Bug 243915 – `background-repeat` is incorrectly exposed through inline style

• Component: CSS
• Status: RESOLVED FIXED

[Simon Fraser (smfr)]

This testcase fails in WebKit:

    <div id="target" style="background-repeat: no-repeat;"></div>
    <script>
        let target = document.getElementById('target');
        target.textContent = target.style.length + ' rules';
    </script>

reporting `0 rules`. Other browsers correctly find one rule.

This causes failures on https://css3test.com which uses this technique to detect support for style properties.

The bug relates to how webkit expands `background-repeat` to `background-repeat-x` and `background-repeat-y`.

[Simon Fraser (smfr)]

Created attachment 461569 [details]
Testcase

[Simon Fraser (smfr)]

`PropertySetCSSStyleDeclaration::length()` is really API, so to fix this we'd either have to recompute the length by collapsing longhands, or not expand `background-repeat` to `background-repeat-x` and `background-repeat-y`.

[Simon Fraser (smfr)]

Maybe we could stop pretending that `background-repeat` is a shorthand.

[Simon Fraser (smfr)]

Pull request: https://github.com/WebKit/WebKit/pull/3292

[EWS]

Committed 253440@main (165b098dbd0b): <https://commits.webkit.org/253440@main>

Reviewed commits have been landed. Closing PR #3292 and removing active labels.

[Radar WebKit Bug Importer]

<rdar://problem/98690270>

[Anne van Kesteren]

*** Bug 252403 has been marked as a duplicate of this bug. ***