1674169 - Blurry UI in macOS Mojave with gfx.e10s.font-list.shared = true

Status: NEW

(Core :: Layout: Text and Fonts, defect, P5)

Description

[bryan]

Attachment: Screenshot 2020-10-28 at 09.27.13.png

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:82.0) Gecko/20100101 Firefox/82.0

Steps to reproduce:

Launch Firefox on macOS Mojave with gfx.e10s.font-list.shared set to true

Actual results:

UI is blurry - e.g. the tabs, address bar, about Firefox dialog, etc.

Web content is unaffected.

Expected results:

Not blurry

Comment 1

[bryan]

Here is the thread that prompted this report, it includes some more details. A massive thank you to /u/nextbern who helped me find a work around for now.

https://redd.it/jjkq1m

Comment 2

[Jonathan Kew [:jfkthame]]

It looks like it's using a very bold font face, which is obviously wrong (but a plausible regression due to the change in bug 1533462), but it also looks like the rendering is excessively blurry, which I don't understand at all.

Could you please add a screenshot of how the same window appears on your system after you've disabled the gfx.e10s.font-list.shared pref, for comparison? Thanks.

Comment 3

[bryan]

Attachment: Screenshot 2020-10-29 at 19.01.22.png

Comment 4

[bryan]

I've uploaded another screenshot.

However, I don't think this is a Firefox problem. The thought occurred, that I use FiraSystemFontReplacement, which replaces macOS's system font with Fira Sans.

Removing that fixes Firefox with the config set to either true or false.

Comment 5

[Emilio Cobos Álvarez [:emilio]]

When you are using that replacement, does the UI of other apps get blurry too? Seems we might want to close this as invalid if so. If not it might be worth investigating why.

Comment 6

[BugBot [:suhaib / :marco]]

Set release status flags based on info from the regressing bug 1533462

Comment 7

[bryan]

I've been using FiraSystemFontReplacement for many years now and I can't recall any instances of this happening before. It's so ubiquitous for me that I didn't make the connection until taking more screenshots.

I can totally understand why you wouldn't want to support people who mess around with system files.

Comment 8

[Julien Cristau [:jcristau]]

gfx.e10s.font-list.shared will be turned off when 87 enters late beta next week.

Comment 9

[Jonathan Kew [:jfkthame]]

I don't think this can be regarded as a high-severity or -priority issue; it's a result of the user having installed a package that attempts to replace the macOS system font in an unsupported way, and moreover isn't even targeted at current macOS versions: https://github.com/jenskutilek/FiraSystemFontReplacement says it is for "Mac OS X 10.12 Sierra".

The "real" system font has undergone significant changes in subsequent OS versions (e.g. becoming a variable font), and Firefox tries to work correctly with it on all supported releases, but it's not surprising something as hacky and unsupported as this exhibits some issues.