Make sure that an empty po/POTFILES.in file exists at configure time,

otherwise no Makefile is generated in the po dir and compilation fails.
Once the empty file served the purpose, remove it in order to
immediately trigger its regeneration, which would only happen after
updating one of the Makefile.am files.


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@20527 a592a061-630c-0410-9148-cb99ea01b6c8

configure.ac

@@ -33,6 +33,9 @@ for file in config/install-sh config/mkinstalldirs ; do
   chmod 755 ${srcdir}/${file}
 done
 
+### Provide a dummy POTFILES.in in po in order to mark it as a PO directory
+test -f ${srcdir}/po/POTFILES.in || touch ${srcdir}/po/POTFILES.in
+
 ### Check for programs
 AC_PROG_MAKE_SET
 AC_PROG_INSTALL

m4/po.m4

@@ -114,6 +114,13 @@ AC_DEFUN([AM_PO_SUBDIRS],
           test -n "$as_me" && echo "$as_me: creating $ac_dir/POTFILES" || echo "creating $ac_dir/POTFILES"
           cat "$ac_given_srcdir/$ac_dir/POTFILES.in" | sed -e "/^#/d" -e "/^[ 	]*\$/d" -e "s,.*,     $top_srcdir/& \\\\," | sed -e "\$s/\(.*\) \\\\/\1/" > "$ac_dir/POTFILES"
           POMAKEFILEDEPS="POTFILES.in"
+          # Remove POTFILES.in if it is empty, such that it can be
+          # correctly rebuilt later.
+          if test -s "$ac_given_srcdir/$ac_dir/POTFILES.in"; then
+            : ;
+          else
+            rm -f "$ac_given_srcdir/$ac_dir/POTFILES.in"  
+          fi
           # ALL_LINGUAS, POFILES, UPDATEPOFILES, DUMMYPOFILES, GMOFILES depend
           # on $ac_dir but don't depend on user-specified configuration
           # parameters.