merge revision(s) 54970: [Backport #12367]

	* insns.def (defineclass): Also raise an error when redeclaring the
	  superclass of a class as Object and it has another superclass.
	  [Bug #12367] [ruby-core:75446]

	* test/ruby/test_class.rb: test for above.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@55402 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 19 insertions, 0 deletions

diff --git a/test/ruby/test_class.rb b/test/ruby/test_class.rb
index 81c11e6f88..59b720813c 100644
--- a/test/ruby/test_class.rb
+++ b/test/ruby/test_class.rb
@@ -375,6 +375,25 @@ class TestClass < Test::Unit::TestCase
     }
   end
 
+  define_method :test_invalid_reset_superclass do
+    class A; end
+    class SuperclassCannotBeReset < A
+    end
+    assert_equal A, SuperclassCannotBeReset.superclass
+
+    assert_raise_with_message(TypeError, /superclass mismatch/) {
+      class SuperclassCannotBeReset < String
+      end
+    }
+
+    assert_raise_with_message(TypeError, /superclass mismatch/, "[ruby-core:75446]") {
+      class SuperclassCannotBeReset < Object
+      end
+    }
+
+    assert_equal A, SuperclassCannotBeReset.superclass
+  end
+
   def test_cloned_singleton_method_added
     bug5283 = '[ruby-dev:44477]'
     added = []