Control: retitle -1 GRUB not installed or installed to the wrong device
I found that grub-installer may generate a wrong bootdev value for
grub-pc when state=2 and previous_state!=1. This may happen at least
in the following three cases if the user selects the device in the
proposed list:
- if the first device listed by grub-mkdevicemap is the installation
media (/cdrom or /hd-media) or has no known partition table nor
filesystem, GRUB may be installed to the disk containing /boot instead
of the device selected by the user;
- if unsupported OS are detected by os-prober, bootdev may be empty
and GRUB is not installed;
- if the user answers "no" to "Install the GRUB boot loader to your
primary drive?", bootdev may be empty and GRUB is not installed.
It does not happen if the user chose "Enter the device manually".
The common root cause is grub-installer/bootdev being used without
being manually set by the user even after bootdev was set by
select_bootdev.
Attached is a minimal patch which uses grub-installer/bootdev only
when if was manually set by the user, and not when the bootdev was set
by select_bootdev. I tested it with the last case. Test and feedback
appreciated.