ast.c: allocator of Node

* ast.c (Init_ast): undefine allocator of Node, as a method call
  on an uninitialized Node causes segfault.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64168 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ast.c

@@ -614,8 +614,7 @@ Init_ast(void)
      */
     rb_cNode = rb_define_class_under(rb_mAST, "Node", rb_cObject);
 
-    rb_define_alloc_func(rb_cNode, rb_ast_node_alloc);
-    rb_undef_method(CLASS_OF(rb_cNode), "new");
+    rb_undef_alloc_func(rb_cNode);
     rb_define_singleton_method(rb_mAST, "parse", rb_ast_s_parse, 1);
     rb_define_singleton_method(rb_mAST, "parse_file", rb_ast_s_parse_file, 1);
     rb_define_method(rb_cNode, "type", rb_ast_node_type, 0);

test/ruby/test_ast.rb

@@ -129,6 +129,10 @@ class TestAst < Test::Unit::TestCase
     end
   end
 
+  def test_allocate
+    assert_raise(TypeError) {RubyVM::AST::Node.allocate}
+  end
+
   def test_column_with_long_heredoc_identifier
     term = "A"*257
     ast = RubyVM::AST.parse("<<-#{term}\n""ddddddd\n#{term}\n")