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