Support of gzip, deflate added to WinInet web request implementation

src/DefaultWebRequestWinInet.cpp

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2013 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 265 matching lines @@
     flags = WINHTTP_FLAG_SECURE;
   }
   hRequest.handle = WinHttpOpenRequest(hConnect, L"GET", urlComponents.lpszUrlPath, 0, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, flags);
 
   // Send a request.
   if (!hRequest)
   {
     result.status = WindowsErrorToGeckoError(GetLastError());
     return result;
   }
-  // TODO: Make sure for HTTP 1.1 "Accept-Encoding: gzip, deflate" doesn't HAVE to be set here
+  HTTP_VERSION_INFO ver;
+  DWORD l = sizeof(ver);
+  WinHttpQueryOption(NULL, WINHTTP_OPTION_HTTP_VERSION, (void*)&ver, &l);

[Wladimir Palant, 2013/09/04 07:21:25]

Nit: explicit conversion to void* is unnecessary IMHO.

+  if (ver.dwMinorVersion == 1)

[Oleksandr, 2013/09/03 11:49:41]

No compression for IE6 (HTTP 1.0)

[Wladimir Palant, 2013/09/04 07:21:25]

I don't like hardcoding the expectation here that there are exactly two HTTP
versions (yes, regardless of what the documentation says). How about checking
that version is at least HTTP 1.1?

if (ver.dwMajorVersion > 1 || (ver.dwMajorVersion == 1 && ver.dwMinorVersion >=
1))

Also, from what I can tell IE6 doesn't generally use HTTP 1.0 - only when it is
behind a proxy.

+  {
+    headers += L"Accept-Encoding: gzip, deflate\r\n";
+  }
   if (headers.length() > 0)
   {
     res = ::WinHttpSendRequest(hRequest, headers.c_str(), headers.length(), WINHTTP_NO_REQUEST_DATA, 0, 0, 0);
   }
   else
   {
     res = ::WinHttpSendRequest(hRequest, 0, 0, WINHTTP_NO_REQUEST_DATA, 0, 0, 0);
   }
 
   // End the request.
@@ skipping 40 matching lines @@
       ZeroMemory(outBuffer.get(), downloadSize+1);
 
       if (WinHttpReadData(hRequest, outBuffer.get(), downloadSize, &downloaded))
       {
         result.responseText.append(outBuffer.get(), downloaded);
       }
     }
   } while (downloadSize > 0);
   return result;
 }