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Re: AS_MESSAGE_FD


From: Eric Blake
Subject: Re: AS_MESSAGE_FD
Date: Sun, 23 Nov 2008 07:20:20 -0700
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According to Ralf Wildenhues on 11/23/2008 12:50 AM:
>> The semantics should be identical for third-party use;
> 
> assuming that no third-party code uses m4_ifdef([AS_MESSAGE_LOG_FD]).
> Right?

If they were using m4_ifdef([AS_MESSAGE_LOG_FD]), they were broken unless
they also checked its contents (in which case m4_ifset is the most compact
way to check that it is both defined and non-empty) - this patch does not
change the fact that it is valid to be defined but empty, in which case
logging is disabled.

> 
> FWIW, I haven't found using this, but it is a semantic change this way.

I still don't think there is an issue by having m4sh provide a default
empty definition.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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