From 6407fa464c60f04927745e8968866867c081bf3b Mon Sep 17 00:00:00 2001
From: Tom MacWright <tom@macwright.org>
Date: Wed, 16 Jan 2013 14:06:11 -0500
Subject: [PATCH] Run intersection on difference changes, do not use compact.
 Fixes #334

---
 js/id/graph/way.js    |  3 ++-
 js/id/renderer/map.js | 19 +++++++++++--------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/js/id/graph/way.js b/js/id/graph/way.js
index 77858d29a..5c3e1210b 100644
--- a/js/id/graph/way.js
+++ b/js/id/graph/way.js
@@ -6,7 +6,8 @@ iD.Way = iD.Entity.extend({
         return resolver.transient(this, 'extent', function() {
             var extent = [[-Infinity, Infinity], [Infinity, -Infinity]];
             for (var i = 0, l = this.nodes.length; i < l; i++) {
-                var node = resolver.entity(this.nodes[i]);
+                var node = this.nodes[i];
+                if (node.loc === undefined) node = resolver.entity(node);
                 if (node.loc[0] > extent[0][0]) extent[0][0] = node.loc[0];
                 if (node.loc[0] < extent[1][0]) extent[1][0] = node.loc[0];
                 if (node.loc[1] < extent[0][1]) extent[0][1] = node.loc[1];
diff --git a/js/id/renderer/map.js b/js/id/renderer/map.js
index 764fa83ae..9d80676f4 100644
--- a/js/id/renderer/map.js
+++ b/js/id/renderer/map.js
@@ -65,18 +65,21 @@ iD.Map = function() {
             var only = {};
             for (var j = 0; j < difference.length; j++) {
                 var id = difference[j];
-                only[id] = graph.fetch(id);
-                if (only[id] && only[id].type === 'node') {
-                    var parents = graph.parentWays(only[id]);
-                    for (var k = 0; k < parents.length; k++) {
-                        // Don't re-fetch parents
-                        if (only[parents[k].id] === undefined) {
-                            only[parents[k].id] = graph.fetch(parents[k].id);
+                var entity = graph.fetch(id);
+                if (entity && entity.intersects(extent, graph)) {
+                    only[id] = entity;
+                    if (only[id].type === 'node') {
+                        var parents = graph.parentWays(only[id]);
+                        for (var k = 0; k < parents.length; k++) {
+                            // Don't re-fetch parents
+                            if (only[parents[k].id] === undefined) {
+                                only[parents[k].id] = graph.fetch(parents[k].id);
+                            }
                         }
                     }
                 }
             }
-            all = _.compact(_.values(only));
+            all = _.values(only);
             filter = function(d) { return d.midpoint ? d.way in only : d.id in only; };
         }