Beat structure after time signature change

[Vaughan McAlley]

Hi,

Setting the beat structure for beam subdivision seems to persist through
time signature changes. I think it would be preferable to reset everything
at a change of time signature, just like what happens to beamExceptions.

Cheers,
Vaughan

\version "2.20.0"

\score {
  \relative c' {
    \time 4/4
    c8 d16 e f32 e d c d e f g a8 b c4 |
    \bar "||"
    \time 9/8
    c,8^"Expected behaviour" d e e f g g a b |
    \bar "||"
    \break
    \time 4/4
    \set subdivideBeams = ##t
    \set baseMoment = #(ly:make-moment 1/8)
    \set beatStructure = 2,2,2,2
    c,8 d16 e f32 e d c d e f g a8 b c4 |
    \bar "||"
    % \time 3,3,3 9/8 doesn't work
    \time 9/8
    \set subdivideBeams = ##f % this makes no difference
    c,8^"???" d e e f g g a b |
    \bar "||"
    % This should be unnecessary
    \set baseMoment = #(ly:make-moment 1/8)
    \set beatStructure = 3,3,3
    c,8^"Better" d e e f g g a b |
    \bar "||"
  }
  \layout {}
}