2025570 - Google Maps highway labels look broken ever since Canvas Randomization was enabled by default

Status: RESOLVED FIXED

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

Description

[Daniel Holbert [:dholbert]]

STR:

1. Look at the Dumbarton Bridge (Highway 84 near Menlo Park, CA) in Google Maps:
   https://www.google.com/maps/@37.4748083,-122.122755,14.17z?entry=ttu&g_ep=EgoyMDI2MDMxOC4xIKXMDSoASAFQAw%3D%3D

ACTUAL RESULTS:
The "84" highway labels are awkwardly smeared and vertically stretched. Sometimes other highway labels show even-worse rendering artifacts. See attached screenshot.

EXPECTED RESULTS:
No such issues.

I'm using 150.0a1 (2026-03-23) (64-bit) with a fresh profile on Ubuntu 25.10.

mozregression says this was a regression from bug 2021606.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: screenshot

Comment 2

[Daniel Holbert [:dholbert]]

This might have the same root cause as bug 1827279, though the new thing is that it affects Nightly by-default (as of bug 2021606 landing a few days ago).

Comment 3

[Daniel Holbert [:dholbert]]

Note also that in bug 1827279 comment 0, there was a user-facing workaround:

there's a canvas-usage icon in the URLbar that I can click into to grant Google Maps permission to read back data from the canvas. If I do that, then I get expected-results

But in this bug here, there's no such icon (as you can see in the screenshot in comment 1) and there's no other obvious user-facing workaround.

Comment 4

[Daniel Holbert [:dholbert]]

[Tracking Requested - why for this release]: Visual regression affecting Google Maps

Comment 5

[Thorin [:thorin]]

fyi: they render fine for me on Windows 11 (Nvidia card) on Nightly 150.0a1 (2026-03-23) (64-bit)

• I assume efficient randomizing is enabled (I have studies and nimbus and stuff disabled)

Comment 6

[Tim Huang[:timhuang]]

The issue should be fixed by the RemoteSettings update.