add 'git credential' plumbing command
[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"
12#include "run-command.h"
13#include "diff.h"
14#include "refs.h"
15#include "commit.h"
16#include "diffcore.h"
17#include "revision.h"
18#include "unpack-trees.h"
19#include "cache-tree.h"
20#include "dir.h"
21#include "utf8.h"
22#include "log-tree.h"
23#include "color.h"
fcab40a3 24#include "rerere.h"
87091b49 25#include "help.h"
18668f53 26#include "merge-recursive.h"
cfc5789a 27#include "resolve-undo.h"
93e535a5 28#include "remote.h"
898eacd8 29#include "fmt-merge-msg.h"
ba3c69a9 30#include "gpg-interface.h"
1c7b76be
MV
31
32#define DEFAULT_TWOHEAD (1<<0)
33#define DEFAULT_OCTOPUS (1<<1)
34#define NO_FAST_FORWARD (1<<2)
35#define NO_TRIVIAL (1<<3)
36
37struct strategy {
38 const char *name;
39 unsigned attr;
40};
41
42static const char * const builtin_merge_usage[] = {
93e535a5 43 "git merge [options] [<commit>...]",
c395c25b
JH
44 "git merge [options] <msg> HEAD <commit>",
45 "git merge --abort",
1c7b76be
MV
46 NULL
47};
48
898eacd8 49static int show_diffstat = 1, shortlog_len = -1, squash;
1c7b76be 50static int option_commit = 1, allow_fast_forward = 1;
f8246281 51static int fast_forward_only, option_edit = -1;
1c7b76be 52static int allow_trivial = 1, have_message;
c1d7036b 53static int overwrite_ignore = 1;
2c47789d 54static struct strbuf merge_msg = STRBUF_INIT;
1c7b76be
MV
55static struct strategy **use_strategies;
56static size_t use_strategies_nr, use_strategies_alloc;
8cc5b290
AP
57static const char **xopts;
58static size_t xopts_nr, xopts_alloc;
1c7b76be 59static const char *branch;
0d8fc3ef 60static char *branch_mergeoptions;
7610fa57 61static int option_renormalize;
7f87aff2 62static int verbosity;
cb6020bb 63static int allow_rerere_auto;
35d2fffd 64static int abort_current_merge;
99bfc669 65static int show_progress = -1;
93e535a5 66static int default_to_upstream;
ba3c69a9 67static const char *sign_commit;
1c7b76be
MV
68
69static struct strategy all_strategy[] = {
1c7b76be
MV
70 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
71 { "octopus", DEFAULT_OCTOPUS },
72 { "resolve", 0 },
1c7b76be
MV
73 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
74 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
75};
76
77static const char *pull_twohead, *pull_octopus;
78
79static int option_parse_message(const struct option *opt,
80 const char *arg, int unset)
81{
82 struct strbuf *buf = opt->value;
83
84 if (unset)
85 strbuf_setlen(buf, 0);
74f5b7fb 86 else if (arg) {
ce9d823b 87 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
1c7b76be 88 have_message = 1;
74f5b7fb 89 } else
bacec478 90 return error(_("switch `m' requires a value"));
1c7b76be
MV
91 return 0;
92}
93
94static struct strategy *get_strategy(const char *name)
95{
96 int i;
87091b49
MV
97 struct strategy *ret;
98 static struct cmdnames main_cmds, other_cmds;
e321180e 99 static int loaded;
1c7b76be
MV
100
101 if (!name)
102 return NULL;
103
104 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
105 if (!strcmp(name, all_strategy[i].name))
106 return &all_strategy[i];
1719b5e4 107
e321180e 108 if (!loaded) {
87091b49 109 struct cmdnames not_strategies;
e321180e 110 loaded = 1;
87091b49 111
87091b49 112 memset(&not_strategies, 0, sizeof(struct cmdnames));
e321180e 113 load_command_list("git-merge-", &main_cmds, &other_cmds);
87091b49
MV
114 for (i = 0; i < main_cmds.cnt; i++) {
115 int j, found = 0;
116 struct cmdname *ent = main_cmds.names[i];
117 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
118 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
119 && !all_strategy[j].name[ent->len])
120 found = 1;
121 if (!found)
122 add_cmdname(&not_strategies, ent->name, ent->len);
87091b49 123 }
ed874656 124 exclude_cmds(&main_cmds, &not_strategies);
87091b49
MV
125 }
126 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
bacec478
ÆAB
127 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
128 fprintf(stderr, _("Available strategies are:"));
131f9a10
JH
129 for (i = 0; i < main_cmds.cnt; i++)
130 fprintf(stderr, " %s", main_cmds.names[i]->name);
131 fprintf(stderr, ".\n");
132 if (other_cmds.cnt) {
bacec478 133 fprintf(stderr, _("Available custom strategies are:"));
131f9a10
JH
134 for (i = 0; i < other_cmds.cnt; i++)
135 fprintf(stderr, " %s", other_cmds.names[i]->name);
136 fprintf(stderr, ".\n");
137 }
87091b49
MV
138 exit(1);
139 }
140
19d4b416 141 ret = xcalloc(1, sizeof(struct strategy));
87091b49 142 ret->name = xstrdup(name);
52b48ef1 143 ret->attr = NO_TRIVIAL;
87091b49 144 return ret;
1c7b76be
MV
145}
146
147static void append_strategy(struct strategy *s)
148{
149 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
150 use_strategies[use_strategies_nr++] = s;
151}
152
153static int option_parse_strategy(const struct option *opt,
154 const char *name, int unset)
155{
1c7b76be
MV
156 if (unset)
157 return 0;
158
1719b5e4 159 append_strategy(get_strategy(name));
1c7b76be
MV
160 return 0;
161}
162
8cc5b290
AP
163static int option_parse_x(const struct option *opt,
164 const char *arg, int unset)
165{
166 if (unset)
167 return 0;
168
169 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
170 xopts[xopts_nr++] = xstrdup(arg);
171 return 0;
172}
173
1c7b76be
MV
174static int option_parse_n(const struct option *opt,
175 const char *arg, int unset)
176{
177 show_diffstat = unset;
178 return 0;
179}
180
181static struct option builtin_merge_options[] = {
182 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
183 "do not show a diffstat at the end of the merge",
184 PARSE_OPT_NOARG, option_parse_n },
185 OPT_BOOLEAN(0, "stat", &show_diffstat,
186 "show a diffstat at the end of the merge"),
187 OPT_BOOLEAN(0, "summary", &show_diffstat, "(synonym to --stat)"),
96e9420c
RR
188 { OPTION_INTEGER, 0, "log", &shortlog_len, "n",
189 "add (at most <n>) entries from shortlog to merge commit message",
190 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
1c7b76be
MV
191 OPT_BOOLEAN(0, "squash", &squash,
192 "create a single commit instead of doing a merge"),
193 OPT_BOOLEAN(0, "commit", &option_commit,
194 "perform a commit if the merge succeeds (default)"),
f8246281 195 OPT_BOOL('e', "edit", &option_edit,
66f4b98a 196 "edit message before committing"),
1c7b76be 197 OPT_BOOLEAN(0, "ff", &allow_fast_forward,
a75d7b54 198 "allow fast-forward (default)"),
13474835 199 OPT_BOOLEAN(0, "ff-only", &fast_forward_only,
4d8c3258 200 "abort if fast-forward is not possible"),
cb6020bb 201 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
1c7b76be
MV
202 OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
203 "merge strategy to use", option_parse_strategy),
8cc5b290
AP
204 OPT_CALLBACK('X', "strategy-option", &xopts, "option=value",
205 "option for selected merge strategy", option_parse_x),
23c6a803 206 OPT_CALLBACK('m', "message", &merge_msg, "message",
3f406175 207 "merge commit message (for a non-fast-forward merge)",
1c7b76be 208 option_parse_message),
7f87aff2 209 OPT__VERBOSITY(&verbosity),
35d2fffd
JH
210 OPT_BOOLEAN(0, "abort", &abort_current_merge,
211 "abort the current in-progress merge"),
99bfc669 212 OPT_SET_INT(0, "progress", &show_progress, "force progress reporting", 1),
ba3c69a9
JH
213 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, "key id",
214 "GPG sign commit", PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
c1d7036b 215 OPT_BOOLEAN(0, "overwrite-ignore", &overwrite_ignore, "update ignored files (default)"),
1c7b76be
MV
216 OPT_END()
217};
218
219/* Cleans up metadata that is uninteresting after a succeeded merge. */
220static void drop_save(void)
221{
222 unlink(git_path("MERGE_HEAD"));
223 unlink(git_path("MERGE_MSG"));
cf10f9fd 224 unlink(git_path("MERGE_MODE"));
1c7b76be
MV
225}
226
b4fd9406 227static int save_state(unsigned char *stash)
1c7b76be
MV
228{
229 int len;
230 struct child_process cp;
231 struct strbuf buffer = STRBUF_INIT;
232 const char *argv[] = {"stash", "create", NULL};
233
234 memset(&cp, 0, sizeof(cp));
235 cp.argv = argv;
236 cp.out = -1;
237 cp.git_cmd = 1;
238
239 if (start_command(&cp))
bacec478 240 die(_("could not run stash."));
1c7b76be
MV
241 len = strbuf_read(&buffer, cp.out, 1024);
242 close(cp.out);
243
244 if (finish_command(&cp) || len < 0)
bacec478 245 die(_("stash failed"));
b4fd9406
NTND
246 else if (!len) /* no changes */
247 return -1;
1c7b76be
MV
248 strbuf_setlen(&buffer, buffer.len-1);
249 if (get_sha1(buffer.buf, stash))
bacec478 250 die(_("not a valid object: %s"), buffer.buf);
b4fd9406 251 return 0;
1c7b76be
MV
252}
253
172b6428
CB
254static void read_empty(unsigned const char *sha1, int verbose)
255{
256 int i = 0;
257 const char *args[7];
258
259 args[i++] = "read-tree";
260 if (verbose)
261 args[i++] = "-v";
262 args[i++] = "-m";
263 args[i++] = "-u";
264 args[i++] = EMPTY_TREE_SHA1_HEX;
265 args[i++] = sha1_to_hex(sha1);
266 args[i] = NULL;
267
268 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 269 die(_("read-tree failed"));
172b6428
CB
270}
271
1c7b76be
MV
272static void reset_hard(unsigned const char *sha1, int verbose)
273{
274 int i = 0;
275 const char *args[6];
276
277 args[i++] = "read-tree";
278 if (verbose)
279 args[i++] = "-v";
280 args[i++] = "--reset";
281 args[i++] = "-u";
282 args[i++] = sha1_to_hex(sha1);
283 args[i] = NULL;
284
285 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 286 die(_("read-tree failed"));
1c7b76be
MV
287}
288
894642f6
NTND
289static void restore_state(const unsigned char *head,
290 const unsigned char *stash)
1c7b76be 291{
f285a2d7 292 struct strbuf sb = STRBUF_INIT;
1c7b76be
MV
293 const char *args[] = { "stash", "apply", NULL, NULL };
294
295 if (is_null_sha1(stash))
296 return;
297
298 reset_hard(head, 1);
299
1c7b76be
MV
300 args[2] = sha1_to_hex(stash);
301
302 /*
303 * It is OK to ignore error here, for example when there was
304 * nothing to restore.
305 */
306 run_command_v_opt(args, RUN_GIT_CMD);
307
308 strbuf_release(&sb);
309 refresh_cache(REFRESH_QUIET);
310}
311
312/* This is called when no merge was necessary. */
313static void finish_up_to_date(const char *msg)
314{
7f87aff2 315 if (verbosity >= 0)
bacec478 316 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
1c7b76be
MV
317 drop_save();
318}
319
4c57bd27 320static void squash_message(struct commit *commit, struct commit_list *remoteheads)
1c7b76be
MV
321{
322 struct rev_info rev;
f285a2d7 323 struct strbuf out = STRBUF_INIT;
1c7b76be 324 struct commit_list *j;
418c9b17 325 const char *filename;
1c7b76be 326 int fd;
dd2e794a 327 struct pretty_print_context ctx = {0};
1c7b76be 328
bacec478 329 printf(_("Squash commit -- not updating HEAD\n"));
418c9b17
JN
330 filename = git_path("SQUASH_MSG");
331 fd = open(filename, O_WRONLY | O_CREAT, 0666);
1c7b76be 332 if (fd < 0)
418c9b17 333 die_errno(_("Could not write to '%s'"), filename);
1c7b76be
MV
334
335 init_revisions(&rev, NULL);
336 rev.ignore_merges = 1;
337 rev.commit_format = CMIT_FMT_MEDIUM;
338
1c7b76be
MV
339 commit->object.flags |= UNINTERESTING;
340 add_pending_object(&rev, &commit->object, NULL);
341
342 for (j = remoteheads; j; j = j->next)
343 add_pending_object(&rev, &j->item->object, NULL);
344
345 setup_revisions(0, NULL, &rev, NULL);
346 if (prepare_revision_walk(&rev))
bacec478 347 die(_("revision walk setup failed"));
1c7b76be 348
dd2e794a
TR
349 ctx.abbrev = rev.abbrev;
350 ctx.date_mode = rev.date_mode;
6bf13944 351 ctx.fmt = rev.commit_format;
dd2e794a 352
1c7b76be
MV
353 strbuf_addstr(&out, "Squashed commit of the following:\n");
354 while ((commit = get_revision(&rev)) != NULL) {
355 strbuf_addch(&out, '\n');
356 strbuf_addf(&out, "commit %s\n",
357 sha1_to_hex(commit->object.sha1));
6bf13944 358 pretty_print_commit(&ctx, commit, &out);
1c7b76be 359 }
47d32af2 360 if (write(fd, out.buf, out.len) < 0)
bacec478 361 die_errno(_("Writing SQUASH_MSG"));
47d32af2 362 if (close(fd))
bacec478 363 die_errno(_("Finishing SQUASH_MSG"));
1c7b76be
MV
364 strbuf_release(&out);
365}
366
894642f6 367static void finish(struct commit *head_commit,
4c57bd27 368 struct commit_list *remoteheads,
894642f6 369 const unsigned char *new_head, const char *msg)
1c7b76be 370{
f285a2d7 371 struct strbuf reflog_message = STRBUF_INIT;
894642f6 372 const unsigned char *head = head_commit->object.sha1;
1c7b76be 373
1c7b76be
MV
374 if (!msg)
375 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
376 else {
7f87aff2
TA
377 if (verbosity >= 0)
378 printf("%s\n", msg);
1c7b76be
MV
379 strbuf_addf(&reflog_message, "%s: %s",
380 getenv("GIT_REFLOG_ACTION"), msg);
381 }
382 if (squash) {
4c57bd27 383 squash_message(head_commit, remoteheads);
1c7b76be 384 } else {
7f87aff2 385 if (verbosity >= 0 && !merge_msg.len)
bacec478 386 printf(_("No merge message -- not updating HEAD\n"));
1c7b76be
MV
387 else {
388 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
389 update_ref(reflog_message.buf, "HEAD",
390 new_head, head, 0,
391 DIE_ON_ERR);
392 /*
393 * We ignore errors in 'gc --auto', since the
394 * user should see them.
395 */
396 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
397 }
398 }
399 if (new_head && show_diffstat) {
400 struct diff_options opts;
401 diff_setup(&opts);
7a7159ac 402 opts.stat_width = -1; /* use full terminal width */
df44483a 403 opts.stat_graph_width = -1; /* respect statGraphWidth config */
1c7b76be
MV
404 opts.output_format |=
405 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
406 opts.detect_rename = DIFF_DETECT_RENAME;
1c7b76be 407 if (diff_setup_done(&opts) < 0)
bacec478 408 die(_("diff_setup_done failed"));
1c7b76be
MV
409 diff_tree_sha1(head, new_head, "", &opts);
410 diffcore_std(&opts);
411 diff_flush(&opts);
412 }
413
414 /* Run a post-merge hook */
ae98a008 415 run_hook(NULL, "post-merge", squash ? "1" : "0", NULL);
1c7b76be
MV
416
417 strbuf_release(&reflog_message);
418}
419
420/* Get the name for the merge commit's message. */
421static void merge_name(const char *remote, struct strbuf *msg)
422{
ae8e4c9c 423 struct commit *remote_head;
c6893323 424 unsigned char branch_head[20];
f285a2d7 425 struct strbuf buf = STRBUF_INIT;
c9717ee9 426 struct strbuf bname = STRBUF_INIT;
1c7b76be 427 const char *ptr;
751c5974 428 char *found_ref;
1c7b76be
MV
429 int len, early;
430
a552de75
JH
431 strbuf_branchname(&bname, remote);
432 remote = bname.buf;
c9717ee9 433
1c7b76be 434 memset(branch_head, 0, sizeof(branch_head));
ae8e4c9c 435 remote_head = get_merge_parent(remote);
1c7b76be 436 if (!remote_head)
bacec478 437 die(_("'%s' does not point to a commit"), remote);
1c7b76be 438
751c5974
JK
439 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
440 if (!prefixcmp(found_ref, "refs/heads/")) {
441 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
442 sha1_to_hex(branch_head), remote);
443 goto cleanup;
444 }
57b58db7
JH
445 if (!prefixcmp(found_ref, "refs/tags/")) {
446 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
447 sha1_to_hex(branch_head), remote);
448 goto cleanup;
449 }
69a8b7c7 450 if (!prefixcmp(found_ref, "refs/remotes/")) {
13931236 451 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
69a8b7c7
JK
452 sha1_to_hex(branch_head), remote);
453 goto cleanup;
454 }
1c7b76be
MV
455 }
456
457 /* See if remote matches <name>^^^.. or <name>~<number> */
458 for (len = 0, ptr = remote + strlen(remote);
459 remote < ptr && ptr[-1] == '^';
460 ptr--)
461 len++;
462 if (len)
463 early = 1;
464 else {
465 early = 0;
466 ptr = strrchr(remote, '~');
467 if (ptr) {
468 int seen_nonzero = 0;
469
470 len++; /* count ~ */
471 while (*++ptr && isdigit(*ptr)) {
472 seen_nonzero |= (*ptr != '0');
473 len++;
474 }
475 if (*ptr)
476 len = 0; /* not ...~<number> */
477 else if (seen_nonzero)
478 early = 1;
479 else if (len == 1)
480 early = 1; /* "name~" is "name~1"! */
481 }
482 }
483 if (len) {
484 struct strbuf truname = STRBUF_INIT;
485 strbuf_addstr(&truname, "refs/heads/");
486 strbuf_addstr(&truname, remote);
9b6bf4d5 487 strbuf_setlen(&truname, truname.len - len);
c6893323 488 if (ref_exists(truname.buf)) {
1c7b76be
MV
489 strbuf_addf(msg,
490 "%s\t\tbranch '%s'%s of .\n",
ae8e4c9c 491 sha1_to_hex(remote_head->object.sha1),
9b6bf4d5 492 truname.buf + 11,
1c7b76be 493 (early ? " (early part)" : ""));
c9717ee9
JH
494 strbuf_release(&truname);
495 goto cleanup;
1c7b76be
MV
496 }
497 }
498
499 if (!strcmp(remote, "FETCH_HEAD") &&
500 !access(git_path("FETCH_HEAD"), R_OK)) {
418c9b17 501 const char *filename;
1c7b76be 502 FILE *fp;
f285a2d7 503 struct strbuf line = STRBUF_INIT;
1c7b76be
MV
504 char *ptr;
505
418c9b17
JN
506 filename = git_path("FETCH_HEAD");
507 fp = fopen(filename, "r");
1c7b76be 508 if (!fp)
bacec478 509 die_errno(_("could not open '%s' for reading"),
418c9b17 510 filename);
1c7b76be
MV
511 strbuf_getline(&line, fp, '\n');
512 fclose(fp);
513 ptr = strstr(line.buf, "\tnot-for-merge\t");
514 if (ptr)
515 strbuf_remove(&line, ptr-line.buf+1, 13);
516 strbuf_addbuf(msg, &line);
517 strbuf_release(&line);
c9717ee9 518 goto cleanup;
1c7b76be
MV
519 }
520 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
ae8e4c9c 521 sha1_to_hex(remote_head->object.sha1), 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));
0d8fc3ef
JH
538 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
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
1c7b76be
MV
551 if (branch && !prefixcmp(k, "branch.") &&
552 !prefixcmp(k + 7, branch) &&
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) {
570 allow_fast_forward = boolval;
571 } else if (v && !strcmp(v, "only")) {
572 allow_fast_forward = 1;
573 fast_forward_only = 1;
574 } /* do not barf on values from future versions of git */
575 return 0;
93e535a5
JH
576 } else if (!strcmp(k, "merge.defaulttoupstream")) {
577 default_to_upstream = git_config_bool(k, v);
578 return 0;
96e9420c 579 }
ba3c69a9 580
898eacd8 581 status = fmt_merge_msg_config(k, v, cb);
5de89d3a
JH
582 if (status)
583 return status;
ba3c69a9 584 status = git_gpg_config(k, v, NULL);
898eacd8
JH
585 if (status)
586 return status;
1c7b76be
MV
587 return git_diff_ui_config(k, v, cb);
588}
589
590static int read_tree_trivial(unsigned char *common, unsigned char *head,
591 unsigned char *one)
592{
593 int i, nr_trees = 0;
594 struct tree *trees[MAX_UNPACK_TREES];
595 struct tree_desc t[MAX_UNPACK_TREES];
596 struct unpack_trees_options opts;
597
598 memset(&opts, 0, sizeof(opts));
599 opts.head_idx = 2;
600 opts.src_index = &the_index;
601 opts.dst_index = &the_index;
602 opts.update = 1;
603 opts.verbose_update = 1;
604 opts.trivial_merges_only = 1;
605 opts.merge = 1;
606 trees[nr_trees] = parse_tree_indirect(common);
607 if (!trees[nr_trees++])
608 return -1;
609 trees[nr_trees] = parse_tree_indirect(head);
610 if (!trees[nr_trees++])
611 return -1;
612 trees[nr_trees] = parse_tree_indirect(one);
613 if (!trees[nr_trees++])
614 return -1;
615 opts.fn = threeway_merge;
616 cache_tree_free(&active_cache_tree);
617 for (i = 0; i < nr_trees; i++) {
618 parse_tree(trees[i]);
619 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
620 }
621 if (unpack_trees(nr_trees, t, &opts))
622 return -1;
623 return 0;
624}
625
626static void write_tree_trivial(unsigned char *sha1)
627{
628 if (write_cache_as_tree(sha1, 0, NULL))
bacec478 629 die(_("git write-tree failed to write a tree"));
1c7b76be
MV
630}
631
16180734
JK
632static const char *merge_argument(struct commit *commit)
633{
634 if (commit)
635 return sha1_to_hex(commit->object.sha1);
636 else
637 return EMPTY_TREE_SHA1_HEX;
638}
639
67ac1e1d
JN
640int try_merge_command(const char *strategy, size_t xopts_nr,
641 const char **xopts, struct commit_list *common,
c674d052 642 const char *head_arg, struct commit_list *remotes)
1c7b76be
MV
643{
644 const char **args;
8cc5b290 645 int i = 0, x = 0, ret;
1c7b76be 646 struct commit_list *j;
f285a2d7 647 struct strbuf buf = STRBUF_INIT;
3f9083cd
CC
648
649 args = xmalloc((4 + xopts_nr + commit_list_count(common) +
650 commit_list_count(remotes)) * sizeof(char *));
651 strbuf_addf(&buf, "merge-%s", strategy);
652 args[i++] = buf.buf;
653 for (x = 0; x < xopts_nr; x++) {
654 char *s = xmalloc(strlen(xopts[x])+2+1);
655 strcpy(s, "--");
656 strcpy(s+2, xopts[x]);
657 args[i++] = s;
658 }
659 for (j = common; j; j = j->next)
16180734 660 args[i++] = xstrdup(merge_argument(j->item));
3f9083cd
CC
661 args[i++] = "--";
662 args[i++] = head_arg;
663 for (j = remotes; j; j = j->next)
16180734 664 args[i++] = xstrdup(merge_argument(j->item));
3f9083cd
CC
665 args[i] = NULL;
666 ret = run_command_v_opt(args, RUN_GIT_CMD);
667 strbuf_release(&buf);
668 i = 1;
669 for (x = 0; x < xopts_nr; x++)
670 free((void *)args[i++]);
671 for (j = common; j; j = j->next)
672 free((void *)args[i++]);
673 i += 2;
674 for (j = remotes; j; j = j->next)
675 free((void *)args[i++]);
676 free(args);
677 discard_cache();
678 if (read_cache() < 0)
bacec478 679 die(_("failed to read the cache"));
3f9083cd
CC
680 resolve_undo_clear();
681
682 return ret;
683}
684
685static int try_merge_strategy(const char *strategy, struct commit_list *common,
4c57bd27 686 struct commit_list *remoteheads,
894642f6 687 struct commit *head, const char *head_arg)
3f9083cd 688{
668f26ff
MV
689 int index_fd;
690 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
691
692 index_fd = hold_locked_index(lock, 1);
693 refresh_cache(REFRESH_QUIET);
694 if (active_cache_changed &&
695 (write_cache(index_fd, active_cache, active_nr) ||
696 commit_locked_index(lock)))
bacec478 697 return error(_("Unable to write index."));
668f26ff 698 rollback_lock_file(lock);
1c7b76be 699
18668f53 700 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
3f9083cd 701 int clean, x;
18668f53
MV
702 struct commit *result;
703 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
704 int index_fd;
705 struct commit_list *reversed = NULL;
706 struct merge_options o;
3f9083cd 707 struct commit_list *j;
18668f53
MV
708
709 if (remoteheads->next) {
bacec478 710 error(_("Not handling anything other than two heads merge."));
18668f53
MV
711 return 2;
712 }
713
714 init_merge_options(&o);
715 if (!strcmp(strategy, "subtree"))
85e51b78 716 o.subtree_shift = "";
8cc5b290 717
7610fa57 718 o.renormalize = option_renormalize;
99bfc669
JK
719 o.show_rename_progress =
720 show_progress == -1 ? isatty(2) : show_progress;
7610fa57 721
635a7bb1
JN
722 for (x = 0; x < xopts_nr; x++)
723 if (parse_merge_opt(&o, xopts[x]))
bacec478 724 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
18668f53
MV
725
726 o.branch1 = head_arg;
ae8e4c9c 727 o.branch2 = merge_remote_util(remoteheads->item)->name;
18668f53
MV
728
729 for (j = common; j; j = j->next)
730 commit_list_insert(j->item, &reversed);
731
732 index_fd = hold_locked_index(lock, 1);
894642f6 733 clean = merge_recursive(&o, head,
18668f53
MV
734 remoteheads->item, reversed, &result);
735 if (active_cache_changed &&
736 (write_cache(index_fd, active_cache, active_nr) ||
737 commit_locked_index(lock)))
bacec478 738 die (_("unable to write %s"), get_index_file());
42716660 739 rollback_lock_file(lock);
18668f53
MV
740 return clean ? 0 : 1;
741 } else {
67ac1e1d
JN
742 return try_merge_command(strategy, xopts_nr, xopts,
743 common, head_arg, remoteheads);
18668f53 744 }
1c7b76be
MV
745}
746
747static void count_diff_files(struct diff_queue_struct *q,
748 struct diff_options *opt, void *data)
749{
750 int *count = data;
751
752 (*count) += q->nr;
753}
754
755static int count_unmerged_entries(void)
756{
1c7b76be
MV
757 int i, ret = 0;
758
be6ff819
JH
759 for (i = 0; i < active_nr; i++)
760 if (ce_stage(active_cache[i]))
1c7b76be
MV
761 ret++;
762
763 return ret;
764}
765
cac42b26 766int checkout_fast_forward(const unsigned char *head, const unsigned char *remote)
1c7b76be
MV
767{
768 struct tree *trees[MAX_UNPACK_TREES];
769 struct unpack_trees_options opts;
770 struct tree_desc t[MAX_UNPACK_TREES];
771 int i, fd, nr_trees = 0;
772 struct dir_struct dir;
773 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
774
9ca8f607 775 refresh_cache(REFRESH_QUIET);
1c7b76be
MV
776
777 fd = hold_locked_index(lock_file, 1);
778
779 memset(&trees, 0, sizeof(trees));
780 memset(&opts, 0, sizeof(opts));
781 memset(&t, 0, sizeof(t));
c1d7036b
NTND
782 if (overwrite_ignore) {
783 memset(&dir, 0, sizeof(dir));
784 dir.flags |= DIR_SHOW_IGNORED;
785 setup_standard_excludes(&dir);
786 opts.dir = &dir;
787 }
1c7b76be
MV
788
789 opts.head_idx = 1;
790 opts.src_index = &the_index;
791 opts.dst_index = &the_index;
792 opts.update = 1;
793 opts.verbose_update = 1;
794 opts.merge = 1;
795 opts.fn = twoway_merge;
e294030f 796 setup_unpack_trees_porcelain(&opts, "merge");
1c7b76be
MV
797
798 trees[nr_trees] = parse_tree_indirect(head);
799 if (!trees[nr_trees++])
800 return -1;
801 trees[nr_trees] = parse_tree_indirect(remote);
802 if (!trees[nr_trees++])
803 return -1;
804 for (i = 0; i < nr_trees; i++) {
805 parse_tree(trees[i]);
806 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
807 }
808 if (unpack_trees(nr_trees, t, &opts))
809 return -1;
810 if (write_cache(fd, active_cache, active_nr) ||
811 commit_locked_index(lock_file))
bacec478 812 die(_("unable to write new index file"));
1c7b76be
MV
813 return 0;
814}
815
816static void split_merge_strategies(const char *string, struct strategy **list,
817 int *nr, int *alloc)
818{
819 char *p, *q, *buf;
820
821 if (!string)
822 return;
823
824 buf = xstrdup(string);
825 q = buf;
826 for (;;) {
827 p = strchr(q, ' ');
828 if (!p) {
829 ALLOC_GROW(*list, *nr + 1, *alloc);
830 (*list)[(*nr)++].name = xstrdup(q);
831 free(buf);
832 return;
833 } else {
834 *p = '\0';
835 ALLOC_GROW(*list, *nr + 1, *alloc);
836 (*list)[(*nr)++].name = xstrdup(q);
837 q = ++p;
838 }
839 }
840}
841
842static void add_strategies(const char *string, unsigned attr)
843{
844 struct strategy *list = NULL;
845 int list_alloc = 0, list_nr = 0, i;
846
847 memset(&list, 0, sizeof(list));
848 split_merge_strategies(string, &list, &list_nr, &list_alloc);
1719b5e4
MV
849 if (list) {
850 for (i = 0; i < list_nr; i++)
851 append_strategy(get_strategy(list[i].name));
1c7b76be
MV
852 return;
853 }
854 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
855 if (all_strategy[i].attr & attr)
856 append_strategy(&all_strategy[i]);
857
858}
859
66f4b98a 860static void write_merge_msg(struct strbuf *msg)
65969d43 861{
418c9b17
JN
862 const char *filename = git_path("MERGE_MSG");
863 int fd = open(filename, O_WRONLY | O_CREAT, 0666);
65969d43 864 if (fd < 0)
6c80cd29 865 die_errno(_("Could not open '%s' for writing"),
418c9b17 866 filename);
66f4b98a 867 if (write_in_full(fd, msg->buf, msg->len) != msg->len)
418c9b17 868 die_errno(_("Could not write to '%s'"), filename);
65969d43
JS
869 close(fd);
870}
871
66f4b98a 872static void read_merge_msg(struct strbuf *msg)
65969d43 873{
418c9b17 874 const char *filename = git_path("MERGE_MSG");
66f4b98a 875 strbuf_reset(msg);
418c9b17
JN
876 if (strbuf_read_file(msg, filename, 0) < 0)
877 die_errno(_("Could not read from '%s'"), filename);
65969d43
JS
878}
879
4c57bd27
JH
880static void write_merge_state(struct commit_list *);
881static void abort_commit(struct commit_list *remoteheads, const char *err_msg)
65969d43 882{
66f4b98a
JS
883 if (err_msg)
884 error("%s", err_msg);
885 fprintf(stderr,
886 _("Not committing merge; use 'git commit' to complete the merge.\n"));
4c57bd27 887 write_merge_state(remoteheads);
66f4b98a
JS
888 exit(1);
889}
890
f26af3fc
TR
891static const char merge_editor_comment[] =
892N_("Please enter a commit message to explain why this merge is necessary,\n"
893 "especially if it merges an updated upstream into a topic branch.\n"
894 "\n"
895 "Lines starting with '#' will be ignored, and an empty message aborts\n"
896 "the commit.\n");
897
4c57bd27 898static void prepare_to_commit(struct commit_list *remoteheads)
66f4b98a
JS
899{
900 struct strbuf msg = STRBUF_INIT;
f26af3fc 901 const char *comment = _(merge_editor_comment);
66f4b98a
JS
902 strbuf_addbuf(&msg, &merge_msg);
903 strbuf_addch(&msg, '\n');
f26af3fc
TR
904 if (0 < option_edit)
905 strbuf_add_lines(&msg, "# ", comment, strlen(comment));
66f4b98a 906 write_merge_msg(&msg);
65969d43
JS
907 run_hook(get_index_file(), "prepare-commit-msg",
908 git_path("MERGE_MSG"), "merge", NULL, NULL);
f8246281 909 if (0 < option_edit) {
66f4b98a 910 if (launch_editor(git_path("MERGE_MSG"), NULL, NULL))
4c57bd27 911 abort_commit(remoteheads, NULL);
66f4b98a
JS
912 }
913 read_merge_msg(&msg);
f8246281 914 stripspace(&msg, 0 < option_edit);
66f4b98a 915 if (!msg.len)
4c57bd27 916 abort_commit(remoteheads, _("Empty commit message."));
66f4b98a
JS
917 strbuf_release(&merge_msg);
918 strbuf_addbuf(&merge_msg, &msg);
919 strbuf_release(&msg);
65969d43
JS
920}
921
4c57bd27 922static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
1c7b76be
MV
923{
924 unsigned char result_tree[20], result_commit[20];
36e40535 925 struct commit_list *parent = xmalloc(sizeof(*parent));
1c7b76be
MV
926
927 write_tree_trivial(result_tree);
157efde1 928 printf(_("Wonderful.\n"));
894642f6 929 parent->item = head;
36e40535 930 parent->next = xmalloc(sizeof(*parent->next));
446247db
JH
931 parent->next->item = remoteheads->item;
932 parent->next->next = NULL;
4c57bd27 933 prepare_to_commit(remoteheads);
5de89d3a
JH
934 if (commit_tree(&merge_msg, result_tree, parent, result_commit, NULL,
935 sign_commit))
6b3c4c05 936 die(_("failed to write commit object"));
4c57bd27 937 finish(head, remoteheads, result_commit, "In-index merge");
1c7b76be
MV
938 drop_save();
939 return 0;
940}
941
894642f6 942static int finish_automerge(struct commit *head,
e78cbf8c 943 int head_subsumed,
894642f6 944 struct commit_list *common,
4c57bd27 945 struct commit_list *remoteheads,
1c7b76be
MV
946 unsigned char *result_tree,
947 const char *wt_strategy)
948{
e78cbf8c 949 struct commit_list *parents = NULL;
1c7b76be
MV
950 struct strbuf buf = STRBUF_INIT;
951 unsigned char result_commit[20];
952
953 free_commit_list(common);
e78cbf8c
JH
954 parents = remoteheads;
955 if (!head_subsumed || !allow_fast_forward)
894642f6 956 commit_list_insert(head, &parents);
1c7b76be 957 strbuf_addch(&merge_msg, '\n');
4c57bd27 958 prepare_to_commit(remoteheads);
5de89d3a
JH
959 if (commit_tree(&merge_msg, result_tree, parents, result_commit,
960 NULL, sign_commit))
6b3c4c05 961 die(_("failed to write commit object"));
f23101bf 962 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
4c57bd27 963 finish(head, remoteheads, result_commit, buf.buf);
1c7b76be
MV
964 strbuf_release(&buf);
965 drop_save();
966 return 0;
967}
968
7610fa57 969static int suggest_conflicts(int renormalizing)
1c7b76be 970{
418c9b17 971 const char *filename;
1c7b76be
MV
972 FILE *fp;
973 int pos;
974
418c9b17
JN
975 filename = git_path("MERGE_MSG");
976 fp = fopen(filename, "a");
1c7b76be 977 if (!fp)
418c9b17 978 die_errno(_("Could not open '%s' for writing"), filename);
1c7b76be
MV
979 fprintf(fp, "\nConflicts:\n");
980 for (pos = 0; pos < active_nr; pos++) {
981 struct cache_entry *ce = active_cache[pos];
982
983 if (ce_stage(ce)) {
984 fprintf(fp, "\t%s\n", ce->name);
985 while (pos + 1 < active_nr &&
986 !strcmp(ce->name,
987 active_cache[pos + 1]->name))
988 pos++;
989 }
990 }
991 fclose(fp);
cb6020bb 992 rerere(allow_rerere_auto);
bacec478
ÆAB
993 printf(_("Automatic merge failed; "
994 "fix conflicts and then commit the result.\n"));
1c7b76be
MV
995 return 1;
996}
997
894642f6
NTND
998static struct commit *is_old_style_invocation(int argc, const char **argv,
999 const unsigned char *head)
1c7b76be
MV
1000{
1001 struct commit *second_token = NULL;
76bf488e 1002 if (argc > 2) {
1c7b76be
MV
1003 unsigned char second_sha1[20];
1004
1005 if (get_sha1(argv[1], second_sha1))
1006 return NULL;
1007 second_token = lookup_commit_reference_gently(second_sha1, 0);
1008 if (!second_token)
bacec478 1009 die(_("'%s' is not a commit"), argv[1]);
1c7b76be
MV
1010 if (hashcmp(second_token->object.sha1, head))
1011 return NULL;
1012 }
1013 return second_token;
1014}
1015
1016static int evaluate_result(void)
1017{
1018 int cnt = 0;
1019 struct rev_info rev;
1020
1c7b76be
MV
1021 /* Check how many files differ. */
1022 init_revisions(&rev, "");
1023 setup_revisions(0, NULL, &rev, NULL);
1024 rev.diffopt.output_format |=
1025 DIFF_FORMAT_CALLBACK;
1026 rev.diffopt.format_callback = count_diff_files;
1027 rev.diffopt.format_callback_data = &cnt;
1028 run_diff_files(&rev, 0);
1029
1030 /*
1031 * Check how many unmerged entries are
1032 * there.
1033 */
1034 cnt += count_unmerged_entries();
1035
1036 return cnt;
1037}
1038
93e535a5
JH
1039/*
1040 * Pretend as if the user told us to merge with the tracking
1041 * branch we have for the upstream of the current branch
1042 */
1043static int setup_with_upstream(const char ***argv)
1044{
1045 struct branch *branch = branch_get(NULL);
1046 int i;
1047 const char **args;
1048
1049 if (!branch)
c7f426d4 1050 die(_("No current branch."));
93e535a5 1051 if (!branch->remote)
c7f426d4 1052 die(_("No remote for the current branch."));
93e535a5 1053 if (!branch->merge_nr)
c7f426d4 1054 die(_("No default upstream defined for the current branch."));
93e535a5
JH
1055
1056 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
1057 for (i = 0; i < branch->merge_nr; i++) {
1058 if (!branch->merge[i]->dst)
c7f426d4 1059 die(_("No remote tracking branch for %s from %s"),
93e535a5
JH
1060 branch->merge[i]->src, branch->remote_name);
1061 args[i] = branch->merge[i]->dst;
1062 }
1063 args[i] = NULL;
1064 *argv = args;
1065 return i;
1066}
1067
4c57bd27 1068static void write_merge_state(struct commit_list *remoteheads)
66f4b98a 1069{
418c9b17 1070 const char *filename;
66f4b98a
JS
1071 int fd;
1072 struct commit_list *j;
1073 struct strbuf buf = STRBUF_INIT;
1074
274a5c06
JH
1075 for (j = remoteheads; j; j = j->next) {
1076 unsigned const char *sha1;
1077 struct commit *c = j->item;
1078 if (c->util && merge_remote_util(c)->obj) {
1079 sha1 = merge_remote_util(c)->obj->sha1;
1080 } else {
1081 sha1 = c->object.sha1;
1082 }
1083 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
1084 }
418c9b17
JN
1085 filename = git_path("MERGE_HEAD");
1086 fd = open(filename, O_WRONLY | O_CREAT, 0666);
66f4b98a 1087 if (fd < 0)
418c9b17 1088 die_errno(_("Could not open '%s' for writing"), filename);
66f4b98a 1089 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
418c9b17 1090 die_errno(_("Could not write to '%s'"), filename);
66f4b98a
JS
1091 close(fd);
1092 strbuf_addch(&merge_msg, '\n');
1093 write_merge_msg(&merge_msg);
418c9b17
JN
1094
1095 filename = git_path("MERGE_MODE");
1096 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
66f4b98a 1097 if (fd < 0)
418c9b17 1098 die_errno(_("Could not open '%s' for writing"), filename);
66f4b98a
JS
1099 strbuf_reset(&buf);
1100 if (!allow_fast_forward)
1101 strbuf_addf(&buf, "no-ff");
1102 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
418c9b17 1103 die_errno(_("Could not write to '%s'"), filename);
66f4b98a
JS
1104 close(fd);
1105}
1106
f8246281
JH
1107static int default_edit_option(void)
1108{
1109 static const char name[] = "GIT_MERGE_AUTOEDIT";
1110 const char *e = getenv(name);
1111 struct stat st_stdin, st_stdout;
1112
1113 if (have_message)
1114 /* an explicit -m msg without --[no-]edit */
1115 return 0;
1116
1117 if (e) {
1118 int v = git_config_maybe_bool(name, e);
1119 if (v < 0)
1120 die("Bad value '%s' in environment '%s'", e, name);
1121 return v;
1122 }
1123
1124 /* Use editor if stdin and stdout are the same and is a tty */
1125 return (!fstat(0, &st_stdin) &&
1126 !fstat(1, &st_stdout) &&
d46f476c 1127 isatty(0) && isatty(1) &&
f8246281
JH
1128 st_stdin.st_dev == st_stdout.st_dev &&
1129 st_stdin.st_ino == st_stdout.st_ino &&
1130 st_stdin.st_mode == st_stdout.st_mode);
1131}
1132
e78cbf8c
JH
1133static struct commit_list *collect_parents(struct commit *head_commit,
1134 int *head_subsumed,
1135 int argc, const char **argv)
b5d887f9
JH
1136{
1137 int i;
e78cbf8c 1138 struct commit_list *remoteheads = NULL, *parents, *next;
b5d887f9
JH
1139 struct commit_list **remotes = &remoteheads;
1140
e78cbf8c
JH
1141 if (head_commit)
1142 remotes = &commit_list_insert(head_commit, remotes)->next;
b5d887f9
JH
1143 for (i = 0; i < argc; i++) {
1144 struct commit *commit = get_merge_parent(argv[i]);
1145 if (!commit)
1146 die(_("%s - not something we can merge"), argv[i]);
1147 remotes = &commit_list_insert(commit, remotes)->next;
1148 }
1149 *remotes = NULL;
e78cbf8c
JH
1150
1151 parents = reduce_heads(remoteheads);
1152
1153 *head_subsumed = 1; /* we will flip this to 0 when we find it */
1154 for (remoteheads = NULL, remotes = &remoteheads;
1155 parents;
1156 parents = next) {
1157 struct commit *commit = parents->item;
1158 next = parents->next;
1159 if (commit == head_commit)
1160 *head_subsumed = 0;
1161 else
1162 remotes = &commit_list_insert(commit, remotes)->next;
1163 }
b5d887f9
JH
1164 return remoteheads;
1165}
f8246281 1166
1c7b76be
MV
1167int cmd_merge(int argc, const char **argv, const char *prefix)
1168{
1169 unsigned char result_tree[20];
b4fd9406 1170 unsigned char stash[20];
894642f6
NTND
1171 unsigned char head_sha1[20];
1172 struct commit *head_commit;
f285a2d7 1173 struct strbuf buf = STRBUF_INIT;
1c7b76be 1174 const char *head_arg;
e78cbf8c 1175 int flag, i, ret = 0, head_subsumed;
1c7b76be
MV
1176 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1177 struct commit_list *common = NULL;
1178 const char *best_strategy = NULL, *wt_strategy = NULL;
b5d887f9 1179 struct commit_list *remoteheads, *p;
96ec7b1e 1180 void *branch_to_free;
1c7b76be 1181
da53eec6
NTND
1182 if (argc == 2 && !strcmp(argv[1], "-h"))
1183 usage_with_options(builtin_merge_usage, builtin_merge_options);
1c7b76be
MV
1184
1185 /*
1186 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1187 * current branch.
1188 */
96ec7b1e
NTND
1189 branch = branch_to_free = resolve_refdup("HEAD", head_sha1, 0, &flag);
1190 if (branch && !prefixcmp(branch, "refs/heads/"))
1191 branch += 11;
894642f6
NTND
1192 if (!branch || is_null_sha1(head_sha1))
1193 head_commit = NULL;
baf18fc2
NTND
1194 else
1195 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1c7b76be
MV
1196
1197 git_config(git_merge_config, NULL);
1198
0d8fc3ef
JH
1199 if (branch_mergeoptions)
1200 parse_branch_merge_options(branch_mergeoptions);
37782920 1201 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1c7b76be 1202 builtin_merge_usage, 0);
898eacd8
JH
1203 if (shortlog_len < 0)
1204 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
2a22c1b3 1205
99bfc669
JK
1206 if (verbosity < 0 && show_progress == -1)
1207 show_progress = 0;
1208
35d2fffd
JH
1209 if (abort_current_merge) {
1210 int nargc = 2;
1211 const char *nargv[] = {"reset", "--merge", NULL};
1212
1213 if (!file_exists(git_path("MERGE_HEAD")))
bacec478 1214 die(_("There is no merge to abort (MERGE_HEAD missing)."));
35d2fffd
JH
1215
1216 /* Invoke 'git reset --merge' */
d5a35c11
NTND
1217 ret = cmd_reset(nargc, nargv, prefix);
1218 goto done;
35d2fffd
JH
1219 }
1220
2a22c1b3
JH
1221 if (read_cache_unmerged())
1222 die_resolve_conflict("merge");
1223
1224 if (file_exists(git_path("MERGE_HEAD"))) {
1225 /*
1226 * There is no unmerged entry, don't advise 'git
1227 * add/rm <file>', just 'git commit'.
1228 */
1229 if (advice_resolve_conflict)
bacec478
ÆAB
1230 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1231 "Please, commit your changes before you can merge."));
2a22c1b3 1232 else
bacec478 1233 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
2a22c1b3 1234 }
d7e5c0cb
JS
1235 if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
1236 if (advice_resolve_conflict)
f68f1801
ÆAB
1237 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1238 "Please, commit your changes before you can merge."));
d7e5c0cb 1239 else
f68f1801 1240 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
2a22c1b3
JH
1241 }
1242 resolve_undo_clear();
1243
7f87aff2
TA
1244 if (verbosity < 0)
1245 show_diffstat = 0;
1c7b76be
MV
1246
1247 if (squash) {
1248 if (!allow_fast_forward)
bacec478 1249 die(_("You cannot combine --squash with --no-ff."));
1c7b76be
MV
1250 option_commit = 0;
1251 }
1252
13474835 1253 if (!allow_fast_forward && fast_forward_only)
bacec478 1254 die(_("You cannot combine --no-ff with --ff-only."));
13474835 1255
4e8115ff 1256 if (!abort_current_merge) {
5480207c
VR
1257 if (!argc) {
1258 if (default_to_upstream)
1259 argc = setup_with_upstream(&argv);
1260 else
1261 die(_("No commit specified and merge.defaultToUpstream not set."));
1262 } else if (argc == 1 && !strcmp(argv[0], "-"))
4e8115ff
JH
1263 argv[0] = "@{-1}";
1264 }
1c7b76be
MV
1265 if (!argc)
1266 usage_with_options(builtin_merge_usage,
1267 builtin_merge_options);
1268
1269 /*
1270 * This could be traditional "merge <msg> HEAD <commit>..." and
1271 * the way we can tell it is to see if the second token is HEAD,
1272 * but some people might have misused the interface and used a
1273 * committish that is the same as HEAD there instead.
1274 * Traditional format never would have "-m" so it is an
1275 * additional safety measure to check for it.
1276 */
1c7b76be 1277
894642f6
NTND
1278 if (!have_message && head_commit &&
1279 is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
1c7b76be
MV
1280 strbuf_addstr(&merge_msg, argv[0]);
1281 head_arg = argv[1];
1282 argv += 2;
1283 argc -= 2;
e78cbf8c 1284 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
894642f6 1285 } else if (!head_commit) {
ae8e4c9c 1286 struct commit *remote_head;
1c7b76be
MV
1287 /*
1288 * If the merged head is a valid one there is no reason
1289 * to forbid "git merge" into a branch yet to be born.
1290 * We do the same for "git pull".
1291 */
1292 if (argc != 1)
bacec478
ÆAB
1293 die(_("Can merge only exactly one commit into "
1294 "empty head"));
4be636f4 1295 if (squash)
bacec478 1296 die(_("Squash commit into empty head not supported yet"));
4be636f4 1297 if (!allow_fast_forward)
bacec478
ÆAB
1298 die(_("Non-fast-forward commit does not make sense into "
1299 "an empty head"));
e78cbf8c 1300 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
b5d887f9 1301 remote_head = remoteheads->item;
1c7b76be 1302 if (!remote_head)
bacec478 1303 die(_("%s - not something we can merge"), argv[0]);
ae8e4c9c
JH
1304 read_empty(remote_head->object.sha1, 0);
1305 update_ref("initial pull", "HEAD", remote_head->object.sha1,
1306 NULL, 0, DIE_ON_ERR);
d5a35c11 1307 goto done;
1c7b76be 1308 } else {
97d45bcb 1309 struct strbuf merge_names = STRBUF_INIT;
1c7b76be
MV
1310
1311 /* We are invoked directly as the first-class UI. */
1312 head_arg = "HEAD";
1313
1314 /*
ae8e4c9c
JH
1315 * All the rest are the commits being merged; prepare
1316 * the standard merge summary message to be appended
1317 * to the given message.
1c7b76be 1318 */
e78cbf8c 1319 remoteheads = collect_parents(head_commit, &head_subsumed, argc, argv);
b5d887f9
JH
1320 for (p = remoteheads; p; p = p->next)
1321 merge_name(merge_remote_util(p->item)->name, &merge_names);
f0ecac2b 1322
96e9420c 1323 if (!have_message || shortlog_len) {
cbda121c
JH
1324 struct fmt_merge_msg_opts opts;
1325 memset(&opts, 0, sizeof(opts));
1326 opts.add_title = !have_message;
1327 opts.shortlog_len = shortlog_len;
1328
1329 fmt_merge_msg(&merge_names, &merge_msg, &opts);
1876166a
RR
1330 if (merge_msg.len)
1331 strbuf_setlen(&merge_msg, merge_msg.len - 1);
1332 }
1c7b76be
MV
1333 }
1334
894642f6 1335 if (!head_commit || !argc)
1c7b76be
MV
1336 usage_with_options(builtin_merge_usage,
1337 builtin_merge_options);
1338
1339 strbuf_addstr(&buf, "merge");
b5d887f9
JH
1340 for (p = remoteheads; p; p = p->next)
1341 strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
1c7b76be
MV
1342 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1343 strbuf_reset(&buf);
1344
b5d887f9
JH
1345 for (p = remoteheads; p; p = p->next) {
1346 struct commit *commit = p->item;
ae8e4c9c
JH
1347 strbuf_addf(&buf, "GITHEAD_%s",
1348 sha1_to_hex(commit->object.sha1));
b5d887f9 1349 setenv(buf.buf, merge_remote_util(commit)->name, 1);
1c7b76be 1350 strbuf_reset(&buf);
b5c9f1c1
JH
1351 if (!fast_forward_only &&
1352 merge_remote_util(commit) &&
fab47d05 1353 merge_remote_util(commit)->obj &&
d82829b6 1354 merge_remote_util(commit)->obj->type == OBJ_TAG)
fab47d05 1355 allow_fast_forward = 0;
1c7b76be
MV
1356 }
1357
f8246281
JH
1358 if (option_edit < 0)
1359 option_edit = default_edit_option();
1360
1c7b76be 1361 if (!use_strategies) {
e78cbf8c
JH
1362 if (!remoteheads)
1363 ; /* already up-to-date */
1364 else if (!remoteheads->next)
1c7b76be
MV
1365 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1366 else
1367 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1368 }
1369
1370 for (i = 0; i < use_strategies_nr; i++) {
1371 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1372 allow_fast_forward = 0;
1373 if (use_strategies[i]->attr & NO_TRIVIAL)
1374 allow_trivial = 0;
1375 }
1376
e78cbf8c
JH
1377 if (!remoteheads)
1378 ; /* already up-to-date */
1379 else if (!remoteheads->next)
894642f6 1380 common = get_merge_bases(head_commit, remoteheads->item, 1);
1c7b76be
MV
1381 else {
1382 struct commit_list *list = remoteheads;
894642f6 1383 commit_list_insert(head_commit, &list);
1c7b76be
MV
1384 common = get_octopus_merge_bases(list);
1385 free(list);
1386 }
1387
894642f6
NTND
1388 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
1389 NULL, 0, DIE_ON_ERR);
1c7b76be 1390
e78cbf8c 1391 if (remoteheads && !common)
1c7b76be 1392 ; /* No common ancestors found. We need a real merge. */
e78cbf8c
JH
1393 else if (!remoteheads ||
1394 (!remoteheads->next && !common->next &&
1395 common->item == remoteheads->item)) {
1c7b76be
MV
1396 /*
1397 * If head can reach all the merge then we are up to date.
1398 * but first the most common case of merging one remote.
1399 */
1400 finish_up_to_date("Already up-to-date.");
d5a35c11 1401 goto done;
1c7b76be
MV
1402 } else if (allow_fast_forward && !remoteheads->next &&
1403 !common->next &&
894642f6 1404 !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
1c7b76be 1405 /* Again the most common case of merging one remote. */
f285a2d7 1406 struct strbuf msg = STRBUF_INIT;
ae8e4c9c 1407 struct commit *commit;
1c7b76be
MV
1408 char hex[41];
1409
894642f6 1410 strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
1c7b76be 1411
7f87aff2 1412 if (verbosity >= 0)
2ceb61e0 1413 printf(_("Updating %s..%s\n"),
7f87aff2
TA
1414 hex,
1415 find_unique_abbrev(remoteheads->item->object.sha1,
1416 DEFAULT_ABBREV));
a75d7b54 1417 strbuf_addstr(&msg, "Fast-forward");
1c7b76be
MV
1418 if (have_message)
1419 strbuf_addstr(&msg,
1420 " (no commit created; -m option ignored)");
ae8e4c9c 1421 commit = remoteheads->item;
b7f7c079 1422 if (!commit) {
d5a35c11
NTND
1423 ret = 1;
1424 goto done;
1425 }
1c7b76be 1426
ae8e4c9c 1427 if (checkout_fast_forward(head_commit->object.sha1,
b7f7c079 1428 commit->object.sha1)) {
d5a35c11
NTND
1429 ret = 1;
1430 goto done;
1431 }
1c7b76be 1432
4c57bd27 1433 finish(head_commit, remoteheads, commit->object.sha1, msg.buf);
1c7b76be 1434 drop_save();
d5a35c11 1435 goto done;
1c7b76be
MV
1436 } else if (!remoteheads->next && common->next)
1437 ;
1438 /*
a75d7b54 1439 * We are not doing octopus and not fast-forward. Need
1c7b76be
MV
1440 * a real merge.
1441 */
1442 else if (!remoteheads->next && !common->next && option_commit) {
1443 /*
a75d7b54 1444 * We are not doing octopus, not fast-forward, and have
1c7b76be
MV
1445 * only one common.
1446 */
1447 refresh_cache(REFRESH_QUIET);
13474835 1448 if (allow_trivial && !fast_forward_only) {
1c7b76be 1449 /* See if it is really trivial. */
f9bc573f 1450 git_committer_info(IDENT_STRICT);
bacec478 1451 printf(_("Trying really trivial in-index merge...\n"));
1c7b76be 1452 if (!read_tree_trivial(common->item->object.sha1,
d5a35c11
NTND
1453 head_commit->object.sha1,
1454 remoteheads->item->object.sha1)) {
4c57bd27 1455 ret = merge_trivial(head_commit, remoteheads);
d5a35c11
NTND
1456 goto done;
1457 }
bacec478 1458 printf(_("Nope.\n"));
1c7b76be
MV
1459 }
1460 } else {
1461 /*
1462 * An octopus. If we can reach all the remote we are up
1463 * to date.
1464 */
1465 int up_to_date = 1;
1466 struct commit_list *j;
1467
1468 for (j = remoteheads; j; j = j->next) {
1469 struct commit_list *common_one;
1470
1471 /*
1472 * Here we *have* to calculate the individual
1473 * merge_bases again, otherwise "git merge HEAD^
1474 * HEAD^^" would be missed.
1475 */
894642f6 1476 common_one = get_merge_bases(head_commit, j->item, 1);
1c7b76be
MV
1477 if (hashcmp(common_one->item->object.sha1,
1478 j->item->object.sha1)) {
1479 up_to_date = 0;
1480 break;
1481 }
1482 }
1483 if (up_to_date) {
1484 finish_up_to_date("Already up-to-date. Yeeah!");
d5a35c11 1485 goto done;
1c7b76be
MV
1486 }
1487 }
1488
13474835 1489 if (fast_forward_only)
bacec478 1490 die(_("Not possible to fast-forward, aborting."));
13474835 1491
1c7b76be 1492 /* We are going to make a new commit. */
f9bc573f 1493 git_committer_info(IDENT_STRICT);
1c7b76be
MV
1494
1495 /*
1496 * At this point, we need a real merge. No matter what strategy
1497 * we use, it would operate on the index, possibly affecting the
1498 * working tree, and when resolved cleanly, have the desired
1499 * tree in the index -- this means that the index must be in
1500 * sync with the head commit. The strategies are responsible
1501 * to ensure this.
1502 */
b4fd9406
NTND
1503 if (use_strategies_nr == 1 ||
1504 /*
1505 * Stash away the local changes so that we can try more than one.
1506 */
1507 save_state(stash))
1508 hashcpy(stash, null_sha1);
1c7b76be
MV
1509
1510 for (i = 0; i < use_strategies_nr; i++) {
1511 int ret;
1512 if (i) {
bacec478 1513 printf(_("Rewinding the tree to pristine...\n"));
894642f6 1514 restore_state(head_commit->object.sha1, stash);
1c7b76be
MV
1515 }
1516 if (use_strategies_nr != 1)
bacec478 1517 printf(_("Trying merge strategy %s...\n"),
1c7b76be
MV
1518 use_strategies[i]->name);
1519 /*
1520 * Remember which strategy left the state in the working
1521 * tree.
1522 */
1523 wt_strategy = use_strategies[i]->name;
1524
1525 ret = try_merge_strategy(use_strategies[i]->name,
4c57bd27
JH
1526 common, remoteheads,
1527 head_commit, head_arg);
1c7b76be
MV
1528 if (!option_commit && !ret) {
1529 merge_was_ok = 1;
1530 /*
1531 * This is necessary here just to avoid writing
1532 * the tree, but later we will *not* exit with
1533 * status code 1 because merge_was_ok is set.
1534 */
1535 ret = 1;
1536 }
1537
1538 if (ret) {
1539 /*
1540 * The backend exits with 1 when conflicts are
1541 * left to be resolved, with 2 when it does not
1542 * handle the given merge at all.
1543 */
1544 if (ret == 1) {
1545 int cnt = evaluate_result();
1546
1547 if (best_cnt <= 0 || cnt <= best_cnt) {
1548 best_strategy = use_strategies[i]->name;
1549 best_cnt = cnt;
1550 }
1551 }
1552 if (merge_was_ok)
1553 break;
1554 else
1555 continue;
1556 }
1557
1558 /* Automerge succeeded. */
1559 write_tree_trivial(result_tree);
1560 automerge_was_ok = 1;
1561 break;
1562 }
1563
1564 /*
1565 * If we have a resulting tree, that means the strategy module
1566 * auto resolved the merge cleanly.
1567 */
d5a35c11 1568 if (automerge_was_ok) {
e78cbf8c
JH
1569 ret = finish_automerge(head_commit, head_subsumed,
1570 common, remoteheads,
4c57bd27 1571 result_tree, wt_strategy);
d5a35c11
NTND
1572 goto done;
1573 }
1c7b76be
MV
1574
1575 /*
1576 * Pick the result from the best strategy and have the user fix
1577 * it up.
1578 */
1579 if (!best_strategy) {
894642f6 1580 restore_state(head_commit->object.sha1, stash);
1c7b76be
MV
1581 if (use_strategies_nr > 1)
1582 fprintf(stderr,
bacec478 1583 _("No merge strategy handled the merge.\n"));
1c7b76be 1584 else
bacec478 1585 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1c7b76be 1586 use_strategies[0]->name);
d5a35c11
NTND
1587 ret = 2;
1588 goto done;
1c7b76be
MV
1589 } else if (best_strategy == wt_strategy)
1590 ; /* We already have its result in the working tree. */
1591 else {
bacec478 1592 printf(_("Rewinding the tree to pristine...\n"));
894642f6 1593 restore_state(head_commit->object.sha1, stash);
bacec478 1594 printf(_("Using the %s to prepare resolving by hand.\n"),
1c7b76be 1595 best_strategy);
4c57bd27
JH
1596 try_merge_strategy(best_strategy, common, remoteheads,
1597 head_commit, head_arg);
1c7b76be
MV
1598 }
1599
1600 if (squash)
4c57bd27 1601 finish(head_commit, remoteheads, NULL, NULL);
66f4b98a 1602 else
4c57bd27 1603 write_merge_state(remoteheads);
1c7b76be 1604
d5a35c11 1605 if (merge_was_ok)
bacec478
ÆAB
1606 fprintf(stderr, _("Automatic merge went well; "
1607 "stopped before committing as requested\n"));
d5a35c11
NTND
1608 else
1609 ret = suggest_conflicts(option_renormalize);
1610
1611done:
96ec7b1e 1612 free(branch_to_free);
d5a35c11 1613 return ret;
1c7b76be 1614}