> > Fourth, is this distro-specific?  My system has neither update-mime nor /usr/lib/mime,
> > suggesting that this utility is not universal.
> 
> Yes, this is Debian-specific.

Slackware has update-mime-database, which is why I asked for other apps besides Chromium to test the problem. If this is distro-specific perhaps we at least could share how to replicate and also resolve the problem, and which distros are/might be involved.

Darrell