barf broken; getting }{ / ][ / )(.

[gilch]

Barf gets the brackets backwards if the result is empty. Example:

; '|' is cursor
(1 2 3 [|] 4 5 6)
; C-0 s
(1 2 3 [|  4] 5 6)
; C-0 b
(1 2 3 ]|[ 4 5 6)
; this is no longer valid structure.

What probably should have happened:

(1 2 3 [|] 4 5 6)

Similarly, {}, #{}, and () become }{, }#{, and )(, respectively.
Backwards barf has exactly the same problem.

[laurentpetit]

@thickey do you feel like you could take a look at it?