Allow include before calling Module#initialize

This is to allow Module subclasses that include modules before
calling super in the subclass's initialize.

Remove rb_module_check_initializable from Module#initialize.
Module#initialize only calls module_exec if a block is passed,
it doesn't have other issues that would cause problems if
called multiple times or with an already initialized module.

Move initialization of super to Module#allocate, though I'm not
sure it is required there.  However, it's needed to be removed
from Module#initialize for this to work.

Fixes [Bug #18292]

1 files changed, 10 insertions, 0 deletions

diff --git a/test/ruby/test_module.rb b/test/ruby/test_module.rb
index e1524a5d81..b84a090fce 100644
--- a/test/ruby/test_module.rb
+++ b/test/ruby/test_module.rb
@@ -519,6 +519,16 @@ class TestModule < Test::Unit::TestCase
     assert_raise(ArgumentError) { Module.new { include } }
   end
 
+  def test_include_before_initialize
+    m = Class.new(Module) do
+      def initialize(...)
+        include Enumerable
+        super
+      end
+    end.new
+    assert_equal(true, m < Enumerable)
+  end
+
   def test_prepend_self
     m = Module.new
     assert_equal([m], m.ancestors)