From 3bf92d1a47e28766a40834f575ebe05487962c56 Mon Sep 17 00:00:00 2001
From: dellaert <dellaert@cc.gatech.edu>
Date: Mon, 24 Nov 2014 09:58:47 +0100
Subject: [PATCH] Force eval

---
 gtsam_unstable/nonlinear/Expression-inl.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gtsam_unstable/nonlinear/Expression-inl.h b/gtsam_unstable/nonlinear/Expression-inl.h
index a98ab349f..1a855aeb7 100644
--- a/gtsam_unstable/nonlinear/Expression-inl.h
+++ b/gtsam_unstable/nonlinear/Expression-inl.h
@@ -507,7 +507,7 @@ struct GenerateFunctionalNode: Argument<T, A, Base::N + 1>, Base {
     void reverseAD(const Eigen::Matrix<double, Rows, Cols> & dFdT,
         JacobianMap& jacobians) const {
       Base::Record::reverseAD(dFdT, jacobians);
-      This::trace.reverseAD(dFdT * This::dTdA, jacobians);
+      This::trace.reverseAD((dFdT * This::dTdA).eval(), jacobians);
     }
   };