1624225 - Variation font with no specifically-defined instances doesn't work in Gecko

Status: RESOLVED FIXED

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

Description

[Jonathan Kew [:jfkthame]]

Discovered in the course of investigating https://github.com/web-platform-tests/wpt/issues/22355: we fail to recognize variation axes in a font if there are no entries for specific font instances in the 'fvar' table. This is because we reject the table in gfxFontUtils::GetVariationData if the instanceCount field is zero.

However, it is in fact valid to have no instance records here, according to the spec. So we just need to remove that check and accept the table in this case.

Comment 1

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1624225 - Don't reject 'fvar' table in a variation font if no instance records are present, as the font is still valid. r=lsalzman

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0af3b4b7bd51
Don't reject 'fvar' table in a variation font if no instance records are present, as the font is still valid. r=lsalzman

Comment 3

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/0af3b4b7bd51