Detatching principal keeps track of unreferenced dependents (#25702)

dotnet · Aug 27, 2021 · fdf3998 · fdf3998
1 parent 22644dc
commit fdf3998
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Showing 2 changed files with 74 additions and 3 deletions.
diff --git a/src/EFCore/ChangeTracking/Internal/StateManager.cs b/src/EFCore/ChangeTracking/Internal/StateManager.cs
@@ -587,10 +587,23 @@ public virtual void StopTracking(InternalEntityEntry entry, EntityState oldState
                 _internalEntityEntrySubscriber.Unsubscribe(entry);
             }
 
-            var entityType = entry.EntityType;
-
-            foreach (var key in entityType.GetKeys())
+            foreach (var key in entry.EntityType.GetKeys())
             {
+                foreach (var foreignKey in key.GetReferencingForeignKeys())
+                {
+                    var dependentToPrincipal = foreignKey.DependentToPrincipal;
+                    if (dependentToPrincipal != null)
+                    {
+                        foreach (InternalEntityEntry dependentEntry in GetDependents(entry, foreignKey))
+                        {
+                            if (dependentEntry[dependentToPrincipal] == entry.Entity)
+                            {
+                                RecordReferencedUntrackedEntity(entry.Entity, dependentToPrincipal, dependentEntry);
+                            }
+                        }
+                    }
+                }
+
                 FindIdentityMap(key)?.Remove(entry);
             }
 

diff --git a/test/EFCore.Tests/ChangeTracking/Internal/FixupTest.cs b/test/EFCore.Tests/ChangeTracking/Internal/FixupTest.cs
@@ -3281,5 +3281,63 @@ protected internal override void OnModelCreating(ModelBuilder modelBuilder)
                     });
             }
         }
+
+        private class Dependent
+        {
+            public int Id { get; set; }
+            public string Url { get; set; }
+            public Principal Principal { get; set; }
+        }
+
+        private class Principal
+        {
+            public int Id { get; set; }
+            public string Title { get; set; }
+        }
+
+        private class DetachingContext : DbContext
+        {
+            public DbSet<Principal> Principals { get; set; }
+            public DbSet<Dependent> Dependents { get; set; }
+
+            protected internal override void OnConfiguring(DbContextOptionsBuilder options)
+                => options
+                    .UseInternalServiceProvider(InMemoryFixture.DefaultServiceProvider)
+                    .UseInMemoryDatabase(nameof(DetachingContext));
+        }
+
+        [ConditionalFact] // Issue #21949
+        public void Detatching_principal_tracks_unreferenced_foreign_keys()
+        {
+            using var context = new DetachingContext();
+
+            var dependent = new Dependent { Url = "http://myblog.net" };
+            var principal = new Principal { Title = "Hello World" };
+            dependent.Principal = principal;
+            context.AddRange(dependent, principal);
+
+            Assert.Equal(EntityState.Added, context.Entry(principal).State);
+            Assert.Equal(EntityState.Added, context.Entry(dependent).State);
+
+            var principalId = principal.Id;
+            Assert.Equal(principalId, context.Entry(dependent).Property<int?>("PrincipalId").CurrentValue);
+            Assert.Same(principal, dependent.Principal);
+
+            context.Entry(principal).State = EntityState.Detached;
+
+            Assert.Equal(EntityState.Detached, context.Entry(principal).State);
+            Assert.Equal(EntityState.Added, context.Entry(dependent).State);
+
+            principal.Id = 0; // So it re-adds
+
+            context.Add(principal);
+            Assert.NotEqual(principalId, principal.Id);
+
+            Assert.Equal(principal.Id, context.Entry(dependent).Property<int?>("PrincipalId").CurrentValue);
+            Assert.Same(principal, dependent.Principal);
+
+            Assert.Equal(EntityState.Added, context.Entry(principal).State);
+            Assert.Equal(EntityState.Added, context.Entry(dependent).State);
+        }
     }
 }