Don't include :code by default in storage proofs (#5179)

* Don't include `:code` by default in storage proofs (#5060)

* Adds test to verify that the runtime currently is always contained in
the proof

* Start passing the runtime wasm code from the outside

* Fix compilation

* More build fixes

* Make the test work as expected now :)

* Last fixes

* Fixes benchmarks

* Review feedback

* Apply suggestions from code review

Co-Authored-By: Sergei Pepyakin <sergei@parity.io>

* Review feedback

* Fix compilation

Co-authored-by: Sergei Pepyakin <s.pepyakin@gmail.com>

* Fix compilation and change the way `RuntimeCode` works

* Fix tests

* Switch to `Cow`

Co-authored-by: Benjamin Kampmann <ben@gnunicorn.org>
Co-authored-by: Sergei Pepyakin <s.pepyakin@gmail.com>

substrate/client/block-builder/src/lib.rs

@@ -205,3 +205,41 @@ where
 		})
 	}
 }
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use sp_blockchain::HeaderBackend;
+	use sp_core::Blake2Hasher;
+	use sp_state_machine::Backend;
+	use substrate_test_runtime_client::{DefaultTestClientBuilderExt, TestClientBuilderExt};
+
+	#[test]
+	fn block_building_storage_proof_does_not_include_runtime_by_default() {
+		let builder = substrate_test_runtime_client::TestClientBuilder::new();
+		let backend = builder.backend();
+		let client = builder.build();
+
+		let block = BlockBuilder::new(
+			&client,
+			client.info().best_hash,
+			client.info().best_number,
+			RecordProof::Yes,
+			Default::default(),
+			&*backend,
+		).unwrap().build().unwrap();
+
+		let proof = block.proof.expect("Proof is build on request");
+
+		let backend = sp_state_machine::create_proof_check_backend::<Blake2Hasher>(
+			block.storage_changes.transaction_storage_root,
+			proof,
+		).unwrap();
+
+		assert!(
+			backend.storage(&sp_core::storage::well_known_keys::CODE)
+				.unwrap_err()
+				.contains("Database missing expected key"),
+		);
+	}
+}