[ostree] traverse: Require variant when traversing dirtree

[Colin Walters <walters src gnome org>]

commit 7524e904b90d24929dd8b9ac975aed2b46550edf
Author: Dan Nicholson <nicholson endlessm com>
Date:   Wed Mar 23 09:32:29 2016 -0700

    traverse: Require variant when traversing dirtree
    
    The dirtree object is required for traversing, so don't use the
    load_variant_if_exists() function. This will return a
    G_IO_ERROR_NOT_FOUND to the caller rather than trying to ref a NULL
    variant in ostree_repo_commit_traverse_iter_init_dirtree() if the object
    is missing.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=764091

 src/libostree/ostree-repo-traverse.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/src/libostree/ostree-repo-traverse.c b/src/libostree/ostree-repo-traverse.c
index 85ce317..97bd102 100644
--- a/src/libostree/ostree-repo-traverse.c
+++ b/src/libostree/ostree-repo-traverse.c
@@ -377,9 +377,8 @@ traverse_dirtree (OstreeRepo           *repo,
   ostree_cleanup_repo_commit_traverse_iter
     OstreeRepoCommitTraverseIter iter = { 0, };
 
-  if (!ostree_repo_load_variant_if_exists (repo, OSTREE_OBJECT_TYPE_DIR_TREE,
-                                           checksum, &dirtree,
-                                           error))
+  if (!ostree_repo_load_variant (repo, OSTREE_OBJECT_TYPE_DIR_TREE, checksum,
+                                 &dirtree, error))
     goto out;
 
   if (!ostree_repo_commit_traverse_iter_init_dirtree (&iter, repo, dirtree,