Merge branch 'es/worktree-add-cleanup'
[git/git.git] / builtin / checkout.c
1 #include "builtin.h"
2 #include "lockfile.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
23 static const char * const checkout_usage[] = {
24 N_("git checkout [<options>] <branch>"),
25 N_("git checkout [<options>] [<branch>] -- <file>..."),
26 NULL,
27 };
28
29 struct checkout_opts {
30 int patch_mode;
31 int quiet;
32 int merge;
33 int force;
34 int force_detach;
35 int writeout_stage;
36 int overwrite_ignore;
37 int ignore_skipworktree;
38 int ignore_other_worktrees;
39
40 const char *new_branch;
41 const char *new_branch_force;
42 const char *new_orphan_branch;
43 int new_branch_log;
44 enum branch_track track;
45 struct diff_options diff_options;
46
47 int branch_exists;
48 const char *prefix;
49 struct pathspec pathspec;
50 struct tree *source_tree;
51 };
52
53 static int post_checkout_hook(struct commit *old, struct commit *new,
54 int changed)
55 {
56 return run_hook_le(NULL, "post-checkout",
57 sha1_to_hex(old ? old->object.sha1 : null_sha1),
58 sha1_to_hex(new ? new->object.sha1 : null_sha1),
59 changed ? "1" : "0", NULL);
60 /* "new" can be NULL when checking out from the index before
61 a commit exists. */
62
63 }
64
65 static int update_some(const unsigned char *sha1, struct strbuf *base,
66 const char *pathname, unsigned mode, int stage, void *context)
67 {
68 int len;
69 struct cache_entry *ce;
70 int pos;
71
72 if (S_ISDIR(mode))
73 return READ_TREE_RECURSIVE;
74
75 len = base->len + strlen(pathname);
76 ce = xcalloc(1, cache_entry_size(len));
77 hashcpy(ce->sha1, sha1);
78 memcpy(ce->name, base->buf, base->len);
79 memcpy(ce->name + base->len, pathname, len - base->len);
80 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
81 ce->ce_namelen = len;
82 ce->ce_mode = create_ce_mode(mode);
83
84 /*
85 * If the entry is the same as the current index, we can leave the old
86 * entry in place. Whether it is UPTODATE or not, checkout_entry will
87 * do the right thing.
88 */
89 pos = cache_name_pos(ce->name, ce->ce_namelen);
90 if (pos >= 0) {
91 struct cache_entry *old = active_cache[pos];
92 if (ce->ce_mode == old->ce_mode &&
93 !hashcmp(ce->sha1, old->sha1)) {
94 old->ce_flags |= CE_UPDATE;
95 free(ce);
96 return 0;
97 }
98 }
99
100 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
101 return 0;
102 }
103
104 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
105 {
106 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
107
108 /* update the index with the given tree's info
109 * for all args, expanding wildcards, and exit
110 * with any non-zero return code.
111 */
112 return 0;
113 }
114
115 static int skip_same_name(const struct cache_entry *ce, int pos)
116 {
117 while (++pos < active_nr &&
118 !strcmp(active_cache[pos]->name, ce->name))
119 ; /* skip */
120 return pos;
121 }
122
123 static int check_stage(int stage, const struct cache_entry *ce, int pos)
124 {
125 while (pos < active_nr &&
126 !strcmp(active_cache[pos]->name, ce->name)) {
127 if (ce_stage(active_cache[pos]) == stage)
128 return 0;
129 pos++;
130 }
131 if (stage == 2)
132 return error(_("path '%s' does not have our version"), ce->name);
133 else
134 return error(_("path '%s' does not have their version"), ce->name);
135 }
136
137 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
138 {
139 unsigned seen = 0;
140 const char *name = ce->name;
141
142 while (pos < active_nr) {
143 ce = active_cache[pos];
144 if (strcmp(name, ce->name))
145 break;
146 seen |= (1 << ce_stage(ce));
147 pos++;
148 }
149 if ((stages & seen) != stages)
150 return error(_("path '%s' does not have all necessary versions"),
151 name);
152 return 0;
153 }
154
155 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
156 struct checkout *state)
157 {
158 while (pos < active_nr &&
159 !strcmp(active_cache[pos]->name, ce->name)) {
160 if (ce_stage(active_cache[pos]) == stage)
161 return checkout_entry(active_cache[pos], state, NULL);
162 pos++;
163 }
164 if (stage == 2)
165 return error(_("path '%s' does not have our version"), ce->name);
166 else
167 return error(_("path '%s' does not have their version"), ce->name);
168 }
169
170 static int checkout_merged(int pos, struct checkout *state)
171 {
172 struct cache_entry *ce = active_cache[pos];
173 const char *path = ce->name;
174 mmfile_t ancestor, ours, theirs;
175 int status;
176 unsigned char sha1[20];
177 mmbuffer_t result_buf;
178 unsigned char threeway[3][20];
179 unsigned mode = 0;
180
181 memset(threeway, 0, sizeof(threeway));
182 while (pos < active_nr) {
183 int stage;
184 stage = ce_stage(ce);
185 if (!stage || strcmp(path, ce->name))
186 break;
187 hashcpy(threeway[stage - 1], ce->sha1);
188 if (stage == 2)
189 mode = create_ce_mode(ce->ce_mode);
190 pos++;
191 ce = active_cache[pos];
192 }
193 if (is_null_sha1(threeway[1]) || is_null_sha1(threeway[2]))
194 return error(_("path '%s' does not have necessary versions"), path);
195
196 read_mmblob(&ancestor, threeway[0]);
197 read_mmblob(&ours, threeway[1]);
198 read_mmblob(&theirs, threeway[2]);
199
200 /*
201 * NEEDSWORK: re-create conflicts from merges with
202 * merge.renormalize set, too
203 */
204 status = ll_merge(&result_buf, path, &ancestor, "base",
205 &ours, "ours", &theirs, "theirs", NULL);
206 free(ancestor.ptr);
207 free(ours.ptr);
208 free(theirs.ptr);
209 if (status < 0 || !result_buf.ptr) {
210 free(result_buf.ptr);
211 return error(_("path '%s': cannot merge"), path);
212 }
213
214 /*
215 * NEEDSWORK:
216 * There is absolutely no reason to write this as a blob object
217 * and create a phony cache entry just to leak. This hack is
218 * primarily to get to the write_entry() machinery that massages
219 * the contents to work-tree format and writes out which only
220 * allows it for a cache entry. The code in write_entry() needs
221 * to be refactored to allow us to feed a <buffer, size, mode>
222 * instead of a cache entry. Such a refactoring would help
223 * merge_recursive as well (it also writes the merge result to the
224 * object database even when it may contain conflicts).
225 */
226 if (write_sha1_file(result_buf.ptr, result_buf.size,
227 blob_type, sha1))
228 die(_("Unable to add merge result for '%s'"), path);
229 ce = make_cache_entry(mode, sha1, path, 2, 0);
230 if (!ce)
231 die(_("make_cache_entry failed for path '%s'"), path);
232 status = checkout_entry(ce, state, NULL);
233 return status;
234 }
235
236 static int checkout_paths(const struct checkout_opts *opts,
237 const char *revision)
238 {
239 int pos;
240 struct checkout state;
241 static char *ps_matched;
242 unsigned char rev[20];
243 int flag;
244 struct commit *head;
245 int errs = 0;
246 struct lock_file *lock_file;
247
248 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
249 die(_("'%s' cannot be used with updating paths"), "--track");
250
251 if (opts->new_branch_log)
252 die(_("'%s' cannot be used with updating paths"), "-l");
253
254 if (opts->force && opts->patch_mode)
255 die(_("'%s' cannot be used with updating paths"), "-f");
256
257 if (opts->force_detach)
258 die(_("'%s' cannot be used with updating paths"), "--detach");
259
260 if (opts->merge && opts->patch_mode)
261 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
262
263 if (opts->force && opts->merge)
264 die(_("'%s' cannot be used with %s"), "-f", "-m");
265
266 if (opts->new_branch)
267 die(_("Cannot update paths and switch to branch '%s' at the same time."),
268 opts->new_branch);
269
270 if (opts->patch_mode)
271 return run_add_interactive(revision, "--patch=checkout",
272 &opts->pathspec);
273
274 lock_file = xcalloc(1, sizeof(struct lock_file));
275
276 hold_locked_index(lock_file, 1);
277 if (read_cache_preload(&opts->pathspec) < 0)
278 return error(_("corrupt index file"));
279
280 if (opts->source_tree)
281 read_tree_some(opts->source_tree, &opts->pathspec);
282
283 ps_matched = xcalloc(1, opts->pathspec.nr);
284
285 /*
286 * Make sure all pathspecs participated in locating the paths
287 * to be checked out.
288 */
289 for (pos = 0; pos < active_nr; pos++) {
290 struct cache_entry *ce = active_cache[pos];
291 ce->ce_flags &= ~CE_MATCHED;
292 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
293 continue;
294 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
295 /*
296 * "git checkout tree-ish -- path", but this entry
297 * is in the original index; it will not be checked
298 * out to the working tree and it does not matter
299 * if pathspec matched this entry. We will not do
300 * anything to this entry at all.
301 */
302 continue;
303 /*
304 * Either this entry came from the tree-ish we are
305 * checking the paths out of, or we are checking out
306 * of the index.
307 *
308 * If it comes from the tree-ish, we already know it
309 * matches the pathspec and could just stamp
310 * CE_MATCHED to it from update_some(). But we still
311 * need ps_matched and read_tree_recursive (and
312 * eventually tree_entry_interesting) cannot fill
313 * ps_matched yet. Once it can, we can avoid calling
314 * match_pathspec() for _all_ entries when
315 * opts->source_tree != NULL.
316 */
317 if (ce_path_match(ce, &opts->pathspec, ps_matched))
318 ce->ce_flags |= CE_MATCHED;
319 }
320
321 if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
322 free(ps_matched);
323 return 1;
324 }
325 free(ps_matched);
326
327 /* "checkout -m path" to recreate conflicted state */
328 if (opts->merge)
329 unmerge_marked_index(&the_index);
330
331 /* Any unmerged paths? */
332 for (pos = 0; pos < active_nr; pos++) {
333 const struct cache_entry *ce = active_cache[pos];
334 if (ce->ce_flags & CE_MATCHED) {
335 if (!ce_stage(ce))
336 continue;
337 if (opts->force) {
338 warning(_("path '%s' is unmerged"), ce->name);
339 } else if (opts->writeout_stage) {
340 errs |= check_stage(opts->writeout_stage, ce, pos);
341 } else if (opts->merge) {
342 errs |= check_stages((1<<2) | (1<<3), ce, pos);
343 } else {
344 errs = 1;
345 error(_("path '%s' is unmerged"), ce->name);
346 }
347 pos = skip_same_name(ce, pos) - 1;
348 }
349 }
350 if (errs)
351 return 1;
352
353 /* Now we are committed to check them out */
354 memset(&state, 0, sizeof(state));
355 state.force = 1;
356 state.refresh_cache = 1;
357 state.istate = &the_index;
358 for (pos = 0; pos < active_nr; pos++) {
359 struct cache_entry *ce = active_cache[pos];
360 if (ce->ce_flags & CE_MATCHED) {
361 if (!ce_stage(ce)) {
362 errs |= checkout_entry(ce, &state, NULL);
363 continue;
364 }
365 if (opts->writeout_stage)
366 errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
367 else if (opts->merge)
368 errs |= checkout_merged(pos, &state);
369 pos = skip_same_name(ce, pos) - 1;
370 }
371 }
372
373 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
374 die(_("unable to write new index file"));
375
376 read_ref_full("HEAD", 0, rev, &flag);
377 head = lookup_commit_reference_gently(rev, 1);
378
379 errs |= post_checkout_hook(head, head, 0);
380 return errs;
381 }
382
383 static void show_local_changes(struct object *head,
384 const struct diff_options *opts)
385 {
386 struct rev_info rev;
387 /* I think we want full paths, even if we're in a subdirectory. */
388 init_revisions(&rev, NULL);
389 rev.diffopt.flags = opts->flags;
390 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
391 diff_setup_done(&rev.diffopt);
392 add_pending_object(&rev, head, NULL);
393 run_diff_index(&rev, 0);
394 }
395
396 static void describe_detached_head(const char *msg, struct commit *commit)
397 {
398 struct strbuf sb = STRBUF_INIT;
399 if (!parse_commit(commit))
400 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
401 fprintf(stderr, "%s %s... %s\n", msg,
402 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
403 strbuf_release(&sb);
404 }
405
406 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
407 int worktree, int *writeout_error)
408 {
409 struct unpack_trees_options opts;
410 struct tree_desc tree_desc;
411
412 memset(&opts, 0, sizeof(opts));
413 opts.head_idx = -1;
414 opts.update = worktree;
415 opts.skip_unmerged = !worktree;
416 opts.reset = 1;
417 opts.merge = 1;
418 opts.fn = oneway_merge;
419 opts.verbose_update = !o->quiet && isatty(2);
420 opts.src_index = &the_index;
421 opts.dst_index = &the_index;
422 parse_tree(tree);
423 init_tree_desc(&tree_desc, tree->buffer, tree->size);
424 switch (unpack_trees(1, &tree_desc, &opts)) {
425 case -2:
426 *writeout_error = 1;
427 /*
428 * We return 0 nevertheless, as the index is all right
429 * and more importantly we have made best efforts to
430 * update paths in the work tree, and we cannot revert
431 * them.
432 */
433 case 0:
434 return 0;
435 default:
436 return 128;
437 }
438 }
439
440 struct branch_info {
441 const char *name; /* The short name used */
442 const char *path; /* The full name of a real branch */
443 struct commit *commit; /* The named commit */
444 /*
445 * if not null the branch is detached because it's already
446 * checked out in this checkout
447 */
448 char *checkout;
449 };
450
451 static void setup_branch_path(struct branch_info *branch)
452 {
453 struct strbuf buf = STRBUF_INIT;
454
455 strbuf_branchname(&buf, branch->name);
456 if (strcmp(buf.buf, branch->name))
457 branch->name = xstrdup(buf.buf);
458 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
459 branch->path = strbuf_detach(&buf, NULL);
460 }
461
462 static int merge_working_tree(const struct checkout_opts *opts,
463 struct branch_info *old,
464 struct branch_info *new,
465 int *writeout_error)
466 {
467 int ret;
468 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
469
470 hold_locked_index(lock_file, 1);
471 if (read_cache_preload(NULL) < 0)
472 return error(_("corrupt index file"));
473
474 resolve_undo_clear();
475 if (opts->force) {
476 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
477 if (ret)
478 return ret;
479 } else {
480 struct tree_desc trees[2];
481 struct tree *tree;
482 struct unpack_trees_options topts;
483
484 memset(&topts, 0, sizeof(topts));
485 topts.head_idx = -1;
486 topts.src_index = &the_index;
487 topts.dst_index = &the_index;
488
489 setup_unpack_trees_porcelain(&topts, "checkout");
490
491 refresh_cache(REFRESH_QUIET);
492
493 if (unmerged_cache()) {
494 error(_("you need to resolve your current index first"));
495 return 1;
496 }
497
498 /* 2-way merge to the new branch */
499 topts.initial_checkout = is_cache_unborn();
500 topts.update = 1;
501 topts.merge = 1;
502 topts.gently = opts->merge && old->commit;
503 topts.verbose_update = !opts->quiet && isatty(2);
504 topts.fn = twoway_merge;
505 if (opts->overwrite_ignore) {
506 topts.dir = xcalloc(1, sizeof(*topts.dir));
507 topts.dir->flags |= DIR_SHOW_IGNORED;
508 setup_standard_excludes(topts.dir);
509 }
510 tree = parse_tree_indirect(old->commit ?
511 old->commit->object.sha1 :
512 EMPTY_TREE_SHA1_BIN);
513 init_tree_desc(&trees[0], tree->buffer, tree->size);
514 tree = parse_tree_indirect(new->commit->object.sha1);
515 init_tree_desc(&trees[1], tree->buffer, tree->size);
516
517 ret = unpack_trees(2, trees, &topts);
518 if (ret == -1) {
519 /*
520 * Unpack couldn't do a trivial merge; either
521 * give up or do a real merge, depending on
522 * whether the merge flag was used.
523 */
524 struct tree *result;
525 struct tree *work;
526 struct merge_options o;
527 if (!opts->merge)
528 return 1;
529
530 /*
531 * Without old->commit, the below is the same as
532 * the two-tree unpack we already tried and failed.
533 */
534 if (!old->commit)
535 return 1;
536
537 /* Do more real merge */
538
539 /*
540 * We update the index fully, then write the
541 * tree from the index, then merge the new
542 * branch with the current tree, with the old
543 * branch as the base. Then we reset the index
544 * (but not the working tree) to the new
545 * branch, leaving the working tree as the
546 * merged version, but skipping unmerged
547 * entries in the index.
548 */
549
550 add_files_to_cache(NULL, NULL, 0);
551 /*
552 * NEEDSWORK: carrying over local changes
553 * when branches have different end-of-line
554 * normalization (or clean+smudge rules) is
555 * a pain; plumb in an option to set
556 * o.renormalize?
557 */
558 init_merge_options(&o);
559 o.verbosity = 0;
560 work = write_tree_from_memory(&o);
561
562 ret = reset_tree(new->commit->tree, opts, 1,
563 writeout_error);
564 if (ret)
565 return ret;
566 o.ancestor = old->name;
567 o.branch1 = new->name;
568 o.branch2 = "local";
569 merge_trees(&o, new->commit->tree, work,
570 old->commit->tree, &result);
571 ret = reset_tree(new->commit->tree, opts, 0,
572 writeout_error);
573 if (ret)
574 return ret;
575 }
576 }
577
578 if (!active_cache_tree)
579 active_cache_tree = cache_tree();
580
581 if (!cache_tree_fully_valid(active_cache_tree))
582 cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
583
584 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
585 die(_("unable to write new index file"));
586
587 if (!opts->force && !opts->quiet)
588 show_local_changes(&new->commit->object, &opts->diff_options);
589
590 return 0;
591 }
592
593 static void report_tracking(struct branch_info *new)
594 {
595 struct strbuf sb = STRBUF_INIT;
596 struct branch *branch = branch_get(new->name);
597
598 if (!format_tracking_info(branch, &sb))
599 return;
600 fputs(sb.buf, stdout);
601 strbuf_release(&sb);
602 }
603
604 static void update_refs_for_switch(const struct checkout_opts *opts,
605 struct branch_info *old,
606 struct branch_info *new)
607 {
608 struct strbuf msg = STRBUF_INIT;
609 const char *old_desc, *reflog_msg;
610 if (opts->new_branch) {
611 if (opts->new_orphan_branch) {
612 if (opts->new_branch_log && !log_all_ref_updates) {
613 int ret;
614 char *refname;
615 struct strbuf err = STRBUF_INIT;
616
617 refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
618 ret = safe_create_reflog(refname, 1, &err);
619 free(refname);
620 if (ret) {
621 fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
622 opts->new_orphan_branch, err.buf);
623 strbuf_release(&err);
624 return;
625 }
626 strbuf_release(&err);
627 }
628 }
629 else
630 create_branch(old->name, opts->new_branch, new->name,
631 opts->new_branch_force ? 1 : 0,
632 opts->new_branch_log,
633 opts->new_branch_force ? 1 : 0,
634 opts->quiet,
635 opts->track);
636 new->name = opts->new_branch;
637 setup_branch_path(new);
638 }
639
640 old_desc = old->name;
641 if (!old_desc && old->commit)
642 old_desc = sha1_to_hex(old->commit->object.sha1);
643
644 reflog_msg = getenv("GIT_REFLOG_ACTION");
645 if (!reflog_msg)
646 strbuf_addf(&msg, "checkout: moving from %s to %s",
647 old_desc ? old_desc : "(invalid)", new->name);
648 else
649 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
650
651 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
652 /* Nothing to do. */
653 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
654 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
655 REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
656 if (!opts->quiet) {
657 if (old->path && advice_detached_head)
658 detach_advice(new->name);
659 describe_detached_head(_("HEAD is now at"), new->commit);
660 }
661 } else if (new->path) { /* Switch branches. */
662 create_symref("HEAD", new->path, msg.buf);
663 if (!opts->quiet) {
664 if (old->path && !strcmp(new->path, old->path)) {
665 if (opts->new_branch_force)
666 fprintf(stderr, _("Reset branch '%s'\n"),
667 new->name);
668 else
669 fprintf(stderr, _("Already on '%s'\n"),
670 new->name);
671 } else if (opts->new_branch) {
672 if (opts->branch_exists)
673 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
674 else
675 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
676 } else {
677 fprintf(stderr, _("Switched to branch '%s'\n"),
678 new->name);
679 }
680 }
681 if (old->path && old->name) {
682 if (!ref_exists(old->path) && reflog_exists(old->path))
683 delete_reflog(old->path);
684 }
685 }
686 remove_branch_state();
687 strbuf_release(&msg);
688 if (!opts->quiet &&
689 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
690 report_tracking(new);
691 }
692
693 static int add_pending_uninteresting_ref(const char *refname,
694 const struct object_id *oid,
695 int flags, void *cb_data)
696 {
697 add_pending_sha1(cb_data, refname, oid->hash, UNINTERESTING);
698 return 0;
699 }
700
701 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
702 {
703 strbuf_addstr(sb, " ");
704 strbuf_addstr(sb,
705 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
706 strbuf_addch(sb, ' ');
707 if (!parse_commit(commit))
708 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
709 strbuf_addch(sb, '\n');
710 }
711
712 #define ORPHAN_CUTOFF 4
713 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
714 {
715 struct commit *c, *last = NULL;
716 struct strbuf sb = STRBUF_INIT;
717 int lost = 0;
718 while ((c = get_revision(revs)) != NULL) {
719 if (lost < ORPHAN_CUTOFF)
720 describe_one_orphan(&sb, c);
721 last = c;
722 lost++;
723 }
724 if (ORPHAN_CUTOFF < lost) {
725 int more = lost - ORPHAN_CUTOFF;
726 if (more == 1)
727 describe_one_orphan(&sb, last);
728 else
729 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
730 }
731
732 fprintf(stderr,
733 Q_(
734 /* The singular version */
735 "Warning: you are leaving %d commit behind, "
736 "not connected to\n"
737 "any of your branches:\n\n"
738 "%s\n",
739 /* The plural version */
740 "Warning: you are leaving %d commits behind, "
741 "not connected to\n"
742 "any of your branches:\n\n"
743 "%s\n",
744 /* Give ngettext() the count */
745 lost),
746 lost,
747 sb.buf);
748 strbuf_release(&sb);
749
750 if (advice_detached_head)
751 fprintf(stderr,
752 Q_(
753 /* The singular version */
754 "If you want to keep it by creating a new branch, "
755 "this may be a good time\nto do so with:\n\n"
756 " git branch <new-branch-name> %s\n\n",
757 /* The plural version */
758 "If you want to keep them by creating a new branch, "
759 "this may be a good time\nto do so with:\n\n"
760 " git branch <new-branch-name> %s\n\n",
761 /* Give ngettext() the count */
762 lost),
763 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
764 }
765
766 /*
767 * We are about to leave commit that was at the tip of a detached
768 * HEAD. If it is not reachable from any ref, this is the last chance
769 * for the user to do so without resorting to reflog.
770 */
771 static void orphaned_commit_warning(struct commit *old, struct commit *new)
772 {
773 struct rev_info revs;
774 struct object *object = &old->object;
775 struct object_array refs;
776
777 init_revisions(&revs, NULL);
778 setup_revisions(0, NULL, &revs, NULL);
779
780 object->flags &= ~UNINTERESTING;
781 add_pending_object(&revs, object, sha1_to_hex(object->sha1));
782
783 for_each_ref(add_pending_uninteresting_ref, &revs);
784 add_pending_sha1(&revs, "HEAD", new->object.sha1, UNINTERESTING);
785
786 refs = revs.pending;
787 revs.leak_pending = 1;
788
789 if (prepare_revision_walk(&revs))
790 die(_("internal error in revision walk"));
791 if (!(old->object.flags & UNINTERESTING))
792 suggest_reattach(old, &revs);
793 else
794 describe_detached_head(_("Previous HEAD position was"), old);
795
796 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
797 free(refs.objects);
798 }
799
800 static int switch_branches(const struct checkout_opts *opts,
801 struct branch_info *new)
802 {
803 int ret = 0;
804 struct branch_info old;
805 void *path_to_free;
806 unsigned char rev[20];
807 int flag, writeout_error = 0;
808 memset(&old, 0, sizeof(old));
809 old.path = path_to_free = resolve_refdup("HEAD", 0, rev, &flag);
810 old.commit = lookup_commit_reference_gently(rev, 1);
811 if (!(flag & REF_ISSYMREF))
812 old.path = NULL;
813
814 if (old.path)
815 skip_prefix(old.path, "refs/heads/", &old.name);
816
817 if (!new->name) {
818 new->name = "HEAD";
819 new->commit = old.commit;
820 if (!new->commit)
821 die(_("You are on a branch yet to be born"));
822 parse_commit_or_die(new->commit);
823 }
824
825 ret = merge_working_tree(opts, &old, new, &writeout_error);
826 if (ret) {
827 free(path_to_free);
828 return ret;
829 }
830
831 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
832 orphaned_commit_warning(old.commit, new->commit);
833
834 update_refs_for_switch(opts, &old, new);
835
836 ret = post_checkout_hook(old.commit, new->commit, 1);
837 free(path_to_free);
838 return ret || writeout_error;
839 }
840
841 static int git_checkout_config(const char *var, const char *value, void *cb)
842 {
843 if (!strcmp(var, "diff.ignoresubmodules")) {
844 struct checkout_opts *opts = cb;
845 handle_ignore_submodules_arg(&opts->diff_options, value);
846 return 0;
847 }
848
849 if (starts_with(var, "submodule."))
850 return parse_submodule_config_option(var, value);
851
852 return git_xmerge_config(var, value, NULL);
853 }
854
855 struct tracking_name_data {
856 /* const */ char *src_ref;
857 char *dst_ref;
858 unsigned char *dst_sha1;
859 int unique;
860 };
861
862 static int check_tracking_name(struct remote *remote, void *cb_data)
863 {
864 struct tracking_name_data *cb = cb_data;
865 struct refspec query;
866 memset(&query, 0, sizeof(struct refspec));
867 query.src = cb->src_ref;
868 if (remote_find_tracking(remote, &query) ||
869 get_sha1(query.dst, cb->dst_sha1)) {
870 free(query.dst);
871 return 0;
872 }
873 if (cb->dst_ref) {
874 free(query.dst);
875 cb->unique = 0;
876 return 0;
877 }
878 cb->dst_ref = query.dst;
879 return 0;
880 }
881
882 static const char *unique_tracking_name(const char *name, unsigned char *sha1)
883 {
884 struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
885 char src_ref[PATH_MAX];
886 snprintf(src_ref, PATH_MAX, "refs/heads/%s", name);
887 cb_data.src_ref = src_ref;
888 cb_data.dst_sha1 = sha1;
889 for_each_remote(check_tracking_name, &cb_data);
890 if (cb_data.unique)
891 return cb_data.dst_ref;
892 free(cb_data.dst_ref);
893 return NULL;
894 }
895
896 static int parse_branchname_arg(int argc, const char **argv,
897 int dwim_new_local_branch_ok,
898 struct branch_info *new,
899 struct checkout_opts *opts,
900 unsigned char rev[20])
901 {
902 struct tree **source_tree = &opts->source_tree;
903 const char **new_branch = &opts->new_branch;
904 int argcount = 0;
905 unsigned char branch_rev[20];
906 const char *arg;
907 int dash_dash_pos;
908 int has_dash_dash = 0;
909 int i;
910
911 /*
912 * case 1: git checkout <ref> -- [<paths>]
913 *
914 * <ref> must be a valid tree, everything after the '--' must be
915 * a path.
916 *
917 * case 2: git checkout -- [<paths>]
918 *
919 * everything after the '--' must be paths.
920 *
921 * case 3: git checkout <something> [--]
922 *
923 * (a) If <something> is a commit, that is to
924 * switch to the branch or detach HEAD at it. As a special case,
925 * if <something> is A...B (missing A or B means HEAD but you can
926 * omit at most one side), and if there is a unique merge base
927 * between A and B, A...B names that merge base.
928 *
929 * (b) If <something> is _not_ a commit, either "--" is present
930 * or <something> is not a path, no -t or -b was given, and
931 * and there is a tracking branch whose name is <something>
932 * in one and only one remote, then this is a short-hand to
933 * fork local <something> from that remote-tracking branch.
934 *
935 * (c) Otherwise, if "--" is present, treat it like case (1).
936 *
937 * (d) Otherwise :
938 * - if it's a reference, treat it like case (1)
939 * - else if it's a path, treat it like case (2)
940 * - else: fail.
941 *
942 * case 4: git checkout <something> <paths>
943 *
944 * The first argument must not be ambiguous.
945 * - If it's *only* a reference, treat it like case (1).
946 * - If it's only a path, treat it like case (2).
947 * - else: fail.
948 *
949 */
950 if (!argc)
951 return 0;
952
953 arg = argv[0];
954 dash_dash_pos = -1;
955 for (i = 0; i < argc; i++) {
956 if (!strcmp(argv[i], "--")) {
957 dash_dash_pos = i;
958 break;
959 }
960 }
961 if (dash_dash_pos == 0)
962 return 1; /* case (2) */
963 else if (dash_dash_pos == 1)
964 has_dash_dash = 1; /* case (3) or (1) */
965 else if (dash_dash_pos >= 2)
966 die(_("only one reference expected, %d given."), dash_dash_pos);
967
968 if (!strcmp(arg, "-"))
969 arg = "@{-1}";
970
971 if (get_sha1_mb(arg, rev)) {
972 /*
973 * Either case (3) or (4), with <something> not being
974 * a commit, or an attempt to use case (1) with an
975 * invalid ref.
976 *
977 * It's likely an error, but we need to find out if
978 * we should auto-create the branch, case (3).(b).
979 */
980 int recover_with_dwim = dwim_new_local_branch_ok;
981
982 if (check_filename(NULL, arg) && !has_dash_dash)
983 recover_with_dwim = 0;
984 /*
985 * Accept "git checkout foo" and "git checkout foo --"
986 * as candidates for dwim.
987 */
988 if (!(argc == 1 && !has_dash_dash) &&
989 !(argc == 2 && has_dash_dash))
990 recover_with_dwim = 0;
991
992 if (recover_with_dwim) {
993 const char *remote = unique_tracking_name(arg, rev);
994 if (remote) {
995 *new_branch = arg;
996 arg = remote;
997 /* DWIMmed to create local branch, case (3).(b) */
998 } else {
999 recover_with_dwim = 0;
1000 }
1001 }
1002
1003 if (!recover_with_dwim) {
1004 if (has_dash_dash)
1005 die(_("invalid reference: %s"), arg);
1006 return argcount;
1007 }
1008 }
1009
1010 /* we can't end up being in (2) anymore, eat the argument */
1011 argcount++;
1012 argv++;
1013 argc--;
1014
1015 new->name = arg;
1016 setup_branch_path(new);
1017
1018 if (!check_refname_format(new->path, 0) &&
1019 !read_ref(new->path, branch_rev))
1020 hashcpy(rev, branch_rev);
1021 else
1022 new->path = NULL; /* not an existing branch */
1023
1024 new->commit = lookup_commit_reference_gently(rev, 1);
1025 if (!new->commit) {
1026 /* not a commit */
1027 *source_tree = parse_tree_indirect(rev);
1028 } else {
1029 parse_commit_or_die(new->commit);
1030 *source_tree = new->commit->tree;
1031 }
1032
1033 if (!*source_tree) /* case (1): want a tree */
1034 die(_("reference is not a tree: %s"), arg);
1035 if (!has_dash_dash) {/* case (3).(d) -> (1) */
1036 /*
1037 * Do not complain the most common case
1038 * git checkout branch
1039 * even if there happen to be a file called 'branch';
1040 * it would be extremely annoying.
1041 */
1042 if (argc)
1043 verify_non_filename(NULL, arg);
1044 } else {
1045 argcount++;
1046 argv++;
1047 argc--;
1048 }
1049
1050 return argcount;
1051 }
1052
1053 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1054 {
1055 int status;
1056 struct strbuf branch_ref = STRBUF_INIT;
1057
1058 if (!opts->new_branch)
1059 die(_("You are on a branch yet to be born"));
1060 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1061 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1062 strbuf_release(&branch_ref);
1063 if (!opts->quiet)
1064 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1065 opts->new_branch);
1066 return status;
1067 }
1068
1069 static int checkout_branch(struct checkout_opts *opts,
1070 struct branch_info *new)
1071 {
1072 if (opts->pathspec.nr)
1073 die(_("paths cannot be used with switching branches"));
1074
1075 if (opts->patch_mode)
1076 die(_("'%s' cannot be used with switching branches"),
1077 "--patch");
1078
1079 if (opts->writeout_stage)
1080 die(_("'%s' cannot be used with switching branches"),
1081 "--ours/--theirs");
1082
1083 if (opts->force && opts->merge)
1084 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1085
1086 if (opts->force_detach && opts->new_branch)
1087 die(_("'%s' cannot be used with '%s'"),
1088 "--detach", "-b/-B/--orphan");
1089
1090 if (opts->new_orphan_branch) {
1091 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1092 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1093 } else if (opts->force_detach) {
1094 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1095 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1096 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1097 opts->track = git_branch_track;
1098
1099 if (new->name && !new->commit)
1100 die(_("Cannot switch branch to a non-commit '%s'"),
1101 new->name);
1102
1103 if (new->path && !opts->force_detach && !opts->new_branch &&
1104 !opts->ignore_other_worktrees) {
1105 unsigned char sha1[20];
1106 int flag;
1107 char *head_ref = resolve_refdup("HEAD", 0, sha1, &flag);
1108 if (head_ref &&
1109 (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)))
1110 die_if_checked_out(new->path);
1111 free(head_ref);
1112 }
1113
1114 if (!new->commit && opts->new_branch) {
1115 unsigned char rev[20];
1116 int flag;
1117
1118 if (!read_ref_full("HEAD", 0, rev, &flag) &&
1119 (flag & REF_ISSYMREF) && is_null_sha1(rev))
1120 return switch_unborn_to_new_branch(opts);
1121 }
1122 return switch_branches(opts, new);
1123 }
1124
1125 int cmd_checkout(int argc, const char **argv, const char *prefix)
1126 {
1127 struct checkout_opts opts;
1128 struct branch_info new;
1129 char *conflict_style = NULL;
1130 int dwim_new_local_branch = 1;
1131 struct option options[] = {
1132 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1133 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1134 N_("create and checkout a new branch")),
1135 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1136 N_("create/reset and checkout a branch")),
1137 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1138 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach the HEAD at named commit")),
1139 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1140 BRANCH_TRACK_EXPLICIT),
1141 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1142 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1143 2),
1144 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1145 3),
1146 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1147 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1148 OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1149 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1150 N_("conflict style (merge or diff3)")),
1151 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1152 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1153 N_("do not limit pathspecs to sparse entries only")),
1154 OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1155 N_("second guess 'git checkout <no-such-branch>'")),
1156 OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1157 N_("do not check if another worktree is holding the given ref")),
1158 OPT_END(),
1159 };
1160
1161 memset(&opts, 0, sizeof(opts));
1162 memset(&new, 0, sizeof(new));
1163 opts.overwrite_ignore = 1;
1164 opts.prefix = prefix;
1165
1166 gitmodules_config();
1167 git_config(git_checkout_config, &opts);
1168
1169 opts.track = BRANCH_TRACK_UNSPECIFIED;
1170
1171 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1172 PARSE_OPT_KEEP_DASHDASH);
1173
1174 if (conflict_style) {
1175 opts.merge = 1; /* implied */
1176 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1177 }
1178
1179 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1180 die(_("-b, -B and --orphan are mutually exclusive"));
1181
1182 /*
1183 * From here on, new_branch will contain the branch to be checked out,
1184 * and new_branch_force and new_orphan_branch will tell us which one of
1185 * -b/-B/--orphan is being used.
1186 */
1187 if (opts.new_branch_force)
1188 opts.new_branch = opts.new_branch_force;
1189
1190 if (opts.new_orphan_branch)
1191 opts.new_branch = opts.new_orphan_branch;
1192
1193 /* --track without -b/-B/--orphan should DWIM */
1194 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1195 const char *argv0 = argv[0];
1196 if (!argc || !strcmp(argv0, "--"))
1197 die (_("--track needs a branch name"));
1198 skip_prefix(argv0, "refs/", &argv0);
1199 skip_prefix(argv0, "remotes/", &argv0);
1200 argv0 = strchr(argv0, '/');
1201 if (!argv0 || !argv0[1])
1202 die (_("Missing branch name; try -b"));
1203 opts.new_branch = argv0 + 1;
1204 }
1205
1206 /*
1207 * Extract branch name from command line arguments, so
1208 * all that is left is pathspecs.
1209 *
1210 * Handle
1211 *
1212 * 1) git checkout <tree> -- [<paths>]
1213 * 2) git checkout -- [<paths>]
1214 * 3) git checkout <something> [<paths>]
1215 *
1216 * including "last branch" syntax and DWIM-ery for names of
1217 * remote branches, erroring out for invalid or ambiguous cases.
1218 */
1219 if (argc) {
1220 unsigned char rev[20];
1221 int dwim_ok =
1222 !opts.patch_mode &&
1223 dwim_new_local_branch &&
1224 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1225 !opts.new_branch;
1226 int n = parse_branchname_arg(argc, argv, dwim_ok,
1227 &new, &opts, rev);
1228 argv += n;
1229 argc -= n;
1230 }
1231
1232 if (argc) {
1233 parse_pathspec(&opts.pathspec, 0,
1234 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1235 prefix, argv);
1236
1237 if (!opts.pathspec.nr)
1238 die(_("invalid path specification"));
1239
1240 /*
1241 * Try to give more helpful suggestion.
1242 * new_branch && argc > 1 will be caught later.
1243 */
1244 if (opts.new_branch && argc == 1)
1245 die(_("Cannot update paths and switch to branch '%s' at the same time.\n"
1246 "Did you intend to checkout '%s' which can not be resolved as commit?"),
1247 opts.new_branch, argv[0]);
1248
1249 if (opts.force_detach)
1250 die(_("git checkout: --detach does not take a path argument '%s'"),
1251 argv[0]);
1252
1253 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1254 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1255 "checking out of the index."));
1256 }
1257
1258 if (opts.new_branch) {
1259 struct strbuf buf = STRBUF_INIT;
1260
1261 opts.branch_exists =
1262 validate_new_branchname(opts.new_branch, &buf,
1263 !!opts.new_branch_force,
1264 !!opts.new_branch_force);
1265
1266 strbuf_release(&buf);
1267 }
1268
1269 if (opts.patch_mode || opts.pathspec.nr)
1270 return checkout_paths(&opts, new.name);
1271 else
1272 return checkout_branch(&opts, &new);
1273 }