[PATCH v8 06/44] refs.c: add an err argument ro delete_loose_ref

[Ronnie Sahlberg <sahlberg@google.com>]

Add an err argument to delete_loose_ref so that we can pass a descriptive
error string back to the caller. Pass the err argument from transaction
commit to this function so that transaction users will have a nice error
string if the transaction failed due to delete_loose_ref failing.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
---
 refs.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/refs.c b/refs.c
index 072e3e9..a150520 100644
--- a/refs.c
+++ b/refs.c
@@ -2484,17 +2484,22 @@ static int repack_without_ref(const char *refname)
 	return repack_without_refs(&refname, 1, NULL);
 }
 
-static int delete_ref_loose(struct ref_lock *lock, int flag)
+static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)
 {
 	if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
 		/* loose */
-		int err, i = strlen(lock->lk->filename) - 5; /* .lock */
+		int res, i = strlen(lock->lk->filename) - 5; /* .lock */
 
 		lock->lk->filename[i] = 0;
-		err = unlink_or_warn(lock->lk->filename);
+		res = unlink_or_warn(lock->lk->filename);
 		lock->lk->filename[i] = '.';
-		if (err && errno != ENOENT)
+		if (res && errno != ENOENT) {
+			if (err)
+				strbuf_addf(err,
+					    "failed to delete loose ref '%s'",
+					    lock->lk->filename);
 			return 1;
+		}
 	}
 	return 0;
 }
@@ -2507,7 +2512,7 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
 	lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
 	if (!lock)
 		return 1;
-	ret |= delete_ref_loose(lock, flag);
+	ret |= delete_ref_loose(lock, flag, NULL);
 
 	/* removing the loose one could have resurrected an earlier
 	 * packed one.  Also, if it was not loose we need to repack
@@ -3492,7 +3497,8 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 
 		if (update->lock) {
 			delnames[delnum++] = update->lock->ref_name;
-			ret |= delete_ref_loose(update->lock, update->type);
+			ret |= delete_ref_loose(update->lock, update->type,
+						err);
 		}
 	}
 
-- 
2.0.0.rc3.477.g0f8edf7