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
* (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.engine.executor.IFactoryContext#getConfigs()
	 */
	public Map getConfigs( )
	{
		return configs;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.engine.executor.IFactoryContext#getReportDesign()
	 */
	public ReportDesignHandle getDesign( )
	{
		return (ReportDesignHandle) runnable.getDesignHandle( );
	}
	/**
	 * @return Returns the report.
	 */
	public IReportContent getReportContent( )
	{
		return reportContent;
	}
	public void setReportContent( IReportContent content )
	{
		this.reportContent = content;
		content.getErrors( ).addAll( onPrepareErrors );
	}
	/**