Program: 32155
Project: 32155
Buggy source:
public static String getMembershipNotice(Context context,Event msg,RoomState roomState){
  EventContent eventContent=JsonUtils.toEventContent(msg.getContentAsJsonObject());
  EventContent prevEventContent=msg.getPrevContent();
  String userDisplayName=eventContent.displayname;
  String prevUserDisplayName=null;
  String prevMembership=null;
  if (null != prevEventContent) {
    prevMembership=prevEventContent.membership;
  }
  if ((null != prevEventContent)) {
    prevUserDisplayName=prevEventContent.displayname;
  }
  if (TextUtils.isEmpty(userDisplayName)) {
    userDisplayName=getUserDisplayName(msg.getSender(),roomState);
  }
  if (TextUtils.equals(prevMembership,eventContent.membership)) {
    String redactedInfo=EventDisplay.getRedactionMessage(context,msg,roomState);
    if (!TextUtils.isEmpty(redactedInfo)) {
      return context.getString(R.string.notice_profile_change_redacted,userDisplayName,redactedInfo);
    }
 else {
      String displayText="String_Node_Str";
      if (!TextUtils.equals(userDisplayName,prevUserDisplayName)) {
        if (TextUtils.isEmpty(prevUserDisplayName)) {
          displayText=context.getString(R.string.notice_display_name_set,msg.getSender(),userDisplayName);
        }
 else         if (TextUtils.isEmpty(userDisplayName)) {
          displayText=context.getString(R.string.notice_display_name_removed,msg.getSender());
        }
 else {
          displayText=context.getString(R.string.notice_display_name_changed_from,msg.getSender(),prevUserDisplayName,userDisplayName);
        }
      }
      String avatar=eventContent.avatar_url;
      String prevAvatar=null;
      if (null != prevEventContent) {
        prevAvatar=prevEventContent.avatar_url;
      }
      if (!TextUtils.equals(prevAvatar,avatar) && (prevAvatar != avatar)) {
        if (!TextUtils.isEmpty(displayText)) {
          displayText=displayText + "String_Node_Str" + context.getString(R.string.notice_avatar_changed_too);
        }
 else {
          displayText=context.getString(R.string.notice_avatar_url_changed,userDisplayName);
        }
      }
      return displayText;
    }
  }
 else   if (RoomMember.MEMBERSHIP_INVITE.equals(eventContent.membership)) {
    if (null != eventContent.third_party_invite) {
      return context.getString(R.string.notice_room_third_party_registered_invite,eventContent.third_party_invite.display_name,getUserDisplayName(msg.stateKey,roomState),userDisplayName);
    }
 else {
      return context.getString(R.string.notice_room_invite,userDisplayName,getUserDisplayName(msg.stateKey,roomState));
    }
  }
 else   if (RoomMember.MEMBERSHIP_JOIN.equals(eventContent.membership)) {
    return context.getString(R.string.notice_room_join,userDisplayName);
  }
 else   if (RoomMember.MEMBERSHIP_LEAVE.equals(eventContent.membership)) {
    if (TextUtils.equals(msg.getSender(),msg.stateKey)) {
      return context.getString(R.string.notice_room_leave,userDisplayName);
    }
 else     if (null != prevMembership) {
      if (prevMembership.equals(RoomMember.MEMBERSHIP_JOIN) || prevMembership.equals(RoomMember.MEMBERSHIP_INVITE)) {
        return context.getString(R.string.notice_room_kick,userDisplayName,getUserDisplayName(msg.stateKey,roomState));
      }
 else       if (prevMembership.equals(RoomMember.MEMBERSHIP_BAN)) {
        return context.getString(R.string.notice_room_unban,userDisplayName,getUserDisplayName(msg.stateKey,roomState));
      }
    }
  }
 else   if (RoomMember.MEMBERSHIP_BAN.equals(eventContent.membership)) {
    return context.getString(R.string.notice_room_ban,userDisplayName,getUserDisplayName(msg.stateKey,roomState));
  }
 else {
    Log.e(LOG_TAG,"String_Node_Str" + eventContent.membership);
  }
  return null;
}

Fixed version (ground truth):
public static String getMembershipNotice(Context context,Event event,RoomState roomState){
  EventContent eventContent=JsonUtils.toEventContent(event.getContentAsJsonObject());
  EventContent prevEventContent=event.getPrevContent();
  String senderDisplayName=senderDisplayNameForEvent(event,eventContent,roomState);
  String prevUserDisplayName=null;
  String prevMembership=null;
  if (null != prevEventContent) {
    prevMembership=prevEventContent.membership;
  }
  if ((null != prevEventContent)) {
    prevUserDisplayName=prevEventContent.displayname;
  }
  String targetDisplayName=event.stateKey;
  if ((null != targetDisplayName) && (null != roomState)) {
    targetDisplayName=roomState.getMemberName(targetDisplayName);
  }
  if (TextUtils.equals(prevMembership,eventContent.membership)) {
    String redactedInfo=EventDisplay.getRedactionMessage(context,event,roomState);
    if (!TextUtils.isEmpty(redactedInfo)) {
      return context.getString(R.string.notice_profile_change_redacted,senderDisplayName,redactedInfo);
    }
 else {
      String displayText="String_Node_Str";
      if (!TextUtils.equals(senderDisplayName,prevUserDisplayName)) {
        if (TextUtils.isEmpty(prevUserDisplayName)) {
          displayText=context.getString(R.string.notice_display_name_set,event.getSender(),senderDisplayName);
        }
 else         if (TextUtils.isEmpty(senderDisplayName)) {
          displayText=context.getString(R.string.notice_display_name_removed,event.getSender());
        }
 else {
          displayText=context.getString(R.string.notice_display_name_changed_from,event.getSender(),prevUserDisplayName,senderDisplayName);
        }
      }
      String avatar=eventContent.avatar_url;
      String prevAvatar=null;
      if (null != prevEventContent) {
        prevAvatar=prevEventContent.avatar_url;
      }
      if (!TextUtils.equals(prevAvatar,avatar) && (prevAvatar != avatar)) {
        if (!TextUtils.isEmpty(displayText)) {
          displayText=displayText + "String_Node_Str" + context.getString(R.string.notice_avatar_changed_too);
        }
 else {
          displayText=context.getString(R.string.notice_avatar_url_changed,senderDisplayName);
        }
      }
      return displayText;
    }
  }
 else   if (RoomMember.MEMBERSHIP_INVITE.equals(eventContent.membership)) {
    if (null != eventContent.third_party_invite) {
      return context.getString(R.string.notice_room_third_party_registered_invite,eventContent.third_party_invite.display_name,targetDisplayName,senderDisplayName);
    }
 else {
      return context.getString(R.string.notice_room_invite,senderDisplayName,targetDisplayName);
    }
  }
 else   if (RoomMember.MEMBERSHIP_JOIN.equals(eventContent.membership)) {
    return context.getString(R.string.notice_room_join,senderDisplayName);
  }
 else   if (RoomMember.MEMBERSHIP_LEAVE.equals(eventContent.membership)) {
    if (TextUtils.equals(event.getSender(),event.stateKey)) {
      return context.getString(R.string.notice_room_leave,senderDisplayName);
    }
 else     if (null != prevMembership) {
      if (prevMembership.equals(RoomMember.MEMBERSHIP_JOIN) || prevMembership.equals(RoomMember.MEMBERSHIP_INVITE)) {
        return context.getString(R.string.notice_room_kick,senderDisplayName,targetDisplayName);
      }
 else       if (prevMembership.equals(RoomMember.MEMBERSHIP_BAN)) {
        return context.getString(R.string.notice_room_unban,senderDisplayName,targetDisplayName);
      }
    }
  }
 else   if (RoomMember.MEMBERSHIP_BAN.equals(eventContent.membership)) {
    return context.getString(R.string.notice_room_ban,senderDisplayName,targetDisplayName);
  }
 else {
    Log.e(LOG_TAG,"String_Node_Str" + eventContent.membership);
  }
  return null;
}