9 files changed, 97 insertions, 2 deletions
diff --git a/phpBB/includes/acp/acp_extensions.php b/phpBB/includes/acp/acp_extensions.php
index aba9caaece..9bdd8eb458 100644
--- a/phpBB/includes/acp/acp_extensions.php
+++ b/phpBB/includes/acp/acp_extensions.php
@@ -137,6 +137,12 @@ class acp_extensions
 					trigger_error($user->lang['EXTENSION_NOT_AVAILABLE'] . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
+				$extension = $phpbb_extension_manager->get_extension($ext_name);
+				if (!$extension->is_enableable())
+				{
+					trigger_error($user->lang['EXTENSION_NOT_ENABLEABLE'] . adm_back_link($this->u_action), E_USER_WARNING);
+				}
+
 				if ($phpbb_extension_manager->is_enabled($ext_name))
 				{
 					redirect($this->u_action);
@@ -162,6 +168,12 @@ class acp_extensions
 					trigger_error($user->lang['EXTENSION_NOT_AVAILABLE'] . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
+				$extension = $phpbb_extension_manager->get_extension($ext_name);
+				if (!$extension->is_enableable())
+				{
+					trigger_error($user->lang['EXTENSION_NOT_ENABLEABLE'] . adm_back_link($this->u_action), E_USER_WARNING);
+				}
+
 				if ($phpbb_extension_manager->is_enabled($ext_name))
 				{
 					redirect($this->u_action);
diff --git a/phpBB/language/en/acp/extensions.php b/phpBB/language/en/acp/extensions.php
index 6ec722bb78..28cdc8829d 100644
--- a/phpBB/language/en/acp/extensions.php
+++ b/phpBB/language/en/acp/extensions.php
@@ -42,6 +42,7 @@ $lang = array_merge($lang, array(
 	'EXTENSION_INVALID_LIST'	=> 'The “%s” extension is not valid.<br />%s<br /><br />',
 	'EXTENSION_NOT_AVAILABLE'	=> 'The selected extension is not available for this board, please verify your phpBB and PHP versions are allowed (see the details page).',
 	'EXTENSION_DIR_INVALID'		=> 'The selected extension has an invalid directory structure and cannot be enabled.',
+	'EXTENSION_NOT_ENABLEABLE'	=> 'The selected extension cannot be enabled, please verify the extension’s requirements.',
 
 	'DETAILS'				=> 'Details',
 
diff --git a/phpBB/phpbb/extension/base.php b/phpBB/phpbb/extension/base.php
index cbbd7bc622..288fb7d19c 100644
--- a/phpBB/phpbb/extension/base.php
+++ b/phpBB/phpbb/extension/base.php
@@ -40,6 +40,7 @@ class base implements \phpbb\extension\extension_interface
 	*
 	* @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 +55,14 @@ 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
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..5afec9ba82 100644
--- a/phpBB/phpbb/extension/manager.php
+++ b/phpBB/phpbb/extension/manager.php
@@ -177,6 +177,12 @@ 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/tests/extension/ext/vendor3/foo/composer.json b/tests/extension/ext/vendor3/foo/composer.json
new file mode 100644
index 0000000000..b4b3e6f32f
--- /dev/null
+++ b/tests/extension/ext/vendor3/foo/composer.json
@@ -0,0 +1,23 @@
+{
+	"name": "vendor3/foo",
+	"type": "phpbb-extension",
+	"description": "An example/sample extension to be used for testing purposes in phpBB Development.",
+	"version": "1.0.0",
+	"time": "2012-02-15 01:01:01",
+	"license": "GPL-2.0",
+	"authors": [{
+			"name": "John Smith",
+			"email": "email@phpbb.com",
+			"homepage": "http://phpbb.com",
+			"role": "N/A"
+		}],
+	"require": {
+		"php": ">=5.3"
+	},
+	"extra": {
+		"display-name": "phpBB Bar Extension",
+		"soft-require": {
+			"phpbb/phpbb": "3.1.*@dev"
+		}
+	}
+}
diff --git a/tests/extension/ext/vendor3/foo/ext.php b/tests/extension/ext/vendor3/foo/ext.php
new file mode 100644
index 0000000000..b52649d921
--- /dev/null
+++ b/tests/extension/ext/vendor3/foo/ext.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace vendor3\foo;
+
+class ext extends \phpbb\extension\base
+{
+	static public $enabled;
+
+	public function enable_step($old_state)
+	{
+		self::$enabled = true;
+
+		return self::$enabled;
+	}
+
+	public function is_enableable()
+	{
+		return false;
+	}
+}
diff --git a/tests/extension/manager_test.php b/tests/extension/manager_test.php
index 230c90c7c7..67e12e4260 100644
--- a/tests/extension/manager_test.php
+++ b/tests/extension/manager_test.php
@@ -13,6 +13,7 @@
 
 require_once dirname(__FILE__) . '/ext/vendor2/bar/ext.php';
 require_once dirname(__FILE__) . '/ext/vendor2/foo/ext.php';
+require_once dirname(__FILE__) . '/ext/vendor3/foo/ext.php';
 require_once dirname(__FILE__) . '/ext/vendor/moo/ext.php';
 
 class phpbb_extension_manager_test extends phpbb_database_test_case
@@ -35,7 +36,7 @@ class phpbb_extension_manager_test extends phpbb_database_test_case
 	public function test_all_available()
 	{
 		// barfoo and vendor3/bar should not listed due to missing composer.json. barfoo also has incorrect dir structure.
-		$this->assertEquals(array('vendor/moo', 'vendor2/bar', 'vendor2/foo'), array_keys($this->extension_manager->all_available()));
+		$this->assertEquals(array('vendor/moo', 'vendor2/bar', 'vendor2/foo', 'vendor3/foo'), array_keys($this->extension_manager->all_available()));
 	}
 
 	public function test_all_enabled()
@@ -100,6 +101,18 @@ class phpbb_extension_manager_test extends phpbb_database_test_case
 		$this->assertEquals(4, vendor2\bar\ext::$state);
 	}
 
+	public function test_enable_not_enableable()
+	{
+		vendor3\foo\ext::$enabled = false;
+
+		$this->assertEquals(array('vendor2/foo'), array_keys($this->extension_manager->all_enabled()));
+		$this->extension_manager->enable('vendor3/foo');
+		$this->assertEquals(array('vendor2/foo'), array_keys($this->extension_manager->all_enabled()));
+		$this->assertEquals(array('vendor/moo', 'vendor2/foo'), array_keys($this->extension_manager->all_configured()));
+
+		$this->assertSame(false, vendor3\foo\ext::$enabled);
+	}
+
 	public function test_disable()
 	{
 		vendor2\foo\ext::$disabled = false;
diff --git a/tests/functional/extension_acp_test.php b/tests/functional/extension_acp_test.php
index b6dd5db708..6490c1ead3 100644
--- a/tests/functional/extension_acp_test.php
+++ b/tests/functional/extension_acp_test.php
@@ -84,7 +84,7 @@ class phpbb_functional_extension_acp_test extends phpbb_functional_test_case
 		$crawler = self::request('GET', 'adm/index.php?i=acp_extensions&mode=main&sid=' . $this->sid);
 
 		$this->assertCount(1, $crawler->filter('.ext_enabled'));
-		$this->assertCount(4, $crawler->filter('.ext_disabled'));
+		$this->assertCount(5, $crawler->filter('.ext_disabled'));
 
 		$this->assertContains('phpBB Foo Extension', $crawler->filter('.ext_enabled')->eq(0)->text());
 		$this->assertContainsLang('EXTENSION_DISABLE', $crawler->filter('.ext_enabled')->eq(0)->text());
@@ -162,6 +162,10 @@ class phpbb_functional_extension_acp_test extends phpbb_functional_test_case
 
 		$crawler = self::request('GET', 'adm/index.php?i=acp_extensions&mode=main&action=enable_pre&ext_name=vendor%2Fmoo&sid=' . $this->sid);
 		$this->assertContains($this->lang('EXTENSION_ENABLE_CONFIRM', 'phpBB Moo Extension'), $crawler->filter('#main')->text());
+
+		// Correctly submit the enable form
+		$crawler = self::request('GET', 'adm/index.php?i=acp_extensions&mode=main&action=enable_pre&ext_name=vendor3%2Ffoo&sid=' . $this->sid);
+		$this->assertContainsLang('EXTENSION_NOT_ENABLEABLE', $crawler->filter('.errorbox')->text());
 	}
 
 	public function test_disable_pre()