Ticket #49628: 49628.5.diff

src/wp-includes/post.php

@@ -2086 +2086 @@
  * @since 4.4.0
  * @since 4.5.0 Added the ability to pass a post type name in addition to object.
  * @since 4.6.0 Converted the `$post_type` parameter to accept a `WP_Post_Type` object.
+ * @since 5.9.0 Added `is_post_type_viewable` hook to filter the result.
  *
  * @param string|WP_Post_Type $post_type Post type name or object.
  * @return bool Whether the post type should be considered viewable.
@@ -2102 +2103 @@
                 return false;
         }
 
-        return $post_type->publicly_queryable || ( $post_type->_builtin && $post_type->public );
+        $is_viewable = $post_type->publicly_queryable || ( $post_type->_builtin && $post_type->public );
+
+        /**
+         * Filters whether a post type is considered "viewable".
+         *
+         * @since 5.9.0
+         *
+         * @param bool         $is_viewable Whether the post type is "viewable".
+         * @param WP_Post_Type $post_type   Post type object.
+         */
+        $is_viewable = apply_filters( 'is_post_type_viewable', $is_viewable, $post_type );
+
+        // Make sure the filtered value is a boolean type before returning it.
+        if ( ! is_bool( $is_viewable ) {
+                return false;
+        }
+
+        return $is_viewable;
 }
 
 /**