t/test-lib: introduce --chain-lint option
[git/debian.git] / builtin / merge.c
blob3b0f8f96d4168463139d15f1cde655facc73426c
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 "lockfile.h"
13 #include "run-command.h"
14 #include "diff.h"
15 #include "refs.h"
16 #include "commit.h"
17 #include "diffcore.h"
18 #include "revision.h"
19 #include "unpack-trees.h"
20 #include "cache-tree.h"
21 #include "dir.h"
22 #include "utf8.h"
23 #include "log-tree.h"
24 #include "color.h"
25 #include "rerere.h"
26 #include "help.h"
27 #include "merge-recursive.h"
28 #include "resolve-undo.h"
29 #include "remote.h"
30 #include "fmt-merge-msg.h"
31 #include "gpg-interface.h"
32 #include "sequencer.h"
34 #define DEFAULT_TWOHEAD (1<<0)
35 #define DEFAULT_OCTOPUS (1<<1)
36 #define NO_FAST_FORWARD (1<<2)
37 #define NO_TRIVIAL (1<<3)
39 struct strategy {
40 const char *name;
41 unsigned attr;
44 static const char * const builtin_merge_usage[] = {
45 N_("git merge [<options>] [<commit>...]"),
46 N_("git merge [<options>] <msg> HEAD <commit>"),
47 N_("git merge --abort"),
48 NULL
51 static int show_diffstat = 1, shortlog_len = -1, squash;
52 static int option_commit = 1;
53 static int option_edit = -1;
54 static int allow_trivial = 1, have_message, verify_signatures;
55 static int overwrite_ignore = 1;
56 static struct strbuf merge_msg = STRBUF_INIT;
57 static struct strategy **use_strategies;
58 static size_t use_strategies_nr, use_strategies_alloc;
59 static const char **xopts;
60 static size_t xopts_nr, xopts_alloc;
61 static const char *branch;
62 static char *branch_mergeoptions;
63 static int option_renormalize;
64 static int verbosity;
65 static int allow_rerere_auto;
66 static int abort_current_merge;
67 static int show_progress = -1;
68 static int default_to_upstream = 1;
69 static const char *sign_commit;
71 static struct strategy all_strategy[] = {
72 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
73 { "octopus", DEFAULT_OCTOPUS },
74 { "resolve", 0 },
75 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
76 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
79 static const char *pull_twohead, *pull_octopus;
81 enum ff_type {
82 FF_NO,
83 FF_ALLOW,
84 FF_ONLY
87 static enum ff_type fast_forward = FF_ALLOW;
89 static int option_parse_message(const struct option *opt,
90 const char *arg, int unset)
92 struct strbuf *buf = opt->value;
94 if (unset)
95 strbuf_setlen(buf, 0);
96 else if (arg) {
97 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
98 have_message = 1;
99 } else
100 return error(_("switch `m' requires a value"));
101 return 0;
104 static struct strategy *get_strategy(const char *name)
106 int i;
107 struct strategy *ret;
108 static struct cmdnames main_cmds, other_cmds;
109 static int loaded;
111 if (!name)
112 return NULL;
114 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
115 if (!strcmp(name, all_strategy[i].name))
116 return &all_strategy[i];
118 if (!loaded) {
119 struct cmdnames not_strategies;
120 loaded = 1;
122 memset(&not_strategies, 0, sizeof(struct cmdnames));
123 load_command_list("git-merge-", &main_cmds, &other_cmds);
124 for (i = 0; i < main_cmds.cnt; i++) {
125 int j, found = 0;
126 struct cmdname *ent = main_cmds.names[i];
127 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
128 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
129 && !all_strategy[j].name[ent->len])
130 found = 1;
131 if (!found)
132 add_cmdname(&not_strategies, ent->name, ent->len);
134 exclude_cmds(&main_cmds, &not_strategies);
136 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
137 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
138 fprintf(stderr, _("Available strategies are:"));
139 for (i = 0; i < main_cmds.cnt; i++)
140 fprintf(stderr, " %s", main_cmds.names[i]->name);
141 fprintf(stderr, ".\n");
142 if (other_cmds.cnt) {
143 fprintf(stderr, _("Available custom strategies are:"));
144 for (i = 0; i < other_cmds.cnt; i++)
145 fprintf(stderr, " %s", other_cmds.names[i]->name);
146 fprintf(stderr, ".\n");
148 exit(1);
151 ret = xcalloc(1, sizeof(struct strategy));
152 ret->name = xstrdup(name);
153 ret->attr = NO_TRIVIAL;
154 return ret;
157 static void append_strategy(struct strategy *s)
159 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
160 use_strategies[use_strategies_nr++] = s;
163 static int option_parse_strategy(const struct option *opt,
164 const char *name, int unset)
166 if (unset)
167 return 0;
169 append_strategy(get_strategy(name));
170 return 0;
173 static int option_parse_x(const struct option *opt,
174 const char *arg, int unset)
176 if (unset)
177 return 0;
179 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
180 xopts[xopts_nr++] = xstrdup(arg);
181 return 0;
184 static int option_parse_n(const struct option *opt,
185 const char *arg, int unset)
187 show_diffstat = unset;
188 return 0;
191 static struct option builtin_merge_options[] = {
192 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
193 N_("do not show a diffstat at the end of the merge"),
194 PARSE_OPT_NOARG, option_parse_n },
195 OPT_BOOL(0, "stat", &show_diffstat,
196 N_("show a diffstat at the end of the merge")),
197 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
198 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
199 N_("add (at most <n>) entries from shortlog to merge commit message"),
200 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
201 OPT_BOOL(0, "squash", &squash,
202 N_("create a single commit instead of doing a merge")),
203 OPT_BOOL(0, "commit", &option_commit,
204 N_("perform a commit if the merge succeeds (default)")),
205 OPT_BOOL('e', "edit", &option_edit,
206 N_("edit message before committing")),
207 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
208 { OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
209 N_("abort if fast-forward is not possible"),
210 PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
211 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
212 OPT_BOOL(0, "verify-signatures", &verify_signatures,
213 N_("Verify that the named commit has a valid GPG signature")),
214 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
215 N_("merge strategy to use"), option_parse_strategy),
216 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
217 N_("option for selected merge strategy"), option_parse_x),
218 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
219 N_("merge commit message (for a non-fast-forward merge)"),
220 option_parse_message),
221 OPT__VERBOSITY(&verbosity),
222 OPT_BOOL(0, "abort", &abort_current_merge,
223 N_("abort the current in-progress merge")),
224 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
225 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
226 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
227 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
228 OPT_END()
231 /* Cleans up metadata that is uninteresting after a succeeded merge. */
232 static void drop_save(void)
234 unlink(git_path("MERGE_HEAD"));
235 unlink(git_path("MERGE_MSG"));
236 unlink(git_path("MERGE_MODE"));
239 static int save_state(unsigned char *stash)
241 int len;
242 struct child_process cp = CHILD_PROCESS_INIT;
243 struct strbuf buffer = STRBUF_INIT;
244 const char *argv[] = {"stash", "create", NULL};
246 cp.argv = argv;
247 cp.out = -1;
248 cp.git_cmd = 1;
250 if (start_command(&cp))
251 die(_("could not run stash."));
252 len = strbuf_read(&buffer, cp.out, 1024);
253 close(cp.out);
255 if (finish_command(&cp) || len < 0)
256 die(_("stash failed"));
257 else if (!len) /* no changes */
258 return -1;
259 strbuf_setlen(&buffer, buffer.len-1);
260 if (get_sha1(buffer.buf, stash))
261 die(_("not a valid object: %s"), buffer.buf);
262 return 0;
265 static void read_empty(unsigned const char *sha1, int verbose)
267 int i = 0;
268 const char *args[7];
270 args[i++] = "read-tree";
271 if (verbose)
272 args[i++] = "-v";
273 args[i++] = "-m";
274 args[i++] = "-u";
275 args[i++] = EMPTY_TREE_SHA1_HEX;
276 args[i++] = sha1_to_hex(sha1);
277 args[i] = NULL;
279 if (run_command_v_opt(args, RUN_GIT_CMD))
280 die(_("read-tree failed"));
283 static void reset_hard(unsigned const char *sha1, int verbose)
285 int i = 0;
286 const char *args[6];
288 args[i++] = "read-tree";
289 if (verbose)
290 args[i++] = "-v";
291 args[i++] = "--reset";
292 args[i++] = "-u";
293 args[i++] = sha1_to_hex(sha1);
294 args[i] = NULL;
296 if (run_command_v_opt(args, RUN_GIT_CMD))
297 die(_("read-tree failed"));
300 static void restore_state(const unsigned char *head,
301 const unsigned char *stash)
303 struct strbuf sb = STRBUF_INIT;
304 const char *args[] = { "stash", "apply", NULL, NULL };
306 if (is_null_sha1(stash))
307 return;
309 reset_hard(head, 1);
311 args[2] = sha1_to_hex(stash);
314 * It is OK to ignore error here, for example when there was
315 * nothing to restore.
317 run_command_v_opt(args, RUN_GIT_CMD);
319 strbuf_release(&sb);
320 refresh_cache(REFRESH_QUIET);
323 /* This is called when no merge was necessary. */
324 static void finish_up_to_date(const char *msg)
326 if (verbosity >= 0)
327 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
328 drop_save();
331 static void squash_message(struct commit *commit, struct commit_list *remoteheads)
333 struct rev_info rev;
334 struct strbuf out = STRBUF_INIT;
335 struct commit_list *j;
336 const char *filename;
337 int fd;
338 struct pretty_print_context ctx = {0};
340 printf(_("Squash commit -- not updating HEAD\n"));
341 filename = git_path("SQUASH_MSG");
342 fd = open(filename, O_WRONLY | O_CREAT, 0666);
343 if (fd < 0)
344 die_errno(_("Could not write to '%s'"), filename);
346 init_revisions(&rev, NULL);
347 rev.ignore_merges = 1;
348 rev.commit_format = CMIT_FMT_MEDIUM;
350 commit->object.flags |= UNINTERESTING;
351 add_pending_object(&rev, &commit->object, NULL);
353 for (j = remoteheads; j; j = j->next)
354 add_pending_object(&rev, &j->item->object, NULL);
356 setup_revisions(0, NULL, &rev, NULL);
357 if (prepare_revision_walk(&rev))
358 die(_("revision walk setup failed"));
360 ctx.abbrev = rev.abbrev;
361 ctx.date_mode = rev.date_mode;
362 ctx.fmt = rev.commit_format;
364 strbuf_addstr(&out, "Squashed commit of the following:\n");
365 while ((commit = get_revision(&rev)) != NULL) {
366 strbuf_addch(&out, '\n');
367 strbuf_addf(&out, "commit %s\n",
368 sha1_to_hex(commit->object.sha1));
369 pretty_print_commit(&ctx, commit, &out);
371 if (write_in_full(fd, out.buf, out.len) != out.len)
372 die_errno(_("Writing SQUASH_MSG"));
373 if (close(fd))
374 die_errno(_("Finishing SQUASH_MSG"));
375 strbuf_release(&out);
378 static void finish(struct commit *head_commit,
379 struct commit_list *remoteheads,
380 const unsigned char *new_head, const char *msg)
382 struct strbuf reflog_message = STRBUF_INIT;
383 const unsigned char *head = head_commit->object.sha1;
385 if (!msg)
386 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
387 else {
388 if (verbosity >= 0)
389 printf("%s\n", msg);
390 strbuf_addf(&reflog_message, "%s: %s",
391 getenv("GIT_REFLOG_ACTION"), msg);
393 if (squash) {
394 squash_message(head_commit, remoteheads);
395 } else {
396 if (verbosity >= 0 && !merge_msg.len)
397 printf(_("No merge message -- not updating HEAD\n"));
398 else {
399 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
400 update_ref(reflog_message.buf, "HEAD",
401 new_head, head, 0,
402 UPDATE_REFS_DIE_ON_ERR);
404 * We ignore errors in 'gc --auto', since the
405 * user should see them.
407 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
410 if (new_head && show_diffstat) {
411 struct diff_options opts;
412 diff_setup(&opts);
413 opts.stat_width = -1; /* use full terminal width */
414 opts.stat_graph_width = -1; /* respect statGraphWidth config */
415 opts.output_format |=
416 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
417 opts.detect_rename = DIFF_DETECT_RENAME;
418 diff_setup_done(&opts);
419 diff_tree_sha1(head, new_head, "", &opts);
420 diffcore_std(&opts);
421 diff_flush(&opts);
424 /* Run a post-merge hook */
425 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
427 strbuf_release(&reflog_message);
430 /* Get the name for the merge commit's message. */
431 static void merge_name(const char *remote, struct strbuf *msg)
433 struct commit *remote_head;
434 unsigned char branch_head[20];
435 struct strbuf buf = STRBUF_INIT;
436 struct strbuf bname = STRBUF_INIT;
437 const char *ptr;
438 char *found_ref;
439 int len, early;
441 strbuf_branchname(&bname, remote);
442 remote = bname.buf;
444 memset(branch_head, 0, sizeof(branch_head));
445 remote_head = get_merge_parent(remote);
446 if (!remote_head)
447 die(_("'%s' does not point to a commit"), remote);
449 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
450 if (starts_with(found_ref, "refs/heads/")) {
451 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
452 sha1_to_hex(branch_head), remote);
453 goto cleanup;
455 if (starts_with(found_ref, "refs/tags/")) {
456 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
457 sha1_to_hex(branch_head), remote);
458 goto cleanup;
460 if (starts_with(found_ref, "refs/remotes/")) {
461 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
462 sha1_to_hex(branch_head), remote);
463 goto cleanup;
467 /* See if remote matches <name>^^^.. or <name>~<number> */
468 for (len = 0, ptr = remote + strlen(remote);
469 remote < ptr && ptr[-1] == '^';
470 ptr--)
471 len++;
472 if (len)
473 early = 1;
474 else {
475 early = 0;
476 ptr = strrchr(remote, '~');
477 if (ptr) {
478 int seen_nonzero = 0;
480 len++; /* count ~ */
481 while (*++ptr && isdigit(*ptr)) {
482 seen_nonzero |= (*ptr != '0');
483 len++;
485 if (*ptr)
486 len = 0; /* not ...~<number> */
487 else if (seen_nonzero)
488 early = 1;
489 else if (len == 1)
490 early = 1; /* "name~" is "name~1"! */
493 if (len) {
494 struct strbuf truname = STRBUF_INIT;
495 strbuf_addstr(&truname, "refs/heads/");
496 strbuf_addstr(&truname, remote);
497 strbuf_setlen(&truname, truname.len - len);
498 if (ref_exists(truname.buf)) {
499 strbuf_addf(msg,
500 "%s\t\tbranch '%s'%s of .\n",
501 sha1_to_hex(remote_head->object.sha1),
502 truname.buf + 11,
503 (early ? " (early part)" : ""));
504 strbuf_release(&truname);
505 goto cleanup;
509 if (!strcmp(remote, "FETCH_HEAD") &&
510 !access(git_path("FETCH_HEAD"), R_OK)) {
511 const char *filename;
512 FILE *fp;
513 struct strbuf line = STRBUF_INIT;
514 char *ptr;
516 filename = git_path("FETCH_HEAD");
517 fp = fopen(filename, "r");
518 if (!fp)
519 die_errno(_("could not open '%s' for reading"),
520 filename);
521 strbuf_getline(&line, fp, '\n');
522 fclose(fp);
523 ptr = strstr(line.buf, "\tnot-for-merge\t");
524 if (ptr)
525 strbuf_remove(&line, ptr-line.buf+1, 13);
526 strbuf_addbuf(msg, &line);
527 strbuf_release(&line);
528 goto cleanup;
531 if (remote_head->util) {
532 struct merge_remote_desc *desc;
533 desc = merge_remote_util(remote_head);
534 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
535 strbuf_addf(msg, "%s\t\t%s '%s'\n",
536 sha1_to_hex(desc->obj->sha1),
537 typename(desc->obj->type),
538 remote);
539 goto cleanup;
543 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
544 sha1_to_hex(remote_head->object.sha1), remote);
545 cleanup:
546 strbuf_release(&buf);
547 strbuf_release(&bname);
550 static void parse_branch_merge_options(char *bmo)
552 const char **argv;
553 int argc;
555 if (!bmo)
556 return;
557 argc = split_cmdline(bmo, &argv);
558 if (argc < 0)
559 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
560 split_cmdline_strerror(argc));
561 REALLOC_ARRAY(argv, argc + 2);
562 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
563 argc++;
564 argv[0] = "branch.*.mergeoptions";
565 parse_options(argc, argv, NULL, builtin_merge_options,
566 builtin_merge_usage, 0);
567 free(argv);
570 static int git_merge_config(const char *k, const char *v, void *cb)
572 int status;
574 if (branch && starts_with(k, "branch.") &&
575 starts_with(k + 7, branch) &&
576 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
577 free(branch_mergeoptions);
578 branch_mergeoptions = xstrdup(v);
579 return 0;
582 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
583 show_diffstat = git_config_bool(k, v);
584 else if (!strcmp(k, "pull.twohead"))
585 return git_config_string(&pull_twohead, k, v);
586 else if (!strcmp(k, "pull.octopus"))
587 return git_config_string(&pull_octopus, k, v);
588 else if (!strcmp(k, "merge.renormalize"))
589 option_renormalize = git_config_bool(k, v);
590 else if (!strcmp(k, "merge.ff")) {
591 int boolval = git_config_maybe_bool(k, v);
592 if (0 <= boolval) {
593 fast_forward = boolval ? FF_ALLOW : FF_NO;
594 } else if (v && !strcmp(v, "only")) {
595 fast_forward = FF_ONLY;
596 } /* do not barf on values from future versions of git */
597 return 0;
598 } else if (!strcmp(k, "merge.defaulttoupstream")) {
599 default_to_upstream = git_config_bool(k, v);
600 return 0;
601 } else if (!strcmp(k, "commit.gpgsign")) {
602 sign_commit = git_config_bool(k, v) ? "" : NULL;
603 return 0;
606 status = fmt_merge_msg_config(k, v, cb);
607 if (status)
608 return status;
609 status = git_gpg_config(k, v, NULL);
610 if (status)
611 return status;
612 return git_diff_ui_config(k, v, cb);
615 static int read_tree_trivial(unsigned char *common, unsigned char *head,
616 unsigned char *one)
618 int i, nr_trees = 0;
619 struct tree *trees[MAX_UNPACK_TREES];
620 struct tree_desc t[MAX_UNPACK_TREES];
621 struct unpack_trees_options opts;
623 memset(&opts, 0, sizeof(opts));
624 opts.head_idx = 2;
625 opts.src_index = &the_index;
626 opts.dst_index = &the_index;
627 opts.update = 1;
628 opts.verbose_update = 1;
629 opts.trivial_merges_only = 1;
630 opts.merge = 1;
631 trees[nr_trees] = parse_tree_indirect(common);
632 if (!trees[nr_trees++])
633 return -1;
634 trees[nr_trees] = parse_tree_indirect(head);
635 if (!trees[nr_trees++])
636 return -1;
637 trees[nr_trees] = parse_tree_indirect(one);
638 if (!trees[nr_trees++])
639 return -1;
640 opts.fn = threeway_merge;
641 cache_tree_free(&active_cache_tree);
642 for (i = 0; i < nr_trees; i++) {
643 parse_tree(trees[i]);
644 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
646 if (unpack_trees(nr_trees, t, &opts))
647 return -1;
648 return 0;
651 static void write_tree_trivial(unsigned char *sha1)
653 if (write_cache_as_tree(sha1, 0, NULL))
654 die(_("git write-tree failed to write a tree"));
657 static int try_merge_strategy(const char *strategy, struct commit_list *common,
658 struct commit_list *remoteheads,
659 struct commit *head, const char *head_arg)
661 static struct lock_file lock;
663 hold_locked_index(&lock, 1);
664 refresh_cache(REFRESH_QUIET);
665 if (active_cache_changed &&
666 write_locked_index(&the_index, &lock, COMMIT_LOCK))
667 return error(_("Unable to write index."));
668 rollback_lock_file(&lock);
670 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
671 int clean, x;
672 struct commit *result;
673 struct commit_list *reversed = NULL;
674 struct merge_options o;
675 struct commit_list *j;
677 if (remoteheads->next) {
678 error(_("Not handling anything other than two heads merge."));
679 return 2;
682 init_merge_options(&o);
683 if (!strcmp(strategy, "subtree"))
684 o.subtree_shift = "";
686 o.renormalize = option_renormalize;
687 o.show_rename_progress =
688 show_progress == -1 ? isatty(2) : show_progress;
690 for (x = 0; x < xopts_nr; x++)
691 if (parse_merge_opt(&o, xopts[x]))
692 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
694 o.branch1 = head_arg;
695 o.branch2 = merge_remote_util(remoteheads->item)->name;
697 for (j = common; j; j = j->next)
698 commit_list_insert(j->item, &reversed);
700 hold_locked_index(&lock, 1);
701 clean = merge_recursive(&o, head,
702 remoteheads->item, reversed, &result);
703 if (active_cache_changed &&
704 write_locked_index(&the_index, &lock, COMMIT_LOCK))
705 die (_("unable to write %s"), get_index_file());
706 rollback_lock_file(&lock);
707 return clean ? 0 : 1;
708 } else {
709 return try_merge_command(strategy, xopts_nr, xopts,
710 common, head_arg, remoteheads);
714 static void count_diff_files(struct diff_queue_struct *q,
715 struct diff_options *opt, void *data)
717 int *count = data;
719 (*count) += q->nr;
722 static int count_unmerged_entries(void)
724 int i, ret = 0;
726 for (i = 0; i < active_nr; i++)
727 if (ce_stage(active_cache[i]))
728 ret++;
730 return ret;
733 static void split_merge_strategies(const char *string, struct strategy **list,
734 int *nr, int *alloc)
736 char *p, *q, *buf;
738 if (!string)
739 return;
741 buf = xstrdup(string);
742 q = buf;
743 for (;;) {
744 p = strchr(q, ' ');
745 if (!p) {
746 ALLOC_GROW(*list, *nr + 1, *alloc);
747 (*list)[(*nr)++].name = xstrdup(q);
748 free(buf);
749 return;
750 } else {
751 *p = '\0';
752 ALLOC_GROW(*list, *nr + 1, *alloc);
753 (*list)[(*nr)++].name = xstrdup(q);
754 q = ++p;
759 static void add_strategies(const char *string, unsigned attr)
761 struct strategy *list = NULL;
762 int list_alloc = 0, list_nr = 0, i;
764 memset(&list, 0, sizeof(list));
765 split_merge_strategies(string, &list, &list_nr, &list_alloc);
766 if (list) {
767 for (i = 0; i < list_nr; i++)
768 append_strategy(get_strategy(list[i].name));
769 return;
771 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
772 if (all_strategy[i].attr & attr)
773 append_strategy(&all_strategy[i]);
777 static void write_merge_msg(struct strbuf *msg)
779 const char *filename = git_path("MERGE_MSG");
780 int fd = open(filename, O_WRONLY | O_CREAT, 0666);
781 if (fd < 0)
782 die_errno(_("Could not open '%s' for writing"),
783 filename);
784 if (write_in_full(fd, msg->buf, msg->len) != msg->len)
785 die_errno(_("Could not write to '%s'"), filename);
786 close(fd);
789 static void read_merge_msg(struct strbuf *msg)
791 const char *filename = git_path("MERGE_MSG");
792 strbuf_reset(msg);
793 if (strbuf_read_file(msg, filename, 0) < 0)
794 die_errno(_("Could not read from '%s'"), filename);
797 static void write_merge_state(struct commit_list *);
798 static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
800 if (err_msg)
801 error("%s", err_msg);
802 fprintf(stderr,
803 _("Not committing merge; use 'git commit' to complete the merge.\n"));
804 write_merge_state(remoteheads);
805 exit(1);
808 static const char merge_editor_comment[] =
809 N_("Please enter a commit message to explain why this merge is necessary,\n"
810 "especially if it merges an updated upstream into a topic branch.\n"
811 "\n"
812 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
813 "the commit.\n");
815 static void prepare_to_commit(struct commit_list *remoteheads)
817 struct strbuf msg = STRBUF_INIT;
818 strbuf_addbuf(&msg, &merge_msg);
819 strbuf_addch(&msg, '\n');
820 if (0 < option_edit)
821 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
822 write_merge_msg(&msg);
823 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
824 git_path("MERGE_MSG"), "merge", NULL))
825 abort_commit(remoteheads, NULL);
826 if (0 < option_edit) {
827 if (launch_editor(git_path("MERGE_MSG"), NULL, NULL))
828 abort_commit(remoteheads, NULL);
830 read_merge_msg(&msg);
831 stripspace(&msg, 0 < option_edit);
832 if (!msg.len)
833 abort_commit(remoteheads, _("Empty commit message."));
834 strbuf_release(&merge_msg);
835 strbuf_addbuf(&merge_msg, &msg);
836 strbuf_release(&msg);
839 static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
841 unsigned char result_tree[20], result_commit[20];
842 struct commit_list *parents, **pptr = &parents;
844 write_tree_trivial(result_tree);
845 printf(_("Wonderful.\n"));
846 pptr = commit_list_append(head, pptr);
847 pptr = commit_list_append(remoteheads->item, pptr);
848 prepare_to_commit(remoteheads);
849 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
850 result_commit, NULL, sign_commit))
851 die(_("failed to write commit object"));
852 finish(head, remoteheads, result_commit, "In-index merge");
853 drop_save();
854 return 0;
857 static int finish_automerge(struct commit *head,
858 int head_subsumed,
859 struct commit_list *common,
860 struct commit_list *remoteheads,
861 unsigned char *result_tree,
862 const char *wt_strategy)
864 struct commit_list *parents = NULL;
865 struct strbuf buf = STRBUF_INIT;
866 unsigned char result_commit[20];
868 free_commit_list(common);
869 parents = remoteheads;
870 if (!head_subsumed || fast_forward == FF_NO)
871 commit_list_insert(head, &parents);
872 strbuf_addch(&merge_msg, '\n');
873 prepare_to_commit(remoteheads);
874 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
875 result_commit, NULL, sign_commit))
876 die(_("failed to write commit object"));
877 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
878 finish(head, remoteheads, result_commit, buf.buf);
879 strbuf_release(&buf);
880 drop_save();
881 return 0;
884 static int suggest_conflicts(void)
886 const char *filename;
887 FILE *fp;
888 struct strbuf msgbuf = STRBUF_INIT;
890 filename = git_path("MERGE_MSG");
891 fp = fopen(filename, "a");
892 if (!fp)
893 die_errno(_("Could not open '%s' for writing"), filename);
895 append_conflicts_hint(&msgbuf);
896 fputs(msgbuf.buf, fp);
897 strbuf_release(&msgbuf);
898 fclose(fp);
899 rerere(allow_rerere_auto);
900 printf(_("Automatic merge failed; "
901 "fix conflicts and then commit the result.\n"));
902 return 1;
905 static struct commit *is_old_style_invocation(int argc, const char **argv,
906 const unsigned char *head)
908 struct commit *second_token = NULL;
909 if (argc > 2) {
910 unsigned char second_sha1[20];
912 if (get_sha1(argv[1], second_sha1))
913 return NULL;
914 second_token = lookup_commit_reference_gently(second_sha1, 0);
915 if (!second_token)
916 die(_("'%s' is not a commit"), argv[1]);
917 if (hashcmp(second_token->object.sha1, head))
918 return NULL;
920 return second_token;
923 static int evaluate_result(void)
925 int cnt = 0;
926 struct rev_info rev;
928 /* Check how many files differ. */
929 init_revisions(&rev, "");
930 setup_revisions(0, NULL, &rev, NULL);
931 rev.diffopt.output_format |=
932 DIFF_FORMAT_CALLBACK;
933 rev.diffopt.format_callback = count_diff_files;
934 rev.diffopt.format_callback_data = &cnt;
935 run_diff_files(&rev, 0);
938 * Check how many unmerged entries are
939 * there.
941 cnt += count_unmerged_entries();
943 return cnt;
947 * Pretend as if the user told us to merge with the remote-tracking
948 * branch we have for the upstream of the current branch
950 static int setup_with_upstream(const char ***argv)
952 struct branch *branch = branch_get(NULL);
953 int i;
954 const char **args;
956 if (!branch)
957 die(_("No current branch."));
958 if (!branch->remote)
959 die(_("No remote for the current branch."));
960 if (!branch->merge_nr)
961 die(_("No default upstream defined for the current branch."));
963 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
964 for (i = 0; i < branch->merge_nr; i++) {
965 if (!branch->merge[i]->dst)
966 die(_("No remote-tracking branch for %s from %s"),
967 branch->merge[i]->src, branch->remote_name);
968 args[i] = branch->merge[i]->dst;
970 args[i] = NULL;
971 *argv = args;
972 return i;
975 static void write_merge_state(struct commit_list *remoteheads)
977 const char *filename;
978 int fd;
979 struct commit_list *j;
980 struct strbuf buf = STRBUF_INIT;
982 for (j = remoteheads; j; j = j->next) {
983 unsigned const char *sha1;
984 struct commit *c = j->item;
985 if (c->util && merge_remote_util(c)->obj) {
986 sha1 = merge_remote_util(c)->obj->sha1;
987 } else {
988 sha1 = c->object.sha1;
990 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
992 filename = git_path("MERGE_HEAD");
993 fd = open(filename, O_WRONLY | O_CREAT, 0666);
994 if (fd < 0)
995 die_errno(_("Could not open '%s' for writing"), filename);
996 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
997 die_errno(_("Could not write to '%s'"), filename);
998 close(fd);
999 strbuf_addch(&merge_msg, '\n');
1000 write_merge_msg(&merge_msg);
1002 filename = git_path("MERGE_MODE");
1003 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
1004 if (fd < 0)
1005 die_errno(_("Could not open '%s' for writing"), filename);
1006 strbuf_reset(&buf);
1007 if (fast_forward == FF_NO)
1008 strbuf_addf(&buf, "no-ff");
1009 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1010 die_errno(_("Could not write to '%s'"), filename);
1011 close(fd);
1014 static int default_edit_option(void)
1016 static const char name[] = "GIT_MERGE_AUTOEDIT";
1017 const char *e = getenv(name);
1018 struct stat st_stdin, st_stdout;
1020 if (have_message)
1021 /* an explicit -m msg without --[no-]edit */
1022 return 0;
1024 if (e) {
1025 int v = git_config_maybe_bool(name, e);
1026 if (v < 0)
1027 die("Bad value '%s' in environment '%s'", e, name);
1028 return v;
1031 /* Use editor if stdin and stdout are the same and is a tty */
1032 return (!fstat(0, &st_stdin) &&
1033 !fstat(1, &st_stdout) &&
1034 isatty(0) && isatty(1) &&
1035 st_stdin.st_dev == st_stdout.st_dev &&
1036 st_stdin.st_ino == st_stdout.st_ino &&
1037 st_stdin.st_mode == st_stdout.st_mode);
1040 static struct commit_list *collect_parents(struct commit *head_commit,
1041 int *head_subsumed,
1042 int argc, const char **argv)
1044 int i;
1045 struct commit_list *remoteheads = NULL, *parents, *next;
1046 struct commit_list **remotes = &remoteheads;
1048 if (head_commit)
1049 remotes = &commit_list_insert(head_commit, remotes)->next;
1050 for (i = 0; i < argc; i++) {
1051 struct commit *commit = get_merge_parent(argv[i]);
1052 if (!commit)
1053 help_unknown_ref(argv[i], "merge",
1054 "not something we can merge");
1055 remotes = &commit_list_insert(commit, remotes)->next;
1057 *remotes = NULL;
1059 parents = reduce_heads(remoteheads);
1061 *head_subsumed = 1; /* we will flip this to 0 when we find it */
1062 for (remoteheads = NULL, remotes = &remoteheads;
1063 parents;
1064 parents = next) {
1065 struct commit *commit = parents->item;
1066 next = parents->next;
1067 if (commit == head_commit)
1068 *head_subsumed = 0;
1069 else
1070 remotes = &commit_list_insert(commit, remotes)->next;
1072 return remoteheads;
1075 int cmd_merge(int argc, const char **argv, const char *prefix)
1077 unsigned char result_tree[20];
1078 unsigned char stash[20];
1079 unsigned char head_sha1[20];
1080 struct commit *head_commit;
1081 struct strbuf buf = STRBUF_INIT;
1082 const char *head_arg;
1083 int flag, i, ret = 0, head_subsumed;
1084 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1085 struct commit_list *common = NULL;
1086 const char *best_strategy = NULL, *wt_strategy = NULL;
1087 struct commit_list *remoteheads, *p;
1088 void *branch_to_free;
1090 if (argc == 2 && !strcmp(argv[1], "-h"))
1091 usage_with_options(builtin_merge_usage, builtin_merge_options);
1094 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1095 * current branch.
1097 branch = branch_to_free = resolve_refdup("HEAD", 0, head_sha1, &flag);
1098 if (branch && starts_with(branch, "refs/heads/"))
1099 branch += 11;
1100 if (!branch || is_null_sha1(head_sha1))
1101 head_commit = NULL;
1102 else
1103 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1105 git_config(git_merge_config, NULL);
1107 if (branch_mergeoptions)
1108 parse_branch_merge_options(branch_mergeoptions);
1109 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1110 builtin_merge_usage, 0);
1111 if (shortlog_len < 0)
1112 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1114 if (verbosity < 0 && show_progress == -1)
1115 show_progress = 0;
1117 if (abort_current_merge) {
1118 int nargc = 2;
1119 const char *nargv[] = {"reset", "--merge", NULL};
1121 if (!file_exists(git_path("MERGE_HEAD")))
1122 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1124 /* Invoke 'git reset --merge' */
1125 ret = cmd_reset(nargc, nargv, prefix);
1126 goto done;
1129 if (read_cache_unmerged())
1130 die_resolve_conflict("merge");
1132 if (file_exists(git_path("MERGE_HEAD"))) {
1134 * There is no unmerged entry, don't advise 'git
1135 * add/rm <file>', just 'git commit'.
1137 if (advice_resolve_conflict)
1138 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1139 "Please, commit your changes before you merge."));
1140 else
1141 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1143 if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
1144 if (advice_resolve_conflict)
1145 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1146 "Please, commit your changes before you merge."));
1147 else
1148 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1150 resolve_undo_clear();
1152 if (verbosity < 0)
1153 show_diffstat = 0;
1155 if (squash) {
1156 if (fast_forward == FF_NO)
1157 die(_("You cannot combine --squash with --no-ff."));
1158 option_commit = 0;
1161 if (!abort_current_merge) {
1162 if (!argc) {
1163 if (default_to_upstream)
1164 argc = setup_with_upstream(&argv);
1165 else
1166 die(_("No commit specified and merge.defaultToUpstream not set."));
1167 } else if (argc == 1 && !strcmp(argv[0], "-"))
1168 argv[0] = "@{-1}";
1170 if (!argc)
1171 usage_with_options(builtin_merge_usage,
1172 builtin_merge_options);
1175 * This could be traditional "merge <msg> HEAD <commit>..." and
1176 * the way we can tell it is to see if the second token is HEAD,
1177 * but some people might have misused the interface and used a
1178 * commit-ish that is the same as HEAD there instead.
1179 * Traditional format never would have "-m" so it is an
1180 * additional safety measure to check for it.
1183 if (!have_message && head_commit &&
1184 is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
1185 strbuf_addstr(&merge_msg, argv[0]);
1186 head_arg = argv[1];
1187 argv += 2;
1188 argc -= 2;
1189 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1190 } else if (!head_commit) {
1191 struct commit *remote_head;
1193 * If the merged head is a valid one there is no reason
1194 * to forbid "git merge" into a branch yet to be born.
1195 * We do the same for "git pull".
1197 if (argc != 1)
1198 die(_("Can merge only exactly one commit into "
1199 "empty head"));
1200 if (squash)
1201 die(_("Squash commit into empty head not supported yet"));
1202 if (fast_forward == FF_NO)
1203 die(_("Non-fast-forward commit does not make sense into "
1204 "an empty head"));
1205 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1206 remote_head = remoteheads->item;
1207 if (!remote_head)
1208 die(_("%s - not something we can merge"), argv[0]);
1209 read_empty(remote_head->object.sha1, 0);
1210 update_ref("initial pull", "HEAD", remote_head->object.sha1,
1211 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1212 goto done;
1213 } else {
1214 struct strbuf merge_names = STRBUF_INIT;
1216 /* We are invoked directly as the first-class UI. */
1217 head_arg = "HEAD";
1220 * All the rest are the commits being merged; prepare
1221 * the standard merge summary message to be appended
1222 * to the given message.
1224 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1225 for (p = remoteheads; p; p = p->next)
1226 merge_name(merge_remote_util(p->item)->name, &merge_names);
1228 if (!have_message || shortlog_len) {
1229 struct fmt_merge_msg_opts opts;
1230 memset(&opts, 0, sizeof(opts));
1231 opts.add_title = !have_message;
1232 opts.shortlog_len = shortlog_len;
1233 opts.credit_people = (0 < option_edit);
1235 fmt_merge_msg(&merge_names, &merge_msg, &opts);
1236 if (merge_msg.len)
1237 strbuf_setlen(&merge_msg, merge_msg.len - 1);
1241 if (!head_commit || !argc)
1242 usage_with_options(builtin_merge_usage,
1243 builtin_merge_options);
1245 if (verify_signatures) {
1246 for (p = remoteheads; p; p = p->next) {
1247 struct commit *commit = p->item;
1248 char hex[41];
1249 struct signature_check signature_check;
1250 memset(&signature_check, 0, sizeof(signature_check));
1252 check_commit_signature(commit, &signature_check);
1254 strcpy(hex, find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
1255 switch (signature_check.result) {
1256 case 'G':
1257 break;
1258 case 'U':
1259 die(_("Commit %s has an untrusted GPG signature, "
1260 "allegedly by %s."), hex, signature_check.signer);
1261 case 'B':
1262 die(_("Commit %s has a bad GPG signature "
1263 "allegedly by %s."), hex, signature_check.signer);
1264 default: /* 'N' */
1265 die(_("Commit %s does not have a GPG signature."), hex);
1267 if (verbosity >= 0 && signature_check.result == 'G')
1268 printf(_("Commit %s has a good GPG signature by %s\n"),
1269 hex, signature_check.signer);
1271 signature_check_clear(&signature_check);
1275 strbuf_addstr(&buf, "merge");
1276 for (p = remoteheads; p; p = p->next)
1277 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1278 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1279 strbuf_reset(&buf);
1281 for (p = remoteheads; p; p = p->next) {
1282 struct commit *commit = p->item;
1283 strbuf_addf(&buf, "GITHEAD_%s",
1284 sha1_to_hex(commit->object.sha1));
1285 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1286 strbuf_reset(&buf);
1287 if (fast_forward != FF_ONLY &&
1288 merge_remote_util(commit) &&
1289 merge_remote_util(commit)->obj &&
1290 merge_remote_util(commit)->obj->type == OBJ_TAG)
1291 fast_forward = FF_NO;
1294 if (option_edit < 0)
1295 option_edit = default_edit_option();
1297 if (!use_strategies) {
1298 if (!remoteheads)
1299 ; /* already up-to-date */
1300 else if (!remoteheads->next)
1301 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1302 else
1303 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1306 for (i = 0; i < use_strategies_nr; i++) {
1307 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1308 fast_forward = FF_NO;
1309 if (use_strategies[i]->attr & NO_TRIVIAL)
1310 allow_trivial = 0;
1313 if (!remoteheads)
1314 ; /* already up-to-date */
1315 else if (!remoteheads->next)
1316 common = get_merge_bases(head_commit, remoteheads->item);
1317 else {
1318 struct commit_list *list = remoteheads;
1319 commit_list_insert(head_commit, &list);
1320 common = get_octopus_merge_bases(list);
1321 free(list);
1324 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
1325 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1327 if (remoteheads && !common)
1328 ; /* No common ancestors found. We need a real merge. */
1329 else if (!remoteheads ||
1330 (!remoteheads->next && !common->next &&
1331 common->item == remoteheads->item)) {
1333 * If head can reach all the merge then we are up to date.
1334 * but first the most common case of merging one remote.
1336 finish_up_to_date("Already up-to-date.");
1337 goto done;
1338 } else if (fast_forward != FF_NO && !remoteheads->next &&
1339 !common->next &&
1340 !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
1341 /* Again the most common case of merging one remote. */
1342 struct strbuf msg = STRBUF_INIT;
1343 struct commit *commit;
1344 char hex[41];
1346 strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
1348 if (verbosity >= 0)
1349 printf(_("Updating %s..%s\n"),
1350 hex,
1351 find_unique_abbrev(remoteheads->item->object.sha1,
1352 DEFAULT_ABBREV));
1353 strbuf_addstr(&msg, "Fast-forward");
1354 if (have_message)
1355 strbuf_addstr(&msg,
1356 " (no commit created; -m option ignored)");
1357 commit = remoteheads->item;
1358 if (!commit) {
1359 ret = 1;
1360 goto done;
1363 if (checkout_fast_forward(head_commit->object.sha1,
1364 commit->object.sha1,
1365 overwrite_ignore)) {
1366 ret = 1;
1367 goto done;
1370 finish(head_commit, remoteheads, commit->object.sha1, msg.buf);
1371 drop_save();
1372 goto done;
1373 } else if (!remoteheads->next && common->next)
1376 * We are not doing octopus and not fast-forward. Need
1377 * a real merge.
1379 else if (!remoteheads->next && !common->next && option_commit) {
1381 * We are not doing octopus, not fast-forward, and have
1382 * only one common.
1384 refresh_cache(REFRESH_QUIET);
1385 if (allow_trivial && fast_forward != FF_ONLY) {
1386 /* See if it is really trivial. */
1387 git_committer_info(IDENT_STRICT);
1388 printf(_("Trying really trivial in-index merge...\n"));
1389 if (!read_tree_trivial(common->item->object.sha1,
1390 head_commit->object.sha1,
1391 remoteheads->item->object.sha1)) {
1392 ret = merge_trivial(head_commit, remoteheads);
1393 goto done;
1395 printf(_("Nope.\n"));
1397 } else {
1399 * An octopus. If we can reach all the remote we are up
1400 * to date.
1402 int up_to_date = 1;
1403 struct commit_list *j;
1405 for (j = remoteheads; j; j = j->next) {
1406 struct commit_list *common_one;
1409 * Here we *have* to calculate the individual
1410 * merge_bases again, otherwise "git merge HEAD^
1411 * HEAD^^" would be missed.
1413 common_one = get_merge_bases(head_commit, j->item);
1414 if (hashcmp(common_one->item->object.sha1,
1415 j->item->object.sha1)) {
1416 up_to_date = 0;
1417 break;
1420 if (up_to_date) {
1421 finish_up_to_date("Already up-to-date. Yeeah!");
1422 goto done;
1426 if (fast_forward == FF_ONLY)
1427 die(_("Not possible to fast-forward, aborting."));
1429 /* We are going to make a new commit. */
1430 git_committer_info(IDENT_STRICT);
1433 * At this point, we need a real merge. No matter what strategy
1434 * we use, it would operate on the index, possibly affecting the
1435 * working tree, and when resolved cleanly, have the desired
1436 * tree in the index -- this means that the index must be in
1437 * sync with the head commit. The strategies are responsible
1438 * to ensure this.
1440 if (use_strategies_nr == 1 ||
1442 * Stash away the local changes so that we can try more than one.
1444 save_state(stash))
1445 hashcpy(stash, null_sha1);
1447 for (i = 0; i < use_strategies_nr; i++) {
1448 int ret;
1449 if (i) {
1450 printf(_("Rewinding the tree to pristine...\n"));
1451 restore_state(head_commit->object.sha1, stash);
1453 if (use_strategies_nr != 1)
1454 printf(_("Trying merge strategy %s...\n"),
1455 use_strategies[i]->name);
1457 * Remember which strategy left the state in the working
1458 * tree.
1460 wt_strategy = use_strategies[i]->name;
1462 ret = try_merge_strategy(use_strategies[i]->name,
1463 common, remoteheads,
1464 head_commit, head_arg);
1465 if (!option_commit && !ret) {
1466 merge_was_ok = 1;
1468 * This is necessary here just to avoid writing
1469 * the tree, but later we will *not* exit with
1470 * status code 1 because merge_was_ok is set.
1472 ret = 1;
1475 if (ret) {
1477 * The backend exits with 1 when conflicts are
1478 * left to be resolved, with 2 when it does not
1479 * handle the given merge at all.
1481 if (ret == 1) {
1482 int cnt = evaluate_result();
1484 if (best_cnt <= 0 || cnt <= best_cnt) {
1485 best_strategy = use_strategies[i]->name;
1486 best_cnt = cnt;
1489 if (merge_was_ok)
1490 break;
1491 else
1492 continue;
1495 /* Automerge succeeded. */
1496 write_tree_trivial(result_tree);
1497 automerge_was_ok = 1;
1498 break;
1502 * If we have a resulting tree, that means the strategy module
1503 * auto resolved the merge cleanly.
1505 if (automerge_was_ok) {
1506 ret = finish_automerge(head_commit, head_subsumed,
1507 common, remoteheads,
1508 result_tree, wt_strategy);
1509 goto done;
1513 * Pick the result from the best strategy and have the user fix
1514 * it up.
1516 if (!best_strategy) {
1517 restore_state(head_commit->object.sha1, stash);
1518 if (use_strategies_nr > 1)
1519 fprintf(stderr,
1520 _("No merge strategy handled the merge.\n"));
1521 else
1522 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1523 use_strategies[0]->name);
1524 ret = 2;
1525 goto done;
1526 } else if (best_strategy == wt_strategy)
1527 ; /* We already have its result in the working tree. */
1528 else {
1529 printf(_("Rewinding the tree to pristine...\n"));
1530 restore_state(head_commit->object.sha1, stash);
1531 printf(_("Using the %s to prepare resolving by hand.\n"),
1532 best_strategy);
1533 try_merge_strategy(best_strategy, common, remoteheads,
1534 head_commit, head_arg);
1537 if (squash)
1538 finish(head_commit, remoteheads, NULL, NULL);
1539 else
1540 write_merge_state(remoteheads);
1542 if (merge_was_ok)
1543 fprintf(stderr, _("Automatic merge went well; "
1544 "stopped before committing as requested\n"));
1545 else
1546 ret = suggest_conflicts();
1548 done:
1549 free(branch_to_free);
1550 return ret;