From 6c68f1d7876e5e709bebf5441fbb9606efea4640 Mon Sep 17 00:00:00 2001
From: Desire NUENTSA <desire.nuentsa_wakam@inria.fr>
Date: Mon, 11 Mar 2013 19:21:18 +0100
Subject: [PATCH] bug #563 : Sparse block assignments should be called on
 compressed matrices. Uncompressed matrices will be supported later

---
 Eigen/src/SparseCore/SparseBlock.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Eigen/src/SparseCore/SparseBlock.h b/Eigen/src/SparseCore/SparseBlock.h
index f50fb66ea..36c281210 100644
--- a/Eigen/src/SparseCore/SparseBlock.h
+++ b/Eigen/src/SparseCore/SparseBlock.h
@@ -119,6 +119,7 @@ public:
     template<typename OtherDerived>
     inline BlockType& operator=(const SparseMatrixBase<OtherDerived>& other)
     {
+      eigen_assert(m_matrix.isCompressed() && " THE MATRIX SHOULD BE IN COMPRESSED MODE. PLEASE CALL makeCompressed()");
       typedef typename internal::remove_all<typename SparseMatrixType::Nested>::type _NestedMatrixType;
       _NestedMatrixType& matrix = const_cast<_NestedMatrixType&>(m_matrix);;
       // This assignement is slow if this vector set is not empty