PH lookup fails fast when the subject string length is out of range.

src/ph.c

@@ -360,8 +360,9 @@ PH_Lookup(const struct ph * const restrict ph,
 
 	len = strlen(subject);
 	h = hash(ph->h1, subject, len);
-	if (h != UINT_MAX)
-		idx = ph->tbl[h].idx;
+	if (h == UINT_MAX)
+		return (UINT_MAX);
+	idx = ph->tbl[h].idx;
 	if (vbit_test(ph->collision, h)) {
 		struct hash *h2 = ph->tbl[h].h2;
 		CHECK_OBJ_NOTNULL(h2, HASH_MAGIC);