Add Resque_Event::listen() call to register the testsession state switcher

with the silverstripe-resque module.

_config.php

@@ -1,4 +1,27 @@
 <?php
 
 // Determine whether there is a testsession currently running, and if so - setup the persistent details for it.
-Injector::inst()->get('TestSessionEnvironment')->loadFromFile();
+Injector::inst()->get('TestSessionEnvironment')->loadFromFile();
+
+/**
+ * This closure will run every time a Resque_Event is forked (just before it is forked, so it applies to the parent
+ * and child process).
+ */
+if(class_exists('Resque_Event') && class_exists('SSResqueRun')) {
+	Resque_Event::listen('beforeFork', function($data) {
+		global $databaseConfig;
+
+		// Reconnect to the database - this may connect to the old DB first, but is required because these processes
+		// are long-lived, and MySQL connections often get closed in between worker runs. We need to connect before
+		// calling {@link TestSessionEnvironment::loadFromFile()}.
+		DB::connect($databaseConfig);
+
+		$testEnv = Injector::inst()->get('TestSessionEnvironment');
+
+		if($testEnv->isRunningTests()) {
+			$testEnv->loadFromFile();
+		} else {
+			$testEnv->endTestSession();
+		}
+	});
+}