Bug 132515 Expression like "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" is return an error
Description: Add an expression like "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" is return an error.The nesting "Toltal" seem not to be work. Step to reproduce: 1.new a datasource and dataset 2.drag the dataset to layout veiw for a table 3.set a group on the table 4.Insert a data into the group header with the expression e.g. "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" Actual result: An error was thrown out Expected result: It should work correctly in order to support some requirments
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/expression/ExpressionProcessor.java
helper.setExpressionType( exprType, 0 );
					helper.resetPassLevel( );
				}
			}
		}
		finally
		{
			Context.exit();
		}
	}
	/*
	 *  (non-Javadoc)
	 * @see org.eclipse.birt.data.engine.executor.IExpressionProcessor#compileFilter(java.util.List, org.eclipse.birt.data.engine.executor.IComputedColumnsState)
	 */
	public void compileFilter( List filters,
			IComputedColumnsState computedColumns )
	{
		IBaseExpression baseExpression = null;
		String expression = "";
		IScriptExpression operator = null;
		FilterExpressionParser parser = new FilterExpressionParser( metaData,
				computedColumns );
		parser.setDataSetMode( this.isDataSetMode );
		parser.setResultSetPopulator( this.rsPopulator );
		for ( int i = 0; i < filters.size( ); i++ )
		{
			try
			{
				baseExpression = ( (FilterDefinition) filters.get( i ) ).getExpression( );
				if ( baseExpression instanceof IConditionalExpression )