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