UnitRange{Rational} misbehaves

[simonster]

julia> rg = 1//2:3
1//2:3//1

julia> length(rg)
ERROR: InexactError()
 in call at base.jl:38
 in length at range.jl:191

julia> for x in rg println(x) end
1//2
3//2
5//2
7//2
9//2
11//2
... (does not end)

I guess this should work if we adjust the endpoint on construction?