- /* We just read something, so we are supposed to write something, too */
- pending_read_bytes += n_read;
- do_write += pending_read_bytes / u->write_block_size;
- pending_read_bytes = pending_read_bytes % u->write_block_size;
+ if (n_read > 0) {
+ /* We just read something, so we are supposed to write something, too */
+ pending_read_bytes += n_read;
+ do_write += pending_read_bytes / u->write_block_size;
+ pending_read_bytes = pending_read_bytes % u->write_block_size;
+ }