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Introduce an unlink(2) wrapper which gives warning if unlink failed
[git.git] / builtin-fetch.c
1 /*
2  * "git fetch"
3  */
4 #include "cache.h"
5 #include "refs.h"
6 #include "commit.h"
7 #include "builtin.h"
8 #include "string-list.h"
9 #include "remote.h"
10 #include "transport.h"
11 #include "run-command.h"
12 #include "parse-options.h"
13 #include "sigchain.h"
15 static const char * const builtin_fetch_usage[] = {
16         "git fetch [options] [<repository> <refspec>...]",
17         NULL
18 };
20 enum {
21         TAGS_UNSET = 0,
22         TAGS_DEFAULT = 1,
23         TAGS_SET = 2
24 };
26 static int append, force, keep, update_head_ok, verbosity;
27 static int tags = TAGS_DEFAULT;
28 static const char *depth;
29 static const char *upload_pack;
30 static struct strbuf default_rla = STRBUF_INIT;
31 static struct transport *transport;
33 static struct option builtin_fetch_options[] = {
34         OPT__VERBOSITY(&verbosity),
35         OPT_BOOLEAN('a', "append", &append,
36                     "append to .git/FETCH_HEAD instead of overwriting"),
37         OPT_STRING(0, "upload-pack", &upload_pack, "PATH",
38                    "path to upload pack on remote end"),
39         OPT_BOOLEAN('f', "force", &force,
40                     "force overwrite of local branch"),
41         OPT_SET_INT('t', "tags", &tags,
42                     "fetch all tags and associated objects", TAGS_SET),
43         OPT_SET_INT('n', NULL, &tags,
44                     "do not fetch all tags (--no-tags)", TAGS_UNSET),
45         OPT_BOOLEAN('k', "keep", &keep, "keep downloaded pack"),
46         OPT_BOOLEAN('u', "update-head-ok", &update_head_ok,
47                     "allow updating of HEAD ref"),
48         OPT_STRING(0, "depth", &depth, "DEPTH",
49                    "deepen history of shallow clone"),
50         OPT_END()
51 };
53 static void unlock_pack(void)
54 {
55         if (transport)
56                 transport_unlock_pack(transport);
57 }
59 static void unlock_pack_on_signal(int signo)
60 {
61         unlock_pack();
62         sigchain_pop(signo);
63         raise(signo);
64 }
66 static void add_merge_config(struct ref **head,
67                            const struct ref *remote_refs,
68                            struct branch *branch,
69                            struct ref ***tail)
70 {
71         int i;
73         for (i = 0; i < branch->merge_nr; i++) {
74                 struct ref *rm, **old_tail = *tail;
75                 struct refspec refspec;
77                 for (rm = *head; rm; rm = rm->next) {
78                         if (branch_merge_matches(branch, i, rm->name)) {
79                                 rm->merge = 1;
80                                 break;
81                         }
82                 }
83                 if (rm)
84                         continue;
86                 /*
87                  * Not fetched to a tracking branch?  We need to fetch
88                  * it anyway to allow this branch's "branch.$name.merge"
89                  * to be honored by 'git pull', but we do not have to
90                  * fail if branch.$name.merge is misconfigured to point
91                  * at a nonexisting branch.  If we were indeed called by
92                  * 'git pull', it will notice the misconfiguration because
93                  * there is no entry in the resulting FETCH_HEAD marked
94                  * for merging.
95                  */
96                 refspec.src = branch->merge[i]->src;
97                 refspec.dst = NULL;
98                 refspec.pattern = 0;
99                 refspec.force = 0;
100                 get_fetch_map(remote_refs, &refspec, tail, 1);
101                 for (rm = *old_tail; rm; rm = rm->next)
102                         rm->merge = 1;
103         }
106 static void find_non_local_tags(struct transport *transport,
107                         struct ref **head,
108                         struct ref ***tail);
110 static struct ref *get_ref_map(struct transport *transport,
111                                struct refspec *refs, int ref_count, int tags,
112                                int *autotags)
114         int i;
115         struct ref *rm;
116         struct ref *ref_map = NULL;
117         struct ref **tail = &ref_map;
119         const struct ref *remote_refs = transport_get_remote_refs(transport);
121         if (ref_count || tags == TAGS_SET) {
122                 for (i = 0; i < ref_count; i++) {
123                         get_fetch_map(remote_refs, &refs[i], &tail, 0);
124                         if (refs[i].dst && refs[i].dst[0])
125                                 *autotags = 1;
126                 }
127                 /* Merge everything on the command line, but not --tags */
128                 for (rm = ref_map; rm; rm = rm->next)
129                         rm->merge = 1;
130                 if (tags == TAGS_SET)
131                         get_fetch_map(remote_refs, tag_refspec, &tail, 0);
132         } else {
133                 /* Use the defaults */
134                 struct remote *remote = transport->remote;
135                 struct branch *branch = branch_get(NULL);
136                 int has_merge = branch_has_merge_config(branch);
137                 if (remote && (remote->fetch_refspec_nr || has_merge)) {
138                         for (i = 0; i < remote->fetch_refspec_nr; i++) {
139                                 get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
140                                 if (remote->fetch[i].dst &&
141                                     remote->fetch[i].dst[0])
142                                         *autotags = 1;
143                                 if (!i && !has_merge && ref_map &&
144                                     !remote->fetch[0].pattern)
145                                         ref_map->merge = 1;
146                         }
147                         /*
148                          * if the remote we're fetching from is the same
149                          * as given in branch.<name>.remote, we add the
150                          * ref given in branch.<name>.merge, too.
151                          */
152                         if (has_merge &&
153                             !strcmp(branch->remote_name, remote->name))
154                                 add_merge_config(&ref_map, remote_refs, branch, &tail);
155                 } else {
156                         ref_map = get_remote_ref(remote_refs, "HEAD");
157                         if (!ref_map)
158                                 die("Couldn't find remote ref HEAD");
159                         ref_map->merge = 1;
160                         tail = &ref_map->next;
161                 }
162         }
163         if (tags == TAGS_DEFAULT && *autotags)
164                 find_non_local_tags(transport, &ref_map, &tail);
165         ref_remove_duplicates(ref_map);
167         return ref_map;
170 static int s_update_ref(const char *action,
171                         struct ref *ref,
172                         int check_old)
174         char msg[1024];
175         char *rla = getenv("GIT_REFLOG_ACTION");
176         static struct ref_lock *lock;
178         if (!rla)
179                 rla = default_rla.buf;
180         snprintf(msg, sizeof(msg), "%s: %s", rla, action);
181         lock = lock_any_ref_for_update(ref->name,
182                                        check_old ? ref->old_sha1 : NULL, 0);
183         if (!lock)
184                 return 2;
185         if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
186                 return 2;
187         return 0;
190 #define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
191 #define REFCOL_WIDTH  10
193 static int update_local_ref(struct ref *ref,
194                             const char *remote,
195                             char *display)
197         struct commit *current = NULL, *updated;
198         enum object_type type;
199         struct branch *current_branch = branch_get(NULL);
200         const char *pretty_ref = prettify_ref(ref);
202         *display = 0;
203         type = sha1_object_info(ref->new_sha1, NULL);
204         if (type < 0)
205                 die("object %s not found", sha1_to_hex(ref->new_sha1));
207         if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
208                 if (verbosity > 0)
209                         sprintf(display, "= %-*s %-*s -> %s", SUMMARY_WIDTH,
210                                 "[up to date]", REFCOL_WIDTH, remote,
211                                 pretty_ref);
212                 return 0;
213         }
215         if (current_branch &&
216             !strcmp(ref->name, current_branch->name) &&
217             !(update_head_ok || is_bare_repository()) &&
218             !is_null_sha1(ref->old_sha1)) {
219                 /*
220                  * If this is the head, and it's not okay to update
221                  * the head, and the old value of the head isn't empty...
222                  */
223                 sprintf(display, "! %-*s %-*s -> %s  (can't fetch in current branch)",
224                         SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
225                         pretty_ref);
226                 return 1;
227         }
229         if (!is_null_sha1(ref->old_sha1) &&
230             !prefixcmp(ref->name, "refs/tags/")) {
231                 int r;
232                 r = s_update_ref("updating tag", ref, 0);
233                 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '-',
234                         SUMMARY_WIDTH, "[tag update]", REFCOL_WIDTH, remote,
235                         pretty_ref, r ? "  (unable to update local ref)" : "");
236                 return r;
237         }
239         current = lookup_commit_reference_gently(ref->old_sha1, 1);
240         updated = lookup_commit_reference_gently(ref->new_sha1, 1);
241         if (!current || !updated) {
242                 const char *msg;
243                 const char *what;
244                 int r;
245                 if (!strncmp(ref->name, "refs/tags/", 10)) {
246                         msg = "storing tag";
247                         what = "[new tag]";
248                 }
249                 else {
250                         msg = "storing head";
251                         what = "[new branch]";
252                 }
254                 r = s_update_ref(msg, ref, 0);
255                 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '*',
256                         SUMMARY_WIDTH, what, REFCOL_WIDTH, remote, pretty_ref,
257                         r ? "  (unable to update local ref)" : "");
258                 return r;
259         }
261         if (in_merge_bases(current, &updated, 1)) {
262                 char quickref[83];
263                 int r;
264                 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
265                 strcat(quickref, "..");
266                 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
267                 r = s_update_ref("fast forward", ref, 1);
268                 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : ' ',
269                         SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
270                         pretty_ref, r ? "  (unable to update local ref)" : "");
271                 return r;
272         } else if (force || ref->force) {
273                 char quickref[84];
274                 int r;
275                 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
276                 strcat(quickref, "...");
277                 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
278                 r = s_update_ref("forced-update", ref, 1);
279                 sprintf(display, "%c %-*s %-*s -> %s  (%s)", r ? '!' : '+',
280                         SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
281                         pretty_ref,
282                         r ? "unable to update local ref" : "forced update");
283                 return r;
284         } else {
285                 sprintf(display, "! %-*s %-*s -> %s  (non fast forward)",
286                         SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
287                         pretty_ref);
288                 return 1;
289         }
292 static int store_updated_refs(const char *url, const char *remote_name,
293                 struct ref *ref_map)
295         FILE *fp;
296         struct commit *commit;
297         int url_len, i, note_len, shown_url = 0, rc = 0;
298         char note[1024];
299         const char *what, *kind;
300         struct ref *rm;
301         char *filename = git_path("FETCH_HEAD");
303         fp = fopen(filename, "a");
304         if (!fp)
305                 return error("cannot open %s: %s\n", filename, strerror(errno));
306         for (rm = ref_map; rm; rm = rm->next) {
307                 struct ref *ref = NULL;
309                 if (rm->peer_ref) {
310                         ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
311                         strcpy(ref->name, rm->peer_ref->name);
312                         hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
313                         hashcpy(ref->new_sha1, rm->old_sha1);
314                         ref->force = rm->peer_ref->force;
315                 }
317                 commit = lookup_commit_reference_gently(rm->old_sha1, 1);
318                 if (!commit)
319                         rm->merge = 0;
321                 if (!strcmp(rm->name, "HEAD")) {
322                         kind = "";
323                         what = "";
324                 }
325                 else if (!prefixcmp(rm->name, "refs/heads/")) {
326                         kind = "branch";
327                         what = rm->name + 11;
328                 }
329                 else if (!prefixcmp(rm->name, "refs/tags/")) {
330                         kind = "tag";
331                         what = rm->name + 10;
332                 }
333                 else if (!prefixcmp(rm->name, "refs/remotes/")) {
334                         kind = "remote branch";
335                         what = rm->name + 13;
336                 }
337                 else {
338                         kind = "";
339                         what = rm->name;
340                 }
342                 url_len = strlen(url);
343                 for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
344                         ;
345                 url_len = i + 1;
346                 if (4 < i && !strncmp(".git", url + i - 3, 4))
347                         url_len = i - 3;
349                 note_len = 0;
350                 if (*what) {
351                         if (*kind)
352                                 note_len += sprintf(note + note_len, "%s ",
353                                                     kind);
354                         note_len += sprintf(note + note_len, "'%s' of ", what);
355                 }
356                 note_len += sprintf(note + note_len, "%.*s", url_len, url);
357                 fprintf(fp, "%s\t%s\t%s\n",
358                         sha1_to_hex(commit ? commit->object.sha1 :
359                                     rm->old_sha1),
360                         rm->merge ? "" : "not-for-merge",
361                         note);
363                 if (ref)
364                         rc |= update_local_ref(ref, what, note);
365                 else
366                         sprintf(note, "* %-*s %-*s -> FETCH_HEAD",
367                                 SUMMARY_WIDTH, *kind ? kind : "branch",
368                                  REFCOL_WIDTH, *what ? what : "HEAD");
369                 if (*note) {
370                         if (verbosity >= 0 && !shown_url) {
371                                 fprintf(stderr, "From %.*s\n",
372                                                 url_len, url);
373                                 shown_url = 1;
374                         }
375                         if (verbosity >= 0)
376                                 fprintf(stderr, " %s\n", note);
377                 }
378         }
379         fclose(fp);
380         if (rc & 2)
381                 error("some local refs could not be updated; try running\n"
382                       " 'git remote prune %s' to remove any old, conflicting "
383                       "branches", remote_name);
384         return rc;
387 /*
388  * We would want to bypass the object transfer altogether if
389  * everything we are going to fetch already exists and connected
390  * locally.
391  *
392  * The refs we are going to fetch are in to_fetch (nr_heads in
393  * total).  If running
394  *
395  *  $ git rev-list --objects to_fetch[0] to_fetch[1] ... --not --all
396  *
397  * does not error out, that means everything reachable from the
398  * refs we are going to fetch exists and is connected to some of
399  * our existing refs.
400  */
401 static int quickfetch(struct ref *ref_map)
403         struct child_process revlist;
404         struct ref *ref;
405         char **argv;
406         int i, err;
408         /*
409          * If we are deepening a shallow clone we already have these
410          * objects reachable.  Running rev-list here will return with
411          * a good (0) exit status and we'll bypass the fetch that we
412          * really need to perform.  Claiming failure now will ensure
413          * we perform the network exchange to deepen our history.
414          */
415         if (depth)
416                 return -1;
418         for (i = 0, ref = ref_map; ref; ref = ref->next)
419                 i++;
420         if (!i)
421                 return 0;
423         argv = xmalloc(sizeof(*argv) * (i + 6));
424         i = 0;
425         argv[i++] = xstrdup("rev-list");
426         argv[i++] = xstrdup("--quiet");
427         argv[i++] = xstrdup("--objects");
428         for (ref = ref_map; ref; ref = ref->next)
429                 argv[i++] = xstrdup(sha1_to_hex(ref->old_sha1));
430         argv[i++] = xstrdup("--not");
431         argv[i++] = xstrdup("--all");
432         argv[i++] = NULL;
434         memset(&revlist, 0, sizeof(revlist));
435         revlist.argv = (const char**)argv;
436         revlist.git_cmd = 1;
437         revlist.no_stdin = 1;
438         revlist.no_stdout = 1;
439         revlist.no_stderr = 1;
440         err = run_command(&revlist);
442         for (i = 0; argv[i]; i++)
443                 free(argv[i]);
444         free(argv);
445         return err;
448 static int fetch_refs(struct transport *transport, struct ref *ref_map)
450         int ret = quickfetch(ref_map);
451         if (ret)
452                 ret = transport_fetch_refs(transport, ref_map);
453         if (!ret)
454                 ret |= store_updated_refs(transport->url,
455                                 transport->remote->name,
456                                 ref_map);
457         transport_unlock_pack(transport);
458         return ret;
461 static int add_existing(const char *refname, const unsigned char *sha1,
462                         int flag, void *cbdata)
464         struct string_list *list = (struct string_list *)cbdata;
465         string_list_insert(refname, list);
466         return 0;
469 static int will_fetch(struct ref **head, const unsigned char *sha1)
471         struct ref *rm = *head;
472         while (rm) {
473                 if (!hashcmp(rm->old_sha1, sha1))
474                         return 1;
475                 rm = rm->next;
476         }
477         return 0;
480 static void find_non_local_tags(struct transport *transport,
481                         struct ref **head,
482                         struct ref ***tail)
484         struct string_list existing_refs = { NULL, 0, 0, 0 };
485         struct string_list new_refs = { NULL, 0, 0, 1 };
486         char *ref_name;
487         int ref_name_len;
488         const unsigned char *ref_sha1;
489         const struct ref *tag_ref;
490         struct ref *rm = NULL;
491         const struct ref *ref;
493         for_each_ref(add_existing, &existing_refs);
494         for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
495                 if (prefixcmp(ref->name, "refs/tags"))
496                         continue;
498                 ref_name = xstrdup(ref->name);
499                 ref_name_len = strlen(ref_name);
500                 ref_sha1 = ref->old_sha1;
502                 if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
503                         ref_name[ref_name_len - 3] = 0;
504                         tag_ref = transport_get_remote_refs(transport);
505                         while (tag_ref) {
506                                 if (!strcmp(tag_ref->name, ref_name)) {
507                                         ref_sha1 = tag_ref->old_sha1;
508                                         break;
509                                 }
510                                 tag_ref = tag_ref->next;
511                         }
512                 }
514                 if (!string_list_has_string(&existing_refs, ref_name) &&
515                     !string_list_has_string(&new_refs, ref_name) &&
516                     (has_sha1_file(ref->old_sha1) ||
517                      will_fetch(head, ref->old_sha1))) {
518                         string_list_insert(ref_name, &new_refs);
520                         rm = alloc_ref(ref_name);
521                         rm->peer_ref = alloc_ref(ref_name);
522                         hashcpy(rm->old_sha1, ref_sha1);
524                         **tail = rm;
525                         *tail = &rm->next;
526                 }
527                 free(ref_name);
528         }
529         string_list_clear(&existing_refs, 0);
530         string_list_clear(&new_refs, 0);
533 static void check_not_current_branch(struct ref *ref_map)
535         struct branch *current_branch = branch_get(NULL);
537         if (is_bare_repository() || !current_branch)
538                 return;
540         for (; ref_map; ref_map = ref_map->next)
541                 if (ref_map->peer_ref && !strcmp(current_branch->refname,
542                                         ref_map->peer_ref->name))
543                         die("Refusing to fetch into current branch %s "
544                             "of non-bare repository", current_branch->refname);
547 static int do_fetch(struct transport *transport,
548                     struct refspec *refs, int ref_count)
550         struct ref *ref_map;
551         struct ref *rm;
552         int autotags = (transport->remote->fetch_tags == 1);
553         if (transport->remote->fetch_tags == 2 && tags != TAGS_UNSET)
554                 tags = TAGS_SET;
555         if (transport->remote->fetch_tags == -1)
556                 tags = TAGS_UNSET;
558         if (!transport->get_refs_list || !transport->fetch)
559                 die("Don't know how to fetch from %s", transport->url);
561         /* if not appending, truncate FETCH_HEAD */
562         if (!append) {
563                 char *filename = git_path("FETCH_HEAD");
564                 FILE *fp = fopen(filename, "w");
565                 if (!fp)
566                         return error("cannot open %s: %s\n", filename, strerror(errno));
567                 fclose(fp);
568         }
570         ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
571         if (!update_head_ok)
572                 check_not_current_branch(ref_map);
574         for (rm = ref_map; rm; rm = rm->next) {
575                 if (rm->peer_ref)
576                         read_ref(rm->peer_ref->name, rm->peer_ref->old_sha1);
577         }
579         if (tags == TAGS_DEFAULT && autotags)
580                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
581         if (fetch_refs(transport, ref_map)) {
582                 free_refs(ref_map);
583                 return 1;
584         }
585         free_refs(ref_map);
587         /* if neither --no-tags nor --tags was specified, do automated tag
588          * following ... */
589         if (tags == TAGS_DEFAULT && autotags) {
590                 struct ref **tail = &ref_map;
591                 ref_map = NULL;
592                 find_non_local_tags(transport, &ref_map, &tail);
593                 if (ref_map) {
594                         transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
595                         transport_set_option(transport, TRANS_OPT_DEPTH, "0");
596                         fetch_refs(transport, ref_map);
597                 }
598                 free_refs(ref_map);
599         }
601         return 0;
604 static void set_option(const char *name, const char *value)
606         int r = transport_set_option(transport, name, value);
607         if (r < 0)
608                 die("Option \"%s\" value \"%s\" is not valid for %s",
609                         name, value, transport->url);
610         if (r > 0)
611                 warning("Option \"%s\" is ignored for %s\n",
612                         name, transport->url);
615 int cmd_fetch(int argc, const char **argv, const char *prefix)
617         struct remote *remote;
618         int i;
619         static const char **refs = NULL;
620         int ref_nr = 0;
621         int exit_code;
623         /* Record the command line for the reflog */
624         strbuf_addstr(&default_rla, "fetch");
625         for (i = 1; i < argc; i++)
626                 strbuf_addf(&default_rla, " %s", argv[i]);
628         argc = parse_options(argc, argv,
629                              builtin_fetch_options, builtin_fetch_usage, 0);
631         if (argc == 0)
632                 remote = remote_get(NULL);
633         else
634                 remote = remote_get(argv[0]);
636         if (!remote)
637                 die("Where do you want to fetch from today?");
639         transport = transport_get(remote, remote->url[0]);
640         if (verbosity >= 2)
641                 transport->verbose = 1;
642         if (verbosity < 0)
643                 transport->verbose = -1;
644         if (upload_pack)
645                 set_option(TRANS_OPT_UPLOADPACK, upload_pack);
646         if (keep)
647                 set_option(TRANS_OPT_KEEP, "yes");
648         if (depth)
649                 set_option(TRANS_OPT_DEPTH, depth);
651         if (argc > 1) {
652                 int j = 0;
653                 refs = xcalloc(argc + 1, sizeof(const char *));
654                 for (i = 1; i < argc; i++) {
655                         if (!strcmp(argv[i], "tag")) {
656                                 char *ref;
657                                 i++;
658                                 if (i >= argc)
659                                         die("You need to specify a tag name.");
660                                 ref = xmalloc(strlen(argv[i]) * 2 + 22);
661                                 strcpy(ref, "refs/tags/");
662                                 strcat(ref, argv[i]);
663                                 strcat(ref, ":refs/tags/");
664                                 strcat(ref, argv[i]);
665                                 refs[j++] = ref;
666                         } else
667                                 refs[j++] = argv[i];
668                 }
669                 refs[j] = NULL;
670                 ref_nr = j;
671         }
673         sigchain_push_common(unlock_pack_on_signal);
674         atexit(unlock_pack);
675         exit_code = do_fetch(transport,
676                         parse_fetch_refspec(ref_nr, refs), ref_nr);
677         transport_disconnect(transport);
678         transport = NULL;
679         return exit_code;