Firefox mishandles .lz; /etc/mime.types lacks lz line

[Paul Eggert]

In <https://bugzilla.mozilla.org/show_bug.cgi?id=1379417> I reported a Firefox bug that appears to be due at least in part to /etc/mime.types missing a line for .lz files. To reproduce the problem:

1. Run Mozilla Firefox 54.0 on Ubuntu 16.04.2 LTS x86-64.

2. Visit https://www.iana.org/time-zones

3. Click on "tzdb-2017b.tar.lz" link for "Complete Distribution (Data, Code and Extras)"

A popup appears, saying "You have chosen to open tzdb-2017b.tar.lz which is: Lzip archive from: https://www.iana.org. Would you like to save this file?" What I expected is that the popup should give me the opportunity to run an archiving program, just as is done for https://www.iana.org/time-zones/repository/releases/tzdata2017b.tar.gz (referenced on the same page).

Apparently part of the problem is that /etc/mime.types contains entries for .gz but not for .lz. Could you please fix that? If I add the following line:

application/x-lzip lz

to ~/.mime-types, I do get a popup that suggests file-roller, which is an improvement (though still not as good as .gz). So I suggest adding such a line to /etc/mime.types.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: mime-support 3.59ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-83.106-generic 4.4.70
Uname: Linux 4.4.0-83-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.6
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Jul 9 11:56:57 2017
InstallationDate: Installed on 2016-04-23 (441 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
PackageArchitecture: all
SourcePackage: mime-support
UpgradeStatus: No upgrade log present (probably fresh install)