Allow fields to be returned so they can be used simultaneously.

src/block.rs

@@ -8,6 +8,14 @@ pub struct Entry {
 	receipt: Receipt,
 }
 
+/// A set of fields that are publicly alterable. 
+pub struct BlockRefMut<'a> {
+	pub header: &'a Header,
+	pub state: &'a mut State,
+	pub archive: &'a Vec<Entry>,
+	pub uncles: &'a Vec<Header>,
+}
+
 /// Internal type for a block's common elements.
 pub struct Block {
 	header: Header,
@@ -32,7 +40,14 @@ impl Block {
 		}
 	}
 
-	pub fn state_mut(&mut self) -> &mut State { &mut self.state }
+	pub fn fields(&mut self) -> BlockRefMut {
+		BlockRefMut {
+			header: &self.header,
+			state: &mut self.state,
+			archive: &self.archive,
+			uncles: &self.uncles,
+		}
+	}
 }
 
 /// Trait for a object that is_a `Block`.

src/ethereum/ethash.rs

@@ -22,8 +22,16 @@ impl Engine for Ethash {
 
 	/// Apply the block reward on finalisation of the block.
 	fn on_close_block(&self, block: &mut Block) {
-		let a = block.header().author.clone();
-		block.state_mut().add_balance(&a, &decode(&self.spec().engine_params.get("blockReward").unwrap()));
+		let reward = self.spec().engine_params.get("blockReward").map(|a| decode(&a)).unwrap_or(U256::from(0u64));
+		let fields = block.fields();
+		let author = &fields.header.author;
+		fields.state.add_balance(author, &reward);
+/*
+		let uncle_authors = block.uncles.iter().map(|u| u.author().clone()).collect();
+		for a in uncle_authors {
+			block.state_mut().addBalance(a, _blockReward * (8 + i.number() - m_currentBlock.number()) / 8);
+			r += _blockReward / 32;
+		}*/
 	}
 }