Allow datasource access in constructors of mocked models.

When mock objects are created from models that access their datasource
in the constructor, an exception would be raised for the missing default
datasource. By changing how configuration data is handled in the mock
creation we can avoid this issue and not reopen #4867

Refs #8225

lib/Cake/Test/Case/TestSuite/CakeTestCaseTest.php

@@ -39,6 +39,22 @@ class SecondaryPost extends Model {
 
 }
 
+/**
+ * ConstructorPost test stub.
+ */
+class ConstructorPost extends Model {
+
+/**
+ * @var string
+ */
+	public $useTable = 'posts';
+
+	public function __construct($id = false, $table = null, $ds = null) {
+		parent::__construct($id, $table, $ds);
+		$this->getDataSource()->cacheMethods = false;
+	}
+}
+
 /**
  * CakeTestCaseTest
  *
@@ -435,6 +451,16 @@ public function testGetMockForModelSecondaryDatasource() {
 		ConnectionManager::drop('test_secondary');
 	}
 
+/**
+ * Test getMockForModel when the model accesses the datasource in the constructor.
+ *
+ * @return void
+ */
+	public function testGetMockForModelConstructorDatasource() {
+		$post = $this->getMockForModel('ConstructorPost', array('save'), array('ds' => 'test'));
+		$this->assertEquals('test', $post->useDbConfig);
+	}
+
 /**
  * test getMockForModel() with plugin models
  *

lib/Cake/TestSuite/CakeTestCase.php

@@ -718,13 +718,13 @@ protected function skipUnless($condition, $message = '') {
  * @return Model
  */
 	public function getMockForModel($model, $methods = array(), $config = array()) {
-		$config += ClassRegistry::config('Model');
+		$defaults = ClassRegistry::config('Model');
+		unset($defaults['ds']);
 
 		list($plugin, $name) = pluginSplit($model, true);
 		App::uses($name, $plugin . 'Model');
 
-		$config = array_merge((array)$config, array('name' => $name));
-		unset($config['ds']);
+		$config = array_merge($defaults, (array)$config, array('name' => $name));
 
 		if (!class_exists($name)) {
 			throw new MissingModelException(array($model));