Possible bug with TrillSpanner.to-barline?

[Daniel Rosen]

In the example below, uncommenting the indicated line results in the 
TrillSpanner only printing the wavy line without the "tr." Is this a bug?

\version "2.17.97"

trillSharpMarkup = \markup {
  \concat { \musicglyph #"scripts.trill" \hspace #0.4 \raise #1.9 \teeny \sharp 
}
}

trillspanSharp = { \override TrillSpanner.bound-details.left.text = 
\trillSharpMarkup }

trillspanNormal = \revert TrillSpanner.bound-details

\relative c' {
  %% Uncomment next line
  %\override TrillSpanner.to-barline = ##t
  \trillspanSharp c1\startTrillSpan |
  \trillspanNormal c1\stopTrillSpan\startTrillSpan |
}

DR