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