[PATCH v2 15/25] ref_update_reject_duplicates(): expose function to whole refs module

[Michael Haggerty <mhagger@xxxxxxxxxxxx>]

It will soon have some other users.

Signed-off-by: Michael Haggerty <mhagger@xxxxxxxxxxxx>
---
 refs.c               | 17 +++++++++++++++++
 refs/files-backend.c | 17 -----------------
 refs/refs-internal.h |  8 ++++++++
 3 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/refs.c b/refs.c
index b3860a9e33..beb49fb297 100644
--- a/refs.c
+++ b/refs.c
@@ -1702,6 +1702,23 @@ int create_symref(const char *ref_target, const char *refs_heads_master,
 				  refs_heads_master, logmsg);
 }
 
+int ref_update_reject_duplicates(struct string_list *refnames,
+				 struct strbuf *err)
+{
+	int i, n = refnames->nr;
+
+	assert(err);
+
+	for (i = 1; i < n; i++)
+		if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {
+			strbuf_addf(err,
+				    "multiple updates for ref '%s' not allowed.",
+				    refnames->items[i].string);
+			return 1;
+		}
+	return 0;
+}
+
 int ref_transaction_prepare(struct ref_transaction *transaction,
 			    struct strbuf *err)
 {
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 19842d2e56..8d0ce739a6 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2512,23 +2512,6 @@ static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_st
 	return ref_iterator;
 }
 
-static int ref_update_reject_duplicates(struct string_list *refnames,
-					struct strbuf *err)
-{
-	int i, n = refnames->nr;
-
-	assert(err);
-
-	for (i = 1; i < n; i++)
-		if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) {
-			strbuf_addf(err,
-				    "multiple updates for ref '%s' not allowed.",
-				    refnames->items[i].string);
-			return 1;
-		}
-	return 0;
-}
-
 /*
  * If update is a direct update of head_ref (the reference pointed to
  * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 4d3dd17f9f..192f9f85c9 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -169,6 +169,14 @@ int refs_read_raw_ref(struct ref_store *ref_store,
 		      const char *refname, unsigned char *sha1,
 		      struct strbuf *referent, unsigned int *type);
 
+/*
+ * Write an error to `err` and return a nonzero value iff the same
+ * refname appears multiple times in `refnames`. `refnames` must be
+ * sorted on entry to this function.
+ */
+int ref_update_reject_duplicates(struct string_list *refnames,
+				 struct strbuf *err);
+
 /*
  * Add a ref_update with the specified properties to transaction, and
  * return a pointer to the new object. This function does not verify
-- 
2.11.0