diff --git a/wp-includes/class-simplepie.php b/wp-includes/class-simplepie.php
index 21cc5d24eb..dab44f67a0 100644
--- a/wp-includes/class-simplepie.php
+++ b/wp-includes/class-simplepie.php
@@ -751,21 +751,24 @@ class SimplePie
 	 */
 	function __destruct()
 	{
-		if (!empty($this->data['items']))
+		if (version_compare(PHP_VERSION, '5.3', '<') || !gc_enabled())
 		{
-			foreach ($this->data['items'] as $item)
+			if (!empty($this->data['items']))
 			{
-				$item->__destruct();
+				foreach ($this->data['items'] as $item)
+				{
+					$item->__destruct();
+				}
+				unset($item, $this->data['items']);
 			}
-			unset($this->data['items']);
-		}
-		if (!empty($this->data['ordered_items']))
-		{
-			foreach ($this->data['ordered_items'] as $item)
+			if (!empty($this->data['ordered_items']))
 			{
-				$item->__destruct();
+				foreach ($this->data['ordered_items'] as $item)
+				{
+					$item->__destruct();
+				}
+				unset($item, $this->data['ordered_items']);
 			}
-			unset($this->data['ordered_items']);
 		}
 	}
 
@@ -3082,7 +3085,10 @@ class SimplePie_Item
 	 */
 	function __destruct()
 	{
-		unset($this->feed);
+		if (version_compare(PHP_VERSION, '5.3', '<') || !gc_enabled())
+		{
+			unset($this->feed);
+		}
 	}
 
 	function get_item_tags($namespace, $tag)
@@ -5682,14 +5688,6 @@ class SimplePie_Source
 		return md5(serialize($this->data));
 	}
 
-	/**
-	 * Remove items that link back to this before destroying this object
-	 */
-	function __destruct()
-	{
-		unset($this->item);
-	}
-
 	function get_source_tags($namespace, $tag)
 	{
 		if (isset($this->data['child'][$namespace][$tag]))
@@ -8954,23 +8952,12 @@ class SimplePie_Misc
 
 	function parse_url($url)
 	{
-		static $cache = array();
-		if (isset($cache[$url]))
+		preg_match('/^(([^:\/?#]+):)?(\/\/([^\/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?$/', $url, $match);
+		for ($i = count($match); $i <= 9; $i++)
 		{
-			return $cache[$url];
-		}
-		elseif (preg_match('/^(([^:\/?#]+):)?(\/\/([^\/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?$/', $url, $match))
-		{
-			for ($i = count($match); $i <= 9; $i++)
-			{
-				$match[$i] = '';
-			}
-			return $cache[$url] = array('scheme' => $match[2], 'authority' => $match[4], 'path' => $match[5], 'query' => $match[7], 'fragment' => $match[9]);
-		}
-		else
-		{
-			return $cache[$url] = array('scheme' => '', 'authority' => '', 'path' => '', 'query' => '', 'fragment' => '');
+			$match[$i] = '';
 		}
+		return array('scheme' => $match[2], 'authority' => $match[4], 'path' => $match[5], 'query' => $match[7], 'fragment' => $match[9]);
 	}
 
 	function compress_parse_url($scheme = '', $authority = '', $path = '', $query = '', $fragment = '')
@@ -10809,36 +10796,31 @@ class SimplePie_Misc
 	 */
 	function codepoint_to_utf8($codepoint)
 	{
-		static $cache = array();
 		$codepoint = (int) $codepoint;
-		if (isset($cache[$codepoint]))
+		if ($codepoint < 0)
 		{
-			return $cache[$codepoint];
-		}
-		elseif ($codepoint < 0)
-		{
-			return $cache[$codepoint] = false;
+			return false;
 		}
 		else if ($codepoint <= 0x7f)
 		{
-			return $cache[$codepoint] = chr($codepoint);
+			return chr($codepoint);
 		}
 		else if ($codepoint <= 0x7ff)
 		{
-			return $cache[$codepoint] = chr(0xc0 | ($codepoint >> 6)) . chr(0x80 | ($codepoint & 0x3f));
+			return chr(0xc0 | ($codepoint >> 6)) . chr(0x80 | ($codepoint & 0x3f));
 		}
 		else if ($codepoint <= 0xffff)
 		{
-			return $cache[$codepoint] = chr(0xe0 | ($codepoint >> 12)) . chr(0x80 | (($codepoint >> 6) & 0x3f)) . chr(0x80 | ($codepoint & 0x3f));
+			return chr(0xe0 | ($codepoint >> 12)) . chr(0x80 | (($codepoint >> 6) & 0x3f)) . chr(0x80 | ($codepoint & 0x3f));
 		}
 		else if ($codepoint <= 0x10ffff)
 		{
-			return $cache[$codepoint] = chr(0xf0 | ($codepoint >> 18)) . chr(0x80 | (($codepoint >> 12) & 0x3f)) . chr(0x80 | (($codepoint >> 6) & 0x3f)) . chr(0x80 | ($codepoint & 0x3f));
+			return chr(0xf0 | ($codepoint >> 18)) . chr(0x80 | (($codepoint >> 12) & 0x3f)) . chr(0x80 | (($codepoint >> 6) & 0x3f)) . chr(0x80 | ($codepoint & 0x3f));
 		}
 		else
 		{
 			// U+FFFD REPLACEMENT CHARACTER
-			return $cache[$codepoint] = "\xEF\xBF\xBD";
+			return "\xEF\xBF\xBD";
 		}
 	}
 
@@ -13669,4 +13651,4 @@ class SimplePie_Sanitize
 	}
 }
 
-?>
\ No newline at end of file
+?>