Re: AC_FUNC_MMAP lacks <unistd.h> include?

* Paul Eggert:

> diff --git a/lib/autoconf/functions.m4 b/lib/autoconf/functions.m4
> index 5a0f0185..3d6e4aca 100644
> --- a/lib/autoconf/functions.m4
> +++ b/lib/autoconf/functions.m4

> +#ifndef getpagesize
> +# ifdef _SC_PAGESIZE
> +#  define getpagesize() sysconf (_SC_PAGESIZE)
> +# elif defined _SC_PAGE_SIZE
> +#  define getpagesize() sysconf (_SC_PAGE_SIZE)
> +# elif HAVE_GETPAGESIZE
> +int getpagesize ();

Isn't this a bit weird?  Why can't we rely on the HAVE_GETPAGESIZE
check?  Shouldn't <unistd.h> come from [AC_INCLUDES_DEFAULT]?

Thanks,
Florian