Comment 2 for bug 888720

Going through my reported bugs I found this, and it is still there with a slightly different message. Heres a working reproduction:

from dolfin import *
mesh = UnitSquareMesh(10,10)
x, y = mesh.ufl_cell().x
print assemble(1.0/(y+1)*dx, mesh=mesh) # works
print assemble((y+1)**-1*dx, mesh=mesh) # triggers assertion

now gives

...
  File "/home/martinal/opt/fenics/dorsal-unstable/lib/python2.7/site-packages/ffc/quadrature/quadraturerepresentation.py", line 193, in _tabulate_basis
    (points, weights) = create_quadrature(cell_domain, degree, rule)
  File "/home/martinal/opt/fenics/dorsal-unstable/lib/python2.7/site-packages/ffc/quadrature_schemes.py", line 70, in create_quadrature
    return _triangle_scheme(degree)
  File "/home/martinal/opt/fenics/dorsal-unstable/lib/python2.7/site-packages/ffc/quadrature_schemes.py", line 160, in _triangle_scheme
    x, w = _fiat_scheme("triangle", degree)
  File "/home/martinal/opt/fenics/dorsal-unstable/lib/python2.7/site-packages/ffc/quadrature_schemes.py", line 85, in _fiat_scheme
    return fiat_create_quadrature(shape, num_points_per_axis)
  File "/home/martinal/opt/fenics/dorsal-unstable/lib/python2.7/site-packages/ffc/fiatinterface.py", line 145, in create_quadrature
    quad_rule = FIAT.make_quadrature(reference_cell(shape), num_points)
  File "/home/martinal/opt/fenics/dorsal-unstable/lib/python2.7/site-packages/FIAT/quadrature.py", line 169, in make_quadrature
    assert (m > 0), msg
AssertionError: Expecting at least one (not 0) quadrature point per direction