1588788 - Variable font kerning: kerning deltas not applied when one uses font-weight, as opposed to font-variation-settings

Status: RESOLVED FIXED

(Core :: Layout: Text and Fonts, defect, P3)

Description

[madigens]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:69.0) Gecko/20100101 Firefox/69.0

Steps to reproduce:

This is a by-product of https://bugs.chromium.org/p/chromium/issues/detail?id=1003746. Follow the steps to reproduce there but use "font-weight: 900;" instead of "font-variation-settings: 'wght' 900;".

Actual results:

Kerning Variation deltas are not applied (glyphs barely move).

Expected results:

Kerning Variation deltas are applied (glyphs crash into each other on purpose).

Comment 1

[madigens]

(Oh, forgot to mention: testing this on Windows 10)

Comment 2

[Liviu Seplecan]

Hi @madigens, tested on Windows 10 - using FF builds: release 69.0.3, nightly 71.0a1 =>cannot reproduce the issue.
Further, I will add a component if isn't the right one please fell free to change it.
Regards,
Liviu

Comment 3

[Jonathan Kew [:jfkthame]]

Confirmed reproducible with Nightly on macOS.

(Liviu, note that the STR described in the Chromium report includes downloading and using a specific test font - if you missed this, it wouldn't reproduce.)

Comment 4

[Jonathan Kew [:jfkthame]]

The bug here occurs because we just pass the list of values from font-variation-settings directly to harfbuzz shaping, but fail to incorporate any values that should be set based on separate properties like font-weight.

Comment 5

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1588788 - Pass the correct variation settings to harfbuzz shaping, including any derived from font-weight/-stretch/-style properties. r=lsalzman

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c1a405056197
Pass the correct variation settings to harfbuzz shaping, including any derived from font-weight/-stretch/-style properties. r=lsalzman

Comment 7

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/c1a405056197

Comment 8

[madigens]

Thanks for fixing this!