From dbccb8b23170ca19c415a1e1058c722afb94322f Mon Sep 17 00:00:00 2001
From: Tim Schaub <tim.schaub@gmail.com>
Date: Tue, 3 Sep 2013 17:38:10 -0600
Subject: [PATCH] Function for cloning extents

---
 src/ol/extent.js            | 11 +++++++++++
 test/spec/ol/extent.test.js | 13 +++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/src/ol/extent.js b/src/ol/extent.js
index 7dad3efbd7..b1309b5ff8 100644
--- a/src/ol/extent.js
+++ b/src/ol/extent.js
@@ -48,6 +48,17 @@ ol.extent.boundingExtentXYs_ = function(xs, ys, opt_extent) {
 };
 
 
+/**
+ * Creates a clone of an extent.
+ *
+ * @param {ol.Extent} extent Extent to clone.
+ * @return {ol.Extent} The clone.
+ */
+ol.extent.clone = function(extent) {
+  return [[extent[0][0], extent[0][1]], [extent[1][0], extent[1][1]]];
+};
+
+
 /**
  * Checks if the passed coordinate is contained or on the edge of the extent.
  *
diff --git a/test/spec/ol/extent.test.js b/test/spec/ol/extent.test.js
index 6f8a5b3875..efb0368e1e 100644
--- a/test/spec/ol/extent.test.js
+++ b/test/spec/ol/extent.test.js
@@ -3,6 +3,19 @@ goog.provide('ol.test.extent');
 
 describe('ol.extent', function() {
 
+  describe('clone', function() {
+
+    it('creates a copy of an extent', function() {
+      var extent = ol.extent.createOrUpdate(1, 2, 3, 4);
+      var clone = ol.extent.clone(extent);
+      expect(ol.extent.equals(extent, clone)).to.be(true);
+
+      ol.extent.extendCoordinate(extent, [10, 20]);
+      expect(ol.extent.equals(extent, clone)).to.be(false);
+    });
+
+  });
+
   describe('containsCoordinate', function() {
 
     describe('positive', function() {