ChangeLog

2021-09-06  Simon Fraser  <simon.fraser@apple.com>

        https://maya.land/monologues page renders incorrectly (filter should create containing block for fixed)

        https://bugs.webkit.org/show_bug.cgi?id=221964

        Reviewed by NOBODY (OOPS!).

        No new tests (OOPS!).

        * rendering/RenderElement.h:

        (WebCore::RenderElement::canContainFixedPositionObjects const):

        * rendering/RenderLayer.cpp:

        (WebCore::RenderLayer::RenderLayer):

        (WebCore::RenderLayer::flagsForUpdateLayerPositions):

        (WebCore::RenderLayer::updateLayerPositions):

        (WebCore::RenderLayer::clippingRootForPainting const):

        (WebCore::accumulateOffsetTowardsAncestor):

        (WebCore::RenderLayer::calculateClipRects const):

        * rendering/RenderLayer.h:

        (WebCore::RenderLayer::hasFilteredAncestor const):

2021-09-06  Simon Fraser  <simon.fraser@apple.com>

        Add a temporarily prefixed property for mask-mode, aliased to -webkit-mask-source-type

Source/WebCore/rendering/RenderElement.h

@@inline bool RenderElement::canContainFixedPositionObjects() const

{

    return isRenderView()

        || (isRenderBlock() && hasTransform())

457 || hasFilter()

        // FIXME: will-change should create containing blocks on inline boxes (bug 225035)

        || (isRenderBlock() && style().willChange() && style().willChange()->createsContainingBlockForOutOfFlowPositioned())

        || isSVGForeignObject()

Source/WebCore/rendering/RenderLayer.cpp

@@RenderLayer::RenderLayer(RenderLayerModelObject& rendererLayerModelObject)

    , m_hasCompositedScrollingAncestor(false)

    , m_hasTransformedAncestor(false)

    , m_has3DTransformedAncestor(false)

327 , m_hasFilteredAncestor(false)

    , m_insideSVGForeignObject(false)

    , m_indirectCompositingReason(static_cast<unsigned>(IndirectCompositingReason::None))

    , m_viewportConstrainedNotCompositedReason(NoNotCompositedReason)

@@OptionSet<RenderLayer::UpdateLayerPositionsFlag> RenderLayer::flagsForUpdateLaye

        if (parent->has3DTransformedAncestor() || (parent->transform() && !parent->transform()->isAffine()))

            flags.add(Seen3DTransformedLayer);

        if (parent->hasFilteredAncestor() || parent->hasFilter())

            flags.add(SeenFilteredLayer);

        if (parent->behavesAsFixed() || (parent->renderer().isFixedPositioned() && !parent->hasTransformedAncestor()))

            flags.add(SeenFixedLayer);

@@void RenderLayer::updateLayerPositions(RenderGeometryMap* geometryMap, OptionSet

    m_repaintStatus = NeedsNormalRepaint;

    m_hasTransformedAncestor = flags.contains(SeenTransformedLayer);

    m_has3DTransformedAncestor = flags.contains(Seen3DTransformedLayer);

1008 m_hasFilteredAncestor = flags.contains(SeenFilteredLayer);

    m_behavesAsFixed = flags.contains(SeenFixedLayer);

    setHasCompositedScrollingAncestor(flags.contains(SeenCompositedScrollingLayer));

@@void RenderLayer::updateLayerPositions(RenderGeometryMap* geometryMap, OptionSet

        if (!transform()->isAffine())

            flags.add(Seen3DTransformedLayer);

    }

    
    if (hasFilter())

        flags.add(SeenFilteredLayer);

10211029

10221030 // Fixed inside transform behaves like absolute (per spec).

1023 if (renderer().isFixedPositioned() && !m_hasTransformedAncestor) {

1031 if (renderer().isFixedPositioned() && !m_hasTransformedAncestor && !m_hasFilteredAncestor) {

        m_behavesAsFixed = true;

        flags.add(SeenFixedLayer);

    }

@@void RenderLayer::updateLayerPositions(RenderGeometryMap* geometryMap, OptionSet

    if (m_scrollableArea)

        m_scrollableArea->updateMarqueePosition();

1045 // FIXME: check behavesAsFixed.

    if (renderer().isFixedPositioned() && renderer().settings().acceleratedCompositingForFixedPositionEnabled()) {

        bool intersectsViewport = compositor().fixedLayerIntersectsViewport(*this);

        if (intersectsViewport != m_isFixedIntersectingViewport) {

@@RenderLayer* RenderLayer::clippingRootForPainting() const

        current = current->paintOrderParent();

        ASSERT(current);

2046 // FIXME: Maybe include filters.

        if (current->transform() || compositedWithOwnBackingStore(*current))

            return const_cast<RenderLayer*>(current);

@@static inline const RenderLayer* accumulateOffsetTowardsAncestor(const RenderLay

    // If the fixed renderer is inside a RenderFragmentedFlow, we should not compute location using localToAbsolute,

    // since localToAbsolute maps the coordinates from named flow to regions coordinates and regions can be

    // positioned in a completely different place in the viewport (RenderView).

2265 if (position == PositionType::Fixed && !fixedFragmentedFlowContainer && (!ancestorLayer || ancestorLayer == renderer.view().layer())) {

2275 if (position == PositionType::Fixed && layer->behavesAsFixed() && !fixedFragmentedFlowContainer && (!ancestorLayer || ancestorLayer == renderer.view().layer())) {

        // If the fixed layer's container is the root, just add in the offset of the view. We can obtain this by calling

        // localToAbsolute() on the RenderView.

        FloatPoint absPos = renderer.localToAbsolute(FloatPoint(), IsFixed);

@@void RenderLayer::calculateClipRects(const ClipRectsContext& clipRectsContext, C

    // A fixed object is essentially the root of its containing block hierarchy, so when

    // we encounter such an object, we reset our clip rects to the fixedClipRect.

4507 // FIXME: Check behavesAsFixed.

    if (renderer().isFixedPositioned()) {

        clipRects.setPosClipRect(clipRects.fixedClipRect());

        clipRects.setOverflowClipRect(clipRects.fixedClipRect());

Source/WebCore/rendering/RenderLayer.h

@@public:

    bool hasTransformedAncestor() const { return m_hasTransformedAncestor; }

    bool hasFilter() const { return renderer().hasFilter(); }

742 bool hasFilteredAncestor() const { return m_hasFilteredAncestor; }

743

    bool hasFilterOutsets() const { return !filterOutsets().isZero(); }

    IntOutsets filterOutsets() const;

    bool hasBackdropFilter() const

@@private:

        UpdatePagination                    = 1 << 3,

        SeenFixedLayer                      = 1 << 4,

        SeenTransformedLayer                = 1 << 5,

944 Seen3DTransformedLayer = 1 << 6,

945 SeenCompositedScrollingLayer = 1 << 7,

        SeenFilteredLayer                   = 1 << 6,

        Seen3DTransformedLayer              = 1 << 7,

        SeenCompositedScrollingLayer        = 1 << 8,

    };

    static OptionSet<UpdateLayerPositionsFlag> flagsForUpdateLayerPositions(RenderLayer& startingLayer);

@@private:

    bool m_hasTransformedAncestor : 1;

    bool m_has3DTransformedAncestor : 1;

1140 bool m_hasFilteredAncestor : 1;

1141

    bool m_insideSVGForeignObject : 1;

    unsigned m_indirectCompositingReason : 4; // IndirectCompositingReason