* array.c (flatten): use rb_obj_class instead of rb_class_of

  because rb_class_of may return a singleton class.
  [ruby-dev:49781] [Bug #12738]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56111 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 18 insertions, 0 deletions

diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index addce0d9ba..a19e22aab4 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -813,6 +813,15 @@ class TestArray < Test::Unit::TestCase
     assert_nothing_raised(RuntimeError, bug10748) {a.flatten(1)}
   end
 
+  def test_flattern_singleton_class
+    bug12738 = '[ruby-dev:49781] [Bug #12738]'
+    a = [[0]]
+    class << a
+      def m; end
+    end
+    assert_raise(NoMethodError, bug12738) { a.flatten.m }
+  end
+
   def test_flatten!
     a1 = @cls[ 1, 2, 3]
     a2 = @cls[ 5, 6 ]
@@ -850,6 +859,15 @@ class TestArray < Test::Unit::TestCase
     assert_nothing_raised(RuntimeError, bug10748) {a.flatten!(1)}
   end
 
+  def test_flattern_singleton_class!
+    bug12738 = '[ruby-dev:49781] [Bug #12738]'
+    a = [[0]]
+    class << a
+      def m; end
+    end
+    assert_nothing_raised(NameError, bug12738) { a.flatten!.m }
+  end
+
   def test_flatten_with_callcc
     need_continuation
     o = Object.new