Fix build.

ethcore/src/client/client.rs

@@ -711,16 +711,6 @@ impl Client {
 		}
 	}
 
-	/// Look up the block number for the given block ID.
-	pub fn block_number(&self, id: BlockId) -> Option<BlockNumber> {
-		match id {
-			BlockId::Number(number) => Some(number),
-			BlockId::Hash(ref hash) => self.chain.read().block_number(hash),
-			BlockId::Earliest => Some(0),
-			BlockId::Latest | BlockId::Pending => Some(self.chain.read().best_block_number()),
-		}
-	}
-
 	/// Take a snapshot at the given block.
 	/// If the ID given is "latest", this will default to 1000 blocks behind.
 	pub fn take_snapshot<W: snapshot_io::SnapshotWriter + Send>(&self, writer: W, at: BlockId, p: &snapshot::Progress) -> Result<(), EthcoreError> {
@@ -946,6 +936,15 @@ impl BlockChainClient for Client {
 		Self::block_hash(&chain, id).and_then(|hash| chain.block_header_data(&hash))
 	}
 
+	fn block_number(&self, id: BlockId) -> Option<BlockNumber> {
+		match id {
+			BlockId::Number(number) => Some(number),
+			BlockId::Hash(ref hash) => self.chain.read().block_number(hash),
+			BlockId::Earliest => Some(0),
+			BlockId::Latest | BlockId::Pending => Some(self.chain.read().best_block_number()),
+		}
+	}
+
 	fn block_body(&self, id: BlockId) -> Option<Bytes> {
 		let chain = self.chain.read();
 		Self::block_hash(&chain, id).and_then(|hash| chain.block_body(&hash))

ethcore/src/client/test_client.rs

@@ -473,6 +473,10 @@ impl BlockChainClient for TestBlockChainClient {
 		self.block_hash(id).and_then(|hash| self.blocks.read().get(&hash).map(|r| Rlp::new(r).at(0).as_raw().to_vec()))
 	}
 
+	fn block_number(&self, _id: BlockId) -> Option<BlockNumber> {
+		unimplemented!()
+	}
+
 	fn block_body(&self, id: BlockId) -> Option<Bytes> {
 		self.block_hash(id).and_then(|hash| self.blocks.read().get(&hash).map(|r| {
 			let mut stream = RlpStream::new_list(2);

ethcore/src/client/traits.rs

@@ -52,6 +52,9 @@ pub trait BlockChainClient : Sync + Send {
 	/// Get raw block header data by block id.
 	fn block_header(&self, id: BlockId) -> Option<Bytes>;
 
+	/// Look up the block number for the given block ID.
+	fn block_number(&self, id: BlockId) -> Option<BlockNumber>;
+	
 	/// Get raw block body data by block id.
 	/// Block body is an RLP list of two items: uncles and transactions.
 	fn block_body(&self, id: BlockId) -> Option<Bytes>;