Hash :
95b7a639
Author :
Date :
2021-04-14T21:52:36
git_reference_create_matching: Treat all-zero OID as "must be absent"
This is pretty useful in avoiding races: I want to create a ref only if
it doesn't already exist. I can't check first because of TOCTOU -- by
the time I finish the check, someone else might have already created
the ref. And I can't take a lock because then I can't do the create,
since the create expects to take the lock.
The semantics are inspired by git update-ref, which allows an all-zero old
value to mean that the ref must not exist.