1894332 - At https://www.bequiet.com/en/powersupply/4055 , firefox paints the undecoded portion of the image as bright white (which is jarring on the dark page)

Status: RESOLVED DUPLICATE of bug 1808149

(Core :: Graphics: ImageLib, defect)

Description

[Daniel Holbert [:dholbert]]

STR:

1. Visit https://www.bequiet.com/en/powersupply/4055 (on a slow enough network connection where it takes some noticeable time to decode the main image)

ACTUAL RESULTS:
As the image decodes from the top down, the bottom un-decoded portion is bright white.

EXPECTED RESULTS:
The un-decoded portion should be transparent, to avoid making this otherwise dark website have a super bright-white patch.

I've got a reduced testcase which I'll attach shortly.
Chromium and WebKit give EXPECTED RESULTS.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: (image for use in testcase)

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

Comment 3

[Daniel Holbert [:dholbert]]

Profile with the attached testcase (including screenshots that show the bright-white still-to-be-decoded part of the image):
https://share.firefox.dev/3QnOsXe

Comment 4

[Timothy Nikkel (:tnikkel)]

We have a bug open for this already (can't find it quickly), it's a regression from webrender. Basically the image is opaque when fully decoded, if we send over the partially decoded image it's still marked as opaque but all the undecoded pixels are empty, that case is not handled/we just paint the data that is in memory.