Bug 165278 this.getDisplayContent()="" in script of text will destroy preview[0801]
Description: this.getDisplayContent()="" in script of text will destroy preview Build number:2.1.2.v20061120 and 2.2.0.v20061117 Steps to reproduce: 1. Insert a text item, select it and switch to script editor 2. Input this.getDisplayContent()="" and preview Expected result: Error message about the incorrect script. Actual result: In 2.1.2, I saw HTTP Status 500 - type Exception report message description The server encountered an internal error () that prevented it from fulfilling this request. In 2.2.0, I saw error dialog with java.lang.ClassCastException.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/executor/ExecutionContext.java
/**
	 * @return Returns the dataEngine.
	 */
	public IDataEngine getDataEngine( )
	{
		if ( dataEngine == null )
		{
			dataEngine = DataEngineFactory.getInstance( ).createDataEngine(
					this );
		}
		return dataEngine;
	}
	public void closeDataEngine( )
	{
		if ( dataEngine != null )
		{
			dataEngine.shutdown( );
			dataEngine = null;
		}
	}
	/**
	 * @param name
	 * @param value
	 */
	public void setParameterValue( String name, Object value )
	{
		Object parameter = params.get( name );
		if ( parameter instanceof ParameterAttribute )
		{
			( (ParameterAttribute) parameter ).setValue( value );