Range filter: clearing of pre-existing Content-Range headers. Some servers might emit Content-Range header on 200 responses, and this does not seem to contradict RFC 9110: as per RFC 9110, the Content-Range header has no meaning for status codes other than 206 and 416. Previously this resulted in duplicate Content-Range headers in nginx responses handled by the range filter. Fix is to clear pre-existing headers.

/*
 * 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