Merge branch 'gv/portable'
[git/git.git] / builtin / checkout.c
1 #include "cache.h"
2 #include "builtin.h"
3 #include "parse-options.h"
4 #include "refs.h"
5 #include "commit.h"
6 #include "tree.h"
7 #include "tree-walk.h"
8 #include "cache-tree.h"
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"
16 #include "remote.h"
17 #include "blob.h"
18 #include "xdiff-interface.h"
19 #include "ll-merge.h"
20 #include "resolve-undo.h"
21
22 static const char * const checkout_usage[] = {
23 "git checkout [options] <branch>",
24 "git checkout [options] [<branch>] -- <file>...",
25 NULL,
26 };
27
28 struct checkout_opts {
29 int quiet;
30 int merge;
31 int force;
32 int writeout_stage;
33 int writeout_error;
34
35 const char *new_branch;
36 const char *new_orphan_branch;
37 int new_branch_log;
38 enum branch_track track;
39 };
40
41 static int post_checkout_hook(struct commit *old, struct commit *new,
42 int changed)
43 {
44 return run_hook(NULL, "post-checkout",
45 sha1_to_hex(old ? old->object.sha1 : null_sha1),
46 sha1_to_hex(new ? new->object.sha1 : null_sha1),
47 changed ? "1" : "0", NULL);
48 /* "new" can be NULL when checking out from the index before
49 a commit exists. */
50
51 }
52
53 static int update_some(const unsigned char *sha1, const char *base, int baselen,
54 const char *pathname, unsigned mode, int stage, void *context)
55 {
56 int len;
57 struct cache_entry *ce;
58
59 if (S_ISDIR(mode))
60 return READ_TREE_RECURSIVE;
61
62 len = baselen + strlen(pathname);
63 ce = xcalloc(1, cache_entry_size(len));
64 hashcpy(ce->sha1, sha1);
65 memcpy(ce->name, base, baselen);
66 memcpy(ce->name + baselen, pathname, len - baselen);
67 ce->ce_flags = create_ce_flags(len, 0);
68 ce->ce_mode = create_ce_mode(mode);
69 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
70 return 0;
71 }
72
73 static int read_tree_some(struct tree *tree, const char **pathspec)
74 {
75 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
76
77 /* update the index with the given tree's info
78 * for all args, expanding wildcards, and exit
79 * with any non-zero return code.
80 */
81 return 0;
82 }
83
84 static int skip_same_name(struct cache_entry *ce, int pos)
85 {
86 while (++pos < active_nr &&
87 !strcmp(active_cache[pos]->name, ce->name))
88 ; /* skip */
89 return pos;
90 }
91
92 static int check_stage(int stage, struct cache_entry *ce, int pos)
93 {
94 while (pos < active_nr &&
95 !strcmp(active_cache[pos]->name, ce->name)) {
96 if (ce_stage(active_cache[pos]) == stage)
97 return 0;
98 pos++;
99 }
100 return error("path '%s' does not have %s version",
101 ce->name,
102 (stage == 2) ? "our" : "their");
103 }
104
105 static int check_all_stages(struct cache_entry *ce, int pos)
106 {
107 if (ce_stage(ce) != 1 ||
108 active_nr <= pos + 2 ||
109 strcmp(active_cache[pos+1]->name, ce->name) ||
110 ce_stage(active_cache[pos+1]) != 2 ||
111 strcmp(active_cache[pos+2]->name, ce->name) ||
112 ce_stage(active_cache[pos+2]) != 3)
113 return error("path '%s' does not have all three versions",
114 ce->name);
115 return 0;
116 }
117
118 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
119 struct checkout *state)
120 {
121 while (pos < active_nr &&
122 !strcmp(active_cache[pos]->name, ce->name)) {
123 if (ce_stage(active_cache[pos]) == stage)
124 return checkout_entry(active_cache[pos], state, NULL);
125 pos++;
126 }
127 return error("path '%s' does not have %s version",
128 ce->name,
129 (stage == 2) ? "our" : "their");
130 }
131
132 static int checkout_merged(int pos, struct checkout *state)
133 {
134 struct cache_entry *ce = active_cache[pos];
135 const char *path = ce->name;
136 mmfile_t ancestor, ours, theirs;
137 int status;
138 unsigned char sha1[20];
139 mmbuffer_t result_buf;
140
141 if (ce_stage(ce) != 1 ||
142 active_nr <= pos + 2 ||
143 strcmp(active_cache[pos+1]->name, path) ||
144 ce_stage(active_cache[pos+1]) != 2 ||
145 strcmp(active_cache[pos+2]->name, path) ||
146 ce_stage(active_cache[pos+2]) != 3)
147 return error("path '%s' does not have all 3 versions", path);
148
149 read_mmblob(&ancestor, active_cache[pos]->sha1);
150 read_mmblob(&ours, active_cache[pos+1]->sha1);
151 read_mmblob(&theirs, active_cache[pos+2]->sha1);
152
153 status = ll_merge(&result_buf, path, &ancestor, "base",
154 &ours, "ours", &theirs, "theirs", 0);
155 free(ancestor.ptr);
156 free(ours.ptr);
157 free(theirs.ptr);
158 if (status < 0 || !result_buf.ptr) {
159 free(result_buf.ptr);
160 return error("path '%s': cannot merge", path);
161 }
162
163 /*
164 * NEEDSWORK:
165 * There is absolutely no reason to write this as a blob object
166 * and create a phony cache entry just to leak. This hack is
167 * primarily to get to the write_entry() machinery that massages
168 * the contents to work-tree format and writes out which only
169 * allows it for a cache entry. The code in write_entry() needs
170 * to be refactored to allow us to feed a <buffer, size, mode>
171 * instead of a cache entry. Such a refactoring would help
172 * merge_recursive as well (it also writes the merge result to the
173 * object database even when it may contain conflicts).
174 */
175 if (write_sha1_file(result_buf.ptr, result_buf.size,
176 blob_type, sha1))
177 die("Unable to add merge result for '%s'", path);
178 ce = make_cache_entry(create_ce_mode(active_cache[pos+1]->ce_mode),
179 sha1,
180 path, 2, 0);
181 if (!ce)
182 die("make_cache_entry failed for path '%s'", path);
183 status = checkout_entry(ce, state, NULL);
184 return status;
185 }
186
187 static int checkout_paths(struct tree *source_tree, const char **pathspec,
188 struct checkout_opts *opts)
189 {
190 int pos;
191 struct checkout state;
192 static char *ps_matched;
193 unsigned char rev[20];
194 int flag;
195 struct commit *head;
196 int errs = 0;
197 int stage = opts->writeout_stage;
198 int merge = opts->merge;
199 int newfd;
200 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
201
202 newfd = hold_locked_index(lock_file, 1);
203 if (read_cache_preload(pathspec) < 0)
204 return error("corrupt index file");
205
206 if (source_tree)
207 read_tree_some(source_tree, pathspec);
208
209 for (pos = 0; pathspec[pos]; pos++)
210 ;
211 ps_matched = xcalloc(1, pos);
212
213 for (pos = 0; pos < active_nr; pos++) {
214 struct cache_entry *ce = active_cache[pos];
215 match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, ps_matched);
216 }
217
218 if (report_path_error(ps_matched, pathspec, 0))
219 return 1;
220
221 /* "checkout -m path" to recreate conflicted state */
222 if (opts->merge)
223 unmerge_cache(pathspec);
224
225 /* Any unmerged paths? */
226 for (pos = 0; pos < active_nr; pos++) {
227 struct cache_entry *ce = active_cache[pos];
228 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
229 if (!ce_stage(ce))
230 continue;
231 if (opts->force) {
232 warning("path '%s' is unmerged", ce->name);
233 } else if (stage) {
234 errs |= check_stage(stage, ce, pos);
235 } else if (opts->merge) {
236 errs |= check_all_stages(ce, pos);
237 } else {
238 errs = 1;
239 error("path '%s' is unmerged", ce->name);
240 }
241 pos = skip_same_name(ce, pos) - 1;
242 }
243 }
244 if (errs)
245 return 1;
246
247 /* Now we are committed to check them out */
248 memset(&state, 0, sizeof(state));
249 state.force = 1;
250 state.refresh_cache = 1;
251 for (pos = 0; pos < active_nr; pos++) {
252 struct cache_entry *ce = active_cache[pos];
253 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
254 if (!ce_stage(ce)) {
255 errs |= checkout_entry(ce, &state, NULL);
256 continue;
257 }
258 if (stage)
259 errs |= checkout_stage(stage, ce, pos, &state);
260 else if (merge)
261 errs |= checkout_merged(pos, &state);
262 pos = skip_same_name(ce, pos) - 1;
263 }
264 }
265
266 if (write_cache(newfd, active_cache, active_nr) ||
267 commit_locked_index(lock_file))
268 die("unable to write new index file");
269
270 resolve_ref("HEAD", rev, 0, &flag);
271 head = lookup_commit_reference_gently(rev, 1);
272
273 errs |= post_checkout_hook(head, head, 0);
274 return errs;
275 }
276
277 static void show_local_changes(struct object *head)
278 {
279 struct rev_info rev;
280 /* I think we want full paths, even if we're in a subdirectory. */
281 init_revisions(&rev, NULL);
282 rev.abbrev = 0;
283 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
284 if (diff_setup_done(&rev.diffopt) < 0)
285 die("diff_setup_done failed");
286 add_pending_object(&rev, head, NULL);
287 run_diff_index(&rev, 0);
288 }
289
290 static void describe_detached_head(char *msg, struct commit *commit)
291 {
292 struct strbuf sb = STRBUF_INIT;
293 struct pretty_print_context ctx = {0};
294 parse_commit(commit);
295 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, &ctx);
296 fprintf(stderr, "%s %s... %s\n", msg,
297 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
298 strbuf_release(&sb);
299 }
300
301 static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
302 {
303 struct unpack_trees_options opts;
304 struct tree_desc tree_desc;
305
306 memset(&opts, 0, sizeof(opts));
307 opts.head_idx = -1;
308 opts.update = worktree;
309 opts.skip_unmerged = !worktree;
310 opts.reset = 1;
311 opts.merge = 1;
312 opts.fn = oneway_merge;
313 opts.verbose_update = !o->quiet;
314 opts.src_index = &the_index;
315 opts.dst_index = &the_index;
316 parse_tree(tree);
317 init_tree_desc(&tree_desc, tree->buffer, tree->size);
318 switch (unpack_trees(1, &tree_desc, &opts)) {
319 case -2:
320 o->writeout_error = 1;
321 /*
322 * We return 0 nevertheless, as the index is all right
323 * and more importantly we have made best efforts to
324 * update paths in the work tree, and we cannot revert
325 * them.
326 */
327 case 0:
328 return 0;
329 default:
330 return 128;
331 }
332 }
333
334 struct branch_info {
335 const char *name; /* The short name used */
336 const char *path; /* The full name of a real branch */
337 struct commit *commit; /* The named commit */
338 };
339
340 static void setup_branch_path(struct branch_info *branch)
341 {
342 struct strbuf buf = STRBUF_INIT;
343
344 strbuf_branchname(&buf, branch->name);
345 if (strcmp(buf.buf, branch->name))
346 branch->name = xstrdup(buf.buf);
347 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
348 branch->path = strbuf_detach(&buf, NULL);
349 }
350
351 static int merge_working_tree(struct checkout_opts *opts,
352 struct branch_info *old, struct branch_info *new)
353 {
354 int ret;
355 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
356 int newfd = hold_locked_index(lock_file, 1);
357
358 if (read_cache_preload(NULL) < 0)
359 return error("corrupt index file");
360
361 resolve_undo_clear();
362 if (opts->force) {
363 ret = reset_tree(new->commit->tree, opts, 1);
364 if (ret)
365 return ret;
366 } else {
367 struct tree_desc trees[2];
368 struct tree *tree;
369 struct unpack_trees_options topts;
370
371 memset(&topts, 0, sizeof(topts));
372 topts.head_idx = -1;
373 topts.src_index = &the_index;
374 topts.dst_index = &the_index;
375
376 topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
377
378 refresh_cache(REFRESH_QUIET);
379
380 if (unmerged_cache()) {
381 error("you need to resolve your current index first");
382 return 1;
383 }
384
385 /* 2-way merge to the new branch */
386 topts.initial_checkout = is_cache_unborn();
387 topts.update = 1;
388 topts.merge = 1;
389 topts.gently = opts->merge && old->commit;
390 topts.verbose_update = !opts->quiet;
391 topts.fn = twoway_merge;
392 topts.dir = xcalloc(1, sizeof(*topts.dir));
393 topts.dir->flags |= DIR_SHOW_IGNORED;
394 topts.dir->exclude_per_dir = ".gitignore";
395 tree = parse_tree_indirect(old->commit ?
396 old->commit->object.sha1 :
397 (unsigned char *)EMPTY_TREE_SHA1_BIN);
398 init_tree_desc(&trees[0], tree->buffer, tree->size);
399 tree = parse_tree_indirect(new->commit->object.sha1);
400 init_tree_desc(&trees[1], tree->buffer, tree->size);
401
402 ret = unpack_trees(2, trees, &topts);
403 if (ret == -1) {
404 /*
405 * Unpack couldn't do a trivial merge; either
406 * give up or do a real merge, depending on
407 * whether the merge flag was used.
408 */
409 struct tree *result;
410 struct tree *work;
411 struct merge_options o;
412 if (!opts->merge)
413 return 1;
414
415 /*
416 * Without old->commit, the below is the same as
417 * the two-tree unpack we already tried and failed.
418 */
419 if (!old->commit)
420 return 1;
421
422 /* Do more real merge */
423
424 /*
425 * We update the index fully, then write the
426 * tree from the index, then merge the new
427 * branch with the current tree, with the old
428 * branch as the base. Then we reset the index
429 * (but not the working tree) to the new
430 * branch, leaving the working tree as the
431 * merged version, but skipping unmerged
432 * entries in the index.
433 */
434
435 add_files_to_cache(NULL, NULL, 0);
436 init_merge_options(&o);
437 o.verbosity = 0;
438 work = write_tree_from_memory(&o);
439
440 ret = reset_tree(new->commit->tree, opts, 1);
441 if (ret)
442 return ret;
443 o.ancestor = old->name;
444 o.branch1 = new->name;
445 o.branch2 = "local";
446 merge_trees(&o, new->commit->tree, work,
447 old->commit->tree, &result);
448 ret = reset_tree(new->commit->tree, opts, 0);
449 if (ret)
450 return ret;
451 }
452 }
453
454 if (write_cache(newfd, active_cache, active_nr) ||
455 commit_locked_index(lock_file))
456 die("unable to write new index file");
457
458 if (!opts->force && !opts->quiet)
459 show_local_changes(&new->commit->object);
460
461 return 0;
462 }
463
464 static void report_tracking(struct branch_info *new)
465 {
466 struct strbuf sb = STRBUF_INIT;
467 struct branch *branch = branch_get(new->name);
468
469 if (!format_tracking_info(branch, &sb))
470 return;
471 fputs(sb.buf, stdout);
472 strbuf_release(&sb);
473 }
474
475 static void detach_advice(const char *old_path, const char *new_name)
476 {
477 const char fmt[] =
478 "Note: checking out '%s'.\n\n"
479 "You are in 'detached HEAD' state. You can look around, make experimental\n"
480 "changes and commit them, and you can discard any commits you make in this\n"
481 "state without impacting any branches by performing another checkout.\n\n"
482 "If you want to create a new branch to retain commits you create, you may\n"
483 "do so (now or later) by using -b with the checkout command again. Example:\n\n"
484 " git checkout -b new_branch_name\n\n";
485
486 fprintf(stderr, fmt, new_name);
487 }
488
489 static void update_refs_for_switch(struct checkout_opts *opts,
490 struct branch_info *old,
491 struct branch_info *new)
492 {
493 struct strbuf msg = STRBUF_INIT;
494 const char *old_desc;
495 if (opts->new_branch) {
496 if (opts->new_orphan_branch) {
497 if (opts->new_branch_log && !log_all_ref_updates) {
498 int temp;
499 char log_file[PATH_MAX];
500 char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
501
502 temp = log_all_ref_updates;
503 log_all_ref_updates = 1;
504 if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
505 fprintf(stderr, "Can not do reflog for '%s'\n",
506 opts->new_orphan_branch);
507 log_all_ref_updates = temp;
508 return;
509 }
510 log_all_ref_updates = temp;
511 }
512 }
513 else
514 create_branch(old->name, opts->new_branch, new->name, 0,
515 opts->new_branch_log, opts->track);
516 new->name = opts->new_branch;
517 setup_branch_path(new);
518 }
519
520 old_desc = old->name;
521 if (!old_desc && old->commit)
522 old_desc = sha1_to_hex(old->commit->object.sha1);
523 strbuf_addf(&msg, "checkout: moving from %s to %s",
524 old_desc ? old_desc : "(invalid)", new->name);
525
526 if (new->path) {
527 create_symref("HEAD", new->path, msg.buf);
528 if (!opts->quiet) {
529 if (old->path && !strcmp(new->path, old->path))
530 fprintf(stderr, "Already on '%s'\n",
531 new->name);
532 else
533 fprintf(stderr, "Switched to%s branch '%s'\n",
534 opts->new_branch ? " a new" : "",
535 new->name);
536 }
537 if (old->path && old->name) {
538 char log_file[PATH_MAX], ref_file[PATH_MAX];
539
540 git_snpath(log_file, sizeof(log_file), "logs/%s", old->path);
541 git_snpath(ref_file, sizeof(ref_file), "%s", old->path);
542 if (!file_exists(ref_file) && file_exists(log_file))
543 remove_path(log_file);
544 }
545 } else if (strcmp(new->name, "HEAD")) {
546 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
547 REF_NODEREF, DIE_ON_ERR);
548 if (!opts->quiet) {
549 if (old->path && advice_detached_head)
550 detach_advice(old->path, new->name);
551 describe_detached_head("HEAD is now at", new->commit);
552 }
553 }
554 remove_branch_state();
555 strbuf_release(&msg);
556 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
557 report_tracking(new);
558 }
559
560 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
561 {
562 int ret = 0;
563 struct branch_info old;
564 unsigned char rev[20];
565 int flag;
566 memset(&old, 0, sizeof(old));
567 old.path = resolve_ref("HEAD", rev, 0, &flag);
568 old.commit = lookup_commit_reference_gently(rev, 1);
569 if (!(flag & REF_ISSYMREF))
570 old.path = NULL;
571
572 if (old.path && !prefixcmp(old.path, "refs/heads/"))
573 old.name = old.path + strlen("refs/heads/");
574
575 if (!new->name) {
576 new->name = "HEAD";
577 new->commit = old.commit;
578 if (!new->commit)
579 die("You are on a branch yet to be born");
580 parse_commit(new->commit);
581 }
582
583 ret = merge_working_tree(opts, &old, new);
584 if (ret)
585 return ret;
586
587 /*
588 * If we were on a detached HEAD, but have now moved to
589 * a new commit, we want to mention the old commit once more
590 * to remind the user that it might be lost.
591 */
592 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
593 describe_detached_head("Previous HEAD position was", old.commit);
594
595 update_refs_for_switch(opts, &old, new);
596
597 ret = post_checkout_hook(old.commit, new->commit, 1);
598 return ret || opts->writeout_error;
599 }
600
601 static int git_checkout_config(const char *var, const char *value, void *cb)
602 {
603 return git_xmerge_config(var, value, cb);
604 }
605
606 static int interactive_checkout(const char *revision, const char **pathspec,
607 struct checkout_opts *opts)
608 {
609 return run_add_interactive(revision, "--patch=checkout", pathspec);
610 }
611
612 struct tracking_name_data {
613 const char *name;
614 char *remote;
615 int unique;
616 };
617
618 static int check_tracking_name(const char *refname, const unsigned char *sha1,
619 int flags, void *cb_data)
620 {
621 struct tracking_name_data *cb = cb_data;
622 const char *slash;
623
624 if (prefixcmp(refname, "refs/remotes/"))
625 return 0;
626 slash = strchr(refname + 13, '/');
627 if (!slash || strcmp(slash + 1, cb->name))
628 return 0;
629 if (cb->remote) {
630 cb->unique = 0;
631 return 0;
632 }
633 cb->remote = xstrdup(refname);
634 return 0;
635 }
636
637 static const char *unique_tracking_name(const char *name)
638 {
639 struct tracking_name_data cb_data = { NULL, NULL, 1 };
640 cb_data.name = name;
641 for_each_ref(check_tracking_name, &cb_data);
642 if (cb_data.unique)
643 return cb_data.remote;
644 free(cb_data.remote);
645 return NULL;
646 }
647
648 int cmd_checkout(int argc, const char **argv, const char *prefix)
649 {
650 struct checkout_opts opts;
651 unsigned char rev[20];
652 const char *arg;
653 struct branch_info new;
654 struct tree *source_tree = NULL;
655 char *conflict_style = NULL;
656 int patch_mode = 0;
657 int dwim_new_local_branch = 1;
658 struct option options[] = {
659 OPT__QUIET(&opts.quiet),
660 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
661 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
662 OPT_SET_INT('t', "track", &opts.track, "track",
663 BRANCH_TRACK_EXPLICIT),
664 OPT_STRING(0, "orphan", &opts.new_orphan_branch, "new branch", "new unparented branch"),
665 OPT_SET_INT('2', "ours", &opts.writeout_stage, "stage",
666 2),
667 OPT_SET_INT('3', "theirs", &opts.writeout_stage, "stage",
668 3),
669 OPT_BOOLEAN('f', "force", &opts.force, "force"),
670 OPT_BOOLEAN('m', "merge", &opts.merge, "merge"),
671 OPT_STRING(0, "conflict", &conflict_style, "style",
672 "conflict style (merge or diff3)"),
673 OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
674 { OPTION_BOOLEAN, 0, "guess", &dwim_new_local_branch, NULL,
675 "second guess 'git checkout no-such-branch'",
676 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
677 OPT_END(),
678 };
679 int has_dash_dash;
680
681 memset(&opts, 0, sizeof(opts));
682 memset(&new, 0, sizeof(new));
683
684 git_config(git_checkout_config, NULL);
685
686 opts.track = BRANCH_TRACK_UNSPECIFIED;
687
688 argc = parse_options(argc, argv, prefix, options, checkout_usage,
689 PARSE_OPT_KEEP_DASHDASH);
690
691 if (patch_mode && (opts.track > 0 || opts.new_branch
692 || opts.new_branch_log || opts.merge || opts.force))
693 die ("--patch is incompatible with all other options");
694
695 /* --track without -b should DWIM */
696 if (0 < opts.track && !opts.new_branch) {
697 const char *argv0 = argv[0];
698 if (!argc || !strcmp(argv0, "--"))
699 die ("--track needs a branch name");
700 if (!prefixcmp(argv0, "refs/"))
701 argv0 += 5;
702 if (!prefixcmp(argv0, "remotes/"))
703 argv0 += 8;
704 argv0 = strchr(argv0, '/');
705 if (!argv0 || !argv0[1])
706 die ("Missing branch name; try -b");
707 opts.new_branch = argv0 + 1;
708 }
709
710 if (opts.new_orphan_branch) {
711 if (opts.new_branch)
712 die("--orphan and -b are mutually exclusive");
713 if (opts.track > 0)
714 die("--orphan cannot be used with -t");
715 opts.new_branch = opts.new_orphan_branch;
716 }
717
718 if (conflict_style) {
719 opts.merge = 1; /* implied */
720 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
721 }
722
723 if (opts.force && opts.merge)
724 die("git checkout: -f and -m are incompatible");
725
726 /*
727 * case 1: git checkout <ref> -- [<paths>]
728 *
729 * <ref> must be a valid tree, everything after the '--' must be
730 * a path.
731 *
732 * case 2: git checkout -- [<paths>]
733 *
734 * everything after the '--' must be paths.
735 *
736 * case 3: git checkout <something> [<paths>]
737 *
738 * With no paths, if <something> is a commit, that is to
739 * switch to the branch or detach HEAD at it. As a special case,
740 * if <something> is A...B (missing A or B means HEAD but you can
741 * omit at most one side), and if there is a unique merge base
742 * between A and B, A...B names that merge base.
743 *
744 * With no paths, if <something> is _not_ a commit, no -t nor -b
745 * was given, and there is a tracking branch whose name is
746 * <something> in one and only one remote, then this is a short-hand
747 * to fork local <something> from that remote tracking branch.
748 *
749 * Otherwise <something> shall not be ambiguous.
750 * - If it's *only* a reference, treat it like case (1).
751 * - If it's only a path, treat it like case (2).
752 * - else: fail.
753 *
754 */
755 if (argc) {
756 if (!strcmp(argv[0], "--")) { /* case (2) */
757 argv++;
758 argc--;
759 goto no_reference;
760 }
761
762 arg = argv[0];
763 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
764
765 if (!strcmp(arg, "-"))
766 arg = "@{-1}";
767
768 if (get_sha1_mb(arg, rev)) {
769 if (has_dash_dash) /* case (1) */
770 die("invalid reference: %s", arg);
771 if (!patch_mode &&
772 dwim_new_local_branch &&
773 opts.track == BRANCH_TRACK_UNSPECIFIED &&
774 !opts.new_branch &&
775 !check_filename(NULL, arg) &&
776 argc == 1) {
777 const char *remote = unique_tracking_name(arg);
778 if (!remote || get_sha1(remote, rev))
779 goto no_reference;
780 opts.new_branch = arg;
781 arg = remote;
782 /* DWIMmed to create local branch */
783 }
784 else
785 goto no_reference;
786 }
787
788 /* we can't end up being in (2) anymore, eat the argument */
789 argv++;
790 argc--;
791
792 new.name = arg;
793 if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
794 setup_branch_path(&new);
795
796 if ((check_ref_format(new.path) == CHECK_REF_FORMAT_OK) &&
797 resolve_ref(new.path, rev, 1, NULL))
798 ;
799 else
800 new.path = NULL;
801 parse_commit(new.commit);
802 source_tree = new.commit->tree;
803 } else
804 source_tree = parse_tree_indirect(rev);
805
806 if (!source_tree) /* case (1): want a tree */
807 die("reference is not a tree: %s", arg);
808 if (!has_dash_dash) {/* case (3 -> 1) */
809 /*
810 * Do not complain the most common case
811 * git checkout branch
812 * even if there happen to be a file called 'branch';
813 * it would be extremely annoying.
814 */
815 if (argc)
816 verify_non_filename(NULL, arg);
817 }
818 else {
819 argv++;
820 argc--;
821 }
822 }
823
824 no_reference:
825
826 if (opts.track == BRANCH_TRACK_UNSPECIFIED)
827 opts.track = git_branch_track;
828
829 if (argc) {
830 const char **pathspec = get_pathspec(prefix, argv);
831
832 if (!pathspec)
833 die("invalid path specification");
834
835 if (patch_mode)
836 return interactive_checkout(new.name, pathspec, &opts);
837
838 /* Checkout paths */
839 if (opts.new_branch) {
840 if (argc == 1) {
841 die("git checkout: updating paths is incompatible with switching branches.\nDid you intend to checkout '%s' which can not be resolved as commit?", argv[0]);
842 } else {
843 die("git checkout: updating paths is incompatible with switching branches.");
844 }
845 }
846
847 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
848 die("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index.");
849
850 return checkout_paths(source_tree, pathspec, &opts);
851 }
852
853 if (patch_mode)
854 return interactive_checkout(new.name, NULL, &opts);
855
856 if (opts.new_branch) {
857 struct strbuf buf = STRBUF_INIT;
858 if (strbuf_check_branch_ref(&buf, opts.new_branch))
859 die("git checkout: we do not like '%s' as a branch name.",
860 opts.new_branch);
861 if (!get_sha1(buf.buf, rev))
862 die("git checkout: branch %s already exists", opts.new_branch);
863 strbuf_release(&buf);
864 }
865
866 if (new.name && !new.commit) {
867 die("Cannot switch branch to a non-commit.");
868 }
869 if (opts.writeout_stage)
870 die("--ours/--theirs is incompatible with switching branches.");
871
872 return switch_branches(&opts, &new);
873 }