From 38c79bff4a64218da73c4d2e0e8b3a7eda0773b8 Mon Sep 17 00:00:00 2001
From: Shay Rojansky <roji@roji.org>
Date: Thu, 18 Jul 2019 18:38:15 +0200
Subject: [PATCH] Ignore convert nodes from nullable to non-nullable

Fixes #16653
---
 .../RelationalSqlTranslatingExpressionVisitor.cs      |  2 +-
 .../Query/SimpleQueryTestBase.cs                      |  9 +++++++++
 .../Query/SimpleQuerySqlServerTest.cs                 | 11 +++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/EFCore.Relational/Query/Pipeline/RelationalSqlTranslatingExpressionVisitor.cs b/src/EFCore.Relational/Query/Pipeline/RelationalSqlTranslatingExpressionVisitor.cs
index 40a78652d37..33a5c706f6f 100644
--- a/src/EFCore.Relational/Query/Pipeline/RelationalSqlTranslatingExpressionVisitor.cs
+++ b/src/EFCore.Relational/Query/Pipeline/RelationalSqlTranslatingExpressionVisitor.cs
@@ -540,7 +540,7 @@ protected override Expression VisitUnary(UnaryExpression unaryExpression)
                     // Object convert needs to be converted to explicit cast when mismatching types
                     if (operand.Type.IsInterface
                             && unaryExpression.Type.GetInterfaces().Any(e => e == operand.Type)
-                        || unaryExpression.Type.UnwrapNullableType() == operand.Type
+                        || unaryExpression.Type.UnwrapNullableType() == operand.Type.UnwrapNullableType()
                         || unaryExpression.Type.UnwrapNullableType() == typeof(Enum))
                     {
                         return sqlOperand;
diff --git a/test/EFCore.Specification.Tests/Query/SimpleQueryTestBase.cs b/test/EFCore.Specification.Tests/Query/SimpleQueryTestBase.cs
index e008446554b..58f2333596a 100644
--- a/test/EFCore.Specification.Tests/Query/SimpleQueryTestBase.cs
+++ b/test/EFCore.Specification.Tests/Query/SimpleQueryTestBase.cs
@@ -5989,5 +5989,14 @@ public virtual Task Inner_parameter_in_nested_lambdas_gets_preserved(bool isAsyn
                 cs => cs.Where(c => c.Orders.Where(o => c == new Customer { CustomerID = o.CustomerID }).Count() > 0),
                 entryCount: 89);
         }
+
+        [ConditionalTheory]
+        [MemberData(nameof(IsAsyncData))]
+        public virtual Task Convert_to_nullable_on_nullable_value_is_ignored(bool isAsync)
+        {
+            return AssertQuery<Order>(
+                isAsync,
+                os => os.Select(o => new Order { OrderDate = o.OrderDate.Value }));
+        }
     }
 }
diff --git a/test/EFCore.SqlServer.FunctionalTests/Query/SimpleQuerySqlServerTest.cs b/test/EFCore.SqlServer.FunctionalTests/Query/SimpleQuerySqlServerTest.cs
index 371628c2358..75d3be4ef73 100644
--- a/test/EFCore.SqlServer.FunctionalTests/Query/SimpleQuerySqlServerTest.cs
+++ b/test/EFCore.SqlServer.FunctionalTests/Query/SimpleQuerySqlServerTest.cs
@@ -4877,6 +4877,17 @@ FROM [Orders] AS [o]
     WHERE (([c].[CustomerID] = [o].[CustomerID]) AND [o].[CustomerID] IS NOT NULL) AND (([c].[CustomerID] = [o].[CustomerID]) AND [o].[CustomerID] IS NOT NULL)) > 0");
         }
 
+        [ConditionalTheory]
+        [MemberData(nameof(IsAsyncData))]
+        public override async Task Convert_to_nullable_on_nullable_value_is_ignored(bool isAsync)
+        {
+            await base.Convert_to_nullable_on_nullable_value_is_ignored(isAsync);
+
+            AssertSql(
+                @"SELECT [o].[OrderDate]
+FROM [Orders] AS [o]");
+        }
+
         private void AssertSql(params string[] expected)
             => Fixture.TestSqlLoggerFactory.AssertBaseline(expected);