Bug: https://github.com/bagder/curl/pull/168

(trynextip)
- Don't try the "other" protocol family unless IPv6 is available. In an
IPv4-only build the other family can only be IPv6 which is unavailable.

This change essentially stops IPv4-only builds from attempting the
"happy eyeballs" secondary parallel connection that is supposed to be
used by the "other" address family.

Prior to this change in IPv4-only builds that secondary parallel
connection attempt could be erroneously used by the same family (IPv4)
which caused a bug where every address after the first for a host could
be tried twice, often in parallel. This change fixes that bug. An
example of the bug is shown below.

Assume MTEST resolves to 3 addresses 127.0.0.2, 127.0.0.3 and 127.0.0.4:

* STATE: INIT => CONNECT handle 0x64f4b0; line 1046 (connection #-5000)
* Rebuilt URL to: http://MTEST/
* Added connection 0. The cache now contains 1 members
* STATE: CONNECT => WAITRESOLVE handle 0x64f4b0; line 1083
(connection #0)
*   Trying 127.0.0.2...
* STATE: WAITRESOLVE => WAITCONNECT handle 0x64f4b0; line 1163
(connection #0)
*   Trying 127.0.0.3...
* connect to 127.0.0.2 port 80 failed: Connection refused
*   Trying 127.0.0.3...
* connect to 127.0.0.3 port 80 failed: Connection refused
*   Trying 127.0.0.4...
* connect to 127.0.0.3 port 80 failed: Connection refused
*   Trying 127.0.0.4...
* connect to 127.0.0.4 port 80 failed: Connection refused
* connect to 127.0.0.4 port 80 failed: Connection refused
* Failed to connect to MTEST port 80: Connection refused
* Closing connection 0
* The cache now contains 0 members
* Expire cleared
curl: (7) Failed to connect to MTEST port 80: Connection refused

The bug was born in commit bagder/curl@2d435c7.

In function Curl_closesocket() in connect.c the call to
Curl_multi_closed() was wrongly omitted if a socket close function
(CURLOPT_CLOSESOCKETFUNCTION) is registered.

That would lead to not removing the socket from the internal hash table
and not calling the multi socket callback appropriately.

Bug: http://curl.haxx.se/bug/view.cgi?id=1493

A signal handler for SIGALRM is installed in Curl_resolv_timeout. It is
configured to interrupt system calls and uses siglongjmp to return into
the function if alarm() goes off.

The signal handler is installed before curl_jmpenv is initialized.
This means that an already installed alarm timer could trigger the
newly installed signal handler, leading to undefined behavior when it
accesses the uninitialized curl_jmpenv.

Even if there is no previously installed alarm available, the code in
Curl_resolv_timeout itself installs an alarm before the environment is
fully set up. If the process is sent into suspend right after that, the
signal handler could be called too early as in previous scenario.

To fix this, the signal handler should only be installed and the alarm
timer only be set after sigsetjmp has been called.

... by using the regular Curl_http_done() method which checks for
that. This makes test 1801 fail consistently with error 56 (which seems
fine) to that test is also updated here.

Reported-by: Ben Darnell
Bug: https://github.com/bagder/curl/issues/166

Required for the test to work after a5d99494.

While the previous string worked, this is the documented format.

Reported-by: Richard Moore

This makes curl pick better (stronger) ciphers by default. The strongest
available ciphers are fine according to the HTTP/2 spec so an OpenSSL
built curl is no longer rejected by string HTTP/2 servers.

Bug: http://curl.haxx.se/bug/view.cgi?id=1487

Required for the tests to work after a5d99494.

...after the method line:

 "Since the Host field-value is critical information for handling a
 request, a user agent SHOULD generate Host as the first header field
 following the request-line." / RFC 7230 section 5.4

Additionally, this will also make libcurl ignore multiple specified
custom Host: headers and only use the first one. Test 1121 has been
updated accordingly

Bug: http://curl.haxx.se/bug/view.cgi?id=1491
Reported-by: Rainer Canavan

Also unified printing to STDERR by creating the helper method "report".

When checking for a connection to re-use, a proxy-using request must
check for and use a proxy connection and not one based on the host
name!

Added test 1421 to verify

Bug: http://curl.haxx.se/bug/view.cgi?id=1492

- Change the continuous integration script to use 'make test-full'
instead of just 'make test' so that the diagnostic log output is
printed to stdout when a test fails.

- Change the continuous integration script to use
'./configure --enable-debug' instead of just './configure' so that the
memory analyzer will work during testing.

Prior to this change Travis used its default C test script:
./configure && make && make test

Instead of priting cipher and MAC algorithms names separately, print the
whole cipher suite string which also includes the key exchange algorithm,
along with the negotiated TLS version.

Bug: https://github.com/bagder/curl/pull/157

The code used some happy eyeballs logic even _after_ CONNECT has been
sent to a proxy, while the happy eyeball phase is already (should be)
over by then.

This is solved by splitting the multi state into two separate states
introducing the new SENDPROTOCONNECT state.

Bug: http://curl.haxx.se/mail/lib-2015-01/0170.html
Reported-by: Peter Laser

Since they already exist and will make comparing easier

malloc() and strdup() calls without checking return codes.

Reported-by: Markus Elfring
Bug: https://github.com/bagder/curl/issues/150

Reported-by: Jonathan Cardoso

In addition to commit 709cf76f, removed the USE_SSLEAY preprocessor
variable from the Visual Studio project files as it isn't required
anymore.

Since 1342a96e, a timeout detected in the multi state machine didn't
necesarily clear everything up, like formpost data.

Bug: https://github.com/bagder/curl/issues/147
Reported-by: Michel Promonet
Patched-by: Michel Promonet

OpenSSL handling was a little broken.

SSLeay was the name of the library that was subsequently turned into
OpenSSL many moons ago (1999). curl does not work with the old SSLeay
library since years. This is now reflected by only using USE_OPENSSL in
code that depends on OpenSSL.

Acked-by: Brad King