On Oct 3, 2017 17:49, "Ola Nilsson" <ola.nilsson@gmail.com> wrote:

On Tue, Oct 3, 2017 at 3:08 PM, Robert Pluim <rpluim@gmail.com> wrote:
> Ola Nilsson <ola.nilsson@gmail.com> writes:
>
>>> does your problem go away?  If so, then it would be interesting how the
>>> values returned by xg_get_scale differ with gtk_widget_get_scale_factor
>>> and xg_get_gdk_scale called.
>>
>> Made no difference what I can see, except a lot of messages :
>>
>> (emacs:2302): Gtk-CRITICAL **: gtk_distribute_natural_allocation:
>> assertion 'extra_space >= 0' failed
>
> Through inspection I noticed we're not adjusting the width of the
> scrollbar for the scale. Does the following help?
>
> diff --git a/src/gtkutil.c b/src/gtkutil.c
> index 0da7039..60ba627 100644
> --- a/src/gtkutil.c
> +++ b/src/gtkutil.c
> @@ -3879,6 +3879,7 @@ xg_update_scrollbar_pos (struct frame *f,
>        top /= scale;
>        left /= scale;
>        height /= scale;
> +      width /= scale;
>        left -= (scale - 1) * ((width / scale) >> 1);
>
>        /* Clear out old position.  */

This works for me:

@@ -3883,7 +3883,7 @@ xg_update_scrollbar_pos (struct frame *f,
       top /= scale;
       left /= scale;
       height /= scale;
-      left -= (scale - 1) * ((width / scale) >> 1);
+      width /= scale;

       /* Clear out old position.  */
       int oldx = -1, oldy = -1, oldw, oldh;


I just realized that I never tested with scaling off.

/Ola Nilsson