Bug 264010 – Include additional translation in getBBox for SVGUseElement

• Component: SVG
• Status: RESOLVED FIXED

[Ahmad Saleem]

Hi Team,

While going through Blink's commit, I came across another failing test case:

Test Case: https://jsfiddle.net/onav6d90/show

^ Fails in Safari Technology Preview 181 and WebKit ToT. Passes in Chrome Canary 120 and Firefox Nightly 121.

Blink Commit: https://chromium.googlesource.com/chromium/blink/+/99b52757a16d0a300b77c83c27c443d70ba78f9c

Just wanted to raise, so we can fix it.

Thanks!

[Radar WebKit Bug Importer]

<rdar://problem/118082623>

[Ahmad Saleem]

* Source/WebCore/rendering/svg/legacy/LegacyRenderSVGContainer.h:

> Make it public:

FloatRect objectBoundingBox() const final { return m_objectBoundingBox.value_or(FloatRect()); }

* Source/WebCore/rendering/svg/legacy/LegacyRenderSVGTransformableContainer.h:

> Add as public:

const FloatSize& additionalTranslation() const { return m_additionalTranslation; }

* Source/WebCore/svg/SVGUseElement.cpp:


FloatRect SVGUseElement::getBBox(StyleUpdateStrategy styleUpdateStrategy)
{
    if (styleUpdateStrategy == AllowStyleUpdate)
        protectedDocument()->updateLayoutIgnorePendingStylesheets({ LayoutOptions::TreatContentVisibilityHiddenAsVisible, LayoutOptions::TreatContentVisibilityAutoAsVisible }, this);

    if (!renderer())
        return { };

    auto* transformableContainer = dynamicDowncast<LegacyRenderSVGTransformableContainer>(renderer());
    // Don't apply the additional translation if the oBB is invalid.
    if (!transformableContainer->isObjectBoundingBoxValid())
        return { };

    // FIXME: Preferably this would just use objectBoundingBox() (and hence
    // don't need to override SVGGraphicsElement::getBBox at all) and be
    // correct without additional work. Although it does not work due to
    // problem stemming from including the additional translation directly
    // on the renderer corresponding to the SVGUseElement.
    FloatRect bbox = transformableContainer->objectBoundingBox();
    bbox.move(transformableContainer->additionalTranslation());
    return bbox;
}

* Source/WebCore/svg/SVGUseElement.h:

FloatRect getBBox(StyleUpdateStrategy = AllowStyleUpdate) override;

_____________________

It compiles and progresses.

[Ahmad Saleem]

It progresses 'SVGGraphicsElement.getBBox-05.html' -> 

FAIL use with fill assert_approx_equals: use1.getBBox().x {"fill":true,"stroke":false,"markers":false,"clipped":false} expected 70 +/- 0.1 but got 20

to

PASS use with fill

[Ahmad Saleem]

Pull request: https://github.com/WebKit/WebKit/pull/51242

[EWS]

Committed 302400@main (e53a0bba5e47): <https://commits.webkit.org/302400@main>

Reviewed commits have been landed. Closing PR #51242 and removing active labels.