Add Refund submission deposit

precompiles/referenda/Referenda.sol

@@ -83,16 +83,17 @@ interface Referenda {
     /// @param  index The index of a closed referendum with decision deposit still locked
     function refundDecisionDeposit(uint32 index) external;
 
+    /// @dev Refund the Submission Deposit for a closed referendum back to the depositor
+    /// @custom:selector c28307ca
+    /// @param  index The index of a closed referendum with submission deposit still locked
+    function refundSubmissionDeposit(uint32 index) external;
+
     /// @dev A referenda has been submitted at a given block
     /// @custom:selector e02a819ecfc92874b5016c6a0e26f56a5cb08771f32ab818bf548d84ca3ae94d
     /// @param trackId uint16 The trackId
     /// @param blockNumber uint32 Block number at which it was set to be submitted
     /// @param hash bytes32 The hash of the proposal preimage
-    event SubmittedAt(
-        uint16 indexed trackId,
-        uint32 blockNumber,
-        bytes32 hash
-    );
+    event SubmittedAt(uint16 indexed trackId, uint32 blockNumber, bytes32 hash);
 
     /// @dev A referenda has been submitted after a given block
     /// @custom:selector a5117efbf0f4aa9e08dd135e69aa8ee4978f99fca86fc5154b5bd1b363eafdcf
@@ -108,14 +109,10 @@ interface Referenda {
     /// @dev Decision Deposit for a referendum has been placed
     /// @custom:selector 87e691fb2e6a679435f578d43cd67e1af825294e56064a9de0522b312b8e9a60
     /// @param index uint32 The index of the ongoing referendum that is not yet deciding
-    event DecisionDepositPlaced(
-        uint32 index
-    );
+    event DecisionDepositPlaced(uint32 index);
 
     /// @dev Decision Deposit for a closed referendum has been refunded
     /// @custom:selector 61f241739b215680a33261f1dee7646d0e840d5e498c1142c1a534987d9b8ed8
     /// @param index uint32 The index of the closed referendum
-    event DecisionDepositRefunded(
-        uint32 index
-    );
+    event DecisionDepositRefunded(uint32 index);
 }

precompiles/referenda/src/lib.rs

@@ -411,4 +411,18 @@ where
 		event.record(handle)?;
 		Ok(())
 	}
+
+	/// Refund the Submission Deposit for a closed referendum back to the depositor.
+	///
+	/// Parameters:
+	/// * index: The index of a closed referendum whose Submission Deposit has not yet been refunded.
+	#[precompile::public("refundSubmissionDeposit(uint32)")]
+	fn refund_submission_deposit(handle: &mut impl PrecompileHandle, index: u32) -> EvmResult {
+		let origin = Runtime::AddressMapping::into_account_id(handle.context().caller);
+
+		let call = ReferendaCall::<Runtime>::refund_submission_deposit { index }.into();
+
+		<RuntimeHelper<Runtime>>::try_dispatch(handle, Some(origin).into(), call)?;
+		Ok(())
+	}
 }