Set uncles inherent (#3317)

* Include uncles

* Filter missing uncles

* Moved inherent registration to a new crate

* Ignore invalid inherent encoding

substrate/core/client/src/client.rs

@@ -170,6 +170,13 @@ pub trait BlockBody<Block: BlockT> {
 	) -> error::Result<Option<Vec<<Block as BlockT>::Extrinsic>>>;
 }
 
+/// Provide a list of potential uncle headers for a given block.
+pub trait ProvideUncles<Block: BlockT> {
+	/// Gets the uncles of the block with `target_hash` going back `max_generation` ancestors.
+	fn uncles(&self, target_hash: Block::Hash, max_generation: NumberFor<Block>)
+		-> error::Result<Vec<Block::Header>>;
+}
+
 /// Client info
 #[derive(Debug)]
 pub struct ClientInfo<Block: BlockT> {
@@ -1329,7 +1336,7 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
 			ancestor_hash = *current.parent_hash();
 			ancestor = load_header(ancestor_hash)?;
 		}
-
+		trace!("Collected {} uncles", uncles.len());
 		Ok(uncles)
 	}
 
@@ -1353,6 +1360,20 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
 	}
 }
 
+impl<B, E, Block, RA> ProvideUncles<Block> for Client<B, E, Block, RA> where
+	B: backend::Backend<Block, Blake2Hasher>,
+	E: CallExecutor<Block, Blake2Hasher>,
+	Block: BlockT<Hash=H256>,
+{
+	fn uncles(&self, target_hash: Block::Hash, max_generation: NumberFor<Block>) -> error::Result<Vec<Block::Header>> {
+		Ok(Client::uncles(self, target_hash, max_generation)?
+			.into_iter()
+			.filter_map(|hash| Client::header(self, &BlockId::Hash(hash)).unwrap_or(None))
+			.collect()
+		)
+	}
+}
+
 impl<B, E, Block, RA> ChainHeaderBackend<Block> for Client<B, E, Block, RA> where
 	B: backend::Backend<Block, Blake2Hasher>,
 	E: CallExecutor<Block, Blake2Hasher> + Send + Sync,

substrate/core/client/src/lib.rs

@@ -115,7 +115,7 @@ pub use crate::client::{
 	new_in_mem,
 	BlockBody, BlockStatus, ImportNotifications, FinalityNotifications, BlockchainEvents,
 	BlockImportNotification, Client, ClientInfo, ExecutionStrategies, FinalityNotification,
-	LongestChain, BlockOf,
+	LongestChain, BlockOf, ProvideUncles,
 	utils,
 };
 #[cfg(feature = "std")]