Created attachment 96119 [details]
Screenshot with the problem

Hi
Thanks for reporting !
In general splitter have been rendered as "invisible" in breeze to unclutter the UI. The existence of the splitter being hinted only by the change of cursor when you mouse over it. 
Now I do agree that it looks somewhat awkward in the screenshot. 
Before I look for a solution, could you post screenshots on how it look with other styles ? 
(e.g. oxygen, fusion -if it is Qt5, or plastique -if it is Qt4)  ?

thanks in advance,

Hugo

(In reply to Hugo Pereira Da Costa from comment #2)
> ... The existence of the splitter being hinted only by the change of
> cursor when you mouse over it. 

Which, of course, presupposes one _knows_ the splitter is there. ;)

(In reply to Paul from comment #3)
> (In reply to Hugo Pereira Da Costa from comment #2)
> > ... The existence of the splitter being hinted only by the change of
> > cursor when you mouse over it. 
> 
> Which, of course, presupposes one _knows_ the splitter is there. ;)

Sure. No objection against that :)
But again, the idea behind is that: in general, you should not need the splitter: this should be the responsibility of the app to make sure that things are properly displayed and don't need resize. 
In the (hopefully rare) cases that interaction with the splitter is needed, then you would think that it is easy enough to figure that there is one here (if only because part of the content is chopped).

Best example that comes to my mind is dolphin's side panel.

Anyway: I am not saying that the situation is ideal, and cannot be improved, nor that you are wrong, I am just trying to motivate the decisions that were made so far ...

For some reason I can't switch my KMail to Fusion or Oxygen style, and can't debug it right now. In general Oxygen in KDE4 was also bad with splitters in some apps they were really hard to grab.

I'll come back later with screenshots.

*** Bug 415529 has been marked as a duplicate of this bug. ***