Release Date: June 16, 2022
4.2.1 release of CodeIgniter4
Guessing the file extension from the MIME type has been changed if the proposed extension is not valid. Previously, the guessing will early terminate and return
null. Now, if a proposed extension is given and is invalid, the MIME guessing will continue checking using the mapping of extension to MIME types.
If there is a cookie with a prefixed name and a cookie with the same name without a prefix, the previous
get_cookie()had the tricky behavior of returning the cookie without the prefix. Now the behavior has been fixed as a bug, and has been changed. See Upgrading for details.