Makefile: feed all header files to xgettext
[git/jrn.git] / builtin / merge.c
blob08e01e8a60d7d7f9c60e9e7a3a2f8b4d66c12ce3
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"
27 #include "resolve-undo.h"
28 #include "remote.h"
29 #include "fmt-merge-msg.h"
30 #include "gpg-interface.h"
32 #define DEFAULT_TWOHEAD (1<<0)
33 #define DEFAULT_OCTOPUS (1<<1)
34 #define NO_FAST_FORWARD (1<<2)
35 #define NO_TRIVIAL (1<<3)
37 struct strategy {
38 const char *name;
39 unsigned attr;
42 static const char * const builtin_merge_usage[] = {
43 "git merge [options] [<commit>...]",
44 "git merge [options] <msg> HEAD <commit>",
45 "git merge --abort",
46 NULL
49 static int show_diffstat = 1, shortlog_len = -1, squash;
50 static int option_commit = 1, allow_fast_forward = 1;
51 static int fast_forward_only, option_edit = -1;
52 static int allow_trivial = 1, have_message;
53 static int overwrite_ignore = 1;
54 static struct strbuf merge_msg = STRBUF_INIT;
55 static struct commit_list *remoteheads;
56 static struct strategy **use_strategies;
57 static size_t use_strategies_nr, use_strategies_alloc;
58 static const char **xopts;
59 static size_t xopts_nr, xopts_alloc;
60 static const char *branch;
61 static char *branch_mergeoptions;
62 static int option_renormalize;
63 static int verbosity;
64 static int allow_rerere_auto;
65 static int abort_current_merge;
66 static int show_progress = -1;
67 static int default_to_upstream;
68 static const char *sign_commit;
70 static struct strategy all_strategy[] = {
71 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
72 { "octopus", DEFAULT_OCTOPUS },
73 { "resolve", 0 },
74 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
75 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
78 static const char *pull_twohead, *pull_octopus;
80 static int option_parse_message(const struct option *opt,
81 const char *arg, int unset)
83 struct strbuf *buf = opt->value;
85 if (unset)
86 strbuf_setlen(buf, 0);
87 else if (arg) {
88 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
89 have_message = 1;
90 } else
91 return error(_("switch `m' requires a value"));
92 return 0;
95 static struct strategy *get_strategy(const char *name)
97 int i;
98 struct strategy *ret;
99 static struct cmdnames main_cmds, other_cmds;
100 static int loaded;
102 if (!name)
103 return NULL;
105 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
106 if (!strcmp(name, all_strategy[i].name))
107 return &all_strategy[i];
109 if (!loaded) {
110 struct cmdnames not_strategies;
111 loaded = 1;
113 memset(&not_strategies, 0, sizeof(struct cmdnames));
114 load_command_list("git-merge-", &main_cmds, &other_cmds);
115 for (i = 0; i < main_cmds.cnt; i++) {
116 int j, found = 0;
117 struct cmdname *ent = main_cmds.names[i];
118 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
119 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
120 && !all_strategy[j].name[ent->len])
121 found = 1;
122 if (!found)
123 add_cmdname(&not_strategies, ent->name, ent->len);
125 exclude_cmds(&main_cmds, &not_strategies);
127 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
128 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
129 fprintf(stderr, _("Available strategies are:"));
130 for (i = 0; i < main_cmds.cnt; i++)
131 fprintf(stderr, " %s", main_cmds.names[i]->name);
132 fprintf(stderr, ".\n");
133 if (other_cmds.cnt) {
134 fprintf(stderr, _("Available custom strategies are:"));
135 for (i = 0; i < other_cmds.cnt; i++)
136 fprintf(stderr, " %s", other_cmds.names[i]->name);
137 fprintf(stderr, ".\n");
139 exit(1);
142 ret = xcalloc(1, sizeof(struct strategy));
143 ret->name = xstrdup(name);
144 ret->attr = NO_TRIVIAL;
145 return ret;
148 static void append_strategy(struct strategy *s)
150 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
151 use_strategies[use_strategies_nr++] = s;
154 static int option_parse_strategy(const struct option *opt,
155 const char *name, int unset)
157 if (unset)
158 return 0;
160 append_strategy(get_strategy(name));
161 return 0;
164 static int option_parse_x(const struct option *opt,
165 const char *arg, int unset)
167 if (unset)
168 return 0;
170 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
171 xopts[xopts_nr++] = xstrdup(arg);
172 return 0;
175 static int option_parse_n(const struct option *opt,
176 const char *arg, int unset)
178 show_diffstat = unset;
179 return 0;
182 static struct option builtin_merge_options[] = {
183 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
184 "do not show a diffstat at the end of the merge",
185 PARSE_OPT_NOARG, option_parse_n },
186 OPT_BOOLEAN(0, "stat", &show_diffstat,
187 "show a diffstat at the end of the merge"),
188 OPT_BOOLEAN(0, "summary", &show_diffstat, "(synonym to --stat)"),
189 { OPTION_INTEGER, 0, "log", &shortlog_len, "n",
190 "add (at most <n>) entries from shortlog to merge commit message",
191 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
192 OPT_BOOLEAN(0, "squash", &squash,
193 "create a single commit instead of doing a merge"),
194 OPT_BOOLEAN(0, "commit", &option_commit,
195 "perform a commit if the merge succeeds (default)"),
196 OPT_BOOL('e', "edit", &option_edit,
197 "edit message before committing"),
198 OPT_BOOLEAN(0, "ff", &allow_fast_forward,
199 "allow fast-forward (default)"),
200 OPT_BOOLEAN(0, "ff-only", &fast_forward_only,
201 "abort if fast-forward is not possible"),
202 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
203 OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
204 "merge strategy to use", option_parse_strategy),
205 OPT_CALLBACK('X', "strategy-option", &xopts, "option=value",
206 "option for selected merge strategy", option_parse_x),
207 OPT_CALLBACK('m', "message", &merge_msg, "message",
208 "merge commit message (for a non-fast-forward merge)",
209 option_parse_message),
210 OPT__VERBOSITY(&verbosity),
211 OPT_BOOLEAN(0, "abort", &abort_current_merge,
212 "abort the current in-progress merge"),
213 OPT_SET_INT(0, "progress", &show_progress, "force progress reporting", 1),
214 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, "key id",
215 "GPG sign commit", PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
216 OPT_BOOLEAN(0, "overwrite-ignore", &overwrite_ignore, "update ignored files (default)"),
217 OPT_END()
220 /* Cleans up metadata that is uninteresting after a succeeded merge. */
221 static void drop_save(void)
223 unlink(git_path("MERGE_HEAD"));
224 unlink(git_path("MERGE_MSG"));
225 unlink(git_path("MERGE_MODE"));
228 static int save_state(unsigned char *stash)
230 int len;
231 struct child_process cp;
232 struct strbuf buffer = STRBUF_INIT;
233 const char *argv[] = {"stash", "create", NULL};
235 memset(&cp, 0, sizeof(cp));
236 cp.argv = argv;
237 cp.out = -1;
238 cp.git_cmd = 1;
240 if (start_command(&cp))
241 die(_("could not run stash."));
242 len = strbuf_read(&buffer, cp.out, 1024);
243 close(cp.out);
245 if (finish_command(&cp) || len < 0)
246 die(_("stash failed"));
247 else if (!len) /* no changes */
248 return -1;
249 strbuf_setlen(&buffer, buffer.len-1);
250 if (get_sha1(buffer.buf, stash))
251 die(_("not a valid object: %s"), buffer.buf);
252 return 0;
255 static void read_empty(unsigned const char *sha1, int verbose)
257 int i = 0;
258 const char *args[7];
260 args[i++] = "read-tree";
261 if (verbose)
262 args[i++] = "-v";
263 args[i++] = "-m";
264 args[i++] = "-u";
265 args[i++] = EMPTY_TREE_SHA1_HEX;
266 args[i++] = sha1_to_hex(sha1);
267 args[i] = NULL;
269 if (run_command_v_opt(args, RUN_GIT_CMD))
270 die(_("read-tree failed"));
273 static void reset_hard(unsigned const char *sha1, int verbose)
275 int i = 0;
276 const char *args[6];
278 args[i++] = "read-tree";
279 if (verbose)
280 args[i++] = "-v";
281 args[i++] = "--reset";
282 args[i++] = "-u";
283 args[i++] = sha1_to_hex(sha1);
284 args[i] = NULL;
286 if (run_command_v_opt(args, RUN_GIT_CMD))
287 die(_("read-tree failed"));
290 static void restore_state(const unsigned char *head,
291 const unsigned char *stash)
293 struct strbuf sb = STRBUF_INIT;
294 const char *args[] = { "stash", "apply", NULL, NULL };
296 if (is_null_sha1(stash))
297 return;
299 reset_hard(head, 1);
301 args[2] = sha1_to_hex(stash);
304 * It is OK to ignore error here, for example when there was
305 * nothing to restore.
307 run_command_v_opt(args, RUN_GIT_CMD);
309 strbuf_release(&sb);
310 refresh_cache(REFRESH_QUIET);
313 /* This is called when no merge was necessary. */
314 static void finish_up_to_date(const char *msg)
316 if (verbosity >= 0)
317 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
318 drop_save();
321 static void squash_message(struct commit *commit)
323 struct rev_info rev;
324 struct strbuf out = STRBUF_INIT;
325 struct commit_list *j;
326 const char *filename;
327 int fd;
328 struct pretty_print_context ctx = {0};
330 printf(_("Squash commit -- not updating HEAD\n"));
331 filename = git_path("SQUASH_MSG");
332 fd = open(filename, O_WRONLY | O_CREAT, 0666);
333 if (fd < 0)
334 die_errno(_("Could not write to '%s'"), filename);
336 init_revisions(&rev, NULL);
337 rev.ignore_merges = 1;
338 rev.commit_format = CMIT_FMT_MEDIUM;
340 commit->object.flags |= UNINTERESTING;
341 add_pending_object(&rev, &commit->object, NULL);
343 for (j = remoteheads; j; j = j->next)
344 add_pending_object(&rev, &j->item->object, NULL);
346 setup_revisions(0, NULL, &rev, NULL);
347 if (prepare_revision_walk(&rev))
348 die(_("revision walk setup failed"));
350 ctx.abbrev = rev.abbrev;
351 ctx.date_mode = rev.date_mode;
352 ctx.fmt = rev.commit_format;
354 strbuf_addstr(&out, "Squashed commit of the following:\n");
355 while ((commit = get_revision(&rev)) != NULL) {
356 strbuf_addch(&out, '\n');
357 strbuf_addf(&out, "commit %s\n",
358 sha1_to_hex(commit->object.sha1));
359 pretty_print_commit(&ctx, commit, &out);
361 if (write(fd, out.buf, out.len) < 0)
362 die_errno(_("Writing SQUASH_MSG"));
363 if (close(fd))
364 die_errno(_("Finishing SQUASH_MSG"));
365 strbuf_release(&out);
368 static void finish(struct commit *head_commit,
369 const unsigned char *new_head, const char *msg)
371 struct strbuf reflog_message = STRBUF_INIT;
372 const unsigned char *head = head_commit->object.sha1;
374 if (!msg)
375 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
376 else {
377 if (verbosity >= 0)
378 printf("%s\n", msg);
379 strbuf_addf(&reflog_message, "%s: %s",
380 getenv("GIT_REFLOG_ACTION"), msg);
382 if (squash) {
383 squash_message(head_commit);
384 } else {
385 if (verbosity >= 0 && !merge_msg.len)
386 printf(_("No merge message -- not updating HEAD\n"));
387 else {
388 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
389 update_ref(reflog_message.buf, "HEAD",
390 new_head, head, 0,
391 DIE_ON_ERR);
393 * We ignore errors in 'gc --auto', since the
394 * user should see them.
396 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
399 if (new_head && show_diffstat) {
400 struct diff_options opts;
401 diff_setup(&opts);
402 opts.stat_width = -1; /* use full terminal width */
403 opts.stat_graph_width = -1; /* respect statGraphWidth config */
404 opts.output_format |=
405 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
406 opts.detect_rename = DIFF_DETECT_RENAME;
407 if (diff_setup_done(&opts) < 0)
408 die(_("diff_setup_done failed"));
409 diff_tree_sha1(head, new_head, "", &opts);
410 diffcore_std(&opts);
411 diff_flush(&opts);
414 /* Run a post-merge hook */
415 run_hook(NULL, "post-merge", squash ? "1" : "0", NULL);
417 strbuf_release(&reflog_message);
420 /* Get the name for the merge commit's message. */
421 static void merge_name(const char *remote, struct strbuf *msg)
423 struct commit *remote_head;
424 unsigned char branch_head[20];
425 struct strbuf buf = STRBUF_INIT;
426 struct strbuf bname = STRBUF_INIT;
427 const char *ptr;
428 char *found_ref;
429 int len, early;
431 strbuf_branchname(&bname, remote);
432 remote = bname.buf;
434 memset(branch_head, 0, sizeof(branch_head));
435 remote_head = get_merge_parent(remote);
436 if (!remote_head)
437 die(_("'%s' does not point to a commit"), remote);
439 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
440 if (!prefixcmp(found_ref, "refs/heads/")) {
441 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
442 sha1_to_hex(branch_head), remote);
443 goto cleanup;
445 if (!prefixcmp(found_ref, "refs/tags/")) {
446 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
447 sha1_to_hex(branch_head), remote);
448 goto cleanup;
450 if (!prefixcmp(found_ref, "refs/remotes/")) {
451 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
452 sha1_to_hex(branch_head), remote);
453 goto cleanup;
457 /* See if remote matches <name>^^^.. or <name>~<number> */
458 for (len = 0, ptr = remote + strlen(remote);
459 remote < ptr && ptr[-1] == '^';
460 ptr--)
461 len++;
462 if (len)
463 early = 1;
464 else {
465 early = 0;
466 ptr = strrchr(remote, '~');
467 if (ptr) {
468 int seen_nonzero = 0;
470 len++; /* count ~ */
471 while (*++ptr && isdigit(*ptr)) {
472 seen_nonzero |= (*ptr != '0');
473 len++;
475 if (*ptr)
476 len = 0; /* not ...~<number> */
477 else if (seen_nonzero)
478 early = 1;
479 else if (len == 1)
480 early = 1; /* "name~" is "name~1"! */
483 if (len) {
484 struct strbuf truname = STRBUF_INIT;
485 strbuf_addstr(&truname, "refs/heads/");
486 strbuf_addstr(&truname, remote);
487 strbuf_setlen(&truname, truname.len - len);
488 if (ref_exists(truname.buf)) {
489 strbuf_addf(msg,
490 "%s\t\tbranch '%s'%s of .\n",
491 sha1_to_hex(remote_head->object.sha1),
492 truname.buf + 11,
493 (early ? " (early part)" : ""));
494 strbuf_release(&truname);
495 goto cleanup;
499 if (!strcmp(remote, "FETCH_HEAD") &&
500 !access(git_path("FETCH_HEAD"), R_OK)) {
501 const char *filename;
502 FILE *fp;
503 struct strbuf line = STRBUF_INIT;
504 char *ptr;
506 filename = git_path("FETCH_HEAD");
507 fp = fopen(filename, "r");
508 if (!fp)
509 die_errno(_("could not open '%s' for reading"),
510 filename);
511 strbuf_getline(&line, fp, '\n');
512 fclose(fp);
513 ptr = strstr(line.buf, "\tnot-for-merge\t");
514 if (ptr)
515 strbuf_remove(&line, ptr-line.buf+1, 13);
516 strbuf_addbuf(msg, &line);
517 strbuf_release(&line);
518 goto cleanup;
520 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
521 sha1_to_hex(remote_head->object.sha1), remote);
522 cleanup:
523 strbuf_release(&buf);
524 strbuf_release(&bname);
527 static void parse_branch_merge_options(char *bmo)
529 const char **argv;
530 int argc;
532 if (!bmo)
533 return;
534 argc = split_cmdline(bmo, &argv);
535 if (argc < 0)
536 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
537 split_cmdline_strerror(argc));
538 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
539 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
540 argc++;
541 argv[0] = "branch.*.mergeoptions";
542 parse_options(argc, argv, NULL, builtin_merge_options,
543 builtin_merge_usage, 0);
544 free(argv);
547 static int git_merge_config(const char *k, const char *v, void *cb)
549 int status;
551 if (branch && !prefixcmp(k, "branch.") &&
552 !prefixcmp(k + 7, branch) &&
553 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
554 free(branch_mergeoptions);
555 branch_mergeoptions = xstrdup(v);
556 return 0;
559 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
560 show_diffstat = git_config_bool(k, v);
561 else if (!strcmp(k, "pull.twohead"))
562 return git_config_string(&pull_twohead, k, v);
563 else if (!strcmp(k, "pull.octopus"))
564 return git_config_string(&pull_octopus, k, v);
565 else if (!strcmp(k, "merge.renormalize"))
566 option_renormalize = git_config_bool(k, v);
567 else if (!strcmp(k, "merge.ff")) {
568 int boolval = git_config_maybe_bool(k, v);
569 if (0 <= boolval) {
570 allow_fast_forward = boolval;
571 } else if (v && !strcmp(v, "only")) {
572 allow_fast_forward = 1;
573 fast_forward_only = 1;
574 } /* do not barf on values from future versions of git */
575 return 0;
576 } else if (!strcmp(k, "merge.defaulttoupstream")) {
577 default_to_upstream = git_config_bool(k, v);
578 return 0;
581 status = fmt_merge_msg_config(k, v, cb);
582 if (status)
583 return status;
584 status = git_gpg_config(k, v, NULL);
585 if (status)
586 return status;
587 return git_diff_ui_config(k, v, cb);
590 static int read_tree_trivial(unsigned char *common, unsigned char *head,
591 unsigned char *one)
593 int i, nr_trees = 0;
594 struct tree *trees[MAX_UNPACK_TREES];
595 struct tree_desc t[MAX_UNPACK_TREES];
596 struct unpack_trees_options opts;
598 memset(&opts, 0, sizeof(opts));
599 opts.head_idx = 2;
600 opts.src_index = &the_index;
601 opts.dst_index = &the_index;
602 opts.update = 1;
603 opts.verbose_update = 1;
604 opts.trivial_merges_only = 1;
605 opts.merge = 1;
606 trees[nr_trees] = parse_tree_indirect(common);
607 if (!trees[nr_trees++])
608 return -1;
609 trees[nr_trees] = parse_tree_indirect(head);
610 if (!trees[nr_trees++])
611 return -1;
612 trees[nr_trees] = parse_tree_indirect(one);
613 if (!trees[nr_trees++])
614 return -1;
615 opts.fn = threeway_merge;
616 cache_tree_free(&active_cache_tree);
617 for (i = 0; i < nr_trees; i++) {
618 parse_tree(trees[i]);
619 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
621 if (unpack_trees(nr_trees, t, &opts))
622 return -1;
623 return 0;
626 static void write_tree_trivial(unsigned char *sha1)
628 if (write_cache_as_tree(sha1, 0, NULL))
629 die(_("git write-tree failed to write a tree"));
632 static const char *merge_argument(struct commit *commit)
634 if (commit)
635 return sha1_to_hex(commit->object.sha1);
636 else
637 return EMPTY_TREE_SHA1_HEX;
640 int try_merge_command(const char *strategy, size_t xopts_nr,
641 const char **xopts, struct commit_list *common,
642 const char *head_arg, struct commit_list *remotes)
644 const char **args;
645 int i = 0, x = 0, ret;
646 struct commit_list *j;
647 struct strbuf buf = STRBUF_INIT;
649 args = xmalloc((4 + xopts_nr + commit_list_count(common) +
650 commit_list_count(remotes)) * sizeof(char *));
651 strbuf_addf(&buf, "merge-%s", strategy);
652 args[i++] = buf.buf;
653 for (x = 0; x < xopts_nr; x++) {
654 char *s = xmalloc(strlen(xopts[x])+2+1);
655 strcpy(s, "--");
656 strcpy(s+2, xopts[x]);
657 args[i++] = s;
659 for (j = common; j; j = j->next)
660 args[i++] = xstrdup(merge_argument(j->item));
661 args[i++] = "--";
662 args[i++] = head_arg;
663 for (j = remotes; j; j = j->next)
664 args[i++] = xstrdup(merge_argument(j->item));
665 args[i] = NULL;
666 ret = run_command_v_opt(args, RUN_GIT_CMD);
667 strbuf_release(&buf);
668 i = 1;
669 for (x = 0; x < xopts_nr; x++)
670 free((void *)args[i++]);
671 for (j = common; j; j = j->next)
672 free((void *)args[i++]);
673 i += 2;
674 for (j = remotes; j; j = j->next)
675 free((void *)args[i++]);
676 free(args);
677 discard_cache();
678 if (read_cache() < 0)
679 die(_("failed to read the cache"));
680 resolve_undo_clear();
682 return ret;
685 static int try_merge_strategy(const char *strategy, struct commit_list *common,
686 struct commit *head, const char *head_arg)
688 int index_fd;
689 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
691 index_fd = hold_locked_index(lock, 1);
692 refresh_cache(REFRESH_QUIET);
693 if (active_cache_changed &&
694 (write_cache(index_fd, active_cache, active_nr) ||
695 commit_locked_index(lock)))
696 return error(_("Unable to write index."));
697 rollback_lock_file(lock);
699 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
700 int clean, x;
701 struct commit *result;
702 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
703 int index_fd;
704 struct commit_list *reversed = NULL;
705 struct merge_options o;
706 struct commit_list *j;
708 if (remoteheads->next) {
709 error(_("Not handling anything other than two heads merge."));
710 return 2;
713 init_merge_options(&o);
714 if (!strcmp(strategy, "subtree"))
715 o.subtree_shift = "";
717 o.renormalize = option_renormalize;
718 o.show_rename_progress =
719 show_progress == -1 ? isatty(2) : show_progress;
721 for (x = 0; x < xopts_nr; x++)
722 if (parse_merge_opt(&o, xopts[x]))
723 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
725 o.branch1 = head_arg;
726 o.branch2 = merge_remote_util(remoteheads->item)->name;
728 for (j = common; j; j = j->next)
729 commit_list_insert(j->item, &reversed);
731 index_fd = hold_locked_index(lock, 1);
732 clean = merge_recursive(&o, head,
733 remoteheads->item, reversed, &result);
734 if (active_cache_changed &&
735 (write_cache(index_fd, active_cache, active_nr) ||
736 commit_locked_index(lock)))
737 die (_("unable to write %s"), get_index_file());
738 rollback_lock_file(lock);
739 return clean ? 0 : 1;
740 } else {
741 return try_merge_command(strategy, xopts_nr, xopts,
742 common, head_arg, remoteheads);
746 static void count_diff_files(struct diff_queue_struct *q,
747 struct diff_options *opt, void *data)
749 int *count = data;
751 (*count) += q->nr;
754 static int count_unmerged_entries(void)
756 int i, ret = 0;
758 for (i = 0; i < active_nr; i++)
759 if (ce_stage(active_cache[i]))
760 ret++;
762 return ret;
765 int checkout_fast_forward(const unsigned char *head, const unsigned char *remote)
767 struct tree *trees[MAX_UNPACK_TREES];
768 struct unpack_trees_options opts;
769 struct tree_desc t[MAX_UNPACK_TREES];
770 int i, fd, nr_trees = 0;
771 struct dir_struct dir;
772 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
774 refresh_cache(REFRESH_QUIET);
776 fd = hold_locked_index(lock_file, 1);
778 memset(&trees, 0, sizeof(trees));
779 memset(&opts, 0, sizeof(opts));
780 memset(&t, 0, sizeof(t));
781 if (overwrite_ignore) {
782 memset(&dir, 0, sizeof(dir));
783 dir.flags |= DIR_SHOW_IGNORED;
784 setup_standard_excludes(&dir);
785 opts.dir = &dir;
788 opts.head_idx = 1;
789 opts.src_index = &the_index;
790 opts.dst_index = &the_index;
791 opts.update = 1;
792 opts.verbose_update = 1;
793 opts.merge = 1;
794 opts.fn = twoway_merge;
795 setup_unpack_trees_porcelain(&opts, "merge");
797 trees[nr_trees] = parse_tree_indirect(head);
798 if (!trees[nr_trees++])
799 return -1;
800 trees[nr_trees] = parse_tree_indirect(remote);
801 if (!trees[nr_trees++])
802 return -1;
803 for (i = 0; i < nr_trees; i++) {
804 parse_tree(trees[i]);
805 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
807 if (unpack_trees(nr_trees, t, &opts))
808 return -1;
809 if (write_cache(fd, active_cache, active_nr) ||
810 commit_locked_index(lock_file))
811 die(_("unable to write new index file"));
812 return 0;
815 static void split_merge_strategies(const char *string, struct strategy **list,
816 int *nr, int *alloc)
818 char *p, *q, *buf;
820 if (!string)
821 return;
823 buf = xstrdup(string);
824 q = buf;
825 for (;;) {
826 p = strchr(q, ' ');
827 if (!p) {
828 ALLOC_GROW(*list, *nr + 1, *alloc);
829 (*list)[(*nr)++].name = xstrdup(q);
830 free(buf);
831 return;
832 } else {
833 *p = '\0';
834 ALLOC_GROW(*list, *nr + 1, *alloc);
835 (*list)[(*nr)++].name = xstrdup(q);
836 q = ++p;
841 static void add_strategies(const char *string, unsigned attr)
843 struct strategy *list = NULL;
844 int list_alloc = 0, list_nr = 0, i;
846 memset(&list, 0, sizeof(list));
847 split_merge_strategies(string, &list, &list_nr, &list_alloc);
848 if (list) {
849 for (i = 0; i < list_nr; i++)
850 append_strategy(get_strategy(list[i].name));
851 return;
853 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
854 if (all_strategy[i].attr & attr)
855 append_strategy(&all_strategy[i]);
859 static void write_merge_msg(struct strbuf *msg)
861 const char *filename = git_path("MERGE_MSG");
862 int fd = open(filename, O_WRONLY | O_CREAT, 0666);
863 if (fd < 0)
864 die_errno(_("Could not open '%s' for writing"),
865 filename);
866 if (write_in_full(fd, msg->buf, msg->len) != msg->len)
867 die_errno(_("Could not write to '%s'"), filename);
868 close(fd);
871 static void read_merge_msg(struct strbuf *msg)
873 const char *filename = git_path("MERGE_MSG");
874 strbuf_reset(msg);
875 if (strbuf_read_file(msg, filename, 0) < 0)
876 die_errno(_("Could not read from '%s'"), filename);
879 static void write_merge_state(void);
880 static void abort_commit(const char *err_msg)
882 if (err_msg)
883 error("%s", err_msg);
884 fprintf(stderr,
885 _("Not committing merge; use 'git commit' to complete the merge.\n"));
886 write_merge_state();
887 exit(1);
890 static const char merge_editor_comment[] =
891 N_("Please enter a commit message to explain why this merge is necessary,\n"
892 "especially if it merges an updated upstream into a topic branch.\n"
893 "\n"
894 "Lines starting with '#' will be ignored, and an empty message aborts\n"
895 "the commit.\n");
897 static void prepare_to_commit(void)
899 struct strbuf msg = STRBUF_INIT;
900 const char *comment = _(merge_editor_comment);
901 strbuf_addbuf(&msg, &merge_msg);
902 strbuf_addch(&msg, '\n');
903 if (0 < option_edit)
904 strbuf_add_lines(&msg, "# ", comment, strlen(comment));
905 write_merge_msg(&msg);
906 run_hook(get_index_file(), "prepare-commit-msg",
907 git_path("MERGE_MSG"), "merge", NULL, NULL);
908 if (0 < option_edit) {
909 if (launch_editor(git_path("MERGE_MSG"), NULL, NULL))
910 abort_commit(NULL);
912 read_merge_msg(&msg);
913 stripspace(&msg, 0 < option_edit);
914 if (!msg.len)
915 abort_commit(_("Empty commit message."));
916 strbuf_release(&merge_msg);
917 strbuf_addbuf(&merge_msg, &msg);
918 strbuf_release(&msg);
921 static int merge_trivial(struct commit *head)
923 unsigned char result_tree[20], result_commit[20];
924 struct commit_list *parent = xmalloc(sizeof(*parent));
926 write_tree_trivial(result_tree);
927 printf(_("Wonderful.\n"));
928 parent->item = head;
929 parent->next = xmalloc(sizeof(*parent->next));
930 parent->next->item = remoteheads->item;
931 parent->next->next = NULL;
932 prepare_to_commit();
933 if (commit_tree(&merge_msg, result_tree, parent, result_commit, NULL,
934 sign_commit))
935 die(_("failed to write commit object"));
936 finish(head, result_commit, "In-index merge");
937 drop_save();
938 return 0;
941 static int finish_automerge(struct commit *head,
942 struct commit_list *common,
943 unsigned char *result_tree,
944 const char *wt_strategy)
946 struct commit_list *parents = NULL, *j;
947 struct strbuf buf = STRBUF_INIT;
948 unsigned char result_commit[20];
950 free_commit_list(common);
951 if (allow_fast_forward) {
952 parents = remoteheads;
953 commit_list_insert(head, &parents);
954 parents = reduce_heads(parents);
955 } else {
956 struct commit_list **pptr = &parents;
958 pptr = &commit_list_insert(head,
959 pptr)->next;
960 for (j = remoteheads; j; j = j->next)
961 pptr = &commit_list_insert(j->item, pptr)->next;
963 strbuf_addch(&merge_msg, '\n');
964 prepare_to_commit();
965 free_commit_list(remoteheads);
966 if (commit_tree(&merge_msg, result_tree, parents, result_commit,
967 NULL, sign_commit))
968 die(_("failed to write commit object"));
969 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
970 finish(head, result_commit, buf.buf);
971 strbuf_release(&buf);
972 drop_save();
973 return 0;
976 static int suggest_conflicts(int renormalizing)
978 const char *filename;
979 FILE *fp;
980 int pos;
982 filename = git_path("MERGE_MSG");
983 fp = fopen(filename, "a");
984 if (!fp)
985 die_errno(_("Could not open '%s' for writing"), filename);
986 fprintf(fp, "\nConflicts:\n");
987 for (pos = 0; pos < active_nr; pos++) {
988 struct cache_entry *ce = active_cache[pos];
990 if (ce_stage(ce)) {
991 fprintf(fp, "\t%s\n", ce->name);
992 while (pos + 1 < active_nr &&
993 !strcmp(ce->name,
994 active_cache[pos + 1]->name))
995 pos++;
998 fclose(fp);
999 rerere(allow_rerere_auto);
1000 printf(_("Automatic merge failed; "
1001 "fix conflicts and then commit the result.\n"));
1002 return 1;
1005 static struct commit *is_old_style_invocation(int argc, const char **argv,
1006 const unsigned char *head)
1008 struct commit *second_token = NULL;
1009 if (argc > 2) {
1010 unsigned char second_sha1[20];
1012 if (get_sha1(argv[1], second_sha1))
1013 return NULL;
1014 second_token = lookup_commit_reference_gently(second_sha1, 0);
1015 if (!second_token)
1016 die(_("'%s' is not a commit"), argv[1]);
1017 if (hashcmp(second_token->object.sha1, head))
1018 return NULL;
1020 return second_token;
1023 static int evaluate_result(void)
1025 int cnt = 0;
1026 struct rev_info rev;
1028 /* Check how many files differ. */
1029 init_revisions(&rev, "");
1030 setup_revisions(0, NULL, &rev, NULL);
1031 rev.diffopt.output_format |=
1032 DIFF_FORMAT_CALLBACK;
1033 rev.diffopt.format_callback = count_diff_files;
1034 rev.diffopt.format_callback_data = &cnt;
1035 run_diff_files(&rev, 0);
1038 * Check how many unmerged entries are
1039 * there.
1041 cnt += count_unmerged_entries();
1043 return cnt;
1047 * Pretend as if the user told us to merge with the tracking
1048 * branch we have for the upstream of the current branch
1050 static int setup_with_upstream(const char ***argv)
1052 struct branch *branch = branch_get(NULL);
1053 int i;
1054 const char **args;
1056 if (!branch)
1057 die(_("No current branch."));
1058 if (!branch->remote)
1059 die(_("No remote for the current branch."));
1060 if (!branch->merge_nr)
1061 die(_("No default upstream defined for the current branch."));
1063 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
1064 for (i = 0; i < branch->merge_nr; i++) {
1065 if (!branch->merge[i]->dst)
1066 die(_("No remote tracking branch for %s from %s"),
1067 branch->merge[i]->src, branch->remote_name);
1068 args[i] = branch->merge[i]->dst;
1070 args[i] = NULL;
1071 *argv = args;
1072 return i;
1075 static void write_merge_state(void)
1077 const char *filename;
1078 int fd;
1079 struct commit_list *j;
1080 struct strbuf buf = STRBUF_INIT;
1082 for (j = remoteheads; j; j = j->next) {
1083 unsigned const char *sha1;
1084 struct commit *c = j->item;
1085 if (c->util && merge_remote_util(c)->obj) {
1086 sha1 = merge_remote_util(c)->obj->sha1;
1087 } else {
1088 sha1 = c->object.sha1;
1090 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
1092 filename = git_path("MERGE_HEAD");
1093 fd = open(filename, O_WRONLY | O_CREAT, 0666);
1094 if (fd < 0)
1095 die_errno(_("Could not open '%s' for writing"), filename);
1096 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1097 die_errno(_("Could not write to '%s'"), filename);
1098 close(fd);
1099 strbuf_addch(&merge_msg, '\n');
1100 write_merge_msg(&merge_msg);
1102 filename = git_path("MERGE_MODE");
1103 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
1104 if (fd < 0)
1105 die_errno(_("Could not open '%s' for writing"), filename);
1106 strbuf_reset(&buf);
1107 if (!allow_fast_forward)
1108 strbuf_addf(&buf, "no-ff");
1109 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1110 die_errno(_("Could not write to '%s'"), filename);
1111 close(fd);
1114 static int default_edit_option(void)
1116 static const char name[] = "GIT_MERGE_AUTOEDIT";
1117 const char *e = getenv(name);
1118 struct stat st_stdin, st_stdout;
1120 if (have_message)
1121 /* an explicit -m msg without --[no-]edit */
1122 return 0;
1124 if (e) {
1125 int v = git_config_maybe_bool(name, e);
1126 if (v < 0)
1127 die("Bad value '%s' in environment '%s'", e, name);
1128 return v;
1131 /* Use editor if stdin and stdout are the same and is a tty */
1132 return (!fstat(0, &st_stdin) &&
1133 !fstat(1, &st_stdout) &&
1134 isatty(0) && isatty(1) &&
1135 st_stdin.st_dev == st_stdout.st_dev &&
1136 st_stdin.st_ino == st_stdout.st_ino &&
1137 st_stdin.st_mode == st_stdout.st_mode);
1141 int cmd_merge(int argc, const char **argv, const char *prefix)
1143 unsigned char result_tree[20];
1144 unsigned char stash[20];
1145 unsigned char head_sha1[20];
1146 struct commit *head_commit;
1147 struct strbuf buf = STRBUF_INIT;
1148 const char *head_arg;
1149 int flag, i, ret = 0;
1150 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1151 struct commit_list *common = NULL;
1152 const char *best_strategy = NULL, *wt_strategy = NULL;
1153 struct commit_list **remotes = &remoteheads;
1154 void *branch_to_free;
1156 if (argc == 2 && !strcmp(argv[1], "-h"))
1157 usage_with_options(builtin_merge_usage, builtin_merge_options);
1160 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1161 * current branch.
1163 branch = branch_to_free = resolve_refdup("HEAD", head_sha1, 0, &flag);
1164 if (branch && !prefixcmp(branch, "refs/heads/"))
1165 branch += 11;
1166 if (!branch || is_null_sha1(head_sha1))
1167 head_commit = NULL;
1168 else
1169 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1171 git_config(git_merge_config, NULL);
1173 if (branch_mergeoptions)
1174 parse_branch_merge_options(branch_mergeoptions);
1175 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1176 builtin_merge_usage, 0);
1177 if (shortlog_len < 0)
1178 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1180 if (verbosity < 0 && show_progress == -1)
1181 show_progress = 0;
1183 if (abort_current_merge) {
1184 int nargc = 2;
1185 const char *nargv[] = {"reset", "--merge", NULL};
1187 if (!file_exists(git_path("MERGE_HEAD")))
1188 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1190 /* Invoke 'git reset --merge' */
1191 ret = cmd_reset(nargc, nargv, prefix);
1192 goto done;
1195 if (read_cache_unmerged())
1196 die_resolve_conflict("merge");
1198 if (file_exists(git_path("MERGE_HEAD"))) {
1200 * There is no unmerged entry, don't advise 'git
1201 * add/rm <file>', just 'git commit'.
1203 if (advice_resolve_conflict)
1204 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1205 "Please, commit your changes before you can merge."));
1206 else
1207 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1209 if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
1210 if (advice_resolve_conflict)
1211 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1212 "Please, commit your changes before you can merge."));
1213 else
1214 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1216 resolve_undo_clear();
1218 if (verbosity < 0)
1219 show_diffstat = 0;
1221 if (squash) {
1222 if (!allow_fast_forward)
1223 die(_("You cannot combine --squash with --no-ff."));
1224 option_commit = 0;
1227 if (!allow_fast_forward && fast_forward_only)
1228 die(_("You cannot combine --no-ff with --ff-only."));
1230 if (!abort_current_merge) {
1231 if (!argc) {
1232 if (default_to_upstream)
1233 argc = setup_with_upstream(&argv);
1234 else
1235 die(_("No commit specified and merge.defaultToUpstream not set."));
1236 } else if (argc == 1 && !strcmp(argv[0], "-"))
1237 argv[0] = "@{-1}";
1239 if (!argc)
1240 usage_with_options(builtin_merge_usage,
1241 builtin_merge_options);
1244 * This could be traditional "merge <msg> HEAD <commit>..." and
1245 * the way we can tell it is to see if the second token is HEAD,
1246 * but some people might have misused the interface and used a
1247 * committish that is the same as HEAD there instead.
1248 * Traditional format never would have "-m" so it is an
1249 * additional safety measure to check for it.
1252 if (!have_message && head_commit &&
1253 is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
1254 strbuf_addstr(&merge_msg, argv[0]);
1255 head_arg = argv[1];
1256 argv += 2;
1257 argc -= 2;
1258 } else if (!head_commit) {
1259 struct commit *remote_head;
1261 * If the merged head is a valid one there is no reason
1262 * to forbid "git merge" into a branch yet to be born.
1263 * We do the same for "git pull".
1265 if (argc != 1)
1266 die(_("Can merge only exactly one commit into "
1267 "empty head"));
1268 if (squash)
1269 die(_("Squash commit into empty head not supported yet"));
1270 if (!allow_fast_forward)
1271 die(_("Non-fast-forward commit does not make sense into "
1272 "an empty head"));
1273 remote_head = get_merge_parent(argv[0]);
1274 if (!remote_head)
1275 die(_("%s - not something we can merge"), argv[0]);
1276 read_empty(remote_head->object.sha1, 0);
1277 update_ref("initial pull", "HEAD", remote_head->object.sha1,
1278 NULL, 0, DIE_ON_ERR);
1279 goto done;
1280 } else {
1281 struct strbuf merge_names = STRBUF_INIT;
1283 /* We are invoked directly as the first-class UI. */
1284 head_arg = "HEAD";
1287 * All the rest are the commits being merged; prepare
1288 * the standard merge summary message to be appended
1289 * to the given message.
1291 for (i = 0; i < argc; i++)
1292 merge_name(argv[i], &merge_names);
1294 if (!have_message || shortlog_len) {
1295 struct fmt_merge_msg_opts opts;
1296 memset(&opts, 0, sizeof(opts));
1297 opts.add_title = !have_message;
1298 opts.shortlog_len = shortlog_len;
1300 fmt_merge_msg(&merge_names, &merge_msg, &opts);
1301 if (merge_msg.len)
1302 strbuf_setlen(&merge_msg, merge_msg.len - 1);
1306 if (!head_commit || !argc)
1307 usage_with_options(builtin_merge_usage,
1308 builtin_merge_options);
1310 strbuf_addstr(&buf, "merge");
1311 for (i = 0; i < argc; i++)
1312 strbuf_addf(&buf, " %s", argv[i]);
1313 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1314 strbuf_reset(&buf);
1316 for (i = 0; i < argc; i++) {
1317 struct commit *commit = get_merge_parent(argv[i]);
1318 if (!commit)
1319 die(_("%s - not something we can merge"), argv[i]);
1320 remotes = &commit_list_insert(commit, remotes)->next;
1321 strbuf_addf(&buf, "GITHEAD_%s",
1322 sha1_to_hex(commit->object.sha1));
1323 setenv(buf.buf, argv[i], 1);
1324 strbuf_reset(&buf);
1325 if (!fast_forward_only &&
1326 merge_remote_util(commit) &&
1327 merge_remote_util(commit)->obj &&
1328 merge_remote_util(commit)->obj->type == OBJ_TAG)
1329 allow_fast_forward = 0;
1332 if (option_edit < 0)
1333 option_edit = default_edit_option();
1335 if (!use_strategies) {
1336 if (!remoteheads->next)
1337 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1338 else
1339 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1342 for (i = 0; i < use_strategies_nr; i++) {
1343 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1344 allow_fast_forward = 0;
1345 if (use_strategies[i]->attr & NO_TRIVIAL)
1346 allow_trivial = 0;
1349 if (!remoteheads->next)
1350 common = get_merge_bases(head_commit, remoteheads->item, 1);
1351 else {
1352 struct commit_list *list = remoteheads;
1353 commit_list_insert(head_commit, &list);
1354 common = get_octopus_merge_bases(list);
1355 free(list);
1358 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
1359 NULL, 0, DIE_ON_ERR);
1361 if (!common)
1362 ; /* No common ancestors found. We need a real merge. */
1363 else if (!remoteheads->next && !common->next &&
1364 common->item == remoteheads->item) {
1366 * If head can reach all the merge then we are up to date.
1367 * but first the most common case of merging one remote.
1369 finish_up_to_date("Already up-to-date.");
1370 goto done;
1371 } else if (allow_fast_forward && !remoteheads->next &&
1372 !common->next &&
1373 !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
1374 /* Again the most common case of merging one remote. */
1375 struct strbuf msg = STRBUF_INIT;
1376 struct commit *commit;
1377 char hex[41];
1379 strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
1381 if (verbosity >= 0)
1382 printf(_("Updating %s..%s\n"),
1383 hex,
1384 find_unique_abbrev(remoteheads->item->object.sha1,
1385 DEFAULT_ABBREV));
1386 strbuf_addstr(&msg, "Fast-forward");
1387 if (have_message)
1388 strbuf_addstr(&msg,
1389 " (no commit created; -m option ignored)");
1390 commit = remoteheads->item;
1391 if (!commit) {
1392 ret = 1;
1393 goto done;
1396 if (checkout_fast_forward(head_commit->object.sha1,
1397 commit->object.sha1)) {
1398 ret = 1;
1399 goto done;
1402 finish(head_commit, commit->object.sha1, msg.buf);
1403 drop_save();
1404 goto done;
1405 } else if (!remoteheads->next && common->next)
1408 * We are not doing octopus and not fast-forward. Need
1409 * a real merge.
1411 else if (!remoteheads->next && !common->next && option_commit) {
1413 * We are not doing octopus, not fast-forward, and have
1414 * only one common.
1416 refresh_cache(REFRESH_QUIET);
1417 if (allow_trivial && !fast_forward_only) {
1418 /* See if it is really trivial. */
1419 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1420 printf(_("Trying really trivial in-index merge...\n"));
1421 if (!read_tree_trivial(common->item->object.sha1,
1422 head_commit->object.sha1,
1423 remoteheads->item->object.sha1)) {
1424 ret = merge_trivial(head_commit);
1425 goto done;
1427 printf(_("Nope.\n"));
1429 } else {
1431 * An octopus. If we can reach all the remote we are up
1432 * to date.
1434 int up_to_date = 1;
1435 struct commit_list *j;
1437 for (j = remoteheads; j; j = j->next) {
1438 struct commit_list *common_one;
1441 * Here we *have* to calculate the individual
1442 * merge_bases again, otherwise "git merge HEAD^
1443 * HEAD^^" would be missed.
1445 common_one = get_merge_bases(head_commit, j->item, 1);
1446 if (hashcmp(common_one->item->object.sha1,
1447 j->item->object.sha1)) {
1448 up_to_date = 0;
1449 break;
1452 if (up_to_date) {
1453 finish_up_to_date("Already up-to-date. Yeeah!");
1454 goto done;
1458 if (fast_forward_only)
1459 die(_("Not possible to fast-forward, aborting."));
1461 /* We are going to make a new commit. */
1462 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1465 * At this point, we need a real merge. No matter what strategy
1466 * we use, it would operate on the index, possibly affecting the
1467 * working tree, and when resolved cleanly, have the desired
1468 * tree in the index -- this means that the index must be in
1469 * sync with the head commit. The strategies are responsible
1470 * to ensure this.
1472 if (use_strategies_nr == 1 ||
1474 * Stash away the local changes so that we can try more than one.
1476 save_state(stash))
1477 hashcpy(stash, null_sha1);
1479 for (i = 0; i < use_strategies_nr; i++) {
1480 int ret;
1481 if (i) {
1482 printf(_("Rewinding the tree to pristine...\n"));
1483 restore_state(head_commit->object.sha1, stash);
1485 if (use_strategies_nr != 1)
1486 printf(_("Trying merge strategy %s...\n"),
1487 use_strategies[i]->name);
1489 * Remember which strategy left the state in the working
1490 * tree.
1492 wt_strategy = use_strategies[i]->name;
1494 ret = try_merge_strategy(use_strategies[i]->name,
1495 common, head_commit, head_arg);
1496 if (!option_commit && !ret) {
1497 merge_was_ok = 1;
1499 * This is necessary here just to avoid writing
1500 * the tree, but later we will *not* exit with
1501 * status code 1 because merge_was_ok is set.
1503 ret = 1;
1506 if (ret) {
1508 * The backend exits with 1 when conflicts are
1509 * left to be resolved, with 2 when it does not
1510 * handle the given merge at all.
1512 if (ret == 1) {
1513 int cnt = evaluate_result();
1515 if (best_cnt <= 0 || cnt <= best_cnt) {
1516 best_strategy = use_strategies[i]->name;
1517 best_cnt = cnt;
1520 if (merge_was_ok)
1521 break;
1522 else
1523 continue;
1526 /* Automerge succeeded. */
1527 write_tree_trivial(result_tree);
1528 automerge_was_ok = 1;
1529 break;
1533 * If we have a resulting tree, that means the strategy module
1534 * auto resolved the merge cleanly.
1536 if (automerge_was_ok) {
1537 ret = finish_automerge(head_commit, common, result_tree,
1538 wt_strategy);
1539 goto done;
1543 * Pick the result from the best strategy and have the user fix
1544 * it up.
1546 if (!best_strategy) {
1547 restore_state(head_commit->object.sha1, stash);
1548 if (use_strategies_nr > 1)
1549 fprintf(stderr,
1550 _("No merge strategy handled the merge.\n"));
1551 else
1552 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1553 use_strategies[0]->name);
1554 ret = 2;
1555 goto done;
1556 } else if (best_strategy == wt_strategy)
1557 ; /* We already have its result in the working tree. */
1558 else {
1559 printf(_("Rewinding the tree to pristine...\n"));
1560 restore_state(head_commit->object.sha1, stash);
1561 printf(_("Using the %s to prepare resolving by hand.\n"),
1562 best_strategy);
1563 try_merge_strategy(best_strategy, common, head_commit, head_arg);
1566 if (squash)
1567 finish(head_commit, NULL, NULL);
1568 else
1569 write_merge_state();
1571 if (merge_was_ok)
1572 fprintf(stderr, _("Automatic merge went well; "
1573 "stopped before committing as requested\n"));
1574 else
1575 ret = suggest_conflicts(option_renormalize);
1577 done:
1578 free(branch_to_free);
1579 return ret;