Clarify precedence of font-feature-settings descriptor and font-variant property #7498
Description
I've put a test up at https://jsbin.com/veqidew/edit?html,output, here it is too:
<style>
@font-face {
font-family: Lato-On;
src: url("https://bfo.com/misc/Lato-Medium-Liga.ttf");
font-feature-settings: 'liga' on;
}
@font-face {
font-family: Lato-Off;
src: url("https://bfo.com/misc/Lato-Medium-Liga.ttf");
font-feature-settings: 'liga' off;
}
.feature-on {
font-family: Lato-On;
}
.feature-off {
font-family: Lato-Off;
}
.variation-off {
font-variant-ligatures: none;
}
.variation-on {
font-variant-ligatures: initial; /* = normal */
}
p {
font-size: 100px;
margin: 0;
}
</style>
<body>
<p class="feature-off variation-off">fi</p>
<p class="feature-on variation-off">fi</p>
<p class="feature-off variation-on">fi</p>
<p class="feature-on variation-on">fi</p>
</body>The font precedence rules in both Fonts-3 and Fonts-4 seem clear - we are to:
- apply the default rules
- apply the
font-feature-settingsdescriptor - apply the
font-variantproperties
Which means that we start with the "liga" feature on (the default), that's overridden by the font-feature-settings descriptor, and is then always overridden by the font-variant-ligatures property - the initial value is "normal" which turns it on, or I can set to "none" which turns it off. But it will always change - there is no font-variant-ligatures value that means "don't change anything".
This means that the first two paragraphs of the test have no change, and the second two have a ligature.
Correct?
The reason I ask is that's not the behaviour in Webkit or Gecko, which give precedence to font-feature-settings (Blink doesn't support the descriptor). It's also not what's being tested in https://wpt.fyi/results/css/css-fonts/font-feature-resolution-001.html from where the above test was derived, which came from the Chromium team. So I have a nagging doubt I have misunderstood. I've raised a PR anyway for that test, if I'm wrong it can be closed.
Related: #4358 - I think this could be closed, or at least reduced to remove font-feature-settings given you've got two browsers implementing the descriptor.