bug#29627: 25.3; x-show-tip does not display text when x-gtk-use-tooltips is nil and left/right-margin-width is set

[Eli Zaretskii]

> From: Terje Larsen <terlar@gmail.com>
> Date: Sat, 09 Dec 2017 13:54:24 +0000
> 
> When you have enabled `left-margin-width' and `right-margin-width'
> as well as disabled the `x-gtk-use-system-tooltips', the text will
> be invisible when running `x-show-tip'. The tip will be show, but
> not visible.
> 
> Steps to reproduce with emacs -Q
> (setq-default
>   left-margin-width 1
>   right-margin-width 1)
> 
> (setq x-gtk-use-system-tooltips nil)
> 
> (x-show-tip "Can you see me now?")

Thanks, fixed on the emacs-26 branch.