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