It won't throw an error, per se. Underscores in classnames are perfectly fine.
But the default autoloader will try to find the class hybrid_auth
on your include_path
in the file hybrid/auth.php
.
You can either:
Do a manual include before referencing the class so that autoloading doesn't kick in
Write a custom autoloader for this class - and any others like it - and push that autoloader onto the Zend_Loader_Autoloader
stack.
Rename the class and/or filename to be PSR-0-compliant so the standard autoloader is happy with it.
Personally, I'd go with (2): write your own autoloader. I hate to monkey-patch 3rd-party library code because subsequent lib updates overwrite my hack.
For writing your own autoloaders, take a look at this.