Nguyễn Thái Ngọc Duy  [off-list ref] writes:

The recent assume-unchanged "breakage" that lets Git overwrite
assume-unchanged files worried me. I sat back, checked and wrote tests

Yeah, it worries me, too.  Does the fix to make sure the sparse stuff
won't be broken apply equally to assume-unchanged?  Does the series have
such fixes to assume-unchanged bit as well?

By the way, I think the first patch in the earlier series, 540e694
(Prevent diff machinery from examining assume-unchanged entries on
worktree, 2009-08-11), is a good change regardless of the sparse
implementation, and I'm inclined to say that we should merge that part
(and I suspect there will be similar fixes to really ignore differences to
CE_VALID entries) first and then queue this new series on top.