generate password if wanted on usermodify FS#1873

lib/plugins/usermanager/admin.php

@@ -398,7 +398,7 @@ class admin_plugin_usermanager extends DokuWiki_Admin_Plugin {
           }
         } else {
           if (!empty($mail)){
-          	return false;
+            return false;
           }
         }
 
@@ -506,6 +506,11 @@ class admin_plugin_usermanager extends DokuWiki_Admin_Plugin {
           }
         }
 
+        // generate password if left empty and notification is on
+        if(!empty($_REQUEST['usernotify']) && empty($newpass)){
+            $newpass = auth_pwgen();
+        }
+
         if (!empty($newpass) && $this->_auth->canDo('modPass'))
           $changes['pass'] = $newpass;
         if (!empty($newname) && $this->_auth->canDo('modName') && $newname != $oldinfo['name'])