Fix IN replacement in virtual fields for MYSQL.

lib/Cake/Model/Datasource/DboSource.php

@@ -1410,11 +1410,10 @@ public function fetchAssociated(Model $Model, $query, $ids) {
 	protected function _fetchHasMany(Model $Model, $query, $ids) {
 		$ids = array_unique($ids);
 
-		$query = str_replace('{$__cakeID__$}', implode(', ', $ids), $query);
 		if (count($ids) > 1) {
-			$query = str_replace('= (', 'IN (', $query);
+			$query = str_replace('= ({$__cakeID__$}', 'IN ({$__cakeID__$}', $query);
 		}
-
+		$query = str_replace('{$__cakeID__$}', implode(', ', $ids), $query);
 		return $this->fetchAll($query, $Model->cacheQueries);
 	}
 

lib/Cake/Test/Case/Model/Datasource/Database/MysqlTest.php

@@ -3427,6 +3427,31 @@ public function testVirtualFields() {
 		$this->assertEquals($expected, $result);
 	}
 
+/**
+ * test find() generating usable virtual fields to use in query
+ *
+ * @return void
+ */
+	public function testVirtualFieldsWithSubquery() {
+		$this->loadFixtures('Article', 'Comment', 'User', 'Tag', 'ArticlesTag');
+		$this->Dbo->virtualFieldSeparator = '__';
+		$Article = ClassRegistry::init('Article');
+		$commentsTable = $this->Dbo->fullTableName('comments', false, false);
+		$Article->Comment->virtualFields = array(
+			'extra' => 'SELECT id FROM ' . $commentsTable . ' WHERE id = (SELECT 1)',
+		);
+		$conditions = array('Article.id' => array(1, 2));
+		$contain = array('Comment.extra');
+		$result = $Article->find('all', compact('conditions', 'contain'));
+
+		$expected = 'SELECT `Comment`.`id`, `Comment`.`article_id`, `Comment`.`user_id`, `Comment`.`comment`, `Comment`.`published`, `Comment`.`created`,' .
+			' `Comment`.`updated`, (SELECT id FROM comments WHERE id = (SELECT 1)) AS  `Comment__extra`' .
+			' FROM `cake_test`.`comments` AS `Comment`   WHERE `Comment`.`article_id` IN (1, 2)';
+		$test = ConnectionManager::getDatasource('test');
+		$log = $test->getLog();
+		$this->assertTextEquals($expected, $log['log'][116]['query']);
+	}
+
 /**
  * test conditions to generate query conditions for virtual fields
  *