* random.c (make_seed_value): fix leading-zero-guard condition on

  bdigit is smaller than 32bit.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27328 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 14 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index f36e3726a0..f83502684f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Apr 13 15:00:45 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* random.c (make_seed_value): fix leading-zero-guard condition on
+	  bdigit is smaller than 32bit.
+
 Tue Apr 13 13:57:36 2010  Keiju Ishitsuka  <keiju@ruby-lang.org>
 
 	* lib/irb/completion.rb (CompletionProc): fix [ruby-dev:40953]
diff --git a/random.c b/random.c
index 149069c76e..3fee535e97 100644
--- a/random.c
+++ b/random.c
@@ -516,18 +516,25 @@ fill_random_seed(unsigned int seed[DEFAULT_SEED_CNT])
 static VALUE
 make_seed_value(const void *ptr)
 {
+    const long len = DEFAULT_SEED_LEN/SIZEOF_BDIGITS;
     BDIGIT *digits;
     NEWOBJ(big, struct RBignum);
     OBJSETUP(big, rb_cBignum, T_BIGNUM);
 
     RBIGNUM_SET_SIGN(big, 1);
-    rb_big_resize((VALUE)big, DEFAULT_SEED_LEN / SIZEOF_BDIGITS + 1);
+    rb_big_resize((VALUE)big, len + 1);
     digits = RBIGNUM_DIGITS(big);
 
     MEMCPY(digits, ptr, char, DEFAULT_SEED_LEN);
 
     /* set leading-zero-guard if need. */
-    digits[RBIGNUM_LEN(big)-1] = digits[RBIGNUM_LEN(big)-2] <= 1 ? 1 : 0;
+    digits[len] =
+#if SIZEOF_INT32 / SIZEOF_BDIGITS > 1
+	digits[len-2] <= 1 && digits[len-1] == 0
+#else
+	digits[len-1] <= 1
+#endif
+	? 1 : 0;
 
     return rb_big_norm((VALUE)big);
 }