Support archive installs with adoption commands
Summary:
This previously caused any icon pack installed through the store to
not function when the adoption command pointed at a directory rather
than a file.
BUG:407687
Test Plan:
Previously: Using the "Use" option in either the Icons KCM or Discover with any icon pack would cause there to be no icon theme set
With patch: Correctly switches to the newly installed icon set
Reviewers: Frameworks, Plasma, KNewStuff, apol, ngraham
Reviewed By: apol
Subscribers: kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D25824