Wrong SQL generation with group by and Count() in EF Core 2.1 Preview 1

[HSchwichtenberg]

In EF Core 2.1 Preview 1, this query

var groups = (from p in ctx.FlightSet
                   group p by p.Departure into g
                   select new { City = g.Key, Count = g.Count() }).Where(x => x.Count > 5).OrderBy(x => x.Count).ToList();

produces this SQL

SELECT [p].[Departure], COUNT(*)
FROM [Flight] AS [p]
WHERE COUNT(*) > 5
GROUP BY [p].[Departure]

which is wrong.

Exception:

System.Data.SqlClient.SqlException: 'An aggregate may not appear in the WHERE clause unless it is in a subquery contained in a HAVING clause or a select list, and the column being aggregated is an outer reference.'

Further technical details

EF Core version: 2.1.0-preview1-final
Database Provider: Microsoft.EntityFrameworkCore.SqlServer
Operating system: Windows 10 1703
SQL Server: 2017
IDE: Visual Studio 2017 15.6.1

[smitpatel]

Generated SQL in nightly build

      SELECT [p].[Departure] AS [City], COUNT(*) AS [Count]
      FROM [FlightSet] AS [p]
      GROUP BY [p].[Departure]
      HAVING COUNT(*) > 5
      ORDER BY [Count]

Duplicate of #10870