2063719 - Border radius on Google Maps iFrame does not work (regression)

Status: UNCONFIRMED

(Core :: Graphics: Canvas2D, defect)

Description

[Paul Rhomberg]

Attachment: firefox-iframe-radius-repro.html

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:153.0) Gecko/20100101 Firefox/153.0

Steps to reproduce:

Please see the attached repro html.

Actual results:

When the iFrame that includes the Google Maps Embed API (e.g. regular maps, Street View, both affected) loads, the border radius no longer applies.

It does still apply to some of the HTML elements inside the iFrame, but not the main canvas.

Expected results:

The border radius should apply correctly, and the iFrame should not appear squareish.

This started happening ~4 weeks ago. I don't have the exact version pinned down, but I've been keeping my Firefox up to date and this is definitely new.

It's happening on many sites, including GeoGuessr.

Comment 1

[Paul Rhomberg]

Attachment: Bildschirmaufnahme 2026-08-14 um 22.09.36(1) (online-video-cutter.com).mp4

This shows that when zooming (repaint) the rounded-off corners flimmer

Comment 2

[BugBot [:suhaib / :marco]]

The Bugbug bot thinks this bug should belong to the 'Core::Graphics: Canvas2D' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 3

[Timothy Nikkel (:tnikkel)]

Can you use https://mozilla.github.io/mozregression/ to find out the exact change that caused this?

I would do it myself but the testcase needs to be run from a domain that is authorized to use the key.

Comment 4

[Paul Rhomberg]

Hi Timothy,

The regression tester landed on https://phabricator.services.mozilla.com/D303004 with the commit message "Bug 2043194 - Implement image cutouts using quad shaders. r=gw".

The public maps key I used is whitelisted for localhost:3000 so if you can test on that localhost port it will work.

Comment 5

[Paul Rhomberg]

Attachment: Mozregression output

Comment 6

[Timothy Nikkel (:tnikkel)]

Thanks!

Comment 7

[BugBot [:suhaib / :marco]]

:nical, since you are the author of the regressor, bug 2043194, could you take a look? Also, could you set the severity field?

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