HTTP/3: fixed segfault when using SSL certificates with variables. A QUIC connection doesn't have c->log->data and friends initialized to sensible values. Yet, a request can be created in the certificate callback with such an assumption, which leads to a segmentation fault due to null pointer dereference in ngx_http_free_request(). The fix is to adjust initializing the QUIC part of a connection such that it has all of that in place. Further, this appends logging error context for unsuccessful QUIC handshakes: - cannot load certificate .. while handling frames - SSL_do_handshake() failed .. while sending frames

/*
 * Copyright (C) Maxim Dounin
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>


#if (NGX_HAVE_DLOPEN)

char *
ngx_dlerror(void)
{
    char  *err;

    err = (char *) dlerror();

    if (err == NULL) {
        return "";
    }

    return err;
}

#endif