[gnome-shell] appDisplay: Disable built-in mouse scrolling

[Marge Bot <marge-bot src gnome org>]

commit 543261e6eb64191abc5079b6a5bf6e757cdf9b22
Author: Florian Müllner <fmuellner gnome org>
Date:   Sat Jun 13 00:08:50 2020 +0200

    appDisplay: Disable built-in mouse scrolling
    
    We want to either handle a scroll event ourselves, or delegate it
    to the swipe tracker. What we never want is StScrollView's default
    handler that doesn't have any knowledge of pages, so disable it.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1560>

 js/ui/appDisplay.js | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index 58d1798025..4cfc13a7d1 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -151,6 +151,7 @@ var BaseAppView = GObject.registerClass({
             x_expand: true,
             y_expand: true,
             reactive: true,
+            enable_mouse_scrolling: false,
         });
         this._scrollView.set_policy(St.PolicyType.EXTERNAL, St.PolicyType.NEVER);