commit 476beed7f837cbed9abc401f685c1882936fa959
author Gael Guennebaud <g.gael@free.fr> Mon Jun 22 16:51:45 2015 +0200
committer Gael Guennebaud <g.gael@free.fr> Mon Jun 22 16:51:45 2015 +0200
tree c313b87935c46d5130708b6168a98d16fc633f8b
parent 9fc1c921377df09684cf3184daf527009276f78a

bug #1017: apply Christoph's patch preventing underflows in makeHouseholder

Eigen/src/Householder/Householder.h

diff --git a/Eigen/src/Householder/Householder.h b/Eigen/src/Householder/Householder.h
index 32112af..4c1f499 100644
--- a/Eigen/src/Householder/Householder.h
+++ b/Eigen/src/Householder/Householder.h
@@ -75,8 +75,9 @@
   
   RealScalar tailSqNorm = size()==1 ? RealScalar(0) : tail.squaredNorm();
   Scalar c0 = coeff(0);
+  const RealScalar tol = (std::numeric_limits<RealScalar>::min)();
 
-  if(tailSqNorm == RealScalar(0) && numext::imag(c0)==RealScalar(0))
+  if(tailSqNorm <= tol && numext::abs2(numext::imag(c0))<=tol)
   {
     tau = RealScalar(0);
     beta = numext::real(c0);