Issue 1562 - Improve detecting of XmlHttmlRequest requests

src/plugin/PluginWbPassThrough.cpp

 #include "PluginStdAfx.h"
 
 #include "PluginWbPassThrough.h"
 #include "PluginClient.h"
 #include "PluginClientFactory.h"
 #include "PluginFilter.h"
 #include "PluginSettings.h"
 #include "PluginClass.h"
 #include "PluginSystem.h"
 #include <WinInet.h>
@@ skipping 45 matching lines @@
       return "";
     }
     std::string buf(size, '\0');
     hr = winInetHttpInfo->QueryInfo(queryOption, &buf[0], &size, &flags, 0);
     if (FAILED(hr))
     {
       return "";
     }
     return ExtractHttpHeader<std::string>(buf, "Accept:", "\r\n");
   }
+
+  bool IsXmlHttpRequest(const std::wstring& additionalHeaders)
+  {
+    auto requestedWithHeader = ExtractHttpHeader<std::wstring>(additionalHeaders, L"X-Requested-With:", L"\n");
+    return TrimString(requestedWithHeader) == L"XMLHttpRequest";
+  }
 }
 
 WBPassthruSink::WBPassthruSink()
   : m_currentPositionOfSentPage(0)
   , m_contentType(CFilter::EContentType::contentTypeAny)
   , m_blockedInTransaction(false)
 {
 }
 
 int WBPassthruSink::GetContentTypeFromMimeType(const CString& mimeType)
@@ skipping 233 matching lines @@
     {
       if (tab->IsFrameCached(ToCString(src)))
       {
         m_contentType = CFilter::contentTypeSubdocument;
       }
     }
   }
 
   if (IsFlashRequest(pszAdditionalHeaders))
   {
-    m_contentType = CFilter::EContentType::contentTypeObjectSubrequest; 
+    m_contentType = CFilter::EContentType::contentTypeObjectSubrequest;
+  }
+
+  if (pszAdditionalHeaders && IsXmlHttpRequest(*pszAdditionalHeaders))
+  {
+    m_contentType = CFilter::EContentType::contentTypeXmlHttpRequest;
   }
 
   m_blockedInTransaction = client->ShouldBlock(szURL, m_contentType, m_boundDomain, /*debug flag but must be set*/true);
   if (m_blockedInTransaction)
   {
     return E_ABORT;
   }
   return nativeHr;
 }
 
@@ skipping 53 matching lines @@
 
 STDMETHODIMP WBPassthru::LockRequest(/* [in] */ DWORD options)
 {
   return BaseClass::LockRequest(options);
 }
 
 STDMETHODIMP WBPassthru::UnlockRequest()
 {
   return BaseClass::UnlockRequest();
 }