commit: fix patch hunk editing with "commit -p -m"
[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 #include "submodule.h"
22 #include "argv-array.h"
23
24 static const char * const checkout_usage[] = {
25 N_("git checkout [options] <branch>"),
26 N_("git checkout [options] [<branch>] -- <file>..."),
27 NULL,
28 };
29
30 struct checkout_opts {
31 int patch_mode;
32 int quiet;
33 int merge;
34 int force;
35 int force_detach;
36 int writeout_stage;
37 int overwrite_ignore;
38 int ignore_skipworktree;
39
40 const char *new_branch;
41 const char *new_branch_force;
42 const char *new_orphan_branch;
43 int new_branch_log;
44 enum branch_track track;
45 struct diff_options diff_options;
46
47 int branch_exists;
48 const char *prefix;
49 struct pathspec pathspec;
50 struct tree *source_tree;
51 };
52
53 static int post_checkout_hook(struct commit *old, struct commit *new,
54 int changed)
55 {
56 return run_hook_le(NULL, "post-checkout",
57 sha1_to_hex(old ? old->object.sha1 : null_sha1),
58 sha1_to_hex(new ? new->object.sha1 : null_sha1),
59 changed ? "1" : "0", NULL);
60 /* "new" can be NULL when checking out from the index before
61 a commit exists. */
62
63 }
64
65 static int update_some(const unsigned char *sha1, const char *base, int baselen,
66 const char *pathname, unsigned mode, int stage, void *context)
67 {
68 int len;
69 struct cache_entry *ce;
70
71 if (S_ISDIR(mode))
72 return READ_TREE_RECURSIVE;
73
74 len = baselen + strlen(pathname);
75 ce = xcalloc(1, cache_entry_size(len));
76 hashcpy(ce->sha1, sha1);
77 memcpy(ce->name, base, baselen);
78 memcpy(ce->name + baselen, pathname, len - baselen);
79 ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
80 ce->ce_namelen = len;
81 ce->ce_mode = create_ce_mode(mode);
82 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
83 return 0;
84 }
85
86 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
87 {
88 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
89
90 /* update the index with the given tree's info
91 * for all args, expanding wildcards, and exit
92 * with any non-zero return code.
93 */
94 return 0;
95 }
96
97 static int skip_same_name(const struct cache_entry *ce, int pos)
98 {
99 while (++pos < active_nr &&
100 !strcmp(active_cache[pos]->name, ce->name))
101 ; /* skip */
102 return pos;
103 }
104
105 static int check_stage(int stage, const struct cache_entry *ce, int pos)
106 {
107 while (pos < active_nr &&
108 !strcmp(active_cache[pos]->name, ce->name)) {
109 if (ce_stage(active_cache[pos]) == stage)
110 return 0;
111 pos++;
112 }
113 if (stage == 2)
114 return error(_("path '%s' does not have our version"), ce->name);
115 else
116 return error(_("path '%s' does not have their version"), ce->name);
117 }
118
119 static int check_stages(unsigned stages, const struct cache_entry *ce, int pos)
120 {
121 unsigned seen = 0;
122 const char *name = ce->name;
123
124 while (pos < active_nr) {
125 ce = active_cache[pos];
126 if (strcmp(name, ce->name))
127 break;
128 seen |= (1 << ce_stage(ce));
129 pos++;
130 }
131 if ((stages & seen) != stages)
132 return error(_("path '%s' does not have all necessary versions"),
133 name);
134 return 0;
135 }
136
137 static int checkout_stage(int stage, struct cache_entry *ce, int pos,
138 struct checkout *state)
139 {
140 while (pos < active_nr &&
141 !strcmp(active_cache[pos]->name, ce->name)) {
142 if (ce_stage(active_cache[pos]) == stage)
143 return checkout_entry(active_cache[pos], state, NULL);
144 pos++;
145 }
146 if (stage == 2)
147 return error(_("path '%s' does not have our version"), ce->name);
148 else
149 return error(_("path '%s' does not have their version"), ce->name);
150 }
151
152 static int checkout_merged(int pos, struct checkout *state)
153 {
154 struct cache_entry *ce = active_cache[pos];
155 const char *path = ce->name;
156 mmfile_t ancestor, ours, theirs;
157 int status;
158 unsigned char sha1[20];
159 mmbuffer_t result_buf;
160 unsigned char threeway[3][20];
161 unsigned mode = 0;
162
163 memset(threeway, 0, sizeof(threeway));
164 while (pos < active_nr) {
165 int stage;
166 stage = ce_stage(ce);
167 if (!stage || strcmp(path, ce->name))
168 break;
169 hashcpy(threeway[stage - 1], ce->sha1);
170 if (stage == 2)
171 mode = create_ce_mode(ce->ce_mode);
172 pos++;
173 ce = active_cache[pos];
174 }
175 if (is_null_sha1(threeway[1]) || is_null_sha1(threeway[2]))
176 return error(_("path '%s' does not have necessary versions"), path);
177
178 read_mmblob(&ancestor, threeway[0]);
179 read_mmblob(&ours, threeway[1]);
180 read_mmblob(&theirs, threeway[2]);
181
182 /*
183 * NEEDSWORK: re-create conflicts from merges with
184 * merge.renormalize set, too
185 */
186 status = ll_merge(&result_buf, path, &ancestor, "base",
187 &ours, "ours", &theirs, "theirs", NULL);
188 free(ancestor.ptr);
189 free(ours.ptr);
190 free(theirs.ptr);
191 if (status < 0 || !result_buf.ptr) {
192 free(result_buf.ptr);
193 return error(_("path '%s': cannot merge"), path);
194 }
195
196 /*
197 * NEEDSWORK:
198 * There is absolutely no reason to write this as a blob object
199 * and create a phony cache entry just to leak. This hack is
200 * primarily to get to the write_entry() machinery that massages
201 * the contents to work-tree format and writes out which only
202 * allows it for a cache entry. The code in write_entry() needs
203 * to be refactored to allow us to feed a <buffer, size, mode>
204 * instead of a cache entry. Such a refactoring would help
205 * merge_recursive as well (it also writes the merge result to the
206 * object database even when it may contain conflicts).
207 */
208 if (write_sha1_file(result_buf.ptr, result_buf.size,
209 blob_type, sha1))
210 die(_("Unable to add merge result for '%s'"), path);
211 ce = make_cache_entry(mode, sha1, path, 2, 0);
212 if (!ce)
213 die(_("make_cache_entry failed for path '%s'"), path);
214 status = checkout_entry(ce, state, NULL);
215 return status;
216 }
217
218 static int checkout_paths(const struct checkout_opts *opts,
219 const char *revision)
220 {
221 int pos;
222 struct checkout state;
223 static char *ps_matched;
224 unsigned char rev[20];
225 int flag;
226 struct commit *head;
227 int errs = 0;
228 int newfd;
229 struct lock_file *lock_file;
230
231 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
232 die(_("'%s' cannot be used with updating paths"), "--track");
233
234 if (opts->new_branch_log)
235 die(_("'%s' cannot be used with updating paths"), "-l");
236
237 if (opts->force && opts->patch_mode)
238 die(_("'%s' cannot be used with updating paths"), "-f");
239
240 if (opts->force_detach)
241 die(_("'%s' cannot be used with updating paths"), "--detach");
242
243 if (opts->merge && opts->patch_mode)
244 die(_("'%s' cannot be used with %s"), "--merge", "--patch");
245
246 if (opts->force && opts->merge)
247 die(_("'%s' cannot be used with %s"), "-f", "-m");
248
249 if (opts->new_branch)
250 die(_("Cannot update paths and switch to branch '%s' at the same time."),
251 opts->new_branch);
252
253 if (opts->patch_mode)
254 return run_add_interactive(revision, "--patch=checkout",
255 &opts->pathspec);
256
257 lock_file = xcalloc(1, sizeof(struct lock_file));
258
259 newfd = hold_locked_index(lock_file, 1);
260 if (read_cache_preload(&opts->pathspec) < 0)
261 return error(_("corrupt index file"));
262
263 if (opts->source_tree)
264 read_tree_some(opts->source_tree, &opts->pathspec);
265
266 ps_matched = xcalloc(1, opts->pathspec.nr);
267
268 /*
269 * Make sure all pathspecs participated in locating the paths
270 * to be checked out.
271 */
272 for (pos = 0; pos < active_nr; pos++) {
273 struct cache_entry *ce = active_cache[pos];
274 ce->ce_flags &= ~CE_MATCHED;
275 if (!opts->ignore_skipworktree && ce_skip_worktree(ce))
276 continue;
277 if (opts->source_tree && !(ce->ce_flags & CE_UPDATE))
278 /*
279 * "git checkout tree-ish -- path", but this entry
280 * is in the original index; it will not be checked
281 * out to the working tree and it does not matter
282 * if pathspec matched this entry. We will not do
283 * anything to this entry at all.
284 */
285 continue;
286 /*
287 * Either this entry came from the tree-ish we are
288 * checking the paths out of, or we are checking out
289 * of the index.
290 *
291 * If it comes from the tree-ish, we already know it
292 * matches the pathspec and could just stamp
293 * CE_MATCHED to it from update_some(). But we still
294 * need ps_matched and read_tree_recursive (and
295 * eventually tree_entry_interesting) cannot fill
296 * ps_matched yet. Once it can, we can avoid calling
297 * match_pathspec() for _all_ entries when
298 * opts->source_tree != NULL.
299 */
300 if (match_pathspec_depth(&opts->pathspec, ce->name, ce_namelen(ce),
301 0, ps_matched))
302 ce->ce_flags |= CE_MATCHED;
303 }
304
305 if (report_path_error(ps_matched, &opts->pathspec, opts->prefix)) {
306 free(ps_matched);
307 return 1;
308 }
309 free(ps_matched);
310
311 /* "checkout -m path" to recreate conflicted state */
312 if (opts->merge)
313 unmerge_marked_index(&the_index);
314
315 /* Any unmerged paths? */
316 for (pos = 0; pos < active_nr; pos++) {
317 const struct cache_entry *ce = active_cache[pos];
318 if (ce->ce_flags & CE_MATCHED) {
319 if (!ce_stage(ce))
320 continue;
321 if (opts->force) {
322 warning(_("path '%s' is unmerged"), ce->name);
323 } else if (opts->writeout_stage) {
324 errs |= check_stage(opts->writeout_stage, ce, pos);
325 } else if (opts->merge) {
326 errs |= check_stages((1<<2) | (1<<3), ce, pos);
327 } else {
328 errs = 1;
329 error(_("path '%s' is unmerged"), ce->name);
330 }
331 pos = skip_same_name(ce, pos) - 1;
332 }
333 }
334 if (errs)
335 return 1;
336
337 /* Now we are committed to check them out */
338 memset(&state, 0, sizeof(state));
339 state.force = 1;
340 state.refresh_cache = 1;
341 for (pos = 0; pos < active_nr; pos++) {
342 struct cache_entry *ce = active_cache[pos];
343 if (ce->ce_flags & CE_MATCHED) {
344 if (!ce_stage(ce)) {
345 errs |= checkout_entry(ce, &state, NULL);
346 continue;
347 }
348 if (opts->writeout_stage)
349 errs |= checkout_stage(opts->writeout_stage, ce, pos, &state);
350 else if (opts->merge)
351 errs |= checkout_merged(pos, &state);
352 pos = skip_same_name(ce, pos) - 1;
353 }
354 }
355
356 if (write_cache(newfd, active_cache, active_nr) ||
357 commit_locked_index(lock_file))
358 die(_("unable to write new index file"));
359
360 read_ref_full("HEAD", rev, 0, &flag);
361 head = lookup_commit_reference_gently(rev, 1);
362
363 errs |= post_checkout_hook(head, head, 0);
364 return errs;
365 }
366
367 static void show_local_changes(struct object *head,
368 const struct diff_options *opts)
369 {
370 struct rev_info rev;
371 /* I think we want full paths, even if we're in a subdirectory. */
372 init_revisions(&rev, NULL);
373 rev.diffopt.flags = opts->flags;
374 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
375 diff_setup_done(&rev.diffopt);
376 add_pending_object(&rev, head, NULL);
377 run_diff_index(&rev, 0);
378 }
379
380 static void describe_detached_head(const char *msg, struct commit *commit)
381 {
382 struct strbuf sb = STRBUF_INIT;
383 if (!parse_commit(commit))
384 pp_commit_easy(CMIT_FMT_ONELINE, commit, &sb);
385 fprintf(stderr, "%s %s... %s\n", msg,
386 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
387 strbuf_release(&sb);
388 }
389
390 static int reset_tree(struct tree *tree, const struct checkout_opts *o,
391 int worktree, int *writeout_error)
392 {
393 struct unpack_trees_options opts;
394 struct tree_desc tree_desc;
395
396 memset(&opts, 0, sizeof(opts));
397 opts.head_idx = -1;
398 opts.update = worktree;
399 opts.skip_unmerged = !worktree;
400 opts.reset = 1;
401 opts.merge = 1;
402 opts.fn = oneway_merge;
403 opts.verbose_update = !o->quiet && isatty(2);
404 opts.src_index = &the_index;
405 opts.dst_index = &the_index;
406 parse_tree(tree);
407 init_tree_desc(&tree_desc, tree->buffer, tree->size);
408 switch (unpack_trees(1, &tree_desc, &opts)) {
409 case -2:
410 *writeout_error = 1;
411 /*
412 * We return 0 nevertheless, as the index is all right
413 * and more importantly we have made best efforts to
414 * update paths in the work tree, and we cannot revert
415 * them.
416 */
417 case 0:
418 return 0;
419 default:
420 return 128;
421 }
422 }
423
424 struct branch_info {
425 const char *name; /* The short name used */
426 const char *path; /* The full name of a real branch */
427 struct commit *commit; /* The named commit */
428 };
429
430 static void setup_branch_path(struct branch_info *branch)
431 {
432 struct strbuf buf = STRBUF_INIT;
433
434 strbuf_branchname(&buf, branch->name);
435 if (strcmp(buf.buf, branch->name))
436 branch->name = xstrdup(buf.buf);
437 strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
438 branch->path = strbuf_detach(&buf, NULL);
439 }
440
441 static int merge_working_tree(const struct checkout_opts *opts,
442 struct branch_info *old,
443 struct branch_info *new,
444 int *writeout_error)
445 {
446 int ret;
447 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
448 int newfd = hold_locked_index(lock_file, 1);
449
450 if (read_cache_preload(NULL) < 0)
451 return error(_("corrupt index file"));
452
453 resolve_undo_clear();
454 if (opts->force) {
455 ret = reset_tree(new->commit->tree, opts, 1, writeout_error);
456 if (ret)
457 return ret;
458 } else {
459 struct tree_desc trees[2];
460 struct tree *tree;
461 struct unpack_trees_options topts;
462
463 memset(&topts, 0, sizeof(topts));
464 topts.head_idx = -1;
465 topts.src_index = &the_index;
466 topts.dst_index = &the_index;
467
468 setup_unpack_trees_porcelain(&topts, "checkout");
469
470 refresh_cache(REFRESH_QUIET);
471
472 if (unmerged_cache()) {
473 error(_("you need to resolve your current index first"));
474 return 1;
475 }
476
477 /* 2-way merge to the new branch */
478 topts.initial_checkout = is_cache_unborn();
479 topts.update = 1;
480 topts.merge = 1;
481 topts.gently = opts->merge && old->commit;
482 topts.verbose_update = !opts->quiet && isatty(2);
483 topts.fn = twoway_merge;
484 if (opts->overwrite_ignore) {
485 topts.dir = xcalloc(1, sizeof(*topts.dir));
486 topts.dir->flags |= DIR_SHOW_IGNORED;
487 setup_standard_excludes(topts.dir);
488 }
489 tree = parse_tree_indirect(old->commit ?
490 old->commit->object.sha1 :
491 EMPTY_TREE_SHA1_BIN);
492 init_tree_desc(&trees[0], tree->buffer, tree->size);
493 tree = parse_tree_indirect(new->commit->object.sha1);
494 init_tree_desc(&trees[1], tree->buffer, tree->size);
495
496 ret = unpack_trees(2, trees, &topts);
497 if (ret == -1) {
498 /*
499 * Unpack couldn't do a trivial merge; either
500 * give up or do a real merge, depending on
501 * whether the merge flag was used.
502 */
503 struct tree *result;
504 struct tree *work;
505 struct merge_options o;
506 if (!opts->merge)
507 return 1;
508
509 /*
510 * Without old->commit, the below is the same as
511 * the two-tree unpack we already tried and failed.
512 */
513 if (!old->commit)
514 return 1;
515
516 /* Do more real merge */
517
518 /*
519 * We update the index fully, then write the
520 * tree from the index, then merge the new
521 * branch with the current tree, with the old
522 * branch as the base. Then we reset the index
523 * (but not the working tree) to the new
524 * branch, leaving the working tree as the
525 * merged version, but skipping unmerged
526 * entries in the index.
527 */
528
529 add_files_to_cache(NULL, NULL, 0);
530 /*
531 * NEEDSWORK: carrying over local changes
532 * when branches have different end-of-line
533 * normalization (or clean+smudge rules) is
534 * a pain; plumb in an option to set
535 * o.renormalize?
536 */
537 init_merge_options(&o);
538 o.verbosity = 0;
539 work = write_tree_from_memory(&o);
540
541 ret = reset_tree(new->commit->tree, opts, 1,
542 writeout_error);
543 if (ret)
544 return ret;
545 o.ancestor = old->name;
546 o.branch1 = new->name;
547 o.branch2 = "local";
548 merge_trees(&o, new->commit->tree, work,
549 old->commit->tree, &result);
550 ret = reset_tree(new->commit->tree, opts, 0,
551 writeout_error);
552 if (ret)
553 return ret;
554 }
555 }
556
557 if (write_cache(newfd, active_cache, active_nr) ||
558 commit_locked_index(lock_file))
559 die(_("unable to write new index file"));
560
561 if (!opts->force && !opts->quiet)
562 show_local_changes(&new->commit->object, &opts->diff_options);
563
564 return 0;
565 }
566
567 static void report_tracking(struct branch_info *new)
568 {
569 struct strbuf sb = STRBUF_INIT;
570 struct branch *branch = branch_get(new->name);
571
572 if (!format_tracking_info(branch, &sb))
573 return;
574 fputs(sb.buf, stdout);
575 strbuf_release(&sb);
576 }
577
578 static void update_refs_for_switch(const struct checkout_opts *opts,
579 struct branch_info *old,
580 struct branch_info *new)
581 {
582 struct strbuf msg = STRBUF_INIT;
583 const char *old_desc, *reflog_msg;
584 if (opts->new_branch) {
585 if (opts->new_orphan_branch) {
586 if (opts->new_branch_log && !log_all_ref_updates) {
587 int temp;
588 char log_file[PATH_MAX];
589 char *ref_name = mkpath("refs/heads/%s", opts->new_orphan_branch);
590
591 temp = log_all_ref_updates;
592 log_all_ref_updates = 1;
593 if (log_ref_setup(ref_name, log_file, sizeof(log_file))) {
594 fprintf(stderr, _("Can not do reflog for '%s'\n"),
595 opts->new_orphan_branch);
596 log_all_ref_updates = temp;
597 return;
598 }
599 log_all_ref_updates = temp;
600 }
601 }
602 else
603 create_branch(old->name, opts->new_branch, new->name,
604 opts->new_branch_force ? 1 : 0,
605 opts->new_branch_log,
606 opts->new_branch_force ? 1 : 0,
607 opts->quiet,
608 opts->track);
609 new->name = opts->new_branch;
610 setup_branch_path(new);
611 }
612
613 old_desc = old->name;
614 if (!old_desc && old->commit)
615 old_desc = sha1_to_hex(old->commit->object.sha1);
616
617 reflog_msg = getenv("GIT_REFLOG_ACTION");
618 if (!reflog_msg)
619 strbuf_addf(&msg, "checkout: moving from %s to %s",
620 old_desc ? old_desc : "(invalid)", new->name);
621 else
622 strbuf_insert(&msg, 0, reflog_msg, strlen(reflog_msg));
623
624 if (!strcmp(new->name, "HEAD") && !new->path && !opts->force_detach) {
625 /* Nothing to do. */
626 } else if (opts->force_detach || !new->path) { /* No longer on any branch. */
627 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
628 REF_NODEREF, DIE_ON_ERR);
629 if (!opts->quiet) {
630 if (old->path && advice_detached_head)
631 detach_advice(new->name);
632 describe_detached_head(_("HEAD is now at"), new->commit);
633 }
634 } else if (new->path) { /* Switch branches. */
635 create_symref("HEAD", new->path, msg.buf);
636 if (!opts->quiet) {
637 if (old->path && !strcmp(new->path, old->path)) {
638 if (opts->new_branch_force)
639 fprintf(stderr, _("Reset branch '%s'\n"),
640 new->name);
641 else
642 fprintf(stderr, _("Already on '%s'\n"),
643 new->name);
644 } else if (opts->new_branch) {
645 if (opts->branch_exists)
646 fprintf(stderr, _("Switched to and reset branch '%s'\n"), new->name);
647 else
648 fprintf(stderr, _("Switched to a new branch '%s'\n"), new->name);
649 } else {
650 fprintf(stderr, _("Switched to branch '%s'\n"),
651 new->name);
652 }
653 }
654 if (old->path && old->name) {
655 char log_file[PATH_MAX], ref_file[PATH_MAX];
656
657 git_snpath(log_file, sizeof(log_file), "logs/%s", old->path);
658 git_snpath(ref_file, sizeof(ref_file), "%s", old->path);
659 if (!file_exists(ref_file) && file_exists(log_file))
660 remove_path(log_file);
661 }
662 }
663 remove_branch_state();
664 strbuf_release(&msg);
665 if (!opts->quiet &&
666 (new->path || (!opts->force_detach && !strcmp(new->name, "HEAD"))))
667 report_tracking(new);
668 }
669
670 static int add_pending_uninteresting_ref(const char *refname,
671 const unsigned char *sha1,
672 int flags, void *cb_data)
673 {
674 add_pending_sha1(cb_data, refname, sha1, UNINTERESTING);
675 return 0;
676 }
677
678 static void describe_one_orphan(struct strbuf *sb, struct commit *commit)
679 {
680 strbuf_addstr(sb, " ");
681 strbuf_addstr(sb,
682 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
683 strbuf_addch(sb, ' ');
684 if (!parse_commit(commit))
685 pp_commit_easy(CMIT_FMT_ONELINE, commit, sb);
686 strbuf_addch(sb, '\n');
687 }
688
689 #define ORPHAN_CUTOFF 4
690 static void suggest_reattach(struct commit *commit, struct rev_info *revs)
691 {
692 struct commit *c, *last = NULL;
693 struct strbuf sb = STRBUF_INIT;
694 int lost = 0;
695 while ((c = get_revision(revs)) != NULL) {
696 if (lost < ORPHAN_CUTOFF)
697 describe_one_orphan(&sb, c);
698 last = c;
699 lost++;
700 }
701 if (ORPHAN_CUTOFF < lost) {
702 int more = lost - ORPHAN_CUTOFF;
703 if (more == 1)
704 describe_one_orphan(&sb, last);
705 else
706 strbuf_addf(&sb, _(" ... and %d more.\n"), more);
707 }
708
709 fprintf(stderr,
710 Q_(
711 /* The singular version */
712 "Warning: you are leaving %d commit behind, "
713 "not connected to\n"
714 "any of your branches:\n\n"
715 "%s\n",
716 /* The plural version */
717 "Warning: you are leaving %d commits behind, "
718 "not connected to\n"
719 "any of your branches:\n\n"
720 "%s\n",
721 /* Give ngettext() the count */
722 lost),
723 lost,
724 sb.buf);
725 strbuf_release(&sb);
726
727 if (advice_detached_head)
728 fprintf(stderr,
729 _(
730 "If you want to keep them by creating a new branch, "
731 "this may be a good time\nto do so with:\n\n"
732 " git branch new_branch_name %s\n\n"),
733 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
734 }
735
736 /*
737 * We are about to leave commit that was at the tip of a detached
738 * HEAD. If it is not reachable from any ref, this is the last chance
739 * for the user to do so without resorting to reflog.
740 */
741 static void orphaned_commit_warning(struct commit *old, struct commit *new)
742 {
743 struct rev_info revs;
744 struct object *object = &old->object;
745 struct object_array refs;
746
747 init_revisions(&revs, NULL);
748 setup_revisions(0, NULL, &revs, NULL);
749
750 object->flags &= ~UNINTERESTING;
751 add_pending_object(&revs, object, sha1_to_hex(object->sha1));
752
753 for_each_ref(add_pending_uninteresting_ref, &revs);
754 add_pending_sha1(&revs, "HEAD", new->object.sha1, UNINTERESTING);
755
756 refs = revs.pending;
757 revs.leak_pending = 1;
758
759 if (prepare_revision_walk(&revs))
760 die(_("internal error in revision walk"));
761 if (!(old->object.flags & UNINTERESTING))
762 suggest_reattach(old, &revs);
763 else
764 describe_detached_head(_("Previous HEAD position was"), old);
765
766 clear_commit_marks_for_object_array(&refs, ALL_REV_FLAGS);
767 free(refs.objects);
768 }
769
770 static int switch_branches(const struct checkout_opts *opts,
771 struct branch_info *new)
772 {
773 int ret = 0;
774 struct branch_info old;
775 void *path_to_free;
776 unsigned char rev[20];
777 int flag, writeout_error = 0;
778 memset(&old, 0, sizeof(old));
779 old.path = path_to_free = resolve_refdup("HEAD", rev, 0, &flag);
780 old.commit = lookup_commit_reference_gently(rev, 1);
781 if (!(flag & REF_ISSYMREF))
782 old.path = NULL;
783
784 if (old.path && starts_with(old.path, "refs/heads/"))
785 old.name = old.path + strlen("refs/heads/");
786
787 if (!new->name) {
788 new->name = "HEAD";
789 new->commit = old.commit;
790 if (!new->commit)
791 die(_("You are on a branch yet to be born"));
792 parse_commit_or_die(new->commit);
793 }
794
795 ret = merge_working_tree(opts, &old, new, &writeout_error);
796 if (ret) {
797 free(path_to_free);
798 return ret;
799 }
800
801 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
802 orphaned_commit_warning(old.commit, new->commit);
803
804 update_refs_for_switch(opts, &old, new);
805
806 ret = post_checkout_hook(old.commit, new->commit, 1);
807 free(path_to_free);
808 return ret || writeout_error;
809 }
810
811 static int git_checkout_config(const char *var, const char *value, void *cb)
812 {
813 if (!strcmp(var, "diff.ignoresubmodules")) {
814 struct checkout_opts *opts = cb;
815 handle_ignore_submodules_arg(&opts->diff_options, value);
816 return 0;
817 }
818
819 if (starts_with(var, "submodule."))
820 return parse_submodule_config_option(var, value);
821
822 return git_xmerge_config(var, value, NULL);
823 }
824
825 struct tracking_name_data {
826 /* const */ char *src_ref;
827 char *dst_ref;
828 unsigned char *dst_sha1;
829 int unique;
830 };
831
832 static int check_tracking_name(struct remote *remote, void *cb_data)
833 {
834 struct tracking_name_data *cb = cb_data;
835 struct refspec query;
836 memset(&query, 0, sizeof(struct refspec));
837 query.src = cb->src_ref;
838 if (remote_find_tracking(remote, &query) ||
839 get_sha1(query.dst, cb->dst_sha1)) {
840 free(query.dst);
841 return 0;
842 }
843 if (cb->dst_ref) {
844 free(query.dst);
845 cb->unique = 0;
846 return 0;
847 }
848 cb->dst_ref = query.dst;
849 return 0;
850 }
851
852 static const char *unique_tracking_name(const char *name, unsigned char *sha1)
853 {
854 struct tracking_name_data cb_data = { NULL, NULL, NULL, 1 };
855 char src_ref[PATH_MAX];
856 snprintf(src_ref, PATH_MAX, "refs/heads/%s", name);
857 cb_data.src_ref = src_ref;
858 cb_data.dst_sha1 = sha1;
859 for_each_remote(check_tracking_name, &cb_data);
860 if (cb_data.unique)
861 return cb_data.dst_ref;
862 free(cb_data.dst_ref);
863 return NULL;
864 }
865
866 static int parse_branchname_arg(int argc, const char **argv,
867 int dwim_new_local_branch_ok,
868 struct branch_info *new,
869 struct tree **source_tree,
870 unsigned char rev[20],
871 const char **new_branch)
872 {
873 int argcount = 0;
874 unsigned char branch_rev[20];
875 const char *arg;
876 int dash_dash_pos;
877 int has_dash_dash = 0;
878 int i;
879
880 /*
881 * case 1: git checkout <ref> -- [<paths>]
882 *
883 * <ref> must be a valid tree, everything after the '--' must be
884 * a path.
885 *
886 * case 2: git checkout -- [<paths>]
887 *
888 * everything after the '--' must be paths.
889 *
890 * case 3: git checkout <something> [--]
891 *
892 * (a) If <something> is a commit, that is to
893 * switch to the branch or detach HEAD at it. As a special case,
894 * if <something> is A...B (missing A or B means HEAD but you can
895 * omit at most one side), and if there is a unique merge base
896 * between A and B, A...B names that merge base.
897 *
898 * (b) If <something> is _not_ a commit, either "--" is present
899 * or <something> is not a path, no -t nor -b was given, and
900 * and there is a tracking branch whose name is <something>
901 * in one and only one remote, then this is a short-hand to
902 * fork local <something> from that remote-tracking branch.
903 *
904 * (c) Otherwise, if "--" is present, treat it like case (1).
905 *
906 * (d) Otherwise :
907 * - if it's a reference, treat it like case (1)
908 * - else if it's a path, treat it like case (2)
909 * - else: fail.
910 *
911 * case 4: git checkout <something> <paths>
912 *
913 * The first argument must not be ambiguous.
914 * - If it's *only* a reference, treat it like case (1).
915 * - If it's only a path, treat it like case (2).
916 * - else: fail.
917 *
918 */
919 if (!argc)
920 return 0;
921
922 arg = argv[0];
923 dash_dash_pos = -1;
924 for (i = 0; i < argc; i++) {
925 if (!strcmp(argv[i], "--")) {
926 dash_dash_pos = i;
927 break;
928 }
929 }
930 if (dash_dash_pos == 0)
931 return 1; /* case (2) */
932 else if (dash_dash_pos == 1)
933 has_dash_dash = 1; /* case (3) or (1) */
934 else if (dash_dash_pos >= 2)
935 die(_("only one reference expected, %d given."), dash_dash_pos);
936
937 if (!strcmp(arg, "-"))
938 arg = "@{-1}";
939
940 if (get_sha1_mb(arg, rev)) {
941 /*
942 * Either case (3) or (4), with <something> not being
943 * a commit, or an attempt to use case (1) with an
944 * invalid ref.
945 *
946 * It's likely an error, but we need to find out if
947 * we should auto-create the branch, case (3).(b).
948 */
949 int recover_with_dwim = dwim_new_local_branch_ok;
950
951 if (check_filename(NULL, arg) && !has_dash_dash)
952 recover_with_dwim = 0;
953 /*
954 * Accept "git checkout foo" and "git checkout foo --"
955 * as candidates for dwim.
956 */
957 if (!(argc == 1 && !has_dash_dash) &&
958 !(argc == 2 && has_dash_dash))
959 recover_with_dwim = 0;
960
961 if (recover_with_dwim) {
962 const char *remote = unique_tracking_name(arg, rev);
963 if (remote) {
964 *new_branch = arg;
965 arg = remote;
966 /* DWIMmed to create local branch, case (3).(b) */
967 } else {
968 recover_with_dwim = 0;
969 }
970 }
971
972 if (!recover_with_dwim) {
973 if (has_dash_dash)
974 die(_("invalid reference: %s"), arg);
975 return argcount;
976 }
977 }
978
979 /* we can't end up being in (2) anymore, eat the argument */
980 argcount++;
981 argv++;
982 argc--;
983
984 new->name = arg;
985 setup_branch_path(new);
986
987 if (!check_refname_format(new->path, 0) &&
988 !read_ref(new->path, branch_rev))
989 hashcpy(rev, branch_rev);
990 else
991 new->path = NULL; /* not an existing branch */
992
993 new->commit = lookup_commit_reference_gently(rev, 1);
994 if (!new->commit) {
995 /* not a commit */
996 *source_tree = parse_tree_indirect(rev);
997 } else {
998 parse_commit_or_die(new->commit);
999 *source_tree = new->commit->tree;
1000 }
1001
1002 if (!*source_tree) /* case (1): want a tree */
1003 die(_("reference is not a tree: %s"), arg);
1004 if (!has_dash_dash) {/* case (3).(d) -> (1) */
1005 /*
1006 * Do not complain the most common case
1007 * git checkout branch
1008 * even if there happen to be a file called 'branch';
1009 * it would be extremely annoying.
1010 */
1011 if (argc)
1012 verify_non_filename(NULL, arg);
1013 } else {
1014 argcount++;
1015 argv++;
1016 argc--;
1017 }
1018
1019 return argcount;
1020 }
1021
1022 static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
1023 {
1024 int status;
1025 struct strbuf branch_ref = STRBUF_INIT;
1026
1027 if (!opts->new_branch)
1028 die(_("You are on a branch yet to be born"));
1029 strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
1030 status = create_symref("HEAD", branch_ref.buf, "checkout -b");
1031 strbuf_release(&branch_ref);
1032 if (!opts->quiet)
1033 fprintf(stderr, _("Switched to a new branch '%s'\n"),
1034 opts->new_branch);
1035 return status;
1036 }
1037
1038 static int checkout_branch(struct checkout_opts *opts,
1039 struct branch_info *new)
1040 {
1041 if (opts->pathspec.nr)
1042 die(_("paths cannot be used with switching branches"));
1043
1044 if (opts->patch_mode)
1045 die(_("'%s' cannot be used with switching branches"),
1046 "--patch");
1047
1048 if (opts->writeout_stage)
1049 die(_("'%s' cannot be used with switching branches"),
1050 "--ours/--theirs");
1051
1052 if (opts->force && opts->merge)
1053 die(_("'%s' cannot be used with '%s'"), "-f", "-m");
1054
1055 if (opts->force_detach && opts->new_branch)
1056 die(_("'%s' cannot be used with '%s'"),
1057 "--detach", "-b/-B/--orphan");
1058
1059 if (opts->new_orphan_branch) {
1060 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1061 die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
1062 } else if (opts->force_detach) {
1063 if (opts->track != BRANCH_TRACK_UNSPECIFIED)
1064 die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
1065 } else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
1066 opts->track = git_branch_track;
1067
1068 if (new->name && !new->commit)
1069 die(_("Cannot switch branch to a non-commit '%s'"),
1070 new->name);
1071
1072 if (!new->commit && opts->new_branch) {
1073 unsigned char rev[20];
1074 int flag;
1075
1076 if (!read_ref_full("HEAD", rev, 0, &flag) &&
1077 (flag & REF_ISSYMREF) && is_null_sha1(rev))
1078 return switch_unborn_to_new_branch(opts);
1079 }
1080 return switch_branches(opts, new);
1081 }
1082
1083 int cmd_checkout(int argc, const char **argv, const char *prefix)
1084 {
1085 struct checkout_opts opts;
1086 struct branch_info new;
1087 char *conflict_style = NULL;
1088 int dwim_new_local_branch = 1;
1089 struct option options[] = {
1090 OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
1091 OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
1092 N_("create and checkout a new branch")),
1093 OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
1094 N_("create/reset and checkout a branch")),
1095 OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
1096 OPT_BOOL(0, "detach", &opts.force_detach, N_("detach the HEAD at named commit")),
1097 OPT_SET_INT('t', "track", &opts.track, N_("set upstream info for new branch"),
1098 BRANCH_TRACK_EXPLICIT),
1099 OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new branch"), N_("new unparented branch")),
1100 OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
1101 2),
1102 OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),
1103 3),
1104 OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)")),
1105 OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
1106 OPT_BOOL(0, "overwrite-ignore", &opts.overwrite_ignore, N_("update ignored files (default)")),
1107 OPT_STRING(0, "conflict", &conflict_style, N_("style"),
1108 N_("conflict style (merge or diff3)")),
1109 OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
1110 OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
1111 N_("do not limit pathspecs to sparse entries only")),
1112 OPT_HIDDEN_BOOL(0, "guess", &dwim_new_local_branch,
1113 N_("second guess 'git checkout no-such-branch'")),
1114 OPT_END(),
1115 };
1116
1117 memset(&opts, 0, sizeof(opts));
1118 memset(&new, 0, sizeof(new));
1119 opts.overwrite_ignore = 1;
1120 opts.prefix = prefix;
1121
1122 gitmodules_config();
1123 git_config(git_checkout_config, &opts);
1124
1125 opts.track = BRANCH_TRACK_UNSPECIFIED;
1126
1127 argc = parse_options(argc, argv, prefix, options, checkout_usage,
1128 PARSE_OPT_KEEP_DASHDASH);
1129
1130 if (conflict_style) {
1131 opts.merge = 1; /* implied */
1132 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
1133 }
1134
1135 if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
1136 die(_("-b, -B and --orphan are mutually exclusive"));
1137
1138 /*
1139 * From here on, new_branch will contain the branch to be checked out,
1140 * and new_branch_force and new_orphan_branch will tell us which one of
1141 * -b/-B/--orphan is being used.
1142 */
1143 if (opts.new_branch_force)
1144 opts.new_branch = opts.new_branch_force;
1145
1146 if (opts.new_orphan_branch)
1147 opts.new_branch = opts.new_orphan_branch;
1148
1149 /* --track without -b/-B/--orphan should DWIM */
1150 if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
1151 const char *argv0 = argv[0];
1152 if (!argc || !strcmp(argv0, "--"))
1153 die (_("--track needs a branch name"));
1154 if (starts_with(argv0, "refs/"))
1155 argv0 += 5;
1156 if (starts_with(argv0, "remotes/"))
1157 argv0 += 8;
1158 argv0 = strchr(argv0, '/');
1159 if (!argv0 || !argv0[1])
1160 die (_("Missing branch name; try -b"));
1161 opts.new_branch = argv0 + 1;
1162 }
1163
1164 /*
1165 * Extract branch name from command line arguments, so
1166 * all that is left is pathspecs.
1167 *
1168 * Handle
1169 *
1170 * 1) git checkout <tree> -- [<paths>]
1171 * 2) git checkout -- [<paths>]
1172 * 3) git checkout <something> [<paths>]
1173 *
1174 * including "last branch" syntax and DWIM-ery for names of
1175 * remote branches, erroring out for invalid or ambiguous cases.
1176 */
1177 if (argc) {
1178 unsigned char rev[20];
1179 int dwim_ok =
1180 !opts.patch_mode &&
1181 dwim_new_local_branch &&
1182 opts.track == BRANCH_TRACK_UNSPECIFIED &&
1183 !opts.new_branch;
1184 int n = parse_branchname_arg(argc, argv, dwim_ok,
1185 &new, &opts.source_tree,
1186 rev, &opts.new_branch);
1187 argv += n;
1188 argc -= n;
1189 }
1190
1191 if (argc) {
1192 parse_pathspec(&opts.pathspec, 0,
1193 opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
1194 prefix, argv);
1195
1196 if (!opts.pathspec.nr)
1197 die(_("invalid path specification"));
1198
1199 /*
1200 * Try to give more helpful suggestion.
1201 * new_branch && argc > 1 will be caught later.
1202 */
1203 if (opts.new_branch && argc == 1)
1204 die(_("Cannot update paths and switch to branch '%s' at the same time.\n"
1205 "Did you intend to checkout '%s' which can not be resolved as commit?"),
1206 opts.new_branch, argv[0]);
1207
1208 if (opts.force_detach)
1209 die(_("git checkout: --detach does not take a path argument '%s'"),
1210 argv[0]);
1211
1212 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
1213 die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
1214 "checking out of the index."));
1215 }
1216
1217 if (opts.new_branch) {
1218 struct strbuf buf = STRBUF_INIT;
1219
1220 opts.branch_exists =
1221 validate_new_branchname(opts.new_branch, &buf,
1222 !!opts.new_branch_force,
1223 !!opts.new_branch_force);
1224
1225 strbuf_release(&buf);
1226 }
1227
1228 if (opts.patch_mode || opts.pathspec.nr)
1229 return checkout_paths(&opts, new.name);
1230 else
1231 return checkout_branch(&opts, &new);
1232 }