Check the validity of pointers before they are utilized

fpdfsdk/src/fpdfppo.cpp

Index: fpdfsdk/src/fpdfppo.cpp
diff --git a/fpdfsdk/src/fpdfppo.cpp b/fpdfsdk/src/fpdfppo.cpp
index b8d2125b7dab667e0e0d9d50aa708474309757b6..a5c42756484063829d7314882b1e2c104743415d 100644
--- a/fpdfsdk/src/fpdfppo.cpp
+++ b/fpdfsdk/src/fpdfppo.cpp
@@ -313,9 +313,17 @@ int	CPDF_PageOrganizer::GetNewObjId(CPDF_Document *pDoc, CFX_MapPtrToPtr* pMapPt
 	}
 	else
 	{
-		CPDF_Object* pClone  = pRef->GetDirect()->Clone();
-		if(!pClone)			
+		CPDF_Object* pDirect = pRef->GetDirect();
+		if(!pDirect)
+		{
+			return 0;
+		}
+
+		CPDF_Object* pClone = pDirect->Clone();
+		if(!pClone)
+		{
 			return 0;
+		}
 		
 		if(pClone->GetType() == PDFOBJ_DICTIONARY)
 		{