At least TagCurrentChanged can be triggered with a nullptr tag. That
means the current tag is reset to "none". We should thus handle nullptr
in all receivers of beginTagChange and endTagChange.
Change-Id: Ife558beca9fb1ed5ab246b76bbaab19c1c227e8a
Reviewed-by: Marco Benelli <marco.benelli@qt.io>
Reviewed-by: Tomasz Olszak <olszak.tomasz@gmail.com>
QtCreator used to crash when copy or cut button were pressed without
having selected an item.
Task-number: QTCREATORBUG-17637
Change-Id: Iceaea7a9f826ed16c4caee9fc28b4c14eb304c62
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>
