Merge branch 'jc/maint-1.6.1-checkout-m-custom-merge' into maint
[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
21 static const char * const checkout_usage[] = {
22 "git checkout [options] <branch>",
23 "git checkout [options] [<branch>] -- <file>...",
24 NULL,
25 };
26
27 struct checkout_opts {
28 int quiet;
29 int merge;
30 int force;
31 int writeout_stage;
32 int writeout_error;
33
34 const char *new_branch;
35 int new_branch_log;
36 enum branch_track track;
37 };
38
39 static int post_checkout_hook(struct commit *old, struct commit *new,
40 int changed)
41 {
42 return run_hook(NULL, "post-checkout",
43 sha1_to_hex(old ? old->object.sha1 : null_sha1),
44 sha1_to_hex(new ? new->object.sha1 : null_sha1),
45 changed ? "1" : "0", NULL);
46 /* "new" can be NULL when checking out from the index before
47 a commit exists. */
48
49 }
50
51 static int update_some(const unsigned char *sha1, const char *base, int baselen,
52 const char *pathname, unsigned mode, int stage, void *context)
53 {
54 int len;
55 struct cache_entry *ce;
56
57 if (S_ISDIR(mode))
58 return READ_TREE_RECURSIVE;
59
60 len = baselen + strlen(pathname);
61 ce = xcalloc(1, cache_entry_size(len));
62 hashcpy(ce->sha1, sha1);
63 memcpy(ce->name, base, baselen);
64 memcpy(ce->name + baselen, pathname, len - baselen);
65 ce->ce_flags = create_ce_flags(len, 0);
66 ce->ce_mode = create_ce_mode(mode);
67 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
68 return 0;
69 }
70
71 static int read_tree_some(struct tree *tree, const char **pathspec)
72 {
73 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
74
75 /* update the index with the given tree's info
76 * for all args, expanding wildcards, and exit
77 * with any non-zero return code.
78 */
79 return 0;
80 }
81
82 static int skip_same_name(struct cache_entry *ce, int pos)
83 {
84 while (++pos < active_nr &&
85 !strcmp(active_cache[pos]->name, ce->name))
86 ; /* skip */
87 return pos;
88 }
89
90 static int check_stage(int stage, struct cache_entry *ce, int pos)
91 {
92 while (pos < active_nr &&
93 !strcmp(active_cache[pos]->name, ce->name)) {
94 if (ce_stage(active_cache[pos]) == stage)
95 return 0;
96 pos++;
97 }
98 return error("path '%s' does not have %s version",
99 ce->name,
100 (stage == 2) ? "our" : "their");
101 }
102
103 static int check_all_stages(struct cache_entry *ce, int pos)
104 {
105 if (ce_stage(ce) != 1 ||
106 active_nr <= pos + 2 ||
107 strcmp(active_cache[pos+1]->name, ce->name) ||
108 ce_stage(active_cache[pos+1]) != 2 ||
109 strcmp(active_cache[pos+2]->name, ce->name) ||
110 ce_stage(active_cache[pos+2]) != 3)
111 return error("path '%s' does not have all three versions",
112 ce->name);
113 return 0;
114 }
115
116 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
117 struct checkout *state)
118 {
119 while (pos < active_nr &&
120 !strcmp(active_cache[pos]->name, ce->name)) {
121 if (ce_stage(active_cache[pos]) == stage)
122 return checkout_entry(active_cache[pos], state, NULL);
123 pos++;
124 }
125 return error("path '%s' does not have %s version",
126 ce->name,
127 (stage == 2) ? "our" : "their");
128 }
129
130 /* NEEDSWORK: share with merge-recursive */
131 static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
132 {
133 unsigned long size;
134 enum object_type type;
135
136 if (!hashcmp(sha1, null_sha1)) {
137 mm->ptr = xstrdup("");
138 mm->size = 0;
139 return;
140 }
141
142 mm->ptr = read_sha1_file(sha1, &type, &size);
143 if (!mm->ptr || type != OBJ_BLOB)
144 die("unable to read blob object %s", sha1_to_hex(sha1));
145 mm->size = size;
146 }
147
148 static int checkout_merged(int pos, struct checkout *state)
149 {
150 struct cache_entry *ce = active_cache[pos];
151 const char *path = ce->name;
152 mmfile_t ancestor, ours, theirs;
153 int status;
154 unsigned char sha1[20];
155 mmbuffer_t result_buf;
156
157 if (ce_stage(ce) != 1 ||
158 active_nr <= pos + 2 ||
159 strcmp(active_cache[pos+1]->name, path) ||
160 ce_stage(active_cache[pos+1]) != 2 ||
161 strcmp(active_cache[pos+2]->name, path) ||
162 ce_stage(active_cache[pos+2]) != 3)
163 return error("path '%s' does not have all 3 versions", path);
164
165 fill_mm(active_cache[pos]->sha1, &ancestor);
166 fill_mm(active_cache[pos+1]->sha1, &ours);
167 fill_mm(active_cache[pos+2]->sha1, &theirs);
168
169 status = ll_merge(&result_buf, path, &ancestor,
170 &ours, "ours", &theirs, "theirs", 0);
171 free(ancestor.ptr);
172 free(ours.ptr);
173 free(theirs.ptr);
174 if (status < 0 || !result_buf.ptr) {
175 free(result_buf.ptr);
176 return error("path '%s': cannot merge", path);
177 }
178
179 /*
180 * NEEDSWORK:
181 * There is absolutely no reason to write this as a blob object
182 * and create a phony cache entry just to leak. This hack is
183 * primarily to get to the write_entry() machinery that massages
184 * the contents to work-tree format and writes out which only
185 * allows it for a cache entry. The code in write_entry() needs
186 * to be refactored to allow us to feed a <buffer, size, mode>
187 * instead of a cache entry. Such a refactoring would help
188 * merge_recursive as well (it also writes the merge result to the
189 * object database even when it may contain conflicts).
190 */
191 if (write_sha1_file(result_buf.ptr, result_buf.size,
192 blob_type, sha1))
193 die("Unable to add merge result for '%s'", path);
194 ce = make_cache_entry(create_ce_mode(active_cache[pos+1]->ce_mode),
195 sha1,
196 path, 2, 0);
197 if (!ce)
198 die("make_cache_entry failed for path '%s'", path);
199 status = checkout_entry(ce, state, NULL);
200 return status;
201 }
202
203 static int checkout_paths(struct tree *source_tree, const char **pathspec,
204 struct checkout_opts *opts)
205 {
206 int pos;
207 struct checkout state;
208 static char *ps_matched;
209 unsigned char rev[20];
210 int flag;
211 struct commit *head;
212 int errs = 0;
213 int stage = opts->writeout_stage;
214 int merge = opts->merge;
215 int newfd;
216 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
217
218 newfd = hold_locked_index(lock_file, 1);
219 if (read_cache_preload(pathspec) < 0)
220 return error("corrupt index file");
221
222 if (source_tree)
223 read_tree_some(source_tree, pathspec);
224
225 for (pos = 0; pathspec[pos]; pos++)
226 ;
227 ps_matched = xcalloc(1, pos);
228
229 for (pos = 0; pos < active_nr; pos++) {
230 struct cache_entry *ce = active_cache[pos];
231 match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, ps_matched);
232 }
233
234 if (report_path_error(ps_matched, pathspec, 0))
235 return 1;
236
237 /* Any unmerged paths? */
238 for (pos = 0; pos < active_nr; pos++) {
239 struct cache_entry *ce = active_cache[pos];
240 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
241 if (!ce_stage(ce))
242 continue;
243 if (opts->force) {
244 warning("path '%s' is unmerged", ce->name);
245 } else if (stage) {
246 errs |= check_stage(stage, ce, pos);
247 } else if (opts->merge) {
248 errs |= check_all_stages(ce, pos);
249 } else {
250 errs = 1;
251 error("path '%s' is unmerged", ce->name);
252 }
253 pos = skip_same_name(ce, pos) - 1;
254 }
255 }
256 if (errs)
257 return 1;
258
259 /* Now we are committed to check them out */
260 memset(&state, 0, sizeof(state));
261 state.force = 1;
262 state.refresh_cache = 1;
263 for (pos = 0; pos < active_nr; pos++) {
264 struct cache_entry *ce = active_cache[pos];
265 if (match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, NULL)) {
266 if (!ce_stage(ce)) {
267 errs |= checkout_entry(ce, &state, NULL);
268 continue;
269 }
270 if (stage)
271 errs |= checkout_stage(stage, ce, pos, &state);
272 else if (merge)
273 errs |= checkout_merged(pos, &state);
274 pos = skip_same_name(ce, pos) - 1;
275 }
276 }
277
278 if (write_cache(newfd, active_cache, active_nr) ||
279 commit_locked_index(lock_file))
280 die("unable to write new index file");
281
282 resolve_ref("HEAD", rev, 0, &flag);
283 head = lookup_commit_reference_gently(rev, 1);
284
285 errs |= post_checkout_hook(head, head, 0);
286 return errs;
287 }
288
289 static void show_local_changes(struct object *head)
290 {
291 struct rev_info rev;
292 /* I think we want full paths, even if we're in a subdirectory. */
293 init_revisions(&rev, NULL);
294 rev.abbrev = 0;
295 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
296 if (diff_setup_done(&rev.diffopt) < 0)
297 die("diff_setup_done failed");
298 add_pending_object(&rev, head, NULL);
299 run_diff_index(&rev, 0);
300 }
301
302 static void describe_detached_head(char *msg, struct commit *commit)
303 {
304 struct strbuf sb = STRBUF_INIT;
305 struct pretty_print_context ctx = {0};
306 parse_commit(commit);
307 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, &ctx);
308 fprintf(stderr, "%s %s... %s\n", msg,
309 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
310 strbuf_release(&sb);
311 }
312
313 static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
314 {
315 struct unpack_trees_options opts;
316 struct tree_desc tree_desc;
317
318 memset(&opts, 0, sizeof(opts));
319 opts.head_idx = -1;
320 opts.update = worktree;
321 opts.skip_unmerged = !worktree;
322 opts.reset = 1;
323 opts.merge = 1;
324 opts.fn = oneway_merge;
325 opts.verbose_update = !o->quiet;
326 opts.src_index = &the_index;
327 opts.dst_index = &the_index;
328 parse_tree(tree);
329 init_tree_desc(&tree_desc, tree->buffer, tree->size);
330 switch (unpack_trees(1, &tree_desc, &opts)) {
331 case -2:
332 o->writeout_error = 1;
333 /*
334 * We return 0 nevertheless, as the index is all right
335 * and more importantly we have made best efforts to
336 * update paths in the work tree, and we cannot revert
337 * them.
338 */
339 case 0:
340 return 0;
341 default:
342 return 128;
343 }
344 }
345
346 struct branch_info {
347 const char *name; /* The short name used */
348 const char *path; /* The full name of a real branch */
349 struct commit *commit; /* The named commit */
350 };
351
352 static void setup_branch_path(struct branch_info *branch)
353 {
354 struct strbuf buf = STRBUF_INIT;
355
356 strbuf_branchname(&buf, branch->name);
357 if (strcmp(buf.buf, branch->name))
358 branch->name = xstrdup(buf.buf);
359 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
360 branch->path = strbuf_detach(&buf, NULL);
361 }
362
363 static int merge_working_tree(struct checkout_opts *opts,
364 struct branch_info *old, struct branch_info *new)
365 {
366 int ret;
367 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
368 int newfd = hold_locked_index(lock_file, 1);
369
370 if (read_cache_preload(NULL) < 0)
371 return error("corrupt index file");
372
373 if (opts->force) {
374 ret = reset_tree(new->commit->tree, opts, 1);
375 if (ret)
376 return ret;
377 } else {
378 struct tree_desc trees[2];
379 struct tree *tree;
380 struct unpack_trees_options topts;
381
382 memset(&topts, 0, sizeof(topts));
383 topts.head_idx = -1;
384 topts.src_index = &the_index;
385 topts.dst_index = &the_index;
386
387 topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
388
389 refresh_cache(REFRESH_QUIET);
390
391 if (unmerged_cache()) {
392 error("you need to resolve your current index first");
393 return 1;
394 }
395
396 /* 2-way merge to the new branch */
397 topts.initial_checkout = is_cache_unborn();
398 topts.update = 1;
399 topts.merge = 1;
400 topts.gently = opts->merge && old->commit;
401 topts.verbose_update = !opts->quiet;
402 topts.fn = twoway_merge;
403 topts.dir = xcalloc(1, sizeof(*topts.dir));
404 topts.dir->flags |= DIR_SHOW_IGNORED;
405 topts.dir->exclude_per_dir = ".gitignore";
406 tree = parse_tree_indirect(old->commit ?
407 old->commit->object.sha1 :
408 (unsigned char *)EMPTY_TREE_SHA1_BIN);
409 init_tree_desc(&trees[0], tree->buffer, tree->size);
410 tree = parse_tree_indirect(new->commit->object.sha1);
411 init_tree_desc(&trees[1], tree->buffer, tree->size);
412
413 ret = unpack_trees(2, trees, &topts);
414 if (ret == -1) {
415 /*
416 * Unpack couldn't do a trivial merge; either
417 * give up or do a real merge, depending on
418 * whether the merge flag was used.
419 */
420 struct tree *result;
421 struct tree *work;
422 struct merge_options o;
423 if (!opts->merge)
424 return 1;
425
426 /*
427 * Without old->commit, the below is the same as
428 * the two-tree unpack we already tried and failed.
429 */
430 if (!old->commit)
431 return 1;
432
433 /* Do more real merge */
434
435 /*
436 * We update the index fully, then write the
437 * tree from the index, then merge the new
438 * branch with the current tree, with the old
439 * branch as the base. Then we reset the index
440 * (but not the working tree) to the new
441 * branch, leaving the working tree as the
442 * merged version, but skipping unmerged
443 * entries in the index.
444 */
445
446 add_files_to_cache(NULL, NULL, 0);
447 init_merge_options(&o);
448 o.verbosity = 0;
449 work = write_tree_from_memory(&o);
450
451 ret = reset_tree(new->commit->tree, opts, 1);
452 if (ret)
453 return ret;
454 o.branch1 = new->name;
455 o.branch2 = "local";
456 merge_trees(&o, new->commit->tree, work,
457 old->commit->tree, &result);
458 ret = reset_tree(new->commit->tree, opts, 0);
459 if (ret)
460 return ret;
461 }
462 }
463
464 if (write_cache(newfd, active_cache, active_nr) ||
465 commit_locked_index(lock_file))
466 die("unable to write new index file");
467
468 if (!opts->force && !opts->quiet)
469 show_local_changes(&new->commit->object);
470
471 return 0;
472 }
473
474 static void report_tracking(struct branch_info *new)
475 {
476 struct strbuf sb = STRBUF_INIT;
477 struct branch *branch = branch_get(new->name);
478
479 if (!format_tracking_info(branch, &sb))
480 return;
481 fputs(sb.buf, stdout);
482 strbuf_release(&sb);
483 }
484
485 static void update_refs_for_switch(struct checkout_opts *opts,
486 struct branch_info *old,
487 struct branch_info *new)
488 {
489 struct strbuf msg = STRBUF_INIT;
490 const char *old_desc;
491 if (opts->new_branch) {
492 create_branch(old->name, opts->new_branch, new->name, 0,
493 opts->new_branch_log, opts->track);
494 new->name = opts->new_branch;
495 setup_branch_path(new);
496 }
497
498 old_desc = old->name;
499 if (!old_desc && old->commit)
500 old_desc = sha1_to_hex(old->commit->object.sha1);
501 strbuf_addf(&msg, "checkout: moving from %s to %s",
502 old_desc ? old_desc : "(invalid)", new->name);
503
504 if (new->path) {
505 create_symref("HEAD", new->path, msg.buf);
506 if (!opts->quiet) {
507 if (old->path && !strcmp(new->path, old->path))
508 fprintf(stderr, "Already on '%s'\n",
509 new->name);
510 else
511 fprintf(stderr, "Switched to%s branch '%s'\n",
512 opts->new_branch ? " a new" : "",
513 new->name);
514 }
515 } else if (strcmp(new->name, "HEAD")) {
516 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
517 REF_NODEREF, DIE_ON_ERR);
518 if (!opts->quiet) {
519 if (old->path)
520 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);
521 describe_detached_head("HEAD is now at", new->commit);
522 }
523 }
524 remove_branch_state();
525 strbuf_release(&msg);
526 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
527 report_tracking(new);
528 }
529
530 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
531 {
532 int ret = 0;
533 struct branch_info old;
534 unsigned char rev[20];
535 int flag;
536 memset(&old, 0, sizeof(old));
537 old.path = resolve_ref("HEAD", rev, 0, &flag);
538 old.commit = lookup_commit_reference_gently(rev, 1);
539 if (!(flag & REF_ISSYMREF))
540 old.path = NULL;
541
542 if (old.path && !prefixcmp(old.path, "refs/heads/"))
543 old.name = old.path + strlen("refs/heads/");
544
545 if (!new->name) {
546 new->name = "HEAD";
547 new->commit = old.commit;
548 if (!new->commit)
549 die("You are on a branch yet to be born");
550 parse_commit(new->commit);
551 }
552
553 ret = merge_working_tree(opts, &old, new);
554 if (ret)
555 return ret;
556
557 /*
558 * If we were on a detached HEAD, but have now moved to
559 * a new commit, we want to mention the old commit once more
560 * to remind the user that it might be lost.
561 */
562 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
563 describe_detached_head("Previous HEAD position was", old.commit);
564
565 update_refs_for_switch(opts, &old, new);
566
567 ret = post_checkout_hook(old.commit, new->commit, 1);
568 return ret || opts->writeout_error;
569 }
570
571 static int git_checkout_config(const char *var, const char *value, void *cb)
572 {
573 return git_xmerge_config(var, value, cb);
574 }
575
576 static int interactive_checkout(const char *revision, const char **pathspec,
577 struct checkout_opts *opts)
578 {
579 return run_add_interactive(revision, "--patch=checkout", pathspec);
580 }
581
582 struct tracking_name_data {
583 const char *name;
584 char *remote;
585 int unique;
586 };
587
588 static int check_tracking_name(const char *refname, const unsigned char *sha1,
589 int flags, void *cb_data)
590 {
591 struct tracking_name_data *cb = cb_data;
592 const char *slash;
593
594 if (prefixcmp(refname, "refs/remotes/"))
595 return 0;
596 slash = strchr(refname + 13, '/');
597 if (!slash || strcmp(slash + 1, cb->name))
598 return 0;
599 if (cb->remote) {
600 cb->unique = 0;
601 return 0;
602 }
603 cb->remote = xstrdup(refname);
604 return 0;
605 }
606
607 static const char *unique_tracking_name(const char *name)
608 {
609 struct tracking_name_data cb_data = { name, NULL, 1 };
610 for_each_ref(check_tracking_name, &cb_data);
611 if (cb_data.unique)
612 return cb_data.remote;
613 free(cb_data.remote);
614 return NULL;
615 }
616
617 int cmd_checkout(int argc, const char **argv, const char *prefix)
618 {
619 struct checkout_opts opts;
620 unsigned char rev[20];
621 const char *arg;
622 struct branch_info new;
623 struct tree *source_tree = NULL;
624 char *conflict_style = NULL;
625 int patch_mode = 0;
626 int dwim_new_local_branch = 1;
627 struct option options[] = {
628 OPT__QUIET(&opts.quiet),
629 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
630 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
631 OPT_SET_INT('t', "track", &opts.track, "track",
632 BRANCH_TRACK_EXPLICIT),
633 OPT_SET_INT('2', "ours", &opts.writeout_stage, "stage",
634 2),
635 OPT_SET_INT('3', "theirs", &opts.writeout_stage, "stage",
636 3),
637 OPT_BOOLEAN('f', "force", &opts.force, "force"),
638 OPT_BOOLEAN('m', "merge", &opts.merge, "merge"),
639 OPT_STRING(0, "conflict", &conflict_style, "style",
640 "conflict style (merge or diff3)"),
641 OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
642 { OPTION_BOOLEAN, 0, "guess", &dwim_new_local_branch, NULL,
643 "second guess 'git checkout no-such-branch'",
644 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
645 OPT_END(),
646 };
647 int has_dash_dash;
648
649 memset(&opts, 0, sizeof(opts));
650 memset(&new, 0, sizeof(new));
651
652 git_config(git_checkout_config, NULL);
653
654 opts.track = BRANCH_TRACK_UNSPECIFIED;
655
656 argc = parse_options(argc, argv, prefix, options, checkout_usage,
657 PARSE_OPT_KEEP_DASHDASH);
658
659 if (patch_mode && (opts.track > 0 || opts.new_branch
660 || opts.new_branch_log || opts.merge || opts.force))
661 die ("--patch is incompatible with all other options");
662
663 /* --track without -b should DWIM */
664 if (0 < opts.track && !opts.new_branch) {
665 const char *argv0 = argv[0];
666 if (!argc || !strcmp(argv0, "--"))
667 die ("--track needs a branch name");
668 if (!prefixcmp(argv0, "refs/"))
669 argv0 += 5;
670 if (!prefixcmp(argv0, "remotes/"))
671 argv0 += 8;
672 argv0 = strchr(argv0, '/');
673 if (!argv0 || !argv0[1])
674 die ("Missing branch name; try -b");
675 opts.new_branch = argv0 + 1;
676 }
677
678 if (conflict_style) {
679 opts.merge = 1; /* implied */
680 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
681 }
682
683 if (opts.force && opts.merge)
684 die("git checkout: -f and -m are incompatible");
685
686 /*
687 * case 1: git checkout <ref> -- [<paths>]
688 *
689 * <ref> must be a valid tree, everything after the '--' must be
690 * a path.
691 *
692 * case 2: git checkout -- [<paths>]
693 *
694 * everything after the '--' must be paths.
695 *
696 * case 3: git checkout <something> [<paths>]
697 *
698 * With no paths, if <something> is a commit, that is to
699 * switch to the branch or detach HEAD at it.
700 *
701 * With no paths, if <something> is _not_ a commit, no -t nor -b
702 * was given, and there is a tracking branch whose name is
703 * <something> in one and only one remote, then this is a short-hand
704 * to fork local <something> from that remote tracking branch.
705 *
706 * Otherwise <something> shall not be ambiguous.
707 * - If it's *only* a reference, treat it like case (1).
708 * - If it's only a path, treat it like case (2).
709 * - else: fail.
710 *
711 */
712 if (argc) {
713 if (!strcmp(argv[0], "--")) { /* case (2) */
714 argv++;
715 argc--;
716 goto no_reference;
717 }
718
719 arg = argv[0];
720 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
721
722 if (!strcmp(arg, "-"))
723 arg = "@{-1}";
724
725 if (get_sha1(arg, rev)) {
726 if (has_dash_dash) /* case (1) */
727 die("invalid reference: %s", arg);
728 if (!patch_mode &&
729 dwim_new_local_branch &&
730 opts.track == BRANCH_TRACK_UNSPECIFIED &&
731 !opts.new_branch &&
732 !check_filename(NULL, arg) &&
733 argc == 1) {
734 const char *remote = unique_tracking_name(arg);
735 if (!remote || get_sha1(remote, rev))
736 goto no_reference;
737 opts.new_branch = arg;
738 arg = remote;
739 /* DWIMmed to create local branch */
740 }
741 else
742 goto no_reference;
743 }
744
745 /* we can't end up being in (2) anymore, eat the argument */
746 argv++;
747 argc--;
748
749 new.name = arg;
750 if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
751 setup_branch_path(&new);
752 if (resolve_ref(new.path, rev, 1, NULL))
753 new.commit = lookup_commit_reference(rev);
754 else
755 new.path = NULL;
756 parse_commit(new.commit);
757 source_tree = new.commit->tree;
758 } else
759 source_tree = parse_tree_indirect(rev);
760
761 if (!source_tree) /* case (1): want a tree */
762 die("reference is not a tree: %s", arg);
763 if (!has_dash_dash) {/* case (3 -> 1) */
764 /*
765 * Do not complain the most common case
766 * git checkout branch
767 * even if there happen to be a file called 'branch';
768 * it would be extremely annoying.
769 */
770 if (argc)
771 verify_non_filename(NULL, arg);
772 }
773 else {
774 argv++;
775 argc--;
776 }
777 }
778
779 no_reference:
780
781 if (opts.track == BRANCH_TRACK_UNSPECIFIED)
782 opts.track = git_branch_track;
783
784 if (argc) {
785 const char **pathspec = get_pathspec(prefix, argv);
786
787 if (!pathspec)
788 die("invalid path specification");
789
790 if (patch_mode)
791 return interactive_checkout(new.name, pathspec, &opts);
792
793 /* Checkout paths */
794 if (opts.new_branch) {
795 if (argc == 1) {
796 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]);
797 } else {
798 die("git checkout: updating paths is incompatible with switching branches.");
799 }
800 }
801
802 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
803 die("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index.");
804
805 return checkout_paths(source_tree, pathspec, &opts);
806 }
807
808 if (patch_mode)
809 return interactive_checkout(new.name, NULL, &opts);
810
811 if (opts.new_branch) {
812 struct strbuf buf = STRBUF_INIT;
813 if (strbuf_check_branch_ref(&buf, opts.new_branch))
814 die("git checkout: we do not like '%s' as a branch name.",
815 opts.new_branch);
816 if (!get_sha1(buf.buf, rev))
817 die("git checkout: branch %s already exists", opts.new_branch);
818 strbuf_release(&buf);
819 }
820
821 if (new.name && !new.commit) {
822 die("Cannot switch branch to a non-commit.");
823 }
824 if (opts.writeout_stage)
825 die("--ours/--theirs is incompatible with switching branches.");
826
827 return switch_branches(&opts, &new);
828 }