Fix shouldPreserveAddressOrderOnInsertions test

The test failed because the ArrayList - in contrast
to the underlying Set - did not check for duplicates
on insert. Under certain circumstances this lead to
an index out of bounds exception because the list in
the test contained duplicated entries which were not
present in the set of the Socks5Proxy.
I fixed the issue by only inserting the address when
it was not in the list before.

smack-extensions/src/test/java/org/jivesoftware/smackx/bytestreams/socks5/Socks5ProxyTest.java

@@ -30,6 +30,8 @@ import java.net.Socket;
 import java.net.SocketException;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
 import java.util.List;
 
 import org.jivesoftware.smack.util.StringUtils;
@@ -39,7 +41,7 @@ import org.junit.Test;
 
 /**
  * Test for Socks5Proxy class.
- * 
+ *
  * @author Henning Staib
  */
 public class Socks5ProxyTest {
@@ -73,7 +75,7 @@ public class Socks5ProxyTest {
 
     /**
      * The SOCKS5 proxy should use a free port above the one configured.
-     * 
+     *
      * @throws Exception should not happen
      */
     @Test
@@ -102,13 +104,11 @@ public class Socks5ProxyTest {
     @Test
     public void shouldPreserveAddressOrderOnInsertions() {
         Socks5Proxy proxy = Socks5Proxy.getSocks5Proxy();
-        List<String> addresses = new ArrayList<>(proxy.getLocalAddresses());
+
+        LinkedHashSet<String> addresses = new LinkedHashSet<>(proxy.getLocalAddresses());
 
         for (int i = 1 ; i <= 3; i++) {
-            String addr = Integer.toString(i);
+            addresses.add(Integer.toString(i));
-            if (!addresses.contains(addr)) {
-                addresses.add(addr);
-            }
         }
 
         for (String address : addresses) {
@@ -116,8 +116,10 @@ public class Socks5ProxyTest {
         }
 
         List<String> localAddresses = proxy.getLocalAddresses();
+
+        Iterator<String> iterator = addresses.iterator();
         for (int i = 0; i < addresses.size(); i++) {
-            assertEquals(addresses.get(i), localAddresses.get(i));
+            assertEquals(iterator.next(), localAddresses.get(i));
         }
     }
 
@@ -165,7 +167,7 @@ public class Socks5ProxyTest {
     /**
      * If the SOCKS5 proxy accepts a connection that is not a SOCKS5 connection it should close the
      * corresponding socket.
-     * 
+     *
      * @throws Exception should not happen
      */
     @Test
@@ -196,7 +198,7 @@ public class Socks5ProxyTest {
     /**
      * The SOCKS5 proxy should reply with an error message if no supported authentication methods
      * are given in the SOCKS5 request.
-     * 
+     *
      * @throws Exception should not happen
      */
     @Test
@@ -227,7 +229,7 @@ public class Socks5ProxyTest {
     /**
      * The SOCKS5 proxy should respond with an error message if the client is not allowed to connect
      * with the proxy.
-     * 
+     *
      * @throws Exception should not happen
      */
     @Test
@@ -249,7 +251,7 @@ public class Socks5ProxyTest {
 
         // send valid SOCKS5 message
         out.write(new byte[] { (byte) 0x05, (byte) 0x00, (byte) 0x00, (byte) 0x03, (byte) 0x01,
-                        (byte) 0xAA, (byte) 0x00, (byte) 0x00 });
+                (byte) 0xAA, (byte) 0x00, (byte) 0x00 });
 
         // verify error message
         assertEquals((byte) 0x05, (byte) in.read());
@@ -269,7 +271,7 @@ public class Socks5ProxyTest {
 
     /**
      * A Client should successfully establish a connection to the SOCKS5 proxy.
-     * 
+     *
      * @throws Exception should not happen
      */
     @Test
@@ -297,7 +299,7 @@ public class Socks5ProxyTest {
 
         // send valid SOCKS5 message
         out.write(new byte[] { (byte) 0x05, (byte) 0x00, (byte) 0x00, (byte) 0x03, (byte) 0x01,
-                        (byte) 0xAA, (byte) 0x00, (byte) 0x00 });
+                (byte) 0xAA, (byte) 0x00, (byte) 0x00 });
 
         // verify response
         assertEquals((byte) 0x05, (byte) in.read());