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Decompression problems

From: Jonathan Wallace <>
Date: Fri, 17 Apr 2009 10:40:08 -0400

I hope someone can help me figure out what's going wrong with this
thing, I've been fighting with it for months. I have a bit of software
that is supposed to pull in compressed data from a server. The server
uses zlib to do compression, the exact same version that I have (and
I've tried multiple dlls, they all don't work, so that leads me to
believe it's a libcurl problem. I must be doing something wrong, but so
far no one has been able to figure out what.

I've used Fiddler to see what's coming back, it is correctly compressed
data (deflate,) so it's not a communication problem.

The error buffer has this in it: Error while processing content
unencoding: incorrect header check

Here is my source code:

string httpLoader::DownloadFile(string & xurl, bool login){
      This method requires that the server address be including in the
xurl, if you are
      using the server which has been connected to in the login process,
use DownloadFileMyServer
    wxString temp = wxString::FromAscii(xurl.c_str());
    temp.Replace(_T("\\\\\\\\"), _T("\\\\"), true);
    xurl = string(temp.mb_str());
    //initialize the http component
    CURLcode result;
    if (curl){
        char errorBuffer[CURL_ERROR_SIZE];
        string buffer;
        curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errorBuffer);
        curl_easy_setopt(curl, CURLOPT_POST, 0);
        curl_easy_setopt(curl, CURLOPT_URL, xurl.c_str());
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writer);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &buffer);

        result = curl_easy_perform(curl);

        if(result == CURLE_OK){
             return buffer;
        } else {
             Debug::Log("result != CURLE_OK");

    } else {
        Debug::Log("Unable to create CURL Instance");
    return "";

void httpLoader::SetOptions(bool login){
    if (XRequestID.empty()){ //create the XRequestID
       wxDateTime now = wxDateTime::Now();
       wxString nowtime = now.Format(_T("%m%d%y_%Hh%M"));
       XRequestID = "x-requestid: LiveRuntime" + string(nowtime.mb_str());

    if (DebugMode & LR_DEBUG_FIDDLER) curl_easy_setopt(curl,
    if (DebugMode & LR_DEBUG_HTTPLOG){
            curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION, my_trace);
            curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);

    struct curl_slist *headers = NULL;
    headers = curl_slist_append(headers, "Accept: */*");
    if (DebugMode & LR_DEBUG_COMPRESSION){
        headers = curl_slist_append(headers, "Accept-Encoding: deflate");
        curl_easy_setopt(curl, CURLOPT_ENCODING, "deflate");
    if (!LOSID.empty()){
       string s = "LOSID=" + LOSID;
       headers = curl_slist_append(headers, s.c_str());
    headers = curl_slist_append(headers, "Accept-Language: en-us");
    headers = curl_slist_append(headers, "User-Agent: LiveRuntime");
    headers = curl_slist_append(headers, XRequestID.c_str());
    headers = curl_slist_append(headers, "Connection: Keep-Alive");
    headers = curl_slist_append(headers, "Content-Type:");
    headers = curl_slist_append(headers, "Authorization:");
    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
Received on 2009-04-17