Proof of reorder bug

tests/GridFieldOrderableRowsTest.php

@@ -6,12 +6,44 @@ class GridFieldOrderableRowsTest extends SapphireTest {
 
 	protected $usesDatabase = true;
 
+	protected static $fixture_file = 'GridFieldOrderableRowsTest.yml';
+
 	protected $extraDataObjects = array(
 		'GridFieldOrderableRowsTest_Parent',
 		'GridFieldOrderableRowsTest_Ordered',
 		'GridFieldOrderableRowsTest_Subclass',
 	);
 
+	public function testReorderItems() {
+		$orderable = new GridFieldOrderableRows('ManyManySort');
+		$reflection = new ReflectionMethod($orderable, 'executeReorder');
+		$reflection->setAccessible(true);
+
+		$parent = $this->objFromFixture('GridFieldOrderableRowsTest_Parent', 'parent');
+
+		$config = new GridFieldConfig_RelationEditor();
+		$config->addComponent($orderable);
+
+		$grid = new GridField(
+			'MyManyMany',
+			'My Many Many',
+			$parent->MyManyMany()->sort('ManyManySort'),
+			$config
+		);
+
+		$originalOrder = $parent->MyManyMany()->sort('ManyManySort')->column('ID');
+		$desiredOrder = array_reverse($originalOrder);
+
+		$this->assertNotEquals($originalOrder, $desiredOrder);
+
+		$reflection->invoke($orderable, $grid, $desiredOrder);
+
+		$newOrder = $parent->MyManyMany()->sort('ManyManySort')->column('ID');
+
+		$this->assertEquals($desiredOrder, $newOrder);
+
+	}
+
 	/**
 	 * @covers GridFieldOrderableRows::getSortTable
 	 */

tests/GridFieldOrderableRowsTest.yml

@@ -0,0 +1,22 @@
+GridFieldOrderableRowsTest_Ordered:
+  item1:
+  item2:
+  item3:
+  item4:
+  item5:
+  item6:
+GridFieldOrderableRowsTest_Parent:
+  parent:
+    MyManyMany:
+      - 0: =>GridFieldOrderableRowsTest_Ordered.item1
+        ManyManySort: 1
+      - 1: =>GridFieldOrderableRowsTest_Ordered.item2
+        ManyManySort: 1
+      - 2: =>GridFieldOrderableRowsTest_Ordered.item3
+        ManyManySort: 2
+      - 3: =>GridFieldOrderableRowsTest_Ordered.item4
+        ManyManySort: 2
+      - 4: =>GridFieldOrderableRowsTest_Ordered.item5
+        ManyManySort: 108
+      - 5: =>GridFieldOrderableRowsTest_Ordered.item6
+        ManyManySort: 108