Mozilla Firefox は、SVG 要素に xml:base 属性が指定されている場合、SVG ドキュメント内の xlink:href 属性のローカル IRI 参照を認識しません。
同じ SVG ドキュメントが Google Chrome で正常に表示されます。
xml:base 属性を削除しようとすると、Firefox はローカル ID で要素を見つけます。
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