From 38825e5fbe0e1716da8aeea5c1a430f7970a5317 Mon Sep 17 00:00:00 2001
From: Stefano <stefano.dafarra@gmail.com>
Date: Tue, 12 Jun 2018 18:06:39 +0200
Subject: [PATCH] Fixed bug when the matrix to update has not changed.

Somehow, when the scaling was set to zero, it was segfaulting.
---
 include/OsqpEigen/Solver.tpp | 20 ++++++++++++--------
 tests/UpdateMatricesTest.cpp |  1 +
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/include/OsqpEigen/Solver.tpp b/include/OsqpEigen/Solver.tpp
index 0a4fb66..94590a8 100644
--- a/include/OsqpEigen/Solver.tpp
+++ b/include/OsqpEigen/Solver.tpp
@@ -134,10 +134,12 @@ bool OsqpEigen::Solver::updateHessianMatrix(const Eigen::SparseMatrix<T> &hessia
 
     if(evaluateNewValues(m_oldHessianTriplet,  m_newUpperTriangularHessianTriplets,
                          m_hessianNewIndices, m_hessianNewValues)){
-        if(osqp_update_P(m_workspace, m_hessianNewValues.data(), m_hessianNewIndices.data(), m_hessianNewIndices.size()) != 0){
-            std::cerr << "[OsqpEigen::Solver::updateHessianMatrix] Unable to update hessian matrix."
-                      << std::endl;
-            return false;
+        if (m_hessianNewValues.size() > 0) {
+            if(osqp_update_P(m_workspace, m_hessianNewValues.data(), m_hessianNewIndices.data(), m_hessianNewIndices.size()) != 0){
+                std::cerr << "[OsqpEigen::Solver::updateHessianMatrix] Unable to update hessian matrix."
+                          << std::endl;
+                return false;
+            }
         }
     }
     else{
@@ -228,10 +230,12 @@ bool OsqpEigen::Solver::updateLinearConstraintsMatrix(const Eigen::SparseMatrix<
 
     if(evaluateNewValues(m_oldLinearConstraintsTriplet, m_newLinearConstraintsTriplet,
                          m_constraintsNewIndices, m_constraintsNewValues)){
-        if(osqp_update_A(m_workspace, m_constraintsNewValues.data(), m_constraintsNewIndices.data(), m_constraintsNewIndices.size()) != 0){
-            std::cerr << "[OsqpEigen::Solver::updateLinearConstraintsMatrix] Unable to update linear constraints matrix."
-                      << std::endl;
-            return false;
+        if (m_constraintsNewValues.size() > 0) {
+            if(osqp_update_A(m_workspace, m_constraintsNewValues.data(), m_constraintsNewIndices.data(), m_constraintsNewIndices.size()) != 0){
+                std::cerr << "[OsqpEigen::Solver::updateLinearConstraintsMatrix] Unable to update linear constraints matrix."
+                          << std::endl;
+                return false;
+            }
         }
     }
     else{
diff --git a/tests/UpdateMatricesTest.cpp b/tests/UpdateMatricesTest.cpp
index b788672..e2b1ead 100644
--- a/tests/UpdateMatricesTest.cpp
+++ b/tests/UpdateMatricesTest.cpp
@@ -50,6 +50,7 @@ TEST(QPProblem, FirstRun)
 
     solver.data()->setNumberOfVariables(2);
     solver.data()->setNumberOfConstraints(3);
+    solver.settings()->setScaling(0);
     ASSERT_TRUE(solver.data()->setHessianMatrix(H_s));
     ASSERT_TRUE(solver.data()->setGradient(gradient));
     ASSERT_TRUE(solver.data()->setLinearConstraintsMatrix(A_s));