Fix for #1238 and #1240 (work in progress)

gistfile1.diff

diff --git a/class.c b/class.c
index 8b18f71..e411aeb 100644
--- a/class.c
+++ b/class.c
@@ -23,6 +23,27 @@
 extern st_table *rb_class_tbl;
 extern VALUE rb_cRubyObject;
 
+VALUE
+rb_class_super(VALUE klass)
+{
+    if (klass == 0 || RCLASS_MODULE(klass)) {
+	return 0;
+    }
+    return (VALUE)class_getSuperclass((Class)klass);
+}
+
+void
+rb_class_set_super(VALUE klass, VALUE super)
+{
+    class_setSuperclass((Class)klass, (Class)super);
+}
+
+int
+rb_class_ismeta(VALUE klass)
+{
+    return class_isMetaClass((Class)klass);
+}
+
 void
 rb_objc_class_sync_version(Class ocklass, Class ocsuper)
 {
@@ -153,11 +174,7 @@ rb_objc_alloc_class(const char *name, VALUE super, VALUE flags, VALUE klass)
 	goto no_more_classes;
     }
 
-    if (super == 0) {
-	super = rb_cObject;
-    }
-
-    Class ocklass = objc_allocateClassPair((Class)super, ocname, sizeof(id));
+    Class ocklass = objc_allocateClassPair((Class)super, ocname, 0);
     if (ocklass == NULL) {
 	goto no_more_classes;
     }
@@ -170,7 +187,7 @@ rb_objc_alloc_class(const char *name, VALUE super, VALUE flags, VALUE klass)
 
     objc_registerClassPair(ocklass);
 
-    if (klass != 0) {
+    if (klass != 0 && super != 0) {
 	rb_objc_class_sync_version(ocklass, (Class)super);
     }
 
@@ -183,6 +200,9 @@ no_more_classes:
 VALUE
 rb_objc_create_class(const char *name, VALUE super)
 {
+    if (super == 0) {
+	super = rb_cObject;
+    }
     VALUE klass = rb_objc_alloc_class(name, super, T_CLASS, rb_cClass);
    
     if (super != rb_cNSObject && super != 0
@@ -503,12 +523,11 @@ rb_define_module_id(ID id)
 {
     VALUE mdl = rb_objc_alloc_class(id == 0 ? NULL : rb_id2name(id),
 	    rb_cObject, T_MODULE, rb_cModule);
-
-    if ((rb_mKernel != 0) && (id == 0)) {
-	/* because Module#initialize can accept a block */
-	rb_objc_define_method(*(VALUE *)mdl, "initialize", rb_mod_initialize, 0);
+    if (rb_mKernel != 0 && id == 0) {
+	// Because Module#initialize can accept a block.
+	rb_objc_define_method(*(VALUE *)mdl, "initialize",
+		rb_mod_initialize, 0);
     }
-
     return mdl;
 }
 
@@ -825,7 +844,7 @@ class_instance_method_list(int argc, VALUE *argv, VALUE mod, int (*func) (VALUE,
 	if (recur == Qfalse) {
 	   break;	   
 	}
-	mod = (VALUE)class_getSuperclass((Class)mod); 
+	mod = RCLASS_SUPER(mod);
     } 
 
     return ary;
diff --git a/eval.c b/eval.c
index 28bcd79..481589f 100644
--- a/eval.c
+++ b/eval.c
@@ -588,7 +588,7 @@ rb_mod_append_features(VALUE module, SEL sel, VALUE include)
 	}
 	m = RCLASS_SUPER(m);
     }
-    while (m == 0 || RCLASS_SINGLETON(m));
+    while (m != 0 && RCLASS_SINGLETON(m));
 
     return module;
 }
@@ -647,7 +647,7 @@ rb_extend_object(VALUE obj, VALUE module)
 	}
 	m = RCLASS_SUPER(m);
     }
-    while (m == 0 || RCLASS_SINGLETON(m));
+    while (m != 0 && RCLASS_SINGLETON(m));
 }
 
 /*
diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index ad7b1cb..8ca9f4b 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -428,9 +428,12 @@ struct RBasic {
     VALUE flags;
 };
 
-#define RCLASS_SUPER(m) ((VALUE)class_getSuperclass((Class)m))
-#define RCLASS_SET_SUPER(m, s) (class_setSuperclass((Class)m, (Class)s))
-#define RCLASS_META(m) (class_isMetaClass((Class)m))
+VALUE rb_class_super(VALUE klass);
+void rb_class_set_super(VALUE klass, VALUE super);
+int rb_class_ismeta(VALUE klass);
+#define RCLASS_SUPER(m) (rb_class_super((VALUE)m))
+#define RCLASS_SET_SUPER(m, s) (rb_class_set_super((VALUE)m, (VALUE)s))
+#define RCLASS_META(m) (rb_class_ismeta((VALUE)m))
 
 #define RFLOAT_VALUE(v) FIXFLOAT2DBL(v)
 #define DOUBLE2NUM(dbl)  rb_float_new(dbl)
diff --git a/variable.c b/variable.c
index 3f1dac5..62f9780 100644
--- a/variable.c
+++ b/variable.c
@@ -933,43 +933,16 @@ rb_copy_generic_ivar(VALUE clone, VALUE obj)
     }
 }
 
-static inline bool
-rb_class_has_ivar_dict(VALUE mod)
-{
-    const long v = RCLASS_VERSION(mod);
-    return (v & RCLASS_IS_RUBY_CLASS) == RCLASS_IS_RUBY_CLASS
-	&& (v & RCLASS_KVO_CHECK_DONE) != RCLASS_KVO_CHECK_DONE;
-}
-
-#define RCLASS_RUBY_IVAR_DICT(mod) \
-    (*(CFMutableDictionaryRef *) \
-     	((void *)mod + class_getInstanceSize(*(Class *)RCLASS_SUPER(mod))))
-
 CFMutableDictionaryRef 
 rb_class_ivar_dict(VALUE mod)
 {
-    if (rb_class_has_ivar_dict(mod)) {
-	return RCLASS_RUBY_IVAR_DICT(mod);
-    }
     return generic_ivar_dict(mod, false);
 }
  
 void
 rb_class_ivar_set_dict(VALUE mod, CFMutableDictionaryRef dict)
 {
-    if (rb_class_has_ivar_dict(mod)) {
-	CFMutableDictionaryRef old_dict = RCLASS_RUBY_IVAR_DICT(mod);
-	if (old_dict != dict) {
-	    if (old_dict != NULL) {
-		GC_RELEASE(old_dict);
-	    }
-	    GC_RETAIN(dict);
-	    RCLASS_RUBY_IVAR_DICT(mod) = dict;
-	}
-    }
-    else {
-	generic_ivar_dict_set(mod, dict);
-    }
+    generic_ivar_dict_set(mod, dict);
 }
 
 CFMutableDictionaryRef
@@ -1508,7 +1481,7 @@ retry:
 	}
 	tmp = RCLASS_SUPER(tmp);
     }
-    if (!exclude && !mod_retry && BUILTIN_TYPE(klass) == T_MODULE) {
+    if (!exclude && !mod_retry && RCLASS_MODULE(klass)) {
 	mod_retry = 1;
 	tmp = rb_cObject;
 	goto retry;
@@ -1713,7 +1686,7 @@ rb_const_defined_0(VALUE klass, ID id, int exclude, int recurse)
 	}
 	tmp = RCLASS_SUPER(tmp);
     }
-    if (!exclude && !mod_retry && BUILTIN_TYPE(klass) == T_MODULE) {
+    if (!exclude && !mod_retry && RCLASS_MODULE(klass)) {
 	mod_retry = 1;
 	tmp = rb_cObject;
 	goto retry;
@@ -1752,7 +1725,7 @@ mod_av_set(VALUE klass, ID id, VALUE val, int isconst)
 	rb_raise(rb_eSecurityError, "Insecure: can't set %s", dest);
     }
     if (OBJ_FROZEN(klass)) {
-	if (BUILTIN_TYPE(klass) == T_MODULE) {
+	if (TYPE(klass) == T_MODULE) {
 	    rb_error_frozen("module");
 	}
 	else {