1#include "cache.h"
2#include "submodule.h"
3#include "dir.h"
4#include "diff.h"
5#include "commit.h"
6#include "revision.h"
7#include "run-command.h"
8#include "diffcore.h"
9#include "refs.h"
10#include "string-list.h"
11static struct string_list config_name_for_path;
13static struct string_list config_fetch_recurse_submodules_for_name;
14static struct string_list config_ignore_for_name;
15static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
16static struct string_list changed_submodule_paths;
17/*
18 * The following flag is set if the .gitmodules file is unmerged. We then
19 * disable recursion for all submodules where .git/config doesn't have a
20 * matching config entry because we can't guess what might be configured in
21 * .gitmodules unless the user resolves the conflict. When a command line
22 * option is given (which always overrides configuration) this flag will be
23 * ignored.
24 */
25static int gitmodules_is_unmerged;
26static int add_submodule_odb(const char *path)
28{
29 struct strbuf objects_directory = STRBUF_INIT;
30 struct alternate_object_database *alt_odb;
31 int ret = 0;
32 const char *git_dir;
33 strbuf_addf(&objects_directory, "%s/.git", path);
35 git_dir = read_gitfile_gently(objects_directory.buf);
36 if (git_dir) {
37 strbuf_reset(&objects_directory);
38 strbuf_addstr(&objects_directory, git_dir);
39 }
40 strbuf_addstr(&objects_directory, "/objects/");
41 if (!is_directory(objects_directory.buf)) {
42 ret = -1;
43 goto done;
44 }
45 /* avoid adding it twice */
46 for (alt_odb = alt_odb_list; alt_odb; alt_odb = alt_odb->next)
47 if (alt_odb->name - alt_odb->base == objects_directory.len &&
48 !strncmp(alt_odb->base, objects_directory.buf,
49 objects_directory.len))
50 goto done;
51 alt_odb = xmalloc(objects_directory.len + 42 + sizeof(*alt_odb));
53 alt_odb->next = alt_odb_list;
54 strcpy(alt_odb->base, objects_directory.buf);
55 alt_odb->name = alt_odb->base + objects_directory.len;
56 alt_odb->name[2] = '/';
57 alt_odb->name[40] = '\0';
58 alt_odb->name[41] = '\0';
59 alt_odb_list = alt_odb;
60 prepare_alt_odb();
61done:
62 strbuf_release(&objects_directory);
63 return ret;
64}
65void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
67 const char *path)
68{
69 struct string_list_item *path_option, *ignore_option;
70 path_option = unsorted_string_list_lookup(&config_name_for_path, path);
71 if (path_option) {
72 ignore_option = unsorted_string_list_lookup(&config_ignore_for_name, path_option->util);
73 if (ignore_option)
74 handle_ignore_submodules_arg(diffopt, ignore_option->util);
75 else if (gitmodules_is_unmerged)
76 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
77 }
78}
79int submodule_config(const char *var, const char *value, void *cb)
81{
82 if (!prefixcmp(var, "submodule."))
83 return parse_submodule_config_option(var, value);
84 else if (!strcmp(var, "fetch.recursesubmodules")) {
85 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
86 return 0;
87 }
88 return 0;
89}
90void gitmodules_config(void)
92{
93 const char *work_tree = get_git_work_tree();
94 if (work_tree) {
95 struct strbuf gitmodules_path = STRBUF_INIT;
96 int pos;
97 strbuf_addstr(&gitmodules_path, work_tree);
98 strbuf_addstr(&gitmodules_path, "/.gitmodules");
99 if (read_cache() < 0)
100 die("index file corrupt");
101 pos = cache_name_pos(".gitmodules", 11);
102 if (pos < 0) { /* .gitmodules not found or isn't merged */
103 pos = -1 - pos;
104 if (active_nr > pos) { /* there is a .gitmodules */
105 const struct cache_entry *ce = active_cache[pos];
106 if (ce_namelen(ce) == 11 &&
107 !memcmp(ce->name, ".gitmodules", 11))
108 gitmodules_is_unmerged = 1;
109 }
110 }
111 if (!gitmodules_is_unmerged)
113 git_config_from_file(submodule_config, gitmodules_path.buf, NULL);
114 strbuf_release(&gitmodules_path);
115 }
116}
117int parse_submodule_config_option(const char *var, const char *value)
119{
120 int len;
121 struct string_list_item *config;
122 struct strbuf submodname = STRBUF_INIT;
123 var += 10; /* Skip "submodule." */
125 len = strlen(var);
127 if ((len > 5) && !strcmp(var + len - 5, ".path")) {
128 strbuf_add(&submodname, var, len - 5);
129 config = unsorted_string_list_lookup(&config_name_for_path, value);
130 if (config)
131 free(config->util);
132 else
133 config = string_list_append(&config_name_for_path, xstrdup(value));
134 config->util = strbuf_detach(&submodname, NULL);
135 strbuf_release(&submodname);
136 } else if ((len > 23) && !strcmp(var + len - 23, ".fetchrecursesubmodules")) {
137 strbuf_add(&submodname, var, len - 23);
138 config = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, submodname.buf);
139 if (!config)
140 config = string_list_append(&config_fetch_recurse_submodules_for_name,
141 strbuf_detach(&submodname, NULL));
142 config->util = (void *)(intptr_t)parse_fetch_recurse_submodules_arg(var, value);
143 strbuf_release(&submodname);
144 } else if ((len > 7) && !strcmp(var + len - 7, ".ignore")) {
145 if (strcmp(value, "untracked") && strcmp(value, "dirty") &&
146 strcmp(value, "all") && strcmp(value, "none")) {
147 warning("Invalid parameter \"%s\" for config option \"submodule.%s.ignore\"", value, var);
148 return 0;
149 }
150 strbuf_add(&submodname, var, len - 7);
152 config = unsorted_string_list_lookup(&config_ignore_for_name, submodname.buf);
153 if (config)
154 free(config->util);
155 else
156 config = string_list_append(&config_ignore_for_name,
157 strbuf_detach(&submodname, NULL));
158 strbuf_release(&submodname);
159 config->util = xstrdup(value);
160 return 0;
161 }
162 return 0;
163}
164void handle_ignore_submodules_arg(struct diff_options *diffopt,
166 const char *arg)
167{
168 DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
169 DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
170 DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
171 if (!strcmp(arg, "all"))
173 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
174 else if (!strcmp(arg, "untracked"))
175 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
176 else if (!strcmp(arg, "dirty"))
177 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
178 else if (strcmp(arg, "none"))
179 die("bad --ignore-submodules argument: %s", arg);
180}
181static int prepare_submodule_summary(struct rev_info *rev, const char *path,
183 struct commit *left, struct commit *right,
184 int *fast_forward, int *fast_backward)
185{
186 struct commit_list *merge_bases, *list;
187 init_revisions(rev, NULL);
189 setup_revisions(0, NULL, rev, NULL);
190 rev->left_right = 1;
191 rev->first_parent_only = 1;
192 left->object.flags |= SYMMETRIC_LEFT;
193 add_pending_object(rev, &left->object, path);
194 add_pending_object(rev, &right->object, path);
195 merge_bases = get_merge_bases(left, right, 1);
196 if (merge_bases) {
197 if (merge_bases->item == left)
198 *fast_forward = 1;
199 else if (merge_bases->item == right)
200 *fast_backward = 1;
201 }
202 for (list = merge_bases; list; list = list->next) {
203 list->item->object.flags |= UNINTERESTING;
204 add_pending_object(rev, &list->item->object,
205 sha1_to_hex(list->item->object.sha1));
206 }
207 return prepare_revision_walk(rev);
208}
209static void print_submodule_summary(struct rev_info *rev, FILE *f,
211 const char *del, const char *add, const char *reset)
212{
213 static const char format[] = " %m %s";
214 struct strbuf sb = STRBUF_INIT;
215 struct commit *commit;
216 while ((commit = get_revision(rev))) {
218 struct pretty_print_context ctx = {0};
219 ctx.date_mode = rev->date_mode;
220 strbuf_setlen(&sb, 0);
221 if (commit->object.flags & SYMMETRIC_LEFT) {
222 if (del)
223 strbuf_addstr(&sb, del);
224 }
225 else if (add)
226 strbuf_addstr(&sb, add);
227 format_commit_message(commit, format, &sb, &ctx);
228 if (reset)
229 strbuf_addstr(&sb, reset);
230 strbuf_addch(&sb, '\n');
231 fprintf(f, "%s", sb.buf);
232 }
233 strbuf_release(&sb);
234}
235int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg)
237{
238 switch (git_config_maybe_bool(opt, arg)) {
239 case 1:
240 return RECURSE_SUBMODULES_ON;
241 case 0:
242 return RECURSE_SUBMODULES_OFF;
243 default:
244 if (!strcmp(arg, "on-demand"))
245 return RECURSE_SUBMODULES_ON_DEMAND;
246 die("bad %s argument: %s", opt, arg);
247 }
248}
249void show_submodule_summary(FILE *f, const char *path,
251 unsigned char one[20], unsigned char two[20],
252 unsigned dirty_submodule,
253 const char *del, const char *add, const char *reset)
254{
255 struct rev_info rev;
256 struct commit *left = left, *right = right;
257 const char *message = NULL;
258 struct strbuf sb = STRBUF_INIT;
259 int fast_forward = 0, fast_backward = 0;
260 if (is_null_sha1(two))
262 message = "(submodule deleted)";
263 else if (add_submodule_odb(path))
264 message = "(not checked out)";
265 else if (is_null_sha1(one))
266 message = "(new submodule)";
267 else if (!(left = lookup_commit_reference(one)) ||
268 !(right = lookup_commit_reference(two)))
269 message = "(commits not present)";
270 if (!message &&
272 prepare_submodule_summary(&rev, path, left, right,
273 &fast_forward, &fast_backward))
274 message = "(revision walker failed)";
275 if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
277 fprintf(f, "Submodule %s contains untracked content\n", path);
278 if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
279 fprintf(f, "Submodule %s contains modified content\n", path);
280 if (!hashcmp(one, two)) {
282 strbuf_release(&sb);
283 return;
284 }
285 strbuf_addf(&sb, "Submodule %s %s..", path,
287 find_unique_abbrev(one, DEFAULT_ABBREV));
288 if (!fast_backward && !fast_forward)
289 strbuf_addch(&sb, '.');
290 strbuf_addf(&sb, "%s", find_unique_abbrev(two, DEFAULT_ABBREV));
291 if (message)
292 strbuf_addf(&sb, " %s\n", message);
293 else
294 strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
295 fwrite(sb.buf, sb.len, 1, f);
296 if (!message) {
298 print_submodule_summary(&rev, f, del, add, reset);
299 clear_commit_marks(left, ~0);
300 clear_commit_marks(right, ~0);
301 }
302 strbuf_release(&sb);
304}
305void set_config_fetch_recurse_submodules(int value)
307{
308 config_fetch_recurse_submodules = value;
309}
310static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
312{
313 int is_present = 0;
314 if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
315 /* Even if the submodule is checked out and the commit is
316 * present, make sure it is reachable from a ref. */
317 struct child_process cp;
318 const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
319 struct strbuf buf = STRBUF_INIT;
320 argv[3] = sha1_to_hex(sha1);
322 memset(&cp, 0, sizeof(cp));
323 cp.argv = argv;
324 cp.env = local_repo_env;
325 cp.git_cmd = 1;
326 cp.no_stdin = 1;
327 cp.out = -1;
328 cp.dir = path;
329 if (!run_command(&cp) && !strbuf_read(&buf, cp.out, 1024))
330 is_present = 1;
331 close(cp.out);
333 strbuf_release(&buf);
334 }
335 return is_present;
336}
337static void submodule_collect_changed_cb(struct diff_queue_struct *q,
339 struct diff_options *options,
340 void *data)
341{
342 int i;
343 for (i = 0; i < q->nr; i++) {
344 struct diff_filepair *p = q->queue[i];
345 if (!S_ISGITLINK(p->two->mode))
346 continue;
347 if (S_ISGITLINK(p->one->mode)) {
349 /* NEEDSWORK: We should honor the name configured in
350 * the .gitmodules file of the commit we are examining
351 * here to be able to correctly follow submodules
352 * being moved around. */
353 struct string_list_item *path;
354 path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
355 if (!path && !is_submodule_commit_present(p->two->path, p->two->sha1))
356 string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
357 } else {
358 /* Submodule is new or was moved here */
359 /* NEEDSWORK: When the .git directories of submodules
360 * live inside the superprojects .git directory some
361 * day we should fetch new submodules directly into
362 * that location too when config or options request
363 * that so they can be checked out from there. */
364 continue;
365 }
366 }
367}
368void check_for_new_submodule_commits(unsigned char new_sha1[20])
370{
371 struct rev_info rev;
372 struct commit *commit;
373 const char *argv[] = {NULL, NULL, "--not", "--all", NULL};
374 int argc = ARRAY_SIZE(argv) - 1;
375 init_revisions(&rev, NULL);
377 argv[1] = xstrdup(sha1_to_hex(new_sha1));
378 setup_revisions(argc, argv, &rev, NULL);
379 if (prepare_revision_walk(&rev))
380 die("revision walk setup failed");
381 /*
383 * Collect all submodules (whether checked out or not) for which new
384 * commits have been recorded upstream in "changed_submodule_paths".
385 */
386 while ((commit = get_revision(&rev))) {
387 struct commit_list *parent = commit->parents;
388 while (parent) {
389 struct diff_options diff_opts;
390 diff_setup(&diff_opts);
391 DIFF_OPT_SET(&diff_opts, RECURSIVE);
392 diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
393 diff_opts.format_callback = submodule_collect_changed_cb;
394 if (diff_setup_done(&diff_opts) < 0)
395 die("diff_setup_done failed");
396 diff_tree_sha1(parent->item->object.sha1, commit->object.sha1, "", &diff_opts);
397 diffcore_std(&diff_opts);
398 diff_flush(&diff_opts);
399 parent = parent->next;
400 }
401 }
402 free((char *)argv[1]);
403}
404int fetch_populated_submodules(int num_options, const char **options,
406 const char *prefix, int command_line_option,
407 int quiet)
408{
409 int i, result = 0, argc = 0, default_argc;
410 struct child_process cp;
411 const char **argv;
412 struct string_list_item *name_for_path;
413 const char *work_tree = get_git_work_tree();
414 if (!work_tree)
415 goto out;
416 if (!the_index.initialized)
418 if (read_cache() < 0)
419 die("index file corrupt");
420 /* 6: "fetch" (options) --recurse-submodules-default default "--submodule-prefix" prefix NULL */
422 argv = xcalloc(num_options + 6, sizeof(const char *));
423 argv[argc++] = "fetch";
424 for (i = 0; i < num_options; i++)
425 argv[argc++] = options[i];
426 argv[argc++] = "--recurse-submodules-default";
427 default_argc = argc++;
428 argv[argc++] = "--submodule-prefix";
429 memset(&cp, 0, sizeof(cp));
431 cp.argv = argv;
432 cp.env = local_repo_env;
433 cp.git_cmd = 1;
434 cp.no_stdin = 1;
435 for (i = 0; i < active_nr; i++) {
437 struct strbuf submodule_path = STRBUF_INIT;
438 struct strbuf submodule_git_dir = STRBUF_INIT;
439 struct strbuf submodule_prefix = STRBUF_INIT;
440 struct cache_entry *ce = active_cache[i];
441 const char *git_dir, *name, *default_argv;
442 if (!S_ISGITLINK(ce->ce_mode))
444 continue;
445 name = ce->name;
447 name_for_path = unsorted_string_list_lookup(&config_name_for_path, ce->name);
448 if (name_for_path)
449 name = name_for_path->util;
450 default_argv = "yes";
452 if (command_line_option == RECURSE_SUBMODULES_DEFAULT) {
453 struct string_list_item *fetch_recurse_submodules_option;
454 fetch_recurse_submodules_option = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name);
455 if (fetch_recurse_submodules_option) {
456 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_OFF)
457 continue;
458 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_ON_DEMAND) {
459 if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
460 continue;
461 default_argv = "on-demand";
462 }
463 } else {
464 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
465 gitmodules_is_unmerged)
466 continue;
467 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
468 if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
469 continue;
470 default_argv = "on-demand";
471 }
472 }
473 } else if (command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
474 if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
475 continue;
476 default_argv = "on-demand";
477 }
478 strbuf_addf(&submodule_path, "%s/%s", work_tree, ce->name);
480 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
481 strbuf_addf(&submodule_prefix, "%s%s/", prefix, ce->name);
482 git_dir = read_gitfile_gently(submodule_git_dir.buf);
483 if (!git_dir)
484 git_dir = submodule_git_dir.buf;
485 if (is_directory(git_dir)) {
486 if (!quiet)
487 printf("Fetching submodule %s%s\n", prefix, ce->name);
488 cp.dir = submodule_path.buf;
489 argv[default_argc] = default_argv;
490 argv[argc] = submodule_prefix.buf;
491 if (run_command(&cp))
492 result = 1;
493 }
494 strbuf_release(&submodule_path);
495 strbuf_release(&submodule_git_dir);
496 strbuf_release(&submodule_prefix);
497 }
498 free(argv);
499out:
500 string_list_clear(&changed_submodule_paths, 1);
501 return result;
502}
503unsigned is_submodule_modified(const char *path, int ignore_untracked)
505{
506 ssize_t len;
507 struct child_process cp;
508 const char *argv[] = {
509 "status",
510 "--porcelain",
511 NULL,
512 NULL,
513 };
514 struct strbuf buf = STRBUF_INIT;
515 unsigned dirty_submodule = 0;
516 const char *line, *next_line;
517 const char *git_dir;
518 strbuf_addf(&buf, "%s/.git", path);
520 git_dir = read_gitfile_gently(buf.buf);
521 if (!git_dir)
522 git_dir = buf.buf;
523 if (!is_directory(git_dir)) {
524 strbuf_release(&buf);
525 /* The submodule is not checked out, so it is not modified */
526 return 0;
527 }
529 strbuf_reset(&buf);
530 if (ignore_untracked)
532 argv[2] = "-uno";
533 memset(&cp, 0, sizeof(cp));
535 cp.argv = argv;
536 cp.env = local_repo_env;
537 cp.git_cmd = 1;
538 cp.no_stdin = 1;
539 cp.out = -1;
540 cp.dir = path;
541 if (start_command(&cp))
542 die("Could not run git status --porcelain");
543 len = strbuf_read(&buf, cp.out, 1024);
545 line = buf.buf;
546 while (len > 2) {
547 if ((line[0] == '?') && (line[1] == '?')) {
548 dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
549 if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
550 break;
551 } else {
552 dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
553 if (ignore_untracked ||
554 (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
555 break;
556 }
557 next_line = strchr(line, '\n');
558 if (!next_line)
559 break;
560 next_line++;
561 len -= (next_line - line);
562 line = next_line;
563 }
564 close(cp.out);
565 if (finish_command(&cp))
567 die("git status --porcelain failed");
568 strbuf_release(&buf);
570 return dirty_submodule;
571}
572static int find_first_merges(struct object_array *result, const char *path,
574 struct commit *a, struct commit *b)
575{
576 int i, j;
577 struct object_array merges;
578 struct commit *commit;
579 int contains_another;
580 char merged_revision[42];
582 const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
583 "--all", merged_revision, NULL };
584 struct rev_info revs;
585 struct setup_revision_opt rev_opts;
586 memset(&merges, 0, sizeof(merges));
588 memset(result, 0, sizeof(struct object_array));
589 memset(&rev_opts, 0, sizeof(rev_opts));
590 /* get all revisions that merge commit a */
592 snprintf(merged_revision, sizeof(merged_revision), "^%s",
593 sha1_to_hex(a->object.sha1));
594 init_revisions(&revs, NULL);
595 rev_opts.submodule = path;
596 setup_revisions(sizeof(rev_args)/sizeof(char *)-1, rev_args, &revs, &rev_opts);
597 /* save all revisions from the above list that contain b */
599 if (prepare_revision_walk(&revs))
600 die("revision walk setup failed");
601 while ((commit = get_revision(&revs)) != NULL) {
602 struct object *o = &(commit->object);
603 if (in_merge_bases(b, &commit, 1))
604 add_object_array(o, NULL, &merges);
605 }
606 /* Now we've got all merges that contain a and b. Prune all
608 * merges that contain another found merge and save them in
609 * result.
610 */
611 for (i = 0; i < merges.nr; i++) {
612 struct commit *m1 = (struct commit *) merges.objects[i].item;
613 contains_another = 0;
615 for (j = 0; j < merges.nr; j++) {
616 struct commit *m2 = (struct commit *) merges.objects[j].item;
617 if (i != j && in_merge_bases(m2, &m1, 1)) {
618 contains_another = 1;
619 break;
620 }
621 }
622 if (!contains_another)
624 add_object_array(merges.objects[i].item,
625 merges.objects[i].name, result);
626 }
627 free(merges.objects);
629 return result->nr;
630}
631static void print_commit(struct commit *commit)
633{
634 struct strbuf sb = STRBUF_INIT;
635 struct pretty_print_context ctx = {0};
636 ctx.date_mode = DATE_NORMAL;
637 format_commit_message(commit, " %h: %m %s", &sb, &ctx);
638 fprintf(stderr, "%s\n", sb.buf);
639 strbuf_release(&sb);
640}
641#define MERGE_WARNING(path, msg) \
643 warning("Failed to merge submodule %s (%s)", path, msg);
644int merge_submodule(unsigned char result[20], const char *path,
646 const unsigned char base[20], const unsigned char a[20],
647 const unsigned char b[20])
648{
649 struct commit *commit_base, *commit_a, *commit_b;
650 int parent_count;
651 struct object_array merges;
652 int i;
654 /* store a in result in case we fail */
656 hashcpy(result, a);
657 /* we can not handle deletion conflicts */
659 if (is_null_sha1(base))
660 return 0;
661 if (is_null_sha1(a))
662 return 0;
663 if (is_null_sha1(b))
664 return 0;
665 if (add_submodule_odb(path)) {
667 MERGE_WARNING(path, "not checked out");
668 return 0;
669 }
670 if (!(commit_base = lookup_commit_reference(base)) ||
672 !(commit_a = lookup_commit_reference(a)) ||
673 !(commit_b = lookup_commit_reference(b))) {
674 MERGE_WARNING(path, "commits not present");
675 return 0;
676 }
677 /* check whether both changes are forward */
679 if (!in_merge_bases(commit_base, &commit_a, 1) ||
680 !in_merge_bases(commit_base, &commit_b, 1)) {
681 MERGE_WARNING(path, "commits don't follow merge-base");
682 return 0;
683 }
684 /* Case #1: a is contained in b or vice versa */
686 if (in_merge_bases(commit_a, &commit_b, 1)) {
687 hashcpy(result, b);
688 return 1;
689 }
690 if (in_merge_bases(commit_b, &commit_a, 1)) {
691 hashcpy(result, a);
692 return 1;
693 }
694 /*
696 * Case #2: There are one or more merges that contain a and b in
697 * the submodule. If there is only one, then present it as a
698 * suggestion to the user, but leave it marked unmerged so the
699 * user needs to confirm the resolution.
700 */
701 /* find commit which merges them */
703 parent_count = find_first_merges(&merges, path, commit_a, commit_b);
704 switch (parent_count) {
705 case 0:
706 MERGE_WARNING(path, "merge following commits not found");
707 break;
708 case 1:
710 MERGE_WARNING(path, "not fast-forward");
711 fprintf(stderr, "Found a possible merge resolution "
712 "for the submodule:\n");
713 print_commit((struct commit *) merges.objects[0].item);
714 fprintf(stderr,
715 "If this is correct simply add it to the index "
716 "for example\n"
717 "by using:\n\n"
718 " git update-index --cacheinfo 160000 %s \"%s\"\n\n"
719 "which will accept this suggestion.\n",
720 sha1_to_hex(merges.objects[0].item->sha1), path);
721 break;
722 default:
724 MERGE_WARNING(path, "multiple merges found");
725 for (i = 0; i < merges.nr; i++)
726 print_commit((struct commit *) merges.objects[i].item);
727 }
728 free(merges.objects);
730 return 0;
731}