singleipconnect() did not return the open socket descriptor on some
errors, thereby sometimes causing a socket leak. This patch ensures
the socket is always returned.

Even though this is only a formality (since not many people build on
Mavericks while targeting Leopard), since we still support Leopard
at the earliest, we might as well be pedantic.

It turns out that some of the constants necessary to make this feature
work are missing from Snow Leopard's Security framework even though
they are defined in the headers.

Bug: http://curl.haxx.se/mail/lib-2013-11/0076.html
Reported by: myriachan

Rather than set the authentication options as part of the login details
specified in the URL, or via the older CURLOPT_USERPWD option, added a
new libcurl option to allow the login options to be set separately.

This patch fixes and issue introduced in commit 7d7df831, if the
tunnel state was TUNNEL_CONNECT, waitconnect_getsock() would return a
bitmask indicating a readable socket but never stored the socket in the
return array.

The temporary sockets used for Happy Eyeballs were not closed properly,
if curl exited prematurely, which this patch fixes.

The reason for this loop's existence was removed in commit
02fbc26d.

Our own printf() replacement clearly can't properly handle %.*s with a
string that isn't zero terminated. Instead of fixing the printf code or
even figuring out what the proper posix behavior is, I reverted this
piece of the code back to the previous version where it does malloc +
memcpy instead.

Regression added in e839446c, released in curl 7.32.0.

Reported-by: Felix Yan
Bug: http://curl.haxx.se/bug/view.cgi?id=1295

This patch adds a 200ms delay between the first and second address
family socket connection attempts.

It also iterates over IP addresses in the order returned by the
system, meaning most dual-stack systems will try IPv6 first.

Additionally, it refactors the connect code, removing most code that
handled synchronous connects. Since all sockets are now non-blocking,
the logic can be made simpler.

nss.c:702: warning: pointer targets in passing argument 3 of
'Curl_extract_certinfo' differ in signedness

nss.c:702: warning: pointer targets in passing argument 4 of
'Curl_extract_certinfo' differ in signedness

Made sure the cast was correctly "unsigned char *" to "char *" and not
"unsigned char *" to "unsigned char *".

nss.c:700: warning: pointer targets in passing argument 3 of
'Curl_extract_certinfo' differ in signedness

nss.c:700: warning: pointer targets in passing argument 4 of
'Curl_extract_certinfo' differ in signedness

No need for a rhs condition on a bitwise compare.

warning: implicit declaration of function 'Curl_extract_certinfo'

warning: declaration of 'chsize' shadows a global declaration

curl_sasl.c:294: warning: dereferencing type-punned pointer will break
strict-aliasing rules

getpart.c:201: warning: dereferencing type-punned pointer will break
strict-aliasing rules

Introduced in commit 7d7df831 curl would loop displaying "Whut?"
if it was trying to connect to an address and port that didn't have
anything listening on it.

Renamed copy_header_value() to Curl_copy_header_value() as this
function is now non static.

Simplified proxy flag in Curl_http_input_auth() when calling
sub-functions.

Removed unnecessary white space removal when using negotiate as it had
been missed in commit cdccb422.

...following recent changes to Curl_base64_decode() rather than trying
to parse a header line for the authentication mechanisms which is CRLF
terminated and inline zero terminate it.

...following recent changes to Curl_base64_decode() rather than trying
to parse a header line for the authentication mechanisms which is CRLF
terminated and inline zero terminate it.

The code rejected 0 as a valid timeout while in fact the function could
indeed legitimately return that and it should be respected.

Reported-by: Bjorn Stenberg

and updated copyright year

A base64 string should be a multiple of 4 characters in length, not
contain any more than 2 padding characters and only contain padding
characters at the end of string. For example: Y3VybA==

Strings such as the following are considered invalid:

Y=   - Invalid length
Y==  - Invalid length
Y=== - More than two padding characters
Y=x= - Padding character contained within string

This patch fixes a bug in Happy Eyeballs where curl would wait for a
connect response from socket1 before checking socket2.

Also, it updates error messages for failed connections, showing the ip
addresses that failed rather than just the host name repeatedly.

Bug: http://curl.haxx.se/mail/lib-2013-10/0236.html
Reported-by: Paul Marks

This patch invokes two socket connect()s nearly simultaneously, and
the socket that is first connected "wins" and is subsequently used for
the connection. The other is terminated.

There is a very slight IPv4 preference, in that if both sockets connect
simultaneously IPv4 is checked first and thus will win.