[Ipopt] finalize solution

[Brad Bell]

Consider the case where the lower limit and upper limit is equal for one 
of the primal variable components; e.g.,
     x_l[j] = x_u[j]
in the get_bounds_info function.

I appears that in this case, finalize_solution will have
     z_L[j] = z_U[j] = 0.
Is this how Ipopt works ?

If so, consider the optimization problem
     minimize x[0]^2 subject to  1 <= x[0] <= 1
In this case, it appears to me, that the final multiplier z_L[0], in 
finalize_solution, should be non-zero.