Bug 235930 – Blank page when removing CSS @import

• Component: CSS
• Status: RESOLVED FIXED

[Oriol Brufau]

Run the script from bug 235434:

```html
You should see this text!!!
<script>
const style = document.createElement("style");
document.head.append(style);

style.sheet.insertRule('@import url("nonexist.css")');
style.sheet.cssRules[0];
style.sheet.deleteRule(0);
</script>
```

Actual: completely blank page

Expected: page with "You should see this text!!!"

Reason: the import rule is removed before it finishes loading, and the hasPendingSheet() flag is not cleared.

[Oriol Brufau]

Created attachment 450478 [details]
Patch

[EWS Watchlist]

This patch modifies the imported WPT tests. Please ensure that any changes on the tests (not coming from a WPT import) are exported to WPT. Please see https://trac.webkit.org/wiki/WPTExportProcess

[Antti Koivisto]

Comment on attachment 450478 [details]
Patch

looks like the debug bot is hitting assert under StyleRuleImport::cancelLoad

[Antti Koivisto]

in imported/w3c/web-platform-tests/css/cssom/cssimportrule-parent.html sonf inspector/css/stylesheet-events-imports.html

[Oriol Brufau]

Created attachment 450515 [details]
Patch

[Oriol Brufau]

Should work now. It's just that cancelLoad() shouldn't do anything if it had already loaded.

[Antti Koivisto]

Comment on attachment 450515 [details]
Patch

Good find, thanks!

[Radar WebKit Bug Importer]

<rdar://problem/88322836>

[EWS]

Committed r288879 (246631@main): <https://commits.webkit.org/246631@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 450515 [details].