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
/**
	 * get the executor used to execute the report
	 * 
	 * @return report executor
	 */
	public IReportExecutor getExecutor( )
	{
		return executor;
	}
	public TOCBuilder getTOCBuilder( )
	{
		return tocBuilder;
	}
	public void setTOCBuilder( TOCBuilder builder )
	{
		this.tocBuilder = builder;
	}
	/**
	 * set the report document used in the context
	 * 
	 * @param doc
	 */
	public void setReportDocument( IReportDocument doc )
	{
		this.reportDoc = doc;
	}
	/**
	 * get the report document used in the context.
	 * 
	 * @return