Can you check whether window icons are still correct? See D14490

Does this compile? What compiler are you using? At least it does not on CI: https://build.kde.org/view/Failing/job/Plasma/job/plasma-workspace/

When calling a static method of a class using the "::", one rather needs to use the classname, not the name of an instance of the class. Or use a ".", but that blurs the fact it is a static method, so not recommended.

Please do a fix up :)

And attributes in general are better set before the application instance is created. Some attributes even need that, so defaulting to it is better,
Also, because someone might change code that is called before the place where the attribute is set, and if that is creating pixmaps already, they will miss out the flag and look broken.

Fixed in https://phabricator.kde.org/D23846