diff -up cracklib-2.9.6/lib/packlib.c.lookup cracklib-2.9.6/lib/packlib.c

--- cracklib-2.9.6/lib/packlib.c.lookup	2018-10-10 14:19:06.988958835 +0200

+++ cracklib-2.9.6/lib/packlib.c	2018-11-26 16:04:34.648256614 +0100

@@ -585,12 +585,11 @@ fprintf(stderr, "look for (%s)\n", strin

     fprintf(stderr, "---- %lu, %lu ----\n", lwm, hwm);

 #endif

-    middle = lwm + ((hwm - lwm + 1) / 2);

-

     for (;;)

     {

 	int cmp;

+	middle = lwm + ((hwm - lwm + 1) / 2);

 #if DEBUG

 	fprintf(stderr, "lwm = %lu,  middle = %lu,  hwm = %lu\n", lwm, middle, hwm);

@@ -617,24 +616,28 @@ fprintf(stderr, "look for (%s)\n", strin

 	    return(middle);

         }

-        if (middle == hwm)

-        {

-#if DEBUG

-		fprintf(stderr, "at terminal subdivision, stopping search\n");

-#endif

-		break;

-        }

-

 	if (cmp < 0)

 	{

-	    hwm = middle;

-	    middle = lwm + ((hwm - lwm ) / 2);

-	}

+	    if (middle == lwm)

+	    {

+#if DEBUG 

+		fprintf(stderr, "at terminal subdivision from right, stopping search\n");

+#endif

+		break;

+	    }

+	    hwm = middle - 1;

+	} 

 	else if (cmp > 0)

 	{

-	    lwm = middle;

-	    middle = lwm + ((hwm - lwm + 1) / 2);

-	}

+	    if (middle == hwm)

+	    {

+#if DEBUG 

+		fprintf(stderr, "at terminal subdivision from left, stopping search\n");

+#endif

+		break;

+	    }

+	    lwm = middle + 1;

+	} 

     }

     return (PW_WORDS(pwp));