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 void setButtonLayoutFormData(Button button) {
		FormData data = new FormData();
		data.height =
			convertVerticalDLUsToPixels(IDialogConstants.BUTTON_HEIGHT);
		int widthHint =
			convertHorizontalDLUsToPixels(IDialogConstants.BUTTON_WIDTH);
		data.width =
			Math.max(
				widthHint,
				button.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).x);
		button.setLayoutData(data);
	}
	/**
	 * @see org.eclipse.jface.window.Window#close()
	 */
	public boolean close() {
		boolean returnValue = super.close();
		if (returnValue) {
			buttons = new HashMap();
			buttonBar = null;
			dialogArea = null;
		}
		return returnValue;
	}
	/**
	 * Applies the dialog font to all controls that currently have the default
	 * font.
	 * 
	 * @param control the control to apply the font to. Font will also be applied to