--- /dev/null
+<?php
+
+// Get a $_SERVER key, or equivalent environment variable
+// if it is not set in $_SERVER.
+function runserver_env($key) {
+ if (isset($_SERVER[$key])) {
+ return $_SERVER[$key];
+ }
+ else {
+ return getenv($key);
+ }
+}
+
+$url = parse_url($_SERVER["REQUEST_URI"]);
+if (file_exists('.' . $url['path'])) {
+ // Serve the requested resource as-is.
+ return FALSE;
+}
+
+// We set the base_url so that Drupal generates correct URLs for runserver
+// (e.g. http://127.0.0.1:8888/...), but can still select and serve a specific
+// site in a multisite configuration (e.g. http://mysite.com/...).
+$base_url = runserver_env('RUNSERVER_BASE_URL');
+
+// The built in webserver incorrectly sets $_SERVER['SCRIPT_NAME'] when URLs
+// contain multiple dots (such as config entity IDs) in the path. Since this is
+// a virtual resource, served by index.php set the script name explicitly.
+// See https://github.com/drush-ops/drush/issues/2033 for more information.
+$_SERVER['SCRIPT_NAME'] = '/index.php';
+
+// Include the main index.php and let Drupal take over.
+// n.b. Drush sets the cwd to the Drupal root during bootstrap.
+include 'index.php';