[PATCH v3 4/9] refs: return `ref_transaction_error` from `ref_transaction_update()`

[Karthik Nayak <karthik.188@gmail.com>]

The `ref_transaction_update()` function is used to add updates to a
given reference transactions. In the following commit, we'll add more
validation to this function. As such, it would be beneficial if the
function returns specific error types, so callers can differentiate
between different errors.

To facilitate this, return `enum ref_transaction_error` from the
function and covert the existing '-1' returns to
'REF_TRANSACTION_ERROR_GENERIC'. Since this retains the existing
behavior, no changes are made to any of the callers but this sets the
necessary infrastructure for introduction of other errors.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
---
 refs.c | 20 ++++++++++----------
 refs.h | 16 ++++++++--------
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/refs.c b/refs.c
index 6b506aeea3..efa16b739d 100644
--- a/refs.c
+++ b/refs.c
@@ -1383,25 +1383,25 @@ static int transaction_refname_valid(const char *refname,
 	return 1;
 }
 
-int ref_transaction_update(struct ref_transaction *transaction,
-			   const char *refname,
-			   const struct object_id *new_oid,
-			   const struct object_id *old_oid,
-			   const char *new_target,
-			   const char *old_target,
-			   unsigned int flags, const char *msg,
-			   struct strbuf *err)
+enum ref_transaction_error ref_transaction_update(struct ref_transaction *transaction,
+						  const char *refname,
+						  const struct object_id *new_oid,
+						  const struct object_id *old_oid,
+						  const char *new_target,
+						  const char *old_target,
+						  unsigned int flags, const char *msg,
+						  struct strbuf *err)
 {
 	assert(err);
 
 	if ((flags & REF_FORCE_CREATE_REFLOG) &&
 	    (flags & REF_SKIP_CREATE_REFLOG)) {
 		strbuf_addstr(err, _("refusing to force and skip creation of reflog"));
-		return -1;
+		return REF_TRANSACTION_ERROR_GENERIC;
 	}
 
 	if (!transaction_refname_valid(refname, new_oid, flags, err))
-		return -1;
+		return REF_TRANSACTION_ERROR_GENERIC;
 
 	if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
 		BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
diff --git a/refs.h b/refs.h
index d65de6ab5f..71d5c186d0 100644
--- a/refs.h
+++ b/refs.h
@@ -905,14 +905,14 @@ struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
  * See the above comment "Reference transaction updates" for more
  * information.
  */
-int ref_transaction_update(struct ref_transaction *transaction,
-			   const char *refname,
-			   const struct object_id *new_oid,
-			   const struct object_id *old_oid,
-			   const char *new_target,
-			   const char *old_target,
-			   unsigned int flags, const char *msg,
-			   struct strbuf *err);
+enum ref_transaction_error ref_transaction_update(struct ref_transaction *transaction,
+						  const char *refname,
+						  const struct object_id *new_oid,
+						  const struct object_id *old_oid,
+						  const char *new_target,
+						  const char *old_target,
+						  unsigned int flags, const char *msg,
+						  struct strbuf *err);
 
 /*
  * Similar to `ref_transaction_update`, but this function is only for adding

-- 
2.53.GIT