2 files changed, 15 insertions, 1 deletions
diff --git a/lib/events/stateevent.cpp b/lib/events/stateevent.cpp
index fd8079be..c4151676 100644
--- a/lib/events/stateevent.cpp
+++ b/lib/events/stateevent.cpp
@@ -20,8 +20,19 @@
 
 using namespace QMatrixClient;
 
+// Aside from the normal factory to instantiate StateEventBase inheritors
+// StateEventBase itself can be instantiated if there's a state_key JSON key
+// but the event type is unknown.
 [[gnu::unused]] static auto stateEventTypeInitialised =
-        RoomEvent::factory_t::chainFactory<StateEventBase>();
+    RoomEvent::factory_t::addMethod(
+        [] (const QJsonObject& json, const QString& matrixType)
+        {
+            if (auto e = StateEventBase::factory_t::make(json, matrixType))
+                return e;
+            return json.contains("state_key")
+                   ? makeEvent<StateEventBase>(unknownEventTypeId(), json)
+                   : nullptr;
+        });
 
 bool StateEventBase::repeatsState() const
 {
diff --git a/lib/events/stateevent.h b/lib/events/stateevent.h
index d488c0a0..dc017b11 100644
--- a/lib/events/stateevent.h
+++ b/lib/events/stateevent.h
@@ -38,6 +38,9 @@ namespace QMatrixClient {
     using StateEventPtr = event_ptr_tt<StateEventBase>;
     using StateEvents = EventsArray<StateEventBase>;
 
+    template <>
+    inline bool is<StateEventBase>(const Event& e) { return e.isStateEvent(); }
+
     /**
      * A combination of event type and state key uniquely identifies a piece
      * of state in Matrix.