gettext 0.14.1 po/Makefile.in.in uses $(top_builddir) but no defn

[Paul Eggert]

A build of an experimental version of Bison, using gettext 0.14.1,
automake 1.8.4, and autoconf 2.59, failed as follows:

Making all in po
make[2]: Entering directory `/home/eggert/src/gnu/bison-gnulib-tmp/po'
make[2]: *** No rule to make target `/config.status', needed by `Makefile'.  
Stop.

I tracked it down to the fact that po/Makefile.in.in, as installed by
"autoreconf --verbose --install --force", uses $(top_builddir) without
defining it.

I worked around the problem by prepending the following line to
po/Makefile.in.in:

top_builddir = @top_builddir@

I see this problem has been reported before, in
<http://mail.gnu.org/archive/html/bug-gnu-utils/2002-06/msg00066.html>
but that bug report had some other symptoms so perhaps this problem
was missed in it.