Prevent the present windows filter box from appearing when an unbound

key on the keyboard is pressed. Patch by Jacopo De Simoi. This should
really be done somewhere further up the chain but as it's a temporary
workaround anyway I guess it doesn't matter.
BUG: 178547

svn path=/trunk/KDE/kdebase/workspace/; revision=902453

effects/presentwindows.cpp

@@ -368,6 +368,8 @@ void PresentWindowsEffect::grabbedKeyboardEvent( QKeyEvent *e )
                 return;
             case Qt::Key_Tab:
                 return; // Nothing at the moment
+            case 0:
+                return; // HACK: Workaround for Qt bug on unbound keys (#178547)
             default:
                 if( !e->text().isEmpty() )
                     {