Unity

What's new in this version:

Changes:
- Polarssl: removed
- Smtp: add CURLOPT_MAIL_RCPT_ALLLOWFAILS and --mail-rcpt-allowfails
- WolfSSH: new SSH backend

Bugfixes:
- Altsvc: improved header parser
- Altsvc: keep a copy of the file name to survive handle reset
- Altsvc: make saving the cache an atomic operation
- Altsvc: use h3-27
- Azure: disable brotli on the macos debug-builds
- Build: remove all HAVE_OPENSSL_ENGINE_H defines
- Checksrc.bat: Fix not being able to run script from the main curl dir
- Cleanup: fix several comment typos
- Cleanup: fix typos and wording in docs and comments
- Cmake: add support for CMAKE_LTO option
- Cmake: clean up and improve build procedures
- Cmake: enable SMB for Windows builds
- Cmake: improve libssh2 check on Windows
- Cmake: Show HTTPS-proxy in the features output
- Cmake: support specifying the target Windows version
- Cmake: use check_symbol_exists also for inet_pton
- Configure.ac: fix comments about --with-quiche
- Configure: disable metalink if mbedTLS is specified
- Configure: disable metalink support for incompatible SSL/TLS
- Conn: do not reuse connection if SOCKS proxy credentials differ
- Conncache: removed unused Curl_conncache_bundle_size()
- Connect: remove some spurious infof() calls
- Connection reuse: respect the max_concurrent_streams limits
- Contributors: also include people who contributed to curl-www
- Contrithanks: use the most recent tag by default
- Cookie: check __Secure- and __Host- case sensitively
- Cookies: make saving atomic with a rename
- Create-dirs.d: mention the mode
- Curl: avoid using strlen for testing if a string is empty
- Curl: error on --alt-svc use w/o support
- Curl: let -D merge headers in one file again
- Curl: make #0 not output the full URL
- Curl: make the -# spaceship bar not wrap the line
- Curl: remove 'config' field from OutStruct
- Curl:progressbarinit: ignore column width from terminals < 20
- Curl_escape.3: add a link to curl_free
- Curl_getenv.3: fix the memory handling description
- Curl_global_init: assume the EINTR bit by default
- Curl_global_init: move the IPv6 works status bool to multi handle
- CURLINFO_COOKIELIST.3: Fix example
- CURLOPT_ALTSVC_CTRL.3: fix the DEFAULT wording
- CURLOPT_PROXY_SSL_OPTIONS.3: Sync with CURLOPT_SSL_OPTIONS.3
- CURLOPT_REDIR_PROTOCOLS.3: update the DEFAULT section
- Data.d: remove "Multiple files can also be specified"
- Digest: do not quote algorithm in HTTP authorisation
- Docs/HTTP3: add --enable-alt-svc to curl's configure
- Docs/HTTP3: update the OpenSSL branch to use for ngtcp2
- Docs: fix typo on CURLINFO_RETRY_AFTER
- Easy: remove dead code
- Form.d: fix two minor typos
- Ftp: convert 'sock_accepted' to a plain boolean
- Ftp: remove superfluous checking for crlf in user or pwd
- Ftp: shrink temp buffers used for PORT
- Github action: add CIFuzz
- Github: Instructions to post "uname -a" on Unix systems in issues
- GnuTLS: always send client cert
- Gtls: fixed compilation when using GnuTLS < 3.5.0
- Hostip: move code to resolve IP address literals to `Curl_resolv`
- HTTP-COOKIES: describe the cookie file format
- HTTP-COOKIES: mention that a trailing newline is required
- Http2: make pausing/unpausing set/clear local stream window
- Http2: now requires nghttp2 >= 1.12.0
- Http: added 417 response treatment
- Http: increase EXPECT_100_THRESHOLD to 1Mb
- Http: mark POSTs with no body as "upload done" from the start
- Http: move "oauth_bearer" from connectdata to Curl_easy
- Include: remove non-curl prefixed defines
- KNOWN_BUGS: Multiple methods in a single WWW-Authenticate: header
- Libssh2: add support for forcing a hostkey type
- Libssh2: fix variable type
- Libssh: improve known hosts handling
- Llist: removed unused Curl_llist_move()
- Location.d: the method change is from POST to GET only
- Md4: fixed compilation issues when using GNU TLS gcrypt
- Md4: use init/update/final functions in Secure Transport
- Md5: added implementation for mbedTLS
- Mk-ca-bundle: add support for CKA_NSS_SERVER_DISTRUST_AFTER
- Multi: change curl_multi_wait/poll to error on negative timeout
- Multi: fix outdated comment
- Multi: if Curl_readwrite sets 'comeback' use expire, not loop
- Multi_done: if multiplexed, make conn->data point to another transfer
- Multi_wait: stop loop when sread() returns zero
- Ngtcp2: add error code for QUIC connection errors
- Ngtcp2: fixed to only use AF_INET6 when ENABLE_IPV6
- Ngtcp2: update to git master and its draft-25 support
- Ntlm: move the winbind data into the NTLM data structure
- Ntlm: pass the Curl_easy structure to the private winbind functions
- Ntlm: removed the dependency on the TLS libaries when using MD5
- Ntlm_wb: use Curl_socketpair() for greater portability
- Oauth2-bearer.d: works for HTTP too
- Openssl: make CURLINFO_CERTINFO not truncate x509v3 fields
- Openssl: remove redundant assignment
- Os400: fixed the build
- Pause: force-drain the transfer on unpause
- Quiche: update to draft-25
- README: mention that the docs is in docs/
- RELEASE-PROCEDURE: feature win is closed post-release a few days
- Runtests: make random seed fixed for a month
- Runtests: restore the command log
- Schannel: make CURLOPT_CAINFO work better on Windows 7
- Schannel_verify: Fix alt names manual verify for UNICODE builds
- Sha256: use crypto implementations when available
- Singleuse.pl: support new API functions, fix curl_dbg_ handling
- Smtp: support the SMTPUTF8 extension
- Smtp: support UTF-8 based host names in MAIL FROM
- SOCKS: make the connect phase non-blocking
- Strcase: turn Curl_raw_tolower into static
- Strerror: increase STRERROR_LEN 128 -> 256
- Test1323: added missing 'unit test' feature requirement
- Tests: add a unit test for MD4 digest generation
- Tests: add a unit test for SHA256 digest generation
- Tests: add a unit test for the HMAC hash generation
- Tests: deduce the tool name from the test case for unit tests
- Tests: fix Python 3 compatibility of smbserver.py
- Tool_dirhie: allow directory traversal during creationtool_homedir: change GetEnv() to use libcurl's curl_getenv()
- Tool_util: improve Windows version of tvnow()
- Travis: update non-OpenSSL Linux jobs to Bionic
- Url: include the failure reason when curl_win32_idn_to_ascii() fails
- Urlapi: guess scheme properly with credentials given
- Urldata: do string enums without #ifdefs for build scripts
- Vtls: refactor Curl_multissl_version to make the code clearer
- Win32: USE_WIN32_CRYPTO to enable Win32 based MD4, MD5 and SHA256