e9663f027ada2807e62a1ce625d2bffca0332dac
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#define USE_THE_INDEX_COMPATIBILITY_MACROS
10#include "cache.h"
11#include "config.h"
12#include "parse-options.h"
13#include "builtin.h"
14#include "lockfile.h"
15#include "run-command.h"
16#include "diff.h"
17#include "refs.h"
18#include "refspec.h"
19#include "commit.h"
20#include "diffcore.h"
21#include "revision.h"
22#include "unpack-trees.h"
23#include "cache-tree.h"
24#include "dir.h"
25#include "utf8.h"
26#include "log-tree.h"
27#include "color.h"
28#include "rerere.h"
29#include "help.h"
30#include "merge-recursive.h"
31#include "resolve-undo.h"
32#include "remote.h"
33#include "fmt-merge-msg.h"
34#include "gpg-interface.h"
35#include "sequencer.h"
36#include "string-list.h"
37#include "packfile.h"
38#include "tag.h"
39#include "alias.h"
40#include "branch.h"
41#include "commit-reach.h"
42#define DEFAULT_TWOHEAD (1<<0)
44#define DEFAULT_OCTOPUS (1<<1)
45#define NO_FAST_FORWARD (1<<2)
46#define NO_TRIVIAL (1<<3)
47struct strategy {
49 const char *name;
50 unsigned attr;
51};
52static const char * const builtin_merge_usage[] = {
54 N_("git merge [<options>] [<commit>...]"),
55 N_("git merge --abort"),
56 N_("git merge --continue"),
57 NULL
58};
59static int show_diffstat = 1, shortlog_len = -1, squash;
61static int option_commit = 1;
62static int option_edit = -1;
63static int allow_trivial = 1, have_message, verify_signatures;
64static int overwrite_ignore = 1;
65static struct strbuf merge_msg = STRBUF_INIT;
66static struct strategy **use_strategies;
67static size_t use_strategies_nr, use_strategies_alloc;
68static const char **xopts;
69static size_t xopts_nr, xopts_alloc;
70static const char *branch;
71static char *branch_mergeoptions;
72static int option_renormalize;
73static int verbosity;
74static int allow_rerere_auto;
75static int abort_current_merge;
76static int continue_current_merge;
77static int allow_unrelated_histories;
78static int show_progress = -1;
79static int default_to_upstream = 1;
80static int signoff;
81static const char *sign_commit;
82static int verify_msg = 1;
83static struct strategy all_strategy[] = {
85 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
86 { "octopus", DEFAULT_OCTOPUS },
87 { "resolve", 0 },
88 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
89 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
90};
91static const char *pull_twohead, *pull_octopus;
93enum ff_type {
95 FF_NO,
96 FF_ALLOW,
97 FF_ONLY
98};
99static enum ff_type fast_forward = FF_ALLOW;
101static int option_parse_message(const struct option *opt,
103 const char *arg, int unset)
104{
105 struct strbuf *buf = opt->value;
106 if (unset)
108 strbuf_setlen(buf, 0);
109 else if (arg) {
110 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
111 have_message = 1;
112 } else
113 return error(_("switch `m' requires a value"));
114 return 0;
115}
116static int option_read_message(struct parse_opt_ctx_t *ctx,
118 const struct option *opt, int unset)
119{
120 struct strbuf *buf = opt->value;
121 const char *arg;
122 if (unset)
124 BUG("-F cannot be negated");
125 if (ctx->opt) {
127 arg = ctx->opt;
128 ctx->opt = NULL;
129 } else if (ctx->argc > 1) {
130 ctx->argc--;
131 arg = *++ctx->argv;
132 } else
133 return error(_("option `%s' requires a value"), opt->long_name);
134 if (buf->len)
136 strbuf_addch(buf, '\n');
137 if (ctx->prefix && !is_absolute_path(arg))
138 arg = prefix_filename(ctx->prefix, arg);
139 if (strbuf_read_file(buf, arg, 0) < 0)
140 return error(_("could not read file '%s'"), arg);
141 have_message = 1;
142 return 0;
144}
145static struct strategy *get_strategy(const char *name)
147{
148 int i;
149 struct strategy *ret;
150 static struct cmdnames main_cmds, other_cmds;
151 static int loaded;
152 if (!name)
154 return NULL;
155 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
157 if (!strcmp(name, all_strategy[i].name))
158 return &all_strategy[i];
159 if (!loaded) {
161 struct cmdnames not_strategies;
162 loaded = 1;
163 memset(¬_strategies, 0, sizeof(struct cmdnames));
165 load_command_list("git-merge-", &main_cmds, &other_cmds);
166 for (i = 0; i < main_cmds.cnt; i++) {
167 int j, found = 0;
168 struct cmdname *ent = main_cmds.names[i];
169 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
170 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
171 && !all_strategy[j].name[ent->len])
172 found = 1;
173 if (!found)
174 add_cmdname(¬_strategies, ent->name, ent->len);
175 }
176 exclude_cmds(&main_cmds, ¬_strategies);
177 }
178 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
179 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
180 fprintf(stderr, _("Available strategies are:"));
181 for (i = 0; i < main_cmds.cnt; i++)
182 fprintf(stderr, " %s", main_cmds.names[i]->name);
183 fprintf(stderr, ".\n");
184 if (other_cmds.cnt) {
185 fprintf(stderr, _("Available custom strategies are:"));
186 for (i = 0; i < other_cmds.cnt; i++)
187 fprintf(stderr, " %s", other_cmds.names[i]->name);
188 fprintf(stderr, ".\n");
189 }
190 exit(1);
191 }
192 ret = xcalloc(1, sizeof(struct strategy));
194 ret->name = xstrdup(name);
195 ret->attr = NO_TRIVIAL;
196 return ret;
197}
198static void append_strategy(struct strategy *s)
200{
201 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
202 use_strategies[use_strategies_nr++] = s;
203}
204static int option_parse_strategy(const struct option *opt,
206 const char *name, int unset)
207{
208 if (unset)
209 return 0;
210 append_strategy(get_strategy(name));
212 return 0;
213}
214static int option_parse_x(const struct option *opt,
216 const char *arg, int unset)
217{
218 if (unset)
219 return 0;
220 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
222 xopts[xopts_nr++] = xstrdup(arg);
223 return 0;
224}
225static int option_parse_n(const struct option *opt,
227 const char *arg, int unset)
228{
229 BUG_ON_OPT_ARG(arg);
230 show_diffstat = unset;
231 return 0;
232}
233static struct option builtin_merge_options[] = {
235 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
236 N_("do not show a diffstat at the end of the merge"),
237 PARSE_OPT_NOARG, option_parse_n },
238 OPT_BOOL(0, "stat", &show_diffstat,
239 N_("show a diffstat at the end of the merge")),
240 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
241 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
242 N_("add (at most <n>) entries from shortlog to merge commit message"),
243 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
244 OPT_BOOL(0, "squash", &squash,
245 N_("create a single commit instead of doing a merge")),
246 OPT_BOOL(0, "commit", &option_commit,
247 N_("perform a commit if the merge succeeds (default)")),
248 OPT_BOOL('e', "edit", &option_edit,
249 N_("edit message before committing")),
250 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
251 OPT_SET_INT_F(0, "ff-only", &fast_forward,
252 N_("abort if fast-forward is not possible"),
253 FF_ONLY, PARSE_OPT_NONEG),
254 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
255 OPT_BOOL(0, "verify-signatures", &verify_signatures,
256 N_("verify that the named commit has a valid GPG signature")),
257 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
258 N_("merge strategy to use"), option_parse_strategy),
259 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
260 N_("option for selected merge strategy"), option_parse_x),
261 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
262 N_("merge commit message (for a non-fast-forward merge)"),
263 option_parse_message),
264 { OPTION_LOWLEVEL_CALLBACK, 'F', "file", &merge_msg, N_("path"),
265 N_("read message from file"), PARSE_OPT_NONEG,
266 (parse_opt_cb *) option_read_message },
267 OPT__VERBOSITY(&verbosity),
268 OPT_BOOL(0, "abort", &abort_current_merge,
269 N_("abort the current in-progress merge")),
270 OPT_BOOL(0, "continue", &continue_current_merge,
271 N_("continue the current in-progress merge")),
272 OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
273 N_("allow merging unrelated histories")),
274 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
275 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
276 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
277 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
278 OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
279 OPT_BOOL(0, "verify", &verify_msg, N_("verify commit-msg hook")),
280 OPT_END()
281};
282static int save_state(struct object_id *stash)
284{
285 int len;
286 struct child_process cp = CHILD_PROCESS_INIT;
287 struct strbuf buffer = STRBUF_INIT;
288 const char *argv[] = {"stash", "create", NULL};
289 int rc = -1;
290 cp.argv = argv;
292 cp.out = -1;
293 cp.git_cmd = 1;
294 if (start_command(&cp))
296 die(_("could not run stash."));
297 len = strbuf_read(&buffer, cp.out, 1024);
298 close(cp.out);
299 if (finish_command(&cp) || len < 0)
301 die(_("stash failed"));
302 else if (!len) /* no changes */
303 goto out;
304 strbuf_setlen(&buffer, buffer.len-1);
305 if (get_oid(buffer.buf, stash))
306 die(_("not a valid object: %s"), buffer.buf);
307 rc = 0;
308out:
309 strbuf_release(&buffer);
310 return rc;
311}
312static void read_empty(const struct object_id *oid, int verbose)
314{
315 int i = 0;
316 const char *args[7];
317 args[i++] = "read-tree";
319 if (verbose)
320 args[i++] = "-v";
321 args[i++] = "-m";
322 args[i++] = "-u";
323 args[i++] = empty_tree_oid_hex();
324 args[i++] = oid_to_hex(oid);
325 args[i] = NULL;
326 if (run_command_v_opt(args, RUN_GIT_CMD))
328 die(_("read-tree failed"));
329}
330static void reset_hard(const struct object_id *oid, int verbose)
332{
333 int i = 0;
334 const char *args[6];
335 args[i++] = "read-tree";
337 if (verbose)
338 args[i++] = "-v";
339 args[i++] = "--reset";
340 args[i++] = "-u";
341 args[i++] = oid_to_hex(oid);
342 args[i] = NULL;
343 if (run_command_v_opt(args, RUN_GIT_CMD))
345 die(_("read-tree failed"));
346}
347static void restore_state(const struct object_id *head,
349 const struct object_id *stash)
350{
351 struct strbuf sb = STRBUF_INIT;
352 const char *args[] = { "stash", "apply", NULL, NULL };
353 if (is_null_oid(stash))
355 return;
356 reset_hard(head, 1);
358 args[2] = oid_to_hex(stash);
360 /*
362 * It is OK to ignore error here, for example when there was
363 * nothing to restore.
364 */
365 run_command_v_opt(args, RUN_GIT_CMD);
366 strbuf_release(&sb);
368 refresh_cache(REFRESH_QUIET);
369}
370/* This is called when no merge was necessary. */
372static void finish_up_to_date(const char *msg)
373{
374 if (verbosity >= 0)
375 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
376 remove_merge_branch_state(the_repository);
377}
378static void squash_message(struct commit *commit, struct commit_list *remoteheads)
380{
381 struct rev_info rev;
382 struct strbuf out = STRBUF_INIT;
383 struct commit_list *j;
384 struct pretty_print_context ctx = {0};
385 printf(_("Squash commit -- not updating HEAD\n"));
387 repo_init_revisions(the_repository, &rev, NULL);
389 rev.ignore_merges = 1;
390 rev.commit_format = CMIT_FMT_MEDIUM;
391 commit->object.flags |= UNINTERESTING;
393 add_pending_object(&rev, &commit->object, NULL);
394 for (j = remoteheads; j; j = j->next)
396 add_pending_object(&rev, &j->item->object, NULL);
397 setup_revisions(0, NULL, &rev, NULL);
399 if (prepare_revision_walk(&rev))
400 die(_("revision walk setup failed"));
401 ctx.abbrev = rev.abbrev;
403 ctx.date_mode = rev.date_mode;
404 ctx.fmt = rev.commit_format;
405 strbuf_addstr(&out, "Squashed commit of the following:\n");
407 while ((commit = get_revision(&rev)) != NULL) {
408 strbuf_addch(&out, '\n');
409 strbuf_addf(&out, "commit %s\n",
410 oid_to_hex(&commit->object.oid));
411 pretty_print_commit(&ctx, commit, &out);
412 }
413 write_file_buf(git_path_squash_msg(the_repository), out.buf, out.len);
414 strbuf_release(&out);
415}
416static void finish(struct commit *head_commit,
418 struct commit_list *remoteheads,
419 const struct object_id *new_head, const char *msg)
420{
421 struct strbuf reflog_message = STRBUF_INIT;
422 const struct object_id *head = &head_commit->object.oid;
423 if (!msg)
425 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
426 else {
427 if (verbosity >= 0)
428 printf("%s\n", msg);
429 strbuf_addf(&reflog_message, "%s: %s",
430 getenv("GIT_REFLOG_ACTION"), msg);
431 }
432 if (squash) {
433 squash_message(head_commit, remoteheads);
434 } else {
435 if (verbosity >= 0 && !merge_msg.len)
436 printf(_("No merge message -- not updating HEAD\n"));
437 else {
438 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
439 update_ref(reflog_message.buf, "HEAD", new_head, head,
440 0, UPDATE_REFS_DIE_ON_ERR);
441 /*
442 * We ignore errors in 'gc --auto', since the
443 * user should see them.
444 */
445 close_all_packs(the_repository->objects);
446 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
447 }
448 }
449 if (new_head && show_diffstat) {
450 struct diff_options opts;
451 repo_diff_setup(the_repository, &opts);
452 opts.stat_width = -1; /* use full terminal width */
453 opts.stat_graph_width = -1; /* respect statGraphWidth config */
454 opts.output_format |=
455 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
456 opts.detect_rename = DIFF_DETECT_RENAME;
457 diff_setup_done(&opts);
458 diff_tree_oid(head, new_head, "", &opts);
459 diffcore_std(&opts);
460 diff_flush(&opts);
461 }
462 /* Run a post-merge hook */
464 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
465 strbuf_release(&reflog_message);
467}
468/* Get the name for the merge commit's message. */
470static void merge_name(const char *remote, struct strbuf *msg)
471{
472 struct commit *remote_head;
473 struct object_id branch_head;
474 struct strbuf buf = STRBUF_INIT;
475 struct strbuf bname = STRBUF_INIT;
476 struct merge_remote_desc *desc;
477 const char *ptr;
478 char *found_ref;
479 int len, early;
480 strbuf_branchname(&bname, remote, 0);
482 remote = bname.buf;
483 oidclr(&branch_head);
485 remote_head = get_merge_parent(remote);
486 if (!remote_head)
487 die(_("'%s' does not point to a commit"), remote);
488 if (dwim_ref(remote, strlen(remote), &branch_head, &found_ref) > 0) {
490 if (starts_with(found_ref, "refs/heads/")) {
491 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
492 oid_to_hex(&branch_head), remote);
493 goto cleanup;
494 }
495 if (starts_with(found_ref, "refs/tags/")) {
496 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
497 oid_to_hex(&branch_head), remote);
498 goto cleanup;
499 }
500 if (starts_with(found_ref, "refs/remotes/")) {
501 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
502 oid_to_hex(&branch_head), remote);
503 goto cleanup;
504 }
505 }
506 /* See if remote matches <name>^^^.. or <name>~<number> */
508 for (len = 0, ptr = remote + strlen(remote);
509 remote < ptr && ptr[-1] == '^';
510 ptr--)
511 len++;
512 if (len)
513 early = 1;
514 else {
515 early = 0;
516 ptr = strrchr(remote, '~');
517 if (ptr) {
518 int seen_nonzero = 0;
519 len++; /* count ~ */
521 while (*++ptr && isdigit(*ptr)) {
522 seen_nonzero |= (*ptr != '0');
523 len++;
524 }
525 if (*ptr)
526 len = 0; /* not ...~<number> */
527 else if (seen_nonzero)
528 early = 1;
529 else if (len == 1)
530 early = 1; /* "name~" is "name~1"! */
531 }
532 }
533 if (len) {
534 struct strbuf truname = STRBUF_INIT;
535 strbuf_addf(&truname, "refs/heads/%s", remote);
536 strbuf_setlen(&truname, truname.len - len);
537 if (ref_exists(truname.buf)) {
538 strbuf_addf(msg,
539 "%s\t\tbranch '%s'%s of .\n",
540 oid_to_hex(&remote_head->object.oid),
541 truname.buf + 11,
542 (early ? " (early part)" : ""));
543 strbuf_release(&truname);
544 goto cleanup;
545 }
546 strbuf_release(&truname);
547 }
548 desc = merge_remote_util(remote_head);
550 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
551 strbuf_addf(msg, "%s\t\t%s '%s'\n",
552 oid_to_hex(&desc->obj->oid),
553 type_name(desc->obj->type),
554 remote);
555 goto cleanup;
556 }
557 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
559 oid_to_hex(&remote_head->object.oid), remote);
560cleanup:
561 strbuf_release(&buf);
562 strbuf_release(&bname);
563}
564static void parse_branch_merge_options(char *bmo)
566{
567 const char **argv;
568 int argc;
569 if (!bmo)
571 return;
572 argc = split_cmdline(bmo, &argv);
573 if (argc < 0)
574 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
575 _(split_cmdline_strerror(argc)));
576 REALLOC_ARRAY(argv, argc + 2);
577 MOVE_ARRAY(argv + 1, argv, argc + 1);
578 argc++;
579 argv[0] = "branch.*.mergeoptions";
580 parse_options(argc, argv, NULL, builtin_merge_options,
581 builtin_merge_usage, 0);
582 free(argv);
583}
584static int git_merge_config(const char *k, const char *v, void *cb)
586{
587 int status;
588 if (branch && starts_with(k, "branch.") &&
590 starts_with(k + 7, branch) &&
591 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
592 free(branch_mergeoptions);
593 branch_mergeoptions = xstrdup(v);
594 return 0;
595 }
596 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
598 show_diffstat = git_config_bool(k, v);
599 else if (!strcmp(k, "merge.verifysignatures"))
600 verify_signatures = git_config_bool(k, v);
601 else if (!strcmp(k, "pull.twohead"))
602 return git_config_string(&pull_twohead, k, v);
603 else if (!strcmp(k, "pull.octopus"))
604 return git_config_string(&pull_octopus, k, v);
605 else if (!strcmp(k, "merge.renormalize"))
606 option_renormalize = git_config_bool(k, v);
607 else if (!strcmp(k, "merge.ff")) {
608 int boolval = git_parse_maybe_bool(v);
609 if (0 <= boolval) {
610 fast_forward = boolval ? FF_ALLOW : FF_NO;
611 } else if (v && !strcmp(v, "only")) {
612 fast_forward = FF_ONLY;
613 } /* do not barf on values from future versions of git */
614 return 0;
615 } else if (!strcmp(k, "merge.defaulttoupstream")) {
616 default_to_upstream = git_config_bool(k, v);
617 return 0;
618 } else if (!strcmp(k, "commit.gpgsign")) {
619 sign_commit = git_config_bool(k, v) ? "" : NULL;
620 return 0;
621 }
622 status = fmt_merge_msg_config(k, v, cb);
624 if (status)
625 return status;
626 status = git_gpg_config(k, v, NULL);
627 if (status)
628 return status;
629 return git_diff_ui_config(k, v, cb);
630}
631static int read_tree_trivial(struct object_id *common, struct object_id *head,
633 struct object_id *one)
634{
635 int i, nr_trees = 0;
636 struct tree *trees[MAX_UNPACK_TREES];
637 struct tree_desc t[MAX_UNPACK_TREES];
638 struct unpack_trees_options opts;
639 memset(&opts, 0, sizeof(opts));
641 opts.head_idx = 2;
642 opts.src_index = &the_index;
643 opts.dst_index = &the_index;
644 opts.update = 1;
645 opts.verbose_update = 1;
646 opts.trivial_merges_only = 1;
647 opts.merge = 1;
648 trees[nr_trees] = parse_tree_indirect(common);
649 if (!trees[nr_trees++])
650 return -1;
651 trees[nr_trees] = parse_tree_indirect(head);
652 if (!trees[nr_trees++])
653 return -1;
654 trees[nr_trees] = parse_tree_indirect(one);
655 if (!trees[nr_trees++])
656 return -1;
657 opts.fn = threeway_merge;
658 cache_tree_free(&active_cache_tree);
659 for (i = 0; i < nr_trees; i++) {
660 parse_tree(trees[i]);
661 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
662 }
663 if (unpack_trees(nr_trees, t, &opts))
664 return -1;
665 return 0;
666}
667static void write_tree_trivial(struct object_id *oid)
669{
670 if (write_cache_as_tree(oid, 0, NULL))
671 die(_("git write-tree failed to write a tree"));
672}
673static int try_merge_strategy(const char *strategy, struct commit_list *common,
675 struct commit_list *remoteheads,
676 struct commit *head)
677{
678 struct lock_file lock = LOCK_INIT;
679 const char *head_arg = "HEAD";
680 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
682 refresh_cache(REFRESH_QUIET);
683 if (write_locked_index(&the_index, &lock,
684 COMMIT_LOCK | SKIP_IF_UNCHANGED))
685 return error(_("Unable to write index."));
686 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
688 int clean, x;
689 struct commit *result;
690 struct commit_list *reversed = NULL;
691 struct merge_options o;
692 struct commit_list *j;
693 if (remoteheads->next) {
695 error(_("Not handling anything other than two heads merge."));
696 return 2;
697 }
698 init_merge_options(&o, the_repository);
700 if (!strcmp(strategy, "subtree"))
701 o.subtree_shift = "";
702 o.renormalize = option_renormalize;
704 o.show_rename_progress =
705 show_progress == -1 ? isatty(2) : show_progress;
706 for (x = 0; x < xopts_nr; x++)
708 if (parse_merge_opt(&o, xopts[x]))
709 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
710 o.branch1 = head_arg;
712 o.branch2 = merge_remote_util(remoteheads->item)->name;
713 for (j = common; j; j = j->next)
715 commit_list_insert(j->item, &reversed);
716 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
718 clean = merge_recursive(&o, head,
719 remoteheads->item, reversed, &result);
720 if (clean < 0)
721 exit(128);
722 if (write_locked_index(&the_index, &lock,
723 COMMIT_LOCK | SKIP_IF_UNCHANGED))
724 die(_("unable to write %s"), get_index_file());
725 return clean ? 0 : 1;
726 } else {
727 return try_merge_command(the_repository,
728 strategy, xopts_nr, xopts,
729 common, head_arg, remoteheads);
730 }
731}
732static void count_diff_files(struct diff_queue_struct *q,
734 struct diff_options *opt, void *data)
735{
736 int *count = data;
737 (*count) += q->nr;
739}
740static int count_unmerged_entries(void)
742{
743 int i, ret = 0;
744 for (i = 0; i < active_nr; i++)
746 if (ce_stage(active_cache[i]))
747 ret++;
748 return ret;
750}
751static void add_strategies(const char *string, unsigned attr)
753{
754 int i;
755 if (string) {
757 struct string_list list = STRING_LIST_INIT_DUP;
758 struct string_list_item *item;
759 string_list_split(&list, string, ' ', -1);
760 for_each_string_list_item(item, &list)
761 append_strategy(get_strategy(item->string));
762 string_list_clear(&list, 0);
763 return;
764 }
765 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
766 if (all_strategy[i].attr & attr)
767 append_strategy(&all_strategy[i]);
768}
770static void read_merge_msg(struct strbuf *msg)
772{
773 const char *filename = git_path_merge_msg(the_repository);
774 strbuf_reset(msg);
775 if (strbuf_read_file(msg, filename, 0) < 0)
776 die_errno(_("Could not read from '%s'"), filename);
777}
778static void write_merge_state(struct commit_list *);
780static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
781{
782 if (err_msg)
783 error("%s", err_msg);
784 fprintf(stderr,
785 _("Not committing merge; use 'git commit' to complete the merge.\n"));
786 write_merge_state(remoteheads);
787 exit(1);
788}
789static const char merge_editor_comment[] =
791N_("Please enter a commit message to explain why this merge is necessary,\n"
792 "especially if it merges an updated upstream into a topic branch.\n"
793 "\n"
794 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
795 "the commit.\n");
796static void write_merge_heads(struct commit_list *);
798static void prepare_to_commit(struct commit_list *remoteheads)
799{
800 struct strbuf msg = STRBUF_INIT;
801 strbuf_addbuf(&msg, &merge_msg);
802 strbuf_addch(&msg, '\n');
803 if (squash)
804 BUG("the control must not reach here under --squash");
805 if (0 < option_edit)
806 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
807 if (signoff)
808 append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
809 write_merge_heads(remoteheads);
810 write_file_buf(git_path_merge_msg(the_repository), msg.buf, msg.len);
811 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
812 git_path_merge_msg(the_repository), "merge", NULL))
813 abort_commit(remoteheads, NULL);
814 if (0 < option_edit) {
815 if (launch_editor(git_path_merge_msg(the_repository), NULL, NULL))
816 abort_commit(remoteheads, NULL);
817 }
818 if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
820 "commit-msg",
821 git_path_merge_msg(the_repository), NULL))
822 abort_commit(remoteheads, NULL);
823 read_merge_msg(&msg);
825 strbuf_stripspace(&msg, 0 < option_edit);
826 if (!msg.len)
827 abort_commit(remoteheads, _("Empty commit message."));
828 strbuf_release(&merge_msg);
829 strbuf_addbuf(&merge_msg, &msg);
830 strbuf_release(&msg);
831}
832static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
834{
835 struct object_id result_tree, result_commit;
836 struct commit_list *parents, **pptr = &parents;
837 struct lock_file lock = LOCK_INIT;
838 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
840 refresh_cache(REFRESH_QUIET);
841 if (write_locked_index(&the_index, &lock,
842 COMMIT_LOCK | SKIP_IF_UNCHANGED))
843 return error(_("Unable to write index."));
844 write_tree_trivial(&result_tree);
846 printf(_("Wonderful.\n"));
847 pptr = commit_list_append(head, pptr);
848 pptr = commit_list_append(remoteheads->item, pptr);
849 prepare_to_commit(remoteheads);
850 if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
851 &result_commit, NULL, sign_commit))
852 die(_("failed to write commit object"));
853 finish(head, remoteheads, &result_commit, "In-index merge");
854 remove_merge_branch_state(the_repository);
855 return 0;
856}
857static int finish_automerge(struct commit *head,
859 int head_subsumed,
860 struct commit_list *common,
861 struct commit_list *remoteheads,
862 struct object_id *result_tree,
863 const char *wt_strategy)
864{
865 struct commit_list *parents = NULL;
866 struct strbuf buf = STRBUF_INIT;
867 struct object_id result_commit;
868 free_commit_list(common);
870 parents = remoteheads;
871 if (!head_subsumed || fast_forward == FF_NO)
872 commit_list_insert(head, &parents);
873 strbuf_addch(&merge_msg, '\n');
874 prepare_to_commit(remoteheads);
875 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
876 &result_commit, NULL, sign_commit))
877 die(_("failed to write commit object"));
878 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
879 finish(head, remoteheads, &result_commit, buf.buf);
880 strbuf_release(&buf);
881 remove_merge_branch_state(the_repository);
882 return 0;
883}
884static int suggest_conflicts(void)
886{
887 const char *filename;
888 FILE *fp;
889 struct strbuf msgbuf = STRBUF_INIT;
890 filename = git_path_merge_msg(the_repository);
892 fp = xfopen(filename, "a");
893 append_conflicts_hint(&the_index, &msgbuf);
895 fputs(msgbuf.buf, fp);
896 strbuf_release(&msgbuf);
897 fclose(fp);
898 repo_rerere(the_repository, allow_rerere_auto);
899 printf(_("Automatic merge failed; "
900 "fix conflicts and then commit the result.\n"));
901 return 1;
902}
903static int evaluate_result(void)
905{
906 int cnt = 0;
907 struct rev_info rev;
908 /* Check how many files differ. */
910 repo_init_revisions(the_repository, &rev, "");
911 setup_revisions(0, NULL, &rev, NULL);
912 rev.diffopt.output_format |=
913 DIFF_FORMAT_CALLBACK;
914 rev.diffopt.format_callback = count_diff_files;
915 rev.diffopt.format_callback_data = &cnt;
916 run_diff_files(&rev, 0);
917 /*
919 * Check how many unmerged entries are
920 * there.
921 */
922 cnt += count_unmerged_entries();
923 return cnt;
925}
926/*
928 * Pretend as if the user told us to merge with the remote-tracking
929 * branch we have for the upstream of the current branch
930 */
931static int setup_with_upstream(const char ***argv)
932{
933 struct branch *branch = branch_get(NULL);
934 int i;
935 const char **args;
936 if (!branch)
938 die(_("No current branch."));
939 if (!branch->remote_name)
940 die(_("No remote for the current branch."));
941 if (!branch->merge_nr)
942 die(_("No default upstream defined for the current branch."));
943 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
945 for (i = 0; i < branch->merge_nr; i++) {
946 if (!branch->merge[i]->dst)
947 die(_("No remote-tracking branch for %s from %s"),
948 branch->merge[i]->src, branch->remote_name);
949 args[i] = branch->merge[i]->dst;
950 }
951 args[i] = NULL;
952 *argv = args;
953 return i;
954}
955static void write_merge_heads(struct commit_list *remoteheads)
957{
958 struct commit_list *j;
959 struct strbuf buf = STRBUF_INIT;
960 for (j = remoteheads; j; j = j->next) {
962 struct object_id *oid;
963 struct commit *c = j->item;
964 struct merge_remote_desc *desc;
965 desc = merge_remote_util(c);
967 if (desc && desc->obj) {
968 oid = &desc->obj->oid;
969 } else {
970 oid = &c->object.oid;
971 }
972 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
973 }
974 write_file_buf(git_path_merge_head(the_repository), buf.buf, buf.len);
975 strbuf_reset(&buf);
977 if (fast_forward == FF_NO)
978 strbuf_addstr(&buf, "no-ff");
979 write_file_buf(git_path_merge_mode(the_repository), buf.buf, buf.len);
980 strbuf_release(&buf);
981}
982static void write_merge_state(struct commit_list *remoteheads)
984{
985 write_merge_heads(remoteheads);
986 strbuf_addch(&merge_msg, '\n');
987 write_file_buf(git_path_merge_msg(the_repository), merge_msg.buf,
988 merge_msg.len);
989}
990static int default_edit_option(void)
992{
993 static const char name[] = "GIT_MERGE_AUTOEDIT";
994 const char *e = getenv(name);
995 struct stat st_stdin, st_stdout;
996 if (have_message)
998 /* an explicit -m msg without --[no-]edit */
999 return 0;
1000 if (e) {
1002 int v = git_parse_maybe_bool(e);
1003 if (v < 0)
1004 die(_("Bad value '%s' in environment '%s'"), e, name);
1005 return v;
1006 }
1007 /* Use editor if stdin and stdout are the same and is a tty */
1009 return (!fstat(0, &st_stdin) &&
1010 !fstat(1, &st_stdout) &&
1011 isatty(0) && isatty(1) &&
1012 st_stdin.st_dev == st_stdout.st_dev &&
1013 st_stdin.st_ino == st_stdout.st_ino &&
1014 st_stdin.st_mode == st_stdout.st_mode);
1015}
1016static struct commit_list *reduce_parents(struct commit *head_commit,
1018 int *head_subsumed,
1019 struct commit_list *remoteheads)
1020{
1021 struct commit_list *parents, **remotes;
1022 /*
1024 * Is the current HEAD reachable from another commit being
1025 * merged? If so we do not want to record it as a parent of
1026 * the resulting merge, unless --no-ff is given. We will flip
1027 * this variable to 0 when we find HEAD among the independent
1028 * tips being merged.
1029 */
1030 *head_subsumed = 1;
1031 /* Find what parents to record by checking independent ones. */
1033 parents = reduce_heads(remoteheads);
1034 free_commit_list(remoteheads);
1035 remoteheads = NULL;
1037 remotes = &remoteheads;
1038 while (parents) {
1039 struct commit *commit = pop_commit(&parents);
1040 if (commit == head_commit)
1041 *head_subsumed = 0;
1042 else
1043 remotes = &commit_list_insert(commit, remotes)->next;
1044 }
1045 return remoteheads;
1046}
1047static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1049{
1050 struct fmt_merge_msg_opts opts;
1051 memset(&opts, 0, sizeof(opts));
1053 opts.add_title = !have_message;
1054 opts.shortlog_len = shortlog_len;
1055 opts.credit_people = (0 < option_edit);
1056 fmt_merge_msg(merge_names, merge_msg, &opts);
1058 if (merge_msg->len)
1059 strbuf_setlen(merge_msg, merge_msg->len - 1);
1060}
1061static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1063{
1064 const char *filename;
1065 int fd, pos, npos;
1066 struct strbuf fetch_head_file = STRBUF_INIT;
1067 const unsigned hexsz = the_hash_algo->hexsz;
1068 if (!merge_names)
1070 merge_names = &fetch_head_file;
1071 filename = git_path_fetch_head(the_repository);
1073 fd = open(filename, O_RDONLY);
1074 if (fd < 0)
1075 die_errno(_("could not open '%s' for reading"), filename);
1076 if (strbuf_read(merge_names, fd, 0) < 0)
1078 die_errno(_("could not read '%s'"), filename);
1079 if (close(fd) < 0)
1080 die_errno(_("could not close '%s'"), filename);
1081 for (pos = 0; pos < merge_names->len; pos = npos) {
1083 struct object_id oid;
1084 char *ptr;
1085 struct commit *commit;
1086 ptr = strchr(merge_names->buf + pos, '\n');
1088 if (ptr)
1089 npos = ptr - merge_names->buf + 1;
1090 else
1091 npos = merge_names->len;
1092 if (npos - pos < hexsz + 2 ||
1094 get_oid_hex(merge_names->buf + pos, &oid))
1095 commit = NULL; /* bad */
1096 else if (memcmp(merge_names->buf + pos + hexsz, "\t\t", 2))
1097 continue; /* not-for-merge */
1098 else {
1099 char saved = merge_names->buf[pos + hexsz];
1100 merge_names->buf[pos + hexsz] = '\0';
1101 commit = get_merge_parent(merge_names->buf + pos);
1102 merge_names->buf[pos + hexsz] = saved;
1103 }
1104 if (!commit) {
1105 if (ptr)
1106 *ptr = '\0';
1107 die(_("not something we can merge in %s: %s"),
1108 filename, merge_names->buf + pos);
1109 }
1110 remotes = &commit_list_insert(commit, remotes)->next;
1111 }
1112 if (merge_names == &fetch_head_file)
1114 strbuf_release(&fetch_head_file);
1115}
1116static struct commit_list *collect_parents(struct commit *head_commit,
1118 int *head_subsumed,
1119 int argc, const char **argv,
1120 struct strbuf *merge_msg)
1121{
1122 int i;
1123 struct commit_list *remoteheads = NULL;
1124 struct commit_list **remotes = &remoteheads;
1125 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1126 if (merge_msg && (!have_message || shortlog_len))
1128 autogen = &merge_names;
1129 if (head_commit)
1131 remotes = &commit_list_insert(head_commit, remotes)->next;
1132 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1134 handle_fetch_head(remotes, autogen);
1135 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1136 } else {
1137 for (i = 0; i < argc; i++) {
1138 struct commit *commit = get_merge_parent(argv[i]);
1139 if (!commit)
1140 help_unknown_ref(argv[i], "merge",
1141 _("not something we can merge"));
1142 remotes = &commit_list_insert(commit, remotes)->next;
1143 }
1144 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1145 if (autogen) {
1146 struct commit_list *p;
1147 for (p = remoteheads; p; p = p->next)
1148 merge_name(merge_remote_util(p->item)->name, autogen);
1149 }
1150 }
1151 if (autogen) {
1153 prepare_merge_message(autogen, merge_msg);
1154 strbuf_release(autogen);
1155 }
1156 return remoteheads;
1158}
1159static int merging_a_throwaway_tag(struct commit *commit)
1161{
1162 char *tag_ref;
1163 struct object_id oid;
1164 int is_throwaway_tag = 0;
1165 /* Are we merging a tag? */
1167 if (!merge_remote_util(commit) ||
1168 !merge_remote_util(commit)->obj ||
1169 merge_remote_util(commit)->obj->type != OBJ_TAG)
1170 return is_throwaway_tag;
1171 /*
1173 * Now we know we are merging a tag object. Are we downstream
1174 * and following the tags from upstream? If so, we must have
1175 * the tag object pointed at by "refs/tags/$T" where $T is the
1176 * tagname recorded in the tag object. We want to allow such
1177 * a "just to catch up" merge to fast-forward.
1178 *
1179 * Otherwise, we are playing an integrator's role, making a
1180 * merge with a throw-away tag from a contributor with
1181 * something like "git pull $contributor $signed_tag".
1182 * We want to forbid such a merge from fast-forwarding
1183 * by default; otherwise we would not keep the signature
1184 * anywhere.
1185 */
1186 tag_ref = xstrfmt("refs/tags/%s",
1187 ((struct tag *)merge_remote_util(commit)->obj)->tag);
1188 if (!read_ref(tag_ref, &oid) &&
1189 oideq(&oid, &merge_remote_util(commit)->obj->oid))
1190 is_throwaway_tag = 0;
1191 else
1192 is_throwaway_tag = 1;
1193 free(tag_ref);
1194 return is_throwaway_tag;
1195}
1196int cmd_merge(int argc, const char **argv, const char *prefix)
1198{
1199 struct object_id result_tree, stash, head_oid;
1200 struct commit *head_commit;
1201 struct strbuf buf = STRBUF_INIT;
1202 int i, ret = 0, head_subsumed;
1203 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1204 struct commit_list *common = NULL;
1205 const char *best_strategy = NULL, *wt_strategy = NULL;
1206 struct commit_list *remoteheads, *p;
1207 void *branch_to_free;
1208 int orig_argc = argc;
1209 if (argc == 2 && !strcmp(argv[1], "-h"))
1211 usage_with_options(builtin_merge_usage, builtin_merge_options);
1212 /*
1214 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1215 * current branch.
1216 */
1217 branch = branch_to_free = resolve_refdup("HEAD", 0, &head_oid, NULL);
1218 if (branch)
1219 skip_prefix(branch, "refs/heads/", &branch);
1220 init_diff_ui_defaults();
1222 git_config(git_merge_config, NULL);
1223 if (!branch || is_null_oid(&head_oid))
1225 head_commit = NULL;
1226 else
1227 head_commit = lookup_commit_or_die(&head_oid, "HEAD");
1228 if (branch_mergeoptions)
1230 parse_branch_merge_options(branch_mergeoptions);
1231 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1232 builtin_merge_usage, 0);
1233 if (shortlog_len < 0)
1234 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1235 if (verbosity < 0 && show_progress == -1)
1237 show_progress = 0;
1238 if (abort_current_merge) {
1240 int nargc = 2;
1241 const char *nargv[] = {"reset", "--merge", NULL};
1242 if (orig_argc != 2)
1244 usage_msg_opt(_("--abort expects no arguments"),
1245 builtin_merge_usage, builtin_merge_options);
1246 if (!file_exists(git_path_merge_head(the_repository)))
1248 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1249 /* Invoke 'git reset --merge' */
1251 ret = cmd_reset(nargc, nargv, prefix);
1252 goto done;
1253 }
1254 if (continue_current_merge) {
1256 int nargc = 1;
1257 const char *nargv[] = {"commit", NULL};
1258 if (orig_argc != 2)
1260 usage_msg_opt(_("--continue expects no arguments"),
1261 builtin_merge_usage, builtin_merge_options);
1262 if (!file_exists(git_path_merge_head(the_repository)))
1264 die(_("There is no merge in progress (MERGE_HEAD missing)."));
1265 /* Invoke 'git commit' */
1267 ret = cmd_commit(nargc, nargv, prefix);
1268 goto done;
1269 }
1270 if (read_cache_unmerged())
1272 die_resolve_conflict("merge");
1273 if (file_exists(git_path_merge_head(the_repository))) {
1275 /*
1276 * There is no unmerged entry, don't advise 'git
1277 * add/rm <file>', just 'git commit'.
1278 */
1279 if (advice_resolve_conflict)
1280 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1281 "Please, commit your changes before you merge."));
1282 else
1283 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1284 }
1285 if (file_exists(git_path_cherry_pick_head(the_repository))) {
1286 if (advice_resolve_conflict)
1287 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1288 "Please, commit your changes before you merge."));
1289 else
1290 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1291 }
1292 resolve_undo_clear();
1293 if (verbosity < 0)
1295 show_diffstat = 0;
1296 if (squash) {
1298 if (fast_forward == FF_NO)
1299 die(_("You cannot combine --squash with --no-ff."));
1300 option_commit = 0;
1301 }
1302 if (!argc) {
1304 if (default_to_upstream)
1305 argc = setup_with_upstream(&argv);
1306 else
1307 die(_("No commit specified and merge.defaultToUpstream not set."));
1308 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1309 argv[0] = "@{-1}";
1310 }
1311 if (!argc)
1313 usage_with_options(builtin_merge_usage,
1314 builtin_merge_options);
1315 if (!head_commit) {
1317 /*
1318 * If the merged head is a valid one there is no reason
1319 * to forbid "git merge" into a branch yet to be born.
1320 * We do the same for "git pull".
1321 */
1322 struct object_id *remote_head_oid;
1323 if (squash)
1324 die(_("Squash commit into empty head not supported yet"));
1325 if (fast_forward == FF_NO)
1326 die(_("Non-fast-forward commit does not make sense into "
1327 "an empty head"));
1328 remoteheads = collect_parents(head_commit, &head_subsumed,
1329 argc, argv, NULL);
1330 if (!remoteheads)
1331 die(_("%s - not something we can merge"), argv[0]);
1332 if (remoteheads->next)
1333 die(_("Can merge only exactly one commit into empty head"));
1334 if (verify_signatures)
1336 verify_merge_signature(remoteheads->item, verbosity);
1337 remote_head_oid = &remoteheads->item->object.oid;
1339 read_empty(remote_head_oid, 0);
1340 update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
1341 UPDATE_REFS_DIE_ON_ERR);
1342 goto done;
1343 }
1344 /*
1346 * All the rest are the commits being merged; prepare
1347 * the standard merge summary message to be appended
1348 * to the given message.
1349 */
1350 remoteheads = collect_parents(head_commit, &head_subsumed,
1351 argc, argv, &merge_msg);
1352 if (!head_commit || !argc)
1354 usage_with_options(builtin_merge_usage,
1355 builtin_merge_options);
1356 if (verify_signatures) {
1358 for (p = remoteheads; p; p = p->next) {
1359 verify_merge_signature(p->item, verbosity);
1360 }
1361 }
1362 strbuf_addstr(&buf, "merge");
1364 for (p = remoteheads; p; p = p->next)
1365 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1366 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1367 strbuf_reset(&buf);
1368 for (p = remoteheads; p; p = p->next) {
1370 struct commit *commit = p->item;
1371 strbuf_addf(&buf, "GITHEAD_%s",
1372 oid_to_hex(&commit->object.oid));
1373 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1374 strbuf_reset(&buf);
1375 if (fast_forward != FF_ONLY && merging_a_throwaway_tag(commit))
1376 fast_forward = FF_NO;
1377 }
1378 if (option_edit < 0)
1380 option_edit = default_edit_option();
1381 if (!use_strategies) {
1383 if (!remoteheads)
1384 ; /* already up-to-date */
1385 else if (!remoteheads->next)
1386 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1387 else
1388 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1389 }
1390 for (i = 0; i < use_strategies_nr; i++) {
1392 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1393 fast_forward = FF_NO;
1394 if (use_strategies[i]->attr & NO_TRIVIAL)
1395 allow_trivial = 0;
1396 }
1397 if (!remoteheads)
1399 ; /* already up-to-date */
1400 else if (!remoteheads->next)
1401 common = get_merge_bases(head_commit, remoteheads->item);
1402 else {
1403 struct commit_list *list = remoteheads;
1404 commit_list_insert(head_commit, &list);
1405 common = get_octopus_merge_bases(list);
1406 free(list);
1407 }
1408 update_ref("updating ORIG_HEAD", "ORIG_HEAD",
1410 &head_commit->object.oid, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1411 if (remoteheads && !common) {
1413 /* No common ancestors found. */
1414 if (!allow_unrelated_histories)
1415 die(_("refusing to merge unrelated histories"));
1416 /* otherwise, we need a real merge. */
1417 } else if (!remoteheads ||
1418 (!remoteheads->next && !common->next &&
1419 common->item == remoteheads->item)) {
1420 /*
1421 * If head can reach all the merge then we are up to date.
1422 * but first the most common case of merging one remote.
1423 */
1424 finish_up_to_date(_("Already up to date."));
1425 goto done;
1426 } else if (fast_forward != FF_NO && !remoteheads->next &&
1427 !common->next &&
1428 oideq(&common->item->object.oid, &head_commit->object.oid)) {
1429 /* Again the most common case of merging one remote. */
1430 struct strbuf msg = STRBUF_INIT;
1431 struct commit *commit;
1432 if (verbosity >= 0) {
1434 printf(_("Updating %s..%s\n"),
1435 find_unique_abbrev(&head_commit->object.oid,
1436 DEFAULT_ABBREV),
1437 find_unique_abbrev(&remoteheads->item->object.oid,
1438 DEFAULT_ABBREV));
1439 }
1440 strbuf_addstr(&msg, "Fast-forward");
1441 if (have_message)
1442 strbuf_addstr(&msg,
1443 " (no commit created; -m option ignored)");
1444 commit = remoteheads->item;
1445 if (!commit) {
1446 ret = 1;
1447 goto done;
1448 }
1449 if (checkout_fast_forward(the_repository,
1451 &head_commit->object.oid,
1452 &commit->object.oid,
1453 overwrite_ignore)) {
1454 ret = 1;
1455 goto done;
1456 }
1457 finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
1459 remove_merge_branch_state(the_repository);
1460 goto done;
1461 } else if (!remoteheads->next && common->next)
1462 ;
1463 /*
1464 * We are not doing octopus and not fast-forward. Need
1465 * a real merge.
1466 */
1467 else if (!remoteheads->next && !common->next && option_commit) {
1468 /*
1469 * We are not doing octopus, not fast-forward, and have
1470 * only one common.
1471 */
1472 refresh_cache(REFRESH_QUIET);
1473 if (allow_trivial && fast_forward != FF_ONLY) {
1474 /* See if it is really trivial. */
1475 git_committer_info(IDENT_STRICT);
1476 printf(_("Trying really trivial in-index merge...\n"));
1477 if (!read_tree_trivial(&common->item->object.oid,
1478 &head_commit->object.oid,
1479 &remoteheads->item->object.oid)) {
1480 ret = merge_trivial(head_commit, remoteheads);
1481 goto done;
1482 }
1483 printf(_("Nope.\n"));
1484 }
1485 } else {
1486 /*
1487 * An octopus. If we can reach all the remote we are up
1488 * to date.
1489 */
1490 int up_to_date = 1;
1491 struct commit_list *j;
1492 for (j = remoteheads; j; j = j->next) {
1494 struct commit_list *common_one;
1495 /*
1497 * Here we *have* to calculate the individual
1498 * merge_bases again, otherwise "git merge HEAD^
1499 * HEAD^^" would be missed.
1500 */
1501 common_one = get_merge_bases(head_commit, j->item);
1502 if (!oideq(&common_one->item->object.oid, &j->item->object.oid)) {
1503 up_to_date = 0;
1504 break;
1505 }
1506 }
1507 if (up_to_date) {
1508 finish_up_to_date(_("Already up to date. Yeeah!"));
1509 goto done;
1510 }
1511 }
1512 if (fast_forward == FF_ONLY)
1514 die(_("Not possible to fast-forward, aborting."));
1515 /* We are going to make a new commit. */
1517 git_committer_info(IDENT_STRICT);
1518 /*
1520 * At this point, we need a real merge. No matter what strategy
1521 * we use, it would operate on the index, possibly affecting the
1522 * working tree, and when resolved cleanly, have the desired
1523 * tree in the index -- this means that the index must be in
1524 * sync with the head commit. The strategies are responsible
1525 * to ensure this.
1526 */
1527 if (use_strategies_nr == 1 ||
1528 /*
1529 * Stash away the local changes so that we can try more than one.
1530 */
1531 save_state(&stash))
1532 oidclr(&stash);
1533 for (i = 0; i < use_strategies_nr; i++) {
1535 int ret;
1536 if (i) {
1537 printf(_("Rewinding the tree to pristine...\n"));
1538 restore_state(&head_commit->object.oid, &stash);
1539 }
1540 if (use_strategies_nr != 1)
1541 printf(_("Trying merge strategy %s...\n"),
1542 use_strategies[i]->name);
1543 /*
1544 * Remember which strategy left the state in the working
1545 * tree.
1546 */
1547 wt_strategy = use_strategies[i]->name;
1548 ret = try_merge_strategy(use_strategies[i]->name,
1550 common, remoteheads,
1551 head_commit);
1552 if (!option_commit && !ret) {
1553 merge_was_ok = 1;
1554 /*
1555 * This is necessary here just to avoid writing
1556 * the tree, but later we will *not* exit with
1557 * status code 1 because merge_was_ok is set.
1558 */
1559 ret = 1;
1560 }
1561 if (ret) {
1563 /*
1564 * The backend exits with 1 when conflicts are
1565 * left to be resolved, with 2 when it does not
1566 * handle the given merge at all.
1567 */
1568 if (ret == 1) {
1569 int cnt = evaluate_result();
1570 if (best_cnt <= 0 || cnt <= best_cnt) {
1572 best_strategy = use_strategies[i]->name;
1573 best_cnt = cnt;
1574 }
1575 }
1576 if (merge_was_ok)
1577 break;
1578 else
1579 continue;
1580 }
1581 /* Automerge succeeded. */
1583 write_tree_trivial(&result_tree);
1584 automerge_was_ok = 1;
1585 break;
1586 }
1587 /*
1589 * If we have a resulting tree, that means the strategy module
1590 * auto resolved the merge cleanly.
1591 */
1592 if (automerge_was_ok) {
1593 ret = finish_automerge(head_commit, head_subsumed,
1594 common, remoteheads,
1595 &result_tree, wt_strategy);
1596 goto done;
1597 }
1598 /*
1600 * Pick the result from the best strategy and have the user fix
1601 * it up.
1602 */
1603 if (!best_strategy) {
1604 restore_state(&head_commit->object.oid, &stash);
1605 if (use_strategies_nr > 1)
1606 fprintf(stderr,
1607 _("No merge strategy handled the merge.\n"));
1608 else
1609 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1610 use_strategies[0]->name);
1611 ret = 2;
1612 goto done;
1613 } else if (best_strategy == wt_strategy)
1614 ; /* We already have its result in the working tree. */
1615 else {
1616 printf(_("Rewinding the tree to pristine...\n"));
1617 restore_state(&head_commit->object.oid, &stash);
1618 printf(_("Using the %s to prepare resolving by hand.\n"),
1619 best_strategy);
1620 try_merge_strategy(best_strategy, common, remoteheads,
1621 head_commit);
1622 }
1623 if (squash)
1625 finish(head_commit, remoteheads, NULL, NULL);
1626 else
1627 write_merge_state(remoteheads);
1628 if (merge_was_ok)
1630 fprintf(stderr, _("Automatic merge went well; "
1631 "stopped before committing as requested\n"));
1632 else
1633 ret = suggest_conflicts();
1634done:
1636 free(branch_to_free);
1637 return ret;
1638}