Can't call method "description" on an undefined value at /usr/share/perl5/Debconf/Question.pm line 93

[Quirin Lohr]

Ubuntu 14.04 and 16.04
debconf version 1.5.51ubuntu2 and 1.5.58ubuntu1

I have a central LDAP based debconf configdb with default answers set up. If there is an answer for a not installed package, debconf-get-selections stops with error.

Expected behavior: ignore configdb entry if no templatedb entry present.

Bug can be worked around with a simple if statement. in /usr/share/perl5/Debconf/Question.pm line 93.
Return value if no templatedb defined missing, what should be returned?

Original:

sub description {
        my $this=shift;
        return $this->_expand_vars($this->template->description);
}

Workaraound:

sub description {
        my $this=shift;
        if ( defined $this->template ) {
                return $this->_expand_vars($this->template->description);
        }
}