RESOLVED FIXED308452
[XML Parser] Perform microtask checkpoint before preparing script element 
https://bugs.webkit.org/show_bug.cgi?id=308452
Summary [XML Parser] Perform microtask checkpoint before preparing script element
soosungp33
Reported 2026-02-22 23:19:38 PST
The HTML spec [1] requires performing a microtask checkpoint before the "prepare the script element" step when an XML script element's end tag is parsed. Currently WebKit skips this checkpoint, so microtask callbacks queued during element insertion are not executed before script preparation. This causes the WPT test microtask_before_prepare_the_script_element-02.xhtml [2] to fail. Chromium is addressing the same issue: https://issues.chromium.org/issues/439639184 https://chromium-review.googlesource.com/c/chromium/src/+/7587954 [1] https://html.spec.whatwg.org/#parsing-xhtml-documents [2] https://wpt.fyi/results/html/webappapis/scripting/event-loops/microtask_before_prepare_the_script_element-02.xhtml?label=master&label=experimental&aligned
Attachments
Add attachment proposed patch, testcase, etc.
Ryosuke Niwa
Comment 1 2026-02-23 17:48:17 PST
https://github.com/WebKit/WebKit/pull/59228
EWS
Comment 2 2026-02-24 18:41:40 PST
Committed 308171@main (1e8516439d69): <https://commits.webkit.org/308171@main> Reviewed commits have been landed. Closing PR #59228 and removing active labels.
Radar WebKit Bug Importer
Comment 3 2026-02-24 18:42:13 PST
<rdar://problem/171130764>
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