The required low-level logic was already available as part of
`libssh2` (via `LIBSSH2_FLAG_COMPRESS` `libssh2_session_flag()`[1]
option.)
This patch adds the new `libcurl` option `CURLOPT_SSH_COMPRESSION`
(boolean) and the new `curl` command-line option `--compressed-ssh`
to request this `libssh2` feature. To have compression enabled, it
is required that the SSH server supports a (zlib) compatible
compression method and that `libssh2` was built with `zlib` support
enabled.
[1] https://www.libssh2.org/libssh2_session_flag.html
Ref: https://github.com/curl/curl/issues/1732
Closes https://github.com/curl/curl/pull/1735
... to enable sending "OPTIONS *" which wasn't possible previously.
This option currently only works for HTTP.
Added test cases 1298 + 1299 to verify
Fixes#1280Closes#1462
... and USE_ENVIRONMENT and --environment. It was once added for RISC OS
support and its platform specific behavior has been annoying ever
since. Added in commit c3c8bbd3b2, mostly unchanged since
then. Most probably not actually used for years.
Closes#1463
For easier sharing with CMake. The contents were reformatted to use
two-space indent and expanded tabs (matching lib/Makefile.common).
Ref: https://github.com/curl/curl/pull/1288
