4 files changed, 31 insertions, 27 deletions
diff --git a/phpBB/phpbb/extension/base.php b/phpBB/phpbb/extension/base.php
index cbbd7bc622..5bb530bad4 100644
--- a/phpBB/phpbb/extension/base.php
+++ b/phpBB/phpbb/extension/base.php
@@ -35,11 +35,15 @@ class base implements \phpbb\extension\extension_interface
 	/** @var string */
 	protected $extension_path;
 
+	/** @var string[] */
+	private $migrations = false;
+
 	/**
 	* Constructor
 	*
 	* @param ContainerInterface $container Container object
 	* @param \phpbb\finder $extension_finder
+	* @param \phpbb\db\migrator $migrator
 	* @param string $extension_name Name of this extension (from ext.manager)
 	* @param string $extension_path Relative path to this extension
 	*/
@@ -54,6 +58,14 @@ class base implements \phpbb\extension\extension_interface
 	}
 
 	/**
+	* {@inheritdoc}
+	*/
+	public function is_enableable()
+	{
+		return true;
+	}
+
+	/**
 	* Single enable step that installs any included migrations
 	*
 	* @param mixed $old_state State returned by previous call of this method
@@ -113,17 +125,16 @@ class base implements \phpbb\extension\extension_interface
 	*/
 	protected function get_migration_file_list()
 	{
-		static $migrations = false;
-
-		if ($migrations !== false)
+		if ($this->migrations !== false)
 		{
-			return $migrations;
+			return $this->migrations;
 		}
 
 		// Only have the finder search in this extension path directory
 		$migrations = $this->extension_finder
 			->extension_directory('/migrations')
 			->find_from_extension($this->extension_name, $this->extension_path);
+
 		$migrations = $this->extension_finder->get_classes_from_files($migrations);
 
 		return $migrations;
diff --git a/phpBB/phpbb/extension/extension_interface.php b/phpBB/phpbb/extension/extension_interface.php
index cc8b8be980..6a6b6adb8f 100644
--- a/phpBB/phpbb/extension/extension_interface.php
+++ b/phpBB/phpbb/extension/extension_interface.php
@@ -20,6 +20,13 @@ namespace phpbb\extension;
 interface extension_interface
 {
 	/**
+	* Indicate whether or not the extension can be enabled.
+	*
+	* @return bool
+	*/
+	public function is_enableable();
+
+	/**
 	* enable_step is executed on enabling an extension until it returns false.
 	*
 	* Calls to this function can be made in subsequent requests, when the
diff --git a/phpBB/phpbb/extension/manager.php b/phpBB/phpbb/extension/manager.php
index b19eb9f8a3..76f0e3558e 100644
--- a/phpBB/phpbb/extension/manager.php
+++ b/phpBB/phpbb/extension/manager.php
@@ -77,11 +77,12 @@ class manager
 	{
 		$this->extensions = array();
 
-		// Do not try to load any extensions when installing or updating
+		// Do not try to load any extensions if the extension table
+		// does not exist or when installing or updating.
 		// Note: database updater invokes this code, and in 3.0
 		// there is no extension table therefore the rest of this function
 		// fails
-		if (defined('IN_INSTALL'))
+		if (defined('IN_INSTALL') || version_compare($this->config['version'], '3.1.0-dev', '<'))
 		{
 			return;
 		}
@@ -177,6 +178,12 @@ class manager
 		$old_state = (isset($this->extensions[$name]['ext_state'])) ? unserialize($this->extensions[$name]['ext_state']) : false;
 
 		$extension = $this->get_extension($name);
+
+		if (!$extension->is_enableable())
+		{
+			return false;
+		}
+
 		$state = $extension->enable_step($old_state);
 
 		$active = ($state === false);
diff --git a/phpBB/phpbb/extension/metadata_manager.php b/phpBB/phpbb/extension/metadata_manager.php
index 1051021ea7..edca8ee1af 100644
--- a/phpBB/phpbb/extension/metadata_manager.php
+++ b/phpBB/phpbb/extension/metadata_manager.php
@@ -330,27 +330,6 @@ class metadata_manager
 	}
 
 	/**
-	* Version validation helper
-	*
-	* @param string $string The string for comparing to a version
-	* @param string $current_version The version to compare to
-	* @return bool True/False if meets version requirements
-	*/
-	private function _validate_version($string, $current_version)
-	{
-		// Allow them to specify their own comparison operator (ex: <3.1.2, >=3.1.0)
-		$comparison_matches = false;
-		preg_match('#[=<>]+#', $string, $comparison_matches);
-
-		if (!empty($comparison_matches))
-		{
-			return version_compare($current_version, str_replace(array($comparison_matches[0], ' '), '', $string), $comparison_matches[0]);
-		}
-
-		return version_compare($current_version, $string, '>=');
-	}
-
-	/**
 	* Outputs the metadata into the template
 	*
 	* @return null