#include "revision.h"
#include "run-command.h"
#include "diffcore.h"
+#include "refs.h"
#include "string-list.h"
struct string_list config_name_for_path;
strbuf_release(&buf);
return dirty_submodule;
}
+
+static int find_first_merges(struct object_array *result, const char *path,
+ struct commit *a, struct commit *b)
+{
+ int i, j;
+ struct object_array merges;
+ struct commit *commit;
+ int contains_another;
+
+ char merged_revision[42];
+ const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
+ "--all", merged_revision, NULL };
+ struct rev_info revs;
+ struct setup_revision_opt rev_opts;
+
+ memset(&merges, 0, sizeof(merges));
+ memset(result, 0, sizeof(struct object_array));
+ memset(&rev_opts, 0, sizeof(rev_opts));
+
+ /* get all revisions that merge commit a */
+ snprintf(merged_revision, sizeof(merged_revision), "^%s",
+ sha1_to_hex(a->object.sha1));
+ init_revisions(&revs, NULL);
+ rev_opts.submodule = path;
+ setup_revisions(sizeof(rev_args)/sizeof(char *)-1, rev_args, &revs, &rev_opts);
+
+ /* save all revisions from the above list that contain b */
+ if (prepare_revision_walk(&revs))
+ die("revision walk setup failed");
+ while ((commit = get_revision(&revs)) != NULL) {
+ struct object *o = &(commit->object);
+ if (in_merge_bases(b, &commit, 1))
+ add_object_array(o, NULL, &merges);
+ }
+
+ /* Now we've got all merges that contain a and b. Prune all
+ * merges that contain another found merge and save them in
+ * result.
+ */
+ for (i = 0; i < merges.nr; i++) {
+ struct commit *m1 = (struct commit *) merges.objects[i].item;
+
+ contains_another = 0;
+ for (j = 0; j < merges.nr; j++) {
+ struct commit *m2 = (struct commit *) merges.objects[j].item;
+ if (i != j && in_merge_bases(m2, &m1, 1)) {
+ contains_another = 1;
+ break;
+ }
+ }
+
+ if (!contains_another)
+ add_object_array(merges.objects[i].item,
+ merges.objects[i].name, result);
+ }
+
+ free(merges.objects);
+ return result->nr;
+}
+
+static void print_commit(struct commit *commit)
+{
+ struct strbuf sb = STRBUF_INIT;
+ struct pretty_print_context ctx = {0};
+ ctx.date_mode = DATE_NORMAL;
+ format_commit_message(commit, " %h: %m %s", &sb, &ctx);
+ fprintf(stderr, "%s\n", sb.buf);
+ strbuf_release(&sb);
+}
+
+#define MERGE_WARNING(path, msg) \
+ warning("Failed to merge submodule %s (%s)", path, msg);
+
+int merge_submodule(unsigned char result[20], const char *path,
+ const unsigned char base[20], const unsigned char a[20],
+ const unsigned char b[20])
+{
+ struct commit *commit_base, *commit_a, *commit_b;
+ int parent_count;
+ struct object_array merges;
+
+ int i;
+
+ /* store a in result in case we fail */
+ hashcpy(result, a);
+
+ /* we can not handle deletion conflicts */
+ if (is_null_sha1(base))
+ return 0;
+ if (is_null_sha1(a))
+ return 0;
+ if (is_null_sha1(b))
+ return 0;
+
+ if (add_submodule_odb(path)) {
+ MERGE_WARNING(path, "not checked out");
+ return 0;
+ }
+
+ if (!(commit_base = lookup_commit_reference(base)) ||
+ !(commit_a = lookup_commit_reference(a)) ||
+ !(commit_b = lookup_commit_reference(b))) {
+ MERGE_WARNING(path, "commits not present");
+ return 0;
+ }
+
+ /* check whether both changes are forward */
+ if (!in_merge_bases(commit_base, &commit_a, 1) ||
+ !in_merge_bases(commit_base, &commit_b, 1)) {
+ MERGE_WARNING(path, "commits don't follow merge-base");
+ return 0;
+ }
+
+ /* Case #1: a is contained in b or vice versa */
+ if (in_merge_bases(commit_a, &commit_b, 1)) {
+ hashcpy(result, b);
+ return 1;
+ }
+ if (in_merge_bases(commit_b, &commit_a, 1)) {
+ hashcpy(result, a);
+ return 1;
+ }
+
+ /*
+ * Case #2: There are one or more merges that contain a and b in
+ * the submodule. If there is only one, then present it as a
+ * suggestion to the user, but leave it marked unmerged so the
+ * user needs to confirm the resolution.
+ */
+
+ /* find commit which merges them */
+ parent_count = find_first_merges(&merges, path, commit_a, commit_b);
+ switch (parent_count) {
+ case 0:
+ MERGE_WARNING(path, "merge following commits not found");
+ break;
+
+ case 1:
+ MERGE_WARNING(path, "not fast-forward");
+ fprintf(stderr, "Found a possible merge resolution "
+ "for the submodule:\n");
+ print_commit((struct commit *) merges.objects[0].item);
+ fprintf(stderr,
+ "If this is correct simply add it to the index "
+ "for example\n"
+ "by using:\n\n"
+ " git update-index --cacheinfo 160000 %s \"%s\"\n\n"
+ "which will accept this suggestion.\n",
+ sha1_to_hex(merges.objects[0].item->sha1), path);
+ break;
+
+ default:
+ MERGE_WARNING(path, "multiple merges found");
+ for (i = 0; i < merges.nr; i++)
+ print_commit((struct commit *) merges.objects[i].item);
+ }
+
+ free(merges.objects);
+ return 0;
+}