Bug 850922 - Don't put NULL getterobj/setterobj in the reloctable store buffers; r=billm

--HG--
extra : rebase_source : 21ac1e5d6cba8a0771c9612c304ff4206a29f902

js/src/vm/Shape-inl.h

@@ -106,15 +106,17 @@ BaseShape::operator=(const BaseShape &other)
         getterObj = other.getterObj;
         GetterSetterWriteBarrierPost(runtime(), &getterObj);
     } else {
+        if (rawGetter)
+            GetterSetterWriteBarrierPostRemove(runtime(), &getterObj);
         rawGetter = other.rawGetter;
-        GetterSetterWriteBarrierPostRemove(runtime(), &getterObj);
     }
     if (flags & HAS_SETTER_OBJECT) {
         setterObj = other.setterObj;
         GetterSetterWriteBarrierPost(runtime(), &setterObj);
     } else {
+        if (rawSetter)
+            GetterSetterWriteBarrierPostRemove(runtime(), &setterObj);
         rawSetter = other.rawSetter;
-        GetterSetterWriteBarrierPostRemove(runtime(), &setterObj);
     }
     compartment_ = other.compartment_;
     return *this;