Be more thorough in blanking out methods grabbed off of an fp.

Lib/urllib/response.py

@@ -33,12 +33,15 @@ class addbase(object):
                                              id(self), self.fp)
 
     def close(self):
+        if self.fp:
+            self.fp.close()
+        self.fp = None
         self.read = None
         self.readline = None
         self.readlines = None
         self.fileno = None
-        if self.fp: self.fp.close()
-        self.fp = None
+        self.__iter__ = None
+        self.__next__ = None
 
     def __enter__(self):
         if self.fp is None: