src/java.desktop/macosx/native/libawt_lwawt/awt/LWCToolkit.m

@@ -515,11 +515,11 @@
         isRunning = [[NSRunLoop currentRunLoop] runMode:(inAWT ? [JNFRunLoop javaRunLoopMode] : NSDefaultRunLoopMode)
                                              beforeDate:[NSDate dateWithTimeIntervalSinceNow:0.010]];
         if (processEvents) {
             //We do not spin a runloop here as date is nil, so does not matter which mode to use
             NSEvent *event;
-            if ((event = [NSApp nextEventMatchingMask:NSAnyEventMask
+            if ((event = [NSApp nextEventMatchingMask:(NSAnyEventMask & ~NSApplicationDefined)
                                            untilDate:nil
                                               inMode:NSDefaultRunLoopMode
                                              dequeue:YES]) != nil) {
                 [NSApp sendEvent:event];
             }