Fix parsing of object numbers > 16,777,216.

core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.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/include/fpdfapi/fpdf_parser.h"
 
 #include "core/include/fpdfapi/fpdf_serial.h"
 
@@ skipping 33 matching lines @@
 }
 void CFDF_Document::ParseStream(IFX_FileRead* pFile, FX_BOOL bOwnFile) {
   m_pFile = pFile;
   m_bOwnFile = bOwnFile;
   CPDF_SyntaxParser parser;
   parser.InitParser(m_pFile, 0);
   while (1) {
     bool bNumber;
     CFX_ByteString word = parser.GetNextWord(&bNumber);
     if (bNumber) {
-      FX_DWORD objnum = FXSYS_atoi(word);
+      FX_DWORD objnum = FXSYS_atoui(word);
       word = parser.GetNextWord(&bNumber);
       if (!bNumber) {
         break;
       }
       word = parser.GetNextWord(nullptr);
       if (word != "obj") {
         break;
       }
       CPDF_Object* pObj = parser.GetObject(this, objnum, 0, true);
       if (!pObj) {
@@ skipping 22 matching lines @@
     return FALSE;
   }
   buf << "%FDF-1.2\r\n";
   for (const auto& pair : m_IndirectObjs) {
     buf << pair.first << " 0 obj\r\n" << pair.second << "\r\nendobj\r\n\r\n";
   }
   buf << "trailer\r\n<</Root " << m_pRootDict->GetObjNum()
       << " 0 R>>\r\n%%EOF\r\n";
   return TRUE;
 }