diff -ur patch-2.5~/inp.c patch-2.5/inp.c
--- patch-2.5~/inp.c	Mon Jul 21 14:59:46 1997
+++ patch-2.5/inp.c	Sat Sep 16 11:29:35 2000
@@ -58,8 +58,11 @@
 re_input()
 {
     if (using_plan_a) {
-	free (i_buffer);
-	free (i_ptr);
+	if (NULL != i_buffer) {
+		free (i_buffer);
+		free (i_ptr);
+		i_buffer = i_ptr = NULL;
+	}
     }
     else {
 	close (tifd);