Add handle ownership again

common/lib/src/realm_types.dart

@@ -68,6 +68,12 @@ class RealmError extends Error {
   String toString() => "Realm error : $message";
 }
 
+/// An error throw when operating on an object that has been closed.
+/// {@category Realm}
+class RealmClosedError extends RealmError {
+  RealmClosedError(String message) : super(message);
+}
+
 /// Thrown if the operation is not supported.
 /// {@category Realm}
 class RealmUnsupportedSetError extends UnsupportedError implements RealmError {
@@ -78,6 +84,7 @@ class RealmUnsupportedSetError extends UnsupportedError implements RealmError {
 class RealmStateError extends StateError implements RealmError {
   RealmStateError(super.message);
 }
+
 /// @nodoc
 class Decimal128 {} // TODO Support decimal128 datatype https://github.com/realm/realm-dart/issues/725
 

lib/src/list.dart

@@ -55,12 +55,11 @@ class ManagedRealmList<T extends Object?> extends collection.ListBase<T> with Re
   }
 
   @override
-  int get length => realmCore.getListSize(_handle);
-
-  @override
+  int get length => realmCore.getListSize(handle);
 
   /// Setting the `length` is a required method on [List], but makes no sense
   /// for [RealmList]s. Hence this operation is a no-op that simply ignores [newLength]
+  @override
   set length(int newLength) {} // no-op for managed lists
 
   @override
@@ -168,7 +167,14 @@ extension RealmListInternal<T extends Object?> on RealmList<T> {
 
   ManagedRealmList<T> asManaged() => this is ManagedRealmList<T> ? this as ManagedRealmList<T> : throw RealmStateError('$this is not managed');
 
-  RealmListHandle get handle => asManaged()._handle;
+  RealmListHandle get handle {
+    final result = asManaged()._handle;
+    if (result.released) {
+      throw RealmClosedError('Cannot access a list that belongs to a closed Realm');
+    }
+
+    return result;
+  }
 
   static RealmList<T> create<T extends Object?>(RealmListHandle handle, Realm realm, RealmObjectMetadata? metadata) => RealmList<T>._(handle, realm, metadata);