doc: prefer 'stash push' over 'stash save'
[git/git.git] / builtin / checkout.c
1 #include "builtin.h"
2 #include "config.h"
3 #include "lockfile.h"
4 #include "parse-options.h"
5 #include "refs.h"
6 #include "commit.h"
7 #include "tree.h"
8 #include "tree-walk.h"
9 #include "cache-tree.h"
10 #include "unpack-trees.h"
11 #include "dir.h"
12 #include "run-command.h"
13 #include "merge-recursive.h"
14 #include "branch.h"
15 #include "diff.h"
16 #include "revision.h"
17 #include "remote.h"
18 #include "blob.h"
19 #include "xdiff-interface.h"
20 #include "ll-merge.h"
21 #include "resolve-undo.h"
22 #include "submodule-config.h"
23 #include "submodule.h"
24
25 static const char * const checkout_usage[] = {
26 N_("git checkout [<options>] <branch>"),
27 N_("git checkout [<options>] [<branch>] -- <file>..."),
28 NULL,
29 };
30
31 struct checkout_opts {
32 int patch_mode;
33 int quiet;
34 int merge;
35 int force;
36 int force_detach;
37 int writeout_stage;
38 int overwrite_ignore;
39 int ignore_skipworktree;
40 int ignore_other_worktrees;
41 int show_progress;
42
43 const char *new_branch;
44 const char *new_branch_force;
45 const char *new_orphan_branch;
46 int new_branch_log;
47 enum branch_track track;
48 struct diff_options diff_options;
49
50 int branch_exists;
51 const char *prefix;
52 struct pathspec pathspec;
53 struct tree *source_tree;
54 };
55
56 static int post_checkout_hook(struct commit *old, struct commit *new,
57 int changed)
58 {
59 return run_hook_le(NULL, "post-checkout",
60 oid_to_hex(old ? &old->object.oid : &null_oid),
61 oid_to_hex(new ? &new->object.oid : &null_oid),
62 changed ? "1" : "0", NULL);
63 /* "new" can be NULL when checking out from the index before
64 a commit exists. */
65
66 }
67
68 static int update_some(const unsigned char *sha1, struct strbuf *base,
69 const char *pathname, unsigned mode, int stage, void *context)
70 {
71 int len;
72 struct cache_entry *ce;
73 int pos;
74
75 if (S_ISDIR(mode))
76 return READ_TREE_RECURSIVE;
77
78 len = base->len + strlen(pathname);
79 ce = xcalloc(1, cache_entry_size(len));
80 hashcpy(ce->oid.hash, sha1);
81 memcpy(ce->name, base->buf, base->len);
82 memcpy(ce->name + base->len, pathname, len - base->len);
83 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
84 ce->ce_namelen = len;
85 ce->ce_mode = create_ce_mode(mode);
86
87 /*
88 * If the entry is the same as the current index, we can leave the old
89 * entry in place. Whether it is UPTODATE or not, checkout_entry will
90 * do the right thing.
91 */
92 pos = cache_name_pos(ce->name, ce->ce_namelen);
93 if (pos >= 0) {
94 struct cache_entry *old = active_cache[pos];
95 if (ce->ce_mode == old->ce_mode &&
96 !oidcmp(&ce->oid, &old->oid)) {
97 old->ce_flags |= CE_UPDATE;
98 free(ce);
99 return 0;
100 }
101 }
102
103 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
104 return 0;
105 }
106
107 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
108 {
109 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
110
111 /* update the index with the given tree's info
112 * for all args, expanding wildcards, and exit
113 * with any non-zero return code.
114 */
115 return 0;
116 }
117
118 static int skip_same_name(const struct cache_entry *ce, int pos)
119 {
120 while (++pos < active_nr &&
121 !strcmp(active_cache[pos]->name, ce->name))
122 ; /* skip */
123 return pos;
124 }
125
126 static int check_stage(int stage, const struct cache_entry *ce, int pos)
127 {
128 while (pos < active_nr &&
129 !strcmp(active_cache[pos]->name, ce->name)) {
130 if (ce_stage(active_cache[pos]) == stage)
131 return 0;
132 pos++;
133 }
134 if (stage == 2)
135 return error(_("path '%s' does not have our version"), ce->name);
136 else
137 return error(_("path '%s' does not have their version"), ce->name);
138 }
139
140 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
141 {
142 unsigned seen = 0;
143 const char *name = ce->name;
144
145 while (pos < active_nr) {
146 ce = active_cache[pos];
147 if (strcmp(name, ce->name))
148 break;
149 seen |= (1 << ce_stage(ce));
150 pos++;
151 }
152 if ((stages & seen) != stages)
153 return error(_("path '%s' does not have all necessary versions"),
154 name);
155 return 0;
156 }
157
158 static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
159 const struct checkout *state)
160 {
161 while (pos < active_nr &&
162 !strcmp(active_cache[pos]->name, ce->name)) {
163 if (ce_stage(active_cache[pos]) == stage)
164 return checkout_entry(active_cache[pos], state, NULL);
165 pos++;
166 }
167 if (stage == 2)
168 return error(_("path '%s' does not have our version"), ce->name);
169 else
170 return error(_("path '%s' does not have their version"), ce->name);
171 }
172
173 static int checkout_merged(int pos, const struct checkout *state)
174 {
175 struct cache_entry *ce = active_cache[pos];
176 const char *path = ce->name;
177 mmfile_t ancestor, ours, theirs;
178 int status;
179 struct object_id oid;
180 mmbuffer_t result_buf;
181 struct object_id threeway[3];
182 unsigned mode = 0;
183
184 memset(threeway, 0, sizeof(threeway));
185 while (pos < active_nr) {
186 int stage;
187 stage = ce_stage(ce);
188 if (!stage || strcmp(path, ce->name))
189 break;
190 oidcpy(&threeway[stage - 1], &ce->oid);
191 if (stage == 2)
192 mode = create_ce_mode(ce->ce_mode);
193 pos++;
194 ce = active_cache[pos];
195 }
196 if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
197 return error(_("path '%s' does not have necessary versions"), path);
198
199 read_mmblob(&ancestor, &threeway[0]);
200 read_mmblob(&ours, &threeway[1]);
201 read_mmblob(&theirs, &threeway[2]);
202
203 /*
204 * NEEDSWORK: re-create conflicts from merges with
205 * merge.renormalize set, too
206 */
207 status = ll_merge(&result_buf, path, &ancestor, "base",
208 &ours, "ours", &theirs, "theirs", NULL);
209 free(ancestor.ptr);
210 free(ours.ptr);
211 free(theirs.ptr);
212 if (status < 0 || !result_buf.ptr) {
213 free(result_buf.ptr);
214 return error(_("path '%s': cannot merge"), path);
215 }
216
217 /*
218 * NEEDSWORK:
219 * There is absolutely no reason to write this as a blob object
220 * and create a phony cache entry. This hack is primarily to get
221 * to the write_entry() machinery that massages the contents to
222 * work-tree format and writes out which only allows it for a
223 * cache entry. The code in write_entry() needs to be refactored
224 * to allow us to feed a <buffer, size, mode> instead of a cache
225 * entry. Such a refactoring would help merge_recursive as well
226 * (it also writes the merge result to the object database even
227 * when it may contain conflicts).
228 */
229 if (write_sha1_file(result_buf.ptr, result_buf.size,
230 blob_type, oid.hash))
231 die(_("Unable to add merge result for '%s'"), path);
232 free(result_buf.ptr);
233 ce = make_cache_entry(mode, oid.hash, path, 2, 0);
234 if (!ce)
235 die(_("make_cache_entry failed for path '%s'"), path);
236 status = checkout_entry(ce, state, NULL);
237 free(ce);
238 return status;
239 }
240
241 static int checkout_paths(const struct checkout_opts *opts,
242 const char *revision)
243 {
244 int pos;
245 struct checkout state = CHECKOUT_INIT;
246 static char *ps_matched;
247 struct object_id rev;
248 struct commit *head;
249 int errs = 0;
250 struct lock_file *lock_file;
251
252 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
253 die(_("'%s' cannot be used with updating paths"), "--track");
254
255 if (opts->new_branch_log)
256 die(_("'%s' cannot be used with updating paths"), "-l");
257
258 if (opts->force && opts->patch_mode)
259 die(_("'%s' cannot be used with updating paths"), "-f");
260
261 if (opts->force_detach)
262 die(_("'%s' cannot be used with updating paths"), "--detach");
263
264 if (opts->merge && opts->patch_mode)
265 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
266
267 if (opts->force && opts->merge)
268 die(_("'%s' cannot be used with %s"), "-f", "-m");
269
270 if (opts->new_branch)
271 die(_("Cannot update paths and switch to branch '%s' at the same time."),
272 opts->new_branch);
273
274 if (opts->patch_mode)
275 return run_add_interactive(revision, "--patch=checkout",
276 &opts->pathspec);
277
278 lock_file = xcalloc(1, sizeof(struct lock_file));
279
280 hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
281 if (read_cache_preload(&opts->pathspec) < 0)
282 return error(_("index file corrupt"));
283
284 if (opts->source_tree)
285 read_tree_some(opts->source_tree, &opts->pathspec);
286
287 ps_matched = xcalloc(opts->pathspec.nr, 1);
288
289 /*
290 * Make sure all pathspecs participated in locating the paths
291 * to be checked out.
292 */
293 for (pos = 0; pos < active_nr; pos++) {
294 struct cache_entry *ce = active_cache[pos];
295 ce->ce_flags &= ~CE_MATCHED;
296 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
297 continue;
298 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
299 /*
300 * "git checkout tree-ish -- path", but this entry
301 * is in the original index; it will not be checked
302 * out to the working tree and it does not matter
303 * if pathspec matched this entry. We will not do
304 * anything to this entry at all.
305 */
306 continue;
307 /*
308 * Either this entry came from the tree-ish we are
309 * checking the paths out of, or we are checking out
310 * of the index.
311 *
312 * If it comes from the tree-ish, we already know it
313 * matches the pathspec and could just stamp
314 * CE_MATCHED to it from update_some(). But we still
315 * need ps_matched and read_tree_recursive (and
316 * eventually tree_entry_interesting) cannot fill
317 * ps_matched yet. Once it can, we can avoid calling
318 * match_pathspec() for _all_ entries when
319 * opts->source_tree != NULL.
320 */
321 if (ce_path_match(ce, &opts->pathspec, ps_matched))
322 ce->ce_flags |= CE_MATCHED;
323 }
324
325 if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
326 free(ps_matched);
327 return 1;
328 }
329 free(ps_matched);
330
331 /* "checkout -m path" to recreate conflicted state */
332 if (opts->merge)
333 unmerge_marked_index(&the_index);
334
335 /* Any unmerged paths? */
336 for (pos = 0; pos < active_nr; pos++) {
337 const struct cache_entry *ce = active_cache[pos];
338 if (ce->ce_flags & CE_MATCHED) {
339 if (!ce_stage(ce))
340 continue;
341 if (opts->force) {
342 warning(_("path '%s' is unmerged"), ce->name);
343 } else if (opts->writeout_stage) {
344 errs |= check_stage(opts->writeout_stage, ce, pos);
345 } else if (opts->merge) {
346 errs |= check_stages((1<<2) | (1<<3), ce, pos);
347 } else {
348 errs = 1;
349 error(_("path '%s' is unmerged"), ce->name);
350 }
351 pos = skip_same_name(ce, pos) - 1;
352 }
353 }
354 if (errs)
355 return 1;
356
357 /* Now we are committed to check them out */
358 state.force = 1;
359 state.refresh_cache = 1;
360 state.istate = &the_index;
361
362 enable_delayed_checkout(&state);
363 for (pos = 0; pos < active_nr; pos++) {
364 struct cache_entry *ce = active_cache[pos];
365 if (ce->ce_flags & CE_MATCHED) {
366 if (!ce_stage(ce)) {
367 errs |= checkout_entry(ce, &state, NULL);
368 continue;
369 }
370 if (opts->writeout_stage)
371 errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
372 else if (opts->merge)
373 errs |= checkout_merged(pos, &state);
374 pos = skip_same_name(ce, pos) - 1;
375 }
376 }
377 errs |= finish_delayed_checkout(&state);
378
379 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
380 die(_("unable to write new index file"));
381
382 read_ref_full("HEAD", 0, rev.hash, NULL);
383 head = lookup_commit_reference_gently(&rev, 1);
384
385 errs |= post_checkout_hook(head, head, 0);
386 return errs;
387 }
388
389 static void show_local_changes(struct object *head,
390 const struct diff_options *opts)
391 {
392 struct rev_info rev;
393 /* I think we want full paths, even if we're in a subdirectory. */
394 init_revisions(&rev, NULL);
395 rev.diffopt.flags = opts->flags;
396 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
397 diff_setup_done(&rev.diffopt);
398 add_pending_object(&rev, head, NULL);
399 run_diff_index(&rev, 0);
400 }
401
402 static void describe_detached_head(const char *msg, struct commit *commit)
403 {
404 struct strbuf sb = STRBUF_INIT;
405 if (!parse_commit(commit))
406 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
407 fprintf(stderr, "%s %s... %s\n", msg,
408 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV), sb.buf);
409 strbuf_release(&sb);
410 }
411
412 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
413 int worktree, int *writeout_error)
414 {
415 struct unpack_trees_options opts;
416 struct tree_desc tree_desc;
417
418 memset(&opts, 0, sizeof(opts));
419 opts.head_idx = -1;
420 opts.update = worktree;
421 opts.skip_unmerged = !worktree;
422 opts.reset = 1;
423 opts.merge = 1;
424 opts.fn = oneway_merge;
425 opts.verbose_update = o->show_progress;
426 opts.src_index = &the_index;
427 opts.dst_index = &the_index;
428 parse_tree(tree);
429 init_tree_desc(&tree_desc, tree->buffer, tree->size);
430 switch (unpack_trees(1, &tree_desc, &opts)) {
431 case -2:
432 *writeout_error = 1;
433 /*
434 * We return 0 nevertheless, as the index is all right
435 * and more importantly we have made best efforts to
436 * update paths in the work tree, and we cannot revert
437 * them.
438 */
439 /* fallthrough */
440 case 0:
441 return 0;
442 default:
443 return 128;
444 }
445 }
446
447 struct branch_info {
448 const char *name; /* The short name used */
449 const char *path; /* The full name of a real branch */
450 struct commit *commit; /* The named commit */
451 /*
452 * if not null the branch is detached because it's already
453 * checked out in this checkout
454 */
455 char *checkout;
456 };
457
458 static void setup_branch_path(struct branch_info *branch)
459 {
460 struct strbuf buf = STRBUF_INIT;
461
462 strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
463 if (strcmp(buf.buf, branch->name))
464 branch->name = xstrdup(buf.buf);
465 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
466 branch->path = strbuf_detach(&buf, NULL);
467 }
468
469 static int merge_working_tree(const struct checkout_opts *opts,
470 struct branch_info *old,
471 struct branch_info *new,
472 int *writeout_error)
473 {
474 int ret;
475 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
476
477 hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
478 if (read_cache_preload(NULL) < 0)
479 return error(_("index file corrupt"));
480
481 resolve_undo_clear();
482 if (opts->force) {
483 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
484 if (ret)
485 return ret;
486 } else {
487 struct tree_desc trees[2];
488 struct tree *tree;
489 struct unpack_trees_options topts;
490
491 memset(&topts, 0, sizeof(topts));
492 topts.head_idx = -1;
493 topts.src_index = &the_index;
494 topts.dst_index = &the_index;
495
496 setup_unpack_trees_porcelain(&topts, "checkout");
497
498 refresh_cache(REFRESH_QUIET);
499
500 if (unmerged_cache()) {
501 error(_("you need to resolve your current index first"));
502 return 1;
503 }
504
505 /* 2-way merge to the new branch */
506 topts.initial_checkout = is_cache_unborn();
507 topts.update = 1;
508 topts.merge = 1;
509 topts.gently = opts->merge && old->commit;
510 topts.verbose_update = opts->show_progress;
511 topts.fn = twoway_merge;
512 if (opts->overwrite_ignore) {
513 topts.dir = xcalloc(1, sizeof(*topts.dir));
514 topts.dir->flags |= DIR_SHOW_IGNORED;
515 setup_standard_excludes(topts.dir);
516 }
517 tree = parse_tree_indirect(old->commit ?
518 &old->commit->object.oid :
519 &empty_tree_oid);
520 init_tree_desc(&trees[0], tree->buffer, tree->size);
521 tree = parse_tree_indirect(&new->commit->object.oid);
522 init_tree_desc(&trees[1], tree->buffer, tree->size);
523
524 ret = unpack_trees(2, trees, &topts);
525 if (ret == -1) {
526 /*
527 * Unpack couldn't do a trivial merge; either
528 * give up or do a real merge, depending on
529 * whether the merge flag was used.
530 */
531 struct tree *result;
532 struct tree *work;
533 struct merge_options o;
534 if (!opts->merge)
535 return 1;
536
537 /*
538 * Without old->commit, the below is the same as
539 * the two-tree unpack we already tried and failed.
540 */
541 if (!old->commit)
542 return 1;
543
544 /* Do more real merge */
545
546 /*
547 * We update the index fully, then write the
548 * tree from the index, then merge the new
549 * branch with the current tree, with the old
550 * branch as the base. Then we reset the index
551 * (but not the working tree) to the new
552 * branch, leaving the working tree as the
553 * merged version, but skipping unmerged
554 * entries in the index.
555 */
556
557 add_files_to_cache(NULL, NULL, 0);
558 /*
559 * NEEDSWORK: carrying over local changes
560 * when branches have different end-of-line
561 * normalization (or clean+smudge rules) is
562 * a pain; plumb in an option to set
563 * o.renormalize?
564 */
565 init_merge_options(&o);
566 o.verbosity = 0;
567 work = write_tree_from_memory(&o);
568
569 ret = reset_tree(new->commit->tree, opts, 1,
570 writeout_error);
571 if (ret)
572 return ret;
573 o.ancestor = old->name;
574 o.branch1 = new->name;
575 o.branch2 = "local";
576 ret = merge_trees(&o, new->commit->tree, work,
577 old->commit->tree, &result);
578 if (ret < 0)
579 exit(128);
580 ret = reset_tree(new->commit->tree, opts, 0,
581 writeout_error);
582 strbuf_release(&o.obuf);
583 if (ret)
584 return ret;
585 }
586 }
587
588 if (!active_cache_tree)
589 active_cache_tree = cache_tree();
590
591 if (!cache_tree_fully_valid(active_cache_tree))
592 cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
593
594 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
595 die(_("unable to write new index file"));
596
597 if (!opts->force && !opts->quiet)
598 show_local_changes(&new->commit->object, &opts->diff_options);
599
600 return 0;
601 }
602
603 static void report_tracking(struct branch_info *new)
604 {
605 struct strbuf sb = STRBUF_INIT;
606 struct branch *branch = branch_get(new->name);
607
608 if (!format_tracking_info(branch, &sb))
609 return;
610 fputs(sb.buf, stdout);
611 strbuf_release(&sb);
612 }
613
614 static void update_refs_for_switch(const struct checkout_opts *opts,
615 struct branch_info *old,
616 struct branch_info *new)
617 {
618 struct strbuf msg = STRBUF_INIT;
619 const char *old_desc, *reflog_msg;
620 if (opts->new_branch) {
621 if (opts->new_orphan_branch) {
622 char *refname;
623
624 refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
625 if (opts->new_branch_log &&
626 !should_autocreate_reflog(refname)) {
627 int ret;
628 struct strbuf err = STRBUF_INIT;
629
630 ret = safe_create_reflog(refname, 1, &err);
631 if (ret) {
632 fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
633 opts->new_orphan_branch, err.buf);
634 strbuf_release(&err);
635 free(refname);
636 return;
637 }
638 strbuf_release(&err);
639 }
640 free(refname);
641 }
642 else
643 create_branch(opts->new_branch, new->name,
644 opts->new_branch_force ? 1 : 0,
645 opts->new_branch_log,
646 opts->new_branch_force ? 1 : 0,
647 opts->quiet,
648 opts->track);
649 new->name = opts->new_branch;
650 setup_branch_path(new);
651 }
652
653 old_desc = old->name;
654 if (!old_desc && old->commit)
655 old_desc = oid_to_hex(&old->commit->object.oid);
656
657 reflog_msg = getenv("GIT_REFLOG_ACTION");
658 if (!reflog_msg)
659 strbuf_addf(&msg, "checkout: moving from %s to %s",
660 old_desc ? old_desc : "(invalid)", new->name);
661 else
662 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
663
664 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
665 /* Nothing to do. */
666 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
667 update_ref(msg.buf, "HEAD", new->commit->object.oid.hash, NULL,
668 REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
669 if (!opts->quiet) {
670 if (old->path &&
671 advice_detached_head && !opts->force_detach)
672 detach_advice(new->name);
673 describe_detached_head(_("HEAD is now at"), new->commit);
674 }
675 } else if (new->path) { /* Switch branches. */
676 if (create_symref("HEAD", new->path, msg.buf) < 0)
677 die(_("unable to update HEAD"));
678 if (!opts->quiet) {
679 if (old->path && !strcmp(new->path, old->path)) {
680 if (opts->new_branch_force)
681 fprintf(stderr, _("Reset branch '%s'\n"),
682 new->name);
683 else
684 fprintf(stderr, _("Already on '%s'\n"),
685 new->name);
686 } else if (opts->new_branch) {
687 if (opts->branch_exists)
688 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
689 else
690 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
691 } else {
692 fprintf(stderr, _("Switched to branch '%s'\n"),
693 new->name);
694 }
695 }
696 if (old->path && old->name) {
697 if (!ref_exists(old->path) && reflog_exists(old->path))
698 delete_reflog(old->path);
699 }
700 }
701 remove_branch_state();
702 strbuf_release(&msg);
703 if (!opts->quiet &&
704 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
705 report_tracking(new);
706 }
707
708 static int add_pending_uninteresting_ref(const char *refname,
709 const struct object_id *oid,
710 int flags, void *cb_data)
711 {
712 add_pending_oid(cb_data, refname, oid, UNINTERESTING);
713 return 0;
714 }
715
716 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
717 {
718 strbuf_addstr(sb, " ");
719 strbuf_add_unique_abbrev(sb, commit->object.oid.hash, DEFAULT_ABBREV);
720 strbuf_addch(sb, ' ');
721 if (!parse_commit(commit))
722 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
723 strbuf_addch(sb, '\n');
724 }
725
726 #define ORPHAN_CUTOFF 4
727 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
728 {
729 struct commit *c, *last = NULL;
730 struct strbuf sb = STRBUF_INIT;
731 int lost = 0;
732 while ((c = get_revision(revs)) != NULL) {
733 if (lost < ORPHAN_CUTOFF)
734 describe_one_orphan(&sb, c);
735 last = c;
736 lost++;
737 }
738 if (ORPHAN_CUTOFF < lost) {
739 int more = lost - ORPHAN_CUTOFF;
740 if (more == 1)
741 describe_one_orphan(&sb, last);
742 else
743 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
744 }
745
746 fprintf(stderr,
747 Q_(
748 /* The singular version */
749 "Warning: you are leaving %d commit behind, "
750 "not connected to\n"
751 "any of your branches:\n\n"
752 "%s\n",
753 /* The plural version */
754 "Warning: you are leaving %d commits behind, "
755 "not connected to\n"
756 "any of your branches:\n\n"
757 "%s\n",
758 /* Give ngettext() the count */
759 lost),
760 lost,
761 sb.buf);
762 strbuf_release(&sb);
763
764 if (advice_detached_head)
765 fprintf(stderr,
766 Q_(
767 /* The singular version */
768 "If you want to keep it by creating a new branch, "
769 "this may be a good time\nto do so with:\n\n"
770 " git branch <new-branch-name> %s\n\n",
771 /* The plural version */
772 "If you want to keep them by creating a new branch, "
773 "this may be a good time\nto do so with:\n\n"
774 " git branch <new-branch-name> %s\n\n",
775 /* Give ngettext() the count */
776 lost),
777 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV));
778 }
779
780 /*
781 * We are about to leave commit that was at the tip of a detached
782 * HEAD. If it is not reachable from any ref, this is the last chance
783 * for the user to do so without resorting to reflog.
784 */
785 static void orphaned_commit_warning(struct commit *old, struct commit *new)
786 {
787 struct rev_info revs;
788 struct object *object = &old->object;
789 struct object_array refs;
790
791 init_revisions(&revs, NULL);
792 setup_revisions(0, NULL, &revs, NULL);
793
794 object->flags &= ~UNINTERESTING;
795 add_pending_object(&revs, object, oid_to_hex(&object->oid));
796
797 for_each_ref(add_pending_uninteresting_ref, &revs);
798 add_pending_oid(&revs, "HEAD", &new->object.oid, UNINTERESTING);
799
800 /* Save pending objects, so they can be cleaned up later. */
801 refs = revs.pending;
802 revs.leak_pending = 1;
803
804 /*
805 * prepare_revision_walk (together with .leak_pending = 1) makes us
806 * the sole owner of the list of pending objects.
807 */
808 if (prepare_revision_walk(&revs))
809 die(_("internal error in revision walk"));
810 if (!(old->object.flags & UNINTERESTING))
811 suggest_reattach(old, &revs);
812 else
813 describe_detached_head(_("Previous HEAD position was"), old);
814
815 /* Clean up objects used, as they will be reused. */
816 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
817
818 object_array_clear(&refs);
819 }
820
821 static int switch_branches(const struct checkout_opts *opts,
822 struct branch_info *new)
823 {
824 int ret = 0;
825 struct branch_info old;
826 void *path_to_free;
827 struct object_id rev;
828 int flag, writeout_error = 0;
829 memset(&old, 0, sizeof(old));
830 old.path = path_to_free = resolve_refdup("HEAD", 0, rev.hash, &flag);
831 if (old.path)
832 old.commit = lookup_commit_reference_gently(&rev, 1);
833 if (!(flag & REF_ISSYMREF))
834 old.path = NULL;
835
836 if (old.path)
837 skip_prefix(old.path, "refs/heads/", &old.name);
838
839 if (!new->name) {
840 new->name = "HEAD";
841 new->commit = old.commit;
842 if (!new->commit)
843 die(_("You are on a branch yet to be born"));
844 parse_commit_or_die(new->commit);
845 }
846
847 ret = merge_working_tree(opts, &old, new, &writeout_error);
848 if (ret) {
849 free(path_to_free);
850 return ret;
851 }
852
853 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
854 orphaned_commit_warning(old.commit, new->commit);
855
856 update_refs_for_switch(opts, &old, new);
857
858 ret = post_checkout_hook(old.commit, new->commit, 1);
859 free(path_to_free);
860 return ret || writeout_error;
861 }
862
863 static int git_checkout_config(const char *var, const char *value, void *cb)
864 {
865 if (!strcmp(var, "diff.ignoresubmodules")) {
866 struct checkout_opts *opts = cb;
867 handle_ignore_submodules_arg(&opts->diff_options, value);
868 return 0;
869 }
870
871 if (starts_with(var, "submodule."))
872 return git_default_submodule_config(var, value, NULL);
873
874 return git_xmerge_config(var, value, NULL);
875 }
876
877 struct tracking_name_data {
878 /* const */ char *src_ref;
879 char *dst_ref;
880 struct object_id *dst_oid;
881 int unique;
882 };
883
884 static int check_tracking_name(struct remote *remote, void *cb_data)
885 {
886 struct tracking_name_data *cb = cb_data;
887 struct refspec query;
888 memset(&query, 0, sizeof(struct refspec));
889 query.src = cb->src_ref;
890 if (remote_find_tracking(remote, &query) ||
891 get_oid(query.dst, cb->dst_oid)) {
892 free(query.dst);
893 return 0;
894 }
895 if (cb->dst_ref) {
896 free(query.dst);
897 cb->unique = 0;
898 return 0;
899 }
900 cb->dst_ref = query.dst;
901 return 0;
902 }
903
904 static const char *unique_tracking_name(const char *name, struct object_id *oid)
905 {
906 struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
907 cb_data.src_ref = xstrfmt("refs/heads/%s", name);
908 cb_data.dst_oid = oid;
909 for_each_remote(check_tracking_name, &cb_data);
910 free(cb_data.src_ref);
911 if (cb_data.unique)
912 return cb_data.dst_ref;
913 free(cb_data.dst_ref);
914 return NULL;
915 }
916
917 static int parse_branchname_arg(int argc, const char **argv,
918 int dwim_new_local_branch_ok,
919 struct branch_info *new,
920 struct checkout_opts *opts,
921 struct object_id *rev)
922 {
923 struct tree **source_tree = &opts->source_tree;
924 const char **new_branch = &opts->new_branch;
925 int argcount = 0;
926 struct object_id branch_rev;
927 const char *arg;
928 int dash_dash_pos;
929 int has_dash_dash = 0;
930 int i;
931
932 /*
933 * case 1: git checkout <ref> -- [<paths>]
934 *
935 * <ref> must be a valid tree, everything after the '--' must be
936 * a path.
937 *
938 * case 2: git checkout -- [<paths>]
939 *
940 * everything after the '--' must be paths.
941 *
942 * case 3: git checkout <something> [--]
943 *
944 * (a) If <something> is a commit, that is to
945 * switch to the branch or detach HEAD at it. As a special case,
946 * if <something> is A...B (missing A or B means HEAD but you can
947 * omit at most one side), and if there is a unique merge base
948 * between A and B, A...B names that merge base.
949 *
950 * (b) If <something> is _not_ a commit, either "--" is present
951 * or <something> is not a path, no -t or -b was given, and
952 * and there is a tracking branch whose name is <something>
953 * in one and only one remote, then this is a short-hand to
954 * fork local <something> from that remote-tracking branch.
955 *
956 * (c) Otherwise, if "--" is present, treat it like case (1).
957 *
958 * (d) Otherwise :
959 * - if it's a reference, treat it like case (1)
960 * - else if it's a path, treat it like case (2)
961 * - else: fail.
962 *
963 * case 4: git checkout <something> <paths>
964 *
965 * The first argument must not be ambiguous.
966 * - If it's *only* a reference, treat it like case (1).
967 * - If it's only a path, treat it like case (2).
968 * - else: fail.
969 *
970 */
971 if (!argc)
972 return 0;
973
974 arg = argv[0];
975 dash_dash_pos = -1;
976 for (i = 0; i < argc; i++) {
977 if (!strcmp(argv[i], "--")) {
978 dash_dash_pos = i;
979 break;
980 }
981 }
982 if (dash_dash_pos == 0)
983 return 1; /* case (2) */
984 else if (dash_dash_pos == 1)
985 has_dash_dash = 1; /* case (3) or (1) */
986 else if (dash_dash_pos >= 2)
987 die(_("only one reference expected, %d given."), dash_dash_pos);
988
989 if (!strcmp(arg, "-"))
990 arg = "@{-1}";
991
992 if (get_oid_mb(arg, rev)) {
993 /*
994 * Either case (3) or (4), with <something> not being
995 * a commit, or an attempt to use case (1) with an
996 * invalid ref.
997 *
998 * It's likely an error, but we need to find out if
999 * we should auto-create the branch, case (3).(b).
1000 */
1001 int recover_with_dwim = dwim_new_local_branch_ok;
1002
1003 if (!has_dash_dash &&
1004 (check_filename(opts->prefix, arg) || !no_wildcard(arg)))
1005 recover_with_dwim = 0;
1006 /*
1007 * Accept "git checkout foo" and "git checkout foo --"
1008 * as candidates for dwim.
1009 */
1010 if (!(argc == 1 && !has_dash_dash) &&
1011 !(argc == 2 && has_dash_dash))
1012 recover_with_dwim = 0;
1013
1014 if (recover_with_dwim) {
1015 const char *remote = unique_tracking_name(arg, rev);
1016 if (remote) {
1017 *new_branch = arg;
1018 arg = remote;
1019 /* DWIMmed to create local branch, case (3).(b) */
1020 } else {
1021 recover_with_dwim = 0;
1022 }
1023 }
1024
1025 if (!recover_with_dwim) {
1026 if (has_dash_dash)
1027 die(_("invalid reference: %s"), arg);
1028 return argcount;
1029 }
1030 }
1031
1032 /* we can't end up being in (2) anymore, eat the argument */
1033 argcount++;
1034 argv++;
1035 argc--;
1036
1037 new->name = arg;
1038 setup_branch_path(new);
1039
1040 if (!check_refname_format(new->path, 0) &&
1041 !read_ref(new->path, branch_rev.hash))
1042 oidcpy(rev, &branch_rev);
1043 else
1044 new->path = NULL; /* not an existing branch */
1045
1046 new->commit = lookup_commit_reference_gently(rev, 1);
1047 if (!new->commit) {
1048 /* not a commit */
1049 *source_tree = parse_tree_indirect(rev);
1050 } else {
1051 parse_commit_or_die(new->commit);
1052 *source_tree = new->commit->tree;
1053 }
1054
1055 if (!*source_tree) /* case (1): want a tree */
1056 die(_("reference is not a tree: %s"), arg);
1057 if (!has_dash_dash) { /* case (3).(d) -> (1) */
1058 /*
1059 * Do not complain the most common case
1060 * git checkout branch
1061 * even if there happen to be a file called 'branch';
1062 * it would be extremely annoying.
1063 */
1064 if (argc)
1065 verify_non_filename(opts->prefix, arg);
1066 } else {
1067 argcount++;
1068 argv++;
1069 argc--;
1070 }
1071
1072 return argcount;
1073 }
1074
1075 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1076 {
1077 int status;
1078 struct strbuf branch_ref = STRBUF_INIT;
1079
1080 if (!opts->new_branch)
1081 die(_("You are on a branch yet to be born"));
1082 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1083 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1084 strbuf_release(&branch_ref);
1085 if (!opts->quiet)
1086 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1087 opts->new_branch);
1088 return status;
1089 }
1090
1091 static int checkout_branch(struct checkout_opts *opts,
1092 struct branch_info *new)
1093 {
1094 if (opts->pathspec.nr)
1095 die(_("paths cannot be used with switching branches"));
1096
1097 if (opts->patch_mode)
1098 die(_("'%s' cannot be used with switching branches"),
1099 "--patch");
1100
1101 if (opts->writeout_stage)
1102 die(_("'%s' cannot be used with switching branches"),
1103 "--ours/--theirs");
1104
1105 if (opts->force && opts->merge)
1106 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1107
1108 if (opts->force_detach && opts->new_branch)
1109 die(_("'%s' cannot be used with '%s'"),
1110 "--detach", "-b/-B/--orphan");
1111
1112 if (opts->new_orphan_branch) {
1113 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1114 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1115 } else if (opts->force_detach) {
1116 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1117 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1118 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1119 opts->track = git_branch_track;
1120
1121 if (new->name && !new->commit)
1122 die(_("Cannot switch branch to a non-commit '%s'"),
1123 new->name);
1124
1125 if (new->path && !opts->force_detach && !opts->new_branch &&
1126 !opts->ignore_other_worktrees) {
1127 int flag;
1128 char *head_ref = resolve_refdup("HEAD", 0, NULL, &flag);
1129 if (head_ref &&
1130 (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)))
1131 die_if_checked_out(new->path, 1);
1132 free(head_ref);
1133 }
1134
1135 if (!new->commit && opts->new_branch) {
1136 struct object_id rev;
1137 int flag;
1138
1139 if (!read_ref_full("HEAD", 0, rev.hash, &flag) &&
1140 (flag & REF_ISSYMREF) && is_null_oid(&rev))
1141 return switch_unborn_to_new_branch(opts);
1142 }
1143 return switch_branches(opts, new);
1144 }
1145
1146 int cmd_checkout(int argc, const char **argv, const char *prefix)
1147 {
1148 struct checkout_opts opts;
1149 struct branch_info new;
1150 char *conflict_style = NULL;
1151 int dwim_new_local_branch = 1;
1152 struct option options[] = {
1153 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1154 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1155 N_("create and checkout a new branch")),
1156 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1157 N_("create/reset and checkout a branch")),
1158 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1159 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach HEAD at named commit")),
1160 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1161 BRANCH_TRACK_EXPLICIT),
1162 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1163 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1164 2),
1165 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1166 3),
1167 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1168 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1169 OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1170 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1171 N_("conflict style (merge or diff3)")),
1172 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1173 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1174 N_("do not limit pathspecs to sparse entries only")),
1175 OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1176 N_("second guess 'git checkout <no-such-branch>'")),
1177 OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1178 N_("do not check if another worktree is holding the given ref")),
1179 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
1180 "checkout", "control recursive updating of submodules",
1181 PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
1182 OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
1183 OPT_END(),
1184 };
1185
1186 memset(&opts, 0, sizeof(opts));
1187 memset(&new, 0, sizeof(new));
1188 opts.overwrite_ignore = 1;
1189 opts.prefix = prefix;
1190 opts.show_progress = -1;
1191
1192 git_config(git_checkout_config, &opts);
1193
1194 opts.track = BRANCH_TRACK_UNSPECIFIED;
1195
1196 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1197 PARSE_OPT_KEEP_DASHDASH);
1198
1199 if (opts.show_progress < 0) {
1200 if (opts.quiet)
1201 opts.show_progress = 0;
1202 else
1203 opts.show_progress = isatty(2);
1204 }
1205
1206 if (conflict_style) {
1207 opts.merge = 1; /* implied */
1208 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1209 }
1210
1211 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1212 die(_("-b, -B and --orphan are mutually exclusive"));
1213
1214 /*
1215 * From here on, new_branch will contain the branch to be checked out,
1216 * and new_branch_force and new_orphan_branch will tell us which one of
1217 * -b/-B/--orphan is being used.
1218 */
1219 if (opts.new_branch_force)
1220 opts.new_branch = opts.new_branch_force;
1221
1222 if (opts.new_orphan_branch)
1223 opts.new_branch = opts.new_orphan_branch;
1224
1225 /* --track without -b/-B/--orphan should DWIM */
1226 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1227 const char *argv0 = argv[0];
1228 if (!argc || !strcmp(argv0, "--"))
1229 die (_("--track needs a branch name"));
1230 skip_prefix(argv0, "refs/", &argv0);
1231 skip_prefix(argv0, "remotes/", &argv0);
1232 argv0 = strchr(argv0, '/');
1233 if (!argv0 || !argv0[1])
1234 die (_("Missing branch name; try -b"));
1235 opts.new_branch = argv0 + 1;
1236 }
1237
1238 /*
1239 * Extract branch name from command line arguments, so
1240 * all that is left is pathspecs.
1241 *
1242 * Handle
1243 *
1244 * 1) git checkout <tree> -- [<paths>]
1245 * 2) git checkout -- [<paths>]
1246 * 3) git checkout <something> [<paths>]
1247 *
1248 * including "last branch" syntax and DWIM-ery for names of
1249 * remote branches, erroring out for invalid or ambiguous cases.
1250 */
1251 if (argc) {
1252 struct object_id rev;
1253 int dwim_ok =
1254 !opts.patch_mode &&
1255 dwim_new_local_branch &&
1256 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1257 !opts.new_branch;
1258 int n = parse_branchname_arg(argc, argv, dwim_ok,
1259 &new, &opts, &rev);
1260 argv += n;
1261 argc -= n;
1262 }
1263
1264 if (argc) {
1265 parse_pathspec(&opts.pathspec, 0,
1266 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1267 prefix, argv);
1268
1269 if (!opts.pathspec.nr)
1270 die(_("invalid path specification"));
1271
1272 /*
1273 * Try to give more helpful suggestion.
1274 * new_branch && argc > 1 will be caught later.
1275 */
1276 if (opts.new_branch && argc == 1)
1277 die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
1278 argv[0], opts.new_branch);
1279
1280 if (opts.force_detach)
1281 die(_("git checkout: --detach does not take a path argument '%s'"),
1282 argv[0]);
1283
1284 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1285 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1286 "checking out of the index."));
1287 }
1288
1289 if (opts.new_branch) {
1290 struct strbuf buf = STRBUF_INIT;
1291
1292 opts.branch_exists =
1293 validate_new_branchname(opts.new_branch, &buf,
1294 !!opts.new_branch_force,
1295 !!opts.new_branch_force);
1296
1297 strbuf_release(&buf);
1298 }
1299
1300 UNLEAK(opts);
1301 if (opts.patch_mode || opts.pathspec.nr)
1302 return checkout_paths(&opts, new.name);
1303 else
1304 return checkout_branch(&opts, &new);
1305 }