version: cocos2d-x-3.0beta2

file: CCPhysicsWorld.cpp

In the function PhysicsWorld::collisionBeginCallback
Line 265
There is the following if statement

if ((shapeA->getCategoryBitmask() & shapeB->getContactTestBitmask()) == 0
|| (shapeB->getContactTestBitmask() & shapeA->getCategoryBitmask()) == 0)

shapeB is never having its CategoryBitMask compared to shapeA's contact test mask.

The correct check should be this

if ((shapeA->getCategoryBitmask() & shapeB->getContactTestBitmask()) == 0
|| (shapeB->getCategoryBitmask() & shapeA->getContactTestBitmask()) == 0)