diff --git a/wp-admin/admin-ajax.php b/wp-admin/admin-ajax.php
index 44cdf64dbf49..df64921b720a 100644
--- a/wp-admin/admin-ajax.php
+++ b/wp-admin/admin-ajax.php
@@ -893,7 +893,7 @@ function _wp_ajax_add_hierarchical_term() {
 			'supplemental' => array('postid' => $pid)
 		) );
 	} else { // Update?
-		$mid = (int) array_pop(array_keys($_POST['meta']));
+		$mid = (int) array_pop( $var_by_ref = array_keys($_POST['meta']) );
 		$key = $_POST['meta'][$mid]['key'];
 		$value = $_POST['meta'][$mid]['value'];
 		if ( '' == trim($key) )
diff --git a/wp-admin/includes/nav-menu.php b/wp-admin/includes/nav-menu.php
index e467559841ce..8c8e9697f5cf 100644
--- a/wp-admin/includes/nav-menu.php
+++ b/wp-admin/includes/nav-menu.php
@@ -324,7 +324,7 @@ function _wp_ajax_menu_quick_search( $request = array() ) {
 			while ( have_posts() ) {
 				the_post();
 				if ( 'markup' == $response_format ) {
-					echo walk_nav_menu_tree( array_map('wp_setup_nav_menu_item', array( get_post( get_the_ID() ) ) ), 0, (object) $args );
+					echo walk_nav_menu_tree( array_map('wp_setup_nav_menu_item', array( get_post( $var_by_ref = get_the_ID() ) ) ), 0, (object) $args );
 				} elseif ( 'json' == $response_format ) {
 					echo json_encode(
 						array(
diff --git a/wp-admin/ms-edit.php b/wp-admin/ms-edit.php
index 5f6af9d1c2fe..c58c25c97f88 100644
--- a/wp-admin/ms-edit.php
+++ b/wp-admin/ms-edit.php
@@ -104,7 +104,7 @@
 			$move_users = array();
 			foreach ( (array)$users as $user ) {
 				$user_meta_value = unserialize( $user->meta_value );
-				if ( is_array( $user_meta_value ) && array_pop( array_keys( $user_meta_value ) ) == 'subscriber' )
+				if ( is_array( $user_meta_value ) && array_pop( $var_by_ref = array_keys( $user_meta_value ) ) == 'subscriber' )
 					$move_users[] = $user->user_id;
 			}
 			if ( false == empty( $move_users ) ) {
diff --git a/wp-app.php b/wp-app.php
index f8feb372e223..f21c3c0683ad 100644
--- a/wp-app.php
+++ b/wp-app.php
@@ -223,7 +223,7 @@ class AtomServer {
 	 */
 	function AtomServer() {
 
-		$this->script_name = array_pop(explode('/',$_SERVER['SCRIPT_NAME']));
+		$this->script_name = array_pop( $var_by_ref = explode( '/', $_SERVER['SCRIPT_NAME'] ) );
 		$this->app_base = site_url( $this->script_name . '/' );
 
 		$this->selectors = array(
diff --git a/wp-includes/query.php b/wp-includes/query.php
index cf3cc1e29b38..3a8c1e9b60ba 100644
--- a/wp-includes/query.php
+++ b/wp-includes/query.php
@@ -2738,7 +2738,8 @@ function get_queried_object() {
 			$this->queried_object = $term;
 			$this->queried_object_id = $term->term_id;
 		} elseif ( $this->is_posts_page ) {
-			$this->queried_object = & get_page(get_option('page_for_posts'));
+			$page_for_posts = get_option('page_for_posts');
+			$this->queried_object = & get_page( $page_for_posts );
 			$this->queried_object_id = (int) $this->queried_object->ID;
 		} elseif ( $this->is_single && !is_null($this->post) ) {
 			$this->queried_object = $this->post;
diff --git a/wp-includes/wp-db.php b/wp-includes/wp-db.php
index 6630efcf31e3..61f6d9aab4fa 100644
--- a/wp-includes/wp-db.php
+++ b/wp-includes/wp-db.php
@@ -1402,7 +1402,7 @@ function get_results( $query = null, $output = OBJECT ) {
 			// Return an array of row objects with keys from column 1
 			// (Duplicates are discarded)
 			foreach ( $this->last_result as $row ) {
-				$key = array_shift( get_object_vars( $row ) );
+				$key = array_shift( $var_by_ref = get_object_vars( $row ) );
 				if ( ! isset( $new_array[ $key ] ) )
 					$new_array[ $key ] = $row;
 			}