1625023 - Header and sidebar background isn't painted properly sometimes on https://wiki.mozilla.org/

Status: RESOLVED DUPLICATE of bug 1625571

(Core :: Graphics, defect, P3)

Description

[Matthew N. [:MattN]]

Attachment: wiki.mozilla.org screenshot

I don't have STR but I have two pinned tabs of pages on https://wiki.mozilla.org/ and the header/sidebar has started to be painted incorrectly intermittently in the last few days on Nightly when I select the tab. Leaving the tab and returning to it often causes it to fix itself.

Comment 1

[Matthew N. [:MattN]]

Attachment: wiki.mozilla.org screenshot tab 2 that had the problem at the same time

Comment 2

[Matthew N. [:MattN]]

Attachment: Graphics section of about:support

I'm on a new 2019 MBP 16" with dual monitors. The window that has the problem is normally on the non-retina display.

Comment 3

[Jamie Nicol [:jnicol]]

Thanks for the report. Do you know if this occurs if you only have one screen? When you say "normally on the non-retina display", does that mean that sometimes the problem can occur on the retina display too? Would you be able to run with webrender enabled for a while and see if it reproduces like that?

Do you have a feeling for when this started to occur? I'm guessing it's too intermittent for mozregression to work?

Comment 4

[Matthew N. [:MattN]]

(In reply to Jamie Nicol [:jnicol] from comment #3)

Thanks for the report. Do you know if this occurs if you only have one screen?

Not sure, as it's very rare for me to not have two screens attached and when I do it's only temporary so I wouldn't know if the problem occurred before or after detaching.

When you say "normally on the non-retina display", does that mean that sometimes the problem can occur on the retina display too?

I said normally because that's where I always notice it (I never put wikimo on my other screen) but I didn't want to rule it out.

Would you be able to run with webrender enabled for a while and see if it reproduces like that?

Sure, I'll try it now.

Do you have a feeling for when this started to occur?

Probably after 2020-03-15 (the week before I filed this).

I'm guessing it's too intermittent for mozregression to work?

I do see it every day so I could probably bisect somewhat with a lot of patience. I'll try now but I don't know how well it will work as I don't know specific STR yet.

Comment 5

[Timothy Nikkel (:tnikkel)]

Since this is a background image on the body element it is possible that bug 1625571 fixed this.

Comment 6

[Matthew N. [:MattN]]

FWIW I didn't see the issue today with WR enabled. If I don't see the problem for a few days with WR I can switch back to no WR to see if the problem is fixed there (and maybe bug 1625571 is the solution?).

Comment 7

[Jamie Nicol [:jnicol]]

Thanks Matthew. Please let us know if the issue is gone once you go back to non-WR. Hopefully bug 1625571 was indeed the cause!

Comment 8

[Matthew N. [:MattN]]

I haven't seen it again since switching Web Render off so it's probably a dupe of bug 1625571.