How to make confmodules abort? (was Re: Bug#214935: cdebconf-newt-udeb: OK button misleading...)

[barbier@linuxfr.org (Denis Barbier)]

[I discussed privately with Joey Hess while the BTS was down, and am now
switching back to debian-boot.  I wrote some code to add an Abort
button, its purpose being to return to main-menu, e.g. when a progress
bar is displayed and user does not want to wait anymore]

On Sat, Nov 22, 2003 at 04:45:11PM -0500, Joey Hess wrote:
[...]
> > > This gets me wondering why we need to distinguish between back and abort
> > > at the debconf protocol level, but I suppose the problem is that the
> > > only way for a progress bar to abort is to kill the confmodule program?
> > 
> > Yes.
> 
> BTW, how do you know what the confmodule program is when main-menu has
> execed something else? I don't see how cdebconf could tell in this case
> that a config script is the thing to kill, and not main-menu.

I see only 2 options:
  a.  Either kill main-menu and restart everything
  b.  Or only kill the config script.

Of course (b) must be implemented.  Config scripts can register their
PID, e.g. by adding
   db_set debconf/confmodule_pid $$
in src/client/confmodule, which will automatically set
debconf/confmodule_pid to the right PID when config scripts are shell
scripts.  Similarly the debconfclient_new function in src/debconfclient.c
can also set debconf/confmodule_pid to the current PID.
IMO having a single value is enough, there is no need to keep PID on
a stack.  Comments?

Denis