Fix Error when creating empty RSS feed on PHP 8

When the feed is empty, ObjectIterator::size() throws a TypeError
exception on PHP 8.0+ (and a Warning on PHP 7.2+) due to calling count()
on $this->objectlist->objects, which is null in this case.

Initializing the ObjectList::$objects property to an empty array ensures
this never happens.

File was converted to UTF-8 and trailing ?> removed.

Fixes #33634

library/README.md

@@ -6,9 +6,9 @@ The version and status of each is summarized below:
 
 ## PHP libraries
 
-| directory  | project    | version | status         |
-|------------|------------|---------|----------------|
-| rssbuilder | RSSBuilder | 2.2.1   | patched [1][2] |
+| directory  | project    | version | status              |
+|------------|------------|---------|---------------------|
+| rssbuilder | RSSBuilder | 2.2.1   | patched [1],[2],[4] |
 
 
 ## Javascript/CSS libraries
@@ -30,10 +30,10 @@ The version and status of each is summarized below:
 **Notes**
 
 1. removed `__autoload` function
-2. fixed SYSTEM NOTICE 'Only variables should be passed by reference'
+2. fixed SYSTEM NOTICE 'Only variables should be passed by reference' (#25213)
 3. fixed scrolling regression in navigation buttons, 
    patch submitted upstream https://github.com/javve/list.js/pull/750
-
+4. fixed TypeError when creating empty feed on PHP 8 (#33634)
 
 
 ## Upstream projects

library/rssbuilder/class.ObjectList.inc.php

@@ -4,7 +4,7 @@
 * Class for creating an RSS-feed
 * @author Michael Wimmer <flaimo@gmail.com>
 * @category flaimo-php
-* @copyright Copyright © 2002-2008, Michael Wimmer
+* @copyright Copyright © 2002-2008, Michael Wimmer
 * @license GNU General Public License v3
 * @link http://code.google.com/p/flaimo-php/
 * @package RSS
@@ -14,7 +14,7 @@ abstract class ObjectList extends RSSBase implements IteratorAggregate {
 
 	protected $size = 20;
 	protected $offset = 0;
-	public $objects;
+	public $objects = [];
 	protected $factory;
 
 	function __construct($offset = 0, $size = 20) {
@@ -68,4 +68,3 @@ public function getIterator() {
 		return new ObjectIterator($this);
 	} // end function
 } // end class
-?>