class.c: do not freeze meta-meta-class

* class.c (rb_freeze_singleton_class): should not propagate to
  meta-meta-class, and so on, which is shared with the original
  class.  fix occational exceptions.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47633 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 13 insertions, 0 deletions

diff --git a/class.c b/class.c
index d841328077..45e27d8c12 100644
--- a/class.c
+++ b/class.c
@@ -1578,6 +1578,19 @@ singleton_class_of(VALUE obj)
     return klass;
 }
 
+void
+rb_freeze_singleton_class(VALUE x)
+{
+    /* should not propagate to meta-meta-class, and so on */
+    if (!(RBASIC(x)->flags & FL_SINGLETON)) {
+	VALUE klass = RBASIC_CLASS(x);
+	klass = RCLASS_ORIGIN(klass);
+	if (FL_TEST(klass, (FL_SINGLETON|FL_FREEZE)) == FL_SINGLETON) {
+	    OBJ_FREEZE_RAW(klass);
+	}
+    }
+}
+
 /*!
  * Returns the singleton class of \a obj, or nil if obj is not a
  * singleton object.