The appropriate number of bytes for the given object ID type will
be read from the string - 40 bytes for SHA1, 64 bytes for SHA256.
The given string need not be null terminated.
input hex string; must be pointing at the start of the hex sequence and have at least the number of bytes needed for an oid encoded in hex (40 bytes for sha1, 256 bytes for sha256).
Parse a hex formatted object id into a git_oid.
The appropriate number of bytes for the given object ID type will be read from the string - 40 bytes for SHA1, 64 bytes for SHA256. The given string need not be null terminated.