NPE in LookupDiscovery when list of interfaces has null entry

I recently swapped harddrives between two identical machines to see if that 
would expose an suspected problem with one of the drives.  These are linux 
machines, and the /etc/sysconfig/network-scripts/ifcfg-eth0 files had MAC 
addresses in them.  Linux (Fedora-8) noted that these MAC addresses didn't jive 
with what it could see on the machine the drives were swapped to, and the 
interfaces came up as eth1 instead.  I had a set of discovery interfaces 
specified in the config using

multicastInterfaces = new java.net.NetworkInterface[] {
	java.net.NetworkInterface.getByName("lo"),
	java.net.NetworkInterface.getByName("eth0")
};

This caused a null pointer to be in the array, which created some issues with 
the nics[i].getName() references in AnnouncementListener constructor, near line 
1030. I've made logging changes and other things in my copy of this class, so 
here is the associated code showing the conditional check I put into the loop.

Gregg Wonderly
--------------------------------

             switch(nicsToUse) {
                 case NICS_USE_ALL:
                     /* Using all interfaces. Skip (but report) any interfaces
                      * that are "bad" or not configured for multicast.
                      */
                     for(int i=0;i<nics.length;i++) {
			if( nics[i] == null ) {
				logger.warning("nic entry null at #"+i);
				continue;
			}
                         try {
                             sock.setNetworkInterface(nics[i]);
                             sock.joinGroup(Constants.getAnnouncementAddress());
                         } catch(IOException e) {
                             if(retryNics == null) {
                                 retryNics = new ArrayList(nics.length);
                             }//endif
                             retryNics.add(nics[i]);
							Logger logger = 
Logger.getLogger(LookupDiscovery.class.getName()+".multicast"+"."+nics[i].getName());
                             if( logger.isLoggable(Levels.HANDLED) ) {
                                 LogRecord logRec =
                                   new LogRecord(Levels.HANDLED,
												"a network interface "
                                                 +"is bad or not configured "
                                                 +"for multicast: {0}");
                                 logRec.setParameters(new Object[]{nics[i]});
								logRec.setLoggerName( logger.getName() );
                                 logRec.setThrown(e);
                                 logger.log(logRec);
                             }//endif
                         }
                     }//end loop
                     break;
                 case NICS_USE_LIST:
                     /* Using a configured list of specific interfaces. Skip
                      * (but report) any interfaces that are "bad" or not
                      * configured for multicast.
                      */
                     for(int i=0;i<nics.length;i++) {
  			if( nics[i] == null ) {
				logger.fine("nic entry null at #"+i);
				continue;
			}
                        try {
                             sock.setNetworkInterface(nics[i]);
                             sock.joinGroup(Constants.getAnnouncementAddress());
                         } catch(IOException e) {
                             if(retryNics == null) {
                                 retryNics = new ArrayList(nics.length);
                             }//endif
                             retryNics.add(nics[i]);
							Logger logger = 
Logger.getLogger(LookupDiscovery.class.getName()+"."+nics[i].getName()+".multicast");
                              if( logger.isLoggable(Level.SEVERE) ) {
                                 LogRecord logRec =
                                   new LogRecord(Level.SEVERE,
                                                 "a network interface is bad or "
                                                 +"not configured for "
                                                 +"multicast: {0}");
                                 logRec.setParameters(new Object[]{nics[i]});
                                 logRec.setThrown(e);
								logRec.setLoggerName( logger.getName() );
                                 logger.log(logRec);
                             }//endif
                         }
                     }//end loop
                     break;

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