1\version "2.20.0"
2
3\header {
4  texidoc = "The @code{Melody_engraver} decides stem direction for
5notes on the middle staff line based on neighboring notes.
6Mid-measure repeat bar lines break up the melody as do normal measure
7bar lines.  In this test, marcato marks show the expected stem
8direction."
9}
10
11\new Voice \with {
12  \consists "Melody_engraver"
13  \override Stem.neutral-direction = #'()
14} \relative c'' {
15  a2 \repeat volta 2 { b4_^ c | c2 } b4^^ a
16}
17