refs: move `original_update_refname` to 'refs.c'

The files backend and the reftable backend implement
`original_update_refname` to obtain the original refname of the update.
Move it out to 'refs.c' and only expose it internally to the refs
library. This will be used in an upcoming commit to also introduce
another common functionality for the two backends.

We also rename the function to `ref_update_original_update_refname` to
keep it consistent with the upcoming other 'ref_update_*' functions
that'll be introduced.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

4 files changed, 25 insertions, 33 deletions

diff --git a/refs.c b/refs.c
index 9d722d798a5..990703ed168 100644
--- a/refs.c
+++ b/refs.c
@@ -2814,3 +2814,11 @@ int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg
 {
 	return refs_copy_existing_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
 }
+
+const char *ref_update_original_update_refname(struct ref_update *update)
+{
+	while (update->parent_update)
+		update = update->parent_update;
+
+	return update->refname;
+}
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 74a713090ca..25e5d03496e 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2424,17 +2424,6 @@ static int split_symref_update(struct ref_update *update,
 }
 
 /*
- * Return the refname under which update was originally requested.
- */
-static const char *original_update_refname(struct ref_update *update)
-{
-	while (update->parent_update)
-		update = update->parent_update;
-
-	return update->refname;
-}
-
-/*
  * Check whether the REF_HAVE_OLD and old_oid values stored in update
  * are consistent with oid, which is the reference's current value. If
  * everything is OK, return 0; otherwise, write an error message to
@@ -2450,16 +2439,16 @@ static int check_old_oid(struct ref_update *update, struct object_id *oid,
 	if (is_null_oid(&update->old_oid))
 		strbuf_addf(err, "cannot lock ref '%s': "
 			    "reference already exists",
-			    original_update_refname(update));
+			    ref_update_original_update_refname(update));
 	else if (is_null_oid(oid))
 		strbuf_addf(err, "cannot lock ref '%s': "
 			    "reference is missing but expected %s",
-			    original_update_refname(update),
+			    ref_update_original_update_refname(update),
 			    oid_to_hex(&update->old_oid));
 	else
 		strbuf_addf(err, "cannot lock ref '%s': "
 			    "is at %s but expected %s",
-			    original_update_refname(update),
+			    ref_update_original_update_refname(update),
 			    oid_to_hex(oid),
 			    oid_to_hex(&update->old_oid));
 
@@ -2513,7 +2502,7 @@ static int lock_ref_for_update(struct files_ref_store *refs,
 
 		reason = strbuf_detach(err, NULL);
 		strbuf_addf(err, "cannot lock ref '%s': %s",
-			    original_update_refname(update), reason);
+			    ref_update_original_update_refname(update), reason);
 		free(reason);
 		goto out;
 	}
@@ -2533,7 +2522,7 @@ static int lock_ref_for_update(struct files_ref_store *refs,
 				if (update->flags & REF_HAVE_OLD) {
 					strbuf_addf(err, "cannot lock ref '%s': "
 						    "error reading reference",
-						    original_update_refname(update));
+						    ref_update_original_update_refname(update));
 					ret = TRANSACTION_GENERIC_ERROR;
 					goto out;
 				}
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 108f4ec4199..617b93a6c85 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -749,4 +749,9 @@ void base_ref_store_init(struct ref_store *refs, struct repository *repo,
  */
 struct ref_store *maybe_debug_wrap_ref_store(const char *gitdir, struct ref_store *store);
 
+/*
+ * Return the refname under which update was originally requested.
+ */
+const char *ref_update_original_update_refname(struct ref_update *update);
+
 #endif /* REFS_REFS_INTERNAL_H */
diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c
index e6122837c0a..fe4a7681a09 100644
--- a/refs/reftable-backend.c
+++ b/refs/reftable-backend.c
@@ -578,16 +578,6 @@ static int reftable_be_read_symbolic_ref(struct ref_store *ref_store,
 	return ret;
 }
 
-/*
- * Return the refname under which update was originally requested.
- */
-static const char *original_update_refname(struct ref_update *update)
-{
-	while (update->parent_update)
-		update = update->parent_update;
-	return update->refname;
-}
-
 struct reftable_transaction_update {
 	struct ref_update *update;
 	struct object_id current_oid;
@@ -866,7 +856,7 @@ static int reftable_be_transaction_prepare(struct ref_store *ref_store,
 			/* The reference does not exist, but we expected it to. */
 			strbuf_addf(err, _("cannot lock ref '%s': "
 				    "unable to resolve reference '%s'"),
-				    original_update_refname(u), u->refname);
+				    ref_update_original_update_refname(u), u->refname);
 			ret = -1;
 			goto done;
 		}
@@ -938,17 +928,17 @@ static int reftable_be_transaction_prepare(struct ref_store *ref_store,
 		if (u->flags & REF_HAVE_OLD && !oideq(&current_oid, &u->old_oid)) {
 			if (is_null_oid(&u->old_oid))
 				strbuf_addf(err, _("cannot lock ref '%s': "
-					    "reference already exists"),
-					    original_update_refname(u));
+						   "reference already exists"),
+					    ref_update_original_update_refname(u));
 			else if (is_null_oid(&current_oid))
 				strbuf_addf(err, _("cannot lock ref '%s': "
-					    "reference is missing but expected %s"),
-					    original_update_refname(u),
+						   "reference is missing but expected %s"),
+					    ref_update_original_update_refname(u),
 					    oid_to_hex(&u->old_oid));
 			else
 				strbuf_addf(err, _("cannot lock ref '%s': "
-					    "is at %s but expected %s"),
-					    original_update_refname(u),
+						   "is at %s but expected %s"),
+					    ref_update_original_update_refname(u),
 					    oid_to_hex(&current_oid),
 					    oid_to_hex(&u->old_oid));
 			ret = -1;