vm_eval.c: fix refined method when prepended

* vm_eval.c (vm_call0_body): refined module should not be skipped
  as prepended.  [ruby-core:78073] [Bug #12920]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56694 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_refinement.rb

@@ -1775,6 +1775,20 @@ class TestRefinement < Test::Unit::TestCase
                  eval_using(AliasInSubclass::M, "AliasInSubclass::D.new.bar"))
   end
 
+  def test_refine_with_prepend
+    assert_separately([], "#{<<-"begin;"}\n#{<<-"end;"}")
+    begin;
+      bug = '[ruby-core:78073] [Bug #12920]'
+      Integer.prepend(Module.new)
+      Module.new do
+        refine Integer do
+          define_method(:+) {}
+        end
+      end
+      assert_kind_of(Time, Time.now, bug)
+    end;
+  end
+
   private
 
   def eval_using(mod, s)

vm_eval.c

@@ -194,14 +194,19 @@ vm_call0_body(rb_thread_t* th, struct rb_calling_info *calling, const struct rb_
       case VM_METHOD_TYPE_REFINED:
 	{
 	    const rb_method_type_t type = cc->me->def->type;
-	    VALUE super_class;
+	    VALUE super_class = cc->me->defined_class;
 
-	    if (type == VM_METHOD_TYPE_REFINED && cc->me->def->body.refined.orig_me) {
-		cc->me = refined_method_callable_without_refinement(cc->me);
-		goto again;
+	    if (type == VM_METHOD_TYPE_REFINED) {
+		if (cc->me->def->body.refined.orig_me) {
+		    cc->me = refined_method_callable_without_refinement(cc->me);
+		    goto again;
+		}
+	    }
+	    else {
+		super_class = RCLASS_ORIGIN(super_class);
 	    }
 
-	    super_class = RCLASS_SUPER(RCLASS_ORIGIN(cc->me->defined_class));
+	    super_class = RCLASS_SUPER(super_class);
 
 	    if (!super_class || !(cc->me = rb_callable_method_entry(super_class, ci->mid))) {
 		enum method_missing_reason ex = (type == VM_METHOD_TYPE_ZSUPER) ? MISSING_SUPER : 0;