1835256 - Tofu boxes are shown for the Combining Diacritical Marks Supplement characters if font visibility is set to 1 or 2

Status: RESOLVED WORKSFORME

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

Description

[Simona Badau, Desktop QA]

Attachment: Screenshot with the issue

Found in

• Nighty 115.0a1

Affected versions

• Nightly 115.0a1

Tested platforms

• Affected platforms: macOS 12, Windows 10

Preconditions

• in about:config, set the preference "layout.css.font-visibility.private" to 1.

Steps to reproduce

1. Open a private window.
2. Navigate to Wikipedia and look for Combining Diacritical Marks Supplement .
3. Observe the characters.

Expected result

• The characters should be properly displayed in Private Browsing.

Actual result
During private browsing, some tofu boxes can be observed.

Regression range
This is not a regression, the font visibility preference is set to 3 on all previous versions: ESR, Beta, and Release.

Additional notes

• The tofu boxes are also displayed when the preference "layout.css.font-visibility.private" is set to 2.
• The tofu boxes are not displayed in normal browsing or when "layout.css.font-visibility.private" is set to 3.

Comment 1

[Simona Badau, Desktop QA]

Attachment: Screenshot on macOS

On macOS 11.7 and macOS 13 this issue seems no longer reproducible on the latest Nighty 116.0a - even though tofu boxes are still displayed, the results are the same in both private and normal browsing (for more details, please see the screenshot).

On Windows 10, the outcome is no longer affected by the value of the preference "layout.css.font-visibility.private". I observe identical results in Firefox, including both normal and private browsing modes, as well as in other browsers like Chrome.

Comment 2

[Simona Badau, Desktop QA]

Considering Comment 1, setting this to Resolved Worksforme.