* random.c (limited_rand): expands to long before shift so that

  the result does not overflow.


git-svn-id: http://svn.ruby-lang.org/repos/ruby/trunk@24029 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 7 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 2e659f3cb..7440bcc23 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Jul 11 02:37:37 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* random.c (limited_rand): expands to long before shift so tha
+	  the result does not overflow.
+
 Sat Jul 11 00:16:27 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* random.c (rand_init): got rid of buffer overflow.
diff --git a/random.c b/random.c
index 3ae919727..bcc16aa5b 100644
--- a/random.c
+++ b/random.c
@@ -414,8 +414,8 @@ limited_rand(struct MT *mt, unsigned long limit)
   retry:
     val = 0;
     for (i = SIZEOF_LONG/4-1; 0 <= i; i--) {
-        if (mask >> (i * 32)) {
-            val |= genrand_int32(mt) << (i * 32);
+        if ((mask >> (i * 32)) & 0xffffffff) {
+            val |= (unsigned long)genrand_int32(mt) << (i * 32);
             val &= mask;
             if (limit < val)
                 goto retry;