1:  e7e2d43b18 ! 1:  b07af1c564 libpq: add sslrootcert=system to use default CAs
    @@ configure: fi
     
      ## configure.ac ##
     @@ configure.ac: if test "$with_ssl" = openssl ; then
    -   # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
    -   # function was removed.
        AC_CHECK_FUNCS([CRYPTO_lock])
    +   # Function introduced in OpenSSL 1.1.1.
    +   AC_CHECK_FUNCS([X509_get_signature_info])
     +  # Let tests differentiate between vanilla OpenSSL and LibreSSL.
     +  AC_CHECK_DECLS([LIBRESSL_VERSION_NUMBER], [], [], [#include <openssl/opensslv.h>])
        AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
2:  e4d9731e1e = 2:  5de1c458b1 libpq: force sslmode=verify-full for system CAs