wikimedia/mediawiki-extensions-Translate

( function () {
    'use strict';

    /**
     * Overrides the mw.uls.changeLanguage present in ULS
     *
     * @internal
     * @param {string} language
     */
    mw.uls.changeLanguage = function ( language ) {
        var page = 'Special:MyLanguage/' + mw.config.get( 'wgPageName' );

        if ( mw.config.get( 'wgTranslatePageTranslation' ) === 'translation' ) {
            page = page.replace( /\/[^/]+$/, '' );
        }

        mw.uls.setLanguage( language ).then( function () {
            location.href = mw.util.getUrl( page );
        } );
    };
}() );