From 0414e42bbce51e721922f1dd7e658c7459f3bcda Mon Sep 17 00:00:00 2001
From: Ingo Schommer <ingo@silverstripe.com>
Date: Fri, 30 Mar 2012 18:09:03 +0200
Subject: [PATCH] MINOR Keep X-ControllerURL canonical by not re-constructing
 with question mark if there's no GET string (caused duplicate HTML5 pushState
 requests)

---
 admin/code/LeftAndMain.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/admin/code/LeftAndMain.php b/admin/code/LeftAndMain.php
index df88b41a3..851226124 100644
--- a/admin/code/LeftAndMain.php
+++ b/admin/code/LeftAndMain.php
@@ -332,7 +332,7 @@ class LeftAndMain extends Controller implements PermissionProvider {
 			$url = $request->getURL();
 			if($getVars = $request->getVars()) {
 				if(isset($getVars['url'])) unset($getVars['url']);
-				$url = Controller::join_links($url, '?' . http_build_query($getVars));
+				$url = Controller::join_links($url, $getVars ? '?' . http_build_query($getVars) : '');
 			}
 			$response->addHeader('X-ControllerURL', $url);
 		}