Bug 310596 – [GTK] ASSERTION FAILED: !m_deferredScrollDelta in WebCore::ScrollView::scrollTo from WebKit::LayerTreeHost::commitTransientZoom

• Component: WebKitGTK
• Status: RESOLVED DUPLICATE

[Sebastian Krzyszkowiak]

Triggered sometimes when using the pinch-to-zoom gesture. Relatively easily to reproduce by quickly pinching a lot for a while.

ASSERTION FAILED: !m_deferredScrollDelta
WebKit/Source/WebCore/platform/ScrollView.cpp(515) : virtual void WebCore::ScrollView::scrollTo(const WebCore::ScrollPosition&)
1   0x7f060f407b5c WebCore::ScrollView::scrollTo(WebCore::IntPoint const&)
2   0x7f060f2437dc WebCore::LocalFrameView::scrollTo(WebCore::IntPoint const&)
3   0x7f060f403e8c WebCore::ScrollView::setScrollOffset(WebCore::IntPoint const&)
4   0x7f060f40c79c WebCore::ScrollableArea::scrollPositionChanged(WebCore::IntPoint const&)
5   0x7f060f40ca33 WebCore::ScrollableArea::notifyScrollPositionChanged(WebCore::IntPoint const&)
6   0x7f060f368285 WebCore::AsyncScrollingCoordinator::reconcileScrollingState(WebCore::LocalFrameView&, WebCore::FloatPoint const&, mpark::variant<std::optional<WebCore::FloatPoint>, std::optional<WebCore::FloatRect> > const&, WebCore::ScrollType, WebCore::ViewportRectStability, WebCore::ScrollingLayerPositionAction)
7   0x7f060f364e51 WebCore::AsyncScrollingCoordinator::updateScrollPositionAfterAsyncScroll(WebCore::ProcessQualified<WTF::ObjectIdentifierGeneric<WebCore::ScrollingNodeIDType, WTF::ObjectIdentifierMainThreadAccessTraits<unsigned long>, unsigned long> >, WebCore::FloatPoint, std::optional<WebCore::FloatPoint>, WebCore::ScrollingLayerPositionAction, WebCore::ScrollType, WebCore::ViewportRectStability)
8   0x7f060f367eb5 WebCore::AsyncScrollingCoordinator::applyScrollPositionUpdate(WebCore::ScrollUpdate&&, WebCore::ScrollType, WebCore::ViewportRectStability)
9   0x7f060f368199 WebCore::AsyncScrollingCoordinator::applyScrollUpdate(WebCore::ScrollUpdate&&, WebCore::ScrollType, WebCore::ViewportRectStability)
10  0x7f060f3646db WebCore::AsyncScrollingCoordinator::requestScrollToPosition(WebCore::ScrollableArea&, WebCore::IntPoint const&, WebCore::ScrollPositionChangeOptions const&)
11  0x7f060f22c9a4 WebCore::LocalFrameView::requestScrollToPosition(WebCore::IntPoint const&, WebCore::ScrollPositionChangeOptions const&)
12  0x7f060f40cacb WebCore::ScrollableArea::setScrollPositionFromAnimation(WebCore::IntPoint const&)
13  0x7f060f3f87ed WebCore::ScrollAnimator::notifyPositionChanged(WebCore::FloatSize const&)
14  0x7f060f3f8b05 WebCore::ScrollAnimator::setCurrentPosition(WebCore::FloatPoint const&, WebCore::ScrollAnimator::NotifyScrollableArea)
15  0x7f060f3f8bf6 WebCore::ScrollAnimator::scrollToPositionWithoutAnimation(WebCore::FloatPoint const&, WebCore::ScrollClamping)
16  0x7f060f40441f WebCore::ScrollableArea::scrollToPositionWithoutAnimation(WebCore::FloatPoint const&, WebCore::ScrollClamping)
17  0x7f060f4045c9 WebCore::ScrollView::updateScrollbars(WebCore::IntPoint const&)::{lambda(WebCore::IntPoint)#1}::operator()(WebCore::IntPoint) const
18  0x7f060f40b427 WebCore::ScrollView::updateScrollbars(WebCore::IntPoint const&)
19  0x7f060f40b87d WebCore::ScrollView::setContentsSize(WebCore::IntSize const&)
20  0x7f060f256312 WebCore::LocalFrameView::setContentsSize(WebCore::IntSize const&)
21  0x7f060f2565ed WebCore::LocalFrameView::adjustViewSize()
22  0x7f060f261783 WebCore::LocalFrameViewLayoutContext::performLayout(bool)
23  0x7f060f26189f WebCore::LocalFrameViewLayoutContext::layout(bool)
24  0x7f060f2c22b1 WebCore::Page::setPageScaleFactor(float, WebCore::IntPoint const&, bool)
25  0x7f060cbd13bd WebKit::WebPage::didScalePage(double, WebCore::IntPoint const&)
26  0x7f060cbf352f WebKit::WebPage::scalePage(double, WebCore::IntPoint const&)
27  0x7f060cc28781 WebKit::LayerTreeHost::commitTransientZoom(double, WebCore::FloatPoint, WebCore::FloatPoint)
28  0x7f060cc1c529 WebKit::DrawingAreaCoordinatedGraphics::commitTransientZoom(double, WebCore::FloatPoint, WTF::CompletionHandler<void ()>&&)
29  0x7f060bdb5818 auto IPC::callMemberFunction<WebKit::DrawingArea, WebKit::DrawingArea, void (double, WebCore::FloatPoint, WTF::CompletionHandler<void ()>&&), std::tuple<double, WebCore::FloatPoint>, void ()>(WebKit::DrawingArea*, void (WebKit::DrawingArea::*)(double, WebCore::FloatPoint, WTF::CompletionHandler<void ()>&&), std::tuple<double, WebCore::FloatPoint>&&, WTF::CompletionHandler<void ()>&&)::{lambda((auto:1&&)...)#1}::operator()<double, WebCore::FloatPoint>(double&&, WebCore::FloatPoint&&) const
30  0x7f060bdb5861 void IPC::callMemberFunction<WebKit::DrawingArea, WebKit::DrawingArea, void (double, WebCore::FloatPoint, WTF::CompletionHandler<void ()>&&), std::tuple<double, WebCore::FloatPoint>, void ()>(WebKit::DrawingArea*, void (WebKit::DrawingArea::*)(double, WebCore::FloatPoint, WTF::CompletionHandler<void ()>&&), std::tuple<double, WebCore::FloatPoint>&&, WTF::CompletionHandler<void ()>&&)
31  0x7f060bdb676f void IPC::handleMessageAsync<Messages::DrawingArea::CommitTransientZoom, IPC::Connection, WebKit::DrawingArea, WebKit::DrawingArea, void (double, WebCore::FloatPoint, WTF::CompletionHandler<void ()>&&)>(IPC::Connection&, IPC::Decoder&, WebKit::DrawingArea*, void (WebKit::DrawingArea::*)(double, WebCore::FloatPoint, WTF::CompletionHandler<void ()>&&))


Possibly related to https://bugs.webkit.org/show_bug.cgi?id=250907. Tested on 309778@main with https://github.com/WebKit/WebKit/pull/61214 applied (otherwise is asserts way before reaching this).

[Sebastian Krzyszkowiak]

Seems easier to trigger with touchscreen than touchpad (but can happen with both).

[Sebastian Krzyszkowiak]

In release builds, this seems to lead to layers ending up at some bad offset (potentially being placed completely offscreen) until performing the gesture again.

[Claudio Saavedra]

*** This bug has been marked as a duplicate of bug 250907 ***