[PATCH 3/5] register_ref_store(): new function

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

Move the responsibility for registering the ref_store for a submodule
from base_ref_store_init() to a new function, register_ref_store(). Call
the latter from ref_store_init().

This means that base_ref_store_init() can lose its submodule argument,
further weakening the 1:1 relationship between ref_stores and
submodules.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 refs.c               | 19 +++++++++++++------
 refs/files-backend.c |  2 +-
 refs/refs-internal.h | 15 ++++++++++-----
 3 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/refs.c b/refs.c
index 723b4be..6012f67 100644
--- a/refs.c
+++ b/refs.c
@@ -1395,11 +1395,8 @@ static struct ref_store *main_ref_store;
 /* A hashmap of ref_stores, stored by submodule name: */
 static struct hashmap submodule_ref_stores;
 
-void base_ref_store_init(struct ref_store *refs,
-			 const struct ref_storage_be *be,
-			 const char *submodule)
+void register_ref_store(struct ref_store *refs, const char *submodule)
 {
-	refs->be = be;
 	if (!submodule) {
 		if (main_ref_store)
 			die("BUG: main_ref_store initialized twice");
@@ -1416,18 +1413,28 @@ void base_ref_store_init(struct ref_store *refs,
 	}
 }
 
+void base_ref_store_init(struct ref_store *refs,
+			 const struct ref_storage_be *be)
+{
+	refs->be = be;
+}
+
 struct ref_store *ref_store_init(const char *submodule)
 {
 	const char *be_name = "files";
 	struct ref_storage_be *be = find_ref_storage_backend(be_name);
+	struct ref_store *refs;
 
 	if (!be)
 		die("BUG: reference backend %s is unknown", be_name);
 
 	if (!submodule || !*submodule)
-		return be->init(NULL);
+		refs = be->init(NULL);
 	else
-		return be->init(submodule);
+		refs = be->init(submodule);
+
+	register_ref_store(refs, submodule);
+	return refs;
 }
 
 struct ref_store *lookup_ref_store(const char *submodule)
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 6ed7e13..794b88c 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -980,7 +980,7 @@ static struct ref_store *files_ref_store_create(const char *submodule)
 	struct files_ref_store *refs = xcalloc(1, sizeof(*refs));
 	struct ref_store *ref_store = (struct ref_store *)refs;
 
-	base_ref_store_init(ref_store, &refs_be_files, submodule);
+	base_ref_store_init(ref_store, &refs_be_files);
 
 	refs->submodule = submodule ? xstrdup(submodule) : "";
 
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 97f275b..73281f5 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -481,7 +481,7 @@ struct ref_store;
  * Initialize the ref_store for the specified submodule, or for the
  * main repository if submodule == NULL. These functions should call
  * base_ref_store_init() to initialize the shared part of the
- * ref_store and to record the ref_store for later lookup.
+ * ref_store.
  */
 typedef struct ref_store *ref_store_init_fn(const char *submodule);
 
@@ -630,12 +630,17 @@ struct ref_store {
 };
 
 /*
- * Fill in the generic part of refs for the specified submodule and
- * add it to our collection of reference stores.
+ * Register the specified ref_store to be the one that should be used
+ * for submodule (or the main repository if submodule is NULL). It is
+ * a fatal error to call this function twice for the same submodule.
+ */
+void register_ref_store(struct ref_store *refs, const char *submodule);
+
+/*
+ * Fill in the generic part of refs.
  */
 void base_ref_store_init(struct ref_store *refs,
-			 const struct ref_storage_be *be,
-			 const char *submodule);
+			 const struct ref_storage_be *be);
 
 /*
  * Create, record, and return a ref_store instance for the specified
-- 
2.9.3