Description of problem: When using any of KWin's focus-follows-mouse type modes (i.e. not click-to-focus), KWin can go insane flipping the focus between the new window and the previously active window, when the windows overlap. This renders the entire desktop unusable until it sorts itself out, which can take some minutes. The more widgets there are in the affected windows, the longer it takes. For example, when the KDE control panel is involved, you might as well go make a cup of tea... As a workaround, setting a non-zero focus delay (e.g. 10ms) appears to make things behave normally. Version-Release number of selected component (if applicable): kdebase-3.5.5-0.1.fc6 How reproducible: 100% Steps to Reproduce: 1. Set KWin to focus-follows-mouse using Control Panel 2. Turn focus-delay OFF 3. Turn Auto-Raise OFF 4. Set up any two windows so that they overlap. 5. Waggle the mouse so that focus flips between them. 6. Watch the fun. This problem appears on i686 and x86_64. It does not appear (AFAICT) on a KDE 3.5.5 from the kde-redhat repository. Turning focus-stealing prevention off does not fix it. I haven't tried increasing it beyond "low".
Reproducible with kdebase-3.5.5-0.1.fc5 x86_64 This bug is described as resolved in http://bugs.kde.org/show_bug.cgi?id=135250 Someone should probably backport the patch listed there.
I rebuilt kdebase-3.5.5-0.1.fc5 rebuilt with the patch mentioned. Focus problem goes away. I did have to change the diff header in the patch to add the kwin subdirectory.
Created attachment 140120 [details] upstream patch for kde bug #135250
I can confirm the upstream patch works as advertised.
I will push new kdebase including this fix into FC5/FC6 update today. Many thanks for your report. Rex, thank for verifying this patch!
*** Bug 214265 has been marked as a duplicate of this bug. ***