refs.c: make prune_ref use a transaction to delete the ref

Change prune_ref to delete the ref using a ref transaction. To do this we also
need to add a new flag REF_ISPRUNING that will tell the transaction that we
do not want to delete this ref from the packed refs. This flag is private to
refs.c and not exposed to external callers.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 20 insertions, 7 deletions

diff --git a/refs.c b/refs.c
index f1ef940d49..88ab01209b 100644
--- a/refs.c
+++ b/refs.c
@@ -29,6 +29,11 @@ static inline int bad_ref_char(int ch)
 	return 0;
 }
 
+/** Used as a flag to ref_transaction_delete when a loose ref is beeing
+ *  pruned.
+ */
+#define REF_ISPRUNING	0x0100
+
 /*
  * Try to read one refname component from the front of refname.  Return
  * the length of the component found, or -1 if the component is not
@@ -2326,17 +2331,24 @@ static void try_remove_empty_parents(char *name)
 /* make sure nobody touched the ref, and unlink */
 static void prune_ref(struct ref_to_prune *r)
 {
-	struct ref_lock *lock;
+	struct ref_transaction *transaction;
+	struct strbuf err = STRBUF_INIT;
 
 	if (check_refname_format(r->name + 5, 0))
 		return;
 
-	lock = lock_ref_sha1_basic(r->name, r->sha1, 0, NULL);
-	if (lock) {
-		unlink_or_warn(git_path("%s", r->name));
-		unlock_ref(lock);
-		try_remove_empty_parents(r->name);
+	transaction = ref_transaction_begin();
+	if (!transaction ||
+	    ref_transaction_delete(transaction, r->name, r->sha1,
+				   REF_ISPRUNING, 1) ||
+	    ref_transaction_commit(transaction, NULL, &err)) {
+		ref_transaction_rollback(transaction);
+		warning("prune_ref: %s", err.buf);
+		strbuf_release(&err);
+		return;
 	}
+	ref_transaction_free(transaction);
+	try_remove_empty_parents(r->name);
 }
 
 static void prune_refs(struct ref_to_prune *r)
@@ -3512,9 +3524,10 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 		struct ref_update *update = updates[i];
 
 		if (update->lock) {
-			delnames[delnum++] = update->lock->ref_name;
 			ret |= delete_ref_loose(update->lock, update->type,
 						err);
+			if (!(update->flags & REF_ISPRUNING))
+				delnames[delnum++] = update->lock->ref_name;
 		}
 	}