Merge branch 'svn-crlf' of git://bogomips.org/git-svn into ew/svn-crlf
[git/git.git] / builtin / checkout.c
1 #include "builtin.h"
2 #include "config.h"
3 #include "lockfile.h"
4 #include "parse-options.h"
5 #include "refs.h"
6 #include "commit.h"
7 #include "tree.h"
8 #include "tree-walk.h"
9 #include "cache-tree.h"
10 #include "unpack-trees.h"
11 #include "dir.h"
12 #include "run-command.h"
13 #include "merge-recursive.h"
14 #include "branch.h"
15 #include "diff.h"
16 #include "revision.h"
17 #include "remote.h"
18 #include "blob.h"
19 #include "xdiff-interface.h"
20 #include "ll-merge.h"
21 #include "resolve-undo.h"
22 #include "submodule-config.h"
23 #include "submodule.h"
24
25 static const char * const checkout_usage[] = {
26 N_("git checkout [<options>] <branch>"),
27 N_("git checkout [<options>] [<branch>] -- <file>..."),
28 NULL,
29 };
30
31 struct checkout_opts {
32 int patch_mode;
33 int quiet;
34 int merge;
35 int force;
36 int force_detach;
37 int writeout_stage;
38 int overwrite_ignore;
39 int ignore_skipworktree;
40 int ignore_other_worktrees;
41 int show_progress;
42
43 const char *new_branch;
44 const char *new_branch_force;
45 const char *new_orphan_branch;
46 int new_branch_log;
47 enum branch_track track;
48 struct diff_options diff_options;
49
50 int branch_exists;
51 const char *prefix;
52 struct pathspec pathspec;
53 struct tree *source_tree;
54 };
55
56 static int post_checkout_hook(struct commit *old, struct commit *new,
57 int changed)
58 {
59 return run_hook_le(NULL, "post-checkout",
60 oid_to_hex(old ? &old->object.oid : &null_oid),
61 oid_to_hex(new ? &new->object.oid : &null_oid),
62 changed ? "1" : "0", NULL);
63 /* "new" can be NULL when checking out from the index before
64 a commit exists. */
65
66 }
67
68 static int update_some(const unsigned char *sha1, struct strbuf *base,
69 const char *pathname, unsigned mode, int stage, void *context)
70 {
71 int len;
72 struct cache_entry *ce;
73 int pos;
74
75 if (S_ISDIR(mode))
76 return READ_TREE_RECURSIVE;
77
78 len = base->len + strlen(pathname);
79 ce = xcalloc(1, cache_entry_size(len));
80 hashcpy(ce->oid.hash, sha1);
81 memcpy(ce->name, base->buf, base->len);
82 memcpy(ce->name + base->len, pathname, len - base->len);
83 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
84 ce->ce_namelen = len;
85 ce->ce_mode = create_ce_mode(mode);
86
87 /*
88 * If the entry is the same as the current index, we can leave the old
89 * entry in place. Whether it is UPTODATE or not, checkout_entry will
90 * do the right thing.
91 */
92 pos = cache_name_pos(ce->name, ce->ce_namelen);
93 if (pos >= 0) {
94 struct cache_entry *old = active_cache[pos];
95 if (ce->ce_mode == old->ce_mode &&
96 !oidcmp(&ce->oid, &old->oid)) {
97 old->ce_flags |= CE_UPDATE;
98 free(ce);
99 return 0;
100 }
101 }
102
103 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
104 return 0;
105 }
106
107 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
108 {
109 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
110
111 /* update the index with the given tree's info
112 * for all args, expanding wildcards, and exit
113 * with any non-zero return code.
114 */
115 return 0;
116 }
117
118 static int skip_same_name(const struct cache_entry *ce, int pos)
119 {
120 while (++pos < active_nr &&
121 !strcmp(active_cache[pos]->name, ce->name))
122 ; /* skip */
123 return pos;
124 }
125
126 static int check_stage(int stage, const struct cache_entry *ce, int pos)
127 {
128 while (pos < active_nr &&
129 !strcmp(active_cache[pos]->name, ce->name)) {
130 if (ce_stage(active_cache[pos]) == stage)
131 return 0;
132 pos++;
133 }
134 if (stage == 2)
135 return error(_("path '%s' does not have our version"), ce->name);
136 else
137 return error(_("path '%s' does not have their version"), ce->name);
138 }
139
140 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
141 {
142 unsigned seen = 0;
143 const char *name = ce->name;
144
145 while (pos < active_nr) {
146 ce = active_cache[pos];
147 if (strcmp(name, ce->name))
148 break;
149 seen |= (1 << ce_stage(ce));
150 pos++;
151 }
152 if ((stages & seen) != stages)
153 return error(_("path '%s' does not have all necessary versions"),
154 name);
155 return 0;
156 }
157
158 static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
159 const struct checkout *state)
160 {
161 while (pos < active_nr &&
162 !strcmp(active_cache[pos]->name, ce->name)) {
163 if (ce_stage(active_cache[pos]) == stage)
164 return checkout_entry(active_cache[pos], state, NULL);
165 pos++;
166 }
167 if (stage == 2)
168 return error(_("path '%s' does not have our version"), ce->name);
169 else
170 return error(_("path '%s' does not have their version"), ce->name);
171 }
172
173 static int checkout_merged(int pos, const struct checkout *state)
174 {
175 struct cache_entry *ce = active_cache[pos];
176 const char *path = ce->name;
177 mmfile_t ancestor, ours, theirs;
178 int status;
179 struct object_id oid;
180 mmbuffer_t result_buf;
181 struct object_id threeway[3];
182 unsigned mode = 0;
183
184 memset(threeway, 0, sizeof(threeway));
185 while (pos < active_nr) {
186 int stage;
187 stage = ce_stage(ce);
188 if (!stage || strcmp(path, ce->name))
189 break;
190 oidcpy(&threeway[stage - 1], &ce->oid);
191 if (stage == 2)
192 mode = create_ce_mode(ce->ce_mode);
193 pos++;
194 ce = active_cache[pos];
195 }
196 if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
197 return error(_("path '%s' does not have necessary versions"), path);
198
199 read_mmblob(&ancestor, &threeway[0]);
200 read_mmblob(&ours, &threeway[1]);
201 read_mmblob(&theirs, &threeway[2]);
202
203 /*
204 * NEEDSWORK: re-create conflicts from merges with
205 * merge.renormalize set, too
206 */
207 status = ll_merge(&result_buf, path, &ancestor, "base",
208 &ours, "ours", &theirs, "theirs", NULL);
209 free(ancestor.ptr);
210 free(ours.ptr);
211 free(theirs.ptr);
212 if (status < 0 || !result_buf.ptr) {
213 free(result_buf.ptr);
214 return error(_("path '%s': cannot merge"), path);
215 }
216
217 /*
218 * NEEDSWORK:
219 * There is absolutely no reason to write this as a blob object
220 * and create a phony cache entry. This hack is primarily to get
221 * to the write_entry() machinery that massages the contents to
222 * work-tree format and writes out which only allows it for a
223 * cache entry. The code in write_entry() needs to be refactored
224 * to allow us to feed a <buffer, size, mode> instead of a cache
225 * entry. Such a refactoring would help merge_recursive as well
226 * (it also writes the merge result to the object database even
227 * when it may contain conflicts).
228 */
229 if (write_sha1_file(result_buf.ptr, result_buf.size,
230 blob_type, oid.hash))
231 die(_("Unable to add merge result for '%s'"), path);
232 free(result_buf.ptr);
233 ce = make_cache_entry(mode, oid.hash, path, 2, 0);
234 if (!ce)
235 die(_("make_cache_entry failed for path '%s'"), path);
236 status = checkout_entry(ce, state, NULL);
237 free(ce);
238 return status;
239 }
240
241 static int checkout_paths(const struct checkout_opts *opts,
242 const char *revision)
243 {
244 int pos;
245 struct checkout state = CHECKOUT_INIT;
246 static char *ps_matched;
247 struct object_id rev;
248 struct commit *head;
249 int errs = 0;
250 struct lock_file lock_file = LOCK_INIT;
251
252 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
253 die(_("'%s' cannot be used with updating paths"), "--track");
254
255 if (opts->new_branch_log)
256 die(_("'%s' cannot be used with updating paths"), "-l");
257
258 if (opts->force && opts->patch_mode)
259 die(_("'%s' cannot be used with updating paths"), "-f");
260
261 if (opts->force_detach)
262 die(_("'%s' cannot be used with updating paths"), "--detach");
263
264 if (opts->merge && opts->patch_mode)
265 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
266
267 if (opts->force && opts->merge)
268 die(_("'%s' cannot be used with %s"), "-f", "-m");
269
270 if (opts->new_branch)
271 die(_("Cannot update paths and switch to branch '%s' at the same time."),
272 opts->new_branch);
273
274 if (opts->patch_mode)
275 return run_add_interactive(revision, "--patch=checkout",
276 &opts->pathspec);
277
278 hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
279 if (read_cache_preload(&opts->pathspec) < 0)
280 return error(_("index file corrupt"));
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 state.force = 1;
357 state.refresh_cache = 1;
358 state.istate = &the_index;
359
360 enable_delayed_checkout(&state);
361 for (pos = 0; pos < active_nr; pos++) {
362 struct cache_entry *ce = active_cache[pos];
363 if (ce->ce_flags & CE_MATCHED) {
364 if (!ce_stage(ce)) {
365 errs |= checkout_entry(ce, &state, NULL);
366 continue;
367 }
368 if (opts->writeout_stage)
369 errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
370 else if (opts->merge)
371 errs |= checkout_merged(pos, &state);
372 pos = skip_same_name(ce, pos) - 1;
373 }
374 }
375 errs |= finish_delayed_checkout(&state);
376
377 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
378 die(_("unable to write new index file"));
379
380 read_ref_full("HEAD", 0, &rev, NULL);
381 head = lookup_commit_reference_gently(&rev, 1);
382
383 errs |= post_checkout_hook(head, head, 0);
384 return errs;
385 }
386
387 static void show_local_changes(struct object *head,
388 const struct diff_options *opts)
389 {
390 struct rev_info rev;
391 /* I think we want full paths, even if we're in a subdirectory. */
392 init_revisions(&rev, NULL);
393 rev.diffopt.flags = opts->flags;
394 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
395 diff_setup_done(&rev.diffopt);
396 add_pending_object(&rev, head, NULL);
397 run_diff_index(&rev, 0);
398 }
399
400 static void describe_detached_head(const char *msg, struct commit *commit)
401 {
402 struct strbuf sb = STRBUF_INIT;
403 if (!parse_commit(commit))
404 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
405 fprintf(stderr, "%s %s... %s\n", msg,
406 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV), sb.buf);
407 strbuf_release(&sb);
408 }
409
410 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
411 int worktree, int *writeout_error)
412 {
413 struct unpack_trees_options opts;
414 struct tree_desc tree_desc;
415
416 memset(&opts, 0, sizeof(opts));
417 opts.head_idx = -1;
418 opts.update = worktree;
419 opts.skip_unmerged = !worktree;
420 opts.reset = 1;
421 opts.merge = 1;
422 opts.fn = oneway_merge;
423 opts.verbose_update = o->show_progress;
424 opts.src_index = &the_index;
425 opts.dst_index = &the_index;
426 parse_tree(tree);
427 init_tree_desc(&tree_desc, tree->buffer, tree->size);
428 switch (unpack_trees(1, &tree_desc, &opts)) {
429 case -2:
430 *writeout_error = 1;
431 /*
432 * We return 0 nevertheless, as the index is all right
433 * and more importantly we have made best efforts to
434 * update paths in the work tree, and we cannot revert
435 * them.
436 */
437 /* fallthrough */
438 case 0:
439 return 0;
440 default:
441 return 128;
442 }
443 }
444
445 struct branch_info {
446 const char *name; /* The short name used */
447 const char *path; /* The full name of a real branch */
448 struct commit *commit; /* The named commit */
449 /*
450 * if not null the branch is detached because it's already
451 * checked out in this checkout
452 */
453 char *checkout;
454 };
455
456 static void setup_branch_path(struct branch_info *branch)
457 {
458 struct strbuf buf = STRBUF_INIT;
459
460 strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
461 if (strcmp(buf.buf, branch->name))
462 branch->name = xstrdup(buf.buf);
463 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
464 branch->path = strbuf_detach(&buf, NULL);
465 }
466
467 static int merge_working_tree(const struct checkout_opts *opts,
468 struct branch_info *old,
469 struct branch_info *new,
470 int *writeout_error)
471 {
472 int ret;
473 struct lock_file lock_file = LOCK_INIT;
474
475 hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
476 if (read_cache_preload(NULL) < 0)
477 return error(_("index file corrupt"));
478
479 resolve_undo_clear();
480 if (opts->force) {
481 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
482 if (ret)
483 return ret;
484 } else {
485 struct tree_desc trees[2];
486 struct tree *tree;
487 struct unpack_trees_options topts;
488
489 memset(&topts, 0, sizeof(topts));
490 topts.head_idx = -1;
491 topts.src_index = &the_index;
492 topts.dst_index = &the_index;
493
494 setup_unpack_trees_porcelain(&topts, "checkout");
495
496 refresh_cache(REFRESH_QUIET);
497
498 if (unmerged_cache()) {
499 error(_("you need to resolve your current index first"));
500 return 1;
501 }
502
503 /* 2-way merge to the new branch */
504 topts.initial_checkout = is_cache_unborn();
505 topts.update = 1;
506 topts.merge = 1;
507 topts.gently = opts->merge && old->commit;
508 topts.verbose_update = opts->show_progress;
509 topts.fn = twoway_merge;
510 if (opts->overwrite_ignore) {
511 topts.dir = xcalloc(1, sizeof(*topts.dir));
512 topts.dir->flags |= DIR_SHOW_IGNORED;
513 setup_standard_excludes(topts.dir);
514 }
515 tree = parse_tree_indirect(old->commit ?
516 &old->commit->object.oid :
517 the_hash_algo->empty_tree);
518 init_tree_desc(&trees[0], tree->buffer, tree->size);
519 tree = parse_tree_indirect(&new->commit->object.oid);
520 init_tree_desc(&trees[1], tree->buffer, tree->size);
521
522 ret = unpack_trees(2, trees, &topts);
523 if (ret == -1) {
524 /*
525 * Unpack couldn't do a trivial merge; either
526 * give up or do a real merge, depending on
527 * whether the merge flag was used.
528 */
529 struct tree *result;
530 struct tree *work;
531 struct merge_options o;
532 if (!opts->merge)
533 return 1;
534
535 /*
536 * Without old->commit, the below is the same as
537 * the two-tree unpack we already tried and failed.
538 */
539 if (!old->commit)
540 return 1;
541
542 /* Do more real merge */
543
544 /*
545 * We update the index fully, then write the
546 * tree from the index, then merge the new
547 * branch with the current tree, with the old
548 * branch as the base. Then we reset the index
549 * (but not the working tree) to the new
550 * branch, leaving the working tree as the
551 * merged version, but skipping unmerged
552 * entries in the index.
553 */
554
555 add_files_to_cache(NULL, NULL, 0);
556 /*
557 * NEEDSWORK: carrying over local changes
558 * when branches have different end-of-line
559 * normalization (or clean+smudge rules) is
560 * a pain; plumb in an option to set
561 * o.renormalize?
562 */
563 init_merge_options(&o);
564 o.verbosity = 0;
565 work = write_tree_from_memory(&o);
566
567 ret = reset_tree(new->commit->tree, opts, 1,
568 writeout_error);
569 if (ret)
570 return ret;
571 o.ancestor = old->name;
572 o.branch1 = new->name;
573 o.branch2 = "local";
574 ret = merge_trees(&o, new->commit->tree, work,
575 old->commit->tree, &result);
576 if (ret < 0)
577 exit(128);
578 ret = reset_tree(new->commit->tree, opts, 0,
579 writeout_error);
580 strbuf_release(&o.obuf);
581 if (ret)
582 return ret;
583 }
584 }
585
586 if (!active_cache_tree)
587 active_cache_tree = cache_tree();
588
589 if (!cache_tree_fully_valid(active_cache_tree))
590 cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
591
592 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
593 die(_("unable to write new index file"));
594
595 if (!opts->force && !opts->quiet)
596 show_local_changes(&new->commit->object, &opts->diff_options);
597
598 return 0;
599 }
600
601 static void report_tracking(struct branch_info *new)
602 {
603 struct strbuf sb = STRBUF_INIT;
604 struct branch *branch = branch_get(new->name);
605
606 if (!format_tracking_info(branch, &sb))
607 return;
608 fputs(sb.buf, stdout);
609 strbuf_release(&sb);
610 }
611
612 static void update_refs_for_switch(const struct checkout_opts *opts,
613 struct branch_info *old,
614 struct branch_info *new)
615 {
616 struct strbuf msg = STRBUF_INIT;
617 const char *old_desc, *reflog_msg;
618 if (opts->new_branch) {
619 if (opts->new_orphan_branch) {
620 char *refname;
621
622 refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
623 if (opts->new_branch_log &&
624 !should_autocreate_reflog(refname)) {
625 int ret;
626 struct strbuf err = STRBUF_INIT;
627
628 ret = safe_create_reflog(refname, 1, &err);
629 if (ret) {
630 fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
631 opts->new_orphan_branch, err.buf);
632 strbuf_release(&err);
633 free(refname);
634 return;
635 }
636 strbuf_release(&err);
637 }
638 free(refname);
639 }
640 else
641 create_branch(opts->new_branch, new->name,
642 opts->new_branch_force ? 1 : 0,
643 opts->new_branch_log,
644 opts->new_branch_force ? 1 : 0,
645 opts->quiet,
646 opts->track);
647 new->name = opts->new_branch;
648 setup_branch_path(new);
649 }
650
651 old_desc = old->name;
652 if (!old_desc && old->commit)
653 old_desc = oid_to_hex(&old->commit->object.oid);
654
655 reflog_msg = getenv("GIT_REFLOG_ACTION");
656 if (!reflog_msg)
657 strbuf_addf(&msg, "checkout: moving from %s to %s",
658 old_desc ? old_desc : "(invalid)", new->name);
659 else
660 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
661
662 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
663 /* Nothing to do. */
664 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
665 update_ref(msg.buf, "HEAD", &new->commit->object.oid, NULL,
666 REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
667 if (!opts->quiet) {
668 if (old->path &&
669 advice_detached_head && !opts->force_detach)
670 detach_advice(new->name);
671 describe_detached_head(_("HEAD is now at"), new->commit);
672 }
673 } else if (new->path) { /* Switch branches. */
674 if (create_symref("HEAD", new->path, msg.buf) < 0)
675 die(_("unable to update HEAD"));
676 if (!opts->quiet) {
677 if (old->path && !strcmp(new->path, old->path)) {
678 if (opts->new_branch_force)
679 fprintf(stderr, _("Reset branch '%s'\n"),
680 new->name);
681 else
682 fprintf(stderr, _("Already on '%s'\n"),
683 new->name);
684 } else if (opts->new_branch) {
685 if (opts->branch_exists)
686 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
687 else
688 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
689 } else {
690 fprintf(stderr, _("Switched to branch '%s'\n"),
691 new->name);
692 }
693 }
694 if (old->path && old->name) {
695 if (!ref_exists(old->path) && reflog_exists(old->path))
696 delete_reflog(old->path);
697 }
698 }
699 remove_branch_state();
700 strbuf_release(&msg);
701 if (!opts->quiet &&
702 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
703 report_tracking(new);
704 }
705
706 static int add_pending_uninteresting_ref(const char *refname,
707 const struct object_id *oid,
708 int flags, void *cb_data)
709 {
710 add_pending_oid(cb_data, refname, oid, UNINTERESTING);
711 return 0;
712 }
713
714 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
715 {
716 strbuf_addstr(sb, " ");
717 strbuf_add_unique_abbrev(sb, commit->object.oid.hash, DEFAULT_ABBREV);
718 strbuf_addch(sb, ' ');
719 if (!parse_commit(commit))
720 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
721 strbuf_addch(sb, '\n');
722 }
723
724 #define ORPHAN_CUTOFF 4
725 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
726 {
727 struct commit *c, *last = NULL;
728 struct strbuf sb = STRBUF_INIT;
729 int lost = 0;
730 while ((c = get_revision(revs)) != NULL) {
731 if (lost < ORPHAN_CUTOFF)
732 describe_one_orphan(&sb, c);
733 last = c;
734 lost++;
735 }
736 if (ORPHAN_CUTOFF < lost) {
737 int more = lost - ORPHAN_CUTOFF;
738 if (more == 1)
739 describe_one_orphan(&sb, last);
740 else
741 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
742 }
743
744 fprintf(stderr,
745 Q_(
746 /* The singular version */
747 "Warning: you are leaving %d commit behind, "
748 "not connected to\n"
749 "any of your branches:\n\n"
750 "%s\n",
751 /* The plural version */
752 "Warning: you are leaving %d commits behind, "
753 "not connected to\n"
754 "any of your branches:\n\n"
755 "%s\n",
756 /* Give ngettext() the count */
757 lost),
758 lost,
759 sb.buf);
760 strbuf_release(&sb);
761
762 if (advice_detached_head)
763 fprintf(stderr,
764 Q_(
765 /* The singular version */
766 "If you want to keep it by creating a new branch, "
767 "this may be a good time\nto do so with:\n\n"
768 " git branch <new-branch-name> %s\n\n",
769 /* The plural version */
770 "If you want to keep them by creating a new branch, "
771 "this may be a good time\nto do so with:\n\n"
772 " git branch <new-branch-name> %s\n\n",
773 /* Give ngettext() the count */
774 lost),
775 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV));
776 }
777
778 /*
779 * We are about to leave commit that was at the tip of a detached
780 * HEAD. If it is not reachable from any ref, this is the last chance
781 * for the user to do so without resorting to reflog.
782 */
783 static void orphaned_commit_warning(struct commit *old, struct commit *new)
784 {
785 struct rev_info revs;
786 struct object *object = &old->object;
787 struct object_array refs;
788
789 init_revisions(&revs, NULL);
790 setup_revisions(0, NULL, &revs, NULL);
791
792 object->flags &= ~UNINTERESTING;
793 add_pending_object(&revs, object, oid_to_hex(&object->oid));
794
795 for_each_ref(add_pending_uninteresting_ref, &revs);
796 add_pending_oid(&revs, "HEAD", &new->object.oid, UNINTERESTING);
797
798 /* Save pending objects, so they can be cleaned up later. */
799 refs = revs.pending;
800 revs.leak_pending = 1;
801
802 /*
803 * prepare_revision_walk (together with .leak_pending = 1) makes us
804 * the sole owner of the list of pending objects.
805 */
806 if (prepare_revision_walk(&revs))
807 die(_("internal error in revision walk"));
808 if (!(old->object.flags & UNINTERESTING))
809 suggest_reattach(old, &revs);
810 else
811 describe_detached_head(_("Previous HEAD position was"), old);
812
813 /* Clean up objects used, as they will be reused. */
814 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
815
816 object_array_clear(&refs);
817 }
818
819 static int switch_branches(const struct checkout_opts *opts,
820 struct branch_info *new)
821 {
822 int ret = 0;
823 struct branch_info old;
824 void *path_to_free;
825 struct object_id rev;
826 int flag, writeout_error = 0;
827 memset(&old, 0, sizeof(old));
828 old.path = path_to_free = resolve_refdup("HEAD", 0, &rev, &flag);
829 if (old.path)
830 old.commit = lookup_commit_reference_gently(&rev, 1);
831 if (!(flag & REF_ISSYMREF))
832 old.path = NULL;
833
834 if (old.path)
835 skip_prefix(old.path, "refs/heads/", &old.name);
836
837 if (!new->name) {
838 new->name = "HEAD";
839 new->commit = old.commit;
840 if (!new->commit)
841 die(_("You are on a branch yet to be born"));
842 parse_commit_or_die(new->commit);
843 }
844
845 ret = merge_working_tree(opts, &old, new, &writeout_error);
846 if (ret) {
847 free(path_to_free);
848 return ret;
849 }
850
851 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
852 orphaned_commit_warning(old.commit, new->commit);
853
854 update_refs_for_switch(opts, &old, new);
855
856 ret = post_checkout_hook(old.commit, new->commit, 1);
857 free(path_to_free);
858 return ret || writeout_error;
859 }
860
861 static int git_checkout_config(const char *var, const char *value, void *cb)
862 {
863 if (!strcmp(var, "diff.ignoresubmodules")) {
864 struct checkout_opts *opts = cb;
865 handle_ignore_submodules_arg(&opts->diff_options, value);
866 return 0;
867 }
868
869 if (starts_with(var, "submodule."))
870 return git_default_submodule_config(var, value, NULL);
871
872 return git_xmerge_config(var, value, NULL);
873 }
874
875 struct tracking_name_data {
876 /* const */ char *src_ref;
877 char *dst_ref;
878 struct object_id *dst_oid;
879 int unique;
880 };
881
882 static int check_tracking_name(struct remote *remote, void *cb_data)
883 {
884 struct tracking_name_data *cb = cb_data;
885 struct refspec query;
886 memset(&query, 0, sizeof(struct refspec));
887 query.src = cb->src_ref;
888 if (remote_find_tracking(remote, &query) ||
889 get_oid(query.dst, cb->dst_oid)) {
890 free(query.dst);
891 return 0;
892 }
893 if (cb->dst_ref) {
894 free(query.dst);
895 cb->unique = 0;
896 return 0;
897 }
898 cb->dst_ref = query.dst;
899 return 0;
900 }
901
902 static const char *unique_tracking_name(const char *name, struct object_id *oid)
903 {
904 struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
905 cb_data.src_ref = xstrfmt("refs/heads/%s", name);
906 cb_data.dst_oid = oid;
907 for_each_remote(check_tracking_name, &cb_data);
908 free(cb_data.src_ref);
909 if (cb_data.unique)
910 return cb_data.dst_ref;
911 free(cb_data.dst_ref);
912 return NULL;
913 }
914
915 static int parse_branchname_arg(int argc, const char **argv,
916 int dwim_new_local_branch_ok,
917 struct branch_info *new,
918 struct checkout_opts *opts,
919 struct object_id *rev)
920 {
921 struct tree **source_tree = &opts->source_tree;
922 const char **new_branch = &opts->new_branch;
923 int argcount = 0;
924 struct object_id branch_rev;
925 const char *arg;
926 int dash_dash_pos;
927 int has_dash_dash = 0;
928 int i;
929
930 /*
931 * case 1: git checkout <ref> -- [<paths>]
932 *
933 * <ref> must be a valid tree, everything after the '--' must be
934 * a path.
935 *
936 * case 2: git checkout -- [<paths>]
937 *
938 * everything after the '--' must be paths.
939 *
940 * case 3: git checkout <something> [--]
941 *
942 * (a) If <something> is a commit, that is to
943 * switch to the branch or detach HEAD at it. As a special case,
944 * if <something> is A...B (missing A or B means HEAD but you can
945 * omit at most one side), and if there is a unique merge base
946 * between A and B, A...B names that merge base.
947 *
948 * (b) If <something> is _not_ a commit, either "--" is present
949 * or <something> is not a path, no -t or -b was given, and
950 * and there is a tracking branch whose name is <something>
951 * in one and only one remote, then this is a short-hand to
952 * fork local <something> from that remote-tracking branch.
953 *
954 * (c) Otherwise, if "--" is present, treat it like case (1).
955 *
956 * (d) Otherwise :
957 * - if it's a reference, treat it like case (1)
958 * - else if it's a path, treat it like case (2)
959 * - else: fail.
960 *
961 * case 4: git checkout <something> <paths>
962 *
963 * The first argument must not be ambiguous.
964 * - If it's *only* a reference, treat it like case (1).
965 * - If it's only a path, treat it like case (2).
966 * - else: fail.
967 *
968 */
969 if (!argc)
970 return 0;
971
972 arg = argv[0];
973 dash_dash_pos = -1;
974 for (i = 0; i < argc; i++) {
975 if (!strcmp(argv[i], "--")) {
976 dash_dash_pos = i;
977 break;
978 }
979 }
980 if (dash_dash_pos == 0)
981 return 1; /* case (2) */
982 else if (dash_dash_pos == 1)
983 has_dash_dash = 1; /* case (3) or (1) */
984 else if (dash_dash_pos >= 2)
985 die(_("only one reference expected, %d given."), dash_dash_pos);
986
987 if (!strcmp(arg, "-"))
988 arg = "@{-1}";
989
990 if (get_oid_mb(arg, rev)) {
991 /*
992 * Either case (3) or (4), with <something> not being
993 * a commit, or an attempt to use case (1) with an
994 * invalid ref.
995 *
996 * It's likely an error, but we need to find out if
997 * we should auto-create the branch, case (3).(b).
998 */
999 int recover_with_dwim = dwim_new_local_branch_ok;
1000
1001 if (!has_dash_dash &&
1002 (check_filename(opts->prefix, arg) || !no_wildcard(arg)))
1003 recover_with_dwim = 0;
1004 /*
1005 * Accept "git checkout foo" and "git checkout foo --"
1006 * as candidates for dwim.
1007 */
1008 if (!(argc == 1 && !has_dash_dash) &&
1009 !(argc == 2 && has_dash_dash))
1010 recover_with_dwim = 0;
1011
1012 if (recover_with_dwim) {
1013 const char *remote = unique_tracking_name(arg, rev);
1014 if (remote) {
1015 *new_branch = arg;
1016 arg = remote;
1017 /* DWIMmed to create local branch, case (3).(b) */
1018 } else {
1019 recover_with_dwim = 0;
1020 }
1021 }
1022
1023 if (!recover_with_dwim) {
1024 if (has_dash_dash)
1025 die(_("invalid reference: %s"), arg);
1026 return argcount;
1027 }
1028 }
1029
1030 /* we can't end up being in (2) anymore, eat the argument */
1031 argcount++;
1032 argv++;
1033 argc--;
1034
1035 new->name = arg;
1036 setup_branch_path(new);
1037
1038 if (!check_refname_format(new->path, 0) &&
1039 !read_ref(new->path, &branch_rev))
1040 oidcpy(rev, &branch_rev);
1041 else
1042 new->path = NULL; /* not an existing branch */
1043
1044 new->commit = lookup_commit_reference_gently(rev, 1);
1045 if (!new->commit) {
1046 /* not a commit */
1047 *source_tree = parse_tree_indirect(rev);
1048 } else {
1049 parse_commit_or_die(new->commit);
1050 *source_tree = new->commit->tree;
1051 }
1052
1053 if (!*source_tree) /* case (1): want a tree */
1054 die(_("reference is not a tree: %s"), arg);
1055 if (!has_dash_dash) { /* case (3).(d) -> (1) */
1056 /*
1057 * Do not complain the most common case
1058 * git checkout branch
1059 * even if there happen to be a file called 'branch';
1060 * it would be extremely annoying.
1061 */
1062 if (argc)
1063 verify_non_filename(opts->prefix, arg);
1064 } else {
1065 argcount++;
1066 argv++;
1067 argc--;
1068 }
1069
1070 return argcount;
1071 }
1072
1073 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1074 {
1075 int status;
1076 struct strbuf branch_ref = STRBUF_INIT;
1077
1078 if (!opts->new_branch)
1079 die(_("You are on a branch yet to be born"));
1080 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1081 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1082 strbuf_release(&branch_ref);
1083 if (!opts->quiet)
1084 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1085 opts->new_branch);
1086 return status;
1087 }
1088
1089 static int checkout_branch(struct checkout_opts *opts,
1090 struct branch_info *new)
1091 {
1092 if (opts->pathspec.nr)
1093 die(_("paths cannot be used with switching branches"));
1094
1095 if (opts->patch_mode)
1096 die(_("'%s' cannot be used with switching branches"),
1097 "--patch");
1098
1099 if (opts->writeout_stage)
1100 die(_("'%s' cannot be used with switching branches"),
1101 "--ours/--theirs");
1102
1103 if (opts->force && opts->merge)
1104 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1105
1106 if (opts->force_detach && opts->new_branch)
1107 die(_("'%s' cannot be used with '%s'"),
1108 "--detach", "-b/-B/--orphan");
1109
1110 if (opts->new_orphan_branch) {
1111 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1112 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1113 } else if (opts->force_detach) {
1114 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1115 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1116 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1117 opts->track = git_branch_track;
1118
1119 if (new->name && !new->commit)
1120 die(_("Cannot switch branch to a non-commit '%s'"),
1121 new->name);
1122
1123 if (new->path && !opts->force_detach && !opts->new_branch &&
1124 !opts->ignore_other_worktrees) {
1125 int flag;
1126 char *head_ref = resolve_refdup("HEAD", 0, NULL, &flag);
1127 if (head_ref &&
1128 (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)))
1129 die_if_checked_out(new->path, 1);
1130 free(head_ref);
1131 }
1132
1133 if (!new->commit && opts->new_branch) {
1134 struct object_id rev;
1135 int flag;
1136
1137 if (!read_ref_full("HEAD", 0, &rev, &flag) &&
1138 (flag & REF_ISSYMREF) && is_null_oid(&rev))
1139 return switch_unborn_to_new_branch(opts);
1140 }
1141 return switch_branches(opts, new);
1142 }
1143
1144 int cmd_checkout(int argc, const char **argv, const char *prefix)
1145 {
1146 struct checkout_opts opts;
1147 struct branch_info new;
1148 char *conflict_style = NULL;
1149 int dwim_new_local_branch = 1;
1150 struct option options[] = {
1151 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1152 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1153 N_("create and checkout a new branch")),
1154 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1155 N_("create/reset and checkout a branch")),
1156 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1157 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach HEAD at named commit")),
1158 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1159 BRANCH_TRACK_EXPLICIT),
1160 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1161 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1162 2),
1163 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1164 3),
1165 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1166 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1167 OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1168 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1169 N_("conflict style (merge or diff3)")),
1170 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1171 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1172 N_("do not limit pathspecs to sparse entries only")),
1173 OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1174 N_("second guess 'git checkout <no-such-branch>'")),
1175 OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1176 N_("do not check if another worktree is holding the given ref")),
1177 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
1178 "checkout", "control recursive updating of submodules",
1179 PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
1180 OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
1181 OPT_END(),
1182 };
1183
1184 memset(&opts, 0, sizeof(opts));
1185 memset(&new, 0, sizeof(new));
1186 opts.overwrite_ignore = 1;
1187 opts.prefix = prefix;
1188 opts.show_progress = -1;
1189
1190 git_config(git_checkout_config, &opts);
1191
1192 opts.track = BRANCH_TRACK_UNSPECIFIED;
1193
1194 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1195 PARSE_OPT_KEEP_DASHDASH);
1196
1197 if (opts.show_progress < 0) {
1198 if (opts.quiet)
1199 opts.show_progress = 0;
1200 else
1201 opts.show_progress = isatty(2);
1202 }
1203
1204 if (conflict_style) {
1205 opts.merge = 1; /* implied */
1206 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1207 }
1208
1209 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1210 die(_("-b, -B and --orphan are mutually exclusive"));
1211
1212 /*
1213 * From here on, new_branch will contain the branch to be checked out,
1214 * and new_branch_force and new_orphan_branch will tell us which one of
1215 * -b/-B/--orphan is being used.
1216 */
1217 if (opts.new_branch_force)
1218 opts.new_branch = opts.new_branch_force;
1219
1220 if (opts.new_orphan_branch)
1221 opts.new_branch = opts.new_orphan_branch;
1222
1223 /* --track without -b/-B/--orphan should DWIM */
1224 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1225 const char *argv0 = argv[0];
1226 if (!argc || !strcmp(argv0, "--"))
1227 die (_("--track needs a branch name"));
1228 skip_prefix(argv0, "refs/", &argv0);
1229 skip_prefix(argv0, "remotes/", &argv0);
1230 argv0 = strchr(argv0, '/');
1231 if (!argv0 || !argv0[1])
1232 die (_("Missing branch name; try -b"));
1233 opts.new_branch = argv0 + 1;
1234 }
1235
1236 /*
1237 * Extract branch name from command line arguments, so
1238 * all that is left is pathspecs.
1239 *
1240 * Handle
1241 *
1242 * 1) git checkout <tree> -- [<paths>]
1243 * 2) git checkout -- [<paths>]
1244 * 3) git checkout <something> [<paths>]
1245 *
1246 * including "last branch" syntax and DWIM-ery for names of
1247 * remote branches, erroring out for invalid or ambiguous cases.
1248 */
1249 if (argc) {
1250 struct object_id rev;
1251 int dwim_ok =
1252 !opts.patch_mode &&
1253 dwim_new_local_branch &&
1254 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1255 !opts.new_branch;
1256 int n = parse_branchname_arg(argc, argv, dwim_ok,
1257 &new, &opts, &rev);
1258 argv += n;
1259 argc -= n;
1260 }
1261
1262 if (argc) {
1263 parse_pathspec(&opts.pathspec, 0,
1264 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1265 prefix, argv);
1266
1267 if (!opts.pathspec.nr)
1268 die(_("invalid path specification"));
1269
1270 /*
1271 * Try to give more helpful suggestion.
1272 * new_branch && argc > 1 will be caught later.
1273 */
1274 if (opts.new_branch && argc == 1)
1275 die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
1276 argv[0], opts.new_branch);
1277
1278 if (opts.force_detach)
1279 die(_("git checkout: --detach does not take a path argument '%s'"),
1280 argv[0]);
1281
1282 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1283 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1284 "checking out of the index."));
1285 }
1286
1287 if (opts.new_branch) {
1288 struct strbuf buf = STRBUF_INIT;
1289
1290 if (opts.new_branch_force)
1291 opts.branch_exists = validate_branchname(opts.new_branch, &buf);
1292 else
1293 opts.branch_exists =
1294 validate_new_branchname(opts.new_branch, &buf, 0);
1295 strbuf_release(&buf);
1296 }
1297
1298 UNLEAK(opts);
1299 if (opts.patch_mode || opts.pathspec.nr)
1300 return checkout_paths(&opts, new.name);
1301 else
1302 return checkout_branch(&opts, &new);
1303 }