NoUriException added and implemented in FeedSub class

This is a specific exception for objects which require URI but lack it,
first implemented in FeedSub to allow for identification of bad entries.

lib/nouriexception.php

@@ -0,0 +1,42 @@
+<?php
+/**
+ * GNU social - a federating social network
+ *
+ * class for when an object that's supposed to have a URI is missing it
+ *
+ * PHP version 5
+ *
+ * LICENCE: This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Exception
+ * @package   GNUsocial
+ * @author    Mikael Nordfeldth <mmn@hethane.se>
+ * @copyright 2014 Free Software Foundation, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPLv3
+ * @link      https://www.gnu.org/software/social/
+ */
+
+if (!defined('GNUSOCIAL')) { exit(1); }
+
+class NoUriException extends ServerException
+{
+    var $object = null;
+
+    public function __construct(Managed_DataObject $object)
+    {
+        $this->object = $object;
+        $msg = get_class($object) . ' does not have a URI.';
+        parent::__construct($msg);
+    }
+}

plugins/OStatus/classes/FeedSub.php

@@ -103,7 +103,7 @@ class FeedSub extends Managed_DataObject
     public function getUri()
     {
         if (empty($this->uri)) {
-            throw new ServerException('No URI for FeedSub entry');
+            throw new NoUriException($this);
         }
         return $this->uri;
     }