Bug 239357

Summary:	Element with "position: sticky" doesn't stick if parent element has "contain: paint"
Product:	WebKit	Reporter:	Daniel Lu <danilu>
Component:	CSS	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED DUPLICATE
Severity:	Minor	CC:	simon.fraser
Priority:	P2
Version:	Safari 15
Hardware:	Mac (Intel)
OS:	macOS 12

Description Daniel Lu 2022-04-14 15:43:53 PDT

Reproduction Steps:
1. Go to https://codepen.io/dl1644/pen/zYpmLpd in Safari 15.4 (macOS 12.3.1)
2. Attempt to scroll the green/yellow/red div to the right
3. Note that the green "sticky" div is scrolled out of view
4. Repeat steps 1 and 2 in Chrome(100) and Firefox (99). Note that the green "sticky" div stays in view
5. Return to your Safari codepen tab and remove "contain: paint" from the "#row" CSS
6. Attempt to scroll the green/yellow/red div. Note that the green "sticky" div stays in view now but the yellow "float" div now spills out the bottom of the red div


Started occurring with Safari 15.4 from what I can tell. Unsure if this counts as a regression since "contains" is newly supported in Safari 15.4 but the sticky behavior worked just fine in at least Safari 14 and below.

Comment 1 Simon Fraser (smfr) 2022-04-14 19:29:06 PDT


*** This bug has been marked as a duplicate of bug 238016 ***