Query: Fix flaky GroupJoinFlatteningExpressionVisitor

Issue: A nested visitor was stored in static field but if contained states which caused flattening to fail some times. Also verified that such issue is not appearing anywhere else in query.
dotnet · Aug 15, 2019 · b315b56 · b315b56
1 parent a9e4766
commit b315b56
Showing 1 changed file with 11 additions and 15 deletions.
diff --git a/src/EFCore/Query/Internal/GroupJoinFlatteningExpressionVisitor.cs b/src/EFCore/Query/Internal/GroupJoinFlatteningExpressionVisitor.cs
@@ -5,17 +5,16 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Linq.Expressions;
-using System.Reflection;
 using Microsoft.EntityFrameworkCore.Internal;
 
 namespace Microsoft.EntityFrameworkCore.Query.Internal
 {
     public class GroupJoinFlatteningExpressionVisitor : ExpressionVisitor
     {
-        private static readonly SelectManyVerifyingExpressionVisitor _selectManyVerifyingExpressionVisitor
-            = new SelectManyVerifyingExpressionVisitor();
         private static readonly EnumerableToQueryableMethodConvertingExpressionVisitor _enumerableToQueryableReMappingExpressionVisitor
             = new EnumerableToQueryableMethodConvertingExpressionVisitor();
+        private readonly SelectManyVerifyingExpressionVisitor _selectManyVerifyingExpressionVisitor
+            = new SelectManyVerifyingExpressionVisitor();
 
         protected override Expression VisitMethodCall(MethodCallExpression methodCallExpression)
         {
@@ -34,12 +33,12 @@ protected override Expression VisitMethodCall(MethodCallExpression methodCallExp
                         // GroupJoin
                         var outer = Visit(groupJoinMethod.Arguments[0]);
                         var inner = Visit(groupJoinMethod.Arguments[1]);
-                        var outerKeySelector = UnwrapLambdaFromQuoteExpression(groupJoinMethod.Arguments[2]);
-                        var innerKeySelector = UnwrapLambdaFromQuoteExpression(groupJoinMethod.Arguments[3]);
-                        var groupJoinResultSelector = UnwrapLambdaFromQuoteExpression(groupJoinMethod.Arguments[4]);
+                        var outerKeySelector = groupJoinMethod.Arguments[2].UnwrapLambdaFromQuote();
+                        var innerKeySelector = groupJoinMethod.Arguments[3].UnwrapLambdaFromQuote();
+                        var groupJoinResultSelector = groupJoinMethod.Arguments[4].UnwrapLambdaFromQuote();
 
-                        var selectManyCollectionSelector = UnwrapLambdaFromQuoteExpression(methodCallExpression.Arguments[1]);
-                        var selectManyResultSelector = UnwrapLambdaFromQuoteExpression(methodCallExpression.Arguments[2]);
+                        var selectManyCollectionSelector = methodCallExpression.Arguments[1].UnwrapLambdaFromQuote();
+                        var selectManyResultSelector = methodCallExpression.Arguments[2].UnwrapLambdaFromQuote();
 
                         var collectionSelectorBody = selectManyCollectionSelector.Body;
                         var defaultIfEmpty = false;
@@ -161,11 +160,11 @@ protected override Expression VisitMethodCall(MethodCallExpression methodCallExp
                         // GroupJoin
                         var outer = Visit(groupJoinMethod.Arguments[0]);
                         var inner = Visit(groupJoinMethod.Arguments[1]);
-                        var outerKeySelector = UnwrapLambdaFromQuoteExpression(groupJoinMethod.Arguments[2]);
-                        var innerKeySelector = UnwrapLambdaFromQuoteExpression(groupJoinMethod.Arguments[3]);
-                        var groupJoinResultSelector = UnwrapLambdaFromQuoteExpression(groupJoinMethod.Arguments[4]);
+                        var outerKeySelector = groupJoinMethod.Arguments[2].UnwrapLambdaFromQuote();
+                        var innerKeySelector = groupJoinMethod.Arguments[3].UnwrapLambdaFromQuote();
+                        var groupJoinResultSelector = groupJoinMethod.Arguments[4].UnwrapLambdaFromQuote();
 
-                        var selectManyResultSelector = UnwrapLambdaFromQuoteExpression(methodCallExpression.Arguments[1]);
+                        var selectManyResultSelector = methodCallExpression.Arguments[1].UnwrapLambdaFromQuote();
 
                         var groupJoinResultSelectorBody = groupJoinResultSelector.Body;
                         var defaultIfEmpty = false;
@@ -383,8 +382,5 @@ protected override Expression VisitParameter(ParameterExpression parameterExpres
                 return base.VisitParameter(parameterExpression);
             }
         }
-
-        private LambdaExpression UnwrapLambdaFromQuoteExpression(Expression expression)
-            => (LambdaExpression)((UnaryExpression)expression).Operand;
     }
 }