--- ray/src/cal/cnt.c	2022/04/21 02:52:40	1.6
+++ ray/src/cal/cnt.c	2022/04/22 15:50:34	1.7
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: cnt.c,v 1.6 2022/04/21 02:52:40 greg Exp $";
+static const char	RCSid[] = "$Id: cnt.c,v 1.7 2022/04/22 15:50:34 greg Exp $";
 #endif
 /*
  *  cnt.c - simple counting program.
@@ -161,9 +161,11 @@ incr_counter(uby8 *ctrp, int n)
 {
 	n = tree_br[n].cntr_siz;
 
-	while (n-- > 0)			/* LSB first */
-		if (++(*ctrp++))
-			break;
+	while (++(*ctrp++))		/* LSB first */
+		if (--n <= 0) {
+			fputs("Shuffle occupancy overflow!\n", stderr);
+			exit(1);	/* means we sized something wrong */
+		}
 }