Git *accepts* a branch name, it can't identity in the future?

Hello all,

First of all, I would like to tell that this happened completely by accident and it's partly my mistake. Here's what happened.

I recently started creating 'feature branches' a lot for the few patches that I sent to this mailing list. To identify the status of the patch corresponding to that branch I prefixed them with special unicode characters like ✓, ˅ etc. instead of using conventional hierarchical names like, 'done/', 'archived/'.

Then I started finding it difficult to distinguish these unicode- prefixed names probably because they had only one unicode character in common. So, I thought of switching to the conventional way of using scoped branch names (old is gold, you see). I wrote a tiny script to rename the branches by replacing a specific unicode prefix with a corresponding hierachy. For example, the script would convert a branch named '✓doc-fix' to 'done/doc-fix'.

I made a small assumption in the script which turned out to be false. I thought the unicode prefixes I used corresponded to only two bytes. This lead to the issue. The unicode character '✓' corresponds to three characters and as a result instead of removing it, my script replaced it with the unknown character '�'. So, the branch named '✓doc-fix' became 'done/�doc-fix'. Here's the issue. I couldn't use 

    $ git branch -m done/�doc-fix done/dic-fix 

to rename the branch. Nor could I refer to it in anyway. Git simply says,

    error: pathspec 'done/�doc-fix' did not match any file(s) known to git.

It's not a big issue as I haven't lost anything out of it. The branches have been merged into 'master'.

I just wanted to know why git accepted a branch name which it can't identify later?

If it had rejected that name in the first place it would have been better. In case you would like to know how I got that weird name, here's a way to get that

    $ echo '✓doc-fix' | cut -c3-100