Bug#943387: upgrade-from-grub-legacy: environment variable DPKG_MAINTSCRIPT_NAME is required

[Colin Watson]

On Thu, Oct 24, 2019 at 11:05:45AM +0200, Martin von Wittich wrote:
> apparently, one of our servers still has some GRUB legacy files
> installed, which causes `dpkg-reconfigure grub-pc` to tell me that I
> have to run `upgrade-from-grub-legacy`. That doesn't work though:
[...]
> As far as I can tell, the issue occurs because upgrade-from-grub-legacy calls
> the postinst directly without providing the DPKG_MAINTSCRIPT_NAME environment
> variable (which dpkg would do when it calls a maintainer script), and the
> command dpkg-maintscript-helper inside this postinst script then fails because
> it requires this variable.
> 
> I've attached a patch that resolves the issue for me.

Thanks!  Your patch looks sensible, and I've applied it for the next
upload.

-- 
Colin Watson                                       [cjwatson at debian.org]