Currently, the iconloader adds an icon to the cache whenever it hits an error page and it also adds a null icon to the cache for every page that doesn't have a favicon. This makes sure to add an icon to the cache only when actual data exists.
Created attachment 15165 [details] Fix for this bug
Comment on attachment 15165 [details] Fix for this bug Ok, this looks good, but i strongly suspect this will cause a perf regression. I suspect we cache null favicons to prevent us repeatedly trying to fetch a favicon from servers that don't have one.
Comment on attachment 15165 [details] Fix for this bug We track these icons to avoid redundant network requests, which hurt performance.
This behavior is intentional. We track pages that don't have icons to prevent pinging the page for its icon every time. There's expiration-date behavior here so we would re-request the icon once a day or once a week (I forget which), and we also re-request the icon if the user manually reloads the page. Closing as invalid...