[drostie]

I'm not quite so familiar with the Git internals, how do you deal with the problem of having different non-leaf nodes scattered through the directory tree?

This might be a non-issue based on how Git stores the tree, but I can imagine one simple model where each directory would be a sort of "collection object", a binary encoding of a list of (filename, hash) pairs in filename order, and therefore the directory gets a hash of its own. But that means that when you're communicating with a SHA-1 repository you don't just need to rename this object; its contents also need to be changed pre-rename, and then you need to store every internal node twice. I'm not seeing that in your summary.

Is it just that Git doesn't have any internal nodes in the directory tree per se because the "filename" is a full POSIX path with subdirs? Or what?

[evmar]

https://git-scm.com/book/en/v2/Git-Internals-Git-Objects has descriptions of the objects. Both trees and commits are hashes over data that includes hashes of other objects so they must be different. The doc discusses converting them at transmission time, search for [convert to sha256] in it.