Bug 1550171 - Don't apply Password Manager to about: pages. r=MattN

Differential Revision: https://phabricator.services.mozilla.com/D37998

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

browser/base/content/content.js

@@ -40,9 +40,10 @@ addMessageListener("PasswordManager:fillGeneratedPassword", function(message) {
 });
 
 function shouldIgnoreLoginManagerEvent(event) {
+  let nodePrincipal = event.target.nodePrincipal;
   // If we have a null principal then prevent any more password manager code from running and
-  // incorrectly using the document `location`.
-  return event.target.nodePrincipal.isNullPrincipal;
+  // incorrectly using the document `location`. Also skip password manager for about: pages.
+  return nodePrincipal.isNullPrincipal || nodePrincipal.URI.schemeIs("about");
 }
 
 addEventListener("DOMFormBeforeSubmit", function(event) {

mobile/android/components/BrowserCLH.js

@@ -212,9 +212,12 @@ BrowserCLH.prototype = {
     }
 
     function shouldIgnoreLoginManagerEvent(event) {
+      let nodePrincipal = event.target.nodePrincipal;
       // If we have a null principal then prevent any more password manager code from running and
-      // incorrectly using the document `location`.
-      return event.target.nodePrincipal.isNullPrincipal;
+      // incorrectly using the document `location`. Also skip password manager for about: pages.
+      return (
+        nodePrincipal.isNullPrincipal || nodePrincipal.URI.schemeIs("about")
+      );
     }
 
     let options = {