Bug#1099701: grub2: 'cmdpath' environment variable removed

[Pascal Hambourg]

Package: src:grub2
Version: 2.12~rc1-12
X-Debbugs-CC: mate.kukri at canonical.com

Commit "Port UEFI based network stack to 2.12 (LP: #2039081)" [1] added 
the patch add-fw_path-variable-to-detect-config-file-on-efi.patch [2] 
which removes the 'cmdpath' GRUB environment variable (and replaces it 
with the 'fw_path' variable on EFI platforms). However 'cmdpath' may be 
used in configuration scripts such as the early grub.cfg embedded in 
Debian monolithic EFI CD boot images [3] and is mentioned in upstream 
GRUB documentation [4].

[1] 
<https://salsa.debian.org/grub-team/grub/-/commit/1c99ac2f0965a398603fb53180f42191addc96b6>
[2] 
<https://salsa.debian.org/grub-team/grub/-/blob/master/debian/patches/network/add-fw_path-variable-to-detect-config-file-on-efi.patch?ref_type=heads>
[3] 
<https://salsa.debian.org/grub-team/grub/-/blob/master/debian/build-efi-images?ref_type=heads>
[4] <https://www.gnu.org/software/grub/manual/grub/grub.html>

What is the best course of action ?
- Restore 'cmdpath' as in upstream ?
- Restore 'cmdpath' with the same value as 'fw_path' if it exists, else 
as in upstream ?
- Other ?