lock_ref_sha1_basic(): do not set force_write for missing references

If a reference is missing, its SHA-1 will be null_sha1, which can't
possibly match a new value that ref_transaction_commit() is trying to
update it to. So there is no need to set force_write in this scenario.

Signed-off-by: Michael Haggerty <[email protected]>
Reviewed-by: Stefan Beller <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: mhagger

refs.c

@@ -2259,7 +2259,6 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 	int type, lflags;
 	int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
 	int resolve_flags = 0;
-	int missing = 0;
 	int attempts_remaining = 3;
 
 	lock = xcalloc(1, sizeof(struct ref_lock));
@@ -2298,13 +2297,13 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 			orig_refname, strerror(errno));
 		goto error_return;
 	}
-	missing = is_null_sha1(lock->old_sha1);
-	/* When the ref did not exist and we are creating it,
-	 * make sure there is no existing ref that is packed
-	 * whose name begins with our refname, nor a ref whose
-	 * name is a proper prefix of our refname.
+	/*
+	 * If the ref did not exist and we are creating it, make sure
+	 * there is no existing packed ref whose name begins with our
+	 * refname, nor a packed ref whose name is a proper prefix of
+	 * our refname.
 	 */
-	if (missing &&
+	if (is_null_sha1(lock->old_sha1) &&
 	     !is_refname_available(refname, skip, get_packed_refs(&ref_cache))) {
 		last_errno = ENOTDIR;
 		goto error_return;
@@ -2320,8 +2319,6 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 	lock->ref_name = xstrdup(refname);
 	lock->orig_ref_name = xstrdup(orig_refname);
 	ref_file = git_path("%s", refname);
-	if (missing)
-		lock->force_write = 1;
 	if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
 		lock->force_write = 1;