merges r28751 from trunk into ruby_1_9_2.

--
* numeric.c (flo_cmp): honor the result of infinite? method of the
  other.  [ruby-core:31470]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@28788 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 7 insertions, 3 deletions

diff --git a/numeric.c b/numeric.c
index fdea3ce50c..d291a6dd85 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1016,7 +1016,7 @@ rb_dbl_cmp(double a, double b)
 static VALUE
 flo_cmp(VALUE x, VALUE y)
 {
-    double a, b;
+    double a, b, i;
 
     a = RFLOAT_VALUE(x);
     if (isnan(a)) return Qnil;
@@ -1038,8 +1038,12 @@ flo_cmp(VALUE x, VALUE y)
 	break;
 
       default:
-	if (isinf(a) && (!rb_respond_to(y, rb_intern("infinite?")) ||
-			 !RTEST(rb_funcall(y, rb_intern("infinite?"), 0, 0)))) {
+	if (isinf(a) && (i = rb_check_funcall(y, rb_intern("infinite?"), 0, 0)) != Qundef) {
+	    if (RTEST(i)) {
+		int j = rb_cmpint(i, x, y);
+		j = (a > 0.0) ? (j > 0 ? 0 : +1) : (j < 0 ? 0 : -1);
+		return INT2FIX(j);
+	    }
 	    if (a > 0.0) return INT2FIX(1);
 	    return INT2FIX(-1);
 	}