refs: convert update_ref and refs_update_ref to use 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"
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;
f8b86359 76static int verify_msg = 1;
1c7b76be
MV
77
78static struct strategy all_strategy[] = {
1c7b76be
MV
79 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
80 { "octopus", DEFAULT_OCTOPUS },
81 { "resolve", 0 },
1c7b76be
MV
82 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
83 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
84};
85
86static const char *pull_twohead, *pull_octopus;
87
a54841e9
MV
88enum ff_type {
89 FF_NO,
90 FF_ALLOW,
91 FF_ONLY
92};
93
94static enum ff_type fast_forward = FF_ALLOW;
95
1c7b76be
MV
96static int option_parse_message(const struct option *opt,
97 const char *arg, int unset)
98{
99 struct strbuf *buf = opt->value;
100
101 if (unset)
102 strbuf_setlen(buf, 0);
74f5b7fb 103 else if (arg) {
ce9d823b 104 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
1c7b76be 105 have_message = 1;
74f5b7fb 106 } else
bacec478 107 return error(_("switch `m' requires a value"));
1c7b76be
MV
108 return 0;
109}
110
111static struct strategy *get_strategy(const char *name)
112{
113 int i;
87091b49
MV
114 struct strategy *ret;
115 static struct cmdnames main_cmds, other_cmds;
e321180e 116 static int loaded;
1c7b76be
MV
117
118 if (!name)
119 return NULL;
120
121 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
122 if (!strcmp(name, all_strategy[i].name))
123 return &all_strategy[i];
1719b5e4 124
e321180e 125 if (!loaded) {
87091b49 126 struct cmdnames not_strategies;
e321180e 127 loaded = 1;
87091b49 128
87091b49 129 memset(&not_strategies, 0, sizeof(struct cmdnames));
e321180e 130 load_command_list("git-merge-", &main_cmds, &other_cmds);
87091b49
MV
131 for (i = 0; i < main_cmds.cnt; i++) {
132 int j, found = 0;
133 struct cmdname *ent = main_cmds.names[i];
134 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
135 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
136 && !all_strategy[j].name[ent->len])
137 found = 1;
138 if (!found)
139 add_cmdname(&not_strategies, ent->name, ent->len);
87091b49 140 }
ed874656 141 exclude_cmds(&main_cmds, &not_strategies);
87091b49
MV
142 }
143 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
bacec478
ÆAB
144 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
145 fprintf(stderr, _("Available strategies are:"));
131f9a10
JH
146 for (i = 0; i < main_cmds.cnt; i++)
147 fprintf(stderr, " %s", main_cmds.names[i]->name);
148 fprintf(stderr, ".\n");
149 if (other_cmds.cnt) {
bacec478 150 fprintf(stderr, _("Available custom strategies are:"));
131f9a10
JH
151 for (i = 0; i < other_cmds.cnt; i++)
152 fprintf(stderr, " %s", other_cmds.names[i]->name);
153 fprintf(stderr, ".\n");
154 }
87091b49
MV
155 exit(1);
156 }
157
19d4b416 158 ret = xcalloc(1, sizeof(struct strategy));
87091b49 159 ret->name = xstrdup(name);
52b48ef1 160 ret->attr = NO_TRIVIAL;
87091b49 161 return ret;
1c7b76be
MV
162}
163
164static void append_strategy(struct strategy *s)
165{
166 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
167 use_strategies[use_strategies_nr++] = s;
168}
169
170static int option_parse_strategy(const struct option *opt,
171 const char *name, int unset)
172{
1c7b76be
MV
173 if (unset)
174 return 0;
175
1719b5e4 176 append_strategy(get_strategy(name));
1c7b76be
MV
177 return 0;
178}
179
8cc5b290
AP
180static int option_parse_x(const struct option *opt,
181 const char *arg, int unset)
182{
183 if (unset)
184 return 0;
185
186 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
187 xopts[xopts_nr++] = xstrdup(arg);
188 return 0;
189}
190
1c7b76be
MV
191static int option_parse_n(const struct option *opt,
192 const char *arg, int unset)
193{
194 show_diffstat = unset;
195 return 0;
196}
197
198static struct option builtin_merge_options[] = {
199 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
962e6295 200 N_("do not show a diffstat at the end of the merge"),
1c7b76be 201 PARSE_OPT_NOARG, option_parse_n },
d5d09d47 202 OPT_BOOL(0, "stat", &show_diffstat,
962e6295 203 N_("show a diffstat at the end of the merge")),
d5d09d47 204 OPT_BOOL(0, "summary", &show_diffstat, N_("(synonym to --stat)")),
962e6295
NTND
205 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
206 N_("add (at most <n>) entries from shortlog to merge commit message"),
96e9420c 207 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
d5d09d47 208 OPT_BOOL(0, "squash", &squash,
962e6295 209 N_("create a single commit instead of doing a merge")),
d5d09d47 210 OPT_BOOL(0, "commit", &option_commit,
962e6295 211 N_("perform a commit if the merge succeeds (default)")),
f8246281 212 OPT_BOOL('e', "edit", &option_edit,
962e6295 213 N_("edit message before committing")),
a54841e9 214 OPT_SET_INT(0, "ff", &fast_forward, N_("allow fast-forward (default)"), FF_ALLOW),
90f867b9 215 { OPTION_SET_INT, 0, "ff-only", &fast_forward, NULL,
a54841e9 216 N_("abort if fast-forward is not possible"),
90f867b9 217 PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, FF_ONLY },
cb6020bb 218 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
efed0022 219 OPT_BOOL(0, "verify-signatures", &verify_signatures,
c8bb9d2e 220 N_("verify that the named commit has a valid GPG signature")),
962e6295
NTND
221 OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
222 N_("merge strategy to use"), option_parse_strategy),
223 OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
224 N_("option for selected merge strategy"), option_parse_x),
225 OPT_CALLBACK('m', "message", &merge_msg, N_("message"),
226 N_("merge commit message (for a non-fast-forward merge)"),
1c7b76be 227 option_parse_message),
7f87aff2 228 OPT__VERBOSITY(&verbosity),
d5d09d47 229 OPT_BOOL(0, "abort", &abort_current_merge,
962e6295 230 N_("abort the current in-progress merge")),
367ff694
CP
231 OPT_BOOL(0, "continue", &continue_current_merge,
232 N_("continue the current in-progress merge")),
e379fdf3
JH
233 OPT_BOOL(0, "allow-unrelated-histories", &allow_unrelated_histories,
234 N_("allow merging unrelated histories")),
962e6295 235 OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
e703d711 236 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
962e6295 237 N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
d5d09d47 238 OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
14d01b4f 239 OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
f8b86359 240 OPT_BOOL(0, "verify", &verify_msg, N_("verify commit-msg hook")),
1c7b76be
MV
241 OPT_END()
242};
243
244/* Cleans up metadata that is uninteresting after a succeeded merge. */
245static void drop_save(void)
246{
f932729c
JK
247 unlink(git_path_merge_head());
248 unlink(git_path_merge_msg());
249 unlink(git_path_merge_mode());
1c7b76be
MV
250}
251
52684310 252static int save_state(struct object_id *stash)
1c7b76be
MV
253{
254 int len;
d3180279 255 struct child_process cp = CHILD_PROCESS_INIT;
1c7b76be
MV
256 struct strbuf buffer = STRBUF_INIT;
257 const char *argv[] = {"stash", "create", NULL};
150888e2 258 int rc = -1;
1c7b76be 259
1c7b76be
MV
260 cp.argv = argv;
261 cp.out = -1;
262 cp.git_cmd = 1;
263
264 if (start_command(&cp))
bacec478 265 die(_("could not run stash."));
1c7b76be
MV
266 len = strbuf_read(&buffer, cp.out, 1024);
267 close(cp.out);
268
269 if (finish_command(&cp) || len < 0)
bacec478 270 die(_("stash failed"));
b4fd9406 271 else if (!len) /* no changes */
150888e2 272 goto out;
1c7b76be 273 strbuf_setlen(&buffer, buffer.len-1);
52684310 274 if (get_oid(buffer.buf, stash))
bacec478 275 die(_("not a valid object: %s"), buffer.buf);
150888e2
RS
276 rc = 0;
277out:
278 strbuf_release(&buffer);
279 return rc;
1c7b76be
MV
280}
281
172b6428
CB
282static void read_empty(unsigned const char *sha1, int verbose)
283{
284 int i = 0;
285 const char *args[7];
286
287 args[i++] = "read-tree";
288 if (verbose)
289 args[i++] = "-v";
290 args[i++] = "-m";
291 args[i++] = "-u";
292 args[i++] = EMPTY_TREE_SHA1_HEX;
293 args[i++] = sha1_to_hex(sha1);
294 args[i] = NULL;
295
296 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 297 die(_("read-tree failed"));
172b6428
CB
298}
299
1c7b76be
MV
300static void reset_hard(unsigned const char *sha1, int verbose)
301{
302 int i = 0;
303 const char *args[6];
304
305 args[i++] = "read-tree";
306 if (verbose)
307 args[i++] = "-v";
308 args[i++] = "--reset";
309 args[i++] = "-u";
310 args[i++] = sha1_to_hex(sha1);
311 args[i] = NULL;
312
313 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 314 die(_("read-tree failed"));
1c7b76be
MV
315}
316
52684310 317static void restore_state(const struct object_id *head,
318 const struct object_id *stash)
1c7b76be 319{
f285a2d7 320 struct strbuf sb = STRBUF_INIT;
1c7b76be
MV
321 const char *args[] = { "stash", "apply", NULL, NULL };
322
52684310 323 if (is_null_oid(stash))
1c7b76be
MV
324 return;
325
52684310 326 reset_hard(head->hash, 1);
1c7b76be 327
52684310 328 args[2] = oid_to_hex(stash);
1c7b76be
MV
329
330 /*
331 * It is OK to ignore error here, for example when there was
332 * nothing to restore.
333 */
334 run_command_v_opt(args, RUN_GIT_CMD);
335
336 strbuf_release(&sb);
337 refresh_cache(REFRESH_QUIET);
338}
339
340/* This is called when no merge was necessary. */
341static void finish_up_to_date(const char *msg)
342{
7f87aff2 343 if (verbosity >= 0)
bacec478 344 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
1c7b76be
MV
345 drop_save();
346}
347
4c57bd27 348static void squash_message(struct commit *commit, struct commit_list *remoteheads)
1c7b76be
MV
349{
350 struct rev_info rev;
f285a2d7 351 struct strbuf out = STRBUF_INIT;
1c7b76be 352 struct commit_list *j;
dd2e794a 353 struct pretty_print_context ctx = {0};
1c7b76be 354
bacec478 355 printf(_("Squash commit -- not updating HEAD\n"));
1c7b76be
MV
356
357 init_revisions(&rev, NULL);
358 rev.ignore_merges = 1;
359 rev.commit_format = CMIT_FMT_MEDIUM;
360
1c7b76be
MV
361 commit->object.flags |= UNINTERESTING;
362 add_pending_object(&rev, &commit->object, NULL);
363
364 for (j = remoteheads; j; j = j->next)
365 add_pending_object(&rev, &j->item->object, NULL);
366
367 setup_revisions(0, NULL, &rev, NULL);
368 if (prepare_revision_walk(&rev))
bacec478 369 die(_("revision walk setup failed"));
1c7b76be 370
dd2e794a
TR
371 ctx.abbrev = rev.abbrev;
372 ctx.date_mode = rev.date_mode;
6bf13944 373 ctx.fmt = rev.commit_format;
dd2e794a 374
1c7b76be
MV
375 strbuf_addstr(&out, "Squashed commit of the following:\n");
376 while ((commit = get_revision(&rev)) != NULL) {
377 strbuf_addch(&out, '\n');
378 strbuf_addf(&out, "commit %s\n",
f2fd0760 379 oid_to_hex(&commit->object.oid));
6bf13944 380 pretty_print_commit(&ctx, commit, &out);
1c7b76be 381 }
e78d5d49 382 write_file_buf(git_path_squash_msg(), out.buf, out.len);
1c7b76be
MV
383 strbuf_release(&out);
384}
385
894642f6 386static void finish(struct commit *head_commit,
4c57bd27 387 struct commit_list *remoteheads,
52684310 388 const struct object_id *new_head, const char *msg)
1c7b76be 389{
f285a2d7 390 struct strbuf reflog_message = STRBUF_INIT;
52684310 391 const struct object_id *head = &head_commit->object.oid;
1c7b76be 392
1c7b76be
MV
393 if (!msg)
394 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
395 else {
7f87aff2
TA
396 if (verbosity >= 0)
397 printf("%s\n", msg);
1c7b76be
MV
398 strbuf_addf(&reflog_message, "%s: %s",
399 getenv("GIT_REFLOG_ACTION"), msg);
400 }
401 if (squash) {
4c57bd27 402 squash_message(head_commit, remoteheads);
1c7b76be 403 } else {
7f87aff2 404 if (verbosity >= 0 && !merge_msg.len)
bacec478 405 printf(_("No merge message -- not updating HEAD\n"));
1c7b76be
MV
406 else {
407 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
ae077771 408 update_ref(reflog_message.buf, "HEAD", new_head, head,
409 0, UPDATE_REFS_DIE_ON_ERR);
1c7b76be
MV
410 /*
411 * We ignore errors in 'gc --auto', since the
412 * user should see them.
413 */
dcacb1b2 414 close_all_packs();
1c7b76be
MV
415 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
416 }
417 }
418 if (new_head && show_diffstat) {
419 struct diff_options opts;
420 diff_setup(&opts);
7a7159ac 421 opts.stat_width = -1; /* use full terminal width */
df44483a 422 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1c7b76be
MV
423 opts.output_format |=
424 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
425 opts.detect_rename = DIFF_DETECT_RENAME;
28452655 426 diff_setup_done(&opts);
66f414f8 427 diff_tree_oid(head, new_head, "", &opts);
1c7b76be
MV
428 diffcore_std(&opts);
429 diff_flush(&opts);
430 }
431
432 /* Run a post-merge hook */
15048f8a 433 run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
1c7b76be
MV
434
435 strbuf_release(&reflog_message);
436}
437
438/* Get the name for the merge commit's message. */
439static void merge_name(const char *remote, struct strbuf *msg)
440{
ae8e4c9c 441 struct commit *remote_head;
52684310 442 struct object_id branch_head;
f285a2d7 443 struct strbuf buf = STRBUF_INIT;
c9717ee9 444 struct strbuf bname = STRBUF_INIT;
1c7b76be 445 const char *ptr;
751c5974 446 char *found_ref;
1c7b76be
MV
447 int len, early;
448
0e9f62da 449 strbuf_branchname(&bname, remote, 0);
a552de75 450 remote = bname.buf;
c9717ee9 451
52684310 452 oidclr(&branch_head);
ae8e4c9c 453 remote_head = get_merge_parent(remote);
1c7b76be 454 if (!remote_head)
bacec478 455 die(_("'%s' does not point to a commit"), remote);
1c7b76be 456
52684310 457 if (dwim_ref(remote, strlen(remote), branch_head.hash, &found_ref) > 0) {
59556548 458 if (starts_with(found_ref, "refs/heads/")) {
751c5974 459 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
52684310 460 oid_to_hex(&branch_head), remote);
751c5974
JK
461 goto cleanup;
462 }
59556548 463 if (starts_with(found_ref, "refs/tags/")) {
57b58db7 464 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
52684310 465 oid_to_hex(&branch_head), remote);
57b58db7
JH
466 goto cleanup;
467 }
59556548 468 if (starts_with(found_ref, "refs/remotes/")) {
13931236 469 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
52684310 470 oid_to_hex(&branch_head), remote);
69a8b7c7
JK
471 goto cleanup;
472 }
1c7b76be
MV
473 }
474
475 /* See if remote matches <name>^^^.. or <name>~<number> */
476 for (len = 0, ptr = remote + strlen(remote);
477 remote < ptr && ptr[-1] == '^';
478 ptr--)
479 len++;
480 if (len)
481 early = 1;
482 else {
483 early = 0;
484 ptr = strrchr(remote, '~');
485 if (ptr) {
486 int seen_nonzero = 0;
487
488 len++; /* count ~ */
489 while (*++ptr && isdigit(*ptr)) {
490 seen_nonzero |= (*ptr != '0');
491 len++;
492 }
493 if (*ptr)
494 len = 0; /* not ...~<number> */
495 else if (seen_nonzero)
496 early = 1;
497 else if (len == 1)
498 early = 1; /* "name~" is "name~1"! */
499 }
500 }
501 if (len) {
502 struct strbuf truname = STRBUF_INIT;
1016658d 503 strbuf_addf(&truname, "refs/heads/%s", remote);
9b6bf4d5 504 strbuf_setlen(&truname, truname.len - len);
c6893323 505 if (ref_exists(truname.buf)) {
1c7b76be
MV
506 strbuf_addf(msg,
507 "%s\t\tbranch '%s'%s of .\n",
c368dde9 508 oid_to_hex(&remote_head->object.oid),
9b6bf4d5 509 truname.buf + 11,
1c7b76be 510 (early ? " (early part)" : ""));
c9717ee9
JH
511 strbuf_release(&truname);
512 goto cleanup;
1c7b76be 513 }
1016658d 514 strbuf_release(&truname);
1c7b76be 515 }
2d1495fe
JH
516
517 if (remote_head->util) {
518 struct merge_remote_desc *desc;
519 desc = merge_remote_util(remote_head);
520 if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
521 strbuf_addf(msg, "%s\t\t%s '%s'\n",
c368dde9 522 oid_to_hex(&desc->obj->oid),
2d1495fe
JH
523 typename(desc->obj->type),
524 remote);
525 goto cleanup;
526 }
527 }
528
1c7b76be 529 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
c368dde9 530 oid_to_hex(&remote_head->object.oid), remote);
c9717ee9
JH
531cleanup:
532 strbuf_release(&buf);
533 strbuf_release(&bname);
1c7b76be
MV
534}
535
0d8fc3ef
JH
536static void parse_branch_merge_options(char *bmo)
537{
538 const char **argv;
539 int argc;
540
541 if (!bmo)
542 return;
543 argc = split_cmdline(bmo, &argv);
544 if (argc < 0)
c7fe5b61
JH
545 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
546 split_cmdline_strerror(argc));
2756ca43 547 REALLOC_ARRAY(argv, argc + 2);
f331ab9d 548 MOVE_ARRAY(argv + 1, argv, argc + 1);
0d8fc3ef
JH
549 argc++;
550 argv[0] = "branch.*.mergeoptions";
551 parse_options(argc, argv, NULL, builtin_merge_options,
552 builtin_merge_usage, 0);
553 free(argv);
554}
555
186458b1 556static int git_merge_config(const char *k, const char *v, void *cb)
1c7b76be 557{
898eacd8
JH
558 int status;
559
59556548
CC
560 if (branch && starts_with(k, "branch.") &&
561 starts_with(k + 7, branch) &&
1c7b76be 562 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
0d8fc3ef
JH
563 free(branch_mergeoptions);
564 branch_mergeoptions = xstrdup(v);
565 return 0;
1c7b76be
MV
566 }
567
568 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
569 show_diffstat = git_config_bool(k, v);
570 else if (!strcmp(k, "pull.twohead"))
571 return git_config_string(&pull_twohead, k, v);
572 else if (!strcmp(k, "pull.octopus"))
573 return git_config_string(&pull_octopus, k, v);
7610fa57
JN
574 else if (!strcmp(k, "merge.renormalize"))
575 option_renormalize = git_config_bool(k, v);
898eacd8 576 else if (!strcmp(k, "merge.ff")) {
89576613 577 int boolval = git_parse_maybe_bool(v);
f23e8dec 578 if (0 <= boolval) {
a54841e9 579 fast_forward = boolval ? FF_ALLOW : FF_NO;
f23e8dec 580 } else if (v && !strcmp(v, "only")) {
a54841e9 581 fast_forward = FF_ONLY;
f23e8dec
JH
582 } /* do not barf on values from future versions of git */
583 return 0;
93e535a5
JH
584 } else if (!strcmp(k, "merge.defaulttoupstream")) {
585 default_to_upstream = git_config_bool(k, v);
586 return 0;
d95bfb12
NV
587 } else if (!strcmp(k, "commit.gpgsign")) {
588 sign_commit = git_config_bool(k, v) ? "" : NULL;
589 return 0;
96e9420c 590 }
ba3c69a9 591
898eacd8 592 status = fmt_merge_msg_config(k, v, cb);
5de89d3a
JH
593 if (status)
594 return status;
ba3c69a9 595 status = git_gpg_config(k, v, NULL);
898eacd8
JH
596 if (status)
597 return status;
1c7b76be
MV
598 return git_diff_ui_config(k, v, cb);
599}
600
52684310 601static int read_tree_trivial(struct object_id *common, struct object_id *head,
602 struct object_id *one)
1c7b76be
MV
603{
604 int i, nr_trees = 0;
605 struct tree *trees[MAX_UNPACK_TREES];
606 struct tree_desc t[MAX_UNPACK_TREES];
607 struct unpack_trees_options opts;
608
609 memset(&opts, 0, sizeof(opts));
610 opts.head_idx = 2;
611 opts.src_index = &the_index;
612 opts.dst_index = &the_index;
613 opts.update = 1;
614 opts.verbose_update = 1;
615 opts.trivial_merges_only = 1;
616 opts.merge = 1;
a9dbc179 617 trees[nr_trees] = parse_tree_indirect(common);
1c7b76be
MV
618 if (!trees[nr_trees++])
619 return -1;
a9dbc179 620 trees[nr_trees] = parse_tree_indirect(head);
1c7b76be
MV
621 if (!trees[nr_trees++])
622 return -1;
a9dbc179 623 trees[nr_trees] = parse_tree_indirect(one);
1c7b76be
MV
624 if (!trees[nr_trees++])
625 return -1;
626 opts.fn = threeway_merge;
627 cache_tree_free(&active_cache_tree);
628 for (i = 0; i < nr_trees; i++) {
629 parse_tree(trees[i]);
630 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
631 }
632 if (unpack_trees(nr_trees, t, &opts))
633 return -1;
634 return 0;
635}
636
52684310 637static void write_tree_trivial(struct object_id *oid)
1c7b76be 638{
52684310 639 if (write_cache_as_tree(oid->hash, 0, NULL))
bacec478 640 die(_("git write-tree failed to write a tree"));
1c7b76be
MV
641}
642
3f9083cd 643static int try_merge_strategy(const char *strategy, struct commit_list *common,
4c57bd27 644 struct commit_list *remoteheads,
b4391657 645 struct commit *head)
3f9083cd 646{
daccee38 647 static struct lock_file lock;
b4391657 648 const char *head_arg = "HEAD";
668f26ff 649
b3e83cc7 650 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
668f26ff
MV
651 refresh_cache(REFRESH_QUIET);
652 if (active_cache_changed &&
daccee38 653 write_locked_index(&the_index, &lock, COMMIT_LOCK))
bacec478 654 return error(_("Unable to write index."));
daccee38 655 rollback_lock_file(&lock);
1c7b76be 656
18668f53 657 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
3f9083cd 658 int clean, x;
18668f53 659 struct commit *result;
18668f53
MV
660 struct commit_list *reversed = NULL;
661 struct merge_options o;
3f9083cd 662 struct commit_list *j;
18668f53
MV
663
664 if (remoteheads->next) {
bacec478 665 error(_("Not handling anything other than two heads merge."));
18668f53
MV
666 return 2;
667 }
668
669 init_merge_options(&o);
670 if (!strcmp(strategy, "subtree"))
85e51b78 671 o.subtree_shift = "";
8cc5b290 672
7610fa57 673 o.renormalize = option_renormalize;
99bfc669
JK
674 o.show_rename_progress =
675 show_progress == -1 ? isatty(2) : show_progress;
7610fa57 676
635a7bb1
JN
677 for (x = 0; x < xopts_nr; x++)
678 if (parse_merge_opt(&o, xopts[x]))
bacec478 679 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
18668f53
MV
680
681 o.branch1 = head_arg;
ae8e4c9c 682 o.branch2 = merge_remote_util(remoteheads->item)->name;
18668f53
MV
683
684 for (j = common; j; j = j->next)
685 commit_list_insert(j->item, &reversed);
686
b3e83cc7 687 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
894642f6 688 clean = merge_recursive(&o, head,
18668f53 689 remoteheads->item, reversed, &result);
f241ff0d
JS
690 if (clean < 0)
691 exit(128);
18668f53 692 if (active_cache_changed &&
daccee38 693 write_locked_index(&the_index, &lock, COMMIT_LOCK))
bacec478 694 die (_("unable to write %s"), get_index_file());
daccee38 695 rollback_lock_file(&lock);
18668f53
MV
696 return clean ? 0 : 1;
697 } else {
67ac1e1d
JN
698 return try_merge_command(strategy, xopts_nr, xopts,
699 common, head_arg, remoteheads);
18668f53 700 }
1c7b76be
MV
701}
702
703static void count_diff_files(struct diff_queue_struct *q,
704 struct diff_options *opt, void *data)
705{
706 int *count = data;
707
708 (*count) += q->nr;
709}
710
711static int count_unmerged_entries(void)
712{
1c7b76be
MV
713 int i, ret = 0;
714
be6ff819
JH
715 for (i = 0; i < active_nr; i++)
716 if (ce_stage(active_cache[i]))
1c7b76be
MV
717 ret++;
718
719 return ret;
720}
721
1c7b76be
MV
722static void add_strategies(const char *string, unsigned attr)
723{
02a8cfa4
RS
724 int i;
725
726 if (string) {
727 struct string_list list = STRING_LIST_INIT_DUP;
728 struct string_list_item *item;
729 string_list_split(&list, string, ' ', -1);
730 for_each_string_list_item(item, &list)
731 append_strategy(get_strategy(item->string));
732 string_list_clear(&list, 0);
1c7b76be
MV
733 return;
734 }
735 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
736 if (all_strategy[i].attr & attr)
737 append_strategy(&all_strategy[i]);
738
739}
740
66f4b98a 741static void read_merge_msg(struct strbuf *msg)
65969d43 742{
f932729c 743 const char *filename = git_path_merge_msg();
66f4b98a 744 strbuf_reset(msg);
418c9b17
JN
745 if (strbuf_read_file(msg, filename, 0) < 0)
746 die_errno(_("Could not read from '%s'"), filename);
65969d43
JS
747}
748
4c57bd27
JH
749static void write_merge_state(struct commit_list *);
750static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
65969d43 751{
66f4b98a
JS
752 if (err_msg)
753 error("%s", err_msg);
754 fprintf(stderr,
755 _("Not committing merge; use 'git commit' to complete the merge.\n"));
4c57bd27 756 write_merge_state(remoteheads);
66f4b98a
JS
757 exit(1);
758}
759
f26af3fc
TR
760static const char merge_editor_comment[] =
761N_("Please enter a commit message to explain why this merge is necessary,\n"
762 "especially if it merges an updated upstream into a topic branch.\n"
763 "\n"
eff80a9f 764 "Lines starting with '%c' will be ignored, and an empty message aborts\n"
f26af3fc
TR
765 "the commit.\n");
766
9d89b355 767static void write_merge_heads(struct commit_list *);
4c57bd27 768static void prepare_to_commit(struct commit_list *remoteheads)
66f4b98a
JS
769{
770 struct strbuf msg = STRBUF_INIT;
771 strbuf_addbuf(&msg, &merge_msg);
772 strbuf_addch(&msg, '\n');
62dc42b9
MG
773 if (squash)
774 BUG("the control must not reach here under --squash");
f26af3fc 775 if (0 < option_edit)
eff80a9f 776 strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char);
14d01b4f
ŁG
777 if (signoff)
778 append_signoff(&msg, ignore_non_trailer(msg.buf, msg.len), 0);
9d89b355 779 write_merge_heads(remoteheads);
e78d5d49 780 write_file_buf(git_path_merge_msg(), msg.buf, msg.len);
0a3beb0e 781 if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg",
f932729c 782 git_path_merge_msg(), "merge", NULL))
3e4141d0 783 abort_commit(remoteheads, NULL);
f8246281 784 if (0 < option_edit) {
f932729c 785 if (launch_editor(git_path_merge_msg(), NULL, NULL))
4c57bd27 786 abort_commit(remoteheads, NULL);
66f4b98a 787 }
f8b86359
SB
788
789 if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
790 "commit-msg",
791 git_path_merge_msg(), NULL))
792 abort_commit(remoteheads, NULL);
793
66f4b98a 794 read_merge_msg(&msg);
63af4a84 795 strbuf_stripspace(&msg, 0 < option_edit);
66f4b98a 796 if (!msg.len)
4c57bd27 797 abort_commit(remoteheads, _("Empty commit message."));
66f4b98a
JS
798 strbuf_release(&merge_msg);
799 strbuf_addbuf(&merge_msg, &msg);
800 strbuf_release(&msg);
65969d43
JS
801}
802
4c57bd27 803static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
1c7b76be 804{
52684310 805 struct object_id result_tree, result_commit;
910a09a7 806 struct commit_list *parents, **pptr = &parents;
40d71940
EN
807 static struct lock_file lock;
808
b3e83cc7 809 hold_locked_index(&lock, LOCK_DIE_ON_ERROR);
40d71940
EN
810 refresh_cache(REFRESH_QUIET);
811 if (active_cache_changed &&
812 write_locked_index(&the_index, &lock, COMMIT_LOCK))
813 return error(_("Unable to write index."));
814 rollback_lock_file(&lock);
1c7b76be 815
52684310 816 write_tree_trivial(&result_tree);
157efde1 817 printf(_("Wonderful.\n"));
910a09a7
RS
818 pptr = commit_list_append(head, pptr);
819 pptr = commit_list_append(remoteheads->item, pptr);
4c57bd27 820 prepare_to_commit(remoteheads);
52684310 821 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree.hash, parents,
822 result_commit.hash, NULL, sign_commit))
6b3c4c05 823 die(_("failed to write commit object"));
52684310 824 finish(head, remoteheads, &result_commit, "In-index merge");
1c7b76be
MV
825 drop_save();
826 return 0;
827}
828
894642f6 829static int finish_automerge(struct commit *head,
e78cbf8c 830 int head_subsumed,
894642f6 831 struct commit_list *common,
4c57bd27 832 struct commit_list *remoteheads,
52684310 833 struct object_id *result_tree,
1c7b76be
MV
834 const char *wt_strategy)
835{
e78cbf8c 836 struct commit_list *parents = NULL;
1c7b76be 837 struct strbuf buf = STRBUF_INIT;
52684310 838 struct object_id result_commit;
1c7b76be
MV
839
840 free_commit_list(common);
e78cbf8c 841 parents = remoteheads;
a54841e9 842 if (!head_subsumed || fast_forward == FF_NO)
894642f6 843 commit_list_insert(head, &parents);
1c7b76be 844 strbuf_addch(&merge_msg, '\n');
4c57bd27 845 prepare_to_commit(remoteheads);
52684310 846 if (commit_tree(merge_msg.buf, merge_msg.len, result_tree->hash, parents,
847 result_commit.hash, NULL, sign_commit))
6b3c4c05 848 die(_("failed to write commit object"));
f23101bf 849 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
52684310 850 finish(head, remoteheads, &result_commit, buf.buf);
1c7b76be
MV
851 strbuf_release(&buf);
852 drop_save();
853 return 0;
854}
855
08e3ce5a 856static int suggest_conflicts(void)
1c7b76be 857{
418c9b17 858 const char *filename;
1c7b76be 859 FILE *fp;
75c961b7 860 struct strbuf msgbuf = STRBUF_INIT;
1c7b76be 861
f932729c 862 filename = git_path_merge_msg();
23a9e071 863 fp = xfopen(filename, "a");
75c961b7
JH
864
865 append_conflicts_hint(&msgbuf);
866 fputs(msgbuf.buf, fp);
8d025b7c 867 strbuf_release(&msgbuf);
1c7b76be 868 fclose(fp);
cb6020bb 869 rerere(allow_rerere_auto);
bacec478
ÆAB
870 printf(_("Automatic merge failed; "
871 "fix conflicts and then commit the result.\n"));
1c7b76be
MV
872 return 1;
873}
874
1c7b76be
MV
875static int evaluate_result(void)
876{
877 int cnt = 0;
878 struct rev_info rev;
879
1c7b76be
MV
880 /* Check how many files differ. */
881 init_revisions(&rev, "");
882 setup_revisions(0, NULL, &rev, NULL);
883 rev.diffopt.output_format |=
884 DIFF_FORMAT_CALLBACK;
885 rev.diffopt.format_callback = count_diff_files;
886 rev.diffopt.format_callback_data = &cnt;
887 run_diff_files(&rev, 0);
888
889 /*
890 * Check how many unmerged entries are
891 * there.
892 */
893 cnt += count_unmerged_entries();
894
895 return cnt;
896}
897
93e535a5 898/*
d6ac1d21 899 * Pretend as if the user told us to merge with the remote-tracking
93e535a5
JH
900 * branch we have for the upstream of the current branch
901 */
902static int setup_with_upstream(const char ***argv)
903{
904 struct branch *branch = branch_get(NULL);
905 int i;
906 const char **args;
907
908 if (!branch)
c7f426d4 909 die(_("No current branch."));
9e3751d4 910 if (!branch->remote_name)
c7f426d4 911 die(_("No remote for the current branch."));
93e535a5 912 if (!branch->merge_nr)
c7f426d4 913 die(_("No default upstream defined for the current branch."));
93e535a5 914
50a6c8ef 915 args = xcalloc(st_add(branch->merge_nr, 1), sizeof(char *));
93e535a5
JH
916 for (i = 0; i < branch->merge_nr; i++) {
917 if (!branch->merge[i]->dst)
d6ac1d21 918 die(_("No remote-tracking branch for %s from %s"),
93e535a5
JH
919 branch->merge[i]->src, branch->remote_name);
920 args[i] = branch->merge[i]->dst;
921 }
922 args[i] = NULL;
923 *argv = args;
924 return i;
925}
926
8e6a6bb3 927static void write_merge_heads(struct commit_list *remoteheads)
66f4b98a 928{
66f4b98a
JS
929 struct commit_list *j;
930 struct strbuf buf = STRBUF_INIT;
931
274a5c06 932 for (j = remoteheads; j; j = j->next) {
f2fd0760 933 struct object_id *oid;
274a5c06
JH
934 struct commit *c = j->item;
935 if (c->util && merge_remote_util(c)->obj) {
f2fd0760 936 oid = &merge_remote_util(c)->obj->oid;
274a5c06 937 } else {
f2fd0760 938 oid = &c->object.oid;
274a5c06 939 }
f2fd0760 940 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
274a5c06 941 }
e78d5d49 942 write_file_buf(git_path_merge_head(), buf.buf, buf.len);
418c9b17 943
66f4b98a 944 strbuf_reset(&buf);
a54841e9 945 if (fast_forward == FF_NO)
a22ae753 946 strbuf_addstr(&buf, "no-ff");
e78d5d49 947 write_file_buf(git_path_merge_mode(), buf.buf, buf.len);
814c4b37 948 strbuf_release(&buf);
66f4b98a
JS
949}
950
8e6a6bb3
MG
951static void write_merge_state(struct commit_list *remoteheads)
952{
953 write_merge_heads(remoteheads);
954 strbuf_addch(&merge_msg, '\n');
955 write_file_buf(git_path_merge_msg(), merge_msg.buf, merge_msg.len);
956}
957
f8246281
JH
958static int default_edit_option(void)
959{
960 static const char name[] = "GIT_MERGE_AUTOEDIT";
961 const char *e = getenv(name);
962 struct stat st_stdin, st_stdout;
963
964 if (have_message)
965 /* an explicit -m msg without --[no-]edit */
966 return 0;
967
968 if (e) {
89576613 969 int v = git_parse_maybe_bool(e);
f8246281 970 if (v < 0)
bef4830e 971 die(_("Bad value '%s' in environment '%s'"), e, name);
f8246281
JH
972 return v;
973 }
974
975 /* Use editor if stdin and stdout are the same and is a tty */
976 return (!fstat(0, &st_stdin) &&
977 !fstat(1, &st_stdout) &&
d46f476c 978 isatty(0) && isatty(1) &&
f8246281
JH
979 st_stdin.st_dev == st_stdout.st_dev &&
980 st_stdin.st_ino == st_stdout.st_ino &&
981 st_stdin.st_mode == st_stdout.st_mode);
982}
983
34349dbf
JH
984static struct commit_list *reduce_parents(struct commit *head_commit,
985 int *head_subsumed,
986 struct commit_list *remoteheads)
b5d887f9 987{
e510ab89 988 struct commit_list *parents, **remotes;
b5d887f9 989
0b10b8a3
JH
990 /*
991 * Is the current HEAD reachable from another commit being
992 * merged? If so we do not want to record it as a parent of
993 * the resulting merge, unless --no-ff is given. We will flip
994 * this variable to 0 when we find HEAD among the independent
995 * tips being merged.
996 */
997 *head_subsumed = 1;
e78cbf8c 998
0b10b8a3 999 /* Find what parents to record by checking independent ones. */
e78cbf8c
JH
1000 parents = reduce_heads(remoteheads);
1001
e510ab89
RS
1002 remoteheads = NULL;
1003 remotes = &remoteheads;
1004 while (parents) {
1005 struct commit *commit = pop_commit(&parents);
e78cbf8c
JH
1006 if (commit == head_commit)
1007 *head_subsumed = 0;
1008 else
1009 remotes = &commit_list_insert(commit, remotes)->next;
1010 }
b5d887f9
JH
1011 return remoteheads;
1012}
f8246281 1013
52fecab2
JH
1014static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *merge_msg)
1015{
1016 struct fmt_merge_msg_opts opts;
1017
1018 memset(&opts, 0, sizeof(opts));
1019 opts.add_title = !have_message;
1020 opts.shortlog_len = shortlog_len;
1021 opts.credit_people = (0 < option_edit);
1022
1023 fmt_merge_msg(merge_names, merge_msg, &opts);
1024 if (merge_msg->len)
1025 strbuf_setlen(merge_msg, merge_msg->len - 1);
1026}
1027
74e8bc59
JH
1028static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
1029{
1030 const char *filename;
1031 int fd, pos, npos;
1032 struct strbuf fetch_head_file = STRBUF_INIT;
1033
1034 if (!merge_names)
1035 merge_names = &fetch_head_file;
1036
f932729c 1037 filename = git_path_fetch_head();
74e8bc59
JH
1038 fd = open(filename, O_RDONLY);
1039 if (fd < 0)
1040 die_errno(_("could not open '%s' for reading"), filename);
1041
1042 if (strbuf_read(merge_names, fd, 0) < 0)
1043 die_errno(_("could not read '%s'"), filename);
1044 if (close(fd) < 0)
1045 die_errno(_("could not close '%s'"), filename);
1046
1047 for (pos = 0; pos < merge_names->len; pos = npos) {
52684310 1048 struct object_id oid;
74e8bc59
JH
1049 char *ptr;
1050 struct commit *commit;
1051
1052 ptr = strchr(merge_names->buf + pos, '\n');
1053 if (ptr)
1054 npos = ptr - merge_names->buf + 1;
1055 else
1056 npos = merge_names->len;
1057
52684310 1058 if (npos - pos < GIT_SHA1_HEXSZ + 2 ||
1059 get_oid_hex(merge_names->buf + pos, &oid))
74e8bc59 1060 commit = NULL; /* bad */
52684310 1061 else if (memcmp(merge_names->buf + pos + GIT_SHA1_HEXSZ, "\t\t", 2))
74e8bc59
JH
1062 continue; /* not-for-merge */
1063 else {
52684310 1064 char saved = merge_names->buf[pos + GIT_SHA1_HEXSZ];
1065 merge_names->buf[pos + GIT_SHA1_HEXSZ] = '\0';
74e8bc59 1066 commit = get_merge_parent(merge_names->buf + pos);
52684310 1067 merge_names->buf[pos + GIT_SHA1_HEXSZ] = saved;
74e8bc59
JH
1068 }
1069 if (!commit) {
1070 if (ptr)
1071 *ptr = '\0';
bef4830e 1072 die(_("not something we can merge in %s: %s"),
74e8bc59
JH
1073 filename, merge_names->buf + pos);
1074 }
1075 remotes = &commit_list_insert(commit, remotes)->next;
1076 }
1077
1078 if (merge_names == &fetch_head_file)
1079 strbuf_release(&fetch_head_file);
1080}
1081
34349dbf
JH
1082static struct commit_list *collect_parents(struct commit *head_commit,
1083 int *head_subsumed,
1cf32f4d
JH
1084 int argc, const char **argv,
1085 struct strbuf *merge_msg)
34349dbf
JH
1086{
1087 int i;
1088 struct commit_list *remoteheads = NULL;
1089 struct commit_list **remotes = &remoteheads;
77038015
JH
1090 struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
1091
1092 if (merge_msg && (!have_message || shortlog_len))
1093 autogen = &merge_names;
34349dbf
JH
1094
1095 if (head_commit)
1096 remotes = &commit_list_insert(head_commit, remotes)->next;
34349dbf 1097
74e8bc59
JH
1098 if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
1099 handle_fetch_head(remotes, autogen);
1100 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1101 } else {
1102 for (i = 0; i < argc; i++) {
1103 struct commit *commit = get_merge_parent(argv[i]);
1104 if (!commit)
1105 help_unknown_ref(argv[i], "merge",
bef4830e 1106 _("not something we can merge"));
74e8bc59
JH
1107 remotes = &commit_list_insert(commit, remotes)->next;
1108 }
1109 remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
1110 if (autogen) {
1111 struct commit_list *p;
1112 for (p = remoteheads; p; p = p->next)
1113 merge_name(merge_remote_util(p->item)->name, autogen);
1114 }
1115 }
1cf32f4d 1116
77038015 1117 if (autogen) {
77038015
JH
1118 prepare_merge_message(autogen, merge_msg);
1119 strbuf_release(autogen);
1cf32f4d
JH
1120 }
1121
1122 return remoteheads;
34349dbf
JH
1123}
1124
1c7b76be
MV
1125int cmd_merge(int argc, const char **argv, const char *prefix)
1126{
52684310 1127 struct object_id result_tree, stash, head_oid;
894642f6 1128 struct commit *head_commit;
f285a2d7 1129 struct strbuf buf = STRBUF_INIT;
17377b62 1130 int i, ret = 0, head_subsumed;
1c7b76be
MV
1131 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1132 struct commit_list *common = NULL;
1133 const char *best_strategy = NULL, *wt_strategy = NULL;
b5d887f9 1134 struct commit_list *remoteheads, *p;
96ec7b1e 1135 void *branch_to_free;
367ff694 1136 int orig_argc = argc;
1c7b76be 1137
da53eec6
NTND
1138 if (argc == 2 && !strcmp(argv[1], "-h"))
1139 usage_with_options(builtin_merge_usage, builtin_merge_options);
1c7b76be
MV
1140
1141 /*
1142 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1143 * current branch.
1144 */
52684310 1145 branch = branch_to_free = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
de3ce210
RS
1146 if (branch)
1147 skip_prefix(branch, "refs/heads/", &branch);
52684310 1148 if (!branch || is_null_oid(&head_oid))
894642f6 1149 head_commit = NULL;
baf18fc2 1150 else
bc83266a 1151 head_commit = lookup_commit_or_die(&head_oid, "HEAD");
1c7b76be 1152
5404c116 1153 init_diff_ui_defaults();
1c7b76be
MV
1154 git_config(git_merge_config, NULL);
1155
0d8fc3ef
JH
1156 if (branch_mergeoptions)
1157 parse_branch_merge_options(branch_mergeoptions);
37782920 1158 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1c7b76be 1159 builtin_merge_usage, 0);
898eacd8
JH
1160 if (shortlog_len < 0)
1161 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
2a22c1b3 1162
99bfc669
JK
1163 if (verbosity < 0 && show_progress == -1)
1164 show_progress = 0;
1165
35d2fffd
JH
1166 if (abort_current_merge) {
1167 int nargc = 2;
1168 const char *nargv[] = {"reset", "--merge", NULL};
1169
042e290d 1170 if (orig_argc != 2)
c7d227df 1171 usage_msg_opt(_("--abort expects no arguments"),
042e290d
CP
1172 builtin_merge_usage, builtin_merge_options);
1173
f932729c 1174 if (!file_exists(git_path_merge_head()))
bacec478 1175 die(_("There is no merge to abort (MERGE_HEAD missing)."));
35d2fffd
JH
1176
1177 /* Invoke 'git reset --merge' */
d5a35c11
NTND
1178 ret = cmd_reset(nargc, nargv, prefix);
1179 goto done;
35d2fffd
JH
1180 }
1181
367ff694
CP
1182 if (continue_current_merge) {
1183 int nargc = 1;
1184 const char *nargv[] = {"commit", NULL};
1185
1186 if (orig_argc != 2)
c7d227df 1187 usage_msg_opt(_("--continue expects no arguments"),
367ff694
CP
1188 builtin_merge_usage, builtin_merge_options);
1189
1190 if (!file_exists(git_path_merge_head()))
1191 die(_("There is no merge in progress (MERGE_HEAD missing)."));
1192
1193 /* Invoke 'git commit' */
1194 ret = cmd_commit(nargc, nargv, prefix);
1195 goto done;
1196 }
1197
2a22c1b3
JH
1198 if (read_cache_unmerged())
1199 die_resolve_conflict("merge");
1200
f932729c 1201 if (file_exists(git_path_merge_head())) {
2a22c1b3
JH
1202 /*
1203 * There is no unmerged entry, don't advise 'git
1204 * add/rm <file>', just 'git commit'.
1205 */
1206 if (advice_resolve_conflict)
bacec478 1207 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
ad5fe377 1208 "Please, commit your changes before you merge."));
2a22c1b3 1209 else
bacec478 1210 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
2a22c1b3 1211 }
f932729c 1212 if (file_exists(git_path_cherry_pick_head())) {
d7e5c0cb 1213 if (advice_resolve_conflict)
f68f1801 1214 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
ad5fe377 1215 "Please, commit your changes before you merge."));
d7e5c0cb 1216 else
f68f1801 1217 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
2a22c1b3
JH
1218 }
1219 resolve_undo_clear();
1220
7f87aff2
TA
1221 if (verbosity < 0)
1222 show_diffstat = 0;
1c7b76be
MV
1223
1224 if (squash) {
a54841e9 1225 if (fast_forward == FF_NO)
bacec478 1226 die(_("You cannot combine --squash with --no-ff."));
1c7b76be
MV
1227 option_commit = 0;
1228 }
1229
00c7e7e7
JH
1230 if (!argc) {
1231 if (default_to_upstream)
1232 argc = setup_with_upstream(&argv);
1233 else
1234 die(_("No commit specified and merge.defaultToUpstream not set."));
1235 } else if (argc == 1 && !strcmp(argv[0], "-")) {
1236 argv[0] = "@{-1}";
4e8115ff 1237 }
00c7e7e7 1238
1c7b76be
MV
1239 if (!argc)
1240 usage_with_options(builtin_merge_usage,
1241 builtin_merge_options);
1242
1faac1ce 1243 if (!head_commit) {
1c7b76be
MV
1244 /*
1245 * If the merged head is a valid one there is no reason
1246 * to forbid "git merge" into a branch yet to be born.
1247 * We do the same for "git pull".
1248 */
52684310 1249 struct object_id *remote_head_oid;
4be636f4 1250 if (squash)
bacec478 1251 die(_("Squash commit into empty head not supported yet"));
a54841e9 1252 if (fast_forward == FF_NO)
bacec478
ÆAB
1253 die(_("Non-fast-forward commit does not make sense into "
1254 "an empty head"));
1cf32f4d
JH
1255 remoteheads = collect_parents(head_commit, &head_subsumed,
1256 argc, argv, NULL);
b84e65d4 1257 if (!remoteheads)
bacec478 1258 die(_("%s - not something we can merge"), argv[0]);
eaa4e59c
JH
1259 if (remoteheads->next)
1260 die(_("Can merge only exactly one commit into empty head"));
52684310 1261 remote_head_oid = &remoteheads->item->object.oid;
1262 read_empty(remote_head_oid->hash, 0);
ae077771 1263 update_ref("initial pull", "HEAD", remote_head_oid, NULL, 0,
1264 UPDATE_REFS_DIE_ON_ERR);
d5a35c11 1265 goto done;
1faac1ce 1266 }
1c7b76be 1267
1faac1ce 1268 /*
b4391657
JH
1269 * All the rest are the commits being merged; prepare
1270 * the standard merge summary message to be appended
1271 * to the given message.
1faac1ce 1272 */
b4391657
JH
1273 remoteheads = collect_parents(head_commit, &head_subsumed,
1274 argc, argv, &merge_msg);
1c7b76be 1275
894642f6 1276 if (!head_commit || !argc)
1c7b76be
MV
1277 usage_with_options(builtin_merge_usage,
1278 builtin_merge_options);
1279
efed0022
SG
1280 if (verify_signatures) {
1281 for (p = remoteheads; p; p = p->next) {
1282 struct commit *commit = p->item;
dc01505f 1283 char hex[GIT_MAX_HEXSZ + 1];
efed0022
SG
1284 struct signature_check signature_check;
1285 memset(&signature_check, 0, sizeof(signature_check));
1286
1287 check_commit_signature(commit, &signature_check);
1288
ed1c9977 1289 find_unique_abbrev_r(hex, commit->object.oid.hash, DEFAULT_ABBREV);
efed0022
SG
1290 switch (signature_check.result) {
1291 case 'G':
1292 break;
eb307ae7
SG
1293 case 'U':
1294 die(_("Commit %s has an untrusted GPG signature, "
1295 "allegedly by %s."), hex, signature_check.signer);
efed0022
SG
1296 case 'B':
1297 die(_("Commit %s has a bad GPG signature "
1298 "allegedly by %s."), hex, signature_check.signer);
1299 default: /* 'N' */
1300 die(_("Commit %s does not have a GPG signature."), hex);
1301 }
1302 if (verbosity >= 0 && signature_check.result == 'G')
1303 printf(_("Commit %s has a good GPG signature by %s\n"),
1304 hex, signature_check.signer);
1305
01e57b5d 1306 signature_check_clear(&signature_check);
efed0022
SG
1307 }
1308 }
1309
1c7b76be 1310 strbuf_addstr(&buf, "merge");
b5d887f9
JH
1311 for (p = remoteheads; p; p = p->next)
1312 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1c7b76be
MV
1313 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1314 strbuf_reset(&buf);
1315
b5d887f9
JH
1316 for (p = remoteheads; p; p = p->next) {
1317 struct commit *commit = p->item;
ae8e4c9c 1318 strbuf_addf(&buf, "GITHEAD_%s",
c368dde9 1319 oid_to_hex(&commit->object.oid));
b5d887f9 1320 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1c7b76be 1321 strbuf_reset(&buf);
a54841e9 1322 if (fast_forward != FF_ONLY &&
b5c9f1c1 1323 merge_remote_util(commit) &&
fab47d05 1324 merge_remote_util(commit)->obj &&
d82829b6 1325 merge_remote_util(commit)->obj->type == OBJ_TAG)
a54841e9 1326 fast_forward = FF_NO;
1c7b76be
MV
1327 }
1328
f8246281
JH
1329 if (option_edit < 0)
1330 option_edit = default_edit_option();
1331
1c7b76be 1332 if (!use_strategies) {
e78cbf8c
JH
1333 if (!remoteheads)
1334 ; /* already up-to-date */
1335 else if (!remoteheads->next)
1c7b76be
MV
1336 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1337 else
1338 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1339 }
1340
1341 for (i = 0; i < use_strategies_nr; i++) {
1342 if (use_strategies[i]->attr & NO_FAST_FORWARD)
a54841e9 1343 fast_forward = FF_NO;
1c7b76be
MV
1344 if (use_strategies[i]->attr & NO_TRIVIAL)
1345 allow_trivial = 0;
1346 }
1347
e78cbf8c
JH
1348 if (!remoteheads)
1349 ; /* already up-to-date */
1350 else if (!remoteheads->next)
2ce406cc 1351 common = get_merge_bases(head_commit, remoteheads->item);
1c7b76be
MV
1352 else {
1353 struct commit_list *list = remoteheads;
894642f6 1354 commit_list_insert(head_commit, &list);
1c7b76be
MV
1355 common = get_octopus_merge_bases(list);
1356 free(list);
1357 }
1358
ae077771 1359 update_ref("updating ORIG_HEAD", "ORIG_HEAD",
1360 &head_commit->object.oid, NULL, 0, UPDATE_REFS_DIE_ON_ERR);
1c7b76be 1361
e379fdf3
JH
1362 if (remoteheads && !common) {
1363 /* No common ancestors found. */
1364 if (!allow_unrelated_histories)
1365 die(_("refusing to merge unrelated histories"));
1366 /* otherwise, we need a real merge. */
1367 } else if (!remoteheads ||
e78cbf8c
JH
1368 (!remoteheads->next && !common->next &&
1369 common->item == remoteheads->item)) {
1c7b76be
MV
1370 /*
1371 * If head can reach all the merge then we are up to date.
1372 * but first the most common case of merging one remote.
1373 */
7560f547 1374 finish_up_to_date(_("Already up to date."));
d5a35c11 1375 goto done;
a54841e9 1376 } else if (fast_forward != FF_NO && !remoteheads->next &&
1c7b76be 1377 !common->next &&
c368dde9 1378 !oidcmp(&common->item->object.oid, &head_commit->object.oid)) {
1c7b76be 1379 /* Again the most common case of merging one remote. */
f285a2d7 1380 struct strbuf msg = STRBUF_INIT;
ae8e4c9c 1381 struct commit *commit;
1c7b76be 1382
d59f765a 1383 if (verbosity >= 0) {
ef2ed501
JK
1384 printf(_("Updating %s..%s\n"),
1385 find_unique_abbrev(head_commit->object.oid.hash,
1386 DEFAULT_ABBREV),
1387 find_unique_abbrev(remoteheads->item->object.oid.hash,
1388 DEFAULT_ABBREV));
d59f765a 1389 }
a75d7b54 1390 strbuf_addstr(&msg, "Fast-forward");
1c7b76be
MV
1391 if (have_message)
1392 strbuf_addstr(&msg,
1393 " (no commit created; -m option ignored)");
ae8e4c9c 1394 commit = remoteheads->item;
b7f7c079 1395 if (!commit) {
d5a35c11
NTND
1396 ret = 1;
1397 goto done;
1398 }
1c7b76be 1399
f06e90da 1400 if (checkout_fast_forward(&head_commit->object.oid,
1401 &commit->object.oid,
db699a8a 1402 overwrite_ignore)) {
d5a35c11
NTND
1403 ret = 1;
1404 goto done;
1405 }
1c7b76be 1406
52684310 1407 finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
1c7b76be 1408 drop_save();
d5a35c11 1409 goto done;
1c7b76be
MV
1410 } else if (!remoteheads->next && common->next)
1411 ;
1412 /*
a75d7b54 1413 * We are not doing octopus and not fast-forward. Need
1c7b76be
MV
1414 * a real merge.
1415 */
1416 else if (!remoteheads->next && !common->next && option_commit) {
1417 /*
a75d7b54 1418 * We are not doing octopus, not fast-forward, and have
1c7b76be
MV
1419 * only one common.
1420 */
1421 refresh_cache(REFRESH_QUIET);
a54841e9 1422 if (allow_trivial && fast_forward != FF_ONLY) {
1c7b76be 1423 /* See if it is really trivial. */
f9bc573f 1424 git_committer_info(IDENT_STRICT);
bacec478 1425 printf(_("Trying really trivial in-index merge...\n"));
52684310 1426 if (!read_tree_trivial(&common->item->object.oid,
1427 &head_commit->object.oid,
1428 &remoteheads->item->object.oid)) {
4c57bd27 1429 ret = merge_trivial(head_commit, remoteheads);
d5a35c11
NTND
1430 goto done;
1431 }
bacec478 1432 printf(_("Nope.\n"));
1c7b76be
MV
1433 }
1434 } else {
1435 /*
1436 * An octopus. If we can reach all the remote we are up
1437 * to date.
1438 */
1439 int up_to_date = 1;
1440 struct commit_list *j;
1441
1442 for (j = remoteheads; j; j = j->next) {
1443 struct commit_list *common_one;
1444
1445 /*
1446 * Here we *have* to calculate the individual
1447 * merge_bases again, otherwise "git merge HEAD^
1448 * HEAD^^" would be missed.
1449 */
2ce406cc 1450 common_one = get_merge_bases(head_commit, j->item);
c368dde9 1451 if (oidcmp(&common_one->item->object.oid, &j->item->object.oid)) {
1c7b76be
MV
1452 up_to_date = 0;
1453 break;
1454 }
1455 }
1456 if (up_to_date) {
7560f547 1457 finish_up_to_date(_("Already up to date. Yeeah!"));
d5a35c11 1458 goto done;
1c7b76be
MV
1459 }
1460 }
1461
a54841e9 1462 if (fast_forward == FF_ONLY)
bacec478 1463 die(_("Not possible to fast-forward, aborting."));
13474835 1464
1c7b76be 1465 /* We are going to make a new commit. */
f9bc573f 1466 git_committer_info(IDENT_STRICT);
1c7b76be
MV
1467
1468 /*
1469 * At this point, we need a real merge. No matter what strategy
1470 * we use, it would operate on the index, possibly affecting the
1471 * working tree, and when resolved cleanly, have the desired
1472 * tree in the index -- this means that the index must be in
1473 * sync with the head commit. The strategies are responsible
1474 * to ensure this.
1475 */
b4fd9406
NTND
1476 if (use_strategies_nr == 1 ||
1477 /*
1478 * Stash away the local changes so that we can try more than one.
1479 */
52684310 1480 save_state(&stash))
1481 oidclr(&stash);
1c7b76be
MV
1482
1483 for (i = 0; i < use_strategies_nr; i++) {
1484 int ret;
1485 if (i) {
bacec478 1486 printf(_("Rewinding the tree to pristine...\n"));
52684310 1487 restore_state(&head_commit->object.oid, &stash);
1c7b76be
MV
1488 }
1489 if (use_strategies_nr != 1)
bacec478 1490 printf(_("Trying merge strategy %s...\n"),
1c7b76be
MV
1491 use_strategies[i]->name);
1492 /*
1493 * Remember which strategy left the state in the working
1494 * tree.
1495 */
1496 wt_strategy = use_strategies[i]->name;
1497
1498 ret = try_merge_strategy(use_strategies[i]->name,
4c57bd27 1499 common, remoteheads,
b4391657 1500 head_commit);
1c7b76be
MV
1501 if (!option_commit && !ret) {
1502 merge_was_ok = 1;
1503 /*
1504 * This is necessary here just to avoid writing
1505 * the tree, but later we will *not* exit with
1506 * status code 1 because merge_was_ok is set.
1507 */
1508 ret = 1;
1509 }
1510
1511 if (ret) {
1512 /*
1513 * The backend exits with 1 when conflicts are
1514 * left to be resolved, with 2 when it does not
1515 * handle the given merge at all.
1516 */
1517 if (ret == 1) {
1518 int cnt = evaluate_result();
1519
1520 if (best_cnt <= 0 || cnt <= best_cnt) {
1521 best_strategy = use_strategies[i]->name;
1522 best_cnt = cnt;
1523 }
1524 }
1525 if (merge_was_ok)
1526 break;
1527 else
1528 continue;
1529 }
1530
1531 /* Automerge succeeded. */
52684310 1532 write_tree_trivial(&result_tree);
1c7b76be
MV
1533 automerge_was_ok = 1;
1534 break;
1535 }
1536
1537 /*
1538 * If we have a resulting tree, that means the strategy module
1539 * auto resolved the merge cleanly.
1540 */
d5a35c11 1541 if (automerge_was_ok) {
e78cbf8c
JH
1542 ret = finish_automerge(head_commit, head_subsumed,
1543 common, remoteheads,
52684310 1544 &result_tree, wt_strategy);
d5a35c11
NTND
1545 goto done;
1546 }
1c7b76be
MV
1547
1548 /*
1549 * Pick the result from the best strategy and have the user fix
1550 * it up.
1551 */
1552 if (!best_strategy) {
52684310 1553 restore_state(&head_commit->object.oid, &stash);
1c7b76be
MV
1554 if (use_strategies_nr > 1)
1555 fprintf(stderr,
bacec478 1556 _("No merge strategy handled the merge.\n"));
1c7b76be 1557 else
bacec478 1558 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1c7b76be 1559 use_strategies[0]->name);
d5a35c11
NTND
1560 ret = 2;
1561 goto done;
1c7b76be
MV
1562 } else if (best_strategy == wt_strategy)
1563 ; /* We already have its result in the working tree. */
1564 else {
bacec478 1565 printf(_("Rewinding the tree to pristine...\n"));
52684310 1566 restore_state(&head_commit->object.oid, &stash);
bacec478 1567 printf(_("Using the %s to prepare resolving by hand.\n"),
1c7b76be 1568 best_strategy);
4c57bd27 1569 try_merge_strategy(best_strategy, common, remoteheads,
b4391657 1570 head_commit);
1c7b76be
MV
1571 }
1572
1573 if (squash)
4c57bd27 1574 finish(head_commit, remoteheads, NULL, NULL);
66f4b98a 1575 else
4c57bd27 1576 write_merge_state(remoteheads);
1c7b76be 1577
d5a35c11 1578 if (merge_was_ok)
bacec478
ÆAB
1579 fprintf(stderr, _("Automatic merge went well; "
1580 "stopped before committing as requested\n"));
d5a35c11 1581 else
08e3ce5a 1582 ret = suggest_conflicts();
d5a35c11
NTND
1583
1584done:
96ec7b1e 1585 free(branch_to_free);
d5a35c11 1586 return ret;
1c7b76be 1587}