- From: Sam Atkins via GitHub <noreply@w3.org>
- Date: Tue, 06 Jan 2026 15:53:45 +0000
- To: public-css-archive@w3.org
AtkinsSJ has just created a new issue for https://github.com/w3c/csswg-drafts: == [cssom-view] Ambiguous phrase "in a fixed position containing block" in offsetParent algorithm == In [`HTMLElement.offsetParent`](https://drafts.csswg.org/cssom-view-1/#dom-htmlelement-offsetparent) there are a couple of steps that refer to the element being "in a fixed position containing block" (or not), but "in" is ambiguous to me. I can think of a few different interpretations and it's not clear which is intended: 1. Its containing block is position: fixed. 2. Its containing block is a fixed position containing block. 3. Any ancestor establishes a fixed position containing block. (This seems redundant with the "and ancestor is a containing block for fixed-positioned descendants" part.) 4. Something else? I've interpreted it as number 3 and that seems to pass the relevant WPT tests, but it could easily be one of the others. Some clarification in the spec text would be appreciated. (Reposted from https://github.com/w3c/csswg-drafts/pull/12531/commits/48e905bb3859f80ce822299f7e6b76515d867fc3#r2623785087) Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/13302 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Tuesday, 6 January 2026 15:53:46 UTC