[bug-gettext] missing top_builddir def in Makefile.in.in

[Samuel Thibault]

Hello,

When generating po/Makefile.in.in in my project, that file references
top_builddir in the Makefile dependency:

Makefile: Makefile.in.in Makevars $(top_builddir)/config.status @POMAKEFILEDEPS@
        cd $(top_builddir) \
          && @SHELL@ ./config.status $(subdir)/address@hidden po-directories

but that is not defined in the file:

srcdir = @srcdir@
top_srcdir = @top_srcdir@
VPATH = @srcdir@

etc.

Samuel