From f96842021649f2a21304fec9e16b687b88c7c433 Mon Sep 17 00:00:00 2001
From: Alexander Skvortsov <38059171+askvortsov1@users.noreply.github.com>
Date: Mon, 30 Nov 2020 14:01:08 -0500
Subject: [PATCH] Don't use browser scroll restore in DiscussionPage (#2476)

Although native browser scroll restorations have become quite powerful, it interferes with Flarum's PostStream, so if we're on a DiscussionPage, we use manual scroll restoration.
---
 js/src/common/components/Page.js          | 11 +++++++++++
 js/src/forum/components/DiscussionPage.js |  2 ++
 2 files changed, 13 insertions(+)

diff --git a/js/src/common/components/Page.js b/js/src/common/components/Page.js
index 0d0a4afd88..4db613649c 100644
--- a/js/src/common/components/Page.js
+++ b/js/src/common/components/Page.js
@@ -29,6 +29,13 @@ export default class Page extends Component {
      * @type {Boolean}
      */
     this.scrollTopOnCreate = true;
+
+    /**
+     * Whether the browser should restore scroll state on refreshes.
+     *
+     * @type {Boolean}
+     */
+    this.useBrowserScrollRestoration = true;
   }
 
   oncreate(vnode) {
@@ -41,6 +48,10 @@ export default class Page extends Component {
     if (this.scrollTopOnCreate) {
       $(window).scrollTop(0);
     }
+
+    if ('scrollRestoration' in history) {
+      history.scrollRestoration = this.useBrowserScrollRestoration ? 'auto' : 'manual';
+    }
   }
 
   onremove() {
diff --git a/js/src/forum/components/DiscussionPage.js b/js/src/forum/components/DiscussionPage.js
index c5812bf397..beb0b2a5d8 100644
--- a/js/src/forum/components/DiscussionPage.js
+++ b/js/src/forum/components/DiscussionPage.js
@@ -18,6 +18,8 @@ export default class DiscussionPage extends Page {
   oninit(vnode) {
     super.oninit(vnode);
 
+    this.useBrowserScrollRestoration = false;
+
     /**
      * The discussion that is being viewed.
      *