reverted the pselect patch => http://curl.haxx.se/mail/lib-2007-03/0100.html

  problems both for HTTP pulling and cloning. Repository size is about 250 Mb,

  so it was a considerable amount of Curl's work.

- Bryan Henderson introduces two things:

  1) the progress callback gets called more frequently (at times)

  2) libcurl *might* call the callback when it receives a signal:

  libcurl calls the progress callback at least once a second, and sometimes

  when the process receives and catches a signal.  Ideally, it would get

  called every time the process receives and catches a signal, but in the

  current implementation, libcurl may fail to recognize a signal during name

  resolution, during the wait for a TCP connection, and during some tiny

  windows other times.

  If you want a signal to interrupt your call to libcurl, install a signal

  handler for it.  Have that signal handler set a flag indicating that the

  signal was received.  Set up a libcurl progress callback that checks that

  flag and, if it is set, returns a nonzero return code.

  Two common kinds of signals you might want to allow to interrupt libcurl

  are: 1) SIGINT, the signal that typically results from a user typing

  control-C; 2) SIGALRM, a signal indicating a timeout.  (libcurl also has

  specific timeout facilities, but SIGALRM can be from a master timeout

  established at a higher layer of your program).

Dan F (9 March 2007)

- Updated the test harness to add a new "crypto" feature check and updated the

  appropriate test case to use it.  For now, this is treated the same as the

 o HTTP Digest header parsing fix for unquoted last word ending with CRLF

 o CURLOPT_PORT, HTTP proxy, re-using connections and non-HTTP protocols

 o CURLOPT_INTERFACE for ipv6

 o the progress callback can get called more frequently

 o libcurl might call the progress callback when it receives a signal

 o use-after-free issue with HTTP transfers with the multi interface

This release includes the following known bugs:

AC_CHECK_FUNCS( strtoll \

                socket \

                select \

                pselect \

                strdup \

                strstr \

                strtok_r \

output. This is only relevant for protocols that actually have headers

preceding the data (like HTTP).

.IP CURLOPT_NOPROGRESS

A non-zero parameter tells the library not to call your progress callback

(see \fICURLOPT_PROGRESSFUNCTION\fP)

and to shut off the built-in progress meter completely.

A non-zero parameter tells the library to shut off the built-in progress meter

completely.

Future versions of libcurl is likely to not have any built-in progress meter

at all.

.IP CURLOPT_PROGRESSFUNCTION

Function pointer that should match the \fIcurl_progress_callback\fP prototype

found in \fI<curl/curl.h>\fP. This function gets called by libcurl instead of

its internal equivalent frequently during operation (roughly

its internal equivalent with a frequent interval during operation (roughly

once per second) no matter if data is being transfered or not.  Unknown/unused

argument values passed to the callback will be set to zero (like if you only

download data, the upload size will remain 0).

The callback serves two purposes: 1) updates you on the progress of

the transfer; 2) gives you an opportunity to abort the transfer.  If

the callback returns a non-zero value, libcurl aborts the transfer and

returns \fICURLE_ABORTED_BY_CALLBACK\fP.

libcurl calls the progress callback at least once a second, and

sometimes when the process receives and catches a signal.  Ideally, it 

would get called every time the process receives and catches a signal,

but in the current implementation, libcurl may fail to recognize a signal

during name resolution, during the wait for a TCP connection, and during

some tiny windows other times.

If you want a signal to interrupt your call to libcurl, install a signal

handler for it.  Have that signal handler set a flag indicating that the

signal was received.  Set up a libcurl progress callback that checks that

flag and, if it is set, returns a nonzero return code.

Two common kinds of signals you might want to allow to interrupt

libcurl are: 1) SIGINT, the signal that typically results from a user

typing control-C; 2) SIGALRM, a signal indicating a timeout.  (libcurl

also has specific timeout facilities, but SIGALRM can be from a master

timeout established at a higher layer of your program).

download data, the upload size will remain 0). Returning a non-zero value from

this callback will cause libcurl to abort the transfer and return

\fICURLE_ABORTED_BY_CALLBACK\fP.

If you transfer data with the multi interface, this function will not be

called during periods of idleness unless you call the appropriate libcurl

function that performs transfers. Usage of the \fBCURLOPT_PROGRESSFUNCTION\fP

callback is not recommended when using the multi interface.

This callback gets called only if you set \fICURLOPT_NOPROGRESS\fP to FALSE.

\fICURLOPT_NOPROGRESS\fP must be set to FALSE to make this function actually

get called.

.IP CURLOPT_PROGRESSDATA

Pass a pointer that will be untouched by libcurl and passed as the first

argument in the progress callback set with \fICURLOPT_PROGRESSFUNCTION\fP.

.IP CURLOPT_HEADERFUNCTION

Function pointer that should match the following prototype: \fIsize_t

function( void *ptr, size_t size, size_t nmemb, void *stream);\fP. This

    ((double)data->progress.uploaded/

     (data->progress.timespent>0?data->progress.timespent:1));

  if(data->progress.lastshow == Curl_tvlong(now))

    return 0; /* never update this more than once a second if the end isn't

                 reached */

  data->progress.lastshow = now.tv_sec;

  /* Let's do the "current speed" thing, which should use the fastest

    return result;

  }

  if(data->progress.lastshow == Curl_tvlong(now))

    return 0; /* never update this more than once a second if the end isn't

                 reached */

  /* Figure out the estimated time of arrival for the upload */

  if((data->progress.flags & PGRS_UL_SIZE_KNOWN) &&

     (data->progress.ulspeed>0) &&