Fix #71152: mt_rand() returns the different values from original mt19937ar.c #1681

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merged 2 commits into from Feb 17, 2016
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@@ -146,7 +146,7 @@ PHPAPI zend_long php_rand(void)
#define loBits(u) ((u) & 0x7FFFFFFFU) /* mask the highest bit of u */
#define mixBits(u, v) (hiBit(u)|loBits(v)) /* move hi bit of u to hi bit of v */
-#define twist(m,u,v) (m ^ (mixBits(u,v)>>1) ^ ((uint32_t)(-(int32_t)(loBit(u))) & 0x9908b0dfU))
+#define twist(m,u,v) (m ^ (mixBits(u,v)>>1) ^ ((uint32_t)(-(int32_t)(loBit(v))) & 0x9908b0dfU))
/* {{{ php_mt_initialize
*/
@@ -0,0 +1,53 @@
+--TEST--
+Test mt_rand() - returns the exact same values as mt19937ar.c
+--FILE--
+<?php
+
+mt_srand(12345678);
+
+for ($i=0; $i<16; $i++) {
+ echo mt_rand().PHP_EOL;
+}
+echo PHP_EOL;
+
+$x = 0;
+for ($i=0; $i<1024; $i++) {
+ $x ^= mt_rand();
+}
+echo $x.PHP_EOL;
+
+/*
+excpect values are obtained from original mt19937ar.c as follows:
+
+int i, x;
+init_genrand(12345678);
+for (i=0; i<16; i++) {
+ printf("%d\n", genrand_int31());
+}
+printf("\n");
+x = 0;
+for (i=0; i<1024; i++) {
+ x ^= genrand_int31();
+}
+printf("%d\n", x);
+*/
+?>
+--EXPECTF--
+527860569
+1711027313
+1280820687
+688176834
+770499160
+412773096
+813703253
+898651287
+52508912
+757323740
+511765911
+274407457
+833082629
+1923803667
+1461450755
+1301698200
+
+1612214270