Bug 1556489 - P13. Use LoadInfo redirect chain to determine when a channel has redirected and we should skip uri fixup. r=mayhemer

Differential Revision: https://phabricator.services.mozilla.com/D40970

docshell/base/nsDocShell.cpp

@@ -6732,11 +6732,10 @@ nsresult nsDocShell::EndPageLoad(nsIWebProgress* aProgress,
           }
 
           if (doCreateAlternate) {
+            nsCOMPtr<nsILoadInfo> info = aChannel->LoadInfo();
             // Skip doing this if our channel was redirected, because we
             // shouldn't be guessing things about the post-redirect URI.
-            nsLoadFlags loadFlags = 0;
-            if (NS_FAILED(aChannel->GetLoadFlags(&loadFlags)) ||
-                (loadFlags & nsIChannel::LOAD_REPLACE)) {
+            if (!info->RedirectChain().IsEmpty()) {
               doCreateAlternate = false;
             }
           }