When you open up the plasmoid, you expect it (and mainly its textbox) to get focus. If not, it means you have to make two clicks to start chatting. Its very 'unnatural'. (I opened the plasmoid a few times, started chatting, and after pressing enter I realized that I chatted into the wrong window, because plasmoid just opened up and did not get focused)
Porting the line edit to PlasmaComponents from PlasmaWidgets gives us a focus property we can use.
http://paste.kde.org/477002/
That patch seems to have nothing to do with this bug.
wrong bug,.,... i am so sorry
I think it's fixed in newer version of the plasma components (KDE 4.9 maybe?). In any case it works on my system (all KDE master) and it's clearly not a KTP-QuickChat problem.