[kenjis]

Thank you for you explanation.

i am specially saying for IE browser, I had faced strange issue with CI cart item update on IE browser, the cart items was not being update on page load, when i reload page by "ctrl+f5" then cart items was updating.

I google issue, and found IE browser cached response header, see these links
https://msdn.microsoft.com/en-us/library/bb250442.aspx
https://support.microsoft.com/en-us/kb/234067/en-us
The issue resolved when i added cache control header in repose.

PHP Code:

  $this->output->set_header("Cache-Control: no-store, no-cache, must-revalidate, no-transform, max-age=0, post-check=0, pre-check=0");
  $this->output->set_header("Pragma: no-cache");