Fix #19 NullPointerException in TcpSyslogMessageSender#toString()

Author: Cyrille Le Clerc

src/main/java/com/cloudbees/syslog/sender/TcpSyslogMessageSender.java

@@ -206,6 +206,8 @@ public void setSyslogServerPort(int syslogServerPort) {
 
     @Nullable
     public String getSyslogServerHostname() {
+        if (syslogServerHostnameReference == null)
+            return null;
         InetAddress inetAddress = syslogServerHostnameReference.get();
         return inetAddress == null ? null : inetAddress.getHostName();
     }

src/test/java/com/cloudbees/syslog/sender/TcpSyslogMessageSenderTest.java

@@ -92,4 +92,12 @@ public void sendOverSSL() throws Exception {
     }
 
 
+    /**
+     * https://github.com/CloudBees-community/syslog-java-client/issues/19
+     */
+    @Test
+    public void test_bug19_NullPointerException_In_ToString(){
+        TcpSyslogMessageSender tcpSyslogMessageSender = new TcpSyslogMessageSender();
+        tcpSyslogMessageSender.toString();
+    }
 }