https://bugs.kde.org/show_bug.cgi?id=377901
--- Comment #9 from Martin Gräßlin <mgraess...@kde.org> --- Some additional investigation results: both moving windows and Alt+Tab require a keyboard/pointer grab. The xTime() is going into those requests and the documentation says: "The request fails with status InvalidTime if the specified time is earlier than the last-pointer-grab time or later than the current server time. Otherwise, the last-pointer-grab time is set to the specified time, with CurrentTime replaced by the current server time." If we don't update the xTime any more due to overflow we are in the situation that our specified time is "later than current server time". On the other hand if we pass the new wrapped around number we fall into the condition that "specified time is earlier than the last-pointer-grab time". To illustrate: let's assume the last-pointer-grab time is 2^32, Now we increment by 1 and will have a server time of 0. If we send in 0 it is earlier than the last-pointer-grab time. On the other hand if we send in our last state from updating X time we are later than the server time. To a certain degree this is broken in the X11 specification and if the X-Server behaves exactly like described in the spec we won't be able to fix it. KWin cannot use the CurrentTime check as we need to be explicit in the time we request, or we would run into other bugs. So currently what I see is that we need to relax our conditions in order to get the grab still working, but window management will probably still be broken, till some other application requests a pointer grab with 0. -- You are receiving this mail because: You are watching all bug changes.
