TextSpanner line styles broken in 2.12.2?

[Don Benson]

I'm trying to generate a dashed-line text spanner, but lilypond is generating a truncated solid line instead.

Sample of my initial attempt:
\relative c''
{
\override TextSpanner #'style = #'dashed-line
\override TextSpanner #'(bound-details left text) = \markup { \italic "rit." }
\textSpannerDown
f16-. \startTextSpan e-. f-. g,-. a-. b-. c!-. d-.
e4-> r16 g,-. a-. b-. \stopTextSpan
}

This produces a solid line that covers about half of the span. The style dotted-line does the same thing. 

If I change the style to line, trill, or zigzag, the line goes the entire length of the bar, as expected. I can get the dashed/dotted line to extend by overriding dash-period to 8.0 or higher, but it is still a solid line.

Am I doing something wrong, or is something broken in 2.12.2?

If environment matters, I'm running on Windows Vista SP1.

Sincerely,
- Don Benson -