Protect against unexpected library create/destroy

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>
 #include <utility>
@@ skipping 32 matching lines @@
 #include "public/fpdf_formfill.h"
 #include "xfa/fxbarcode/BC_Library.h"
 #endif  // PDF_ENABLE_XFA
 
 #if _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
 #include "core/fxge/cfx_windowsdevice.h"
 #endif
 
 namespace {
 
+// Also indicates whether library is currently initialized.
+CCodec_ModuleMgr* g_pCodecModule = nullptr;
+
 void RenderPageImpl(CPDF_PageRenderContext* pContext,
                     CPDF_Page* pPage,
                     const CFX_Matrix& matrix,
                     const FX_RECT& clipping_rect,
                     int flags,
                     bool bNeedToRestore,
                     IFSDK_PAUSE_Adapter* pause) {
   if (!pContext->m_pOptions)
     pContext->m_pOptions = pdfium::MakeUnique<CPDF_RenderOptions>();
 
@@ skipping 225 matching lines @@
 
 FPDF_BOOL FSDK_IsSandBoxPolicyEnabled(FPDF_DWORD policy) {
   switch (policy) {
     case FPDF_POLICY_MACHINETIME_ACCESS:
       return !!(foxit_sandbox_policy & 0x01);
     default:
       return false;
   }
 }
 
-CCodec_ModuleMgr* g_pCodecModule = nullptr;
-
 DLLEXPORT void STDCALL FPDF_InitLibrary() {
   FPDF_InitLibraryWithConfig(nullptr);
 }
 
 DLLEXPORT void STDCALL
 FPDF_InitLibraryWithConfig(const FPDF_LIBRARY_CONFIG* cfg) {
+  if (g_pCodecModule)
+    return;
+
   g_pCodecModule = new CCodec_ModuleMgr();
 
   CFX_GEModule* pModule = CFX_GEModule::Get();
   pModule->Init(cfg ? cfg->m_pUserFontPaths : nullptr, g_pCodecModule);
+
   CPDF_ModuleMgr* pModuleMgr = CPDF_ModuleMgr::Get();
   pModuleMgr->SetCodecModule(g_pCodecModule);
   pModuleMgr->InitPageModule();
   pModuleMgr->LoadEmbeddedGB1CMaps();
   pModuleMgr->LoadEmbeddedJapan1CMaps();
   pModuleMgr->LoadEmbeddedCNS1CMaps();
   pModuleMgr->LoadEmbeddedKorea1CMaps();
 
 #ifdef PDF_ENABLE_XFA
   FXJSE_Initialize();
   BC_Library_Init();
 #endif  // PDF_ENABLE_XFA
   if (cfg && cfg->version >= 2)
     IJS_Runtime::Initialize(cfg->m_v8EmbedderSlot, cfg->m_pIsolate);
 }
 
 DLLEXPORT void STDCALL FPDF_DestroyLibrary() {
+  if (!g_pCodecModule)
+    return;
+
 #ifdef PDF_ENABLE_XFA
   BC_Library_Destory();
   FXJSE_Finalize();
 #endif  // PDF_ENABLE_XFA
 
   CPDF_ModuleMgr::Destroy();
   CFX_GEModule::Destroy();
 
   delete g_pCodecModule;
   g_pCodecModule = nullptr;
@@ skipping 832 matching lines @@
   if (!buffer) {
     *buflen = len;
   } else if (len <= *buflen) {
     memcpy(buffer, utf16Name.c_str(), len);
     *buflen = len;
   } else {
     *buflen = -1;
   }
   return (FPDF_DEST)pDestObj;
 }