Bug: https://curl.haxx.se/mail/lib-2017-09/0031.html

If the INTERLEAVEFUNCTION is defined, then use that plus the
INTERLEAVEDATA information when writing RTP. Otherwise, use
WRITEFUNCTION and WRITEDATA.

Fixes #1880
Closes #1884

Closes https://github.com/curl/curl/pull/1687

The stub implementation is pre-loaded using LD_PRELOAD
and emulates common gssapi uses (only builds if curl is
initially built with gssapi support).

The initial tests are currently disabled for debug builds
as LD_PRELOAD is not used then.

Ref: https://github.com/curl/curl/pull/1687

Closes #1889

... as when a proxy connection is being re-used, it can still get a
different remote port.

Fixes #1887
Reported-by: Oli Kingshott

Closes #1878

... as the code style mandates.

... not only HTTP uses this now.

Closes #1875

CA path processing was implemented when mbedtls.c was added to libcurl
in fe7590f7, but it was never enabled.

Bug: https://github.com/curl/curl/issues/1877


Reported-by:  <SBKarr@users.noreply.github.com>

If the default write callback is used and no destination has been set, a
NULL pointer would be passed to fwrite()'s 4th argument.

OSS-fuzz bug https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=3327
(not publicly open yet)

Detected by OSS-fuzz
Closes #1874

... to avoid a clang bug

Add support for HEADER, COOKIE, RANGE, CUSTOMREQUEST, MAIL_RECIPIENT,
MAIL_FROM and uploading data.

The tests for object file/executable file extensions are presumably only
done for the first of these macros in the configure file.

Bug: https://github.com/curl/curl/pull/1851#issuecomment-327597515
Reported-by: Marcel Raad
Closes #1873

Now that the form API is deprecated and not used anymore in curl tool,
a lot of its features left untested. Test 650 attempts to check all these
features not tested elsewhere.

- Prepend srcdir include path instead of append.

Prior to this change it was possible that during the check for the size
of curl_off_t the include path of a user's already installed curl could
come before the include path of the to-be-built curl, resulting in the
system.h of the former being incorrectly included for that check.

Closes https://github.com/curl/curl/pull/1870

It has already been fixed in 6140dfcf

`conn->connect_state` is NULL when doing a regular non-CONNECT request
over the proxy and should therefor be considered complete at once.

Fixes #1853
Closes #1862
Reported-by: Lawrence Wagerfield

Another mistake in my manual fixups of the largely mechanical
search-and-replace ("connssl->" -> "BACKEND->"), just like the previous
commit concerning HTTPS proxies (and hence not caught during my
earlier testing).

Fixes #1855
Closes #1871

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

In d65e6cc4 (vtls: prepare the SSL backends for encapsulated private
data, 2017-06-21), this developer prepared for a separation of the
private data of the SSL backends from the general connection data.

This conversion was partially automated (search-and-replace) and
partially manual (e.g. proxy_ssl's backend data).

Sadly, there was a crucial error in the manual part, where the wrong
handle was used: rather than connecting ssl[sockindex]' BIO to the
proxy_ssl[sockindex]', we reconnected proxy_ssl[sockindex]. The reason
was an incorrect location to paste "BACKEND->"... d'oh.

Reported by Jay Satiro in https://github.com/curl/curl/issues/1855

.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Ever since 70f1db32

 (vtls: encapsulate SSL backend-specific data,
2017-07-28), the code handling HTTPS proxies was broken because the
pointer to the SSL backend data was not swapped between
conn->ssl[sockindex] and conn->proxy_ssl[sockindex] as intended, but
instead set to NULL (causing segmentation faults).

[jes: provided the commit message, tested and verified the patch]

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

... instead of the prefix-less version since WolfSSL 3.12 now uses an
enum with that name that causes build failures for us.

Fixes #1865
Closes #1867
Reported-by: Gisle Vanem

Closes #1868

- The part kind MIMEKIND_FILE and associated code are suppressed.
- Seek data origin offset not used anymore: suppressed.
- MIMEKIND_NAMEDFILE renamed MIMEKIND_FILE; associated fields/functions
  renamed accordingly.
- Curl_getformdata() processes stdin via a callback.

Back in 2008, (and commit 3f3d6ebe) we changed the logic in how we
determine the native type for `curl_off_t`. To really make sure we
didn't break ABI without bumping SONAME, we introduced logic that
attempted to detect that it would use a different size and thus not be
compatible. We also provided a manual switch that allowed users to tell
configure to bump SONAME by force.

Today, we know of no one who ever got a SONAME bump auto-detected and we
don't know of anyone who's using the manual bump feature. The auto-
detection is also no longer working since we introduced defining
curl_off_t in system.h (7.55.0).

Finally, this bumping logic is not present in the cmake build.

Closes #1861

- Do a case-insensitive comparison of CURL_SSL_BACKEND env as well.

- Change Curl_strcasecompare calls to strcasecompare
  (maps to the former but shorter).

Follow-up to c290b8fb.

Bug: https://github.com/curl/curl/commit/c290b8f#commitcomment-24094313

Co-authored-by: Jay Satiro