In researching 5104197, it was found that a subclass implementation of
ObjectOutputStream.PutField:

    com.sun.corba.se.impl.io.OutputStreamHook$HookPutFields

did not accommodate nulls for the Object 'value' argument in the
HookPutFields.put(String name, Object value) method. The javadoc
specification for PutField.put does not clearly indicate what should
be done about a null 'value' argument.

The intent is for null to be allowed -
the javadoc specification should be clarified accordingly.