fix send_message_worst_case (paritytech#571)

bridges/bin/rialto/runtime/src/lib.rs

@@ -830,7 +830,7 @@ impl_runtime_apis! {
 				}
 
 				fn prepare_message(
-					params: MessageLaneMessageParams,
+					params: MessageLaneMessageParams<Self::AccountId>,
 				) -> (millau_messages::ToMillauMessagePayload, Balance) {
 					use crate::millau_messages::{ToMillauMessagePayload, WithMillauMessageBridge};
 					use bridge_runtime_common::messages;
@@ -843,7 +843,9 @@ impl_runtime_apis! {
 							* sp_std::cmp::min(factor, WORST_MESSAGE_SIZE_FACTOR),
 					};
 					let message_payload = vec![0; message_size as usize];
-					let dispatch_origin = pallet_bridge_call_dispatch::CallOrigin::SourceAccount(Default::default());
+					let dispatch_origin = pallet_bridge_call_dispatch::CallOrigin::SourceAccount(
+						params.sender_account,
+					);
 
 					let message = ToMillauMessagePayload {
 						spec_version: 0,

bridges/modules/message-lane/src/benchmarking.rs

@@ -34,19 +34,21 @@ const SEED: u32 = 0;
 pub struct Module<T: Trait<I>, I: crate::Instance>(crate::Module<T, I>);
 
 /// Benchmark-specific message parameters.
-pub struct MessageParams {
+pub struct MessageParams<ThisAccountId> {
 	/// Size factor of the message payload. Message payload grows with every factor
 	/// increment. Zero is the smallest possible message and the `WORST_MESSAGE_SIZE_FACTOR` is
 	/// largest possible message.
 	pub size_factor: u32,
+	/// Message sender account.
+	pub sender_account: ThisAccountId,
 }
 
 /// Trait that must be implemented by runtime.
 pub trait Trait<I: Instance>: crate::Trait<I> {
 	/// Create given account and give it enough balance for test purposes.
 	fn endow_account(account: &Self::AccountId);
 	/// Prepare message to send over lane.
-	fn prepare_message(params: MessageParams) -> (Self::OutboundPayload, Self::OutboundMessageFee);
+	fn prepare_message(params: MessageParams<Self::AccountId>) -> (Self::OutboundPayload, Self::OutboundMessageFee);
 }
 
 benchmarks_instance! {
@@ -70,7 +72,10 @@ benchmarks_instance! {
 		}
 		confirm_message_delivery::<T, I>(T::MaxMessagesToPruneAtOnce::get());
 
-		let (payload, fee) = T::prepare_message(MessageParams { size_factor: WORST_MESSAGE_SIZE_FACTOR });
+		let (payload, fee) = T::prepare_message(MessageParams {
+			size_factor: WORST_MESSAGE_SIZE_FACTOR,
+			sender_account: sender.clone(),
+		});
 	}: send_message(RawOrigin::Signed(sender), lane_id, payload, fee)
 }