Hi @timmillwood Thanks for this PR. I'm ok with adding the _, though this is also solvable by using the whitelist property from within your own ruleset.

The build won't pass though until the unit test on line 46 has also been fixed. Changing that function call to pfpro_init() should do it.

For the record:
I've verified that all of the original functions of the extension have a _ in them.
The extension can't be found in the manual anymore, but luckily there is the wayback machine:
https://web.archive.org/web/20070226211109/http://www.php.net/manual/en/ref.pfpro.php

Thanks @jrfnl. We have whitelisted the code for now, but would be good for this false positive to be fixed.

Updated the test.

@timmillwood Thanks for updating the PR. I'm sorry though, I wasn't explicit enough. The actual error message is also being tested, so this means that the test data provider also needs to be updated.