sqrt() error checking bug fixed.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4445 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 11 insertions, 6 deletions

diff --git a/ext/bigdecimal/bigdecimal.c b/ext/bigdecimal/bigdecimal.c
index 6ae02c6748..099331682b 100644
--- a/ext/bigdecimal/bigdecimal.c
+++ b/ext/bigdecimal/bigdecimal.c
@@ -3624,18 +3624,23 @@ VpSqrt(Real *y, Real *x)
     S_LONG nr;
     double val;
 
+    /* Zero, NaN or Infinity ? */
+    if(!VpHasVal(x)) {
+        if(VpIsZero(x)||VpGetSign(x)>0) {
+            VpAsgn(y,x,1);
+            goto Exit;
+        }
+        VpSetNaN(y);
+        return VpException(VP_EXCEPTION_OP,"(VpSqrt) SQRT(NaN or negative value)",0);
+        goto Exit;
+    }
+
      /* Negative ? */
     if(VpGetSign(x) < 0) {
         VpSetNaN(y);
         return VpException(VP_EXCEPTION_OP,"(VpSqrt) SQRT(negative value)",0);
     }
 
-    /* NaN or Infinity ? */
-    if(!VpHasVal(x)) {
-        VpAsgn(y,x,1);
-        goto Exit;
-    }
-
     /* One ? */
     if(VpIsOne(x)) {
         VpSetOne(y);