now writers the headers with the data->fwrite() function as well

lib/download.c

@@ -322,7 +322,7 @@ Transfer (struct UrlData *data,
                   /* obviously, the header is requested to be written to
                      this file: */
                   if((p - data->headerbuff) !=
-                     fwrite (data->headerbuff, 1, p - data->headerbuff,
+                     data->fwrite (data->headerbuff, 1, p - data->headerbuff,
                                    data->writeheader)) {
                     failf (data, "Failed writing output");
                     return URG_WRITE_ERROR;
@@ -392,7 +392,8 @@ Transfer (struct UrlData *data,
               }
               if(data->writeheader) {
                 /* the header is requested to be written to this file */
-                if(hbuflen != fwrite (p, 1, hbuflen, data->writeheader)) {
+                if(hbuflen != data->fwrite (p, 1, hbuflen,
+                                            data->writeheader)) {
                   failf (data, "Failed writing output");
                   return URG_WRITE_ERROR;
                 }