Fix decl_storage map and linked_map for insert_ref (#3316)

* test

* fix

* bumpd version

* Update srml/support/procedural/src/storage/impls.rs

Co-Authored-By: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/srml/support/procedural/src/storage/impls.rs

@@ -615,6 +615,27 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 					storage.put(key_for, &(val, linkage))
 				}
 
+				/// Store a value under this key into the provided storage instance; this can take any reference
+				/// type that derefs to `T` (and has `Encode` implemented).
+				/// Store a value under this key into the provided storage instance.
+				fn insert_ref<Arg, S>(key: &#kty, val: &Arg, storage: &mut S)
+				where
+					#typ: AsRef<Arg>,
+					Arg: ?Sized + #scrate::codec::Encode,
+					S: #scrate::HashedStorage<#scrate::#hasher>
+				{
+					use self::#inner_module::Utils;
+
+					let key_for = &*#as_map::key_for(key);
+					let linkage = match Self::read_with_linkage(storage, key_for) {
+						// overwrite but reuse existing linkage
+						Some((_data, linkage)) => linkage,
+						// create new linkage
+						None => Self::new_head_linkage(storage, key),
+					};
+					storage.put(key_for, &(val, linkage))
+				}
+
 				/// Mutate the value under a key
 				fn mutate<R, F, S>(key: &#kty, f: F, storage: &mut S) -> R
 				where

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

@@ -246,7 +246,7 @@ pub trait StorageMap<K: codec::Codec, V: codec::Codec> {
 	/// Store a value under this key into the provided storage instance; this can take any reference
 	/// type that derefs to `T` (and has `Encode` implemented).
 	/// Store a value under this key into the provided storage instance.
-	fn insert_ref<Arg: ?Sized + Encode, S: HashedStorage<Twox128>>(
+	fn insert_ref<Arg: ?Sized + Encode, S: HashedStorage<Self::Hasher>>(
 		key: &K,
 		val: &Arg,
 		storage: &mut S

substrate/srml/support/test/tests/instance.rs

@@ -27,7 +27,7 @@ use srml_support::{
 use inherents::{
 	ProvideInherent, InherentData, InherentIdentifier, RuntimeString, MakeFatalError
 };
-use srml_support::{StorageValue, StorageMap, StorageDoubleMap};
+use srml_support::{StorageValue, StorageMap, StorageDoubleMap, EnumerableStorageMap};
 use primitives::{H256, sr25519};
 
 mod system;
@@ -140,7 +140,7 @@ mod module2 {
 		trait Store for Module<T: Trait<I>, I: Instance=DefaultInstance> as Module2 {
 			pub Value config(value): T::Amount;
 			pub Map config(map): map u64 => u64;
-			pub LinkedMap config(linked_map): linked_map u64 => u64;
+			pub LinkedMap config(linked_map): linked_map u64 => Vec<u8>;
 			pub DoubleMap config(double_map): double_map u64, blake2_256(u64) => u64;
 		}
 	}
@@ -288,13 +288,13 @@ fn new_test_ext() -> runtime_io::TestExternalities<Blake2Hasher> {
 		module2: Some(module2::GenesisConfig {
 			value: 4,
 			map: vec![(0, 0)],
-			linked_map: vec![(0, 0)],
+			linked_map: vec![(0, vec![0])],
 			double_map: vec![(0, 0, 0)],
 		}),
 		module2_Instance1: Some(module2::GenesisConfig {
 			value: 4,
 			map: vec![(0, 0)],
-			linked_map: vec![(0, 0)],
+			linked_map: vec![(0, vec![0])],
 			double_map: vec![(0, 0, 0)],
 		}),
 		module2_Instance2: None,
@@ -388,15 +388,23 @@ fn storage_with_instance_basic_operation() {
 
 		assert_eq!(LinkedMap::exists(0), true);
 		assert_eq!(LinkedMap::exists(key), false);
-		LinkedMap::insert(key, 1);
-		assert_eq!(LinkedMap::get(key), 1);
-		assert_eq!(LinkedMap::take(key), 1);
-		assert_eq!(LinkedMap::get(key), 0);
-		LinkedMap::mutate(key, |a| *a=2);
-		assert_eq!(LinkedMap::get(key), 2);
+		LinkedMap::insert(key, vec![1]);
+		assert_eq!(LinkedMap::enumerate().count(), 2);
+		assert_eq!(LinkedMap::get(key), vec![1]);
+		assert_eq!(LinkedMap::take(key), vec![1]);
+		assert_eq!(LinkedMap::enumerate().count(), 1);
+		assert_eq!(LinkedMap::get(key), vec![]);
+		LinkedMap::mutate(key, |a| *a=vec![2]);
+		assert_eq!(LinkedMap::enumerate().count(), 2);
+		assert_eq!(LinkedMap::get(key), vec![2]);
 		LinkedMap::remove(key);
+		assert_eq!(LinkedMap::enumerate().count(), 1);
 		assert_eq!(LinkedMap::exists(key), false);
-		assert_eq!(LinkedMap::get(key), 0);
+		assert_eq!(LinkedMap::get(key), vec![]);
+		assert_eq!(LinkedMap::exists(key), false);
+		assert_eq!(LinkedMap::enumerate().count(), 1);
+		LinkedMap::insert_ref(key, &vec![1]);
+		assert_eq!(LinkedMap::enumerate().count(), 2);
 
 		let key1 = 1;
 		let key2 = 1;
@@ -454,7 +462,7 @@ const EXPECTED_METADATA: StorageMetadata = StorageMetadata {
 				ty: StorageEntryType::Map {
 					hasher: StorageHasher::Blake2_256,
 					key: DecodeDifferent::Encode("u64"),
-					value: DecodeDifferent::Encode("u64"),
+					value: DecodeDifferent::Encode("Vec<u8>"),
 					is_linked: true,
 				},
 				default: DecodeDifferent::Encode(