Dear distributions,
unfortunately I have to inform you that Qt 5.9 includes a change [1]
which causes a severe regression in KWin/X11 (Wayland is not affected).
The regression results in keyboard input not working in effects like
Present Windows. It affects any KWin version.
We have created a workaround for Plasma 5.10.3 [2]. In case you are
already shipping Qt 5.9 together with Plasma 5.10 I advise to
cherry-pick this commit.
Please note that the change will not be backported to neither Plasma 5.9
(as there are no more releases planed) nor to Plasma 5.8 LTS. The change
does not fit the nature of an LTS release as it is a workaround for a
future software. I highly advise against updating Qt on systems running
Plasma LTS. Please note that I consider it as likely that we have other
areas in Plasma affected by the Qt change and we just haven't identified
them. If you combine Plasma 5.8/5.9 with Qt 5.9 I advise to cherry-pick
the commit.
Best Regards
Martin Flöser
KWin maintainer
[1]
https://code.qt.io/cgit/qt/qtbase.git/commit/?h=5.9&id=2b34aefcf02f09253473b096eb4faffd3e62b5f4
[2] a6dee74ee455d1da47dd5c9d55a84adbb5e1426a
