fixes #813

app/logical/session_loader.rb

@@ -25,6 +25,7 @@ class SessionLoader
 
     update_last_logged_in_at
     set_time_zone
+    store_favorite_tags_in_cookies
     set_statement_timeout
   end
 
@@ -81,6 +82,12 @@ private
     cookies[:password_hash] && cookies.signed[:user_name] && User.authenticate_cookie_hash(cookies.signed[:user_name], cookies[:password_hash])
   end
 
+  def store_favorite_tags_in_cookies
+    if cookies[:favorite_tags].blank? && CurrentUser.user.favorite_tags.present?
+      cookies[:favorite_tags] = Tag.categories_for(CurrentUser.user.favorite_tags.scan(/\S+/)).to_a.flatten.join(" ")
+    end
+  end
+
   def update_last_logged_in_at
     return if CurrentUser.is_anonymous?
     return if CurrentUser.last_logged_in_at && CurrentUser.last_logged_in_at > 1.week.ago