Bug 183732 [DataBinding] swallowing the exception in get/set value of the JavaBeanObservableValue
During the bidning of beans that have PropertyChangeSupport implemented but not properly initialized (i.e null), data binding "swallows" the NullPointerException only logging "Could not attach listener to".
tests/org.eclipse.jface.tests.databinding/src/org/eclipse/core/tests/internal/databinding/internal/beans/JavaBeanObservableValueTest.java
public void testGetPropertyDescriptor() throws Exception {
    	assertEquals(propertyDescriptor, observableValue.getPropertyDescriptor());
	}
    
    public void testRegistersListenerAfterFirstListenerIsAdded() throws Exception {
		assertFalse(bean.changeSupport.hasListeners(propertyName));
		observableValue.addValueChangeListener(new ValueChangeEventTracker());
		assertTrue(bean.changeSupport.hasListeners(propertyName));
	}
    
    public void testRemovesListenerAfterLastListenerIsRemoved() throws Exception {
    	ValueChangeEventTracker listener = new ValueChangeEventTracker();
		observableValue.addValueChangeListener(listener);
		
		assertTrue(bean.changeSupport.hasListeners(propertyName));
		observableValue.removeValueChangeListener(listener);
		assertFalse(bean.changeSupport.hasListeners(propertyName));
	}
    
    public void testFiresValueChangeEvents() throws Exception {
    	ValueChangeEventTracker listener = new ValueChangeEventTracker();
    	observableValue.addValueChangeListener(listener);
    	
    	assertEquals(0, listener.count);
    	bean.setValue(bean.getValue() + bean.getValue());
    	assertEquals(1, listener.count);
	}
}