Fixes incomplete promise when a child verticle could not be deployed … (#3186)

* Fixes incomplete promise when a child verticle could not be deployed because its parent has been undeployed

Signed-off-by: zenios <dimitris.zenios@gmail.com>

* Added tests

Signed-off-by: zenios <dimitris.zenios@gmail.com>

* Fail the promise after undeploy is completed

Signed-off-by: zenios <dimitris.zenios@gmail.com>

* Simplify test using onSuccess / onFailure

Signed-off-by: zenios <dimitris.zenios@gmail.com>

* Use await / testComplete instead of CountDownLatch

Signed-off-by: zenios <dimitris.zenios@gmail.com>

src/main/java/io/vertx/core/impl/DeploymentManager.java

@@ -463,7 +463,7 @@ public class DeploymentManager {
                   deployment.child = true;
                 } else {
                   // Orphan
-                  deployment.undeploy(null);
+                  deployment.undeploy(event -> promise.fail("Verticle deployment failed.Could not be added as child of parent verticle"));
                   return;
                 }
               }

src/test/java/io/vertx/core/DeploymentTest.java

@@ -1234,6 +1234,22 @@ public class DeploymentTest extends VertxTestBase {
     vertx = null;
   }
 
+  @Test
+  public void testDeployChildOnParentUndeploy() {
+    class ParentVerticle extends AbstractVerticle {
+      @Override
+      public void stop(Promise<Void> stopPromise) {
+        vertx.deployVerticle(ChildVerticle.class.getName())
+          .<Void>mapEmpty()
+          .setHandler(stopPromise);
+      }
+    }
+
+    vertx.deployVerticle(new ParentVerticle(), onSuccess(id ->
+      vertx.undeploy(id, onFailure(u -> testComplete()))));
+    await();
+  }
+
   @Test
   public void testUndeployAllFailureInUndeploy() throws Exception {
     int numVerticles = 10;