temporarly move extrinsics shuffling to client side. When block object

is passed to runtime code (execute_block_with_context) the block struct
is serialized & deserialized. In the same time we dont include
Header::seed field in serialization & deserialization because it breaks
JS api compatibility. That will be address in the future.

client/service/src/client/client.rs

@@ -37,7 +37,7 @@ use sp_runtime::{
 	Justification, BuildStorage,
 	generic::{BlockId, SignedBlock, DigestItem},
 	traits::{
-		Block as BlockT, Header as HeaderT, Zero, NumberFor,
+		Hash, Block as BlockT, Header as HeaderT, Zero, NumberFor,
 		HashFor, SaturatedConversion, One, DigestFor, UniqueSaturatedInto,
 	},
 };
@@ -897,10 +897,19 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
 						let prev_header = self.backend.blockchain().header(BlockId::Hash(*parent_hash)).unwrap().unwrap();
 						header.set_extrinsics_root(*prev_header.extrinsics_root());
 
+
+						// temporarly shuffle extrinsics here as we cannot pass shuffling seed to
+						// runtime easily
+						let shuffled_extrinsics = extrinsic_shuffler::shuffle::<Block,Self>(&runtime_api, &at, previous_block_extrinsics, seed);
+						// temporarly update extrinsics_root that stores hash of ordered extrinsics so it can be
+						// validated properly
+						let trie_root = HashFor::<Block>::ordered_trie_root(shuffled_extrinsics.iter().map(codec::Encode::encode).collect());
+						header.set_extrinsics_root(trie_root);
+
 						runtime_api.execute_block_with_context(
 							&at,
 							execution_context,
-							Block::new(header, previous_block_extrinsics),
+							Block::new(header.clone(), shuffled_extrinsics),
 						)?;
 					}
 					None => {

frame/executive/src/lib.rs

@@ -297,7 +297,7 @@ where
 	}
 
 	/// Actually execute all transitions for `block`.
-	pub fn execute_block(block: Block, info: Vec<Option<AccountId32>>) {
+	pub fn execute_block(block: Block, _info: Vec<Option<AccountId32>>) {
 		sp_io::init_tracing();
 		sp_tracing::within_span! {
 			sp_tracing::info_span!( "execute_block", ?block);
@@ -311,14 +311,20 @@ where
 
 			// execute extrinsics
 			let (header, extrinsics) = block.deconstruct();
-			let extrinsics_with_author: Vec<(Option<_>,_)> = info.into_iter().zip(extrinsics.into_iter()).collect();
-
-			let mut seed: [u8;32] = Default::default();
-			seed.copy_from_slice(header.seed().as_ref());
-			let shuffled_extrinsics = shuffle_using_seed::<Block>(extrinsics_with_author, seed);
-
-			Self::execute_extrinsics_with_book_keeping(shuffled_extrinsics, *header.number()); 
 
+			// TODO: shuffling temporarly moved to native code. 
+			// Motivation:
+			// There is no easy way to pass seed from native to wasm runtime. Shuffling at
+			// runtime can be reverted once we have fully working Header::seed field
+			// (including serialization & deserialization that is currently missing)
+
+			// let extrinsics_with_author: Vec<(Option<_>,_)> = info.into_iter().zip(extrinsics.into_iter()).collect();
+			// let mut seed: [u8;32] = Default::default();
+			// seed.copy_from_slice(header.seed().as_ref());
+			// let shuffled_extrinsics = shuffle_using_seed::<Block>(extrinsics_with_author, seed);
+			// Self::execute_extrinsics_with_book_keeping(shuffled_extrinsics, *header.number()); 
+
+			Self::execute_extrinsics_with_book_keeping(extrinsics, *header.number()); 
 			if !signature_batching.verify() {
 				panic!("Signature verification failed.");
 			}