fixed user link and back button

lms/static/coffee/src/discussion/content.coffee

@@ -47,6 +47,7 @@ if Backbone?
 
     initialize: ->
       DiscussionUtil.addContent @id, @
+      @set 'user_url', DiscussionUtil.urlFor('user_profile', @get('user_id'))
       @resetComments(@get('children'))
       
 

lms/static/coffee/src/discussion/utils.coffee

@@ -64,21 +64,25 @@ class @DiscussionUtil
       openclose_thread        : "/courses/#{$$course_id}/discussion/threads/#{param}/close"
       permanent_link_thread   : "/courses/#{$$course_id}/discussion/forum/#{param}/threads/#{param1}"
       permanent_link_comment  : "/courses/#{$$course_id}/discussion/forum/#{param}/threads/#{param1}##{param2}"
+      user_profile            : "/courses/#{$$course_id}/discussion/forum/users/#{param}"
     }[name]
 
   @safeAjax: (params) ->
     $elem = params.$elem
-    if $elem.attr("disabled")
+    if $elem and $elem.attr("disabled")
       return
+    params["url"] = URI(params["url"]).addSearch ajax: 1
     params["beforeSend"] = ->
-      $elem.attr("disabled", "disabled")
+      if $elem
+        $elem.attr("disabled", "disabled")
       if params["$loading"]
         if params["loadingCallback"]?
           params["loadingCallback"].apply(params["$loading"])
         else
           params["$loading"].loading()
     $.ajax(params).always ->
-      $elem.removeAttr("disabled")
+      if $elem
+        $elem.removeAttr("disabled")
       if params["$loading"]
         if params["loadedCallback"]?
           params["loadedCallback"].apply(params["$loading"])

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

@@ -29,10 +29,12 @@ class @DiscussionThreadView extends Backbone.View
     MathJax.Hub.Queue ["Typeset", MathJax.Hub, element.attr("id")]
 
   renderResponses: ->
-    $.ajax @model.id, success: (data, textStatus, xhr) =>
-      @$(".loading").remove()
-      comments = new Comments(data['content']['children'])
-      comments.each @renderResponse
+    DiscussionUtil.safeAjax
+      url: @model.id
+      success: (data, textStatus, xhr) =>
+        @$(".loading").remove()
+        comments = new Comments(data['content']['children'])
+        comments.each @renderResponse
 
   renderResponse: (response) =>
       view = new ThreadResponseView(model: response)