> Can you produce an example source code that repeats this
> problem?

Please see the end of this email.

> I assume you've tried this with 7.19.3? (you said "latest" but I'd like to get it confirmed
> what specific version it was you used)

7.19.3

> Well, there's no such requirements enforced by libcurl
> and I've never seen this problem before. Not in my own
> tests and not in any reports from others.

OK, must be something in my implementation then.

> What resolver are you using? What platform do you run this
> on?

I'm running on a Sharp Zaurus : XScale/ARM with OpenPDA, Linux kernel 2.4.18.
My own build of libcurl. I don't know enough about networking to tell you about the resolver so please explain to me if you need that info.

Here is an example; it's taken from my app where I have implemented a curl wrapper in C++ as a QT object. I use a QT timer to call curl_multi_perform every 100 ms. It's basically modified from the example codes on the curl website.

/**
 * @file curlproxyproblem.c
 * @brief Demonstrate problem with proxy
 * @author Lyndon Hill
 * @date 2009.02.23 Incept.
 * @note This is an example, it must be modified before compiling!
 */

#include <curl/curl.h>

/* structs and prototypes */

struct cData
{
  char *data;
  int size;
};

size_t writeData(void *ptr, size_t size, size_t nmemb, void *data);
void CleanUp();

/* globals */

CURL *handle;
CURLM *mhandle;
int status;
struct cData chunk;

/* main */

int main(int argc, char *argv[])
{
  char *url = "http://www.google.com";
  char *proxy = "http://myproxy.org";

  mhandle = curl_multi_init();

  /* Attempt 1: Note: required proxy is missing */
  handle = curl_easy_init();
  curl_easy_setopt(handle, CURLOPT_URL, url);
  curl_easy_setopt(handle, CURLOPT_VERBOSE, 1);
  curl_easy_setopt(handle, CURLOPT_TIMEOUT, 60);
  curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, writeData);
  curl_easy_setopt(handle, CURLOPT_WRITEDATA, (void *)&chunk);
  curl_easy_setopt(handle, CURLOPT_FOLLOWLOCATION, 1);
  curl_easy_setopt(handle, CURLOPT_NOPROGRESS, 0L);

  curl_multi_add_handle(mhandle, handle);
  curl_multi_perform(mhandle, &status);

  while(/* some timer action */)
    curl_multi_perform(mhandle, &status);

  /* Download should fail: could not resolve URL */
 
  CleanUp();

  /* Attempt 2: Set proxy this time!! */
  handle = curl_easy_init();
  curl_easy_setopt(handle, CURLOPT_URL, url);
  curl_easy_setopt(handle, CURLOPT_PROXY, proxy);
  curl_easy_setopt(handle, CURLOPT_VERBOSE, 1);
  curl_easy_setopt(handle, CURLOPT_TIMEOUT, 60);
  curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, writeData);
  curl_easy_setopt(handle, CURLOPT_WRITEDATA, (void *)&chunk);
  curl_easy_setopt(handle, CURLOPT_FOLLOWLOCATION, 1);
  curl_easy_setopt(handle, CURLOPT_NOPROGRESS, 0L);

  curl_multi_add_handle(mhandle, handle);
  curl_multi_perform(mhandle, &status);

  while(/* some timer action */)
    curl_multi_perform(mhandle, &status);
  
  /* Download fails: could not resolve proxy */

  CleanUp();

  curl_multi_cleanup(mhandle);

  curl_global_cleanup();
}

/* Clean up after a transfer */
void CleanUp()
{
  curl_multi_remove_handle(mhandle, handle);
  curl_easy_cleanup(handle);
}

/* Call back function */
size_t writeData(void *ptr, size_t size, size_t nmemb, void *data)
{
  int byteshandled = size*nmemb;
  if(byteshandled == 0) return(byteshandled);

  struct cData *mem = (struct cData *)(data);

  mem->size = byteshandled;

  mem->data = new char [byteshandled]; /* allocate memory */
  if(!mem->data) return(0); /* could not allocate memory */

  memcpy(mem->data, ptr, byteshandled); /* Copy the data stream into the local buffer */

  printf("%s", mem->data);

  delete mem->data;

  return(byteshandled);
}

      
Received on 2009-02-23