Cross-nesting \repeat segno and \repeat volta

[Huanyu Liu]

Hi,

I am trying to write something tricky (but not rare, in my opinion) with both 
`\repeat segno` and `\repeat volta`. Here is an illustration of what I want to 
achieve:

A   ||:   B   |(Segno)   C   |(Coda)(Volta 1 start)   D1   (Volta 1 end):||
(Volta 2 start)   D2   (Volta 2 end)(DS)||(Coda)   D3   ||

The order should be A-B-C-D1-B-C-D2-C-D3.

The attached code is really close to my desired output, but the closing repeat 
bar line is printed at the end, instead of the end of Volta 1. I think this is 
because the inner layer of `\alternative` should have paired the outer layer 
of `\repeat volta` (which I call "cross-nesting"), but since there is an outer 
layer of `\alternative` between them, the inner layer of `\alternative` is not 
recognized by `\repeat volta`.

So how can I achieve that without manual placement of all those signs? Or is 
there any better method instead of using nested `\repeat segno  ` and `\repeat 
volta`?

Thanks!
Huanyu
\version "2.25.4"
\relative {
  a1 | % A
  \repeat volta 2 {
    b1 | % B
    \repeat segno 2 {
      c1 | % C
      \alternative {
        \volta 1 {
          \alternative {
            \volta 1 {
              d1 | % D1
            }
            \volta 2 {
              d2 d2 | % D2
            }
          }
        }
        \volta 2 {
          \section
          d4 d4 d4 d4 | % D3
        }
      }
    }
  }
}