pub fn branch_base_sha(branch: &str) -> Option<String>Expand description
Read the recorded base tip SHA for a branch (branch.<name>.gwBaseSha).
Recorded by gw new --stack as the parent’s HEAD at stack time. Serves as a
git rebase --onto boundary that survives even if the base branch ref is
later deleted (e.g. cleaned up after its PR merged). None when unset.