[Exim] exim AUTH driver - \000 in string bug?

This AUTH configuration fails with the \000 delimiters but parses ok if
I remove them:

login:
driver = plaintext
public_name = LOGIN
server_prompts = "Username:: : Password::"
server_condition = "${if
eq{$2}{${lookup{${1}\000hostname\000userPassword}dbmnz{/etc/sasldb2}{$va
lue}}}{1}{0}}"
server_set_id = $1

This appears to be a bug in the way that exim parses the config and
handles strings containing \000?

I already agree that using \000 is awful - and have mailed the SASL
folks accordingly.

But, as embedded nulls are part of the standard interaction for
PLAINTEXT auth, methinks there is room for an exim fixum too?

Regards
Jeff