RE: Behavior change from warning to error in m4 between 1.4.5 and 1.4.13 ?

[Jesse Mundis]

Thank for the quick response.  That's exactly what I needed to know.

Cheers,

Jesse

-----Original Message-----
From: Eric Blake [mailto:address@hidden 
Sent: Wednesday, August 14, 2013 5:27 AM
To: Jesse Mundis
Cc: address@hidden
Subject: Re: Behavior change from warning to error in m4 between 1.4.5 and 
1.4.13 ?

On 08/13/2013 09:26 PM, Jesse Mundis wrote:
> Hi there.

Hello.

[Can you convince your mailer to wrap long lines?]

Thanks for the report.

> 
> I'd like to know if this change was intentional

Yes.  Per the NEWS file for 1.4.9:

** The `include' builtin now affects exit status on failure, as required by
   POSIX.  Use `sinclude' if you need a successful exit status.

> It *appears* like the -E option has become an undocumented default 
> behavior,

No, rather, a bug in m4 was fixed to obey a POSIX requirement.

> Is there a way to revert this behavior?

Sendmail is incorrectly relying on the bug, and the fix is not to m4, but to 
sendmail, to use sinclude rather than include when attempting to include a file 
that might not exist.

> Any insight into how/why this change happened, and a way to work around it to 
> get the old behavior would be greatly appreciated.

Find the place in the sendmail code where it includes ostype/*file.m4, and fix 
that to use sinclude.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org