extern char *sha1_pack_index_name(const unsigned char *sha1);
extern const char *find_unique_abbrev(const unsigned char *sha1, int);
extern const unsigned char null_sha1[20];
+static inline int is_null_sha1(const unsigned char *sha1)
+{
+ return !memcmp(sha1, null_sha1, 20);
+}
int git_mkstemp(char *path, size_t n, const char *template);