backport from ruby_1_8

* bignum.c (bignorm): avoid segmentation.  a patch from Hiroyuki
  Ito <ZXB01226@nifty.com>.  [ruby-list:43012]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8_5@11354 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 1 deletions

diff --git a/bignum.c b/bignum.c
index 6a7a83c085..493550ff98 100644
--- a/bignum.c
+++ b/bignum.c
@@ -99,7 +99,10 @@ static VALUE
 bignorm(x)
     VALUE x;
 {
-    if (!FIXNUM_P(x)) {
+    if (FIXNUM_P(x)) {
+      return x;
+    }
+    else if (TYPE(x) == T_BIGNUM) {
 	long len = RBIGNUM(x)->len;
 	BDIGIT *ds = BDIGITS(x);