automake 'dist' target distributes built source file

[Bruno Haible]

Hi,

automake-1.9.6 insists on distributing a file, although I have
  - not listed it in EXTRA_DIST,
  - listed it in BUILT_SOURCES and in CLEANFILES.

To reproduce:

============================== Makefile.am ============================
AUTOMAKE_OPTIONS = 1.5 foreign

include_HEADERS = gettext-po.h
EXTRA_DIST = gettext-po.h.in
BUILT_SOURCES = gettext-po.h
CLEANFILES = gettext-po.h

gettext-po.h: gettext-po.h.in
        cp $(srcdir)/gettext-po.h.in gettext-po.h-tmp
        mv gettext-po.h-tmp gettext-po.h
=======================================================================

============================= configure.ac ============================
AC_INIT
AC_CONFIG_SRCDIR(configure.ac)
AM_INIT_AUTOMAKE(foo, 0.0)
AC_CONFIG_FILES([Makefile])
AC_OUTPUT
=======================================================================

============================= gettext-po.h.in =========================
blabla
=======================================================================

$ aclocal
$ automake
$ autoconf
$ ./configure
$ make
$ make dist
$ tar tvfz foo-0.0.tar.gz 
drwxrwxrwx 101/100           0 2006-07-22 00:53 foo-0.0/
-rw-r--r-- 101/100         104 2006-07-22 00:53 foo-0.0/configure.ac
-rw-r--r-- 101/100       19832 2006-07-22 00:53 foo-0.0/aclocal.m4
-rw-r--r-- 101/100           7 2006-07-22 00:53 foo-0.0/gettext-po.h
-rw-r--r-- 101/100         259 2006-07-22 00:51 foo-0.0/Makefile.am
-rw-r--r-- 101/100       15096 2006-07-22 00:53 foo-0.0/Makefile.in
-rwxr-xr-x 101/100       88182 2006-07-22 00:53 foo-0.0/configure
-rw-r--r-- 101/100           7 2006-07-22 00:52 foo-0.0/gettext-po.h.in

I want to distribute gettext-po.h.in, but I don't want to distribute
gettext-po.h because it is actually platform dependent (not visible in
this small example here).

How do I need to write this? I hope I don't have to write an
'install-data-local' rule.

Bruno