Redisplay loop with an unicode overlay-arrow-string

[Yuri D'Elia]

I'm disabling the left fringe to force using the overlay-arrow-string
(due to the fringe being unreadable on hidpi displays).

At some point I thought of being smart and attempt to:

  (setq overlay-arrow-string "🡆") ; RIGHTWARDS HEAVY ARROW

since it's an uncommon/heavy character (while still being narrower than
"=>"). Or just in case it's not readable for you, a more commonly
available character:

  (setq overlay-arrow-string "⮕") ; RIGHTWARDS BLACK ARROW

This results in an endless/unrecoverable redisplay loop on my current
config, hanging emacs.

To trigger on an emacs -q, evaluate this inside a buffer:

  (fringe-mode 0) ; force-disable the fringe
  (setq overlay-arrow-string "⮕")
  (setq overlay-arrow-position
        (set-marker (or overlay-arrow-position (make-marker))
                    (line-beginning-position)))