Scrolling to fragment shouldn't happen as a part of updating style

[Ryosuke Niwa]

Document::resolveStyle sometimes frameView.scrollToFragment
when there were pending stylesheets inside FrameView::scrollToAnchor,
which is called by FrameLoader::scrollToFragmentWithParentBoundary.

[Ryosuke Niwa]

Created attachment 383686 [details]
WIP1

[Simon Fraser (smfr)]

Comment on attachment 383686 [details]
WIP1

View in context: https://bugs.webkit.org/attachment.cgi?id=383686&action=review

> Source/WebCore/dom/Document.cpp:3476
> +    if (m_gotoAnchorNeededAfterStylesheetsLoad) {
> +        // https://html.spec.whatwg.org/multipage/browsing-the-web.html#try-to-scroll-to-the-fragment
> +        eventLoop().queueTask(TaskSource::Networking, *this, [this] {
> +            if (!m_renderView)
> +                return;
> +            m_renderView->frameView().scrollToFragment(m_url);
> +        });
> +    }

Shouldn't this be in the "run the scrolling steps" part of the event loop?

[Ryosuke Niwa]

(In reply to Simon Fraser (smfr) from comment #2)
> Comment on attachment 383686 [details]
> WIP1
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=383686&action=review
> 
> > Source/WebCore/dom/Document.cpp:3476
> > +    if (m_gotoAnchorNeededAfterStylesheetsLoad) {
> > +        // https://html.spec.whatwg.org/multipage/browsing-the-web.html#try-to-scroll-to-the-fragment
> > +        eventLoop().queueTask(TaskSource::Networking, *this, [this] {
> > +            if (!m_renderView)
> > +                return;
> > +            m_renderView->frameView().scrollToFragment(m_url);
> > +        });
> > +    }
> 
> Shouldn't this be in the "run the scrolling steps" part of the event loop?

Nope: https://html.spec.whatwg.org/multipage/browsing-the-web.html#scroll-to-the-fragment-identifier
which triggers:
https://drafts.csswg.org/cssom-view/#perform-a-scroll
just scrolls it.

There is a separate section about what scrolling step does but that doesn't include the actual scrolling:
https://drafts.csswg.org/cssom-view/#scrolling-events

[Ryosuke Niwa]

Created attachment 384110 [details]
Patch

[Ryosuke Niwa]

Created attachment 384114 [details]
Patch

[Ryosuke Niwa]

Committed r252761: <https://trac.webkit.org/changeset/252761>

[Radar WebKit Bug Importer]

<rdar://problem/57418860>

[Antti Koivisto]

Comment on attachment 384114 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=384114&action=review

> Source/WebCore/dom/Document.cpp:-2006
> -    if (m_gotoAnchorNeededAfterStylesheetsLoad && !styleScope().hasPendingSheets())
> -        frameView.scrollToFragment(m_url);

You should also remove this code from Document::needsStyleRecalc()

    // Ensure this happens eventually as it is currently in resolveStyle. This can be removed if the code moves.
    if (m_gotoAnchorNeededAfterStylesheetsLoad && !styleScope().hasPendingSheets())
        return true;