In the exact same file setRect() is called with explicit parameters (0.0f, 0.0f, 0.0f, 0.0f)

https://github.com/folecr/cocos2d-x/blob/7d3df00d241cf6fca0c1382f1ce080522a70dbf4/cocos2dx/cocoa/CCGeometry.cpp#L115