Adding tests for writing falsey values.

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

@@ -1303,6 +1303,27 @@ function testDataWriting() {
 		$this->assertEquals($request->data['Comment']['1']['author'], 'Mark');
 	}
 
+/**
+ * test writing falsey values.
+ *
+ * @return void
+ */
+	function testDataWritingFalsey() {
+		$request = new CakeRequest('posts/index');
+
+		$request->data('Post.null', null);
+		$this->assertNull($request->data['Post']['null']);
+
+		$request->data('Post.false', false);
+		$this->assertFalse($request->data['Post']['false']);
+
+		$request->data('Post.zero', 0);
+		$this->assertSame(0, $request->data['Post']['zero']);
+
+		$request->data('Post.empty', '');
+		$this->assertSame('', $request->data['Post']['empty']);
+	}
+
 /**
  * backupEnvironment method
  *