remove unrelated code

core/blockchain.go

@@ -445,11 +445,7 @@ func (bc *BlockChain) repair(head **types.Block) error {
 			return nil
 		}
 		// Otherwise rewind one block and recheck state availability there
-		block := bc.GetBlock((*head).ParentHash(), (*head).NumberU64()-1)
-		if block == nil {
-			return fmt.Errorf("failed to repair block, can not get block at height %d", (*head).NumberU64())
-		}
-		(*head) = block
+		(*head) = bc.GetBlock((*head).ParentHash(), (*head).NumberU64()-1)
 	}
 }
 

rpc/ipc.go

@@ -24,7 +24,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/netutil"
 )
 
-// ServeListener accepts connections on l, serving IPC-RPC on them.
+// ServeListener accepts connections on l, serving JSON-RPC on them.
 func (srv *Server) ServeListener(l net.Listener) error {
 	for {
 		conn, err := l.Accept()