Affected versions

• 80.0a1 (2020-07-16)

Affected platforms

• macOS 10.15.6

Steps to reproduce

1. Launch FF.
2. Go to about:config and set fission.autostart and gfx.webrender.all to true.
3. Go to Wikipedia.com and reach any random article.
4. Toggle on Reader mode for the page.

Expected result

• The page is successfully rendered in reader mode without any visual issues.

Actual result

• The page displays no text and all the sections of the page are missing.

Regression range

• First bad:2020-06-29
• Last good:2020-06-28
• Pushlog:https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=9388507a8b1f5c1550a7941483333db77478056f&tochange=31fb4a2a69124b6a21e5d8f44a0407d489749407
• Potential regressor: 1645607

Additional notes

• This issue only occurs while those preffs are activated.
• Printing the affected page renders same outcome on actual paper.
• I would consider this issue an S2, seeing as how a vital website function is broken, but only on this specific OS.

Hi vlucaci,

I'm unable to reproduce using the 2020-07-20 Nightly on macOS 10.15.5 using WebRender on this page: https://en.wikipedia.org/wiki/Apollo_11

Are you still able to reproduce reliably with the latest Nightly?

(I also had Fission enabled)

Hello

I have tried reproducing this issue on 80.0a1 (20200723095657) with macOS 10.15.6 but did not manage to encounter it again.

Okay, thanks vlucaci. Please let me know if you find some STR to reproduce this reliably, and we can re-open this.