merge revision(s) 6118e8a47394409b53164b60e79fadf348b97db3, dc64448202299633a235f310b8bf2192263f274f: [Backport #20716]

	Fix method caching bug when including/prepend module A that prepends module B

	Fix by always adding the generated iclass to the subclasses list,
	otherwise the method cache for the iclass is not cleared when
	the method in the module is overwritten.

	Fixes [Bug #20716]

	Remove an unused variable

3 files changed, 34 insertions, 9 deletions

diff --git a/class.c b/class.c
index f84c38bc73..24d78a2751 100644
--- a/class.c
+++ b/class.c
@@ -1213,7 +1213,7 @@ static int
 do_include_modules_at(const VALUE klass, VALUE c, VALUE module, int search_super, bool check_cyclic)
 {
     VALUE p, iclass, origin_stack = 0;
-    int method_changed = 0, add_subclass;
+    int method_changed = 0;
     long origin_len;
     VALUE klass_origin = RCLASS_ORIGIN(klass);
     VALUE original_klass = klass;
@@ -1277,7 +1277,6 @@ do_include_modules_at(const VALUE klass, VALUE c, VALUE module, int search_super
         iclass = rb_include_class_new(module, super_class);
         c = RCLASS_SET_SUPER(c, iclass);
         RCLASS_SET_INCLUDER(iclass, klass);
-        add_subclass = TRUE;
         if (module != RCLASS_ORIGIN(module)) {
             if (!origin_stack) origin_stack = rb_ary_hidden_new(2);
             VALUE origin[2] = {iclass, RCLASS_ORIGIN(module)};
@@ -1288,14 +1287,11 @@ do_include_modules_at(const VALUE klass, VALUE c, VALUE module, int search_super
             RCLASS_SET_ORIGIN(RARRAY_AREF(origin_stack, (origin_len -= 2)), iclass);
             RICLASS_SET_ORIGIN_SHARED_MTBL(iclass);
             rb_ary_resize(origin_stack, origin_len);
-            add_subclass = FALSE;
         }
 
-        if (add_subclass) {
-            VALUE m = module;
-            if (BUILTIN_TYPE(m) == T_ICLASS) m = METACLASS_OF(m);
-            rb_module_add_to_subclasses_list(m, iclass);
-        }
+        VALUE m = module;
+        if (BUILTIN_TYPE(m) == T_ICLASS) m = METACLASS_OF(m);
+        rb_module_add_to_subclasses_list(m, iclass);
 
         if (BUILTIN_TYPE(klass) == T_MODULE && FL_TEST(klass, RMODULE_IS_REFINEMENT)) {
             VALUE refined_class =
diff --git a/test/ruby/test_super.rb b/test/ruby/test_super.rb
index 6a575b88c5..08be568660 100644
--- a/test/ruby/test_super.rb
+++ b/test/ruby/test_super.rb
@@ -605,6 +605,35 @@ class TestSuper < Test::Unit::TestCase
     }
   end
 
+  def test_super_with_included_prepended_module_method_caching_bug_20716
+    a = Module.new do
+      def test(*args)
+        super
+      end
+    end
+
+    b = Module.new do
+      def test(a)
+        a
+      end
+    end
+
+    c = Class.new
+
+    b.prepend(a)
+    c.include(b)
+
+    assert_equal(1, c.new.test(1))
+
+    b.class_eval do
+      def test
+        :test
+      end
+    end
+
+    assert_equal(:test, c.new.test)
+  end
+
   class TestFor_super_with_modified_rest_parameter_base
     def foo *args
       args
diff --git a/version.h b/version.h
index 6c541c1cbe..9163f8decf 100644
--- a/version.h
+++ b/version.h
@@ -11,7 +11,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 5
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 228
+#define RUBY_PATCHLEVEL 229
 
 #include "ruby/version.h"
 #include "ruby/internal/abi.h"