Remove "this==NULL" and adjust corresponding callers

core/src/fpdfapi/fpdf_edit/fpdf_edit_content.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_serial.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fxcodec/fx_codec.h"
@@ skipping 30 matching lines @@
 {
     CFX_ByteTextBuf buf;
     CPDF_Dictionary* pPageDict = m_pPage->m_pFormDict;
     for (int i = 0; i < m_pageObjects.GetSize(); ++i) {
         CPDF_PageObject* pPageObj = (CPDF_PageObject*)m_pageObjects[i];
         if (!pPageObj || pPageObj->m_Type != PDFPAGE_IMAGE) {
             continue;
         }
         ProcessImage(buf, (CPDF_ImageObject*)pPageObj);
     }
-    CPDF_Object* pContent = pPageDict->GetElementValue("Contents");
+    CPDF_Object* pContent = pPageDict ? pPageDict->GetElementValue("Contents") : NULL;
     if (pContent != NULL) {
         pPageDict->RemoveAt("Contents");
     }
     CPDF_Stream* pStream = FX_NEW CPDF_Stream(NULL, 0, NULL);
     pStream->SetData(buf.GetBuffer(), buf.GetLength(), FALSE, FALSE);
     m_pDocument->AddIndirectObject(pStream);
     pPageDict->SetAtReference("Contents", m_pDocument, pStream->GetObjNum());
 }
 CFX_ByteString CPDF_PageContentGenerate::RealizeResource(CPDF_Object* pResourceObj, const FX_CHAR* szType)
 {
@@ skipping 25 matching lines @@
     if ((pImageObj->m_Matrix.a == 0 && pImageObj->m_Matrix.b == 0) ||
             (pImageObj->m_Matrix.c == 0 && pImageObj->m_Matrix.d == 0)) {
         return;
     }
     buf << "q " << pImageObj->m_Matrix << " cm ";
     if (!pImageObj->m_pImage->IsInline()) {
         CPDF_Stream* pStream = pImageObj->m_pImage->GetStream();
         FX_DWORD dwSavedObjNum = pStream->GetObjNum();
         CFX_ByteString name = RealizeResource(pStream, "XObject");
         if (dwSavedObjNum == 0) {
-            pImageObj->m_pImage->Release();
+            if (pImageObj->m_pImage)
+                pImageObj->m_pImage->Release();
             pImageObj->m_pImage = m_pDocument->GetPageData()->GetImage(pStream);
         }
         buf << "/" << PDF_NameEncode(name) << " Do Q\n";
     }
 }
 void CPDF_PageContentGenerate::ProcessForm(CFX_ByteTextBuf& buf, FX_LPCBYTE data, FX_DWORD size, CFX_Matrix& matrix)
 {
     if (!data || !size) {
         return;
     }
     CPDF_Stream* pStream = FX_NEW CPDF_Stream(NULL, 0, NULL);
     CPDF_Dictionary* pFormDict = CPDF_Dictionary::Create();
     pFormDict->SetAtName(FX_BSTR("Type"), FX_BSTR("XObject"));
     pFormDict->SetAtName(FX_BSTR("Subtype"), FX_BSTR("Form"));
     CFX_FloatRect bbox = m_pPage->GetPageBBox();
     matrix.TransformRect(bbox);
     pFormDict->SetAtRect(FX_BSTR("BBox"), bbox);
     pStream->InitStream((FX_LPBYTE)data, size, pFormDict);
     buf << "q " << matrix << " cm ";
     CFX_ByteString name = RealizeResource(pStream, "XObject");
     buf << "/" << PDF_NameEncode(name) << " Do Q\n";
 }
 void CPDF_PageContentGenerate::TransformContent(CFX_Matrix& matrix)
 {
-    CPDF_Object* pContent = m_pPage->m_pFormDict->GetElementValue("Contents");
+    CPDF_Dictionary* pDict = m_pPage->m_pFormDict;
+    CPDF_Object* pContent = pDict ? pDict->GetElementValue("Contents") : NULL;
     if (!pContent) {
         return;
     }
     CFX_ByteTextBuf buf;
     int type = pContent->GetType();
     if (type == PDFOBJ_ARRAY) {
         CPDF_Array* pArray = (CPDF_Array*)pContent;
         int iCount = pArray->GetCount();
         CPDF_StreamAcc** pContentArray = (CPDF_StreamAcc**)FX_Alloc(CPDF_StreamAcc*, iCount);
         int size = 0;
@@ skipping 22 matching lines @@
     } else if (type == PDFOBJ_STREAM) {
         CPDF_StreamAcc contentStream;
         contentStream.LoadAllData((CPDF_Stream*)pContent);
         ProcessForm(buf, contentStream.GetData(), contentStream.GetSize(), matrix);
     }
     CPDF_Stream* pStream = FX_NEW CPDF_Stream(NULL, 0, NULL);
     pStream->SetData(buf.GetBuffer(), buf.GetLength(), FALSE, FALSE);
     m_pDocument->AddIndirectObject(pStream);
     m_pPage->m_pFormDict->SetAtReference("Contents", m_pDocument, pStream->GetObjNum());
 }