I changed the faces I know about. There are probably more faces which need the :extend attribute but this should be a good start.
Also, to eliminate the problem (and maybe other problems) in the future, I think it's recommended to set all faces to inherit from the original face and modify it from there, rather than redefining the face. Maybe that approach would also lead to unexpected problems?
Addresses #155
I changed the faces I know about. There are probably more faces which need the :extend attribute but this should be a good start.
Also, to eliminate the problem (and maybe other problems) in the future, I think it's recommended to set all faces to inherit from the original face and modify it from there, rather than redefining the face. Maybe that approach would also lead to unexpected problems?