From 5e9f9f9801a99558b793f640802591c0a792a300 Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@google.com>
Date: Mon, 11 Jan 2021 13:25:51 -0800
Subject: [PATCH] Pass along document.referrer as amp_referrer query parameter
 during mobile redirection

---
 assets/src/mobile-redirection.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/assets/src/mobile-redirection.js b/assets/src/mobile-redirection.js
index ba833e45e10..6a04c2fab21 100644
--- a/assets/src/mobile-redirection.js
+++ b/assets/src/mobile-redirection.js
@@ -70,6 +70,11 @@
 		// from ensuing. See <https://github.com/ampproject/amp-wp/issues/5767>.
 		window.stop(); // Stop loading the page! This should cancel all loading resources.
 
+		// Pass along referrer so that amp-analytics can report the correct referrer.
+		if ( document.referrer ) {
+			amphtmlUrlObject.searchParams.set( 'amp_referrer', document.referrer );
+		}
+
 		// Replace the current page with the AMP version.
 		location.replace( amphtmlUrlObject.href );
 	}