This happens for me while I'm switching tasks or moving windows (see attachments). I'm using AMD 5570 with open source drivers, OpenGL and the effect Wobbly Windows. Reproducible: Sometimes Steps to Reproduce: 1.It seems that switching desktops triggers this bug.
Created attachment 72433 [details] snapshot 1
Created attachment 72434 [details] snapshot 2
can you perform a quick check whether it also happens with the xrender backend? ("kcmshell4 kwincompositing", 3rd tab) Thanks
It seems to work with XRender. But after switching back to OpenGL I also failed to reproduce it.
probably a side-effect of another effect. Which effects are you using?
Following effects are enabled: blur boxswitch coverswitch dashboard desktopgrid diminactive fade flipswitch highlightwindow login logout minimizeanimation presentwindows screenshot slidingpopups startupfeedback taskbarthumbnail trackmouse translucency wobblywindows zoom BTW, the thumbnails for the taskbar are also affected.
Mini-/maximizing windows brings back correct thumbnails (for some time). Just changing the size of windows doesn't help.
This is still reproducible with KDE 4.9.2. Anything else I could test?
qdbus org.kde.kwin /KWin supportInformation might help
Created attachment 74826 [details] KWin's supportInformation
See whether it also happens when disabling "OpenGL 2" shaders (kcmshell4 kwincompositing, 3rd tab)
First impression: that solved the problem :-) BTW, do you know why disabling shaders shrings some windows to a very small size?
(In reply to comment #12) > First impression: that solved the problem :-) likely dupe of bug #300349 (and som others) then > BTW, do you know why disabling shaders shrinks some windows to a very small size? Häh? Can you please elaborate on this, ie. what windows are under what condition shrinked to what size (compared to their what actual one)?
Well, I can't reproduce that right now (I enabled/disabled shades some times). It was one Konsole with either 80x50 or maximized and one Konqueror with similar size. Both were shrinked to a pixel size about 160x50.
visually or really - ie. was the window just scaled down or actually resized?
It was really resized. First I saw the "strange" thumbnail of the Konsole (only the menu and the session tabs were visible). But when I switched to it I realized that the Konsole itself was that small.
The window lost its size - likely during some kwin restart, either for altering the graphicssystem or as result of a crash. That's nothing to actually worry about in this context.
Is this still reproducible?
(In reply to Alexander Mentyu from comment #18) > Is this still reproducible? No. Can be closed.