From 723a59ac26d28e42ad07221dc30b75ea8049ce1f Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Fri, 9 Jun 2017 12:54:40 +0200
Subject: [PATCH] add regression test for aliasing in product rewritting

---
 test/product.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/test/product.h b/test/product.h
index 3b6511270..0425a929e 100644
--- a/test/product.h
+++ b/test/product.h
@@ -216,6 +216,8 @@ template<typename MatrixType> void product(const MatrixType& m)
     // CwiseBinaryOp
     VERIFY_IS_APPROX(x = y + A*x, A*z);
     x = z;
+    VERIFY_IS_APPROX(x = y - A*x, A*(-z));
+    x = z;
     // CwiseUnaryOp
     VERIFY_IS_APPROX(x = Scalar(1.)*(A*x), A*z);
   }