Ticket #41564: 41564.diff

src/wp-includes/template.php

@@ -114 +114 @@
         if ( count( $post_types ) == 1 ) {
                 $post_type = reset( $post_types );
                 $templates[] = "archive-{$post_type}.php";
+
+                // Prepend the hyphenated post type name as a higher priority template.
+                if ( strpos( $post_type, '_' ) ) {
+                        array_unshift( $templates, 'archive-' . str_replace( '_', '-', $post_type ) . '.php' );
+                }
         }
         $templates[] = 'archive.php';