Validate if commit exists

Question

How to validate whether the commit with given sha exists in current branch?

There are many ways to parse outputs, but I need optimal way which returns boolean (for u

Answer 1

git merge-base --is-ancestor $sha HEAD

---

This tests if $sha is an ancestor commit for the current branch (HEAD), and exits successfully if it is.

In your example,

sha=$1
if ! git merge-base --is-ancestor $sha HEAD; then
  echo "Invalid commit sha: $sha"
  exit 1
fi