[x11] Check pending release when mapping
Summary:
when unmap notify is followed by a map, the old Unmanaged will get released and never be managed again. by checking if there is a pending release operation, we can safely re-manage the window again.
BUG: 413350
Reviewers: KWin, zzag
Reviewed By: KWin, zzag
Subscribers: zzag, kwin, scao
Tags: KWin
Differential Revision: https://phabricator.kde.org/D24878