Add support for JsonSerializable.

Fix issues with deserializing ResultSets, where a `false` would be
appended to the stored results.

lib/Cake/ORM/ResultSet.php

@@ -18,6 +18,7 @@
 
 use Cake\Database\Type;
 use \Iterator;
+use \JsonSerializable;
 use \Serializable;
 
 /**
@@ -27,7 +28,7 @@
  * queries required for eager loading external associations.
  *
  */
-class ResultSet implements Iterator, Serializable {
+class ResultSet implements Iterator, Serializable, JsonSerializable {
 
 /**
  * Original query from where results where generated
@@ -200,20 +201,21 @@ protected function _calculateAssociationMap() {
  * @return void
  */
 	protected function _fetchResult() {
-		$advance = ($this->_lastIndex < $this->_index);
-		if (!$advance) {
-			return;
-		}
 		if (isset($this->_results[$this->_index])) {
 			$this->_current = $this->_results[$this->_index];
+			$this->_lastIndex = $this->_index;
+			return;
+		}
+		if (!$this->_statement) {
+			$this->_current = false;
 			return;
 		}
 		$row = $this->_statement->fetch('assoc');
 		if ($row !== false) {
 			$row = $this->_groupResult($row);
+			$this->_results[] = $row;
 		}
 		$this->_current = $row;
-		$this->_results[] = $row;
 		$this->_lastIndex = $this->_index;
 	}
 
@@ -290,26 +292,37 @@ protected function _castValues($table, $values) {
 /**
  * Serialize a resultset.
  *
- * Part of Serializable Interface
+ * Part of Serializable interface.
  *
  * @return string Serialized object
  */
 	public function serialize() {
-		iterator_to_array($this);
+		$this->toArray();
 		return serialize($this->_results);
 	}
 
 /**
  * Unserialize a resultset.
  *
- * Part of Serializable Interface
+ * Part of Serializable interface.
  *
  * @param string Serialized object
  * @return ResultSet The hydrated result set.
  */
 	public function unserialize($serialized) {
 		$this->_results = unserialize($serialized);
-		return $this;
+	}
+
+/**
+ * Convert a result set into JSON.
+ *
+ * Part of JsonSerializable interface.
+ *
+ * @return array The data to convert to JSON
+ */
+	public function jsonSerialize() {
+		$this->toArray();
+		return $this->_results;
 	}
 
 }

lib/Cake/Test/TestCase/ORM/ResultSetTest.php

@@ -34,6 +34,12 @@ public function setUp() {
 		parent::setUp();
 		$this->connection = ConnectionManager::getDataSource('test');
 		$this->table = new Table(['table' => 'articles', 'connection' => $this->connection]);
+
+		$this->fixtureData = [
+			['id' => 1, 'author_id' => 1, 'title' => 'First Article', 'body' => 'First Article Body', 'published' => 'Y'],
+			['id' => 2, 'author_id' => 3, 'title' => 'Second Article', 'body' => 'Second Article Body', 'published' => 'Y'],
+			['id' => 3, 'author_id' => 1, 'title' => 'Third Article', 'body' => 'Third Article Body', 'published' => 'Y']
+		];
 	}
 
 /**
@@ -83,15 +89,23 @@ public function testIteratorAfterSerialization() {
 		$query = $this->table->find('all');
 		$results = unserialize(serialize($query->execute()));
 
-		$expected = [
-			['id' => 1, 'author_id' => 1, 'title' => 'First Article', 'body' => 'First Article Body', 'published' => 'Y'],
-			['id' => 2, 'author_id' => 3, 'title' => 'Second Article', 'body' => 'Second Article Body', 'published' => 'Y'],
-			['id' => 3, 'author_id' => 1, 'title' => 'Third Article', 'body' => 'Third Article Body', 'published' => 'Y']
-		];
 		// Use a loop to test Iterator implementation
 		foreach ($results as $i => $row) {
-			$this->assertEquals($expected[$i], $row, "Row $i does not match");
+			$this->assertEquals($this->fixtureData[$i], $row, "Row $i does not match");
 		}
 	}
 
+/**
+ * Test converting resultsets into json
+ *
+ * @return void
+ */
+	public function testJsonSerialize() {
+		$query = $this->table->find('all');
+		$results = $query->execute();
+
+		$expected = json_encode($this->fixtureData);
+		$this->assertEquals(json_encode($results), $expected);
+	}
+
 }