[gitg] Use weak ref to commit in lane list

[Jesse van den Kieboom <jessevdk src gnome org>]

commit 3579a9db2244daaf74f8c3d58963dae4ecd0be80
Author: Jesse van den Kieboom <jessevdk gnome org>
Date:   Wed Jun 11 14:58:31 2014 +0200

    Use weak ref to commit in lane list

 libgitg/gitg-lanes.vala |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/libgitg/gitg-lanes.vala b/libgitg/gitg-lanes.vala
index 36007a2..88fa500 100644
--- a/libgitg/gitg-lanes.vala
+++ b/libgitg/gitg-lanes.vala
@@ -27,8 +27,8 @@ public class Lanes : Object
        public int inactive_gap { get; set; }
        public bool inactive_enabled { get; set; }
 
-       private SList<Commit> d_previous;
        private SList<LaneContainer> d_lanes;
+       private SList<weak Commit> d_previous;
        private HashTable<Ggit.OId, CollapsedLane> d_collapsed;
 
        [Compact]
@@ -96,8 +96,8 @@ public class Lanes : Object
 
        public void reset()
        {
-               d_previous = new SList<Commit>();
                d_lanes = new SList<LaneContainer>();
+               d_previous = new SList<weak Commit>();
 
                Color.reset();
 
@@ -228,7 +228,7 @@ public class Lanes : Object
        {
                add_collapsed(container, index);
 
-               unowned SList<Commit> item = d_previous;
+               unowned SList<weak Commit> item = d_previous;
 
                while (item != null)
                {