function domain is not correct after changing mesh coordinates

I am trying to solve a free boundary problem. To do so I want to adjust the mesh coordinates to represent the domain as it changes. The following code illustrates a problem that I am having though. I define a dolfin Function (I call it "u") on a FunctionSpace with domain [0,1] then change the mesh coordinates so I think that the domain will become [0,2]. But when I try to evaluate my Function at 1, I get an error message saying "The point is not inside the domain."

------------------- python code -------------------

from dolfin import *
from numpy import linspace

mesh = IntervalMesh(10, 0.0, 1.0)
V = FunctionSpace(mesh, 'Lagrange', 1)
u = interpolate(Expression('x[0]'), V)

print 'u(0.5) = ', u(0.5)
print 'u(1.0) = ', u(1.0)

mesh.coordinates()[:,0] = linspace(0.0, 2.0, 11)

print 'u(0.5) = ', u(0.5)
print 'u(1.0) = ', u(1.0)

------------------- output -------------------

u(0.5) = 0.5
u(1.0) = 1.0
u(0.5) = 0.25
u(1.0) = Evaluating at x = <Point x = 1 y = 0 z = 0>

Traceback (most recent call last):
  File "trash.py", line 14, in <module>
    print 'u(1.0) = ', u(1.0)
  File "/usr/lib/python2.7/dist-packages/dolfin/functions/function.py", line 378, in __call__
    self.eval(values, x)
RuntimeError:

*** -------------------------------------------------------------------------
*** DOLFIN encountered an error. If you are not able to resolve this issue
*** using the information listed below, you can ask for help at
***
*** https://answers.launchpad.net/dolfin
***
*** Remember to include the error message listed below and, if possible,
*** include a *minimal* running example to reproduce the error.
***
*** -------------------------------------------------------------------------
*** Error: Unable to evaluate function at point.
*** Reason: The point is not inside the domain. Consider setting "allow_extrapolation" to allow extrapolation.
*** Where: This error was encountered inside Function.cpp.
*** Process: 0
*** -------------------------------------------------------------------------

------------------- end of output -------------------

If I include the statement

parameters['allow_extrapolation'] = True

as suggested by the error message the program works (with a warning message) but it seems like this should not be necsessary; the point (x=1) is inside the domain.

------------------- output after setting 'allow_extrapolation' = True -------------------

u(0.5) = 0.5
u(1.0) = 1.0
u(0.5) = 0.25
u(1.0) = Extrapolating function value at x = <Point x = 1 y = 0 z = 0> (not inside domain).
 0.5

------------------- end of output -------------------

Is this a bug in FEniCS/DOLFIN or am I doing something wrong?