Add a minor sanity assert in row_nonzero_inds.

src/faust_linear_operator/CPU/faust_MatSparse.hpp

@@ -1070,10 +1070,13 @@ template<typename FPP>
 std::vector<int> Faust::MatSparse<FPP, Cpu>::col_nonzero_inds(faust_unsigned_int col_id) const
 {
 	std::vector<int> ids;
+	// if col_id isn't in good range it does nothing (harmless)
 	for (int i=0; i < mat.outerSize(); i++)
 		for (typename Eigen::SparseMatrix<FPP,Eigen::RowMajor>::InnerIterator it(mat,i); it; ++it)
 			if(it.col() == col_id)
+			{
 				ids.push_back(it.row());
+			}
 	return ids;
 }
 
@@ -1081,8 +1084,11 @@ template<typename FPP>
 std::vector<int> Faust::MatSparse<FPP, Cpu>::row_nonzero_inds(faust_unsigned_int row_id) const
 {
 	std::vector<int> ids;
+	assert(row_id >= 0 && row_id < this->dim1);
 	for (typename Eigen::SparseMatrix<FPP,Eigen::RowMajor>::InnerIterator it(mat,row_id); it; ++it)
+	{
 		ids.push_back(it.col());
+	}
 	return ids;
 }