FrameSvg: make hasElementPrefix() also handle prefix with trailing -
Summary:
there are a few places which potentially pass a prefix with a trailing -,
e.g. if using directly the value of FrameSvg::prefix() or
FrameSvg::actualPrefix(). Support the assumption in such code, unbreaking
its currently not working behaviour.
Reviewers: Plasma, mart
Reviewed By: Plasma, mart
Subscribers: apol, kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D21174