[openssl-dev] Next protocol negotiations and different defines in opensslconf.h

[Jeffrey Walton]

I *think* this question on Stack Overflow is due to changing the
define associated with protocol negotiations: "Building curl from
sources - undefined reference to SSL_CTX_set_alpn_protos"
(http://stackoverflow.com/q/36404426). That is, OpenSSL 1.0.2 used
'no-npn' and OPENSSL_NO_NPN, while 1.1.0 uses 'no-nextprotoneg' and
OPENSSL_NO_NEXTPROTONEG.

Maybe it would be a good idea to ensure 1.1.0 defines both
OPENSSL_NO_NEXTPROTONEG (1.1.0) and OPENSSL_NO_NPN (1.0.2 and
earlier). Perhaps something like the following:

#ifdef OPENSSL_NO_NEXTPROTONEG
# define OPENSSL_NO_NPN
#endif

I think its easier to fix OpenSSL in one place rather than fix
thousands of user programs hundreds of libraries.

Jeff