* random.c (init_genrand): ensure invariant of mt->next and mt->left.

mt->next should always equal mt->state + N + 1 - mt->left.
  In fact, 'r = Random.new(0); r == r.dup' has returned false.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@24325 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Thu Jul 30 21:48:56 2009  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* random.c (init_genrand): ensure invariant of mt->next and mt->left.
+	  mt->next should always equal mt->state + N + 1 - mt->left.
+	  In fact, 'r = Random.new(0); r == r.dup' has returned false.
+
 Thu Jul 30 21:43:41 2009  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* random.c (random_bytes): use NUM2LONG instead of FIX2LONG because

random.c

@@ -98,7 +98,7 @@ init_genrand(struct MT *mt, unsigned int s)
         mt->state[j] &= 0xffffffff;  /* for >32 bit machines */
     }
     mt->left = 1;
-    mt->next = mt->state + N - 1;
+    mt->next = mt->state + N;
 }
 
 /* initialize by an array with array-length */