Comment #6 on issue 2820 by [email protected]: Tab staff repeat sign http://code.google.com/p/lilypond/issues/detail?id=2820
I've played a bit with other settings but didn't find those better.some of the repeat-sign.ly tests change for the worse, e.g. those that use the same spacing as a default tab staff, so I saw no point in trying to defend them.
