Fix double escaping of Chinese characters in JSON columns during updates

Co-authored-by: AndriySvyryd <6539701+AndriySvyryd@users.noreply.github.com>

Author: Copilot

src/EFCore.SqlServer/Storage/Internal/SqlServerOwnedJsonTypeMapping.cs

@@ -105,7 +105,10 @@ protected virtual string EscapeSqlLiteral(string literal)
     ///     doing so can result in application failures when updating to a new Entity Framework Core release.
     /// </summary>
     protected override string GenerateNonNullSqlLiteral(object value)
-        => $"'{EscapeSqlLiteral(JsonSerializer.Serialize(value))}'";
+    {
+        var jsonString = value is string str ? str : JsonSerializer.Serialize(value);
+        return $"'{EscapeSqlLiteral(jsonString)}'";
+    }
 
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to

test/EFCore.Relational.Specification.Tests/Update/JsonUpdateTestBase.cs

@@ -3633,6 +3633,40 @@ public virtual Task Add_and_update_nested_optional_primitive_collection(bool? va
                 }
             });
 
+    [ConditionalFact]
+    public virtual Task Edit_single_property_with_chinese_characters()
+        => TestHelpers.ExecuteWithStrategyInTransactionAsync(
+            CreateContext,
+            UseTransaction,
+            async context =>
+            {
+                var query = await context.JsonEntitiesBasic.ToListAsync();
+                var entity = query.Single(x => x.Id == 1);
+                entity.OwnedReferenceRoot.OwnedReferenceBranch.OwnedReferenceLeaf.SomethingSomething = "测试1";
+
+                ClearLog();
+                await context.SaveChangesAsync();
+            },
+            async context =>
+            {
+                var result = await context.Set<JsonEntityBasic>().SingleAsync(x => x.Id == 1);
+                Assert.Equal("测试1", result.OwnedReferenceRoot.OwnedReferenceBranch.OwnedReferenceLeaf.SomethingSomething);
+            },
+            async context =>
+            {
+                var query = await context.JsonEntitiesBasic.ToListAsync();
+                var entity = query.Single(x => x.Id == 1);
+                entity.OwnedReferenceRoot.OwnedReferenceBranch.OwnedReferenceLeaf.SomethingSomething = "测试2";
+
+                ClearLog();
+                await context.SaveChangesAsync();
+            },
+            async context =>
+            {
+                var result = await context.Set<JsonEntityBasic>().SingleAsync(x => x.Id == 1);
+                Assert.Equal("测试2", result.OwnedReferenceRoot.OwnedReferenceBranch.OwnedReferenceLeaf.SomethingSomething);
+            });
+
     public void UseTransaction(DatabaseFacade facade, IDbContextTransaction transaction)
         => facade.UseTransaction(transaction.GetDbTransaction());
 

test/EFCore.SqlServer.FunctionalTests/Update/JsonUpdateSqlServerTest.cs

@@ -2535,6 +2535,46 @@ public override Task Edit_single_property_collection_of_collection_of_nullable_i
     public override Task Edit_single_property_collection_of_collection_of_single()
         => Assert.ThrowsAsync<ArgumentOutOfRangeException>(base.Edit_single_property_collection_of_collection_of_single);
 
+    public override async Task Edit_single_property_with_chinese_characters()
+    {
+        await base.Edit_single_property_with_chinese_characters();
+
+        AssertSql(
+            """
+@p0='{"Name":"Root","Number":7,"OwnedCollectionBranch":[],"OwnedReferenceBranch":{"Date":"2101-01-01T00:00:00","Enum":2,"Enums":[-1,-1,2],"Fraction":10.1,"Id":10,"NullableEnum":-1,"NullableEnums":[null,-1,2],"OwnedCollectionLeaf":[{"SomethingSomething":"e1_r_r_c1"},{"SomethingSomething":"e1_r_r_c2"}],"OwnedReferenceLeaf":{"SomethingSomething":"测试1"}}}' (Nullable = false) (Size = 386)
+@p1='1'
+
+SET IMPLICIT_TRANSACTIONS OFF;
+SET NOCOUNT ON;
+UPDATE [JsonEntitiesBasic] SET [OwnedReferenceRoot] = @p0
+OUTPUT 1
+WHERE [Id] = @p1;
+""",
+            //
+            """
+SELECT TOP(2) [j].[Id], [j].[EntityBasicId], [j].[Name], [j].[OwnedCollectionRoot], [j].[OwnedReferenceRoot]
+FROM [JsonEntitiesBasic] AS [j]
+WHERE [j].[Id] = 1
+""",
+            //
+            """
+@p0='{"Name":"Root","Number":7,"OwnedCollectionBranch":[],"OwnedReferenceBranch":{"Date":"2101-01-01T00:00:00","Enum":2,"Enums":[-1,-1,2],"Fraction":10.1,"Id":10,"NullableEnum":-1,"NullableEnums":[null,-1,2],"OwnedCollectionLeaf":[{"SomethingSomething":"e1_r_r_c1"},{"SomethingSomething":"e1_r_r_c2"}],"OwnedReferenceLeaf":{"SomethingSomething":"测试2"}}}' (Nullable = false) (Size = 386)
+@p1='1'
+
+SET IMPLICIT_TRANSACTIONS OFF;
+SET NOCOUNT ON;
+UPDATE [JsonEntitiesBasic] SET [OwnedReferenceRoot] = @p0
+OUTPUT 1
+WHERE [Id] = @p1;
+""",
+            //
+            """
+SELECT TOP(2) [j].[Id], [j].[EntityBasicId], [j].[Name], [j].[OwnedCollectionRoot], [j].[OwnedReferenceRoot]
+FROM [JsonEntitiesBasic] AS [j]
+WHERE [j].[Id] = 1
+""");
+    }
+
     protected override void ClearLog()
         => Fixture.TestSqlLoggerFactory.Clear();