[Room] Return m.bad.encrypted

lib/src/event.dart

@@ -248,6 +248,8 @@ class Event {
         return MessageTypes.Sticker;
       case "m.location":
         return MessageTypes.Location;
+      case "m.bad.encrypted":
+        return MessageTypes.BadEncrypted;
       default:
         if (type == EventTypes.Message) {
           return MessageTypes.Text;
@@ -378,7 +380,8 @@ class Event {
   /// Searches for the reply event in the given timeline.
   Future<Event> getReplyEvent(Timeline timeline) async {
     if (!isReply) return null;
-    final String replyEventId = content['m.relates_to']['m.in_reply_to']['event_id'];
+    final String replyEventId =
+        content['m.relates_to']['m.in_reply_to']['event_id'];
     return await timeline.getEventById(replyEventId);
   }
 }
@@ -394,6 +397,7 @@ enum MessageTypes {
   Location,
   Reply,
   Sticker,
+  BadEncrypted,
   None,
 }
 

lib/src/room.dart

@@ -1487,6 +1487,8 @@ class Room {
 
   /// Decrypts the given [event] with one of the available ingoingGroupSessions.
   Event decryptGroupMessage(Event event) {
+    Map<String, dynamic> decryptedPayload;
+    try {
       if (!client.encryptionEnabled) throw ("Encryption is not enabled");
       if (event.content["algorithm"] != "m.megolm.v1.aes-sha2") {
         throw ("Unknown encryption algorithm");
@@ -1509,8 +1511,16 @@ class Room {
           decryptResult.message_index;
       // TODO: The client should check that the sender's fingerprint key matches the keys.ed25519 property of the event which established the Megolm session when marking the event as verified.
 
-    final Map<String, dynamic> decryptedPayload =
-        json.decode(decryptResult.plaintext);
+      decryptedPayload = json.decode(decryptResult.plaintext);
+    } catch (exception) {
+      decryptedPayload = {
+        "content": {
+          "msgtype": "m.bad.encrypted",
+          "body": exception.toString(),
+        },
+        "type": "m.room.message",
+      };
+    }
     return Event(
       content: decryptedPayload["content"],
       typeKey: decryptedPayload["type"],