Attachment 458008 Details for Bug 238589 – Patch

[patch] Patch

bug-238589-20220420132218.patch (text/plain), 22.45 KB, created by Simon Fraser (smfr) on 2022-04-20 13:22:19 PDT

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Creator: Simon Fraser (smfr)

Created: 2022-04-20 13:22:19 PDT

Size: 22.45 KB

patch

obsolete

>Subversion Revision: 292975
>diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
>index db7e6cbd3de90d6c5e8187fedbcb0daf708da0f3..4559790678825eea856f3d6f9694ee6b10048c28 100644
>--- a/Source/WebCore/ChangeLog
>+++ b/Source/WebCore/ChangeLog
>@@ -1,3 +1,48 @@
>+2022-04-19  Simon Fraser  <simon.fraser@apple.com>
>+
>+        REGRESSION (r281913): Map toolbar flickers when dragging the map on https://gis.ee/
>+        https://bugs.webkit.org/show_bug.cgi?id=238589
>+        <rdar://90483049>
>+
>+        Reviewed by NOBODY (OOPS!).
>+        
>+        If a layer has negative z-order descendants, and one of those descendants becomes
>+        composited, then that layer also has to composite, because its foreground needs to render in
>+        front of those descendants. But this is tricky, because the compositing toggle is
>+        out-of-order; we only know that the layer has to get composited after processing
>+        descendants.
>+
>+        In particular, this created a problem with the overlap map, which tracks sets of rectangles
>+        in "compositing scopes" via LayerOverlapMap. The delayed compositing toggle of the layer
>+        with negative z-order descendants meant that any layers processed up to that point had their
>+        bounds added in the wrong overlap scope. This resulted in subsequent bad overlap testing,
>+        and a failure to make later layers composited.
>+
>+        The previous fix in this area (r281913) was incorrect. Revert it, and do a better fix, which
>+        is to speculatively push an overlap map entry for the layer with negative z-order
>+        descendants, if necessary. If this layer ends up not getting composited, we unwind the
>+        speculative push, which will merge that scope with its parent scope.
>+
>+        In addition give OverlapMapContainer (an "overlap scope") a RenderLayer& which we can use
>+        for logging, and to assert on correct behavior; it is not otherwise used in release builds.
>+
>+        Tests: compositing/layer-creation/overlap-with-negative-z-layers.html
>+               compositing/layer-creation/subtree-div-overlaps-multiple-negative-z-divs.html
>+
>+        * rendering/LayerOverlapMap.cpp:
>+        (WebCore::OverlapMapContainer::OverlapMapContainer):
>+        (WebCore::OverlapMapContainer::scopeLayer const):
>+        (WebCore::OverlapMapContainer::dump const):
>+        (WebCore::LayerOverlapMap::LayerOverlapMap):
>+        (WebCore::LayerOverlapMap::add):
>+        (WebCore::LayerOverlapMap::pushCompositingContainer):
>+        (WebCore::LayerOverlapMap::popCompositingContainer):
>+        * rendering/LayerOverlapMap.h:
>+        * rendering/RenderLayerCompositor.cpp:
>+        (WebCore::RenderLayerCompositor::computeCompositingRequirements):
>+        (WebCore::RenderLayerCompositor::traverseUnchangedSubtree):
>+        (WebCore::RenderLayerCompositor::updateOverlapMap const):
>+
> 2022-04-18  Matt Woodrow  <mattwoodrow@apple.com>
> 
>         Implement support for aligning baselines through subgrids
>diff --git a/Source/WebCore/rendering/LayerOverlapMap.cpp b/Source/WebCore/rendering/LayerOverlapMap.cpp
>index ae225c4564192e524d0c27568b225505b8bc80af..bfe362d03e7ad75827630dd7590baefad14493a5 100644
>--- a/Source/WebCore/rendering/LayerOverlapMap.cpp
>+++ b/Source/WebCore/rendering/LayerOverlapMap.cpp
>@@ -25,6 +25,7 @@
> 
> #include "config.h"
> #include "LayerOverlapMap.h"
>+#include "Logging.h"
> #include "RenderLayer.h"
> #include <wtf/text/TextStream.h>
> 
>@@ -73,8 +74,9 @@ static TextStream& operator<<(TextStream& ts, const RectList& rectList)
> class OverlapMapContainer {
>     WTF_MAKE_FAST_ALLOCATED;
> public:
>-    OverlapMapContainer(const RenderLayer& rootLayer)
>+    OverlapMapContainer(const RenderLayer& rootLayer, const RenderLayer& scopeLayer)
>         : m_rootScope(rootLayer)
>+        , m_scopeLayer(scopeLayer)
>     {
>     }
> 
>@@ -84,6 +86,8 @@ public:
>     void append(std::unique_ptr<OverlapMapContainer>&&);
>     
>     String dump(unsigned) const;
>+    
>+    const RenderLayer& scopeLayer() const { return m_scopeLayer; }
> 
> private:
>     struct ClippingScope {
>@@ -160,6 +164,7 @@ private:
>     ClippingScope& rootScope() { return m_rootScope; }
> 
>     ClippingScope m_rootScope;
>+    const RenderLayer& m_scopeLayer;
> };
> 
> void OverlapMapContainer::add(const RenderLayer&, const LayoutRect& bounds, const Vector<LayerOverlapMap::LayerAndBounds>& enclosingClippingLayers)
>@@ -258,7 +263,7 @@ String OverlapMapContainer::dump(unsigned indent) const
> {
>     TextStream multilineStream;
>     multilineStream.increaseIndent(indent);
>-    multilineStream << "overlap container - root scope layer " <<  &m_rootScope.layer << " rects " << m_rootScope.rectList;
>+    multilineStream << "overlap container - root layer " <<  &m_rootScope.layer << " scope layer " << &m_scopeLayer << " rects " << m_rootScope.rectList;
> 
>     for (auto& childScope : m_rootScope.children)
>         recursiveOutputToStream(multilineStream, childScope, 1);
>@@ -273,7 +278,7 @@ LayerOverlapMap::LayerOverlapMap(const RenderLayer& rootLayer)
>     // Begin assuming the root layer will be composited so that there is
>     // something on the stack. The root layer should also never get an
>     // popCompositingContainer call.
>-    pushCompositingContainer();
>+    pushCompositingContainer(rootLayer);
> }
> 
> LayerOverlapMap::~LayerOverlapMap() = default;
>@@ -284,8 +289,11 @@ void LayerOverlapMap::add(const RenderLayer& layer, const LayoutRect& bounds, co
>     // contribute to overlap as soon as their composited ancestor has been
>     // recursively processed and popped off the stack.
>     ASSERT(m_overlapStack.size() >= 2);
>-    m_overlapStack[m_overlapStack.size() - 2]->add(layer, bounds, enclosingClippingLayers);
>-    
>+    auto& container = m_overlapStack[m_overlapStack.size() - 2];
>+    container->add(layer, bounds, enclosingClippingLayers);
>+
>+    LOG_WITH_STREAM(CompositingOverlap, stream << "layer " << &layer << " contributes to overlap in the scope of layer " << &container->scopeLayer() << ", added to map " << *this);
>+
>     m_isEmpty = false;
> }
> 
>@@ -294,13 +302,14 @@ bool LayerOverlapMap::overlapsLayers(const RenderLayer& layer, const LayoutRect&
>     return m_overlapStack.last()->overlapsLayers(layer, bounds, enclosingClippingLayers);
> }
> 
>-void LayerOverlapMap::pushCompositingContainer()
>+void LayerOverlapMap::pushCompositingContainer(const RenderLayer& layer)
> {
>-    m_overlapStack.append(makeUnique<OverlapMapContainer>(m_rootLayer));
>+    m_overlapStack.append(makeUnique<OverlapMapContainer>(m_rootLayer, layer));
> }
> 
>-void LayerOverlapMap::popCompositingContainer()
>+void LayerOverlapMap::popCompositingContainer(const RenderLayer& layer)
> {
>+    ASSERT_UNUSED(layer, &m_overlapStack.last()->scopeLayer() == &layer);
>     m_overlapStack[m_overlapStack.size() - 2]->append(WTFMove(m_overlapStack.last()));
>     m_overlapStack.removeLast();
> }
>diff --git a/Source/WebCore/rendering/LayerOverlapMap.h b/Source/WebCore/rendering/LayerOverlapMap.h
>index e3061f0940a6629710cccdf3c6693380e63b4425..373d9ec721ccb6d2c547f08fc7ec71d7d62c78f0 100644
>--- a/Source/WebCore/rendering/LayerOverlapMap.h
>+++ b/Source/WebCore/rendering/LayerOverlapMap.h
>@@ -53,8 +53,8 @@ public:
>     bool overlapsLayers(const RenderLayer&, const LayoutRect&, const Vector<LayerAndBounds>& enclosingClippingLayers) const;
>     bool isEmpty() const { return m_isEmpty; }
> 
>-    void pushCompositingContainer();
>-    void popCompositingContainer();
>+    void pushCompositingContainer(const RenderLayer&);
>+    void popCompositingContainer(const RenderLayer&);
> 
>     const RenderGeometryMap& geometryMap() const { return m_geometryMap; }
>     RenderGeometryMap& geometryMap() { return m_geometryMap; }
>diff --git a/Source/WebCore/rendering/RenderLayerCompositor.cpp b/Source/WebCore/rendering/RenderLayerCompositor.cpp
>index 2353c1770692f3d7135c2891ae683fa343387c36..2bda53dd3d73056724e797d15dc0facfddc28e14 100644
>--- a/Source/WebCore/rendering/RenderLayerCompositor.cpp
>+++ b/Source/WebCore/rendering/RenderLayerCompositor.cpp
>@@ -1061,9 +1061,11 @@ void RenderLayerCompositor::computeCompositingRequirements(RenderLayer* ancestor
>             layer.setIndirectCompositingReason(IndirectCompositingReason::Overlap);
>             LOG_WITH_STREAM(Compositing, stream << "layer " << &layer << " was sharing now will composite");
>         } else {
>-            overlapMap.pushCompositingContainer();
>-            didPushOverlapContainer = true;
>-            LOG_WITH_STREAM(CompositingOverlap, stream << "layer " << &layer << " will composite, pushed container " << overlapMap);
>+            if (!didPushOverlapContainer) {
>+                overlapMap.pushCompositingContainer(layer);
>+                didPushOverlapContainer = true;
>+                LOG_WITH_STREAM(CompositingOverlap, stream << "layer " << &layer << " will composite, pushed container " << overlapMap);
>+            }
>         }
> 
>         willBeComposited = true;
>@@ -1084,7 +1086,7 @@ void RenderLayerCompositor::computeCompositingRequirements(RenderLayer* ancestor
>         layerExtent.animationCausesExtentUncertainty |= layerExtent.hasTransformAnimation && compositingState.ancestorHasTransformAnimation;
>     } else if (layerPaintsIntoProvidedBacking) {
>         currentState.backingSharingAncestor = &layer;
>-        overlapMap.pushCompositingContainer();
>+        overlapMap.pushCompositingContainer(layer);
>         didPushOverlapContainer = true;
>         LOG_WITH_STREAM(CompositingOverlap, stream << "layer " << &layer << " will share, pushed container " << overlapMap);
>     }
>@@ -1098,18 +1100,33 @@ void RenderLayerCompositor::computeCompositingRequirements(RenderLayer* ancestor
>     bool anyDescendantHas3DTransform = false;
>     bool descendantsAddedToOverlap = currentState.hasNonRootCompositedAncestor();
> 
>-    unsigned newlyCompositedChildLayerCount = 0;
>-    for (auto* childLayer : layer.negativeZOrderLayers()) {
>-        computeCompositingRequirements(&layer, *childLayer, overlapMap, currentState, backingSharingState, anyDescendantHas3DTransform);
>+    if (layer.hasNegativeZOrderLayers()) {
>+        // Speculatively push this layer onto the overlap map.
>+        bool didSpeculativelyPushOverlapContainer = false;
>+        if (!didPushOverlapContainer) {
>+            overlapMap.pushCompositingContainer(layer);
>+            didPushOverlapContainer = true;
>+            didSpeculativelyPushOverlapContainer = true;
>+        }
> 
>-        // If we have to make a layer for this child, make one now so we can have a contents layer
>-        // (since we need to ensure that the -ve z-order child renders underneath our contents).
>-        if (!willBeComposited && currentState.subtreeIsCompositing)
>-            ++newlyCompositedChildLayerCount;
>-    }
>-    while (newlyCompositedChildLayerCount--) {
>-        layer.setIndirectCompositingReason(IndirectCompositingReason::BackgroundLayer);
>-        layerWillComposite();
>+        bool compositeForNegativeZOrderDescendant = false;
>+        
>+        for (auto* childLayer : layer.negativeZOrderLayers()) {
>+            computeCompositingRequirements(&layer, *childLayer, overlapMap, currentState, backingSharingState, anyDescendantHas3DTransform);
>+
>+            // If we have to make a layer for this child, make one now so we can have a contents layer
>+            // (since we need to ensure that the -ve z-order child renders underneath our contents).
>+            if (!willBeComposited && currentState.subtreeIsCompositing) {
>+                layer.setIndirectCompositingReason(IndirectCompositingReason::BackgroundLayer);
>+                layerWillComposite();
>+                compositeForNegativeZOrderDescendant = true;
>+            }
>+        }
>+
>+        if (!compositeForNegativeZOrderDescendant && didSpeculativelyPushOverlapContainer) {
>+            overlapMap.popCompositingContainer(layer);
>+            didPushOverlapContainer = false;
>+        }
>     }
> 
>     for (auto* childLayer : layer.normalFlowLayers())
>@@ -1246,7 +1263,7 @@ void RenderLayerCompositor::traverseUnchangedSubtree(RenderLayer* ancestorLayer,
>         // This layer now acts as the ancestor for kids.
>         currentState.compositingAncestor = &layer;
>         currentState.backingSharingAncestor = nullptr;
>-        overlapMap.pushCompositingContainer();
>+        overlapMap.pushCompositingContainer(layer);
>         didPushOverlapContainer = true;
>         LOG_WITH_STREAM(CompositingOverlap, stream << "unchangedSubtree: layer " << &layer << " will composite, pushed container " << overlapMap);
> 
>@@ -1255,7 +1272,7 @@ void RenderLayerCompositor::traverseUnchangedSubtree(RenderLayer* ancestorLayer,
>         // Too hard to compute animated bounds if both us and some ancestor is animating transform.
>         layerExtent.animationCausesExtentUncertainty |= layerExtent.hasTransformAnimation && compositingState.ancestorHasTransformAnimation;
>     } else if (layerPaintsIntoProvidedBacking) {
>-        overlapMap.pushCompositingContainer();
>+        overlapMap.pushCompositingContainer(layer);
>         currentState.backingSharingAncestor = &layer;
>         didPushOverlapContainer = true;
>         LOG_WITH_STREAM(CompositingOverlap, stream << "unchangedSubtree: layer " << &layer << " will share, pushed container " << overlapMap);
>@@ -2141,10 +2158,8 @@ void RenderLayerCompositor::addDescendantsToOverlapMapRecursive(LayerOverlapMap&
> 
> void RenderLayerCompositor::updateOverlapMap(LayerOverlapMap& overlapMap, const RenderLayer& layer, OverlapExtent& layerExtent, bool didPushContainer, bool addLayerToOverlap, bool addDescendantsToOverlap) const
> {
>-    if (addLayerToOverlap) {
>+    if (addLayerToOverlap)
>         addToOverlapMap(overlapMap, layer, layerExtent);
>-        LOG_WITH_STREAM(CompositingOverlap, stream << "layer " << &layer << " contributes to overlap, added to map " << overlapMap);
>-    }
> 
>     if (addDescendantsToOverlap) {
>         // If this is the first non-root layer to composite, we need to add all the descendants we already traversed to the overlap map.
>@@ -2153,7 +2168,7 @@ void RenderLayerCompositor::updateOverlapMap(LayerOverlapMap& overlapMap, const
>     }
> 
>     if (didPushContainer) {
>-        overlapMap.popCompositingContainer();
>+        overlapMap.popCompositingContainer(layer);
>         LOG_WITH_STREAM(CompositingOverlap, stream << "layer " << &layer << " is composited or shared, popped container " << overlapMap);
>     }
> }
>diff --git a/LayoutTests/ChangeLog b/LayoutTests/ChangeLog
>index d9dc4aba0af91bdcb1d7689e60cf5710110597fd..e2d9b4f9fb70a3872f9ca2a7d968f85c2f5ed112 100644
>--- a/LayoutTests/ChangeLog
>+++ b/LayoutTests/ChangeLog
>@@ -1,3 +1,20 @@
>+2022-04-19  Simon Fraser  <simon.fraser@apple.com>
>+
>+        REGRESSION (r281913): Map toolbar flickers when dragging the map on https://gis.ee/
>+        https://bugs.webkit.org/show_bug.cgi?id=238589
>+        <rdar://90483049>
>+
>+        Reviewed by NOBODY (OOPS!).
>+
>+        Move subtree-div-overlaps-multiple-negative-z-divs.html into the layer-creation directory.
>+        Add a new test.
>+
>+        * compositing/layer-creation/overlap-with-negative-z-layers-expected.html: Added.
>+        * compositing/layer-creation/overlap-with-negative-z-layers.html: Added.
>+        * compositing/layer-creation/subtree-div-overlaps-multiple-negative-z-divs-expected.html: Renamed from LayoutTests/compositing/subtree-div-overlaps-multiple-negative-z-divs-expected.html.
>+        * compositing/layer-creation/subtree-div-overlaps-multiple-negative-z-divs.html: Renamed from LayoutTests/compositing/subtree-div-overlaps-multiple-negative-z-divs.html.
>+        * fast/harness/render-tree-as-text-options-expected.txt: Test progressed; update results.
>+
> 2022-04-18  Tim Nguyen  <ntim@apple.com>
> 
>         [iOS] Skip CSS resize tests added by r292559
>diff --git a/LayoutTests/compositing/layer-creation/overlap-with-negative-z-layers-expected.html b/LayoutTests/compositing/layer-creation/overlap-with-negative-z-layers-expected.html
>new file mode 100644
>index 0000000000000000000000000000000000000000..2aa2bbd4536100ccc2c09d9229bf8ce77685c6a3
>--- /dev/null
>+++ b/LayoutTests/compositing/layer-creation/overlap-with-negative-z-layers-expected.html
>@@ -0,0 +1,49 @@
>+<!DOCTYPE html>
>+<html>
>+<head>
>+    <style>
>+        .wrapper {
>+            position: absolute;
>+            height: 400px;
>+            width: 400px;
>+            border: 1px solid black;
>+            z-index: 0;
>+        }
>+        
>+        .container {
>+            position: absolute;
>+            left: 0;
>+            top: 0;
>+            z-index: 0;
>+        }
>+
>+        .tile {
>+            position: absolute;
>+            width: 200px;
>+            height: 200px;
>+            left: 100px;
>+            top: 100px;
>+            background-color: orange;
>+        }
>+
>+        .green {
>+            position: relative;
>+            width: 200px;
>+            height: 200px;
>+            margin: 10px;
>+            background-color: green;
>+        }
>+    </style>
>+</head>
>+<body>
>+    <p>The green box should be on top.</p>
>+    <div class="wrapper">
>+        <div class="container" style="transform: translate3d(0px, 0px, 0px);">
>+            <div class="container">
>+                <div class="tile"></div>
>+            </div>
>+        </div>
>+        <div class="green"></div>
>+    </div>
>+</body>
>+</html>
>diff --git a/LayoutTests/compositing/layer-creation/overlap-with-negative-z-layers.html b/LayoutTests/compositing/layer-creation/overlap-with-negative-z-layers.html
>new file mode 100644
>index 0000000000000000000000000000000000000000..dea1a6299e8ffee0b7772302c1b50e8665fcb631
>--- /dev/null
>+++ b/LayoutTests/compositing/layer-creation/overlap-with-negative-z-layers.html
>@@ -0,0 +1,61 @@
>+<!DOCTYPE html>
>+<html>
>+<head>
>+    <style>
>+        .wrapper {
>+            position: absolute;
>+            height: 400px;
>+            width: 400px;
>+            border: 1px solid black;
>+            z-index: 0;
>+        }
>+        
>+        .container {
>+            position: absolute;
>+            left: 0;
>+            top: 0;
>+            z-index: 0;
>+        }
>+
>+        .negative {
>+            position: absolute;
>+            width: 20px;
>+            height: 20px;
>+            background-color: darkred;
>+        }
>+
>+        .tile {
>+            position: absolute;
>+            width: 200px;
>+            height: 200px;
>+            left: 100px;
>+            top: 100px;
>+            background-color: orange;
>+        }
>+
>+        .green {
>+            position: relative;
>+            width: 200px;
>+            height: 200px;
>+            margin: 10px;
>+            background-color: green;
>+        }
>+    </style>
>+</head>
>+<body>
>+    <p>The green box should be on top.</p>
>+    <div class="wrapper">
>+        <div class="container" style="transform: translate3d(0px, 0px, 0px);">
>+            <div class="container">
>+                <div class="tile"></div>
>+            </div>
>+            <div class="container">
>+                <div class="negative" style="transform: translate3d(50px, 50px, 0px); z-index: -3;"></div>
>+                <div class="negative" style="transform: translate3d(50px, 100px, 0px); z-index: -2;"></div>
>+                <div class="negative" style="transform: translate3d(50px, 150px, 0px); z-index: -1;"></div>
>+            </div>
>+        </div>
>+        <div class="green"></div>
>+    </div>
>+</body>
>+</html>
>diff --git a/LayoutTests/compositing/layer-creation/subtree-div-overlaps-multiple-negative-z-divs-expected.html b/LayoutTests/compositing/layer-creation/subtree-div-overlaps-multiple-negative-z-divs-expected.html
>new file mode 100644
>index 0000000000000000000000000000000000000000..3129daefb1ab0d6410fc7f5d9426a7a6b6aa00a8
>--- /dev/null
>+++ b/LayoutTests/compositing/layer-creation/subtree-div-overlaps-multiple-negative-z-divs-expected.html
>@@ -0,0 +1,2 @@
>+<!DOCTYPE html>
>+<div style="background:green;width:100px;height:100px"></div>
>diff --git a/LayoutTests/compositing/layer-creation/subtree-div-overlaps-multiple-negative-z-divs.html b/LayoutTests/compositing/layer-creation/subtree-div-overlaps-multiple-negative-z-divs.html
>new file mode 100644
>index 0000000000000000000000000000000000000000..df9df240741a0c5083e0f4f0a14322677d2539a0
>--- /dev/null
>+++ b/LayoutTests/compositing/layer-creation/subtree-div-overlaps-multiple-negative-z-divs.html
>@@ -0,0 +1,27 @@
>+<!DOCTYPE html>
>+<style>
>+.negative {
>+  z-index: -1;
>+}
>+.abs {
>+  position: absolute;
>+}
>+.green {
>+  width: 100px;
>+  height: 100px;
>+  background-color: green;
>+}
>+
>+.red {
>+  width: 100px;
>+  height: 100px;
>+  background-color: red;
>+  will-change: transform;
>+}
>+</style>
>+<body>
>+<div class="negative abs">
>+  <div class="red"></div>
>+</div>
>+<div class="negative abs green"></div>
>+</body>
>diff --git a/LayoutTests/compositing/subtree-div-overlaps-multiple-negative-z-divs-expected.html b/LayoutTests/compositing/subtree-div-overlaps-multiple-negative-z-divs-expected.html
>deleted file mode 100644
>index 3129daefb1ab0d6410fc7f5d9426a7a6b6aa00a8..0000000000000000000000000000000000000000
>--- a/LayoutTests/compositing/subtree-div-overlaps-multiple-negative-z-divs-expected.html
>+++ /dev/null
>@@ -1,2 +0,0 @@
>-<!DOCTYPE html>
>-<div style="background:green;width:100px;height:100px"></div>
>diff --git a/LayoutTests/compositing/subtree-div-overlaps-multiple-negative-z-divs.html b/LayoutTests/compositing/subtree-div-overlaps-multiple-negative-z-divs.html
>deleted file mode 100644
>index df9df240741a0c5083e0f4f0a14322677d2539a0..0000000000000000000000000000000000000000
>--- a/LayoutTests/compositing/subtree-div-overlaps-multiple-negative-z-divs.html
>+++ /dev/null
>@@ -1,27 +0,0 @@
>-<!DOCTYPE html>
>-<style>
>-.negative {
>-  z-index: -1;
>-}
>-.abs {
>-  position: absolute;
>-}
>-.green {
>-  width: 100px;
>-  height: 100px;
>-  background-color: green;
>-}
>-
>-.red {
>-  width: 100px;
>-  height: 100px;
>-  background-color: red;
>-  will-change: transform;
>-}
>-</style>
>-<body>
>-<div class="negative abs">
>-  <div class="red"></div>
>-</div>
>-<div class="negative abs green"></div>
>-</body>
>diff --git a/LayoutTests/fast/harness/render-tree-as-text-options-expected.txt b/LayoutTests/fast/harness/render-tree-as-text-options-expected.txt
>index 0d91f5dd84f9506b43032b5609c7a1a6614f7773..d9945c7cdea7ee31ed90615a835445158f80e9bd 100644
>--- a/LayoutTests/fast/harness/render-tree-as-text-options-expected.txt
>+++ b/LayoutTests/fast/harness/render-tree-as-text-options-expected.txt
>@@ -14,5 +14,5 @@ layer at (0,0) size 800x600 (composited [root], bounds=at (0,0) size 800x600, dr
>             RenderSVGRect {rect} at (18,278) size 100x100 [fill={[type=SOLID] [color=#0000FF]}] [x=10.00] [y=20.00] [width=100.00] [height=100.00]
>           RenderText {#text} at (0,0) size 0x0
>    positive z-order list (1)
>-    layer at (8,8) size 200x400
>+    layer at (8,8) size 200x400 (composited [overlap], bounds=at (0,0) size 200x400, drawsContent=0, paints into ancestor=0)
>       RenderBlock (relative positioned) zI: 1 {DIV} at (0,0) size 200x400

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Attachments on bug 238589: 457855 | 457958 | 457961 | 458008