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 enum parse_opt_result option_read_message(struct parse_opt_ctx_t *ctx,
116 const struct option *opt,
117 const char *arg_not_used,
118 int unset)
119{
120 struct strbuf *buf = opt->value;
121 const char *arg;
122 BUG_ON_OPT_ARG(arg_not_used);
124 if (unset)
125 BUG("-F cannot be negated");
126 if (ctx->opt) {
128 arg = ctx->opt;
129 ctx->opt = NULL;
130 } else if (ctx->argc > 1) {
131 ctx->argc--;
132 arg = *++ctx->argv;
133 } else
134 return error(_("option `%s' requires a value"), opt->long_name);
135 if (buf->len)
137 strbuf_addch(buf, '\n');
138 if (ctx->prefix && !is_absolute_path(arg))
139 arg = prefix_filename(ctx->prefix, arg);
140 if (strbuf_read_file(buf, arg, 0) < 0)
141 return error(_("could not read file '%s'"), arg);
142 have_message = 1;
143 return 0;
145}
146static struct strategy *get_strategy(const char *name)
148{
149 int i;
150 struct strategy *ret;
151 static struct cmdnames main_cmds, other_cmds;
152 static int loaded;
153 if (!name)
155 return NULL;
156 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
158 if (!strcmp(name, all_strategy[i].name))
159 return &all_strategy[i];
160 if (!loaded) {
162 struct cmdnames not_strategies;
163 loaded = 1;
164 memset(¬_strategies, 0, sizeof(struct cmdnames));
166 load_command_list("git-merge-", &main_cmds, &other_cmds);
167 for (i = 0; i < main_cmds.cnt; i++) {
168 int j, found = 0;
169 struct cmdname *ent = main_cmds.names[i];
170 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
171 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
172 && !all_strategy[j].name[ent->len])
173 found = 1;
174 if (!found)
175 add_cmdname(¬_strategies, ent->name, ent->len);
176 }
177 exclude_cmds(&main_cmds, ¬_strategies);
178 }
179 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
180 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
181 fprintf(stderr, _("Available strategies are:"));
182 for (i = 0; i < main_cmds.cnt; i++)
183 fprintf(stderr, " %s", main_cmds.names[i]->name);
184 fprintf(stderr, ".\n");
185 if (other_cmds.cnt) {
186 fprintf(stderr, _("Available custom strategies are:"));
187 for (i = 0; i < other_cmds.cnt; i++)
188 fprintf(stderr, " %s", other_cmds.names[i]->name);
189 fprintf(stderr, ".\n");
190 }
191 exit(1);
192 }
193 ret = xcalloc(1, sizeof(struct strategy));
195 ret->name = xstrdup(name);
196 ret->attr = NO_TRIVIAL;
197 return ret;
198}
199static void append_strategy(struct strategy *s)
201{
202 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
203 use_strategies[use_strategies_nr++] = s;
204}
205static int option_parse_strategy(const struct option *opt,
207 const char *name, int unset)
208{
209 if (unset)
210 return 0;
211 append_strategy(get_strategy(name));
213 return 0;
214}
215static int option_parse_x(const struct option *opt,
217 const char *arg, int unset)
218{
219 if (unset)
220 return 0;
221 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
223 xopts[xopts_nr++] = xstrdup(arg);
224 return 0;
225}
226static int option_parse_n(const struct option *opt,
228 const char *arg, int unset)
229{
230 BUG_ON_OPT_ARG(arg);
231 show_diffstat = unset;
232 return 0;
233}
234static struct option builtin_merge_options[] = {
236 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
237 N_("do not show a diffstat at the end of the merge"),
238 PARSE_OPT_NOARG, option_parse_n },
239 OPT_BOOL(0, "stat", &show_diffstat,
240 N_("show a diffstat at the end of the merge")),
241 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
242 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
243 N_("add (at most <n>) entries from shortlog to merge commit message"),
244 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
245 OPT_BOOL(0, "squash", &squash,
246 N_("create a single commit instead of doing a merge")),
247 OPT_BOOL(0, "commit", &option_commit,
248 N_("perform a commit if the merge succeeds (default)")),
249 OPT_BOOL('e', "edit", &option_edit,
250 N_("edit message before committing")),
251 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
252 OPT_SET_INT_F(0, "ff-only", &fast_forward,
253 N_("abort if fast-forward is not possible"),
254 FF_ONLY, PARSE_OPT_NONEG),
255 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
256 OPT_BOOL(0, "verify-signatures", &verify_signatures,
257 N_("verify that the named commit has a valid GPG signature")),
258 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
259 N_("merge strategy to use"), option_parse_strategy),
260 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
261 N_("option for selected merge strategy"), option_parse_x),
262 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
263 N_("merge commit message (for a non-fast-forward merge)"),
264 option_parse_message),
265 { OPTION_LOWLEVEL_CALLBACK, 'F', "file", &merge_msg, N_("path"),
266 N_("read message from file"), PARSE_OPT_NONEG,
267 NULL, 0, option_read_message },
268 OPT__VERBOSITY(&verbosity),
269 OPT_BOOL(0, "abort", &abort_current_merge,
270 N_("abort the current in-progress merge")),
271 OPT_BOOL(0, "continue", &continue_current_merge,
272 N_("continue the current in-progress merge")),
273 OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
274 N_("allow merging unrelated histories")),
275 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
276 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
277 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
278 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
279 OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
280 OPT_BOOL(0, "verify", &verify_msg, N_("verify commit-msg hook")),
281 OPT_END()
282};
283/* Cleans up metadata that is uninteresting after a succeeded merge. */
285static void drop_save(void)
286{
287 unlink(git_path_merge_head(the_repository));
288 unlink(git_path_merge_msg(the_repository));
289 unlink(git_path_merge_mode(the_repository));
290}
291static int save_state(struct object_id *stash)
293{
294 int len;
295 struct child_process cp = CHILD_PROCESS_INIT;
296 struct strbuf buffer = STRBUF_INIT;
297 const char *argv[] = {"stash", "create", NULL};
298 int rc = -1;
299 cp.argv = argv;
301 cp.out = -1;
302 cp.git_cmd = 1;
303 if (start_command(&cp))
305 die(_("could not run stash."));
306 len = strbuf_read(&buffer, cp.out, 1024);
307 close(cp.out);
308 if (finish_command(&cp) || len < 0)
310 die(_("stash failed"));
311 else if (!len) /* no changes */
312 goto out;
313 strbuf_setlen(&buffer, buffer.len-1);
314 if (get_oid(buffer.buf, stash))
315 die(_("not a valid object: %s"), buffer.buf);
316 rc = 0;
317out:
318 strbuf_release(&buffer);
319 return rc;
320}
321static void read_empty(const struct object_id *oid, int verbose)
323{
324 int i = 0;
325 const char *args[7];
326 args[i++] = "read-tree";
328 if (verbose)
329 args[i++] = "-v";
330 args[i++] = "-m";
331 args[i++] = "-u";
332 args[i++] = empty_tree_oid_hex();
333 args[i++] = oid_to_hex(oid);
334 args[i] = NULL;
335 if (run_command_v_opt(args, RUN_GIT_CMD))
337 die(_("read-tree failed"));
338}
339static void reset_hard(const struct object_id *oid, int verbose)
341{
342 int i = 0;
343 const char *args[6];
344 args[i++] = "read-tree";
346 if (verbose)
347 args[i++] = "-v";
348 args[i++] = "--reset";
349 args[i++] = "-u";
350 args[i++] = oid_to_hex(oid);
351 args[i] = NULL;
352 if (run_command_v_opt(args, RUN_GIT_CMD))
354 die(_("read-tree failed"));
355}
356static void restore_state(const struct object_id *head,
358 const struct object_id *stash)
359{
360 struct strbuf sb = STRBUF_INIT;
361 const char *args[] = { "stash", "apply", NULL, NULL };
362 if (is_null_oid(stash))
364 return;
365 reset_hard(head, 1);
367 args[2] = oid_to_hex(stash);
369 /*
371 * It is OK to ignore error here, for example when there was
372 * nothing to restore.
373 */
374 run_command_v_opt(args, RUN_GIT_CMD);
375 strbuf_release(&sb);
377 refresh_cache(REFRESH_QUIET);
378}
379/* This is called when no merge was necessary. */
381static void finish_up_to_date(const char *msg)
382{
383 if (verbosity >= 0)
384 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
385 drop_save();
386}
387static void squash_message(struct commit *commit, struct commit_list *remoteheads)
389{
390 struct rev_info rev;
391 struct strbuf out = STRBUF_INIT;
392 struct commit_list *j;
393 struct pretty_print_context ctx = {0};
394 printf(_("Squash commit -- not updating HEAD\n"));
396 repo_init_revisions(the_repository, &rev, NULL);
398 rev.ignore_merges = 1;
399 rev.commit_format = CMIT_FMT_MEDIUM;
400 commit->object.flags |= UNINTERESTING;
402 add_pending_object(&rev, &commit->object, NULL);
403 for (j = remoteheads; j; j = j->next)
405 add_pending_object(&rev, &j->item->object, NULL);
406 setup_revisions(0, NULL, &rev, NULL);
408 if (prepare_revision_walk(&rev))
409 die(_("revision walk setup failed"));
410 ctx.abbrev = rev.abbrev;
412 ctx.date_mode = rev.date_mode;
413 ctx.fmt = rev.commit_format;
414 strbuf_addstr(&out, "Squashed commit of the following:\n");
416 while ((commit = get_revision(&rev)) != NULL) {
417 strbuf_addch(&out, '\n');
418 strbuf_addf(&out, "commit %s\n",
419 oid_to_hex(&commit->object.oid));
420 pretty_print_commit(&ctx, commit, &out);
421 }
422 write_file_buf(git_path_squash_msg(the_repository), out.buf, out.len);
423 strbuf_release(&out);
424}
425static void finish(struct commit *head_commit,
427 struct commit_list *remoteheads,
428 const struct object_id *new_head, const char *msg)
429{
430 struct strbuf reflog_message = STRBUF_INIT;
431 const struct object_id *head = &head_commit->object.oid;
432 if (!msg)
434 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
435 else {
436 if (verbosity >= 0)
437 printf("%s\n", msg);
438 strbuf_addf(&reflog_message, "%s: %s",
439 getenv("GIT_REFLOG_ACTION"), msg);
440 }
441 if (squash) {
442 squash_message(head_commit, remoteheads);
443 } else {
444 if (verbosity >= 0 && !merge_msg.len)
445 printf(_("No merge message -- not updating HEAD\n"));
446 else {
447 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
448 update_ref(reflog_message.buf, "HEAD", new_head, head,
449 0, UPDATE_REFS_DIE_ON_ERR);
450 /*
451 * We ignore errors in 'gc --auto', since the
452 * user should see them.
453 */
454 close_all_packs(the_repository->objects);
455 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
456 }
457 }
458 if (new_head && show_diffstat) {
459 struct diff_options opts;
460 repo_diff_setup(the_repository, &opts);
461 opts.stat_width = -1; /* use full terminal width */
462 opts.stat_graph_width = -1; /* respect statGraphWidth config */
463 opts.output_format |=
464 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
465 opts.detect_rename = DIFF_DETECT_RENAME;
466 diff_setup_done(&opts);
467 diff_tree_oid(head, new_head, "", &opts);
468 diffcore_std(&opts);
469 diff_flush(&opts);
470 }
471 /* Run a post-merge hook */
473 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
474 strbuf_release(&reflog_message);
476}
477/* Get the name for the merge commit's message. */
479static void merge_name(const char *remote, struct strbuf *msg)
480{
481 struct commit *remote_head;
482 struct object_id branch_head;
483 struct strbuf buf = STRBUF_INIT;
484 struct strbuf bname = STRBUF_INIT;
485 struct merge_remote_desc *desc;
486 const char *ptr;
487 char *found_ref;
488 int len, early;
489 strbuf_branchname(&bname, remote, 0);
491 remote = bname.buf;
492 oidclr(&branch_head);
494 remote_head = get_merge_parent(remote);
495 if (!remote_head)
496 die(_("'%s' does not point to a commit"), remote);
497 if (dwim_ref(remote, strlen(remote), &branch_head, &found_ref) > 0) {
499 if (starts_with(found_ref, "refs/heads/")) {
500 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
501 oid_to_hex(&branch_head), remote);
502 goto cleanup;
503 }
504 if (starts_with(found_ref, "refs/tags/")) {
505 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
506 oid_to_hex(&branch_head), remote);
507 goto cleanup;
508 }
509 if (starts_with(found_ref, "refs/remotes/")) {
510 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
511 oid_to_hex(&branch_head), remote);
512 goto cleanup;
513 }
514 }
515 /* See if remote matches <name>^^^.. or <name>~<number> */
517 for (len = 0, ptr = remote + strlen(remote);
518 remote < ptr && ptr[-1] == '^';
519 ptr--)
520 len++;
521 if (len)
522 early = 1;
523 else {
524 early = 0;
525 ptr = strrchr(remote, '~');
526 if (ptr) {
527 int seen_nonzero = 0;
528 len++; /* count ~ */
530 while (*++ptr && isdigit(*ptr)) {
531 seen_nonzero |= (*ptr != '0');
532 len++;
533 }
534 if (*ptr)
535 len = 0; /* not ...~<number> */
536 else if (seen_nonzero)
537 early = 1;
538 else if (len == 1)
539 early = 1; /* "name~" is "name~1"! */
540 }
541 }
542 if (len) {
543 struct strbuf truname = STRBUF_INIT;
544 strbuf_addf(&truname, "refs/heads/%s", remote);
545 strbuf_setlen(&truname, truname.len - len);
546 if (ref_exists(truname.buf)) {
547 strbuf_addf(msg,
548 "%s\t\tbranch '%s'%s of .\n",
549 oid_to_hex(&remote_head->object.oid),
550 truname.buf + 11,
551 (early ? " (early part)" : ""));
552 strbuf_release(&truname);
553 goto cleanup;
554 }
555 strbuf_release(&truname);
556 }
557 desc = merge_remote_util(remote_head);
559 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
560 strbuf_addf(msg, "%s\t\t%s '%s'\n",
561 oid_to_hex(&desc->obj->oid),
562 type_name(desc->obj->type),
563 remote);
564 goto cleanup;
565 }
566 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
568 oid_to_hex(&remote_head->object.oid), remote);
569cleanup:
570 strbuf_release(&buf);
571 strbuf_release(&bname);
572}
573static void parse_branch_merge_options(char *bmo)
575{
576 const char **argv;
577 int argc;
578 if (!bmo)
580 return;
581 argc = split_cmdline(bmo, &argv);
582 if (argc < 0)
583 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
584 _(split_cmdline_strerror(argc)));
585 REALLOC_ARRAY(argv, argc + 2);
586 MOVE_ARRAY(argv + 1, argv, argc + 1);
587 argc++;
588 argv[0] = "branch.*.mergeoptions";
589 parse_options(argc, argv, NULL, builtin_merge_options,
590 builtin_merge_usage, 0);
591 free(argv);
592}
593static int git_merge_config(const char *k, const char *v, void *cb)
595{
596 int status;
597 if (branch && starts_with(k, "branch.") &&
599 starts_with(k + 7, branch) &&
600 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
601 free(branch_mergeoptions);
602 branch_mergeoptions = xstrdup(v);
603 return 0;
604 }
605 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
607 show_diffstat = git_config_bool(k, v);
608 else if (!strcmp(k, "merge.verifysignatures"))
609 verify_signatures = git_config_bool(k, v);
610 else if (!strcmp(k, "pull.twohead"))
611 return git_config_string(&pull_twohead, k, v);
612 else if (!strcmp(k, "pull.octopus"))
613 return git_config_string(&pull_octopus, k, v);
614 else if (!strcmp(k, "merge.renormalize"))
615 option_renormalize = git_config_bool(k, v);
616 else if (!strcmp(k, "merge.ff")) {
617 int boolval = git_parse_maybe_bool(v);
618 if (0 <= boolval) {
619 fast_forward = boolval ? FF_ALLOW : FF_NO;
620 } else if (v && !strcmp(v, "only")) {
621 fast_forward = FF_ONLY;
622 } /* do not barf on values from future versions of git */
623 return 0;
624 } else if (!strcmp(k, "merge.defaulttoupstream")) {
625 default_to_upstream = git_config_bool(k, v);
626 return 0;
627 } else if (!strcmp(k, "commit.gpgsign")) {
628 sign_commit = git_config_bool(k, v) ? "" : NULL;
629 return 0;
630 }
631 status = fmt_merge_msg_config(k, v, cb);
633 if (status)
634 return status;
635 status = git_gpg_config(k, v, NULL);
636 if (status)
637 return status;
638 return git_diff_ui_config(k, v, cb);
639}
640static int read_tree_trivial(struct object_id *common, struct object_id *head,
642 struct object_id *one)
643{
644 int i, nr_trees = 0;
645 struct tree *trees[MAX_UNPACK_TREES];
646 struct tree_desc t[MAX_UNPACK_TREES];
647 struct unpack_trees_options opts;
648 memset(&opts, 0, sizeof(opts));
650 opts.head_idx = 2;
651 opts.src_index = &the_index;
652 opts.dst_index = &the_index;
653 opts.update = 1;
654 opts.verbose_update = 1;
655 opts.trivial_merges_only = 1;
656 opts.merge = 1;
657 trees[nr_trees] = parse_tree_indirect(common);
658 if (!trees[nr_trees++])
659 return -1;
660 trees[nr_trees] = parse_tree_indirect(head);
661 if (!trees[nr_trees++])
662 return -1;
663 trees[nr_trees] = parse_tree_indirect(one);
664 if (!trees[nr_trees++])
665 return -1;
666 opts.fn = threeway_merge;
667 cache_tree_free(&active_cache_tree);
668 for (i = 0; i < nr_trees; i++) {
669 parse_tree(trees[i]);
670 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
671 }
672 if (unpack_trees(nr_trees, t, &opts))
673 return -1;
674 return 0;
675}
676static void write_tree_trivial(struct object_id *oid)
678{
679 if (write_cache_as_tree(oid, 0, NULL))
680 die(_("git write-tree failed to write a tree"));
681}
682static int try_merge_strategy(const char *strategy, struct commit_list *common,
684 struct commit_list *remoteheads,
685 struct commit *head)
686{
687 struct lock_file lock = LOCK_INIT;
688 const char *head_arg = "HEAD";
689 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
691 refresh_cache(REFRESH_QUIET);
692 if (write_locked_index(&the_index, &lock,
693 COMMIT_LOCK | SKIP_IF_UNCHANGED))
694 return error(_("Unable to write index."));
695 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
697 int clean, x;
698 struct commit *result;
699 struct commit_list *reversed = NULL;
700 struct merge_options o;
701 struct commit_list *j;
702 if (remoteheads->next) {
704 error(_("Not handling anything other than two heads merge."));
705 return 2;
706 }
707 init_merge_options(&o);
709 if (!strcmp(strategy, "subtree"))
710 o.subtree_shift = "";
711 o.renormalize = option_renormalize;
713 o.show_rename_progress =
714 show_progress == -1 ? isatty(2) : show_progress;
715 for (x = 0; x < xopts_nr; x++)
717 if (parse_merge_opt(&o, xopts[x]))
718 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
719 o.branch1 = head_arg;
721 o.branch2 = merge_remote_util(remoteheads->item)->name;
722 for (j = common; j; j = j->next)
724 commit_list_insert(j->item, &reversed);
725 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
727 clean = merge_recursive(&o, head,
728 remoteheads->item, reversed, &result);
729 if (clean < 0)
730 exit(128);
731 if (write_locked_index(&the_index, &lock,
732 COMMIT_LOCK | SKIP_IF_UNCHANGED))
733 die(_("unable to write %s"), get_index_file());
734 return clean ? 0 : 1;
735 } else {
736 return try_merge_command(the_repository,
737 strategy, xopts_nr, xopts,
738 common, head_arg, remoteheads);
739 }
740}
741static void count_diff_files(struct diff_queue_struct *q,
743 struct diff_options *opt, void *data)
744{
745 int *count = data;
746 (*count) += q->nr;
748}
749static int count_unmerged_entries(void)
751{
752 int i, ret = 0;
753 for (i = 0; i < active_nr; i++)
755 if (ce_stage(active_cache[i]))
756 ret++;
757 return ret;
759}
760static void add_strategies(const char *string, unsigned attr)
762{
763 int i;
764 if (string) {
766 struct string_list list = STRING_LIST_INIT_DUP;
767 struct string_list_item *item;
768 string_list_split(&list, string, ' ', -1);
769 for_each_string_list_item(item, &list)
770 append_strategy(get_strategy(item->string));
771 string_list_clear(&list, 0);
772 return;
773 }
774 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
775 if (all_strategy[i].attr & attr)
776 append_strategy(&all_strategy[i]);
777}
779static void read_merge_msg(struct strbuf *msg)
781{
782 const char *filename = git_path_merge_msg(the_repository);
783 strbuf_reset(msg);
784 if (strbuf_read_file(msg, filename, 0) < 0)
785 die_errno(_("Could not read from '%s'"), filename);
786}
787static void write_merge_state(struct commit_list *);
789static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
790{
791 if (err_msg)
792 error("%s", err_msg);
793 fprintf(stderr,
794 _("Not committing merge; use 'git commit' to complete the merge.\n"));
795 write_merge_state(remoteheads);
796 exit(1);
797}
798static const char merge_editor_comment[] =
800N_("Please enter a commit message to explain why this merge is necessary,\n"
801 "especially if it merges an updated upstream into a topic branch.\n"
802 "\n"
803 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
804 "the commit.\n");
805static void write_merge_heads(struct commit_list *);
807static void prepare_to_commit(struct commit_list *remoteheads)
808{
809 struct strbuf msg = STRBUF_INIT;
810 strbuf_addbuf(&msg, &merge_msg);
811 strbuf_addch(&msg, '\n');
812 if (squash)
813 BUG("the control must not reach here under --squash");
814 if (0 < option_edit)
815 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
816 if (signoff)
817 append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
818 write_merge_heads(remoteheads);
819 write_file_buf(git_path_merge_msg(the_repository), msg.buf, msg.len);
820 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
821 git_path_merge_msg(the_repository), "merge", NULL))
822 abort_commit(remoteheads, NULL);
823 if (0 < option_edit) {
824 if (launch_editor(git_path_merge_msg(the_repository), NULL, NULL))
825 abort_commit(remoteheads, NULL);
826 }
827 if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
829 "commit-msg",
830 git_path_merge_msg(the_repository), NULL))
831 abort_commit(remoteheads, NULL);
832 read_merge_msg(&msg);
834 strbuf_stripspace(&msg, 0 < option_edit);
835 if (!msg.len)
836 abort_commit(remoteheads, _("Empty commit message."));
837 strbuf_release(&merge_msg);
838 strbuf_addbuf(&merge_msg, &msg);
839 strbuf_release(&msg);
840}
841static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
843{
844 struct object_id result_tree, result_commit;
845 struct commit_list *parents, **pptr = &parents;
846 struct lock_file lock = LOCK_INIT;
847 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
849 refresh_cache(REFRESH_QUIET);
850 if (write_locked_index(&the_index, &lock,
851 COMMIT_LOCK | SKIP_IF_UNCHANGED))
852 return error(_("Unable to write index."));
853 write_tree_trivial(&result_tree);
855 printf(_("Wonderful.\n"));
856 pptr = commit_list_append(head, pptr);
857 pptr = commit_list_append(remoteheads->item, pptr);
858 prepare_to_commit(remoteheads);
859 if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
860 &result_commit, NULL, sign_commit))
861 die(_("failed to write commit object"));
862 finish(head, remoteheads, &result_commit, "In-index merge");
863 drop_save();
864 return 0;
865}
866static int finish_automerge(struct commit *head,
868 int head_subsumed,
869 struct commit_list *common,
870 struct commit_list *remoteheads,
871 struct object_id *result_tree,
872 const char *wt_strategy)
873{
874 struct commit_list *parents = NULL;
875 struct strbuf buf = STRBUF_INIT;
876 struct object_id result_commit;
877 free_commit_list(common);
879 parents = remoteheads;
880 if (!head_subsumed || fast_forward == FF_NO)
881 commit_list_insert(head, &parents);
882 strbuf_addch(&merge_msg, '\n');
883 prepare_to_commit(remoteheads);
884 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
885 &result_commit, NULL, sign_commit))
886 die(_("failed to write commit object"));
887 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
888 finish(head, remoteheads, &result_commit, buf.buf);
889 strbuf_release(&buf);
890 drop_save();
891 return 0;
892}
893static int suggest_conflicts(void)
895{
896 const char *filename;
897 FILE *fp;
898 struct strbuf msgbuf = STRBUF_INIT;
899 filename = git_path_merge_msg(the_repository);
901 fp = xfopen(filename, "a");
902 append_conflicts_hint(&the_index, &msgbuf);
904 fputs(msgbuf.buf, fp);
905 strbuf_release(&msgbuf);
906 fclose(fp);
907 repo_rerere(the_repository, allow_rerere_auto);
908 printf(_("Automatic merge failed; "
909 "fix conflicts and then commit the result.\n"));
910 return 1;
911}
912static int evaluate_result(void)
914{
915 int cnt = 0;
916 struct rev_info rev;
917 /* Check how many files differ. */
919 repo_init_revisions(the_repository, &rev, "");
920 setup_revisions(0, NULL, &rev, NULL);
921 rev.diffopt.output_format |=
922 DIFF_FORMAT_CALLBACK;
923 rev.diffopt.format_callback = count_diff_files;
924 rev.diffopt.format_callback_data = &cnt;
925 run_diff_files(&rev, 0);
926 /*
928 * Check how many unmerged entries are
929 * there.
930 */
931 cnt += count_unmerged_entries();
932 return cnt;
934}
935/*
937 * Pretend as if the user told us to merge with the remote-tracking
938 * branch we have for the upstream of the current branch
939 */
940static int setup_with_upstream(const char ***argv)
941{
942 struct branch *branch = branch_get(NULL);
943 int i;
944 const char **args;
945 if (!branch)
947 die(_("No current branch."));
948 if (!branch->remote_name)
949 die(_("No remote for the current branch."));
950 if (!branch->merge_nr)
951 die(_("No default upstream defined for the current branch."));
952 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
954 for (i = 0; i < branch->merge_nr; i++) {
955 if (!branch->merge[i]->dst)
956 die(_("No remote-tracking branch for %s from %s"),
957 branch->merge[i]->src, branch->remote_name);
958 args[i] = branch->merge[i]->dst;
959 }
960 args[i] = NULL;
961 *argv = args;
962 return i;
963}
964static void write_merge_heads(struct commit_list *remoteheads)
966{
967 struct commit_list *j;
968 struct strbuf buf = STRBUF_INIT;
969 for (j = remoteheads; j; j = j->next) {
971 struct object_id *oid;
972 struct commit *c = j->item;
973 struct merge_remote_desc *desc;
974 desc = merge_remote_util(c);
976 if (desc && desc->obj) {
977 oid = &desc->obj->oid;
978 } else {
979 oid = &c->object.oid;
980 }
981 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
982 }
983 write_file_buf(git_path_merge_head(the_repository), buf.buf, buf.len);
984 strbuf_reset(&buf);
986 if (fast_forward == FF_NO)
987 strbuf_addstr(&buf, "no-ff");
988 write_file_buf(git_path_merge_mode(the_repository), buf.buf, buf.len);
989 strbuf_release(&buf);
990}
991static void write_merge_state(struct commit_list *remoteheads)
993{
994 write_merge_heads(remoteheads);
995 strbuf_addch(&merge_msg, '\n');
996 write_file_buf(git_path_merge_msg(the_repository), merge_msg.buf,
997 merge_msg.len);
998}
999static int default_edit_option(void)
1001{
1002 static const char name[] = "GIT_MERGE_AUTOEDIT";
1003 const char *e = getenv(name);
1004 struct stat st_stdin, st_stdout;
1005 if (have_message)
1007 /* an explicit -m msg without --[no-]edit */
1008 return 0;
1009 if (e) {
1011 int v = git_parse_maybe_bool(e);
1012 if (v < 0)
1013 die(_("Bad value '%s' in environment '%s'"), e, name);
1014 return v;
1015 }
1016 /* Use editor if stdin and stdout are the same and is a tty */
1018 return (!fstat(0, &st_stdin) &&
1019 !fstat(1, &st_stdout) &&
1020 isatty(0) && isatty(1) &&
1021 st_stdin.st_dev == st_stdout.st_dev &&
1022 st_stdin.st_ino == st_stdout.st_ino &&
1023 st_stdin.st_mode == st_stdout.st_mode);
1024}
1025static struct commit_list *reduce_parents(struct commit *head_commit,
1027 int *head_subsumed,
1028 struct commit_list *remoteheads)
1029{
1030 struct commit_list *parents, **remotes;
1031 /*
1033 * Is the current HEAD reachable from another commit being
1034 * merged? If so we do not want to record it as a parent of
1035 * the resulting merge, unless --no-ff is given. We will flip
1036 * this variable to 0 when we find HEAD among the independent
1037 * tips being merged.
1038 */
1039 *head_subsumed = 1;
1040 /* Find what parents to record by checking independent ones. */
1042 parents = reduce_heads(remoteheads);
1043 free_commit_list(remoteheads);
1044 remoteheads = NULL;
1046 remotes = &remoteheads;
1047 while (parents) {
1048 struct commit *commit = pop_commit(&parents);
1049 if (commit == head_commit)
1050 *head_subsumed = 0;
1051 else
1052 remotes = &commit_list_insert(commit, remotes)->next;
1053 }
1054 return remoteheads;
1055}
1056static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1058{
1059 struct fmt_merge_msg_opts opts;
1060 memset(&opts, 0, sizeof(opts));
1062 opts.add_title = !have_message;
1063 opts.shortlog_len = shortlog_len;
1064 opts.credit_people = (0 < option_edit);
1065 fmt_merge_msg(merge_names, merge_msg, &opts);
1067 if (merge_msg->len)
1068 strbuf_setlen(merge_msg, merge_msg->len - 1);
1069}
1070static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1072{
1073 const char *filename;
1074 int fd, pos, npos;
1075 struct strbuf fetch_head_file = STRBUF_INIT;
1076 const unsigned hexsz = the_hash_algo->hexsz;
1077 if (!merge_names)
1079 merge_names = &fetch_head_file;
1080 filename = git_path_fetch_head(the_repository);
1082 fd = open(filename, O_RDONLY);
1083 if (fd < 0)
1084 die_errno(_("could not open '%s' for reading"), filename);
1085 if (strbuf_read(merge_names, fd, 0) < 0)
1087 die_errno(_("could not read '%s'"), filename);
1088 if (close(fd) < 0)
1089 die_errno(_("could not close '%s'"), filename);
1090 for (pos = 0; pos < merge_names->len; pos = npos) {
1092 struct object_id oid;
1093 char *ptr;
1094 struct commit *commit;
1095 ptr = strchr(merge_names->buf + pos, '\n');
1097 if (ptr)
1098 npos = ptr - merge_names->buf + 1;
1099 else
1100 npos = merge_names->len;
1101 if (npos - pos < hexsz + 2 ||
1103 get_oid_hex(merge_names->buf + pos, &oid))
1104 commit = NULL; /* bad */
1105 else if (memcmp(merge_names->buf + pos + hexsz, "\t\t", 2))
1106 continue; /* not-for-merge */
1107 else {
1108 char saved = merge_names->buf[pos + hexsz];
1109 merge_names->buf[pos + hexsz] = '\0';
1110 commit = get_merge_parent(merge_names->buf + pos);
1111 merge_names->buf[pos + hexsz] = saved;
1112 }
1113 if (!commit) {
1114 if (ptr)
1115 *ptr = '\0';
1116 die(_("not something we can merge in %s: %s"),
1117 filename, merge_names->buf + pos);
1118 }
1119 remotes = &commit_list_insert(commit, remotes)->next;
1120 }
1121 if (merge_names == &fetch_head_file)
1123 strbuf_release(&fetch_head_file);
1124}
1125static struct commit_list *collect_parents(struct commit *head_commit,
1127 int *head_subsumed,
1128 int argc, const char **argv,
1129 struct strbuf *merge_msg)
1130{
1131 int i;
1132 struct commit_list *remoteheads = NULL;
1133 struct commit_list **remotes = &remoteheads;
1134 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1135 if (merge_msg && (!have_message || shortlog_len))
1137 autogen = &merge_names;
1138 if (head_commit)
1140 remotes = &commit_list_insert(head_commit, remotes)->next;
1141 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1143 handle_fetch_head(remotes, autogen);
1144 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1145 } else {
1146 for (i = 0; i < argc; i++) {
1147 struct commit *commit = get_merge_parent(argv[i]);
1148 if (!commit)
1149 help_unknown_ref(argv[i], "merge",
1150 _("not something we can merge"));
1151 remotes = &commit_list_insert(commit, remotes)->next;
1152 }
1153 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1154 if (autogen) {
1155 struct commit_list *p;
1156 for (p = remoteheads; p; p = p->next)
1157 merge_name(merge_remote_util(p->item)->name, autogen);
1158 }
1159 }
1160 if (autogen) {
1162 prepare_merge_message(autogen, merge_msg);
1163 strbuf_release(autogen);
1164 }
1165 return remoteheads;
1167}
1168static int merging_a_throwaway_tag(struct commit *commit)
1170{
1171 char *tag_ref;
1172 struct object_id oid;
1173 int is_throwaway_tag = 0;
1174 /* Are we merging a tag? */
1176 if (!merge_remote_util(commit) ||
1177 !merge_remote_util(commit)->obj ||
1178 merge_remote_util(commit)->obj->type != OBJ_TAG)
1179 return is_throwaway_tag;
1180 /*
1182 * Now we know we are merging a tag object. Are we downstream
1183 * and following the tags from upstream? If so, we must have
1184 * the tag object pointed at by "refs/tags/$T" where $T is the
1185 * tagname recorded in the tag object. We want to allow such
1186 * a "just to catch up" merge to fast-forward.
1187 *
1188 * Otherwise, we are playing an integrator's role, making a
1189 * merge with a throw-away tag from a contributor with
1190 * something like "git pull $contributor $signed_tag".
1191 * We want to forbid such a merge from fast-forwarding
1192 * by default; otherwise we would not keep the signature
1193 * anywhere.
1194 */
1195 tag_ref = xstrfmt("refs/tags/%s",
1196 ((struct tag *)merge_remote_util(commit)->obj)->tag);
1197 if (!read_ref(tag_ref, &oid) &&
1198 oideq(&oid, &merge_remote_util(commit)->obj->oid))
1199 is_throwaway_tag = 0;
1200 else
1201 is_throwaway_tag = 1;
1202 free(tag_ref);
1203 return is_throwaway_tag;
1204}
1205int cmd_merge(int argc, const char **argv, const char *prefix)
1207{
1208 struct object_id result_tree, stash, head_oid;
1209 struct commit *head_commit;
1210 struct strbuf buf = STRBUF_INIT;
1211 int i, ret = 0, head_subsumed;
1212 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1213 struct commit_list *common = NULL;
1214 const char *best_strategy = NULL, *wt_strategy = NULL;
1215 struct commit_list *remoteheads, *p;
1216 void *branch_to_free;
1217 int orig_argc = argc;
1218 if (argc == 2 && !strcmp(argv[1], "-h"))
1220 usage_with_options(builtin_merge_usage, builtin_merge_options);
1221 /*
1223 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1224 * current branch.
1225 */
1226 branch = branch_to_free = resolve_refdup("HEAD", 0, &head_oid, NULL);
1227 if (branch)
1228 skip_prefix(branch, "refs/heads/", &branch);
1229 init_diff_ui_defaults();
1231 git_config(git_merge_config, NULL);
1232 if (!branch || is_null_oid(&head_oid))
1234 head_commit = NULL;
1235 else
1236 head_commit = lookup_commit_or_die(&head_oid, "HEAD");
1237 if (branch_mergeoptions)
1239 parse_branch_merge_options(branch_mergeoptions);
1240 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1241 builtin_merge_usage, 0);
1242 if (shortlog_len < 0)
1243 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1244 if (verbosity < 0 && show_progress == -1)
1246 show_progress = 0;
1247 if (abort_current_merge) {
1249 int nargc = 2;
1250 const char *nargv[] = {"reset", "--merge", NULL};
1251 if (orig_argc != 2)
1253 usage_msg_opt(_("--abort expects no arguments"),
1254 builtin_merge_usage, builtin_merge_options);
1255 if (!file_exists(git_path_merge_head(the_repository)))
1257 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1258 /* Invoke 'git reset --merge' */
1260 ret = cmd_reset(nargc, nargv, prefix);
1261 goto done;
1262 }
1263 if (continue_current_merge) {
1265 int nargc = 1;
1266 const char *nargv[] = {"commit", NULL};
1267 if (orig_argc != 2)
1269 usage_msg_opt(_("--continue expects no arguments"),
1270 builtin_merge_usage, builtin_merge_options);
1271 if (!file_exists(git_path_merge_head(the_repository)))
1273 die(_("There is no merge in progress (MERGE_HEAD missing)."));
1274 /* Invoke 'git commit' */
1276 ret = cmd_commit(nargc, nargv, prefix);
1277 goto done;
1278 }
1279 if (read_cache_unmerged())
1281 die_resolve_conflict("merge");
1282 if (file_exists(git_path_merge_head(the_repository))) {
1284 /*
1285 * There is no unmerged entry, don't advise 'git
1286 * add/rm <file>', just 'git commit'.
1287 */
1288 if (advice_resolve_conflict)
1289 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1290 "Please, commit your changes before you merge."));
1291 else
1292 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1293 }
1294 if (file_exists(git_path_cherry_pick_head(the_repository))) {
1295 if (advice_resolve_conflict)
1296 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1297 "Please, commit your changes before you merge."));
1298 else
1299 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1300 }
1301 resolve_undo_clear();
1302 if (verbosity < 0)
1304 show_diffstat = 0;
1305 if (squash) {
1307 if (fast_forward == FF_NO)
1308 die(_("You cannot combine --squash with --no-ff."));
1309 option_commit = 0;
1310 }
1311 if (!argc) {
1313 if (default_to_upstream)
1314 argc = setup_with_upstream(&argv);
1315 else
1316 die(_("No commit specified and merge.defaultToUpstream not set."));
1317 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1318 argv[0] = "@{-1}";
1319 }
1320 if (!argc)
1322 usage_with_options(builtin_merge_usage,
1323 builtin_merge_options);
1324 if (!head_commit) {
1326 /*
1327 * If the merged head is a valid one there is no reason
1328 * to forbid "git merge" into a branch yet to be born.
1329 * We do the same for "git pull".
1330 */
1331 struct object_id *remote_head_oid;
1332 if (squash)
1333 die(_("Squash commit into empty head not supported yet"));
1334 if (fast_forward == FF_NO)
1335 die(_("Non-fast-forward commit does not make sense into "
1336 "an empty head"));
1337 remoteheads = collect_parents(head_commit, &head_subsumed,
1338 argc, argv, NULL);
1339 if (!remoteheads)
1340 die(_("%s - not something we can merge"), argv[0]);
1341 if (remoteheads->next)
1342 die(_("Can merge only exactly one commit into empty head"));
1343 if (verify_signatures)
1345 verify_merge_signature(remoteheads->item, verbosity);
1346 remote_head_oid = &remoteheads->item->object.oid;
1348 read_empty(remote_head_oid, 0);
1349 update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
1350 UPDATE_REFS_DIE_ON_ERR);
1351 goto done;
1352 }
1353 /*
1355 * All the rest are the commits being merged; prepare
1356 * the standard merge summary message to be appended
1357 * to the given message.
1358 */
1359 remoteheads = collect_parents(head_commit, &head_subsumed,
1360 argc, argv, &merge_msg);
1361 if (!head_commit || !argc)
1363 usage_with_options(builtin_merge_usage,
1364 builtin_merge_options);
1365 if (verify_signatures) {
1367 for (p = remoteheads; p; p = p->next) {
1368 verify_merge_signature(p->item, verbosity);
1369 }
1370 }
1371 strbuf_addstr(&buf, "merge");
1373 for (p = remoteheads; p; p = p->next)
1374 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1375 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1376 strbuf_reset(&buf);
1377 for (p = remoteheads; p; p = p->next) {
1379 struct commit *commit = p->item;
1380 strbuf_addf(&buf, "GITHEAD_%s",
1381 oid_to_hex(&commit->object.oid));
1382 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1383 strbuf_reset(&buf);
1384 if (fast_forward != FF_ONLY && merging_a_throwaway_tag(commit))
1385 fast_forward = FF_NO;
1386 }
1387 if (option_edit < 0)
1389 option_edit = default_edit_option();
1390 if (!use_strategies) {
1392 if (!remoteheads)
1393 ; /* already up-to-date */
1394 else if (!remoteheads->next)
1395 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1396 else
1397 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1398 }
1399 for (i = 0; i < use_strategies_nr; i++) {
1401 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1402 fast_forward = FF_NO;
1403 if (use_strategies[i]->attr & NO_TRIVIAL)
1404 allow_trivial = 0;
1405 }
1406 if (!remoteheads)
1408 ; /* already up-to-date */
1409 else if (!remoteheads->next)
1410 common = get_merge_bases(head_commit, remoteheads->item);
1411 else {
1412 struct commit_list *list = remoteheads;
1413 commit_list_insert(head_commit, &list);
1414 common = get_octopus_merge_bases(list);
1415 free(list);
1416 }
1417 update_ref("updating ORIG_HEAD", "ORIG_HEAD",
1419 &head_commit->object.oid, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1420 if (remoteheads && !common) {
1422 /* No common ancestors found. */
1423 if (!allow_unrelated_histories)
1424 die(_("refusing to merge unrelated histories"));
1425 /* otherwise, we need a real merge. */
1426 } else if (!remoteheads ||
1427 (!remoteheads->next && !common->next &&
1428 common->item == remoteheads->item)) {
1429 /*
1430 * If head can reach all the merge then we are up to date.
1431 * but first the most common case of merging one remote.
1432 */
1433 finish_up_to_date(_("Already up to date."));
1434 goto done;
1435 } else if (fast_forward != FF_NO && !remoteheads->next &&
1436 !common->next &&
1437 oideq(&common->item->object.oid, &head_commit->object.oid)) {
1438 /* Again the most common case of merging one remote. */
1439 struct strbuf msg = STRBUF_INIT;
1440 struct commit *commit;
1441 if (verbosity >= 0) {
1443 printf(_("Updating %s..%s\n"),
1444 find_unique_abbrev(&head_commit->object.oid,
1445 DEFAULT_ABBREV),
1446 find_unique_abbrev(&remoteheads->item->object.oid,
1447 DEFAULT_ABBREV));
1448 }
1449 strbuf_addstr(&msg, "Fast-forward");
1450 if (have_message)
1451 strbuf_addstr(&msg,
1452 " (no commit created; -m option ignored)");
1453 commit = remoteheads->item;
1454 if (!commit) {
1455 ret = 1;
1456 goto done;
1457 }
1458 if (checkout_fast_forward(the_repository,
1460 &head_commit->object.oid,
1461 &commit->object.oid,
1462 overwrite_ignore)) {
1463 ret = 1;
1464 goto done;
1465 }
1466 finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
1468 drop_save();
1469 goto done;
1470 } else if (!remoteheads->next && common->next)
1471 ;
1472 /*
1473 * We are not doing octopus and not fast-forward. Need
1474 * a real merge.
1475 */
1476 else if (!remoteheads->next && !common->next && option_commit) {
1477 /*
1478 * We are not doing octopus, not fast-forward, and have
1479 * only one common.
1480 */
1481 refresh_cache(REFRESH_QUIET);
1482 if (allow_trivial && fast_forward != FF_ONLY) {
1483 /* See if it is really trivial. */
1484 git_committer_info(IDENT_STRICT);
1485 printf(_("Trying really trivial in-index merge...\n"));
1486 if (!read_tree_trivial(&common->item->object.oid,
1487 &head_commit->object.oid,
1488 &remoteheads->item->object.oid)) {
1489 ret = merge_trivial(head_commit, remoteheads);
1490 goto done;
1491 }
1492 printf(_("Nope.\n"));
1493 }
1494 } else {
1495 /*
1496 * An octopus. If we can reach all the remote we are up
1497 * to date.
1498 */
1499 int up_to_date = 1;
1500 struct commit_list *j;
1501 for (j = remoteheads; j; j = j->next) {
1503 struct commit_list *common_one;
1504 /*
1506 * Here we *have* to calculate the individual
1507 * merge_bases again, otherwise "git merge HEAD^
1508 * HEAD^^" would be missed.
1509 */
1510 common_one = get_merge_bases(head_commit, j->item);
1511 if (!oideq(&common_one->item->object.oid, &j->item->object.oid)) {
1512 up_to_date = 0;
1513 break;
1514 }
1515 }
1516 if (up_to_date) {
1517 finish_up_to_date(_("Already up to date. Yeeah!"));
1518 goto done;
1519 }
1520 }
1521 if (fast_forward == FF_ONLY)
1523 die(_("Not possible to fast-forward, aborting."));
1524 /* We are going to make a new commit. */
1526 git_committer_info(IDENT_STRICT);
1527 /*
1529 * At this point, we need a real merge. No matter what strategy
1530 * we use, it would operate on the index, possibly affecting the
1531 * working tree, and when resolved cleanly, have the desired
1532 * tree in the index -- this means that the index must be in
1533 * sync with the head commit. The strategies are responsible
1534 * to ensure this.
1535 */
1536 if (use_strategies_nr == 1 ||
1537 /*
1538 * Stash away the local changes so that we can try more than one.
1539 */
1540 save_state(&stash))
1541 oidclr(&stash);
1542 for (i = 0; i < use_strategies_nr; i++) {
1544 int ret;
1545 if (i) {
1546 printf(_("Rewinding the tree to pristine...\n"));
1547 restore_state(&head_commit->object.oid, &stash);
1548 }
1549 if (use_strategies_nr != 1)
1550 printf(_("Trying merge strategy %s...\n"),
1551 use_strategies[i]->name);
1552 /*
1553 * Remember which strategy left the state in the working
1554 * tree.
1555 */
1556 wt_strategy = use_strategies[i]->name;
1557 ret = try_merge_strategy(use_strategies[i]->name,
1559 common, remoteheads,
1560 head_commit);
1561 if (!option_commit && !ret) {
1562 merge_was_ok = 1;
1563 /*
1564 * This is necessary here just to avoid writing
1565 * the tree, but later we will *not* exit with
1566 * status code 1 because merge_was_ok is set.
1567 */
1568 ret = 1;
1569 }
1570 if (ret) {
1572 /*
1573 * The backend exits with 1 when conflicts are
1574 * left to be resolved, with 2 when it does not
1575 * handle the given merge at all.
1576 */
1577 if (ret == 1) {
1578 int cnt = evaluate_result();
1579 if (best_cnt <= 0 || cnt <= best_cnt) {
1581 best_strategy = use_strategies[i]->name;
1582 best_cnt = cnt;
1583 }
1584 }
1585 if (merge_was_ok)
1586 break;
1587 else
1588 continue;
1589 }
1590 /* Automerge succeeded. */
1592 write_tree_trivial(&result_tree);
1593 automerge_was_ok = 1;
1594 break;
1595 }
1596 /*
1598 * If we have a resulting tree, that means the strategy module
1599 * auto resolved the merge cleanly.
1600 */
1601 if (automerge_was_ok) {
1602 ret = finish_automerge(head_commit, head_subsumed,
1603 common, remoteheads,
1604 &result_tree, wt_strategy);
1605 goto done;
1606 }
1607 /*
1609 * Pick the result from the best strategy and have the user fix
1610 * it up.
1611 */
1612 if (!best_strategy) {
1613 restore_state(&head_commit->object.oid, &stash);
1614 if (use_strategies_nr > 1)
1615 fprintf(stderr,
1616 _("No merge strategy handled the merge.\n"));
1617 else
1618 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1619 use_strategies[0]->name);
1620 ret = 2;
1621 goto done;
1622 } else if (best_strategy == wt_strategy)
1623 ; /* We already have its result in the working tree. */
1624 else {
1625 printf(_("Rewinding the tree to pristine...\n"));
1626 restore_state(&head_commit->object.oid, &stash);
1627 printf(_("Using the %s to prepare resolving by hand.\n"),
1628 best_strategy);
1629 try_merge_strategy(best_strategy, common, remoteheads,
1630 head_commit);
1631 }
1632 if (squash)
1634 finish(head_commit, remoteheads, NULL, NULL);
1635 else
1636 write_merge_state(remoteheads);
1637 if (merge_was_ok)
1639 fprintf(stderr, _("Automatic merge went well; "
1640 "stopped before committing as requested\n"));
1641 else
1642 ret = suggest_conflicts();
1643done:
1645 free(branch_to_free);
1646 return ret;
1647}