fixed variable height filter drop items bug

lms/static/coffee/src/discussion/views/discussion_thread_list_view.coffee

@@ -204,7 +204,6 @@ class @DiscussionThreadListView extends Backbone.View
       return
     event.preventDefault()
 
-    itemHeight = $(".browse-topic-drop-menu a").outerHeight()
     items = $.makeArray($(".browse-topic-drop-menu-wrapper a").not(".hidden"))
     index = items.indexOf($('.browse-topic-drop-menu-wrapper .focused')[0])
 
@@ -216,11 +215,13 @@ class @DiscussionThreadListView extends Backbone.View
     $(".browse-topic-drop-menu-wrapper .focused").removeClass("focused")
     $(items[index]).addClass("focused")
 
-    scrollTarget = Math.min(index * itemHeight, $(".browse-topic-drop-menu").scrollTop())
-    scrollTarget = Math.max(index * itemHeight - $(".browse-topic-drop-menu").height() + itemHeight, scrollTarget)
+    itemTop = $(items[index]).parent().offset().top
+    scrollTop = $(".browse-topic-drop-menu").scrollTop()
+    itemFromTop = $(".browse-topic-drop-menu").offset().top - itemTop  
+    scrollTarget = Math.min(scrollTop - itemFromTop, scrollTop)
+    scrollTarget = Math.max(scrollTop - itemFromTop - $(".browse-topic-drop-menu").height() + $(items[index]).height(), scrollTarget)
     $(".browse-topic-drop-menu").scrollTop(scrollTarget)
 
 
 
 
-

lms/static/coffee/src/discussion/views/new_post_view.coffee

@@ -155,7 +155,6 @@ class @NewPostView extends Backbone.View
           return
         event.preventDefault()
 
-        itemHeight = $(".topic_menu_wrapper a").outerHeight()
         items = $.makeArray($(".topic_menu_wrapper a").not(".hidden"))
         index = items.indexOf($('.topic_menu_wrapper .focused')[0])
 
@@ -167,6 +166,9 @@ class @NewPostView extends Backbone.View
         $(".topic_menu_wrapper .focused").removeClass("focused")
         $(items[index]).addClass("focused")
 
-        scrollTarget = Math.min(index * itemHeight, $(".topic_menu").scrollTop())
-        scrollTarget = Math.max(index * itemHeight - $(".topic_menu").height() + itemHeight, scrollTarget)
+        itemTop = $(items[index]).parent().offset().top
+        scrollTop = $(".topic_menu").scrollTop()
+        itemFromTop = $(".topic_menu").offset().top - itemTop  
+        scrollTarget = Math.min(scrollTop - itemFromTop, scrollTop)
+        scrollTarget = Math.max(scrollTop - itemFromTop - $(".topic_menu").height() + $(items[index]).height() + 20, scrollTarget)
         $(".topic_menu").scrollTop(scrollTarget)

lms/static/sass/_discussion.scss

@@ -720,6 +720,10 @@ body.discussion {
         overflow-y: scroll;
       }
 
+      ul {
+        position: inline;
+      }
+
       > li:first-child a {
         border-top: none;
       }