Merge branch 'tr/log-full-diff-keep-true-parents' into maint
[git.git] / builtin / merge.c
blob34a6166b520c8ede9973fbf497b21ac6ecb761ad
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 N_("git merge [options] [<commit>...]"),
44 N_("git merge [options] <msg> HEAD <commit>"),
45 N_("git merge --abort"),
46 NULL
49 static int show_diffstat = 1, shortlog_len = -1, squash;
50 static int option_commit = 1;
51 static int option_edit = -1;
52 static int allow_trivial = 1, have_message, verify_signatures;
53 static int overwrite_ignore = 1;
54 static struct strbuf merge_msg = STRBUF_INIT;
55 static struct strategy **use_strategies;
56 static size_t use_strategies_nr, use_strategies_alloc;
57 static const char **xopts;
58 static size_t xopts_nr, xopts_alloc;
59 static const char *branch;
60 static char *branch_mergeoptions;
61 static int option_renormalize;
62 static int verbosity;
63 static int allow_rerere_auto;
64 static int abort_current_merge;
65 static int show_progress = -1;
66 static int default_to_upstream;
67 static const char *sign_commit;
69 static struct strategy all_strategy[] = {
70 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
71 { "octopus", DEFAULT_OCTOPUS },
72 { "resolve", 0 },
73 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
74 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
77 static const char *pull_twohead, *pull_octopus;
79 enum ff_type {
80 FF_NO,
81 FF_ALLOW,
82 FF_ONLY
85 static enum ff_type fast_forward = FF_ALLOW;
87 static int option_parse_message(const struct option *opt,
88 const char *arg, int unset)
90 struct strbuf *buf = opt->value;
92 if (unset)
93 strbuf_setlen(buf, 0);
94 else if (arg) {
95 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
96 have_message = 1;
97 } else
98 return error(_("switch `m' requires a value"));
99 return 0;
102 static struct strategy *get_strategy(const char *name)
104 int i;
105 struct strategy *ret;
106 static struct cmdnames main_cmds, other_cmds;
107 static int loaded;
109 if (!name)
110 return NULL;
112 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
113 if (!strcmp(name, all_strategy[i].name))
114 return &all_strategy[i];
116 if (!loaded) {
117 struct cmdnames not_strategies;
118 loaded = 1;
120 memset(&not_strategies, 0, sizeof(struct cmdnames));
121 load_command_list("git-merge-", &main_cmds, &other_cmds);
122 for (i = 0; i < main_cmds.cnt; i++) {
123 int j, found = 0;
124 struct cmdname *ent = main_cmds.names[i];
125 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
126 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
127 && !all_strategy[j].name[ent->len])
128 found = 1;
129 if (!found)
130 add_cmdname(&not_strategies, ent->name, ent->len);
132 exclude_cmds(&main_cmds, &not_strategies);
134 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
135 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
136 fprintf(stderr, _("Available strategies are:"));
137 for (i = 0; i < main_cmds.cnt; i++)
138 fprintf(stderr, " %s", main_cmds.names[i]->name);
139 fprintf(stderr, ".\n");
140 if (other_cmds.cnt) {
141 fprintf(stderr, _("Available custom strategies are:"));
142 for (i = 0; i < other_cmds.cnt; i++)
143 fprintf(stderr, " %s", other_cmds.names[i]->name);
144 fprintf(stderr, ".\n");
146 exit(1);
149 ret = xcalloc(1, sizeof(struct strategy));
150 ret->name = xstrdup(name);
151 ret->attr = NO_TRIVIAL;
152 return ret;
155 static void append_strategy(struct strategy *s)
157 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
158 use_strategies[use_strategies_nr++] = s;
161 static int option_parse_strategy(const struct option *opt,
162 const char *name, int unset)
164 if (unset)
165 return 0;
167 append_strategy(get_strategy(name));
168 return 0;
171 static int option_parse_x(const struct option *opt,
172 const char *arg, int unset)
174 if (unset)
175 return 0;
177 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
178 xopts[xopts_nr++] = xstrdup(arg);
179 return 0;
182 static int option_parse_n(const struct option *opt,
183 const char *arg, int unset)
185 show_diffstat = unset;
186 return 0;
189 static int option_parse_ff_only(const struct option *opt,
190 const char *arg, int unset)
192 fast_forward = FF_ONLY;
193 return 0;
196 static struct option builtin_merge_options[] = {
197 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
198 N_("do not show a diffstat at the end of the merge"),
199 PARSE_OPT_NOARG, option_parse_n },
200 OPT_BOOLEAN(0, "stat", &show_diffstat,
201 N_("show a diffstat at the end of the merge")),
202 OPT_BOOLEAN(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
203 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
204 N_("add (at most <n>) entries from shortlog to merge commit message"),
205 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
206 OPT_BOOLEAN(0, "squash", &squash,
207 N_("create a single commit instead of doing a merge")),
208 OPT_BOOLEAN(0, "commit", &option_commit,
209 N_("perform a commit if the merge succeeds (default)")),
210 OPT_BOOL('e', "edit", &option_edit,
211 N_("edit message before committing")),
212 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
213 { OPTION_CALLBACK, 0, "ff-only", NULL, NULL,
214 N_("abort if fast-forward is not possible"),
215 PARSE_OPT_NOARG | PARSE_OPT_NONEG, option_parse_ff_only },
216 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
217 OPT_BOOL(0, "verify-signatures", &verify_signatures,
218 N_("Verify that the named commit has a valid GPG signature")),
219 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
220 N_("merge strategy to use"), option_parse_strategy),
221 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
222 N_("option for selected merge strategy"), option_parse_x),
223 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
224 N_("merge commit message (for a non-fast-forward merge)"),
225 option_parse_message),
226 OPT__VERBOSITY(&verbosity),
227 OPT_BOOLEAN(0, "abort", &abort_current_merge,
228 N_("abort the current in-progress merge")),
229 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
230 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key id"),
231 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
232 OPT_BOOLEAN(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
233 OPT_END()
236 /* Cleans up metadata that is uninteresting after a succeeded merge. */
237 static void drop_save(void)
239 unlink(git_path("MERGE_HEAD"));
240 unlink(git_path("MERGE_MSG"));
241 unlink(git_path("MERGE_MODE"));
244 static int save_state(unsigned char *stash)
246 int len;
247 struct child_process cp;
248 struct strbuf buffer = STRBUF_INIT;
249 const char *argv[] = {"stash", "create", NULL};
251 memset(&cp, 0, sizeof(cp));
252 cp.argv = argv;
253 cp.out = -1;
254 cp.git_cmd = 1;
256 if (start_command(&cp))
257 die(_("could not run stash."));
258 len = strbuf_read(&buffer, cp.out, 1024);
259 close(cp.out);
261 if (finish_command(&cp) || len < 0)
262 die(_("stash failed"));
263 else if (!len) /* no changes */
264 return -1;
265 strbuf_setlen(&buffer, buffer.len-1);
266 if (get_sha1(buffer.buf, stash))
267 die(_("not a valid object: %s"), buffer.buf);
268 return 0;
271 static void read_empty(unsigned const char *sha1, int verbose)
273 int i = 0;
274 const char *args[7];
276 args[i++] = "read-tree";
277 if (verbose)
278 args[i++] = "-v";
279 args[i++] = "-m";
280 args[i++] = "-u";
281 args[i++] = EMPTY_TREE_SHA1_HEX;
282 args[i++] = sha1_to_hex(sha1);
283 args[i] = NULL;
285 if (run_command_v_opt(args, RUN_GIT_CMD))
286 die(_("read-tree failed"));
289 static void reset_hard(unsigned const char *sha1, int verbose)
291 int i = 0;
292 const char *args[6];
294 args[i++] = "read-tree";
295 if (verbose)
296 args[i++] = "-v";
297 args[i++] = "--reset";
298 args[i++] = "-u";
299 args[i++] = sha1_to_hex(sha1);
300 args[i] = NULL;
302 if (run_command_v_opt(args, RUN_GIT_CMD))
303 die(_("read-tree failed"));
306 static void restore_state(const unsigned char *head,
307 const unsigned char *stash)
309 struct strbuf sb = STRBUF_INIT;
310 const char *args[] = { "stash", "apply", NULL, NULL };
312 if (is_null_sha1(stash))
313 return;
315 reset_hard(head, 1);
317 args[2] = sha1_to_hex(stash);
320 * It is OK to ignore error here, for example when there was
321 * nothing to restore.
323 run_command_v_opt(args, RUN_GIT_CMD);
325 strbuf_release(&sb);
326 refresh_cache(REFRESH_QUIET);
329 /* This is called when no merge was necessary. */
330 static void finish_up_to_date(const char *msg)
332 if (verbosity >= 0)
333 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
334 drop_save();
337 static void squash_message(struct commit *commit, struct commit_list *remoteheads)
339 struct rev_info rev;
340 struct strbuf out = STRBUF_INIT;
341 struct commit_list *j;
342 const char *filename;
343 int fd;
344 struct pretty_print_context ctx = {0};
346 printf(_("Squash commit -- not updating HEAD\n"));
347 filename = git_path("SQUASH_MSG");
348 fd = open(filename, O_WRONLY | O_CREAT, 0666);
349 if (fd < 0)
350 die_errno(_("Could not write to '%s'"), filename);
352 init_revisions(&rev, NULL);
353 rev.ignore_merges = 1;
354 rev.commit_format = CMIT_FMT_MEDIUM;
356 commit->object.flags |= UNINTERESTING;
357 add_pending_object(&rev, &commit->object, NULL);
359 for (j = remoteheads; j; j = j->next)
360 add_pending_object(&rev, &j->item->object, NULL);
362 setup_revisions(0, NULL, &rev, NULL);
363 if (prepare_revision_walk(&rev))
364 die(_("revision walk setup failed"));
366 ctx.abbrev = rev.abbrev;
367 ctx.date_mode = rev.date_mode;
368 ctx.fmt = rev.commit_format;
370 strbuf_addstr(&out, "Squashed commit of the following:\n");
371 while ((commit = get_revision(&rev)) != NULL) {
372 strbuf_addch(&out, '\n');
373 strbuf_addf(&out, "commit %s\n",
374 sha1_to_hex(commit->object.sha1));
375 pretty_print_commit(&ctx, commit, &out);
377 if (write(fd, out.buf, out.len) < 0)
378 die_errno(_("Writing SQUASH_MSG"));
379 if (close(fd))
380 die_errno(_("Finishing SQUASH_MSG"));
381 strbuf_release(&out);
384 static void finish(struct commit *head_commit,
385 struct commit_list *remoteheads,
386 const unsigned char *new_head, const char *msg)
388 struct strbuf reflog_message = STRBUF_INIT;
389 const unsigned char *head = head_commit->object.sha1;
391 if (!msg)
392 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
393 else {
394 if (verbosity >= 0)
395 printf("%s\n", msg);
396 strbuf_addf(&reflog_message, "%s: %s",
397 getenv("GIT_REFLOG_ACTION"), msg);
399 if (squash) {
400 squash_message(head_commit, remoteheads);
401 } else {
402 if (verbosity >= 0 && !merge_msg.len)
403 printf(_("No merge message -- not updating HEAD\n"));
404 else {
405 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
406 update_ref(reflog_message.buf, "HEAD",
407 new_head, head, 0,
408 DIE_ON_ERR);
410 * We ignore errors in 'gc --auto', since the
411 * user should see them.
413 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
416 if (new_head && show_diffstat) {
417 struct diff_options opts;
418 diff_setup(&opts);
419 opts.stat_width = -1; /* use full terminal width */
420 opts.stat_graph_width = -1; /* respect statGraphWidth config */
421 opts.output_format |=
422 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
423 opts.detect_rename = DIFF_DETECT_RENAME;
424 diff_setup_done(&opts);
425 diff_tree_sha1(head, new_head, "", &opts);
426 diffcore_std(&opts);
427 diff_flush(&opts);
430 /* Run a post-merge hook */
431 run_hook(NULL, "post-merge", squash ? "1" : "0", NULL);
433 strbuf_release(&reflog_message);
436 /* Get the name for the merge commit's message. */
437 static void merge_name(const char *remote, struct strbuf *msg)
439 struct commit *remote_head;
440 unsigned char branch_head[20];
441 struct strbuf buf = STRBUF_INIT;
442 struct strbuf bname = STRBUF_INIT;
443 const char *ptr;
444 char *found_ref;
445 int len, early;
447 strbuf_branchname(&bname, remote);
448 remote = bname.buf;
450 memset(branch_head, 0, sizeof(branch_head));
451 remote_head = get_merge_parent(remote);
452 if (!remote_head)
453 die(_("'%s' does not point to a commit"), remote);
455 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
456 if (!prefixcmp(found_ref, "refs/heads/")) {
457 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
458 sha1_to_hex(branch_head), remote);
459 goto cleanup;
461 if (!prefixcmp(found_ref, "refs/tags/")) {
462 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
463 sha1_to_hex(branch_head), remote);
464 goto cleanup;
466 if (!prefixcmp(found_ref, "refs/remotes/")) {
467 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
468 sha1_to_hex(branch_head), remote);
469 goto cleanup;
473 /* See if remote matches <name>^^^.. or <name>~<number> */
474 for (len = 0, ptr = remote + strlen(remote);
475 remote < ptr && ptr[-1] == '^';
476 ptr--)
477 len++;
478 if (len)
479 early = 1;
480 else {
481 early = 0;
482 ptr = strrchr(remote, '~');
483 if (ptr) {
484 int seen_nonzero = 0;
486 len++; /* count ~ */
487 while (*++ptr && isdigit(*ptr)) {
488 seen_nonzero |= (*ptr != '0');
489 len++;
491 if (*ptr)
492 len = 0; /* not ...~<number> */
493 else if (seen_nonzero)
494 early = 1;
495 else if (len == 1)
496 early = 1; /* "name~" is "name~1"! */
499 if (len) {
500 struct strbuf truname = STRBUF_INIT;
501 strbuf_addstr(&truname, "refs/heads/");
502 strbuf_addstr(&truname, remote);
503 strbuf_setlen(&truname, truname.len - len);
504 if (ref_exists(truname.buf)) {
505 strbuf_addf(msg,
506 "%s\t\tbranch '%s'%s of .\n",
507 sha1_to_hex(remote_head->object.sha1),
508 truname.buf + 11,
509 (early ? " (early part)" : ""));
510 strbuf_release(&truname);
511 goto cleanup;
515 if (!strcmp(remote, "FETCH_HEAD") &&
516 !access(git_path("FETCH_HEAD"), R_OK)) {
517 const char *filename;
518 FILE *fp;
519 struct strbuf line = STRBUF_INIT;
520 char *ptr;
522 filename = git_path("FETCH_HEAD");
523 fp = fopen(filename, "r");
524 if (!fp)
525 die_errno(_("could not open '%s' for reading"),
526 filename);
527 strbuf_getline(&line, fp, '\n');
528 fclose(fp);
529 ptr = strstr(line.buf, "\tnot-for-merge\t");
530 if (ptr)
531 strbuf_remove(&line, ptr-line.buf+1, 13);
532 strbuf_addbuf(msg, &line);
533 strbuf_release(&line);
534 goto cleanup;
537 if (remote_head->util) {
538 struct merge_remote_desc *desc;
539 desc = merge_remote_util(remote_head);
540 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
541 strbuf_addf(msg, "%s\t\t%s '%s'\n",
542 sha1_to_hex(desc->obj->sha1),
543 typename(desc->obj->type),
544 remote);
545 goto cleanup;
549 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
550 sha1_to_hex(remote_head->object.sha1), remote);
551 cleanup:
552 strbuf_release(&buf);
553 strbuf_release(&bname);
556 static void parse_branch_merge_options(char *bmo)
558 const char **argv;
559 int argc;
561 if (!bmo)
562 return;
563 argc = split_cmdline(bmo, &argv);
564 if (argc < 0)
565 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
566 split_cmdline_strerror(argc));
567 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
568 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
569 argc++;
570 argv[0] = "branch.*.mergeoptions";
571 parse_options(argc, argv, NULL, builtin_merge_options,
572 builtin_merge_usage, 0);
573 free(argv);
576 static int git_merge_config(const char *k, const char *v, void *cb)
578 int status;
580 if (branch && !prefixcmp(k, "branch.") &&
581 !prefixcmp(k + 7, branch) &&
582 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
583 free(branch_mergeoptions);
584 branch_mergeoptions = xstrdup(v);
585 return 0;
588 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
589 show_diffstat = git_config_bool(k, v);
590 else if (!strcmp(k, "pull.twohead"))
591 return git_config_string(&pull_twohead, k, v);
592 else if (!strcmp(k, "pull.octopus"))
593 return git_config_string(&pull_octopus, k, v);
594 else if (!strcmp(k, "merge.renormalize"))
595 option_renormalize = git_config_bool(k, v);
596 else if (!strcmp(k, "merge.ff")) {
597 int boolval = git_config_maybe_bool(k, v);
598 if (0 <= boolval) {
599 fast_forward = boolval ? FF_ALLOW : FF_NO;
600 } else if (v && !strcmp(v, "only")) {
601 fast_forward = FF_ONLY;
602 } /* do not barf on values from future versions of git */
603 return 0;
604 } else if (!strcmp(k, "merge.defaulttoupstream")) {
605 default_to_upstream = git_config_bool(k, v);
606 return 0;
609 status = fmt_merge_msg_config(k, v, cb);
610 if (status)
611 return status;
612 status = git_gpg_config(k, v, NULL);
613 if (status)
614 return status;
615 return git_diff_ui_config(k, v, cb);
618 static int read_tree_trivial(unsigned char *common, unsigned char *head,
619 unsigned char *one)
621 int i, nr_trees = 0;
622 struct tree *trees[MAX_UNPACK_TREES];
623 struct tree_desc t[MAX_UNPACK_TREES];
624 struct unpack_trees_options opts;
626 memset(&opts, 0, sizeof(opts));
627 opts.head_idx = 2;
628 opts.src_index = &the_index;
629 opts.dst_index = &the_index;
630 opts.update = 1;
631 opts.verbose_update = 1;
632 opts.trivial_merges_only = 1;
633 opts.merge = 1;
634 trees[nr_trees] = parse_tree_indirect(common);
635 if (!trees[nr_trees++])
636 return -1;
637 trees[nr_trees] = parse_tree_indirect(head);
638 if (!trees[nr_trees++])
639 return -1;
640 trees[nr_trees] = parse_tree_indirect(one);
641 if (!trees[nr_trees++])
642 return -1;
643 opts.fn = threeway_merge;
644 cache_tree_free(&active_cache_tree);
645 for (i = 0; i < nr_trees; i++) {
646 parse_tree(trees[i]);
647 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
649 if (unpack_trees(nr_trees, t, &opts))
650 return -1;
651 return 0;
654 static void write_tree_trivial(unsigned char *sha1)
656 if (write_cache_as_tree(sha1, 0, NULL))
657 die(_("git write-tree failed to write a tree"));
660 static int try_merge_strategy(const char *strategy, struct commit_list *common,
661 struct commit_list *remoteheads,
662 struct commit *head, const char *head_arg)
664 int index_fd;
665 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
667 index_fd = hold_locked_index(lock, 1);
668 refresh_cache(REFRESH_QUIET);
669 if (active_cache_changed &&
670 (write_cache(index_fd, active_cache, active_nr) ||
671 commit_locked_index(lock)))
672 return error(_("Unable to write index."));
673 rollback_lock_file(lock);
675 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
676 int clean, x;
677 struct commit *result;
678 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
679 int index_fd;
680 struct commit_list *reversed = NULL;
681 struct merge_options o;
682 struct commit_list *j;
684 if (remoteheads->next) {
685 error(_("Not handling anything other than two heads merge."));
686 return 2;
689 init_merge_options(&o);
690 if (!strcmp(strategy, "subtree"))
691 o.subtree_shift = "";
693 o.renormalize = option_renormalize;
694 o.show_rename_progress =
695 show_progress == -1 ? isatty(2) : show_progress;
697 for (x = 0; x < xopts_nr; x++)
698 if (parse_merge_opt(&o, xopts[x]))
699 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
701 o.branch1 = head_arg;
702 o.branch2 = merge_remote_util(remoteheads->item)->name;
704 for (j = common; j; j = j->next)
705 commit_list_insert(j->item, &reversed);
707 index_fd = hold_locked_index(lock, 1);
708 clean = merge_recursive(&o, head,
709 remoteheads->item, reversed, &result);
710 if (active_cache_changed &&
711 (write_cache(index_fd, active_cache, active_nr) ||
712 commit_locked_index(lock)))
713 die (_("unable to write %s"), get_index_file());
714 rollback_lock_file(lock);
715 return clean ? 0 : 1;
716 } else {
717 return try_merge_command(strategy, xopts_nr, xopts,
718 common, head_arg, remoteheads);
722 static void count_diff_files(struct diff_queue_struct *q,
723 struct diff_options *opt, void *data)
725 int *count = data;
727 (*count) += q->nr;
730 static int count_unmerged_entries(void)
732 int i, ret = 0;
734 for (i = 0; i < active_nr; i++)
735 if (ce_stage(active_cache[i]))
736 ret++;
738 return ret;
741 static void split_merge_strategies(const char *string, struct strategy **list,
742 int *nr, int *alloc)
744 char *p, *q, *buf;
746 if (!string)
747 return;
749 buf = xstrdup(string);
750 q = buf;
751 for (;;) {
752 p = strchr(q, ' ');
753 if (!p) {
754 ALLOC_GROW(*list, *nr + 1, *alloc);
755 (*list)[(*nr)++].name = xstrdup(q);
756 free(buf);
757 return;
758 } else {
759 *p = '\0';
760 ALLOC_GROW(*list, *nr + 1, *alloc);
761 (*list)[(*nr)++].name = xstrdup(q);
762 q = ++p;
767 static void add_strategies(const char *string, unsigned attr)
769 struct strategy *list = NULL;
770 int list_alloc = 0, list_nr = 0, i;
772 memset(&list, 0, sizeof(list));
773 split_merge_strategies(string, &list, &list_nr, &list_alloc);
774 if (list) {
775 for (i = 0; i < list_nr; i++)
776 append_strategy(get_strategy(list[i].name));
777 return;
779 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
780 if (all_strategy[i].attr & attr)
781 append_strategy(&all_strategy[i]);
785 static void write_merge_msg(struct strbuf *msg)
787 const char *filename = git_path("MERGE_MSG");
788 int fd = open(filename, O_WRONLY | O_CREAT, 0666);
789 if (fd < 0)
790 die_errno(_("Could not open '%s' for writing"),
791 filename);
792 if (write_in_full(fd, msg->buf, msg->len) != msg->len)
793 die_errno(_("Could not write to '%s'"), filename);
794 close(fd);
797 static void read_merge_msg(struct strbuf *msg)
799 const char *filename = git_path("MERGE_MSG");
800 strbuf_reset(msg);
801 if (strbuf_read_file(msg, filename, 0) < 0)
802 die_errno(_("Could not read from '%s'"), filename);
805 static void write_merge_state(struct commit_list *);
806 static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
808 if (err_msg)
809 error("%s", err_msg);
810 fprintf(stderr,
811 _("Not committing merge; use 'git commit' to complete the merge.\n"));
812 write_merge_state(remoteheads);
813 exit(1);
816 static const char merge_editor_comment[] =
817 N_("Please enter a commit message to explain why this merge is necessary,\n"
818 "especially if it merges an updated upstream into a topic branch.\n"
819 "\n"
820 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
821 "the commit.\n");
823 static void prepare_to_commit(struct commit_list *remoteheads)
825 struct strbuf msg = STRBUF_INIT;
826 strbuf_addbuf(&msg, &merge_msg);
827 strbuf_addch(&msg, '\n');
828 if (0 < option_edit)
829 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
830 write_merge_msg(&msg);
831 if (run_hook(get_index_file(), "prepare-commit-msg",
832 git_path("MERGE_MSG"), "merge", NULL, NULL))
833 abort_commit(remoteheads, NULL);
834 if (0 < option_edit) {
835 if (launch_editor(git_path("MERGE_MSG"), NULL, NULL))
836 abort_commit(remoteheads, NULL);
838 read_merge_msg(&msg);
839 stripspace(&msg, 0 < option_edit);
840 if (!msg.len)
841 abort_commit(remoteheads, _("Empty commit message."));
842 strbuf_release(&merge_msg);
843 strbuf_addbuf(&merge_msg, &msg);
844 strbuf_release(&msg);
847 static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
849 unsigned char result_tree[20], result_commit[20];
850 struct commit_list *parent = xmalloc(sizeof(*parent));
852 write_tree_trivial(result_tree);
853 printf(_("Wonderful.\n"));
854 parent->item = head;
855 parent->next = xmalloc(sizeof(*parent->next));
856 parent->next->item = remoteheads->item;
857 parent->next->next = NULL;
858 prepare_to_commit(remoteheads);
859 if (commit_tree(&merge_msg, result_tree, parent, result_commit, NULL,
860 sign_commit))
861 die(_("failed to write commit object"));
862 finish(head, remoteheads, result_commit, "In-index merge");
863 drop_save();
864 return 0;
867 static int finish_automerge(struct commit *head,
868 int head_subsumed,
869 struct commit_list *common,
870 struct commit_list *remoteheads,
871 unsigned char *result_tree,
872 const char *wt_strategy)
874 struct commit_list *parents = NULL;
875 struct strbuf buf = STRBUF_INIT;
876 unsigned char result_commit[20];
878 free_commit_list(common);
879 parents = remoteheads;
880 if (!head_subsumed || fast_forward == FF_NO)
881 commit_list_insert(head, &parents);
882 strbuf_addch(&merge_msg, '\n');
883 prepare_to_commit(remoteheads);
884 if (commit_tree(&merge_msg, result_tree, parents, result_commit,
885 NULL, sign_commit))
886 die(_("failed to write commit object"));
887 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
888 finish(head, remoteheads, result_commit, buf.buf);
889 strbuf_release(&buf);
890 drop_save();
891 return 0;
894 static int suggest_conflicts(int renormalizing)
896 const char *filename;
897 FILE *fp;
898 int pos;
900 filename = git_path("MERGE_MSG");
901 fp = fopen(filename, "a");
902 if (!fp)
903 die_errno(_("Could not open '%s' for writing"), filename);
904 fprintf(fp, "\nConflicts:\n");
905 for (pos = 0; pos < active_nr; pos++) {
906 const struct cache_entry *ce = active_cache[pos];
908 if (ce_stage(ce)) {
909 fprintf(fp, "\t%s\n", ce->name);
910 while (pos + 1 < active_nr &&
911 !strcmp(ce->name,
912 active_cache[pos + 1]->name))
913 pos++;
916 fclose(fp);
917 rerere(allow_rerere_auto);
918 printf(_("Automatic merge failed; "
919 "fix conflicts and then commit the result.\n"));
920 return 1;
923 static struct commit *is_old_style_invocation(int argc, const char **argv,
924 const unsigned char *head)
926 struct commit *second_token = NULL;
927 if (argc > 2) {
928 unsigned char second_sha1[20];
930 if (get_sha1(argv[1], second_sha1))
931 return NULL;
932 second_token = lookup_commit_reference_gently(second_sha1, 0);
933 if (!second_token)
934 die(_("'%s' is not a commit"), argv[1]);
935 if (hashcmp(second_token->object.sha1, head))
936 return NULL;
938 return second_token;
941 static int evaluate_result(void)
943 int cnt = 0;
944 struct rev_info rev;
946 /* Check how many files differ. */
947 init_revisions(&rev, "");
948 setup_revisions(0, NULL, &rev, NULL);
949 rev.diffopt.output_format |=
950 DIFF_FORMAT_CALLBACK;
951 rev.diffopt.format_callback = count_diff_files;
952 rev.diffopt.format_callback_data = &cnt;
953 run_diff_files(&rev, 0);
956 * Check how many unmerged entries are
957 * there.
959 cnt += count_unmerged_entries();
961 return cnt;
965 * Pretend as if the user told us to merge with the remote-tracking
966 * branch we have for the upstream of the current branch
968 static int setup_with_upstream(const char ***argv)
970 struct branch *branch = branch_get(NULL);
971 int i;
972 const char **args;
974 if (!branch)
975 die(_("No current branch."));
976 if (!branch->remote)
977 die(_("No remote for the current branch."));
978 if (!branch->merge_nr)
979 die(_("No default upstream defined for the current branch."));
981 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
982 for (i = 0; i < branch->merge_nr; i++) {
983 if (!branch->merge[i]->dst)
984 die(_("No remote-tracking branch for %s from %s"),
985 branch->merge[i]->src, branch->remote_name);
986 args[i] = branch->merge[i]->dst;
988 args[i] = NULL;
989 *argv = args;
990 return i;
993 static void write_merge_state(struct commit_list *remoteheads)
995 const char *filename;
996 int fd;
997 struct commit_list *j;
998 struct strbuf buf = STRBUF_INIT;
1000 for (j = remoteheads; j; j = j->next) {
1001 unsigned const char *sha1;
1002 struct commit *c = j->item;
1003 if (c->util && merge_remote_util(c)->obj) {
1004 sha1 = merge_remote_util(c)->obj->sha1;
1005 } else {
1006 sha1 = c->object.sha1;
1008 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
1010 filename = git_path("MERGE_HEAD");
1011 fd = open(filename, O_WRONLY | O_CREAT, 0666);
1012 if (fd < 0)
1013 die_errno(_("Could not open '%s' for writing"), filename);
1014 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1015 die_errno(_("Could not write to '%s'"), filename);
1016 close(fd);
1017 strbuf_addch(&merge_msg, '\n');
1018 write_merge_msg(&merge_msg);
1020 filename = git_path("MERGE_MODE");
1021 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
1022 if (fd < 0)
1023 die_errno(_("Could not open '%s' for writing"), filename);
1024 strbuf_reset(&buf);
1025 if (fast_forward == FF_NO)
1026 strbuf_addf(&buf, "no-ff");
1027 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1028 die_errno(_("Could not write to '%s'"), filename);
1029 close(fd);
1032 static int default_edit_option(void)
1034 static const char name[] = "GIT_MERGE_AUTOEDIT";
1035 const char *e = getenv(name);
1036 struct stat st_stdin, st_stdout;
1038 if (have_message)
1039 /* an explicit -m msg without --[no-]edit */
1040 return 0;
1042 if (e) {
1043 int v = git_config_maybe_bool(name, e);
1044 if (v < 0)
1045 die("Bad value '%s' in environment '%s'", e, name);
1046 return v;
1049 /* Use editor if stdin and stdout are the same and is a tty */
1050 return (!fstat(0, &st_stdin) &&
1051 !fstat(1, &st_stdout) &&
1052 isatty(0) && isatty(1) &&
1053 st_stdin.st_dev == st_stdout.st_dev &&
1054 st_stdin.st_ino == st_stdout.st_ino &&
1055 st_stdin.st_mode == st_stdout.st_mode);
1058 static struct commit_list *collect_parents(struct commit *head_commit,
1059 int *head_subsumed,
1060 int argc, const char **argv)
1062 int i;
1063 struct commit_list *remoteheads = NULL, *parents, *next;
1064 struct commit_list **remotes = &remoteheads;
1066 if (head_commit)
1067 remotes = &commit_list_insert(head_commit, remotes)->next;
1068 for (i = 0; i < argc; i++) {
1069 struct commit *commit = get_merge_parent(argv[i]);
1070 if (!commit)
1071 help_unknown_ref(argv[i], "merge",
1072 "not something we can merge");
1073 remotes = &commit_list_insert(commit, remotes)->next;
1075 *remotes = NULL;
1077 parents = reduce_heads(remoteheads);
1079 *head_subsumed = 1; /* we will flip this to 0 when we find it */
1080 for (remoteheads = NULL, remotes = &remoteheads;
1081 parents;
1082 parents = next) {
1083 struct commit *commit = parents->item;
1084 next = parents->next;
1085 if (commit == head_commit)
1086 *head_subsumed = 0;
1087 else
1088 remotes = &commit_list_insert(commit, remotes)->next;
1090 return remoteheads;
1093 int cmd_merge(int argc, const char **argv, const char *prefix)
1095 unsigned char result_tree[20];
1096 unsigned char stash[20];
1097 unsigned char head_sha1[20];
1098 struct commit *head_commit;
1099 struct strbuf buf = STRBUF_INIT;
1100 const char *head_arg;
1101 int flag, i, ret = 0, head_subsumed;
1102 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1103 struct commit_list *common = NULL;
1104 const char *best_strategy = NULL, *wt_strategy = NULL;
1105 struct commit_list *remoteheads, *p;
1106 void *branch_to_free;
1108 if (argc == 2 && !strcmp(argv[1], "-h"))
1109 usage_with_options(builtin_merge_usage, builtin_merge_options);
1112 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1113 * current branch.
1115 branch = branch_to_free = resolve_refdup("HEAD", head_sha1, 0, &flag);
1116 if (branch && !prefixcmp(branch, "refs/heads/"))
1117 branch += 11;
1118 if (!branch || is_null_sha1(head_sha1))
1119 head_commit = NULL;
1120 else
1121 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1123 git_config(git_merge_config, NULL);
1125 if (branch_mergeoptions)
1126 parse_branch_merge_options(branch_mergeoptions);
1127 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1128 builtin_merge_usage, 0);
1129 if (shortlog_len < 0)
1130 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1132 if (verbosity < 0 && show_progress == -1)
1133 show_progress = 0;
1135 if (abort_current_merge) {
1136 int nargc = 2;
1137 const char *nargv[] = {"reset", "--merge", NULL};
1139 if (!file_exists(git_path("MERGE_HEAD")))
1140 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1142 /* Invoke 'git reset --merge' */
1143 ret = cmd_reset(nargc, nargv, prefix);
1144 goto done;
1147 if (read_cache_unmerged())
1148 die_resolve_conflict("merge");
1150 if (file_exists(git_path("MERGE_HEAD"))) {
1152 * There is no unmerged entry, don't advise 'git
1153 * add/rm <file>', just 'git commit'.
1155 if (advice_resolve_conflict)
1156 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1157 "Please, commit your changes before you can merge."));
1158 else
1159 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1161 if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
1162 if (advice_resolve_conflict)
1163 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1164 "Please, commit your changes before you can merge."));
1165 else
1166 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1168 resolve_undo_clear();
1170 if (verbosity < 0)
1171 show_diffstat = 0;
1173 if (squash) {
1174 if (fast_forward == FF_NO)
1175 die(_("You cannot combine --squash with --no-ff."));
1176 option_commit = 0;
1179 if (!abort_current_merge) {
1180 if (!argc) {
1181 if (default_to_upstream)
1182 argc = setup_with_upstream(&argv);
1183 else
1184 die(_("No commit specified and merge.defaultToUpstream not set."));
1185 } else if (argc == 1 && !strcmp(argv[0], "-"))
1186 argv[0] = "@{-1}";
1188 if (!argc)
1189 usage_with_options(builtin_merge_usage,
1190 builtin_merge_options);
1193 * This could be traditional "merge <msg> HEAD <commit>..." and
1194 * the way we can tell it is to see if the second token is HEAD,
1195 * but some people might have misused the interface and used a
1196 * committish that is the same as HEAD there instead.
1197 * Traditional format never would have "-m" so it is an
1198 * additional safety measure to check for it.
1201 if (!have_message && head_commit &&
1202 is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
1203 strbuf_addstr(&merge_msg, argv[0]);
1204 head_arg = argv[1];
1205 argv += 2;
1206 argc -= 2;
1207 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1208 } else if (!head_commit) {
1209 struct commit *remote_head;
1211 * If the merged head is a valid one there is no reason
1212 * to forbid "git merge" into a branch yet to be born.
1213 * We do the same for "git pull".
1215 if (argc != 1)
1216 die(_("Can merge only exactly one commit into "
1217 "empty head"));
1218 if (squash)
1219 die(_("Squash commit into empty head not supported yet"));
1220 if (fast_forward == FF_NO)
1221 die(_("Non-fast-forward commit does not make sense into "
1222 "an empty head"));
1223 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1224 remote_head = remoteheads->item;
1225 if (!remote_head)
1226 die(_("%s - not something we can merge"), argv[0]);
1227 read_empty(remote_head->object.sha1, 0);
1228 update_ref("initial pull", "HEAD", remote_head->object.sha1,
1229 NULL, 0, DIE_ON_ERR);
1230 goto done;
1231 } else {
1232 struct strbuf merge_names = STRBUF_INIT;
1234 /* We are invoked directly as the first-class UI. */
1235 head_arg = "HEAD";
1238 * All the rest are the commits being merged; prepare
1239 * the standard merge summary message to be appended
1240 * to the given message.
1242 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1243 for (p = remoteheads; p; p = p->next)
1244 merge_name(merge_remote_util(p->item)->name, &merge_names);
1246 if (!have_message || shortlog_len) {
1247 struct fmt_merge_msg_opts opts;
1248 memset(&opts, 0, sizeof(opts));
1249 opts.add_title = !have_message;
1250 opts.shortlog_len = shortlog_len;
1251 opts.credit_people = (0 < option_edit);
1253 fmt_merge_msg(&merge_names, &merge_msg, &opts);
1254 if (merge_msg.len)
1255 strbuf_setlen(&merge_msg, merge_msg.len - 1);
1259 if (!head_commit || !argc)
1260 usage_with_options(builtin_merge_usage,
1261 builtin_merge_options);
1263 if (verify_signatures) {
1264 for (p = remoteheads; p; p = p->next) {
1265 struct commit *commit = p->item;
1266 char hex[41];
1267 struct signature_check signature_check;
1268 memset(&signature_check, 0, sizeof(signature_check));
1270 check_commit_signature(commit, &signature_check);
1272 strcpy(hex, find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
1273 switch (signature_check.result) {
1274 case 'G':
1275 break;
1276 case 'U':
1277 die(_("Commit %s has an untrusted GPG signature, "
1278 "allegedly by %s."), hex, signature_check.signer);
1279 case 'B':
1280 die(_("Commit %s has a bad GPG signature "
1281 "allegedly by %s."), hex, signature_check.signer);
1282 default: /* 'N' */
1283 die(_("Commit %s does not have a GPG signature."), hex);
1285 if (verbosity >= 0 && signature_check.result == 'G')
1286 printf(_("Commit %s has a good GPG signature by %s\n"),
1287 hex, signature_check.signer);
1289 free(signature_check.gpg_output);
1290 free(signature_check.gpg_status);
1291 free(signature_check.signer);
1292 free(signature_check.key);
1296 strbuf_addstr(&buf, "merge");
1297 for (p = remoteheads; p; p = p->next)
1298 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1299 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1300 strbuf_reset(&buf);
1302 for (p = remoteheads; p; p = p->next) {
1303 struct commit *commit = p->item;
1304 strbuf_addf(&buf, "GITHEAD_%s",
1305 sha1_to_hex(commit->object.sha1));
1306 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1307 strbuf_reset(&buf);
1308 if (fast_forward != FF_ONLY &&
1309 merge_remote_util(commit) &&
1310 merge_remote_util(commit)->obj &&
1311 merge_remote_util(commit)->obj->type == OBJ_TAG)
1312 fast_forward = FF_NO;
1315 if (option_edit < 0)
1316 option_edit = default_edit_option();
1318 if (!use_strategies) {
1319 if (!remoteheads)
1320 ; /* already up-to-date */
1321 else if (!remoteheads->next)
1322 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1323 else
1324 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1327 for (i = 0; i < use_strategies_nr; i++) {
1328 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1329 fast_forward = FF_NO;
1330 if (use_strategies[i]->attr & NO_TRIVIAL)
1331 allow_trivial = 0;
1334 if (!remoteheads)
1335 ; /* already up-to-date */
1336 else if (!remoteheads->next)
1337 common = get_merge_bases(head_commit, remoteheads->item, 1);
1338 else {
1339 struct commit_list *list = remoteheads;
1340 commit_list_insert(head_commit, &list);
1341 common = get_octopus_merge_bases(list);
1342 free(list);
1345 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
1346 NULL, 0, DIE_ON_ERR);
1348 if (remoteheads && !common)
1349 ; /* No common ancestors found. We need a real merge. */
1350 else if (!remoteheads ||
1351 (!remoteheads->next && !common->next &&
1352 common->item == remoteheads->item)) {
1354 * If head can reach all the merge then we are up to date.
1355 * but first the most common case of merging one remote.
1357 finish_up_to_date("Already up-to-date.");
1358 goto done;
1359 } else if (fast_forward != FF_NO && !remoteheads->next &&
1360 !common->next &&
1361 !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
1362 /* Again the most common case of merging one remote. */
1363 struct strbuf msg = STRBUF_INIT;
1364 struct commit *commit;
1365 char hex[41];
1367 strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
1369 if (verbosity >= 0)
1370 printf(_("Updating %s..%s\n"),
1371 hex,
1372 find_unique_abbrev(remoteheads->item->object.sha1,
1373 DEFAULT_ABBREV));
1374 strbuf_addstr(&msg, "Fast-forward");
1375 if (have_message)
1376 strbuf_addstr(&msg,
1377 " (no commit created; -m option ignored)");
1378 commit = remoteheads->item;
1379 if (!commit) {
1380 ret = 1;
1381 goto done;
1384 if (checkout_fast_forward(head_commit->object.sha1,
1385 commit->object.sha1,
1386 overwrite_ignore)) {
1387 ret = 1;
1388 goto done;
1391 finish(head_commit, remoteheads, commit->object.sha1, msg.buf);
1392 drop_save();
1393 goto done;
1394 } else if (!remoteheads->next && common->next)
1397 * We are not doing octopus and not fast-forward. Need
1398 * a real merge.
1400 else if (!remoteheads->next && !common->next && option_commit) {
1402 * We are not doing octopus, not fast-forward, and have
1403 * only one common.
1405 refresh_cache(REFRESH_QUIET);
1406 if (allow_trivial && fast_forward != FF_ONLY) {
1407 /* See if it is really trivial. */
1408 git_committer_info(IDENT_STRICT);
1409 printf(_("Trying really trivial in-index merge...\n"));
1410 if (!read_tree_trivial(common->item->object.sha1,
1411 head_commit->object.sha1,
1412 remoteheads->item->object.sha1)) {
1413 ret = merge_trivial(head_commit, remoteheads);
1414 goto done;
1416 printf(_("Nope.\n"));
1418 } else {
1420 * An octopus. If we can reach all the remote we are up
1421 * to date.
1423 int up_to_date = 1;
1424 struct commit_list *j;
1426 for (j = remoteheads; j; j = j->next) {
1427 struct commit_list *common_one;
1430 * Here we *have* to calculate the individual
1431 * merge_bases again, otherwise "git merge HEAD^
1432 * HEAD^^" would be missed.
1434 common_one = get_merge_bases(head_commit, j->item, 1);
1435 if (hashcmp(common_one->item->object.sha1,
1436 j->item->object.sha1)) {
1437 up_to_date = 0;
1438 break;
1441 if (up_to_date) {
1442 finish_up_to_date("Already up-to-date. Yeeah!");
1443 goto done;
1447 if (fast_forward == FF_ONLY)
1448 die(_("Not possible to fast-forward, aborting."));
1450 /* We are going to make a new commit. */
1451 git_committer_info(IDENT_STRICT);
1454 * At this point, we need a real merge. No matter what strategy
1455 * we use, it would operate on the index, possibly affecting the
1456 * working tree, and when resolved cleanly, have the desired
1457 * tree in the index -- this means that the index must be in
1458 * sync with the head commit. The strategies are responsible
1459 * to ensure this.
1461 if (use_strategies_nr == 1 ||
1463 * Stash away the local changes so that we can try more than one.
1465 save_state(stash))
1466 hashcpy(stash, null_sha1);
1468 for (i = 0; i < use_strategies_nr; i++) {
1469 int ret;
1470 if (i) {
1471 printf(_("Rewinding the tree to pristine...\n"));
1472 restore_state(head_commit->object.sha1, stash);
1474 if (use_strategies_nr != 1)
1475 printf(_("Trying merge strategy %s...\n"),
1476 use_strategies[i]->name);
1478 * Remember which strategy left the state in the working
1479 * tree.
1481 wt_strategy = use_strategies[i]->name;
1483 ret = try_merge_strategy(use_strategies[i]->name,
1484 common, remoteheads,
1485 head_commit, head_arg);
1486 if (!option_commit && !ret) {
1487 merge_was_ok = 1;
1489 * This is necessary here just to avoid writing
1490 * the tree, but later we will *not* exit with
1491 * status code 1 because merge_was_ok is set.
1493 ret = 1;
1496 if (ret) {
1498 * The backend exits with 1 when conflicts are
1499 * left to be resolved, with 2 when it does not
1500 * handle the given merge at all.
1502 if (ret == 1) {
1503 int cnt = evaluate_result();
1505 if (best_cnt <= 0 || cnt <= best_cnt) {
1506 best_strategy = use_strategies[i]->name;
1507 best_cnt = cnt;
1510 if (merge_was_ok)
1511 break;
1512 else
1513 continue;
1516 /* Automerge succeeded. */
1517 write_tree_trivial(result_tree);
1518 automerge_was_ok = 1;
1519 break;
1523 * If we have a resulting tree, that means the strategy module
1524 * auto resolved the merge cleanly.
1526 if (automerge_was_ok) {
1527 ret = finish_automerge(head_commit, head_subsumed,
1528 common, remoteheads,
1529 result_tree, wt_strategy);
1530 goto done;
1534 * Pick the result from the best strategy and have the user fix
1535 * it up.
1537 if (!best_strategy) {
1538 restore_state(head_commit->object.sha1, stash);
1539 if (use_strategies_nr > 1)
1540 fprintf(stderr,
1541 _("No merge strategy handled the merge.\n"));
1542 else
1543 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1544 use_strategies[0]->name);
1545 ret = 2;
1546 goto done;
1547 } else if (best_strategy == wt_strategy)
1548 ; /* We already have its result in the working tree. */
1549 else {
1550 printf(_("Rewinding the tree to pristine...\n"));
1551 restore_state(head_commit->object.sha1, stash);
1552 printf(_("Using the %s to prepare resolving by hand.\n"),
1553 best_strategy);
1554 try_merge_strategy(best_strategy, common, remoteheads,
1555 head_commit, head_arg);
1558 if (squash)
1559 finish(head_commit, remoteheads, NULL, NULL);
1560 else
1561 write_merge_state(remoteheads);
1563 if (merge_was_ok)
1564 fprintf(stderr, _("Automatic merge went well; "
1565 "stopped before committing as requested\n"));
1566 else
1567 ret = suggest_conflicts(option_renormalize);
1569 done:
1570 free(branch_to_free);
1571 return ret;