[Libvir] [PATCH] Avoid compile failure when HAVE_AVAHI is not defined.

[Jim Meyering]

"Richard W.M. Jones" <rjones at redhat.com> wrote:

> Jim Meyering wrote:
>> Without this patch, building without HAVE_AVAHI fails due to an unguarded
>> use of mdns_name.  Rather than adding yet another #ifdef..#endif (ugly
>> and less maintainable), I've chosen to un-ifdef the declarations and
>> a few uses.  The more code that we compile and use unconditionally,
>> the fewer surprises we'll encounter down the road.
>
> Strangely enough I didn't hit this problem when building on Cygwin,
> and I'm pretty sure they don't have avahi?

That file has changed recently.  I've just looked it up
and see that it's the "free (mdns_name);" that I added.

> My only reservation is what happens if mdns_* configuration is in
> libvirtd.conf, but there is no support in the binary.  Should we print
> out an error message or a warning?

IMHO, no, but it wouldn't hurt.

The current policy is to ignore config-file errors
for compiled-out features.

If we do change the policy, we should do it across the board.
However, it doesn't seem worth the trouble right now.
Why spend effort on broken or poorly-configured systems?