Index: src/wp-includes/category-template.php
===================================================================
--- src/wp-includes/category-template.php	(revision 52737)
+++ src/wp-includes/category-template.php	(working copy)
@@ -555,7 +555,7 @@
 	}
 
 	// Descendants of exclusions should be excluded too.
-	if ( true == $parsed_args['hierarchical'] ) {
+	if ( true === $parsed_args['hierarchical'] ) {
 		$exclude_tree = array();
 
 		if ( $parsed_args['exclude_tree'] ) {
Index: src/wp-includes/post.php
===================================================================
--- src/wp-includes/post.php	(revision 52737)
+++ src/wp-includes/post.php	(working copy)
@@ -2908,12 +2908,10 @@
  */
 function stick_post( $post_id ) {
 	$post_id  = (int) $post_id;
-	$stickies = get_option( 'sticky_posts' );
+	$stickies = get_option( 'sticky_posts', array() );
 	$updated  = false;
 
-	if ( ! is_array( $stickies ) ) {
-		$stickies = array( $post_id );
-	} else {
+	if ( $stickies ) {
 		$stickies = array_unique( array_map( 'intval', $stickies ) );
 	}