Closes https://github.com/curl/curl/pull/3670

.. and for Windows also call WSACleanup since we call WSAStartup.

The example is to demonstrate handling the socket independently of
libcurl. In this case libcurl is not responsible for creating, opening
or closing the socket, it is handled by the application (our example).

Fixes https://github.com/curl/curl/pull/3663

This code was once used for the non multi-interface using code path, but
ever since easy_perform was turned into a wrapper around the multi
interface, this code path never runs.

Closes #3666

- Inherit SSL options for the doh handle but not SSL client certs,
  SSL ALPN/NPN, SSL engine, SSL version, SSL issuer cert,
  SSL pinned public key, SSL ciphers, SSL id cache setting,
  SSL kerberos or SSL gss-api settings.

- Fix inheritance of verbose setting.

- Inherit NOSIGNAL.

There is no way for the user to set options for the doh (DNS-over-HTTPS)
handles and instead we inherit some options from the user's easy handle.

My thinking for the SSL options not inherited is they are most likely
not intended by the user for the DOH transfer. I did inherit insecure
because I think that should still be in control of the user.

Prior to this change doh did not work for me because CAINFO was not
inherited. Also verbose was set always which AFAICT was a bug (#3660).

Fixes https://github.com/curl/curl/issues/3660
Closes https://github.com/curl/curl/pull/3661

Reproduced bug #3649
Closes #3659

This reverts commit 3773de37.

Regression shipped in 7.64.0
Fixes #3649

To not "collide" or use up the regular curl_ name space. Also makes them
easier to detect in helper scripts.

Closes #3656

Clarify the language and simplify.

Reported-by: Daniel Lublin
Closes #3658

Closes #3145

Both seem to be false positives but we don't like warnings.

Closes #3646

Since it can't be NULL and it makes Coverity believe we lack proper NULL
checks. Verified by test 659, landed in commit 15401fa8.

Pointed out by Coverity CID 1442746.

Assisted-by: Dan Fandrich
Fixes #3617
Closes #3642

That's the only public curl header we should encourage use of.

Reviewed-by: Marcel Raad
Closes #3645

If the state machine isn't complete, didn't fail and it didn't return
due to blocking it can just as well loop again.

This addresses the problem with SFTP directory listings where we would
otherwise return back to the parent and as the multi state machine
doesn't have any code for using CURLM_CALL_MULTI_PERFORM for as long the
doing phase isn't complete, it would return out when in reality there
was more data to deal with.

Fixes #3506
Closes #3644

- Change closure handle to receive verbose setting from the easy handle
  most recently added via curl_multi_add_handle.

The closure handle is a special easy handle used for closing cached
connections. It receives limited settings from the easy handle most
recently added to the multi handle. Prior to this change that did not
include verbose which was a problem because on connection shutdown
verbose mode was not acknowledged.

Ref: https://github.com/curl/curl/pull/3598

Co-authored-by: Daniel Stenberg

Closes https://github.com/curl/curl/pull/3618

Test 659 verifies

Also fixed the test 658 name

Closes #3641

Pointed out by Coverity, CID 1442956.

Closes #3640

Closes #3498

Closes #3637

This is the renamed script formerly known as zsh.pl

Closes #3545

It has been deprecated by GnuTLS since a year ago and now causes build
warnings.

Ref: https://gitlab.com/gnutls/gnutls/commit/b0041897d2846737f5fb0f
Docs: https://www.gnutls.org/manual/html_node/Compatibility-API.html

Closes #3636

.. since system_win32 is a more appropriate location for the functions
and to extern the globals.

Ref: https://github.com/curl/curl/commit/ca597ad#r32446578
Reported-by: Gisle Vanem

Closes https://github.com/curl/curl/pull/3625

Reported-by: Sara Golemon

Fixes #3592
Closes #3634

The main change here is the timer value that was wrong, it was given in
usecs (ms * 1000), while the itimerspec struct wants nsecs (ms * 1000 *
1000). This resulted in the callback being invoked WAY TOO OFTEN.

As a quick check you can run this command before and after applying this
commit:

    # shell 1
    ./ephiperfifo 2>&1 | tee ephiperfifo.log
    # shell 2
    echo http://hacking.elboulangero.com

 > hiper.fifo

Then just compare the size of the logs files.

Closes #3633
Fixes #3632
Signed-off-by: Arnaud Rebillout <arnaud.rebillout@collabora.com>

- no need to have them protocol specific

- no need to set pointers to them with the Curl_setup_transfer() call

- make Curl_setup_transfer() operate on a transfer pointer, not
  connection

- switch some counters from long to the more proper curl_off_t type

Closes #3627

 - use better variable names to explain their purposes
 - convert logic to curl_multi_wait()

When a transfer is done, the resolver thread will be brought down. That
could accidentally generate an error message in the error buffer even
though this is not an error situationand the transfer would still return
OK.  An application that still reads the error buffer could find a
"Could not resolve host: [host name]" message there and get confused.

Reported-by: Michael Schmid
Fixes #3629
Closes #3630

clarify redir - "in absurdum" doesn't seem to make sense in this context

Closes #3631

in the same sftp_done function in both SSH backends. Simplify them
somewhat.

Pointed out by Codacy.

Closes #3628

Introduced in 8b6314cc, but not used anymore in current code. Unclear
since when.

Closes #3626

Without it set, we would unwillingly triger the "HTTP error before end
of send, stop sending" condition even if the entire POST body had been
sent (since it wouldn't know the expected size) which would
unnecessarily log that message and close the connection when it didn't
have to.

Reported-by: Matt McClure
Bug: https://curl.haxx.se/mail/archive-2019-02/0023.html
Closes #3624