8 files changed, 240 insertions, 15 deletions
diff --git a/phpBB/includes/db/migration/tool/config.php b/phpBB/includes/db/migration/tool/config.php
index e7239436d2..6ae419d5e7 100644
--- a/phpBB/includes/db/migration/tool/config.php
+++ b/phpBB/includes/db/migration/tool/config.php
@@ -103,4 +103,46 @@ class phpbb_db_migration_tool_config implements phpbb_db_migration_tool_interfac
 
 		$this->config->delete($config_name);
 	}
+
+	/**
+	* Reverse an original install action
+	*
+	* First argument is the original call to the class (e.g. add, remove)
+	* After the first argument, send the original arguments to the function in the original call
+	*
+	* @return null
+	*/
+	public function reverse()
+	{
+		$arguments = func_get_args();
+		$original_call = array_shift($arguments);
+
+		$call = false;
+		switch ($original_call)
+		{
+			case 'add':
+				$call = 'remove';
+			break;
+
+			case 'remove':
+				$call = 'add';
+			break;
+
+			case 'update_if_equals':
+				$call = 'update_if_equals';
+
+				// Set to the original value if the current value is what we compared to originally
+				$arguments = array(
+					$arguments[2],
+					$arguments[1],
+					$arguments[0],
+				);
+			break;
+		}
+
+		if ($call)
+		{
+			return call_user_func_array(array(&$this, $call), $arguments);
+		}
+	}
 }
diff --git a/phpBB/includes/db/migration/tool/interface.php b/phpBB/includes/db/migration/tool/interface.php
index 5d10246ba1..ced53b2023 100644
--- a/phpBB/includes/db/migration/tool/interface.php
+++ b/phpBB/includes/db/migration/tool/interface.php
@@ -20,4 +20,14 @@ interface phpbb_db_migration_tool_interface
 	* @return string short name
 	*/
 	public function get_name();
+
+	/**
+	* Reverse an original install action
+	*
+	* First argument is the original call to the class (e.g. add, remove)
+	* After the first argument, send the original arguments to the function in the original call
+	*
+	* @return null
+	*/
+	public function reverse();
 }
diff --git a/phpBB/includes/db/migration/tool/module.php b/phpBB/includes/db/migration/tool/module.php
index 70a246849a..561faac552 100644
--- a/phpBB/includes/db/migration/tool/module.php
+++ b/phpBB/includes/db/migration/tool/module.php
@@ -471,4 +471,35 @@ class phpbb_db_migration_tool_module implements phpbb_db_migration_tool_interfac
 			$this->cache->destroy("_modules_$class");
 		}
 	}
+
+	/**
+	* Reverse an original install action
+	*
+	* First argument is the original call to the class (e.g. add, remove)
+	* After the first argument, send the original arguments to the function in the original call
+	*
+	* @return null
+	*/
+	public function reverse()
+	{
+		$arguments = func_get_args();
+		$original_call = array_shift($arguments);
+
+		$call = false;
+		switch ($original_call)
+		{
+			case 'add':
+				$call = 'remove';
+			break;
+
+			case 'remove':
+				$call = 'add';
+			break;
+		}
+
+		if ($call)
+		{
+			return call_user_func_array(array(&$this, $call), $arguments);
+		}
+	}
 }
diff --git a/phpBB/includes/db/migration/tool/permission.php b/phpBB/includes/db/migration/tool/permission.php
index 7b45b24361..a25fdb345e 100644
--- a/phpBB/includes/db/migration/tool/permission.php
+++ b/phpBB/includes/db/migration/tool/permission.php
@@ -563,4 +563,59 @@ class phpbb_db_migration_tool_permission implements phpbb_db_migration_tool_inte
 
 		$this->auth->acl_clear_prefetch();
 	}
+
+	/**
+	* Reverse an original install action
+	*
+	* First argument is the original call to the class (e.g. add, remove)
+	* After the first argument, send the original arguments to the function in the original call
+	*
+	* @return null
+	*/
+	public function reverse()
+	{
+		$arguments = func_get_args();
+		$original_call = array_shift($arguments);
+
+		$call = false;
+		switch ($original_call)
+		{
+			case 'add':
+				$call = 'remove';
+			break;
+
+			case 'remove':
+				$call = 'add';
+			break;
+
+			case 'permission_set':
+				$call = 'permission_unset';
+			break;
+
+			case 'permission_unset':
+				$call = 'permission_set';
+			break;
+
+			case 'role_add':
+				$call = 'role_remove';
+			break;
+
+			case 'role_remove':
+				$call = 'role_add';
+			break;
+
+			case 'role_update':
+				// Set to the original value if the current value is what we compared to originally
+				$arguments = array(
+					$arguments[1],
+					$arguments[0],
+				);
+			break;
+		}
+
+		if ($call)
+		{
+			return call_user_func_array(array(&$this, $call), $arguments);
+		}
+	}
 }
diff --git a/phpBB/includes/db/migrator.php b/phpBB/includes/db/migrator.php
index 359c34bf5d..dc2c746559 100644
--- a/phpBB/includes/db/migrator.php
+++ b/phpBB/includes/db/migrator.php
@@ -347,6 +347,17 @@ class phpbb_db_migrator
 			catch (phpbb_db_migration_exception $e)
 			{
 				// We should try rolling back here
+				foreach ($steps as $reverse_step)
+				{
+					// Reverse the step that was run
+					$result = $this->run_step($step, false, true);
+
+					// If we've reached the current step we can break because we reversed everything that was run
+					if ($reverse_step === $step)
+					{
+						break;
+					}
+				}
 
 				var_dump($step);
 				echo $e;
@@ -364,11 +375,12 @@ class phpbb_db_migrator
 	*
 	* @param mixed $step Data step from migration
 	* @param mixed $last_result Result to pass to the callable (only for 'custom' method)
+	* @param bool $reverse False to install, True to attempt uninstallation by reversing the call
 	* @return null
 	*/
-	protected function run_step($step, $last_result = false)
+	protected function run_step($step, $last_result = false, $reverse = false)
 	{
-		$callable_and_parameters = $this->get_callable_from_step($step, $last_result);
+		$callable_and_parameters = $this->get_callable_from_step($step, $last_result, $reverse);
 
 		if ($callable_and_parameters === false)
 		{
@@ -386,9 +398,10 @@ class phpbb_db_migrator
 	*
 	* @param mixed $step Data step from migration
 	* @param mixed $last_result Result to pass to the callable (only for 'custom' method)
+	* @param bool $reverse False to install, True to attempt uninstallation by reversing the call
 	* @return array Array with parameters for call_user_func_array(), 0 is the callable, 1 is parameters
 	*/
-	protected function get_callable_from_step($step, $last_result = false)
+	protected function get_callable_from_step($step, $last_result = false, $reverse = false)
 	{
 		$type = $step[0];
 		$parameters = $step[1];
@@ -425,14 +438,7 @@ class phpbb_db_migrator
 
 				$step = $parameters[1];
 
-				$callable_and_parameters = $this->get_callable_from_step($step);
-				$callable = $callable_and_parameters[0];
-				$sub_parameters = $callable_and_parameters[1];
-
-				return array(
-					$callable,
-					$sub_parameters,
-				);
+				return $this->get_callable_from_step($step);
 			break;
 			case 'custom':
 				if (!is_callable($parameters[0]))
@@ -462,6 +468,15 @@ class phpbb_db_migrator
 					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_UNDEFINED_METHOD', $step);
 				}
 
+				// Attempt to reverse operations
+				if ($reverse)
+				{
+					return array(
+						array($this->tools[$class], 'reverse'),
+						array_unshift($parameters, $method),
+					);
+				}
+
 				return array(
 					array($this->tools[$class], $method),
 					$parameters,
diff --git a/tests/dbal/migrator_tool_config_test.php b/tests/dbal/migrator_tool_config_test.php
index 27511519ca..7d582f230b 100644
--- a/tests/dbal/migrator_tool_config_test.php
+++ b/tests/dbal/migrator_tool_config_test.php
@@ -94,4 +94,31 @@ class phpbb_dbal_migrator_tool_config_test extends phpbb_test_case
 		}
 		$this->assertFalse(isset($this->config['foo']));
 	}
+
+	public function test_reverse()
+	{
+		$this->config->set('foo', 'bar');
+
+		try
+		{
+			$this->tool->reverse('add', 'foo');
+		}
+		catch (Exception $e)
+		{
+			$this->fail($e);
+		}
+		$this->assertFalse(isset($this->config['foo']));
+
+		$this->config->set('foo', 'bar');
+
+		try
+		{
+			$this->tool->reverse('update_if_equals', 'test', 'foo', 'bar');
+		}
+		catch (Exception $e)
+		{
+			$this->fail($e);
+		}
+		$this->assertEquals('test', $this->config['foo']);
+	}
 }
diff --git a/tests/dbal/migrator_tool_module.php b/tests/dbal/migrator_tool_module.php
index 0b57cbfbcb..6937b6f8c5 100644
--- a/tests/dbal/migrator_tool_module.php
+++ b/tests/dbal/migrator_tool_module.php
@@ -29,10 +29,10 @@ class phpbb_dbal_migrator_tool_module_test extends phpbb_database_test_case
 		$skip_add_log = true;
 
 		$db = $this->db = $this->new_dbal();
-		$this->cache = new phpbb_cache_service(new phpbb_cache_driver_null());
+		$this->cache = new phpbb_cache_service(new phpbb_cache_driver_null(), new phpbb_config(array()), $this->db, $phpbb_root_path, $phpEx);
 		$user = $this->user = new phpbb_user();
 
-		$this->tool = new phpbb_db_migration_tool_module($this->db, $this->cache, $this->user, $phpbb_root_path, $phpEx);
+		$this->tool = new phpbb_db_migration_tool_module($this->db, $this->cache, $this->user, $phpbb_root_path, $phpEx, 'phpbb_modules');
 	}
 
 	public function exists_data()
@@ -99,7 +99,7 @@ class phpbb_dbal_migrator_tool_module_test extends phpbb_database_test_case
 
 		try
 		{
-			$this->tool->add('acp', ACP_NEW_CAT, array(
+			$this->tool->add('acp', 'ACP_NEW_CAT', array(
 				'module_basename'	=> 'acp_new_module',
 				'module_langname'	=> 'ACP_NEW_MODULE',
 				'module_mode'		=> 'test',
@@ -125,4 +125,26 @@ class phpbb_dbal_migrator_tool_module_test extends phpbb_database_test_case
 		}
 		$this->assertEquals(false, $this->tool->exists('acp', 'ACP_CAT', 'ACP_MODULE'));
 	}
+
+	public function test_reverse()
+	{
+		try
+		{
+			$this->tool->add('acp', 0, 'ACP_NEW_CAT');
+		}
+		catch (Exception $e)
+		{
+			$this->fail($e);
+		}
+
+		try
+		{
+			$this->tool->reverse('add', 'acp', 0, 'ACP_NEW_CAT');
+		}
+		catch (Exception $e)
+		{
+			$this->fail($e);
+		}
+		$this->assertFalse($this->tool->exists('acp', 0, 'ACP_NEW_CAT'));
+	}
 }
diff --git a/tests/dbal/migrator_tool_permission.php b/tests/dbal/migrator_tool_permission.php
index 2229576cd9..438ab2b28e 100644
--- a/tests/dbal/migrator_tool_permission.php
+++ b/tests/dbal/migrator_tool_permission.php
@@ -26,7 +26,7 @@ class phpbb_dbal_migrator_tool_permission_test extends phpbb_database_test_case
 		parent::setup();
 
 		$db = $this->db = $this->new_dbal();
-		$cache = $this->cache = new phpbb_cache_service(new phpbb_cache_driver_null());
+		$cache = $this->cache = new phpbb_cache_service(new phpbb_cache_driver_null(), new phpbb_config(array()), $this->db, $phpbb_root_path, $phpEx);
 		$this->auth = new phpbb_auth();
 
 		$this->tool = new phpbb_db_migration_tool_permission($this->db, $this->cache, $this->auth, $phpbb_root_path, $phpEx);
@@ -133,4 +133,27 @@ class phpbb_dbal_migrator_tool_permission_test extends phpbb_database_test_case
 		}
 		catch (Exception $e) {}
 	}
+
+	public function test_reverse()
+	{
+		try
+		{
+			$this->tool->reverse('remove', 'global_test', true);
+		}
+		catch (Exception $e)
+		{
+			$this->fail($e);
+		}
+		$this->assertTrue($this->tool->exists('global_test', true));
+
+		try
+		{
+			$this->tool->reverse('add', 'global_test', true);
+		}
+		catch (Exception $e)
+		{
+			$this->fail($e);
+		}
+		$this->assertFalse($this->tool->exists('global_test', true));
+	}
 }