Tidy up app::response().

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 1019 matching lines @@
 FX_BOOL app::response(OBJ_METHOD_PARAMS)
 {
         CFX_WideString swQuestion = L"";
         CFX_WideString swLabel = L"";
 #ifndef FOXIT_CHROME_BUILD
         CFX_WideString swTitle = L"Foxit";
 #else
         CFX_WideString swTitle = L"PDF";
 #endif
         CFX_WideString swDefault = L"";
-        CFX_WideString swResponse = L"";
         bool bPassWord = false;
-        
+
         v8::Isolate* isolate = GetIsolate(cc);
-        
-        int iLength = params.size();    
+
+        int iLength = params.size();
         if (iLength > 0 && params[0].GetType() == VT_object)
         {
-                
                 JSObject pObj = (JSObject )params[0];
                 v8::Handle<v8::Value> pValue = JS_GetObjectElement(isolate,pObj,L"cQuestion");
                         swQuestion = CJS_Value(isolate,pValue,GET_VALUE_TYPE(pValue)).operator CFX_WideString();
 
                 pValue = JS_GetObjectElement(isolate,pObj,L"cTitle");
                         swTitle = CJS_Value(isolate,pValue,GET_VALUE_TYPE(pValue)).operator CFX_WideString();
 
                 pValue = JS_GetObjectElement(isolate,pObj,L"cDefault");
                         swDefault = CJS_Value(isolate,pValue,GET_VALUE_TYPE(pValue)).operator CFX_WideString();
 
@@ skipping 35 matching lines @@
                 default:
                         break;
                 }
         }
 
         CJS_Context* pContext = (CJS_Context *)cc;
         ASSERT(pContext != NULL);
 
         CPDFDoc_Environment* pApp = pContext->GetReaderApp();
         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)
+
+        const int kMaxInputBytes = 2048;

[jun_fang, 2014/07/29 18:12:24]

It's suggested to use uppercase like MAX_INPUT_BYPTES to define a const
variable.

+        char* pBuff = new char[kMaxInputBytes + 2];
+        if (!pBuff)
+                  return FALSE;
+
+        memset(pBuff, 0, kMaxInputBytes + 2);
+        int nLengthBytes = pApp->JS_appResponse(swQuestion, swTitle, swDefault, swLabel, bPassWord, pBuff, kMaxInputBytes);
+        if (nLengthBytes <= 0 || nLengthBytes > kMaxInputBytes)

[jun_fang, 2014/07/29 18:03:36]

I saw the comments for the function of app_response.

int (*app_response)(struct _IPDF_JsPlatform* pThis, FPDF_WIDESTRING Question,
FPDF_WIDESTRING Title, FPDF_WIDESTRING Default, FPDF_WIDESTRING cLabel,
FPDF_BOOL bPassword, void* response, int length);

* Return Value:
* Number of bytes the user input text consumes, not including trailing zeros. If
the text exceed 2048 bytes, the exceeded part will be ignored.

According to the comments, we change 2048 bytes to UTF16 rather than returning a
false.

         {
+                vRet.SetNull();
                 delete[] pBuff;
-                vRet.SetNull();
                 return FALSE;
         }
-        else
-        {
-                nLength = nLength > sizeof(pBuff) ? sizeof(pBuff) : nLength;
-        vRet = swResponse = CFX_WideString::FromUTF16LE((unsigned short*)pBuff, nLength / 2);
-        }
+
+        vRet = CFX_WideString::FromUTF16LE((unsigned short*)pBuff, nLengthBytes / 2);
         delete[] pBuff;
-
         return TRUE;
 }
 
 FX_BOOL app::media(OBJ_PROP_PARAMS)
 {
         return FALSE;
 }
 
 FX_BOOL app::execDialog(OBJ_METHOD_PARAMS)
 {
         return TRUE;
 }