Emit a protocol error when a closing frame has a 1-byte payload.

lib/websocket/driver/hybi.rb

@@ -355,8 +355,8 @@ module WebSocket
             @message << frame
 
           when OPCODES[:close] then
-            code   = (bytesize >= 2) ? 256 * bytes[0] + bytes[1] : DEFAULT_ERROR_CODE
-            reason = (bytesize > 2)  ? Driver.encode(bytes[2..-1] || [], :utf8) : ''
+            code   = (bytesize >= 2) ? payload.unpack(PACK_FORMATS[2]).first : nil
+            reason = (bytesize > 2)  ? Driver.encode(bytes[2..-1] || [], :utf8) : nil
 
             unless (bytesize == 0) or
                    (code && code >= MIN_RESERVED_ERROR && code <= MAX_RESERVED_ERROR) or
@@ -368,7 +368,7 @@ module WebSocket
               code = ERRORS[:protocol_error]
             end
 
-            shutdown(code, reason)
+            shutdown(code || DEFAULT_ERROR_CODE, reason || '')
 
           when OPCODES[:ping] then
             frame(payload, :pong)

spec/websocket/driver/hybi_spec.rb

@@ -563,6 +563,20 @@ describe WebSocket::Driver::Hybi do
       end
     end
 
+    describe "receiving a close frame with a too-short payload" do
+      before do
+        driver.parse [0x88, 0x01, 0x03].pack("C*")
+      end
+
+      it "triggers the onclose event with a protocol error" do
+        expect(@close).to eq [1002, ""]
+      end
+
+      it "changes the state to :closed" do
+        expect(driver.state).to eq :closed
+      end
+    end
+
     describe "receiving a close frame with no code" do
       before do
         driver.parse [0x88, 0x00].pack("C*")