xml2ly: Invalid ligature bracket syntax emitted

[lemzwerg]

[ef5018a]

Consider the MusicXML file in the attached archive and process it with

xml2ly ligature-bracket.xml > ligature-bracket.ly

xml2ly emits the ligature bracket in an incorrect way, using \[ before and after the note (which causes a LilyPond warning):

\[ b'4 \[ b' b' \]  | % 3

Instead, it should emit \[ only before the note:

\[ b'4 b' b' \]  | % 3

ligature-bracket.zip