Issue 5182 - fix IsConnectionAllowed

lib/compat.js

Index: lib/compat.js
diff --git a/lib/compat.js b/lib/compat.js
index f7ed72a23c4eae74ce70b9c89c31b681b6a04b36..b37ff5548de1867e49001e87f6eabacea892ec7b 100644
--- a/lib/compat.js
+++ b/lib/compat.js
@@ -384,7 +384,8 @@ XMLHttpRequest.prototype =
       throw new Error("Sending data to server is not supported");
 
     this.readyState = 3;
-    window._webRequest.GET(this._url, this._requestHeaders, function(result)
+
+    var onGetDone = function(result)
     {
       this.channel.status = result.status;
       this.status = result.responseStatus;
@@ -403,6 +404,22 @@ XMLHttpRequest.prototype =
       var list = this["_" + eventName + "Handlers"];
       for (var i = 0; i < list.length; i++)
         list[i].call(this, event);
+    }.bind(this);
+    // HACK (#5066): the code checking whether the connection is allowed is temporary,
+    // the actual check should be in the core when we make a decision whether
+    // to update a subscription with current connection or not, thus whether to
+    // even construct XMLHttpRequest object or not.
+    _isSubscriptionDownloadAllowed(function(isAllowed)
+    {
+      if (!isAllowed)
+      {
+        onGetDone({
+          status: 0x804b000d, //NS_ERROR_CONNECTION_REFUSED;
+          responseStatus: 0
+        });
+        return;
+      }
+      window._webRequest.GET(this._url, this._requestHeaders, onGetDone);
     }.bind(this));
   },
 
@@ -444,6 +461,16 @@ XMLHttpRequest.prototype =
   }
 };
 
+function _isSubscriptionDownloadAllowed(callback) {
+  // It's a bit hacky, JsEngine interface which is used by FilterEngine does
+  // not allow to inject an arbitrary callback, so we use triggerEvent
+  // mechanism.
+  // Yet one hack (#5039).
+  var allowed_connection_type = require("prefs").Prefs.allowed_connection_type;
+  if (allowed_connection_type == "")
+    allowed_connection_type = null;
+  _triggerEvent("_isSubscriptionDownloadAllowed", allowed_connection_type, callback);
+}
 
 // Polyfill Array.prototype.find
 // from https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/find