Remove "this==NULL" and adjust corresponding callers

fpdfsdk/src/fpdf_transformpage.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/fsdk_define.h"
 #include "../include/fpdf_transformpage.h"
 
 DLLEXPORT void STDCALL FPDFPage_SetMediaBox(FPDF_PAGE page, float left, float bottom, float right, float top)
@@ skipping 78 matching lines @@
         bsClipping.Format("%f %f %f %f re W* n ", rect.left, rect.bottom, rect.Width(), rect.Height());
         textBuf<<bsClipping;
 
         CFX_ByteString bsMatix;
         bsMatix.Format("%f %f %f %f %f %f cm ", matrix->a, matrix->b,matrix->c,matrix->d,matrix->e,matrix->f);
         textBuf<<bsMatix;
         
 
         CPDF_Page* pPage = (CPDF_Page*)page;
         CPDF_Dictionary* pPageDic = pPage->m_pFormDict;
-        CPDF_Object* pContentObj = pPageDic->GetElement("Contents");
+        CPDF_Object* pContentObj = pPageDic ? pPageDic->GetElement("Contents") : NULL;
         if(!pContentObj)
-                pContentObj = pPageDic->GetArray("Contents");
+                pContentObj = pPageDic ? pPageDic->GetArray("Contents") : NULL;
         if(!pContentObj)
                 return FALSE;
         
         CPDF_Dictionary* pDic = FX_NEW CPDF_Dictionary;
         CPDF_Stream* pStream = FX_NEW CPDF_Stream(NULL,0, pDic);
         pStream->SetData(textBuf.GetBuffer(), textBuf.GetSize(), FALSE, FALSE);
         CPDF_Document* pDoc = pPage->m_pDocument;
         if(!pDoc)
                 return FALSE;
         pDoc->AddIndirectObject(pStream);
@@ skipping 141 matching lines @@
                 }
         }
 }
 
 DLLEXPORT void STDCALL FPDFPage_InsertClipPath(FPDF_PAGE page,FPDF_CLIPPATH clipPath)
 {
         if(!page)
                 return;
         CPDF_Page* pPage = (CPDF_Page*)page;
         CPDF_Dictionary* pPageDic = pPage->m_pFormDict;
-        CPDF_Object* pContentObj = pPageDic->GetElement("Contents");
+        CPDF_Object* pContentObj = pPageDic ? pPageDic->GetElement("Contents") : NULL;
         if(!pContentObj)
-                pContentObj = pPageDic->GetArray("Contents");
+                pContentObj = pPageDic ? pPageDic->GetArray("Contents") : NULL;
         if(!pContentObj)
                 return;
 
         CFX_ByteTextBuf strClip;
         CPDF_ClipPath* pClipPath = (CPDF_ClipPath*)clipPath;
         FX_DWORD i;
         for (i = 0; i < pClipPath->GetPathCount(); i ++) {
                 CPDF_Path path = pClipPath->GetPath(i);
                 int iClipType = pClipPath->GetClipType(i);
                 if (path.GetPointCount() == 0) {
@@ skipping 40 matching lines @@
                         {
                                 pContentArray = FX_NEW CPDF_Array();
                                 pContentArray->AddReference(pDoc,pStream->GetObjNum());
                                 pContentArray->AddReference(pDoc,pDirectObj->GetObjNum());
                                 pPageDic->SetAtReference("Contents", pDoc, pDoc->AddIndirectObject(pContentArray));
                         }
                 }
         }       
 }