Follow-up to 1b76c389. The VTLS backends that close down the TLS
layer for a connection still needs a Curl_easy handle for the session_id
cache etc.

Fixes #2764
Closes #2771

Set mode="text" when line endings depend on the system representation.

Closes https://github.com/curl/curl/pull/2772

By default, the MSYS2 bash converts all backslashes to forward slashes
in URLs. Disable this with MSYS2_ARG_CONV_EXCL for the test to pass.

Ref https://github.com/msys2/msys2/wiki/Porting#filesystem-namespaces

- separate easy handle from connections better
- added asserts on a number of places
- added sanity check of pipelines for debug builds

Closes #2751

... the protocol is doing read/write a lot, so it needs to write often
even when downloading. A more proper fix could check for eactly when it
wants to write and only ask for it then.

Without this fix, an SMB download could easily get stuck when the event-driven
API was used.

Closes #2768

By default, the MSYS2 bash interprets http:/%HOSTIP:%HTTPPORT/want/1143
as a POSIX file list and converts it to a Windows file list.
Disable this with MSYS2_ARG_CONV_EXCL for the test to pass.

Ref https://github.com/msys2/msys2/wiki/Porting#filesystem-namespaces
Closes https://github.com/curl/curl/pull/2765

... and work toward 7.61.1

Closes #2727
Reviewed-by: Sergei Nikulov

... the "unbold" sequence doesn't work on the mac Terminal.

Reported-by: Zero King
Fixes #2736
Closes #2738

curl configured with --enable-debug --disable-file currently complains
on test1422:
Info: Protocol "file" not supported or disabled in libcurl

Make test1422 dependend on enabled FILE protocol to fix this.

Fixes https://github.com/curl/curl/issues/2741
Closes https://github.com/curl/curl/pull/2742

Some servers issue raw deflate data that may be followed by an undocumented
trailer. This commit makes curl tolerate such a trailer of up to 4 bytes
before considering the data is in error.

Reported-by: clbr on github
Fixes #2719

Detected by OSS-Fuzz
Bug: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=9369
Closes #2740

The definition of CALG_TLS1PRF has been fixed in the 5.1 branch:
https://osdn.net/projects/mingw/scm/git/mingw-org-wsl/commits/73aedcc0f2e6ba370de0d86ab878ad76a0dda7b5

+ The hackerone bounty and its process

- We don't and can't handle pre-notification

It was previously erroneously skipped in some situations.

libtest/libntlmconnect.c wrongly depended on wrong behavior (that it
would get a zero timeout) when no handles are "running" in a multi
handle. That behavior is no longer present with this fix. Now libcurl
will always return a -1 timeout when all handles are completed.

Closes #2733

On multiplexed connections, transfers can be removed from anywhere not
just at the head as for pipelines.

... as the usage needs to be counted.

Commit 38203f15 changed engine detection to be version-based,
with a baseline of openssl 1.0.1. This does in fact break builds
with openssl 1.0.0, which has engine support - the configure script
detects that ENGINE_cleanup() is available - but <openssl/engine.h>
doesn't get included to declare it.

According to upstream documentation, engine support was added to
mainstream openssl builds as of version 0.9.7:
https://github.com/openssl/openssl/blob/master/README.ENGINE

This commit drops the version test down to 1.0.0 as version 1.0.0d
is the oldest version I have to test with.

Closes #2732

Original MinGW's w32api has a sytax error in its definition of
CALG_TLS1PRF [0]. Don't use original MinGW w32api's CALG_TLS1PRF
until this bug [1] is fixed.

[0] https://osdn.net/projects/mingw/scm/git/mingw-org-wsl/blobs/d1d4a17e51a2b78e252ef0147d483267d56c90cc/w32api/include/wincrypt.h
[1] https://osdn.net/projects/mingw/ticket/38391

Fixes https://github.com/curl/curl/pull/2721#issuecomment-403636043
Closes https://github.com/curl/curl/pull/2728

Apparently the C => HTML converter on the web site doesn't quite like it
otherwise.

Reported-by: Jeroen Ooms

Closes #2724

... and not the other way around, which this previously said.

Reported-by: Vasiliy Faronov
Fixes #2723
Closes #2726

Reviewed-by: Jakub Zakrzewski
Closes #2715

Follow-up to 82ce4162.

Ref: https://github.com/curl/curl/commit/8272ec5#commitcomment-29646818

MinGW warns:
/lib/vtls/schannel.c:219:64: warning: signed and unsigned type in
conditional expression [-Wsign-compare]

Fix this by casting the ptrdiff_t to size_t as we know it's positive.

Closes https://github.com/curl/curl/pull/2721

Original MinGW's w32api has CryptHashData's second parameter as BYTE *
instead of const BYTE *.

Closes https://github.com/curl/curl/pull/2721

They are not defined in the original MinGW's <wincrypt.h>.

Closes https://github.com/curl/curl/pull/2721

Otherwise, only part of it gets pulled in through <windows.h> on
original MinGW.

Fixes https://github.com/curl/curl/issues/2361
Closes https://github.com/curl/curl/pull/2721

When size_t is not a typedef for unsigned long (as usually the case on
Windows), GCC emits -Wformat warnings when using lu and lx format
specifiers with size_t. Silence them with explicit casts to
unsigned long.

Closes https://github.com/curl/curl/pull/2721

... not the read buffer size, as that can be set smaller and thus cause
a buffer overflow! CVE-2018-0500

Reported-by: Peter Wu
Bug: https://curl.haxx.se/docs/adv_2018-70a2.html

Closes #2718

...but GCC users lose out on TLS 1.3 support, since we can't weak-link
enumeration constants.

Fixes #2656
Closes #2703

Variable 'output_var' is not used and can be removed.
Function 'collect_true' renamed to 'count_true'.

Closes #2711

... because otherwise not everything get closed down correctly.

Fixes #2708
Closes #2712