[css-fonts-4] Font shorthand can not reliably parse oblique <angle>, needs <font-style-css3> exception

[drott]

The font shorthand property says:

The font property is, except as described below, a shorthand property for setting font-style, font-variant, font-weight, font-stretch, font-size, line-height, font-family at the same place in the stylesheet.

For font-stretch and font-variant exceptions are specified which restrict them to a restricted keyword syntax.

For font-style, no such exception is defined yet.

I believe however, that allowing oblique <angle> into the font shorthand syntax causes parsing tokenization ambiguities and would not work reliably.

I would suggest to change the syntax rule for font-style to use something like

<font-style-css3> = [normal | italic | oblique]

[litherum]

I don't think there are ambiguities. Nothing else in the font shorthand accepts an <angle>.

WebKit currently parses the full font-style syntax in the font shorthand.

[drott]

Thanks for your analysis, I think you're right, since font size and angle need a unit. I had in mind a case like font: oblique 20 sans-serif;

Does WebKit serialize an oblique value - say, 35deg - into the computed style of the font shorthand as ... oblique 35deg ...?

[litherum]

I don't have a build handy right now, so I can't check, but from code inspection, it looks like we don't right now (fontShorthandValueForSelectionProperties()). We probably should, though.

[litherum]

Is there anything left to do here?

[drott]

No, I think this can be closed.