bug#21895: [PATCH] shr: don't invoke unbound function (Bug#21895)

[martin rudalics]

> +(defun fringes-p ()
> +  "Return t if fringe-columns is bound, and either (fringe-columns 'left)
> or (fringe-columns 'right) returns nonzero."
> +  (and (fboundp 'fringe-columns)
> +       (or (not (zerop (fringe-columns 'right)))
> +           (not (zerop (fringe-columns 'left))))))
> +

This is wrong when ‘fringe-columns’ is unbound and a fringe is present.
The right solution is to

(require 'fringe)

in ‘shr-mode’ as you proposed earlier.

martin