Fix incorrect CSRF token fields when using postLink()

Creating a postLink after creating a GET form would result in the
incorrect fields being generated.

Fixes #2308

lib/Cake/Test/Case/View/Helper/FormHelperTest.php

@@ -7173,6 +7173,35 @@ class FormHelperTest extends CakeTestCase {
 	}
 
 /**
+ * test creating postLinks after a GET form.
+ *
+ * @return void
+ */
+	public function testPostLinkAfterGetForm() {
+		$this->Form->request->params['_Token']['key'] = 'testkey';
+		$this->Form->create('User', array('type' => 'get'));
+		$this->Form->end();
+
+		$result = $this->Form->postLink('Delete', '/posts/delete/1');
+		$this->assertTags($result, array(
+			'form' => array(
+				'method' => 'post', 'action' => '/posts/delete/1',
+				'name' => 'preg:/post_\w+/', 'id' => 'preg:/post_\w+/', 'style' => 'display:none;'
+			),
+			array('input' => array('type' => 'hidden', 'name' => '_method', 'value' => 'POST')),
+			array('input' => array('type' => 'hidden', 'name' => 'data[_Token][key]', 'value' => 'testkey', 'id' => 'preg:/Token\d+/')),
+			'div' => array('style' => 'display:none;'),
+			array('input' => array('type' => 'hidden', 'name' => 'data[_Token][fields]', 'value' => 'preg:/[\w\d%]+/', 'id' => 'preg:/TokenFields\d+/')),
+			array('input' => array('type' => 'hidden', 'name' => 'data[_Token][unlocked]', 'value' => '', 'id' => 'preg:/TokenUnlocked\d+/')),
+			'/div',
+			'/form',
+			'a' => array('href' => '#', 'onclick' => 'preg:/document\.post_\w+\.submit\(\); event\.returnValue = false; return false;/'),
+			'Delete',
+			'/a'
+		));
+	}
+
+/**
  * Test that postLink adds _Token fields.
  *
  * @return void

lib/Cake/View/Helper/FormHelper.php

@@ -523,6 +523,7 @@ class FormHelper extends AppHelper {
 		$out .= $this->Html->useTag('formend');
 
 		$this->_View->modelScope = false;
+		$this->requestType = null;
 		return $out;
 	}