note 126558 added to function.ob-start

Be very careful when returning false from your callback function! Despite what the documentation says, this is *not* the same as returning the supplied $buffer value, unmodified. In the context of a 'clean' operation (e.g. ob_clean()) this will result in your callback function being disabled and skipped for any subsequent output. The answer is to ensure you always return a string value from your callback. This is likely a bug, and it may get fixed at some point, but it applies to all versions since PHP 5.4 up to the current version (8.1 at time of writing). Note that it was not an issue on PHP 5.3 and below. Some more detail can be seen on this Stack Overflow question: https://stackoverflow.com/questions/69845122/ A demonstration of the issue has been set up in this fiddle: https://3v4l.org/66cai ---- Server IP: 45.112.84.4 Probable Submitter: 45.112.85.242 (proxied: 212.69.47.82) ---- Manual Page -- https://php.net/manual/en/function.ob-start.php Edit -- https://main.php.net/note/edit/126558 Del: integrated -- https://main.php.net/note/delete/126558/integrated Del: useless -- https://main.php.net/note/delete/126558/useless Del: bad code -- https://main.php.net/note/delete/126558/bad+code Del: spam -- https://main.php.net/note/delete/126558/spam Del: non-english -- https://main.php.net/note/delete/126558/non-english Del: in docs -- https://main.php.net/note/delete/126558/in+docs Del: other reasons-- https://main.php.net/note/delete/126558 Reject -- https://main.php.net/note/reject/126558 Search -- https://main.php.net/manage/user-notes.php