1157070 - Expanding window cause unwanted scrollbar when using flexible box with APZ

Status: RESOLVED DUPLICATE of bug 1157579

Description

[Xidorn Quan [:xidorn] UTC+11]

Step to reproduce:
1. Open an e10s window
2. Open data:text/html,<body%20style="display:flex;width:100%;height:100%;margin:0">
3. Slowly enlarge the window, or just press F11 enter fullscreen mode

This issue shows on Windows, but I cannot reproduce it on Linux.

Comment 1

[Xidorn Quan [:xidorn] UTC+11]

Sometimes it could be really annoying that, the horizontal and vertical scrollbars keep appearing alternately infinitely.

Comment 2

[Daniel Holbert [:dholbert]]

Can you get the scrollbar to stick around, or does it just briefly flash & disappear?

(I can't repro on Linux or Win 8.1, FWIW.)

Comment 3

[Xidorn Quan [:xidorn] UTC+11]

It seems to be a bug related to APZ instead of e10s.

I cannot reproduce this problem today when I open Nightly. Later I realize that it is probably related to APZ which was enabled for one day yesterday.

This problem can be easily reproduced just in about:home, where the issue is far more annoying than the test page I put in comment 0.

Comment 4

[Xidorn Quan [:xidorn] UTC+11]

FYI, to enable APZ, you need to switch on layers.async-pan-zoom.enabled in about:config, and restart Firefox.

Comment 5

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

This appears to be the same issue as bug 1157579. I can repro on Linux with APZ enabled and the patch I have for that bug seems to fix it.