Merge pull request #2586 from ss23/3.0-staging-fix

FIX: Move stage choosing into a pre-request filter.

_config/requestprocessors.yml

@@ -0,0 +1,8 @@
+---
+Name: requestprocessors
+---
+Injector:
+  RequestProcessor:
+    properties:
+      filters:
+        - '%$VersionedRequestFilter'

control/VersionedRequestFilter.php

@@ -0,0 +1,17 @@
+<?php
+/**
+ * Initialises the versioned stage when a request is made.
+ *
+ * @package framework
+ * @subpackage control
+ */
+class VersionedRequestFilter {
+
+	public function preRequest() {
+		Versioned::choose_site_stage();
+	}
+
+	public function postRequest() {
+	}
+
+}