Wikimedia Bugzilla is closed!

*** Bug 51388 has been marked as a duplicate of this bug. ***

*** Bug 53346 has been marked as a duplicate of this bug. ***

Confirmed. I tested the following code on Google Chrome console

mw.loader.using( 'mediawiki.jqueryMsg', function(){
  mw.messages.set( {
    bug47395a: '[[$1|Text]]',
    bug47395b: '[[link|$1]]'
  } );
  alert(
    mw.message( 'bug47395a', 'ABC' ).plain() + ': ' +
    mw.message( 'bug47395a', 'ABC' ).parse() + '\n' +
    mw.message( 'bug47395b', 'ABC' ).plain() + ': ' +
    mw.message( 'bug47395b', 'ABC' ).parse()
  );
} );

and got the following message on Portuguese Wikipedia:

[[ABC|Text]]: bug47395a: Parse error at position 0 in input: [[$1|Text]]
[[link|ABC]]: <a title="link" href="/wiki/link">ABC</a>

*** Bug 58961 has been marked as a duplicate of this bug. ***

For anyone interested, you can workaround this until this is fixed:

mw.loader.using( 'mediawiki.jqueryMsg', function () {

    mw.messages.set( {
        foo: '[[$1]]'
    } );

    var msg = mw.message( 'foo', 'bar' ).plain();
    // [[bar]]

    mw.messages.set( {
        'some-random-message': msg
    } );

    msg = mw.message( 'some-random-message' ).parse();
    // <a title="bar" href="/wiki/bar">bar</a>

    console.log( msg );

} );