Bug 191865 - [css-scroll-snap] scroll-snap-align parsing is incorrect/backwards
Summary: [css-scroll-snap] scroll-snap-align parsing is incorrect/backwards
Alias: None
Product: WebKit
Classification: Unclassified
Component: CSS (show other bugs)
Version: Safari 12
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Martin Robinson
Keywords: BrowserCompat, InRadar
Depends on:
Blocks: 218115
  Show dependency treegraph
Reported: 2018-11-20 12:58 PST by Majid Valipour
Modified: 2021-01-14 03:02 PST (History)
11 users (show)

See Also:

Patch (12.43 KB, patch)
2021-01-13 08:47 PST, Martin Robinson
no flags Details | Formatted Diff | Diff
Patch (14.54 KB, patch)
2021-01-14 01:37 PST, Martin Robinson
no flags Details | Formatted Diff | Diff

Note You need to log in before you can comment on or make changes to this bug.
Description Majid Valipour 2018-11-20 12:58:58 PST
CSSWG has resolved [1] to change the ordering of scroll-snap-align property to be in "block inline" order. WebKit parsing logic appear to do "inline, block" order.
I have changed Chromium implementation to match the specification but it is now different from Safari.
The current usage of two value is low but as it grows the interop issue problem grows.

Additional links:
- My backward compat analysis suggested the risk is low [2]
- Relevant WPT test [3].

I tested this on Safari 12.0.1.

[1] https://github.com/w3c/csswg-drafts/issues/2232
[2] https://github.com/w3c/csswg-drafts/issues/2232#issuecomment-399961633
[3] https://wpt.fyi/results/css/css-scroll-snap/snap-inline-block.html?label=stable&aligned
Comment 1 Radar WebKit Bug Importer 2018-11-29 10:35:08 PST
Comment 2 Martin Robinson 2021-01-13 08:47:11 PST
Created attachment 417539 [details]
Comment 3 Simon Fraser (smfr) 2021-01-13 09:42:35 PST
Comment on attachment 417539 [details]

Please fix the failing test.
Comment 4 Martin Robinson 2021-01-14 01:37:47 PST
Created attachment 417604 [details]
Comment 5 EWS 2021-01-14 03:02:47 PST
Committed r271480: <https://trac.webkit.org/changeset/271480>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 417604 [details].