Bug 303208

At least since version 4.5.5 there is a bug with the highlighting of the icon in the Task Manager widget: the window may get the flag 'attention required' turned on but the flag is not dropped after the window gains focus. I use 'Focus follows mouse' (a.k.a. Sloppy focus) so the window may gain focus by entering it's display area with mouse cursor - without clicking. With this setting I can observe the problem not always but often (several times a day). Giving the focus to the window by clicking in it or it's icon usually clears the flag.

Window with this flag are highlighted in the Task Manager widget (the widget typically placed on the main panel). I've modified my system to highlight the window's icon in Task Manager with red color (the original theme does not make it very distinct) and I'll attach a screenshot with a single Firefox window opened on the desktop that has focus (as shown by blue decoration of the window), but still with red icon on the taskbar. The feature is useful for example when a iconified window with IM conversation receives a new message.

I suspect that there are more bugs related to handling of this flag because I often get the window's icon highlighted without an obvious reason, but I'm not able to pinpoint it.

Reproducible: Sometimes

Steps to Reproduce:
I'm not sure how much it is related to the bug but it's the only thing that I can think of and may have influence:
1. System settings-> Window Behaviour -> tab Focus -> combobox Policy is set to "Focus Follows Mouse'
Actual Results:  
The window's icon is displayed with 'requires attention' style even when the window has focus. 

Expected Results:  
When the window has focus or gains focus by any means, the 'requires attention' style should be cleared.

I did have a look on Task Manager widget source code and as far as I could see it is only passing the 'requires attention' flag around, but the flag value is actually generated by kwin.