Quoting Dean Brooks:
>> As $acl_* is empty by default (unless strict_acl_vars is set, as of
>> 4.64), you should use ${if !def:acl_m0}.
> Wow. When was strict_acl_vars added to the spec?
In 4.64, together with the new named acl variables ($acl_c_something,
$acl_m_anything).
> I see absolutely no mention of it in the ChangeLog for either 4.63 or
> 4.65. Was it added in 4.64 and then accidentally left out of the 4.65
> documentation?
It _is_ in the spec, and was removed from NewStuff when the spec was
updated. Hm, probably not such a good idea, I guess there are not many
people (including myself) doing a "diff old-spec new-spec". I think
that's what the Changelog should be for...
See
http://www.exim.org/mailman/mmsearch/exim-cvs?config=exim-cvs&restrict=&exclude=&method=and&format=short&sort=time&words=strict_acl_vars