Bug#608263: /etc/grub.d/05_debian_theme: new 05_debian_theme doesn't allow no background image

[Colin Watson]

On Tue, Jan 04, 2011 at 01:04:49AM +0100, Mario 'BitKoenig' Holbe wrote:
> On Sun, Jan 02, 2011 at 05:17:05PM +0100, Alexander Kurtz wrote:
> > Am Mittwoch, den 29.12.2010, 12:57 +0100 schrieb Miros??aw Zalewski:
> > > There is brand new 05_debian_theme in newest grub-pc. Unfortunetly, it
> > > does not allow user to have no background splash image at all, unless
> > Yep, that's true. I'm currently thinking how the user could specify that
> > he doesn't want a background image at all. Would it be ok, if you had to
> > put a line like this into /etc/default/grub:
> > 	GRUB_BACKGROUND=""
> 
> IMHO, 05_debian_theme should simply do nothing if GRUB_BACKGROUND is
> set (empty or not), because this one is for and handled by 00_header
> already (not as sophisticated as 05_debian_theme does it, but ...
> well...).

I'm inclined to agree (pending arguments to the contrary) that
05_debian_theme should do nothing if GRUB_BACKGROUND is set to a
non-empty value.  I quite like GRUB_BACKGROUND="" as a way to disable
it, though.

> Btw: testing for an empty but set environment variable is not that
> easy... :) 'if env | grep -q ^GRUB_BACKGROUND=; then ...' comes to my
> mind...

  $ unset GRUB_BACKGROUND
  $ [ "${GRUB_BACKGROUND+unset}" ]; echo $?
  1
  $ GRUB_BACKGROUND=
  $ [ "${GRUB_BACKGROUND+unset}" ]; echo $?
  0
  $ GRUB_BACKGROUND=foo
  $ [ "${GRUB_BACKGROUND+unset}" ]; echo $?
  0

> IMHO, the same applies for the case where 05_debian_theme chooses the
> lexically first image in /boot/grub - just don't do it: if the user
> copied one there, he had to configure it somewhere anyways.
> 
> Furthermore, the default colors set by 05_debian_theme for the three
> alternatives to grub_background.sh: GRUB_BACKGROUND, the lexically first
> image in /boot/grub, and for desktop-grub.png if no grub_background.sh
> exists are simply ... well, useless: black/black - hmmm :)

Yes - it would be better to leave them at their built-in defaults,
surely?

-- 
Colin Watson                                       [cjwatson at debian.org]