Merge pull request #6162 from dumganhar/pull/6160

Fixed a potential crash in EventDispatcher, based on PR #6160

cocos/2d/CCEventDispatcher.cpp

@@ -340,6 +340,27 @@ void EventDispatcher::removeEventListenersForTarget(Node* target, bool recursive
         }
     }
     
+    // Bug fix: ensure there are no references to the node in the list of listeners to be added.
+    // If we find any listeners associated with the destroyed node in this list then remove them.
+    // This is to catch the scenario where the node gets destroyed before it's listener
+    // is added into the event dispatcher fully. This could happen if a node registers a listener
+    // and gets destroyed while we are dispatching an event (touch etc.)
+    for (auto iter = _toAddedListeners.begin(); iter != _toAddedListeners.end(); )
+    {
+        EventListener * listener = *iter;
+            
+        if (listener->getSceneGraphPriority() == target)
+        {
+            listener->setRegistered(false);
+            listener->release();
+            iter = _toAddedListeners.erase(iter);
+        }
+        else
+        {
+            ++iter;
+        }
+    }
+    
     if (recursive)
     {
         const auto& children = target->getChildren();

tests/cpp-tests/Classes/NewEventDispatcherTest/NewEventDispatcherTest.cpp

@@ -8,6 +8,7 @@
 
 #include "NewEventDispatcherTest.h"
 #include "testResource.h"
+#include "CCAutoreleasePool.h"
 
 namespace {
     
@@ -27,7 +28,8 @@ std::function<Layer*()> createFunctions[] =
     CL(PauseResumeTargetTest),
     CL(Issue4129),
     CL(Issue4160),
-    CL(DanglingNodePointersTest)
+    CL(DanglingNodePointersTest),
+    CL(RegisterAndUnregisterWhileEventHanldingTest)
 };
 
 unsigned int TEST_CASE_COUNT = sizeof(createFunctions) / sizeof(createFunctions[0]);
@@ -1413,3 +1415,44 @@ std::string DanglingNodePointersTest::subtitle() const
             "CC_NODE_DEBUG_VERIFY_EVENT_LISTENERS == 1\n&& COCOS2D_DEBUG > 0";
 #endif
 }
+
+
+RegisterAndUnregisterWhileEventHanldingTest::RegisterAndUnregisterWhileEventHanldingTest()
+{
+    Point origin = Director::getInstance()->getVisibleOrigin();
+    Size size = Director::getInstance()->getVisibleSize();
+    
+    auto callback1 = [=](DanglingNodePointersTestSprite * sprite)
+    {
+        auto callback2 = [](DanglingNodePointersTestSprite * sprite)
+        {
+            CCASSERT(false, "This should never get called!");
+        };
+        
+        {
+            AutoreleasePool pool;
+            
+            auto sprite2 = DanglingNodePointersTestSprite::create(callback2);
+            sprite2->setTexture("Images/CyanSquare.png");
+            sprite2->setPosition(origin+Point(size.width/2, size.height/2));
+            
+            addChild(sprite2, 0);
+            removeChild(sprite2);
+        }
+    };
+    
+    auto sprite1 = DanglingNodePointersTestSprite::create(callback1);
+    sprite1->setTexture("Images/CyanSquare.png");
+    sprite1->setPosition(origin+Point(size.width/2, size.height/2));
+    addChild(sprite1, -10);
+}
+
+std::string RegisterAndUnregisterWhileEventHanldingTest::title() const
+{
+    return "RegisterAndUnregisterWhileEventHanldingTest";
+}
+
+std::string RegisterAndUnregisterWhileEventHanldingTest::subtitle() const
+{
+    return  "Tap the square multiple times - should not crash!";
+}

tests/cpp-tests/Classes/NewEventDispatcherTest/NewEventDispatcherTest.h

@@ -217,4 +217,14 @@ public:
     virtual std::string subtitle() const override;
 };
 
+class RegisterAndUnregisterWhileEventHanldingTest : public EventDispatcherTestDemo
+{
+public:
+    CREATE_FUNC(RegisterAndUnregisterWhileEventHanldingTest);
+    RegisterAndUnregisterWhileEventHanldingTest();
+    
+    virtual std::string title() const override;
+    virtual std::string subtitle() const override;
+};
+
 #endif /* defined(__samples__NewEventDispatcherTest__) */