Issue #20059: urllib.parse raises ValueError on all invalid ports.

Patch by Martin Panter.

Lib/urllib/parse.py

@@ -156,9 +156,8 @@ class _NetlocResultMixinBase(object):
         port = self._hostinfo[1]
         if port is not None:
             port = int(port, 10)
-            # Return None on an illegal port
             if not ( 0 <= port <= 65535):
-                return None
+                raise ValueError("Port out of range 0-65535")
         return port