Merge branch '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, option_edit;
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('e', "edit", &option_edit,
193 "edit message before committing"),
194 OPT_BOOLEAN(0, "ff", &allow_fast_forward,
195 "allow fast-forward (default)"),
196 OPT_BOOLEAN(0, "ff-only", &fast_forward_only,
197 "abort if fast-forward is not possible"),
198 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
199 OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
200 "merge strategy to use", option_parse_strategy),
201 OPT_CALLBACK('X', "strategy-option", &xopts, "option=value",
202 "option for selected merge strategy", option_parse_x),
203 OPT_CALLBACK('m', "message", &merge_msg, "message",
204 "merge commit message (for a non-fast-forward merge)",
205 option_parse_message),
206 OPT__VERBOSITY(&verbosity),
207 OPT_BOOLEAN(0, "abort", &abort_current_merge,
208 "abort the current in-progress merge"),
209 OPT_SET_INT(0, "progress", &show_progress, "force progress reporting", 1),
210 OPT_END()
211 };
212
213 /* Cleans up metadata that is uninteresting after a succeeded merge. */
214 static void drop_save(void)
215 {
216 unlink(git_path("MERGE_HEAD"));
217 unlink(git_path("MERGE_MSG"));
218 unlink(git_path("MERGE_MODE"));
219 }
220
221 static int save_state(unsigned char *stash)
222 {
223 int len;
224 struct child_process cp;
225 struct strbuf buffer = STRBUF_INIT;
226 const char *argv[] = {"stash", "create", NULL};
227
228 memset(&cp, 0, sizeof(cp));
229 cp.argv = argv;
230 cp.out = -1;
231 cp.git_cmd = 1;
232
233 if (start_command(&cp))
234 die(_("could not run stash."));
235 len = strbuf_read(&buffer, cp.out, 1024);
236 close(cp.out);
237
238 if (finish_command(&cp) || len < 0)
239 die(_("stash failed"));
240 else if (!len) /* no changes */
241 return -1;
242 strbuf_setlen(&buffer, buffer.len-1);
243 if (get_sha1(buffer.buf, stash))
244 die(_("not a valid object: %s"), buffer.buf);
245 return 0;
246 }
247
248 static void read_empty(unsigned const char *sha1, int verbose)
249 {
250 int i = 0;
251 const char *args[7];
252
253 args[i++] = "read-tree";
254 if (verbose)
255 args[i++] = "-v";
256 args[i++] = "-m";
257 args[i++] = "-u";
258 args[i++] = EMPTY_TREE_SHA1_HEX;
259 args[i++] = sha1_to_hex(sha1);
260 args[i] = NULL;
261
262 if (run_command_v_opt(args, RUN_GIT_CMD))
263 die(_("read-tree failed"));
264 }
265
266 static void reset_hard(unsigned const char *sha1, int verbose)
267 {
268 int i = 0;
269 const char *args[6];
270
271 args[i++] = "read-tree";
272 if (verbose)
273 args[i++] = "-v";
274 args[i++] = "--reset";
275 args[i++] = "-u";
276 args[i++] = sha1_to_hex(sha1);
277 args[i] = NULL;
278
279 if (run_command_v_opt(args, RUN_GIT_CMD))
280 die(_("read-tree failed"));
281 }
282
283 static void restore_state(const unsigned char *head,
284 const unsigned char *stash)
285 {
286 struct strbuf sb = STRBUF_INIT;
287 const char *args[] = { "stash", "apply", NULL, NULL };
288
289 if (is_null_sha1(stash))
290 return;
291
292 reset_hard(head, 1);
293
294 args[2] = sha1_to_hex(stash);
295
296 /*
297 * It is OK to ignore error here, for example when there was
298 * nothing to restore.
299 */
300 run_command_v_opt(args, RUN_GIT_CMD);
301
302 strbuf_release(&sb);
303 refresh_cache(REFRESH_QUIET);
304 }
305
306 /* This is called when no merge was necessary. */
307 static void finish_up_to_date(const char *msg)
308 {
309 if (verbosity >= 0)
310 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
311 drop_save();
312 }
313
314 static void squash_message(struct commit *commit)
315 {
316 struct rev_info rev;
317 struct strbuf out = STRBUF_INIT;
318 struct commit_list *j;
319 int fd;
320 struct pretty_print_context ctx = {0};
321
322 printf(_("Squash commit -- not updating HEAD\n"));
323 fd = open(git_path("SQUASH_MSG"), O_WRONLY | O_CREAT, 0666);
324 if (fd < 0)
325 die_errno(_("Could not write to '%s'"), git_path("SQUASH_MSG"));
326
327 init_revisions(&rev, NULL);
328 rev.ignore_merges = 1;
329 rev.commit_format = CMIT_FMT_MEDIUM;
330
331 commit->object.flags |= UNINTERESTING;
332 add_pending_object(&rev, &commit->object, NULL);
333
334 for (j = remoteheads; j; j = j->next)
335 add_pending_object(&rev, &j->item->object, NULL);
336
337 setup_revisions(0, NULL, &rev, NULL);
338 if (prepare_revision_walk(&rev))
339 die(_("revision walk setup failed"));
340
341 ctx.abbrev = rev.abbrev;
342 ctx.date_mode = rev.date_mode;
343 ctx.fmt = rev.commit_format;
344
345 strbuf_addstr(&out, "Squashed commit of the following:\n");
346 while ((commit = get_revision(&rev)) != NULL) {
347 strbuf_addch(&out, '\n');
348 strbuf_addf(&out, "commit %s\n",
349 sha1_to_hex(commit->object.sha1));
350 pretty_print_commit(&ctx, commit, &out);
351 }
352 if (write(fd, out.buf, out.len) < 0)
353 die_errno(_("Writing SQUASH_MSG"));
354 if (close(fd))
355 die_errno(_("Finishing SQUASH_MSG"));
356 strbuf_release(&out);
357 }
358
359 static void finish(struct commit *head_commit,
360 const unsigned char *new_head, const char *msg)
361 {
362 struct strbuf reflog_message = STRBUF_INIT;
363 const unsigned char *head = head_commit->object.sha1;
364
365 if (!msg)
366 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
367 else {
368 if (verbosity >= 0)
369 printf("%s\n", msg);
370 strbuf_addf(&reflog_message, "%s: %s",
371 getenv("GIT_REFLOG_ACTION"), msg);
372 }
373 if (squash) {
374 squash_message(head_commit);
375 } else {
376 if (verbosity >= 0 && !merge_msg.len)
377 printf(_("No merge message -- not updating HEAD\n"));
378 else {
379 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
380 update_ref(reflog_message.buf, "HEAD",
381 new_head, head, 0,
382 DIE_ON_ERR);
383 /*
384 * We ignore errors in 'gc --auto', since the
385 * user should see them.
386 */
387 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
388 }
389 }
390 if (new_head && show_diffstat) {
391 struct diff_options opts;
392 diff_setup(&opts);
393 opts.output_format |=
394 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
395 opts.detect_rename = DIFF_DETECT_RENAME;
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 static struct object *want_commit(const char *name)
410 {
411 struct object *obj;
412 unsigned char sha1[20];
413 if (get_sha1(name, sha1))
414 return NULL;
415 obj = parse_object(sha1);
416 return peel_to_type(name, 0, obj, OBJ_COMMIT);
417 }
418
419 /* Get the name for the merge commit's message. */
420 static void merge_name(const char *remote, struct strbuf *msg)
421 {
422 struct object *remote_head;
423 unsigned char branch_head[20], buf_sha[20];
424 struct strbuf buf = STRBUF_INIT;
425 struct strbuf bname = STRBUF_INIT;
426 const char *ptr;
427 char *found_ref;
428 int len, early;
429
430 strbuf_branchname(&bname, remote);
431 remote = bname.buf;
432
433 memset(branch_head, 0, sizeof(branch_head));
434 remote_head = want_commit(remote);
435 if (!remote_head)
436 die(_("'%s' does not point to a commit"), remote);
437
438 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
439 if (!prefixcmp(found_ref, "refs/heads/")) {
440 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
441 sha1_to_hex(branch_head), remote);
442 goto cleanup;
443 }
444 if (!prefixcmp(found_ref, "refs/remotes/")) {
445 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
446 sha1_to_hex(branch_head), remote);
447 goto cleanup;
448 }
449 }
450
451 /* See if remote matches <name>^^^.. or <name>~<number> */
452 for (len = 0, ptr = remote + strlen(remote);
453 remote < ptr && ptr[-1] == '^';
454 ptr--)
455 len++;
456 if (len)
457 early = 1;
458 else {
459 early = 0;
460 ptr = strrchr(remote, '~');
461 if (ptr) {
462 int seen_nonzero = 0;
463
464 len++; /* count ~ */
465 while (*++ptr && isdigit(*ptr)) {
466 seen_nonzero |= (*ptr != '0');
467 len++;
468 }
469 if (*ptr)
470 len = 0; /* not ...~<number> */
471 else if (seen_nonzero)
472 early = 1;
473 else if (len == 1)
474 early = 1; /* "name~" is "name~1"! */
475 }
476 }
477 if (len) {
478 struct strbuf truname = STRBUF_INIT;
479 strbuf_addstr(&truname, "refs/heads/");
480 strbuf_addstr(&truname, remote);
481 strbuf_setlen(&truname, truname.len - len);
482 if (resolve_ref(truname.buf, buf_sha, 1, NULL)) {
483 strbuf_addf(msg,
484 "%s\t\tbranch '%s'%s of .\n",
485 sha1_to_hex(remote_head->sha1),
486 truname.buf + 11,
487 (early ? " (early part)" : ""));
488 strbuf_release(&truname);
489 goto cleanup;
490 }
491 }
492
493 if (!strcmp(remote, "FETCH_HEAD") &&
494 !access(git_path("FETCH_HEAD"), R_OK)) {
495 FILE *fp;
496 struct strbuf line = STRBUF_INIT;
497 char *ptr;
498
499 fp = fopen(git_path("FETCH_HEAD"), "r");
500 if (!fp)
501 die_errno(_("could not open '%s' for reading"),
502 git_path("FETCH_HEAD"));
503 strbuf_getline(&line, fp, '\n');
504 fclose(fp);
505 ptr = strstr(line.buf, "\tnot-for-merge\t");
506 if (ptr)
507 strbuf_remove(&line, ptr-line.buf+1, 13);
508 strbuf_addbuf(msg, &line);
509 strbuf_release(&line);
510 goto cleanup;
511 }
512 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
513 sha1_to_hex(remote_head->sha1), remote);
514 cleanup:
515 strbuf_release(&buf);
516 strbuf_release(&bname);
517 }
518
519 static void parse_branch_merge_options(char *bmo)
520 {
521 const char **argv;
522 int argc;
523
524 if (!bmo)
525 return;
526 argc = split_cmdline(bmo, &argv);
527 if (argc < 0)
528 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
529 split_cmdline_strerror(argc));
530 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
531 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
532 argc++;
533 argv[0] = "branch.*.mergeoptions";
534 parse_options(argc, argv, NULL, builtin_merge_options,
535 builtin_merge_usage, 0);
536 free(argv);
537 }
538
539 static int git_merge_config(const char *k, const char *v, void *cb)
540 {
541 if (branch && !prefixcmp(k, "branch.") &&
542 !prefixcmp(k + 7, branch) &&
543 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
544 free(branch_mergeoptions);
545 branch_mergeoptions = xstrdup(v);
546 return 0;
547 }
548
549 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
550 show_diffstat = git_config_bool(k, v);
551 else if (!strcmp(k, "pull.twohead"))
552 return git_config_string(&pull_twohead, k, v);
553 else if (!strcmp(k, "pull.octopus"))
554 return git_config_string(&pull_octopus, k, v);
555 else if (!strcmp(k, "merge.renormalize"))
556 option_renormalize = git_config_bool(k, v);
557 else if (!strcmp(k, "merge.log") || !strcmp(k, "merge.summary")) {
558 int is_bool;
559 shortlog_len = git_config_bool_or_int(k, v, &is_bool);
560 if (!is_bool && shortlog_len < 0)
561 return error(_("%s: negative length %s"), k, v);
562 if (is_bool && shortlog_len)
563 shortlog_len = DEFAULT_MERGE_LOG_LEN;
564 return 0;
565 } else if (!strcmp(k, "merge.ff")) {
566 int boolval = git_config_maybe_bool(k, v);
567 if (0 <= boolval) {
568 allow_fast_forward = boolval;
569 } else if (v && !strcmp(v, "only")) {
570 allow_fast_forward = 1;
571 fast_forward_only = 1;
572 } /* do not barf on values from future versions of git */
573 return 0;
574 } else if (!strcmp(k, "merge.defaulttoupstream")) {
575 default_to_upstream = git_config_bool(k, v);
576 return 0;
577 }
578 return git_diff_ui_config(k, v, cb);
579 }
580
581 static int read_tree_trivial(unsigned char *common, unsigned char *head,
582 unsigned char *one)
583 {
584 int i, nr_trees = 0;
585 struct tree *trees[MAX_UNPACK_TREES];
586 struct tree_desc t[MAX_UNPACK_TREES];
587 struct unpack_trees_options opts;
588
589 memset(&opts, 0, sizeof(opts));
590 opts.head_idx = 2;
591 opts.src_index = &the_index;
592 opts.dst_index = &the_index;
593 opts.update = 1;
594 opts.verbose_update = 1;
595 opts.trivial_merges_only = 1;
596 opts.merge = 1;
597 trees[nr_trees] = parse_tree_indirect(common);
598 if (!trees[nr_trees++])
599 return -1;
600 trees[nr_trees] = parse_tree_indirect(head);
601 if (!trees[nr_trees++])
602 return -1;
603 trees[nr_trees] = parse_tree_indirect(one);
604 if (!trees[nr_trees++])
605 return -1;
606 opts.fn = threeway_merge;
607 cache_tree_free(&active_cache_tree);
608 for (i = 0; i < nr_trees; i++) {
609 parse_tree(trees[i]);
610 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
611 }
612 if (unpack_trees(nr_trees, t, &opts))
613 return -1;
614 return 0;
615 }
616
617 static void write_tree_trivial(unsigned char *sha1)
618 {
619 if (write_cache_as_tree(sha1, 0, NULL))
620 die(_("git write-tree failed to write a tree"));
621 }
622
623 static const char *merge_argument(struct commit *commit)
624 {
625 if (commit)
626 return sha1_to_hex(commit->object.sha1);
627 else
628 return EMPTY_TREE_SHA1_HEX;
629 }
630
631 int try_merge_command(const char *strategy, size_t xopts_nr,
632 const char **xopts, struct commit_list *common,
633 const char *head_arg, struct commit_list *remotes)
634 {
635 const char **args;
636 int i = 0, x = 0, ret;
637 struct commit_list *j;
638 struct strbuf buf = STRBUF_INIT;
639
640 args = xmalloc((4 + xopts_nr + commit_list_count(common) +
641 commit_list_count(remotes)) * sizeof(char *));
642 strbuf_addf(&buf, "merge-%s", strategy);
643 args[i++] = buf.buf;
644 for (x = 0; x < xopts_nr; x++) {
645 char *s = xmalloc(strlen(xopts[x])+2+1);
646 strcpy(s, "--");
647 strcpy(s+2, xopts[x]);
648 args[i++] = s;
649 }
650 for (j = common; j; j = j->next)
651 args[i++] = xstrdup(merge_argument(j->item));
652 args[i++] = "--";
653 args[i++] = head_arg;
654 for (j = remotes; j; j = j->next)
655 args[i++] = xstrdup(merge_argument(j->item));
656 args[i] = NULL;
657 ret = run_command_v_opt(args, RUN_GIT_CMD);
658 strbuf_release(&buf);
659 i = 1;
660 for (x = 0; x < xopts_nr; x++)
661 free((void *)args[i++]);
662 for (j = common; j; j = j->next)
663 free((void *)args[i++]);
664 i += 2;
665 for (j = remotes; j; j = j->next)
666 free((void *)args[i++]);
667 free(args);
668 discard_cache();
669 if (read_cache() < 0)
670 die(_("failed to read the cache"));
671 resolve_undo_clear();
672
673 return ret;
674 }
675
676 static int try_merge_strategy(const char *strategy, struct commit_list *common,
677 struct commit *head, const char *head_arg)
678 {
679 int index_fd;
680 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
681
682 index_fd = hold_locked_index(lock, 1);
683 refresh_cache(REFRESH_QUIET);
684 if (active_cache_changed &&
685 (write_cache(index_fd, active_cache, active_nr) ||
686 commit_locked_index(lock)))
687 return error(_("Unable to write index."));
688 rollback_lock_file(lock);
689
690 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
691 int clean, x;
692 struct commit *result;
693 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
694 int index_fd;
695 struct commit_list *reversed = NULL;
696 struct merge_options o;
697 struct commit_list *j;
698
699 if (remoteheads->next) {
700 error(_("Not handling anything other than two heads merge."));
701 return 2;
702 }
703
704 init_merge_options(&o);
705 if (!strcmp(strategy, "subtree"))
706 o.subtree_shift = "";
707
708 o.renormalize = option_renormalize;
709 o.show_rename_progress =
710 show_progress == -1 ? isatty(2) : show_progress;
711
712 for (x = 0; x < xopts_nr; x++)
713 if (parse_merge_opt(&o, xopts[x]))
714 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
715
716 o.branch1 = head_arg;
717 o.branch2 = remoteheads->item->util;
718
719 for (j = common; j; j = j->next)
720 commit_list_insert(j->item, &reversed);
721
722 index_fd = hold_locked_index(lock, 1);
723 clean = merge_recursive(&o, head,
724 remoteheads->item, reversed, &result);
725 if (active_cache_changed &&
726 (write_cache(index_fd, active_cache, active_nr) ||
727 commit_locked_index(lock)))
728 die (_("unable to write %s"), get_index_file());
729 rollback_lock_file(lock);
730 return clean ? 0 : 1;
731 } else {
732 return try_merge_command(strategy, xopts_nr, xopts,
733 common, head_arg, remoteheads);
734 }
735 }
736
737 static void count_diff_files(struct diff_queue_struct *q,
738 struct diff_options *opt, void *data)
739 {
740 int *count = data;
741
742 (*count) += q->nr;
743 }
744
745 static int count_unmerged_entries(void)
746 {
747 int i, ret = 0;
748
749 for (i = 0; i < active_nr; i++)
750 if (ce_stage(active_cache[i]))
751 ret++;
752
753 return ret;
754 }
755
756 int checkout_fast_forward(const unsigned char *head, const unsigned char *remote)
757 {
758 struct tree *trees[MAX_UNPACK_TREES];
759 struct unpack_trees_options opts;
760 struct tree_desc t[MAX_UNPACK_TREES];
761 int i, fd, nr_trees = 0;
762 struct dir_struct dir;
763 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
764
765 refresh_cache(REFRESH_QUIET);
766
767 fd = hold_locked_index(lock_file, 1);
768
769 memset(&trees, 0, sizeof(trees));
770 memset(&opts, 0, sizeof(opts));
771 memset(&t, 0, sizeof(t));
772 memset(&dir, 0, sizeof(dir));
773 dir.flags |= DIR_SHOW_IGNORED;
774 dir.exclude_per_dir = ".gitignore";
775 opts.dir = &dir;
776
777 opts.head_idx = 1;
778 opts.src_index = &the_index;
779 opts.dst_index = &the_index;
780 opts.update = 1;
781 opts.verbose_update = 1;
782 opts.merge = 1;
783 opts.fn = twoway_merge;
784 setup_unpack_trees_porcelain(&opts, "merge");
785
786 trees[nr_trees] = parse_tree_indirect(head);
787 if (!trees[nr_trees++])
788 return -1;
789 trees[nr_trees] = parse_tree_indirect(remote);
790 if (!trees[nr_trees++])
791 return -1;
792 for (i = 0; i < nr_trees; i++) {
793 parse_tree(trees[i]);
794 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
795 }
796 if (unpack_trees(nr_trees, t, &opts))
797 return -1;
798 if (write_cache(fd, active_cache, active_nr) ||
799 commit_locked_index(lock_file))
800 die(_("unable to write new index file"));
801 return 0;
802 }
803
804 static void split_merge_strategies(const char *string, struct strategy **list,
805 int *nr, int *alloc)
806 {
807 char *p, *q, *buf;
808
809 if (!string)
810 return;
811
812 buf = xstrdup(string);
813 q = buf;
814 for (;;) {
815 p = strchr(q, ' ');
816 if (!p) {
817 ALLOC_GROW(*list, *nr + 1, *alloc);
818 (*list)[(*nr)++].name = xstrdup(q);
819 free(buf);
820 return;
821 } else {
822 *p = '\0';
823 ALLOC_GROW(*list, *nr + 1, *alloc);
824 (*list)[(*nr)++].name = xstrdup(q);
825 q = ++p;
826 }
827 }
828 }
829
830 static void add_strategies(const char *string, unsigned attr)
831 {
832 struct strategy *list = NULL;
833 int list_alloc = 0, list_nr = 0, i;
834
835 memset(&list, 0, sizeof(list));
836 split_merge_strategies(string, &list, &list_nr, &list_alloc);
837 if (list) {
838 for (i = 0; i < list_nr; i++)
839 append_strategy(get_strategy(list[i].name));
840 return;
841 }
842 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
843 if (all_strategy[i].attr & attr)
844 append_strategy(&all_strategy[i]);
845
846 }
847
848 static void write_merge_msg(struct strbuf *msg)
849 {
850 int fd = open(git_path("MERGE_MSG"), O_WRONLY | O_CREAT, 0666);
851 if (fd < 0)
852 die_errno(_("Could not open '%s' for writing"),
853 git_path("MERGE_MSG"));
854 if (write_in_full(fd, msg->buf, msg->len) != msg->len)
855 die_errno(_("Could not write to '%s'"), git_path("MERGE_MSG"));
856 close(fd);
857 }
858
859 static void read_merge_msg(struct strbuf *msg)
860 {
861 strbuf_reset(msg);
862 if (strbuf_read_file(msg, git_path("MERGE_MSG"), 0) < 0)
863 die_errno(_("Could not read from '%s'"), git_path("MERGE_MSG"));
864 }
865
866 static void write_merge_state(void);
867 static void abort_commit(const char *err_msg)
868 {
869 if (err_msg)
870 error("%s", err_msg);
871 fprintf(stderr,
872 _("Not committing merge; use 'git commit' to complete the merge.\n"));
873 write_merge_state();
874 exit(1);
875 }
876
877 static void prepare_to_commit(void)
878 {
879 struct strbuf msg = STRBUF_INIT;
880 strbuf_addbuf(&msg, &merge_msg);
881 strbuf_addch(&msg, '\n');
882 write_merge_msg(&msg);
883 run_hook(get_index_file(), "prepare-commit-msg",
884 git_path("MERGE_MSG"), "merge", NULL, NULL);
885 if (option_edit) {
886 if (launch_editor(git_path("MERGE_MSG"), NULL, NULL))
887 abort_commit(NULL);
888 }
889 read_merge_msg(&msg);
890 stripspace(&msg, option_edit);
891 if (!msg.len)
892 abort_commit(_("Empty commit message."));
893 strbuf_release(&merge_msg);
894 strbuf_addbuf(&merge_msg, &msg);
895 strbuf_release(&msg);
896 }
897
898 static int merge_trivial(struct commit *head)
899 {
900 unsigned char result_tree[20], result_commit[20];
901 struct commit_list *parent = xmalloc(sizeof(*parent));
902
903 write_tree_trivial(result_tree);
904 printf(_("Wonderful.\n"));
905 parent->item = head;
906 parent->next = xmalloc(sizeof(*parent->next));
907 parent->next->item = remoteheads->item;
908 parent->next->next = NULL;
909 prepare_to_commit();
910 commit_tree(merge_msg.buf, result_tree, parent, result_commit, NULL);
911 finish(head, result_commit, "In-index merge");
912 drop_save();
913 return 0;
914 }
915
916 static int finish_automerge(struct commit *head,
917 struct commit_list *common,
918 unsigned char *result_tree,
919 const char *wt_strategy)
920 {
921 struct commit_list *parents = NULL, *j;
922 struct strbuf buf = STRBUF_INIT;
923 unsigned char result_commit[20];
924
925 free_commit_list(common);
926 if (allow_fast_forward) {
927 parents = remoteheads;
928 commit_list_insert(head, &parents);
929 parents = reduce_heads(parents);
930 } else {
931 struct commit_list **pptr = &parents;
932
933 pptr = &commit_list_insert(head,
934 pptr)->next;
935 for (j = remoteheads; j; j = j->next)
936 pptr = &commit_list_insert(j->item, pptr)->next;
937 }
938 strbuf_addch(&merge_msg, '\n');
939 prepare_to_commit();
940 free_commit_list(remoteheads);
941 commit_tree(merge_msg.buf, result_tree, parents, result_commit, NULL);
942 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
943 finish(head, result_commit, buf.buf);
944 strbuf_release(&buf);
945 drop_save();
946 return 0;
947 }
948
949 static int suggest_conflicts(int renormalizing)
950 {
951 FILE *fp;
952 int pos;
953
954 fp = fopen(git_path("MERGE_MSG"), "a");
955 if (!fp)
956 die_errno(_("Could not open '%s' for writing"),
957 git_path("MERGE_MSG"));
958 fprintf(fp, "\nConflicts:\n");
959 for (pos = 0; pos < active_nr; pos++) {
960 struct cache_entry *ce = active_cache[pos];
961
962 if (ce_stage(ce)) {
963 fprintf(fp, "\t%s\n", ce->name);
964 while (pos + 1 < active_nr &&
965 !strcmp(ce->name,
966 active_cache[pos + 1]->name))
967 pos++;
968 }
969 }
970 fclose(fp);
971 rerere(allow_rerere_auto);
972 printf(_("Automatic merge failed; "
973 "fix conflicts and then commit the result.\n"));
974 return 1;
975 }
976
977 static struct commit *is_old_style_invocation(int argc, const char **argv,
978 const unsigned char *head)
979 {
980 struct commit *second_token = NULL;
981 if (argc > 2) {
982 unsigned char second_sha1[20];
983
984 if (get_sha1(argv[1], second_sha1))
985 return NULL;
986 second_token = lookup_commit_reference_gently(second_sha1, 0);
987 if (!second_token)
988 die(_("'%s' is not a commit"), argv[1]);
989 if (hashcmp(second_token->object.sha1, head))
990 return NULL;
991 }
992 return second_token;
993 }
994
995 static int evaluate_result(void)
996 {
997 int cnt = 0;
998 struct rev_info rev;
999
1000 /* Check how many files differ. */
1001 init_revisions(&rev, "");
1002 setup_revisions(0, NULL, &rev, NULL);
1003 rev.diffopt.output_format |=
1004 DIFF_FORMAT_CALLBACK;
1005 rev.diffopt.format_callback = count_diff_files;
1006 rev.diffopt.format_callback_data = &cnt;
1007 run_diff_files(&rev, 0);
1008
1009 /*
1010 * Check how many unmerged entries are
1011 * there.
1012 */
1013 cnt += count_unmerged_entries();
1014
1015 return cnt;
1016 }
1017
1018 /*
1019 * Pretend as if the user told us to merge with the tracking
1020 * branch we have for the upstream of the current branch
1021 */
1022 static int setup_with_upstream(const char ***argv)
1023 {
1024 struct branch *branch = branch_get(NULL);
1025 int i;
1026 const char **args;
1027
1028 if (!branch)
1029 die(_("No current branch."));
1030 if (!branch->remote)
1031 die(_("No remote for the current branch."));
1032 if (!branch->merge_nr)
1033 die(_("No default upstream defined for the current branch."));
1034
1035 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
1036 for (i = 0; i < branch->merge_nr; i++) {
1037 if (!branch->merge[i]->dst)
1038 die(_("No remote tracking branch for %s from %s"),
1039 branch->merge[i]->src, branch->remote_name);
1040 args[i] = branch->merge[i]->dst;
1041 }
1042 args[i] = NULL;
1043 *argv = args;
1044 return i;
1045 }
1046
1047 static void write_merge_state(void)
1048 {
1049 int fd;
1050 struct commit_list *j;
1051 struct strbuf buf = STRBUF_INIT;
1052
1053 for (j = remoteheads; j; j = j->next)
1054 strbuf_addf(&buf, "%s\n",
1055 sha1_to_hex(j->item->object.sha1));
1056 fd = open(git_path("MERGE_HEAD"), O_WRONLY | O_CREAT, 0666);
1057 if (fd < 0)
1058 die_errno(_("Could not open '%s' for writing"),
1059 git_path("MERGE_HEAD"));
1060 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1061 die_errno(_("Could not write to '%s'"), git_path("MERGE_HEAD"));
1062 close(fd);
1063 strbuf_addch(&merge_msg, '\n');
1064 write_merge_msg(&merge_msg);
1065 fd = open(git_path("MERGE_MODE"), O_WRONLY | O_CREAT | O_TRUNC, 0666);
1066 if (fd < 0)
1067 die_errno(_("Could not open '%s' for writing"),
1068 git_path("MERGE_MODE"));
1069 strbuf_reset(&buf);
1070 if (!allow_fast_forward)
1071 strbuf_addf(&buf, "no-ff");
1072 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1073 die_errno(_("Could not write to '%s'"), git_path("MERGE_MODE"));
1074 close(fd);
1075 }
1076
1077 int cmd_merge(int argc, const char **argv, const char *prefix)
1078 {
1079 unsigned char result_tree[20];
1080 unsigned char stash[20];
1081 unsigned char head_sha1[20];
1082 struct commit *head_commit;
1083 struct strbuf buf = STRBUF_INIT;
1084 const char *head_arg;
1085 int flag, i;
1086 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1087 struct commit_list *common = NULL;
1088 const char *best_strategy = NULL, *wt_strategy = NULL;
1089 struct commit_list **remotes = &remoteheads;
1090
1091 if (argc == 2 && !strcmp(argv[1], "-h"))
1092 usage_with_options(builtin_merge_usage, builtin_merge_options);
1093
1094 /*
1095 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1096 * current branch.
1097 */
1098 branch = resolve_ref("HEAD", head_sha1, 0, &flag);
1099 if (branch && !prefixcmp(branch, "refs/heads/"))
1100 branch += 11;
1101 if (!branch || is_null_sha1(head_sha1))
1102 head_commit = NULL;
1103 else
1104 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1105
1106 git_config(git_merge_config, NULL);
1107
1108 if (branch_mergeoptions)
1109 parse_branch_merge_options(branch_mergeoptions);
1110 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1111 builtin_merge_usage, 0);
1112
1113 if (verbosity < 0 && show_progress == -1)
1114 show_progress = 0;
1115
1116 if (abort_current_merge) {
1117 int nargc = 2;
1118 const char *nargv[] = {"reset", "--merge", NULL};
1119
1120 if (!file_exists(git_path("MERGE_HEAD")))
1121 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1122
1123 /* Invoke 'git reset --merge' */
1124 return cmd_reset(nargc, nargv, prefix);
1125 }
1126
1127 if (read_cache_unmerged())
1128 die_resolve_conflict("merge");
1129
1130 if (file_exists(git_path("MERGE_HEAD"))) {
1131 /*
1132 * There is no unmerged entry, don't advise 'git
1133 * add/rm <file>', just 'git commit'.
1134 */
1135 if (advice_resolve_conflict)
1136 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1137 "Please, commit your changes before you can merge."));
1138 else
1139 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1140 }
1141 if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
1142 if (advice_resolve_conflict)
1143 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1144 "Please, commit your changes before you can merge."));
1145 else
1146 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1147 }
1148 resolve_undo_clear();
1149
1150 if (verbosity < 0)
1151 show_diffstat = 0;
1152
1153 if (squash) {
1154 if (!allow_fast_forward)
1155 die(_("You cannot combine --squash with --no-ff."));
1156 option_commit = 0;
1157 }
1158
1159 if (!allow_fast_forward && fast_forward_only)
1160 die(_("You cannot combine --no-ff with --ff-only."));
1161
1162 if (!abort_current_merge) {
1163 if (!argc && default_to_upstream)
1164 argc = setup_with_upstream(&argv);
1165 else if (argc == 1 && !strcmp(argv[0], "-"))
1166 argv[0] = "@{-1}";
1167 }
1168 if (!argc)
1169 usage_with_options(builtin_merge_usage,
1170 builtin_merge_options);
1171
1172 /*
1173 * This could be traditional "merge <msg> HEAD <commit>..." and
1174 * the way we can tell it is to see if the second token is HEAD,
1175 * but some people might have misused the interface and used a
1176 * committish that is the same as HEAD there instead.
1177 * Traditional format never would have "-m" so it is an
1178 * additional safety measure to check for it.
1179 */
1180
1181 if (!have_message && head_commit &&
1182 is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
1183 strbuf_addstr(&merge_msg, argv[0]);
1184 head_arg = argv[1];
1185 argv += 2;
1186 argc -= 2;
1187 } else if (!head_commit) {
1188 struct object *remote_head;
1189 /*
1190 * If the merged head is a valid one there is no reason
1191 * to forbid "git merge" into a branch yet to be born.
1192 * We do the same for "git pull".
1193 */
1194 if (argc != 1)
1195 die(_("Can merge only exactly one commit into "
1196 "empty head"));
1197 if (squash)
1198 die(_("Squash commit into empty head not supported yet"));
1199 if (!allow_fast_forward)
1200 die(_("Non-fast-forward commit does not make sense into "
1201 "an empty head"));
1202 remote_head = want_commit(argv[0]);
1203 if (!remote_head)
1204 die(_("%s - not something we can merge"), argv[0]);
1205 read_empty(remote_head->sha1, 0);
1206 update_ref("initial pull", "HEAD", remote_head->sha1, NULL, 0,
1207 DIE_ON_ERR);
1208 return 0;
1209 } else {
1210 struct strbuf merge_names = STRBUF_INIT;
1211
1212 /* We are invoked directly as the first-class UI. */
1213 head_arg = "HEAD";
1214
1215 /*
1216 * All the rest are the commits being merged;
1217 * prepare the standard merge summary message to
1218 * be appended to the given message. If remote
1219 * is invalid we will die later in the common
1220 * codepath so we discard the error in this
1221 * loop.
1222 */
1223 for (i = 0; i < argc; i++)
1224 merge_name(argv[i], &merge_names);
1225
1226 if (!have_message || shortlog_len) {
1227 fmt_merge_msg(&merge_names, &merge_msg, !have_message,
1228 shortlog_len);
1229 if (merge_msg.len)
1230 strbuf_setlen(&merge_msg, merge_msg.len - 1);
1231 }
1232 }
1233
1234 if (!head_commit || !argc)
1235 usage_with_options(builtin_merge_usage,
1236 builtin_merge_options);
1237
1238 strbuf_addstr(&buf, "merge");
1239 for (i = 0; i < argc; i++)
1240 strbuf_addf(&buf, " %s", argv[i]);
1241 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1242 strbuf_reset(&buf);
1243
1244 for (i = 0; i < argc; i++) {
1245 struct object *o;
1246 struct commit *commit;
1247
1248 o = want_commit(argv[i]);
1249 if (!o)
1250 die(_("%s - not something we can merge"), argv[i]);
1251 commit = lookup_commit(o->sha1);
1252 commit->util = (void *)argv[i];
1253 remotes = &commit_list_insert(commit, remotes)->next;
1254
1255 strbuf_addf(&buf, "GITHEAD_%s", sha1_to_hex(o->sha1));
1256 setenv(buf.buf, argv[i], 1);
1257 strbuf_reset(&buf);
1258 }
1259
1260 if (!use_strategies) {
1261 if (!remoteheads->next)
1262 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1263 else
1264 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1265 }
1266
1267 for (i = 0; i < use_strategies_nr; i++) {
1268 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1269 allow_fast_forward = 0;
1270 if (use_strategies[i]->attr & NO_TRIVIAL)
1271 allow_trivial = 0;
1272 }
1273
1274 if (!remoteheads->next)
1275 common = get_merge_bases(head_commit, remoteheads->item, 1);
1276 else {
1277 struct commit_list *list = remoteheads;
1278 commit_list_insert(head_commit, &list);
1279 common = get_octopus_merge_bases(list);
1280 free(list);
1281 }
1282
1283 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
1284 NULL, 0, DIE_ON_ERR);
1285
1286 if (!common)
1287 ; /* No common ancestors found. We need a real merge. */
1288 else if (!remoteheads->next && !common->next &&
1289 common->item == remoteheads->item) {
1290 /*
1291 * If head can reach all the merge then we are up to date.
1292 * but first the most common case of merging one remote.
1293 */
1294 finish_up_to_date("Already up-to-date.");
1295 return 0;
1296 } else if (allow_fast_forward && !remoteheads->next &&
1297 !common->next &&
1298 !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
1299 /* Again the most common case of merging one remote. */
1300 struct strbuf msg = STRBUF_INIT;
1301 struct object *o;
1302 char hex[41];
1303
1304 strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
1305
1306 if (verbosity >= 0)
1307 printf(_("Updating %s..%s\n"),
1308 hex,
1309 find_unique_abbrev(remoteheads->item->object.sha1,
1310 DEFAULT_ABBREV));
1311 strbuf_addstr(&msg, "Fast-forward");
1312 if (have_message)
1313 strbuf_addstr(&msg,
1314 " (no commit created; -m option ignored)");
1315 o = want_commit(sha1_to_hex(remoteheads->item->object.sha1));
1316 if (!o)
1317 return 1;
1318
1319 if (checkout_fast_forward(head_commit->object.sha1, remoteheads->item->object.sha1))
1320 return 1;
1321
1322 finish(head_commit, o->sha1, msg.buf);
1323 drop_save();
1324 return 0;
1325 } else if (!remoteheads->next && common->next)
1326 ;
1327 /*
1328 * We are not doing octopus and not fast-forward. Need
1329 * a real merge.
1330 */
1331 else if (!remoteheads->next && !common->next && option_commit) {
1332 /*
1333 * We are not doing octopus, not fast-forward, and have
1334 * only one common.
1335 */
1336 refresh_cache(REFRESH_QUIET);
1337 if (allow_trivial && !fast_forward_only) {
1338 /* See if it is really trivial. */
1339 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1340 printf(_("Trying really trivial in-index merge...\n"));
1341 if (!read_tree_trivial(common->item->object.sha1,
1342 head_commit->object.sha1, remoteheads->item->object.sha1))
1343 return merge_trivial(head_commit);
1344 printf(_("Nope.\n"));
1345 }
1346 } else {
1347 /*
1348 * An octopus. If we can reach all the remote we are up
1349 * to date.
1350 */
1351 int up_to_date = 1;
1352 struct commit_list *j;
1353
1354 for (j = remoteheads; j; j = j->next) {
1355 struct commit_list *common_one;
1356
1357 /*
1358 * Here we *have* to calculate the individual
1359 * merge_bases again, otherwise "git merge HEAD^
1360 * HEAD^^" would be missed.
1361 */
1362 common_one = get_merge_bases(head_commit, j->item, 1);
1363 if (hashcmp(common_one->item->object.sha1,
1364 j->item->object.sha1)) {
1365 up_to_date = 0;
1366 break;
1367 }
1368 }
1369 if (up_to_date) {
1370 finish_up_to_date("Already up-to-date. Yeeah!");
1371 return 0;
1372 }
1373 }
1374
1375 if (fast_forward_only)
1376 die(_("Not possible to fast-forward, aborting."));
1377
1378 /* We are going to make a new commit. */
1379 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1380
1381 /*
1382 * At this point, we need a real merge. No matter what strategy
1383 * we use, it would operate on the index, possibly affecting the
1384 * working tree, and when resolved cleanly, have the desired
1385 * tree in the index -- this means that the index must be in
1386 * sync with the head commit. The strategies are responsible
1387 * to ensure this.
1388 */
1389 if (use_strategies_nr == 1 ||
1390 /*
1391 * Stash away the local changes so that we can try more than one.
1392 */
1393 save_state(stash))
1394 hashcpy(stash, null_sha1);
1395
1396 for (i = 0; i < use_strategies_nr; i++) {
1397 int ret;
1398 if (i) {
1399 printf(_("Rewinding the tree to pristine...\n"));
1400 restore_state(head_commit->object.sha1, stash);
1401 }
1402 if (use_strategies_nr != 1)
1403 printf(_("Trying merge strategy %s...\n"),
1404 use_strategies[i]->name);
1405 /*
1406 * Remember which strategy left the state in the working
1407 * tree.
1408 */
1409 wt_strategy = use_strategies[i]->name;
1410
1411 ret = try_merge_strategy(use_strategies[i]->name,
1412 common, head_commit, head_arg);
1413 if (!option_commit && !ret) {
1414 merge_was_ok = 1;
1415 /*
1416 * This is necessary here just to avoid writing
1417 * the tree, but later we will *not* exit with
1418 * status code 1 because merge_was_ok is set.
1419 */
1420 ret = 1;
1421 }
1422
1423 if (ret) {
1424 /*
1425 * The backend exits with 1 when conflicts are
1426 * left to be resolved, with 2 when it does not
1427 * handle the given merge at all.
1428 */
1429 if (ret == 1) {
1430 int cnt = evaluate_result();
1431
1432 if (best_cnt <= 0 || cnt <= best_cnt) {
1433 best_strategy = use_strategies[i]->name;
1434 best_cnt = cnt;
1435 }
1436 }
1437 if (merge_was_ok)
1438 break;
1439 else
1440 continue;
1441 }
1442
1443 /* Automerge succeeded. */
1444 write_tree_trivial(result_tree);
1445 automerge_was_ok = 1;
1446 break;
1447 }
1448
1449 /*
1450 * If we have a resulting tree, that means the strategy module
1451 * auto resolved the merge cleanly.
1452 */
1453 if (automerge_was_ok)
1454 return finish_automerge(head_commit, common, result_tree,
1455 wt_strategy);
1456
1457 /*
1458 * Pick the result from the best strategy and have the user fix
1459 * it up.
1460 */
1461 if (!best_strategy) {
1462 restore_state(head_commit->object.sha1, stash);
1463 if (use_strategies_nr > 1)
1464 fprintf(stderr,
1465 _("No merge strategy handled the merge.\n"));
1466 else
1467 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1468 use_strategies[0]->name);
1469 return 2;
1470 } else if (best_strategy == wt_strategy)
1471 ; /* We already have its result in the working tree. */
1472 else {
1473 printf(_("Rewinding the tree to pristine...\n"));
1474 restore_state(head_commit->object.sha1, stash);
1475 printf(_("Using the %s to prepare resolving by hand.\n"),
1476 best_strategy);
1477 try_merge_strategy(best_strategy, common, head_commit, head_arg);
1478 }
1479
1480 if (squash)
1481 finish(head_commit, NULL, NULL);
1482 else
1483 write_merge_state();
1484
1485 if (merge_was_ok) {
1486 fprintf(stderr, _("Automatic merge went well; "
1487 "stopped before committing as requested\n"));
1488 return 0;
1489 } else
1490 return suggest_conflicts(option_renormalize);
1491 }