rid = db_int(0,
     "SELECT x.rid FROM tag t, tagxref x"
     " WHERE x.tagid=t.tagid AND t.tagname='wiki-%q'"
     " ORDER BY x.mtime DESC LIMIT 1",
     zPageName
  );
  if( rid==0 && !isNew ){
#ifdef FOSSIL_ENABLE_JSON
    g.json.resultCode = FSL_JSON_E_RESOURCE_NOT_FOUND;
#endif
    fossil_fatal("no such wiki page: %s", zPageName);
  }
  if( rid!=0 && isNew ){
#ifdef FOSSIL_ENABLE_JSON
    g.json.resultCode = FSL_JSON_E_RESOURCE_ALREADY_EXISTS;
#endif
    fossil_fatal("wiki page %s already exists", zPageName);
  }

  blob_zero(&wiki);
  zDate = date_in_standard_format("now");
  blob_appendf(&wiki, "D %s\n", zDate);
  free(zDate);