1460696 - Fixed-pos item inside sticky-pos item gets clipped improperly during async scrolling

Status: RESOLVED DUPLICATE of bug 1514291

(Core :: Panning and Zooming, defect, P3)

Description

[Kartikaya Gupta (email:[e-mail])]

STR:
1. Load the attachment (derived from markus' test case in bug 1425565)
2. Scroll all the way down and click to ensure a main-thread repaint happens
3. Scroll to the top (without moving mouse or doing anything that might trigger a repaint)

Expected:
Green square in top-left, blue bar in the middle

Actual:
Green square in the top-left gets clipped away. Once a repaint happens it comes back.

Since the main-thread repaint fixes the visual issue, presumably this is a bug in how AsyncCompositionManager is translating clips for async scrolling. But who knows, maybe the layer tree or display list is wrong.

Comment 1

[Kartikaya Gupta (email:[e-mail])]

Attachment: Test case

Comment 2

[Botond Ballo [:botond]]

This looks very much like bug 1514291. I'm going to forward-dupe as there's a reftest there and a partial diagnosis.