receive-pack: detect aliased updates which can occur with symrefs
[git] / builtin-branch.c
1 /*
2  * Builtin "git branch"
3  *
4  * Copyright (c) 2006 Kristian Høgsberg <krh@redhat.com>
5  * Based on git-branch.sh by Junio C Hamano.
6  */
7
8 #include "cache.h"
9 #include "color.h"
10 #include "refs.h"
11 #include "commit.h"
12 #include "builtin.h"
13 #include "remote.h"
14 #include "parse-options.h"
15 #include "branch.h"
16 #include "diff.h"
17 #include "revision.h"
18
19 static const char * const builtin_branch_usage[] = {
20         "git branch [options] [-r | -a] [--merged | --no-merged]",
21         "git branch [options] [-l] [-f] <branchname> [<start-point>]",
22         "git branch [options] [-r] (-d | -D) <branchname>",
23         "git branch [options] (-m | -M) [<oldbranch>] <newbranch>",
24         NULL
25 };
26
27 #define REF_LOCAL_BRANCH    0x01
28 #define REF_REMOTE_BRANCH   0x02
29
30 static const char *head;
31 static unsigned char head_sha1[20];
32
33 static int branch_use_color = -1;
34 static char branch_colors[][COLOR_MAXLEN] = {
35         GIT_COLOR_RESET,
36         GIT_COLOR_NORMAL,       /* PLAIN */
37         GIT_COLOR_RED,          /* REMOTE */
38         GIT_COLOR_NORMAL,       /* LOCAL */
39         GIT_COLOR_GREEN,        /* CURRENT */
40 };
41 enum color_branch {
42         BRANCH_COLOR_RESET = 0,
43         BRANCH_COLOR_PLAIN = 1,
44         BRANCH_COLOR_REMOTE = 2,
45         BRANCH_COLOR_LOCAL = 3,
46         BRANCH_COLOR_CURRENT = 4,
47 };
48
49 static enum merge_filter {
50         NO_FILTER = 0,
51         SHOW_NOT_MERGED,
52         SHOW_MERGED,
53 } merge_filter;
54 static unsigned char merge_filter_ref[20];
55
56 static int parse_branch_color_slot(const char *var, int ofs)
57 {
58         if (!strcasecmp(var+ofs, "plain"))
59                 return BRANCH_COLOR_PLAIN;
60         if (!strcasecmp(var+ofs, "reset"))
61                 return BRANCH_COLOR_RESET;
62         if (!strcasecmp(var+ofs, "remote"))
63                 return BRANCH_COLOR_REMOTE;
64         if (!strcasecmp(var+ofs, "local"))
65                 return BRANCH_COLOR_LOCAL;
66         if (!strcasecmp(var+ofs, "current"))
67                 return BRANCH_COLOR_CURRENT;
68         return -1;
69 }
70
71 static int git_branch_config(const char *var, const char *value, void *cb)
72 {
73         if (!strcmp(var, "color.branch")) {
74                 branch_use_color = git_config_colorbool(var, value, -1);
75                 return 0;
76         }
77         if (!prefixcmp(var, "color.branch.")) {
78                 int slot = parse_branch_color_slot(var, 13);
79                 if (slot < 0)
80                         return 0;
81                 if (!value)
82                         return config_error_nonbool(var);
83                 color_parse(value, var, branch_colors[slot]);
84                 return 0;
85         }
86         return git_color_default_config(var, value, cb);
87 }
88
89 static const char *branch_get_color(enum color_branch ix)
90 {
91         if (branch_use_color > 0)
92                 return branch_colors[ix];
93         return "";
94 }
95
96 static int branch_merged(int kind, const char *name,
97                          struct commit *rev, struct commit *head_rev)
98 {
99         /*
100          * This checks whether the merge bases of branch and HEAD (or
101          * the other branch this branch builds upon) contains the
102          * branch, which means that the branch has already been merged
103          * safely to HEAD (or the other branch).
104          */
105         struct commit *reference_rev = NULL;
106         const char *reference_name = NULL;
107         int merged;
108
109         if (kind == REF_LOCAL_BRANCH) {
110                 struct branch *branch = branch_get(name);
111                 unsigned char sha1[20];
112
113                 if (branch &&
114                     branch->merge &&
115                     branch->merge[0] &&
116                     branch->merge[0]->dst &&
117                     (reference_name =
118                      resolve_ref(branch->merge[0]->dst, sha1, 1, NULL)) != NULL)
119                         reference_rev = lookup_commit_reference(sha1);
120         }
121         if (!reference_rev)
122                 reference_rev = head_rev;
123
124         merged = in_merge_bases(rev, &reference_rev, 1);
125
126         /*
127          * After the safety valve is fully redefined to "check with
128          * upstream, if any, otherwise with HEAD", we should just
129          * return the result of the in_merge_bases() above without
130          * any of the following code, but during the transition period,
131          * a gentle reminder is in order.
132          */
133         if ((head_rev != reference_rev) &&
134             in_merge_bases(rev, &head_rev, 1) != merged) {
135                 if (merged)
136                         warning("deleting branch '%s' that has been merged to\n"
137                                 "         '%s', but it is not yet merged to HEAD.",
138                                 name, reference_name);
139                 else
140                         warning("not deleting branch '%s' that is not yet merged to\n"
141                                 "         '%s', even though it is merged to HEAD.",
142                                 name, reference_name);
143         }
144         return merged;
145 }
146
147 static int delete_branches(int argc, const char **argv, int force, int kinds)
148 {
149         struct commit *rev, *head_rev = NULL;
150         unsigned char sha1[20];
151         char *name = NULL;
152         const char *fmt, *remote;
153         int i;
154         int ret = 0;
155         struct strbuf bname = STRBUF_INIT;
156
157         switch (kinds) {
158         case REF_REMOTE_BRANCH:
159                 fmt = "refs/remotes/%s";
160                 remote = "remote ";
161                 force = 1;
162                 break;
163         case REF_LOCAL_BRANCH:
164                 fmt = "refs/heads/%s";
165                 remote = "";
166                 break;
167         default:
168                 die("cannot use -a with -d");
169         }
170
171         if (!force) {
172                 head_rev = lookup_commit_reference(head_sha1);
173                 if (!head_rev)
174                         die("Couldn't look up commit object for HEAD");
175         }
176         for (i = 0; i < argc; i++, strbuf_release(&bname)) {
177                 strbuf_branchname(&bname, argv[i]);
178                 if (kinds == REF_LOCAL_BRANCH && !strcmp(head, bname.buf)) {
179                         error("Cannot delete the branch '%s' "
180                               "which you are currently on.", bname.buf);
181                         ret = 1;
182                         continue;
183                 }
184
185                 free(name);
186
187                 name = xstrdup(mkpath(fmt, bname.buf));
188                 if (!resolve_ref(name, sha1, 1, NULL)) {
189                         error("%sbranch '%s' not found.",
190                                         remote, bname.buf);
191                         ret = 1;
192                         continue;
193                 }
194
195                 rev = lookup_commit_reference(sha1);
196                 if (!rev) {
197                         error("Couldn't look up commit object for '%s'", name);
198                         ret = 1;
199                         continue;
200                 }
201
202                 if (!force && !branch_merged(kinds, bname.buf, rev, head_rev)) {
203                         error("The branch '%s' is not fully merged.\n"
204                               "If you are sure you want to delete it, "
205                               "run 'git branch -D %s'.", bname.buf, bname.buf);
206                         ret = 1;
207                         continue;
208                 }
209
210                 if (delete_ref(name, sha1, 0)) {
211                         error("Error deleting %sbranch '%s'", remote,
212                               bname.buf);
213                         ret = 1;
214                 } else {
215                         struct strbuf buf = STRBUF_INIT;
216                         printf("Deleted %sbranch %s (was %s).\n", remote,
217                                bname.buf,
218                                find_unique_abbrev(sha1, DEFAULT_ABBREV));
219                         strbuf_addf(&buf, "branch.%s", bname.buf);
220                         if (git_config_rename_section(buf.buf, NULL) < 0)
221                                 warning("Update of config-file failed");
222                         strbuf_release(&buf);
223                 }
224         }
225
226         free(name);
227
228         return(ret);
229 }
230
231 struct ref_item {
232         char *name;
233         char *dest;
234         unsigned int kind, len;
235         struct commit *commit;
236 };
237
238 struct ref_list {
239         struct rev_info revs;
240         int index, alloc, maxwidth, verbose, abbrev;
241         struct ref_item *list;
242         struct commit_list *with_commit;
243         int kinds;
244 };
245
246 static char *resolve_symref(const char *src, const char *prefix)
247 {
248         unsigned char sha1[20];
249         int flag;
250         const char *dst, *cp;
251
252         dst = resolve_ref(src, sha1, 0, &flag);
253         if (!(dst && (flag & REF_ISSYMREF)))
254                 return NULL;
255         if (prefix && (cp = skip_prefix(dst, prefix)))
256                 dst = cp;
257         return xstrdup(dst);
258 }
259
260 static int append_ref(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
261 {
262         struct ref_list *ref_list = (struct ref_list*)(cb_data);
263         struct ref_item *newitem;
264         struct commit *commit;
265         int kind, i;
266         const char *prefix, *orig_refname = refname;
267
268         static struct {
269                 int kind;
270                 const char *prefix;
271                 int pfxlen;
272         } ref_kind[] = {
273                 { REF_LOCAL_BRANCH, "refs/heads/", 11 },
274                 { REF_REMOTE_BRANCH, "refs/remotes/", 13 },
275         };
276
277         /* Detect kind */
278         for (i = 0; i < ARRAY_SIZE(ref_kind); i++) {
279                 prefix = ref_kind[i].prefix;
280                 if (strncmp(refname, prefix, ref_kind[i].pfxlen))
281                         continue;
282                 kind = ref_kind[i].kind;
283                 refname += ref_kind[i].pfxlen;
284                 break;
285         }
286         if (ARRAY_SIZE(ref_kind) <= i)
287                 return 0;
288
289         /* Don't add types the caller doesn't want */
290         if ((kind & ref_list->kinds) == 0)
291                 return 0;
292
293         commit = NULL;
294         if (ref_list->verbose || ref_list->with_commit || merge_filter != NO_FILTER) {
295                 commit = lookup_commit_reference_gently(sha1, 1);
296                 if (!commit)
297                         return error("branch '%s' does not point at a commit", refname);
298
299                 /* Filter with with_commit if specified */
300                 if (!is_descendant_of(commit, ref_list->with_commit))
301                         return 0;
302
303                 if (merge_filter != NO_FILTER)
304                         add_pending_object(&ref_list->revs,
305                                            (struct object *)commit, refname);
306         }
307
308         /* Resize buffer */
309         if (ref_list->index >= ref_list->alloc) {
310                 ref_list->alloc = alloc_nr(ref_list->alloc);
311                 ref_list->list = xrealloc(ref_list->list,
312                                 ref_list->alloc * sizeof(struct ref_item));
313         }
314
315         /* Record the new item */
316         newitem = &(ref_list->list[ref_list->index++]);
317         newitem->name = xstrdup(refname);
318         newitem->kind = kind;
319         newitem->commit = commit;
320         newitem->len = strlen(refname);
321         newitem->dest = resolve_symref(orig_refname, prefix);
322         /* adjust for "remotes/" */
323         if (newitem->kind == REF_REMOTE_BRANCH &&
324             ref_list->kinds != REF_REMOTE_BRANCH)
325                 newitem->len += 8;
326         if (newitem->len > ref_list->maxwidth)
327                 ref_list->maxwidth = newitem->len;
328
329         return 0;
330 }
331
332 static void free_ref_list(struct ref_list *ref_list)
333 {
334         int i;
335
336         for (i = 0; i < ref_list->index; i++) {
337                 free(ref_list->list[i].name);
338                 free(ref_list->list[i].dest);
339         }
340         free(ref_list->list);
341 }
342
343 static int ref_cmp(const void *r1, const void *r2)
344 {
345         struct ref_item *c1 = (struct ref_item *)(r1);
346         struct ref_item *c2 = (struct ref_item *)(r2);
347
348         if (c1->kind != c2->kind)
349                 return c1->kind - c2->kind;
350         return strcmp(c1->name, c2->name);
351 }
352
353 static void fill_tracking_info(struct strbuf *stat, const char *branch_name,
354                 int show_upstream_ref)
355 {
356         int ours, theirs;
357         struct branch *branch = branch_get(branch_name);
358
359         if (!stat_tracking_info(branch, &ours, &theirs)) {
360                 if (branch && branch->merge && branch->merge[0]->dst &&
361                     show_upstream_ref)
362                         strbuf_addf(stat, "[%s] ",
363                             shorten_unambiguous_ref(branch->merge[0]->dst, 0));
364                 return;
365         }
366
367         strbuf_addch(stat, '[');
368         if (show_upstream_ref)
369                 strbuf_addf(stat, "%s: ",
370                         shorten_unambiguous_ref(branch->merge[0]->dst, 0));
371         if (!ours)
372                 strbuf_addf(stat, "behind %d] ", theirs);
373         else if (!theirs)
374                 strbuf_addf(stat, "ahead %d] ", ours);
375         else
376                 strbuf_addf(stat, "ahead %d, behind %d] ", ours, theirs);
377 }
378
379 static int matches_merge_filter(struct commit *commit)
380 {
381         int is_merged;
382
383         if (merge_filter == NO_FILTER)
384                 return 1;
385
386         is_merged = !!(commit->object.flags & UNINTERESTING);
387         return (is_merged == (merge_filter == SHOW_MERGED));
388 }
389
390 static void print_ref_item(struct ref_item *item, int maxwidth, int verbose,
391                            int abbrev, int current, char *prefix)
392 {
393         char c;
394         int color;
395         struct commit *commit = item->commit;
396         struct strbuf out = STRBUF_INIT, name = STRBUF_INIT;
397
398         if (!matches_merge_filter(commit))
399                 return;
400
401         switch (item->kind) {
402         case REF_LOCAL_BRANCH:
403                 color = BRANCH_COLOR_LOCAL;
404                 break;
405         case REF_REMOTE_BRANCH:
406                 color = BRANCH_COLOR_REMOTE;
407                 break;
408         default:
409                 color = BRANCH_COLOR_PLAIN;
410                 break;
411         }
412
413         c = ' ';
414         if (current) {
415                 c = '*';
416                 color = BRANCH_COLOR_CURRENT;
417         }
418
419         strbuf_addf(&name, "%s%s", prefix, item->name);
420         if (verbose)
421                 strbuf_addf(&out, "%c %s%-*s%s", c, branch_get_color(color),
422                             maxwidth, name.buf,
423                             branch_get_color(BRANCH_COLOR_RESET));
424         else
425                 strbuf_addf(&out, "%c %s%s%s", c, branch_get_color(color),
426                             name.buf, branch_get_color(BRANCH_COLOR_RESET));
427
428         if (item->dest)
429                 strbuf_addf(&out, " -> %s", item->dest);
430         else if (verbose) {
431                 struct strbuf subject = STRBUF_INIT, stat = STRBUF_INIT;
432                 const char *sub = " **** invalid ref ****";
433
434                 commit = item->commit;
435                 if (commit && !parse_commit(commit)) {
436                         struct pretty_print_context ctx = {0};
437                         pretty_print_commit(CMIT_FMT_ONELINE, commit,
438                                             &subject, &ctx);
439                         sub = subject.buf;
440                 }
441
442                 if (item->kind == REF_LOCAL_BRANCH)
443                         fill_tracking_info(&stat, item->name, verbose > 1);
444
445                 strbuf_addf(&out, " %s %s%s",
446                         find_unique_abbrev(item->commit->object.sha1, abbrev),
447                         stat.buf, sub);
448                 strbuf_release(&stat);
449                 strbuf_release(&subject);
450         }
451         printf("%s\n", out.buf);
452         strbuf_release(&name);
453         strbuf_release(&out);
454 }
455
456 static int calc_maxwidth(struct ref_list *refs)
457 {
458         int i, w = 0;
459         for (i = 0; i < refs->index; i++) {
460                 if (!matches_merge_filter(refs->list[i].commit))
461                         continue;
462                 if (refs->list[i].len > w)
463                         w = refs->list[i].len;
464         }
465         return w;
466 }
467
468
469 static void show_detached(struct ref_list *ref_list)
470 {
471         struct commit *head_commit = lookup_commit_reference_gently(head_sha1, 1);
472
473         if (head_commit && is_descendant_of(head_commit, ref_list->with_commit)) {
474                 struct ref_item item;
475                 item.name = xstrdup("(no branch)");
476                 item.len = strlen(item.name);
477                 item.kind = REF_LOCAL_BRANCH;
478                 item.dest = NULL;
479                 item.commit = head_commit;
480                 if (item.len > ref_list->maxwidth)
481                         ref_list->maxwidth = item.len;
482                 print_ref_item(&item, ref_list->maxwidth, ref_list->verbose, ref_list->abbrev, 1, "");
483                 free(item.name);
484         }
485 }
486
487 static void print_ref_list(int kinds, int detached, int verbose, int abbrev, struct commit_list *with_commit)
488 {
489         int i;
490         struct ref_list ref_list;
491
492         memset(&ref_list, 0, sizeof(ref_list));
493         ref_list.kinds = kinds;
494         ref_list.verbose = verbose;
495         ref_list.abbrev = abbrev;
496         ref_list.with_commit = with_commit;
497         if (merge_filter != NO_FILTER)
498                 init_revisions(&ref_list.revs, NULL);
499         for_each_rawref(append_ref, &ref_list);
500         if (merge_filter != NO_FILTER) {
501                 struct commit *filter;
502                 filter = lookup_commit_reference_gently(merge_filter_ref, 0);
503                 filter->object.flags |= UNINTERESTING;
504                 add_pending_object(&ref_list.revs,
505                                    (struct object *) filter, "");
506                 ref_list.revs.limited = 1;
507                 prepare_revision_walk(&ref_list.revs);
508                 if (verbose)
509                         ref_list.maxwidth = calc_maxwidth(&ref_list);
510         }
511
512         qsort(ref_list.list, ref_list.index, sizeof(struct ref_item), ref_cmp);
513
514         detached = (detached && (kinds & REF_LOCAL_BRANCH));
515         if (detached)
516                 show_detached(&ref_list);
517
518         for (i = 0; i < ref_list.index; i++) {
519                 int current = !detached &&
520                         (ref_list.list[i].kind == REF_LOCAL_BRANCH) &&
521                         !strcmp(ref_list.list[i].name, head);
522                 char *prefix = (kinds != REF_REMOTE_BRANCH &&
523                                 ref_list.list[i].kind == REF_REMOTE_BRANCH)
524                                 ? "remotes/" : "";
525                 print_ref_item(&ref_list.list[i], ref_list.maxwidth, verbose,
526                                abbrev, current, prefix);
527         }
528
529         free_ref_list(&ref_list);
530 }
531
532 static void rename_branch(const char *oldname, const char *newname, int force)
533 {
534         struct strbuf oldref = STRBUF_INIT, newref = STRBUF_INIT, logmsg = STRBUF_INIT;
535         unsigned char sha1[20];
536         struct strbuf oldsection = STRBUF_INIT, newsection = STRBUF_INIT;
537         int recovery = 0;
538
539         if (!oldname)
540                 die("cannot rename the current branch while not on any.");
541
542         if (strbuf_check_branch_ref(&oldref, oldname)) {
543                 /*
544                  * Bad name --- this could be an attempt to rename a
545                  * ref that we used to allow to be created by accident.
546                  */
547                 if (resolve_ref(oldref.buf, sha1, 1, NULL))
548                         recovery = 1;
549                 else
550                         die("Invalid branch name: '%s'", oldname);
551         }
552
553         if (strbuf_check_branch_ref(&newref, newname))
554                 die("Invalid branch name: '%s'", newname);
555
556         if (resolve_ref(newref.buf, sha1, 1, NULL) && !force)
557                 die("A branch named '%s' already exists.", newref.buf + 11);
558
559         strbuf_addf(&logmsg, "Branch: renamed %s to %s",
560                  oldref.buf, newref.buf);
561
562         if (rename_ref(oldref.buf, newref.buf, logmsg.buf))
563                 die("Branch rename failed");
564         strbuf_release(&logmsg);
565
566         if (recovery)
567                 warning("Renamed a misnamed branch '%s' away", oldref.buf + 11);
568
569         /* no need to pass logmsg here as HEAD didn't really move */
570         if (!strcmp(oldname, head) && create_symref("HEAD", newref.buf, NULL))
571                 die("Branch renamed to %s, but HEAD is not updated!", newname);
572
573         strbuf_addf(&oldsection, "branch.%s", oldref.buf + 11);
574         strbuf_release(&oldref);
575         strbuf_addf(&newsection, "branch.%s", newref.buf + 11);
576         strbuf_release(&newref);
577         if (git_config_rename_section(oldsection.buf, newsection.buf) < 0)
578                 die("Branch is renamed, but update of config-file failed");
579         strbuf_release(&oldsection);
580         strbuf_release(&newsection);
581 }
582
583 static int opt_parse_merge_filter(const struct option *opt, const char *arg, int unset)
584 {
585         merge_filter = ((opt->long_name[0] == 'n')
586                         ? SHOW_NOT_MERGED
587                         : SHOW_MERGED);
588         if (unset)
589                 merge_filter = SHOW_NOT_MERGED; /* b/c for --no-merged */
590         if (!arg)
591                 arg = "HEAD";
592         if (get_sha1(arg, merge_filter_ref))
593                 die("malformed object name %s", arg);
594         return 0;
595 }
596
597 int cmd_branch(int argc, const char **argv, const char *prefix)
598 {
599         int delete = 0, rename = 0, force_create = 0;
600         int verbose = 0, abbrev = DEFAULT_ABBREV, detached = 0;
601         int reflog = 0;
602         enum branch_track track;
603         int kinds = REF_LOCAL_BRANCH;
604         struct commit_list *with_commit = NULL;
605
606         struct option options[] = {
607                 OPT_GROUP("Generic options"),
608                 OPT__VERBOSE(&verbose),
609                 OPT_SET_INT('t', "track",  &track, "set up tracking mode (see git-pull(1))",
610                         BRANCH_TRACK_EXPLICIT),
611                 OPT_SET_INT( 0, "set-upstream",  &track, "change upstream info",
612                         BRANCH_TRACK_OVERRIDE),
613                 OPT_BOOLEAN( 0 , "color",  &branch_use_color, "use colored output"),
614                 OPT_SET_INT('r', NULL,     &kinds, "act on remote-tracking branches",
615                         REF_REMOTE_BRANCH),
616                 {
617                         OPTION_CALLBACK, 0, "contains", &with_commit, "commit",
618                         "print only branches that contain the commit",
619                         PARSE_OPT_LASTARG_DEFAULT,
620                         parse_opt_with_commit, (intptr_t)"HEAD",
621                 },
622                 {
623                         OPTION_CALLBACK, 0, "with", &with_commit, "commit",
624                         "print only branches that contain the commit",
625                         PARSE_OPT_HIDDEN | PARSE_OPT_LASTARG_DEFAULT,
626                         parse_opt_with_commit, (intptr_t) "HEAD",
627                 },
628                 OPT__ABBREV(&abbrev),
629
630                 OPT_GROUP("Specific git-branch actions:"),
631                 OPT_SET_INT('a', NULL, &kinds, "list both remote-tracking and local branches",
632                         REF_REMOTE_BRANCH | REF_LOCAL_BRANCH),
633                 OPT_BIT('d', NULL, &delete, "delete fully merged branch", 1),
634                 OPT_BIT('D', NULL, &delete, "delete branch (even if not merged)", 2),
635                 OPT_BIT('m', NULL, &rename, "move/rename a branch and its reflog", 1),
636                 OPT_BIT('M', NULL, &rename, "move/rename a branch, even if target exists", 2),
637                 OPT_BOOLEAN('l', NULL, &reflog, "create the branch's reflog"),
638                 OPT_BOOLEAN('f', "force", &force_create, "force creation (when already exists)"),
639                 {
640                         OPTION_CALLBACK, 0, "no-merged", &merge_filter_ref,
641                         "commit", "print only not merged branches",
642                         PARSE_OPT_LASTARG_DEFAULT | PARSE_OPT_NONEG,
643                         opt_parse_merge_filter, (intptr_t) "HEAD",
644                 },
645                 {
646                         OPTION_CALLBACK, 0, "merged", &merge_filter_ref,
647                         "commit", "print only merged branches",
648                         PARSE_OPT_LASTARG_DEFAULT | PARSE_OPT_NONEG,
649                         opt_parse_merge_filter, (intptr_t) "HEAD",
650                 },
651                 OPT_END(),
652         };
653
654         git_config(git_branch_config, NULL);
655
656         if (branch_use_color == -1)
657                 branch_use_color = git_use_color_default;
658
659         track = git_branch_track;
660
661         head = resolve_ref("HEAD", head_sha1, 0, NULL);
662         if (!head)
663                 die("Failed to resolve HEAD as a valid ref.");
664         head = xstrdup(head);
665         if (!strcmp(head, "HEAD")) {
666                 detached = 1;
667         } else {
668                 if (prefixcmp(head, "refs/heads/"))
669                         die("HEAD not found below refs/heads!");
670                 head += 11;
671         }
672         hashcpy(merge_filter_ref, head_sha1);
673
674         argc = parse_options(argc, argv, prefix, options, builtin_branch_usage,
675                              0);
676         if (!!delete + !!rename + !!force_create > 1)
677                 usage_with_options(builtin_branch_usage, options);
678
679         if (delete)
680                 return delete_branches(argc, argv, delete > 1, kinds);
681         else if (argc == 0)
682                 print_ref_list(kinds, detached, verbose, abbrev, with_commit);
683         else if (rename && (argc == 1))
684                 rename_branch(head, argv[0], rename > 1);
685         else if (rename && (argc == 2))
686                 rename_branch(argv[0], argv[1], rename > 1);
687         else if (argc <= 2) {
688                 if (kinds != REF_LOCAL_BRANCH)
689                         die("-a and -r options to 'git branch' do not make sense with a branch name");
690                 create_branch(head, argv[0], (argc == 2) ? argv[1] : head,
691                               force_create, reflog, track);
692         } else
693                 usage_with_options(builtin_branch_usage, options);
694
695         return 0;
696 }