Fixing Set::sort() for arrays with out of sequence, or missing keys.

Tests added.
Fixes #1312

cake/libs/set.php

@@ -1092,6 +1092,10 @@ function __flatten($results, $key = null) {
  * @static
  */
 	function sort($data, $path, $dir) {
+		$originalKeys = array_keys($data);
+		if (is_numeric(implode('', $originalKeys))) {
+			$data = array_values($data);
+		}
 		$result = Set::__flatten(Set::extract($data, $path));
 		list($keys, $values) = array(Set::extract($result, '{n}.id'), Set::extract($result, '{n}.value'));
 
@@ -1103,7 +1107,6 @@ function sort($data, $path, $dir) {
 		}
 		array_multisort($values, $dir, $keys, $dir);
 		$sorted = array();
-
 		$keys = array_unique($keys);
 
 		foreach ($keys as $k) {

cake/tests/cases/libs/set.test.php

@@ -354,6 +354,33 @@ function testSort() {
 		$this->assertEqual($result, $expected);
 	}
 
+/**
+ * test sorting with out of order keys.
+ *
+ * @return void
+ */
+	function testSortWithOutOfOrderKeys() {
+		$data = array(
+			9 => array('class' => 510, 'test2' => 2),
+			1 => array('class' => 500, 'test2' => 1),
+			2 => array('class' => 600, 'test2' => 2),
+			5 => array('class' => 625, 'test2' => 4),
+			0 => array('class' => 605, 'test2' => 3),
+		);
+		$expected = array(
+			array('class' => 500, 'test2' => 1),
+			array('class' => 510, 'test2' => 2),
+			array('class' => 600, 'test2' => 2),
+			array('class' => 605, 'test2' => 3),
+			array('class' => 625, 'test2' => 4),
+		);
+		$result = Set::sort($data, '{n}.class', 'asc');
+		$this->assertEqual($expected, $result);
+
+		$result = Set::sort($data, '{n}.test2', 'asc');
+		$this->assertEqual($expected, $result);
+	}
+
 /**
  * testExtract method
  *