Correct the way to count pages and to avoid infinite loop

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 "core/include/fpdfapi/fpdf_parser.h"
 
 #include <algorithm>
 #include <memory>
@@ skipping 18 matching lines @@
 // A limit on the maximum object number in the xref table. Theoretical limits
 // are higher, but this may be large enough in practice.
 const FX_DWORD kMaxObjectNumber = 1048576;
 
 struct SearchTagRecord {
   const char* m_pTag;
   FX_DWORD m_Len;
   FX_DWORD m_Offset;
 };
 
-template <typename T>
-class ScopedSetInsertion {
- public:
-  ScopedSetInsertion(std::set<T>* org_set, T elem)
-      : m_Set(org_set), m_Entry(elem) {
-    m_Set->insert(m_Entry);
-  }
-  ~ScopedSetInsertion() { m_Set->erase(m_Entry); }
-
- private:
-  std::set<T>* const m_Set;
-  const T m_Entry;
-};
-
 int CompareFileSize(const void* p1, const void* p2) {
   return *(FX_FILESIZE*)p1 - *(FX_FILESIZE*)p2;
 }
 
 int32_t GetHeaderOffset(IFX_FileRead* pFile) {
   const FX_DWORD tag = FXDWORD_FROM_LSBFIRST(0x46445025);
   const size_t kBufSize = 4;
   uint8_t buf[kBufSize];
   int32_t offset = 0;
   while (offset <= 1024) {
@@ skipping 4945 matching lines @@
   if (!m_pLinearizedDict)
     return -1;
   CPDF_Array* pRange = m_pLinearizedDict->GetArray("H");
   if (!pRange)
     return -1;
   CPDF_Object* pStreamLen = pRange->GetElementValue(1);
   if (!pStreamLen)
     return -1;
   return pStreamLen->GetInteger();
 }