Query: Preserve Schema in SqlFunctionExpression while visiting children

src/EFCore.Specification.Tests/Query/DbFunctionsTestBase.cs

@@ -45,7 +45,7 @@ public virtual void String_Like_Literal_With_Escape()
             using (var context = CreateContext())
             {
                 var count = context.Customers.Count(c => EF.Functions.Like(c.ContactName, "!%", "!"));
-                
+
                 Assert.Equal(0, count);
             }
         }

test/EFCore.SqlServer.FunctionalTests/Query/UdfDbFunctionSqlServerTests.cs

@@ -192,6 +192,12 @@ public string DollarValueInstance(int starCount, string value)
                 throw new NotImplementedException();
             }
 
+            [DbFunction(Schema = "dbo")]
+            public static string IdentityString(string s)
+            {
+                throw new NotImplementedException();
+            }
+
             #endregion
 
             public UDFSqlContext(DbContextOptions options)
@@ -855,6 +861,25 @@ FROM [Customers] AS [c]
             }
         }
 
+        [Fact]
+        public void Nullable_navigation_property_access_preserves_schema_for_sql_function()
+        {
+            using (var context = CreateContext())
+            {
+                var result = context.Orders
+                    .OrderBy(o => o.Id)
+                    .Select(o => UDFSqlContext.IdentityString(o.Customer.FirstName))
+                    .FirstOrDefault();
+
+                Assert.Equal("Customer", result);
+                AssertSql(
+                    @"SELECT TOP(1) [dbo].IdentityString([o.Customer].[FirstName])
+FROM [Orders] AS [o]
+LEFT JOIN [Customers] AS [o.Customer] ON [o].[CustomerId] = [o.Customer].[Id]
+ORDER BY [o].[Id]");
+            }
+        }
+
         #endregion
 
         #region Instance
@@ -1571,6 +1596,13 @@ returns bit
                                                         return 0
                                                     end");
 
+                context.Database.ExecuteSqlCommand(@"create function [dbo].[IdentityString] (@customerName nvarchar(max))
+                                                    returns nvarchar(max)
+                                                    as
+                                                    begin
+                                                        return @customerName;
+                                                    end");
+
                 var order11 = new Order { Name = "Order11", ItemCount = 4, OrderDate = new DateTime(2000, 1, 20) };
                 var order12 = new Order { Name = "Order12", ItemCount = 8, OrderDate = new DateTime(2000, 2, 21) };
                 var order13 = new Order { Name = "Order13", ItemCount = 15, OrderDate = new DateTime(2000, 3, 20) };