Debconf syntax error message that I don't understand

[Frank Küster <frank@debian.org>]

Hi, 

I am at a loss with shell script that uses debconf.  The script itself
is in /etc/libpaper/, but since it is often called from maintainer
scripts, it uses debconf.

The problem is that debconf says it didn't get the right number of
arguments, but I think it did.  This is the relevant line of code:

      db_subst texlive-base/texconfig_ignorant binary "$binary" 

and this is what debconf says:

+ db_subst texlive-base/texconfig_ignorant binary dvipdfmx
+ _db_cmd SUBST texlive-base/texconfig_ignorant binary dvipdfmx
+ IFS=  printf %s\n SUBST texlive-base/texconfig_ignorant,binary,dvipdfmx
+ IFS=
 read -r _db_internal_line
debconf (developer): <-- SUBST texlive-base/texconfig_ignorant,binary,dvipdfmx
debconf (developer): --> 20 Incorrect number of arguments
+ RET=20 Incorrect number of arguments
+ return 20

The check in ConfModule looks like this:

sub command_subst {
	my $this = shift;
	return $codes{syntaxerror}, "Incorrect number of arguments" if @_ < 2;

So why does it think it has less than two arguments when what it gets is 

texlive-base/texconfig_ignorant,binary,dvipdfmx

I even tried to feed it an additional "foo" at the end, but that doesn't
change anything.  Probably I'm missing something trivial...

Regards, Frank

P.S. Script at 
http://anonscm.debian.org/viewvc/debian-tex/texlive2009/trunk/texlive-base/debian/texlive-base.libpaper?view=log

-- 
Frank Küster
Sprecher B90/Grüne OV Miltenberg und Umgebung
VCD Miltenberg, ADFC Aschaffenburg-Miltenberg
Debian Developer (TeXLive)