From 60e7698f1aaa14e12951e2c814a82104f5b378d0 Mon Sep 17 00:00:00 2001
From: John Firebaugh <john.firebaugh@gmail.com>
Date: Tue, 4 Dec 2012 13:30:29 -0500
Subject: [PATCH] Don't mutate entity in place

---
 js/id/graph/graph.js     | 5 ++---
 test/spec/graph/graph.js | 9 +++++++++
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/js/id/graph/graph.js b/js/id/graph/graph.js
index 41000fd11..1410dea41 100644
--- a/js/id/graph/graph.js
+++ b/js/id/graph/graph.js
@@ -88,13 +88,12 @@ iD.Graph.prototype = {
 
     // Resolve the id references in a way, replacing them with actual objects.
     fetch: function(id) {
-        var entity = iD.Entity(this.entities[id]), nodes = [];
+        var entity = this.entities[id], nodes = [];
         if (!entity.nodes || !entity.nodes.length) return entity;
         for (var i = 0, l = entity.nodes.length; i < l; i++) {
             nodes[i] = this.fetch(entity.nodes[i]);
         }
-        entity.nodes = nodes;
-        return entity;
+        return iD.Entity(entity, {nodes: nodes});
     },
 
     modifications: function() {
diff --git a/test/spec/graph/graph.js b/test/spec/graph/graph.js
index b90cde1f1..b026a8be3 100644
--- a/test/spec/graph/graph.js
+++ b/test/spec/graph/graph.js
@@ -54,6 +54,15 @@ describe('Graph', function() {
         });
     });
 
+    describe("#fetch", function () {
+        it("replaces node ids with references", function () {
+            var node  = iD.Node({id: "n1"}),
+                way   = iD.Way({id: "w1", nodes: ["n1"]}),
+                graph = iD.Graph({n1: node, w1: way});
+            expect(graph.fetch("w1").nodes).to.eql([node]);
+        });
+    });
+
     describe("#modifications", function () {
         it("filters entities by modified", function () {
             var a = {id: 'a', modified: function () { return true; }},