Bug 139346 Using isTopN in table inside list group header doesn't work.
Description: Using isTopN in table inside list group header doesn't work. Steps to reproduce: 1.Insert a list with a group 2.Insert a table to list group header 3.Using Total.isTopN(row[],2,null,0) as filter expression in table item. 4.Preview Result: Only the first group displayed top 2 records, other groups kept display all records.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/QueryExecutor.java
public Scriptable getSharedScope( )
	{
		return this.sharedScope;
	}
	
	/**
	 * Gets the Javascript scope for evaluating expressions for this query
	 * 
	 * @return
	 */
	public Scriptable getQueryScope( )
	{
		if ( queryScope == null )
		{
			 
			
			
			
			queryScope = newSubScope( parentScope );
			queryScope.setPrototype( dataSet.getJSDataSetObject() );
		}
		return queryScope;
	}
	
	/**
	 * Creates a subscope within parent scope
	 * @param parentAndProtoScope parent scope. If null, the shared top-level scope is used as parent
	 */
	private Scriptable newSubScope( Scriptable parentAndProtoScope )
	{