Assert that only 0-numbered objects are Released()

core/fpdfapi/fpdf_parser/cpdf_dictionary.cpp

 // Copyright 2016 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/fpdfapi/fpdf_parser/cpdf_dictionary.h"
 
 #include <set>
 #include <utility>
 
 #include "core/fpdfapi/fpdf_parser/cpdf_array.h"
 #include "core/fpdfapi/fpdf_parser/cpdf_boolean.h"
 #include "core/fpdfapi/fpdf_parser/cpdf_name.h"
 #include "core/fpdfapi/fpdf_parser/cpdf_number.h"
 #include "core/fpdfapi/fpdf_parser/cpdf_reference.h"
 #include "core/fpdfapi/fpdf_parser/cpdf_stream.h"
 #include "core/fpdfapi/fpdf_parser/cpdf_string.h"
 #include "third_party/base/logging.h"
 #include "third_party/base/stl_util.h"
 
 CPDF_Dictionary::CPDF_Dictionary(const CFX_WeakPtr<CFX_ByteStringPool>& pPool)
     : m_pPool(pPool) {}
 
 CPDF_Dictionary::~CPDF_Dictionary() {
   // Mark the object as deleted so that it will not be deleted again
   // in case of cyclic references.
   m_ObjNum = kInvalidObjNum;
   for (const auto& it : m_Map) {
-    if (it.second)
+    if (it.second && it.second->GetObjNum() != kInvalidObjNum)
       it.second->Release();
   }
 }
 
 CPDF_Object::Type CPDF_Dictionary::GetType() const {
   return DICTIONARY;
 }
 
 CPDF_Dictionary* CPDF_Dictionary::GetDict() const {
   // The method should be made non-const if we want to not be const.
@@ skipping 222 matching lines @@
   pArray->AddNumber(matrix.c);
   pArray->AddNumber(matrix.d);
   pArray->AddNumber(matrix.e);
   pArray->AddNumber(matrix.f);
   SetFor(key, pArray);
 }
 
 CFX_ByteString CPDF_Dictionary::MaybeIntern(const CFX_ByteString& str) {
   return m_pPool ? m_pPool->Intern(str) : str;
 }