9240fafb2ad17505bf407363e058d208a8a70497
[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
23 static const char * const checkout_usage[] = {
24 "git checkout [options] <branch>",
25 "git checkout [options] [<branch>] -- <file>...",
26 NULL,
27 };
28
29 struct checkout_opts {
30 int quiet;
31 int merge;
32 int force;
33 int writeout_stage;
34 int writeout_error;
35
36 /* not set by parse_options */
37 int branch_exists;
38
39 const char *new_branch;
40 const char *new_branch_force;
41 const char *new_orphan_branch;
42 int new_branch_log;
43 enum branch_track track;
44 struct diff_options diff_options;
45 };
46
47 static int post_checkout_hook(struct commit *old, struct commit *new,
48 int changed)
49 {
50 return run_hook(NULL, "post-checkout",
51 sha1_to_hex(old ? old->object.sha1 : null_sha1),
52 sha1_to_hex(new ? new->object.sha1 : null_sha1),
53 changed ? "1" : "0", NULL);
54 /* "new" can be NULL when checking out from the index before
55 a commit exists. */
56
57 }
58
59 static int update_some(const unsigned char *sha1, const char *base, int baselen,
60 const char *pathname, unsigned mode, int stage, void *context)
61 {
62 int len;
63 struct cache_entry *ce;
64
65 if (S_ISDIR(mode))
66 return READ_TREE_RECURSIVE;
67
68 len = baselen + strlen(pathname);
69 ce = xcalloc(1, cache_entry_size(len));
70 hashcpy(ce->sha1, sha1);
71 memcpy(ce->name, base, baselen);
72 memcpy(ce->name + baselen, pathname, len - baselen);
73 ce->ce_flags = create_ce_flags(len, 0);
74 ce->ce_mode = create_ce_mode(mode);
75 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
76 return 0;
77 }
78
79 static int read_tree_some(struct tree *tree, const char **pathspec)
80 {
81 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
82
83 /* update the index with the given tree's info
84 * for all args, expanding wildcards, and exit
85 * with any non-zero return code.
86 */
87 return 0;
88 }
89
90 static int skip_same_name(struct cache_entry *ce, int pos)
91 {
92 while (++pos < active_nr &&
93 !strcmp(active_cache[pos]->name, ce->name))
94 ; /* skip */
95 return pos;
96 }
97
98 static int check_stage(int stage, struct cache_entry *ce, int pos)
99 {
100 while (pos < active_nr &&
101 !strcmp(active_cache[pos]->name, ce->name)) {
102 if (ce_stage(active_cache[pos]) == stage)
103 return 0;
104 pos++;
105 }
106 return error("path '%s' does not have %s version",
107 ce->name,
108 (stage == 2) ? "our" : "their");
109 }
110
111 static int check_all_stages(struct cache_entry *ce, int pos)
112 {
113 if (ce_stage(ce) != 1 ||
114 active_nr <= pos + 2 ||
115 strcmp(active_cache[pos+1]->name, ce->name) ||
116 ce_stage(active_cache[pos+1]) != 2 ||
117 strcmp(active_cache[pos+2]->name, ce->name) ||
118 ce_stage(active_cache[pos+2]) != 3)
119 return error("path '%s' does not have all three versions",
120 ce->name);
121 return 0;
122 }
123
124 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
125 struct checkout *state)
126 {
127 while (pos < active_nr &&
128 !strcmp(active_cache[pos]->name, ce->name)) {
129 if (ce_stage(active_cache[pos]) == stage)
130 return checkout_entry(active_cache[pos], state, NULL);
131 pos++;
132 }
133 return error("path '%s' does not have %s version",
134 ce->name,
135 (stage == 2) ? "our" : "their");
136 }
137
138 static int checkout_merged(int pos, struct checkout *state)
139 {
140 struct cache_entry *ce = active_cache[pos];
141 const char *path = ce->name;
142 mmfile_t ancestor, ours, theirs;
143 int status;
144 unsigned char sha1[20];
145 mmbuffer_t result_buf;
146
147 if (ce_stage(ce) != 1 ||
148 active_nr <= pos + 2 ||
149 strcmp(active_cache[pos+1]->name, path) ||
150 ce_stage(active_cache[pos+1]) != 2 ||
151 strcmp(active_cache[pos+2]->name, path) ||
152 ce_stage(active_cache[pos+2]) != 3)
153 return error("path '%s' does not have all 3 versions", path);
154
155 read_mmblob(&ancestor, active_cache[pos]->sha1);
156 read_mmblob(&ours, active_cache[pos+1]->sha1);
157 read_mmblob(&theirs, active_cache[pos+2]->sha1);
158
159 /*
160 * NEEDSWORK: re-create conflicts from merges with
161 * merge.renormalize set, too
162 */
163 status = ll_merge(&result_buf, path, &ancestor, "base",
164 &ours, "ours", &theirs, "theirs", NULL);
165 free(ancestor.ptr);
166 free(ours.ptr);
167 free(theirs.ptr);
168 if (status < 0 || !result_buf.ptr) {
169 free(result_buf.ptr);
170 return error("path '%s': cannot merge", path);
171 }
172
173 /*
174 * NEEDSWORK:
175 * There is absolutely no reason to write this as a blob object
176 * and create a phony cache entry just to leak. This hack is
177 * primarily to get to the write_entry() machinery that massages
178 * the contents to work-tree format and writes out which only
179 * allows it for a cache entry. The code in write_entry() needs
180 * to be refactored to allow us to feed a <buffer, size, mode>
181 * instead of a cache entry. Such a refactoring would help
182 * merge_recursive as well (it also writes the merge result to the
183 * object database even when it may contain conflicts).
184 */
185 if (write_sha1_file(result_buf.ptr, result_buf.size,
186 blob_type, sha1))
187 die("Unable to add merge result for '%s'", path);
188 ce = make_cache_entry(create_ce_mode(active_cache[pos+1]->ce_mode),
189 sha1,
190 path, 2, 0);
191 if (!ce)
192 die("make_cache_entry failed for path '%s'", path);
193 status = checkout_entry(ce, state, NULL);
194 return status;
195 }
196
197 static int checkout_paths(struct tree *source_tree, const char **pathspec,
198 struct checkout_opts *opts)
199 {
200 int pos;
201 struct checkout state;
202 static char *ps_matched;
203 unsigned char rev[20];
204 int flag;
205 struct commit *head;
206 int errs = 0;
207 int stage = opts->writeout_stage;
208 int merge = opts->merge;
209 int newfd;
210 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
211
212 newfd = hold_locked_index(lock_file, 1);
213 if (read_cache_preload(pathspec) < 0)
214 return error("corrupt index file");
215
216 if (source_tree)
217 read_tree_some(source_tree, pathspec);
218
219 for (pos = 0; pathspec[pos]; pos++)
220 ;
221 ps_matched = xcalloc(1, pos);
222
223 for (pos = 0; pos < active_nr; pos++) {
224 struct cache_entry *ce = active_cache[pos];
225 match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, ps_matched);
226 }
227
228 if (report_path_error(ps_matched, pathspec, 0))
229 return 1;
230
231 /* "checkout -m path" to recreate conflicted state */
232 if (opts->merge)
233 unmerge_cache(pathspec);
234
235 /* Any unmerged paths? */
236 for (pos = 0; pos < active_nr; pos++) {
237 struct cache_entry *ce = active_cache[pos];
238 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
239 if (!ce_stage(ce))
240 continue;
241 if (opts->force) {
242 warning("path '%s' is unmerged", ce->name);
243 } else if (stage) {
244 errs |= check_stage(stage, ce, pos);
245 } else if (opts->merge) {
246 errs |= check_all_stages(ce, pos);
247 } else {
248 errs = 1;
249 error("path '%s' is unmerged", ce->name);
250 }
251 pos = skip_same_name(ce, pos) - 1;
252 }
253 }
254 if (errs)
255 return 1;
256
257 /* Now we are committed to check them out */
258 memset(&state, 0, sizeof(state));
259 state.force = 1;
260 state.refresh_cache = 1;
261 for (pos = 0; pos < active_nr; pos++) {
262 struct cache_entry *ce = active_cache[pos];
263 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
264 if (!ce_stage(ce)) {
265 errs |= checkout_entry(ce, &state, NULL);
266 continue;
267 }
268 if (stage)
269 errs |= checkout_stage(stage, ce, pos, &state);
270 else if (merge)
271 errs |= checkout_merged(pos, &state);
272 pos = skip_same_name(ce, pos) - 1;
273 }
274 }
275
276 if (write_cache(newfd, active_cache, active_nr) ||
277 commit_locked_index(lock_file))
278 die("unable to write new index file");
279
280 resolve_ref("HEAD", rev, 0, &flag);
281 head = lookup_commit_reference_gently(rev, 1);
282
283 errs |= post_checkout_hook(head, head, 0);
284 return errs;
285 }
286
287 static void show_local_changes(struct object *head, struct diff_options *opts)
288 {
289 struct rev_info rev;
290 /* I think we want full paths, even if we're in a subdirectory. */
291 init_revisions(&rev, NULL);
292 rev.diffopt.flags = opts->flags;
293 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
294 if (diff_setup_done(&rev.diffopt) < 0)
295 die("diff_setup_done failed");
296 add_pending_object(&rev, head, NULL);
297 run_diff_index(&rev, 0);
298 }
299
300 static void describe_detached_head(char *msg, struct commit *commit)
301 {
302 struct strbuf sb = STRBUF_INIT;
303 struct pretty_print_context ctx = {0};
304 parse_commit(commit);
305 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, &ctx);
306 fprintf(stderr, "%s %s... %s\n", msg,
307 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
308 strbuf_release(&sb);
309 }
310
311 static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
312 {
313 struct unpack_trees_options opts;
314 struct tree_desc tree_desc;
315
316 memset(&opts, 0, sizeof(opts));
317 opts.head_idx = -1;
318 opts.update = worktree;
319 opts.skip_unmerged = !worktree;
320 opts.reset = 1;
321 opts.merge = 1;
322 opts.fn = oneway_merge;
323 opts.verbose_update = !o->quiet;
324 opts.src_index = &the_index;
325 opts.dst_index = &the_index;
326 parse_tree(tree);
327 init_tree_desc(&tree_desc, tree->buffer, tree->size);
328 switch (unpack_trees(1, &tree_desc, &opts)) {
329 case -2:
330 o->writeout_error = 1;
331 /*
332 * We return 0 nevertheless, as the index is all right
333 * and more importantly we have made best efforts to
334 * update paths in the work tree, and we cannot revert
335 * them.
336 */
337 case 0:
338 return 0;
339 default:
340 return 128;
341 }
342 }
343
344 struct branch_info {
345 const char *name; /* The short name used */
346 const char *path; /* The full name of a real branch */
347 struct commit *commit; /* The named commit */
348 };
349
350 static void setup_branch_path(struct branch_info *branch)
351 {
352 struct strbuf buf = STRBUF_INIT;
353
354 strbuf_branchname(&buf, branch->name);
355 if (strcmp(buf.buf, branch->name))
356 branch->name = xstrdup(buf.buf);
357 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
358 branch->path = strbuf_detach(&buf, NULL);
359 }
360
361 static int merge_working_tree(struct checkout_opts *opts,
362 struct branch_info *old, struct branch_info *new)
363 {
364 int ret;
365 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
366 int newfd = hold_locked_index(lock_file, 1);
367
368 if (read_cache_preload(NULL) < 0)
369 return error("corrupt index file");
370
371 resolve_undo_clear();
372 if (opts->force) {
373 ret = reset_tree(new->commit->tree, opts, 1);
374 if (ret)
375 return ret;
376 } else {
377 struct tree_desc trees[2];
378 struct tree *tree;
379 struct unpack_trees_options topts;
380
381 memset(&topts, 0, sizeof(topts));
382 topts.head_idx = -1;
383 topts.src_index = &the_index;
384 topts.dst_index = &the_index;
385
386 setup_unpack_trees_porcelain(&topts, "checkout");
387
388 refresh_cache(REFRESH_QUIET);
389
390 if (unmerged_cache()) {
391 error("you need to resolve your current index first");
392 return 1;
393 }
394
395 /* 2-way merge to the new branch */
396 topts.initial_checkout = is_cache_unborn();
397 topts.update = 1;
398 topts.merge = 1;
399 topts.gently = opts->merge && old->commit;
400 topts.verbose_update = !opts->quiet;
401 topts.fn = twoway_merge;
402 topts.dir = xcalloc(1, sizeof(*topts.dir));
403 topts.dir->flags |= DIR_SHOW_IGNORED;
404 topts.dir->exclude_per_dir = ".gitignore";
405 tree = parse_tree_indirect(old->commit ?
406 old->commit->object.sha1 :
407 (unsigned char *)EMPTY_TREE_SHA1_BIN);
408 init_tree_desc(&trees[0], tree->buffer, tree->size);
409 tree = parse_tree_indirect(new->commit->object.sha1);
410 init_tree_desc(&trees[1], tree->buffer, tree->size);
411
412 ret = unpack_trees(2, trees, &topts);
413 if (ret == -1) {
414 /*
415 * Unpack couldn't do a trivial merge; either
416 * give up or do a real merge, depending on
417 * whether the merge flag was used.
418 */
419 struct tree *result;
420 struct tree *work;
421 struct merge_options o;
422 if (!opts->merge)
423 return 1;
424
425 /*
426 * Without old->commit, the below is the same as
427 * the two-tree unpack we already tried and failed.
428 */
429 if (!old->commit)
430 return 1;
431
432 /* Do more real merge */
433
434 /*
435 * We update the index fully, then write the
436 * tree from the index, then merge the new
437 * branch with the current tree, with the old
438 * branch as the base. Then we reset the index
439 * (but not the working tree) to the new
440 * branch, leaving the working tree as the
441 * merged version, but skipping unmerged
442 * entries in the index.
443 */
444
445 add_files_to_cache(NULL, NULL, 0);
446 /*
447 * NEEDSWORK: carrying over local changes
448 * when branches have different end-of-line
449 * normalization (or clean+smudge rules) is
450 * a pain; plumb in an option to set
451 * o.renormalize?
452 */
453 init_merge_options(&o);
454 o.verbosity = 0;
455 work = write_tree_from_memory(&o);
456
457 ret = reset_tree(new->commit->tree, opts, 1);
458 if (ret)
459 return ret;
460 o.ancestor = old->name;
461 o.branch1 = new->name;
462 o.branch2 = "local";
463 merge_trees(&o, new->commit->tree, work,
464 old->commit->tree, &result);
465 ret = reset_tree(new->commit->tree, opts, 0);
466 if (ret)
467 return ret;
468 }
469 }
470
471 if (write_cache(newfd, active_cache, active_nr) ||
472 commit_locked_index(lock_file))
473 die("unable to write new index file");
474
475 if (!opts->force && !opts->quiet)
476 show_local_changes(&new->commit->object, &opts->diff_options);
477
478 return 0;
479 }
480
481 static void report_tracking(struct branch_info *new)
482 {
483 struct strbuf sb = STRBUF_INIT;
484 struct branch *branch = branch_get(new->name);
485
486 if (!format_tracking_info(branch, &sb))
487 return;
488 fputs(sb.buf, stdout);
489 strbuf_release(&sb);
490 }
491
492 static void detach_advice(const char *old_path, const char *new_name)
493 {
494 const char fmt[] =
495 "Note: checking out '%s'.\n\n"
496 "You are in 'detached HEAD' state. You can look around, make experimental\n"
497 "changes and commit them, and you can discard any commits you make in this\n"
498 "state without impacting any branches by performing another checkout.\n\n"
499 "If you want to create a new branch to retain commits you create, you may\n"
500 "do so (now or later) by using -b with the checkout command again. Example:\n\n"
501 " git checkout -b new_branch_name\n\n";
502
503 fprintf(stderr, fmt, new_name);
504 }
505
506 static void update_refs_for_switch(struct checkout_opts *opts,
507 struct branch_info *old,
508 struct branch_info *new)
509 {
510 struct strbuf msg = STRBUF_INIT;
511 const char *old_desc;
512 if (opts->new_branch) {
513 if (opts->new_orphan_branch) {
514 if (opts->new_branch_log && !log_all_ref_updates) {
515 int temp;
516 char log_file[PATH_MAX];
517 char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
518
519 temp = log_all_ref_updates;
520 log_all_ref_updates = 1;
521 if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
522 fprintf(stderr, "Can not do reflog for '%s'\n",
523 opts->new_orphan_branch);
524 log_all_ref_updates = temp;
525 return;
526 }
527 log_all_ref_updates = temp;
528 }
529 }
530 else
531 create_branch(old->name, opts->new_branch, new->name,
532 opts->new_branch_force ? 1 : 0,
533 opts->new_branch_log, opts->track);
534 new->name = opts->new_branch;
535 setup_branch_path(new);
536 }
537
538 old_desc = old->name;
539 if (!old_desc && old->commit)
540 old_desc = sha1_to_hex(old->commit->object.sha1);
541 strbuf_addf(&msg, "checkout: moving from %s to %s",
542 old_desc ? old_desc : "(invalid)", new->name);
543
544 if (new->path) {
545 create_symref("HEAD", new->path, msg.buf);
546 if (!opts->quiet) {
547 if (old->path && !strcmp(new->path, old->path))
548 fprintf(stderr, "Already on '%s'\n",
549 new->name);
550 else if (opts->new_branch)
551 fprintf(stderr, "Switched to%s branch '%s'\n",
552 opts->branch_exists ? " and reset" : " a new",
553 new->name);
554 else
555 fprintf(stderr, "Switched to branch '%s'\n",
556 new->name);
557 }
558 if (old->path && old->name) {
559 char log_file[PATH_MAX], ref_file[PATH_MAX];
560
561 git_snpath(log_file, sizeof(log_file), "logs/%s", old->path);
562 git_snpath(ref_file, sizeof(ref_file), "%s", old->path);
563 if (!file_exists(ref_file) && file_exists(log_file))
564 remove_path(log_file);
565 }
566 } else if (strcmp(new->name, "HEAD")) {
567 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
568 REF_NODEREF, DIE_ON_ERR);
569 if (!opts->quiet) {
570 if (old->path && advice_detached_head)
571 detach_advice(old->path, new->name);
572 describe_detached_head("HEAD is now at", new->commit);
573 }
574 }
575 remove_branch_state();
576 strbuf_release(&msg);
577 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
578 report_tracking(new);
579 }
580
581 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
582 {
583 int ret = 0;
584 struct branch_info old;
585 unsigned char rev[20];
586 int flag;
587 memset(&old, 0, sizeof(old));
588 old.path = resolve_ref("HEAD", rev, 0, &flag);
589 old.commit = lookup_commit_reference_gently(rev, 1);
590 if (!(flag & REF_ISSYMREF))
591 old.path = NULL;
592
593 if (old.path && !prefixcmp(old.path, "refs/heads/"))
594 old.name = old.path + strlen("refs/heads/");
595
596 if (!new->name) {
597 new->name = "HEAD";
598 new->commit = old.commit;
599 if (!new->commit)
600 die("You are on a branch yet to be born");
601 parse_commit(new->commit);
602 }
603
604 ret = merge_working_tree(opts, &old, new);
605 if (ret)
606 return ret;
607
608 /*
609 * If we were on a detached HEAD, but have now moved to
610 * a new commit, we want to mention the old commit once more
611 * to remind the user that it might be lost.
612 */
613 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
614 describe_detached_head("Previous HEAD position was", old.commit);
615
616 update_refs_for_switch(opts, &old, new);
617
618 ret = post_checkout_hook(old.commit, new->commit, 1);
619 return ret || opts->writeout_error;
620 }
621
622 static int git_checkout_config(const char *var, const char *value, void *cb)
623 {
624 if (!strcmp(var, "diff.ignoresubmodules")) {
625 struct checkout_opts *opts = cb;
626 handle_ignore_submodules_arg(&opts->diff_options, value);
627 return 0;
628 }
629
630 if (!prefixcmp(var, "submodule."))
631 return parse_submodule_config_option(var, value);
632
633 return git_xmerge_config(var, value, NULL);
634 }
635
636 static int interactive_checkout(const char *revision, const char **pathspec,
637 struct checkout_opts *opts)
638 {
639 return run_add_interactive(revision, "--patch=checkout", pathspec);
640 }
641
642 struct tracking_name_data {
643 const char *name;
644 char *remote;
645 int unique;
646 };
647
648 static int check_tracking_name(const char *refname, const unsigned char *sha1,
649 int flags, void *cb_data)
650 {
651 struct tracking_name_data *cb = cb_data;
652 const char *slash;
653
654 if (prefixcmp(refname, "refs/remotes/"))
655 return 0;
656 slash = strchr(refname + 13, '/');
657 if (!slash || strcmp(slash + 1, cb->name))
658 return 0;
659 if (cb->remote) {
660 cb->unique = 0;
661 return 0;
662 }
663 cb->remote = xstrdup(refname);
664 return 0;
665 }
666
667 static const char *unique_tracking_name(const char *name)
668 {
669 struct tracking_name_data cb_data = { NULL, NULL, 1 };
670 cb_data.name = name;
671 for_each_ref(check_tracking_name, &cb_data);
672 if (cb_data.unique)
673 return cb_data.remote;
674 free(cb_data.remote);
675 return NULL;
676 }
677
678 int cmd_checkout(int argc, const char **argv, const char *prefix)
679 {
680 struct checkout_opts opts;
681 unsigned char rev[20];
682 const char *arg;
683 struct branch_info new;
684 struct tree *source_tree = NULL;
685 char *conflict_style = NULL;
686 int patch_mode = 0;
687 int dwim_new_local_branch = 1;
688 struct option options[] = {
689 OPT__QUIET(&opts.quiet),
690 OPT_STRING('b', NULL, &opts.new_branch, "branch",
691 "create and checkout a new branch"),
692 OPT_STRING('B', NULL, &opts.new_branch_force, "branch",
693 "create/reset and checkout a branch"),
694 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "create reflog for new branch"),
695 OPT_SET_INT('t', "track", &opts.track, "set upstream info for new branch",
696 BRANCH_TRACK_EXPLICIT),
697 OPT_STRING(0, "orphan", &opts.new_orphan_branch, "new branch", "new unparented branch"),
698 OPT_SET_INT('2', "ours", &opts.writeout_stage, "checkout our version for unmerged files",
699 2),
700 OPT_SET_INT('3', "theirs", &opts.writeout_stage, "checkout their version for unmerged files",
701 3),
702 OPT_BOOLEAN('f', "force", &opts.force, "force checkout (throw away local modifications)"),
703 OPT_BOOLEAN('m', "merge", &opts.merge, "perform a 3-way merge with the new branch"),
704 OPT_STRING(0, "conflict", &conflict_style, "style",
705 "conflict style (merge or diff3)"),
706 OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
707 { OPTION_BOOLEAN, 0, "guess", &dwim_new_local_branch, NULL,
708 "second guess 'git checkout no-such-branch'",
709 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
710 OPT_END(),
711 };
712 int has_dash_dash;
713
714 memset(&opts, 0, sizeof(opts));
715 memset(&new, 0, sizeof(new));
716
717 gitmodules_config();
718 git_config(git_checkout_config, &opts);
719
720 opts.track = BRANCH_TRACK_UNSPECIFIED;
721
722 argc = parse_options(argc, argv, prefix, options, checkout_usage,
723 PARSE_OPT_KEEP_DASHDASH);
724
725 /* we can assume from now on new_branch = !new_branch_force */
726 if (opts.new_branch && opts.new_branch_force)
727 die("-B cannot be used with -b");
728
729 /* copy -B over to -b, so that we can just check the latter */
730 if (opts.new_branch_force)
731 opts.new_branch = opts.new_branch_force;
732
733 if (patch_mode && (opts.track > 0 || opts.new_branch
734 || opts.new_branch_log || opts.merge || opts.force))
735 die ("--patch is incompatible with all other options");
736
737 /* --track without -b should DWIM */
738 if (0 < opts.track && !opts.new_branch) {
739 const char *argv0 = argv[0];
740 if (!argc || !strcmp(argv0, "--"))
741 die ("--track needs a branch name");
742 if (!prefixcmp(argv0, "refs/"))
743 argv0 += 5;
744 if (!prefixcmp(argv0, "remotes/"))
745 argv0 += 8;
746 argv0 = strchr(argv0, '/');
747 if (!argv0 || !argv0[1])
748 die ("Missing branch name; try -b");
749 opts.new_branch = argv0 + 1;
750 }
751
752 if (opts.new_orphan_branch) {
753 if (opts.new_branch)
754 die("--orphan and -b|-B are mutually exclusive");
755 if (opts.track > 0)
756 die("--orphan cannot be used with -t");
757 opts.new_branch = opts.new_orphan_branch;
758 }
759
760 if (conflict_style) {
761 opts.merge = 1; /* implied */
762 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
763 }
764
765 if (opts.force && opts.merge)
766 die("git checkout: -f and -m are incompatible");
767
768 /*
769 * case 1: git checkout <ref> -- [<paths>]
770 *
771 * <ref> must be a valid tree, everything after the '--' must be
772 * a path.
773 *
774 * case 2: git checkout -- [<paths>]
775 *
776 * everything after the '--' must be paths.
777 *
778 * case 3: git checkout <something> [<paths>]
779 *
780 * With no paths, if <something> is a commit, that is to
781 * switch to the branch or detach HEAD at it. As a special case,
782 * if <something> is A...B (missing A or B means HEAD but you can
783 * omit at most one side), and if there is a unique merge base
784 * between A and B, A...B names that merge base.
785 *
786 * With no paths, if <something> is _not_ a commit, no -t nor -b
787 * was given, and there is a tracking branch whose name is
788 * <something> in one and only one remote, then this is a short-hand
789 * to fork local <something> from that remote tracking branch.
790 *
791 * Otherwise <something> shall not be ambiguous.
792 * - If it's *only* a reference, treat it like case (1).
793 * - If it's only a path, treat it like case (2).
794 * - else: fail.
795 *
796 */
797 if (argc) {
798 if (!strcmp(argv[0], "--")) { /* case (2) */
799 argv++;
800 argc--;
801 goto no_reference;
802 }
803
804 arg = argv[0];
805 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
806
807 if (!strcmp(arg, "-"))
808 arg = "@{-1}";
809
810 if (get_sha1_mb(arg, rev)) {
811 if (has_dash_dash) /* case (1) */
812 die("invalid reference: %s", arg);
813 if (!patch_mode &&
814 dwim_new_local_branch &&
815 opts.track == BRANCH_TRACK_UNSPECIFIED &&
816 !opts.new_branch &&
817 !check_filename(NULL, arg) &&
818 argc == 1) {
819 const char *remote = unique_tracking_name(arg);
820 if (!remote || get_sha1(remote, rev))
821 goto no_reference;
822 opts.new_branch = arg;
823 arg = remote;
824 /* DWIMmed to create local branch */
825 }
826 else
827 goto no_reference;
828 }
829
830 /* we can't end up being in (2) anymore, eat the argument */
831 argv++;
832 argc--;
833
834 new.name = arg;
835 if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
836 setup_branch_path(&new);
837
838 if ((check_ref_format(new.path) == CHECK_REF_FORMAT_OK) &&
839 resolve_ref(new.path, rev, 1, NULL))
840 ;
841 else
842 new.path = NULL;
843 parse_commit(new.commit);
844 source_tree = new.commit->tree;
845 } else
846 source_tree = parse_tree_indirect(rev);
847
848 if (!source_tree) /* case (1): want a tree */
849 die("reference is not a tree: %s", arg);
850 if (!has_dash_dash) {/* case (3 -> 1) */
851 /*
852 * Do not complain the most common case
853 * git checkout branch
854 * even if there happen to be a file called 'branch';
855 * it would be extremely annoying.
856 */
857 if (argc)
858 verify_non_filename(NULL, arg);
859 }
860 else {
861 argv++;
862 argc--;
863 }
864 }
865
866 no_reference:
867
868 if (opts.track == BRANCH_TRACK_UNSPECIFIED)
869 opts.track = git_branch_track;
870
871 if (argc) {
872 const char **pathspec = get_pathspec(prefix, argv);
873
874 if (!pathspec)
875 die("invalid path specification");
876
877 if (patch_mode)
878 return interactive_checkout(new.name, pathspec, &opts);
879
880 /* Checkout paths */
881 if (opts.new_branch) {
882 if (argc == 1) {
883 die("git checkout: updating paths is incompatible with switching branches.\nDid you intend to checkout '%s' which can not be resolved as commit?", argv[0]);
884 } else {
885 die("git checkout: updating paths is incompatible with switching branches.");
886 }
887 }
888
889 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
890 die("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index.");
891
892 return checkout_paths(source_tree, pathspec, &opts);
893 }
894
895 if (patch_mode)
896 return interactive_checkout(new.name, NULL, &opts);
897
898 if (opts.new_branch) {
899 struct strbuf buf = STRBUF_INIT;
900 if (strbuf_check_branch_ref(&buf, opts.new_branch))
901 die("git checkout: we do not like '%s' as a branch name.",
902 opts.new_branch);
903 if (!get_sha1(buf.buf, rev)) {
904 opts.branch_exists = 1;
905 if (!opts.new_branch_force)
906 die("git checkout: branch %s already exists",
907 opts.new_branch);
908 }
909 strbuf_release(&buf);
910 }
911
912 if (new.name && !new.commit) {
913 die("Cannot switch branch to a non-commit.");
914 }
915 if (opts.writeout_stage)
916 die("--ours/--theirs is incompatible with switching branches.");
917
918 return switch_branches(&opts, &new);
919 }