Use scrollStop in chat (#5326)

public/src/modules/chat.js

@@ -8,8 +8,9 @@ define('chat', [
 	'sounds',
 	'forum/chats',
 	'forum/chats/messages',
-	'translator'
+	'translator',
-], function (components, taskbar, S, sounds, Chats, ChatsMessages, translator) {
+	'scrollStop'
+], function (components, taskbar, S, sounds, Chats, ChatsMessages, translator, scrollStop) {
 
 	var module = {};
 	var newMessage = false;
@@ -196,6 +197,8 @@ define('chat', [
 					handle: '.modal-header'
 				});
 			});
+			
+			scrollStop.apply(chatModal.find('[component="chat/messages"]'));
 
 			chatModal.find('#chat-close-btn').on('click', function () {
 				module.close(chatModal);

public/src/modules/scrollStop.js

@@ -21,7 +21,7 @@ define('scrollStop', function () {
 			
 			if (
 				(e.originalEvent.deltaY < 0 && scrollTop === 0) ||							// scroll up
-				(e.originalEvent.deltaY > 0 && (elementHeight + scrollTop) > scrollHeight)	// scroll down
+				(e.originalEvent.deltaY > 0 && (elementHeight + scrollTop) >= scrollHeight)	// scroll down
 			) {
 				return false;
 			}