Merge branch 'maint-1.6.1' into maint
[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 "unpack-trees.h"
9 #include "dir.h"
10 #include "run-command.h"
11 #include "merge-recursive.h"
12 #include "branch.h"
13 #include "diff.h"
14 #include "revision.h"
15 #include "remote.h"
16 #include "blob.h"
17 #include "xdiff-interface.h"
18 #include "ll-merge.h"
19
20 static const char * const checkout_usage[] = {
21 "git checkout [options] <branch>",
22 "git checkout [options] [<branch>] -- <file>...",
23 NULL,
24 };
25
26 struct checkout_opts {
27 int quiet;
28 int merge;
29 int force;
30 int writeout_stage;
31 int writeout_error;
32
33 const char *new_branch;
34 int new_branch_log;
35 enum branch_track track;
36 };
37
38 static int post_checkout_hook(struct commit *old, struct commit *new,
39 int changed)
40 {
41 return run_hook(NULL, "post-checkout",
42 sha1_to_hex(old ? old->object.sha1 : null_sha1),
43 sha1_to_hex(new ? new->object.sha1 : null_sha1),
44 changed ? "1" : "0", NULL);
45 /* "new" can be NULL when checking out from the index before
46 a commit exists. */
47
48 }
49
50 static int update_some(const unsigned char *sha1, const char *base, int baselen,
51 const char *pathname, unsigned mode, int stage, void *context)
52 {
53 int len;
54 struct cache_entry *ce;
55
56 if (S_ISDIR(mode))
57 return READ_TREE_RECURSIVE;
58
59 len = baselen + strlen(pathname);
60 ce = xcalloc(1, cache_entry_size(len));
61 hashcpy(ce->sha1, sha1);
62 memcpy(ce->name, base, baselen);
63 memcpy(ce->name + baselen, pathname, len - baselen);
64 ce->ce_flags = create_ce_flags(len, 0);
65 ce->ce_mode = create_ce_mode(mode);
66 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
67 return 0;
68 }
69
70 static int read_tree_some(struct tree *tree, const char **pathspec)
71 {
72 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
73
74 /* update the index with the given tree's info
75 * for all args, expanding wildcards, and exit
76 * with any non-zero return code.
77 */
78 return 0;
79 }
80
81 static int skip_same_name(struct cache_entry *ce, int pos)
82 {
83 while (++pos < active_nr &&
84 !strcmp(active_cache[pos]->name, ce->name))
85 ; /* skip */
86 return pos;
87 }
88
89 static int check_stage(int stage, struct cache_entry *ce, int pos)
90 {
91 while (pos < active_nr &&
92 !strcmp(active_cache[pos]->name, ce->name)) {
93 if (ce_stage(active_cache[pos]) == stage)
94 return 0;
95 pos++;
96 }
97 return error("path '%s' does not have %s version",
98 ce->name,
99 (stage == 2) ? "our" : "their");
100 }
101
102 static int check_all_stages(struct cache_entry *ce, int pos)
103 {
104 if (ce_stage(ce) != 1 ||
105 active_nr <= pos + 2 ||
106 strcmp(active_cache[pos+1]->name, ce->name) ||
107 ce_stage(active_cache[pos+1]) != 2 ||
108 strcmp(active_cache[pos+2]->name, ce->name) ||
109 ce_stage(active_cache[pos+2]) != 3)
110 return error("path '%s' does not have all three versions",
111 ce->name);
112 return 0;
113 }
114
115 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
116 struct checkout *state)
117 {
118 while (pos < active_nr &&
119 !strcmp(active_cache[pos]->name, ce->name)) {
120 if (ce_stage(active_cache[pos]) == stage)
121 return checkout_entry(active_cache[pos], state, NULL);
122 pos++;
123 }
124 return error("path '%s' does not have %s version",
125 ce->name,
126 (stage == 2) ? "our" : "their");
127 }
128
129 /* NEEDSWORK: share with merge-recursive */
130 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
131 {
132 unsigned long size;
133 enum object_type type;
134
135 if (!hashcmp(sha1, null_sha1)) {
136 mm->ptr = xstrdup("");
137 mm->size = 0;
138 return;
139 }
140
141 mm->ptr = read_sha1_file(sha1, &type, &size);
142 if (!mm->ptr || type != OBJ_BLOB)
143 die("unable to read blob object %s", sha1_to_hex(sha1));
144 mm->size = size;
145 }
146
147 static int checkout_merged(int pos, struct checkout *state)
148 {
149 struct cache_entry *ce = active_cache[pos];
150 const char *path = ce->name;
151 mmfile_t ancestor, ours, theirs;
152 int status;
153 unsigned char sha1[20];
154 mmbuffer_t result_buf;
155
156 if (ce_stage(ce) != 1 ||
157 active_nr <= pos + 2 ||
158 strcmp(active_cache[pos+1]->name, path) ||
159 ce_stage(active_cache[pos+1]) != 2 ||
160 strcmp(active_cache[pos+2]->name, path) ||
161 ce_stage(active_cache[pos+2]) != 3)
162 return error("path '%s' does not have all 3 versions", path);
163
164 fill_mm(active_cache[pos]->sha1, &ancestor);
165 fill_mm(active_cache[pos+1]->sha1, &ours);
166 fill_mm(active_cache[pos+2]->sha1, &theirs);
167
168 status = ll_merge(&result_buf, path, &ancestor,
169 &ours, "ours", &theirs, "theirs", 1);
170 free(ancestor.ptr);
171 free(ours.ptr);
172 free(theirs.ptr);
173 if (status < 0 || !result_buf.ptr) {
174 free(result_buf.ptr);
175 return error("path '%s': cannot merge", path);
176 }
177
178 /*
179 * NEEDSWORK:
180 * There is absolutely no reason to write this as a blob object
181 * and create a phoney cache entry just to leak. This hack is
182 * primarily to get to the write_entry() machinery that massages
183 * the contents to work-tree format and writes out which only
184 * allows it for a cache entry. The code in write_entry() needs
185 * to be refactored to allow us to feed a <buffer, size, mode>
186 * instead of a cache entry. Such a refactoring would help
187 * merge_recursive as well (it also writes the merge result to the
188 * object database even when it may contain conflicts).
189 */
190 if (write_sha1_file(result_buf.ptr, result_buf.size,
191 blob_type, sha1))
192 die("Unable to add merge result for '%s'", path);
193 ce = make_cache_entry(create_ce_mode(active_cache[pos+1]->ce_mode),
194 sha1,
195 path, 2, 0);
196 if (!ce)
197 die("make_cache_entry failed for path '%s'", path);
198 status = checkout_entry(ce, state, NULL);
199 return status;
200 }
201
202 static int checkout_paths(struct tree *source_tree, const char **pathspec,
203 struct checkout_opts *opts)
204 {
205 int pos;
206 struct checkout state;
207 static char *ps_matched;
208 unsigned char rev[20];
209 int flag;
210 struct commit *head;
211 int errs = 0;
212 int stage = opts->writeout_stage;
213 int merge = opts->merge;
214 int newfd;
215 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
216
217 newfd = hold_locked_index(lock_file, 1);
218 if (read_cache() < 0)
219 return error("corrupt index file");
220
221 if (source_tree)
222 read_tree_some(source_tree, pathspec);
223
224 for (pos = 0; pathspec[pos]; pos++)
225 ;
226 ps_matched = xcalloc(1, pos);
227
228 for (pos = 0; pos < active_nr; pos++) {
229 struct cache_entry *ce = active_cache[pos];
230 match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, ps_matched);
231 }
232
233 if (report_path_error(ps_matched, pathspec, 0))
234 return 1;
235
236 /* Any unmerged paths? */
237 for (pos = 0; pos < active_nr; pos++) {
238 struct cache_entry *ce = active_cache[pos];
239 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
240 if (!ce_stage(ce))
241 continue;
242 if (opts->force) {
243 warning("path '%s' is unmerged", ce->name);
244 } else if (stage) {
245 errs |= check_stage(stage, ce, pos);
246 } else if (opts->merge) {
247 errs |= check_all_stages(ce, pos);
248 } else {
249 errs = 1;
250 error("path '%s' is unmerged", ce->name);
251 }
252 pos = skip_same_name(ce, pos) - 1;
253 }
254 }
255 if (errs)
256 return 1;
257
258 /* Now we are committed to check them out */
259 memset(&state, 0, sizeof(state));
260 state.force = 1;
261 state.refresh_cache = 1;
262 for (pos = 0; pos < active_nr; pos++) {
263 struct cache_entry *ce = active_cache[pos];
264 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
265 if (!ce_stage(ce)) {
266 errs |= checkout_entry(ce, &state, NULL);
267 continue;
268 }
269 if (stage)
270 errs |= checkout_stage(stage, ce, pos, &state);
271 else if (merge)
272 errs |= checkout_merged(pos, &state);
273 pos = skip_same_name(ce, pos) - 1;
274 }
275 }
276
277 if (write_cache(newfd, active_cache, active_nr) ||
278 commit_locked_index(lock_file))
279 die("unable to write new index file");
280
281 resolve_ref("HEAD", rev, 0, &flag);
282 head = lookup_commit_reference_gently(rev, 1);
283
284 errs |= post_checkout_hook(head, head, 0);
285 return errs;
286 }
287
288 static void show_local_changes(struct object *head)
289 {
290 struct rev_info rev;
291 /* I think we want full paths, even if we're in a subdirectory. */
292 init_revisions(&rev, NULL);
293 rev.abbrev = 0;
294 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
295 add_pending_object(&rev, head, NULL);
296 run_diff_index(&rev, 0);
297 }
298
299 static void describe_detached_head(char *msg, struct commit *commit)
300 {
301 struct strbuf sb = STRBUF_INIT;
302 parse_commit(commit);
303 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
304 fprintf(stderr, "%s %s... %s\n", msg,
305 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
306 strbuf_release(&sb);
307 }
308
309 static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
310 {
311 struct unpack_trees_options opts;
312 struct tree_desc tree_desc;
313
314 memset(&opts, 0, sizeof(opts));
315 opts.head_idx = -1;
316 opts.update = worktree;
317 opts.skip_unmerged = !worktree;
318 opts.reset = 1;
319 opts.merge = 1;
320 opts.fn = oneway_merge;
321 opts.verbose_update = !o->quiet;
322 opts.src_index = &the_index;
323 opts.dst_index = &the_index;
324 parse_tree(tree);
325 init_tree_desc(&tree_desc, tree->buffer, tree->size);
326 switch (unpack_trees(1, &tree_desc, &opts)) {
327 case -2:
328 o->writeout_error = 1;
329 /*
330 * We return 0 nevertheless, as the index is all right
331 * and more importantly we have made best efforts to
332 * update paths in the work tree, and we cannot revert
333 * them.
334 */
335 case 0:
336 return 0;
337 default:
338 return 128;
339 }
340 }
341
342 struct branch_info {
343 const char *name; /* The short name used */
344 const char *path; /* The full name of a real branch */
345 struct commit *commit; /* The named commit */
346 };
347
348 static void setup_branch_path(struct branch_info *branch)
349 {
350 struct strbuf buf = STRBUF_INIT;
351 int ret;
352
353 if ((ret = interpret_nth_last_branch(branch->name, &buf))
354 && ret == strlen(branch->name)) {
355 branch->name = xstrdup(buf.buf);
356 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
357 } else {
358 strbuf_addstr(&buf, "refs/heads/");
359 strbuf_addstr(&buf, branch->name);
360 }
361 branch->path = strbuf_detach(&buf, NULL);
362 }
363
364 static int merge_working_tree(struct checkout_opts *opts,
365 struct branch_info *old, struct branch_info *new)
366 {
367 int ret;
368 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
369 int newfd = hold_locked_index(lock_file, 1);
370
371 if (read_cache() < 0)
372 return error("corrupt index file");
373
374 if (opts->force) {
375 ret = reset_tree(new->commit->tree, opts, 1);
376 if (ret)
377 return ret;
378 } else {
379 struct tree_desc trees[2];
380 struct tree *tree;
381 struct unpack_trees_options topts;
382
383 memset(&topts, 0, sizeof(topts));
384 topts.head_idx = -1;
385 topts.src_index = &the_index;
386 topts.dst_index = &the_index;
387
388 topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
389
390 refresh_cache(REFRESH_QUIET);
391
392 if (unmerged_cache()) {
393 error("you need to resolve your current index first");
394 return 1;
395 }
396
397 /* 2-way merge to the new branch */
398 topts.initial_checkout = is_cache_unborn();
399 topts.update = 1;
400 topts.merge = 1;
401 topts.gently = opts->merge;
402 topts.verbose_update = !opts->quiet;
403 topts.fn = twoway_merge;
404 topts.dir = xcalloc(1, sizeof(*topts.dir));
405 topts.dir->show_ignored = 1;
406 topts.dir->exclude_per_dir = ".gitignore";
407 tree = parse_tree_indirect(old->commit->object.sha1);
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 parse_commit(old->commit);
425
426 /* Do more real merge */
427
428 /*
429 * We update the index fully, then write the
430 * tree from the index, then merge the new
431 * branch with the current tree, with the old
432 * branch as the base. Then we reset the index
433 * (but not the working tree) to the new
434 * branch, leaving the working tree as the
435 * merged version, but skipping unmerged
436 * entries in the index.
437 */
438
439 add_files_to_cache(NULL, NULL, 0);
440 init_merge_options(&o);
441 o.verbosity = 0;
442 work = write_tree_from_memory(&o);
443
444 ret = reset_tree(new->commit->tree, opts, 1);
445 if (ret)
446 return ret;
447 o.branch1 = new->name;
448 o.branch2 = "local";
449 merge_trees(&o, new->commit->tree, work,
450 old->commit->tree, &result);
451 ret = reset_tree(new->commit->tree, opts, 0);
452 if (ret)
453 return ret;
454 }
455 }
456
457 if (write_cache(newfd, active_cache, active_nr) ||
458 commit_locked_index(lock_file))
459 die("unable to write new index file");
460
461 if (!opts->force && !opts->quiet)
462 show_local_changes(&new->commit->object);
463
464 return 0;
465 }
466
467 static void report_tracking(struct branch_info *new)
468 {
469 struct strbuf sb = STRBUF_INIT;
470 struct branch *branch = branch_get(new->name);
471
472 if (!format_tracking_info(branch, &sb))
473 return;
474 fputs(sb.buf, stdout);
475 strbuf_release(&sb);
476 }
477
478 static void update_refs_for_switch(struct checkout_opts *opts,
479 struct branch_info *old,
480 struct branch_info *new)
481 {
482 struct strbuf msg = STRBUF_INIT;
483 const char *old_desc;
484 if (opts->new_branch) {
485 create_branch(old->name, opts->new_branch, new->name, 0,
486 opts->new_branch_log, opts->track);
487 new->name = opts->new_branch;
488 setup_branch_path(new);
489 }
490
491 old_desc = old->name;
492 if (!old_desc && old->commit)
493 old_desc = sha1_to_hex(old->commit->object.sha1);
494 strbuf_addf(&msg, "checkout: moving from %s to %s",
495 old_desc ? old_desc : "(invalid)", new->name);
496
497 if (new->path) {
498 create_symref("HEAD", new->path, msg.buf);
499 if (!opts->quiet) {
500 if (old->path && !strcmp(new->path, old->path))
501 fprintf(stderr, "Already on '%s'\n",
502 new->name);
503 else
504 fprintf(stderr, "Switched to%s branch '%s'\n",
505 opts->new_branch ? " a new" : "",
506 new->name);
507 }
508 } else if (strcmp(new->name, "HEAD")) {
509 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
510 REF_NODEREF, DIE_ON_ERR);
511 if (!opts->quiet) {
512 if (old->path)
513 fprintf(stderr, "Note: moving to '%s' which isn't a local branch\nIf you want to create a new branch from this checkout, you may do so\n(now or later) by using -b with the checkout command again. Example:\n git checkout -b <new_branch_name>\n", new->name);
514 describe_detached_head("HEAD is now at", new->commit);
515 }
516 }
517 remove_branch_state();
518 strbuf_release(&msg);
519 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
520 report_tracking(new);
521 }
522
523 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
524 {
525 int ret = 0;
526 struct branch_info old;
527 unsigned char rev[20];
528 int flag;
529 memset(&old, 0, sizeof(old));
530 old.path = resolve_ref("HEAD", rev, 0, &flag);
531 old.commit = lookup_commit_reference_gently(rev, 1);
532 if (!(flag & REF_ISSYMREF))
533 old.path = NULL;
534
535 if (old.path && !prefixcmp(old.path, "refs/heads/"))
536 old.name = old.path + strlen("refs/heads/");
537
538 if (!new->name) {
539 new->name = "HEAD";
540 new->commit = old.commit;
541 if (!new->commit)
542 die("You are on a branch yet to be born");
543 parse_commit(new->commit);
544 }
545
546 /*
547 * If we were on a detached HEAD, but we are now moving to
548 * a new commit, we want to mention the old commit once more
549 * to remind the user that it might be lost.
550 */
551 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
552 describe_detached_head("Previous HEAD position was", old.commit);
553
554 if (!old.commit && !opts->force) {
555 if (!opts->quiet) {
556 fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
557 fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
558 }
559 opts->force = 1;
560 }
561
562 ret = merge_working_tree(opts, &old, new);
563 if (ret)
564 return ret;
565
566 update_refs_for_switch(opts, &old, new);
567
568 ret = post_checkout_hook(old.commit, new->commit, 1);
569 return ret || opts->writeout_error;
570 }
571
572 static int git_checkout_config(const char *var, const char *value, void *cb)
573 {
574 return git_xmerge_config(var, value, cb);
575 }
576
577 int cmd_checkout(int argc, const char **argv, const char *prefix)
578 {
579 struct checkout_opts opts;
580 unsigned char rev[20];
581 const char *arg;
582 struct branch_info new;
583 struct tree *source_tree = NULL;
584 char *conflict_style = NULL;
585 struct option options[] = {
586 OPT__QUIET(&opts.quiet),
587 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
588 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
589 OPT_SET_INT('t', "track", &opts.track, "track",
590 BRANCH_TRACK_EXPLICIT),
591 OPT_SET_INT('2', "ours", &opts.writeout_stage, "stage",
592 2),
593 OPT_SET_INT('3', "theirs", &opts.writeout_stage, "stage",
594 3),
595 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
596 OPT_BOOLEAN('m', "merge", &opts.merge, "merge"),
597 OPT_STRING(0, "conflict", &conflict_style, "style",
598 "conflict style (merge or diff3)"),
599 OPT_END(),
600 };
601 int has_dash_dash;
602
603 memset(&opts, 0, sizeof(opts));
604 memset(&new, 0, sizeof(new));
605
606 git_config(git_checkout_config, NULL);
607
608 opts.track = BRANCH_TRACK_UNSPECIFIED;
609
610 argc = parse_options(argc, argv, options, checkout_usage,
611 PARSE_OPT_KEEP_DASHDASH);
612
613 /* --track without -b should DWIM */
614 if (0 < opts.track && !opts.new_branch) {
615 const char *argv0 = argv[0];
616 if (!argc || !strcmp(argv0, "--"))
617 die ("--track needs a branch name");
618 if (!prefixcmp(argv0, "refs/"))
619 argv0 += 5;
620 if (!prefixcmp(argv0, "remotes/"))
621 argv0 += 8;
622 argv0 = strchr(argv0, '/');
623 if (!argv0 || !argv0[1])
624 die ("Missing branch name; try -b");
625 opts.new_branch = argv0 + 1;
626 }
627
628 if (opts.track == BRANCH_TRACK_UNSPECIFIED)
629 opts.track = git_branch_track;
630 if (conflict_style) {
631 opts.merge = 1; /* implied */
632 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
633 }
634
635 if (opts.force && opts.merge)
636 die("git checkout: -f and -m are incompatible");
637
638 /*
639 * case 1: git checkout <ref> -- [<paths>]
640 *
641 * <ref> must be a valid tree, everything after the '--' must be
642 * a path.
643 *
644 * case 2: git checkout -- [<paths>]
645 *
646 * everything after the '--' must be paths.
647 *
648 * case 3: git checkout <something> [<paths>]
649 *
650 * With no paths, if <something> is a commit, that is to
651 * switch to the branch or detach HEAD at it.
652 *
653 * Otherwise <something> shall not be ambiguous.
654 * - If it's *only* a reference, treat it like case (1).
655 * - If it's only a path, treat it like case (2).
656 * - else: fail.
657 *
658 */
659 if (argc) {
660 if (!strcmp(argv[0], "--")) { /* case (2) */
661 argv++;
662 argc--;
663 goto no_reference;
664 }
665
666 arg = argv[0];
667 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
668
669 if (!strcmp(arg, "-"))
670 arg = "@{-1}";
671
672 if (get_sha1(arg, rev)) {
673 if (has_dash_dash) /* case (1) */
674 die("invalid reference: %s", arg);
675 goto no_reference; /* case (3 -> 2) */
676 }
677
678 /* we can't end up being in (2) anymore, eat the argument */
679 argv++;
680 argc--;
681
682 new.name = arg;
683 if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
684 setup_branch_path(&new);
685 if (resolve_ref(new.path, rev, 1, NULL))
686 new.commit = lookup_commit_reference(rev);
687 else
688 new.path = NULL;
689 parse_commit(new.commit);
690 source_tree = new.commit->tree;
691 } else
692 source_tree = parse_tree_indirect(rev);
693
694 if (!source_tree) /* case (1): want a tree */
695 die("reference is not a tree: %s", arg);
696 if (!has_dash_dash) {/* case (3 -> 1) */
697 /*
698 * Do not complain the most common case
699 * git checkout branch
700 * even if there happen to be a file called 'branch';
701 * it would be extremely annoying.
702 */
703 if (argc)
704 verify_non_filename(NULL, arg);
705 }
706 else {
707 argv++;
708 argc--;
709 }
710 }
711
712 no_reference:
713 if (argc) {
714 const char **pathspec = get_pathspec(prefix, argv);
715
716 if (!pathspec)
717 die("invalid path specification");
718
719 /* Checkout paths */
720 if (opts.new_branch) {
721 if (argc == 1) {
722 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]);
723 } else {
724 die("git checkout: updating paths is incompatible with switching branches.");
725 }
726 }
727
728 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
729 die("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index.");
730
731 return checkout_paths(source_tree, pathspec, &opts);
732 }
733
734 if (opts.new_branch) {
735 struct strbuf buf = STRBUF_INIT;
736 strbuf_addstr(&buf, "refs/heads/");
737 strbuf_addstr(&buf, opts.new_branch);
738 if (!get_sha1(buf.buf, rev))
739 die("git checkout: branch %s already exists", opts.new_branch);
740 if (check_ref_format(buf.buf))
741 die("git checkout: we do not like '%s' as a branch name.", opts.new_branch);
742 strbuf_release(&buf);
743 }
744
745 if (new.name && !new.commit) {
746 die("Cannot switch branch to a non-commit.");
747 }
748 if (opts.writeout_stage)
749 die("--ours/--theirs is incompatible with switching branches.");
750
751 return switch_branches(&opts, &new);
752 }