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
/**
	 * calculate the aggragate among the expression list
	 * 
	 * @param exprArray
	 * @throws DataException
	 */
	public void calculate( Object[] exprArray, int[] groupArray, int arrayType )
			throws DataException
	{
		assert exprArray != null;
		assert groupArray != null;
		assert exprArray.length == groupArray.length;
		IBaseExpression baseExpression = null;
		int groupLevel, level = helper.getCurrentGroupLevel( ), exprType = helper.getCurrentExpressionType( );
		Context context = Context.enter( );
		try
		{
			for ( int i = 0; i < exprArray.length; i++ )
			{
				baseExpression = (IBaseExpression) exprArray[i];
				groupLevel = groupArray[i];
				helper.setExpressionType( arrayType, groupLevel );
				if ( baseExpression instanceof IConditionalExpression )
				{
					IConditionalExpression condition = (IConditionalExpression) baseExpression;
					IScriptExpression op = condition.getExpression( );
					IScriptExpression op1 = condition.getOperand1( );
					IScriptExpression op2 = condition.getOperand2( );
					if ( op != null )
						op.setHandle( helper.compileExpression( op.getText( ),