random_int: Fix power of two check.

(x & ~x) is always 0.
((x & (~x + 1)) != x) works.
((x & (x - 1)) != 0) works too.

diff --git a/ext/standard/random.c b/ext/standard/random.c
index 12c25031d83a446585b9b50fefdef30df58bc3be..4a1adbfb0263043371344c2a23fcfd1a30d2520e 100644 (file)
--- a/ext/standard/random.c
+++ b/ext/standard/random.c
@@ -182,7 +182,7 @@ PHP_FUNCTION(random_int)
        umax++;
 
        /* Powers of two are not biased */
-       if ((umax & ~umax) != umax) {
+       if ((umax & (umax - 1)) != 0) {
                /* Ceiling under which ZEND_LONG_MAX % max == 0 */
                zend_ulong limit = ZEND_ULONG_MAX - (ZEND_ULONG_MAX % umax) - 1;