Use std::map as CPDF_Dictionary's underlying store.

core/src/fpdfapi/fpdf_edit/fpdf_edit_create.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 "editint.h"
 
 #include "core/include/fxcrt/fx_ext.h"
 #include "core/include/fpdfapi/fpdf_serial.h"
@@ skipping 90 matching lines @@
       }
       offset += 1;
       break;
     }
     case PDFOBJ_DICTIONARY: {
       if (pFile->AppendString("<<") < 0) {
         return -1;
       }
       offset += 2;
       const CPDF_Dictionary* p = pObj->AsDictionary();
-      FX_POSITION pos = p->GetStartPos();
-      while (pos) {
-        CFX_ByteString key;
-        CPDF_Object* pValue = p->GetNextElement(pos, key);
+      for (const auto& it : *p) {
+        const CFX_ByteString& key = it.first;
+        CPDF_Object* pValue = it.second;
         if (pFile->AppendString("/") < 0) {
           return -1;
         }
         if ((len = pFile->AppendString(PDF_NameEncode(key))) < 0) {
           return -1;
         }
         offset += len + 1;
         if (pValue->GetObjNum()) {
           if (pFile->AppendString(" ") < 0) {
             return -1;
@@ skipping 47 matching lines @@
 int32_t PDF_CreatorWriteTrailer(CPDF_Document* pDocument,
                                 CFX_FileBufferArchive* pFile,
                                 CPDF_Array* pIDArray,
                                 FX_BOOL bCompress) {
   FX_FILESIZE offset = 0;
   int32_t len = 0;
   FXSYS_assert(pDocument && pFile);
   CPDF_Parser* pParser = (CPDF_Parser*)pDocument->GetParser();
   if (pParser) {
     CPDF_Dictionary* p = pParser->GetTrailer();
-    FX_POSITION pos = p->GetStartPos();
-    while (pos) {
-      CFX_ByteString key;
-      CPDF_Object* pValue = p->GetNextElement(pos, key);
+    for (const auto& it : *p) {
+      const CFX_ByteString& key = it.first;
+      CPDF_Object* pValue = it.second;
       if (key == "Encrypt" || key == "Size" || key == "Filter" ||
           key == "Index" || key == "Length" || key == "Prev" || key == "W" ||
           key == "XRefStm" || key == "Type" || key == "ID") {
         continue;
       }
       if (bCompress && key == "DecodeParms") {
         continue;
       }
       if (pFile->AppendString(("/")) < 0) {
         return -1;
@@ skipping 1005 matching lines @@
     case PDFOBJ_DICTIONARY: {
       if (!m_pCryptoHandler || pObj == m_pEncryptDict) {
         return PDF_CreatorAppendObject(pObj, &m_File, m_Offset);
       }
       if (m_File.AppendString("<<") < 0) {
         return -1;
       }
       m_Offset += 2;
       const CPDF_Dictionary* p = pObj->AsDictionary();
       bool bSignDict = IsSignatureDict(p);
-      FX_POSITION pos = p->GetStartPos();
-      while (pos) {
+      for (const auto& it : *p) {
         FX_BOOL bSignValue = FALSE;
-        CFX_ByteString key;
-        CPDF_Object* pValue = p->GetNextElement(pos, key);
+        const CFX_ByteString& key = it.first;
+        CPDF_Object* pValue = it.second;
         if (m_File.AppendString("/") < 0) {
           return -1;
         }
         if ((len = m_File.AppendString(PDF_NameEncode(key))) < 0) {
           return -1;
         }
         m_Offset += len + 1;
         if (bSignDict && key == "Contents") {
           bSignValue = TRUE;
         }
@@ skipping 544 matching lines @@
     } else {
       if (m_File.AppendDWord(m_pDocument->m_LastObjNum + 1) < 0) {
         return -1;
       }
       if (m_File.AppendString(" 0 obj <<") < 0) {
         return -1;
       }
     }
     if (m_pParser) {
       CPDF_Dictionary* p = m_pParser->m_pTrailer;
-      FX_POSITION pos = p->GetStartPos();
-      while (pos) {
-        CFX_ByteString key;
-        CPDF_Object* pValue = p->GetNextElement(pos, key);
+      for (const auto& it : *p) {
+        const CFX_ByteString& key = it.first;
+        CPDF_Object* pValue = it.second;
         if (key == "Encrypt" || key == "Size" || key == "Filter" ||

[Tom Sepez, 2016/01/08 00:33:52]

NB: similar to line 184, but missing "Type".  Wonder if thats a bug.  Either
way, consolidate the others in a helper function someday.

[Oliver Chang, 2016/01/08 23:14:58]

ack. added a TODO.

             key == "Index" || key == "Length" || key == "Prev" || key == "W" ||
             key == "XRefStm" || key == "ID") {
           continue;
         }
         if (m_File.AppendString(("/")) < 0) {
           return -1;
         }
         if (m_File.AppendString(PDF_NameEncode(key)) < 0) {
           return -1;
         }
         if (pValue->GetObjNum()) {
           if (m_File.AppendString(" ") < 0) {
             return -1;
           }
           if (m_File.AppendDWord(pValue->GetObjNum()) < 0) {

[Tom Sepez, 2016/01/08 00:33:52]

NB: also a helper method to append  "objnum 0 R" - look a all the " 0 R"
literals.

[Oliver Chang, 2016/01/08 23:14:58]

ack. added a TODO.

             return -1;
           }
           if (m_File.AppendString(" 0 R ") < 0) {
             return -1;
           }
         } else {
           FX_FILESIZE offset = 0;
           if (PDF_CreatorAppendObject(pValue, &m_File, offset) < 0) {
             return -1;
           }
@@ skipping 283 matching lines @@
   m_bNewCrypto = FALSE;
   if (!m_bStandardSecurity) {
     return;
   }
   if (m_pEncryptDict) {
     m_pEncryptDict->Release();
     m_pEncryptDict = NULL;
   }
   m_bStandardSecurity = FALSE;
 }