Git references separated by slashes

This article documents a quick investigation on why we cannot have git references with slashes who's parts are parts of another reference.

This is a bit difficult to explain so I'll illustrate the use case by example:

git init
git switch -c foo/bar
git commit --message 'foo/bar' --allow-empty
git switch -c foo # this will not work!

# vice-versa
git init
git switch -c foo
git commit --message 'foo' --allow-empty
git switch -c foo/bar # this will not work!

A git reference's sha is stored in .git/refs/heads/.

For example, the commit with the message foo/bar has a sha b855e5727081283951c786cf72669cb6bde385e2, which is printed in the .git/refs/heads/foo/bar file.

Each parent part of the slash separated reference is a directory. In Linux, we cannot have both a directory and a file named the same. As a result, the reference foo is unavailable.