Convert read_mmblob to take struct object_id.
[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->oid.hash, 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 !oidcmp(&ce->oid, &old->oid)) {
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 struct object_id oid;
179 mmbuffer_t result_buf;
180 struct object_id threeway[3];
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 oidcpy(&threeway[stage - 1], &ce->oid);
190 if (stage == 2)
191 mode = create_ce_mode(ce->ce_mode);
192 pos++;
193 ce = active_cache[pos];
194 }
195 if (is_null_oid(&threeway[1]) || is_null_oid(&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, oid.hash))
230 die(_("Unable to add merge result for '%s'"), path);
231 ce = make_cache_entry(mode, oid.hash, 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 struct object_id rev;
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(_("index file corrupt"));
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.hash, NULL);
378 head = lookup_commit_reference_gently(rev.hash, 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(_("index file corrupt"));
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 ret = merge_trees(&o, new->commit->tree, work,
571 old->commit->tree, &result);
572 if (ret < 0)
573 exit(128);
574 ret = reset_tree(new->commit->tree, opts, 0,
575 writeout_error);
576 strbuf_release(&o.obuf);
577 if (ret)
578 return ret;
579 }
580 }
581
582 if (!active_cache_tree)
583 active_cache_tree = cache_tree();
584
585 if (!cache_tree_fully_valid(active_cache_tree))
586 cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
587
588 if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
589 die(_("unable to write new index file"));
590
591 if (!opts->force && !opts->quiet)
592 show_local_changes(&new->commit->object, &opts->diff_options);
593
594 return 0;
595 }
596
597 static void report_tracking(struct branch_info *new)
598 {
599 struct strbuf sb = STRBUF_INIT;
600 struct branch *branch = branch_get(new->name);
601
602 if (!format_tracking_info(branch, &sb))
603 return;
604 fputs(sb.buf, stdout);
605 strbuf_release(&sb);
606 }
607
608 static void update_refs_for_switch(const struct checkout_opts *opts,
609 struct branch_info *old,
610 struct branch_info *new)
611 {
612 struct strbuf msg = STRBUF_INIT;
613 const char *old_desc, *reflog_msg;
614 if (opts->new_branch) {
615 if (opts->new_orphan_branch) {
616 if (opts->new_branch_log && !log_all_ref_updates) {
617 int ret;
618 char *refname;
619 struct strbuf err = STRBUF_INIT;
620
621 refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
622 ret = safe_create_reflog(refname, 1, &err);
623 free(refname);
624 if (ret) {
625 fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
626 opts->new_orphan_branch, err.buf);
627 strbuf_release(&err);
628 return;
629 }
630 strbuf_release(&err);
631 }
632 }
633 else
634 create_branch(old->name, opts->new_branch, new->name,
635 opts->new_branch_force ? 1 : 0,
636 opts->new_branch_log,
637 opts->new_branch_force ? 1 : 0,
638 opts->quiet,
639 opts->track);
640 new->name = opts->new_branch;
641 setup_branch_path(new);
642 }
643
644 old_desc = old->name;
645 if (!old_desc && old->commit)
646 old_desc = oid_to_hex(&old->commit->object.oid);
647
648 reflog_msg = getenv("GIT_REFLOG_ACTION");
649 if (!reflog_msg)
650 strbuf_addf(&msg, "checkout: moving from %s to %s",
651 old_desc ? old_desc : "(invalid)", new->name);
652 else
653 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
654
655 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
656 /* Nothing to do. */
657 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
658 update_ref(msg.buf, "HEAD", new->commit->object.oid.hash, NULL,
659 REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
660 if (!opts->quiet) {
661 if (old->path &&
662 advice_detached_head && !opts->force_detach)
663 detach_advice(new->name);
664 describe_detached_head(_("HEAD is now at"), new->commit);
665 }
666 } else if (new->path) { /* Switch branches. */
667 if (create_symref("HEAD", new->path, msg.buf) < 0)
668 die(_("unable to update HEAD"));
669 if (!opts->quiet) {
670 if (old->path && !strcmp(new->path, old->path)) {
671 if (opts->new_branch_force)
672 fprintf(stderr, _("Reset branch '%s'\n"),
673 new->name);
674 else
675 fprintf(stderr, _("Already on '%s'\n"),
676 new->name);
677 } else if (opts->new_branch) {
678 if (opts->branch_exists)
679 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
680 else
681 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
682 } else {
683 fprintf(stderr, _("Switched to branch '%s'\n"),
684 new->name);
685 }
686 }
687 if (old->path && old->name) {
688 if (!ref_exists(old->path) && reflog_exists(old->path))
689 delete_reflog(old->path);
690 }
691 }
692 remove_branch_state();
693 strbuf_release(&msg);
694 if (!opts->quiet &&
695 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
696 report_tracking(new);
697 }
698
699 static int add_pending_uninteresting_ref(const char *refname,
700 const struct object_id *oid,
701 int flags, void *cb_data)
702 {
703 add_pending_sha1(cb_data, refname, oid->hash, UNINTERESTING);
704 return 0;
705 }
706
707 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
708 {
709 strbuf_addstr(sb, " ");
710 strbuf_add_unique_abbrev(sb, commit->object.oid.hash, DEFAULT_ABBREV);
711 strbuf_addch(sb, ' ');
712 if (!parse_commit(commit))
713 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
714 strbuf_addch(sb, '\n');
715 }
716
717 #define ORPHAN_CUTOFF 4
718 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
719 {
720 struct commit *c, *last = NULL;
721 struct strbuf sb = STRBUF_INIT;
722 int lost = 0;
723 while ((c = get_revision(revs)) != NULL) {
724 if (lost < ORPHAN_CUTOFF)
725 describe_one_orphan(&sb, c);
726 last = c;
727 lost++;
728 }
729 if (ORPHAN_CUTOFF < lost) {
730 int more = lost - ORPHAN_CUTOFF;
731 if (more == 1)
732 describe_one_orphan(&sb, last);
733 else
734 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
735 }
736
737 fprintf(stderr,
738 Q_(
739 /* The singular version */
740 "Warning: you are leaving %d commit behind, "
741 "not connected to\n"
742 "any of your branches:\n\n"
743 "%s\n",
744 /* The plural version */
745 "Warning: you are leaving %d commits behind, "
746 "not connected to\n"
747 "any of your branches:\n\n"
748 "%s\n",
749 /* Give ngettext() the count */
750 lost),
751 lost,
752 sb.buf);
753 strbuf_release(&sb);
754
755 if (advice_detached_head)
756 fprintf(stderr,
757 Q_(
758 /* The singular version */
759 "If you want to keep it by creating a new branch, "
760 "this may be a good time\nto do so with:\n\n"
761 " git branch <new-branch-name> %s\n\n",
762 /* The plural version */
763 "If you want to keep them by creating a new branch, "
764 "this may be a good time\nto do so with:\n\n"
765 " git branch <new-branch-name> %s\n\n",
766 /* Give ngettext() the count */
767 lost),
768 find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV));
769 }
770
771 /*
772 * We are about to leave commit that was at the tip of a detached
773 * HEAD. If it is not reachable from any ref, this is the last chance
774 * for the user to do so without resorting to reflog.
775 */
776 static void orphaned_commit_warning(struct commit *old, struct commit *new)
777 {
778 struct rev_info revs;
779 struct object *object = &old->object;
780 struct object_array refs;
781
782 init_revisions(&revs, NULL);
783 setup_revisions(0, NULL, &revs, NULL);
784
785 object->flags &= ~UNINTERESTING;
786 add_pending_object(&revs, object, oid_to_hex(&object->oid));
787
788 for_each_ref(add_pending_uninteresting_ref, &revs);
789 add_pending_sha1(&revs, "HEAD", new->object.oid.hash, UNINTERESTING);
790
791 refs = revs.pending;
792 revs.leak_pending = 1;
793
794 if (prepare_revision_walk(&revs))
795 die(_("internal error in revision walk"));
796 if (!(old->object.flags & UNINTERESTING))
797 suggest_reattach(old, &revs);
798 else
799 describe_detached_head(_("Previous HEAD position was"), old);
800
801 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
802 free(refs.objects);
803 }
804
805 static int switch_branches(const struct checkout_opts *opts,
806 struct branch_info *new)
807 {
808 int ret = 0;
809 struct branch_info old;
810 void *path_to_free;
811 struct object_id rev;
812 int flag, writeout_error = 0;
813 memset(&old, 0, sizeof(old));
814 old.path = path_to_free = resolve_refdup("HEAD", 0, rev.hash, &flag);
815 old.commit = lookup_commit_reference_gently(rev.hash, 1);
816 if (!(flag & REF_ISSYMREF))
817 old.path = NULL;
818
819 if (old.path)
820 skip_prefix(old.path, "refs/heads/", &old.name);
821
822 if (!new->name) {
823 new->name = "HEAD";
824 new->commit = old.commit;
825 if (!new->commit)
826 die(_("You are on a branch yet to be born"));
827 parse_commit_or_die(new->commit);
828 }
829
830 ret = merge_working_tree(opts, &old, new, &writeout_error);
831 if (ret) {
832 free(path_to_free);
833 return ret;
834 }
835
836 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
837 orphaned_commit_warning(old.commit, new->commit);
838
839 update_refs_for_switch(opts, &old, new);
840
841 ret = post_checkout_hook(old.commit, new->commit, 1);
842 free(path_to_free);
843 return ret || writeout_error;
844 }
845
846 static int git_checkout_config(const char *var, const char *value, void *cb)
847 {
848 if (!strcmp(var, "diff.ignoresubmodules")) {
849 struct checkout_opts *opts = cb;
850 handle_ignore_submodules_arg(&opts->diff_options, value);
851 return 0;
852 }
853
854 if (starts_with(var, "submodule."))
855 return parse_submodule_config_option(var, value);
856
857 return git_xmerge_config(var, value, NULL);
858 }
859
860 struct tracking_name_data {
861 /* const */ char *src_ref;
862 char *dst_ref;
863 struct object_id *dst_oid;
864 int unique;
865 };
866
867 static int check_tracking_name(struct remote *remote, void *cb_data)
868 {
869 struct tracking_name_data *cb = cb_data;
870 struct refspec query;
871 memset(&query, 0, sizeof(struct refspec));
872 query.src = cb->src_ref;
873 if (remote_find_tracking(remote, &query) ||
874 get_oid(query.dst, cb->dst_oid)) {
875 free(query.dst);
876 return 0;
877 }
878 if (cb->dst_ref) {
879 free(query.dst);
880 cb->unique = 0;
881 return 0;
882 }
883 cb->dst_ref = query.dst;
884 return 0;
885 }
886
887 static const char *unique_tracking_name(const char *name, struct object_id *oid)
888 {
889 struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
890 char src_ref[PATH_MAX];
891 snprintf(src_ref, PATH_MAX, "refs/heads/%s", name);
892 cb_data.src_ref = src_ref;
893 cb_data.dst_oid = oid;
894 for_each_remote(check_tracking_name, &cb_data);
895 if (cb_data.unique)
896 return cb_data.dst_ref;
897 free(cb_data.dst_ref);
898 return NULL;
899 }
900
901 static int parse_branchname_arg(int argc, const char **argv,
902 int dwim_new_local_branch_ok,
903 struct branch_info *new,
904 struct checkout_opts *opts,
905 struct object_id *rev)
906 {
907 struct tree **source_tree = &opts->source_tree;
908 const char **new_branch = &opts->new_branch;
909 int argcount = 0;
910 struct object_id branch_rev;
911 const char *arg;
912 int dash_dash_pos;
913 int has_dash_dash = 0;
914 int i;
915
916 /*
917 * case 1: git checkout <ref> -- [<paths>]
918 *
919 * <ref> must be a valid tree, everything after the '--' must be
920 * a path.
921 *
922 * case 2: git checkout -- [<paths>]
923 *
924 * everything after the '--' must be paths.
925 *
926 * case 3: git checkout <something> [--]
927 *
928 * (a) If <something> is a commit, that is to
929 * switch to the branch or detach HEAD at it. As a special case,
930 * if <something> is A...B (missing A or B means HEAD but you can
931 * omit at most one side), and if there is a unique merge base
932 * between A and B, A...B names that merge base.
933 *
934 * (b) If <something> is _not_ a commit, either "--" is present
935 * or <something> is not a path, no -t or -b was given, and
936 * and there is a tracking branch whose name is <something>
937 * in one and only one remote, then this is a short-hand to
938 * fork local <something> from that remote-tracking branch.
939 *
940 * (c) Otherwise, if "--" is present, treat it like case (1).
941 *
942 * (d) Otherwise :
943 * - if it's a reference, treat it like case (1)
944 * - else if it's a path, treat it like case (2)
945 * - else: fail.
946 *
947 * case 4: git checkout <something> <paths>
948 *
949 * The first argument must not be ambiguous.
950 * - If it's *only* a reference, treat it like case (1).
951 * - If it's only a path, treat it like case (2).
952 * - else: fail.
953 *
954 */
955 if (!argc)
956 return 0;
957
958 arg = argv[0];
959 dash_dash_pos = -1;
960 for (i = 0; i < argc; i++) {
961 if (!strcmp(argv[i], "--")) {
962 dash_dash_pos = i;
963 break;
964 }
965 }
966 if (dash_dash_pos == 0)
967 return 1; /* case (2) */
968 else if (dash_dash_pos == 1)
969 has_dash_dash = 1; /* case (3) or (1) */
970 else if (dash_dash_pos >= 2)
971 die(_("only one reference expected, %d given."), dash_dash_pos);
972
973 if (!strcmp(arg, "-"))
974 arg = "@{-1}";
975
976 if (get_sha1_mb(arg, rev->hash)) {
977 /*
978 * Either case (3) or (4), with <something> not being
979 * a commit, or an attempt to use case (1) with an
980 * invalid ref.
981 *
982 * It's likely an error, but we need to find out if
983 * we should auto-create the branch, case (3).(b).
984 */
985 int recover_with_dwim = dwim_new_local_branch_ok;
986
987 if (!has_dash_dash &&
988 (check_filename(NULL, arg) || !no_wildcard(arg)))
989 recover_with_dwim = 0;
990 /*
991 * Accept "git checkout foo" and "git checkout foo --"
992 * as candidates for dwim.
993 */
994 if (!(argc == 1 && !has_dash_dash) &&
995 !(argc == 2 && has_dash_dash))
996 recover_with_dwim = 0;
997
998 if (recover_with_dwim) {
999 const char *remote = unique_tracking_name(arg, rev);
1000 if (remote) {
1001 *new_branch = arg;
1002 arg = remote;
1003 /* DWIMmed to create local branch, case (3).(b) */
1004 } else {
1005 recover_with_dwim = 0;
1006 }
1007 }
1008
1009 if (!recover_with_dwim) {
1010 if (has_dash_dash)
1011 die(_("invalid reference: %s"), arg);
1012 return argcount;
1013 }
1014 }
1015
1016 /* we can't end up being in (2) anymore, eat the argument */
1017 argcount++;
1018 argv++;
1019 argc--;
1020
1021 new->name = arg;
1022 setup_branch_path(new);
1023
1024 if (!check_refname_format(new->path, 0) &&
1025 !read_ref(new->path, branch_rev.hash))
1026 oidcpy(rev, &branch_rev);
1027 else
1028 new->path = NULL; /* not an existing branch */
1029
1030 new->commit = lookup_commit_reference_gently(rev->hash, 1);
1031 if (!new->commit) {
1032 /* not a commit */
1033 *source_tree = parse_tree_indirect(rev->hash);
1034 } else {
1035 parse_commit_or_die(new->commit);
1036 *source_tree = new->commit->tree;
1037 }
1038
1039 if (!*source_tree) /* case (1): want a tree */
1040 die(_("reference is not a tree: %s"), arg);
1041 if (!has_dash_dash) {/* case (3).(d) -> (1) */
1042 /*
1043 * Do not complain the most common case
1044 * git checkout branch
1045 * even if there happen to be a file called 'branch';
1046 * it would be extremely annoying.
1047 */
1048 if (argc)
1049 verify_non_filename(NULL, arg);
1050 } else {
1051 argcount++;
1052 argv++;
1053 argc--;
1054 }
1055
1056 return argcount;
1057 }
1058
1059 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1060 {
1061 int status;
1062 struct strbuf branch_ref = STRBUF_INIT;
1063
1064 if (!opts->new_branch)
1065 die(_("You are on a branch yet to be born"));
1066 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1067 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1068 strbuf_release(&branch_ref);
1069 if (!opts->quiet)
1070 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1071 opts->new_branch);
1072 return status;
1073 }
1074
1075 static int checkout_branch(struct checkout_opts *opts,
1076 struct branch_info *new)
1077 {
1078 if (opts->pathspec.nr)
1079 die(_("paths cannot be used with switching branches"));
1080
1081 if (opts->patch_mode)
1082 die(_("'%s' cannot be used with switching branches"),
1083 "--patch");
1084
1085 if (opts->writeout_stage)
1086 die(_("'%s' cannot be used with switching branches"),
1087 "--ours/--theirs");
1088
1089 if (opts->force && opts->merge)
1090 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1091
1092 if (opts->force_detach && opts->new_branch)
1093 die(_("'%s' cannot be used with '%s'"),
1094 "--detach", "-b/-B/--orphan");
1095
1096 if (opts->new_orphan_branch) {
1097 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1098 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1099 } else if (opts->force_detach) {
1100 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1101 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1102 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1103 opts->track = git_branch_track;
1104
1105 if (new->name && !new->commit)
1106 die(_("Cannot switch branch to a non-commit '%s'"),
1107 new->name);
1108
1109 if (new->path && !opts->force_detach && !opts->new_branch &&
1110 !opts->ignore_other_worktrees) {
1111 struct object_id oid;
1112 int flag;
1113 char *head_ref = resolve_refdup("HEAD", 0, oid.hash, &flag);
1114 if (head_ref &&
1115 (!(flag & REF_ISSYMREF) || strcmp(head_ref, new->path)))
1116 die_if_checked_out(new->path, 1);
1117 free(head_ref);
1118 }
1119
1120 if (!new->commit && opts->new_branch) {
1121 struct object_id rev;
1122 int flag;
1123
1124 if (!read_ref_full("HEAD", 0, rev.hash, &flag) &&
1125 (flag & REF_ISSYMREF) && is_null_oid(&rev))
1126 return switch_unborn_to_new_branch(opts);
1127 }
1128 return switch_branches(opts, new);
1129 }
1130
1131 int cmd_checkout(int argc, const char **argv, const char *prefix)
1132 {
1133 struct checkout_opts opts;
1134 struct branch_info new;
1135 char *conflict_style = NULL;
1136 int dwim_new_local_branch = 1;
1137 struct option options[] = {
1138 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1139 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1140 N_("create and checkout a new branch")),
1141 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1142 N_("create/reset and checkout a branch")),
1143 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1144 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach HEAD at named commit")),
1145 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1146 BRANCH_TRACK_EXPLICIT),
1147 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
1148 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1149 2),
1150 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1151 3),
1152 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1153 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1154 OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1155 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1156 N_("conflict style (merge or diff3)")),
1157 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1158 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1159 N_("do not limit pathspecs to sparse entries only")),
1160 OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1161 N_("second guess 'git checkout <no-such-branch>'")),
1162 OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1163 N_("do not check if another worktree is holding the given ref")),
1164 OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
1165 OPT_END(),
1166 };
1167
1168 memset(&opts, 0, sizeof(opts));
1169 memset(&new, 0, sizeof(new));
1170 opts.overwrite_ignore = 1;
1171 opts.prefix = prefix;
1172 opts.show_progress = -1;
1173
1174 gitmodules_config();
1175 git_config(git_checkout_config, &opts);
1176
1177 opts.track = BRANCH_TRACK_UNSPECIFIED;
1178
1179 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1180 PARSE_OPT_KEEP_DASHDASH);
1181
1182 if (opts.show_progress < 0) {
1183 if (opts.quiet)
1184 opts.show_progress = 0;
1185 else
1186 opts.show_progress = isatty(2);
1187 }
1188
1189 if (conflict_style) {
1190 opts.merge = 1; /* implied */
1191 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1192 }
1193
1194 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1195 die(_("-b, -B and --orphan are mutually exclusive"));
1196
1197 /*
1198 * From here on, new_branch will contain the branch to be checked out,
1199 * and new_branch_force and new_orphan_branch will tell us which one of
1200 * -b/-B/--orphan is being used.
1201 */
1202 if (opts.new_branch_force)
1203 opts.new_branch = opts.new_branch_force;
1204
1205 if (opts.new_orphan_branch)
1206 opts.new_branch = opts.new_orphan_branch;
1207
1208 /* --track without -b/-B/--orphan should DWIM */
1209 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1210 const char *argv0 = argv[0];
1211 if (!argc || !strcmp(argv0, "--"))
1212 die (_("--track needs a branch name"));
1213 skip_prefix(argv0, "refs/", &argv0);
1214 skip_prefix(argv0, "remotes/", &argv0);
1215 argv0 = strchr(argv0, '/');
1216 if (!argv0 || !argv0[1])
1217 die (_("Missing branch name; try -b"));
1218 opts.new_branch = argv0 + 1;
1219 }
1220
1221 /*
1222 * Extract branch name from command line arguments, so
1223 * all that is left is pathspecs.
1224 *
1225 * Handle
1226 *
1227 * 1) git checkout <tree> -- [<paths>]
1228 * 2) git checkout -- [<paths>]
1229 * 3) git checkout <something> [<paths>]
1230 *
1231 * including "last branch" syntax and DWIM-ery for names of
1232 * remote branches, erroring out for invalid or ambiguous cases.
1233 */
1234 if (argc) {
1235 struct object_id rev;
1236 int dwim_ok =
1237 !opts.patch_mode &&
1238 dwim_new_local_branch &&
1239 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1240 !opts.new_branch;
1241 int n = parse_branchname_arg(argc, argv, dwim_ok,
1242 &new, &opts, &rev);
1243 argv += n;
1244 argc -= n;
1245 }
1246
1247 if (argc) {
1248 parse_pathspec(&opts.pathspec, 0,
1249 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1250 prefix, argv);
1251
1252 if (!opts.pathspec.nr)
1253 die(_("invalid path specification"));
1254
1255 /*
1256 * Try to give more helpful suggestion.
1257 * new_branch && argc > 1 will be caught later.
1258 */
1259 if (opts.new_branch && argc == 1)
1260 die(_("Cannot update paths and switch to branch '%s' at the same time.\n"
1261 "Did you intend to checkout '%s' which can not be resolved as commit?"),
1262 opts.new_branch, argv[0]);
1263
1264 if (opts.force_detach)
1265 die(_("git checkout: --detach does not take a path argument '%s'"),
1266 argv[0]);
1267
1268 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1269 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1270 "checking out of the index."));
1271 }
1272
1273 if (opts.new_branch) {
1274 struct strbuf buf = STRBUF_INIT;
1275
1276 opts.branch_exists =
1277 validate_new_branchname(opts.new_branch, &buf,
1278 !!opts.new_branch_force,
1279 !!opts.new_branch_force);
1280
1281 strbuf_release(&buf);
1282 }
1283
1284 if (opts.patch_mode || opts.pathspec.nr)
1285 return checkout_paths(&opts, new.name);
1286 else
1287 return checkout_branch(&opts, &new);
1288 }