Bug 198532 – Sticky positioning is jumpy in many overflow cases

• Status: RESOLVED
• Resolution: FIXED
• Component: Scrolling

[Antti Koivisto]

We need to compute offsets correctly.

[Radar WebKit Bug Importer]

<rdar://problem/51400532>

[Antti Koivisto]

Created attachment 371290 [details]
patch

[Simon Fraser (smfr)]

Comment on attachment 371290 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=371290&action=review

> Source/WebCore/page/scrolling/cocoa/ScrollingTreeStickyNode.mm:89
> +                    auto overflowNode = scrollingTree().nodeForID(positioningAncestor.relatedOverflowScrollingNodes()[0]);

Are you guaranteed to have positioningAncestor.relatedOverflowScrollingNodes ?

[EWS Watchlist]

Comment on attachment 371290 [details]
patch

Attachment 371290 [details] did not pass mac-wk2-ews (mac-wk2):
Output: https://webkit-queues.webkit.org/results/12374500

New failing tests:
scrollingcoordinator/mac/nested-sticky.html

[EWS Watchlist]

Created attachment 371298 [details]
Archive of layout-test-results from ews104 for mac-highsierra-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews104  Port: mac-highsierra-wk2  Platform: Mac OS X 10.13.6

[Simon Fraser (smfr)]

Comment on attachment 371290 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=371290&action=review

> Source/WebCore/page/scrolling/cocoa/ScrollingTreeStickyNode.mm:83
> +        for (auto* ancestor = parent(); ancestor; ancestor = ancestor->parent()) {

Also, shame this is making the tree walk O(n^2)

[Antti Koivisto]

> Are you guaranteed to have positioningAncestor.relatedOverflowScrollingNodes
> ?

I don't think we ever construct these without. It wouldn't make much sense.

[Antti Koivisto]

Created attachment 371314 [details]
patch

[WebKit Commit Bot]

Comment on attachment 371314 [details]
patch

Clearing flags on attachment: 371314

Committed r246083: <https://trac.webkit.org/changeset/246083>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Simon Fraser (smfr)]

*** Bug 196724 has been marked as a duplicate of this bug. ***