SSL: clear error queue after OPENSSL_init_ssl(). The function may leave error in the error queue while returning success, e.g., when taking a DSO reference to itself as of OpenSSL 1.1.0d: https://git.openssl.org/?p=openssl.git;a=commit;h=4af9f7f Notably, this fixes alert seen with statically linked OpenSSL on some platforms. While here, check OPENSSL_init_ssl() return value.

# Copyright (C) Nginx, Inc.


if [ $USE_THREADS = YES ]; then

    if [ "$NGX_PLATFORM" = win32 ]; then
        cat << END

$0: --with-threads is not supported on Windows

END
        exit 1
    fi

    have=NGX_THREADS . auto/have
    CORE_DEPS="$CORE_DEPS $THREAD_POOL_DEPS"
    CORE_SRCS="$CORE_SRCS $THREAD_POOL_SRCS"
    CORE_LIBS="$CORE_LIBS -lpthread"
fi