Fix sortDir() to read default params.

sortDir() also did not reflect the default paging parameters.
This would result in initial links not matching the query used.

Fixes #2640

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

@@ -384,6 +384,15 @@ class PaginatorHelperTest extends CakeTestCase {
 
 		$result = $this->Paginator->sortKey('Article');
 		$this->assertEquals('Article.body', $result);
+
+		$this->Paginator->request->params['paging']['Article']['order'] = array(
+			'Article.body' => 'DESC'
+		);
+		$result = $this->Paginator->sortKey();
+		$this->assertEquals('Article.body', $result);
+
+		$result = $this->Paginator->sortKey('Article');
+		$this->assertEquals('Article.body', $result);
 	}
 
 /**
@@ -455,6 +464,32 @@ class PaginatorHelperTest extends CakeTestCase {
 		$this->assertEquals($expected, $result);
 	}
 
+/**
+ * Test that sortDir falls back to the default sorting options set
+ * in the $params which are the default pagination options.
+ *
+ * @return void
+ */
+	public function testSortDirFallbackToParams() {
+		$this->Paginator->request->params['paging']['Article']['order'] = array(
+			'Article.body' => 'ASC'
+		);
+		$result = $this->Paginator->sortDir();
+		$this->assertEquals('asc', $result);
+
+		$result = $this->Paginator->sortDir('Article');
+		$this->assertEquals('asc', $result);
+
+		$this->Paginator->request->params['paging']['Article']['order'] = array(
+			'Article.body' => 'DESC'
+		);
+		$result = $this->Paginator->sortDir();
+		$this->assertEquals('desc', $result);
+
+		$result = $this->Paginator->sortDir('Article');
+		$this->assertEquals('desc', $result);
+	}
+
 /**
  * testSortAdminLinks method
  *

lib/Cake/View/Helper/PaginatorHelper.php

@@ -232,6 +232,8 @@ class PaginatorHelper extends AppHelper {
 			$dir = strtolower($options['direction']);
 		} elseif (isset($options['order']) && is_array($options['order'])) {
 			$dir = strtolower(current($options['order']));
+		} elseif (isset($params['order']) && is_array($params['order'])) {
+			$dir = strtolower(current($params['order']));
 		}
 
 		if ($dir == 'desc') {