Bug1373226 Fix handling of missing plugin.

Fix the handling of disabling a plugin when we find that the files
for a module are missing.

Change-Id: I706a9c4fd3c86fb1a0e330bb77c40d5e6d888a52
Signed-off-by: Nigel Cunningham <nigelc@catalyst-au.net>

htdocs/admin/extensions/plugins.php

@@ -40,9 +40,6 @@ foreach (array_keys($plugins) as $plugin) {
                     $key = blocktype_single_to_namespaced($i->name, $i->artefactplugin);
                 }
                 if (!safe_require_plugin($plugin, $key)) {
-                    if ($i->active) {
-                        $SESSION->add_error_msg(get_string('missingplugindisabled', 'admin', hsc("$plugin:$key")));
-                    }
                     continue;
                 }
                 $plugins[$plugin]['installed'][$key] = array(

htdocs/blocktype/inbox/lib.php

@@ -49,10 +49,9 @@ class PluginBlocktypeInbox extends SystemBlocktype {
         $maxitems = isset($configdata['maxitems']) ? $configdata['maxitems'] : 5;
 
         // check if multirecipientnotification plugin is active or if we proceed here
-        if (record_exists('artefact_installed', 'name', 'multirecipientnotification', 'active', '1')) {
+        if (record_exists('artefact_installed', 'name', 'multirecipientnotification', 'active', '1') && safe_require_plugin('artefact', 'multirecipientnotification')) {
             global $USER;
             $userid = $USER->get('id');
-            safe_require('artefact', 'multirecipientnotification');
             $activitylist = activitylistin(join(',', $desiredtypes), $maxitems);
             $records = array();
 

htdocs/lib/mahara.php

@@ -1468,7 +1468,14 @@ function safe_require_plugin($plugintype, $pluginname, $filename='lib.php', $fun
     }
     catch (SystemException $e) {
         if (get_field($plugintype . '_installed', 'active', 'name', $pluginname) == 1) {
+            global $SESSION;
+
             set_field($plugintype . '_installed', 'active', 0, 'name', $pluginname);
+            $SESSION->add_error_msg(get_string('missingplugindisabled', 'admin', hsc("$plugintype:$pluginname")));
+
+            // Reset the plugin cache.
+            plugins_installed('', TRUE, TRUE);
+
             // Alert site admins that the plugin is broken so was disabled
             $message = new stdClass();
             $message->users = get_column('usr', 'id', 'admin', 1);
@@ -1520,11 +1527,17 @@ function plugin_types_installed() {
  *
  * @param string $plugintype type of plugin
  * @param bool $all - return all (true) or only active (false) plugins
+ * @param bool $reset - whether to reset the cache (when disabling a plugin due to unavailability)
  * @return array of objects with fields (version (int), release (str), active (bool), name (str))
  */
-function plugins_installed($plugintype, $all=false) {
+function plugins_installed($plugintype, $all=false, $reset=false) {
     static $records = array();
 
+    if ($reset) {
+        $records = array();
+        return false;
+    }
+
     if (defined('INSTALLER') || defined('TESTSRUNNING') || !isset($records[$plugintype][true])) {
 
         $sort = $plugintype == 'blocktype' ? 'artefactplugin,name' : 'name';

htdocs/lib/web.php

@@ -2769,13 +2769,14 @@ function right_nav() {
     foreach (array('artefact', 'interaction', 'module') as $plugintype) {
         if ($plugins = plugins_installed($plugintype)) {
             foreach ($plugins as &$plugin) {
-                safe_require($plugintype, $plugin->name);
+                if (safe_require_plugin($plugintype, $plugin->name)) {
                     $plugin_nav_menu = call_static_method(generate_class_name($plugintype, $plugin->name),
                         'right_nav_menu_items');
                     $menu = array_merge($menu, $plugin_nav_menu);
                 }
             }
         }
+    }
     // local_right_nav_update allows sites to customise the menu by munging the $menu array.
     if (function_exists('local_right_nav_update')) {
         local_right_nav_update($menu);