only triggering topic infinite loader once a second, fixes #4477

public/src/client/topic/posts.js

@@ -181,10 +181,13 @@ define('forum/topic/posts', [
 	}
 
 	Posts.loadMorePosts = function(direction) {
-		if (!components.get('topic').length || navigator.scrollActive) {
+		if (!components.get('topic').length || navigator.scrollActive || Posts._infiniteScrollTimeout) {
 			return;
 		}
 
+		Posts._infiniteScrollTimeout = setTimeout(function() {
+			delete Posts._infiniteScrollTimeout;
+		}, 1000);
 		var replies = components.get('post').not('[data-index=0]').not('.new');
 		var afterEl = direction > 0 ? replies.last() : replies.first();
 		var after = parseInt(afterEl.attr('data-index'), 10) || 0;
@@ -204,7 +207,6 @@ define('forum/topic/posts', [
 			after: after,
 			direction: direction
 		}, function (data, done) {
-
 			indicatorEl.fadeOut();
 
 			if (data && data.posts && data.posts.length) {