Bug 180785 – ASSERT in RenderLayer::updateLayerPositionsAfterScroll using icloud.com - cached rects incorrect

• Component: Layout and Rendering
• Status: NEW

[Joseph Pecoraro]

ASSERT in RenderLayer::updateLayerPositionsAfterScroll using icloud.com - cached rects incorrect

Seen on WebKit r225753. Logged into icloud.com, resized the page, clicked an icon => ASSERT.

ASSERTION FAILED: !renderer().hasRepaintLayoutRects() || renderer().repaintLayoutRects().m_repaintRect == renderer().clippedOverflowRectForRepaint(renderer().containerForRepaint())
Source/WebCore/rendering/RenderLayer.cpp(940) : void WebCore::RenderLayer::updateLayerPositionsAfterScroll(WebCore::RenderGeometryMap *, UpdateLayerPositionsAfterScrollFlags)
1   0x3d78a382d WTFCrash
2   0x3cacf0ca6 WebCore::RenderLayer::updateLayerPositionsAfterScroll(WebCore::RenderGeometryMap*, unsigned int)
3   0x3cacf0df6 WebCore::RenderLayer::updateLayerPositionsAfterScroll(WebCore::RenderGeometryMap*, unsigned int)
4   0x3cacf0df6 WebCore::RenderLayer::updateLayerPositionsAfterScroll(WebCore::RenderGeometryMap*, unsigned int)
5   0x3cacf0df6 WebCore::RenderLayer::updateLayerPositionsAfterScroll(WebCore::RenderGeometryMap*, unsigned int)
6   0x3cacf0df6 WebCore::RenderLayer::updateLayerPositionsAfterScroll(WebCore::RenderGeometryMap*, unsigned int)
7   0x3cacf0df6 WebCore::RenderLayer::updateLayerPositionsAfterScroll(WebCore::RenderGeometryMap*, unsigned int)
8   0x3cacf08fa WebCore::RenderLayer::updateLayerPositionsAfterDocumentScroll()
9   0x3ca565dc0 WebCore::FrameView::updateLayerPositionsAfterScrolling()
10  0x3ca6fdf0c WebCore::ScrollView::completeUpdatesAfterScrollTo(WebCore::IntSize const&)
11  0x3ca6fe1c4 WebCore::ScrollView::scrollTo(WebCore::IntPoint const&)
12  0x3ca56a6c4 WebCore::FrameView::scrollTo(WebCore::IntPoint const&)
13  0x3ca6fda13 WebCore::ScrollView::setScrollOffset(WebCore::IntPoint const&)
14  0x3ca6fdb0c non-virtual thunk to WebCore::ScrollView::setScrollOffset(WebCore::IntPoint const&)
15  0x3ca703e8f WebCore::ScrollableArea::scrollPositionChanged(WebCore::IntPoint const&)
16  0x3ca703ddf WebCore::ScrollableArea::notifyScrollPositionChanged(WebCore::IntPoint const&)
17  0x3ca6ca3a8 WebCore::AsyncScrollingCoordinator::reconcileScrollingState(WebCore::FrameView&, WebCore::FloatPoint const&, WTF::Variant<std::optional<WebCore::FloatPoint>, std::optional<WebCore::FloatRect> > const&, bool, WebCore::ViewportRectStability, WebCore::ScrollingLayerPositionAction)
18  0x3ca6c97a4 WebCore::AsyncScrollingCoordinator::updateScrollPositionAfterAsyncScroll(unsigned long long, WebCore::FloatPoint const&, std::optional<WebCore::FloatPoint>, bool, WebCore::ScrollingLayerPositionAction)
19  0x3ca6c8163 WebCore::AsyncScrollingCoordinator::updateScrollPositionAfterAsyncScrollTimerFired()
20  0x3ca6d2591 WTF::Function<void ()>::CallableWrapper<std::__1::__bind<void (WebCore::AsyncScrollingCoordinator::*&)(), WebCore::AsyncScrollingCoordinator*> >::call()
21  0x3c800f48b WTF::Function<void ()>::operator()() const
22  0x3c80893c9 WebCore::Timer::fired()
23  0x3ca71b864 WebCore::ThreadTimers::sharedTimerFiredInternal()
24  0x3ca730141 WebCore::ThreadTimers::setSharedTimer(WebCore::SharedTimer*)::$_0::operator()() const
25  0x3ca7300f9 WTF::Function<void ()>::CallableWrapper<WebCore::ThreadTimers::setSharedTimer(WebCore::SharedTimer*)::$_0>::call()
26  0x3c800f48b WTF::Function<void ()>::operator()() const
27  0x3ca6f2fd5 WebCore::MainThreadSharedTimer::fired()
28  0x3ca792f59 WebCore::timerFired(__CFRunLoopTimer*, void*)
...

LLDB session:

> (lldb) bt 10
> * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0xbbadbeef)
>     frame #0: 0x00000003d78a3834 JavaScriptCore`::WTFCrash() at Assertions.cpp:272
>   * frame #1: 0x00000003cacf0ca6 WebCore`WebCore::RenderLayer::updateLayerPositionsAfterScroll(this=0x00000003e1ed1000, geometryMap=0x00007ffeea1809c0, flags=4) at RenderLayer.cpp:940
>     frame #2: 0x00000003cacf0df6 WebCore`WebCore::RenderLayer::updateLayerPositionsAfterScroll(this=0x00000003e72f15f0, geometryMap=0x00007ffeea1809c0, flags=4) at RenderLayer.cpp:945
>     frame #3: 0x00000003cacf0df6 WebCore`WebCore::RenderLayer::updateLayerPositionsAfterScroll(this=0x00000003e251a720, geometryMap=0x00007ffeea1809c0, flags=4) at RenderLayer.cpp:945
>     frame #4: 0x00000003cacf0df6 WebCore`WebCore::RenderLayer::updateLayerPositionsAfterScroll(this=0x00000003ebade850, geometryMap=0x00007ffeea1809c0, flags=0) at RenderLayer.cpp:945
>     frame #5: 0x00000003cacf0df6 WebCore`WebCore::RenderLayer::updateLayerPositionsAfterScroll(this=0x00000003ebadfd10, geometryMap=0x00007ffeea1809c0, flags=0) at RenderLayer.cpp:945
>     frame #6: 0x00000003cacf0df6 WebCore`WebCore::RenderLayer::updateLayerPositionsAfterScroll(this=0x00000003ebadfbe0, geometryMap=0x00007ffeea1809c0, flags=0) at RenderLayer.cpp:945
>     frame #7: 0x00000003cacf08fa WebCore`WebCore::RenderLayer::updateLayerPositionsAfterDocumentScroll(this=0x00000003ebadfbe0) at RenderLayer.cpp:887
>     frame #8: 0x00000003ca565dc0 WebCore`WebCore::FrameView::updateLayerPositionsAfterScrolling(this=0x00000003e66f5a00) at FrameView.cpp:2389
>     frame #9: 0x00000003ca6fdf0c WebCore`WebCore::ScrollView::completeUpdatesAfterScrollTo(this=0x00000003e66f5a00, scrollDelta=0x00007ffeea180ea0) at ScrollView.cpp:472
>
> (lldb) f
> frame #1: 0x00000003cacf0ca6 WebCore`WebCore::RenderLayer::updateLayerPositionsAfterScroll(this=0x00000003e1ed1000, geometryMap=0x00007ffeea1809c0, flags=4) at RenderLayer.cpp:940
>    937 	            computeRepaintRects(renderer().containerForRepaint(), geometryMap);
>    938 	    } else {
>    939 	        // Check that our cached rects are correct.
> -> 940 	        ASSERT(!renderer().hasRepaintLayoutRects() || renderer().repaintLayoutRects().m_repaintRect == renderer().clippedOverflowRectForRepaint(renderer().containerForRepaint()));
>    941 	        ASSERT(!renderer().hasRepaintLayoutRects() || renderer().repaintLayoutRects().m_outlineBox == renderer().outlineBoundsForRepaint(renderer().containerForRepaint()));
>    942 	    }
>    943 	    
> 
> (lldb) p renderer().hasRepaintLayoutRects()
> (bool) $0 = true
> 
> (lldb) p renderer().repaintLayoutRects()
> (WebCore::RepaintLayoutRects) $1 = {
>   m_repaintRect = (m_location = { x = 1168px (74752), y = 356px (22784) }, m_size = { width = 141px (9024), height = 141px (9024) })
>   m_outlineBox = (m_location = { x = 1169px (74816), y = 357px (22848) }, m_size = { width = 140px (8960), height = 139px (8896) })
> }
> 
> (lldb) p renderer().clippedOverflowRectForRepaint(renderer().containerForRepaint())
> (WebCore::LayoutRect) $2 = (m_location = { x = 0.015625px (1), y = 0px (0) }, m_size = { width = -5.74259e+06px (-367525888), height = 511.969px (32766) })

[Joseph Pecoraro]

I had Web Inspector open and docked to the bottom, I'm not sure if that impacts this.