Only restrict obstacles for dofs that have an obstacle

dune/solvers/transferoperators/mandelobsrestrictor.cc

@@ -30,6 +30,9 @@ restrict(const std::vector<BoxConstraint<typename DiscFuncType::field_type,block
     // Loop over all coarse grid dofs
     for (size_t i=0; i<transferMat.N(); i++) {
         
+        if (fHasObstacle[i].none())
+            continue;
+
         const RowType& row = transferMat[i];
         
         ColumnIterator cIt    = row.begin();
@@ -37,6 +40,9 @@ restrict(const std::vector<BoxConstraint<typename DiscFuncType::field_type,block
         
         // Loop over all fine grid base functions in the support of tObsIt
         for(; cIt!=cEndIt; ++cIt) {
+
+            if (tHasObstacle[cIt.index()].none())
+                continue;
             
             // Sort out spurious entries due to numerical dirt
             if ((*cIt)[0][0] < 1e-3)