Use negated option for controlling TLS support.
A positive option looks better, but comes with the following compatibility
issue: people using a custom config.h that is not based on the default
config.h and need TLS support would need to manually change their config in
order to still get TLS.
Work around that by making the public option negative. Internally the positive
option is used, though.
In the future (when preparing the next major version), we might want to switch
back to a positive option as this would be more consistent with other options
we have.
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index b3677b5..34f1a3b 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -566,7 +566,7 @@
#endif
#if defined(MBEDTLS_SSL_TLS_C) && \
- ( !defined(MBEDTLS_SSL_PROTO_TLS) && !defined(MBEDTLS_SSL_PROTO_DTLS) )
+ ( defined(MBEDTLS_SSL_PROTO_NO_TLS) && !defined(MBEDTLS_SSL_PROTO_DTLS) )
#error "MBEDTLS_SSL_TLS_C defined, but neither TLS or DTLS is active"
#endif