checkout.txt: note about losing staged changes with --merge
[git/git.git] / builtin / checkout.c
CommitLineData
f8adbec9 1#define USE_THE_INDEX_COMPATIBILITY_MACROS
782c2d65 2#include "builtin.h"
b2141fc1 3#include "config.h"
7c85a87c 4#include "checkout.h"
697cc8ef 5#include "lockfile.h"
782c2d65
DB
6#include "parse-options.h"
7#include "refs.h"
cbd53a21 8#include "object-store.h"
782c2d65
DB
9#include "commit.h"
10#include "tree.h"
11#include "tree-walk.h"
b9d37a54 12#include "cache-tree.h"
782c2d65
DB
13#include "unpack-trees.h"
14#include "dir.h"
15#include "run-command.h"
16#include "merge-recursive.h"
17#include "branch.h"
18#include "diff.h"
19#include "revision.h"
79a1e6b4 20#include "remote.h"
0cf8581e
JH
21#include "blob.h"
22#include "xdiff-interface.h"
23#include "ll-merge.h"
cfc5789a 24#include "resolve-undo.h"
851e18c3 25#include "submodule-config.h"
175f6e59 26#include "submodule.h"
ad8d5104 27#include "advice.h"
782c2d65 28
fa655d84
BP
29static int checkout_optimize_new_branch;
30
782c2d65 31static const char * const checkout_usage[] = {
9c9b4f2f
AH
32 N_("git checkout [<options>] <branch>"),
33 N_("git checkout [<options>] [<branch>] -- <file>..."),
782c2d65
DB
34 NULL,
35};
36
db941099 37struct checkout_opts {
e51e3057 38 int patch_mode;
db941099
JH
39 int quiet;
40 int merge;
41 int force;
32669671 42 int force_detach;
38901a48 43 int writeout_stage;
c1d7036b 44 int overwrite_ignore;
08d595dc 45 int ignore_skipworktree;
1d0fa898 46 int ignore_other_worktrees;
870ebdb9 47 int show_progress;
0f086e6d 48 int count_checkout_paths;
fa655d84
BP
49 /*
50 * If new checkout options are added, skip_merge_working_tree
51 * should be updated accordingly.
52 */
db941099
JH
53
54 const char *new_branch;
02ac9837 55 const char *new_branch_force;
9db5ebf4 56 const char *new_orphan_branch;
db941099
JH
57 int new_branch_log;
58 enum branch_track track;
175f6e59 59 struct diff_options diff_options;
e51e3057
NTND
60
61 int branch_exists;
62 const char *prefix;
817b345a 63 struct pathspec pathspec;
e51e3057 64 struct tree *source_tree;
db941099
JH
65};
66
c8a3ea1f 67static int post_checkout_hook(struct commit *old_commit, struct commit *new_commit,
782c2d65
DB
68 int changed)
69{
15048f8a 70 return run_hook_le(NULL, "post-checkout",
c8a3ea1f
BW
71 oid_to_hex(old_commit ? &old_commit->object.oid : &null_oid),
72 oid_to_hex(new_commit ? &new_commit->object.oid : &null_oid),
15048f8a 73 changed ? "1" : "0", NULL);
c8a3ea1f 74 /* "new_commit" can be NULL when checking out from the index before
2292ce47 75 a commit exists. */
ae98a008 76
782c2d65
DB
77}
78
df46d77e 79static int update_some(const struct object_id *oid, struct strbuf *base,
671f0707 80 const char *pathname, unsigned mode, int stage, void *context)
782c2d65
DB
81{
82 int len;
83 struct cache_entry *ce;
c5326bd6 84 int pos;
782c2d65 85
782c2d65
DB
86 if (S_ISDIR(mode))
87 return READ_TREE_RECURSIVE;
88
6a0b0b6d 89 len = base->len + strlen(pathname);
a849735b 90 ce = make_empty_cache_entry(&the_index, len);
df46d77e 91 oidcpy(&ce->oid, oid);
6a0b0b6d
NTND
92 memcpy(ce->name, base->buf, base->len);
93 memcpy(ce->name + base->len, pathname, len - base->len);
b60e188c
TG
94 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
95 ce->ce_namelen = len;
782c2d65 96 ce->ce_mode = create_ce_mode(mode);
c5326bd6
JK
97
98 /*
99 * If the entry is the same as the current index, we can leave the old
100 * entry in place. Whether it is UPTODATE or not, checkout_entry will
101 * do the right thing.
102 */
103 pos = cache_name_pos(ce->name, ce->ce_namelen);
104 if (pos >= 0) {
105 struct cache_entry *old = active_cache[pos];
106 if (ce->ce_mode == old->ce_mode &&
4a7e27e9 107 oideq(&ce->oid, &old->oid)) {
c5326bd6 108 old->ce_flags |= CE_UPDATE;
a849735b 109 discard_cache_entry(ce);
c5326bd6
JK
110 return 0;
111 }
112 }
113
782c2d65
DB
114 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
115 return 0;
116}
117
18e4f405 118static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
782c2d65 119{
e092073d
NTND
120 read_tree_recursive(the_repository, tree, "", 0, 0,
121 pathspec, update_some, NULL);
782c2d65 122
782c2d65
DB
123 /* update the index with the given tree's info
124 * for all args, expanding wildcards, and exit
125 * with any non-zero return code.
126 */
127 return 0;
128}
129
9c5e6c80 130static int skip_same_name(const struct cache_entry *ce, int pos)
8fdcf312
JH
131{
132 while (++pos < active_nr &&
133 !strcmp(active_cache[pos]->name, ce->name))
134 ; /* skip */
135 return pos;
136}
137
9c5e6c80 138static int check_stage(int stage, const struct cache_entry *ce, int pos)
38901a48
JH
139{
140 while (pos < active_nr &&
141 !strcmp(active_cache[pos]->name, ce->name)) {
142 if (ce_stage(active_cache[pos]) == stage)
143 return 0;
144 pos++;
145 }
9f97ab08
ÆAB
146 if (stage == 2)
147 return error(_("path '%s' does not have our version"), ce->name);
148 else
149 return error(_("path '%s' does not have their version"), ce->name);
38901a48
JH
150}
151
9c5e6c80 152static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
0cf8581e 153{
fbbccd0a
JH
154 unsigned seen = 0;
155 const char *name = ce->name;
156
157 while (pos < active_nr) {
158 ce = active_cache[pos];
159 if (strcmp(name, ce->name))
160 break;
161 seen |= (1 << ce_stage(ce));
162 pos++;
163 }
164 if ((stages & seen) != stages)
165 return error(_("path '%s' does not have all necessary versions"),
166 name);
0cf8581e
JH
167 return 0;
168}
169
ce25e4c7 170static int checkout_stage(int stage, const struct cache_entry *ce, int pos,
0f086e6d 171 const struct checkout *state, int *nr_checkouts)
38901a48
JH
172{
173 while (pos < active_nr &&
174 !strcmp(active_cache[pos]->name, ce->name)) {
175 if (ce_stage(active_cache[pos]) == stage)
0f086e6d
NTND
176 return checkout_entry(active_cache[pos], state,
177 NULL, nr_checkouts);
38901a48
JH
178 pos++;
179 }
9f97ab08
ÆAB
180 if (stage == 2)
181 return error(_("path '%s' does not have our version"), ce->name);
182 else
183 return error(_("path '%s' does not have their version"), ce->name);
38901a48 184}
8fdcf312 185
0f086e6d 186static int checkout_merged(int pos, const struct checkout *state, int *nr_checkouts)
0cf8581e
JH
187{
188 struct cache_entry *ce = active_cache[pos];
189 const char *path = ce->name;
190 mmfile_t ancestor, ours, theirs;
191 int status;
60af7691 192 struct object_id oid;
0cf8581e 193 mmbuffer_t result_buf;
60af7691 194 struct object_id threeway[3];
335c6e40 195 unsigned mode = 0;
0cf8581e 196
fbbccd0a
JH
197 memset(threeway, 0, sizeof(threeway));
198 while (pos < active_nr) {
199 int stage;
200 stage = ce_stage(ce);
201 if (!stage || strcmp(path, ce->name))
202 break;
60af7691 203 oidcpy(&threeway[stage - 1], &ce->oid);
fbbccd0a
JH
204 if (stage == 2)
205 mode = create_ce_mode(ce->ce_mode);
206 pos++;
207 ce = active_cache[pos];
208 }
60af7691 209 if (is_null_oid(&threeway[1]) || is_null_oid(&threeway[2]))
fbbccd0a 210 return error(_("path '%s' does not have necessary versions"), path);
0cf8581e 211
d449347d 212 read_mmblob(&ancestor, &threeway[0]);
213 read_mmblob(&ours, &threeway[1]);
214 read_mmblob(&theirs, &threeway[2]);
0cf8581e 215
18b037a5
JN
216 /*
217 * NEEDSWORK: re-create conflicts from merges with
218 * merge.renormalize set, too
219 */
f0531a29 220 status = ll_merge(&result_buf, path, &ancestor, "base",
32eaa468
NTND
221 &ours, "ours", &theirs, "theirs",
222 state->istate, NULL);
0cf8581e
JH
223 free(ancestor.ptr);
224 free(ours.ptr);
225 free(theirs.ptr);
226 if (status < 0 || !result_buf.ptr) {
227 free(result_buf.ptr);
e8a8a4d7 228 return error(_("path '%s': cannot merge"), path);
0cf8581e
JH
229 }
230
231 /*
232 * NEEDSWORK:
233 * There is absolutely no reason to write this as a blob object
514e8039
JS
234 * and create a phony cache entry. This hack is primarily to get
235 * to the write_entry() machinery that massages the contents to
236 * work-tree format and writes out which only allows it for a
237 * cache entry. The code in write_entry() needs to be refactored
238 * to allow us to feed a <buffer, size, mode> instead of a cache
239 * entry. Such a refactoring would help merge_recursive as well
240 * (it also writes the merge result to the object database even
241 * when it may contain conflicts).
0cf8581e 242 */
a09c985e 243 if (write_object_file(result_buf.ptr, result_buf.size, blob_type, &oid))
e8a8a4d7 244 die(_("Unable to add merge result for '%s'"), path);
443a12f3 245 free(result_buf.ptr);
a849735b 246 ce = make_transient_cache_entry(mode, &oid, path, 2);
048f2762 247 if (!ce)
e8a8a4d7 248 die(_("make_cache_entry failed for path '%s'"), path);
0f086e6d 249 status = checkout_entry(ce, state, NULL, nr_checkouts);
a849735b 250 discard_cache_entry(ce);
0cf8581e
JH
251 return status;
252}
8fdcf312 253
b6312c27
NTND
254static int checkout_paths(const struct checkout_opts *opts,
255 const char *revision)
782c2d65
DB
256{
257 int pos;
68e3d629 258 struct checkout state = CHECKOUT_INIT;
782c2d65 259 static char *ps_matched;
60af7691 260 struct object_id rev;
782c2d65 261 struct commit *head;
d2b3691b 262 int errs = 0;
837e34eb 263 struct lock_file lock_file = LOCK_INIT;
1d1f689b 264 int nr_checkouts = 0, nr_unmerged = 0;
b6312c27
NTND
265
266 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
267 die(_("'%s' cannot be used with updating paths"), "--track");
268
269 if (opts->new_branch_log)
270 die(_("'%s' cannot be used with updating paths"), "-l");
271
272 if (opts->force && opts->patch_mode)
273 die(_("'%s' cannot be used with updating paths"), "-f");
274
275 if (opts->force_detach)
276 die(_("'%s' cannot be used with updating paths"), "--detach");
277
278 if (opts->merge && opts->patch_mode)
279 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
280
281 if (opts->force && opts->merge)
282 die(_("'%s' cannot be used with %s"), "-f", "-m");
283
284 if (opts->new_branch)
285 die(_("Cannot update paths and switch to branch '%s' at the same time."),
286 opts->new_branch);
287
288 if (opts->patch_mode)
289 return run_add_interactive(revision, "--patch=checkout",
480ca644 290 &opts->pathspec);
b6312c27 291
fb4a8464 292 repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
5ab2a2da 293 if (read_cache_preload(&opts->pathspec) < 0)
e923a8ab 294 return error(_("index file corrupt"));
75336878 295
e51e3057 296 if (opts->source_tree)
18e4f405 297 read_tree_some(opts->source_tree, &opts->pathspec);
75336878 298
8b54c234 299 ps_matched = xcalloc(opts->pathspec.nr, 1);
782c2d65 300
e721c154
NTND
301 /*
302 * Make sure all pathspecs participated in locating the paths
303 * to be checked out.
304 */
782c2d65
DB
305 for (pos = 0; pos < active_nr; pos++) {
306 struct cache_entry *ce = active_cache[pos];
e721c154 307 ce->ce_flags &= ~CE_MATCHED;
08d595dc
NTND
308 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
309 continue;
e51e3057 310 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
e721c154
NTND
311 /*
312 * "git checkout tree-ish -- path", but this entry
313 * is in the original index; it will not be checked
314 * out to the working tree and it does not matter
315 * if pathspec matched this entry. We will not do
316 * anything to this entry at all.
317 */
0a1283bc 318 continue;
e721c154
NTND
319 /*
320 * Either this entry came from the tree-ish we are
321 * checking the paths out of, or we are checking out
322 * of the index.
323 *
324 * If it comes from the tree-ish, we already know it
325 * matches the pathspec and could just stamp
326 * CE_MATCHED to it from update_some(). But we still
327 * need ps_matched and read_tree_recursive (and
328 * eventually tree_entry_interesting) cannot fill
329 * ps_matched yet. Once it can, we can avoid calling
330 * match_pathspec() for _all_ entries when
331 * opts->source_tree != NULL.
332 */
6d2df284 333 if (ce_path_match(&the_index, ce, &opts->pathspec, ps_matched))
e721c154 334 ce->ce_flags |= CE_MATCHED;
782c2d65
DB
335 }
336
17ddc66e 337 if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
e721c154 338 free(ps_matched);
782c2d65 339 return 1;
e721c154
NTND
340 }
341 free(ps_matched);
782c2d65 342
4421a823
JH
343 /* "checkout -m path" to recreate conflicted state */
344 if (opts->merge)
e721c154 345 unmerge_marked_index(&the_index);
4421a823 346
8fdcf312
JH
347 /* Any unmerged paths? */
348 for (pos = 0; pos < active_nr; pos++) {
9c5e6c80 349 const struct cache_entry *ce = active_cache[pos];
e721c154 350 if (ce->ce_flags & CE_MATCHED) {
8fdcf312
JH
351 if (!ce_stage(ce))
352 continue;
db941099 353 if (opts->force) {
e8a8a4d7 354 warning(_("path '%s' is unmerged"), ce->name);
f9022075
SB
355 } else if (opts->writeout_stage) {
356 errs |= check_stage(opts->writeout_stage, ce, pos);
0cf8581e 357 } else if (opts->merge) {
fbbccd0a 358 errs |= check_stages((1<<2) | (1<<3), ce, pos);
db941099
JH
359 } else {
360 errs = 1;
e8a8a4d7 361 error(_("path '%s' is unmerged"), ce->name);
db941099 362 }
8fdcf312
JH
363 pos = skip_same_name(ce, pos) - 1;
364 }
365 }
366 if (errs)
367 return 1;
368
d2b3691b 369 /* Now we are committed to check them out */
782c2d65
DB
370 state.force = 1;
371 state.refresh_cache = 1;
d4a2024a 372 state.istate = &the_index;
2841e8f8
LS
373
374 enable_delayed_checkout(&state);
782c2d65
DB
375 for (pos = 0; pos < active_nr; pos++) {
376 struct cache_entry *ce = active_cache[pos];
e721c154 377 if (ce->ce_flags & CE_MATCHED) {
8fdcf312 378 if (!ce_stage(ce)) {
0f086e6d
NTND
379 errs |= checkout_entry(ce, &state,
380 NULL, &nr_checkouts);
8fdcf312
JH
381 continue;
382 }
f9022075 383 if (opts->writeout_stage)
0f086e6d
NTND
384 errs |= checkout_stage(opts->writeout_stage,
385 ce, pos,
386 &state, &nr_checkouts);
f9022075 387 else if (opts->merge)
0f086e6d 388 errs |= checkout_merged(pos, &state,
1d1f689b 389 &nr_unmerged);
8fdcf312 390 pos = skip_same_name(ce, pos) - 1;
782c2d65
DB
391 }
392 }
0f086e6d
NTND
393 errs |= finish_delayed_checkout(&state, &nr_checkouts);
394
395 if (opts->count_checkout_paths) {
1d1f689b
NTND
396 if (nr_unmerged)
397 fprintf_ln(stderr, Q_("Recreated %d merge conflict",
398 "Recreated %d merge conflicts",
399 nr_unmerged),
400 nr_unmerged);
0f086e6d 401 if (opts->source_tree)
3c5883b3
NTND
402 fprintf_ln(stderr, Q_("Updated %d path from %s",
403 "Updated %d paths from %s",
0f086e6d
NTND
404 nr_checkouts),
405 nr_checkouts,
406 find_unique_abbrev(&opts->source_tree->object.oid,
407 DEFAULT_ABBREV));
1d1f689b 408 else if (!nr_unmerged || nr_checkouts)
3c5883b3
NTND
409 fprintf_ln(stderr, Q_("Updated %d path from the index",
410 "Updated %d paths from the index",
0f086e6d
NTND
411 nr_checkouts),
412 nr_checkouts);
413 }
782c2d65 414
837e34eb 415 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
e8a8a4d7 416 die(_("unable to write new index file"));
75336878 417
34c290a6 418 read_ref_full("HEAD", 0, &rev, NULL);
21e1ee8f 419 head = lookup_commit_reference_gently(the_repository, &rev, 1);
782c2d65 420
d2b3691b
JH
421 errs |= post_checkout_hook(head, head, 0);
422 return errs;
782c2d65
DB
423}
424
a2b4994c
NTND
425static void show_local_changes(struct object *head,
426 const struct diff_options *opts)
782c2d65
DB
427{
428 struct rev_info rev;
429 /* I think we want full paths, even if we're in a subdirectory. */
2abf3503 430 repo_init_revisions(the_repository, &rev, NULL);
175f6e59 431 rev.diffopt.flags = opts->flags;
782c2d65 432 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
28452655 433 diff_setup_done(&rev.diffopt);
782c2d65
DB
434 add_pending_object(&rev, head, NULL);
435 run_diff_index(&rev, 0);
436}
437
b3c0494a 438static void describe_detached_head(const char *msg, struct commit *commit)
782c2d65 439{
f285a2d7 440 struct strbuf sb = STRBUF_INIT;
ca69d4d5 441
3c621839
JK
442 if (!parse_commit(commit))
443 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
ca69d4d5
AR
444 if (print_sha1_ellipsis()) {
445 fprintf(stderr, "%s %s... %s\n", msg,
aab9583f 446 find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
ca69d4d5
AR
447 } else {
448 fprintf(stderr, "%s %s %s\n", msg,
aab9583f 449 find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV), sb.buf);
ca69d4d5 450 }
782c2d65
DB
451 strbuf_release(&sb);
452}
453
a2b4994c
NTND
454static int reset_tree(struct tree *tree, const struct checkout_opts *o,
455 int worktree, int *writeout_error)
782c2d65
DB
456{
457 struct unpack_trees_options opts;
458 struct tree_desc tree_desc;
bc052d7f 459
782c2d65
DB
460 memset(&opts, 0, sizeof(opts));
461 opts.head_idx = -1;
6286a08d
JH
462 opts.update = worktree;
463 opts.skip_unmerged = !worktree;
782c2d65
DB
464 opts.reset = 1;
465 opts.merge = 1;
466 opts.fn = oneway_merge;
870ebdb9 467 opts.verbose_update = o->show_progress;
34110cd4
LT
468 opts.src_index = &the_index;
469 opts.dst_index = &the_index;
782c2d65
DB
470 parse_tree(tree);
471 init_tree_desc(&tree_desc, tree->buffer, tree->size);
291d823e
JH
472 switch (unpack_trees(1, &tree_desc, &opts)) {
473 case -2:
a2b4994c 474 *writeout_error = 1;
291d823e
JH
475 /*
476 * We return 0 nevertheless, as the index is all right
477 * and more importantly we have made best efforts to
478 * update paths in the work tree, and we cannot revert
479 * them.
480 */
1cf01a34 481 /* fallthrough */
291d823e
JH
482 case 0:
483 return 0;
484 default:
84a5750b 485 return 128;
291d823e 486 }
782c2d65
DB
487}
488
782c2d65
DB
489struct branch_info {
490 const char *name; /* The short name used */
491 const char *path; /* The full name of a real branch */
492 struct commit *commit; /* The named commit */
5883034c
NTND
493 /*
494 * if not null the branch is detached because it's already
495 * checked out in this checkout
496 */
497 char *checkout;
782c2d65
DB
498};
499
500static void setup_branch_path(struct branch_info *branch)
501{
f285a2d7 502 struct strbuf buf = STRBUF_INIT;
ae5a6c36 503
fd4692ff 504 strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
a552de75 505 if (strcmp(buf.buf, branch->name))
ae5a6c36 506 branch->name = xstrdup(buf.buf);
a552de75 507 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
782c2d65
DB
508 branch->path = strbuf_detach(&buf, NULL);
509}
510
fa655d84
BP
511/*
512 * Skip merging the trees, updating the index and working directory if and
513 * only if we are creating a new branch via "git checkout -b <new_branch>."
514 */
515static int skip_merge_working_tree(const struct checkout_opts *opts,
516 const struct branch_info *old_branch_info,
517 const struct branch_info *new_branch_info)
518{
519 /*
520 * Do the merge if sparse checkout is on and the user has not opted in
521 * to the optimized behavior
522 */
523 if (core_apply_sparse_checkout && !checkout_optimize_new_branch)
524 return 0;
525
526 /*
527 * We must do the merge if we are actually moving to a new commit.
528 */
529 if (!old_branch_info->commit || !new_branch_info->commit ||
e43d2dcc
JK
530 !oideq(&old_branch_info->commit->object.oid,
531 &new_branch_info->commit->object.oid))
fa655d84
BP
532 return 0;
533
534 /*
535 * opts->patch_mode cannot be used with switching branches so is
536 * not tested here
537 */
538
539 /*
540 * opts->quiet only impacts output so doesn't require a merge
541 */
542
543 /*
544 * Honor the explicit request for a three-way merge or to throw away
545 * local changes
546 */
547 if (opts->merge || opts->force)
548 return 0;
549
550 /*
551 * --detach is documented as "updating the index and the files in the
552 * working tree" but this optimization skips those steps so fall through
553 * to the regular code path.
554 */
555 if (opts->force_detach)
556 return 0;
557
558 /*
559 * opts->writeout_stage cannot be used with switching branches so is
560 * not tested here
561 */
562
563 /*
564 * Honor the explicit ignore requests
565 */
566 if (!opts->overwrite_ignore || opts->ignore_skipworktree ||
567 opts->ignore_other_worktrees)
568 return 0;
569
570 /*
571 * opts->show_progress only impacts output so doesn't require a merge
572 */
573
574 /*
575 * If we aren't creating a new branch any changes or updates will
576 * happen in the existing branch. Since that could only be updating
577 * the index and working directory, we don't want to skip those steps
578 * or we've defeated any purpose in running the command.
579 */
580 if (!opts->new_branch)
581 return 0;
582
583 /*
584 * new_branch_force is defined to "create/reset and checkout a branch"
585 * so needs to go through the merge to do the reset
586 */
587 if (opts->new_branch_force)
588 return 0;
589
590 /*
591 * A new orphaned branch requrires the index and the working tree to be
592 * adjusted to <start_point>
593 */
594 if (opts->new_orphan_branch)
595 return 0;
596
597 /*
598 * Remaining variables are not checkout options but used to track state
599 */
600
8424bfd4
BP
601 /*
602 * Do the merge if this is the initial checkout. We cannot use
603 * is_cache_unborn() here because the index hasn't been loaded yet
604 * so cache_nr and timestamp.sec are always zero.
605 */
606 if (!file_exists(get_index_file()))
607 return 0;
608
fa655d84
BP
609 return 1;
610}
611
a2b4994c 612static int merge_working_tree(const struct checkout_opts *opts,
c8a3ea1f
BW
613 struct branch_info *old_branch_info,
614 struct branch_info *new_branch_info,
a2b4994c 615 int *writeout_error)
782c2d65
DB
616{
617 int ret;
837e34eb 618 struct lock_file lock_file = LOCK_INIT;
b96524f8 619
837e34eb 620 hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
53996fe5 621 if (read_cache_preload(NULL) < 0)
e923a8ab 622 return error(_("index file corrupt"));
782c2d65 623
cfc5789a 624 resolve_undo_clear();
782c2d65 625 if (opts->force) {
2e27bd77
DS
626 ret = reset_tree(get_commit_tree(new_branch_info->commit),
627 opts, 1, writeout_error);
782c2d65
DB
628 if (ret)
629 return ret;
630 } else {
631 struct tree_desc trees[2];
632 struct tree *tree;
633 struct unpack_trees_options topts;
bc052d7f 634
782c2d65
DB
635 memset(&topts, 0, sizeof(topts));
636 topts.head_idx = -1;
34110cd4
LT
637 topts.src_index = &the_index;
638 topts.dst_index = &the_index;
782c2d65 639
e294030f 640 setup_unpack_trees_porcelain(&topts, "checkout");
8ccba008 641
782c2d65
DB
642 refresh_cache(REFRESH_QUIET);
643
644 if (unmerged_cache()) {
e8a8a4d7 645 error(_("you need to resolve your current index first"));
04c9e11f 646 return 1;
782c2d65 647 }
04c9e11f
JH
648
649 /* 2-way merge to the new branch */
fa7b3c2f 650 topts.initial_checkout = is_cache_unborn();
04c9e11f
JH
651 topts.update = 1;
652 topts.merge = 1;
c8a3ea1f 653 topts.gently = opts->merge && old_branch_info->commit;
870ebdb9 654 topts.verbose_update = opts->show_progress;
04c9e11f 655 topts.fn = twoway_merge;
c1d7036b
NTND
656 if (opts->overwrite_ignore) {
657 topts.dir = xcalloc(1, sizeof(*topts.dir));
658 topts.dir->flags |= DIR_SHOW_IGNORED;
659 setup_standard_excludes(topts.dir);
660 }
c8a3ea1f
BW
661 tree = parse_tree_indirect(old_branch_info->commit ?
662 &old_branch_info->commit->object.oid :
eb0ccfd7 663 the_hash_algo->empty_tree);
04c9e11f 664 init_tree_desc(&trees[0], tree->buffer, tree->size);
c8a3ea1f 665 tree = parse_tree_indirect(&new_branch_info->commit->object.oid);
04c9e11f
JH
666 init_tree_desc(&trees[1], tree->buffer, tree->size);
667
291d823e 668 ret = unpack_trees(2, trees, &topts);
1c41d280 669 clear_unpack_trees_porcelain(&topts);
49d833dc 670 if (ret == -1) {
782c2d65
DB
671 /*
672 * Unpack couldn't do a trivial merge; either
673 * give up or do a real merge, depending on
674 * whether the merge flag was used.
675 */
676 struct tree *result;
677 struct tree *work;
8a2fce18 678 struct merge_options o;
a7256deb
NTND
679 struct strbuf sb = STRBUF_INIT;
680
782c2d65
DB
681 if (!opts->merge)
682 return 1;
64da3ae5
JH
683
684 /*
c8a3ea1f 685 * Without old_branch_info->commit, the below is the same as
64da3ae5
JH
686 * the two-tree unpack we already tried and failed.
687 */
c8a3ea1f 688 if (!old_branch_info->commit)
64da3ae5 689 return 1;
782c2d65 690
a7256deb
NTND
691 if (repo_index_has_changes(the_repository,
692 get_commit_tree(old_branch_info->commit),
693 &sb))
694 warning(_("staged changes in the following files may be lost: %s"),
695 sb.buf);
696 strbuf_release(&sb);
697
782c2d65
DB
698 /* Do more real merge */
699
700 /*
701 * We update the index fully, then write the
702 * tree from the index, then merge the new
703 * branch with the current tree, with the old
704 * branch as the base. Then we reset the index
705 * (but not the working tree) to the new
706 * branch, leaving the working tree as the
707 * merged version, but skipping unmerged
708 * entries in the index.
709 */
710
610d55af 711 add_files_to_cache(NULL, NULL, 0);
7610fa57
JN
712 /*
713 * NEEDSWORK: carrying over local changes
714 * when branches have different end-of-line
715 * normalization (or clean+smudge rules) is
716 * a pain; plumb in an option to set
717 * o.renormalize?
718 */
0d6caa2d 719 init_merge_options(&o, the_repository);
8a2fce18
MV
720 o.verbosity = 0;
721 work = write_tree_from_memory(&o);
782c2d65 722
2e27bd77
DS
723 ret = reset_tree(get_commit_tree(new_branch_info->commit),
724 opts, 1,
a2b4994c 725 writeout_error);
782c2d65
DB
726 if (ret)
727 return ret;
c8a3ea1f
BW
728 o.ancestor = old_branch_info->name;
729 o.branch1 = new_branch_info->name;
8a2fce18 730 o.branch2 = "local";
2e27bd77
DS
731 ret = merge_trees(&o,
732 get_commit_tree(new_branch_info->commit),
733 work,
734 get_commit_tree(old_branch_info->commit),
735 &result);
f241ff0d
JS
736 if (ret < 0)
737 exit(128);
2e27bd77
DS
738 ret = reset_tree(get_commit_tree(new_branch_info->commit),
739 opts, 0,
a2b4994c 740 writeout_error);
548009c0 741 strbuf_release(&o.obuf);
84a5750b
JH
742 if (ret)
743 return ret;
782c2d65
DB
744 }
745 }
746
aecf567c
DT
747 if (!active_cache_tree)
748 active_cache_tree = cache_tree();
749
750 if (!cache_tree_fully_valid(active_cache_tree))
3fd13cbc 751 cache_tree_update(&the_index, WRITE_TREE_SILENT | WRITE_TREE_REPAIR);
aecf567c 752
837e34eb 753 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
e8a8a4d7 754 die(_("unable to write new index file"));
782c2d65 755
7fe4a728 756 if (!opts->force && !opts->quiet)
c8a3ea1f 757 show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
782c2d65
DB
758
759 return 0;
760}
761
c8a3ea1f 762static void report_tracking(struct branch_info *new_branch_info)
79a1e6b4 763{
6d21bf96 764 struct strbuf sb = STRBUF_INIT;
c8a3ea1f 765 struct branch *branch = branch_get(new_branch_info->name);
79a1e6b4 766
f39a757d 767 if (!format_tracking_info(branch, &sb, AHEAD_BEHIND_FULL))
79a1e6b4 768 return;
6d21bf96
JH
769 fputs(sb.buf, stdout);
770 strbuf_release(&sb);
b0030db3 771}
79a1e6b4 772
a2b4994c 773static void update_refs_for_switch(const struct checkout_opts *opts,
c8a3ea1f
BW
774 struct branch_info *old_branch_info,
775 struct branch_info *new_branch_info)
782c2d65 776{
f285a2d7 777 struct strbuf msg = STRBUF_INIT;
3bed291a 778 const char *old_desc, *reflog_msg;
782c2d65 779 if (opts->new_branch) {
3631bf77 780 if (opts->new_orphan_branch) {
341fb286
CW
781 char *refname;
782
783 refname = mkpathdup("refs/heads/%s", opts->new_orphan_branch);
784 if (opts->new_branch_log &&
785 !should_autocreate_reflog(refname)) {
1a83c240 786 int ret;
a4c653df 787 struct strbuf err = STRBUF_INIT;
3631bf77 788
abd0cd3a 789 ret = safe_create_reflog(refname, 1, &err);
1a83c240 790 if (ret) {
a4c653df
DT
791 fprintf(stderr, _("Can not do reflog for '%s': %s\n"),
792 opts->new_orphan_branch, err.buf);
793 strbuf_release(&err);
341fb286 794 free(refname);
3631bf77
EM
795 return;
796 }
abd0cd3a 797 strbuf_release(&err);
3631bf77 798 }
341fb286 799 free(refname);
3631bf77
EM
800 }
801 else
4edce172
NTND
802 create_branch(the_repository,
803 opts->new_branch, new_branch_info->name,
02ac9837 804 opts->new_branch_force ? 1 : 0,
39bd6f72 805 opts->new_branch_force ? 1 : 0,
e2bbd0cc 806 opts->new_branch_log,
f9a482e6 807 opts->quiet,
39bd6f72 808 opts->track);
c8a3ea1f
BW
809 new_branch_info->name = opts->new_branch;
810 setup_branch_path(new_branch_info);
782c2d65
DB
811 }
812
c8a3ea1f
BW
813 old_desc = old_branch_info->name;
814 if (!old_desc && old_branch_info->commit)
815 old_desc = oid_to_hex(&old_branch_info->commit->object.oid);
3bed291a
RR
816
817 reflog_msg = getenv("GIT_REFLOG_ACTION");
818 if (!reflog_msg)
819 strbuf_addf(&msg, "checkout: moving from %s to %s",
c8a3ea1f 820 old_desc ? old_desc : "(invalid)", new_branch_info->name);
3bed291a
RR
821 else
822 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
782c2d65 823
c8a3ea1f 824 if (!strcmp(new_branch_info->name, "HEAD") && !new_branch_info->path && !opts->force_detach) {
f8bd36a4 825 /* Nothing to do. */
c8a3ea1f
BW
826 } else if (opts->force_detach || !new_branch_info->path) { /* No longer on any branch. */
827 update_ref(msg.buf, "HEAD", &new_branch_info->commit->object.oid, NULL,
91774afc 828 REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);
f8bd36a4 829 if (!opts->quiet) {
c8a3ea1f 830 if (old_branch_info->path &&
779b88a9 831 advice_detached_head && !opts->force_detach)
c8a3ea1f
BW
832 detach_advice(new_branch_info->name);
833 describe_detached_head(_("HEAD is now at"), new_branch_info->commit);
f8bd36a4 834 }
c8a3ea1f
BW
835 } else if (new_branch_info->path) { /* Switch branches. */
836 if (create_symref("HEAD", new_branch_info->path, msg.buf) < 0)
4636f651 837 die(_("unable to update HEAD"));
782c2d65 838 if (!opts->quiet) {
c8a3ea1f 839 if (old_branch_info->path && !strcmp(new_branch_info->path, old_branch_info->path)) {
39bd6f72
JN
840 if (opts->new_branch_force)
841 fprintf(stderr, _("Reset branch '%s'\n"),
c8a3ea1f 842 new_branch_info->name);
39bd6f72
JN
843 else
844 fprintf(stderr, _("Already on '%s'\n"),
c8a3ea1f 845 new_branch_info->name);
08eaa4be
ÆAB
846 } else if (opts->new_branch) {
847 if (opts->branch_exists)
c8a3ea1f 848 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new_branch_info->name);
08eaa4be 849 else
c8a3ea1f 850 fprintf(stderr, _("Switched to a new branch '%s'\n"), new_branch_info->name);
08eaa4be 851 } else {
e8a8a4d7 852 fprintf(stderr, _("Switched to branch '%s'\n"),
c8a3ea1f 853 new_branch_info->name);
08eaa4be 854 }
782c2d65 855 }
c8a3ea1f
BW
856 if (old_branch_info->path && old_branch_info->name) {
857 if (!ref_exists(old_branch_info->path) && reflog_exists(old_branch_info->path))
858 delete_reflog(old_branch_info->path);
3631bf77 859 }
782c2d65 860 }
4edce172 861 remove_branch_state(the_repository);
782c2d65 862 strbuf_release(&msg);
32669671 863 if (!opts->quiet &&
c8a3ea1f
BW
864 (new_branch_info->path || (!opts->force_detach && !strcmp(new_branch_info->name, "HEAD"))))
865 report_tracking(new_branch_info);
782c2d65
DB
866}
867
468224e5 868static int add_pending_uninteresting_ref(const char *refname,
fcb615f5 869 const struct object_id *oid,
468224e5 870 int flags, void *cb_data)
8e2dc6ac 871{
a58a1b01 872 add_pending_oid(cb_data, refname, oid, UNINTERESTING);
5c08dc48
JK
873 return 0;
874}
8e2dc6ac
JH
875
876static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
877{
0be240cc 878 strbuf_addstr(sb, " ");
30e677e0 879 strbuf_add_unique_abbrev(sb, &commit->object.oid, DEFAULT_ABBREV);
0be240cc 880 strbuf_addch(sb, ' ');
3c621839
JK
881 if (!parse_commit(commit))
882 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
8e2dc6ac
JH
883 strbuf_addch(sb, '\n');
884}
885
886#define ORPHAN_CUTOFF 4
887static void suggest_reattach(struct commit *commit, struct rev_info *revs)
888{
889 struct commit *c, *last = NULL;
890 struct strbuf sb = STRBUF_INIT;
891 int lost = 0;
892 while ((c = get_revision(revs)) != NULL) {
893 if (lost < ORPHAN_CUTOFF)
894 describe_one_orphan(&sb, c);
895 last = c;
896 lost++;
897 }
898 if (ORPHAN_CUTOFF < lost) {
899 int more = lost - ORPHAN_CUTOFF;
900 if (more == 1)
901 describe_one_orphan(&sb, last);
902 else
f06f08b7 903 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
8e2dc6ac
JH
904 }
905
906 fprintf(stderr,
f06f08b7
ÆAB
907 Q_(
908 /* The singular version */
909 "Warning: you are leaving %d commit behind, "
910 "not connected to\n"
911 "any of your branches:\n\n"
0faf2474 912 "%s\n",
f06f08b7
ÆAB
913 /* The plural version */
914 "Warning: you are leaving %d commits behind, "
8e2dc6ac
JH
915 "not connected to\n"
916 "any of your branches:\n\n"
f807b3dc 917 "%s\n",
f06f08b7
ÆAB
918 /* Give ngettext() the count */
919 lost),
920 lost,
f807b3dc 921 sb.buf);
8e2dc6ac 922 strbuf_release(&sb);
f807b3dc
JH
923
924 if (advice_detached_head)
925 fprintf(stderr,
fc792ca8
TS
926 Q_(
927 /* The singular version */
928 "If you want to keep it by creating a new branch, "
929 "this may be a good time\nto do so with:\n\n"
930 " git branch <new-branch-name> %s\n\n",
931 /* The plural version */
f807b3dc
JH
932 "If you want to keep them by creating a new branch, "
933 "this may be a good time\nto do so with:\n\n"
fc792ca8
TS
934 " git branch <new-branch-name> %s\n\n",
935 /* Give ngettext() the count */
936 lost),
aab9583f 937 find_unique_abbrev(&commit->object.oid, DEFAULT_ABBREV));
8e2dc6ac
JH
938}
939
940/*
941 * We are about to leave commit that was at the tip of a detached
942 * HEAD. If it is not reachable from any ref, this is the last chance
943 * for the user to do so without resorting to reflog.
944 */
c8a3ea1f 945static void orphaned_commit_warning(struct commit *old_commit, struct commit *new_commit)
8e2dc6ac 946{
8e2dc6ac 947 struct rev_info revs;
c8a3ea1f 948 struct object *object = &old_commit->object;
8e2dc6ac 949
2abf3503 950 repo_init_revisions(the_repository, &revs, NULL);
468224e5
RS
951 setup_revisions(0, NULL, &revs, NULL);
952
953 object->flags &= ~UNINTERESTING;
f2fd0760 954 add_pending_object(&revs, object, oid_to_hex(&object->oid));
468224e5 955
fcb615f5 956 for_each_ref(add_pending_uninteresting_ref, &revs);
c8a3ea1f 957 add_pending_oid(&revs, "HEAD", &new_commit->object.oid, UNINTERESTING);
468224e5 958
8e2dc6ac 959 if (prepare_revision_walk(&revs))
6c80cd29 960 die(_("internal error in revision walk"));
c8a3ea1f
BW
961 if (!(old_commit->object.flags & UNINTERESTING))
962 suggest_reattach(old_commit, &revs);
8e2dc6ac 963 else
c8a3ea1f 964 describe_detached_head(_("Previous HEAD position was"), old_commit);
5c08dc48 965
b2ccdf7f 966 /* Clean up objects used, as they will be reused. */
a9a03fa0 967 clear_commit_marks_all(ALL_REV_FLAGS);
8e2dc6ac
JH
968}
969
e51e3057 970static int switch_branches(const struct checkout_opts *opts,
c8a3ea1f 971 struct branch_info *new_branch_info)
782c2d65
DB
972{
973 int ret = 0;
c8a3ea1f 974 struct branch_info old_branch_info;
96ec7b1e 975 void *path_to_free;
60af7691 976 struct object_id rev;
a2b4994c 977 int flag, writeout_error = 0;
c8a3ea1f
BW
978 memset(&old_branch_info, 0, sizeof(old_branch_info));
979 old_branch_info.path = path_to_free = resolve_refdup("HEAD", 0, &rev, &flag);
980 if (old_branch_info.path)
21e1ee8f 981 old_branch_info.commit = lookup_commit_reference_gently(the_repository, &rev, 1);
96ec7b1e 982 if (!(flag & REF_ISSYMREF))
c8a3ea1f 983 old_branch_info.path = NULL;
782c2d65 984
c8a3ea1f
BW
985 if (old_branch_info.path)
986 skip_prefix(old_branch_info.path, "refs/heads/", &old_branch_info.name);
782c2d65 987
c8a3ea1f
BW
988 if (!new_branch_info->name) {
989 new_branch_info->name = "HEAD";
990 new_branch_info->commit = old_branch_info.commit;
991 if (!new_branch_info->commit)
e8a8a4d7 992 die(_("You are on a branch yet to be born"));
c8a3ea1f 993 parse_commit_or_die(new_branch_info->commit);
782c2d65
DB
994 }
995
fa655d84
BP
996 /* optimize the "checkout -b <new_branch> path */
997 if (skip_merge_working_tree(opts, &old_branch_info, new_branch_info)) {
998 if (!checkout_optimize_new_branch && !opts->quiet) {
999 if (read_cache_preload(NULL) < 0)
1000 return error(_("index file corrupt"));
1001 show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
1002 }
1003 } else {
1004 ret = merge_working_tree(opts, &old_branch_info, new_branch_info, &writeout_error);
1005 if (ret) {
1006 free(path_to_free);
1007 return ret;
1008 }
96ec7b1e 1009 }
782c2d65 1010
c8a3ea1f
BW
1011 if (!opts->quiet && !old_branch_info.path && old_branch_info.commit && new_branch_info->commit != old_branch_info.commit)
1012 orphaned_commit_warning(old_branch_info.commit, new_branch_info->commit);
77ebd56d 1013
c8a3ea1f 1014 update_refs_for_switch(opts, &old_branch_info, new_branch_info);
782c2d65 1015
c8a3ea1f 1016 ret = post_checkout_hook(old_branch_info.commit, new_branch_info->commit, 1);
96ec7b1e 1017 free(path_to_free);
a2b4994c 1018 return ret || writeout_error;
782c2d65
DB
1019}
1020
0cf8581e
JH
1021static int git_checkout_config(const char *var, const char *value, void *cb)
1022{
fa655d84
BP
1023 if (!strcmp(var, "checkout.optimizenewbranch")) {
1024 checkout_optimize_new_branch = git_config_bool(var, value);
1025 return 0;
1026 }
1027
175f6e59
JS
1028 if (!strcmp(var, "diff.ignoresubmodules")) {
1029 struct checkout_opts *opts = cb;
1030 handle_ignore_submodules_arg(&opts->diff_options, value);
1031 return 0;
1032 }
23b4c7bc 1033
59556548 1034 if (starts_with(var, "submodule."))
7463e2ec 1035 return git_default_submodule_config(var, value, NULL);
23b4c7bc 1036
175f6e59 1037 return git_xmerge_config(var, value, NULL);
0cf8581e
JH
1038}
1039
09ebad6f
JN
1040static int parse_branchname_arg(int argc, const char **argv,
1041 int dwim_new_local_branch_ok,
c8a3ea1f 1042 struct branch_info *new_branch_info,
10f102be 1043 struct checkout_opts *opts,
3c87aa94
ÆAB
1044 struct object_id *rev,
1045 int *dwim_remotes_matched)
09ebad6f 1046{
10f102be
NTND
1047 struct tree **source_tree = &opts->source_tree;
1048 const char **new_branch = &opts->new_branch;
09ebad6f 1049 int argcount = 0;
60af7691 1050 struct object_id branch_rev;
09ebad6f 1051 const char *arg;
bca39695
MM
1052 int dash_dash_pos;
1053 int has_dash_dash = 0;
1054 int i;
09ebad6f
JN
1055
1056 /*
1057 * case 1: git checkout <ref> -- [<paths>]
1058 *
1059 * <ref> must be a valid tree, everything after the '--' must be
1060 * a path.
1061 *
1062 * case 2: git checkout -- [<paths>]
1063 *
1064 * everything after the '--' must be paths.
1065 *
a047fafc 1066 * case 3: git checkout <something> [--]
09ebad6f 1067 *
a047fafc
MM
1068 * (a) If <something> is a commit, that is to
1069 * switch to the branch or detach HEAD at it. As a special case,
1070 * if <something> is A...B (missing A or B means HEAD but you can
1071 * omit at most one side), and if there is a unique merge base
1072 * between A and B, A...B names that merge base.
09ebad6f 1073 *
a047fafc 1074 * (b) If <something> is _not_ a commit, either "--" is present
01689909 1075 * or <something> is not a path, no -t or -b was given, and
a047fafc 1076 * and there is a tracking branch whose name is <something>
8d7b558b
ÆAB
1077 * in one and only one remote (or if the branch exists on the
1078 * remote named in checkout.defaultRemote), then this is a
1079 * short-hand to fork local <something> from that
1080 * remote-tracking branch.
09ebad6f 1081 *
a047fafc
MM
1082 * (c) Otherwise, if "--" is present, treat it like case (1).
1083 *
1084 * (d) Otherwise :
1085 * - if it's a reference, treat it like case (1)
1086 * - else if it's a path, treat it like case (2)
1087 * - else: fail.
1088 *
1089 * case 4: git checkout <something> <paths>
1090 *
1091 * The first argument must not be ambiguous.
09ebad6f
JN
1092 * - If it's *only* a reference, treat it like case (1).
1093 * - If it's only a path, treat it like case (2).
1094 * - else: fail.
1095 *
1096 */
1097 if (!argc)
1098 return 0;
1099
09ebad6f 1100 arg = argv[0];
bca39695
MM
1101 dash_dash_pos = -1;
1102 for (i = 0; i < argc; i++) {
1103 if (!strcmp(argv[i], "--")) {
1104 dash_dash_pos = i;
1105 break;
1106 }
1107 }
1108 if (dash_dash_pos == 0)
1109 return 1; /* case (2) */
1110 else if (dash_dash_pos == 1)
1111 has_dash_dash = 1; /* case (3) or (1) */
1112 else if (dash_dash_pos >= 2)
1113 die(_("only one reference expected, %d given."), dash_dash_pos);
0f086e6d 1114 opts->count_checkout_paths = !opts->quiet && !has_dash_dash;
09ebad6f
JN
1115
1116 if (!strcmp(arg, "-"))
1117 arg = "@{-1}";
1118
151b2911 1119 if (get_oid_mb(arg, rev)) {
a047fafc
MM
1120 /*
1121 * Either case (3) or (4), with <something> not being
1122 * a commit, or an attempt to use case (1) with an
1123 * invalid ref.
1124 *
1125 * It's likely an error, but we need to find out if
1126 * we should auto-create the branch, case (3).(b).
1127 */
1128 int recover_with_dwim = dwim_new_local_branch_ok;
1129
be4908f1
NTND
1130 int could_be_checkout_paths = !has_dash_dash &&
1131 check_filename(opts->prefix, arg);
1132
1133 if (!has_dash_dash && !no_wildcard(arg))
a047fafc 1134 recover_with_dwim = 0;
be4908f1 1135
a047fafc
MM
1136 /*
1137 * Accept "git checkout foo" and "git checkout foo --"
1138 * as candidates for dwim.
1139 */
1140 if (!(argc == 1 && !has_dash_dash) &&
1141 !(argc == 2 && has_dash_dash))
1142 recover_with_dwim = 0;
1143
1144 if (recover_with_dwim) {
3c87aa94
ÆAB
1145 const char *remote = unique_tracking_name(arg, rev,
1146 dwim_remotes_matched);
a047fafc 1147 if (remote) {
be4908f1
NTND
1148 if (could_be_checkout_paths)
1149 die(_("'%s' could be both a local file and a tracking branch.\n"
1150 "Please use -- (and optionally --no-guess) to disambiguate"),
1151 arg);
a047fafc
MM
1152 *new_branch = arg;
1153 arg = remote;
1154 /* DWIMmed to create local branch, case (3).(b) */
1155 } else {
1156 recover_with_dwim = 0;
1157 }
1158 }
1159
1160 if (!recover_with_dwim) {
1161 if (has_dash_dash)
1162 die(_("invalid reference: %s"), arg);
09ebad6f
JN
1163 return argcount;
1164 }
1165 }
1166
1167 /* we can't end up being in (2) anymore, eat the argument */
1168 argcount++;
1169 argv++;
1170 argc--;
1171
c8a3ea1f
BW
1172 new_branch_info->name = arg;
1173 setup_branch_path(new_branch_info);
09ebad6f 1174
c8a3ea1f
BW
1175 if (!check_refname_format(new_branch_info->path, 0) &&
1176 !read_ref(new_branch_info->path, &branch_rev))
60af7691 1177 oidcpy(rev, &branch_rev);
09ebad6f 1178 else
c8a3ea1f 1179 new_branch_info->path = NULL; /* not an existing branch */
09ebad6f 1180
21e1ee8f 1181 new_branch_info->commit = lookup_commit_reference_gently(the_repository, rev, 1);
c8a3ea1f 1182 if (!new_branch_info->commit) {
09ebad6f 1183 /* not a commit */
a9dbc179 1184 *source_tree = parse_tree_indirect(rev);
09ebad6f 1185 } else {
c8a3ea1f 1186 parse_commit_or_die(new_branch_info->commit);
2e27bd77 1187 *source_tree = get_commit_tree(new_branch_info->commit);
09ebad6f
JN
1188 }
1189
1190 if (!*source_tree) /* case (1): want a tree */
6c80cd29 1191 die(_("reference is not a tree: %s"), arg);
7f82b24e 1192 if (!has_dash_dash) { /* case (3).(d) -> (1) */
09ebad6f
JN
1193 /*
1194 * Do not complain the most common case
1195 * git checkout branch
1196 * even if there happen to be a file called 'branch';
1197 * it would be extremely annoying.
1198 */
1199 if (argc)
b829b943 1200 verify_non_filename(opts->prefix, arg);
09ebad6f
JN
1201 } else {
1202 argcount++;
1203 argv++;
1204 argc--;
1205 }
1206
1207 return argcount;
1208}
1209
a2b4994c 1210static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
abe19980
JH
1211{
1212 int status;
1213 struct strbuf branch_ref = STRBUF_INIT;
1214
8ced1aa0
CW
1215 if (!opts->new_branch)
1216 die(_("You are on a branch yet to be born"));
abe19980
JH
1217 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1218 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1219 strbuf_release(&branch_ref);
afa8c07a
JK
1220 if (!opts->quiet)
1221 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1222 opts->new_branch);
abe19980
JH
1223 return status;
1224}
1225
b6312c27 1226static int checkout_branch(struct checkout_opts *opts,
c8a3ea1f 1227 struct branch_info *new_branch_info)
b6312c27 1228{
817b345a 1229 if (opts->pathspec.nr)
b6312c27
NTND
1230 die(_("paths cannot be used with switching branches"));
1231
1232 if (opts->patch_mode)
1233 die(_("'%s' cannot be used with switching branches"),
1234 "--patch");
1235
1236 if (opts->writeout_stage)
1237 die(_("'%s' cannot be used with switching branches"),
1238 "--ours/--theirs");
1239
1240 if (opts->force && opts->merge)
1241 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1242
1243 if (opts->force_detach && opts->new_branch)
1244 die(_("'%s' cannot be used with '%s'"),
1245 "--detach", "-b/-B/--orphan");
1246
1247 if (opts->new_orphan_branch) {
1248 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1249 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1250 } else if (opts->force_detach) {
1251 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1252 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1253 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1254 opts->track = git_branch_track;
1255
c8a3ea1f 1256 if (new_branch_info->name && !new_branch_info->commit)
b6312c27 1257 die(_("Cannot switch branch to a non-commit '%s'"),
c8a3ea1f 1258 new_branch_info->name);
b6312c27 1259
c8a3ea1f 1260 if (new_branch_info->path && !opts->force_detach && !opts->new_branch &&
c265c533 1261 !opts->ignore_other_worktrees) {
e1c1ab9d 1262 int flag;
efbd4fdf 1263 char *head_ref = resolve_refdup("HEAD", 0, NULL, &flag);
e1c1ab9d 1264 if (head_ref &&
c8a3ea1f
BW
1265 (!(flag & REF_ISSYMREF) || strcmp(head_ref, new_branch_info->path)))
1266 die_if_checked_out(new_branch_info->path, 1);
e1c1ab9d
NTND
1267 free(head_ref);
1268 }
1269
c8a3ea1f 1270 if (!new_branch_info->commit && opts->new_branch) {
60af7691 1271 struct object_id rev;
b6312c27
NTND
1272 int flag;
1273
34c290a6 1274 if (!read_ref_full("HEAD", 0, &rev, &flag) &&
60af7691 1275 (flag & REF_ISSYMREF) && is_null_oid(&rev))
b6312c27
NTND
1276 return switch_unborn_to_new_branch(opts);
1277 }
c8a3ea1f 1278 return switch_branches(opts, new_branch_info);
b6312c27
NTND
1279}
1280
782c2d65
DB
1281int cmd_checkout(int argc, const char **argv, const char *prefix)
1282{
1283 struct checkout_opts opts;
c8a3ea1f 1284 struct branch_info new_branch_info;
eac5a401 1285 char *conflict_style = NULL;
be4908f1 1286 int dwim_new_local_branch, no_dwim_new_local_branch = 0;
3c87aa94 1287 int dwim_remotes_matched = 0;
782c2d65 1288 struct option options[] = {
e05a1093
NTND
1289 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1290 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1291 N_("create and checkout a new branch")),
1292 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1293 N_("create/reset and checkout a branch")),
d5d09d47 1294 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
e923a8ab 1295 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach HEAD at named commit")),
e05a1093 1296 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
9ed36cfa 1297 BRANCH_TRACK_EXPLICIT),
e703d711 1298 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
3fe735e7
NTND
1299 OPT_SET_INT_F('2', "ours", &opts.writeout_stage,
1300 N_("checkout our version for unmerged files"),
1301 2, PARSE_OPT_NONEG),
1302 OPT_SET_INT_F('3', "theirs", &opts.writeout_stage,
1303 N_("checkout their version for unmerged files"),
1304 3, PARSE_OPT_NONEG),
77afafb2
NTND
1305 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)"),
1306 PARSE_OPT_NOCOMPLETE),
d5d09d47 1307 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
77afafb2
NTND
1308 OPT_BOOL_F(0, "overwrite-ignore", &opts.overwrite_ignore,
1309 N_("update ignored files (default)"),
1310 PARSE_OPT_NOCOMPLETE),
e05a1093
NTND
1311 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1312 N_("conflict style (merge or diff3)")),
d5d09d47 1313 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
08d595dc
NTND
1314 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1315 N_("do not limit pathspecs to sparse entries only")),
be4908f1
NTND
1316 OPT_BOOL(0, "no-guess", &no_dwim_new_local_branch,
1317 N_("do not second guess 'git checkout <no-such-branch>'")),
1d0fa898
NTND
1318 OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
1319 N_("do not check if another worktree is holding the given ref")),
58b75bd6 1320 { OPTION_CALLBACK, 0, "recurse-submodules", NULL,
1fc458d9 1321 "checkout", "control recursive updating of submodules",
d7a3803f 1322 PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
870ebdb9 1323 OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
b249b552 1324 OPT_END(),
782c2d65
DB
1325 };
1326
1327 memset(&opts, 0, sizeof(opts));
c8a3ea1f 1328 memset(&new_branch_info, 0, sizeof(new_branch_info));
c1d7036b 1329 opts.overwrite_ignore = 1;
e51e3057 1330 opts.prefix = prefix;
870ebdb9 1331 opts.show_progress = -1;
782c2d65 1332
175f6e59 1333 git_config(git_checkout_config, &opts);
782c2d65 1334
9188ed89 1335 opts.track = BRANCH_TRACK_UNSPECIFIED;
782c2d65 1336
37782920 1337 argc = parse_options(argc, argv, prefix, options, checkout_usage,
f5242ebf 1338 PARSE_OPT_KEEP_DASHDASH);
859fdaba 1339
be4908f1 1340 dwim_new_local_branch = !no_dwim_new_local_branch;
870ebdb9
ECA
1341 if (opts.show_progress < 0) {
1342 if (opts.quiet)
1343 opts.show_progress = 0;
1344 else
1345 opts.show_progress = isatty(2);
1346 }
1347
b6312c27
NTND
1348 if (conflict_style) {
1349 opts.merge = 1; /* implied */
1350 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1351 }
02ac9837 1352
b6312c27
NTND
1353 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1354 die(_("-b, -B and --orphan are mutually exclusive"));
02ac9837 1355
b6312c27
NTND
1356 /*
1357 * From here on, new_branch will contain the branch to be checked out,
1358 * and new_branch_force and new_orphan_branch will tell us which one of
1359 * -b/-B/--orphan is being used.
1360 */
02ac9837
TRC
1361 if (opts.new_branch_force)
1362 opts.new_branch = opts.new_branch_force;
1363
b6312c27
NTND
1364 if (opts.new_orphan_branch)
1365 opts.new_branch = opts.new_orphan_branch;
32669671 1366
b6312c27
NTND
1367 /* --track without -b/-B/--orphan should DWIM */
1368 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
9188ed89
AR
1369 const char *argv0 = argv[0];
1370 if (!argc || !strcmp(argv0, "--"))
1a07e59c 1371 die(_("--track needs a branch name"));
e3f1da98
RS
1372 skip_prefix(argv0, "refs/", &argv0);
1373 skip_prefix(argv0, "remotes/", &argv0);
9188ed89
AR
1374 argv0 = strchr(argv0, '/');
1375 if (!argv0 || !argv0[1])
1a07e59c 1376 die(_("missing branch name; try -b"));
9188ed89 1377 opts.new_branch = argv0 + 1;
bb0ceb62
JS
1378 }
1379
859fdaba 1380 /*
09ebad6f
JN
1381 * Extract branch name from command line arguments, so
1382 * all that is left is pathspecs.
859fdaba 1383 *
09ebad6f 1384 * Handle
70c9ac2f 1385 *
09ebad6f
JN
1386 * 1) git checkout <tree> -- [<paths>]
1387 * 2) git checkout -- [<paths>]
1388 * 3) git checkout <something> [<paths>]
859fdaba 1389 *
09ebad6f
JN
1390 * including "last branch" syntax and DWIM-ery for names of
1391 * remote branches, erroring out for invalid or ambiguous cases.
859fdaba 1392 */
782c2d65 1393 if (argc) {
60af7691 1394 struct object_id rev;
09ebad6f 1395 int dwim_ok =
e51e3057 1396 !opts.patch_mode &&
09ebad6f
JN
1397 dwim_new_local_branch &&
1398 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1399 !opts.new_branch;
f8bd36a4 1400 int n = parse_branchname_arg(argc, argv, dwim_ok,
3c87aa94
ÆAB
1401 &new_branch_info, &opts, &rev,
1402 &dwim_remotes_matched);
09ebad6f
JN
1403 argv += n;
1404 argc -= n;
782c2d65
DB
1405 }
1406
782c2d65 1407 if (argc) {
480ca644
NTND
1408 parse_pathspec(&opts.pathspec, 0,
1409 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1410 prefix, argv);
301e42ed 1411
817b345a 1412 if (!opts.pathspec.nr)
e8a8a4d7 1413 die(_("invalid path specification"));
301e42ed 1414
b6312c27
NTND
1415 /*
1416 * Try to give more helpful suggestion.
1417 * new_branch && argc > 1 will be caught later.
1418 */
1419 if (opts.new_branch && argc == 1)
6c486862
JNA
1420 die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
1421 argv[0], opts.new_branch);
782c2d65 1422
32669671 1423 if (opts.force_detach)
b6312c27
NTND
1424 die(_("git checkout: --detach does not take a path argument '%s'"),
1425 argv[0]);
32669671 1426
0cf8581e 1427 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
b6312c27
NTND
1428 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1429 "checking out of the index."));
782c2d65
DB
1430 }
1431
352eadc4 1432 if (opts.new_branch) {
f285a2d7 1433 struct strbuf buf = STRBUF_INIT;
55c4a673 1434
bc1c9c0e
JH
1435 if (opts.new_branch_force)
1436 opts.branch_exists = validate_branchname(opts.new_branch, &buf);
1437 else
1438 opts.branch_exists =
1439 validate_new_branchname(opts.new_branch, &buf, 0);
352eadc4
DB
1440 strbuf_release(&buf);
1441 }
1442
886e1084 1443 UNLEAK(opts);
1c550553
ÆAB
1444 if (opts.patch_mode || opts.pathspec.nr) {
1445 int ret = checkout_paths(&opts, new_branch_info.name);
ad8d5104
ÆAB
1446 if (ret && dwim_remotes_matched > 1 &&
1447 advice_checkout_ambiguous_remote_branch_name)
1448 advise(_("'%s' matched more than one remote tracking branch.\n"
1449 "We found %d remotes with a reference that matched. So we fell back\n"
1450 "on trying to resolve the argument as a path, but failed there too!\n"
1451 "\n"
1452 "If you meant to check out a remote tracking branch on, e.g. 'origin',\n"
1453 "you can do so by fully qualifying the name with the --track option:\n"
1454 "\n"
8d7b558b
ÆAB
1455 " git checkout --track origin/<name>\n"
1456 "\n"
1457 "If you'd like to always have checkouts of an ambiguous <name> prefer\n"
1458 "one remote, e.g. the 'origin' remote, consider setting\n"
1459 "checkout.defaultRemote=origin in your config."),
ad8d5104
ÆAB
1460 argv[0],
1461 dwim_remotes_matched);
1c550553
ÆAB
1462 return ret;
1463 } else {
c8a3ea1f 1464 return checkout_branch(&opts, &new_branch_info);
1c550553 1465 }
782c2d65 1466}