Bug 135790 ClassCastException in RowData.
ClassCastException is thrown in RowData line 81(IBaseExpression expr = ( IBaseExpression ) valueExpressions.get( index - 1 );).
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/parser/EngineIRVisitor.java
MapRuleDesign rule = new MapRuleDesign( );
		rule.setExpression( handle.getOperator( ), handle.getValue1( ), handle
				.getValue2( ) );
		rule.setDisplayText( handle.getDisplayKey( ), handle.getDisplay( ) );
		String testExpr = handle.getTestExpression( );
		if ( testExpr != null && testExpr.length( ) > 0 )
		{
			rule.setTestExpression( testExpr );
		}
		else if ( ( defaultStr != null ) && defaultStr.length( ) > 0 )
		{
			rule.setTestExpression( defaultStr );
		}
		else
		{
			
			return null;
		}
		ConditionalExpression condExpr = new ConditionalExpression( rule
				.getTestExpression( ),
				toDteFilterOperator( rule.getOperator( ) ), rule.getValue1( ),
				rule.getValue2( ) );
		rule.setConditionExpr( condExpr );
		return rule;
	}
	/**
	 * Checks if a given style is in report's style list, if not, assign a
	 * unique name to it and then add it to the style list.
	 * 
	 * @param style