Issue 4579 - Ignore runtime.lastError caused by wrapper

polyfill.js

Index: polyfill.js
===================================================================
--- a/polyfill.js
+++ b/polyfill.js
@@ -38,16 +38,24 @@
     "tabs.sendMessage",
     "tabs.update",
     "webNavigation.getAllFrames",
     "webRequest.handlerBehaviorChanged",
     "windows.create",
     "windows.update"
   ];
 
+  // Since we add a callback for all messaging API calls in our wrappers,
+  // Chrome assumes we're interested in the response; when there's no response,
+  // it sets runtime.lastError
+  const portClosedBeforeResponseError =
+    // Older versions of Chrome have a typo:
+    // https://crrev.com/c33f51726eacdcc1a487b21a13611f7eab580d6d
+    /^The message port closed before a res?ponse was received\.$/;
+
   function wrapAPI(api)
   {
     let object = browser;
     let path = api.split(".");
     let name = path.pop();
 
     for (let node of path)
     {
@@ -73,17 +81,17 @@
       if (typeof args[args.length - 1] == "undefined")
         args.pop();
 
       return new Promise((resolve, reject) =>
       {
         func.call(object, ...args, result =>
         {
           let error = browser.runtime.lastError;
-          if (error)
+          if (error && !portClosedBeforeResponseError.test(error.message))
           {
             // runtime.lastError is already an Error instance on Edge, while on
             // Chrome it is a plain object with only a message property.
             if (!(error instanceof Error))
             {
               error = new Error(error.message);
 
               // Add a more helpful stack trace.