VclPtr<VirtualDevice> attribute in the OutputDevice class

Hello everybody,


In the /core/include/vcl/outdev.hxx file, at line 331 we can see the 
attribute mpAlphaVDev which is of type VclPtr<VirtualDevice>. And the 
comment at line 330 is "TEMP TEMP TEMP".

Does someone know what this attribute is for?

Using opengrok, when I search for mpAlphaVDev 
(https://opengrok.libreoffice.org/s?refs=mpAlphaVDev&project=core), I 
see that the pointer is created when the OutputDevice is a VirtualDevice 
(in /core/vcl/source/gdi/virdev.cxx at line 367), and I couldn't find 
any other line where mpAlphaVDev is instanciated.

Can someone confirm this? If that is true, at least the attribute should 
be moved in the VirtualDevice class. But I can't understand the reason 
to be of this attribute. Should not it be purely and simply removed?


Best regards,

Adrien Ollier