1322499 - Bookmark font changes by itself

Status: UNCONFIRMED

(Core :: Graphics, defect, P3)

Description

[Ed]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0
Build ID: 20161129173726

Steps to reproduce:

Open Bookmarks from bookmarks toolbar and then to sub sub folder where there are a lot of items (bookmarks). 


Actual results:

I've noticed that if I use mouse wheel to scroll the long bookmarks list the font becomes pixelated (and more thin). If I stop scrolling and wait 1..2 seconds. FF redraws all the bookmarks with good (smooth and fat) font. 


Expected results:

Font should not change and should always be good and smooth.
What is going on?

Comment 1

[Milan Sreckovic [:milan] (needinfo for best results)]

Kats, is this low res tiling?

Comment 2

[Ed]

Attachment: FF-BookmarkFontJumping.mp4

This is a video of the bug made from a smartphone (sorry for 90 degree rotation, which smartphone did)

Comment 3

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

Doesn't look like low-res tiling. Looks more like the antialiasing is changing based on whether the layer is active or not. Markus?

Comment 4

[Markus Stange [:mstange]]

Sounds like another instance where layout thinks subpixel AA cannot be applied. Not sure if it's related to the other text stuff you're looking at, Mason.

Comment 5

[Mason Chang [Inactive] [:mchang]]

(In reply to Markus Stange [:mstange] from comment #4)
> Sounds like another instance where layout thinks subpixel AA cannot be
> applied. Not sure if it's related to the other text stuff you're looking at,
> Mason.

Thanks for the heads up. This is on Firefox 50, so we'd use cairo if he doesn't have acceleration. This is unrelated to Skia. But this does look like another instance of subpixel AA turning on/off.

Can you post your about support?

Comment 6

[Ed]

Attachment: about:support then "copy text to clipboard"

Comment 7

[Mason Chang [Inactive] [:mchang]]

Thanks for the about:support! Yeah this is Cairo, which is just the difference between subpixel and grayscale AA here.