Update draft release notes to 1.8.3
[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"
b9d37a54 8#include "cache-tree.h"
782c2d65
DB
9#include "unpack-trees.h"
10#include "dir.h"
11#include "run-command.h"
12#include "merge-recursive.h"
13#include "branch.h"
14#include "diff.h"
15#include "revision.h"
79a1e6b4 16#include "remote.h"
0cf8581e
JH
17#include "blob.h"
18#include "xdiff-interface.h"
19#include "ll-merge.h"
cfc5789a 20#include "resolve-undo.h"
175f6e59 21#include "submodule.h"
7bf0b017 22#include "argv-array.h"
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DB
23
24static const char * const checkout_usage[] = {
e05a1093
NTND
25 N_("git checkout [options] <branch>"),
26 N_("git checkout [options] [<branch>] -- <file>..."),
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DB
27 NULL,
28};
29
db941099 30struct checkout_opts {
e51e3057 31 int patch_mode;
db941099
JH
32 int quiet;
33 int merge;
34 int force;
32669671 35 int force_detach;
38901a48 36 int writeout_stage;
c1d7036b 37 int overwrite_ignore;
db941099
JH
38
39 const char *new_branch;
02ac9837 40 const char *new_branch_force;
9db5ebf4 41 const char *new_orphan_branch;
db941099
JH
42 int new_branch_log;
43 enum branch_track track;
175f6e59 44 struct diff_options diff_options;
e51e3057
NTND
45
46 int branch_exists;
47 const char *prefix;
48 const char **pathspec;
49 struct tree *source_tree;
db941099
JH
50};
51
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DB
52static int post_checkout_hook(struct commit *old, struct commit *new,
53 int changed)
54{
ae98a008
SB
55 return run_hook(NULL, "post-checkout",
56 sha1_to_hex(old ? old->object.sha1 : null_sha1),
57 sha1_to_hex(new ? new->object.sha1 : null_sha1),
58 changed ? "1" : "0", NULL);
2292ce47
SB
59 /* "new" can be NULL when checking out from the index before
60 a commit exists. */
ae98a008 61
782c2d65
DB
62}
63
64static int update_some(const unsigned char *sha1, const char *base, int baselen,
671f0707 65 const char *pathname, unsigned mode, int stage, void *context)
782c2d65
DB
66{
67 int len;
68 struct cache_entry *ce;
69
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DB
70 if (S_ISDIR(mode))
71 return READ_TREE_RECURSIVE;
72
73 len = baselen + strlen(pathname);
74 ce = xcalloc(1, cache_entry_size(len));
75 hashcpy(ce->sha1, sha1);
76 memcpy(ce->name, base, baselen);
77 memcpy(ce->name + baselen, pathname, len - baselen);
b60e188c
TG
78 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
79 ce->ce_namelen = len;
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DB
80 ce->ce_mode = create_ce_mode(mode);
81 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
82 return 0;
83}
84
85static int read_tree_some(struct tree *tree, const char **pathspec)
86{
f0096c06
NTND
87 struct pathspec ps;
88 init_pathspec(&ps, pathspec);
89 read_tree_recursive(tree, "", 0, 0, &ps, update_some, NULL);
90 free_pathspec(&ps);
782c2d65 91
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DB
92 /* update the index with the given tree's info
93 * for all args, expanding wildcards, and exit
94 * with any non-zero return code.
95 */
96 return 0;
97}
98
8fdcf312
JH
99static int skip_same_name(struct cache_entry *ce, int pos)
100{
101 while (++pos < active_nr &&
102 !strcmp(active_cache[pos]->name, ce->name))
103 ; /* skip */
104 return pos;
105}
106
38901a48
JH
107static int check_stage(int stage, struct cache_entry *ce, int pos)
108{
109 while (pos < active_nr &&
110 !strcmp(active_cache[pos]->name, ce->name)) {
111 if (ce_stage(active_cache[pos]) == stage)
112 return 0;
113 pos++;
114 }
9f97ab08
ÆAB
115 if (stage == 2)
116 return error(_("path '%s' does not have our version"), ce->name);
117 else
118 return error(_("path '%s' does not have their version"), ce->name);
38901a48
JH
119}
120
fbbccd0a 121static int check_stages(unsigned stages, struct cache_entry *ce, int pos)
0cf8581e 122{
fbbccd0a
JH
123 unsigned seen = 0;
124 const char *name = ce->name;
125
126 while (pos < active_nr) {
127 ce = active_cache[pos];
128 if (strcmp(name, ce->name))
129 break;
130 seen |= (1 << ce_stage(ce));
131 pos++;
132 }
133 if ((stages & seen) != stages)
134 return error(_("path '%s' does not have all necessary versions"),
135 name);
0cf8581e
JH
136 return 0;
137}
138
38901a48
JH
139static int checkout_stage(int stage, struct cache_entry *ce, int pos,
140 struct checkout *state)
141{
142 while (pos < active_nr &&
143 !strcmp(active_cache[pos]->name, ce->name)) {
144 if (ce_stage(active_cache[pos]) == stage)
145 return checkout_entry(active_cache[pos], state, NULL);
146 pos++;
147 }
9f97ab08
ÆAB
148 if (stage == 2)
149 return error(_("path '%s' does not have our version"), ce->name);
150 else
151 return error(_("path '%s' does not have their version"), ce->name);
38901a48 152}
8fdcf312 153
0cf8581e
JH
154static int checkout_merged(int pos, struct checkout *state)
155{
156 struct cache_entry *ce = active_cache[pos];
157 const char *path = ce->name;
158 mmfile_t ancestor, ours, theirs;
159 int status;
160 unsigned char sha1[20];
161 mmbuffer_t result_buf;
fbbccd0a 162 unsigned char threeway[3][20];
335c6e40 163 unsigned mode = 0;
0cf8581e 164
fbbccd0a
JH
165 memset(threeway, 0, sizeof(threeway));
166 while (pos < active_nr) {
167 int stage;
168 stage = ce_stage(ce);
169 if (!stage || strcmp(path, ce->name))
170 break;
171 hashcpy(threeway[stage - 1], ce->sha1);
172 if (stage == 2)
173 mode = create_ce_mode(ce->ce_mode);
174 pos++;
175 ce = active_cache[pos];
176 }
177 if (is_null_sha1(threeway[1]) || is_null_sha1(threeway[2]))
178 return error(_("path '%s' does not have necessary versions"), path);
0cf8581e 179
fbbccd0a
JH
180 read_mmblob(&ancestor, threeway[0]);
181 read_mmblob(&ours, threeway[1]);
182 read_mmblob(&theirs, threeway[2]);
0cf8581e 183
18b037a5
JN
184 /*
185 * NEEDSWORK: re-create conflicts from merges with
186 * merge.renormalize set, too
187 */
f0531a29 188 status = ll_merge(&result_buf, path, &ancestor, "base",
712516bc 189 &ours, "ours", &theirs, "theirs", NULL);
0cf8581e
JH
190 free(ancestor.ptr);
191 free(ours.ptr);
192 free(theirs.ptr);
193 if (status < 0 || !result_buf.ptr) {
194 free(result_buf.ptr);
e8a8a4d7 195 return error(_("path '%s': cannot merge"), path);
0cf8581e
JH
196 }
197
198 /*
199 * NEEDSWORK:
200 * There is absolutely no reason to write this as a blob object
3ea3c215 201 * and create a phony cache entry just to leak. This hack is
0cf8581e
JH
202 * primarily to get to the write_entry() machinery that massages
203 * the contents to work-tree format and writes out which only
204 * allows it for a cache entry. The code in write_entry() needs
205 * to be refactored to allow us to feed a <buffer, size, mode>
206 * instead of a cache entry. Such a refactoring would help
207 * merge_recursive as well (it also writes the merge result to the
208 * object database even when it may contain conflicts).
209 */
210 if (write_sha1_file(result_buf.ptr, result_buf.size,
211 blob_type, sha1))
e8a8a4d7 212 die(_("Unable to add merge result for '%s'"), path);
fbbccd0a 213 ce = make_cache_entry(mode, sha1, path, 2, 0);
048f2762 214 if (!ce)
e8a8a4d7 215 die(_("make_cache_entry failed for path '%s'"), path);
0cf8581e
JH
216 status = checkout_entry(ce, state, NULL);
217 return status;
218}
8fdcf312 219
b6312c27
NTND
220static int checkout_paths(const struct checkout_opts *opts,
221 const char *revision)
782c2d65
DB
222{
223 int pos;
224 struct checkout state;
225 static char *ps_matched;
226 unsigned char rev[20];
227 int flag;
228 struct commit *head;
d2b3691b 229 int errs = 0;
38901a48 230 int stage = opts->writeout_stage;
0cf8581e 231 int merge = opts->merge;
75336878 232 int newfd;
b6312c27
NTND
233 struct lock_file *lock_file;
234
235 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
236 die(_("'%s' cannot be used with updating paths"), "--track");
237
238 if (opts->new_branch_log)
239 die(_("'%s' cannot be used with updating paths"), "-l");
240
241 if (opts->force && opts->patch_mode)
242 die(_("'%s' cannot be used with updating paths"), "-f");
243
244 if (opts->force_detach)
245 die(_("'%s' cannot be used with updating paths"), "--detach");
246
247 if (opts->merge && opts->patch_mode)
248 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
249
250 if (opts->force && opts->merge)
251 die(_("'%s' cannot be used with %s"), "-f", "-m");
252
253 if (opts->new_branch)
254 die(_("Cannot update paths and switch to branch '%s' at the same time."),
255 opts->new_branch);
256
257 if (opts->patch_mode)
258 return run_add_interactive(revision, "--patch=checkout",
259 opts->pathspec);
260
261 lock_file = xcalloc(1, sizeof(struct lock_file));
75336878
DB
262
263 newfd = hold_locked_index(lock_file, 1);
e51e3057 264 if (read_cache_preload(opts->pathspec) < 0)
e8a8a4d7 265 return error(_("corrupt index file"));
75336878 266
e51e3057
NTND
267 if (opts->source_tree)
268 read_tree_some(opts->source_tree, opts->pathspec);
75336878 269
e51e3057 270 for (pos = 0; opts->pathspec[pos]; pos++)
782c2d65
DB
271 ;
272 ps_matched = xcalloc(1, pos);
273
274 for (pos = 0; pos < active_nr; pos++) {
275 struct cache_entry *ce = active_cache[pos];
e51e3057 276 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
0a1283bc 277 continue;
e51e3057 278 match_pathspec(opts->pathspec, ce->name, ce_namelen(ce), 0, ps_matched);
782c2d65
DB
279 }
280
e51e3057 281 if (report_path_error(ps_matched, opts->pathspec, opts->prefix))
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DB
282 return 1;
283
4421a823
JH
284 /* "checkout -m path" to recreate conflicted state */
285 if (opts->merge)
e51e3057 286 unmerge_cache(opts->pathspec);
4421a823 287
8fdcf312
JH
288 /* Any unmerged paths? */
289 for (pos = 0; pos < active_nr; pos++) {
290 struct cache_entry *ce = active_cache[pos];
e51e3057 291 if (match_pathspec(opts->pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
8fdcf312
JH
292 if (!ce_stage(ce))
293 continue;
db941099 294 if (opts->force) {
e8a8a4d7 295 warning(_("path '%s' is unmerged"), ce->name);
38901a48
JH
296 } else if (stage) {
297 errs |= check_stage(stage, ce, pos);
0cf8581e 298 } else if (opts->merge) {
fbbccd0a 299 errs |= check_stages((1<<2) | (1<<3), ce, pos);
db941099
JH
300 } else {
301 errs = 1;
e8a8a4d7 302 error(_("path '%s' is unmerged"), ce->name);
db941099 303 }
8fdcf312
JH
304 pos = skip_same_name(ce, pos) - 1;
305 }
306 }
307 if (errs)
308 return 1;
309
d2b3691b 310 /* Now we are committed to check them out */
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DB
311 memset(&state, 0, sizeof(state));
312 state.force = 1;
313 state.refresh_cache = 1;
314 for (pos = 0; pos < active_nr; pos++) {
315 struct cache_entry *ce = active_cache[pos];
e51e3057 316 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
0a1283bc 317 continue;
e51e3057 318 if (match_pathspec(opts->pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
8fdcf312
JH
319 if (!ce_stage(ce)) {
320 errs |= checkout_entry(ce, &state, NULL);
321 continue;
322 }
38901a48
JH
323 if (stage)
324 errs |= checkout_stage(stage, ce, pos, &state);
0cf8581e
JH
325 else if (merge)
326 errs |= checkout_merged(pos, &state);
8fdcf312 327 pos = skip_same_name(ce, pos) - 1;
782c2d65
DB
328 }
329 }
330
75336878
DB
331 if (write_cache(newfd, active_cache, active_nr) ||
332 commit_locked_index(lock_file))
e8a8a4d7 333 die(_("unable to write new index file"));
75336878 334
c6893323 335 read_ref_full("HEAD", rev, 0, &flag);
782c2d65
DB
336 head = lookup_commit_reference_gently(rev, 1);
337
d2b3691b
JH
338 errs |= post_checkout_hook(head, head, 0);
339 return errs;
782c2d65
DB
340}
341
a2b4994c
NTND
342static void show_local_changes(struct object *head,
343 const struct diff_options *opts)
782c2d65
DB
344{
345 struct rev_info rev;
346 /* I think we want full paths, even if we're in a subdirectory. */
347 init_revisions(&rev, NULL);
175f6e59 348 rev.diffopt.flags = opts->flags;
782c2d65 349 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
28452655 350 diff_setup_done(&rev.diffopt);
782c2d65
DB
351 add_pending_object(&rev, head, NULL);
352 run_diff_index(&rev, 0);
353}
354
b3c0494a 355static void describe_detached_head(const char *msg, struct commit *commit)
782c2d65 356{
f285a2d7 357 struct strbuf sb = STRBUF_INIT;
782c2d65 358 parse_commit(commit);
8b8a5374 359 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
782c2d65
DB
360 fprintf(stderr, "%s %s... %s\n", msg,
361 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
362 strbuf_release(&sb);
363}
364
a2b4994c
NTND
365static int reset_tree(struct tree *tree, const struct checkout_opts *o,
366 int worktree, int *writeout_error)
782c2d65
DB
367{
368 struct unpack_trees_options opts;
369 struct tree_desc tree_desc;
bc052d7f 370
782c2d65
DB
371 memset(&opts, 0, sizeof(opts));
372 opts.head_idx = -1;
6286a08d
JH
373 opts.update = worktree;
374 opts.skip_unmerged = !worktree;
782c2d65
DB
375 opts.reset = 1;
376 opts.merge = 1;
377 opts.fn = oneway_merge;
e9fc64c6 378 opts.verbose_update = !o->quiet && isatty(2);
34110cd4
LT
379 opts.src_index = &the_index;
380 opts.dst_index = &the_index;
782c2d65
DB
381 parse_tree(tree);
382 init_tree_desc(&tree_desc, tree->buffer, tree->size);
291d823e
JH
383 switch (unpack_trees(1, &tree_desc, &opts)) {
384 case -2:
a2b4994c 385 *writeout_error = 1;
291d823e
JH
386 /*
387 * We return 0 nevertheless, as the index is all right
388 * and more importantly we have made best efforts to
389 * update paths in the work tree, and we cannot revert
390 * them.
391 */
392 case 0:
393 return 0;
394 default:
84a5750b 395 return 128;
291d823e 396 }
782c2d65
DB
397}
398
782c2d65
DB
399struct branch_info {
400 const char *name; /* The short name used */
401 const char *path; /* The full name of a real branch */
402 struct commit *commit; /* The named commit */
403};
404
405static void setup_branch_path(struct branch_info *branch)
406{
f285a2d7 407 struct strbuf buf = STRBUF_INIT;
ae5a6c36 408
a552de75
JH
409 strbuf_branchname(&buf, branch->name);
410 if (strcmp(buf.buf, branch->name))
ae5a6c36 411 branch->name = xstrdup(buf.buf);
a552de75 412 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
782c2d65
DB
413 branch->path = strbuf_detach(&buf, NULL);
414}
415
a2b4994c
NTND
416static int merge_working_tree(const struct checkout_opts *opts,
417 struct branch_info *old,
418 struct branch_info *new,
419 int *writeout_error)
782c2d65
DB
420{
421 int ret;
422 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
423 int newfd = hold_locked_index(lock_file, 1);
b96524f8 424
53996fe5 425 if (read_cache_preload(NULL) < 0)
e8a8a4d7 426 return error(_("corrupt index file"));
782c2d65 427
cfc5789a 428 resolve_undo_clear();
782c2d65 429 if (opts->force) {
a2b4994c 430 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
782c2d65
DB
431 if (ret)
432 return ret;
433 } else {
434 struct tree_desc trees[2];
435 struct tree *tree;
436 struct unpack_trees_options topts;
bc052d7f 437
782c2d65
DB
438 memset(&topts, 0, sizeof(topts));
439 topts.head_idx = -1;
34110cd4
LT
440 topts.src_index = &the_index;
441 topts.dst_index = &the_index;
782c2d65 442
e294030f 443 setup_unpack_trees_porcelain(&topts, "checkout");
8ccba008 444
782c2d65
DB
445 refresh_cache(REFRESH_QUIET);
446
447 if (unmerged_cache()) {
e8a8a4d7 448 error(_("you need to resolve your current index first"));
04c9e11f 449 return 1;
782c2d65 450 }
04c9e11f
JH
451
452 /* 2-way merge to the new branch */
fa7b3c2f 453 topts.initial_checkout = is_cache_unborn();
04c9e11f
JH
454 topts.update = 1;
455 topts.merge = 1;
64da3ae5 456 topts.gently = opts->merge && old->commit;
e9fc64c6 457 topts.verbose_update = !opts->quiet && isatty(2);
04c9e11f 458 topts.fn = twoway_merge;
c1d7036b
NTND
459 if (opts->overwrite_ignore) {
460 topts.dir = xcalloc(1, sizeof(*topts.dir));
461 topts.dir->flags |= DIR_SHOW_IGNORED;
462 setup_standard_excludes(topts.dir);
463 }
cc580af8
JK
464 tree = parse_tree_indirect(old->commit ?
465 old->commit->object.sha1 :
dab0d410 466 EMPTY_TREE_SHA1_BIN);
04c9e11f
JH
467 init_tree_desc(&trees[0], tree->buffer, tree->size);
468 tree = parse_tree_indirect(new->commit->object.sha1);
469 init_tree_desc(&trees[1], tree->buffer, tree->size);
470
291d823e 471 ret = unpack_trees(2, trees, &topts);
49d833dc 472 if (ret == -1) {
782c2d65
DB
473 /*
474 * Unpack couldn't do a trivial merge; either
475 * give up or do a real merge, depending on
476 * whether the merge flag was used.
477 */
478 struct tree *result;
479 struct tree *work;
8a2fce18 480 struct merge_options o;
782c2d65
DB
481 if (!opts->merge)
482 return 1;
64da3ae5
JH
483
484 /*
485 * Without old->commit, the below is the same as
486 * the two-tree unpack we already tried and failed.
487 */
488 if (!old->commit)
489 return 1;
782c2d65
DB
490
491 /* Do more real merge */
492
493 /*
494 * We update the index fully, then write the
495 * tree from the index, then merge the new
496 * branch with the current tree, with the old
497 * branch as the base. Then we reset the index
498 * (but not the working tree) to the new
499 * branch, leaving the working tree as the
500 * merged version, but skipping unmerged
501 * entries in the index.
502 */
503
7ae02a30 504 add_files_to_cache(NULL, NULL, 0);
7610fa57
JN
505 /*
506 * NEEDSWORK: carrying over local changes
507 * when branches have different end-of-line
508 * normalization (or clean+smudge rules) is
509 * a pain; plumb in an option to set
510 * o.renormalize?
511 */
8a2fce18
MV
512 init_merge_options(&o);
513 o.verbosity = 0;
514 work = write_tree_from_memory(&o);
782c2d65 515
a2b4994c
NTND
516 ret = reset_tree(new->commit->tree, opts, 1,
517 writeout_error);
782c2d65
DB
518 if (ret)
519 return ret;
c4151629 520 o.ancestor = old->name;
8a2fce18
MV
521 o.branch1 = new->name;
522 o.branch2 = "local";
523 merge_trees(&o, new->commit->tree, work,
524 old->commit->tree, &result);
a2b4994c
NTND
525 ret = reset_tree(new->commit->tree, opts, 0,
526 writeout_error);
84a5750b
JH
527 if (ret)
528 return ret;
782c2d65
DB
529 }
530 }
531
532 if (write_cache(newfd, active_cache, active_nr) ||
533 commit_locked_index(lock_file))
e8a8a4d7 534 die(_("unable to write new index file"));
782c2d65 535
7fe4a728 536 if (!opts->force && !opts->quiet)
175f6e59 537 show_local_changes(&new->commit->object, &opts->diff_options);
782c2d65
DB
538
539 return 0;
540}
541
6d21bf96 542static void report_tracking(struct branch_info *new)
79a1e6b4 543{
6d21bf96 544 struct strbuf sb = STRBUF_INIT;
b56fca07 545 struct branch *branch = branch_get(new->name);
79a1e6b4 546
6d21bf96 547 if (!format_tracking_info(branch, &sb))
79a1e6b4 548 return;
6d21bf96
JH
549 fputs(sb.buf, stdout);
550 strbuf_release(&sb);
b0030db3 551}
79a1e6b4 552
a2b4994c 553static void update_refs_for_switch(const struct checkout_opts *opts,
782c2d65
DB
554 struct branch_info *old,
555 struct branch_info *new)
556{
f285a2d7 557 struct strbuf msg = STRBUF_INIT;
782c2d65
DB
558 const char *old_desc;
559 if (opts->new_branch) {
3631bf77
EM
560 if (opts->new_orphan_branch) {
561 if (opts->new_branch_log && !log_all_ref_updates) {
562 int temp;
157aaea5 563 char log_file[PATH_MAX];
3631bf77
EM
564 char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
565
566 temp = log_all_ref_updates;
567 log_all_ref_updates = 1;
157aaea5 568 if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
e8a8a4d7 569 fprintf(stderr, _("Can not do reflog for '%s'\n"),
3631bf77
EM
570 opts->new_orphan_branch);
571 log_all_ref_updates = temp;
572 return;
573 }
574 log_all_ref_updates = temp;
575 }
576 }
577 else
02ac9837
TRC
578 create_branch(old->name, opts->new_branch, new->name,
579 opts->new_branch_force ? 1 : 0,
39bd6f72
JN
580 opts->new_branch_log,
581 opts->new_branch_force ? 1 : 0,
f9a482e6 582 opts->quiet,
39bd6f72 583 opts->track);
782c2d65
DB
584 new->name = opts->new_branch;
585 setup_branch_path(new);
586 }
587
782c2d65 588 old_desc = old->name;
323e00fd 589 if (!old_desc && old->commit)
782c2d65
DB
590 old_desc = sha1_to_hex(old->commit->object.sha1);
591 strbuf_addf(&msg, "checkout: moving from %s to %s",
323e00fd 592 old_desc ? old_desc : "(invalid)", new->name);
782c2d65 593
f8bd36a4
JN
594 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
595 /* Nothing to do. */
596 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
597 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
598 REF_NODEREF, DIE_ON_ERR);
599 if (!opts->quiet) {
600 if (old->path && advice_detached_head)
2857093b 601 detach_advice(new->name);
6c80cd29 602 describe_detached_head(_("HEAD is now at"), new->commit);
f8bd36a4
JN
603 }
604 } else if (new->path) { /* Switch branches. */
782c2d65
DB
605 create_symref("HEAD", new->path, msg.buf);
606 if (!opts->quiet) {
08eaa4be 607 if (old->path && !strcmp(new->path, old->path)) {
39bd6f72
JN
608 if (opts->new_branch_force)
609 fprintf(stderr, _("Reset branch '%s'\n"),
610 new->name);
611 else
612 fprintf(stderr, _("Already on '%s'\n"),
613 new->name);
08eaa4be
ÆAB
614 } else if (opts->new_branch) {
615 if (opts->branch_exists)
616 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
617 else
618 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
619 } else {
e8a8a4d7 620 fprintf(stderr, _("Switched to branch '%s'\n"),
09a0ec58 621 new->name);
08eaa4be 622 }
782c2d65 623 }
3631bf77
EM
624 if (old->path && old->name) {
625 char log_file[PATH_MAX], ref_file[PATH_MAX];
626
627 git_snpath(log_file, sizeof(log_file), "logs/%s", old->path);
628 git_snpath(ref_file, sizeof(ref_file), "%s", old->path);
629 if (!file_exists(ref_file) && file_exists(log_file))
630 remove_path(log_file);
631 }
782c2d65
DB
632 }
633 remove_branch_state();
634 strbuf_release(&msg);
32669671
JH
635 if (!opts->quiet &&
636 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
6d21bf96 637 report_tracking(new);
782c2d65
DB
638}
639
468224e5
RS
640static int add_pending_uninteresting_ref(const char *refname,
641 const unsigned char *sha1,
642 int flags, void *cb_data)
8e2dc6ac 643{
add416a6 644 add_pending_sha1(cb_data, refname, sha1, UNINTERESTING);
5c08dc48
JK
645 return 0;
646}
8e2dc6ac
JH
647
648static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
649{
8e2dc6ac 650 parse_commit(commit);
0be240cc
JK
651 strbuf_addstr(sb, " ");
652 strbuf_addstr(sb,
653 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
654 strbuf_addch(sb, ' ');
f67d2e82 655 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
8e2dc6ac
JH
656 strbuf_addch(sb, '\n');
657}
658
659#define ORPHAN_CUTOFF 4
660static void suggest_reattach(struct commit *commit, struct rev_info *revs)
661{
662 struct commit *c, *last = NULL;
663 struct strbuf sb = STRBUF_INIT;
664 int lost = 0;
665 while ((c = get_revision(revs)) != NULL) {
666 if (lost < ORPHAN_CUTOFF)
667 describe_one_orphan(&sb, c);
668 last = c;
669 lost++;
670 }
671 if (ORPHAN_CUTOFF < lost) {
672 int more = lost - ORPHAN_CUTOFF;
673 if (more == 1)
674 describe_one_orphan(&sb, last);
675 else
f06f08b7 676 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
8e2dc6ac
JH
677 }
678
679 fprintf(stderr,
f06f08b7
ÆAB
680 Q_(
681 /* The singular version */
682 "Warning: you are leaving %d commit behind, "
683 "not connected to\n"
684 "any of your branches:\n\n"
0faf2474 685 "%s\n",
f06f08b7
ÆAB
686 /* The plural version */
687 "Warning: you are leaving %d commits behind, "
8e2dc6ac
JH
688 "not connected to\n"
689 "any of your branches:\n\n"
f807b3dc 690 "%s\n",
f06f08b7
ÆAB
691 /* Give ngettext() the count */
692 lost),
693 lost,
f807b3dc 694 sb.buf);
8e2dc6ac 695 strbuf_release(&sb);
f807b3dc
JH
696
697 if (advice_detached_head)
698 fprintf(stderr,
0faf2474 699 _(
f807b3dc
JH
700 "If you want to keep them by creating a new branch, "
701 "this may be a good time\nto do so with:\n\n"
0faf2474 702 " git branch new_branch_name %s\n\n"),
f807b3dc 703 sha1_to_hex(commit->object.sha1));
8e2dc6ac
JH
704}
705
706/*
707 * We are about to leave commit that was at the tip of a detached
708 * HEAD. If it is not reachable from any ref, this is the last chance
709 * for the user to do so without resorting to reflog.
710 */
5d886395 711static void orphaned_commit_warning(struct commit *old, struct commit *new)
8e2dc6ac 712{
8e2dc6ac 713 struct rev_info revs;
5d886395 714 struct object *object = &old->object;
10621419 715 struct object_array refs;
8e2dc6ac
JH
716
717 init_revisions(&revs, NULL);
468224e5
RS
718 setup_revisions(0, NULL, &revs, NULL);
719
720 object->flags &= ~UNINTERESTING;
721 add_pending_object(&revs, object, sha1_to_hex(object->sha1));
722
723 for_each_ref(add_pending_uninteresting_ref, &revs);
5d886395 724 add_pending_sha1(&revs, "HEAD", new->object.sha1, UNINTERESTING);
468224e5 725
10621419
RS
726 refs = revs.pending;
727 revs.leak_pending = 1;
728
8e2dc6ac 729 if (prepare_revision_walk(&revs))
6c80cd29 730 die(_("internal error in revision walk"));
5d886395
JS
731 if (!(old->object.flags & UNINTERESTING))
732 suggest_reattach(old, &revs);
8e2dc6ac 733 else
5d886395 734 describe_detached_head(_("Previous HEAD position was"), old);
5c08dc48 735
86a0a408 736 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
10621419 737 free(refs.objects);
8e2dc6ac
JH
738}
739
e51e3057
NTND
740static int switch_branches(const struct checkout_opts *opts,
741 struct branch_info *new)
782c2d65
DB
742{
743 int ret = 0;
744 struct branch_info old;
96ec7b1e 745 void *path_to_free;
782c2d65 746 unsigned char rev[20];
a2b4994c 747 int flag, writeout_error = 0;
782c2d65 748 memset(&old, 0, sizeof(old));
96ec7b1e 749 old.path = path_to_free = resolve_refdup("HEAD", rev, 0, &flag);
782c2d65 750 old.commit = lookup_commit_reference_gently(rev, 1);
96ec7b1e 751 if (!(flag & REF_ISSYMREF))
782c2d65
DB
752 old.path = NULL;
753
754 if (old.path && !prefixcmp(old.path, "refs/heads/"))
755 old.name = old.path + strlen("refs/heads/");
756
757 if (!new->name) {
758 new->name = "HEAD";
759 new->commit = old.commit;
760 if (!new->commit)
e8a8a4d7 761 die(_("You are on a branch yet to be born"));
782c2d65
DB
762 parse_commit(new->commit);
763 }
764
a2b4994c 765 ret = merge_working_tree(opts, &old, new, &writeout_error);
96ec7b1e
NTND
766 if (ret) {
767 free(path_to_free);
782c2d65 768 return ret;
96ec7b1e 769 }
782c2d65 770
77ebd56d 771 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
5d886395 772 orphaned_commit_warning(old.commit, new->commit);
77ebd56d 773
782c2d65
DB
774 update_refs_for_switch(opts, &old, new);
775
291d823e 776 ret = post_checkout_hook(old.commit, new->commit, 1);
96ec7b1e 777 free(path_to_free);
a2b4994c 778 return ret || writeout_error;
782c2d65
DB
779}
780
0cf8581e
JH
781static int git_checkout_config(const char *var, const char *value, void *cb)
782{
175f6e59
JS
783 if (!strcmp(var, "diff.ignoresubmodules")) {
784 struct checkout_opts *opts = cb;
785 handle_ignore_submodules_arg(&opts->diff_options, value);
786 return 0;
787 }
23b4c7bc
JL
788
789 if (!prefixcmp(var, "submodule."))
790 return parse_submodule_config_option(var, value);
791
175f6e59 792 return git_xmerge_config(var, value, NULL);
0cf8581e
JH
793}
794
70c9ac2f
JH
795struct tracking_name_data {
796 const char *name;
797 char *remote;
798 int unique;
799};
800
801static int check_tracking_name(const char *refname, const unsigned char *sha1,
802 int flags, void *cb_data)
803{
804 struct tracking_name_data *cb = cb_data;
805 const char *slash;
806
807 if (prefixcmp(refname, "refs/remotes/"))
808 return 0;
809 slash = strchr(refname + 13, '/');
810 if (!slash || strcmp(slash + 1, cb->name))
811 return 0;
812 if (cb->remote) {
813 cb->unique = 0;
814 return 0;
815 }
816 cb->remote = xstrdup(refname);
817 return 0;
818}
819
820static const char *unique_tracking_name(const char *name)
821{
66dbfd55
GV
822 struct tracking_name_data cb_data = { NULL, NULL, 1 };
823 cb_data.name = name;
70c9ac2f
JH
824 for_each_ref(check_tracking_name, &cb_data);
825 if (cb_data.unique)
826 return cb_data.remote;
827 free(cb_data.remote);
828 return NULL;
829}
4f353658 830
09ebad6f
JN
831static int parse_branchname_arg(int argc, const char **argv,
832 int dwim_new_local_branch_ok,
833 struct branch_info *new,
834 struct tree **source_tree,
835 unsigned char rev[20],
836 const char **new_branch)
837{
838 int argcount = 0;
839 unsigned char branch_rev[20];
840 const char *arg;
841 int has_dash_dash;
842
843 /*
844 * case 1: git checkout <ref> -- [<paths>]
845 *
846 * <ref> must be a valid tree, everything after the '--' must be
847 * a path.
848 *
849 * case 2: git checkout -- [<paths>]
850 *
851 * everything after the '--' must be paths.
852 *
853 * case 3: git checkout <something> [<paths>]
854 *
855 * With no paths, if <something> is a commit, that is to
856 * switch to the branch or detach HEAD at it. As a special case,
857 * if <something> is A...B (missing A or B means HEAD but you can
858 * omit at most one side), and if there is a unique merge base
859 * between A and B, A...B names that merge base.
860 *
861 * With no paths, if <something> is _not_ a commit, no -t nor -b
862 * was given, and there is a tracking branch whose name is
863 * <something> in one and only one remote, then this is a short-hand
c0791f36 864 * to fork local <something> from that remote-tracking branch.
09ebad6f
JN
865 *
866 * Otherwise <something> shall not be ambiguous.
867 * - If it's *only* a reference, treat it like case (1).
868 * - If it's only a path, treat it like case (2).
869 * - else: fail.
870 *
871 */
872 if (!argc)
873 return 0;
874
875 if (!strcmp(argv[0], "--")) /* case (2) */
876 return 1;
877
878 arg = argv[0];
879 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
880
881 if (!strcmp(arg, "-"))
882 arg = "@{-1}";
883
884 if (get_sha1_mb(arg, rev)) {
885 if (has_dash_dash) /* case (1) */
6c80cd29 886 die(_("invalid reference: %s"), arg);
09ebad6f
JN
887 if (dwim_new_local_branch_ok &&
888 !check_filename(NULL, arg) &&
889 argc == 1) {
890 const char *remote = unique_tracking_name(arg);
891 if (!remote || get_sha1(remote, rev))
892 return argcount;
893 *new_branch = arg;
894 arg = remote;
895 /* DWIMmed to create local branch */
896 } else {
897 return argcount;
898 }
899 }
900
901 /* we can't end up being in (2) anymore, eat the argument */
902 argcount++;
903 argv++;
904 argc--;
905
906 new->name = arg;
907 setup_branch_path(new);
908
8d9c5010 909 if (!check_refname_format(new->path, 0) &&
c6893323 910 !read_ref(new->path, branch_rev))
09ebad6f
JN
911 hashcpy(rev, branch_rev);
912 else
913 new->path = NULL; /* not an existing branch */
914
915 new->commit = lookup_commit_reference_gently(rev, 1);
916 if (!new->commit) {
917 /* not a commit */
918 *source_tree = parse_tree_indirect(rev);
919 } else {
920 parse_commit(new->commit);
921 *source_tree = new->commit->tree;
922 }
923
924 if (!*source_tree) /* case (1): want a tree */
6c80cd29 925 die(_("reference is not a tree: %s"), arg);
09ebad6f
JN
926 if (!has_dash_dash) {/* case (3 -> 1) */
927 /*
928 * Do not complain the most common case
929 * git checkout branch
930 * even if there happen to be a file called 'branch';
931 * it would be extremely annoying.
932 */
933 if (argc)
934 verify_non_filename(NULL, arg);
935 } else {
936 argcount++;
937 argv++;
938 argc--;
939 }
940
941 return argcount;
942}
943
a2b4994c 944static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
abe19980
JH
945{
946 int status;
947 struct strbuf branch_ref = STRBUF_INIT;
948
8ced1aa0
CW
949 if (!opts->new_branch)
950 die(_("You are on a branch yet to be born"));
abe19980
JH
951 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
952 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
953 strbuf_release(&branch_ref);
afa8c07a
JK
954 if (!opts->quiet)
955 fprintf(stderr, _("Switched to a new branch '%s'\n"),
956 opts->new_branch);
abe19980
JH
957 return status;
958}
959
b6312c27
NTND
960static int checkout_branch(struct checkout_opts *opts,
961 struct branch_info *new)
962{
963 if (opts->pathspec)
964 die(_("paths cannot be used with switching branches"));
965
966 if (opts->patch_mode)
967 die(_("'%s' cannot be used with switching branches"),
968 "--patch");
969
970 if (opts->writeout_stage)
971 die(_("'%s' cannot be used with switching branches"),
972 "--ours/--theirs");
973
974 if (opts->force && opts->merge)
975 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
976
977 if (opts->force_detach && opts->new_branch)
978 die(_("'%s' cannot be used with '%s'"),
979 "--detach", "-b/-B/--orphan");
980
981 if (opts->new_orphan_branch) {
982 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
983 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
984 } else if (opts->force_detach) {
985 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
986 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
987 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
988 opts->track = git_branch_track;
989
990 if (new->name && !new->commit)
991 die(_("Cannot switch branch to a non-commit '%s'"),
992 new->name);
993
994 if (!new->commit && opts->new_branch) {
995 unsigned char rev[20];
996 int flag;
997
998 if (!read_ref_full("HEAD", rev, 0, &flag) &&
999 (flag & REF_ISSYMREF) && is_null_sha1(rev))
1000 return switch_unborn_to_new_branch(opts);
1001 }
1002 return switch_branches(opts, new);
1003}
1004
782c2d65
DB
1005int cmd_checkout(int argc, const char **argv, const char *prefix)
1006{
1007 struct checkout_opts opts;
782c2d65 1008 struct branch_info new;
eac5a401 1009 char *conflict_style = NULL;
46148dd7 1010 int dwim_new_local_branch = 1;
782c2d65 1011 struct option options[] = {
e05a1093
NTND
1012 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1013 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1014 N_("create and checkout a new branch")),
1015 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1016 N_("create/reset and checkout a branch")),
1017 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1018 OPT_BOOLEAN(0, "detach", &opts.force_detach, N_("detach the HEAD at named commit")),
1019 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
9ed36cfa 1020 BRANCH_TRACK_EXPLICIT),
e05a1093
NTND
1021 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new branch"), N_("new unparented branch")),
1022 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
38901a48 1023 2),
e05a1093 1024 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
38901a48 1025 3),
e05a1093
NTND
1026 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1027 OPT_BOOLEAN('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1028 OPT_BOOLEAN(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1029 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1030 N_("conflict style (merge or diff3)")),
b58f3a64 1031 OPT_BOOLEAN('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
46148dd7 1032 { OPTION_BOOLEAN, 0, "guess", &dwim_new_local_branch, NULL,
e05a1093 1033 N_("second guess 'git checkout no-such-branch'"),
46148dd7 1034 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
b249b552 1035 OPT_END(),
782c2d65
DB
1036 };
1037
1038 memset(&opts, 0, sizeof(opts));
1039 memset(&new, 0, sizeof(new));
c1d7036b 1040 opts.overwrite_ignore = 1;
e51e3057 1041 opts.prefix = prefix;
782c2d65 1042
23b4c7bc 1043 gitmodules_config();
175f6e59 1044 git_config(git_checkout_config, &opts);
782c2d65 1045
9188ed89 1046 opts.track = BRANCH_TRACK_UNSPECIFIED;
782c2d65 1047
37782920 1048 argc = parse_options(argc, argv, prefix, options, checkout_usage,
f5242ebf 1049 PARSE_OPT_KEEP_DASHDASH);
859fdaba 1050
b6312c27
NTND
1051 if (conflict_style) {
1052 opts.merge = 1; /* implied */
1053 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1054 }
02ac9837 1055
b6312c27
NTND
1056 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1057 die(_("-b, -B and --orphan are mutually exclusive"));
02ac9837 1058
b6312c27
NTND
1059 /*
1060 * From here on, new_branch will contain the branch to be checked out,
1061 * and new_branch_force and new_orphan_branch will tell us which one of
1062 * -b/-B/--orphan is being used.
1063 */
02ac9837
TRC
1064 if (opts.new_branch_force)
1065 opts.new_branch = opts.new_branch_force;
1066
b6312c27
NTND
1067 if (opts.new_orphan_branch)
1068 opts.new_branch = opts.new_orphan_branch;
32669671 1069
b6312c27
NTND
1070 /* --track without -b/-B/--orphan should DWIM */
1071 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
9188ed89
AR
1072 const char *argv0 = argv[0];
1073 if (!argc || !strcmp(argv0, "--"))
e8a8a4d7 1074 die (_("--track needs a branch name"));
9188ed89
AR
1075 if (!prefixcmp(argv0, "refs/"))
1076 argv0 += 5;
1077 if (!prefixcmp(argv0, "remotes/"))
1078 argv0 += 8;
1079 argv0 = strchr(argv0, '/');
1080 if (!argv0 || !argv0[1])
e8a8a4d7 1081 die (_("Missing branch name; try -b"));
9188ed89 1082 opts.new_branch = argv0 + 1;
bb0ceb62
JS
1083 }
1084
859fdaba 1085 /*
09ebad6f
JN
1086 * Extract branch name from command line arguments, so
1087 * all that is left is pathspecs.
859fdaba 1088 *
09ebad6f 1089 * Handle
70c9ac2f 1090 *
09ebad6f
JN
1091 * 1) git checkout <tree> -- [<paths>]
1092 * 2) git checkout -- [<paths>]
1093 * 3) git checkout <something> [<paths>]
859fdaba 1094 *
09ebad6f
JN
1095 * including "last branch" syntax and DWIM-ery for names of
1096 * remote branches, erroring out for invalid or ambiguous cases.
859fdaba 1097 */
782c2d65 1098 if (argc) {
e51e3057 1099 unsigned char rev[20];
09ebad6f 1100 int dwim_ok =
e51e3057 1101 !opts.patch_mode &&
09ebad6f
JN
1102 dwim_new_local_branch &&
1103 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1104 !opts.new_branch;
f8bd36a4 1105 int n = parse_branchname_arg(argc, argv, dwim_ok,
e51e3057
NTND
1106 &new, &opts.source_tree,
1107 rev, &opts.new_branch);
09ebad6f
JN
1108 argv += n;
1109 argc -= n;
782c2d65
DB
1110 }
1111
782c2d65 1112 if (argc) {
e51e3057 1113 opts.pathspec = get_pathspec(prefix, argv);
301e42ed 1114
e51e3057 1115 if (!opts.pathspec)
e8a8a4d7 1116 die(_("invalid path specification"));
301e42ed 1117
b6312c27
NTND
1118 /*
1119 * Try to give more helpful suggestion.
1120 * new_branch && argc > 1 will be caught later.
1121 */
1122 if (opts.new_branch && argc == 1)
1123 die(_("Cannot update paths and switch to branch '%s' at the same time.\n"
1124 "Did you intend to checkout '%s' which can not be resolved as commit?"),
1125 opts.new_branch, argv[0]);
782c2d65 1126
32669671 1127 if (opts.force_detach)
b6312c27
NTND
1128 die(_("git checkout: --detach does not take a path argument '%s'"),
1129 argv[0]);
32669671 1130
0cf8581e 1131 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
b6312c27
NTND
1132 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1133 "checking out of the index."));
782c2d65
DB
1134 }
1135
352eadc4 1136 if (opts.new_branch) {
f285a2d7 1137 struct strbuf buf = STRBUF_INIT;
55c4a673 1138
b6312c27
NTND
1139 opts.branch_exists =
1140 validate_new_branchname(opts.new_branch, &buf,
1141 !!opts.new_branch_force,
1142 !!opts.new_branch_force);
55c4a673 1143
352eadc4
DB
1144 strbuf_release(&buf);
1145 }
1146
b6312c27
NTND
1147 if (opts.patch_mode || opts.pathspec)
1148 return checkout_paths(&opts, new.name);
1149 else
1150 return checkout_branch(&opts, &new);
782c2d65 1151}