tree-diff: don't access hash of NULL object_id pointer

diff --git a/builtin/verify-commit.c b/builtin/verify-commit.c
index a5db1c427f55f8c636e7d1aadcf1499add04e81d..05b734e6d1bd469b63aa7b51921622a590730b6d 100644 (file)
--- a/builtin/verify-commit.c
+++ b/builtin/verify-commit.c
@@ -25,7 +25,7 @@ static int run_gpg_verify(const struct object_id *oid, const char *buf, unsigned
 
        memset(&signature_check, 0, sizeof(signature_check));
 
-       ret = check_commit_signature(lookup_commit(oid->hash), &signature_check);
+       ret = check_commit_signature(lookup_commit(oid), &signature_check);
        print_signature_buffer(&signature_check, flags);
 
        signature_check_clear(&signature_check);