Added check on whether point is within bounds in GridVessel

src/gridtools/GridVessel.cpp

@@ -139,6 +139,7 @@ void GridVessel::getIndices( const std::vector<double>& point, std::vector<unsig
   for(unsigned i=0;i<dimension;++i){
       indices[i]=std::floor( (point[i] - min[i])/dx[i] );
       if( pbc[i] ) indices[i]=indices[i]%nbin[i];
+      else if( indices[i]>nbin[i] ) plumed_merror("point is outside grid range");
   }
 }