bug#39662: 28.0.50; Emacs crashes in x_cr_define_fringe_bitmap if (fringe-mode 0)

[Dmitry Gutov]

On 18.02.2020 17:45, Robert Pluim wrote:
> Perhaps we should signal an error for this case
> and have diff-hl deal with the fallout? (define-fringe-bitmap
> docstring says the width has to be from 1-16).

Even if you simply signal an error (preferably readable one), it would 
already make the situation better.

diff-hl still wouldn't work with fringes disabled, but the users would 
more easily understand why that happens. I should add some some handling 
for that case as well, but that can come later.