Bug#740673: apt-cdrom ident started requesting to insert cd even if cd is already mounted

[John Ogness <john.ogness@linutronix.de>]

I have been studying both apt-cdrom and d-i to understand the
behavior.

Here are the problems that I see. I will be happy to implement/fix these
issues if we agree on the correct behavior.

1. According to the man page the purpose of APT::CDROM::NoMount is to
   "prevent apt-cdrom from mounting and unmounting the mount point". So
   in my opinion, if this option is enabled, apt-cdrom should *never*
   mount or unmount. (That was not true for "ident" until now.)

2. When "add" mounts a CD, it sometimes unmounts it and sometimes not,
   depending on which exit path is taken. This seems quite bizarre and
   should be made consistent. In my opinion it should be a simple rule:
   "add" always unmounts the CD when it is done.

3. The man page for "ident" is not clear about what is supposed to
   happen. The previous behavior was to mount it (regardless of
   APT::CDROM::NoMount) and then maybe unmount it. In my opinion it
   should behave like "add" should. If APT::CDROM::NoMount is enabled,
   there is no mounting/unmounting. If it is not enabled, it would
   unmount any mounted CD and ask the user to insert a new CD before
   mounting it and proceeding. By redirecting stdin to /dev/null the
   user-feedback step would be skipped (just like "add").

Implementing these changes is straight forward. However, they would also
require a change to d-i to redirect stdin to /dev/null for "ident" to
avoid user-feedback (just as d-i already does for "add").

May I submit patches for apt and d-i to implement these changes?

John Ogness