Bug 121111 Bad event handler class name does not cause an error
Open a report design, open any Data Set's Property editor. Type in an invalid Java class name for the "Event Handler Class" property, say "aaa". Preview a report that uses that Data Set. The report executes normally. No error is shown. Event handlers are an integral part of a report design, and if a script handler class is not found, or if the handler throws a runtime exception, Report Engine should either stop the report execution, or show the error message in the generated report. (Tested with the 2005-12-15 nightly build)
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/RenderTask.java
if ( pageNumber <= 0 || pageNumber > totalPage )
		{
			throw new EngineException( "Can't find page hints :{0}", new Long(
					pageNumber ) );
		}
		if ( renderOptions == null )
		{
			throw new EngineException(
					"Render options have to be specified to render a report." );
		}
		doRender( pageNumber );
	}
	protected IContentEmitter createContentEmitter( ReportExecutor executor )
			throws EngineException
	{
		
		EngineEmitterServices services = new EngineEmitterServices( this );
		EngineConfig config = engine.getConfig( );
		if ( config != null )
		{
			services.setEmitterConfig( config.getEmitterConfigs( ) );
		}
		services.setRenderOption( renderOptions );
		services.setExecutor( executor );
		services.setRenderContext( appContext );
		services.setReportRunnable( runnable );
		String format = executionContext.getOutputFormat( );
		if ( format == null )
		{
			format = "html";