t5500 & t7403: lose bash-ism "local"
[git/git.git] / builtin / merge.c
1 /*
2 * Builtin "git merge"
3 *
4 * Copyright (c) 2008 Miklos Vajna <vmiklos@frugalware.org>
5 *
6 * Based on git-merge.sh by Junio C Hamano.
7 */
8
9 #include "cache.h"
10 #include "parse-options.h"
11 #include "builtin.h"
12 #include "lockfile.h"
13 #include "run-command.h"
14 #include "diff.h"
15 #include "refs.h"
16 #include "commit.h"
17 #include "diffcore.h"
18 #include "revision.h"
19 #include "unpack-trees.h"
20 #include "cache-tree.h"
21 #include "dir.h"
22 #include "utf8.h"
23 #include "log-tree.h"
24 #include "color.h"
25 #include "rerere.h"
26 #include "help.h"
27 #include "merge-recursive.h"
28 #include "resolve-undo.h"
29 #include "remote.h"
30 #include "fmt-merge-msg.h"
31 #include "gpg-interface.h"
32 #include "sequencer.h"
33
34 #define DEFAULT_TWOHEAD (1<<0)
35 #define DEFAULT_OCTOPUS (1<<1)
36 #define NO_FAST_FORWARD (1<<2)
37 #define NO_TRIVIAL (1<<3)
38
39 struct strategy {
40 const char *name;
41 unsigned attr;
42 };
43
44 static const char * const builtin_merge_usage[] = {
45 N_("git merge [<options>] [<commit>...]"),
46 N_("git merge [<options>] <msg> HEAD <commit>"),
47 N_("git merge --abort"),
48 NULL
49 };
50
51 static int show_diffstat = 1, shortlog_len = -1, squash;
52 static int option_commit = 1;
53 static int option_edit = -1;
54 static int allow_trivial = 1, have_message, verify_signatures;
55 static int overwrite_ignore = 1;
56 static struct strbuf merge_msg = STRBUF_INIT;
57 static struct strategy **use_strategies;
58 static size_t use_strategies_nr, use_strategies_alloc;
59 static const char **xopts;
60 static size_t xopts_nr, xopts_alloc;
61 static const char *branch;
62 static char *branch_mergeoptions;
63 static int option_renormalize;
64 static int verbosity;
65 static int allow_rerere_auto;
66 static int abort_current_merge;
67 static int show_progress = -1;
68 static int default_to_upstream = 1;
69 static const char *sign_commit;
70
71 static struct strategy all_strategy[] = {
72 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
73 { "octopus", DEFAULT_OCTOPUS },
74 { "resolve", 0 },
75 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
76 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
77 };
78
79 static const char *pull_twohead, *pull_octopus;
80
81 enum ff_type {
82 FF_NO,
83 FF_ALLOW,
84 FF_ONLY
85 };
86
87 static enum ff_type fast_forward = FF_ALLOW;
88
89 static int option_parse_message(const struct option *opt,
90 const char *arg, int unset)
91 {
92 struct strbuf *buf = opt->value;
93
94 if (unset)
95 strbuf_setlen(buf, 0);
96 else if (arg) {
97 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
98 have_message = 1;
99 } else
100 return error(_("switch `m' requires a value"));
101 return 0;
102 }
103
104 static struct strategy *get_strategy(const char *name)
105 {
106 int i;
107 struct strategy *ret;
108 static struct cmdnames main_cmds, other_cmds;
109 static int loaded;
110
111 if (!name)
112 return NULL;
113
114 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
115 if (!strcmp(name, all_strategy[i].name))
116 return &all_strategy[i];
117
118 if (!loaded) {
119 struct cmdnames not_strategies;
120 loaded = 1;
121
122 memset(&not_strategies, 0, sizeof(struct cmdnames));
123 load_command_list("git-merge-", &main_cmds, &other_cmds);
124 for (i = 0; i < main_cmds.cnt; i++) {
125 int j, found = 0;
126 struct cmdname *ent = main_cmds.names[i];
127 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
128 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
129 && !all_strategy[j].name[ent->len])
130 found = 1;
131 if (!found)
132 add_cmdname(&not_strategies, ent->name, ent->len);
133 }
134 exclude_cmds(&main_cmds, &not_strategies);
135 }
136 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
137 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
138 fprintf(stderr, _("Available strategies are:"));
139 for (i = 0; i < main_cmds.cnt; i++)
140 fprintf(stderr, " %s", main_cmds.names[i]->name);
141 fprintf(stderr, ".\n");
142 if (other_cmds.cnt) {
143 fprintf(stderr, _("Available custom strategies are:"));
144 for (i = 0; i < other_cmds.cnt; i++)
145 fprintf(stderr, " %s", other_cmds.names[i]->name);
146 fprintf(stderr, ".\n");
147 }
148 exit(1);
149 }
150
151 ret = xcalloc(1, sizeof(struct strategy));
152 ret->name = xstrdup(name);
153 ret->attr = NO_TRIVIAL;
154 return ret;
155 }
156
157 static void append_strategy(struct strategy *s)
158 {
159 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
160 use_strategies[use_strategies_nr++] = s;
161 }
162
163 static int option_parse_strategy(const struct option *opt,
164 const char *name, int unset)
165 {
166 if (unset)
167 return 0;
168
169 append_strategy(get_strategy(name));
170 return 0;
171 }
172
173 static int option_parse_x(const struct option *opt,
174 const char *arg, int unset)
175 {
176 if (unset)
177 return 0;
178
179 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
180 xopts[xopts_nr++] = xstrdup(arg);
181 return 0;
182 }
183
184 static int option_parse_n(const struct option *opt,
185 const char *arg, int unset)
186 {
187 show_diffstat = unset;
188 return 0;
189 }
190
191 static struct option builtin_merge_options[] = {
192 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
193 N_("do not show a diffstat at the end of the merge"),
194 PARSE_OPT_NOARG, option_parse_n },
195 OPT_BOOL(0, "stat", &show_diffstat,
196 N_("show a diffstat at the end of the merge")),
197 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
198 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
199 N_("add (at most <n>) entries from shortlog to merge commit message"),
200 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
201 OPT_BOOL(0, "squash", &squash,
202 N_("create a single commit instead of doing a merge")),
203 OPT_BOOL(0, "commit", &option_commit,
204 N_("perform a commit if the merge succeeds (default)")),
205 OPT_BOOL('e', "edit", &option_edit,
206 N_("edit message before committing")),
207 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
208 { OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
209 N_("abort if fast-forward is not possible"),
210 PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
211 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
212 OPT_BOOL(0, "verify-signatures", &verify_signatures,
213 N_("Verify that the named commit has a valid GPG signature")),
214 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
215 N_("merge strategy to use"), option_parse_strategy),
216 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
217 N_("option for selected merge strategy"), option_parse_x),
218 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
219 N_("merge commit message (for a non-fast-forward merge)"),
220 option_parse_message),
221 OPT__VERBOSITY(&verbosity),
222 OPT_BOOL(0, "abort", &abort_current_merge,
223 N_("abort the current in-progress merge")),
224 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
225 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
226 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
227 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
228 OPT_END()
229 };
230
231 /* Cleans up metadata that is uninteresting after a succeeded merge. */
232 static void drop_save(void)
233 {
234 unlink(git_path_merge_head());
235 unlink(git_path_merge_msg());
236 unlink(git_path_merge_mode());
237 }
238
239 static int save_state(unsigned char *stash)
240 {
241 int len;
242 struct child_process cp = CHILD_PROCESS_INIT;
243 struct strbuf buffer = STRBUF_INIT;
244 const char *argv[] = {"stash", "create", NULL};
245
246 cp.argv = argv;
247 cp.out = -1;
248 cp.git_cmd = 1;
249
250 if (start_command(&cp))
251 die(_("could not run stash."));
252 len = strbuf_read(&buffer, cp.out, 1024);
253 close(cp.out);
254
255 if (finish_command(&cp) || len < 0)
256 die(_("stash failed"));
257 else if (!len) /* no changes */
258 return -1;
259 strbuf_setlen(&buffer, buffer.len-1);
260 if (get_sha1(buffer.buf, stash))
261 die(_("not a valid object: %s"), buffer.buf);
262 return 0;
263 }
264
265 static void read_empty(unsigned const char *sha1, int verbose)
266 {
267 int i = 0;
268 const char *args[7];
269
270 args[i++] = "read-tree";
271 if (verbose)
272 args[i++] = "-v";
273 args[i++] = "-m";
274 args[i++] = "-u";
275 args[i++] = EMPTY_TREE_SHA1_HEX;
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 reset_hard(unsigned const char *sha1, int verbose)
284 {
285 int i = 0;
286 const char *args[6];
287
288 args[i++] = "read-tree";
289 if (verbose)
290 args[i++] = "-v";
291 args[i++] = "--reset";
292 args[i++] = "-u";
293 args[i++] = sha1_to_hex(sha1);
294 args[i] = NULL;
295
296 if (run_command_v_opt(args, RUN_GIT_CMD))
297 die(_("read-tree failed"));
298 }
299
300 static void restore_state(const unsigned char *head,
301 const unsigned char *stash)
302 {
303 struct strbuf sb = STRBUF_INIT;
304 const char *args[] = { "stash", "apply", NULL, NULL };
305
306 if (is_null_sha1(stash))
307 return;
308
309 reset_hard(head, 1);
310
311 args[2] = sha1_to_hex(stash);
312
313 /*
314 * It is OK to ignore error here, for example when there was
315 * nothing to restore.
316 */
317 run_command_v_opt(args, RUN_GIT_CMD);
318
319 strbuf_release(&sb);
320 refresh_cache(REFRESH_QUIET);
321 }
322
323 /* This is called when no merge was necessary. */
324 static void finish_up_to_date(const char *msg)
325 {
326 if (verbosity >= 0)
327 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
328 drop_save();
329 }
330
331 static void squash_message(struct commit *commit, struct commit_list *remoteheads)
332 {
333 struct rev_info rev;
334 struct strbuf out = STRBUF_INIT;
335 struct commit_list *j;
336 const char *filename;
337 int fd;
338 struct pretty_print_context ctx = {0};
339
340 printf(_("Squash commit -- not updating HEAD\n"));
341 filename = git_path_squash_msg();
342 fd = open(filename, O_WRONLY | O_CREAT, 0666);
343 if (fd < 0)
344 die_errno(_("Could not write to '%s'"), filename);
345
346 init_revisions(&rev, NULL);
347 rev.ignore_merges = 1;
348 rev.commit_format = CMIT_FMT_MEDIUM;
349
350 commit->object.flags |= UNINTERESTING;
351 add_pending_object(&rev, &commit->object, NULL);
352
353 for (j = remoteheads; j; j = j->next)
354 add_pending_object(&rev, &j->item->object, NULL);
355
356 setup_revisions(0, NULL, &rev, NULL);
357 if (prepare_revision_walk(&rev))
358 die(_("revision walk setup failed"));
359
360 ctx.abbrev = rev.abbrev;
361 ctx.date_mode = rev.date_mode;
362 ctx.fmt = rev.commit_format;
363
364 strbuf_addstr(&out, "Squashed commit of the following:\n");
365 while ((commit = get_revision(&rev)) != NULL) {
366 strbuf_addch(&out, '\n');
367 strbuf_addf(&out, "commit %s\n",
368 oid_to_hex(&commit->object.oid));
369 pretty_print_commit(&ctx, commit, &out);
370 }
371 if (write_in_full(fd, out.buf, out.len) != out.len)
372 die_errno(_("Writing SQUASH_MSG"));
373 if (close(fd))
374 die_errno(_("Finishing SQUASH_MSG"));
375 strbuf_release(&out);
376 }
377
378 static void finish(struct commit *head_commit,
379 struct commit_list *remoteheads,
380 const unsigned char *new_head, const char *msg)
381 {
382 struct strbuf reflog_message = STRBUF_INIT;
383 const unsigned char *head = head_commit->object.oid.hash;
384
385 if (!msg)
386 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
387 else {
388 if (verbosity >= 0)
389 printf("%s\n", msg);
390 strbuf_addf(&reflog_message, "%s: %s",
391 getenv("GIT_REFLOG_ACTION"), msg);
392 }
393 if (squash) {
394 squash_message(head_commit, remoteheads);
395 } else {
396 if (verbosity >= 0 && !merge_msg.len)
397 printf(_("No merge message -- not updating HEAD\n"));
398 else {
399 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
400 update_ref(reflog_message.buf, "HEAD",
401 new_head, head, 0,
402 UPDATE_REFS_DIE_ON_ERR);
403 /*
404 * We ignore errors in 'gc --auto', since the
405 * user should see them.
406 */
407 close_all_packs();
408 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
409 }
410 }
411 if (new_head && show_diffstat) {
412 struct diff_options opts;
413 diff_setup(&opts);
414 opts.stat_width = -1; /* use full terminal width */
415 opts.stat_graph_width = -1; /* respect statGraphWidth config */
416 opts.output_format |=
417 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
418 opts.detect_rename = DIFF_DETECT_RENAME;
419 diff_setup_done(&opts);
420 diff_tree_sha1(head, new_head, "", &opts);
421 diffcore_std(&opts);
422 diff_flush(&opts);
423 }
424
425 /* Run a post-merge hook */
426 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
427
428 strbuf_release(&reflog_message);
429 }
430
431 /* Get the name for the merge commit's message. */
432 static void merge_name(const char *remote, struct strbuf *msg)
433 {
434 struct commit *remote_head;
435 unsigned char branch_head[20];
436 struct strbuf buf = STRBUF_INIT;
437 struct strbuf bname = STRBUF_INIT;
438 const char *ptr;
439 char *found_ref;
440 int len, early;
441
442 strbuf_branchname(&bname, remote);
443 remote = bname.buf;
444
445 memset(branch_head, 0, sizeof(branch_head));
446 remote_head = get_merge_parent(remote);
447 if (!remote_head)
448 die(_("'%s' does not point to a commit"), remote);
449
450 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
451 if (starts_with(found_ref, "refs/heads/")) {
452 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
453 sha1_to_hex(branch_head), remote);
454 goto cleanup;
455 }
456 if (starts_with(found_ref, "refs/tags/")) {
457 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
458 sha1_to_hex(branch_head), remote);
459 goto cleanup;
460 }
461 if (starts_with(found_ref, "refs/remotes/")) {
462 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
463 sha1_to_hex(branch_head), remote);
464 goto cleanup;
465 }
466 }
467
468 /* See if remote matches <name>^^^.. or <name>~<number> */
469 for (len = 0, ptr = remote + strlen(remote);
470 remote < ptr && ptr[-1] == '^';
471 ptr--)
472 len++;
473 if (len)
474 early = 1;
475 else {
476 early = 0;
477 ptr = strrchr(remote, '~');
478 if (ptr) {
479 int seen_nonzero = 0;
480
481 len++; /* count ~ */
482 while (*++ptr && isdigit(*ptr)) {
483 seen_nonzero |= (*ptr != '0');
484 len++;
485 }
486 if (*ptr)
487 len = 0; /* not ...~<number> */
488 else if (seen_nonzero)
489 early = 1;
490 else if (len == 1)
491 early = 1; /* "name~" is "name~1"! */
492 }
493 }
494 if (len) {
495 struct strbuf truname = STRBUF_INIT;
496 strbuf_addf(&truname, "refs/heads/%s", remote);
497 strbuf_setlen(&truname, truname.len - len);
498 if (ref_exists(truname.buf)) {
499 strbuf_addf(msg,
500 "%s\t\tbranch '%s'%s of .\n",
501 sha1_to_hex(remote_head->object.oid.hash),
502 truname.buf + 11,
503 (early ? " (early part)" : ""));
504 strbuf_release(&truname);
505 goto cleanup;
506 }
507 strbuf_release(&truname);
508 }
509
510 if (remote_head->util) {
511 struct merge_remote_desc *desc;
512 desc = merge_remote_util(remote_head);
513 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
514 strbuf_addf(msg, "%s\t\t%s '%s'\n",
515 sha1_to_hex(desc->obj->oid.hash),
516 typename(desc->obj->type),
517 remote);
518 goto cleanup;
519 }
520 }
521
522 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
523 sha1_to_hex(remote_head->object.oid.hash), remote);
524 cleanup:
525 strbuf_release(&buf);
526 strbuf_release(&bname);
527 }
528
529 static void parse_branch_merge_options(char *bmo)
530 {
531 const char **argv;
532 int argc;
533
534 if (!bmo)
535 return;
536 argc = split_cmdline(bmo, &argv);
537 if (argc < 0)
538 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
539 split_cmdline_strerror(argc));
540 REALLOC_ARRAY(argv, argc + 2);
541 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
542 argc++;
543 argv[0] = "branch.*.mergeoptions";
544 parse_options(argc, argv, NULL, builtin_merge_options,
545 builtin_merge_usage, 0);
546 free(argv);
547 }
548
549 static int git_merge_config(const char *k, const char *v, void *cb)
550 {
551 int status;
552
553 if (branch && starts_with(k, "branch.") &&
554 starts_with(k + 7, branch) &&
555 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
556 free(branch_mergeoptions);
557 branch_mergeoptions = xstrdup(v);
558 return 0;
559 }
560
561 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
562 show_diffstat = git_config_bool(k, v);
563 else if (!strcmp(k, "pull.twohead"))
564 return git_config_string(&pull_twohead, k, v);
565 else if (!strcmp(k, "pull.octopus"))
566 return git_config_string(&pull_octopus, k, v);
567 else if (!strcmp(k, "merge.renormalize"))
568 option_renormalize = git_config_bool(k, v);
569 else if (!strcmp(k, "merge.ff")) {
570 int boolval = git_config_maybe_bool(k, v);
571 if (0 <= boolval) {
572 fast_forward = boolval ? FF_ALLOW : FF_NO;
573 } else if (v && !strcmp(v, "only")) {
574 fast_forward = FF_ONLY;
575 } /* do not barf on values from future versions of git */
576 return 0;
577 } else if (!strcmp(k, "merge.defaulttoupstream")) {
578 default_to_upstream = git_config_bool(k, v);
579 return 0;
580 } else if (!strcmp(k, "commit.gpgsign")) {
581 sign_commit = git_config_bool(k, v) ? "" : NULL;
582 return 0;
583 }
584
585 status = fmt_merge_msg_config(k, v, cb);
586 if (status)
587 return status;
588 status = git_gpg_config(k, v, NULL);
589 if (status)
590 return status;
591 return git_diff_ui_config(k, v, cb);
592 }
593
594 static int read_tree_trivial(unsigned char *common, unsigned char *head,
595 unsigned char *one)
596 {
597 int i, nr_trees = 0;
598 struct tree *trees[MAX_UNPACK_TREES];
599 struct tree_desc t[MAX_UNPACK_TREES];
600 struct unpack_trees_options opts;
601
602 memset(&opts, 0, sizeof(opts));
603 opts.head_idx = 2;
604 opts.src_index = &the_index;
605 opts.dst_index = &the_index;
606 opts.update = 1;
607 opts.verbose_update = 1;
608 opts.trivial_merges_only = 1;
609 opts.merge = 1;
610 trees[nr_trees] = parse_tree_indirect(common);
611 if (!trees[nr_trees++])
612 return -1;
613 trees[nr_trees] = parse_tree_indirect(head);
614 if (!trees[nr_trees++])
615 return -1;
616 trees[nr_trees] = parse_tree_indirect(one);
617 if (!trees[nr_trees++])
618 return -1;
619 opts.fn = threeway_merge;
620 cache_tree_free(&active_cache_tree);
621 for (i = 0; i < nr_trees; i++) {
622 parse_tree(trees[i]);
623 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
624 }
625 if (unpack_trees(nr_trees, t, &opts))
626 return -1;
627 return 0;
628 }
629
630 static void write_tree_trivial(unsigned char *sha1)
631 {
632 if (write_cache_as_tree(sha1, 0, NULL))
633 die(_("git write-tree failed to write a tree"));
634 }
635
636 static int try_merge_strategy(const char *strategy, struct commit_list *common,
637 struct commit_list *remoteheads,
638 struct commit *head, const char *head_arg)
639 {
640 static struct lock_file lock;
641
642 hold_locked_index(&lock, 1);
643 refresh_cache(REFRESH_QUIET);
644 if (active_cache_changed &&
645 write_locked_index(&the_index, &lock, COMMIT_LOCK))
646 return error(_("Unable to write index."));
647 rollback_lock_file(&lock);
648
649 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
650 int clean, x;
651 struct commit *result;
652 struct commit_list *reversed = NULL;
653 struct merge_options o;
654 struct commit_list *j;
655
656 if (remoteheads->next) {
657 error(_("Not handling anything other than two heads merge."));
658 return 2;
659 }
660
661 init_merge_options(&o);
662 if (!strcmp(strategy, "subtree"))
663 o.subtree_shift = "";
664
665 o.renormalize = option_renormalize;
666 o.show_rename_progress =
667 show_progress == -1 ? isatty(2) : show_progress;
668
669 for (x = 0; x < xopts_nr; x++)
670 if (parse_merge_opt(&o, xopts[x]))
671 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
672
673 o.branch1 = head_arg;
674 o.branch2 = merge_remote_util(remoteheads->item)->name;
675
676 for (j = common; j; j = j->next)
677 commit_list_insert(j->item, &reversed);
678
679 hold_locked_index(&lock, 1);
680 clean = merge_recursive(&o, head,
681 remoteheads->item, reversed, &result);
682 if (active_cache_changed &&
683 write_locked_index(&the_index, &lock, COMMIT_LOCK))
684 die (_("unable to write %s"), get_index_file());
685 rollback_lock_file(&lock);
686 return clean ? 0 : 1;
687 } else {
688 return try_merge_command(strategy, xopts_nr, xopts,
689 common, head_arg, remoteheads);
690 }
691 }
692
693 static void count_diff_files(struct diff_queue_struct *q,
694 struct diff_options *opt, void *data)
695 {
696 int *count = data;
697
698 (*count) += q->nr;
699 }
700
701 static int count_unmerged_entries(void)
702 {
703 int i, ret = 0;
704
705 for (i = 0; i < active_nr; i++)
706 if (ce_stage(active_cache[i]))
707 ret++;
708
709 return ret;
710 }
711
712 static void split_merge_strategies(const char *string, struct strategy **list,
713 int *nr, int *alloc)
714 {
715 char *p, *q, *buf;
716
717 if (!string)
718 return;
719
720 buf = xstrdup(string);
721 q = buf;
722 for (;;) {
723 p = strchr(q, ' ');
724 if (!p) {
725 ALLOC_GROW(*list, *nr + 1, *alloc);
726 (*list)[(*nr)++].name = xstrdup(q);
727 free(buf);
728 return;
729 } else {
730 *p = '\0';
731 ALLOC_GROW(*list, *nr + 1, *alloc);
732 (*list)[(*nr)++].name = xstrdup(q);
733 q = ++p;
734 }
735 }
736 }
737
738 static void add_strategies(const char *string, unsigned attr)
739 {
740 struct strategy *list = NULL;
741 int list_alloc = 0, list_nr = 0, i;
742
743 memset(&list, 0, sizeof(list));
744 split_merge_strategies(string, &list, &list_nr, &list_alloc);
745 if (list) {
746 for (i = 0; i < list_nr; i++)
747 append_strategy(get_strategy(list[i].name));
748 return;
749 }
750 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
751 if (all_strategy[i].attr & attr)
752 append_strategy(&all_strategy[i]);
753
754 }
755
756 static void write_merge_msg(struct strbuf *msg)
757 {
758 const char *filename = git_path_merge_msg();
759 int fd = open(filename, O_WRONLY | O_CREAT, 0666);
760 if (fd < 0)
761 die_errno(_("Could not open '%s' for writing"),
762 filename);
763 if (write_in_full(fd, msg->buf, msg->len) != msg->len)
764 die_errno(_("Could not write to '%s'"), filename);
765 close(fd);
766 }
767
768 static void read_merge_msg(struct strbuf *msg)
769 {
770 const char *filename = git_path_merge_msg();
771 strbuf_reset(msg);
772 if (strbuf_read_file(msg, filename, 0) < 0)
773 die_errno(_("Could not read from '%s'"), filename);
774 }
775
776 static void write_merge_state(struct commit_list *);
777 static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
778 {
779 if (err_msg)
780 error("%s", err_msg);
781 fprintf(stderr,
782 _("Not committing merge; use 'git commit' to complete the merge.\n"));
783 write_merge_state(remoteheads);
784 exit(1);
785 }
786
787 static const char merge_editor_comment[] =
788 N_("Please enter a commit message to explain why this merge is necessary,\n"
789 "especially if it merges an updated upstream into a topic branch.\n"
790 "\n"
791 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
792 "the commit.\n");
793
794 static void prepare_to_commit(struct commit_list *remoteheads)
795 {
796 struct strbuf msg = STRBUF_INIT;
797 strbuf_addbuf(&msg, &merge_msg);
798 strbuf_addch(&msg, '\n');
799 if (0 < option_edit)
800 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
801 write_merge_msg(&msg);
802 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
803 git_path_merge_msg(), "merge", NULL))
804 abort_commit(remoteheads, NULL);
805 if (0 < option_edit) {
806 if (launch_editor(git_path_merge_msg(), NULL, NULL))
807 abort_commit(remoteheads, NULL);
808 }
809 read_merge_msg(&msg);
810 strbuf_stripspace(&msg, 0 < option_edit);
811 if (!msg.len)
812 abort_commit(remoteheads, _("Empty commit message."));
813 strbuf_release(&merge_msg);
814 strbuf_addbuf(&merge_msg, &msg);
815 strbuf_release(&msg);
816 }
817
818 static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
819 {
820 unsigned char result_tree[20], result_commit[20];
821 struct commit_list *parents, **pptr = &parents;
822
823 write_tree_trivial(result_tree);
824 printf(_("Wonderful.\n"));
825 pptr = commit_list_append(head, pptr);
826 pptr = commit_list_append(remoteheads->item, pptr);
827 prepare_to_commit(remoteheads);
828 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
829 result_commit, NULL, sign_commit))
830 die(_("failed to write commit object"));
831 finish(head, remoteheads, result_commit, "In-index merge");
832 drop_save();
833 return 0;
834 }
835
836 static int finish_automerge(struct commit *head,
837 int head_subsumed,
838 struct commit_list *common,
839 struct commit_list *remoteheads,
840 unsigned char *result_tree,
841 const char *wt_strategy)
842 {
843 struct commit_list *parents = NULL;
844 struct strbuf buf = STRBUF_INIT;
845 unsigned char result_commit[20];
846
847 free_commit_list(common);
848 parents = remoteheads;
849 if (!head_subsumed || fast_forward == FF_NO)
850 commit_list_insert(head, &parents);
851 strbuf_addch(&merge_msg, '\n');
852 prepare_to_commit(remoteheads);
853 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
854 result_commit, NULL, sign_commit))
855 die(_("failed to write commit object"));
856 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
857 finish(head, remoteheads, result_commit, buf.buf);
858 strbuf_release(&buf);
859 drop_save();
860 return 0;
861 }
862
863 static int suggest_conflicts(void)
864 {
865 const char *filename;
866 FILE *fp;
867 struct strbuf msgbuf = STRBUF_INIT;
868
869 filename = git_path_merge_msg();
870 fp = fopen(filename, "a");
871 if (!fp)
872 die_errno(_("Could not open '%s' for writing"), filename);
873
874 append_conflicts_hint(&msgbuf);
875 fputs(msgbuf.buf, fp);
876 strbuf_release(&msgbuf);
877 fclose(fp);
878 rerere(allow_rerere_auto);
879 printf(_("Automatic merge failed; "
880 "fix conflicts and then commit the result.\n"));
881 return 1;
882 }
883
884 static struct commit *is_old_style_invocation(int argc, const char **argv,
885 const unsigned char *head)
886 {
887 struct commit *second_token = NULL;
888 if (argc > 2) {
889 unsigned char second_sha1[20];
890
891 if (get_sha1(argv[1], second_sha1))
892 return NULL;
893 second_token = lookup_commit_reference_gently(second_sha1, 0);
894 if (!second_token)
895 die(_("'%s' is not a commit"), argv[1]);
896 if (hashcmp(second_token->object.oid.hash, head))
897 return NULL;
898 }
899 return second_token;
900 }
901
902 static int evaluate_result(void)
903 {
904 int cnt = 0;
905 struct rev_info rev;
906
907 /* Check how many files differ. */
908 init_revisions(&rev, "");
909 setup_revisions(0, NULL, &rev, NULL);
910 rev.diffopt.output_format |=
911 DIFF_FORMAT_CALLBACK;
912 rev.diffopt.format_callback = count_diff_files;
913 rev.diffopt.format_callback_data = &cnt;
914 run_diff_files(&rev, 0);
915
916 /*
917 * Check how many unmerged entries are
918 * there.
919 */
920 cnt += count_unmerged_entries();
921
922 return cnt;
923 }
924
925 /*
926 * Pretend as if the user told us to merge with the remote-tracking
927 * branch we have for the upstream of the current branch
928 */
929 static int setup_with_upstream(const char ***argv)
930 {
931 struct branch *branch = branch_get(NULL);
932 int i;
933 const char **args;
934
935 if (!branch)
936 die(_("No current branch."));
937 if (!branch->remote_name)
938 die(_("No remote for the current branch."));
939 if (!branch->merge_nr)
940 die(_("No default upstream defined for the current branch."));
941
942 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
943 for (i = 0; i < branch->merge_nr; i++) {
944 if (!branch->merge[i]->dst)
945 die(_("No remote-tracking branch for %s from %s"),
946 branch->merge[i]->src, branch->remote_name);
947 args[i] = branch->merge[i]->dst;
948 }
949 args[i] = NULL;
950 *argv = args;
951 return i;
952 }
953
954 static void write_merge_state(struct commit_list *remoteheads)
955 {
956 const char *filename;
957 int fd;
958 struct commit_list *j;
959 struct strbuf buf = STRBUF_INIT;
960
961 for (j = remoteheads; j; j = j->next) {
962 struct object_id *oid;
963 struct commit *c = j->item;
964 if (c->util && merge_remote_util(c)->obj) {
965 oid = &merge_remote_util(c)->obj->oid;
966 } else {
967 oid = &c->object.oid;
968 }
969 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
970 }
971 filename = git_path_merge_head();
972 fd = open(filename, O_WRONLY | O_CREAT, 0666);
973 if (fd < 0)
974 die_errno(_("Could not open '%s' for writing"), filename);
975 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
976 die_errno(_("Could not write to '%s'"), filename);
977 close(fd);
978 strbuf_addch(&merge_msg, '\n');
979 write_merge_msg(&merge_msg);
980
981 filename = git_path_merge_mode();
982 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
983 if (fd < 0)
984 die_errno(_("Could not open '%s' for writing"), filename);
985 strbuf_reset(&buf);
986 if (fast_forward == FF_NO)
987 strbuf_addf(&buf, "no-ff");
988 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
989 die_errno(_("Could not write to '%s'"), filename);
990 close(fd);
991 }
992
993 static int default_edit_option(void)
994 {
995 static const char name[] = "GIT_MERGE_AUTOEDIT";
996 const char *e = getenv(name);
997 struct stat st_stdin, st_stdout;
998
999 if (have_message)
1000 /* an explicit -m msg without --[no-]edit */
1001 return 0;
1002
1003 if (e) {
1004 int v = git_config_maybe_bool(name, e);
1005 if (v < 0)
1006 die("Bad value '%s' in environment '%s'", e, name);
1007 return v;
1008 }
1009
1010 /* Use editor if stdin and stdout are the same and is a tty */
1011 return (!fstat(0, &st_stdin) &&
1012 !fstat(1, &st_stdout) &&
1013 isatty(0) && isatty(1) &&
1014 st_stdin.st_dev == st_stdout.st_dev &&
1015 st_stdin.st_ino == st_stdout.st_ino &&
1016 st_stdin.st_mode == st_stdout.st_mode);
1017 }
1018
1019 static struct commit_list *reduce_parents(struct commit *head_commit,
1020 int *head_subsumed,
1021 struct commit_list *remoteheads)
1022 {
1023 struct commit_list *parents, **remotes;
1024
1025 /*
1026 * Is the current HEAD reachable from another commit being
1027 * merged? If so we do not want to record it as a parent of
1028 * the resulting merge, unless --no-ff is given. We will flip
1029 * this variable to 0 when we find HEAD among the independent
1030 * tips being merged.
1031 */
1032 *head_subsumed = 1;
1033
1034 /* Find what parents to record by checking independent ones. */
1035 parents = reduce_heads(remoteheads);
1036
1037 remoteheads = NULL;
1038 remotes = &remoteheads;
1039 while (parents) {
1040 struct commit *commit = pop_commit(&parents);
1041 if (commit == head_commit)
1042 *head_subsumed = 0;
1043 else
1044 remotes = &commit_list_insert(commit, remotes)->next;
1045 }
1046 return remoteheads;
1047 }
1048
1049 static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1050 {
1051 struct fmt_merge_msg_opts opts;
1052
1053 memset(&opts, 0, sizeof(opts));
1054 opts.add_title = !have_message;
1055 opts.shortlog_len = shortlog_len;
1056 opts.credit_people = (0 < option_edit);
1057
1058 fmt_merge_msg(merge_names, merge_msg, &opts);
1059 if (merge_msg->len)
1060 strbuf_setlen(merge_msg, merge_msg->len - 1);
1061 }
1062
1063 static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1064 {
1065 const char *filename;
1066 int fd, pos, npos;
1067 struct strbuf fetch_head_file = STRBUF_INIT;
1068
1069 if (!merge_names)
1070 merge_names = &fetch_head_file;
1071
1072 filename = git_path_fetch_head();
1073 fd = open(filename, O_RDONLY);
1074 if (fd < 0)
1075 die_errno(_("could not open '%s' for reading"), filename);
1076
1077 if (strbuf_read(merge_names, fd, 0) < 0)
1078 die_errno(_("could not read '%s'"), filename);
1079 if (close(fd) < 0)
1080 die_errno(_("could not close '%s'"), filename);
1081
1082 for (pos = 0; pos < merge_names->len; pos = npos) {
1083 unsigned char sha1[20];
1084 char *ptr;
1085 struct commit *commit;
1086
1087 ptr = strchr(merge_names->buf + pos, '\n');
1088 if (ptr)
1089 npos = ptr - merge_names->buf + 1;
1090 else
1091 npos = merge_names->len;
1092
1093 if (npos - pos < 40 + 2 ||
1094 get_sha1_hex(merge_names->buf + pos, sha1))
1095 commit = NULL; /* bad */
1096 else if (memcmp(merge_names->buf + pos + 40, "\t\t", 2))
1097 continue; /* not-for-merge */
1098 else {
1099 char saved = merge_names->buf[pos + 40];
1100 merge_names->buf[pos + 40] = '\0';
1101 commit = get_merge_parent(merge_names->buf + pos);
1102 merge_names->buf[pos + 40] = saved;
1103 }
1104 if (!commit) {
1105 if (ptr)
1106 *ptr = '\0';
1107 die("not something we can merge in %s: %s",
1108 filename, merge_names->buf + pos);
1109 }
1110 remotes = &commit_list_insert(commit, remotes)->next;
1111 }
1112
1113 if (merge_names == &fetch_head_file)
1114 strbuf_release(&fetch_head_file);
1115 }
1116
1117 static struct commit_list *collect_parents(struct commit *head_commit,
1118 int *head_subsumed,
1119 int argc, const char **argv,
1120 struct strbuf *merge_msg)
1121 {
1122 int i;
1123 struct commit_list *remoteheads = NULL;
1124 struct commit_list **remotes = &remoteheads;
1125 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1126
1127 if (merge_msg && (!have_message || shortlog_len))
1128 autogen = &merge_names;
1129
1130 if (head_commit)
1131 remotes = &commit_list_insert(head_commit, remotes)->next;
1132
1133 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1134 handle_fetch_head(remotes, autogen);
1135 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1136 } else {
1137 for (i = 0; i < argc; i++) {
1138 struct commit *commit = get_merge_parent(argv[i]);
1139 if (!commit)
1140 help_unknown_ref(argv[i], "merge",
1141 "not something we can merge");
1142 remotes = &commit_list_insert(commit, remotes)->next;
1143 }
1144 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1145 if (autogen) {
1146 struct commit_list *p;
1147 for (p = remoteheads; p; p = p->next)
1148 merge_name(merge_remote_util(p->item)->name, autogen);
1149 }
1150 }
1151
1152 if (autogen) {
1153 prepare_merge_message(autogen, merge_msg);
1154 strbuf_release(autogen);
1155 }
1156
1157 return remoteheads;
1158 }
1159
1160 int cmd_merge(int argc, const char **argv, const char *prefix)
1161 {
1162 unsigned char result_tree[20];
1163 unsigned char stash[20];
1164 unsigned char head_sha1[20];
1165 struct commit *head_commit;
1166 struct strbuf buf = STRBUF_INIT;
1167 const char *head_arg;
1168 int flag, i, ret = 0, head_subsumed;
1169 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1170 struct commit_list *common = NULL;
1171 const char *best_strategy = NULL, *wt_strategy = NULL;
1172 struct commit_list *remoteheads, *p;
1173 void *branch_to_free;
1174
1175 if (argc == 2 && !strcmp(argv[1], "-h"))
1176 usage_with_options(builtin_merge_usage, builtin_merge_options);
1177
1178 /*
1179 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1180 * current branch.
1181 */
1182 branch = branch_to_free = resolve_refdup("HEAD", 0, head_sha1, &flag);
1183 if (branch && starts_with(branch, "refs/heads/"))
1184 branch += 11;
1185 if (!branch || is_null_sha1(head_sha1))
1186 head_commit = NULL;
1187 else
1188 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1189
1190 git_config(git_merge_config, NULL);
1191
1192 if (branch_mergeoptions)
1193 parse_branch_merge_options(branch_mergeoptions);
1194 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1195 builtin_merge_usage, 0);
1196 if (shortlog_len < 0)
1197 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1198
1199 if (verbosity < 0 && show_progress == -1)
1200 show_progress = 0;
1201
1202 if (abort_current_merge) {
1203 int nargc = 2;
1204 const char *nargv[] = {"reset", "--merge", NULL};
1205
1206 if (!file_exists(git_path_merge_head()))
1207 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1208
1209 /* Invoke 'git reset --merge' */
1210 ret = cmd_reset(nargc, nargv, prefix);
1211 goto done;
1212 }
1213
1214 if (read_cache_unmerged())
1215 die_resolve_conflict("merge");
1216
1217 if (file_exists(git_path_merge_head())) {
1218 /*
1219 * There is no unmerged entry, don't advise 'git
1220 * add/rm <file>', just 'git commit'.
1221 */
1222 if (advice_resolve_conflict)
1223 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1224 "Please, commit your changes before you merge."));
1225 else
1226 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1227 }
1228 if (file_exists(git_path_cherry_pick_head())) {
1229 if (advice_resolve_conflict)
1230 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1231 "Please, commit your changes before you merge."));
1232 else
1233 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1234 }
1235 resolve_undo_clear();
1236
1237 if (verbosity < 0)
1238 show_diffstat = 0;
1239
1240 if (squash) {
1241 if (fast_forward == FF_NO)
1242 die(_("You cannot combine --squash with --no-ff."));
1243 option_commit = 0;
1244 }
1245
1246 if (!argc) {
1247 if (default_to_upstream)
1248 argc = setup_with_upstream(&argv);
1249 else
1250 die(_("No commit specified and merge.defaultToUpstream not set."));
1251 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1252 argv[0] = "@{-1}";
1253 }
1254
1255 if (!argc)
1256 usage_with_options(builtin_merge_usage,
1257 builtin_merge_options);
1258
1259 if (!head_commit) {
1260 /*
1261 * If the merged head is a valid one there is no reason
1262 * to forbid "git merge" into a branch yet to be born.
1263 * We do the same for "git pull".
1264 */
1265 unsigned char *remote_head_sha1;
1266 if (squash)
1267 die(_("Squash commit into empty head not supported yet"));
1268 if (fast_forward == FF_NO)
1269 die(_("Non-fast-forward commit does not make sense into "
1270 "an empty head"));
1271 remoteheads = collect_parents(head_commit, &head_subsumed,
1272 argc, argv, NULL);
1273 if (!remoteheads)
1274 die(_("%s - not something we can merge"), argv[0]);
1275 if (remoteheads->next)
1276 die(_("Can merge only exactly one commit into empty head"));
1277 remote_head_sha1 = remoteheads->item->object.oid.hash;
1278 read_empty(remote_head_sha1, 0);
1279 update_ref("initial pull", "HEAD", remote_head_sha1,
1280 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1281 goto done;
1282 }
1283
1284 /*
1285 * This could be traditional "merge <msg> HEAD <commit>..." and
1286 * the way we can tell it is to see if the second token is HEAD,
1287 * but some people might have misused the interface and used a
1288 * commit-ish that is the same as HEAD there instead.
1289 * Traditional format never would have "-m" so it is an
1290 * additional safety measure to check for it.
1291 */
1292 if (!have_message &&
1293 is_old_style_invocation(argc, argv, head_commit->object.oid.hash)) {
1294 warning("old-style 'git merge <msg> HEAD <commit>' is deprecated.");
1295 strbuf_addstr(&merge_msg, argv[0]);
1296 head_arg = argv[1];
1297 argv += 2;
1298 argc -= 2;
1299 remoteheads = collect_parents(head_commit, &head_subsumed,
1300 argc, argv, NULL);
1301 } else {
1302 /* We are invoked directly as the first-class UI. */
1303 head_arg = "HEAD";
1304
1305 /*
1306 * All the rest are the commits being merged; prepare
1307 * the standard merge summary message to be appended
1308 * to the given message.
1309 */
1310 remoteheads = collect_parents(head_commit, &head_subsumed,
1311 argc, argv, &merge_msg);
1312 }
1313
1314 if (!head_commit || !argc)
1315 usage_with_options(builtin_merge_usage,
1316 builtin_merge_options);
1317
1318 if (verify_signatures) {
1319 for (p = remoteheads; p; p = p->next) {
1320 struct commit *commit = p->item;
1321 char hex[GIT_SHA1_HEXSZ + 1];
1322 struct signature_check signature_check;
1323 memset(&signature_check, 0, sizeof(signature_check));
1324
1325 check_commit_signature(commit, &signature_check);
1326
1327 find_unique_abbrev_r(hex, commit->object.oid.hash, DEFAULT_ABBREV);
1328 switch (signature_check.result) {
1329 case 'G':
1330 break;
1331 case 'U':
1332 die(_("Commit %s has an untrusted GPG signature, "
1333 "allegedly by %s."), hex, signature_check.signer);
1334 case 'B':
1335 die(_("Commit %s has a bad GPG signature "
1336 "allegedly by %s."), hex, signature_check.signer);
1337 default: /* 'N' */
1338 die(_("Commit %s does not have a GPG signature."), hex);
1339 }
1340 if (verbosity >= 0 && signature_check.result == 'G')
1341 printf(_("Commit %s has a good GPG signature by %s\n"),
1342 hex, signature_check.signer);
1343
1344 signature_check_clear(&signature_check);
1345 }
1346 }
1347
1348 strbuf_addstr(&buf, "merge");
1349 for (p = remoteheads; p; p = p->next)
1350 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1351 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1352 strbuf_reset(&buf);
1353
1354 for (p = remoteheads; p; p = p->next) {
1355 struct commit *commit = p->item;
1356 strbuf_addf(&buf, "GITHEAD_%s",
1357 sha1_to_hex(commit->object.oid.hash));
1358 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1359 strbuf_reset(&buf);
1360 if (fast_forward != FF_ONLY &&
1361 merge_remote_util(commit) &&
1362 merge_remote_util(commit)->obj &&
1363 merge_remote_util(commit)->obj->type == OBJ_TAG)
1364 fast_forward = FF_NO;
1365 }
1366
1367 if (option_edit < 0)
1368 option_edit = default_edit_option();
1369
1370 if (!use_strategies) {
1371 if (!remoteheads)
1372 ; /* already up-to-date */
1373 else if (!remoteheads->next)
1374 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1375 else
1376 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1377 }
1378
1379 for (i = 0; i < use_strategies_nr; i++) {
1380 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1381 fast_forward = FF_NO;
1382 if (use_strategies[i]->attr & NO_TRIVIAL)
1383 allow_trivial = 0;
1384 }
1385
1386 if (!remoteheads)
1387 ; /* already up-to-date */
1388 else if (!remoteheads->next)
1389 common = get_merge_bases(head_commit, remoteheads->item);
1390 else {
1391 struct commit_list *list = remoteheads;
1392 commit_list_insert(head_commit, &list);
1393 common = get_octopus_merge_bases(list);
1394 free(list);
1395 }
1396
1397 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.oid.hash,
1398 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1399
1400 if (remoteheads && !common)
1401 ; /* No common ancestors found. We need a real merge. */
1402 else if (!remoteheads ||
1403 (!remoteheads->next && !common->next &&
1404 common->item == remoteheads->item)) {
1405 /*
1406 * If head can reach all the merge then we are up to date.
1407 * but first the most common case of merging one remote.
1408 */
1409 finish_up_to_date("Already up-to-date.");
1410 goto done;
1411 } else if (fast_forward != FF_NO && !remoteheads->next &&
1412 !common->next &&
1413 !hashcmp(common->item->object.oid.hash, head_commit->object.oid.hash)) {
1414 /* Again the most common case of merging one remote. */
1415 struct strbuf msg = STRBUF_INIT;
1416 struct commit *commit;
1417
1418 if (verbosity >= 0) {
1419 char from[GIT_SHA1_HEXSZ + 1], to[GIT_SHA1_HEXSZ + 1];
1420 find_unique_abbrev_r(from, head_commit->object.oid.hash,
1421 DEFAULT_ABBREV);
1422 find_unique_abbrev_r(to, remoteheads->item->object.oid.hash,
1423 DEFAULT_ABBREV);
1424 printf(_("Updating %s..%s\n"), from, to);
1425 }
1426 strbuf_addstr(&msg, "Fast-forward");
1427 if (have_message)
1428 strbuf_addstr(&msg,
1429 " (no commit created; -m option ignored)");
1430 commit = remoteheads->item;
1431 if (!commit) {
1432 ret = 1;
1433 goto done;
1434 }
1435
1436 if (checkout_fast_forward(head_commit->object.oid.hash,
1437 commit->object.oid.hash,
1438 overwrite_ignore)) {
1439 ret = 1;
1440 goto done;
1441 }
1442
1443 finish(head_commit, remoteheads, commit->object.oid.hash, msg.buf);
1444 drop_save();
1445 goto done;
1446 } else if (!remoteheads->next && common->next)
1447 ;
1448 /*
1449 * We are not doing octopus and not fast-forward. Need
1450 * a real merge.
1451 */
1452 else if (!remoteheads->next && !common->next && option_commit) {
1453 /*
1454 * We are not doing octopus, not fast-forward, and have
1455 * only one common.
1456 */
1457 refresh_cache(REFRESH_QUIET);
1458 if (allow_trivial && fast_forward != FF_ONLY) {
1459 /* See if it is really trivial. */
1460 git_committer_info(IDENT_STRICT);
1461 printf(_("Trying really trivial in-index merge...\n"));
1462 if (!read_tree_trivial(common->item->object.oid.hash,
1463 head_commit->object.oid.hash,
1464 remoteheads->item->object.oid.hash)) {
1465 ret = merge_trivial(head_commit, remoteheads);
1466 goto done;
1467 }
1468 printf(_("Nope.\n"));
1469 }
1470 } else {
1471 /*
1472 * An octopus. If we can reach all the remote we are up
1473 * to date.
1474 */
1475 int up_to_date = 1;
1476 struct commit_list *j;
1477
1478 for (j = remoteheads; j; j = j->next) {
1479 struct commit_list *common_one;
1480
1481 /*
1482 * Here we *have* to calculate the individual
1483 * merge_bases again, otherwise "git merge HEAD^
1484 * HEAD^^" would be missed.
1485 */
1486 common_one = get_merge_bases(head_commit, j->item);
1487 if (hashcmp(common_one->item->object.oid.hash,
1488 j->item->object.oid.hash)) {
1489 up_to_date = 0;
1490 break;
1491 }
1492 }
1493 if (up_to_date) {
1494 finish_up_to_date("Already up-to-date. Yeeah!");
1495 goto done;
1496 }
1497 }
1498
1499 if (fast_forward == FF_ONLY)
1500 die(_("Not possible to fast-forward, aborting."));
1501
1502 /* We are going to make a new commit. */
1503 git_committer_info(IDENT_STRICT);
1504
1505 /*
1506 * At this point, we need a real merge. No matter what strategy
1507 * we use, it would operate on the index, possibly affecting the
1508 * working tree, and when resolved cleanly, have the desired
1509 * tree in the index -- this means that the index must be in
1510 * sync with the head commit. The strategies are responsible
1511 * to ensure this.
1512 */
1513 if (use_strategies_nr == 1 ||
1514 /*
1515 * Stash away the local changes so that we can try more than one.
1516 */
1517 save_state(stash))
1518 hashcpy(stash, null_sha1);
1519
1520 for (i = 0; i < use_strategies_nr; i++) {
1521 int ret;
1522 if (i) {
1523 printf(_("Rewinding the tree to pristine...\n"));
1524 restore_state(head_commit->object.oid.hash, stash);
1525 }
1526 if (use_strategies_nr != 1)
1527 printf(_("Trying merge strategy %s...\n"),
1528 use_strategies[i]->name);
1529 /*
1530 * Remember which strategy left the state in the working
1531 * tree.
1532 */
1533 wt_strategy = use_strategies[i]->name;
1534
1535 ret = try_merge_strategy(use_strategies[i]->name,
1536 common, remoteheads,
1537 head_commit, head_arg);
1538 if (!option_commit && !ret) {
1539 merge_was_ok = 1;
1540 /*
1541 * This is necessary here just to avoid writing
1542 * the tree, but later we will *not* exit with
1543 * status code 1 because merge_was_ok is set.
1544 */
1545 ret = 1;
1546 }
1547
1548 if (ret) {
1549 /*
1550 * The backend exits with 1 when conflicts are
1551 * left to be resolved, with 2 when it does not
1552 * handle the given merge at all.
1553 */
1554 if (ret == 1) {
1555 int cnt = evaluate_result();
1556
1557 if (best_cnt <= 0 || cnt <= best_cnt) {
1558 best_strategy = use_strategies[i]->name;
1559 best_cnt = cnt;
1560 }
1561 }
1562 if (merge_was_ok)
1563 break;
1564 else
1565 continue;
1566 }
1567
1568 /* Automerge succeeded. */
1569 write_tree_trivial(result_tree);
1570 automerge_was_ok = 1;
1571 break;
1572 }
1573
1574 /*
1575 * If we have a resulting tree, that means the strategy module
1576 * auto resolved the merge cleanly.
1577 */
1578 if (automerge_was_ok) {
1579 ret = finish_automerge(head_commit, head_subsumed,
1580 common, remoteheads,
1581 result_tree, wt_strategy);
1582 goto done;
1583 }
1584
1585 /*
1586 * Pick the result from the best strategy and have the user fix
1587 * it up.
1588 */
1589 if (!best_strategy) {
1590 restore_state(head_commit->object.oid.hash, stash);
1591 if (use_strategies_nr > 1)
1592 fprintf(stderr,
1593 _("No merge strategy handled the merge.\n"));
1594 else
1595 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1596 use_strategies[0]->name);
1597 ret = 2;
1598 goto done;
1599 } else if (best_strategy == wt_strategy)
1600 ; /* We already have its result in the working tree. */
1601 else {
1602 printf(_("Rewinding the tree to pristine...\n"));
1603 restore_state(head_commit->object.oid.hash, stash);
1604 printf(_("Using the %s to prepare resolving by hand.\n"),
1605 best_strategy);
1606 try_merge_strategy(best_strategy, common, remoteheads,
1607 head_commit, head_arg);
1608 }
1609
1610 if (squash)
1611 finish(head_commit, remoteheads, NULL, NULL);
1612 else
1613 write_merge_state(remoteheads);
1614
1615 if (merge_was_ok)
1616 fprintf(stderr, _("Automatic merge went well; "
1617 "stopped before committing as requested\n"));
1618 else
1619 ret = suggest_conflicts();
1620
1621 done:
1622 free(branch_to_free);
1623 return ret;
1624 }