Block Request Judgement Calls on Polkadot (#338)

This change blocks `request_judgement` calls on the Relay Chain. This is
because requesting judgement reserves some funds to be sent to the
registrar. This complicates migration to the People Chain and requires
either breaking changes to the Identity pallet or phantom reserved
funds. Blocking new requests (but allowing judgements and cancellations)
prior to the migration will be simpler and lower risk.

CHANGELOG.md

@@ -14,6 +14,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Changed
 
 - Transaction payments work via new `fungible` trait implementation ([polkadot-fellows/runtimes#332](https://github.com/polkadot-fellows/runtimes/pull/332))
+- Block `request_judgement` calls on the Relay Chain ([polkadot-fellows/runtimes#338](https://github.com/polkadot-fellows/runtimes/pull/338))
 
 ### Fixed
 

relay/polkadot/src/lib.rs

@@ -61,8 +61,8 @@ use frame_support::{
 	genesis_builder_helper::{build_config, create_default_config},
 	parameter_types,
 	traits::{
-		fungible::HoldConsideration, ConstU32, EitherOf, EitherOfDiverse, Everything, Get,
-		InstanceFilter, KeyOwnerProofSystem, LinearStoragePrice, PrivilegeCmp, ProcessMessage,
+		fungible::HoldConsideration, ConstU32, Contains, EitherOf, EitherOfDiverse, EverythingBut,
+		Get, InstanceFilter, KeyOwnerProofSystem, LinearStoragePrice, PrivilegeCmp, ProcessMessage,
 		ProcessMessageError, WithdrawReasons,
 	},
 	weights::{ConstantMultiplier, WeightMeter},
@@ -175,8 +175,16 @@ parameter_types! {
 	pub const SS58Prefix: u8 = 0;
 }
 
+/// A type to identify `identity::request_judgement` calls.
+pub struct IsIdentityJudgementRequestCall;
+impl Contains<RuntimeCall> for IsIdentityJudgementRequestCall {
+	fn contains(c: &RuntimeCall) -> bool {
+		matches!(c, RuntimeCall::Identity(pallet_identity::Call::request_judgement { .. }))
+	}
+}
+
 impl frame_system::Config for Runtime {
-	type BaseCallFilter = Everything;
+	type BaseCallFilter = EverythingBut<IsIdentityJudgementRequestCall>;
 	type BlockWeights = BlockWeights;
 	type BlockLength = BlockLength;
 	type RuntimeOrigin = RuntimeOrigin;