google apps script ==> UrlFetchApp, method GET and cookie - cookies

Question

I use the UrlFetchApp to send the user and pwd (method POST). After get the cookie, and use in other request (method GET). But this new request not working, I think that this cookie not has correct use in this new request. Can anyone help me?
var opt ={
"method":"post",
"User-Agent" : "Mozilla/5.0",
"Accept" : "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
"Accept-Language" : "en-US,en;q=0.5",
"payload": this.payload.toString(),
"followRedirects" : false
};
var response = UrlFetchApp.fetch("https://edas.info/addTopic.php?c=19349",opt);
var resp1=response.getContentText();
Logger.log(resp1);
response.getResponseCode();
var headers = response.getAllHeaders();
var cookies = headers['Set-Cookie'];
for (var i = 0; i < cookies.length; i++) {
cookies[i] = cookies[i].split( ';' )[0];
};
opt = {
"method" : "get",
"User-Agent" : "Mozilla/5.0",
"Accept" : "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
"Accept-Language" : "en-US,en;q=0.5",
"headers": {
"Cookie": cookies.join(';')
},
"followRedirects" : false
};
response = UrlFetchApp.fetch("https://edas.info/addTopic.php?c=19349", opt);
var resp1=response.getContentText();
Logger.log(resp1);

Answer 1

First off, thanks you for the snippet of code, this got me started with processing cookies in such script. I encountered an issue that was possibly your problem. Sometimes a Web page returns an array of cookies, and then your code works fine. Sometimes it returns a single string (instead of an array of one string). So I had to disambiguate with a test like:
if ( (cookies != null) && (cookies[0].length == 1) ) {
cookies = new Array(1);
cookies[0] = headers['Set-Cookie'];
}

Answer 2

I cannot give you specific help for your problem, one pointer though, as found here
Cookie handling in Google Apps Script - How to send cookies in header?
As https://stackoverflow.com/users/1435550/thierry-chevillard put it:
Be aware also that GAS uses Google IPs. It can happen that two consecutive fetch use different IPs. The server your are connecting to may be session-IP dependant.
Does your code run on the local development server and only fail once deployed to App Engine?
Or does it fail locally, as well?