Merge branch 'mg/killed-merge'
[git/git.git] / builtin / merge.c
CommitLineData
1c7b76be
MV
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"
b2141fc1 10#include "config.h"
1c7b76be
MV
11#include "parse-options.h"
12#include "builtin.h"
697cc8ef 13#include "lockfile.h"
1c7b76be
MV
14#include "run-command.h"
15#include "diff.h"
16#include "refs.h"
17#include "commit.h"
18#include "diffcore.h"
19#include "revision.h"
20#include "unpack-trees.h"
21#include "cache-tree.h"
22#include "dir.h"
23#include "utf8.h"
24#include "log-tree.h"
25#include "color.h"
fcab40a3 26#include "rerere.h"
87091b49 27#include "help.h"
18668f53 28#include "merge-recursive.h"
cfc5789a 29#include "resolve-undo.h"
93e535a5 30#include "remote.h"
898eacd8 31#include "fmt-merge-msg.h"
ba3c69a9 32#include "gpg-interface.h"
75c961b7 33#include "sequencer.h"
02a8cfa4 34#include "string-list.h"
3836d88a 35#include "packfile.h"
1c7b76be
MV
36
37#define DEFAULT_TWOHEAD (1<<0)
38#define DEFAULT_OCTOPUS (1<<1)
39#define NO_FAST_FORWARD (1<<2)
40#define NO_TRIVIAL (1<<3)
41
42struct strategy {
43 const char *name;
44 unsigned attr;
45};
46
47static const char * const builtin_merge_usage[] = {
9c9b4f2f 48 N_("git merge [<options>] [<commit>...]"),
962e6295 49 N_("git merge --abort"),
367ff694 50 N_("git merge --continue"),
1c7b76be
MV
51 NULL
52};
53
898eacd8 54static int show_diffstat = 1, shortlog_len = -1, squash;
a54841e9
MV
55static int option_commit = 1;
56static int option_edit = -1;
efed0022 57static int allow_trivial = 1, have_message, verify_signatures;
c1d7036b 58static int overwrite_ignore = 1;
2c47789d 59static struct strbuf merge_msg = STRBUF_INIT;
1c7b76be
MV
60static struct strategy **use_strategies;
61static size_t use_strategies_nr, use_strategies_alloc;
8cc5b290
AP
62static const char **xopts;
63static size_t xopts_nr, xopts_alloc;
1c7b76be 64static const char *branch;
0d8fc3ef 65static char *branch_mergeoptions;
7610fa57 66static int option_renormalize;
7f87aff2 67static int verbosity;
cb6020bb 68static int allow_rerere_auto;
35d2fffd 69static int abort_current_merge;
367ff694 70static int continue_current_merge;
e379fdf3 71static int allow_unrelated_histories;
99bfc669 72static int show_progress = -1;
a01f7f2b 73static int default_to_upstream = 1;
14d01b4f 74static int signoff;
ba3c69a9 75static const char *sign_commit;
1c7b76be
MV
76
77static struct strategy all_strategy[] = {
1c7b76be
MV
78 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
79 { "octopus", DEFAULT_OCTOPUS },
80 { "resolve", 0 },
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MV
81 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
82 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
83};
84
85static const char *pull_twohead, *pull_octopus;
86
a54841e9
MV
87enum ff_type {
88 FF_NO,
89 FF_ALLOW,
90 FF_ONLY
91};
92
93static enum ff_type fast_forward = FF_ALLOW;
94
1c7b76be
MV
95static int option_parse_message(const struct option *opt,
96 const char *arg, int unset)
97{
98 struct strbuf *buf = opt->value;
99
100 if (unset)
101 strbuf_setlen(buf, 0);
74f5b7fb 102 else if (arg) {
ce9d823b 103 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
1c7b76be 104 have_message = 1;
74f5b7fb 105 } else
bacec478 106 return error(_("switch `m' requires a value"));
1c7b76be
MV
107 return 0;
108}
109
110static struct strategy *get_strategy(const char *name)
111{
112 int i;
87091b49
MV
113 struct strategy *ret;
114 static struct cmdnames main_cmds, other_cmds;
e321180e 115 static int loaded;
1c7b76be
MV
116
117 if (!name)
118 return NULL;
119
120 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
121 if (!strcmp(name, all_strategy[i].name))
122 return &all_strategy[i];
1719b5e4 123
e321180e 124 if (!loaded) {
87091b49 125 struct cmdnames not_strategies;
e321180e 126 loaded = 1;
87091b49 127
87091b49 128 memset(&not_strategies, 0, sizeof(struct cmdnames));
e321180e 129 load_command_list("git-merge-", &main_cmds, &other_cmds);
87091b49
MV
130 for (i = 0; i < main_cmds.cnt; i++) {
131 int j, found = 0;
132 struct cmdname *ent = main_cmds.names[i];
133 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
134 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
135 && !all_strategy[j].name[ent->len])
136 found = 1;
137 if (!found)
138 add_cmdname(&not_strategies, ent->name, ent->len);
87091b49 139 }
ed874656 140 exclude_cmds(&main_cmds, &not_strategies);
87091b49
MV
141 }
142 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
bacec478
ÆAB
143 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
144 fprintf(stderr, _("Available strategies are:"));
131f9a10
JH
145 for (i = 0; i < main_cmds.cnt; i++)
146 fprintf(stderr, " %s", main_cmds.names[i]->name);
147 fprintf(stderr, ".\n");
148 if (other_cmds.cnt) {
bacec478 149 fprintf(stderr, _("Available custom strategies are:"));
131f9a10
JH
150 for (i = 0; i < other_cmds.cnt; i++)
151 fprintf(stderr, " %s", other_cmds.names[i]->name);
152 fprintf(stderr, ".\n");
153 }
87091b49
MV
154 exit(1);
155 }
156
19d4b416 157 ret = xcalloc(1, sizeof(struct strategy));
87091b49 158 ret->name = xstrdup(name);
52b48ef1 159 ret->attr = NO_TRIVIAL;
87091b49 160 return ret;
1c7b76be
MV
161}
162
163static void append_strategy(struct strategy *s)
164{
165 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
166 use_strategies[use_strategies_nr++] = s;
167}
168
169static int option_parse_strategy(const struct option *opt,
170 const char *name, int unset)
171{
1c7b76be
MV
172 if (unset)
173 return 0;
174
1719b5e4 175 append_strategy(get_strategy(name));
1c7b76be
MV
176 return 0;
177}
178
8cc5b290
AP
179static int option_parse_x(const struct option *opt,
180 const char *arg, int unset)
181{
182 if (unset)
183 return 0;
184
185 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
186 xopts[xopts_nr++] = xstrdup(arg);
187 return 0;
188}
189
1c7b76be
MV
190static int option_parse_n(const struct option *opt,
191 const char *arg, int unset)
192{
193 show_diffstat = unset;
194 return 0;
195}
196
197static struct option builtin_merge_options[] = {
198 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
962e6295 199 N_("do not show a diffstat at the end of the merge"),
1c7b76be 200 PARSE_OPT_NOARG, option_parse_n },
d5d09d47 201 OPT_BOOL(0, "stat", &show_diffstat,
962e6295 202 N_("show a diffstat at the end of the merge")),
d5d09d47 203 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
962e6295
NTND
204 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
205 N_("add (at most <n>) entries from shortlog to merge commit message"),
96e9420c 206 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
d5d09d47 207 OPT_BOOL(0, "squash", &squash,
962e6295 208 N_("create a single commit instead of doing a merge")),
d5d09d47 209 OPT_BOOL(0, "commit", &option_commit,
962e6295 210 N_("perform a commit if the merge succeeds (default)")),
f8246281 211 OPT_BOOL('e', "edit", &option_edit,
962e6295 212 N_("edit message before committing")),
a54841e9 213 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
90f867b9 214 { OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
a54841e9 215 N_("abort if fast-forward is not possible"),
90f867b9 216 PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
cb6020bb 217 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
efed0022 218 OPT_BOOL(0, "verify-signatures", &verify_signatures,
c8bb9d2e 219 N_("verify that the named commit has a valid GPG signature")),
962e6295
NTND
220 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
221 N_("merge strategy to use"), option_parse_strategy),
222 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
223 N_("option for selected merge strategy"), option_parse_x),
224 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
225 N_("merge commit message (for a non-fast-forward merge)"),
1c7b76be 226 option_parse_message),
7f87aff2 227 OPT__VERBOSITY(&verbosity),
d5d09d47 228 OPT_BOOL(0, "abort", &abort_current_merge,
962e6295 229 N_("abort the current in-progress merge")),
367ff694
CP
230 OPT_BOOL(0, "continue", &continue_current_merge,
231 N_("continue the current in-progress merge")),
e379fdf3
JH
232 OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
233 N_("allow merging unrelated histories")),
962e6295 234 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
e703d711 235 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
962e6295 236 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
d5d09d47 237 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
14d01b4f 238 OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
1c7b76be
MV
239 OPT_END()
240};
241
242/* Cleans up metadata that is uninteresting after a succeeded merge. */
243static void drop_save(void)
244{
f932729c
JK
245 unlink(git_path_merge_head());
246 unlink(git_path_merge_msg());
247 unlink(git_path_merge_mode());
1c7b76be
MV
248}
249
52684310 250static int save_state(struct object_id *stash)
1c7b76be
MV
251{
252 int len;
d3180279 253 struct child_process cp = CHILD_PROCESS_INIT;
1c7b76be
MV
254 struct strbuf buffer = STRBUF_INIT;
255 const char *argv[] = {"stash", "create", NULL};
256
1c7b76be
MV
257 cp.argv = argv;
258 cp.out = -1;
259 cp.git_cmd = 1;
260
261 if (start_command(&cp))
bacec478 262 die(_("could not run stash."));
1c7b76be
MV
263 len = strbuf_read(&buffer, cp.out, 1024);
264 close(cp.out);
265
266 if (finish_command(&cp) || len < 0)
bacec478 267 die(_("stash failed"));
b4fd9406
NTND
268 else if (!len) /* no changes */
269 return -1;
1c7b76be 270 strbuf_setlen(&buffer, buffer.len-1);
52684310 271 if (get_oid(buffer.buf, stash))
bacec478 272 die(_("not a valid object: %s"), buffer.buf);
b4fd9406 273 return 0;
1c7b76be
MV
274}
275
172b6428
CB
276static void read_empty(unsigned const char *sha1, int verbose)
277{
278 int i = 0;
279 const char *args[7];
280
281 args[i++] = "read-tree";
282 if (verbose)
283 args[i++] = "-v";
284 args[i++] = "-m";
285 args[i++] = "-u";
286 args[i++] = EMPTY_TREE_SHA1_HEX;
287 args[i++] = sha1_to_hex(sha1);
288 args[i] = NULL;
289
290 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 291 die(_("read-tree failed"));
172b6428
CB
292}
293
1c7b76be
MV
294static void reset_hard(unsigned const char *sha1, int verbose)
295{
296 int i = 0;
297 const char *args[6];
298
299 args[i++] = "read-tree";
300 if (verbose)
301 args[i++] = "-v";
302 args[i++] = "--reset";
303 args[i++] = "-u";
304 args[i++] = sha1_to_hex(sha1);
305 args[i] = NULL;
306
307 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 308 die(_("read-tree failed"));
1c7b76be
MV
309}
310
52684310 311static void restore_state(const struct object_id *head,
312 const struct object_id *stash)
1c7b76be 313{
f285a2d7 314 struct strbuf sb = STRBUF_INIT;
1c7b76be
MV
315 const char *args[] = { "stash", "apply", NULL, NULL };
316
52684310 317 if (is_null_oid(stash))
1c7b76be
MV
318 return;
319
52684310 320 reset_hard(head->hash, 1);
1c7b76be 321
52684310 322 args[2] = oid_to_hex(stash);
1c7b76be
MV
323
324 /*
325 * It is OK to ignore error here, for example when there was
326 * nothing to restore.
327 */
328 run_command_v_opt(args, RUN_GIT_CMD);
329
330 strbuf_release(&sb);
331 refresh_cache(REFRESH_QUIET);
332}
333
334/* This is called when no merge was necessary. */
335static void finish_up_to_date(const char *msg)
336{
7f87aff2 337 if (verbosity >= 0)
bacec478 338 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
1c7b76be
MV
339 drop_save();
340}
341
4c57bd27 342static void squash_message(struct commit *commit, struct commit_list *remoteheads)
1c7b76be
MV
343{
344 struct rev_info rev;
f285a2d7 345 struct strbuf out = STRBUF_INIT;
1c7b76be 346 struct commit_list *j;
dd2e794a 347 struct pretty_print_context ctx = {0};
1c7b76be 348
bacec478 349 printf(_("Squash commit -- not updating HEAD\n"));
1c7b76be
MV
350
351 init_revisions(&rev, NULL);
352 rev.ignore_merges = 1;
353 rev.commit_format = CMIT_FMT_MEDIUM;
354
1c7b76be
MV
355 commit->object.flags |= UNINTERESTING;
356 add_pending_object(&rev, &commit->object, NULL);
357
358 for (j = remoteheads; j; j = j->next)
359 add_pending_object(&rev, &j->item->object, NULL);
360
361 setup_revisions(0, NULL, &rev, NULL);
362 if (prepare_revision_walk(&rev))
bacec478 363 die(_("revision walk setup failed"));
1c7b76be 364
dd2e794a
TR
365 ctx.abbrev = rev.abbrev;
366 ctx.date_mode = rev.date_mode;
6bf13944 367 ctx.fmt = rev.commit_format;
dd2e794a 368
1c7b76be
MV
369 strbuf_addstr(&out, "Squashed commit of the following:\n");
370 while ((commit = get_revision(&rev)) != NULL) {
371 strbuf_addch(&out, '\n');
372 strbuf_addf(&out, "commit %s\n",
f2fd0760 373 oid_to_hex(&commit->object.oid));
6bf13944 374 pretty_print_commit(&ctx, commit, &out);
1c7b76be 375 }
e78d5d49 376 write_file_buf(git_path_squash_msg(), out.buf, out.len);
1c7b76be
MV
377 strbuf_release(&out);
378}
379
894642f6 380static void finish(struct commit *head_commit,
4c57bd27 381 struct commit_list *remoteheads,
52684310 382 const struct object_id *new_head, const char *msg)
1c7b76be 383{
f285a2d7 384 struct strbuf reflog_message = STRBUF_INIT;
52684310 385 const struct object_id *head = &head_commit->object.oid;
1c7b76be 386
1c7b76be
MV
387 if (!msg)
388 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
389 else {
7f87aff2
TA
390 if (verbosity >= 0)
391 printf("%s\n", msg);
1c7b76be
MV
392 strbuf_addf(&reflog_message, "%s: %s",
393 getenv("GIT_REFLOG_ACTION"), msg);
394 }
395 if (squash) {
4c57bd27 396 squash_message(head_commit, remoteheads);
1c7b76be 397 } else {
7f87aff2 398 if (verbosity >= 0 && !merge_msg.len)
bacec478 399 printf(_("No merge message -- not updating HEAD\n"));
1c7b76be
MV
400 else {
401 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
402 update_ref(reflog_message.buf, "HEAD",
52684310 403 new_head->hash, head->hash, 0,
f4124112 404 UPDATE_REFS_DIE_ON_ERR);
1c7b76be
MV
405 /*
406 * We ignore errors in 'gc --auto', since the
407 * user should see them.
408 */
dcacb1b2 409 close_all_packs();
1c7b76be
MV
410 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
411 }
412 }
413 if (new_head && show_diffstat) {
414 struct diff_options opts;
415 diff_setup(&opts);
7a7159ac 416 opts.stat_width = -1; /* use full terminal width */
df44483a 417 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1c7b76be
MV
418 opts.output_format |=
419 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
420 opts.detect_rename = DIFF_DETECT_RENAME;
28452655 421 diff_setup_done(&opts);
66f414f8 422 diff_tree_oid(head, new_head, "", &opts);
1c7b76be
MV
423 diffcore_std(&opts);
424 diff_flush(&opts);
425 }
426
427 /* Run a post-merge hook */
15048f8a 428 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
1c7b76be
MV
429
430 strbuf_release(&reflog_message);
431}
432
433/* Get the name for the merge commit's message. */
434static void merge_name(const char *remote, struct strbuf *msg)
435{
ae8e4c9c 436 struct commit *remote_head;
52684310 437 struct object_id branch_head;
f285a2d7 438 struct strbuf buf = STRBUF_INIT;
c9717ee9 439 struct strbuf bname = STRBUF_INIT;
1c7b76be 440 const char *ptr;
751c5974 441 char *found_ref;
1c7b76be
MV
442 int len, early;
443
0e9f62da 444 strbuf_branchname(&bname, remote, 0);
a552de75 445 remote = bname.buf;
c9717ee9 446
52684310 447 oidclr(&branch_head);
ae8e4c9c 448 remote_head = get_merge_parent(remote);
1c7b76be 449 if (!remote_head)
bacec478 450 die(_("'%s' does not point to a commit"), remote);
1c7b76be 451
52684310 452 if (dwim_ref(remote, strlen(remote), branch_head.hash, &found_ref) > 0) {
59556548 453 if (starts_with(found_ref, "refs/heads/")) {
751c5974 454 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
52684310 455 oid_to_hex(&branch_head), remote);
751c5974
JK
456 goto cleanup;
457 }
59556548 458 if (starts_with(found_ref, "refs/tags/")) {
57b58db7 459 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
52684310 460 oid_to_hex(&branch_head), remote);
57b58db7
JH
461 goto cleanup;
462 }
59556548 463 if (starts_with(found_ref, "refs/remotes/")) {
13931236 464 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
52684310 465 oid_to_hex(&branch_head), remote);
69a8b7c7
JK
466 goto cleanup;
467 }
1c7b76be
MV
468 }
469
470 /* See if remote matches <name>^^^.. or <name>~<number> */
471 for (len = 0, ptr = remote + strlen(remote);
472 remote < ptr && ptr[-1] == '^';
473 ptr--)
474 len++;
475 if (len)
476 early = 1;
477 else {
478 early = 0;
479 ptr = strrchr(remote, '~');
480 if (ptr) {
481 int seen_nonzero = 0;
482
483 len++; /* count ~ */
484 while (*++ptr && isdigit(*ptr)) {
485 seen_nonzero |= (*ptr != '0');
486 len++;
487 }
488 if (*ptr)
489 len = 0; /* not ...~<number> */
490 else if (seen_nonzero)
491 early = 1;
492 else if (len == 1)
493 early = 1; /* "name~" is "name~1"! */
494 }
495 }
496 if (len) {
497 struct strbuf truname = STRBUF_INIT;
1016658d 498 strbuf_addf(&truname, "refs/heads/%s", remote);
9b6bf4d5 499 strbuf_setlen(&truname, truname.len - len);
c6893323 500 if (ref_exists(truname.buf)) {
1c7b76be
MV
501 strbuf_addf(msg,
502 "%s\t\tbranch '%s'%s of .\n",
c368dde9 503 oid_to_hex(&remote_head->object.oid),
9b6bf4d5 504 truname.buf + 11,
1c7b76be 505 (early ? " (early part)" : ""));
c9717ee9
JH
506 strbuf_release(&truname);
507 goto cleanup;
1c7b76be 508 }
1016658d 509 strbuf_release(&truname);
1c7b76be 510 }
2d1495fe
JH
511
512 if (remote_head->util) {
513 struct merge_remote_desc *desc;
514 desc = merge_remote_util(remote_head);
515 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
516 strbuf_addf(msg, "%s\t\t%s '%s'\n",
c368dde9 517 oid_to_hex(&desc->obj->oid),
2d1495fe
JH
518 typename(desc->obj->type),
519 remote);
520 goto cleanup;
521 }
522 }
523
1c7b76be 524 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
c368dde9 525 oid_to_hex(&remote_head->object.oid), remote);
c9717ee9
JH
526cleanup:
527 strbuf_release(&buf);
528 strbuf_release(&bname);
1c7b76be
MV
529}
530
0d8fc3ef
JH
531static void parse_branch_merge_options(char *bmo)
532{
533 const char **argv;
534 int argc;
535
536 if (!bmo)
537 return;
538 argc = split_cmdline(bmo, &argv);
539 if (argc < 0)
c7fe5b61
JH
540 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
541 split_cmdline_strerror(argc));
2756ca43 542 REALLOC_ARRAY(argv, argc + 2);
f331ab9d 543 MOVE_ARRAY(argv + 1, argv, argc + 1);
0d8fc3ef
JH
544 argc++;
545 argv[0] = "branch.*.mergeoptions";
546 parse_options(argc, argv, NULL, builtin_merge_options,
547 builtin_merge_usage, 0);
548 free(argv);
549}
550
186458b1 551static int git_merge_config(const char *k, const char *v, void *cb)
1c7b76be 552{
898eacd8
JH
553 int status;
554
59556548
CC
555 if (branch && starts_with(k, "branch.") &&
556 starts_with(k + 7, branch) &&
1c7b76be 557 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
0d8fc3ef
JH
558 free(branch_mergeoptions);
559 branch_mergeoptions = xstrdup(v);
560 return 0;
1c7b76be
MV
561 }
562
563 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
564 show_diffstat = git_config_bool(k, v);
565 else if (!strcmp(k, "pull.twohead"))
566 return git_config_string(&pull_twohead, k, v);
567 else if (!strcmp(k, "pull.octopus"))
568 return git_config_string(&pull_octopus, k, v);
7610fa57
JN
569 else if (!strcmp(k, "merge.renormalize"))
570 option_renormalize = git_config_bool(k, v);
898eacd8 571 else if (!strcmp(k, "merge.ff")) {
89576613 572 int boolval = git_parse_maybe_bool(v);
f23e8dec 573 if (0 <= boolval) {
a54841e9 574 fast_forward = boolval ? FF_ALLOW : FF_NO;
f23e8dec 575 } else if (v && !strcmp(v, "only")) {
a54841e9 576 fast_forward = FF_ONLY;
f23e8dec
JH
577 } /* do not barf on values from future versions of git */
578 return 0;
93e535a5
JH
579 } else if (!strcmp(k, "merge.defaulttoupstream")) {
580 default_to_upstream = git_config_bool(k, v);
581 return 0;
d95bfb12
NV
582 } else if (!strcmp(k, "commit.gpgsign")) {
583 sign_commit = git_config_bool(k, v) ? "" : NULL;
584 return 0;
96e9420c 585 }
ba3c69a9 586
898eacd8 587 status = fmt_merge_msg_config(k, v, cb);
5de89d3a
JH
588 if (status)
589 return status;
ba3c69a9 590 status = git_gpg_config(k, v, NULL);
898eacd8
JH
591 if (status)
592 return status;
1c7b76be
MV
593 return git_diff_ui_config(k, v, cb);
594}
595
52684310 596static int read_tree_trivial(struct object_id *common, struct object_id *head,
597 struct object_id *one)
1c7b76be
MV
598{
599 int i, nr_trees = 0;
600 struct tree *trees[MAX_UNPACK_TREES];
601 struct tree_desc t[MAX_UNPACK_TREES];
602 struct unpack_trees_options opts;
603
604 memset(&opts, 0, sizeof(opts));
605 opts.head_idx = 2;
606 opts.src_index = &the_index;
607 opts.dst_index = &the_index;
608 opts.update = 1;
609 opts.verbose_update = 1;
610 opts.trivial_merges_only = 1;
611 opts.merge = 1;
a9dbc179 612 trees[nr_trees] = parse_tree_indirect(common);
1c7b76be
MV
613 if (!trees[nr_trees++])
614 return -1;
a9dbc179 615 trees[nr_trees] = parse_tree_indirect(head);
1c7b76be
MV
616 if (!trees[nr_trees++])
617 return -1;
a9dbc179 618 trees[nr_trees] = parse_tree_indirect(one);
1c7b76be
MV
619 if (!trees[nr_trees++])
620 return -1;
621 opts.fn = threeway_merge;
622 cache_tree_free(&active_cache_tree);
623 for (i = 0; i < nr_trees; i++) {
624 parse_tree(trees[i]);
625 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
626 }
627 if (unpack_trees(nr_trees, t, &opts))
628 return -1;
629 return 0;
630}
631
52684310 632static void write_tree_trivial(struct object_id *oid)
1c7b76be 633{
52684310 634 if (write_cache_as_tree(oid->hash, 0, NULL))
bacec478 635 die(_("git write-tree failed to write a tree"));
1c7b76be
MV
636}
637
3f9083cd 638static int try_merge_strategy(const char *strategy, struct commit_list *common,
4c57bd27 639 struct commit_list *remoteheads,
b4391657 640 struct commit *head)
3f9083cd 641{
daccee38 642 static struct lock_file lock;
b4391657 643 const char *head_arg = "HEAD";
668f26ff 644
b3e83cc7 645 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
668f26ff
MV
646 refresh_cache(REFRESH_QUIET);
647 if (active_cache_changed &&
daccee38 648 write_locked_index(&the_index, &lock, COMMIT_LOCK))
bacec478 649 return error(_("Unable to write index."));
daccee38 650 rollback_lock_file(&lock);
1c7b76be 651
18668f53 652 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
3f9083cd 653 int clean, x;
18668f53 654 struct commit *result;
18668f53
MV
655 struct commit_list *reversed = NULL;
656 struct merge_options o;
3f9083cd 657 struct commit_list *j;
18668f53
MV
658
659 if (remoteheads->next) {
bacec478 660 error(_("Not handling anything other than two heads merge."));
18668f53
MV
661 return 2;
662 }
663
664 init_merge_options(&o);
665 if (!strcmp(strategy, "subtree"))
85e51b78 666 o.subtree_shift = "";
8cc5b290 667
7610fa57 668 o.renormalize = option_renormalize;
99bfc669
JK
669 o.show_rename_progress =
670 show_progress == -1 ? isatty(2) : show_progress;
7610fa57 671
635a7bb1
JN
672 for (x = 0; x < xopts_nr; x++)
673 if (parse_merge_opt(&o, xopts[x]))
bacec478 674 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
18668f53
MV
675
676 o.branch1 = head_arg;
ae8e4c9c 677 o.branch2 = merge_remote_util(remoteheads->item)->name;
18668f53
MV
678
679 for (j = common; j; j = j->next)
680 commit_list_insert(j->item, &reversed);
681
b3e83cc7 682 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
894642f6 683 clean = merge_recursive(&o, head,
18668f53 684 remoteheads->item, reversed, &result);
f241ff0d
JS
685 if (clean < 0)
686 exit(128);
18668f53 687 if (active_cache_changed &&
daccee38 688 write_locked_index(&the_index, &lock, COMMIT_LOCK))
bacec478 689 die (_("unable to write %s"), get_index_file());
daccee38 690 rollback_lock_file(&lock);
18668f53
MV
691 return clean ? 0 : 1;
692 } else {
67ac1e1d
JN
693 return try_merge_command(strategy, xopts_nr, xopts,
694 common, head_arg, remoteheads);
18668f53 695 }
1c7b76be
MV
696}
697
698static void count_diff_files(struct diff_queue_struct *q,
699 struct diff_options *opt, void *data)
700{
701 int *count = data;
702
703 (*count) += q->nr;
704}
705
706static int count_unmerged_entries(void)
707{
1c7b76be
MV
708 int i, ret = 0;
709
be6ff819
JH
710 for (i = 0; i < active_nr; i++)
711 if (ce_stage(active_cache[i]))
1c7b76be
MV
712 ret++;
713
714 return ret;
715}
716
1c7b76be
MV
717static void add_strategies(const char *string, unsigned attr)
718{
02a8cfa4
RS
719 int i;
720
721 if (string) {
722 struct string_list list = STRING_LIST_INIT_DUP;
723 struct string_list_item *item;
724 string_list_split(&list, string, ' ', -1);
725 for_each_string_list_item(item, &list)
726 append_strategy(get_strategy(item->string));
727 string_list_clear(&list, 0);
1c7b76be
MV
728 return;
729 }
730 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
731 if (all_strategy[i].attr & attr)
732 append_strategy(&all_strategy[i]);
733
734}
735
66f4b98a 736static void read_merge_msg(struct strbuf *msg)
65969d43 737{
f932729c 738 const char *filename = git_path_merge_msg();
66f4b98a 739 strbuf_reset(msg);
418c9b17
JN
740 if (strbuf_read_file(msg, filename, 0) < 0)
741 die_errno(_("Could not read from '%s'"), filename);
65969d43
JS
742}
743
4c57bd27
JH
744static void write_merge_state(struct commit_list *);
745static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
65969d43 746{
66f4b98a
JS
747 if (err_msg)
748 error("%s", err_msg);
749 fprintf(stderr,
750 _("Not committing merge; use 'git commit' to complete the merge.\n"));
4c57bd27 751 write_merge_state(remoteheads);
66f4b98a
JS
752 exit(1);
753}
754
f26af3fc
TR
755static const char merge_editor_comment[] =
756N_("Please enter a commit message to explain why this merge is necessary,\n"
757 "especially if it merges an updated upstream into a topic branch.\n"
758 "\n"
eff80a9f 759 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
f26af3fc
TR
760 "the commit.\n");
761
9d89b355 762static void write_merge_heads(struct commit_list *);
4c57bd27 763static void prepare_to_commit(struct commit_list *remoteheads)
66f4b98a
JS
764{
765 struct strbuf msg = STRBUF_INIT;
766 strbuf_addbuf(&msg, &merge_msg);
767 strbuf_addch(&msg, '\n');
62dc42b9
MG
768 if (squash)
769 BUG("the control must not reach here under --squash");
f26af3fc 770 if (0 < option_edit)
eff80a9f 771 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
14d01b4f
ŁG
772 if (signoff)
773 append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
9d89b355 774 write_merge_heads(remoteheads);
e78d5d49 775 write_file_buf(git_path_merge_msg(), msg.buf, msg.len);
0a3beb0e 776 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
f932729c 777 git_path_merge_msg(), "merge", NULL))
3e4141d0 778 abort_commit(remoteheads, NULL);
f8246281 779 if (0 < option_edit) {
f932729c 780 if (launch_editor(git_path_merge_msg(), NULL, NULL))
4c57bd27 781 abort_commit(remoteheads, NULL);
66f4b98a
JS
782 }
783 read_merge_msg(&msg);
63af4a84 784 strbuf_stripspace(&msg, 0 < option_edit);
66f4b98a 785 if (!msg.len)
4c57bd27 786 abort_commit(remoteheads, _("Empty commit message."));
66f4b98a
JS
787 strbuf_release(&merge_msg);
788 strbuf_addbuf(&merge_msg, &msg);
789 strbuf_release(&msg);
65969d43
JS
790}
791
4c57bd27 792static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
1c7b76be 793{
52684310 794 struct object_id result_tree, result_commit;
910a09a7 795 struct commit_list *parents, **pptr = &parents;
40d71940
EN
796 static struct lock_file lock;
797
b3e83cc7 798 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
40d71940
EN
799 refresh_cache(REFRESH_QUIET);
800 if (active_cache_changed &&
801 write_locked_index(&the_index, &lock, COMMIT_LOCK))
802 return error(_("Unable to write index."));
803 rollback_lock_file(&lock);
1c7b76be 804
52684310 805 write_tree_trivial(&result_tree);
157efde1 806 printf(_("Wonderful.\n"));
910a09a7
RS
807 pptr = commit_list_append(head, pptr);
808 pptr = commit_list_append(remoteheads->item, pptr);
4c57bd27 809 prepare_to_commit(remoteheads);
52684310 810 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree.hash, parents,
811 result_commit.hash, NULL, sign_commit))
6b3c4c05 812 die(_("failed to write commit object"));
52684310 813 finish(head, remoteheads, &result_commit, "In-index merge");
1c7b76be
MV
814 drop_save();
815 return 0;
816}
817
894642f6 818static int finish_automerge(struct commit *head,
e78cbf8c 819 int head_subsumed,
894642f6 820 struct commit_list *common,
4c57bd27 821 struct commit_list *remoteheads,
52684310 822 struct object_id *result_tree,
1c7b76be
MV
823 const char *wt_strategy)
824{
e78cbf8c 825 struct commit_list *parents = NULL;
1c7b76be 826 struct strbuf buf = STRBUF_INIT;
52684310 827 struct object_id result_commit;
1c7b76be
MV
828
829 free_commit_list(common);
e78cbf8c 830 parents = remoteheads;
a54841e9 831 if (!head_subsumed || fast_forward == FF_NO)
894642f6 832 commit_list_insert(head, &parents);
1c7b76be 833 strbuf_addch(&merge_msg, '\n');
4c57bd27 834 prepare_to_commit(remoteheads);
52684310 835 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree->hash, parents,
836 result_commit.hash, NULL, sign_commit))
6b3c4c05 837 die(_("failed to write commit object"));
f23101bf 838 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
52684310 839 finish(head, remoteheads, &result_commit, buf.buf);
1c7b76be
MV
840 strbuf_release(&buf);
841 drop_save();
842 return 0;
843}
844
08e3ce5a 845static int suggest_conflicts(void)
1c7b76be 846{
418c9b17 847 const char *filename;
1c7b76be 848 FILE *fp;
75c961b7 849 struct strbuf msgbuf = STRBUF_INIT;
1c7b76be 850
f932729c 851 filename = git_path_merge_msg();
23a9e071 852 fp = xfopen(filename, "a");
75c961b7
JH
853
854 append_conflicts_hint(&msgbuf);
855 fputs(msgbuf.buf, fp);
8d025b7c 856 strbuf_release(&msgbuf);
1c7b76be 857 fclose(fp);
cb6020bb 858 rerere(allow_rerere_auto);
bacec478
ÆAB
859 printf(_("Automatic merge failed; "
860 "fix conflicts and then commit the result.\n"));
1c7b76be
MV
861 return 1;
862}
863
1c7b76be
MV
864static int evaluate_result(void)
865{
866 int cnt = 0;
867 struct rev_info rev;
868
1c7b76be
MV
869 /* Check how many files differ. */
870 init_revisions(&rev, "");
871 setup_revisions(0, NULL, &rev, NULL);
872 rev.diffopt.output_format |=
873 DIFF_FORMAT_CALLBACK;
874 rev.diffopt.format_callback = count_diff_files;
875 rev.diffopt.format_callback_data = &cnt;
876 run_diff_files(&rev, 0);
877
878 /*
879 * Check how many unmerged entries are
880 * there.
881 */
882 cnt += count_unmerged_entries();
883
884 return cnt;
885}
886
93e535a5 887/*
d6ac1d21 888 * Pretend as if the user told us to merge with the remote-tracking
93e535a5
JH
889 * branch we have for the upstream of the current branch
890 */
891static int setup_with_upstream(const char ***argv)
892{
893 struct branch *branch = branch_get(NULL);
894 int i;
895 const char **args;
896
897 if (!branch)
c7f426d4 898 die(_("No current branch."));
9e3751d4 899 if (!branch->remote_name)
c7f426d4 900 die(_("No remote for the current branch."));
93e535a5 901 if (!branch->merge_nr)
c7f426d4 902 die(_("No default upstream defined for the current branch."));
93e535a5 903
50a6c8ef 904 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
93e535a5
JH
905 for (i = 0; i < branch->merge_nr; i++) {
906 if (!branch->merge[i]->dst)
d6ac1d21 907 die(_("No remote-tracking branch for %s from %s"),
93e535a5
JH
908 branch->merge[i]->src, branch->remote_name);
909 args[i] = branch->merge[i]->dst;
910 }
911 args[i] = NULL;
912 *argv = args;
913 return i;
914}
915
8e6a6bb3 916static void write_merge_heads(struct commit_list *remoteheads)
66f4b98a 917{
66f4b98a
JS
918 struct commit_list *j;
919 struct strbuf buf = STRBUF_INIT;
920
274a5c06 921 for (j = remoteheads; j; j = j->next) {
f2fd0760 922 struct object_id *oid;
274a5c06
JH
923 struct commit *c = j->item;
924 if (c->util && merge_remote_util(c)->obj) {
f2fd0760 925 oid = &merge_remote_util(c)->obj->oid;
274a5c06 926 } else {
f2fd0760 927 oid = &c->object.oid;
274a5c06 928 }
f2fd0760 929 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
274a5c06 930 }
e78d5d49 931 write_file_buf(git_path_merge_head(), buf.buf, buf.len);
418c9b17 932
66f4b98a 933 strbuf_reset(&buf);
a54841e9 934 if (fast_forward == FF_NO)
a22ae753 935 strbuf_addstr(&buf, "no-ff");
e78d5d49 936 write_file_buf(git_path_merge_mode(), buf.buf, buf.len);
66f4b98a
JS
937}
938
8e6a6bb3
MG
939static void write_merge_state(struct commit_list *remoteheads)
940{
941 write_merge_heads(remoteheads);
942 strbuf_addch(&merge_msg, '\n');
943 write_file_buf(git_path_merge_msg(), merge_msg.buf, merge_msg.len);
944}
945
f8246281
JH
946static int default_edit_option(void)
947{
948 static const char name[] = "GIT_MERGE_AUTOEDIT";
949 const char *e = getenv(name);
950 struct stat st_stdin, st_stdout;
951
952 if (have_message)
953 /* an explicit -m msg without --[no-]edit */
954 return 0;
955
956 if (e) {
89576613 957 int v = git_parse_maybe_bool(e);
f8246281 958 if (v < 0)
bef4830e 959 die(_("Bad value '%s' in environment '%s'"), e, name);
f8246281
JH
960 return v;
961 }
962
963 /* Use editor if stdin and stdout are the same and is a tty */
964 return (!fstat(0, &st_stdin) &&
965 !fstat(1, &st_stdout) &&
d46f476c 966 isatty(0) && isatty(1) &&
f8246281
JH
967 st_stdin.st_dev == st_stdout.st_dev &&
968 st_stdin.st_ino == st_stdout.st_ino &&
969 st_stdin.st_mode == st_stdout.st_mode);
970}
971
34349dbf
JH
972static struct commit_list *reduce_parents(struct commit *head_commit,
973 int *head_subsumed,
974 struct commit_list *remoteheads)
b5d887f9 975{
e510ab89 976 struct commit_list *parents, **remotes;
b5d887f9 977
0b10b8a3
JH
978 /*
979 * Is the current HEAD reachable from another commit being
980 * merged? If so we do not want to record it as a parent of
981 * the resulting merge, unless --no-ff is given. We will flip
982 * this variable to 0 when we find HEAD among the independent
983 * tips being merged.
984 */
985 *head_subsumed = 1;
e78cbf8c 986
0b10b8a3 987 /* Find what parents to record by checking independent ones. */
e78cbf8c
JH
988 parents = reduce_heads(remoteheads);
989
e510ab89
RS
990 remoteheads = NULL;
991 remotes = &remoteheads;
992 while (parents) {
993 struct commit *commit = pop_commit(&parents);
e78cbf8c
JH
994 if (commit == head_commit)
995 *head_subsumed = 0;
996 else
997 remotes = &commit_list_insert(commit, remotes)->next;
998 }
b5d887f9
JH
999 return remoteheads;
1000}
f8246281 1001
52fecab2
JH
1002static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1003{
1004 struct fmt_merge_msg_opts opts;
1005
1006 memset(&opts, 0, sizeof(opts));
1007 opts.add_title = !have_message;
1008 opts.shortlog_len = shortlog_len;
1009 opts.credit_people = (0 < option_edit);
1010
1011 fmt_merge_msg(merge_names, merge_msg, &opts);
1012 if (merge_msg->len)
1013 strbuf_setlen(merge_msg, merge_msg->len - 1);
1014}
1015
74e8bc59
JH
1016static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1017{
1018 const char *filename;
1019 int fd, pos, npos;
1020 struct strbuf fetch_head_file = STRBUF_INIT;
1021
1022 if (!merge_names)
1023 merge_names = &fetch_head_file;
1024
f932729c 1025 filename = git_path_fetch_head();
74e8bc59
JH
1026 fd = open(filename, O_RDONLY);
1027 if (fd < 0)
1028 die_errno(_("could not open '%s' for reading"), filename);
1029
1030 if (strbuf_read(merge_names, fd, 0) < 0)
1031 die_errno(_("could not read '%s'"), filename);
1032 if (close(fd) < 0)
1033 die_errno(_("could not close '%s'"), filename);
1034
1035 for (pos = 0; pos < merge_names->len; pos = npos) {
52684310 1036 struct object_id oid;
74e8bc59
JH
1037 char *ptr;
1038 struct commit *commit;
1039
1040 ptr = strchr(merge_names->buf + pos, '\n');
1041 if (ptr)
1042 npos = ptr - merge_names->buf + 1;
1043 else
1044 npos = merge_names->len;
1045
52684310 1046 if (npos - pos < GIT_SHA1_HEXSZ + 2 ||
1047 get_oid_hex(merge_names->buf + pos, &oid))
74e8bc59 1048 commit = NULL; /* bad */
52684310 1049 else if (memcmp(merge_names->buf + pos + GIT_SHA1_HEXSZ, "\t\t", 2))
74e8bc59
JH
1050 continue; /* not-for-merge */
1051 else {
52684310 1052 char saved = merge_names->buf[pos + GIT_SHA1_HEXSZ];
1053 merge_names->buf[pos + GIT_SHA1_HEXSZ] = '\0';
74e8bc59 1054 commit = get_merge_parent(merge_names->buf + pos);
52684310 1055 merge_names->buf[pos + GIT_SHA1_HEXSZ] = saved;
74e8bc59
JH
1056 }
1057 if (!commit) {
1058 if (ptr)
1059 *ptr = '\0';
bef4830e 1060 die(_("not something we can merge in %s: %s"),
74e8bc59
JH
1061 filename, merge_names->buf + pos);
1062 }
1063 remotes = &commit_list_insert(commit, remotes)->next;
1064 }
1065
1066 if (merge_names == &fetch_head_file)
1067 strbuf_release(&fetch_head_file);
1068}
1069
34349dbf
JH
1070static struct commit_list *collect_parents(struct commit *head_commit,
1071 int *head_subsumed,
1cf32f4d
JH
1072 int argc, const char **argv,
1073 struct strbuf *merge_msg)
34349dbf
JH
1074{
1075 int i;
1076 struct commit_list *remoteheads = NULL;
1077 struct commit_list **remotes = &remoteheads;
77038015
JH
1078 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1079
1080 if (merge_msg && (!have_message || shortlog_len))
1081 autogen = &merge_names;
34349dbf
JH
1082
1083 if (head_commit)
1084 remotes = &commit_list_insert(head_commit, remotes)->next;
34349dbf 1085
74e8bc59
JH
1086 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1087 handle_fetch_head(remotes, autogen);
1088 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1089 } else {
1090 for (i = 0; i < argc; i++) {
1091 struct commit *commit = get_merge_parent(argv[i]);
1092 if (!commit)
1093 help_unknown_ref(argv[i], "merge",
bef4830e 1094 _("not something we can merge"));
74e8bc59
JH
1095 remotes = &commit_list_insert(commit, remotes)->next;
1096 }
1097 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1098 if (autogen) {
1099 struct commit_list *p;
1100 for (p = remoteheads; p; p = p->next)
1101 merge_name(merge_remote_util(p->item)->name, autogen);
1102 }
1103 }
1cf32f4d 1104
77038015 1105 if (autogen) {
77038015
JH
1106 prepare_merge_message(autogen, merge_msg);
1107 strbuf_release(autogen);
1cf32f4d
JH
1108 }
1109
1110 return remoteheads;
34349dbf
JH
1111}
1112
1c7b76be
MV
1113int cmd_merge(int argc, const char **argv, const char *prefix)
1114{
52684310 1115 struct object_id result_tree, stash, head_oid;
894642f6 1116 struct commit *head_commit;
f285a2d7 1117 struct strbuf buf = STRBUF_INIT;
17377b62 1118 int i, ret = 0, head_subsumed;
1c7b76be
MV
1119 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1120 struct commit_list *common = NULL;
1121 const char *best_strategy = NULL, *wt_strategy = NULL;
b5d887f9 1122 struct commit_list *remoteheads, *p;
96ec7b1e 1123 void *branch_to_free;
367ff694 1124 int orig_argc = argc;
1c7b76be 1125
da53eec6
NTND
1126 if (argc == 2 && !strcmp(argv[1], "-h"))
1127 usage_with_options(builtin_merge_usage, builtin_merge_options);
1c7b76be
MV
1128
1129 /*
1130 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1131 * current branch.
1132 */
52684310 1133 branch = branch_to_free = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
de3ce210
RS
1134 if (branch)
1135 skip_prefix(branch, "refs/heads/", &branch);
52684310 1136 if (!branch || is_null_oid(&head_oid))
894642f6 1137 head_commit = NULL;
baf18fc2 1138 else
bc83266a 1139 head_commit = lookup_commit_or_die(&head_oid, "HEAD");
1c7b76be 1140
5404c116 1141 init_diff_ui_defaults();
1c7b76be
MV
1142 git_config(git_merge_config, NULL);
1143
0d8fc3ef
JH
1144 if (branch_mergeoptions)
1145 parse_branch_merge_options(branch_mergeoptions);
37782920 1146 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1c7b76be 1147 builtin_merge_usage, 0);
898eacd8
JH
1148 if (shortlog_len < 0)
1149 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
2a22c1b3 1150
99bfc669
JK
1151 if (verbosity < 0 && show_progress == -1)
1152 show_progress = 0;
1153
35d2fffd
JH
1154 if (abort_current_merge) {
1155 int nargc = 2;
1156 const char *nargv[] = {"reset", "--merge", NULL};
1157
042e290d 1158 if (orig_argc != 2)
c7d227df 1159 usage_msg_opt(_("--abort expects no arguments"),
042e290d
CP
1160 builtin_merge_usage, builtin_merge_options);
1161
f932729c 1162 if (!file_exists(git_path_merge_head()))
bacec478 1163 die(_("There is no merge to abort (MERGE_HEAD missing)."));
35d2fffd
JH
1164
1165 /* Invoke 'git reset --merge' */
d5a35c11
NTND
1166 ret = cmd_reset(nargc, nargv, prefix);
1167 goto done;
35d2fffd
JH
1168 }
1169
367ff694
CP
1170 if (continue_current_merge) {
1171 int nargc = 1;
1172 const char *nargv[] = {"commit", NULL};
1173
1174 if (orig_argc != 2)
c7d227df 1175 usage_msg_opt(_("--continue expects no arguments"),
367ff694
CP
1176 builtin_merge_usage, builtin_merge_options);
1177
1178 if (!file_exists(git_path_merge_head()))
1179 die(_("There is no merge in progress (MERGE_HEAD missing)."));
1180
1181 /* Invoke 'git commit' */
1182 ret = cmd_commit(nargc, nargv, prefix);
1183 goto done;
1184 }
1185
2a22c1b3
JH
1186 if (read_cache_unmerged())
1187 die_resolve_conflict("merge");
1188
f932729c 1189 if (file_exists(git_path_merge_head())) {
2a22c1b3
JH
1190 /*
1191 * There is no unmerged entry, don't advise 'git
1192 * add/rm <file>', just 'git commit'.
1193 */
1194 if (advice_resolve_conflict)
bacec478 1195 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
ad5fe377 1196 "Please, commit your changes before you merge."));
2a22c1b3 1197 else
bacec478 1198 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
2a22c1b3 1199 }
f932729c 1200 if (file_exists(git_path_cherry_pick_head())) {
d7e5c0cb 1201 if (advice_resolve_conflict)
f68f1801 1202 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
ad5fe377 1203 "Please, commit your changes before you merge."));
d7e5c0cb 1204 else
f68f1801 1205 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
2a22c1b3
JH
1206 }
1207 resolve_undo_clear();
1208
7f87aff2
TA
1209 if (verbosity < 0)
1210 show_diffstat = 0;
1c7b76be
MV
1211
1212 if (squash) {
a54841e9 1213 if (fast_forward == FF_NO)
bacec478 1214 die(_("You cannot combine --squash with --no-ff."));
1c7b76be
MV
1215 option_commit = 0;
1216 }
1217
00c7e7e7
JH
1218 if (!argc) {
1219 if (default_to_upstream)
1220 argc = setup_with_upstream(&argv);
1221 else
1222 die(_("No commit specified and merge.defaultToUpstream not set."));
1223 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1224 argv[0] = "@{-1}";
4e8115ff 1225 }
00c7e7e7 1226
1c7b76be
MV
1227 if (!argc)
1228 usage_with_options(builtin_merge_usage,
1229 builtin_merge_options);
1230
1faac1ce 1231 if (!head_commit) {
1c7b76be
MV
1232 /*
1233 * If the merged head is a valid one there is no reason
1234 * to forbid "git merge" into a branch yet to be born.
1235 * We do the same for "git pull".
1236 */
52684310 1237 struct object_id *remote_head_oid;
4be636f4 1238 if (squash)
bacec478 1239 die(_("Squash commit into empty head not supported yet"));
a54841e9 1240 if (fast_forward == FF_NO)
bacec478
ÆAB
1241 die(_("Non-fast-forward commit does not make sense into "
1242 "an empty head"));
1cf32f4d
JH
1243 remoteheads = collect_parents(head_commit, &head_subsumed,
1244 argc, argv, NULL);
b84e65d4 1245 if (!remoteheads)
bacec478 1246 die(_("%s - not something we can merge"), argv[0]);
eaa4e59c
JH
1247 if (remoteheads->next)
1248 die(_("Can merge only exactly one commit into empty head"));
52684310 1249 remote_head_oid = &remoteheads->item->object.oid;
1250 read_empty(remote_head_oid->hash, 0);
1251 update_ref("initial pull", "HEAD", remote_head_oid->hash,
f4124112 1252 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
d5a35c11 1253 goto done;
1faac1ce 1254 }
1c7b76be 1255
1faac1ce 1256 /*
b4391657
JH
1257 * All the rest are the commits being merged; prepare
1258 * the standard merge summary message to be appended
1259 * to the given message.
1faac1ce 1260 */
b4391657
JH
1261 remoteheads = collect_parents(head_commit, &head_subsumed,
1262 argc, argv, &merge_msg);
1c7b76be 1263
894642f6 1264 if (!head_commit || !argc)
1c7b76be
MV
1265 usage_with_options(builtin_merge_usage,
1266 builtin_merge_options);
1267
efed0022
SG
1268 if (verify_signatures) {
1269 for (p = remoteheads; p; p = p->next) {
1270 struct commit *commit = p->item;
dc01505f 1271 char hex[GIT_MAX_HEXSZ + 1];
efed0022
SG
1272 struct signature_check signature_check;
1273 memset(&signature_check, 0, sizeof(signature_check));
1274
1275 check_commit_signature(commit, &signature_check);
1276
ed1c9977 1277 find_unique_abbrev_r(hex, commit->object.oid.hash, DEFAULT_ABBREV);
efed0022
SG
1278 switch (signature_check.result) {
1279 case 'G':
1280 break;
eb307ae7
SG
1281 case 'U':
1282 die(_("Commit %s has an untrusted GPG signature, "
1283 "allegedly by %s."), hex, signature_check.signer);
efed0022
SG
1284 case 'B':
1285 die(_("Commit %s has a bad GPG signature "
1286 "allegedly by %s."), hex, signature_check.signer);
1287 default: /* 'N' */
1288 die(_("Commit %s does not have a GPG signature."), hex);
1289 }
1290 if (verbosity >= 0 && signature_check.result == 'G')
1291 printf(_("Commit %s has a good GPG signature by %s\n"),
1292 hex, signature_check.signer);
1293
01e57b5d 1294 signature_check_clear(&signature_check);
efed0022
SG
1295 }
1296 }
1297
1c7b76be 1298 strbuf_addstr(&buf, "merge");
b5d887f9
JH
1299 for (p = remoteheads; p; p = p->next)
1300 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1c7b76be
MV
1301 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1302 strbuf_reset(&buf);
1303
b5d887f9
JH
1304 for (p = remoteheads; p; p = p->next) {
1305 struct commit *commit = p->item;
ae8e4c9c 1306 strbuf_addf(&buf, "GITHEAD_%s",
c368dde9 1307 oid_to_hex(&commit->object.oid));
b5d887f9 1308 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1c7b76be 1309 strbuf_reset(&buf);
a54841e9 1310 if (fast_forward != FF_ONLY &&
b5c9f1c1 1311 merge_remote_util(commit) &&
fab47d05 1312 merge_remote_util(commit)->obj &&
d82829b6 1313 merge_remote_util(commit)->obj->type == OBJ_TAG)
a54841e9 1314 fast_forward = FF_NO;
1c7b76be
MV
1315 }
1316
f8246281
JH
1317 if (option_edit < 0)
1318 option_edit = default_edit_option();
1319
1c7b76be 1320 if (!use_strategies) {
e78cbf8c
JH
1321 if (!remoteheads)
1322 ; /* already up-to-date */
1323 else if (!remoteheads->next)
1c7b76be
MV
1324 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1325 else
1326 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1327 }
1328
1329 for (i = 0; i < use_strategies_nr; i++) {
1330 if (use_strategies[i]->attr & NO_FAST_FORWARD)
a54841e9 1331 fast_forward = FF_NO;
1c7b76be
MV
1332 if (use_strategies[i]->attr & NO_TRIVIAL)
1333 allow_trivial = 0;
1334 }
1335
e78cbf8c
JH
1336 if (!remoteheads)
1337 ; /* already up-to-date */
1338 else if (!remoteheads->next)
2ce406cc 1339 common = get_merge_bases(head_commit, remoteheads->item);
1c7b76be
MV
1340 else {
1341 struct commit_list *list = remoteheads;
894642f6 1342 commit_list_insert(head_commit, &list);
1c7b76be
MV
1343 common = get_octopus_merge_bases(list);
1344 free(list);
1345 }
1346
ed1c9977 1347 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.oid.hash,
f4124112 1348 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1c7b76be 1349
e379fdf3
JH
1350 if (remoteheads && !common) {
1351 /* No common ancestors found. */
1352 if (!allow_unrelated_histories)
1353 die(_("refusing to merge unrelated histories"));
1354 /* otherwise, we need a real merge. */
1355 } else if (!remoteheads ||
e78cbf8c
JH
1356 (!remoteheads->next && !common->next &&
1357 common->item == remoteheads->item)) {
1c7b76be
MV
1358 /*
1359 * If head can reach all the merge then we are up to date.
1360 * but first the most common case of merging one remote.
1361 */
bef4830e 1362 finish_up_to_date(_("Already up-to-date."));
d5a35c11 1363 goto done;
a54841e9 1364 } else if (fast_forward != FF_NO && !remoteheads->next &&
1c7b76be 1365 !common->next &&
c368dde9 1366 !oidcmp(&common->item->object.oid, &head_commit->object.oid)) {
1c7b76be 1367 /* Again the most common case of merging one remote. */
f285a2d7 1368 struct strbuf msg = STRBUF_INIT;
ae8e4c9c 1369 struct commit *commit;
1c7b76be 1370
d59f765a 1371 if (verbosity >= 0) {
ef2ed501
JK
1372 printf(_("Updating %s..%s\n"),
1373 find_unique_abbrev(head_commit->object.oid.hash,
1374 DEFAULT_ABBREV),
1375 find_unique_abbrev(remoteheads->item->object.oid.hash,
1376 DEFAULT_ABBREV));
d59f765a 1377 }
a75d7b54 1378 strbuf_addstr(&msg, "Fast-forward");
1c7b76be
MV
1379 if (have_message)
1380 strbuf_addstr(&msg,
1381 " (no commit created; -m option ignored)");
ae8e4c9c 1382 commit = remoteheads->item;
b7f7c079 1383 if (!commit) {
d5a35c11
NTND
1384 ret = 1;
1385 goto done;
1386 }
1c7b76be 1387
f06e90da 1388 if (checkout_fast_forward(&head_commit->object.oid,
1389 &commit->object.oid,
db699a8a 1390 overwrite_ignore)) {
d5a35c11
NTND
1391 ret = 1;
1392 goto done;
1393 }
1c7b76be 1394
52684310 1395 finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
1c7b76be 1396 drop_save();
d5a35c11 1397 goto done;
1c7b76be
MV
1398 } else if (!remoteheads->next && common->next)
1399 ;
1400 /*
a75d7b54 1401 * We are not doing octopus and not fast-forward. Need
1c7b76be
MV
1402 * a real merge.
1403 */
1404 else if (!remoteheads->next && !common->next && option_commit) {
1405 /*
a75d7b54 1406 * We are not doing octopus, not fast-forward, and have
1c7b76be
MV
1407 * only one common.
1408 */
1409 refresh_cache(REFRESH_QUIET);
a54841e9 1410 if (allow_trivial && fast_forward != FF_ONLY) {
1c7b76be 1411 /* See if it is really trivial. */
f9bc573f 1412 git_committer_info(IDENT_STRICT);
bacec478 1413 printf(_("Trying really trivial in-index merge...\n"));
52684310 1414 if (!read_tree_trivial(&common->item->object.oid,
1415 &head_commit->object.oid,
1416 &remoteheads->item->object.oid)) {
4c57bd27 1417 ret = merge_trivial(head_commit, remoteheads);
d5a35c11
NTND
1418 goto done;
1419 }
bacec478 1420 printf(_("Nope.\n"));
1c7b76be
MV
1421 }
1422 } else {
1423 /*
1424 * An octopus. If we can reach all the remote we are up
1425 * to date.
1426 */
1427 int up_to_date = 1;
1428 struct commit_list *j;
1429
1430 for (j = remoteheads; j; j = j->next) {
1431 struct commit_list *common_one;
1432
1433 /*
1434 * Here we *have* to calculate the individual
1435 * merge_bases again, otherwise "git merge HEAD^
1436 * HEAD^^" would be missed.
1437 */
2ce406cc 1438 common_one = get_merge_bases(head_commit, j->item);
c368dde9 1439 if (oidcmp(&common_one->item->object.oid, &j->item->object.oid)) {
1c7b76be
MV
1440 up_to_date = 0;
1441 break;
1442 }
1443 }
1444 if (up_to_date) {
bef4830e 1445 finish_up_to_date(_("Already up-to-date. Yeeah!"));
d5a35c11 1446 goto done;
1c7b76be
MV
1447 }
1448 }
1449
a54841e9 1450 if (fast_forward == FF_ONLY)
bacec478 1451 die(_("Not possible to fast-forward, aborting."));
13474835 1452
1c7b76be 1453 /* We are going to make a new commit. */
f9bc573f 1454 git_committer_info(IDENT_STRICT);
1c7b76be
MV
1455
1456 /*
1457 * At this point, we need a real merge. No matter what strategy
1458 * we use, it would operate on the index, possibly affecting the
1459 * working tree, and when resolved cleanly, have the desired
1460 * tree in the index -- this means that the index must be in
1461 * sync with the head commit. The strategies are responsible
1462 * to ensure this.
1463 */
b4fd9406
NTND
1464 if (use_strategies_nr == 1 ||
1465 /*
1466 * Stash away the local changes so that we can try more than one.
1467 */
52684310 1468 save_state(&stash))
1469 oidclr(&stash);
1c7b76be
MV
1470
1471 for (i = 0; i < use_strategies_nr; i++) {
1472 int ret;
1473 if (i) {
bacec478 1474 printf(_("Rewinding the tree to pristine...\n"));
52684310 1475 restore_state(&head_commit->object.oid, &stash);
1c7b76be
MV
1476 }
1477 if (use_strategies_nr != 1)
bacec478 1478 printf(_("Trying merge strategy %s...\n"),
1c7b76be
MV
1479 use_strategies[i]->name);
1480 /*
1481 * Remember which strategy left the state in the working
1482 * tree.
1483 */
1484 wt_strategy = use_strategies[i]->name;
1485
1486 ret = try_merge_strategy(use_strategies[i]->name,
4c57bd27 1487 common, remoteheads,
b4391657 1488 head_commit);
1c7b76be
MV
1489 if (!option_commit && !ret) {
1490 merge_was_ok = 1;
1491 /*
1492 * This is necessary here just to avoid writing
1493 * the tree, but later we will *not* exit with
1494 * status code 1 because merge_was_ok is set.
1495 */
1496 ret = 1;
1497 }
1498
1499 if (ret) {
1500 /*
1501 * The backend exits with 1 when conflicts are
1502 * left to be resolved, with 2 when it does not
1503 * handle the given merge at all.
1504 */
1505 if (ret == 1) {
1506 int cnt = evaluate_result();
1507
1508 if (best_cnt <= 0 || cnt <= best_cnt) {
1509 best_strategy = use_strategies[i]->name;
1510 best_cnt = cnt;
1511 }
1512 }
1513 if (merge_was_ok)
1514 break;
1515 else
1516 continue;
1517 }
1518
1519 /* Automerge succeeded. */
52684310 1520 write_tree_trivial(&result_tree);
1c7b76be
MV
1521 automerge_was_ok = 1;
1522 break;
1523 }
1524
1525 /*
1526 * If we have a resulting tree, that means the strategy module
1527 * auto resolved the merge cleanly.
1528 */
d5a35c11 1529 if (automerge_was_ok) {
e78cbf8c
JH
1530 ret = finish_automerge(head_commit, head_subsumed,
1531 common, remoteheads,
52684310 1532 &result_tree, wt_strategy);
d5a35c11
NTND
1533 goto done;
1534 }
1c7b76be
MV
1535
1536 /*
1537 * Pick the result from the best strategy and have the user fix
1538 * it up.
1539 */
1540 if (!best_strategy) {
52684310 1541 restore_state(&head_commit->object.oid, &stash);
1c7b76be
MV
1542 if (use_strategies_nr > 1)
1543 fprintf(stderr,
bacec478 1544 _("No merge strategy handled the merge.\n"));
1c7b76be 1545 else
bacec478 1546 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1c7b76be 1547 use_strategies[0]->name);
d5a35c11
NTND
1548 ret = 2;
1549 goto done;
1c7b76be
MV
1550 } else if (best_strategy == wt_strategy)
1551 ; /* We already have its result in the working tree. */
1552 else {
bacec478 1553 printf(_("Rewinding the tree to pristine...\n"));
52684310 1554 restore_state(&head_commit->object.oid, &stash);
bacec478 1555 printf(_("Using the %s to prepare resolving by hand.\n"),
1c7b76be 1556 best_strategy);
4c57bd27 1557 try_merge_strategy(best_strategy, common, remoteheads,
b4391657 1558 head_commit);
1c7b76be
MV
1559 }
1560
1561 if (squash)
4c57bd27 1562 finish(head_commit, remoteheads, NULL, NULL);
66f4b98a 1563 else
4c57bd27 1564 write_merge_state(remoteheads);
1c7b76be 1565
d5a35c11 1566 if (merge_was_ok)
bacec478
ÆAB
1567 fprintf(stderr, _("Automatic merge went well; "
1568 "stopped before committing as requested\n"));
d5a35c11 1569 else
08e3ce5a 1570 ret = suggest_conflicts();
d5a35c11
NTND
1571
1572done:
96ec7b1e 1573 free(branch_to_free);
d5a35c11 1574 return ret;
1c7b76be 1575}