Fixes #316 : set return null for HydratingResultSet::current() on no data

CHANGELOG.md

@@ -11,7 +11,7 @@ All notable changes to this project will be documented in this file, in reverse
 
 ### Changed
 
-- Nothing.
+- [#325](https://github.com/zendframework/zend-db/pull/325) change `HydratingResultSet::current()` to returns null on no data.
 
 ### Deprecated
 
@@ -425,4 +425,4 @@ All notable changes to this project will be documented in this file, in reverse
   closure binding (now that we're on 5.5+, this is possible).
 - [#9](https://github.com/zendframework/zend-db/pull/9) thoroughly audits the
   OCI8 (Oracle) driver, ensuring it provides feature parity with other drivers,
-  and fixes issues with subselects, limits, and offsets.
+  and fixes issues with subselects, limits, and offsets.

src/ResultSet/HydratingResultSet.php

@@ -90,7 +90,7 @@ public function getHydrator()
     /**
      * Iterator: get current item
      *
-     * @return object
+     * @return object|null
      */
     public function current()
     {
@@ -99,14 +99,14 @@ public function current()
         } elseif (is_array($this->buffer) && isset($this->buffer[$this->position])) {
             return $this->buffer[$this->position];
         }
-        $data = $this->dataSource->current();
-        $object = is_array($data) ? $this->hydrator->hydrate($data, clone $this->objectPrototype) : false;
+        $data    = $this->dataSource->current();
+        $current = is_array($data) ? $this->hydrator->hydrate($data, clone $this->objectPrototype) : null;
 
         if (is_array($this->buffer)) {
-            $this->buffer[$this->position] = $object;
+            $this->buffer[$this->position] = $current;
         }
 
-        return $object;
+        return $current;
     }
 
     /**

test/unit/ResultSet/HydratingResultSetTest.php

@@ -56,7 +56,7 @@ public function testGetHydrator()
     /**
      * @covers \Zend\Db\ResultSet\HydratingResultSet::current
      */
-    public function testCurrent()
+    public function testCurrentHasData()
     {
         $hydratingRs = new HydratingResultSet;
         $hydratingRs->initialize([
@@ -66,6 +66,17 @@ public function testCurrent()
         self::assertInstanceOf('ArrayObject', $obj);
     }
 
+    /**
+     * @covers \Zend\Db\ResultSet\HydratingResultSet::current
+     */
+    public function testCurrentDoesnotHasData()
+    {
+        $hydratingRs = new HydratingResultSet;
+        $hydratingRs->initialize([]);
+        $result = $hydratingRs->current();
+        self::assertNull($result);
+    }
+
     /**
      * @covers \Zend\Db\ResultSet\HydratingResultSet::toArray
      * @todo   Implement testToArray().