Ticket #49632: 49632.diff

wp-includes/taxonomy.php

@@ -338 +338 @@
  *
  * @global array $wp_taxonomies Registered taxonomies.
  *
- * @param string       $taxonomy    Taxonomy key, must not exceed 32 characters.
+ * @param string       $taxonomy    Taxonomy key, must not exceed 32 characters, lower case.
  * @param array|string $object_type Object type or array of object types with which the taxonomy should be associated.
  * @param array|string $args        {
  *     Optional. Array or query string of arguments for registering a taxonomy.
@@ -414 +414 @@
 function register_taxonomy( $taxonomy, $object_type, $args = array() ) {
         global $wp_taxonomies;
 
+        if ( ! empty( $taxonomy ) ) {
+                $taxonomy = strtolower( $taxonomy );
+        }
+
         if ( ! is_array( $wp_taxonomies ) ) {
                 $wp_taxonomies = array();
         }