From 7d78c9a6a491b17d879400fe79fb6c0d75a1add8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B6ren=20Weber?= <mail@soeren-weber.de>
Date: Sun, 26 Jan 2025 14:13:55 +0100
Subject: [PATCH] scroll: fix high cpu usage #996

---
 layouts/partials/version.txt |  2 +-
 static/js/theme.js           | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/layouts/partials/version.txt b/layouts/partials/version.txt
index 0162ff1111..a26cdea556 100644
--- a/layouts/partials/version.txt
+++ b/layouts/partials/version.txt
@@ -1 +1 @@
-7.3.1+4f182a115b0a3a6d4b6b2ba46abe3c4e71cfda5c
\ No newline at end of file
+7.3.1+c4a8c278be4013f283872b4cbb88e4baa19b2988
\ No newline at end of file
diff --git a/static/js/theme.js b/static/js/theme.js
index e3eb06d132..130d0c6af6 100644
--- a/static/js/theme.js
+++ b/static/js/theme.js
@@ -62,6 +62,17 @@ function adjustContentWidth() {
   elc.style[dir_padding_end] = '' + end + 'px';
 }
 
+function throttle(func, limit) {
+  let inThrottle;
+  return function (...args) {
+    if (!inThrottle) {
+      func.apply(this, args);
+      inThrottle = true;
+      setTimeout(() => (inThrottle = false), limit);
+    }
+  };
+}
+
 function fixCodeTabs() {
   /* if only a single code block is contained in the tab and no style was selected, treat it like style=code */
   var codeTabContents = Array.from(document.querySelectorAll('.tab-content.tab-panel-style')).filter(function (tabContent) {
@@ -1311,7 +1322,8 @@ function initScrollPositionSaver() {
   elc.addEventListener('scroll', function (event) {
     if (!ticking) {
       window.requestAnimationFrame(function () {
-        savePosition();
+        // #996 GC is so damn slow that we need further throttling
+        throttle(savePosition, 250);
         ticking = false;
       });
       ticking = true;