Bug 152586 [Properties view] Querying nonexistent project for properties causes NPE
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/properties/ResourcePropertySource.java
* Returns whether the given resource is a linked resource bound 
     * to a path variable.
     * 
     * @param resource resource to test
     * @return boolean <code>true</code> the given resource is a linked 
     * 	resource bound to a path variable. <code>false</code> the given 
     * 	resource is either not a linked resource or it is not using a
     * 	path variable.  
     */
    private boolean isPathVariable(IResource resource) {
        if (!resource.isLinked()) {
			return false;
		}
        IPath resolvedLocation = resource.getLocation();
        if (resolvedLocation == null) {
            
            return true;
        }
        IPath rawLocation = resource.getRawLocation();
        if (resolvedLocation.equals(rawLocation)) {
			return false;
		}
        return true;
    }
    /* (non-Javadoc)
     * Method declared on IPropertySource.
     */
    public boolean isPropertySet(Object property) {
        return false;
    }