This is one half of SRC-252, which is really two issues filed as one.

To reproduce, set -Dhttp.proxyHost and -Dhttp.proxyPort in RC 0.9.2. Your proxy.pac file will be malformed, containing an else clause but no if statement:

function FindProxyForURL(url, host) {
        return 'PROXY localhost:4444; PROXY localhost:3128';
    } else {
        return 'PROXY localhost:3128';
}