Bug 121687 Exception throws when export data in table which inside a grid cell.
Description: Exception throws when export data in table which inside a grid cell. Steps to reproduce: 1. insert a grid. 2. insert one table to one grid cell. 3. insert another table to the other grid cell. 4. export data in two tables. Expected result: Data are exported. Actual result: Exception in: ReportEngineService.getMetaData( )
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/ir/Report.java
{
		this.reportDesign = reportDesign;
		if ( basePath == null || basePath.equals( "" ) ) 
		{
			File file = new File( reportDesign.getFileName( ) );
			basePath = file.getParent( );
		}
	}
	/**
	 * get queries used in this report.
	 * 
	 * @see org.eclipse.birt.report.engine.analysis.IReportQuery
	 * @return the list of the query
	 */
	public ArrayList getQueries( )
	{
		return this.queries;
	}
	public HashMap getQueryIDs( )
	{
		return this.queryIDs;
	}
	/**
	 * Puts all the report parameters including those appear inside parameter
	 * groups to the <code>allParameters</code> object.
	 * 
	 * @param params
	 *            A collection of parameters and parameter groups.
	 */
	protected void flattenParameter( ArrayList params )