Fix a bug when assign the generation number of indirect objects

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 1288 matching lines @@
             return;
         }
         FX_FILESIZE SavedPos = m_Syntax.SavePos();
         m_Syntax.RestorePos(pos);
         FX_BOOL bIsNumber;
         CFX_ByteString word = m_Syntax.GetNextWord(bIsNumber);
         if (!bIsNumber) {
             m_Syntax.RestorePos(SavedPos);
             return;
         }
-        FX_DWORD real_objnum = FXSYS_atoi(word);
-        if (real_objnum && real_objnum != objnum) {
+        FX_DWORD parser_objnum = FXSYS_atoi(word);
+        if (parser_objnum && parser_objnum != objnum) {
             m_Syntax.RestorePos(SavedPos);
             return;
         }
         word = m_Syntax.GetNextWord(bIsNumber);
         if (!bIsNumber) {
             m_Syntax.RestorePos(SavedPos);
             return;
         }
         if (m_Syntax.GetKeyword() != FX_BSTRC("obj")) {
             m_Syntax.RestorePos(SavedPos);
@@ skipping 43 matching lines @@
     FX_FILESIZE SavedPos = m_Syntax.SavePos();
     m_Syntax.RestorePos(pos);
     FX_BOOL bIsNumber;
     CFX_ByteString word = m_Syntax.GetNextWord(bIsNumber);
     if (!bIsNumber) {
         m_Syntax.RestorePos(SavedPos);
         return NULL;
     }
     FX_FILESIZE objOffset = m_Syntax.SavePos();
     objOffset -= word.GetLength();
-    FX_DWORD real_objnum = FXSYS_atoi(word);
-    if (objnum && real_objnum != objnum) {
+    FX_DWORD parser_objnum = FXSYS_atoi(word);
+    if (objnum && parser_objnum != objnum) {
         m_Syntax.RestorePos(SavedPos);
         return NULL;
     }
     word = m_Syntax.GetNextWord(bIsNumber);
     if (!bIsNumber) {
         m_Syntax.RestorePos(SavedPos);
         return NULL;
     }
-    FX_DWORD gennum = FXSYS_atoi(word);
+    FX_DWORD parser_gennum = FXSYS_atoi(word);
     if (m_Syntax.GetKeyword() != FX_BSTRC("obj")) {
         m_Syntax.RestorePos(SavedPos);
         return NULL;
     }
-    CPDF_Object* pObj = m_Syntax.GetObject(pObjList, objnum, gennum, 0, pContext);
+    CPDF_Object* pObj = m_Syntax.GetObject(pObjList, objnum, parser_gennum, 0, pContext);
     FX_FILESIZE endOffset = m_Syntax.SavePos();
     CFX_ByteString bsWord = m_Syntax.GetKeyword();
     if (bsWord == FX_BSTRC("endobj")) {
         endOffset = m_Syntax.SavePos();
     }
     m_Syntax.RestorePos(SavedPos);
-    if (pObj && !objnum) {
-        pObj->m_ObjNum = real_objnum;
-        pObj->m_GenNum = gennum;
+    if (pObj) {
+        if (!objnum) {
+            pObj->m_ObjNum = parser_objnum;
+        }
+        pObj->m_GenNum = parser_gennum;
     }
     return pObj;
 }
 CPDF_Object* CPDF_Parser::ParseIndirectObjectAtByStrict(CPDF_IndirectObjects* pObjList, FX_FILESIZE pos, FX_DWORD objnum,
         struct PARSE_CONTEXT* pContext, FX_FILESIZE *pResultPos)
 {
     FX_FILESIZE SavedPos = m_Syntax.SavePos();
     m_Syntax.RestorePos(pos);
     FX_BOOL bIsNumber;
     CFX_ByteString word = m_Syntax.GetNextWord(bIsNumber);
     if (!bIsNumber) {
         m_Syntax.RestorePos(SavedPos);
         return NULL;
     }
-    FX_DWORD real_objnum = FXSYS_atoi(word);
-    if (objnum && real_objnum != objnum) {
+    FX_DWORD parser_objnum = FXSYS_atoi(word);
+    if (objnum && parser_objnum != objnum) {
         m_Syntax.RestorePos(SavedPos);
         return NULL;
     }
     word = m_Syntax.GetNextWord(bIsNumber);
     if (!bIsNumber) {
         m_Syntax.RestorePos(SavedPos);
         return NULL;
     }
     FX_DWORD gennum = FXSYS_atoi(word);
     if (m_Syntax.GetKeyword() != FX_BSTRC("obj")) {
@@ skipping 2028 matching lines @@
 }
 CPDF_Object     * CPDF_DataAvail::ParseIndirectObjectAt(FX_FILESIZE pos, FX_DWORD objnum)
 {
     FX_FILESIZE SavedPos = m_syntaxParser.SavePos();
     m_syntaxParser.RestorePos(pos);
     FX_BOOL bIsNumber;
     CFX_ByteString word = m_syntaxParser.GetNextWord(bIsNumber);
     if (!bIsNumber) {
         return NULL;
     }
-    FX_DWORD real_objnum = FXSYS_atoi(word);
-    if (objnum && real_objnum != objnum) {
+    FX_DWORD parser_objnum = FXSYS_atoi(word);
+    if (objnum && parser_objnum != objnum) {
         return NULL;
     }
     word = m_syntaxParser.GetNextWord(bIsNumber);
     if (!bIsNumber) {
         return NULL;
     }
     FX_DWORD gennum = FXSYS_atoi(word);
     if (m_syntaxParser.GetKeyword() != FX_BSTRC("obj")) {
         m_syntaxParser.RestorePos(SavedPos);
         return NULL;
@@ skipping 950 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();
 }