Query: compilation error for queries with navigations inside set result operators and Count

[maumar]

query:

context.Gears.Select(g => g.Weapons.Concat(g.Weapons).Count())

throws:

System.ArgumentException : Expression of type 'System.Collections.Generic.IEnumerable`1[Microsoft.EntityFrameworkCore.Storage.ValueBuffer]' cannot be used for parameter of type 'System.Collections.Generic.IEnumerable`1[System.Object]' of method 'System.Collections.Generic.IEnumerable`1[System.Object] Concat[Object](System.Collections.Generic.IEnumerable`1[System.Object], System.Collections.Generic.IEnumerable`1[System.Object])'
	at System.Linq.Expressions.Expression.ValidateOneArgument(MethodBase method, ExpressionType nodeKind, Expression arg, ParameterInfo pi)
	at System.Linq.Expressions.Expression.Call(MethodInfo method, Expression arg0, Expression arg1)
	C:\git\EntityFramework\src\EFCore\Query\ResultOperatorHandler.cs(531,0): at Microsoft.EntityFrameworkCore.Query.ResultOperatorHandler.HandleSetOperation(EntityQueryModelVisitor entityQueryModelVisitor, Expression secondSource, MethodInfo setMethodInfo)
	C:\git\EntityFramework\src\EFCore\Query\ResultOperatorHandler.cs(144,0): at Microsoft.EntityFrameworkCore.Query.ResultOperatorHandler.HandleConcat(EntityQueryModelVisitor entityQueryModelVisitor, ConcatResultOperator concatResultOperator)
	C:\git\EntityFramework\src\EFCore\Query\ResultOperatorHandler.cs(36,0): at Microsoft.EntityFrameworkCore.Query.ResultOperatorHandler.<>c.<.cctor>b__33_4(EntityQueryModelVisitor v, ResultOperatorBase r, QueryModel __)
	C:\git\EntityFramework\src\EFCore\Query\ResultOperatorHandler.cs(89,0): at Microsoft.EntityFrameworkCore.Query.ResultOperatorHandler.HandleResultOperator(EntityQueryModelVisitor entityQueryModelVisitor, ResultOperatorBase resultOperator, QueryModel queryModel)
	C:\git\EntityFramework\src\EFCore.Relational\Query\Internal\RelationalResultOperatorHandler.cs(68,0): at Microsoft.EntityFrameworkCore.Query.Internal.RelationalResultOperatorHandler.HandlerContext.EvalOnClient(Boolean requiresClientResultOperator)
	C:\git\EntityFramework\src\EFCore.Relational\Query\Internal\RelationalResultOperatorHandler.cs(156,0): at Microsoft.EntityFrameworkCore.Query.Internal.RelationalResultOperatorHandler.HandleResultOperator(EntityQueryModelVisitor entityQueryModelVisitor, ResultOperatorBase resultOperator, QueryModel queryModel)
	C:\git\EntityFramework\src\EFCore\Query\EntityQueryModelVisitor.cs(1034,0): at Microsoft.EntityFrameworkCore.Query.EntityQueryModelVisitor.VisitResultOperator(ResultOperatorBase resultOperator, QueryModel queryModel, Int32 index)
	C:\git\EntityFramework\src\EFCore.Relational\Query\RelationalQueryModelVisitor.cs(1136,0): at Microsoft.EntityFrameworkCore.Query.RelationalQueryModelVisitor.VisitResultOperator(ResultOperatorBase resultOperator, QueryModel queryModel, Int32 index)
	at Remotion.Linq.QueryModelVisitorBase.VisitResultOperators(ObservableCollection`1 resultOperators, QueryModel queryModel)
	at Remotion.Linq.QueryModelVisitorBase.VisitQueryModel(QueryModel queryModel)
	C:\git\EntityFramework\src\EFCore\Query\EntityQueryModelVisitor.cs(589,0): at Microsoft.EntityFrameworkCore.Query.EntityQueryModelVisitor.VisitQueryModel(QueryModel queryModel)
	C:\git\EntityFramework\src\EFCore.Relational\Query\RelationalQueryModelVisitor.cs(269,0): at Microsoft.EntityFrameworkCore.Query.RelationalQueryModelVisitor.VisitQueryModel(QueryModel queryModel)
	C:\git\EntityFramework\src\EFCore.Relational\Query\RelationalQueryModelVisitor.cs(446,0): at Microsoft.EntityFrameworkCore.Query.RelationalQueryModelVisitor.VisitSubQueryModel(QueryModel queryModel)
	C:\git\EntityFramework\src\EFCore.Relational\Query\ExpressionVisitors\SqlTranslatingExpressionVisitor.cs(888,0): at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.SqlTranslatingExpressionVisitor.VisitSubQuery(SubQueryExpression expression)
	at Remotion.Linq.Clauses.Expressions.SubQueryExpression.Accept(ExpressionVisitor visitor)
	at Remotion.Linq.Parsing.ThrowingExpressionVisitor.Visit(Expression expression)
	C:\git\EntityFramework\src\EFCore.Relational\Query\ExpressionVisitors\SqlTranslatingExpressionVisitor.cs(110,0): at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.SqlTranslatingExpressionVisitor.Visit(Expression expression)
	C:\git\EntityFramework\src\EFCore.Relational\Query\ExpressionVisitors\RelationalProjectionExpressionVisitor.cs(195,0): at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.RelationalProjectionExpressionVisitor.Visit(Expression expression)
	C:\git\EntityFramework\src\EFCore\Query\EntityQueryModelVisitor.cs(923,0): at Microsoft.EntityFrameworkCore.Query.EntityQueryModelVisitor.VisitSelectClause(SelectClause selectClause, QueryModel queryModel)
	C:\git\EntityFramework\src\EFCore.Relational\Query\RelationalQueryModelVisitor.cs(1054,0): at Microsoft.EntityFrameworkCore.Query.RelationalQueryModelVisitor.VisitSelectClause(SelectClause selectClause, QueryModel queryModel)
	at Remotion.Linq.Clauses.SelectClause.Accept(IQueryModelVisitor visitor, QueryModel queryModel)
	at Remotion.Linq.QueryModelVisitorBase.VisitQueryModel(QueryModel queryModel)
	C:\git\EntityFramework\src\EFCore\Query\EntityQueryModelVisitor.cs(589,0): at Microsoft.EntityFrameworkCore.Query.EntityQueryModelVisitor.VisitQueryModel(QueryModel queryModel)
	C:\git\EntityFramework\src\EFCore.Relational\Query\RelationalQueryModelVisitor.cs(269,0): at Microsoft.EntityFrameworkCore.Query.RelationalQueryModelVisitor.VisitQueryModel(QueryModel queryModel)
	C:\git\EntityFramework\src\EFCore\Query\EntityQueryModelVisitor.cs(170,0): at Microsoft.EntityFrameworkCore.Query.EntityQueryModelVisitor.CreateQueryExecutor[TResult](QueryModel queryModel)
	C:\git\EntityFramework\src\EFCore\Storage\Database.cs(70,0): at Microsoft.EntityFrameworkCore.Storage.Database.CompileQuery[TResult](QueryModel queryModel)
	--- End of stack trace from previous location where exception was thrown ---
	at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
	C:\git\EntityFramework\src\EFCore\Query\Internal\QueryCompiler.cs(159,0): at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.CompileQueryCore[TResult](Expression query, INodeTypeProvider nodeTypeProvider, IDatabase database, IDiagnosticsLogger`1 logger, Type contextType)
	C:\git\EntityFramework\src\EFCore\Query\Internal\QueryCompiler.cs(102,0): at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass15_0`1.<Execute>b__0()
	C:\git\EntityFramework\src\EFCore\Query\Internal\CompiledQueryCache.cs(69,0): at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQueryCore[TFunc](Object cacheKey, Func`1 compiler)
	C:\git\EntityFramework\src\EFCore\Query\Internal\CompiledQueryCache.cs(44,0): at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
	C:\git\EntityFramework\src\EFCore\Query\Internal\QueryCompiler.cs(98,0): at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
	C:\git\EntityFramework\src\EFCore\Query\Internal\EntityQueryProvider.cs(62,0): at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)
	at Remotion.Linq.QueryableBase`1.GetEnumerator()

[maumar]

those query sources are not marked for materialization (because of Count), but it seems that Concat result operator require them to be materialized

[maumar]

fixed in e1d7b16