Return valid string value for DescriptionRole in all models
Summary:
A qml binding converting an empty QVariant to a string value will result
in a warning:
Unable to assign [undefined] to QString
Which is apparently happening to this bug reporter, but not for other
roles.
Grepping all models shows 2 code paths where this could happen.
BUG: 369783
Test Plan:
Kickoff/Kicker still open
Couldn't reproduce the original bug.
Reviewers: Plasma, hein
Reviewed By: Plasma, hein
Subscribers: hein, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D4033