Broadcasting with view() doesn't work as expected

[tomchor]

Setting Field values using broacasting seems to fail silently when using view(). For example in the MWE below, I'm creating two 2D fields and I'm trying to set the first row of E using the last row of U:

using Oceananigans
grid = RectilinearGrid(topology = (Bounded, Bounded, Flat), size = (3, 3), extent = (1, 1))

U = XFaceField(grid)
set!(U, reshape(1:(grid.Nx+1)*grid.Ny, (:, grid.Ny)))

E = XFaceField(grid)

view(E, 1, :, :) .= view(U, grid.Nx+1, :, :)

However, when I check if what I just set is true I get:

view(E, 1, :, :) == view(U, grid.Nx + 1, :, :) = false

What did happen apparently is that the first row E got assigned the values from the first row of U:

view(E, 1, :, :) == view(U, 1, :, :) = true

Am I missing something here? This works exactly as expected when using interior:

julia> interior(E, 1, :, :) .= interior(U, grid.Nx+1, :, :)
3×1 view(::Array{Float64, 3}, 4, 4:6, 1:1) with eltype Float64:
  4.0
  8.0
 12.0

julia> @show view(E, 1, :, :) == view(U, grid.Nx+1, :, :)
view(E, 1, :, :) == view(U, grid.Nx + 1, :, :) = true
true

julia> @show view(E, 1, :, :) == view(U, 1, :, :)
view(E, 1, :, :) == view(U, 1, :, :) = false
false

But using interior prevents me from using halo indices, so ideally I'd use another method for that.

[glwagner]

This is probably an issue with indexing for windowed fields if I had to guess