add 'git credential' plumbing command
[git/git.git] / builtin / checkout.c
1 #include "cache.h"
2 #include "builtin.h"
3 #include "parse-options.h"
4 #include "refs.h"
5 #include "commit.h"
6 #include "tree.h"
7 #include "tree-walk.h"
8 #include "cache-tree.h"
9 #include "unpack-trees.h"
10 #include "dir.h"
11 #include "run-command.h"
12 #include "merge-recursive.h"
13 #include "branch.h"
14 #include "diff.h"
15 #include "revision.h"
16 #include "remote.h"
17 #include "blob.h"
18 #include "xdiff-interface.h"
19 #include "ll-merge.h"
20 #include "resolve-undo.h"
21 #include "submodule.h"
22 #include "argv-array.h"
23
24 static const char * const checkout_usage[] = {
25 "git checkout [options] <branch>",
26 "git checkout [options] [<branch>] -- <file>...",
27 NULL,
28 };
29
30 struct checkout_opts {
31 int quiet;
32 int merge;
33 int force;
34 int force_detach;
35 int writeout_stage;
36 int writeout_error;
37 int overwrite_ignore;
38
39 /* not set by parse_options */
40 int branch_exists;
41
42 const char *new_branch;
43 const char *new_branch_force;
44 const char *new_orphan_branch;
45 int new_branch_log;
46 enum branch_track track;
47 struct diff_options diff_options;
48 };
49
50 static int post_checkout_hook(struct commit *old, struct commit *new,
51 int changed)
52 {
53 return run_hook(NULL, "post-checkout",
54 sha1_to_hex(old ? old->object.sha1 : null_sha1),
55 sha1_to_hex(new ? new->object.sha1 : null_sha1),
56 changed ? "1" : "0", NULL);
57 /* "new" can be NULL when checking out from the index before
58 a commit exists. */
59
60 }
61
62 static int update_some(const unsigned char *sha1, const char *base, int baselen,
63 const char *pathname, unsigned mode, int stage, void *context)
64 {
65 int len;
66 struct cache_entry *ce;
67
68 if (S_ISDIR(mode))
69 return READ_TREE_RECURSIVE;
70
71 len = baselen + strlen(pathname);
72 ce = xcalloc(1, cache_entry_size(len));
73 hashcpy(ce->sha1, sha1);
74 memcpy(ce->name, base, baselen);
75 memcpy(ce->name + baselen, pathname, len - baselen);
76 ce->ce_flags = create_ce_flags(len, 0) | CE_UPDATE;
77 ce->ce_mode = create_ce_mode(mode);
78 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
79 return 0;
80 }
81
82 static int read_tree_some(struct tree *tree, const char **pathspec)
83 {
84 struct pathspec ps;
85 init_pathspec(&ps, pathspec);
86 read_tree_recursive(tree, "", 0, 0, &ps, update_some, NULL);
87 free_pathspec(&ps);
88
89 /* update the index with the given tree's info
90 * for all args, expanding wildcards, and exit
91 * with any non-zero return code.
92 */
93 return 0;
94 }
95
96 static int skip_same_name(struct cache_entry *ce, int pos)
97 {
98 while (++pos < active_nr &&
99 !strcmp(active_cache[pos]->name, ce->name))
100 ; /* skip */
101 return pos;
102 }
103
104 static int check_stage(int stage, struct cache_entry *ce, int pos)
105 {
106 while (pos < active_nr &&
107 !strcmp(active_cache[pos]->name, ce->name)) {
108 if (ce_stage(active_cache[pos]) == stage)
109 return 0;
110 pos++;
111 }
112 if (stage == 2)
113 return error(_("path '%s' does not have our version"), ce->name);
114 else
115 return error(_("path '%s' does not have their version"), ce->name);
116 }
117
118 static int check_stages(unsigned stages, struct cache_entry *ce, int pos)
119 {
120 unsigned seen = 0;
121 const char *name = ce->name;
122
123 while (pos < active_nr) {
124 ce = active_cache[pos];
125 if (strcmp(name, ce->name))
126 break;
127 seen |= (1 << ce_stage(ce));
128 pos++;
129 }
130 if ((stages & seen) != stages)
131 return error(_("path '%s' does not have all necessary versions"),
132 name);
133 return 0;
134 }
135
136 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
137 struct checkout *state)
138 {
139 while (pos < active_nr &&
140 !strcmp(active_cache[pos]->name, ce->name)) {
141 if (ce_stage(active_cache[pos]) == stage)
142 return checkout_entry(active_cache[pos], state, NULL);
143 pos++;
144 }
145 if (stage == 2)
146 return error(_("path '%s' does not have our version"), ce->name);
147 else
148 return error(_("path '%s' does not have their version"), ce->name);
149 }
150
151 static int checkout_merged(int pos, struct checkout *state)
152 {
153 struct cache_entry *ce = active_cache[pos];
154 const char *path = ce->name;
155 mmfile_t ancestor, ours, theirs;
156 int status;
157 unsigned char sha1[20];
158 mmbuffer_t result_buf;
159 unsigned char threeway[3][20];
160 unsigned mode = 0;
161
162 memset(threeway, 0, sizeof(threeway));
163 while (pos < active_nr) {
164 int stage;
165 stage = ce_stage(ce);
166 if (!stage || strcmp(path, ce->name))
167 break;
168 hashcpy(threeway[stage - 1], ce->sha1);
169 if (stage == 2)
170 mode = create_ce_mode(ce->ce_mode);
171 pos++;
172 ce = active_cache[pos];
173 }
174 if (is_null_sha1(threeway[1]) || is_null_sha1(threeway[2]))
175 return error(_("path '%s' does not have necessary versions"), path);
176
177 read_mmblob(&ancestor, threeway[0]);
178 read_mmblob(&ours, threeway[1]);
179 read_mmblob(&theirs, threeway[2]);
180
181 /*
182 * NEEDSWORK: re-create conflicts from merges with
183 * merge.renormalize set, too
184 */
185 status = ll_merge(&result_buf, path, &ancestor, "base",
186 &ours, "ours", &theirs, "theirs", NULL);
187 free(ancestor.ptr);
188 free(ours.ptr);
189 free(theirs.ptr);
190 if (status < 0 || !result_buf.ptr) {
191 free(result_buf.ptr);
192 return error(_("path '%s': cannot merge"), path);
193 }
194
195 /*
196 * NEEDSWORK:
197 * There is absolutely no reason to write this as a blob object
198 * and create a phony cache entry just to leak. This hack is
199 * primarily to get to the write_entry() machinery that massages
200 * the contents to work-tree format and writes out which only
201 * allows it for a cache entry. The code in write_entry() needs
202 * to be refactored to allow us to feed a <buffer, size, mode>
203 * instead of a cache entry. Such a refactoring would help
204 * merge_recursive as well (it also writes the merge result to the
205 * object database even when it may contain conflicts).
206 */
207 if (write_sha1_file(result_buf.ptr, result_buf.size,
208 blob_type, sha1))
209 die(_("Unable to add merge result for '%s'"), path);
210 ce = make_cache_entry(mode, sha1, path, 2, 0);
211 if (!ce)
212 die(_("make_cache_entry failed for path '%s'"), path);
213 status = checkout_entry(ce, state, NULL);
214 return status;
215 }
216
217 static int checkout_paths(struct tree *source_tree, const char **pathspec,
218 const char *prefix, struct checkout_opts *opts)
219 {
220 int pos;
221 struct checkout state;
222 static char *ps_matched;
223 unsigned char rev[20];
224 int flag;
225 struct commit *head;
226 int errs = 0;
227 int stage = opts->writeout_stage;
228 int merge = opts->merge;
229 int newfd;
230 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
231
232 newfd = hold_locked_index(lock_file, 1);
233 if (read_cache_preload(pathspec) < 0)
234 return error(_("corrupt index file"));
235
236 if (source_tree)
237 read_tree_some(source_tree, pathspec);
238
239 for (pos = 0; pathspec[pos]; pos++)
240 ;
241 ps_matched = xcalloc(1, pos);
242
243 for (pos = 0; pos < active_nr; pos++) {
244 struct cache_entry *ce = active_cache[pos];
245 if (source_tree && !(ce->ce_flags & CE_UPDATE))
246 continue;
247 match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, ps_matched);
248 }
249
250 if (report_path_error(ps_matched, pathspec, prefix))
251 return 1;
252
253 /* "checkout -m path" to recreate conflicted state */
254 if (opts->merge)
255 unmerge_cache(pathspec);
256
257 /* Any unmerged paths? */
258 for (pos = 0; pos < active_nr; pos++) {
259 struct cache_entry *ce = active_cache[pos];
260 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
261 if (!ce_stage(ce))
262 continue;
263 if (opts->force) {
264 warning(_("path '%s' is unmerged"), ce->name);
265 } else if (stage) {
266 errs |= check_stage(stage, ce, pos);
267 } else if (opts->merge) {
268 errs |= check_stages((1<<2) | (1<<3), ce, pos);
269 } else {
270 errs = 1;
271 error(_("path '%s' is unmerged"), ce->name);
272 }
273 pos = skip_same_name(ce, pos) - 1;
274 }
275 }
276 if (errs)
277 return 1;
278
279 /* Now we are committed to check them out */
280 memset(&state, 0, sizeof(state));
281 state.force = 1;
282 state.refresh_cache = 1;
283 for (pos = 0; pos < active_nr; pos++) {
284 struct cache_entry *ce = active_cache[pos];
285 if (source_tree && !(ce->ce_flags & CE_UPDATE))
286 continue;
287 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
288 if (!ce_stage(ce)) {
289 errs |= checkout_entry(ce, &state, NULL);
290 continue;
291 }
292 if (stage)
293 errs |= checkout_stage(stage, ce, pos, &state);
294 else if (merge)
295 errs |= checkout_merged(pos, &state);
296 pos = skip_same_name(ce, pos) - 1;
297 }
298 }
299
300 if (write_cache(newfd, active_cache, active_nr) ||
301 commit_locked_index(lock_file))
302 die(_("unable to write new index file"));
303
304 read_ref_full("HEAD", rev, 0, &flag);
305 head = lookup_commit_reference_gently(rev, 1);
306
307 errs |= post_checkout_hook(head, head, 0);
308 return errs;
309 }
310
311 static void show_local_changes(struct object *head, struct diff_options *opts)
312 {
313 struct rev_info rev;
314 /* I think we want full paths, even if we're in a subdirectory. */
315 init_revisions(&rev, NULL);
316 rev.diffopt.flags = opts->flags;
317 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
318 if (diff_setup_done(&rev.diffopt) < 0)
319 die(_("diff_setup_done failed"));
320 add_pending_object(&rev, head, NULL);
321 run_diff_index(&rev, 0);
322 }
323
324 static void describe_detached_head(const char *msg, struct commit *commit)
325 {
326 struct strbuf sb = STRBUF_INIT;
327 parse_commit(commit);
328 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
329 fprintf(stderr, "%s %s... %s\n", msg,
330 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
331 strbuf_release(&sb);
332 }
333
334 static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
335 {
336 struct unpack_trees_options opts;
337 struct tree_desc tree_desc;
338
339 memset(&opts, 0, sizeof(opts));
340 opts.head_idx = -1;
341 opts.update = worktree;
342 opts.skip_unmerged = !worktree;
343 opts.reset = 1;
344 opts.merge = 1;
345 opts.fn = oneway_merge;
346 opts.verbose_update = !o->quiet && isatty(2);
347 opts.src_index = &the_index;
348 opts.dst_index = &the_index;
349 parse_tree(tree);
350 init_tree_desc(&tree_desc, tree->buffer, tree->size);
351 switch (unpack_trees(1, &tree_desc, &opts)) {
352 case -2:
353 o->writeout_error = 1;
354 /*
355 * We return 0 nevertheless, as the index is all right
356 * and more importantly we have made best efforts to
357 * update paths in the work tree, and we cannot revert
358 * them.
359 */
360 case 0:
361 return 0;
362 default:
363 return 128;
364 }
365 }
366
367 struct branch_info {
368 const char *name; /* The short name used */
369 const char *path; /* The full name of a real branch */
370 struct commit *commit; /* The named commit */
371 };
372
373 static void setup_branch_path(struct branch_info *branch)
374 {
375 struct strbuf buf = STRBUF_INIT;
376
377 strbuf_branchname(&buf, branch->name);
378 if (strcmp(buf.buf, branch->name))
379 branch->name = xstrdup(buf.buf);
380 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
381 branch->path = strbuf_detach(&buf, NULL);
382 }
383
384 static int merge_working_tree(struct checkout_opts *opts,
385 struct branch_info *old, struct branch_info *new)
386 {
387 int ret;
388 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
389 int newfd = hold_locked_index(lock_file, 1);
390
391 if (read_cache_preload(NULL) < 0)
392 return error(_("corrupt index file"));
393
394 resolve_undo_clear();
395 if (opts->force) {
396 ret = reset_tree(new->commit->tree, opts, 1);
397 if (ret)
398 return ret;
399 } else {
400 struct tree_desc trees[2];
401 struct tree *tree;
402 struct unpack_trees_options topts;
403
404 memset(&topts, 0, sizeof(topts));
405 topts.head_idx = -1;
406 topts.src_index = &the_index;
407 topts.dst_index = &the_index;
408
409 setup_unpack_trees_porcelain(&topts, "checkout");
410
411 refresh_cache(REFRESH_QUIET);
412
413 if (unmerged_cache()) {
414 error(_("you need to resolve your current index first"));
415 return 1;
416 }
417
418 /* 2-way merge to the new branch */
419 topts.initial_checkout = is_cache_unborn();
420 topts.update = 1;
421 topts.merge = 1;
422 topts.gently = opts->merge && old->commit;
423 topts.verbose_update = !opts->quiet && isatty(2);
424 topts.fn = twoway_merge;
425 if (opts->overwrite_ignore) {
426 topts.dir = xcalloc(1, sizeof(*topts.dir));
427 topts.dir->flags |= DIR_SHOW_IGNORED;
428 setup_standard_excludes(topts.dir);
429 }
430 tree = parse_tree_indirect(old->commit ?
431 old->commit->object.sha1 :
432 EMPTY_TREE_SHA1_BIN);
433 init_tree_desc(&trees[0], tree->buffer, tree->size);
434 tree = parse_tree_indirect(new->commit->object.sha1);
435 init_tree_desc(&trees[1], tree->buffer, tree->size);
436
437 ret = unpack_trees(2, trees, &topts);
438 if (ret == -1) {
439 /*
440 * Unpack couldn't do a trivial merge; either
441 * give up or do a real merge, depending on
442 * whether the merge flag was used.
443 */
444 struct tree *result;
445 struct tree *work;
446 struct merge_options o;
447 if (!opts->merge)
448 return 1;
449
450 /*
451 * Without old->commit, the below is the same as
452 * the two-tree unpack we already tried and failed.
453 */
454 if (!old->commit)
455 return 1;
456
457 /* Do more real merge */
458
459 /*
460 * We update the index fully, then write the
461 * tree from the index, then merge the new
462 * branch with the current tree, with the old
463 * branch as the base. Then we reset the index
464 * (but not the working tree) to the new
465 * branch, leaving the working tree as the
466 * merged version, but skipping unmerged
467 * entries in the index.
468 */
469
470 add_files_to_cache(NULL, NULL, 0);
471 /*
472 * NEEDSWORK: carrying over local changes
473 * when branches have different end-of-line
474 * normalization (or clean+smudge rules) is
475 * a pain; plumb in an option to set
476 * o.renormalize?
477 */
478 init_merge_options(&o);
479 o.verbosity = 0;
480 work = write_tree_from_memory(&o);
481
482 ret = reset_tree(new->commit->tree, opts, 1);
483 if (ret)
484 return ret;
485 o.ancestor = old->name;
486 o.branch1 = new->name;
487 o.branch2 = "local";
488 merge_trees(&o, new->commit->tree, work,
489 old->commit->tree, &result);
490 ret = reset_tree(new->commit->tree, opts, 0);
491 if (ret)
492 return ret;
493 }
494 }
495
496 if (write_cache(newfd, active_cache, active_nr) ||
497 commit_locked_index(lock_file))
498 die(_("unable to write new index file"));
499
500 if (!opts->force && !opts->quiet)
501 show_local_changes(&new->commit->object, &opts->diff_options);
502
503 return 0;
504 }
505
506 static void report_tracking(struct branch_info *new)
507 {
508 struct strbuf sb = STRBUF_INIT;
509 struct branch *branch = branch_get(new->name);
510
511 if (!format_tracking_info(branch, &sb))
512 return;
513 fputs(sb.buf, stdout);
514 strbuf_release(&sb);
515 }
516
517 static void update_refs_for_switch(struct checkout_opts *opts,
518 struct branch_info *old,
519 struct branch_info *new)
520 {
521 struct strbuf msg = STRBUF_INIT;
522 const char *old_desc;
523 if (opts->new_branch) {
524 if (opts->new_orphan_branch) {
525 if (opts->new_branch_log && !log_all_ref_updates) {
526 int temp;
527 char log_file[PATH_MAX];
528 char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
529
530 temp = log_all_ref_updates;
531 log_all_ref_updates = 1;
532 if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
533 fprintf(stderr, _("Can not do reflog for '%s'\n"),
534 opts->new_orphan_branch);
535 log_all_ref_updates = temp;
536 return;
537 }
538 log_all_ref_updates = temp;
539 }
540 }
541 else
542 create_branch(old->name, opts->new_branch, new->name,
543 opts->new_branch_force ? 1 : 0,
544 opts->new_branch_log,
545 opts->new_branch_force ? 1 : 0,
546 opts->quiet,
547 opts->track);
548 new->name = opts->new_branch;
549 setup_branch_path(new);
550 }
551
552 old_desc = old->name;
553 if (!old_desc && old->commit)
554 old_desc = sha1_to_hex(old->commit->object.sha1);
555 strbuf_addf(&msg, "checkout: moving from %s to %s",
556 old_desc ? old_desc : "(invalid)", new->name);
557
558 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
559 /* Nothing to do. */
560 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
561 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
562 REF_NODEREF, DIE_ON_ERR);
563 if (!opts->quiet) {
564 if (old->path && advice_detached_head)
565 detach_advice(new->name);
566 describe_detached_head(_("HEAD is now at"), new->commit);
567 }
568 } else if (new->path) { /* Switch branches. */
569 create_symref("HEAD", new->path, msg.buf);
570 if (!opts->quiet) {
571 if (old->path && !strcmp(new->path, old->path)) {
572 if (opts->new_branch_force)
573 fprintf(stderr, _("Reset branch '%s'\n"),
574 new->name);
575 else
576 fprintf(stderr, _("Already on '%s'\n"),
577 new->name);
578 } else if (opts->new_branch) {
579 if (opts->branch_exists)
580 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
581 else
582 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
583 } else {
584 fprintf(stderr, _("Switched to branch '%s'\n"),
585 new->name);
586 }
587 }
588 if (old->path && old->name) {
589 char log_file[PATH_MAX], ref_file[PATH_MAX];
590
591 git_snpath(log_file, sizeof(log_file), "logs/%s", old->path);
592 git_snpath(ref_file, sizeof(ref_file), "%s", old->path);
593 if (!file_exists(ref_file) && file_exists(log_file))
594 remove_path(log_file);
595 }
596 }
597 remove_branch_state();
598 strbuf_release(&msg);
599 if (!opts->quiet &&
600 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
601 report_tracking(new);
602 }
603
604 static int add_pending_uninteresting_ref(const char *refname,
605 const unsigned char *sha1,
606 int flags, void *cb_data)
607 {
608 add_pending_sha1(cb_data, refname, sha1, flags | UNINTERESTING);
609 return 0;
610 }
611
612 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
613 {
614 parse_commit(commit);
615 strbuf_addstr(sb, " ");
616 strbuf_addstr(sb,
617 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
618 strbuf_addch(sb, ' ');
619 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
620 strbuf_addch(sb, '\n');
621 }
622
623 #define ORPHAN_CUTOFF 4
624 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
625 {
626 struct commit *c, *last = NULL;
627 struct strbuf sb = STRBUF_INIT;
628 int lost = 0;
629 while ((c = get_revision(revs)) != NULL) {
630 if (lost < ORPHAN_CUTOFF)
631 describe_one_orphan(&sb, c);
632 last = c;
633 lost++;
634 }
635 if (ORPHAN_CUTOFF < lost) {
636 int more = lost - ORPHAN_CUTOFF;
637 if (more == 1)
638 describe_one_orphan(&sb, last);
639 else
640 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
641 }
642
643 fprintf(stderr,
644 Q_(
645 /* The singular version */
646 "Warning: you are leaving %d commit behind, "
647 "not connected to\n"
648 "any of your branches:\n\n"
649 "%s\n",
650 /* The plural version */
651 "Warning: you are leaving %d commits behind, "
652 "not connected to\n"
653 "any of your branches:\n\n"
654 "%s\n",
655 /* Give ngettext() the count */
656 lost),
657 lost,
658 sb.buf);
659 strbuf_release(&sb);
660
661 if (advice_detached_head)
662 fprintf(stderr,
663 _(
664 "If you want to keep them by creating a new branch, "
665 "this may be a good time\nto do so with:\n\n"
666 " git branch new_branch_name %s\n\n"),
667 sha1_to_hex(commit->object.sha1));
668 }
669
670 /*
671 * We are about to leave commit that was at the tip of a detached
672 * HEAD. If it is not reachable from any ref, this is the last chance
673 * for the user to do so without resorting to reflog.
674 */
675 static void orphaned_commit_warning(struct commit *old, struct commit *new)
676 {
677 struct rev_info revs;
678 struct object *object = &old->object;
679 struct object_array refs;
680
681 init_revisions(&revs, NULL);
682 setup_revisions(0, NULL, &revs, NULL);
683
684 object->flags &= ~UNINTERESTING;
685 add_pending_object(&revs, object, sha1_to_hex(object->sha1));
686
687 for_each_ref(add_pending_uninteresting_ref, &revs);
688 add_pending_sha1(&revs, "HEAD", new->object.sha1, UNINTERESTING);
689
690 refs = revs.pending;
691 revs.leak_pending = 1;
692
693 if (prepare_revision_walk(&revs))
694 die(_("internal error in revision walk"));
695 if (!(old->object.flags & UNINTERESTING))
696 suggest_reattach(old, &revs);
697 else
698 describe_detached_head(_("Previous HEAD position was"), old);
699
700 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
701 free(refs.objects);
702 }
703
704 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
705 {
706 int ret = 0;
707 struct branch_info old;
708 void *path_to_free;
709 unsigned char rev[20];
710 int flag;
711 memset(&old, 0, sizeof(old));
712 old.path = path_to_free = resolve_refdup("HEAD", rev, 0, &flag);
713 old.commit = lookup_commit_reference_gently(rev, 1);
714 if (!(flag & REF_ISSYMREF))
715 old.path = NULL;
716
717 if (old.path && !prefixcmp(old.path, "refs/heads/"))
718 old.name = old.path + strlen("refs/heads/");
719
720 if (!new->name) {
721 new->name = "HEAD";
722 new->commit = old.commit;
723 if (!new->commit)
724 die(_("You are on a branch yet to be born"));
725 parse_commit(new->commit);
726 }
727
728 ret = merge_working_tree(opts, &old, new);
729 if (ret) {
730 free(path_to_free);
731 return ret;
732 }
733
734 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
735 orphaned_commit_warning(old.commit, new->commit);
736
737 update_refs_for_switch(opts, &old, new);
738
739 ret = post_checkout_hook(old.commit, new->commit, 1);
740 free(path_to_free);
741 return ret || opts->writeout_error;
742 }
743
744 static int git_checkout_config(const char *var, const char *value, void *cb)
745 {
746 if (!strcmp(var, "diff.ignoresubmodules")) {
747 struct checkout_opts *opts = cb;
748 handle_ignore_submodules_arg(&opts->diff_options, value);
749 return 0;
750 }
751
752 if (!prefixcmp(var, "submodule."))
753 return parse_submodule_config_option(var, value);
754
755 return git_xmerge_config(var, value, NULL);
756 }
757
758 static int interactive_checkout(const char *revision, const char **pathspec,
759 struct checkout_opts *opts)
760 {
761 return run_add_interactive(revision, "--patch=checkout", pathspec);
762 }
763
764 struct tracking_name_data {
765 const char *name;
766 char *remote;
767 int unique;
768 };
769
770 static int check_tracking_name(const char *refname, const unsigned char *sha1,
771 int flags, void *cb_data)
772 {
773 struct tracking_name_data *cb = cb_data;
774 const char *slash;
775
776 if (prefixcmp(refname, "refs/remotes/"))
777 return 0;
778 slash = strchr(refname + 13, '/');
779 if (!slash || strcmp(slash + 1, cb->name))
780 return 0;
781 if (cb->remote) {
782 cb->unique = 0;
783 return 0;
784 }
785 cb->remote = xstrdup(refname);
786 return 0;
787 }
788
789 static const char *unique_tracking_name(const char *name)
790 {
791 struct tracking_name_data cb_data = { NULL, NULL, 1 };
792 cb_data.name = name;
793 for_each_ref(check_tracking_name, &cb_data);
794 if (cb_data.unique)
795 return cb_data.remote;
796 free(cb_data.remote);
797 return NULL;
798 }
799
800 static int parse_branchname_arg(int argc, const char **argv,
801 int dwim_new_local_branch_ok,
802 struct branch_info *new,
803 struct tree **source_tree,
804 unsigned char rev[20],
805 const char **new_branch)
806 {
807 int argcount = 0;
808 unsigned char branch_rev[20];
809 const char *arg;
810 int has_dash_dash;
811
812 /*
813 * case 1: git checkout <ref> -- [<paths>]
814 *
815 * <ref> must be a valid tree, everything after the '--' must be
816 * a path.
817 *
818 * case 2: git checkout -- [<paths>]
819 *
820 * everything after the '--' must be paths.
821 *
822 * case 3: git checkout <something> [<paths>]
823 *
824 * With no paths, if <something> is a commit, that is to
825 * switch to the branch or detach HEAD at it. As a special case,
826 * if <something> is A...B (missing A or B means HEAD but you can
827 * omit at most one side), and if there is a unique merge base
828 * between A and B, A...B names that merge base.
829 *
830 * With no paths, if <something> is _not_ a commit, no -t nor -b
831 * was given, and there is a tracking branch whose name is
832 * <something> in one and only one remote, then this is a short-hand
833 * to fork local <something> from that remote-tracking branch.
834 *
835 * Otherwise <something> shall not be ambiguous.
836 * - If it's *only* a reference, treat it like case (1).
837 * - If it's only a path, treat it like case (2).
838 * - else: fail.
839 *
840 */
841 if (!argc)
842 return 0;
843
844 if (!strcmp(argv[0], "--")) /* case (2) */
845 return 1;
846
847 arg = argv[0];
848 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
849
850 if (!strcmp(arg, "-"))
851 arg = "@{-1}";
852
853 if (get_sha1_mb(arg, rev)) {
854 if (has_dash_dash) /* case (1) */
855 die(_("invalid reference: %s"), arg);
856 if (dwim_new_local_branch_ok &&
857 !check_filename(NULL, arg) &&
858 argc == 1) {
859 const char *remote = unique_tracking_name(arg);
860 if (!remote || get_sha1(remote, rev))
861 return argcount;
862 *new_branch = arg;
863 arg = remote;
864 /* DWIMmed to create local branch */
865 } else {
866 return argcount;
867 }
868 }
869
870 /* we can't end up being in (2) anymore, eat the argument */
871 argcount++;
872 argv++;
873 argc--;
874
875 new->name = arg;
876 setup_branch_path(new);
877
878 if (!check_refname_format(new->path, 0) &&
879 !read_ref(new->path, branch_rev))
880 hashcpy(rev, branch_rev);
881 else
882 new->path = NULL; /* not an existing branch */
883
884 new->commit = lookup_commit_reference_gently(rev, 1);
885 if (!new->commit) {
886 /* not a commit */
887 *source_tree = parse_tree_indirect(rev);
888 } else {
889 parse_commit(new->commit);
890 *source_tree = new->commit->tree;
891 }
892
893 if (!*source_tree) /* case (1): want a tree */
894 die(_("reference is not a tree: %s"), arg);
895 if (!has_dash_dash) {/* case (3 -> 1) */
896 /*
897 * Do not complain the most common case
898 * git checkout branch
899 * even if there happen to be a file called 'branch';
900 * it would be extremely annoying.
901 */
902 if (argc)
903 verify_non_filename(NULL, arg);
904 } else {
905 argcount++;
906 argv++;
907 argc--;
908 }
909
910 return argcount;
911 }
912
913 static int switch_unborn_to_new_branch(struct checkout_opts *opts)
914 {
915 int status;
916 struct strbuf branch_ref = STRBUF_INIT;
917
918 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
919 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
920 strbuf_release(&branch_ref);
921 return status;
922 }
923
924 int cmd_checkout(int argc, const char **argv, const char *prefix)
925 {
926 struct checkout_opts opts;
927 unsigned char rev[20];
928 struct branch_info new;
929 struct tree *source_tree = NULL;
930 char *conflict_style = NULL;
931 int patch_mode = 0;
932 int dwim_new_local_branch = 1;
933 struct option options[] = {
934 OPT__QUIET(&opts.quiet, "suppress progress reporting"),
935 OPT_STRING('b', NULL, &opts.new_branch, "branch",
936 "create and checkout a new branch"),
937 OPT_STRING('B', NULL, &opts.new_branch_force, "branch",
938 "create/reset and checkout a branch"),
939 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "create reflog for new branch"),
940 OPT_BOOLEAN(0, "detach", &opts.force_detach, "detach the HEAD at named commit"),
941 OPT_SET_INT('t', "track", &opts.track, "set upstream info for new branch",
942 BRANCH_TRACK_EXPLICIT),
943 OPT_STRING(0, "orphan", &opts.new_orphan_branch, "new branch", "new unparented branch"),
944 OPT_SET_INT('2', "ours", &opts.writeout_stage, "checkout our version for unmerged files",
945 2),
946 OPT_SET_INT('3', "theirs", &opts.writeout_stage, "checkout their version for unmerged files",
947 3),
948 OPT__FORCE(&opts.force, "force checkout (throw away local modifications)"),
949 OPT_BOOLEAN('m', "merge", &opts.merge, "perform a 3-way merge with the new branch"),
950 OPT_BOOLEAN(0, "overwrite-ignore", &opts.overwrite_ignore, "update ignored files (default)"),
951 OPT_STRING(0, "conflict", &conflict_style, "style",
952 "conflict style (merge or diff3)"),
953 OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
954 { OPTION_BOOLEAN, 0, "guess", &dwim_new_local_branch, NULL,
955 "second guess 'git checkout no-such-branch'",
956 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
957 OPT_END(),
958 };
959
960 memset(&opts, 0, sizeof(opts));
961 memset(&new, 0, sizeof(new));
962 opts.overwrite_ignore = 1;
963
964 gitmodules_config();
965 git_config(git_checkout_config, &opts);
966
967 opts.track = BRANCH_TRACK_UNSPECIFIED;
968
969 argc = parse_options(argc, argv, prefix, options, checkout_usage,
970 PARSE_OPT_KEEP_DASHDASH);
971
972 /* we can assume from now on new_branch = !new_branch_force */
973 if (opts.new_branch && opts.new_branch_force)
974 die(_("-B cannot be used with -b"));
975
976 /* copy -B over to -b, so that we can just check the latter */
977 if (opts.new_branch_force)
978 opts.new_branch = opts.new_branch_force;
979
980 if (patch_mode && (opts.track > 0 || opts.new_branch
981 || opts.new_branch_log || opts.merge || opts.force
982 || opts.force_detach))
983 die (_("--patch is incompatible with all other options"));
984
985 if (opts.force_detach && (opts.new_branch || opts.new_orphan_branch))
986 die(_("--detach cannot be used with -b/-B/--orphan"));
987 if (opts.force_detach && 0 < opts.track)
988 die(_("--detach cannot be used with -t"));
989
990 /* --track without -b should DWIM */
991 if (0 < opts.track && !opts.new_branch) {
992 const char *argv0 = argv[0];
993 if (!argc || !strcmp(argv0, "--"))
994 die (_("--track needs a branch name"));
995 if (!prefixcmp(argv0, "refs/"))
996 argv0 += 5;
997 if (!prefixcmp(argv0, "remotes/"))
998 argv0 += 8;
999 argv0 = strchr(argv0, '/');
1000 if (!argv0 || !argv0[1])
1001 die (_("Missing branch name; try -b"));
1002 opts.new_branch = argv0 + 1;
1003 }
1004
1005 if (opts.new_orphan_branch) {
1006 if (opts.new_branch)
1007 die(_("--orphan and -b|-B are mutually exclusive"));
1008 if (opts.track > 0)
1009 die(_("--orphan cannot be used with -t"));
1010 opts.new_branch = opts.new_orphan_branch;
1011 }
1012
1013 if (conflict_style) {
1014 opts.merge = 1; /* implied */
1015 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1016 }
1017
1018 if (opts.force && opts.merge)
1019 die(_("git checkout: -f and -m are incompatible"));
1020
1021 /*
1022 * Extract branch name from command line arguments, so
1023 * all that is left is pathspecs.
1024 *
1025 * Handle
1026 *
1027 * 1) git checkout <tree> -- [<paths>]
1028 * 2) git checkout -- [<paths>]
1029 * 3) git checkout <something> [<paths>]
1030 *
1031 * including "last branch" syntax and DWIM-ery for names of
1032 * remote branches, erroring out for invalid or ambiguous cases.
1033 */
1034 if (argc) {
1035 int dwim_ok =
1036 !patch_mode &&
1037 dwim_new_local_branch &&
1038 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1039 !opts.new_branch;
1040 int n = parse_branchname_arg(argc, argv, dwim_ok,
1041 &new, &source_tree, rev, &opts.new_branch);
1042 argv += n;
1043 argc -= n;
1044 }
1045
1046 if (opts.track == BRANCH_TRACK_UNSPECIFIED)
1047 opts.track = git_branch_track;
1048
1049 if (argc) {
1050 const char **pathspec = get_pathspec(prefix, argv);
1051
1052 if (!pathspec)
1053 die(_("invalid path specification"));
1054
1055 if (patch_mode)
1056 return interactive_checkout(new.name, pathspec, &opts);
1057
1058 /* Checkout paths */
1059 if (opts.new_branch) {
1060 if (argc == 1) {
1061 die(_("git checkout: updating paths is incompatible with switching branches.\nDid you intend to checkout '%s' which can not be resolved as commit?"), argv[0]);
1062 } else {
1063 die(_("git checkout: updating paths is incompatible with switching branches."));
1064 }
1065 }
1066
1067 if (opts.force_detach)
1068 die(_("git checkout: --detach does not take a path argument"));
1069
1070 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1071 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index."));
1072
1073 return checkout_paths(source_tree, pathspec, prefix, &opts);
1074 }
1075
1076 if (patch_mode)
1077 return interactive_checkout(new.name, NULL, &opts);
1078
1079 if (opts.new_branch) {
1080 struct strbuf buf = STRBUF_INIT;
1081
1082 opts.branch_exists = validate_new_branchname(opts.new_branch, &buf,
1083 !!opts.new_branch_force,
1084 !!opts.new_branch_force);
1085
1086 strbuf_release(&buf);
1087 }
1088
1089 if (new.name && !new.commit) {
1090 die(_("Cannot switch branch to a non-commit."));
1091 }
1092 if (opts.writeout_stage)
1093 die(_("--ours/--theirs is incompatible with switching branches."));
1094
1095 if (!new.commit && opts.new_branch) {
1096 unsigned char rev[20];
1097 int flag;
1098
1099 if (!read_ref_full("HEAD", rev, 0, &flag) &&
1100 (flag & REF_ISSYMREF) && is_null_sha1(rev))
1101 return switch_unborn_to_new_branch(&opts);
1102 }
1103 return switch_branches(&opts, &new);
1104 }