No warning is shown when previewing a "sanitized-css" page containing unsupported CSS
Closed, ResolvedPublicBUG REPORT
Actions

Assigned To

None

Authored By

	Od1n
	May 7 2023, 4:54 AM

Description

Follow-up to T217722.

How to reproduce:

Start editing a page that has "sanitized-css" content model (example of page).
Add some unsupported CSS (for example :is(.foobar) selector).
Do "Show preview" or "Show changes".

Expected: A warning is supposed to be shown, pointing out the unsupported CSS. (The warning from the right picture of T266157#7450639, below the preview note.)

Current: No warning is shown.

(Though, when doing "Publish changes", the publishing is prevented and a warning pointing out the unsupported CSS is shown, as expected.)

What I tried, without success:

Setting the interface language to English, to avoid using the custom MediaWiki:Previewnote.
Disabling the Live preview feature ("Show preview without reloading the page").

Related Objects

Mentioned Here: T190120: Parse warnings not visible with live preview
T266157: CSS error should be displayed while trying to save, not only when previewing
T217722: Support (part of?) Selectors level 4 in css-sanitizer

Event Timeline

Od1n created this task.May 7 2023, 4:54 AM

Restricted Application added a subscriber: Aklapper. · View Herald TranscriptMay 7 2023, 4:54 AM

Od1n updated the task description. (Show Details)May 7 2023, 5:00 AM

This worked in the past (also with live preview, that was T190120).

I can see a preview warning for invalid JSON, so the error seems specific to TemplateStyles.

I don't understand how it could have ever worked in production. The only thing that adds warnings is TemplateStylesContentHandler::fillParserOutput(), but SyntaxHighlight's ContentGetParserOutput hook returns false, so fillParserOutput() is never called. SyntaxHighlight parses the content as wikitext, calling Parser::parse() directly. This all appears to have been the case in 2021 so I don't understand how it could have worked back then.

This appears to have been fixed. SyntaxHighlight was recently changed to use the ContentAlterParserOutput hook instead of ContentGetParserOutput. I'm guessing that's why.

Screenshot 2025-05-24 at 11.50.15 PM.png (844×1 px, 110 KB)

Looks like this is fixed now—turns out the change in SyntaxHighlight’s hook did the trick. Thanks to everyone who helped look into this! Closing the ticket.

	F60466613: Screenshot 2025-05-24 at 11.50.15 PM.png
	May 24 2025, 6:25 PM

No warning is shown when previewing a "sanitized-css" page containing unsupported CSSClosed, ResolvedPublicBUG REPORTActions

Description

Related Objects

Event Timeline

No warning is shown when previewing a "sanitized-css" page containing unsupported CSS
Closed, ResolvedPublicBUG REPORT
Actions