It is no longer done blocking in the multi interface

First off the timeout for accepting a server connect back must of course
respect a global timeout. Then the timeleft function is only used by ftp
code so it was moved to ftp.c and made static.

It did a long time ago

"wait_data_conn" was added to the connectionbits in commit c834213a for
handling active FTP connections but as it is purely FTP specific and now
only ever accessed by ftp.c I moved it into the FTP connection struct.

Backpedaled out the funny double-change of state in the multi state
machine by adding a new argument to the do_more() function to signal
completion. This way it can remain in the DO_MORE state properly until
done. Long term, the entire DO_MORE logic should be moved into the FTP
code and be hidden from the multi code as the logic is only used for
FTP.

1- Two new error codes are introduced.

CURLE_FTP_ACCEPT_FAILED to be set whenever ACCEPTing fails because of
FTP server connected.

CURLE_FTP_ACCEPT_TIMEOUT to be set whenever ACCEPTing timeouts.

Neither of these errors are considered fatal and control connection
remains OK because it could just be a firewall blocking server to
connect to the client.

2- One new setopt option was introduced.

CURLOPT_ACCEPTTIMEOUT_MS

It sets the maximum amount of time FTP client is going to wait for a
server to connect. Internal default accept timeout is 60 seconds.

This offers an alternative to the existing Curl_socket_ready() API which
only checks one socket for read and one for write.

When working with the Android Standalone Toolchain the compiler defines
this macro:

  /path/to/arm-linux-androideabi-gcc -E -dM - < /dev/null \
  | grep -i android
  #define __ANDROID__ 1

We really need to check both ANDROID and __ANDROID__ since I've observed
that:

* if you use Android.mk file(s) and the 'ndk-build' script (aka vanilla
way), ANDROID is predefined (see -DANDROID extra C flag),

* if you use the Android Standalone Toolchain, then __ANDROID__ is
predefined as stated by the compiler

As commit ce896875 fixed a timer that accidentally had been moved in
code and then returned a bad timer, the lib500.c code (used in test 500
and some others) now verifies 5 timers against each other to verify that
they have the correct relative values. We cannot compare against
absolute values as the timings will vary a lot.

It makes it easier to introduce debug outputs in this function, and
everything in the function is using the value anyway so it might even be
more efficient.

Regression introduced in 7.23.0 with commit 9dd85bce. The function in
which the PRETRANSFER time stamp was recorded was moved in time causing
it be stored very quickly after the start timestamp. On most systems
shorter than 1 millisecond and thus it wouldn't even show with -w
"%{time_pretransfer}" using the command line tool.

Bug: http://curl.haxx.se/mail/archive-2011-12/0022.html
Reported by: Toni Moreno

Parameters were underquoted, resulting in
warning: AC_LANG_CONFTEST: no AC_LANG_SOURCE call detected in body

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

The CURLM_CALL_MULTI_PERFORM reference is an old leftover I had to
remove.

I also added some blurb to the previously blank "sharing" section.

Allow, at configure time, the production of versioned symbols. The
symbols will look like "CURL_<FLAVOUR>_<VERSION> <SYMBOL>", where
<FLAVOUR> represents the SSL flavour (e.g. OPENSSL, GNUTLS, NSS, ...),
<VERSION> is the major SONAME version and <SYMBOL> is the actual symbol
name. If no SSL library is enabled the symbols will be just
"CURL_<VERSION> <SYMBOL>".

This gets the appconnect time right for ssl backends, which don't
support non-blocking connects.

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>

One new feature, one bug fix. Introduced references in this file for
mentioned issues after this discussion:
http://curl.haxx.se/mail/lib-2011-12/0187.html

The plan is to let the references get moved over to the changes.html
file at release-time

Document the possibility of providing multiple values using the ":"
separator, and the fact that the default value will be ignored if the
option is used.

Test case 1315 was added to verify this functionality. When passing in
multiple files to a single -F, the parser would get all confused if one
of the specified files had a custom type= assigned.

Reported by: Colin Hogben

test 1315 checks correct behaviour when uploading multiple files.
Buggy behaviour has been seen where only two attachments are sent.

Two variable names were wrong in the documentation.

The default content-type for file uploads is application/octet-stream,
not text/plain as stated in the MANUAL.

Avoid 'interface' literal that some MinGW versions define as a macro

Do not try to resolve interfaces names via DNS by recognizing interface
names in a few ways.  If the interface option argument has a prefix of
"if!" then treat the argument as only an interface.  Similarly, if the
interface argument is the name of an interface (even if it does not have
an IP address assigned), treat it as an interface name.  Finally, if the
interface argument is prefixed by "host!" treat it as a hostname that
must be resolved by /etc/hosts or DNS.

These changes allow a client using the multi interfaces to avoid
blocking on name resolution if the interface loses its IP address or
disappears.

5 more bugfixes, 5 more contributors

Fixed the connection reuse detection in ConnectionExists() when
comparing a new connection that is non-SSL based against that of a SSL
based connection that has become so by being upgraded via TLS.

This is a regression since who knows when. When spotting that a HTTP
proxy is used we must not uncondititionally enable the HTTP protocol
since if we do tunneling through the proxy we're still using the target
protocol.

Reported by: Naveen Chandran

As a follow-up from commit d5b5f64b, clear the sock_accepted status
when such a socket is closed to avoid a re-used connection to retain the
state wrongly.

Bug: http://curl.haxx.se/mail/lib-2011-12/0079.html