D15072: [server] Abort drag start on correct conditions and without posting error

[Roman Gilg]

romangg edited the test plan for this revision.

REPOSITORY
  R127 KWayland

REVISION DETAIL
  https://phabricator.kde.org/D15072

To: romangg, #kwin
Cc: kde-frameworks-devel, michaelh, ngraham, bruns