bug#69004: Cannot open lzip-compressed info manuals

[Eli Zaretskii]

> From: Francesco Turco <fturco@posteo.net>
> Date: Fri, 09 Feb 2024 16:49:59 +0000
> 
> I'm using GNU Emacs 29.2 on a Gentoo Linux system.
> 
> On this system, all info manuals are compressed with lzip and have a .lz
> suffix.

Emacs doesn't (yet) support Info manuals compressed with lzip.

> When running M-x info and opening any info manual (e.g. the info manual
> for bash), I get error messages similar to the following one:
> 
> > Info file `bash' does not exist; consider installing it
> 
> In reality the info manual for bash is available on my system:
> 
> $ file /usr/share/info/bash.info.lz 
> /usr/share/info/bash.info.lz: lzip compressed data, version: 1
> 
> In info.el source code there is no instance of either "lzip" or "lz".
> In particular, there is no lzip-related entry in the Info-suffix-list
> variable definition.
> 
> In my opinion it would be nice to add support for lzip-compressed info
> manuals to M-x info.

Patches welcome to add lzip support to info.el.