Fix for AsyncHttpClient#45 [websocket] NPE when connection fail to connect

Author: jfarcand

src/main/java/com/ning/http/client/websocket/WebSocketUpgradeHandler.java

@@ -106,7 +106,7 @@ public final void onSuccess(WebSocket webSocket) {
     @Override
     public final void onFailure(Throwable t) {
         for (WebSocketListener w : l) {
-            if (!ok.get()) {
+            if (!ok.get() && webSocket != null) {
                 webSocket.addMessageListener(w);
             }
             w.onError(t);

src/test/java/com/ning/http/client/websocket/TextMessageTest.java

@@ -22,6 +22,8 @@
 import java.util.concurrent.atomic.AtomicReference;
 
 import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+import static org.testng.Assert.fail;
 
 public abstract class TextMessageTest extends AbstractBasicTest {
 
@@ -100,6 +102,36 @@ public void onError(Throwable t) {
         assertEquals(text.get(), "OnOpen");
     }
 
+    @Test(timeOut = 60000)
+    public void onEmptyListenerTest() throws Throwable {
+        AsyncHttpClient c = getAsyncHttpClient(new AsyncHttpClientConfig.Builder().build());
+
+        WebSocket websocket = null;
+        try {
+            websocket = c.prepareGet(getTargetUrl())
+                    .execute(new WebSocketUpgradeHandler.Builder().build()).get();
+        } catch (Throwable t) {
+            fail();
+        }
+        assertTrue(websocket != null);
+    }
+
+    @Test(timeOut = 60000)
+    public void onFailureTest() throws Throwable {
+        AsyncHttpClient c = getAsyncHttpClient(new AsyncHttpClientConfig.Builder().build());
+        final AtomicReference<String> text = new AtomicReference<String>("");
+
+        WebSocket websocket = null;
+        Throwable t = null;
+        try {
+            websocket = c.prepareGet("ws://abcdefg")
+                    .execute(new WebSocketUpgradeHandler.Builder().build()).get();
+        } catch (Throwable t2) {
+            t = t2;
+        }
+        assertTrue(t != null);
+    }
+
     @Test(timeOut = 60000)
     public void onTimeoutCloseTest() throws Throwable {
         AsyncHttpClient c = getAsyncHttpClient(new AsyncHttpClientConfig.Builder().build());