Matthieu Moy [off-list ref] writes:
And you miss the most usefull (to me at least): "choose the version in
the worktree".
I tend to think that "add -p" whose sole purpose is to make partial commit
is fundamentally incompatible with "am", "merge" and (mostly) "rebase",
which you do not want to record partial commit.
When "rebase -i" or "cherry-pick" that is used for the purpose of
replaying only a part of a larger commit, letting "add -p" show the
difference between "HEAD" and the working tree version, and letting the
user pick hunks, would make a lot of sense, though.
For such an application, however, the user could first "reset $path" and
use "add -p" normally.