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
{
			overwrite = true;
		}
		return overwrite;
	}
	/***************************************************************************
	 * protected routines
	 **************************************************************************/
	/**
	 * Checks if a given file name is a relative path.
	 * 
	 * @param fileName
	 *            The file name.
	 * @return A <code>boolean</code> value indicating if the file name is a
	 *         relative path or not.
	 */
	public static boolean isRelativePath( String fileName )
	{
		return !new File( fileName ).isAbsolute( );
	}
	/**
	 * Check whether report parameter exists in the url.
	 * 
	 * @param request
	 *            http request
	 * @param name
	 *            parameter name
	 * @return whether report parameter exists in the url
	 */
	public static boolean isReportParameterExist( HttpServletRequest request,