Issue 4931 - add possibility to not send data depending on connection properties

src/WebRequestJsObject.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 38 matching lines @@
           if (header.length() && headerValue.length())
             headers.push_back(std::pair<std::string, std::string>(header, headerValue));
         }
       }
 
       callback = arguments[2];
       if (!callback->IsFunction())
         throw std::runtime_error("Third argument to GET must be a function");
     }
 
+    AdblockPlus::ServerResponse NotAllowedResponse()
+    {
+      AdblockPlus::ServerResponse result;
+      result.status = AdblockPlus::WebRequest::NS_ERROR_CONNECTION_REFUSED;
+      result.responseStatus = 0;
+      return result;
+    }
+
     void Run()
     {
-      AdblockPlus::ServerResponse result = jsEngine->GetWebRequest()->GET(url, headers);
+      AdblockPlus::ServerResponse result = jsEngine->IsConnectionAllowed() ?
+        jsEngine->GetWebRequest()->GET(url, headers) : NotAllowedResponse();

[Eric, 2017/02/28 17:35:37]

This is an absolutely awful place to intervene. It means, among other things,
that it will be impossible to distinguish between an actual failure and a
synthetic one unless you've got access to global configuration preference, and
that's just a bad design choice.

[sergei, 2017/02/28 22:27:23]

It is also one of known concerns, yes, UX will suffer from it until it's in
adblockpluscore.

 
       AdblockPlus::JsContext context(jsEngine);
 
       AdblockPlus::JsValuePtr resultObject = jsEngine->NewObject();
       resultObject->SetProperty("status", result.status);
       resultObject->SetProperty("responseStatus", result.responseStatus);
       resultObject->SetProperty("responseText", result.responseText);
 
       AdblockPlus::JsValuePtr headersObject = jsEngine->NewObject();
       for (AdblockPlus::HeaderList::iterator it = result.responseHeaders.begin();
@@ skipping 36 matching lines @@
     return v8::Undefined();
   }
 }
 
 AdblockPlus::JsValuePtr AdblockPlus::WebRequestJsObject::Setup(
     AdblockPlus::JsEnginePtr jsEngine, AdblockPlus::JsValuePtr obj)
 {
   obj->SetProperty("GET", jsEngine->NewCallback(::GETCallback));
   return obj;
 }