[Klipper] Guard against broken data fetches
QMimeData::data() can fail. Fetching is done on demand. It's also possible for clients to advertise mimedata they don't really have.
This patch checks the read data before inserting into history.
QMimeData::data() can fail. Fetching is done on demand. It's also possible for clients to advertise mimedata they don't really have.
This patch checks the read data before inserting into history.