Do not check pointers before deleting them.

xfa/fxjse/context.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 "xfa/fxjse/context.h"
 
 #include "xfa/fxjse/class.h"
 #include "xfa/fxjse/scope_inline.h"
 #include "xfa/fxjse/util_inline.h"
 #include "xfa/fxjse/value.h"
 
 FXJSE_HCONTEXT FXJSE_Context_Create(FXJSE_HRUNTIME hRuntime,
                                     const FXJSE_CLASS* lpGlobalClass,
                                     void* lpGlobalObject) {
   CFXJSE_Context* pContext = CFXJSE_Context::Create(
       reinterpret_cast<v8::Isolate*>(hRuntime), lpGlobalClass, lpGlobalObject);
   return reinterpret_cast<FXJSE_HCONTEXT>(pContext);
 }
 
 void FXJSE_Context_Release(FXJSE_HCONTEXT hContext) {
-  CFXJSE_Context* pContext = reinterpret_cast<CFXJSE_Context*>(hContext);
-  if (pContext) {
-    delete pContext;
-  }
+  delete hContext;

[Tom Sepez, 2016/04/28 21:47:23]

No, there's a brutal reinterpret cast going on here, the various hTypes are
usually pointers to struct { void* data; } that are blatantly cast to the actual
underlying types.

[Lei Zhang, 2016/04/28 22:31:10]

Done.

 }
 
 FXJSE_HVALUE FXJSE_Context_GetGlobalObject(FXJSE_HCONTEXT hContext) {
   CFXJSE_Context* pContext = reinterpret_cast<CFXJSE_Context*>(hContext);
   if (!pContext) {
     return NULL;
   }
   CFXJSE_Value* lpValue = CFXJSE_Value::Create(pContext->GetRuntime());
   ASSERT(lpValue);
   pContext->GetGlobalObject(lpValue);
@@ skipping 108 matching lines @@
       pIsolate, CFXJSE_RuntimeData::Get(pIsolate)->m_hRootContext);
   hNewContext->SetSecurityToken(hRootContext->GetSecurityToken());
   v8::Local<v8::Object> hGlobalObject =
       FXJSE_GetGlobalObjectFromContext(hNewContext);
   FXJSE_UpdateObjectBinding(hGlobalObject, lpGlobalObject);
   pContext->m_hContext.Reset(pIsolate, hNewContext);
   return pContext;
 }
 
 CFXJSE_Context::~CFXJSE_Context() {
-  for (int32_t i = 0, count = m_rgClasses.GetSize(); i < count; i++) {
-    CFXJSE_Class* pClass = m_rgClasses[i];
-    if (pClass) {
-      delete pClass;
-    }
-  }
+  for (int32_t i = 0, count = m_rgClasses.GetSize(); i < count; i++)
+    delete m_rgClasses[i];
   m_rgClasses.RemoveAll();
 }
 
 void CFXJSE_Context::GetGlobalObject(CFXJSE_Value* pValue) {
   ASSERT(pValue);
   CFXJSE_ScopeUtil_IsolateHandleContext scope(this);
   v8::Local<v8::Context> hContext =
       v8::Local<v8::Context>::New(m_pIsolate, m_hContext);
   v8::Local<v8::Object> hGlobalObject = hContext->Global();
   pValue->ForceSetValue(hGlobalObject);
@@ skipping 43 matching lines @@
         return TRUE;
       }
     }
     if (lpRetValue) {
       lpRetValue->m_hValue.Reset(m_pIsolate,
                                  FXJSE_CreateReturnValue(m_pIsolate, trycatch));
     }
     return FALSE;
   }
 }