Revert "Revert "Add type cast definitions for CPDF_Dictionary.""

core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.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/fxcrt/fx_string.h"
 
 // static
@@ skipping 10 matching lines @@
     case PDFOBJ_STRING:
       delete (CPDF_String*)this;
       break;
     case PDFOBJ_NAME:
       delete (CPDF_Name*)this;
       break;
     case PDFOBJ_ARRAY:
       delete (CPDF_Array*)this;
       break;
     case PDFOBJ_DICTIONARY:
-      delete (CPDF_Dictionary*)this;
+      delete this->AsDictionary();
       break;
     case PDFOBJ_STREAM:
       delete (CPDF_Stream*)this;
       break;
     default:
       delete this;
   }
 }
 CFX_ByteString CPDF_Object::GetString() const {
   switch (m_Type) {
@@ skipping 89 matching lines @@
       }
       return pObj->GetInteger();
     }
   }
   return 0;
 }
 
 CPDF_Dictionary* CPDF_Object::GetDict() const {
   switch (m_Type) {
     case PDFOBJ_DICTIONARY:
-      return (CPDF_Dictionary*)this;
+      // The method should be made non-const if we want to not be const.
+      // See bug #234.
+      return const_cast<CPDF_Dictionary*>(this->AsDictionary());
     case PDFOBJ_STREAM:
       return ((CPDF_Stream*)this)->GetDict();
     case PDFOBJ_REFERENCE: {
       CPDF_Reference* pRef = (CPDF_Reference*)this;
       CPDF_IndirectObjects* pIndirect = pRef->GetObjList();
       if (!pIndirect)
         return nullptr;
       CPDF_Object* pObj = pIndirect->GetIndirectObject(pRef->GetRefObjNum());
       if (!pObj || (pObj == this))
         return nullptr;
@@ skipping 56 matching lines @@
       return (((CPDF_Boolean*)this)->Identical((CPDF_Boolean*)pOther));
     case PDFOBJ_NUMBER:
       return (((CPDF_Number*)this)->Identical((CPDF_Number*)pOther));
     case PDFOBJ_STRING:
       return (((CPDF_String*)this)->Identical((CPDF_String*)pOther));
     case PDFOBJ_NAME:
       return (((CPDF_Name*)this)->Identical((CPDF_Name*)pOther));
     case PDFOBJ_ARRAY:
       return (((CPDF_Array*)this)->Identical((CPDF_Array*)pOther));
     case PDFOBJ_DICTIONARY:
-      return (((CPDF_Dictionary*)this)->Identical((CPDF_Dictionary*)pOther));
+      return this->AsDictionary()->Identical(pOther->AsDictionary());
     case PDFOBJ_NULL:
       return TRUE;
     case PDFOBJ_STREAM:
       return (((CPDF_Stream*)this)->Identical((CPDF_Stream*)pOther));
     case PDFOBJ_REFERENCE:
       return (((CPDF_Reference*)this)->Identical((CPDF_Reference*)pOther));
   }
   return FALSE;
 }
 CPDF_Object* CPDF_Object::GetDirect() const {
@@ skipping 28 matching lines @@
       CPDF_Array* pThis = (CPDF_Array*)this;
       int n = pThis->GetCount();
       for (int i = 0; i < n; i++) {
         CPDF_Object* value = (CPDF_Object*)pThis->m_Objects.GetAt(i);
         pCopy->m_Objects.Add(value->CloneInternal(bDirect, visited));
       }
       return pCopy;
     }
     case PDFOBJ_DICTIONARY: {
       CPDF_Dictionary* pCopy = new CPDF_Dictionary();
-      CPDF_Dictionary* pThis = (CPDF_Dictionary*)this;
+      const CPDF_Dictionary* pThis = this->AsDictionary();
       FX_POSITION pos = pThis->m_Map.GetStartPosition();
       while (pos) {
         CFX_ByteString key;
         CPDF_Object* value;
         pThis->m_Map.GetNextAssoc(pos, key, (void*&)value);
         pCopy->m_Map.SetAt(key, value->CloneInternal(bDirect, visited));
       }
       return pCopy;
     }
     case PDFOBJ_NULL: {
       return new CPDF_Null;
     }
     case PDFOBJ_STREAM: {
       CPDF_Stream* pThis = (CPDF_Stream*)this;
       CPDF_StreamAcc acc;
       acc.LoadAllData(pThis, TRUE);
       FX_DWORD streamSize = acc.GetSize();
       CPDF_Dictionary* pDict = pThis->GetDict();
-      if (pDict)
-        pDict = (CPDF_Dictionary*)((CPDF_Object*)pDict)
-                    ->CloneInternal(bDirect, visited);
+      if (pDict) {
+        pDict = ToDictionary(pDict->CloneInternal(bDirect, visited));
+      }
       return new CPDF_Stream(acc.DetachData(), streamSize, pDict);
     }
     case PDFOBJ_REFERENCE: {
       CPDF_Reference* pRef = (CPDF_Reference*)this;
       FX_DWORD obj_num = pRef->GetRefObjNum();
       if (bDirect && !visited->GetValueAt((void*)(uintptr_t)obj_num)) {
         visited->SetAt((void*)(uintptr_t)obj_num, (void*)1);
         if (!pRef->GetDirect())
           return nullptr;
 
@@ skipping 29 matching lines @@
 void CPDF_Object::SetUnicodeText(const FX_WCHAR* pUnicodes, int len) {
   if (m_Type == PDFOBJ_STRING) {
     ((CPDF_String*)this)->m_String = PDF_EncodeText(pUnicodes, len);
   } else if (m_Type == PDFOBJ_STREAM) {
     CFX_ByteString result = PDF_EncodeText(pUnicodes, len);
     ((CPDF_Stream*)this)
         ->SetData((uint8_t*)result.c_str(), result.GetLength(), FALSE, FALSE);
   }
 }
 
+CPDF_Dictionary* CPDF_Object::AsDictionary() {
+  return IsDictionary() ? static_cast<CPDF_Dictionary*>(this) : nullptr;
+}
+
+const CPDF_Dictionary* CPDF_Object::AsDictionary() const {
+  return IsDictionary() ? static_cast<const CPDF_Dictionary*>(this) : nullptr;
+}
+
 CPDF_Number::CPDF_Number(int value)
     : CPDF_Object(PDFOBJ_NUMBER), m_bInteger(TRUE), m_Integer(value) {}
 
 CPDF_Number::CPDF_Number(FX_FLOAT value)
     : CPDF_Object(PDFOBJ_NUMBER), m_bInteger(FALSE), m_Float(value) {}
 
 CPDF_Number::CPDF_Number(FX_BOOL bInteger, void* pData)
     : CPDF_Object(PDFOBJ_NUMBER),
       m_bInteger(bInteger),
       m_Integer(*(int*)pData) {}
@@ skipping 87 matching lines @@
     return 0;
   }
   CPDF_Object* p = (CPDF_Object*)m_Objects.GetAt(i);
   return p->GetNumber();
 }
 CPDF_Dictionary* CPDF_Array::GetDict(FX_DWORD i) const {
   CPDF_Object* p = GetElementValue(i);
   if (!p) {
     return NULL;
   }
-  if (p->GetType() == PDFOBJ_DICTIONARY) {
-    return (CPDF_Dictionary*)p;
+  if (CPDF_Dictionary* pDict = p->AsDictionary()) {
+    return pDict;
   }
   if (p->GetType() == PDFOBJ_STREAM) {
     return ((CPDF_Stream*)p)->GetDict();
   }
   return NULL;
 }
 CPDF_Stream* CPDF_Array::GetStream(FX_DWORD i) const {
   CPDF_Object* p = GetElementValue(i);
   if (p == NULL || p->GetType() != PDFOBJ_STREAM) {
     return NULL;
@@ skipping 199 matching lines @@
   if (p && p->GetType() == PDFOBJ_BOOLEAN) {
     return p->GetInteger();
   }
   return bDefault;
 }
 CPDF_Dictionary* CPDF_Dictionary::GetDict(const CFX_ByteStringC& key) const {
   CPDF_Object* p = GetElementValue(key);
   if (!p) {
     return nullptr;
   }
-  if (p->GetType() == PDFOBJ_DICTIONARY) {
-    return (CPDF_Dictionary*)p;
+  if (CPDF_Dictionary* pDict = p->AsDictionary()) {
+    return pDict;
   }
   if (p->GetType() == PDFOBJ_STREAM) {
     return ((CPDF_Stream*)p)->GetDict();
   }
   return nullptr;
 }
 CPDF_Array* CPDF_Dictionary::GetArray(const CFX_ByteStringC& key) const {
   CPDF_Object* p = GetElementValue(key);
   if (p == NULL || p->GetType() != PDFOBJ_ARRAY) {
     return NULL;
@@ skipping 520 matching lines @@
   }
   pObj->m_ObjNum = objnum;
   m_IndirectObjs.SetAt((void*)(uintptr_t)objnum, pObj);
   if (m_LastObjNum < objnum) {
     m_LastObjNum = objnum;
   }
 }
 FX_DWORD CPDF_IndirectObjects::GetLastObjNum() const {
   return m_LastObjNum;
 }