--- src/lib/fte/device.c.orig	Thu Jul 29 19:09:59 1993
+++ src/lib/fte/device.c	Thu Sep 30 13:16:51 2004
@@ -619,7 +619,7 @@
 	n2 = names;
     }
 
-    if (!n2 || !eq(n2->pn_op->op_name, "=")) {
+    if (!n2 || !n2->pn_op || !eq(n2->pn_op->op_name, "=")) {
 	fprintf(cp_err, "alter: don't understand \"%s\"\n", names->pn_name);
 	fprintf(cp_err, "usage: alter dev param = expression\n");
 	fprintf(cp_err, "  or   alter @dev[param] = expression\n");
@@ -661,7 +661,9 @@
     }
 
     dv = ft_evaluate(n2->pn_right);
-    free_pnode(names);
+    /* prevent names from getting freed twice
+       Guenther Roehrich 22-Jan-99 */
+    /* free_pnode(names); */
     if (!dv)
 	return;
     if (dv->v_length < 1) {