bug #1310: workaround a compilation regression from 3.2 regarding triangular * homogeneous

2 files changed, 14 insertions, 0 deletions

diff --git a/Eigen/src/Geometry/Homogeneous.h b/Eigen/src/Geometry/Homogeneous.h
index 4e2213b33..a23068c8d 100644
--- a/Eigen/src/Geometry/Homogeneous.h
+++ b/Eigen/src/Geometry/Homogeneous.h
@@ -402,6 +402,18 @@ struct generic_product_impl<Lhs, Homogeneous<RhsArg,Vertical>, DenseShape, Homog
   }
 };
 
+// TODO: the following specialization is to address a regression from 3.2 to 3.3
+// In the future, this path should be optimized.
+template<typename Lhs, typename RhsArg, int ProductTag>
+struct generic_product_impl<Lhs, Homogeneous<RhsArg,Vertical>, TriangularShape, HomogeneousShape, ProductTag>
+{
+  template<typename Dest>
+  static void evalTo(Dest& dst, const Lhs& lhs, const Homogeneous<RhsArg,Vertical>& rhs)
+  {
+    dst.noalias() = lhs * rhs.eval();
+  }
+};
+
 template<typename Lhs,typename Rhs>
 struct homogeneous_left_product_refactoring_helper
 {
diff --git a/test/geo_homogeneous.cpp b/test/geo_homogeneous.cpp
index 305794cdf..2187c7bf9 100644
--- a/test/geo_homogeneous.cpp
+++ b/test/geo_homogeneous.cpp
@@ -111,6 +111,8 @@ template<typename Scalar,int Size> void homogeneous(void)
   
   VERIFY_IS_APPROX( (v0.transpose().homogeneous() .lazyProduct( t2 )).hnormalized(), (v0.transpose().homogeneous()*t2).hnormalized() );
   VERIFY_IS_APPROX( (pts.transpose().rowwise().homogeneous() .lazyProduct( t2 )).rowwise().hnormalized(), (pts1.transpose()*t2).rowwise().hnormalized() );
+
+  VERIFY_IS_APPROX( (t2.template triangularView<Lower>() * v0.homogeneous()).eval(), (t2.template triangularView<Lower>()*hv0) );
 }
 
 void test_geo_homogeneous()