User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0

Steps to reproduce:

I haven't quite figured out what causes this yet. There's no other correlation than navigating to a new link.

Actual results:

Whether Fission is enabled or disabled, navigating to a new page can randomly cause some fonts to change to italics. I've seen this in both the Mercurial shortlog and on Reddit and a couple of other places. This change doesn't go away until you restart the browser.

Expected results:

Render normally.

Could you attach your about:support data, please?

If you go to about:config and set the gfx.webrender.force-disabled preference to false (and then restart the browser), does the problem still occur?

As of yet, I cannot reproduce with Webrender/Fission off.

I take that back. I just got it to happen again but it took longer. The difference is that in some cases, bold isn't replace with italics. The italics is added. In Webrender, affected bold text is usually replaced with italic text.

I wonder -- do you use some kind of font management software that might enable/disable fonts while the browser is running? (I believe Adobe Creative Cloud does this, for example, or utilities like Font Activator; doubtless there are others.)

If you set gfx.e10s.font-list.shared to false and then restart the browser, does that prevent the problem?

(In reply to Jonathan Kew (:jfkthame) from comment #5)

I wonder -- do you use some kind of font management software that might enable/disable fonts while the browser is running? (I believe Adobe Creative Cloud does this, for example, or utilities like Font Activator; doubtless there are others.)

If you set gfx.e10s.font-list.shared to false and then restart the browser, does that prevent the problem?

I do have Adobe software installed but none of it is allowed to run at startup. I set the pref to false as described and I have not yet been able to reproduce the issue.

Set "regressions" field based on comment 6, and Severity S3 as a font cosmetic issue that on frequently-visited sites per the triage guideline.

Leman, are you still seeing this problem (with gfx.e10s.font-list.shared set back to true, if you were running with it disabled), or has it been fixed? I'm thinking that this might have had the same cause as bug 1673397, in which case it should now be resolved.

(In reply to Jonathan Kew (:jfkthame) from comment #8)

Leman, are you still seeing this problem (with gfx.e10s.font-list.shared set back to true, if you were running with it disabled), or has it been fixed? I'm thinking that this might have had the same cause as bug 1673397, in which case it should now be resolved.

Thank you for reminding me. I forgot that this was toggled off. So far I cannot reproduce the issue when set back to default.

OK, thanks. I think we can close this as "worksforme" at this point -- but if you do see the problem again, please re-open it and we can try to investigate further.