You are again talking about a fictional alternate reality in which git commit signatures do something like GPG_Sign(GPG_Signature_Hash(git commit || all objects referenced by commit))), instead of ours where it's GPG_Sign(GPG_Signature_Hash(git commit))), and the git commit is in turn some metadata and a git hash of a bunch of objects.

In our reality, the git hash is load bearing. You can disagree with that design choice, but you can't pretend to live in that alternate reality and design your solutions for this reality according to that.

> You are again talking about a fictional alternate reality

> can't pretend to live in that alternate reality

Discussions about solutions that don't exist or requirements not implemented are everyday occurrences and necessary.

I mean, if you're talking with a contractor about how your bathroom should look, that is a "fictional alternate reality", but you're not pretending to be living in it now.

I don't understand the purpose of the above engagement style, but it doesn't look like a great fit for HackerNews.

There's a difference between talking about a hypothetical path forward and a hypothetical different past. The latter can be intellectually interesting but is rarely part of normal project planning.

[delayed]

As far as git is concerned, GPG is a black box and git feeds it normal git hashes, of which there is only one kind. This design makes sense.

For anything else, it depends on the exact scheme:

If git sent GPG the bits for the current commit specifically because it expects a better hash to be used, that would be silly to design on purpose (git should use a hash that meets all requirements). And it wouldn't protect history, which matters.

If git rounded up the bits of history, that would perform unacceptably badly.

If git used a better hash to secure history for signing purposes, and still had the normal hash elsewhere, that would be very silly to design on purpose because it should use the better hash for everything.