MDL-44948 add tool_qeupgradehelper to the list of deleted plugins.

lib/classes/plugin_manager.php

@@ -908,7 +908,7 @@ class core_plugin_manager {
         $plugins = array(
             'qformat' => array('blackboard'),
             'enrol' => array('authorize'),
-            'tool' => array('bloglevelupgrade'),
+            'tool' => array('bloglevelupgrade', 'qeupgradehelper'),
             'theme' => array('mymobile', 'afterburner', 'anomaly', 'arialist', 'binarius', 'boxxie', 'brick', 'formal_white',
                 'formfactor', 'fusion', 'leatherbound', 'magazine', 'nimble', 'nonzero', 'overlay', 'serenity', 'sky_high',
                 'splash', 'standard', 'standardold'),
@@ -1129,7 +1129,7 @@ class core_plugin_manager {
                 'assignmentupgrade', 'behat', 'capability', 'customlang',
                 'dbtransfer', 'generator', 'health', 'innodb', 'installaddon',
                 'langimport', 'log', 'multilangupgrade', 'phpunit', 'profiling',
-                'qeupgradehelper', 'replace', 'spamcleaner', 'task', 'timezoneimport',
+                'replace', 'spamcleaner', 'task', 'timezoneimport',
                 'unittest', 'uploadcourse', 'uploaduser', 'unsuproles', 'xmldb'
             ),
 

lib/db/upgrade.php

@@ -3033,10 +3033,16 @@ function xmldb_main_upgrade($oldversion) {
 
     if ($oldversion < 2014021900.01) {
         // Force uninstall of deleted tool.
-        if (!file_exists("$CFG->dirroot/$CFG->admin/tool/qeupgradehelper")) {
-            // Remove all other associated config.
-            unset_all_config_for_plugin('tool_qeupgradehelper');
-        }
+
+        // Normally, in this sort of situation, we would do a file_exists check,
+        // in case the plugin had been added back as an add-on. However, this
+        // plugin is completely useless after Moodle 2.6, so we check that the
+        // files have been removed in upgrade_stale_php_files_present, and we
+        // uninstall it unconditionally here.
+
+        // Remove all associated config.
+        unset_all_config_for_plugin('tool_qeupgradehelper');
+
         upgrade_main_savepoint(true, 2014021900.01);
     }