Revert "Fix origin iclass pointer for modules"

This reverts commit c745a60634.

This triggers a VM assertion.  Reverting until the issue can be
debugged.

class.c

@@ -837,7 +837,7 @@ rb_include_class_new(VALUE module, VALUE super)
     RCLASS_M_TBL(OBJ_WB_UNPROTECT(klass)) =
       RCLASS_M_TBL(OBJ_WB_UNPROTECT(module)); /* TODO: unprotected? */
 
-    RCLASS_SET_ORIGIN(klass, klass);
+    RCLASS_SET_ORIGIN(klass, module == RCLASS_ORIGIN(module) ? klass : RCLASS_ORIGIN(module));
     if (BUILTIN_TYPE(module) == T_ICLASS) {
 	module = RBASIC(module)->klass;
     }
@@ -925,9 +925,8 @@ clear_module_cache_i(ID id, VALUE val, void *data)
 static int
 include_modules_at(const VALUE klass, VALUE c, VALUE module, int search_super)
 {
-    VALUE p, iclass, origin_stack = 0;
+    VALUE p, iclass;
-    int method_changed = 0, constant_changed = 0, add_subclass;
+    int method_changed = 0, constant_changed = 0;
-    long origin_len;
     struct rb_id_table *const klass_m_tbl = RCLASS_M_TBL(RCLASS_ORIGIN(klass));
     VALUE original_klass = klass;
 
@@ -980,24 +979,11 @@ 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_tmp_new(2);
-            VALUE origin[2] = {iclass, RCLASS_ORIGIN(module)};
-            rb_ary_cat(origin_stack, origin, 2);
-        }
-        else if (origin_stack && (origin_len = RARRAY_LEN(origin_stack)) > 1 &&
-                 RARRAY_AREF(origin_stack, origin_len - 1) == module) {
-            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;
-        }
 
 	{
 	    VALUE m = module;
             if (BUILTIN_TYPE(m) == T_ICLASS) m = RBASIC(m)->klass;
-            if (add_subclass) rb_module_add_to_subclasses_list(m, iclass);
+            rb_module_add_to_subclasses_list(m, iclass);
 	}
 
 	if (FL_TEST(klass, RMODULE_IS_REFINEMENT)) {
@@ -1107,7 +1093,7 @@ rb_mod_included_modules(VALUE mod)
     VALUE origin = RCLASS_ORIGIN(mod);
 
     for (p = RCLASS_SUPER(mod); p; p = RCLASS_SUPER(p)) {
-        if (p != origin && RCLASS_ORIGIN(p) == p && BUILTIN_TYPE(p) == T_ICLASS) {
+	if (p != origin && BUILTIN_TYPE(p) == T_ICLASS) {
 	    VALUE m = RBASIC(p)->klass;
 	    if (RB_TYPE_P(m, T_MODULE))
 		rb_ary_push(ary, m);

gc.c

@@ -2815,9 +2815,7 @@ obj_free(rb_objspace_t *objspace, VALUE obj)
 	break;
       case T_ICLASS:
 	/* Basically , T_ICLASS shares table with the module */
-        if (FL_TEST(obj, RICLASS_IS_ORIGIN) &&
+	if (FL_TEST(obj, RICLASS_IS_ORIGIN)) {
-                !FL_TEST(obj, RICLASS_ORIGIN_SHARED_MTBL)) {
-            /* Method table is not shared for origin iclasses of classes */
 	    rb_id_table_free(RCLASS_M_TBL(obj));
 	}
 	if (RCLASS_CALLABLE_M_TBL(obj) != NULL) {
@@ -3913,8 +3911,7 @@ obj_memsize_of(VALUE obj, int use_all_types)
 	}
 	break;
       case T_ICLASS:
-        if (FL_TEST(obj, RICLASS_IS_ORIGIN) &&
+	if (FL_TEST(obj, RICLASS_IS_ORIGIN)) {
-                !FL_TEST(obj, RICLASS_ORIGIN_SHARED_MTBL)) {
 	    if (RCLASS_M_TBL(obj)) {
 		size += rb_id_table_memsize(RCLASS_M_TBL(obj));
 	    }
@@ -5435,8 +5432,7 @@ gc_mark_children(rb_objspace_t *objspace, VALUE obj)
 	break;
 
       case T_ICLASS:
-        if (FL_TEST(obj, RICLASS_IS_ORIGIN) &&
+	if (FL_TEST(obj, RICLASS_IS_ORIGIN)) {
-                !FL_TEST(obj, RICLASS_ORIGIN_SHARED_MTBL)) {
 	    mark_m_tbl(objspace, RCLASS_M_TBL(obj));
 	}
         if (RCLASS_SUPER(obj)) {
@@ -8300,8 +8296,7 @@ gc_update_object_references(rb_objspace_t *objspace, VALUE obj)
         break;
 
       case T_ICLASS:
-        if (FL_TEST(obj, RICLASS_IS_ORIGIN) &&
+        if (FL_TEST(obj, RICLASS_IS_ORIGIN)) {
-                !FL_TEST(obj, RICLASS_ORIGIN_SHARED_MTBL)) {
             update_m_tbl(objspace, RCLASS_M_TBL(obj));
         }
         if (RCLASS_SUPER((VALUE)obj)) {

internal/class.h

@@ -95,10 +95,9 @@ typedef struct rb_classext_struct rb_classext_t;
 #endif
 #define RCLASS_INCLUDER(c) (RCLASS_EXT(c)->includer)
 
-#define RICLASS_IS_ORIGIN FL_USER5
 #define RCLASS_CLONED     FL_USER6
+#define RICLASS_IS_ORIGIN FL_USER5
 #define RCLASS_REFINED_BY_ANY FL_USER7
-#define RICLASS_ORIGIN_SHARED_MTBL FL_USER8
 
 /* class.c */
 void rb_class_subclass_add(VALUE super, VALUE klass);
@@ -121,7 +120,6 @@ VALUE rb_singleton_class_get(VALUE obj);
 int rb_class_has_methods(VALUE c);
 void rb_undef_methods_from(VALUE klass, VALUE super);
 static inline void RCLASS_SET_ORIGIN(VALUE klass, VALUE origin);
-static inline void RICLASS_SET_ORIGIN_SHARED_MTBL(VALUE iclass);
 static inline VALUE RCLASS_SUPER(VALUE klass);
 static inline VALUE RCLASS_SET_SUPER(VALUE klass, VALUE super);
 static inline void RCLASS_SET_INCLUDER(VALUE iclass, VALUE klass);
@@ -138,12 +136,6 @@ RCLASS_SET_ORIGIN(VALUE klass, VALUE origin)
     if (klass != origin) FL_SET(origin, RICLASS_IS_ORIGIN);
 }
 
-static inline void
-RICLASS_SET_ORIGIN_SHARED_MTBL(VALUE iclass)
-{
-    FL_SET(iclass, RICLASS_ORIGIN_SHARED_MTBL);
-}
-
 static inline void
 RCLASS_SET_INCLUDER(VALUE iclass, VALUE klass)
 {

test/ruby/test_module.rb

@@ -479,28 +479,6 @@ class TestModule < Test::Unit::TestCase
     assert_raise(ArgumentError) { Module.new { include } }
   end
 
-  def test_gc_prepend_chain
-    assert_separately([], <<-EOS)
-      10000.times { |i|
-        m1 = Module.new do
-          def foo; end
-        end
-        m2 = Module.new do
-          prepend m1
-          def bar; end
-        end
-        m3 = Module.new do
-          def baz; end
-          prepend m2
-        end
-        Class.new do
-          prepend m3
-        end
-      }
-      GC.start
-    EOS
-  end
-
   def test_include_into_module_already_included
     c = Class.new{def foo; [:c] end}
     modules = lambda do ||
@@ -562,16 +540,6 @@ class TestModule < Test::Unit::TestCase
     assert_equal([Comparable, Kernel], String.included_modules - mixins)
   end
 
-  def test_included_modules_with_prepend
-    m1 = Module.new
-    m2 = Module.new
-    m3 = Module.new
-
-    m2.prepend m1
-    m3.include m2
-    assert_equal([m1, m2], m3.included_modules)
-  end
-
   def test_instance_methods
     assert_equal([:user, :user2], User.instance_methods(false).sort)
     assert_equal([:user, :user2, :mixin].sort, User.instance_methods(true).sort)
@@ -2075,33 +2043,6 @@ class TestModule < Test::Unit::TestCase
     assert_include(im, mixin, bug8025)
   end
 
-  def test_prepended_module_with_super_and_alias
-    bug16736 = '[Bug #16736]'
-
-    a = labeled_class("A") do
-      def m; "A"; end
-    end
-    m = labeled_module("M") do
-      prepend Module.new
-
-      def self.included(base)
-        base.alias_method :base_m, :m
-      end
-
-      def m
-        super + "M"
-      end
-
-      def m2
-        base_m
-      end
-    end
-    b = labeled_class("B", a) do
-      include m
-    end
-    assert_equal("AM", b.new.m2, bug16736)
-  end
-
   def test_prepend_super_in_alias
     bug7842 = '[Bug #7842]'