Shorten TextSpanner dashed line

[Davide Liessi]

Hi all.
Is it possible to automatically shorten the dashed line in
TextSpanners so that the line of the first TextSpanner ends before the
left text of the second TextSpanner (and thus the two TextSpanners can
align vertically)?

\version "2.19.82"
{
  \override TextSpanner.bound-details.left.text = "test"
  b1\startTextSpan
  b1\stopTextSpan\startTextSpan
  b1\stopTextSpan
}

In alternative, is it possible to shorten the TextSpanners' X-extent
by the appropriate amount?

Best wishes.
Davide