old_olution created from dereferences shared_ptr

src/amdis/ProblemInstat.hpp

@@ -66,7 +66,7 @@ namespace AMDiS
     auto oldSolution(TreePath path = {}) const
     {
       auto&& tp = makeTreePath(path);
-      return makeDiscreteFunction(oldSolutionVector(), tp);
+      return makeDiscreteFunction(*oldSolutionVector(), tp);
     }
 
     /// Implementation of \ref ProblemTimeInterface::transferInitialSolution().