add: if (!LocalFindProxyForURL) return null;  
context:     getProxyForURI: function(uri) {        // If we're not done loading the pac yet, wait (ideally). For        // now, just return DIRECT to avoid loops. A simple mutex        // between getProxyForURI and loadPACFromURI locks-up the        // browser.        if (!this.done)            return null;        // Call the original function-        return LocalFindProxyForURL(uri.spec, uri.host);    },
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/72d18273cacb273bb786efd9e0b243f55b107c8f/nsProxyAutoConfig.js/clean/netwerk/base/src/nsProxyAutoConfig.js