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
* Since the data set in master page will be executed in each page
	 * and while the data set in report body will only be executed once,
	 * we need to remember the current report item is in master page or not.
	 * This will be used to help store the executed resultSetID and load it
	 * to distinguish them.
	 */
	public void setExecutingMasterPage( boolean isExecutingMasterPage )
	{
		this.isExecutingMasterPage = isExecutingMasterPage;
	}
	
	public boolean isExecutingMasterPage( )
	{
		return isExecutingMasterPage;
	}
	
	/**
	 * Add a page break listener.
	 * 
	 * @param listener
	 *            the page break listener.
	 */
	public void addPageBreakListener( IPageBreakListener listener )
	{
		if ( pageBreakListeners == null )
		{
			pageBreakListeners = new ArrayList( );
		}
		pageBreakListeners.add( listener );
	}