Index: wp-admin/includes/media.php
===================================================================
--- wp-admin/includes/media.php	(revision 28990)
+++ wp-admin/includes/media.php	(working copy)
@@ -809,6 +809,9 @@
  */
 function media_sideload_image( $file, $post_id, $desc = null ) {
 	if ( ! empty( $file ) ) {
+
+		$file_array = array();
+
 		// Set variables for storage, fix file filename for query strings.
 		preg_match( '/[^\?]+\.(jpe?g|jpe|gif|png)\b/i', $file, $matches );
 		$file_array['name'] = basename( $matches[0] );