Fail in Connection#write_frames if @framer is nil.

Author: ioquatix

lib/protocol/http2/connection.rb

@@ -211,7 +211,11 @@ def write_frame(frame)
 			end
 
 			def write_frames
-				yield @framer
+				if @framer
+					yield @framer
+				else
+					raise EOFError, "Connection closed!"
+				end
 			end
 
 			def update_local_settings(changes)

test/protocol/http2/connection.rb

@@ -65,6 +65,15 @@
 			connection.read_frame
 		end.to raise_exception(Protocol::HPACK::Error)
 	end
+	
+	it "can't write frames to a closed connection" do
+		connection.close
+		
+		expect do
+			connection.write_frames do |framer|
+			end
+		end.to raise_exception(EOFError, message: be =~ /Connection closed/)
+	end
 end
 
 with 'client and server' do