php/php-src — pull request #18 by nikic (2012-03-23 21:11:33+00:00)
Title: Allow resetting the error handler

This allows the error handler to be reset using set_error_handler(null). As the code suggests this behavior was already previously intended, but the callback check was done too strictly.

See also bug https://bugs.php.net/bug.php?id=60738.

PS: I replaced the `!zend_is_true` with a strict null check to be consistent with the behavior of `set_exception_handler`.