Fix an out-of-boundary issue for wide string

fpdfsdk/src/javascript/app.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 "../../include/javascript/JavaScript.h"
 #include "../../include/javascript/IJavaScript.h"
 #include "../../include/javascript/JS_Define.h"
 #include "../../include/javascript/JS_Object.h"
@@ skipping 868 matching lines @@
         v8::Isolate* isolate = GetIsolate(cc);
 
         bool bSave = false;
         CFX_ByteString cFilenameInit = CFX_ByteString();
         CFX_ByteString cFSInit = CFX_ByteString();
 
         if(params.size()>0 && (params[0].GetType() == VT_object))
         {
                 JSObject pObj = (JSObject )params[0];
 
-                v8::Handle<v8::Value> pValue = JS_GetObjectElement(isolate,pObj,L"bSave");
-                        bSave = (bool)CJS_Value(isolate,pValue,GET_VALUE_TYPE(pValue));
-                
+                v8::Handle<v8::Value> pValue = JS_GetObjectElement(isolate,pObj,L"bSave");
+                        bSave = (bool)CJS_Value(isolate,pValue,GET_VALUE_TYPE(pValue));
+                
                 pValue = JS_GetObjectElement(isolate, pObj,L"cFilenameInit");
                 {
                         CJS_Value t = CJS_Value(isolate, pValue, GET_VALUE_TYPE(pValue));
-                        cFilenameInit = t.operator CFX_ByteString();
+                        cFilenameInit = t.operator CFX_ByteString();
                 }
-                
+                
                 pValue = JS_GetObjectElement(isolate,pObj,L"cFSInit");
                 {
                         CJS_Value t = CJS_Value(isolate, pValue, GET_VALUE_TYPE(pValue));
                         cFSInit = t.operator CFX_ByteString();
                 }
         }
         else
         {
                 if(params.size() >= 1)
                 {
@@ skipping 182 matching lines @@
                         swDefault = params[2];
                         bPassWord = params[3];
                         swLabel = params[4];
                         break;
                 default:
                         break;
                 }
         }
 
         CJS_Context* pContext = (CJS_Context *)cc;
-        ASSERT(pContext != NULL);
+        ASSERT(pContext != NULL);
 
         CPDFDoc_Environment* pApp = pContext->GetReaderApp();
-        ASSERT(pApp != NULL);
+        ASSERT(pApp != NULL);
         int nLength = 2048;
         char* pBuff = new char[nLength];
         nLength = pApp->JS_appResponse(swQuestion, swTitle, swDefault, swLabel, bPassWord, pBuff, nLength);
         if(nLength<=0)
         {
+                delete[] pBuff;
                 vRet.SetNull();
                 return FALSE;
         }
         else
         {
-                nLength = nLength>2046?2046:nLength;
-    pBuff[nLength] = 0;
-    pBuff[nLength+1] = 0;
-                swResponse = CFX_WideString::FromUTF16LE((unsigned short*)pBuff, nLength);
-                vRet = swResponse;
+                nLength = nLength > sizeof(pBuff) ? sizeof(pBuff) : nLength;
+        vRet = swResponse = CFX_WideString::FromUTF16LE((unsigned short*)pBuff, nLength / 2);
         }
         delete[] pBuff;
 
         return TRUE;
 }
 
 FX_BOOL app::media(OBJ_PROP_PARAMS)
 {
         return FALSE;
 }
 
 FX_BOOL app::execDialog(OBJ_METHOD_PARAMS)
 {
         return TRUE;
 }