Merge branch 'jt/connectivity-check-after-unshallow'
[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 "refspec.h"
18 #include "commit.h"
19 #include "diffcore.h"
20 #include "revision.h"
21 #include "unpack-trees.h"
22 #include "cache-tree.h"
23 #include "dir.h"
24 #include "utf8.h"
25 #include "log-tree.h"
26 #include "color.h"
27 #include "rerere.h"
28 #include "help.h"
29 #include "merge-recursive.h"
30 #include "resolve-undo.h"
31 #include "remote.h"
32 #include "fmt-merge-msg.h"
33 #include "gpg-interface.h"
34 #include "sequencer.h"
35 #include "string-list.h"
36 #include "packfile.h"
37 #include "tag.h"
38 #include "alias.h"
39
40 #define DEFAULT_TWOHEAD (1<<0)
41 #define DEFAULT_OCTOPUS (1<<1)
42 #define NO_FAST_FORWARD (1<<2)
43 #define NO_TRIVIAL (1<<3)
44
45 struct strategy {
46 const char *name;
47 unsigned attr;
48 };
49
50 static const char * const builtin_merge_usage[] = {
51 N_("git merge [<options>] [<commit>...]"),
52 N_("git merge --abort"),
53 N_("git merge --continue"),
54 NULL
55 };
56
57 static int show_diffstat = 1, shortlog_len = -1, squash;
58 static int option_commit = 1;
59 static int option_edit = -1;
60 static int allow_trivial = 1, have_message, verify_signatures;
61 static int overwrite_ignore = 1;
62 static struct strbuf merge_msg = STRBUF_INIT;
63 static struct strategy **use_strategies;
64 static size_t use_strategies_nr, use_strategies_alloc;
65 static const char **xopts;
66 static size_t xopts_nr, xopts_alloc;
67 static const char *branch;
68 static char *branch_mergeoptions;
69 static int option_renormalize;
70 static int verbosity;
71 static int allow_rerere_auto;
72 static int abort_current_merge;
73 static int continue_current_merge;
74 static int allow_unrelated_histories;
75 static int show_progress = -1;
76 static int default_to_upstream = 1;
77 static int signoff;
78 static const char *sign_commit;
79 static int verify_msg = 1;
80
81 static struct strategy all_strategy[] = {
82 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
83 { "octopus", DEFAULT_OCTOPUS },
84 { "resolve", 0 },
85 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
86 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
87 };
88
89 static const char *pull_twohead, *pull_octopus;
90
91 enum ff_type {
92 FF_NO,
93 FF_ALLOW,
94 FF_ONLY
95 };
96
97 static enum ff_type fast_forward = FF_ALLOW;
98
99 static int option_parse_message(const struct option *opt,
100 const char *arg, int unset)
101 {
102 struct strbuf *buf = opt->value;
103
104 if (unset)
105 strbuf_setlen(buf, 0);
106 else if (arg) {
107 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
108 have_message = 1;
109 } else
110 return error(_("switch `m' requires a value"));
111 return 0;
112 }
113
114 static struct strategy *get_strategy(const char *name)
115 {
116 int i;
117 struct strategy *ret;
118 static struct cmdnames main_cmds, other_cmds;
119 static int loaded;
120
121 if (!name)
122 return NULL;
123
124 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
125 if (!strcmp(name, all_strategy[i].name))
126 return &all_strategy[i];
127
128 if (!loaded) {
129 struct cmdnames not_strategies;
130 loaded = 1;
131
132 memset(&not_strategies, 0, sizeof(struct cmdnames));
133 load_command_list("git-merge-", &main_cmds, &other_cmds);
134 for (i = 0; i < main_cmds.cnt; i++) {
135 int j, found = 0;
136 struct cmdname *ent = main_cmds.names[i];
137 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
138 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
139 && !all_strategy[j].name[ent->len])
140 found = 1;
141 if (!found)
142 add_cmdname(&not_strategies, ent->name, ent->len);
143 }
144 exclude_cmds(&main_cmds, &not_strategies);
145 }
146 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
147 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
148 fprintf(stderr, _("Available strategies are:"));
149 for (i = 0; i < main_cmds.cnt; i++)
150 fprintf(stderr, " %s", main_cmds.names[i]->name);
151 fprintf(stderr, ".\n");
152 if (other_cmds.cnt) {
153 fprintf(stderr, _("Available custom strategies are:"));
154 for (i = 0; i < other_cmds.cnt; i++)
155 fprintf(stderr, " %s", other_cmds.names[i]->name);
156 fprintf(stderr, ".\n");
157 }
158 exit(1);
159 }
160
161 ret = xcalloc(1, sizeof(struct strategy));
162 ret->name = xstrdup(name);
163 ret->attr = NO_TRIVIAL;
164 return ret;
165 }
166
167 static void append_strategy(struct strategy *s)
168 {
169 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
170 use_strategies[use_strategies_nr++] = s;
171 }
172
173 static int option_parse_strategy(const struct option *opt,
174 const char *name, int unset)
175 {
176 if (unset)
177 return 0;
178
179 append_strategy(get_strategy(name));
180 return 0;
181 }
182
183 static int option_parse_x(const struct option *opt,
184 const char *arg, int unset)
185 {
186 if (unset)
187 return 0;
188
189 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
190 xopts[xopts_nr++] = xstrdup(arg);
191 return 0;
192 }
193
194 static int option_parse_n(const struct option *opt,
195 const char *arg, int unset)
196 {
197 show_diffstat = unset;
198 return 0;
199 }
200
201 static struct option builtin_merge_options[] = {
202 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
203 N_("do not show a diffstat at the end of the merge"),
204 PARSE_OPT_NOARG, option_parse_n },
205 OPT_BOOL(0, "stat", &show_diffstat,
206 N_("show a diffstat at the end of the merge")),
207 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
208 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
209 N_("add (at most <n>) entries from shortlog to merge commit message"),
210 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
211 OPT_BOOL(0, "squash", &squash,
212 N_("create a single commit instead of doing a merge")),
213 OPT_BOOL(0, "commit", &option_commit,
214 N_("perform a commit if the merge succeeds (default)")),
215 OPT_BOOL('e', "edit", &option_edit,
216 N_("edit message before committing")),
217 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
218 OPT_SET_INT_F(0, "ff-only", &fast_forward,
219 N_("abort if fast-forward is not possible"),
220 FF_ONLY, PARSE_OPT_NONEG),
221 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
222 OPT_BOOL(0, "verify-signatures", &verify_signatures,
223 N_("verify that the named commit has a valid GPG signature")),
224 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
225 N_("merge strategy to use"), option_parse_strategy),
226 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
227 N_("option for selected merge strategy"), option_parse_x),
228 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
229 N_("merge commit message (for a non-fast-forward merge)"),
230 option_parse_message),
231 OPT__VERBOSITY(&verbosity),
232 OPT_BOOL(0, "abort", &abort_current_merge,
233 N_("abort the current in-progress merge")),
234 OPT_BOOL(0, "continue", &continue_current_merge,
235 N_("continue the current in-progress merge")),
236 OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
237 N_("allow merging unrelated histories")),
238 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
239 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
240 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
241 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
242 OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
243 OPT_BOOL(0, "verify", &verify_msg, N_("verify commit-msg hook")),
244 OPT_END()
245 };
246
247 /* Cleans up metadata that is uninteresting after a succeeded merge. */
248 static void drop_save(void)
249 {
250 unlink(git_path_merge_head(the_repository));
251 unlink(git_path_merge_msg(the_repository));
252 unlink(git_path_merge_mode(the_repository));
253 }
254
255 static int save_state(struct object_id *stash)
256 {
257 int len;
258 struct child_process cp = CHILD_PROCESS_INIT;
259 struct strbuf buffer = STRBUF_INIT;
260 const char *argv[] = {"stash", "create", NULL};
261 int rc = -1;
262
263 cp.argv = argv;
264 cp.out = -1;
265 cp.git_cmd = 1;
266
267 if (start_command(&cp))
268 die(_("could not run stash."));
269 len = strbuf_read(&buffer, cp.out, 1024);
270 close(cp.out);
271
272 if (finish_command(&cp) || len < 0)
273 die(_("stash failed"));
274 else if (!len) /* no changes */
275 goto out;
276 strbuf_setlen(&buffer, buffer.len-1);
277 if (get_oid(buffer.buf, stash))
278 die(_("not a valid object: %s"), buffer.buf);
279 rc = 0;
280 out:
281 strbuf_release(&buffer);
282 return rc;
283 }
284
285 static void read_empty(const struct object_id *oid, int verbose)
286 {
287 int i = 0;
288 const char *args[7];
289
290 args[i++] = "read-tree";
291 if (verbose)
292 args[i++] = "-v";
293 args[i++] = "-m";
294 args[i++] = "-u";
295 args[i++] = empty_tree_oid_hex();
296 args[i++] = oid_to_hex(oid);
297 args[i] = NULL;
298
299 if (run_command_v_opt(args, RUN_GIT_CMD))
300 die(_("read-tree failed"));
301 }
302
303 static void reset_hard(const struct object_id *oid, int verbose)
304 {
305 int i = 0;
306 const char *args[6];
307
308 args[i++] = "read-tree";
309 if (verbose)
310 args[i++] = "-v";
311 args[i++] = "--reset";
312 args[i++] = "-u";
313 args[i++] = oid_to_hex(oid);
314 args[i] = NULL;
315
316 if (run_command_v_opt(args, RUN_GIT_CMD))
317 die(_("read-tree failed"));
318 }
319
320 static void restore_state(const struct object_id *head,
321 const struct object_id *stash)
322 {
323 struct strbuf sb = STRBUF_INIT;
324 const char *args[] = { "stash", "apply", NULL, NULL };
325
326 if (is_null_oid(stash))
327 return;
328
329 reset_hard(head, 1);
330
331 args[2] = oid_to_hex(stash);
332
333 /*
334 * It is OK to ignore error here, for example when there was
335 * nothing to restore.
336 */
337 run_command_v_opt(args, RUN_GIT_CMD);
338
339 strbuf_release(&sb);
340 refresh_cache(REFRESH_QUIET);
341 }
342
343 /* This is called when no merge was necessary. */
344 static void finish_up_to_date(const char *msg)
345 {
346 if (verbosity >= 0)
347 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
348 drop_save();
349 }
350
351 static void squash_message(struct commit *commit, struct commit_list *remoteheads)
352 {
353 struct rev_info rev;
354 struct strbuf out = STRBUF_INIT;
355 struct commit_list *j;
356 struct pretty_print_context ctx = {0};
357
358 printf(_("Squash commit -- not updating HEAD\n"));
359
360 init_revisions(&rev, NULL);
361 rev.ignore_merges = 1;
362 rev.commit_format = CMIT_FMT_MEDIUM;
363
364 commit->object.flags |= UNINTERESTING;
365 add_pending_object(&rev, &commit->object, NULL);
366
367 for (j = remoteheads; j; j = j->next)
368 add_pending_object(&rev, &j->item->object, NULL);
369
370 setup_revisions(0, NULL, &rev, NULL);
371 if (prepare_revision_walk(&rev))
372 die(_("revision walk setup failed"));
373
374 ctx.abbrev = rev.abbrev;
375 ctx.date_mode = rev.date_mode;
376 ctx.fmt = rev.commit_format;
377
378 strbuf_addstr(&out, "Squashed commit of the following:\n");
379 while ((commit = get_revision(&rev)) != NULL) {
380 strbuf_addch(&out, '\n');
381 strbuf_addf(&out, "commit %s\n",
382 oid_to_hex(&commit->object.oid));
383 pretty_print_commit(&ctx, commit, &out);
384 }
385 write_file_buf(git_path_squash_msg(the_repository), out.buf, out.len);
386 strbuf_release(&out);
387 }
388
389 static void finish(struct commit *head_commit,
390 struct commit_list *remoteheads,
391 const struct object_id *new_head, const char *msg)
392 {
393 struct strbuf reflog_message = STRBUF_INIT;
394 const struct object_id *head = &head_commit->object.oid;
395
396 if (!msg)
397 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
398 else {
399 if (verbosity >= 0)
400 printf("%s\n", msg);
401 strbuf_addf(&reflog_message, "%s: %s",
402 getenv("GIT_REFLOG_ACTION"), msg);
403 }
404 if (squash) {
405 squash_message(head_commit, remoteheads);
406 } else {
407 if (verbosity >= 0 && !merge_msg.len)
408 printf(_("No merge message -- not updating HEAD\n"));
409 else {
410 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
411 update_ref(reflog_message.buf, "HEAD", new_head, head,
412 0, UPDATE_REFS_DIE_ON_ERR);
413 /*
414 * We ignore errors in 'gc --auto', since the
415 * user should see them.
416 */
417 close_all_packs(the_repository->objects);
418 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
419 }
420 }
421 if (new_head && show_diffstat) {
422 struct diff_options opts;
423 diff_setup(&opts);
424 opts.stat_width = -1; /* use full terminal width */
425 opts.stat_graph_width = -1; /* respect statGraphWidth config */
426 opts.output_format |=
427 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
428 opts.detect_rename = DIFF_DETECT_RENAME;
429 diff_setup_done(&opts);
430 diff_tree_oid(head, new_head, "", &opts);
431 diffcore_std(&opts);
432 diff_flush(&opts);
433 }
434
435 /* Run a post-merge hook */
436 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
437
438 strbuf_release(&reflog_message);
439 }
440
441 /* Get the name for the merge commit's message. */
442 static void merge_name(const char *remote, struct strbuf *msg)
443 {
444 struct commit *remote_head;
445 struct object_id branch_head;
446 struct strbuf buf = STRBUF_INIT;
447 struct strbuf bname = STRBUF_INIT;
448 struct merge_remote_desc *desc;
449 const char *ptr;
450 char *found_ref;
451 int len, early;
452
453 strbuf_branchname(&bname, remote, 0);
454 remote = bname.buf;
455
456 oidclr(&branch_head);
457 remote_head = get_merge_parent(remote);
458 if (!remote_head)
459 die(_("'%s' does not point to a commit"), remote);
460
461 if (dwim_ref(remote, strlen(remote), &branch_head, &found_ref) > 0) {
462 if (starts_with(found_ref, "refs/heads/")) {
463 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
464 oid_to_hex(&branch_head), remote);
465 goto cleanup;
466 }
467 if (starts_with(found_ref, "refs/tags/")) {
468 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
469 oid_to_hex(&branch_head), remote);
470 goto cleanup;
471 }
472 if (starts_with(found_ref, "refs/remotes/")) {
473 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
474 oid_to_hex(&branch_head), remote);
475 goto cleanup;
476 }
477 }
478
479 /* See if remote matches <name>^^^.. or <name>~<number> */
480 for (len = 0, ptr = remote + strlen(remote);
481 remote < ptr && ptr[-1] == '^';
482 ptr--)
483 len++;
484 if (len)
485 early = 1;
486 else {
487 early = 0;
488 ptr = strrchr(remote, '~');
489 if (ptr) {
490 int seen_nonzero = 0;
491
492 len++; /* count ~ */
493 while (*++ptr && isdigit(*ptr)) {
494 seen_nonzero |= (*ptr != '0');
495 len++;
496 }
497 if (*ptr)
498 len = 0; /* not ...~<number> */
499 else if (seen_nonzero)
500 early = 1;
501 else if (len == 1)
502 early = 1; /* "name~" is "name~1"! */
503 }
504 }
505 if (len) {
506 struct strbuf truname = STRBUF_INIT;
507 strbuf_addf(&truname, "refs/heads/%s", remote);
508 strbuf_setlen(&truname, truname.len - len);
509 if (ref_exists(truname.buf)) {
510 strbuf_addf(msg,
511 "%s\t\tbranch '%s'%s of .\n",
512 oid_to_hex(&remote_head->object.oid),
513 truname.buf + 11,
514 (early ? " (early part)" : ""));
515 strbuf_release(&truname);
516 goto cleanup;
517 }
518 strbuf_release(&truname);
519 }
520
521 desc = merge_remote_util(remote_head);
522 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
523 strbuf_addf(msg, "%s\t\t%s '%s'\n",
524 oid_to_hex(&desc->obj->oid),
525 type_name(desc->obj->type),
526 remote);
527 goto cleanup;
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, 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 struct lock_file lock = LOCK_INIT;
651 const char *head_arg = "HEAD";
652
653 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
654 refresh_cache(REFRESH_QUIET);
655 if (write_locked_index(&the_index, &lock,
656 COMMIT_LOCK | SKIP_IF_UNCHANGED))
657 return error(_("Unable to write index."));
658
659 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
660 int clean, x;
661 struct commit *result;
662 struct commit_list *reversed = NULL;
663 struct merge_options o;
664 struct commit_list *j;
665
666 if (remoteheads->next) {
667 error(_("Not handling anything other than two heads merge."));
668 return 2;
669 }
670
671 init_merge_options(&o);
672 if (!strcmp(strategy, "subtree"))
673 o.subtree_shift = "";
674
675 o.renormalize = option_renormalize;
676 o.show_rename_progress =
677 show_progress == -1 ? isatty(2) : show_progress;
678
679 for (x = 0; x < xopts_nr; x++)
680 if (parse_merge_opt(&o, xopts[x]))
681 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
682
683 o.branch1 = head_arg;
684 o.branch2 = merge_remote_util(remoteheads->item)->name;
685
686 for (j = common; j; j = j->next)
687 commit_list_insert(j->item, &reversed);
688
689 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
690 clean = merge_recursive(&o, head,
691 remoteheads->item, reversed, &result);
692 if (clean < 0)
693 exit(128);
694 if (write_locked_index(&the_index, &lock,
695 COMMIT_LOCK | SKIP_IF_UNCHANGED))
696 die (_("unable to write %s"), get_index_file());
697 return clean ? 0 : 1;
698 } else {
699 return try_merge_command(strategy, xopts_nr, xopts,
700 common, head_arg, remoteheads);
701 }
702 }
703
704 static void count_diff_files(struct diff_queue_struct *q,
705 struct diff_options *opt, void *data)
706 {
707 int *count = data;
708
709 (*count) += q->nr;
710 }
711
712 static int count_unmerged_entries(void)
713 {
714 int i, ret = 0;
715
716 for (i = 0; i < active_nr; i++)
717 if (ce_stage(active_cache[i]))
718 ret++;
719
720 return ret;
721 }
722
723 static void add_strategies(const char *string, unsigned attr)
724 {
725 int i;
726
727 if (string) {
728 struct string_list list = STRING_LIST_INIT_DUP;
729 struct string_list_item *item;
730 string_list_split(&list, string, ' ', -1);
731 for_each_string_list_item(item, &list)
732 append_strategy(get_strategy(item->string));
733 string_list_clear(&list, 0);
734 return;
735 }
736 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
737 if (all_strategy[i].attr & attr)
738 append_strategy(&all_strategy[i]);
739
740 }
741
742 static void read_merge_msg(struct strbuf *msg)
743 {
744 const char *filename = git_path_merge_msg(the_repository);
745 strbuf_reset(msg);
746 if (strbuf_read_file(msg, filename, 0) < 0)
747 die_errno(_("Could not read from '%s'"), filename);
748 }
749
750 static void write_merge_state(struct commit_list *);
751 static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
752 {
753 if (err_msg)
754 error("%s", err_msg);
755 fprintf(stderr,
756 _("Not committing merge; use 'git commit' to complete the merge.\n"));
757 write_merge_state(remoteheads);
758 exit(1);
759 }
760
761 static const char merge_editor_comment[] =
762 N_("Please enter a commit message to explain why this merge is necessary,\n"
763 "especially if it merges an updated upstream into a topic branch.\n"
764 "\n"
765 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
766 "the commit.\n");
767
768 static void write_merge_heads(struct commit_list *);
769 static void prepare_to_commit(struct commit_list *remoteheads)
770 {
771 struct strbuf msg = STRBUF_INIT;
772 strbuf_addbuf(&msg, &merge_msg);
773 strbuf_addch(&msg, '\n');
774 if (squash)
775 BUG("the control must not reach here under --squash");
776 if (0 < option_edit)
777 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
778 if (signoff)
779 append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
780 write_merge_heads(remoteheads);
781 write_file_buf(git_path_merge_msg(the_repository), msg.buf, msg.len);
782 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
783 git_path_merge_msg(the_repository), "merge", NULL))
784 abort_commit(remoteheads, NULL);
785 if (0 < option_edit) {
786 if (launch_editor(git_path_merge_msg(the_repository), NULL, NULL))
787 abort_commit(remoteheads, NULL);
788 }
789
790 if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
791 "commit-msg",
792 git_path_merge_msg(the_repository), NULL))
793 abort_commit(remoteheads, NULL);
794
795 read_merge_msg(&msg);
796 strbuf_stripspace(&msg, 0 < option_edit);
797 if (!msg.len)
798 abort_commit(remoteheads, _("Empty commit message."));
799 strbuf_release(&merge_msg);
800 strbuf_addbuf(&merge_msg, &msg);
801 strbuf_release(&msg);
802 }
803
804 static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
805 {
806 struct object_id result_tree, result_commit;
807 struct commit_list *parents, **pptr = &parents;
808 struct lock_file lock = LOCK_INIT;
809
810 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
811 refresh_cache(REFRESH_QUIET);
812 if (write_locked_index(&the_index, &lock,
813 COMMIT_LOCK | SKIP_IF_UNCHANGED))
814 return error(_("Unable to write index."));
815
816 write_tree_trivial(&result_tree);
817 printf(_("Wonderful.\n"));
818 pptr = commit_list_append(head, pptr);
819 pptr = commit_list_append(remoteheads->item, pptr);
820 prepare_to_commit(remoteheads);
821 if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
822 &result_commit, NULL, sign_commit))
823 die(_("failed to write commit object"));
824 finish(head, remoteheads, &result_commit, "In-index merge");
825 drop_save();
826 return 0;
827 }
828
829 static int finish_automerge(struct commit *head,
830 int head_subsumed,
831 struct commit_list *common,
832 struct commit_list *remoteheads,
833 struct object_id *result_tree,
834 const char *wt_strategy)
835 {
836 struct commit_list *parents = NULL;
837 struct strbuf buf = STRBUF_INIT;
838 struct object_id result_commit;
839
840 free_commit_list(common);
841 parents = remoteheads;
842 if (!head_subsumed || fast_forward == FF_NO)
843 commit_list_insert(head, &parents);
844 strbuf_addch(&merge_msg, '\n');
845 prepare_to_commit(remoteheads);
846 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
847 &result_commit, NULL, sign_commit))
848 die(_("failed to write commit object"));
849 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
850 finish(head, remoteheads, &result_commit, buf.buf);
851 strbuf_release(&buf);
852 drop_save();
853 return 0;
854 }
855
856 static int suggest_conflicts(void)
857 {
858 const char *filename;
859 FILE *fp;
860 struct strbuf msgbuf = STRBUF_INIT;
861
862 filename = git_path_merge_msg(the_repository);
863 fp = xfopen(filename, "a");
864
865 append_conflicts_hint(&msgbuf);
866 fputs(msgbuf.buf, fp);
867 strbuf_release(&msgbuf);
868 fclose(fp);
869 rerere(allow_rerere_auto);
870 printf(_("Automatic merge failed; "
871 "fix conflicts and then commit the result.\n"));
872 return 1;
873 }
874
875 static int evaluate_result(void)
876 {
877 int cnt = 0;
878 struct rev_info rev;
879
880 /* Check how many files differ. */
881 init_revisions(&rev, "");
882 setup_revisions(0, NULL, &rev, NULL);
883 rev.diffopt.output_format |=
884 DIFF_FORMAT_CALLBACK;
885 rev.diffopt.format_callback = count_diff_files;
886 rev.diffopt.format_callback_data = &cnt;
887 run_diff_files(&rev, 0);
888
889 /*
890 * Check how many unmerged entries are
891 * there.
892 */
893 cnt += count_unmerged_entries();
894
895 return cnt;
896 }
897
898 /*
899 * Pretend as if the user told us to merge with the remote-tracking
900 * branch we have for the upstream of the current branch
901 */
902 static int setup_with_upstream(const char ***argv)
903 {
904 struct branch *branch = branch_get(NULL);
905 int i;
906 const char **args;
907
908 if (!branch)
909 die(_("No current branch."));
910 if (!branch->remote_name)
911 die(_("No remote for the current branch."));
912 if (!branch->merge_nr)
913 die(_("No default upstream defined for the current branch."));
914
915 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
916 for (i = 0; i < branch->merge_nr; i++) {
917 if (!branch->merge[i]->dst)
918 die(_("No remote-tracking branch for %s from %s"),
919 branch->merge[i]->src, branch->remote_name);
920 args[i] = branch->merge[i]->dst;
921 }
922 args[i] = NULL;
923 *argv = args;
924 return i;
925 }
926
927 static void write_merge_heads(struct commit_list *remoteheads)
928 {
929 struct commit_list *j;
930 struct strbuf buf = STRBUF_INIT;
931
932 for (j = remoteheads; j; j = j->next) {
933 struct object_id *oid;
934 struct commit *c = j->item;
935 struct merge_remote_desc *desc;
936
937 desc = merge_remote_util(c);
938 if (desc && desc->obj) {
939 oid = &desc->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(the_repository), 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(the_repository), 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(the_repository), merge_msg.buf,
959 merge_msg.len);
960 }
961
962 static int default_edit_option(void)
963 {
964 static const char name[] = "GIT_MERGE_AUTOEDIT";
965 const char *e = getenv(name);
966 struct stat st_stdin, st_stdout;
967
968 if (have_message)
969 /* an explicit -m msg without --[no-]edit */
970 return 0;
971
972 if (e) {
973 int v = git_parse_maybe_bool(e);
974 if (v < 0)
975 die(_("Bad value '%s' in environment '%s'"), e, name);
976 return v;
977 }
978
979 /* Use editor if stdin and stdout are the same and is a tty */
980 return (!fstat(0, &st_stdin) &&
981 !fstat(1, &st_stdout) &&
982 isatty(0) && isatty(1) &&
983 st_stdin.st_dev == st_stdout.st_dev &&
984 st_stdin.st_ino == st_stdout.st_ino &&
985 st_stdin.st_mode == st_stdout.st_mode);
986 }
987
988 static struct commit_list *reduce_parents(struct commit *head_commit,
989 int *head_subsumed,
990 struct commit_list *remoteheads)
991 {
992 struct commit_list *parents, **remotes;
993
994 /*
995 * Is the current HEAD reachable from another commit being
996 * merged? If so we do not want to record it as a parent of
997 * the resulting merge, unless --no-ff is given. We will flip
998 * this variable to 0 when we find HEAD among the independent
999 * tips being merged.
1000 */
1001 *head_subsumed = 1;
1002
1003 /* Find what parents to record by checking independent ones. */
1004 parents = reduce_heads(remoteheads);
1005 free_commit_list(remoteheads);
1006
1007 remoteheads = NULL;
1008 remotes = &remoteheads;
1009 while (parents) {
1010 struct commit *commit = pop_commit(&parents);
1011 if (commit == head_commit)
1012 *head_subsumed = 0;
1013 else
1014 remotes = &commit_list_insert(commit, remotes)->next;
1015 }
1016 return remoteheads;
1017 }
1018
1019 static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1020 {
1021 struct fmt_merge_msg_opts opts;
1022
1023 memset(&opts, 0, sizeof(opts));
1024 opts.add_title = !have_message;
1025 opts.shortlog_len = shortlog_len;
1026 opts.credit_people = (0 < option_edit);
1027
1028 fmt_merge_msg(merge_names, merge_msg, &opts);
1029 if (merge_msg->len)
1030 strbuf_setlen(merge_msg, merge_msg->len - 1);
1031 }
1032
1033 static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1034 {
1035 const char *filename;
1036 int fd, pos, npos;
1037 struct strbuf fetch_head_file = STRBUF_INIT;
1038
1039 if (!merge_names)
1040 merge_names = &fetch_head_file;
1041
1042 filename = git_path_fetch_head(the_repository);
1043 fd = open(filename, O_RDONLY);
1044 if (fd < 0)
1045 die_errno(_("could not open '%s' for reading"), filename);
1046
1047 if (strbuf_read(merge_names, fd, 0) < 0)
1048 die_errno(_("could not read '%s'"), filename);
1049 if (close(fd) < 0)
1050 die_errno(_("could not close '%s'"), filename);
1051
1052 for (pos = 0; pos < merge_names->len; pos = npos) {
1053 struct object_id oid;
1054 char *ptr;
1055 struct commit *commit;
1056
1057 ptr = strchr(merge_names->buf + pos, '\n');
1058 if (ptr)
1059 npos = ptr - merge_names->buf + 1;
1060 else
1061 npos = merge_names->len;
1062
1063 if (npos - pos < GIT_SHA1_HEXSZ + 2 ||
1064 get_oid_hex(merge_names->buf + pos, &oid))
1065 commit = NULL; /* bad */
1066 else if (memcmp(merge_names->buf + pos + GIT_SHA1_HEXSZ, "\t\t", 2))
1067 continue; /* not-for-merge */
1068 else {
1069 char saved = merge_names->buf[pos + GIT_SHA1_HEXSZ];
1070 merge_names->buf[pos + GIT_SHA1_HEXSZ] = '\0';
1071 commit = get_merge_parent(merge_names->buf + pos);
1072 merge_names->buf[pos + GIT_SHA1_HEXSZ] = saved;
1073 }
1074 if (!commit) {
1075 if (ptr)
1076 *ptr = '\0';
1077 die(_("not something we can merge in %s: %s"),
1078 filename, merge_names->buf + pos);
1079 }
1080 remotes = &commit_list_insert(commit, remotes)->next;
1081 }
1082
1083 if (merge_names == &fetch_head_file)
1084 strbuf_release(&fetch_head_file);
1085 }
1086
1087 static struct commit_list *collect_parents(struct commit *head_commit,
1088 int *head_subsumed,
1089 int argc, const char **argv,
1090 struct strbuf *merge_msg)
1091 {
1092 int i;
1093 struct commit_list *remoteheads = NULL;
1094 struct commit_list **remotes = &remoteheads;
1095 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1096
1097 if (merge_msg && (!have_message || shortlog_len))
1098 autogen = &merge_names;
1099
1100 if (head_commit)
1101 remotes = &commit_list_insert(head_commit, remotes)->next;
1102
1103 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1104 handle_fetch_head(remotes, autogen);
1105 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1106 } else {
1107 for (i = 0; i < argc; i++) {
1108 struct commit *commit = get_merge_parent(argv[i]);
1109 if (!commit)
1110 help_unknown_ref(argv[i], "merge",
1111 _("not something we can merge"));
1112 remotes = &commit_list_insert(commit, remotes)->next;
1113 }
1114 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1115 if (autogen) {
1116 struct commit_list *p;
1117 for (p = remoteheads; p; p = p->next)
1118 merge_name(merge_remote_util(p->item)->name, autogen);
1119 }
1120 }
1121
1122 if (autogen) {
1123 prepare_merge_message(autogen, merge_msg);
1124 strbuf_release(autogen);
1125 }
1126
1127 return remoteheads;
1128 }
1129
1130 static int merging_a_throwaway_tag(struct commit *commit)
1131 {
1132 char *tag_ref;
1133 struct object_id oid;
1134 int is_throwaway_tag = 0;
1135
1136 /* Are we merging a tag? */
1137 if (!merge_remote_util(commit) ||
1138 !merge_remote_util(commit)->obj ||
1139 merge_remote_util(commit)->obj->type != OBJ_TAG)
1140 return is_throwaway_tag;
1141
1142 /*
1143 * Now we know we are merging a tag object. Are we downstream
1144 * and following the tags from upstream? If so, we must have
1145 * the tag object pointed at by "refs/tags/$T" where $T is the
1146 * tagname recorded in the tag object. We want to allow such
1147 * a "just to catch up" merge to fast-forward.
1148 *
1149 * Otherwise, we are playing an integrator's role, making a
1150 * merge with a throw-away tag from a contributor with
1151 * something like "git pull $contributor $signed_tag".
1152 * We want to forbid such a merge from fast-forwarding
1153 * by default; otherwise we would not keep the signature
1154 * anywhere.
1155 */
1156 tag_ref = xstrfmt("refs/tags/%s",
1157 ((struct tag *)merge_remote_util(commit)->obj)->tag);
1158 if (!read_ref(tag_ref, &oid) &&
1159 !oidcmp(&oid, &merge_remote_util(commit)->obj->oid))
1160 is_throwaway_tag = 0;
1161 else
1162 is_throwaway_tag = 1;
1163 free(tag_ref);
1164 return is_throwaway_tag;
1165 }
1166
1167 int cmd_merge(int argc, const char **argv, const char *prefix)
1168 {
1169 struct object_id result_tree, stash, head_oid;
1170 struct commit *head_commit;
1171 struct strbuf buf = STRBUF_INIT;
1172 int i, ret = 0, head_subsumed;
1173 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1174 struct commit_list *common = NULL;
1175 const char *best_strategy = NULL, *wt_strategy = NULL;
1176 struct commit_list *remoteheads, *p;
1177 void *branch_to_free;
1178 int orig_argc = argc;
1179
1180 if (argc == 2 && !strcmp(argv[1], "-h"))
1181 usage_with_options(builtin_merge_usage, builtin_merge_options);
1182
1183 /*
1184 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1185 * current branch.
1186 */
1187 branch = branch_to_free = resolve_refdup("HEAD", 0, &head_oid, NULL);
1188 if (branch)
1189 skip_prefix(branch, "refs/heads/", &branch);
1190
1191 init_diff_ui_defaults();
1192 git_config(git_merge_config, NULL);
1193
1194 if (!branch || is_null_oid(&head_oid))
1195 head_commit = NULL;
1196 else
1197 head_commit = lookup_commit_or_die(&head_oid, "HEAD");
1198
1199 if (branch_mergeoptions)
1200 parse_branch_merge_options(branch_mergeoptions);
1201 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1202 builtin_merge_usage, 0);
1203 if (shortlog_len < 0)
1204 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1205
1206 if (verbosity < 0 && show_progress == -1)
1207 show_progress = 0;
1208
1209 if (abort_current_merge) {
1210 int nargc = 2;
1211 const char *nargv[] = {"reset", "--merge", NULL};
1212
1213 if (orig_argc != 2)
1214 usage_msg_opt(_("--abort expects no arguments"),
1215 builtin_merge_usage, builtin_merge_options);
1216
1217 if (!file_exists(git_path_merge_head(the_repository)))
1218 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1219
1220 /* Invoke 'git reset --merge' */
1221 ret = cmd_reset(nargc, nargv, prefix);
1222 goto done;
1223 }
1224
1225 if (continue_current_merge) {
1226 int nargc = 1;
1227 const char *nargv[] = {"commit", NULL};
1228
1229 if (orig_argc != 2)
1230 usage_msg_opt(_("--continue expects no arguments"),
1231 builtin_merge_usage, builtin_merge_options);
1232
1233 if (!file_exists(git_path_merge_head(the_repository)))
1234 die(_("There is no merge in progress (MERGE_HEAD missing)."));
1235
1236 /* Invoke 'git commit' */
1237 ret = cmd_commit(nargc, nargv, prefix);
1238 goto done;
1239 }
1240
1241 if (read_cache_unmerged())
1242 die_resolve_conflict("merge");
1243
1244 if (file_exists(git_path_merge_head(the_repository))) {
1245 /*
1246 * There is no unmerged entry, don't advise 'git
1247 * add/rm <file>', just 'git commit'.
1248 */
1249 if (advice_resolve_conflict)
1250 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1251 "Please, commit your changes before you merge."));
1252 else
1253 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1254 }
1255 if (file_exists(git_path_cherry_pick_head(the_repository))) {
1256 if (advice_resolve_conflict)
1257 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1258 "Please, commit your changes before you merge."));
1259 else
1260 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1261 }
1262 resolve_undo_clear();
1263
1264 if (verbosity < 0)
1265 show_diffstat = 0;
1266
1267 if (squash) {
1268 if (fast_forward == FF_NO)
1269 die(_("You cannot combine --squash with --no-ff."));
1270 option_commit = 0;
1271 }
1272
1273 if (!argc) {
1274 if (default_to_upstream)
1275 argc = setup_with_upstream(&argv);
1276 else
1277 die(_("No commit specified and merge.defaultToUpstream not set."));
1278 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1279 argv[0] = "@{-1}";
1280 }
1281
1282 if (!argc)
1283 usage_with_options(builtin_merge_usage,
1284 builtin_merge_options);
1285
1286 if (!head_commit) {
1287 /*
1288 * If the merged head is a valid one there is no reason
1289 * to forbid "git merge" into a branch yet to be born.
1290 * We do the same for "git pull".
1291 */
1292 struct object_id *remote_head_oid;
1293 if (squash)
1294 die(_("Squash commit into empty head not supported yet"));
1295 if (fast_forward == FF_NO)
1296 die(_("Non-fast-forward commit does not make sense into "
1297 "an empty head"));
1298 remoteheads = collect_parents(head_commit, &head_subsumed,
1299 argc, argv, NULL);
1300 if (!remoteheads)
1301 die(_("%s - not something we can merge"), argv[0]);
1302 if (remoteheads->next)
1303 die(_("Can merge only exactly one commit into empty head"));
1304 remote_head_oid = &remoteheads->item->object.oid;
1305 read_empty(remote_head_oid, 0);
1306 update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
1307 UPDATE_REFS_DIE_ON_ERR);
1308 goto done;
1309 }
1310
1311 /*
1312 * All the rest are the commits being merged; prepare
1313 * the standard merge summary message to be appended
1314 * to the given message.
1315 */
1316 remoteheads = collect_parents(head_commit, &head_subsumed,
1317 argc, argv, &merge_msg);
1318
1319 if (!head_commit || !argc)
1320 usage_with_options(builtin_merge_usage,
1321 builtin_merge_options);
1322
1323 if (verify_signatures) {
1324 for (p = remoteheads; p; p = p->next) {
1325 struct commit *commit = p->item;
1326 char hex[GIT_MAX_HEXSZ + 1];
1327 struct signature_check signature_check;
1328 memset(&signature_check, 0, sizeof(signature_check));
1329
1330 check_commit_signature(commit, &signature_check);
1331
1332 find_unique_abbrev_r(hex, &commit->object.oid, DEFAULT_ABBREV);
1333 switch (signature_check.result) {
1334 case 'G':
1335 break;
1336 case 'U':
1337 die(_("Commit %s has an untrusted GPG signature, "
1338 "allegedly by %s."), hex, signature_check.signer);
1339 case 'B':
1340 die(_("Commit %s has a bad GPG signature "
1341 "allegedly by %s."), hex, signature_check.signer);
1342 default: /* 'N' */
1343 die(_("Commit %s does not have a GPG signature."), hex);
1344 }
1345 if (verbosity >= 0 && signature_check.result == 'G')
1346 printf(_("Commit %s has a good GPG signature by %s\n"),
1347 hex, signature_check.signer);
1348
1349 signature_check_clear(&signature_check);
1350 }
1351 }
1352
1353 strbuf_addstr(&buf, "merge");
1354 for (p = remoteheads; p; p = p->next)
1355 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1356 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1357 strbuf_reset(&buf);
1358
1359 for (p = remoteheads; p; p = p->next) {
1360 struct commit *commit = p->item;
1361 strbuf_addf(&buf, "GITHEAD_%s",
1362 oid_to_hex(&commit->object.oid));
1363 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1364 strbuf_reset(&buf);
1365 if (fast_forward != FF_ONLY && merging_a_throwaway_tag(commit))
1366 fast_forward = FF_NO;
1367 }
1368
1369 if (option_edit < 0)
1370 option_edit = default_edit_option();
1371
1372 if (!use_strategies) {
1373 if (!remoteheads)
1374 ; /* already up-to-date */
1375 else if (!remoteheads->next)
1376 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1377 else
1378 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1379 }
1380
1381 for (i = 0; i < use_strategies_nr; i++) {
1382 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1383 fast_forward = FF_NO;
1384 if (use_strategies[i]->attr & NO_TRIVIAL)
1385 allow_trivial = 0;
1386 }
1387
1388 if (!remoteheads)
1389 ; /* already up-to-date */
1390 else if (!remoteheads->next)
1391 common = get_merge_bases(head_commit, remoteheads->item);
1392 else {
1393 struct commit_list *list = remoteheads;
1394 commit_list_insert(head_commit, &list);
1395 common = get_octopus_merge_bases(list);
1396 free(list);
1397 }
1398
1399 update_ref("updating ORIG_HEAD", "ORIG_HEAD",
1400 &head_commit->object.oid, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1401
1402 if (remoteheads && !common) {
1403 /* No common ancestors found. */
1404 if (!allow_unrelated_histories)
1405 die(_("refusing to merge unrelated histories"));
1406 /* otherwise, we need a real merge. */
1407 } else if (!remoteheads ||
1408 (!remoteheads->next && !common->next &&
1409 common->item == remoteheads->item)) {
1410 /*
1411 * If head can reach all the merge then we are up to date.
1412 * but first the most common case of merging one remote.
1413 */
1414 finish_up_to_date(_("Already up to date."));
1415 goto done;
1416 } else if (fast_forward != FF_NO && !remoteheads->next &&
1417 !common->next &&
1418 !oidcmp(&common->item->object.oid, &head_commit->object.oid)) {
1419 /* Again the most common case of merging one remote. */
1420 struct strbuf msg = STRBUF_INIT;
1421 struct commit *commit;
1422
1423 if (verbosity >= 0) {
1424 printf(_("Updating %s..%s\n"),
1425 find_unique_abbrev(&head_commit->object.oid,
1426 DEFAULT_ABBREV),
1427 find_unique_abbrev(&remoteheads->item->object.oid,
1428 DEFAULT_ABBREV));
1429 }
1430 strbuf_addstr(&msg, "Fast-forward");
1431 if (have_message)
1432 strbuf_addstr(&msg,
1433 " (no commit created; -m option ignored)");
1434 commit = remoteheads->item;
1435 if (!commit) {
1436 ret = 1;
1437 goto done;
1438 }
1439
1440 if (checkout_fast_forward(&head_commit->object.oid,
1441 &commit->object.oid,
1442 overwrite_ignore)) {
1443 ret = 1;
1444 goto done;
1445 }
1446
1447 finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
1448 drop_save();
1449 goto done;
1450 } else if (!remoteheads->next && common->next)
1451 ;
1452 /*
1453 * We are not doing octopus and not fast-forward. Need
1454 * a real merge.
1455 */
1456 else if (!remoteheads->next && !common->next && option_commit) {
1457 /*
1458 * We are not doing octopus, not fast-forward, and have
1459 * only one common.
1460 */
1461 refresh_cache(REFRESH_QUIET);
1462 if (allow_trivial && fast_forward != FF_ONLY) {
1463 /* See if it is really trivial. */
1464 git_committer_info(IDENT_STRICT);
1465 printf(_("Trying really trivial in-index merge...\n"));
1466 if (!read_tree_trivial(&common->item->object.oid,
1467 &head_commit->object.oid,
1468 &remoteheads->item->object.oid)) {
1469 ret = merge_trivial(head_commit, remoteheads);
1470 goto done;
1471 }
1472 printf(_("Nope.\n"));
1473 }
1474 } else {
1475 /*
1476 * An octopus. If we can reach all the remote we are up
1477 * to date.
1478 */
1479 int up_to_date = 1;
1480 struct commit_list *j;
1481
1482 for (j = remoteheads; j; j = j->next) {
1483 struct commit_list *common_one;
1484
1485 /*
1486 * Here we *have* to calculate the individual
1487 * merge_bases again, otherwise "git merge HEAD^
1488 * HEAD^^" would be missed.
1489 */
1490 common_one = get_merge_bases(head_commit, j->item);
1491 if (oidcmp(&common_one->item->object.oid, &j->item->object.oid)) {
1492 up_to_date = 0;
1493 break;
1494 }
1495 }
1496 if (up_to_date) {
1497 finish_up_to_date(_("Already up to date. Yeeah!"));
1498 goto done;
1499 }
1500 }
1501
1502 if (fast_forward == FF_ONLY)
1503 die(_("Not possible to fast-forward, aborting."));
1504
1505 /* We are going to make a new commit. */
1506 git_committer_info(IDENT_STRICT);
1507
1508 /*
1509 * At this point, we need a real merge. No matter what strategy
1510 * we use, it would operate on the index, possibly affecting the
1511 * working tree, and when resolved cleanly, have the desired
1512 * tree in the index -- this means that the index must be in
1513 * sync with the head commit. The strategies are responsible
1514 * to ensure this.
1515 */
1516 if (use_strategies_nr == 1 ||
1517 /*
1518 * Stash away the local changes so that we can try more than one.
1519 */
1520 save_state(&stash))
1521 oidclr(&stash);
1522
1523 for (i = 0; i < use_strategies_nr; i++) {
1524 int ret;
1525 if (i) {
1526 printf(_("Rewinding the tree to pristine...\n"));
1527 restore_state(&head_commit->object.oid, &stash);
1528 }
1529 if (use_strategies_nr != 1)
1530 printf(_("Trying merge strategy %s...\n"),
1531 use_strategies[i]->name);
1532 /*
1533 * Remember which strategy left the state in the working
1534 * tree.
1535 */
1536 wt_strategy = use_strategies[i]->name;
1537
1538 ret = try_merge_strategy(use_strategies[i]->name,
1539 common, remoteheads,
1540 head_commit);
1541 if (!option_commit && !ret) {
1542 merge_was_ok = 1;
1543 /*
1544 * This is necessary here just to avoid writing
1545 * the tree, but later we will *not* exit with
1546 * status code 1 because merge_was_ok is set.
1547 */
1548 ret = 1;
1549 }
1550
1551 if (ret) {
1552 /*
1553 * The backend exits with 1 when conflicts are
1554 * left to be resolved, with 2 when it does not
1555 * handle the given merge at all.
1556 */
1557 if (ret == 1) {
1558 int cnt = evaluate_result();
1559
1560 if (best_cnt <= 0 || cnt <= best_cnt) {
1561 best_strategy = use_strategies[i]->name;
1562 best_cnt = cnt;
1563 }
1564 }
1565 if (merge_was_ok)
1566 break;
1567 else
1568 continue;
1569 }
1570
1571 /* Automerge succeeded. */
1572 write_tree_trivial(&result_tree);
1573 automerge_was_ok = 1;
1574 break;
1575 }
1576
1577 /*
1578 * If we have a resulting tree, that means the strategy module
1579 * auto resolved the merge cleanly.
1580 */
1581 if (automerge_was_ok) {
1582 ret = finish_automerge(head_commit, head_subsumed,
1583 common, remoteheads,
1584 &result_tree, wt_strategy);
1585 goto done;
1586 }
1587
1588 /*
1589 * Pick the result from the best strategy and have the user fix
1590 * it up.
1591 */
1592 if (!best_strategy) {
1593 restore_state(&head_commit->object.oid, &stash);
1594 if (use_strategies_nr > 1)
1595 fprintf(stderr,
1596 _("No merge strategy handled the merge.\n"));
1597 else
1598 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1599 use_strategies[0]->name);
1600 ret = 2;
1601 goto done;
1602 } else if (best_strategy == wt_strategy)
1603 ; /* We already have its result in the working tree. */
1604 else {
1605 printf(_("Rewinding the tree to pristine...\n"));
1606 restore_state(&head_commit->object.oid, &stash);
1607 printf(_("Using the %s to prepare resolving by hand.\n"),
1608 best_strategy);
1609 try_merge_strategy(best_strategy, common, remoteheads,
1610 head_commit);
1611 }
1612
1613 if (squash)
1614 finish(head_commit, remoteheads, NULL, NULL);
1615 else
1616 write_merge_state(remoteheads);
1617
1618 if (merge_was_ok)
1619 fprintf(stderr, _("Automatic merge went well; "
1620 "stopped before committing as requested\n"));
1621 else
1622 ret = suggest_conflicts();
1623
1624 done:
1625 free(branch_to_free);
1626 return ret;
1627 }