...as otherwise the TLS libs will skip the CN/SAN check and just allow
connection to any server. curl previously skipped this function when SNI
wasn't used or when connecting to an IP address specified host.

CVE-2016-3739

Bug: https://curl.haxx.se/docs/adv_20160518A.html
Reported-by: Moti Avrahami

Closes #811

Closes #762

CID 1361815: Explicit null dereferenced (FORWARD_NULL)

CID 1361811: Explicit null dereferenced (FORWARD_NULL)

CID 1024412: Memory - illegal accesses (OVERRUN). Claimed to happen when
we run over 'workend' but the condition says <= workend and for all I
can see it should be safe. Compensating for the warning by adding a byte
margin in the buffer.

Also, removed the extra brace level indentation in the code and made it
so that 'workend' is only assigned once within the function.

- Return value type must match function type.

s/CURLM_OUT_OF_MEMORY/CURLE_OUT_OF_MEMORY/

Caught by Travis CI

The proper FTP wildcard init is now more properly done in Curl_pretransfer()
and the corresponding cleanup in Curl_close().

The previous place of init/cleanup code made the internal pointer to be NULL
when this feature was used with the multi_socket() API, as it was made within
the curl_multi_perform() function.

Reported-by: Jonathan Cardoso Machado
Fixes #800

Because the old OpenSSL link now redirects to their master documentation
(currently 1.1.0), which does not document the required actions for
OpenSSL <= 1.0.2.

Added 8 bug fixes and 5 more contrbutors

Prior to this change a width arg could be erroneously output, and also
width and precision args could not be used together without crashing.

"%0*d%s", 2, 9, "foo"

Before: "092"
After: "09foo"

"%*.*s", 5, 2, "foo"

Before: crash
After: "   fo"

Test 557 is updated to verify this and more

Follow-up commit to 58231795

Closes #648

The new way of disabling certificate verification doesn't work on
Mountain Lion (OS X 10.8) so we need to use the old way in that version
too. I've tested this solution on versions 10.7.5, 10.8, 10.9, 10.10.2
and 10.11.

Closes #802

curl's representation of HTTP/2 responses involves transforming the
response to a format that is similar to HTTP/1.1. Prior to this change,
curl would do this by separating header names and values with only a
colon, without introducing a space after the colon.

While this is technically a valid way to represent a HTTP/1.1 header
block, it is much more common to see a space following the colon. This
change introduces that space, to ensure that incautious tools are safely
able to parse the header block.

This also ensures that the difference between the HTTP/1.1 and HTTP/2
response layout is as minimal as possible.

Bug: https://github.com/curl/curl/issues/797

Closes #798
Fixes #797

... introduced in curl-7_48_0-293-g2968c83:

Error: COMPILER_WARNING:
lib/vtls/openssl.c: scope_hint: In function ‘Curl_ossl_check_cxn’
lib/vtls/openssl.c:767:15: warning: conversion to ‘int’ from ‘ssize_t’
may alter its value [-Wconversion]

- In the case of recv error, limit returning 'connection still in place'
to EINPROGRESS, EAGAIN and EWOULDBLOCK.

This is an improvement on the parent commit which changed the openssl
connection check to use recv MSG_PEEK instead of SSL_peek.

Ref: https://github.com/curl/curl/commit/856baf5#comments

Calling SSL_peek can cause bytes to be read from the raw socket which in
turn can upset the select machinery that determines whether there's data
available on the socket.

Since Curl_ossl_check_cxn only tries to determine whether the socket is
alive and doesn't actually need to see the bytes SSL_peek seems like
the wrong function to call.

We're able to occasionally reproduce a connect timeout due to this
bug. What happens is that Curl doesn't know to call SSL_connect again
after the peek happens since data is buffered in the SSL buffer and thus
select won't fire for this socket.

Closes #795

Only protocols that actually have a protocol registered for ALPN and NPN
should try to get that negotiated in the TLS handshake. That is only
HTTPS (well, http/1.1 and http/2) right now. Previously ALPN and NPN
would wrongly be used in all handshakes if libcurl was built with it
enabled.

Reported-by: Jay Satiro

Fixes #789

Sometimes, in systems with both ipv4 and ipv6 addresses but where the
network doesn't support ipv6, Curl_is_connected returns an error
(intermittently) even if the ipv4 socket connects successfully.

This happens because there's a for-loop that iterates on the sockets but
the error variable is not resetted when the ipv4 is checked and is ok.

This patch fixes this problem by setting error to 0 when checking the
second socket and not having a result yet.

Fixes #794

Reported-by: Oleg Pudeyev and fuchaoqun

Fixes #648

Reported-by: rcanavan
Assisted-by: Isaac Boukris
Closes #785

Closes #727

Mention possible content-length mismatch with sum of bytes reported
by write callbacks when auto decoding is enabled.

See #785