         int st = check_ref_format((*rmp)->peer_ref->name + 5);
1237                         if (st && st != CHECK_REF_FORMAT_ONELEVEL) {
1238                                 struct ref *ignore = *rmp;
1239                                 error("* Ignoring funny ref '%s' locally",
1240                                       (*rmp)->peer_ref->name);
1241                                 *rmp = (*rmp)->next;
1242                                 free(ignore->peer_ref);
1243                                 free(ignore);
1244                                 continue;
1245                         }
1246                 }
1247                 rmp = &((*rmp)->next);
1248         }
1249
1250         if (ref_map)
1251                 tail_link_ref(ref_map, tail);
1252
1253         return 0;
1254 }
1255
1256 int resolve_remote_symref(struct ref *ref, struct ref *list)
1257 {
1258         if (!ref->symref)
1259                 return 0;
1260         for (; list; list = list->next)
1261                 if (!strcmp(ref->symref, list->name)) {
1262                         hashcpy(ref->old_sha1, list->old_sha1);
1263                         return 0;
1264                 }
1265         return 1;
1266 }
1267
1268 /*
1269  * Return true if there is anything to report, otherwise false.
1270  */
1271 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
1272 {
1273         unsigned char sha1[20];
1274         struct commit *ours, *theirs;
1275         char symmetric[84];
1276         struct rev_info revs;
1277         const char *rev_argv[10], *base;
1278         int rev_argc;
1279
1280         /*
1281          * Nothing to report unless we are marked to build on top of
1282          * somebody else.
1283          */
1284         if (!branch ||
1285             !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
1286                 return 0;
1287
1288         /*
1289          * If what we used to build on no longer exists, there is
1290          * nothing to report.
1291          */
1292         base = branch->merge[0]->dst;
1293         if (!resolve_ref(base, sha1, 1, NULL))
1294                 return 0;
1295         theirs = lookup_commit(sha1);
1296         if (!theirs)
1297                 return 0;
1298
1299         if (!resolve_ref(branch->refname, sha1, 1, NULL))
1300                 return 0;
1301         ours = lookup_commit(sha1);
1302         if (!ours)
1303                 return 0;
1304
1305         /* are we the same? */
1306         if (theirs == ours)
1307                 return 0;
1308
1309         /* Run "rev-list --left-right ours...theirs" internally... */
1310         rev_argc = 0;
1311         rev_argv[rev_argc++] = NULL;
1312         rev_argv[rev_argc++] = "--left-right";
1313         rev_argv[rev_argc++] = symmetric;
1314         rev_argv[rev_argc++] = "--";
1315         rev_argv[rev_argc] = NULL;
1316
1317         strcpy(symmetric, sha1_to_hex(ours->object.sha1));
1318         strcpy(symmetric + 40, "...");
1319         strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
1320
1321         init_revisions(&revs, NULL);
1322         setup_revisions(rev_argc, rev_argv, &revs, NULL);
1323         prepare_revision_walk(&revs);
1324
1325         /* ... and count the commits on each side. */
1326         *num_ours = 0;
1327         *num_theirs = 0;
1328         while (1) {
1329                 struct commit *c = get_revision(&revs);
1330                 if (!c)
1331                         break;
1332                 if (c->object.flags & SYMMETRIC_LEFT)
1333                         (*num_ours)++;
1334                 else
1335                         (*num_theirs)++;
1336         }
1337
1338         /* clear object flags smudged by the above traversal */
1339         clear_commit_marks(ours, ALL_REV_FLAGS);
1340         clear_commit_marks(theirs, ALL_REV_FLAGS);
1341         return 1;
1342 }
1343
1344 /*
1345  * Return true when there is anything to report, otherwise false.
1346  */
1347 int format_tracking_info(struct branch *branch, struct strbuf *sb)
1348 {
1349         int num_ours, num_theirs;
1350         const char *base;
1351
1352         if (!stat_tracking_info(branch, &num_ours, &num_theirs))
1353                 return 0;
1354
1355         base = branch->merge[0]->dst;
1356         if (!prefixcmp(base, "refs/remotes/")) {
1357                 base += strlen("refs/remotes/");
1358         }
1359         if (!num_theirs)
1360                 strbuf_addf(sb, "Your branch is ahead of '%s' "
1361                             "by %d commit%s.\n",
1362                             base, num_ours, (num_ours == 1) ? "" : "s");
1363         else if (!num_ours)
1364                 strbuf_addf(sb, "Your branch is behind '%s' "
1365                             "by %d commit%s, "
1366                             "and can be fast-forwarded.\n",
1367                             base, num_theirs, (num_theirs == 1) ? "" : "s");
1368         else
1369                 strbuf_addf(sb, "Your branch and '%s' have diverged,\n"
1370                             "and have %d and %d different commit(s) each, "
1371                             "respectively.\n",
1372                             base, num_ours, num_theirs);
1373         return 1;
1374 }