push: keep track of "update" state separately

If the reference exists on the remote and it is not being removed, then
mark as an update.  This is in preparation for handling tags (lightweight
and annotated) exceptionally.

Signed-off-by: Chris Rorvick <chris@rorvick.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -1003,6 +1003,7 @@ struct ref {
 		merge:1,
 		nonfastforward:1,
 		not_forwardable:1,
+		update:1,
 		deletion:1;
 	enum {
 		REF_STATUS_NONE = 0,

remote.c

@@ -1326,15 +1326,19 @@ void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
 
 		ref->not_forwardable = !is_forwardable(ref);
 
-		ref->nonfastforward =
+		ref->update =
 			!ref->deletion &&
-			!is_null_sha1(ref->old_sha1) &&
-			(!has_sha1_file(ref->old_sha1)
-			  || !ref_newer(ref->new_sha1, ref->old_sha1));
+			!is_null_sha1(ref->old_sha1);
 
-		if (ref->nonfastforward && !ref->force && !force_update) {
-			ref->status = REF_STATUS_REJECT_NONFASTFORWARD;
-			continue;
+		if (ref->update) {
+			ref->nonfastforward =
+				!has_sha1_file(ref->old_sha1)
+				  || !ref_newer(ref->new_sha1, ref->old_sha1);
+
+			if (ref->nonfastforward && !ref->force && !force_update) {
+				ref->status = REF_STATUS_REJECT_NONFASTFORWARD;
+				continue;
+			}
 		}
 	}
 }