With APZ turned on there is a few places where it seems like we overscroll content. It is more easily reproducible on the settings app. Steps to reproduce: - Open the settings app - scroll to the bottom and quickly scroll to the top, letting kinetic panning scrolls Expected result: - The scroll stops when the list reach the top Actual result: - The scroll seems to continue over the list limit and the content is slowly replace by a opaque black. It does not reproduce all the time and I need often multiple tries to trigger it.

Also when it happens I see the vertical scrollbar slowly going down, which seems to indicate that the list size is growing while the scroll is ongoing.

Either a dupe or blocks bug 940706

(In reply to Milan Sreckovic [:milan] from comment #2) > Either a dupe or blocks bug 940706 I have an hard time to reproduce it on Settings now. But I can reproduce it on one of the everything.me collection. I'm using Games and load all the content, then I can reproduce again.

(In reply to Vivien Nicolas (:vingtetun) (:21) (RTO - Review Time Off until 09/12/13) from comment #3) > (In reply to Milan Sreckovic [:milan] from comment #2) > > Either a dupe or blocks bug 940706 > > I have an hard time to reproduce it on Settings now. But I can reproduce it > on one of the everything.me collection. I'm using Games and load all the > content, then I can reproduce again. With the patches from bug 944047 it seems like I can't reproduce the issue anymore. So I think Cwiis assumption that BrowserElementPanning.js can interact weirdly with APZ at some point may be correct.

Seems like I can reproduce it with all the latest patches. This is not easy but with various variation of speed I can see it in settings. Most of the time this is when I switch from one direction to an other. So top -> bottom -> top when the app is scrolled to the top.