diff --git a/fpdfsdk/include/jsapi/fxjs_v8.h b/fpdfsdk/include/jsapi/fxjs_v8.h
index 3499bfb..a154159 100644
--- a/fpdfsdk/include/jsapi/fxjs_v8.h
+++ b/fpdfsdk/include/jsapi/fxjs_v8.h
@@ -125,9 +125,7 @@
 void FXJS_SetPrivate(v8::Isolate* pIsolate,
                      v8::Local<v8::Object> pObj,
                      void* p);
-void FXJS_SetPrivate(v8::Local<v8::Object> pObj, void* p);
 void* FXJS_GetPrivate(v8::Isolate* pIsolate, v8::Local<v8::Object> pObj);
-void* FXJS_GetPrivate(v8::Local<v8::Object> pObj);
 void FXJS_FreePrivate(void* p);
 void FXJS_FreePrivate(v8::Local<v8::Object> pObj);
 
diff --git a/fpdfsdk/src/javascript/Document.cpp b/fpdfsdk/src/javascript/Document.cpp
index bccf08b..105e487 100644
--- a/fpdfsdk/src/javascript/Document.cpp
+++ b/fpdfsdk/src/javascript/Document.cpp
@@ -1467,7 +1467,7 @@
     if (pObj.IsEmpty())
       return FALSE;
 
-    CJS_Icon* pJS_Icon = (CJS_Icon*)FXJS_GetPrivate(pObj);
+    CJS_Icon* pJS_Icon = (CJS_Icon*)FXJS_GetPrivate(m_isolate, pObj);
     if (!pJS_Icon)
       return FALSE;
 
@@ -1511,7 +1511,7 @@
       if (pObj.IsEmpty())
         return FALSE;
 
-      CJS_Icon* pJS_Icon = (CJS_Icon*)FXJS_GetPrivate(pObj);
+      CJS_Icon* pJS_Icon = (CJS_Icon*)FXJS_GetPrivate(m_isolate, pObj);
       if (!pJS_Icon)
         return FALSE;
 
diff --git a/fpdfsdk/src/javascript/Field.cpp b/fpdfsdk/src/javascript/Field.cpp
index 52f6321..266f295 100644
--- a/fpdfsdk/src/javascript/Field.cpp
+++ b/fpdfsdk/src/javascript/Field.cpp
@@ -3300,8 +3300,6 @@
     return FALSE;
 
   CPDF_FormField* pFormField = (CPDF_FormField*)FieldArray.ElementAt(0);
-  ASSERT(pFormField != NULL);
-
   if (pFormField->GetFieldType() != FIELDTYPE_PUSHBUTTON)
     return FALSE;
 
@@ -3310,17 +3308,13 @@
     return FALSE;
 
   CJS_Context* pContext = (CJS_Context*)cc;
-  ASSERT(pContext != NULL);
-
   CJS_Runtime* pRuntime = pContext->GetJSRuntime();
-  ASSERT(pRuntime != NULL);
-
   v8::Local<v8::Object> pObj =
       FXJS_NewFxDynamicObj(pRuntime->GetIsolate(), pContext,
                            FXJS_GetObjDefnID(pRuntime->GetIsolate(), L"Icon"));
   ASSERT(pObj.IsEmpty() == FALSE);
 
-  CJS_Icon* pJS_Icon = (CJS_Icon*)FXJS_GetPrivate(pObj);
+  CJS_Icon* pJS_Icon = (CJS_Icon*)FXJS_GetPrivate(pRuntime->GetIsolate(), pObj);
   Icon* pIcon = (Icon*)pJS_Icon->GetEmbedObject();
 
   CPDF_Stream* pIconStream = NULL;
@@ -3339,8 +3333,6 @@
   return TRUE;
 }
 
-//#pragma warning(default: 4800)
-
 FX_BOOL Field::buttonImportIcon(IFXJS_Context* cc,
                                 const CJS_Parameters& params,
                                 CJS_Value& vRet,
@@ -3526,22 +3518,20 @@
 
   CJS_Array FormFieldArray(m_isolate);
   for (int j = 0, jsz = swSort.GetSize(); j < jsz; j++) {
-    CFX_WideString* pStr = swSort.GetAt(j);
-
+    nonstd::unique_ptr<CFX_WideString> pStr(swSort.GetAt(j));
     v8::Local<v8::Object> pObj = FXJS_NewFxDynamicObj(
         pRuntime->GetIsolate(), pContext,
         FXJS_GetObjDefnID(pRuntime->GetIsolate(), L"Field"));
     ASSERT(pObj.IsEmpty() == FALSE);
 
-    CJS_Field* pJSField = (CJS_Field*)FXJS_GetPrivate(pObj);
+    CJS_Field* pJSField =
+        (CJS_Field*)FXJS_GetPrivate(pRuntime->GetIsolate(), pObj);
     Field* pField = (Field*)pJSField->GetEmbedObject();
     pField->AttachField(m_pJSDoc, *pStr);
 
     CJS_Value FormFieldValue(m_isolate);
     FormFieldValue = pJSField;
     FormFieldArray.SetElement(j, FormFieldValue);
-
-    delete pStr;
   }
 
   vRet = FormFieldArray;
diff --git a/fpdfsdk/src/javascript/JS_EventHandler.cpp b/fpdfsdk/src/javascript/JS_EventHandler.cpp
index bd762b4..553fc95 100644
--- a/fpdfsdk/src/javascript/JS_EventHandler.cpp
+++ b/fpdfsdk/src/javascript/JS_EventHandler.cpp
@@ -611,10 +611,7 @@
 }
 
 Field* CJS_EventHandler::Source() {
-  ASSERT(m_pJSContext != NULL);
-
   CJS_Runtime* pRuntime = m_pJSContext->GetJSRuntime();
-
   v8::Local<v8::Object> pDocObj = FXJS_NewFxDynamicObj(
       pRuntime->GetIsolate(), m_pJSContext,
       FXJS_GetObjDefnID(pRuntime->GetIsolate(), L"Document"));
@@ -624,32 +621,21 @@
                            FXJS_GetObjDefnID(pRuntime->GetIsolate(), L"Field"));
   ASSERT(pFieldObj.IsEmpty() == FALSE);
 
-  CJS_Document* pJSDocument = (CJS_Document*)FXJS_GetPrivate(pDocObj);
+  CJS_Document* pJSDocument =
+      (CJS_Document*)FXJS_GetPrivate(pRuntime->GetIsolate(), pDocObj);
   Document* pDocument = (Document*)pJSDocument->GetEmbedObject();
-  if (m_pTargetDoc != NULL)
-    pDocument->AttachDoc(m_pTargetDoc);
-  else
-    pDocument->AttachDoc(m_pJSContext->GetReaderDocument());
+  pDocument->AttachDoc(m_pTargetDoc ? m_pTargetDoc
+                                    : m_pJSContext->GetReaderDocument());
 
-  // if (m_pSourceField == NULL)
-  //  return NULL;
-  // CRAO_Widget *pWidget = IBCL_Widget::GetWidget(m_pSourceField);
-  // CPDF_FormField* pFormField = pWidget->GetFormField();
-  // ASSERT(pFormField);
-  // CFX_WideString csFieldName = pFormField->GetFullName();
-  CJS_Field* pJSField = (CJS_Field*)FXJS_GetPrivate(pFieldObj);
-  ASSERT(pJSField != NULL);
+  CJS_Field* pJSField =
+      (CJS_Field*)FXJS_GetPrivate(pRuntime->GetIsolate(), pFieldObj);
   Field* pField = (Field*)pJSField->GetEmbedObject();
-  ASSERT(pField != NULL);
   pField->AttachField(pDocument, m_strSourceName);
   return pField;
 }
 
 Field* CJS_EventHandler::Target_Field() {
-  ASSERT(m_pJSContext != NULL);
-
   CJS_Runtime* pRuntime = m_pJSContext->GetJSRuntime();
-
   v8::Local<v8::Object> pDocObj = FXJS_NewFxDynamicObj(
       pRuntime->GetIsolate(), m_pJSContext,
       FXJS_GetObjDefnID(pRuntime->GetIsolate(), L"Document"));
@@ -659,19 +645,15 @@
                            FXJS_GetObjDefnID(pRuntime->GetIsolate(), L"Field"));
   ASSERT(pFieldObj.IsEmpty() == FALSE);
 
-  CJS_Document* pJSDocument = (CJS_Document*)FXJS_GetPrivate(pDocObj);
+  CJS_Document* pJSDocument =
+      (CJS_Document*)FXJS_GetPrivate(pRuntime->GetIsolate(), pDocObj);
   Document* pDocument = (Document*)pJSDocument->GetEmbedObject();
-  if (m_pTargetDoc != NULL)
-    pDocument->AttachDoc(m_pTargetDoc);
-  else
-    pDocument->AttachDoc(m_pJSContext->GetReaderDocument());
+  pDocument->AttachDoc(m_pTargetDoc ? m_pTargetDoc
+                                    : m_pJSContext->GetReaderDocument());
 
-  CJS_Field* pJSField = (CJS_Field*)FXJS_GetPrivate(pFieldObj);
-  ASSERT(pJSField != NULL);
-
+  CJS_Field* pJSField =
+      (CJS_Field*)FXJS_GetPrivate(pRuntime->GetIsolate(), pFieldObj);
   Field* pField = (Field*)pJSField->GetEmbedObject();
-  ASSERT(pField != NULL);
-
   pField->AttachField(pDocument, m_strTargetName);
   return pField;
 }
diff --git a/fpdfsdk/src/javascript/JS_Runtime.cpp b/fpdfsdk/src/javascript/JS_Runtime.cpp
index bbe9f6e..643cefb 100644
--- a/fpdfsdk/src/javascript/JS_Runtime.cpp
+++ b/fpdfsdk/src/javascript/JS_Runtime.cpp
@@ -205,7 +205,7 @@
         if (FXJS_GetObjDefnID(pThis) ==
             FXJS_GetObjDefnID(GetIsolate(), L"Document")) {
           if (CJS_Document* pJSDocument =
-                  (CJS_Document*)FXJS_GetPrivate(pThis)) {
+                  (CJS_Document*)FXJS_GetPrivate(GetIsolate(), pThis)) {
             if (Document* pDocument = (Document*)pJSDocument->GetEmbedObject())
               pDocument->AttachDoc(pReaderDoc);
           }
diff --git a/fpdfsdk/src/jsapi/fxjs_v8.cpp b/fpdfsdk/src/jsapi/fxjs_v8.cpp
index 1906411..6349ca3 100644
--- a/fpdfsdk/src/jsapi/fxjs_v8.cpp
+++ b/fpdfsdk/src/jsapi/fxjs_v8.cpp
@@ -497,13 +497,6 @@
     return kFXJSValueNameUndefined;
   return NULL;
 }
-void FXJS_SetPrivate(v8::Local<v8::Object> pObj, void* p) {
-  FXJS_SetPrivate(NULL, pObj, p);
-}
-
-void* FXJS_GetPrivate(v8::Local<v8::Object> pObj) {
-  return FXJS_GetPrivate(NULL, pObj);
-}
 
 void FXJS_SetPrivate(v8::Isolate* pIsolate,
                      v8::Local<v8::Object> pObj,
@@ -519,24 +512,21 @@
 
 void* FXJS_GetPrivate(v8::Isolate* pIsolate, v8::Local<v8::Object> pObj) {
   if (pObj.IsEmpty())
-    return NULL;
-  CFXJS_PrivateData* pPrivateData = NULL;
-  if (pObj->InternalFieldCount())
+    return nullptr;
+  CFXJS_PrivateData* pPrivateData = nullptr;
+  if (pObj->InternalFieldCount()) {
     pPrivateData =
         (CFXJS_PrivateData*)pObj->GetAlignedPointerFromInternalField(0);
-  else {
+  } else {
     // It could be a global proxy object.
     v8::Local<v8::Value> v = pObj->GetPrototype();
-    v8::Isolate* isolate = (v8::Isolate*)pIsolate;
-    v8::Local<v8::Context> context = isolate->GetCurrentContext();
+    v8::Local<v8::Context> context = pIsolate->GetCurrentContext();
     if (v->IsObject())
       pPrivateData = (CFXJS_PrivateData*)v->ToObject(context)
                          .ToLocalChecked()
                          ->GetAlignedPointerFromInternalField(0);
   }
-  if (!pPrivateData)
-    return NULL;
-  return pPrivateData->pPrivate;
+  return pPrivateData ? pPrivateData->pPrivate : nullptr;
 }
 
 void FXJS_FreePrivate(void* pPrivateData) {