fcbeebf6df unit test bug

Motivation:
fcbeebf6df introduced a unit test to verify ApplicationProtocolNegotiationHandler is compatible with SniHandler. However only the server attempts ALPN and verifies that it completes and the client doesn't verify the handshake is completed. This can lead to the client side SSL engine to prematurely close and throw an exception.

Modifications:
- The client should wait for the SSL handshake and ALPN to complete before the test exits.

Result:
SniHandlerTest.testSniWithApnHandler is more reliable.

handler/src/test/java/io/netty/handler/ssl/SniHandlerTest.java

@@ -22,6 +22,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.EventLoopGroup;
@@ -40,6 +41,7 @@ import java.net.InetSocketAddress;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 
+import javax.net.ssl.HandshakeCompletedEvent;
 import javax.xml.bind.DatatypeConverter;
 
 import static org.hamcrest.CoreMatchers.is;
@@ -165,7 +167,8 @@ public class SniHandlerTest {
         SslContext leanContext = makeSslContext();
         final SslContext clientContext = makeSslClientContext();
         SslContext wrappedLeanContext = null;
-        final CountDownLatch apnDoneLatch = new CountDownLatch(1);
+        final CountDownLatch serverApnDoneLatch = new CountDownLatch(1);
+        final CountDownLatch clientApnDoneLatch = new CountDownLatch(1);
 
         final DomainNameMapping<SslContext> mapping = new DomainMappingBuilder(nettyContext)
                                                          .add("*.netty.io", nettyContext)
@@ -191,11 +194,13 @@ public class SniHandlerTest {
                 @Override
                 protected void initChannel(Channel ch) throws Exception {
                     ChannelPipeline p = ch.pipeline();
+                    // Server side SNI.
                     p.addLast(new SniHandler(mapping));
+                    // Catch the notification event that APN has completed successfully.
                     p.addLast(new ApplicationProtocolNegotiationHandler("foo") {
                         @Override
                         protected void configurePipeline(ChannelHandlerContext ctx, String protocol) throws Exception {
-                            apnDoneLatch.countDown();
+                            serverApnDoneLatch.countDown();
                         }
                     });
                 }
@@ -207,10 +212,18 @@ public class SniHandlerTest {
             cb.handler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel ch) throws Exception {
-                    ChannelPipeline p = ch.pipeline();
+                    // Simulate client side SNI (which is currently not supported).
                     ch.write(Unpooled.wrappedBuffer(DatatypeConverter.parseHexBinary(tlsHandshakeMessageHex1)));
                     ch.writeAndFlush(Unpooled.wrappedBuffer(DatatypeConverter.parseHexBinary(tlsHandshakeMessageHex)));
+                    // Add a SslHandler so we can do the client side of the handshake.
                     ch.pipeline().addLast(clientContext.newHandler(ch.alloc()));
+                    // Catch the notification event that APN has completed successfully.
+                    ch.pipeline().addLast(new ApplicationProtocolNegotiationHandler("foo") {
+                        @Override
+                        protected void configurePipeline(ChannelHandlerContext ctx, String protocol) throws Exception {
+                            clientApnDoneLatch.countDown();
+                        }
+                    });
                 }
             });
 
@@ -220,7 +233,8 @@ public class SniHandlerTest {
             assertTrue(ccf.awaitUninterruptibly().isSuccess());
             clientChannel = ccf.channel();
 
-            assertTrue(apnDoneLatch.await(5, TimeUnit.SECONDS));
+            assertTrue(serverApnDoneLatch.await(5, TimeUnit.SECONDS));
+            assertTrue(clientApnDoneLatch.await(5, TimeUnit.SECONDS));
         } finally {
             if (serverChannel != null) {
                 serverChannel.close().sync();