Merge branch 'maint'
[git/git.git] / builtin / checkout.c
1 #include "builtin.h"
2 #include "lockfile.h"
3 #include "parse-options.h"
4 #include "refs.h"
5 #include "commit.h"
6 #include "tree.h"
7 #include "tree-walk.h"
8 #include "cache-tree.h"
9 #include "unpack-trees.h"
10 #include "dir.h"
11 #include "run-command.h"
12 #include "merge-recursive.h"
13 #include "branch.h"
14 #include "diff.h"
15 #include "revision.h"
16 #include "remote.h"
17 #include "blob.h"
18 #include "xdiff-interface.h"
19 #include "ll-merge.h"
20 #include "resolve-undo.h"
21 #include "submodule-config.h"
22 #include "submodule.h"
23
24 static const char * const checkout_usage[] = {
25 N_("git checkout [<options>] <branch>"),
26 N_("git checkout [<options>] [<branch>] -- <file>..."),
27 NULL,
28 };
29
30 struct checkout_opts {
31 int patch_mode;
32 int quiet;
33 int merge;
34 int force;
35 int force_detach;
36 int writeout_stage;
37 int overwrite_ignore;
38 int ignore_skipworktree;
39 int ignore_other_worktrees;
40 int show_progress;
41
42 const char *new_branch;
43 const char *new_branch_force;
44 const char *new_orphan_branch;
45 int new_branch_log;
46 enum branch_track track;
47 struct diff_options diff_options;
48
49 int branch_exists;
50 const char *prefix;
51 struct pathspec pathspec;
52 struct tree *source_tree;
53 };
54
55 static int post_checkout_hook(struct commit *old, struct commit *new,
56 int changed)
57 {
58 return run_hook_le(NULL, "post-checkout",
59 sha1_to_hex(old ? old->object.oid.hash : null_sha1),
60 sha1_to_hex(new ? new->object.oid.hash : null_sha1),
61 changed ? "1" : "0", NULL);
62 /* "new" can be NULL when checking out from the index before
63 a commit exists. */
64
65 }
66
67 static int update_some(const unsigned char *sha1, struct strbuf *base,
68 const char *pathname, unsigned mode, int stage, void *context)
69 {
70 int len;
71 struct cache_entry *ce;
72 int pos;
73
74 if (S_ISDIR(mode))
75 return READ_TREE_RECURSIVE;
76
77 len = base->len + strlen(pathname);
78 ce = xcalloc(1, cache_entry_size(len));
79 hashcpy(ce->sha1, sha1);
80 memcpy(ce->name, base->buf, base->len);
81 memcpy(ce->name + base->len, pathname, len - base->len);
82 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
83 ce->ce_namelen = len;
84 ce->ce_mode = create_ce_mode(mode);
85
86 /*
87 * If the entry is the same as the current index, we can leave the old
88 * entry in place. Whether it is UPTODATE or not, checkout_entry will
89 * do the right thing.
90 */
91 pos = cache_name_pos(ce->name, ce->ce_namelen);
92 if (pos >= 0) {
93 struct cache_entry *old = active_cache[pos];
94 if (ce->ce_mode == old->ce_mode &&
95 !hashcmp(ce->sha1, old->sha1)) {
96 old->ce_flags |= CE_UPDATE;
97 free(ce);
98 return 0;
99 }
100 }
101
102 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
103 return 0;
104 }
105
106 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
107 {
108 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
109
110 /* update the index with the given tree's info
111 * for all args, expanding wildcards, and exit
112 * with any non-zero return code.
113 */
114 return 0;
115 }
116
117 static int skip_same_name(const struct cache_entry *ce, int pos)
118 {
119 while (++pos < active_nr &&
120 !strcmp(active_cache[pos]->name, ce->name))
121 ; /* skip */
122 return pos;
123 }
124
125 static int check_stage(int stage, const struct cache_entry *ce, int pos)
126 {
127 while (pos < active_nr &&
128 !strcmp(active_cache[pos]->name, ce->name)) {
129 if (ce_stage(active_cache[pos]) == stage)
130 return 0;
131 pos++;
132 }
133 if (stage == 2)
134 return error(_("path '%s' does not have our version"), ce->name);
135 else
136 return error(_("path '%s' does not have their version"), ce->name);
137 }
138
139 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
140 {
141 unsigned seen = 0;
142 const char *name = ce->name;
143
144 while (pos < active_nr) {
145 ce = active_cache[pos];
146 if (strcmp(name, ce->name))
147 break;
148 seen |= (1 << ce_stage(ce));
149 pos++;
150 }
151 if ((stages & seen) != stages)
152 return error(_("path '%s' does not have all necessary versions"),
153 name);
154 return 0;
155 }
156
157 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
158 struct checkout *state)
159 {
160 while (pos < active_nr &&
161 !strcmp(active_cache[pos]->name, ce->name)) {
162 if (ce_stage(active_cache[pos]) == stage)
163 return checkout_entry(active_cache[pos], state, NULL);
164 pos++;
165 }
166 if (stage == 2)
167 return error(_("path '%s' does not have our version"), ce->name);
168 else
169 return error(_("path '%s' does not have their version"), ce->name);
170 }
171
172 static int checkout_merged(int pos, struct checkout *state)
173 {
174 struct cache_entry *ce = active_cache[pos];
175 const char *path = ce->name;
176 mmfile_t ancestor, ours, theirs;
177 int status;
178 unsigned char sha1[20];
179 mmbuffer_t result_buf;
180 unsigned char threeway[3][20];
181 unsigned mode = 0;
182
183 memset(threeway, 0, sizeof(threeway));
184 while (pos < active_nr) {
185 int stage;
186 stage = ce_stage(ce);
187 if (!stage || strcmp(path, ce->name))
188 break;
189 hashcpy(threeway[stage - 1], ce->sha1);
190 if (stage == 2)
191 mode = create_ce_mode(ce->ce_mode);
192 pos++;
193 ce = active_cache[pos];
194 }
195 if (is_null_sha1(threeway[1]) || is_null_sha1(threeway[2]))
196 return error(_("path '%s' does not have necessary versions"), path);
197
198 read_mmblob(&ancestor, threeway[0]);
199 read_mmblob(&ours, threeway[1]);
200 read_mmblob(&theirs, threeway[2]);
201
202 /*
203 * NEEDSWORK: re-create conflicts from merges with
204 * merge.renormalize set, too
205 */
206 status = ll_merge(&result_buf, path, &ancestor, "base",
207 &ours, "ours", &theirs, "theirs", NULL);
208 free(ancestor.ptr);
209 free(ours.ptr);
210 free(theirs.ptr);
211 if (status < 0 || !result_buf.ptr) {
212 free(result_buf.ptr);
213 return error(_("path '%s': cannot merge"), path);
214 }
215
216 /*
217 * NEEDSWORK:
218 * There is absolutely no reason to write this as a blob object
219 * and create a phony cache entry just to leak. This hack is
220 * primarily to get to the write_entry() machinery that massages
221 * the contents to work-tree format and writes out which only
222 * allows it for a cache entry. The code in write_entry() needs
223 * to be refactored to allow us to feed a <buffer, size, mode>
224 * instead of a cache entry. Such a refactoring would help
225 * merge_recursive as well (it also writes the merge result to the
226 * object database even when it may contain conflicts).
227 */
228 if (write_sha1_file(result_buf.ptr, result_buf.size,
229 blob_type, sha1))
230 die(_("Unable to add merge result for '%s'"), path);
231 ce = make_cache_entry(mode, sha1, path, 2, 0);
232 if (!ce)
233 die(_("make_cache_entry failed for path '%s'"), path);
234 status = checkout_entry(ce, state, NULL);
235 return status;
236 }
237
238 static int checkout_paths(const struct checkout_opts *opts,
239 const char *revision)
240 {
241 int pos;
242 struct checkout state;
243 static char *ps_matched;
244 unsigned char rev[20];
245 int flag;
246 struct commit *head;
247 int errs = 0;
248 struct lock_file *lock_file;
249
250 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
251 die(_("'%s' cannot be used with updating paths"), "--track");
252
253 if (opts->new_branch_log)
254 die(_("'%s' cannot be used with updating paths"), "-l");
255
256 if (opts->force && opts->patch_mode)
257 die(_("'%s' cannot be used with updating paths"), "-f");
258
259 if (opts->force_detach)
260 die(_("'%s' cannot be used with updating paths"), "--detach");
261
262 if (opts->merge && opts->patch_mode)
263 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
264
265 if (opts->force && opts->merge)
266 die(_("'%s' cannot be used with %s"), "-f", "-m");
267
268 if (opts->new_branch)
269 die(_("Cannot update paths and switch to branch '%s' at the same time."),
270 opts->new_branch);
271
272 if (opts->patch_mode)
273 return run_add_interactive(revision, "--patch=checkout",
274 &opts->pathspec);
275
276 lock_file = xcalloc(1, sizeof(struct lock_file));
277
278 hold_locked_index(lock_file, 1);
279 if (read_cache_preload(&opts->pathspec) < 0)
280 return error(_("corrupt index file"));
281
282 if (opts->source_tree)
283 read_tree_some(opts->source_tree, &opts->pathspec);
284
285 ps_matched = xcalloc(opts->pathspec.nr, 1);
286
287 /*
288 * Make sure all pathspecs participated in locating the paths
289 * to be checked out.
290 */
291 for (pos = 0; pos < active_nr; pos++) {
292 struct cache_entry *ce = active_cache[pos];
293 ce->ce_flags &= ~CE_MATCHED;
294 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
295 continue;
296 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
297 /*
298 * "git checkout tree-ish -- path", but this entry
299 * is in the original index; it will not be checked
300 * out to the working tree and it does not matter
301 * if pathspec matched this entry. We will not do
302 * anything to this entry at all.
303 */
304 continue;
305 /*
306 * Either this entry came from the tree-ish we are
307 * checking the paths out of, or we are checking out
308 * of the index.
309 *
310 * If it comes from the tree-ish, we already know it
311 * matches the pathspec and could just stamp
312 * CE_MATCHED to it from update_some(). But we still
313 * need ps_matched and read_tree_recursive (and
314 * eventually tree_entry_interesting) cannot fill
315 * ps_matched yet. Once it can, we can avoid calling
316 * match_pathspec() for _all_ entries when
317 * opts->source_tree != NULL.
318 */
319 if (ce_path_match(ce, &opts->pathspec, ps_matched))
320 ce->ce_flags |= CE_MATCHED;
321 }
322
323 if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
324 free(ps_matched);
325 return 1;
326 }
327 free(ps_matched);
328
329 /* "checkout -m path" to recreate conflicted state */
330 if (opts->merge)
331 unmerge_marked_index(&the_index);
332
333 /* Any unmerged paths? */
334 for (pos = 0; pos < active_nr; pos++) {
335 const struct cache_entry *ce = active_cache[pos];
336 if (ce->ce_flags & CE_MATCHED) {
337 if (!ce_stage(ce))
338 continue;
339 if (opts->force) {
340 warning(_("path '%s' is unmerged"), ce->name);
341 } else if (opts->writeout_stage) {
342 errs |= check_stage(opts->writeout_stage, ce, pos);
343 } else if (opts->merge) {
344 errs |= check_stages((1<<2) | (1<<3), ce, pos);
345 } else {
346 errs = 1;
347 error(_("path '%s' is unmerged"), ce->name);
348 }
349 pos = skip_same_name(ce, pos) - 1;
350 }
351 }
352 if (errs)
353 return 1;
354
355 /* Now we are committed to check them out */
356 memset(&state, 0, sizeof(state));
357 state.force = 1;
358 state.refresh_cache = 1;
359 state.istate = &the_index;
360 for (pos = 0; pos < active_nr; pos++) {
361 struct cache_entry *ce = active_cache[pos];
362 if (ce->ce_flags & CE_MATCHED) {
363 if (!ce_stage(ce)) {
364 errs |= checkout_entry(ce, &state, NULL);
365 continue;
366 }
367 if (opts->writeout_stage)
368 errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
369 else if (opts->merge)
370 errs |= checkout_merged(pos, &state);
371 pos = skip_same_name(ce, pos) - 1;
372 }
373 }
374
375 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
376 die(_("unable to write new index file"));
377
378 read_ref_full("HEAD", 0, rev, &flag);
379 head = lookup_commit_reference_gently(rev, 1);
380
381 errs |= post_checkout_hook(head, head, 0);
382 return errs;
383 }
384
385 static void show_local_changes(struct object *head,
386 const struct diff_options *opts)
387 {
388 struct rev_info rev;
389 /* I think we want full paths, even if we're in a subdirectory. */
390 init_revisions(&rev, NULL);
391 rev.diffopt.flags = opts->flags;
392 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
393 diff_setup_done(&rev.diffopt);
394 add_pending_object(&rev, head, NULL);
395 run_diff_index(&rev, 0);
396 }
397
398 static void describe_detached_head(const char *msg, struct commit *commit)
399 {
400 struct strbuf sb = STRBUF_INIT;
401 if (!parse_commit(commit))
402 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
403 fprintf(stderr, "%s %s... %s\n", msg,
404 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV), sb.buf);
405 strbuf_release(&sb);
406 }
407
408 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
409 int worktree, int *writeout_error)
410 {
411 struct unpack_trees_options opts;
412 struct tree_desc tree_desc;
413
414 memset(&opts, 0, sizeof(opts));
415 opts.head_idx = -1;
416 opts.update = worktree;
417 opts.skip_unmerged = !worktree;
418 opts.reset = 1;
419 opts.merge = 1;
420 opts.fn = oneway_merge;
421 opts.verbose_update = o->show_progress;
422 opts.src_index = &the_index;
423 opts.dst_index = &the_index;
424 parse_tree(tree);
425 init_tree_desc(&tree_desc, tree->buffer, tree->size);
426 switch (unpack_trees(1, &tree_desc, &opts)) {
427 case -2:
428 *writeout_error = 1;
429 /*
430 * We return 0 nevertheless, as the index is all right
431 * and more importantly we have made best efforts to
432 * update paths in the work tree, and we cannot revert
433 * them.
434 */
435 case 0:
436 return 0;
437 default:
438 return 128;
439 }
440 }
441
442 struct branch_info {
443 const char *name; /* The short name used */
444 const char *path; /* The full name of a real branch */
445 struct commit *commit; /* The named commit */
446 /*
447 * if not null the branch is detached because it's already
448 * checked out in this checkout
449 */
450 char *checkout;
451 };
452
453 static void setup_branch_path(struct branch_info *branch)
454 {
455 struct strbuf buf = STRBUF_INIT;
456
457 strbuf_branchname(&buf, branch->name);
458 if (strcmp(buf.buf, branch->name))
459 branch->name = xstrdup(buf.buf);
460 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
461 branch->path = strbuf_detach(&buf, NULL);
462 }
463
464 static int merge_working_tree(const struct checkout_opts *opts,
465 struct branch_info *old,
466 struct branch_info *new,
467 int *writeout_error)
468 {
469 int ret;
470 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
471
472 hold_locked_index(lock_file, 1);
473 if (read_cache_preload(NULL) < 0)
474 return error(_("corrupt index file"));
475
476 resolve_undo_clear();
477 if (opts->force) {
478 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
479 if (ret)
480 return ret;
481 } else {
482 struct tree_desc trees[2];
483 struct tree *tree;
484 struct unpack_trees_options topts;
485
486 memset(&topts, 0, sizeof(topts));
487 topts.head_idx = -1;
488 topts.src_index = &the_index;
489 topts.dst_index = &the_index;
490
491 setup_unpack_trees_porcelain(&topts, "checkout");
492
493 refresh_cache(REFRESH_QUIET);
494
495 if (unmerged_cache()) {
496 error(_("you need to resolve your current index first"));
497 return 1;
498 }
499
500 /* 2-way merge to the new branch */
501 topts.initial_checkout = is_cache_unborn();
502 topts.update = 1;
503 topts.merge = 1;
504 topts.gently = opts->merge && old->commit;
505 topts.verbose_update = opts->show_progress;
506 topts.fn = twoway_merge;
507 if (opts->overwrite_ignore) {
508 topts.dir = xcalloc(1, sizeof(*topts.dir));
509 topts.dir->flags |= DIR_SHOW_IGNORED;
510 setup_standard_excludes(topts.dir);
511 }
512 tree = parse_tree_indirect(old->commit ?
513 old->commit->object.oid.hash :
514 EMPTY_TREE_SHA1_BIN);
515 init_tree_desc(&trees[0], tree->buffer, tree->size);
516 tree = parse_tree_indirect(new->commit->object.oid.hash);
517 init_tree_desc(&trees[1], tree->buffer, tree->size);
518
519 ret = unpack_trees(2, trees, &topts);
520 if (ret == -1) {
521 /*
522 * Unpack couldn't do a trivial merge; either
523 * give up or do a real merge, depending on
524 * whether the merge flag was used.
525 */
526 struct tree *result;
527 struct tree *work;
528 struct merge_options o;
529 if (!opts->merge)
530 return 1;
531
532 /*
533 * Without old->commit, the below is the same as
534 * the two-tree unpack we already tried and failed.
535 */
536 if (!old->commit)
537 return 1;
538
539 /* Do more real merge */
540
541 /*
542 * We update the index fully, then write the
543 * tree from the index, then merge the new
544 * branch with the current tree, with the old
545 * branch as the base. Then we reset the index
546 * (but not the working tree) to the new
547 * branch, leaving the working tree as the
548 * merged version, but skipping unmerged
549 * entries in the index.
550 */
551
552 add_files_to_cache(NULL, NULL, 0);
553 /*
554 * NEEDSWORK: carrying over local changes
555 * when branches have different end-of-line
556 * normalization (or clean+smudge rules) is
557 * a pain; plumb in an option to set
558 * o.renormalize?
559 */
560 init_merge_options(&o);
561 o.verbosity = 0;
562 work = write_tree_from_memory(&o);
563
564 ret = reset_tree(new->commit->tree, opts, 1,
565 writeout_error);
566 if (ret)
567 return ret;
568 o.ancestor = old->name;
569 o.branch1 = new->name;
570 o.branch2 = "local";
571 merge_trees(&o, new->commit->tree, work,
572 old->commit->tree, &result);
573 ret = reset_tree(new->commit->tree, opts, 0,
574 writeout_error);
575 if (ret)
576 return ret;
577 }
578 }
579
580 if (!active_cache_tree)
581 active_cache_tree = cache_tree();
582
583 if (!cache_tree_fully_valid(active_cache_tree))
584 cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
585
586 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
587 die(_("unable to write new index file"));
588
589 if (!opts->force && !opts->quiet)
590 show_local_changes(&new->commit->object, &opts->diff_options);
591
592 return 0;
593 }
594
595 static void report_tracking(struct branch_info *new)
596 {
597 struct strbuf sb = STRBUF_INIT;
598 struct branch *branch = branch_get(new->name);
599
600 if (!format_tracking_info(branch, &sb))
601 return;
602 fputs(sb.buf, stdout);
603 strbuf_release(&sb);
604 }
605
606 static void update_refs_for_switch(const struct checkout_opts *opts,
607 struct branch_info *old,
608 struct branch_info *new)
609 {
610 struct strbuf msg = STRBUF_INIT;
611 const char *old_desc, *reflog_msg;
612 if (opts->new_branch) {
613 if (opts->new_orphan_branch) {
614 if (opts->new_branch_log && !log_all_ref_updates) {
615 int ret;
616 char *refname;
617 struct strbuf err = STRBUF_INIT;
618
619 refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
620 ret = safe_create_reflog(refname, 1, &err);
621 free(refname);
622 if (ret) {
623 fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
624 opts->new_orphan_branch, err.buf);
625 strbuf_release(&err);
626 return;
627 }
628 strbuf_release(&err);
629 }
630 }
631 else
632 create_branch(old->name, opts->new_branch, new->name,
633 opts->new_branch_force ? 1 : 0,
634 opts->new_branch_log,
635 opts->new_branch_force ? 1 : 0,
636 opts->quiet,
637 opts->track);
638 new->name = opts->new_branch;
639 setup_branch_path(new);
640 }
641
642 old_desc = old->name;
643 if (!old_desc && old->commit)
644 old_desc = oid_to_hex(&old->commit->object.oid);
645
646 reflog_msg = getenv("GIT_REFLOG_ACTION");
647 if (!reflog_msg)
648 strbuf_addf(&msg, "checkout: moving from %s to %s",
649 old_desc ? old_desc : "(invalid)", new->name);
650 else
651 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
652
653 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
654 /* Nothing to do. */
655 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
656 update_ref(msg.buf, "HEAD", new->commit->object.oid.hash, NULL,
657 REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
658 if (!opts->quiet) {
659 if (old->path && advice_detached_head)
660 detach_advice(new->name);
661 describe_detached_head(_("HEAD is now at"), new->commit);
662 }
663 } else if (new->path) { /* Switch branches. */
664 create_symref("HEAD", new->path, msg.buf);
665 if (!opts->quiet) {
666 if (old->path && !strcmp(new->path, old->path)) {
667 if (opts->new_branch_force)
668 fprintf(stderr, _("Reset branch '%s'\n"),
669 new->name);
670 else
671 fprintf(stderr, _("Already on '%s'\n"),
672 new->name);
673 } else if (opts->new_branch) {
674 if (opts->branch_exists)
675 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
676 else
677 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
678 } else {
679 fprintf(stderr, _("Switched to branch '%s'\n"),
680 new->name);
681 }
682 }
683 if (old->path && old->name) {
684 if (!ref_exists(old->path) && reflog_exists(old->path))
685 delete_reflog(old->path);
686 }
687 }
688 remove_branch_state();
689 strbuf_release(&msg);
690 if (!opts->quiet &&
691 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
692 report_tracking(new);
693 }
694
695 static int add_pending_uninteresting_ref(const char *refname,
696 const struct object_id *oid,
697 int flags, void *cb_data)
698 {
699 add_pending_sha1(cb_data, refname, oid->hash, UNINTERESTING);
700 return 0;
701 }
702
703 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
704 {
705 strbuf_addstr(sb, " ");
706 strbuf_addstr(sb,
707 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV));
708 strbuf_addch(sb, ' ');
709 if (!parse_commit(commit))
710 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
711 strbuf_addch(sb, '\n');
712 }
713
714 #define ORPHAN_CUTOFF 4
715 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
716 {
717 struct commit *c, *last = NULL;
718 struct strbuf sb = STRBUF_INIT;
719 int lost = 0;
720 while ((c = get_revision(revs)) != NULL) {
721 if (lost < ORPHAN_CUTOFF)
722 describe_one_orphan(&sb, c);
723 last = c;
724 lost++;
725 }
726 if (ORPHAN_CUTOFF < lost) {
727 int more = lost - ORPHAN_CUTOFF;
728 if (more == 1)
729 describe_one_orphan(&sb, last);
730 else
731 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
732 }
733
734 fprintf(stderr,
735 Q_(
736 /* The singular version */
737 "Warning: you are leaving %d commit behind, "
738 "not connected to\n"
739 "any of your branches:\n\n"
740 "%s\n",
741 /* The plural version */
742 "Warning: you are leaving %d commits behind, "
743 "not connected to\n"
744 "any of your branches:\n\n"
745 "%s\n",
746 /* Give ngettext() the count */
747 lost),
748 lost,
749 sb.buf);
750 strbuf_release(&sb);
751
752 if (advice_detached_head)
753 fprintf(stderr,
754 Q_(
755 /* The singular version */
756 "If you want to keep it by creating a new branch, "
757 "this may be a good time\nto do so with:\n\n"
758 " git branch <new-branch-name> %s\n\n",
759 /* The plural version */
760 "If you want to keep them by creating a new branch, "
761 "this may be a good time\nto do so with:\n\n"
762 " git branch <new-branch-name> %s\n\n",
763 /* Give ngettext() the count */
764 lost),
765 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV));
766 }
767
768 /*
769 * We are about to leave commit that was at the tip of a detached
770 * HEAD. If it is not reachable from any ref, this is the last chance
771 * for the user to do so without resorting to reflog.
772 */
773 static void orphaned_commit_warning(struct commit *old, struct commit *new)
774 {
775 struct rev_info revs;
776 struct object *object = &old->object;
777 struct object_array refs;
778
779 init_revisions(&revs, NULL);
780 setup_revisions(0, NULL, &revs, NULL);
781
782 object->flags &= ~UNINTERESTING;
783 add_pending_object(&revs, object, oid_to_hex(&object->oid));
784
785 for_each_ref(add_pending_uninteresting_ref, &revs);
786 add_pending_sha1(&revs, "HEAD", new->object.oid.hash, UNINTERESTING);
787
788 refs = revs.pending;
789 revs.leak_pending = 1;
790
791 if (prepare_revision_walk(&revs))
792 die(_("internal error in revision walk"));
793 if (!(old->object.flags & UNINTERESTING))
794 suggest_reattach(old, &revs);
795 else
796 describe_detached_head(_("Previous HEAD position was"), old);
797
798 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
799 free(refs.objects);
800 }
801
802 static int switch_branches(const struct checkout_opts *opts,
803 struct branch_info *new)
804 {
805 int ret = 0;
806 struct branch_info old;
807 void *path_to_free;
808 unsigned char rev[20];
809 int flag, writeout_error = 0;
810 memset(&old, 0, sizeof(old));
811 old.path = path_to_free = resolve_refdup("HEAD", 0, rev, &flag);
812 old.commit = lookup_commit_reference_gently(rev, 1);
813 if (!(flag & REF_ISSYMREF))
814 old.path = NULL;
815
816 if (old.path)
817 skip_prefix(old.path, "refs/heads/", &old.name);
818
819 if (!new->name) {
820 new->name = "HEAD";
821 new->commit = old.commit;
822 if (!new->commit)
823 die(_("You are on a branch yet to be born"));
824 parse_commit_or_die(new->commit);
825 }
826
827 ret = merge_working_tree(opts, &old, new, &writeout_error);
828 if (ret) {
829 free(path_to_free);
830 return ret;
831 }
832
833 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
834 orphaned_commit_warning(old.commit, new->commit);
835
836 update_refs_for_switch(opts, &old, new);
837
838 ret = post_checkout_hook(old.commit, new->commit, 1);
839 free(path_to_free);
840 return ret || writeout_error;
841 }
842
843 static int git_checkout_config(const char *var, const char *value, void *cb)
844 {
845 if (!strcmp(var, "diff.ignoresubmodules")) {
846 struct checkout_opts *opts = cb;
847 handle_ignore_submodules_arg(&opts->diff_options, value);
848 return 0;
849 }
850
851 if (starts_with(var, "submodule."))
852 return parse_submodule_config_option(var, value);
853
854 return git_xmerge_config(var, value, NULL);
855 }
856
857 struct tracking_name_data {
858 /* const */ char *src_ref;
859 char *dst_ref;
860 unsigned char *dst_sha1;
861 int unique;
862 };
863
864 static int check_tracking_name(struct remote *remote, void *cb_data)
865 {
866 struct tracking_name_data *cb = cb_data;
867 struct refspec query;
868 memset(&query, 0, sizeof(struct refspec));
869 query.src = cb->src_ref;
870 if (remote_find_tracking(remote, &query) ||
871 get_sha1(query.dst, cb->dst_sha1)) {
872 free(query.dst);
873 return 0;
874 }
875 if (cb->dst_ref) {
876 free(query.dst);
877 cb->unique = 0;
878 return 0;
879 }
880 cb->dst_ref = query.dst;
881 return 0;
882 }
883
884 static const char *unique_tracking_name(const char *name, unsigned char *sha1)
885 {
886 struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
887 char src_ref[PATH_MAX];
888 snprintf(src_ref, PATH_MAX, "refs/heads/%s", name);
889 cb_data.src_ref = src_ref;
890 cb_data.dst_sha1 = sha1;
891 for_each_remote(check_tracking_name, &cb_data);
892 if (cb_data.unique)
893 return cb_data.dst_ref;
894 free(cb_data.dst_ref);
895 return NULL;
896 }
897
898 static int parse_branchname_arg(int argc, const char **argv,
899 int dwim_new_local_branch_ok,
900 struct branch_info *new,
901 struct checkout_opts *opts,
902 unsigned char rev[20])
903 {
904 struct tree **source_tree = &opts->source_tree;
905 const char **new_branch = &opts->new_branch;
906 int argcount = 0;
907 unsigned char branch_rev[20];
908 const char *arg;
909 int dash_dash_pos;
910 int has_dash_dash = 0;
911 int i;
912
913 /*
914 * case 1: git checkout <ref> -- [<paths>]
915 *
916 * <ref> must be a valid tree, everything after the '--' must be
917 * a path.
918 *
919 * case 2: git checkout -- [<paths>]
920 *
921 * everything after the '--' must be paths.
922 *
923 * case 3: git checkout <something> [--]
924 *
925 * (a) If <something> is a commit, that is to
926 * switch to the branch or detach HEAD at it. As a special case,
927 * if <something> is A...B (missing A or B means HEAD but you can
928 * omit at most one side), and if there is a unique merge base
929 * between A and B, A...B names that merge base.
930 *
931 * (b) If <something> is _not_ a commit, either "--" is present
932 * or <something> is not a path, no -t or -b was given, and
933 * and there is a tracking branch whose name is <something>
934 * in one and only one remote, then this is a short-hand to
935 * fork local <something> from that remote-tracking branch.
936 *
937 * (c) Otherwise, if "--" is present, treat it like case (1).
938 *
939 * (d) Otherwise :
940 * - if it's a reference, treat it like case (1)
941 * - else if it's a path, treat it like case (2)
942 * - else: fail.
943 *
944 * case 4: git checkout <something> <paths>
945 *
946 * The first argument must not be ambiguous.
947 * - If it's *only* a reference, treat it like case (1).
948 * - If it's only a path, treat it like case (2).
949 * - else: fail.
950 *
951 */
952 if (!argc)
953 return 0;
954
955 arg = argv[0];
956 dash_dash_pos = -1;
957 for (i = 0; i < argc; i++) {
958 if (!strcmp(argv[i], "--")) {
959 dash_dash_pos = i;
960 break;
961 }
962 }
963 if (dash_dash_pos == 0)
964 return 1; /* case (2) */
965 else if (dash_dash_pos == 1)
966 has_dash_dash = 1; /* case (3) or (1) */
967 else if (dash_dash_pos >= 2)
968 die(_("only one reference expected, %d given."), dash_dash_pos);
969
970 if (!strcmp(arg, "-"))
971 arg = "@{-1}";
972
973 if (get_sha1_mb(arg, rev)) {
974 /*
975 * Either case (3) or (4), with <something> not being
976 * a commit, or an attempt to use case (1) with an
977 * invalid ref.
978 *
979 * It's likely an error, but we need to find out if
980 * we should auto-create the branch, case (3).(b).
981 */
982 int recover_with_dwim = dwim_new_local_branch_ok;
983
984 if (check_filename(NULL, arg) && !has_dash_dash)
985 recover_with_dwim = 0;
986 /*
987 * Accept "git checkout foo" and "git checkout foo --"
988 * as candidates for dwim.
989 */
990 if (!(argc == 1 && !has_dash_dash) &&
991 !(argc == 2 && has_dash_dash))
992 recover_with_dwim = 0;
993
994 if (recover_with_dwim) {
995 const char *remote = unique_tracking_name(arg, rev);
996 if (remote) {
997 *new_branch = arg;
998 arg = remote;
999 /* DWIMmed to create local branch, case (3).(b) */
1000 } else {
1001 recover_with_dwim = 0;
1002 }
1003 }
1004
1005 if (!recover_with_dwim) {
1006 if (has_dash_dash)
1007 die(_("invalid reference: %s"), arg);
1008 return argcount;
1009 }
1010 }
1011
1012 /* we can't end up being in (2) anymore, eat the argument */
1013 argcount++;
1014 argv++;
1015 argc--;
1016
1017 new->name = arg;
1018 setup_branch_path(new);
1019
1020 if (!check_refname_format(new->path, 0) &&
1021 !read_ref(new->path, branch_rev))
1022 hashcpy(rev, branch_rev);
1023 else
1024 new->path = NULL; /* not an existing branch */
1025
1026 new->commit = lookup_commit_reference_gently(rev, 1);
1027 if (!new->commit) {
1028 /* not a commit */
1029 *source_tree = parse_tree_indirect(rev);
1030 } else {
1031 parse_commit_or_die(new->commit);
1032 *source_tree = new->commit->tree;
1033 }
1034
1035 if (!*source_tree) /* case (1): want a tree */
1036 die(_("reference is not a tree: %s"), arg);
1037 if (!has_dash_dash) {/* case (3).(d) -> (1) */
1038 /*
1039 * Do not complain the most common case
1040 * git checkout branch
1041 * even if there happen to be a file called 'branch';
1042 * it would be extremely annoying.
1043 */
1044 if (argc)
1045 verify_non_filename(NULL, arg);
1046 } else {
1047 argcount++;
1048 argv++;
1049 argc--;
1050 }
1051
1052 return argcount;
1053 }
1054
1055 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1056 {
1057 int status;
1058 struct strbuf branch_ref = STRBUF_INIT;
1059
1060 if (!opts->new_branch)
1061 die(_("You are on a branch yet to be born"));
1062 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1063 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1064 strbuf_release(&branch_ref);
1065 if (!opts->quiet)
1066 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1067 opts->new_branch);
1068 return status;
1069 }
1070
1071 static int checkout_branch(struct checkout_opts *opts,
1072 struct branch_info *new)
1073 {
1074 if (opts->pathspec.nr)
1075 die(_("paths cannot be used with switching branches"));
1076
1077 if (opts->patch_mode)
1078 die(_("'%s' cannot be used with switching branches"),
1079 "--patch");
1080
1081 if (opts->writeout_stage)
1082 die(_("'%s' cannot be used with switching branches"),
1083 "--ours/--theirs");
1084
1085 if (opts->force && opts->merge)
1086 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1087
1088 if (opts->force_detach && opts->new_branch)
1089 die(_("'%s' cannot be used with '%s'"),
1090 "--detach", "-b/-B/--orphan");
1091
1092 if (opts->new_orphan_branch) {
1093 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1094 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1095 } else if (opts->force_detach) {
1096 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1097 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1098 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1099 opts->track = git_branch_track;
1100
1101 if (new->name && !new->commit)
1102 die(_("Cannot switch branch to a non-commit '%s'"),
1103 new->name);
1104
1105 if (new->path && !opts->force_detach && !opts->new_branch &&
1106 !opts->ignore_other_worktrees) {
1107 unsigned char sha1[20];
1108 int flag;
1109 char *head_ref = resolve_refdup("HEAD", 0, sha1, &flag);
1110 if (head_ref &&
1111 (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)))
1112 die_if_checked_out(new->path);
1113 free(head_ref);
1114 }
1115
1116 if (!new->commit && opts->new_branch) {
1117 unsigned char rev[20];
1118 int flag;
1119
1120 if (!read_ref_full("HEAD", 0, rev, &flag) &&
1121 (flag & REF_ISSYMREF) && is_null_sha1(rev))
1122 return switch_unborn_to_new_branch(opts);
1123 }
1124 return switch_branches(opts, new);
1125 }
1126
1127 int cmd_checkout(int argc, const char **argv, const char *prefix)
1128 {
1129 struct checkout_opts opts;
1130 struct branch_info new;
1131 char *conflict_style = NULL;
1132 int dwim_new_local_branch = 1;
1133 struct option options[] = {
1134 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1135 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1136 N_("create and checkout a new branch")),
1137 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1138 N_("create/reset and checkout a branch")),
1139 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1140 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach the HEAD at named commit")),
1141 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1142 BRANCH_TRACK_EXPLICIT),
1143 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1144 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1145 2),
1146 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1147 3),
1148 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1149 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1150 OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1151 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1152 N_("conflict style (merge or diff3)")),
1153 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1154 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1155 N_("do not limit pathspecs to sparse entries only")),
1156 OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1157 N_("second guess 'git checkout <no-such-branch>'")),
1158 OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1159 N_("do not check if another worktree is holding the given ref")),
1160 OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
1161 OPT_END(),
1162 };
1163
1164 memset(&opts, 0, sizeof(opts));
1165 memset(&new, 0, sizeof(new));
1166 opts.overwrite_ignore = 1;
1167 opts.prefix = prefix;
1168 opts.show_progress = -1;
1169
1170 gitmodules_config();
1171 git_config(git_checkout_config, &opts);
1172
1173 opts.track = BRANCH_TRACK_UNSPECIFIED;
1174
1175 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1176 PARSE_OPT_KEEP_DASHDASH);
1177
1178 if (opts.show_progress < 0) {
1179 if (opts.quiet)
1180 opts.show_progress = 0;
1181 else
1182 opts.show_progress = isatty(2);
1183 }
1184
1185 if (conflict_style) {
1186 opts.merge = 1; /* implied */
1187 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1188 }
1189
1190 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1191 die(_("-b, -B and --orphan are mutually exclusive"));
1192
1193 /*
1194 * From here on, new_branch will contain the branch to be checked out,
1195 * and new_branch_force and new_orphan_branch will tell us which one of
1196 * -b/-B/--orphan is being used.
1197 */
1198 if (opts.new_branch_force)
1199 opts.new_branch = opts.new_branch_force;
1200
1201 if (opts.new_orphan_branch)
1202 opts.new_branch = opts.new_orphan_branch;
1203
1204 /* --track without -b/-B/--orphan should DWIM */
1205 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1206 const char *argv0 = argv[0];
1207 if (!argc || !strcmp(argv0, "--"))
1208 die (_("--track needs a branch name"));
1209 skip_prefix(argv0, "refs/", &argv0);
1210 skip_prefix(argv0, "remotes/", &argv0);
1211 argv0 = strchr(argv0, '/');
1212 if (!argv0 || !argv0[1])
1213 die (_("Missing branch name; try -b"));
1214 opts.new_branch = argv0 + 1;
1215 }
1216
1217 /*
1218 * Extract branch name from command line arguments, so
1219 * all that is left is pathspecs.
1220 *
1221 * Handle
1222 *
1223 * 1) git checkout <tree> -- [<paths>]
1224 * 2) git checkout -- [<paths>]
1225 * 3) git checkout <something> [<paths>]
1226 *
1227 * including "last branch" syntax and DWIM-ery for names of
1228 * remote branches, erroring out for invalid or ambiguous cases.
1229 */
1230 if (argc) {
1231 unsigned char rev[20];
1232 int dwim_ok =
1233 !opts.patch_mode &&
1234 dwim_new_local_branch &&
1235 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1236 !opts.new_branch;
1237 int n = parse_branchname_arg(argc, argv, dwim_ok,
1238 &new, &opts, rev);
1239 argv += n;
1240 argc -= n;
1241 }
1242
1243 if (argc) {
1244 parse_pathspec(&opts.pathspec, 0,
1245 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1246 prefix, argv);
1247
1248 if (!opts.pathspec.nr)
1249 die(_("invalid path specification"));
1250
1251 /*
1252 * Try to give more helpful suggestion.
1253 * new_branch && argc > 1 will be caught later.
1254 */
1255 if (opts.new_branch && argc == 1)
1256 die(_("Cannot update paths and switch to branch '%s' at the same time.\n"
1257 "Did you intend to checkout '%s' which can not be resolved as commit?"),
1258 opts.new_branch, argv[0]);
1259
1260 if (opts.force_detach)
1261 die(_("git checkout: --detach does not take a path argument '%s'"),
1262 argv[0]);
1263
1264 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1265 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1266 "checking out of the index."));
1267 }
1268
1269 if (opts.new_branch) {
1270 struct strbuf buf = STRBUF_INIT;
1271
1272 opts.branch_exists =
1273 validate_new_branchname(opts.new_branch, &buf,
1274 !!opts.new_branch_force,
1275 !!opts.new_branch_force);
1276
1277 strbuf_release(&buf);
1278 }
1279
1280 if (opts.patch_mode || opts.pathspec.nr)
1281 return checkout_paths(&opts, new.name);
1282 else
1283 return checkout_branch(&opts, &new);
1284 }