sha1-name.c: add repo_for_each_abbrev()

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/cache.h b/cache.h
index 4f8ebb0..0cb95c0 100644
--- a/cache.h
+++ b/cache.h
@@ -1392,7 +1392,8 @@ extern enum get_oid_result get_oid_with_context(struct repository *repo, const c
 				struct object_context *oc);
 
 typedef int each_abbrev_fn(const struct object_id *oid, void *);
-extern int for_each_abbrev(const char *prefix, each_abbrev_fn, void *);
+int repo_for_each_abbrev(struct repository *r, const char *prefix, each_abbrev_fn, void *);
+#define for_each_abbrev(prefix, fn, data) repo_for_each_abbrev(the_repository, prefix, fn, data)
 
 extern int set_disambiguate_hint_config(const char *var, const char *value);