Remove "this==NULL" and adjust corresponding callers

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 "../fpdf_page/pageint.h"
@@ skipping 60 matching lines @@
     if (m_pDocument && !bReParse) {
         delete m_pDocument;
         m_pDocument = NULL;
     }
     if (m_pTrailer) {
         m_pTrailer->Release();
         m_pTrailer = NULL;
     }
     ReleaseEncryptHandler();
     SetEncryptDictionary(NULL);
-    if (m_bOwnFileRead && m_Syntax.m_pFileAccess != NULL) {
+    if (m_bOwnFileRead && m_Syntax.m_pFileAccess) {
         m_Syntax.m_pFileAccess->Release();
         m_Syntax.m_pFileAccess = NULL;
     }
     FX_POSITION pos = m_ObjectStreamMap.GetStartPosition();
     while (pos) {
         FX_LPVOID objnum;
         CPDF_StreamAcc* pStream;
         m_ObjectStreamMap.GetNextAssoc(pos, objnum, (void*&)pStream);
         delete pStream;
     }
     m_ObjectStreamMap.RemoveAll();
     m_SortedOffset.RemoveAll();
     m_CrossRef.RemoveAll();
     m_V5Type.RemoveAll();
     m_ObjVersion.RemoveAll();
     FX_INT32 iLen = m_Trailers.GetSize();
+    CPDF_Dictionary* trailer;
     for (FX_INT32 i = 0; i < iLen; ++i) {
-        m_Trailers.GetAt(i)->Release();
+        if (trailer = m_Trailers.GetAt(i))

[Nico, 2014/06/28 01:01:07]

Nit: If you want, you can write this as

  if (CPDF_Dictionary* trailer = m_Trailers.GetAt(i))
    trailer->Release();

then you don't need the declaration on line 98.

[Bo Xu, 2014/06/28 01:26:27]

I was wondering if this will initialize |trailer| each time in the for loop. But
guess the compiler will optimize?

On 2014/06/28 01:01:07, Nico (away) wrote:

+            trailer->Release();
     }
     m_Trailers.RemoveAll();
     if (m_pLinearized) {
         m_pLinearized->Release();
         m_pLinearized = NULL;
     }
 }
 static FX_INT32 GetHeaderOffset(IFX_FileRead* pFile)
 {
     FX_DWORD tag = FXDWORD_FROM_LSBFIRST(0x46445025);
@@ skipping 993 matching lines @@
                 }
             }
         }
         segindex += count;
     }
     pStream->Release();
     return TRUE;
 }
 CPDF_Array* CPDF_Parser::GetIDArray()
 {
-    CPDF_Object* pID = m_pTrailer->GetElement(FX_BSTRC("ID"));
+    CPDF_Object* pID = m_pTrailer ? m_pTrailer->GetElement(FX_BSTRC("ID")) : NULL;
     if (pID == NULL) {
         return NULL;
     }
     if (pID->GetType() == PDFOBJ_REFERENCE) {
         pID = ParseIndirectObject(NULL, ((CPDF_Reference*)pID)->GetRefObjNum());
         m_pTrailer->SetAt(FX_BSTRC("ID"), pID);
     }
     if (pID == NULL || pID->GetType() != PDFOBJ_ARRAY) {
         return NULL;
     }
     return (CPDF_Array*)pID;
 }
 FX_DWORD CPDF_Parser::GetRootObjNum()
 {
-    CPDF_Reference* pRef = (CPDF_Reference*)m_pTrailer->GetElement(FX_BSTRC("Root"));
+    CPDF_Reference* pRef = m_pTrailer ? (CPDF_Reference*)m_pTrailer->GetElement(FX_BSTRC("Root")) : NULL;
     if (pRef == NULL || pRef->GetType() != PDFOBJ_REFERENCE) {
         return 0;
     }
     return pRef->GetRefObjNum();
 }
 FX_DWORD CPDF_Parser::GetInfoObjNum()
 {
-    CPDF_Reference* pRef = (CPDF_Reference*)m_pTrailer->GetElement(FX_BSTRC("Info"));
+    CPDF_Reference* pRef = m_pTrailer ? (CPDF_Reference*)m_pTrailer->GetElement(FX_BSTRC("Info")) : NULL;
     if (pRef == NULL || pRef->GetType() != PDFOBJ_REFERENCE) {
         return 0;
     }
     return pRef->GetRefObjNum();
 }
 FX_BOOL CPDF_Parser::IsFormStream(FX_DWORD objnum, FX_BOOL& bForm)
 {
     bForm = FALSE;
     if (objnum >= (FX_DWORD)m_CrossRef.GetSize()) {
         return TRUE;
@@ skipping 337 matching lines @@
     }
     FX_DWORD gennum = FXSYS_atoi(word);
     if (m_Syntax.GetKeyword() != FX_BSTRC("obj")) {
         m_Syntax.RestorePos(SavedPos);
         return FALSE;
     }
     m_pLinearized = m_Syntax.GetObject(NULL, objnum, gennum, 0);
     if (!m_pLinearized) {
         return FALSE;
     }
-    if (m_pLinearized->GetDict()->GetElement(FX_BSTRC("Linearized"))) {
+    if (m_pLinearized->GetDict() && m_pLinearized->GetDict()->GetElement(FX_BSTRC("Linearized"))) {
         m_Syntax.GetNextWord(bIsNumber);
         CPDF_Object *pLen = m_pLinearized->GetDict()->GetElement(FX_BSTRC("L"));
         if (!pLen) {
             m_pLinearized->Release();
             return FALSE;
         }
         if (pLen->GetInteger() != (int)pFileAccess->GetSize()) {
             return FALSE;
         }
         CPDF_Object *pNo = m_pLinearized->GetDict()->GetElement(FX_BSTRC("P"));
@@ skipping 638 matching lines @@
         if (pContext) {
             pContext->m_DictStart = SavedPos;
         }
         CPDF_Dictionary* pDict = CPDF_Dictionary::Create();
         FX_INT32 nKeys = 0;
         FX_FILESIZE dwSignValuePos = 0;
         while (1) {
             FX_BOOL bIsNumber;
             CFX_ByteString key = GetNextWord(bIsNumber);
             if (key.IsEmpty()) {
-                pDict->Release();
+                if (pDict)
+                    pDict->Release();
                 return NULL;
             }
             FX_FILESIZE SavedPos = m_Pos - key.GetLength();
             if (key == FX_BSTRC(">>")) {
                 dwDictSize = m_Pos - saveDictOffset;
                 break;
             }
             if (key == FX_BSTRC("endobj")) {
                 dwDictSize = m_Pos - 6 - saveDictOffset;
                 m_Pos = SavedPos;
@@ skipping 35 matching lines @@
             }
         }
         FX_FILESIZE SavedPos = m_Pos;
         FX_BOOL bIsNumber;
         CFX_ByteString nextword = GetNextWord(bIsNumber);
         if (nextword == FX_BSTRC("stream")) {
             CPDF_Stream* pStream = ReadStream(pDict, pContext, objnum, gennum);
             if (pStream) {
                 return pStream;
             }
-            pDict->Release();
+            if (pDict)
+                pDict->Release();
             return NULL;
         } else {
             m_Pos = SavedPos;
             return pDict;
         }
     }
     if (word == FX_BSTRC(">>")) {
         m_Pos = SavedPos;
         return NULL;
     }
@@ skipping 80 matching lines @@
         if (bTypeOnly) {
             return (CPDF_Object*)PDFOBJ_ARRAY;
         }
         CPDF_Array* pArray = CPDF_Array::Create();
         while (1) {
             CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, level + 1);
             if (pObj == NULL) {
                 if (m_WordBuffer[0] == ']') {
                     return pArray;
                 }
-                pArray->Release();
+                if (pArray)
+                    pArray->Release();
                 return NULL;
             }
             pArray->Add(pObj);
         }
     }
     if (word[0] == '/') {
         if (bTypeOnly) {
             return (CPDF_Object*)PDFOBJ_NAME;
         }
         return CPDF_Name::Create(PDF_NameDecode(CFX_ByteStringC(m_WordBuffer + 1, m_WordSize - 1)));
     }
     if (word == FX_BSTRC("<<")) {
         if (bTypeOnly) {
             return (CPDF_Object*)PDFOBJ_DICTIONARY;
         }
         if (pContext) {
             pContext->m_DictStart = SavedPos;
         }
         CPDF_Dictionary* pDict = CPDF_Dictionary::Create();
         while (1) {
             FX_BOOL bIsNumber;
             FX_FILESIZE SavedPos = m_Pos;
             CFX_ByteString key = GetNextWord(bIsNumber);
             if (key.IsEmpty()) {
-                pDict->Release();
+                if (pDict)
+                    pDict->Release();
                 return NULL;
             }
             if (key == FX_BSTRC(">>")) {
                 break;
             }
             if (key == FX_BSTRC("endobj")) {
                 m_Pos = SavedPos;
                 break;
             }
             if (key[0] != '/') {
                 continue;
             }
             key = PDF_NameDecode(key);
             CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, level + 1);
             if (pObj == NULL) {
-                pDict->Release();
+                if (pDict)
+                    pDict->Release();
                 FX_BYTE ch;
                 while (1) {
                     if (!GetNextChar(ch)) {
                         break;
                     }
                     if (ch == 0x0A || ch == 0x0D) {
                         break;
                     }
                 }
                 return NULL;
@@ skipping 11 matching lines @@
             }
         }
         FX_FILESIZE SavedPos = m_Pos;
         FX_BOOL bIsNumber;
         CFX_ByteString nextword = GetNextWord(bIsNumber);
         if (nextword == FX_BSTRC("stream")) {
             CPDF_Stream* pStream = ReadStream(pDict, pContext, objnum, gennum);
             if (pStream) {
                 return pStream;
             }
-            pDict->Release();
+            if (pDict)
+                pDict->Release();
             return NULL;
         } else {
             m_Pos = SavedPos;
             return pDict;
         }
     }
     if (word == FX_BSTRC(">>")) {
         m_Pos = SavedPos;
         return NULL;
     }
@@ skipping 434 matching lines @@
                     CPDF_Array *pArray = pObj->GetArray();
                     for (FX_DWORD k = 0; k < pArray->GetCount(); k++) {
                         new_obj_array.Add(pArray->GetElement(k));
                     }
                 }
                 break;
             case PDFOBJ_STREAM:
                 pObj = pObj->GetDict();
             case PDFOBJ_DICTIONARY: {
                     CPDF_Dictionary *pDict = pObj->GetDict();
-                    if (pDict->GetString("Type") == "Page" && !bParsePage) {
+                    if (pDict && pDict->GetString("Type") == "Page" && !bParsePage) {
                         continue;
                     }
                     FX_POSITION pos = pDict->GetStartPos();
                     while (pos) {
                         CPDF_Object *value;
                         CFX_ByteString key;
                         value = pDict->GetNextElement(pos, key);
                         if (key != "Parent") {
                             new_obj_array.Add(value);
                         }
@@ skipping 301 matching lines @@
             m_docStatus = PDF_DATAAVAIL_ACROFORM;
         } else {
             m_docStatus = PDF_DATAAVAIL_PAGETREE;
         }
     }
     return TRUE;
 }
 FX_BOOL CPDF_DataAvail::PreparePageItem()
 {
     CPDF_Dictionary *pRoot = m_pDocument->GetRoot();
-    CPDF_Reference* pRef = (CPDF_Reference*)pRoot->GetElement(FX_BSTRC("Pages"));
+    CPDF_Reference* pRef = pRoot ? (CPDF_Reference*)pRoot->GetElement(FX_BSTRC("Pages")) : NULL;
     if (pRef == NULL || pRef->GetType() != PDFOBJ_REFERENCE) {
         m_docStatus = PDF_DATAAVAIL_ERROR;
         return FALSE;
     }
     m_PagesObjNum = pRef->GetRefObjNum();
     m_pCurrentParser = (CPDF_Parser *)m_pDocument->GetParser();
     m_docStatus = PDF_DATAAVAIL_PAGETREE;
     return TRUE;
 }
 FX_BOOL CPDF_DataAvail::IsFirstCheck(int iPage)
@@ skipping 92 matching lines @@
         return TRUE;
     }
     return TRUE;
 }
 FX_BOOL CPDF_DataAvail::GetPageKids(CPDF_Parser *pParser, CPDF_Object *pPages)
 {
     if (!pParser) {
         m_docStatus = PDF_DATAAVAIL_ERROR;
         return FALSE;
     }
-    CPDF_Object *pKids = pPages->GetDict()->GetElement(FX_BSTRC("Kids"));
+    CPDF_Dictionary* pDict = pPages->GetDict();
+    CPDF_Object *pKids = pDict ? pDict->GetElement(FX_BSTRC("Kids")) : NULL;
     if (!pKids) {
         return TRUE;
     }
     switch (pKids->GetType()) {
         case PDFOBJ_REFERENCE: {
                 CPDF_Reference *pKid = (CPDF_Reference *)pKids;
                 m_PageObjList.Add(pKid->GetRefObjNum());
             }
             break;
         case PDFOBJ_ARRAY: {
@@ skipping 53 matching lines @@
             m_docStatus = PDF_DATAAVAIL_END;
         }
         return TRUE;
     }
     pHints->AddSegment(0, req_size);
     return FALSE;
 }
 FX_BOOL CPDF_DataAvail::CheckFirstPage(IFX_DownloadHints *pHints)
 {
     FX_DWORD dwFirstPageEndOffset = 0;
-    CPDF_Object *pEndOffSet = m_pLinearized->GetDict()->GetElement(FX_BSTRC("E"));
+    CPDF_Dictionary* pDict = m_pLinearized->GetDict();
+    CPDF_Object *pEndOffSet = pDict ? pDict->GetElement(FX_BSTRC("E")) : NULL;
     if (!pEndOffSet) {
         m_docStatus = PDF_DATAAVAIL_ERROR;
         return FALSE;
     }
-    CPDF_Object *pXRefOffset  = m_pLinearized->GetDict()->GetElement(FX_BSTRC("T"));
+    CPDF_Object *pXRefOffset = pDict ? pDict->GetElement(FX_BSTRC("T")) : NULL;
     if (!pXRefOffset) {
         m_docStatus = PDF_DATAAVAIL_ERROR;
         return FALSE;
     }
-    CPDF_Object *pFileLen = m_pLinearized->GetDict()->GetElement(FX_BSTRC("L"));
+    CPDF_Object *pFileLen = pDict ? pDict->GetElement(FX_BSTRC("L")) : NULL;
     if (!pFileLen) {
         m_docStatus = PDF_DATAAVAIL_ERROR;
         return FALSE;
     }
     FX_BOOL bNeedDownLoad = FALSE;
     if (pEndOffSet->GetType() == PDFOBJ_NUMBER) {
         FX_DWORD dwEnd = pEndOffSet->GetInteger();
         dwEnd += 512;
         if ((FX_FILESIZE)dwEnd > m_dwFileLen) {
             dwEnd = (FX_DWORD)m_dwFileLen;
@@ skipping 98 matching lines @@
     }
     FX_DWORD objnum = FXSYS_atoi(wordObjNum);
     if (m_pLinearized) {
         m_pLinearized->Release();
         m_pLinearized = NULL;
     }
     m_pLinearized = ParseIndirectObjectAt(m_syntaxParser.m_HeaderOffset + 9, objnum);
     if (!m_pLinearized) {
         return FALSE;
     }
-    if (m_pLinearized->GetDict()->GetElement(FX_BSTRC("Linearized"))) {
+    if (m_pLinearized->GetDict() && m_pLinearized->GetDict()->GetElement(FX_BSTRC("Linearized"))) {
         CPDF_Object *pLen = m_pLinearized->GetDict()->GetElement(FX_BSTRC("L"));
         if (!pLen) {
             return FALSE;
         }
         if ((FX_FILESIZE)pLen->GetInteger() != m_pFileRead->GetSize()) {
             return FALSE;
         }
         m_bLinearized = TRUE;
         CPDF_Object *pNo = m_pLinearized->GetDict()->GetElement(FX_BSTRC("P"));
         if (pNo && pNo->GetType() == PDFOBJ_NUMBER) {
@@ skipping 54 matching lines @@
         CFX_ByteString objnum = m_parser.m_Syntax.GetNextWord(bNumber);
         if (!bNumber) {
             return -1;
         }
         FX_DWORD objNum = FXSYS_atoi(objnum);
         CPDF_Object *pObj = m_parser.ParseIndirectObjectAt(NULL, 0, objNum, NULL);
         if (!pObj) {
             m_Pos += m_parser.m_Syntax.SavePos();
             return 0;
         }
-        CPDF_Object *pName = pObj->GetDict()->GetElement(FX_BSTRC("Type"));
+        CPDF_Dictionary* pDict = pObj->GetDict();
+        CPDF_Object *pName = pDict ? pDict->GetElement(FX_BSTRC("Type")) : NULL;
         if (pName && pName->GetType() == PDFOBJ_NAME) {
             if (pName->GetString() == FX_BSTRC("XRef")) {
                 m_Pos += m_parser.m_Syntax.SavePos();
                 xref_offset = pObj->GetDict()->GetInteger(FX_BSTRC("Prev"));
                 pObj->Release();
                 return 1;
             } else {
                 pObj->Release();
                 return -1;
             }
@@ skipping 339 matching lines @@
         pPageNode->m_type = PDF_PAGENODE_ARRAY;
         pPage->Release();
         return TRUE;
     }
     if (pPage->GetType() != PDFOBJ_DICTIONARY) {
         pPage->Release();
         m_docStatus = PDF_DATAAVAIL_ERROR;
         return FALSE;
     }
     pPageNode->m_dwPageNo = dwPageNo;
-    CFX_ByteString type = pPage->GetDict()->GetString(FX_BSTRC("Type"));
+    CPDF_Dictionary* pDict = pPage->GetDict();
+    CFX_ByteString type = pDict ? pDict->GetString(FX_BSTRC("Type")) : CFX_ByteString();
     if (type == FX_BSTRC("Pages")) {
         pPageNode->m_type = PDF_PAGENODE_PAGES;
-        CPDF_Object *pKids = pPage->GetDict()->GetElement(FX_BSTRC("Kids"));
+        CPDF_Object *pKids = pDict->GetElement(FX_BSTRC("Kids"));
         if (!pKids) {
             m_docStatus = PDF_DATAAVAIL_PAGE;
             return TRUE;
         }
         switch (pKids->GetType()) {
             case PDFOBJ_REFERENCE: {
                     CPDF_Reference *pKid = (CPDF_Reference *)pKids;
                     CPDF_PageNode *pNode = FX_NEW CPDF_PageNode();
                     pPageNode->m_childNode.Add(pNode);
                     pNode->m_dwPageNo = pKid->GetRefObjNum();
@@ skipping 444 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();
 }