Summary of Changes

ob_end_clean raises a notice if the included layout file did something stupid (like running ob_get_clean() !!!)

Notice: ob_end_clean(): failed to delete buffer. No buffer to delete in
/home/path/public_html/libraries/src/Layout/FileLayout.php

Battle tested code should check if a buffer exists before attempting to clear it, if by blindly clearing a non-existent buffer then raises a PHP Notice/Error/Warning/Fatal.

Testing Instructions

Install JEvents 3.6.12 on Joomla 4 beta 6

Visit https://example.com/administrator/index.php?option=com_jevents&task=params.edit

note that the file administrator/components/com_jevents/layouts/joomla/system/message.php is included by include $path; and message.php runs a ob_get_clean() within in.

This is probably a bug in JEvents because the ob_get_clean should be two lines higher so it doesn't get run in Joomla 4 - but still Joomla should handle cleaning of output buffers better and never show Notices to the screen.

Actual result BEFORE applying this Pull Request

Notice: ob_end_clean(): failed to delete buffer. No buffer to delete in
/home/path/public_html/libraries/src/Layout/FileLayout.php

Expected result AFTER applying this Pull Request

No errors

Documentation Changes Required

// @GeraintEdwards