Missing virtual destructor in base classes

[Scott Wheeler]

> On Dec 4, 2018, at 08:11, Andy Champ <AChamp at roku.com> wrote:
> 
> Does anyone know why a simple fix on the lines of
> 
> ~classname() {}

Because adding virtual functions to base classes changes the size of the vtable for the class and thus breaks binary compatibility:

https://community.kde.org/Policies/Binary_Compatibility_Examples#Add_a_virtual_member_function_to_a_class_without_any

Changes like that can only be done in major (i.e. 2.0) releases.

-Scott