keep better track of per-user ip addrs

app/logical/session_loader.rb

@@ -26,6 +26,7 @@ class SessionLoader
     end
 
     update_last_logged_in_at
+    update_last_ip_addr
     set_time_zone
     store_favorite_tags_in_cookies
     set_statement_timeout
@@ -108,6 +109,12 @@ private
     refresh_listbooru
   end
 
+  def update_last_ip_addr
+    return if CurrentUser.is_anonymous?
+    return if CurrentUser.user.last_ip_addr == @request.remote_ip
+    CurrentUser.user.update_attribute(:last_ip_addr, @request.remote_ip)
+  end
+
   def refresh_listbooru
     if CurrentUser.is_gold? && CurrentUser.has_saved_searches? && Danbooru.config.listbooru_server && CurrentUser.is_gold?
       SavedSearch.refresh_listbooru(CurrentUser.id)