MDL-22787 Fixed enrol_mnet upgrade procedure

For any courses where at least one remote student was enrolled via 1.x
enrol_mnet plugin, the record in the table enrol was created
automatically by core during the upgrade to the new enrolment framework.
We just need to set the custom field to explicitly indicate that the
course is open for all remote hosts.

enrol/mnet/db/upgrade.php

@@ -0,0 +1,38 @@
+<?php
+
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Keeps track of upgrades to the enrol_mnet plugin
+ *
+ * @package    enrol
+ * @subpackage mnet
+ * @copyright  2010 David Mudrak <david@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+function xmldb_enrol_mnet_upgrade($oldversion) {
+    global $CFG, $DB, $OUTPUT;
+
+    // when core upgraded all legacy enrol mnet plugins, it created instances of the plugin
+    // here we set customint1 to 0 which means 'open for all hosts' (legacy behaviour)
+    if ($oldversion < 2010071701) {
+        $DB->set_field('enrol', 'customint1', 0, array('enrol' => 'mnet', 'customint1' => null));
+        upgrade_plugin_savepoint(true, 2010071701, 'enrol', 'mnet');
+    }
+
+    return true;
+}

enrol/mnet/version.php

@@ -24,4 +24,4 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-$plugin->version = 2010071700;
+$plugin->version = 2010071701;