1914307 - Tiny text on ditu.amap.com with privacy.resistFingerprinting

Status: UNCONFIRMED

(Core :: Privacy: Anti-Tracking, defect, P3)

Description

[lilydjwg]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:131.0) Gecko/20100101 Firefox/131.0

Steps to reproduce:

• my window.devicePixelRatio is 2
• set privacy.resistFingerprinting to true
• visit https://ditu.amap.com

Actual results:

The text on the map is tiny and hard to read. (It's also more detailed.)

Expected results:

The text should be larger, like when privacy.resistFingerprinting is false.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Privacy: Anti-Tracking' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Fatih Kilic [:fkilic]]

Looks like a WebGLRenderCapability issue.

Could you try setting your prefs as the following and confirm this is also the result that you get?

(Setting this should hopefully fix the issue)
privacy.resistFingerprinting = False
privacy.fingerprintingProtection = True
privacy.fingerprintingProtection.overrides = +AllTargets,-WebGLRenderCapability

(Setting this should cause the text size breakge)
privacy.resistFingerprinting = False
privacy.fingerprintingProtection = True
privacy.fingerprintingProtection.overrides = -AllTargets,+WebGLRenderCapability

Comment 3

[Fatih Kilic [:fkilic]]

If the above settings work, and this is a website you use quite often, then you can

Set your prefs accordingly to exempt this website from WebGLRenderCapability protection while we work on this issue.

privacy.resistFingerprinting = False
privacy.fingerprintingProtection = True
privacy.fingerprintingProtection.overrides = +AllTargets
privacy.fingerprintingProtection.granularOverrides = [{"firstPartyDomain":"amap.com","overrides":"-WebGLRenderCapability"}]

This was the same solution I was going to suggest for google sheets, but it doesn't work for gsheets for some reason

Comment 4

[lilydjwg]

Attachment: text large but incorrectly rendered

With privacy.fingerprintingProtection.overrides = +AllTargets,-WebGLRenderCapability the text size is large, but not readable (see attached screenshot).

The setting also fixes the rendering issue on https://act.mihoyo.com/ys/event/e20240822new-w0suak/index.html although the page still complains unsupported features. (It was black with +AllTargets.)

Comment 5

[Fatih Kilic [:fkilic]]

Looks like those are placeholders. Can you check if you see a Canvas Icon in the url bar? If so click on it to enable reading of canvases. (This assumes you are not on a mobile device, we currently don't have UI for enabling canvas reading on mobile)

Comment 6

[lilydjwg]

Yes, enabling canvas reading fixes the text! I didn't notice the button, and I don't see where to manage this permission.

Comment 7

[Fatih Kilic [:fkilic]]

Yes, it doesn't appear with the other permissions. You can click on the icon right to the Lock icon to revoke it though.

Comment 8

[Fatih Kilic [:fkilic]]

do note that amap.com seem to use a fingerprinter called fireye.js. I could be wrong but the web apis it uses aligns well with the other fingerprinters. So I can't tell 100% that it is a fingerprinter, but it looks like it