From 33abe75afab26216a299977a3133f05441d997eb Mon Sep 17 00:00:00 2001
From: Hauke Heibel <hauke.heibel@gmail.com>
Date: Thu, 28 Jan 2010 10:32:44 +0100
Subject: [PATCH] Fixed Quaternion operator*= added regression test.

---
 Eigen/src/Geometry/Quaternion.h | 3 ++-
 test/geo_quaternion.cpp         | 3 +++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/Eigen/src/Geometry/Quaternion.h b/Eigen/src/Geometry/Quaternion.h
index b8b41ebcf..285a93c15 100644
--- a/Eigen/src/Geometry/Quaternion.h
+++ b/Eigen/src/Geometry/Quaternion.h
@@ -377,7 +377,8 @@ template <class Derived>
 template <class OtherDerived>
 EIGEN_STRONG_INLINE Derived& QuaternionBase<Derived>::operator*= (const QuaternionBase<OtherDerived>& other)
 {
-  return (derived() = derived() * other.derived());
+  derived() = derived() * other.derived();
+  return derived();
 }
 
 /** Rotation of a vector by a quaternion.
diff --git a/test/geo_quaternion.cpp b/test/geo_quaternion.cpp
index 052c01fbf..311ffd2ec 100644
--- a/test/geo_quaternion.cpp
+++ b/test/geo_quaternion.cpp
@@ -59,6 +59,9 @@ template<typename Scalar> void quaternion(void)
   q1.coeffs().setRandom();
   VERIFY_IS_APPROX(q1.coeffs(), (q1*q2).coeffs());
 
+  // concatenation
+  q1 *= q2;
+
   q1 = AngleAxisx(a, v0.normalized());
   q2 = AngleAxisx(a, v1.normalized());