Fixup CPDFSDK_PageView and CPDF_Page interactions.

fpdfsdk/fpdfview.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/fpdfview.h"
 
 #include <memory>
 
@@ skipping 655 matching lines @@
 
 DLLEXPORT void STDCALL FPDF_ClosePage(FPDF_PAGE page) {
   UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
   if (!page)
     return;
 #ifdef PDF_ENABLE_XFA
   pPage->Release();
 #else   // PDF_ENABLE_XFA
   CPDFSDK_PageView* pPageView =
       static_cast<CPDFSDK_PageView*>(pPage->GetView());
-  if (pPageView && pPageView->IsLocked()) {
-    pPageView->TakeOverPage();
-    return;
+  if (pPageView) {
+    if (pPageView->IsLocked()) {
+      pPageView->TakePageOwnership();
+      return;
+    }
+
+    bool owned = pPageView->OwnsPage();
+    // This will delete the |pPageView| object. We must cleanup the PageView
+    // first because it will attempt to reset the View on the |pPage| during
+    // destruction.
+    pPageView->GetSDKDocument()->RemovePageView(pPage);
+    // If the page was owned then the pageview will have deleted the page.
+    if (owned)
+      return;
   }
   delete pPage;
 #endif  // PDF_ENABLE_XFA
 }
 
 DLLEXPORT void STDCALL FPDF_CloseDocument(FPDF_DOCUMENT document) {
   delete UnderlyingFromFPDFDocument(document);
 }
 
 DLLEXPORT unsigned long STDCALL FPDF_GetLastError() {
@@ skipping 428 matching lines @@
   if (!buffer) {
     *buflen = len;
   } else if (*buflen >= len) {
     memcpy(buffer, utf16Name.c_str(), len);
     *buflen = len;
   } else {
     *buflen = -1;
   }
   return (FPDF_DEST)pDestObj;
 }