From ffc06bbaa3833837e68fa02b6089aab9c5bc35ee Mon Sep 17 00:00:00 2001
From: Elias Nahum <nahumhbl@gmail.com>
Date: Wed, 23 Mar 2022 12:56:50 -0300
Subject: [PATCH] Prevent more_messages to autoscroll more than once

---
 app/components/post_list/index.tsx                       | 4 ++--
 app/components/post_list/more_messages/more_messages.tsx | 9 ++++++---
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/app/components/post_list/index.tsx b/app/components/post_list/index.tsx
index a92a3d867f..46095bbe25 100644
--- a/app/components/post_list/index.tsx
+++ b/app/components/post_list/index.tsx
@@ -313,11 +313,11 @@ const PostList = ({
         );
     }, [currentTimezone, highlightPinnedOrSaved, isTimezoneEnabled, orderedPosts, shouldRenderReplyButton, theme]);
 
-    const scrollToIndex = useCallback((index: number, animated = true) => {
+    const scrollToIndex = useCallback((index: number, animated = true, applyOffset = true) => {
         listRef.current?.scrollToIndex({
             animated,
             index,
-            viewOffset: Platform.select({ios: -45, default: 0}),
+            viewOffset: applyOffset ? Platform.select({ios: -45, default: 0}) : 0,
             viewPosition: 1, // 0 is at bottom
         });
     }, []);
diff --git a/app/components/post_list/more_messages/more_messages.tsx b/app/components/post_list/more_messages/more_messages.tsx
index eca27f5f28..80f3c914fd 100644
--- a/app/components/post_list/more_messages/more_messages.tsx
+++ b/app/components/post_list/more_messages/more_messages.tsx
@@ -23,7 +23,7 @@ type Props = {
     posts: Array<string | PostModel>;
     registerScrollEndIndexListener: (fn: (endIndex: number) => void) => () => void;
     registerViewableItemsListener: (fn: (viewableItems: ViewToken[]) => void) => () => void;
-    scrollToIndex: (index: number, animated?: boolean) => void;
+    scrollToIndex: (index: number, animated?: boolean, applyOffset?: boolean) => void;
     unreadCount: number;
     theme: Theme;
     testID: string;
@@ -103,6 +103,7 @@ const MoreMessages = ({
     const serverUrl = useServerUrl();
     const pressed = useRef(false);
     const resetting = useRef(false);
+    const initialScroll = useRef(false);
     const [loading, setLoading] = useState(false);
     const [remaining, setRemaining] = useState(0);
     const underlayColor = useMemo(() => `hsl(${hexToHue(theme.buttonBg)}, 50%, 38%)`, [theme]);
@@ -149,13 +150,14 @@ const MoreMessages = ({
 
         const lastViewableIndex = viewableItems.filter((v) => v.isViewable)[viewableItems.length - 1]?.index || 0;
         const nextViewableIndex = lastViewableIndex + 1;
-        if (viewableItems[0].index === 0 && nextViewableIndex > newMessageLineIndex) {
+        if (viewableItems[0].index === 0 && nextViewableIndex > newMessageLineIndex && !initialScroll.current) {
             // Auto scroll if the first post is viewable and
             // * the new message line is viewable OR
             // * the new message line will be the first next viewable item
-            scrollToIndex(newMessageLineIndex, true);
+            scrollToIndex(newMessageLineIndex, true, false);
             resetCount();
             top.value = 0;
+            initialScroll.current = true;
             return;
         }
 
@@ -212,6 +214,7 @@ const MoreMessages = ({
 
     useEffect(() => {
         resetting.current = false;
+        initialScroll.current = false;
     }, [channelId]);
 
     return (