On Wed, 29 Jan 2020 16:34:28 +0100
Corinna Vinschen wrote:
> On Jan 29 16:32, Corinna Vinschen wrote:
> > On Jan 29 22:46, Takashi Yano wrote:
> > > --- m4/fseeko.m4.orig   2020-01-29 21:39:37.280507900 +0900
> > > +++ m4/fseeko.m4        2020-01-29 21:36:29.263747100 +0900
> > > @@ -30,16 +30,19 @@
> > >      HAVE_FSEEKO=0
> > >    else
> > >      if test $WINDOWS_64_BIT_OFF_T = 1; then
> 
> This makes me a bit suspicious... it looks like a check only
> required for native builds, not for Cygwin.

I think REPLACE_FSEEKO is set to 1 not here,

> > >      m4_ifdef([gl_FUNC_FFLUSH_STDIN], [
> > >        gl_FUNC_FFLUSH_STDIN
> > >        case "$gl_cv_func_fflush_stdin" in
> > >          *yes) ;;
> > > -        *) REPLACE_FSEEKO=1 ;;
> > > +        dnl *) REPLACE_FSEEKO=1 ;;
> > > +        *) REPLACE_FSEEKO=0 ;;
> > >        esac

but here.

gl_cv_func_fflush_stdin is set here in configure by:

if ac_fn_c_try_run "$LINENO"; then :
  gl_cv_func_fflush_stdin=yes
else
  gl_cv_func_fflush_stdin=no
fi

and the test code for this decision is as attached. conftest.c
returns 0 in cygwin 3.0.7, while cygwin with commit 59362c80e3a
returns 5.

I am not sure why segfault occurs if fseeko is replaced.
Probably due to a bug in octave or cygwin.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>