Optimize support of scanners with different image sources or duplex unit
Summary:
BUG: 414600
The initial changeset of D24904 has been split into two seperate revisions.
This one addresses various bugs which may result in inconsistent scanner options.
Reviewers: sars, KDE Applications
Reviewed By: sars
Subscribers: aacid, ngraham
Differential Revision: https://phabricator.kde.org/D25052