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

fpdfsdk/src/fpdfppo.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 "public/fpdf_ppo.h"
 
 #include "fpdfsdk/include/fsdk_define.h"
 #include "third_party/base/nonstd_unique_ptr.h"
@@ skipping 82 matching lines @@
 
   nonstd::unique_ptr<ObjectNumberMap> pObjNumberMap(new ObjectNumberMap);
 
   for (int i = 0; i < nPageNum->GetSize(); ++i) {
     CPDF_Dictionary* pCurPageDict = pDestPDFDoc->CreateNewPage(curpage);
     CPDF_Dictionary* pSrcPageDict = pSrcPDFDoc->GetPage(nPageNum->GetAt(i) - 1);
     if (!pSrcPageDict || !pCurPageDict)
       return FALSE;
 
     // Clone the page dictionary
-    FX_POSITION SrcPos = pSrcPageDict->GetStartPos();
-    while (SrcPos) {
-      CFX_ByteString cbSrcKeyStr;
-      CPDF_Object* pObj = pSrcPageDict->GetNextElement(SrcPos, cbSrcKeyStr);
+    for (const auto& it : *pSrcPageDict) {
+      const CFX_ByteString& cbSrcKeyStr = it.first;
+      CPDF_Object* pObj = it.second;
       if (cbSrcKeyStr.Compare(("Type")) && cbSrcKeyStr.Compare(("Parent"))) {
         if (pCurPageDict->KeyExist(cbSrcKeyStr))
           pCurPageDict->RemoveAt(cbSrcKeyStr);
         pCurPageDict->SetAt(cbSrcKeyStr, pObj->Clone());
       }
     }
 
     // inheritable item
     CPDF_Object* pInheritable = nullptr;
     // 1 MediaBox  //required
@@ skipping 89 matching lines @@
     case PDFOBJ_REFERENCE: {
       CPDF_Reference* pReference = pObj->AsReference();
       FX_DWORD newobjnum = GetNewObjId(pDoc, pObjNumberMap, pReference);
       if (newobjnum == 0)
         return FALSE;
       pReference->SetRef(pDoc, newobjnum);
       break;
     }
     case PDFOBJ_DICTIONARY: {
       CPDF_Dictionary* pDict = pObj->AsDictionary();
-
-      FX_POSITION pos = pDict->GetStartPos();
-      while (pos) {
-        CFX_ByteString key("");
-        CPDF_Object* pNextObj = pDict->GetNextElement(pos, key);
+      for (const auto& it : *pDict) {
+        const CFX_ByteString& key = it.first;
+        CPDF_Object* pNextObj = it.second;
         if (!FXSYS_strcmp(key, "Parent") || !FXSYS_strcmp(key, "Prev") ||
             !FXSYS_strcmp(key, "First")) {
           continue;
         }
         if (pNextObj) {
           if (!UpdateReference(pNextObj, pDoc, pObjNumberMap))
             pDict->RemoveAt(key);
         } else {
           return FALSE;
         }
@@ skipping 167 matching lines @@
   if (!pSrcDict)
     return FALSE;
 
   CPDF_Dictionary* pDstDict = pDstDoc->GetRoot();
   if (!pDstDict)
     return FALSE;
 
   pDstDict->SetAt("ViewerPreferences", pSrcDict->Clone(TRUE));
   return TRUE;
 }