diff --git a/fast-import.c b/fast-import.c
index 655913ddb27f758ce494fc18551e852c9a6aa9f1..73e5439d97481a0e4dcaa17d025b27ec3fdcf41b 100644 (file)
--- a/fast-import.c
+++ b/fast-import.c
struct ref_lock *lock;
unsigned char old_sha1[20];
+ if (is_null_sha1(b->sha1))
+ return 0;
if (read_ref(b->name, old_sha1))
hashclr(old_sha1);
lock = lock_any_ref_for_update(b->name, old_sha1, 0);