Merge branch 'bc/hash-independent-tests'
[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 "config.h"
11 #include "parse-options.h"
12 #include "builtin.h"
13 #include "lockfile.h"
14 #include "run-command.h"
15 #include "diff.h"
16 #include "refs.h"
17 #include "refspec.h"
18 #include "commit.h"
19 #include "diffcore.h"
20 #include "revision.h"
21 #include "unpack-trees.h"
22 #include "cache-tree.h"
23 #include "dir.h"
24 #include "utf8.h"
25 #include "log-tree.h"
26 #include "color.h"
27 #include "rerere.h"
28 #include "help.h"
29 #include "merge-recursive.h"
30 #include "resolve-undo.h"
31 #include "remote.h"
32 #include "fmt-merge-msg.h"
33 #include "gpg-interface.h"
34 #include "sequencer.h"
35 #include "string-list.h"
36 #include "packfile.h"
37 #include "tag.h"
38
39 #define DEFAULT_TWOHEAD (1<<0)
40 #define DEFAULT_OCTOPUS (1<<1)
41 #define NO_FAST_FORWARD (1<<2)
42 #define NO_TRIVIAL (1<<3)
43
44 struct strategy {
45 const char *name;
46 unsigned attr;
47 };
48
49 static const char * const builtin_merge_usage[] = {
50 N_("git merge [<options>] [<commit>...]"),
51 N_("git merge --abort"),
52 N_("git merge --continue"),
53 NULL
54 };
55
56 static int show_diffstat = 1, shortlog_len = -1, squash;
57 static int option_commit = 1;
58 static int option_edit = -1;
59 static int allow_trivial = 1, have_message, verify_signatures;
60 static int overwrite_ignore = 1;
61 static struct strbuf merge_msg = STRBUF_INIT;
62 static struct strategy **use_strategies;
63 static size_t use_strategies_nr, use_strategies_alloc;
64 static const char **xopts;
65 static size_t xopts_nr, xopts_alloc;
66 static const char *branch;
67 static char *branch_mergeoptions;
68 static int option_renormalize;
69 static int verbosity;
70 static int allow_rerere_auto;
71 static int abort_current_merge;
72 static int continue_current_merge;
73 static int allow_unrelated_histories;
74 static int show_progress = -1;
75 static int default_to_upstream = 1;
76 static int signoff;
77 static const char *sign_commit;
78 static int verify_msg = 1;
79
80 static struct strategy all_strategy[] = {
81 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
82 { "octopus", DEFAULT_OCTOPUS },
83 { "resolve", 0 },
84 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
85 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
86 };
87
88 static const char *pull_twohead, *pull_octopus;
89
90 enum ff_type {
91 FF_NO,
92 FF_ALLOW,
93 FF_ONLY
94 };
95
96 static enum ff_type fast_forward = FF_ALLOW;
97
98 static int option_parse_message(const struct option *opt,
99 const char *arg, int unset)
100 {
101 struct strbuf *buf = opt->value;
102
103 if (unset)
104 strbuf_setlen(buf, 0);
105 else if (arg) {
106 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
107 have_message = 1;
108 } else
109 return error(_("switch `m' requires a value"));
110 return 0;
111 }
112
113 static struct strategy *get_strategy(const char *name)
114 {
115 int i;
116 struct strategy *ret;
117 static struct cmdnames main_cmds, other_cmds;
118 static int loaded;
119
120 if (!name)
121 return NULL;
122
123 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
124 if (!strcmp(name, all_strategy[i].name))
125 return &all_strategy[i];
126
127 if (!loaded) {
128 struct cmdnames not_strategies;
129 loaded = 1;
130
131 memset(&not_strategies, 0, sizeof(struct cmdnames));
132 load_command_list("git-merge-", &main_cmds, &other_cmds);
133 for (i = 0; i < main_cmds.cnt; i++) {
134 int j, found = 0;
135 struct cmdname *ent = main_cmds.names[i];
136 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
137 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
138 && !all_strategy[j].name[ent->len])
139 found = 1;
140 if (!found)
141 add_cmdname(&not_strategies, ent->name, ent->len);
142 }
143 exclude_cmds(&main_cmds, &not_strategies);
144 }
145 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
146 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
147 fprintf(stderr, _("Available strategies are:"));
148 for (i = 0; i < main_cmds.cnt; i++)
149 fprintf(stderr, " %s", main_cmds.names[i]->name);
150 fprintf(stderr, ".\n");
151 if (other_cmds.cnt) {
152 fprintf(stderr, _("Available custom strategies are:"));
153 for (i = 0; i < other_cmds.cnt; i++)
154 fprintf(stderr, " %s", other_cmds.names[i]->name);
155 fprintf(stderr, ".\n");
156 }
157 exit(1);
158 }
159
160 ret = xcalloc(1, sizeof(struct strategy));
161 ret->name = xstrdup(name);
162 ret->attr = NO_TRIVIAL;
163 return ret;
164 }
165
166 static void append_strategy(struct strategy *s)
167 {
168 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
169 use_strategies[use_strategies_nr++] = s;
170 }
171
172 static int option_parse_strategy(const struct option *opt,
173 const char *name, int unset)
174 {
175 if (unset)
176 return 0;
177
178 append_strategy(get_strategy(name));
179 return 0;
180 }
181
182 static int option_parse_x(const struct option *opt,
183 const char *arg, int unset)
184 {
185 if (unset)
186 return 0;
187
188 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
189 xopts[xopts_nr++] = xstrdup(arg);
190 return 0;
191 }
192
193 static int option_parse_n(const struct option *opt,
194 const char *arg, int unset)
195 {
196 show_diffstat = unset;
197 return 0;
198 }
199
200 static struct option builtin_merge_options[] = {
201 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
202 N_("do not show a diffstat at the end of the merge"),
203 PARSE_OPT_NOARG, option_parse_n },
204 OPT_BOOL(0, "stat", &show_diffstat,
205 N_("show a diffstat at the end of the merge")),
206 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
207 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
208 N_("add (at most <n>) entries from shortlog to merge commit message"),
209 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
210 OPT_BOOL(0, "squash", &squash,
211 N_("create a single commit instead of doing a merge")),
212 OPT_BOOL(0, "commit", &option_commit,
213 N_("perform a commit if the merge succeeds (default)")),
214 OPT_BOOL('e', "edit", &option_edit,
215 N_("edit message before committing")),
216 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
217 { OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
218 N_("abort if fast-forward is not possible"),
219 PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
220 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
221 OPT_BOOL(0, "verify-signatures", &verify_signatures,
222 N_("verify that the named commit has a valid GPG signature")),
223 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
224 N_("merge strategy to use"), option_parse_strategy),
225 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
226 N_("option for selected merge strategy"), option_parse_x),
227 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
228 N_("merge commit message (for a non-fast-forward merge)"),
229 option_parse_message),
230 OPT__VERBOSITY(&verbosity),
231 OPT_BOOL(0, "abort", &abort_current_merge,
232 N_("abort the current in-progress merge")),
233 OPT_BOOL(0, "continue", &continue_current_merge,
234 N_("continue the current in-progress merge")),
235 OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
236 N_("allow merging unrelated histories")),
237 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
238 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
239 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
240 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
241 OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
242 OPT_BOOL(0, "verify", &verify_msg, N_("verify commit-msg hook")),
243 OPT_END()
244 };
245
246 /* Cleans up metadata that is uninteresting after a succeeded merge. */
247 static void drop_save(void)
248 {
249 unlink(git_path_merge_head());
250 unlink(git_path_merge_msg());
251 unlink(git_path_merge_mode());
252 }
253
254 static int save_state(struct object_id *stash)
255 {
256 int len;
257 struct child_process cp = CHILD_PROCESS_INIT;
258 struct strbuf buffer = STRBUF_INIT;
259 const char *argv[] = {"stash", "create", NULL};
260 int rc = -1;
261
262 cp.argv = argv;
263 cp.out = -1;
264 cp.git_cmd = 1;
265
266 if (start_command(&cp))
267 die(_("could not run stash."));
268 len = strbuf_read(&buffer, cp.out, 1024);
269 close(cp.out);
270
271 if (finish_command(&cp) || len < 0)
272 die(_("stash failed"));
273 else if (!len) /* no changes */
274 goto out;
275 strbuf_setlen(&buffer, buffer.len-1);
276 if (get_oid(buffer.buf, stash))
277 die(_("not a valid object: %s"), buffer.buf);
278 rc = 0;
279 out:
280 strbuf_release(&buffer);
281 return rc;
282 }
283
284 static void read_empty(const struct object_id *oid, int verbose)
285 {
286 int i = 0;
287 const char *args[7];
288
289 args[i++] = "read-tree";
290 if (verbose)
291 args[i++] = "-v";
292 args[i++] = "-m";
293 args[i++] = "-u";
294 args[i++] = empty_tree_oid_hex();
295 args[i++] = oid_to_hex(oid);
296 args[i] = NULL;
297
298 if (run_command_v_opt(args, RUN_GIT_CMD))
299 die(_("read-tree failed"));
300 }
301
302 static void reset_hard(const struct object_id *oid, int verbose)
303 {
304 int i = 0;
305 const char *args[6];
306
307 args[i++] = "read-tree";
308 if (verbose)
309 args[i++] = "-v";
310 args[i++] = "--reset";
311 args[i++] = "-u";
312 args[i++] = oid_to_hex(oid);
313 args[i] = NULL;
314
315 if (run_command_v_opt(args, RUN_GIT_CMD))
316 die(_("read-tree failed"));
317 }
318
319 static void restore_state(const struct object_id *head,
320 const struct object_id *stash)
321 {
322 struct strbuf sb = STRBUF_INIT;
323 const char *args[] = { "stash", "apply", NULL, NULL };
324
325 if (is_null_oid(stash))
326 return;
327
328 reset_hard(head, 1);
329
330 args[2] = oid_to_hex(stash);
331
332 /*
333 * It is OK to ignore error here, for example when there was
334 * nothing to restore.
335 */
336 run_command_v_opt(args, RUN_GIT_CMD);
337
338 strbuf_release(&sb);
339 refresh_cache(REFRESH_QUIET);
340 }
341
342 /* This is called when no merge was necessary. */
343 static void finish_up_to_date(const char *msg)
344 {
345 if (verbosity >= 0)
346 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
347 drop_save();
348 }
349
350 static void squash_message(struct commit *commit, struct commit_list *remoteheads)
351 {
352 struct rev_info rev;
353 struct strbuf out = STRBUF_INIT;
354 struct commit_list *j;
355 struct pretty_print_context ctx = {0};
356
357 printf(_("Squash commit -- not updating HEAD\n"));
358
359 init_revisions(&rev, NULL);
360 rev.ignore_merges = 1;
361 rev.commit_format = CMIT_FMT_MEDIUM;
362
363 commit->object.flags |= UNINTERESTING;
364 add_pending_object(&rev, &commit->object, NULL);
365
366 for (j = remoteheads; j; j = j->next)
367 add_pending_object(&rev, &j->item->object, NULL);
368
369 setup_revisions(0, NULL, &rev, NULL);
370 if (prepare_revision_walk(&rev))
371 die(_("revision walk setup failed"));
372
373 ctx.abbrev = rev.abbrev;
374 ctx.date_mode = rev.date_mode;
375 ctx.fmt = rev.commit_format;
376
377 strbuf_addstr(&out, "Squashed commit of the following:\n");
378 while ((commit = get_revision(&rev)) != NULL) {
379 strbuf_addch(&out, '\n');
380 strbuf_addf(&out, "commit %s\n",
381 oid_to_hex(&commit->object.oid));
382 pretty_print_commit(&ctx, commit, &out);
383 }
384 write_file_buf(git_path_squash_msg(), out.buf, out.len);
385 strbuf_release(&out);
386 }
387
388 static void finish(struct commit *head_commit,
389 struct commit_list *remoteheads,
390 const struct object_id *new_head, const char *msg)
391 {
392 struct strbuf reflog_message = STRBUF_INIT;
393 const struct object_id *head = &head_commit->object.oid;
394
395 if (!msg)
396 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
397 else {
398 if (verbosity >= 0)
399 printf("%s\n", msg);
400 strbuf_addf(&reflog_message, "%s: %s",
401 getenv("GIT_REFLOG_ACTION"), msg);
402 }
403 if (squash) {
404 squash_message(head_commit, remoteheads);
405 } else {
406 if (verbosity >= 0 && !merge_msg.len)
407 printf(_("No merge message -- not updating HEAD\n"));
408 else {
409 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
410 update_ref(reflog_message.buf, "HEAD", new_head, head,
411 0, UPDATE_REFS_DIE_ON_ERR);
412 /*
413 * We ignore errors in 'gc --auto', since the
414 * user should see them.
415 */
416 close_all_packs(the_repository->objects);
417 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
418 }
419 }
420 if (new_head && show_diffstat) {
421 struct diff_options opts;
422 diff_setup(&opts);
423 opts.stat_width = -1; /* use full terminal width */
424 opts.stat_graph_width = -1; /* respect statGraphWidth config */
425 opts.output_format |=
426 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
427 opts.detect_rename = DIFF_DETECT_RENAME;
428 diff_setup_done(&opts);
429 diff_tree_oid(head, new_head, "", &opts);
430 diffcore_std(&opts);
431 diff_flush(&opts);
432 }
433
434 /* Run a post-merge hook */
435 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
436
437 strbuf_release(&reflog_message);
438 }
439
440 /* Get the name for the merge commit's message. */
441 static void merge_name(const char *remote, struct strbuf *msg)
442 {
443 struct commit *remote_head;
444 struct object_id branch_head;
445 struct strbuf buf = STRBUF_INIT;
446 struct strbuf bname = STRBUF_INIT;
447 const char *ptr;
448 char *found_ref;
449 int len, early;
450
451 strbuf_branchname(&bname, remote, 0);
452 remote = bname.buf;
453
454 oidclr(&branch_head);
455 remote_head = get_merge_parent(remote);
456 if (!remote_head)
457 die(_("'%s' does not point to a commit"), remote);
458
459 if (dwim_ref(remote, strlen(remote), &branch_head, &found_ref) > 0) {
460 if (starts_with(found_ref, "refs/heads/")) {
461 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
462 oid_to_hex(&branch_head), remote);
463 goto cleanup;
464 }
465 if (starts_with(found_ref, "refs/tags/")) {
466 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
467 oid_to_hex(&branch_head), remote);
468 goto cleanup;
469 }
470 if (starts_with(found_ref, "refs/remotes/")) {
471 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
472 oid_to_hex(&branch_head), remote);
473 goto cleanup;
474 }
475 }
476
477 /* See if remote matches <name>^^^.. or <name>~<number> */
478 for (len = 0, ptr = remote + strlen(remote);
479 remote < ptr && ptr[-1] == '^';
480 ptr--)
481 len++;
482 if (len)
483 early = 1;
484 else {
485 early = 0;
486 ptr = strrchr(remote, '~');
487 if (ptr) {
488 int seen_nonzero = 0;
489
490 len++; /* count ~ */
491 while (*++ptr && isdigit(*ptr)) {
492 seen_nonzero |= (*ptr != '0');
493 len++;
494 }
495 if (*ptr)
496 len = 0; /* not ...~<number> */
497 else if (seen_nonzero)
498 early = 1;
499 else if (len == 1)
500 early = 1; /* "name~" is "name~1"! */
501 }
502 }
503 if (len) {
504 struct strbuf truname = STRBUF_INIT;
505 strbuf_addf(&truname, "refs/heads/%s", remote);
506 strbuf_setlen(&truname, truname.len - len);
507 if (ref_exists(truname.buf)) {
508 strbuf_addf(msg,
509 "%s\t\tbranch '%s'%s of .\n",
510 oid_to_hex(&remote_head->object.oid),
511 truname.buf + 11,
512 (early ? " (early part)" : ""));
513 strbuf_release(&truname);
514 goto cleanup;
515 }
516 strbuf_release(&truname);
517 }
518
519 if (remote_head->util) {
520 struct merge_remote_desc *desc;
521 desc = merge_remote_util(remote_head);
522 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
523 strbuf_addf(msg, "%s\t\t%s '%s'\n",
524 oid_to_hex(&desc->obj->oid),
525 type_name(desc->obj->type),
526 remote);
527 goto cleanup;
528 }
529 }
530
531 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
532 oid_to_hex(&remote_head->object.oid), remote);
533 cleanup:
534 strbuf_release(&buf);
535 strbuf_release(&bname);
536 }
537
538 static void parse_branch_merge_options(char *bmo)
539 {
540 const char **argv;
541 int argc;
542
543 if (!bmo)
544 return;
545 argc = split_cmdline(bmo, &argv);
546 if (argc < 0)
547 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
548 split_cmdline_strerror(argc));
549 REALLOC_ARRAY(argv, argc + 2);
550 MOVE_ARRAY(argv + 1, argv, argc + 1);
551 argc++;
552 argv[0] = "branch.*.mergeoptions";
553 parse_options(argc, argv, NULL, builtin_merge_options,
554 builtin_merge_usage, 0);
555 free(argv);
556 }
557
558 static int git_merge_config(const char *k, const char *v, void *cb)
559 {
560 int status;
561
562 if (branch && starts_with(k, "branch.") &&
563 starts_with(k + 7, branch) &&
564 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
565 free(branch_mergeoptions);
566 branch_mergeoptions = xstrdup(v);
567 return 0;
568 }
569
570 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
571 show_diffstat = git_config_bool(k, v);
572 else if (!strcmp(k, "merge.verifysignatures"))
573 verify_signatures = git_config_bool(k, v);
574 else if (!strcmp(k, "pull.twohead"))
575 return git_config_string(&pull_twohead, k, v);
576 else if (!strcmp(k, "pull.octopus"))
577 return git_config_string(&pull_octopus, k, v);
578 else if (!strcmp(k, "merge.renormalize"))
579 option_renormalize = git_config_bool(k, v);
580 else if (!strcmp(k, "merge.ff")) {
581 int boolval = git_parse_maybe_bool(v);
582 if (0 <= boolval) {
583 fast_forward = boolval ? FF_ALLOW : FF_NO;
584 } else if (v && !strcmp(v, "only")) {
585 fast_forward = FF_ONLY;
586 } /* do not barf on values from future versions of git */
587 return 0;
588 } else if (!strcmp(k, "merge.defaulttoupstream")) {
589 default_to_upstream = git_config_bool(k, v);
590 return 0;
591 } else if (!strcmp(k, "commit.gpgsign")) {
592 sign_commit = git_config_bool(k, v) ? "" : NULL;
593 return 0;
594 }
595
596 status = fmt_merge_msg_config(k, v, cb);
597 if (status)
598 return status;
599 status = git_gpg_config(k, v, NULL);
600 if (status)
601 return status;
602 return git_diff_ui_config(k, v, cb);
603 }
604
605 static int read_tree_trivial(struct object_id *common, struct object_id *head,
606 struct object_id *one)
607 {
608 int i, nr_trees = 0;
609 struct tree *trees[MAX_UNPACK_TREES];
610 struct tree_desc t[MAX_UNPACK_TREES];
611 struct unpack_trees_options opts;
612
613 memset(&opts, 0, sizeof(opts));
614 opts.head_idx = 2;
615 opts.src_index = &the_index;
616 opts.dst_index = &the_index;
617 opts.update = 1;
618 opts.verbose_update = 1;
619 opts.trivial_merges_only = 1;
620 opts.merge = 1;
621 trees[nr_trees] = parse_tree_indirect(common);
622 if (!trees[nr_trees++])
623 return -1;
624 trees[nr_trees] = parse_tree_indirect(head);
625 if (!trees[nr_trees++])
626 return -1;
627 trees[nr_trees] = parse_tree_indirect(one);
628 if (!trees[nr_trees++])
629 return -1;
630 opts.fn = threeway_merge;
631 cache_tree_free(&active_cache_tree);
632 for (i = 0; i < nr_trees; i++) {
633 parse_tree(trees[i]);
634 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
635 }
636 if (unpack_trees(nr_trees, t, &opts))
637 return -1;
638 return 0;
639 }
640
641 static void write_tree_trivial(struct object_id *oid)
642 {
643 if (write_cache_as_tree(oid, 0, NULL))
644 die(_("git write-tree failed to write a tree"));
645 }
646
647 static int try_merge_strategy(const char *strategy, struct commit_list *common,
648 struct commit_list *remoteheads,
649 struct commit *head)
650 {
651 struct lock_file lock = LOCK_INIT;
652 const char *head_arg = "HEAD";
653
654 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
655 refresh_cache(REFRESH_QUIET);
656 if (write_locked_index(&the_index, &lock,
657 COMMIT_LOCK | SKIP_IF_UNCHANGED))
658 return error(_("Unable to write index."));
659
660 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
661 int clean, x;
662 struct commit *result;
663 struct commit_list *reversed = NULL;
664 struct merge_options o;
665 struct commit_list *j;
666
667 if (remoteheads->next) {
668 error(_("Not handling anything other than two heads merge."));
669 return 2;
670 }
671
672 init_merge_options(&o);
673 if (!strcmp(strategy, "subtree"))
674 o.subtree_shift = "";
675
676 o.renormalize = option_renormalize;
677 o.show_rename_progress =
678 show_progress == -1 ? isatty(2) : show_progress;
679
680 for (x = 0; x < xopts_nr; x++)
681 if (parse_merge_opt(&o, xopts[x]))
682 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
683
684 o.branch1 = head_arg;
685 o.branch2 = merge_remote_util(remoteheads->item)->name;
686
687 for (j = common; j; j = j->next)
688 commit_list_insert(j->item, &reversed);
689
690 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
691 clean = merge_recursive(&o, head,
692 remoteheads->item, reversed, &result);
693 if (clean < 0)
694 exit(128);
695 if (write_locked_index(&the_index, &lock,
696 COMMIT_LOCK | SKIP_IF_UNCHANGED))
697 die (_("unable to write %s"), get_index_file());
698 return clean ? 0 : 1;
699 } else {
700 return try_merge_command(strategy, xopts_nr, xopts,
701 common, head_arg, remoteheads);
702 }
703 }
704
705 static void count_diff_files(struct diff_queue_struct *q,
706 struct diff_options *opt, void *data)
707 {
708 int *count = data;
709
710 (*count) += q->nr;
711 }
712
713 static int count_unmerged_entries(void)
714 {
715 int i, ret = 0;
716
717 for (i = 0; i < active_nr; i++)
718 if (ce_stage(active_cache[i]))
719 ret++;
720
721 return ret;
722 }
723
724 static void add_strategies(const char *string, unsigned attr)
725 {
726 int i;
727
728 if (string) {
729 struct string_list list = STRING_LIST_INIT_DUP;
730 struct string_list_item *item;
731 string_list_split(&list, string, ' ', -1);
732 for_each_string_list_item(item, &list)
733 append_strategy(get_strategy(item->string));
734 string_list_clear(&list, 0);
735 return;
736 }
737 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
738 if (all_strategy[i].attr & attr)
739 append_strategy(&all_strategy[i]);
740
741 }
742
743 static void read_merge_msg(struct strbuf *msg)
744 {
745 const char *filename = git_path_merge_msg();
746 strbuf_reset(msg);
747 if (strbuf_read_file(msg, filename, 0) < 0)
748 die_errno(_("Could not read from '%s'"), filename);
749 }
750
751 static void write_merge_state(struct commit_list *);
752 static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
753 {
754 if (err_msg)
755 error("%s", err_msg);
756 fprintf(stderr,
757 _("Not committing merge; use 'git commit' to complete the merge.\n"));
758 write_merge_state(remoteheads);
759 exit(1);
760 }
761
762 static const char merge_editor_comment[] =
763 N_("Please enter a commit message to explain why this merge is necessary,\n"
764 "especially if it merges an updated upstream into a topic branch.\n"
765 "\n"
766 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
767 "the commit.\n");
768
769 static void write_merge_heads(struct commit_list *);
770 static void prepare_to_commit(struct commit_list *remoteheads)
771 {
772 struct strbuf msg = STRBUF_INIT;
773 strbuf_addbuf(&msg, &merge_msg);
774 strbuf_addch(&msg, '\n');
775 if (squash)
776 BUG("the control must not reach here under --squash");
777 if (0 < option_edit)
778 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
779 if (signoff)
780 append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
781 write_merge_heads(remoteheads);
782 write_file_buf(git_path_merge_msg(), msg.buf, msg.len);
783 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
784 git_path_merge_msg(), "merge", NULL))
785 abort_commit(remoteheads, NULL);
786 if (0 < option_edit) {
787 if (launch_editor(git_path_merge_msg(), NULL, NULL))
788 abort_commit(remoteheads, NULL);
789 }
790
791 if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
792 "commit-msg",
793 git_path_merge_msg(), NULL))
794 abort_commit(remoteheads, NULL);
795
796 read_merge_msg(&msg);
797 strbuf_stripspace(&msg, 0 < option_edit);
798 if (!msg.len)
799 abort_commit(remoteheads, _("Empty commit message."));
800 strbuf_release(&merge_msg);
801 strbuf_addbuf(&merge_msg, &msg);
802 strbuf_release(&msg);
803 }
804
805 static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
806 {
807 struct object_id result_tree, result_commit;
808 struct commit_list *parents, **pptr = &parents;
809 struct lock_file lock = LOCK_INIT;
810
811 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
812 refresh_cache(REFRESH_QUIET);
813 if (write_locked_index(&the_index, &lock,
814 COMMIT_LOCK | SKIP_IF_UNCHANGED))
815 return error(_("Unable to write index."));
816
817 write_tree_trivial(&result_tree);
818 printf(_("Wonderful.\n"));
819 pptr = commit_list_append(head, pptr);
820 pptr = commit_list_append(remoteheads->item, pptr);
821 prepare_to_commit(remoteheads);
822 if (commit_tree(merge_msg.buf, merge_msg.len, &result_tree, parents,
823 &result_commit, NULL, sign_commit))
824 die(_("failed to write commit object"));
825 finish(head, remoteheads, &result_commit, "In-index merge");
826 drop_save();
827 return 0;
828 }
829
830 static int finish_automerge(struct commit *head,
831 int head_subsumed,
832 struct commit_list *common,
833 struct commit_list *remoteheads,
834 struct object_id *result_tree,
835 const char *wt_strategy)
836 {
837 struct commit_list *parents = NULL;
838 struct strbuf buf = STRBUF_INIT;
839 struct object_id result_commit;
840
841 free_commit_list(common);
842 parents = remoteheads;
843 if (!head_subsumed || fast_forward == FF_NO)
844 commit_list_insert(head, &parents);
845 strbuf_addch(&merge_msg, '\n');
846 prepare_to_commit(remoteheads);
847 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
848 &result_commit, NULL, sign_commit))
849 die(_("failed to write commit object"));
850 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
851 finish(head, remoteheads, &result_commit, buf.buf);
852 strbuf_release(&buf);
853 drop_save();
854 return 0;
855 }
856
857 static int suggest_conflicts(void)
858 {
859 const char *filename;
860 FILE *fp;
861 struct strbuf msgbuf = STRBUF_INIT;
862
863 filename = git_path_merge_msg();
864 fp = xfopen(filename, "a");
865
866 append_conflicts_hint(&msgbuf);
867 fputs(msgbuf.buf, fp);
868 strbuf_release(&msgbuf);
869 fclose(fp);
870 rerere(allow_rerere_auto);
871 printf(_("Automatic merge failed; "
872 "fix conflicts and then commit the result.\n"));
873 return 1;
874 }
875
876 static int evaluate_result(void)
877 {
878 int cnt = 0;
879 struct rev_info rev;
880
881 /* Check how many files differ. */
882 init_revisions(&rev, "");
883 setup_revisions(0, NULL, &rev, NULL);
884 rev.diffopt.output_format |=
885 DIFF_FORMAT_CALLBACK;
886 rev.diffopt.format_callback = count_diff_files;
887 rev.diffopt.format_callback_data = &cnt;
888 run_diff_files(&rev, 0);
889
890 /*
891 * Check how many unmerged entries are
892 * there.
893 */
894 cnt += count_unmerged_entries();
895
896 return cnt;
897 }
898
899 /*
900 * Pretend as if the user told us to merge with the remote-tracking
901 * branch we have for the upstream of the current branch
902 */
903 static int setup_with_upstream(const char ***argv)
904 {
905 struct branch *branch = branch_get(NULL);
906 int i;
907 const char **args;
908
909 if (!branch)
910 die(_("No current branch."));
911 if (!branch->remote_name)
912 die(_("No remote for the current branch."));
913 if (!branch->merge_nr)
914 die(_("No default upstream defined for the current branch."));
915
916 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
917 for (i = 0; i < branch->merge_nr; i++) {
918 if (!branch->merge[i]->dst)
919 die(_("No remote-tracking branch for %s from %s"),
920 branch->merge[i]->src, branch->remote_name);
921 args[i] = branch->merge[i]->dst;
922 }
923 args[i] = NULL;
924 *argv = args;
925 return i;
926 }
927
928 static void write_merge_heads(struct commit_list *remoteheads)
929 {
930 struct commit_list *j;
931 struct strbuf buf = STRBUF_INIT;
932
933 for (j = remoteheads; j; j = j->next) {
934 struct object_id *oid;
935 struct commit *c = j->item;
936 if (c->util && merge_remote_util(c)->obj) {
937 oid = &merge_remote_util(c)->obj->oid;
938 } else {
939 oid = &c->object.oid;
940 }
941 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
942 }
943 write_file_buf(git_path_merge_head(), buf.buf, buf.len);
944
945 strbuf_reset(&buf);
946 if (fast_forward == FF_NO)
947 strbuf_addstr(&buf, "no-ff");
948 write_file_buf(git_path_merge_mode(), buf.buf, buf.len);
949 strbuf_release(&buf);
950 }
951
952 static void write_merge_state(struct commit_list *remoteheads)
953 {
954 write_merge_heads(remoteheads);
955 strbuf_addch(&merge_msg, '\n');
956 write_file_buf(git_path_merge_msg(), merge_msg.buf, merge_msg.len);
957 }
958
959 static int default_edit_option(void)
960 {
961 static const char name[] = "GIT_MERGE_AUTOEDIT";
962 const char *e = getenv(name);
963 struct stat st_stdin, st_stdout;
964
965 if (have_message)
966 /* an explicit -m msg without --[no-]edit */
967 return 0;
968
969 if (e) {
970 int v = git_parse_maybe_bool(e);
971 if (v < 0)
972 die(_("Bad value '%s' in environment '%s'"), e, name);
973 return v;
974 }
975
976 /* Use editor if stdin and stdout are the same and is a tty */
977 return (!fstat(0, &st_stdin) &&
978 !fstat(1, &st_stdout) &&
979 isatty(0) && isatty(1) &&
980 st_stdin.st_dev == st_stdout.st_dev &&
981 st_stdin.st_ino == st_stdout.st_ino &&
982 st_stdin.st_mode == st_stdout.st_mode);
983 }
984
985 static struct commit_list *reduce_parents(struct commit *head_commit,
986 int *head_subsumed,
987 struct commit_list *remoteheads)
988 {
989 struct commit_list *parents, **remotes;
990
991 /*
992 * Is the current HEAD reachable from another commit being
993 * merged? If so we do not want to record it as a parent of
994 * the resulting merge, unless --no-ff is given. We will flip
995 * this variable to 0 when we find HEAD among the independent
996 * tips being merged.
997 */
998 *head_subsumed = 1;
999
1000 /* Find what parents to record by checking independent ones. */
1001 parents = reduce_heads(remoteheads);
1002 free_commit_list(remoteheads);
1003
1004 remoteheads = NULL;
1005 remotes = &remoteheads;
1006 while (parents) {
1007 struct commit *commit = pop_commit(&parents);
1008 if (commit == head_commit)
1009 *head_subsumed = 0;
1010 else
1011 remotes = &commit_list_insert(commit, remotes)->next;
1012 }
1013 return remoteheads;
1014 }
1015
1016 static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1017 {
1018 struct fmt_merge_msg_opts opts;
1019
1020 memset(&opts, 0, sizeof(opts));
1021 opts.add_title = !have_message;
1022 opts.shortlog_len = shortlog_len;
1023 opts.credit_people = (0 < option_edit);
1024
1025 fmt_merge_msg(merge_names, merge_msg, &opts);
1026 if (merge_msg->len)
1027 strbuf_setlen(merge_msg, merge_msg->len - 1);
1028 }
1029
1030 static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1031 {
1032 const char *filename;
1033 int fd, pos, npos;
1034 struct strbuf fetch_head_file = STRBUF_INIT;
1035
1036 if (!merge_names)
1037 merge_names = &fetch_head_file;
1038
1039 filename = git_path_fetch_head();
1040 fd = open(filename, O_RDONLY);
1041 if (fd < 0)
1042 die_errno(_("could not open '%s' for reading"), filename);
1043
1044 if (strbuf_read(merge_names, fd, 0) < 0)
1045 die_errno(_("could not read '%s'"), filename);
1046 if (close(fd) < 0)
1047 die_errno(_("could not close '%s'"), filename);
1048
1049 for (pos = 0; pos < merge_names->len; pos = npos) {
1050 struct object_id oid;
1051 char *ptr;
1052 struct commit *commit;
1053
1054 ptr = strchr(merge_names->buf + pos, '\n');
1055 if (ptr)
1056 npos = ptr - merge_names->buf + 1;
1057 else
1058 npos = merge_names->len;
1059
1060 if (npos - pos < GIT_SHA1_HEXSZ + 2 ||
1061 get_oid_hex(merge_names->buf + pos, &oid))
1062 commit = NULL; /* bad */
1063 else if (memcmp(merge_names->buf + pos + GIT_SHA1_HEXSZ, "\t\t", 2))
1064 continue; /* not-for-merge */
1065 else {
1066 char saved = merge_names->buf[pos + GIT_SHA1_HEXSZ];
1067 merge_names->buf[pos + GIT_SHA1_HEXSZ] = '\0';
1068 commit = get_merge_parent(merge_names->buf + pos);
1069 merge_names->buf[pos + GIT_SHA1_HEXSZ] = saved;
1070 }
1071 if (!commit) {
1072 if (ptr)
1073 *ptr = '\0';
1074 die(_("not something we can merge in %s: %s"),
1075 filename, merge_names->buf + pos);
1076 }
1077 remotes = &commit_list_insert(commit, remotes)->next;
1078 }
1079
1080 if (merge_names == &fetch_head_file)
1081 strbuf_release(&fetch_head_file);
1082 }
1083
1084 static struct commit_list *collect_parents(struct commit *head_commit,
1085 int *head_subsumed,
1086 int argc, const char **argv,
1087 struct strbuf *merge_msg)
1088 {
1089 int i;
1090 struct commit_list *remoteheads = NULL;
1091 struct commit_list **remotes = &remoteheads;
1092 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1093
1094 if (merge_msg && (!have_message || shortlog_len))
1095 autogen = &merge_names;
1096
1097 if (head_commit)
1098 remotes = &commit_list_insert(head_commit, remotes)->next;
1099
1100 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1101 handle_fetch_head(remotes, autogen);
1102 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1103 } else {
1104 for (i = 0; i < argc; i++) {
1105 struct commit *commit = get_merge_parent(argv[i]);
1106 if (!commit)
1107 help_unknown_ref(argv[i], "merge",
1108 _("not something we can merge"));
1109 remotes = &commit_list_insert(commit, remotes)->next;
1110 }
1111 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1112 if (autogen) {
1113 struct commit_list *p;
1114 for (p = remoteheads; p; p = p->next)
1115 merge_name(merge_remote_util(p->item)->name, autogen);
1116 }
1117 }
1118
1119 if (autogen) {
1120 prepare_merge_message(autogen, merge_msg);
1121 strbuf_release(autogen);
1122 }
1123
1124 return remoteheads;
1125 }
1126
1127 static int merging_a_throwaway_tag(struct commit *commit)
1128 {
1129 char *tag_ref;
1130 struct object_id oid;
1131 int is_throwaway_tag = 0;
1132
1133 /* Are we merging a tag? */
1134 if (!merge_remote_util(commit) ||
1135 !merge_remote_util(commit)->obj ||
1136 merge_remote_util(commit)->obj->type != OBJ_TAG)
1137 return is_throwaway_tag;
1138
1139 /*
1140 * Now we know we are merging a tag object. Are we downstream
1141 * and following the tags from upstream? If so, we must have
1142 * the tag object pointed at by "refs/tags/$T" where $T is the
1143 * tagname recorded in the tag object. We want to allow such
1144 * a "just to catch up" merge to fast-forward.
1145 *
1146 * Otherwise, we are playing an integrator's role, making a
1147 * merge with a throw-away tag from a contributor with
1148 * something like "git pull $contributor $signed_tag".
1149 * We want to forbid such a merge from fast-forwarding
1150 * by default; otherwise we would not keep the signature
1151 * anywhere.
1152 */
1153 tag_ref = xstrfmt("refs/tags/%s",
1154 ((struct tag *)merge_remote_util(commit)->obj)->tag);
1155 if (!read_ref(tag_ref, &oid) &&
1156 !oidcmp(&oid, &merge_remote_util(commit)->obj->oid))
1157 is_throwaway_tag = 0;
1158 else
1159 is_throwaway_tag = 1;
1160 free(tag_ref);
1161 return is_throwaway_tag;
1162 }
1163
1164 int cmd_merge(int argc, const char **argv, const char *prefix)
1165 {
1166 struct object_id result_tree, stash, head_oid;
1167 struct commit *head_commit;
1168 struct strbuf buf = STRBUF_INIT;
1169 int 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 int orig_argc = argc;
1176
1177 if (argc == 2 && !strcmp(argv[1], "-h"))
1178 usage_with_options(builtin_merge_usage, builtin_merge_options);
1179
1180 /*
1181 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1182 * current branch.
1183 */
1184 branch = branch_to_free = resolve_refdup("HEAD", 0, &head_oid, NULL);
1185 if (branch)
1186 skip_prefix(branch, "refs/heads/", &branch);
1187 if (!branch || is_null_oid(&head_oid))
1188 head_commit = NULL;
1189 else
1190 head_commit = lookup_commit_or_die(&head_oid, "HEAD");
1191
1192 init_diff_ui_defaults();
1193 git_config(git_merge_config, NULL);
1194
1195 if (branch_mergeoptions)
1196 parse_branch_merge_options(branch_mergeoptions);
1197 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1198 builtin_merge_usage, 0);
1199 if (shortlog_len < 0)
1200 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1201
1202 if (verbosity < 0 && show_progress == -1)
1203 show_progress = 0;
1204
1205 if (abort_current_merge) {
1206 int nargc = 2;
1207 const char *nargv[] = {"reset", "--merge", NULL};
1208
1209 if (orig_argc != 2)
1210 usage_msg_opt(_("--abort expects no arguments"),
1211 builtin_merge_usage, builtin_merge_options);
1212
1213 if (!file_exists(git_path_merge_head()))
1214 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1215
1216 /* Invoke 'git reset --merge' */
1217 ret = cmd_reset(nargc, nargv, prefix);
1218 goto done;
1219 }
1220
1221 if (continue_current_merge) {
1222 int nargc = 1;
1223 const char *nargv[] = {"commit", NULL};
1224
1225 if (orig_argc != 2)
1226 usage_msg_opt(_("--continue expects no arguments"),
1227 builtin_merge_usage, builtin_merge_options);
1228
1229 if (!file_exists(git_path_merge_head()))
1230 die(_("There is no merge in progress (MERGE_HEAD missing)."));
1231
1232 /* Invoke 'git commit' */
1233 ret = cmd_commit(nargc, nargv, prefix);
1234 goto done;
1235 }
1236
1237 if (read_cache_unmerged())
1238 die_resolve_conflict("merge");
1239
1240 if (file_exists(git_path_merge_head())) {
1241 /*
1242 * There is no unmerged entry, don't advise 'git
1243 * add/rm <file>', just 'git commit'.
1244 */
1245 if (advice_resolve_conflict)
1246 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1247 "Please, commit your changes before you merge."));
1248 else
1249 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1250 }
1251 if (file_exists(git_path_cherry_pick_head())) {
1252 if (advice_resolve_conflict)
1253 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1254 "Please, commit your changes before you merge."));
1255 else
1256 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1257 }
1258 resolve_undo_clear();
1259
1260 if (verbosity < 0)
1261 show_diffstat = 0;
1262
1263 if (squash) {
1264 if (fast_forward == FF_NO)
1265 die(_("You cannot combine --squash with --no-ff."));
1266 option_commit = 0;
1267 }
1268
1269 if (!argc) {
1270 if (default_to_upstream)
1271 argc = setup_with_upstream(&argv);
1272 else
1273 die(_("No commit specified and merge.defaultToUpstream not set."));
1274 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1275 argv[0] = "@{-1}";
1276 }
1277
1278 if (!argc)
1279 usage_with_options(builtin_merge_usage,
1280 builtin_merge_options);
1281
1282 if (!head_commit) {
1283 /*
1284 * If the merged head is a valid one there is no reason
1285 * to forbid "git merge" into a branch yet to be born.
1286 * We do the same for "git pull".
1287 */
1288 struct object_id *remote_head_oid;
1289 if (squash)
1290 die(_("Squash commit into empty head not supported yet"));
1291 if (fast_forward == FF_NO)
1292 die(_("Non-fast-forward commit does not make sense into "
1293 "an empty head"));
1294 remoteheads = collect_parents(head_commit, &head_subsumed,
1295 argc, argv, NULL);
1296 if (!remoteheads)
1297 die(_("%s - not something we can merge"), argv[0]);
1298 if (remoteheads->next)
1299 die(_("Can merge only exactly one commit into empty head"));
1300 remote_head_oid = &remoteheads->item->object.oid;
1301 read_empty(remote_head_oid, 0);
1302 update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
1303 UPDATE_REFS_DIE_ON_ERR);
1304 goto done;
1305 }
1306
1307 /*
1308 * All the rest are the commits being merged; prepare
1309 * the standard merge summary message to be appended
1310 * to the given message.
1311 */
1312 remoteheads = collect_parents(head_commit, &head_subsumed,
1313 argc, argv, &merge_msg);
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_MAX_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.oid, 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 oid_to_hex(&commit->object.oid));
1359 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1360 strbuf_reset(&buf);
1361 if (fast_forward != FF_ONLY && merging_a_throwaway_tag(commit))
1362 fast_forward = FF_NO;
1363 }
1364
1365 if (option_edit < 0)
1366 option_edit = default_edit_option();
1367
1368 if (!use_strategies) {
1369 if (!remoteheads)
1370 ; /* already up-to-date */
1371 else if (!remoteheads->next)
1372 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1373 else
1374 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1375 }
1376
1377 for (i = 0; i < use_strategies_nr; i++) {
1378 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1379 fast_forward = FF_NO;
1380 if (use_strategies[i]->attr & NO_TRIVIAL)
1381 allow_trivial = 0;
1382 }
1383
1384 if (!remoteheads)
1385 ; /* already up-to-date */
1386 else if (!remoteheads->next)
1387 common = get_merge_bases(head_commit, remoteheads->item);
1388 else {
1389 struct commit_list *list = remoteheads;
1390 commit_list_insert(head_commit, &list);
1391 common = get_octopus_merge_bases(list);
1392 free(list);
1393 }
1394
1395 update_ref("updating ORIG_HEAD", "ORIG_HEAD",
1396 &head_commit->object.oid, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1397
1398 if (remoteheads && !common) {
1399 /* No common ancestors found. */
1400 if (!allow_unrelated_histories)
1401 die(_("refusing to merge unrelated histories"));
1402 /* otherwise, 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 !oidcmp(&common->item->object.oid, &head_commit->object.oid)) {
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 printf(_("Updating %s..%s\n"),
1421 find_unique_abbrev(&head_commit->object.oid,
1422 DEFAULT_ABBREV),
1423 find_unique_abbrev(&remoteheads->item->object.oid,
1424 DEFAULT_ABBREV));
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,
1437 &commit->object.oid,
1438 overwrite_ignore)) {
1439 ret = 1;
1440 goto done;
1441 }
1442
1443 finish(head_commit, remoteheads, &commit->object.oid, 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,
1463 &head_commit->object.oid,
1464 &remoteheads->item->object.oid)) {
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 (oidcmp(&common_one->item->object.oid, &j->item->object.oid)) {
1488 up_to_date = 0;
1489 break;
1490 }
1491 }
1492 if (up_to_date) {
1493 finish_up_to_date(_("Already up to date. Yeeah!"));
1494 goto done;
1495 }
1496 }
1497
1498 if (fast_forward == FF_ONLY)
1499 die(_("Not possible to fast-forward, aborting."));
1500
1501 /* We are going to make a new commit. */
1502 git_committer_info(IDENT_STRICT);
1503
1504 /*
1505 * At this point, we need a real merge. No matter what strategy
1506 * we use, it would operate on the index, possibly affecting the
1507 * working tree, and when resolved cleanly, have the desired
1508 * tree in the index -- this means that the index must be in
1509 * sync with the head commit. The strategies are responsible
1510 * to ensure this.
1511 */
1512 if (use_strategies_nr == 1 ||
1513 /*
1514 * Stash away the local changes so that we can try more than one.
1515 */
1516 save_state(&stash))
1517 oidclr(&stash);
1518
1519 for (i = 0; i < use_strategies_nr; i++) {
1520 int ret;
1521 if (i) {
1522 printf(_("Rewinding the tree to pristine...\n"));
1523 restore_state(&head_commit->object.oid, &stash);
1524 }
1525 if (use_strategies_nr != 1)
1526 printf(_("Trying merge strategy %s...\n"),
1527 use_strategies[i]->name);
1528 /*
1529 * Remember which strategy left the state in the working
1530 * tree.
1531 */
1532 wt_strategy = use_strategies[i]->name;
1533
1534 ret = try_merge_strategy(use_strategies[i]->name,
1535 common, remoteheads,
1536 head_commit);
1537 if (!option_commit && !ret) {
1538 merge_was_ok = 1;
1539 /*
1540 * This is necessary here just to avoid writing
1541 * the tree, but later we will *not* exit with
1542 * status code 1 because merge_was_ok is set.
1543 */
1544 ret = 1;
1545 }
1546
1547 if (ret) {
1548 /*
1549 * The backend exits with 1 when conflicts are
1550 * left to be resolved, with 2 when it does not
1551 * handle the given merge at all.
1552 */
1553 if (ret == 1) {
1554 int cnt = evaluate_result();
1555
1556 if (best_cnt <= 0 || cnt <= best_cnt) {
1557 best_strategy = use_strategies[i]->name;
1558 best_cnt = cnt;
1559 }
1560 }
1561 if (merge_was_ok)
1562 break;
1563 else
1564 continue;
1565 }
1566
1567 /* Automerge succeeded. */
1568 write_tree_trivial(&result_tree);
1569 automerge_was_ok = 1;
1570 break;
1571 }
1572
1573 /*
1574 * If we have a resulting tree, that means the strategy module
1575 * auto resolved the merge cleanly.
1576 */
1577 if (automerge_was_ok) {
1578 ret = finish_automerge(head_commit, head_subsumed,
1579 common, remoteheads,
1580 &result_tree, wt_strategy);
1581 goto done;
1582 }
1583
1584 /*
1585 * Pick the result from the best strategy and have the user fix
1586 * it up.
1587 */
1588 if (!best_strategy) {
1589 restore_state(&head_commit->object.oid, &stash);
1590 if (use_strategies_nr > 1)
1591 fprintf(stderr,
1592 _("No merge strategy handled the merge.\n"));
1593 else
1594 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1595 use_strategies[0]->name);
1596 ret = 2;
1597 goto done;
1598 } else if (best_strategy == wt_strategy)
1599 ; /* We already have its result in the working tree. */
1600 else {
1601 printf(_("Rewinding the tree to pristine...\n"));
1602 restore_state(&head_commit->object.oid, &stash);
1603 printf(_("Using the %s to prepare resolving by hand.\n"),
1604 best_strategy);
1605 try_merge_strategy(best_strategy, common, remoteheads,
1606 head_commit);
1607 }
1608
1609 if (squash)
1610 finish(head_commit, remoteheads, NULL, NULL);
1611 else
1612 write_merge_state(remoteheads);
1613
1614 if (merge_was_ok)
1615 fprintf(stderr, _("Automatic merge went well; "
1616 "stopped before committing as requested\n"));
1617 else
1618 ret = suggest_conflicts();
1619
1620 done:
1621 free(branch_to_free);
1622 return ret;
1623 }