source: git/branches/dmik/builtin/merge.c@ 782

Last change on this file since 782 was 782, checked in by dmik, 11 years ago

git: Merge version 2.0.0 from vendor to dmik branch.
File size: 42.1 KB
Line 
1/*
2 * Builtin "git merge"
3 *
4 * Copyright (c) 2008 Miklos Vajna <vmiklos@frugalware.org>
5 *
6 * Based on git-merge.sh by Junio C Hamano.
7 */
8
9#include "cache.h"
10#include "parse-options.h"
11#include "builtin.h"
12#include "run-command.h"
13#include "diff.h"
14#include "refs.h"
15#include "commit.h"
16#include "diffcore.h"
17#include "revision.h"
18#include "unpack-trees.h"
19#include "cache-tree.h"
20#include "dir.h"
21#include "utf8.h"
22#include "log-tree.h"
23#include "color.h"
24#include "rerere.h"
25#include "help.h"
26#include "merge-recursive.h"
27#include "resolve-undo.h"
28#include "remote.h"
29#include "fmt-merge-msg.h"
30#include "gpg-interface.h"
31
32#define DEFAULT_TWOHEAD (1<<0)
33#define DEFAULT_OCTOPUS (1<<1)
34#define NO_FAST_FORWARD (1<<2)
35#define NO_TRIVIAL (1<<3)
36
37struct strategy {
38 const char *name;
39 unsigned attr;
40};
41
42static const char * const builtin_merge_usage[] = {
43 N_("git merge [options] [<commit>...]"),
44 N_("git merge [options] <msg> HEAD <commit>"),
45 N_("git merge --abort"),
46 NULL
47};
48
49static int show_diffstat = 1, shortlog_len = -1, squash;
50static int option_commit = 1;
51static int option_edit = -1;
52static int allow_trivial = 1, have_message, verify_signatures;
53static int overwrite_ignore = 1;
54static struct strbuf merge_msg = STRBUF_INIT;
55static struct strategy **use_strategies;
56static size_t use_strategies_nr, use_strategies_alloc;
57static const char **xopts;
58static size_t xopts_nr, xopts_alloc;
59static const char *branch;
60static char *branch_mergeoptions;
61static int option_renormalize;
62static int verbosity;
63static int allow_rerere_auto;
64static int abort_current_merge;
65static int show_progress = -1;
66static int default_to_upstream;
67static const char *sign_commit;
68
69static struct strategy all_strategy[] = {
70 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
71 { "octopus", DEFAULT_OCTOPUS },
72 { "resolve", 0 },
73 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
74 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
75};
76
77static const char *pull_twohead, *pull_octopus;
78
79enum ff_type {
80 FF_NO,
81 FF_ALLOW,
82 FF_ONLY
83};
84
85static enum ff_type fast_forward = FF_ALLOW;
86
87static int option_parse_message(const struct option *opt,
88 const char *arg, int unset)
89{
90 struct strbuf *buf = opt->value;
91
92 if (unset)
93 strbuf_setlen(buf, 0);
94 else if (arg) {
95 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
96 have_message = 1;
97 } else
98 return error(_("switch `m' requires a value"));
99 return 0;
100}
101
102static struct strategy *get_strategy(const char *name)
103{
104 int i;
105 struct strategy *ret;
106 static struct cmdnames main_cmds, other_cmds;
107 static int loaded;
108
109 if (!name)
110 return NULL;
111
112 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
113 if (!strcmp(name, all_strategy[i].name))
114 return &all_strategy[i];
115
116 if (!loaded) {
117 struct cmdnames not_strategies;
118 loaded = 1;
119
120 memset(&not_strategies, 0, sizeof(struct cmdnames));
121 load_command_list("git-merge-", &main_cmds, &other_cmds);
122 for (i = 0; i < main_cmds.cnt; i++) {
123 int j, found = 0;
124 struct cmdname *ent = main_cmds.names[i];
125 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
126 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
127 && !all_strategy[j].name[ent->len])
128 found = 1;
129 if (!found)
130 add_cmdname(&not_strategies, ent->name, ent->len);
131 }
132 exclude_cmds(&main_cmds, &not_strategies);
133 }
134 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
135 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
136 fprintf(stderr, _("Available strategies are:"));
137 for (i = 0; i < main_cmds.cnt; i++)
138 fprintf(stderr, " %s", main_cmds.names[i]->name);
139 fprintf(stderr, ".\n");
140 if (other_cmds.cnt) {
141 fprintf(stderr, _("Available custom strategies are:"));
142 for (i = 0; i < other_cmds.cnt; i++)
143 fprintf(stderr, " %s", other_cmds.names[i]->name);
144 fprintf(stderr, ".\n");
145 }
146 exit(1);
147 }
148
149 ret = xcalloc(1, sizeof(struct strategy));
150 ret->name = xstrdup(name);
151 ret->attr = NO_TRIVIAL;
152 return ret;
153}
154
155static void append_strategy(struct strategy *s)
156{
157 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
158 use_strategies[use_strategies_nr++] = s;
159}
160
161static int option_parse_strategy(const struct option *opt,
162 const char *name, int unset)
163{
164 if (unset)
165 return 0;
166
167 append_strategy(get_strategy(name));
168 return 0;
169}
170
171static int option_parse_x(const struct option *opt,
172 const char *arg, int unset)
173{
174 if (unset)
175 return 0;
176
177 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
178 xopts[xopts_nr++] = xstrdup(arg);
179 return 0;
180}
181
182static int option_parse_n(const struct option *opt,
183 const char *arg, int unset)
184{
185 show_diffstat = unset;
186 return 0;
187}
188
189static struct option builtin_merge_options[] = {
190 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
191 N_("do not show a diffstat at the end of the merge"),
192 PARSE_OPT_NOARG, option_parse_n },
193 OPT_BOOL(0, "stat", &show_diffstat,
194 N_("show a diffstat at the end of the merge")),
195 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
196 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
197 N_("add (at most <n>) entries from shortlog to merge commit message"),
198 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
199 OPT_BOOL(0, "squash", &squash,
200 N_("create a single commit instead of doing a merge")),
201 OPT_BOOL(0, "commit", &option_commit,
202 N_("perform a commit if the merge succeeds (default)")),
203 OPT_BOOL('e', "edit", &option_edit,
204 N_("edit message before committing")),
205 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
206 { OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
207 N_("abort if fast-forward is not possible"),
208 PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
209 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
210 OPT_BOOL(0, "verify-signatures", &verify_signatures,
211 N_("Verify that the named commit has a valid GPG signature")),
212 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
213 N_("merge strategy to use"), option_parse_strategy),
214 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
215 N_("option for selected merge strategy"), option_parse_x),
216 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
217 N_("merge commit message (for a non-fast-forward merge)"),
218 option_parse_message),
219 OPT__VERBOSITY(&verbosity),
220 OPT_BOOL(0, "abort", &abort_current_merge,
221 N_("abort the current in-progress merge")),
222 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
223 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
224 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
225 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
226 OPT_END()
227};
228
229/* Cleans up metadata that is uninteresting after a succeeded merge. */
230static void drop_save(void)
231{
232 unlink(git_path("MERGE_HEAD"));
233 unlink(git_path("MERGE_MSG"));
234 unlink(git_path("MERGE_MODE"));
235}
236
237static int save_state(unsigned char *stash)
238{
239 int len;
240 struct child_process cp;
241 struct strbuf buffer = STRBUF_INIT;
242 const char *argv[] = {"stash", "create", NULL};
243
244 memset(&cp, 0, sizeof(cp));
245 cp.argv = argv;
246 cp.out = -1;
247 cp.git_cmd = 1;
248
249 if (start_command(&cp))
250 die(_("could not run stash."));
251 len = strbuf_read(&buffer, cp.out, 1024);
252 close(cp.out);
253
254 if (finish_command(&cp) || len < 0)
255 die(_("stash failed"));
256 else if (!len) /* no changes */
257 return -1;
258 strbuf_setlen(&buffer, buffer.len-1);
259 if (get_sha1(buffer.buf, stash))
260 die(_("not a valid object: %s"), buffer.buf);
261 return 0;
262}
263
264static void read_empty(unsigned const char *sha1, int verbose)
265{
266 int i = 0;
267 const char *args[7];
268
269 args[i++] = "read-tree";
270 if (verbose)
271 args[i++] = "-v";
272 args[i++] = "-m";
273 args[i++] = "-u";
274 args[i++] = EMPTY_TREE_SHA1_HEX;
275 args[i++] = sha1_to_hex(sha1);
276 args[i] = NULL;
277
278 if (run_command_v_opt(args, RUN_GIT_CMD))
279 die(_("read-tree failed"));
280}
281
282static void reset_hard(unsigned const char *sha1, int verbose)
283{
284 int i = 0;
285 const char *args[6];
286
287 args[i++] = "read-tree";
288 if (verbose)
289 args[i++] = "-v";
290 args[i++] = "--reset";
291 args[i++] = "-u";
292 args[i++] = sha1_to_hex(sha1);
293 args[i] = NULL;
294
295 if (run_command_v_opt(args, RUN_GIT_CMD))
296 die(_("read-tree failed"));
297}
298
299static void restore_state(const unsigned char *head,
300 const unsigned char *stash)
301{
302 struct strbuf sb = STRBUF_INIT;
303 const char *args[] = { "stash", "apply", NULL, NULL };
304
305 if (is_null_sha1(stash))
306 return;
307
308 reset_hard(head, 1);
309
310 args[2] = sha1_to_hex(stash);
311
312 /*
313 * It is OK to ignore error here, for example when there was
314 * nothing to restore.
315 */
316 run_command_v_opt(args, RUN_GIT_CMD);
317
318 strbuf_release(&sb);
319 refresh_cache(REFRESH_QUIET);
320}
321
322/* This is called when no merge was necessary. */
323static void finish_up_to_date(const char *msg)
324{
325 if (verbosity >= 0)
326 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
327 drop_save();
328}
329
330static void squash_message(struct commit *commit, struct commit_list *remoteheads)
331{
332 struct rev_info rev;
333 struct strbuf out = STRBUF_INIT;
334 struct commit_list *j;
335 const char *filename;
336 int fd;
337 struct pretty_print_context ctx = {0};
338
339 printf(_("Squash commit -- not updating HEAD\n"));
340 filename = git_path("SQUASH_MSG");
341 fd = open(filename, O_WRONLY | O_CREAT, 0666);
342 if (fd < 0)
343 die_errno(_("Could not write to '%s'"), filename);
344
345 init_revisions(&rev, NULL);
346 rev.ignore_merges = 1;
347 rev.commit_format = CMIT_FMT_MEDIUM;
348
349 commit->object.flags |= UNINTERESTING;
350 add_pending_object(&rev, &commit->object, NULL);
351
352 for (j = remoteheads; j; j = j->next)
353 add_pending_object(&rev, &j->item->object, NULL);
354
355 setup_revisions(0, NULL, &rev, NULL);
356 if (prepare_revision_walk(&rev))
357 die(_("revision walk setup failed"));
358
359 ctx.abbrev = rev.abbrev;
360 ctx.date_mode = rev.date_mode;
361 ctx.fmt = rev.commit_format;
362
363 strbuf_addstr(&out, "Squashed commit of the following:\n");
364 while ((commit = get_revision(&rev)) != NULL) {
365 strbuf_addch(&out, '\n');
366 strbuf_addf(&out, "commit %s\n",
367 sha1_to_hex(commit->object.sha1));
368 pretty_print_commit(&ctx, commit, &out);
369 }
370 if (write_in_full(fd, out.buf, out.len) != out.len)
371 die_errno(_("Writing SQUASH_MSG"));
372 if (close(fd))
373 die_errno(_("Finishing SQUASH_MSG"));
374 strbuf_release(&out);
375}
376
377static void finish(struct commit *head_commit,
378 struct commit_list *remoteheads,
379 const unsigned char *new_head, const char *msg)
380{
381 struct strbuf reflog_message = STRBUF_INIT;
382 const unsigned char *head = head_commit->object.sha1;
383
384 if (!msg)
385 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
386 else {
387 if (verbosity >= 0)
388 printf("%s\n", msg);
389 strbuf_addf(&reflog_message, "%s: %s",
390 getenv("GIT_REFLOG_ACTION"), msg);
391 }
392 if (squash) {
393 squash_message(head_commit, remoteheads);
394 } else {
395 if (verbosity >= 0 && !merge_msg.len)
396 printf(_("No merge message -- not updating HEAD\n"));
397 else {
398 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
399 update_ref(reflog_message.buf, "HEAD",
400 new_head, head, 0,
401 DIE_ON_ERR);
402 /*
403 * We ignore errors in 'gc --auto', since the
404 * user should see them.
405 */
406 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
407 }
408 }
409 if (new_head && show_diffstat) {
410 struct diff_options opts;
411 diff_setup(&opts);
412 opts.stat_width = -1; /* use full terminal width */
413 opts.stat_graph_width = -1; /* respect statGraphWidth config */
414 opts.output_format |=
415 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
416 opts.detect_rename = DIFF_DETECT_RENAME;
417 diff_setup_done(&opts);
418 diff_tree_sha1(head, new_head, "", &opts);
419 diffcore_std(&opts);
420 diff_flush(&opts);
421 }
422
423 /* Run a post-merge hook */
424 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
425
426 strbuf_release(&reflog_message);
427}
428
429/* Get the name for the merge commit's message. */
430static void merge_name(const char *remote, struct strbuf *msg)
431{
432 struct commit *remote_head;
433 unsigned char branch_head[20];
434 struct strbuf buf = STRBUF_INIT;
435 struct strbuf bname = STRBUF_INIT;
436 const char *ptr;
437 char *found_ref;
438 int len, early;
439
440 strbuf_branchname(&bname, remote);
441 remote = bname.buf;
442
443 memset(branch_head, 0, sizeof(branch_head));
444 remote_head = get_merge_parent(remote);
445 if (!remote_head)
446 die(_("'%s' does not point to a commit"), remote);
447
448 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
449 if (starts_with(found_ref, "refs/heads/")) {
450 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
451 sha1_to_hex(branch_head), remote);
452 goto cleanup;
453 }
454 if (starts_with(found_ref, "refs/tags/")) {
455 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
456 sha1_to_hex(branch_head), remote);
457 goto cleanup;
458 }
459 if (starts_with(found_ref, "refs/remotes/")) {
460 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
461 sha1_to_hex(branch_head), remote);
462 goto cleanup;
463 }
464 }
465
466 /* See if remote matches <name>^^^.. or <name>~<number> */
467 for (len = 0, ptr = remote + strlen(remote);
468 remote < ptr && ptr[-1] == '^';
469 ptr--)
470 len++;
471 if (len)
472 early = 1;
473 else {
474 early = 0;
475 ptr = strrchr(remote, '~');
476 if (ptr) {
477 int seen_nonzero = 0;
478
479 len++; /* count ~ */
480 while (*++ptr && isdigit(*ptr)) {
481 seen_nonzero |= (*ptr != '0');
482 len++;
483 }
484 if (*ptr)
485 len = 0; /* not ...~<number> */
486 else if (seen_nonzero)
487 early = 1;
488 else if (len == 1)
489 early = 1; /* "name~" is "name~1"! */
490 }
491 }
492 if (len) {
493 struct strbuf truname = STRBUF_INIT;
494 strbuf_addstr(&truname, "refs/heads/");
495 strbuf_addstr(&truname, remote);
496 strbuf_setlen(&truname, truname.len - len);
497 if (ref_exists(truname.buf)) {
498 strbuf_addf(msg,
499 "%s\t\tbranch '%s'%s of .\n",
500 sha1_to_hex(remote_head->object.sha1),
501 truname.buf + 11,
502 (early ? " (early part)" : ""));
503 strbuf_release(&truname);
504 goto cleanup;
505 }
506 }
507
508 if (!strcmp(remote, "FETCH_HEAD") &&
509 !access(git_path("FETCH_HEAD"), R_OK)) {
510 const char *filename;
511 FILE *fp;
512 struct strbuf line = STRBUF_INIT;
513 char *ptr;
514
515 filename = git_path("FETCH_HEAD");
516 fp = fopen(filename, "r");
517 if (!fp)
518 die_errno(_("could not open '%s' for reading"),
519 filename);
520 strbuf_getline(&line, fp, '\n');
521 fclose(fp);
522 ptr = strstr(line.buf, "\tnot-for-merge\t");
523 if (ptr)
524 strbuf_remove(&line, ptr-line.buf+1, 13);
525 strbuf_addbuf(msg, &line);
526 strbuf_release(&line);
527 goto cleanup;
528 }
529
530 if (remote_head->util) {
531 struct merge_remote_desc *desc;
532 desc = merge_remote_util(remote_head);
533 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
534 strbuf_addf(msg, "%s\t\t%s '%s'\n",
535 sha1_to_hex(desc->obj->sha1),
536 typename(desc->obj->type),
537 remote);
538 goto cleanup;
539 }
540 }
541
542 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
543 sha1_to_hex(remote_head->object.sha1), remote);
544cleanup:
545 strbuf_release(&buf);
546 strbuf_release(&bname);
547}
548
549static void parse_branch_merge_options(char *bmo)
550{
551 const char **argv;
552 int argc;
553
554 if (!bmo)
555 return;
556 argc = split_cmdline(bmo, &argv);
557 if (argc < 0)
558 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
559 split_cmdline_strerror(argc));
560 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
561 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
562 argc++;
563 argv[0] = "branch.*.mergeoptions";
564 parse_options(argc, argv, NULL, builtin_merge_options,
565 builtin_merge_usage, 0);
566 free(argv);
567}
568
569static int git_merge_config(const char *k, const char *v, void *cb)
570{
571 int status;
572
573 if (branch && starts_with(k, "branch.") &&
574 starts_with(k + 7, branch) &&
575 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
576 free(branch_mergeoptions);
577 branch_mergeoptions = xstrdup(v);
578 return 0;
579 }
580
581 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
582 show_diffstat = git_config_bool(k, v);
583 else if (!strcmp(k, "pull.twohead"))
584 return git_config_string(&pull_twohead, k, v);
585 else if (!strcmp(k, "pull.octopus"))
586 return git_config_string(&pull_octopus, k, v);
587 else if (!strcmp(k, "merge.renormalize"))
588 option_renormalize = git_config_bool(k, v);
589 else if (!strcmp(k, "merge.ff")) {
590 int boolval = git_config_maybe_bool(k, v);
591 if (0 <= boolval) {
592 fast_forward = boolval ? FF_ALLOW : FF_NO;
593 } else if (v && !strcmp(v, "only")) {
594 fast_forward = FF_ONLY;
595 } /* do not barf on values from future versions of git */
596 return 0;
597 } else if (!strcmp(k, "merge.defaulttoupstream")) {
598 default_to_upstream = git_config_bool(k, v);
599 return 0;
600 } else if (!strcmp(k, "commit.gpgsign")) {
601 sign_commit = git_config_bool(k, v) ? "" : NULL;
602 return 0;
603 }
604
605 status = fmt_merge_msg_config(k, v, cb);
606 if (status)
607 return status;
608 status = git_gpg_config(k, v, NULL);
609 if (status)
610 return status;
611 return git_diff_ui_config(k, v, cb);
612}
613
614static int read_tree_trivial(unsigned char *common, unsigned char *head,
615 unsigned char *one)
616{
617 int i, nr_trees = 0;
618 struct tree *trees[MAX_UNPACK_TREES];
619 struct tree_desc t[MAX_UNPACK_TREES];
620 struct unpack_trees_options opts;
621
622 memset(&opts, 0, sizeof(opts));
623 opts.head_idx = 2;
624 opts.src_index = &the_index;
625 opts.dst_index = &the_index;
626 opts.update = 1;
627 opts.verbose_update = 1;
628 opts.trivial_merges_only = 1;
629 opts.merge = 1;
630 trees[nr_trees] = parse_tree_indirect(common);
631 if (!trees[nr_trees++])
632 return -1;
633 trees[nr_trees] = parse_tree_indirect(head);
634 if (!trees[nr_trees++])
635 return -1;
636 trees[nr_trees] = parse_tree_indirect(one);
637 if (!trees[nr_trees++])
638 return -1;
639 opts.fn = threeway_merge;
640 cache_tree_free(&active_cache_tree);
641 for (i = 0; i < nr_trees; i++) {
642 parse_tree(trees[i]);
643 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
644 }
645 if (unpack_trees(nr_trees, t, &opts))
646 return -1;
647 return 0;
648}
649
650static void write_tree_trivial(unsigned char *sha1)
651{
652 if (write_cache_as_tree(sha1, 0, NULL))
653 die(_("git write-tree failed to write a tree"));
654}
655
656static int try_merge_strategy(const char *strategy, struct commit_list *common,
657 struct commit_list *remoteheads,
658 struct commit *head, const char *head_arg)
659{
660 int index_fd;
661 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
662
663 index_fd = hold_locked_index(lock, 1);
664 refresh_cache(REFRESH_QUIET);
665 if (active_cache_changed &&
666 (write_cache(index_fd, active_cache, active_nr) ||
667 commit_locked_index(lock)))
668 return error(_("Unable to write index."));
669 rollback_lock_file(lock);
670
671 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
672 int clean, x;
673 struct commit *result;
674 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
675 int index_fd;
676 struct commit_list *reversed = NULL;
677 struct merge_options o;
678 struct commit_list *j;
679
680 if (remoteheads->next) {
681 error(_("Not handling anything other than two heads merge."));
682 return 2;
683 }
684
685 init_merge_options(&o);
686 if (!strcmp(strategy, "subtree"))
687 o.subtree_shift = "";
688
689 o.renormalize = option_renormalize;
690 o.show_rename_progress =
691 show_progress == -1 ? isatty(2) : show_progress;
692
693 for (x = 0; x < xopts_nr; x++)
694 if (parse_merge_opt(&o, xopts[x]))
695 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
696
697 o.branch1 = head_arg;
698 o.branch2 = merge_remote_util(remoteheads->item)->name;
699
700 for (j = common; j; j = j->next)
701 commit_list_insert(j->item, &reversed);
702
703 index_fd = hold_locked_index(lock, 1);
704 clean = merge_recursive(&o, head,
705 remoteheads->item, reversed, &result);
706 if (active_cache_changed &&
707 (write_cache(index_fd, active_cache, active_nr) ||
708 commit_locked_index(lock)))
709 die (_("unable to write %s"), get_index_file());
710 rollback_lock_file(lock);
711 return clean ? 0 : 1;
712 } else {
713 return try_merge_command(strategy, xopts_nr, xopts,
714 common, head_arg, remoteheads);
715 }
716}
717
718static void count_diff_files(struct diff_queue_struct *q,
719 struct diff_options *opt, void *data)
720{
721 int *count = data;
722
723 (*count) += q->nr;
724}
725
726static int count_unmerged_entries(void)
727{
728 int i, ret = 0;
729
730 for (i = 0; i < active_nr; i++)
731 if (ce_stage(active_cache[i]))
732 ret++;
733
734 return ret;
735}
736
737static void split_merge_strategies(const char *string, struct strategy **list,
738 int *nr, int *alloc)
739{
740 char *p, *q, *buf;
741
742 if (!string)
743 return;
744
745 buf = xstrdup(string);
746 q = buf;
747 for (;;) {
748 p = strchr(q, ' ');
749 if (!p) {
750 ALLOC_GROW(*list, *nr + 1, *alloc);
751 (*list)[(*nr)++].name = xstrdup(q);
752 free(buf);
753 return;
754 } else {
755 *p = '\0';
756 ALLOC_GROW(*list, *nr + 1, *alloc);
757 (*list)[(*nr)++].name = xstrdup(q);
758 q = ++p;
759 }
760 }
761}
762
763static void add_strategies(const char *string, unsigned attr)
764{
765 struct strategy *list = NULL;
766 int list_alloc = 0, list_nr = 0, i;
767
768 memset(&list, 0, sizeof(list));
769 split_merge_strategies(string, &list, &list_nr, &list_alloc);
770 if (list) {
771 for (i = 0; i < list_nr; i++)
772 append_strategy(get_strategy(list[i].name));
773 return;
774 }
775 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
776 if (all_strategy[i].attr & attr)
777 append_strategy(&all_strategy[i]);
778
779}
780
781static void write_merge_msg(struct strbuf *msg)
782{
783 const char *filename = git_path("MERGE_MSG");
784 int fd = open(filename, O_WRONLY | O_CREAT, 0666);
785 if (fd < 0)
786 die_errno(_("Could not open '%s' for writing"),
787 filename);
788 if (write_in_full(fd, msg->buf, msg->len) != msg->len)
789 die_errno(_("Could not write to '%s'"), filename);
790 close(fd);
791}
792
793static void read_merge_msg(struct strbuf *msg)
794{
795 const char *filename = git_path("MERGE_MSG");
796 strbuf_reset(msg);
797 if (strbuf_read_file(msg, filename, 0) < 0)
798 die_errno(_("Could not read from '%s'"), filename);
799}
800
801static void write_merge_state(struct commit_list *);
802static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
803{
804 if (err_msg)
805 error("%s", err_msg);
806 fprintf(stderr,
807 _("Not committing merge; use 'git commit' to complete the merge.\n"));
808 write_merge_state(remoteheads);
809 exit(1);
810}
811
812static const char merge_editor_comment[] =
813N_("Please enter a commit message to explain why this merge is necessary,\n"
814 "especially if it merges an updated upstream into a topic branch.\n"
815 "\n"
816 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
817 "the commit.\n");
818
819static void prepare_to_commit(struct commit_list *remoteheads)
820{
821 struct strbuf msg = STRBUF_INIT;
822 strbuf_addbuf(&msg, &merge_msg);
823 strbuf_addch(&msg, '\n');
824 if (0 < option_edit)
825 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
826 write_merge_msg(&msg);
827 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
828 git_path("MERGE_MSG"), "merge", NULL))
829 abort_commit(remoteheads, NULL);
830 if (0 < option_edit) {
831 if (launch_editor(git_path("MERGE_MSG"), NULL, NULL))
832 abort_commit(remoteheads, NULL);
833 }
834 read_merge_msg(&msg);
835 stripspace(&msg, 0 < option_edit);
836 if (!msg.len)
837 abort_commit(remoteheads, _("Empty commit message."));
838 strbuf_release(&merge_msg);
839 strbuf_addbuf(&merge_msg, &msg);
840 strbuf_release(&msg);
841}
842
843static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
844{
845 unsigned char result_tree[20], result_commit[20];
846 struct commit_list *parent = xmalloc(sizeof(*parent));
847
848 write_tree_trivial(result_tree);
849 printf(_("Wonderful.\n"));
850 parent->item = head;
851 parent->next = xmalloc(sizeof(*parent->next));
852 parent->next->item = remoteheads->item;
853 parent->next->next = NULL;
854 prepare_to_commit(remoteheads);
855 if (commit_tree(&merge_msg, result_tree, parent, result_commit, NULL,
856 sign_commit))
857 die(_("failed to write commit object"));
858 finish(head, remoteheads, result_commit, "In-index merge");
859 drop_save();
860 return 0;
861}
862
863static int finish_automerge(struct commit *head,
864 int head_subsumed,
865 struct commit_list *common,
866 struct commit_list *remoteheads,
867 unsigned char *result_tree,
868 const char *wt_strategy)
869{
870 struct commit_list *parents = NULL;
871 struct strbuf buf = STRBUF_INIT;
872 unsigned char result_commit[20];
873
874 free_commit_list(common);
875 parents = remoteheads;
876 if (!head_subsumed || fast_forward == FF_NO)
877 commit_list_insert(head, &parents);
878 strbuf_addch(&merge_msg, '\n');
879 prepare_to_commit(remoteheads);
880 if (commit_tree(&merge_msg, result_tree, parents, result_commit,
881 NULL, sign_commit))
882 die(_("failed to write commit object"));
883 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
884 finish(head, remoteheads, result_commit, buf.buf);
885 strbuf_release(&buf);
886 drop_save();
887 return 0;
888}
889
890static int suggest_conflicts(int renormalizing)
891{
892 const char *filename;
893 FILE *fp;
894 int pos;
895
896 filename = git_path("MERGE_MSG");
897 fp = fopen(filename, "a");
898 if (!fp)
899 die_errno(_("Could not open '%s' for writing"), filename);
900 fprintf(fp, "\nConflicts:\n");
901 for (pos = 0; pos < active_nr; pos++) {
902 const struct cache_entry *ce = active_cache[pos];
903
904 if (ce_stage(ce)) {
905 fprintf(fp, "\t%s\n", ce->name);
906 while (pos + 1 < active_nr &&
907 !strcmp(ce->name,
908 active_cache[pos + 1]->name))
909 pos++;
910 }
911 }
912 fclose(fp);
913 rerere(allow_rerere_auto);
914 printf(_("Automatic merge failed; "
915 "fix conflicts and then commit the result.\n"));
916 return 1;
917}
918
919static struct commit *is_old_style_invocation(int argc, const char **argv,
920 const unsigned char *head)
921{
922 struct commit *second_token = NULL;
923 if (argc > 2) {
924 unsigned char second_sha1[20];
925
926 if (get_sha1(argv[1], second_sha1))
927 return NULL;
928 second_token = lookup_commit_reference_gently(second_sha1, 0);
929 if (!second_token)
930 die(_("'%s' is not a commit"), argv[1]);
931 if (hashcmp(second_token->object.sha1, head))
932 return NULL;
933 }
934 return second_token;
935}
936
937static int evaluate_result(void)
938{
939 int cnt = 0;
940 struct rev_info rev;
941
942 /* Check how many files differ. */
943 init_revisions(&rev, "");
944 setup_revisions(0, NULL, &rev, NULL);
945 rev.diffopt.output_format |=
946 DIFF_FORMAT_CALLBACK;
947 rev.diffopt.format_callback = count_diff_files;
948 rev.diffopt.format_callback_data = &cnt;
949 run_diff_files(&rev, 0);
950
951 /*
952 * Check how many unmerged entries are
953 * there.
954 */
955 cnt += count_unmerged_entries();
956
957 return cnt;
958}
959
960/*
961 * Pretend as if the user told us to merge with the remote-tracking
962 * branch we have for the upstream of the current branch
963 */
964static int setup_with_upstream(const char ***argv)
965{
966 struct branch *branch = branch_get(NULL);
967 int i;
968 const char **args;
969
970 if (!branch)
971 die(_("No current branch."));
972 if (!branch->remote)
973 die(_("No remote for the current branch."));
974 if (!branch->merge_nr)
975 die(_("No default upstream defined for the current branch."));
976
977 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
978 for (i = 0; i < branch->merge_nr; i++) {
979 if (!branch->merge[i]->dst)
980 die(_("No remote-tracking branch for %s from %s"),
981 branch->merge[i]->src, branch->remote_name);
982 args[i] = branch->merge[i]->dst;
983 }
984 args[i] = NULL;
985 *argv = args;
986 return i;
987}
988
989static void write_merge_state(struct commit_list *remoteheads)
990{
991 const char *filename;
992 int fd;
993 struct commit_list *j;
994 struct strbuf buf = STRBUF_INIT;
995
996 for (j = remoteheads; j; j = j->next) {
997 unsigned const char *sha1;
998 struct commit *c = j->item;
999 if (c->util && merge_remote_util(c)->obj) {
1000 sha1 = merge_remote_util(c)->obj->sha1;
1001 } else {
1002 sha1 = c->object.sha1;
1003 }
1004 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
1005 }
1006 filename = git_path("MERGE_HEAD");
1007 fd = open(filename, O_WRONLY | O_CREAT, 0666);
1008 if (fd < 0)
1009 die_errno(_("Could not open '%s' for writing"), filename);
1010 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1011 die_errno(_("Could not write to '%s'"), filename);
1012 close(fd);
1013 strbuf_addch(&merge_msg, '\n');
1014 write_merge_msg(&merge_msg);
1015
1016 filename = git_path("MERGE_MODE");
1017 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
1018 if (fd < 0)
1019 die_errno(_("Could not open '%s' for writing"), filename);
1020 strbuf_reset(&buf);
1021 if (fast_forward == FF_NO)
1022 strbuf_addf(&buf, "no-ff");
1023 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1024 die_errno(_("Could not write to '%s'"), filename);
1025 close(fd);
1026}
1027
1028static int default_edit_option(void)
1029{
1030 static const char name[] = "GIT_MERGE_AUTOEDIT";
1031 const char *e = getenv(name);
1032 struct stat st_stdin, st_stdout;
1033
1034 if (have_message)
1035 /* an explicit -m msg without --[no-]edit */
1036 return 0;
1037
1038 if (e) {
1039 int v = git_config_maybe_bool(name, e);
1040 if (v < 0)
1041 die("Bad value '%s' in environment '%s'", e, name);
1042 return v;
1043 }
1044
1045 /* Use editor if stdin and stdout are the same and is a tty */
1046 return (!fstat(0, &st_stdin) &&
1047 !fstat(1, &st_stdout) &&
1048 isatty(0) && isatty(1) &&
1049 st_stdin.st_dev == st_stdout.st_dev &&
1050 st_stdin.st_ino == st_stdout.st_ino &&
1051 st_stdin.st_mode == st_stdout.st_mode);
1052}
1053
1054static struct commit_list *collect_parents(struct commit *head_commit,
1055 int *head_subsumed,
1056 int argc, const char **argv)
1057{
1058 int i;
1059 struct commit_list *remoteheads = NULL, *parents, *next;
1060 struct commit_list **remotes = &remoteheads;
1061
1062 if (head_commit)
1063 remotes = &commit_list_insert(head_commit, remotes)->next;
1064 for (i = 0; i < argc; i++) {
1065 struct commit *commit = get_merge_parent(argv[i]);
1066 if (!commit)
1067 help_unknown_ref(argv[i], "merge",
1068 "not something we can merge");
1069 remotes = &commit_list_insert(commit, remotes)->next;
1070 }
1071 *remotes = NULL;
1072
1073 parents = reduce_heads(remoteheads);
1074
1075 *head_subsumed = 1; /* we will flip this to 0 when we find it */
1076 for (remoteheads = NULL, remotes = &remoteheads;
1077 parents;
1078 parents = next) {
1079 struct commit *commit = parents->item;
1080 next = parents->next;
1081 if (commit == head_commit)
1082 *head_subsumed = 0;
1083 else
1084 remotes = &commit_list_insert(commit, remotes)->next;
1085 }
1086 return remoteheads;
1087}
1088
1089int cmd_merge(int argc, const char **argv, const char *prefix)
1090{
1091 unsigned char result_tree[20];
1092 unsigned char stash[20];
1093 unsigned char head_sha1[20];
1094 struct commit *head_commit;
1095 struct strbuf buf = STRBUF_INIT;
1096 const char *head_arg;
1097 int flag, i, ret = 0, head_subsumed;
1098 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1099 struct commit_list *common = NULL;
1100 const char *best_strategy = NULL, *wt_strategy = NULL;
1101 struct commit_list *remoteheads, *p;
1102 void *branch_to_free;
1103
1104 if (argc == 2 && !strcmp(argv[1], "-h"))
1105 usage_with_options(builtin_merge_usage, builtin_merge_options);
1106
1107 /*
1108 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1109 * current branch.
1110 */
1111 branch = branch_to_free = resolve_refdup("HEAD", head_sha1, 0, &flag);
1112 if (branch && starts_with(branch, "refs/heads/"))
1113 branch += 11;
1114 if (!branch || is_null_sha1(head_sha1))
1115 head_commit = NULL;
1116 else
1117 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1118
1119 git_config(git_merge_config, NULL);
1120
1121 if (branch_mergeoptions)
1122 parse_branch_merge_options(branch_mergeoptions);
1123 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1124 builtin_merge_usage, 0);
1125 if (shortlog_len < 0)
1126 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
1127
1128 if (verbosity < 0 && show_progress == -1)
1129 show_progress = 0;
1130
1131 if (abort_current_merge) {
1132 int nargc = 2;
1133 const char *nargv[] = {"reset", "--merge", NULL};
1134
1135 if (!file_exists(git_path("MERGE_HEAD")))
1136 die(_("There is no merge to abort (MERGE_HEAD missing)."));
1137
1138 /* Invoke 'git reset --merge' */
1139 ret = cmd_reset(nargc, nargv, prefix);
1140 goto done;
1141 }
1142
1143 if (read_cache_unmerged())
1144 die_resolve_conflict("merge");
1145
1146 if (file_exists(git_path("MERGE_HEAD"))) {
1147 /*
1148 * There is no unmerged entry, don't advise 'git
1149 * add/rm <file>', just 'git commit'.
1150 */
1151 if (advice_resolve_conflict)
1152 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1153 "Please, commit your changes before you can merge."));
1154 else
1155 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
1156 }
1157 if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
1158 if (advice_resolve_conflict)
1159 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1160 "Please, commit your changes before you can merge."));
1161 else
1162 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
1163 }
1164 resolve_undo_clear();
1165
1166 if (verbosity < 0)
1167 show_diffstat = 0;
1168
1169 if (squash) {
1170 if (fast_forward == FF_NO)
1171 die(_("You cannot combine --squash with --no-ff."));
1172 option_commit = 0;
1173 }
1174
1175 if (!abort_current_merge) {
1176 if (!argc) {
1177 if (default_to_upstream)
1178 argc = setup_with_upstream(&argv);
1179 else
1180 die(_("No commit specified and merge.defaultToUpstream not set."));
1181 } else if (argc == 1 && !strcmp(argv[0], "-"))
1182 argv[0] = "@{-1}";
1183 }
1184 if (!argc)
1185 usage_with_options(builtin_merge_usage,
1186 builtin_merge_options);
1187
1188 /*
1189 * This could be traditional "merge <msg> HEAD <commit>..." and
1190 * the way we can tell it is to see if the second token is HEAD,
1191 * but some people might have misused the interface and used a
1192 * commit-ish that is the same as HEAD there instead.
1193 * Traditional format never would have "-m" so it is an
1194 * additional safety measure to check for it.
1195 */
1196
1197 if (!have_message && head_commit &&
1198 is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
1199 strbuf_addstr(&merge_msg, argv[0]);
1200 head_arg = argv[1];
1201 argv += 2;
1202 argc -= 2;
1203 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1204 } else if (!head_commit) {
1205 struct commit *remote_head;
1206 /*
1207 * If the merged head is a valid one there is no reason
1208 * to forbid "git merge" into a branch yet to be born.
1209 * We do the same for "git pull".
1210 */
1211 if (argc != 1)
1212 die(_("Can merge only exactly one commit into "
1213 "empty head"));
1214 if (squash)
1215 die(_("Squash commit into empty head not supported yet"));
1216 if (fast_forward == FF_NO)
1217 die(_("Non-fast-forward commit does not make sense into "
1218 "an empty head"));
1219 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1220 remote_head = remoteheads->item;
1221 if (!remote_head)
1222 die(_("%s - not something we can merge"), argv[0]);
1223 read_empty(remote_head->object.sha1, 0);
1224 update_ref("initial pull", "HEAD", remote_head->object.sha1,
1225 NULL, 0, DIE_ON_ERR);
1226 goto done;
1227 } else {
1228 struct strbuf merge_names = STRBUF_INIT;
1229
1230 /* We are invoked directly as the first-class UI. */
1231 head_arg = "HEAD";
1232
1233 /*
1234 * All the rest are the commits being merged; prepare
1235 * the standard merge summary message to be appended
1236 * to the given message.
1237 */
1238 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
1239 for (p = remoteheads; p; p = p->next)
1240 merge_name(merge_remote_util(p->item)->name, &merge_names);
1241
1242 if (!have_message || shortlog_len) {
1243 struct fmt_merge_msg_opts opts;
1244 memset(&opts, 0, sizeof(opts));
1245 opts.add_title = !have_message;
1246 opts.shortlog_len = shortlog_len;
1247 opts.credit_people = (0 < option_edit);
1248
1249 fmt_merge_msg(&merge_names, &merge_msg, &opts);
1250 if (merge_msg.len)
1251 strbuf_setlen(&merge_msg, merge_msg.len - 1);
1252 }
1253 }
1254
1255 if (!head_commit || !argc)
1256 usage_with_options(builtin_merge_usage,
1257 builtin_merge_options);
1258
1259 if (verify_signatures) {
1260 for (p = remoteheads; p; p = p->next) {
1261 struct commit *commit = p->item;
1262 char hex[41];
1263 struct signature_check signature_check;
1264 memset(&signature_check, 0, sizeof(signature_check));
1265
1266 check_commit_signature(commit, &signature_check);
1267
1268 strcpy(hex, find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
1269 switch (signature_check.result) {
1270 case 'G':
1271 break;
1272 case 'U':
1273 die(_("Commit %s has an untrusted GPG signature, "
1274 "allegedly by %s."), hex, signature_check.signer);
1275 case 'B':
1276 die(_("Commit %s has a bad GPG signature "
1277 "allegedly by %s."), hex, signature_check.signer);
1278 default: /* 'N' */
1279 die(_("Commit %s does not have a GPG signature."), hex);
1280 }
1281 if (verbosity >= 0 && signature_check.result == 'G')
1282 printf(_("Commit %s has a good GPG signature by %s\n"),
1283 hex, signature_check.signer);
1284
1285 free(signature_check.gpg_output);
1286 free(signature_check.gpg_status);
1287 free(signature_check.signer);
1288 free(signature_check.key);
1289 }
1290 }
1291
1292 strbuf_addstr(&buf, "merge");
1293 for (p = remoteheads; p; p = p->next)
1294 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1295 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1296 strbuf_reset(&buf);
1297
1298 for (p = remoteheads; p; p = p->next) {
1299 struct commit *commit = p->item;
1300 strbuf_addf(&buf, "GITHEAD_%s",
1301 sha1_to_hex(commit->object.sha1));
1302 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1303 strbuf_reset(&buf);
1304 if (fast_forward != FF_ONLY &&
1305 merge_remote_util(commit) &&
1306 merge_remote_util(commit)->obj &&
1307 merge_remote_util(commit)->obj->type == OBJ_TAG)
1308 fast_forward = FF_NO;
1309 }
1310
1311 if (option_edit < 0)
1312 option_edit = default_edit_option();
1313
1314 if (!use_strategies) {
1315 if (!remoteheads)
1316 ; /* already up-to-date */
1317 else if (!remoteheads->next)
1318 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1319 else
1320 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1321 }
1322
1323 for (i = 0; i < use_strategies_nr; i++) {
1324 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1325 fast_forward = FF_NO;
1326 if (use_strategies[i]->attr & NO_TRIVIAL)
1327 allow_trivial = 0;
1328 }
1329
1330 if (!remoteheads)
1331 ; /* already up-to-date */
1332 else if (!remoteheads->next)
1333 common = get_merge_bases(head_commit, remoteheads->item, 1);
1334 else {
1335 struct commit_list *list = remoteheads;
1336 commit_list_insert(head_commit, &list);
1337 common = get_octopus_merge_bases(list);
1338 free(list);
1339 }
1340
1341 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
1342 NULL, 0, DIE_ON_ERR);
1343
1344 if (remoteheads && !common)
1345 ; /* No common ancestors found. We need a real merge. */
1346 else if (!remoteheads ||
1347 (!remoteheads->next && !common->next &&
1348 common->item == remoteheads->item)) {
1349 /*
1350 * If head can reach all the merge then we are up to date.
1351 * but first the most common case of merging one remote.
1352 */
1353 finish_up_to_date("Already up-to-date.");
1354 goto done;
1355 } else if (fast_forward != FF_NO && !remoteheads->next &&
1356 !common->next &&
1357 !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
1358 /* Again the most common case of merging one remote. */
1359 struct strbuf msg = STRBUF_INIT;
1360 struct commit *commit;
1361 char hex[41];
1362
1363 strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
1364
1365 if (verbosity >= 0)
1366 printf(_("Updating %s..%s\n"),
1367 hex,
1368 find_unique_abbrev(remoteheads->item->object.sha1,
1369 DEFAULT_ABBREV));
1370 strbuf_addstr(&msg, "Fast-forward");
1371 if (have_message)
1372 strbuf_addstr(&msg,
1373 " (no commit created; -m option ignored)");
1374 commit = remoteheads->item;
1375 if (!commit) {
1376 ret = 1;
1377 goto done;
1378 }
1379
1380 if (checkout_fast_forward(head_commit->object.sha1,
1381 commit->object.sha1,
1382 overwrite_ignore)) {
1383 ret = 1;
1384 goto done;
1385 }
1386
1387 finish(head_commit, remoteheads, commit->object.sha1, msg.buf);
1388 drop_save();
1389 goto done;
1390 } else if (!remoteheads->next && common->next)
1391 ;
1392 /*
1393 * We are not doing octopus and not fast-forward. Need
1394 * a real merge.
1395 */
1396 else if (!remoteheads->next && !common->next && option_commit) {
1397 /*
1398 * We are not doing octopus, not fast-forward, and have
1399 * only one common.
1400 */
1401 refresh_cache(REFRESH_QUIET);
1402 if (allow_trivial && fast_forward != FF_ONLY) {
1403 /* See if it is really trivial. */
1404 git_committer_info(IDENT_STRICT);
1405 printf(_("Trying really trivial in-index merge...\n"));
1406 if (!read_tree_trivial(common->item->object.sha1,
1407 head_commit->object.sha1,
1408 remoteheads->item->object.sha1)) {
1409 ret = merge_trivial(head_commit, remoteheads);
1410 goto done;
1411 }
1412 printf(_("Nope.\n"));
1413 }
1414 } else {
1415 /*
1416 * An octopus. If we can reach all the remote we are up
1417 * to date.
1418 */
1419 int up_to_date = 1;
1420 struct commit_list *j;
1421
1422 for (j = remoteheads; j; j = j->next) {
1423 struct commit_list *common_one;
1424
1425 /*
1426 * Here we *have* to calculate the individual
1427 * merge_bases again, otherwise "git merge HEAD^
1428 * HEAD^^" would be missed.
1429 */
1430 common_one = get_merge_bases(head_commit, j->item, 1);
1431 if (hashcmp(common_one->item->object.sha1,
1432 j->item->object.sha1)) {
1433 up_to_date = 0;
1434 break;
1435 }
1436 }
1437 if (up_to_date) {
1438 finish_up_to_date("Already up-to-date. Yeeah!");
1439 goto done;
1440 }
1441 }
1442
1443 if (fast_forward == FF_ONLY)
1444 die(_("Not possible to fast-forward, aborting."));
1445
1446 /* We are going to make a new commit. */
1447 git_committer_info(IDENT_STRICT);
1448
1449 /*
1450 * At this point, we need a real merge. No matter what strategy
1451 * we use, it would operate on the index, possibly affecting the
1452 * working tree, and when resolved cleanly, have the desired
1453 * tree in the index -- this means that the index must be in
1454 * sync with the head commit. The strategies are responsible
1455 * to ensure this.
1456 */
1457 if (use_strategies_nr == 1 ||
1458 /*
1459 * Stash away the local changes so that we can try more than one.
1460 */
1461 save_state(stash))
1462 hashcpy(stash, null_sha1);
1463
1464 for (i = 0; i < use_strategies_nr; i++) {
1465 int ret;
1466 if (i) {
1467 printf(_("Rewinding the tree to pristine...\n"));
1468 restore_state(head_commit->object.sha1, stash);
1469 }
1470 if (use_strategies_nr != 1)
1471 printf(_("Trying merge strategy %s...\n"),
1472 use_strategies[i]->name);
1473 /*
1474 * Remember which strategy left the state in the working
1475 * tree.
1476 */
1477 wt_strategy = use_strategies[i]->name;
1478
1479 ret = try_merge_strategy(use_strategies[i]->name,
1480 common, remoteheads,
1481 head_commit, head_arg);
1482 if (!option_commit && !ret) {
1483 merge_was_ok = 1;
1484 /*
1485 * This is necessary here just to avoid writing
1486 * the tree, but later we will *not* exit with
1487 * status code 1 because merge_was_ok is set.
1488 */
1489 ret = 1;
1490 }
1491
1492 if (ret) {
1493 /*
1494 * The backend exits with 1 when conflicts are
1495 * left to be resolved, with 2 when it does not
1496 * handle the given merge at all.
1497 */
1498 if (ret == 1) {
1499 int cnt = evaluate_result();
1500
1501 if (best_cnt <= 0 || cnt <= best_cnt) {
1502 best_strategy = use_strategies[i]->name;
1503 best_cnt = cnt;
1504 }
1505 }
1506 if (merge_was_ok)
1507 break;
1508 else
1509 continue;
1510 }
1511
1512 /* Automerge succeeded. */
1513 write_tree_trivial(result_tree);
1514 automerge_was_ok = 1;
1515 break;
1516 }
1517
1518 /*
1519 * If we have a resulting tree, that means the strategy module
1520 * auto resolved the merge cleanly.
1521 */
1522 if (automerge_was_ok) {
1523 ret = finish_automerge(head_commit, head_subsumed,
1524 common, remoteheads,
1525 result_tree, wt_strategy);
1526 goto done;
1527 }
1528
1529 /*
1530 * Pick the result from the best strategy and have the user fix
1531 * it up.
1532 */
1533 if (!best_strategy) {
1534 restore_state(head_commit->object.sha1, stash);
1535 if (use_strategies_nr > 1)
1536 fprintf(stderr,
1537 _("No merge strategy handled the merge.\n"));
1538 else
1539 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1540 use_strategies[0]->name);
1541 ret = 2;
1542 goto done;
1543 } else if (best_strategy == wt_strategy)
1544 ; /* We already have its result in the working tree. */
1545 else {
1546 printf(_("Rewinding the tree to pristine...\n"));
1547 restore_state(head_commit->object.sha1, stash);
1548 printf(_("Using the %s to prepare resolving by hand.\n"),
1549 best_strategy);
1550 try_merge_strategy(best_strategy, common, remoteheads,
1551 head_commit, head_arg);
1552 }
1553
1554 if (squash)
1555 finish(head_commit, remoteheads, NULL, NULL);
1556 else
1557 write_merge_state(remoteheads);
1558
1559 if (merge_was_ok)
1560 fprintf(stderr, _("Automatic merge went well; "
1561 "stopped before committing as requested\n"));
1562 else
1563 ret = suggest_conflicts(option_renormalize);
1564
1565done:
1566 free(branch_to_free);
1567 return ret;
1568}
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