[PATCH v2 6/8] alloc: factor out commit index

[Jeff King <peff@peff.net>]

We keep a static counter to set the commit index on newly
allocated objects. However, since we also need to set the
index on any_objects which are converted to commits, let's
make the counter available as a public function.

While we're moving it, let's make sure the counter is
allocated as an unsigned integer to match the index field in
"struct commit".

Signed-off-by: Jeff King <peff@peff.net>
---
 alloc.c | 9 +++++++--
 cache.h | 1 +
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/alloc.c b/alloc.c
index fd2e32d..12afadf 100644
--- a/alloc.c
+++ b/alloc.c
@@ -82,12 +82,17 @@ void *alloc_object_node(void)
 
 static struct alloc_state commit_state;
 
+unsigned int alloc_commit_index(void)
+{
+	static unsigned int count;
+	return count++;
+}
+
 void *alloc_commit_node(void)
 {
-	static int commit_count;
 	struct commit *c = alloc_node(&commit_state, sizeof(struct commit));
 	c->object.type = OBJ_COMMIT;
-	c->index = commit_count++;
+	c->index = alloc_commit_index();
 	return c;
 }
 
diff --git a/cache.h b/cache.h
index 44aa439..ba68e11 100644
--- a/cache.h
+++ b/cache.h
@@ -1380,6 +1380,7 @@ extern void *alloc_commit_node(void);
 extern void *alloc_tag_node(void);
 extern void *alloc_object_node(void);
 extern void alloc_report(void);
+extern unsigned int alloc_commit_index(void);
 
 /* trace.c */
 __attribute__((format (printf, 1, 2)))
-- 
2.0.0.566.gfe3e6b2