Add missing _migrationsAssemblyObject assignment in RelationalOptionsExtension copy constructor (#36136)

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: AndriySvyryd <[email protected]>

Author: Copilot

src/EFCore.Relational/Infrastructure/RelationalOptionsExtension.cs

@@ -61,6 +61,7 @@ protected RelationalOptionsExtension(RelationalOptionsExtension copyFrom)
         _useRelationalNulls = copyFrom._useRelationalNulls;
         _querySplittingBehavior = copyFrom._querySplittingBehavior;
         _migrationsAssembly = copyFrom._migrationsAssembly;
+        _migrationsAssemblyObject = copyFrom._migrationsAssemblyObject;
         _migrationsHistoryTableName = copyFrom._migrationsHistoryTableName;
         _migrationsHistoryTableSchema = copyFrom._migrationsHistoryTableSchema;
         _executionStrategyFactory = copyFrom._executionStrategyFactory;

test/EFCore.Relational.Tests/Infrastructure/RelationalOptionsExtensionTest.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Reflection;
 using Microsoft.EntityFrameworkCore.TestUtilities.FakeProvider;
 
 // ReSharper disable InconsistentNaming
@@ -94,4 +95,25 @@ public void Throws_if_MinBatchSize_out_of_range()
             RelationalStrings.InvalidMinBatchSize(-1),
             Assert.Throws<InvalidOperationException>(
                 () => new FakeRelationalOptionsExtension().WithMinBatchSize(-1)).Message);
+
+    [ConditionalFact]
+    public void MigrationsAssemblyObject_is_preserved_after_cloning()
+    {
+        var optionsExtension = new FakeRelationalOptionsExtension();
+        
+        // Get the current executing assembly
+        var assembly = Assembly.GetExecutingAssembly();
+        
+        // Set the migrations assembly
+        optionsExtension = (FakeRelationalOptionsExtension)optionsExtension.WithMigrationsAssembly(assembly);
+        
+        // Verify the migrations assembly object is set
+        Assert.Same(assembly, optionsExtension.MigrationsAssemblyObject);
+        
+        // Clone the options by using another With method (which internally calls Clone())
+        optionsExtension = (FakeRelationalOptionsExtension)optionsExtension.WithCommandTimeout(100);
+        
+        // Verify the migrations assembly object is still preserved after cloning
+        Assert.Same(assembly, optionsExtension.MigrationsAssemblyObject);
+    }
 }