Introduce CPDFPageFromFPDFPage()

fpdfsdk/src/fpdfeditimg.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 "../../public/fpdf_edit.h"
 #include "../include/fsdk_define.h"
 
 DLLEXPORT FPDF_PAGEOBJECT STDCALL
@@ skipping 12 matching lines @@
                           int nCount,
                           FPDF_PAGEOBJECT image_object,
                           FPDF_FILEACCESS* fileAccess) {
   if (!image_object || !fileAccess || !pages)
     return FALSE;
 
   IFX_FileRead* pFile = new CPDF_CustomAccess(fileAccess);
   CPDF_ImageObject* pImgObj = (CPDF_ImageObject*)image_object;
   pImgObj->m_GeneralState.GetModify();
   for (int index = 0; index < nCount; index++) {
-    CPDF_Page* pPage = (CPDF_Page*)pages[index];
+    CPDF_Page* pPage = CPDFPageFromFPDFPage(pages[index]);
+    if (!pPage)
+      continue;
     pImgObj->m_pImage->ResetCache(pPage, NULL);
   }
   pImgObj->m_pImage->SetJpegImage(pFile);
 
   return TRUE;
 }
 
 DLLEXPORT FPDF_BOOL STDCALL FPDFImageObj_SetMatrix(FPDF_PAGEOBJECT image_object,
                                                    double a,
                                                    double b,
@@ skipping 18 matching lines @@
                                                    int nCount,
                                                    FPDF_PAGEOBJECT image_object,
                                                    FPDF_BITMAP bitmap) {
   if (!image_object || !bitmap || !pages)
     return FALSE;
   CFX_DIBitmap* pBmp = NULL;
   pBmp = (CFX_DIBitmap*)bitmap;
   CPDF_ImageObject* pImgObj = (CPDF_ImageObject*)image_object;
   pImgObj->m_GeneralState.GetModify();
   for (int index = 0; index < nCount; index++) {
-    CPDF_Page* pPage = (CPDF_Page*)pages[index];
+    CPDF_Page* pPage = CPDFPageFromFPDFPage(pages[index]);
+    if (!pPage)
+      continue;
     pImgObj->m_pImage->ResetCache(pPage, NULL);
   }
   pImgObj->m_pImage->SetImage(pBmp, FALSE);
   pImgObj->CalcBoundingBox();
   return TRUE;
 }