Removing duplicate START TRANSACTION sql execution in mysqli environm…

…ent, fixes #6422

git-svn-id: https://svn.cakephp.org/repo/branches/1.2.x.x@8191 3807eeeb-6ff5-0310-8944-8be069107fe0

cake/libs/model/datasources/dbo/dbo_mysqli.php

@@ -232,20 +232,6 @@ function value($data, $column = null, $safe = false) {
 
 		return $data;
 	}
-/**
- * Begin a transaction
- *
- * @param unknown_type $model
- * @return boolean True on success, false on fail
- * (i.e. if the database/model does not support transactions).
- */
-	function begin(&$model) {
-		if (parent::begin($model) && $this->execute('START TRANSACTION')) {
-			$this->_transactionStarted = true;
-			return true;
-		}
-		return false;
-	}
 /**
  * Returns a formatted error message from previous database operation.
  *

cake/tests/cases/libs/model/datasources/dbo/dbo_mysqli.test.php

@@ -297,5 +297,21 @@ function testColumn() {
 		$expected = 'float';
 		$this->assertEqual($result, $expected);
 	}
+/**
+ * undocumented function
+ *
+ * @return void
+ * @access public
+ */
+	function testTransactions() {
+		$this->db->begin($this->model);
+		$this->assertTrue($this->db->_transactionStarted);
+
+		$beginSqlCalls = Set::extract('/.[query=START TRANSACTION]', $this->db->_queriesLog);
+		$this->assertEqual(1, count($beginSqlCalls));
+
+		$this->db->commit($this->model);
+		$this->assertFalse($this->db->_transactionStarted);
+	}
 }
 ?>