Summary: hit-testing for the horizontal scroll bar of an overflow is off by by the width of the top border. To reproduce: open the testcase. The horizontal scrollbar doesn't respond to clicking and dragging. Clicking inside the blue rect just below the scrollbar gives this error in the console (if running a debug build): ERROR: KHTML says we hit a RenderWidget, but AppKit doesn't agree we hit the corresponding NSView. I have a patch, but like with bug 5829, I don't know how to make an automated test.
Created attachment 5152 [details] Testcase
Created attachment 5153 [details] Remove borderTop() from horizontal scrollbar rect computation
Removing keyword(s) cause bug is closed.
Removing keyword(s) since bug is fixed.
Removing Regression keyword from bugs already fixed.