fixed a bug in a loop where the script would wait for a condition that was

supposed to be signalled by other threads which were no longer running.

scripts/dns-srv-enum.nse

@@ -167,10 +167,12 @@ action = function(host)
 	
 	local condvar = nmap.condvar(result)
 	repeat
-		condvar "wait"
 		for t in pairs(threads) do
 			if ( coroutine.status(t) == "dead" ) then threads[t] = nil end
 		end
+		if ( next(threads) ) then
+			condvar "wait"
+		end
 	until( next(threads) == nil )
 	
 	table.sort(result, function(a,b) return a.name < b.name end)