1426948 - Scroll position jumps when scrolling by dragging the scrollbar

Status: UNCONFIRMED

(Core :: Layout, defect, P3)

Description

[Andreas Jung]

Attachment: bug.mp4

User Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0
Build ID: 20171206182557

Steps to reproduce:

Browser session open since a few days, the longer the browser is running the worse it becomes.

1. Drag the scrollbar.
2. Release the mouse button and immediately drag the scrollbar again.
3. Release the mouse button (move the mouse away from the scrollbar).



Actual results:

After step 3 the scroll position jumps to a semi-random place.

(Note that the hover / active state of the scrollbar is also completely out of-sync to the real mouse hover / click / drag)

In the attached video the rendering of the content also severely lags behind but the jumping of the scroll position also occurs if the rendering doesn't noticeably lag.


Expected results:

The scroll position should stay at the position it was when the mouse button was released in step 3 and not jump around.

Comment 1

[Jet Villegas (inactive)]

[ Triage 2017/02/20: P3 ]