merges r23609 from trunk into ruby_1_9_1.

--
* ext/bigdecimal/bigdecimal.c (BigDecimal_to_f): returns Inf if
  exp is bigger than DBL_MANT_DIG.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_1@23765 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 5 insertions, 3 deletions

diff --git a/ext/bigdecimal/bigdecimal.c b/ext/bigdecimal/bigdecimal.c
index 3472970fd5..061ec088ea 100644
--- a/ext/bigdecimal/bigdecimal.c
+++ b/ext/bigdecimal/bigdecimal.c
@@ -604,16 +604,18 @@ BigDecimal_to_f(VALUE self)
     volatile VALUE str;
 
     GUARD_OBJ(p,GetVpValue(self,1));
-    if(VpVtoD(&d, &e, p)!=1) return rb_float_new(d);
+    if (VpVtoD(&d, &e, p)!=1) return rb_float_new(d);
+    if (e > DBL_MAX_10_EXP) goto erange;
     str = rb_str_new(0, VpNumOfChars(p,"E"));
     buf = RSTRING_PTR(str);
     VpToString(p, buf, 0, 0);
     errno = 0;
     d = strtod(buf, 0);
     if(errno == ERANGE) {
+      erange:
        VpException(VP_EXCEPTION_OVERFLOW,"BigDecimal to Float conversion",0);
-       if(d>0.0) return rb_float_new(DBL_MAX);
-       else      return rb_float_new(-DBL_MAX);
+       if(d>0.0) d = VpGetDoublePosInf();
+       else      d = VpGetDoubleNegInf();
     }
     return rb_float_new(d);
 }