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
protected Control buttonBar;
	/**
	 * Collection of buttons created by the <code>createButton</code> method.
	 */
	private HashMap buttons = new HashMap();
	/**
	 * Font metrics to use for determining pixel sizes.
	 */
	private FontMetrics fontMetrics;
	/**
	 * Number of horizontal dialog units per character, value <code>4</code>. 
	 */
	private static final int HORIZONTAL_DIALOG_UNIT_PER_CHAR = 4;
	/**
	 * Number of vertical dialog units per character, value <code>8</code>. 
	 */
	private static final int VERTICAL_DIALOG_UNITS_PER_CHAR = 8;
	/**
	 * Returns the number of pixels corresponding to the
	 * height of the given number of characters.
	 * <p>
	 * The required <code>FontMetrics</code> parameter may be created in the 
	 * following way:
	 * <code>
	 * 	GC gc = new GC(control);
	 *	gc.setFont(control.getFont());
	 *	fontMetrics = gc.getFontMetrics();
	 *	gc.dispose();
	 * </code>
	 * </p>