mart added a comment.
in void AbstractClient::addRepaintDuringGeometryUpdates() the first time a window moves, that's when the bug occurs, i get a smaller geometry. that's a debug of the values m_visibleRectBeforeGeometryUpdate and deco_rect QRect(274,423 1062x552) QRect(256,410 1092x582) QRect(256,410 1092x582) QRect(255,410 1092x582) QRect(255,410 1092x582) QRect(251,409 1092x582) QRect(251,409 1092x582) QRect(248,409 1092x582) that suggests the first time the shadow was *not* taken into account REPOSITORY R108 KWin REVISION DETAIL https://phabricator.kde.org/D4989 To: mart, #plasma, graesslin Cc: anthonyfieroni, plasma-devel, kwin, #kwin, progwolff, lesliezhai, ali-mohamed, jensreuterberg, abetts, sebas, apol
