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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 HHVM 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. on line 3269

The funny part is that one of the functions was passing by reference which I still could not find the reason it, maybe it was a limitation in PHP 4.3. one character “&” fixed the issue so I submitted a pull request to the author although the repository currently does not accept pull request. 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 command 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!