Merge branch 'jn/preformatted-doc-url' into maint
[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 "parse-options.h"
11 #include "builtin.h"
12 #include "lockfile.h"
13 #include "run-command.h"
14 #include "diff.h"
15 #include "refs.h"
16 #include "commit.h"
17 #include "diffcore.h"
18 #include "revision.h"
19 #include "unpack-trees.h"
20 #include "cache-tree.h"
21 #include "dir.h"
22 #include "utf8.h"
23 #include "log-tree.h"
24 #include "color.h"
25 #include "rerere.h"
26 #include "help.h"
27 #include "merge-recursive.h"
28 #include "resolve-undo.h"
29 #include "remote.h"
30 #include "fmt-merge-msg.h"
31 #include "gpg-interface.h"
32 #include "sequencer.h"
33
34 #define DEFAULT_TWOHEAD (1<<0)
35 #define DEFAULT_OCTOPUS (1<<1)
36 #define NO_FAST_FORWARD (1<<2)
37 #define NO_TRIVIAL (1<<3)
38
39 struct strategy {
40 const char *name;
41 unsigned attr;
42 };
43
44 static const char * const builtin_merge_usage[] = {
45 N_("git merge [<options>] [<commit>...]"),
46 N_("git merge [<options>] <msg> HEAD <commit>"),
47 N_("git merge --abort"),
48 NULL
49 };
50
51 static int show_diffstat = 1, shortlog_len = -1, squash;
52 static int option_commit = 1;
53 static int option_edit = -1;
54 static int allow_trivial = 1, have_message, verify_signatures;
55 static int overwrite_ignore = 1;
56 static struct strbuf merge_msg = STRBUF_INIT;
57 static struct strategy **use_strategies;
58 static size_t use_strategies_nr, use_strategies_alloc;
59 static const char **xopts;
60 static size_t xopts_nr, xopts_alloc;
61 static const char *branch;
62 static char *branch_mergeoptions;
63 static int option_renormalize;
64 static int verbosity;
65 static int allow_rerere_auto;
66 static int abort_current_merge;
67 static int allow_unrelated_histories;
68 static int show_progress = -1;
69 static int default_to_upstream = 1;
70 static const char *sign_commit;
71
72 static struct strategy all_strategy[] = {
73 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
74 { "octopus", DEFAULT_OCTOPUS },
75 { "resolve", 0 },
76 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
77 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
78 };
79
80 static const char *pull_twohead, *pull_octopus;
81
82 enum ff_type {
83 FF_NO,
84 FF_ALLOW,
85 FF_ONLY
86 };
87
88 static enum ff_type fast_forward = FF_ALLOW;
89
90 static int option_parse_message(const struct option *opt,
91 const char *arg, int unset)
92 {
93 struct strbuf *buf = opt->value;
94
95 if (unset)
96 strbuf_setlen(buf, 0);
97 else if (arg) {
98 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
99 have_message = 1;
100 } else
101 return error(_("switch `m' requires a value"));
102 return 0;
103 }
104
105 static struct strategy *get_strategy(const char *name)
106 {
107 int i;
108 struct strategy *ret;
109 static struct cmdnames main_cmds, other_cmds;
110 static int loaded;
111
112 if (!name)
113 return NULL;
114
115 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
116 if (!strcmp(name, all_strategy[i].name))
117 return &all_strategy[i];
118
119 if (!loaded) {
120 struct cmdnames not_strategies;
121 loaded = 1;
122
123 memset(&not_strategies, 0, sizeof(struct cmdnames));
124 load_command_list("git-merge-", &main_cmds, &other_cmds);
125 for (i = 0; i < main_cmds.cnt; i++) {
126 int j, found = 0;
127 struct cmdname *ent = main_cmds.names[i];
128 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
129 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
130 && !all_strategy[j].name[ent->len])
131 found = 1;
132 if (!found)
133 add_cmdname(&not_strategies, ent->name, ent->len);
134 }
135 exclude_cmds(&main_cmds, &not_strategies);
136 }
137 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
138 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
139 fprintf(stderr, _("Available strategies are:"));
140 for (i = 0; i < main_cmds.cnt; i++)
141 fprintf(stderr, " %s", main_cmds.names[i]->name);
142 fprintf(stderr, ".\n");
143 if (other_cmds.cnt) {
144 fprintf(stderr, _("Available custom strategies are:"));
145 for (i = 0; i < other_cmds.cnt; i++)
146 fprintf(stderr, " %s", other_cmds.names[i]->name);
147 fprintf(stderr, ".\n");
148 }
149 exit(1);
150 }
151
152 ret = xcalloc(1, sizeof(struct strategy));
153 ret->name = xstrdup(name);
154 ret->attr = NO_TRIVIAL;
155 return ret;
156 }
157
158 static void append_strategy(struct strategy *s)
159 {
160 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
161 use_strategies[use_strategies_nr++] = s;
162 }
163
164 static int option_parse_strategy(const struct option *opt,
165 const char *name, int unset)
166 {
167 if (unset)
168 return 0;
169
170 append_strategy(get_strategy(name));
171 return 0;
172 }
173
174 static int option_parse_x(const struct option *opt,
175 const char *arg, int unset)
176 {
177 if (unset)
178 return 0;
179
180 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
181 xopts[xopts_nr++] = xstrdup(arg);
182 return 0;
183 }
184
185 static int option_parse_n(const struct option *opt,
186 const char *arg, int unset)
187 {
188 show_diffstat = unset;
189 return 0;
190 }
191
192 static struct option builtin_merge_options[] = {
193 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
194 N_("do not show a diffstat at the end of the merge"),
195 PARSE_OPT_NOARG, option_parse_n },
196 OPT_BOOL(0, "stat", &show_diffstat,
197 N_("show a diffstat at the end of the merge")),
198 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
199 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
200 N_("add (at most <n>) entries from shortlog to merge commit message"),
201 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
202 OPT_BOOL(0, "squash", &squash,
203 N_("create a single commit instead of doing a merge")),
204 OPT_BOOL(0, "commit", &option_commit,
205 N_("perform a commit if the merge succeeds (default)")),
206 OPT_BOOL('e', "edit", &option_edit,
207 N_("edit message before committing")),
208 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
209 { OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
210 N_("abort if fast-forward is not possible"),
211 PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
212 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
213 OPT_BOOL(0, "verify-signatures", &verify_signatures,
214 N_("Verify that the named commit has a valid GPG signature")),
215 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
216 N_("merge strategy to use"), option_parse_strategy),
217 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
218 N_("option for selected merge strategy"), option_parse_x),
219 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
220 N_("merge commit message (for a non-fast-forward merge)"),
221 option_parse_message),
222 OPT__VERBOSITY(&verbosity),
223 OPT_BOOL(0, "abort", &abort_current_merge,
224 N_("abort the current in-progress merge")),
225 OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
226 N_("allow merging unrelated histories")),
227 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
228 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
229 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
230 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
231 OPT_END()
232 };
233
234 /* Cleans up metadata that is uninteresting after a succeeded merge. */
235 static void drop_save(void)
236 {
237 unlink(git_path_merge_head());
238 unlink(git_path_merge_msg());
239 unlink(git_path_merge_mode());
240 }
241
242 static int save_state(unsigned char *stash)
243 {
244 int len;
245 struct child_process cp = CHILD_PROCESS_INIT;
246 struct strbuf buffer = STRBUF_INIT;
247 const char *argv[] = {"stash", "create", NULL};
248
249 cp.argv = argv;
250 cp.out = -1;
251 cp.git_cmd = 1;
252
253 if (start_command(&cp))
254 die(_("could not run stash."));
255 len = strbuf_read(&buffer, cp.out, 1024);
256 close(cp.out);
257
258 if (finish_command(&cp) || len < 0)
259 die(_("stash failed"));
260 else if (!len) /* no changes */
261 return -1;
262 strbuf_setlen(&buffer, buffer.len-1);
263 if (get_sha1(buffer.buf, stash))
264 die(_("not a valid object: %s"), buffer.buf);
265 return 0;
266 }
267
268 static void read_empty(unsigned const char *sha1, int verbose)
269 {
270 int i = 0;
271 const char *args[7];
272
273 args[i++] = "read-tree";
274 if (verbose)
275 args[i++] = "-v";
276 args[i++] = "-m";
277 args[i++] = "-u";
278 args[i++] = EMPTY_TREE_SHA1_HEX;
279 args[i++] = sha1_to_hex(sha1);
280 args[i] = NULL;
281
282 if (run_command_v_opt(args, RUN_GIT_CMD))
283 die(_("read-tree failed"));
284 }
285
286 static void reset_hard(unsigned const char *sha1, int verbose)
287 {
288 int i = 0;
289 const char *args[6];
290
291 args[i++] = "read-tree";
292 if (verbose)
293 args[i++] = "-v";
294 args[i++] = "--reset";
295 args[i++] = "-u";
296 args[i++] = sha1_to_hex(sha1);
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 restore_state(const unsigned char *head,
304 const unsigned char *stash)
305 {
306 struct strbuf sb = STRBUF_INIT;
307 const char *args[] = { "stash", "apply", NULL, NULL };
308
309 if (is_null_sha1(stash))
310 return;
311
312 reset_hard(head, 1);
313
314 args[2] = sha1_to_hex(stash);
315
316 /*
317 * It is OK to ignore error here, for example when there was
318 * nothing to restore.
319 */
320 run_command_v_opt(args, RUN_GIT_CMD);
321
322 strbuf_release(&sb);
323 refresh_cache(REFRESH_QUIET);
324 }
325
326 /* This is called when no merge was necessary. */
327 static void finish_up_to_date(const char *msg)
328 {
329 if (verbosity >= 0)
330 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
331 drop_save();
332 }
333
334 static void squash_message(struct commit *commit, struct commit_list *remoteheads)
335 {
336 struct rev_info rev;
337 struct strbuf out = STRBUF_INIT;
338 struct commit_list *j;
339 const char *filename;
340 int fd;
341 struct pretty_print_context ctx = {0};
342
343 printf(_("Squash commit -- not updating HEAD\n"));
344 filename = git_path_squash_msg();
345 fd = open(filename, O_WRONLY | O_CREAT, 0666);
346 if (fd < 0)
347 die_errno(_("Could not write to '%s'"), filename);
348
349 init_revisions(&rev, NULL);
350 rev.ignore_merges = 1;
351 rev.commit_format = CMIT_FMT_MEDIUM;
352
353 commit->object.flags |= UNINTERESTING;
354 add_pending_object(&rev, &commit->object, NULL);
355
356 for (j = remoteheads; j; j = j->next)
357 add_pending_object(&rev, &j->item->object, NULL);
358
359 setup_revisions(0, NULL, &rev, NULL);
360 if (prepare_revision_walk(&rev))
361 die(_("revision walk setup failed"));
362
363 ctx.abbrev = rev.abbrev;
364 ctx.date_mode = rev.date_mode;
365 ctx.fmt = rev.commit_format;
366
367 strbuf_addstr(&out, "Squashed commit of the following:\n");
368 while ((commit = get_revision(&rev)) != NULL) {
369 strbuf_addch(&out, '\n');
370 strbuf_addf(&out, "commit %s\n",
371 oid_to_hex(&commit->object.oid));
372 pretty_print_commit(&ctx, commit, &out);
373 }
374 if (write_in_full(fd, out.buf, out.len) != out.len)
375 die_errno(_("Writing SQUASH_MSG"));
376 if (close(fd))
377 die_errno(_("Finishing SQUASH_MSG"));
378 strbuf_release(&out);
379 }
380
381 static void finish(struct commit *head_commit,
382 struct commit_list *remoteheads,
383 const unsigned char *new_head, const char *msg)
384 {
385 struct strbuf reflog_message = STRBUF_INIT;
386 const unsigned char *head = head_commit->object.oid.hash;
387
388 if (!msg)
389 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
390 else {
391 if (verbosity >= 0)
392 printf("%s\n", msg);
393 strbuf_addf(&reflog_message, "%s: %s",
394 getenv("GIT_REFLOG_ACTION"), msg);
395 }
396 if (squash) {
397 squash_message(head_commit, remoteheads);
398 } else {
399 if (verbosity >= 0 && !merge_msg.len)
400 printf(_("No merge message -- not updating HEAD\n"));
401 else {
402 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
403 update_ref(reflog_message.buf, "HEAD",
404 new_head, head, 0,
405 UPDATE_REFS_DIE_ON_ERR);
406 /*
407 * We ignore errors in 'gc --auto', since the
408 * user should see them.
409 */
410 close_all_packs();
411 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
412 }
413 }
414 if (new_head && show_diffstat) {
415 struct diff_options opts;
416 diff_setup(&opts);
417 opts.stat_width = -1; /* use full terminal width */
418 opts.stat_graph_width = -1; /* respect statGraphWidth config */
419 opts.output_format |=
420 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
421 opts.detect_rename = DIFF_DETECT_RENAME;
422 diff_setup_done(&opts);
423 diff_tree_sha1(head, new_head, "", &opts);
424 diffcore_std(&opts);
425 diff_flush(&opts);
426 }
427
428 /* Run a post-merge hook */
429 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
430
431 strbuf_release(&reflog_message);
432 }
433
434 /* Get the name for the merge commit's message. */
435 static void merge_name(const char *remote, struct strbuf *msg)
436 {
437 struct commit *remote_head;
438 unsigned char branch_head[20];
439 struct strbuf buf = STRBUF_INIT;
440 struct strbuf bname = STRBUF_INIT;
441 const char *ptr;
442 char *found_ref;
443 int len, early;
444
445 strbuf_branchname(&bname, remote);
446 remote = bname.buf;
447
448 memset(branch_head, 0, sizeof(branch_head));
449 remote_head = get_merge_parent(remote);
450 if (!remote_head)
451 die(_("'%s' does not point to a commit"), remote);
452
453 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
454 if (starts_with(found_ref, "refs/heads/")) {
455 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
456 sha1_to_hex(branch_head), remote);
457 goto cleanup;
458 }
459 if (starts_with(found_ref, "refs/tags/")) {
460 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
461 sha1_to_hex(branch_head), remote);
462 goto cleanup;
463 }
464 if (starts_with(found_ref, "refs/remotes/")) {
465 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
466 sha1_to_hex(branch_head), remote);
467 goto cleanup;
468 }
469 }
470
471 /* See if remote matches <name>^^^.. or <name>~<number> */
472 for (len = 0, ptr = remote + strlen(remote);
473 remote < ptr && ptr[-1] == '^';
474 ptr--)
475 len++;
476 if (len)
477 early = 1;
478 else {
479 early = 0;
480 ptr = strrchr(remote, '~');
481 if (ptr) {
482 int seen_nonzero = 0;
483
484 len++; /* count ~ */
485 while (*++ptr && isdigit(*ptr)) {
486 seen_nonzero |= (*ptr != '0');
487 len++;
488 }
489 if (*ptr)
490 len = 0; /* not ...~<number> */
491 else if (seen_nonzero)
492 early = 1;
493 else if (len == 1)
494 early = 1; /* "name~" is "name~1"! */
495 }
496 }
497 if (len) {
498 struct strbuf truname = STRBUF_INIT;
499 strbuf_addf(&truname, "refs/heads/%s", remote);
500 strbuf_setlen(&truname, truname.len - len);
501 if (ref_exists(truname.buf)) {
502 strbuf_addf(msg,
503 "%s\t\tbranch '%s'%s of .\n",
504 sha1_to_hex(remote_head->object.oid.hash),
505 truname.buf + 11,
506 (early ? " (early part)" : ""));
507 strbuf_release(&truname);
508 goto cleanup;
509 }
510 strbuf_release(&truname);
511 }
512
513 if (remote_head->util) {
514 struct merge_remote_desc *desc;
515 desc = merge_remote_util(remote_head);
516 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
517 strbuf_addf(msg, "%s\t\t%s '%s'\n",
518 sha1_to_hex(desc->obj->oid.hash),
519 typename(desc->obj->type),
520 remote);
521 goto cleanup;
522 }
523 }
524
525 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
526 sha1_to_hex(remote_head->object.oid.hash), remote);
527 cleanup:
528 strbuf_release(&buf);
529 strbuf_release(&bname);
530 }
531
532 static void parse_branch_merge_options(char *bmo)
533 {
534 const char **argv;
535 int argc;
536
537 if (!bmo)
538 return;
539 argc = split_cmdline(bmo, &argv);
540 if (argc < 0)
541 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
542 split_cmdline_strerror(argc));
543 REALLOC_ARRAY(argv, argc + 2);
544 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
545 argc++;
546 argv[0] = "branch.*.mergeoptions";
547 parse_options(argc, argv, NULL, builtin_merge_options,
548 builtin_merge_usage, 0);
549 free(argv);
550 }
551
552 static int git_merge_config(const char *k, const char *v, void *cb)
553 {
554 int status;
555
556 if (branch && starts_with(k, "branch.") &&
557 starts_with(k + 7, branch) &&
558 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
559 free(branch_mergeoptions);
560 branch_mergeoptions = xstrdup(v);
561 return 0;
562 }
563
564 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
565 show_diffstat = git_config_bool(k, v);
566 else if (!strcmp(k, "pull.twohead"))
567 return git_config_string(&pull_twohead, k, v);
568 else if (!strcmp(k, "pull.octopus"))
569 return git_config_string(&pull_octopus, k, v);
570 else if (!strcmp(k, "merge.renormalize"))
571 option_renormalize = git_config_bool(k, v);
572 else if (!strcmp(k, "merge.ff")) {
573 int boolval = git_config_maybe_bool(k, v);
574 if (0 <= boolval) {
575 fast_forward = boolval ? FF_ALLOW : FF_NO;
576 } else if (v && !strcmp(v, "only")) {
577 fast_forward = FF_ONLY;
578 } /* do not barf on values from future versions of git */
579 return 0;
580 } else if (!strcmp(k, "merge.defaulttoupstream")) {
581 default_to_upstream = git_config_bool(k, v);
582 return 0;
583 } else if (!strcmp(k, "commit.gpgsign")) {
584 sign_commit = git_config_bool(k, v) ? "" : NULL;
585 return 0;
586 }
587
588 status = fmt_merge_msg_config(k, v, cb);
589 if (status)
590 return status;
591 status = git_gpg_config(k, v, NULL);
592 if (status)
593 return status;
594 return git_diff_ui_config(k, v, cb);
595 }
596
597 static int read_tree_trivial(unsigned char *common, unsigned char *head,
598 unsigned char *one)
599 {
600 int i, nr_trees = 0;
601 struct tree *trees[MAX_UNPACK_TREES];
602 struct tree_desc t[MAX_UNPACK_TREES];
603 struct unpack_trees_options opts;
604
605 memset(&opts, 0, sizeof(opts));
606 opts.head_idx = 2;
607 opts.src_index = &the_index;
608 opts.dst_index = &the_index;
609 opts.update = 1;
610 opts.verbose_update = 1;
611 opts.trivial_merges_only = 1;
612 opts.merge = 1;
613 trees[nr_trees] = parse_tree_indirect(common);
614 if (!trees[nr_trees++])
615 return -1;
616 trees[nr_trees] = parse_tree_indirect(head);
617 if (!trees[nr_trees++])
618 return -1;
619 trees[nr_trees] = parse_tree_indirect(one);
620 if (!trees[nr_trees++])
621 return -1;
622 opts.fn = threeway_merge;
623 cache_tree_free(&active_cache_tree);
624 for (i = 0; i < nr_trees; i++) {
625 parse_tree(trees[i]);
626 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
627 }
628 if (unpack_trees(nr_trees, t, &opts))
629 return -1;
630 return 0;
631 }
632
633 static void write_tree_trivial(unsigned char *sha1)
634 {
635 if (write_cache_as_tree(sha1, 0, NULL))
636 die(_("git write-tree failed to write a tree"));
637 }
638
639 static int try_merge_strategy(const char *strategy, struct commit_list *common,
640 struct commit_list *remoteheads,
641 struct commit *head, const char *head_arg)
642 {
643 static struct lock_file lock;
644
645 hold_locked_index(&lock, 1);
646 refresh_cache(REFRESH_QUIET);
647 if (active_cache_changed &&
648 write_locked_index(&the_index, &lock, COMMIT_LOCK))
649 return error(_("Unable to write index."));
650 rollback_lock_file(&lock);
651
652 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
653 int clean, x;
654 struct commit *result;
655 struct commit_list *reversed = NULL;
656 struct merge_options o;
657 struct commit_list *j;
658
659 if (remoteheads->next) {
660 error(_("Not handling anything other than two heads merge."));
661 return 2;
662 }
663
664 init_merge_options(&o);
665 if (!strcmp(strategy, "subtree"))
666 o.subtree_shift = "";
667
668 o.renormalize = option_renormalize;
669 o.show_rename_progress =
670 show_progress == -1 ? isatty(2) : show_progress;
671
672 for (x = 0; x < xopts_nr; x++)
673 if (parse_merge_opt(&o, xopts[x]))
674 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
675
676 o.branch1 = head_arg;
677 o.branch2 = merge_remote_util(remoteheads->item)->name;
678
679 for (j = common; j; j = j->next)
680 commit_list_insert(j->item, &reversed);
681
682 hold_locked_index(&lock, 1);
683 clean = merge_recursive(&o, head,
684 remoteheads->item, reversed, &result);
685 if (active_cache_changed &&
686 write_locked_index(&the_index, &lock, COMMIT_LOCK))
687 die (_("unable to write %s"), get_index_file());
688 rollback_lock_file(&lock);
689 return clean ? 0 : 1;
690 } else {
691 return try_merge_command(strategy, xopts_nr, xopts,
692 common, head_arg, remoteheads);
693 }
694 }
695
696 static void count_diff_files(struct diff_queue_struct *q,
697 struct diff_options *opt, void *data)
698 {
699 int *count = data;
700
701 (*count) += q->nr;
702 }
703
704 static int count_unmerged_entries(void)
705 {
706 int i, ret = 0;
707
708 for (i = 0; i < active_nr; i++)
709 if (ce_stage(active_cache[i]))
710 ret++;
711
712 return ret;
713 }
714
715 static void split_merge_strategies(const char *string, struct strategy **list,
716 int *nr, int *alloc)
717 {
718 char *p, *q, *buf;
719
720 if (!string)
721 return;
722
723 buf = xstrdup(string);
724 q = buf;
725 for (;;) {
726 p = strchr(q, ' ');
727 if (!p) {
728 ALLOC_GROW(*list, *nr + 1, *alloc);
729 (*list)[(*nr)++].name = xstrdup(q);
730 free(buf);
731 return;
732 } else {
733 *p = '\0';
734 ALLOC_GROW(*list, *nr + 1, *alloc);
735 (*list)[(*nr)++].name = xstrdup(q);
736 q = ++p;
737 }
738 }
739 }
740
741 static void add_strategies(const char *string, unsigned attr)
742 {
743 struct strategy *list = NULL;
744 int list_alloc = 0, list_nr = 0, i;
745
746 memset(&list, 0, sizeof(list));
747 split_merge_strategies(string, &list, &list_nr, &list_alloc);
748 if (list) {
749 for (i = 0; i < list_nr; i++)
750 append_strategy(get_strategy(list[i].name));
751 return;
752 }
753 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
754 if (all_strategy[i].attr & attr)
755 append_strategy(&all_strategy[i]);
756
757 }
758
759 static void write_merge_msg(struct strbuf *msg)
760 {
761 const char *filename = git_path_merge_msg();
762 int fd = open(filename, O_WRONLY | O_CREAT, 0666);
763 if (fd < 0)
764 die_errno(_("Could not open '%s' for writing"),
765 filename);
766 if (write_in_full(fd, msg->buf, msg->len) != msg->len)
767 die_errno(_("Could not write to '%s'"), filename);
768 close(fd);
769 }
770
771 static void read_merge_msg(struct strbuf *msg)
772 {
773 const char *filename = git_path_merge_msg();
774 strbuf_reset(msg);
775 if (strbuf_read_file(msg, filename, 0) < 0)
776 die_errno(_("Could not read from '%s'"), filename);
777 }
778
779 static void write_merge_state(struct commit_list *);
780 static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
781 {
782 if (err_msg)
783 error("%s", err_msg);
784 fprintf(stderr,
785 _("Not committing merge; use 'git commit' to complete the merge.\n"));
786 write_merge_state(remoteheads);
787 exit(1);
788 }
789
790 static const char merge_editor_comment[] =
791 N_("Please enter a commit message to explain why this merge is necessary,\n"
792 "especially if it merges an updated upstream into a topic branch.\n"
793 "\n"
794 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
795 "the commit.\n");
796
797 static void prepare_to_commit(struct commit_list *remoteheads)
798 {
799 struct strbuf msg = STRBUF_INIT;
800 strbuf_addbuf(&msg, &merge_msg);
801 strbuf_addch(&msg, '\n');
802 if (0 < option_edit)
803 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
804 write_merge_msg(&msg);
805 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
806 git_path_merge_msg(), "merge", NULL))
807 abort_commit(remoteheads, NULL);
808 if (0 < option_edit) {
809 if (launch_editor(git_path_merge_msg(), NULL, NULL))
810 abort_commit(remoteheads, NULL);
811 }
812 read_merge_msg(&msg);
813 strbuf_stripspace(&msg, 0 < option_edit);
814 if (!msg.len)
815 abort_commit(remoteheads, _("Empty commit message."));
816 strbuf_release(&merge_msg);
817 strbuf_addbuf(&merge_msg, &msg);
818 strbuf_release(&msg);
819 }
820
821 static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
822 {
823 unsigned char result_tree[20], result_commit[20];
824 struct commit_list *parents, **pptr = &parents;
825 static struct lock_file lock;
826
827 hold_locked_index(&lock, 1);
828 refresh_cache(REFRESH_QUIET);
829 if (active_cache_changed &&
830 write_locked_index(&the_index, &lock, COMMIT_LOCK))
831 return error(_("Unable to write index."));
832 rollback_lock_file(&lock);
833
834 write_tree_trivial(result_tree);
835 printf(_("Wonderful.\n"));
836 pptr = commit_list_append(head, pptr);
837 pptr = commit_list_append(remoteheads->item, pptr);
838 prepare_to_commit(remoteheads);
839 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
840 result_commit, NULL, sign_commit))
841 die(_("failed to write commit object"));
842 finish(head, remoteheads, result_commit, "In-index merge");
843 drop_save();
844 return 0;
845 }
846
847 static int finish_automerge(struct commit *head,
848 int head_subsumed,
849 struct commit_list *common,
850 struct commit_list *remoteheads,
851 unsigned char *result_tree,
852 const char *wt_strategy)
853 {
854 struct commit_list *parents = NULL;
855 struct strbuf buf = STRBUF_INIT;
856 unsigned char result_commit[20];
857
858 free_commit_list(common);
859 parents = remoteheads;
860 if (!head_subsumed || fast_forward == FF_NO)
861 commit_list_insert(head, &parents);
862 strbuf_addch(&merge_msg, '\n');
863 prepare_to_commit(remoteheads);
864 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
865 result_commit, NULL, sign_commit))
866 die(_("failed to write commit object"));
867 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
868 finish(head, remoteheads, result_commit, buf.buf);
869 strbuf_release(&buf);
870 drop_save();
871 return 0;
872 }
873
874 static int suggest_conflicts(void)
875 {
876 const char *filename;
877 FILE *fp;
878 struct strbuf msgbuf = STRBUF_INIT;
879
880 filename = git_path_merge_msg();
881 fp = fopen(filename, "a");
882 if (!fp)
883 die_errno(_("Could not open '%s' for writing"), filename);
884
885 append_conflicts_hint(&msgbuf);
886 fputs(msgbuf.buf, fp);
887 strbuf_release(&msgbuf);
888 fclose(fp);
889 rerere(allow_rerere_auto);
890 printf(_("Automatic merge failed; "
891 "fix conflicts and then commit the result.\n"));
892 return 1;
893 }
894
895 static struct commit *is_old_style_invocation(int argc, const char **argv,
896 const unsigned char *head)
897 {
898 struct commit *second_token = NULL;
899 if (argc > 2) {
900 unsigned char second_sha1[20];
901
902 if (get_sha1(argv[1], second_sha1))
903 return NULL;
904 second_token = lookup_commit_reference_gently(second_sha1, 0);
905 if (!second_token)
906 die(_("'%s' is not a commit"), argv[1]);
907 if (hashcmp(second_token->object.oid.hash, head))
908 return NULL;
909 }
910 return second_token;
911 }
912
913 static int evaluate_result(void)
914 {
915 int cnt = 0;
916 struct rev_info rev;
917
918 /* Check how many files differ. */
919 init_revisions(&rev, "");
920 setup_revisions(0, NULL, &rev, NULL);
921 rev.diffopt.output_format |=
922 DIFF_FORMAT_CALLBACK;
923 rev.diffopt.format_callback = count_diff_files;
924 rev.diffopt.format_callback_data = &cnt;
925 run_diff_files(&rev, 0);
926
927 /*
928 * Check how many unmerged entries are
929 * there.
930 */
931 cnt += count_unmerged_entries();
932
933 return cnt;
934 }
935
936 /*
937 * Pretend as if the user told us to merge with the remote-tracking
938 * branch we have for the upstream of the current branch
939 */
940 static int setup_with_upstream(const char ***argv)
941 {
942 struct branch *branch = branch_get(NULL);
943 int i;
944 const char **args;
945
946 if (!branch)
947 die(_("No current branch."));
948 if (!branch->remote_name)
949 die(_("No remote for the current branch."));
950 if (!branch->merge_nr)
951 die(_("No default upstream defined for the current branch."));
952
953 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
954 for (i = 0; i < branch->merge_nr; i++) {
955 if (!branch->merge[i]->dst)
956 die(_("No remote-tracking branch for %s from %s"),
957 branch->merge[i]->src, branch->remote_name);
958 args[i] = branch->merge[i]->dst;
959 }
960 args[i] = NULL;
961 *argv = args;
962 return i;
963 }
964
965 static void write_merge_state(struct commit_list *remoteheads)
966 {
967 const char *filename;
968 int fd;
969 struct commit_list *j;
970 struct strbuf buf = STRBUF_INIT;
971
972 for (j = remoteheads; j; j = j->next) {
973 struct object_id *oid;
974 struct commit *c = j->item;
975 if (c->util && merge_remote_util(c)->obj) {
976 oid = &merge_remote_util(c)->obj->oid;
977 } else {
978 oid = &c->object.oid;
979 }
980 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
981 }
982 filename = git_path_merge_head();
983 fd = open(filename, O_WRONLY | O_CREAT, 0666);
984 if (fd < 0)
985 die_errno(_("Could not open '%s' for writing"), filename);
986 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
987 die_errno(_("Could not write to '%s'"), filename);
988 close(fd);
989 strbuf_addch(&merge_msg, '\n');
990 write_merge_msg(&merge_msg);
991
992 filename = git_path_merge_mode();
993 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
994 if (fd < 0)
995 die_errno(_("Could not open '%s' for writing"), filename);
996 strbuf_reset(&buf);
997 if (fast_forward == FF_NO)
998 strbuf_addf(&buf, "no-ff");
999 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1000 die_errno(_("Could not write to '%s'"), filename);
1001 close(fd);
1002 }
1003
1004 static int default_edit_option(void)
1005 {
1006 static const char name[] = "GIT_MERGE_AUTOEDIT";
1007 const char *e = getenv(name);
1008 struct stat st_stdin, st_stdout;
1009
1010 if (have_message)
1011 /* an explicit -m msg without --[no-]edit */
1012 return 0;
1013
1014 if (e) {
1015 int v = git_config_maybe_bool(name, e);
1016 if (v < 0)
1017 die("Bad value '%s' in environment '%s'", e, name);
1018 return v;
1019 }
1020
1021 /* Use editor if stdin and stdout are the same and is a tty */
1022 return (!fstat(0, &st_stdin) &&
1023 !fstat(1, &st_stdout) &&
1024 isatty(0) && isatty(1) &&
1025 st_stdin.st_dev == st_stdout.st_dev &&
1026 st_stdin.st_ino == st_stdout.st_ino &&
1027 st_stdin.st_mode == st_stdout.st_mode);
1028 }
1029
1030 static struct commit_list *reduce_parents(struct commit *head_commit,
1031 int *head_subsumed,
1032 struct commit_list *remoteheads)
1033 {
1034 struct commit_list *parents, **remotes;
1035
1036 /*
1037 * Is the current HEAD reachable from another commit being
1038 * merged? If so we do not want to record it as a parent of
1039 * the resulting merge, unless --no-ff is given. We will flip
1040 * this variable to 0 when we find HEAD among the independent
1041 * tips being merged.
1042 */
1043 *head_subsumed = 1;
1044
1045 /* Find what parents to record by checking independent ones. */
1046 parents = reduce_heads(remoteheads);
1047
1048 remoteheads = NULL;
1049 remotes = &remoteheads;
1050 while (parents) {
1051 struct commit *commit = pop_commit(&parents);
1052 if (commit == head_commit)
1053 *head_subsumed = 0;
1054 else
1055 remotes = &commit_list_insert(commit, remotes)->next;
1056 }
1057 return remoteheads;
1058 }
1059
1060 static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1061 {
1062 struct fmt_merge_msg_opts opts;
1063
1064 memset(&opts, 0, sizeof(opts));
1065 opts.add_title = !have_message;
1066 opts.shortlog_len = shortlog_len;
1067 opts.credit_people = (0 < option_edit);
1068
1069 fmt_merge_msg(merge_names, merge_msg, &opts);
1070 if (merge_msg->len)
1071 strbuf_setlen(merge_msg, merge_msg->len - 1);
1072 }
1073
1074 static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1075 {
1076 const char *filename;
1077 int fd, pos, npos;
1078 struct strbuf fetch_head_file = STRBUF_INIT;
1079
1080 if (!merge_names)
1081 merge_names = &fetch_head_file;
1082
1083 filename = git_path_fetch_head();
1084 fd = open(filename, O_RDONLY);
1085 if (fd < 0)
1086 die_errno(_("could not open '%s' for reading"), filename);
1087
1088 if (strbuf_read(merge_names, fd, 0) < 0)
1089 die_errno(_("could not read '%s'"), filename);
1090 if (close(fd) < 0)
1091 die_errno(_("could not close '%s'"), filename);
1092
1093 for (pos = 0; pos < merge_names->len; pos = npos) {
1094 unsigned char sha1[20];
1095 char *ptr;
1096 struct commit *commit;
1097
1098 ptr = strchr(merge_names->buf + pos, '\n');
1099 if (ptr)
1100 npos = ptr - merge_names->buf + 1;
1101 else
1102 npos = merge_names->len;
1103
1104 if (npos - pos < 40 + 2 ||
1105 get_sha1_hex(merge_names->buf + pos, sha1))
1106 commit = NULL; /* bad */
1107 else if (memcmp(merge_names->buf + pos + 40, "\t\t", 2))
1108 continue; /* not-for-merge */
1109 else {
1110 char saved = merge_names->buf[pos + 40];
1111 merge_names->buf[pos + 40] = '\0';
1112 commit = get_merge_parent(merge_names->buf + pos);
1113 merge_names->buf[pos + 40] = saved;
1114 }
1115 if (!commit) {
1116 if (ptr)
1117 *ptr = '\0';
1118 die("not something we can merge in %s: %s",
1119 filename, merge_names->buf + pos);
1120 }
1121 remotes = &commit_list_insert(commit, remotes)->next;
1122 }
1123
1124 if (merge_names == &fetch_head_file)
1125 strbuf_release(&fetch_head_file);
1126 }
1127
1128 static struct commit_list *collect_parents(struct commit *head_commit,
1129 int *head_subsumed,
1130 int argc, const char **argv,
1131 struct strbuf *merge_msg)
1132 {
1133 int i;
1134 struct commit_list *remoteheads = NULL;
1135 struct commit_list **remotes = &remoteheads;
1136 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1137
1138 if (merge_msg && (!have_message || shortlog_len))
1139 autogen = &merge_names;
1140
1141 if (head_commit)
1142 remotes = &commit_list_insert(head_commit, remotes)->next;
1143
1144 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1145 handle_fetch_head(remotes, autogen);
1146 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1147 } else {
1148 for (i = 0; i < argc; i++) {
1149 struct commit *commit = get_merge_parent(argv[i]);
1150 if (!commit)
1151 help_unknown_ref(argv[i], "merge",
1152 "not something we can merge");
1153 remotes = &commit_list_insert(commit, remotes)->next;
1154 }
1155 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1156 if (autogen) {
1157 struct commit_list *p;
1158 for (p = remoteheads; p; p = p->next)
1159 merge_name(merge_remote_util(p->item)->name, autogen);
1160 }
1161 }
1162
1163 if (autogen) {
1164 prepare_merge_message(autogen, merge_msg);
1165 strbuf_release(autogen);
1166 }
1167
1168 return remoteheads;
1169 }
1170
1171 int cmd_merge(int argc, const char **argv, const char *prefix)
1172 {
1173 unsigned char result_tree[20];
1174 unsigned char stash[20];
1175 unsigned char head_sha1[20];
1176 struct commit *head_commit;
1177 struct strbuf buf = STRBUF_INIT;
1178 const char *head_arg;
1179 int i, ret = 0, head_subsumed;
1180 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1181 struct commit_list *common = NULL;
1182 const char *best_strategy = NULL, *wt_strategy = NULL;
1183 struct commit_list *remoteheads, *p;
1184 void *branch_to_free;
1185
1186 if (argc == 2 && !strcmp(argv[1], "-h"))
1187 usage_with_options(builtin_merge_usage, builtin_merge_options);
1188
1189 /*
1190 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1191 * current branch.
1192 */
1193 branch = branch_to_free = resolve_refdup("HEAD", 0, head_sha1, NULL);
1194 if (branch && starts_with(branch, "refs/heads/"))
1195 branch += 11;
1196 if (!branch || is_null_sha1(head_sha1))
1197 head_commit = NULL;
1198 else
1199 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1200
1201 init_diff_ui_defaults();
1202 git_config(git_merge_config, NULL);
1203
1204 if (branch_mergeoptions)
1205 parse_branch_merge_options(branch_mergeoptions);
1206 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1207 builtin_merge_usage, 0);
1208 if (shortlog_len < 0)
1209 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1210
1211 if (verbosity < 0 && show_progress == -1)
1212 show_progress = 0;
1213
1214 if (abort_current_merge) {
1215 int nargc = 2;
1216 const char *nargv[] = {"reset", "--merge", NULL};
1217
1218 if (!file_exists(git_path_merge_head()))
1219 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1220
1221 /* Invoke 'git reset --merge' */
1222 ret = cmd_reset(nargc, nargv, prefix);
1223 goto done;
1224 }
1225
1226 if (read_cache_unmerged())
1227 die_resolve_conflict("merge");
1228
1229 if (file_exists(git_path_merge_head())) {
1230 /*
1231 * There is no unmerged entry, don't advise 'git
1232 * add/rm <file>', just 'git commit'.
1233 */
1234 if (advice_resolve_conflict)
1235 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1236 "Please, commit your changes before you merge."));
1237 else
1238 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1239 }
1240 if (file_exists(git_path_cherry_pick_head())) {
1241 if (advice_resolve_conflict)
1242 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1243 "Please, commit your changes before you merge."));
1244 else
1245 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1246 }
1247 resolve_undo_clear();
1248
1249 if (verbosity < 0)
1250 show_diffstat = 0;
1251
1252 if (squash) {
1253 if (fast_forward == FF_NO)
1254 die(_("You cannot combine --squash with --no-ff."));
1255 option_commit = 0;
1256 }
1257
1258 if (!argc) {
1259 if (default_to_upstream)
1260 argc = setup_with_upstream(&argv);
1261 else
1262 die(_("No commit specified and merge.defaultToUpstream not set."));
1263 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1264 argv[0] = "@{-1}";
1265 }
1266
1267 if (!argc)
1268 usage_with_options(builtin_merge_usage,
1269 builtin_merge_options);
1270
1271 if (!head_commit) {
1272 /*
1273 * If the merged head is a valid one there is no reason
1274 * to forbid "git merge" into a branch yet to be born.
1275 * We do the same for "git pull".
1276 */
1277 unsigned char *remote_head_sha1;
1278 if (squash)
1279 die(_("Squash commit into empty head not supported yet"));
1280 if (fast_forward == FF_NO)
1281 die(_("Non-fast-forward commit does not make sense into "
1282 "an empty head"));
1283 remoteheads = collect_parents(head_commit, &head_subsumed,
1284 argc, argv, NULL);
1285 if (!remoteheads)
1286 die(_("%s - not something we can merge"), argv[0]);
1287 if (remoteheads->next)
1288 die(_("Can merge only exactly one commit into empty head"));
1289 remote_head_sha1 = remoteheads->item->object.oid.hash;
1290 read_empty(remote_head_sha1, 0);
1291 update_ref("initial pull", "HEAD", remote_head_sha1,
1292 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1293 goto done;
1294 }
1295
1296 /*
1297 * This could be traditional "merge <msg> HEAD <commit>..." and
1298 * the way we can tell it is to see if the second token is HEAD,
1299 * but some people might have misused the interface and used a
1300 * commit-ish that is the same as HEAD there instead.
1301 * Traditional format never would have "-m" so it is an
1302 * additional safety measure to check for it.
1303 */
1304 if (!have_message &&
1305 is_old_style_invocation(argc, argv, head_commit->object.oid.hash)) {
1306 warning("old-style 'git merge <msg> HEAD <commit>' is deprecated.");
1307 strbuf_addstr(&merge_msg, argv[0]);
1308 head_arg = argv[1];
1309 argv += 2;
1310 argc -= 2;
1311 remoteheads = collect_parents(head_commit, &head_subsumed,
1312 argc, argv, NULL);
1313 } else {
1314 /* We are invoked directly as the first-class UI. */
1315 head_arg = "HEAD";
1316
1317 /*
1318 * All the rest are the commits being merged; prepare
1319 * the standard merge summary message to be appended
1320 * to the given message.
1321 */
1322 remoteheads = collect_parents(head_commit, &head_subsumed,
1323 argc, argv, &merge_msg);
1324 }
1325
1326 if (!head_commit || !argc)
1327 usage_with_options(builtin_merge_usage,
1328 builtin_merge_options);
1329
1330 if (verify_signatures) {
1331 for (p = remoteheads; p; p = p->next) {
1332 struct commit *commit = p->item;
1333 char hex[GIT_SHA1_HEXSZ + 1];
1334 struct signature_check signature_check;
1335 memset(&signature_check, 0, sizeof(signature_check));
1336
1337 check_commit_signature(commit, &signature_check);
1338
1339 find_unique_abbrev_r(hex, commit->object.oid.hash, DEFAULT_ABBREV);
1340 switch (signature_check.result) {
1341 case 'G':
1342 break;
1343 case 'U':
1344 die(_("Commit %s has an untrusted GPG signature, "
1345 "allegedly by %s."), hex, signature_check.signer);
1346 case 'B':
1347 die(_("Commit %s has a bad GPG signature "
1348 "allegedly by %s."), hex, signature_check.signer);
1349 default: /* 'N' */
1350 die(_("Commit %s does not have a GPG signature."), hex);
1351 }
1352 if (verbosity >= 0 && signature_check.result == 'G')
1353 printf(_("Commit %s has a good GPG signature by %s\n"),
1354 hex, signature_check.signer);
1355
1356 signature_check_clear(&signature_check);
1357 }
1358 }
1359
1360 strbuf_addstr(&buf, "merge");
1361 for (p = remoteheads; p; p = p->next)
1362 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1363 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1364 strbuf_reset(&buf);
1365
1366 for (p = remoteheads; p; p = p->next) {
1367 struct commit *commit = p->item;
1368 strbuf_addf(&buf, "GITHEAD_%s",
1369 sha1_to_hex(commit->object.oid.hash));
1370 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1371 strbuf_reset(&buf);
1372 if (fast_forward != FF_ONLY &&
1373 merge_remote_util(commit) &&
1374 merge_remote_util(commit)->obj &&
1375 merge_remote_util(commit)->obj->type == OBJ_TAG)
1376 fast_forward = FF_NO;
1377 }
1378
1379 if (option_edit < 0)
1380 option_edit = default_edit_option();
1381
1382 if (!use_strategies) {
1383 if (!remoteheads)
1384 ; /* already up-to-date */
1385 else if (!remoteheads->next)
1386 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1387 else
1388 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1389 }
1390
1391 for (i = 0; i < use_strategies_nr; i++) {
1392 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1393 fast_forward = FF_NO;
1394 if (use_strategies[i]->attr & NO_TRIVIAL)
1395 allow_trivial = 0;
1396 }
1397
1398 if (!remoteheads)
1399 ; /* already up-to-date */
1400 else if (!remoteheads->next)
1401 common = get_merge_bases(head_commit, remoteheads->item);
1402 else {
1403 struct commit_list *list = remoteheads;
1404 commit_list_insert(head_commit, &list);
1405 common = get_octopus_merge_bases(list);
1406 free(list);
1407 }
1408
1409 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.oid.hash,
1410 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1411
1412 if (remoteheads && !common) {
1413 /* No common ancestors found. */
1414 if (!allow_unrelated_histories)
1415 die(_("refusing to merge unrelated histories"));
1416 /* otherwise, we need a real merge. */
1417 } else if (!remoteheads ||
1418 (!remoteheads->next && !common->next &&
1419 common->item == remoteheads->item)) {
1420 /*
1421 * If head can reach all the merge then we are up to date.
1422 * but first the most common case of merging one remote.
1423 */
1424 finish_up_to_date("Already up-to-date.");
1425 goto done;
1426 } else if (fast_forward != FF_NO && !remoteheads->next &&
1427 !common->next &&
1428 !hashcmp(common->item->object.oid.hash, head_commit->object.oid.hash)) {
1429 /* Again the most common case of merging one remote. */
1430 struct strbuf msg = STRBUF_INIT;
1431 struct commit *commit;
1432
1433 if (verbosity >= 0) {
1434 char from[GIT_SHA1_HEXSZ + 1], to[GIT_SHA1_HEXSZ + 1];
1435 find_unique_abbrev_r(from, head_commit->object.oid.hash,
1436 DEFAULT_ABBREV);
1437 find_unique_abbrev_r(to, remoteheads->item->object.oid.hash,
1438 DEFAULT_ABBREV);
1439 printf(_("Updating %s..%s\n"), from, to);
1440 }
1441 strbuf_addstr(&msg, "Fast-forward");
1442 if (have_message)
1443 strbuf_addstr(&msg,
1444 " (no commit created; -m option ignored)");
1445 commit = remoteheads->item;
1446 if (!commit) {
1447 ret = 1;
1448 goto done;
1449 }
1450
1451 if (checkout_fast_forward(head_commit->object.oid.hash,
1452 commit->object.oid.hash,
1453 overwrite_ignore)) {
1454 ret = 1;
1455 goto done;
1456 }
1457
1458 finish(head_commit, remoteheads, commit->object.oid.hash, msg.buf);
1459 drop_save();
1460 goto done;
1461 } else if (!remoteheads->next && common->next)
1462 ;
1463 /*
1464 * We are not doing octopus and not fast-forward. Need
1465 * a real merge.
1466 */
1467 else if (!remoteheads->next && !common->next && option_commit) {
1468 /*
1469 * We are not doing octopus, not fast-forward, and have
1470 * only one common.
1471 */
1472 refresh_cache(REFRESH_QUIET);
1473 if (allow_trivial && fast_forward != FF_ONLY) {
1474 /* See if it is really trivial. */
1475 git_committer_info(IDENT_STRICT);
1476 printf(_("Trying really trivial in-index merge...\n"));
1477 if (!read_tree_trivial(common->item->object.oid.hash,
1478 head_commit->object.oid.hash,
1479 remoteheads->item->object.oid.hash)) {
1480 ret = merge_trivial(head_commit, remoteheads);
1481 goto done;
1482 }
1483 printf(_("Nope.\n"));
1484 }
1485 } else {
1486 /*
1487 * An octopus. If we can reach all the remote we are up
1488 * to date.
1489 */
1490 int up_to_date = 1;
1491 struct commit_list *j;
1492
1493 for (j = remoteheads; j; j = j->next) {
1494 struct commit_list *common_one;
1495
1496 /*
1497 * Here we *have* to calculate the individual
1498 * merge_bases again, otherwise "git merge HEAD^
1499 * HEAD^^" would be missed.
1500 */
1501 common_one = get_merge_bases(head_commit, j->item);
1502 if (hashcmp(common_one->item->object.oid.hash,
1503 j->item->object.oid.hash)) {
1504 up_to_date = 0;
1505 break;
1506 }
1507 }
1508 if (up_to_date) {
1509 finish_up_to_date("Already up-to-date. Yeeah!");
1510 goto done;
1511 }
1512 }
1513
1514 if (fast_forward == FF_ONLY)
1515 die(_("Not possible to fast-forward, aborting."));
1516
1517 /* We are going to make a new commit. */
1518 git_committer_info(IDENT_STRICT);
1519
1520 /*
1521 * At this point, we need a real merge. No matter what strategy
1522 * we use, it would operate on the index, possibly affecting the
1523 * working tree, and when resolved cleanly, have the desired
1524 * tree in the index -- this means that the index must be in
1525 * sync with the head commit. The strategies are responsible
1526 * to ensure this.
1527 */
1528 if (use_strategies_nr == 1 ||
1529 /*
1530 * Stash away the local changes so that we can try more than one.
1531 */
1532 save_state(stash))
1533 hashcpy(stash, null_sha1);
1534
1535 for (i = 0; i < use_strategies_nr; i++) {
1536 int ret;
1537 if (i) {
1538 printf(_("Rewinding the tree to pristine...\n"));
1539 restore_state(head_commit->object.oid.hash, stash);
1540 }
1541 if (use_strategies_nr != 1)
1542 printf(_("Trying merge strategy %s...\n"),
1543 use_strategies[i]->name);
1544 /*
1545 * Remember which strategy left the state in the working
1546 * tree.
1547 */
1548 wt_strategy = use_strategies[i]->name;
1549
1550 ret = try_merge_strategy(use_strategies[i]->name,
1551 common, remoteheads,
1552 head_commit, head_arg);
1553 if (!option_commit && !ret) {
1554 merge_was_ok = 1;
1555 /*
1556 * This is necessary here just to avoid writing
1557 * the tree, but later we will *not* exit with
1558 * status code 1 because merge_was_ok is set.
1559 */
1560 ret = 1;
1561 }
1562
1563 if (ret) {
1564 /*
1565 * The backend exits with 1 when conflicts are
1566 * left to be resolved, with 2 when it does not
1567 * handle the given merge at all.
1568 */
1569 if (ret == 1) {
1570 int cnt = evaluate_result();
1571
1572 if (best_cnt <= 0 || cnt <= best_cnt) {
1573 best_strategy = use_strategies[i]->name;
1574 best_cnt = cnt;
1575 }
1576 }
1577 if (merge_was_ok)
1578 break;
1579 else
1580 continue;
1581 }
1582
1583 /* Automerge succeeded. */
1584 write_tree_trivial(result_tree);
1585 automerge_was_ok = 1;
1586 break;
1587 }
1588
1589 /*
1590 * If we have a resulting tree, that means the strategy module
1591 * auto resolved the merge cleanly.
1592 */
1593 if (automerge_was_ok) {
1594 ret = finish_automerge(head_commit, head_subsumed,
1595 common, remoteheads,
1596 result_tree, wt_strategy);
1597 goto done;
1598 }
1599
1600 /*
1601 * Pick the result from the best strategy and have the user fix
1602 * it up.
1603 */
1604 if (!best_strategy) {
1605 restore_state(head_commit->object.oid.hash, stash);
1606 if (use_strategies_nr > 1)
1607 fprintf(stderr,
1608 _("No merge strategy handled the merge.\n"));
1609 else
1610 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1611 use_strategies[0]->name);
1612 ret = 2;
1613 goto done;
1614 } else if (best_strategy == wt_strategy)
1615 ; /* We already have its result in the working tree. */
1616 else {
1617 printf(_("Rewinding the tree to pristine...\n"));
1618 restore_state(head_commit->object.oid.hash, stash);
1619 printf(_("Using the %s to prepare resolving by hand.\n"),
1620 best_strategy);
1621 try_merge_strategy(best_strategy, common, remoteheads,
1622 head_commit, head_arg);
1623 }
1624
1625 if (squash)
1626 finish(head_commit, remoteheads, NULL, NULL);
1627 else
1628 write_merge_state(remoteheads);
1629
1630 if (merge_was_ok)
1631 fprintf(stderr, _("Automatic merge went well; "
1632 "stopped before committing as requested\n"));
1633 else
1634 ret = suggest_conflicts();
1635
1636 done:
1637 free(branch_to_free);
1638 return ret;
1639 }