From 2baa298e391e8528cdcbd1d27c50342ed4b2432a Mon Sep 17 00:00:00 2001
From: Carlos Garnacho <carlosg@gnome.org>
Date: Fri, 22 Sep 2023 13:21:32 +0200
Subject: [PATCH] slider: Ignore left/right scroll directions

Both of these ended up with a "undefined" delta, which turned
the final value into 0 no matter the previous state.

While this was already fixed for touchpads in the previous commit
(by not forwarding emulated discrete events), this looks somewhat
out of place even for the mice that have left/right discrete scroll
actions (e.g. tilting the scroll wheel left or right).

Let these unhandled directions have a delta of 0, and focus on
vertical scroll for both smooth and discrete events.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2967>
---
 js/ui/slider.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/js/ui/slider.js b/js/ui/slider.js
index 0aea6d40d..111c48229 100644
--- a/js/ui/slider.js
+++ b/js/ui/slider.js
@@ -141,7 +141,7 @@ export const Slider = GObject.registerClass({
 
     scroll(event) {
         let direction = event.get_scroll_direction();
-        let delta;
+        let delta = 0;
 
         if (event.get_flags() & Clutter.EventFlags.FLAG_POINTER_EMULATED)
             return Clutter.EVENT_PROPAGATE;