Bug#685264: debbugs: obey “Control” field in pseudoheader of messages to ‘[email protected]’

On Sat, 15 Oct 2016, Ben Finney wrote:
> On 18-Aug-2012, Don Armstrong wrote:
> > Control: only works for [email protected] and [email protected] currently. Other
> > things may be supported in the future, but most of those other
> > messages have side effects.
> 
> Could you expand on that? I don't know what would be the down-side of
> having debbugs recognise the pseudoheader in a message such as
> <URL:https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=761980#24>.

I think for -done it would work, but for -quiet, -maintonly, or
-submitter, it doesn't really make sense.

I'm also concerned about the ordering of the control operations for
-done messages, but I think applying the control operations first, and
then the -done operation could work. [This is actually exactly the
opposite of how submit@ and nnn@ works, which is why it isn't trivial to
implement.]