From: Alexander Ebert <ebert@woltlab.com>
Date: Fri, 7 Aug 2020 14:52:41 +0000 (+0200)
Subject: Ignore certain scroll events that are just side effects
X-Git-Tag: 5.3.0_Alpha_1~68^2
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8797b34199979c1f1bebf5a63bf3b5737deeeedd;p=GitHub%2FWoltLab%2FWCF.git

Ignore certain scroll events that are just side effects
---

diff --git a/wcfsetup/install/files/js/WoltLabSuite/Core/Ui/Page/Action.js b/wcfsetup/install/files/js/WoltLabSuite/Core/Ui/Page/Action.js
index 429a28f212..db018aaa6c 100644
--- a/wcfsetup/install/files/js/WoltLabSuite/Core/Ui/Page/Action.js
+++ b/wcfsetup/install/files/js/WoltLabSuite/Core/Ui/Page/Action.js
@@ -72,7 +72,18 @@ define(['Dictionary', 'Language'], function (Dictionary, Language) {
 		 * @param {Event=} event
 		 */
 		_onScroll: function (event) {
+			if (document.documentElement.classList.contains('disableScrolling')) {
+				// Ignore any scroll events that take place while body scrolling is disabled,
+				// because it messes up the scroll offsets.
+				return;
+			}
+			
 			var offset = window.pageYOffset;
+			if (offset === _lastPosition) {
+				// Ignore any scroll event that is fired but without a position change. This can
+				// happen after closing a dialog that prevented the body from being scrolled.
+				return;
+			}
 			
 			if (offset >= 300) {
 				if (_toTopButton.classList.contains('initiallyHidden')) {