Git 1.7.7
[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"
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MV
29
30#define DEFAULT_TWOHEAD (1<<0)
31#define DEFAULT_OCTOPUS (1<<1)
32#define NO_FAST_FORWARD (1<<2)
33#define NO_TRIVIAL (1<<3)
34
35struct strategy {
36 const char *name;
37 unsigned attr;
38};
39
40static const char * const builtin_merge_usage[] = {
93e535a5 41 "git merge [options] [<commit>...]",
c395c25b
JH
42 "git merge [options] <msg> HEAD <commit>",
43 "git merge --abort",
1c7b76be
MV
44 NULL
45};
46
96e9420c 47static int show_diffstat = 1, shortlog_len, squash;
1c7b76be 48static int option_commit = 1, allow_fast_forward = 1;
13474835 49static int fast_forward_only;
1c7b76be
MV
50static int allow_trivial = 1, have_message;
51static struct strbuf merge_msg;
52static struct commit_list *remoteheads;
53static unsigned char head[20], stash[20];
54static struct strategy **use_strategies;
55static size_t use_strategies_nr, use_strategies_alloc;
8cc5b290
AP
56static const char **xopts;
57static size_t xopts_nr, xopts_alloc;
1c7b76be 58static const char *branch;
0d8fc3ef 59static char *branch_mergeoptions;
7610fa57 60static int option_renormalize;
7f87aff2 61static int verbosity;
cb6020bb 62static int allow_rerere_auto;
35d2fffd 63static int abort_current_merge;
99bfc669 64static int show_progress = -1;
93e535a5 65static int default_to_upstream;
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MV
66
67static struct strategy all_strategy[] = {
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MV
68 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
69 { "octopus", DEFAULT_OCTOPUS },
70 { "resolve", 0 },
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MV
71 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
72 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
73};
74
75static const char *pull_twohead, *pull_octopus;
76
77static int option_parse_message(const struct option *opt,
78 const char *arg, int unset)
79{
80 struct strbuf *buf = opt->value;
81
82 if (unset)
83 strbuf_setlen(buf, 0);
74f5b7fb 84 else if (arg) {
ce9d823b 85 strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
1c7b76be 86 have_message = 1;
74f5b7fb 87 } else
bacec478 88 return error(_("switch `m' requires a value"));
1c7b76be
MV
89 return 0;
90}
91
92static struct strategy *get_strategy(const char *name)
93{
94 int i;
87091b49
MV
95 struct strategy *ret;
96 static struct cmdnames main_cmds, other_cmds;
e321180e 97 static int loaded;
1c7b76be
MV
98
99 if (!name)
100 return NULL;
101
102 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
103 if (!strcmp(name, all_strategy[i].name))
104 return &all_strategy[i];
1719b5e4 105
e321180e 106 if (!loaded) {
87091b49 107 struct cmdnames not_strategies;
e321180e 108 loaded = 1;
87091b49 109
87091b49 110 memset(&not_strategies, 0, sizeof(struct cmdnames));
e321180e 111 load_command_list("git-merge-", &main_cmds, &other_cmds);
87091b49
MV
112 for (i = 0; i < main_cmds.cnt; i++) {
113 int j, found = 0;
114 struct cmdname *ent = main_cmds.names[i];
115 for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
116 if (!strncmp(ent->name, all_strategy[j].name, ent->len)
117 && !all_strategy[j].name[ent->len])
118 found = 1;
119 if (!found)
120 add_cmdname(&not_strategies, ent->name, ent->len);
87091b49 121 }
ed874656 122 exclude_cmds(&main_cmds, &not_strategies);
87091b49
MV
123 }
124 if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
bacec478
ÆAB
125 fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
126 fprintf(stderr, _("Available strategies are:"));
131f9a10
JH
127 for (i = 0; i < main_cmds.cnt; i++)
128 fprintf(stderr, " %s", main_cmds.names[i]->name);
129 fprintf(stderr, ".\n");
130 if (other_cmds.cnt) {
bacec478 131 fprintf(stderr, _("Available custom strategies are:"));
131f9a10
JH
132 for (i = 0; i < other_cmds.cnt; i++)
133 fprintf(stderr, " %s", other_cmds.names[i]->name);
134 fprintf(stderr, ".\n");
135 }
87091b49
MV
136 exit(1);
137 }
138
19d4b416 139 ret = xcalloc(1, sizeof(struct strategy));
87091b49 140 ret->name = xstrdup(name);
52b48ef1 141 ret->attr = NO_TRIVIAL;
87091b49 142 return ret;
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MV
143}
144
145static void append_strategy(struct strategy *s)
146{
147 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
148 use_strategies[use_strategies_nr++] = s;
149}
150
151static int option_parse_strategy(const struct option *opt,
152 const char *name, int unset)
153{
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154 if (unset)
155 return 0;
156
1719b5e4 157 append_strategy(get_strategy(name));
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MV
158 return 0;
159}
160
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AP
161static int option_parse_x(const struct option *opt,
162 const char *arg, int unset)
163{
164 if (unset)
165 return 0;
166
167 ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
168 xopts[xopts_nr++] = xstrdup(arg);
169 return 0;
170}
171
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MV
172static int option_parse_n(const struct option *opt,
173 const char *arg, int unset)
174{
175 show_diffstat = unset;
176 return 0;
177}
178
179static struct option builtin_merge_options[] = {
180 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
181 "do not show a diffstat at the end of the merge",
182 PARSE_OPT_NOARG, option_parse_n },
183 OPT_BOOLEAN(0, "stat", &show_diffstat,
184 "show a diffstat at the end of the merge"),
185 OPT_BOOLEAN(0, "summary", &show_diffstat, "(synonym to --stat)"),
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RR
186 { OPTION_INTEGER, 0, "log", &shortlog_len, "n",
187 "add (at most <n>) entries from shortlog to merge commit message",
188 PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
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189 OPT_BOOLEAN(0, "squash", &squash,
190 "create a single commit instead of doing a merge"),
191 OPT_BOOLEAN(0, "commit", &option_commit,
192 "perform a commit if the merge succeeds (default)"),
193 OPT_BOOLEAN(0, "ff", &allow_fast_forward,
a75d7b54 194 "allow fast-forward (default)"),
13474835 195 OPT_BOOLEAN(0, "ff-only", &fast_forward_only,
4d8c3258 196 "abort if fast-forward is not possible"),
cb6020bb 197 OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
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MV
198 OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
199 "merge strategy to use", option_parse_strategy),
8cc5b290
AP
200 OPT_CALLBACK('X', "strategy-option", &xopts, "option=value",
201 "option for selected merge strategy", option_parse_x),
23c6a803 202 OPT_CALLBACK('m', "message", &merge_msg, "message",
3f406175 203 "merge commit message (for a non-fast-forward merge)",
1c7b76be 204 option_parse_message),
7f87aff2 205 OPT__VERBOSITY(&verbosity),
35d2fffd
JH
206 OPT_BOOLEAN(0, "abort", &abort_current_merge,
207 "abort the current in-progress merge"),
99bfc669 208 OPT_SET_INT(0, "progress", &show_progress, "force progress reporting", 1),
1c7b76be
MV
209 OPT_END()
210};
211
212/* Cleans up metadata that is uninteresting after a succeeded merge. */
213static void drop_save(void)
214{
215 unlink(git_path("MERGE_HEAD"));
216 unlink(git_path("MERGE_MSG"));
cf10f9fd 217 unlink(git_path("MERGE_MODE"));
1c7b76be
MV
218}
219
220static void save_state(void)
221{
222 int len;
223 struct child_process cp;
224 struct strbuf buffer = STRBUF_INIT;
225 const char *argv[] = {"stash", "create", NULL};
226
227 memset(&cp, 0, sizeof(cp));
228 cp.argv = argv;
229 cp.out = -1;
230 cp.git_cmd = 1;
231
232 if (start_command(&cp))
bacec478 233 die(_("could not run stash."));
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MV
234 len = strbuf_read(&buffer, cp.out, 1024);
235 close(cp.out);
236
237 if (finish_command(&cp) || len < 0)
bacec478 238 die(_("stash failed"));
1c7b76be
MV
239 else if (!len)
240 return;
241 strbuf_setlen(&buffer, buffer.len-1);
242 if (get_sha1(buffer.buf, stash))
bacec478 243 die(_("not a valid object: %s"), buffer.buf);
1c7b76be
MV
244}
245
172b6428
CB
246static void read_empty(unsigned const char *sha1, int verbose)
247{
248 int i = 0;
249 const char *args[7];
250
251 args[i++] = "read-tree";
252 if (verbose)
253 args[i++] = "-v";
254 args[i++] = "-m";
255 args[i++] = "-u";
256 args[i++] = EMPTY_TREE_SHA1_HEX;
257 args[i++] = sha1_to_hex(sha1);
258 args[i] = NULL;
259
260 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 261 die(_("read-tree failed"));
172b6428
CB
262}
263
1c7b76be
MV
264static void reset_hard(unsigned const char *sha1, int verbose)
265{
266 int i = 0;
267 const char *args[6];
268
269 args[i++] = "read-tree";
270 if (verbose)
271 args[i++] = "-v";
272 args[i++] = "--reset";
273 args[i++] = "-u";
274 args[i++] = sha1_to_hex(sha1);
275 args[i] = NULL;
276
277 if (run_command_v_opt(args, RUN_GIT_CMD))
bacec478 278 die(_("read-tree failed"));
1c7b76be
MV
279}
280
281static void restore_state(void)
282{
f285a2d7 283 struct strbuf sb = STRBUF_INIT;
1c7b76be
MV
284 const char *args[] = { "stash", "apply", NULL, NULL };
285
286 if (is_null_sha1(stash))
287 return;
288
289 reset_hard(head, 1);
290
1c7b76be
MV
291 args[2] = sha1_to_hex(stash);
292
293 /*
294 * It is OK to ignore error here, for example when there was
295 * nothing to restore.
296 */
297 run_command_v_opt(args, RUN_GIT_CMD);
298
299 strbuf_release(&sb);
300 refresh_cache(REFRESH_QUIET);
301}
302
303/* This is called when no merge was necessary. */
304static void finish_up_to_date(const char *msg)
305{
7f87aff2 306 if (verbosity >= 0)
bacec478 307 printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
1c7b76be
MV
308 drop_save();
309}
310
311static void squash_message(void)
312{
313 struct rev_info rev;
314 struct commit *commit;
f285a2d7 315 struct strbuf out = STRBUF_INIT;
1c7b76be
MV
316 struct commit_list *j;
317 int fd;
dd2e794a 318 struct pretty_print_context ctx = {0};
1c7b76be 319
bacec478 320 printf(_("Squash commit -- not updating HEAD\n"));
1c7b76be
MV
321 fd = open(git_path("SQUASH_MSG"), O_WRONLY | O_CREAT, 0666);
322 if (fd < 0)
bacec478 323 die_errno(_("Could not write to '%s'"), git_path("SQUASH_MSG"));
1c7b76be
MV
324
325 init_revisions(&rev, NULL);
326 rev.ignore_merges = 1;
327 rev.commit_format = CMIT_FMT_MEDIUM;
328
329 commit = lookup_commit(head);
330 commit->object.flags |= UNINTERESTING;
331 add_pending_object(&rev, &commit->object, NULL);
332
333 for (j = remoteheads; j; j = j->next)
334 add_pending_object(&rev, &j->item->object, NULL);
335
336 setup_revisions(0, NULL, &rev, NULL);
337 if (prepare_revision_walk(&rev))
bacec478 338 die(_("revision walk setup failed"));
1c7b76be 339
dd2e794a
TR
340 ctx.abbrev = rev.abbrev;
341 ctx.date_mode = rev.date_mode;
6bf13944 342 ctx.fmt = rev.commit_format;
dd2e794a 343
1c7b76be
MV
344 strbuf_addstr(&out, "Squashed commit of the following:\n");
345 while ((commit = get_revision(&rev)) != NULL) {
346 strbuf_addch(&out, '\n');
347 strbuf_addf(&out, "commit %s\n",
348 sha1_to_hex(commit->object.sha1));
6bf13944 349 pretty_print_commit(&ctx, commit, &out);
1c7b76be 350 }
47d32af2 351 if (write(fd, out.buf, out.len) < 0)
bacec478 352 die_errno(_("Writing SQUASH_MSG"));
47d32af2 353 if (close(fd))
bacec478 354 die_errno(_("Finishing SQUASH_MSG"));
1c7b76be
MV
355 strbuf_release(&out);
356}
357
1c7b76be
MV
358static void finish(const unsigned char *new_head, const char *msg)
359{
f285a2d7 360 struct strbuf reflog_message = STRBUF_INIT;
1c7b76be 361
1c7b76be
MV
362 if (!msg)
363 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
364 else {
7f87aff2
TA
365 if (verbosity >= 0)
366 printf("%s\n", msg);
1c7b76be
MV
367 strbuf_addf(&reflog_message, "%s: %s",
368 getenv("GIT_REFLOG_ACTION"), msg);
369 }
370 if (squash) {
371 squash_message();
372 } else {
7f87aff2 373 if (verbosity >= 0 && !merge_msg.len)
bacec478 374 printf(_("No merge message -- not updating HEAD\n"));
1c7b76be
MV
375 else {
376 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
377 update_ref(reflog_message.buf, "HEAD",
378 new_head, head, 0,
379 DIE_ON_ERR);
380 /*
381 * We ignore errors in 'gc --auto', since the
382 * user should see them.
383 */
384 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
385 }
386 }
387 if (new_head && show_diffstat) {
388 struct diff_options opts;
389 diff_setup(&opts);
390 opts.output_format |=
391 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
392 opts.detect_rename = DIFF_DETECT_RENAME;
1c7b76be 393 if (diff_setup_done(&opts) < 0)
bacec478 394 die(_("diff_setup_done failed"));
1c7b76be
MV
395 diff_tree_sha1(head, new_head, "", &opts);
396 diffcore_std(&opts);
397 diff_flush(&opts);
398 }
399
400 /* Run a post-merge hook */
ae98a008 401 run_hook(NULL, "post-merge", squash ? "1" : "0", NULL);
1c7b76be
MV
402
403 strbuf_release(&reflog_message);
404}
405
406/* Get the name for the merge commit's message. */
407static void merge_name(const char *remote, struct strbuf *msg)
408{
409 struct object *remote_head;
410 unsigned char branch_head[20], buf_sha[20];
f285a2d7 411 struct strbuf buf = STRBUF_INIT;
c9717ee9 412 struct strbuf bname = STRBUF_INIT;
1c7b76be 413 const char *ptr;
751c5974 414 char *found_ref;
1c7b76be
MV
415 int len, early;
416
a552de75
JH
417 strbuf_branchname(&bname, remote);
418 remote = bname.buf;
c9717ee9 419
1c7b76be
MV
420 memset(branch_head, 0, sizeof(branch_head));
421 remote_head = peel_to_type(remote, 0, NULL, OBJ_COMMIT);
422 if (!remote_head)
bacec478 423 die(_("'%s' does not point to a commit"), remote);
1c7b76be 424
751c5974
JK
425 if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
426 if (!prefixcmp(found_ref, "refs/heads/")) {
427 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
428 sha1_to_hex(branch_head), remote);
429 goto cleanup;
430 }
69a8b7c7 431 if (!prefixcmp(found_ref, "refs/remotes/")) {
13931236 432 strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
69a8b7c7
JK
433 sha1_to_hex(branch_head), remote);
434 goto cleanup;
435 }
1c7b76be
MV
436 }
437
438 /* See if remote matches <name>^^^.. or <name>~<number> */
439 for (len = 0, ptr = remote + strlen(remote);
440 remote < ptr && ptr[-1] == '^';
441 ptr--)
442 len++;
443 if (len)
444 early = 1;
445 else {
446 early = 0;
447 ptr = strrchr(remote, '~');
448 if (ptr) {
449 int seen_nonzero = 0;
450
451 len++; /* count ~ */
452 while (*++ptr && isdigit(*ptr)) {
453 seen_nonzero |= (*ptr != '0');
454 len++;
455 }
456 if (*ptr)
457 len = 0; /* not ...~<number> */
458 else if (seen_nonzero)
459 early = 1;
460 else if (len == 1)
461 early = 1; /* "name~" is "name~1"! */
462 }
463 }
464 if (len) {
465 struct strbuf truname = STRBUF_INIT;
466 strbuf_addstr(&truname, "refs/heads/");
467 strbuf_addstr(&truname, remote);
9b6bf4d5 468 strbuf_setlen(&truname, truname.len - len);
b81f925f 469 if (resolve_ref(truname.buf, buf_sha, 1, NULL)) {
1c7b76be
MV
470 strbuf_addf(msg,
471 "%s\t\tbranch '%s'%s of .\n",
472 sha1_to_hex(remote_head->sha1),
9b6bf4d5 473 truname.buf + 11,
1c7b76be 474 (early ? " (early part)" : ""));
c9717ee9
JH
475 strbuf_release(&truname);
476 goto cleanup;
1c7b76be
MV
477 }
478 }
479
480 if (!strcmp(remote, "FETCH_HEAD") &&
481 !access(git_path("FETCH_HEAD"), R_OK)) {
482 FILE *fp;
f285a2d7 483 struct strbuf line = STRBUF_INIT;
1c7b76be
MV
484 char *ptr;
485
1c7b76be
MV
486 fp = fopen(git_path("FETCH_HEAD"), "r");
487 if (!fp)
bacec478 488 die_errno(_("could not open '%s' for reading"),
d824cbba 489 git_path("FETCH_HEAD"));
1c7b76be
MV
490 strbuf_getline(&line, fp, '\n');
491 fclose(fp);
492 ptr = strstr(line.buf, "\tnot-for-merge\t");
493 if (ptr)
494 strbuf_remove(&line, ptr-line.buf+1, 13);
495 strbuf_addbuf(msg, &line);
496 strbuf_release(&line);
c9717ee9 497 goto cleanup;
1c7b76be
MV
498 }
499 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
500 sha1_to_hex(remote_head->sha1), remote);
c9717ee9
JH
501cleanup:
502 strbuf_release(&buf);
503 strbuf_release(&bname);
1c7b76be
MV
504}
505
0d8fc3ef
JH
506static void parse_branch_merge_options(char *bmo)
507{
508 const char **argv;
509 int argc;
510
511 if (!bmo)
512 return;
513 argc = split_cmdline(bmo, &argv);
514 if (argc < 0)
c7fe5b61
JH
515 die(_("Bad branch.%s.mergeoptions string: %s"), branch,
516 split_cmdline_strerror(argc));
0d8fc3ef
JH
517 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
518 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
519 argc++;
520 argv[0] = "branch.*.mergeoptions";
521 parse_options(argc, argv, NULL, builtin_merge_options,
522 builtin_merge_usage, 0);
523 free(argv);
524}
525
186458b1 526static int git_merge_config(const char *k, const char *v, void *cb)
1c7b76be
MV
527{
528 if (branch && !prefixcmp(k, "branch.") &&
529 !prefixcmp(k + 7, branch) &&
530 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
0d8fc3ef
JH
531 free(branch_mergeoptions);
532 branch_mergeoptions = xstrdup(v);
533 return 0;
1c7b76be
MV
534 }
535
536 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
537 show_diffstat = git_config_bool(k, v);
538 else if (!strcmp(k, "pull.twohead"))
539 return git_config_string(&pull_twohead, k, v);
540 else if (!strcmp(k, "pull.octopus"))
541 return git_config_string(&pull_octopus, k, v);
7610fa57
JN
542 else if (!strcmp(k, "merge.renormalize"))
543 option_renormalize = git_config_bool(k, v);
96e9420c 544 else if (!strcmp(k, "merge.log") || !strcmp(k, "merge.summary")) {
bda3b8ff
RR
545 int is_bool;
546 shortlog_len = git_config_bool_or_int(k, v, &is_bool);
547 if (!is_bool && shortlog_len < 0)
bacec478 548 return error(_("%s: negative length %s"), k, v);
bda3b8ff
RR
549 if (is_bool && shortlog_len)
550 shortlog_len = DEFAULT_MERGE_LOG_LEN;
96e9420c 551 return 0;
f23e8dec
JH
552 } else if (!strcmp(k, "merge.ff")) {
553 int boolval = git_config_maybe_bool(k, v);
554 if (0 <= boolval) {
555 allow_fast_forward = boolval;
556 } else if (v && !strcmp(v, "only")) {
557 allow_fast_forward = 1;
558 fast_forward_only = 1;
559 } /* do not barf on values from future versions of git */
560 return 0;
93e535a5
JH
561 } else if (!strcmp(k, "merge.defaulttoupstream")) {
562 default_to_upstream = git_config_bool(k, v);
563 return 0;
96e9420c 564 }
1c7b76be
MV
565 return git_diff_ui_config(k, v, cb);
566}
567
568static int read_tree_trivial(unsigned char *common, unsigned char *head,
569 unsigned char *one)
570{
571 int i, nr_trees = 0;
572 struct tree *trees[MAX_UNPACK_TREES];
573 struct tree_desc t[MAX_UNPACK_TREES];
574 struct unpack_trees_options opts;
575
576 memset(&opts, 0, sizeof(opts));
577 opts.head_idx = 2;
578 opts.src_index = &the_index;
579 opts.dst_index = &the_index;
580 opts.update = 1;
581 opts.verbose_update = 1;
582 opts.trivial_merges_only = 1;
583 opts.merge = 1;
584 trees[nr_trees] = parse_tree_indirect(common);
585 if (!trees[nr_trees++])
586 return -1;
587 trees[nr_trees] = parse_tree_indirect(head);
588 if (!trees[nr_trees++])
589 return -1;
590 trees[nr_trees] = parse_tree_indirect(one);
591 if (!trees[nr_trees++])
592 return -1;
593 opts.fn = threeway_merge;
594 cache_tree_free(&active_cache_tree);
595 for (i = 0; i < nr_trees; i++) {
596 parse_tree(trees[i]);
597 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
598 }
599 if (unpack_trees(nr_trees, t, &opts))
600 return -1;
601 return 0;
602}
603
604static void write_tree_trivial(unsigned char *sha1)
605{
606 if (write_cache_as_tree(sha1, 0, NULL))
bacec478 607 die(_("git write-tree failed to write a tree"));
1c7b76be
MV
608}
609
16180734
JK
610static const char *merge_argument(struct commit *commit)
611{
612 if (commit)
613 return sha1_to_hex(commit->object.sha1);
614 else
615 return EMPTY_TREE_SHA1_HEX;
616}
617
67ac1e1d
JN
618int try_merge_command(const char *strategy, size_t xopts_nr,
619 const char **xopts, struct commit_list *common,
c674d052 620 const char *head_arg, struct commit_list *remotes)
1c7b76be
MV
621{
622 const char **args;
8cc5b290 623 int i = 0, x = 0, ret;
1c7b76be 624 struct commit_list *j;
f285a2d7 625 struct strbuf buf = STRBUF_INIT;
3f9083cd
CC
626
627 args = xmalloc((4 + xopts_nr + commit_list_count(common) +
628 commit_list_count(remotes)) * sizeof(char *));
629 strbuf_addf(&buf, "merge-%s", strategy);
630 args[i++] = buf.buf;
631 for (x = 0; x < xopts_nr; x++) {
632 char *s = xmalloc(strlen(xopts[x])+2+1);
633 strcpy(s, "--");
634 strcpy(s+2, xopts[x]);
635 args[i++] = s;
636 }
637 for (j = common; j; j = j->next)
16180734 638 args[i++] = xstrdup(merge_argument(j->item));
3f9083cd
CC
639 args[i++] = "--";
640 args[i++] = head_arg;
641 for (j = remotes; j; j = j->next)
16180734 642 args[i++] = xstrdup(merge_argument(j->item));
3f9083cd
CC
643 args[i] = NULL;
644 ret = run_command_v_opt(args, RUN_GIT_CMD);
645 strbuf_release(&buf);
646 i = 1;
647 for (x = 0; x < xopts_nr; x++)
648 free((void *)args[i++]);
649 for (j = common; j; j = j->next)
650 free((void *)args[i++]);
651 i += 2;
652 for (j = remotes; j; j = j->next)
653 free((void *)args[i++]);
654 free(args);
655 discard_cache();
656 if (read_cache() < 0)
bacec478 657 die(_("failed to read the cache"));
3f9083cd
CC
658 resolve_undo_clear();
659
660 return ret;
661}
662
663static int try_merge_strategy(const char *strategy, struct commit_list *common,
664 const char *head_arg)
665{
668f26ff
MV
666 int index_fd;
667 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
668
669 index_fd = hold_locked_index(lock, 1);
670 refresh_cache(REFRESH_QUIET);
671 if (active_cache_changed &&
672 (write_cache(index_fd, active_cache, active_nr) ||
673 commit_locked_index(lock)))
bacec478 674 return error(_("Unable to write index."));
668f26ff 675 rollback_lock_file(lock);
1c7b76be 676
18668f53 677 if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
3f9083cd 678 int clean, x;
18668f53
MV
679 struct commit *result;
680 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
681 int index_fd;
682 struct commit_list *reversed = NULL;
683 struct merge_options o;
3f9083cd 684 struct commit_list *j;
18668f53
MV
685
686 if (remoteheads->next) {
bacec478 687 error(_("Not handling anything other than two heads merge."));
18668f53
MV
688 return 2;
689 }
690
691 init_merge_options(&o);
692 if (!strcmp(strategy, "subtree"))
85e51b78 693 o.subtree_shift = "";
8cc5b290 694
7610fa57 695 o.renormalize = option_renormalize;
99bfc669
JK
696 o.show_rename_progress =
697 show_progress == -1 ? isatty(2) : show_progress;
7610fa57 698
635a7bb1
JN
699 for (x = 0; x < xopts_nr; x++)
700 if (parse_merge_opt(&o, xopts[x]))
bacec478 701 die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
18668f53
MV
702
703 o.branch1 = head_arg;
704 o.branch2 = remoteheads->item->util;
705
706 for (j = common; j; j = j->next)
707 commit_list_insert(j->item, &reversed);
708
709 index_fd = hold_locked_index(lock, 1);
710 clean = merge_recursive(&o, lookup_commit(head),
711 remoteheads->item, reversed, &result);
712 if (active_cache_changed &&
713 (write_cache(index_fd, active_cache, active_nr) ||
714 commit_locked_index(lock)))
bacec478 715 die (_("unable to write %s"), get_index_file());
42716660 716 rollback_lock_file(lock);
18668f53
MV
717 return clean ? 0 : 1;
718 } else {
67ac1e1d
JN
719 return try_merge_command(strategy, xopts_nr, xopts,
720 common, head_arg, remoteheads);
18668f53 721 }
1c7b76be
MV
722}
723
724static void count_diff_files(struct diff_queue_struct *q,
725 struct diff_options *opt, void *data)
726{
727 int *count = data;
728
729 (*count) += q->nr;
730}
731
732static int count_unmerged_entries(void)
733{
1c7b76be
MV
734 int i, ret = 0;
735
be6ff819
JH
736 for (i = 0; i < active_nr; i++)
737 if (ce_stage(active_cache[i]))
1c7b76be
MV
738 ret++;
739
740 return ret;
741}
742
cac42b26 743int checkout_fast_forward(const unsigned char *head, const unsigned char *remote)
1c7b76be
MV
744{
745 struct tree *trees[MAX_UNPACK_TREES];
746 struct unpack_trees_options opts;
747 struct tree_desc t[MAX_UNPACK_TREES];
748 int i, fd, nr_trees = 0;
749 struct dir_struct dir;
750 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
751
9ca8f607 752 refresh_cache(REFRESH_QUIET);
1c7b76be
MV
753
754 fd = hold_locked_index(lock_file, 1);
755
756 memset(&trees, 0, sizeof(trees));
757 memset(&opts, 0, sizeof(opts));
758 memset(&t, 0, sizeof(t));
5d2299de 759 memset(&dir, 0, sizeof(dir));
7c4c97c0 760 dir.flags |= DIR_SHOW_IGNORED;
1c7b76be
MV
761 dir.exclude_per_dir = ".gitignore";
762 opts.dir = &dir;
763
764 opts.head_idx = 1;
765 opts.src_index = &the_index;
766 opts.dst_index = &the_index;
767 opts.update = 1;
768 opts.verbose_update = 1;
769 opts.merge = 1;
770 opts.fn = twoway_merge;
e294030f 771 setup_unpack_trees_porcelain(&opts, "merge");
1c7b76be
MV
772
773 trees[nr_trees] = parse_tree_indirect(head);
774 if (!trees[nr_trees++])
775 return -1;
776 trees[nr_trees] = parse_tree_indirect(remote);
777 if (!trees[nr_trees++])
778 return -1;
779 for (i = 0; i < nr_trees; i++) {
780 parse_tree(trees[i]);
781 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
782 }
783 if (unpack_trees(nr_trees, t, &opts))
784 return -1;
785 if (write_cache(fd, active_cache, active_nr) ||
786 commit_locked_index(lock_file))
bacec478 787 die(_("unable to write new index file"));
1c7b76be
MV
788 return 0;
789}
790
791static void split_merge_strategies(const char *string, struct strategy **list,
792 int *nr, int *alloc)
793{
794 char *p, *q, *buf;
795
796 if (!string)
797 return;
798
799 buf = xstrdup(string);
800 q = buf;
801 for (;;) {
802 p = strchr(q, ' ');
803 if (!p) {
804 ALLOC_GROW(*list, *nr + 1, *alloc);
805 (*list)[(*nr)++].name = xstrdup(q);
806 free(buf);
807 return;
808 } else {
809 *p = '\0';
810 ALLOC_GROW(*list, *nr + 1, *alloc);
811 (*list)[(*nr)++].name = xstrdup(q);
812 q = ++p;
813 }
814 }
815}
816
817static void add_strategies(const char *string, unsigned attr)
818{
819 struct strategy *list = NULL;
820 int list_alloc = 0, list_nr = 0, i;
821
822 memset(&list, 0, sizeof(list));
823 split_merge_strategies(string, &list, &list_nr, &list_alloc);
1719b5e4
MV
824 if (list) {
825 for (i = 0; i < list_nr; i++)
826 append_strategy(get_strategy(list[i].name));
1c7b76be
MV
827 return;
828 }
829 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
830 if (all_strategy[i].attr & attr)
831 append_strategy(&all_strategy[i]);
832
833}
834
65969d43
JS
835static void write_merge_msg(void)
836{
837 int fd = open(git_path("MERGE_MSG"), O_WRONLY | O_CREAT, 0666);
838 if (fd < 0)
6c80cd29 839 die_errno(_("Could not open '%s' for writing"),
65969d43
JS
840 git_path("MERGE_MSG"));
841 if (write_in_full(fd, merge_msg.buf, merge_msg.len) != merge_msg.len)
6c80cd29 842 die_errno(_("Could not write to '%s'"), git_path("MERGE_MSG"));
65969d43
JS
843 close(fd);
844}
845
846static void read_merge_msg(void)
847{
848 strbuf_reset(&merge_msg);
849 if (strbuf_read_file(&merge_msg, git_path("MERGE_MSG"), 0) < 0)
650ed9db 850 die_errno(_("Could not read from '%s'"), git_path("MERGE_MSG"));
65969d43
JS
851}
852
853static void run_prepare_commit_msg(void)
854{
855 write_merge_msg();
856 run_hook(get_index_file(), "prepare-commit-msg",
857 git_path("MERGE_MSG"), "merge", NULL, NULL);
858 read_merge_msg();
859}
860
1c7b76be
MV
861static int merge_trivial(void)
862{
863 unsigned char result_tree[20], result_commit[20];
36e40535 864 struct commit_list *parent = xmalloc(sizeof(*parent));
1c7b76be
MV
865
866 write_tree_trivial(result_tree);
157efde1 867 printf(_("Wonderful.\n"));
446247db 868 parent->item = lookup_commit(head);
36e40535 869 parent->next = xmalloc(sizeof(*parent->next));
446247db
JH
870 parent->next->item = remoteheads->item;
871 parent->next->next = NULL;
65969d43 872 run_prepare_commit_msg();
ee20a129 873 commit_tree(merge_msg.buf, result_tree, parent, result_commit, NULL);
1c7b76be
MV
874 finish(result_commit, "In-index merge");
875 drop_save();
876 return 0;
877}
878
879static int finish_automerge(struct commit_list *common,
880 unsigned char *result_tree,
881 const char *wt_strategy)
882{
883 struct commit_list *parents = NULL, *j;
884 struct strbuf buf = STRBUF_INIT;
885 unsigned char result_commit[20];
886
887 free_commit_list(common);
888 if (allow_fast_forward) {
889 parents = remoteheads;
890 commit_list_insert(lookup_commit(head), &parents);
891 parents = reduce_heads(parents);
892 } else {
893 struct commit_list **pptr = &parents;
894
895 pptr = &commit_list_insert(lookup_commit(head),
896 pptr)->next;
897 for (j = remoteheads; j; j = j->next)
898 pptr = &commit_list_insert(j->item, pptr)->next;
899 }
900 free_commit_list(remoteheads);
901 strbuf_addch(&merge_msg, '\n');
65969d43 902 run_prepare_commit_msg();
ee20a129 903 commit_tree(merge_msg.buf, result_tree, parents, result_commit, NULL);
f23101bf 904 strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
1c7b76be
MV
905 finish(result_commit, buf.buf);
906 strbuf_release(&buf);
907 drop_save();
908 return 0;
909}
910
7610fa57 911static int suggest_conflicts(int renormalizing)
1c7b76be
MV
912{
913 FILE *fp;
914 int pos;
915
916 fp = fopen(git_path("MERGE_MSG"), "a");
917 if (!fp)
bacec478 918 die_errno(_("Could not open '%s' for writing"),
0721c314 919 git_path("MERGE_MSG"));
1c7b76be
MV
920 fprintf(fp, "\nConflicts:\n");
921 for (pos = 0; pos < active_nr; pos++) {
922 struct cache_entry *ce = active_cache[pos];
923
924 if (ce_stage(ce)) {
925 fprintf(fp, "\t%s\n", ce->name);
926 while (pos + 1 < active_nr &&
927 !strcmp(ce->name,
928 active_cache[pos + 1]->name))
929 pos++;
930 }
931 }
932 fclose(fp);
cb6020bb 933 rerere(allow_rerere_auto);
bacec478
ÆAB
934 printf(_("Automatic merge failed; "
935 "fix conflicts and then commit the result.\n"));
1c7b76be
MV
936 return 1;
937}
938
939static struct commit *is_old_style_invocation(int argc, const char **argv)
940{
941 struct commit *second_token = NULL;
76bf488e 942 if (argc > 2) {
1c7b76be
MV
943 unsigned char second_sha1[20];
944
945 if (get_sha1(argv[1], second_sha1))
946 return NULL;
947 second_token = lookup_commit_reference_gently(second_sha1, 0);
948 if (!second_token)
bacec478 949 die(_("'%s' is not a commit"), argv[1]);
1c7b76be
MV
950 if (hashcmp(second_token->object.sha1, head))
951 return NULL;
952 }
953 return second_token;
954}
955
956static int evaluate_result(void)
957{
958 int cnt = 0;
959 struct rev_info rev;
960
1c7b76be
MV
961 /* Check how many files differ. */
962 init_revisions(&rev, "");
963 setup_revisions(0, NULL, &rev, NULL);
964 rev.diffopt.output_format |=
965 DIFF_FORMAT_CALLBACK;
966 rev.diffopt.format_callback = count_diff_files;
967 rev.diffopt.format_callback_data = &cnt;
968 run_diff_files(&rev, 0);
969
970 /*
971 * Check how many unmerged entries are
972 * there.
973 */
974 cnt += count_unmerged_entries();
975
976 return cnt;
977}
978
93e535a5
JH
979/*
980 * Pretend as if the user told us to merge with the tracking
981 * branch we have for the upstream of the current branch
982 */
983static int setup_with_upstream(const char ***argv)
984{
985 struct branch *branch = branch_get(NULL);
986 int i;
987 const char **args;
988
989 if (!branch)
c7f426d4 990 die(_("No current branch."));
93e535a5 991 if (!branch->remote)
c7f426d4 992 die(_("No remote for the current branch."));
93e535a5 993 if (!branch->merge_nr)
c7f426d4 994 die(_("No default upstream defined for the current branch."));
93e535a5
JH
995
996 args = xcalloc(branch->merge_nr + 1, sizeof(char *));
997 for (i = 0; i < branch->merge_nr; i++) {
998 if (!branch->merge[i]->dst)
c7f426d4 999 die(_("No remote tracking branch for %s from %s"),
93e535a5
JH
1000 branch->merge[i]->src, branch->remote_name);
1001 args[i] = branch->merge[i]->dst;
1002 }
1003 args[i] = NULL;
1004 *argv = args;
1005 return i;
1006}
1007
1c7b76be
MV
1008int cmd_merge(int argc, const char **argv, const char *prefix)
1009{
1010 unsigned char result_tree[20];
f285a2d7 1011 struct strbuf buf = STRBUF_INIT;
1c7b76be
MV
1012 const char *head_arg;
1013 int flag, head_invalid = 0, i;
1014 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
1015 struct commit_list *common = NULL;
1016 const char *best_strategy = NULL, *wt_strategy = NULL;
1017 struct commit_list **remotes = &remoteheads;
1018
da53eec6
NTND
1019 if (argc == 2 && !strcmp(argv[1], "-h"))
1020 usage_with_options(builtin_merge_usage, builtin_merge_options);
1c7b76be
MV
1021
1022 /*
1023 * Check if we are _not_ on a detached HEAD, i.e. if there is a
1024 * current branch.
1025 */
1026 branch = resolve_ref("HEAD", head, 0, &flag);
1027 if (branch && !prefixcmp(branch, "refs/heads/"))
1028 branch += 11;
1029 if (is_null_sha1(head))
1030 head_invalid = 1;
1031
1032 git_config(git_merge_config, NULL);
1033
0d8fc3ef
JH
1034 if (branch_mergeoptions)
1035 parse_branch_merge_options(branch_mergeoptions);
37782920 1036 argc = parse_options(argc, argv, prefix, builtin_merge_options,
1c7b76be 1037 builtin_merge_usage, 0);
2a22c1b3 1038
99bfc669
JK
1039 if (verbosity < 0 && show_progress == -1)
1040 show_progress = 0;
1041
35d2fffd
JH
1042 if (abort_current_merge) {
1043 int nargc = 2;
1044 const char *nargv[] = {"reset", "--merge", NULL};
1045
1046 if (!file_exists(git_path("MERGE_HEAD")))
bacec478 1047 die(_("There is no merge to abort (MERGE_HEAD missing)."));
35d2fffd
JH
1048
1049 /* Invoke 'git reset --merge' */
1050 return cmd_reset(nargc, nargv, prefix);
1051 }
1052
2a22c1b3
JH
1053 if (read_cache_unmerged())
1054 die_resolve_conflict("merge");
1055
1056 if (file_exists(git_path("MERGE_HEAD"))) {
1057 /*
1058 * There is no unmerged entry, don't advise 'git
1059 * add/rm <file>', just 'git commit'.
1060 */
1061 if (advice_resolve_conflict)
bacec478
ÆAB
1062 die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
1063 "Please, commit your changes before you can merge."));
2a22c1b3 1064 else
bacec478 1065 die(_("You have not concluded your merge (MERGE_HEAD exists)."));
2a22c1b3 1066 }
d7e5c0cb
JS
1067 if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
1068 if (advice_resolve_conflict)
f68f1801
ÆAB
1069 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
1070 "Please, commit your changes before you can merge."));
d7e5c0cb 1071 else
f68f1801 1072 die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
2a22c1b3
JH
1073 }
1074 resolve_undo_clear();
1075
7f87aff2
TA
1076 if (verbosity < 0)
1077 show_diffstat = 0;
1c7b76be
MV
1078
1079 if (squash) {
1080 if (!allow_fast_forward)
bacec478 1081 die(_("You cannot combine --squash with --no-ff."));
1c7b76be
MV
1082 option_commit = 0;
1083 }
1084
13474835 1085 if (!allow_fast_forward && fast_forward_only)
bacec478 1086 die(_("You cannot combine --no-ff with --ff-only."));
13474835 1087
4e8115ff
JH
1088 if (!abort_current_merge) {
1089 if (!argc && default_to_upstream)
1090 argc = setup_with_upstream(&argv);
1091 else if (argc == 1 && !strcmp(argv[0], "-"))
1092 argv[0] = "@{-1}";
1093 }
1c7b76be
MV
1094 if (!argc)
1095 usage_with_options(builtin_merge_usage,
1096 builtin_merge_options);
1097
1098 /*
1099 * This could be traditional "merge <msg> HEAD <commit>..." and
1100 * the way we can tell it is to see if the second token is HEAD,
1101 * but some people might have misused the interface and used a
1102 * committish that is the same as HEAD there instead.
1103 * Traditional format never would have "-m" so it is an
1104 * additional safety measure to check for it.
1105 */
1c7b76be
MV
1106
1107 if (!have_message && is_old_style_invocation(argc, argv)) {
1108 strbuf_addstr(&merge_msg, argv[0]);
1109 head_arg = argv[1];
1110 argv += 2;
1111 argc -= 2;
1112 } else if (head_invalid) {
1113 struct object *remote_head;
1114 /*
1115 * If the merged head is a valid one there is no reason
1116 * to forbid "git merge" into a branch yet to be born.
1117 * We do the same for "git pull".
1118 */
1119 if (argc != 1)
bacec478
ÆAB
1120 die(_("Can merge only exactly one commit into "
1121 "empty head"));
4be636f4 1122 if (squash)
bacec478 1123 die(_("Squash commit into empty head not supported yet"));
4be636f4 1124 if (!allow_fast_forward)
bacec478
ÆAB
1125 die(_("Non-fast-forward commit does not make sense into "
1126 "an empty head"));
1c7b76be
MV
1127 remote_head = peel_to_type(argv[0], 0, NULL, OBJ_COMMIT);
1128 if (!remote_head)
bacec478 1129 die(_("%s - not something we can merge"), argv[0]);
97b1b4f3 1130 read_empty(remote_head->sha1, 0);
1c7b76be
MV
1131 update_ref("initial pull", "HEAD", remote_head->sha1, NULL, 0,
1132 DIE_ON_ERR);
1c7b76be
MV
1133 return 0;
1134 } else {
97d45bcb 1135 struct strbuf merge_names = STRBUF_INIT;
1c7b76be
MV
1136
1137 /* We are invoked directly as the first-class UI. */
1138 head_arg = "HEAD";
1139
1140 /*
1141 * All the rest are the commits being merged;
1142 * prepare the standard merge summary message to
1143 * be appended to the given message. If remote
1144 * is invalid we will die later in the common
1145 * codepath so we discard the error in this
1146 * loop.
1147 */
f0ecac2b
TRC
1148 for (i = 0; i < argc; i++)
1149 merge_name(argv[i], &merge_names);
1150
96e9420c 1151 if (!have_message || shortlog_len) {
1876166a 1152 fmt_merge_msg(&merge_names, &merge_msg, !have_message,
96e9420c 1153 shortlog_len);
1876166a
RR
1154 if (merge_msg.len)
1155 strbuf_setlen(&merge_msg, merge_msg.len - 1);
1156 }
1c7b76be
MV
1157 }
1158
1159 if (head_invalid || !argc)
1160 usage_with_options(builtin_merge_usage,
1161 builtin_merge_options);
1162
1163 strbuf_addstr(&buf, "merge");
1164 for (i = 0; i < argc; i++)
1165 strbuf_addf(&buf, " %s", argv[i]);
1166 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
1167 strbuf_reset(&buf);
1168
1169 for (i = 0; i < argc; i++) {
1170 struct object *o;
18668f53 1171 struct commit *commit;
1c7b76be
MV
1172
1173 o = peel_to_type(argv[i], 0, NULL, OBJ_COMMIT);
1174 if (!o)
bacec478 1175 die(_("%s - not something we can merge"), argv[i]);
18668f53
MV
1176 commit = lookup_commit(o->sha1);
1177 commit->util = (void *)argv[i];
1178 remotes = &commit_list_insert(commit, remotes)->next;
1c7b76be
MV
1179
1180 strbuf_addf(&buf, "GITHEAD_%s", sha1_to_hex(o->sha1));
1181 setenv(buf.buf, argv[i], 1);
1182 strbuf_reset(&buf);
1183 }
1184
1185 if (!use_strategies) {
1186 if (!remoteheads->next)
1187 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
1188 else
1189 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
1190 }
1191
1192 for (i = 0; i < use_strategies_nr; i++) {
1193 if (use_strategies[i]->attr & NO_FAST_FORWARD)
1194 allow_fast_forward = 0;
1195 if (use_strategies[i]->attr & NO_TRIVIAL)
1196 allow_trivial = 0;
1197 }
1198
1199 if (!remoteheads->next)
1200 common = get_merge_bases(lookup_commit(head),
1201 remoteheads->item, 1);
1202 else {
1203 struct commit_list *list = remoteheads;
1204 commit_list_insert(lookup_commit(head), &list);
1205 common = get_octopus_merge_bases(list);
1206 free(list);
1207 }
1208
1209 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head, NULL, 0,
1210 DIE_ON_ERR);
1211
1212 if (!common)
1213 ; /* No common ancestors found. We need a real merge. */
1214 else if (!remoteheads->next && !common->next &&
1215 common->item == remoteheads->item) {
1216 /*
1217 * If head can reach all the merge then we are up to date.
1218 * but first the most common case of merging one remote.
1219 */
1220 finish_up_to_date("Already up-to-date.");
1221 return 0;
1222 } else if (allow_fast_forward && !remoteheads->next &&
1223 !common->next &&
1224 !hashcmp(common->item->object.sha1, head)) {
1225 /* Again the most common case of merging one remote. */
f285a2d7 1226 struct strbuf msg = STRBUF_INIT;
1c7b76be
MV
1227 struct object *o;
1228 char hex[41];
1229
1230 strcpy(hex, find_unique_abbrev(head, DEFAULT_ABBREV));
1231
7f87aff2 1232 if (verbosity >= 0)
2ceb61e0 1233 printf(_("Updating %s..%s\n"),
7f87aff2
TA
1234 hex,
1235 find_unique_abbrev(remoteheads->item->object.sha1,
1236 DEFAULT_ABBREV));
a75d7b54 1237 strbuf_addstr(&msg, "Fast-forward");
1c7b76be
MV
1238 if (have_message)
1239 strbuf_addstr(&msg,
1240 " (no commit created; -m option ignored)");
1241 o = peel_to_type(sha1_to_hex(remoteheads->item->object.sha1),
1242 0, NULL, OBJ_COMMIT);
1243 if (!o)
1244 return 1;
1245
1246 if (checkout_fast_forward(head, remoteheads->item->object.sha1))
1247 return 1;
1248
1249 finish(o->sha1, msg.buf);
1250 drop_save();
1251 return 0;
1252 } else if (!remoteheads->next && common->next)
1253 ;
1254 /*
a75d7b54 1255 * We are not doing octopus and not fast-forward. Need
1c7b76be
MV
1256 * a real merge.
1257 */
1258 else if (!remoteheads->next && !common->next && option_commit) {
1259 /*
a75d7b54 1260 * We are not doing octopus, not fast-forward, and have
1c7b76be
MV
1261 * only one common.
1262 */
1263 refresh_cache(REFRESH_QUIET);
13474835 1264 if (allow_trivial && !fast_forward_only) {
1c7b76be
MV
1265 /* See if it is really trivial. */
1266 git_committer_info(IDENT_ERROR_ON_NO_NAME);
bacec478 1267 printf(_("Trying really trivial in-index merge...\n"));
1c7b76be
MV
1268 if (!read_tree_trivial(common->item->object.sha1,
1269 head, remoteheads->item->object.sha1))
1270 return merge_trivial();
bacec478 1271 printf(_("Nope.\n"));
1c7b76be
MV
1272 }
1273 } else {
1274 /*
1275 * An octopus. If we can reach all the remote we are up
1276 * to date.
1277 */
1278 int up_to_date = 1;
1279 struct commit_list *j;
1280
1281 for (j = remoteheads; j; j = j->next) {
1282 struct commit_list *common_one;
1283
1284 /*
1285 * Here we *have* to calculate the individual
1286 * merge_bases again, otherwise "git merge HEAD^
1287 * HEAD^^" would be missed.
1288 */
1289 common_one = get_merge_bases(lookup_commit(head),
1290 j->item, 1);
1291 if (hashcmp(common_one->item->object.sha1,
1292 j->item->object.sha1)) {
1293 up_to_date = 0;
1294 break;
1295 }
1296 }
1297 if (up_to_date) {
1298 finish_up_to_date("Already up-to-date. Yeeah!");
1299 return 0;
1300 }
1301 }
1302
13474835 1303 if (fast_forward_only)
bacec478 1304 die(_("Not possible to fast-forward, aborting."));
13474835 1305
1c7b76be
MV
1306 /* We are going to make a new commit. */
1307 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1308
1309 /*
1310 * At this point, we need a real merge. No matter what strategy
1311 * we use, it would operate on the index, possibly affecting the
1312 * working tree, and when resolved cleanly, have the desired
1313 * tree in the index -- this means that the index must be in
1314 * sync with the head commit. The strategies are responsible
1315 * to ensure this.
1316 */
1317 if (use_strategies_nr != 1) {
1318 /*
1319 * Stash away the local changes so that we can try more
1320 * than one.
1321 */
1322 save_state();
1323 } else {
1324 memcpy(stash, null_sha1, 20);
1325 }
1326
1327 for (i = 0; i < use_strategies_nr; i++) {
1328 int ret;
1329 if (i) {
bacec478 1330 printf(_("Rewinding the tree to pristine...\n"));
1c7b76be
MV
1331 restore_state();
1332 }
1333 if (use_strategies_nr != 1)
bacec478 1334 printf(_("Trying merge strategy %s...\n"),
1c7b76be
MV
1335 use_strategies[i]->name);
1336 /*
1337 * Remember which strategy left the state in the working
1338 * tree.
1339 */
1340 wt_strategy = use_strategies[i]->name;
1341
1342 ret = try_merge_strategy(use_strategies[i]->name,
1343 common, head_arg);
1344 if (!option_commit && !ret) {
1345 merge_was_ok = 1;
1346 /*
1347 * This is necessary here just to avoid writing
1348 * the tree, but later we will *not* exit with
1349 * status code 1 because merge_was_ok is set.
1350 */
1351 ret = 1;
1352 }
1353
1354 if (ret) {
1355 /*
1356 * The backend exits with 1 when conflicts are
1357 * left to be resolved, with 2 when it does not
1358 * handle the given merge at all.
1359 */
1360 if (ret == 1) {
1361 int cnt = evaluate_result();
1362
1363 if (best_cnt <= 0 || cnt <= best_cnt) {
1364 best_strategy = use_strategies[i]->name;
1365 best_cnt = cnt;
1366 }
1367 }
1368 if (merge_was_ok)
1369 break;
1370 else
1371 continue;
1372 }
1373
1374 /* Automerge succeeded. */
1375 write_tree_trivial(result_tree);
1376 automerge_was_ok = 1;
1377 break;
1378 }
1379
1380 /*
1381 * If we have a resulting tree, that means the strategy module
1382 * auto resolved the merge cleanly.
1383 */
1384 if (automerge_was_ok)
1385 return finish_automerge(common, result_tree, wt_strategy);
1386
1387 /*
1388 * Pick the result from the best strategy and have the user fix
1389 * it up.
1390 */
1391 if (!best_strategy) {
1392 restore_state();
1393 if (use_strategies_nr > 1)
1394 fprintf(stderr,
bacec478 1395 _("No merge strategy handled the merge.\n"));
1c7b76be 1396 else
bacec478 1397 fprintf(stderr, _("Merge with strategy %s failed.\n"),
1c7b76be
MV
1398 use_strategies[0]->name);
1399 return 2;
1400 } else if (best_strategy == wt_strategy)
1401 ; /* We already have its result in the working tree. */
1402 else {
bacec478 1403 printf(_("Rewinding the tree to pristine...\n"));
1c7b76be 1404 restore_state();
bacec478 1405 printf(_("Using the %s to prepare resolving by hand.\n"),
1c7b76be
MV
1406 best_strategy);
1407 try_merge_strategy(best_strategy, common, head_arg);
1408 }
1409
1410 if (squash)
1411 finish(NULL, NULL);
1412 else {
1413 int fd;
1414 struct commit_list *j;
1415
1416 for (j = remoteheads; j; j = j->next)
1417 strbuf_addf(&buf, "%s\n",
1418 sha1_to_hex(j->item->object.sha1));
1419 fd = open(git_path("MERGE_HEAD"), O_WRONLY | O_CREAT, 0666);
1420 if (fd < 0)
bacec478 1421 die_errno(_("Could not open '%s' for writing"),
0721c314 1422 git_path("MERGE_HEAD"));
1c7b76be 1423 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
bacec478 1424 die_errno(_("Could not write to '%s'"), git_path("MERGE_HEAD"));
1c7b76be
MV
1425 close(fd);
1426 strbuf_addch(&merge_msg, '\n');
65969d43 1427 write_merge_msg();
cf10f9fd
MV
1428 fd = open(git_path("MERGE_MODE"), O_WRONLY | O_CREAT | O_TRUNC, 0666);
1429 if (fd < 0)
bacec478 1430 die_errno(_("Could not open '%s' for writing"),
0721c314 1431 git_path("MERGE_MODE"));
cf10f9fd
MV
1432 strbuf_reset(&buf);
1433 if (!allow_fast_forward)
1434 strbuf_addf(&buf, "no-ff");
1435 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
bacec478 1436 die_errno(_("Could not write to '%s'"), git_path("MERGE_MODE"));
cf10f9fd 1437 close(fd);
1c7b76be
MV
1438 }
1439
1440 if (merge_was_ok) {
bacec478
ÆAB
1441 fprintf(stderr, _("Automatic merge went well; "
1442 "stopped before committing as requested\n"));
1c7b76be
MV
1443 return 0;
1444 } else
7610fa57 1445 return suggest_conflicts(option_renormalize);
1c7b76be 1446}