proc.c: use already included ancestor iclass

* proc.c (umethod_bind): use the ancestor iclass instead of new
  iclass to get rid of infinite recursion, if the defined module
  is already included.  [ruby-core:62014] [Bug #9721]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45585 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Mon Apr 14 17:20:10 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* proc.c (umethod_bind): use the ancestor iclass instead of new
+	  iclass to get rid of infinite recursion, if the defined module
+	  is already included.  [ruby-core:62014] [Bug #9721]
+
 Sun Apr 13 12:46:58 2014  Tanaka Akira  <akr@fsij.org>
 
 	* bignum.c (SIZEOF_BDIGIT): Renamed from SIZEOF_BDIGITS.

proc.c

@@ -2044,7 +2044,13 @@ umethod_bind(VALUE method, VALUE recv)
     if (bound->me->def) bound->me->def->alias_count++;
     rclass = CLASS_OF(recv);
     if (BUILTIN_TYPE(bound->defined_class) == T_MODULE) {
-	rclass = rb_include_class_new(methclass, rclass);
+	VALUE ic = rb_class_search_ancestor(rclass, bound->defined_class);
+	if (ic) {
+	    rclass = ic;
+	}
+	else {
+	    rclass = rb_include_class_new(methclass, rclass);
+	}
     }
     bound->recv = recv;
     bound->rclass = rclass;

test/ruby/test_super.rb

@@ -469,11 +469,28 @@ class TestSuper < Test::Unit::TestCase
       end
     end
 
-    m = b.instance_method(:foo).bind(Object.new.extend(a))
+    um = b.instance_method(:foo)
+
+    m = um.bind(Object.new.extend(a))
     result = []
     assert_nothing_raised(NoMethodError, bug9721) do
       m.call(result)
     end
     assert_equal(%w[B A], result, bug9721)
+
+    bug9740 = '[ruby-core:62017] [Bug #9740]'
+
+    b.module_eval do
+      define_method(:foo) do |result|
+        um.bind(self).call(result)
+      end
+    end
+
+    result.clear
+    o = Object.new.extend(a).extend(b)
+    assert_nothing_raised(NoMethodError, SystemStackError, bug9740) do
+      o.foo(result)
+    end
+    assert_equal(%w[B A], result, bug9721)
   end
 end