prefix is not set correctly in grub2

[Bin Li]

This bug report based on lp:1097570 .

An $prefix was introduced to fix grub2-signed can not find the right device when there are two filesystems containing the file '.disk/info'.

But after dig, I had an recovery partition(hd0,1) which had '.disk/info', and when start the daily-live image or 13.10 image from DVD we found the prefix is '(hd0,1)/boot/grub' , so it means the prefix was set by 'search' command or the $prefix is zero or do not exist.

grub> cat (memdisk)/grub.cfg

if [ -z "$prefix" -o ! -e "$prefix" ]; then
        if ! search --file --set=root /.disk/info; then
                search --file --set=root /.disk/mini-info
        fi
        set prefix=($root)/boot/grub
fi
if [ -e $prefix/$platform/grub.cfg ]; then
        source $prefix/$platform/grub.cfg
else
        source $prefix/grub.cfg
fi

And it's a little hard for me to debug it, if any idea which I can help to locate the reason, feel free let me know.

Thanks a lot!

[Ara Pulido (ara)]

We will keep tracking this bug with https://bugs.launchpad.net/oem-priority/+bug/1097570