checkout -m path: fix recreating conflicts
[git/git.git] / builtin-checkout.c
CommitLineData
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1#include "cache.h"
2#include "builtin.h"
3#include "parse-options.h"
4#include "refs.h"
5#include "commit.h"
6#include "tree.h"
7#include "tree-walk.h"
8#include "unpack-trees.h"
9#include "dir.h"
10#include "run-command.h"
11#include "merge-recursive.h"
12#include "branch.h"
13#include "diff.h"
14#include "revision.h"
79a1e6b4 15#include "remote.h"
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16#include "blob.h"
17#include "xdiff-interface.h"
18#include "ll-merge.h"
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19
20static const char * const checkout_usage[] = {
21 "git checkout [options] <branch>",
22 "git checkout [options] [<branch>] -- <file>...",
23 NULL,
24};
25
db941099
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26struct checkout_opts {
27 int quiet;
28 int merge;
29 int force;
38901a48 30 int writeout_stage;
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31 int writeout_error;
32
33 const char *new_branch;
34 int new_branch_log;
35 enum branch_track track;
36};
37
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38static int post_checkout_hook(struct commit *old, struct commit *new,
39 int changed)
40{
41 struct child_process proc;
42 const char *name = git_path("hooks/post-checkout");
43 const char *argv[5];
44
45 if (access(name, X_OK) < 0)
46 return 0;
47
48 memset(&proc, 0, sizeof(proc));
49 argv[0] = name;
323e00fd 50 argv[1] = xstrdup(sha1_to_hex(old ? old->object.sha1 : null_sha1));
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51 argv[2] = xstrdup(sha1_to_hex(new->object.sha1));
52 argv[3] = changed ? "1" : "0";
53 argv[4] = NULL;
54 proc.argv = argv;
55 proc.no_stdin = 1;
56 proc.stdout_to_stderr = 1;
57 return run_command(&proc);
58}
59
60static int update_some(const unsigned char *sha1, const char *base, int baselen,
671f0707 61 const char *pathname, unsigned mode, int stage, void *context)
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DB
62{
63 int len;
64 struct cache_entry *ce;
65
66 if (S_ISGITLINK(mode))
67 return 0;
68
69 if (S_ISDIR(mode))
70 return READ_TREE_RECURSIVE;
71
72 len = baselen + strlen(pathname);
73 ce = xcalloc(1, cache_entry_size(len));
74 hashcpy(ce->sha1, sha1);
75 memcpy(ce->name, base, baselen);
76 memcpy(ce->name + baselen, pathname, len - baselen);
77 ce->ce_flags = create_ce_flags(len, 0);
78 ce->ce_mode = create_ce_mode(mode);
79 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
80 return 0;
81}
82
83static int read_tree_some(struct tree *tree, const char **pathspec)
84{
671f0707 85 read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
782c2d65 86
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87 /* update the index with the given tree's info
88 * for all args, expanding wildcards, and exit
89 * with any non-zero return code.
90 */
91 return 0;
92}
93
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94static int skip_same_name(struct cache_entry *ce, int pos)
95{
96 while (++pos < active_nr &&
97 !strcmp(active_cache[pos]->name, ce->name))
98 ; /* skip */
99 return pos;
100}
101
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102static int check_stage(int stage, struct cache_entry *ce, int pos)
103{
104 while (pos < active_nr &&
105 !strcmp(active_cache[pos]->name, ce->name)) {
106 if (ce_stage(active_cache[pos]) == stage)
107 return 0;
108 pos++;
109 }
110 return error("path '%s' does not have %s version",
111 ce->name,
112 (stage == 2) ? "our" : "their");
113}
114
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115static int check_all_stages(struct cache_entry *ce, int pos)
116{
117 if (ce_stage(ce) != 1 ||
118 active_nr <= pos + 2 ||
119 strcmp(active_cache[pos+1]->name, ce->name) ||
120 ce_stage(active_cache[pos+1]) != 2 ||
121 strcmp(active_cache[pos+2]->name, ce->name) ||
122 ce_stage(active_cache[pos+2]) != 3)
123 return error("path '%s' does not have all three versions",
124 ce->name);
125 return 0;
126}
127
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128static int checkout_stage(int stage, struct cache_entry *ce, int pos,
129 struct checkout *state)
130{
131 while (pos < active_nr &&
132 !strcmp(active_cache[pos]->name, ce->name)) {
133 if (ce_stage(active_cache[pos]) == stage)
134 return checkout_entry(active_cache[pos], state, NULL);
135 pos++;
136 }
137 return error("path '%s' does not have %s version",
138 ce->name,
139 (stage == 2) ? "our" : "their");
140}
8fdcf312 141
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142/* NEEDSWORK: share with merge-recursive */
143static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
144{
145 unsigned long size;
146 enum object_type type;
147
148 if (!hashcmp(sha1, null_sha1)) {
149 mm->ptr = xstrdup("");
150 mm->size = 0;
151 return;
152 }
153
154 mm->ptr = read_sha1_file(sha1, &type, &size);
155 if (!mm->ptr || type != OBJ_BLOB)
156 die("unable to read blob object %s", sha1_to_hex(sha1));
157 mm->size = size;
158}
159
160static int checkout_merged(int pos, struct checkout *state)
161{
162 struct cache_entry *ce = active_cache[pos];
163 const char *path = ce->name;
164 mmfile_t ancestor, ours, theirs;
165 int status;
166 unsigned char sha1[20];
167 mmbuffer_t result_buf;
168
169 if (ce_stage(ce) != 1 ||
170 active_nr <= pos + 2 ||
171 strcmp(active_cache[pos+1]->name, path) ||
172 ce_stage(active_cache[pos+1]) != 2 ||
173 strcmp(active_cache[pos+2]->name, path) ||
174 ce_stage(active_cache[pos+2]) != 3)
175 return error("path '%s' does not have all 3 versions", path);
176
177 fill_mm(active_cache[pos]->sha1, &ancestor);
178 fill_mm(active_cache[pos+1]->sha1, &ours);
179 fill_mm(active_cache[pos+2]->sha1, &theirs);
180
181 status = ll_merge(&result_buf, path, &ancestor,
6d6f9acc 182 &ours, "ours", &theirs, "theirs", 0);
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183 free(ancestor.ptr);
184 free(ours.ptr);
185 free(theirs.ptr);
186 if (status < 0 || !result_buf.ptr) {
187 free(result_buf.ptr);
188 return error("path '%s': cannot merge", path);
189 }
190
191 /*
192 * NEEDSWORK:
193 * There is absolutely no reason to write this as a blob object
194 * and create a phoney cache entry just to leak. This hack is
195 * primarily to get to the write_entry() machinery that massages
196 * the contents to work-tree format and writes out which only
197 * allows it for a cache entry. The code in write_entry() needs
198 * to be refactored to allow us to feed a <buffer, size, mode>
199 * instead of a cache entry. Such a refactoring would help
200 * merge_recursive as well (it also writes the merge result to the
201 * object database even when it may contain conflicts).
202 */
203 if (write_sha1_file(result_buf.ptr, result_buf.size,
204 blob_type, sha1))
205 die("Unable to add merge result for '%s'", path);
206 ce = make_cache_entry(create_ce_mode(active_cache[pos+1]->ce_mode),
207 sha1,
208 path, 2, 0);
048f2762
DP
209 if (!ce)
210 die("make_cache_entry failed for path '%s'", path);
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211 status = checkout_entry(ce, state, NULL);
212 return status;
213}
8fdcf312 214
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215static int checkout_paths(struct tree *source_tree, const char **pathspec,
216 struct checkout_opts *opts)
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217{
218 int pos;
219 struct checkout state;
220 static char *ps_matched;
221 unsigned char rev[20];
222 int flag;
223 struct commit *head;
d2b3691b 224 int errs = 0;
38901a48 225 int stage = opts->writeout_stage;
0cf8581e 226 int merge = opts->merge;
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227 int newfd;
228 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
229
230 newfd = hold_locked_index(lock_file, 1);
231 read_cache();
232
233 if (source_tree)
234 read_tree_some(source_tree, pathspec);
235
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236 for (pos = 0; pathspec[pos]; pos++)
237 ;
238 ps_matched = xcalloc(1, pos);
239
240 for (pos = 0; pos < active_nr; pos++) {
241 struct cache_entry *ce = active_cache[pos];
242 pathspec_match(pathspec, ps_matched, ce->name, 0);
243 }
244
245 if (report_path_error(ps_matched, pathspec, 0))
246 return 1;
247
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248 /* Any unmerged paths? */
249 for (pos = 0; pos < active_nr; pos++) {
250 struct cache_entry *ce = active_cache[pos];
251 if (pathspec_match(pathspec, NULL, ce->name, 0)) {
252 if (!ce_stage(ce))
253 continue;
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254 if (opts->force) {
255 warning("path '%s' is unmerged", ce->name);
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256 } else if (stage) {
257 errs |= check_stage(stage, ce, pos);
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258 } else if (opts->merge) {
259 errs |= check_all_stages(ce, pos);
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260 } else {
261 errs = 1;
262 error("path '%s' is unmerged", ce->name);
263 }
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264 pos = skip_same_name(ce, pos) - 1;
265 }
266 }
267 if (errs)
268 return 1;
269
d2b3691b 270 /* Now we are committed to check them out */
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271 memset(&state, 0, sizeof(state));
272 state.force = 1;
273 state.refresh_cache = 1;
274 for (pos = 0; pos < active_nr; pos++) {
275 struct cache_entry *ce = active_cache[pos];
276 if (pathspec_match(pathspec, NULL, ce->name, 0)) {
8fdcf312
JH
277 if (!ce_stage(ce)) {
278 errs |= checkout_entry(ce, &state, NULL);
279 continue;
280 }
38901a48
JH
281 if (stage)
282 errs |= checkout_stage(stage, ce, pos, &state);
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283 else if (merge)
284 errs |= checkout_merged(pos, &state);
8fdcf312 285 pos = skip_same_name(ce, pos) - 1;
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DB
286 }
287 }
288
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DB
289 if (write_cache(newfd, active_cache, active_nr) ||
290 commit_locked_index(lock_file))
291 die("unable to write new index file");
292
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293 resolve_ref("HEAD", rev, 0, &flag);
294 head = lookup_commit_reference_gently(rev, 1);
295
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296 errs |= post_checkout_hook(head, head, 0);
297 return errs;
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298}
299
300static void show_local_changes(struct object *head)
301{
302 struct rev_info rev;
303 /* I think we want full paths, even if we're in a subdirectory. */
304 init_revisions(&rev, NULL);
305 rev.abbrev = 0;
306 rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
307 add_pending_object(&rev, head, NULL);
308 run_diff_index(&rev, 0);
309}
310
311static void describe_detached_head(char *msg, struct commit *commit)
312{
f285a2d7 313 struct strbuf sb = STRBUF_INIT;
782c2d65 314 parse_commit(commit);
27886318 315 pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
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DB
316 fprintf(stderr, "%s %s... %s\n", msg,
317 find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
318 strbuf_release(&sb);
319}
320
6286a08d 321static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
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DB
322{
323 struct unpack_trees_options opts;
324 struct tree_desc tree_desc;
bc052d7f 325
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326 memset(&opts, 0, sizeof(opts));
327 opts.head_idx = -1;
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328 opts.update = worktree;
329 opts.skip_unmerged = !worktree;
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330 opts.reset = 1;
331 opts.merge = 1;
332 opts.fn = oneway_merge;
6286a08d 333 opts.verbose_update = !o->quiet;
34110cd4
LT
334 opts.src_index = &the_index;
335 opts.dst_index = &the_index;
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DB
336 parse_tree(tree);
337 init_tree_desc(&tree_desc, tree->buffer, tree->size);
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338 switch (unpack_trees(1, &tree_desc, &opts)) {
339 case -2:
340 o->writeout_error = 1;
341 /*
342 * We return 0 nevertheless, as the index is all right
343 * and more importantly we have made best efforts to
344 * update paths in the work tree, and we cannot revert
345 * them.
346 */
347 case 0:
348 return 0;
349 default:
84a5750b 350 return 128;
291d823e 351 }
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352}
353
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354struct branch_info {
355 const char *name; /* The short name used */
356 const char *path; /* The full name of a real branch */
357 struct commit *commit; /* The named commit */
358};
359
360static void setup_branch_path(struct branch_info *branch)
361{
f285a2d7 362 struct strbuf buf = STRBUF_INIT;
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363 strbuf_addstr(&buf, "refs/heads/");
364 strbuf_addstr(&buf, branch->name);
365 branch->path = strbuf_detach(&buf, NULL);
366}
367
368static int merge_working_tree(struct checkout_opts *opts,
75ea38df 369 struct branch_info *old, struct branch_info *new)
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370{
371 int ret;
372 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
373 int newfd = hold_locked_index(lock_file, 1);
374 read_cache();
375
376 if (opts->force) {
6286a08d 377 ret = reset_tree(new->commit->tree, opts, 1);
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DB
378 if (ret)
379 return ret;
380 } else {
381 struct tree_desc trees[2];
382 struct tree *tree;
383 struct unpack_trees_options topts;
bc052d7f 384
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DB
385 memset(&topts, 0, sizeof(topts));
386 topts.head_idx = -1;
34110cd4
LT
387 topts.src_index = &the_index;
388 topts.dst_index = &the_index;
782c2d65 389
8ccba008
JH
390 topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
391
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DB
392 refresh_cache(REFRESH_QUIET);
393
394 if (unmerged_cache()) {
04c9e11f
JH
395 error("you need to resolve your current index first");
396 return 1;
782c2d65 397 }
04c9e11f
JH
398
399 /* 2-way merge to the new branch */
fa7b3c2f 400 topts.initial_checkout = is_cache_unborn();
04c9e11f
JH
401 topts.update = 1;
402 topts.merge = 1;
403 topts.gently = opts->merge;
404 topts.verbose_update = !opts->quiet;
405 topts.fn = twoway_merge;
406 topts.dir = xcalloc(1, sizeof(*topts.dir));
407 topts.dir->show_ignored = 1;
408 topts.dir->exclude_per_dir = ".gitignore";
409 tree = parse_tree_indirect(old->commit->object.sha1);
410 init_tree_desc(&trees[0], tree->buffer, tree->size);
411 tree = parse_tree_indirect(new->commit->object.sha1);
412 init_tree_desc(&trees[1], tree->buffer, tree->size);
413
291d823e
JH
414 ret = unpack_trees(2, trees, &topts);
415 if (ret == -1) {
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DB
416 /*
417 * Unpack couldn't do a trivial merge; either
418 * give up or do a real merge, depending on
419 * whether the merge flag was used.
420 */
421 struct tree *result;
422 struct tree *work;
8a2fce18 423 struct merge_options o;
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DB
424 if (!opts->merge)
425 return 1;
426 parse_commit(old->commit);
427
428 /* Do more real merge */
429
430 /*
431 * We update the index fully, then write the
432 * tree from the index, then merge the new
433 * branch with the current tree, with the old
434 * branch as the base. Then we reset the index
435 * (but not the working tree) to the new
436 * branch, leaving the working tree as the
437 * merged version, but skipping unmerged
438 * entries in the index.
439 */
440
7ae02a30 441 add_files_to_cache(NULL, NULL, 0);
8a2fce18
MV
442 init_merge_options(&o);
443 o.verbosity = 0;
444 work = write_tree_from_memory(&o);
782c2d65 445
6286a08d 446 ret = reset_tree(new->commit->tree, opts, 1);
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DB
447 if (ret)
448 return ret;
8a2fce18
MV
449 o.branch1 = new->name;
450 o.branch2 = "local";
451 merge_trees(&o, new->commit->tree, work,
452 old->commit->tree, &result);
6286a08d 453 ret = reset_tree(new->commit->tree, opts, 0);
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JH
454 if (ret)
455 return ret;
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DB
456 }
457 }
458
459 if (write_cache(newfd, active_cache, active_nr) ||
460 commit_locked_index(lock_file))
461 die("unable to write new index file");
462
7fe4a728 463 if (!opts->force && !opts->quiet)
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464 show_local_changes(&new->commit->object);
465
466 return 0;
467}
468
6d21bf96 469static void report_tracking(struct branch_info *new)
79a1e6b4 470{
6d21bf96 471 struct strbuf sb = STRBUF_INIT;
b56fca07 472 struct branch *branch = branch_get(new->name);
79a1e6b4 473
6d21bf96 474 if (!format_tracking_info(branch, &sb))
79a1e6b4 475 return;
6d21bf96
JH
476 fputs(sb.buf, stdout);
477 strbuf_release(&sb);
b0030db3 478}
79a1e6b4 479
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DB
480static void update_refs_for_switch(struct checkout_opts *opts,
481 struct branch_info *old,
482 struct branch_info *new)
483{
f285a2d7 484 struct strbuf msg = STRBUF_INIT;
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DB
485 const char *old_desc;
486 if (opts->new_branch) {
487 create_branch(old->name, opts->new_branch, new->name, 0,
488 opts->new_branch_log, opts->track);
489 new->name = opts->new_branch;
490 setup_branch_path(new);
491 }
492
782c2d65 493 old_desc = old->name;
323e00fd 494 if (!old_desc && old->commit)
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DB
495 old_desc = sha1_to_hex(old->commit->object.sha1);
496 strbuf_addf(&msg, "checkout: moving from %s to %s",
323e00fd 497 old_desc ? old_desc : "(invalid)", new->name);
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DB
498
499 if (new->path) {
500 create_symref("HEAD", new->path, msg.buf);
501 if (!opts->quiet) {
502 if (old->path && !strcmp(new->path, old->path))
503 fprintf(stderr, "Already on \"%s\"\n",
504 new->name);
505 else
506 fprintf(stderr, "Switched to%s branch \"%s\"\n",
507 opts->new_branch ? " a new" : "",
508 new->name);
509 }
510 } else if (strcmp(new->name, "HEAD")) {
511 update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
512 REF_NODEREF, DIE_ON_ERR);
513 if (!opts->quiet) {
514 if (old->path)
515 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);
516 describe_detached_head("HEAD is now at", new->commit);
517 }
518 }
519 remove_branch_state();
520 strbuf_release(&msg);
b0030db3 521 if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
6d21bf96 522 report_tracking(new);
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DB
523}
524
75ea38df 525static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
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DB
526{
527 int ret = 0;
528 struct branch_info old;
529 unsigned char rev[20];
530 int flag;
531 memset(&old, 0, sizeof(old));
532 old.path = resolve_ref("HEAD", rev, 0, &flag);
533 old.commit = lookup_commit_reference_gently(rev, 1);
534 if (!(flag & REF_ISSYMREF))
535 old.path = NULL;
536
537 if (old.path && !prefixcmp(old.path, "refs/heads/"))
538 old.name = old.path + strlen("refs/heads/");
539
540 if (!new->name) {
541 new->name = "HEAD";
542 new->commit = old.commit;
543 if (!new->commit)
544 die("You are on a branch yet to be born");
545 parse_commit(new->commit);
546 }
547
548 /*
bea005e2
JK
549 * If we were on a detached HEAD, but we are now moving to
550 * a new commit, we want to mention the old commit once more
551 * to remind the user that it might be lost.
782c2d65 552 */
323e00fd 553 if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
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DB
554 describe_detached_head("Previous HEAD position was", old.commit);
555
1510dbe3 556 if (!old.commit && !opts->force) {
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DB
557 if (!opts->quiet) {
558 fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
559 fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
560 }
561 opts->force = 1;
562 }
563
75ea38df 564 ret = merge_working_tree(opts, &old, new);
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DB
565 if (ret)
566 return ret;
567
568 update_refs_for_switch(opts, &old, new);
569
291d823e
JH
570 ret = post_checkout_hook(old.commit, new->commit, 1);
571 return ret || opts->writeout_error;
782c2d65
DB
572}
573
0cf8581e
JH
574static int git_checkout_config(const char *var, const char *value, void *cb)
575{
576 return git_xmerge_config(var, value, cb);
577}
578
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DB
579int cmd_checkout(int argc, const char **argv, const char *prefix)
580{
581 struct checkout_opts opts;
582 unsigned char rev[20];
583 const char *arg;
584 struct branch_info new;
585 struct tree *source_tree = NULL;
eac5a401 586 char *conflict_style = NULL;
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DB
587 struct option options[] = {
588 OPT__QUIET(&opts.quiet),
589 OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
590 OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
498a6e7e 591 OPT_SET_INT('t', "track", &opts.track, "track",
9ed36cfa 592 BRANCH_TRACK_EXPLICIT),
38901a48
JH
593 OPT_SET_INT('2', "ours", &opts.writeout_stage, "stage",
594 2),
595 OPT_SET_INT('3', "theirs", &opts.writeout_stage, "stage",
596 3),
782c2d65 597 OPT_BOOLEAN('f', NULL, &opts.force, "force"),
eac5a401
JH
598 OPT_BOOLEAN('m', "merge", &opts.merge, "merge"),
599 OPT_STRING(0, "conflict", &conflict_style, "style",
600 "conflict style (merge or diff3)"),
b249b552 601 OPT_END(),
782c2d65 602 };
859fdaba 603 int has_dash_dash;
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DB
604
605 memset(&opts, 0, sizeof(opts));
606 memset(&new, 0, sizeof(new));
607
0cf8581e 608 git_config(git_checkout_config, NULL);
782c2d65 609
9188ed89 610 opts.track = BRANCH_TRACK_UNSPECIFIED;
782c2d65 611
f5242ebf
PH
612 argc = parse_options(argc, argv, options, checkout_usage,
613 PARSE_OPT_KEEP_DASHDASH);
859fdaba 614
bb0ceb62 615 /* --track without -b should DWIM */
9188ed89
AR
616 if (0 < opts.track && !opts.new_branch) {
617 const char *argv0 = argv[0];
618 if (!argc || !strcmp(argv0, "--"))
bb0ceb62 619 die ("--track needs a branch name");
9188ed89
AR
620 if (!prefixcmp(argv0, "refs/"))
621 argv0 += 5;
622 if (!prefixcmp(argv0, "remotes/"))
623 argv0 += 8;
624 argv0 = strchr(argv0, '/');
625 if (!argv0 || !argv0[1])
bb0ceb62 626 die ("Missing branch name; try -b");
9188ed89 627 opts.new_branch = argv0 + 1;
bb0ceb62
JS
628 }
629
9188ed89 630 if (opts.track == BRANCH_TRACK_UNSPECIFIED)
bb0ceb62 631 opts.track = git_branch_track;
eac5a401
JH
632 if (conflict_style) {
633 opts.merge = 1; /* implied */
634 git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
635 }
636
859fdaba
PH
637 if (opts.force && opts.merge)
638 die("git checkout: -f and -m are incompatible");
639
640 /*
641 * case 1: git checkout <ref> -- [<paths>]
642 *
643 * <ref> must be a valid tree, everything after the '--' must be
644 * a path.
645 *
646 * case 2: git checkout -- [<paths>]
647 *
648 * everything after the '--' must be paths.
649 *
650 * case 3: git checkout <something> [<paths>]
651 *
652 * With no paths, if <something> is a commit, that is to
653 * switch to the branch or detach HEAD at it.
654 *
655 * Otherwise <something> shall not be ambiguous.
656 * - If it's *only* a reference, treat it like case (1).
657 * - If it's only a path, treat it like case (2).
658 * - else: fail.
659 *
660 */
782c2d65 661 if (argc) {
859fdaba
PH
662 if (!strcmp(argv[0], "--")) { /* case (2) */
663 argv++;
664 argc--;
665 goto no_reference;
666 }
667
782c2d65 668 arg = argv[0];
859fdaba
PH
669 has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
670
671 if (get_sha1(arg, rev)) {
672 if (has_dash_dash) /* case (1) */
673 die("invalid reference: %s", arg);
674 goto no_reference; /* case (3 -> 2) */
675 }
676
677 /* we can't end up being in (2) anymore, eat the argument */
678 argv++;
679 argc--;
680
681 if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
782c2d65
DB
682 new.name = arg;
683 setup_branch_path(&new);
684 if (resolve_ref(new.path, rev, 1, NULL))
685 new.commit = lookup_commit_reference(rev);
686 else
687 new.path = NULL;
688 parse_commit(new.commit);
689 source_tree = new.commit->tree;
859fdaba
PH
690 } else
691 source_tree = parse_tree_indirect(rev);
692
693 if (!source_tree) /* case (1): want a tree */
694 die("reference is not a tree: %s", arg);
695 if (!has_dash_dash) {/* case (3 -> 1) */
696 /*
697 * Do not complain the most common case
698 * git checkout branch
699 * even if there happen to be a file called 'branch';
700 * it would be extremely annoying.
701 */
702 if (argc)
703 verify_non_filename(NULL, arg);
704 }
705 else {
782c2d65
DB
706 argv++;
707 argc--;
708 }
709 }
710
859fdaba 711no_reference:
782c2d65
DB
712 if (argc) {
713 const char **pathspec = get_pathspec(prefix, argv);
301e42ed
AR
714
715 if (!pathspec)
716 die("invalid path specification");
717
782c2d65 718 /* Checkout paths */
0cf8581e 719 if (opts.new_branch) {
782c2d65 720 if (argc == 1) {
db941099 721 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]);
782c2d65 722 } else {
db941099 723 die("git checkout: updating paths is incompatible with switching branches.");
782c2d65
DB
724 }
725 }
726
0cf8581e
JH
727 if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
728 die("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index.");
729
db941099 730 return checkout_paths(source_tree, pathspec, &opts);
782c2d65
DB
731 }
732
352eadc4 733 if (opts.new_branch) {
f285a2d7 734 struct strbuf buf = STRBUF_INIT;
352eadc4
DB
735 strbuf_addstr(&buf, "refs/heads/");
736 strbuf_addstr(&buf, opts.new_branch);
737 if (!get_sha1(buf.buf, rev))
738 die("git checkout: branch %s already exists", opts.new_branch);
739 if (check_ref_format(buf.buf))
740 die("git checkout: we do not like '%s' as a branch name.", opts.new_branch);
741 strbuf_release(&buf);
742 }
743
782c2d65
DB
744 if (new.name && !new.commit) {
745 die("Cannot switch branch to a non-commit.");
746 }
38901a48
JH
747 if (opts.writeout_stage)
748 die("--ours/--theirs is incompatible with switching branches.");
782c2d65 749
75ea38df 750 return switch_branches(&opts, &new);
782c2d65 751}