Lots of work and analysis by "xbx___" in bug #1431750

                                  Changelog

Daniel (22 February 2006)

- Lots of work and analysis by "xbx___" in bug #1431750

  (http://curl.haxx.se/bug/view.cgi?id=1431750) helped me identify and fix two

  different but related bugs:

  1) Removing an easy handle from a multi handle before the transfer is done

     could leave a connection in the connection cache for that handle that is

     in a state that isn't suitable for re-use. A subsequent re-use could then

     read from a NULL pointer and segfault.

  2) When an easy handle was removed from the multi handle, there could be an

     outstanding c-ares DNS name resolve request. When the response arrived,

     it caused havoc since the connection struct it "belonged" to could've

     been freed already.

  Now Curl_done() is called when an easy handle is removed from a multi handle

  pre-maturely (that is, before the transfer was complteted). Curl_done() also

  makes sure to cancel all (if any) outstanding c-ares requests.

Daniel (21 February 2006)

- Peter Su added support for SOCKS4 proxies. Enable this by setting the proxy

  type to the already provided type CURLPROXY_SOCKS4.

This release includes the following bugfixes:

 o two bugs concerning using curl_multi_remove_handle() before the transfer

   was complete

 o multi-pass authentication and compressed content

 o minor format string mistake in the GSS/Negotiate code

 o cached DNS entries could remain in the cache too long

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) 1998 - 2005, Daniel Stenberg, <daniel@haxx.se>, et al.

 * Copyright (C) 1998 - 2006, Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms

#define CURL_ASYNC_SUCCESS ARES_SUCCESS

#else

#define CURL_ASYNC_SUCCESS CURLE_OK

#define ares_cancel(x)

#endif

/*

  int msg_num; /* number of messages left in 'msg' to return */

};

#define CURL_MULTI_HANDLE 0x000bab1e

#define GOOD_MULTI_HANDLE(x) ((x)&&(((struct Curl_multi *)x)->type == CURL_MULTI_HANDLE))

#define GOOD_MULTI_HANDLE(x) \

  ((x)&&(((struct Curl_multi *)x)->type == CURL_MULTI_HANDLE))

#define GOOD_EASY_HANDLE(x) (x)

/* This is the struct known as CURLM on the outside */

    Curl_easy_addmulti(easy->easy_handle, NULL); /* clear the association

                                                    to this multi handle */

    Curl_done(&easy->easy_conn, easy->result);

    /* make the previous node point to our next */

    if(easy->prev)

      easy->prev->next = easy->next;

  /* Continue connectdata initialization here.

   *

   * Inherit the proper values from the urldata struct AFTER we have arranged

   * the persistent conncetion stuff */

   * the persistent connection stuff */

  conn->fread = data->set.fread;

  conn->fread_in = data->set.in;

  Curl_pgrsDone(conn); /* done with the operation */

  /* for ares-using, make sure all possible outstanding requests are properly

     cancelled before we proceed */

  ares_cancel(data->state.areschannel);

  /* if data->set.reuse_forbid is TRUE, it means the libcurl client has

     forced us to close this no matter what we think.