Accept tags in HEAD or MERGE_HEAD
[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_use_color_default > 0)
395 DIFF_OPT_SET(&opts, COLOR_DIFF);
396 if (diff_setup_done(&opts) < 0)
397 die(_("diff_setup_done failed"));
398 diff_tree_sha1(head, new_head, "", &opts);
399 diffcore_std(&opts);
400 diff_flush(&opts);
401 }
402
403 /* Run a post-merge hook */
404 run_hook(NULL, "post-merge", squash ? "1" : "0", NULL);
405
406 strbuf_release(&reflog_message);
407 }
408
409 /* Get the name for the merge commit's message. */
410 static void merge_name(const char *remote, struct strbuf *msg)
411 {
412 struct object *remote_head;
413 unsigned char branch_head[20], buf_sha[20];
414 struct strbuf buf = STRBUF_INIT;
415 struct strbuf bname = STRBUF_INIT;
416 const char *ptr;
417 char *found_ref;
418 int len, early;
419
420 strbuf_branchname(&bname, remote);
421 remote = bname.buf;
422
423 memset(branch_head, 0, sizeof(branch_head));
424 remote_head = peel_to_type(remote, 0, NULL, OBJ_COMMIT);
425 if (!remote_head)
426 die(_("'%s' does not point to a commit"), remote);
427
428 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
429 if (!prefixcmp(found_ref, "refs/heads/")) {
430 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
431 sha1_to_hex(branch_head), remote);
432 goto cleanup;
433 }
434 if (!prefixcmp(found_ref, "refs/remotes/")) {
435 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
436 sha1_to_hex(branch_head), remote);
437 goto cleanup;
438 }
439 }
440
441 /* See if remote matches <name>^^^.. or <name>~<number> */
442 for (len = 0, ptr = remote + strlen(remote);
443 remote < ptr && ptr[-1] == '^';
444 ptr--)
445 len++;
446 if (len)
447 early = 1;
448 else {
449 early = 0;
450 ptr = strrchr(remote, '~');
451 if (ptr) {
452 int seen_nonzero = 0;
453
454 len++; /* count ~ */
455 while (*++ptr && isdigit(*ptr)) {
456 seen_nonzero |= (*ptr != '0');
457 len++;
458 }
459 if (*ptr)
460 len = 0; /* not ...~<number> */
461 else if (seen_nonzero)
462 early = 1;
463 else if (len == 1)
464 early = 1; /* "name~" is "name~1"! */
465 }
466 }
467 if (len) {
468 struct strbuf truname = STRBUF_INIT;
469 strbuf_addstr(&truname, "refs/heads/");
470 strbuf_addstr(&truname, remote);
471 strbuf_setlen(&truname, truname.len - len);
472 if (resolve_ref(truname.buf, buf_sha, 1, NULL)) {
473 strbuf_addf(msg,
474 "%s\t\tbranch '%s'%s of .\n",
475 sha1_to_hex(remote_head->sha1),
476 truname.buf + 11,
477 (early ? " (early part)" : ""));
478 strbuf_release(&truname);
479 goto cleanup;
480 }
481 }
482
483 if (!strcmp(remote, "FETCH_HEAD") &&
484 !access(git_path("FETCH_HEAD"), R_OK)) {
485 FILE *fp;
486 struct strbuf line = STRBUF_INIT;
487 char *ptr;
488
489 fp = fopen(git_path("FETCH_HEAD"), "r");
490 if (!fp)
491 die_errno(_("could not open '%s' for reading"),
492 git_path("FETCH_HEAD"));
493 strbuf_getline(&line, fp, '\n');
494 fclose(fp);
495 ptr = strstr(line.buf, "\tnot-for-merge\t");
496 if (ptr)
497 strbuf_remove(&line, ptr-line.buf+1, 13);
498 strbuf_addbuf(msg, &line);
499 strbuf_release(&line);
500 goto cleanup;
501 }
502 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
503 sha1_to_hex(remote_head->sha1), remote);
504 cleanup:
505 strbuf_release(&buf);
506 strbuf_release(&bname);
507 }
508
509 static void parse_branch_merge_options(char *bmo)
510 {
511 const char **argv;
512 int argc;
513
514 if (!bmo)
515 return;
516 argc = split_cmdline(bmo, &argv);
517 if (argc < 0)
518 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
519 split_cmdline_strerror(argc));
520 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
521 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
522 argc++;
523 argv[0] = "branch.*.mergeoptions";
524 parse_options(argc, argv, NULL, builtin_merge_options,
525 builtin_merge_usage, 0);
526 free(argv);
527 }
528
529 static int git_merge_config(const char *k, const char *v, void *cb)
530 {
531 if (branch && !prefixcmp(k, "branch.") &&
532 !prefixcmp(k + 7, branch) &&
533 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
534 free(branch_mergeoptions);
535 branch_mergeoptions = xstrdup(v);
536 return 0;
537 }
538
539 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
540 show_diffstat = git_config_bool(k, v);
541 else if (!strcmp(k, "pull.twohead"))
542 return git_config_string(&pull_twohead, k, v);
543 else if (!strcmp(k, "pull.octopus"))
544 return git_config_string(&pull_octopus, k, v);
545 else if (!strcmp(k, "merge.renormalize"))
546 option_renormalize = git_config_bool(k, v);
547 else if (!strcmp(k, "merge.log") || !strcmp(k, "merge.summary")) {
548 int is_bool;
549 shortlog_len = git_config_bool_or_int(k, v, &is_bool);
550 if (!is_bool && shortlog_len < 0)
551 return error(_("%s: negative length %s"), k, v);
552 if (is_bool && shortlog_len)
553 shortlog_len = DEFAULT_MERGE_LOG_LEN;
554 return 0;
555 } else if (!strcmp(k, "merge.ff")) {
556 int boolval = git_config_maybe_bool(k, v);
557 if (0 <= boolval) {
558 allow_fast_forward = boolval;
559 } else if (v && !strcmp(v, "only")) {
560 allow_fast_forward = 1;
561 fast_forward_only = 1;
562 } /* do not barf on values from future versions of git */
563 return 0;
564 } else if (!strcmp(k, "merge.defaulttoupstream")) {
565 default_to_upstream = git_config_bool(k, v);
566 return 0;
567 }
568 return git_diff_ui_config(k, v, cb);
569 }
570
571 static int read_tree_trivial(unsigned char *common, unsigned char *head,
572 unsigned char *one)
573 {
574 int i, nr_trees = 0;
575 struct tree *trees[MAX_UNPACK_TREES];
576 struct tree_desc t[MAX_UNPACK_TREES];
577 struct unpack_trees_options opts;
578
579 memset(&opts, 0, sizeof(opts));
580 opts.head_idx = 2;
581 opts.src_index = &the_index;
582 opts.dst_index = &the_index;
583 opts.update = 1;
584 opts.verbose_update = 1;
585 opts.trivial_merges_only = 1;
586 opts.merge = 1;
587 trees[nr_trees] = parse_tree_indirect(common);
588 if (!trees[nr_trees++])
589 return -1;
590 trees[nr_trees] = parse_tree_indirect(head);
591 if (!trees[nr_trees++])
592 return -1;
593 trees[nr_trees] = parse_tree_indirect(one);
594 if (!trees[nr_trees++])
595 return -1;
596 opts.fn = threeway_merge;
597 cache_tree_free(&active_cache_tree);
598 for (i = 0; i < nr_trees; i++) {
599 parse_tree(trees[i]);
600 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
601 }
602 if (unpack_trees(nr_trees, t, &opts))
603 return -1;
604 return 0;
605 }
606
607 static void write_tree_trivial(unsigned char *sha1)
608 {
609 if (write_cache_as_tree(sha1, 0, NULL))
610 die(_("git write-tree failed to write a tree"));
611 }
612
613 static const char *merge_argument(struct commit *commit)
614 {
615 if (commit)
616 return sha1_to_hex(commit->object.sha1);
617 else
618 return EMPTY_TREE_SHA1_HEX;
619 }
620
621 int try_merge_command(const char *strategy, size_t xopts_nr,
622 const char **xopts, struct commit_list *common,
623 const char *head_arg, struct commit_list *remotes)
624 {
625 const char **args;
626 int i = 0, x = 0, ret;
627 struct commit_list *j;
628 struct strbuf buf = STRBUF_INIT;
629
630 args = xmalloc((4 + xopts_nr + commit_list_count(common) +
631 commit_list_count(remotes)) * sizeof(char *));
632 strbuf_addf(&buf, "merge-%s", strategy);
633 args[i++] = buf.buf;
634 for (x = 0; x < xopts_nr; x++) {
635 char *s = xmalloc(strlen(xopts[x])+2+1);
636 strcpy(s, "--");
637 strcpy(s+2, xopts[x]);
638 args[i++] = s;
639 }
640 for (j = common; j; j = j->next)
641 args[i++] = xstrdup(merge_argument(j->item));
642 args[i++] = "--";
643 args[i++] = head_arg;
644 for (j = remotes; j; j = j->next)
645 args[i++] = xstrdup(merge_argument(j->item));
646 args[i] = NULL;
647 ret = run_command_v_opt(args, RUN_GIT_CMD);
648 strbuf_release(&buf);
649 i = 1;
650 for (x = 0; x < xopts_nr; x++)
651 free((void *)args[i++]);
652 for (j = common; j; j = j->next)
653 free((void *)args[i++]);
654 i += 2;
655 for (j = remotes; j; j = j->next)
656 free((void *)args[i++]);
657 free(args);
658 discard_cache();
659 if (read_cache() < 0)
660 die(_("failed to read the cache"));
661 resolve_undo_clear();
662
663 return ret;
664 }
665
666 static int try_merge_strategy(const char *strategy, struct commit_list *common,
667 struct commit *head, const char *head_arg)
668 {
669 int index_fd;
670 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
671
672 index_fd = hold_locked_index(lock, 1);
673 refresh_cache(REFRESH_QUIET);
674 if (active_cache_changed &&
675 (write_cache(index_fd, active_cache, active_nr) ||
676 commit_locked_index(lock)))
677 return error(_("Unable to write index."));
678 rollback_lock_file(lock);
679
680 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
681 int clean, x;
682 struct commit *result;
683 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
684 int index_fd;
685 struct commit_list *reversed = NULL;
686 struct merge_options o;
687 struct commit_list *j;
688
689 if (remoteheads->next) {
690 error(_("Not handling anything other than two heads merge."));
691 return 2;
692 }
693
694 init_merge_options(&o);
695 if (!strcmp(strategy, "subtree"))
696 o.subtree_shift = "";
697
698 o.renormalize = option_renormalize;
699 o.show_rename_progress =
700 show_progress == -1 ? isatty(2) : show_progress;
701
702 for (x = 0; x < xopts_nr; x++)
703 if (parse_merge_opt(&o, xopts[x]))
704 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
705
706 o.branch1 = head_arg;
707 o.branch2 = remoteheads->item->util;
708
709 for (j = common; j; j = j->next)
710 commit_list_insert(j->item, &reversed);
711
712 index_fd = hold_locked_index(lock, 1);
713 clean = merge_recursive(&o, head,
714 remoteheads->item, reversed, &result);
715 if (active_cache_changed &&
716 (write_cache(index_fd, active_cache, active_nr) ||
717 commit_locked_index(lock)))
718 die (_("unable to write %s"), get_index_file());
719 rollback_lock_file(lock);
720 return clean ? 0 : 1;
721 } else {
722 return try_merge_command(strategy, xopts_nr, xopts,
723 common, head_arg, remoteheads);
724 }
725 }
726
727 static void count_diff_files(struct diff_queue_struct *q,
728 struct diff_options *opt, void *data)
729 {
730 int *count = data;
731
732 (*count) += q->nr;
733 }
734
735 static int count_unmerged_entries(void)
736 {
737 int i, ret = 0;
738
739 for (i = 0; i < active_nr; i++)
740 if (ce_stage(active_cache[i]))
741 ret++;
742
743 return ret;
744 }
745
746 int checkout_fast_forward(const unsigned char *head, const unsigned char *remote)
747 {
748 struct tree *trees[MAX_UNPACK_TREES];
749 struct unpack_trees_options opts;
750 struct tree_desc t[MAX_UNPACK_TREES];
751 int i, fd, nr_trees = 0;
752 struct dir_struct dir;
753 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
754
755 refresh_cache(REFRESH_QUIET);
756
757 fd = hold_locked_index(lock_file, 1);
758
759 memset(&trees, 0, sizeof(trees));
760 memset(&opts, 0, sizeof(opts));
761 memset(&t, 0, sizeof(t));
762 memset(&dir, 0, sizeof(dir));
763 dir.flags |= DIR_SHOW_IGNORED;
764 dir.exclude_per_dir = ".gitignore";
765 opts.dir = &dir;
766
767 opts.head_idx = 1;
768 opts.src_index = &the_index;
769 opts.dst_index = &the_index;
770 opts.update = 1;
771 opts.verbose_update = 1;
772 opts.merge = 1;
773 opts.fn = twoway_merge;
774 setup_unpack_trees_porcelain(&opts, "merge");
775
776 trees[nr_trees] = parse_tree_indirect(head);
777 if (!trees[nr_trees++])
778 return -1;
779 trees[nr_trees] = parse_tree_indirect(remote);
780 if (!trees[nr_trees++])
781 return -1;
782 for (i = 0; i < nr_trees; i++) {
783 parse_tree(trees[i]);
784 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
785 }
786 if (unpack_trees(nr_trees, t, &opts))
787 return -1;
788 if (write_cache(fd, active_cache, active_nr) ||
789 commit_locked_index(lock_file))
790 die(_("unable to write new index file"));
791 return 0;
792 }
793
794 static void split_merge_strategies(const char *string, struct strategy **list,
795 int *nr, int *alloc)
796 {
797 char *p, *q, *buf;
798
799 if (!string)
800 return;
801
802 buf = xstrdup(string);
803 q = buf;
804 for (;;) {
805 p = strchr(q, ' ');
806 if (!p) {
807 ALLOC_GROW(*list, *nr + 1, *alloc);
808 (*list)[(*nr)++].name = xstrdup(q);
809 free(buf);
810 return;
811 } else {
812 *p = '\0';
813 ALLOC_GROW(*list, *nr + 1, *alloc);
814 (*list)[(*nr)++].name = xstrdup(q);
815 q = ++p;
816 }
817 }
818 }
819
820 static void add_strategies(const char *string, unsigned attr)
821 {
822 struct strategy *list = NULL;
823 int list_alloc = 0, list_nr = 0, i;
824
825 memset(&list, 0, sizeof(list));
826 split_merge_strategies(string, &list, &list_nr, &list_alloc);
827 if (list) {
828 for (i = 0; i < list_nr; i++)
829 append_strategy(get_strategy(list[i].name));
830 return;
831 }
832 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
833 if (all_strategy[i].attr & attr)
834 append_strategy(&all_strategy[i]);
835
836 }
837
838 static void write_merge_msg(void)
839 {
840 int fd = open(git_path("MERGE_MSG"), O_WRONLY | O_CREAT, 0666);
841 if (fd < 0)
842 die_errno(_("Could not open '%s' for writing"),
843 git_path("MERGE_MSG"));
844 if (write_in_full(fd, merge_msg.buf, merge_msg.len) != merge_msg.len)
845 die_errno(_("Could not write to '%s'"), git_path("MERGE_MSG"));
846 close(fd);
847 }
848
849 static void read_merge_msg(void)
850 {
851 strbuf_reset(&merge_msg);
852 if (strbuf_read_file(&merge_msg, git_path("MERGE_MSG"), 0) < 0)
853 die_errno(_("Could not read from '%s'"), git_path("MERGE_MSG"));
854 }
855
856 static void run_prepare_commit_msg(void)
857 {
858 write_merge_msg();
859 run_hook(get_index_file(), "prepare-commit-msg",
860 git_path("MERGE_MSG"), "merge", NULL, NULL);
861 read_merge_msg();
862 }
863
864 static int merge_trivial(struct commit *head)
865 {
866 unsigned char result_tree[20], result_commit[20];
867 struct commit_list *parent = xmalloc(sizeof(*parent));
868
869 write_tree_trivial(result_tree);
870 printf(_("Wonderful.\n"));
871 parent->item = head;
872 parent->next = xmalloc(sizeof(*parent->next));
873 parent->next->item = remoteheads->item;
874 parent->next->next = NULL;
875 run_prepare_commit_msg();
876 commit_tree(merge_msg.buf, result_tree, parent, result_commit, NULL);
877 finish(head, result_commit, "In-index merge");
878 drop_save();
879 return 0;
880 }
881
882 static int finish_automerge(struct commit *head,
883 struct commit_list *common,
884 unsigned char *result_tree,
885 const char *wt_strategy)
886 {
887 struct commit_list *parents = NULL, *j;
888 struct strbuf buf = STRBUF_INIT;
889 unsigned char result_commit[20];
890
891 free_commit_list(common);
892 if (allow_fast_forward) {
893 parents = remoteheads;
894 commit_list_insert(head, &parents);
895 parents = reduce_heads(parents);
896 } else {
897 struct commit_list **pptr = &parents;
898
899 pptr = &commit_list_insert(head,
900 pptr)->next;
901 for (j = remoteheads; j; j = j->next)
902 pptr = &commit_list_insert(j->item, pptr)->next;
903 }
904 free_commit_list(remoteheads);
905 strbuf_addch(&merge_msg, '\n');
906 run_prepare_commit_msg();
907 commit_tree(merge_msg.buf, result_tree, parents, result_commit, NULL);
908 strbuf_addf(&buf, "Merge made by %s.", wt_strategy);
909 finish(head, result_commit, buf.buf);
910 strbuf_release(&buf);
911 drop_save();
912 return 0;
913 }
914
915 static int suggest_conflicts(int renormalizing)
916 {
917 FILE *fp;
918 int pos;
919
920 fp = fopen(git_path("MERGE_MSG"), "a");
921 if (!fp)
922 die_errno(_("Could not open '%s' for writing"),
923 git_path("MERGE_MSG"));
924 fprintf(fp, "\nConflicts:\n");
925 for (pos = 0; pos < active_nr; pos++) {
926 struct cache_entry *ce = active_cache[pos];
927
928 if (ce_stage(ce)) {
929 fprintf(fp, "\t%s\n", ce->name);
930 while (pos + 1 < active_nr &&
931 !strcmp(ce->name,
932 active_cache[pos + 1]->name))
933 pos++;
934 }
935 }
936 fclose(fp);
937 rerere(allow_rerere_auto);
938 printf(_("Automatic merge failed; "
939 "fix conflicts and then commit the result.\n"));
940 return 1;
941 }
942
943 static struct commit *is_old_style_invocation(int argc, const char **argv,
944 const unsigned char *head)
945 {
946 struct commit *second_token = NULL;
947 if (argc > 2) {
948 unsigned char second_sha1[20];
949
950 if (get_sha1(argv[1], second_sha1))
951 return NULL;
952 second_token = lookup_commit_reference_gently(second_sha1, 0);
953 if (!second_token)
954 die(_("'%s' is not a commit"), argv[1]);
955 if (hashcmp(second_token->object.sha1, head))
956 return NULL;
957 }
958 return second_token;
959 }
960
961 static int evaluate_result(void)
962 {
963 int cnt = 0;
964 struct rev_info rev;
965
966 /* Check how many files differ. */
967 init_revisions(&rev, "");
968 setup_revisions(0, NULL, &rev, NULL);
969 rev.diffopt.output_format |=
970 DIFF_FORMAT_CALLBACK;
971 rev.diffopt.format_callback = count_diff_files;
972 rev.diffopt.format_callback_data = &cnt;
973 run_diff_files(&rev, 0);
974
975 /*
976 * Check how many unmerged entries are
977 * there.
978 */
979 cnt += count_unmerged_entries();
980
981 return cnt;
982 }
983
984 /*
985 * Pretend as if the user told us to merge with the tracking
986 * branch we have for the upstream of the current branch
987 */
988 static int setup_with_upstream(const char ***argv)
989 {
990 struct branch *branch = branch_get(NULL);
991 int i;
992 const char **args;
993
994 if (!branch)
995 die(_("No current branch."));
996 if (!branch->remote)
997 die(_("No remote for the current branch."));
998 if (!branch->merge_nr)
999 die(_("No default upstream defined for the current branch."));
1000
1001 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
1002 for (i = 0; i < branch->merge_nr; i++) {
1003 if (!branch->merge[i]->dst)
1004 die(_("No remote tracking branch for %s from %s"),
1005 branch->merge[i]->src, branch->remote_name);
1006 args[i] = branch->merge[i]->dst;
1007 }
1008 args[i] = NULL;
1009 *argv = args;
1010 return i;
1011 }
1012
1013 int cmd_merge(int argc, const char **argv, const char *prefix)
1014 {
1015 unsigned char result_tree[20];
1016 unsigned char stash[20];
1017 unsigned char head_sha1[20];
1018 struct commit *head_commit;
1019 struct strbuf buf = STRBUF_INIT;
1020 const char *head_arg;
1021 int flag, i;
1022 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1023 struct commit_list *common = NULL;
1024 const char *best_strategy = NULL, *wt_strategy = NULL;
1025 struct commit_list **remotes = &remoteheads;
1026
1027 if (argc == 2 && !strcmp(argv[1], "-h"))
1028 usage_with_options(builtin_merge_usage, builtin_merge_options);
1029
1030 /*
1031 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1032 * current branch.
1033 */
1034 branch = resolve_ref("HEAD", head_sha1, 0, &flag);
1035 if (branch && !prefixcmp(branch, "refs/heads/"))
1036 branch += 11;
1037 if (!branch || is_null_sha1(head_sha1))
1038 head_commit = NULL;
1039 else
1040 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1041
1042 git_config(git_merge_config, NULL);
1043
1044 /* for color.ui */
1045 if (diff_use_color_default == -1)
1046 diff_use_color_default = git_use_color_default;
1047
1048 if (branch_mergeoptions)
1049 parse_branch_merge_options(branch_mergeoptions);
1050 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1051 builtin_merge_usage, 0);
1052
1053 if (verbosity < 0 && show_progress == -1)
1054 show_progress = 0;
1055
1056 if (abort_current_merge) {
1057 int nargc = 2;
1058 const char *nargv[] = {"reset", "--merge", NULL};
1059
1060 if (!file_exists(git_path("MERGE_HEAD")))
1061 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1062
1063 /* Invoke 'git reset --merge' */
1064 return cmd_reset(nargc, nargv, prefix);
1065 }
1066
1067 if (read_cache_unmerged())
1068 die_resolve_conflict("merge");
1069
1070 if (file_exists(git_path("MERGE_HEAD"))) {
1071 /*
1072 * There is no unmerged entry, don't advise 'git
1073 * add/rm <file>', just 'git commit'.
1074 */
1075 if (advice_resolve_conflict)
1076 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1077 "Please, commit your changes before you can merge."));
1078 else
1079 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1080 }
1081 if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
1082 if (advice_resolve_conflict)
1083 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1084 "Please, commit your changes before you can merge."));
1085 else
1086 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1087 }
1088 resolve_undo_clear();
1089
1090 if (verbosity < 0)
1091 show_diffstat = 0;
1092
1093 if (squash) {
1094 if (!allow_fast_forward)
1095 die(_("You cannot combine --squash with --no-ff."));
1096 option_commit = 0;
1097 }
1098
1099 if (!allow_fast_forward && fast_forward_only)
1100 die(_("You cannot combine --no-ff with --ff-only."));
1101
1102 if (!abort_current_merge) {
1103 if (!argc && default_to_upstream)
1104 argc = setup_with_upstream(&argv);
1105 else if (argc == 1 && !strcmp(argv[0], "-"))
1106 argv[0] = "@{-1}";
1107 }
1108 if (!argc)
1109 usage_with_options(builtin_merge_usage,
1110 builtin_merge_options);
1111
1112 /*
1113 * This could be traditional "merge <msg> HEAD <commit>..." and
1114 * the way we can tell it is to see if the second token is HEAD,
1115 * but some people might have misused the interface and used a
1116 * committish that is the same as HEAD there instead.
1117 * Traditional format never would have "-m" so it is an
1118 * additional safety measure to check for it.
1119 */
1120
1121 if (!have_message && head_commit &&
1122 is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
1123 strbuf_addstr(&merge_msg, argv[0]);
1124 head_arg = argv[1];
1125 argv += 2;
1126 argc -= 2;
1127 } else if (!head_commit) {
1128 struct object *remote_head;
1129 /*
1130 * If the merged head is a valid one there is no reason
1131 * to forbid "git merge" into a branch yet to be born.
1132 * We do the same for "git pull".
1133 */
1134 if (argc != 1)
1135 die(_("Can merge only exactly one commit into "
1136 "empty head"));
1137 if (squash)
1138 die(_("Squash commit into empty head not supported yet"));
1139 if (!allow_fast_forward)
1140 die(_("Non-fast-forward commit does not make sense into "
1141 "an empty head"));
1142 remote_head = peel_to_type(argv[0], 0, NULL, OBJ_COMMIT);
1143 if (!remote_head)
1144 die(_("%s - not something we can merge"), argv[0]);
1145 read_empty(remote_head->sha1, 0);
1146 update_ref("initial pull", "HEAD", remote_head->sha1, NULL, 0,
1147 DIE_ON_ERR);
1148 return 0;
1149 } else {
1150 struct strbuf merge_names = STRBUF_INIT;
1151
1152 /* We are invoked directly as the first-class UI. */
1153 head_arg = "HEAD";
1154
1155 /*
1156 * All the rest are the commits being merged;
1157 * prepare the standard merge summary message to
1158 * be appended to the given message. If remote
1159 * is invalid we will die later in the common
1160 * codepath so we discard the error in this
1161 * loop.
1162 */
1163 for (i = 0; i < argc; i++)
1164 merge_name(argv[i], &merge_names);
1165
1166 if (!have_message || shortlog_len) {
1167 fmt_merge_msg(&merge_names, &merge_msg, !have_message,
1168 shortlog_len);
1169 if (merge_msg.len)
1170 strbuf_setlen(&merge_msg, merge_msg.len - 1);
1171 }
1172 }
1173
1174 if (!head_commit || !argc)
1175 usage_with_options(builtin_merge_usage,
1176 builtin_merge_options);
1177
1178 strbuf_addstr(&buf, "merge");
1179 for (i = 0; i < argc; i++)
1180 strbuf_addf(&buf, " %s", argv[i]);
1181 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1182 strbuf_reset(&buf);
1183
1184 for (i = 0; i < argc; i++) {
1185 struct object *o;
1186 struct commit *commit;
1187
1188 o = peel_to_type(argv[i], 0, NULL, OBJ_COMMIT);
1189 if (!o)
1190 die(_("%s - not something we can merge"), argv[i]);
1191 commit = lookup_commit(o->sha1);
1192 commit->util = (void *)argv[i];
1193 remotes = &commit_list_insert(commit, remotes)->next;
1194
1195 strbuf_addf(&buf, "GITHEAD_%s", sha1_to_hex(o->sha1));
1196 setenv(buf.buf, argv[i], 1);
1197 strbuf_reset(&buf);
1198 }
1199
1200 if (!use_strategies) {
1201 if (!remoteheads->next)
1202 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1203 else
1204 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1205 }
1206
1207 for (i = 0; i < use_strategies_nr; i++) {
1208 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1209 allow_fast_forward = 0;
1210 if (use_strategies[i]->attr & NO_TRIVIAL)
1211 allow_trivial = 0;
1212 }
1213
1214 if (!remoteheads->next)
1215 common = get_merge_bases(head_commit, remoteheads->item, 1);
1216 else {
1217 struct commit_list *list = remoteheads;
1218 commit_list_insert(head_commit, &list);
1219 common = get_octopus_merge_bases(list);
1220 free(list);
1221 }
1222
1223 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
1224 NULL, 0, DIE_ON_ERR);
1225
1226 if (!common)
1227 ; /* No common ancestors found. We need a real merge. */
1228 else if (!remoteheads->next && !common->next &&
1229 common->item == remoteheads->item) {
1230 /*
1231 * If head can reach all the merge then we are up to date.
1232 * but first the most common case of merging one remote.
1233 */
1234 finish_up_to_date("Already up-to-date.");
1235 return 0;
1236 } else if (allow_fast_forward && !remoteheads->next &&
1237 !common->next &&
1238 !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
1239 /* Again the most common case of merging one remote. */
1240 struct strbuf msg = STRBUF_INIT;
1241 struct object *o;
1242 char hex[41];
1243
1244 strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
1245
1246 if (verbosity >= 0)
1247 printf(_("Updating %s..%s\n"),
1248 hex,
1249 find_unique_abbrev(remoteheads->item->object.sha1,
1250 DEFAULT_ABBREV));
1251 strbuf_addstr(&msg, "Fast-forward");
1252 if (have_message)
1253 strbuf_addstr(&msg,
1254 " (no commit created; -m option ignored)");
1255 o = peel_to_type(sha1_to_hex(remoteheads->item->object.sha1),
1256 0, NULL, OBJ_COMMIT);
1257 if (!o)
1258 return 1;
1259
1260 if (checkout_fast_forward(head_commit->object.sha1, remoteheads->item->object.sha1))
1261 return 1;
1262
1263 finish(head_commit, o->sha1, msg.buf);
1264 drop_save();
1265 return 0;
1266 } else if (!remoteheads->next && common->next)
1267 ;
1268 /*
1269 * We are not doing octopus and not fast-forward. Need
1270 * a real merge.
1271 */
1272 else if (!remoteheads->next && !common->next && option_commit) {
1273 /*
1274 * We are not doing octopus, not fast-forward, and have
1275 * only one common.
1276 */
1277 refresh_cache(REFRESH_QUIET);
1278 if (allow_trivial && !fast_forward_only) {
1279 /* See if it is really trivial. */
1280 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1281 printf(_("Trying really trivial in-index merge...\n"));
1282 if (!read_tree_trivial(common->item->object.sha1,
1283 head_commit->object.sha1, remoteheads->item->object.sha1))
1284 return merge_trivial(head_commit);
1285 printf(_("Nope.\n"));
1286 }
1287 } else {
1288 /*
1289 * An octopus. If we can reach all the remote we are up
1290 * to date.
1291 */
1292 int up_to_date = 1;
1293 struct commit_list *j;
1294
1295 for (j = remoteheads; j; j = j->next) {
1296 struct commit_list *common_one;
1297
1298 /*
1299 * Here we *have* to calculate the individual
1300 * merge_bases again, otherwise "git merge HEAD^
1301 * HEAD^^" would be missed.
1302 */
1303 common_one = get_merge_bases(head_commit, j->item, 1);
1304 if (hashcmp(common_one->item->object.sha1,
1305 j->item->object.sha1)) {
1306 up_to_date = 0;
1307 break;
1308 }
1309 }
1310 if (up_to_date) {
1311 finish_up_to_date("Already up-to-date. Yeeah!");
1312 return 0;
1313 }
1314 }
1315
1316 if (fast_forward_only)
1317 die(_("Not possible to fast-forward, aborting."));
1318
1319 /* We are going to make a new commit. */
1320 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1321
1322 /*
1323 * At this point, we need a real merge. No matter what strategy
1324 * we use, it would operate on the index, possibly affecting the
1325 * working tree, and when resolved cleanly, have the desired
1326 * tree in the index -- this means that the index must be in
1327 * sync with the head commit. The strategies are responsible
1328 * to ensure this.
1329 */
1330 if (use_strategies_nr == 1 ||
1331 /*
1332 * Stash away the local changes so that we can try more than one.
1333 */
1334 save_state(stash))
1335 hashcpy(stash, null_sha1);
1336
1337 for (i = 0; i < use_strategies_nr; i++) {
1338 int ret;
1339 if (i) {
1340 printf(_("Rewinding the tree to pristine...\n"));
1341 restore_state(head_commit->object.sha1, stash);
1342 }
1343 if (use_strategies_nr != 1)
1344 printf(_("Trying merge strategy %s...\n"),
1345 use_strategies[i]->name);
1346 /*
1347 * Remember which strategy left the state in the working
1348 * tree.
1349 */
1350 wt_strategy = use_strategies[i]->name;
1351
1352 ret = try_merge_strategy(use_strategies[i]->name,
1353 common, head_commit, head_arg);
1354 if (!option_commit && !ret) {
1355 merge_was_ok = 1;
1356 /*
1357 * This is necessary here just to avoid writing
1358 * the tree, but later we will *not* exit with
1359 * status code 1 because merge_was_ok is set.
1360 */
1361 ret = 1;
1362 }
1363
1364 if (ret) {
1365 /*
1366 * The backend exits with 1 when conflicts are
1367 * left to be resolved, with 2 when it does not
1368 * handle the given merge at all.
1369 */
1370 if (ret == 1) {
1371 int cnt = evaluate_result();
1372
1373 if (best_cnt <= 0 || cnt <= best_cnt) {
1374 best_strategy = use_strategies[i]->name;
1375 best_cnt = cnt;
1376 }
1377 }
1378 if (merge_was_ok)
1379 break;
1380 else
1381 continue;
1382 }
1383
1384 /* Automerge succeeded. */
1385 write_tree_trivial(result_tree);
1386 automerge_was_ok = 1;
1387 break;
1388 }
1389
1390 /*
1391 * If we have a resulting tree, that means the strategy module
1392 * auto resolved the merge cleanly.
1393 */
1394 if (automerge_was_ok)
1395 return finish_automerge(head_commit, common, result_tree,
1396 wt_strategy);
1397
1398 /*
1399 * Pick the result from the best strategy and have the user fix
1400 * it up.
1401 */
1402 if (!best_strategy) {
1403 restore_state(head_commit->object.sha1, stash);
1404 if (use_strategies_nr > 1)
1405 fprintf(stderr,
1406 _("No merge strategy handled the merge.\n"));
1407 else
1408 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1409 use_strategies[0]->name);
1410 return 2;
1411 } else if (best_strategy == wt_strategy)
1412 ; /* We already have its result in the working tree. */
1413 else {
1414 printf(_("Rewinding the tree to pristine...\n"));
1415 restore_state(head_commit->object.sha1, stash);
1416 printf(_("Using the %s to prepare resolving by hand.\n"),
1417 best_strategy);
1418 try_merge_strategy(best_strategy, common, head_commit, head_arg);
1419 }
1420
1421 if (squash)
1422 finish(head_commit, NULL, NULL);
1423 else {
1424 int fd;
1425 struct commit_list *j;
1426
1427 for (j = remoteheads; j; j = j->next)
1428 strbuf_addf(&buf, "%s\n",
1429 sha1_to_hex(j->item->object.sha1));
1430 fd = open(git_path("MERGE_HEAD"), O_WRONLY | O_CREAT, 0666);
1431 if (fd < 0)
1432 die_errno(_("Could not open '%s' for writing"),
1433 git_path("MERGE_HEAD"));
1434 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1435 die_errno(_("Could not write to '%s'"), git_path("MERGE_HEAD"));
1436 close(fd);
1437 strbuf_addch(&merge_msg, '\n');
1438 write_merge_msg();
1439 fd = open(git_path("MERGE_MODE"), O_WRONLY | O_CREAT | O_TRUNC, 0666);
1440 if (fd < 0)
1441 die_errno(_("Could not open '%s' for writing"),
1442 git_path("MERGE_MODE"));
1443 strbuf_reset(&buf);
1444 if (!allow_fast_forward)
1445 strbuf_addf(&buf, "no-ff");
1446 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1447 die_errno(_("Could not write to '%s'"), git_path("MERGE_MODE"));
1448 close(fd);
1449 }
1450
1451 if (merge_was_ok) {
1452 fprintf(stderr, _("Automatic merge went well; "
1453 "stopped before committing as requested\n"));
1454 return 0;
1455 } else
1456 return suggest_conflicts(option_renormalize);
1457 }