Enforcing at most one unbookmarked head on default branch

[Jens Peter Secher]

I am trying to figure out how to enforce a policy of at most one 
unbookmarked head on the default branch.  On the central repository I have

     [hooks]
     pretxnchangegroup = .hg/validate $HG_NODE

where the validate script is

     #!/bin/sh
     HEADSWOBOOKMARK=`hg log --template '{node|short} ' -r 'head() & 
branch(default) & !bookmark()'`
     if [ `echo "$HEADSWOBOOKMARK" | wc -w` -gt 1 ]
     then
         echo "Only one unbookmarked head allowed on default branch."
         for n in $HEADSWOBOOKMARK
         do
             echo " $n has no bookmark"
         done
         exit 1
     fi
     exit 0

But it does not work when doing e.g.

     $ hg push -B feature1 -f

because apparently the new bookmark feature1 is not visible when 
pretxnchangegroup is run.

Is there a way to achieve what I want?

Cheers,
/JP
-- 
Jens Peter Secher, GPG fingerprint 0EE5978AFE63E8A1.

A. Because it breaks the logical sequence of discussion.
Q. Why is top posting bad?