* 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_8@23611 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 9 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index dbecd88281..c02514e13f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jun  1 07:20:02 2009  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* ext/bigdecimal/bigdecimal.c (BigDecimal_to_f): returns Inf if
+	  exp is bigger than DBL_MANT_DIG.
+
 Sun May 31 23:28:00 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/mkmf.rb (create_makefile): checks for duplication of source
diff --git a/ext/bigdecimal/bigdecimal.c b/ext/bigdecimal/bigdecimal.c
index bbc7953b87..5cb4d95fab 100644
--- a/ext/bigdecimal/bigdecimal.c
+++ b/ext/bigdecimal/bigdecimal.c
@@ -592,14 +592,16 @@ BigDecimal_to_f(VALUE self)
 
     GUARD_OBJ(p,GetVpValue(self,1));
     if(VpVtoD(&d, &e, p)!=1) return rb_float_new(d);
+    if (e > DBL_MAX_10_EXP) goto erange;
     buf = ALLOCA_N(char,(unsigned int)VpNumOfChars(p,"E"));
     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);
 }