Re: pkg/51424: pkgtools/libnbcompat string.h header does not properly guard strdup definition

[William Orr <will%worrbase.com@localhost>]

On 8/20/16 4:30 AM, Joerg Sonnenberger wrote:
> The following reply was made to PR pkg/51424; it has been noted by GNATS.
> 
> From: Joerg Sonnenberger <joerg%bec.de@localhost>
> To: gnats-bugs%NetBSD.org@localhost
> Cc: joerg%NetBSD.org@localhost, gnats-admin%netbsd.org@localhost, pkgsrc-bugs%netbsd.org@localhost,
> 	will%worrbase.com@localhost
> Subject: Re: pkg/51424: pkgtools/libnbcompat string.h header does not
>  properly guard strdup definition
> Date: Sat, 20 Aug 2016 13:29:21 +0200
> 
>  On Sat, Aug 20, 2016 at 12:10:00AM +0000, William Orr wrote:
>  >  It's not that the configure test fails, it's that the configure test
>  >  doesn't define HAVE_DECL_STRDUP - it defines HAVE_STRDUP. Normally, this
>  >  would just shadow the declaration of strdup, but because strdup is a
>  >  macro on this system, the preprocessor mangles the definition in
>  >  nbcompat/string.h. When the header compilation check runs on
>  >  nbcompat/string.h, this results in a compilation failure.
>  
>  This is not true. When the detection works correctly, it does define
>  HAVE_DECL_STRDUP. This is *not* a test for a function, but for an actual
>  usable prototype and function.
>  
>  Joerg
>  
> 

Not sure what I'm missing. autoconf (when building pkgin) *does* set
HAVE_STRDUP, but *does not* set HAVE_DECL_STRDUP. None of the other
functions are guarded by a prefix. ./configure *does* throw errors when
the function is guarded by the HAVE_DECL_STRDUP macro, since strdup on
Fedora is a macro itself.

Why is strdup the only function that is guarded by a macro prefixed with
HAVE_DECL_ instead of HAVE_ ? Not super clear as to why on that front
either.