+# Checking the output filenames. -*- Autotest -*-
+# Copyright 2002 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+# 02111-1307, USA.
+
+AT_BANNER([[Input Processing.]])
+
+# Mostly test that we are robust to mistakes.
+
+## ------------ ##
+## Invalid $n. ##
+## ------------ ##
+
+
+AT_SETUP([Invalid $n])
+
+AT_DATA([input.y],
+[[%%
+exp: { $$ = $1 ; }
+]])
+
+AT_CHECK([bison input.y], [1], [],
+[[input.y:2: invalid $ value
+]])
+
+AT_CLEANUP
+
+
+## ------------ ##
+## Invalid @n. ##
+## ------------ ##
+
+
+AT_SETUP([Invalid @n])
+
+AT_DATA([input.y],
+[[%%
+exp: { @$ = @1 ; }
+]])
+
+AT_CHECK([bison input.y], [1], [],
+[[input.y:2: invalid @ value
+]])
+
+AT_CLEANUP