[PATCH v3 2/2] Doc/check-ref-format: clarify information about @{-N} syntax
- From
Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
- Date
- Nov 28, 2017, 16:34 UTC
- Message-ID
- <20171128163406.15452-1-kaartic.sivaraam@gmail.com>
- In-Reply-To
- <xmqqd14386sw.fsf@gitster.mtv.corp.google.com>
When the N-th previous thing checked out syntax (@{-N}) is used with '--branch' option of check-ref-format the result might not always be a valid branch name (see NOTE below). This is because @{-N} is used to refer to the N-th last checked out "thing" which might be any commit (sometimes a branch). The documentation thus does a wrong thing by promoting it as the "previous branch syntax".
So, correctly state @{-N} is the syntax for specifying "N-th last thing checked out" and also state that the result of using @{-N} might also result in a "commit hash".
NOTE: Though a commit-hash is a "syntactically" valid branch name,
it is generally not considered as one for the use cases of
"git check-ref-format --branch". That's because a user who does
"git check-ref-format --branch @{-$N}" would except the output
to be a "existing" branch name apart from it being syntactically
valid.Signed-off-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com> --- Documentation/git-check-ref-format.txt | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/Documentation/git-check-ref-format.txt b/Documentation/git-check-ref-format.txt index cf0a0b7df..5ddb562d0 100644 --- a/Documentation/git-check-ref-format.txt +++ b/Documentation/git-check-ref-format.txt @@ -78,17 +78,20 @@ reference name expressions (see linkgit:gitrevisions[7]): . at-open-brace `@{` is used as a notation to access a reflog entry. With the `--branch` option, the command takes a name and checks if -it can be used as a valid branch name (e.g. when creating a new -branch). The rule `git check-ref-format --branch $name` implements +it can be used as a valid branch name e.g. when creating a new branch +(except for one exception related to the previous checkout syntax +noted below). The rule `git check-ref-format --branch $name` implements may be stricter than what `git check-ref-format refs/heads/$name` says (e.g. a dash may appear at the beginning of a ref component, but it is explicitly forbidden at the beginning of a branch name). When run with `--branch` option in a repository, the input is first -expanded for 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. +expanded for the ``previous checkout syntax'' +`@{-n}`. For example, `@{-1}` is a way to refer the last thing that +was checkout using "git checkout" operation. 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. As an +exception note that, the ``previous checkout operation'' might result +in a commit hash when the N-th last thing checked out was not a branch. OPTIONS ------- @@ -116,7 +119,7 @@ OPTIONS EXAMPLES -------- -* Print the name of the previous branch: +* Print the name of the previous thing checked out: + ------------ $ git check-ref-format --branch @{-1}
-- 2.15.0.531.g2ccb3012c