Tidy up app::response().

fpdfsdk/src/javascript/app.cpp

Index: fpdfsdk/src/javascript/app.cpp
diff --git a/fpdfsdk/src/javascript/app.cpp b/fpdfsdk/src/javascript/app.cpp
index 3b92a992d9d0be2b46db2266d0e51847b0a34fdd..92e08ff48fba0eece261177cafbf5c0bb77b34c3 100644
--- a/fpdfsdk/src/javascript/app.cpp
+++ b/fpdfsdk/src/javascript/app.cpp
@@ -1037,15 +1037,13 @@ FX_BOOL app::response(OBJ_METHOD_PARAMS)
 	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();
@@ -1101,22 +1099,23 @@ FX_BOOL app::response(OBJ_METHOD_PARAMS)
 
 	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.

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