From 28cbef5bb67701cefd8d2a3fc9a0dc6fc5e23058 Mon Sep 17 00:00:00 2001
From: Nils Schneider <nils@nilsschneider.net>
Date: Sun, 22 Mar 2015 14:21:11 +0100
Subject: [PATCH] make linkId unique

---
 history.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/history.js b/history.js
index bbc066e..e91c7cf 100644
--- a/history.js
+++ b/history.js
@@ -195,7 +195,9 @@ function showTq(d) {
 }
 
 function linkId(d) {
-  return d.source.node.nodeinfo.node_id + "-" + d.target.node.nodeinfo.node_id
+  var ids = [d.source.node.nodeinfo.node_id, d.target.node.nodeinfo.node_id]
+
+  return ids.sort().join("-")
 }
 
 function mkmap(map, newnodes, lostnodes, onlinenodes, graph, gotoAnything) {