alloc: add repository argument to alloc_commit_index

This is a small mechanical change; it doesn't change the
implementation to handle repositories other than the_repository yet.
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>

alloc.c

@@ -82,7 +82,7 @@ void *alloc_object_node_the_repository(void)
 
 static struct alloc_state commit_state;
 
-unsigned int alloc_commit_index(void)
+unsigned int alloc_commit_index_the_repository(void)
 {
 	static unsigned int count;
 	return count++;
@@ -92,7 +92,7 @@ void *alloc_commit_node_the_repository(void)
 {
 	struct commit *c = alloc_node(&commit_state, sizeof(struct commit));
 	c->object.type = OBJ_COMMIT;
-	c->index = alloc_commit_index();
+	c->index = alloc_commit_index(the_repository);
 	return c;
 }
 

cache.h

@@ -1776,7 +1776,8 @@ extern void *alloc_tag_node_the_repository(void);
 extern void *alloc_object_node_the_repository(void);
 #define alloc_report(r) alloc_report_##r()
 extern void alloc_report_the_repository(void);
-extern unsigned int alloc_commit_index(void);
+#define alloc_commit_index(r) alloc_commit_index_##r()
+extern unsigned int alloc_commit_index_the_repository(void);
 
 /* pkt-line.c */
 void packet_trace_identity(const char *prog);

object.c

@@ -162,7 +162,7 @@ void *object_as_type(struct object *obj, enum object_type type, int quiet)
 		return obj;
 	else if (obj->type == OBJ_NONE) {
 		if (type == OBJ_COMMIT)
-			((struct commit *)obj)->index = alloc_commit_index();
+			((struct commit *)obj)->index = alloc_commit_index(the_repository);
 		obj->type = type;
 		return obj;
 	}