commit: add repository argument to lookup_commit_reference

Add a repository argument to allow callers of lookup_commit_reference
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/notes-merge.c b/notes-merge.c
index 9cc2ee1..76ab19e 100644
--- a/notes-merge.c
+++ b/notes-merge.c
@@ -2,6 +2,7 @@
 #include "commit.h"
 #include "refs.h"
 #include "object-store.h"
+#include "repository.h"
 #include "diff.h"
 #include "diffcore.h"
 #include "xdiff-interface.h"
@@ -553,7 +554,7 @@ int notes_merge(struct notes_merge_options *o,
 	else if (!check_refname_format(o->local_ref, 0) &&
 		is_null_oid(&local_oid))
 		local = NULL; /* local_oid == null_oid indicates unborn ref */
-	else if (!(local = lookup_commit_reference(&local_oid)))
+	else if (!(local = lookup_commit_reference(the_repository, &local_oid)))
 		die("Could not parse local commit %s (%s)",
 		    oid_to_hex(&local_oid), o->local_ref);
 	trace_printf("\tlocal commit: %.7s\n", oid_to_hex(&local_oid));
@@ -571,7 +572,7 @@ int notes_merge(struct notes_merge_options *o,
 			die("Failed to resolve remote notes ref '%s'",
 			    o->remote_ref);
 		}
-	} else if (!(remote = lookup_commit_reference(&remote_oid))) {
+	} else if (!(remote = lookup_commit_reference(the_repository, &remote_oid))) {
 		die("Could not parse remote commit %s (%s)",
 		    oid_to_hex(&remote_oid), o->remote_ref);
 	}