Nasty bug/fail in Zend_View_Abstract

gistfile1.php

<?php 
    /**
     * Clear all assigned variables
     *
     * Clears all variables assigned to Zend_View either via {@link assign()} or
     * property overloading ({@link __set()}).
     *
     * @return void
     */
    public function clearVars()
    {
        $vars   = get_object_vars($this);
        foreach ($vars as $key => $value) {
            if ('_' != substr($key, 0, 1)) {
                unset($this->$key);
            }
        }
    }

This was a necessary hack in ZF1. Since the coding standards used underscores to indicate non-public visibility, the way to play nice when extending it is to keep non-public members underscore-prefixed.

There's really no clean way to fix this, as the variables are members of the view object itself. We fixed it in ZF2... but only by making architectural changes.