[PATCH v11 31/41] refs.c: make prune_ref use a transaction to delete the ref

[Ronnie Sahlberg <sahlberg@google.com>]

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>
---
 refs.c | 28 +++++++++++++++++++++-------
 refs.h |  5 +++++
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/refs.c b/refs.c
index 4ca84f7..1819434 100644
--- a/refs.c
+++ b/refs.c
@@ -30,6 +30,12 @@ static inline int bad_ref_char(int ch)
 }
 
 /*
+ * Used as a flag to ref_transaction_delete when a loose ref is being
+ * 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
  * legal.
@@ -2328,17 +2334,24 @@ 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(&err);
+	if (!transaction ||
+	    ref_transaction_delete(transaction, r->name, r->sha1,
+				   REF_ISPRUNING, 1, &err) ||
+	    ref_transaction_commit(transaction, NULL, &err)) {
+		ref_transaction_free(transaction);
+		error("%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)
@@ -3546,9 +3559,10 @@ 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;
 		}
 	}
 
diff --git a/refs.h b/refs.h
index 1e25e1c..39c97f8 100644
--- a/refs.h
+++ b/refs.h
@@ -235,6 +235,11 @@ struct ref_transaction *ref_transaction_begin(struct strbuf *err);
  */
 
 /*
+ * ref_transaction_update ref_transaction_create and ref_transaction_delete
+ * all take a flag argument. Currently the only public flag is REF_NODEREF.
+ * Flag values >= 0x100 are reserved for internal use.
+ */
+/*
  * Add a reference update to transaction.  new_sha1 is the value that
  * the reference should have after the update, or zeros if it should
  * be deleted.  If have_old is true, then old_sha1 holds the value
-- 
2.0.0.rc3.474.g0203784