[PATCH v2 7/8] object_as_type: set commit index

From: Jeff King <peff@peff.net>
Date: Jul 13, 2014, 06:42 UTC
Message-ID: <20140713064212.GG4852@sigill.intra.peff.net>
In-Reply-To: <20140713064116.GA4768@sigill.intra.peff.net>

The point of the "index" field of struct commit is that every allocated commit would have one. It is supposed to be an invariant that whenever object->type is set to OBJ_COMMIT, we have a unique index.

Commit 969eba6 (commit: push commit_index update into alloc_commit_node, 2014-06-10) covered this case for newly-allocated commits. However, we may also allocate an "unknown" object via lookup_unknown_object, and only later convert it to a commit. We must make sure that we set the commit index when we switch the type field.

Signed-off-by: Jeff King <peff@peff.net>
---
 object.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/object.c b/object.c
index b2319f6..69fbbbf 100644
--- a/object.c
+++ b/object.c
@@ -163,6 +163,8 @@ void *object_as_type(struct object *obj, enum object_type type, int quiet)
 	if (obj->type == type)
 		return obj;
 	else if (obj->type == OBJ_NONE) {
+		if (type == OBJ_COMMIT)
+			((struct commit *)obj)->index = alloc_commit_index();
 		obj->type = type;
 		return obj;
 	}

-- 
2.0.0.566.gfe3e6b2