Alas, I have upgraded the gallery script, and discovered issues.
When I was originally planning the update I, of course, planned a backup of the database. And I have several complete backups of the scripts.
The problem is there were a few creeping issues with Piwigo. A (relatively) minor error, something to do with the db, a display issue or two. And when I received the e-mail saying that in honor of the project’s 15th year they were pushing a new release I, naively, expected the error(s) would have been fixed.
The update interface has a nifty database backup tool, so my first attempt to backup was with this, the developer-provided tool. Nope, it exploded with a fatal error. Not a problem, PhpMyAdmin to the rescue. BAM! a backup on my desktop. (But I did report the issue.)
This should have been fair warning that something in the database abstraction was still not right.
But the update went off without a hitch. And, in the process, my 30+ plugins, extensions and themes were all disabled. Four of them also needed upgrading, which also went fine. But now there is a different database error being thrown up on each page load. Sigh.
At some point I will fix all this, but not just now.