Query: manually created GroupJoin with order by key descending generates invalid SQL

[maumar]

query:

from c in ctx.Customers
join o in ctx.Orders on c.CustomerID equals o.CustomerID into grouping
where c.CustomerID.StartsWith("A")
orderby c.CustomerID descending
select grouping.Count();

sql:

SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region], [o].[OrderID], [o].[CustomerID], [o].[EmployeeID], [o].[OrderDate]
FROM [Customers] AS [c]
LEFT JOIN [Orders] AS [o] ON [c].[CustomerID] = [o].[CustomerID]
WHERE [c].[CustomerID] LIKE N'A' + N'%' AND (LEFT([c].[CustomerID], LEN(N'A')) = N'A')
ORDER BY [c].[CustomerID] DESC, [c].[CustomerID]

exception:

A column has been specified more than once in the order by list. Columns in the order by list must be unique.

For client GJs we add ordering by key so that we can materialize elements correctly, it doesn't matter if we do asc or desc, so we should re-use customer generated order if one was specified.

[maumar]

fixed in b825435