builtin-merge: fix a typo in an error message
[git/git.git] / builtin-merge.c
CommitLineData
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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"
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25
26#define DEFAULT_TWOHEAD (1<<0)
27#define DEFAULT_OCTOPUS (1<<1)
28#define NO_FAST_FORWARD (1<<2)
29#define NO_TRIVIAL (1<<3)
30
31struct strategy {
32 const char *name;
33 unsigned attr;
34};
35
36static const char * const builtin_merge_usage[] = {
37 "git-merge [options] <remote>...",
38 "git-merge [options] <msg> HEAD <remote>",
39 NULL
40};
41
42static int show_diffstat = 1, option_log, squash;
43static int option_commit = 1, allow_fast_forward = 1;
44static int allow_trivial = 1, have_message;
45static struct strbuf merge_msg;
46static struct commit_list *remoteheads;
47static unsigned char head[20], stash[20];
48static struct strategy **use_strategies;
49static size_t use_strategies_nr, use_strategies_alloc;
50static const char *branch;
51
52static struct strategy all_strategy[] = {
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53 { "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
54 { "octopus", DEFAULT_OCTOPUS },
55 { "resolve", 0 },
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56 { "ours", NO_FAST_FORWARD | NO_TRIVIAL },
57 { "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
58};
59
60static const char *pull_twohead, *pull_octopus;
61
62static int option_parse_message(const struct option *opt,
63 const char *arg, int unset)
64{
65 struct strbuf *buf = opt->value;
66
67 if (unset)
68 strbuf_setlen(buf, 0);
74f5b7fb 69 else if (arg) {
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70 strbuf_addf(buf, "%s\n\n", arg);
71 have_message = 1;
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72 } else
73 return error("switch `m' requires a value");
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74 return 0;
75}
76
77static struct strategy *get_strategy(const char *name)
78{
79 int i;
1719b5e4 80 struct strbuf err;
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81
82 if (!name)
83 return NULL;
84
85 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
86 if (!strcmp(name, all_strategy[i].name))
87 return &all_strategy[i];
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88
89 strbuf_init(&err, 0);
90 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
91 strbuf_addf(&err, " %s", all_strategy[i].name);
92 fprintf(stderr, "Could not find merge strategy '%s'.\n", name);
93 fprintf(stderr, "Available strategies are:%s.\n", err.buf);
94 exit(1);
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95}
96
97static void append_strategy(struct strategy *s)
98{
99 ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
100 use_strategies[use_strategies_nr++] = s;
101}
102
103static int option_parse_strategy(const struct option *opt,
104 const char *name, int unset)
105{
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106 if (unset)
107 return 0;
108
1719b5e4 109 append_strategy(get_strategy(name));
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110 return 0;
111}
112
113static int option_parse_n(const struct option *opt,
114 const char *arg, int unset)
115{
116 show_diffstat = unset;
117 return 0;
118}
119
120static struct option builtin_merge_options[] = {
121 { OPTION_CALLBACK, 'n', NULL, NULL, NULL,
122 "do not show a diffstat at the end of the merge",
123 PARSE_OPT_NOARG, option_parse_n },
124 OPT_BOOLEAN(0, "stat", &show_diffstat,
125 "show a diffstat at the end of the merge"),
126 OPT_BOOLEAN(0, "summary", &show_diffstat, "(synonym to --stat)"),
127 OPT_BOOLEAN(0, "log", &option_log,
128 "add list of one-line log to merge commit message"),
129 OPT_BOOLEAN(0, "squash", &squash,
130 "create a single commit instead of doing a merge"),
131 OPT_BOOLEAN(0, "commit", &option_commit,
132 "perform a commit if the merge succeeds (default)"),
133 OPT_BOOLEAN(0, "ff", &allow_fast_forward,
134 "allow fast forward (default)"),
135 OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
136 "merge strategy to use", option_parse_strategy),
137 OPT_CALLBACK('m', "message", &merge_msg, "message",
138 "message to be used for the merge commit (if any)",
139 option_parse_message),
140 OPT_END()
141};
142
143/* Cleans up metadata that is uninteresting after a succeeded merge. */
144static void drop_save(void)
145{
146 unlink(git_path("MERGE_HEAD"));
147 unlink(git_path("MERGE_MSG"));
148}
149
150static void save_state(void)
151{
152 int len;
153 struct child_process cp;
154 struct strbuf buffer = STRBUF_INIT;
155 const char *argv[] = {"stash", "create", NULL};
156
157 memset(&cp, 0, sizeof(cp));
158 cp.argv = argv;
159 cp.out = -1;
160 cp.git_cmd = 1;
161
162 if (start_command(&cp))
163 die("could not run stash.");
164 len = strbuf_read(&buffer, cp.out, 1024);
165 close(cp.out);
166
167 if (finish_command(&cp) || len < 0)
168 die("stash failed");
169 else if (!len)
170 return;
171 strbuf_setlen(&buffer, buffer.len-1);
172 if (get_sha1(buffer.buf, stash))
173 die("not a valid object: %s", buffer.buf);
174}
175
176static void reset_hard(unsigned const char *sha1, int verbose)
177{
178 int i = 0;
179 const char *args[6];
180
181 args[i++] = "read-tree";
182 if (verbose)
183 args[i++] = "-v";
184 args[i++] = "--reset";
185 args[i++] = "-u";
186 args[i++] = sha1_to_hex(sha1);
187 args[i] = NULL;
188
189 if (run_command_v_opt(args, RUN_GIT_CMD))
190 die("read-tree failed");
191}
192
193static void restore_state(void)
194{
195 struct strbuf sb;
196 const char *args[] = { "stash", "apply", NULL, NULL };
197
198 if (is_null_sha1(stash))
199 return;
200
201 reset_hard(head, 1);
202
203 strbuf_init(&sb, 0);
204 args[2] = sha1_to_hex(stash);
205
206 /*
207 * It is OK to ignore error here, for example when there was
208 * nothing to restore.
209 */
210 run_command_v_opt(args, RUN_GIT_CMD);
211
212 strbuf_release(&sb);
213 refresh_cache(REFRESH_QUIET);
214}
215
216/* This is called when no merge was necessary. */
217static void finish_up_to_date(const char *msg)
218{
219 printf("%s%s\n", squash ? " (nothing to squash)" : "", msg);
220 drop_save();
221}
222
223static void squash_message(void)
224{
225 struct rev_info rev;
226 struct commit *commit;
227 struct strbuf out;
228 struct commit_list *j;
229 int fd;
230
231 printf("Squash commit -- not updating HEAD\n");
232 fd = open(git_path("SQUASH_MSG"), O_WRONLY | O_CREAT, 0666);
233 if (fd < 0)
234 die("Could not write to %s", git_path("SQUASH_MSG"));
235
236 init_revisions(&rev, NULL);
237 rev.ignore_merges = 1;
238 rev.commit_format = CMIT_FMT_MEDIUM;
239
240 commit = lookup_commit(head);
241 commit->object.flags |= UNINTERESTING;
242 add_pending_object(&rev, &commit->object, NULL);
243
244 for (j = remoteheads; j; j = j->next)
245 add_pending_object(&rev, &j->item->object, NULL);
246
247 setup_revisions(0, NULL, &rev, NULL);
248 if (prepare_revision_walk(&rev))
249 die("revision walk setup failed");
250
251 strbuf_init(&out, 0);
252 strbuf_addstr(&out, "Squashed commit of the following:\n");
253 while ((commit = get_revision(&rev)) != NULL) {
254 strbuf_addch(&out, '\n');
255 strbuf_addf(&out, "commit %s\n",
256 sha1_to_hex(commit->object.sha1));
257 pretty_print_commit(rev.commit_format, commit, &out, rev.abbrev,
258 NULL, NULL, rev.date_mode, 0);
259 }
260 write(fd, out.buf, out.len);
261 close(fd);
262 strbuf_release(&out);
263}
264
265static int run_hook(const char *name)
266{
267 struct child_process hook;
268 const char *argv[3], *env[2];
269 char index[PATH_MAX];
270
271 argv[0] = git_path("hooks/%s", name);
272 if (access(argv[0], X_OK) < 0)
273 return 0;
274
275 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", get_index_file());
276 env[0] = index;
277 env[1] = NULL;
278
279 if (squash)
280 argv[1] = "1";
281 else
282 argv[1] = "0";
283 argv[2] = NULL;
284
285 memset(&hook, 0, sizeof(hook));
286 hook.argv = argv;
287 hook.no_stdin = 1;
288 hook.stdout_to_stderr = 1;
289 hook.env = env;
290
291 return run_command(&hook);
292}
293
294static void finish(const unsigned char *new_head, const char *msg)
295{
296 struct strbuf reflog_message;
297
298 strbuf_init(&reflog_message, 0);
299 if (!msg)
300 strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
301 else {
302 printf("%s\n", msg);
303 strbuf_addf(&reflog_message, "%s: %s",
304 getenv("GIT_REFLOG_ACTION"), msg);
305 }
306 if (squash) {
307 squash_message();
308 } else {
309 if (!merge_msg.len)
310 printf("No merge message -- not updating HEAD\n");
311 else {
312 const char *argv_gc_auto[] = { "gc", "--auto", NULL };
313 update_ref(reflog_message.buf, "HEAD",
314 new_head, head, 0,
315 DIE_ON_ERR);
316 /*
317 * We ignore errors in 'gc --auto', since the
318 * user should see them.
319 */
320 run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
321 }
322 }
323 if (new_head && show_diffstat) {
324 struct diff_options opts;
325 diff_setup(&opts);
326 opts.output_format |=
327 DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
328 opts.detect_rename = DIFF_DETECT_RENAME;
329 if (diff_use_color_default > 0)
330 DIFF_OPT_SET(&opts, COLOR_DIFF);
331 if (diff_setup_done(&opts) < 0)
332 die("diff_setup_done failed");
333 diff_tree_sha1(head, new_head, "", &opts);
334 diffcore_std(&opts);
335 diff_flush(&opts);
336 }
337
338 /* Run a post-merge hook */
339 run_hook("post-merge");
340
341 strbuf_release(&reflog_message);
342}
343
344/* Get the name for the merge commit's message. */
345static void merge_name(const char *remote, struct strbuf *msg)
346{
347 struct object *remote_head;
348 unsigned char branch_head[20], buf_sha[20];
349 struct strbuf buf;
350 const char *ptr;
351 int len, early;
352
353 memset(branch_head, 0, sizeof(branch_head));
354 remote_head = peel_to_type(remote, 0, NULL, OBJ_COMMIT);
355 if (!remote_head)
356 die("'%s' does not point to a commit", remote);
357
358 strbuf_init(&buf, 0);
359 strbuf_addstr(&buf, "refs/heads/");
360 strbuf_addstr(&buf, remote);
361 resolve_ref(buf.buf, branch_head, 0, 0);
362
363 if (!hashcmp(remote_head->sha1, branch_head)) {
364 strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
365 sha1_to_hex(branch_head), remote);
366 return;
367 }
368
369 /* See if remote matches <name>^^^.. or <name>~<number> */
370 for (len = 0, ptr = remote + strlen(remote);
371 remote < ptr && ptr[-1] == '^';
372 ptr--)
373 len++;
374 if (len)
375 early = 1;
376 else {
377 early = 0;
378 ptr = strrchr(remote, '~');
379 if (ptr) {
380 int seen_nonzero = 0;
381
382 len++; /* count ~ */
383 while (*++ptr && isdigit(*ptr)) {
384 seen_nonzero |= (*ptr != '0');
385 len++;
386 }
387 if (*ptr)
388 len = 0; /* not ...~<number> */
389 else if (seen_nonzero)
390 early = 1;
391 else if (len == 1)
392 early = 1; /* "name~" is "name~1"! */
393 }
394 }
395 if (len) {
396 struct strbuf truname = STRBUF_INIT;
397 strbuf_addstr(&truname, "refs/heads/");
398 strbuf_addstr(&truname, remote);
9b6bf4d5 399 strbuf_setlen(&truname, truname.len - len);
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400 if (resolve_ref(truname.buf, buf_sha, 0, 0)) {
401 strbuf_addf(msg,
402 "%s\t\tbranch '%s'%s of .\n",
403 sha1_to_hex(remote_head->sha1),
9b6bf4d5 404 truname.buf + 11,
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405 (early ? " (early part)" : ""));
406 return;
407 }
408 }
409
410 if (!strcmp(remote, "FETCH_HEAD") &&
411 !access(git_path("FETCH_HEAD"), R_OK)) {
412 FILE *fp;
413 struct strbuf line;
414 char *ptr;
415
416 strbuf_init(&line, 0);
417 fp = fopen(git_path("FETCH_HEAD"), "r");
418 if (!fp)
419 die("could not open %s for reading: %s",
420 git_path("FETCH_HEAD"), strerror(errno));
421 strbuf_getline(&line, fp, '\n');
422 fclose(fp);
423 ptr = strstr(line.buf, "\tnot-for-merge\t");
424 if (ptr)
425 strbuf_remove(&line, ptr-line.buf+1, 13);
426 strbuf_addbuf(msg, &line);
427 strbuf_release(&line);
428 return;
429 }
430 strbuf_addf(msg, "%s\t\tcommit '%s'\n",
431 sha1_to_hex(remote_head->sha1), remote);
432}
433
186458b1 434static int git_merge_config(const char *k, const char *v, void *cb)
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435{
436 if (branch && !prefixcmp(k, "branch.") &&
437 !prefixcmp(k + 7, branch) &&
438 !strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
439 const char **argv;
440 int argc;
441 char *buf;
442
443 buf = xstrdup(v);
444 argc = split_cmdline(buf, &argv);
dc4179f9
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445 if (argc < 0)
446 die("Bad branch.%s.mergeoptions string", branch);
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447 argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
448 memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
449 argc++;
450 parse_options(argc, argv, builtin_merge_options,
451 builtin_merge_usage, 0);
452 free(buf);
453 }
454
455 if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
456 show_diffstat = git_config_bool(k, v);
457 else if (!strcmp(k, "pull.twohead"))
458 return git_config_string(&pull_twohead, k, v);
459 else if (!strcmp(k, "pull.octopus"))
460 return git_config_string(&pull_octopus, k, v);
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461 else if (!strcmp(k, "merge.log") || !strcmp(k, "merge.summary"))
462 option_log = git_config_bool(k, v);
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463 return git_diff_ui_config(k, v, cb);
464}
465
466static int read_tree_trivial(unsigned char *common, unsigned char *head,
467 unsigned char *one)
468{
469 int i, nr_trees = 0;
470 struct tree *trees[MAX_UNPACK_TREES];
471 struct tree_desc t[MAX_UNPACK_TREES];
472 struct unpack_trees_options opts;
473
474 memset(&opts, 0, sizeof(opts));
475 opts.head_idx = 2;
476 opts.src_index = &the_index;
477 opts.dst_index = &the_index;
478 opts.update = 1;
479 opts.verbose_update = 1;
480 opts.trivial_merges_only = 1;
481 opts.merge = 1;
482 trees[nr_trees] = parse_tree_indirect(common);
483 if (!trees[nr_trees++])
484 return -1;
485 trees[nr_trees] = parse_tree_indirect(head);
486 if (!trees[nr_trees++])
487 return -1;
488 trees[nr_trees] = parse_tree_indirect(one);
489 if (!trees[nr_trees++])
490 return -1;
491 opts.fn = threeway_merge;
492 cache_tree_free(&active_cache_tree);
493 for (i = 0; i < nr_trees; i++) {
494 parse_tree(trees[i]);
495 init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
496 }
497 if (unpack_trees(nr_trees, t, &opts))
498 return -1;
499 return 0;
500}
501
502static void write_tree_trivial(unsigned char *sha1)
503{
504 if (write_cache_as_tree(sha1, 0, NULL))
505 die("git write-tree failed to write a tree");
506}
507
508static int try_merge_strategy(const char *strategy, struct commit_list *common,
509 const char *head_arg)
510{
511 const char **args;
512 int i = 0, ret;
513 struct commit_list *j;
514 struct strbuf buf;
515
516 args = xmalloc((4 + commit_list_count(common) +
517 commit_list_count(remoteheads)) * sizeof(char *));
518 strbuf_init(&buf, 0);
519 strbuf_addf(&buf, "merge-%s", strategy);
520 args[i++] = buf.buf;
521 for (j = common; j; j = j->next)
522 args[i++] = xstrdup(sha1_to_hex(j->item->object.sha1));
523 args[i++] = "--";
524 args[i++] = head_arg;
525 for (j = remoteheads; j; j = j->next)
526 args[i++] = xstrdup(sha1_to_hex(j->item->object.sha1));
527 args[i] = NULL;
528 ret = run_command_v_opt(args, RUN_GIT_CMD);
529 strbuf_release(&buf);
530 i = 1;
531 for (j = common; j; j = j->next)
532 free((void *)args[i++]);
533 i += 2;
534 for (j = remoteheads; j; j = j->next)
535 free((void *)args[i++]);
536 free(args);
537 return -ret;
538}
539
540static void count_diff_files(struct diff_queue_struct *q,
541 struct diff_options *opt, void *data)
542{
543 int *count = data;
544
545 (*count) += q->nr;
546}
547
548static int count_unmerged_entries(void)
549{
550 const struct index_state *state = &the_index;
551 int i, ret = 0;
552
553 for (i = 0; i < state->cache_nr; i++)
554 if (ce_stage(state->cache[i]))
555 ret++;
556
557 return ret;
558}
559
560static int checkout_fast_forward(unsigned char *head, unsigned char *remote)
561{
562 struct tree *trees[MAX_UNPACK_TREES];
563 struct unpack_trees_options opts;
564 struct tree_desc t[MAX_UNPACK_TREES];
565 int i, fd, nr_trees = 0;
566 struct dir_struct dir;
567 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
568
9ca8f607 569 refresh_cache(REFRESH_QUIET);
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570
571 fd = hold_locked_index(lock_file, 1);
572
573 memset(&trees, 0, sizeof(trees));
574 memset(&opts, 0, sizeof(opts));
575 memset(&t, 0, sizeof(t));
5d2299de 576 memset(&dir, 0, sizeof(dir));
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577 dir.show_ignored = 1;
578 dir.exclude_per_dir = ".gitignore";
579 opts.dir = &dir;
580
581 opts.head_idx = 1;
582 opts.src_index = &the_index;
583 opts.dst_index = &the_index;
584 opts.update = 1;
585 opts.verbose_update = 1;
586 opts.merge = 1;
587 opts.fn = twoway_merge;
588
589 trees[nr_trees] = parse_tree_indirect(head);
590 if (!trees[nr_trees++])
591 return -1;
592 trees[nr_trees] = parse_tree_indirect(remote);
593 if (!trees[nr_trees++])
594 return -1;
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 if (write_cache(fd, active_cache, active_nr) ||
602 commit_locked_index(lock_file))
603 die("unable to write new index file");
604 return 0;
605}
606
607static void split_merge_strategies(const char *string, struct strategy **list,
608 int *nr, int *alloc)
609{
610 char *p, *q, *buf;
611
612 if (!string)
613 return;
614
615 buf = xstrdup(string);
616 q = buf;
617 for (;;) {
618 p = strchr(q, ' ');
619 if (!p) {
620 ALLOC_GROW(*list, *nr + 1, *alloc);
621 (*list)[(*nr)++].name = xstrdup(q);
622 free(buf);
623 return;
624 } else {
625 *p = '\0';
626 ALLOC_GROW(*list, *nr + 1, *alloc);
627 (*list)[(*nr)++].name = xstrdup(q);
628 q = ++p;
629 }
630 }
631}
632
633static void add_strategies(const char *string, unsigned attr)
634{
635 struct strategy *list = NULL;
636 int list_alloc = 0, list_nr = 0, i;
637
638 memset(&list, 0, sizeof(list));
639 split_merge_strategies(string, &list, &list_nr, &list_alloc);
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640 if (list) {
641 for (i = 0; i < list_nr; i++)
642 append_strategy(get_strategy(list[i].name));
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643 return;
644 }
645 for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
646 if (all_strategy[i].attr & attr)
647 append_strategy(&all_strategy[i]);
648
649}
650
651static int merge_trivial(void)
652{
653 unsigned char result_tree[20], result_commit[20];
36e40535 654 struct commit_list *parent = xmalloc(sizeof(*parent));
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655
656 write_tree_trivial(result_tree);
657 printf("Wonderful.\n");
446247db 658 parent->item = lookup_commit(head);
36e40535 659 parent->next = xmalloc(sizeof(*parent->next));
446247db
JH
660 parent->next->item = remoteheads->item;
661 parent->next->next = NULL;
662 commit_tree(merge_msg.buf, result_tree, parent, result_commit);
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663 finish(result_commit, "In-index merge");
664 drop_save();
665 return 0;
666}
667
668static int finish_automerge(struct commit_list *common,
669 unsigned char *result_tree,
670 const char *wt_strategy)
671{
672 struct commit_list *parents = NULL, *j;
673 struct strbuf buf = STRBUF_INIT;
674 unsigned char result_commit[20];
675
676 free_commit_list(common);
677 if (allow_fast_forward) {
678 parents = remoteheads;
679 commit_list_insert(lookup_commit(head), &parents);
680 parents = reduce_heads(parents);
681 } else {
682 struct commit_list **pptr = &parents;
683
684 pptr = &commit_list_insert(lookup_commit(head),
685 pptr)->next;
686 for (j = remoteheads; j; j = j->next)
687 pptr = &commit_list_insert(j->item, pptr)->next;
688 }
689 free_commit_list(remoteheads);
690 strbuf_addch(&merge_msg, '\n');
691 commit_tree(merge_msg.buf, result_tree, parents, result_commit);
692 strbuf_addf(&buf, "Merge made by %s.", wt_strategy);
693 finish(result_commit, buf.buf);
694 strbuf_release(&buf);
695 drop_save();
696 return 0;
697}
698
699static int suggest_conflicts(void)
700{
701 FILE *fp;
702 int pos;
703
704 fp = fopen(git_path("MERGE_MSG"), "a");
705 if (!fp)
345f6e2c 706 die("Could not open %s for writing", git_path("MERGE_MSG"));
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707 fprintf(fp, "\nConflicts:\n");
708 for (pos = 0; pos < active_nr; pos++) {
709 struct cache_entry *ce = active_cache[pos];
710
711 if (ce_stage(ce)) {
712 fprintf(fp, "\t%s\n", ce->name);
713 while (pos + 1 < active_nr &&
714 !strcmp(ce->name,
715 active_cache[pos + 1]->name))
716 pos++;
717 }
718 }
719 fclose(fp);
720 rerere();
721 printf("Automatic merge failed; "
722 "fix conflicts and then commit the result.\n");
723 return 1;
724}
725
726static struct commit *is_old_style_invocation(int argc, const char **argv)
727{
728 struct commit *second_token = NULL;
729 if (argc > 1) {
730 unsigned char second_sha1[20];
731
732 if (get_sha1(argv[1], second_sha1))
733 return NULL;
734 second_token = lookup_commit_reference_gently(second_sha1, 0);
735 if (!second_token)
736 die("'%s' is not a commit", argv[1]);
737 if (hashcmp(second_token->object.sha1, head))
738 return NULL;
739 }
740 return second_token;
741}
742
743static int evaluate_result(void)
744{
745 int cnt = 0;
746 struct rev_info rev;
747
446247db 748 discard_cache();
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749 if (read_cache() < 0)
750 die("failed to read the cache");
751
752 /* Check how many files differ. */
753 init_revisions(&rev, "");
754 setup_revisions(0, NULL, &rev, NULL);
755 rev.diffopt.output_format |=
756 DIFF_FORMAT_CALLBACK;
757 rev.diffopt.format_callback = count_diff_files;
758 rev.diffopt.format_callback_data = &cnt;
759 run_diff_files(&rev, 0);
760
761 /*
762 * Check how many unmerged entries are
763 * there.
764 */
765 cnt += count_unmerged_entries();
766
767 return cnt;
768}
769
770int cmd_merge(int argc, const char **argv, const char *prefix)
771{
772 unsigned char result_tree[20];
773 struct strbuf buf;
774 const char *head_arg;
775 int flag, head_invalid = 0, i;
776 int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
777 struct commit_list *common = NULL;
778 const char *best_strategy = NULL, *wt_strategy = NULL;
779 struct commit_list **remotes = &remoteheads;
780
781 setup_work_tree();
446247db 782 if (read_cache_unmerged())
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783 die("You are in the middle of a conflicted merge.");
784
785 /*
786 * Check if we are _not_ on a detached HEAD, i.e. if there is a
787 * current branch.
788 */
789 branch = resolve_ref("HEAD", head, 0, &flag);
790 if (branch && !prefixcmp(branch, "refs/heads/"))
791 branch += 11;
792 if (is_null_sha1(head))
793 head_invalid = 1;
794
795 git_config(git_merge_config, NULL);
796
797 /* for color.ui */
798 if (diff_use_color_default == -1)
799 diff_use_color_default = git_use_color_default;
800
801 argc = parse_options(argc, argv, builtin_merge_options,
802 builtin_merge_usage, 0);
803
804 if (squash) {
805 if (!allow_fast_forward)
806 die("You cannot combine --squash with --no-ff.");
807 option_commit = 0;
808 }
809
810 if (!argc)
811 usage_with_options(builtin_merge_usage,
812 builtin_merge_options);
813
814 /*
815 * This could be traditional "merge <msg> HEAD <commit>..." and
816 * the way we can tell it is to see if the second token is HEAD,
817 * but some people might have misused the interface and used a
818 * committish that is the same as HEAD there instead.
819 * Traditional format never would have "-m" so it is an
820 * additional safety measure to check for it.
821 */
822 strbuf_init(&buf, 0);
823
824 if (!have_message && is_old_style_invocation(argc, argv)) {
825 strbuf_addstr(&merge_msg, argv[0]);
826 head_arg = argv[1];
827 argv += 2;
828 argc -= 2;
829 } else if (head_invalid) {
830 struct object *remote_head;
831 /*
832 * If the merged head is a valid one there is no reason
833 * to forbid "git merge" into a branch yet to be born.
834 * We do the same for "git pull".
835 */
836 if (argc != 1)
837 die("Can merge only exactly one commit into "
838 "empty head");
839 remote_head = peel_to_type(argv[0], 0, NULL, OBJ_COMMIT);
840 if (!remote_head)
841 die("%s - not something we can merge", argv[0]);
842 update_ref("initial pull", "HEAD", remote_head->sha1, NULL, 0,
843 DIE_ON_ERR);
844 reset_hard(remote_head->sha1, 0);
845 return 0;
846 } else {
847 struct strbuf msg;
848
849 /* We are invoked directly as the first-class UI. */
850 head_arg = "HEAD";
851
852 /*
853 * All the rest are the commits being merged;
854 * prepare the standard merge summary message to
855 * be appended to the given message. If remote
856 * is invalid we will die later in the common
857 * codepath so we discard the error in this
858 * loop.
859 */
860 strbuf_init(&msg, 0);
861 for (i = 0; i < argc; i++)
862 merge_name(argv[i], &msg);
863 fmt_merge_msg(option_log, &msg, &merge_msg);
864 if (merge_msg.len)
865 strbuf_setlen(&merge_msg, merge_msg.len-1);
866 }
867
868 if (head_invalid || !argc)
869 usage_with_options(builtin_merge_usage,
870 builtin_merge_options);
871
872 strbuf_addstr(&buf, "merge");
873 for (i = 0; i < argc; i++)
874 strbuf_addf(&buf, " %s", argv[i]);
875 setenv("GIT_REFLOG_ACTION", buf.buf, 0);
876 strbuf_reset(&buf);
877
878 for (i = 0; i < argc; i++) {
879 struct object *o;
880
881 o = peel_to_type(argv[i], 0, NULL, OBJ_COMMIT);
882 if (!o)
883 die("%s - not something we can merge", argv[i]);
884 remotes = &commit_list_insert(lookup_commit(o->sha1),
885 remotes)->next;
886
887 strbuf_addf(&buf, "GITHEAD_%s", sha1_to_hex(o->sha1));
888 setenv(buf.buf, argv[i], 1);
889 strbuf_reset(&buf);
890 }
891
892 if (!use_strategies) {
893 if (!remoteheads->next)
894 add_strategies(pull_twohead, DEFAULT_TWOHEAD);
895 else
896 add_strategies(pull_octopus, DEFAULT_OCTOPUS);
897 }
898
899 for (i = 0; i < use_strategies_nr; i++) {
900 if (use_strategies[i]->attr & NO_FAST_FORWARD)
901 allow_fast_forward = 0;
902 if (use_strategies[i]->attr & NO_TRIVIAL)
903 allow_trivial = 0;
904 }
905
906 if (!remoteheads->next)
907 common = get_merge_bases(lookup_commit(head),
908 remoteheads->item, 1);
909 else {
910 struct commit_list *list = remoteheads;
911 commit_list_insert(lookup_commit(head), &list);
912 common = get_octopus_merge_bases(list);
913 free(list);
914 }
915
916 update_ref("updating ORIG_HEAD", "ORIG_HEAD", head, NULL, 0,
917 DIE_ON_ERR);
918
919 if (!common)
920 ; /* No common ancestors found. We need a real merge. */
921 else if (!remoteheads->next && !common->next &&
922 common->item == remoteheads->item) {
923 /*
924 * If head can reach all the merge then we are up to date.
925 * but first the most common case of merging one remote.
926 */
927 finish_up_to_date("Already up-to-date.");
928 return 0;
929 } else if (allow_fast_forward && !remoteheads->next &&
930 !common->next &&
931 !hashcmp(common->item->object.sha1, head)) {
932 /* Again the most common case of merging one remote. */
933 struct strbuf msg;
934 struct object *o;
935 char hex[41];
936
937 strcpy(hex, find_unique_abbrev(head, DEFAULT_ABBREV));
938
939 printf("Updating %s..%s\n",
940 hex,
941 find_unique_abbrev(remoteheads->item->object.sha1,
942 DEFAULT_ABBREV));
1c7b76be
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943 strbuf_init(&msg, 0);
944 strbuf_addstr(&msg, "Fast forward");
945 if (have_message)
946 strbuf_addstr(&msg,
947 " (no commit created; -m option ignored)");
948 o = peel_to_type(sha1_to_hex(remoteheads->item->object.sha1),
949 0, NULL, OBJ_COMMIT);
950 if (!o)
951 return 1;
952
953 if (checkout_fast_forward(head, remoteheads->item->object.sha1))
954 return 1;
955
956 finish(o->sha1, msg.buf);
957 drop_save();
958 return 0;
959 } else if (!remoteheads->next && common->next)
960 ;
961 /*
962 * We are not doing octopus and not fast forward. Need
963 * a real merge.
964 */
965 else if (!remoteheads->next && !common->next && option_commit) {
966 /*
967 * We are not doing octopus, not fast forward, and have
968 * only one common.
969 */
970 refresh_cache(REFRESH_QUIET);
971 if (allow_trivial) {
972 /* See if it is really trivial. */
973 git_committer_info(IDENT_ERROR_ON_NO_NAME);
974 printf("Trying really trivial in-index merge...\n");
975 if (!read_tree_trivial(common->item->object.sha1,
976 head, remoteheads->item->object.sha1))
977 return merge_trivial();
978 printf("Nope.\n");
979 }
980 } else {
981 /*
982 * An octopus. If we can reach all the remote we are up
983 * to date.
984 */
985 int up_to_date = 1;
986 struct commit_list *j;
987
988 for (j = remoteheads; j; j = j->next) {
989 struct commit_list *common_one;
990
991 /*
992 * Here we *have* to calculate the individual
993 * merge_bases again, otherwise "git merge HEAD^
994 * HEAD^^" would be missed.
995 */
996 common_one = get_merge_bases(lookup_commit(head),
997 j->item, 1);
998 if (hashcmp(common_one->item->object.sha1,
999 j->item->object.sha1)) {
1000 up_to_date = 0;
1001 break;
1002 }
1003 }
1004 if (up_to_date) {
1005 finish_up_to_date("Already up-to-date. Yeeah!");
1006 return 0;
1007 }
1008 }
1009
1010 /* We are going to make a new commit. */
1011 git_committer_info(IDENT_ERROR_ON_NO_NAME);
1012
1013 /*
1014 * At this point, we need a real merge. No matter what strategy
1015 * we use, it would operate on the index, possibly affecting the
1016 * working tree, and when resolved cleanly, have the desired
1017 * tree in the index -- this means that the index must be in
1018 * sync with the head commit. The strategies are responsible
1019 * to ensure this.
1020 */
1021 if (use_strategies_nr != 1) {
1022 /*
1023 * Stash away the local changes so that we can try more
1024 * than one.
1025 */
1026 save_state();
1027 } else {
1028 memcpy(stash, null_sha1, 20);
1029 }
1030
1031 for (i = 0; i < use_strategies_nr; i++) {
1032 int ret;
1033 if (i) {
1034 printf("Rewinding the tree to pristine...\n");
1035 restore_state();
1036 }
1037 if (use_strategies_nr != 1)
1038 printf("Trying merge strategy %s...\n",
1039 use_strategies[i]->name);
1040 /*
1041 * Remember which strategy left the state in the working
1042 * tree.
1043 */
1044 wt_strategy = use_strategies[i]->name;
1045
1046 ret = try_merge_strategy(use_strategies[i]->name,
1047 common, head_arg);
1048 if (!option_commit && !ret) {
1049 merge_was_ok = 1;
1050 /*
1051 * This is necessary here just to avoid writing
1052 * the tree, but later we will *not* exit with
1053 * status code 1 because merge_was_ok is set.
1054 */
1055 ret = 1;
1056 }
1057
1058 if (ret) {
1059 /*
1060 * The backend exits with 1 when conflicts are
1061 * left to be resolved, with 2 when it does not
1062 * handle the given merge at all.
1063 */
1064 if (ret == 1) {
1065 int cnt = evaluate_result();
1066
1067 if (best_cnt <= 0 || cnt <= best_cnt) {
1068 best_strategy = use_strategies[i]->name;
1069 best_cnt = cnt;
1070 }
1071 }
1072 if (merge_was_ok)
1073 break;
1074 else
1075 continue;
1076 }
1077
1078 /* Automerge succeeded. */
446247db 1079 discard_cache();
1c7b76be
MV
1080 write_tree_trivial(result_tree);
1081 automerge_was_ok = 1;
1082 break;
1083 }
1084
1085 /*
1086 * If we have a resulting tree, that means the strategy module
1087 * auto resolved the merge cleanly.
1088 */
1089 if (automerge_was_ok)
1090 return finish_automerge(common, result_tree, wt_strategy);
1091
1092 /*
1093 * Pick the result from the best strategy and have the user fix
1094 * it up.
1095 */
1096 if (!best_strategy) {
1097 restore_state();
1098 if (use_strategies_nr > 1)
1099 fprintf(stderr,
1100 "No merge strategy handled the merge.\n");
1101 else
1102 fprintf(stderr, "Merge with strategy %s failed.\n",
1103 use_strategies[0]->name);
1104 return 2;
1105 } else if (best_strategy == wt_strategy)
1106 ; /* We already have its result in the working tree. */
1107 else {
1108 printf("Rewinding the tree to pristine...\n");
1109 restore_state();
1110 printf("Using the %s to prepare resolving by hand.\n",
1111 best_strategy);
1112 try_merge_strategy(best_strategy, common, head_arg);
1113 }
1114
1115 if (squash)
1116 finish(NULL, NULL);
1117 else {
1118 int fd;
1119 struct commit_list *j;
1120
1121 for (j = remoteheads; j; j = j->next)
1122 strbuf_addf(&buf, "%s\n",
1123 sha1_to_hex(j->item->object.sha1));
1124 fd = open(git_path("MERGE_HEAD"), O_WRONLY | O_CREAT, 0666);
1125 if (fd < 0)
1126 die("Could open %s for writing",
1127 git_path("MERGE_HEAD"));
1128 if (write_in_full(fd, buf.buf, buf.len) != buf.len)
1129 die("Could not write to %s", git_path("MERGE_HEAD"));
1130 close(fd);
1131 strbuf_addch(&merge_msg, '\n');
1132 fd = open(git_path("MERGE_MSG"), O_WRONLY | O_CREAT, 0666);
1133 if (fd < 0)
1134 die("Could open %s for writing", git_path("MERGE_MSG"));
1135 if (write_in_full(fd, merge_msg.buf, merge_msg.len) !=
1136 merge_msg.len)
1137 die("Could not write to %s", git_path("MERGE_MSG"));
1138 close(fd);
1139 }
1140
1141 if (merge_was_ok) {
1142 fprintf(stderr, "Automatic merge went well; "
1143 "stopped before committing as requested\n");
1144 return 0;
1145 } else
1146 return suggest_conflicts();
1147}