gitweb: Quote non-displayable characters in hex, not octal
[git/repo.git] / builtin-merge.c
blob5c65a5869900ad1a1014fb3aad88c874a5410bf7
1 /*
2 * Builtin "git merge"
4 * Copyright (c) 2008 Miklos Vajna <vmiklos@frugalware.org>
6 * Based on git-merge.sh by Junio C Hamano.
7 */
9 #include "cache.h"
10 #include "parse-options.h"
11 #include "builtin.h"
12 #include "run-command.h"
13 #include "diff.h"
14 #include "refs.h"
15 #include "commit.h"
16 #include "diffcore.h"
17 #include "revision.h"
18 #include "unpack-trees.h"
19 #include "cache-tree.h"
20 #include "dir.h"
21 #include "utf8.h"
22 #include "log-tree.h"
23 #include "color.h"
24 #include "rerere.h"
25 #include "help.h"
26 #include "merge-recursive.h"
28 #define DEFAULT_TWOHEAD (1<<0)
29 #define DEFAULT_OCTOPUS (1<<1)
30 #define NO_FAST_FORWARD (1<<2)
31 #define NO_TRIVIAL (1<<3)
33 struct strategy {
34 const char *name;
35 unsigned attr;
38 static const char * const builtin_merge_usage[] = {
39 "git-merge [options] <remote>...",
40 "git-merge [options] <msg> HEAD <remote>",
41 NULL
44 static int show_diffstat = 1, option_log, squash;
45 static int option_commit = 1, allow_fast_forward = 1;
46 static int allow_trivial = 1, have_message;
47 static struct strbuf merge_msg;
48 static struct commit_list *remoteheads;
49 static unsigned char head[20], stash[20];
50 static struct strategy **use_strategies;
51 static size_t use_strategies_nr, use_strategies_alloc;
52 static const char *branch;
54 static struct strategy all_strategy[] = {
55 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
56 { "octopus", DEFAULT_OCTOPUS },
57 { "resolve", 0 },
58 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
59 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
62 static const char *pull_twohead, *pull_octopus;
64 static int option_parse_message(const struct option *opt,
65 const char *arg, int unset)
67 struct strbuf *buf = opt->value;
69 if (unset)
70 strbuf_setlen(buf, 0);
71 else if (arg) {
72 strbuf_addf(buf, "%s\n\n", arg);
73 have_message = 1;
74 } else
75 return error("switch `m' requires a value");
76 return 0;
79 static struct strategy *get_strategy(const char *name)
81 int i;
82 struct strategy *ret;
83 static struct cmdnames main_cmds, other_cmds;
84 static int loaded;
86 if (!name)
87 return NULL;
89 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
90 if (!strcmp(name, all_strategy[i].name))
91 return &all_strategy[i];
93 if (!loaded) {
94 struct cmdnames not_strategies;
95 loaded = 1;
97 memset(&not_strategies, 0, sizeof(struct cmdnames));
98 load_command_list("git-merge-", &main_cmds, &other_cmds);
99 for (i = 0; i < main_cmds.cnt; i++) {
100 int j, found = 0;
101 struct cmdname *ent = main_cmds.names[i];
102 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
103 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
104 && !all_strategy[j].name[ent->len])
105 found = 1;
106 if (!found)
107 add_cmdname(&not_strategies, ent->name, ent->len);
108 exclude_cmds(&main_cmds, &not_strategies);
111 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
112 fprintf(stderr, "Could not find merge strategy '%s'.\n", name);
113 fprintf(stderr, "Available strategies are:");
114 for (i = 0; i < main_cmds.cnt; i++)
115 fprintf(stderr, " %s", main_cmds.names[i]->name);
116 fprintf(stderr, ".\n");
117 if (other_cmds.cnt) {
118 fprintf(stderr, "Available custom strategies are:");
119 for (i = 0; i < other_cmds.cnt; i++)
120 fprintf(stderr, " %s", other_cmds.names[i]->name);
121 fprintf(stderr, ".\n");
123 exit(1);
126 ret = xmalloc(sizeof(struct strategy));
127 memset(ret, 0, sizeof(struct strategy));
128 ret->name = xstrdup(name);
129 return ret;
132 static void append_strategy(struct strategy *s)
134 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
135 use_strategies[use_strategies_nr++] = s;
138 static int option_parse_strategy(const struct option *opt,
139 const char *name, int unset)
141 if (unset)
142 return 0;
144 append_strategy(get_strategy(name));
145 return 0;
148 static int option_parse_n(const struct option *opt,
149 const char *arg, int unset)
151 show_diffstat = unset;
152 return 0;
155 static struct option builtin_merge_options[] = {
156 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
157 "do not show a diffstat at the end of the merge",
158 PARSE_OPT_NOARG, option_parse_n },
159 OPT_BOOLEAN(0, "stat", &show_diffstat,
160 "show a diffstat at the end of the merge"),
161 OPT_BOOLEAN(0, "summary", &show_diffstat, "(synonym to --stat)"),
162 OPT_BOOLEAN(0, "log", &option_log,
163 "add list of one-line log to merge commit message"),
164 OPT_BOOLEAN(0, "squash", &squash,
165 "create a single commit instead of doing a merge"),
166 OPT_BOOLEAN(0, "commit", &option_commit,
167 "perform a commit if the merge succeeds (default)"),
168 OPT_BOOLEAN(0, "ff", &allow_fast_forward,
169 "allow fast forward (default)"),
170 OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
171 "merge strategy to use", option_parse_strategy),
172 OPT_CALLBACK('m', "message", &merge_msg, "message",
173 "message to be used for the merge commit (if any)",
174 option_parse_message),
175 OPT_END()
178 /* Cleans up metadata that is uninteresting after a succeeded merge. */
179 static void drop_save(void)
181 unlink(git_path("MERGE_HEAD"));
182 unlink(git_path("MERGE_MSG"));
185 static void save_state(void)
187 int len;
188 struct child_process cp;
189 struct strbuf buffer = STRBUF_INIT;
190 const char *argv[] = {"stash", "create", NULL};
192 memset(&cp, 0, sizeof(cp));
193 cp.argv = argv;
194 cp.out = -1;
195 cp.git_cmd = 1;
197 if (start_command(&cp))
198 die("could not run stash.");
199 len = strbuf_read(&buffer, cp.out, 1024);
200 close(cp.out);
202 if (finish_command(&cp) || len < 0)
203 die("stash failed");
204 else if (!len)
205 return;
206 strbuf_setlen(&buffer, buffer.len-1);
207 if (get_sha1(buffer.buf, stash))
208 die("not a valid object: %s", buffer.buf);
211 static void reset_hard(unsigned const char *sha1, int verbose)
213 int i = 0;
214 const char *args[6];
216 args[i++] = "read-tree";
217 if (verbose)
218 args[i++] = "-v";
219 args[i++] = "--reset";
220 args[i++] = "-u";
221 args[i++] = sha1_to_hex(sha1);
222 args[i] = NULL;
224 if (run_command_v_opt(args, RUN_GIT_CMD))
225 die("read-tree failed");
228 static void restore_state(void)
230 struct strbuf sb;
231 const char *args[] = { "stash", "apply", NULL, NULL };
233 if (is_null_sha1(stash))
234 return;
236 reset_hard(head, 1);
238 strbuf_init(&sb, 0);
239 args[2] = sha1_to_hex(stash);
242 * It is OK to ignore error here, for example when there was
243 * nothing to restore.
245 run_command_v_opt(args, RUN_GIT_CMD);
247 strbuf_release(&sb);
248 refresh_cache(REFRESH_QUIET);
251 /* This is called when no merge was necessary. */
252 static void finish_up_to_date(const char *msg)
254 printf("%s%s\n", squash ? " (nothing to squash)" : "", msg);
255 drop_save();
258 static void squash_message(void)
260 struct rev_info rev;
261 struct commit *commit;
262 struct strbuf out;
263 struct commit_list *j;
264 int fd;
266 printf("Squash commit -- not updating HEAD\n");
267 fd = open(git_path("SQUASH_MSG"), O_WRONLY | O_CREAT, 0666);
268 if (fd < 0)
269 die("Could not write to %s", git_path("SQUASH_MSG"));
271 init_revisions(&rev, NULL);
272 rev.ignore_merges = 1;
273 rev.commit_format = CMIT_FMT_MEDIUM;
275 commit = lookup_commit(head);
276 commit->object.flags |= UNINTERESTING;
277 add_pending_object(&rev, &commit->object, NULL);
279 for (j = remoteheads; j; j = j->next)
280 add_pending_object(&rev, &j->item->object, NULL);
282 setup_revisions(0, NULL, &rev, NULL);
283 if (prepare_revision_walk(&rev))
284 die("revision walk setup failed");
286 strbuf_init(&out, 0);
287 strbuf_addstr(&out, "Squashed commit of the following:\n");
288 while ((commit = get_revision(&rev)) != NULL) {
289 strbuf_addch(&out, '\n');
290 strbuf_addf(&out, "commit %s\n",
291 sha1_to_hex(commit->object.sha1));
292 pretty_print_commit(rev.commit_format, commit, &out, rev.abbrev,
293 NULL, NULL, rev.date_mode, 0);
295 write(fd, out.buf, out.len);
296 close(fd);
297 strbuf_release(&out);
300 static int run_hook(const char *name)
302 struct child_process hook;
303 const char *argv[3], *env[2];
304 char index[PATH_MAX];
306 argv[0] = git_path("hooks/%s", name);
307 if (access(argv[0], X_OK) < 0)
308 return 0;
310 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", get_index_file());
311 env[0] = index;
312 env[1] = NULL;
314 if (squash)
315 argv[1] = "1";
316 else
317 argv[1] = "0";
318 argv[2] = NULL;
320 memset(&hook, 0, sizeof(hook));
321 hook.argv = argv;
322 hook.no_stdin = 1;
323 hook.stdout_to_stderr = 1;
324 hook.env = env;
326 return run_command(&hook);
329 static void finish(const unsigned char *new_head, const char *msg)
331 struct strbuf reflog_message;
333 strbuf_init(&reflog_message, 0);
334 if (!msg)
335 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
336 else {
337 printf("%s\n", msg);
338 strbuf_addf(&reflog_message, "%s: %s",
339 getenv("GIT_REFLOG_ACTION"), msg);
341 if (squash) {
342 squash_message();
343 } else {
344 if (!merge_msg.len)
345 printf("No merge message -- not updating HEAD\n");
346 else {
347 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
348 update_ref(reflog_message.buf, "HEAD",
349 new_head, head, 0,
350 DIE_ON_ERR);
352 * We ignore errors in 'gc --auto', since the
353 * user should see them.
355 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
358 if (new_head && show_diffstat) {
359 struct diff_options opts;
360 diff_setup(&opts);
361 opts.output_format |=
362 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
363 opts.detect_rename = DIFF_DETECT_RENAME;
364 if (diff_use_color_default > 0)
365 DIFF_OPT_SET(&opts, COLOR_DIFF);
366 if (diff_setup_done(&opts) < 0)
367 die("diff_setup_done failed");
368 diff_tree_sha1(head, new_head, "", &opts);
369 diffcore_std(&opts);
370 diff_flush(&opts);
373 /* Run a post-merge hook */
374 run_hook("post-merge");
376 strbuf_release(&reflog_message);
379 /* Get the name for the merge commit's message. */
380 static void merge_name(const char *remote, struct strbuf *msg)
382 struct object *remote_head;
383 unsigned char branch_head[20], buf_sha[20];
384 struct strbuf buf;
385 const char *ptr;
386 int len, early;
388 memset(branch_head, 0, sizeof(branch_head));
389 remote_head = peel_to_type(remote, 0, NULL, OBJ_COMMIT);
390 if (!remote_head)
391 die("'%s' does not point to a commit", remote);
393 strbuf_init(&buf, 0);
394 strbuf_addstr(&buf, "refs/heads/");
395 strbuf_addstr(&buf, remote);
396 resolve_ref(buf.buf, branch_head, 0, 0);
398 if (!hashcmp(remote_head->sha1, branch_head)) {
399 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
400 sha1_to_hex(branch_head), remote);
401 return;
404 /* See if remote matches <name>^^^.. or <name>~<number> */
405 for (len = 0, ptr = remote + strlen(remote);
406 remote < ptr && ptr[-1] == '^';
407 ptr--)
408 len++;
409 if (len)
410 early = 1;
411 else {
412 early = 0;
413 ptr = strrchr(remote, '~');
414 if (ptr) {
415 int seen_nonzero = 0;
417 len++; /* count ~ */
418 while (*++ptr && isdigit(*ptr)) {
419 seen_nonzero |= (*ptr != '0');
420 len++;
422 if (*ptr)
423 len = 0; /* not ...~<number> */
424 else if (seen_nonzero)
425 early = 1;
426 else if (len == 1)
427 early = 1; /* "name~" is "name~1"! */
430 if (len) {
431 struct strbuf truname = STRBUF_INIT;
432 strbuf_addstr(&truname, "refs/heads/");
433 strbuf_addstr(&truname, remote);
434 strbuf_setlen(&truname, truname.len - len);
435 if (resolve_ref(truname.buf, buf_sha, 0, 0)) {
436 strbuf_addf(msg,
437 "%s\t\tbranch '%s'%s of .\n",
438 sha1_to_hex(remote_head->sha1),
439 truname.buf + 11,
440 (early ? " (early part)" : ""));
441 return;
445 if (!strcmp(remote, "FETCH_HEAD") &&
446 !access(git_path("FETCH_HEAD"), R_OK)) {
447 FILE *fp;
448 struct strbuf line;
449 char *ptr;
451 strbuf_init(&line, 0);
452 fp = fopen(git_path("FETCH_HEAD"), "r");
453 if (!fp)
454 die("could not open %s for reading: %s",
455 git_path("FETCH_HEAD"), strerror(errno));
456 strbuf_getline(&line, fp, '\n');
457 fclose(fp);
458 ptr = strstr(line.buf, "\tnot-for-merge\t");
459 if (ptr)
460 strbuf_remove(&line, ptr-line.buf+1, 13);
461 strbuf_addbuf(msg, &line);
462 strbuf_release(&line);
463 return;
465 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
466 sha1_to_hex(remote_head->sha1), remote);
469 static int git_merge_config(const char *k, const char *v, void *cb)
471 if (branch && !prefixcmp(k, "branch.") &&
472 !prefixcmp(k + 7, branch) &&
473 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
474 const char **argv;
475 int argc;
476 char *buf;
478 buf = xstrdup(v);
479 argc = split_cmdline(buf, &argv);
480 if (argc < 0)
481 die("Bad branch.%s.mergeoptions string", branch);
482 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
483 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
484 argc++;
485 parse_options(argc, argv, builtin_merge_options,
486 builtin_merge_usage, 0);
487 free(buf);
490 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
491 show_diffstat = git_config_bool(k, v);
492 else if (!strcmp(k, "pull.twohead"))
493 return git_config_string(&pull_twohead, k, v);
494 else if (!strcmp(k, "pull.octopus"))
495 return git_config_string(&pull_octopus, k, v);
496 else if (!strcmp(k, "merge.log") || !strcmp(k, "merge.summary"))
497 option_log = git_config_bool(k, v);
498 return git_diff_ui_config(k, v, cb);
501 static int read_tree_trivial(unsigned char *common, unsigned char *head,
502 unsigned char *one)
504 int i, nr_trees = 0;
505 struct tree *trees[MAX_UNPACK_TREES];
506 struct tree_desc t[MAX_UNPACK_TREES];
507 struct unpack_trees_options opts;
509 memset(&opts, 0, sizeof(opts));
510 opts.head_idx = 2;
511 opts.src_index = &the_index;
512 opts.dst_index = &the_index;
513 opts.update = 1;
514 opts.verbose_update = 1;
515 opts.trivial_merges_only = 1;
516 opts.merge = 1;
517 trees[nr_trees] = parse_tree_indirect(common);
518 if (!trees[nr_trees++])
519 return -1;
520 trees[nr_trees] = parse_tree_indirect(head);
521 if (!trees[nr_trees++])
522 return -1;
523 trees[nr_trees] = parse_tree_indirect(one);
524 if (!trees[nr_trees++])
525 return -1;
526 opts.fn = threeway_merge;
527 cache_tree_free(&active_cache_tree);
528 for (i = 0; i < nr_trees; i++) {
529 parse_tree(trees[i]);
530 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
532 if (unpack_trees(nr_trees, t, &opts))
533 return -1;
534 return 0;
537 static void write_tree_trivial(unsigned char *sha1)
539 if (write_cache_as_tree(sha1, 0, NULL))
540 die("git write-tree failed to write a tree");
543 static int try_merge_strategy(const char *strategy, struct commit_list *common,
544 const char *head_arg)
546 const char **args;
547 int i = 0, ret;
548 struct commit_list *j;
549 struct strbuf buf;
551 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
552 int clean;
553 struct commit *result;
554 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
555 int index_fd;
556 struct commit_list *reversed = NULL;
557 struct merge_options o;
559 if (remoteheads->next) {
560 error("Not handling anything other than two heads merge.");
561 return 2;
564 init_merge_options(&o);
565 if (!strcmp(strategy, "subtree"))
566 o.subtree_merge = 1;
568 o.branch1 = head_arg;
569 o.branch2 = remoteheads->item->util;
571 for (j = common; j; j = j->next)
572 commit_list_insert(j->item, &reversed);
574 index_fd = hold_locked_index(lock, 1);
575 clean = merge_recursive(&o, lookup_commit(head),
576 remoteheads->item, reversed, &result);
577 if (active_cache_changed &&
578 (write_cache(index_fd, active_cache, active_nr) ||
579 commit_locked_index(lock)))
580 die ("unable to write %s", get_index_file());
581 rollback_lock_file(lock);
582 return clean ? 0 : 1;
583 } else {
584 args = xmalloc((4 + commit_list_count(common) +
585 commit_list_count(remoteheads)) * sizeof(char *));
586 strbuf_init(&buf, 0);
587 strbuf_addf(&buf, "merge-%s", strategy);
588 args[i++] = buf.buf;
589 for (j = common; j; j = j->next)
590 args[i++] = xstrdup(sha1_to_hex(j->item->object.sha1));
591 args[i++] = "--";
592 args[i++] = head_arg;
593 for (j = remoteheads; j; j = j->next)
594 args[i++] = xstrdup(sha1_to_hex(j->item->object.sha1));
595 args[i] = NULL;
596 ret = run_command_v_opt(args, RUN_GIT_CMD);
597 strbuf_release(&buf);
598 i = 1;
599 for (j = common; j; j = j->next)
600 free((void *)args[i++]);
601 i += 2;
602 for (j = remoteheads; j; j = j->next)
603 free((void *)args[i++]);
604 free(args);
605 discard_cache();
606 if (read_cache() < 0)
607 die("failed to read the cache");
608 return -ret;
612 static void count_diff_files(struct diff_queue_struct *q,
613 struct diff_options *opt, void *data)
615 int *count = data;
617 (*count) += q->nr;
620 static int count_unmerged_entries(void)
622 const struct index_state *state = &the_index;
623 int i, ret = 0;
625 for (i = 0; i < state->cache_nr; i++)
626 if (ce_stage(state->cache[i]))
627 ret++;
629 return ret;
632 static int checkout_fast_forward(unsigned char *head, unsigned char *remote)
634 struct tree *trees[MAX_UNPACK_TREES];
635 struct unpack_trees_options opts;
636 struct tree_desc t[MAX_UNPACK_TREES];
637 int i, fd, nr_trees = 0;
638 struct dir_struct dir;
639 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
641 refresh_cache(REFRESH_QUIET);
643 fd = hold_locked_index(lock_file, 1);
645 memset(&trees, 0, sizeof(trees));
646 memset(&opts, 0, sizeof(opts));
647 memset(&t, 0, sizeof(t));
648 memset(&dir, 0, sizeof(dir));
649 dir.show_ignored = 1;
650 dir.exclude_per_dir = ".gitignore";
651 opts.dir = &dir;
653 opts.head_idx = 1;
654 opts.src_index = &the_index;
655 opts.dst_index = &the_index;
656 opts.update = 1;
657 opts.verbose_update = 1;
658 opts.merge = 1;
659 opts.fn = twoway_merge;
661 trees[nr_trees] = parse_tree_indirect(head);
662 if (!trees[nr_trees++])
663 return -1;
664 trees[nr_trees] = parse_tree_indirect(remote);
665 if (!trees[nr_trees++])
666 return -1;
667 for (i = 0; i < nr_trees; i++) {
668 parse_tree(trees[i]);
669 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
671 if (unpack_trees(nr_trees, t, &opts))
672 return -1;
673 if (write_cache(fd, active_cache, active_nr) ||
674 commit_locked_index(lock_file))
675 die("unable to write new index file");
676 return 0;
679 static void split_merge_strategies(const char *string, struct strategy **list,
680 int *nr, int *alloc)
682 char *p, *q, *buf;
684 if (!string)
685 return;
687 buf = xstrdup(string);
688 q = buf;
689 for (;;) {
690 p = strchr(q, ' ');
691 if (!p) {
692 ALLOC_GROW(*list, *nr + 1, *alloc);
693 (*list)[(*nr)++].name = xstrdup(q);
694 free(buf);
695 return;
696 } else {
697 *p = '\0';
698 ALLOC_GROW(*list, *nr + 1, *alloc);
699 (*list)[(*nr)++].name = xstrdup(q);
700 q = ++p;
705 static void add_strategies(const char *string, unsigned attr)
707 struct strategy *list = NULL;
708 int list_alloc = 0, list_nr = 0, i;
710 memset(&list, 0, sizeof(list));
711 split_merge_strategies(string, &list, &list_nr, &list_alloc);
712 if (list) {
713 for (i = 0; i < list_nr; i++)
714 append_strategy(get_strategy(list[i].name));
715 return;
717 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
718 if (all_strategy[i].attr & attr)
719 append_strategy(&all_strategy[i]);
723 static int merge_trivial(void)
725 unsigned char result_tree[20], result_commit[20];
726 struct commit_list *parent = xmalloc(sizeof(struct commit_list *));
728 write_tree_trivial(result_tree);
729 printf("Wonderful.\n");
730 parent->item = lookup_commit(head);
731 parent->next = xmalloc(sizeof(struct commit_list *));
732 parent->next->item = remoteheads->item;
733 parent->next->next = NULL;
734 commit_tree(merge_msg.buf, result_tree, parent, result_commit, NULL);
735 finish(result_commit, "In-index merge");
736 drop_save();
737 return 0;
740 static int finish_automerge(struct commit_list *common,
741 unsigned char *result_tree,
742 const char *wt_strategy)
744 struct commit_list *parents = NULL, *j;
745 struct strbuf buf = STRBUF_INIT;
746 unsigned char result_commit[20];
748 free_commit_list(common);
749 if (allow_fast_forward) {
750 parents = remoteheads;
751 commit_list_insert(lookup_commit(head), &parents);
752 parents = reduce_heads(parents);
753 } else {
754 struct commit_list **pptr = &parents;
756 pptr = &commit_list_insert(lookup_commit(head),
757 pptr)->next;
758 for (j = remoteheads; j; j = j->next)
759 pptr = &commit_list_insert(j->item, pptr)->next;
761 free_commit_list(remoteheads);
762 strbuf_addch(&merge_msg, '\n');
763 commit_tree(merge_msg.buf, result_tree, parents, result_commit, NULL);
764 strbuf_addf(&buf, "Merge made by %s.", wt_strategy);
765 finish(result_commit, buf.buf);
766 strbuf_release(&buf);
767 drop_save();
768 return 0;
771 static int suggest_conflicts(void)
773 FILE *fp;
774 int pos;
776 fp = fopen(git_path("MERGE_MSG"), "a");
777 if (!fp)
778 die("Could open %s for writing", git_path("MERGE_MSG"));
779 fprintf(fp, "\nConflicts:\n");
780 for (pos = 0; pos < active_nr; pos++) {
781 struct cache_entry *ce = active_cache[pos];
783 if (ce_stage(ce)) {
784 fprintf(fp, "\t%s\n", ce->name);
785 while (pos + 1 < active_nr &&
786 !strcmp(ce->name,
787 active_cache[pos + 1]->name))
788 pos++;
791 fclose(fp);
792 rerere();
793 printf("Automatic merge failed; "
794 "fix conflicts and then commit the result.\n");
795 return 1;
798 static struct commit *is_old_style_invocation(int argc, const char **argv)
800 struct commit *second_token = NULL;
801 if (argc > 1) {
802 unsigned char second_sha1[20];
804 if (get_sha1(argv[1], second_sha1))
805 return NULL;
806 second_token = lookup_commit_reference_gently(second_sha1, 0);
807 if (!second_token)
808 die("'%s' is not a commit", argv[1]);
809 if (hashcmp(second_token->object.sha1, head))
810 return NULL;
812 return second_token;
815 static int evaluate_result(void)
817 int cnt = 0;
818 struct rev_info rev;
820 /* Check how many files differ. */
821 init_revisions(&rev, "");
822 setup_revisions(0, NULL, &rev, NULL);
823 rev.diffopt.output_format |=
824 DIFF_FORMAT_CALLBACK;
825 rev.diffopt.format_callback = count_diff_files;
826 rev.diffopt.format_callback_data = &cnt;
827 run_diff_files(&rev, 0);
830 * Check how many unmerged entries are
831 * there.
833 cnt += count_unmerged_entries();
835 return cnt;
838 int cmd_merge(int argc, const char **argv, const char *prefix)
840 unsigned char result_tree[20];
841 struct strbuf buf;
842 const char *head_arg;
843 int flag, head_invalid = 0, i;
844 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
845 struct commit_list *common = NULL;
846 const char *best_strategy = NULL, *wt_strategy = NULL;
847 struct commit_list **remotes = &remoteheads;
849 setup_work_tree();
850 if (read_cache_unmerged())
851 die("You are in the middle of a conflicted merge.");
854 * Check if we are _not_ on a detached HEAD, i.e. if there is a
855 * current branch.
857 branch = resolve_ref("HEAD", head, 0, &flag);
858 if (branch && !prefixcmp(branch, "refs/heads/"))
859 branch += 11;
860 if (is_null_sha1(head))
861 head_invalid = 1;
863 git_config(git_merge_config, NULL);
865 /* for color.ui */
866 if (diff_use_color_default == -1)
867 diff_use_color_default = git_use_color_default;
869 argc = parse_options(argc, argv, builtin_merge_options,
870 builtin_merge_usage, 0);
872 if (squash) {
873 if (!allow_fast_forward)
874 die("You cannot combine --squash with --no-ff.");
875 option_commit = 0;
878 if (!argc)
879 usage_with_options(builtin_merge_usage,
880 builtin_merge_options);
883 * This could be traditional "merge <msg> HEAD <commit>..." and
884 * the way we can tell it is to see if the second token is HEAD,
885 * but some people might have misused the interface and used a
886 * committish that is the same as HEAD there instead.
887 * Traditional format never would have "-m" so it is an
888 * additional safety measure to check for it.
890 strbuf_init(&buf, 0);
892 if (!have_message && is_old_style_invocation(argc, argv)) {
893 strbuf_addstr(&merge_msg, argv[0]);
894 head_arg = argv[1];
895 argv += 2;
896 argc -= 2;
897 } else if (head_invalid) {
898 struct object *remote_head;
900 * If the merged head is a valid one there is no reason
901 * to forbid "git merge" into a branch yet to be born.
902 * We do the same for "git pull".
904 if (argc != 1)
905 die("Can merge only exactly one commit into "
906 "empty head");
907 if (squash)
908 die("Squash commit into empty head not supported yet");
909 if (!allow_fast_forward)
910 die("Non-fast-forward commit does not make sense into "
911 "an empty head");
912 remote_head = peel_to_type(argv[0], 0, NULL, OBJ_COMMIT);
913 if (!remote_head)
914 die("%s - not something we can merge", argv[0]);
915 update_ref("initial pull", "HEAD", remote_head->sha1, NULL, 0,
916 DIE_ON_ERR);
917 reset_hard(remote_head->sha1, 0);
918 return 0;
919 } else {
920 struct strbuf msg;
922 /* We are invoked directly as the first-class UI. */
923 head_arg = "HEAD";
926 * All the rest are the commits being merged;
927 * prepare the standard merge summary message to
928 * be appended to the given message. If remote
929 * is invalid we will die later in the common
930 * codepath so we discard the error in this
931 * loop.
933 strbuf_init(&msg, 0);
934 for (i = 0; i < argc; i++)
935 merge_name(argv[i], &msg);
936 fmt_merge_msg(option_log, &msg, &merge_msg);
937 if (merge_msg.len)
938 strbuf_setlen(&merge_msg, merge_msg.len-1);
941 if (head_invalid || !argc)
942 usage_with_options(builtin_merge_usage,
943 builtin_merge_options);
945 strbuf_addstr(&buf, "merge");
946 for (i = 0; i < argc; i++)
947 strbuf_addf(&buf, " %s", argv[i]);
948 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
949 strbuf_reset(&buf);
951 for (i = 0; i < argc; i++) {
952 struct object *o;
953 struct commit *commit;
955 o = peel_to_type(argv[i], 0, NULL, OBJ_COMMIT);
956 if (!o)
957 die("%s - not something we can merge", argv[i]);
958 commit = lookup_commit(o->sha1);
959 commit->util = (void *)argv[i];
960 remotes = &commit_list_insert(commit, remotes)->next;
962 strbuf_addf(&buf, "GITHEAD_%s", sha1_to_hex(o->sha1));
963 setenv(buf.buf, argv[i], 1);
964 strbuf_reset(&buf);
967 if (!use_strategies) {
968 if (!remoteheads->next)
969 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
970 else
971 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
974 for (i = 0; i < use_strategies_nr; i++) {
975 if (use_strategies[i]->attr & NO_FAST_FORWARD)
976 allow_fast_forward = 0;
977 if (use_strategies[i]->attr & NO_TRIVIAL)
978 allow_trivial = 0;
981 if (!remoteheads->next)
982 common = get_merge_bases(lookup_commit(head),
983 remoteheads->item, 1);
984 else {
985 struct commit_list *list = remoteheads;
986 commit_list_insert(lookup_commit(head), &list);
987 common = get_octopus_merge_bases(list);
988 free(list);
991 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head, NULL, 0,
992 DIE_ON_ERR);
994 if (!common)
995 ; /* No common ancestors found. We need a real merge. */
996 else if (!remoteheads->next && !common->next &&
997 common->item == remoteheads->item) {
999 * If head can reach all the merge then we are up to date.
1000 * but first the most common case of merging one remote.
1002 finish_up_to_date("Already up-to-date.");
1003 return 0;
1004 } else if (allow_fast_forward && !remoteheads->next &&
1005 !common->next &&
1006 !hashcmp(common->item->object.sha1, head)) {
1007 /* Again the most common case of merging one remote. */
1008 struct strbuf msg;
1009 struct object *o;
1010 char hex[41];
1012 strcpy(hex, find_unique_abbrev(head, DEFAULT_ABBREV));
1014 printf("Updating %s..%s\n",
1015 hex,
1016 find_unique_abbrev(remoteheads->item->object.sha1,
1017 DEFAULT_ABBREV));
1018 strbuf_init(&msg, 0);
1019 strbuf_addstr(&msg, "Fast forward");
1020 if (have_message)
1021 strbuf_addstr(&msg,
1022 " (no commit created; -m option ignored)");
1023 o = peel_to_type(sha1_to_hex(remoteheads->item->object.sha1),
1024 0, NULL, OBJ_COMMIT);
1025 if (!o)
1026 return 1;
1028 if (checkout_fast_forward(head, remoteheads->item->object.sha1))
1029 return 1;
1031 finish(o->sha1, msg.buf);
1032 drop_save();
1033 return 0;
1034 } else if (!remoteheads->next && common->next)
1037 * We are not doing octopus and not fast forward. Need
1038 * a real merge.
1040 else if (!remoteheads->next && !common->next && option_commit) {
1042 * We are not doing octopus, not fast forward, and have
1043 * only one common.
1045 refresh_cache(REFRESH_QUIET);
1046 if (allow_trivial) {
1047 /* See if it is really trivial. */
1048 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1049 printf("Trying really trivial in-index merge...\n");
1050 if (!read_tree_trivial(common->item->object.sha1,
1051 head, remoteheads->item->object.sha1))
1052 return merge_trivial();
1053 printf("Nope.\n");
1055 } else {
1057 * An octopus. If we can reach all the remote we are up
1058 * to date.
1060 int up_to_date = 1;
1061 struct commit_list *j;
1063 for (j = remoteheads; j; j = j->next) {
1064 struct commit_list *common_one;
1067 * Here we *have* to calculate the individual
1068 * merge_bases again, otherwise "git merge HEAD^
1069 * HEAD^^" would be missed.
1071 common_one = get_merge_bases(lookup_commit(head),
1072 j->item, 1);
1073 if (hashcmp(common_one->item->object.sha1,
1074 j->item->object.sha1)) {
1075 up_to_date = 0;
1076 break;
1079 if (up_to_date) {
1080 finish_up_to_date("Already up-to-date. Yeeah!");
1081 return 0;
1085 /* We are going to make a new commit. */
1086 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1089 * At this point, we need a real merge. No matter what strategy
1090 * we use, it would operate on the index, possibly affecting the
1091 * working tree, and when resolved cleanly, have the desired
1092 * tree in the index -- this means that the index must be in
1093 * sync with the head commit. The strategies are responsible
1094 * to ensure this.
1096 if (use_strategies_nr != 1) {
1098 * Stash away the local changes so that we can try more
1099 * than one.
1101 save_state();
1102 } else {
1103 memcpy(stash, null_sha1, 20);
1106 for (i = 0; i < use_strategies_nr; i++) {
1107 int ret;
1108 if (i) {
1109 printf("Rewinding the tree to pristine...\n");
1110 restore_state();
1112 if (use_strategies_nr != 1)
1113 printf("Trying merge strategy %s...\n",
1114 use_strategies[i]->name);
1116 * Remember which strategy left the state in the working
1117 * tree.
1119 wt_strategy = use_strategies[i]->name;
1121 ret = try_merge_strategy(use_strategies[i]->name,
1122 common, head_arg);
1123 if (!option_commit && !ret) {
1124 merge_was_ok = 1;
1126 * This is necessary here just to avoid writing
1127 * the tree, but later we will *not* exit with
1128 * status code 1 because merge_was_ok is set.
1130 ret = 1;
1133 if (ret) {
1135 * The backend exits with 1 when conflicts are
1136 * left to be resolved, with 2 when it does not
1137 * handle the given merge at all.
1139 if (ret == 1) {
1140 int cnt = evaluate_result();
1142 if (best_cnt <= 0 || cnt <= best_cnt) {
1143 best_strategy = use_strategies[i]->name;
1144 best_cnt = cnt;
1147 if (merge_was_ok)
1148 break;
1149 else
1150 continue;
1153 /* Automerge succeeded. */
1154 write_tree_trivial(result_tree);
1155 automerge_was_ok = 1;
1156 break;
1160 * If we have a resulting tree, that means the strategy module
1161 * auto resolved the merge cleanly.
1163 if (automerge_was_ok)
1164 return finish_automerge(common, result_tree, wt_strategy);
1167 * Pick the result from the best strategy and have the user fix
1168 * it up.
1170 if (!best_strategy) {
1171 restore_state();
1172 if (use_strategies_nr > 1)
1173 fprintf(stderr,
1174 "No merge strategy handled the merge.\n");
1175 else
1176 fprintf(stderr, "Merge with strategy %s failed.\n",
1177 use_strategies[0]->name);
1178 return 2;
1179 } else if (best_strategy == wt_strategy)
1180 ; /* We already have its result in the working tree. */
1181 else {
1182 printf("Rewinding the tree to pristine...\n");
1183 restore_state();
1184 printf("Using the %s to prepare resolving by hand.\n",
1185 best_strategy);
1186 try_merge_strategy(best_strategy, common, head_arg);
1189 if (squash)
1190 finish(NULL, NULL);
1191 else {
1192 int fd;
1193 struct commit_list *j;
1195 for (j = remoteheads; j; j = j->next)
1196 strbuf_addf(&buf, "%s\n",
1197 sha1_to_hex(j->item->object.sha1));
1198 fd = open(git_path("MERGE_HEAD"), O_WRONLY | O_CREAT, 0666);
1199 if (fd < 0)
1200 die("Could open %s for writing",
1201 git_path("MERGE_HEAD"));
1202 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1203 die("Could not write to %s", git_path("MERGE_HEAD"));
1204 close(fd);
1205 strbuf_addch(&merge_msg, '\n');
1206 fd = open(git_path("MERGE_MSG"), O_WRONLY | O_CREAT, 0666);
1207 if (fd < 0)
1208 die("Could open %s for writing", git_path("MERGE_MSG"));
1209 if (write_in_full(fd, merge_msg.buf, merge_msg.len) !=
1210 merge_msg.len)
1211 die("Could not write to %s", git_path("MERGE_MSG"));
1212 close(fd);
1215 if (merge_was_ok) {
1216 fprintf(stderr, "Automatic merge went well; "
1217 "stopped before committing as requested\n");
1218 return 0;
1219 } else
1220 return suggest_conflicts();