Inconsistencies in trill alignment

[Ed Jackson]

Hello,

In the following, the "tr" trill symbol is aligned differently in
various situations.  The trill with no spanner is centered nicely
above the note, as is the trill with the spanner created using the
TextSpanner.  However, the two trills which are created with
\startTrillSpan and \stopTrillSpan have the "tr" glyph offset to the
left, and the start of the spanner is centered above the note.  It
seems to me that the default behavior should be to keep the glyph
centered.

Thanks!

  -Ed


\version "2.3.13"
                                                                                
\relative \notes {
  c'4 c2\trill c4
  | c2\startTrillSpan c2\stopTrillSpan
  | c2 << {s4..\startTrillSpan s16\stopTrillSpan} \\ c2 >>
  | \override TextSpanner #'style = #'trill
    \override TextSpanner #'edge-text = #(cons (make-musicglyph-markup
"scripts-trill") "")
    c2\startTextSpan c2\stopTextSpan
}