checkout: make reset_clean_to_new() not die by itself
[git/git.git] / builtin-checkout.c
CommitLineData
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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"
79a1e6b4 15#include "remote.h"
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16
17static const char * const checkout_usage[] = {
18 "git checkout [options] <branch>",
19 "git checkout [options] [<branch>] -- <file>...",
20 NULL,
21};
22
23static int post_checkout_hook(struct commit *old, struct commit *new,
24 int changed)
25{
26 struct child_process proc;
27 const char *name = git_path("hooks/post-checkout");
28 const char *argv[5];
29
30 if (access(name, X_OK) < 0)
31 return 0;
32
33 memset(&proc, 0, sizeof(proc));
34 argv[0] = name;
35 argv[1] = xstrdup(sha1_to_hex(old->object.sha1));
36 argv[2] = xstrdup(sha1_to_hex(new->object.sha1));
37 argv[3] = changed ? "1" : "0";
38 argv[4] = NULL;
39 proc.argv = argv;
40 proc.no_stdin = 1;
41 proc.stdout_to_stderr = 1;
42 return run_command(&proc);
43}
44
45static int update_some(const unsigned char *sha1, const char *base, int baselen,
46 const char *pathname, unsigned mode, int stage)
47{
48 int len;
49 struct cache_entry *ce;
50
51 if (S_ISGITLINK(mode))
52 return 0;
53
54 if (S_ISDIR(mode))
55 return READ_TREE_RECURSIVE;
56
57 len = baselen + strlen(pathname);
58 ce = xcalloc(1, cache_entry_size(len));
59 hashcpy(ce->sha1, sha1);
60 memcpy(ce->name, base, baselen);
61 memcpy(ce->name + baselen, pathname, len - baselen);
62 ce->ce_flags = create_ce_flags(len, 0);
63 ce->ce_mode = create_ce_mode(mode);
64 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
65 return 0;
66}
67
68static int read_tree_some(struct tree *tree, const char **pathspec)
69{
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70 read_tree_recursive(tree, "", 0, 0, pathspec, update_some);
71
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72 /* update the index with the given tree's info
73 * for all args, expanding wildcards, and exit
74 * with any non-zero return code.
75 */
76 return 0;
77}
78
75336878 79static int checkout_paths(struct tree *source_tree, const char **pathspec)
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80{
81 int pos;
82 struct checkout state;
83 static char *ps_matched;
84 unsigned char rev[20];
85 int flag;
86 struct commit *head;
d2b3691b 87 int errs = 0;
782c2d65 88
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DB
89 int newfd;
90 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
91
92 newfd = hold_locked_index(lock_file, 1);
93 read_cache();
94
95 if (source_tree)
96 read_tree_some(source_tree, pathspec);
97
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98 for (pos = 0; pathspec[pos]; pos++)
99 ;
100 ps_matched = xcalloc(1, pos);
101
102 for (pos = 0; pos < active_nr; pos++) {
103 struct cache_entry *ce = active_cache[pos];
104 pathspec_match(pathspec, ps_matched, ce->name, 0);
105 }
106
107 if (report_path_error(ps_matched, pathspec, 0))
108 return 1;
109
d2b3691b 110 /* Now we are committed to check them out */
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111 memset(&state, 0, sizeof(state));
112 state.force = 1;
113 state.refresh_cache = 1;
114 for (pos = 0; pos < active_nr; pos++) {
115 struct cache_entry *ce = active_cache[pos];
116 if (pathspec_match(pathspec, NULL, ce->name, 0)) {
d2b3691b 117 errs |= checkout_entry(ce, &state, NULL);
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118 }
119 }
120
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121 if (write_cache(newfd, active_cache, active_nr) ||
122 commit_locked_index(lock_file))
123 die("unable to write new index file");
124
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125 resolve_ref("HEAD", rev, 0, &flag);
126 head = lookup_commit_reference_gently(rev, 1);
127
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JH
128 errs |= post_checkout_hook(head, head, 0);
129 return errs;
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130}
131
132static void show_local_changes(struct object *head)
133{
134 struct rev_info rev;
135 /* I think we want full paths, even if we're in a subdirectory. */
136 init_revisions(&rev, NULL);
137 rev.abbrev = 0;
138 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
139 add_pending_object(&rev, head, NULL);
140 run_diff_index(&rev, 0);
141}
142
143static void describe_detached_head(char *msg, struct commit *commit)
144{
145 struct strbuf sb;
146 strbuf_init(&sb, 0);
147 parse_commit(commit);
27886318 148 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
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149 fprintf(stderr, "%s %s... %s\n", msg,
150 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
151 strbuf_release(&sb);
152}
153
154static int reset_to_new(struct tree *tree, int quiet)
155{
156 struct unpack_trees_options opts;
157 struct tree_desc tree_desc;
bc052d7f 158
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159 memset(&opts, 0, sizeof(opts));
160 opts.head_idx = -1;
161 opts.update = 1;
162 opts.reset = 1;
163 opts.merge = 1;
164 opts.fn = oneway_merge;
165 opts.verbose_update = !quiet;
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LT
166 opts.src_index = &the_index;
167 opts.dst_index = &the_index;
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168 parse_tree(tree);
169 init_tree_desc(&tree_desc, tree->buffer, tree->size);
170 if (unpack_trees(1, &tree_desc, &opts))
171 return 128;
172 return 0;
173}
174
84a5750b 175static int reset_clean_to_new(struct tree *tree, int quiet)
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176{
177 struct unpack_trees_options opts;
178 struct tree_desc tree_desc;
bc052d7f 179
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180 memset(&opts, 0, sizeof(opts));
181 opts.head_idx = -1;
182 opts.skip_unmerged = 1;
183 opts.reset = 1;
184 opts.merge = 1;
185 opts.fn = oneway_merge;
186 opts.verbose_update = !quiet;
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LT
187 opts.src_index = &the_index;
188 opts.dst_index = &the_index;
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189 parse_tree(tree);
190 init_tree_desc(&tree_desc, tree->buffer, tree->size);
191 if (unpack_trees(1, &tree_desc, &opts))
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192 return 128;
193 return 0;
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194}
195
196struct checkout_opts {
197 int quiet;
198 int merge;
199 int force;
200
201 char *new_branch;
202 int new_branch_log;
9ed36cfa 203 enum branch_track track;
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204};
205
206struct branch_info {
207 const char *name; /* The short name used */
208 const char *path; /* The full name of a real branch */
209 struct commit *commit; /* The named commit */
210};
211
212static void setup_branch_path(struct branch_info *branch)
213{
214 struct strbuf buf;
215 strbuf_init(&buf, 0);
216 strbuf_addstr(&buf, "refs/heads/");
217 strbuf_addstr(&buf, branch->name);
218 branch->path = strbuf_detach(&buf, NULL);
219}
220
221static int merge_working_tree(struct checkout_opts *opts,
75ea38df 222 struct branch_info *old, struct branch_info *new)
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223{
224 int ret;
225 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
226 int newfd = hold_locked_index(lock_file, 1);
227 read_cache();
228
229 if (opts->force) {
230 ret = reset_to_new(new->commit->tree, opts->quiet);
231 if (ret)
232 return ret;
233 } else {
234 struct tree_desc trees[2];
235 struct tree *tree;
236 struct unpack_trees_options topts;
bc052d7f 237
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238 memset(&topts, 0, sizeof(topts));
239 topts.head_idx = -1;
34110cd4
LT
240 topts.src_index = &the_index;
241 topts.dst_index = &the_index;
782c2d65 242
8ccba008
JH
243 topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
244
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245 refresh_cache(REFRESH_QUIET);
246
247 if (unmerged_cache()) {
04c9e11f
JH
248 error("you need to resolve your current index first");
249 return 1;
782c2d65 250 }
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251
252 /* 2-way merge to the new branch */
253 topts.update = 1;
254 topts.merge = 1;
255 topts.gently = opts->merge;
256 topts.verbose_update = !opts->quiet;
257 topts.fn = twoway_merge;
258 topts.dir = xcalloc(1, sizeof(*topts.dir));
259 topts.dir->show_ignored = 1;
260 topts.dir->exclude_per_dir = ".gitignore";
261 tree = parse_tree_indirect(old->commit->object.sha1);
262 init_tree_desc(&trees[0], tree->buffer, tree->size);
263 tree = parse_tree_indirect(new->commit->object.sha1);
264 init_tree_desc(&trees[1], tree->buffer, tree->size);
265
266 if (unpack_trees(2, trees, &topts)) {
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267 /*
268 * Unpack couldn't do a trivial merge; either
269 * give up or do a real merge, depending on
270 * whether the merge flag was used.
271 */
272 struct tree *result;
273 struct tree *work;
274 if (!opts->merge)
275 return 1;
276 parse_commit(old->commit);
277
278 /* Do more real merge */
279
280 /*
281 * We update the index fully, then write the
282 * tree from the index, then merge the new
283 * branch with the current tree, with the old
284 * branch as the base. Then we reset the index
285 * (but not the working tree) to the new
286 * branch, leaving the working tree as the
287 * merged version, but skipping unmerged
288 * entries in the index.
289 */
290
7ae02a30 291 add_files_to_cache(NULL, NULL, 0);
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292 work = write_tree_from_memory();
293
294 ret = reset_to_new(new->commit->tree, opts->quiet);
295 if (ret)
296 return ret;
297 merge_trees(new->commit->tree, work, old->commit->tree,
298 new->name, "local", &result);
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299 ret = reset_clean_to_new(new->commit->tree, opts->quiet);
300 if (ret)
301 return ret;
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302 }
303 }
304
305 if (write_cache(newfd, active_cache, active_nr) ||
306 commit_locked_index(lock_file))
307 die("unable to write new index file");
308
309 if (!opts->force)
310 show_local_changes(&new->commit->object);
311
312 return 0;
313}
314
b56fca07 315static void report_tracking(struct branch_info *new, struct checkout_opts *opts)
79a1e6b4
JH
316{
317 /*
318 * We have switched to a new branch; is it building on
319 * top of another branch, and if so does that other branch
320 * have changes we do not have yet?
321 */
322 char *base;
323 unsigned char sha1[20];
324 struct commit *ours, *theirs;
79a1e6b4 325 char symmetric[84];
b0030db3
JH
326 struct rev_info revs;
327 const char *rev_argv[10];
328 int rev_argc;
329 int num_ours, num_theirs;
330 const char *remote_msg;
b56fca07 331 struct branch *branch = branch_get(new->name);
79a1e6b4 332
b0030db3
JH
333 /*
334 * Nothing to report unless we are marked to build on top of
335 * somebody else.
336 */
b56fca07 337 if (!branch || !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
79a1e6b4 338 return;
79a1e6b4 339
79a1e6b4 340 /*
b0030db3
JH
341 * If what we used to build on no longer exists, there is
342 * nothing to report.
79a1e6b4 343 */
b0030db3 344 base = branch->merge[0]->dst;
79a1e6b4
JH
345 if (!resolve_ref(base, sha1, 1, NULL))
346 return;
79a1e6b4 347
b0030db3
JH
348 theirs = lookup_commit(sha1);
349 ours = new->commit;
79a1e6b4
JH
350 if (!hashcmp(sha1, ours->object.sha1))
351 return; /* we are the same */
352
b0030db3
JH
353 /* Run "rev-list --left-right ours...theirs" internally... */
354 rev_argc = 0;
355 rev_argv[rev_argc++] = NULL;
356 rev_argv[rev_argc++] = "--left-right";
357 rev_argv[rev_argc++] = symmetric;
358 rev_argv[rev_argc++] = "--";
359 rev_argv[rev_argc] = NULL;
360
361 strcpy(symmetric, sha1_to_hex(ours->object.sha1));
362 strcpy(symmetric + 40, "...");
363 strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
364
365 init_revisions(&revs, NULL);
366 setup_revisions(rev_argc, rev_argv, &revs, NULL);
367 prepare_revision_walk(&revs);
368
369 /* ... and count the commits on each side. */
370 num_ours = 0;
371 num_theirs = 0;
372 while (1) {
373 struct commit *c = get_revision(&revs);
374 if (!c)
375 break;
376 if (c->object.flags & SYMMETRIC_LEFT)
377 num_ours++;
378 else
379 num_theirs++;
79a1e6b4 380 }
79a1e6b4 381
b0030db3
JH
382 if (!prefixcmp(base, "refs/remotes/")) {
383 remote_msg = " remote";
79a1e6b4 384 base += strlen("refs/remotes/");
b0030db3
JH
385 } else {
386 remote_msg = "";
79a1e6b4 387 }
79a1e6b4 388
b0030db3
JH
389 if (!num_theirs)
390 printf("Your branch is ahead of the tracked%s branch '%s' "
391 "by %d commit%s.\n",
392 remote_msg, base,
393 num_ours, (num_ours == 1) ? "" : "s");
394 else if (!num_ours)
b56fca07 395 printf("Your branch is behind the tracked%s branch '%s' "
b0030db3
JH
396 "by %d commit%s,\n"
397 "and can be fast-forwarded.\n",
398 remote_msg, base,
399 num_theirs, (num_theirs == 1) ? "" : "s");
400 else
401 printf("Your branch and the tracked%s branch '%s' "
402 "have diverged,\nand respectively "
403 "have %d and %d different commit(s) each.\n",
404 remote_msg, base,
405 num_ours, num_theirs);
406}
79a1e6b4 407
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DB
408static void update_refs_for_switch(struct checkout_opts *opts,
409 struct branch_info *old,
410 struct branch_info *new)
411{
412 struct strbuf msg;
413 const char *old_desc;
414 if (opts->new_branch) {
415 create_branch(old->name, opts->new_branch, new->name, 0,
416 opts->new_branch_log, opts->track);
417 new->name = opts->new_branch;
418 setup_branch_path(new);
419 }
420
421 strbuf_init(&msg, 0);
422 old_desc = old->name;
423 if (!old_desc)
424 old_desc = sha1_to_hex(old->commit->object.sha1);
425 strbuf_addf(&msg, "checkout: moving from %s to %s",
426 old_desc, new->name);
427
428 if (new->path) {
429 create_symref("HEAD", new->path, msg.buf);
430 if (!opts->quiet) {
431 if (old->path && !strcmp(new->path, old->path))
432 fprintf(stderr, "Already on \"%s\"\n",
433 new->name);
434 else
435 fprintf(stderr, "Switched to%s branch \"%s\"\n",
436 opts->new_branch ? " a new" : "",
437 new->name);
438 }
439 } else if (strcmp(new->name, "HEAD")) {
440 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
441 REF_NODEREF, DIE_ON_ERR);
442 if (!opts->quiet) {
443 if (old->path)
444 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);
445 describe_detached_head("HEAD is now at", new->commit);
446 }
447 }
448 remove_branch_state();
449 strbuf_release(&msg);
b0030db3 450 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
b56fca07 451 report_tracking(new, opts);
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DB
452}
453
75ea38df 454static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
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DB
455{
456 int ret = 0;
457 struct branch_info old;
458 unsigned char rev[20];
459 int flag;
460 memset(&old, 0, sizeof(old));
461 old.path = resolve_ref("HEAD", rev, 0, &flag);
462 old.commit = lookup_commit_reference_gently(rev, 1);
463 if (!(flag & REF_ISSYMREF))
464 old.path = NULL;
465
466 if (old.path && !prefixcmp(old.path, "refs/heads/"))
467 old.name = old.path + strlen("refs/heads/");
468
469 if (!new->name) {
470 new->name = "HEAD";
471 new->commit = old.commit;
472 if (!new->commit)
473 die("You are on a branch yet to be born");
474 parse_commit(new->commit);
475 }
476
477 /*
478 * If the new thing isn't a branch and isn't HEAD and we're
479 * not starting a new branch, and we want messages, and we
480 * weren't on a branch, and we're moving to a new commit,
481 * describe the old commit.
482 */
483 if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
484 !opts->quiet && !old.path && new->commit != old.commit)
485 describe_detached_head("Previous HEAD position was", old.commit);
486
487 if (!old.commit) {
488 if (!opts->quiet) {
489 fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
490 fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
491 }
492 opts->force = 1;
493 }
494
75ea38df 495 ret = merge_working_tree(opts, &old, new);
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DB
496 if (ret)
497 return ret;
498
499 update_refs_for_switch(opts, &old, new);
500
501 return post_checkout_hook(old.commit, new->commit, 1);
502}
503
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504int cmd_checkout(int argc, const char **argv, const char *prefix)
505{
506 struct checkout_opts opts;
507 unsigned char rev[20];
508 const char *arg;
509 struct branch_info new;
510 struct tree *source_tree = NULL;
511 struct option options[] = {
512 OPT__QUIET(&opts.quiet),
513 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
514 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
498a6e7e 515 OPT_SET_INT('t', "track", &opts.track, "track",
9ed36cfa 516 BRANCH_TRACK_EXPLICIT),
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517 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
518 OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
b249b552 519 OPT_END(),
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DB
520 };
521
522 memset(&opts, 0, sizeof(opts));
523 memset(&new, 0, sizeof(new));
524
ef90d6d4 525 git_config(git_default_config, NULL);
782c2d65 526
9ed36cfa 527 opts.track = git_branch_track;
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DB
528
529 argc = parse_options(argc, argv, options, checkout_usage, 0);
530 if (argc) {
531 arg = argv[0];
532 if (get_sha1(arg, rev))
533 ;
534 else if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
535 new.name = arg;
536 setup_branch_path(&new);
537 if (resolve_ref(new.path, rev, 1, NULL))
538 new.commit = lookup_commit_reference(rev);
539 else
540 new.path = NULL;
541 parse_commit(new.commit);
542 source_tree = new.commit->tree;
543 argv++;
544 argc--;
545 } else if ((source_tree = parse_tree_indirect(rev))) {
546 argv++;
547 argc--;
548 }
549 }
550
551 if (argc && !strcmp(argv[0], "--")) {
552 argv++;
553 argc--;
554 }
555
9ed36cfa 556 if (!opts.new_branch && (opts.track != git_branch_track))
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DB
557 die("git checkout: --track and --no-track require -b");
558
559 if (opts.force && opts.merge)
560 die("git checkout: -f and -m are incompatible");
561
562 if (argc) {
563 const char **pathspec = get_pathspec(prefix, argv);
301e42ed
AR
564
565 if (!pathspec)
566 die("invalid path specification");
567
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DB
568 /* Checkout paths */
569 if (opts.new_branch || opts.force || opts.merge) {
570 if (argc == 1) {
571 die("git checkout: updating paths is incompatible with switching branches/forcing\nDid you intend to checkout '%s' which can not be resolved as commit?", argv[0]);
572 } else {
573 die("git checkout: updating paths is incompatible with switching branches/forcing");
574 }
575 }
576
75336878 577 return checkout_paths(source_tree, pathspec);
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DB
578 }
579
580 if (new.name && !new.commit) {
581 die("Cannot switch branch to a non-commit.");
582 }
583
75ea38df 584 return switch_branches(&opts, &new);
782c2d65 585}