I was recently digging to find if there is any special syntax accepted
for <oldbranch> in "git branch -m <oldbranch> <newbranch>" other than
the plain branch name. I discovered the @{-N} notation. I was trying to
play around with it and found that it didn't work as guaranteed by the
last sentence of the following paragraph in the "check-ref-format"
documentation,
With the --branch option, it expands the “previous branch syntax”
@{-n}. For example, @{-1} is a way to refer the last branch you were on.
This option should be used by porcelains to accept this syntax
anywhere a branch name is expected, so they can act as if you typed the
branch name.
In particular the following case doesn't work,
git init test &&
cd test &&
echo "Hello" >file &&
git add file &&
git commit -m "Initial commit that will be checked out" &&
echo "Hello world" >file &&
git commit file -m "Second commit" &&
git checkout HEAD^ &&
git checkout - &&
git branch -m @{-1} initial-commit
It failed with an error,
error: refname refs/heads/d21e72600673c670b3ae803488d0cebfa949e4c3 not found
fatal: Branch rename failed
Then I digged into why it didn't work to discover that @{-N} just
expands to a valid checkout and not a valid "branch name". So, the
documentation guaranteeing that "@{-N} acts as if you typed the branch
name" seems wrong. That makes me think that we should avoid misleading
the user in the "check-ref-format" documentation.
So, should we update the 'check-ref-format' doc or am I missing something?
---
Kaartic
