refs: pass NULL to resolve_ref_unsafe() if hash is not needed

This allows us to get rid of some write-only variables, among them seven
SHA1 buffers.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/branch.c b/branch.c
index 703ded6..4377ce2 100644
--- a/branch.c
+++ b/branch.c
@@ -191,9 +191,8 @@ int validate_new_branchname(const char *name, struct strbuf *ref,
 
 	if (!attr_only) {
 		const char *head;
-		struct object_id oid;
 
-		head = resolve_ref_unsafe("HEAD", 0, oid.hash, NULL);
+		head = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
 		if (!is_bare_repository() && head && !strcmp(head, ref->buf))
 			die(_("Cannot force update the current branch."));
 	}