Unconventional score and unwanted stray staff lines

[David Bellows]

Hello everyone,

I tried to keep the examples minimal but I also needed to show the
full extent of what is going on.

Attached are two Lilypond files and pdfs showing an unconventional
score. Each part has the same number of notes but since the durations
are random, each part ends at its own time.

badtest.ly and badtest.pdf show the default behavior. When a part
ends, one of its staves continues on till the last part ends. I don't
want this behavior.

test.ly and test.pdf do a better job of showing what happens with the
workaround hack of adding s128 at the end of each part. The problem
with that -- and I didn't include examples -- is that if all the
durations are the same and end at a natural bar line, an extra empty
measure is added at the end of each part. I can't check for this
occurrence ahead of time in my own software as it would be insane to
keep track of all of that.

You'll notice a lot of context commands all of which I think are
necessary to get everything else to look as it should.

So I'm hoping someone has an idea about what's going on here and how
to prevent those extra staves like in test.pdf

Also, these Lilypond files are generated automatically by another
program I've created so the layout of the Lilypond file can't really
be changed without a massive amount of work. Hopefully a solution
won't require something like that.

badtest.pdf
Description: Adobe PDF document

test.pdf
Description: Adobe PDF document

badtest.ly
Description: Text Data

test.ly
Description: Text Data