Function store_critical_bytes

src/version.c:675–694

#ifndef MINIMAL_FOR_RECOVER
void
store_critical_bytes(NHFILE *nhfp)
{
    int i, cnt;
    char indicate = 'u', csc_count = (char) SIZE(critical_sizes);
    /* int cmc = 0; */

    if (nhfp->mode & WRITING) {
        indicate = (nhfp->structlevel) ? 'h'
                                       : (nhfp->fnidx == exportascii)
                                         ? 'a'
                                         : '?';
        Sfo_char(nhfp, &indicate, "indicate-format", 1);
        Sfo_char(nhfp, &csc_count, "count-critical_sizes", 1);
        cnt = (int) csc_count;
        for (i = 0; i < cnt; ++i) {
            Sfo_uchar(nhfp, &critical_sizes[i].ucsize, "critical_sizes");
        }
    }
}

/* this used to be based on file date and somewhat OS-dependent,
 *  but now examines the initial part of the file's contents.