Bug 35192 Dialog.applyDialogFont should protect itself against null arguments
RC2 Now that many plugins use this method to apply the dialog font to widgets the method should protect itself against null arguments. Normally clients create their widget tree in a method createControl and there are changes that the returned control might be null. Adding a statement Dialog.applyDialogFont (result) with result == null will result in new NPEs.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/Dialog.java
* @since 2.0
	 */
	public static final String DLG_IMG_MESSAGE_INFO = "dialog_messasge_info_image"; 
	/**
	 * Image registry key for info message image (value <code>"dialog_messasge_warning_image"</code>).
	 * @since 2.0
	 */
	public static final String DLG_IMG_MESSAGE_WARNING = "dialog_messasge_warning_image"; 
	/**
	 * Image registry key for info message image (value <code>"dialog_message_error_image"</code>).
	 * @since 2.0
	 */
	public static final String DLG_IMG_MESSAGE_ERROR = "dialog_message_error_image"; 
	static {
		ImageRegistry reg = JFaceResources.getImageRegistry();
		reg.put(DLG_IMG_INFO, ImageDescriptor.createFromFile(Dialog.class, "images/inform.gif")); 
		reg.put(DLG_IMG_QUESTION, ImageDescriptor.createFromFile(Dialog.class, "images/question.gif")); 
		reg.put(DLG_IMG_WARNING, ImageDescriptor.createFromFile(Dialog.class, "images/warning.gif")); 
		reg.put(DLG_IMG_ERROR, ImageDescriptor.createFromFile(Dialog.class, "images/error.gif")); 
		reg.put(DLG_IMG_MESSAGE_INFO, ImageDescriptor.createFromFile(Dialog.class, "images/message_info.gif")); 
		reg.put(DLG_IMG_MESSAGE_WARNING, ImageDescriptor.createFromFile(Dialog.class, "images/message_warning.gif")); 
		reg.put(DLG_IMG_MESSAGE_ERROR, ImageDescriptor.createFromFile(Dialog.class, "images/message_error.gif")); 
	}
	/**
	 * The dialog area; <code>null</code> until dialog is layed out.
	 */
	protected Control dialogArea;
	/**
	 * The button bar; <code>null</code> until dialog is layed out.
	 */