Bug 1620647 - Refactor nsHttpChannelAuthProvider r=ckerschb

Differential Revision: https://phabricator.services.mozilla.com/D65762

--HG--
extra : moz-landing-system : lando

netwerk/protocol/http/nsHttpChannelAuthProvider.cpp

@@ -931,17 +931,13 @@ bool nsHttpChannelAuthProvider::BlockPrompt(bool proxyAuth) {
   if (!topDoc && !xhr) {
     nsCOMPtr<nsIURI> topURI;
     Unused << chanInternal->GetTopWindowURI(getter_AddRefs(topURI));
-
-    if (!topURI) {
-      // If we do not have topURI try the loadingPrincipal.
-      nsCOMPtr<nsIPrincipal> loadingPrinc = loadInfo->LoadingPrincipal();
-      if (loadingPrinc) {
-        loadingPrinc->GetURI(getter_AddRefs(topURI));
-      }
-    }
-
-    if (!NS_SecurityCompareURIs(topURI, mURI, true)) {
-      mCrossOrigin = true;
+    nsCOMPtr<nsIPrincipal> loadingPrinc = loadInfo->LoadingPrincipal();
+    if (topURI) {
+      mCrossOrigin = !NS_SecurityCompareURIs(topURI, mURI, true);
+    } else {
+      bool sameOrigin = false;
+      loadingPrinc->IsSameOrigin(mURI, false, &sameOrigin);
+      mCrossOrigin = !sameOrigin;
     }
   }