do the right thing if the number of patches given is lower than the number of grid levels

[[Imported from SVN: r4867]]

dune/fufem/boundarypatchprolongator.hh

@@ -65,7 +65,7 @@ public:
 
         const GridType& grid = patches[0]->gridView().grid();
 
-        int maxLevel = patches.size()-1;
+        int maxLevel = std::min((size_t)grid.maxLevel(), patches.size()-1);
         // Set array sizes correctly
         for (int i=1; i<=maxLevel; i++)
             patches[i]->setup(grid.levelView(i));