
<   for (row = 0; row < num_rows; row++) {
<     /* Initialize output values to 0 so can process components separately */
<     jzero_far((void *) output_buf[row], (size_t) (width * sizeof(JSAMPLE)));
---
>   for (row = 0; row < num_rows; row++) {
>     /* Initialize output values to 0 so can process components separately */
>     if (output_buf != NULL && output_buf[row] != NULL) {
>       jzero_far((void *) output_buf[row], (size_t) (width * sizeof(JSAMPLE)));
>     }
