commit: add repository argument to get_cached_commit_buffer

Add a repository argument to allow callers of get_cached_commit_buffer to
be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/commit.c b/commit.c
index cdfb1a0..9e2899b 100644
--- a/commit.c
+++ b/commit.c
@@ -269,7 +269,7 @@ void set_commit_buffer_the_repository(struct commit *commit, void *buffer, unsig
 	v->size = size;
 }
 
-const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
+const void *get_cached_commit_buffer_the_repository(const struct commit *commit, unsigned long *sizep)
 {
 	struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
 	if (!v) {
@@ -284,7 +284,7 @@ const void *get_cached_commit_buffer(const struct commit *commit, unsigned long
 
 const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
 {
-	const void *ret = get_cached_commit_buffer(commit, sizep);
+	const void *ret = get_cached_commit_buffer(the_repository, commit, sizep);
 	if (!ret) {
 		enum object_type type;
 		unsigned long size;