VM: Evaluate-in-frame should happen in the scope of the method class, not the receiver class.

runtime/vm/debugger.cc

Index: runtime/vm/debugger.cc
diff --git a/runtime/vm/debugger.cc b/runtime/vm/debugger.cc
index b30a33142820226ed76e0c6c3a60d554a9c90760..66ae53aceb16b150d4c6857ec9f9173da0b91b40 100644
--- a/runtime/vm/debugger.cc
+++ b/runtime/vm/debugger.cc
@@ -1071,12 +1071,14 @@ RawObject* ActivationFrame::Evaluate(const String& expr) {
                         Array::Handle(Array::MakeArray(param_values)));
   } else {
     const Object& receiver = Object::Handle(GetReceiver());
+    const Class& method_cls = Class::Handle(function().Owner());

[hausner, 2016/04/04 19:52:32]

I think this should be the method's origin(), not Owner(). For a function that
is from a mixin class, you want the class where the function is defined, not the
class to which the function is "mixed in". The difference is noticeable when you
refer to static members or the library of the mixin class.

Your test should cover that aspect as well, ideally.

[rmacnak, 2016/04/04 22:07:26]

Good catch.
Added.

     ASSERT(receiver.IsInstance() || receiver.IsNull());
     if (!(receiver.IsInstance() || receiver.IsNull())) {
       return Object::null();
     }
     const Instance& inst = Instance::Cast(receiver);
-    return inst.Evaluate(expr,
+    return inst.Evaluate(method_cls,
+                         expr,
                          Array::Handle(Array::MakeArray(param_names)),
                          Array::Handle(Array::MakeArray(param_values)));
   }