Bug 258948 – Multiple keywords for tech()

• Component: CSS
• Status: RESOLVED FIXED

[Oliver Williams]

The following code works correctly in Safari and loads an OpenType-SVG font:

    @font-face {
            font-family: "ComicColor";
            src: url("ComicColor-SVG.woff2") format(woff2) tech(color-SVG);
        }

However, the following code should load the OpenType-SVG font in Safari but instead it loads the COLRv1 font (which Safari does not support). 

        @font-face {
            font-family: "ComicColor";
            src: url("ComicColor-COLRv1.woff2") format(woff2) tech(variations, color-COLRv1),
                 url("ComicColor-SVG.woff2") format(woff2) tech(color-SVG);
        }


From reading the spec, it seems that tech() is meant to accept a comma-seperated list of values. Is it this that is confusing Safari and getting it to load the wrong font? When I only use one value for tech() things work as they should: 

        @font-face {
            font-family: "ComicColor";
            src: url("ComicColor-COLRv1.woff2") format(woff2) tech(color-COLRv1),
                 url("ComicColor-SVG.woff2") format(woff2) tech(color-SVG);
        }

[Vitor Roriz]

Thanks for reporting that. I think you are right.
I've got confused by https://github.com/web-platform-tests/wpt/blob/0a2fec9de6/css/css-fonts/parsing/font-face-src-tech.html#L45 :


>> // Unsupported technology (for example: no browser has incremental transfer yet), might be
>> // dropped from the list, next component of the list should be accepted."

The list here is probably referring to the `src list` and not the list of tech() arguments. Therefore we are currently validating it if we can handle at least one tech provided for a descriptor, instead of all of them.

We are missing such a invalid test case in WPT, I'll add one and fix that.

[Radar WebKit Bug Importer]

<rdar://problem/112020474>

[Vitor Roriz]

Pull request: https://github.com/WebKit/WebKit/pull/15697

[EWS]

Committed 266032@main (165f4f7106fc): <https://commits.webkit.org/266032@main>

Reviewed commits have been landed. Closing PR #15697 and removing active labels.

[Tim Nguyen (:ntim)]

https://github.com/web-platform-tests/wpt/pull/40950