RFR[8233307]: MulticastSocket getOption(IP_MULTICAST_IF) returns interface when not set

[Patrick Concannon]

Hi,


Could someone please review my fix and CSR for issue JDK-8233307 
'MulticastSocket getOption(IP_MULTICAST_IF) returns interface when not set'?

The IP_MULTICAST_IF socket option is specified to have an initial value 
of null to mean that the interface has not been set. However, if 
MulticastSocket.getOption(IP_MULTICAST_IF) is called when the interface 
is not set, it returns a dummy NetworkInterface.

This fix changes the getOption() method to return 'null' as specified 
instead of a dummy networkInterface.


bug: https://bugs.openjdk.java.net/browse/JDK-8233307

csr: https://bugs.openjdk.java.net/browse/JDK-8234811
webrev: http://cr.openjdk.java.net/~pconcannon/8233307/webrevs/webrev.01/




Kind regards,
Patrick