Update safe numerics package to get bitwise ops

core/fxcrt/fx_extension.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fxcrt/extension.h"
 
 #include <algorithm>
 #include <memory>
@@ skipping 186 matching lines @@
   return m_nCurPos >= (size_t)GetSize();
 }
 
 FX_FILESIZE CFX_MemoryStream::GetPosition() {
   return (FX_FILESIZE)m_nCurPos;
 }
 
 bool CFX_MemoryStream::ReadBlock(void* buffer,
                                  FX_FILESIZE offset,
                                  size_t size) {
-  if (!buffer || !size)
+  if (!buffer || !size || offset < 0)
     return false;
 
   FX_SAFE_SIZE_T newPos = size;
   newPos += offset;
   if (!newPos.IsValid() || newPos.ValueOrDefault(0) == 0 ||
       newPos.ValueOrDie() > m_nCurSize) {
     return false;
   }
 
   m_nCurPos = newPos.ValueOrDie();
@@ skipping 449 matching lines @@
     b = ((const uint8_t*)pGUID)[i];
     *pBuf++ = gs_FX_pHexChars[b >> 4];
     *pBuf++ = gs_FX_pHexChars[b & 0x0F];
     if (bSeparator && (i == 3 || i == 5 || i == 7 || i == 9)) {
       *pBuf++ = L'-';
     }
   }
   bsStr.ReleaseBuffer(bSeparator ? 36 : 32);
 }
 #endif  // PDF_ENABLE_XFA