Error when extracting archive of Debian package

[pombredanne]

Description

When extracting http://ftp.debian.org/debian/pool/main/l/labplot/labplot_2.7.0-1_armel.deb I get some errors:

$ ./extractcode labplot_2.7.0-1_armel.deb Extracting archives...
[####################] 16                                         
ERROR extracting: labplot_2.7.0-1_armel.deb-extract/data.tar.xz-extract/usr/share/doc/labplot/examples/log_scales.lml: Unrecognized archive format
ERROR extracting: labplot_2.7.0-1_armel.deb-extract/data.tar.xz-extract/usr/share/doc/labplot/examples/mathematical_functions.lml: Unrecognized archive format
ERROR extracting: labplot_2.7.0-1_armel.deb-extract/data.tar.xz-extract/usr/share/doc/labplot/examples/fit_(Anscombe_s_quartet).lml: Unrecognized archive format
Extracting done.

[pombredanne]

Based on a quick check:

$ file *
fit (Anscombe's quartet).lml: gzip compressed data, was "", last modified: Mon Oct 12 08:15:52 2015, from Unix
log_scales.lml:               gzip compressed data, was "", last modified: Tue Jan 20 07:10:57 2015, from Unix
mathematical_functions.lml:   gzip compressed data, was "", last modified: Sun Nov  6 12:51:53 2016, from Unix

So these should be extracted alright and gunzip does it fine.

[sbs2001]

Repaste from gitter
My archive manager is GNOME's File Roller

I just played with #1798. As far as I can tell, the issue is not specific to extractcode. My system by default treated .lml file as an archive and gives the same error when I attempt to unzip it.