[PATCH v2 3/7] invalidate_ref_cache(): expose this function in refs API

[Michael Haggerty <mhagger@alum.mit.edu>]

Make invalidate_ref_cache() an official part of the refs API.  It is
currently a fact of life that code outside of refs.c mucks about with
references.  This change gives such code a way of informing the refs
module that it should no longer trust its cache.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 refs.c |    2 +-
 refs.h |    8 ++++++++
 2 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/refs.c b/refs.c
index 89b2a0e..fb46cf5 100644
--- a/refs.c
+++ b/refs.c
@@ -223,7 +223,7 @@ static struct cached_refs *get_cached_refs(const char *submodule)
 	return refs;
 }
 
-static void invalidate_ref_cache(const char *submodule)
+void invalidate_ref_cache(const char *submodule)
 {
 	clear_cached_refs(get_cached_refs(submodule));
 }
diff --git a/refs.h b/refs.h
index 5de06e5..3ddc4e4 100644
--- a/refs.h
+++ b/refs.h
@@ -77,6 +77,14 @@ extern void unlock_ref(struct ref_lock *lock);
 /** Writes sha1 into the ref specified by the lock. **/
 extern int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, const char *msg);
 
+/*
+ * Invalidate the reference cache for the specified submodule.  Use
+ * submodule=NULL to invalidate the cache for the main module.  This
+ * function must be called if references are changed via a mechanism
+ * other than the refs API.
+ */
+extern void invalidate_ref_cache(const char *submodule);
+
 /** Setup reflog before using. **/
 int log_ref_setup(const char *ref_name, char *logfile, int bufsize);
 
-- 
1.7.7.rc2