mat+=selfadjoint_view problem for sparse matrices

Submitted by Yixuan Qiu

Assigned to Nobody

Link to original bugzilla bug (#1358)
Version: 3.3 (current stable)

Description

This is basically the same problem as in bug #1343 (closed) (http://eigen.tuxfamily.org/bz/show_bug.cgi?id=1343), but for sparse matrices.

A minimal example:

=====================================================================

#include <Eigen/SparseCore>

typedef Eigen::SparseMatrix<double> SpMat;

int main()
{
SpMat m1(10, 10);

SpMat m2 = m1.selfadjointView<Eigen::Lower>(); // Fine  
SpMat m3(10, 10);  
m3 += m1.selfadjointView<Eigen::Lower>();      // Fails on 3.3  
  
return 0;  

}

=====================================================================

OS: Fedora 25 64-bit
Compiler: GCC 6.2/clang 3.8

Thank you.

Best,
Yixuan