From b56348046ffae0328314094686c79b5a5be45aa8 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Sun, 11 Aug 2013 17:52:43 +0200
Subject: [PATCH] Ref<> objects must be nested by reference because they
 potentially store a temporary object (transplanted from
 6719e56b5bfe9ae4badc9a6e894c5824f663d62e )

---
 Eigen/src/Core/Ref.h | 5 +++--
 test/ref.cpp         | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/Eigen/src/Core/Ref.h b/Eigen/src/Core/Ref.h
index aba795bdb..00d9e6d2b 100644
--- a/Eigen/src/Core/Ref.h
+++ b/Eigen/src/Core/Ref.h
@@ -94,7 +94,8 @@ struct traits<Ref<_PlainObjectType, _Options, _StrideType> >
   typedef _PlainObjectType PlainObjectType;
   typedef _StrideType StrideType;
   enum {
-    Options = _Options
+    Options = _Options,
+    Flags = traits<Map<_PlainObjectType, _Options, _StrideType> >::Flags | NestByRefBit
   };
 
   template<typename Derived> struct match {
@@ -111,7 +112,7 @@ struct traits<Ref<_PlainObjectType, _Options, _StrideType> >
     };
     typedef typename internal::conditional<MatchAtCompileTime,internal::true_type,internal::false_type>::type type;
   };
-
+  
 };
 
 template<typename Derived>
diff --git a/test/ref.cpp b/test/ref.cpp
index 65b4f5a3e..f639d900b 100644
--- a/test/ref.cpp
+++ b/test/ref.cpp
@@ -14,9 +14,9 @@
 
 static int nb_temporaries;
 
-inline void on_temporary_creation(int size) {
+inline void on_temporary_creation(int) {
   // here's a great place to set a breakpoint when debugging failures in this test!
-  if(size!=0) nb_temporaries++;
+  nb_temporaries++;
 }