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 opterror(opt, "requires a value", 0);
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 BUG_ON_OPT_ARG(arg);
228 show_diffstat = unset;
229 return 0;
230}
231static struct option builtin_merge_options[] = {
233 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
234 N_("do not show a diffstat at the end of the merge"),
235 PARSE_OPT_NOARG, option_parse_n },
236 OPT_BOOL(0, "stat", &show_diffstat,
237 N_("show a diffstat at the end of the merge")),
238 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
239 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
240 N_("add (at most <n>) entries from shortlog to merge commit message"),
241 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
242 OPT_BOOL(0, "squash", &squash,
243 N_("create a single commit instead of doing a merge")),
244 OPT_BOOL(0, "commit", &option_commit,
245 N_("perform a commit if the merge succeeds (default)")),
246 OPT_BOOL('e', "edit", &option_edit,
247 N_("edit message before committing")),
248 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
249 OPT_SET_INT_F(0, "ff-only", &fast_forward,
250 N_("abort if fast-forward is not possible"),
251 FF_ONLY, PARSE_OPT_NONEG),
252 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
253 OPT_BOOL(0, "verify-signatures", &verify_signatures,
254 N_("verify that the named commit has a valid GPG signature")),
255 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
256 N_("merge strategy to use"), option_parse_strategy),
257 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
258 N_("option for selected merge strategy"), option_parse_x),
259 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
260 N_("merge commit message (for a non-fast-forward merge)"),
261 option_parse_message),
262 { OPTION_LOWLEVEL_CALLBACK, 'F', "file", &merge_msg, N_("path"),
263 N_("read message from file"), PARSE_OPT_NONEG,
264 (parse_opt_cb *) option_read_message },
265 OPT__VERBOSITY(&verbosity),
266 OPT_BOOL(0, "abort", &abort_current_merge,
267 N_("abort the current in-progress merge")),
268 OPT_BOOL(0, "continue", &continue_current_merge,
269 N_("continue the current in-progress merge")),
270 OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
271 N_("allow merging unrelated histories")),
272 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
273 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
274 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
275 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
276 OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
277 OPT_BOOL(0, "verify", &verify_msg, N_("verify commit-msg hook")),
278 OPT_END()
279};
280/* Cleans up metadata that is uninteresting after a succeeded merge. */
282static void drop_save(void)
283{
284 unlink(git_path_merge_head(the_repository));
285 unlink(git_path_merge_msg(the_repository));
286 unlink(git_path_merge_mode(the_repository));
287}
288static int save_state(struct object_id *stash)
290{
291 int len;
292 struct child_process cp = CHILD_PROCESS_INIT;
293 struct strbuf buffer = STRBUF_INIT;
294 const char *argv[] = {"stash", "create", NULL};
295 int rc = -1;
296 cp.argv = argv;
298 cp.out = -1;
299 cp.git_cmd = 1;
300 if (start_command(&cp))
302 die(_("could not run stash."));
303 len = strbuf_read(&buffer, cp.out, 1024);
304 close(cp.out);
305 if (finish_command(&cp) || len < 0)
307 die(_("stash failed"));
308 else if (!len) /* no changes */
309 goto out;
310 strbuf_setlen(&buffer, buffer.len-1);
311 if (get_oid(buffer.buf, stash))
312 die(_("not a valid object: %s"), buffer.buf);
313 rc = 0;
314out:
315 strbuf_release(&buffer);
316 return rc;
317}
318static void read_empty(const struct object_id *oid, int verbose)
320{
321 int i = 0;
322 const char *args[7];
323 args[i++] = "read-tree";
325 if (verbose)
326 args[i++] = "-v";
327 args[i++] = "-m";
328 args[i++] = "-u";
329 args[i++] = empty_tree_oid_hex();
330 args[i++] = oid_to_hex(oid);
331 args[i] = NULL;
332 if (run_command_v_opt(args, RUN_GIT_CMD))
334 die(_("read-tree failed"));
335}
336static void reset_hard(const struct object_id *oid, int verbose)
338{
339 int i = 0;
340 const char *args[6];
341 args[i++] = "read-tree";
343 if (verbose)
344 args[i++] = "-v";
345 args[i++] = "--reset";
346 args[i++] = "-u";
347 args[i++] = oid_to_hex(oid);
348 args[i] = NULL;
349 if (run_command_v_opt(args, RUN_GIT_CMD))
351 die(_("read-tree failed"));
352}
353static void restore_state(const struct object_id *head,
355 const struct object_id *stash)
356{
357 struct strbuf sb = STRBUF_INIT;
358 const char *args[] = { "stash", "apply", NULL, NULL };
359 if (is_null_oid(stash))
361 return;
362 reset_hard(head, 1);
364 args[2] = oid_to_hex(stash);
366 /*
368 * It is OK to ignore error here, for example when there was
369 * nothing to restore.
370 */
371 run_command_v_opt(args, RUN_GIT_CMD);
372 strbuf_release(&sb);
374 refresh_cache(REFRESH_QUIET);
375}
376/* This is called when no merge was necessary. */
378static void finish_up_to_date(const char *msg)
379{
380 if (verbosity >= 0)
381 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
382 drop_save();
383}
384static void squash_message(struct commit *commit, struct commit_list *remoteheads)
386{
387 struct rev_info rev;
388 struct strbuf out = STRBUF_INIT;
389 struct commit_list *j;
390 struct pretty_print_context ctx = {0};
391 printf(_("Squash commit -- not updating HEAD\n"));
393 repo_init_revisions(the_repository, &rev, NULL);
395 rev.ignore_merges = 1;
396 rev.commit_format = CMIT_FMT_MEDIUM;
397 commit->object.flags |= UNINTERESTING;
399 add_pending_object(&rev, &commit->object, NULL);
400 for (j = remoteheads; j; j = j->next)
402 add_pending_object(&rev, &j->item->object, NULL);
403 setup_revisions(0, NULL, &rev, NULL);
405 if (prepare_revision_walk(&rev))
406 die(_("revision walk setup failed"));
407 ctx.abbrev = rev.abbrev;
409 ctx.date_mode = rev.date_mode;
410 ctx.fmt = rev.commit_format;
411 strbuf_addstr(&out, "Squashed commit of the following:\n");
413 while ((commit = get_revision(&rev)) != NULL) {
414 strbuf_addch(&out, '\n');
415 strbuf_addf(&out, "commit %s\n",
416 oid_to_hex(&commit->object.oid));
417 pretty_print_commit(&ctx, commit, &out);
418 }
419 write_file_buf(git_path_squash_msg(the_repository), out.buf, out.len);
420 strbuf_release(&out);
421}
422static void finish(struct commit *head_commit,
424 struct commit_list *remoteheads,
425 const struct object_id *new_head, const char *msg)
426{
427 struct strbuf reflog_message = STRBUF_INIT;
428 const struct object_id *head = &head_commit->object.oid;
429 if (!msg)
431 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
432 else {
433 if (verbosity >= 0)
434 printf("%s\n", msg);
435 strbuf_addf(&reflog_message, "%s: %s",
436 getenv("GIT_REFLOG_ACTION"), msg);
437 }
438 if (squash) {
439 squash_message(head_commit, remoteheads);
440 } else {
441 if (verbosity >= 0 && !merge_msg.len)
442 printf(_("No merge message -- not updating HEAD\n"));
443 else {
444 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
445 update_ref(reflog_message.buf, "HEAD", new_head, head,
446 0, UPDATE_REFS_DIE_ON_ERR);
447 /*
448 * We ignore errors in 'gc --auto', since the
449 * user should see them.
450 */
451 close_all_packs(the_repository->objects);
452 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
453 }
454 }
455 if (new_head && show_diffstat) {
456 struct diff_options opts;
457 repo_diff_setup(the_repository, &opts);
458 opts.stat_width = -1; /* use full terminal width */
459 opts.stat_graph_width = -1; /* respect statGraphWidth config */
460 opts.output_format |=
461 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
462 opts.detect_rename = DIFF_DETECT_RENAME;
463 diff_setup_done(&opts);
464 diff_tree_oid(head, new_head, "", &opts);
465 diffcore_std(&opts);
466 diff_flush(&opts);
467 }
468 /* Run a post-merge hook */
470 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
471 strbuf_release(&reflog_message);
473}
474/* Get the name for the merge commit's message. */
476static void merge_name(const char *remote, struct strbuf *msg)
477{
478 struct commit *remote_head;
479 struct object_id branch_head;
480 struct strbuf buf = STRBUF_INIT;
481 struct strbuf bname = STRBUF_INIT;
482 struct merge_remote_desc *desc;
483 const char *ptr;
484 char *found_ref;
485 int len, early;
486 strbuf_branchname(&bname, remote, 0);
488 remote = bname.buf;
489 oidclr(&branch_head);
491 remote_head = get_merge_parent(remote);
492 if (!remote_head)
493 die(_("'%s' does not point to a commit"), remote);
494 if (dwim_ref(remote, strlen(remote), &branch_head, &found_ref) > 0) {
496 if (starts_with(found_ref, "refs/heads/")) {
497 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
498 oid_to_hex(&branch_head), remote);
499 goto cleanup;
500 }
501 if (starts_with(found_ref, "refs/tags/")) {
502 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
503 oid_to_hex(&branch_head), remote);
504 goto cleanup;
505 }
506 if (starts_with(found_ref, "refs/remotes/")) {
507 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
508 oid_to_hex(&branch_head), remote);
509 goto cleanup;
510 }
511 }
512 /* See if remote matches <name>^^^.. or <name>~<number> */
514 for (len = 0, ptr = remote + strlen(remote);
515 remote < ptr && ptr[-1] == '^';
516 ptr--)
517 len++;
518 if (len)
519 early = 1;
520 else {
521 early = 0;
522 ptr = strrchr(remote, '~');
523 if (ptr) {
524 int seen_nonzero = 0;
525 len++; /* count ~ */
527 while (*++ptr && isdigit(*ptr)) {
528 seen_nonzero |= (*ptr != '0');
529 len++;
530 }
531 if (*ptr)
532 len = 0; /* not ...~<number> */
533 else if (seen_nonzero)
534 early = 1;
535 else if (len == 1)
536 early = 1; /* "name~" is "name~1"! */
537 }
538 }
539 if (len) {
540 struct strbuf truname = STRBUF_INIT;
541 strbuf_addf(&truname, "refs/heads/%s", remote);
542 strbuf_setlen(&truname, truname.len - len);
543 if (ref_exists(truname.buf)) {
544 strbuf_addf(msg,
545 "%s\t\tbranch '%s'%s of .\n",
546 oid_to_hex(&remote_head->object.oid),
547 truname.buf + 11,
548 (early ? " (early part)" : ""));
549 strbuf_release(&truname);
550 goto cleanup;
551 }
552 strbuf_release(&truname);
553 }
554 desc = merge_remote_util(remote_head);
556 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
557 strbuf_addf(msg, "%s\t\t%s '%s'\n",
558 oid_to_hex(&desc->obj->oid),
559 type_name(desc->obj->type),
560 remote);
561 goto cleanup;
562 }
563 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
565 oid_to_hex(&remote_head->object.oid), remote);
566cleanup:
567 strbuf_release(&buf);
568 strbuf_release(&bname);
569}
570static void parse_branch_merge_options(char *bmo)
572{
573 const char **argv;
574 int argc;
575 if (!bmo)
577 return;
578 argc = split_cmdline(bmo, &argv);
579 if (argc < 0)
580 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
581 split_cmdline_strerror(argc));
582 REALLOC_ARRAY(argv, argc + 2);
583 MOVE_ARRAY(argv + 1, argv, argc + 1);
584 argc++;
585 argv[0] = "branch.*.mergeoptions";
586 parse_options(argc, argv, NULL, builtin_merge_options,
587 builtin_merge_usage, 0);
588 free(argv);
589}
590static int git_merge_config(const char *k, const char *v, void *cb)
592{
593 int status;
594 if (branch && starts_with(k, "branch.") &&
596 starts_with(k + 7, branch) &&
597 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
598 free(branch_mergeoptions);
599 branch_mergeoptions = xstrdup(v);
600 return 0;
601 }
602 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
604 show_diffstat = git_config_bool(k, v);
605 else if (!strcmp(k, "merge.verifysignatures"))
606 verify_signatures = git_config_bool(k, v);
607 else if (!strcmp(k, "pull.twohead"))
608 return git_config_string(&pull_twohead, k, v);
609 else if (!strcmp(k, "pull.octopus"))
610 return git_config_string(&pull_octopus, k, v);
611 else if (!strcmp(k, "merge.renormalize"))
612 option_renormalize = git_config_bool(k, v);
613 else if (!strcmp(k, "merge.ff")) {
614 int boolval = git_parse_maybe_bool(v);
615 if (0 <= boolval) {
616 fast_forward = boolval ? FF_ALLOW : FF_NO;
617 } else if (v && !strcmp(v, "only")) {
618 fast_forward = FF_ONLY;
619 } /* do not barf on values from future versions of git */
620 return 0;
621 } else if (!strcmp(k, "merge.defaulttoupstream")) {
622 default_to_upstream = git_config_bool(k, v);
623 return 0;
624 } else if (!strcmp(k, "commit.gpgsign")) {
625 sign_commit = git_config_bool(k, v) ? "" : NULL;
626 return 0;
627 }
628 status = fmt_merge_msg_config(k, v, cb);
630 if (status)
631 return status;
632 status = git_gpg_config(k, v, NULL);
633 if (status)
634 return status;
635 return git_diff_ui_config(k, v, cb);
636}
637static int read_tree_trivial(struct object_id *common, struct object_id *head,
639 struct object_id *one)
640{
641 int i, nr_trees = 0;
642 struct tree *trees[MAX_UNPACK_TREES];
643 struct tree_desc t[MAX_UNPACK_TREES];
644 struct unpack_trees_options opts;
645 memset(&opts, 0, sizeof(opts));
647 opts.head_idx = 2;
648 opts.src_index = &the_index;
649 opts.dst_index = &the_index;
650 opts.update = 1;
651 opts.verbose_update = 1;
652 opts.trivial_merges_only = 1;
653 opts.merge = 1;
654 trees[nr_trees] = parse_tree_indirect(common);
655 if (!trees[nr_trees++])
656 return -1;
657 trees[nr_trees] = parse_tree_indirect(head);
658 if (!trees[nr_trees++])
659 return -1;
660 trees[nr_trees] = parse_tree_indirect(one);
661 if (!trees[nr_trees++])
662 return -1;
663 opts.fn = threeway_merge;
664 cache_tree_free(&active_cache_tree);
665 for (i = 0; i < nr_trees; i++) {
666 parse_tree(trees[i]);
667 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
668 }
669 if (unpack_trees(nr_trees, t, &opts))
670 return -1;
671 return 0;
672}
673static void write_tree_trivial(struct object_id *oid)
675{
676 if (write_cache_as_tree(oid, 0, NULL))
677 die(_("git write-tree failed to write a tree"));
678}
679static int try_merge_strategy(const char *strategy, struct commit_list *common,
681 struct commit_list *remoteheads,
682 struct commit *head)
683{
684 struct lock_file lock = LOCK_INIT;
685 const char *head_arg = "HEAD";
686 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
688 refresh_cache(REFRESH_QUIET);
689 if (write_locked_index(&the_index, &lock,
690 COMMIT_LOCK | SKIP_IF_UNCHANGED))
691 return error(_("Unable to write index."));
692 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
694 int clean, x;
695 struct commit *result;
696 struct commit_list *reversed = NULL;
697 struct merge_options o;
698 struct commit_list *j;
699 if (remoteheads->next) {
701 error(_("Not handling anything other than two heads merge."));
702 return 2;
703 }
704 init_merge_options(&o);
706 if (!strcmp(strategy, "subtree"))
707 o.subtree_shift = "";
708 o.renormalize = option_renormalize;
710 o.show_rename_progress =
711 show_progress == -1 ? isatty(2) : show_progress;
712 for (x = 0; x < xopts_nr; x++)
714 if (parse_merge_opt(&o, xopts[x]))
715 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
716 o.branch1 = head_arg;
718 o.branch2 = merge_remote_util(remoteheads->item)->name;
719 for (j = common; j; j = j->next)
721 commit_list_insert(j->item, &reversed);
722 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
724 clean = merge_recursive(&o, head,
725 remoteheads->item, reversed, &result);
726 if (clean < 0)
727 exit(128);
728 if (write_locked_index(&the_index, &lock,
729 COMMIT_LOCK | SKIP_IF_UNCHANGED))
730 die(_("unable to write %s"), get_index_file());
731 return clean ? 0 : 1;
732 } else {
733 return try_merge_command(the_repository,
734 strategy, xopts_nr, xopts,
735 common, head_arg, remoteheads);
736 }
737}
738static void count_diff_files(struct diff_queue_struct *q,
740 struct diff_options *opt, void *data)
741{
742 int *count = data;
743 (*count) += q->nr;
745}
746static int count_unmerged_entries(void)
748{
749 int i, ret = 0;
750 for (i = 0; i < active_nr; i++)
752 if (ce_stage(active_cache[i]))
753 ret++;
754 return ret;
756}
757static void add_strategies(const char *string, unsigned attr)
759{
760 int i;
761 if (string) {
763 struct string_list list = STRING_LIST_INIT_DUP;
764 struct string_list_item *item;
765 string_list_split(&list, string, ' ', -1);
766 for_each_string_list_item(item, &list)
767 append_strategy(get_strategy(item->string));
768 string_list_clear(&list, 0);
769 return;
770 }
771 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
772 if (all_strategy[i].attr & attr)
773 append_strategy(&all_strategy[i]);
774}
776static void read_merge_msg(struct strbuf *msg)
778{
779 const char *filename = git_path_merge_msg(the_repository);
780 strbuf_reset(msg);
781 if (strbuf_read_file(msg, filename, 0) < 0)
782 die_errno(_("Could not read from '%s'"), filename);
783}
784static void write_merge_state(struct commit_list *);
786static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
787{
788 if (err_msg)
789 error("%s", err_msg);
790 fprintf(stderr,
791 _("Not committing merge; use 'git commit' to complete the merge.\n"));
792 write_merge_state(remoteheads);
793 exit(1);
794}
795static const char merge_editor_comment[] =
797N_("Please enter a commit message to explain why this merge is necessary,\n"
798 "especially if it merges an updated upstream into a topic branch.\n"
799 "\n"
800 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
801 "the commit.\n");
802static void write_merge_heads(struct commit_list *);
804static void prepare_to_commit(struct commit_list *remoteheads)
805{
806 struct strbuf msg = STRBUF_INIT;
807 strbuf_addbuf(&msg, &merge_msg);
808 strbuf_addch(&msg, '\n');
809 if (squash)
810 BUG("the control must not reach here under --squash");
811 if (0 < option_edit)
812 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
813 if (signoff)
814 append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
815 write_merge_heads(remoteheads);
816 write_file_buf(git_path_merge_msg(the_repository), msg.buf, msg.len);
817 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
818 git_path_merge_msg(the_repository), "merge", NULL))
819 abort_commit(remoteheads, NULL);
820 if (0 < option_edit) {
821 if (launch_editor(git_path_merge_msg(the_repository), NULL, NULL))
822 abort_commit(remoteheads, NULL);
823 }
824 if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
826 "commit-msg",
827 git_path_merge_msg(the_repository), NULL))
828 abort_commit(remoteheads, NULL);
829 read_merge_msg(&msg);
831 strbuf_stripspace(&msg, 0 < option_edit);
832 if (!msg.len)
833 abort_commit(remoteheads, _("Empty commit message."));
834 strbuf_release(&merge_msg);
835 strbuf_addbuf(&merge_msg, &msg);
836 strbuf_release(&msg);
837}
838static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
840{
841 struct object_id result_tree, result_commit;
842 struct commit_list *parents, **pptr = &parents;
843 struct lock_file lock = LOCK_INIT;
844 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
846 refresh_cache(REFRESH_QUIET);
847 if (write_locked_index(&the_index, &lock,
848 COMMIT_LOCK | SKIP_IF_UNCHANGED))
849 return error(_("Unable to write index."));
850 write_tree_trivial(&result_tree);
852 printf(_("Wonderful.\n"));
853 pptr = commit_list_append(head, pptr);
854 pptr = commit_list_append(remoteheads->item, pptr);
855 prepare_to_commit(remoteheads);
856 if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
857 &result_commit, NULL, sign_commit))
858 die(_("failed to write commit object"));
859 finish(head, remoteheads, &result_commit, "In-index merge");
860 drop_save();
861 return 0;
862}
863static int finish_automerge(struct commit *head,
865 int head_subsumed,
866 struct commit_list *common,
867 struct commit_list *remoteheads,
868 struct object_id *result_tree,
869 const char *wt_strategy)
870{
871 struct commit_list *parents = NULL;
872 struct strbuf buf = STRBUF_INIT;
873 struct object_id result_commit;
874 free_commit_list(common);
876 parents = remoteheads;
877 if (!head_subsumed || fast_forward == FF_NO)
878 commit_list_insert(head, &parents);
879 strbuf_addch(&merge_msg, '\n');
880 prepare_to_commit(remoteheads);
881 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
882 &result_commit, NULL, sign_commit))
883 die(_("failed to write commit object"));
884 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
885 finish(head, remoteheads, &result_commit, buf.buf);
886 strbuf_release(&buf);
887 drop_save();
888 return 0;
889}
890static int suggest_conflicts(void)
892{
893 const char *filename;
894 FILE *fp;
895 struct strbuf msgbuf = STRBUF_INIT;
896 filename = git_path_merge_msg(the_repository);
898 fp = xfopen(filename, "a");
899 append_conflicts_hint(&msgbuf);
901 fputs(msgbuf.buf, fp);
902 strbuf_release(&msgbuf);
903 fclose(fp);
904 repo_rerere(the_repository, allow_rerere_auto);
905 printf(_("Automatic merge failed; "
906 "fix conflicts and then commit the result.\n"));
907 return 1;
908}
909static int evaluate_result(void)
911{
912 int cnt = 0;
913 struct rev_info rev;
914 /* Check how many files differ. */
916 repo_init_revisions(the_repository, &rev, "");
917 setup_revisions(0, NULL, &rev, NULL);
918 rev.diffopt.output_format |=
919 DIFF_FORMAT_CALLBACK;
920 rev.diffopt.format_callback = count_diff_files;
921 rev.diffopt.format_callback_data = &cnt;
922 run_diff_files(&rev, 0);
923 /*
925 * Check how many unmerged entries are
926 * there.
927 */
928 cnt += count_unmerged_entries();
929 return cnt;
931}
932/*
934 * Pretend as if the user told us to merge with the remote-tracking
935 * branch we have for the upstream of the current branch
936 */
937static int setup_with_upstream(const char ***argv)
938{
939 struct branch *branch = branch_get(NULL);
940 int i;
941 const char **args;
942 if (!branch)
944 die(_("No current branch."));
945 if (!branch->remote_name)
946 die(_("No remote for the current branch."));
947 if (!branch->merge_nr)
948 die(_("No default upstream defined for the current branch."));
949 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
951 for (i = 0; i < branch->merge_nr; i++) {
952 if (!branch->merge[i]->dst)
953 die(_("No remote-tracking branch for %s from %s"),
954 branch->merge[i]->src, branch->remote_name);
955 args[i] = branch->merge[i]->dst;
956 }
957 args[i] = NULL;
958 *argv = args;
959 return i;
960}
961static void write_merge_heads(struct commit_list *remoteheads)
963{
964 struct commit_list *j;
965 struct strbuf buf = STRBUF_INIT;
966 for (j = remoteheads; j; j = j->next) {
968 struct object_id *oid;
969 struct commit *c = j->item;
970 struct merge_remote_desc *desc;
971 desc = merge_remote_util(c);
973 if (desc && desc->obj) {
974 oid = &desc->obj->oid;
975 } else {
976 oid = &c->object.oid;
977 }
978 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
979 }
980 write_file_buf(git_path_merge_head(the_repository), buf.buf, buf.len);
981 strbuf_reset(&buf);
983 if (fast_forward == FF_NO)
984 strbuf_addstr(&buf, "no-ff");
985 write_file_buf(git_path_merge_mode(the_repository), buf.buf, buf.len);
986 strbuf_release(&buf);
987}
988static void write_merge_state(struct commit_list *remoteheads)
990{
991 write_merge_heads(remoteheads);
992 strbuf_addch(&merge_msg, '\n');
993 write_file_buf(git_path_merge_msg(the_repository), merge_msg.buf,
994 merge_msg.len);
995}
996static int default_edit_option(void)
998{
999 static const char name[] = "GIT_MERGE_AUTOEDIT";
1000 const char *e = getenv(name);
1001 struct stat st_stdin, st_stdout;
1002 if (have_message)
1004 /* an explicit -m msg without --[no-]edit */
1005 return 0;
1006 if (e) {
1008 int v = git_parse_maybe_bool(e);
1009 if (v < 0)
1010 die(_("Bad value '%s' in environment '%s'"), e, name);
1011 return v;
1012 }
1013 /* Use editor if stdin and stdout are the same and is a tty */
1015 return (!fstat(0, &st_stdin) &&
1016 !fstat(1, &st_stdout) &&
1017 isatty(0) && isatty(1) &&
1018 st_stdin.st_dev == st_stdout.st_dev &&
1019 st_stdin.st_ino == st_stdout.st_ino &&
1020 st_stdin.st_mode == st_stdout.st_mode);
1021}
1022static struct commit_list *reduce_parents(struct commit *head_commit,
1024 int *head_subsumed,
1025 struct commit_list *remoteheads)
1026{
1027 struct commit_list *parents, **remotes;
1028 /*
1030 * Is the current HEAD reachable from another commit being
1031 * merged? If so we do not want to record it as a parent of
1032 * the resulting merge, unless --no-ff is given. We will flip
1033 * this variable to 0 when we find HEAD among the independent
1034 * tips being merged.
1035 */
1036 *head_subsumed = 1;
1037 /* Find what parents to record by checking independent ones. */
1039 parents = reduce_heads(remoteheads);
1040 free_commit_list(remoteheads);
1041 remoteheads = NULL;
1043 remotes = &remoteheads;
1044 while (parents) {
1045 struct commit *commit = pop_commit(&parents);
1046 if (commit == head_commit)
1047 *head_subsumed = 0;
1048 else
1049 remotes = &commit_list_insert(commit, remotes)->next;
1050 }
1051 return remoteheads;
1052}
1053static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1055{
1056 struct fmt_merge_msg_opts opts;
1057 memset(&opts, 0, sizeof(opts));
1059 opts.add_title = !have_message;
1060 opts.shortlog_len = shortlog_len;
1061 opts.credit_people = (0 < option_edit);
1062 fmt_merge_msg(merge_names, merge_msg, &opts);
1064 if (merge_msg->len)
1065 strbuf_setlen(merge_msg, merge_msg->len - 1);
1066}
1067static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1069{
1070 const char *filename;
1071 int fd, pos, npos;
1072 struct strbuf fetch_head_file = STRBUF_INIT;
1073 const unsigned hexsz = the_hash_algo->hexsz;
1074 if (!merge_names)
1076 merge_names = &fetch_head_file;
1077 filename = git_path_fetch_head(the_repository);
1079 fd = open(filename, O_RDONLY);
1080 if (fd < 0)
1081 die_errno(_("could not open '%s' for reading"), filename);
1082 if (strbuf_read(merge_names, fd, 0) < 0)
1084 die_errno(_("could not read '%s'"), filename);
1085 if (close(fd) < 0)
1086 die_errno(_("could not close '%s'"), filename);
1087 for (pos = 0; pos < merge_names->len; pos = npos) {
1089 struct object_id oid;
1090 char *ptr;
1091 struct commit *commit;
1092 ptr = strchr(merge_names->buf + pos, '\n');
1094 if (ptr)
1095 npos = ptr - merge_names->buf + 1;
1096 else
1097 npos = merge_names->len;
1098 if (npos - pos < hexsz + 2 ||
1100 get_oid_hex(merge_names->buf + pos, &oid))
1101 commit = NULL; /* bad */
1102 else if (memcmp(merge_names->buf + pos + hexsz, "\t\t", 2))
1103 continue; /* not-for-merge */
1104 else {
1105 char saved = merge_names->buf[pos + hexsz];
1106 merge_names->buf[pos + hexsz] = '\0';
1107 commit = get_merge_parent(merge_names->buf + pos);
1108 merge_names->buf[pos + hexsz] = saved;
1109 }
1110 if (!commit) {
1111 if (ptr)
1112 *ptr = '\0';
1113 die(_("not something we can merge in %s: %s"),
1114 filename, merge_names->buf + pos);
1115 }
1116 remotes = &commit_list_insert(commit, remotes)->next;
1117 }
1118 if (merge_names == &fetch_head_file)
1120 strbuf_release(&fetch_head_file);
1121}
1122static struct commit_list *collect_parents(struct commit *head_commit,
1124 int *head_subsumed,
1125 int argc, const char **argv,
1126 struct strbuf *merge_msg)
1127{
1128 int i;
1129 struct commit_list *remoteheads = NULL;
1130 struct commit_list **remotes = &remoteheads;
1131 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1132 if (merge_msg && (!have_message || shortlog_len))
1134 autogen = &merge_names;
1135 if (head_commit)
1137 remotes = &commit_list_insert(head_commit, remotes)->next;
1138 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1140 handle_fetch_head(remotes, autogen);
1141 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1142 } else {
1143 for (i = 0; i < argc; i++) {
1144 struct commit *commit = get_merge_parent(argv[i]);
1145 if (!commit)
1146 help_unknown_ref(argv[i], "merge",
1147 _("not something we can merge"));
1148 remotes = &commit_list_insert(commit, remotes)->next;
1149 }
1150 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1151 if (autogen) {
1152 struct commit_list *p;
1153 for (p = remoteheads; p; p = p->next)
1154 merge_name(merge_remote_util(p->item)->name, autogen);
1155 }
1156 }
1157 if (autogen) {
1159 prepare_merge_message(autogen, merge_msg);
1160 strbuf_release(autogen);
1161 }
1162 return remoteheads;
1164}
1165static int merging_a_throwaway_tag(struct commit *commit)
1167{
1168 char *tag_ref;
1169 struct object_id oid;
1170 int is_throwaway_tag = 0;
1171 /* Are we merging a tag? */
1173 if (!merge_remote_util(commit) ||
1174 !merge_remote_util(commit)->obj ||
1175 merge_remote_util(commit)->obj->type != OBJ_TAG)
1176 return is_throwaway_tag;
1177 /*
1179 * Now we know we are merging a tag object. Are we downstream
1180 * and following the tags from upstream? If so, we must have
1181 * the tag object pointed at by "refs/tags/$T" where $T is the
1182 * tagname recorded in the tag object. We want to allow such
1183 * a "just to catch up" merge to fast-forward.
1184 *
1185 * Otherwise, we are playing an integrator's role, making a
1186 * merge with a throw-away tag from a contributor with
1187 * something like "git pull $contributor $signed_tag".
1188 * We want to forbid such a merge from fast-forwarding
1189 * by default; otherwise we would not keep the signature
1190 * anywhere.
1191 */
1192 tag_ref = xstrfmt("refs/tags/%s",
1193 ((struct tag *)merge_remote_util(commit)->obj)->tag);
1194 if (!read_ref(tag_ref, &oid) &&
1195 oideq(&oid, &merge_remote_util(commit)->obj->oid))
1196 is_throwaway_tag = 0;
1197 else
1198 is_throwaway_tag = 1;
1199 free(tag_ref);
1200 return is_throwaway_tag;
1201}
1202int cmd_merge(int argc, const char **argv, const char *prefix)
1204{
1205 struct object_id result_tree, stash, head_oid;
1206 struct commit *head_commit;
1207 struct strbuf buf = STRBUF_INIT;
1208 int i, ret = 0, head_subsumed;
1209 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1210 struct commit_list *common = NULL;
1211 const char *best_strategy = NULL, *wt_strategy = NULL;
1212 struct commit_list *remoteheads, *p;
1213 void *branch_to_free;
1214 int orig_argc = argc;
1215 if (argc == 2 && !strcmp(argv[1], "-h"))
1217 usage_with_options(builtin_merge_usage, builtin_merge_options);
1218 /*
1220 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1221 * current branch.
1222 */
1223 branch = branch_to_free = resolve_refdup("HEAD", 0, &head_oid, NULL);
1224 if (branch)
1225 skip_prefix(branch, "refs/heads/", &branch);
1226 init_diff_ui_defaults();
1228 git_config(git_merge_config, NULL);
1229 if (!branch || is_null_oid(&head_oid))
1231 head_commit = NULL;
1232 else
1233 head_commit = lookup_commit_or_die(&head_oid, "HEAD");
1234 if (branch_mergeoptions)
1236 parse_branch_merge_options(branch_mergeoptions);
1237 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1238 builtin_merge_usage, 0);
1239 if (shortlog_len < 0)
1240 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1241 if (verbosity < 0 && show_progress == -1)
1243 show_progress = 0;
1244 if (abort_current_merge) {
1246 int nargc = 2;
1247 const char *nargv[] = {"reset", "--merge", NULL};
1248 if (orig_argc != 2)
1250 usage_msg_opt(_("--abort expects no arguments"),
1251 builtin_merge_usage, builtin_merge_options);
1252 if (!file_exists(git_path_merge_head(the_repository)))
1254 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1255 /* Invoke 'git reset --merge' */
1257 ret = cmd_reset(nargc, nargv, prefix);
1258 goto done;
1259 }
1260 if (continue_current_merge) {
1262 int nargc = 1;
1263 const char *nargv[] = {"commit", NULL};
1264 if (orig_argc != 2)
1266 usage_msg_opt(_("--continue expects no arguments"),
1267 builtin_merge_usage, builtin_merge_options);
1268 if (!file_exists(git_path_merge_head(the_repository)))
1270 die(_("There is no merge in progress (MERGE_HEAD missing)."));
1271 /* Invoke 'git commit' */
1273 ret = cmd_commit(nargc, nargv, prefix);
1274 goto done;
1275 }
1276 if (read_cache_unmerged())
1278 die_resolve_conflict("merge");
1279 if (file_exists(git_path_merge_head(the_repository))) {
1281 /*
1282 * There is no unmerged entry, don't advise 'git
1283 * add/rm <file>', just 'git commit'.
1284 */
1285 if (advice_resolve_conflict)
1286 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1287 "Please, commit your changes before you merge."));
1288 else
1289 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1290 }
1291 if (file_exists(git_path_cherry_pick_head(the_repository))) {
1292 if (advice_resolve_conflict)
1293 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1294 "Please, commit your changes before you merge."));
1295 else
1296 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1297 }
1298 resolve_undo_clear();
1299 if (verbosity < 0)
1301 show_diffstat = 0;
1302 if (squash) {
1304 if (fast_forward == FF_NO)
1305 die(_("You cannot combine --squash with --no-ff."));
1306 option_commit = 0;
1307 }
1308 if (!argc) {
1310 if (default_to_upstream)
1311 argc = setup_with_upstream(&argv);
1312 else
1313 die(_("No commit specified and merge.defaultToUpstream not set."));
1314 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1315 argv[0] = "@{-1}";
1316 }
1317 if (!argc)
1319 usage_with_options(builtin_merge_usage,
1320 builtin_merge_options);
1321 if (!head_commit) {
1323 /*
1324 * If the merged head is a valid one there is no reason
1325 * to forbid "git merge" into a branch yet to be born.
1326 * We do the same for "git pull".
1327 */
1328 struct object_id *remote_head_oid;
1329 if (squash)
1330 die(_("Squash commit into empty head not supported yet"));
1331 if (fast_forward == FF_NO)
1332 die(_("Non-fast-forward commit does not make sense into "
1333 "an empty head"));
1334 remoteheads = collect_parents(head_commit, &head_subsumed,
1335 argc, argv, NULL);
1336 if (!remoteheads)
1337 die(_("%s - not something we can merge"), argv[0]);
1338 if (remoteheads->next)
1339 die(_("Can merge only exactly one commit into empty head"));
1340 if (verify_signatures)
1342 verify_merge_signature(remoteheads->item, verbosity);
1343 remote_head_oid = &remoteheads->item->object.oid;
1345 read_empty(remote_head_oid, 0);
1346 update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
1347 UPDATE_REFS_DIE_ON_ERR);
1348 goto done;
1349 }
1350 /*
1352 * All the rest are the commits being merged; prepare
1353 * the standard merge summary message to be appended
1354 * to the given message.
1355 */
1356 remoteheads = collect_parents(head_commit, &head_subsumed,
1357 argc, argv, &merge_msg);
1358 if (!head_commit || !argc)
1360 usage_with_options(builtin_merge_usage,
1361 builtin_merge_options);
1362 if (verify_signatures) {
1364 for (p = remoteheads; p; p = p->next) {
1365 verify_merge_signature(p->item, verbosity);
1366 }
1367 }
1368 strbuf_addstr(&buf, "merge");
1370 for (p = remoteheads; p; p = p->next)
1371 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1372 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1373 strbuf_reset(&buf);
1374 for (p = remoteheads; p; p = p->next) {
1376 struct commit *commit = p->item;
1377 strbuf_addf(&buf, "GITHEAD_%s",
1378 oid_to_hex(&commit->object.oid));
1379 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1380 strbuf_reset(&buf);
1381 if (fast_forward != FF_ONLY && merging_a_throwaway_tag(commit))
1382 fast_forward = FF_NO;
1383 }
1384 if (option_edit < 0)
1386 option_edit = default_edit_option();
1387 if (!use_strategies) {
1389 if (!remoteheads)
1390 ; /* already up-to-date */
1391 else if (!remoteheads->next)
1392 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1393 else
1394 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1395 }
1396 for (i = 0; i < use_strategies_nr; i++) {
1398 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1399 fast_forward = FF_NO;
1400 if (use_strategies[i]->attr & NO_TRIVIAL)
1401 allow_trivial = 0;
1402 }
1403 if (!remoteheads)
1405 ; /* already up-to-date */
1406 else if (!remoteheads->next)
1407 common = get_merge_bases(head_commit, remoteheads->item);
1408 else {
1409 struct commit_list *list = remoteheads;
1410 commit_list_insert(head_commit, &list);
1411 common = get_octopus_merge_bases(list);
1412 free(list);
1413 }
1414 update_ref("updating ORIG_HEAD", "ORIG_HEAD",
1416 &head_commit->object.oid, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1417 if (remoteheads && !common) {
1419 /* No common ancestors found. */
1420 if (!allow_unrelated_histories)
1421 die(_("refusing to merge unrelated histories"));
1422 /* otherwise, we need a real merge. */
1423 } else if (!remoteheads ||
1424 (!remoteheads->next && !common->next &&
1425 common->item == remoteheads->item)) {
1426 /*
1427 * If head can reach all the merge then we are up to date.
1428 * but first the most common case of merging one remote.
1429 */
1430 finish_up_to_date(_("Already up to date."));
1431 goto done;
1432 } else if (fast_forward != FF_NO && !remoteheads->next &&
1433 !common->next &&
1434 oideq(&common->item->object.oid, &head_commit->object.oid)) {
1435 /* Again the most common case of merging one remote. */
1436 struct strbuf msg = STRBUF_INIT;
1437 struct commit *commit;
1438 if (verbosity >= 0) {
1440 printf(_("Updating %s..%s\n"),
1441 find_unique_abbrev(&head_commit->object.oid,
1442 DEFAULT_ABBREV),
1443 find_unique_abbrev(&remoteheads->item->object.oid,
1444 DEFAULT_ABBREV));
1445 }
1446 strbuf_addstr(&msg, "Fast-forward");
1447 if (have_message)
1448 strbuf_addstr(&msg,
1449 " (no commit created; -m option ignored)");
1450 commit = remoteheads->item;
1451 if (!commit) {
1452 ret = 1;
1453 goto done;
1454 }
1455 if (checkout_fast_forward(the_repository,
1457 &head_commit->object.oid,
1458 &commit->object.oid,
1459 overwrite_ignore)) {
1460 ret = 1;
1461 goto done;
1462 }
1463 finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
1465 drop_save();
1466 goto done;
1467 } else if (!remoteheads->next && common->next)
1468 ;
1469 /*
1470 * We are not doing octopus and not fast-forward. Need
1471 * a real merge.
1472 */
1473 else if (!remoteheads->next && !common->next && option_commit) {
1474 /*
1475 * We are not doing octopus, not fast-forward, and have
1476 * only one common.
1477 */
1478 refresh_cache(REFRESH_QUIET);
1479 if (allow_trivial && fast_forward != FF_ONLY) {
1480 /* See if it is really trivial. */
1481 git_committer_info(IDENT_STRICT);
1482 printf(_("Trying really trivial in-index merge...\n"));
1483 if (!read_tree_trivial(&common->item->object.oid,
1484 &head_commit->object.oid,
1485 &remoteheads->item->object.oid)) {
1486 ret = merge_trivial(head_commit, remoteheads);
1487 goto done;
1488 }
1489 printf(_("Nope.\n"));
1490 }
1491 } else {
1492 /*
1493 * An octopus. If we can reach all the remote we are up
1494 * to date.
1495 */
1496 int up_to_date = 1;
1497 struct commit_list *j;
1498 for (j = remoteheads; j; j = j->next) {
1500 struct commit_list *common_one;
1501 /*
1503 * Here we *have* to calculate the individual
1504 * merge_bases again, otherwise "git merge HEAD^
1505 * HEAD^^" would be missed.
1506 */
1507 common_one = get_merge_bases(head_commit, j->item);
1508 if (!oideq(&common_one->item->object.oid, &j->item->object.oid)) {
1509 up_to_date = 0;
1510 break;
1511 }
1512 }
1513 if (up_to_date) {
1514 finish_up_to_date(_("Already up to date. Yeeah!"));
1515 goto done;
1516 }
1517 }
1518 if (fast_forward == FF_ONLY)
1520 die(_("Not possible to fast-forward, aborting."));
1521 /* We are going to make a new commit. */
1523 git_committer_info(IDENT_STRICT);
1524 /*
1526 * At this point, we need a real merge. No matter what strategy
1527 * we use, it would operate on the index, possibly affecting the
1528 * working tree, and when resolved cleanly, have the desired
1529 * tree in the index -- this means that the index must be in
1530 * sync with the head commit. The strategies are responsible
1531 * to ensure this.
1532 */
1533 if (use_strategies_nr == 1 ||
1534 /*
1535 * Stash away the local changes so that we can try more than one.
1536 */
1537 save_state(&stash))
1538 oidclr(&stash);
1539 for (i = 0; i < use_strategies_nr; i++) {
1541 int ret;
1542 if (i) {
1543 printf(_("Rewinding the tree to pristine...\n"));
1544 restore_state(&head_commit->object.oid, &stash);
1545 }
1546 if (use_strategies_nr != 1)
1547 printf(_("Trying merge strategy %s...\n"),
1548 use_strategies[i]->name);
1549 /*
1550 * Remember which strategy left the state in the working
1551 * tree.
1552 */
1553 wt_strategy = use_strategies[i]->name;
1554 ret = try_merge_strategy(use_strategies[i]->name,
1556 common, remoteheads,
1557 head_commit);
1558 if (!option_commit && !ret) {
1559 merge_was_ok = 1;
1560 /*
1561 * This is necessary here just to avoid writing
1562 * the tree, but later we will *not* exit with
1563 * status code 1 because merge_was_ok is set.
1564 */
1565 ret = 1;
1566 }
1567 if (ret) {
1569 /*
1570 * The backend exits with 1 when conflicts are
1571 * left to be resolved, with 2 when it does not
1572 * handle the given merge at all.
1573 */
1574 if (ret == 1) {
1575 int cnt = evaluate_result();
1576 if (best_cnt <= 0 || cnt <= best_cnt) {
1578 best_strategy = use_strategies[i]->name;
1579 best_cnt = cnt;
1580 }
1581 }
1582 if (merge_was_ok)
1583 break;
1584 else
1585 continue;
1586 }
1587 /* Automerge succeeded. */
1589 write_tree_trivial(&result_tree);
1590 automerge_was_ok = 1;
1591 break;
1592 }
1593 /*
1595 * If we have a resulting tree, that means the strategy module
1596 * auto resolved the merge cleanly.
1597 */
1598 if (automerge_was_ok) {
1599 ret = finish_automerge(head_commit, head_subsumed,
1600 common, remoteheads,
1601 &result_tree, wt_strategy);
1602 goto done;
1603 }
1604 /*
1606 * Pick the result from the best strategy and have the user fix
1607 * it up.
1608 */
1609 if (!best_strategy) {
1610 restore_state(&head_commit->object.oid, &stash);
1611 if (use_strategies_nr > 1)
1612 fprintf(stderr,
1613 _("No merge strategy handled the merge.\n"));
1614 else
1615 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1616 use_strategies[0]->name);
1617 ret = 2;
1618 goto done;
1619 } else if (best_strategy == wt_strategy)
1620 ; /* We already have its result in the working tree. */
1621 else {
1622 printf(_("Rewinding the tree to pristine...\n"));
1623 restore_state(&head_commit->object.oid, &stash);
1624 printf(_("Using the %s to prepare resolving by hand.\n"),
1625 best_strategy);
1626 try_merge_strategy(best_strategy, common, remoteheads,
1627 head_commit);
1628 }
1629 if (squash)
1631 finish(head_commit, remoteheads, NULL, NULL);
1632 else
1633 write_merge_state(remoteheads);
1634 if (merge_was_ok)
1636 fprintf(stderr, _("Automatic merge went well; "
1637 "stopped before committing as requested\n"));
1638 else
1639 ret = suggest_conflicts();
1640done:
1642 free(branch_to_free);
1643 return ret;
1644}