Bug 152586 [Properties view] Querying nonexistent project for properties causes NPE
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/properties/ResourcePropertySource.java
/**
     * The <code>ResourcePropertySource</code> implementation of this
     * <code>IPropertySource</code> method does nothing since all
     * properties are read-only.
     */
    public void resetPropertyValue(Object property) {
    }
    /**
     * The <code>ResourcePropertySource</code> implementation of this
     * <code>IPropertySource</code> method does nothing since all
     * properties are read-only.
     */
    public void setPropertyValue(Object name, Object value) {
    }
    /** 
     * Get the java.io.File equivalent of the passed
     * IFile. If the location does not exist then return
     * <code>null</code>
     * @param resource the resource to lookup
     * @return java.io.File or <code>null</code>.
     */
    protected File getFile(IResource resource) {
        IPath location = resource.getLocation();
        if (location == null) {
			return null;
		}
		return location.toFile();
    }
}