From 8e555dee560d77bcef5755841143d5c11928ab2a Mon Sep 17 00:00:00 2001
From: Tim Schaub <tim.schaub@gmail.com>
Date: Thu, 21 Feb 2013 12:12:12 -0700
Subject: [PATCH 1/3] Overriding createBackBuffer in UTFGrid layer

This layer doesn't need to create a backbuffer.
---
 lib/OpenLayers/Layer/UTFGrid.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/OpenLayers/Layer/UTFGrid.js b/lib/OpenLayers/Layer/UTFGrid.js
index 51db26402c..c6448816c4 100644
--- a/lib/OpenLayers/Layer/UTFGrid.js
+++ b/lib/OpenLayers/Layer/UTFGrid.js
@@ -109,6 +109,12 @@ OpenLayers.Layer.UTFGrid = OpenLayers.Class(OpenLayers.Layer.XYZ, {
             utfgridResolution: this.utfgridResolution
         }, this.tileOptions);
     },
+
+    /**
+     * Method: createBackBuffer
+     * The UTFGrid cannot create a back buffer, so this method is overriden.
+     */
+    createBackBuffer: function() {},
     
     /**
      * APIMethod: clone

From 461c5c43284f39726130fd8b6c16315f0e86aec3 Mon Sep 17 00:00:00 2001
From: Tim Schaub <tim.schaub@gmail.com>
Date: Thu, 21 Feb 2013 12:17:55 -0700
Subject: [PATCH 2/3] Test that createBackBuffer doesn't fail

---
 tests/Layer/UTFGrid.html | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tests/Layer/UTFGrid.html b/tests/Layer/UTFGrid.html
index 16cb852a02..08ff16d422 100644
--- a/tests/Layer/UTFGrid.html
+++ b/tests/Layer/UTFGrid.html
@@ -58,6 +58,19 @@
         layer.destroy();
 
     }
+
+    function test_createBackBuffer(t) {
+      t.plan(1);
+      setUp();
+
+      var got;
+      try {
+        got = layer.createBackBuffer();
+      } catch (e) {
+        got = e;
+      }
+      t.eq(got, undefined, "createBackBuffer returns undefined");
+    }
     
     function test_clone(t) {
         t.plan(3);

From 7c4df5186f81eebf3d11ebb1c1a6a4eb79f5340b Mon Sep 17 00:00:00 2001
From: Tim Schaub <tim.schaub@gmail.com>
Date: Thu, 21 Feb 2013 12:19:34 -0700
Subject: [PATCH 3/3] Test clean up

---
 tests/Layer/UTFGrid.html | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tests/Layer/UTFGrid.html b/tests/Layer/UTFGrid.html
index 08ff16d422..f90403e6f0 100644
--- a/tests/Layer/UTFGrid.html
+++ b/tests/Layer/UTFGrid.html
@@ -68,6 +68,8 @@
         got = layer.createBackBuffer();
       } catch (e) {
         got = e;
+      } finally {
+        tearDown();
       }
       t.eq(got, undefined, "createBackBuffer returns undefined");
     }