1/*
2 * Builtin "git merge"
3 *
4 * Copyright (c) 2008 Miklos Vajna <vmiklos@frugalware.org>
5 *
6 * Based on git-merge.sh by Junio C Hamano.
7 */
8#include "cache.h"
10#include "config.h"
11#include "parse-options.h"
12#include "builtin.h"
13#include "lockfile.h"
14#include "run-command.h"
15#include "diff.h"
16#include "refs.h"
17#include "refspec.h"
18#include "commit.h"
19#include "diffcore.h"
20#include "revision.h"
21#include "unpack-trees.h"
22#include "cache-tree.h"
23#include "dir.h"
24#include "utf8.h"
25#include "log-tree.h"
26#include "color.h"
27#include "rerere.h"
28#include "help.h"
29#include "merge-recursive.h"
30#include "resolve-undo.h"
31#include "remote.h"
32#include "fmt-merge-msg.h"
33#include "gpg-interface.h"
34#include "sequencer.h"
35#include "string-list.h"
36#include "packfile.h"
37#include "tag.h"
38#include "alias.h"
39#include "commit-reach.h"
40#define DEFAULT_TWOHEAD (1<<0)
42#define DEFAULT_OCTOPUS (1<<1)
43#define NO_FAST_FORWARD (1<<2)
44#define NO_TRIVIAL (1<<3)
45struct strategy {
47 const char *name;
48 unsigned attr;
49};
50static const char * const builtin_merge_usage[] = {
52 N_("git merge [<options>] [<commit>...]"),
53 N_("git merge --abort"),
54 N_("git merge --continue"),
55 NULL
56};
57static int show_diffstat = 1, shortlog_len = -1, squash;
59static int option_commit = 1;
60static int option_edit = -1;
61static int allow_trivial = 1, have_message, verify_signatures;
62static int overwrite_ignore = 1;
63static struct strbuf merge_msg = STRBUF_INIT;
64static struct strategy **use_strategies;
65static size_t use_strategies_nr, use_strategies_alloc;
66static const char **xopts;
67static size_t xopts_nr, xopts_alloc;
68static const char *branch;
69static char *branch_mergeoptions;
70static int option_renormalize;
71static int verbosity;
72static int allow_rerere_auto;
73static int abort_current_merge;
74static int continue_current_merge;
75static int allow_unrelated_histories;
76static int show_progress = -1;
77static int default_to_upstream = 1;
78static int signoff;
79static const char *sign_commit;
80static int verify_msg = 1;
81static struct strategy all_strategy[] = {
83 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
84 { "octopus", DEFAULT_OCTOPUS },
85 { "resolve", 0 },
86 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
87 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
88};
89static const char *pull_twohead, *pull_octopus;
91enum ff_type {
93 FF_NO,
94 FF_ALLOW,
95 FF_ONLY
96};
97static enum ff_type fast_forward = FF_ALLOW;
99static int option_parse_message(const struct option *opt,
101 const char *arg, int unset)
102{
103 struct strbuf *buf = opt->value;
104 if (unset)
106 strbuf_setlen(buf, 0);
107 else if (arg) {
108 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
109 have_message = 1;
110 } else
111 return error(_("switch `m' requires a value"));
112 return 0;
113}
114static int option_read_message(struct parse_opt_ctx_t *ctx,
116 const struct option *opt, int unset)
117{
118 struct strbuf *buf = opt->value;
119 const char *arg;
120 if (unset)
122 BUG("-F cannot be negated");
123 if (ctx->opt) {
125 arg = ctx->opt;
126 ctx->opt = NULL;
127 } else if (ctx->argc > 1) {
128 ctx->argc--;
129 arg = *++ctx->argv;
130 } else
131 return error(_("option `%s' requires a value"), opt->long_name);
132 if (buf->len)
134 strbuf_addch(buf, '\n');
135 if (ctx->prefix && !is_absolute_path(arg))
136 arg = prefix_filename(ctx->prefix, arg);
137 if (strbuf_read_file(buf, arg, 0) < 0)
138 return error(_("could not read file '%s'"), arg);
139 have_message = 1;
140 return 0;
142}
143static struct strategy *get_strategy(const char *name)
145{
146 int i;
147 struct strategy *ret;
148 static struct cmdnames main_cmds, other_cmds;
149 static int loaded;
150 if (!name)
152 return NULL;
153 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
155 if (!strcmp(name, all_strategy[i].name))
156 return &all_strategy[i];
157 if (!loaded) {
159 struct cmdnames not_strategies;
160 loaded = 1;
161 memset(¬_strategies, 0, sizeof(struct cmdnames));
163 load_command_list("git-merge-", &main_cmds, &other_cmds);
164 for (i = 0; i < main_cmds.cnt; i++) {
165 int j, found = 0;
166 struct cmdname *ent = main_cmds.names[i];
167 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
168 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
169 && !all_strategy[j].name[ent->len])
170 found = 1;
171 if (!found)
172 add_cmdname(¬_strategies, ent->name, ent->len);
173 }
174 exclude_cmds(&main_cmds, ¬_strategies);
175 }
176 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
177 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
178 fprintf(stderr, _("Available strategies are:"));
179 for (i = 0; i < main_cmds.cnt; i++)
180 fprintf(stderr, " %s", main_cmds.names[i]->name);
181 fprintf(stderr, ".\n");
182 if (other_cmds.cnt) {
183 fprintf(stderr, _("Available custom strategies are:"));
184 for (i = 0; i < other_cmds.cnt; i++)
185 fprintf(stderr, " %s", other_cmds.names[i]->name);
186 fprintf(stderr, ".\n");
187 }
188 exit(1);
189 }
190 ret = xcalloc(1, sizeof(struct strategy));
192 ret->name = xstrdup(name);
193 ret->attr = NO_TRIVIAL;
194 return ret;
195}
196static void append_strategy(struct strategy *s)
198{
199 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
200 use_strategies[use_strategies_nr++] = s;
201}
202static int option_parse_strategy(const struct option *opt,
204 const char *name, int unset)
205{
206 if (unset)
207 return 0;
208 append_strategy(get_strategy(name));
210 return 0;
211}
212static int option_parse_x(const struct option *opt,
214 const char *arg, int unset)
215{
216 if (unset)
217 return 0;
218 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
220 xopts[xopts_nr++] = xstrdup(arg);
221 return 0;
222}
223static int option_parse_n(const struct option *opt,
225 const char *arg, int unset)
226{
227 show_diffstat = unset;
228 return 0;
229}
230static struct option builtin_merge_options[] = {
232 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
233 N_("do not show a diffstat at the end of the merge"),
234 PARSE_OPT_NOARG, option_parse_n },
235 OPT_BOOL(0, "stat", &show_diffstat,
236 N_("show a diffstat at the end of the merge")),
237 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
238 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
239 N_("add (at most <n>) entries from shortlog to merge commit message"),
240 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
241 OPT_BOOL(0, "squash", &squash,
242 N_("create a single commit instead of doing a merge")),
243 OPT_BOOL(0, "commit", &option_commit,
244 N_("perform a commit if the merge succeeds (default)")),
245 OPT_BOOL('e', "edit", &option_edit,
246 N_("edit message before committing")),
247 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
248 OPT_SET_INT_F(0, "ff-only", &fast_forward,
249 N_("abort if fast-forward is not possible"),
250 FF_ONLY, PARSE_OPT_NONEG),
251 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
252 OPT_BOOL(0, "verify-signatures", &verify_signatures,
253 N_("verify that the named commit has a valid GPG signature")),
254 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
255 N_("merge strategy to use"), option_parse_strategy),
256 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
257 N_("option for selected merge strategy"), option_parse_x),
258 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
259 N_("merge commit message (for a non-fast-forward merge)"),
260 option_parse_message),
261 { OPTION_LOWLEVEL_CALLBACK, 'F', "file", &merge_msg, N_("path"),
262 N_("read message from file"), PARSE_OPT_NONEG,
263 (parse_opt_cb *) option_read_message },
264 OPT__VERBOSITY(&verbosity),
265 OPT_BOOL(0, "abort", &abort_current_merge,
266 N_("abort the current in-progress merge")),
267 OPT_BOOL(0, "continue", &continue_current_merge,
268 N_("continue the current in-progress merge")),
269 OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
270 N_("allow merging unrelated histories")),
271 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
272 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
273 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
274 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
275 OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
276 OPT_BOOL(0, "verify", &verify_msg, N_("verify commit-msg hook")),
277 OPT_END()
278};
279/* Cleans up metadata that is uninteresting after a succeeded merge. */
281static void drop_save(void)
282{
283 unlink(git_path_merge_head(the_repository));
284 unlink(git_path_merge_msg(the_repository));
285 unlink(git_path_merge_mode(the_repository));
286}
287static int save_state(struct object_id *stash)
289{
290 int len;
291 struct child_process cp = CHILD_PROCESS_INIT;
292 struct strbuf buffer = STRBUF_INIT;
293 const char *argv[] = {"stash", "create", NULL};
294 int rc = -1;
295 cp.argv = argv;
297 cp.out = -1;
298 cp.git_cmd = 1;
299 if (start_command(&cp))
301 die(_("could not run stash."));
302 len = strbuf_read(&buffer, cp.out, 1024);
303 close(cp.out);
304 if (finish_command(&cp) || len < 0)
306 die(_("stash failed"));
307 else if (!len) /* no changes */
308 goto out;
309 strbuf_setlen(&buffer, buffer.len-1);
310 if (get_oid(buffer.buf, stash))
311 die(_("not a valid object: %s"), buffer.buf);
312 rc = 0;
313out:
314 strbuf_release(&buffer);
315 return rc;
316}
317static void read_empty(const struct object_id *oid, int verbose)
319{
320 int i = 0;
321 const char *args[7];
322 args[i++] = "read-tree";
324 if (verbose)
325 args[i++] = "-v";
326 args[i++] = "-m";
327 args[i++] = "-u";
328 args[i++] = empty_tree_oid_hex();
329 args[i++] = oid_to_hex(oid);
330 args[i] = NULL;
331 if (run_command_v_opt(args, RUN_GIT_CMD))
333 die(_("read-tree failed"));
334}
335static void reset_hard(const struct object_id *oid, int verbose)
337{
338 int i = 0;
339 const char *args[6];
340 args[i++] = "read-tree";
342 if (verbose)
343 args[i++] = "-v";
344 args[i++] = "--reset";
345 args[i++] = "-u";
346 args[i++] = oid_to_hex(oid);
347 args[i] = NULL;
348 if (run_command_v_opt(args, RUN_GIT_CMD))
350 die(_("read-tree failed"));
351}
352static void restore_state(const struct object_id *head,
354 const struct object_id *stash)
355{
356 struct strbuf sb = STRBUF_INIT;
357 const char *args[] = { "stash", "apply", NULL, NULL };
358 if (is_null_oid(stash))
360 return;
361 reset_hard(head, 1);
363 args[2] = oid_to_hex(stash);
365 /*
367 * It is OK to ignore error here, for example when there was
368 * nothing to restore.
369 */
370 run_command_v_opt(args, RUN_GIT_CMD);
371 strbuf_release(&sb);
373 refresh_cache(REFRESH_QUIET);
374}
375/* This is called when no merge was necessary. */
377static void finish_up_to_date(const char *msg)
378{
379 if (verbosity >= 0)
380 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
381 drop_save();
382}
383static void squash_message(struct commit *commit, struct commit_list *remoteheads)
385{
386 struct rev_info rev;
387 struct strbuf out = STRBUF_INIT;
388 struct commit_list *j;
389 struct pretty_print_context ctx = {0};
390 printf(_("Squash commit -- not updating HEAD\n"));
392 repo_init_revisions(the_repository, &rev, NULL);
394 rev.ignore_merges = 1;
395 rev.commit_format = CMIT_FMT_MEDIUM;
396 commit->object.flags |= UNINTERESTING;
398 add_pending_object(&rev, &commit->object, NULL);
399 for (j = remoteheads; j; j = j->next)
401 add_pending_object(&rev, &j->item->object, NULL);
402 setup_revisions(0, NULL, &rev, NULL);
404 if (prepare_revision_walk(&rev))
405 die(_("revision walk setup failed"));
406 ctx.abbrev = rev.abbrev;
408 ctx.date_mode = rev.date_mode;
409 ctx.fmt = rev.commit_format;
410 strbuf_addstr(&out, "Squashed commit of the following:\n");
412 while ((commit = get_revision(&rev)) != NULL) {
413 strbuf_addch(&out, '\n');
414 strbuf_addf(&out, "commit %s\n",
415 oid_to_hex(&commit->object.oid));
416 pretty_print_commit(&ctx, commit, &out);
417 }
418 write_file_buf(git_path_squash_msg(the_repository), out.buf, out.len);
419 strbuf_release(&out);
420}
421static void finish(struct commit *head_commit,
423 struct commit_list *remoteheads,
424 const struct object_id *new_head, const char *msg)
425{
426 struct strbuf reflog_message = STRBUF_INIT;
427 const struct object_id *head = &head_commit->object.oid;
428 if (!msg)
430 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
431 else {
432 if (verbosity >= 0)
433 printf("%s\n", msg);
434 strbuf_addf(&reflog_message, "%s: %s",
435 getenv("GIT_REFLOG_ACTION"), msg);
436 }
437 if (squash) {
438 squash_message(head_commit, remoteheads);
439 } else {
440 if (verbosity >= 0 && !merge_msg.len)
441 printf(_("No merge message -- not updating HEAD\n"));
442 else {
443 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
444 update_ref(reflog_message.buf, "HEAD", new_head, head,
445 0, UPDATE_REFS_DIE_ON_ERR);
446 /*
447 * We ignore errors in 'gc --auto', since the
448 * user should see them.
449 */
450 close_all_packs(the_repository->objects);
451 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
452 }
453 }
454 if (new_head && show_diffstat) {
455 struct diff_options opts;
456 repo_diff_setup(the_repository, &opts);
457 opts.stat_width = -1; /* use full terminal width */
458 opts.stat_graph_width = -1; /* respect statGraphWidth config */
459 opts.output_format |=
460 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
461 opts.detect_rename = DIFF_DETECT_RENAME;
462 diff_setup_done(&opts);
463 diff_tree_oid(head, new_head, "", &opts);
464 diffcore_std(&opts);
465 diff_flush(&opts);
466 }
467 /* Run a post-merge hook */
469 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
470 strbuf_release(&reflog_message);
472}
473/* Get the name for the merge commit's message. */
475static void merge_name(const char *remote, struct strbuf *msg)
476{
477 struct commit *remote_head;
478 struct object_id branch_head;
479 struct strbuf buf = STRBUF_INIT;
480 struct strbuf bname = STRBUF_INIT;
481 struct merge_remote_desc *desc;
482 const char *ptr;
483 char *found_ref;
484 int len, early;
485 strbuf_branchname(&bname, remote, 0);
487 remote = bname.buf;
488 oidclr(&branch_head);
490 remote_head = get_merge_parent(remote);
491 if (!remote_head)
492 die(_("'%s' does not point to a commit"), remote);
493 if (dwim_ref(remote, strlen(remote), &branch_head, &found_ref) > 0) {
495 if (starts_with(found_ref, "refs/heads/")) {
496 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
497 oid_to_hex(&branch_head), remote);
498 goto cleanup;
499 }
500 if (starts_with(found_ref, "refs/tags/")) {
501 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
502 oid_to_hex(&branch_head), remote);
503 goto cleanup;
504 }
505 if (starts_with(found_ref, "refs/remotes/")) {
506 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
507 oid_to_hex(&branch_head), remote);
508 goto cleanup;
509 }
510 }
511 /* See if remote matches <name>^^^.. or <name>~<number> */
513 for (len = 0, ptr = remote + strlen(remote);
514 remote < ptr && ptr[-1] == '^';
515 ptr--)
516 len++;
517 if (len)
518 early = 1;
519 else {
520 early = 0;
521 ptr = strrchr(remote, '~');
522 if (ptr) {
523 int seen_nonzero = 0;
524 len++; /* count ~ */
526 while (*++ptr && isdigit(*ptr)) {
527 seen_nonzero |= (*ptr != '0');
528 len++;
529 }
530 if (*ptr)
531 len = 0; /* not ...~<number> */
532 else if (seen_nonzero)
533 early = 1;
534 else if (len == 1)
535 early = 1; /* "name~" is "name~1"! */
536 }
537 }
538 if (len) {
539 struct strbuf truname = STRBUF_INIT;
540 strbuf_addf(&truname, "refs/heads/%s", remote);
541 strbuf_setlen(&truname, truname.len - len);
542 if (ref_exists(truname.buf)) {
543 strbuf_addf(msg,
544 "%s\t\tbranch '%s'%s of .\n",
545 oid_to_hex(&remote_head->object.oid),
546 truname.buf + 11,
547 (early ? " (early part)" : ""));
548 strbuf_release(&truname);
549 goto cleanup;
550 }
551 strbuf_release(&truname);
552 }
553 desc = merge_remote_util(remote_head);
555 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
556 strbuf_addf(msg, "%s\t\t%s '%s'\n",
557 oid_to_hex(&desc->obj->oid),
558 type_name(desc->obj->type),
559 remote);
560 goto cleanup;
561 }
562 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
564 oid_to_hex(&remote_head->object.oid), remote);
565cleanup:
566 strbuf_release(&buf);
567 strbuf_release(&bname);
568}
569static void parse_branch_merge_options(char *bmo)
571{
572 const char **argv;
573 int argc;
574 if (!bmo)
576 return;
577 argc = split_cmdline(bmo, &argv);
578 if (argc < 0)
579 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
580 _(split_cmdline_strerror(argc)));
581 REALLOC_ARRAY(argv, argc + 2);
582 MOVE_ARRAY(argv + 1, argv, argc + 1);
583 argc++;
584 argv[0] = "branch.*.mergeoptions";
585 parse_options(argc, argv, NULL, builtin_merge_options,
586 builtin_merge_usage, 0);
587 free(argv);
588}
589static int git_merge_config(const char *k, const char *v, void *cb)
591{
592 int status;
593 if (branch && starts_with(k, "branch.") &&
595 starts_with(k + 7, branch) &&
596 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
597 free(branch_mergeoptions);
598 branch_mergeoptions = xstrdup(v);
599 return 0;
600 }
601 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
603 show_diffstat = git_config_bool(k, v);
604 else if (!strcmp(k, "merge.verifysignatures"))
605 verify_signatures = git_config_bool(k, v);
606 else if (!strcmp(k, "pull.twohead"))
607 return git_config_string(&pull_twohead, k, v);
608 else if (!strcmp(k, "pull.octopus"))
609 return git_config_string(&pull_octopus, k, v);
610 else if (!strcmp(k, "merge.renormalize"))
611 option_renormalize = git_config_bool(k, v);
612 else if (!strcmp(k, "merge.ff")) {
613 int boolval = git_parse_maybe_bool(v);
614 if (0 <= boolval) {
615 fast_forward = boolval ? FF_ALLOW : FF_NO;
616 } else if (v && !strcmp(v, "only")) {
617 fast_forward = FF_ONLY;
618 } /* do not barf on values from future versions of git */
619 return 0;
620 } else if (!strcmp(k, "merge.defaulttoupstream")) {
621 default_to_upstream = git_config_bool(k, v);
622 return 0;
623 } else if (!strcmp(k, "commit.gpgsign")) {
624 sign_commit = git_config_bool(k, v) ? "" : NULL;
625 return 0;
626 }
627 status = fmt_merge_msg_config(k, v, cb);
629 if (status)
630 return status;
631 status = git_gpg_config(k, v, NULL);
632 if (status)
633 return status;
634 return git_diff_ui_config(k, v, cb);
635}
636static int read_tree_trivial(struct object_id *common, struct object_id *head,
638 struct object_id *one)
639{
640 int i, nr_trees = 0;
641 struct tree *trees[MAX_UNPACK_TREES];
642 struct tree_desc t[MAX_UNPACK_TREES];
643 struct unpack_trees_options opts;
644 memset(&opts, 0, sizeof(opts));
646 opts.head_idx = 2;
647 opts.src_index = &the_index;
648 opts.dst_index = &the_index;
649 opts.update = 1;
650 opts.verbose_update = 1;
651 opts.trivial_merges_only = 1;
652 opts.merge = 1;
653 trees[nr_trees] = parse_tree_indirect(common);
654 if (!trees[nr_trees++])
655 return -1;
656 trees[nr_trees] = parse_tree_indirect(head);
657 if (!trees[nr_trees++])
658 return -1;
659 trees[nr_trees] = parse_tree_indirect(one);
660 if (!trees[nr_trees++])
661 return -1;
662 opts.fn = threeway_merge;
663 cache_tree_free(&active_cache_tree);
664 for (i = 0; i < nr_trees; i++) {
665 parse_tree(trees[i]);
666 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
667 }
668 if (unpack_trees(nr_trees, t, &opts))
669 return -1;
670 return 0;
671}
672static void write_tree_trivial(struct object_id *oid)
674{
675 if (write_cache_as_tree(oid, 0, NULL))
676 die(_("git write-tree failed to write a tree"));
677}
678static int try_merge_strategy(const char *strategy, struct commit_list *common,
680 struct commit_list *remoteheads,
681 struct commit *head)
682{
683 struct lock_file lock = LOCK_INIT;
684 const char *head_arg = "HEAD";
685 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
687 refresh_cache(REFRESH_QUIET);
688 if (write_locked_index(&the_index, &lock,
689 COMMIT_LOCK | SKIP_IF_UNCHANGED))
690 return error(_("Unable to write index."));
691 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
693 int clean, x;
694 struct commit *result;
695 struct commit_list *reversed = NULL;
696 struct merge_options o;
697 struct commit_list *j;
698 if (remoteheads->next) {
700 error(_("Not handling anything other than two heads merge."));
701 return 2;
702 }
703 init_merge_options(&o);
705 if (!strcmp(strategy, "subtree"))
706 o.subtree_shift = "";
707 o.renormalize = option_renormalize;
709 o.show_rename_progress =
710 show_progress == -1 ? isatty(2) : show_progress;
711 for (x = 0; x < xopts_nr; x++)
713 if (parse_merge_opt(&o, xopts[x]))
714 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
715 o.branch1 = head_arg;
717 o.branch2 = merge_remote_util(remoteheads->item)->name;
718 for (j = common; j; j = j->next)
720 commit_list_insert(j->item, &reversed);
721 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
723 clean = merge_recursive(&o, head,
724 remoteheads->item, reversed, &result);
725 if (clean < 0)
726 exit(128);
727 if (write_locked_index(&the_index, &lock,
728 COMMIT_LOCK | SKIP_IF_UNCHANGED))
729 die(_("unable to write %s"), get_index_file());
730 return clean ? 0 : 1;
731 } else {
732 return try_merge_command(the_repository,
733 strategy, xopts_nr, xopts,
734 common, head_arg, remoteheads);
735 }
736}
737static void count_diff_files(struct diff_queue_struct *q,
739 struct diff_options *opt, void *data)
740{
741 int *count = data;
742 (*count) += q->nr;
744}
745static int count_unmerged_entries(void)
747{
748 int i, ret = 0;
749 for (i = 0; i < active_nr; i++)
751 if (ce_stage(active_cache[i]))
752 ret++;
753 return ret;
755}
756static void add_strategies(const char *string, unsigned attr)
758{
759 int i;
760 if (string) {
762 struct string_list list = STRING_LIST_INIT_DUP;
763 struct string_list_item *item;
764 string_list_split(&list, string, ' ', -1);
765 for_each_string_list_item(item, &list)
766 append_strategy(get_strategy(item->string));
767 string_list_clear(&list, 0);
768 return;
769 }
770 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
771 if (all_strategy[i].attr & attr)
772 append_strategy(&all_strategy[i]);
773}
775static void read_merge_msg(struct strbuf *msg)
777{
778 const char *filename = git_path_merge_msg(the_repository);
779 strbuf_reset(msg);
780 if (strbuf_read_file(msg, filename, 0) < 0)
781 die_errno(_("Could not read from '%s'"), filename);
782}
783static void write_merge_state(struct commit_list *);
785static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
786{
787 if (err_msg)
788 error("%s", err_msg);
789 fprintf(stderr,
790 _("Not committing merge; use 'git commit' to complete the merge.\n"));
791 write_merge_state(remoteheads);
792 exit(1);
793}
794static const char merge_editor_comment[] =
796N_("Please enter a commit message to explain why this merge is necessary,\n"
797 "especially if it merges an updated upstream into a topic branch.\n"
798 "\n"
799 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
800 "the commit.\n");
801static void write_merge_heads(struct commit_list *);
803static void prepare_to_commit(struct commit_list *remoteheads)
804{
805 struct strbuf msg = STRBUF_INIT;
806 strbuf_addbuf(&msg, &merge_msg);
807 strbuf_addch(&msg, '\n');
808 if (squash)
809 BUG("the control must not reach here under --squash");
810 if (0 < option_edit)
811 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
812 if (signoff)
813 append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
814 write_merge_heads(remoteheads);
815 write_file_buf(git_path_merge_msg(the_repository), msg.buf, msg.len);
816 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
817 git_path_merge_msg(the_repository), "merge", NULL))
818 abort_commit(remoteheads, NULL);
819 if (0 < option_edit) {
820 if (launch_editor(git_path_merge_msg(the_repository), NULL, NULL))
821 abort_commit(remoteheads, NULL);
822 }
823 if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
825 "commit-msg",
826 git_path_merge_msg(the_repository), NULL))
827 abort_commit(remoteheads, NULL);
828 read_merge_msg(&msg);
830 strbuf_stripspace(&msg, 0 < option_edit);
831 if (!msg.len)
832 abort_commit(remoteheads, _("Empty commit message."));
833 strbuf_release(&merge_msg);
834 strbuf_addbuf(&merge_msg, &msg);
835 strbuf_release(&msg);
836}
837static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
839{
840 struct object_id result_tree, result_commit;
841 struct commit_list *parents, **pptr = &parents;
842 struct lock_file lock = LOCK_INIT;
843 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
845 refresh_cache(REFRESH_QUIET);
846 if (write_locked_index(&the_index, &lock,
847 COMMIT_LOCK | SKIP_IF_UNCHANGED))
848 return error(_("Unable to write index."));
849 write_tree_trivial(&result_tree);
851 printf(_("Wonderful.\n"));
852 pptr = commit_list_append(head, pptr);
853 pptr = commit_list_append(remoteheads->item, pptr);
854 prepare_to_commit(remoteheads);
855 if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
856 &result_commit, NULL, sign_commit))
857 die(_("failed to write commit object"));
858 finish(head, remoteheads, &result_commit, "In-index merge");
859 drop_save();
860 return 0;
861}
862static int finish_automerge(struct commit *head,
864 int head_subsumed,
865 struct commit_list *common,
866 struct commit_list *remoteheads,
867 struct object_id *result_tree,
868 const char *wt_strategy)
869{
870 struct commit_list *parents = NULL;
871 struct strbuf buf = STRBUF_INIT;
872 struct object_id result_commit;
873 free_commit_list(common);
875 parents = remoteheads;
876 if (!head_subsumed || fast_forward == FF_NO)
877 commit_list_insert(head, &parents);
878 strbuf_addch(&merge_msg, '\n');
879 prepare_to_commit(remoteheads);
880 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
881 &result_commit, NULL, sign_commit))
882 die(_("failed to write commit object"));
883 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
884 finish(head, remoteheads, &result_commit, buf.buf);
885 strbuf_release(&buf);
886 drop_save();
887 return 0;
888}
889static int suggest_conflicts(void)
891{
892 const char *filename;
893 FILE *fp;
894 struct strbuf msgbuf = STRBUF_INIT;
895 filename = git_path_merge_msg(the_repository);
897 fp = xfopen(filename, "a");
898 append_conflicts_hint(&msgbuf);
900 fputs(msgbuf.buf, fp);
901 strbuf_release(&msgbuf);
902 fclose(fp);
903 repo_rerere(the_repository, allow_rerere_auto);
904 printf(_("Automatic merge failed; "
905 "fix conflicts and then commit the result.\n"));
906 return 1;
907}
908static int evaluate_result(void)
910{
911 int cnt = 0;
912 struct rev_info rev;
913 /* Check how many files differ. */
915 repo_init_revisions(the_repository, &rev, "");
916 setup_revisions(0, NULL, &rev, NULL);
917 rev.diffopt.output_format |=
918 DIFF_FORMAT_CALLBACK;
919 rev.diffopt.format_callback = count_diff_files;
920 rev.diffopt.format_callback_data = &cnt;
921 run_diff_files(&rev, 0);
922 /*
924 * Check how many unmerged entries are
925 * there.
926 */
927 cnt += count_unmerged_entries();
928 return cnt;
930}
931/*
933 * Pretend as if the user told us to merge with the remote-tracking
934 * branch we have for the upstream of the current branch
935 */
936static int setup_with_upstream(const char ***argv)
937{
938 struct branch *branch = branch_get(NULL);
939 int i;
940 const char **args;
941 if (!branch)
943 die(_("No current branch."));
944 if (!branch->remote_name)
945 die(_("No remote for the current branch."));
946 if (!branch->merge_nr)
947 die(_("No default upstream defined for the current branch."));
948 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
950 for (i = 0; i < branch->merge_nr; i++) {
951 if (!branch->merge[i]->dst)
952 die(_("No remote-tracking branch for %s from %s"),
953 branch->merge[i]->src, branch->remote_name);
954 args[i] = branch->merge[i]->dst;
955 }
956 args[i] = NULL;
957 *argv = args;
958 return i;
959}
960static void write_merge_heads(struct commit_list *remoteheads)
962{
963 struct commit_list *j;
964 struct strbuf buf = STRBUF_INIT;
965 for (j = remoteheads; j; j = j->next) {
967 struct object_id *oid;
968 struct commit *c = j->item;
969 struct merge_remote_desc *desc;
970 desc = merge_remote_util(c);
972 if (desc && desc->obj) {
973 oid = &desc->obj->oid;
974 } else {
975 oid = &c->object.oid;
976 }
977 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
978 }
979 write_file_buf(git_path_merge_head(the_repository), buf.buf, buf.len);
980 strbuf_reset(&buf);
982 if (fast_forward == FF_NO)
983 strbuf_addstr(&buf, "no-ff");
984 write_file_buf(git_path_merge_mode(the_repository), buf.buf, buf.len);
985 strbuf_release(&buf);
986}
987static void write_merge_state(struct commit_list *remoteheads)
989{
990 write_merge_heads(remoteheads);
991 strbuf_addch(&merge_msg, '\n');
992 write_file_buf(git_path_merge_msg(the_repository), merge_msg.buf,
993 merge_msg.len);
994}
995static int default_edit_option(void)
997{
998 static const char name[] = "GIT_MERGE_AUTOEDIT";
999 const char *e = getenv(name);
1000 struct stat st_stdin, st_stdout;
1001 if (have_message)
1003 /* an explicit -m msg without --[no-]edit */
1004 return 0;
1005 if (e) {
1007 int v = git_parse_maybe_bool(e);
1008 if (v < 0)
1009 die(_("Bad value '%s' in environment '%s'"), e, name);
1010 return v;
1011 }
1012 /* Use editor if stdin and stdout are the same and is a tty */
1014 return (!fstat(0, &st_stdin) &&
1015 !fstat(1, &st_stdout) &&
1016 isatty(0) && isatty(1) &&
1017 st_stdin.st_dev == st_stdout.st_dev &&
1018 st_stdin.st_ino == st_stdout.st_ino &&
1019 st_stdin.st_mode == st_stdout.st_mode);
1020}
1021static struct commit_list *reduce_parents(struct commit *head_commit,
1023 int *head_subsumed,
1024 struct commit_list *remoteheads)
1025{
1026 struct commit_list *parents, **remotes;
1027 /*
1029 * Is the current HEAD reachable from another commit being
1030 * merged? If so we do not want to record it as a parent of
1031 * the resulting merge, unless --no-ff is given. We will flip
1032 * this variable to 0 when we find HEAD among the independent
1033 * tips being merged.
1034 */
1035 *head_subsumed = 1;
1036 /* Find what parents to record by checking independent ones. */
1038 parents = reduce_heads(remoteheads);
1039 free_commit_list(remoteheads);
1040 remoteheads = NULL;
1042 remotes = &remoteheads;
1043 while (parents) {
1044 struct commit *commit = pop_commit(&parents);
1045 if (commit == head_commit)
1046 *head_subsumed = 0;
1047 else
1048 remotes = &commit_list_insert(commit, remotes)->next;
1049 }
1050 return remoteheads;
1051}
1052static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1054{
1055 struct fmt_merge_msg_opts opts;
1056 memset(&opts, 0, sizeof(opts));
1058 opts.add_title = !have_message;
1059 opts.shortlog_len = shortlog_len;
1060 opts.credit_people = (0 < option_edit);
1061 fmt_merge_msg(merge_names, merge_msg, &opts);
1063 if (merge_msg->len)
1064 strbuf_setlen(merge_msg, merge_msg->len - 1);
1065}
1066static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1068{
1069 const char *filename;
1070 int fd, pos, npos;
1071 struct strbuf fetch_head_file = STRBUF_INIT;
1072 const unsigned hexsz = the_hash_algo->hexsz;
1073 if (!merge_names)
1075 merge_names = &fetch_head_file;
1076 filename = git_path_fetch_head(the_repository);
1078 fd = open(filename, O_RDONLY);
1079 if (fd < 0)
1080 die_errno(_("could not open '%s' for reading"), filename);
1081 if (strbuf_read(merge_names, fd, 0) < 0)
1083 die_errno(_("could not read '%s'"), filename);
1084 if (close(fd) < 0)
1085 die_errno(_("could not close '%s'"), filename);
1086 for (pos = 0; pos < merge_names->len; pos = npos) {
1088 struct object_id oid;
1089 char *ptr;
1090 struct commit *commit;
1091 ptr = strchr(merge_names->buf + pos, '\n');
1093 if (ptr)
1094 npos = ptr - merge_names->buf + 1;
1095 else
1096 npos = merge_names->len;
1097 if (npos - pos < hexsz + 2 ||
1099 get_oid_hex(merge_names->buf + pos, &oid))
1100 commit = NULL; /* bad */
1101 else if (memcmp(merge_names->buf + pos + hexsz, "\t\t", 2))
1102 continue; /* not-for-merge */
1103 else {
1104 char saved = merge_names->buf[pos + hexsz];
1105 merge_names->buf[pos + hexsz] = '\0';
1106 commit = get_merge_parent(merge_names->buf + pos);
1107 merge_names->buf[pos + hexsz] = saved;
1108 }
1109 if (!commit) {
1110 if (ptr)
1111 *ptr = '\0';
1112 die(_("not something we can merge in %s: %s"),
1113 filename, merge_names->buf + pos);
1114 }
1115 remotes = &commit_list_insert(commit, remotes)->next;
1116 }
1117 if (merge_names == &fetch_head_file)
1119 strbuf_release(&fetch_head_file);
1120}
1121static struct commit_list *collect_parents(struct commit *head_commit,
1123 int *head_subsumed,
1124 int argc, const char **argv,
1125 struct strbuf *merge_msg)
1126{
1127 int i;
1128 struct commit_list *remoteheads = NULL;
1129 struct commit_list **remotes = &remoteheads;
1130 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1131 if (merge_msg && (!have_message || shortlog_len))
1133 autogen = &merge_names;
1134 if (head_commit)
1136 remotes = &commit_list_insert(head_commit, remotes)->next;
1137 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1139 handle_fetch_head(remotes, autogen);
1140 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1141 } else {
1142 for (i = 0; i < argc; i++) {
1143 struct commit *commit = get_merge_parent(argv[i]);
1144 if (!commit)
1145 help_unknown_ref(argv[i], "merge",
1146 _("not something we can merge"));
1147 remotes = &commit_list_insert(commit, remotes)->next;
1148 }
1149 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1150 if (autogen) {
1151 struct commit_list *p;
1152 for (p = remoteheads; p; p = p->next)
1153 merge_name(merge_remote_util(p->item)->name, autogen);
1154 }
1155 }
1156 if (autogen) {
1158 prepare_merge_message(autogen, merge_msg);
1159 strbuf_release(autogen);
1160 }
1161 return remoteheads;
1163}
1164static int merging_a_throwaway_tag(struct commit *commit)
1166{
1167 char *tag_ref;
1168 struct object_id oid;
1169 int is_throwaway_tag = 0;
1170 /* Are we merging a tag? */
1172 if (!merge_remote_util(commit) ||
1173 !merge_remote_util(commit)->obj ||
1174 merge_remote_util(commit)->obj->type != OBJ_TAG)
1175 return is_throwaway_tag;
1176 /*
1178 * Now we know we are merging a tag object. Are we downstream
1179 * and following the tags from upstream? If so, we must have
1180 * the tag object pointed at by "refs/tags/$T" where $T is the
1181 * tagname recorded in the tag object. We want to allow such
1182 * a "just to catch up" merge to fast-forward.
1183 *
1184 * Otherwise, we are playing an integrator's role, making a
1185 * merge with a throw-away tag from a contributor with
1186 * something like "git pull $contributor $signed_tag".
1187 * We want to forbid such a merge from fast-forwarding
1188 * by default; otherwise we would not keep the signature
1189 * anywhere.
1190 */
1191 tag_ref = xstrfmt("refs/tags/%s",
1192 ((struct tag *)merge_remote_util(commit)->obj)->tag);
1193 if (!read_ref(tag_ref, &oid) &&
1194 oideq(&oid, &merge_remote_util(commit)->obj->oid))
1195 is_throwaway_tag = 0;
1196 else
1197 is_throwaway_tag = 1;
1198 free(tag_ref);
1199 return is_throwaway_tag;
1200}
1201int cmd_merge(int argc, const char **argv, const char *prefix)
1203{
1204 struct object_id result_tree, stash, head_oid;
1205 struct commit *head_commit;
1206 struct strbuf buf = STRBUF_INIT;
1207 int i, ret = 0, head_subsumed;
1208 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1209 struct commit_list *common = NULL;
1210 const char *best_strategy = NULL, *wt_strategy = NULL;
1211 struct commit_list *remoteheads, *p;
1212 void *branch_to_free;
1213 int orig_argc = argc;
1214 if (argc == 2 && !strcmp(argv[1], "-h"))
1216 usage_with_options(builtin_merge_usage, builtin_merge_options);
1217 /*
1219 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1220 * current branch.
1221 */
1222 branch = branch_to_free = resolve_refdup("HEAD", 0, &head_oid, NULL);
1223 if (branch)
1224 skip_prefix(branch, "refs/heads/", &branch);
1225 init_diff_ui_defaults();
1227 git_config(git_merge_config, NULL);
1228 if (!branch || is_null_oid(&head_oid))
1230 head_commit = NULL;
1231 else
1232 head_commit = lookup_commit_or_die(&head_oid, "HEAD");
1233 if (branch_mergeoptions)
1235 parse_branch_merge_options(branch_mergeoptions);
1236 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1237 builtin_merge_usage, 0);
1238 if (shortlog_len < 0)
1239 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1240 if (verbosity < 0 && show_progress == -1)
1242 show_progress = 0;
1243 if (abort_current_merge) {
1245 int nargc = 2;
1246 const char *nargv[] = {"reset", "--merge", NULL};
1247 if (orig_argc != 2)
1249 usage_msg_opt(_("--abort expects no arguments"),
1250 builtin_merge_usage, builtin_merge_options);
1251 if (!file_exists(git_path_merge_head(the_repository)))
1253 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1254 /* Invoke 'git reset --merge' */
1256 ret = cmd_reset(nargc, nargv, prefix);
1257 goto done;
1258 }
1259 if (continue_current_merge) {
1261 int nargc = 1;
1262 const char *nargv[] = {"commit", NULL};
1263 if (orig_argc != 2)
1265 usage_msg_opt(_("--continue expects no arguments"),
1266 builtin_merge_usage, builtin_merge_options);
1267 if (!file_exists(git_path_merge_head(the_repository)))
1269 die(_("There is no merge in progress (MERGE_HEAD missing)."));
1270 /* Invoke 'git commit' */
1272 ret = cmd_commit(nargc, nargv, prefix);
1273 goto done;
1274 }
1275 if (read_cache_unmerged())
1277 die_resolve_conflict("merge");
1278 if (file_exists(git_path_merge_head(the_repository))) {
1280 /*
1281 * There is no unmerged entry, don't advise 'git
1282 * add/rm <file>', just 'git commit'.
1283 */
1284 if (advice_resolve_conflict)
1285 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1286 "Please, commit your changes before you merge."));
1287 else
1288 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1289 }
1290 if (file_exists(git_path_cherry_pick_head(the_repository))) {
1291 if (advice_resolve_conflict)
1292 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1293 "Please, commit your changes before you merge."));
1294 else
1295 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1296 }
1297 resolve_undo_clear();
1298 if (verbosity < 0)
1300 show_diffstat = 0;
1301 if (squash) {
1303 if (fast_forward == FF_NO)
1304 die(_("You cannot combine --squash with --no-ff."));
1305 option_commit = 0;
1306 }
1307 if (!argc) {
1309 if (default_to_upstream)
1310 argc = setup_with_upstream(&argv);
1311 else
1312 die(_("No commit specified and merge.defaultToUpstream not set."));
1313 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1314 argv[0] = "@{-1}";
1315 }
1316 if (!argc)
1318 usage_with_options(builtin_merge_usage,
1319 builtin_merge_options);
1320 if (!head_commit) {
1322 /*
1323 * If the merged head is a valid one there is no reason
1324 * to forbid "git merge" into a branch yet to be born.
1325 * We do the same for "git pull".
1326 */
1327 struct object_id *remote_head_oid;
1328 if (squash)
1329 die(_("Squash commit into empty head not supported yet"));
1330 if (fast_forward == FF_NO)
1331 die(_("Non-fast-forward commit does not make sense into "
1332 "an empty head"));
1333 remoteheads = collect_parents(head_commit, &head_subsumed,
1334 argc, argv, NULL);
1335 if (!remoteheads)
1336 die(_("%s - not something we can merge"), argv[0]);
1337 if (remoteheads->next)
1338 die(_("Can merge only exactly one commit into empty head"));
1339 remote_head_oid = &remoteheads->item->object.oid;
1340 read_empty(remote_head_oid, 0);
1341 update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
1342 UPDATE_REFS_DIE_ON_ERR);
1343 goto done;
1344 }
1345 /*
1347 * All the rest are the commits being merged; prepare
1348 * the standard merge summary message to be appended
1349 * to the given message.
1350 */
1351 remoteheads = collect_parents(head_commit, &head_subsumed,
1352 argc, argv, &merge_msg);
1353 if (!head_commit || !argc)
1355 usage_with_options(builtin_merge_usage,
1356 builtin_merge_options);
1357 if (verify_signatures) {
1359 for (p = remoteheads; p; p = p->next) {
1360 struct commit *commit = p->item;
1361 char hex[GIT_MAX_HEXSZ + 1];
1362 struct signature_check signature_check;
1363 memset(&signature_check, 0, sizeof(signature_check));
1364 check_commit_signature(commit, &signature_check);
1366 find_unique_abbrev_r(hex, &commit->object.oid, DEFAULT_ABBREV);
1368 switch (signature_check.result) {
1369 case 'G':
1370 break;
1371 case 'U':
1372 die(_("Commit %s has an untrusted GPG signature, "
1373 "allegedly by %s."), hex, signature_check.signer);
1374 case 'B':
1375 die(_("Commit %s has a bad GPG signature "
1376 "allegedly by %s."), hex, signature_check.signer);
1377 default: /* 'N' */
1378 die(_("Commit %s does not have a GPG signature."), hex);
1379 }
1380 if (verbosity >= 0 && signature_check.result == 'G')
1381 printf(_("Commit %s has a good GPG signature by %s\n"),
1382 hex, signature_check.signer);
1383 signature_check_clear(&signature_check);
1385 }
1386 }
1387 strbuf_addstr(&buf, "merge");
1389 for (p = remoteheads; p; p = p->next)
1390 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1391 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1392 strbuf_reset(&buf);
1393 for (p = remoteheads; p; p = p->next) {
1395 struct commit *commit = p->item;
1396 strbuf_addf(&buf, "GITHEAD_%s",
1397 oid_to_hex(&commit->object.oid));
1398 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1399 strbuf_reset(&buf);
1400 if (fast_forward != FF_ONLY && merging_a_throwaway_tag(commit))
1401 fast_forward = FF_NO;
1402 }
1403 if (option_edit < 0)
1405 option_edit = default_edit_option();
1406 if (!use_strategies) {
1408 if (!remoteheads)
1409 ; /* already up-to-date */
1410 else if (!remoteheads->next)
1411 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1412 else
1413 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1414 }
1415 for (i = 0; i < use_strategies_nr; i++) {
1417 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1418 fast_forward = FF_NO;
1419 if (use_strategies[i]->attr & NO_TRIVIAL)
1420 allow_trivial = 0;
1421 }
1422 if (!remoteheads)
1424 ; /* already up-to-date */
1425 else if (!remoteheads->next)
1426 common = get_merge_bases(head_commit, remoteheads->item);
1427 else {
1428 struct commit_list *list = remoteheads;
1429 commit_list_insert(head_commit, &list);
1430 common = get_octopus_merge_bases(list);
1431 free(list);
1432 }
1433 update_ref("updating ORIG_HEAD", "ORIG_HEAD",
1435 &head_commit->object.oid, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1436 if (remoteheads && !common) {
1438 /* No common ancestors found. */
1439 if (!allow_unrelated_histories)
1440 die(_("refusing to merge unrelated histories"));
1441 /* otherwise, we need a real merge. */
1442 } else if (!remoteheads ||
1443 (!remoteheads->next && !common->next &&
1444 common->item == remoteheads->item)) {
1445 /*
1446 * If head can reach all the merge then we are up to date.
1447 * but first the most common case of merging one remote.
1448 */
1449 finish_up_to_date(_("Already up to date."));
1450 goto done;
1451 } else if (fast_forward != FF_NO && !remoteheads->next &&
1452 !common->next &&
1453 oideq(&common->item->object.oid, &head_commit->object.oid)) {
1454 /* Again the most common case of merging one remote. */
1455 struct strbuf msg = STRBUF_INIT;
1456 struct commit *commit;
1457 if (verbosity >= 0) {
1459 printf(_("Updating %s..%s\n"),
1460 find_unique_abbrev(&head_commit->object.oid,
1461 DEFAULT_ABBREV),
1462 find_unique_abbrev(&remoteheads->item->object.oid,
1463 DEFAULT_ABBREV));
1464 }
1465 strbuf_addstr(&msg, "Fast-forward");
1466 if (have_message)
1467 strbuf_addstr(&msg,
1468 " (no commit created; -m option ignored)");
1469 commit = remoteheads->item;
1470 if (!commit) {
1471 ret = 1;
1472 goto done;
1473 }
1474 if (checkout_fast_forward(the_repository,
1476 &head_commit->object.oid,
1477 &commit->object.oid,
1478 overwrite_ignore)) {
1479 ret = 1;
1480 goto done;
1481 }
1482 finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
1484 drop_save();
1485 goto done;
1486 } else if (!remoteheads->next && common->next)
1487 ;
1488 /*
1489 * We are not doing octopus and not fast-forward. Need
1490 * a real merge.
1491 */
1492 else if (!remoteheads->next && !common->next && option_commit) {
1493 /*
1494 * We are not doing octopus, not fast-forward, and have
1495 * only one common.
1496 */
1497 refresh_cache(REFRESH_QUIET);
1498 if (allow_trivial && fast_forward != FF_ONLY) {
1499 /* See if it is really trivial. */
1500 git_committer_info(IDENT_STRICT);
1501 printf(_("Trying really trivial in-index merge...\n"));
1502 if (!read_tree_trivial(&common->item->object.oid,
1503 &head_commit->object.oid,
1504 &remoteheads->item->object.oid)) {
1505 ret = merge_trivial(head_commit, remoteheads);
1506 goto done;
1507 }
1508 printf(_("Nope.\n"));
1509 }
1510 } else {
1511 /*
1512 * An octopus. If we can reach all the remote we are up
1513 * to date.
1514 */
1515 int up_to_date = 1;
1516 struct commit_list *j;
1517 for (j = remoteheads; j; j = j->next) {
1519 struct commit_list *common_one;
1520 /*
1522 * Here we *have* to calculate the individual
1523 * merge_bases again, otherwise "git merge HEAD^
1524 * HEAD^^" would be missed.
1525 */
1526 common_one = get_merge_bases(head_commit, j->item);
1527 if (!oideq(&common_one->item->object.oid, &j->item->object.oid)) {
1528 up_to_date = 0;
1529 break;
1530 }
1531 }
1532 if (up_to_date) {
1533 finish_up_to_date(_("Already up to date. Yeeah!"));
1534 goto done;
1535 }
1536 }
1537 if (fast_forward == FF_ONLY)
1539 die(_("Not possible to fast-forward, aborting."));
1540 /* We are going to make a new commit. */
1542 git_committer_info(IDENT_STRICT);
1543 /*
1545 * At this point, we need a real merge. No matter what strategy
1546 * we use, it would operate on the index, possibly affecting the
1547 * working tree, and when resolved cleanly, have the desired
1548 * tree in the index -- this means that the index must be in
1549 * sync with the head commit. The strategies are responsible
1550 * to ensure this.
1551 */
1552 if (use_strategies_nr == 1 ||
1553 /*
1554 * Stash away the local changes so that we can try more than one.
1555 */
1556 save_state(&stash))
1557 oidclr(&stash);
1558 for (i = 0; i < use_strategies_nr; i++) {
1560 int ret;
1561 if (i) {
1562 printf(_("Rewinding the tree to pristine...\n"));
1563 restore_state(&head_commit->object.oid, &stash);
1564 }
1565 if (use_strategies_nr != 1)
1566 printf(_("Trying merge strategy %s...\n"),
1567 use_strategies[i]->name);
1568 /*
1569 * Remember which strategy left the state in the working
1570 * tree.
1571 */
1572 wt_strategy = use_strategies[i]->name;
1573 ret = try_merge_strategy(use_strategies[i]->name,
1575 common, remoteheads,
1576 head_commit);
1577 if (!option_commit && !ret) {
1578 merge_was_ok = 1;
1579 /*
1580 * This is necessary here just to avoid writing
1581 * the tree, but later we will *not* exit with
1582 * status code 1 because merge_was_ok is set.
1583 */
1584 ret = 1;
1585 }
1586 if (ret) {
1588 /*
1589 * The backend exits with 1 when conflicts are
1590 * left to be resolved, with 2 when it does not
1591 * handle the given merge at all.
1592 */
1593 if (ret == 1) {
1594 int cnt = evaluate_result();
1595 if (best_cnt <= 0 || cnt <= best_cnt) {
1597 best_strategy = use_strategies[i]->name;
1598 best_cnt = cnt;
1599 }
1600 }
1601 if (merge_was_ok)
1602 break;
1603 else
1604 continue;
1605 }
1606 /* Automerge succeeded. */
1608 write_tree_trivial(&result_tree);
1609 automerge_was_ok = 1;
1610 break;
1611 }
1612 /*
1614 * If we have a resulting tree, that means the strategy module
1615 * auto resolved the merge cleanly.
1616 */
1617 if (automerge_was_ok) {
1618 ret = finish_automerge(head_commit, head_subsumed,
1619 common, remoteheads,
1620 &result_tree, wt_strategy);
1621 goto done;
1622 }
1623 /*
1625 * Pick the result from the best strategy and have the user fix
1626 * it up.
1627 */
1628 if (!best_strategy) {
1629 restore_state(&head_commit->object.oid, &stash);
1630 if (use_strategies_nr > 1)
1631 fprintf(stderr,
1632 _("No merge strategy handled the merge.\n"));
1633 else
1634 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1635 use_strategies[0]->name);
1636 ret = 2;
1637 goto done;
1638 } else if (best_strategy == wt_strategy)
1639 ; /* We already have its result in the working tree. */
1640 else {
1641 printf(_("Rewinding the tree to pristine...\n"));
1642 restore_state(&head_commit->object.oid, &stash);
1643 printf(_("Using the %s to prepare resolving by hand.\n"),
1644 best_strategy);
1645 try_merge_strategy(best_strategy, common, remoteheads,
1646 head_commit);
1647 }
1648 if (squash)
1650 finish(head_commit, remoteheads, NULL, NULL);
1651 else
1652 write_merge_state(remoteheads);
1653 if (merge_was_ok)
1655 fprintf(stderr, _("Automatic merge went well; "
1656 "stopped before committing as requested\n"));
1657 else
1658 ret = suggest_conflicts();
1659done:
1661 free(branch_to_free);
1662 return ret;
1663}