Question about decryption prompts

[Sotir Danailov]

Hello, I have a question about how GRUB handles prompting for a
password for encrypted disks using LVM. I am using Debian Testing and
I have GRUB 2.12 installed, but this was present on GRUB 2.06 as well.

So I have 2 encrypted logical volumes. One is for /boot and the other is for /

I have keyfiles setup in the initramfs for these volumes so that the
same prompts don't get shown after GRUB has handled them.

When I boot, I get the first prompt for /boot, after which I get a
second prompt for /, but the interesting thing about the second one is
that if I just press enter without writing anything, it then shows me
the menu to choose what I want to boot into. This doesn't happen with
the first prompt for /boot. I haven't setup keyfiles for GRUB, but
according to the documentation, if I had, it shouldn't have shown a
prompt in the first place.

What I'm wondering is whether it reuses my input from the previous
prompt. If I try to decrypt the disk manually using cryptsetup all
prompts work properly and I always have to input the proper password
to be able to unlock the device.