Bug#1032662: elpa-debian-el: deb-view fails on zstd compressed debs

[Sven Joachim <svenjoac@gmx.de>]

Package: elpa-debian-el
Version: 37.10
Severity: normal

Visiting zstd compressed .deb files in deb-view mode-fails with a tar
error, here is a backtrace after toggling debug-on-error.

,----
| Debugger entered--Lisp error: (error "Malformed Tar header")
|   signal(error ("Malformed Tar header"))
|   tar-mode()
|   debview-mode()
|   deb-view-process("/tmp/libtinfo6_6.3+20220423-2_amd64.deb")
|   deb-view-mode()
|   set-auto-mode-0(deb-view-mode nil)
`----

Here /tmp/libtinfo6_6.3+20220423-2_amd64.deb is the package from Ubuntu
22.10, see https://packages.ubuntu.com/kinetic/amd64/libtinfo6/download.

While the control.tar.zst apparently can be inspected, there is no way
to get to the files in data.tar.zst.  I had to kill the buffer
libtinfo6_6.3+20220423-2_amd64.deb-DATA, confirming that I wanted to get
rid of that buffer despite it being modified.


-- System Information:
Debian Release: 12.0
  APT prefers unstable
  APT policy: (500, 'unstable'), (101, 'experimental')
merged-usr: no
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.10.172-nouveau (SMP w/2 CPU threads)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages elpa-debian-el depends on:
ii  bzip2           1.0.8-5+b1
ii  dh-elpa-helper  2.0.16
ii  dpkg            1.21.21
ii  emacsen-common  3.0.5
ii  reportbug       11.6.0
ii  xz-utils        5.4.1-0.2

Versions of packages elpa-debian-el recommends:
ii  emacs              1:28.2+1-12
ii  emacs-gtk [emacs]  1:28.2+1-12
ii  wget               1.21.3-1+b2

elpa-debian-el suggests no packages.

-- no debconf information