HTTP/3: skip empty request body buffers (ticket #2374). When client DATA frame header and its content come in different QUIC packets, it may happen that only the header is processed by the first ngx_http_v3_request_body_filter() call. In this case an empty request body buffer is added to r->request_body->bufs, which is later reused in a subsequent ngx_http_v3_request_body_filter() call without being removed from the body chain. As a result, rb->request_body->bufs ends up with two copies of the same buffer. The fix is to avoid adding empty request body buffers to r->request_body->bufs.

/*
 * 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