Merge branch 'maint-1.7.3' 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 "run-command.h"
13 #include "diff.h"
14 #include "refs.h"
15 #include "commit.h"
16 #include "diffcore.h"
17 #include "revision.h"
18 #include "unpack-trees.h"
19 #include "cache-tree.h"
20 #include "dir.h"
21 #include "utf8.h"
22 #include "log-tree.h"
23 #include "color.h"
24 #include "rerere.h"
25 #include "help.h"
26 #include "merge-recursive.h"
27 #include "resolve-undo.h"
28 #include "remote.h"
29
30 #define DEFAULT_TWOHEAD (1<<0)
31 #define DEFAULT_OCTOPUS (1<<1)
32 #define NO_FAST_FORWARD (1<<2)
33 #define NO_TRIVIAL (1<<3)
34
35 struct strategy {
36 const char *name;
37 unsigned attr;
38 };
39
40 static const char * const builtin_merge_usage[] = {
41 "git merge [options] [<commit>...]",
42 "git merge [options] <msg> HEAD <commit>",
43 "git merge --abort",
44 NULL
45 };
46
47 static int show_diffstat = 1, shortlog_len, squash;
48 static int option_commit = 1, allow_fast_forward = 1;
49 static int fast_forward_only;
50 static int allow_trivial = 1, have_message;
51 static struct strbuf merge_msg;
52 static struct commit_list *remoteheads;
53 static struct strategy **use_strategies;
54 static size_t use_strategies_nr, use_strategies_alloc;
55 static const char **xopts;
56 static size_t xopts_nr, xopts_alloc;
57 static const char *branch;
58 static char *branch_mergeoptions;
59 static int option_renormalize;
60 static int verbosity;
61 static int allow_rerere_auto;
62 static int abort_current_merge;
63 static int show_progress = -1;
64 static int default_to_upstream;
65
66 static struct strategy all_strategy[] = {
67 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
68 { "octopus", DEFAULT_OCTOPUS },
69 { "resolve", 0 },
70 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
71 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
72 };
73
74 static const char *pull_twohead, *pull_octopus;
75
76 static int option_parse_message(const struct option *opt,
77 const char *arg, int unset)
78 {
79 struct strbuf *buf = opt->value;
80
81 if (unset)
82 strbuf_setlen(buf, 0);
83 else if (arg) {
84 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
85 have_message = 1;
86 } else
87 return error(_("switch `m' requires a value"));
88 return 0;
89 }
90
91 static struct strategy *get_strategy(const char *name)
92 {
93 int i;
94 struct strategy *ret;
95 static struct cmdnames main_cmds, other_cmds;
96 static int loaded;
97
98 if (!name)
99 return NULL;
100
101 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
102 if (!strcmp(name, all_strategy[i].name))
103 return &all_strategy[i];
104
105 if (!loaded) {
106 struct cmdnames not_strategies;
107 loaded = 1;
108
109 memset(&not_strategies, 0, sizeof(struct cmdnames));
110 load_command_list("git-merge-", &main_cmds, &other_cmds);
111 for (i = 0; i < main_cmds.cnt; i++) {
112 int j, found = 0;
113 struct cmdname *ent = main_cmds.names[i];
114 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
115 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
116 && !all_strategy[j].name[ent->len])
117 found = 1;
118 if (!found)
119 add_cmdname(&not_strategies, ent->name, ent->len);
120 }
121 exclude_cmds(&main_cmds, &not_strategies);
122 }
123 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
124 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
125 fprintf(stderr, _("Available strategies are:"));
126 for (i = 0; i < main_cmds.cnt; i++)
127 fprintf(stderr, " %s", main_cmds.names[i]->name);
128 fprintf(stderr, ".\n");
129 if (other_cmds.cnt) {
130 fprintf(stderr, _("Available custom strategies are:"));
131 for (i = 0; i < other_cmds.cnt; i++)
132 fprintf(stderr, " %s", other_cmds.names[i]->name);
133 fprintf(stderr, ".\n");
134 }
135 exit(1);
136 }
137
138 ret = xcalloc(1, sizeof(struct strategy));
139 ret->name = xstrdup(name);
140 ret->attr = NO_TRIVIAL;
141 return ret;
142 }
143
144 static void append_strategy(struct strategy *s)
145 {
146 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
147 use_strategies[use_strategies_nr++] = s;
148 }
149
150 static int option_parse_strategy(const struct option *opt,
151 const char *name, int unset)
152 {
153 if (unset)
154 return 0;
155
156 append_strategy(get_strategy(name));
157 return 0;
158 }
159
160 static int option_parse_x(const struct option *opt,
161 const char *arg, int unset)
162 {
163 if (unset)
164 return 0;
165
166 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
167 xopts[xopts_nr++] = xstrdup(arg);
168 return 0;
169 }
170
171 static int option_parse_n(const struct option *opt,
172 const char *arg, int unset)
173 {
174 show_diffstat = unset;
175 return 0;
176 }
177
178 static struct option builtin_merge_options[] = {
179 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
180 "do not show a diffstat at the end of the merge",
181 PARSE_OPT_NOARG, option_parse_n },
182 OPT_BOOLEAN(0, "stat", &show_diffstat,
183 "show a diffstat at the end of the merge"),
184 OPT_BOOLEAN(0, "summary", &show_diffstat, "(synonym to --stat)"),
185 { OPTION_INTEGER, 0, "log", &shortlog_len, "n",
186 "add (at most <n>) entries from shortlog to merge commit message",
187 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
188 OPT_BOOLEAN(0, "squash", &squash,
189 "create a single commit instead of doing a merge"),
190 OPT_BOOLEAN(0, "commit", &option_commit,
191 "perform a commit if the merge succeeds (default)"),
192 OPT_BOOLEAN(0, "ff", &allow_fast_forward,
193 "allow fast-forward (default)"),
194 OPT_BOOLEAN(0, "ff-only", &fast_forward_only,
195 "abort if fast-forward is not possible"),
196 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
197 OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
198 "merge strategy to use", option_parse_strategy),
199 OPT_CALLBACK('X', "strategy-option", &xopts, "option=value",
200 "option for selected merge strategy", option_parse_x),
201 OPT_CALLBACK('m', "message", &merge_msg, "message",
202 "merge commit message (for a non-fast-forward merge)",
203 option_parse_message),
204 OPT__VERBOSITY(&verbosity),
205 OPT_BOOLEAN(0, "abort", &abort_current_merge,
206 "abort the current in-progress merge"),
207 OPT_SET_INT(0, "progress", &show_progress, "force progress reporting", 1),
208 OPT_END()
209 };
210
211 /* Cleans up metadata that is uninteresting after a succeeded merge. */
212 static void drop_save(void)
213 {
214 unlink(git_path("MERGE_HEAD"));
215 unlink(git_path("MERGE_MSG"));
216 unlink(git_path("MERGE_MODE"));
217 }
218
219 static int save_state(unsigned char *stash)
220 {
221 int len;
222 struct child_process cp;
223 struct strbuf buffer = STRBUF_INIT;
224 const char *argv[] = {"stash", "create", NULL};
225
226 memset(&cp, 0, sizeof(cp));
227 cp.argv = argv;
228 cp.out = -1;
229 cp.git_cmd = 1;
230
231 if (start_command(&cp))
232 die(_("could not run stash."));
233 len = strbuf_read(&buffer, cp.out, 1024);
234 close(cp.out);
235
236 if (finish_command(&cp) || len < 0)
237 die(_("stash failed"));
238 else if (!len) /* no changes */
239 return -1;
240 strbuf_setlen(&buffer, buffer.len-1);
241 if (get_sha1(buffer.buf, stash))
242 die(_("not a valid object: %s"), buffer.buf);
243 return 0;
244 }
245
246 static void read_empty(unsigned const char *sha1, int verbose)
247 {
248 int i = 0;
249 const char *args[7];
250
251 args[i++] = "read-tree";
252 if (verbose)
253 args[i++] = "-v";
254 args[i++] = "-m";
255 args[i++] = "-u";
256 args[i++] = EMPTY_TREE_SHA1_HEX;
257 args[i++] = sha1_to_hex(sha1);
258 args[i] = NULL;
259
260 if (run_command_v_opt(args, RUN_GIT_CMD))
261 die(_("read-tree failed"));
262 }
263
264 static void reset_hard(unsigned const char *sha1, int verbose)
265 {
266 int i = 0;
267 const char *args[6];
268
269 args[i++] = "read-tree";
270 if (verbose)
271 args[i++] = "-v";
272 args[i++] = "--reset";
273 args[i++] = "-u";
274 args[i++] = sha1_to_hex(sha1);
275 args[i] = NULL;
276
277 if (run_command_v_opt(args, RUN_GIT_CMD))
278 die(_("read-tree failed"));
279 }
280
281 static void restore_state(const unsigned char *head,
282 const unsigned char *stash)
283 {
284 struct strbuf sb = STRBUF_INIT;
285 const char *args[] = { "stash", "apply", NULL, NULL };
286
287 if (is_null_sha1(stash))
288 return;
289
290 reset_hard(head, 1);
291
292 args[2] = sha1_to_hex(stash);
293
294 /*
295 * It is OK to ignore error here, for example when there was
296 * nothing to restore.
297 */
298 run_command_v_opt(args, RUN_GIT_CMD);
299
300 strbuf_release(&sb);
301 refresh_cache(REFRESH_QUIET);
302 }
303
304 /* This is called when no merge was necessary. */
305 static void finish_up_to_date(const char *msg)
306 {
307 if (verbosity >= 0)
308 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
309 drop_save();
310 }
311
312 static void squash_message(struct commit *commit)
313 {
314 struct rev_info rev;
315 struct strbuf out = STRBUF_INIT;
316 struct commit_list *j;
317 int fd;
318 struct pretty_print_context ctx = {0};
319
320 printf(_("Squash commit -- not updating HEAD\n"));
321 fd = open(git_path("SQUASH_MSG"), O_WRONLY | O_CREAT, 0666);
322 if (fd < 0)
323 die_errno(_("Could not write to '%s'"), git_path("SQUASH_MSG"));
324
325 init_revisions(&rev, NULL);
326 rev.ignore_merges = 1;
327 rev.commit_format = CMIT_FMT_MEDIUM;
328
329 commit->object.flags |= UNINTERESTING;
330 add_pending_object(&rev, &commit->object, NULL);
331
332 for (j = remoteheads; j; j = j->next)
333 add_pending_object(&rev, &j->item->object, NULL);
334
335 setup_revisions(0, NULL, &rev, NULL);
336 if (prepare_revision_walk(&rev))
337 die(_("revision walk setup failed"));
338
339 ctx.abbrev = rev.abbrev;
340 ctx.date_mode = rev.date_mode;
341 ctx.fmt = rev.commit_format;
342
343 strbuf_addstr(&out, "Squashed commit of the following:\n");
344 while ((commit = get_revision(&rev)) != NULL) {
345 strbuf_addch(&out, '\n');
346 strbuf_addf(&out, "commit %s\n",
347 sha1_to_hex(commit->object.sha1));
348 pretty_print_commit(&ctx, commit, &out);
349 }
350 if (write(fd, out.buf, out.len) < 0)
351 die_errno(_("Writing SQUASH_MSG"));
352 if (close(fd))
353 die_errno(_("Finishing SQUASH_MSG"));
354 strbuf_release(&out);
355 }
356
357 static void finish(struct commit *head_commit,
358 const unsigned char *new_head, const char *msg)
359 {
360 struct strbuf reflog_message = STRBUF_INIT;
361 const unsigned char *head = head_commit->object.sha1;
362
363 if (!msg)
364 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
365 else {
366 if (verbosity >= 0)
367 printf("%s\n", msg);
368 strbuf_addf(&reflog_message, "%s: %s",
369 getenv("GIT_REFLOG_ACTION"), msg);
370 }
371 if (squash) {
372 squash_message(head_commit);
373 } else {
374 if (verbosity >= 0 && !merge_msg.len)
375 printf(_("No merge message -- not updating HEAD\n"));
376 else {
377 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
378 update_ref(reflog_message.buf, "HEAD",
379 new_head, head, 0,
380 DIE_ON_ERR);
381 /*
382 * We ignore errors in 'gc --auto', since the
383 * user should see them.
384 */
385 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
386 }
387 }
388 if (new_head && show_diffstat) {
389 struct diff_options opts;
390 diff_setup(&opts);
391 opts.output_format |=
392 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
393 opts.detect_rename = DIFF_DETECT_RENAME;
394 if (diff_setup_done(&opts) < 0)
395 die(_("diff_setup_done failed"));
396 diff_tree_sha1(head, new_head, "", &opts);
397 diffcore_std(&opts);
398 diff_flush(&opts);
399 }
400
401 /* Run a post-merge hook */
402 run_hook(NULL, "post-merge", squash ? "1" : "0", NULL);
403
404 strbuf_release(&reflog_message);
405 }
406
407 /* Get the name for the merge commit's message. */
408 static void merge_name(const char *remote, struct strbuf *msg)
409 {
410 struct object *remote_head;
411 unsigned char branch_head[20], buf_sha[20];
412 struct strbuf buf = STRBUF_INIT;
413 struct strbuf bname = STRBUF_INIT;
414 const char *ptr;
415 char *found_ref;
416 int len, early;
417
418 strbuf_branchname(&bname, remote);
419 remote = bname.buf;
420
421 memset(branch_head, 0, sizeof(branch_head));
422 remote_head = peel_to_type(remote, 0, NULL, OBJ_COMMIT);
423 if (!remote_head)
424 die(_("'%s' does not point to a commit"), remote);
425
426 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
427 if (!prefixcmp(found_ref, "refs/heads/")) {
428 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
429 sha1_to_hex(branch_head), remote);
430 goto cleanup;
431 }
432 if (!prefixcmp(found_ref, "refs/remotes/")) {
433 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
434 sha1_to_hex(branch_head), remote);
435 goto cleanup;
436 }
437 }
438
439 /* See if remote matches <name>^^^.. or <name>~<number> */
440 for (len = 0, ptr = remote + strlen(remote);
441 remote < ptr && ptr[-1] == '^';
442 ptr--)
443 len++;
444 if (len)
445 early = 1;
446 else {
447 early = 0;
448 ptr = strrchr(remote, '~');
449 if (ptr) {
450 int seen_nonzero = 0;
451
452 len++; /* count ~ */
453 while (*++ptr && isdigit(*ptr)) {
454 seen_nonzero |= (*ptr != '0');
455 len++;
456 }
457 if (*ptr)
458 len = 0; /* not ...~<number> */
459 else if (seen_nonzero)
460 early = 1;
461 else if (len == 1)
462 early = 1; /* "name~" is "name~1"! */
463 }
464 }
465 if (len) {
466 struct strbuf truname = STRBUF_INIT;
467 strbuf_addstr(&truname, "refs/heads/");
468 strbuf_addstr(&truname, remote);
469 strbuf_setlen(&truname, truname.len - len);
470 if (resolve_ref(truname.buf, buf_sha, 1, NULL)) {
471 strbuf_addf(msg,
472 "%s\t\tbranch '%s'%s of .\n",
473 sha1_to_hex(remote_head->sha1),
474 truname.buf + 11,
475 (early ? " (early part)" : ""));
476 strbuf_release(&truname);
477 goto cleanup;
478 }
479 }
480
481 if (!strcmp(remote, "FETCH_HEAD") &&
482 !access(git_path("FETCH_HEAD"), R_OK)) {
483 FILE *fp;
484 struct strbuf line = STRBUF_INIT;
485 char *ptr;
486
487 fp = fopen(git_path("FETCH_HEAD"), "r");
488 if (!fp)
489 die_errno(_("could not open '%s' for reading"),
490 git_path("FETCH_HEAD"));
491 strbuf_getline(&line, fp, '\n');
492 fclose(fp);
493 ptr = strstr(line.buf, "\tnot-for-merge\t");
494 if (ptr)
495 strbuf_remove(&line, ptr-line.buf+1, 13);
496 strbuf_addbuf(msg, &line);
497 strbuf_release(&line);
498 goto cleanup;
499 }
500 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
501 sha1_to_hex(remote_head->sha1), remote);
502 cleanup:
503 strbuf_release(&buf);
504 strbuf_release(&bname);
505 }
506
507 static void parse_branch_merge_options(char *bmo)
508 {
509 const char **argv;
510 int argc;
511
512 if (!bmo)
513 return;
514 argc = split_cmdline(bmo, &argv);
515 if (argc < 0)
516 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
517 split_cmdline_strerror(argc));
518 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
519 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
520 argc++;
521 argv[0] = "branch.*.mergeoptions";
522 parse_options(argc, argv, NULL, builtin_merge_options,
523 builtin_merge_usage, 0);
524 free(argv);
525 }
526
527 static int git_merge_config(const char *k, const char *v, void *cb)
528 {
529 if (branch && !prefixcmp(k, "branch.") &&
530 !prefixcmp(k + 7, branch) &&
531 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
532 free(branch_mergeoptions);
533 branch_mergeoptions = xstrdup(v);
534 return 0;
535 }
536
537 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
538 show_diffstat = git_config_bool(k, v);
539 else if (!strcmp(k, "pull.twohead"))
540 return git_config_string(&pull_twohead, k, v);
541 else if (!strcmp(k, "pull.octopus"))
542 return git_config_string(&pull_octopus, k, v);
543 else if (!strcmp(k, "merge.renormalize"))
544 option_renormalize = git_config_bool(k, v);
545 else if (!strcmp(k, "merge.log") || !strcmp(k, "merge.summary")) {
546 int is_bool;
547 shortlog_len = git_config_bool_or_int(k, v, &is_bool);
548 if (!is_bool && shortlog_len < 0)
549 return error(_("%s: negative length %s"), k, v);
550 if (is_bool && shortlog_len)
551 shortlog_len = DEFAULT_MERGE_LOG_LEN;
552 return 0;
553 } else if (!strcmp(k, "merge.ff")) {
554 int boolval = git_config_maybe_bool(k, v);
555 if (0 <= boolval) {
556 allow_fast_forward = boolval;
557 } else if (v && !strcmp(v, "only")) {
558 allow_fast_forward = 1;
559 fast_forward_only = 1;
560 } /* do not barf on values from future versions of git */
561 return 0;
562 } else if (!strcmp(k, "merge.defaulttoupstream")) {
563 default_to_upstream = git_config_bool(k, v);
564 return 0;
565 }
566 return git_diff_ui_config(k, v, cb);
567 }
568
569 static int read_tree_trivial(unsigned char *common, unsigned char *head,
570 unsigned char *one)
571 {
572 int i, nr_trees = 0;
573 struct tree *trees[MAX_UNPACK_TREES];
574 struct tree_desc t[MAX_UNPACK_TREES];
575 struct unpack_trees_options opts;
576
577 memset(&opts, 0, sizeof(opts));
578 opts.head_idx = 2;
579 opts.src_index = &the_index;
580 opts.dst_index = &the_index;
581 opts.update = 1;
582 opts.verbose_update = 1;
583 opts.trivial_merges_only = 1;
584 opts.merge = 1;
585 trees[nr_trees] = parse_tree_indirect(common);
586 if (!trees[nr_trees++])
587 return -1;
588 trees[nr_trees] = parse_tree_indirect(head);
589 if (!trees[nr_trees++])
590 return -1;
591 trees[nr_trees] = parse_tree_indirect(one);
592 if (!trees[nr_trees++])
593 return -1;
594 opts.fn = threeway_merge;
595 cache_tree_free(&active_cache_tree);
596 for (i = 0; i < nr_trees; i++) {
597 parse_tree(trees[i]);
598 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
599 }
600 if (unpack_trees(nr_trees, t, &opts))
601 return -1;
602 return 0;
603 }
604
605 static void write_tree_trivial(unsigned char *sha1)
606 {
607 if (write_cache_as_tree(sha1, 0, NULL))
608 die(_("git write-tree failed to write a tree"));
609 }
610
611 static const char *merge_argument(struct commit *commit)
612 {
613 if (commit)
614 return sha1_to_hex(commit->object.sha1);
615 else
616 return EMPTY_TREE_SHA1_HEX;
617 }
618
619 int try_merge_command(const char *strategy, size_t xopts_nr,
620 const char **xopts, struct commit_list *common,
621 const char *head_arg, struct commit_list *remotes)
622 {
623 const char **args;
624 int i = 0, x = 0, ret;
625 struct commit_list *j;
626 struct strbuf buf = STRBUF_INIT;
627
628 args = xmalloc((4 + xopts_nr + commit_list_count(common) +
629 commit_list_count(remotes)) * sizeof(char *));
630 strbuf_addf(&buf, "merge-%s", strategy);
631 args[i++] = buf.buf;
632 for (x = 0; x < xopts_nr; x++) {
633 char *s = xmalloc(strlen(xopts[x])+2+1);
634 strcpy(s, "--");
635 strcpy(s+2, xopts[x]);
636 args[i++] = s;
637 }
638 for (j = common; j; j = j->next)
639 args[i++] = xstrdup(merge_argument(j->item));
640 args[i++] = "--";
641 args[i++] = head_arg;
642 for (j = remotes; j; j = j->next)
643 args[i++] = xstrdup(merge_argument(j->item));
644 args[i] = NULL;
645 ret = run_command_v_opt(args, RUN_GIT_CMD);
646 strbuf_release(&buf);
647 i = 1;
648 for (x = 0; x < xopts_nr; x++)
649 free((void *)args[i++]);
650 for (j = common; j; j = j->next)
651 free((void *)args[i++]);
652 i += 2;
653 for (j = remotes; j; j = j->next)
654 free((void *)args[i++]);
655 free(args);
656 discard_cache();
657 if (read_cache() < 0)
658 die(_("failed to read the cache"));
659 resolve_undo_clear();
660
661 return ret;
662 }
663
664 static int try_merge_strategy(const char *strategy, struct commit_list *common,
665 struct commit *head, const char *head_arg)
666 {
667 int index_fd;
668 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
669
670 index_fd = hold_locked_index(lock, 1);
671 refresh_cache(REFRESH_QUIET);
672 if (active_cache_changed &&
673 (write_cache(index_fd, active_cache, active_nr) ||
674 commit_locked_index(lock)))
675 return error(_("Unable to write index."));
676 rollback_lock_file(lock);
677
678 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
679 int clean, x;
680 struct commit *result;
681 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
682 int index_fd;
683 struct commit_list *reversed = NULL;
684 struct merge_options o;
685 struct commit_list *j;
686
687 if (remoteheads->next) {
688 error(_("Not handling anything other than two heads merge."));
689 return 2;
690 }
691
692 init_merge_options(&o);
693 if (!strcmp(strategy, "subtree"))
694 o.subtree_shift = "";
695
696 o.renormalize = option_renormalize;
697 o.show_rename_progress =
698 show_progress == -1 ? isatty(2) : show_progress;
699
700 for (x = 0; x < xopts_nr; x++)
701 if (parse_merge_opt(&o, xopts[x]))
702 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
703
704 o.branch1 = head_arg;
705 o.branch2 = remoteheads->item->util;
706
707 for (j = common; j; j = j->next)
708 commit_list_insert(j->item, &reversed);
709
710 index_fd = hold_locked_index(lock, 1);
711 clean = merge_recursive(&o, head,
712 remoteheads->item, reversed, &result);
713 if (active_cache_changed &&
714 (write_cache(index_fd, active_cache, active_nr) ||
715 commit_locked_index(lock)))
716 die (_("unable to write %s"), get_index_file());
717 rollback_lock_file(lock);
718 return clean ? 0 : 1;
719 } else {
720 return try_merge_command(strategy, xopts_nr, xopts,
721 common, head_arg, remoteheads);
722 }
723 }
724
725 static void count_diff_files(struct diff_queue_struct *q,
726 struct diff_options *opt, void *data)
727 {
728 int *count = data;
729
730 (*count) += q->nr;
731 }
732
733 static int count_unmerged_entries(void)
734 {
735 int i, ret = 0;
736
737 for (i = 0; i < active_nr; i++)
738 if (ce_stage(active_cache[i]))
739 ret++;
740
741 return ret;
742 }
743
744 int checkout_fast_forward(const unsigned char *head, const unsigned char *remote)
745 {
746 struct tree *trees[MAX_UNPACK_TREES];
747 struct unpack_trees_options opts;
748 struct tree_desc t[MAX_UNPACK_TREES];
749 int i, fd, nr_trees = 0;
750 struct dir_struct dir;
751 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
752
753 refresh_cache(REFRESH_QUIET);
754
755 fd = hold_locked_index(lock_file, 1);
756
757 memset(&trees, 0, sizeof(trees));
758 memset(&opts, 0, sizeof(opts));
759 memset(&t, 0, sizeof(t));
760 memset(&dir, 0, sizeof(dir));
761 dir.flags |= DIR_SHOW_IGNORED;
762 dir.exclude_per_dir = ".gitignore";
763 opts.dir = &dir;
764
765 opts.head_idx = 1;
766 opts.src_index = &the_index;
767 opts.dst_index = &the_index;
768 opts.update = 1;
769 opts.verbose_update = 1;
770 opts.merge = 1;
771 opts.fn = twoway_merge;
772 setup_unpack_trees_porcelain(&opts, "merge");
773
774 trees[nr_trees] = parse_tree_indirect(head);
775 if (!trees[nr_trees++])
776 return -1;
777 trees[nr_trees] = parse_tree_indirect(remote);
778 if (!trees[nr_trees++])
779 return -1;
780 for (i = 0; i < nr_trees; i++) {
781 parse_tree(trees[i]);
782 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
783 }
784 if (unpack_trees(nr_trees, t, &opts))
785 return -1;
786 if (write_cache(fd, active_cache, active_nr) ||
787 commit_locked_index(lock_file))
788 die(_("unable to write new index file"));
789 return 0;
790 }
791
792 static void split_merge_strategies(const char *string, struct strategy **list,
793 int *nr, int *alloc)
794 {
795 char *p, *q, *buf;
796
797 if (!string)
798 return;
799
800 buf = xstrdup(string);
801 q = buf;
802 for (;;) {
803 p = strchr(q, ' ');
804 if (!p) {
805 ALLOC_GROW(*list, *nr + 1, *alloc);
806 (*list)[(*nr)++].name = xstrdup(q);
807 free(buf);
808 return;
809 } else {
810 *p = '\0';
811 ALLOC_GROW(*list, *nr + 1, *alloc);
812 (*list)[(*nr)++].name = xstrdup(q);
813 q = ++p;
814 }
815 }
816 }
817
818 static void add_strategies(const char *string, unsigned attr)
819 {
820 struct strategy *list = NULL;
821 int list_alloc = 0, list_nr = 0, i;
822
823 memset(&list, 0, sizeof(list));
824 split_merge_strategies(string, &list, &list_nr, &list_alloc);
825 if (list) {
826 for (i = 0; i < list_nr; i++)
827 append_strategy(get_strategy(list[i].name));
828 return;
829 }
830 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
831 if (all_strategy[i].attr & attr)
832 append_strategy(&all_strategy[i]);
833
834 }
835
836 static void write_merge_msg(void)
837 {
838 int fd = open(git_path("MERGE_MSG"), O_WRONLY | O_CREAT, 0666);
839 if (fd < 0)
840 die_errno(_("Could not open '%s' for writing"),
841 git_path("MERGE_MSG"));
842 if (write_in_full(fd, merge_msg.buf, merge_msg.len) != merge_msg.len)
843 die_errno(_("Could not write to '%s'"), git_path("MERGE_MSG"));
844 close(fd);
845 }
846
847 static void read_merge_msg(void)
848 {
849 strbuf_reset(&merge_msg);
850 if (strbuf_read_file(&merge_msg, git_path("MERGE_MSG"), 0) < 0)
851 die_errno(_("Could not read from '%s'"), git_path("MERGE_MSG"));
852 }
853
854 static void run_prepare_commit_msg(void)
855 {
856 write_merge_msg();
857 run_hook(get_index_file(), "prepare-commit-msg",
858 git_path("MERGE_MSG"), "merge", NULL, NULL);
859 read_merge_msg();
860 }
861
862 static int merge_trivial(struct commit *head)
863 {
864 unsigned char result_tree[20], result_commit[20];
865 struct commit_list *parent = xmalloc(sizeof(*parent));
866
867 write_tree_trivial(result_tree);
868 printf(_("Wonderful.\n"));
869 parent->item = head;
870 parent->next = xmalloc(sizeof(*parent->next));
871 parent->next->item = remoteheads->item;
872 parent->next->next = NULL;
873 run_prepare_commit_msg();
874 commit_tree(merge_msg.buf, result_tree, parent, result_commit, NULL);
875 finish(head, result_commit, "In-index merge");
876 drop_save();
877 return 0;
878 }
879
880 static int finish_automerge(struct commit *head,
881 struct commit_list *common,
882 unsigned char *result_tree,
883 const char *wt_strategy)
884 {
885 struct commit_list *parents = NULL, *j;
886 struct strbuf buf = STRBUF_INIT;
887 unsigned char result_commit[20];
888
889 free_commit_list(common);
890 if (allow_fast_forward) {
891 parents = remoteheads;
892 commit_list_insert(head, &parents);
893 parents = reduce_heads(parents);
894 } else {
895 struct commit_list **pptr = &parents;
896
897 pptr = &commit_list_insert(head,
898 pptr)->next;
899 for (j = remoteheads; j; j = j->next)
900 pptr = &commit_list_insert(j->item, pptr)->next;
901 }
902 free_commit_list(remoteheads);
903 strbuf_addch(&merge_msg, '\n');
904 run_prepare_commit_msg();
905 commit_tree(merge_msg.buf, result_tree, parents, result_commit, NULL);
906 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
907 finish(head, result_commit, buf.buf);
908 strbuf_release(&buf);
909 drop_save();
910 return 0;
911 }
912
913 static int suggest_conflicts(int renormalizing)
914 {
915 FILE *fp;
916 int pos;
917
918 fp = fopen(git_path("MERGE_MSG"), "a");
919 if (!fp)
920 die_errno(_("Could not open '%s' for writing"),
921 git_path("MERGE_MSG"));
922 fprintf(fp, "\nConflicts:\n");
923 for (pos = 0; pos < active_nr; pos++) {
924 struct cache_entry *ce = active_cache[pos];
925
926 if (ce_stage(ce)) {
927 fprintf(fp, "\t%s\n", ce->name);
928 while (pos + 1 < active_nr &&
929 !strcmp(ce->name,
930 active_cache[pos + 1]->name))
931 pos++;
932 }
933 }
934 fclose(fp);
935 rerere(allow_rerere_auto);
936 printf(_("Automatic merge failed; "
937 "fix conflicts and then commit the result.\n"));
938 return 1;
939 }
940
941 static struct commit *is_old_style_invocation(int argc, const char **argv,
942 const unsigned char *head)
943 {
944 struct commit *second_token = NULL;
945 if (argc > 2) {
946 unsigned char second_sha1[20];
947
948 if (get_sha1(argv[1], second_sha1))
949 return NULL;
950 second_token = lookup_commit_reference_gently(second_sha1, 0);
951 if (!second_token)
952 die(_("'%s' is not a commit"), argv[1]);
953 if (hashcmp(second_token->object.sha1, head))
954 return NULL;
955 }
956 return second_token;
957 }
958
959 static int evaluate_result(void)
960 {
961 int cnt = 0;
962 struct rev_info rev;
963
964 /* Check how many files differ. */
965 init_revisions(&rev, "");
966 setup_revisions(0, NULL, &rev, NULL);
967 rev.diffopt.output_format |=
968 DIFF_FORMAT_CALLBACK;
969 rev.diffopt.format_callback = count_diff_files;
970 rev.diffopt.format_callback_data = &cnt;
971 run_diff_files(&rev, 0);
972
973 /*
974 * Check how many unmerged entries are
975 * there.
976 */
977 cnt += count_unmerged_entries();
978
979 return cnt;
980 }
981
982 /*
983 * Pretend as if the user told us to merge with the tracking
984 * branch we have for the upstream of the current branch
985 */
986 static int setup_with_upstream(const char ***argv)
987 {
988 struct branch *branch = branch_get(NULL);
989 int i;
990 const char **args;
991
992 if (!branch)
993 die(_("No current branch."));
994 if (!branch->remote)
995 die(_("No remote for the current branch."));
996 if (!branch->merge_nr)
997 die(_("No default upstream defined for the current branch."));
998
999 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
1000 for (i = 0; i < branch->merge_nr; i++) {
1001 if (!branch->merge[i]->dst)
1002 die(_("No remote tracking branch for %s from %s"),
1003 branch->merge[i]->src, branch->remote_name);
1004 args[i] = branch->merge[i]->dst;
1005 }
1006 args[i] = NULL;
1007 *argv = args;
1008 return i;
1009 }
1010
1011 int cmd_merge(int argc, const char **argv, const char *prefix)
1012 {
1013 unsigned char result_tree[20];
1014 unsigned char stash[20];
1015 unsigned char head_sha1[20];
1016 struct commit *head_commit;
1017 struct strbuf buf = STRBUF_INIT;
1018 const char *head_arg;
1019 int flag, i;
1020 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1021 struct commit_list *common = NULL;
1022 const char *best_strategy = NULL, *wt_strategy = NULL;
1023 struct commit_list **remotes = &remoteheads;
1024
1025 if (argc == 2 && !strcmp(argv[1], "-h"))
1026 usage_with_options(builtin_merge_usage, builtin_merge_options);
1027
1028 /*
1029 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1030 * current branch.
1031 */
1032 branch = resolve_ref("HEAD", head_sha1, 0, &flag);
1033 if (branch && !prefixcmp(branch, "refs/heads/"))
1034 branch += 11;
1035 if (!branch || is_null_sha1(head_sha1))
1036 head_commit = NULL;
1037 else
1038 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1039
1040 git_config(git_merge_config, NULL);
1041
1042 if (branch_mergeoptions)
1043 parse_branch_merge_options(branch_mergeoptions);
1044 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1045 builtin_merge_usage, 0);
1046
1047 if (verbosity < 0 && show_progress == -1)
1048 show_progress = 0;
1049
1050 if (abort_current_merge) {
1051 int nargc = 2;
1052 const char *nargv[] = {"reset", "--merge", NULL};
1053
1054 if (!file_exists(git_path("MERGE_HEAD")))
1055 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1056
1057 /* Invoke 'git reset --merge' */
1058 return cmd_reset(nargc, nargv, prefix);
1059 }
1060
1061 if (read_cache_unmerged())
1062 die_resolve_conflict("merge");
1063
1064 if (file_exists(git_path("MERGE_HEAD"))) {
1065 /*
1066 * There is no unmerged entry, don't advise 'git
1067 * add/rm <file>', just 'git commit'.
1068 */
1069 if (advice_resolve_conflict)
1070 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1071 "Please, commit your changes before you can merge."));
1072 else
1073 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1074 }
1075 if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
1076 if (advice_resolve_conflict)
1077 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1078 "Please, commit your changes before you can merge."));
1079 else
1080 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1081 }
1082 resolve_undo_clear();
1083
1084 if (verbosity < 0)
1085 show_diffstat = 0;
1086
1087 if (squash) {
1088 if (!allow_fast_forward)
1089 die(_("You cannot combine --squash with --no-ff."));
1090 option_commit = 0;
1091 }
1092
1093 if (!allow_fast_forward && fast_forward_only)
1094 die(_("You cannot combine --no-ff with --ff-only."));
1095
1096 if (!abort_current_merge) {
1097 if (!argc && default_to_upstream)
1098 argc = setup_with_upstream(&argv);
1099 else if (argc == 1 && !strcmp(argv[0], "-"))
1100 argv[0] = "@{-1}";
1101 }
1102 if (!argc)
1103 usage_with_options(builtin_merge_usage,
1104 builtin_merge_options);
1105
1106 /*
1107 * This could be traditional "merge <msg> HEAD <commit>..." and
1108 * the way we can tell it is to see if the second token is HEAD,
1109 * but some people might have misused the interface and used a
1110 * committish that is the same as HEAD there instead.
1111 * Traditional format never would have "-m" so it is an
1112 * additional safety measure to check for it.
1113 */
1114
1115 if (!have_message && head_commit &&
1116 is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
1117 strbuf_addstr(&merge_msg, argv[0]);
1118 head_arg = argv[1];
1119 argv += 2;
1120 argc -= 2;
1121 } else if (!head_commit) {
1122 struct object *remote_head;
1123 /*
1124 * If the merged head is a valid one there is no reason
1125 * to forbid "git merge" into a branch yet to be born.
1126 * We do the same for "git pull".
1127 */
1128 if (argc != 1)
1129 die(_("Can merge only exactly one commit into "
1130 "empty head"));
1131 if (squash)
1132 die(_("Squash commit into empty head not supported yet"));
1133 if (!allow_fast_forward)
1134 die(_("Non-fast-forward commit does not make sense into "
1135 "an empty head"));
1136 remote_head = peel_to_type(argv[0], 0, NULL, OBJ_COMMIT);
1137 if (!remote_head)
1138 die(_("%s - not something we can merge"), argv[0]);
1139 read_empty(remote_head->sha1, 0);
1140 update_ref("initial pull", "HEAD", remote_head->sha1, NULL, 0,
1141 DIE_ON_ERR);
1142 return 0;
1143 } else {
1144 struct strbuf merge_names = STRBUF_INIT;
1145
1146 /* We are invoked directly as the first-class UI. */
1147 head_arg = "HEAD";
1148
1149 /*
1150 * All the rest are the commits being merged;
1151 * prepare the standard merge summary message to
1152 * be appended to the given message. If remote
1153 * is invalid we will die later in the common
1154 * codepath so we discard the error in this
1155 * loop.
1156 */
1157 for (i = 0; i < argc; i++)
1158 merge_name(argv[i], &merge_names);
1159
1160 if (!have_message || shortlog_len) {
1161 fmt_merge_msg(&merge_names, &merge_msg, !have_message,
1162 shortlog_len);
1163 if (merge_msg.len)
1164 strbuf_setlen(&merge_msg, merge_msg.len - 1);
1165 }
1166 }
1167
1168 if (!head_commit || !argc)
1169 usage_with_options(builtin_merge_usage,
1170 builtin_merge_options);
1171
1172 strbuf_addstr(&buf, "merge");
1173 for (i = 0; i < argc; i++)
1174 strbuf_addf(&buf, " %s", argv[i]);
1175 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1176 strbuf_reset(&buf);
1177
1178 for (i = 0; i < argc; i++) {
1179 struct object *o;
1180 struct commit *commit;
1181
1182 o = peel_to_type(argv[i], 0, NULL, OBJ_COMMIT);
1183 if (!o)
1184 die(_("%s - not something we can merge"), argv[i]);
1185 commit = lookup_commit(o->sha1);
1186 commit->util = (void *)argv[i];
1187 remotes = &commit_list_insert(commit, remotes)->next;
1188
1189 strbuf_addf(&buf, "GITHEAD_%s", sha1_to_hex(o->sha1));
1190 setenv(buf.buf, argv[i], 1);
1191 strbuf_reset(&buf);
1192 }
1193
1194 if (!use_strategies) {
1195 if (!remoteheads->next)
1196 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1197 else
1198 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1199 }
1200
1201 for (i = 0; i < use_strategies_nr; i++) {
1202 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1203 allow_fast_forward = 0;
1204 if (use_strategies[i]->attr & NO_TRIVIAL)
1205 allow_trivial = 0;
1206 }
1207
1208 if (!remoteheads->next)
1209 common = get_merge_bases(head_commit, remoteheads->item, 1);
1210 else {
1211 struct commit_list *list = remoteheads;
1212 commit_list_insert(head_commit, &list);
1213 common = get_octopus_merge_bases(list);
1214 free(list);
1215 }
1216
1217 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
1218 NULL, 0, DIE_ON_ERR);
1219
1220 if (!common)
1221 ; /* No common ancestors found. We need a real merge. */
1222 else if (!remoteheads->next && !common->next &&
1223 common->item == remoteheads->item) {
1224 /*
1225 * If head can reach all the merge then we are up to date.
1226 * but first the most common case of merging one remote.
1227 */
1228 finish_up_to_date("Already up-to-date.");
1229 return 0;
1230 } else if (allow_fast_forward && !remoteheads->next &&
1231 !common->next &&
1232 !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
1233 /* Again the most common case of merging one remote. */
1234 struct strbuf msg = STRBUF_INIT;
1235 struct object *o;
1236 char hex[41];
1237
1238 strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
1239
1240 if (verbosity >= 0)
1241 printf(_("Updating %s..%s\n"),
1242 hex,
1243 find_unique_abbrev(remoteheads->item->object.sha1,
1244 DEFAULT_ABBREV));
1245 strbuf_addstr(&msg, "Fast-forward");
1246 if (have_message)
1247 strbuf_addstr(&msg,
1248 " (no commit created; -m option ignored)");
1249 o = peel_to_type(sha1_to_hex(remoteheads->item->object.sha1),
1250 0, NULL, OBJ_COMMIT);
1251 if (!o)
1252 return 1;
1253
1254 if (checkout_fast_forward(head_commit->object.sha1, remoteheads->item->object.sha1))
1255 return 1;
1256
1257 finish(head_commit, o->sha1, msg.buf);
1258 drop_save();
1259 return 0;
1260 } else if (!remoteheads->next && common->next)
1261 ;
1262 /*
1263 * We are not doing octopus and not fast-forward. Need
1264 * a real merge.
1265 */
1266 else if (!remoteheads->next && !common->next && option_commit) {
1267 /*
1268 * We are not doing octopus, not fast-forward, and have
1269 * only one common.
1270 */
1271 refresh_cache(REFRESH_QUIET);
1272 if (allow_trivial && !fast_forward_only) {
1273 /* See if it is really trivial. */
1274 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1275 printf(_("Trying really trivial in-index merge...\n"));
1276 if (!read_tree_trivial(common->item->object.sha1,
1277 head_commit->object.sha1, remoteheads->item->object.sha1))
1278 return merge_trivial(head_commit);
1279 printf(_("Nope.\n"));
1280 }
1281 } else {
1282 /*
1283 * An octopus. If we can reach all the remote we are up
1284 * to date.
1285 */
1286 int up_to_date = 1;
1287 struct commit_list *j;
1288
1289 for (j = remoteheads; j; j = j->next) {
1290 struct commit_list *common_one;
1291
1292 /*
1293 * Here we *have* to calculate the individual
1294 * merge_bases again, otherwise "git merge HEAD^
1295 * HEAD^^" would be missed.
1296 */
1297 common_one = get_merge_bases(head_commit, j->item, 1);
1298 if (hashcmp(common_one->item->object.sha1,
1299 j->item->object.sha1)) {
1300 up_to_date = 0;
1301 break;
1302 }
1303 }
1304 if (up_to_date) {
1305 finish_up_to_date("Already up-to-date. Yeeah!");
1306 return 0;
1307 }
1308 }
1309
1310 if (fast_forward_only)
1311 die(_("Not possible to fast-forward, aborting."));
1312
1313 /* We are going to make a new commit. */
1314 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1315
1316 /*
1317 * At this point, we need a real merge. No matter what strategy
1318 * we use, it would operate on the index, possibly affecting the
1319 * working tree, and when resolved cleanly, have the desired
1320 * tree in the index -- this means that the index must be in
1321 * sync with the head commit. The strategies are responsible
1322 * to ensure this.
1323 */
1324 if (use_strategies_nr == 1 ||
1325 /*
1326 * Stash away the local changes so that we can try more than one.
1327 */
1328 save_state(stash))
1329 hashcpy(stash, null_sha1);
1330
1331 for (i = 0; i < use_strategies_nr; i++) {
1332 int ret;
1333 if (i) {
1334 printf(_("Rewinding the tree to pristine...\n"));
1335 restore_state(head_commit->object.sha1, stash);
1336 }
1337 if (use_strategies_nr != 1)
1338 printf(_("Trying merge strategy %s...\n"),
1339 use_strategies[i]->name);
1340 /*
1341 * Remember which strategy left the state in the working
1342 * tree.
1343 */
1344 wt_strategy = use_strategies[i]->name;
1345
1346 ret = try_merge_strategy(use_strategies[i]->name,
1347 common, head_commit, head_arg);
1348 if (!option_commit && !ret) {
1349 merge_was_ok = 1;
1350 /*
1351 * This is necessary here just to avoid writing
1352 * the tree, but later we will *not* exit with
1353 * status code 1 because merge_was_ok is set.
1354 */
1355 ret = 1;
1356 }
1357
1358 if (ret) {
1359 /*
1360 * The backend exits with 1 when conflicts are
1361 * left to be resolved, with 2 when it does not
1362 * handle the given merge at all.
1363 */
1364 if (ret == 1) {
1365 int cnt = evaluate_result();
1366
1367 if (best_cnt <= 0 || cnt <= best_cnt) {
1368 best_strategy = use_strategies[i]->name;
1369 best_cnt = cnt;
1370 }
1371 }
1372 if (merge_was_ok)
1373 break;
1374 else
1375 continue;
1376 }
1377
1378 /* Automerge succeeded. */
1379 write_tree_trivial(result_tree);
1380 automerge_was_ok = 1;
1381 break;
1382 }
1383
1384 /*
1385 * If we have a resulting tree, that means the strategy module
1386 * auto resolved the merge cleanly.
1387 */
1388 if (automerge_was_ok)
1389 return finish_automerge(head_commit, common, result_tree,
1390 wt_strategy);
1391
1392 /*
1393 * Pick the result from the best strategy and have the user fix
1394 * it up.
1395 */
1396 if (!best_strategy) {
1397 restore_state(head_commit->object.sha1, stash);
1398 if (use_strategies_nr > 1)
1399 fprintf(stderr,
1400 _("No merge strategy handled the merge.\n"));
1401 else
1402 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1403 use_strategies[0]->name);
1404 return 2;
1405 } else if (best_strategy == wt_strategy)
1406 ; /* We already have its result in the working tree. */
1407 else {
1408 printf(_("Rewinding the tree to pristine...\n"));
1409 restore_state(head_commit->object.sha1, stash);
1410 printf(_("Using the %s to prepare resolving by hand.\n"),
1411 best_strategy);
1412 try_merge_strategy(best_strategy, common, head_commit, head_arg);
1413 }
1414
1415 if (squash)
1416 finish(head_commit, NULL, NULL);
1417 else {
1418 int fd;
1419 struct commit_list *j;
1420
1421 for (j = remoteheads; j; j = j->next)
1422 strbuf_addf(&buf, "%s\n",
1423 sha1_to_hex(j->item->object.sha1));
1424 fd = open(git_path("MERGE_HEAD"), O_WRONLY | O_CREAT, 0666);
1425 if (fd < 0)
1426 die_errno(_("Could not open '%s' for writing"),
1427 git_path("MERGE_HEAD"));
1428 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1429 die_errno(_("Could not write to '%s'"), git_path("MERGE_HEAD"));
1430 close(fd);
1431 strbuf_addch(&merge_msg, '\n');
1432 write_merge_msg();
1433 fd = open(git_path("MERGE_MODE"), O_WRONLY | O_CREAT | O_TRUNC, 0666);
1434 if (fd < 0)
1435 die_errno(_("Could not open '%s' for writing"),
1436 git_path("MERGE_MODE"));
1437 strbuf_reset(&buf);
1438 if (!allow_fast_forward)
1439 strbuf_addf(&buf, "no-ff");
1440 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1441 die_errno(_("Could not write to '%s'"), git_path("MERGE_MODE"));
1442 close(fd);
1443 }
1444
1445 if (merge_was_ok) {
1446 fprintf(stderr, _("Automatic merge went well; "
1447 "stopped before committing as requested\n"));
1448 return 0;
1449 } else
1450 return suggest_conflicts(option_renormalize);
1451 }