Merge branch 'master' of git://git.kernel.org/pub/scm/git/git
[git/jnareb-git.git] / builtin / checkout.c
blobf8033f446e8f9ef1807aa28c2f9eca4e821c42c9
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"
24 static const char * const checkout_usage[] = {
25 N_("git checkout [options] <branch>"),
26 N_("git checkout [options] [<branch>] -- <file>..."),
27 NULL,
30 struct checkout_opts {
31 int patch_mode;
32 int quiet;
33 int merge;
34 int force;
35 int force_detach;
36 int writeout_stage;
37 int overwrite_ignore;
39 const char *new_branch;
40 const char *new_branch_force;
41 const char *new_orphan_branch;
42 int new_branch_log;
43 enum branch_track track;
44 struct diff_options diff_options;
46 int branch_exists;
47 const char *prefix;
48 const char **pathspec;
49 struct tree *source_tree;
52 static int post_checkout_hook(struct commit *old, struct commit *new,
53 int changed)
55 return run_hook(NULL, "post-checkout",
56 sha1_to_hex(old ? old->object.sha1 : null_sha1),
57 sha1_to_hex(new ? new->object.sha1 : null_sha1),
58 changed ? "1" : "0", NULL);
59 /* "new" can be NULL when checking out from the index before
60 a commit exists. */
64 static int update_some(const unsigned char *sha1, const char *base, int baselen,
65 const char *pathname, unsigned mode, int stage, void *context)
67 int len;
68 struct cache_entry *ce;
70 if (S_ISDIR(mode))
71 return READ_TREE_RECURSIVE;
73 len = baselen + strlen(pathname);
74 ce = xcalloc(1, cache_entry_size(len));
75 hashcpy(ce->sha1, sha1);
76 memcpy(ce->name, base, baselen);
77 memcpy(ce->name + baselen, pathname, len - baselen);
78 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
79 ce->ce_namelen = len;
80 ce->ce_mode = create_ce_mode(mode);
81 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
82 return 0;
85 static int read_tree_some(struct tree *tree, const char **pathspec)
87 struct pathspec ps;
88 init_pathspec(&ps, pathspec);
89 read_tree_recursive(tree, "", 0, 0, &ps, update_some, NULL);
90 free_pathspec(&ps);
92 /* update the index with the given tree's info
93 * for all args, expanding wildcards, and exit
94 * with any non-zero return code.
96 return 0;
99 static int skip_same_name(struct cache_entry *ce, int pos)
101 while (++pos < active_nr &&
102 !strcmp(active_cache[pos]->name, ce->name))
103 ; /* skip */
104 return pos;
107 static int check_stage(int stage, struct cache_entry *ce, int pos)
109 while (pos < active_nr &&
110 !strcmp(active_cache[pos]->name, ce->name)) {
111 if (ce_stage(active_cache[pos]) == stage)
112 return 0;
113 pos++;
115 if (stage == 2)
116 return error(_("path '%s' does not have our version"), ce->name);
117 else
118 return error(_("path '%s' does not have their version"), ce->name);
121 static int check_stages(unsigned stages, struct cache_entry *ce, int pos)
123 unsigned seen = 0;
124 const char *name = ce->name;
126 while (pos < active_nr) {
127 ce = active_cache[pos];
128 if (strcmp(name, ce->name))
129 break;
130 seen |= (1 << ce_stage(ce));
131 pos++;
133 if ((stages & seen) != stages)
134 return error(_("path '%s' does not have all necessary versions"),
135 name);
136 return 0;
139 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
140 struct checkout *state)
142 while (pos < active_nr &&
143 !strcmp(active_cache[pos]->name, ce->name)) {
144 if (ce_stage(active_cache[pos]) == stage)
145 return checkout_entry(active_cache[pos], state, NULL);
146 pos++;
148 if (stage == 2)
149 return error(_("path '%s' does not have our version"), ce->name);
150 else
151 return error(_("path '%s' does not have their version"), ce->name);
154 static int checkout_merged(int pos, struct checkout *state)
156 struct cache_entry *ce = active_cache[pos];
157 const char *path = ce->name;
158 mmfile_t ancestor, ours, theirs;
159 int status;
160 unsigned char sha1[20];
161 mmbuffer_t result_buf;
162 unsigned char threeway[3][20];
163 unsigned mode = 0;
165 memset(threeway, 0, sizeof(threeway));
166 while (pos < active_nr) {
167 int stage;
168 stage = ce_stage(ce);
169 if (!stage || strcmp(path, ce->name))
170 break;
171 hashcpy(threeway[stage - 1], ce->sha1);
172 if (stage == 2)
173 mode = create_ce_mode(ce->ce_mode);
174 pos++;
175 ce = active_cache[pos];
177 if (is_null_sha1(threeway[1]) || is_null_sha1(threeway[2]))
178 return error(_("path '%s' does not have necessary versions"), path);
180 read_mmblob(&ancestor, threeway[0]);
181 read_mmblob(&ours, threeway[1]);
182 read_mmblob(&theirs, threeway[2]);
185 * NEEDSWORK: re-create conflicts from merges with
186 * merge.renormalize set, too
188 status = ll_merge(&result_buf, path, &ancestor, "base",
189 &ours, "ours", &theirs, "theirs", NULL);
190 free(ancestor.ptr);
191 free(ours.ptr);
192 free(theirs.ptr);
193 if (status < 0 || !result_buf.ptr) {
194 free(result_buf.ptr);
195 return error(_("path '%s': cannot merge"), path);
199 * NEEDSWORK:
200 * There is absolutely no reason to write this as a blob object
201 * and create a phony cache entry just to leak. This hack is
202 * primarily to get to the write_entry() machinery that massages
203 * the contents to work-tree format and writes out which only
204 * allows it for a cache entry. The code in write_entry() needs
205 * to be refactored to allow us to feed a <buffer, size, mode>
206 * instead of a cache entry. Such a refactoring would help
207 * merge_recursive as well (it also writes the merge result to the
208 * object database even when it may contain conflicts).
210 if (write_sha1_file(result_buf.ptr, result_buf.size,
211 blob_type, sha1))
212 die(_("Unable to add merge result for '%s'"), path);
213 ce = make_cache_entry(mode, sha1, path, 2, 0);
214 if (!ce)
215 die(_("make_cache_entry failed for path '%s'"), path);
216 status = checkout_entry(ce, state, NULL);
217 return status;
220 static int checkout_paths(const struct checkout_opts *opts,
221 const char *revision)
223 int pos;
224 struct checkout state;
225 static char *ps_matched;
226 unsigned char rev[20];
227 int flag;
228 struct commit *head;
229 int errs = 0;
230 int stage = opts->writeout_stage;
231 int merge = opts->merge;
232 int newfd;
233 struct lock_file *lock_file;
235 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
236 die(_("'%s' cannot be used with updating paths"), "--track");
238 if (opts->new_branch_log)
239 die(_("'%s' cannot be used with updating paths"), "-l");
241 if (opts->force && opts->patch_mode)
242 die(_("'%s' cannot be used with updating paths"), "-f");
244 if (opts->force_detach)
245 die(_("'%s' cannot be used with updating paths"), "--detach");
247 if (opts->merge && opts->patch_mode)
248 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
250 if (opts->force && opts->merge)
251 die(_("'%s' cannot be used with %s"), "-f", "-m");
253 if (opts->new_branch)
254 die(_("Cannot update paths and switch to branch '%s' at the same time."),
255 opts->new_branch);
257 if (opts->patch_mode)
258 return run_add_interactive(revision, "--patch=checkout",
259 opts->pathspec);
261 lock_file = xcalloc(1, sizeof(struct lock_file));
263 newfd = hold_locked_index(lock_file, 1);
264 if (read_cache_preload(opts->pathspec) < 0)
265 return error(_("corrupt index file"));
267 if (opts->source_tree)
268 read_tree_some(opts->source_tree, opts->pathspec);
270 for (pos = 0; opts->pathspec[pos]; pos++)
272 ps_matched = xcalloc(1, pos);
275 * Make sure all pathspecs participated in locating the paths
276 * to be checked out.
278 for (pos = 0; pos < active_nr; pos++) {
279 struct cache_entry *ce = active_cache[pos];
280 ce->ce_flags &= ~CE_MATCHED;
281 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
283 * "git checkout tree-ish -- path", but this entry
284 * is in the original index; it will not be checked
285 * out to the working tree and it does not matter
286 * if pathspec matched this entry. We will not do
287 * anything to this entry at all.
289 continue;
291 * Either this entry came from the tree-ish we are
292 * checking the paths out of, or we are checking out
293 * of the index.
295 * If it comes from the tree-ish, we already know it
296 * matches the pathspec and could just stamp
297 * CE_MATCHED to it from update_some(). But we still
298 * need ps_matched and read_tree_recursive (and
299 * eventually tree_entry_interesting) cannot fill
300 * ps_matched yet. Once it can, we can avoid calling
301 * match_pathspec() for _all_ entries when
302 * opts->source_tree != NULL.
304 if (match_pathspec(opts->pathspec, ce->name, ce_namelen(ce),
305 0, ps_matched))
306 ce->ce_flags |= CE_MATCHED;
309 if (report_path_error(ps_matched, opts->pathspec, opts->prefix)) {
310 free(ps_matched);
311 return 1;
313 free(ps_matched);
315 /* "checkout -m path" to recreate conflicted state */
316 if (opts->merge)
317 unmerge_marked_index(&the_index);
319 /* Any unmerged paths? */
320 for (pos = 0; pos < active_nr; pos++) {
321 struct cache_entry *ce = active_cache[pos];
322 if (ce->ce_flags & CE_MATCHED) {
323 if (!ce_stage(ce))
324 continue;
325 if (opts->force) {
326 warning(_("path '%s' is unmerged"), ce->name);
327 } else if (stage) {
328 errs |= check_stage(stage, ce, pos);
329 } else if (opts->merge) {
330 errs |= check_stages((1<<2) | (1<<3), ce, pos);
331 } else {
332 errs = 1;
333 error(_("path '%s' is unmerged"), ce->name);
335 pos = skip_same_name(ce, pos) - 1;
338 if (errs)
339 return 1;
341 /* Now we are committed to check them out */
342 memset(&state, 0, sizeof(state));
343 state.force = 1;
344 state.refresh_cache = 1;
345 for (pos = 0; pos < active_nr; pos++) {
346 struct cache_entry *ce = active_cache[pos];
347 if (ce->ce_flags & CE_MATCHED) {
348 if (!ce_stage(ce)) {
349 errs |= checkout_entry(ce, &state, NULL);
350 continue;
352 if (stage)
353 errs |= checkout_stage(stage, ce, pos, &state);
354 else if (merge)
355 errs |= checkout_merged(pos, &state);
356 pos = skip_same_name(ce, pos) - 1;
360 if (write_cache(newfd, active_cache, active_nr) ||
361 commit_locked_index(lock_file))
362 die(_("unable to write new index file"));
364 read_ref_full("HEAD", rev, 0, &flag);
365 head = lookup_commit_reference_gently(rev, 1);
367 errs |= post_checkout_hook(head, head, 0);
368 return errs;
371 static void show_local_changes(struct object *head,
372 const struct diff_options *opts)
374 struct rev_info rev;
375 /* I think we want full paths, even if we're in a subdirectory. */
376 init_revisions(&rev, NULL);
377 rev.diffopt.flags = opts->flags;
378 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
379 diff_setup_done(&rev.diffopt);
380 add_pending_object(&rev, head, NULL);
381 run_diff_index(&rev, 0);
384 static void describe_detached_head(const char *msg, struct commit *commit)
386 struct strbuf sb = STRBUF_INIT;
387 parse_commit(commit);
388 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
389 fprintf(stderr, "%s %s... %s\n", msg,
390 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
391 strbuf_release(&sb);
394 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
395 int worktree, int *writeout_error)
397 struct unpack_trees_options opts;
398 struct tree_desc tree_desc;
400 memset(&opts, 0, sizeof(opts));
401 opts.head_idx = -1;
402 opts.update = worktree;
403 opts.skip_unmerged = !worktree;
404 opts.reset = 1;
405 opts.merge = 1;
406 opts.fn = oneway_merge;
407 opts.verbose_update = !o->quiet && isatty(2);
408 opts.src_index = &the_index;
409 opts.dst_index = &the_index;
410 parse_tree(tree);
411 init_tree_desc(&tree_desc, tree->buffer, tree->size);
412 switch (unpack_trees(1, &tree_desc, &opts)) {
413 case -2:
414 *writeout_error = 1;
416 * We return 0 nevertheless, as the index is all right
417 * and more importantly we have made best efforts to
418 * update paths in the work tree, and we cannot revert
419 * them.
421 case 0:
422 return 0;
423 default:
424 return 128;
428 struct branch_info {
429 const char *name; /* The short name used */
430 const char *path; /* The full name of a real branch */
431 struct commit *commit; /* The named commit */
434 static void setup_branch_path(struct branch_info *branch)
436 struct strbuf buf = STRBUF_INIT;
438 strbuf_branchname(&buf, branch->name);
439 if (strcmp(buf.buf, branch->name))
440 branch->name = xstrdup(buf.buf);
441 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
442 branch->path = strbuf_detach(&buf, NULL);
445 static int merge_working_tree(const struct checkout_opts *opts,
446 struct branch_info *old,
447 struct branch_info *new,
448 int *writeout_error)
450 int ret;
451 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
452 int newfd = hold_locked_index(lock_file, 1);
454 if (read_cache_preload(NULL) < 0)
455 return error(_("corrupt index file"));
457 resolve_undo_clear();
458 if (opts->force) {
459 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
460 if (ret)
461 return ret;
462 } else {
463 struct tree_desc trees[2];
464 struct tree *tree;
465 struct unpack_trees_options topts;
467 memset(&topts, 0, sizeof(topts));
468 topts.head_idx = -1;
469 topts.src_index = &the_index;
470 topts.dst_index = &the_index;
472 setup_unpack_trees_porcelain(&topts, "checkout");
474 refresh_cache(REFRESH_QUIET);
476 if (unmerged_cache()) {
477 error(_("you need to resolve your current index first"));
478 return 1;
481 /* 2-way merge to the new branch */
482 topts.initial_checkout = is_cache_unborn();
483 topts.update = 1;
484 topts.merge = 1;
485 topts.gently = opts->merge && old->commit;
486 topts.verbose_update = !opts->quiet && isatty(2);
487 topts.fn = twoway_merge;
488 if (opts->overwrite_ignore) {
489 topts.dir = xcalloc(1, sizeof(*topts.dir));
490 topts.dir->flags |= DIR_SHOW_IGNORED;
491 setup_standard_excludes(topts.dir);
493 tree = parse_tree_indirect(old->commit ?
494 old->commit->object.sha1 :
495 EMPTY_TREE_SHA1_BIN);
496 init_tree_desc(&trees[0], tree->buffer, tree->size);
497 tree = parse_tree_indirect(new->commit->object.sha1);
498 init_tree_desc(&trees[1], tree->buffer, tree->size);
500 ret = unpack_trees(2, trees, &topts);
501 if (ret == -1) {
503 * Unpack couldn't do a trivial merge; either
504 * give up or do a real merge, depending on
505 * whether the merge flag was used.
507 struct tree *result;
508 struct tree *work;
509 struct merge_options o;
510 if (!opts->merge)
511 return 1;
514 * Without old->commit, the below is the same as
515 * the two-tree unpack we already tried and failed.
517 if (!old->commit)
518 return 1;
520 /* Do more real merge */
523 * We update the index fully, then write the
524 * tree from the index, then merge the new
525 * branch with the current tree, with the old
526 * branch as the base. Then we reset the index
527 * (but not the working tree) to the new
528 * branch, leaving the working tree as the
529 * merged version, but skipping unmerged
530 * entries in the index.
533 add_files_to_cache(NULL, NULL, 0);
535 * NEEDSWORK: carrying over local changes
536 * when branches have different end-of-line
537 * normalization (or clean+smudge rules) is
538 * a pain; plumb in an option to set
539 * o.renormalize?
541 init_merge_options(&o);
542 o.verbosity = 0;
543 work = write_tree_from_memory(&o);
545 ret = reset_tree(new->commit->tree, opts, 1,
546 writeout_error);
547 if (ret)
548 return ret;
549 o.ancestor = old->name;
550 o.branch1 = new->name;
551 o.branch2 = "local";
552 merge_trees(&o, new->commit->tree, work,
553 old->commit->tree, &result);
554 ret = reset_tree(new->commit->tree, opts, 0,
555 writeout_error);
556 if (ret)
557 return ret;
561 if (write_cache(newfd, active_cache, active_nr) ||
562 commit_locked_index(lock_file))
563 die(_("unable to write new index file"));
565 if (!opts->force && !opts->quiet)
566 show_local_changes(&new->commit->object, &opts->diff_options);
568 return 0;
571 static void report_tracking(struct branch_info *new)
573 struct strbuf sb = STRBUF_INIT;
574 struct branch *branch = branch_get(new->name);
576 if (!format_tracking_info(branch, &sb))
577 return;
578 fputs(sb.buf, stdout);
579 strbuf_release(&sb);
582 static void update_refs_for_switch(const struct checkout_opts *opts,
583 struct branch_info *old,
584 struct branch_info *new)
586 struct strbuf msg = STRBUF_INIT;
587 const char *old_desc;
588 if (opts->new_branch) {
589 if (opts->new_orphan_branch) {
590 if (opts->new_branch_log && !log_all_ref_updates) {
591 int temp;
592 char log_file[PATH_MAX];
593 char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
595 temp = log_all_ref_updates;
596 log_all_ref_updates = 1;
597 if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
598 fprintf(stderr, _("Can not do reflog for '%s'\n"),
599 opts->new_orphan_branch);
600 log_all_ref_updates = temp;
601 return;
603 log_all_ref_updates = temp;
606 else
607 create_branch(old->name, opts->new_branch, new->name,
608 opts->new_branch_force ? 1 : 0,
609 opts->new_branch_log,
610 opts->new_branch_force ? 1 : 0,
611 opts->quiet,
612 opts->track);
613 new->name = opts->new_branch;
614 setup_branch_path(new);
617 old_desc = old->name;
618 if (!old_desc && old->commit)
619 old_desc = sha1_to_hex(old->commit->object.sha1);
620 strbuf_addf(&msg, "checkout: moving from %s to %s",
621 old_desc ? old_desc : "(invalid)", new->name);
623 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
624 /* Nothing to do. */
625 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
626 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
627 REF_NODEREF, DIE_ON_ERR);
628 if (!opts->quiet) {
629 if (old->path && advice_detached_head)
630 detach_advice(new->name);
631 describe_detached_head(_("HEAD is now at"), new->commit);
633 } else if (new->path) { /* Switch branches. */
634 create_symref("HEAD", new->path, msg.buf);
635 if (!opts->quiet) {
636 if (old->path && !strcmp(new->path, old->path)) {
637 if (opts->new_branch_force)
638 fprintf(stderr, _("Reset branch '%s'\n"),
639 new->name);
640 else
641 fprintf(stderr, _("Already on '%s'\n"),
642 new->name);
643 } else if (opts->new_branch) {
644 if (opts->branch_exists)
645 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
646 else
647 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
648 } else {
649 fprintf(stderr, _("Switched to branch '%s'\n"),
650 new->name);
653 if (old->path && old->name) {
654 char log_file[PATH_MAX], ref_file[PATH_MAX];
656 git_snpath(log_file, sizeof(log_file), "logs/%s", old->path);
657 git_snpath(ref_file, sizeof(ref_file), "%s", old->path);
658 if (!file_exists(ref_file) && file_exists(log_file))
659 remove_path(log_file);
662 remove_branch_state();
663 strbuf_release(&msg);
664 if (!opts->quiet &&
665 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
666 report_tracking(new);
669 static int add_pending_uninteresting_ref(const char *refname,
670 const unsigned char *sha1,
671 int flags, void *cb_data)
673 add_pending_sha1(cb_data, refname, sha1, UNINTERESTING);
674 return 0;
677 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
679 parse_commit(commit);
680 strbuf_addstr(sb, " ");
681 strbuf_addstr(sb,
682 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
683 strbuf_addch(sb, ' ');
684 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
685 strbuf_addch(sb, '\n');
688 #define ORPHAN_CUTOFF 4
689 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
691 struct commit *c, *last = NULL;
692 struct strbuf sb = STRBUF_INIT;
693 int lost = 0;
694 while ((c = get_revision(revs)) != NULL) {
695 if (lost < ORPHAN_CUTOFF)
696 describe_one_orphan(&sb, c);
697 last = c;
698 lost++;
700 if (ORPHAN_CUTOFF < lost) {
701 int more = lost - ORPHAN_CUTOFF;
702 if (more == 1)
703 describe_one_orphan(&sb, last);
704 else
705 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
708 fprintf(stderr,
710 /* The singular version */
711 "Warning: you are leaving %d commit behind, "
712 "not connected to\n"
713 "any of your branches:\n\n"
714 "%s\n",
715 /* The plural version */
716 "Warning: you are leaving %d commits behind, "
717 "not connected to\n"
718 "any of your branches:\n\n"
719 "%s\n",
720 /* Give ngettext() the count */
721 lost),
722 lost,
723 sb.buf);
724 strbuf_release(&sb);
726 if (advice_detached_head)
727 fprintf(stderr,
729 "If you want to keep them by creating a new branch, "
730 "this may be a good time\nto do so with:\n\n"
731 " git branch new_branch_name %s\n\n"),
732 sha1_to_hex(commit->object.sha1));
736 * We are about to leave commit that was at the tip of a detached
737 * HEAD. If it is not reachable from any ref, this is the last chance
738 * for the user to do so without resorting to reflog.
740 static void orphaned_commit_warning(struct commit *old, struct commit *new)
742 struct rev_info revs;
743 struct object *object = &old->object;
744 struct object_array refs;
746 init_revisions(&revs, NULL);
747 setup_revisions(0, NULL, &revs, NULL);
749 object->flags &= ~UNINTERESTING;
750 add_pending_object(&revs, object, sha1_to_hex(object->sha1));
752 for_each_ref(add_pending_uninteresting_ref, &revs);
753 add_pending_sha1(&revs, "HEAD", new->object.sha1, UNINTERESTING);
755 refs = revs.pending;
756 revs.leak_pending = 1;
758 if (prepare_revision_walk(&revs))
759 die(_("internal error in revision walk"));
760 if (!(old->object.flags & UNINTERESTING))
761 suggest_reattach(old, &revs);
762 else
763 describe_detached_head(_("Previous HEAD position was"), old);
765 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
766 free(refs.objects);
769 static int switch_branches(const struct checkout_opts *opts,
770 struct branch_info *new)
772 int ret = 0;
773 struct branch_info old;
774 void *path_to_free;
775 unsigned char rev[20];
776 int flag, writeout_error = 0;
777 memset(&old, 0, sizeof(old));
778 old.path = path_to_free = resolve_refdup("HEAD", rev, 0, &flag);
779 old.commit = lookup_commit_reference_gently(rev, 1);
780 if (!(flag & REF_ISSYMREF))
781 old.path = NULL;
783 if (old.path && !prefixcmp(old.path, "refs/heads/"))
784 old.name = old.path + strlen("refs/heads/");
786 if (!new->name) {
787 new->name = "HEAD";
788 new->commit = old.commit;
789 if (!new->commit)
790 die(_("You are on a branch yet to be born"));
791 parse_commit(new->commit);
794 ret = merge_working_tree(opts, &old, new, &writeout_error);
795 if (ret) {
796 free(path_to_free);
797 return ret;
800 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
801 orphaned_commit_warning(old.commit, new->commit);
803 update_refs_for_switch(opts, &old, new);
805 ret = post_checkout_hook(old.commit, new->commit, 1);
806 free(path_to_free);
807 return ret || writeout_error;
810 static int git_checkout_config(const char *var, const char *value, void *cb)
812 if (!strcmp(var, "diff.ignoresubmodules")) {
813 struct checkout_opts *opts = cb;
814 handle_ignore_submodules_arg(&opts->diff_options, value);
815 return 0;
818 if (!prefixcmp(var, "submodule."))
819 return parse_submodule_config_option(var, value);
821 return git_xmerge_config(var, value, NULL);
824 struct tracking_name_data {
825 const char *name;
826 char *remote;
827 int unique;
830 static int check_tracking_name(const char *refname, const unsigned char *sha1,
831 int flags, void *cb_data)
833 struct tracking_name_data *cb = cb_data;
834 const char *slash;
836 if (prefixcmp(refname, "refs/remotes/"))
837 return 0;
838 slash = strchr(refname + 13, '/');
839 if (!slash || strcmp(slash + 1, cb->name))
840 return 0;
841 if (cb->remote) {
842 cb->unique = 0;
843 return 0;
845 cb->remote = xstrdup(refname);
846 return 0;
849 static const char *unique_tracking_name(const char *name)
851 struct tracking_name_data cb_data = { NULL, NULL, 1 };
852 cb_data.name = name;
853 for_each_ref(check_tracking_name, &cb_data);
854 if (cb_data.unique)
855 return cb_data.remote;
856 free(cb_data.remote);
857 return NULL;
860 static int parse_branchname_arg(int argc, const char **argv,
861 int dwim_new_local_branch_ok,
862 struct branch_info *new,
863 struct tree **source_tree,
864 unsigned char rev[20],
865 const char **new_branch)
867 int argcount = 0;
868 unsigned char branch_rev[20];
869 const char *arg;
870 int has_dash_dash;
873 * case 1: git checkout <ref> -- [<paths>]
875 * <ref> must be a valid tree, everything after the '--' must be
876 * a path.
878 * case 2: git checkout -- [<paths>]
880 * everything after the '--' must be paths.
882 * case 3: git checkout <something> [<paths>]
884 * With no paths, if <something> is a commit, that is to
885 * switch to the branch or detach HEAD at it. As a special case,
886 * if <something> is A...B (missing A or B means HEAD but you can
887 * omit at most one side), and if there is a unique merge base
888 * between A and B, A...B names that merge base.
890 * With no paths, if <something> is _not_ a commit, no -t nor -b
891 * was given, and there is a tracking branch whose name is
892 * <something> in one and only one remote, then this is a short-hand
893 * to fork local <something> from that remote-tracking branch.
895 * Otherwise <something> shall not be ambiguous.
896 * - If it's *only* a reference, treat it like case (1).
897 * - If it's only a path, treat it like case (2).
898 * - else: fail.
901 if (!argc)
902 return 0;
904 if (!strcmp(argv[0], "--")) /* case (2) */
905 return 1;
907 arg = argv[0];
908 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
910 if (!strcmp(arg, "-"))
911 arg = "@{-1}";
913 if (get_sha1_mb(arg, rev)) {
914 if (has_dash_dash) /* case (1) */
915 die(_("invalid reference: %s"), arg);
916 if (dwim_new_local_branch_ok &&
917 !check_filename(NULL, arg) &&
918 argc == 1) {
919 const char *remote = unique_tracking_name(arg);
920 if (!remote || get_sha1(remote, rev))
921 return argcount;
922 *new_branch = arg;
923 arg = remote;
924 /* DWIMmed to create local branch */
925 } else {
926 return argcount;
930 /* we can't end up being in (2) anymore, eat the argument */
931 argcount++;
932 argv++;
933 argc--;
935 new->name = arg;
936 setup_branch_path(new);
938 if (!check_refname_format(new->path, 0) &&
939 !read_ref(new->path, branch_rev))
940 hashcpy(rev, branch_rev);
941 else
942 new->path = NULL; /* not an existing branch */
944 new->commit = lookup_commit_reference_gently(rev, 1);
945 if (!new->commit) {
946 /* not a commit */
947 *source_tree = parse_tree_indirect(rev);
948 } else {
949 parse_commit(new->commit);
950 *source_tree = new->commit->tree;
953 if (!*source_tree) /* case (1): want a tree */
954 die(_("reference is not a tree: %s"), arg);
955 if (!has_dash_dash) {/* case (3 -> 1) */
957 * Do not complain the most common case
958 * git checkout branch
959 * even if there happen to be a file called 'branch';
960 * it would be extremely annoying.
962 if (argc)
963 verify_non_filename(NULL, arg);
964 } else {
965 argcount++;
966 argv++;
967 argc--;
970 return argcount;
973 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
975 int status;
976 struct strbuf branch_ref = STRBUF_INIT;
978 if (!opts->new_branch)
979 die(_("You are on a branch yet to be born"));
980 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
981 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
982 strbuf_release(&branch_ref);
983 if (!opts->quiet)
984 fprintf(stderr, _("Switched to a new branch '%s'\n"),
985 opts->new_branch);
986 return status;
989 static int checkout_branch(struct checkout_opts *opts,
990 struct branch_info *new)
992 if (opts->pathspec)
993 die(_("paths cannot be used with switching branches"));
995 if (opts->patch_mode)
996 die(_("'%s' cannot be used with switching branches"),
997 "--patch");
999 if (opts->writeout_stage)
1000 die(_("'%s' cannot be used with switching branches"),
1001 "--ours/--theirs");
1003 if (opts->force && opts->merge)
1004 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1006 if (opts->force_detach && opts->new_branch)
1007 die(_("'%s' cannot be used with '%s'"),
1008 "--detach", "-b/-B/--orphan");
1010 if (opts->new_orphan_branch) {
1011 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1012 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1013 } else if (opts->force_detach) {
1014 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1015 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1016 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1017 opts->track = git_branch_track;
1019 if (new->name && !new->commit)
1020 die(_("Cannot switch branch to a non-commit '%s'"),
1021 new->name);
1023 if (!new->commit && opts->new_branch) {
1024 unsigned char rev[20];
1025 int flag;
1027 if (!read_ref_full("HEAD", rev, 0, &flag) &&
1028 (flag & REF_ISSYMREF) && is_null_sha1(rev))
1029 return switch_unborn_to_new_branch(opts);
1031 return switch_branches(opts, new);
1034 int cmd_checkout(int argc, const char **argv, const char *prefix)
1036 struct checkout_opts opts;
1037 struct branch_info new;
1038 char *conflict_style = NULL;
1039 int dwim_new_local_branch = 1;
1040 struct option options[] = {
1041 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1042 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1043 N_("create and checkout a new branch")),
1044 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1045 N_("create/reset and checkout a branch")),
1046 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1047 OPT_BOOLEAN(0, "detach", &opts.force_detach, N_("detach the HEAD at named commit")),
1048 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1049 BRANCH_TRACK_EXPLICIT),
1050 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new branch"), N_("new unparented branch")),
1051 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1053 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1055 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1056 OPT_BOOLEAN('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1057 OPT_BOOLEAN(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1058 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1059 N_("conflict style (merge or diff3)")),
1060 OPT_BOOLEAN('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1061 { OPTION_BOOLEAN, 0, "guess", &dwim_new_local_branch, NULL,
1062 N_("second guess 'git checkout no-such-branch'"),
1063 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
1064 OPT_END(),
1067 memset(&opts, 0, sizeof(opts));
1068 memset(&new, 0, sizeof(new));
1069 opts.overwrite_ignore = 1;
1070 opts.prefix = prefix;
1072 gitmodules_config();
1073 git_config(git_checkout_config, &opts);
1075 opts.track = BRANCH_TRACK_UNSPECIFIED;
1077 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1078 PARSE_OPT_KEEP_DASHDASH);
1080 if (conflict_style) {
1081 opts.merge = 1; /* implied */
1082 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1085 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1086 die(_("-b, -B and --orphan are mutually exclusive"));
1089 * From here on, new_branch will contain the branch to be checked out,
1090 * and new_branch_force and new_orphan_branch will tell us which one of
1091 * -b/-B/--orphan is being used.
1093 if (opts.new_branch_force)
1094 opts.new_branch = opts.new_branch_force;
1096 if (opts.new_orphan_branch)
1097 opts.new_branch = opts.new_orphan_branch;
1099 /* --track without -b/-B/--orphan should DWIM */
1100 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1101 const char *argv0 = argv[0];
1102 if (!argc || !strcmp(argv0, "--"))
1103 die (_("--track needs a branch name"));
1104 if (!prefixcmp(argv0, "refs/"))
1105 argv0 += 5;
1106 if (!prefixcmp(argv0, "remotes/"))
1107 argv0 += 8;
1108 argv0 = strchr(argv0, '/');
1109 if (!argv0 || !argv0[1])
1110 die (_("Missing branch name; try -b"));
1111 opts.new_branch = argv0 + 1;
1115 * Extract branch name from command line arguments, so
1116 * all that is left is pathspecs.
1118 * Handle
1120 * 1) git checkout <tree> -- [<paths>]
1121 * 2) git checkout -- [<paths>]
1122 * 3) git checkout <something> [<paths>]
1124 * including "last branch" syntax and DWIM-ery for names of
1125 * remote branches, erroring out for invalid or ambiguous cases.
1127 if (argc) {
1128 unsigned char rev[20];
1129 int dwim_ok =
1130 !opts.patch_mode &&
1131 dwim_new_local_branch &&
1132 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1133 !opts.new_branch;
1134 int n = parse_branchname_arg(argc, argv, dwim_ok,
1135 &new, &opts.source_tree,
1136 rev, &opts.new_branch);
1137 argv += n;
1138 argc -= n;
1141 if (argc) {
1142 opts.pathspec = get_pathspec(prefix, argv);
1144 if (!opts.pathspec)
1145 die(_("invalid path specification"));
1148 * Try to give more helpful suggestion.
1149 * new_branch && argc > 1 will be caught later.
1151 if (opts.new_branch && argc == 1)
1152 die(_("Cannot update paths and switch to branch '%s' at the same time.\n"
1153 "Did you intend to checkout '%s' which can not be resolved as commit?"),
1154 opts.new_branch, argv[0]);
1156 if (opts.force_detach)
1157 die(_("git checkout: --detach does not take a path argument '%s'"),
1158 argv[0]);
1160 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1161 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1162 "checking out of the index."));
1165 if (opts.new_branch) {
1166 struct strbuf buf = STRBUF_INIT;
1168 opts.branch_exists =
1169 validate_new_branchname(opts.new_branch, &buf,
1170 !!opts.new_branch_force,
1171 !!opts.new_branch_force);
1173 strbuf_release(&buf);
1176 if (opts.patch_mode || opts.pathspec)
1177 return checkout_paths(&opts, new.name);
1178 else
1179 return checkout_branch(&opts, &new);