bug #478: fix regression in the eigen decomposition of zero matrices.

1 files changed, 9 insertions, 0 deletions

diff --git a/test/eigensolver_selfadjoint.cpp b/test/eigensolver_selfadjoint.cpp
index 4ed126116..39ad4130e 100644
--- a/test/eigensolver_selfadjoint.cpp
+++ b/test/eigensolver_selfadjoint.cpp
@@ -180,6 +180,15 @@ template<typename MatrixType> void selfadjointeigensolver(const MatrixType& m)
     SelfAdjointEigenSolver<MatrixType> eig(a.adjoint() * a);
     eig.compute(a.adjoint() * a);
   }
+
+  // regression test for bug 478
+  {
+    a.setZero();
+    SelfAdjointEigenSolver<MatrixType> ei3(a);
+    VERIFY_IS_EQUAL(ei3.info(), Success);
+    VERIFY_IS_MUCH_SMALLER_THAN(ei3.eigenvalues().norm(),RealScalar(1));
+    VERIFY((ei3.eigenvectors().transpose()*ei3.eigenvectors().transpose()).eval().isIdentity());
+  }
 }
 
 template<int>