Ticket #17170: attachments-hierarchically-unique.diff

wp-includes/post.php

@@ -2796 +2796 @@
         } elseif ( in_array( $post_type, $hierarchical_post_types ) ) {
                 // Page slugs must be unique within their own trees. Pages are in a separate
                 // namespace than posts so page slugs are allowed to overlap post slugs.
-                $check_sql = "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND post_type IN ( '" . implode( "', '", esc_sql( $hierarchical_post_types ) ) . "' ) AND ID != %d AND post_parent = %d LIMIT 1";
+                $check_sql = "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND post_type IN ( '" . implode( "', '", esc_sql( $hierarchical_post_types ) ) . "', 'attachment' ) AND ID != %d AND post_parent = %d LIMIT 1";
                 $post_name_check = $wpdb->get_var( $wpdb->prepare( $check_sql, $slug, $post_ID, $post_parent ) );
 
                 if ( $post_name_check || in_array( $slug, $feeds ) || preg_match( "@^($wp_rewrite->pagination_base)?\d+$@", $slug )  || apply_filters( 'wp_unique_post_slug_is_bad_hierarchical_slug', false, $slug, $post_type, $post_parent ) ) {