object.c: no TypeError at special const clone

* object.c (rb_obj_clone2): no longer raise a TypeError for
  special constants, and return itself instead.  however, if
  freeze option is false, raise an ArgumentError.  [Feature#12979]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56929 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 1 deletions

diff --git a/object.c b/object.c
index 7075e13683..a1dcf830e7 100644
--- a/object.c
+++ b/object.c
@@ -346,7 +346,9 @@ rb_obj_clone2(int argc, VALUE *argv, VALUE obj)
     }
 
     if (rb_special_const_p(obj)) {
-        rb_raise(rb_eTypeError, "can't clone %s", rb_obj_classname(obj));
+	if (kwfreeze == Qfalse)
+	    rb_raise(rb_eArgError, "can't unfreeze %s", rb_obj_classname(obj));
+	return obj;
     }
     clone = rb_obj_alloc(rb_obj_class(obj));
     RBASIC(clone)->flags &= (FL_TAINT|FL_PROMOTED0|FL_PROMOTED1);