Bug 173836 NPE was thrown when click "Preview " button quickly twice[00]
NPE was thrown when click "Preview " button quickly twice[00] Build number: 2.2.0.v20070212-0630 Steps to reproduce: 1.open attached report 2.click "Preview" button quickly twice Expected result: Report can be previewed properly Actual result: NPE was thrown in second preview Error log: see screen shot
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/presentation/aggregation/layout/FramesetFragment.java
{
	/**
	 * Override build method.
	 */
	protected void build( )
	{
		addChild( new ToolbarFragment( ) );
		addChild( new ReportFragment( ) );
	}
	/**
	 * Service provided by the fragment. This is the entry point of engine
	 * framgent. It generally includes a JSP page to render a certain part of
	 * web viewer.
	 * 
	 * @param request
	 *            incoming http request
	 * @param response
	 *            http response
	 * @exception ServletException
	 * @exception IOException
	 */
	public void service( HttpServletRequest request,
			HttpServletResponse response ) throws ServletException,
			IOException, BirtException
	{
		BaseAttributeBean attrBean = (BaseAttributeBean) request
				.getAttribute( IBirtConstants.ATTRIBUTE_BEAN );