Add type cast definitions for CPDF_Reference.

core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp

Index: core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
index 3295b7f9e034875582758e7efa8cffddfc95c80d..86082357aee10af1a58e9f4b9b88c501cf0b04f1 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
@@ -671,51 +671,33 @@ 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;
-    }
-    if (m_pResources == m_pPageResources) {
-      CPDF_Dictionary* pList = m_pResources->GetDict(FX_BSTRC("XObject"));
-      if (pList == NULL) {
+
+    CPDF_Dictionary* pList = m_pResources->GetDict(FX_BSTRC("XObject"));
+    if (!pList) {
+      if (m_pResources == m_pPageResources || !m_pPageResources)
         return;
-      }
-      pRes = pList->GetElement(name);
-      if (pRes == NULL || pRes->GetType() != PDFOBJ_REFERENCE) {
+      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;
-      }
-    } 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;