Node:clipping -> Clipping to RenderTexture crash

[minggo]

Step to reproduce the issue:

• run test-cpp
• enter Node:clipping -> Clipping To RenderTexture
• will crash sometimes on iOS and will 100% crash on Android

The problem is in this code

auto button = MenuItemFont::create("Reproduce bug", [&](Ref *sender) {
        enumerateChildren("remove me [0-9]", [&](Node *node) {
            this->removeChild(node);
            this->reproduceBug();
            return false;
        }
                          );
    });

Invoke removeChild() and addChild()(invoked in reproduceBug()) in the callback of enumerateChildren(). Because enumerateChildren() will iterate children, so it is not safe to remove or add a child.

@ricardoquesada
I found you added the test case, and i don't know why you do it like this.
Any idea?

[ricardoquesada]

You are correct. The test case will crash because of the removeChild().
I can't remember why I added that code.
I won't be able to fix now, but feel free to comment the removeChild() out and add a comment saying why you commented out that line. thanks.

[minggo]

And it will invoke addChild() in this->reproduceBug();.
Can i comment it as removeChild()?

[minggo]

May be i know why you need to invoke removeChild(). Because reproduceBug() will add a container, if clicked Reproduce bug may times, the performance will be slow.

[minggo]

So may be you should not use Node::enumerateChildren to remove a child, should use tag to add/remove a child here.

[minggo]

@ricardoquesada
If you are agree with it.
I will modify it as i mentioned above.

[WenhaiLin]

Fixed at #8824