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 taskIDString;
	}
	/**
	 * Clean up the execution context before finishing using it
	 */
	public void close( )
	{
		scriptContext.exit( );
		if ( dataSource != null )
		{
			try
			{
				dataSource.close( );
			}
			catch ( IOException e )
			{
				log.log( Level.SEVERE, "Failed to close the data source", e );
			}
			dataSource = null;
		}
		if ( dataEngine != null )
		{
			dataEngine.shutdown( );
			dataEngine = null;
		}
	}
	/**
	 * creates new variable scope.
	 */
	public void newScope( )