test patch hunk editing with "commit -p -m"
[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 #include "fmt-merge-msg.h"
30 #include "gpg-interface.h"
31
32 #define DEFAULT_TWOHEAD (1<<0)
33 #define DEFAULT_OCTOPUS (1<<1)
34 #define NO_FAST_FORWARD (1<<2)
35 #define NO_TRIVIAL (1<<3)
36
37 struct strategy {
38 const char *name;
39 unsigned attr;
40 };
41
42 static const char * const builtin_merge_usage[] = {
43 N_("git merge [options] [<commit>...]"),
44 N_("git merge [options] <msg> HEAD <commit>"),
45 N_("git merge --abort"),
46 NULL
47 };
48
49 static int show_diffstat = 1, shortlog_len = -1, squash;
50 static int option_commit = 1;
51 static int option_edit = -1;
52 static int allow_trivial = 1, have_message, verify_signatures;
53 static int overwrite_ignore = 1;
54 static struct strbuf merge_msg = STRBUF_INIT;
55 static struct strategy **use_strategies;
56 static size_t use_strategies_nr, use_strategies_alloc;
57 static const char **xopts;
58 static size_t xopts_nr, xopts_alloc;
59 static const char *branch;
60 static char *branch_mergeoptions;
61 static int option_renormalize;
62 static int verbosity;
63 static int allow_rerere_auto;
64 static int abort_current_merge;
65 static int show_progress = -1;
66 static int default_to_upstream;
67 static const char *sign_commit;
68
69 static struct strategy all_strategy[] = {
70 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
71 { "octopus", DEFAULT_OCTOPUS },
72 { "resolve", 0 },
73 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
74 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
75 };
76
77 static const char *pull_twohead, *pull_octopus;
78
79 enum ff_type {
80 FF_NO,
81 FF_ALLOW,
82 FF_ONLY
83 };
84
85 static enum ff_type fast_forward = FF_ALLOW;
86
87 static int option_parse_message(const struct option *opt,
88 const char *arg, int unset)
89 {
90 struct strbuf *buf = opt->value;
91
92 if (unset)
93 strbuf_setlen(buf, 0);
94 else if (arg) {
95 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
96 have_message = 1;
97 } else
98 return error(_("switch `m' requires a value"));
99 return 0;
100 }
101
102 static struct strategy *get_strategy(const char *name)
103 {
104 int i;
105 struct strategy *ret;
106 static struct cmdnames main_cmds, other_cmds;
107 static int loaded;
108
109 if (!name)
110 return NULL;
111
112 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
113 if (!strcmp(name, all_strategy[i].name))
114 return &all_strategy[i];
115
116 if (!loaded) {
117 struct cmdnames not_strategies;
118 loaded = 1;
119
120 memset(&not_strategies, 0, sizeof(struct cmdnames));
121 load_command_list("git-merge-", &main_cmds, &other_cmds);
122 for (i = 0; i < main_cmds.cnt; i++) {
123 int j, found = 0;
124 struct cmdname *ent = main_cmds.names[i];
125 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
126 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
127 && !all_strategy[j].name[ent->len])
128 found = 1;
129 if (!found)
130 add_cmdname(&not_strategies, ent->name, ent->len);
131 }
132 exclude_cmds(&main_cmds, &not_strategies);
133 }
134 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
135 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
136 fprintf(stderr, _("Available strategies are:"));
137 for (i = 0; i < main_cmds.cnt; i++)
138 fprintf(stderr, " %s", main_cmds.names[i]->name);
139 fprintf(stderr, ".\n");
140 if (other_cmds.cnt) {
141 fprintf(stderr, _("Available custom strategies are:"));
142 for (i = 0; i < other_cmds.cnt; i++)
143 fprintf(stderr, " %s", other_cmds.names[i]->name);
144 fprintf(stderr, ".\n");
145 }
146 exit(1);
147 }
148
149 ret = xcalloc(1, sizeof(struct strategy));
150 ret->name = xstrdup(name);
151 ret->attr = NO_TRIVIAL;
152 return ret;
153 }
154
155 static void append_strategy(struct strategy *s)
156 {
157 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
158 use_strategies[use_strategies_nr++] = s;
159 }
160
161 static int option_parse_strategy(const struct option *opt,
162 const char *name, int unset)
163 {
164 if (unset)
165 return 0;
166
167 append_strategy(get_strategy(name));
168 return 0;
169 }
170
171 static int option_parse_x(const struct option *opt,
172 const char *arg, int unset)
173 {
174 if (unset)
175 return 0;
176
177 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
178 xopts[xopts_nr++] = xstrdup(arg);
179 return 0;
180 }
181
182 static int option_parse_n(const struct option *opt,
183 const char *arg, int unset)
184 {
185 show_diffstat = unset;
186 return 0;
187 }
188
189 static struct option builtin_merge_options[] = {
190 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
191 N_("do not show a diffstat at the end of the merge"),
192 PARSE_OPT_NOARG, option_parse_n },
193 OPT_BOOL(0, "stat", &show_diffstat,
194 N_("show a diffstat at the end of the merge")),
195 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
196 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
197 N_("add (at most <n>) entries from shortlog to merge commit message"),
198 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
199 OPT_BOOL(0, "squash", &squash,
200 N_("create a single commit instead of doing a merge")),
201 OPT_BOOL(0, "commit", &option_commit,
202 N_("perform a commit if the merge succeeds (default)")),
203 OPT_BOOL('e', "edit", &option_edit,
204 N_("edit message before committing")),
205 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
206 { OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
207 N_("abort if fast-forward is not possible"),
208 PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
209 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
210 OPT_BOOL(0, "verify-signatures", &verify_signatures,
211 N_("Verify that the named commit has a valid GPG signature")),
212 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
213 N_("merge strategy to use"), option_parse_strategy),
214 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
215 N_("option for selected merge strategy"), option_parse_x),
216 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
217 N_("merge commit message (for a non-fast-forward merge)"),
218 option_parse_message),
219 OPT__VERBOSITY(&verbosity),
220 OPT_BOOL(0, "abort", &abort_current_merge,
221 N_("abort the current in-progress merge")),
222 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
223 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key id"),
224 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
225 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
226 OPT_END()
227 };
228
229 /* Cleans up metadata that is uninteresting after a succeeded merge. */
230 static void drop_save(void)
231 {
232 unlink(git_path("MERGE_HEAD"));
233 unlink(git_path("MERGE_MSG"));
234 unlink(git_path("MERGE_MODE"));
235 }
236
237 static int save_state(unsigned char *stash)
238 {
239 int len;
240 struct child_process cp;
241 struct strbuf buffer = STRBUF_INIT;
242 const char *argv[] = {"stash", "create", NULL};
243
244 memset(&cp, 0, sizeof(cp));
245 cp.argv = argv;
246 cp.out = -1;
247 cp.git_cmd = 1;
248
249 if (start_command(&cp))
250 die(_("could not run stash."));
251 len = strbuf_read(&buffer, cp.out, 1024);
252 close(cp.out);
253
254 if (finish_command(&cp) || len < 0)
255 die(_("stash failed"));
256 else if (!len) /* no changes */
257 return -1;
258 strbuf_setlen(&buffer, buffer.len-1);
259 if (get_sha1(buffer.buf, stash))
260 die(_("not a valid object: %s"), buffer.buf);
261 return 0;
262 }
263
264 static void read_empty(unsigned const char *sha1, int verbose)
265 {
266 int i = 0;
267 const char *args[7];
268
269 args[i++] = "read-tree";
270 if (verbose)
271 args[i++] = "-v";
272 args[i++] = "-m";
273 args[i++] = "-u";
274 args[i++] = EMPTY_TREE_SHA1_HEX;
275 args[i++] = sha1_to_hex(sha1);
276 args[i] = NULL;
277
278 if (run_command_v_opt(args, RUN_GIT_CMD))
279 die(_("read-tree failed"));
280 }
281
282 static void reset_hard(unsigned const char *sha1, int verbose)
283 {
284 int i = 0;
285 const char *args[6];
286
287 args[i++] = "read-tree";
288 if (verbose)
289 args[i++] = "-v";
290 args[i++] = "--reset";
291 args[i++] = "-u";
292 args[i++] = sha1_to_hex(sha1);
293 args[i] = NULL;
294
295 if (run_command_v_opt(args, RUN_GIT_CMD))
296 die(_("read-tree failed"));
297 }
298
299 static void restore_state(const unsigned char *head,
300 const unsigned char *stash)
301 {
302 struct strbuf sb = STRBUF_INIT;
303 const char *args[] = { "stash", "apply", NULL, NULL };
304
305 if (is_null_sha1(stash))
306 return;
307
308 reset_hard(head, 1);
309
310 args[2] = sha1_to_hex(stash);
311
312 /*
313 * It is OK to ignore error here, for example when there was
314 * nothing to restore.
315 */
316 run_command_v_opt(args, RUN_GIT_CMD);
317
318 strbuf_release(&sb);
319 refresh_cache(REFRESH_QUIET);
320 }
321
322 /* This is called when no merge was necessary. */
323 static void finish_up_to_date(const char *msg)
324 {
325 if (verbosity >= 0)
326 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
327 drop_save();
328 }
329
330 static void squash_message(struct commit *commit, struct commit_list *remoteheads)
331 {
332 struct rev_info rev;
333 struct strbuf out = STRBUF_INIT;
334 struct commit_list *j;
335 const char *filename;
336 int fd;
337 struct pretty_print_context ctx = {0};
338
339 printf(_("Squash commit -- not updating HEAD\n"));
340 filename = git_path("SQUASH_MSG");
341 fd = open(filename, O_WRONLY | O_CREAT, 0666);
342 if (fd < 0)
343 die_errno(_("Could not write to '%s'"), filename);
344
345 init_revisions(&rev, NULL);
346 rev.ignore_merges = 1;
347 rev.commit_format = CMIT_FMT_MEDIUM;
348
349 commit->object.flags |= UNINTERESTING;
350 add_pending_object(&rev, &commit->object, NULL);
351
352 for (j = remoteheads; j; j = j->next)
353 add_pending_object(&rev, &j->item->object, NULL);
354
355 setup_revisions(0, NULL, &rev, NULL);
356 if (prepare_revision_walk(&rev))
357 die(_("revision walk setup failed"));
358
359 ctx.abbrev = rev.abbrev;
360 ctx.date_mode = rev.date_mode;
361 ctx.fmt = rev.commit_format;
362
363 strbuf_addstr(&out, "Squashed commit of the following:\n");
364 while ((commit = get_revision(&rev)) != NULL) {
365 strbuf_addch(&out, '\n');
366 strbuf_addf(&out, "commit %s\n",
367 sha1_to_hex(commit->object.sha1));
368 pretty_print_commit(&ctx, commit, &out);
369 }
370 if (write_in_full(fd, out.buf, out.len) != out.len)
371 die_errno(_("Writing SQUASH_MSG"));
372 if (close(fd))
373 die_errno(_("Finishing SQUASH_MSG"));
374 strbuf_release(&out);
375 }
376
377 static void finish(struct commit *head_commit,
378 struct commit_list *remoteheads,
379 const unsigned char *new_head, const char *msg)
380 {
381 struct strbuf reflog_message = STRBUF_INIT;
382 const unsigned char *head = head_commit->object.sha1;
383
384 if (!msg)
385 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
386 else {
387 if (verbosity >= 0)
388 printf("%s\n", msg);
389 strbuf_addf(&reflog_message, "%s: %s",
390 getenv("GIT_REFLOG_ACTION"), msg);
391 }
392 if (squash) {
393 squash_message(head_commit, remoteheads);
394 } else {
395 if (verbosity >= 0 && !merge_msg.len)
396 printf(_("No merge message -- not updating HEAD\n"));
397 else {
398 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
399 update_ref(reflog_message.buf, "HEAD",
400 new_head, head, 0,
401 DIE_ON_ERR);
402 /*
403 * We ignore errors in 'gc --auto', since the
404 * user should see them.
405 */
406 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
407 }
408 }
409 if (new_head && show_diffstat) {
410 struct diff_options opts;
411 diff_setup(&opts);
412 opts.stat_width = -1; /* use full terminal width */
413 opts.stat_graph_width = -1; /* respect statGraphWidth config */
414 opts.output_format |=
415 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
416 opts.detect_rename = DIFF_DETECT_RENAME;
417 diff_setup_done(&opts);
418 diff_tree_sha1(head, new_head, "", &opts);
419 diffcore_std(&opts);
420 diff_flush(&opts);
421 }
422
423 /* Run a post-merge hook */
424 run_hook(NULL, "post-merge", squash ? "1" : "0", NULL);
425
426 strbuf_release(&reflog_message);
427 }
428
429 /* Get the name for the merge commit's message. */
430 static void merge_name(const char *remote, struct strbuf *msg)
431 {
432 struct commit *remote_head;
433 unsigned char branch_head[20];
434 struct strbuf buf = STRBUF_INIT;
435 struct strbuf bname = STRBUF_INIT;
436 const char *ptr;
437 char *found_ref;
438 int len, early;
439
440 strbuf_branchname(&bname, remote);
441 remote = bname.buf;
442
443 memset(branch_head, 0, sizeof(branch_head));
444 remote_head = get_merge_parent(remote);
445 if (!remote_head)
446 die(_("'%s' does not point to a commit"), remote);
447
448 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
449 if (starts_with(found_ref, "refs/heads/")) {
450 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
451 sha1_to_hex(branch_head), remote);
452 goto cleanup;
453 }
454 if (starts_with(found_ref, "refs/tags/")) {
455 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
456 sha1_to_hex(branch_head), remote);
457 goto cleanup;
458 }
459 if (starts_with(found_ref, "refs/remotes/")) {
460 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
461 sha1_to_hex(branch_head), remote);
462 goto cleanup;
463 }
464 }
465
466 /* See if remote matches <name>^^^.. or <name>~<number> */
467 for (len = 0, ptr = remote + strlen(remote);
468 remote < ptr && ptr[-1] == '^';
469 ptr--)
470 len++;
471 if (len)
472 early = 1;
473 else {
474 early = 0;
475 ptr = strrchr(remote, '~');
476 if (ptr) {
477 int seen_nonzero = 0;
478
479 len++; /* count ~ */
480 while (*++ptr && isdigit(*ptr)) {
481 seen_nonzero |= (*ptr != '0');
482 len++;
483 }
484 if (*ptr)
485 len = 0; /* not ...~<number> */
486 else if (seen_nonzero)
487 early = 1;
488 else if (len == 1)
489 early = 1; /* "name~" is "name~1"! */
490 }
491 }
492 if (len) {
493 struct strbuf truname = STRBUF_INIT;
494 strbuf_addstr(&truname, "refs/heads/");
495 strbuf_addstr(&truname, remote);
496 strbuf_setlen(&truname, truname.len - len);
497 if (ref_exists(truname.buf)) {
498 strbuf_addf(msg,
499 "%s\t\tbranch '%s'%s of .\n",
500 sha1_to_hex(remote_head->object.sha1),
501 truname.buf + 11,
502 (early ? " (early part)" : ""));
503 strbuf_release(&truname);
504 goto cleanup;
505 }
506 }
507
508 if (!strcmp(remote, "FETCH_HEAD") &&
509 !access(git_path("FETCH_HEAD"), R_OK)) {
510 const char *filename;
511 FILE *fp;
512 struct strbuf line = STRBUF_INIT;
513 char *ptr;
514
515 filename = git_path("FETCH_HEAD");
516 fp = fopen(filename, "r");
517 if (!fp)
518 die_errno(_("could not open '%s' for reading"),
519 filename);
520 strbuf_getline(&line, fp, '\n');
521 fclose(fp);
522 ptr = strstr(line.buf, "\tnot-for-merge\t");
523 if (ptr)
524 strbuf_remove(&line, ptr-line.buf+1, 13);
525 strbuf_addbuf(msg, &line);
526 strbuf_release(&line);
527 goto cleanup;
528 }
529
530 if (remote_head->util) {
531 struct merge_remote_desc *desc;
532 desc = merge_remote_util(remote_head);
533 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
534 strbuf_addf(msg, "%s\t\t%s '%s'\n",
535 sha1_to_hex(desc->obj->sha1),
536 typename(desc->obj->type),
537 remote);
538 goto cleanup;
539 }
540 }
541
542 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
543 sha1_to_hex(remote_head->object.sha1), remote);
544 cleanup:
545 strbuf_release(&buf);
546 strbuf_release(&bname);
547 }
548
549 static void parse_branch_merge_options(char *bmo)
550 {
551 const char **argv;
552 int argc;
553
554 if (!bmo)
555 return;
556 argc = split_cmdline(bmo, &argv);
557 if (argc < 0)
558 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
559 split_cmdline_strerror(argc));
560 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
561 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
562 argc++;
563 argv[0] = "branch.*.mergeoptions";
564 parse_options(argc, argv, NULL, builtin_merge_options,
565 builtin_merge_usage, 0);
566 free(argv);
567 }
568
569 static int git_merge_config(const char *k, const char *v, void *cb)
570 {
571 int status;
572
573 if (branch && starts_with(k, "branch.") &&
574 starts_with(k + 7, branch) &&
575 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
576 free(branch_mergeoptions);
577 branch_mergeoptions = xstrdup(v);
578 return 0;
579 }
580
581 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
582 show_diffstat = git_config_bool(k, v);
583 else if (!strcmp(k, "pull.twohead"))
584 return git_config_string(&pull_twohead, k, v);
585 else if (!strcmp(k, "pull.octopus"))
586 return git_config_string(&pull_octopus, k, v);
587 else if (!strcmp(k, "merge.renormalize"))
588 option_renormalize = git_config_bool(k, v);
589 else if (!strcmp(k, "merge.ff")) {
590 int boolval = git_config_maybe_bool(k, v);
591 if (0 <= boolval) {
592 fast_forward = boolval ? FF_ALLOW : FF_NO;
593 } else if (v && !strcmp(v, "only")) {
594 fast_forward = FF_ONLY;
595 } /* do not barf on values from future versions of git */
596 return 0;
597 } else if (!strcmp(k, "merge.defaulttoupstream")) {
598 default_to_upstream = git_config_bool(k, v);
599 return 0;
600 }
601
602 status = fmt_merge_msg_config(k, v, cb);
603 if (status)
604 return status;
605 status = git_gpg_config(k, v, NULL);
606 if (status)
607 return status;
608 return git_diff_ui_config(k, v, cb);
609 }
610
611 static int read_tree_trivial(unsigned char *common, unsigned char *head,
612 unsigned char *one)
613 {
614 int i, nr_trees = 0;
615 struct tree *trees[MAX_UNPACK_TREES];
616 struct tree_desc t[MAX_UNPACK_TREES];
617 struct unpack_trees_options opts;
618
619 memset(&opts, 0, sizeof(opts));
620 opts.head_idx = 2;
621 opts.src_index = &the_index;
622 opts.dst_index = &the_index;
623 opts.update = 1;
624 opts.verbose_update = 1;
625 opts.trivial_merges_only = 1;
626 opts.merge = 1;
627 trees[nr_trees] = parse_tree_indirect(common);
628 if (!trees[nr_trees++])
629 return -1;
630 trees[nr_trees] = parse_tree_indirect(head);
631 if (!trees[nr_trees++])
632 return -1;
633 trees[nr_trees] = parse_tree_indirect(one);
634 if (!trees[nr_trees++])
635 return -1;
636 opts.fn = threeway_merge;
637 cache_tree_free(&active_cache_tree);
638 for (i = 0; i < nr_trees; i++) {
639 parse_tree(trees[i]);
640 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
641 }
642 if (unpack_trees(nr_trees, t, &opts))
643 return -1;
644 return 0;
645 }
646
647 static void write_tree_trivial(unsigned char *sha1)
648 {
649 if (write_cache_as_tree(sha1, 0, NULL))
650 die(_("git write-tree failed to write a tree"));
651 }
652
653 static int try_merge_strategy(const char *strategy, struct commit_list *common,
654 struct commit_list *remoteheads,
655 struct commit *head, const char *head_arg)
656 {
657 int index_fd;
658 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
659
660 index_fd = hold_locked_index(lock, 1);
661 refresh_cache(REFRESH_QUIET);
662 if (active_cache_changed &&
663 (write_cache(index_fd, active_cache, active_nr) ||
664 commit_locked_index(lock)))
665 return error(_("Unable to write index."));
666 rollback_lock_file(lock);
667
668 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
669 int clean, x;
670 struct commit *result;
671 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
672 int index_fd;
673 struct commit_list *reversed = NULL;
674 struct merge_options o;
675 struct commit_list *j;
676
677 if (remoteheads->next) {
678 error(_("Not handling anything other than two heads merge."));
679 return 2;
680 }
681
682 init_merge_options(&o);
683 if (!strcmp(strategy, "subtree"))
684 o.subtree_shift = "";
685
686 o.renormalize = option_renormalize;
687 o.show_rename_progress =
688 show_progress == -1 ? isatty(2) : show_progress;
689
690 for (x = 0; x < xopts_nr; x++)
691 if (parse_merge_opt(&o, xopts[x]))
692 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
693
694 o.branch1 = head_arg;
695 o.branch2 = merge_remote_util(remoteheads->item)->name;
696
697 for (j = common; j; j = j->next)
698 commit_list_insert(j->item, &reversed);
699
700 index_fd = hold_locked_index(lock, 1);
701 clean = merge_recursive(&o, head,
702 remoteheads->item, reversed, &result);
703 if (active_cache_changed &&
704 (write_cache(index_fd, active_cache, active_nr) ||
705 commit_locked_index(lock)))
706 die (_("unable to write %s"), get_index_file());
707 rollback_lock_file(lock);
708 return clean ? 0 : 1;
709 } else {
710 return try_merge_command(strategy, xopts_nr, xopts,
711 common, head_arg, remoteheads);
712 }
713 }
714
715 static void count_diff_files(struct diff_queue_struct *q,
716 struct diff_options *opt, void *data)
717 {
718 int *count = data;
719
720 (*count) += q->nr;
721 }
722
723 static int count_unmerged_entries(void)
724 {
725 int i, ret = 0;
726
727 for (i = 0; i < active_nr; i++)
728 if (ce_stage(active_cache[i]))
729 ret++;
730
731 return ret;
732 }
733
734 static void split_merge_strategies(const char *string, struct strategy **list,
735 int *nr, int *alloc)
736 {
737 char *p, *q, *buf;
738
739 if (!string)
740 return;
741
742 buf = xstrdup(string);
743 q = buf;
744 for (;;) {
745 p = strchr(q, ' ');
746 if (!p) {
747 ALLOC_GROW(*list, *nr + 1, *alloc);
748 (*list)[(*nr)++].name = xstrdup(q);
749 free(buf);
750 return;
751 } else {
752 *p = '\0';
753 ALLOC_GROW(*list, *nr + 1, *alloc);
754 (*list)[(*nr)++].name = xstrdup(q);
755 q = ++p;
756 }
757 }
758 }
759
760 static void add_strategies(const char *string, unsigned attr)
761 {
762 struct strategy *list = NULL;
763 int list_alloc = 0, list_nr = 0, i;
764
765 memset(&list, 0, sizeof(list));
766 split_merge_strategies(string, &list, &list_nr, &list_alloc);
767 if (list) {
768 for (i = 0; i < list_nr; i++)
769 append_strategy(get_strategy(list[i].name));
770 return;
771 }
772 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
773 if (all_strategy[i].attr & attr)
774 append_strategy(&all_strategy[i]);
775
776 }
777
778 static void write_merge_msg(struct strbuf *msg)
779 {
780 const char *filename = git_path("MERGE_MSG");
781 int fd = open(filename, O_WRONLY | O_CREAT, 0666);
782 if (fd < 0)
783 die_errno(_("Could not open '%s' for writing"),
784 filename);
785 if (write_in_full(fd, msg->buf, msg->len) != msg->len)
786 die_errno(_("Could not write to '%s'"), filename);
787 close(fd);
788 }
789
790 static void read_merge_msg(struct strbuf *msg)
791 {
792 const char *filename = git_path("MERGE_MSG");
793 strbuf_reset(msg);
794 if (strbuf_read_file(msg, filename, 0) < 0)
795 die_errno(_("Could not read from '%s'"), filename);
796 }
797
798 static void write_merge_state(struct commit_list *);
799 static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
800 {
801 if (err_msg)
802 error("%s", err_msg);
803 fprintf(stderr,
804 _("Not committing merge; use 'git commit' to complete the merge.\n"));
805 write_merge_state(remoteheads);
806 exit(1);
807 }
808
809 static const char merge_editor_comment[] =
810 N_("Please enter a commit message to explain why this merge is necessary,\n"
811 "especially if it merges an updated upstream into a topic branch.\n"
812 "\n"
813 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
814 "the commit.\n");
815
816 static void prepare_to_commit(struct commit_list *remoteheads)
817 {
818 struct strbuf msg = STRBUF_INIT;
819 strbuf_addbuf(&msg, &merge_msg);
820 strbuf_addch(&msg, '\n');
821 if (0 < option_edit)
822 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
823 write_merge_msg(&msg);
824 if (run_hook(get_index_file(), "prepare-commit-msg",
825 git_path("MERGE_MSG"), "merge", NULL, NULL))
826 abort_commit(remoteheads, NULL);
827 if (0 < option_edit) {
828 if (launch_editor(git_path("MERGE_MSG"), NULL, NULL))
829 abort_commit(remoteheads, NULL);
830 }
831 read_merge_msg(&msg);
832 stripspace(&msg, 0 < option_edit);
833 if (!msg.len)
834 abort_commit(remoteheads, _("Empty commit message."));
835 strbuf_release(&merge_msg);
836 strbuf_addbuf(&merge_msg, &msg);
837 strbuf_release(&msg);
838 }
839
840 static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
841 {
842 unsigned char result_tree[20], result_commit[20];
843 struct commit_list *parent = xmalloc(sizeof(*parent));
844
845 write_tree_trivial(result_tree);
846 printf(_("Wonderful.\n"));
847 parent->item = head;
848 parent->next = xmalloc(sizeof(*parent->next));
849 parent->next->item = remoteheads->item;
850 parent->next->next = NULL;
851 prepare_to_commit(remoteheads);
852 if (commit_tree(&merge_msg, result_tree, parent, result_commit, NULL,
853 sign_commit))
854 die(_("failed to write commit object"));
855 finish(head, remoteheads, result_commit, "In-index merge");
856 drop_save();
857 return 0;
858 }
859
860 static int finish_automerge(struct commit *head,
861 int head_subsumed,
862 struct commit_list *common,
863 struct commit_list *remoteheads,
864 unsigned char *result_tree,
865 const char *wt_strategy)
866 {
867 struct commit_list *parents = NULL;
868 struct strbuf buf = STRBUF_INIT;
869 unsigned char result_commit[20];
870
871 free_commit_list(common);
872 parents = remoteheads;
873 if (!head_subsumed || fast_forward == FF_NO)
874 commit_list_insert(head, &parents);
875 strbuf_addch(&merge_msg, '\n');
876 prepare_to_commit(remoteheads);
877 if (commit_tree(&merge_msg, result_tree, parents, result_commit,
878 NULL, sign_commit))
879 die(_("failed to write commit object"));
880 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
881 finish(head, remoteheads, result_commit, buf.buf);
882 strbuf_release(&buf);
883 drop_save();
884 return 0;
885 }
886
887 static int suggest_conflicts(int renormalizing)
888 {
889 const char *filename;
890 FILE *fp;
891 int pos;
892
893 filename = git_path("MERGE_MSG");
894 fp = fopen(filename, "a");
895 if (!fp)
896 die_errno(_("Could not open '%s' for writing"), filename);
897 fprintf(fp, "\nConflicts:\n");
898 for (pos = 0; pos < active_nr; pos++) {
899 const struct cache_entry *ce = active_cache[pos];
900
901 if (ce_stage(ce)) {
902 fprintf(fp, "\t%s\n", ce->name);
903 while (pos + 1 < active_nr &&
904 !strcmp(ce->name,
905 active_cache[pos + 1]->name))
906 pos++;
907 }
908 }
909 fclose(fp);
910 rerere(allow_rerere_auto);
911 printf(_("Automatic merge failed; "
912 "fix conflicts and then commit the result.\n"));
913 return 1;
914 }
915
916 static struct commit *is_old_style_invocation(int argc, const char **argv,
917 const unsigned char *head)
918 {
919 struct commit *second_token = NULL;
920 if (argc > 2) {
921 unsigned char second_sha1[20];
922
923 if (get_sha1(argv[1], second_sha1))
924 return NULL;
925 second_token = lookup_commit_reference_gently(second_sha1, 0);
926 if (!second_token)
927 die(_("'%s' is not a commit"), argv[1]);
928 if (hashcmp(second_token->object.sha1, head))
929 return NULL;
930 }
931 return second_token;
932 }
933
934 static int evaluate_result(void)
935 {
936 int cnt = 0;
937 struct rev_info rev;
938
939 /* Check how many files differ. */
940 init_revisions(&rev, "");
941 setup_revisions(0, NULL, &rev, NULL);
942 rev.diffopt.output_format |=
943 DIFF_FORMAT_CALLBACK;
944 rev.diffopt.format_callback = count_diff_files;
945 rev.diffopt.format_callback_data = &cnt;
946 run_diff_files(&rev, 0);
947
948 /*
949 * Check how many unmerged entries are
950 * there.
951 */
952 cnt += count_unmerged_entries();
953
954 return cnt;
955 }
956
957 /*
958 * Pretend as if the user told us to merge with the remote-tracking
959 * branch we have for the upstream of the current branch
960 */
961 static int setup_with_upstream(const char ***argv)
962 {
963 struct branch *branch = branch_get(NULL);
964 int i;
965 const char **args;
966
967 if (!branch)
968 die(_("No current branch."));
969 if (!branch->remote)
970 die(_("No remote for the current branch."));
971 if (!branch->merge_nr)
972 die(_("No default upstream defined for the current branch."));
973
974 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
975 for (i = 0; i < branch->merge_nr; i++) {
976 if (!branch->merge[i]->dst)
977 die(_("No remote-tracking branch for %s from %s"),
978 branch->merge[i]->src, branch->remote_name);
979 args[i] = branch->merge[i]->dst;
980 }
981 args[i] = NULL;
982 *argv = args;
983 return i;
984 }
985
986 static void write_merge_state(struct commit_list *remoteheads)
987 {
988 const char *filename;
989 int fd;
990 struct commit_list *j;
991 struct strbuf buf = STRBUF_INIT;
992
993 for (j = remoteheads; j; j = j->next) {
994 unsigned const char *sha1;
995 struct commit *c = j->item;
996 if (c->util && merge_remote_util(c)->obj) {
997 sha1 = merge_remote_util(c)->obj->sha1;
998 } else {
999 sha1 = c->object.sha1;
1000 }
1001 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
1002 }
1003 filename = git_path("MERGE_HEAD");
1004 fd = open(filename, O_WRONLY | O_CREAT, 0666);
1005 if (fd < 0)
1006 die_errno(_("Could not open '%s' for writing"), filename);
1007 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1008 die_errno(_("Could not write to '%s'"), filename);
1009 close(fd);
1010 strbuf_addch(&merge_msg, '\n');
1011 write_merge_msg(&merge_msg);
1012
1013 filename = git_path("MERGE_MODE");
1014 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
1015 if (fd < 0)
1016 die_errno(_("Could not open '%s' for writing"), filename);
1017 strbuf_reset(&buf);
1018 if (fast_forward == FF_NO)
1019 strbuf_addf(&buf, "no-ff");
1020 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1021 die_errno(_("Could not write to '%s'"), filename);
1022 close(fd);
1023 }
1024
1025 static int default_edit_option(void)
1026 {
1027 static const char name[] = "GIT_MERGE_AUTOEDIT";
1028 const char *e = getenv(name);
1029 struct stat st_stdin, st_stdout;
1030
1031 if (have_message)
1032 /* an explicit -m msg without --[no-]edit */
1033 return 0;
1034
1035 if (e) {
1036 int v = git_config_maybe_bool(name, e);
1037 if (v < 0)
1038 die("Bad value '%s' in environment '%s'", e, name);
1039 return v;
1040 }
1041
1042 /* Use editor if stdin and stdout are the same and is a tty */
1043 return (!fstat(0, &st_stdin) &&
1044 !fstat(1, &st_stdout) &&
1045 isatty(0) && isatty(1) &&
1046 st_stdin.st_dev == st_stdout.st_dev &&
1047 st_stdin.st_ino == st_stdout.st_ino &&
1048 st_stdin.st_mode == st_stdout.st_mode);
1049 }
1050
1051 static struct commit_list *collect_parents(struct commit *head_commit,
1052 int *head_subsumed,
1053 int argc, const char **argv)
1054 {
1055 int i;
1056 struct commit_list *remoteheads = NULL, *parents, *next;
1057 struct commit_list **remotes = &remoteheads;
1058
1059 if (head_commit)
1060 remotes = &commit_list_insert(head_commit, remotes)->next;
1061 for (i = 0; i < argc; i++) {
1062 struct commit *commit = get_merge_parent(argv[i]);
1063 if (!commit)
1064 help_unknown_ref(argv[i], "merge",
1065 "not something we can merge");
1066 remotes = &commit_list_insert(commit, remotes)->next;
1067 }
1068 *remotes = NULL;
1069
1070 parents = reduce_heads(remoteheads);
1071
1072 *head_subsumed = 1; /* we will flip this to 0 when we find it */
1073 for (remoteheads = NULL, remotes = &remoteheads;
1074 parents;
1075 parents = next) {
1076 struct commit *commit = parents->item;
1077 next = parents->next;
1078 if (commit == head_commit)
1079 *head_subsumed = 0;
1080 else
1081 remotes = &commit_list_insert(commit, remotes)->next;
1082 }
1083 return remoteheads;
1084 }
1085
1086 int cmd_merge(int argc, const char **argv, const char *prefix)
1087 {
1088 unsigned char result_tree[20];
1089 unsigned char stash[20];
1090 unsigned char head_sha1[20];
1091 struct commit *head_commit;
1092 struct strbuf buf = STRBUF_INIT;
1093 const char *head_arg;
1094 int flag, i, ret = 0, head_subsumed;
1095 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1096 struct commit_list *common = NULL;
1097 const char *best_strategy = NULL, *wt_strategy = NULL;
1098 struct commit_list *remoteheads, *p;
1099 void *branch_to_free;
1100
1101 if (argc == 2 && !strcmp(argv[1], "-h"))
1102 usage_with_options(builtin_merge_usage, builtin_merge_options);
1103
1104 /*
1105 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1106 * current branch.
1107 */
1108 branch = branch_to_free = resolve_refdup("HEAD", head_sha1, 0, &flag);
1109 if (branch && starts_with(branch, "refs/heads/"))
1110 branch += 11;
1111 if (!branch || is_null_sha1(head_sha1))
1112 head_commit = NULL;
1113 else
1114 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1115
1116 git_config(git_merge_config, NULL);
1117
1118 if (branch_mergeoptions)
1119 parse_branch_merge_options(branch_mergeoptions);
1120 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1121 builtin_merge_usage, 0);
1122 if (shortlog_len < 0)
1123 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1124
1125 if (verbosity < 0 && show_progress == -1)
1126 show_progress = 0;
1127
1128 if (abort_current_merge) {
1129 int nargc = 2;
1130 const char *nargv[] = {"reset", "--merge", NULL};
1131
1132 if (!file_exists(git_path("MERGE_HEAD")))
1133 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1134
1135 /* Invoke 'git reset --merge' */
1136 ret = cmd_reset(nargc, nargv, prefix);
1137 goto done;
1138 }
1139
1140 if (read_cache_unmerged())
1141 die_resolve_conflict("merge");
1142
1143 if (file_exists(git_path("MERGE_HEAD"))) {
1144 /*
1145 * There is no unmerged entry, don't advise 'git
1146 * add/rm <file>', just 'git commit'.
1147 */
1148 if (advice_resolve_conflict)
1149 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1150 "Please, commit your changes before you can merge."));
1151 else
1152 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1153 }
1154 if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
1155 if (advice_resolve_conflict)
1156 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1157 "Please, commit your changes before you can merge."));
1158 else
1159 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1160 }
1161 resolve_undo_clear();
1162
1163 if (verbosity < 0)
1164 show_diffstat = 0;
1165
1166 if (squash) {
1167 if (fast_forward == FF_NO)
1168 die(_("You cannot combine --squash with --no-ff."));
1169 option_commit = 0;
1170 }
1171
1172 if (!abort_current_merge) {
1173 if (!argc) {
1174 if (default_to_upstream)
1175 argc = setup_with_upstream(&argv);
1176 else
1177 die(_("No commit specified and merge.defaultToUpstream not set."));
1178 } else if (argc == 1 && !strcmp(argv[0], "-"))
1179 argv[0] = "@{-1}";
1180 }
1181 if (!argc)
1182 usage_with_options(builtin_merge_usage,
1183 builtin_merge_options);
1184
1185 /*
1186 * This could be traditional "merge <msg> HEAD <commit>..." and
1187 * the way we can tell it is to see if the second token is HEAD,
1188 * but some people might have misused the interface and used a
1189 * commit-ish that is the same as HEAD there instead.
1190 * Traditional format never would have "-m" so it is an
1191 * additional safety measure to check for it.
1192 */
1193
1194 if (!have_message && head_commit &&
1195 is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
1196 strbuf_addstr(&merge_msg, argv[0]);
1197 head_arg = argv[1];
1198 argv += 2;
1199 argc -= 2;
1200 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1201 } else if (!head_commit) {
1202 struct commit *remote_head;
1203 /*
1204 * If the merged head is a valid one there is no reason
1205 * to forbid "git merge" into a branch yet to be born.
1206 * We do the same for "git pull".
1207 */
1208 if (argc != 1)
1209 die(_("Can merge only exactly one commit into "
1210 "empty head"));
1211 if (squash)
1212 die(_("Squash commit into empty head not supported yet"));
1213 if (fast_forward == FF_NO)
1214 die(_("Non-fast-forward commit does not make sense into "
1215 "an empty head"));
1216 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1217 remote_head = remoteheads->item;
1218 if (!remote_head)
1219 die(_("%s - not something we can merge"), argv[0]);
1220 read_empty(remote_head->object.sha1, 0);
1221 update_ref("initial pull", "HEAD", remote_head->object.sha1,
1222 NULL, 0, DIE_ON_ERR);
1223 goto done;
1224 } else {
1225 struct strbuf merge_names = STRBUF_INIT;
1226
1227 /* We are invoked directly as the first-class UI. */
1228 head_arg = "HEAD";
1229
1230 /*
1231 * All the rest are the commits being merged; prepare
1232 * the standard merge summary message to be appended
1233 * to the given message.
1234 */
1235 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1236 for (p = remoteheads; p; p = p->next)
1237 merge_name(merge_remote_util(p->item)->name, &merge_names);
1238
1239 if (!have_message || shortlog_len) {
1240 struct fmt_merge_msg_opts opts;
1241 memset(&opts, 0, sizeof(opts));
1242 opts.add_title = !have_message;
1243 opts.shortlog_len = shortlog_len;
1244 opts.credit_people = (0 < option_edit);
1245
1246 fmt_merge_msg(&merge_names, &merge_msg, &opts);
1247 if (merge_msg.len)
1248 strbuf_setlen(&merge_msg, merge_msg.len - 1);
1249 }
1250 }
1251
1252 if (!head_commit || !argc)
1253 usage_with_options(builtin_merge_usage,
1254 builtin_merge_options);
1255
1256 if (verify_signatures) {
1257 for (p = remoteheads; p; p = p->next) {
1258 struct commit *commit = p->item;
1259 char hex[41];
1260 struct signature_check signature_check;
1261 memset(&signature_check, 0, sizeof(signature_check));
1262
1263 check_commit_signature(commit, &signature_check);
1264
1265 strcpy(hex, find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
1266 switch (signature_check.result) {
1267 case 'G':
1268 break;
1269 case 'U':
1270 die(_("Commit %s has an untrusted GPG signature, "
1271 "allegedly by %s."), hex, signature_check.signer);
1272 case 'B':
1273 die(_("Commit %s has a bad GPG signature "
1274 "allegedly by %s."), hex, signature_check.signer);
1275 default: /* 'N' */
1276 die(_("Commit %s does not have a GPG signature."), hex);
1277 }
1278 if (verbosity >= 0 && signature_check.result == 'G')
1279 printf(_("Commit %s has a good GPG signature by %s\n"),
1280 hex, signature_check.signer);
1281
1282 free(signature_check.gpg_output);
1283 free(signature_check.gpg_status);
1284 free(signature_check.signer);
1285 free(signature_check.key);
1286 }
1287 }
1288
1289 strbuf_addstr(&buf, "merge");
1290 for (p = remoteheads; p; p = p->next)
1291 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1292 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1293 strbuf_reset(&buf);
1294
1295 for (p = remoteheads; p; p = p->next) {
1296 struct commit *commit = p->item;
1297 strbuf_addf(&buf, "GITHEAD_%s",
1298 sha1_to_hex(commit->object.sha1));
1299 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1300 strbuf_reset(&buf);
1301 if (fast_forward != FF_ONLY &&
1302 merge_remote_util(commit) &&
1303 merge_remote_util(commit)->obj &&
1304 merge_remote_util(commit)->obj->type == OBJ_TAG)
1305 fast_forward = FF_NO;
1306 }
1307
1308 if (option_edit < 0)
1309 option_edit = default_edit_option();
1310
1311 if (!use_strategies) {
1312 if (!remoteheads)
1313 ; /* already up-to-date */
1314 else if (!remoteheads->next)
1315 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1316 else
1317 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1318 }
1319
1320 for (i = 0; i < use_strategies_nr; i++) {
1321 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1322 fast_forward = FF_NO;
1323 if (use_strategies[i]->attr & NO_TRIVIAL)
1324 allow_trivial = 0;
1325 }
1326
1327 if (!remoteheads)
1328 ; /* already up-to-date */
1329 else if (!remoteheads->next)
1330 common = get_merge_bases(head_commit, remoteheads->item, 1);
1331 else {
1332 struct commit_list *list = remoteheads;
1333 commit_list_insert(head_commit, &list);
1334 common = get_octopus_merge_bases(list);
1335 free(list);
1336 }
1337
1338 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
1339 NULL, 0, DIE_ON_ERR);
1340
1341 if (remoteheads && !common)
1342 ; /* No common ancestors found. We need a real merge. */
1343 else if (!remoteheads ||
1344 (!remoteheads->next && !common->next &&
1345 common->item == remoteheads->item)) {
1346 /*
1347 * If head can reach all the merge then we are up to date.
1348 * but first the most common case of merging one remote.
1349 */
1350 finish_up_to_date("Already up-to-date.");
1351 goto done;
1352 } else if (fast_forward != FF_NO && !remoteheads->next &&
1353 !common->next &&
1354 !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
1355 /* Again the most common case of merging one remote. */
1356 struct strbuf msg = STRBUF_INIT;
1357 struct commit *commit;
1358 char hex[41];
1359
1360 strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
1361
1362 if (verbosity >= 0)
1363 printf(_("Updating %s..%s\n"),
1364 hex,
1365 find_unique_abbrev(remoteheads->item->object.sha1,
1366 DEFAULT_ABBREV));
1367 strbuf_addstr(&msg, "Fast-forward");
1368 if (have_message)
1369 strbuf_addstr(&msg,
1370 " (no commit created; -m option ignored)");
1371 commit = remoteheads->item;
1372 if (!commit) {
1373 ret = 1;
1374 goto done;
1375 }
1376
1377 if (checkout_fast_forward(head_commit->object.sha1,
1378 commit->object.sha1,
1379 overwrite_ignore)) {
1380 ret = 1;
1381 goto done;
1382 }
1383
1384 finish(head_commit, remoteheads, commit->object.sha1, msg.buf);
1385 drop_save();
1386 goto done;
1387 } else if (!remoteheads->next && common->next)
1388 ;
1389 /*
1390 * We are not doing octopus and not fast-forward. Need
1391 * a real merge.
1392 */
1393 else if (!remoteheads->next && !common->next && option_commit) {
1394 /*
1395 * We are not doing octopus, not fast-forward, and have
1396 * only one common.
1397 */
1398 refresh_cache(REFRESH_QUIET);
1399 if (allow_trivial && fast_forward != FF_ONLY) {
1400 /* See if it is really trivial. */
1401 git_committer_info(IDENT_STRICT);
1402 printf(_("Trying really trivial in-index merge...\n"));
1403 if (!read_tree_trivial(common->item->object.sha1,
1404 head_commit->object.sha1,
1405 remoteheads->item->object.sha1)) {
1406 ret = merge_trivial(head_commit, remoteheads);
1407 goto done;
1408 }
1409 printf(_("Nope.\n"));
1410 }
1411 } else {
1412 /*
1413 * An octopus. If we can reach all the remote we are up
1414 * to date.
1415 */
1416 int up_to_date = 1;
1417 struct commit_list *j;
1418
1419 for (j = remoteheads; j; j = j->next) {
1420 struct commit_list *common_one;
1421
1422 /*
1423 * Here we *have* to calculate the individual
1424 * merge_bases again, otherwise "git merge HEAD^
1425 * HEAD^^" would be missed.
1426 */
1427 common_one = get_merge_bases(head_commit, j->item, 1);
1428 if (hashcmp(common_one->item->object.sha1,
1429 j->item->object.sha1)) {
1430 up_to_date = 0;
1431 break;
1432 }
1433 }
1434 if (up_to_date) {
1435 finish_up_to_date("Already up-to-date. Yeeah!");
1436 goto done;
1437 }
1438 }
1439
1440 if (fast_forward == FF_ONLY)
1441 die(_("Not possible to fast-forward, aborting."));
1442
1443 /* We are going to make a new commit. */
1444 git_committer_info(IDENT_STRICT);
1445
1446 /*
1447 * At this point, we need a real merge. No matter what strategy
1448 * we use, it would operate on the index, possibly affecting the
1449 * working tree, and when resolved cleanly, have the desired
1450 * tree in the index -- this means that the index must be in
1451 * sync with the head commit. The strategies are responsible
1452 * to ensure this.
1453 */
1454 if (use_strategies_nr == 1 ||
1455 /*
1456 * Stash away the local changes so that we can try more than one.
1457 */
1458 save_state(stash))
1459 hashcpy(stash, null_sha1);
1460
1461 for (i = 0; i < use_strategies_nr; i++) {
1462 int ret;
1463 if (i) {
1464 printf(_("Rewinding the tree to pristine...\n"));
1465 restore_state(head_commit->object.sha1, stash);
1466 }
1467 if (use_strategies_nr != 1)
1468 printf(_("Trying merge strategy %s...\n"),
1469 use_strategies[i]->name);
1470 /*
1471 * Remember which strategy left the state in the working
1472 * tree.
1473 */
1474 wt_strategy = use_strategies[i]->name;
1475
1476 ret = try_merge_strategy(use_strategies[i]->name,
1477 common, remoteheads,
1478 head_commit, head_arg);
1479 if (!option_commit && !ret) {
1480 merge_was_ok = 1;
1481 /*
1482 * This is necessary here just to avoid writing
1483 * the tree, but later we will *not* exit with
1484 * status code 1 because merge_was_ok is set.
1485 */
1486 ret = 1;
1487 }
1488
1489 if (ret) {
1490 /*
1491 * The backend exits with 1 when conflicts are
1492 * left to be resolved, with 2 when it does not
1493 * handle the given merge at all.
1494 */
1495 if (ret == 1) {
1496 int cnt = evaluate_result();
1497
1498 if (best_cnt <= 0 || cnt <= best_cnt) {
1499 best_strategy = use_strategies[i]->name;
1500 best_cnt = cnt;
1501 }
1502 }
1503 if (merge_was_ok)
1504 break;
1505 else
1506 continue;
1507 }
1508
1509 /* Automerge succeeded. */
1510 write_tree_trivial(result_tree);
1511 automerge_was_ok = 1;
1512 break;
1513 }
1514
1515 /*
1516 * If we have a resulting tree, that means the strategy module
1517 * auto resolved the merge cleanly.
1518 */
1519 if (automerge_was_ok) {
1520 ret = finish_automerge(head_commit, head_subsumed,
1521 common, remoteheads,
1522 result_tree, wt_strategy);
1523 goto done;
1524 }
1525
1526 /*
1527 * Pick the result from the best strategy and have the user fix
1528 * it up.
1529 */
1530 if (!best_strategy) {
1531 restore_state(head_commit->object.sha1, stash);
1532 if (use_strategies_nr > 1)
1533 fprintf(stderr,
1534 _("No merge strategy handled the merge.\n"));
1535 else
1536 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1537 use_strategies[0]->name);
1538 ret = 2;
1539 goto done;
1540 } else if (best_strategy == wt_strategy)
1541 ; /* We already have its result in the working tree. */
1542 else {
1543 printf(_("Rewinding the tree to pristine...\n"));
1544 restore_state(head_commit->object.sha1, stash);
1545 printf(_("Using the %s to prepare resolving by hand.\n"),
1546 best_strategy);
1547 try_merge_strategy(best_strategy, common, remoteheads,
1548 head_commit, head_arg);
1549 }
1550
1551 if (squash)
1552 finish(head_commit, remoteheads, NULL, NULL);
1553 else
1554 write_merge_state(remoteheads);
1555
1556 if (merge_was_ok)
1557 fprintf(stderr, _("Automatic merge went well; "
1558 "stopped before committing as requested\n"));
1559 else
1560 ret = suggest_conflicts(option_renormalize);
1561
1562 done:
1563 free(branch_to_free);
1564 return ret;
1565 }