convert read_cache_preload() to take struct pathspec
[git/git.git] / builtin / checkout.c
1 #include "cache.h"
2 #include "builtin.h"
3 #include "parse-options.h"
4 #include "refs.h"
5 #include "commit.h"
6 #include "tree.h"
7 #include "tree-walk.h"
8 #include "cache-tree.h"
9 #include "unpack-trees.h"
10 #include "dir.h"
11 #include "run-command.h"
12 #include "merge-recursive.h"
13 #include "branch.h"
14 #include "diff.h"
15 #include "revision.h"
16 #include "remote.h"
17 #include "blob.h"
18 #include "xdiff-interface.h"
19 #include "ll-merge.h"
20 #include "resolve-undo.h"
21 #include "submodule.h"
22 #include "argv-array.h"
23
24 static const char * const checkout_usage[] = {
25 N_("git checkout [options] <branch>"),
26 N_("git checkout [options] [<branch>] -- <file>..."),
27 NULL,
28 };
29
30 struct checkout_opts {
31 int patch_mode;
32 int quiet;
33 int merge;
34 int force;
35 int force_detach;
36 int writeout_stage;
37 int overwrite_ignore;
38 int ignore_skipworktree;
39
40 const char *new_branch;
41 const char *new_branch_force;
42 const char *new_orphan_branch;
43 int new_branch_log;
44 enum branch_track track;
45 struct diff_options diff_options;
46
47 int branch_exists;
48 const char *prefix;
49 struct pathspec pathspec;
50 struct tree *source_tree;
51 };
52
53 static int post_checkout_hook(struct commit *old, struct commit *new,
54 int changed)
55 {
56 return run_hook(NULL, "post-checkout",
57 sha1_to_hex(old ? old->object.sha1 : null_sha1),
58 sha1_to_hex(new ? new->object.sha1 : null_sha1),
59 changed ? "1" : "0", NULL);
60 /* "new" can be NULL when checking out from the index before
61 a commit exists. */
62
63 }
64
65 static int update_some(const unsigned char *sha1, const char *base, int baselen,
66 const char *pathname, unsigned mode, int stage, void *context)
67 {
68 int len;
69 struct cache_entry *ce;
70
71 if (S_ISDIR(mode))
72 return READ_TREE_RECURSIVE;
73
74 len = baselen + strlen(pathname);
75 ce = xcalloc(1, cache_entry_size(len));
76 hashcpy(ce->sha1, sha1);
77 memcpy(ce->name, base, baselen);
78 memcpy(ce->name + baselen, pathname, len - baselen);
79 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
80 ce->ce_namelen = len;
81 ce->ce_mode = create_ce_mode(mode);
82 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
83 return 0;
84 }
85
86 static int read_tree_some(struct tree *tree, const char **pathspec)
87 {
88 struct pathspec ps;
89 init_pathspec(&ps, pathspec);
90 read_tree_recursive(tree, "", 0, 0, &ps, update_some, NULL);
91 free_pathspec(&ps);
92
93 /* update the index with the given tree's info
94 * for all args, expanding wildcards, and exit
95 * with any non-zero return code.
96 */
97 return 0;
98 }
99
100 static int skip_same_name(struct cache_entry *ce, int pos)
101 {
102 while (++pos < active_nr &&
103 !strcmp(active_cache[pos]->name, ce->name))
104 ; /* skip */
105 return pos;
106 }
107
108 static int check_stage(int stage, struct cache_entry *ce, int pos)
109 {
110 while (pos < active_nr &&
111 !strcmp(active_cache[pos]->name, ce->name)) {
112 if (ce_stage(active_cache[pos]) == stage)
113 return 0;
114 pos++;
115 }
116 if (stage == 2)
117 return error(_("path '%s' does not have our version"), ce->name);
118 else
119 return error(_("path '%s' does not have their version"), ce->name);
120 }
121
122 static int check_stages(unsigned stages, struct cache_entry *ce, int pos)
123 {
124 unsigned seen = 0;
125 const char *name = ce->name;
126
127 while (pos < active_nr) {
128 ce = active_cache[pos];
129 if (strcmp(name, ce->name))
130 break;
131 seen |= (1 << ce_stage(ce));
132 pos++;
133 }
134 if ((stages & seen) != stages)
135 return error(_("path '%s' does not have all necessary versions"),
136 name);
137 return 0;
138 }
139
140 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
141 struct checkout *state)
142 {
143 while (pos < active_nr &&
144 !strcmp(active_cache[pos]->name, ce->name)) {
145 if (ce_stage(active_cache[pos]) == stage)
146 return checkout_entry(active_cache[pos], state, NULL);
147 pos++;
148 }
149 if (stage == 2)
150 return error(_("path '%s' does not have our version"), ce->name);
151 else
152 return error(_("path '%s' does not have their version"), ce->name);
153 }
154
155 static int checkout_merged(int pos, struct checkout *state)
156 {
157 struct cache_entry *ce = active_cache[pos];
158 const char *path = ce->name;
159 mmfile_t ancestor, ours, theirs;
160 int status;
161 unsigned char sha1[20];
162 mmbuffer_t result_buf;
163 unsigned char threeway[3][20];
164 unsigned mode = 0;
165
166 memset(threeway, 0, sizeof(threeway));
167 while (pos < active_nr) {
168 int stage;
169 stage = ce_stage(ce);
170 if (!stage || strcmp(path, ce->name))
171 break;
172 hashcpy(threeway[stage - 1], ce->sha1);
173 if (stage == 2)
174 mode = create_ce_mode(ce->ce_mode);
175 pos++;
176 ce = active_cache[pos];
177 }
178 if (is_null_sha1(threeway[1]) || is_null_sha1(threeway[2]))
179 return error(_("path '%s' does not have necessary versions"), path);
180
181 read_mmblob(&ancestor, threeway[0]);
182 read_mmblob(&ours, threeway[1]);
183 read_mmblob(&theirs, threeway[2]);
184
185 /*
186 * NEEDSWORK: re-create conflicts from merges with
187 * merge.renormalize set, too
188 */
189 status = ll_merge(&result_buf, path, &ancestor, "base",
190 &ours, "ours", &theirs, "theirs", NULL);
191 free(ancestor.ptr);
192 free(ours.ptr);
193 free(theirs.ptr);
194 if (status < 0 || !result_buf.ptr) {
195 free(result_buf.ptr);
196 return error(_("path '%s': cannot merge"), path);
197 }
198
199 /*
200 * NEEDSWORK:
201 * There is absolutely no reason to write this as a blob object
202 * and create a phony cache entry just to leak. This hack is
203 * primarily to get to the write_entry() machinery that massages
204 * the contents to work-tree format and writes out which only
205 * allows it for a cache entry. The code in write_entry() needs
206 * to be refactored to allow us to feed a <buffer, size, mode>
207 * instead of a cache entry. Such a refactoring would help
208 * merge_recursive as well (it also writes the merge result to the
209 * object database even when it may contain conflicts).
210 */
211 if (write_sha1_file(result_buf.ptr, result_buf.size,
212 blob_type, sha1))
213 die(_("Unable to add merge result for '%s'"), path);
214 ce = make_cache_entry(mode, sha1, path, 2, 0);
215 if (!ce)
216 die(_("make_cache_entry failed for path '%s'"), path);
217 status = checkout_entry(ce, state, NULL);
218 return status;
219 }
220
221 static int checkout_paths(const struct checkout_opts *opts,
222 const char *revision)
223 {
224 int pos;
225 struct checkout state;
226 static char *ps_matched;
227 unsigned char rev[20];
228 int flag;
229 struct commit *head;
230 int errs = 0;
231 int stage = opts->writeout_stage;
232 int merge = opts->merge;
233 int newfd;
234 struct lock_file *lock_file;
235
236 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
237 die(_("'%s' cannot be used with updating paths"), "--track");
238
239 if (opts->new_branch_log)
240 die(_("'%s' cannot be used with updating paths"), "-l");
241
242 if (opts->force && opts->patch_mode)
243 die(_("'%s' cannot be used with updating paths"), "-f");
244
245 if (opts->force_detach)
246 die(_("'%s' cannot be used with updating paths"), "--detach");
247
248 if (opts->merge && opts->patch_mode)
249 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
250
251 if (opts->force && opts->merge)
252 die(_("'%s' cannot be used with %s"), "-f", "-m");
253
254 if (opts->new_branch)
255 die(_("Cannot update paths and switch to branch '%s' at the same time."),
256 opts->new_branch);
257
258 if (opts->patch_mode)
259 return run_add_interactive(revision, "--patch=checkout",
260 opts->pathspec.raw);
261
262 lock_file = xcalloc(1, sizeof(struct lock_file));
263
264 newfd = hold_locked_index(lock_file, 1);
265 if (read_cache_preload(&opts->pathspec) < 0)
266 return error(_("corrupt index file"));
267
268 if (opts->source_tree)
269 read_tree_some(opts->source_tree, opts->pathspec.raw);
270
271 ps_matched = xcalloc(1, opts->pathspec.nr);
272
273 /*
274 * Make sure all pathspecs participated in locating the paths
275 * to be checked out.
276 */
277 for (pos = 0; pos < active_nr; pos++) {
278 struct cache_entry *ce = active_cache[pos];
279 ce->ce_flags &= ~CE_MATCHED;
280 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
281 continue;
282 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
283 /*
284 * "git checkout tree-ish -- path", but this entry
285 * is in the original index; it will not be checked
286 * out to the working tree and it does not matter
287 * if pathspec matched this entry. We will not do
288 * anything to this entry at all.
289 */
290 continue;
291 /*
292 * Either this entry came from the tree-ish we are
293 * checking the paths out of, or we are checking out
294 * of the index.
295 *
296 * If it comes from the tree-ish, we already know it
297 * matches the pathspec and could just stamp
298 * CE_MATCHED to it from update_some(). But we still
299 * need ps_matched and read_tree_recursive (and
300 * eventually tree_entry_interesting) cannot fill
301 * ps_matched yet. Once it can, we can avoid calling
302 * match_pathspec() for _all_ entries when
303 * opts->source_tree != NULL.
304 */
305 if (match_pathspec_depth(&opts->pathspec, ce->name, ce_namelen(ce),
306 0, ps_matched))
307 ce->ce_flags |= CE_MATCHED;
308 }
309
310 if (report_path_error(ps_matched, opts->pathspec.raw, opts->prefix)) {
311 free(ps_matched);
312 return 1;
313 }
314 free(ps_matched);
315
316 /* "checkout -m path" to recreate conflicted state */
317 if (opts->merge)
318 unmerge_marked_index(&the_index);
319
320 /* Any unmerged paths? */
321 for (pos = 0; pos < active_nr; pos++) {
322 struct cache_entry *ce = active_cache[pos];
323 if (ce->ce_flags & CE_MATCHED) {
324 if (!ce_stage(ce))
325 continue;
326 if (opts->force) {
327 warning(_("path '%s' is unmerged"), ce->name);
328 } else if (stage) {
329 errs |= check_stage(stage, ce, pos);
330 } else if (opts->merge) {
331 errs |= check_stages((1<<2) | (1<<3), ce, pos);
332 } else {
333 errs = 1;
334 error(_("path '%s' is unmerged"), ce->name);
335 }
336 pos = skip_same_name(ce, pos) - 1;
337 }
338 }
339 if (errs)
340 return 1;
341
342 /* Now we are committed to check them out */
343 memset(&state, 0, sizeof(state));
344 state.force = 1;
345 state.refresh_cache = 1;
346 for (pos = 0; pos < active_nr; pos++) {
347 struct cache_entry *ce = active_cache[pos];
348 if (ce->ce_flags & CE_MATCHED) {
349 if (!ce_stage(ce)) {
350 errs |= checkout_entry(ce, &state, NULL);
351 continue;
352 }
353 if (stage)
354 errs |= checkout_stage(stage, ce, pos, &state);
355 else if (merge)
356 errs |= checkout_merged(pos, &state);
357 pos = skip_same_name(ce, pos) - 1;
358 }
359 }
360
361 if (write_cache(newfd, active_cache, active_nr) ||
362 commit_locked_index(lock_file))
363 die(_("unable to write new index file"));
364
365 read_ref_full("HEAD", rev, 0, &flag);
366 head = lookup_commit_reference_gently(rev, 1);
367
368 errs |= post_checkout_hook(head, head, 0);
369 return errs;
370 }
371
372 static void show_local_changes(struct object *head,
373 const struct diff_options *opts)
374 {
375 struct rev_info rev;
376 /* I think we want full paths, even if we're in a subdirectory. */
377 init_revisions(&rev, NULL);
378 rev.diffopt.flags = opts->flags;
379 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
380 diff_setup_done(&rev.diffopt);
381 add_pending_object(&rev, head, NULL);
382 run_diff_index(&rev, 0);
383 }
384
385 static void describe_detached_head(const char *msg, struct commit *commit)
386 {
387 struct strbuf sb = STRBUF_INIT;
388 parse_commit(commit);
389 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
390 fprintf(stderr, "%s %s... %s\n", msg,
391 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
392 strbuf_release(&sb);
393 }
394
395 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
396 int worktree, int *writeout_error)
397 {
398 struct unpack_trees_options opts;
399 struct tree_desc tree_desc;
400
401 memset(&opts, 0, sizeof(opts));
402 opts.head_idx = -1;
403 opts.update = worktree;
404 opts.skip_unmerged = !worktree;
405 opts.reset = 1;
406 opts.merge = 1;
407 opts.fn = oneway_merge;
408 opts.verbose_update = !o->quiet && isatty(2);
409 opts.src_index = &the_index;
410 opts.dst_index = &the_index;
411 parse_tree(tree);
412 init_tree_desc(&tree_desc, tree->buffer, tree->size);
413 switch (unpack_trees(1, &tree_desc, &opts)) {
414 case -2:
415 *writeout_error = 1;
416 /*
417 * We return 0 nevertheless, as the index is all right
418 * and more importantly we have made best efforts to
419 * update paths in the work tree, and we cannot revert
420 * them.
421 */
422 case 0:
423 return 0;
424 default:
425 return 128;
426 }
427 }
428
429 struct branch_info {
430 const char *name; /* The short name used */
431 const char *path; /* The full name of a real branch */
432 struct commit *commit; /* The named commit */
433 };
434
435 static void setup_branch_path(struct branch_info *branch)
436 {
437 struct strbuf buf = STRBUF_INIT;
438
439 strbuf_branchname(&buf, branch->name);
440 if (strcmp(buf.buf, branch->name))
441 branch->name = xstrdup(buf.buf);
442 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
443 branch->path = strbuf_detach(&buf, NULL);
444 }
445
446 static int merge_working_tree(const struct checkout_opts *opts,
447 struct branch_info *old,
448 struct branch_info *new,
449 int *writeout_error)
450 {
451 int ret;
452 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
453 int newfd = hold_locked_index(lock_file, 1);
454
455 if (read_cache_preload(NULL) < 0)
456 return error(_("corrupt index file"));
457
458 resolve_undo_clear();
459 if (opts->force) {
460 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
461 if (ret)
462 return ret;
463 } else {
464 struct tree_desc trees[2];
465 struct tree *tree;
466 struct unpack_trees_options topts;
467
468 memset(&topts, 0, sizeof(topts));
469 topts.head_idx = -1;
470 topts.src_index = &the_index;
471 topts.dst_index = &the_index;
472
473 setup_unpack_trees_porcelain(&topts, "checkout");
474
475 refresh_cache(REFRESH_QUIET);
476
477 if (unmerged_cache()) {
478 error(_("you need to resolve your current index first"));
479 return 1;
480 }
481
482 /* 2-way merge to the new branch */
483 topts.initial_checkout = is_cache_unborn();
484 topts.update = 1;
485 topts.merge = 1;
486 topts.gently = opts->merge && old->commit;
487 topts.verbose_update = !opts->quiet && isatty(2);
488 topts.fn = twoway_merge;
489 if (opts->overwrite_ignore) {
490 topts.dir = xcalloc(1, sizeof(*topts.dir));
491 topts.dir->flags |= DIR_SHOW_IGNORED;
492 setup_standard_excludes(topts.dir);
493 }
494 tree = parse_tree_indirect(old->commit ?
495 old->commit->object.sha1 :
496 EMPTY_TREE_SHA1_BIN);
497 init_tree_desc(&trees[0], tree->buffer, tree->size);
498 tree = parse_tree_indirect(new->commit->object.sha1);
499 init_tree_desc(&trees[1], tree->buffer, tree->size);
500
501 ret = unpack_trees(2, trees, &topts);
502 if (ret == -1) {
503 /*
504 * Unpack couldn't do a trivial merge; either
505 * give up or do a real merge, depending on
506 * whether the merge flag was used.
507 */
508 struct tree *result;
509 struct tree *work;
510 struct merge_options o;
511 if (!opts->merge)
512 return 1;
513
514 /*
515 * Without old->commit, the below is the same as
516 * the two-tree unpack we already tried and failed.
517 */
518 if (!old->commit)
519 return 1;
520
521 /* Do more real merge */
522
523 /*
524 * We update the index fully, then write the
525 * tree from the index, then merge the new
526 * branch with the current tree, with the old
527 * branch as the base. Then we reset the index
528 * (but not the working tree) to the new
529 * branch, leaving the working tree as the
530 * merged version, but skipping unmerged
531 * entries in the index.
532 */
533
534 add_files_to_cache(NULL, NULL, 0);
535 /*
536 * NEEDSWORK: carrying over local changes
537 * when branches have different end-of-line
538 * normalization (or clean+smudge rules) is
539 * a pain; plumb in an option to set
540 * o.renormalize?
541 */
542 init_merge_options(&o);
543 o.verbosity = 0;
544 work = write_tree_from_memory(&o);
545
546 ret = reset_tree(new->commit->tree, opts, 1,
547 writeout_error);
548 if (ret)
549 return ret;
550 o.ancestor = old->name;
551 o.branch1 = new->name;
552 o.branch2 = "local";
553 merge_trees(&o, new->commit->tree, work,
554 old->commit->tree, &result);
555 ret = reset_tree(new->commit->tree, opts, 0,
556 writeout_error);
557 if (ret)
558 return ret;
559 }
560 }
561
562 if (write_cache(newfd, active_cache, active_nr) ||
563 commit_locked_index(lock_file))
564 die(_("unable to write new index file"));
565
566 if (!opts->force && !opts->quiet)
567 show_local_changes(&new->commit->object, &opts->diff_options);
568
569 return 0;
570 }
571
572 static void report_tracking(struct branch_info *new)
573 {
574 struct strbuf sb = STRBUF_INIT;
575 struct branch *branch = branch_get(new->name);
576
577 if (!format_tracking_info(branch, &sb))
578 return;
579 fputs(sb.buf, stdout);
580 strbuf_release(&sb);
581 }
582
583 static void update_refs_for_switch(const struct checkout_opts *opts,
584 struct branch_info *old,
585 struct branch_info *new)
586 {
587 struct strbuf msg = STRBUF_INIT;
588 const char *old_desc, *reflog_msg;
589 if (opts->new_branch) {
590 if (opts->new_orphan_branch) {
591 if (opts->new_branch_log && !log_all_ref_updates) {
592 int temp;
593 char log_file[PATH_MAX];
594 char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
595
596 temp = log_all_ref_updates;
597 log_all_ref_updates = 1;
598 if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
599 fprintf(stderr, _("Can not do reflog for '%s'\n"),
600 opts->new_orphan_branch);
601 log_all_ref_updates = temp;
602 return;
603 }
604 log_all_ref_updates = temp;
605 }
606 }
607 else
608 create_branch(old->name, opts->new_branch, new->name,
609 opts->new_branch_force ? 1 : 0,
610 opts->new_branch_log,
611 opts->new_branch_force ? 1 : 0,
612 opts->quiet,
613 opts->track);
614 new->name = opts->new_branch;
615 setup_branch_path(new);
616 }
617
618 old_desc = old->name;
619 if (!old_desc && old->commit)
620 old_desc = sha1_to_hex(old->commit->object.sha1);
621
622 reflog_msg = getenv("GIT_REFLOG_ACTION");
623 if (!reflog_msg)
624 strbuf_addf(&msg, "checkout: moving from %s to %s",
625 old_desc ? old_desc : "(invalid)", new->name);
626 else
627 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
628
629 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
630 /* Nothing to do. */
631 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
632 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
633 REF_NODEREF, DIE_ON_ERR);
634 if (!opts->quiet) {
635 if (old->path && advice_detached_head)
636 detach_advice(new->name);
637 describe_detached_head(_("HEAD is now at"), new->commit);
638 }
639 } else if (new->path) { /* Switch branches. */
640 create_symref("HEAD", new->path, msg.buf);
641 if (!opts->quiet) {
642 if (old->path && !strcmp(new->path, old->path)) {
643 if (opts->new_branch_force)
644 fprintf(stderr, _("Reset branch '%s'\n"),
645 new->name);
646 else
647 fprintf(stderr, _("Already on '%s'\n"),
648 new->name);
649 } else if (opts->new_branch) {
650 if (opts->branch_exists)
651 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
652 else
653 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
654 } else {
655 fprintf(stderr, _("Switched to branch '%s'\n"),
656 new->name);
657 }
658 }
659 if (old->path && old->name) {
660 char log_file[PATH_MAX], ref_file[PATH_MAX];
661
662 git_snpath(log_file, sizeof(log_file), "logs/%s", old->path);
663 git_snpath(ref_file, sizeof(ref_file), "%s", old->path);
664 if (!file_exists(ref_file) && file_exists(log_file))
665 remove_path(log_file);
666 }
667 }
668 remove_branch_state();
669 strbuf_release(&msg);
670 if (!opts->quiet &&
671 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
672 report_tracking(new);
673 }
674
675 static int add_pending_uninteresting_ref(const char *refname,
676 const unsigned char *sha1,
677 int flags, void *cb_data)
678 {
679 add_pending_sha1(cb_data, refname, sha1, UNINTERESTING);
680 return 0;
681 }
682
683 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
684 {
685 parse_commit(commit);
686 strbuf_addstr(sb, " ");
687 strbuf_addstr(sb,
688 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
689 strbuf_addch(sb, ' ');
690 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
691 strbuf_addch(sb, '\n');
692 }
693
694 #define ORPHAN_CUTOFF 4
695 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
696 {
697 struct commit *c, *last = NULL;
698 struct strbuf sb = STRBUF_INIT;
699 int lost = 0;
700 while ((c = get_revision(revs)) != NULL) {
701 if (lost < ORPHAN_CUTOFF)
702 describe_one_orphan(&sb, c);
703 last = c;
704 lost++;
705 }
706 if (ORPHAN_CUTOFF < lost) {
707 int more = lost - ORPHAN_CUTOFF;
708 if (more == 1)
709 describe_one_orphan(&sb, last);
710 else
711 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
712 }
713
714 fprintf(stderr,
715 Q_(
716 /* The singular version */
717 "Warning: you are leaving %d commit behind, "
718 "not connected to\n"
719 "any of your branches:\n\n"
720 "%s\n",
721 /* The plural version */
722 "Warning: you are leaving %d commits behind, "
723 "not connected to\n"
724 "any of your branches:\n\n"
725 "%s\n",
726 /* Give ngettext() the count */
727 lost),
728 lost,
729 sb.buf);
730 strbuf_release(&sb);
731
732 if (advice_detached_head)
733 fprintf(stderr,
734 _(
735 "If you want to keep them by creating a new branch, "
736 "this may be a good time\nto do so with:\n\n"
737 " git branch new_branch_name %s\n\n"),
738 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
739 }
740
741 /*
742 * We are about to leave commit that was at the tip of a detached
743 * HEAD. If it is not reachable from any ref, this is the last chance
744 * for the user to do so without resorting to reflog.
745 */
746 static void orphaned_commit_warning(struct commit *old, struct commit *new)
747 {
748 struct rev_info revs;
749 struct object *object = &old->object;
750 struct object_array refs;
751
752 init_revisions(&revs, NULL);
753 setup_revisions(0, NULL, &revs, NULL);
754
755 object->flags &= ~UNINTERESTING;
756 add_pending_object(&revs, object, sha1_to_hex(object->sha1));
757
758 for_each_ref(add_pending_uninteresting_ref, &revs);
759 add_pending_sha1(&revs, "HEAD", new->object.sha1, UNINTERESTING);
760
761 refs = revs.pending;
762 revs.leak_pending = 1;
763
764 if (prepare_revision_walk(&revs))
765 die(_("internal error in revision walk"));
766 if (!(old->object.flags & UNINTERESTING))
767 suggest_reattach(old, &revs);
768 else
769 describe_detached_head(_("Previous HEAD position was"), old);
770
771 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
772 free(refs.objects);
773 }
774
775 static int switch_branches(const struct checkout_opts *opts,
776 struct branch_info *new)
777 {
778 int ret = 0;
779 struct branch_info old;
780 void *path_to_free;
781 unsigned char rev[20];
782 int flag, writeout_error = 0;
783 memset(&old, 0, sizeof(old));
784 old.path = path_to_free = resolve_refdup("HEAD", rev, 0, &flag);
785 old.commit = lookup_commit_reference_gently(rev, 1);
786 if (!(flag & REF_ISSYMREF))
787 old.path = NULL;
788
789 if (old.path && !prefixcmp(old.path, "refs/heads/"))
790 old.name = old.path + strlen("refs/heads/");
791
792 if (!new->name) {
793 new->name = "HEAD";
794 new->commit = old.commit;
795 if (!new->commit)
796 die(_("You are on a branch yet to be born"));
797 parse_commit(new->commit);
798 }
799
800 ret = merge_working_tree(opts, &old, new, &writeout_error);
801 if (ret) {
802 free(path_to_free);
803 return ret;
804 }
805
806 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
807 orphaned_commit_warning(old.commit, new->commit);
808
809 update_refs_for_switch(opts, &old, new);
810
811 ret = post_checkout_hook(old.commit, new->commit, 1);
812 free(path_to_free);
813 return ret || writeout_error;
814 }
815
816 static int git_checkout_config(const char *var, const char *value, void *cb)
817 {
818 if (!strcmp(var, "diff.ignoresubmodules")) {
819 struct checkout_opts *opts = cb;
820 handle_ignore_submodules_arg(&opts->diff_options, value);
821 return 0;
822 }
823
824 if (!prefixcmp(var, "submodule."))
825 return parse_submodule_config_option(var, value);
826
827 return git_xmerge_config(var, value, NULL);
828 }
829
830 struct tracking_name_data {
831 /* const */ char *src_ref;
832 char *dst_ref;
833 unsigned char *dst_sha1;
834 int unique;
835 };
836
837 static int check_tracking_name(struct remote *remote, void *cb_data)
838 {
839 struct tracking_name_data *cb = cb_data;
840 struct refspec query;
841 memset(&query, 0, sizeof(struct refspec));
842 query.src = cb->src_ref;
843 if (remote_find_tracking(remote, &query) ||
844 get_sha1(query.dst, cb->dst_sha1)) {
845 free(query.dst);
846 return 0;
847 }
848 if (cb->dst_ref) {
849 free(query.dst);
850 cb->unique = 0;
851 return 0;
852 }
853 cb->dst_ref = query.dst;
854 return 0;
855 }
856
857 static const char *unique_tracking_name(const char *name, unsigned char *sha1)
858 {
859 struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
860 char src_ref[PATH_MAX];
861 snprintf(src_ref, PATH_MAX, "refs/heads/%s", name);
862 cb_data.src_ref = src_ref;
863 cb_data.dst_sha1 = sha1;
864 for_each_remote(check_tracking_name, &cb_data);
865 if (cb_data.unique)
866 return cb_data.dst_ref;
867 free(cb_data.dst_ref);
868 return NULL;
869 }
870
871 static int parse_branchname_arg(int argc, const char **argv,
872 int dwim_new_local_branch_ok,
873 struct branch_info *new,
874 struct tree **source_tree,
875 unsigned char rev[20],
876 const char **new_branch)
877 {
878 int argcount = 0;
879 unsigned char branch_rev[20];
880 const char *arg;
881 int has_dash_dash;
882
883 /*
884 * case 1: git checkout <ref> -- [<paths>]
885 *
886 * <ref> must be a valid tree, everything after the '--' must be
887 * a path.
888 *
889 * case 2: git checkout -- [<paths>]
890 *
891 * everything after the '--' must be paths.
892 *
893 * case 3: git checkout <something> [<paths>]
894 *
895 * With no paths, if <something> is a commit, that is to
896 * switch to the branch or detach HEAD at it. As a special case,
897 * if <something> is A...B (missing A or B means HEAD but you can
898 * omit at most one side), and if there is a unique merge base
899 * between A and B, A...B names that merge base.
900 *
901 * With no paths, if <something> is _not_ a commit, no -t nor -b
902 * was given, and there is a tracking branch whose name is
903 * <something> in one and only one remote, then this is a short-hand
904 * to fork local <something> from that remote-tracking branch.
905 *
906 * Otherwise <something> shall not be ambiguous.
907 * - If it's *only* a reference, treat it like case (1).
908 * - If it's only a path, treat it like case (2).
909 * - else: fail.
910 *
911 */
912 if (!argc)
913 return 0;
914
915 if (!strcmp(argv[0], "--")) /* case (2) */
916 return 1;
917
918 arg = argv[0];
919 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
920
921 if (!strcmp(arg, "-"))
922 arg = "@{-1}";
923
924 if (get_sha1_mb(arg, rev)) {
925 if (has_dash_dash) /* case (1) */
926 die(_("invalid reference: %s"), arg);
927 if (dwim_new_local_branch_ok &&
928 !check_filename(NULL, arg) &&
929 argc == 1) {
930 const char *remote = unique_tracking_name(arg, rev);
931 if (!remote)
932 return argcount;
933 *new_branch = arg;
934 arg = remote;
935 /* DWIMmed to create local branch */
936 } else {
937 return argcount;
938 }
939 }
940
941 /* we can't end up being in (2) anymore, eat the argument */
942 argcount++;
943 argv++;
944 argc--;
945
946 new->name = arg;
947 setup_branch_path(new);
948
949 if (!check_refname_format(new->path, 0) &&
950 !read_ref(new->path, branch_rev))
951 hashcpy(rev, branch_rev);
952 else
953 new->path = NULL; /* not an existing branch */
954
955 new->commit = lookup_commit_reference_gently(rev, 1);
956 if (!new->commit) {
957 /* not a commit */
958 *source_tree = parse_tree_indirect(rev);
959 } else {
960 parse_commit(new->commit);
961 *source_tree = new->commit->tree;
962 }
963
964 if (!*source_tree) /* case (1): want a tree */
965 die(_("reference is not a tree: %s"), arg);
966 if (!has_dash_dash) {/* case (3 -> 1) */
967 /*
968 * Do not complain the most common case
969 * git checkout branch
970 * even if there happen to be a file called 'branch';
971 * it would be extremely annoying.
972 */
973 if (argc)
974 verify_non_filename(NULL, arg);
975 } else {
976 argcount++;
977 argv++;
978 argc--;
979 }
980
981 return argcount;
982 }
983
984 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
985 {
986 int status;
987 struct strbuf branch_ref = STRBUF_INIT;
988
989 if (!opts->new_branch)
990 die(_("You are on a branch yet to be born"));
991 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
992 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
993 strbuf_release(&branch_ref);
994 if (!opts->quiet)
995 fprintf(stderr, _("Switched to a new branch '%s'\n"),
996 opts->new_branch);
997 return status;
998 }
999
1000 static int checkout_branch(struct checkout_opts *opts,
1001 struct branch_info *new)
1002 {
1003 if (opts->pathspec.nr)
1004 die(_("paths cannot be used with switching branches"));
1005
1006 if (opts->patch_mode)
1007 die(_("'%s' cannot be used with switching branches"),
1008 "--patch");
1009
1010 if (opts->writeout_stage)
1011 die(_("'%s' cannot be used with switching branches"),
1012 "--ours/--theirs");
1013
1014 if (opts->force && opts->merge)
1015 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1016
1017 if (opts->force_detach && opts->new_branch)
1018 die(_("'%s' cannot be used with '%s'"),
1019 "--detach", "-b/-B/--orphan");
1020
1021 if (opts->new_orphan_branch) {
1022 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1023 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1024 } else if (opts->force_detach) {
1025 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1026 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1027 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1028 opts->track = git_branch_track;
1029
1030 if (new->name && !new->commit)
1031 die(_("Cannot switch branch to a non-commit '%s'"),
1032 new->name);
1033
1034 if (!new->commit && opts->new_branch) {
1035 unsigned char rev[20];
1036 int flag;
1037
1038 if (!read_ref_full("HEAD", rev, 0, &flag) &&
1039 (flag & REF_ISSYMREF) && is_null_sha1(rev))
1040 return switch_unborn_to_new_branch(opts);
1041 }
1042 return switch_branches(opts, new);
1043 }
1044
1045 int cmd_checkout(int argc, const char **argv, const char *prefix)
1046 {
1047 struct checkout_opts opts;
1048 struct branch_info new;
1049 char *conflict_style = NULL;
1050 int dwim_new_local_branch = 1;
1051 struct option options[] = {
1052 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1053 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1054 N_("create and checkout a new branch")),
1055 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1056 N_("create/reset and checkout a branch")),
1057 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1058 OPT_BOOLEAN(0, "detach", &opts.force_detach, N_("detach the HEAD at named commit")),
1059 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1060 BRANCH_TRACK_EXPLICIT),
1061 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new branch"), N_("new unparented branch")),
1062 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1063 2),
1064 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1065 3),
1066 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1067 OPT_BOOLEAN('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1068 OPT_BOOLEAN(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1069 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1070 N_("conflict style (merge or diff3)")),
1071 OPT_BOOLEAN('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1072 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1073 N_("do not limit pathspecs to sparse entries only")),
1074 { OPTION_BOOLEAN, 0, "guess", &dwim_new_local_branch, NULL,
1075 N_("second guess 'git checkout no-such-branch'"),
1076 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
1077 OPT_END(),
1078 };
1079
1080 memset(&opts, 0, sizeof(opts));
1081 memset(&new, 0, sizeof(new));
1082 opts.overwrite_ignore = 1;
1083 opts.prefix = prefix;
1084
1085 gitmodules_config();
1086 git_config(git_checkout_config, &opts);
1087
1088 opts.track = BRANCH_TRACK_UNSPECIFIED;
1089
1090 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1091 PARSE_OPT_KEEP_DASHDASH);
1092
1093 if (conflict_style) {
1094 opts.merge = 1; /* implied */
1095 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1096 }
1097
1098 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1099 die(_("-b, -B and --orphan are mutually exclusive"));
1100
1101 /*
1102 * From here on, new_branch will contain the branch to be checked out,
1103 * and new_branch_force and new_orphan_branch will tell us which one of
1104 * -b/-B/--orphan is being used.
1105 */
1106 if (opts.new_branch_force)
1107 opts.new_branch = opts.new_branch_force;
1108
1109 if (opts.new_orphan_branch)
1110 opts.new_branch = opts.new_orphan_branch;
1111
1112 /* --track without -b/-B/--orphan should DWIM */
1113 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1114 const char *argv0 = argv[0];
1115 if (!argc || !strcmp(argv0, "--"))
1116 die (_("--track needs a branch name"));
1117 if (!prefixcmp(argv0, "refs/"))
1118 argv0 += 5;
1119 if (!prefixcmp(argv0, "remotes/"))
1120 argv0 += 8;
1121 argv0 = strchr(argv0, '/');
1122 if (!argv0 || !argv0[1])
1123 die (_("Missing branch name; try -b"));
1124 opts.new_branch = argv0 + 1;
1125 }
1126
1127 /*
1128 * Extract branch name from command line arguments, so
1129 * all that is left is pathspecs.
1130 *
1131 * Handle
1132 *
1133 * 1) git checkout <tree> -- [<paths>]
1134 * 2) git checkout -- [<paths>]
1135 * 3) git checkout <something> [<paths>]
1136 *
1137 * including "last branch" syntax and DWIM-ery for names of
1138 * remote branches, erroring out for invalid or ambiguous cases.
1139 */
1140 if (argc) {
1141 unsigned char rev[20];
1142 int dwim_ok =
1143 !opts.patch_mode &&
1144 dwim_new_local_branch &&
1145 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1146 !opts.new_branch;
1147 int n = parse_branchname_arg(argc, argv, dwim_ok,
1148 &new, &opts.source_tree,
1149 rev, &opts.new_branch);
1150 argv += n;
1151 argc -= n;
1152 }
1153
1154 if (argc) {
1155 /*
1156 * In patch mode (opts.patch_mode != 0), we pass the
1157 * pathspec to an external program, git-add--interactive.
1158 * Do not accept any kind of magic that that program
1159 * cannot handle. Magic mask is pretty safe to be
1160 * lifted for new magic when opts.patch_mode == 0.
1161 */
1162 parse_pathspec(&opts.pathspec,
1163 opts.patch_mode == 0 ? 0 :
1164 (PATHSPEC_ALL_MAGIC & ~PATHSPEC_FROMTOP),
1165 0, prefix, argv);
1166
1167 if (!opts.pathspec.nr)
1168 die(_("invalid path specification"));
1169
1170 /*
1171 * Try to give more helpful suggestion.
1172 * new_branch && argc > 1 will be caught later.
1173 */
1174 if (opts.new_branch && argc == 1)
1175 die(_("Cannot update paths and switch to branch '%s' at the same time.\n"
1176 "Did you intend to checkout '%s' which can not be resolved as commit?"),
1177 opts.new_branch, argv[0]);
1178
1179 if (opts.force_detach)
1180 die(_("git checkout: --detach does not take a path argument '%s'"),
1181 argv[0]);
1182
1183 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1184 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1185 "checking out of the index."));
1186 }
1187
1188 if (opts.new_branch) {
1189 struct strbuf buf = STRBUF_INIT;
1190
1191 opts.branch_exists =
1192 validate_new_branchname(opts.new_branch, &buf,
1193 !!opts.new_branch_force,
1194 !!opts.new_branch_force);
1195
1196 strbuf_release(&buf);
1197 }
1198
1199 if (opts.patch_mode || opts.pathspec.nr)
1200 return checkout_paths(&opts, new.name);
1201 else
1202 return checkout_branch(&opts, &new);
1203 }