merge: convert checkout_fast_forward to struct object_id
[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"
10#include "parse-options.h"
11#include "builtin.h"
697cc8ef 12#include "lockfile.h"
1c7b76be
MV
13#include "run-command.h"
14#include "diff.h"
15#include "refs.h"
16#include "commit.h"
17#include "diffcore.h"
18#include "revision.h"
19#include "unpack-trees.h"
20#include "cache-tree.h"
21#include "dir.h"
22#include "utf8.h"
23#include "log-tree.h"
24#include "color.h"
fcab40a3 25#include "rerere.h"
87091b49 26#include "help.h"
18668f53 27#include "merge-recursive.h"
cfc5789a 28#include "resolve-undo.h"
93e535a5 29#include "remote.h"
898eacd8 30#include "fmt-merge-msg.h"
ba3c69a9 31#include "gpg-interface.h"
75c961b7 32#include "sequencer.h"
02a8cfa4 33#include "string-list.h"
1c7b76be
MV
34
35#define DEFAULT_TWOHEAD (1<<0)
36#define DEFAULT_OCTOPUS (1<<1)
37#define NO_FAST_FORWARD (1<<2)
38#define NO_TRIVIAL (1<<3)
39
40struct strategy {
41 const char *name;
42 unsigned attr;
43};
44
45static const char * const builtin_merge_usage[] = {
9c9b4f2f 46 N_("git merge [<options>] [<commit>...]"),
962e6295 47 N_("git merge --abort"),
367ff694 48 N_("git merge --continue"),
1c7b76be
MV
49 NULL
50};
51
898eacd8 52static int show_diffstat = 1, shortlog_len = -1, squash;
a54841e9
MV
53static int option_commit = 1;
54static int option_edit = -1;
efed0022 55static int allow_trivial = 1, have_message, verify_signatures;
c1d7036b 56static int overwrite_ignore = 1;
2c47789d 57static struct strbuf merge_msg = STRBUF_INIT;
1c7b76be
MV
58static struct strategy **use_strategies;
59static size_t use_strategies_nr, use_strategies_alloc;
8cc5b290
AP
60static const char **xopts;
61static size_t xopts_nr, xopts_alloc;
1c7b76be 62static const char *branch;
0d8fc3ef 63static char *branch_mergeoptions;
7610fa57 64static int option_renormalize;
7f87aff2 65static int verbosity;
cb6020bb 66static int allow_rerere_auto;
35d2fffd 67static int abort_current_merge;
367ff694 68static int continue_current_merge;
e379fdf3 69static int allow_unrelated_histories;
99bfc669 70static int show_progress = -1;
a01f7f2b 71static int default_to_upstream = 1;
ba3c69a9 72static const char *sign_commit;
1c7b76be
MV
73
74static struct strategy all_strategy[] = {
1c7b76be
MV
75 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
76 { "octopus", DEFAULT_OCTOPUS },
77 { "resolve", 0 },
1c7b76be
MV
78 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
79 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
80};
81
82static const char *pull_twohead, *pull_octopus;
83
a54841e9
MV
84enum ff_type {
85 FF_NO,
86 FF_ALLOW,
87 FF_ONLY
88};
89
90static enum ff_type fast_forward = FF_ALLOW;
91
1c7b76be
MV
92static int option_parse_message(const struct option *opt,
93 const char *arg, int unset)
94{
95 struct strbuf *buf = opt->value;
96
97 if (unset)
98 strbuf_setlen(buf, 0);
74f5b7fb 99 else if (arg) {
ce9d823b 100 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
1c7b76be 101 have_message = 1;
74f5b7fb 102 } else
bacec478 103 return error(_("switch `m' requires a value"));
1c7b76be
MV
104 return 0;
105}
106
107static struct strategy *get_strategy(const char *name)
108{
109 int i;
87091b49
MV
110 struct strategy *ret;
111 static struct cmdnames main_cmds, other_cmds;
e321180e 112 static int loaded;
1c7b76be
MV
113
114 if (!name)
115 return NULL;
116
117 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
118 if (!strcmp(name, all_strategy[i].name))
119 return &all_strategy[i];
1719b5e4 120
e321180e 121 if (!loaded) {
87091b49 122 struct cmdnames not_strategies;
e321180e 123 loaded = 1;
87091b49 124
87091b49 125 memset(&not_strategies, 0, sizeof(struct cmdnames));
e321180e 126 load_command_list("git-merge-", &main_cmds, &other_cmds);
87091b49
MV
127 for (i = 0; i < main_cmds.cnt; i++) {
128 int j, found = 0;
129 struct cmdname *ent = main_cmds.names[i];
130 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
131 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
132 && !all_strategy[j].name[ent->len])
133 found = 1;
134 if (!found)
135 add_cmdname(&not_strategies, ent->name, ent->len);
87091b49 136 }
ed874656 137 exclude_cmds(&main_cmds, &not_strategies);
87091b49
MV
138 }
139 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
bacec478
ÆAB
140 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
141 fprintf(stderr, _("Available strategies are:"));
131f9a10
JH
142 for (i = 0; i < main_cmds.cnt; i++)
143 fprintf(stderr, " %s", main_cmds.names[i]->name);
144 fprintf(stderr, ".\n");
145 if (other_cmds.cnt) {
bacec478 146 fprintf(stderr, _("Available custom strategies are:"));
131f9a10
JH
147 for (i = 0; i < other_cmds.cnt; i++)
148 fprintf(stderr, " %s", other_cmds.names[i]->name);
149 fprintf(stderr, ".\n");
150 }
87091b49
MV
151 exit(1);
152 }
153
19d4b416 154 ret = xcalloc(1, sizeof(struct strategy));
87091b49 155 ret->name = xstrdup(name);
52b48ef1 156 ret->attr = NO_TRIVIAL;
87091b49 157 return ret;
1c7b76be
MV
158}
159
160static void append_strategy(struct strategy *s)
161{
162 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
163 use_strategies[use_strategies_nr++] = s;
164}
165
166static int option_parse_strategy(const struct option *opt,
167 const char *name, int unset)
168{
1c7b76be
MV
169 if (unset)
170 return 0;
171
1719b5e4 172 append_strategy(get_strategy(name));
1c7b76be
MV
173 return 0;
174}
175
8cc5b290
AP
176static int option_parse_x(const struct option *opt,
177 const char *arg, int unset)
178{
179 if (unset)
180 return 0;
181
182 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
183 xopts[xopts_nr++] = xstrdup(arg);
184 return 0;
185}
186
1c7b76be
MV
187static int option_parse_n(const struct option *opt,
188 const char *arg, int unset)
189{
190 show_diffstat = unset;
191 return 0;
192}
193
194static struct option builtin_merge_options[] = {
195 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
962e6295 196 N_("do not show a diffstat at the end of the merge"),
1c7b76be 197 PARSE_OPT_NOARG, option_parse_n },
d5d09d47 198 OPT_BOOL(0, "stat", &show_diffstat,
962e6295 199 N_("show a diffstat at the end of the merge")),
d5d09d47 200 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
962e6295
NTND
201 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
202 N_("add (at most <n>) entries from shortlog to merge commit message"),
96e9420c 203 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
d5d09d47 204 OPT_BOOL(0, "squash", &squash,
962e6295 205 N_("create a single commit instead of doing a merge")),
d5d09d47 206 OPT_BOOL(0, "commit", &option_commit,
962e6295 207 N_("perform a commit if the merge succeeds (default)")),
f8246281 208 OPT_BOOL('e', "edit", &option_edit,
962e6295 209 N_("edit message before committing")),
a54841e9 210 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
90f867b9 211 { OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
a54841e9 212 N_("abort if fast-forward is not possible"),
90f867b9 213 PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
cb6020bb 214 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
efed0022 215 OPT_BOOL(0, "verify-signatures", &verify_signatures,
c8bb9d2e 216 N_("verify that the named commit has a valid GPG signature")),
962e6295
NTND
217 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
218 N_("merge strategy to use"), option_parse_strategy),
219 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
220 N_("option for selected merge strategy"), option_parse_x),
221 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
222 N_("merge commit message (for a non-fast-forward merge)"),
1c7b76be 223 option_parse_message),
7f87aff2 224 OPT__VERBOSITY(&verbosity),
d5d09d47 225 OPT_BOOL(0, "abort", &abort_current_merge,
962e6295 226 N_("abort the current in-progress merge")),
367ff694
CP
227 OPT_BOOL(0, "continue", &continue_current_merge,
228 N_("continue the current in-progress merge")),
e379fdf3
JH
229 OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
230 N_("allow merging unrelated histories")),
962e6295 231 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
e703d711 232 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
962e6295 233 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
d5d09d47 234 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
1c7b76be
MV
235 OPT_END()
236};
237
238/* Cleans up metadata that is uninteresting after a succeeded merge. */
239static void drop_save(void)
240{
f932729c
JK
241 unlink(git_path_merge_head());
242 unlink(git_path_merge_msg());
243 unlink(git_path_merge_mode());
1c7b76be
MV
244}
245
52684310 246static int save_state(struct object_id *stash)
1c7b76be
MV
247{
248 int len;
d3180279 249 struct child_process cp = CHILD_PROCESS_INIT;
1c7b76be
MV
250 struct strbuf buffer = STRBUF_INIT;
251 const char *argv[] = {"stash", "create", NULL};
252
1c7b76be
MV
253 cp.argv = argv;
254 cp.out = -1;
255 cp.git_cmd = 1;
256
257 if (start_command(&cp))
bacec478 258 die(_("could not run stash."));
1c7b76be
MV
259 len = strbuf_read(&buffer, cp.out, 1024);
260 close(cp.out);
261
262 if (finish_command(&cp) || len < 0)
bacec478 263 die(_("stash failed"));
b4fd9406
NTND
264 else if (!len) /* no changes */
265 return -1;
1c7b76be 266 strbuf_setlen(&buffer, buffer.len-1);
52684310 267 if (get_oid(buffer.buf, stash))
bacec478 268 die(_("not a valid object: %s"), buffer.buf);
b4fd9406 269 return 0;
1c7b76be
MV
270}
271
172b6428
CB
272static void read_empty(unsigned const char *sha1, int verbose)
273{
274 int i = 0;
275 const char *args[7];
276
277 args[i++] = "read-tree";
278 if (verbose)
279 args[i++] = "-v";
280 args[i++] = "-m";
281 args[i++] = "-u";
282 args[i++] = EMPTY_TREE_SHA1_HEX;
283 args[i++] = sha1_to_hex(sha1);
284 args[i] = NULL;
285
286 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 287 die(_("read-tree failed"));
172b6428
CB
288}
289
1c7b76be
MV
290static void reset_hard(unsigned const char *sha1, int verbose)
291{
292 int i = 0;
293 const char *args[6];
294
295 args[i++] = "read-tree";
296 if (verbose)
297 args[i++] = "-v";
298 args[i++] = "--reset";
299 args[i++] = "-u";
300 args[i++] = sha1_to_hex(sha1);
301 args[i] = NULL;
302
303 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 304 die(_("read-tree failed"));
1c7b76be
MV
305}
306
52684310 307static void restore_state(const struct object_id *head,
308 const struct object_id *stash)
1c7b76be 309{
f285a2d7 310 struct strbuf sb = STRBUF_INIT;
1c7b76be
MV
311 const char *args[] = { "stash", "apply", NULL, NULL };
312
52684310 313 if (is_null_oid(stash))
1c7b76be
MV
314 return;
315
52684310 316 reset_hard(head->hash, 1);
1c7b76be 317
52684310 318 args[2] = oid_to_hex(stash);
1c7b76be
MV
319
320 /*
321 * It is OK to ignore error here, for example when there was
322 * nothing to restore.
323 */
324 run_command_v_opt(args, RUN_GIT_CMD);
325
326 strbuf_release(&sb);
327 refresh_cache(REFRESH_QUIET);
328}
329
330/* This is called when no merge was necessary. */
331static void finish_up_to_date(const char *msg)
332{
7f87aff2 333 if (verbosity >= 0)
bacec478 334 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
1c7b76be
MV
335 drop_save();
336}
337
4c57bd27 338static void squash_message(struct commit *commit, struct commit_list *remoteheads)
1c7b76be
MV
339{
340 struct rev_info rev;
f285a2d7 341 struct strbuf out = STRBUF_INIT;
1c7b76be 342 struct commit_list *j;
dd2e794a 343 struct pretty_print_context ctx = {0};
1c7b76be 344
bacec478 345 printf(_("Squash commit -- not updating HEAD\n"));
1c7b76be
MV
346
347 init_revisions(&rev, NULL);
348 rev.ignore_merges = 1;
349 rev.commit_format = CMIT_FMT_MEDIUM;
350
1c7b76be
MV
351 commit->object.flags |= UNINTERESTING;
352 add_pending_object(&rev, &commit->object, NULL);
353
354 for (j = remoteheads; j; j = j->next)
355 add_pending_object(&rev, &j->item->object, NULL);
356
357 setup_revisions(0, NULL, &rev, NULL);
358 if (prepare_revision_walk(&rev))
bacec478 359 die(_("revision walk setup failed"));
1c7b76be 360
dd2e794a
TR
361 ctx.abbrev = rev.abbrev;
362 ctx.date_mode = rev.date_mode;
6bf13944 363 ctx.fmt = rev.commit_format;
dd2e794a 364
1c7b76be
MV
365 strbuf_addstr(&out, "Squashed commit of the following:\n");
366 while ((commit = get_revision(&rev)) != NULL) {
367 strbuf_addch(&out, '\n');
368 strbuf_addf(&out, "commit %s\n",
f2fd0760 369 oid_to_hex(&commit->object.oid));
6bf13944 370 pretty_print_commit(&ctx, commit, &out);
1c7b76be 371 }
e78d5d49 372 write_file_buf(git_path_squash_msg(), out.buf, out.len);
1c7b76be
MV
373 strbuf_release(&out);
374}
375
894642f6 376static void finish(struct commit *head_commit,
4c57bd27 377 struct commit_list *remoteheads,
52684310 378 const struct object_id *new_head, const char *msg)
1c7b76be 379{
f285a2d7 380 struct strbuf reflog_message = STRBUF_INIT;
52684310 381 const struct object_id *head = &head_commit->object.oid;
1c7b76be 382
1c7b76be
MV
383 if (!msg)
384 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
385 else {
7f87aff2
TA
386 if (verbosity >= 0)
387 printf("%s\n", msg);
1c7b76be
MV
388 strbuf_addf(&reflog_message, "%s: %s",
389 getenv("GIT_REFLOG_ACTION"), msg);
390 }
391 if (squash) {
4c57bd27 392 squash_message(head_commit, remoteheads);
1c7b76be 393 } else {
7f87aff2 394 if (verbosity >= 0 && !merge_msg.len)
bacec478 395 printf(_("No merge message -- not updating HEAD\n"));
1c7b76be
MV
396 else {
397 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
398 update_ref(reflog_message.buf, "HEAD",
52684310 399 new_head->hash, head->hash, 0,
f4124112 400 UPDATE_REFS_DIE_ON_ERR);
1c7b76be
MV
401 /*
402 * We ignore errors in 'gc --auto', since the
403 * user should see them.
404 */
dcacb1b2 405 close_all_packs();
1c7b76be
MV
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);
7a7159ac 412 opts.stat_width = -1; /* use full terminal width */
df44483a 413 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1c7b76be
MV
414 opts.output_format |=
415 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
416 opts.detect_rename = DIFF_DETECT_RENAME;
28452655 417 diff_setup_done(&opts);
52684310 418 diff_tree_sha1(head->hash, new_head->hash, "", &opts);
1c7b76be
MV
419 diffcore_std(&opts);
420 diff_flush(&opts);
421 }
422
423 /* Run a post-merge hook */
15048f8a 424 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
1c7b76be
MV
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{
ae8e4c9c 432 struct commit *remote_head;
52684310 433 struct object_id branch_head;
f285a2d7 434 struct strbuf buf = STRBUF_INIT;
c9717ee9 435 struct strbuf bname = STRBUF_INIT;
1c7b76be 436 const char *ptr;
751c5974 437 char *found_ref;
1c7b76be
MV
438 int len, early;
439
0e9f62da 440 strbuf_branchname(&bname, remote, 0);
a552de75 441 remote = bname.buf;
c9717ee9 442
52684310 443 oidclr(&branch_head);
ae8e4c9c 444 remote_head = get_merge_parent(remote);
1c7b76be 445 if (!remote_head)
bacec478 446 die(_("'%s' does not point to a commit"), remote);
1c7b76be 447
52684310 448 if (dwim_ref(remote, strlen(remote), branch_head.hash, &found_ref) > 0) {
59556548 449 if (starts_with(found_ref, "refs/heads/")) {
751c5974 450 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
52684310 451 oid_to_hex(&branch_head), remote);
751c5974
JK
452 goto cleanup;
453 }
59556548 454 if (starts_with(found_ref, "refs/tags/")) {
57b58db7 455 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
52684310 456 oid_to_hex(&branch_head), remote);
57b58db7
JH
457 goto cleanup;
458 }
59556548 459 if (starts_with(found_ref, "refs/remotes/")) {
13931236 460 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
52684310 461 oid_to_hex(&branch_head), remote);
69a8b7c7
JK
462 goto cleanup;
463 }
1c7b76be
MV
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;
1016658d 494 strbuf_addf(&truname, "refs/heads/%s", remote);
9b6bf4d5 495 strbuf_setlen(&truname, truname.len - len);
c6893323 496 if (ref_exists(truname.buf)) {
1c7b76be
MV
497 strbuf_addf(msg,
498 "%s\t\tbranch '%s'%s of .\n",
c368dde9 499 oid_to_hex(&remote_head->object.oid),
9b6bf4d5 500 truname.buf + 11,
1c7b76be 501 (early ? " (early part)" : ""));
c9717ee9
JH
502 strbuf_release(&truname);
503 goto cleanup;
1c7b76be 504 }
1016658d 505 strbuf_release(&truname);
1c7b76be 506 }
2d1495fe
JH
507
508 if (remote_head->util) {
509 struct merge_remote_desc *desc;
510 desc = merge_remote_util(remote_head);
511 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
512 strbuf_addf(msg, "%s\t\t%s '%s'\n",
c368dde9 513 oid_to_hex(&desc->obj->oid),
2d1495fe
JH
514 typename(desc->obj->type),
515 remote);
516 goto cleanup;
517 }
518 }
519
1c7b76be 520 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
c368dde9 521 oid_to_hex(&remote_head->object.oid), remote);
c9717ee9
JH
522cleanup:
523 strbuf_release(&buf);
524 strbuf_release(&bname);
1c7b76be
MV
525}
526
0d8fc3ef
JH
527static void parse_branch_merge_options(char *bmo)
528{
529 const char **argv;
530 int argc;
531
532 if (!bmo)
533 return;
534 argc = split_cmdline(bmo, &argv);
535 if (argc < 0)
c7fe5b61
JH
536 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
537 split_cmdline_strerror(argc));
2756ca43 538 REALLOC_ARRAY(argv, argc + 2);
0d8fc3ef
JH
539 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
540 argc++;
541 argv[0] = "branch.*.mergeoptions";
542 parse_options(argc, argv, NULL, builtin_merge_options,
543 builtin_merge_usage, 0);
544 free(argv);
545}
546
186458b1 547static int git_merge_config(const char *k, const char *v, void *cb)
1c7b76be 548{
898eacd8
JH
549 int status;
550
59556548
CC
551 if (branch && starts_with(k, "branch.") &&
552 starts_with(k + 7, branch) &&
1c7b76be 553 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
0d8fc3ef
JH
554 free(branch_mergeoptions);
555 branch_mergeoptions = xstrdup(v);
556 return 0;
1c7b76be
MV
557 }
558
559 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
560 show_diffstat = git_config_bool(k, v);
561 else if (!strcmp(k, "pull.twohead"))
562 return git_config_string(&pull_twohead, k, v);
563 else if (!strcmp(k, "pull.octopus"))
564 return git_config_string(&pull_octopus, k, v);
7610fa57
JN
565 else if (!strcmp(k, "merge.renormalize"))
566 option_renormalize = git_config_bool(k, v);
898eacd8 567 else if (!strcmp(k, "merge.ff")) {
f23e8dec
JH
568 int boolval = git_config_maybe_bool(k, v);
569 if (0 <= boolval) {
a54841e9 570 fast_forward = boolval ? FF_ALLOW : FF_NO;
f23e8dec 571 } else if (v && !strcmp(v, "only")) {
a54841e9 572 fast_forward = FF_ONLY;
f23e8dec
JH
573 } /* do not barf on values from future versions of git */
574 return 0;
93e535a5
JH
575 } else if (!strcmp(k, "merge.defaulttoupstream")) {
576 default_to_upstream = git_config_bool(k, v);
577 return 0;
d95bfb12
NV
578 } else if (!strcmp(k, "commit.gpgsign")) {
579 sign_commit = git_config_bool(k, v) ? "" : NULL;
580 return 0;
96e9420c 581 }
ba3c69a9 582
898eacd8 583 status = fmt_merge_msg_config(k, v, cb);
5de89d3a
JH
584 if (status)
585 return status;
ba3c69a9 586 status = git_gpg_config(k, v, NULL);
898eacd8
JH
587 if (status)
588 return status;
1c7b76be
MV
589 return git_diff_ui_config(k, v, cb);
590}
591
52684310 592static int read_tree_trivial(struct object_id *common, struct object_id *head,
593 struct object_id *one)
1c7b76be
MV
594{
595 int i, nr_trees = 0;
596 struct tree *trees[MAX_UNPACK_TREES];
597 struct tree_desc t[MAX_UNPACK_TREES];
598 struct unpack_trees_options opts;
599
600 memset(&opts, 0, sizeof(opts));
601 opts.head_idx = 2;
602 opts.src_index = &the_index;
603 opts.dst_index = &the_index;
604 opts.update = 1;
605 opts.verbose_update = 1;
606 opts.trivial_merges_only = 1;
607 opts.merge = 1;
52684310 608 trees[nr_trees] = parse_tree_indirect(common->hash);
1c7b76be
MV
609 if (!trees[nr_trees++])
610 return -1;
52684310 611 trees[nr_trees] = parse_tree_indirect(head->hash);
1c7b76be
MV
612 if (!trees[nr_trees++])
613 return -1;
52684310 614 trees[nr_trees] = parse_tree_indirect(one->hash);
1c7b76be
MV
615 if (!trees[nr_trees++])
616 return -1;
617 opts.fn = threeway_merge;
618 cache_tree_free(&active_cache_tree);
619 for (i = 0; i < nr_trees; i++) {
620 parse_tree(trees[i]);
621 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
622 }
623 if (unpack_trees(nr_trees, t, &opts))
624 return -1;
625 return 0;
626}
627
52684310 628static void write_tree_trivial(struct object_id *oid)
1c7b76be 629{
52684310 630 if (write_cache_as_tree(oid->hash, 0, NULL))
bacec478 631 die(_("git write-tree failed to write a tree"));
1c7b76be
MV
632}
633
3f9083cd 634static int try_merge_strategy(const char *strategy, struct commit_list *common,
4c57bd27 635 struct commit_list *remoteheads,
b4391657 636 struct commit *head)
3f9083cd 637{
daccee38 638 static struct lock_file lock;
b4391657 639 const char *head_arg = "HEAD";
668f26ff 640
b3e83cc7 641 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
668f26ff
MV
642 refresh_cache(REFRESH_QUIET);
643 if (active_cache_changed &&
daccee38 644 write_locked_index(&the_index, &lock, COMMIT_LOCK))
bacec478 645 return error(_("Unable to write index."));
daccee38 646 rollback_lock_file(&lock);
1c7b76be 647
18668f53 648 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
3f9083cd 649 int clean, x;
18668f53 650 struct commit *result;
18668f53
MV
651 struct commit_list *reversed = NULL;
652 struct merge_options o;
3f9083cd 653 struct commit_list *j;
18668f53
MV
654
655 if (remoteheads->next) {
bacec478 656 error(_("Not handling anything other than two heads merge."));
18668f53
MV
657 return 2;
658 }
659
660 init_merge_options(&o);
661 if (!strcmp(strategy, "subtree"))
85e51b78 662 o.subtree_shift = "";
8cc5b290 663
7610fa57 664 o.renormalize = option_renormalize;
99bfc669
JK
665 o.show_rename_progress =
666 show_progress == -1 ? isatty(2) : show_progress;
7610fa57 667
635a7bb1
JN
668 for (x = 0; x < xopts_nr; x++)
669 if (parse_merge_opt(&o, xopts[x]))
bacec478 670 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
18668f53
MV
671
672 o.branch1 = head_arg;
ae8e4c9c 673 o.branch2 = merge_remote_util(remoteheads->item)->name;
18668f53
MV
674
675 for (j = common; j; j = j->next)
676 commit_list_insert(j->item, &reversed);
677
b3e83cc7 678 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
894642f6 679 clean = merge_recursive(&o, head,
18668f53 680 remoteheads->item, reversed, &result);
f241ff0d
JS
681 if (clean < 0)
682 exit(128);
18668f53 683 if (active_cache_changed &&
daccee38 684 write_locked_index(&the_index, &lock, COMMIT_LOCK))
bacec478 685 die (_("unable to write %s"), get_index_file());
daccee38 686 rollback_lock_file(&lock);
18668f53
MV
687 return clean ? 0 : 1;
688 } else {
67ac1e1d
JN
689 return try_merge_command(strategy, xopts_nr, xopts,
690 common, head_arg, remoteheads);
18668f53 691 }
1c7b76be
MV
692}
693
694static void count_diff_files(struct diff_queue_struct *q,
695 struct diff_options *opt, void *data)
696{
697 int *count = data;
698
699 (*count) += q->nr;
700}
701
702static int count_unmerged_entries(void)
703{
1c7b76be
MV
704 int i, ret = 0;
705
be6ff819
JH
706 for (i = 0; i < active_nr; i++)
707 if (ce_stage(active_cache[i]))
1c7b76be
MV
708 ret++;
709
710 return ret;
711}
712
1c7b76be
MV
713static void add_strategies(const char *string, unsigned attr)
714{
02a8cfa4
RS
715 int i;
716
717 if (string) {
718 struct string_list list = STRING_LIST_INIT_DUP;
719 struct string_list_item *item;
720 string_list_split(&list, string, ' ', -1);
721 for_each_string_list_item(item, &list)
722 append_strategy(get_strategy(item->string));
723 string_list_clear(&list, 0);
1c7b76be
MV
724 return;
725 }
726 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
727 if (all_strategy[i].attr & attr)
728 append_strategy(&all_strategy[i]);
729
730}
731
66f4b98a 732static void read_merge_msg(struct strbuf *msg)
65969d43 733{
f932729c 734 const char *filename = git_path_merge_msg();
66f4b98a 735 strbuf_reset(msg);
418c9b17
JN
736 if (strbuf_read_file(msg, filename, 0) < 0)
737 die_errno(_("Could not read from '%s'"), filename);
65969d43
JS
738}
739
4c57bd27
JH
740static void write_merge_state(struct commit_list *);
741static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
65969d43 742{
66f4b98a
JS
743 if (err_msg)
744 error("%s", err_msg);
745 fprintf(stderr,
746 _("Not committing merge; use 'git commit' to complete the merge.\n"));
4c57bd27 747 write_merge_state(remoteheads);
66f4b98a
JS
748 exit(1);
749}
750
f26af3fc
TR
751static const char merge_editor_comment[] =
752N_("Please enter a commit message to explain why this merge is necessary,\n"
753 "especially if it merges an updated upstream into a topic branch.\n"
754 "\n"
eff80a9f 755 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
f26af3fc
TR
756 "the commit.\n");
757
4c57bd27 758static void prepare_to_commit(struct commit_list *remoteheads)
66f4b98a
JS
759{
760 struct strbuf msg = STRBUF_INIT;
761 strbuf_addbuf(&msg, &merge_msg);
762 strbuf_addch(&msg, '\n');
f26af3fc 763 if (0 < option_edit)
eff80a9f 764 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
e78d5d49 765 write_file_buf(git_path_merge_msg(), msg.buf, msg.len);
0a3beb0e 766 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
f932729c 767 git_path_merge_msg(), "merge", NULL))
3e4141d0 768 abort_commit(remoteheads, NULL);
f8246281 769 if (0 < option_edit) {
f932729c 770 if (launch_editor(git_path_merge_msg(), NULL, NULL))
4c57bd27 771 abort_commit(remoteheads, NULL);
66f4b98a
JS
772 }
773 read_merge_msg(&msg);
63af4a84 774 strbuf_stripspace(&msg, 0 < option_edit);
66f4b98a 775 if (!msg.len)
4c57bd27 776 abort_commit(remoteheads, _("Empty commit message."));
66f4b98a
JS
777 strbuf_release(&merge_msg);
778 strbuf_addbuf(&merge_msg, &msg);
779 strbuf_release(&msg);
65969d43
JS
780}
781
4c57bd27 782static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
1c7b76be 783{
52684310 784 struct object_id result_tree, result_commit;
910a09a7 785 struct commit_list *parents, **pptr = &parents;
40d71940
EN
786 static struct lock_file lock;
787
b3e83cc7 788 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
40d71940
EN
789 refresh_cache(REFRESH_QUIET);
790 if (active_cache_changed &&
791 write_locked_index(&the_index, &lock, COMMIT_LOCK))
792 return error(_("Unable to write index."));
793 rollback_lock_file(&lock);
1c7b76be 794
52684310 795 write_tree_trivial(&result_tree);
157efde1 796 printf(_("Wonderful.\n"));
910a09a7
RS
797 pptr = commit_list_append(head, pptr);
798 pptr = commit_list_append(remoteheads->item, pptr);
4c57bd27 799 prepare_to_commit(remoteheads);
52684310 800 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree.hash, parents,
801 result_commit.hash, NULL, sign_commit))
6b3c4c05 802 die(_("failed to write commit object"));
52684310 803 finish(head, remoteheads, &result_commit, "In-index merge");
1c7b76be
MV
804 drop_save();
805 return 0;
806}
807
894642f6 808static int finish_automerge(struct commit *head,
e78cbf8c 809 int head_subsumed,
894642f6 810 struct commit_list *common,
4c57bd27 811 struct commit_list *remoteheads,
52684310 812 struct object_id *result_tree,
1c7b76be
MV
813 const char *wt_strategy)
814{
e78cbf8c 815 struct commit_list *parents = NULL;
1c7b76be 816 struct strbuf buf = STRBUF_INIT;
52684310 817 struct object_id result_commit;
1c7b76be
MV
818
819 free_commit_list(common);
e78cbf8c 820 parents = remoteheads;
a54841e9 821 if (!head_subsumed || fast_forward == FF_NO)
894642f6 822 commit_list_insert(head, &parents);
1c7b76be 823 strbuf_addch(&merge_msg, '\n');
4c57bd27 824 prepare_to_commit(remoteheads);
52684310 825 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree->hash, parents,
826 result_commit.hash, NULL, sign_commit))
6b3c4c05 827 die(_("failed to write commit object"));
f23101bf 828 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
52684310 829 finish(head, remoteheads, &result_commit, buf.buf);
1c7b76be
MV
830 strbuf_release(&buf);
831 drop_save();
832 return 0;
833}
834
08e3ce5a 835static int suggest_conflicts(void)
1c7b76be 836{
418c9b17 837 const char *filename;
1c7b76be 838 FILE *fp;
75c961b7 839 struct strbuf msgbuf = STRBUF_INIT;
1c7b76be 840
f932729c 841 filename = git_path_merge_msg();
418c9b17 842 fp = fopen(filename, "a");
1c7b76be 843 if (!fp)
418c9b17 844 die_errno(_("Could not open '%s' for writing"), filename);
75c961b7
JH
845
846 append_conflicts_hint(&msgbuf);
847 fputs(msgbuf.buf, fp);
8d025b7c 848 strbuf_release(&msgbuf);
1c7b76be 849 fclose(fp);
cb6020bb 850 rerere(allow_rerere_auto);
bacec478
ÆAB
851 printf(_("Automatic merge failed; "
852 "fix conflicts and then commit the result.\n"));
1c7b76be
MV
853 return 1;
854}
855
1c7b76be
MV
856static int evaluate_result(void)
857{
858 int cnt = 0;
859 struct rev_info rev;
860
1c7b76be
MV
861 /* Check how many files differ. */
862 init_revisions(&rev, "");
863 setup_revisions(0, NULL, &rev, NULL);
864 rev.diffopt.output_format |=
865 DIFF_FORMAT_CALLBACK;
866 rev.diffopt.format_callback = count_diff_files;
867 rev.diffopt.format_callback_data = &cnt;
868 run_diff_files(&rev, 0);
869
870 /*
871 * Check how many unmerged entries are
872 * there.
873 */
874 cnt += count_unmerged_entries();
875
876 return cnt;
877}
878
93e535a5 879/*
d6ac1d21 880 * Pretend as if the user told us to merge with the remote-tracking
93e535a5
JH
881 * branch we have for the upstream of the current branch
882 */
883static int setup_with_upstream(const char ***argv)
884{
885 struct branch *branch = branch_get(NULL);
886 int i;
887 const char **args;
888
889 if (!branch)
c7f426d4 890 die(_("No current branch."));
9e3751d4 891 if (!branch->remote_name)
c7f426d4 892 die(_("No remote for the current branch."));
93e535a5 893 if (!branch->merge_nr)
c7f426d4 894 die(_("No default upstream defined for the current branch."));
93e535a5 895
50a6c8ef 896 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
93e535a5
JH
897 for (i = 0; i < branch->merge_nr; i++) {
898 if (!branch->merge[i]->dst)
d6ac1d21 899 die(_("No remote-tracking branch for %s from %s"),
93e535a5
JH
900 branch->merge[i]->src, branch->remote_name);
901 args[i] = branch->merge[i]->dst;
902 }
903 args[i] = NULL;
904 *argv = args;
905 return i;
906}
907
4c57bd27 908static void write_merge_state(struct commit_list *remoteheads)
66f4b98a 909{
66f4b98a
JS
910 struct commit_list *j;
911 struct strbuf buf = STRBUF_INIT;
912
274a5c06 913 for (j = remoteheads; j; j = j->next) {
f2fd0760 914 struct object_id *oid;
274a5c06
JH
915 struct commit *c = j->item;
916 if (c->util && merge_remote_util(c)->obj) {
f2fd0760 917 oid = &merge_remote_util(c)->obj->oid;
274a5c06 918 } else {
f2fd0760 919 oid = &c->object.oid;
274a5c06 920 }
f2fd0760 921 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
274a5c06 922 }
e78d5d49 923 write_file_buf(git_path_merge_head(), buf.buf, buf.len);
66f4b98a 924 strbuf_addch(&merge_msg, '\n');
e78d5d49 925 write_file_buf(git_path_merge_msg(), merge_msg.buf, merge_msg.len);
418c9b17 926
66f4b98a 927 strbuf_reset(&buf);
a54841e9 928 if (fast_forward == FF_NO)
a22ae753 929 strbuf_addstr(&buf, "no-ff");
e78d5d49 930 write_file_buf(git_path_merge_mode(), buf.buf, buf.len);
66f4b98a
JS
931}
932
f8246281
JH
933static int default_edit_option(void)
934{
935 static const char name[] = "GIT_MERGE_AUTOEDIT";
936 const char *e = getenv(name);
937 struct stat st_stdin, st_stdout;
938
939 if (have_message)
940 /* an explicit -m msg without --[no-]edit */
941 return 0;
942
943 if (e) {
944 int v = git_config_maybe_bool(name, e);
945 if (v < 0)
bef4830e 946 die(_("Bad value '%s' in environment '%s'"), e, name);
f8246281
JH
947 return v;
948 }
949
950 /* Use editor if stdin and stdout are the same and is a tty */
951 return (!fstat(0, &st_stdin) &&
952 !fstat(1, &st_stdout) &&
d46f476c 953 isatty(0) && isatty(1) &&
f8246281
JH
954 st_stdin.st_dev == st_stdout.st_dev &&
955 st_stdin.st_ino == st_stdout.st_ino &&
956 st_stdin.st_mode == st_stdout.st_mode);
957}
958
34349dbf
JH
959static struct commit_list *reduce_parents(struct commit *head_commit,
960 int *head_subsumed,
961 struct commit_list *remoteheads)
b5d887f9 962{
e510ab89 963 struct commit_list *parents, **remotes;
b5d887f9 964
0b10b8a3
JH
965 /*
966 * Is the current HEAD reachable from another commit being
967 * merged? If so we do not want to record it as a parent of
968 * the resulting merge, unless --no-ff is given. We will flip
969 * this variable to 0 when we find HEAD among the independent
970 * tips being merged.
971 */
972 *head_subsumed = 1;
e78cbf8c 973
0b10b8a3 974 /* Find what parents to record by checking independent ones. */
e78cbf8c
JH
975 parents = reduce_heads(remoteheads);
976
e510ab89
RS
977 remoteheads = NULL;
978 remotes = &remoteheads;
979 while (parents) {
980 struct commit *commit = pop_commit(&parents);
e78cbf8c
JH
981 if (commit == head_commit)
982 *head_subsumed = 0;
983 else
984 remotes = &commit_list_insert(commit, remotes)->next;
985 }
b5d887f9
JH
986 return remoteheads;
987}
f8246281 988
52fecab2
JH
989static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
990{
991 struct fmt_merge_msg_opts opts;
992
993 memset(&opts, 0, sizeof(opts));
994 opts.add_title = !have_message;
995 opts.shortlog_len = shortlog_len;
996 opts.credit_people = (0 < option_edit);
997
998 fmt_merge_msg(merge_names, merge_msg, &opts);
999 if (merge_msg->len)
1000 strbuf_setlen(merge_msg, merge_msg->len - 1);
1001}
1002
74e8bc59
JH
1003static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1004{
1005 const char *filename;
1006 int fd, pos, npos;
1007 struct strbuf fetch_head_file = STRBUF_INIT;
1008
1009 if (!merge_names)
1010 merge_names = &fetch_head_file;
1011
f932729c 1012 filename = git_path_fetch_head();
74e8bc59
JH
1013 fd = open(filename, O_RDONLY);
1014 if (fd < 0)
1015 die_errno(_("could not open '%s' for reading"), filename);
1016
1017 if (strbuf_read(merge_names, fd, 0) < 0)
1018 die_errno(_("could not read '%s'"), filename);
1019 if (close(fd) < 0)
1020 die_errno(_("could not close '%s'"), filename);
1021
1022 for (pos = 0; pos < merge_names->len; pos = npos) {
52684310 1023 struct object_id oid;
74e8bc59
JH
1024 char *ptr;
1025 struct commit *commit;
1026
1027 ptr = strchr(merge_names->buf + pos, '\n');
1028 if (ptr)
1029 npos = ptr - merge_names->buf + 1;
1030 else
1031 npos = merge_names->len;
1032
52684310 1033 if (npos - pos < GIT_SHA1_HEXSZ + 2 ||
1034 get_oid_hex(merge_names->buf + pos, &oid))
74e8bc59 1035 commit = NULL; /* bad */
52684310 1036 else if (memcmp(merge_names->buf + pos + GIT_SHA1_HEXSZ, "\t\t", 2))
74e8bc59
JH
1037 continue; /* not-for-merge */
1038 else {
52684310 1039 char saved = merge_names->buf[pos + GIT_SHA1_HEXSZ];
1040 merge_names->buf[pos + GIT_SHA1_HEXSZ] = '\0';
74e8bc59 1041 commit = get_merge_parent(merge_names->buf + pos);
52684310 1042 merge_names->buf[pos + GIT_SHA1_HEXSZ] = saved;
74e8bc59
JH
1043 }
1044 if (!commit) {
1045 if (ptr)
1046 *ptr = '\0';
bef4830e 1047 die(_("not something we can merge in %s: %s"),
74e8bc59
JH
1048 filename, merge_names->buf + pos);
1049 }
1050 remotes = &commit_list_insert(commit, remotes)->next;
1051 }
1052
1053 if (merge_names == &fetch_head_file)
1054 strbuf_release(&fetch_head_file);
1055}
1056
34349dbf
JH
1057static struct commit_list *collect_parents(struct commit *head_commit,
1058 int *head_subsumed,
1cf32f4d
JH
1059 int argc, const char **argv,
1060 struct strbuf *merge_msg)
34349dbf
JH
1061{
1062 int i;
1063 struct commit_list *remoteheads = NULL;
1064 struct commit_list **remotes = &remoteheads;
77038015
JH
1065 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1066
1067 if (merge_msg && (!have_message || shortlog_len))
1068 autogen = &merge_names;
34349dbf
JH
1069
1070 if (head_commit)
1071 remotes = &commit_list_insert(head_commit, remotes)->next;
34349dbf 1072
74e8bc59
JH
1073 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1074 handle_fetch_head(remotes, autogen);
1075 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1076 } else {
1077 for (i = 0; i < argc; i++) {
1078 struct commit *commit = get_merge_parent(argv[i]);
1079 if (!commit)
1080 help_unknown_ref(argv[i], "merge",
bef4830e 1081 _("not something we can merge"));
74e8bc59
JH
1082 remotes = &commit_list_insert(commit, remotes)->next;
1083 }
1084 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1085 if (autogen) {
1086 struct commit_list *p;
1087 for (p = remoteheads; p; p = p->next)
1088 merge_name(merge_remote_util(p->item)->name, autogen);
1089 }
1090 }
1cf32f4d 1091
77038015 1092 if (autogen) {
77038015
JH
1093 prepare_merge_message(autogen, merge_msg);
1094 strbuf_release(autogen);
1cf32f4d
JH
1095 }
1096
1097 return remoteheads;
34349dbf
JH
1098}
1099
1c7b76be
MV
1100int cmd_merge(int argc, const char **argv, const char *prefix)
1101{
52684310 1102 struct object_id result_tree, stash, head_oid;
894642f6 1103 struct commit *head_commit;
f285a2d7 1104 struct strbuf buf = STRBUF_INIT;
17377b62 1105 int i, ret = 0, head_subsumed;
1c7b76be
MV
1106 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1107 struct commit_list *common = NULL;
1108 const char *best_strategy = NULL, *wt_strategy = NULL;
b5d887f9 1109 struct commit_list *remoteheads, *p;
96ec7b1e 1110 void *branch_to_free;
367ff694 1111 int orig_argc = argc;
1c7b76be 1112
da53eec6
NTND
1113 if (argc == 2 && !strcmp(argv[1], "-h"))
1114 usage_with_options(builtin_merge_usage, builtin_merge_options);
1c7b76be
MV
1115
1116 /*
1117 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1118 * current branch.
1119 */
52684310 1120 branch = branch_to_free = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
59556548 1121 if (branch && starts_with(branch, "refs/heads/"))
96ec7b1e 1122 branch += 11;
52684310 1123 if (!branch || is_null_oid(&head_oid))
894642f6 1124 head_commit = NULL;
baf18fc2 1125 else
bc83266a 1126 head_commit = lookup_commit_or_die(&head_oid, "HEAD");
1c7b76be 1127
5404c116 1128 init_diff_ui_defaults();
1c7b76be
MV
1129 git_config(git_merge_config, NULL);
1130
0d8fc3ef
JH
1131 if (branch_mergeoptions)
1132 parse_branch_merge_options(branch_mergeoptions);
37782920 1133 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1c7b76be 1134 builtin_merge_usage, 0);
898eacd8
JH
1135 if (shortlog_len < 0)
1136 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
2a22c1b3 1137
99bfc669
JK
1138 if (verbosity < 0 && show_progress == -1)
1139 show_progress = 0;
1140
35d2fffd
JH
1141 if (abort_current_merge) {
1142 int nargc = 2;
1143 const char *nargv[] = {"reset", "--merge", NULL};
1144
042e290d 1145 if (orig_argc != 2)
c7d227df 1146 usage_msg_opt(_("--abort expects no arguments"),
042e290d
CP
1147 builtin_merge_usage, builtin_merge_options);
1148
f932729c 1149 if (!file_exists(git_path_merge_head()))
bacec478 1150 die(_("There is no merge to abort (MERGE_HEAD missing)."));
35d2fffd
JH
1151
1152 /* Invoke 'git reset --merge' */
d5a35c11
NTND
1153 ret = cmd_reset(nargc, nargv, prefix);
1154 goto done;
35d2fffd
JH
1155 }
1156
367ff694
CP
1157 if (continue_current_merge) {
1158 int nargc = 1;
1159 const char *nargv[] = {"commit", NULL};
1160
1161 if (orig_argc != 2)
c7d227df 1162 usage_msg_opt(_("--continue expects no arguments"),
367ff694
CP
1163 builtin_merge_usage, builtin_merge_options);
1164
1165 if (!file_exists(git_path_merge_head()))
1166 die(_("There is no merge in progress (MERGE_HEAD missing)."));
1167
1168 /* Invoke 'git commit' */
1169 ret = cmd_commit(nargc, nargv, prefix);
1170 goto done;
1171 }
1172
2a22c1b3
JH
1173 if (read_cache_unmerged())
1174 die_resolve_conflict("merge");
1175
f932729c 1176 if (file_exists(git_path_merge_head())) {
2a22c1b3
JH
1177 /*
1178 * There is no unmerged entry, don't advise 'git
1179 * add/rm <file>', just 'git commit'.
1180 */
1181 if (advice_resolve_conflict)
bacec478 1182 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
ad5fe377 1183 "Please, commit your changes before you merge."));
2a22c1b3 1184 else
bacec478 1185 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
2a22c1b3 1186 }
f932729c 1187 if (file_exists(git_path_cherry_pick_head())) {
d7e5c0cb 1188 if (advice_resolve_conflict)
f68f1801 1189 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
ad5fe377 1190 "Please, commit your changes before you merge."));
d7e5c0cb 1191 else
f68f1801 1192 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
2a22c1b3
JH
1193 }
1194 resolve_undo_clear();
1195
7f87aff2
TA
1196 if (verbosity < 0)
1197 show_diffstat = 0;
1c7b76be
MV
1198
1199 if (squash) {
a54841e9 1200 if (fast_forward == FF_NO)
bacec478 1201 die(_("You cannot combine --squash with --no-ff."));
1c7b76be
MV
1202 option_commit = 0;
1203 }
1204
00c7e7e7
JH
1205 if (!argc) {
1206 if (default_to_upstream)
1207 argc = setup_with_upstream(&argv);
1208 else
1209 die(_("No commit specified and merge.defaultToUpstream not set."));
1210 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1211 argv[0] = "@{-1}";
4e8115ff 1212 }
00c7e7e7 1213
1c7b76be
MV
1214 if (!argc)
1215 usage_with_options(builtin_merge_usage,
1216 builtin_merge_options);
1217
1faac1ce 1218 if (!head_commit) {
1c7b76be
MV
1219 /*
1220 * If the merged head is a valid one there is no reason
1221 * to forbid "git merge" into a branch yet to be born.
1222 * We do the same for "git pull".
1223 */
52684310 1224 struct object_id *remote_head_oid;
4be636f4 1225 if (squash)
bacec478 1226 die(_("Squash commit into empty head not supported yet"));
a54841e9 1227 if (fast_forward == FF_NO)
bacec478
ÆAB
1228 die(_("Non-fast-forward commit does not make sense into "
1229 "an empty head"));
1cf32f4d
JH
1230 remoteheads = collect_parents(head_commit, &head_subsumed,
1231 argc, argv, NULL);
b84e65d4 1232 if (!remoteheads)
bacec478 1233 die(_("%s - not something we can merge"), argv[0]);
eaa4e59c
JH
1234 if (remoteheads->next)
1235 die(_("Can merge only exactly one commit into empty head"));
52684310 1236 remote_head_oid = &remoteheads->item->object.oid;
1237 read_empty(remote_head_oid->hash, 0);
1238 update_ref("initial pull", "HEAD", remote_head_oid->hash,
f4124112 1239 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
d5a35c11 1240 goto done;
1faac1ce 1241 }
1c7b76be 1242
1faac1ce 1243 /*
b4391657
JH
1244 * All the rest are the commits being merged; prepare
1245 * the standard merge summary message to be appended
1246 * to the given message.
1faac1ce 1247 */
b4391657
JH
1248 remoteheads = collect_parents(head_commit, &head_subsumed,
1249 argc, argv, &merge_msg);
1c7b76be 1250
894642f6 1251 if (!head_commit || !argc)
1c7b76be
MV
1252 usage_with_options(builtin_merge_usage,
1253 builtin_merge_options);
1254
efed0022
SG
1255 if (verify_signatures) {
1256 for (p = remoteheads; p; p = p->next) {
1257 struct commit *commit = p->item;
dc01505f 1258 char hex[GIT_MAX_HEXSZ + 1];
efed0022
SG
1259 struct signature_check signature_check;
1260 memset(&signature_check, 0, sizeof(signature_check));
1261
1262 check_commit_signature(commit, &signature_check);
1263
ed1c9977 1264 find_unique_abbrev_r(hex, commit->object.oid.hash, DEFAULT_ABBREV);
efed0022
SG
1265 switch (signature_check.result) {
1266 case 'G':
1267 break;
eb307ae7
SG
1268 case 'U':
1269 die(_("Commit %s has an untrusted GPG signature, "
1270 "allegedly by %s."), hex, signature_check.signer);
efed0022
SG
1271 case 'B':
1272 die(_("Commit %s has a bad GPG signature "
1273 "allegedly by %s."), hex, signature_check.signer);
1274 default: /* 'N' */
1275 die(_("Commit %s does not have a GPG signature."), hex);
1276 }
1277 if (verbosity >= 0 && signature_check.result == 'G')
1278 printf(_("Commit %s has a good GPG signature by %s\n"),
1279 hex, signature_check.signer);
1280
01e57b5d 1281 signature_check_clear(&signature_check);
efed0022
SG
1282 }
1283 }
1284
1c7b76be 1285 strbuf_addstr(&buf, "merge");
b5d887f9
JH
1286 for (p = remoteheads; p; p = p->next)
1287 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1c7b76be
MV
1288 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1289 strbuf_reset(&buf);
1290
b5d887f9
JH
1291 for (p = remoteheads; p; p = p->next) {
1292 struct commit *commit = p->item;
ae8e4c9c 1293 strbuf_addf(&buf, "GITHEAD_%s",
c368dde9 1294 oid_to_hex(&commit->object.oid));
b5d887f9 1295 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1c7b76be 1296 strbuf_reset(&buf);
a54841e9 1297 if (fast_forward != FF_ONLY &&
b5c9f1c1 1298 merge_remote_util(commit) &&
fab47d05 1299 merge_remote_util(commit)->obj &&
d82829b6 1300 merge_remote_util(commit)->obj->type == OBJ_TAG)
a54841e9 1301 fast_forward = FF_NO;
1c7b76be
MV
1302 }
1303
f8246281
JH
1304 if (option_edit < 0)
1305 option_edit = default_edit_option();
1306
1c7b76be 1307 if (!use_strategies) {
e78cbf8c
JH
1308 if (!remoteheads)
1309 ; /* already up-to-date */
1310 else if (!remoteheads->next)
1c7b76be
MV
1311 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1312 else
1313 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1314 }
1315
1316 for (i = 0; i < use_strategies_nr; i++) {
1317 if (use_strategies[i]->attr & NO_FAST_FORWARD)
a54841e9 1318 fast_forward = FF_NO;
1c7b76be
MV
1319 if (use_strategies[i]->attr & NO_TRIVIAL)
1320 allow_trivial = 0;
1321 }
1322
e78cbf8c
JH
1323 if (!remoteheads)
1324 ; /* already up-to-date */
1325 else if (!remoteheads->next)
2ce406cc 1326 common = get_merge_bases(head_commit, remoteheads->item);
1c7b76be
MV
1327 else {
1328 struct commit_list *list = remoteheads;
894642f6 1329 commit_list_insert(head_commit, &list);
1c7b76be
MV
1330 common = get_octopus_merge_bases(list);
1331 free(list);
1332 }
1333
ed1c9977 1334 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.oid.hash,
f4124112 1335 NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1c7b76be 1336
e379fdf3
JH
1337 if (remoteheads && !common) {
1338 /* No common ancestors found. */
1339 if (!allow_unrelated_histories)
1340 die(_("refusing to merge unrelated histories"));
1341 /* otherwise, we need a real merge. */
1342 } else if (!remoteheads ||
e78cbf8c
JH
1343 (!remoteheads->next && !common->next &&
1344 common->item == remoteheads->item)) {
1c7b76be
MV
1345 /*
1346 * If head can reach all the merge then we are up to date.
1347 * but first the most common case of merging one remote.
1348 */
bef4830e 1349 finish_up_to_date(_("Already up-to-date."));
d5a35c11 1350 goto done;
a54841e9 1351 } else if (fast_forward != FF_NO && !remoteheads->next &&
1c7b76be 1352 !common->next &&
c368dde9 1353 !oidcmp(&common->item->object.oid, &head_commit->object.oid)) {
1c7b76be 1354 /* Again the most common case of merging one remote. */
f285a2d7 1355 struct strbuf msg = STRBUF_INIT;
ae8e4c9c 1356 struct commit *commit;
1c7b76be 1357
d59f765a 1358 if (verbosity >= 0) {
ef2ed501
JK
1359 printf(_("Updating %s..%s\n"),
1360 find_unique_abbrev(head_commit->object.oid.hash,
1361 DEFAULT_ABBREV),
1362 find_unique_abbrev(remoteheads->item->object.oid.hash,
1363 DEFAULT_ABBREV));
d59f765a 1364 }
a75d7b54 1365 strbuf_addstr(&msg, "Fast-forward");
1c7b76be
MV
1366 if (have_message)
1367 strbuf_addstr(&msg,
1368 " (no commit created; -m option ignored)");
ae8e4c9c 1369 commit = remoteheads->item;
b7f7c079 1370 if (!commit) {
d5a35c11
NTND
1371 ret = 1;
1372 goto done;
1373 }
1c7b76be 1374
f06e90da 1375 if (checkout_fast_forward(&head_commit->object.oid,
1376 &commit->object.oid,
db699a8a 1377 overwrite_ignore)) {
d5a35c11
NTND
1378 ret = 1;
1379 goto done;
1380 }
1c7b76be 1381
52684310 1382 finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
1c7b76be 1383 drop_save();
d5a35c11 1384 goto done;
1c7b76be
MV
1385 } else if (!remoteheads->next && common->next)
1386 ;
1387 /*
a75d7b54 1388 * We are not doing octopus and not fast-forward. Need
1c7b76be
MV
1389 * a real merge.
1390 */
1391 else if (!remoteheads->next && !common->next && option_commit) {
1392 /*
a75d7b54 1393 * We are not doing octopus, not fast-forward, and have
1c7b76be
MV
1394 * only one common.
1395 */
1396 refresh_cache(REFRESH_QUIET);
a54841e9 1397 if (allow_trivial && fast_forward != FF_ONLY) {
1c7b76be 1398 /* See if it is really trivial. */
f9bc573f 1399 git_committer_info(IDENT_STRICT);
bacec478 1400 printf(_("Trying really trivial in-index merge...\n"));
52684310 1401 if (!read_tree_trivial(&common->item->object.oid,
1402 &head_commit->object.oid,
1403 &remoteheads->item->object.oid)) {
4c57bd27 1404 ret = merge_trivial(head_commit, remoteheads);
d5a35c11
NTND
1405 goto done;
1406 }
bacec478 1407 printf(_("Nope.\n"));
1c7b76be
MV
1408 }
1409 } else {
1410 /*
1411 * An octopus. If we can reach all the remote we are up
1412 * to date.
1413 */
1414 int up_to_date = 1;
1415 struct commit_list *j;
1416
1417 for (j = remoteheads; j; j = j->next) {
1418 struct commit_list *common_one;
1419
1420 /*
1421 * Here we *have* to calculate the individual
1422 * merge_bases again, otherwise "git merge HEAD^
1423 * HEAD^^" would be missed.
1424 */
2ce406cc 1425 common_one = get_merge_bases(head_commit, j->item);
c368dde9 1426 if (oidcmp(&common_one->item->object.oid, &j->item->object.oid)) {
1c7b76be
MV
1427 up_to_date = 0;
1428 break;
1429 }
1430 }
1431 if (up_to_date) {
bef4830e 1432 finish_up_to_date(_("Already up-to-date. Yeeah!"));
d5a35c11 1433 goto done;
1c7b76be
MV
1434 }
1435 }
1436
a54841e9 1437 if (fast_forward == FF_ONLY)
bacec478 1438 die(_("Not possible to fast-forward, aborting."));
13474835 1439
1c7b76be 1440 /* We are going to make a new commit. */
f9bc573f 1441 git_committer_info(IDENT_STRICT);
1c7b76be
MV
1442
1443 /*
1444 * At this point, we need a real merge. No matter what strategy
1445 * we use, it would operate on the index, possibly affecting the
1446 * working tree, and when resolved cleanly, have the desired
1447 * tree in the index -- this means that the index must be in
1448 * sync with the head commit. The strategies are responsible
1449 * to ensure this.
1450 */
b4fd9406
NTND
1451 if (use_strategies_nr == 1 ||
1452 /*
1453 * Stash away the local changes so that we can try more than one.
1454 */
52684310 1455 save_state(&stash))
1456 oidclr(&stash);
1c7b76be
MV
1457
1458 for (i = 0; i < use_strategies_nr; i++) {
1459 int ret;
1460 if (i) {
bacec478 1461 printf(_("Rewinding the tree to pristine...\n"));
52684310 1462 restore_state(&head_commit->object.oid, &stash);
1c7b76be
MV
1463 }
1464 if (use_strategies_nr != 1)
bacec478 1465 printf(_("Trying merge strategy %s...\n"),
1c7b76be
MV
1466 use_strategies[i]->name);
1467 /*
1468 * Remember which strategy left the state in the working
1469 * tree.
1470 */
1471 wt_strategy = use_strategies[i]->name;
1472
1473 ret = try_merge_strategy(use_strategies[i]->name,
4c57bd27 1474 common, remoteheads,
b4391657 1475 head_commit);
1c7b76be
MV
1476 if (!option_commit && !ret) {
1477 merge_was_ok = 1;
1478 /*
1479 * This is necessary here just to avoid writing
1480 * the tree, but later we will *not* exit with
1481 * status code 1 because merge_was_ok is set.
1482 */
1483 ret = 1;
1484 }
1485
1486 if (ret) {
1487 /*
1488 * The backend exits with 1 when conflicts are
1489 * left to be resolved, with 2 when it does not
1490 * handle the given merge at all.
1491 */
1492 if (ret == 1) {
1493 int cnt = evaluate_result();
1494
1495 if (best_cnt <= 0 || cnt <= best_cnt) {
1496 best_strategy = use_strategies[i]->name;
1497 best_cnt = cnt;
1498 }
1499 }
1500 if (merge_was_ok)
1501 break;
1502 else
1503 continue;
1504 }
1505
1506 /* Automerge succeeded. */
52684310 1507 write_tree_trivial(&result_tree);
1c7b76be
MV
1508 automerge_was_ok = 1;
1509 break;
1510 }
1511
1512 /*
1513 * If we have a resulting tree, that means the strategy module
1514 * auto resolved the merge cleanly.
1515 */
d5a35c11 1516 if (automerge_was_ok) {
e78cbf8c
JH
1517 ret = finish_automerge(head_commit, head_subsumed,
1518 common, remoteheads,
52684310 1519 &result_tree, wt_strategy);
d5a35c11
NTND
1520 goto done;
1521 }
1c7b76be
MV
1522
1523 /*
1524 * Pick the result from the best strategy and have the user fix
1525 * it up.
1526 */
1527 if (!best_strategy) {
52684310 1528 restore_state(&head_commit->object.oid, &stash);
1c7b76be
MV
1529 if (use_strategies_nr > 1)
1530 fprintf(stderr,
bacec478 1531 _("No merge strategy handled the merge.\n"));
1c7b76be 1532 else
bacec478 1533 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1c7b76be 1534 use_strategies[0]->name);
d5a35c11
NTND
1535 ret = 2;
1536 goto done;
1c7b76be
MV
1537 } else if (best_strategy == wt_strategy)
1538 ; /* We already have its result in the working tree. */
1539 else {
bacec478 1540 printf(_("Rewinding the tree to pristine...\n"));
52684310 1541 restore_state(&head_commit->object.oid, &stash);
bacec478 1542 printf(_("Using the %s to prepare resolving by hand.\n"),
1c7b76be 1543 best_strategy);
4c57bd27 1544 try_merge_strategy(best_strategy, common, remoteheads,
b4391657 1545 head_commit);
1c7b76be
MV
1546 }
1547
1548 if (squash)
4c57bd27 1549 finish(head_commit, remoteheads, NULL, NULL);
66f4b98a 1550 else
4c57bd27 1551 write_merge_state(remoteheads);
1c7b76be 1552
d5a35c11 1553 if (merge_was_ok)
bacec478
ÆAB
1554 fprintf(stderr, _("Automatic merge went well; "
1555 "stopped before committing as requested\n"));
d5a35c11 1556 else
08e3ce5a 1557 ret = suggest_conflicts();
d5a35c11
NTND
1558
1559done:
96ec7b1e 1560 free(branch_to_free);
d5a35c11 1561 return ret;
1c7b76be 1562}