Bug 146967 Total fuction with result of the aggregate on group-Level should be enhanced
Description: Now if we want to do total fuction with the Aggregate result on the group level, it cant be fulfilled. For example, we set a total.sum() aggregate on a group level first, and then we sum the result of total.sum() again. The expected result should simply equal to sum over all rows. But the actual result is not as our requirement. I attached the design file as the example. Expected result: The aggregation on the group total should be enhanced, or we cant get expected result such as the requirement that total.rank() with the average result on the group level and so on.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/expression/MultiPassExpressionCompiler.java
return this.hasNesetedAggregate;
	}
	/**
	 * set total pass level. the total pass level must be the max of passLevel
	 * 
	 * @param passLevel
	 */
	private void setTotalPassLevel( int passLevel )
	{
		if ( this.totalPassLevel < passLevel )
			this.totalPassLevel = passLevel;
		else
			this.totalPassLevel = 0;
	}
	/**
	 * if the computed column has been calculated, it will be added into
	 * available list.
	 * 
	 * @param name
	 */
	void addAvailableCmpColumn( String name )
	{
		if ( this.availableCmpList == null )
			availableCmpList = new ArrayList( );
		availableCmpList.add( name );
	}
	/**
	 * get aggregate status, if has aggregate, return true. or return false
	 * 
	 * @return