Struct BranchCommitRefUpdate 

pub struct BranchCommitRefUpdate<'a> {
    pub branch_ref: &'a str,
    pub expected_old: Option<ObjectId>,
    pub new_oid: ObjectId,
    pub identity: &'a str,
    pub reflog_message: &'a str,
}

Move a checked-out branch to new_oid and append matching branch and HEAD reflogs.

Verifies HEAD is a symbolic ref to branch_ref, then runs a storage transaction: on the files backend the branch ref lock is held from CAS through reflog writes and ref commit; on reftable, branch and HEAD logs are written in one transaction. Reflog failures before the ref commit do not advance the branch tip.

Errors

Returns Error::Message when HEAD does not point at branch_ref, store::RefStoreError::ExpectedMismatch (see verify_branch_commit_cas) when the CAS check fails, or an I/O error when ref/reflog writes fail.

Fields

branch_ref: &'a str

Branch ref to update (e.g. refs/heads/main).

expected_old: Option<ObjectId>

Expected current tip; None when the branch must not exist yet (unborn).

new_oid: ObjectId

New commit OID for the branch tip.

identity: &'a str

Committer identity for reflog lines.

reflog_message: &'a str

Reflog message (without trailing newline).