isDirectChat is not properly set

[PhantomRay]

Checklist

• I could not find a solution in the documentation, the existing issues or discussions.
• I already asked for help in the chat

In which Project did the bug appear?

Other

If you selected "Other" as Project, please enter in which project the bug occurred.

No response

On which platform did the bug appear?

Android, iOS

SDK Version

~0.37

Describe the problem caused by this bug

By looking at the source code, isDirectChat relies on directChatMatrixID. Inside directChatMatrixID block, it only sets value when membership == Membership.invite. It should cater the scenario for Membership.join which is majority of the cases. In another words, when membership is join, this value is incorrect when the room is actually a direct chat room.

  String? get directChatMatrixID {
    // Calculating the directChatMatrixId can be expensive. We cache it and
    // validate the cache instead every time.
    final cache = _cachedDirectChatMatrixId;
    if (cache != null) {
      final roomIds = client.directChats[cache];
      if (roomIds is List && roomIds.contains(id)) {
        return cache;
      }
    }

    if (membership == Membership.invite) {
      final userID = client.userID;
      if (userID == null) return null;
      final invitation = getState(EventTypes.RoomMember, userID);
      if (invitation != null && invitation.content['is_direct'] == true) {
        return _cachedDirectChatMatrixId = invitation.senderId;
      }
    }

    final mxId = client.directChats.entries
        .firstWhereOrNull((MapEntry<String, dynamic> e) {
      final roomIds = e.value;
      return roomIds is List<dynamic> && roomIds.contains(id);
    })?.key;
    if (mxId?.isValidMatrixId == true) return _cachedDirectChatMatrixId = mxId;
    return _cachedDirectChatMatrixId = null;
  }

  /// Wheither this is a direct chat or not
  bool get isDirectChat => directChatMatrixID != null;

Steps To Reproduce

No response

Screenshots or Logs

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Security related

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[PhantomRay]

I need to dig more as to why this didn't work for a particular room. Close it for now.