bfa5419f335dc1db98059869de24f152cffb9aa6
[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-config.h"
22 #include "submodule.h"
23
24 static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
25
26 static const char * const checkout_usage[] = {
27 N_("git checkout [<options>] <branch>"),
28 N_("git checkout [<options>] [<branch>] -- <file>..."),
29 NULL,
30 };
31
32 static int option_parse_recurse_submodules(const struct option *opt,
33 const char *arg, int unset)
34 {
35 if (unset) {
36 recurse_submodules = RECURSE_SUBMODULES_OFF;
37 return 0;
38 }
39 if (arg)
40 recurse_submodules =
41 parse_update_recurse_submodules_arg(opt->long_name,
42 arg);
43 else
44 recurse_submodules = RECURSE_SUBMODULES_ON;
45
46 return 0;
47 }
48
49 struct checkout_opts {
50 int patch_mode;
51 int quiet;
52 int merge;
53 int force;
54 int force_detach;
55 int writeout_stage;
56 int overwrite_ignore;
57 int ignore_skipworktree;
58 int ignore_other_worktrees;
59 int show_progress;
60
61 const char *new_branch;
62 const char *new_branch_force;
63 const char *new_orphan_branch;
64 int new_branch_log;
65 enum branch_track track;
66 struct diff_options diff_options;
67
68 int branch_exists;
69 const char *prefix;
70 struct pathspec pathspec;
71 struct tree *source_tree;
72 };
73
74 static int post_checkout_hook(struct commit *old, struct commit *new,
75 int changed)
76 {
77 return run_hook_le(NULL, "post-checkout",
78 oid_to_hex(old ? &old->object.oid : &null_oid),
79 oid_to_hex(new ? &new->object.oid : &null_oid),
80 changed ? "1" : "0", NULL);
81 /* "new" can be NULL when checking out from the index before
82 a commit exists. */
83
84 }
85
86 static int update_some(const unsigned char *sha1, struct strbuf *base,
87 const char *pathname, unsigned mode, int stage, void *context)
88 {
89 int len;
90 struct cache_entry *ce;
91 int pos;
92
93 if (S_ISDIR(mode))
94 return READ_TREE_RECURSIVE;
95
96 len = base->len + strlen(pathname);
97 ce = xcalloc(1, cache_entry_size(len));
98 hashcpy(ce->oid.hash, sha1);
99 memcpy(ce->name, base->buf, base->len);
100 memcpy(ce->name + base->len, pathname, len - base->len);
101 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
102 ce->ce_namelen = len;
103 ce->ce_mode = create_ce_mode(mode);
104
105 /*
106 * If the entry is the same as the current index, we can leave the old
107 * entry in place. Whether it is UPTODATE or not, checkout_entry will
108 * do the right thing.
109 */
110 pos = cache_name_pos(ce->name, ce->ce_namelen);
111 if (pos >= 0) {
112 struct cache_entry *old = active_cache[pos];
113 if (ce->ce_mode == old->ce_mode &&
114 !oidcmp(&ce->oid, &old->oid)) {
115 old->ce_flags |= CE_UPDATE;
116 free(ce);
117 return 0;
118 }
119 }
120
121 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
122 return 0;
123 }
124
125 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
126 {
127 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
128
129 /* update the index with the given tree's info
130 * for all args, expanding wildcards, and exit
131 * with any non-zero return code.
132 */
133 return 0;
134 }
135
136 static int skip_same_name(const struct cache_entry *ce, int pos)
137 {
138 while (++pos < active_nr &&
139 !strcmp(active_cache[pos]->name, ce->name))
140 ; /* skip */
141 return pos;
142 }
143
144 static int check_stage(int stage, const struct cache_entry *ce, int pos)
145 {
146 while (pos < active_nr &&
147 !strcmp(active_cache[pos]->name, ce->name)) {
148 if (ce_stage(active_cache[pos]) == stage)
149 return 0;
150 pos++;
151 }
152 if (stage == 2)
153 return error(_("path '%s' does not have our version"), ce->name);
154 else
155 return error(_("path '%s' does not have their version"), ce->name);
156 }
157
158 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
159 {
160 unsigned seen = 0;
161 const char *name = ce->name;
162
163 while (pos < active_nr) {
164 ce = active_cache[pos];
165 if (strcmp(name, ce->name))
166 break;
167 seen |= (1 << ce_stage(ce));
168 pos++;
169 }
170 if ((stages & seen) != stages)
171 return error(_("path '%s' does not have all necessary versions"),
172 name);
173 return 0;
174 }
175
176 static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
177 const struct checkout *state)
178 {
179 while (pos < active_nr &&
180 !strcmp(active_cache[pos]->name, ce->name)) {
181 if (ce_stage(active_cache[pos]) == stage)
182 return checkout_entry(active_cache[pos], state, NULL);
183 pos++;
184 }
185 if (stage == 2)
186 return error(_("path '%s' does not have our version"), ce->name);
187 else
188 return error(_("path '%s' does not have their version"), ce->name);
189 }
190
191 static int checkout_merged(int pos, const struct checkout *state)
192 {
193 struct cache_entry *ce = active_cache[pos];
194 const char *path = ce->name;
195 mmfile_t ancestor, ours, theirs;
196 int status;
197 struct object_id oid;
198 mmbuffer_t result_buf;
199 struct object_id threeway[3];
200 unsigned mode = 0;
201
202 memset(threeway, 0, sizeof(threeway));
203 while (pos < active_nr) {
204 int stage;
205 stage = ce_stage(ce);
206 if (!stage || strcmp(path, ce->name))
207 break;
208 oidcpy(&threeway[stage - 1], &ce->oid);
209 if (stage == 2)
210 mode = create_ce_mode(ce->ce_mode);
211 pos++;
212 ce = active_cache[pos];
213 }
214 if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
215 return error(_("path '%s' does not have necessary versions"), path);
216
217 read_mmblob(&ancestor, &threeway[0]);
218 read_mmblob(&ours, &threeway[1]);
219 read_mmblob(&theirs, &threeway[2]);
220
221 /*
222 * NEEDSWORK: re-create conflicts from merges with
223 * merge.renormalize set, too
224 */
225 status = ll_merge(&result_buf, path, &ancestor, "base",
226 &ours, "ours", &theirs, "theirs", NULL);
227 free(ancestor.ptr);
228 free(ours.ptr);
229 free(theirs.ptr);
230 if (status < 0 || !result_buf.ptr) {
231 free(result_buf.ptr);
232 return error(_("path '%s': cannot merge"), path);
233 }
234
235 /*
236 * NEEDSWORK:
237 * There is absolutely no reason to write this as a blob object
238 * and create a phony cache entry just to leak. This hack is
239 * primarily to get to the write_entry() machinery that massages
240 * the contents to work-tree format and writes out which only
241 * allows it for a cache entry. The code in write_entry() needs
242 * to be refactored to allow us to feed a <buffer, size, mode>
243 * instead of a cache entry. Such a refactoring would help
244 * merge_recursive as well (it also writes the merge result to the
245 * object database even when it may contain conflicts).
246 */
247 if (write_sha1_file(result_buf.ptr, result_buf.size,
248 blob_type, oid.hash))
249 die(_("Unable to add merge result for '%s'"), path);
250 ce = make_cache_entry(mode, oid.hash, path, 2, 0);
251 if (!ce)
252 die(_("make_cache_entry failed for path '%s'"), path);
253 status = checkout_entry(ce, state, NULL);
254 return status;
255 }
256
257 static int checkout_paths(const struct checkout_opts *opts,
258 const char *revision)
259 {
260 int pos;
261 struct checkout state = CHECKOUT_INIT;
262 static char *ps_matched;
263 struct object_id rev;
264 struct commit *head;
265 int errs = 0;
266 struct lock_file *lock_file;
267
268 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
269 die(_("'%s' cannot be used with updating paths"), "--track");
270
271 if (opts->new_branch_log)
272 die(_("'%s' cannot be used with updating paths"), "-l");
273
274 if (opts->force && opts->patch_mode)
275 die(_("'%s' cannot be used with updating paths"), "-f");
276
277 if (opts->force_detach)
278 die(_("'%s' cannot be used with updating paths"), "--detach");
279
280 if (opts->merge && opts->patch_mode)
281 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
282
283 if (opts->force && opts->merge)
284 die(_("'%s' cannot be used with %s"), "-f", "-m");
285
286 if (opts->new_branch)
287 die(_("Cannot update paths and switch to branch '%s' at the same time."),
288 opts->new_branch);
289
290 if (opts->patch_mode)
291 return run_add_interactive(revision, "--patch=checkout",
292 &opts->pathspec);
293
294 lock_file = xcalloc(1, sizeof(struct lock_file));
295
296 hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
297 if (read_cache_preload(&opts->pathspec) < 0)
298 return error(_("index file corrupt"));
299
300 if (opts->source_tree)
301 read_tree_some(opts->source_tree, &opts->pathspec);
302
303 ps_matched = xcalloc(opts->pathspec.nr, 1);
304
305 /*
306 * Make sure all pathspecs participated in locating the paths
307 * to be checked out.
308 */
309 for (pos = 0; pos < active_nr; pos++) {
310 struct cache_entry *ce = active_cache[pos];
311 ce->ce_flags &= ~CE_MATCHED;
312 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
313 continue;
314 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
315 /*
316 * "git checkout tree-ish -- path", but this entry
317 * is in the original index; it will not be checked
318 * out to the working tree and it does not matter
319 * if pathspec matched this entry. We will not do
320 * anything to this entry at all.
321 */
322 continue;
323 /*
324 * Either this entry came from the tree-ish we are
325 * checking the paths out of, or we are checking out
326 * of the index.
327 *
328 * If it comes from the tree-ish, we already know it
329 * matches the pathspec and could just stamp
330 * CE_MATCHED to it from update_some(). But we still
331 * need ps_matched and read_tree_recursive (and
332 * eventually tree_entry_interesting) cannot fill
333 * ps_matched yet. Once it can, we can avoid calling
334 * match_pathspec() for _all_ entries when
335 * opts->source_tree != NULL.
336 */
337 if (ce_path_match(ce, &opts->pathspec, ps_matched))
338 ce->ce_flags |= CE_MATCHED;
339 }
340
341 if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
342 free(ps_matched);
343 return 1;
344 }
345 free(ps_matched);
346
347 /* "checkout -m path" to recreate conflicted state */
348 if (opts->merge)
349 unmerge_marked_index(&the_index);
350
351 /* Any unmerged paths? */
352 for (pos = 0; pos < active_nr; pos++) {
353 const struct cache_entry *ce = active_cache[pos];
354 if (ce->ce_flags & CE_MATCHED) {
355 if (!ce_stage(ce))
356 continue;
357 if (opts->force) {
358 warning(_("path '%s' is unmerged"), ce->name);
359 } else if (opts->writeout_stage) {
360 errs |= check_stage(opts->writeout_stage, ce, pos);
361 } else if (opts->merge) {
362 errs |= check_stages((1<<2) | (1<<3), ce, pos);
363 } else {
364 errs = 1;
365 error(_("path '%s' is unmerged"), ce->name);
366 }
367 pos = skip_same_name(ce, pos) - 1;
368 }
369 }
370 if (errs)
371 return 1;
372
373 /* Now we are committed to check them out */
374 state.force = 1;
375 state.refresh_cache = 1;
376 state.istate = &the_index;
377 for (pos = 0; pos < active_nr; pos++) {
378 struct cache_entry *ce = active_cache[pos];
379 if (ce->ce_flags & CE_MATCHED) {
380 if (!ce_stage(ce)) {
381 errs |= checkout_entry(ce, &state, NULL);
382 continue;
383 }
384 if (opts->writeout_stage)
385 errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
386 else if (opts->merge)
387 errs |= checkout_merged(pos, &state);
388 pos = skip_same_name(ce, pos) - 1;
389 }
390 }
391
392 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
393 die(_("unable to write new index file"));
394
395 read_ref_full("HEAD", 0, rev.hash, NULL);
396 head = lookup_commit_reference_gently(rev.hash, 1);
397
398 errs |= post_checkout_hook(head, head, 0);
399 return errs;
400 }
401
402 static void show_local_changes(struct object *head,
403 const struct diff_options *opts)
404 {
405 struct rev_info rev;
406 /* I think we want full paths, even if we're in a subdirectory. */
407 init_revisions(&rev, NULL);
408 rev.diffopt.flags = opts->flags;
409 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
410 diff_setup_done(&rev.diffopt);
411 add_pending_object(&rev, head, NULL);
412 run_diff_index(&rev, 0);
413 }
414
415 static void describe_detached_head(const char *msg, struct commit *commit)
416 {
417 struct strbuf sb = STRBUF_INIT;
418 if (!parse_commit(commit))
419 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
420 fprintf(stderr, "%s %s... %s\n", msg,
421 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV), sb.buf);
422 strbuf_release(&sb);
423 }
424
425 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
426 int worktree, int *writeout_error)
427 {
428 struct unpack_trees_options opts;
429 struct tree_desc tree_desc;
430
431 memset(&opts, 0, sizeof(opts));
432 opts.head_idx = -1;
433 opts.update = worktree;
434 opts.skip_unmerged = !worktree;
435 opts.reset = 1;
436 opts.merge = 1;
437 opts.fn = oneway_merge;
438 opts.verbose_update = o->show_progress;
439 opts.src_index = &the_index;
440 opts.dst_index = &the_index;
441 parse_tree(tree);
442 init_tree_desc(&tree_desc, tree->buffer, tree->size);
443 switch (unpack_trees(1, &tree_desc, &opts)) {
444 case -2:
445 *writeout_error = 1;
446 /*
447 * We return 0 nevertheless, as the index is all right
448 * and more importantly we have made best efforts to
449 * update paths in the work tree, and we cannot revert
450 * them.
451 */
452 case 0:
453 return 0;
454 default:
455 return 128;
456 }
457 }
458
459 struct branch_info {
460 const char *name; /* The short name used */
461 const char *path; /* The full name of a real branch */
462 struct commit *commit; /* The named commit */
463 /*
464 * if not null the branch is detached because it's already
465 * checked out in this checkout
466 */
467 char *checkout;
468 };
469
470 static void setup_branch_path(struct branch_info *branch)
471 {
472 struct strbuf buf = STRBUF_INIT;
473
474 strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
475 if (strcmp(buf.buf, branch->name))
476 branch->name = xstrdup(buf.buf);
477 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
478 branch->path = strbuf_detach(&buf, NULL);
479 }
480
481 static int merge_working_tree(const struct checkout_opts *opts,
482 struct branch_info *old,
483 struct branch_info *new,
484 int *writeout_error)
485 {
486 int ret;
487 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
488
489 hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
490 if (read_cache_preload(NULL) < 0)
491 return error(_("index file corrupt"));
492
493 resolve_undo_clear();
494 if (opts->force) {
495 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
496 if (ret)
497 return ret;
498 } else {
499 struct tree_desc trees[2];
500 struct tree *tree;
501 struct unpack_trees_options topts;
502
503 memset(&topts, 0, sizeof(topts));
504 topts.head_idx = -1;
505 topts.src_index = &the_index;
506 topts.dst_index = &the_index;
507
508 setup_unpack_trees_porcelain(&topts, "checkout");
509
510 refresh_cache(REFRESH_QUIET);
511
512 if (unmerged_cache()) {
513 error(_("you need to resolve your current index first"));
514 return 1;
515 }
516
517 /* 2-way merge to the new branch */
518 topts.initial_checkout = is_cache_unborn();
519 topts.update = 1;
520 topts.merge = 1;
521 topts.gently = opts->merge && old->commit;
522 topts.verbose_update = opts->show_progress;
523 topts.fn = twoway_merge;
524 if (opts->overwrite_ignore) {
525 topts.dir = xcalloc(1, sizeof(*topts.dir));
526 topts.dir->flags |= DIR_SHOW_IGNORED;
527 setup_standard_excludes(topts.dir);
528 }
529 tree = parse_tree_indirect(old->commit ?
530 old->commit->object.oid.hash :
531 EMPTY_TREE_SHA1_BIN);
532 init_tree_desc(&trees[0], tree->buffer, tree->size);
533 tree = parse_tree_indirect(new->commit->object.oid.hash);
534 init_tree_desc(&trees[1], tree->buffer, tree->size);
535
536 ret = unpack_trees(2, trees, &topts);
537 if (ret == -1) {
538 /*
539 * Unpack couldn't do a trivial merge; either
540 * give up or do a real merge, depending on
541 * whether the merge flag was used.
542 */
543 struct tree *result;
544 struct tree *work;
545 struct merge_options o;
546 if (!opts->merge)
547 return 1;
548
549 /*
550 * Without old->commit, the below is the same as
551 * the two-tree unpack we already tried and failed.
552 */
553 if (!old->commit)
554 return 1;
555
556 /* Do more real merge */
557
558 /*
559 * We update the index fully, then write the
560 * tree from the index, then merge the new
561 * branch with the current tree, with the old
562 * branch as the base. Then we reset the index
563 * (but not the working tree) to the new
564 * branch, leaving the working tree as the
565 * merged version, but skipping unmerged
566 * entries in the index.
567 */
568
569 add_files_to_cache(NULL, NULL, 0);
570 /*
571 * NEEDSWORK: carrying over local changes
572 * when branches have different end-of-line
573 * normalization (or clean+smudge rules) is
574 * a pain; plumb in an option to set
575 * o.renormalize?
576 */
577 init_merge_options(&o);
578 o.verbosity = 0;
579 work = write_tree_from_memory(&o);
580
581 ret = reset_tree(new->commit->tree, opts, 1,
582 writeout_error);
583 if (ret)
584 return ret;
585 o.ancestor = old->name;
586 o.branch1 = new->name;
587 o.branch2 = "local";
588 ret = merge_trees(&o, new->commit->tree, work,
589 old->commit->tree, &result);
590 if (ret < 0)
591 exit(128);
592 ret = reset_tree(new->commit->tree, opts, 0,
593 writeout_error);
594 strbuf_release(&o.obuf);
595 if (ret)
596 return ret;
597 }
598 }
599
600 if (!active_cache_tree)
601 active_cache_tree = cache_tree();
602
603 if (!cache_tree_fully_valid(active_cache_tree))
604 cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
605
606 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
607 die(_("unable to write new index file"));
608
609 if (!opts->force && !opts->quiet)
610 show_local_changes(&new->commit->object, &opts->diff_options);
611
612 return 0;
613 }
614
615 static void report_tracking(struct branch_info *new)
616 {
617 struct strbuf sb = STRBUF_INIT;
618 struct branch *branch = branch_get(new->name);
619
620 if (!format_tracking_info(branch, &sb))
621 return;
622 fputs(sb.buf, stdout);
623 strbuf_release(&sb);
624 }
625
626 static void update_refs_for_switch(const struct checkout_opts *opts,
627 struct branch_info *old,
628 struct branch_info *new)
629 {
630 struct strbuf msg = STRBUF_INIT;
631 const char *old_desc, *reflog_msg;
632 if (opts->new_branch) {
633 if (opts->new_orphan_branch) {
634 char *refname;
635
636 refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
637 if (opts->new_branch_log &&
638 !should_autocreate_reflog(refname)) {
639 int ret;
640 struct strbuf err = STRBUF_INIT;
641
642 ret = safe_create_reflog(refname, 1, &err);
643 if (ret) {
644 fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
645 opts->new_orphan_branch, err.buf);
646 strbuf_release(&err);
647 free(refname);
648 return;
649 }
650 strbuf_release(&err);
651 }
652 free(refname);
653 }
654 else
655 create_branch(opts->new_branch, new->name,
656 opts->new_branch_force ? 1 : 0,
657 opts->new_branch_log,
658 opts->new_branch_force ? 1 : 0,
659 opts->quiet,
660 opts->track);
661 new->name = opts->new_branch;
662 setup_branch_path(new);
663 }
664
665 old_desc = old->name;
666 if (!old_desc && old->commit)
667 old_desc = oid_to_hex(&old->commit->object.oid);
668
669 reflog_msg = getenv("GIT_REFLOG_ACTION");
670 if (!reflog_msg)
671 strbuf_addf(&msg, "checkout: moving from %s to %s",
672 old_desc ? old_desc : "(invalid)", new->name);
673 else
674 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
675
676 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
677 /* Nothing to do. */
678 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
679 update_ref(msg.buf, "HEAD", new->commit->object.oid.hash, NULL,
680 REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
681 if (!opts->quiet) {
682 if (old->path &&
683 advice_detached_head && !opts->force_detach)
684 detach_advice(new->name);
685 describe_detached_head(_("HEAD is now at"), new->commit);
686 }
687 } else if (new->path) { /* Switch branches. */
688 if (create_symref("HEAD", new->path, msg.buf) < 0)
689 die(_("unable to update HEAD"));
690 if (!opts->quiet) {
691 if (old->path && !strcmp(new->path, old->path)) {
692 if (opts->new_branch_force)
693 fprintf(stderr, _("Reset branch '%s'\n"),
694 new->name);
695 else
696 fprintf(stderr, _("Already on '%s'\n"),
697 new->name);
698 } else if (opts->new_branch) {
699 if (opts->branch_exists)
700 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
701 else
702 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
703 } else {
704 fprintf(stderr, _("Switched to branch '%s'\n"),
705 new->name);
706 }
707 }
708 if (old->path && old->name) {
709 if (!ref_exists(old->path) && reflog_exists(old->path))
710 delete_reflog(old->path);
711 }
712 }
713 remove_branch_state();
714 strbuf_release(&msg);
715 if (!opts->quiet &&
716 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
717 report_tracking(new);
718 }
719
720 static int add_pending_uninteresting_ref(const char *refname,
721 const struct object_id *oid,
722 int flags, void *cb_data)
723 {
724 add_pending_sha1(cb_data, refname, oid->hash, UNINTERESTING);
725 return 0;
726 }
727
728 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
729 {
730 strbuf_addstr(sb, " ");
731 strbuf_add_unique_abbrev(sb, commit->object.oid.hash, DEFAULT_ABBREV);
732 strbuf_addch(sb, ' ');
733 if (!parse_commit(commit))
734 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
735 strbuf_addch(sb, '\n');
736 }
737
738 #define ORPHAN_CUTOFF 4
739 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
740 {
741 struct commit *c, *last = NULL;
742 struct strbuf sb = STRBUF_INIT;
743 int lost = 0;
744 while ((c = get_revision(revs)) != NULL) {
745 if (lost < ORPHAN_CUTOFF)
746 describe_one_orphan(&sb, c);
747 last = c;
748 lost++;
749 }
750 if (ORPHAN_CUTOFF < lost) {
751 int more = lost - ORPHAN_CUTOFF;
752 if (more == 1)
753 describe_one_orphan(&sb, last);
754 else
755 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
756 }
757
758 fprintf(stderr,
759 Q_(
760 /* The singular version */
761 "Warning: you are leaving %d commit behind, "
762 "not connected to\n"
763 "any of your branches:\n\n"
764 "%s\n",
765 /* The plural version */
766 "Warning: you are leaving %d commits behind, "
767 "not connected to\n"
768 "any of your branches:\n\n"
769 "%s\n",
770 /* Give ngettext() the count */
771 lost),
772 lost,
773 sb.buf);
774 strbuf_release(&sb);
775
776 if (advice_detached_head)
777 fprintf(stderr,
778 Q_(
779 /* The singular version */
780 "If you want to keep it by creating a new branch, "
781 "this may be a good time\nto do so with:\n\n"
782 " git branch <new-branch-name> %s\n\n",
783 /* The plural version */
784 "If you want to keep them by creating a new branch, "
785 "this may be a good time\nto do so with:\n\n"
786 " git branch <new-branch-name> %s\n\n",
787 /* Give ngettext() the count */
788 lost),
789 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV));
790 }
791
792 /*
793 * We are about to leave commit that was at the tip of a detached
794 * HEAD. If it is not reachable from any ref, this is the last chance
795 * for the user to do so without resorting to reflog.
796 */
797 static void orphaned_commit_warning(struct commit *old, struct commit *new)
798 {
799 struct rev_info revs;
800 struct object *object = &old->object;
801 struct object_array refs;
802
803 init_revisions(&revs, NULL);
804 setup_revisions(0, NULL, &revs, NULL);
805
806 object->flags &= ~UNINTERESTING;
807 add_pending_object(&revs, object, oid_to_hex(&object->oid));
808
809 for_each_ref(add_pending_uninteresting_ref, &revs);
810 add_pending_sha1(&revs, "HEAD", new->object.oid.hash, UNINTERESTING);
811
812 refs = revs.pending;
813 revs.leak_pending = 1;
814
815 if (prepare_revision_walk(&revs))
816 die(_("internal error in revision walk"));
817 if (!(old->object.flags & UNINTERESTING))
818 suggest_reattach(old, &revs);
819 else
820 describe_detached_head(_("Previous HEAD position was"), old);
821
822 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
823 free(refs.objects);
824 }
825
826 static int switch_branches(const struct checkout_opts *opts,
827 struct branch_info *new)
828 {
829 int ret = 0;
830 struct branch_info old;
831 void *path_to_free;
832 struct object_id rev;
833 int flag, writeout_error = 0;
834 memset(&old, 0, sizeof(old));
835 old.path = path_to_free = resolve_refdup("HEAD", 0, rev.hash, &flag);
836 old.commit = lookup_commit_reference_gently(rev.hash, 1);
837 if (!(flag & REF_ISSYMREF))
838 old.path = NULL;
839
840 if (old.path)
841 skip_prefix(old.path, "refs/heads/", &old.name);
842
843 if (!new->name) {
844 new->name = "HEAD";
845 new->commit = old.commit;
846 if (!new->commit)
847 die(_("You are on a branch yet to be born"));
848 parse_commit_or_die(new->commit);
849 }
850
851 ret = merge_working_tree(opts, &old, new, &writeout_error);
852 if (ret) {
853 free(path_to_free);
854 return ret;
855 }
856
857 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
858 orphaned_commit_warning(old.commit, new->commit);
859
860 update_refs_for_switch(opts, &old, new);
861
862 ret = post_checkout_hook(old.commit, new->commit, 1);
863 free(path_to_free);
864 return ret || writeout_error;
865 }
866
867 static int git_checkout_config(const char *var, const char *value, void *cb)
868 {
869 if (!strcmp(var, "diff.ignoresubmodules")) {
870 struct checkout_opts *opts = cb;
871 handle_ignore_submodules_arg(&opts->diff_options, value);
872 return 0;
873 }
874
875 if (starts_with(var, "submodule."))
876 return parse_submodule_config_option(var, value);
877
878 return git_xmerge_config(var, value, NULL);
879 }
880
881 struct tracking_name_data {
882 /* const */ char *src_ref;
883 char *dst_ref;
884 struct object_id *dst_oid;
885 int unique;
886 };
887
888 static int check_tracking_name(struct remote *remote, void *cb_data)
889 {
890 struct tracking_name_data *cb = cb_data;
891 struct refspec query;
892 memset(&query, 0, sizeof(struct refspec));
893 query.src = cb->src_ref;
894 if (remote_find_tracking(remote, &query) ||
895 get_oid(query.dst, cb->dst_oid)) {
896 free(query.dst);
897 return 0;
898 }
899 if (cb->dst_ref) {
900 free(query.dst);
901 cb->unique = 0;
902 return 0;
903 }
904 cb->dst_ref = query.dst;
905 return 0;
906 }
907
908 static const char *unique_tracking_name(const char *name, struct object_id *oid)
909 {
910 struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
911 cb_data.src_ref = xstrfmt("refs/heads/%s", name);
912 cb_data.dst_oid = oid;
913 for_each_remote(check_tracking_name, &cb_data);
914 free(cb_data.src_ref);
915 if (cb_data.unique)
916 return cb_data.dst_ref;
917 free(cb_data.dst_ref);
918 return NULL;
919 }
920
921 static int parse_branchname_arg(int argc, const char **argv,
922 int dwim_new_local_branch_ok,
923 struct branch_info *new,
924 struct checkout_opts *opts,
925 struct object_id *rev)
926 {
927 struct tree **source_tree = &opts->source_tree;
928 const char **new_branch = &opts->new_branch;
929 int argcount = 0;
930 struct object_id branch_rev;
931 const char *arg;
932 int dash_dash_pos;
933 int has_dash_dash = 0;
934 int i;
935
936 /*
937 * case 1: git checkout <ref> -- [<paths>]
938 *
939 * <ref> must be a valid tree, everything after the '--' must be
940 * a path.
941 *
942 * case 2: git checkout -- [<paths>]
943 *
944 * everything after the '--' must be paths.
945 *
946 * case 3: git checkout <something> [--]
947 *
948 * (a) If <something> is a commit, that is to
949 * switch to the branch or detach HEAD at it. As a special case,
950 * if <something> is A...B (missing A or B means HEAD but you can
951 * omit at most one side), and if there is a unique merge base
952 * between A and B, A...B names that merge base.
953 *
954 * (b) If <something> is _not_ a commit, either "--" is present
955 * or <something> is not a path, no -t or -b was given, and
956 * and there is a tracking branch whose name is <something>
957 * in one and only one remote, then this is a short-hand to
958 * fork local <something> from that remote-tracking branch.
959 *
960 * (c) Otherwise, if "--" is present, treat it like case (1).
961 *
962 * (d) Otherwise :
963 * - if it's a reference, treat it like case (1)
964 * - else if it's a path, treat it like case (2)
965 * - else: fail.
966 *
967 * case 4: git checkout <something> <paths>
968 *
969 * The first argument must not be ambiguous.
970 * - If it's *only* a reference, treat it like case (1).
971 * - If it's only a path, treat it like case (2).
972 * - else: fail.
973 *
974 */
975 if (!argc)
976 return 0;
977
978 arg = argv[0];
979 dash_dash_pos = -1;
980 for (i = 0; i < argc; i++) {
981 if (!strcmp(argv[i], "--")) {
982 dash_dash_pos = i;
983 break;
984 }
985 }
986 if (dash_dash_pos == 0)
987 return 1; /* case (2) */
988 else if (dash_dash_pos == 1)
989 has_dash_dash = 1; /* case (3) or (1) */
990 else if (dash_dash_pos >= 2)
991 die(_("only one reference expected, %d given."), dash_dash_pos);
992
993 if (!strcmp(arg, "-"))
994 arg = "@{-1}";
995
996 if (get_oid_mb(arg, rev)) {
997 /*
998 * Either case (3) or (4), with <something> not being
999 * a commit, or an attempt to use case (1) with an
1000 * invalid ref.
1001 *
1002 * It's likely an error, but we need to find out if
1003 * we should auto-create the branch, case (3).(b).
1004 */
1005 int recover_with_dwim = dwim_new_local_branch_ok;
1006
1007 if (!has_dash_dash &&
1008 (check_filename(opts->prefix, arg) || !no_wildcard(arg)))
1009 recover_with_dwim = 0;
1010 /*
1011 * Accept "git checkout foo" and "git checkout foo --"
1012 * as candidates for dwim.
1013 */
1014 if (!(argc == 1 && !has_dash_dash) &&
1015 !(argc == 2 && has_dash_dash))
1016 recover_with_dwim = 0;
1017
1018 if (recover_with_dwim) {
1019 const char *remote = unique_tracking_name(arg, rev);
1020 if (remote) {
1021 *new_branch = arg;
1022 arg = remote;
1023 /* DWIMmed to create local branch, case (3).(b) */
1024 } else {
1025 recover_with_dwim = 0;
1026 }
1027 }
1028
1029 if (!recover_with_dwim) {
1030 if (has_dash_dash)
1031 die(_("invalid reference: %s"), arg);
1032 return argcount;
1033 }
1034 }
1035
1036 /* we can't end up being in (2) anymore, eat the argument */
1037 argcount++;
1038 argv++;
1039 argc--;
1040
1041 new->name = arg;
1042 setup_branch_path(new);
1043
1044 if (!check_refname_format(new->path, 0) &&
1045 !read_ref(new->path, branch_rev.hash))
1046 oidcpy(rev, &branch_rev);
1047 else
1048 new->path = NULL; /* not an existing branch */
1049
1050 new->commit = lookup_commit_reference_gently(rev->hash, 1);
1051 if (!new->commit) {
1052 /* not a commit */
1053 *source_tree = parse_tree_indirect(rev->hash);
1054 } else {
1055 parse_commit_or_die(new->commit);
1056 *source_tree = new->commit->tree;
1057 }
1058
1059 if (!*source_tree) /* case (1): want a tree */
1060 die(_("reference is not a tree: %s"), arg);
1061 if (!has_dash_dash) { /* case (3).(d) -> (1) */
1062 /*
1063 * Do not complain the most common case
1064 * git checkout branch
1065 * even if there happen to be a file called 'branch';
1066 * it would be extremely annoying.
1067 */
1068 if (argc)
1069 verify_non_filename(opts->prefix, arg);
1070 } else {
1071 argcount++;
1072 argv++;
1073 argc--;
1074 }
1075
1076 return argcount;
1077 }
1078
1079 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1080 {
1081 int status;
1082 struct strbuf branch_ref = STRBUF_INIT;
1083
1084 if (!opts->new_branch)
1085 die(_("You are on a branch yet to be born"));
1086 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1087 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1088 strbuf_release(&branch_ref);
1089 if (!opts->quiet)
1090 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1091 opts->new_branch);
1092 return status;
1093 }
1094
1095 static int checkout_branch(struct checkout_opts *opts,
1096 struct branch_info *new)
1097 {
1098 if (opts->pathspec.nr)
1099 die(_("paths cannot be used with switching branches"));
1100
1101 if (opts->patch_mode)
1102 die(_("'%s' cannot be used with switching branches"),
1103 "--patch");
1104
1105 if (opts->writeout_stage)
1106 die(_("'%s' cannot be used with switching branches"),
1107 "--ours/--theirs");
1108
1109 if (opts->force && opts->merge)
1110 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1111
1112 if (opts->force_detach && opts->new_branch)
1113 die(_("'%s' cannot be used with '%s'"),
1114 "--detach", "-b/-B/--orphan");
1115
1116 if (opts->new_orphan_branch) {
1117 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1118 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1119 } else if (opts->force_detach) {
1120 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1121 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1122 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1123 opts->track = git_branch_track;
1124
1125 if (new->name && !new->commit)
1126 die(_("Cannot switch branch to a non-commit '%s'"),
1127 new->name);
1128
1129 if (new->path && !opts->force_detach && !opts->new_branch &&
1130 !opts->ignore_other_worktrees) {
1131 struct object_id oid;
1132 int flag;
1133 char *head_ref = resolve_refdup("HEAD", 0, oid.hash, &flag);
1134 if (head_ref &&
1135 (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)))
1136 die_if_checked_out(new->path, 1);
1137 free(head_ref);
1138 }
1139
1140 if (!new->commit && opts->new_branch) {
1141 struct object_id rev;
1142 int flag;
1143
1144 if (!read_ref_full("HEAD", 0, rev.hash, &flag) &&
1145 (flag & REF_ISSYMREF) && is_null_oid(&rev))
1146 return switch_unborn_to_new_branch(opts);
1147 }
1148 return switch_branches(opts, new);
1149 }
1150
1151 int cmd_checkout(int argc, const char **argv, const char *prefix)
1152 {
1153 struct checkout_opts opts;
1154 struct branch_info new;
1155 char *conflict_style = NULL;
1156 int dwim_new_local_branch = 1;
1157 struct option options[] = {
1158 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1159 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1160 N_("create and checkout a new branch")),
1161 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1162 N_("create/reset and checkout a branch")),
1163 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1164 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach HEAD at named commit")),
1165 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1166 BRANCH_TRACK_EXPLICIT),
1167 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1168 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1169 2),
1170 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1171 3),
1172 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1173 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1174 OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1175 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1176 N_("conflict style (merge or diff3)")),
1177 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1178 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1179 N_("do not limit pathspecs to sparse entries only")),
1180 OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1181 N_("second guess 'git checkout <no-such-branch>'")),
1182 OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1183 N_("do not check if another worktree is holding the given ref")),
1184 { OPTION_CALLBACK, 0, "recurse-submodules", &recurse_submodules,
1185 "checkout", "control recursive updating of submodules",
1186 PARSE_OPT_OPTARG, option_parse_recurse_submodules },
1187 OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
1188 OPT_END(),
1189 };
1190
1191 memset(&opts, 0, sizeof(opts));
1192 memset(&new, 0, sizeof(new));
1193 opts.overwrite_ignore = 1;
1194 opts.prefix = prefix;
1195 opts.show_progress = -1;
1196
1197 gitmodules_config();
1198 git_config(git_checkout_config, &opts);
1199
1200 opts.track = BRANCH_TRACK_UNSPECIFIED;
1201
1202 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1203 PARSE_OPT_KEEP_DASHDASH);
1204
1205 if (opts.show_progress < 0) {
1206 if (opts.quiet)
1207 opts.show_progress = 0;
1208 else
1209 opts.show_progress = isatty(2);
1210 }
1211
1212 if (conflict_style) {
1213 opts.merge = 1; /* implied */
1214 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1215 }
1216
1217 if (recurse_submodules != RECURSE_SUBMODULES_OFF) {
1218 git_config(submodule_config, NULL);
1219 if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT)
1220 set_config_update_recurse_submodules(recurse_submodules);
1221 }
1222
1223 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1224 die(_("-b, -B and --orphan are mutually exclusive"));
1225
1226 /*
1227 * From here on, new_branch will contain the branch to be checked out,
1228 * and new_branch_force and new_orphan_branch will tell us which one of
1229 * -b/-B/--orphan is being used.
1230 */
1231 if (opts.new_branch_force)
1232 opts.new_branch = opts.new_branch_force;
1233
1234 if (opts.new_orphan_branch)
1235 opts.new_branch = opts.new_orphan_branch;
1236
1237 /* --track without -b/-B/--orphan should DWIM */
1238 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1239 const char *argv0 = argv[0];
1240 if (!argc || !strcmp(argv0, "--"))
1241 die (_("--track needs a branch name"));
1242 skip_prefix(argv0, "refs/", &argv0);
1243 skip_prefix(argv0, "remotes/", &argv0);
1244 argv0 = strchr(argv0, '/');
1245 if (!argv0 || !argv0[1])
1246 die (_("Missing branch name; try -b"));
1247 opts.new_branch = argv0 + 1;
1248 }
1249
1250 /*
1251 * Extract branch name from command line arguments, so
1252 * all that is left is pathspecs.
1253 *
1254 * Handle
1255 *
1256 * 1) git checkout <tree> -- [<paths>]
1257 * 2) git checkout -- [<paths>]
1258 * 3) git checkout <something> [<paths>]
1259 *
1260 * including "last branch" syntax and DWIM-ery for names of
1261 * remote branches, erroring out for invalid or ambiguous cases.
1262 */
1263 if (argc) {
1264 struct object_id rev;
1265 int dwim_ok =
1266 !opts.patch_mode &&
1267 dwim_new_local_branch &&
1268 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1269 !opts.new_branch;
1270 int n = parse_branchname_arg(argc, argv, dwim_ok,
1271 &new, &opts, &rev);
1272 argv += n;
1273 argc -= n;
1274 }
1275
1276 if (argc) {
1277 parse_pathspec(&opts.pathspec, 0,
1278 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1279 prefix, argv);
1280
1281 if (!opts.pathspec.nr)
1282 die(_("invalid path specification"));
1283
1284 /*
1285 * Try to give more helpful suggestion.
1286 * new_branch && argc > 1 will be caught later.
1287 */
1288 if (opts.new_branch && argc == 1)
1289 die(_("Cannot update paths and switch to branch '%s' at the same time.\n"
1290 "Did you intend to checkout '%s' which can not be resolved as commit?"),
1291 opts.new_branch, argv[0]);
1292
1293 if (opts.force_detach)
1294 die(_("git checkout: --detach does not take a path argument '%s'"),
1295 argv[0]);
1296
1297 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1298 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1299 "checking out of the index."));
1300 }
1301
1302 if (opts.new_branch) {
1303 struct strbuf buf = STRBUF_INIT;
1304
1305 opts.branch_exists =
1306 validate_new_branchname(opts.new_branch, &buf,
1307 !!opts.new_branch_force,
1308 !!opts.new_branch_force);
1309
1310 strbuf_release(&buf);
1311 }
1312
1313 if (opts.patch_mode || opts.pathspec.nr)
1314 return checkout_paths(&opts, new.name);
1315 else
1316 return checkout_branch(&opts, &new);
1317 }