Victoria Dye [off-list ref] writes:
This test failure is a result of a behavior change in the logging of 'git
rm' in this series when removing a sparse directory. Patch 4 talks about it
in more detail [1]; I failed to account for it in my series.
Ah, OK. When a directory being "git rm"'ed is outside the cone(s)
of our interest, it indeed does feel like a waste to expand the
index only to report which paths in that directory are being
removed. It would be OK for the behaviour to be different inside
and outside the cone(s).