Index: includes/abstract-testcase.php
===================================================================
--- includes/abstract-testcase.php	(revision 45484)
+++ includes/abstract-testcase.php	(working copy)
@@ -707,7 +707,7 @@
 		// from all over the place (globals, GET, etc), which makes it tricky
 		// to run them more than once without very carefully clearing everything
 		$_GET = $_POST = array();
-		foreach ( array( 'query_string', 'id', 'postdata', 'authordata', 'day', 'currentmonth', 'page', 'pages', 'multipage', 'more', 'numpages', 'pagenow' ) as $v ) {
+		foreach ( array( 'query_string', 'id', 'postdata', 'authordata', 'day', 'currentmonth', 'page', 'pages', 'multipage', 'more', 'numpages', 'pagenow', 'current_screen' ) as $v ) {
 			if ( isset( $GLOBALS[ $v ] ) ) {
 				unset( $GLOBALS[ $v ] );
 			}