Merge branch 'hi/merge-verify-sig-config'
[git/git.git] / builtin / checkout.c
1 #include "builtin.h"
2 #include "config.h"
3 #include "checkout.h"
4 #include "lockfile.h"
5 #include "parse-options.h"
6 #include "refs.h"
7 #include "commit.h"
8 #include "tree.h"
9 #include "tree-walk.h"
10 #include "cache-tree.h"
11 #include "unpack-trees.h"
12 #include "dir.h"
13 #include "run-command.h"
14 #include "merge-recursive.h"
15 #include "branch.h"
16 #include "diff.h"
17 #include "revision.h"
18 #include "remote.h"
19 #include "blob.h"
20 #include "xdiff-interface.h"
21 #include "ll-merge.h"
22 #include "resolve-undo.h"
23 #include "submodule-config.h"
24 #include "submodule.h"
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 struct checkout_opts {
33 int patch_mode;
34 int quiet;
35 int merge;
36 int force;
37 int force_detach;
38 int writeout_stage;
39 int overwrite_ignore;
40 int ignore_skipworktree;
41 int ignore_other_worktrees;
42 int show_progress;
43
44 const char *new_branch;
45 const char *new_branch_force;
46 const char *new_orphan_branch;
47 int new_branch_log;
48 enum branch_track track;
49 struct diff_options diff_options;
50
51 int branch_exists;
52 const char *prefix;
53 struct pathspec pathspec;
54 struct tree *source_tree;
55 };
56
57 static int post_checkout_hook(struct commit *old, struct commit *new,
58 int changed)
59 {
60 return run_hook_le(NULL, "post-checkout",
61 oid_to_hex(old ? &old->object.oid : &null_oid),
62 oid_to_hex(new ? &new->object.oid : &null_oid),
63 changed ? "1" : "0", NULL);
64 /* "new" can be NULL when checking out from the index before
65 a commit exists. */
66
67 }
68
69 static int update_some(const unsigned char *sha1, struct strbuf *base,
70 const char *pathname, unsigned mode, int stage, void *context)
71 {
72 int len;
73 struct cache_entry *ce;
74 int pos;
75
76 if (S_ISDIR(mode))
77 return READ_TREE_RECURSIVE;
78
79 len = base->len + strlen(pathname);
80 ce = xcalloc(1, cache_entry_size(len));
81 hashcpy(ce->oid.hash, sha1);
82 memcpy(ce->name, base->buf, base->len);
83 memcpy(ce->name + base->len, pathname, len - base->len);
84 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
85 ce->ce_namelen = len;
86 ce->ce_mode = create_ce_mode(mode);
87
88 /*
89 * If the entry is the same as the current index, we can leave the old
90 * entry in place. Whether it is UPTODATE or not, checkout_entry will
91 * do the right thing.
92 */
93 pos = cache_name_pos(ce->name, ce->ce_namelen);
94 if (pos >= 0) {
95 struct cache_entry *old = active_cache[pos];
96 if (ce->ce_mode == old->ce_mode &&
97 !oidcmp(&ce->oid, &old->oid)) {
98 old->ce_flags |= CE_UPDATE;
99 free(ce);
100 return 0;
101 }
102 }
103
104 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
105 return 0;
106 }
107
108 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
109 {
110 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
111
112 /* update the index with the given tree's info
113 * for all args, expanding wildcards, and exit
114 * with any non-zero return code.
115 */
116 return 0;
117 }
118
119 static int skip_same_name(const struct cache_entry *ce, int pos)
120 {
121 while (++pos < active_nr &&
122 !strcmp(active_cache[pos]->name, ce->name))
123 ; /* skip */
124 return pos;
125 }
126
127 static int check_stage(int stage, const struct cache_entry *ce, int pos)
128 {
129 while (pos < active_nr &&
130 !strcmp(active_cache[pos]->name, ce->name)) {
131 if (ce_stage(active_cache[pos]) == stage)
132 return 0;
133 pos++;
134 }
135 if (stage == 2)
136 return error(_("path '%s' does not have our version"), ce->name);
137 else
138 return error(_("path '%s' does not have their version"), ce->name);
139 }
140
141 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
142 {
143 unsigned seen = 0;
144 const char *name = ce->name;
145
146 while (pos < active_nr) {
147 ce = active_cache[pos];
148 if (strcmp(name, ce->name))
149 break;
150 seen |= (1 << ce_stage(ce));
151 pos++;
152 }
153 if ((stages & seen) != stages)
154 return error(_("path '%s' does not have all necessary versions"),
155 name);
156 return 0;
157 }
158
159 static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
160 const struct checkout *state)
161 {
162 while (pos < active_nr &&
163 !strcmp(active_cache[pos]->name, ce->name)) {
164 if (ce_stage(active_cache[pos]) == stage)
165 return checkout_entry(active_cache[pos], state, NULL);
166 pos++;
167 }
168 if (stage == 2)
169 return error(_("path '%s' does not have our version"), ce->name);
170 else
171 return error(_("path '%s' does not have their version"), ce->name);
172 }
173
174 static int checkout_merged(int pos, const struct checkout *state)
175 {
176 struct cache_entry *ce = active_cache[pos];
177 const char *path = ce->name;
178 mmfile_t ancestor, ours, theirs;
179 int status;
180 struct object_id oid;
181 mmbuffer_t result_buf;
182 struct object_id threeway[3];
183 unsigned mode = 0;
184
185 memset(threeway, 0, sizeof(threeway));
186 while (pos < active_nr) {
187 int stage;
188 stage = ce_stage(ce);
189 if (!stage || strcmp(path, ce->name))
190 break;
191 oidcpy(&threeway[stage - 1], &ce->oid);
192 if (stage == 2)
193 mode = create_ce_mode(ce->ce_mode);
194 pos++;
195 ce = active_cache[pos];
196 }
197 if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
198 return error(_("path '%s' does not have necessary versions"), path);
199
200 read_mmblob(&ancestor, &threeway[0]);
201 read_mmblob(&ours, &threeway[1]);
202 read_mmblob(&theirs, &threeway[2]);
203
204 /*
205 * NEEDSWORK: re-create conflicts from merges with
206 * merge.renormalize set, too
207 */
208 status = ll_merge(&result_buf, path, &ancestor, "base",
209 &ours, "ours", &theirs, "theirs", NULL);
210 free(ancestor.ptr);
211 free(ours.ptr);
212 free(theirs.ptr);
213 if (status < 0 || !result_buf.ptr) {
214 free(result_buf.ptr);
215 return error(_("path '%s': cannot merge"), path);
216 }
217
218 /*
219 * NEEDSWORK:
220 * There is absolutely no reason to write this as a blob object
221 * and create a phony cache entry. This hack is primarily to get
222 * to the write_entry() machinery that massages the contents to
223 * work-tree format and writes out which only allows it for a
224 * cache entry. The code in write_entry() needs to be refactored
225 * to allow us to feed a <buffer, size, mode> instead of a cache
226 * entry. Such a refactoring would help merge_recursive as well
227 * (it also writes the merge result to the object database even
228 * when it may contain conflicts).
229 */
230 if (write_sha1_file(result_buf.ptr, result_buf.size,
231 blob_type, oid.hash))
232 die(_("Unable to add merge result for '%s'"), path);
233 free(result_buf.ptr);
234 ce = make_cache_entry(mode, oid.hash, path, 2, 0);
235 if (!ce)
236 die(_("make_cache_entry failed for path '%s'"), path);
237 status = checkout_entry(ce, state, NULL);
238 free(ce);
239 return status;
240 }
241
242 static int checkout_paths(const struct checkout_opts *opts,
243 const char *revision)
244 {
245 int pos;
246 struct checkout state = CHECKOUT_INIT;
247 static char *ps_matched;
248 struct object_id rev;
249 struct commit *head;
250 int errs = 0;
251 struct lock_file lock_file = LOCK_INIT;
252
253 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
254 die(_("'%s' cannot be used with updating paths"), "--track");
255
256 if (opts->new_branch_log)
257 die(_("'%s' cannot be used with updating paths"), "-l");
258
259 if (opts->force && opts->patch_mode)
260 die(_("'%s' cannot be used with updating paths"), "-f");
261
262 if (opts->force_detach)
263 die(_("'%s' cannot be used with updating paths"), "--detach");
264
265 if (opts->merge && opts->patch_mode)
266 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
267
268 if (opts->force && opts->merge)
269 die(_("'%s' cannot be used with %s"), "-f", "-m");
270
271 if (opts->new_branch)
272 die(_("Cannot update paths and switch to branch '%s' at the same time."),
273 opts->new_branch);
274
275 if (opts->patch_mode)
276 return run_add_interactive(revision, "--patch=checkout",
277 &opts->pathspec);
278
279 hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
280 if (read_cache_preload(&opts->pathspec) < 0)
281 return error(_("index file corrupt"));
282
283 if (opts->source_tree)
284 read_tree_some(opts->source_tree, &opts->pathspec);
285
286 ps_matched = xcalloc(opts->pathspec.nr, 1);
287
288 /*
289 * Make sure all pathspecs participated in locating the paths
290 * to be checked out.
291 */
292 for (pos = 0; pos < active_nr; pos++) {
293 struct cache_entry *ce = active_cache[pos];
294 ce->ce_flags &= ~CE_MATCHED;
295 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
296 continue;
297 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
298 /*
299 * "git checkout tree-ish -- path", but this entry
300 * is in the original index; it will not be checked
301 * out to the working tree and it does not matter
302 * if pathspec matched this entry. We will not do
303 * anything to this entry at all.
304 */
305 continue;
306 /*
307 * Either this entry came from the tree-ish we are
308 * checking the paths out of, or we are checking out
309 * of the index.
310 *
311 * If it comes from the tree-ish, we already know it
312 * matches the pathspec and could just stamp
313 * CE_MATCHED to it from update_some(). But we still
314 * need ps_matched and read_tree_recursive (and
315 * eventually tree_entry_interesting) cannot fill
316 * ps_matched yet. Once it can, we can avoid calling
317 * match_pathspec() for _all_ entries when
318 * opts->source_tree != NULL.
319 */
320 if (ce_path_match(ce, &opts->pathspec, ps_matched))
321 ce->ce_flags |= CE_MATCHED;
322 }
323
324 if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
325 free(ps_matched);
326 return 1;
327 }
328 free(ps_matched);
329
330 /* "checkout -m path" to recreate conflicted state */
331 if (opts->merge)
332 unmerge_marked_index(&the_index);
333
334 /* Any unmerged paths? */
335 for (pos = 0; pos < active_nr; pos++) {
336 const struct cache_entry *ce = active_cache[pos];
337 if (ce->ce_flags & CE_MATCHED) {
338 if (!ce_stage(ce))
339 continue;
340 if (opts->force) {
341 warning(_("path '%s' is unmerged"), ce->name);
342 } else if (opts->writeout_stage) {
343 errs |= check_stage(opts->writeout_stage, ce, pos);
344 } else if (opts->merge) {
345 errs |= check_stages((1<<2) | (1<<3), ce, pos);
346 } else {
347 errs = 1;
348 error(_("path '%s' is unmerged"), ce->name);
349 }
350 pos = skip_same_name(ce, pos) - 1;
351 }
352 }
353 if (errs)
354 return 1;
355
356 /* Now we are committed to check them out */
357 state.force = 1;
358 state.refresh_cache = 1;
359 state.istate = &the_index;
360
361 enable_delayed_checkout(&state);
362 for (pos = 0; pos < active_nr; pos++) {
363 struct cache_entry *ce = active_cache[pos];
364 if (ce->ce_flags & CE_MATCHED) {
365 if (!ce_stage(ce)) {
366 errs |= checkout_entry(ce, &state, NULL);
367 continue;
368 }
369 if (opts->writeout_stage)
370 errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
371 else if (opts->merge)
372 errs |= checkout_merged(pos, &state);
373 pos = skip_same_name(ce, pos) - 1;
374 }
375 }
376 errs |= finish_delayed_checkout(&state);
377
378 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
379 die(_("unable to write new index file"));
380
381 read_ref_full("HEAD", 0, &rev, NULL);
382 head = lookup_commit_reference_gently(&rev, 1);
383
384 errs |= post_checkout_hook(head, head, 0);
385 return errs;
386 }
387
388 static void show_local_changes(struct object *head,
389 const struct diff_options *opts)
390 {
391 struct rev_info rev;
392 /* I think we want full paths, even if we're in a subdirectory. */
393 init_revisions(&rev, NULL);
394 rev.diffopt.flags = opts->flags;
395 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
396 diff_setup_done(&rev.diffopt);
397 add_pending_object(&rev, head, NULL);
398 run_diff_index(&rev, 0);
399 }
400
401 static void describe_detached_head(const char *msg, struct commit *commit)
402 {
403 struct strbuf sb = STRBUF_INIT;
404
405 if (!parse_commit(commit))
406 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
407 if (print_sha1_ellipsis()) {
408 fprintf(stderr, "%s %s... %s\n", msg,
409 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV), sb.buf);
410 } else {
411 fprintf(stderr, "%s %s %s\n", msg,
412 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV), sb.buf);
413 }
414 strbuf_release(&sb);
415 }
416
417 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
418 int worktree, int *writeout_error)
419 {
420 struct unpack_trees_options opts;
421 struct tree_desc tree_desc;
422
423 memset(&opts, 0, sizeof(opts));
424 opts.head_idx = -1;
425 opts.update = worktree;
426 opts.skip_unmerged = !worktree;
427 opts.reset = 1;
428 opts.merge = 1;
429 opts.fn = oneway_merge;
430 opts.verbose_update = o->show_progress;
431 opts.src_index = &the_index;
432 opts.dst_index = &the_index;
433 parse_tree(tree);
434 init_tree_desc(&tree_desc, tree->buffer, tree->size);
435 switch (unpack_trees(1, &tree_desc, &opts)) {
436 case -2:
437 *writeout_error = 1;
438 /*
439 * We return 0 nevertheless, as the index is all right
440 * and more importantly we have made best efforts to
441 * update paths in the work tree, and we cannot revert
442 * them.
443 */
444 /* fallthrough */
445 case 0:
446 return 0;
447 default:
448 return 128;
449 }
450 }
451
452 struct branch_info {
453 const char *name; /* The short name used */
454 const char *path; /* The full name of a real branch */
455 struct commit *commit; /* The named commit */
456 /*
457 * if not null the branch is detached because it's already
458 * checked out in this checkout
459 */
460 char *checkout;
461 };
462
463 static void setup_branch_path(struct branch_info *branch)
464 {
465 struct strbuf buf = STRBUF_INIT;
466
467 strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
468 if (strcmp(buf.buf, branch->name))
469 branch->name = xstrdup(buf.buf);
470 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
471 branch->path = strbuf_detach(&buf, NULL);
472 }
473
474 static int merge_working_tree(const struct checkout_opts *opts,
475 struct branch_info *old,
476 struct branch_info *new,
477 int *writeout_error)
478 {
479 int ret;
480 struct lock_file lock_file = LOCK_INIT;
481
482 hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
483 if (read_cache_preload(NULL) < 0)
484 return error(_("index file corrupt"));
485
486 resolve_undo_clear();
487 if (opts->force) {
488 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
489 if (ret)
490 return ret;
491 } else {
492 struct tree_desc trees[2];
493 struct tree *tree;
494 struct unpack_trees_options topts;
495
496 memset(&topts, 0, sizeof(topts));
497 topts.head_idx = -1;
498 topts.src_index = &the_index;
499 topts.dst_index = &the_index;
500
501 setup_unpack_trees_porcelain(&topts, "checkout");
502
503 refresh_cache(REFRESH_QUIET);
504
505 if (unmerged_cache()) {
506 error(_("you need to resolve your current index first"));
507 return 1;
508 }
509
510 /* 2-way merge to the new branch */
511 topts.initial_checkout = is_cache_unborn();
512 topts.update = 1;
513 topts.merge = 1;
514 topts.gently = opts->merge && old->commit;
515 topts.verbose_update = opts->show_progress;
516 topts.fn = twoway_merge;
517 if (opts->overwrite_ignore) {
518 topts.dir = xcalloc(1, sizeof(*topts.dir));
519 topts.dir->flags |= DIR_SHOW_IGNORED;
520 setup_standard_excludes(topts.dir);
521 }
522 tree = parse_tree_indirect(old->commit ?
523 &old->commit->object.oid :
524 the_hash_algo->empty_tree);
525 init_tree_desc(&trees[0], tree->buffer, tree->size);
526 tree = parse_tree_indirect(&new->commit->object.oid);
527 init_tree_desc(&trees[1], tree->buffer, tree->size);
528
529 ret = unpack_trees(2, trees, &topts);
530 if (ret == -1) {
531 /*
532 * Unpack couldn't do a trivial merge; either
533 * give up or do a real merge, depending on
534 * whether the merge flag was used.
535 */
536 struct tree *result;
537 struct tree *work;
538 struct merge_options o;
539 if (!opts->merge)
540 return 1;
541
542 /*
543 * Without old->commit, the below is the same as
544 * the two-tree unpack we already tried and failed.
545 */
546 if (!old->commit)
547 return 1;
548
549 /* Do more real merge */
550
551 /*
552 * We update the index fully, then write the
553 * tree from the index, then merge the new
554 * branch with the current tree, with the old
555 * branch as the base. Then we reset the index
556 * (but not the working tree) to the new
557 * branch, leaving the working tree as the
558 * merged version, but skipping unmerged
559 * entries in the index.
560 */
561
562 add_files_to_cache(NULL, NULL, 0);
563 /*
564 * NEEDSWORK: carrying over local changes
565 * when branches have different end-of-line
566 * normalization (or clean+smudge rules) is
567 * a pain; plumb in an option to set
568 * o.renormalize?
569 */
570 init_merge_options(&o);
571 o.verbosity = 0;
572 work = write_tree_from_memory(&o);
573
574 ret = reset_tree(new->commit->tree, opts, 1,
575 writeout_error);
576 if (ret)
577 return ret;
578 o.ancestor = old->name;
579 o.branch1 = new->name;
580 o.branch2 = "local";
581 ret = merge_trees(&o, new->commit->tree, work,
582 old->commit->tree, &result);
583 if (ret < 0)
584 exit(128);
585 ret = reset_tree(new->commit->tree, opts, 0,
586 writeout_error);
587 strbuf_release(&o.obuf);
588 if (ret)
589 return ret;
590 }
591 }
592
593 if (!active_cache_tree)
594 active_cache_tree = cache_tree();
595
596 if (!cache_tree_fully_valid(active_cache_tree))
597 cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
598
599 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
600 die(_("unable to write new index file"));
601
602 if (!opts->force && !opts->quiet)
603 show_local_changes(&new->commit->object, &opts->diff_options);
604
605 return 0;
606 }
607
608 static void report_tracking(struct branch_info *new)
609 {
610 struct strbuf sb = STRBUF_INIT;
611 struct branch *branch = branch_get(new->name);
612
613 if (!format_tracking_info(branch, &sb))
614 return;
615 fputs(sb.buf, stdout);
616 strbuf_release(&sb);
617 }
618
619 static void update_refs_for_switch(const struct checkout_opts *opts,
620 struct branch_info *old,
621 struct branch_info *new)
622 {
623 struct strbuf msg = STRBUF_INIT;
624 const char *old_desc, *reflog_msg;
625 if (opts->new_branch) {
626 if (opts->new_orphan_branch) {
627 char *refname;
628
629 refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
630 if (opts->new_branch_log &&
631 !should_autocreate_reflog(refname)) {
632 int ret;
633 struct strbuf err = STRBUF_INIT;
634
635 ret = safe_create_reflog(refname, 1, &err);
636 if (ret) {
637 fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
638 opts->new_orphan_branch, err.buf);
639 strbuf_release(&err);
640 free(refname);
641 return;
642 }
643 strbuf_release(&err);
644 }
645 free(refname);
646 }
647 else
648 create_branch(opts->new_branch, new->name,
649 opts->new_branch_force ? 1 : 0,
650 opts->new_branch_force ? 1 : 0,
651 opts->new_branch_log,
652 opts->quiet,
653 opts->track);
654 new->name = opts->new_branch;
655 setup_branch_path(new);
656 }
657
658 old_desc = old->name;
659 if (!old_desc && old->commit)
660 old_desc = oid_to_hex(&old->commit->object.oid);
661
662 reflog_msg = getenv("GIT_REFLOG_ACTION");
663 if (!reflog_msg)
664 strbuf_addf(&msg, "checkout: moving from %s to %s",
665 old_desc ? old_desc : "(invalid)", new->name);
666 else
667 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
668
669 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
670 /* Nothing to do. */
671 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
672 update_ref(msg.buf, "HEAD", &new->commit->object.oid, NULL,
673 REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
674 if (!opts->quiet) {
675 if (old->path &&
676 advice_detached_head && !opts->force_detach)
677 detach_advice(new->name);
678 describe_detached_head(_("HEAD is now at"), new->commit);
679 }
680 } else if (new->path) { /* Switch branches. */
681 if (create_symref("HEAD", new->path, msg.buf) < 0)
682 die(_("unable to update HEAD"));
683 if (!opts->quiet) {
684 if (old->path && !strcmp(new->path, old->path)) {
685 if (opts->new_branch_force)
686 fprintf(stderr, _("Reset branch '%s'\n"),
687 new->name);
688 else
689 fprintf(stderr, _("Already on '%s'\n"),
690 new->name);
691 } else if (opts->new_branch) {
692 if (opts->branch_exists)
693 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
694 else
695 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
696 } else {
697 fprintf(stderr, _("Switched to branch '%s'\n"),
698 new->name);
699 }
700 }
701 if (old->path && old->name) {
702 if (!ref_exists(old->path) && reflog_exists(old->path))
703 delete_reflog(old->path);
704 }
705 }
706 remove_branch_state();
707 strbuf_release(&msg);
708 if (!opts->quiet &&
709 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
710 report_tracking(new);
711 }
712
713 static int add_pending_uninteresting_ref(const char *refname,
714 const struct object_id *oid,
715 int flags, void *cb_data)
716 {
717 add_pending_oid(cb_data, refname, oid, UNINTERESTING);
718 return 0;
719 }
720
721 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
722 {
723 strbuf_addstr(sb, " ");
724 strbuf_add_unique_abbrev(sb, commit->object.oid.hash, DEFAULT_ABBREV);
725 strbuf_addch(sb, ' ');
726 if (!parse_commit(commit))
727 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
728 strbuf_addch(sb, '\n');
729 }
730
731 #define ORPHAN_CUTOFF 4
732 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
733 {
734 struct commit *c, *last = NULL;
735 struct strbuf sb = STRBUF_INIT;
736 int lost = 0;
737 while ((c = get_revision(revs)) != NULL) {
738 if (lost < ORPHAN_CUTOFF)
739 describe_one_orphan(&sb, c);
740 last = c;
741 lost++;
742 }
743 if (ORPHAN_CUTOFF < lost) {
744 int more = lost - ORPHAN_CUTOFF;
745 if (more == 1)
746 describe_one_orphan(&sb, last);
747 else
748 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
749 }
750
751 fprintf(stderr,
752 Q_(
753 /* The singular version */
754 "Warning: you are leaving %d commit behind, "
755 "not connected to\n"
756 "any of your branches:\n\n"
757 "%s\n",
758 /* The plural version */
759 "Warning: you are leaving %d commits behind, "
760 "not connected to\n"
761 "any of your branches:\n\n"
762 "%s\n",
763 /* Give ngettext() the count */
764 lost),
765 lost,
766 sb.buf);
767 strbuf_release(&sb);
768
769 if (advice_detached_head)
770 fprintf(stderr,
771 Q_(
772 /* The singular version */
773 "If you want to keep it by creating a new branch, "
774 "this may be a good time\nto do so with:\n\n"
775 " git branch <new-branch-name> %s\n\n",
776 /* The plural version */
777 "If you want to keep them by creating a new branch, "
778 "this may be a good time\nto do so with:\n\n"
779 " git branch <new-branch-name> %s\n\n",
780 /* Give ngettext() the count */
781 lost),
782 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV));
783 }
784
785 /*
786 * We are about to leave commit that was at the tip of a detached
787 * HEAD. If it is not reachable from any ref, this is the last chance
788 * for the user to do so without resorting to reflog.
789 */
790 static void orphaned_commit_warning(struct commit *old, struct commit *new)
791 {
792 struct rev_info revs;
793 struct object *object = &old->object;
794 struct object_array refs;
795
796 init_revisions(&revs, NULL);
797 setup_revisions(0, NULL, &revs, NULL);
798
799 object->flags &= ~UNINTERESTING;
800 add_pending_object(&revs, object, oid_to_hex(&object->oid));
801
802 for_each_ref(add_pending_uninteresting_ref, &revs);
803 add_pending_oid(&revs, "HEAD", &new->object.oid, UNINTERESTING);
804
805 /* Save pending objects, so they can be cleaned up later. */
806 refs = revs.pending;
807 revs.leak_pending = 1;
808
809 /*
810 * prepare_revision_walk (together with .leak_pending = 1) makes us
811 * the sole owner of the list of pending objects.
812 */
813 if (prepare_revision_walk(&revs))
814 die(_("internal error in revision walk"));
815 if (!(old->object.flags & UNINTERESTING))
816 suggest_reattach(old, &revs);
817 else
818 describe_detached_head(_("Previous HEAD position was"), old);
819
820 /* Clean up objects used, as they will be reused. */
821 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
822
823 object_array_clear(&refs);
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, &flag);
836 if (old.path)
837 old.commit = lookup_commit_reference_gently(&rev, 1);
838 if (!(flag & REF_ISSYMREF))
839 old.path = NULL;
840
841 if (old.path)
842 skip_prefix(old.path, "refs/heads/", &old.name);
843
844 if (!new->name) {
845 new->name = "HEAD";
846 new->commit = old.commit;
847 if (!new->commit)
848 die(_("You are on a branch yet to be born"));
849 parse_commit_or_die(new->commit);
850 }
851
852 ret = merge_working_tree(opts, &old, new, &writeout_error);
853 if (ret) {
854 free(path_to_free);
855 return ret;
856 }
857
858 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
859 orphaned_commit_warning(old.commit, new->commit);
860
861 update_refs_for_switch(opts, &old, new);
862
863 ret = post_checkout_hook(old.commit, new->commit, 1);
864 free(path_to_free);
865 return ret || writeout_error;
866 }
867
868 static int git_checkout_config(const char *var, const char *value, void *cb)
869 {
870 if (!strcmp(var, "diff.ignoresubmodules")) {
871 struct checkout_opts *opts = cb;
872 handle_ignore_submodules_arg(&opts->diff_options, value);
873 return 0;
874 }
875
876 if (starts_with(var, "submodule."))
877 return git_default_submodule_config(var, value, NULL);
878
879 return git_xmerge_config(var, value, NULL);
880 }
881
882 static int parse_branchname_arg(int argc, const char **argv,
883 int dwim_new_local_branch_ok,
884 struct branch_info *new,
885 struct checkout_opts *opts,
886 struct object_id *rev)
887 {
888 struct tree **source_tree = &opts->source_tree;
889 const char **new_branch = &opts->new_branch;
890 int argcount = 0;
891 struct object_id branch_rev;
892 const char *arg;
893 int dash_dash_pos;
894 int has_dash_dash = 0;
895 int i;
896
897 /*
898 * case 1: git checkout <ref> -- [<paths>]
899 *
900 * <ref> must be a valid tree, everything after the '--' must be
901 * a path.
902 *
903 * case 2: git checkout -- [<paths>]
904 *
905 * everything after the '--' must be paths.
906 *
907 * case 3: git checkout <something> [--]
908 *
909 * (a) If <something> is a commit, that is to
910 * switch to the branch or detach HEAD at it. As a special case,
911 * if <something> is A...B (missing A or B means HEAD but you can
912 * omit at most one side), and if there is a unique merge base
913 * between A and B, A...B names that merge base.
914 *
915 * (b) If <something> is _not_ a commit, either "--" is present
916 * or <something> is not a path, no -t or -b was given, and
917 * and there is a tracking branch whose name is <something>
918 * in one and only one remote, then this is a short-hand to
919 * fork local <something> from that remote-tracking branch.
920 *
921 * (c) Otherwise, if "--" is present, treat it like case (1).
922 *
923 * (d) Otherwise :
924 * - if it's a reference, treat it like case (1)
925 * - else if it's a path, treat it like case (2)
926 * - else: fail.
927 *
928 * case 4: git checkout <something> <paths>
929 *
930 * The first argument must not be ambiguous.
931 * - If it's *only* a reference, treat it like case (1).
932 * - If it's only a path, treat it like case (2).
933 * - else: fail.
934 *
935 */
936 if (!argc)
937 return 0;
938
939 arg = argv[0];
940 dash_dash_pos = -1;
941 for (i = 0; i < argc; i++) {
942 if (!strcmp(argv[i], "--")) {
943 dash_dash_pos = i;
944 break;
945 }
946 }
947 if (dash_dash_pos == 0)
948 return 1; /* case (2) */
949 else if (dash_dash_pos == 1)
950 has_dash_dash = 1; /* case (3) or (1) */
951 else if (dash_dash_pos >= 2)
952 die(_("only one reference expected, %d given."), dash_dash_pos);
953
954 if (!strcmp(arg, "-"))
955 arg = "@{-1}";
956
957 if (get_oid_mb(arg, rev)) {
958 /*
959 * Either case (3) or (4), with <something> not being
960 * a commit, or an attempt to use case (1) with an
961 * invalid ref.
962 *
963 * It's likely an error, but we need to find out if
964 * we should auto-create the branch, case (3).(b).
965 */
966 int recover_with_dwim = dwim_new_local_branch_ok;
967
968 if (!has_dash_dash &&
969 (check_filename(opts->prefix, arg) || !no_wildcard(arg)))
970 recover_with_dwim = 0;
971 /*
972 * Accept "git checkout foo" and "git checkout foo --"
973 * as candidates for dwim.
974 */
975 if (!(argc == 1 && !has_dash_dash) &&
976 !(argc == 2 && has_dash_dash))
977 recover_with_dwim = 0;
978
979 if (recover_with_dwim) {
980 const char *remote = unique_tracking_name(arg, rev);
981 if (remote) {
982 *new_branch = arg;
983 arg = remote;
984 /* DWIMmed to create local branch, case (3).(b) */
985 } else {
986 recover_with_dwim = 0;
987 }
988 }
989
990 if (!recover_with_dwim) {
991 if (has_dash_dash)
992 die(_("invalid reference: %s"), arg);
993 return argcount;
994 }
995 }
996
997 /* we can't end up being in (2) anymore, eat the argument */
998 argcount++;
999 argv++;
1000 argc--;
1001
1002 new->name = arg;
1003 setup_branch_path(new);
1004
1005 if (!check_refname_format(new->path, 0) &&
1006 !read_ref(new->path, &branch_rev))
1007 oidcpy(rev, &branch_rev);
1008 else
1009 new->path = NULL; /* not an existing branch */
1010
1011 new->commit = lookup_commit_reference_gently(rev, 1);
1012 if (!new->commit) {
1013 /* not a commit */
1014 *source_tree = parse_tree_indirect(rev);
1015 } else {
1016 parse_commit_or_die(new->commit);
1017 *source_tree = new->commit->tree;
1018 }
1019
1020 if (!*source_tree) /* case (1): want a tree */
1021 die(_("reference is not a tree: %s"), arg);
1022 if (!has_dash_dash) { /* case (3).(d) -> (1) */
1023 /*
1024 * Do not complain the most common case
1025 * git checkout branch
1026 * even if there happen to be a file called 'branch';
1027 * it would be extremely annoying.
1028 */
1029 if (argc)
1030 verify_non_filename(opts->prefix, arg);
1031 } else {
1032 argcount++;
1033 argv++;
1034 argc--;
1035 }
1036
1037 return argcount;
1038 }
1039
1040 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1041 {
1042 int status;
1043 struct strbuf branch_ref = STRBUF_INIT;
1044
1045 if (!opts->new_branch)
1046 die(_("You are on a branch yet to be born"));
1047 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1048 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1049 strbuf_release(&branch_ref);
1050 if (!opts->quiet)
1051 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1052 opts->new_branch);
1053 return status;
1054 }
1055
1056 static int checkout_branch(struct checkout_opts *opts,
1057 struct branch_info *new)
1058 {
1059 if (opts->pathspec.nr)
1060 die(_("paths cannot be used with switching branches"));
1061
1062 if (opts->patch_mode)
1063 die(_("'%s' cannot be used with switching branches"),
1064 "--patch");
1065
1066 if (opts->writeout_stage)
1067 die(_("'%s' cannot be used with switching branches"),
1068 "--ours/--theirs");
1069
1070 if (opts->force && opts->merge)
1071 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1072
1073 if (opts->force_detach && opts->new_branch)
1074 die(_("'%s' cannot be used with '%s'"),
1075 "--detach", "-b/-B/--orphan");
1076
1077 if (opts->new_orphan_branch) {
1078 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1079 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1080 } else if (opts->force_detach) {
1081 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1082 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1083 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1084 opts->track = git_branch_track;
1085
1086 if (new->name && !new->commit)
1087 die(_("Cannot switch branch to a non-commit '%s'"),
1088 new->name);
1089
1090 if (new->path && !opts->force_detach && !opts->new_branch &&
1091 !opts->ignore_other_worktrees) {
1092 int flag;
1093 char *head_ref = resolve_refdup("HEAD", 0, NULL, &flag);
1094 if (head_ref &&
1095 (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)))
1096 die_if_checked_out(new->path, 1);
1097 free(head_ref);
1098 }
1099
1100 if (!new->commit && opts->new_branch) {
1101 struct object_id rev;
1102 int flag;
1103
1104 if (!read_ref_full("HEAD", 0, &rev, &flag) &&
1105 (flag & REF_ISSYMREF) && is_null_oid(&rev))
1106 return switch_unborn_to_new_branch(opts);
1107 }
1108 return switch_branches(opts, new);
1109 }
1110
1111 int cmd_checkout(int argc, const char **argv, const char *prefix)
1112 {
1113 struct checkout_opts opts;
1114 struct branch_info new;
1115 char *conflict_style = NULL;
1116 int dwim_new_local_branch = 1;
1117 struct option options[] = {
1118 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1119 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1120 N_("create and checkout a new branch")),
1121 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1122 N_("create/reset and checkout a branch")),
1123 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1124 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach HEAD at named commit")),
1125 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1126 BRANCH_TRACK_EXPLICIT),
1127 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1128 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1129 2),
1130 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1131 3),
1132 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1133 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1134 OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1135 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1136 N_("conflict style (merge or diff3)")),
1137 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1138 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1139 N_("do not limit pathspecs to sparse entries only")),
1140 OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1141 N_("second guess 'git checkout <no-such-branch>'")),
1142 OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1143 N_("do not check if another worktree is holding the given ref")),
1144 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
1145 "checkout", "control recursive updating of submodules",
1146 PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
1147 OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
1148 OPT_END(),
1149 };
1150
1151 memset(&opts, 0, sizeof(opts));
1152 memset(&new, 0, sizeof(new));
1153 opts.overwrite_ignore = 1;
1154 opts.prefix = prefix;
1155 opts.show_progress = -1;
1156
1157 git_config(git_checkout_config, &opts);
1158
1159 opts.track = BRANCH_TRACK_UNSPECIFIED;
1160
1161 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1162 PARSE_OPT_KEEP_DASHDASH);
1163
1164 if (opts.show_progress < 0) {
1165 if (opts.quiet)
1166 opts.show_progress = 0;
1167 else
1168 opts.show_progress = isatty(2);
1169 }
1170
1171 if (conflict_style) {
1172 opts.merge = 1; /* implied */
1173 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1174 }
1175
1176 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1177 die(_("-b, -B and --orphan are mutually exclusive"));
1178
1179 /*
1180 * From here on, new_branch will contain the branch to be checked out,
1181 * and new_branch_force and new_orphan_branch will tell us which one of
1182 * -b/-B/--orphan is being used.
1183 */
1184 if (opts.new_branch_force)
1185 opts.new_branch = opts.new_branch_force;
1186
1187 if (opts.new_orphan_branch)
1188 opts.new_branch = opts.new_orphan_branch;
1189
1190 /* --track without -b/-B/--orphan should DWIM */
1191 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1192 const char *argv0 = argv[0];
1193 if (!argc || !strcmp(argv0, "--"))
1194 die (_("--track needs a branch name"));
1195 skip_prefix(argv0, "refs/", &argv0);
1196 skip_prefix(argv0, "remotes/", &argv0);
1197 argv0 = strchr(argv0, '/');
1198 if (!argv0 || !argv0[1])
1199 die (_("Missing branch name; try -b"));
1200 opts.new_branch = argv0 + 1;
1201 }
1202
1203 /*
1204 * Extract branch name from command line arguments, so
1205 * all that is left is pathspecs.
1206 *
1207 * Handle
1208 *
1209 * 1) git checkout <tree> -- [<paths>]
1210 * 2) git checkout -- [<paths>]
1211 * 3) git checkout <something> [<paths>]
1212 *
1213 * including "last branch" syntax and DWIM-ery for names of
1214 * remote branches, erroring out for invalid or ambiguous cases.
1215 */
1216 if (argc) {
1217 struct object_id rev;
1218 int dwim_ok =
1219 !opts.patch_mode &&
1220 dwim_new_local_branch &&
1221 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1222 !opts.new_branch;
1223 int n = parse_branchname_arg(argc, argv, dwim_ok,
1224 &new, &opts, &rev);
1225 argv += n;
1226 argc -= n;
1227 }
1228
1229 if (argc) {
1230 parse_pathspec(&opts.pathspec, 0,
1231 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1232 prefix, argv);
1233
1234 if (!opts.pathspec.nr)
1235 die(_("invalid path specification"));
1236
1237 /*
1238 * Try to give more helpful suggestion.
1239 * new_branch && argc > 1 will be caught later.
1240 */
1241 if (opts.new_branch && argc == 1)
1242 die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
1243 argv[0], opts.new_branch);
1244
1245 if (opts.force_detach)
1246 die(_("git checkout: --detach does not take a path argument '%s'"),
1247 argv[0]);
1248
1249 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1250 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1251 "checking out of the index."));
1252 }
1253
1254 if (opts.new_branch) {
1255 struct strbuf buf = STRBUF_INIT;
1256
1257 if (opts.new_branch_force)
1258 opts.branch_exists = validate_branchname(opts.new_branch, &buf);
1259 else
1260 opts.branch_exists =
1261 validate_new_branchname(opts.new_branch, &buf, 0);
1262 strbuf_release(&buf);
1263 }
1264
1265 UNLEAK(opts);
1266 if (opts.patch_mode || opts.pathspec.nr)
1267 return checkout_paths(&opts, new.name);
1268 else
1269 return checkout_branch(&opts, &new);
1270 }