Added extra check to prevent calling frame() when the window has been closed.
Added extra check to prevent calling frame() when the window has been closed.


tomasthoresen/osg,openscenegraph/osg,marchelbling/osg,scrawl/osg,tomasthoresen/osg,scrawl/osg,artoolkit/osg,jtorresfabra/osg,jtorresfabra/osg,jtorresfabra/osg,scrawl/osg,openscenegraph/osg,artoolkit/osg,openscenegraph/osg,artoolkit/osg,marchelbling/osg,scrawl/osg,jtorresfabra/osg,openscenegraph/osg,marchelbling/osg,artoolkit/osg,marchelbling/osg,tomasthoresen/osg,tomasthoresen/osg