Fix W3 Total Cache W3_Plugin_TotalCache::ob_callback() expected to be a reference

Around a year ago I was playing with W3 Total Cache plugin on while I got an annoying warning

Warning: Parameter 1 to W3_Plugin_TotalCache::ob_callback() expected to be a reference, value given in /wp-includes/functions.php on line 3269

The funny part is that one of the functions was passing by reference which I still could not find the reason for it, maybe it was a limitation in PHP 4.3. Removing one character “&” fixed the issue so I submitted a pull request to the author although the repository currently does not accept pull . Later on as PHP 7.0 was released, the issue started to on PHP as well which brought more attention to this small fix. The included anger such as @kmob2 who said

this is becoming a running gag

Even more user @pratham2003 proposed a one line to solve the

sed -i.bak 's/ ob_callback(&/ ob_callback(/g' /path/to/public_html/wp-content//w3-total-cache/lib/W3/Plugin/TotalCache.php

I hope that the developers will finally listen to the users and fix it soon!