Merge branch 'ag/userdiff-go-funcname'
[git/git.git] / builtin / merge.c
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
9 #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 "commit.h"
18 #include "diffcore.h"
19 #include "revision.h"
20 #include "unpack-trees.h"
21 #include "cache-tree.h"
22 #include "dir.h"
23 #include "utf8.h"
24 #include "log-tree.h"
25 #include "color.h"
26 #include "rerere.h"
27 #include "help.h"
28 #include "merge-recursive.h"
29 #include "resolve-undo.h"
30 #include "remote.h"
31 #include "fmt-merge-msg.h"
32 #include "gpg-interface.h"
33 #include "sequencer.h"
34 #include "string-list.h"
35 #include "packfile.h"
36 #include "tag.h"
37
38 #define DEFAULT_TWOHEAD (1<<0)
39 #define DEFAULT_OCTOPUS (1<<1)
40 #define NO_FAST_FORWARD (1<<2)
41 #define NO_TRIVIAL (1<<3)
42
43 struct strategy {
44 const char *name;
45 unsigned attr;
46 };
47
48 static const char * const builtin_merge_usage[] = {
49 N_("git merge [<options>] [<commit>...]"),
50 N_("git merge --abort"),
51 N_("git merge --continue"),
52 NULL
53 };
54
55 static int show_diffstat = 1, shortlog_len = -1, squash;
56 static int option_commit = 1;
57 static int option_edit = -1;
58 static int allow_trivial = 1, have_message, verify_signatures;
59 static int overwrite_ignore = 1;
60 static struct strbuf merge_msg = STRBUF_INIT;
61 static struct strategy **use_strategies;
62 static size_t use_strategies_nr, use_strategies_alloc;
63 static const char **xopts;
64 static size_t xopts_nr, xopts_alloc;
65 static const char *branch;
66 static char *branch_mergeoptions;
67 static int option_renormalize;
68 static int verbosity;
69 static int allow_rerere_auto;
70 static int abort_current_merge;
71 static int continue_current_merge;
72 static int allow_unrelated_histories;
73 static int show_progress = -1;
74 static int default_to_upstream = 1;
75 static int signoff;
76 static const char *sign_commit;
77 static int verify_msg = 1;
78
79 static struct strategy all_strategy[] = {
80 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
81 { "octopus", DEFAULT_OCTOPUS },
82 { "resolve", 0 },
83 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
84 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
85 };
86
87 static const char *pull_twohead, *pull_octopus;
88
89 enum ff_type {
90 FF_NO,
91 FF_ALLOW,
92 FF_ONLY
93 };
94
95 static enum ff_type fast_forward = FF_ALLOW;
96
97 static int option_parse_message(const struct option *opt,
98 const char *arg, int unset)
99 {
100 struct strbuf *buf = opt->value;
101
102 if (unset)
103 strbuf_setlen(buf, 0);
104 else if (arg) {
105 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
106 have_message = 1;
107 } else
108 return error(_("switch `m' requires a value"));
109 return 0;
110 }
111
112 static struct strategy *get_strategy(const char *name)
113 {
114 int i;
115 struct strategy *ret;
116 static struct cmdnames main_cmds, other_cmds;
117 static int loaded;
118
119 if (!name)
120 return NULL;
121
122 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
123 if (!strcmp(name, all_strategy[i].name))
124 return &all_strategy[i];
125
126 if (!loaded) {
127 struct cmdnames not_strategies;
128 loaded = 1;
129
130 memset(&not_strategies, 0, sizeof(struct cmdnames));
131 load_command_list("git-merge-", &main_cmds, &other_cmds);
132 for (i = 0; i < main_cmds.cnt; i++) {
133 int j, found = 0;
134 struct cmdname *ent = main_cmds.names[i];
135 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
136 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
137 && !all_strategy[j].name[ent->len])
138 found = 1;
139 if (!found)
140 add_cmdname(&not_strategies, ent->name, ent->len);
141 }
142 exclude_cmds(&main_cmds, &not_strategies);
143 }
144 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
145 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
146 fprintf(stderr, _("Available strategies are:"));
147 for (i = 0; i < main_cmds.cnt; i++)
148 fprintf(stderr, " %s", main_cmds.names[i]->name);
149 fprintf(stderr, ".\n");
150 if (other_cmds.cnt) {
151 fprintf(stderr, _("Available custom strategies are:"));
152 for (i = 0; i < other_cmds.cnt; i++)
153 fprintf(stderr, " %s", other_cmds.names[i]->name);
154 fprintf(stderr, ".\n");
155 }
156 exit(1);
157 }
158
159 ret = xcalloc(1, sizeof(struct strategy));
160 ret->name = xstrdup(name);
161 ret->attr = NO_TRIVIAL;
162 return ret;
163 }
164
165 static void append_strategy(struct strategy *s)
166 {
167 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
168 use_strategies[use_strategies_nr++] = s;
169 }
170
171 static int option_parse_strategy(const struct option *opt,
172 const char *name, int unset)
173 {
174 if (unset)
175 return 0;
176
177 append_strategy(get_strategy(name));
178 return 0;
179 }
180
181 static int option_parse_x(const struct option *opt,
182 const char *arg, int unset)
183 {
184 if (unset)
185 return 0;
186
187 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
188 xopts[xopts_nr++] = xstrdup(arg);
189 return 0;
190 }
191
192 static int option_parse_n(const struct option *opt,
193 const char *arg, int unset)
194 {
195 show_diffstat = unset;
196 return 0;
197 }
198
199 static struct option builtin_merge_options[] = {
200 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
201 N_("do not show a diffstat at the end of the merge"),
202 PARSE_OPT_NOARG, option_parse_n },
203 OPT_BOOL(0, "stat", &show_diffstat,
204 N_("show a diffstat at the end of the merge")),
205 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
206 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
207 N_("add (at most <n>) entries from shortlog to merge commit message"),
208 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
209 OPT_BOOL(0, "squash", &squash,
210 N_("create a single commit instead of doing a merge")),
211 OPT_BOOL(0, "commit", &option_commit,
212 N_("perform a commit if the merge succeeds (default)")),
213 OPT_BOOL('e', "edit", &option_edit,
214 N_("edit message before committing")),
215 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
216 { OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
217 N_("abort if fast-forward is not possible"),
218 PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
219 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
220 OPT_BOOL(0, "verify-signatures", &verify_signatures,
221 N_("verify that the named commit has a valid GPG signature")),
222 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
223 N_("merge strategy to use"), option_parse_strategy),
224 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
225 N_("option for selected merge strategy"), option_parse_x),
226 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
227 N_("merge commit message (for a non-fast-forward merge)"),
228 option_parse_message),
229 OPT__VERBOSITY(&verbosity),
230 OPT_BOOL(0, "abort", &abort_current_merge,
231 N_("abort the current in-progress merge")),
232 OPT_BOOL(0, "continue", &continue_current_merge,
233 N_("continue the current in-progress merge")),
234 OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
235 N_("allow merging unrelated histories")),
236 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
237 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
238 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
239 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
240 OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
241 OPT_BOOL(0, "verify", &verify_msg, N_("verify commit-msg hook")),
242 OPT_END()
243 };
244
245 /* Cleans up metadata that is uninteresting after a succeeded merge. */
246 static void drop_save(void)
247 {
248 unlink(git_path_merge_head());
249 unlink(git_path_merge_msg());
250 unlink(git_path_merge_mode());
251 }
252
253 static int save_state(struct object_id *stash)
254 {
255 int len;
256 struct child_process cp = CHILD_PROCESS_INIT;
257 struct strbuf buffer = STRBUF_INIT;
258 const char *argv[] = {"stash", "create", NULL};
259 int rc = -1;
260
261 cp.argv = argv;
262 cp.out = -1;
263 cp.git_cmd = 1;
264
265 if (start_command(&cp))
266 die(_("could not run stash."));
267 len = strbuf_read(&buffer, cp.out, 1024);
268 close(cp.out);
269
270 if (finish_command(&cp) || len < 0)
271 die(_("stash failed"));
272 else if (!len) /* no changes */
273 goto out;
274 strbuf_setlen(&buffer, buffer.len-1);
275 if (get_oid(buffer.buf, stash))
276 die(_("not a valid object: %s"), buffer.buf);
277 rc = 0;
278 out:
279 strbuf_release(&buffer);
280 return rc;
281 }
282
283 static void read_empty(unsigned const char *sha1, int verbose)
284 {
285 int i = 0;
286 const char *args[7];
287
288 args[i++] = "read-tree";
289 if (verbose)
290 args[i++] = "-v";
291 args[i++] = "-m";
292 args[i++] = "-u";
293 args[i++] = EMPTY_TREE_SHA1_HEX;
294 args[i++] = sha1_to_hex(sha1);
295 args[i] = NULL;
296
297 if (run_command_v_opt(args, RUN_GIT_CMD))
298 die(_("read-tree failed"));
299 }
300
301 static void reset_hard(unsigned const char *sha1, int verbose)
302 {
303 int i = 0;
304 const char *args[6];
305
306 args[i++] = "read-tree";
307 if (verbose)
308 args[i++] = "-v";
309 args[i++] = "--reset";
310 args[i++] = "-u";
311 args[i++] = sha1_to_hex(sha1);
312 args[i] = NULL;
313
314 if (run_command_v_opt(args, RUN_GIT_CMD))
315 die(_("read-tree failed"));
316 }
317
318 static void restore_state(const struct object_id *head,
319 const struct object_id *stash)
320 {
321 struct strbuf sb = STRBUF_INIT;
322 const char *args[] = { "stash", "apply", NULL, NULL };
323
324 if (is_null_oid(stash))
325 return;
326
327 reset_hard(head->hash, 1);
328
329 args[2] = oid_to_hex(stash);
330
331 /*
332 * It is OK to ignore error here, for example when there was
333 * nothing to restore.
334 */
335 run_command_v_opt(args, RUN_GIT_CMD);
336
337 strbuf_release(&sb);
338 refresh_cache(REFRESH_QUIET);
339 }
340
341 /* This is called when no merge was necessary. */
342 static void finish_up_to_date(const char *msg)
343 {
344 if (verbosity >= 0)
345 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
346 drop_save();
347 }
348
349 static void squash_message(struct commit *commit, struct commit_list *remoteheads)
350 {
351 struct rev_info rev;
352 struct strbuf out = STRBUF_INIT;
353 struct commit_list *j;
354 struct pretty_print_context ctx = {0};
355
356 printf(_("Squash commit -- not updating HEAD\n"));
357
358 init_revisions(&rev, NULL);
359 rev.ignore_merges = 1;
360 rev.commit_format = CMIT_FMT_MEDIUM;
361
362 commit->object.flags |= UNINTERESTING;
363 add_pending_object(&rev, &commit->object, NULL);
364
365 for (j = remoteheads; j; j = j->next)
366 add_pending_object(&rev, &j->item->object, NULL);
367
368 setup_revisions(0, NULL, &rev, NULL);
369 if (prepare_revision_walk(&rev))
370 die(_("revision walk setup failed"));
371
372 ctx.abbrev = rev.abbrev;
373 ctx.date_mode = rev.date_mode;
374 ctx.fmt = rev.commit_format;
375
376 strbuf_addstr(&out, "Squashed commit of the following:\n");
377 while ((commit = get_revision(&rev)) != NULL) {
378 strbuf_addch(&out, '\n');
379 strbuf_addf(&out, "commit %s\n",
380 oid_to_hex(&commit->object.oid));
381 pretty_print_commit(&ctx, commit, &out);
382 }
383 write_file_buf(git_path_squash_msg(), out.buf, out.len);
384 strbuf_release(&out);
385 }
386
387 static void finish(struct commit *head_commit,
388 struct commit_list *remoteheads,
389 const struct object_id *new_head, const char *msg)
390 {
391 struct strbuf reflog_message = STRBUF_INIT;
392 const struct object_id *head = &head_commit->object.oid;
393
394 if (!msg)
395 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
396 else {
397 if (verbosity >= 0)
398 printf("%s\n", msg);
399 strbuf_addf(&reflog_message, "%s: %s",
400 getenv("GIT_REFLOG_ACTION"), msg);
401 }
402 if (squash) {
403 squash_message(head_commit, remoteheads);
404 } else {
405 if (verbosity >= 0 && !merge_msg.len)
406 printf(_("No merge message -- not updating HEAD\n"));
407 else {
408 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
409 update_ref(reflog_message.buf, "HEAD", new_head, head,
410 0, UPDATE_REFS_DIE_ON_ERR);
411 /*
412 * We ignore errors in 'gc --auto', since the
413 * user should see them.
414 */
415 close_all_packs();
416 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
417 }
418 }
419 if (new_head && show_diffstat) {
420 struct diff_options opts;
421 diff_setup(&opts);
422 opts.stat_width = -1; /* use full terminal width */
423 opts.stat_graph_width = -1; /* respect statGraphWidth config */
424 opts.output_format |=
425 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
426 opts.detect_rename = DIFF_DETECT_RENAME;
427 diff_setup_done(&opts);
428 diff_tree_oid(head, new_head, "", &opts);
429 diffcore_std(&opts);
430 diff_flush(&opts);
431 }
432
433 /* Run a post-merge hook */
434 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
435
436 strbuf_release(&reflog_message);
437 }
438
439 /* Get the name for the merge commit's message. */
440 static void merge_name(const char *remote, struct strbuf *msg)
441 {
442 struct commit *remote_head;
443 struct object_id branch_head;
444 struct strbuf buf = STRBUF_INIT;
445 struct strbuf bname = STRBUF_INIT;
446 const char *ptr;
447 char *found_ref;
448 int len, early;
449
450 strbuf_branchname(&bname, remote, 0);
451 remote = bname.buf;
452
453 oidclr(&branch_head);
454 remote_head = get_merge_parent(remote);
455 if (!remote_head)
456 die(_("'%s' does not point to a commit"), remote);
457
458 if (dwim_ref(remote, strlen(remote), &branch_head, &found_ref) > 0) {
459 if (starts_with(found_ref, "refs/heads/")) {
460 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
461 oid_to_hex(&branch_head), remote);
462 goto cleanup;
463 }
464 if (starts_with(found_ref, "refs/tags/")) {
465 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
466 oid_to_hex(&branch_head), remote);
467 goto cleanup;
468 }
469 if (starts_with(found_ref, "refs/remotes/")) {
470 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
471 oid_to_hex(&branch_head), remote);
472 goto cleanup;
473 }
474 }
475
476 /* See if remote matches <name>^^^.. or <name>~<number> */
477 for (len = 0, ptr = remote + strlen(remote);
478 remote < ptr && ptr[-1] == '^';
479 ptr--)
480 len++;
481 if (len)
482 early = 1;
483 else {
484 early = 0;
485 ptr = strrchr(remote, '~');
486 if (ptr) {
487 int seen_nonzero = 0;
488
489 len++; /* count ~ */
490 while (*++ptr && isdigit(*ptr)) {
491 seen_nonzero |= (*ptr != '0');
492 len++;
493 }
494 if (*ptr)
495 len = 0; /* not ...~<number> */
496 else if (seen_nonzero)
497 early = 1;
498 else if (len == 1)
499 early = 1; /* "name~" is "name~1"! */
500 }
501 }
502 if (len) {
503 struct strbuf truname = STRBUF_INIT;
504 strbuf_addf(&truname, "refs/heads/%s", remote);
505 strbuf_setlen(&truname, truname.len - len);
506 if (ref_exists(truname.buf)) {
507 strbuf_addf(msg,
508 "%s\t\tbranch '%s'%s of .\n",
509 oid_to_hex(&remote_head->object.oid),
510 truname.buf + 11,
511 (early ? " (early part)" : ""));
512 strbuf_release(&truname);
513 goto cleanup;
514 }
515 strbuf_release(&truname);
516 }
517
518 if (remote_head->util) {
519 struct merge_remote_desc *desc;
520 desc = merge_remote_util(remote_head);
521 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
522 strbuf_addf(msg, "%s\t\t%s '%s'\n",
523 oid_to_hex(&desc->obj->oid),
524 type_name(desc->obj->type),
525 remote);
526 goto cleanup;
527 }
528 }
529
530 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
531 oid_to_hex(&remote_head->object.oid), remote);
532 cleanup:
533 strbuf_release(&buf);
534 strbuf_release(&bname);
535 }
536
537 static void parse_branch_merge_options(char *bmo)
538 {
539 const char **argv;
540 int argc;
541
542 if (!bmo)
543 return;
544 argc = split_cmdline(bmo, &argv);
545 if (argc < 0)
546 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
547 split_cmdline_strerror(argc));
548 REALLOC_ARRAY(argv, argc + 2);
549 MOVE_ARRAY(argv + 1, argv, argc + 1);
550 argc++;
551 argv[0] = "branch.*.mergeoptions";
552 parse_options(argc, argv, NULL, builtin_merge_options,
553 builtin_merge_usage, 0);
554 free(argv);
555 }
556
557 static int git_merge_config(const char *k, const char *v, void *cb)
558 {
559 int status;
560
561 if (branch && starts_with(k, "branch.") &&
562 starts_with(k + 7, branch) &&
563 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
564 free(branch_mergeoptions);
565 branch_mergeoptions = xstrdup(v);
566 return 0;
567 }
568
569 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
570 show_diffstat = git_config_bool(k, v);
571 else if (!strcmp(k, "merge.verifysignatures"))
572 verify_signatures = git_config_bool(k, v);
573 else if (!strcmp(k, "pull.twohead"))
574 return git_config_string(&pull_twohead, k, v);
575 else if (!strcmp(k, "pull.octopus"))
576 return git_config_string(&pull_octopus, k, v);
577 else if (!strcmp(k, "merge.renormalize"))
578 option_renormalize = git_config_bool(k, v);
579 else if (!strcmp(k, "merge.ff")) {
580 int boolval = git_parse_maybe_bool(v);
581 if (0 <= boolval) {
582 fast_forward = boolval ? FF_ALLOW : FF_NO;
583 } else if (v && !strcmp(v, "only")) {
584 fast_forward = FF_ONLY;
585 } /* do not barf on values from future versions of git */
586 return 0;
587 } else if (!strcmp(k, "merge.defaulttoupstream")) {
588 default_to_upstream = git_config_bool(k, v);
589 return 0;
590 } else if (!strcmp(k, "commit.gpgsign")) {
591 sign_commit = git_config_bool(k, v) ? "" : NULL;
592 return 0;
593 }
594
595 status = fmt_merge_msg_config(k, v, cb);
596 if (status)
597 return status;
598 status = git_gpg_config(k, v, NULL);
599 if (status)
600 return status;
601 return git_diff_ui_config(k, v, cb);
602 }
603
604 static int read_tree_trivial(struct object_id *common, struct object_id *head,
605 struct object_id *one)
606 {
607 int i, nr_trees = 0;
608 struct tree *trees[MAX_UNPACK_TREES];
609 struct tree_desc t[MAX_UNPACK_TREES];
610 struct unpack_trees_options opts;
611
612 memset(&opts, 0, sizeof(opts));
613 opts.head_idx = 2;
614 opts.src_index = &the_index;
615 opts.dst_index = &the_index;
616 opts.update = 1;
617 opts.verbose_update = 1;
618 opts.trivial_merges_only = 1;
619 opts.merge = 1;
620 trees[nr_trees] = parse_tree_indirect(common);
621 if (!trees[nr_trees++])
622 return -1;
623 trees[nr_trees] = parse_tree_indirect(head);
624 if (!trees[nr_trees++])
625 return -1;
626 trees[nr_trees] = parse_tree_indirect(one);
627 if (!trees[nr_trees++])
628 return -1;
629 opts.fn = threeway_merge;
630 cache_tree_free(&active_cache_tree);
631 for (i = 0; i < nr_trees; i++) {
632 parse_tree(trees[i]);
633 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
634 }
635 if (unpack_trees(nr_trees, t, &opts))
636 return -1;
637 return 0;
638 }
639
640 static void write_tree_trivial(struct object_id *oid)
641 {
642 if (write_cache_as_tree(oid->hash, 0, NULL))
643 die(_("git write-tree failed to write a tree"));
644 }
645
646 static int try_merge_strategy(const char *strategy, struct commit_list *common,
647 struct commit_list *remoteheads,
648 struct commit *head)
649 {
650 static struct lock_file lock;
651 const char *head_arg = "HEAD";
652
653 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
654 refresh_cache(REFRESH_QUIET);
655 if (active_cache_changed &&
656 write_locked_index(&the_index, &lock, COMMIT_LOCK))
657 return error(_("Unable to write index."));
658 rollback_lock_file(&lock);
659
660 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
661 int clean, x;
662 struct commit *result;
663 struct commit_list *reversed = NULL;
664 struct merge_options o;
665 struct commit_list *j;
666
667 if (remoteheads->next) {
668 error(_("Not handling anything other than two heads merge."));
669 return 2;
670 }
671
672 init_merge_options(&o);
673 if (!strcmp(strategy, "subtree"))
674 o.subtree_shift = "";
675
676 o.renormalize = option_renormalize;
677 o.show_rename_progress =
678 show_progress == -1 ? isatty(2) : show_progress;
679
680 for (x = 0; x < xopts_nr; x++)
681 if (parse_merge_opt(&o, xopts[x]))
682 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
683
684 o.branch1 = head_arg;
685 o.branch2 = merge_remote_util(remoteheads->item)->name;
686
687 for (j = common; j; j = j->next)
688 commit_list_insert(j->item, &reversed);
689
690 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
691 clean = merge_recursive(&o, head,
692 remoteheads->item, reversed, &result);
693 if (clean < 0)
694 exit(128);
695 if (active_cache_changed &&
696 write_locked_index(&the_index, &lock, COMMIT_LOCK))
697 die (_("unable to write %s"), get_index_file());
698 rollback_lock_file(&lock);
699 return clean ? 0 : 1;
700 } else {
701 return try_merge_command(strategy, xopts_nr, xopts,
702 common, head_arg, remoteheads);
703 }
704 }
705
706 static void count_diff_files(struct diff_queue_struct *q,
707 struct diff_options *opt, void *data)
708 {
709 int *count = data;
710
711 (*count) += q->nr;
712 }
713
714 static int count_unmerged_entries(void)
715 {
716 int i, ret = 0;
717
718 for (i = 0; i < active_nr; i++)
719 if (ce_stage(active_cache[i]))
720 ret++;
721
722 return ret;
723 }
724
725 static void add_strategies(const char *string, unsigned attr)
726 {
727 int i;
728
729 if (string) {
730 struct string_list list = STRING_LIST_INIT_DUP;
731 struct string_list_item *item;
732 string_list_split(&list, string, ' ', -1);
733 for_each_string_list_item(item, &list)
734 append_strategy(get_strategy(item->string));
735 string_list_clear(&list, 0);
736 return;
737 }
738 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
739 if (all_strategy[i].attr & attr)
740 append_strategy(&all_strategy[i]);
741
742 }
743
744 static void read_merge_msg(struct strbuf *msg)
745 {
746 const char *filename = git_path_merge_msg();
747 strbuf_reset(msg);
748 if (strbuf_read_file(msg, filename, 0) < 0)
749 die_errno(_("Could not read from '%s'"), filename);
750 }
751
752 static void write_merge_state(struct commit_list *);
753 static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
754 {
755 if (err_msg)
756 error("%s", err_msg);
757 fprintf(stderr,
758 _("Not committing merge; use 'git commit' to complete the merge.\n"));
759 write_merge_state(remoteheads);
760 exit(1);
761 }
762
763 static const char merge_editor_comment[] =
764 N_("Please enter a commit message to explain why this merge is necessary,\n"
765 "especially if it merges an updated upstream into a topic branch.\n"
766 "\n"
767 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
768 "the commit.\n");
769
770 static void write_merge_heads(struct commit_list *);
771 static void prepare_to_commit(struct commit_list *remoteheads)
772 {
773 struct strbuf msg = STRBUF_INIT;
774 strbuf_addbuf(&msg, &merge_msg);
775 strbuf_addch(&msg, '\n');
776 if (squash)
777 BUG("the control must not reach here under --squash");
778 if (0 < option_edit)
779 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
780 if (signoff)
781 append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
782 write_merge_heads(remoteheads);
783 write_file_buf(git_path_merge_msg(), msg.buf, msg.len);
784 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
785 git_path_merge_msg(), "merge", NULL))
786 abort_commit(remoteheads, NULL);
787 if (0 < option_edit) {
788 if (launch_editor(git_path_merge_msg(), NULL, NULL))
789 abort_commit(remoteheads, NULL);
790 }
791
792 if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
793 "commit-msg",
794 git_path_merge_msg(), NULL))
795 abort_commit(remoteheads, NULL);
796
797 read_merge_msg(&msg);
798 strbuf_stripspace(&msg, 0 < option_edit);
799 if (!msg.len)
800 abort_commit(remoteheads, _("Empty commit message."));
801 strbuf_release(&merge_msg);
802 strbuf_addbuf(&merge_msg, &msg);
803 strbuf_release(&msg);
804 }
805
806 static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
807 {
808 struct object_id result_tree, result_commit;
809 struct commit_list *parents, **pptr = &parents;
810 static struct lock_file lock;
811
812 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
813 refresh_cache(REFRESH_QUIET);
814 if (active_cache_changed &&
815 write_locked_index(&the_index, &lock, COMMIT_LOCK))
816 return error(_("Unable to write index."));
817 rollback_lock_file(&lock);
818
819 write_tree_trivial(&result_tree);
820 printf(_("Wonderful.\n"));
821 pptr = commit_list_append(head, pptr);
822 pptr = commit_list_append(remoteheads->item, pptr);
823 prepare_to_commit(remoteheads);
824 if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
825 &result_commit, NULL, sign_commit))
826 die(_("failed to write commit object"));
827 finish(head, remoteheads, &result_commit, "In-index merge");
828 drop_save();
829 return 0;
830 }
831
832 static int finish_automerge(struct commit *head,
833 int head_subsumed,
834 struct commit_list *common,
835 struct commit_list *remoteheads,
836 struct object_id *result_tree,
837 const char *wt_strategy)
838 {
839 struct commit_list *parents = NULL;
840 struct strbuf buf = STRBUF_INIT;
841 struct object_id result_commit;
842
843 free_commit_list(common);
844 parents = remoteheads;
845 if (!head_subsumed || fast_forward == FF_NO)
846 commit_list_insert(head, &parents);
847 strbuf_addch(&merge_msg, '\n');
848 prepare_to_commit(remoteheads);
849 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
850 &result_commit, NULL, sign_commit))
851 die(_("failed to write commit object"));
852 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
853 finish(head, remoteheads, &result_commit, buf.buf);
854 strbuf_release(&buf);
855 drop_save();
856 return 0;
857 }
858
859 static int suggest_conflicts(void)
860 {
861 const char *filename;
862 FILE *fp;
863 struct strbuf msgbuf = STRBUF_INIT;
864
865 filename = git_path_merge_msg();
866 fp = xfopen(filename, "a");
867
868 append_conflicts_hint(&msgbuf);
869 fputs(msgbuf.buf, fp);
870 strbuf_release(&msgbuf);
871 fclose(fp);
872 rerere(allow_rerere_auto);
873 printf(_("Automatic merge failed; "
874 "fix conflicts and then commit the result.\n"));
875 return 1;
876 }
877
878 static int evaluate_result(void)
879 {
880 int cnt = 0;
881 struct rev_info rev;
882
883 /* Check how many files differ. */
884 init_revisions(&rev, "");
885 setup_revisions(0, NULL, &rev, NULL);
886 rev.diffopt.output_format |=
887 DIFF_FORMAT_CALLBACK;
888 rev.diffopt.format_callback = count_diff_files;
889 rev.diffopt.format_callback_data = &cnt;
890 run_diff_files(&rev, 0);
891
892 /*
893 * Check how many unmerged entries are
894 * there.
895 */
896 cnt += count_unmerged_entries();
897
898 return cnt;
899 }
900
901 /*
902 * Pretend as if the user told us to merge with the remote-tracking
903 * branch we have for the upstream of the current branch
904 */
905 static int setup_with_upstream(const char ***argv)
906 {
907 struct branch *branch = branch_get(NULL);
908 int i;
909 const char **args;
910
911 if (!branch)
912 die(_("No current branch."));
913 if (!branch->remote_name)
914 die(_("No remote for the current branch."));
915 if (!branch->merge_nr)
916 die(_("No default upstream defined for the current branch."));
917
918 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
919 for (i = 0; i < branch->merge_nr; i++) {
920 if (!branch->merge[i]->dst)
921 die(_("No remote-tracking branch for %s from %s"),
922 branch->merge[i]->src, branch->remote_name);
923 args[i] = branch->merge[i]->dst;
924 }
925 args[i] = NULL;
926 *argv = args;
927 return i;
928 }
929
930 static void write_merge_heads(struct commit_list *remoteheads)
931 {
932 struct commit_list *j;
933 struct strbuf buf = STRBUF_INIT;
934
935 for (j = remoteheads; j; j = j->next) {
936 struct object_id *oid;
937 struct commit *c = j->item;
938 if (c->util && merge_remote_util(c)->obj) {
939 oid = &merge_remote_util(c)->obj->oid;
940 } else {
941 oid = &c->object.oid;
942 }
943 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
944 }
945 write_file_buf(git_path_merge_head(), buf.buf, buf.len);
946
947 strbuf_reset(&buf);
948 if (fast_forward == FF_NO)
949 strbuf_addstr(&buf, "no-ff");
950 write_file_buf(git_path_merge_mode(), buf.buf, buf.len);
951 strbuf_release(&buf);
952 }
953
954 static void write_merge_state(struct commit_list *remoteheads)
955 {
956 write_merge_heads(remoteheads);
957 strbuf_addch(&merge_msg, '\n');
958 write_file_buf(git_path_merge_msg(), merge_msg.buf, merge_msg.len);
959 }
960
961 static int default_edit_option(void)
962 {
963 static const char name[] = "GIT_MERGE_AUTOEDIT";
964 const char *e = getenv(name);
965 struct stat st_stdin, st_stdout;
966
967 if (have_message)
968 /* an explicit -m msg without --[no-]edit */
969 return 0;
970
971 if (e) {
972 int v = git_parse_maybe_bool(e);
973 if (v < 0)
974 die(_("Bad value '%s' in environment '%s'"), e, name);
975 return v;
976 }
977
978 /* Use editor if stdin and stdout are the same and is a tty */
979 return (!fstat(0, &st_stdin) &&
980 !fstat(1, &st_stdout) &&
981 isatty(0) && isatty(1) &&
982 st_stdin.st_dev == st_stdout.st_dev &&
983 st_stdin.st_ino == st_stdout.st_ino &&
984 st_stdin.st_mode == st_stdout.st_mode);
985 }
986
987 static struct commit_list *reduce_parents(struct commit *head_commit,
988 int *head_subsumed,
989 struct commit_list *remoteheads)
990 {
991 struct commit_list *parents, **remotes;
992
993 /*
994 * Is the current HEAD reachable from another commit being
995 * merged? If so we do not want to record it as a parent of
996 * the resulting merge, unless --no-ff is given. We will flip
997 * this variable to 0 when we find HEAD among the independent
998 * tips being merged.
999 */
1000 *head_subsumed = 1;
1001
1002 /* Find what parents to record by checking independent ones. */
1003 parents = reduce_heads(remoteheads);
1004 free_commit_list(remoteheads);
1005
1006 remoteheads = NULL;
1007 remotes = &remoteheads;
1008 while (parents) {
1009 struct commit *commit = pop_commit(&parents);
1010 if (commit == head_commit)
1011 *head_subsumed = 0;
1012 else
1013 remotes = &commit_list_insert(commit, remotes)->next;
1014 }
1015 return remoteheads;
1016 }
1017
1018 static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1019 {
1020 struct fmt_merge_msg_opts opts;
1021
1022 memset(&opts, 0, sizeof(opts));
1023 opts.add_title = !have_message;
1024 opts.shortlog_len = shortlog_len;
1025 opts.credit_people = (0 < option_edit);
1026
1027 fmt_merge_msg(merge_names, merge_msg, &opts);
1028 if (merge_msg->len)
1029 strbuf_setlen(merge_msg, merge_msg->len - 1);
1030 }
1031
1032 static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1033 {
1034 const char *filename;
1035 int fd, pos, npos;
1036 struct strbuf fetch_head_file = STRBUF_INIT;
1037
1038 if (!merge_names)
1039 merge_names = &fetch_head_file;
1040
1041 filename = git_path_fetch_head();
1042 fd = open(filename, O_RDONLY);
1043 if (fd < 0)
1044 die_errno(_("could not open '%s' for reading"), filename);
1045
1046 if (strbuf_read(merge_names, fd, 0) < 0)
1047 die_errno(_("could not read '%s'"), filename);
1048 if (close(fd) < 0)
1049 die_errno(_("could not close '%s'"), filename);
1050
1051 for (pos = 0; pos < merge_names->len; pos = npos) {
1052 struct object_id oid;
1053 char *ptr;
1054 struct commit *commit;
1055
1056 ptr = strchr(merge_names->buf + pos, '\n');
1057 if (ptr)
1058 npos = ptr - merge_names->buf + 1;
1059 else
1060 npos = merge_names->len;
1061
1062 if (npos - pos < GIT_SHA1_HEXSZ + 2 ||
1063 get_oid_hex(merge_names->buf + pos, &oid))
1064 commit = NULL; /* bad */
1065 else if (memcmp(merge_names->buf + pos + GIT_SHA1_HEXSZ, "\t\t", 2))
1066 continue; /* not-for-merge */
1067 else {
1068 char saved = merge_names->buf[pos + GIT_SHA1_HEXSZ];
1069 merge_names->buf[pos + GIT_SHA1_HEXSZ] = '\0';
1070 commit = get_merge_parent(merge_names->buf + pos);
1071 merge_names->buf[pos + GIT_SHA1_HEXSZ] = saved;
1072 }
1073 if (!commit) {
1074 if (ptr)
1075 *ptr = '\0';
1076 die(_("not something we can merge in %s: %s"),
1077 filename, merge_names->buf + pos);
1078 }
1079 remotes = &commit_list_insert(commit, remotes)->next;
1080 }
1081
1082 if (merge_names == &fetch_head_file)
1083 strbuf_release(&fetch_head_file);
1084 }
1085
1086 static struct commit_list *collect_parents(struct commit *head_commit,
1087 int *head_subsumed,
1088 int argc, const char **argv,
1089 struct strbuf *merge_msg)
1090 {
1091 int i;
1092 struct commit_list *remoteheads = NULL;
1093 struct commit_list **remotes = &remoteheads;
1094 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1095
1096 if (merge_msg && (!have_message || shortlog_len))
1097 autogen = &merge_names;
1098
1099 if (head_commit)
1100 remotes = &commit_list_insert(head_commit, remotes)->next;
1101
1102 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1103 handle_fetch_head(remotes, autogen);
1104 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1105 } else {
1106 for (i = 0; i < argc; i++) {
1107 struct commit *commit = get_merge_parent(argv[i]);
1108 if (!commit)
1109 help_unknown_ref(argv[i], "merge",
1110 _("not something we can merge"));
1111 remotes = &commit_list_insert(commit, remotes)->next;
1112 }
1113 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1114 if (autogen) {
1115 struct commit_list *p;
1116 for (p = remoteheads; p; p = p->next)
1117 merge_name(merge_remote_util(p->item)->name, autogen);
1118 }
1119 }
1120
1121 if (autogen) {
1122 prepare_merge_message(autogen, merge_msg);
1123 strbuf_release(autogen);
1124 }
1125
1126 return remoteheads;
1127 }
1128
1129 static int merging_a_throwaway_tag(struct commit *commit)
1130 {
1131 char *tag_ref;
1132 struct object_id oid;
1133 int is_throwaway_tag = 0;
1134
1135 /* Are we merging a tag? */
1136 if (!merge_remote_util(commit) ||
1137 !merge_remote_util(commit)->obj ||
1138 merge_remote_util(commit)->obj->type != OBJ_TAG)
1139 return is_throwaway_tag;
1140
1141 /*
1142 * Now we know we are merging a tag object. Are we downstream
1143 * and following the tags from upstream? If so, we must have
1144 * the tag object pointed at by "refs/tags/$T" where $T is the
1145 * tagname recorded in the tag object. We want to allow such
1146 * a "just to catch up" merge to fast-forward.
1147 *
1148 * Otherwise, we are playing an integrator's role, making a
1149 * merge with a throw-away tag from a contributor with
1150 * something like "git pull $contributor $signed_tag".
1151 * We want to forbid such a merge from fast-forwarding
1152 * by default; otherwise we would not keep the signature
1153 * anywhere.
1154 */
1155 tag_ref = xstrfmt("refs/tags/%s",
1156 ((struct tag *)merge_remote_util(commit)->obj)->tag);
1157 if (!read_ref(tag_ref, &oid) &&
1158 !oidcmp(&oid, &merge_remote_util(commit)->obj->oid))
1159 is_throwaway_tag = 0;
1160 else
1161 is_throwaway_tag = 1;
1162 free(tag_ref);
1163 return is_throwaway_tag;
1164 }
1165
1166 int cmd_merge(int argc, const char **argv, const char *prefix)
1167 {
1168 struct object_id result_tree, stash, head_oid;
1169 struct commit *head_commit;
1170 struct strbuf buf = STRBUF_INIT;
1171 int i, ret = 0, head_subsumed;
1172 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1173 struct commit_list *common = NULL;
1174 const char *best_strategy = NULL, *wt_strategy = NULL;
1175 struct commit_list *remoteheads, *p;
1176 void *branch_to_free;
1177 int orig_argc = argc;
1178
1179 if (argc == 2 && !strcmp(argv[1], "-h"))
1180 usage_with_options(builtin_merge_usage, builtin_merge_options);
1181
1182 /*
1183 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1184 * current branch.
1185 */
1186 branch = branch_to_free = resolve_refdup("HEAD", 0, &head_oid, NULL);
1187 if (branch)
1188 skip_prefix(branch, "refs/heads/", &branch);
1189 if (!branch || is_null_oid(&head_oid))
1190 head_commit = NULL;
1191 else
1192 head_commit = lookup_commit_or_die(&head_oid, "HEAD");
1193
1194 init_diff_ui_defaults();
1195 git_config(git_merge_config, NULL);
1196
1197 if (branch_mergeoptions)
1198 parse_branch_merge_options(branch_mergeoptions);
1199 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1200 builtin_merge_usage, 0);
1201 if (shortlog_len < 0)
1202 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1203
1204 if (verbosity < 0 && show_progress == -1)
1205 show_progress = 0;
1206
1207 if (abort_current_merge) {
1208 int nargc = 2;
1209 const char *nargv[] = {"reset", "--merge", NULL};
1210
1211 if (orig_argc != 2)
1212 usage_msg_opt(_("--abort expects no arguments"),
1213 builtin_merge_usage, builtin_merge_options);
1214
1215 if (!file_exists(git_path_merge_head()))
1216 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1217
1218 /* Invoke 'git reset --merge' */
1219 ret = cmd_reset(nargc, nargv, prefix);
1220 goto done;
1221 }
1222
1223 if (continue_current_merge) {
1224 int nargc = 1;
1225 const char *nargv[] = {"commit", NULL};
1226
1227 if (orig_argc != 2)
1228 usage_msg_opt(_("--continue expects no arguments"),
1229 builtin_merge_usage, builtin_merge_options);
1230
1231 if (!file_exists(git_path_merge_head()))
1232 die(_("There is no merge in progress (MERGE_HEAD missing)."));
1233
1234 /* Invoke 'git commit' */
1235 ret = cmd_commit(nargc, nargv, prefix);
1236 goto done;
1237 }
1238
1239 if (read_cache_unmerged())
1240 die_resolve_conflict("merge");
1241
1242 if (file_exists(git_path_merge_head())) {
1243 /*
1244 * There is no unmerged entry, don't advise 'git
1245 * add/rm <file>', just 'git commit'.
1246 */
1247 if (advice_resolve_conflict)
1248 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1249 "Please, commit your changes before you merge."));
1250 else
1251 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1252 }
1253 if (file_exists(git_path_cherry_pick_head())) {
1254 if (advice_resolve_conflict)
1255 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1256 "Please, commit your changes before you merge."));
1257 else
1258 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1259 }
1260 resolve_undo_clear();
1261
1262 if (verbosity < 0)
1263 show_diffstat = 0;
1264
1265 if (squash) {
1266 if (fast_forward == FF_NO)
1267 die(_("You cannot combine --squash with --no-ff."));
1268 option_commit = 0;
1269 }
1270
1271 if (!argc) {
1272 if (default_to_upstream)
1273 argc = setup_with_upstream(&argv);
1274 else
1275 die(_("No commit specified and merge.defaultToUpstream not set."));
1276 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1277 argv[0] = "@{-1}";
1278 }
1279
1280 if (!argc)
1281 usage_with_options(builtin_merge_usage,
1282 builtin_merge_options);
1283
1284 if (!head_commit) {
1285 /*
1286 * If the merged head is a valid one there is no reason
1287 * to forbid "git merge" into a branch yet to be born.
1288 * We do the same for "git pull".
1289 */
1290 struct object_id *remote_head_oid;
1291 if (squash)
1292 die(_("Squash commit into empty head not supported yet"));
1293 if (fast_forward == FF_NO)
1294 die(_("Non-fast-forward commit does not make sense into "
1295 "an empty head"));
1296 remoteheads = collect_parents(head_commit, &head_subsumed,
1297 argc, argv, NULL);
1298 if (!remoteheads)
1299 die(_("%s - not something we can merge"), argv[0]);
1300 if (remoteheads->next)
1301 die(_("Can merge only exactly one commit into empty head"));
1302 remote_head_oid = &remoteheads->item->object.oid;
1303 read_empty(remote_head_oid->hash, 0);
1304 update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
1305 UPDATE_REFS_DIE_ON_ERR);
1306 goto done;
1307 }
1308
1309 /*
1310 * All the rest are the commits being merged; prepare
1311 * the standard merge summary message to be appended
1312 * to the given message.
1313 */
1314 remoteheads = collect_parents(head_commit, &head_subsumed,
1315 argc, argv, &merge_msg);
1316
1317 if (!head_commit || !argc)
1318 usage_with_options(builtin_merge_usage,
1319 builtin_merge_options);
1320
1321 if (verify_signatures) {
1322 for (p = remoteheads; p; p = p->next) {
1323 struct commit *commit = p->item;
1324 char hex[GIT_MAX_HEXSZ + 1];
1325 struct signature_check signature_check;
1326 memset(&signature_check, 0, sizeof(signature_check));
1327
1328 check_commit_signature(commit, &signature_check);
1329
1330 find_unique_abbrev_r(hex, commit->object.oid.hash, DEFAULT_ABBREV);
1331 switch (signature_check.result) {
1332 case 'G':
1333 break;
1334 case 'U':
1335 die(_("Commit %s has an untrusted GPG signature, "
1336 "allegedly by %s."), hex, signature_check.signer);
1337 case 'B':
1338 die(_("Commit %s has a bad GPG signature "
1339 "allegedly by %s."), hex, signature_check.signer);
1340 default: /* 'N' */
1341 die(_("Commit %s does not have a GPG signature."), hex);
1342 }
1343 if (verbosity >= 0 && signature_check.result == 'G')
1344 printf(_("Commit %s has a good GPG signature by %s\n"),
1345 hex, signature_check.signer);
1346
1347 signature_check_clear(&signature_check);
1348 }
1349 }
1350
1351 strbuf_addstr(&buf, "merge");
1352 for (p = remoteheads; p; p = p->next)
1353 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1354 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1355 strbuf_reset(&buf);
1356
1357 for (p = remoteheads; p; p = p->next) {
1358 struct commit *commit = p->item;
1359 strbuf_addf(&buf, "GITHEAD_%s",
1360 oid_to_hex(&commit->object.oid));
1361 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1362 strbuf_reset(&buf);
1363 if (fast_forward != FF_ONLY && merging_a_throwaway_tag(commit))
1364 fast_forward = FF_NO;
1365 }
1366
1367 if (option_edit < 0)
1368 option_edit = default_edit_option();
1369
1370 if (!use_strategies) {
1371 if (!remoteheads)
1372 ; /* already up-to-date */
1373 else if (!remoteheads->next)
1374 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1375 else
1376 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1377 }
1378
1379 for (i = 0; i < use_strategies_nr; i++) {
1380 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1381 fast_forward = FF_NO;
1382 if (use_strategies[i]->attr & NO_TRIVIAL)
1383 allow_trivial = 0;
1384 }
1385
1386 if (!remoteheads)
1387 ; /* already up-to-date */
1388 else if (!remoteheads->next)
1389 common = get_merge_bases(head_commit, remoteheads->item);
1390 else {
1391 struct commit_list *list = remoteheads;
1392 commit_list_insert(head_commit, &list);
1393 common = get_octopus_merge_bases(list);
1394 free(list);
1395 }
1396
1397 update_ref("updating ORIG_HEAD", "ORIG_HEAD",
1398 &head_commit->object.oid, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1399
1400 if (remoteheads && !common) {
1401 /* No common ancestors found. */
1402 if (!allow_unrelated_histories)
1403 die(_("refusing to merge unrelated histories"));
1404 /* otherwise, we need a real merge. */
1405 } else if (!remoteheads ||
1406 (!remoteheads->next && !common->next &&
1407 common->item == remoteheads->item)) {
1408 /*
1409 * If head can reach all the merge then we are up to date.
1410 * but first the most common case of merging one remote.
1411 */
1412 finish_up_to_date(_("Already up to date."));
1413 goto done;
1414 } else if (fast_forward != FF_NO && !remoteheads->next &&
1415 !common->next &&
1416 !oidcmp(&common->item->object.oid, &head_commit->object.oid)) {
1417 /* Again the most common case of merging one remote. */
1418 struct strbuf msg = STRBUF_INIT;
1419 struct commit *commit;
1420
1421 if (verbosity >= 0) {
1422 printf(_("Updating %s..%s\n"),
1423 find_unique_abbrev(head_commit->object.oid.hash,
1424 DEFAULT_ABBREV),
1425 find_unique_abbrev(remoteheads->item->object.oid.hash,
1426 DEFAULT_ABBREV));
1427 }
1428 strbuf_addstr(&msg, "Fast-forward");
1429 if (have_message)
1430 strbuf_addstr(&msg,
1431 " (no commit created; -m option ignored)");
1432 commit = remoteheads->item;
1433 if (!commit) {
1434 ret = 1;
1435 goto done;
1436 }
1437
1438 if (checkout_fast_forward(&head_commit->object.oid,
1439 &commit->object.oid,
1440 overwrite_ignore)) {
1441 ret = 1;
1442 goto done;
1443 }
1444
1445 finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
1446 drop_save();
1447 goto done;
1448 } else if (!remoteheads->next && common->next)
1449 ;
1450 /*
1451 * We are not doing octopus and not fast-forward. Need
1452 * a real merge.
1453 */
1454 else if (!remoteheads->next && !common->next && option_commit) {
1455 /*
1456 * We are not doing octopus, not fast-forward, and have
1457 * only one common.
1458 */
1459 refresh_cache(REFRESH_QUIET);
1460 if (allow_trivial && fast_forward != FF_ONLY) {
1461 /* See if it is really trivial. */
1462 git_committer_info(IDENT_STRICT);
1463 printf(_("Trying really trivial in-index merge...\n"));
1464 if (!read_tree_trivial(&common->item->object.oid,
1465 &head_commit->object.oid,
1466 &remoteheads->item->object.oid)) {
1467 ret = merge_trivial(head_commit, remoteheads);
1468 goto done;
1469 }
1470 printf(_("Nope.\n"));
1471 }
1472 } else {
1473 /*
1474 * An octopus. If we can reach all the remote we are up
1475 * to date.
1476 */
1477 int up_to_date = 1;
1478 struct commit_list *j;
1479
1480 for (j = remoteheads; j; j = j->next) {
1481 struct commit_list *common_one;
1482
1483 /*
1484 * Here we *have* to calculate the individual
1485 * merge_bases again, otherwise "git merge HEAD^
1486 * HEAD^^" would be missed.
1487 */
1488 common_one = get_merge_bases(head_commit, j->item);
1489 if (oidcmp(&common_one->item->object.oid, &j->item->object.oid)) {
1490 up_to_date = 0;
1491 break;
1492 }
1493 }
1494 if (up_to_date) {
1495 finish_up_to_date(_("Already up to date. Yeeah!"));
1496 goto done;
1497 }
1498 }
1499
1500 if (fast_forward == FF_ONLY)
1501 die(_("Not possible to fast-forward, aborting."));
1502
1503 /* We are going to make a new commit. */
1504 git_committer_info(IDENT_STRICT);
1505
1506 /*
1507 * At this point, we need a real merge. No matter what strategy
1508 * we use, it would operate on the index, possibly affecting the
1509 * working tree, and when resolved cleanly, have the desired
1510 * tree in the index -- this means that the index must be in
1511 * sync with the head commit. The strategies are responsible
1512 * to ensure this.
1513 */
1514 if (use_strategies_nr == 1 ||
1515 /*
1516 * Stash away the local changes so that we can try more than one.
1517 */
1518 save_state(&stash))
1519 oidclr(&stash);
1520
1521 for (i = 0; i < use_strategies_nr; i++) {
1522 int ret;
1523 if (i) {
1524 printf(_("Rewinding the tree to pristine...\n"));
1525 restore_state(&head_commit->object.oid, &stash);
1526 }
1527 if (use_strategies_nr != 1)
1528 printf(_("Trying merge strategy %s...\n"),
1529 use_strategies[i]->name);
1530 /*
1531 * Remember which strategy left the state in the working
1532 * tree.
1533 */
1534 wt_strategy = use_strategies[i]->name;
1535
1536 ret = try_merge_strategy(use_strategies[i]->name,
1537 common, remoteheads,
1538 head_commit);
1539 if (!option_commit && !ret) {
1540 merge_was_ok = 1;
1541 /*
1542 * This is necessary here just to avoid writing
1543 * the tree, but later we will *not* exit with
1544 * status code 1 because merge_was_ok is set.
1545 */
1546 ret = 1;
1547 }
1548
1549 if (ret) {
1550 /*
1551 * The backend exits with 1 when conflicts are
1552 * left to be resolved, with 2 when it does not
1553 * handle the given merge at all.
1554 */
1555 if (ret == 1) {
1556 int cnt = evaluate_result();
1557
1558 if (best_cnt <= 0 || cnt <= best_cnt) {
1559 best_strategy = use_strategies[i]->name;
1560 best_cnt = cnt;
1561 }
1562 }
1563 if (merge_was_ok)
1564 break;
1565 else
1566 continue;
1567 }
1568
1569 /* Automerge succeeded. */
1570 write_tree_trivial(&result_tree);
1571 automerge_was_ok = 1;
1572 break;
1573 }
1574
1575 /*
1576 * If we have a resulting tree, that means the strategy module
1577 * auto resolved the merge cleanly.
1578 */
1579 if (automerge_was_ok) {
1580 ret = finish_automerge(head_commit, head_subsumed,
1581 common, remoteheads,
1582 &result_tree, wt_strategy);
1583 goto done;
1584 }
1585
1586 /*
1587 * Pick the result from the best strategy and have the user fix
1588 * it up.
1589 */
1590 if (!best_strategy) {
1591 restore_state(&head_commit->object.oid, &stash);
1592 if (use_strategies_nr > 1)
1593 fprintf(stderr,
1594 _("No merge strategy handled the merge.\n"));
1595 else
1596 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1597 use_strategies[0]->name);
1598 ret = 2;
1599 goto done;
1600 } else if (best_strategy == wt_strategy)
1601 ; /* We already have its result in the working tree. */
1602 else {
1603 printf(_("Rewinding the tree to pristine...\n"));
1604 restore_state(&head_commit->object.oid, &stash);
1605 printf(_("Using the %s to prepare resolving by hand.\n"),
1606 best_strategy);
1607 try_merge_strategy(best_strategy, common, remoteheads,
1608 head_commit);
1609 }
1610
1611 if (squash)
1612 finish(head_commit, remoteheads, NULL, NULL);
1613 else
1614 write_merge_state(remoteheads);
1615
1616 if (merge_was_ok)
1617 fprintf(stderr, _("Automatic merge went well; "
1618 "stopped before committing as requested\n"));
1619 else
1620 ret = suggest_conflicts();
1621
1622 done:
1623 free(branch_to_free);
1624 return ret;
1625 }