This is a fork of the now-dormant gallery2 project. The gallery code was written against PHP 5, and there are some changes in PHP 7 that were causing problems for me (as well as a bunch of warnings). I fixed the two bugs I found and cleaned up some of the warnings.
Some more fixes for PHP 8.0 and 8.1.
This code is based on gallery2 version 2.3.2 (core version 1.3.0.2)
FYI - Brad Dutton has revived Gallery 3 that is compatible with PHP 7. I haven't tried it, but you can download it at galleryrevival.com.