As this function uses return code 0 to mean that there is no timeout, it
needs to check that it doesn't return a time left value that is exactly
zero. It could lead to libcurl doing an extra 1000 ms select() call and
thus not timing out as accurately as it should.

I fell over this bug when working on the bug 3061535 but this fix does
not correct that problem alone, although this is a problem that needs to
be fixed.

Reported by: Rodric Glaser
Bug: http://curl.haxx.se/bug/view.cgi?id=3061535

The timeout is set for the connect phase already at the start of the
request so we should not add a new one, and we MUST not set expire to 0
as that will remove any other potentially existing timeouts.

The code reading chunked encoding attempts to rewind the code if it had
read more data than the chunky parser consumes. The rewinding can fail
and it will then cause an error. This change now makes the rewinding
only happen if pipelining is in use - as that's the only time it really
needs to be done.

Bug: http://curl.haxx.se/mail/lib-2010-08/0297.html
Reported by: Ron Parker

Curl_getconnectinfo() is changed to return a proper curl_socket_t for
the last socket so that it'll work more portably (and cause less
compiler warnings).

Add a timeout check for handles in the state machine so that they will
timeout in all states disregarding what actions that may or may not
happen.

Fixed a bug in socket_action introduced recently when looping over timed
out handles: it wouldn't assign the 'data' variable and thus it wouldn't
properly take care of handles.

In the update_timer function, the code now checks if the timeout has
been removed and then it tells the application. Previously it would
always let the remaining timeout(s) just linger to expire later on.

Curl_expire() set to 0 expires ALL timeouts so it should only be called
if we truly and really want to remove all timeouts for the handle.

Make use of the helper function Curl_timeleft() instead of duplicating
code.

Each easy handle has a list of timeouts, so as soon as the main timeout
for a handle expires, we must make sure to get the next entry from the
list and re-add the handle to the splay tree.

This was attempted previously but was done poorly in my commit
232ad654.

When a new transfer is about to start we now set the proper timeouts to
expire for the multi interface if they are set for the handle. This is a
follow-up bugfix to make sure that easy handles timeout properly when
the times expire and the multi interface is used. This also improves
curl_multi_timeout().

As the VC and RISCOS makefiles don't use the .inc file

The fix for the busyloop really only is a temporary work-around.  It
causes a BLOCKING behavior which is a NO-NO. This function should rather
be split up in a do and a doing piece where the pieces that aren't
possible to send now will be sent in the doing function repeatedly until
the entire request is sent.

HTTP allows that a server sends trailing headers after all the chunks
have been sent WITHOUT signalling their presence in the first response
headers. The "Trailer:" header is only a SHOULD there and as we need to
handle the situation even without that header I made libcurl ignore
Trailer: completely.

Test case 1116 was added to verify this and to make sure we handle more
than one trailer header properly.

Reported by: Patrick McManus
Bug: http://curl.haxx.se/bug/view.cgi?id=3052450

The correctly extracted errno contents were mistakenly overwritten by a newer
value that wasn't the correct error value.

Bug: http://curl.haxx.se/mail/lib-2010-08/0242.html

The script works exactly same as the Perl one except for one thing:
when the text descriptions generated with openssl are included then
the md5 fingerprints are missing; seems openssl has either a bug or
a feature which prints the md5 fingerprint output to stdout instead
of writing them to specified file; this script could here do the same
as what the Perl scripr does (redirect stdout into file) but this
makes the script take up double the time because it needs to launch
cmd.exe 140 times (fo each openssl call). So I think for now we just
ommit the md5 fingerprints, and see if openssl will be fixed.

I fell over this bug report that mentioned that libcurl could wrongly
send more than one complete messages at the end of a transfer. Reading
the code confirmed this, so I've added a new multi state to make it not
happen. The mentioned bug report was made by Brad Jorsch but is (oddly
enough) filed in Debian's bug tracker for the "wmweather+" tool.

Bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=593390

Add a call to Curl_pgrsSetUploadSize in this case valided by a test
case.

Reported by: Никита Дорохин.
Bug: http://curl.haxx.se/mail/lib-2010-04/0173.html

There's an error in http_negotiation.c where a mistake is using only
userpwd even for proxy requests. Ludek provided a patch, but I decided
to write the fix slightly different using his patch as inspiration.

Reported by: Ludek Finstrle
Bug: http://curl.haxx.se/bug/view.cgi?id=3046066

When detecting that the send or recv speed, the multi interface changes
state to TOOFAST and previously there was no timeout set that would
force a recheck but it would rely on the application to somehow call
libcurl anyway. This now sets a timeout for a suitable future time to
check again if the average transfer speed is then below the threshold
again.

Curl_expire() is now expanded to hold a list of timeouts for each easy
handle. Only the closest in time will be the one used as the primary
timeout for the handle and will be used for the splay tree (which sorts
and lists all handles within the multi handle).

When the main timeout has triggered/expired, the next timeout in time
that is kept in the list will be moved to the main timeout position and
used as the key to splay with. This way, all timeouts that are set with
Curl_expire() internally will end up as a proper timeout. Previously any
Curl_expire() that set a _later_ timeout than what was already set was
just silently ignored and thus missed.

Setting Curl_expire() with timeout 0 (zero) will cancel all previously
added timeouts.

Corrects known bug #62.

When we specify the "insert after" entry as NULL, this function now
inserts the new entry first in the list.