• Fixed spurious window blur and focusout events and incorrect event.relatedTarget values when focusing an element after removing the previously focused element, which regressed in v30.1.0. (@asamuzaK)
• Fixed focus and blur behavior across frames, and focusing the document's viewport through document.documentElement.focus(). (@asamuzaK)
• Fixed focus targets removed or disabled by blur listeners becoming active, and text selections made by focus and blur listeners being overwritten. (@asamuzaK)
• Fixed element.focus() incorrectly focusing disabled form controls and <input type="hidden"> elements with tabindex="". (@scttcper)
• Fixed invalid style.setProperty() calls changing existing !important priorities, serialized styles, or mutation records. (@FedgeNo)
• Fixed !important handling when updating CSS longhands after shorthands, using variables or CSS-wide keywords, and assigning style properties directly. (@FedgeNo)
• Fixed <noscript> parsing with includeNodeLocations: true or inside frames to honor the runScripts option.
• Fixed the storageQuota option being ignored by frames.
• Fixed encoding detection of HTML and XML byte input to honor XML encoding declarations and detect UTF-16 without a byte order mark.
• Fixed exceptions caused by truncated charset parameters in <meta> elements, and encoding detection incorrectly using incomplete <meta> tags. (@FedgeNo)
• Fixed XML serialization errors for namespaces named constructor, toString, __proto__, or "null", and incorrect reuse of namespace prefixes declared on sibling elements.
• Fixed element.innerHTML and element.outerHTML in XML documents to reject invalid characters in attribute values and avoid stack overflows on large strings.
• Fixed selector matching for :lang(), :nth-child(... of ...) after mutations, and :has() with duplicate IDs or nested logical pseudo-classes. (@asamuzaK)