From f089d166bc7de54674d72451a8b7783d1fda8b99 Mon Sep 17 00:00:00 2001
From: petosorus <petosorus@hotmail.fr>
Date: Tue, 1 Oct 2019 23:28:35 +0200
Subject: [PATCH] XMLHttpRequest.responseXML returns null when a network error
 occurs

---
 components/script/dom/xmlhttprequest.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/components/script/dom/xmlhttprequest.rs b/components/script/dom/xmlhttprequest.rs
index df2d0ed47c1..51a10298cda 100644
--- a/components/script/dom/xmlhttprequest.rs
+++ b/components/script/dom/xmlhttprequest.rs
@@ -1292,12 +1292,17 @@ impl XMLHttpRequest {
 
     // https://xhr.spec.whatwg.org/#document-response
     fn document_response(&self) -> Option<DomRoot<Document>> {
-        // Step 1
+        // Caching: if we have existing response xml, redirect it directly
         let response = self.response_xml.get();
         if response.is_some() {
             return self.response_xml.get();
         }
 
+        // Step 1
+        if self.response_status.get().is_err() {
+            return None;
+        }
+
         let mime_type = self.final_mime_type();
         // TODO: prescan the response to determine encoding if final charset is null
         let charset = self.final_charset().unwrap_or(UTF_8);