Bug 245179 – getKeyframes() returns equal "from" and "to" values for a "width" transition

• Component: Animations
• Status: RESOLVED FIXED

[Antoine Quint]

Starting a "width" transition for a simple <div> will return the same values for "from" and "to" when getKeyframes() is called. This cannot be correct since a transition cannot have the same from and to values. Digging into this, this is about this code in ComputedStyleExtractor::valueForPropertyInStyle():

        case CSSPropertyWidth:
            if (renderer && !renderer->isRenderOrLegacyRenderSVGModelObject()) {
                // According to http://www.w3.org/TR/CSS2/visudet.html#the-width-property,
                // the "width" property does not apply for non-replaced inline elements.
                if (!isNonReplacedInline(*renderer))
                    return zoomAdjustedPixelValue(sizingBox(*renderer).width(), style);
            }
            return zoomAdjustedPixelValueForLength(style.width(), style);

In this case we end up calling zoomAdjustedPixelValue(sizingBox(*renderer).width(), style) which simply does not use the values provided in the RenderStyle for the keyframe.

[Antoine Quint]

Created attachment 462334 [details]
testcase

[Antoine Quint]

Pull request: https://github.com/WebKit/WebKit/pull/4350

[Radar WebKit Bug Importer]

<rdar://problem/100223910>

[Antoine Quint]

I believe this got fixed along with bug 23924. Will add a new test though.

[EWS]

Committed 254793@main (1ed5a302e8a0): <https://commits.webkit.org/254793@main>

Reviewed commits have been landed. Closing PR #4350 and removing active labels.