merge-base: Do not read parents from the root
diff --git a/src/merge.c b/src/merge.c
index 0c132c4..44904ca 100644
--- a/src/merge.c
+++ b/src/merge.c
@@ -318,7 +318,7 @@ static void clear_commit_marks_1(git_commit_list **plist,
git_commit_list_insert(p, plist);
}
- commit = commit->parents[0];
+ commit = commit->out_degree ? commit->parents[0] : NULL;
}
}