If we have no socket or a closed socket when trying to write overflow queue

messages, treat that like a network failure which will clear out that queue and
shutdown the connection. Overflow queues are only meant to handle sockets that
are backed up, not closed or non-existent.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5813 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/presents/server/net/ConnectionManager.java

@@ -1121,8 +1121,8 @@ public class ConnectionManager extends LoopingThread
             if (_partial != null) {
                 // if our outgoing channel is still not ready, then bail immediately
                 SocketChannel sochan = conn.getChannel();
-                if (!sochan.isConnected()) {
+                if (sochan == null || !sochan.isConnected()) {
-                    return false;
+                    throw new IOException("Connection unavailable for overflow write");
                 }
 
                 // write all we can of our partial buffer