1 files changed, 52 insertions, 5 deletions

diff --git a/engine/lib/plugins.php b/engine/lib/plugins.php
index f281b1416..d5d3db466 100644
--- a/engine/lib/plugins.php
+++ b/engine/lib/plugins.php
@@ -312,10 +312,10 @@ function elgg_is_active_plugin($plugin_id, $site_guid = null) {
  */
 function elgg_load_plugins() {
 	$plugins_path = elgg_get_plugins_path();
-	$start_flags =	ELGG_PLUGIN_INCLUDE_START
-					| ELGG_PLUGIN_REGISTER_VIEWS
-					| ELGG_PLUGIN_REGISTER_LANGUAGES
-					| ELGG_PLUGIN_REGISTER_CLASSES;
+	$start_flags = ELGG_PLUGIN_INCLUDE_START |
+					ELGG_PLUGIN_REGISTER_VIEWS |
+					ELGG_PLUGIN_REGISTER_LANGUAGES |
+					ELGG_PLUGIN_REGISTER_CLASSES;
 
 	if (!$plugins_path) {
 		return false;
@@ -865,7 +865,7 @@ function elgg_set_plugin_user_setting($name, $value, $user_guid = null, $plugin_
  * Unsets a user-specific plugin setting
  *
  * @param string $name      Name of the setting
- * @param int $user_guid Defaults to logged in user
+ * @param int    $user_guid Defaults to logged in user
  * @param string $plugin_id Defaults to contextual plugin name
  *
  * @return bool
@@ -1105,6 +1105,49 @@ function plugins_test($hook, $type, $value, $params) {
 }
 
 /**
+ * Checks on deactivate plugin event if disabling it won't create unmet dependencies and blocks disable in such case.
+ *
+ * @param string $event  deactivate
+ * @param string $type   plugin
+ * @param array  $params Parameters array containing entry with ELggPlugin instance under 'plugin_entity' key
+ * @return bool  false to block plugin deactivation action
+ *
+ * @access private
+ */
+function _plugins_deactivate_dependency_check($event, $type, $params) {
+	$plugin_id = $params['plugin_entity']->getManifest()->getPluginID();
+	$plugin_name = $params['plugin_entity']->getManifest()->getName();
+
+	$active_plugins = elgg_get_plugins();
+
+	$dependents = array();
+	foreach ($active_plugins as $plugin) {
+		$manifest = $plugin->getManifest();
+		$requires = $manifest->getRequires();
+
+		foreach ($requires as $required) {
+			if ($required['type'] == 'plugin' && $required['name'] == $plugin_id) {
+				// there are active dependents
+				$dependents[$manifest->getPluginID()] = $plugin;
+			}
+		}
+	}
+
+	if ($dependents) {
+		$list = '<ul>';
+		// construct error message and prevent disabling
+		foreach ($dependents as $dependent) {
+			$list .= '<li>' . $dependent->getManifest()->getName() . '</li>';
+		}
+		$list .= '</ul>';
+
+		register_error(elgg_echo('ElggPlugin:Dependencies:ActiveDependent', array($plugin_name, $list)));
+
+		return false;
+	}
+}
+
+/**
  * Initialize the plugin system
  * Listens to system init and registers actions
  *
@@ -1115,6 +1158,10 @@ function plugin_init() {
 	run_function_once("plugin_run_once");
 
 	elgg_register_plugin_hook_handler('unit_test', 'system', 'plugins_test');
+	
+	// note - plugins are booted by the time this handler is registered
+	// deactivation due to error may have already occurred
+	elgg_register_event_handler('deactivate', 'plugin', '_plugins_deactivate_dependency_check');
 
 	elgg_register_action("plugins/settings/save", '', 'admin');
 	elgg_register_action("plugins/usersettings/save");