This Debian bug report: http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=15d95340389f0f46bd214803ec19685c0a738a0e which was against a release candidate, was never communicated to us. A user on IRC (tsuucat, 22 October 2019, around 10:46) pointed it out, so I've raised this bug report. Note there is a patch against that Debian report, so I assume the reporter has tested it, I have no way of testing it here.
Fixed in commit b4521b891de48d7f62be739d02749c4aeca2fde8