curl: re-enable UNICODE by default

The article
https://blog.orange.tw/posts/2025-01-worstfit-unveiling-hidden-transformers-in-windows-ansi/
may tip the balance towards UNICODE enabled being the less bad solution.
It mitigates Windows's own shortcomings in translating between Unicode
and 8-bit codepages (aptly coined "WorstFit"). It may also be a way to
receive more feedback on curl UNICODE mode issues, also possibly giving
a new momentum to address them.

Original reasons for disabling, written in
bb02905 still apply today.

Also add a `nounicode` config option to build without UNICODE.

Follow-up to bb02905

Author: vszakats

README.md

@@ -67,34 +67,34 @@ Uses [LibreSSL](https://www.libressl.org/) TLS backend.
 ```
 Windows:
 Protocols: dict file ftp ftps gopher gophers http https imap imaps ipfs ipns ldap ldaps mqtt pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp ws wss
-Features: alt-svc asyn-rr AsynchDNS brotli CAcert HSTS HTTP2 HTTP3 HTTPS-proxy HTTPSRR IDN IPv6 Kerberos Largefile libz NTLM PSL SPNEGO SSL SSPI SSLS-EXPORT threadsafe UnixSockets zstd
+Features: alt-svc asyn-rr AsynchDNS brotli CAcert HSTS HTTP2 HTTP3 HTTPS-proxy HTTPSRR IDN IPv6 Kerberos Largefile libz NTLM PSL SPNEGO SSL SSPI SSLS-EXPORT threadsafe Unicode UnixSockets zstd
 
 macOS:
 Protocols: dict file ftp ftps gopher gophers http https imap imaps ipfs ipns ldap ldaps mqtt pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp ws wss
-Features: alt-svc asyn-rr AsynchDNS brotli CAcert HSTS HTTP2 HTTP3 HTTPS-proxy HTTPSRR IDN IPv6          Largefile libz NTLM PSL        SSL      SSLS-EXPORT threadsafe UnixSockets zstd
+Features: alt-svc asyn-rr AsynchDNS brotli CAcert HSTS HTTP2 HTTP3 HTTPS-proxy HTTPSRR IDN IPv6          Largefile libz NTLM PSL        SSL      SSLS-EXPORT threadsafe         UnixSockets zstd
 
 Linux:
 Protocols: dict file ftp ftps gopher gophers http https imap imaps ipfs ipns            mqtt pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp ws wss
-Features: alt-svc asyn-rr AsynchDNS brotli CAcert HSTS HTTP2 HTTP3 HTTPS-proxy HTTPSRR     IPv6          Largefile libz NTLM PSL        SSL      SSLS-EXPORT threadsafe UnixSockets zstd
+Features: alt-svc asyn-rr AsynchDNS brotli CAcert HSTS HTTP2 HTTP3 HTTPS-proxy HTTPSRR     IPv6          Largefile libz NTLM PSL        SSL      SSLS-EXPORT threadsafe         UnixSockets zstd
 ```
 <details><summary>Alternate configurations:</summary><p>
 
 ```
 "nocares", HTTP/2:
 Protocols: dict file ftp ftps gopher gophers http https imap imaps ipfs ipns ldap ldaps mqtt pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp ws wss
-Features: alt-svc asyn-rr AsynchDNS brotli CAcert HSTS HTTP2       HTTPS-proxy         IDN IPv6 Kerberos Largefile libz NTLM PSL SPNEGO SSL SSPI SSLS-EXPORT threadsafe UnixSockets zstd
+Features: alt-svc         AsynchDNS brotli CAcert HSTS HTTP2       HTTPS-proxy         IDN IPv6 Kerberos Largefile libz NTLM PSL SPNEGO SSL SSPI SSLS-EXPORT threadsafe         UnixSockets zstd
 
 "mini", without brotli and zstd, with OS TLS backend (Schannel, SecureTransport) if available:
 Protocols: dict file ftp ftps gopher gophers http https imap imaps ipfs ipns ldap ldaps mqtt pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp ws wss
-Features: alt-svc         AsynchDNS        CAcert HSTS HTTP2       HTTPS-proxy         IDN IPv6 Kerberos Largefile libz NTLM PSL SPNEGO SSL SSPI             threadsafe UnixSockets
+Features: alt-svc         AsynchDNS        CAcert HSTS HTTP2       HTTPS-proxy         IDN IPv6 Kerberos Largefile libz NTLM PSL SPNEGO SSL SSPI             threadsafe         UnixSockets
 
 "micro", without libssh2:
 Protocols: dict file ftp ftps gopher gophers http https imap imaps ipfs ipns ldap ldaps mqtt pop3 pop3s rtsp          smb smbs smtp smtps telnet tftp ws wss
-Features: alt-svc         AsynchDNS        CAcert HSTS HTTP2       HTTPS-proxy         IDN IPv6 Kerberos Largefile libz NTLM PSL SPNEGO SSL SSPI             threadsafe UnixSockets
+Features: alt-svc         AsynchDNS        CAcert HSTS HTTP2       HTTPS-proxy         IDN IPv6 Kerberos Largefile libz NTLM PSL SPNEGO SSL SSPI             threadsafe         UnixSockets
 
 "nano", HTTP/1.1:
 Protocols: dict file ftp ftps gopher gophers http https imap imaps ipfs ipns ldap ldaps mqtt pop3 pop3s rtsp          smb smbs smtp smtps telnet tftp ws wss
-Features:                 AsynchDNS        CAcert HSTS             HTTPS-proxy         IDN IPv6 Kerberos Largefile libz NTLM PSL SPNEGO SSL SSPI             threadsafe UnixSockets
+Features:                 AsynchDNS        CAcert HSTS             HTTPS-proxy         IDN IPv6 Kerberos Largefile libz NTLM PSL SPNEGO SSL SSPI             threadsafe         UnixSockets
 
 "pico", HTTP/1.1-only:
 Protocols:                                   http https

_build.sh

@@ -70,7 +70,7 @@ set -o xtrace -o errexit -o nounset; [ -n "${BASH:-}${ZSH_NAME:-}" ] && set -o p
 #        curldocs   include curl Markdown manual pages in the package
 #        msvcrt     build against msvcrt instead of UCRT (for win target)
 #        gcc        build with GCC (including Apple clang aliased to gcc) (defaults to llvm, and "gcc" (= Apple clang) for mac target)
-#        unicode    build curl in UNICODE mode (for win target) [EXPERIMENTAL]
+#        nounicode  build curl without [EXPERIMENTAL] UNICODE mode (for win target)
 #        osnoidn    build curl without OS-supplied IDN support
 #        werror     turn compiler warnings into errors
 #        debug      debug build

curl.sh

@@ -43,7 +43,7 @@ _VER="$1"
   # [ "${_CC}" = 'gcc' ] && LDFLAGS+=' -Wl,--trace'
   fi
 
-  if [ "${_OS}" = 'win' ] && [[ "${_CONFIG}" = *'unicode'* ]]; then
+  if [ "${_OS}" = 'win' ] && [[ "${_CONFIG}" != *'nounicode'* ]]; then
     options+=' -DENABLE_UNICODE=ON'
   fi