use sha1_to_hex_r() instead of strcpy
[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 sha1_to_hex(commit->object.sha1));
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.sha1;
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 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
408 }
409 }
410 if (new_head && show_diffstat) {
411 struct diff_options opts;
412 diff_setup(&opts);
413 opts.stat_width = -1; /* use full terminal width */
414 opts.stat_graph_width = -1; /* respect statGraphWidth config */
415 opts.output_format |=
416 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
417 opts.detect_rename = DIFF_DETECT_RENAME;
418 diff_setup_done(&opts);
419 diff_tree_sha1(head, new_head, "", &opts);
420 diffcore_std(&opts);
421 diff_flush(&opts);
422 }
423
424 /* Run a post-merge hook */
425 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
426
427 strbuf_release(&reflog_message);
428 }
429
430 /* Get the name for the merge commit's message. */
431 static void merge_name(const char *remote, struct strbuf *msg)
432 {
433 struct commit *remote_head;
434 unsigned char branch_head[20];
435 struct strbuf buf = STRBUF_INIT;
436 struct strbuf bname = STRBUF_INIT;
437 const char *ptr;
438 char *found_ref;
439 int len, early;
440
441 strbuf_branchname(&bname, remote);
442 remote = bname.buf;
443
444 memset(branch_head, 0, sizeof(branch_head));
445 remote_head = get_merge_parent(remote);
446 if (!remote_head)
447 die(_("'%s' does not point to a commit"), remote);
448
449 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
450 if (starts_with(found_ref, "refs/heads/")) {
451 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
452 sha1_to_hex(branch_head), remote);
453 goto cleanup;
454 }
455 if (starts_with(found_ref, "refs/tags/")) {
456 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
457 sha1_to_hex(branch_head), remote);
458 goto cleanup;
459 }
460 if (starts_with(found_ref, "refs/remotes/")) {
461 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
462 sha1_to_hex(branch_head), remote);
463 goto cleanup;
464 }
465 }
466
467 /* See if remote matches <name>^^^.. or <name>~<number> */
468 for (len = 0, ptr = remote + strlen(remote);
469 remote < ptr && ptr[-1] == '^';
470 ptr--)
471 len++;
472 if (len)
473 early = 1;
474 else {
475 early = 0;
476 ptr = strrchr(remote, '~');
477 if (ptr) {
478 int seen_nonzero = 0;
479
480 len++; /* count ~ */
481 while (*++ptr && isdigit(*ptr)) {
482 seen_nonzero |= (*ptr != '0');
483 len++;
484 }
485 if (*ptr)
486 len = 0; /* not ...~<number> */
487 else if (seen_nonzero)
488 early = 1;
489 else if (len == 1)
490 early = 1; /* "name~" is "name~1"! */
491 }
492 }
493 if (len) {
494 struct strbuf truname = STRBUF_INIT;
495 strbuf_addf(&truname, "refs/heads/%s", 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 strbuf_release(&truname);
507 }
508
509 if (remote_head->util) {
510 struct merge_remote_desc *desc;
511 desc = merge_remote_util(remote_head);
512 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
513 strbuf_addf(msg, "%s\t\t%s '%s'\n",
514 sha1_to_hex(desc->obj->sha1),
515 typename(desc->obj->type),
516 remote);
517 goto cleanup;
518 }
519 }
520
521 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
522 sha1_to_hex(remote_head->object.sha1), remote);
523 cleanup:
524 strbuf_release(&buf);
525 strbuf_release(&bname);
526 }
527
528 static void parse_branch_merge_options(char *bmo)
529 {
530 const char **argv;
531 int argc;
532
533 if (!bmo)
534 return;
535 argc = split_cmdline(bmo, &argv);
536 if (argc < 0)
537 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
538 split_cmdline_strerror(argc));
539 REALLOC_ARRAY(argv, argc + 2);
540 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
541 argc++;
542 argv[0] = "branch.*.mergeoptions";
543 parse_options(argc, argv, NULL, builtin_merge_options,
544 builtin_merge_usage, 0);
545 free(argv);
546 }
547
548 static int git_merge_config(const char *k, const char *v, void *cb)
549 {
550 int status;
551
552 if (branch && starts_with(k, "branch.") &&
553 starts_with(k + 7, branch) &&
554 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
555 free(branch_mergeoptions);
556 branch_mergeoptions = xstrdup(v);
557 return 0;
558 }
559
560 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
561 show_diffstat = git_config_bool(k, v);
562 else if (!strcmp(k, "pull.twohead"))
563 return git_config_string(&pull_twohead, k, v);
564 else if (!strcmp(k, "pull.octopus"))
565 return git_config_string(&pull_octopus, k, v);
566 else if (!strcmp(k, "merge.renormalize"))
567 option_renormalize = git_config_bool(k, v);
568 else if (!strcmp(k, "merge.ff")) {
569 int boolval = git_config_maybe_bool(k, v);
570 if (0 <= boolval) {
571 fast_forward = boolval ? FF_ALLOW : FF_NO;
572 } else if (v && !strcmp(v, "only")) {
573 fast_forward = FF_ONLY;
574 } /* do not barf on values from future versions of git */
575 return 0;
576 } else if (!strcmp(k, "merge.defaulttoupstream")) {
577 default_to_upstream = git_config_bool(k, v);
578 return 0;
579 } else if (!strcmp(k, "commit.gpgsign")) {
580 sign_commit = git_config_bool(k, v) ? "" : NULL;
581 return 0;
582 }
583
584 status = fmt_merge_msg_config(k, v, cb);
585 if (status)
586 return status;
587 status = git_gpg_config(k, v, NULL);
588 if (status)
589 return status;
590 return git_diff_ui_config(k, v, cb);
591 }
592
593 static int read_tree_trivial(unsigned char *common, unsigned char *head,
594 unsigned char *one)
595 {
596 int i, nr_trees = 0;
597 struct tree *trees[MAX_UNPACK_TREES];
598 struct tree_desc t[MAX_UNPACK_TREES];
599 struct unpack_trees_options opts;
600
601 memset(&opts, 0, sizeof(opts));
602 opts.head_idx = 2;
603 opts.src_index = &the_index;
604 opts.dst_index = &the_index;
605 opts.update = 1;
606 opts.verbose_update = 1;
607 opts.trivial_merges_only = 1;
608 opts.merge = 1;
609 trees[nr_trees] = parse_tree_indirect(common);
610 if (!trees[nr_trees++])
611 return -1;
612 trees[nr_trees] = parse_tree_indirect(head);
613 if (!trees[nr_trees++])
614 return -1;
615 trees[nr_trees] = parse_tree_indirect(one);
616 if (!trees[nr_trees++])
617 return -1;
618 opts.fn = threeway_merge;
619 cache_tree_free(&active_cache_tree);
620 for (i = 0; i < nr_trees; i++) {
621 parse_tree(trees[i]);
622 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
623 }
624 if (unpack_trees(nr_trees, t, &opts))
625 return -1;
626 return 0;
627 }
628
629 static void write_tree_trivial(unsigned char *sha1)
630 {
631 if (write_cache_as_tree(sha1, 0, NULL))
632 die(_("git write-tree failed to write a tree"));
633 }
634
635 static int try_merge_strategy(const char *strategy, struct commit_list *common,
636 struct commit_list *remoteheads,
637 struct commit *head, const char *head_arg)
638 {
639 static struct lock_file lock;
640
641 hold_locked_index(&lock, 1);
642 refresh_cache(REFRESH_QUIET);
643 if (active_cache_changed &&
644 write_locked_index(&the_index, &lock, COMMIT_LOCK))
645 return error(_("Unable to write index."));
646 rollback_lock_file(&lock);
647
648 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
649 int clean, x;
650 struct commit *result;
651 struct commit_list *reversed = NULL;
652 struct merge_options o;
653 struct commit_list *j;
654
655 if (remoteheads->next) {
656 error(_("Not handling anything other than two heads merge."));
657 return 2;
658 }
659
660 init_merge_options(&o);
661 if (!strcmp(strategy, "subtree"))
662 o.subtree_shift = "";
663
664 o.renormalize = option_renormalize;
665 o.show_rename_progress =
666 show_progress == -1 ? isatty(2) : show_progress;
667
668 for (x = 0; x < xopts_nr; x++)
669 if (parse_merge_opt(&o, xopts[x]))
670 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
671
672 o.branch1 = head_arg;
673 o.branch2 = merge_remote_util(remoteheads->item)->name;
674
675 for (j = common; j; j = j->next)
676 commit_list_insert(j->item, &reversed);
677
678 hold_locked_index(&lock, 1);
679 clean = merge_recursive(&o, head,
680 remoteheads->item, reversed, &result);
681 if (active_cache_changed &&
682 write_locked_index(&the_index, &lock, COMMIT_LOCK))
683 die (_("unable to write %s"), get_index_file());
684 rollback_lock_file(&lock);
685 return clean ? 0 : 1;
686 } else {
687 return try_merge_command(strategy, xopts_nr, xopts,
688 common, head_arg, remoteheads);
689 }
690 }
691
692 static void count_diff_files(struct diff_queue_struct *q,
693 struct diff_options *opt, void *data)
694 {
695 int *count = data;
696
697 (*count) += q->nr;
698 }
699
700 static int count_unmerged_entries(void)
701 {
702 int i, ret = 0;
703
704 for (i = 0; i < active_nr; i++)
705 if (ce_stage(active_cache[i]))
706 ret++;
707
708 return ret;
709 }
710
711 static void split_merge_strategies(const char *string, struct strategy **list,
712 int *nr, int *alloc)
713 {
714 char *p, *q, *buf;
715
716 if (!string)
717 return;
718
719 buf = xstrdup(string);
720 q = buf;
721 for (;;) {
722 p = strchr(q, ' ');
723 if (!p) {
724 ALLOC_GROW(*list, *nr + 1, *alloc);
725 (*list)[(*nr)++].name = xstrdup(q);
726 free(buf);
727 return;
728 } else {
729 *p = '\0';
730 ALLOC_GROW(*list, *nr + 1, *alloc);
731 (*list)[(*nr)++].name = xstrdup(q);
732 q = ++p;
733 }
734 }
735 }
736
737 static void add_strategies(const char *string, unsigned attr)
738 {
739 struct strategy *list = NULL;
740 int list_alloc = 0, list_nr = 0, i;
741
742 memset(&list, 0, sizeof(list));
743 split_merge_strategies(string, &list, &list_nr, &list_alloc);
744 if (list) {
745 for (i = 0; i < list_nr; i++)
746 append_strategy(get_strategy(list[i].name));
747 return;
748 }
749 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
750 if (all_strategy[i].attr & attr)
751 append_strategy(&all_strategy[i]);
752
753 }
754
755 static void write_merge_msg(struct strbuf *msg)
756 {
757 const char *filename = git_path_merge_msg();
758 int fd = open(filename, O_WRONLY | O_CREAT, 0666);
759 if (fd < 0)
760 die_errno(_("Could not open '%s' for writing"),
761 filename);
762 if (write_in_full(fd, msg->buf, msg->len) != msg->len)
763 die_errno(_("Could not write to '%s'"), filename);
764 close(fd);
765 }
766
767 static void read_merge_msg(struct strbuf *msg)
768 {
769 const char *filename = git_path_merge_msg();
770 strbuf_reset(msg);
771 if (strbuf_read_file(msg, filename, 0) < 0)
772 die_errno(_("Could not read from '%s'"), filename);
773 }
774
775 static void write_merge_state(struct commit_list *);
776 static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
777 {
778 if (err_msg)
779 error("%s", err_msg);
780 fprintf(stderr,
781 _("Not committing merge; use 'git commit' to complete the merge.\n"));
782 write_merge_state(remoteheads);
783 exit(1);
784 }
785
786 static const char merge_editor_comment[] =
787 N_("Please enter a commit message to explain why this merge is necessary,\n"
788 "especially if it merges an updated upstream into a topic branch.\n"
789 "\n"
790 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
791 "the commit.\n");
792
793 static void prepare_to_commit(struct commit_list *remoteheads)
794 {
795 struct strbuf msg = STRBUF_INIT;
796 strbuf_addbuf(&msg, &merge_msg);
797 strbuf_addch(&msg, '\n');
798 if (0 < option_edit)
799 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
800 write_merge_msg(&msg);
801 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
802 git_path_merge_msg(), "merge", NULL))
803 abort_commit(remoteheads, NULL);
804 if (0 < option_edit) {
805 if (launch_editor(git_path_merge_msg(), NULL, NULL))
806 abort_commit(remoteheads, NULL);
807 }
808 read_merge_msg(&msg);
809 stripspace(&msg, 0 < option_edit);
810 if (!msg.len)
811 abort_commit(remoteheads, _("Empty commit message."));
812 strbuf_release(&merge_msg);
813 strbuf_addbuf(&merge_msg, &msg);
814 strbuf_release(&msg);
815 }
816
817 static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
818 {
819 unsigned char result_tree[20], result_commit[20];
820 struct commit_list *parents, **pptr = &parents;
821
822 write_tree_trivial(result_tree);
823 printf(_("Wonderful.\n"));
824 pptr = commit_list_append(head, pptr);
825 pptr = commit_list_append(remoteheads->item, pptr);
826 prepare_to_commit(remoteheads);
827 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
828 result_commit, NULL, sign_commit))
829 die(_("failed to write commit object"));
830 finish(head, remoteheads, result_commit, "In-index merge");
831 drop_save();
832 return 0;
833 }
834
835 static int finish_automerge(struct commit *head,
836 int head_subsumed,
837 struct commit_list *common,
838 struct commit_list *remoteheads,
839 unsigned char *result_tree,
840 const char *wt_strategy)
841 {
842 struct commit_list *parents = NULL;
843 struct strbuf buf = STRBUF_INIT;
844 unsigned char result_commit[20];
845
846 free_commit_list(common);
847 parents = remoteheads;
848 if (!head_subsumed || fast_forward == FF_NO)
849 commit_list_insert(head, &parents);
850 strbuf_addch(&merge_msg, '\n');
851 prepare_to_commit(remoteheads);
852 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
853 result_commit, NULL, sign_commit))
854 die(_("failed to write commit object"));
855 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
856 finish(head, remoteheads, result_commit, buf.buf);
857 strbuf_release(&buf);
858 drop_save();
859 return 0;
860 }
861
862 static int suggest_conflicts(void)
863 {
864 const char *filename;
865 FILE *fp;
866 struct strbuf msgbuf = STRBUF_INIT;
867
868 filename = git_path_merge_msg();
869 fp = fopen(filename, "a");
870 if (!fp)
871 die_errno(_("Could not open '%s' for writing"), filename);
872
873 append_conflicts_hint(&msgbuf);
874 fputs(msgbuf.buf, fp);
875 strbuf_release(&msgbuf);
876 fclose(fp);
877 rerere(allow_rerere_auto);
878 printf(_("Automatic merge failed; "
879 "fix conflicts and then commit the result.\n"));
880 return 1;
881 }
882
883 static struct commit *is_old_style_invocation(int argc, const char **argv,
884 const unsigned char *head)
885 {
886 struct commit *second_token = NULL;
887 if (argc > 2) {
888 unsigned char second_sha1[20];
889
890 if (get_sha1(argv[1], second_sha1))
891 return NULL;
892 second_token = lookup_commit_reference_gently(second_sha1, 0);
893 if (!second_token)
894 die(_("'%s' is not a commit"), argv[1]);
895 if (hashcmp(second_token->object.sha1, head))
896 return NULL;
897 }
898 return second_token;
899 }
900
901 static int evaluate_result(void)
902 {
903 int cnt = 0;
904 struct rev_info rev;
905
906 /* Check how many files differ. */
907 init_revisions(&rev, "");
908 setup_revisions(0, NULL, &rev, NULL);
909 rev.diffopt.output_format |=
910 DIFF_FORMAT_CALLBACK;
911 rev.diffopt.format_callback = count_diff_files;
912 rev.diffopt.format_callback_data = &cnt;
913 run_diff_files(&rev, 0);
914
915 /*
916 * Check how many unmerged entries are
917 * there.
918 */
919 cnt += count_unmerged_entries();
920
921 return cnt;
922 }
923
924 /*
925 * Pretend as if the user told us to merge with the remote-tracking
926 * branch we have for the upstream of the current branch
927 */
928 static int setup_with_upstream(const char ***argv)
929 {
930 struct branch *branch = branch_get(NULL);
931 int i;
932 const char **args;
933
934 if (!branch)
935 die(_("No current branch."));
936 if (!branch->remote_name)
937 die(_("No remote for the current branch."));
938 if (!branch->merge_nr)
939 die(_("No default upstream defined for the current branch."));
940
941 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
942 for (i = 0; i < branch->merge_nr; i++) {
943 if (!branch->merge[i]->dst)
944 die(_("No remote-tracking branch for %s from %s"),
945 branch->merge[i]->src, branch->remote_name);
946 args[i] = branch->merge[i]->dst;
947 }
948 args[i] = NULL;
949 *argv = args;
950 return i;
951 }
952
953 static void write_merge_state(struct commit_list *remoteheads)
954 {
955 const char *filename;
956 int fd;
957 struct commit_list *j;
958 struct strbuf buf = STRBUF_INIT;
959
960 for (j = remoteheads; j; j = j->next) {
961 unsigned const char *sha1;
962 struct commit *c = j->item;
963 if (c->util && merge_remote_util(c)->obj) {
964 sha1 = merge_remote_util(c)->obj->sha1;
965 } else {
966 sha1 = c->object.sha1;
967 }
968 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
969 }
970 filename = git_path_merge_head();
971 fd = open(filename, O_WRONLY | O_CREAT, 0666);
972 if (fd < 0)
973 die_errno(_("Could not open '%s' for writing"), filename);
974 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
975 die_errno(_("Could not write to '%s'"), filename);
976 close(fd);
977 strbuf_addch(&merge_msg, '\n');
978 write_merge_msg(&merge_msg);
979
980 filename = git_path_merge_mode();
981 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
982 if (fd < 0)
983 die_errno(_("Could not open '%s' for writing"), filename);
984 strbuf_reset(&buf);
985 if (fast_forward == FF_NO)
986 strbuf_addf(&buf, "no-ff");
987 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
988 die_errno(_("Could not write to '%s'"), filename);
989 close(fd);
990 }
991
992 static int default_edit_option(void)
993 {
994 static const char name[] = "GIT_MERGE_AUTOEDIT";
995 const char *e = getenv(name);
996 struct stat st_stdin, st_stdout;
997
998 if (have_message)
999 /* an explicit -m msg without --[no-]edit */
1000 return 0;
1001
1002 if (e) {
1003 int v = git_config_maybe_bool(name, e);
1004 if (v < 0)
1005 die("Bad value '%s' in environment '%s'", e, name);
1006 return v;
1007 }
1008
1009 /* Use editor if stdin and stdout are the same and is a tty */
1010 return (!fstat(0, &st_stdin) &&
1011 !fstat(1, &st_stdout) &&
1012 isatty(0) && isatty(1) &&
1013 st_stdin.st_dev == st_stdout.st_dev &&
1014 st_stdin.st_ino == st_stdout.st_ino &&
1015 st_stdin.st_mode == st_stdout.st_mode);
1016 }
1017
1018 static struct commit_list *reduce_parents(struct commit *head_commit,
1019 int *head_subsumed,
1020 struct commit_list *remoteheads)
1021 {
1022 struct commit_list *parents, *next, **remotes = &remoteheads;
1023
1024 /*
1025 * Is the current HEAD reachable from another commit being
1026 * merged? If so we do not want to record it as a parent of
1027 * the resulting merge, unless --no-ff is given. We will flip
1028 * this variable to 0 when we find HEAD among the independent
1029 * tips being merged.
1030 */
1031 *head_subsumed = 1;
1032
1033 /* Find what parents to record by checking independent ones. */
1034 parents = reduce_heads(remoteheads);
1035
1036 for (remoteheads = NULL, remotes = &remoteheads;
1037 parents;
1038 parents = next) {
1039 struct commit *commit = parents->item;
1040 next = parents->next;
1041 if (commit == head_commit)
1042 *head_subsumed = 0;
1043 else
1044 remotes = &commit_list_insert(commit, remotes)->next;
1045 free(parents);
1046 }
1047 return remoteheads;
1048 }
1049
1050 static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1051 {
1052 struct fmt_merge_msg_opts opts;
1053
1054 memset(&opts, 0, sizeof(opts));
1055 opts.add_title = !have_message;
1056 opts.shortlog_len = shortlog_len;
1057 opts.credit_people = (0 < option_edit);
1058
1059 fmt_merge_msg(merge_names, merge_msg, &opts);
1060 if (merge_msg->len)
1061 strbuf_setlen(merge_msg, merge_msg->len - 1);
1062 }
1063
1064 static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1065 {
1066 const char *filename;
1067 int fd, pos, npos;
1068 struct strbuf fetch_head_file = STRBUF_INIT;
1069
1070 if (!merge_names)
1071 merge_names = &fetch_head_file;
1072
1073 filename = git_path_fetch_head();
1074 fd = open(filename, O_RDONLY);
1075 if (fd < 0)
1076 die_errno(_("could not open '%s' for reading"), filename);
1077
1078 if (strbuf_read(merge_names, fd, 0) < 0)
1079 die_errno(_("could not read '%s'"), filename);
1080 if (close(fd) < 0)
1081 die_errno(_("could not close '%s'"), filename);
1082
1083 for (pos = 0; pos < merge_names->len; pos = npos) {
1084 unsigned char sha1[20];
1085 char *ptr;
1086 struct commit *commit;
1087
1088 ptr = strchr(merge_names->buf + pos, '\n');
1089 if (ptr)
1090 npos = ptr - merge_names->buf + 1;
1091 else
1092 npos = merge_names->len;
1093
1094 if (npos - pos < 40 + 2 ||
1095 get_sha1_hex(merge_names->buf + pos, sha1))
1096 commit = NULL; /* bad */
1097 else if (memcmp(merge_names->buf + pos + 40, "\t\t", 2))
1098 continue; /* not-for-merge */
1099 else {
1100 char saved = merge_names->buf[pos + 40];
1101 merge_names->buf[pos + 40] = '\0';
1102 commit = get_merge_parent(merge_names->buf + pos);
1103 merge_names->buf[pos + 40] = saved;
1104 }
1105 if (!commit) {
1106 if (ptr)
1107 *ptr = '\0';
1108 die("not something we can merge in %s: %s",
1109 filename, merge_names->buf + pos);
1110 }
1111 remotes = &commit_list_insert(commit, remotes)->next;
1112 }
1113
1114 if (merge_names == &fetch_head_file)
1115 strbuf_release(&fetch_head_file);
1116 }
1117
1118 static struct commit_list *collect_parents(struct commit *head_commit,
1119 int *head_subsumed,
1120 int argc, const char **argv,
1121 struct strbuf *merge_msg)
1122 {
1123 int i;
1124 struct commit_list *remoteheads = NULL;
1125 struct commit_list **remotes = &remoteheads;
1126 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1127
1128 if (merge_msg && (!have_message || shortlog_len))
1129 autogen = &merge_names;
1130
1131 if (head_commit)
1132 remotes = &commit_list_insert(head_commit, remotes)->next;
1133
1134 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1135 handle_fetch_head(remotes, autogen);
1136 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1137 } else {
1138 for (i = 0; i < argc; i++) {
1139 struct commit *commit = get_merge_parent(argv[i]);
1140 if (!commit)
1141 help_unknown_ref(argv[i], "merge",
1142 "not something we can merge");
1143 remotes = &commit_list_insert(commit, remotes)->next;
1144 }
1145 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1146 if (autogen) {
1147 struct commit_list *p;
1148 for (p = remoteheads; p; p = p->next)
1149 merge_name(merge_remote_util(p->item)->name, autogen);
1150 }
1151 }
1152
1153 if (autogen) {
1154 prepare_merge_message(autogen, merge_msg);
1155 strbuf_release(autogen);
1156 }
1157
1158 return remoteheads;
1159 }
1160
1161 int cmd_merge(int argc, const char **argv, const char *prefix)
1162 {
1163 unsigned char result_tree[20];
1164 unsigned char stash[20];
1165 unsigned char head_sha1[20];
1166 struct commit *head_commit;
1167 struct strbuf buf = STRBUF_INIT;
1168 const char *head_arg;
1169 int flag, i, ret = 0, head_subsumed;
1170 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1171 struct commit_list *common = NULL;
1172 const char *best_strategy = NULL, *wt_strategy = NULL;
1173 struct commit_list *remoteheads, *p;
1174 void *branch_to_free;
1175
1176 if (argc == 2 && !strcmp(argv[1], "-h"))
1177 usage_with_options(builtin_merge_usage, builtin_merge_options);
1178
1179 /*
1180 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1181 * current branch.
1182 */
1183 branch = branch_to_free = resolve_refdup("HEAD", 0, head_sha1, &flag);
1184 if (branch && starts_with(branch, "refs/heads/"))
1185 branch += 11;
1186 if (!branch || is_null_sha1(head_sha1))
1187 head_commit = NULL;
1188 else
1189 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1190
1191 git_config(git_merge_config, NULL);
1192
1193 if (branch_mergeoptions)
1194 parse_branch_merge_options(branch_mergeoptions);
1195 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1196 builtin_merge_usage, 0);
1197 if (shortlog_len < 0)
1198 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1199
1200 if (verbosity < 0 && show_progress == -1)
1201 show_progress = 0;
1202
1203 if (abort_current_merge) {
1204 int nargc = 2;
1205 const char *nargv[] = {"reset", "--merge", NULL};
1206
1207 if (!file_exists(git_path_merge_head()))
1208 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1209
1210 /* Invoke 'git reset --merge' */
1211 ret = cmd_reset(nargc, nargv, prefix);
1212 goto done;
1213 }
1214
1215 if (read_cache_unmerged())
1216 die_resolve_conflict("merge");
1217
1218 if (file_exists(git_path_merge_head())) {
1219 /*
1220 * There is no unmerged entry, don't advise 'git
1221 * add/rm <file>', just 'git commit'.
1222 */
1223 if (advice_resolve_conflict)
1224 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1225 "Please, commit your changes before you merge."));
1226 else
1227 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1228 }
1229 if (file_exists(git_path_cherry_pick_head())) {
1230 if (advice_resolve_conflict)
1231 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1232 "Please, commit your changes before you merge."));
1233 else
1234 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1235 }
1236 resolve_undo_clear();
1237
1238 if (verbosity < 0)
1239 show_diffstat = 0;
1240
1241 if (squash) {
1242 if (fast_forward == FF_NO)
1243 die(_("You cannot combine --squash with --no-ff."));
1244 option_commit = 0;
1245 }
1246
1247 if (!argc) {
1248 if (default_to_upstream)
1249 argc = setup_with_upstream(&argv);
1250 else
1251 die(_("No commit specified and merge.defaultToUpstream not set."));
1252 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1253 argv[0] = "@{-1}";
1254 }
1255
1256 if (!argc)
1257 usage_with_options(builtin_merge_usage,
1258 builtin_merge_options);
1259
1260 if (!head_commit) {
1261 struct commit *remote_head;
1262 /*
1263 * If the merged head is a valid one there is no reason
1264 * to forbid "git merge" into a branch yet to be born.
1265 * We do the same for "git pull".
1266 */
1267 if (squash)
1268 die(_("Squash commit into empty head not supported yet"));
1269 if (fast_forward == FF_NO)
1270 die(_("Non-fast-forward commit does not make sense into "
1271 "an empty head"));
1272 remoteheads = collect_parents(head_commit, &head_subsumed,
1273 argc, argv, NULL);
1274 remote_head = remoteheads->item;
1275 if (!remote_head)
1276 die(_("%s - not something we can merge"), argv[0]);
1277 if (remoteheads->next)
1278 die(_("Can merge only exactly one commit into empty head"));
1279 read_empty(remote_head->object.sha1, 0);
1280 update_ref("initial pull", "HEAD", remote_head->object.sha1,
1281 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1282 goto done;
1283 }
1284
1285 /*
1286 * This could be traditional "merge <msg> HEAD <commit>..." and
1287 * the way we can tell it is to see if the second token is HEAD,
1288 * but some people might have misused the interface and used a
1289 * commit-ish that is the same as HEAD there instead.
1290 * Traditional format never would have "-m" so it is an
1291 * additional safety measure to check for it.
1292 */
1293 if (!have_message &&
1294 is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
1295 warning("old-style 'git merge <msg> HEAD <commit>' is deprecated.");
1296 strbuf_addstr(&merge_msg, argv[0]);
1297 head_arg = argv[1];
1298 argv += 2;
1299 argc -= 2;
1300 remoteheads = collect_parents(head_commit, &head_subsumed,
1301 argc, argv, NULL);
1302 } else {
1303 /* We are invoked directly as the first-class UI. */
1304 head_arg = "HEAD";
1305
1306 /*
1307 * All the rest are the commits being merged; prepare
1308 * the standard merge summary message to be appended
1309 * to the given message.
1310 */
1311 remoteheads = collect_parents(head_commit, &head_subsumed,
1312 argc, argv, &merge_msg);
1313 }
1314
1315 if (!head_commit || !argc)
1316 usage_with_options(builtin_merge_usage,
1317 builtin_merge_options);
1318
1319 if (verify_signatures) {
1320 for (p = remoteheads; p; p = p->next) {
1321 struct commit *commit = p->item;
1322 char hex[GIT_SHA1_HEXSZ + 1];
1323 struct signature_check signature_check;
1324 memset(&signature_check, 0, sizeof(signature_check));
1325
1326 check_commit_signature(commit, &signature_check);
1327
1328 find_unique_abbrev_r(hex, commit->object.sha1, DEFAULT_ABBREV);
1329 switch (signature_check.result) {
1330 case 'G':
1331 break;
1332 case 'U':
1333 die(_("Commit %s has an untrusted GPG signature, "
1334 "allegedly by %s."), hex, signature_check.signer);
1335 case 'B':
1336 die(_("Commit %s has a bad GPG signature "
1337 "allegedly by %s."), hex, signature_check.signer);
1338 default: /* 'N' */
1339 die(_("Commit %s does not have a GPG signature."), hex);
1340 }
1341 if (verbosity >= 0 && signature_check.result == 'G')
1342 printf(_("Commit %s has a good GPG signature by %s\n"),
1343 hex, signature_check.signer);
1344
1345 signature_check_clear(&signature_check);
1346 }
1347 }
1348
1349 strbuf_addstr(&buf, "merge");
1350 for (p = remoteheads; p; p = p->next)
1351 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1352 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1353 strbuf_reset(&buf);
1354
1355 for (p = remoteheads; p; p = p->next) {
1356 struct commit *commit = p->item;
1357 strbuf_addf(&buf, "GITHEAD_%s",
1358 sha1_to_hex(commit->object.sha1));
1359 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1360 strbuf_reset(&buf);
1361 if (fast_forward != FF_ONLY &&
1362 merge_remote_util(commit) &&
1363 merge_remote_util(commit)->obj &&
1364 merge_remote_util(commit)->obj->type == OBJ_TAG)
1365 fast_forward = FF_NO;
1366 }
1367
1368 if (option_edit < 0)
1369 option_edit = default_edit_option();
1370
1371 if (!use_strategies) {
1372 if (!remoteheads)
1373 ; /* already up-to-date */
1374 else if (!remoteheads->next)
1375 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1376 else
1377 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1378 }
1379
1380 for (i = 0; i < use_strategies_nr; i++) {
1381 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1382 fast_forward = FF_NO;
1383 if (use_strategies[i]->attr & NO_TRIVIAL)
1384 allow_trivial = 0;
1385 }
1386
1387 if (!remoteheads)
1388 ; /* already up-to-date */
1389 else if (!remoteheads->next)
1390 common = get_merge_bases(head_commit, remoteheads->item);
1391 else {
1392 struct commit_list *list = remoteheads;
1393 commit_list_insert(head_commit, &list);
1394 common = get_octopus_merge_bases(list);
1395 free(list);
1396 }
1397
1398 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
1399 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1400
1401 if (remoteheads && !common)
1402 ; /* No common ancestors found. We need a real merge. */
1403 else if (!remoteheads ||
1404 (!remoteheads->next && !common->next &&
1405 common->item == remoteheads->item)) {
1406 /*
1407 * If head can reach all the merge then we are up to date.
1408 * but first the most common case of merging one remote.
1409 */
1410 finish_up_to_date("Already up-to-date.");
1411 goto done;
1412 } else if (fast_forward != FF_NO && !remoteheads->next &&
1413 !common->next &&
1414 !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
1415 /* Again the most common case of merging one remote. */
1416 struct strbuf msg = STRBUF_INIT;
1417 struct commit *commit;
1418
1419 if (verbosity >= 0) {
1420 char from[GIT_SHA1_HEXSZ + 1], to[GIT_SHA1_HEXSZ + 1];
1421 find_unique_abbrev_r(from, head_commit->object.sha1,
1422 DEFAULT_ABBREV);
1423 find_unique_abbrev_r(to, remoteheads->item->object.sha1,
1424 DEFAULT_ABBREV);
1425 printf(_("Updating %s..%s\n"), from, to);
1426 }
1427 strbuf_addstr(&msg, "Fast-forward");
1428 if (have_message)
1429 strbuf_addstr(&msg,
1430 " (no commit created; -m option ignored)");
1431 commit = remoteheads->item;
1432 if (!commit) {
1433 ret = 1;
1434 goto done;
1435 }
1436
1437 if (checkout_fast_forward(head_commit->object.sha1,
1438 commit->object.sha1,
1439 overwrite_ignore)) {
1440 ret = 1;
1441 goto done;
1442 }
1443
1444 finish(head_commit, remoteheads, commit->object.sha1, msg.buf);
1445 drop_save();
1446 goto done;
1447 } else if (!remoteheads->next && common->next)
1448 ;
1449 /*
1450 * We are not doing octopus and not fast-forward. Need
1451 * a real merge.
1452 */
1453 else if (!remoteheads->next && !common->next && option_commit) {
1454 /*
1455 * We are not doing octopus, not fast-forward, and have
1456 * only one common.
1457 */
1458 refresh_cache(REFRESH_QUIET);
1459 if (allow_trivial && fast_forward != FF_ONLY) {
1460 /* See if it is really trivial. */
1461 git_committer_info(IDENT_STRICT);
1462 printf(_("Trying really trivial in-index merge...\n"));
1463 if (!read_tree_trivial(common->item->object.sha1,
1464 head_commit->object.sha1,
1465 remoteheads->item->object.sha1)) {
1466 ret = merge_trivial(head_commit, remoteheads);
1467 goto done;
1468 }
1469 printf(_("Nope.\n"));
1470 }
1471 } else {
1472 /*
1473 * An octopus. If we can reach all the remote we are up
1474 * to date.
1475 */
1476 int up_to_date = 1;
1477 struct commit_list *j;
1478
1479 for (j = remoteheads; j; j = j->next) {
1480 struct commit_list *common_one;
1481
1482 /*
1483 * Here we *have* to calculate the individual
1484 * merge_bases again, otherwise "git merge HEAD^
1485 * HEAD^^" would be missed.
1486 */
1487 common_one = get_merge_bases(head_commit, j->item);
1488 if (hashcmp(common_one->item->object.sha1,
1489 j->item->object.sha1)) {
1490 up_to_date = 0;
1491 break;
1492 }
1493 }
1494 if (up_to_date) {
1495 finish_up_to_date("Already up-to-date. Yeeah!");
1496 goto done;
1497 }
1498 }
1499
1500 if (fast_forward == FF_ONLY)
1501 die(_("Not possible to fast-forward, aborting."));
1502
1503 /* We are going to make a new commit. */
1504 git_committer_info(IDENT_STRICT);
1505
1506 /*
1507 * At this point, we need a real merge. No matter what strategy
1508 * we use, it would operate on the index, possibly affecting the
1509 * working tree, and when resolved cleanly, have the desired
1510 * tree in the index -- this means that the index must be in
1511 * sync with the head commit. The strategies are responsible
1512 * to ensure this.
1513 */
1514 if (use_strategies_nr == 1 ||
1515 /*
1516 * Stash away the local changes so that we can try more than one.
1517 */
1518 save_state(stash))
1519 hashcpy(stash, null_sha1);
1520
1521 for (i = 0; i < use_strategies_nr; i++) {
1522 int ret;
1523 if (i) {
1524 printf(_("Rewinding the tree to pristine...\n"));
1525 restore_state(head_commit->object.sha1, stash);
1526 }
1527 if (use_strategies_nr != 1)
1528 printf(_("Trying merge strategy %s...\n"),
1529 use_strategies[i]->name);
1530 /*
1531 * Remember which strategy left the state in the working
1532 * tree.
1533 */
1534 wt_strategy = use_strategies[i]->name;
1535
1536 ret = try_merge_strategy(use_strategies[i]->name,
1537 common, remoteheads,
1538 head_commit, head_arg);
1539 if (!option_commit && !ret) {
1540 merge_was_ok = 1;
1541 /*
1542 * This is necessary here just to avoid writing
1543 * the tree, but later we will *not* exit with
1544 * status code 1 because merge_was_ok is set.
1545 */
1546 ret = 1;
1547 }
1548
1549 if (ret) {
1550 /*
1551 * The backend exits with 1 when conflicts are
1552 * left to be resolved, with 2 when it does not
1553 * handle the given merge at all.
1554 */
1555 if (ret == 1) {
1556 int cnt = evaluate_result();
1557
1558 if (best_cnt <= 0 || cnt <= best_cnt) {
1559 best_strategy = use_strategies[i]->name;
1560 best_cnt = cnt;
1561 }
1562 }
1563 if (merge_was_ok)
1564 break;
1565 else
1566 continue;
1567 }
1568
1569 /* Automerge succeeded. */
1570 write_tree_trivial(result_tree);
1571 automerge_was_ok = 1;
1572 break;
1573 }
1574
1575 /*
1576 * If we have a resulting tree, that means the strategy module
1577 * auto resolved the merge cleanly.
1578 */
1579 if (automerge_was_ok) {
1580 ret = finish_automerge(head_commit, head_subsumed,
1581 common, remoteheads,
1582 result_tree, wt_strategy);
1583 goto done;
1584 }
1585
1586 /*
1587 * Pick the result from the best strategy and have the user fix
1588 * it up.
1589 */
1590 if (!best_strategy) {
1591 restore_state(head_commit->object.sha1, stash);
1592 if (use_strategies_nr > 1)
1593 fprintf(stderr,
1594 _("No merge strategy handled the merge.\n"));
1595 else
1596 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1597 use_strategies[0]->name);
1598 ret = 2;
1599 goto done;
1600 } else if (best_strategy == wt_strategy)
1601 ; /* We already have its result in the working tree. */
1602 else {
1603 printf(_("Rewinding the tree to pristine...\n"));
1604 restore_state(head_commit->object.sha1, stash);
1605 printf(_("Using the %s to prepare resolving by hand.\n"),
1606 best_strategy);
1607 try_merge_strategy(best_strategy, common, remoteheads,
1608 head_commit, head_arg);
1609 }
1610
1611 if (squash)
1612 finish(head_commit, remoteheads, NULL, NULL);
1613 else
1614 write_merge_state(remoteheads);
1615
1616 if (merge_was_ok)
1617 fprintf(stderr, _("Automatic merge went well; "
1618 "stopped before committing as requested\n"));
1619 else
1620 ret = suggest_conflicts();
1621
1622 done:
1623 free(branch_to_free);
1624 return ret;
1625 }