Fix head not hashed (#3680)

* fix head not hashed

* bump version

substrate/srml/support/src/storage/generator/linked_map.rs

@@ -36,7 +36,7 @@ pub trait StorageLinkedMap<K: Codec, V: Codec> {
 	fn prefix() -> &'static [u8];
 
 	/// Key used to store linked map head.
-	fn final_head_key() -> &'static [u8];
+	fn head_key() -> &'static [u8];
 
 	/// Convert an optionnal value retrieved from storage to the type queried.
 	fn from_optional_value_to_query(v: Option<V>) -> Self::Query;
@@ -53,6 +53,11 @@ pub trait StorageLinkedMap<K: Codec, V: Codec> {
 		key.borrow().encode_to(&mut final_key);
 		Self::Hasher::hash(&final_key)
 	}
+
+	/// Generate the hashed key for head
+	fn storage_linked_map_final_head_key() -> <Self::Hasher as StorageHasher>::Output {
+		Self::Hasher::hash(Self::head_key())
+	}
 }
 
 /// Linkage data of an element (it's successor and predecessor)
@@ -181,7 +186,7 @@ where
 	V: Codec,
 	G: StorageLinkedMap<K, V>
 {
-	unhashed::get(G::final_head_key())
+	unhashed::get(G::storage_linked_map_final_head_key().as_ref())
 }
 
 /// Overwrite current head pointer.
@@ -194,8 +199,8 @@ where
 	G: StorageLinkedMap<K, V>
 {
 	match head {
-		Some(head) => unhashed::put(G::final_head_key(), head),
-		None => unhashed::kill(G::final_head_key()),
+		Some(head) => unhashed::put(G::storage_linked_map_final_head_key().as_ref(), head),
+		None => unhashed::kill(G::storage_linked_map_final_head_key().as_ref()),
 	}
 }
 

substrate/srml/support/src/storage/storage_items.rs

@@ -758,7 +758,7 @@ mod test3 {
 #[cfg(test)]
 #[allow(dead_code)]
 mod test_append_and_len {
-	use crate::storage::{StorageMap, StorageValue, StorageLinkedMap};
+	use crate::storage::{StorageMap, StorageValue};
 	use runtime_io::{with_externalities, TestExternalities};
 	use codec::{Encode, Decode};