Re: bug - Inconsistency of git status and branch, ./git/branches and ./git/HEAD

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 30, 2023, 17:25 UTC
Message-ID: <xmqqcyxzfu8z.fsf@gitster.g>
In-Reply-To: <CAAcHogUEtcsFcDYp16g=154CMPh_a5fmY6ABEfp9zeqEJBNb6w@mail.gmail.com>

Irina Gulina <igulina@redhat.com> writes:

Show 8 quoted lines

>> What did you do before the bug happened? (Steps to reproduce your issue)
>> 1. create an empty directory in CLI: mkdir test_repo
>> 2. convert it to a git directory: cd test_repo & git init
>> 3. 'git status' will say you are "On branch master"
>> 4. 'git branch', 'git branch --all', or 'git branch --list' - nothing
>> will say the master branch exists. And per man pages definition the
>> branch command displays existing branches. So the question is why 'git
>> status' says "On branch master", but 'git branches' don't?

Chris gave a good answer to this most relevant question; let me fill in one gap with others.

>> 5. check on 'ls -la ./git/branches' - it's empty

The directory is where you would configure how individual local branches you have would behave, and it is expected to be empty if you did not do anything special.

>> 6. check on 'ls -la ./git/refs/heads' - it's empty

You can never expect the contents of .git/refs/* hierarchy to correspond to any state of the refs. If you have a history behind your local branch 'master', i.e., after running something like

    $ git init empty && cd empty && git commit --allow-empty -m init

you can "pack" the references, i.e.,

    $ git pack-refs --all

and all the necessary data for Git to know what your branches are and what commits they point at will be removed from .git/refs/* and stored in different place in .git/ hierarchy. So "there is no file at .git/refs/heads/master" does not mean "there is no master branch", even when we are not talking about a branch in the unborn state.

>> 7. check on 'cat ./git/HEAD' - it shows 'ref: refs/heads/master' -
>> why? if we didn't create any commit, and no branch exists?

The same comment applies to the above. If you want to know the state of HEAD, there are commands to do so ("git branch --list" being one of them). Do not expect that .git/HEAD would stay forever be the implementation detail of what the HEAD ref points at.