With the [[ https://gerrit.wikimedia.org/r/c/mediawiki/core/+/464607 | latest change to v0.29.1 ]] the MenuSelectWidget seems to have lost (parts of) its `onKeyDown` handling, the "escape" key does not close the suggestion menu as before.
This behavior can be reproduced on the [[ https://doc.wikimedia.org/oojs-ui/master/demos/?page=widgets&theme=wikimediaui&direction=ltr&platform=desktop#demo-section-comboBox | demo page ]]. Typing any value, e.g. "asd" in the ComboBoxInputWidget field (selects the first value), then hitting escape - this does not close the menu as observed in earlier versions (e.g. v0.28.2).
The defective code is not immediately obvious to me but may have been introduced during https://gerrit.wikimedia.org/r/c/oojs/ui/+/437960
Background: We first experienced this in a browser test for WikibaseLexeme on [[ https://wikidata.beta.wmflabs.org/w/index.php?title=Special:NewLexeme | Special:NewLexeme ]] when specifying a fallback lemma language (initially hidden), worked around it by not using escape any more https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Wikibase/+/464786