Re: Gnulib's alloca.h used even when there is a system header

[Eli Zaretskii]

> From: Bruno Haible <address@hidden>
> Cc: Eli Zaretskii <address@hidden>, address@hidden, address@hidden
> Date: Sun, 10 Mar 2019 20:03:33 +0100
> 
> So, Gnulib's alloca.h and the system's alloca.h are both included, and
> the system's alloca.h comes last. To avoid this kind of trouble, we
> need to make use of '#include_next <alloca.h>'. I think this patch
> should do it. Can you please review it, Eli?

It LGTM, since I already succeeded to build that package with this:

> +#  if (defined _WIN32 && ! defined __CYGWIN__) && @HAVE_ALLOCA_H@

replaced by just "#if HAVE_ALLOCA_H", and because the 2 additional
conditions you propose are obviously true for MinGW.

> +  if test $ac_cv_working_alloca_h = yes; then
> +    HAVE_ALLOCA_H=1
> +  else
> +    HAVE_ALLOCA_H=0
> +  fi
> +  AC_SUBST([HAVE_ALLOCA_H])
>  ])

This cannot hurt, but in the case in point the package was already
testing for alloca.h, and defined HAVE_ALLOCA_H by itself.

Thanks.