Reverted Kyle Centers mistaken patch that removed a _currentContext->valid() that was actually required.
Reverted Kyle Centers mistaken patch that removed a _currentContext->valid() that was actually required.


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