Add type cast definitions for CPDF_Reference.

core/src/fpdfapi/fpdf_page/fpdf_page_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_page.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fpdfapi/fpdf_serial.h"
 #include "pageint.h"
@@ skipping 653 matching lines @@
 void CPDF_StreamContentParser::Handle_SetCachedDevice() {
   for (int i = 0; i < 6; i++) {
     m_Type3Data[i] = GetNumber(5 - i);
   }
   m_bColored = FALSE;
 }
 void CPDF_StreamContentParser::Handle_ExecuteXObject() {
   CFX_ByteString name = GetString(0);
   if (name == m_LastImageName && m_pLastImage && m_pLastImage->GetStream() &&
       m_pLastImage->GetStream()->GetObjNum()) {
-    AddImage(NULL, m_pLastImage, FALSE);
+    AddImage(nullptr, m_pLastImage, FALSE);
     return;
   }
+
   if (m_Options.m_bTextOnly) {
-    CPDF_Object* pRes = NULL;
-    if (m_pResources == NULL) {
+    CPDF_Object* pRes = nullptr;

[Lei Zhang, 2015/10/22 21:26:51]

move this down to where it's used

[Tom Sepez, 2015/10/22 21:49:14]

nit: Move this down and combine with initialization at 691

[dsinclair, 2015/10/26 13:55:44]

Done.

[dsinclair, 2015/10/26 13:55:44]

Done.

+    if (!m_pResources)
       return;
+
+    CPDF_Dictionary* pList = m_pResources->GetDict(FX_BSTRC("XObject"));
+    if (!pList) {
+      if (m_pResources == m_pPageResources || !m_pPageResources)
+        return;
+      CPDF_Dictionary* pList = m_pPageResources->GetDict(FX_BSTRC("XObject"));

[Lei Zhang, 2015/10/22 21:26:51]

There's a shadow variable here.

[Tom Sepez, 2015/10/22 21:49:13]

Argh, shadowing of pList at 683!  This would be a bug. Otherwise we segv at 691
when this is present and it goes out of scope.

[dsinclair, 2015/10/26 13:55:44]

Mistake in my simplification. Should not have been re-declared.

+      if (!pList)
+        return;
     }
-    if (m_pResources == m_pPageResources) {
-      CPDF_Dictionary* pList = m_pResources->GetDict(FX_BSTRC("XObject"));
-      if (pList == NULL) {
-        return;
-      }
-      pRes = pList->GetElement(name);
-      if (pRes == NULL || pRes->GetType() != PDFOBJ_REFERENCE) {
-        return;
-      }
-    } else {
-      CPDF_Dictionary* pList = m_pResources->GetDict(FX_BSTRC("XObject"));
-      if (pList == NULL) {
-        if (m_pPageResources == NULL) {
-          return;
-        }
-        CPDF_Dictionary* pList = m_pPageResources->GetDict(FX_BSTRC("XObject"));
-        if (pList == NULL) {
-          return;
-        }
-        pRes = pList->GetElement(name);
-        if (pRes == NULL || pRes->GetType() != PDFOBJ_REFERENCE) {
-          return;
-        }
-      } else {
-        pRes = pList->GetElement(name);
-        if (pRes == NULL || pRes->GetType() != PDFOBJ_REFERENCE) {
-          return;
-        }
-      }
-    }
+    pRes = pList->GetElement(name);

[Tom Sepez, 2015/10/22 21:49:13]

nit: maybe 
   CPDF_Reference* pRes = ToReference(pList->GetElement(name));

[dsinclair, 2015/10/26 13:55:44]

Done.

+    if (!ToReference(pRes))
+      return;
+

[Tom Sepez, 2015/10/22 21:49:14]

And I think the whole thing reduces down to this (but doublecheck), and I think
this reads more clearly.

CPDF_Dictionary* pList = m_pResources->GetDict(FX_BSTRC("XObject"));
if (!pList && m_pPageResources && m_pResources != m_pPageResources)
  pList = m_pPageResources->GetDict(FX_BSTRC("XObject"));
if (!pList)
  return;
CPDF_Resource* pRes = ToReference(pList->GetElement(name));
if (!pRes)
  return;

[dsinclair, 2015/10/26 13:55:44]

Done.

     FX_BOOL bForm;
-    if (m_pDocument->IsFormStream(((CPDF_Reference*)pRes)->GetRefObjNum(),
-                                  bForm) &&
-        !bForm) {
+    if (m_pDocument->IsFormStream(pRes->AsReference()->GetRefObjNum(), bForm) &&

[Tom Sepez, 2015/10/22 21:49:14]

nit: then you can lose the redundant AsReference here.

[dsinclair, 2015/10/26 13:55:44]

Done.

+        !bForm)
       return;
-    }
   }
+
   CPDF_Stream* pXObject = ToStream(FindResourceObj(FX_BSTRC("XObject"), name));
   if (!pXObject) {
     m_bResourceMissing = TRUE;
     return;
   }
 
   CFX_ByteStringC type =
       pXObject->GetDict()
           ? pXObject->GetDict()->GetConstString(FX_BSTRC("Subtype"))
           : CFX_ByteStringC();
@@ skipping 857 matching lines @@
         buf.AppendChar((char)code);
       }
       bFirst = !bFirst;
     }
   }
   if (!bFirst) {
     buf.AppendChar((char)code);
   }
   return buf.GetByteString();
 }