Website backup of database fails silently if no database is assigned to website
Summary
ISPConfig Panel, website backup tab. Starting "make backup of databases" shows no indication something is amiss. The backup never appeared in the list of backups. I discovered the (fully working Joomla website) did not have database assiged to it in ISPConfig, that is on the Databases display Site: showed "Select site".
Steps to reproduce
Tried testing, but can not create database without assigning it to a website. The problem website/database is old, I do not know how it got broken this way.
Correct behaviour
ISPConfig should show this error condition or at least indicate it can not make the database backup.
Environment
# cat /etc/debian_version
10.10
ISPConfig 3.2.5
# apachectl -v
Server version: Apache/2.4.38 (Debian)
Server built: 2021-06-10T10:13:06
# php -v
PHP 7.3.29-1+0~20210701.86+debian10~1.gbp7ad6eb (cli) (built: Jul 1 2021 16:10:10) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.3.29, Copyright (c) 1998-2018 Zend Technologies
with Zend OPcache v7.3.29-1+0~20210701.86+debian10~1.gbp7ad6eb, Copyright (c) 1999-2018, by Zend Technologies