message: Tweak edge case behaviour
diff: @@ -121,14 +121,20 @@ const JoinRuleSettings = ({ room, promptUpgrade, onError, beforeChange }: IProps
  const onRestrictedRoomIdsChange = (newAllowRoomIds: string[]) => {
  if (!arrayHasDiff(restrictedAllowRoomIds || [], newAllowRoomIds)) return;
  - const newContent: IJoinRuleEventContent = {
  + if (!newAllowRoomIds.length) {
  + setContent({
  + join_rule: JoinRule.Invite,
  + });
  + return;
  + }
  +
  + setContent({
  join_rule: JoinRule.Restricted,
  allow: newAllowRoomIds.map(roomId => ({
  "type": RestrictedAllowType.RoomMembership,
  "room_id": roomId,
  })),
  - };
  - setContent(newContent);
  + });
  };
  const onEditRestrictedClick = async () => {
  @@ -209,6 +215,11 @@ const JoinRuleSettings = ({ room, promptUpgrade, onError, beforeChange }: IProps
  });
  return;
  }
  +
  + // when setting to 0 allowed rooms/spaces set to invite only instead as per the note
  + if (!restrictedAllowRoomIds.length) {
  + joinRule = JoinRule.Invite;
  + }
  }
  if (beforeJoinRule === joinRule && !restrictedAllowRoomIds) return;
  