--- a/eric6/Cooperation/Connection.py	Sun Apr 11 16:53:48 2021 +0200
+++ b/eric6/Cooperation/Connection.py	Sun Apr 11 18:45:10 2021 +0200
@@ -240,9 +240,11 @@
             self.readyForUse.emit()
         
         while self.bytesAvailable():
-            if self.__currentDataType == Connection.Undefined:
-                if not self.__readProtocolHeader():
-                    return
+            if (
+                self.__currentDataType == Connection.Undefined and
+                not self.__readProtocolHeader()
+            ):
+                return
             
             if not self.__hasEnoughData():
                 return