object.c: forbid uninitialized class

* object.c (rb_class_initialize): forbid inheriting uninitialized
  class.  another class tree not based on BasicObject cannot exist.
  [ruby-core:47148][Bug #6863]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36714 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 11 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 986c5e2151..87be08978d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Thu Aug 16 19:15:23 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* object.c (rb_class_initialize): forbid inheriting uninitialized
+	  class.  another class tree not based on BasicObject cannot exist.
+	  [ruby-core:47148][Bug #6863]
+
 Thu Aug 16 11:52:06 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* test/-ext-/test_printf.rb (Test_SPrintf#test_{taint,untrust}): use
diff --git a/object.c b/object.c
index b7e1b58c81..73f76fa753 100644
--- a/object.c
+++ b/object.c
@@ -1616,6 +1616,9 @@ rb_class_initialize(int argc, VALUE *argv, VALUE klass)
     else {
 	rb_scan_args(argc, argv, "01", &super);
 	rb_check_inheritable(super);
+	if (super != rb_cBasicObject && !RCLASS_SUPER(super)) {
+	    rb_raise(rb_eTypeError, "can't inherit uninitialized class");
+	}
     }
     RCLASS_SUPER(klass) = super;
     rb_make_metaclass(klass, RBASIC(super)->klass);
diff --git a/test/ruby/test_class.rb b/test/ruby/test_class.rb
index 12f78ddabc..88fe79bb11 100644
--- a/test/ruby/test_class.rb
+++ b/test/ruby/test_class.rb
@@ -203,6 +203,8 @@ class TestClass < Test::Unit::TestCase
   def test_uninitialized
     assert_raise(TypeError) { Class.allocate.new }
     assert_raise(TypeError) { Class.allocate.superclass }
+    bug6863 = '[ruby-core:47148]'
+    assert_raise(TypeError, bug6863) { Class.new(Class.allocate) }
   end
 
   def test_nonascii_name