Bug 147407 Preview the attached report in the web viewer first time and then click the TOC button will cause NPE error
Description: It just can be reprouduced at first time preview. Step to reproduce: 1. please use attach report file 2. preview it in the web viewer 3. click the "Toggle table of contents" button Actual result: As the atteched screenshot shows,There is a NPE error.And if you preview it in the Web viewer again, the phenomenon is disappear.But reopen the eclipse and preview it at first time, it will be occured.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
public static final String SERVLET_PATH_PREVIEW = "/preview"; 
	/**
	 * Servlet path for frameset model.
	 */
	public static final String SERVLET_PATH_FRAMESET = "/frameset"; 
	/**
	 * Servlet path for running model.
	 */
	public static final String SERVLET_PATH_RUN = "/run"; 
	/**
	 * Servlet path for running model.
	 */
	public static final String SERVLET_PATH_DOWNLOAD = "/download"; 
	
	/**
	 * URL parameter name that gives the report design name.
	 */
	public static final String PARAM_REPORT = "__report"; 
	/**
	 * URL parameter name that gives the report document name.
	 */
	public static final String PARAM_REPORT_DOCUMENT = "__document"; 
	/**
	 * URL parameter name that gives the format to display the report, html or
	 * pdf.
	 */
	public static final String PARAM_FORMAT = "__format"; 
	/**
	 * Format parameter constants to display the report in html.
	 */