Bug 198917 set __parameterpage to false for required parameter will cause wrong Exception[0705]
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/EngineTask.java
{
		String format = RenderOption.OUTPUT_FORMAT_HTML;;
		if ( renderOptions != null )
		{
			format = renderOptions.getOutputFormat( );
			if ( format == null || format.length( ) == 0 )
			{
				format = RenderOption.OUTPUT_FORMAT_HTML;
				renderOptions.setOutputFormat( format );
			}
		}
		
		Map appContext = executionContext.getAppContext( );
		if ( IRenderOption.OUTPUT_FORMAT_PDF.equals( format ) )
		{
			Object renderContext = appContext
					.get( EngineConstants.APPCONTEXT_PDF_RENDER_CONTEXT );
			if ( renderContext instanceof PDFRenderContext )
			{
				PDFRenderContext pdfContext = (PDFRenderContext) renderContext;
				mergeOption( renderOptions, PDFRenderOption.BASE_URL,
						pdfContext.getBaseURL( ) );
				mergeOption( renderOptions, PDFRenderOption.FONT_DIRECTORY,
						pdfContext.getFontDirectory( ) );
				mergeOption( renderOptions,
						PDFRenderOption.SUPPORTED_IMAGE_FORMATS, pdfContext
								.getSupportedImageFormats( ) );
				mergeOption( renderOptions, PDFRenderOption.IS_EMBEDDED_FONT,
						new Boolean( pdfContext.isEmbededFont( ) ) );
			}