What you describe changes the name from "index" to "WIP commit", keeping the same semantics. Along the way, you now have a "commit" that doesn't behave like a commit, further adding to the potential for confusion. I strongly believe that things that behave differently should be named differently.
> What you describe changes the name from "index" to "WIP commit", keeping the same semantics.
I.e. you get it.
Importantly, the semantics is available through a common interface rather than a different design and implementation of the semantics for the index versus commits.
> you now have a "commit" that doesn't behave like a commit
Well, now; literally now you have a commit that doesn't behave like a commit: the index.
If a real commit is used for staging, it behaves much more like a commit. It's just attributed as do-not-publish so it doesn't get pushed out. Under this model, all commits have this attribute; it's just false for most of them. Thus, it isn't a different kind of commit.
> I strongly believe that things that behave differently should be named differently.
Things that do not behave completely differently can use qualified names, in situations when it matters:
"work-in-progress commit; tentative commit; ...."
For instance we use "socket" for both TCP and UDP communication handles, or both Internet and Unix local ones.
