Piwik\Filechecks::isModifiedPathValid PHP Method

    private static function isModifiedPathValid($path)
    {
        if ($path === 'piwik.js') {
            // we could have used a postEvent hook to enrich "\Piwik\Manifest::$files;" which would also benefit plugins
            // that want to check for file integrity but we do not want to risk to break anything right now. It is not
            // as trivial because piwik.js might be already updated, or updated on the next request. We cannot define
            // 2 or 3 different filesizes and md5 hashes for one file so we check it here.
            if (Plugin\Manager::getInstance()->isPluginActivated('CustomPiwikJs')) {
                $trackerUpdater = new TrackerUpdater();
                if ($trackerUpdater->getCurrentTrackerFileContent() === $trackerUpdater->getUpdatedTrackerFileContent()) {
                    // file was already updated, eg manually or via custom piwik.js, this is a valid piwik.js file as
                    // it was enriched by tracker plugins
                    return true;
                }
                try {
                    // the piwik.js tracker file was not updated yet, but may be updated just after the update by
                    // one of the events CustomPiwikJs is listening to or by a scheduled task.
                    // In this case, we check whether such an update will succeed later and if it will, the file is
                    // valid as well as it will be updated on the next request
                    $trackerUpdater->checkWillSucceed();
                    return true;
                } catch (AccessDeniedException $e) {
                    return false;
                }
            }
        }
        return false;
    }