unexpected behavior using \halign

[Tapio Tuovila]

Hi,

I happened to notice following behavior:

if you increase \halign from -0.5 to -0.6 the vertical placement of the
text changes considerably; more than the horizontal one. But halign
should only set horizontal alignment. Can anyone explain what happens here?

\version "2.7.37"
 
        \relative c'' {
       
        \override TextScript   #'extra-offset = #'(0 . 3)
        c16( d^\markup {\italic \halign # -0.5 "meno mosso"} f a) b8.(->
a16)
        }