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/context/ViewerAttributeBean.java
{
	/**
	 * Viewer preview max rows limited
	 */
	private int maxRows;
	/**
	 * Report parameters as string map
	 */
	private Map parametersAsString = null;
	/**
	 * Report parameter definitions List
	 */
	private Collection parameterDefList = null;
	/**
	 * Display Text of Select Parameters
	 */
	private Map displayTexts = null;
	/**
	 * Module Options
	 */
	private Map moduleOptions = null;
	/**
	 * If document generated completely
	 */
	private boolean isDocumentProcessing = false;
	/**
	 * Request Type
	 */