Bug#265636: Idea for Dell CDROM detect issue

[Vincent.McIntyre@csiro.au]

> 1. Patch by Vincent McIntyre (Bug#265636) has good intent but buggy
>    as is. (I wish this type of syntax exists for "fail" function.)

That was only a sketch, as I don't have a good understanding of how such
an error should be presented to the user by d-i.
I think the problem with cdrom-detect.postinst is real and could be
cleaned up quite quickly.
I will study the code some more and try write a real patch.
If the author would like to help, or take over, I'm happy for that too.

Cheers
Vince