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

[Thibault Polge]

Thanks for the quick response!

> Perhaps we should signal an error for this case and have diff-hl deal
> with the fallout?

IMHO the issue is at least partially with emacs, not diff-hl (I just
didn't have time to dig further), so signaling seems more reasonable
than postponing the crash.

(Also I should have specified that this may be a regression: I cannot
reproduce in 26.3.)

Regards,
Thibault