make sure the value of MEDIADOWNLOAD old config is reflected into the new config,

This PR fixes elan-ev#1146.
During the migration we capture the current value of old config and map it into the new config value. Since the old one is boolean we consider only 'never' and 'allow' values for the new one!

Author: ferishili

migrations/062_add_config_custom_download.php

@@ -15,8 +15,13 @@ public function up()
             ADD COLUMN `allow_download` boolean DEFAULT NULL");
         $db->exec("ALTER TABLE `oc_video`
             ADD COLUMN `allow_download` boolean DEFAULT NULL");
+
+        // Get the current value of the config and map to new config value.
+        $current_media_download_config = (bool) Config::get()->OPENCAST_ALLOW_MEDIADOWNLOAD ?? null;
+        $new_config_value = $current_media_download_config === true ? 'allow' : 'never';
+
         $db->exec("DELETE FROM `config` WHERE `field`='OPENCAST_ALLOW_MEDIADOWNLOAD'");
-        
+
         $stmt = $db->prepare('INSERT IGNORE INTO config (field, value, section, type, `range`, mkdate, chdate, description)
                               VALUES (:name, :value, :section, :type, :range, UNIX_TIMESTAMP(), UNIX_TIMESTAMP(), :description)');
         $stmt->execute([
@@ -25,7 +30,7 @@ public function up()
             'description' => 'Erlaubnis für Mediendownloads verwalten.',
             'range'       => 'global',
             'type'        => 'string',
-            'value'       => 'never'
+            'value'       => $new_config_value
         ]);
 
         SimpleOrMap::expireTableScheme();
@@ -35,6 +40,10 @@ public function down()
     {
         $db = DBManager::get();
 
+        // Revert the config value with mapping to the old config.
+        $new_media_download_config = (string) Config::get()->OPENCAST_MEDIADOWNLOAD ?? 'never';
+        $old_config_value = $new_media_download_config !== 'allow' ? true : false;
+
         $db->exec("DELETE FROM config WHERE field = 'OPENCAST_MEDIADOWNLOAD'");
         $db->exec("ALTER TABLE `oc_playlist` DROP COLUMN `allow_download`");
         $db->exec("ALTER TABLE `oc_video` DROP COLUMN `allow_download`");
@@ -47,7 +56,7 @@ public function down()
             'description' => 'Wird Nutzern angeboten, Aufzeichnungen herunterzuladen?',
             'range'       => 'global',
             'type'        => 'boolean',
-            'value'       => true
+            'value'       => $old_config_value
         ]);
 
         SimpleOrMap::expireTableScheme();