diff: do not use null sha1 as a sentinel value
[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;
3adab6f3 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 55static struct commit_list *remoteheads;
1c7b76be
MV
56static struct strategy **use_strategies;
57static size_t use_strategies_nr, use_strategies_alloc;
8cc5b290
AP
58static const char **xopts;
59static size_t xopts_nr, xopts_alloc;
1c7b76be 60static const char *branch;
0d8fc3ef 61static char *branch_mergeoptions;
7610fa57 62static int option_renormalize;
7f87aff2 63static int verbosity;
cb6020bb 64static int allow_rerere_auto;
35d2fffd 65static int abort_current_merge;
99bfc669 66static int show_progress = -1;
93e535a5 67static int default_to_upstream;
ba3c69a9 68static const char *sign_commit;
1c7b76be
MV
69
70static struct strategy all_strategy[] = {
1c7b76be
MV
71 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
72 { "octopus", DEFAULT_OCTOPUS },
73 { "resolve", 0 },
1c7b76be
MV
74 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
75 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
76};
77
78static const char *pull_twohead, *pull_octopus;
79
80static int option_parse_message(const struct option *opt,
81 const char *arg, int unset)
82{
83 struct strbuf *buf = opt->value;
84
85 if (unset)
86 strbuf_setlen(buf, 0);
74f5b7fb 87 else if (arg) {
ce9d823b 88 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
1c7b76be 89 have_message = 1;
74f5b7fb 90 } else
bacec478 91 return error(_("switch `m' requires a value"));
1c7b76be
MV
92 return 0;
93}
94
95static struct strategy *get_strategy(const char *name)
96{
97 int i;
87091b49
MV
98 struct strategy *ret;
99 static struct cmdnames main_cmds, other_cmds;
e321180e 100 static int loaded;
1c7b76be
MV
101
102 if (!name)
103 return NULL;
104
105 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
106 if (!strcmp(name, all_strategy[i].name))
107 return &all_strategy[i];
1719b5e4 108
e321180e 109 if (!loaded) {
87091b49 110 struct cmdnames not_strategies;
e321180e 111 loaded = 1;
87091b49 112
87091b49 113 memset(&not_strategies, 0, sizeof(struct cmdnames));
e321180e 114 load_command_list("git-merge-", &main_cmds, &other_cmds);
87091b49
MV
115 for (i = 0; i < main_cmds.cnt; i++) {
116 int j, found = 0;
117 struct cmdname *ent = main_cmds.names[i];
118 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
119 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
120 && !all_strategy[j].name[ent->len])
121 found = 1;
122 if (!found)
123 add_cmdname(&not_strategies, ent->name, ent->len);
87091b49 124 }
ed874656 125 exclude_cmds(&main_cmds, &not_strategies);
87091b49
MV
126 }
127 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
bacec478
ÆAB
128 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
129 fprintf(stderr, _("Available strategies are:"));
131f9a10
JH
130 for (i = 0; i < main_cmds.cnt; i++)
131 fprintf(stderr, " %s", main_cmds.names[i]->name);
132 fprintf(stderr, ".\n");
133 if (other_cmds.cnt) {
bacec478 134 fprintf(stderr, _("Available custom strategies are:"));
131f9a10
JH
135 for (i = 0; i < other_cmds.cnt; i++)
136 fprintf(stderr, " %s", other_cmds.names[i]->name);
137 fprintf(stderr, ".\n");
138 }
87091b49
MV
139 exit(1);
140 }
141
19d4b416 142 ret = xcalloc(1, sizeof(struct strategy));
87091b49 143 ret->name = xstrdup(name);
52b48ef1 144 ret->attr = NO_TRIVIAL;
87091b49 145 return ret;
1c7b76be
MV
146}
147
148static void append_strategy(struct strategy *s)
149{
150 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
151 use_strategies[use_strategies_nr++] = s;
152}
153
154static int option_parse_strategy(const struct option *opt,
155 const char *name, int unset)
156{
1c7b76be
MV
157 if (unset)
158 return 0;
159
1719b5e4 160 append_strategy(get_strategy(name));
1c7b76be
MV
161 return 0;
162}
163
8cc5b290
AP
164static int option_parse_x(const struct option *opt,
165 const char *arg, int unset)
166{
167 if (unset)
168 return 0;
169
170 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
171 xopts[xopts_nr++] = xstrdup(arg);
172 return 0;
173}
174
1c7b76be
MV
175static int option_parse_n(const struct option *opt,
176 const char *arg, int unset)
177{
178 show_diffstat = unset;
179 return 0;
180}
181
182static struct option builtin_merge_options[] = {
183 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
184 "do not show a diffstat at the end of the merge",
185 PARSE_OPT_NOARG, option_parse_n },
186 OPT_BOOLEAN(0, "stat", &show_diffstat,
187 "show a diffstat at the end of the merge"),
188 OPT_BOOLEAN(0, "summary", &show_diffstat, "(synonym to --stat)"),
96e9420c
RR
189 { OPTION_INTEGER, 0, "log", &shortlog_len, "n",
190 "add (at most <n>) entries from shortlog to merge commit message",
191 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
1c7b76be
MV
192 OPT_BOOLEAN(0, "squash", &squash,
193 "create a single commit instead of doing a merge"),
194 OPT_BOOLEAN(0, "commit", &option_commit,
195 "perform a commit if the merge succeeds (default)"),
3adab6f3 196 OPT_BOOL('e', "edit", &option_edit,
66f4b98a 197 "edit message before committing"),
1c7b76be 198 OPT_BOOLEAN(0, "ff", &allow_fast_forward,
a75d7b54 199 "allow fast-forward (default)"),
13474835 200 OPT_BOOLEAN(0, "ff-only", &fast_forward_only,
4d8c3258 201 "abort if fast-forward is not possible"),
cb6020bb 202 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
1c7b76be
MV
203 OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
204 "merge strategy to use", option_parse_strategy),
8cc5b290
AP
205 OPT_CALLBACK('X', "strategy-option", &xopts, "option=value",
206 "option for selected merge strategy", option_parse_x),
23c6a803 207 OPT_CALLBACK('m', "message", &merge_msg, "message",
3f406175 208 "merge commit message (for a non-fast-forward merge)",
1c7b76be 209 option_parse_message),
7f87aff2 210 OPT__VERBOSITY(&verbosity),
35d2fffd
JH
211 OPT_BOOLEAN(0, "abort", &abort_current_merge,
212 "abort the current in-progress merge"),
99bfc669 213 OPT_SET_INT(0, "progress", &show_progress, "force progress reporting", 1),
ba3c69a9
JH
214 { OPTION_STRING, 'S', "gpg-sign", &sign_commit, "key id",
215 "GPG sign commit", PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
c1d7036b 216 OPT_BOOLEAN(0, "overwrite-ignore", &overwrite_ignore, "update ignored files (default)"),
1c7b76be
MV
217 OPT_END()
218};
219
220/* Cleans up metadata that is uninteresting after a succeeded merge. */
221static void drop_save(void)
222{
223 unlink(git_path("MERGE_HEAD"));
224 unlink(git_path("MERGE_MSG"));
cf10f9fd 225 unlink(git_path("MERGE_MODE"));
1c7b76be
MV
226}
227
b4fd9406 228static int save_state(unsigned char *stash)
1c7b76be
MV
229{
230 int len;
231 struct child_process cp;
232 struct strbuf buffer = STRBUF_INIT;
233 const char *argv[] = {"stash", "create", NULL};
234
235 memset(&cp, 0, sizeof(cp));
236 cp.argv = argv;
237 cp.out = -1;
238 cp.git_cmd = 1;
239
240 if (start_command(&cp))
bacec478 241 die(_("could not run stash."));
1c7b76be
MV
242 len = strbuf_read(&buffer, cp.out, 1024);
243 close(cp.out);
244
245 if (finish_command(&cp) || len < 0)
bacec478 246 die(_("stash failed"));
b4fd9406
NTND
247 else if (!len) /* no changes */
248 return -1;
1c7b76be
MV
249 strbuf_setlen(&buffer, buffer.len-1);
250 if (get_sha1(buffer.buf, stash))
bacec478 251 die(_("not a valid object: %s"), buffer.buf);
b4fd9406 252 return 0;
1c7b76be
MV
253}
254
172b6428
CB
255static void read_empty(unsigned const char *sha1, int verbose)
256{
257 int i = 0;
258 const char *args[7];
259
260 args[i++] = "read-tree";
261 if (verbose)
262 args[i++] = "-v";
263 args[i++] = "-m";
264 args[i++] = "-u";
265 args[i++] = EMPTY_TREE_SHA1_HEX;
266 args[i++] = sha1_to_hex(sha1);
267 args[i] = NULL;
268
269 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 270 die(_("read-tree failed"));
172b6428
CB
271}
272
1c7b76be
MV
273static void reset_hard(unsigned const char *sha1, int verbose)
274{
275 int i = 0;
276 const char *args[6];
277
278 args[i++] = "read-tree";
279 if (verbose)
280 args[i++] = "-v";
281 args[i++] = "--reset";
282 args[i++] = "-u";
283 args[i++] = sha1_to_hex(sha1);
284 args[i] = NULL;
285
286 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 287 die(_("read-tree failed"));
1c7b76be
MV
288}
289
894642f6
NTND
290static void restore_state(const unsigned char *head,
291 const unsigned char *stash)
1c7b76be 292{
f285a2d7 293 struct strbuf sb = STRBUF_INIT;
1c7b76be
MV
294 const char *args[] = { "stash", "apply", NULL, NULL };
295
296 if (is_null_sha1(stash))
297 return;
298
299 reset_hard(head, 1);
300
1c7b76be
MV
301 args[2] = sha1_to_hex(stash);
302
303 /*
304 * It is OK to ignore error here, for example when there was
305 * nothing to restore.
306 */
307 run_command_v_opt(args, RUN_GIT_CMD);
308
309 strbuf_release(&sb);
310 refresh_cache(REFRESH_QUIET);
311}
312
313/* This is called when no merge was necessary. */
314static void finish_up_to_date(const char *msg)
315{
7f87aff2 316 if (verbosity >= 0)
bacec478 317 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
1c7b76be
MV
318 drop_save();
319}
320
894642f6 321static void squash_message(struct commit *commit)
1c7b76be
MV
322{
323 struct rev_info rev;
f285a2d7 324 struct strbuf out = STRBUF_INIT;
1c7b76be 325 struct commit_list *j;
418c9b17 326 const char *filename;
1c7b76be 327 int fd;
dd2e794a 328 struct pretty_print_context ctx = {0};
1c7b76be 329
bacec478 330 printf(_("Squash commit -- not updating HEAD\n"));
418c9b17
JN
331 filename = git_path("SQUASH_MSG");
332 fd = open(filename, O_WRONLY | O_CREAT, 0666);
1c7b76be 333 if (fd < 0)
418c9b17 334 die_errno(_("Could not write to '%s'"), filename);
1c7b76be
MV
335
336 init_revisions(&rev, NULL);
337 rev.ignore_merges = 1;
338 rev.commit_format = CMIT_FMT_MEDIUM;
339
1c7b76be
MV
340 commit->object.flags |= UNINTERESTING;
341 add_pending_object(&rev, &commit->object, NULL);
342
343 for (j = remoteheads; j; j = j->next)
344 add_pending_object(&rev, &j->item->object, NULL);
345
346 setup_revisions(0, NULL, &rev, NULL);
347 if (prepare_revision_walk(&rev))
bacec478 348 die(_("revision walk setup failed"));
1c7b76be 349
dd2e794a
TR
350 ctx.abbrev = rev.abbrev;
351 ctx.date_mode = rev.date_mode;
6bf13944 352 ctx.fmt = rev.commit_format;
dd2e794a 353
1c7b76be
MV
354 strbuf_addstr(&out, "Squashed commit of the following:\n");
355 while ((commit = get_revision(&rev)) != NULL) {
356 strbuf_addch(&out, '\n');
357 strbuf_addf(&out, "commit %s\n",
358 sha1_to_hex(commit->object.sha1));
6bf13944 359 pretty_print_commit(&ctx, commit, &out);
1c7b76be 360 }
47d32af2 361 if (write(fd, out.buf, out.len) < 0)
bacec478 362 die_errno(_("Writing SQUASH_MSG"));
47d32af2 363 if (close(fd))
bacec478 364 die_errno(_("Finishing SQUASH_MSG"));
1c7b76be
MV
365 strbuf_release(&out);
366}
367
894642f6
NTND
368static void finish(struct commit *head_commit,
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) {
894642f6 383 squash_message(head_commit);
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);
402 opts.output_format |=
403 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
404 opts.detect_rename = DIFF_DETECT_RENAME;
1c7b76be 405 if (diff_setup_done(&opts) < 0)
bacec478 406 die(_("diff_setup_done failed"));
1c7b76be
MV
407 diff_tree_sha1(head, new_head, "", &opts);
408 diffcore_std(&opts);
409 diff_flush(&opts);
410 }
411
412 /* Run a post-merge hook */
ae98a008 413 run_hook(NULL, "post-merge", squash ? "1" : "0", NULL);
1c7b76be
MV
414
415 strbuf_release(&reflog_message);
416}
417
418/* Get the name for the merge commit's message. */
419static void merge_name(const char *remote, struct strbuf *msg)
420{
ae8e4c9c 421 struct commit *remote_head;
c6893323 422 unsigned char branch_head[20];
f285a2d7 423 struct strbuf buf = STRBUF_INIT;
c9717ee9 424 struct strbuf bname = STRBUF_INIT;
1c7b76be 425 const char *ptr;
751c5974 426 char *found_ref;
1c7b76be
MV
427 int len, early;
428
a552de75
JH
429 strbuf_branchname(&bname, remote);
430 remote = bname.buf;
c9717ee9 431
1c7b76be 432 memset(branch_head, 0, sizeof(branch_head));
ae8e4c9c 433 remote_head = get_merge_parent(remote);
1c7b76be 434 if (!remote_head)
bacec478 435 die(_("'%s' does not point to a commit"), remote);
1c7b76be 436
751c5974
JK
437 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
438 if (!prefixcmp(found_ref, "refs/heads/")) {
439 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
440 sha1_to_hex(branch_head), remote);
441 goto cleanup;
442 }
57b58db7
JH
443 if (!prefixcmp(found_ref, "refs/tags/")) {
444 strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
445 sha1_to_hex(branch_head), remote);
446 goto cleanup;
447 }
69a8b7c7 448 if (!prefixcmp(found_ref, "refs/remotes/")) {
13931236 449 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
69a8b7c7
JK
450 sha1_to_hex(branch_head), remote);
451 goto cleanup;
452 }
1c7b76be
MV
453 }
454
455 /* See if remote matches <name>^^^.. or <name>~<number> */
456 for (len = 0, ptr = remote + strlen(remote);
457 remote < ptr && ptr[-1] == '^';
458 ptr--)
459 len++;
460 if (len)
461 early = 1;
462 else {
463 early = 0;
464 ptr = strrchr(remote, '~');
465 if (ptr) {
466 int seen_nonzero = 0;
467
468 len++; /* count ~ */
469 while (*++ptr && isdigit(*ptr)) {
470 seen_nonzero |= (*ptr != '0');
471 len++;
472 }
473 if (*ptr)
474 len = 0; /* not ...~<number> */
475 else if (seen_nonzero)
476 early = 1;
477 else if (len == 1)
478 early = 1; /* "name~" is "name~1"! */
479 }
480 }
481 if (len) {
482 struct strbuf truname = STRBUF_INIT;
483 strbuf_addstr(&truname, "refs/heads/");
484 strbuf_addstr(&truname, remote);
9b6bf4d5 485 strbuf_setlen(&truname, truname.len - len);
c6893323 486 if (ref_exists(truname.buf)) {
1c7b76be
MV
487 strbuf_addf(msg,
488 "%s\t\tbranch '%s'%s of .\n",
ae8e4c9c 489 sha1_to_hex(remote_head->object.sha1),
9b6bf4d5 490 truname.buf + 11,
1c7b76be 491 (early ? " (early part)" : ""));
c9717ee9
JH
492 strbuf_release(&truname);
493 goto cleanup;
1c7b76be
MV
494 }
495 }
496
497 if (!strcmp(remote, "FETCH_HEAD") &&
498 !access(git_path("FETCH_HEAD"), R_OK)) {
418c9b17 499 const char *filename;
1c7b76be 500 FILE *fp;
f285a2d7 501 struct strbuf line = STRBUF_INIT;
1c7b76be
MV
502 char *ptr;
503
418c9b17
JN
504 filename = git_path("FETCH_HEAD");
505 fp = fopen(filename, "r");
1c7b76be 506 if (!fp)
bacec478 507 die_errno(_("could not open '%s' for reading"),
418c9b17 508 filename);
1c7b76be
MV
509 strbuf_getline(&line, fp, '\n');
510 fclose(fp);
511 ptr = strstr(line.buf, "\tnot-for-merge\t");
512 if (ptr)
513 strbuf_remove(&line, ptr-line.buf+1, 13);
514 strbuf_addbuf(msg, &line);
515 strbuf_release(&line);
c9717ee9 516 goto cleanup;
1c7b76be
MV
517 }
518 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
ae8e4c9c 519 sha1_to_hex(remote_head->object.sha1), remote);
c9717ee9
JH
520cleanup:
521 strbuf_release(&buf);
522 strbuf_release(&bname);
1c7b76be
MV
523}
524
0d8fc3ef
JH
525static void parse_branch_merge_options(char *bmo)
526{
527 const char **argv;
528 int argc;
529
530 if (!bmo)
531 return;
532 argc = split_cmdline(bmo, &argv);
533 if (argc < 0)
c7fe5b61
JH
534 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
535 split_cmdline_strerror(argc));
0d8fc3ef
JH
536 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
537 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
538 argc++;
539 argv[0] = "branch.*.mergeoptions";
540 parse_options(argc, argv, NULL, builtin_merge_options,
541 builtin_merge_usage, 0);
542 free(argv);
543}
544
186458b1 545static int git_merge_config(const char *k, const char *v, void *cb)
1c7b76be 546{
898eacd8
JH
547 int status;
548
1c7b76be
MV
549 if (branch && !prefixcmp(k, "branch.") &&
550 !prefixcmp(k + 7, branch) &&
551 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
0d8fc3ef
JH
552 free(branch_mergeoptions);
553 branch_mergeoptions = xstrdup(v);
554 return 0;
1c7b76be
MV
555 }
556
557 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
558 show_diffstat = git_config_bool(k, v);
559 else if (!strcmp(k, "pull.twohead"))
560 return git_config_string(&pull_twohead, k, v);
561 else if (!strcmp(k, "pull.octopus"))
562 return git_config_string(&pull_octopus, k, v);
7610fa57
JN
563 else if (!strcmp(k, "merge.renormalize"))
564 option_renormalize = git_config_bool(k, v);
898eacd8 565 else if (!strcmp(k, "merge.ff")) {
f23e8dec
JH
566 int boolval = git_config_maybe_bool(k, v);
567 if (0 <= boolval) {
568 allow_fast_forward = boolval;
569 } else if (v && !strcmp(v, "only")) {
570 allow_fast_forward = 1;
571 fast_forward_only = 1;
572 } /* do not barf on values from future versions of git */
573 return 0;
93e535a5
JH
574 } else if (!strcmp(k, "merge.defaulttoupstream")) {
575 default_to_upstream = git_config_bool(k, v);
576 return 0;
96e9420c 577 }
ba3c69a9 578
898eacd8 579 status = fmt_merge_msg_config(k, v, cb);
5de89d3a
JH
580 if (status)
581 return status;
ba3c69a9 582 status = git_gpg_config(k, v, NULL);
898eacd8
JH
583 if (status)
584 return status;
1c7b76be
MV
585 return git_diff_ui_config(k, v, cb);
586}
587
588static int read_tree_trivial(unsigned char *common, unsigned char *head,
589 unsigned char *one)
590{
591 int i, nr_trees = 0;
592 struct tree *trees[MAX_UNPACK_TREES];
593 struct tree_desc t[MAX_UNPACK_TREES];
594 struct unpack_trees_options opts;
595
596 memset(&opts, 0, sizeof(opts));
597 opts.head_idx = 2;
598 opts.src_index = &the_index;
599 opts.dst_index = &the_index;
600 opts.update = 1;
601 opts.verbose_update = 1;
602 opts.trivial_merges_only = 1;
603 opts.merge = 1;
604 trees[nr_trees] = parse_tree_indirect(common);
605 if (!trees[nr_trees++])
606 return -1;
607 trees[nr_trees] = parse_tree_indirect(head);
608 if (!trees[nr_trees++])
609 return -1;
610 trees[nr_trees] = parse_tree_indirect(one);
611 if (!trees[nr_trees++])
612 return -1;
613 opts.fn = threeway_merge;
614 cache_tree_free(&active_cache_tree);
615 for (i = 0; i < nr_trees; i++) {
616 parse_tree(trees[i]);
617 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
618 }
619 if (unpack_trees(nr_trees, t, &opts))
620 return -1;
621 return 0;
622}
623
624static void write_tree_trivial(unsigned char *sha1)
625{
626 if (write_cache_as_tree(sha1, 0, NULL))
bacec478 627 die(_("git write-tree failed to write a tree"));
1c7b76be
MV
628}
629
16180734
JK
630static const char *merge_argument(struct commit *commit)
631{
632 if (commit)
633 return sha1_to_hex(commit->object.sha1);
634 else
635 return EMPTY_TREE_SHA1_HEX;
636}
637
67ac1e1d
JN
638int try_merge_command(const char *strategy, size_t xopts_nr,
639 const char **xopts, struct commit_list *common,
c674d052 640 const char *head_arg, struct commit_list *remotes)
1c7b76be
MV
641{
642 const char **args;
8cc5b290 643 int i = 0, x = 0, ret;
1c7b76be 644 struct commit_list *j;
f285a2d7 645 struct strbuf buf = STRBUF_INIT;
3f9083cd
CC
646
647 args = xmalloc((4 + xopts_nr + commit_list_count(common) +
648 commit_list_count(remotes)) * sizeof(char *));
649 strbuf_addf(&buf, "merge-%s", strategy);
650 args[i++] = buf.buf;
651 for (x = 0; x < xopts_nr; x++) {
652 char *s = xmalloc(strlen(xopts[x])+2+1);
653 strcpy(s, "--");
654 strcpy(s+2, xopts[x]);
655 args[i++] = s;
656 }
657 for (j = common; j; j = j->next)
16180734 658 args[i++] = xstrdup(merge_argument(j->item));
3f9083cd
CC
659 args[i++] = "--";
660 args[i++] = head_arg;
661 for (j = remotes; j; j = j->next)
16180734 662 args[i++] = xstrdup(merge_argument(j->item));
3f9083cd
CC
663 args[i] = NULL;
664 ret = run_command_v_opt(args, RUN_GIT_CMD);
665 strbuf_release(&buf);
666 i = 1;
667 for (x = 0; x < xopts_nr; x++)
668 free((void *)args[i++]);
669 for (j = common; j; j = j->next)
670 free((void *)args[i++]);
671 i += 2;
672 for (j = remotes; j; j = j->next)
673 free((void *)args[i++]);
674 free(args);
675 discard_cache();
676 if (read_cache() < 0)
bacec478 677 die(_("failed to read the cache"));
3f9083cd
CC
678 resolve_undo_clear();
679
680 return ret;
681}
682
683static int try_merge_strategy(const char *strategy, struct commit_list *common,
894642f6 684 struct commit *head, const char *head_arg)
3f9083cd 685{
668f26ff
MV
686 int index_fd;
687 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
688
689 index_fd = hold_locked_index(lock, 1);
690 refresh_cache(REFRESH_QUIET);
691 if (active_cache_changed &&
692 (write_cache(index_fd, active_cache, active_nr) ||
693 commit_locked_index(lock)))
bacec478 694 return error(_("Unable to write index."));
668f26ff 695 rollback_lock_file(lock);
1c7b76be 696
18668f53 697 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
3f9083cd 698 int clean, x;
18668f53
MV
699 struct commit *result;
700 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
701 int index_fd;
702 struct commit_list *reversed = NULL;
703 struct merge_options o;
3f9083cd 704 struct commit_list *j;
18668f53
MV
705
706 if (remoteheads->next) {
bacec478 707 error(_("Not handling anything other than two heads merge."));
18668f53
MV
708 return 2;
709 }
710
711 init_merge_options(&o);
712 if (!strcmp(strategy, "subtree"))
85e51b78 713 o.subtree_shift = "";
8cc5b290 714
7610fa57 715 o.renormalize = option_renormalize;
99bfc669
JK
716 o.show_rename_progress =
717 show_progress == -1 ? isatty(2) : show_progress;
7610fa57 718
635a7bb1
JN
719 for (x = 0; x < xopts_nr; x++)
720 if (parse_merge_opt(&o, xopts[x]))
bacec478 721 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
18668f53
MV
722
723 o.branch1 = head_arg;
ae8e4c9c 724 o.branch2 = merge_remote_util(remoteheads->item)->name;
18668f53
MV
725
726 for (j = common; j; j = j->next)
727 commit_list_insert(j->item, &reversed);
728
729 index_fd = hold_locked_index(lock, 1);
894642f6 730 clean = merge_recursive(&o, head,
18668f53
MV
731 remoteheads->item, reversed, &result);
732 if (active_cache_changed &&
733 (write_cache(index_fd, active_cache, active_nr) ||
734 commit_locked_index(lock)))
bacec478 735 die (_("unable to write %s"), get_index_file());
42716660 736 rollback_lock_file(lock);
18668f53
MV
737 return clean ? 0 : 1;
738 } else {
67ac1e1d
JN
739 return try_merge_command(strategy, xopts_nr, xopts,
740 common, head_arg, remoteheads);
18668f53 741 }
1c7b76be
MV
742}
743
744static void count_diff_files(struct diff_queue_struct *q,
745 struct diff_options *opt, void *data)
746{
747 int *count = data;
748
749 (*count) += q->nr;
750}
751
752static int count_unmerged_entries(void)
753{
1c7b76be
MV
754 int i, ret = 0;
755
be6ff819
JH
756 for (i = 0; i < active_nr; i++)
757 if (ce_stage(active_cache[i]))
1c7b76be
MV
758 ret++;
759
760 return ret;
761}
762
cac42b26 763int checkout_fast_forward(const unsigned char *head, const unsigned char *remote)
1c7b76be
MV
764{
765 struct tree *trees[MAX_UNPACK_TREES];
766 struct unpack_trees_options opts;
767 struct tree_desc t[MAX_UNPACK_TREES];
768 int i, fd, nr_trees = 0;
769 struct dir_struct dir;
770 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
771
9ca8f607 772 refresh_cache(REFRESH_QUIET);
1c7b76be
MV
773
774 fd = hold_locked_index(lock_file, 1);
775
776 memset(&trees, 0, sizeof(trees));
777 memset(&opts, 0, sizeof(opts));
778 memset(&t, 0, sizeof(t));
c1d7036b
NTND
779 if (overwrite_ignore) {
780 memset(&dir, 0, sizeof(dir));
781 dir.flags |= DIR_SHOW_IGNORED;
782 setup_standard_excludes(&dir);
783 opts.dir = &dir;
784 }
1c7b76be
MV
785
786 opts.head_idx = 1;
787 opts.src_index = &the_index;
788 opts.dst_index = &the_index;
789 opts.update = 1;
790 opts.verbose_update = 1;
791 opts.merge = 1;
792 opts.fn = twoway_merge;
e294030f 793 setup_unpack_trees_porcelain(&opts, "merge");
1c7b76be
MV
794
795 trees[nr_trees] = parse_tree_indirect(head);
796 if (!trees[nr_trees++])
797 return -1;
798 trees[nr_trees] = parse_tree_indirect(remote);
799 if (!trees[nr_trees++])
800 return -1;
801 for (i = 0; i < nr_trees; i++) {
802 parse_tree(trees[i]);
803 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
804 }
805 if (unpack_trees(nr_trees, t, &opts))
806 return -1;
807 if (write_cache(fd, active_cache, active_nr) ||
808 commit_locked_index(lock_file))
bacec478 809 die(_("unable to write new index file"));
1c7b76be
MV
810 return 0;
811}
812
813static void split_merge_strategies(const char *string, struct strategy **list,
814 int *nr, int *alloc)
815{
816 char *p, *q, *buf;
817
818 if (!string)
819 return;
820
821 buf = xstrdup(string);
822 q = buf;
823 for (;;) {
824 p = strchr(q, ' ');
825 if (!p) {
826 ALLOC_GROW(*list, *nr + 1, *alloc);
827 (*list)[(*nr)++].name = xstrdup(q);
828 free(buf);
829 return;
830 } else {
831 *p = '\0';
832 ALLOC_GROW(*list, *nr + 1, *alloc);
833 (*list)[(*nr)++].name = xstrdup(q);
834 q = ++p;
835 }
836 }
837}
838
839static void add_strategies(const char *string, unsigned attr)
840{
841 struct strategy *list = NULL;
842 int list_alloc = 0, list_nr = 0, i;
843
844 memset(&list, 0, sizeof(list));
845 split_merge_strategies(string, &list, &list_nr, &list_alloc);
1719b5e4
MV
846 if (list) {
847 for (i = 0; i < list_nr; i++)
848 append_strategy(get_strategy(list[i].name));
1c7b76be
MV
849 return;
850 }
851 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
852 if (all_strategy[i].attr & attr)
853 append_strategy(&all_strategy[i]);
854
855}
856
66f4b98a 857static void write_merge_msg(struct strbuf *msg)
65969d43 858{
418c9b17
JN
859 const char *filename = git_path("MERGE_MSG");
860 int fd = open(filename, O_WRONLY | O_CREAT, 0666);
65969d43 861 if (fd < 0)
6c80cd29 862 die_errno(_("Could not open '%s' for writing"),
418c9b17 863 filename);
66f4b98a 864 if (write_in_full(fd, msg->buf, msg->len) != msg->len)
418c9b17 865 die_errno(_("Could not write to '%s'"), filename);
65969d43
JS
866 close(fd);
867}
868
66f4b98a 869static void read_merge_msg(struct strbuf *msg)
65969d43 870{
418c9b17 871 const char *filename = git_path("MERGE_MSG");
66f4b98a 872 strbuf_reset(msg);
418c9b17
JN
873 if (strbuf_read_file(msg, filename, 0) < 0)
874 die_errno(_("Could not read from '%s'"), filename);
65969d43
JS
875}
876
66f4b98a
JS
877static void write_merge_state(void);
878static void abort_commit(const char *err_msg)
65969d43 879{
66f4b98a
JS
880 if (err_msg)
881 error("%s", err_msg);
882 fprintf(stderr,
883 _("Not committing merge; use 'git commit' to complete the merge.\n"));
884 write_merge_state();
885 exit(1);
886}
887
f26af3fc
TR
888static const char merge_editor_comment[] =
889N_("Please enter a commit message to explain why this merge is necessary,\n"
890 "especially if it merges an updated upstream into a topic branch.\n"
891 "\n"
892 "Lines starting with '#' will be ignored, and an empty message aborts\n"
893 "the commit.\n");
894
66f4b98a
JS
895static void prepare_to_commit(void)
896{
897 struct strbuf msg = STRBUF_INIT;
f26af3fc 898 const char *comment = _(merge_editor_comment);
66f4b98a
JS
899 strbuf_addbuf(&msg, &merge_msg);
900 strbuf_addch(&msg, '\n');
f26af3fc
TR
901 if (0 < option_edit)
902 strbuf_add_lines(&msg, "# ", comment, strlen(comment));
66f4b98a 903 write_merge_msg(&msg);
65969d43
JS
904 run_hook(get_index_file(), "prepare-commit-msg",
905 git_path("MERGE_MSG"), "merge", NULL, NULL);
66f4b98a
JS
906 if (option_edit) {
907 if (launch_editor(git_path("MERGE_MSG"), NULL, NULL))
908 abort_commit(NULL);
909 }
910 read_merge_msg(&msg);
911 stripspace(&msg, option_edit);
912 if (!msg.len)
913 abort_commit(_("Empty commit message."));
914 strbuf_release(&merge_msg);
915 strbuf_addbuf(&merge_msg, &msg);
916 strbuf_release(&msg);
65969d43
JS
917}
918
894642f6 919static int merge_trivial(struct commit *head)
1c7b76be
MV
920{
921 unsigned char result_tree[20], result_commit[20];
36e40535 922 struct commit_list *parent = xmalloc(sizeof(*parent));
1c7b76be
MV
923
924 write_tree_trivial(result_tree);
157efde1 925 printf(_("Wonderful.\n"));
894642f6 926 parent->item = head;
36e40535 927 parent->next = xmalloc(sizeof(*parent->next));
446247db
JH
928 parent->next->item = remoteheads->item;
929 parent->next->next = NULL;
66f4b98a 930 prepare_to_commit();
5de89d3a
JH
931 if (commit_tree(&merge_msg, result_tree, parent, result_commit, NULL,
932 sign_commit))
6b3c4c05 933 die(_("failed to write commit object"));
894642f6 934 finish(head, result_commit, "In-index merge");
1c7b76be
MV
935 drop_save();
936 return 0;
937}
938
894642f6
NTND
939static int finish_automerge(struct commit *head,
940 struct commit_list *common,
1c7b76be
MV
941 unsigned char *result_tree,
942 const char *wt_strategy)
943{
944 struct commit_list *parents = NULL, *j;
945 struct strbuf buf = STRBUF_INIT;
946 unsigned char result_commit[20];
947
948 free_commit_list(common);
949 if (allow_fast_forward) {
950 parents = remoteheads;
894642f6 951 commit_list_insert(head, &parents);
1c7b76be
MV
952 parents = reduce_heads(parents);
953 } else {
954 struct commit_list **pptr = &parents;
955
894642f6 956 pptr = &commit_list_insert(head,
1c7b76be
MV
957 pptr)->next;
958 for (j = remoteheads; j; j = j->next)
959 pptr = &commit_list_insert(j->item, pptr)->next;
960 }
1c7b76be 961 strbuf_addch(&merge_msg, '\n');
66f4b98a
JS
962 prepare_to_commit();
963 free_commit_list(remoteheads);
5de89d3a
JH
964 if (commit_tree(&merge_msg, result_tree, parents, result_commit,
965 NULL, sign_commit))
6b3c4c05 966 die(_("failed to write commit object"));
f23101bf 967 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
894642f6 968 finish(head, result_commit, buf.buf);
1c7b76be
MV
969 strbuf_release(&buf);
970 drop_save();
971 return 0;
972}
973
7610fa57 974static int suggest_conflicts(int renormalizing)
1c7b76be 975{
418c9b17 976 const char *filename;
1c7b76be
MV
977 FILE *fp;
978 int pos;
979
418c9b17
JN
980 filename = git_path("MERGE_MSG");
981 fp = fopen(filename, "a");
1c7b76be 982 if (!fp)
418c9b17 983 die_errno(_("Could not open '%s' for writing"), filename);
1c7b76be
MV
984 fprintf(fp, "\nConflicts:\n");
985 for (pos = 0; pos < active_nr; pos++) {
986 struct cache_entry *ce = active_cache[pos];
987
988 if (ce_stage(ce)) {
989 fprintf(fp, "\t%s\n", ce->name);
990 while (pos + 1 < active_nr &&
991 !strcmp(ce->name,
992 active_cache[pos + 1]->name))
993 pos++;
994 }
995 }
996 fclose(fp);
cb6020bb 997 rerere(allow_rerere_auto);
bacec478
ÆAB
998 printf(_("Automatic merge failed; "
999 "fix conflicts and then commit the result.\n"));
1c7b76be
MV
1000 return 1;
1001}
1002
894642f6
NTND
1003static struct commit *is_old_style_invocation(int argc, const char **argv,
1004 const unsigned char *head)
1c7b76be
MV
1005{
1006 struct commit *second_token = NULL;
76bf488e 1007 if (argc > 2) {
1c7b76be
MV
1008 unsigned char second_sha1[20];
1009
1010 if (get_sha1(argv[1], second_sha1))
1011 return NULL;
1012 second_token = lookup_commit_reference_gently(second_sha1, 0);
1013 if (!second_token)
bacec478 1014 die(_("'%s' is not a commit"), argv[1]);
1c7b76be
MV
1015 if (hashcmp(second_token->object.sha1, head))
1016 return NULL;
1017 }
1018 return second_token;
1019}
1020
1021static int evaluate_result(void)
1022{
1023 int cnt = 0;
1024 struct rev_info rev;
1025
1c7b76be
MV
1026 /* Check how many files differ. */
1027 init_revisions(&rev, "");
1028 setup_revisions(0, NULL, &rev, NULL);
1029 rev.diffopt.output_format |=
1030 DIFF_FORMAT_CALLBACK;
1031 rev.diffopt.format_callback = count_diff_files;
1032 rev.diffopt.format_callback_data = &cnt;
1033 run_diff_files(&rev, 0);
1034
1035 /*
1036 * Check how many unmerged entries are
1037 * there.
1038 */
1039 cnt += count_unmerged_entries();
1040
1041 return cnt;
1042}
1043
93e535a5
JH
1044/*
1045 * Pretend as if the user told us to merge with the tracking
1046 * branch we have for the upstream of the current branch
1047 */
1048static int setup_with_upstream(const char ***argv)
1049{
1050 struct branch *branch = branch_get(NULL);
1051 int i;
1052 const char **args;
1053
1054 if (!branch)
c7f426d4 1055 die(_("No current branch."));
93e535a5 1056 if (!branch->remote)
c7f426d4 1057 die(_("No remote for the current branch."));
93e535a5 1058 if (!branch->merge_nr)
c7f426d4 1059 die(_("No default upstream defined for the current branch."));
93e535a5
JH
1060
1061 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
1062 for (i = 0; i < branch->merge_nr; i++) {
1063 if (!branch->merge[i]->dst)
c7f426d4 1064 die(_("No remote tracking branch for %s from %s"),
93e535a5
JH
1065 branch->merge[i]->src, branch->remote_name);
1066 args[i] = branch->merge[i]->dst;
1067 }
1068 args[i] = NULL;
1069 *argv = args;
1070 return i;
1071}
1072
66f4b98a
JS
1073static void write_merge_state(void)
1074{
418c9b17 1075 const char *filename;
66f4b98a
JS
1076 int fd;
1077 struct commit_list *j;
1078 struct strbuf buf = STRBUF_INIT;
1079
274a5c06
JH
1080 for (j = remoteheads; j; j = j->next) {
1081 unsigned const char *sha1;
1082 struct commit *c = j->item;
1083 if (c->util && merge_remote_util(c)->obj) {
1084 sha1 = merge_remote_util(c)->obj->sha1;
1085 } else {
1086 sha1 = c->object.sha1;
1087 }
1088 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
1089 }
418c9b17
JN
1090 filename = git_path("MERGE_HEAD");
1091 fd = open(filename, O_WRONLY | O_CREAT, 0666);
66f4b98a 1092 if (fd < 0)
418c9b17 1093 die_errno(_("Could not open '%s' for writing"), filename);
66f4b98a 1094 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
418c9b17 1095 die_errno(_("Could not write to '%s'"), filename);
66f4b98a
JS
1096 close(fd);
1097 strbuf_addch(&merge_msg, '\n');
1098 write_merge_msg(&merge_msg);
418c9b17
JN
1099
1100 filename = git_path("MERGE_MODE");
1101 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
66f4b98a 1102 if (fd < 0)
418c9b17 1103 die_errno(_("Could not open '%s' for writing"), filename);
66f4b98a
JS
1104 strbuf_reset(&buf);
1105 if (!allow_fast_forward)
1106 strbuf_addf(&buf, "no-ff");
1107 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
418c9b17 1108 die_errno(_("Could not write to '%s'"), filename);
66f4b98a
JS
1109 close(fd);
1110}
1111
d387868a
JH
1112static int default_edit_option(void)
1113{
1114 static const char name[] = "GIT_MERGE_AUTOEDIT";
1115 const char *e = getenv(name);
1116 struct stat st_stdin, st_stdout;
1117
1118 if (have_message)
1119 /* an explicit -m msg without --[no-]edit */
1120 return 0;
1121
1122 if (e) {
1123 int v = git_config_maybe_bool(name, e);
1124 if (v < 0)
1125 die("Bad value '%s' in environment '%s'", e, name);
1126 return v;
1127 }
1128
1129 /* Use editor if stdin and stdout are the same and is a tty */
1130 return (!fstat(0, &st_stdin) &&
1131 !fstat(1, &st_stdout) &&
1132 isatty(0) && isatty(1) &&
1133 st_stdin.st_dev == st_stdout.st_dev &&
1134 st_stdin.st_ino == st_stdout.st_ino &&
1135 st_stdin.st_mode == st_stdout.st_mode);
1136}
1137
1138
1c7b76be
MV
1139int cmd_merge(int argc, const char **argv, const char *prefix)
1140{
1141 unsigned char result_tree[20];
b4fd9406 1142 unsigned char stash[20];
894642f6
NTND
1143 unsigned char head_sha1[20];
1144 struct commit *head_commit;
f285a2d7 1145 struct strbuf buf = STRBUF_INIT;
1c7b76be 1146 const char *head_arg;
d5a35c11 1147 int flag, i, ret = 0;
1c7b76be
MV
1148 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1149 struct commit_list *common = NULL;
1150 const char *best_strategy = NULL, *wt_strategy = NULL;
1151 struct commit_list **remotes = &remoteheads;
96ec7b1e 1152 void *branch_to_free;
1c7b76be 1153
da53eec6
NTND
1154 if (argc == 2 && !strcmp(argv[1], "-h"))
1155 usage_with_options(builtin_merge_usage, builtin_merge_options);
1c7b76be
MV
1156
1157 /*
1158 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1159 * current branch.
1160 */
96ec7b1e
NTND
1161 branch = branch_to_free = resolve_refdup("HEAD", head_sha1, 0, &flag);
1162 if (branch && !prefixcmp(branch, "refs/heads/"))
1163 branch += 11;
894642f6
NTND
1164 if (!branch || is_null_sha1(head_sha1))
1165 head_commit = NULL;
baf18fc2
NTND
1166 else
1167 head_commit = lookup_commit_or_die(head_sha1, "HEAD");
1c7b76be
MV
1168
1169 git_config(git_merge_config, NULL);
1170
0d8fc3ef
JH
1171 if (branch_mergeoptions)
1172 parse_branch_merge_options(branch_mergeoptions);
37782920 1173 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1c7b76be 1174 builtin_merge_usage, 0);
898eacd8
JH
1175 if (shortlog_len < 0)
1176 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
2a22c1b3 1177
99bfc669
JK
1178 if (verbosity < 0 && show_progress == -1)
1179 show_progress = 0;
1180
35d2fffd
JH
1181 if (abort_current_merge) {
1182 int nargc = 2;
1183 const char *nargv[] = {"reset", "--merge", NULL};
1184
1185 if (!file_exists(git_path("MERGE_HEAD")))
bacec478 1186 die(_("There is no merge to abort (MERGE_HEAD missing)."));
35d2fffd
JH
1187
1188 /* Invoke 'git reset --merge' */
d5a35c11
NTND
1189 ret = cmd_reset(nargc, nargv, prefix);
1190 goto done;
35d2fffd
JH
1191 }
1192
2a22c1b3
JH
1193 if (read_cache_unmerged())
1194 die_resolve_conflict("merge");
1195
1196 if (file_exists(git_path("MERGE_HEAD"))) {
1197 /*
1198 * There is no unmerged entry, don't advise 'git
1199 * add/rm <file>', just 'git commit'.
1200 */
1201 if (advice_resolve_conflict)
bacec478
ÆAB
1202 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1203 "Please, commit your changes before you can merge."));
2a22c1b3 1204 else
bacec478 1205 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
2a22c1b3 1206 }
d7e5c0cb
JS
1207 if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
1208 if (advice_resolve_conflict)
f68f1801
ÆAB
1209 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1210 "Please, commit your changes before you can merge."));
d7e5c0cb 1211 else
f68f1801 1212 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
2a22c1b3
JH
1213 }
1214 resolve_undo_clear();
1215
7f87aff2
TA
1216 if (verbosity < 0)
1217 show_diffstat = 0;
1c7b76be
MV
1218
1219 if (squash) {
1220 if (!allow_fast_forward)
bacec478 1221 die(_("You cannot combine --squash with --no-ff."));
1c7b76be
MV
1222 option_commit = 0;
1223 }
1224
13474835 1225 if (!allow_fast_forward && fast_forward_only)
bacec478 1226 die(_("You cannot combine --no-ff with --ff-only."));
13474835 1227
4e8115ff 1228 if (!abort_current_merge) {
5480207c
VR
1229 if (!argc) {
1230 if (default_to_upstream)
1231 argc = setup_with_upstream(&argv);
1232 else
1233 die(_("No commit specified and merge.defaultToUpstream not set."));
1234 } else if (argc == 1 && !strcmp(argv[0], "-"))
4e8115ff
JH
1235 argv[0] = "@{-1}";
1236 }
1c7b76be
MV
1237 if (!argc)
1238 usage_with_options(builtin_merge_usage,
1239 builtin_merge_options);
1240
1241 /*
1242 * This could be traditional "merge <msg> HEAD <commit>..." and
1243 * the way we can tell it is to see if the second token is HEAD,
1244 * but some people might have misused the interface and used a
1245 * committish that is the same as HEAD there instead.
1246 * Traditional format never would have "-m" so it is an
1247 * additional safety measure to check for it.
1248 */
1c7b76be 1249
894642f6
NTND
1250 if (!have_message && head_commit &&
1251 is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
1c7b76be
MV
1252 strbuf_addstr(&merge_msg, argv[0]);
1253 head_arg = argv[1];
1254 argv += 2;
1255 argc -= 2;
894642f6 1256 } else if (!head_commit) {
ae8e4c9c 1257 struct commit *remote_head;
1c7b76be
MV
1258 /*
1259 * If the merged head is a valid one there is no reason
1260 * to forbid "git merge" into a branch yet to be born.
1261 * We do the same for "git pull".
1262 */
1263 if (argc != 1)
bacec478
ÆAB
1264 die(_("Can merge only exactly one commit into "
1265 "empty head"));
4be636f4 1266 if (squash)
bacec478 1267 die(_("Squash commit into empty head not supported yet"));
4be636f4 1268 if (!allow_fast_forward)
bacec478
ÆAB
1269 die(_("Non-fast-forward commit does not make sense into "
1270 "an empty head"));
ae8e4c9c 1271 remote_head = get_merge_parent(argv[0]);
1c7b76be 1272 if (!remote_head)
bacec478 1273 die(_("%s - not something we can merge"), argv[0]);
ae8e4c9c
JH
1274 read_empty(remote_head->object.sha1, 0);
1275 update_ref("initial pull", "HEAD", remote_head->object.sha1,
1276 NULL, 0, DIE_ON_ERR);
d5a35c11 1277 goto done;
1c7b76be 1278 } else {
97d45bcb 1279 struct strbuf merge_names = STRBUF_INIT;
1c7b76be
MV
1280
1281 /* We are invoked directly as the first-class UI. */
1282 head_arg = "HEAD";
1283
1284 /*
ae8e4c9c
JH
1285 * All the rest are the commits being merged; prepare
1286 * the standard merge summary message to be appended
1287 * to the given message.
1c7b76be 1288 */
f0ecac2b
TRC
1289 for (i = 0; i < argc; i++)
1290 merge_name(argv[i], &merge_names);
1291
96e9420c 1292 if (!have_message || shortlog_len) {
cbda121c
JH
1293 struct fmt_merge_msg_opts opts;
1294 memset(&opts, 0, sizeof(opts));
1295 opts.add_title = !have_message;
1296 opts.shortlog_len = shortlog_len;
1297
1298 fmt_merge_msg(&merge_names, &merge_msg, &opts);
1876166a
RR
1299 if (merge_msg.len)
1300 strbuf_setlen(&merge_msg, merge_msg.len - 1);
1301 }
1c7b76be
MV
1302 }
1303
894642f6 1304 if (!head_commit || !argc)
1c7b76be
MV
1305 usage_with_options(builtin_merge_usage,
1306 builtin_merge_options);
1307
1308 strbuf_addstr(&buf, "merge");
1309 for (i = 0; i < argc; i++)
1310 strbuf_addf(&buf, " %s", argv[i]);
1311 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1312 strbuf_reset(&buf);
1313
1314 for (i = 0; i < argc; i++) {
ae8e4c9c
JH
1315 struct commit *commit = get_merge_parent(argv[i]);
1316 if (!commit)
bacec478 1317 die(_("%s - not something we can merge"), argv[i]);
18668f53 1318 remotes = &commit_list_insert(commit, remotes)->next;
ae8e4c9c
JH
1319 strbuf_addf(&buf, "GITHEAD_%s",
1320 sha1_to_hex(commit->object.sha1));
1c7b76be
MV
1321 setenv(buf.buf, argv[i], 1);
1322 strbuf_reset(&buf);
b5c9f1c1
JH
1323 if (!fast_forward_only &&
1324 merge_remote_util(commit) &&
fab47d05
JH
1325 merge_remote_util(commit)->obj &&
1326 merge_remote_util(commit)->obj->type == OBJ_TAG) {
3adab6f3 1327 if (option_edit < 0)
d387868a 1328 option_edit = default_edit_option();
fab47d05
JH
1329 allow_fast_forward = 0;
1330 }
1c7b76be
MV
1331 }
1332
3adab6f3
JH
1333 if (option_edit < 0)
1334 option_edit = 0;
1335
1c7b76be
MV
1336 if (!use_strategies) {
1337 if (!remoteheads->next)
1338 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1339 else
1340 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1341 }
1342
1343 for (i = 0; i < use_strategies_nr; i++) {
1344 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1345 allow_fast_forward = 0;
1346 if (use_strategies[i]->attr & NO_TRIVIAL)
1347 allow_trivial = 0;
1348 }
1349
1350 if (!remoteheads->next)
894642f6 1351 common = get_merge_bases(head_commit, remoteheads->item, 1);
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
894642f6
NTND
1359 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
1360 NULL, 0, DIE_ON_ERR);
1c7b76be
MV
1361
1362 if (!common)
1363 ; /* No common ancestors found. We need a real merge. */
1364 else if (!remoteheads->next && !common->next &&
1365 common->item == remoteheads->item) {
1366 /*
1367 * If head can reach all the merge then we are up to date.
1368 * but first the most common case of merging one remote.
1369 */
1370 finish_up_to_date("Already up-to-date.");
d5a35c11 1371 goto done;
1c7b76be
MV
1372 } else if (allow_fast_forward && !remoteheads->next &&
1373 !common->next &&
894642f6 1374 !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
1c7b76be 1375 /* Again the most common case of merging one remote. */
f285a2d7 1376 struct strbuf msg = STRBUF_INIT;
ae8e4c9c 1377 struct commit *commit;
1c7b76be
MV
1378 char hex[41];
1379
894642f6 1380 strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
1c7b76be 1381
7f87aff2 1382 if (verbosity >= 0)
2ceb61e0 1383 printf(_("Updating %s..%s\n"),
7f87aff2
TA
1384 hex,
1385 find_unique_abbrev(remoteheads->item->object.sha1,
1386 DEFAULT_ABBREV));
a75d7b54 1387 strbuf_addstr(&msg, "Fast-forward");
1c7b76be
MV
1388 if (have_message)
1389 strbuf_addstr(&msg,
1390 " (no commit created; -m option ignored)");
ae8e4c9c 1391 commit = remoteheads->item;
b7f7c079 1392 if (!commit) {
d5a35c11
NTND
1393 ret = 1;
1394 goto done;
1395 }
1c7b76be 1396
ae8e4c9c 1397 if (checkout_fast_forward(head_commit->object.sha1,
b7f7c079 1398 commit->object.sha1)) {
d5a35c11
NTND
1399 ret = 1;
1400 goto done;
1401 }
1c7b76be 1402
ae8e4c9c 1403 finish(head_commit, commit->object.sha1, msg.buf);
1c7b76be 1404 drop_save();
d5a35c11 1405 goto done;
1c7b76be
MV
1406 } else if (!remoteheads->next && common->next)
1407 ;
1408 /*
a75d7b54 1409 * We are not doing octopus and not fast-forward. Need
1c7b76be
MV
1410 * a real merge.
1411 */
1412 else if (!remoteheads->next && !common->next && option_commit) {
1413 /*
a75d7b54 1414 * We are not doing octopus, not fast-forward, and have
1c7b76be
MV
1415 * only one common.
1416 */
1417 refresh_cache(REFRESH_QUIET);
13474835 1418 if (allow_trivial && !fast_forward_only) {
1c7b76be
MV
1419 /* See if it is really trivial. */
1420 git_committer_info(IDENT_ERROR_ON_NO_NAME);
bacec478 1421 printf(_("Trying really trivial in-index merge...\n"));
1c7b76be 1422 if (!read_tree_trivial(common->item->object.sha1,
d5a35c11
NTND
1423 head_commit->object.sha1,
1424 remoteheads->item->object.sha1)) {
1425 ret = merge_trivial(head_commit);
1426 goto done;
1427 }
bacec478 1428 printf(_("Nope.\n"));
1c7b76be
MV
1429 }
1430 } else {
1431 /*
1432 * An octopus. If we can reach all the remote we are up
1433 * to date.
1434 */
1435 int up_to_date = 1;
1436 struct commit_list *j;
1437
1438 for (j = remoteheads; j; j = j->next) {
1439 struct commit_list *common_one;
1440
1441 /*
1442 * Here we *have* to calculate the individual
1443 * merge_bases again, otherwise "git merge HEAD^
1444 * HEAD^^" would be missed.
1445 */
894642f6 1446 common_one = get_merge_bases(head_commit, j->item, 1);
1c7b76be
MV
1447 if (hashcmp(common_one->item->object.sha1,
1448 j->item->object.sha1)) {
1449 up_to_date = 0;
1450 break;
1451 }
1452 }
1453 if (up_to_date) {
1454 finish_up_to_date("Already up-to-date. Yeeah!");
d5a35c11 1455 goto done;
1c7b76be
MV
1456 }
1457 }
1458
13474835 1459 if (fast_forward_only)
bacec478 1460 die(_("Not possible to fast-forward, aborting."));
13474835 1461
1c7b76be
MV
1462 /* We are going to make a new commit. */
1463 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1464
1465 /*
1466 * At this point, we need a real merge. No matter what strategy
1467 * we use, it would operate on the index, possibly affecting the
1468 * working tree, and when resolved cleanly, have the desired
1469 * tree in the index -- this means that the index must be in
1470 * sync with the head commit. The strategies are responsible
1471 * to ensure this.
1472 */
b4fd9406
NTND
1473 if (use_strategies_nr == 1 ||
1474 /*
1475 * Stash away the local changes so that we can try more than one.
1476 */
1477 save_state(stash))
1478 hashcpy(stash, null_sha1);
1c7b76be
MV
1479
1480 for (i = 0; i < use_strategies_nr; i++) {
1481 int ret;
1482 if (i) {
bacec478 1483 printf(_("Rewinding the tree to pristine...\n"));
894642f6 1484 restore_state(head_commit->object.sha1, stash);
1c7b76be
MV
1485 }
1486 if (use_strategies_nr != 1)
bacec478 1487 printf(_("Trying merge strategy %s...\n"),
1c7b76be
MV
1488 use_strategies[i]->name);
1489 /*
1490 * Remember which strategy left the state in the working
1491 * tree.
1492 */
1493 wt_strategy = use_strategies[i]->name;
1494
1495 ret = try_merge_strategy(use_strategies[i]->name,
894642f6 1496 common, head_commit, head_arg);
1c7b76be
MV
1497 if (!option_commit && !ret) {
1498 merge_was_ok = 1;
1499 /*
1500 * This is necessary here just to avoid writing
1501 * the tree, but later we will *not* exit with
1502 * status code 1 because merge_was_ok is set.
1503 */
1504 ret = 1;
1505 }
1506
1507 if (ret) {
1508 /*
1509 * The backend exits with 1 when conflicts are
1510 * left to be resolved, with 2 when it does not
1511 * handle the given merge at all.
1512 */
1513 if (ret == 1) {
1514 int cnt = evaluate_result();
1515
1516 if (best_cnt <= 0 || cnt <= best_cnt) {
1517 best_strategy = use_strategies[i]->name;
1518 best_cnt = cnt;
1519 }
1520 }
1521 if (merge_was_ok)
1522 break;
1523 else
1524 continue;
1525 }
1526
1527 /* Automerge succeeded. */
1528 write_tree_trivial(result_tree);
1529 automerge_was_ok = 1;
1530 break;
1531 }
1532
1533 /*
1534 * If we have a resulting tree, that means the strategy module
1535 * auto resolved the merge cleanly.
1536 */
d5a35c11
NTND
1537 if (automerge_was_ok) {
1538 ret = finish_automerge(head_commit, common, result_tree,
1539 wt_strategy);
1540 goto done;
1541 }
1c7b76be
MV
1542
1543 /*
1544 * Pick the result from the best strategy and have the user fix
1545 * it up.
1546 */
1547 if (!best_strategy) {
894642f6 1548 restore_state(head_commit->object.sha1, stash);
1c7b76be
MV
1549 if (use_strategies_nr > 1)
1550 fprintf(stderr,
bacec478 1551 _("No merge strategy handled the merge.\n"));
1c7b76be 1552 else
bacec478 1553 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1c7b76be 1554 use_strategies[0]->name);
d5a35c11
NTND
1555 ret = 2;
1556 goto done;
1c7b76be
MV
1557 } else if (best_strategy == wt_strategy)
1558 ; /* We already have its result in the working tree. */
1559 else {
bacec478 1560 printf(_("Rewinding the tree to pristine...\n"));
894642f6 1561 restore_state(head_commit->object.sha1, stash);
bacec478 1562 printf(_("Using the %s to prepare resolving by hand.\n"),
1c7b76be 1563 best_strategy);
894642f6 1564 try_merge_strategy(best_strategy, common, head_commit, head_arg);
1c7b76be
MV
1565 }
1566
1567 if (squash)
894642f6 1568 finish(head_commit, NULL, NULL);
66f4b98a
JS
1569 else
1570 write_merge_state();
1c7b76be 1571
d5a35c11 1572 if (merge_was_ok)
bacec478
ÆAB
1573 fprintf(stderr, _("Automatic merge went well; "
1574 "stopped before committing as requested\n"));
d5a35c11
NTND
1575 else
1576 ret = suggest_conflicts(option_renormalize);
1577
1578done:
96ec7b1e 1579 free(branch_to_free);
d5a35c11 1580 return ret;
1c7b76be 1581}