ref_transaction_delete(): remove "have_old" parameter

Instead, verify the reference's old value if and only if old_sha1 is
non-NULL.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/receive-pack.c

@@ -953,8 +953,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 		if (ref_transaction_delete(transaction,
 					   namespaced_name,
 					   old_sha1,
-					   0, old_sha1 != NULL,
-					   "push", &err)) {
+					   0, "push", &err)) {
 			rp_error("%s", err.buf);
 			strbuf_release(&err);
 			return "failed to delete";

builtin/update-ref.c

@@ -265,8 +265,9 @@ static const char *parse_cmd_delete(struct ref_transaction *transaction,
 	if (*next != line_termination)
 		die("delete %s: extra input: %s", refname, next);
 
-	if (ref_transaction_delete(transaction, refname, old_sha1,
-				   update_flags, have_old, msg, &err))
+	if (ref_transaction_delete(transaction, refname,
+				   have_old ? old_sha1 : NULL,
+				   update_flags, msg, &err))
 		die("%s", err.buf);
 
 	update_flags = 0;

refs.c

@@ -2576,7 +2576,7 @@ static void prune_ref(struct ref_to_prune *r)
 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
 	    ref_transaction_delete(transaction, r->name, r->sha1,
-				   REF_ISPRUNING, 1, NULL, &err) ||
+				   REF_ISPRUNING, NULL, &err) ||
 	    ref_transaction_commit(transaction, &err)) {
 		ref_transaction_free(transaction);
 		error("%s", err.buf);
@@ -2753,8 +2753,9 @@ int delete_ref(const char *refname, const unsigned char *sha1, unsigned int flag
 
 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
-	    ref_transaction_delete(transaction, refname, sha1, flags,
-				   sha1 && !is_null_sha1(sha1), NULL, &err) ||
+	    ref_transaction_delete(transaction, refname,
+				   (sha1 && !is_null_sha1(sha1)) ? sha1 : NULL,
+				   flags, NULL, &err) ||
 	    ref_transaction_commit(transaction, &err)) {
 		error("%s", err.buf);
 		ref_transaction_free(transaction);
@@ -3696,11 +3697,11 @@ int ref_transaction_create(struct ref_transaction *transaction,
 int ref_transaction_delete(struct ref_transaction *transaction,
 			   const char *refname,
 			   const unsigned char *old_sha1,
-			   unsigned int flags, int have_old, const char *msg,
+			   unsigned int flags, const char *msg,
 			   struct strbuf *err)
 {
 	return ref_transaction_update(transaction, refname,
-				      null_sha1, have_old ? old_sha1 : NULL,
+				      null_sha1, old_sha1,
 				      flags, msg, err);
 }
 

refs.h

@@ -295,8 +295,8 @@ int ref_transaction_create(struct ref_transaction *transaction,
 			   struct strbuf *err);
 
 /*
- * Add a reference deletion to transaction.  If have_old is true, then
- * old_sha1 holds the value that the reference should have had before
+ * Add a reference deletion to transaction.  If old_sha1 is non-NULL, then
+ * it holds the value that the reference should have had before
  * the update (which must not be the null SHA-1).
  * Function returns 0 on success and non-zero on failure. A failure to delete
  * means that the transaction as a whole has failed and will need to be
@@ -305,7 +305,7 @@ int ref_transaction_create(struct ref_transaction *transaction,
 int ref_transaction_delete(struct ref_transaction *transaction,
 			   const char *refname,
 			   const unsigned char *old_sha1,
-			   unsigned int flags, int have_old, const char *msg,
+			   unsigned int flags, const char *msg,
 			   struct strbuf *err);
 
 /*