Merge branch 'maint-1.6.0' into maint-1.6.1
[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 struct child_process proc;
42 const char *name = git_path("hooks/post-checkout");
43 const char *argv[5];
44
45 if (access(name, X_OK) < 0)
46 return 0;
47
48 memset(&proc, 0, sizeof(proc));
49 argv[0] = name;
50 argv[1] = xstrdup(sha1_to_hex(old ? old->object.sha1 : null_sha1));
51 argv[2] = xstrdup(sha1_to_hex(new->object.sha1));
52 argv[3] = changed ? "1" : "0";
53 argv[4] = NULL;
54 proc.argv = argv;
55 proc.no_stdin = 1;
56 proc.stdout_to_stderr = 1;
57 return run_command(&proc);
58 }
59
60 static int update_some(const unsigned char *sha1, const char *base, int baselen,
61 const char *pathname, unsigned mode, int stage, void *context)
62 {
63 int len;
64 struct cache_entry *ce;
65
66 if (S_ISGITLINK(mode))
67 return 0;
68
69 if (S_ISDIR(mode))
70 return READ_TREE_RECURSIVE;
71
72 len = baselen + strlen(pathname);
73 ce = xcalloc(1, cache_entry_size(len));
74 hashcpy(ce->sha1, sha1);
75 memcpy(ce->name, base, baselen);
76 memcpy(ce->name + baselen, pathname, len - baselen);
77 ce->ce_flags = create_ce_flags(len, 0);
78 ce->ce_mode = create_ce_mode(mode);
79 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
80 return 0;
81 }
82
83 static int read_tree_some(struct tree *tree, const char **pathspec)
84 {
85 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
86
87 /* update the index with the given tree's info
88 * for all args, expanding wildcards, and exit
89 * with any non-zero return code.
90 */
91 return 0;
92 }
93
94 static int skip_same_name(struct cache_entry *ce, int pos)
95 {
96 while (++pos < active_nr &&
97 !strcmp(active_cache[pos]->name, ce->name))
98 ; /* skip */
99 return pos;
100 }
101
102 static int check_stage(int stage, struct cache_entry *ce, int pos)
103 {
104 while (pos < active_nr &&
105 !strcmp(active_cache[pos]->name, ce->name)) {
106 if (ce_stage(active_cache[pos]) == stage)
107 return 0;
108 pos++;
109 }
110 return error("path '%s' does not have %s version",
111 ce->name,
112 (stage == 2) ? "our" : "their");
113 }
114
115 static int check_all_stages(struct cache_entry *ce, int pos)
116 {
117 if (ce_stage(ce) != 1 ||
118 active_nr <= pos + 2 ||
119 strcmp(active_cache[pos+1]->name, ce->name) ||
120 ce_stage(active_cache[pos+1]) != 2 ||
121 strcmp(active_cache[pos+2]->name, ce->name) ||
122 ce_stage(active_cache[pos+2]) != 3)
123 return error("path '%s' does not have all three versions",
124 ce->name);
125 return 0;
126 }
127
128 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
129 struct checkout *state)
130 {
131 while (pos < active_nr &&
132 !strcmp(active_cache[pos]->name, ce->name)) {
133 if (ce_stage(active_cache[pos]) == stage)
134 return checkout_entry(active_cache[pos], state, NULL);
135 pos++;
136 }
137 return error("path '%s' does not have %s version",
138 ce->name,
139 (stage == 2) ? "our" : "their");
140 }
141
142 /* NEEDSWORK: share with merge-recursive */
143 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
144 {
145 unsigned long size;
146 enum object_type type;
147
148 if (!hashcmp(sha1, null_sha1)) {
149 mm->ptr = xstrdup("");
150 mm->size = 0;
151 return;
152 }
153
154 mm->ptr = read_sha1_file(sha1, &type, &size);
155 if (!mm->ptr || type != OBJ_BLOB)
156 die("unable to read blob object %s", sha1_to_hex(sha1));
157 mm->size = size;
158 }
159
160 static int checkout_merged(int pos, struct checkout *state)
161 {
162 struct cache_entry *ce = active_cache[pos];
163 const char *path = ce->name;
164 mmfile_t ancestor, ours, theirs;
165 int status;
166 unsigned char sha1[20];
167 mmbuffer_t result_buf;
168
169 if (ce_stage(ce) != 1 ||
170 active_nr <= pos + 2 ||
171 strcmp(active_cache[pos+1]->name, path) ||
172 ce_stage(active_cache[pos+1]) != 2 ||
173 strcmp(active_cache[pos+2]->name, path) ||
174 ce_stage(active_cache[pos+2]) != 3)
175 return error("path '%s' does not have all 3 versions", path);
176
177 fill_mm(active_cache[pos]->sha1, &ancestor);
178 fill_mm(active_cache[pos+1]->sha1, &ours);
179 fill_mm(active_cache[pos+2]->sha1, &theirs);
180
181 status = ll_merge(&result_buf, path, &ancestor,
182 &ours, "ours", &theirs, "theirs", 1);
183 free(ancestor.ptr);
184 free(ours.ptr);
185 free(theirs.ptr);
186 if (status < 0 || !result_buf.ptr) {
187 free(result_buf.ptr);
188 return error("path '%s': cannot merge", path);
189 }
190
191 /*
192 * NEEDSWORK:
193 * There is absolutely no reason to write this as a blob object
194 * and create a phoney cache entry just to leak. This hack is
195 * primarily to get to the write_entry() machinery that massages
196 * the contents to work-tree format and writes out which only
197 * allows it for a cache entry. The code in write_entry() needs
198 * to be refactored to allow us to feed a <buffer, size, mode>
199 * instead of a cache entry. Such a refactoring would help
200 * merge_recursive as well (it also writes the merge result to the
201 * object database even when it may contain conflicts).
202 */
203 if (write_sha1_file(result_buf.ptr, result_buf.size,
204 blob_type, sha1))
205 die("Unable to add merge result for '%s'", path);
206 ce = make_cache_entry(create_ce_mode(active_cache[pos+1]->ce_mode),
207 sha1,
208 path, 2, 0);
209 if (!ce)
210 die("make_cache_entry failed for path '%s'", path);
211 status = checkout_entry(ce, state, NULL);
212 return status;
213 }
214
215 static int checkout_paths(struct tree *source_tree, const char **pathspec,
216 struct checkout_opts *opts)
217 {
218 int pos;
219 struct checkout state;
220 static char *ps_matched;
221 unsigned char rev[20];
222 int flag;
223 struct commit *head;
224 int errs = 0;
225 int stage = opts->writeout_stage;
226 int merge = opts->merge;
227 int newfd;
228 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
229
230 newfd = hold_locked_index(lock_file, 1);
231 if (read_cache() < 0)
232 return error("corrupt index file");
233
234 if (source_tree)
235 read_tree_some(source_tree, pathspec);
236
237 for (pos = 0; pathspec[pos]; pos++)
238 ;
239 ps_matched = xcalloc(1, pos);
240
241 for (pos = 0; pos < active_nr; pos++) {
242 struct cache_entry *ce = active_cache[pos];
243 pathspec_match(pathspec, ps_matched, ce->name, 0);
244 }
245
246 if (report_path_error(ps_matched, pathspec, 0))
247 return 1;
248
249 /* Any unmerged paths? */
250 for (pos = 0; pos < active_nr; pos++) {
251 struct cache_entry *ce = active_cache[pos];
252 if (pathspec_match(pathspec, NULL, ce->name, 0)) {
253 if (!ce_stage(ce))
254 continue;
255 if (opts->force) {
256 warning("path '%s' is unmerged", ce->name);
257 } else if (stage) {
258 errs |= check_stage(stage, ce, pos);
259 } else if (opts->merge) {
260 errs |= check_all_stages(ce, pos);
261 } else {
262 errs = 1;
263 error("path '%s' is unmerged", ce->name);
264 }
265 pos = skip_same_name(ce, pos) - 1;
266 }
267 }
268 if (errs)
269 return 1;
270
271 /* Now we are committed to check them out */
272 memset(&state, 0, sizeof(state));
273 state.force = 1;
274 state.refresh_cache = 1;
275 for (pos = 0; pos < active_nr; pos++) {
276 struct cache_entry *ce = active_cache[pos];
277 if (pathspec_match(pathspec, NULL, ce->name, 0)) {
278 if (!ce_stage(ce)) {
279 errs |= checkout_entry(ce, &state, NULL);
280 continue;
281 }
282 if (stage)
283 errs |= checkout_stage(stage, ce, pos, &state);
284 else if (merge)
285 errs |= checkout_merged(pos, &state);
286 pos = skip_same_name(ce, pos) - 1;
287 }
288 }
289
290 if (write_cache(newfd, active_cache, active_nr) ||
291 commit_locked_index(lock_file))
292 die("unable to write new index file");
293
294 resolve_ref("HEAD", rev, 0, &flag);
295 head = lookup_commit_reference_gently(rev, 1);
296
297 errs |= post_checkout_hook(head, head, 0);
298 return errs;
299 }
300
301 static void show_local_changes(struct object *head)
302 {
303 struct rev_info rev;
304 /* I think we want full paths, even if we're in a subdirectory. */
305 init_revisions(&rev, NULL);
306 rev.abbrev = 0;
307 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
308 add_pending_object(&rev, head, NULL);
309 run_diff_index(&rev, 0);
310 }
311
312 static void describe_detached_head(char *msg, struct commit *commit)
313 {
314 struct strbuf sb = STRBUF_INIT;
315 parse_commit(commit);
316 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
317 fprintf(stderr, "%s %s... %s\n", msg,
318 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
319 strbuf_release(&sb);
320 }
321
322 static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
323 {
324 struct unpack_trees_options opts;
325 struct tree_desc tree_desc;
326
327 memset(&opts, 0, sizeof(opts));
328 opts.head_idx = -1;
329 opts.update = worktree;
330 opts.skip_unmerged = !worktree;
331 opts.reset = 1;
332 opts.merge = 1;
333 opts.fn = oneway_merge;
334 opts.verbose_update = !o->quiet;
335 opts.src_index = &the_index;
336 opts.dst_index = &the_index;
337 parse_tree(tree);
338 init_tree_desc(&tree_desc, tree->buffer, tree->size);
339 switch (unpack_trees(1, &tree_desc, &opts)) {
340 case -2:
341 o->writeout_error = 1;
342 /*
343 * We return 0 nevertheless, as the index is all right
344 * and more importantly we have made best efforts to
345 * update paths in the work tree, and we cannot revert
346 * them.
347 */
348 case 0:
349 return 0;
350 default:
351 return 128;
352 }
353 }
354
355 struct branch_info {
356 const char *name; /* The short name used */
357 const char *path; /* The full name of a real branch */
358 struct commit *commit; /* The named commit */
359 };
360
361 static void setup_branch_path(struct branch_info *branch)
362 {
363 struct strbuf buf = STRBUF_INIT;
364 strbuf_addstr(&buf, "refs/heads/");
365 strbuf_addstr(&buf, branch->name);
366 branch->path = strbuf_detach(&buf, NULL);
367 }
368
369 static int merge_working_tree(struct checkout_opts *opts,
370 struct branch_info *old, struct branch_info *new)
371 {
372 int ret;
373 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
374 int newfd = hold_locked_index(lock_file, 1);
375
376 if (read_cache() < 0)
377 return error("corrupt index file");
378
379 if (opts->force) {
380 ret = reset_tree(new->commit->tree, opts, 1);
381 if (ret)
382 return ret;
383 } else {
384 struct tree_desc trees[2];
385 struct tree *tree;
386 struct unpack_trees_options topts;
387
388 memset(&topts, 0, sizeof(topts));
389 topts.head_idx = -1;
390 topts.src_index = &the_index;
391 topts.dst_index = &the_index;
392
393 topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
394
395 refresh_cache(REFRESH_QUIET);
396
397 if (unmerged_cache()) {
398 error("you need to resolve your current index first");
399 return 1;
400 }
401
402 /* 2-way merge to the new branch */
403 topts.initial_checkout = is_cache_unborn();
404 topts.update = 1;
405 topts.merge = 1;
406 topts.gently = opts->merge;
407 topts.verbose_update = !opts->quiet;
408 topts.fn = twoway_merge;
409 topts.dir = xcalloc(1, sizeof(*topts.dir));
410 topts.dir->show_ignored = 1;
411 topts.dir->exclude_per_dir = ".gitignore";
412 tree = parse_tree_indirect(old->commit->object.sha1);
413 init_tree_desc(&trees[0], tree->buffer, tree->size);
414 tree = parse_tree_indirect(new->commit->object.sha1);
415 init_tree_desc(&trees[1], tree->buffer, tree->size);
416
417 ret = unpack_trees(2, trees, &topts);
418 if (ret == -1) {
419 /*
420 * Unpack couldn't do a trivial merge; either
421 * give up or do a real merge, depending on
422 * whether the merge flag was used.
423 */
424 struct tree *result;
425 struct tree *work;
426 struct merge_options o;
427 if (!opts->merge)
428 return 1;
429 parse_commit(old->commit);
430
431 /* Do more real merge */
432
433 /*
434 * We update the index fully, then write the
435 * tree from the index, then merge the new
436 * branch with the current tree, with the old
437 * branch as the base. Then we reset the index
438 * (but not the working tree) to the new
439 * branch, leaving the working tree as the
440 * merged version, but skipping unmerged
441 * entries in the index.
442 */
443
444 add_files_to_cache(NULL, NULL, 0);
445 init_merge_options(&o);
446 o.verbosity = 0;
447 work = write_tree_from_memory(&o);
448
449 ret = reset_tree(new->commit->tree, opts, 1);
450 if (ret)
451 return ret;
452 o.branch1 = new->name;
453 o.branch2 = "local";
454 merge_trees(&o, new->commit->tree, work,
455 old->commit->tree, &result);
456 ret = reset_tree(new->commit->tree, opts, 0);
457 if (ret)
458 return ret;
459 }
460 }
461
462 if (write_cache(newfd, active_cache, active_nr) ||
463 commit_locked_index(lock_file))
464 die("unable to write new index file");
465
466 if (!opts->force && !opts->quiet)
467 show_local_changes(&new->commit->object);
468
469 return 0;
470 }
471
472 static void report_tracking(struct branch_info *new)
473 {
474 struct strbuf sb = STRBUF_INIT;
475 struct branch *branch = branch_get(new->name);
476
477 if (!format_tracking_info(branch, &sb))
478 return;
479 fputs(sb.buf, stdout);
480 strbuf_release(&sb);
481 }
482
483 static void update_refs_for_switch(struct checkout_opts *opts,
484 struct branch_info *old,
485 struct branch_info *new)
486 {
487 struct strbuf msg = STRBUF_INIT;
488 const char *old_desc;
489 if (opts->new_branch) {
490 create_branch(old->name, opts->new_branch, new->name, 0,
491 opts->new_branch_log, opts->track);
492 new->name = opts->new_branch;
493 setup_branch_path(new);
494 }
495
496 old_desc = old->name;
497 if (!old_desc && old->commit)
498 old_desc = sha1_to_hex(old->commit->object.sha1);
499 strbuf_addf(&msg, "checkout: moving from %s to %s",
500 old_desc ? old_desc : "(invalid)", new->name);
501
502 if (new->path) {
503 create_symref("HEAD", new->path, msg.buf);
504 if (!opts->quiet) {
505 if (old->path && !strcmp(new->path, old->path))
506 fprintf(stderr, "Already on \"%s\"\n",
507 new->name);
508 else
509 fprintf(stderr, "Switched to%s branch \"%s\"\n",
510 opts->new_branch ? " a new" : "",
511 new->name);
512 }
513 } else if (strcmp(new->name, "HEAD")) {
514 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
515 REF_NODEREF, DIE_ON_ERR);
516 if (!opts->quiet) {
517 if (old->path)
518 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);
519 describe_detached_head("HEAD is now at", new->commit);
520 }
521 }
522 remove_branch_state();
523 strbuf_release(&msg);
524 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
525 report_tracking(new);
526 }
527
528 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
529 {
530 int ret = 0;
531 struct branch_info old;
532 unsigned char rev[20];
533 int flag;
534 memset(&old, 0, sizeof(old));
535 old.path = resolve_ref("HEAD", rev, 0, &flag);
536 old.commit = lookup_commit_reference_gently(rev, 1);
537 if (!(flag & REF_ISSYMREF))
538 old.path = NULL;
539
540 if (old.path && !prefixcmp(old.path, "refs/heads/"))
541 old.name = old.path + strlen("refs/heads/");
542
543 if (!new->name) {
544 new->name = "HEAD";
545 new->commit = old.commit;
546 if (!new->commit)
547 die("You are on a branch yet to be born");
548 parse_commit(new->commit);
549 }
550
551 /*
552 * If we were on a detached HEAD, but we are now moving to
553 * a new commit, we want to mention the old commit once more
554 * to remind the user that it might be lost.
555 */
556 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
557 describe_detached_head("Previous HEAD position was", old.commit);
558
559 if (!old.commit && !opts->force) {
560 if (!opts->quiet) {
561 fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
562 fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
563 }
564 opts->force = 1;
565 }
566
567 ret = merge_working_tree(opts, &old, new);
568 if (ret)
569 return ret;
570
571 update_refs_for_switch(opts, &old, new);
572
573 ret = post_checkout_hook(old.commit, new->commit, 1);
574 return ret || opts->writeout_error;
575 }
576
577 static int git_checkout_config(const char *var, const char *value, void *cb)
578 {
579 return git_xmerge_config(var, value, cb);
580 }
581
582 int cmd_checkout(int argc, const char **argv, const char *prefix)
583 {
584 struct checkout_opts opts;
585 unsigned char rev[20];
586 const char *arg;
587 struct branch_info new;
588 struct tree *source_tree = NULL;
589 char *conflict_style = NULL;
590 struct option options[] = {
591 OPT__QUIET(&opts.quiet),
592 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
593 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
594 OPT_SET_INT('t', "track", &opts.track, "track",
595 BRANCH_TRACK_EXPLICIT),
596 OPT_SET_INT('2', "ours", &opts.writeout_stage, "stage",
597 2),
598 OPT_SET_INT('3', "theirs", &opts.writeout_stage, "stage",
599 3),
600 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
601 OPT_BOOLEAN('m', "merge", &opts.merge, "merge"),
602 OPT_STRING(0, "conflict", &conflict_style, "style",
603 "conflict style (merge or diff3)"),
604 OPT_END(),
605 };
606 int has_dash_dash;
607
608 memset(&opts, 0, sizeof(opts));
609 memset(&new, 0, sizeof(new));
610
611 git_config(git_checkout_config, NULL);
612
613 opts.track = BRANCH_TRACK_UNSPECIFIED;
614
615 argc = parse_options(argc, argv, options, checkout_usage,
616 PARSE_OPT_KEEP_DASHDASH);
617
618 /* --track without -b should DWIM */
619 if (0 < opts.track && !opts.new_branch) {
620 const char *argv0 = argv[0];
621 if (!argc || !strcmp(argv0, "--"))
622 die ("--track needs a branch name");
623 if (!prefixcmp(argv0, "refs/"))
624 argv0 += 5;
625 if (!prefixcmp(argv0, "remotes/"))
626 argv0 += 8;
627 argv0 = strchr(argv0, '/');
628 if (!argv0 || !argv0[1])
629 die ("Missing branch name; try -b");
630 opts.new_branch = argv0 + 1;
631 }
632
633 if (opts.track == BRANCH_TRACK_UNSPECIFIED)
634 opts.track = git_branch_track;
635 if (conflict_style) {
636 opts.merge = 1; /* implied */
637 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
638 }
639
640 if (opts.force && opts.merge)
641 die("git checkout: -f and -m are incompatible");
642
643 /*
644 * case 1: git checkout <ref> -- [<paths>]
645 *
646 * <ref> must be a valid tree, everything after the '--' must be
647 * a path.
648 *
649 * case 2: git checkout -- [<paths>]
650 *
651 * everything after the '--' must be paths.
652 *
653 * case 3: git checkout <something> [<paths>]
654 *
655 * With no paths, if <something> is a commit, that is to
656 * switch to the branch or detach HEAD at it.
657 *
658 * Otherwise <something> shall not be ambiguous.
659 * - If it's *only* a reference, treat it like case (1).
660 * - If it's only a path, treat it like case (2).
661 * - else: fail.
662 *
663 */
664 if (argc) {
665 if (!strcmp(argv[0], "--")) { /* case (2) */
666 argv++;
667 argc--;
668 goto no_reference;
669 }
670
671 arg = argv[0];
672 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
673
674 if (get_sha1(arg, rev)) {
675 if (has_dash_dash) /* case (1) */
676 die("invalid reference: %s", arg);
677 goto no_reference; /* case (3 -> 2) */
678 }
679
680 /* we can't end up being in (2) anymore, eat the argument */
681 argv++;
682 argc--;
683
684 new.name = arg;
685 if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
686 setup_branch_path(&new);
687 if (resolve_ref(new.path, rev, 1, NULL))
688 new.commit = lookup_commit_reference(rev);
689 else
690 new.path = NULL;
691 parse_commit(new.commit);
692 source_tree = new.commit->tree;
693 } else
694 source_tree = parse_tree_indirect(rev);
695
696 if (!source_tree) /* case (1): want a tree */
697 die("reference is not a tree: %s", arg);
698 if (!has_dash_dash) {/* case (3 -> 1) */
699 /*
700 * Do not complain the most common case
701 * git checkout branch
702 * even if there happen to be a file called 'branch';
703 * it would be extremely annoying.
704 */
705 if (argc)
706 verify_non_filename(NULL, arg);
707 }
708 else {
709 argv++;
710 argc--;
711 }
712 }
713
714 no_reference:
715 if (argc) {
716 const char **pathspec = get_pathspec(prefix, argv);
717
718 if (!pathspec)
719 die("invalid path specification");
720
721 /* Checkout paths */
722 if (opts.new_branch) {
723 if (argc == 1) {
724 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]);
725 } else {
726 die("git checkout: updating paths is incompatible with switching branches.");
727 }
728 }
729
730 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
731 die("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index.");
732
733 return checkout_paths(source_tree, pathspec, &opts);
734 }
735
736 if (opts.new_branch) {
737 struct strbuf buf = STRBUF_INIT;
738 strbuf_addstr(&buf, "refs/heads/");
739 strbuf_addstr(&buf, opts.new_branch);
740 if (!get_sha1(buf.buf, rev))
741 die("git checkout: branch %s already exists", opts.new_branch);
742 if (check_ref_format(buf.buf))
743 die("git checkout: we do not like '%s' as a branch name.", opts.new_branch);
744 strbuf_release(&buf);
745 }
746
747 if (new.name && !new.commit) {
748 die("Cannot switch branch to a non-commit.");
749 }
750 if (opts.writeout_stage)
751 die("--ours/--theirs is incompatible with switching branches.");
752
753 return switch_branches(&opts, &new);
754 }