From a8cb0dfcf5957185815dbd4e74e8fdefb5a7fffd Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Fri, 14 Nov 2014 13:38:12 +0100
Subject: [PATCH] re-enable usage of ProductBase::m_result and workaround a
 compilation failure when m_result is too large but unused

---
 Eigen/src/Core/ProductBase.h | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/Eigen/src/Core/ProductBase.h b/Eigen/src/Core/ProductBase.h
index a494b5f87..1d9f7e929 100644
--- a/Eigen/src/Core/ProductBase.h
+++ b/Eigen/src/Core/ProductBase.h
@@ -85,7 +85,10 @@ class ProductBase : public MatrixBase<Derived>
 
   public:
 
-    typedef typename Base::PlainObject PlainObject;
+    typedef typename Base::PlainObject BasePlainObject;
+    typedef Matrix<Scalar,RowsAtCompileTime==1?1:Dynamic,ColsAtCompileTime==1?1:Dynamic,BasePlainObject::Options> DynPlainObject;
+    typedef typename internal::conditional<BasePlainObject::SizeAtCompileTime==Dynamic||BasePlainObject::SizeAtCompileTime*sizeof(Scalar) < EIGEN_STACK_ALLOCATION_LIMIT,
+                                           BasePlainObject, DynPlainObject>::type PlainObject;
 
     ProductBase(const Lhs& a_lhs, const Rhs& a_rhs)
       : m_lhs(a_lhs), m_rhs(a_rhs)
@@ -182,6 +185,11 @@ struct nested<GeneralProduct<Lhs,Rhs,Mode>, N, PlainObject>
 {
   typedef PlainObject const& type;
 };
+template<typename Lhs, typename Rhs, int Mode, int N, typename PlainObject>
+struct nested<const GeneralProduct<Lhs,Rhs,Mode>, N, PlainObject>
+{
+  typedef PlainObject const& type;
+};
 }
 
 template<typename NestedProduct>