Bug 40491: Don't auto-pick a v2 address when it's in Onion-Location header

We could do a more strict validation on the v3 host, if needed.

Also linted/formatted Document.cpp before applying the new patch.

Closes #40491 (closed).

dom/base/Document.cpp

@@ -6831,18 +6831,37 @@ void Document::GetHeaderData(nsAtom* aHeaderField, nsAString& aData) const {
 static bool IsValidOnionLocation(nsIURI* aDocumentURI,
                                  nsIURI* aOnionLocationURI) {
+  if (!aDocumentURI || !aOnionLocationURI) {
+    return false;
+  }
+
   bool isHttpish;
   nsAutoCString host;
-  return aDocumentURI && aOnionLocationURI &&
-         NS_SUCCEEDED(aDocumentURI->SchemeIs("https", &isHttpish)) &&
-         isHttpish && NS_SUCCEEDED(aDocumentURI->GetAsciiHost(host)) &&
-         !StringEndsWith(host, ".onion"_ns) &&
-         ((NS_SUCCEEDED(aOnionLocationURI->SchemeIs("http", &isHttpish)) &&
-           isHttpish) ||
-          (NS_SUCCEEDED(aOnionLocationURI->SchemeIs("https", &isHttpish)) &&
-           isHttpish)) &&
-         NS_SUCCEEDED(aOnionLocationURI->GetAsciiHost(host)) &&
-         StringEndsWith(host, ".onion"_ns);
+  if (!(NS_SUCCEEDED(aDocumentURI->SchemeIs("https", &isHttpish)) &&
+        isHttpish) ||
+      !(NS_SUCCEEDED(aDocumentURI->GetAsciiHost(host)) &&
+        !StringEndsWith(host, ".onion"_ns))) {
+    return false;
+  }
+
+  if (!((NS_SUCCEEDED(aOnionLocationURI->SchemeIs("http", &isHttpish)) &&
+         isHttpish) ||
+        (NS_SUCCEEDED(aOnionLocationURI->SchemeIs("https", &isHttpish)) &&
+         isHttpish))) {
+    return false;
+  }
+
+  nsCOMPtr<nsIEffectiveTLDService> eTLDService =
+      do_GetService(NS_EFFECTIVETLDSERVICE_CONTRACTID);
+  if (!eTLDService) {
+    return NS_SUCCEEDED(aOnionLocationURI->GetAsciiHost(host)) &&
+           StringEndsWith(host, ".onion"_ns);
+  }
+  if (!NS_SUCCEEDED(eTLDService->GetBaseDomain(aOnionLocationURI, 0, host))) {
+    return false;
+  }
+  return (host.Length() == 62 && StringEndsWith(host, ".onion"_ns)) ||
+         StringEndsWith(host, ".tor.onion"_ns);
 }
 void Document::SetHeaderData(nsAtom* aHeaderField, const nsAString& aData) {