Need to put the return clause in the synchronized block, in SSLContextImpl.getSuportedCipherSuiteList() and SSLContextImpl.getDefaultCipherSuiteList():

    // Get suported CipherSuiteList.
    CipherSuiteList getSuportedCipherSuiteList() {
        // The maintenance of cipher suites needs to be synchronized.
        synchronized (this) {
            // Clear cache of available ciphersuites.
            clearAvailableCache();

            if (supportedCipherSuiteList == null) {
                supportedCipherSuiteList = getApplicableCipherSuiteList(
                        getSuportedProtocolList(), false);
            }

+           return supportedCipherSuiteList;
        }
-       return supportedCipherSuiteList;
    }

Similar update to SSLContextImpl.getDefaultCipherSuiteList.