resolve-undo: record resolved conflicts in a new index extension section
[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 int new_branch_log;
37 enum branch_track track;
38 };
39
40 static int post_checkout_hook(struct commit *old, struct commit *new,
41 int changed)
42 {
43 return run_hook(NULL, "post-checkout",
44 sha1_to_hex(old ? old->object.sha1 : null_sha1),
45 sha1_to_hex(new ? new->object.sha1 : null_sha1),
46 changed ? "1" : "0", NULL);
47 /* "new" can be NULL when checking out from the index before
48 a commit exists. */
49
50 }
51
52 static int update_some(const unsigned char *sha1, const char *base, int baselen,
53 const char *pathname, unsigned mode, int stage, void *context)
54 {
55 int len;
56 struct cache_entry *ce;
57
58 if (S_ISDIR(mode))
59 return READ_TREE_RECURSIVE;
60
61 len = baselen + strlen(pathname);
62 ce = xcalloc(1, cache_entry_size(len));
63 hashcpy(ce->sha1, sha1);
64 memcpy(ce->name, base, baselen);
65 memcpy(ce->name + baselen, pathname, len - baselen);
66 ce->ce_flags = create_ce_flags(len, 0);
67 ce->ce_mode = create_ce_mode(mode);
68 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
69 return 0;
70 }
71
72 static int read_tree_some(struct tree *tree, const char **pathspec)
73 {
74 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
75
76 /* update the index with the given tree's info
77 * for all args, expanding wildcards, and exit
78 * with any non-zero return code.
79 */
80 return 0;
81 }
82
83 static int skip_same_name(struct cache_entry *ce, int pos)
84 {
85 while (++pos < active_nr &&
86 !strcmp(active_cache[pos]->name, ce->name))
87 ; /* skip */
88 return pos;
89 }
90
91 static int check_stage(int stage, struct cache_entry *ce, int pos)
92 {
93 while (pos < active_nr &&
94 !strcmp(active_cache[pos]->name, ce->name)) {
95 if (ce_stage(active_cache[pos]) == stage)
96 return 0;
97 pos++;
98 }
99 return error("path '%s' does not have %s version",
100 ce->name,
101 (stage == 2) ? "our" : "their");
102 }
103
104 static int check_all_stages(struct cache_entry *ce, int pos)
105 {
106 if (ce_stage(ce) != 1 ||
107 active_nr <= pos + 2 ||
108 strcmp(active_cache[pos+1]->name, ce->name) ||
109 ce_stage(active_cache[pos+1]) != 2 ||
110 strcmp(active_cache[pos+2]->name, ce->name) ||
111 ce_stage(active_cache[pos+2]) != 3)
112 return error("path '%s' does not have all three versions",
113 ce->name);
114 return 0;
115 }
116
117 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
118 struct checkout *state)
119 {
120 while (pos < active_nr &&
121 !strcmp(active_cache[pos]->name, ce->name)) {
122 if (ce_stage(active_cache[pos]) == stage)
123 return checkout_entry(active_cache[pos], state, NULL);
124 pos++;
125 }
126 return error("path '%s' does not have %s version",
127 ce->name,
128 (stage == 2) ? "our" : "their");
129 }
130
131 /* NEEDSWORK: share with merge-recursive */
132 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
133 {
134 unsigned long size;
135 enum object_type type;
136
137 if (!hashcmp(sha1, null_sha1)) {
138 mm->ptr = xstrdup("");
139 mm->size = 0;
140 return;
141 }
142
143 mm->ptr = read_sha1_file(sha1, &type, &size);
144 if (!mm->ptr || type != OBJ_BLOB)
145 die("unable to read blob object %s", sha1_to_hex(sha1));
146 mm->size = size;
147 }
148
149 static int checkout_merged(int pos, struct checkout *state)
150 {
151 struct cache_entry *ce = active_cache[pos];
152 const char *path = ce->name;
153 mmfile_t ancestor, ours, theirs;
154 int status;
155 unsigned char sha1[20];
156 mmbuffer_t result_buf;
157
158 if (ce_stage(ce) != 1 ||
159 active_nr <= pos + 2 ||
160 strcmp(active_cache[pos+1]->name, path) ||
161 ce_stage(active_cache[pos+1]) != 2 ||
162 strcmp(active_cache[pos+2]->name, path) ||
163 ce_stage(active_cache[pos+2]) != 3)
164 return error("path '%s' does not have all 3 versions", path);
165
166 fill_mm(active_cache[pos]->sha1, &ancestor);
167 fill_mm(active_cache[pos+1]->sha1, &ours);
168 fill_mm(active_cache[pos+2]->sha1, &theirs);
169
170 status = ll_merge(&result_buf, path, &ancestor,
171 &ours, "ours", &theirs, "theirs", 1);
172 free(ancestor.ptr);
173 free(ours.ptr);
174 free(theirs.ptr);
175 if (status < 0 || !result_buf.ptr) {
176 free(result_buf.ptr);
177 return error("path '%s': cannot merge", path);
178 }
179
180 /*
181 * NEEDSWORK:
182 * There is absolutely no reason to write this as a blob object
183 * and create a phony cache entry just to leak. This hack is
184 * primarily to get to the write_entry() machinery that massages
185 * the contents to work-tree format and writes out which only
186 * allows it for a cache entry. The code in write_entry() needs
187 * to be refactored to allow us to feed a <buffer, size, mode>
188 * instead of a cache entry. Such a refactoring would help
189 * merge_recursive as well (it also writes the merge result to the
190 * object database even when it may contain conflicts).
191 */
192 if (write_sha1_file(result_buf.ptr, result_buf.size,
193 blob_type, sha1))
194 die("Unable to add merge result for '%s'", path);
195 ce = make_cache_entry(create_ce_mode(active_cache[pos+1]->ce_mode),
196 sha1,
197 path, 2, 0);
198 if (!ce)
199 die("make_cache_entry failed for path '%s'", path);
200 status = checkout_entry(ce, state, NULL);
201 return status;
202 }
203
204 static int checkout_paths(struct tree *source_tree, const char **pathspec,
205 struct checkout_opts *opts)
206 {
207 int pos;
208 struct checkout state;
209 static char *ps_matched;
210 unsigned char rev[20];
211 int flag;
212 struct commit *head;
213 int errs = 0;
214 int stage = opts->writeout_stage;
215 int merge = opts->merge;
216 int newfd;
217 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
218
219 newfd = hold_locked_index(lock_file, 1);
220 if (read_cache_preload(pathspec) < 0)
221 return error("corrupt index file");
222
223 if (source_tree)
224 read_tree_some(source_tree, pathspec);
225
226 for (pos = 0; pathspec[pos]; pos++)
227 ;
228 ps_matched = xcalloc(1, pos);
229
230 for (pos = 0; pos < active_nr; pos++) {
231 struct cache_entry *ce = active_cache[pos];
232 match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, ps_matched);
233 }
234
235 if (report_path_error(ps_matched, pathspec, 0))
236 return 1;
237
238 /* Any unmerged paths? */
239 for (pos = 0; pos < active_nr; pos++) {
240 struct cache_entry *ce = active_cache[pos];
241 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
242 if (!ce_stage(ce))
243 continue;
244 if (opts->force) {
245 warning("path '%s' is unmerged", ce->name);
246 } else if (stage) {
247 errs |= check_stage(stage, ce, pos);
248 } else if (opts->merge) {
249 errs |= check_all_stages(ce, pos);
250 } else {
251 errs = 1;
252 error("path '%s' is unmerged", ce->name);
253 }
254 pos = skip_same_name(ce, pos) - 1;
255 }
256 }
257 if (errs)
258 return 1;
259
260 /* Now we are committed to check them out */
261 memset(&state, 0, sizeof(state));
262 state.force = 1;
263 state.refresh_cache = 1;
264 for (pos = 0; pos < active_nr; pos++) {
265 struct cache_entry *ce = active_cache[pos];
266 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
267 if (!ce_stage(ce)) {
268 errs |= checkout_entry(ce, &state, NULL);
269 continue;
270 }
271 if (stage)
272 errs |= checkout_stage(stage, ce, pos, &state);
273 else if (merge)
274 errs |= checkout_merged(pos, &state);
275 pos = skip_same_name(ce, pos) - 1;
276 }
277 }
278
279 if (write_cache(newfd, active_cache, active_nr) ||
280 commit_locked_index(lock_file))
281 die("unable to write new index file");
282
283 resolve_ref("HEAD", rev, 0, &flag);
284 head = lookup_commit_reference_gently(rev, 1);
285
286 errs |= post_checkout_hook(head, head, 0);
287 return errs;
288 }
289
290 static void show_local_changes(struct object *head)
291 {
292 struct rev_info rev;
293 /* I think we want full paths, even if we're in a subdirectory. */
294 init_revisions(&rev, NULL);
295 rev.abbrev = 0;
296 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
297 if (diff_setup_done(&rev.diffopt) < 0)
298 die("diff_setup_done failed");
299 add_pending_object(&rev, head, NULL);
300 run_diff_index(&rev, 0);
301 }
302
303 static void describe_detached_head(char *msg, struct commit *commit)
304 {
305 struct strbuf sb = STRBUF_INIT;
306 struct pretty_print_context ctx = {0};
307 parse_commit(commit);
308 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, &ctx);
309 fprintf(stderr, "%s %s... %s\n", msg,
310 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
311 strbuf_release(&sb);
312 }
313
314 static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
315 {
316 struct unpack_trees_options opts;
317 struct tree_desc tree_desc;
318
319 memset(&opts, 0, sizeof(opts));
320 opts.head_idx = -1;
321 opts.update = worktree;
322 opts.skip_unmerged = !worktree;
323 opts.reset = 1;
324 opts.merge = 1;
325 opts.fn = oneway_merge;
326 opts.verbose_update = !o->quiet;
327 opts.src_index = &the_index;
328 opts.dst_index = &the_index;
329 parse_tree(tree);
330 init_tree_desc(&tree_desc, tree->buffer, tree->size);
331 switch (unpack_trees(1, &tree_desc, &opts)) {
332 case -2:
333 o->writeout_error = 1;
334 /*
335 * We return 0 nevertheless, as the index is all right
336 * and more importantly we have made best efforts to
337 * update paths in the work tree, and we cannot revert
338 * them.
339 */
340 case 0:
341 return 0;
342 default:
343 return 128;
344 }
345 }
346
347 struct branch_info {
348 const char *name; /* The short name used */
349 const char *path; /* The full name of a real branch */
350 struct commit *commit; /* The named commit */
351 };
352
353 static void setup_branch_path(struct branch_info *branch)
354 {
355 struct strbuf buf = STRBUF_INIT;
356
357 strbuf_branchname(&buf, branch->name);
358 if (strcmp(buf.buf, branch->name))
359 branch->name = xstrdup(buf.buf);
360 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
361 branch->path = strbuf_detach(&buf, NULL);
362 }
363
364 static int merge_working_tree(struct checkout_opts *opts,
365 struct branch_info *old, struct branch_info *new)
366 {
367 int ret;
368 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
369 int newfd = hold_locked_index(lock_file, 1);
370
371 if (read_cache_preload(NULL) < 0)
372 return error("corrupt index file");
373
374 resolve_undo_clear();
375 if (opts->force) {
376 ret = reset_tree(new->commit->tree, opts, 1);
377 if (ret)
378 return ret;
379 } else {
380 struct tree_desc trees[2];
381 struct tree *tree;
382 struct unpack_trees_options topts;
383
384 memset(&topts, 0, sizeof(topts));
385 topts.head_idx = -1;
386 topts.src_index = &the_index;
387 topts.dst_index = &the_index;
388
389 topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
390
391 refresh_cache(REFRESH_QUIET);
392
393 if (unmerged_cache()) {
394 error("you need to resolve your current index first");
395 return 1;
396 }
397
398 /* 2-way merge to the new branch */
399 topts.initial_checkout = is_cache_unborn();
400 topts.update = 1;
401 topts.merge = 1;
402 topts.gently = opts->merge;
403 topts.verbose_update = !opts->quiet;
404 topts.fn = twoway_merge;
405 topts.dir = xcalloc(1, sizeof(*topts.dir));
406 topts.dir->flags |= DIR_SHOW_IGNORED;
407 topts.dir->exclude_per_dir = ".gitignore";
408 tree = parse_tree_indirect(old->commit ?
409 old->commit->object.sha1 :
410 (unsigned char *)EMPTY_TREE_SHA1_BIN);
411 init_tree_desc(&trees[0], tree->buffer, tree->size);
412 tree = parse_tree_indirect(new->commit->object.sha1);
413 init_tree_desc(&trees[1], tree->buffer, tree->size);
414
415 ret = unpack_trees(2, trees, &topts);
416 if (ret == -1) {
417 /*
418 * Unpack couldn't do a trivial merge; either
419 * give up or do a real merge, depending on
420 * whether the merge flag was used.
421 */
422 struct tree *result;
423 struct tree *work;
424 struct merge_options o;
425 if (!opts->merge)
426 return 1;
427 parse_commit(old->commit);
428
429 /* Do more real merge */
430
431 /*
432 * We update the index fully, then write the
433 * tree from the index, then merge the new
434 * branch with the current tree, with the old
435 * branch as the base. Then we reset the index
436 * (but not the working tree) to the new
437 * branch, leaving the working tree as the
438 * merged version, but skipping unmerged
439 * entries in the index.
440 */
441
442 add_files_to_cache(NULL, NULL, 0);
443 init_merge_options(&o);
444 o.verbosity = 0;
445 work = write_tree_from_memory(&o);
446
447 ret = reset_tree(new->commit->tree, opts, 1);
448 if (ret)
449 return ret;
450 o.branch1 = new->name;
451 o.branch2 = "local";
452 merge_trees(&o, new->commit->tree, work,
453 old->commit->tree, &result);
454 ret = reset_tree(new->commit->tree, opts, 0);
455 if (ret)
456 return ret;
457 }
458 }
459
460 if (write_cache(newfd, active_cache, active_nr) ||
461 commit_locked_index(lock_file))
462 die("unable to write new index file");
463
464 if (!opts->force && !opts->quiet)
465 show_local_changes(&new->commit->object);
466
467 return 0;
468 }
469
470 static void report_tracking(struct branch_info *new)
471 {
472 struct strbuf sb = STRBUF_INIT;
473 struct branch *branch = branch_get(new->name);
474
475 if (!format_tracking_info(branch, &sb))
476 return;
477 fputs(sb.buf, stdout);
478 strbuf_release(&sb);
479 }
480
481 static void update_refs_for_switch(struct checkout_opts *opts,
482 struct branch_info *old,
483 struct branch_info *new)
484 {
485 struct strbuf msg = STRBUF_INIT;
486 const char *old_desc;
487 if (opts->new_branch) {
488 create_branch(old->name, opts->new_branch, new->name, 0,
489 opts->new_branch_log, opts->track);
490 new->name = opts->new_branch;
491 setup_branch_path(new);
492 }
493
494 old_desc = old->name;
495 if (!old_desc && old->commit)
496 old_desc = sha1_to_hex(old->commit->object.sha1);
497 strbuf_addf(&msg, "checkout: moving from %s to %s",
498 old_desc ? old_desc : "(invalid)", new->name);
499
500 if (new->path) {
501 create_symref("HEAD", new->path, msg.buf);
502 if (!opts->quiet) {
503 if (old->path && !strcmp(new->path, old->path))
504 fprintf(stderr, "Already on '%s'\n",
505 new->name);
506 else
507 fprintf(stderr, "Switched to%s branch '%s'\n",
508 opts->new_branch ? " a new" : "",
509 new->name);
510 }
511 } else if (strcmp(new->name, "HEAD")) {
512 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
513 REF_NODEREF, DIE_ON_ERR);
514 if (!opts->quiet) {
515 if (old->path)
516 fprintf(stderr, "Note: moving to '%s' which isn't a local branch\nIf you want to create a new branch from this checkout, you may do so\n(now or later) by using -b with the checkout command again. Example:\n git checkout -b <new_branch_name>\n", new->name);
517 describe_detached_head("HEAD is now at", new->commit);
518 }
519 }
520 remove_branch_state();
521 strbuf_release(&msg);
522 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
523 report_tracking(new);
524 }
525
526 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
527 {
528 int ret = 0;
529 struct branch_info old;
530 unsigned char rev[20];
531 int flag;
532 memset(&old, 0, sizeof(old));
533 old.path = resolve_ref("HEAD", rev, 0, &flag);
534 old.commit = lookup_commit_reference_gently(rev, 1);
535 if (!(flag & REF_ISSYMREF))
536 old.path = NULL;
537
538 if (old.path && !prefixcmp(old.path, "refs/heads/"))
539 old.name = old.path + strlen("refs/heads/");
540
541 if (!new->name) {
542 new->name = "HEAD";
543 new->commit = old.commit;
544 if (!new->commit)
545 die("You are on a branch yet to be born");
546 parse_commit(new->commit);
547 }
548
549 ret = merge_working_tree(opts, &old, new);
550 if (ret)
551 return ret;
552
553 /*
554 * If we were on a detached HEAD, but have now moved to
555 * a new commit, we want to mention the old commit once more
556 * to remind the user that it might be lost.
557 */
558 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
559 describe_detached_head("Previous HEAD position was", old.commit);
560
561 update_refs_for_switch(opts, &old, new);
562
563 ret = post_checkout_hook(old.commit, new->commit, 1);
564 return ret || opts->writeout_error;
565 }
566
567 static int git_checkout_config(const char *var, const char *value, void *cb)
568 {
569 return git_xmerge_config(var, value, cb);
570 }
571
572 static int interactive_checkout(const char *revision, const char **pathspec,
573 struct checkout_opts *opts)
574 {
575 return run_add_interactive(revision, "--patch=checkout", pathspec);
576 }
577
578 struct tracking_name_data {
579 const char *name;
580 char *remote;
581 int unique;
582 };
583
584 static int check_tracking_name(const char *refname, const unsigned char *sha1,
585 int flags, void *cb_data)
586 {
587 struct tracking_name_data *cb = cb_data;
588 const char *slash;
589
590 if (prefixcmp(refname, "refs/remotes/"))
591 return 0;
592 slash = strchr(refname + 13, '/');
593 if (!slash || strcmp(slash + 1, cb->name))
594 return 0;
595 if (cb->remote) {
596 cb->unique = 0;
597 return 0;
598 }
599 cb->remote = xstrdup(refname);
600 return 0;
601 }
602
603 static const char *unique_tracking_name(const char *name)
604 {
605 struct tracking_name_data cb_data = { name, NULL, 1 };
606 for_each_ref(check_tracking_name, &cb_data);
607 if (cb_data.unique)
608 return cb_data.remote;
609 free(cb_data.remote);
610 return NULL;
611 }
612
613 int cmd_checkout(int argc, const char **argv, const char *prefix)
614 {
615 struct checkout_opts opts;
616 unsigned char rev[20];
617 const char *arg;
618 struct branch_info new;
619 struct tree *source_tree = NULL;
620 char *conflict_style = NULL;
621 int patch_mode = 0;
622 int dwim_new_local_branch = 1;
623 struct option options[] = {
624 OPT__QUIET(&opts.quiet),
625 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
626 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
627 OPT_SET_INT('t', "track", &opts.track, "track",
628 BRANCH_TRACK_EXPLICIT),
629 OPT_SET_INT('2', "ours", &opts.writeout_stage, "stage",
630 2),
631 OPT_SET_INT('3', "theirs", &opts.writeout_stage, "stage",
632 3),
633 OPT_BOOLEAN('f', "force", &opts.force, "force"),
634 OPT_BOOLEAN('m', "merge", &opts.merge, "merge"),
635 OPT_STRING(0, "conflict", &conflict_style, "style",
636 "conflict style (merge or diff3)"),
637 OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
638 { OPTION_BOOLEAN, 0, "guess", &dwim_new_local_branch, NULL,
639 "second guess 'git checkout no-such-branch'",
640 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
641 OPT_END(),
642 };
643 int has_dash_dash;
644
645 memset(&opts, 0, sizeof(opts));
646 memset(&new, 0, sizeof(new));
647
648 git_config(git_checkout_config, NULL);
649
650 opts.track = BRANCH_TRACK_UNSPECIFIED;
651
652 argc = parse_options(argc, argv, prefix, options, checkout_usage,
653 PARSE_OPT_KEEP_DASHDASH);
654
655 if (patch_mode && (opts.track > 0 || opts.new_branch
656 || opts.new_branch_log || opts.merge || opts.force))
657 die ("--patch is incompatible with all other options");
658
659 /* --track without -b should DWIM */
660 if (0 < opts.track && !opts.new_branch) {
661 const char *argv0 = argv[0];
662 if (!argc || !strcmp(argv0, "--"))
663 die ("--track needs a branch name");
664 if (!prefixcmp(argv0, "refs/"))
665 argv0 += 5;
666 if (!prefixcmp(argv0, "remotes/"))
667 argv0 += 8;
668 argv0 = strchr(argv0, '/');
669 if (!argv0 || !argv0[1])
670 die ("Missing branch name; try -b");
671 opts.new_branch = argv0 + 1;
672 }
673
674 if (conflict_style) {
675 opts.merge = 1; /* implied */
676 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
677 }
678
679 if (opts.force && opts.merge)
680 die("git checkout: -f and -m are incompatible");
681
682 /*
683 * case 1: git checkout <ref> -- [<paths>]
684 *
685 * <ref> must be a valid tree, everything after the '--' must be
686 * a path.
687 *
688 * case 2: git checkout -- [<paths>]
689 *
690 * everything after the '--' must be paths.
691 *
692 * case 3: git checkout <something> [<paths>]
693 *
694 * With no paths, if <something> is a commit, that is to
695 * switch to the branch or detach HEAD at it.
696 *
697 * With no paths, if <something> is _not_ a commit, no -t nor -b
698 * was given, and there is a tracking branch whose name is
699 * <something> in one and only one remote, then this is a short-hand
700 * to fork local <something> from that remote tracking branch.
701 *
702 * Otherwise <something> shall not be ambiguous.
703 * - If it's *only* a reference, treat it like case (1).
704 * - If it's only a path, treat it like case (2).
705 * - else: fail.
706 *
707 */
708 if (argc) {
709 if (!strcmp(argv[0], "--")) { /* case (2) */
710 argv++;
711 argc--;
712 goto no_reference;
713 }
714
715 arg = argv[0];
716 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
717
718 if (!strcmp(arg, "-"))
719 arg = "@{-1}";
720
721 if (get_sha1(arg, rev)) {
722 if (has_dash_dash) /* case (1) */
723 die("invalid reference: %s", arg);
724 if (!patch_mode &&
725 dwim_new_local_branch &&
726 opts.track == BRANCH_TRACK_UNSPECIFIED &&
727 !opts.new_branch &&
728 !check_filename(NULL, arg) &&
729 argc == 1) {
730 const char *remote = unique_tracking_name(arg);
731 if (!remote || get_sha1(remote, rev))
732 goto no_reference;
733 opts.new_branch = arg;
734 arg = remote;
735 /* DWIMmed to create local branch */
736 }
737 else
738 goto no_reference;
739 }
740
741 /* we can't end up being in (2) anymore, eat the argument */
742 argv++;
743 argc--;
744
745 new.name = arg;
746 if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
747 setup_branch_path(&new);
748 if (resolve_ref(new.path, rev, 1, NULL))
749 new.commit = lookup_commit_reference(rev);
750 else
751 new.path = NULL;
752 parse_commit(new.commit);
753 source_tree = new.commit->tree;
754 } else
755 source_tree = parse_tree_indirect(rev);
756
757 if (!source_tree) /* case (1): want a tree */
758 die("reference is not a tree: %s", arg);
759 if (!has_dash_dash) {/* case (3 -> 1) */
760 /*
761 * Do not complain the most common case
762 * git checkout branch
763 * even if there happen to be a file called 'branch';
764 * it would be extremely annoying.
765 */
766 if (argc)
767 verify_non_filename(NULL, arg);
768 }
769 else {
770 argv++;
771 argc--;
772 }
773 }
774
775 no_reference:
776
777 if (opts.track == BRANCH_TRACK_UNSPECIFIED)
778 opts.track = git_branch_track;
779
780 if (argc) {
781 const char **pathspec = get_pathspec(prefix, argv);
782
783 if (!pathspec)
784 die("invalid path specification");
785
786 if (patch_mode)
787 return interactive_checkout(new.name, pathspec, &opts);
788
789 /* Checkout paths */
790 if (opts.new_branch) {
791 if (argc == 1) {
792 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]);
793 } else {
794 die("git checkout: updating paths is incompatible with switching branches.");
795 }
796 }
797
798 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
799 die("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index.");
800
801 return checkout_paths(source_tree, pathspec, &opts);
802 }
803
804 if (patch_mode)
805 return interactive_checkout(new.name, NULL, &opts);
806
807 if (opts.new_branch) {
808 struct strbuf buf = STRBUF_INIT;
809 if (strbuf_check_branch_ref(&buf, opts.new_branch))
810 die("git checkout: we do not like '%s' as a branch name.",
811 opts.new_branch);
812 if (!get_sha1(buf.buf, rev))
813 die("git checkout: branch %s already exists", opts.new_branch);
814 strbuf_release(&buf);
815 }
816
817 if (new.name && !new.commit) {
818 die("Cannot switch branch to a non-commit.");
819 }
820 if (opts.writeout_stage)
821 die("--ours/--theirs is incompatible with switching branches.");
822
823 return switch_branches(&opts, &new);
824 }