From 970e8a4e8a3f78429ed813fa6f70136921b30a9d Mon Sep 17 00:00:00 2001
From: Andriy Svyryd <AndriySvyryd@users.noreply.github.com>
Date: Wed, 17 Nov 2021 11:10:10 -0800
Subject: [PATCH] Update the foreign key builder after IsRequired()

Fixes #26611
---
 .../Metadata/Internal/InternalForeignKeyBuilder.cs | 14 +++++++++++++-
 .../ModelBuilding/ManyToOneTestBase.cs             | 13 ++++++++-----
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/src/EFCore/Metadata/Internal/InternalForeignKeyBuilder.cs b/src/EFCore/Metadata/Internal/InternalForeignKeyBuilder.cs
index 901ad9085ed..b27dd1c66ec 100644
--- a/src/EFCore/Metadata/Internal/InternalForeignKeyBuilder.cs
+++ b/src/EFCore/Metadata/Internal/InternalForeignKeyBuilder.cs
@@ -973,7 +973,19 @@ private static bool IsCompatible(
                 Metadata.DeclaringEntityType.Model.ScopedModelDependencies?.Logger.AmbiguousEndRequiredWarning(Metadata);
             }
 
-            Metadata.SetIsRequired(required, configurationSource);
+            if (AppContext.TryGetSwitch("Microsoft.EntityFrameworkCore.Issue26611", out var enabled) && enabled)
+            {
+                Metadata.SetIsRequired(required, configurationSource);
+                return this;
+            }
+
+            IConventionForeignKey? foreignKey = Metadata;
+            var result = Metadata.DeclaringEntityType.Model.ConventionDispatcher.Track(
+                () => Metadata.SetIsRequired(required, configurationSource), ref foreignKey);
+            if (foreignKey != null)
+            {
+                return ((ForeignKey)foreignKey).Builder;
+            }
 
             return this;
         }
diff --git a/test/EFCore.Tests/ModelBuilding/ManyToOneTestBase.cs b/test/EFCore.Tests/ModelBuilding/ManyToOneTestBase.cs
index 2aff4f4504f..d9bbc51af58 100644
--- a/test/EFCore.Tests/ModelBuilding/ManyToOneTestBase.cs
+++ b/test/EFCore.Tests/ModelBuilding/ManyToOneTestBase.cs
@@ -1942,14 +1942,17 @@ public virtual void Creates_shadow_FK_property_with_non_shadow_PK()
                     {
                         b.HasMany<Beta>()
                             .WithOne(e => e.FirstNav)
-                            .HasForeignKey("ShadowId");
+                            .HasForeignKey("ShadowId")
+                            .IsRequired()
+                            .HasAnnotation("Test", "foo");
                     });
 
-                modelBuilder.FinalizeModel();
+                var model = modelBuilder.FinalizeModel();
 
-                Assert.Equal(
-                    "ShadowId",
-                    modelBuilder.Model.FindEntityType(typeof(Beta)).FindNavigation("FirstNav").ForeignKey.Properties.Single().Name);
+                var fk = model.FindEntityType(typeof(Beta)).FindNavigation("FirstNav").ForeignKey;
+                Assert.Equal("ShadowId", fk.Properties.Single().Name);
+                Assert.True(fk.IsRequired);
+                Assert.Equal("foo", fk["Test"]);
             }
 
             [ConditionalFact]