Wrong bahavior when multiple grid functions present.

The following code produces wrong results when showBug = True:

import numpy as np
from dune.grid import cartesianDomain, gridFunction, structuredGrid
from dune.alugrid import aluConformGrid

domain = cartesianDomain([0, 0], [1, 1], [3, 2])
view = aluConformGrid(domain)

showBug = True

if showBug:
    @gridFunction(view, order = 0, name = "x")
    def f(xglobal):
        x,y = xglobal
        return np.sin(20*x*y)*xglobal.two_norm
    F = [[f(corner) for corner in elt.geometry.corners] for elt in view.elements]

@gridFunction(view, order = 0, name = "x")
def h(xglobal):
    x,y = xglobal
    return xglobal[0]

L = [[h(corner) for corner in elt.geometry.corners] for elt in view.elements]
assert  abs(L[0][0] - 1./3.) < 1e-8