Boundary conditions that are not actual boundary conditions(!) are not respected during adaptivity

[Marie Rognes]

Only constraints on degrees of freedom associated with facets that are actually exterior facets seem to be preserved during the auto-adaptive cycle. For instance, take a look at the resulting solutions from:

from dolfin import *

mesh = UnitSquare(4, 4)

V = FunctionSpace(mesh, "CG", 1)
u = TrialFunction(V)
v = TestFunction(V)
a = inner(grad(u), grad(v))*dx
f = Expression("sin(pi*x[0])")
L = f*v*dx

bc = DirichletBC(V, 0.0, "x[0] <= 0.5")

u = Function(V)
M = u*dx
eps = 1e-3
solve(a == L, u, bc, eps, M)

plot(u.coarse())
plot(u.fine())
interactive()