create_branch: drop unused "head" parameter
[git/git.git] / builtin / checkout.c
1 #include "builtin.h"
2 #include "lockfile.h"
3 #include "parse-options.h"
4 #include "refs.h"
5 #include "commit.h"
6 #include "tree.h"
7 #include "tree-walk.h"
8 #include "cache-tree.h"
9 #include "unpack-trees.h"
10 #include "dir.h"
11 #include "run-command.h"
12 #include "merge-recursive.h"
13 #include "branch.h"
14 #include "diff.h"
15 #include "revision.h"
16 #include "remote.h"
17 #include "blob.h"
18 #include "xdiff-interface.h"
19 #include "ll-merge.h"
20 #include "resolve-undo.h"
21 #include "submodule-config.h"
22 #include "submodule.h"
23
24 static const char * const checkout_usage[] = {
25 N_("git checkout [<options>] <branch>"),
26 N_("git checkout [<options>] [<branch>] -- <file>..."),
27 NULL,
28 };
29
30 struct checkout_opts {
31 int patch_mode;
32 int quiet;
33 int merge;
34 int force;
35 int force_detach;
36 int writeout_stage;
37 int overwrite_ignore;
38 int ignore_skipworktree;
39 int ignore_other_worktrees;
40 int show_progress;
41
42 const char *new_branch;
43 const char *new_branch_force;
44 const char *new_orphan_branch;
45 int new_branch_log;
46 enum branch_track track;
47 struct diff_options diff_options;
48
49 int branch_exists;
50 const char *prefix;
51 struct pathspec pathspec;
52 struct tree *source_tree;
53 };
54
55 static int post_checkout_hook(struct commit *old, struct commit *new,
56 int changed)
57 {
58 return run_hook_le(NULL, "post-checkout",
59 sha1_to_hex(old ? old->object.oid.hash : null_sha1),
60 sha1_to_hex(new ? new->object.oid.hash : null_sha1),
61 changed ? "1" : "0", NULL);
62 /* "new" can be NULL when checking out from the index before
63 a commit exists. */
64
65 }
66
67 static int update_some(const unsigned char *sha1, struct strbuf *base,
68 const char *pathname, unsigned mode, int stage, void *context)
69 {
70 int len;
71 struct cache_entry *ce;
72 int pos;
73
74 if (S_ISDIR(mode))
75 return READ_TREE_RECURSIVE;
76
77 len = base->len + strlen(pathname);
78 ce = xcalloc(1, cache_entry_size(len));
79 hashcpy(ce->sha1, sha1);
80 memcpy(ce->name, base->buf, base->len);
81 memcpy(ce->name + base->len, pathname, len - base->len);
82 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
83 ce->ce_namelen = len;
84 ce->ce_mode = create_ce_mode(mode);
85
86 /*
87 * If the entry is the same as the current index, we can leave the old
88 * entry in place. Whether it is UPTODATE or not, checkout_entry will
89 * do the right thing.
90 */
91 pos = cache_name_pos(ce->name, ce->ce_namelen);
92 if (pos >= 0) {
93 struct cache_entry *old = active_cache[pos];
94 if (ce->ce_mode == old->ce_mode &&
95 !hashcmp(ce->sha1, old->sha1)) {
96 old->ce_flags |= CE_UPDATE;
97 free(ce);
98 return 0;
99 }
100 }
101
102 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
103 return 0;
104 }
105
106 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
107 {
108 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
109
110 /* update the index with the given tree's info
111 * for all args, expanding wildcards, and exit
112 * with any non-zero return code.
113 */
114 return 0;
115 }
116
117 static int skip_same_name(const struct cache_entry *ce, int pos)
118 {
119 while (++pos < active_nr &&
120 !strcmp(active_cache[pos]->name, ce->name))
121 ; /* skip */
122 return pos;
123 }
124
125 static int check_stage(int stage, const struct cache_entry *ce, int pos)
126 {
127 while (pos < active_nr &&
128 !strcmp(active_cache[pos]->name, ce->name)) {
129 if (ce_stage(active_cache[pos]) == stage)
130 return 0;
131 pos++;
132 }
133 if (stage == 2)
134 return error(_("path '%s' does not have our version"), ce->name);
135 else
136 return error(_("path '%s' does not have their version"), ce->name);
137 }
138
139 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
140 {
141 unsigned seen = 0;
142 const char *name = ce->name;
143
144 while (pos < active_nr) {
145 ce = active_cache[pos];
146 if (strcmp(name, ce->name))
147 break;
148 seen |= (1 << ce_stage(ce));
149 pos++;
150 }
151 if ((stages & seen) != stages)
152 return error(_("path '%s' does not have all necessary versions"),
153 name);
154 return 0;
155 }
156
157 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
158 struct checkout *state)
159 {
160 while (pos < active_nr &&
161 !strcmp(active_cache[pos]->name, ce->name)) {
162 if (ce_stage(active_cache[pos]) == stage)
163 return checkout_entry(active_cache[pos], state, NULL);
164 pos++;
165 }
166 if (stage == 2)
167 return error(_("path '%s' does not have our version"), ce->name);
168 else
169 return error(_("path '%s' does not have their version"), ce->name);
170 }
171
172 static int checkout_merged(int pos, struct checkout *state)
173 {
174 struct cache_entry *ce = active_cache[pos];
175 const char *path = ce->name;
176 mmfile_t ancestor, ours, theirs;
177 int status;
178 unsigned char sha1[20];
179 mmbuffer_t result_buf;
180 unsigned char threeway[3][20];
181 unsigned mode = 0;
182
183 memset(threeway, 0, sizeof(threeway));
184 while (pos < active_nr) {
185 int stage;
186 stage = ce_stage(ce);
187 if (!stage || strcmp(path, ce->name))
188 break;
189 hashcpy(threeway[stage - 1], ce->sha1);
190 if (stage == 2)
191 mode = create_ce_mode(ce->ce_mode);
192 pos++;
193 ce = active_cache[pos];
194 }
195 if (is_null_sha1(threeway[1]) || is_null_sha1(threeway[2]))
196 return error(_("path '%s' does not have necessary versions"), path);
197
198 read_mmblob(&ancestor, threeway[0]);
199 read_mmblob(&ours, threeway[1]);
200 read_mmblob(&theirs, threeway[2]);
201
202 /*
203 * NEEDSWORK: re-create conflicts from merges with
204 * merge.renormalize set, too
205 */
206 status = ll_merge(&result_buf, path, &ancestor, "base",
207 &ours, "ours", &theirs, "theirs", NULL);
208 free(ancestor.ptr);
209 free(ours.ptr);
210 free(theirs.ptr);
211 if (status < 0 || !result_buf.ptr) {
212 free(result_buf.ptr);
213 return error(_("path '%s': cannot merge"), path);
214 }
215
216 /*
217 * NEEDSWORK:
218 * There is absolutely no reason to write this as a blob object
219 * and create a phony cache entry just to leak. This hack is
220 * primarily to get to the write_entry() machinery that massages
221 * the contents to work-tree format and writes out which only
222 * allows it for a cache entry. The code in write_entry() needs
223 * to be refactored to allow us to feed a <buffer, size, mode>
224 * instead of a cache entry. Such a refactoring would help
225 * merge_recursive as well (it also writes the merge result to the
226 * object database even when it may contain conflicts).
227 */
228 if (write_sha1_file(result_buf.ptr, result_buf.size,
229 blob_type, sha1))
230 die(_("Unable to add merge result for '%s'"), path);
231 ce = make_cache_entry(mode, sha1, path, 2, 0);
232 if (!ce)
233 die(_("make_cache_entry failed for path '%s'"), path);
234 status = checkout_entry(ce, state, NULL);
235 return status;
236 }
237
238 static int checkout_paths(const struct checkout_opts *opts,
239 const char *revision)
240 {
241 int pos;
242 struct checkout state;
243 static char *ps_matched;
244 unsigned char rev[20];
245 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, NULL);
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.oid.hash, 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->show_progress;
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->show_progress;
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.oid.hash :
513 EMPTY_TREE_SHA1_BIN);
514 init_tree_desc(&trees[0], tree->buffer, tree->size);
515 tree = parse_tree_indirect(new->commit->object.oid.hash);
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, 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(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 = oid_to_hex(&old->commit->object.oid);
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.oid.hash, NULL,
656 REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
657 if (!opts->quiet) {
658 if (old->path &&
659 advice_detached_head && !opts->force_detach)
660 detach_advice(new->name);
661 describe_detached_head(_("HEAD is now at"), new->commit);
662 }
663 } else if (new->path) { /* Switch branches. */
664 if (create_symref("HEAD", new->path, msg.buf) < 0)
665 die(_("unable to update HEAD"));
666 if (!opts->quiet) {
667 if (old->path && !strcmp(new->path, old->path)) {
668 if (opts->new_branch_force)
669 fprintf(stderr, _("Reset branch '%s'\n"),
670 new->name);
671 else
672 fprintf(stderr, _("Already on '%s'\n"),
673 new->name);
674 } else if (opts->new_branch) {
675 if (opts->branch_exists)
676 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
677 else
678 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
679 } else {
680 fprintf(stderr, _("Switched to branch '%s'\n"),
681 new->name);
682 }
683 }
684 if (old->path && old->name) {
685 if (!ref_exists(old->path) && reflog_exists(old->path))
686 delete_reflog(old->path);
687 }
688 }
689 remove_branch_state();
690 strbuf_release(&msg);
691 if (!opts->quiet &&
692 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
693 report_tracking(new);
694 }
695
696 static int add_pending_uninteresting_ref(const char *refname,
697 const struct object_id *oid,
698 int flags, void *cb_data)
699 {
700 add_pending_sha1(cb_data, refname, oid->hash, UNINTERESTING);
701 return 0;
702 }
703
704 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
705 {
706 strbuf_addstr(sb, " ");
707 strbuf_add_unique_abbrev(sb, commit->object.oid.hash, DEFAULT_ABBREV);
708 strbuf_addch(sb, ' ');
709 if (!parse_commit(commit))
710 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
711 strbuf_addch(sb, '\n');
712 }
713
714 #define ORPHAN_CUTOFF 4
715 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
716 {
717 struct commit *c, *last = NULL;
718 struct strbuf sb = STRBUF_INIT;
719 int lost = 0;
720 while ((c = get_revision(revs)) != NULL) {
721 if (lost < ORPHAN_CUTOFF)
722 describe_one_orphan(&sb, c);
723 last = c;
724 lost++;
725 }
726 if (ORPHAN_CUTOFF < lost) {
727 int more = lost - ORPHAN_CUTOFF;
728 if (more == 1)
729 describe_one_orphan(&sb, last);
730 else
731 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
732 }
733
734 fprintf(stderr,
735 Q_(
736 /* The singular version */
737 "Warning: you are leaving %d commit behind, "
738 "not connected to\n"
739 "any of your branches:\n\n"
740 "%s\n",
741 /* The plural version */
742 "Warning: you are leaving %d commits behind, "
743 "not connected to\n"
744 "any of your branches:\n\n"
745 "%s\n",
746 /* Give ngettext() the count */
747 lost),
748 lost,
749 sb.buf);
750 strbuf_release(&sb);
751
752 if (advice_detached_head)
753 fprintf(stderr,
754 Q_(
755 /* The singular version */
756 "If you want to keep it by creating a new branch, "
757 "this may be a good time\nto do so with:\n\n"
758 " git branch <new-branch-name> %s\n\n",
759 /* The plural version */
760 "If you want to keep them by creating a new branch, "
761 "this may be a good time\nto do so with:\n\n"
762 " git branch <new-branch-name> %s\n\n",
763 /* Give ngettext() the count */
764 lost),
765 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV));
766 }
767
768 /*
769 * We are about to leave commit that was at the tip of a detached
770 * HEAD. If it is not reachable from any ref, this is the last chance
771 * for the user to do so without resorting to reflog.
772 */
773 static void orphaned_commit_warning(struct commit *old, struct commit *new)
774 {
775 struct rev_info revs;
776 struct object *object = &old->object;
777 struct object_array refs;
778
779 init_revisions(&revs, NULL);
780 setup_revisions(0, NULL, &revs, NULL);
781
782 object->flags &= ~UNINTERESTING;
783 add_pending_object(&revs, object, oid_to_hex(&object->oid));
784
785 for_each_ref(add_pending_uninteresting_ref, &revs);
786 add_pending_sha1(&revs, "HEAD", new->object.oid.hash, UNINTERESTING);
787
788 refs = revs.pending;
789 revs.leak_pending = 1;
790
791 if (prepare_revision_walk(&revs))
792 die(_("internal error in revision walk"));
793 if (!(old->object.flags & UNINTERESTING))
794 suggest_reattach(old, &revs);
795 else
796 describe_detached_head(_("Previous HEAD position was"), old);
797
798 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
799 free(refs.objects);
800 }
801
802 static int switch_branches(const struct checkout_opts *opts,
803 struct branch_info *new)
804 {
805 int ret = 0;
806 struct branch_info old;
807 void *path_to_free;
808 unsigned char rev[20];
809 int flag, writeout_error = 0;
810 memset(&old, 0, sizeof(old));
811 old.path = path_to_free = resolve_refdup("HEAD", 0, rev, &flag);
812 old.commit = lookup_commit_reference_gently(rev, 1);
813 if (!(flag & REF_ISSYMREF))
814 old.path = NULL;
815
816 if (old.path)
817 skip_prefix(old.path, "refs/heads/", &old.name);
818
819 if (!new->name) {
820 new->name = "HEAD";
821 new->commit = old.commit;
822 if (!new->commit)
823 die(_("You are on a branch yet to be born"));
824 parse_commit_or_die(new->commit);
825 }
826
827 ret = merge_working_tree(opts, &old, new, &writeout_error);
828 if (ret) {
829 free(path_to_free);
830 return ret;
831 }
832
833 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
834 orphaned_commit_warning(old.commit, new->commit);
835
836 update_refs_for_switch(opts, &old, new);
837
838 ret = post_checkout_hook(old.commit, new->commit, 1);
839 free(path_to_free);
840 return ret || writeout_error;
841 }
842
843 static int git_checkout_config(const char *var, const char *value, void *cb)
844 {
845 if (!strcmp(var, "diff.ignoresubmodules")) {
846 struct checkout_opts *opts = cb;
847 handle_ignore_submodules_arg(&opts->diff_options, value);
848 return 0;
849 }
850
851 if (starts_with(var, "submodule."))
852 return parse_submodule_config_option(var, value);
853
854 return git_xmerge_config(var, value, NULL);
855 }
856
857 struct tracking_name_data {
858 /* const */ char *src_ref;
859 char *dst_ref;
860 unsigned char *dst_sha1;
861 int unique;
862 };
863
864 static int check_tracking_name(struct remote *remote, void *cb_data)
865 {
866 struct tracking_name_data *cb = cb_data;
867 struct refspec query;
868 memset(&query, 0, sizeof(struct refspec));
869 query.src = cb->src_ref;
870 if (remote_find_tracking(remote, &query) ||
871 get_sha1(query.dst, cb->dst_sha1)) {
872 free(query.dst);
873 return 0;
874 }
875 if (cb->dst_ref) {
876 free(query.dst);
877 cb->unique = 0;
878 return 0;
879 }
880 cb->dst_ref = query.dst;
881 return 0;
882 }
883
884 static const char *unique_tracking_name(const char *name, unsigned char *sha1)
885 {
886 struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
887 char src_ref[PATH_MAX];
888 snprintf(src_ref, PATH_MAX, "refs/heads/%s", name);
889 cb_data.src_ref = src_ref;
890 cb_data.dst_sha1 = sha1;
891 for_each_remote(check_tracking_name, &cb_data);
892 if (cb_data.unique)
893 return cb_data.dst_ref;
894 free(cb_data.dst_ref);
895 return NULL;
896 }
897
898 static int parse_branchname_arg(int argc, const char **argv,
899 int dwim_new_local_branch_ok,
900 struct branch_info *new,
901 struct checkout_opts *opts,
902 unsigned char rev[20])
903 {
904 struct tree **source_tree = &opts->source_tree;
905 const char **new_branch = &opts->new_branch;
906 int argcount = 0;
907 unsigned char branch_rev[20];
908 const char *arg;
909 int dash_dash_pos;
910 int has_dash_dash = 0;
911 int i;
912
913 /*
914 * case 1: git checkout <ref> -- [<paths>]
915 *
916 * <ref> must be a valid tree, everything after the '--' must be
917 * a path.
918 *
919 * case 2: git checkout -- [<paths>]
920 *
921 * everything after the '--' must be paths.
922 *
923 * case 3: git checkout <something> [--]
924 *
925 * (a) If <something> is a commit, that is to
926 * switch to the branch or detach HEAD at it. As a special case,
927 * if <something> is A...B (missing A or B means HEAD but you can
928 * omit at most one side), and if there is a unique merge base
929 * between A and B, A...B names that merge base.
930 *
931 * (b) If <something> is _not_ a commit, either "--" is present
932 * or <something> is not a path, no -t or -b was given, and
933 * and there is a tracking branch whose name is <something>
934 * in one and only one remote, then this is a short-hand to
935 * fork local <something> from that remote-tracking branch.
936 *
937 * (c) Otherwise, if "--" is present, treat it like case (1).
938 *
939 * (d) Otherwise :
940 * - if it's a reference, treat it like case (1)
941 * - else if it's a path, treat it like case (2)
942 * - else: fail.
943 *
944 * case 4: git checkout <something> <paths>
945 *
946 * The first argument must not be ambiguous.
947 * - If it's *only* a reference, treat it like case (1).
948 * - If it's only a path, treat it like case (2).
949 * - else: fail.
950 *
951 */
952 if (!argc)
953 return 0;
954
955 arg = argv[0];
956 dash_dash_pos = -1;
957 for (i = 0; i < argc; i++) {
958 if (!strcmp(argv[i], "--")) {
959 dash_dash_pos = i;
960 break;
961 }
962 }
963 if (dash_dash_pos == 0)
964 return 1; /* case (2) */
965 else if (dash_dash_pos == 1)
966 has_dash_dash = 1; /* case (3) or (1) */
967 else if (dash_dash_pos >= 2)
968 die(_("only one reference expected, %d given."), dash_dash_pos);
969
970 if (!strcmp(arg, "-"))
971 arg = "@{-1}";
972
973 if (get_sha1_mb(arg, rev)) {
974 /*
975 * Either case (3) or (4), with <something> not being
976 * a commit, or an attempt to use case (1) with an
977 * invalid ref.
978 *
979 * It's likely an error, but we need to find out if
980 * we should auto-create the branch, case (3).(b).
981 */
982 int recover_with_dwim = dwim_new_local_branch_ok;
983
984 if (!has_dash_dash &&
985 (check_filename(NULL, arg) || !no_wildcard(arg)))
986 recover_with_dwim = 0;
987 /*
988 * Accept "git checkout foo" and "git checkout foo --"
989 * as candidates for dwim.
990 */
991 if (!(argc == 1 && !has_dash_dash) &&
992 !(argc == 2 && has_dash_dash))
993 recover_with_dwim = 0;
994
995 if (recover_with_dwim) {
996 const char *remote = unique_tracking_name(arg, rev);
997 if (remote) {
998 *new_branch = arg;
999 arg = remote;
1000 /* DWIMmed to create local branch, case (3).(b) */
1001 } else {
1002 recover_with_dwim = 0;
1003 }
1004 }
1005
1006 if (!recover_with_dwim) {
1007 if (has_dash_dash)
1008 die(_("invalid reference: %s"), arg);
1009 return argcount;
1010 }
1011 }
1012
1013 /* we can't end up being in (2) anymore, eat the argument */
1014 argcount++;
1015 argv++;
1016 argc--;
1017
1018 new->name = arg;
1019 setup_branch_path(new);
1020
1021 if (!check_refname_format(new->path, 0) &&
1022 !read_ref(new->path, branch_rev))
1023 hashcpy(rev, branch_rev);
1024 else
1025 new->path = NULL; /* not an existing branch */
1026
1027 new->commit = lookup_commit_reference_gently(rev, 1);
1028 if (!new->commit) {
1029 /* not a commit */
1030 *source_tree = parse_tree_indirect(rev);
1031 } else {
1032 parse_commit_or_die(new->commit);
1033 *source_tree = new->commit->tree;
1034 }
1035
1036 if (!*source_tree) /* case (1): want a tree */
1037 die(_("reference is not a tree: %s"), arg);
1038 if (!has_dash_dash) {/* case (3).(d) -> (1) */
1039 /*
1040 * Do not complain the most common case
1041 * git checkout branch
1042 * even if there happen to be a file called 'branch';
1043 * it would be extremely annoying.
1044 */
1045 if (argc)
1046 verify_non_filename(NULL, arg);
1047 } else {
1048 argcount++;
1049 argv++;
1050 argc--;
1051 }
1052
1053 return argcount;
1054 }
1055
1056 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1057 {
1058 int status;
1059 struct strbuf branch_ref = STRBUF_INIT;
1060
1061 if (!opts->new_branch)
1062 die(_("You are on a branch yet to be born"));
1063 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1064 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1065 strbuf_release(&branch_ref);
1066 if (!opts->quiet)
1067 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1068 opts->new_branch);
1069 return status;
1070 }
1071
1072 static int checkout_branch(struct checkout_opts *opts,
1073 struct branch_info *new)
1074 {
1075 if (opts->pathspec.nr)
1076 die(_("paths cannot be used with switching branches"));
1077
1078 if (opts->patch_mode)
1079 die(_("'%s' cannot be used with switching branches"),
1080 "--patch");
1081
1082 if (opts->writeout_stage)
1083 die(_("'%s' cannot be used with switching branches"),
1084 "--ours/--theirs");
1085
1086 if (opts->force && opts->merge)
1087 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1088
1089 if (opts->force_detach && opts->new_branch)
1090 die(_("'%s' cannot be used with '%s'"),
1091 "--detach", "-b/-B/--orphan");
1092
1093 if (opts->new_orphan_branch) {
1094 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1095 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1096 } else if (opts->force_detach) {
1097 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1098 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1099 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1100 opts->track = git_branch_track;
1101
1102 if (new->name && !new->commit)
1103 die(_("Cannot switch branch to a non-commit '%s'"),
1104 new->name);
1105
1106 if (new->path && !opts->force_detach && !opts->new_branch &&
1107 !opts->ignore_other_worktrees) {
1108 unsigned char sha1[20];
1109 int flag;
1110 char *head_ref = resolve_refdup("HEAD", 0, sha1, &flag);
1111 if (head_ref &&
1112 (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)))
1113 die_if_checked_out(new->path, 1);
1114 free(head_ref);
1115 }
1116
1117 if (!new->commit && opts->new_branch) {
1118 unsigned char rev[20];
1119 int flag;
1120
1121 if (!read_ref_full("HEAD", 0, rev, &flag) &&
1122 (flag & REF_ISSYMREF) && is_null_sha1(rev))
1123 return switch_unborn_to_new_branch(opts);
1124 }
1125 return switch_branches(opts, new);
1126 }
1127
1128 int cmd_checkout(int argc, const char **argv, const char *prefix)
1129 {
1130 struct checkout_opts opts;
1131 struct branch_info new;
1132 char *conflict_style = NULL;
1133 int dwim_new_local_branch = 1;
1134 struct option options[] = {
1135 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1136 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1137 N_("create and checkout a new branch")),
1138 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1139 N_("create/reset and checkout a branch")),
1140 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1141 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach the HEAD at named commit")),
1142 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1143 BRANCH_TRACK_EXPLICIT),
1144 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1145 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1146 2),
1147 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1148 3),
1149 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1150 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1151 OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1152 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1153 N_("conflict style (merge or diff3)")),
1154 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1155 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1156 N_("do not limit pathspecs to sparse entries only")),
1157 OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1158 N_("second guess 'git checkout <no-such-branch>'")),
1159 OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1160 N_("do not check if another worktree is holding the given ref")),
1161 OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
1162 OPT_END(),
1163 };
1164
1165 memset(&opts, 0, sizeof(opts));
1166 memset(&new, 0, sizeof(new));
1167 opts.overwrite_ignore = 1;
1168 opts.prefix = prefix;
1169 opts.show_progress = -1;
1170
1171 gitmodules_config();
1172 git_config(git_checkout_config, &opts);
1173
1174 opts.track = BRANCH_TRACK_UNSPECIFIED;
1175
1176 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1177 PARSE_OPT_KEEP_DASHDASH);
1178
1179 if (opts.show_progress < 0) {
1180 if (opts.quiet)
1181 opts.show_progress = 0;
1182 else
1183 opts.show_progress = isatty(2);
1184 }
1185
1186 if (conflict_style) {
1187 opts.merge = 1; /* implied */
1188 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1189 }
1190
1191 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1192 die(_("-b, -B and --orphan are mutually exclusive"));
1193
1194 /*
1195 * From here on, new_branch will contain the branch to be checked out,
1196 * and new_branch_force and new_orphan_branch will tell us which one of
1197 * -b/-B/--orphan is being used.
1198 */
1199 if (opts.new_branch_force)
1200 opts.new_branch = opts.new_branch_force;
1201
1202 if (opts.new_orphan_branch)
1203 opts.new_branch = opts.new_orphan_branch;
1204
1205 /* --track without -b/-B/--orphan should DWIM */
1206 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1207 const char *argv0 = argv[0];
1208 if (!argc || !strcmp(argv0, "--"))
1209 die (_("--track needs a branch name"));
1210 skip_prefix(argv0, "refs/", &argv0);
1211 skip_prefix(argv0, "remotes/", &argv0);
1212 argv0 = strchr(argv0, '/');
1213 if (!argv0 || !argv0[1])
1214 die (_("Missing branch name; try -b"));
1215 opts.new_branch = argv0 + 1;
1216 }
1217
1218 /*
1219 * Extract branch name from command line arguments, so
1220 * all that is left is pathspecs.
1221 *
1222 * Handle
1223 *
1224 * 1) git checkout <tree> -- [<paths>]
1225 * 2) git checkout -- [<paths>]
1226 * 3) git checkout <something> [<paths>]
1227 *
1228 * including "last branch" syntax and DWIM-ery for names of
1229 * remote branches, erroring out for invalid or ambiguous cases.
1230 */
1231 if (argc) {
1232 unsigned char rev[20];
1233 int dwim_ok =
1234 !opts.patch_mode &&
1235 dwim_new_local_branch &&
1236 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1237 !opts.new_branch;
1238 int n = parse_branchname_arg(argc, argv, dwim_ok,
1239 &new, &opts, rev);
1240 argv += n;
1241 argc -= n;
1242 }
1243
1244 if (argc) {
1245 parse_pathspec(&opts.pathspec, 0,
1246 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1247 prefix, argv);
1248
1249 if (!opts.pathspec.nr)
1250 die(_("invalid path specification"));
1251
1252 /*
1253 * Try to give more helpful suggestion.
1254 * new_branch && argc > 1 will be caught later.
1255 */
1256 if (opts.new_branch && argc == 1)
1257 die(_("Cannot update paths and switch to branch '%s' at the same time.\n"
1258 "Did you intend to checkout '%s' which can not be resolved as commit?"),
1259 opts.new_branch, argv[0]);
1260
1261 if (opts.force_detach)
1262 die(_("git checkout: --detach does not take a path argument '%s'"),
1263 argv[0]);
1264
1265 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1266 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1267 "checking out of the index."));
1268 }
1269
1270 if (opts.new_branch) {
1271 struct strbuf buf = STRBUF_INIT;
1272
1273 opts.branch_exists =
1274 validate_new_branchname(opts.new_branch, &buf,
1275 !!opts.new_branch_force,
1276 !!opts.new_branch_force);
1277
1278 strbuf_release(&buf);
1279 }
1280
1281 if (opts.patch_mode || opts.pathspec.nr)
1282 return checkout_paths(&opts, new.name);
1283 else
1284 return checkout_branch(&opts, &new);
1285 }