unpack_trees(): allow callers to differentiate worktree errors from merge errors
[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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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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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
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154struct checkout_opts {
155 int quiet;
156 int merge;
157 int force;
bc052d7f 158
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159 char *new_branch;
160 int new_branch_log;
161 enum branch_track track;
162};
782c2d65 163
6286a08d 164static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
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165{
166 struct unpack_trees_options opts;
167 struct tree_desc tree_desc;
bc052d7f 168
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169 memset(&opts, 0, sizeof(opts));
170 opts.head_idx = -1;
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171 opts.update = worktree;
172 opts.skip_unmerged = !worktree;
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173 opts.reset = 1;
174 opts.merge = 1;
175 opts.fn = oneway_merge;
6286a08d 176 opts.verbose_update = !o->quiet;
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177 opts.src_index = &the_index;
178 opts.dst_index = &the_index;
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179 parse_tree(tree);
180 init_tree_desc(&tree_desc, tree->buffer, tree->size);
181 if (unpack_trees(1, &tree_desc, &opts))
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182 return 128;
183 return 0;
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184}
185
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186struct branch_info {
187 const char *name; /* The short name used */
188 const char *path; /* The full name of a real branch */
189 struct commit *commit; /* The named commit */
190};
191
192static void setup_branch_path(struct branch_info *branch)
193{
194 struct strbuf buf;
195 strbuf_init(&buf, 0);
196 strbuf_addstr(&buf, "refs/heads/");
197 strbuf_addstr(&buf, branch->name);
198 branch->path = strbuf_detach(&buf, NULL);
199}
200
201static int merge_working_tree(struct checkout_opts *opts,
75ea38df 202 struct branch_info *old, struct branch_info *new)
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203{
204 int ret;
205 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
206 int newfd = hold_locked_index(lock_file, 1);
207 read_cache();
208
209 if (opts->force) {
6286a08d 210 ret = reset_tree(new->commit->tree, opts, 1);
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211 if (ret)
212 return ret;
213 } else {
214 struct tree_desc trees[2];
215 struct tree *tree;
216 struct unpack_trees_options topts;
bc052d7f 217
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218 memset(&topts, 0, sizeof(topts));
219 topts.head_idx = -1;
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LT
220 topts.src_index = &the_index;
221 topts.dst_index = &the_index;
782c2d65 222
8ccba008
JH
223 topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
224
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225 refresh_cache(REFRESH_QUIET);
226
227 if (unmerged_cache()) {
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228 error("you need to resolve your current index first");
229 return 1;
782c2d65 230 }
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231
232 /* 2-way merge to the new branch */
233 topts.update = 1;
234 topts.merge = 1;
235 topts.gently = opts->merge;
236 topts.verbose_update = !opts->quiet;
237 topts.fn = twoway_merge;
238 topts.dir = xcalloc(1, sizeof(*topts.dir));
239 topts.dir->show_ignored = 1;
240 topts.dir->exclude_per_dir = ".gitignore";
241 tree = parse_tree_indirect(old->commit->object.sha1);
242 init_tree_desc(&trees[0], tree->buffer, tree->size);
243 tree = parse_tree_indirect(new->commit->object.sha1);
244 init_tree_desc(&trees[1], tree->buffer, tree->size);
245
246 if (unpack_trees(2, trees, &topts)) {
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247 /*
248 * Unpack couldn't do a trivial merge; either
249 * give up or do a real merge, depending on
250 * whether the merge flag was used.
251 */
252 struct tree *result;
253 struct tree *work;
254 if (!opts->merge)
255 return 1;
256 parse_commit(old->commit);
257
258 /* Do more real merge */
259
260 /*
261 * We update the index fully, then write the
262 * tree from the index, then merge the new
263 * branch with the current tree, with the old
264 * branch as the base. Then we reset the index
265 * (but not the working tree) to the new
266 * branch, leaving the working tree as the
267 * merged version, but skipping unmerged
268 * entries in the index.
269 */
270
7ae02a30 271 add_files_to_cache(NULL, NULL, 0);
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272 work = write_tree_from_memory();
273
6286a08d 274 ret = reset_tree(new->commit->tree, opts, 1);
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275 if (ret)
276 return ret;
277 merge_trees(new->commit->tree, work, old->commit->tree,
278 new->name, "local", &result);
6286a08d 279 ret = reset_tree(new->commit->tree, opts, 0);
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280 if (ret)
281 return ret;
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282 }
283 }
284
285 if (write_cache(newfd, active_cache, active_nr) ||
286 commit_locked_index(lock_file))
287 die("unable to write new index file");
288
289 if (!opts->force)
290 show_local_changes(&new->commit->object);
291
292 return 0;
293}
294
b56fca07 295static void report_tracking(struct branch_info *new, struct checkout_opts *opts)
79a1e6b4
JH
296{
297 /*
298 * We have switched to a new branch; is it building on
299 * top of another branch, and if so does that other branch
300 * have changes we do not have yet?
301 */
302 char *base;
303 unsigned char sha1[20];
304 struct commit *ours, *theirs;
79a1e6b4 305 char symmetric[84];
b0030db3
JH
306 struct rev_info revs;
307 const char *rev_argv[10];
308 int rev_argc;
309 int num_ours, num_theirs;
310 const char *remote_msg;
b56fca07 311 struct branch *branch = branch_get(new->name);
79a1e6b4 312
b0030db3
JH
313 /*
314 * Nothing to report unless we are marked to build on top of
315 * somebody else.
316 */
b56fca07 317 if (!branch || !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
79a1e6b4 318 return;
79a1e6b4 319
79a1e6b4 320 /*
b0030db3
JH
321 * If what we used to build on no longer exists, there is
322 * nothing to report.
79a1e6b4 323 */
b0030db3 324 base = branch->merge[0]->dst;
79a1e6b4
JH
325 if (!resolve_ref(base, sha1, 1, NULL))
326 return;
79a1e6b4 327
b0030db3
JH
328 theirs = lookup_commit(sha1);
329 ours = new->commit;
79a1e6b4
JH
330 if (!hashcmp(sha1, ours->object.sha1))
331 return; /* we are the same */
332
b0030db3
JH
333 /* Run "rev-list --left-right ours...theirs" internally... */
334 rev_argc = 0;
335 rev_argv[rev_argc++] = NULL;
336 rev_argv[rev_argc++] = "--left-right";
337 rev_argv[rev_argc++] = symmetric;
338 rev_argv[rev_argc++] = "--";
339 rev_argv[rev_argc] = NULL;
340
341 strcpy(symmetric, sha1_to_hex(ours->object.sha1));
342 strcpy(symmetric + 40, "...");
343 strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1));
344
345 init_revisions(&revs, NULL);
346 setup_revisions(rev_argc, rev_argv, &revs, NULL);
347 prepare_revision_walk(&revs);
348
349 /* ... and count the commits on each side. */
350 num_ours = 0;
351 num_theirs = 0;
352 while (1) {
353 struct commit *c = get_revision(&revs);
354 if (!c)
355 break;
356 if (c->object.flags & SYMMETRIC_LEFT)
357 num_ours++;
358 else
359 num_theirs++;
79a1e6b4 360 }
79a1e6b4 361
b0030db3
JH
362 if (!prefixcmp(base, "refs/remotes/")) {
363 remote_msg = " remote";
79a1e6b4 364 base += strlen("refs/remotes/");
b0030db3
JH
365 } else {
366 remote_msg = "";
79a1e6b4 367 }
79a1e6b4 368
b0030db3
JH
369 if (!num_theirs)
370 printf("Your branch is ahead of the tracked%s branch '%s' "
371 "by %d commit%s.\n",
372 remote_msg, base,
373 num_ours, (num_ours == 1) ? "" : "s");
374 else if (!num_ours)
b56fca07 375 printf("Your branch is behind the tracked%s branch '%s' "
b0030db3
JH
376 "by %d commit%s,\n"
377 "and can be fast-forwarded.\n",
378 remote_msg, base,
379 num_theirs, (num_theirs == 1) ? "" : "s");
380 else
381 printf("Your branch and the tracked%s branch '%s' "
382 "have diverged,\nand respectively "
383 "have %d and %d different commit(s) each.\n",
384 remote_msg, base,
385 num_ours, num_theirs);
386}
79a1e6b4 387
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388static void update_refs_for_switch(struct checkout_opts *opts,
389 struct branch_info *old,
390 struct branch_info *new)
391{
392 struct strbuf msg;
393 const char *old_desc;
394 if (opts->new_branch) {
395 create_branch(old->name, opts->new_branch, new->name, 0,
396 opts->new_branch_log, opts->track);
397 new->name = opts->new_branch;
398 setup_branch_path(new);
399 }
400
401 strbuf_init(&msg, 0);
402 old_desc = old->name;
403 if (!old_desc)
404 old_desc = sha1_to_hex(old->commit->object.sha1);
405 strbuf_addf(&msg, "checkout: moving from %s to %s",
406 old_desc, new->name);
407
408 if (new->path) {
409 create_symref("HEAD", new->path, msg.buf);
410 if (!opts->quiet) {
411 if (old->path && !strcmp(new->path, old->path))
412 fprintf(stderr, "Already on \"%s\"\n",
413 new->name);
414 else
415 fprintf(stderr, "Switched to%s branch \"%s\"\n",
416 opts->new_branch ? " a new" : "",
417 new->name);
418 }
419 } else if (strcmp(new->name, "HEAD")) {
420 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
421 REF_NODEREF, DIE_ON_ERR);
422 if (!opts->quiet) {
423 if (old->path)
424 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);
425 describe_detached_head("HEAD is now at", new->commit);
426 }
427 }
428 remove_branch_state();
429 strbuf_release(&msg);
b0030db3 430 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
b56fca07 431 report_tracking(new, opts);
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DB
432}
433
75ea38df 434static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
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DB
435{
436 int ret = 0;
437 struct branch_info old;
438 unsigned char rev[20];
439 int flag;
440 memset(&old, 0, sizeof(old));
441 old.path = resolve_ref("HEAD", rev, 0, &flag);
442 old.commit = lookup_commit_reference_gently(rev, 1);
443 if (!(flag & REF_ISSYMREF))
444 old.path = NULL;
445
446 if (old.path && !prefixcmp(old.path, "refs/heads/"))
447 old.name = old.path + strlen("refs/heads/");
448
449 if (!new->name) {
450 new->name = "HEAD";
451 new->commit = old.commit;
452 if (!new->commit)
453 die("You are on a branch yet to be born");
454 parse_commit(new->commit);
455 }
456
457 /*
458 * If the new thing isn't a branch and isn't HEAD and we're
459 * not starting a new branch, and we want messages, and we
460 * weren't on a branch, and we're moving to a new commit,
461 * describe the old commit.
462 */
463 if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
464 !opts->quiet && !old.path && new->commit != old.commit)
465 describe_detached_head("Previous HEAD position was", old.commit);
466
467 if (!old.commit) {
468 if (!opts->quiet) {
469 fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
470 fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
471 }
472 opts->force = 1;
473 }
474
75ea38df 475 ret = merge_working_tree(opts, &old, new);
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DB
476 if (ret)
477 return ret;
478
479 update_refs_for_switch(opts, &old, new);
480
481 return post_checkout_hook(old.commit, new->commit, 1);
482}
483
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484int cmd_checkout(int argc, const char **argv, const char *prefix)
485{
486 struct checkout_opts opts;
487 unsigned char rev[20];
488 const char *arg;
489 struct branch_info new;
490 struct tree *source_tree = NULL;
491 struct option options[] = {
492 OPT__QUIET(&opts.quiet),
493 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
494 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
498a6e7e 495 OPT_SET_INT('t', "track", &opts.track, "track",
9ed36cfa 496 BRANCH_TRACK_EXPLICIT),
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DB
497 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
498 OPT_BOOLEAN('m', NULL, &opts.merge, "merge"),
b249b552 499 OPT_END(),
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DB
500 };
501
502 memset(&opts, 0, sizeof(opts));
503 memset(&new, 0, sizeof(new));
504
ef90d6d4 505 git_config(git_default_config, NULL);
782c2d65 506
9ed36cfa 507 opts.track = git_branch_track;
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DB
508
509 argc = parse_options(argc, argv, options, checkout_usage, 0);
510 if (argc) {
511 arg = argv[0];
512 if (get_sha1(arg, rev))
513 ;
514 else if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
515 new.name = arg;
516 setup_branch_path(&new);
517 if (resolve_ref(new.path, rev, 1, NULL))
518 new.commit = lookup_commit_reference(rev);
519 else
520 new.path = NULL;
521 parse_commit(new.commit);
522 source_tree = new.commit->tree;
523 argv++;
524 argc--;
525 } else if ((source_tree = parse_tree_indirect(rev))) {
526 argv++;
527 argc--;
528 }
529 }
530
531 if (argc && !strcmp(argv[0], "--")) {
532 argv++;
533 argc--;
534 }
535
9ed36cfa 536 if (!opts.new_branch && (opts.track != git_branch_track))
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DB
537 die("git checkout: --track and --no-track require -b");
538
539 if (opts.force && opts.merge)
540 die("git checkout: -f and -m are incompatible");
541
542 if (argc) {
543 const char **pathspec = get_pathspec(prefix, argv);
301e42ed
AR
544
545 if (!pathspec)
546 die("invalid path specification");
547
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DB
548 /* Checkout paths */
549 if (opts.new_branch || opts.force || opts.merge) {
550 if (argc == 1) {
551 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]);
552 } else {
553 die("git checkout: updating paths is incompatible with switching branches/forcing");
554 }
555 }
556
75336878 557 return checkout_paths(source_tree, pathspec);
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DB
558 }
559
560 if (new.name && !new.commit) {
561 die("Cannot switch branch to a non-commit.");
562 }
563
75ea38df 564 return switch_branches(&opts, &new);
782c2d65 565}