Merge branch 'nd/checkout-m-doc-update'
[git/git.git] / builtin / checkout.c
1 #define USE_THE_INDEX_COMPATIBILITY_MACROS
2 #include "builtin.h"
3 #include "config.h"
4 #include "checkout.h"
5 #include "lockfile.h"
6 #include "parse-options.h"
7 #include "refs.h"
8 #include "object-store.h"
9 #include "commit.h"
10 #include "tree.h"
11 #include "tree-walk.h"
12 #include "cache-tree.h"
13 #include "unpack-trees.h"
14 #include "dir.h"
15 #include "run-command.h"
16 #include "merge-recursive.h"
17 #include "branch.h"
18 #include "diff.h"
19 #include "revision.h"
20 #include "remote.h"
21 #include "blob.h"
22 #include "xdiff-interface.h"
23 #include "ll-merge.h"
24 #include "resolve-undo.h"
25 #include "submodule-config.h"
26 #include "submodule.h"
27 #include "advice.h"
28
29 static int checkout_optimize_new_branch;
30
31 static const char * const checkout_usage[] = {
32 N_("git checkout [<options>] <branch>"),
33 N_("git checkout [<options>] [<branch>] -- <file>..."),
34 NULL,
35 };
36
37 struct checkout_opts {
38 int patch_mode;
39 int quiet;
40 int merge;
41 int force;
42 int force_detach;
43 int writeout_stage;
44 int overwrite_ignore;
45 int ignore_skipworktree;
46 int ignore_other_worktrees;
47 int show_progress;
48 int count_checkout_paths;
49 int overlay_mode;
50 /*
51 * If new checkout options are added, skip_merge_working_tree
52 * should be updated accordingly.
53 */
54
55 const char *new_branch;
56 const char *new_branch_force;
57 const char *new_orphan_branch;
58 int new_branch_log;
59 enum branch_track track;
60 struct diff_options diff_options;
61
62 int branch_exists;
63 const char *prefix;
64 struct pathspec pathspec;
65 struct tree *source_tree;
66 };
67
68 static int post_checkout_hook(struct commit *old_commit, struct commit *new_commit,
69 int changed)
70 {
71 return run_hook_le(NULL, "post-checkout",
72 oid_to_hex(old_commit ? &old_commit->object.oid : &null_oid),
73 oid_to_hex(new_commit ? &new_commit->object.oid : &null_oid),
74 changed ? "1" : "0", NULL);
75 /* "new_commit" can be NULL when checking out from the index before
76 a commit exists. */
77
78 }
79
80 static int update_some(const struct object_id *oid, struct strbuf *base,
81 const char *pathname, unsigned mode, int stage, void *context)
82 {
83 int len;
84 struct cache_entry *ce;
85 int pos;
86
87 if (S_ISDIR(mode))
88 return READ_TREE_RECURSIVE;
89
90 len = base->len + strlen(pathname);
91 ce = make_empty_cache_entry(&the_index, len);
92 oidcpy(&ce->oid, oid);
93 memcpy(ce->name, base->buf, base->len);
94 memcpy(ce->name + base->len, pathname, len - base->len);
95 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
96 ce->ce_namelen = len;
97 ce->ce_mode = create_ce_mode(mode);
98
99 /*
100 * If the entry is the same as the current index, we can leave the old
101 * entry in place. Whether it is UPTODATE or not, checkout_entry will
102 * do the right thing.
103 */
104 pos = cache_name_pos(ce->name, ce->ce_namelen);
105 if (pos >= 0) {
106 struct cache_entry *old = active_cache[pos];
107 if (ce->ce_mode == old->ce_mode &&
108 oideq(&ce->oid, &old->oid)) {
109 old->ce_flags |= CE_UPDATE;
110 discard_cache_entry(ce);
111 return 0;
112 }
113 }
114
115 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
116 return 0;
117 }
118
119 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
120 {
121 read_tree_recursive(the_repository, tree, "", 0, 0,
122 pathspec, update_some, NULL);
123
124 /* update the index with the given tree's info
125 * for all args, expanding wildcards, and exit
126 * with any non-zero return code.
127 */
128 return 0;
129 }
130
131 static int skip_same_name(const struct cache_entry *ce, int pos)
132 {
133 while (++pos < active_nr &&
134 !strcmp(active_cache[pos]->name, ce->name))
135 ; /* skip */
136 return pos;
137 }
138
139 static int check_stage(int stage, const struct cache_entry *ce, int pos,
140 int overlay_mode)
141 {
142 while (pos < active_nr &&
143 !strcmp(active_cache[pos]->name, ce->name)) {
144 if (ce_stage(active_cache[pos]) == stage)
145 return 0;
146 pos++;
147 }
148 if (!overlay_mode)
149 return 0;
150 if (stage == 2)
151 return error(_("path '%s' does not have our version"), ce->name);
152 else
153 return error(_("path '%s' does not have their version"), ce->name);
154 }
155
156 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
157 {
158 unsigned seen = 0;
159 const char *name = ce->name;
160
161 while (pos < active_nr) {
162 ce = active_cache[pos];
163 if (strcmp(name, ce->name))
164 break;
165 seen |= (1 << ce_stage(ce));
166 pos++;
167 }
168 if ((stages & seen) != stages)
169 return error(_("path '%s' does not have all necessary versions"),
170 name);
171 return 0;
172 }
173
174 static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
175 const struct checkout *state, int *nr_checkouts,
176 int overlay_mode)
177 {
178 while (pos < active_nr &&
179 !strcmp(active_cache[pos]->name, ce->name)) {
180 if (ce_stage(active_cache[pos]) == stage)
181 return checkout_entry(active_cache[pos], state,
182 NULL, nr_checkouts);
183 pos++;
184 }
185 if (!overlay_mode) {
186 unlink_entry(ce);
187 return 0;
188 }
189 if (stage == 2)
190 return error(_("path '%s' does not have our version"), ce->name);
191 else
192 return error(_("path '%s' does not have their version"), ce->name);
193 }
194
195 static int checkout_merged(int pos, const struct checkout *state, int *nr_checkouts)
196 {
197 struct cache_entry *ce = active_cache[pos];
198 const char *path = ce->name;
199 mmfile_t ancestor, ours, theirs;
200 int status;
201 struct object_id oid;
202 mmbuffer_t result_buf;
203 struct object_id threeway[3];
204 unsigned mode = 0;
205
206 memset(threeway, 0, sizeof(threeway));
207 while (pos < active_nr) {
208 int stage;
209 stage = ce_stage(ce);
210 if (!stage || strcmp(path, ce->name))
211 break;
212 oidcpy(&threeway[stage - 1], &ce->oid);
213 if (stage == 2)
214 mode = create_ce_mode(ce->ce_mode);
215 pos++;
216 ce = active_cache[pos];
217 }
218 if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
219 return error(_("path '%s' does not have necessary versions"), path);
220
221 read_mmblob(&ancestor, &threeway[0]);
222 read_mmblob(&ours, &threeway[1]);
223 read_mmblob(&theirs, &threeway[2]);
224
225 /*
226 * NEEDSWORK: re-create conflicts from merges with
227 * merge.renormalize set, too
228 */
229 status = ll_merge(&result_buf, path, &ancestor, "base",
230 &ours, "ours", &theirs, "theirs",
231 state->istate, NULL);
232 free(ancestor.ptr);
233 free(ours.ptr);
234 free(theirs.ptr);
235 if (status < 0 || !result_buf.ptr) {
236 free(result_buf.ptr);
237 return error(_("path '%s': cannot merge"), path);
238 }
239
240 /*
241 * NEEDSWORK:
242 * There is absolutely no reason to write this as a blob object
243 * and create a phony cache entry. This hack is primarily to get
244 * to the write_entry() machinery that massages the contents to
245 * work-tree format and writes out which only allows it for a
246 * cache entry. The code in write_entry() needs to be refactored
247 * to allow us to feed a <buffer, size, mode> instead of a cache
248 * entry. Such a refactoring would help merge_recursive as well
249 * (it also writes the merge result to the object database even
250 * when it may contain conflicts).
251 */
252 if (write_object_file(result_buf.ptr, result_buf.size, blob_type, &oid))
253 die(_("Unable to add merge result for '%s'"), path);
254 free(result_buf.ptr);
255 ce = make_transient_cache_entry(mode, &oid, path, 2);
256 if (!ce)
257 die(_("make_cache_entry failed for path '%s'"), path);
258 status = checkout_entry(ce, state, NULL, nr_checkouts);
259 discard_cache_entry(ce);
260 return status;
261 }
262
263 static void mark_ce_for_checkout_overlay(struct cache_entry *ce,
264 char *ps_matched,
265 const struct checkout_opts *opts)
266 {
267 ce->ce_flags &= ~CE_MATCHED;
268 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
269 return;
270 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
271 /*
272 * "git checkout tree-ish -- path", but this entry
273 * is in the original index but is not in tree-ish
274 * or does not match the pathspec; it will not be
275 * checked out to the working tree. We will not do
276 * anything to this entry at all.
277 */
278 return;
279 /*
280 * Either this entry came from the tree-ish we are
281 * checking the paths out of, or we are checking out
282 * of the index.
283 *
284 * If it comes from the tree-ish, we already know it
285 * matches the pathspec and could just stamp
286 * CE_MATCHED to it from update_some(). But we still
287 * need ps_matched and read_tree_recursive (and
288 * eventually tree_entry_interesting) cannot fill
289 * ps_matched yet. Once it can, we can avoid calling
290 * match_pathspec() for _all_ entries when
291 * opts->source_tree != NULL.
292 */
293 if (ce_path_match(&the_index, ce, &opts->pathspec, ps_matched))
294 ce->ce_flags |= CE_MATCHED;
295 }
296
297 static void mark_ce_for_checkout_no_overlay(struct cache_entry *ce,
298 char *ps_matched,
299 const struct checkout_opts *opts)
300 {
301 ce->ce_flags &= ~CE_MATCHED;
302 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
303 return;
304 if (ce_path_match(&the_index, ce, &opts->pathspec, ps_matched)) {
305 ce->ce_flags |= CE_MATCHED;
306 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
307 /*
308 * In overlay mode, but the path is not in
309 * tree-ish, which means we should remove it
310 * from the index and the working tree.
311 */
312 ce->ce_flags |= CE_REMOVE | CE_WT_REMOVE;
313 }
314 }
315
316 static int checkout_paths(const struct checkout_opts *opts,
317 const char *revision)
318 {
319 int pos;
320 struct checkout state = CHECKOUT_INIT;
321 static char *ps_matched;
322 struct object_id rev;
323 struct commit *head;
324 int errs = 0;
325 struct lock_file lock_file = LOCK_INIT;
326 int nr_checkouts = 0, nr_unmerged = 0;
327
328 trace2_cmd_mode(opts->patch_mode ? "patch" : "path");
329
330 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
331 die(_("'%s' cannot be used with updating paths"), "--track");
332
333 if (opts->new_branch_log)
334 die(_("'%s' cannot be used with updating paths"), "-l");
335
336 if (opts->force && opts->patch_mode)
337 die(_("'%s' cannot be used with updating paths"), "-f");
338
339 if (opts->force_detach)
340 die(_("'%s' cannot be used with updating paths"), "--detach");
341
342 if (opts->merge && opts->patch_mode)
343 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
344
345 if (opts->force && opts->merge)
346 die(_("'%s' cannot be used with %s"), "-f", "-m");
347
348 if (opts->new_branch)
349 die(_("Cannot update paths and switch to branch '%s' at the same time."),
350 opts->new_branch);
351
352 if (opts->patch_mode)
353 return run_add_interactive(revision, "--patch=checkout",
354 &opts->pathspec);
355
356 repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
357 if (read_cache_preload(&opts->pathspec) < 0)
358 return error(_("index file corrupt"));
359
360 if (opts->source_tree)
361 read_tree_some(opts->source_tree, &opts->pathspec);
362
363 ps_matched = xcalloc(opts->pathspec.nr, 1);
364
365 /*
366 * Make sure all pathspecs participated in locating the paths
367 * to be checked out.
368 */
369 for (pos = 0; pos < active_nr; pos++)
370 if (opts->overlay_mode)
371 mark_ce_for_checkout_overlay(active_cache[pos],
372 ps_matched,
373 opts);
374 else
375 mark_ce_for_checkout_no_overlay(active_cache[pos],
376 ps_matched,
377 opts);
378
379 if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
380 free(ps_matched);
381 return 1;
382 }
383 free(ps_matched);
384
385 /* "checkout -m path" to recreate conflicted state */
386 if (opts->merge)
387 unmerge_marked_index(&the_index);
388
389 /* Any unmerged paths? */
390 for (pos = 0; pos < active_nr; pos++) {
391 const struct cache_entry *ce = active_cache[pos];
392 if (ce->ce_flags & CE_MATCHED) {
393 if (!ce_stage(ce))
394 continue;
395 if (opts->force) {
396 warning(_("path '%s' is unmerged"), ce->name);
397 } else if (opts->writeout_stage) {
398 errs |= check_stage(opts->writeout_stage, ce, pos, opts->overlay_mode);
399 } else if (opts->merge) {
400 errs |= check_stages((1<<2) | (1<<3), ce, pos);
401 } else {
402 errs = 1;
403 error(_("path '%s' is unmerged"), ce->name);
404 }
405 pos = skip_same_name(ce, pos) - 1;
406 }
407 }
408 if (errs)
409 return 1;
410
411 /* Now we are committed to check them out */
412 state.force = 1;
413 state.refresh_cache = 1;
414 state.istate = &the_index;
415
416 enable_delayed_checkout(&state);
417 for (pos = 0; pos < active_nr; pos++) {
418 struct cache_entry *ce = active_cache[pos];
419 if (ce->ce_flags & CE_MATCHED) {
420 if (!ce_stage(ce)) {
421 errs |= checkout_entry(ce, &state,
422 NULL, &nr_checkouts);
423 continue;
424 }
425 if (opts->writeout_stage)
426 errs |= checkout_stage(opts->writeout_stage,
427 ce, pos,
428 &state,
429 &nr_checkouts, opts->overlay_mode);
430 else if (opts->merge)
431 errs |= checkout_merged(pos, &state,
432 &nr_unmerged);
433 pos = skip_same_name(ce, pos) - 1;
434 }
435 }
436 remove_marked_cache_entries(&the_index, 1);
437 remove_scheduled_dirs();
438 errs |= finish_delayed_checkout(&state, &nr_checkouts);
439
440 if (opts->count_checkout_paths) {
441 if (nr_unmerged)
442 fprintf_ln(stderr, Q_("Recreated %d merge conflict",
443 "Recreated %d merge conflicts",
444 nr_unmerged),
445 nr_unmerged);
446 if (opts->source_tree)
447 fprintf_ln(stderr, Q_("Updated %d path from %s",
448 "Updated %d paths from %s",
449 nr_checkouts),
450 nr_checkouts,
451 find_unique_abbrev(&opts->source_tree->object.oid,
452 DEFAULT_ABBREV));
453 else if (!nr_unmerged || nr_checkouts)
454 fprintf_ln(stderr, Q_("Updated %d path from the index",
455 "Updated %d paths from the index",
456 nr_checkouts),
457 nr_checkouts);
458 }
459
460 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
461 die(_("unable to write new index file"));
462
463 read_ref_full("HEAD", 0, &rev, NULL);
464 head = lookup_commit_reference_gently(the_repository, &rev, 1);
465
466 errs |= post_checkout_hook(head, head, 0);
467 return errs;
468 }
469
470 static void show_local_changes(struct object *head,
471 const struct diff_options *opts)
472 {
473 struct rev_info rev;
474 /* I think we want full paths, even if we're in a subdirectory. */
475 repo_init_revisions(the_repository, &rev, NULL);
476 rev.diffopt.flags = opts->flags;
477 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
478 diff_setup_done(&rev.diffopt);
479 add_pending_object(&rev, head, NULL);
480 run_diff_index(&rev, 0);
481 }
482
483 static void describe_detached_head(const char *msg, struct commit *commit)
484 {
485 struct strbuf sb = STRBUF_INIT;
486
487 if (!parse_commit(commit))
488 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
489 if (print_sha1_ellipsis()) {
490 fprintf(stderr, "%s %s... %s\n", msg,
491 find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
492 } else {
493 fprintf(stderr, "%s %s %s\n", msg,
494 find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
495 }
496 strbuf_release(&sb);
497 }
498
499 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
500 int worktree, int *writeout_error)
501 {
502 struct unpack_trees_options opts;
503 struct tree_desc tree_desc;
504
505 memset(&opts, 0, sizeof(opts));
506 opts.head_idx = -1;
507 opts.update = worktree;
508 opts.skip_unmerged = !worktree;
509 opts.reset = 1;
510 opts.merge = 1;
511 opts.fn = oneway_merge;
512 opts.verbose_update = o->show_progress;
513 opts.src_index = &the_index;
514 opts.dst_index = &the_index;
515 parse_tree(tree);
516 init_tree_desc(&tree_desc, tree->buffer, tree->size);
517 switch (unpack_trees(1, &tree_desc, &opts)) {
518 case -2:
519 *writeout_error = 1;
520 /*
521 * We return 0 nevertheless, as the index is all right
522 * and more importantly we have made best efforts to
523 * update paths in the work tree, and we cannot revert
524 * them.
525 */
526 /* fallthrough */
527 case 0:
528 return 0;
529 default:
530 return 128;
531 }
532 }
533
534 struct branch_info {
535 const char *name; /* The short name used */
536 const char *path; /* The full name of a real branch */
537 struct commit *commit; /* The named commit */
538 /*
539 * if not null the branch is detached because it's already
540 * checked out in this checkout
541 */
542 char *checkout;
543 };
544
545 static void setup_branch_path(struct branch_info *branch)
546 {
547 struct strbuf buf = STRBUF_INIT;
548
549 strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
550 if (strcmp(buf.buf, branch->name))
551 branch->name = xstrdup(buf.buf);
552 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
553 branch->path = strbuf_detach(&buf, NULL);
554 }
555
556 /*
557 * Skip merging the trees, updating the index and working directory if and
558 * only if we are creating a new branch via "git checkout -b <new_branch>."
559 */
560 static int skip_merge_working_tree(const struct checkout_opts *opts,
561 const struct branch_info *old_branch_info,
562 const struct branch_info *new_branch_info)
563 {
564 /*
565 * Do the merge if sparse checkout is on and the user has not opted in
566 * to the optimized behavior
567 */
568 if (core_apply_sparse_checkout && !checkout_optimize_new_branch)
569 return 0;
570
571 /*
572 * We must do the merge if we are actually moving to a new commit.
573 */
574 if (!old_branch_info->commit || !new_branch_info->commit ||
575 !oideq(&old_branch_info->commit->object.oid,
576 &new_branch_info->commit->object.oid))
577 return 0;
578
579 /*
580 * opts->patch_mode cannot be used with switching branches so is
581 * not tested here
582 */
583
584 /*
585 * opts->quiet only impacts output so doesn't require a merge
586 */
587
588 /*
589 * Honor the explicit request for a three-way merge or to throw away
590 * local changes
591 */
592 if (opts->merge || opts->force)
593 return 0;
594
595 /*
596 * --detach is documented as "updating the index and the files in the
597 * working tree" but this optimization skips those steps so fall through
598 * to the regular code path.
599 */
600 if (opts->force_detach)
601 return 0;
602
603 /*
604 * opts->writeout_stage cannot be used with switching branches so is
605 * not tested here
606 */
607
608 /*
609 * Honor the explicit ignore requests
610 */
611 if (!opts->overwrite_ignore || opts->ignore_skipworktree ||
612 opts->ignore_other_worktrees)
613 return 0;
614
615 /*
616 * opts->show_progress only impacts output so doesn't require a merge
617 */
618
619 /*
620 * opts->overlay_mode cannot be used with switching branches so is
621 * not tested here
622 */
623
624 /*
625 * If we aren't creating a new branch any changes or updates will
626 * happen in the existing branch. Since that could only be updating
627 * the index and working directory, we don't want to skip those steps
628 * or we've defeated any purpose in running the command.
629 */
630 if (!opts->new_branch)
631 return 0;
632
633 /*
634 * new_branch_force is defined to "create/reset and checkout a branch"
635 * so needs to go through the merge to do the reset
636 */
637 if (opts->new_branch_force)
638 return 0;
639
640 /*
641 * A new orphaned branch requrires the index and the working tree to be
642 * adjusted to <start_point>
643 */
644 if (opts->new_orphan_branch)
645 return 0;
646
647 /*
648 * Remaining variables are not checkout options but used to track state
649 */
650
651 /*
652 * Do the merge if this is the initial checkout. We cannot use
653 * is_cache_unborn() here because the index hasn't been loaded yet
654 * so cache_nr and timestamp.sec are always zero.
655 */
656 if (!file_exists(get_index_file()))
657 return 0;
658
659 return 1;
660 }
661
662 static int merge_working_tree(const struct checkout_opts *opts,
663 struct branch_info *old_branch_info,
664 struct branch_info *new_branch_info,
665 int *writeout_error)
666 {
667 int ret;
668 struct lock_file lock_file = LOCK_INIT;
669
670 hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
671 if (read_cache_preload(NULL) < 0)
672 return error(_("index file corrupt"));
673
674 resolve_undo_clear();
675 if (opts->force) {
676 ret = reset_tree(get_commit_tree(new_branch_info->commit),
677 opts, 1, writeout_error);
678 if (ret)
679 return ret;
680 } else {
681 struct tree_desc trees[2];
682 struct tree *tree;
683 struct unpack_trees_options topts;
684
685 memset(&topts, 0, sizeof(topts));
686 topts.head_idx = -1;
687 topts.src_index = &the_index;
688 topts.dst_index = &the_index;
689
690 setup_unpack_trees_porcelain(&topts, "checkout");
691
692 refresh_cache(REFRESH_QUIET);
693
694 if (unmerged_cache()) {
695 error(_("you need to resolve your current index first"));
696 return 1;
697 }
698
699 /* 2-way merge to the new branch */
700 topts.initial_checkout = is_cache_unborn();
701 topts.update = 1;
702 topts.merge = 1;
703 topts.gently = opts->merge && old_branch_info->commit;
704 topts.verbose_update = opts->show_progress;
705 topts.fn = twoway_merge;
706 if (opts->overwrite_ignore) {
707 topts.dir = xcalloc(1, sizeof(*topts.dir));
708 topts.dir->flags |= DIR_SHOW_IGNORED;
709 setup_standard_excludes(topts.dir);
710 }
711 tree = parse_tree_indirect(old_branch_info->commit ?
712 &old_branch_info->commit->object.oid :
713 the_hash_algo->empty_tree);
714 init_tree_desc(&trees[0], tree->buffer, tree->size);
715 tree = parse_tree_indirect(&new_branch_info->commit->object.oid);
716 init_tree_desc(&trees[1], tree->buffer, tree->size);
717
718 ret = unpack_trees(2, trees, &topts);
719 clear_unpack_trees_porcelain(&topts);
720 if (ret == -1) {
721 /*
722 * Unpack couldn't do a trivial merge; either
723 * give up or do a real merge, depending on
724 * whether the merge flag was used.
725 */
726 struct tree *result;
727 struct tree *work;
728 struct merge_options o;
729 struct strbuf sb = STRBUF_INIT;
730
731 if (!opts->merge)
732 return 1;
733
734 /*
735 * Without old_branch_info->commit, the below is the same as
736 * the two-tree unpack we already tried and failed.
737 */
738 if (!old_branch_info->commit)
739 return 1;
740
741 if (repo_index_has_changes(the_repository,
742 get_commit_tree(old_branch_info->commit),
743 &sb))
744 warning(_("staged changes in the following files may be lost: %s"),
745 sb.buf);
746 strbuf_release(&sb);
747
748 /* Do more real merge */
749
750 /*
751 * We update the index fully, then write the
752 * tree from the index, then merge the new
753 * branch with the current tree, with the old
754 * branch as the base. Then we reset the index
755 * (but not the working tree) to the new
756 * branch, leaving the working tree as the
757 * merged version, but skipping unmerged
758 * entries in the index.
759 */
760
761 add_files_to_cache(NULL, NULL, 0);
762 /*
763 * NEEDSWORK: carrying over local changes
764 * when branches have different end-of-line
765 * normalization (or clean+smudge rules) is
766 * a pain; plumb in an option to set
767 * o.renormalize?
768 */
769 init_merge_options(&o, the_repository);
770 o.verbosity = 0;
771 work = write_tree_from_memory(&o);
772
773 ret = reset_tree(get_commit_tree(new_branch_info->commit),
774 opts, 1,
775 writeout_error);
776 if (ret)
777 return ret;
778 o.ancestor = old_branch_info->name;
779 o.branch1 = new_branch_info->name;
780 o.branch2 = "local";
781 ret = merge_trees(&o,
782 get_commit_tree(new_branch_info->commit),
783 work,
784 get_commit_tree(old_branch_info->commit),
785 &result);
786 if (ret < 0)
787 exit(128);
788 ret = reset_tree(get_commit_tree(new_branch_info->commit),
789 opts, 0,
790 writeout_error);
791 strbuf_release(&o.obuf);
792 if (ret)
793 return ret;
794 }
795 }
796
797 if (!active_cache_tree)
798 active_cache_tree = cache_tree();
799
800 if (!cache_tree_fully_valid(active_cache_tree))
801 cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
802
803 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
804 die(_("unable to write new index file"));
805
806 if (!opts->force && !opts->quiet)
807 show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
808
809 return 0;
810 }
811
812 static void report_tracking(struct branch_info *new_branch_info)
813 {
814 struct strbuf sb = STRBUF_INIT;
815 struct branch *branch = branch_get(new_branch_info->name);
816
817 if (!format_tracking_info(branch, &sb, AHEAD_BEHIND_FULL))
818 return;
819 fputs(sb.buf, stdout);
820 strbuf_release(&sb);
821 }
822
823 static void update_refs_for_switch(const struct checkout_opts *opts,
824 struct branch_info *old_branch_info,
825 struct branch_info *new_branch_info)
826 {
827 struct strbuf msg = STRBUF_INIT;
828 const char *old_desc, *reflog_msg;
829 if (opts->new_branch) {
830 if (opts->new_orphan_branch) {
831 char *refname;
832
833 refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
834 if (opts->new_branch_log &&
835 !should_autocreate_reflog(refname)) {
836 int ret;
837 struct strbuf err = STRBUF_INIT;
838
839 ret = safe_create_reflog(refname, 1, &err);
840 if (ret) {
841 fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
842 opts->new_orphan_branch, err.buf);
843 strbuf_release(&err);
844 free(refname);
845 return;
846 }
847 strbuf_release(&err);
848 }
849 free(refname);
850 }
851 else
852 create_branch(the_repository,
853 opts->new_branch, new_branch_info->name,
854 opts->new_branch_force ? 1 : 0,
855 opts->new_branch_force ? 1 : 0,
856 opts->new_branch_log,
857 opts->quiet,
858 opts->track);
859 new_branch_info->name = opts->new_branch;
860 setup_branch_path(new_branch_info);
861 }
862
863 old_desc = old_branch_info->name;
864 if (!old_desc && old_branch_info->commit)
865 old_desc = oid_to_hex(&old_branch_info->commit->object.oid);
866
867 reflog_msg = getenv("GIT_REFLOG_ACTION");
868 if (!reflog_msg)
869 strbuf_addf(&msg, "checkout: moving from %s to %s",
870 old_desc ? old_desc : "(invalid)", new_branch_info->name);
871 else
872 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
873
874 if (!strcmp(new_branch_info->name, "HEAD") && !new_branch_info->path && !opts->force_detach) {
875 /* Nothing to do. */
876 } else if (opts->force_detach || !new_branch_info->path) { /* No longer on any branch. */
877 update_ref(msg.buf, "HEAD", &new_branch_info->commit->object.oid, NULL,
878 REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
879 if (!opts->quiet) {
880 if (old_branch_info->path &&
881 advice_detached_head && !opts->force_detach)
882 detach_advice(new_branch_info->name);
883 describe_detached_head(_("HEAD is now at"), new_branch_info->commit);
884 }
885 } else if (new_branch_info->path) { /* Switch branches. */
886 if (create_symref("HEAD", new_branch_info->path, msg.buf) < 0)
887 die(_("unable to update HEAD"));
888 if (!opts->quiet) {
889 if (old_branch_info->path && !strcmp(new_branch_info->path, old_branch_info->path)) {
890 if (opts->new_branch_force)
891 fprintf(stderr, _("Reset branch '%s'\n"),
892 new_branch_info->name);
893 else
894 fprintf(stderr, _("Already on '%s'\n"),
895 new_branch_info->name);
896 } else if (opts->new_branch) {
897 if (opts->branch_exists)
898 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new_branch_info->name);
899 else
900 fprintf(stderr, _("Switched to a new branch '%s'\n"), new_branch_info->name);
901 } else {
902 fprintf(stderr, _("Switched to branch '%s'\n"),
903 new_branch_info->name);
904 }
905 }
906 if (old_branch_info->path && old_branch_info->name) {
907 if (!ref_exists(old_branch_info->path) && reflog_exists(old_branch_info->path))
908 delete_reflog(old_branch_info->path);
909 }
910 }
911 remove_branch_state(the_repository);
912 strbuf_release(&msg);
913 if (!opts->quiet &&
914 (new_branch_info->path || (!opts->force_detach && !strcmp(new_branch_info->name, "HEAD"))))
915 report_tracking(new_branch_info);
916 }
917
918 static int add_pending_uninteresting_ref(const char *refname,
919 const struct object_id *oid,
920 int flags, void *cb_data)
921 {
922 add_pending_oid(cb_data, refname, oid, UNINTERESTING);
923 return 0;
924 }
925
926 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
927 {
928 strbuf_addstr(sb, " ");
929 strbuf_add_unique_abbrev(sb, &commit->object.oid, DEFAULT_ABBREV);
930 strbuf_addch(sb, ' ');
931 if (!parse_commit(commit))
932 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
933 strbuf_addch(sb, '\n');
934 }
935
936 #define ORPHAN_CUTOFF 4
937 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
938 {
939 struct commit *c, *last = NULL;
940 struct strbuf sb = STRBUF_INIT;
941 int lost = 0;
942 while ((c = get_revision(revs)) != NULL) {
943 if (lost < ORPHAN_CUTOFF)
944 describe_one_orphan(&sb, c);
945 last = c;
946 lost++;
947 }
948 if (ORPHAN_CUTOFF < lost) {
949 int more = lost - ORPHAN_CUTOFF;
950 if (more == 1)
951 describe_one_orphan(&sb, last);
952 else
953 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
954 }
955
956 fprintf(stderr,
957 Q_(
958 /* The singular version */
959 "Warning: you are leaving %d commit behind, "
960 "not connected to\n"
961 "any of your branches:\n\n"
962 "%s\n",
963 /* The plural version */
964 "Warning: you are leaving %d commits behind, "
965 "not connected to\n"
966 "any of your branches:\n\n"
967 "%s\n",
968 /* Give ngettext() the count */
969 lost),
970 lost,
971 sb.buf);
972 strbuf_release(&sb);
973
974 if (advice_detached_head)
975 fprintf(stderr,
976 Q_(
977 /* The singular version */
978 "If you want to keep it by creating a new branch, "
979 "this may be a good time\nto do so with:\n\n"
980 " git branch <new-branch-name> %s\n\n",
981 /* The plural version */
982 "If you want to keep them by creating a new branch, "
983 "this may be a good time\nto do so with:\n\n"
984 " git branch <new-branch-name> %s\n\n",
985 /* Give ngettext() the count */
986 lost),
987 find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV));
988 }
989
990 /*
991 * We are about to leave commit that was at the tip of a detached
992 * HEAD. If it is not reachable from any ref, this is the last chance
993 * for the user to do so without resorting to reflog.
994 */
995 static void orphaned_commit_warning(struct commit *old_commit, struct commit *new_commit)
996 {
997 struct rev_info revs;
998 struct object *object = &old_commit->object;
999
1000 repo_init_revisions(the_repository, &revs, NULL);
1001 setup_revisions(0, NULL, &revs, NULL);
1002
1003 object->flags &= ~UNINTERESTING;
1004 add_pending_object(&revs, object, oid_to_hex(&object->oid));
1005
1006 for_each_ref(add_pending_uninteresting_ref, &revs);
1007 add_pending_oid(&revs, "HEAD", &new_commit->object.oid, UNINTERESTING);
1008
1009 if (prepare_revision_walk(&revs))
1010 die(_("internal error in revision walk"));
1011 if (!(old_commit->object.flags & UNINTERESTING))
1012 suggest_reattach(old_commit, &revs);
1013 else
1014 describe_detached_head(_("Previous HEAD position was"), old_commit);
1015
1016 /* Clean up objects used, as they will be reused. */
1017 clear_commit_marks_all(ALL_REV_FLAGS);
1018 }
1019
1020 static int switch_branches(const struct checkout_opts *opts,
1021 struct branch_info *new_branch_info)
1022 {
1023 int ret = 0;
1024 struct branch_info old_branch_info;
1025 void *path_to_free;
1026 struct object_id rev;
1027 int flag, writeout_error = 0;
1028
1029 trace2_cmd_mode("branch");
1030
1031 memset(&old_branch_info, 0, sizeof(old_branch_info));
1032 old_branch_info.path = path_to_free = resolve_refdup("HEAD", 0, &rev, &flag);
1033 if (old_branch_info.path)
1034 old_branch_info.commit = lookup_commit_reference_gently(the_repository, &rev, 1);
1035 if (!(flag & REF_ISSYMREF))
1036 old_branch_info.path = NULL;
1037
1038 if (old_branch_info.path)
1039 skip_prefix(old_branch_info.path, "refs/heads/", &old_branch_info.name);
1040
1041 if (!new_branch_info->name) {
1042 new_branch_info->name = "HEAD";
1043 new_branch_info->commit = old_branch_info.commit;
1044 if (!new_branch_info->commit)
1045 die(_("You are on a branch yet to be born"));
1046 parse_commit_or_die(new_branch_info->commit);
1047 }
1048
1049 /* optimize the "checkout -b <new_branch> path */
1050 if (skip_merge_working_tree(opts, &old_branch_info, new_branch_info)) {
1051 if (!checkout_optimize_new_branch && !opts->quiet) {
1052 if (read_cache_preload(NULL) < 0)
1053 return error(_("index file corrupt"));
1054 show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
1055 }
1056 } else {
1057 ret = merge_working_tree(opts, &old_branch_info, new_branch_info, &writeout_error);
1058 if (ret) {
1059 free(path_to_free);
1060 return ret;
1061 }
1062 }
1063
1064 if (!opts->quiet && !old_branch_info.path && old_branch_info.commit && new_branch_info->commit != old_branch_info.commit)
1065 orphaned_commit_warning(old_branch_info.commit, new_branch_info->commit);
1066
1067 update_refs_for_switch(opts, &old_branch_info, new_branch_info);
1068
1069 ret = post_checkout_hook(old_branch_info.commit, new_branch_info->commit, 1);
1070 free(path_to_free);
1071 return ret || writeout_error;
1072 }
1073
1074 static int git_checkout_config(const char *var, const char *value, void *cb)
1075 {
1076 if (!strcmp(var, "checkout.optimizenewbranch")) {
1077 checkout_optimize_new_branch = git_config_bool(var, value);
1078 return 0;
1079 }
1080
1081 if (!strcmp(var, "diff.ignoresubmodules")) {
1082 struct checkout_opts *opts = cb;
1083 handle_ignore_submodules_arg(&opts->diff_options, value);
1084 return 0;
1085 }
1086
1087 if (starts_with(var, "submodule."))
1088 return git_default_submodule_config(var, value, NULL);
1089
1090 return git_xmerge_config(var, value, NULL);
1091 }
1092
1093 static int parse_branchname_arg(int argc, const char **argv,
1094 int dwim_new_local_branch_ok,
1095 struct branch_info *new_branch_info,
1096 struct checkout_opts *opts,
1097 struct object_id *rev,
1098 int *dwim_remotes_matched)
1099 {
1100 struct tree **source_tree = &opts->source_tree;
1101 const char **new_branch = &opts->new_branch;
1102 int argcount = 0;
1103 struct object_id branch_rev;
1104 const char *arg;
1105 int dash_dash_pos;
1106 int has_dash_dash = 0;
1107 int i;
1108
1109 /*
1110 * case 1: git checkout <ref> -- [<paths>]
1111 *
1112 * <ref> must be a valid tree, everything after the '--' must be
1113 * a path.
1114 *
1115 * case 2: git checkout -- [<paths>]
1116 *
1117 * everything after the '--' must be paths.
1118 *
1119 * case 3: git checkout <something> [--]
1120 *
1121 * (a) If <something> is a commit, that is to
1122 * switch to the branch or detach HEAD at it. As a special case,
1123 * if <something> is A...B (missing A or B means HEAD but you can
1124 * omit at most one side), and if there is a unique merge base
1125 * between A and B, A...B names that merge base.
1126 *
1127 * (b) If <something> is _not_ a commit, either "--" is present
1128 * or <something> is not a path, no -t or -b was given, and
1129 * and there is a tracking branch whose name is <something>
1130 * in one and only one remote (or if the branch exists on the
1131 * remote named in checkout.defaultRemote), then this is a
1132 * short-hand to fork local <something> from that
1133 * remote-tracking branch.
1134 *
1135 * (c) Otherwise, if "--" is present, treat it like case (1).
1136 *
1137 * (d) Otherwise :
1138 * - if it's a reference, treat it like case (1)
1139 * - else if it's a path, treat it like case (2)
1140 * - else: fail.
1141 *
1142 * case 4: git checkout <something> <paths>
1143 *
1144 * The first argument must not be ambiguous.
1145 * - If it's *only* a reference, treat it like case (1).
1146 * - If it's only a path, treat it like case (2).
1147 * - else: fail.
1148 *
1149 */
1150 if (!argc)
1151 return 0;
1152
1153 arg = argv[0];
1154 dash_dash_pos = -1;
1155 for (i = 0; i < argc; i++) {
1156 if (!strcmp(argv[i], "--")) {
1157 dash_dash_pos = i;
1158 break;
1159 }
1160 }
1161 if (dash_dash_pos == 0)
1162 return 1; /* case (2) */
1163 else if (dash_dash_pos == 1)
1164 has_dash_dash = 1; /* case (3) or (1) */
1165 else if (dash_dash_pos >= 2)
1166 die(_("only one reference expected, %d given."), dash_dash_pos);
1167 opts->count_checkout_paths = !opts->quiet && !has_dash_dash;
1168
1169 if (!strcmp(arg, "-"))
1170 arg = "@{-1}";
1171
1172 if (get_oid_mb(arg, rev)) {
1173 /*
1174 * Either case (3) or (4), with <something> not being
1175 * a commit, or an attempt to use case (1) with an
1176 * invalid ref.
1177 *
1178 * It's likely an error, but we need to find out if
1179 * we should auto-create the branch, case (3).(b).
1180 */
1181 int recover_with_dwim = dwim_new_local_branch_ok;
1182
1183 int could_be_checkout_paths = !has_dash_dash &&
1184 check_filename(opts->prefix, arg);
1185
1186 if (!has_dash_dash && !no_wildcard(arg))
1187 recover_with_dwim = 0;
1188
1189 /*
1190 * Accept "git checkout foo" and "git checkout foo --"
1191 * as candidates for dwim.
1192 */
1193 if (!(argc == 1 && !has_dash_dash) &&
1194 !(argc == 2 && has_dash_dash))
1195 recover_with_dwim = 0;
1196
1197 if (recover_with_dwim) {
1198 const char *remote = unique_tracking_name(arg, rev,
1199 dwim_remotes_matched);
1200 if (remote) {
1201 if (could_be_checkout_paths)
1202 die(_("'%s' could be both a local file and a tracking branch.\n"
1203 "Please use -- (and optionally --no-guess) to disambiguate"),
1204 arg);
1205 *new_branch = arg;
1206 arg = remote;
1207 /* DWIMmed to create local branch, case (3).(b) */
1208 } else {
1209 recover_with_dwim = 0;
1210 }
1211 }
1212
1213 if (!recover_with_dwim) {
1214 if (has_dash_dash)
1215 die(_("invalid reference: %s"), arg);
1216 return argcount;
1217 }
1218 }
1219
1220 /* we can't end up being in (2) anymore, eat the argument */
1221 argcount++;
1222 argv++;
1223 argc--;
1224
1225 new_branch_info->name = arg;
1226 setup_branch_path(new_branch_info);
1227
1228 if (!check_refname_format(new_branch_info->path, 0) &&
1229 !read_ref(new_branch_info->path, &branch_rev))
1230 oidcpy(rev, &branch_rev);
1231 else
1232 new_branch_info->path = NULL; /* not an existing branch */
1233
1234 new_branch_info->commit = lookup_commit_reference_gently(the_repository, rev, 1);
1235 if (!new_branch_info->commit) {
1236 /* not a commit */
1237 *source_tree = parse_tree_indirect(rev);
1238 } else {
1239 parse_commit_or_die(new_branch_info->commit);
1240 *source_tree = get_commit_tree(new_branch_info->commit);
1241 }
1242
1243 if (!*source_tree) /* case (1): want a tree */
1244 die(_("reference is not a tree: %s"), arg);
1245 if (!has_dash_dash) { /* case (3).(d) -> (1) */
1246 /*
1247 * Do not complain the most common case
1248 * git checkout branch
1249 * even if there happen to be a file called 'branch';
1250 * it would be extremely annoying.
1251 */
1252 if (argc)
1253 verify_non_filename(opts->prefix, arg);
1254 } else {
1255 argcount++;
1256 argv++;
1257 argc--;
1258 }
1259
1260 return argcount;
1261 }
1262
1263 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1264 {
1265 int status;
1266 struct strbuf branch_ref = STRBUF_INIT;
1267
1268 trace2_cmd_mode("unborn");
1269
1270 if (!opts->new_branch)
1271 die(_("You are on a branch yet to be born"));
1272 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1273 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1274 strbuf_release(&branch_ref);
1275 if (!opts->quiet)
1276 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1277 opts->new_branch);
1278 return status;
1279 }
1280
1281 static int checkout_branch(struct checkout_opts *opts,
1282 struct branch_info *new_branch_info)
1283 {
1284 if (opts->pathspec.nr)
1285 die(_("paths cannot be used with switching branches"));
1286
1287 if (opts->patch_mode)
1288 die(_("'%s' cannot be used with switching branches"),
1289 "--patch");
1290
1291 if (!opts->overlay_mode)
1292 die(_("'%s' cannot be used with switching branches"),
1293 "--no-overlay");
1294
1295 if (opts->writeout_stage)
1296 die(_("'%s' cannot be used with switching branches"),
1297 "--ours/--theirs");
1298
1299 if (opts->force && opts->merge)
1300 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1301
1302 if (opts->force_detach && opts->new_branch)
1303 die(_("'%s' cannot be used with '%s'"),
1304 "--detach", "-b/-B/--orphan");
1305
1306 if (opts->new_orphan_branch) {
1307 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1308 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1309 } else if (opts->force_detach) {
1310 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1311 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1312 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1313 opts->track = git_branch_track;
1314
1315 if (new_branch_info->name && !new_branch_info->commit)
1316 die(_("Cannot switch branch to a non-commit '%s'"),
1317 new_branch_info->name);
1318
1319 if (new_branch_info->path && !opts->force_detach && !opts->new_branch &&
1320 !opts->ignore_other_worktrees) {
1321 int flag;
1322 char *head_ref = resolve_refdup("HEAD", 0, NULL, &flag);
1323 if (head_ref &&
1324 (!(flag & REF_ISSYMREF) || strcmp(head_ref, new_branch_info->path)))
1325 die_if_checked_out(new_branch_info->path, 1);
1326 free(head_ref);
1327 }
1328
1329 if (!new_branch_info->commit && opts->new_branch) {
1330 struct object_id rev;
1331 int flag;
1332
1333 if (!read_ref_full("HEAD", 0, &rev, &flag) &&
1334 (flag & REF_ISSYMREF) && is_null_oid(&rev))
1335 return switch_unborn_to_new_branch(opts);
1336 }
1337 return switch_branches(opts, new_branch_info);
1338 }
1339
1340 int cmd_checkout(int argc, const char **argv, const char *prefix)
1341 {
1342 struct checkout_opts opts;
1343 struct branch_info new_branch_info;
1344 char *conflict_style = NULL;
1345 int dwim_new_local_branch, no_dwim_new_local_branch = 0;
1346 int dwim_remotes_matched = 0;
1347 struct option options[] = {
1348 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1349 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1350 N_("create and checkout a new branch")),
1351 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1352 N_("create/reset and checkout a branch")),
1353 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1354 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach HEAD at named commit")),
1355 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1356 BRANCH_TRACK_EXPLICIT),
1357 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1358 OPT_SET_INT_F('2', "ours", &opts.writeout_stage,
1359 N_("checkout our version for unmerged files"),
1360 2, PARSE_OPT_NONEG),
1361 OPT_SET_INT_F('3', "theirs", &opts.writeout_stage,
1362 N_("checkout their version for unmerged files"),
1363 3, PARSE_OPT_NONEG),
1364 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)"),
1365 PARSE_OPT_NOCOMPLETE),
1366 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1367 OPT_BOOL_F(0, "overwrite-ignore", &opts.overwrite_ignore,
1368 N_("update ignored files (default)"),
1369 PARSE_OPT_NOCOMPLETE),
1370 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1371 N_("conflict style (merge or diff3)")),
1372 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1373 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1374 N_("do not limit pathspecs to sparse entries only")),
1375 OPT_BOOL(0, "no-guess", &no_dwim_new_local_branch,
1376 N_("do not second guess 'git checkout <no-such-branch>'")),
1377 OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1378 N_("do not check if another worktree is holding the given ref")),
1379 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
1380 "checkout", "control recursive updating of submodules",
1381 PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
1382 OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
1383 OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode (default)")),
1384 OPT_END(),
1385 };
1386
1387 memset(&opts, 0, sizeof(opts));
1388 memset(&new_branch_info, 0, sizeof(new_branch_info));
1389 opts.overwrite_ignore = 1;
1390 opts.prefix = prefix;
1391 opts.show_progress = -1;
1392 opts.overlay_mode = -1;
1393
1394 git_config(git_checkout_config, &opts);
1395
1396 opts.track = BRANCH_TRACK_UNSPECIFIED;
1397
1398 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1399 PARSE_OPT_KEEP_DASHDASH);
1400
1401 dwim_new_local_branch = !no_dwim_new_local_branch;
1402 if (opts.show_progress < 0) {
1403 if (opts.quiet)
1404 opts.show_progress = 0;
1405 else
1406 opts.show_progress = isatty(2);
1407 }
1408
1409 if (conflict_style) {
1410 opts.merge = 1; /* implied */
1411 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1412 }
1413
1414 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1415 die(_("-b, -B and --orphan are mutually exclusive"));
1416
1417 if (opts.overlay_mode == 1 && opts.patch_mode)
1418 die(_("-p and --overlay are mutually exclusive"));
1419
1420 /*
1421 * From here on, new_branch will contain the branch to be checked out,
1422 * and new_branch_force and new_orphan_branch will tell us which one of
1423 * -b/-B/--orphan is being used.
1424 */
1425 if (opts.new_branch_force)
1426 opts.new_branch = opts.new_branch_force;
1427
1428 if (opts.new_orphan_branch)
1429 opts.new_branch = opts.new_orphan_branch;
1430
1431 /* --track without -b/-B/--orphan should DWIM */
1432 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1433 const char *argv0 = argv[0];
1434 if (!argc || !strcmp(argv0, "--"))
1435 die(_("--track needs a branch name"));
1436 skip_prefix(argv0, "refs/", &argv0);
1437 skip_prefix(argv0, "remotes/", &argv0);
1438 argv0 = strchr(argv0, '/');
1439 if (!argv0 || !argv0[1])
1440 die(_("missing branch name; try -b"));
1441 opts.new_branch = argv0 + 1;
1442 }
1443
1444 /*
1445 * Extract branch name from command line arguments, so
1446 * all that is left is pathspecs.
1447 *
1448 * Handle
1449 *
1450 * 1) git checkout <tree> -- [<paths>]
1451 * 2) git checkout -- [<paths>]
1452 * 3) git checkout <something> [<paths>]
1453 *
1454 * including "last branch" syntax and DWIM-ery for names of
1455 * remote branches, erroring out for invalid or ambiguous cases.
1456 */
1457 if (argc) {
1458 struct object_id rev;
1459 int dwim_ok =
1460 !opts.patch_mode &&
1461 dwim_new_local_branch &&
1462 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1463 !opts.new_branch;
1464 int n = parse_branchname_arg(argc, argv, dwim_ok,
1465 &new_branch_info, &opts, &rev,
1466 &dwim_remotes_matched);
1467 argv += n;
1468 argc -= n;
1469 }
1470
1471 if (argc) {
1472 parse_pathspec(&opts.pathspec, 0,
1473 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1474 prefix, argv);
1475
1476 if (!opts.pathspec.nr)
1477 die(_("invalid path specification"));
1478
1479 /*
1480 * Try to give more helpful suggestion.
1481 * new_branch && argc > 1 will be caught later.
1482 */
1483 if (opts.new_branch && argc == 1)
1484 die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
1485 argv[0], opts.new_branch);
1486
1487 if (opts.force_detach)
1488 die(_("git checkout: --detach does not take a path argument '%s'"),
1489 argv[0]);
1490
1491 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1492 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1493 "checking out of the index."));
1494 }
1495
1496 if (opts.new_branch) {
1497 struct strbuf buf = STRBUF_INIT;
1498
1499 if (opts.new_branch_force)
1500 opts.branch_exists = validate_branchname(opts.new_branch, &buf);
1501 else
1502 opts.branch_exists =
1503 validate_new_branchname(opts.new_branch, &buf, 0);
1504 strbuf_release(&buf);
1505 }
1506
1507 UNLEAK(opts);
1508 if (opts.patch_mode || opts.pathspec.nr) {
1509 int ret = checkout_paths(&opts, new_branch_info.name);
1510 if (ret && dwim_remotes_matched > 1 &&
1511 advice_checkout_ambiguous_remote_branch_name)
1512 advise(_("'%s' matched more than one remote tracking branch.\n"
1513 "We found %d remotes with a reference that matched. So we fell back\n"
1514 "on trying to resolve the argument as a path, but failed there too!\n"
1515 "\n"
1516 "If you meant to check out a remote tracking branch on, e.g. 'origin',\n"
1517 "you can do so by fully qualifying the name with the --track option:\n"
1518 "\n"
1519 " git checkout --track origin/<name>\n"
1520 "\n"
1521 "If you'd like to always have checkouts of an ambiguous <name> prefer\n"
1522 "one remote, e.g. the 'origin' remote, consider setting\n"
1523 "checkout.defaultRemote=origin in your config."),
1524 argv[0],
1525 dwim_remotes_matched);
1526 return ret;
1527 } else {
1528 return checkout_branch(&opts, &new_branch_info);
1529 }
1530 }