Ticket #10977: wp_list_pages-no_leading_exclude_comma.patch

post-template.php

@@ -757 +757 @@
         // sanitize, mostly to keep spaces out
         $r['exclude'] = preg_replace('/[^0-9,]/', '', $r['exclude']);
 
-        // Allow plugins to filter an array of excluded pages
-        $r['exclude'] = implode(',', apply_filters('wp_list_pages_excludes', explode(',', $r['exclude'])));
+        // Allow plugins to filter an array of excluded pages (but don't put a nullstring into the array)
+        $exclude_array = ( $r['exclude'] ) ? explode(',', $r['exclude']) : array();
+        $r['exclude'] = implode( ',', apply_filters('wp_list_pages_excludes', $exclude_array) );
 
         // Query pages.
         $r['hierarchical'] = 0;