Fix Regression: Incomplete file loading is seen for multi page pdf files.

core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.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 "../../../include/fpdfapi/fpdf_parser.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fpdfapi/fpdf_page.h"
 #include "../../../../third_party/numerics/safe_math.h"
@@ skipping 1009 matching lines @@
     }
     if (bMainXRef) {
         m_pTrailer = (CPDF_Dictionary*)pStream->GetDict()->Clone();
         m_CrossRef.SetSize(size);
         if (m_V5Type.SetSize(size)) {
             FXSYS_memset32(m_V5Type.GetData(), 0, size);
         }
     } else {
         m_Trailers.Add((CPDF_Dictionary*)pStream->GetDict()->Clone());
     }
-    FX_DWORD nSegs = 0;
-    std::vector <std::pair <FX_INT32, FX_INT32>> arrIndex;
+    std::vector<std::pair<FX_INT32, FX_INT32> > arrIndex;
     CPDF_Array* pArray = pStream->GetDict()->GetArray(FX_BSTRC("Index"));
     if (pArray) {
         FX_DWORD nPairSize = pArray->GetCount() / 2;
-        CPDF_Object* pStartNumObj = NULL;
-        CPDF_Object* pCountObj = NULL;
         for (FX_DWORD i = 0; i < nPairSize; i++) {
-            pStartNumObj = pArray->GetElement(i * 2);
-            pCountObj = pArray->GetElement(i * 2 + 1);
+            CPDF_Object* pStartNumObj = pArray->GetElement(i * 2);
+            CPDF_Object* pCountObj = pArray->GetElement(i * 2 + 1);
             if (pStartNumObj && pStartNumObj->GetType() == PDFOBJ_NUMBER
                 && pCountObj && pCountObj->GetType() == PDFOBJ_NUMBER) {
                 arrIndex.push_back(std::make_pair(pStartNumObj->GetInteger(), pCountObj->GetInteger()));
             }
         }
-        nSegs = arrIndex.size();
-        if (nSegs == 0) {
-            arrIndex.push_back(std::make_pair(0, size));
-            nSegs = 1;
-        }
+    }
+    if (arrIndex.size() == 0) {
+        arrIndex.push_back(std::make_pair(0, size));
     }
     pArray = pStream->GetDict()->GetArray(FX_BSTRC("W"));
     if (pArray == NULL) {
         pStream->Release();
         return FALSE;
     }
     CFX_DWordArray WidthArray;
     FX_SAFE_DWORD dwAccWidth = 0;
     for (FX_DWORD i = 0; i < pArray->GetCount(); i ++) {
         WidthArray.Add(pArray->GetInteger(i));
         dwAccWidth += WidthArray[i];
     }
     if (!dwAccWidth.IsValid() || WidthArray.GetSize() < 3) {
         pStream->Release();
         return FALSE;
     }
     FX_DWORD totalWidth = dwAccWidth.ValueOrDie();
     CPDF_StreamAcc acc;
     acc.LoadAllData(pStream);
     FX_LPCBYTE pData = acc.GetData();
     FX_DWORD dwTotalSize = acc.GetSize();
     FX_DWORD segindex = 0;
-    for (FX_DWORD i = 0; i < nSegs; i ++) {
+    for (FX_DWORD i = 0; i < arrIndex.size(); i ++) {
         FX_INT32 startnum = arrIndex[i].first;
         if (startnum < 0) {
             continue;
         }
         m_dwXrefStartObjNum = base::checked_cast<FX_DWORD, FX_INT32> (startnum);
         FX_DWORD count = base::checked_cast<FX_DWORD, FX_INT32> (arrIndex[i].second);
         FX_SAFE_DWORD dwCaculatedSize = segindex;
         dwCaculatedSize += count;
         dwCaculatedSize *= totalWidth;
         if (!dwCaculatedSize.IsValid() || dwCaculatedSize.ValueOrDie() > dwTotalSize) { 
@@ skipping 3353 matching lines @@
 {
     FX_INT32 iSize = m_childNode.GetSize();
     for (FX_INT32 i = 0; i < iSize; ++i) {
         CPDF_PageNode *pNode = (CPDF_PageNode*)m_childNode[i];
         if (pNode) {
             delete pNode;
         }
     }
     m_childNode.RemoveAll();
 }